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  Current Issue
 
2023 Vol.43 Issue.10,Published 2023-10-20
Air Pollution Control
Water Pollution Control
Solid Waste
Soil Pollution Control
Environmental Microbiology
Environmental Ecology
Environmental Impact Assessment and Management
Carbon Emission Control
Emerging Contaminants and Environmental Toxicology
Air Pollution Control
5041 Effects of the Three-year Action Plan on pollution characteristics and sources of environmentally persistent free radicals in the atmosphere
DING Jia-le, CHEN Qing-cai, ZHANG Zi-meng, HAN Yue-mei
The concentration characteristics, species type, and potential sources of environmentally persistent free radicals (EPFRs) in atmospheric PM2.5 of Xi'an were investigated during, before, and after the implementation of the Three-year Action Plan for Winning the Blue Sky Battle, using Electron paramagnetic resonance spectroscopy (EPR). Results showed that the mean concentration of EPFRs after the implementation of the plan (5.03×1014spins/m3) decreased 29.9% compared with that before the implementation (7.18×1014spins/m3), which suggests that EPFRs were effectively controlled due to the implementation of the Three-year Action Plan. The mean concentration of EPFRs in winter (8.61×1014spins/m3) was 2.8times that in summer (3.10×1014spins/m3), and the main type was the free radicals affected by oxygen-containing functional groups near the carbon atoms. Correlations and parallel factor analysis revealed that coal combustion (35.3%), traffic emission (30.0%), and dust (27.8%) were the main sources of EPFEs in atmospheric PM2.5 of Xi'an. Traffic emission was the most dominant source of EPFRs in winter season (45.8%), whereas the EPFRs was strongly correlated with O3 in summer season and the contribution of secondary sources was 2.2~5.7times that of other seasons. The contribution of coal combustion to EPFRs decreased significantly (13.7%) after the implementation of the plan, indicating that policies such as clean heating, total coal consumption control, and comprehensive improvement of coal-fired boilers were very effective. The contributions of traffic emission, dust, and secondary sources slightly increased (3.70%, 3.00%, and 7.00%, respectively), suggesting that the comprehensive controlling of dust, motor vehicle emission for green travel, as well as O3 and VOCs should be the primary focus for future pollution control. The contributions of coal combustion (42.9%) and dust (33.4%) to EPFRs were relatively high on heavy pollution days, whereas the contributions of traffic emission (31.7%) and secondary sources (8.95%) were relatively high on clean days, suggesting that in addition to reduce heavy pollution days, the health impact of EPFRs on clean days also warrant further attention.
2023 Vol. 43 (10): 5041-5051 [Abstract] ( 202 ) [HTML 1KB] [ PDF 2004KB] ( 1510 )
5052 BVOCs emission inventory in the Beijing-Tianjin-Hebei region based on multiple models and data sources
LI Ao-zhe, DUAN Wen-jiao, QI Hao-yun, CAI Bin
In order to systematically study the spatial and temporal distributions of biogenic volatile organic compounds (BVOCs) emissions in the Beijing-Tianjin-Hebei (BTH) region, this paper calculated county-level emissions of BVOCs and major components in the BTH region in 2018 based on three methods, including the stock production, land use remote sensing interpretation data, and MEGAN model. The results based on the three methods showed that the total BVOCs emissions in the BTH region were 741400t, 844800t, and 777300t, respectively. The emissions in Beijing, Tianjin, and Hebei were 118000t, 32000t and 637000t, the emissions of isoprene, monoterpenes, and others were 291900t, 225800t, and 274100t, and the emissions of forest land, cropland and grassland accounted for 68.42%, 23.07% and 3.89%, respectively. From the perspective of temporal distributions, BVOCs emissions were characterized by a single peak. Summer showed the highest emissions of 526400t, accounting for 66.64% of the whole year, while winter showed the lowest emissions of 15900t, accounting for 2.01% of the whole year. From the perspective of spatial distributions, BVOCs emissions based on different methods presented similar spatial distribution characteristics of high emissions in north and low emissions in south. The emissions along Taihang Mountains and Yanshan Mountains were dominated by forest land and grassland, while those in the southeastern Hebei Plain was dominated by farmland. From the perspective of methods, the emissions obtained with the light-temperature model based on remote sensing interpretation were relatively high, and the proportion of other BVOCs obtained with the dynamic model was relatively high. This study provides data support for the comprehensive understanding of BVOCs emission characteristics and the planning of continuous air quality improvement strategies in the BTH region.
2023 Vol. 43 (10): 5052-5061 [Abstract] ( 319 ) [HTML 1KB] [ PDF 1854KB] ( 1854 )
5062 Spatial and temporal variation and isotopic composition of CH4 and CO2 in Xiangshan Bay
LI Xue, DUAN Xiao-yong, YIN Ping, GAO Fei, CAO Ke, TIAN Yuan, LI Mei-na, LIU Xiao-feng, Lü Sheng-hua
Understanding the greenhouse gas emissions in the global Gulf region is of great significance for coping with global warming. Therefore, the Xiangshan Bay, a typical gulf, was selected to reveal the impact of coastal zone on global climate change, through analyzing the concentration changes of CH4 and CO2 and their relationship with meteorological elements in the bay. The data showed that the CH4 concentrations in Xiangshan Bay area ranged from 1.72×10-6to 2.17×10-6, with an average concentration of 1.82×10-6. The δ13CCH4 values range from -60.69‰ to -41.10‰, with an average value of -50.261‰. The concentrations of CO2 range from 410.3×10-6 to 640.883×10-6, with an average concentration of 433.294×10-6. The δ13CCO2 values range from -16.79‰ to -2.33‰, with an average value of -6.83‰. On the whole, the content of CH4 in the bay was greater than that outside the bay, and gradually decreased from land to sea, indicating that the near shallow sea area was the source of atmospheric methane. The overall trend of CO2 content variation in the bay was low, which indicates that it is the sink of CO2. Combined with land use types, the changes of CH4 and CO2 concentrations were greatly affected by anthropic factors, and greenhouse gases were significantly higher in building land, forest land and cultivated land. In contrast, the concentrations of greenhouse gases were lower in the plain and aquaculture areas. At the same time, the diurnal variation of CH4 and CO2 concentrations was basically the same, showing a tendency of greater during daytime than that of at night, and the isotopic composition was negatively correlated with their concentrations. In terms of time distribution, the concentration of CH4 and CO2 is significantly affected by temperature, humidity, wind speed, tidal action, the strength of large air source and sink, and the pressure difference at the water-air interface.
2023 Vol. 43 (10): 5062-5069 [Abstract] ( 246 ) [HTML 1KB] [ PDF 3240KB] ( 1506 )
5070 Study of atmospheric boundary layer height over Tianjin sea-shore-land area based on Lidar
LIU Jing-le, SHI Jing, LI Pei-yan, JIANG Ming, CAI Zi-ying, HAN Su-qin, CUI Ye, YAO Qing
The atmospheric boundary layer heights over urban area of Tianjin, the Bohai coast and the Bohai area were retrieved using the aerosol Lidar observation data from August 2018 to July 2019. And the result of aerosol Lidar inversion were verified by sounding observation of unmanned aerial vehicle. Combined with the different meteorological characteristics of Tianjin atmospheric boundary layer observation station, Tanggu sation and Bohai A-platform station, the distribution characteristics of the atmospheric boundary layer heights and the reasons for the differences were analyzed. The results showed that the atmospheric boundary layer heights obtained by Lidar and unmanned aerial vehicle had high uniformity, and the correlation coefficients between them were 0.508, 0.565 and 0.687, respectively, under stable, neutral and unstable stratification conditions. The diurnal variation of the atmospheric boundary layer heights in Tianjin urban area and Tanggu area showed unimodal distribution, which was close to the diurnal variation of turbulent kinetic energy and sensible heat flux in each season. The atmospheric boundary layer heights of A-platform had obvious characteristics of ocean atmosphere, which were higher than those of the urban area and Tanggu area in winter, but the opposite performance in summer. The formation of the intra-thermal boundary layer caused by the sea-land circulation in summer was one of the reasons for the difference in the heights of the atmospheric boundary layer between the urban area and Tanggu. When the intra-thermal boundary layer appeared in Tanggu in summer of 2019, the height of the afternoon boundary layer decreased by 30 to 160m approximately, while the difference between the boundary layer heights of Tanggu and the urban area increased by 150 to 300m approximately.
2023 Vol. 43 (10): 5070-5077 [Abstract] ( 165 ) [HTML 1KB] [ PDF 902KB] ( 1768 )
5078 Impact characteristics of typical atmospheric circulation on the combined pollution of PM2.5 and O3 in Tianjin
XU Ya-zi, YANG Yi-cheng, LIU Yong-ji, MENG Peng, SUN Nai-xiu, WU Lin, MAO Hong-jun
To investigate the impact of sea-land breezes on PM2.5 and O3 pollution in coastal cities, the observation pollution and meteorological data of China National Environmental Monitoring Centre and ERA5 hourly data from 2016 to 2020 were analyzed to elucidate the influence of sea-land breezes circulation characteristics on PM2.5 and O3 levels in the coastal areas of Tianjin. The results showed there were 411sea-l and breezes days between 2016 and 2020, the sea-land breezes circulation frequently occurred from April to September, with the lowest frequency in December. The variation in seasonal characteristics of sea-land breezes circulation led to different impacts on PM2.5 and O3 levels. Land breeze circulation leads to PM2.5 accumulation in coastal areas, and sea breeze circulation has a certain diffusion effect on PM2.5 in winter. Sea-land breezes circulation change the distribution of O3 in coastal areas, resulting in reduced valley values and increased daytime peaks of O3 The peak concentration of O3 in urban, suburban, and coastal locations were 4.1,8.9,16.0μg/m3 higher than the average peak value. The influence on peak value decreases as the distance from the coastline increases. A total of 94days of PM2.5 and O3 combined pollution from 2016 to 2020, and sea-land breezes occurred during 17 of these days. On PM2.5 and O3 combined pollution days with sea-land breezes, land breeze circulation transmitted PM2.5 from the central urban area to the coast, while the sea breeze exhibited a scavenging effect on PM2.5. The photochemical net decomposition rate of O3 during land breeze circulation was higher than those days without sea-land breezes, while the photochemical net generation time of O3 was longer during the sea breeze circulation. The effects of sea-land breezes circulation on O3 and PM2.5 reduced the frequency of PM2.5 and O3 composite pollution. Sea-land breezes' transport and redistribution of PM2.5 and O3 to coastal areas have a complex impact on regional pollution.
2023 Vol. 43 (10): 5078-5087 [Abstract] ( 173 ) [HTML 1KB] [ PDF 1729KB] ( 1331 )
5088 Improvement on numerical simulation by variational assimilation of surface PM2.5 and aerosol lidar during a heavy pollution episode in winter in Tianjin
YANG Xu, FAN Wen-yan, CAI Zi-ying, ZHU Yu-qiang, TANG Ying-xiao, DONG Qi-ru
For the transport-type heavy pollution episodes, the vertical simulation deviation of atmospheric chemical model was large, the ground observation assimilation could not significantly improve the vertical initial field of pollution, and the upper air transport was underestimated. A heavy pollution episode was taken as an example in Tianjin, which occurred from January 5 to 6, 2023, the aerosol variational assimilation technology was developed for the joint application of surface PM2.5 and aerosol lidar vertical observations, to improve the vertical pollution simulation of atmospheric chemical model and serve forecast, early warning and mechanism analysis of heavy pollution episodes. The results showed that during the heavy pollution episode, growth rate and peak concentration of ground PM2.5 was significantly underestimated, simulated pollution layer height was about 200~300m lower than observed value and characteristics such as higher PM2.5 concentration in upper air than that on the ground in transportation phase of daytime and high pollution values above the stable boundary layer at night were not effectively reflected; Assimilation of surface PM2.5 observations effectively optimized PM2.5 spatial distribution, average simulation error decreased by 35.3μg/m3 and 77.3μg/m3 respectively in Shijiazhuang and Hengshui, the upstream cities and decreased by 39.7μg/m3 in Tianjin. However, its improvement on vertical distribution simulation was limited, especially for the complex change of PM2.5 vertical distribution in transport-type pollution episode, which was not accurately reflected. By adding assimilation of vertical PM2.5 observations obtained from aerosol lidar, vertical PM2.5 simulation was further improved, the maximum reduction of PM2.5 mass concentration RMSE was 19.8μg/m3 at about 500m. There was obvious positive effect at the assimilated time and within 2~3h, as for subsequent time, simulated pollution layer height was basically same with observation in S2 phase, the difference between them reduced to 50~100m, compared with 200~300m in CTRL experiment without assimilation and 100~200m in DA_SFC experiment with surface PM2.5 assimilation. High value of pollution above stable boundary layer was effectively simulated and the simulation error of PM2.5 mass concentration in the heavy polluted layer was significantly reduced; Assimilation effect in the daytime on January 5 was not good as that of S2 phase, accurate simulation of vertical PM2.5 could be achieved in a short time, but the deviation of vertical simulation had been significantly enlarged again with simulation time increasing. In spite of this, positive effect still existed compared with DA_SFC and the simulation error of pollution layer height was reduced by at least 50m.
2023 Vol. 43 (10): 5088-5097 [Abstract] ( 150 ) [HTML 1KB] [ PDF 2047KB] ( 1015 )
5098 Analysis of characteristics and meteorological conditions of PM2.5-O3 compound pollution in Jiangsu province
YAN Wen-lian, LIU Duan-yang, WANG Lei, LI Cong
Based on the air pollution and meteorological observation data of 13cities in Jiangsu Province from 2013 to 2020, the distribution characteristics of PM2.5-O3 compound air pollutants and their relationship with meteorological conditions were analyzed. The results showed that the occurrence frequency of compound pollutants in Jiangsu were mainly composed of light pollution combinations, with more in the south, especially in the southeast. The compound air pollutants mainly appeared from April to October, with the highest concentration from afternoon to evening, and the average concentration of ozone during this period was higher than that of single ozone pollution; The average compound pollution days account for 15.7% of high ozone days, which was as high as 65.8% in 2014 and has significantly decreased since 2015. There was a positive correlation between PM2.5 and ozone concentrations in the warm season ozone pollution period, and a weak or negative correlation in the PM2.5 pollution period. The air temperature, relative humidity, wind speed and inversion conditions during the compound air pollution period are between single ozone pollution and PM2.5 pollution, mostly of them are below 4m/s and in the ENE-S wind direction range. Compared with the single ozone pollution, air temperature and wind speed are slightly lower, while relative humidity and inversion intensity are slightly higher during the compound air pollution. The main surface situations of compound pollution are the uniform pressure field and the front of low pressure (bottom), followed by the rear of high pressure into the sea and the bottom of high pressure. Through the backward trajectory cluster analysis, it is found that the compound pollution in Huaibei area mainly comes from the southeast coast to the local path, the central and southern cities mainly come from the surrounding areas and the southeast coastal area, and the southeastern cities mainly come from the short-distance transport and the Jiangsu-Anhui-Zhejiang border area.
2023 Vol. 43 (10): 5098-5106 [Abstract] ( 201 ) [HTML 1KB] [ PDF 4029KB] ( 1765 )
5107 Experimental study on synergistic enhancement of dust removal by surface active agent and charged water mist
DING Hou-cheng, ZHANG Cheng-hao, DENG Quan-long, XU Wan-ping, LI Yin, XIA Xu
To study the dust removal efficiency and application range expansion of wet electrostatic precipitators, an experimental device was designed for surface-active agent synergistic charged water mist dust removal targeting iron ore dust, using surface-active agent-enhanced wetting, water film capture, and charged capture theories. The effects of wind speed, voltage, spray pressure, and grid number on dust removal performance were investigated. In the experiment, a series of composite surface-active agent solutions were tested, including 0.3% LABSA/0.5% X-100, 0.3% LABSA/0.5% AES, and 0.5% X-100/0.5% AES, for charged water mist dust removal. The results showed that composite electrostatic precipitators could improve dust removal efficiency while increasing treatment air volume. Wind speed was positively correlated with dust removal efficiency below 0.8m/s. The composite solution achieved the highest dust removal efficiency at a water pressure of 6MPa, with 0.3% LABSA/0.5% AES performing the best, increasing dust removal efficiency by 15.36% compared to water, with an average improvement of 11.73% for different water pressures. The dust removal efficiency of the composite electrostatic precipitator was positively correlated with voltage before 40kV, but decreased after due to corona discharge. The grid with a pore size of 40mesh had the highest dust removal efficiency. Among the composite solutions, 0.3% LABSA/0.5% AES achieved a dust removal efficiency of 96.74%, and reducing the pore size further decreased the dust removal efficiency.The stronger the wetting ability of the surface active agent on dust, the greater the improvement in dust removal efficiency when it is involved in the dust removal process.
2023 Vol. 43 (10): 5107-5113 [Abstract] ( 138 ) [HTML 1KB] [ PDF 732KB] ( 1796 )
5114 Characteristics and sources of dicarbonyl compounds during summer photochemical pollution episodes in Wuhan
HUANG Hai-bin, CHENG Hai-rong, HU Ke, HUANG Yu, DENG Meng-jie, TAO Hui-ting
Field measurements of atmospheric carbonyl compounds and volatile organic compounds (VOCs) were conducted during the summer photochemical pollution process in Wuhan in 2021. This study focused on the pollution characteristics of glyoxal and methylglyoxal and analyzed their sources using positive matrix factor model (PMF). The average concentrations of glyoxal and methylglyoxal in Wuhan were (0.42±0.34)×10-9and (0.69±0.19)×10-9, respectively, and both showed a "unimodal type" diurnal pattern, peaking at 10a.m. Six sources were identified using PMF. The contributions of these sources to glyoxal were in the order of secondary formation (A) (70.86%) > solvent usage (8.05%) > vehicle emission (8.04%) > combustion (6.43%) > industrial emission (3.38%) > secondary formation (B). The contributions of different sources to methylglyoxal were in the order of secondary formation (A) (39.10%) > secondary formation (B) (31.54%) > vehicle emission (13.26%) > solvent usage (8.21%) > combustion (5.80%) > industrial emission (2.09%). Due to the strong photochemical reactions in summer, secondary formation was the most important source of glyoxal and methylglyoxal. Compared with those during the non-episodes, the contribution of secondary formation (A) to glyoxal and methylglyoxal increased significantly during the O3-polluted photochemical episodes. This study helps to improve the understanding of glyoxal and methylglyoxal in Wuhan, and provides valuable datasets for the government of Wuhan to formulate air pollution prevention and control strategies.
2023 Vol. 43 (10): 5114-5122 [Abstract] ( 187 ) [HTML 1KB] [ PDF 1320KB] ( 1524 )
5123 Effect of additives and SO2 on selective catalytic oxidation of NH3 over CuO/TiO2 catalysts
CHEN Hao-hui, WANG Ya-zhou, YU Jie, QIU Lei, YIN Yi-meng, WANG Chi-zhong, CHANG Hua-zhen
A series of CuO-MOx/TiO2 (M=W, Zr, La) catalysts were prepared by impregnation method for the selective catalytic oxidation of NH3, and the effects of SO2 poisoning on the oxidation of NH3 over Cu/Ti-based catalysts were investigated. The results show that adding of transition metal oxides decreased the NH3 conversion efficiency of Cu/Ti catalyst slightly, but significantly improved the N2 selectivity. WO3 was the best promoter among those additives, with an increase of N2 selectivity by 36% at 300℃ in comparison to Cu/Ti catalyst. The H2-TPR and NH3-TPD results indicate that adding of WO3 significantly increased the number of acid sites on the surface of Cu/Ti catalyst, and promoted the adsorption of NH3. But it affected the redox performance of the catalyst and inhibited the oxidation of NH3 to NOx. After SO2 poisoning, the N2 selectivity of CuO-MOx/TiO2 catalyst was further improved. The characterization results shows that the increase of acid sites and the reduction of redox performance are the key factors to improve the N2 selectivity.
2023 Vol. 43 (10): 5123-5130 [Abstract] ( 165 ) [HTML 1KB] [ PDF 529KB] ( 1668 )
Water Pollution Control
5131 Study on catalytic performance and reaction mechanism of catalytic denitrification
YUN Yu-pan, MIAO Zhi-jia, WANG Xiao-lei, WANG Wei-yan, YU Hai-tao
In order to resolve nitrate pollution in water body, the novel catalytic denitrification by synergistic effect of zero-valent iron (Fe0) and Pd-Cu catalyst was proposed. The optimization of operational conditions, reaction mechanism, and kinetic study were further investigated. Results found that using response surface methodology for experimental design and data analyses, 74.6% of N2 conversion was obtained under the following optimal conditions:5.0pH, 135min reaction time, 3.1mass ration (Pd:Cu), and 3.1g/L Fe0. In the catalytic process, Fe0primarily serves as the electron donor. Pd and Cu coated on the carrier play critical roles in catalytic denitrification. Physical-chemical characteristics of carrier (such as porous structure, specific surface area, adsorption ability etc.) dramatically influence the catalytic performance. It's also found that N2conversion could be greatly improved by controlling solution pH, acid wash of carrier, and replacement of catalyst's active ingredient. Catalytic reduction of nitrate was better demonstrated by first-order equation of Langmuir-Hinshelwood modeling. Catalytic denitrification has been regarded as the typical multiphase and multistage reaction process. Acid and alkaline wash by certain concentration of HCl or NaOH solution may partially regenerate the catalyst and improve its catalytic performance.
2023 Vol. 43 (10): 5131-5138 [Abstract] ( 265 ) [HTML 1KB] [ PDF 1244KB] ( 1664 )
5139 Regulating endogenous orthophosphate to initiate a synchronous short-pass nitrification and denitrification phosphorus removal granular sludge process
LI Dong, XIE Yi-bo, GAO Fei-yan, ZHU Yan-jun, ZHANG Jie
Orthophosphate is an intermediate product of the biological denitrification process of phosphorus aggregation, which affects the activity of denitrifying phosphorus aggregating bacteria (DPAOs) in competition with other heterotrophic bacteria for carbon sources. In this study, four groups of sequencing batch reactors (SBRs) were operated with various endogenous orthophosphate regulating techniques utilizing synthetic water as influent after being inoculated with flocculent activated sludge.The study aimed to investigate the effects of different endogenous orthophosphate regulation methods on the enrichment of denitrifying phosphorus accumulating bacteria (DPAOs) and granulation. The results showed that the granular sludge operated with endogenous orthophosphate effluent reflux exhibited better nitrogen and phosphorus removal efficiency, higher DPAO activity, and good particle sedimentation performance.In particular, compared to granular sludge systems operated in microaerobic mode, those operated in anaerobic/microaerobic (AO) mode demonstrated superior pollutant treatment performance, with COD, TN, and TP removal efficiencies reaching 92.57%, 94.7%, and 97.62%, respectively. This was attributed to multiple factors, such as endogenous orthophosphate stimulation, the synergistic effect of DPAOs and denitrifying glycans bacteria (DGAOs).Periodic regulation of endogenous orthophosphate in the system resulted in a significant increase in the internal carbon source conversion rate of sludge, enhanced activities of DPAOs and DGAOs, and inhibition of heterotrophic denitrifying bacteria (DOHOs). Under a longer cycle operation mode, ammonia oxidizing bacteria (AOB) and DPAOs interacted, while also inhibiting the growth of other heterotrophic microorganisms. The findings of this study provide theoretical support for the practical engineering application of simultaneous short-range nitritation-denitritation phosphorus removal (SPNDPR) process.
2023 Vol. 43 (10): 5139-5147 [Abstract] ( 231 ) [HTML 1KB] [ PDF 905KB] ( 1393 )
5148 Simultaneous removal of phosphate and fluoride from acid wastewater by Ce-La bimetal oxides: Performance and mechanism
LI Han, ZHAO Yu, CHEN Jia-chao, XU Hai-min, ZHU Ya-xian, CHEN Zhi-hui, SHEN Meng-meng, YANG Wen-lan
A novel Ce-La bimetal oxides nano-adsorbent (CLBOs) capable of simultaneous phosphate and fluoride removal from water was successfully synthesized by coprecipitation method. The CLBOs existed primarily as nanoparticles or nanoclusters, with a particle size range of 20~50nm and a specific surface area of 117.9m2/g. Notably, the CLBOs displayed excellent chemical stability across a wide pH range (4~12), with acidic conditions proving beneficial for the adsorption of phosphate and fluoride. Under experimental condition of pH 4.0and initial concentrations of 30mg/L for phosphate and 10mg/L for fluoride, the CLBOs exhibited a remarkable maximum adsorption capacity of 59.14mg/g for phosphate and 19.25mg/g for fluoride. This outstanding adsorption performance was attributed to the combined effects of electrostatic attraction, ligand exchange, and inner-sphere complexation. Furthermore, the presence of competing anions had minimal impact on the removal efficiency of CLBOs. The adsorption process of phosphate and fluoride onto CLBOs followed a pseudo-second-order kinetic model, with fluoride being adsorbed significantly faster than phosphate. Equilibrium was achieved in approximately 100 minutes for fluoride and 240 minutes for phosphate. Importantly, the exhausted CLBOs could be efficiently regenerated through a simple alkaline treatment, enabling their cyclic utilization while maintaining consistent adsorption performance. In conclusion, the results demonstrate that CLBOs is a highly efficient adsorbent with significant potential for practical applications in the simultaneous removal of phosphate and fluoride from wastewater.
2023 Vol. 43 (10): 5148-5156 [Abstract] ( 155 ) [HTML 0KB] [ PDF 927KB] ( 1691 )
5157 Pr-doped Ni~(Ce-Zr)O2/Al2O3 for TWC reaction: Defect property-activity relationship
ZHANG Tong, LI Qiao-yan, WANG Xiao-yan, LIANG Mei-sheng, LAI Zhuo-jun
To investigate the influence of defect structures in CeZrOx catalysts, which induced by rare earth metal doping, on the control of automotive exhaust pollution, series of Ni~(Ce6Zr4-xPrx)O2/Al2O3 catalysts with varied Pr doping content were synthesized, and their TWC activities and SO2 resistance performance were tested. The prepared catalysts were also systematically characterized. The collected results suggested that two kinds of defects in Ni~(Ce-Zr)O2/Al2O3 were generated after Pr doping, including oxygen vacancies (Ov) and lattice distortion, whose types and concentrations depended on the Pr doping content. The results also indicated that Ov play a vital role on the catalytic performance, whereas lattice distortion play a small effect on it. In addition, it is found that the concentrations of Ov in as-prepared catalysts determined their TWC catalytic performance, the Ni~(Ce6Zr3Pr1)O2/Al2O3 catalyst with most Ov concentrations performed superior three-way catalytic performance at 200~600℃ and also exhibited excellent anti-sulfur poisoning performance after introducing 100ppm SO2 at 600℃. This is because Ov not only promoted the dispersion of NiO, accelerating the migration and diffusion of bulk oxygen to form active oxygen species, thus promoting the adsorption and oxidation of CO and HC species on the catalyst, but also the Ov can weaken the N-O bonds boosting the dissociative adsorption and reduction of NO species.
2023 Vol. 43 (10): 5157-5169 [Abstract] ( 151 ) [HTML 1KB] [ PDF 1853KB] ( 2185 )
5170 Characteristics and potential to strengthen anaerobic digestion of hydrochar
GENG Tao, ZHAO Li-xin, YAO Zong-lu, SHEN Rui-xia, YU Jia-dong, LUO Juan
Anaerobic digestion (AD) offers an attractive method to reduce the negative impact of organic waste existing in the environment such as stalk, animal manure and municipal sludge. The biogas, digestate and slurry generated have great application value in energy, agriculture, environmental protection and other fields. However, AD has some problems such as the lag phase, the inhibition effect caused by ammonia nitrogen, VFA and so on, and low methane content in biogas. Hydrochar is the solid product of hydrothermal carbonization of biomass which is converted to porous multi-functional carbon-based material with the presence of subcritical water in the sealed equipment under the effect of heat and pressure. The potential benefits and applications of hydrochar have received significant attention with complex pore structures and high density of oxygen-containing functional groups. There is a comprehensive strengthening effect on AD including shortening the lag phase, alleviating the inhibition, favoring electron transfer between microbes, and enhancing the CH4 production with the addition of hydrochar. Specifically, it was brought together recent advances made in the area through a systematic and critical review of the characteristics, modification, and strengthening effect on AD of hydrochar. The potential and limitations involved in the hydrochar application on AD were pointed out with suggestions for further research to exploit the great potential of AD on treating agricultural wastes.
2023 Vol. 43 (10): 5170-5180 [Abstract] ( 243 ) [HTML 0KB] [ PDF 1486KB] ( 6094 )
5181 Effects of carbon, nitrogen and phosphorus in fermented thermal-hydrolyzed sludge on polyhydroxyalkanoates production
HE Yun, LI Kui-xiao, JIANG Da-wei, CHANG Jing, HAO Shan, WANG Gang, WANG Jia-wei
Based on the domestication of the acid liquor of fermented thermal-hydrolyzed sludge, the mixed microbial cultures for producing PHA were obtained and its characteristics were explored. The influence mechanism of feeding method and composition (i.e., N, P, non-VFAs) of the acid liquor on the PHA yield and microbial activity were also investigated. Specifically, the predominant Brachymonas accounted for 45% of the unique mixed microbial cultures that yield PHA. The PHA productivity was improved from 22wt% to 25wt% by limiting the concentration of NH+ 4-N in the acid liquor. By limiting the concentration of non-VFAs, not only the PHA productivity was improved 27% but also the production efficiency was improved 25%. Microbial activity was not effected significantly by non-VFAs、NH4+-N and PO43--P in acid liquor while was obviously restrained by volatile fatty acids (VFAs) with high concentration. To mitigate inhibition of VFAs and improve the PHA yield, intermittent feeding (5times) strategy was used. The PHA yield was effectively improved to 34wt% compared with 28wt% in disposable feeding. Furthermore, the PHA yield was improved by increasing the VFAs proportion in the acid liquor and optimizing the feeding method. The production of PHA by microorganism from fermented thermal-hydrolyzed sludge will be great promise in future industrialization.
2023 Vol. 43 (10): 5181-5187 [Abstract] ( 166 ) [HTML 0KB] [ PDF 695KB] ( 1522 )
5188 Effect of chlorine on cell-surface interaction and bacterial adhesion behavior
CAI Yin-nuo, LIU Li, CHEN Guo-wei, ZHONG Shu-ying
In this study, disinfectant-shaped bacterial adhesion behaviors on pipes with various materials and roughness were examined to underpin the underlying mechanisms of bacterial surface attachment in drinking water. The interaction between bacteria and rough surfaces was analyzed via XDLVO (extended-Derjaguin-Landau-Verwey-Overbeek) theory based on surface thermodynamics. The results showed that chlorine (≤ 1.0mg/L) significantly promoted bacterial adhesion on pipe surfaces (with a 4~6times increment compared to the situation with no chlorine). Besides, bacterial cells tended to colonize the plastic surfaces and increasing surface roughness can further promote surface adhesion. The XDLVO-based theoretical analysis showed that 1.0mg/L chlorine increases the acid-base and van der Waals interaction terms between bacteria and pipe surfaces, which encourages surface adhesion behaviors. Increasing surface roughness further intensifies cell-surface interactions. Compared with stainless steel pipes, polyvinyl chloride and polyethylene surfaces can elevate the interaction energy with bacterial cells, particularly at 1.0mg/L chlorine, which further contributes to bacterial surface attachment and aggregation.
2023 Vol. 43 (10): 5188-5195 [Abstract] ( 141 ) [HTML 0KB] [ PDF 560KB] ( 1594 )
5196 Study on the electrochemical reduction of nitrate using a modified Cu-Pd bimetallic electrode
WANG Chang, LIU Ji-ming, WANG Yong-heng, LU Xin-yu
A NF/CNTs/Cu-Pd bimetallic composite electrode was effectively synthesized using the cathodic electrodeposition technique. The objective was to achieve efficient electrocatalytic reduction of nitrate in wastewater. SEM-EDS, XRD, and XPS analysis confirmed the successful deposition of Cu-Pd nanoparticles onto the nickel foam (NF) substrate. The efficacy of NO3--N and TN removal in simulated water was investigated by manipulating various factors, including current density, initial pH value, initial nitrate concentration, and Cl- concentration. The approach was also applied to actual saline wastewater to validate its feasibility. The results showed that NF/CNTs/Cu-Pd exhibited effective NO3--N removal capabilities without Cl-, while TN removal efficiency was relatively modest, with NO3--N primarily converted into NH4+-N. However, in the presence of Cl-, both NO3--N and TN were efficiently removed. The optimal reaction conditions were determined to be a current density of 30mA/cm2, an initial pH value of 7, an initial concentration of 50mg/L, and a chloride ion concentration of 2.0g/L. Under optimal conditions, the removal efficiencies of NO3--N and TN reached 100% and 97.2%, respectively. The presence of dissolved organic matter (DOM) in actual wastewater could impede NO3--N removal. After removing the DOM, the removal efficiency of NO3--N decreased to 95.5%, and the TN removal efficiency declined to 85.6%.
2023 Vol. 43 (10): 5196-5207 [Abstract] ( 160 ) [HTML 0KB] [ PDF 1832KB] ( 1622 )
5208 Starting law and pollution contribution characteristics of stratified sediment scouring in sewage pipes
HAN Jian-shuang, SHI Xuan, ZHANG Jian-feng, HUI Yi-lian, JIN Peng-kang
To explore the distribution characteristics of pollutants in the vertical section of sewer sediment, the mechanism of layered erosion initiation and pollution contribution characteristics of sediment under gradient erosion intensity were revealed. It could be an important foundation for scientific control of combined overflow pollutants (CSO). In this study, a pilot sewer system which could simulate the sediment erosion process was established. And based on the theory of layered distribution of sewer sediment, the characteristics of particle size, carbon and nitrogen pollutants were revealed. The results show that the theoretical critical shear stress under different layered particles increases from 0.038N/m2 to 0.261N/m2 with the increase of particle size. As the flow shear force increased from 0.1N/m2 to 0.3N/m2, the contribution rate of sediment of TCOD increased from 6.4% to 46.3%; the contribution rate of TN increased from 25.3% to 40.6%; and TP decreased from 42.9% to 25.1%. Moreover, in comparison with the attachment content of various pollutants, as the flow intensity increased, the proportion of suspended solids that start flushing was the highest among organic pollutants. It can be concluded that, the particle size has a significant impact on the distribution of pollution load of pollutants, and the distribution of pollution load has a correlation with the concentration changes of overflow pollutants caused by water flow erosion. Thus, clarifying the flow intensity and concentration changes of overflow pollutants caused by layered sediment erosion in pipelines can help effectively control water pollution.
2023 Vol. 43 (10): 5208-5213 [Abstract] ( 135 ) [HTML 0KB] [ PDF 1034KB] ( 1830 )
5214 Degradation of CIP in mariculture wastewater by PTCN/CaO2/vis system: Mechanism and fate
ZENG Yu-feng, NIU Meng-yang, CHEN Ping, QIU Yan-nan, LIN Yi-jie, XIAO Zhen-jun, FANG Zheng, YU Zong-shun, LIN Zi-feng, LUO Jin, Lü Wen-ying, LIU Guo-guang
Abuse of antibiotics presents a significant threat to both human health and environmental ecology. To combat this issue, a phosphorus-doped tubular carbon nitride (PTCN)/CaO2/visible light(vis) system would be developed and applied to effectively remove the pollutant ciprofloxacin (CIP) from mariculture wastewater. Meanwhile, the reaction mechanism of this system and the environmental fate of the antibiotic CIP would be investigated in this work. Experimental results indicated that the PTCN/CaO2/vis system exhibited excellent potential for degradation of antibiotics. The observed apparent degradation rate constant (kobs) of CIP under the experimental conditions was 7.15×10-2min-1. Single-factor experiments had revealed that the system exhibited enhanced CIP degradation efficiency in acidic conditions. However, the presence of co-existing factors in water did influence the system's ability to degrade CIP. Moreover, as the concentration of CIP increases, the system's capacity to degrade pollutant decreases. Additionally, the system displayed superior recyclability, maintaining a degradation rate of 82.5% after five cycles of PTCN. The process of CIP degradation by the system was primarily dominated by the active ingredient O2·-, while the active substances 1O2 and h+ also contributed to the process. As the target pollutant CIP underwent decarboxylation and piperazine epoxidation, a majority of the intermediate products produced were found to be more environmentally friendly towards aquatic organisms. Finally, by prolonging the system's degradation time, the antibacterial activity of CIP could be effectively eliminated.
2023 Vol. 43 (10): 5214-5225 [Abstract] ( 175 ) [HTML 0KB] [ PDF 1793KB] ( 2602 )
5226 Simultaneous nitrification and phosphorus removal of aerobic granular sludge in AOA-O mode
ZHANG Jie, YANG Jie, LI Dong, GAO Xin
In order to construct a simultaneous nitrification endogenous denitrification phosphorus removal granular sludge system, four groups of anaerobic/aerobic/anoxic (AOA) and AOA-O with different post-aeration time (5min, 10min, 20min) sequencing batch reactors, were set up in this study to explore the enrichment of sludge granulation and denitrifying phosphate-accumulating organisms (DPAOs) in different operation modes. The results showed that the post-short-term aeration reactor granular sludge had dense structure and good precipitation performance, which could enhance the storage of internal carbon source and secrete more eextracellular polymeric substance (EPS), and had higher nitrogen and phosphorus removal rate and DPAOs ratio. The biomass of R3was the highest and the average particle size was the largest (986μm) when the short-term aeration time was 10min. The particles were mature and stable. Batch experiment and three-dimensional fluorescence analysis showed that 45.85% of the phosphorus accumulating bacteria were DPAOs and EPS content was the highest. During stable operation, the COD, TN and TP removal rates of R3 were 94.13%, 89.41% and 96.11%, respectively, and the storage efficiency of internal carbon source was 98.09%, showing good treatment performance.
2023 Vol. 43 (10): 5226-5234 [Abstract] ( 167 ) [HTML 0KB] [ PDF 1950KB] ( 1889 )
5235 Inversion of suspended sediment concentration in rivers of Suzhou based on UAV remote sensing and ensemble learning
YU Cheng, TANG Yi, PAN Yang, YI Hong-chen, GU Yi-ping, ZHU Feng, SHI Jiao-yang
The inversion of suspended sediment concentrations of urban rivers by remote sensing has important practical significance for water environmental management. To address the problem of overfitting in individual models, this study attempts to improve the accuracy and generalizability of the inversion model by realizing the complementary advantages among four different ensemble learning strategies. Ensemble learning inversion models were established based on multispectral remote sensing images collected by unmanned aerial vehicles and field-measured suspended sediment concentrations of Suzhou in this study. Four commonly used regression methods and three classic machine learning methods were used to validate the effectiveness of the ensemble learning strategies. The results demonstrate that the ensemble learning strategies effectively mitigate the limitations of individual models, substantially improving the accuracy and generalizability of the remote sensing inversions. The stacking strategy achieves the best performance with a validation set's coefficient of determination of 0.821, show casing a 38.21% enhancement compared with the regression methods and a 16.79% improvement compared to the individual machine learning methods. The absolute error of the ensemble learning method is concentrated on small values, with its mean and median absolute errors surpassing the traditional methods. This study can improve the accuracy of urban suspended sediment concentration inversion and provide guidance for unmanned aerial vehicle remote sensing of river suspended sediment concentration inversion.
2023 Vol. 43 (10): 5235-5246 [Abstract] ( 203 ) [HTML 0KB] [ PDF 3357KB] ( 1657 )
5247 Migration behavior of the surfactant in aquifers with different medium sizes
YAO Meng, CHEN Xu-yang, YUAN Qian, XUE Jin-juan, WANG Ming-xin
Based on the limited site experience of the surfactant injection parameters during surfactant-enhanced air sparging (SEAS), the migration behavior of the surfactant in aquifers with different medium sizes was studied by light transmission visualization technology. The results showed that the influence radius of the surfactant injection in the aquifers with different medium sizes increased logarithmically, and its influence area increased linearly, and its migration behavior was obviously affected by the SDBS injection concentration. There was a critical injection concentration (Ci), which migrated upward when it was less than the Ci. When it was greater than or equal to the Ci, it migrated downward. When it was close to the Ci, its migration rate was the lowest, while the further away from the Ci, the greater the migration rate. In addition, in gravel and coarse sand aquifers, the migration process was mainly affected by the buoyancy and gravity effect. However, in the medium aquifer, its migration was mainly affected by the adsorption effect, and its migration range was small. The above research is beneficial for the precise design of the surfactant injection parameters to improve the contaminant removal efficiency during SEAS remediation.
2023 Vol. 43 (10): 5247-5256 [Abstract] ( 187 ) [HTML 0KB] [ PDF 2152KB] ( 1585 )
5257 Groundwater quality assessment and index optimization of water quality monitoring in the water source area of Changbai Mountain
GU Zhi-qi, BIAN Jian-min, WANG Yu, MA Li-xin, SUN Xiao-qing, RUAN Dong-mei
This study chose Antu County, the water source area of Changbai Mountain as the study area. the hydrochemical characteristics and formation mechanism of groundwater in the study area was analyzed. The cloud model based on entropy weight was used to evaluate the groundwater quality. Furthermore, an optimization model of water quality index was constructed by coupling random forest and stepwise multiple linear regression analysis to determine the key indicators of groundwater source security monitoring. The results showed that the primary water chemistry type of groundwater in the study area was HCO3-Mg·Na·Ca type, which was mainly controlled by the rock weathering and dissolution effects. About 74% of groundwater samples were classified as Class Ⅰ-Ⅲ. The R2 and RMSE values of the best index optimization model were 0.6333 and 0.726, respectively. F-, Na+, TDS and Cl- were identified as the key indicators of groundwater quality monitoring in the study area. This optimized water quality index can effectively reduce monitoring costs and provide scientific basis for guaranteeing the safety of water sources.
2023 Vol. 43 (10): 5257-5264 [Abstract] ( 237 ) [HTML 0KB] [ PDF 1057KB] ( 2376 )
5265 Tracing and estimation of nitrate sources based on hydrochemistry and nitrogen and oxygen isotopes in karst mountainous water: A case study of the Pingzhai reservoir
WANG Yan-bi, ZHOU Zhong-fa, KONG Jie, WANG Cui, ZOU Yan, ZHANG Fu-qiang, LI Li
Pingzhai reservoir is located in the karst mountainous area. It is one of the important irrigation and drinking water reservoirs in Guizhou province, the water environment quality has a profound impact on the production and life of residents. Taking Pingzhai reservoir as the research object, this essay adopted hydrochemical analysis method, nitrogen and oxygen dual isotope technology combined with MixSIAR model to quantitatively identify the contribution rate of each pollution sources of nitrate in the water body of the study area. The results showed that:(1)Dissolved inorganic nitrogen in rivers and reservoir water bodies mainly exists in the form of nitrate nitrogen, which is manifested in time as flat season>wet season>dry season. In space, there is a significant difference in concentration in the upstream of each river, while the concentration in the downstream is close to that in the reservoir area. The nitrate concentration in the wet season before the dam is relatively high.(2)The conversion of nitrate in the water body of the research area is mainly through nitrification. The main sources are domestic sewage, livestock manure, and soil organic nitrogen during the dry and flat seasons, while chemical fertilizers are the mail sources during the wet season. (3) In terms of nitrate sources, the contribution rates of domestic sewage and livestock manure in the reservoir area were higher than that of rivers, and the contribution rates of soil organic nitrogen and chemical fertilizer were lower than that of rivers. In terms of contribution rates of domestic sewage and livestock manure, the numbers are 59.3% and 70.8% in the dry season of rivers and reservoirs respectively, and 58.3% and 72.6% respectively during the normal water period of rivers and reservoirs. And the number is quite small during wet season. From the perspective of soil organic nitrogen contribution rate and chemical fertilizer contribution rate, the contribution rate during the wet season is higher than that during the dry and flat season. The contribution rates of soil organic nitrogen from rivers and reservoirs during the wet season are 35.1% and 32.8% respectively, and the contribution rates from chemical fertilizers are 36.4% and 30.7% respectively. The protection of water environment quality in Pingzhai Reservoir should focus on strengthening the control of domestic sewage discharge for urban and rural residents, especially the reduction of the discharge of domestic sewage and improvement of centralized sewage treatment of the Nayong River basin. Besides, in order to protect the water environment, it is necessary to enhance the prevention and control of agricultural pollution in various watersheds, reasonably dispose of the discharge and stacking of livestock and poultry manure from individual livestock breeding in each watershed, avoid pollutants from entering the water body and causing pollution, and provide guarantees for the safety of drinking water and ecological protection of residents.
2023 Vol. 43 (10): 5265-5276 [Abstract] ( 229 ) [HTML 0KB] [ PDF 2638KB] ( 1698 )
5277 Enrichment mechanism and dynamic variation characteristics of fluorine and arsenic in groundwater of western Songnen Plain
DENG Yuan-dong, YE Xue-yan, WU Ya-min, DU Xin-qiang
In order to further reveal the the evolutionary trends of fluorine and arsenic in groundwater in the western part of the Songnen Plain, a comprehensive investigation was conducted on the current condition of fluorine and arsenic concentrations in groundwater, focusing on Tongyu County as a case study. Water quality data were analyzed using ion-ratio diagrams and self-organizing mapping networks. The results show that fluorine content of the phreatic water was governed by the precipitation and dissolution of the water-bearing medium, and evaporation and concentration had a certain influence on the formation of most of the shallow, high and low fluoride groundwater, but were not the dominant role in the formation of high fluoride groundwater. The dissolution of iron and manganese oxides from water promoted the release of As from shallow and deep groundwater. The overall level of the fluoride concentration in shallow groundwater in the mid-eastern part of the region has decreased since 1995, which may be attributed to factors such as the depletion of groundwater levels and decreased evaporation resulting from extensive local groundwater extraction. Although the deep, high fluoride groundwater did not show a significant change, its spatial coverage has expanded; This may be related to the leakage of shallow, high fluoride groundwater into the pressurized aquifers through the broken well pipes. The overall concentrations of arsenic in shallow groundwater in the central and northeastern regions from 1995to 2021 significantly exceed the WHO guideline values for drinking water. Although the concentrations of high-arsenic groundwater in deeper layers have remained relatively stable, they exhibit a wider distribution, more enriched zones, and greater contamination compared to high arsenic zone in shallow groundwater. This may be related to the reducing conditions in the pressurized aquifer that promoted the release of arsenic. Therefore, the exploitation of deep groundwater in Tongyu County should be conducted with cautions, taking into consideration of the areas affected by high levels of arsenic contamination. The exploitation level should be carefully determined to prevent the intrusion of polluted water. Additionally, attentions should be given to address the potentially cascading contaminations resulting from the leakage and destruction of wells.
2023 Vol. 43 (10): 5277-5290 [Abstract] ( 146 ) [HTML 0KB] [ PDF 3458KB] ( 1180 )
Solid Waste
5291 Mechanism and regulation method of humic acid formation in composting-a review
CHANG Yuan, LI Ruo-qi, LI Jun, ZHAN Ya-bin, WEI Yu-quan, XU Ting, LI Ji
The aim of this study was to review the mechanism of humic acid formation and the regulation method for improving the humification degree by process parameter optimization, the exogenous additives, and so on, in composting. The mechanisms of various regulation methods for accelerating humic acid formation process were also discussed, which provided theoretical basis for the development of fast composting technologies. Various regulatory methods may be interacted in applications due to the complex dynamic physiochemical environment factors in composting. Therefore, it is necessary to establish an integrated relationship among more factors related to humic acid formation based on practical compost production process. The future regulating methods will help to improve the quality of composting products.
2023 Vol. 43 (10): 5291-5302 [Abstract] ( 313 ) [HTML 0KB] [ PDF 2418KB] ( 2519 )
5303 Adsorption performance of per- and polyfluoroalkyl substances (PFAS) on hydrochar derived from food waste
CHEN Fan, CHEN Jiang-liang, LIU Xue-mei, ZHI Yue, LI Wei, WANG Xiao-ming
This study focused on the preparation of activated hydrochar (AC) from high water content food waste through hydrothermal carbonization combined with high temperature activation. Multiple methods were used to characterize the physicochemical properties of the AC. Adsorption experiments and kinetic analysis were conducted to investigate the adsorption behavior of per- and polyfluoroalkyl substances (PFAS), a class of emerging pollutants of global concern, with the aim of providing insights for waste treatment and pollution control. The results showed that the AC possessed a high specific surface area (206.97m2/g) and hydrophobic surface properties, which facilitated the adsorption of PFAS. At environmentally relevant concentrations (~40μg/L), the adsorption distribution coefficients (log Kd) of PFAS on AC ranged from 2.38 to 6.49L/kg, higher than those reported for other biochars. This highlighted the favorable adsorption performance of AC towards the studied PFAS. The Langmuir isotherm adsorption model and the Elovich kinetic model effectively described the adsorption process, suggesting that PFAS adsorption on AC occurred similarly to monolayer chemisorption. Additionally, for PFCA and PFSA, the log Kd values exhibited a positive correlation with the perfluoroalkyl chain length, indicating the significance of hydrophobic interactions in the adsorption of PFAS on AC.
2023 Vol. 43 (10): 5303-5309 [Abstract] ( 185 ) [HTML 0KB] [ PDF 1001KB] ( 2574 )
5310 Feammox based on the resource utilization of waste iron sludge and its mechanism
LI Hao, WANG Jin, MA Ding, FANG Jin-tao, YUE Zheng-bo
Lightweight sintered ceramsite were prepared using iron-carbon microelectrolysis sludge as raw material and filled in an anaerobic bioreactor. This process achieved the resource utilization of waste iron sludge and the anaerobic oxidation of low C/N wastewater. After 60 days of acclimation, the effluent water reached a stable state, with an average removal rate of NH4+-N close to 100% and an average removal rate of TN of 14.19%. NH4+-N was anaerobically oxidized in the reactor, and NO3--N became the main form of nitrogen in the effluent. Analysis of the Fe-N coupling mechanism in the reactor showed that biochemical processes such as organic hydrolysis, iron reduction, and NDFO reactions primarily occurred at the bottom, Feammox and NDFO reactions mainly occurred in the middle, and NDFO reactions mainly occurred at the top.
2023 Vol. 43 (10): 5310-5319 [Abstract] ( 178 ) [HTML 0KB] [ PDF 2261KB] ( 1761 )
Soil Pollution Control
5320 Remediation of pyrene-contaminated soil using electro-Fenton in a slurry-phase: the characteristics analysis
XU Wen-di, WANG Yi-han, GUO Shu-hai
The electro-Fenton (EF) process is a promising technology for removing contaminates from soil or water. However, there are many differences between soil and water during the EF remediation process. Therefore, the effect of EF process on the remediation of pyrene in contaminated-soil by a slurry-phase was investigated, especially the effect of the optimum parameters on hydroxyl radical (·OH) generation and pyrene degradation, including soil organic matter, soil-water distribution coefficient (Kp), surface tension and different soil particle-size. The results demonstrate that under optimum operating conditions (an aeration rate of 500mL/min, initial slurry pH of 3.0 and voltage gradient of 2V/cm), pyrene degradation of 81.83% and ·OH concentrations of 36.65 μmol/L were achieved. Both the content and the composition of the soil organic matter changed, with the changing of distribution of pyrene. Moreover, it showed a lower degradation of pyrene and a lower generation of ·OH during the latter period of the experiment, because of the change of pH and H2O2. In addition, the mass transfer of soil was enhanced by the slurry-phase system. And the high degradation of pyrene (89.26%) on the fine particle-size (< 0.005mm) of soil had occurred. Ultimately, these results have shown that incorporating the EF process into a slurry-phase reactor will create an efficient technology for the remediation of organic-polluted soil.
2023 Vol. 43 (10): 5320-5327 [Abstract] ( 158 ) [HTML 0KB] [ PDF 588KB] ( 1459 )
5328 Effects of attapulgite-based composites on soil improvement——Take desert-oasis farmland soil as an example
FENG Zhi-zhen, YAN Hong, LU Yu-xin, XU Qian, BAI Ya-ni, ZHAO Wen-juan
Effects of attapulgite/biochar composite and its individual component on soil aggregate and corn (Zea mays L.) yields at different application levels were studied in desert-oasis farmland soil in Linze County, middle reaches of Heihe River. Results showed that the composite reduced the gravel particles (>1mm), coarse sand particles (1~0.25mm), fine sand particles (0.25~0.1mm), and grade fine sand particles (0.1~0.05mm), while increasing the coarse silt particles (0.05~0.02mm), fine silt particles (0.02~0.002mm) and clay particles (<0.002mm). The soil aggregate content of >2mm and the average weight diameter (MWD) were gradually increased with an increase in the application dosage of composite. When the application dosage of composite reached a high level(12t/hm2), the MWD reached the maximum of 6.24mm, which increased 49.6% comparing to the control treatments. With the increasing application dosage of composite, corn yields firstly increased and then decreased. When medium application dosage was applied(8t/hm2), the yield reached 18352kg/hm2, increased 56.9% comparing with the control treatment. To conclude, the attapulgite/biochar composite promoted the formation of soil aggregate structure by regulating soil particle distribution, and further improved soil structure and physicochemical properties. On the other hand, the nutrients of the composite affected the soil chemical properties. The corn yields were increased by the change of soil physicochemical properties after applying attapulgite/biochar composite. The composite had greater effect than individual in improvement of farmland soil in desert-oasis, had better development and utilization value.
2023 Vol. 43 (10): 5328-5338 [Abstract] ( 147 ) [HTML 0KB] [ PDF 3030KB] ( 1272 )
5339 Environmental footprint analysis of contaminated site remediation based on SitewiseTM and SEFA methods
ZHOU You, XIN Yi, FENG Tong, SANG Chun-hui, XIAO Meng, ZHANG Hong-zhen, LI Xiang-lan, YANG Xin-tong, DONG Jing-qi
In this study, the SitewiseTM and SEFA tools were used to analyze environmental footprint of remediation activities of a contaminated site in a northern China city, and compared the methodology, input and output indicators, scope of application and suggestions for further development. The results showed relatively high consistency in simulation of greenhouse gas emissions and energy consumption, but there were still certain differences in the evaluation results of air pollutants including NOx, SOx and PM mainly due to the significant difference in the emission factors of the built-in databases. Both tools can identify the key remediation activities that cause environmental impact, and can also compare different remediation solutions at the same time. However, both tools have certain limitations:the evaluation of economic and social indicators is insufficient; there are no sensitivity analysis functions; the indicators and built-in database may not be applicable for certain real situations. It is suggested to research and develop a suitable environmental footprint tool for domestic practical use, so as to provide further support for carbon and environmental pollution reduction in remediation activities.
2023 Vol. 43 (10): 5339-5348 [Abstract] ( 199 ) [HTML 0KB] [ PDF 1043KB] ( 1596 )
5349 Pollution characteristics of soil heavy metals with the irrigation of treated mine water
ZHANG Li-xing, ZHOU Rui-ping, HAI Chun-xing, YUE Da-peng
In order to investigate the influences of treated mine-water irrigation on the spatial distribution and possible pollution of soil heavy metal, a top-down "terrace style" irrigation experiment was conducted on a long and gentle slope in the field and a set of key heavy metal element (As, Cr, Cu, Ni, Pb and Zn) were analyzed and compared for irrigated and unirrigated slope. The analysis was after a three-year controlled experiment, in which the treatment group slope was irrigated with treated mine-water whereas the control group slope not irrigated. Soil pollution introduced by heavy metal accumulation was assessed using the geo-accumulation index method. The results showed that soil heavy metal content on both sites were lower than the risk screening values for soil contamination of agricultural land. The means of Cr, Cu, Ni, Pb and Zn in the irrigated slope were lager than the corresponding background values of Inner Mongolia, and were significantly higher than those in the unirrigated slope (P< 0.05). On both sites, the difference in heavy metal contents was not significant between surface and deep soils. However, it was that Cr, Cu, Ni, Pb and Zn had a significant accumulation effect in the upper and middle sections of the irrigated slope compared with corresponding sections of the unirrigated slope. In the lower sections of both sites, the difference in heavy metal contents was miner. A further geo-accumulation index assessment on heavy metal pollution of surface soil (0~20cm) of both sites revealed that the levels of Cr, Cu, Ni, Pb and Zn in the upper and middle sections of irrigated slope reached the threshold value for slightly polluted conditions. Slight as pollution appeared in some of the samples from unirrigated slope whereas all other heavy metal elements from this site were within the safety values. It is concluded that treated mine-water irrigation resulted in accumulation of heavy metals in the upper and middle sections of irrigated slopes which was a significant environmental risk. The current study provides useful scientific data for recycling of mine water and sustainable use of water resources.
2023 Vol. 43 (10): 5349-5358 [Abstract] ( 145 ) [HTML 0KB] [ PDF 866KB] ( 1388 )
5359 Environmental footprint analysis of ectopic soil remediation based on SEFA method: A case study of a steel plant
SANG Chun-hui, YANG Xin-tong, LI Xiang-lan, ZHANG Hong-zhen
A study was conducted to analyze environmental footprints of heterotopic combination remediation schemes using SEFA (Spreadsheets for Environmental Footprint Analysis, EPA, version 3.0) algorithm at a steel contaminated site in Hefei, Anhui Province. Three schemes were included:(1) soil leaching + chemical oxidation + co-combustion in cement kiln, (2) stabilization + chemical oxidation + thermal desorption + remote landfill, (3) biodegradation + stabilization. Results showed significant differences in environmental footprints among the three remediation schemes. In terms of the green and sustainable restoration (GSR) elements, Scheme 3 yielded the smallest environmental footprint, i.e., energy consumption of 21808×104MJ and air pollution of 17,300tCO2 e. The overall environmental footprint of remediation of 1m3 of organic contaminated soil followed an order of chemical oxidation < biodegradation < thermal desorption, showing greenhouse gas emission as 0.05, 0.09 and 0.17tCO2 e/m3, and energy consumption as 949.55, 1677.54, 3049.11MJ/m3, respectively. For remediation of heavy metal contaminated soil, landfill caused the smallest environmental footprint in terms of energy consumption and greenhouse gases emissions. Regarding air pollutant emissions, stabilization remediation technology led to the smallest environmental footprint.
2023 Vol. 43 (10): 5359-5367 [Abstract] ( 179 ) [HTML 0KB] [ PDF 2105KB] ( 1658 )
Environmental Ecology
5368 Impacts of human activities on net nitrogen input under different ecological type zones—A case study in agricultural-pastoral ecotone of Northern China
LIU Huan, LEI Qiu-liang, DU Xin-zhong, AN Miao-ying, LIU Xiao-tong, QIU Wei-wen, WU Shu-xia, LIU-Hong-bin
This study aimed to investigate the impacts of human activities on net Nitrogen (N) input under different ecological type zones of the agricultural-pastoral ecotone in Northern China. Based on Net Anthropogenic Nitrogen Input (NANI) model, statistical data and relevant parameters collected from 7 provinces and 23 prefecture-level cities within the agricultural-pastoral ecotone were analyzed to determine the spatiotemporal distribution characteristics and influencing factors of NANI from 1985 to 2020. The results showed that the trend of NANI in the region initially increased and then declined from 1985 to 2020, and Hebei Province contributed the highest to the NANI value. The NANI trends in the hilly and gully erosion area of Loess Plateau and the northern agricultural-pastoral ecotone inter-annual were similar, while the NANI values in the water source conservation zone of Beijing-Tianjin-Hebei region and the soil desertification and degradation area along the Great Wall appeared to show an upward trend. The overall spatial distribution of NANI values presented a gradually decreasing characteristic from northwest to southeast. In terms of input components, the largest contribution source in the entire study area was N fertilizer use (30.34%~56.29%), followed by atmospheric N deposition (31.20%~47.23%). The key input components in the hilly and gully erosion area of Loess Plateau were N fertilizer application and food/livestock feed N input (accumulating to 76.46%~85.14%). The two factors that had the greatest effect on NANI values in the northern farming-pastoral ecotone were population density and the quantity of livestock and poultry. Therefore, farming systems restructuring in the agricultural-pastoral ecotone of Northern China should integrate with zoning governance strategy, adjusting N fertilizer use schemes, livestock and poultry breeding modes to promote the deep consolidation between regional agriculture and the ecological environment.
2023 Vol. 43 (10): 5368-5377 [Abstract] ( 139 ) [HTML 0KB] [ PDF 1400KB] ( 1825 )
5378 Mechanism of groundwater salinization in the oasis zone of the Tarim Basin
LU Han, ZENG Yan-yan, ZHOU Jin-long, SUN Ying, MA Chang-lian
Durov diagram, PMF model, Gibbs diagram, ion ratio and saturation index method were used to analyze 1326 groundwater samples collected from 2016 to 2018, revealing the sources and driving forces of high salinity groundwater formation. The results showed that the proportion of brackish water and saline water in the oasis zone was 37.2% and 19.1%, respectively, and the hydrochemical type of groundwater was mainly SO4-Cl. The continuous dissolution of evaporate rock such as halite and gypsum in brackish water, saline water, salt water and brine was the main driving factor for the formation of high salinity groundwater, which was also confirmed by the extremely significant positive correlation between Cl-, SO42-, Na+ and TDS (P<0.001), and between SI values of halite, gypsum and TDS(P<0.001). The poor groundwater dynamic conditions, fine-grained lithology and weakly alkaline hydrochemical environment in the alluvial plain area created favorable conditions for the enrichment of salts in groundwater, evaporation concentration and cation exchange were secondary factors in the formation of highly salinity groundwater. Due to the influence of human activities, high TDS phreatic water in confined groundwater areas infiltrated and recharged confined groundwater along the well wall, which was also a potential factor to intensify the salinization of deep groundwater.
2023 Vol. 43 (10): 5378-5389 [Abstract] ( 155 ) [HTML 0KB] [ PDF 4254KB] ( 1463 )
5390 Synergistic changes of organic and inorganic carbon burial in response to eutrophication in Yilong Lake over the past 100 years
LI Ping, CHEN Guang-jie, KONG Ling-yang, HUANG Lin-pei, WANG Xu, YANG Guan-shao, SUO Qi, LI Jing, WANG Lu, HAN Qiao-hua, ZHOU Qi, GUO Wen, LI Rui, ZHANG Tao
Carbon burial and its dynamic change in lakes play an indispensable role in the global carbon budget and residual land sink. Carbon sequestration in hard water lakes and other inland waters is deemed to be an important sink process owing to carbonate weathering coupled with aquatic photosynthesis, which stimulates continuous organic carbon and inorganic carbon burial. However, existing assessment paradigms are mainly based on organic carbon, lacking a comprehensive understanding of inorganic carbon burial and its synergistic change with organic carbon. Here, the history of carbon burial fluxes over the past century through multi-proxy and spatial sediment surveys of Yilong Lake in the karst area of Yunnan province was analyzed, in combination with 210Pb and 137Cs chronological profiles, for uncovering the patterns and mechanisms of synergistic changes in organic and inorganic carbon burial. The results showed that the allochthonous primary productivity in Yilong Lake has been significantly elevated due to nutrient input caused by watershed cultivation (e.g., enrichment of sediment nitrogen and phosphorus contents), with sediment pigment content increasing from 7.02μg/g in~1900 to 38.99μg/g in~2020. The accumulation rates of both organic and inorganic carbon showed a continuous trend of increasing and a high degree of synergistic changes (r=0.99,P<0.001). Regression analysis further showed that algal biomass was the main factor in driving the accumulation rates of both organic and inorganic carbon (R2=0.33~0.91, P<0.001). This indicated that algal photosynthesis and the "biological carbon pump" effect have largely controlled the processes of carbon burial. With the general decline of allochthonous watershed export (as evidenced by a decline of sediment magnetic susceptibility signal and C:N ratio) and a continuous increase of algal biomass, more allochthonous organic carbon can be transformed to authigenic carbonates (as evidenced in a sustained depletion of δ13CTIC) during the decaying and mineralization of organic matters, enhancing the synergistic increase in both organic and inorganic carbon burial. These results suggested a highly synchronous increase in the long-term fluxes of organic and inorganic carbon burial in response to lake eutrophication, highlighting the increasingly coupled processes in the burial of organic and inorganic carbon, and an increased rate in sediment carbon cycling and recycling. Therefore, under the continuing impact of human activities and climate change, refined assessments of carbon sink in karst lakes need to highlight the pattern of inorganic carbon cycling and its dynamic role in the flux and stock of terrestrial carbon.
2023 Vol. 43 (10): 5390-5402 [Abstract] ( 214 ) [HTML 0KB] [ PDF 2166KB] ( 2852 )
5403 Preliminary study on the changes and influencing factors of greenhouse gases during the purification of eutrophic water by plants
YANG Ke, LIU Li-xiang, HAN Yong-wei, DENG Hao-dan, ZHENG Yu-ping, ZHANG En-xiang
Water eutrophication was simulated by artificially adding nitrogen and phosphorus, and setting up five purification treatments with aquatic plants. In our study, the CO2 effluxes at the water-air interface ranged from 19.12 to 395.19 mg/(m2·h). The CO2 effluxes decreased slowly, and then increased. The CH4 and N2O effluxes at the water-air interface ranged from 0.009 to 0.96mg/(m2·h) and 0.024 to 6.48mg/(m2·h), respectively. The temporal patterns of CH4 and N2O effluxes were similar, which slowly increased, and gradually decreased, then eventually increased once again. The results of multiple stepwise regressions showed sediment DOC, sediment NH+ 4-N, pH, DO, Chl.a in the water were significant predictors of GHG effluxes at the water-air interface. Interestingly, sediment DOC had a significant promoting effect on GHG emission effluxes at the water-air interface. Especially, water pH had a positive impact on CO2 effluxes at the water-air interface in the treatment with submerged plants (Treatment 1), but negative in the treatment without submerged plants (Treatment 2, Treatment 3, Treatment 4, Treatment 5).
2023 Vol. 43 (10): 5403-5411 [Abstract] ( 145 ) [HTML 0KB] [ PDF 489KB] ( 1736 )
5412 Evaluation on the conservation efficiency of natural reserves for rare and endangered wild plants
ZHAO Xiao-jiong, WANG Jian, SU Jun-de
Nature reserves play an irreplaceable role in the in-situ conservation of biodiversity. Currently, quantitative assessment of the conservation efficiency of nature reserves for rare and endangered species is one of the hot research topics. In the present study, Gansu Province, a biodiversity hotspot, was chosen as the research area. Based on remote sensing and GIS technology, the distribution of the main rare and endangered wild plants and the information of resources in their habitats were systematicly collected. The habitat suitability distribution pattern of 29 species of rare and endangered plants was then simulated by using the species habitat suitability evaluation model, and the biodiversity conservation value of the main rare and endangered plants was calculated by using the substitution cost method. Finally, the protection effect of the natural reserves on rare and endangered wild plants was evaluated from multiple perspectives by using indicators including the suitable habitat area of species, the importance of habitat, and the protection value of rare and endangered plants. The results indicate that:(1) The area of the suitable habitat was 72988.12km2, with few region having high suitable values. The five species of plants including Anisodamine, Rhizoma Bletillae, Plum Blossom, Artemisia selengensis, and Acer miaotai were widely distributed, accounting for 80.72% of the total suitable habitat distribution area. In addition, the distribution difference of suitable habitat between the northern and southern part of Gansu Province was obvious; (2) The protection value of rare and endangered wild plants was 267.474billion Yuan in Gansu Province. The high value areas are mainly concentrated in Longnan and Gannan in the south of Gansu Province, and the overall distribution trend of the protection value gradually decreases from the northeast to the southwest, with the highest value area located in the forest area in the south of Gansu Province, followed by the northern Qilian Mountain area, and the Chinese Loess Plateau; (3) The area of suitable habitats in nature reserves accounts for 33.56% of the distribution area of suitable habitats in Gansu Province. The area of region with an importance value of suitable habitats greater than 5 (high-value region) in nature reserves only accounts for 34.86% of the high-value areas of suitable habitats in Gansu Province. A large part of high-value regions are not included in the strict protection of nature reserves. The value of biodiversity conservation in the overlapping area of natural reserves and suitable habitats is 64.585billion Yuan, accounting for 24.15% of biodiversity conservation value in Gansu Province. Although the natural reserves can better represent the suitable habitats in Gansu Province to a certain extent, there is a mismatch between their spatial distribution and the suitable distribution range of rare and endangered wild plants and the high value regions for biodiversity conservation. The present study has important guiding significance for the optimization and adjustment of nature reserves and the formulation of biodiversity conservation strategies.
2023 Vol. 43 (10): 5412-5421 [Abstract] ( 178 ) [HTML 0KB] [ PDF 1178KB] ( 1754 )
5422 Effects of biochar and its dissolved fractions on microbial reduction of ferrihydrite
XIA Jin-xia, SUN Jin-tao, YU Rui, WANG Yi-chu, AN Wei-qi, JIN Jie, CAO Dan-dan
In this study, biochar (BC) was prepared from rice straw at different pyrolysis temperatures (300, 400, and 500℃), and was used for dissolved fractions (DBC) extraction. In this study, the effects of BC and DBC on the reduction of ferrihydrite by Geobacter sulphurreducens PCA were investigated by combining microbial reduction experiments and various characterization methods including Fourier transition infrared spectroscopy (FTIR), X-ray diffraction crystal diffraction (XRD), and Electron paramagnetic resonance (EPR). The results showed that the highest reduction rate of ferrihydrite was achieved after the addition of BC prepared at 400℃ (BC-400), which increased the rate of microbial dissimilatory iron reduction by 12 times. Containing the most quinone and carboxyl groups, BC-400 could function as an electron shuttle to promote electron transfer. BC could not serve as an electron donor to provide electrons directly to PCA or ferrihydrite. DBC increased the degree of long-term microbial reduction extent and initial reduction rate by more than 10 times and 2 times, respectively. DBC extracted from BC prepared at 500℃ served as an both electron shuttle and electron donor to promote the microbial reduction of ferrihydrite, but it cannot directly chemically reduce ferrihydrite.
2023 Vol. 43 (10): 5422-5432 [Abstract] ( 177 ) [HTML 0KB] [ PDF 1743KB] ( 1862 )
5433 Ecological risk assessment of heavy metals in sediments of Longyang Lake and Moshui Lake in Wuhan
ZHOU Feng, LI Peng, WENG Mao-zhi, XING Xin-li, LIU Li, ZHANG Ya, ZHU Xian-ting, LUO Hong
In order to assess the current status of the ecological environment of urban lake wetlands, the present study employs various methods, including mathematical statistics, ground accumulation index, and potential ecological risk index. These methods are used to evaluate the enrichment levels, spatial distributions, and ecological risks of nitrogen, phosphorus, and heavy metal elements in the surface sediments of Longyang Lake and Moshui Lake, located in Wuhan, China. The results indicate that the surface sediment samples from Longyang Lake have total nitrogen (TN) and total phosphorus (TP) contents ranging from 265.03to 729.68mg/kg and 888.64 to 1694.86mg/kg, respectively. On the other hand, Moshui Lake samples have TN and TP contents ranging from 306.14 to 857.27mg/kg and 671.48 to 2674.39mg/kg, respectively. Thus, Moshui Lake exhibits higher pollution levels compared to Longyang Lake. Moreover, when compared to typical lakes in other domestic cities, both Longyang Lake and Moshui Lake exhibit low TN and high TP contents in their sediments. The concentrations of As, Cd, Cr, Cu, Pb, and Zn in Longyang Lake are 14.27mg/kg, 0.58mg/kg, 59.20mg/kg, 55.61mg/kg, 33.20mg/kg, and 176.94mg/kg, respectively. In Moshui Lake, the concentrations of these elements are 19.26mg/kg, 0.62mg/kg, 85.53mg/kg, 53.67mg/kg, 41.69mg/kg, and 266.64mg/kg, respectively. Additionally, the average concentration of heavy metal elements in the surface sediments, except for Cr, exceeds the background levels of soil in Wuhan. Moreover, the Cd content in Longyang Lake and Moshui Lake are significantly higher than the background values, being 4.83 and 5.17times greater, respectively. Comparing the current conditions with those from 20 years ago, it is evident that the content of heavy metal elements (except Cd) in Moshui Lake's sediments has decreased. This suggests that efforts to clean the lake's mud have improved the sediment conditions, although pollution has not been completely eliminated. The accumulated index indicates that the Cd level in both lakes is in a roughly moderate polluted state, while Cu, Pb, Zn, and As are generally in a mildly polluted state, and Cr is in a clean state. The potential ecological risk index suggests that the overall potential ecological risk is at a low to medium level, but the Cd content in both lakes poses a moderate to severe risk. The study area's heavy metal elemental pollutants may be sourced from a combination of fluxes, including early industrial discharge, fishery farming, animal feces, and emissions from human domestic sewage.
2023 Vol. 43 (10): 5433-5443 [Abstract] ( 159 ) [HTML 0KB] [ PDF 1683KB] ( 1512 )
5444 Pollution characteristics and emission flux of per- and polyfluoroalkyl substances in Gongga Glacier
HUANG Yu, CHEN Zhao-hui, LI Yu-tao, ZHANG Hui, LIU Wei, FANG Shu-hong
Twenty one per- and polyfluoroalkyl substances (PFASs) in water samples collected from Hailuogou area of Gongga Mountain were analyzed by an ultra-performance liquid chromatography coupled with a tandem mass spectrometry (UPLC-MS/MS) to study the occurrence characteristics of PFASs in Gongga Glacier. The results showed that 11 PFASs were detected, with concentrations of 7.09~106ng/L(average 30.2ng/L). The main PFASs were perfluorobutanoic acid (PFBA, 131ng/L), perfluorooctanoic acid (PFOA, 37.2ng/L) and perfluorooctane sulfonate (PFOS, 17.1ng/L). The highest concentration occurred at Caohaizi area with an altitude of 2735m, with the total concentration of 106ng/L. There is no direct emission source here, and high concentrations of PFASs in rainfall indicate the sources from the dry and wet deposition of the atmosphere. The annual emission flux of PFASs in Hailuogou was 0.2197t/a, and PFOA displayed the highest emission flux (0.0762t/a), accounting for 34.71% of the total emission flux, followed by PFHpA (0.0317t/a) and PFBA (0.0285t/a) accounting for 14.43% and 12.96%, respectively. More attention should be paid to monitor PFASs in Hailuogou area to provide data for scientific management and control on PFASs.
2023 Vol. 43 (10): 5444-5452 [Abstract] ( 210 ) [HTML 0KB] [ PDF 851KB] ( 1967 )
5453 Spatiotemporal changes and trade-off analysis of ecosystem services in Ningxia Hui Autonomous Region
YANG Qiang-qiang, ZHANG Pian, QIU Xiao-cong, ZHAO Zeng-feng, ZHAO Rui-zhi, ZHOU Rui-juan
Based on the multi-source data such as land use, elevation and precipitation, this paper adopted methods such as InVEST model, PLUS model, correlation analysis and hotspot analysis, investigated the spatio-temporal characteristics of ecosystem services (water purification, soil conservation, carbon storage, and habitat quality) in Ningxia from 2000 to 2020 as well as their trade-off/synergies, and simulated ecosystem services in 2030. As shown by results, during the research period, land use types changed relatively greatly in the past decades, and human activities were the main driving factor. From 2000 to 2020, except for soil conservation services, water purification in Ningxia, carbon storage and habitat quality all presented a declining trend. According to correlation analysis, there was a synergistic effect between nitrogen export and soil conservation and carbon storage. In addition, there was a synergistic relationship between soil conservation and carbon storage, as well as a trade-off between habitat quality and nitrogen export and carbon storage. As shown by hotspot analysis, hot spots overlapping areas between water purification services and habitat quality were relatively high (average value of 6.5%), but the proportion of regions that can simultaneously provide various ecosystem services per unit area was relatively low and showed a declining trend. In addition to soil conservation services, the ecological protection scenario was more favorable to improve ecosystem function. Research results, which highlight the importance of ecological protection in land use management, can provide a basic reference for the optimization of regional land patterns and the effective allocation of resources.
2023 Vol. 43 (10): 5453-5465 [Abstract] ( 139 ) [HTML 0KB] [ PDF 4636KB] ( 1816 )
5466 Impact of landscape ecological risk change on flood in Lianshui watershed
SHENG Fei, LIU Shi-yu, DAI Yu-dian, GUAN Xing-zhong, LU Jing-yuan
The Lianshui watershed located in southern Jiangxi province was selected to examine changes in landscape pattern from 1995 to 2020, as well as the temporal and spatial variation characteristics of landscape ecological risk at both the whole watershed and sub-watershed scales. The HEC-HMS model was utilized to simulate the flood process of 120 rainstorm events in the studied watershed under different landscape pattern scenarios for 1995 and 2005. Furthermore, Spearman correlation analysis was conducted to investigate the influence of changes in landscape ecological risk on floods. The results revealed that forested land constituted the primary landscape type with the highest area proportion within the watershed. However, other woodland experienced significant changes between 1995 and 2005, while construction land exhibited a substantial increase from 2005 to 2020. At the whole watershed scale, average values of the landscape ecological risk index were found to be 0.0621 (in 1995), 0.0543 (in 2005), and 0.0532 (in 2020), indicating a decreasing trend in overall landscape ecological risk, transforming from high level to low level. At a more detailed sub-watershed scale analysis, it was observed that certain sub-watersheds such as W170, W180, W210, and W260 displayed a downward trend regarding their respective levels of landscape ecological risk over time. However, W140 and W230 exhibited a dynamic change pattern characterized by an initial decrease followed by an increase. Finally, W220 demonstrated an opposite trend with an initial increase followed by a subsequent decrease. The period between 1995 and 2005 witnessed dramatic shifts in terms of landscape ecological risk levels. The average correlation coefficient values depicted in the box plots between the rate of change in the landscape ecological risk index and the rate of change in peak flow and total flood volume were 0.616and 0.603, respectively. The fluctuations observed in the landscape ecological risk within the watershed had a significant impact on flooding, with a greater influence on peak flow compared to total flood volume.
2023 Vol. 43 (10): 5466-5474 [Abstract] ( 161 ) [HTML 0KB] [ PDF 2445KB] ( 1692 )
5475 Spatial and temporal evolution of ecological risk in FAST Radio Quiet Zone based on landscape pattern
XIN Liang, SU Wei-ci
Based on the land use data in 2000, 2010 and 2020, the evaluation model was constructed by using the landscape disturbance index and landscape vulnerability index to analyze the change characteristics of landscape pattern and ecological risk in the region in the past two decades, so as to reveal the impacts of the completion of the FAST project on the ecological environment of different circles in this region. The purpose was to provide some reference for the future ecological protection and risk prevention in this region. The results showed that:woodland, grassland and cultivated land were the dominant landscape types in FAST Radio Quiet Zone. From 2000 to 2010, the landscape changes were mainly from grassland and cultivated land to woodland, and human activities were relatively weak. From 2010 to 2020, the construction land increased rapidly, the comprehensive dynamic attitudes of the three circles increased, and the landscape pattern changed gradually active but still at a low controllable level. The study area was mainly composed of low ecological risk area, lower ecological risk area and medium ecological risk area. The ecological risk was low in both the core area and the middle area but had an increasing trend under the influence of the FAST project, while the risk change in the remote area showed a spindle shape of "decreasing at the poles and increasing in the middle". The ecological risk in the study area showed a spatial positive correlation and the correlation became more and more significant. The distribution characteristics were mainly "high-high" aggregation and "low-low" aggregation.
2023 Vol. 43 (10): 5475-5487 [Abstract] ( 161 ) [HTML 0KB] [ PDF 3118KB] ( 1563 )
5488 Filtration performance of microstructure pleated filter media based on Voronoi-Random algorithm
XU Yan, CHENG Si-min, SUN Yi, CAO Bo-wen, QIAN Fu-ping, LU Jin-li, HAN Yun-long
When using numerical simulation to study the filtration performance of pleated fiber filter media, in order to overcome the shortcomings of discontinuous layers and regular distribution of porous fibers, a pleated fiber filter media model was established based on Voronoi-Random algorithm, and its solid volume fraction (SVF) was changed by encrypting or reducing the number of fibers. Two collision models "Caught on first touch" and "Hamker" were used to simulate the gas-solid two-phase flow of pleated fiber filter media. The results show that the numerical values of pressure loss and filtration efficiency were in good agreement with those calculated by empirical correlation, and the error was within 15%; Comparing the filtration efficiency obtained by two collision models of "Caught on first touch" and "Hamker" with the calculated value of empirical correlation, it was concluded that the filtering efficiency obtained by "Hamker" collision model accords with the reality; The particles deposited on the filter media were not completely captured by fibers, but most of them were captured by dendritic structures formed; The pressure drop and deposition per unit area increased exponentially with the increase of filtration time.
2023 Vol. 43 (10): 5488-5497 [Abstract] ( 144 ) [HTML 0KB] [ PDF 1264KB] ( 1288 )
5498 Homeostasis of Setaria viridis (L.) Beauv. in Yantai coastal zone alleviated P limitation
ZHONG Xiao-ying, REN Yi-wei, YI Hua-peng, ZHU He, GAO Meng
In order to explore the nutrient utilization and environmental adaptation strategies of Setaria viridis (L.) Beauv. on different coastal gradients, this paper analyzed the nutrient content of Setaria viridis leaves and soil under the sandy coastal shelter forest in Yantai, and discussed the relationship between leaf stoichiometry characteristics and endostabilizing characteristics and soil. The results showed that there was a certain response in the leaf and soil nutrient content and stoichiometric characteristics of Setaria viridis on different coastal gradients. The soil P content in the study area was extremely low, and more specifically the leaves of Setaria viridis grass P-N:P(leaf nitrogen-phosphorus ratio)>16. The growth and development of Setaria viridis were more limited by the P element. Moreover, P-C (leaf organic carbon), P-P (leaf total phosphorus), P-C:N (leaf carbon-nitrogen ratio), P-C:P (leaf carbon-phosphorus ratio) and P-N:P(the leaf nitrogen-phosphorus ratio) were all in absolute steady state. 1/H(P-N) (the internal stability coefficient of leaf total nitrogen) was 0.26, which belonged to the weak steady state type, but N:P was more stable than N and P elements. It is concluded that Setaria viridis regulate its nutrients in a certain proportion during the growth process. In the study area, Setaria viridis was mainly limited by the P element, but the overall internal stability was high indicating that Setaria viridis was highly adaptable in the coastal environment. It could maintain the dynamic balance of stoichiometry in vivo in a changeable environment, and alleviate the influence of P restriction in coastal areas with a low growing rate.
2023 Vol. 43 (10): 5498-5507 [Abstract] ( 183 ) [HTML 0KB] [ PDF 1507KB] ( 1739 )
5508 Spatio-temporal dynamics of territorial ecosystem carbon storage under different land use scenarios in Siping City
ZOU Tao-hong, CHEN Peng, LIU Jia-fu, DU Hui-shi
Based on the land use data of Siping City from 1990 to 2020, the Geo-FLUS model was employed to simulate the spatial patterns of land use for 2030 across three different scenarios:natural development, cultivated land protection and ecological priority. Additionally, the InVEST model was coupled to quantitively analyze the spatial and temporal variation of carbon storage from 1990 to 2020, as well the impact of land use change on carbon storage under different scenarios. The results showed that:(1) From 1990 to 2020, cultivated land and forest land in Siping City decreased by 951.55km2 and 357.54km2, respectively, with the sharpest decline between 1990 to 2000. Conversely, the grassland and built-up land use exhilited an increasing trend, expanding by 702.97km2 and 587.64km2, respectively. Under the ecological priority scenario in 2030, the forest land use was projected to expand, while the cultivated land would gradually increase. Cultivated land protection scenario ensured cultivated land availability but led to reductions in forest land and grassland. Built-up land use expanded across all three scenarios, most notably under natural development scenario. (2) Ecosystem carbon storage and average density in Siping City showed a continuous decline tendency from 1990 to 2020, with the steepest drop between 1990 and 2000. This decline was mainly due to decreased cultivated land and increased built-up land during that period. (3) Higher carbon storage value were observed in the eastern Yitong Manchu Automous and Tiedong area, characterized by forest land. Total carbon storage expressed a declining trend over the study period, decreasing greatly by about 0.703×107tons between 1990 and 2000. (4) Carbon storage and average carbon density in 2030 exhibited distinct trends across the three different scenarios. Ecological priority scenario led to an effective increase in both metrics for terrestrial ecosystem. Conversely natural development and cultivated land protection scenario yields declines, though the reduction under the cultivated land protection scenario was significantly lower than that under natural development scenario. Therefore, prioritizing ecological priority scenario in future land resource planning can ensure cultivated land resources, optimize land use structure, cultivated land quality, and amplify ecosystem carbon sequestration.
2023 Vol. 43 (10): 5508-5518 [Abstract] ( 198 ) [HTML 0KB] [ PDF 3010KB] ( 1422 )
5519 Spatio-temporal changes of NDVI and its response to climate in China from 2001 to 2021
SUN Rui, ZHANG Fang-min, WENG Sheng-heng, LIU Qian
Based on the MODIS MOD13A3 dataset and climate data to analyze the spatio-temporal variations of NDVI in the nine major basins in China from 2001 to 2021 by statistical methods of linear regression, Theil-Sen trend and Mann-Kendall significance test. Further, the responses of NDVI to precipitation, air temperature, solar radiation and saturated water pressure difference in the nine major basins in China were investigated by using Geodetector analysis. The results showed that NDVI showed a significant upward trend (P<0.05) both in China and the nine major river basins from 2001 to 2021. The change rate of NDVI in the Yangtze River Basin, the Pearl River Basin, the Southeast River Basin and the Huaihe River Basin was the largest in winter, the Haihe River Basin in spring, the Southwest River Basin in autumn, and the other river basins in summer. From the perspective of land use change types, the NDVI change rate was ranking in the order of non-urbanized area (0.0026/a) > non-type change area (0.0021/a) > urbanized area (0.0013/a). Moreover, the NDVI of the urbanization areas was degraded in the Southeast River Basin and the Southwest River Basin. Spatially, the change rate of NDVI decreased from east to west and from south to north. The areas with stable vegetation growth accounted for 26.43% of the total area of China, mainly concentrated in the Inland River Basin and the northwest of the Southwest River Basin. The areas with vegetation improvement accounted for 70.31%, mainly distributed in the non-urbanized area of the nine major river basins. The area with vegetation degradation accounted for 3.25%, which was concentrated in the north of the Inland River Basin, the east of the Southwest River Basin, the west of Yangtze River Basin and the coastal basins in the east China. The factor detection results showed precipitation was the main factor controlling the spatial distribution of NDVI across China, followed by air temperature, saturated water pressure difference and solar radiation. In most of the nine river basins, precipitation was still the main determinant, but the saturated water pressure difference was the main determinant in the Yangtze River Basin, the Pearl River Basin and the Huaihe River Basin. In the past 21years, the influence of climatic factors on NDVI in the Yangtze River Basin, the Songliao River Basin, the Yellow River Basin and the Southwest River Basin has mostly increased, while the influence of climatic factors in other river basins has basically decreased.
2023 Vol. 43 (10): 5519-5528 [Abstract] ( 250 ) [HTML 0KB] [ PDF 2218KB] ( 1411 )
5529 Transformation study of aspartic acid in under metalimnetic oxygen minimum region of reservoirs: regularity and mechanism
ZHAO Na, CAO Rui-hua, HUANG Ting-lin, WEN Gang
Aspartic acid (Asp), a typical precursor of containing nitrogen disinfection byproducts, was selected as the research object to investigate the transformation of Asp and the variation of disinfection byproduct formation potential (DBPFPs) under MOM condition with different concentration of dissolved oxygen (DO) and pressure. The main environmental factors and potential mechanism of Asp transformation was further clarified. The results showed that the dissolved organic carbon (DOC), dissolved organic nitrogen (DON) and T-DBPFPs of Asp water samples decreased gradually with the increase of reaction time under different MOM condition. Compared with anaerobic condition (atmospheric pressure), a lower decrease was occurred in DOC and DON (16.40%~25.50%) and T-DBPFPs (30.34%~59.81%) under MOM condition with 0.30MPa pressure and 0.50mg/L DO, which was related to more soluble biometabolites (C2 component) were produced during microbial metabolism under such condition. In addition, the decrease in DOC, DON, and T-DBPFPs (DOC and DON:70.27%~95.00%; T-DBPFPs:61.50%~98.88%) under MOM condition with 0.30MPa pressure and 3.00~7.00mg/L DO aerobic condition was higher than those under MOM condition with 0.50mg/L DO at 3th day of reaction. Combining the above discussion, it can be concluded that the MOM condition with pressure and lower DO concentration was not conducive to the transformation of Asp water samples. The redundancy analysis showed that DO concentration was the main water environmental factor affecting Asp transformation under MOM condition. Bacterial community analysis further confirmed that the diversity of bacterial community decreased significantly under MOM condition with lower DO concentration, affecting the metabolites and transformation degree of bacteria to Asp water samples and the reduction of DBPFPs. Therefore, it is of great significance to investigate the transformation and its mechanism of Asp water sample under MOM condition for ensuring drinking water safety.
2023 Vol. 43 (10): 5529-5542 [Abstract] ( 196 ) [HTML 0KB] [ PDF 1327KB] ( 2919 )
Environmental Microbiology
5543 Establishment and assessment of a competitive direct enzyme-linked immunosorbent assay (cdELISA) for the determination of cylindrospermopsin
YANG Dan, LIU Jin-ping, LAI Shu-yan, XIAO Li-juan, LEI La-mei
Cylindrospermopsins(CYN) has been widely concerned in the world for its high toxicity to humans and animals. The establishment of a rapid detection method can provide an effective tool for the risk assessment of CYN. Based on the monoclonal antibody N8 against CYN prepared, a direct competitive ELISA has been developed. After optimization of the dilution of HRP-CYN conjugate and N8 monoclonal antibody, the newly developed ELISA exhibited a typical sigmoidal response for CYN at concentrations of 0~200ng/mL, with a wide quantitative range between 0.1 and 10ng/mL by using logit-log method for fitting the curve. The detection limit of the method was calculated to be 0.069ng/mL, which is well below guideline value of 0.7ng/mL CYN recommended by WHO. Recoveries ranging from 80.44% to 125.4% and 52.97% to 155.19% were observed upon analyzing CYN-spiked water samples and Chlorellae diluent, respectively. Moreover, CYN concentrations obtained from our cdELISA method through testing different samples was highly consistent with the Beacon ELISA kit. It was found that CYN can be detected year around in Dashahe reservoir but never beyond the guideline value of 0.7ng/mL. Therefore, the developed ELISA will achieve the rapid detection of CYN in water samples and algae samples and may provide a reliable technical tool for drinking water safety.
2023 Vol. 43 (10): 5543-5549 [Abstract] ( 192 ) [HTML 0KB] [ PDF 577KB] ( 1678 )
5550 Structure and assembly mechanism of bacterial communities in deep soil contaminated by chlorinated hydrocarbons
FAN Yan-ling, GOU Ya-ling, WANG Hong-qi, LIU Zeng-jun, XU He-feng, YANG Shuo, LIANG Jing
To study the structural characteristics and assembly mechanism of bacterial community in chlorinated hydrocarbons contaminated soil, unsaturated-zone soil within 2~10m was collected from different contaminated areas. Based on high-throughput sequencing technology, the bacterial community was analyzed and the main drivers, environmental influencing factors and assembly mechanism of the community structure changes were revealed. The results showed that the main driver of bacterial community structure change in the lightly polluted area was soil type. The β-diversity mainly influenced by species replacement with a contribution of 53.9%, and community composition significantly correlated with water-soluble sulfate(R=0.61, P=0.0002) and total organic carbon content(R=0.42, P=0.0005). Furthermore, the main driver of bacterial community structure change in the heavily polluted area was the degree of pollution. The β-diversity mainly influenced by the differences in abundance with a contribution of 52.9%, community composition was significantly correlated with trichloroethylene(R=0.17, P=0.0425), chloroform (R=0.22, P=0.0375), water-soluble sulfate (R=0.36, P=0.0074), total organic carbon (R=0.29, P=0.0168), and total nitrogen content (R=0.20, P=0.0130). Chlorinated hydrocarbons stress narrowed the niche width and reduced the niche overlap index of most species except adaptive ones, and led to an increase in the abundance of Proteobacteria, while that of Actinobacteriota, Firmicutes, and Chloroflexi decreased. In the soil with low pollutant concentration, the bacterial community assembly was dominated by random process, with a contribution of 65.6%. In the soil with high pollutant concentration, the random process decreased to 27.7%, and the assembly was dominated by deterministic process.
2023 Vol. 43 (10): 5550-5561 [Abstract] ( 140 ) [HTML 0KB] [ PDF 1449KB] ( 1907 )
Emerging Contaminants and Environmental Toxicology
5562 Unravelling the influencing mechanism of polystyrene microplastics on the algal-bacterial granular sludge systems
XU Hang, ZHANG Bing, SHI Wen-xin
The algal-bacterial granular sludge (ABGS) system was established by inoculating the mature aerobic granular sludge (AGS) and targeted algae (Chlorella). The effects of polystyrene microplastics (PS-MPs) on the ABGS system was investigated in this study. Results indicated that low concentrations of PS-MPs (1mg/L) had no significant effect on the biomass content, algal growth, sludge settling performance and pollutant removal efficiency of ABGS. Compared with the control group, the biomass content, algal growth and sludge settling performance of ABGS were inhibited under the pressure of high concentrations of PS-MPs (10mg/L and 100mg/L). To be specific, the ratio of chlorophyll α to MLSS decreased by 0.19mg/g, and the average particle size of sludge decreased by 200μm. Meanwhile, the granular sludge structure gradually became loosely and disintegrated. The removal efficiencies of chemical oxygen demand (COD), nitrogen, phosphorus of ABGS system were significantly decreased by 4.83%, 5.06% and 4.11%, respectively. In addition, PS-MPs inhibited the secretion of extracellular polymer substance (EPS) of ABGS, especially for the tryptophan and aromatic proteins. In terms of the microbial community structure, PS-MPs improved the diversity of bacterial species in the ABGS system, but inhibited the growth of functional bacteria (such as Verrucomicrobiota, Cyanobacteria and Chloroflexi), which were not conducive to maintaining the long-term stability of ABGS system.
2023 Vol. 43 (10): 5562-5573 [Abstract] ( 154 ) [HTML 0KB] [ PDF 2932KB] ( 2446 )
5574 Characterization of pyrene's impact on the soil functional microorganisms for nitrogen transformation
HU Qin, ZHANG Li-lan, YI Mei-ling, YANG Rui
An aerobic degradation microenvironment was constructed to analyze the effects of pyrene (12.09mg/kg) at ambient concentration on soil enzyme activities, the whole process of nitrogen transformation and related functional microorganisms. The results showed that pyrene only significantly increased urease activity on the first day of degradation, but promoted the dehydrogenase activity at both the early and late phases of degradation. The analysis of the bacterial community structure revealed that the variation of the relative abundance of ammonia-oxidizing bacteria (Nitrososphaeraceae) promoted pyrene-mediated aerobic ammonia oxidation and nitrification in the early stages of treatment and inhibited that in the late stages. In contrast, the effects of nitrogen-fixing bacteria (Bradyrhizobium, Mesorhizobium and Ensifer), urea-degrading bacteria (Roseomonas), and nitrate-reducing bacteria (Opitutus) were opposite. The quantitative analysis of functional genes showed that, despite pyrene's repressive effect on the nitrogen-fixing gene nifH at the start of the culture, the abundance of nifH showed an increasing trend, which was not consistent to the anticipated changes in microbial community structure and associated functions. Compared with changes in key enzyme activities and genes encoding the processes of ammonia oxidation and denitrification, pyrene did not significantly boost ammonia oxidation in the early stages of incubation, t severely hampered ammonia oxidation and denitrification after 15days, significantly inhibited the ammonia oxidation process. In this study, how pyrene influenced the microbial nitrogen transformation process in soil was reported, fundamental data on understanding the environmental hazard of pyrene were provided.
2023 Vol. 43 (10): 5574-5582 [Abstract] ( 152 ) [HTML 0KB] [ PDF 1441KB] ( 1855 )
5583 Water microplastics pollution and distribution characteristics in the upper Wuding River Basin
WANG Yu-dan, GUI Wei-zhen, SHAO Tian-jie, ZHU Ya-di, WANG Yan-hua, WANG Rui-yuan, LI Dong-ze
In this study, We investigated the abundance and distribution of microplastics in the upper main stream of the Wuding River, a first-order tributary of the Yellow River, and the tributaries of the Nalin River, the Hailiu Rabbit River, the Yuxi River and the Lu River. The results showed that:The average abundance of microplastics in the water bodies of the upper Wuding River Basin was 15.58n/L, ranging from 2.5 to 35.63n/L. Microplastic types were abundant, with the percentages of PEG (62.96%), PE (6.17%), PPS (3.09%), 4-vinylbiphenyl (2.78%), PCTG (2.47%), PS (2.16%), PTFE (2.16%), PPSU (1.85%), PMMA (1.54%), others (14.81%). More than 96% of the microplastics were less than 1mm, which was very easy to enter the enrichment of organisms. The shape is dominated by fragments, followed by films and granules; most of them were transparent or brown, and other colors accounted for about 25%. Based on the source-specific classification system of microplastics, it was initially determined that microplastics mainly originated from agricultural mulch film and personal toiletries. The results indicate that the overall risk of microplastics in water bodies in the upper watershed of the Wuding River was at a mild pollution level. The abuse of toxic and harmful plastics was of particular concern. The study of microplastics in the upper Wuding River basin, which is located in the windy beach area in the southeastern part of the Mawusu Desert, on the one hand reveals the current status and potential pollution risk of microplastics in the windy beach area; on the other hand, it provides a typical case of scientific understanding of the impact of urban development and agricultural production on the water environment in the desert area from the perspective of microplastics.
2023 Vol. 43 (10): 5583-5590 [Abstract] ( 283 ) [HTML 0KB] [ PDF 1020KB] ( 2288 )
5591 Effects of triazine herbicide prometryn on marine phytoplankton communities—Based on analysis of microalgae population dynamics, interspecific competition and photosynthetic capacity
LI Yi-lei, LIANG Wei, ZHAO Zi-ang, RU Shao-guo, ZHANG Xiao-na
In this study, effects of prometryn on the population dynamics, photosynthetic capacity, and interspecific competition of three marine microalgae species, including Phaeodactylum tricornutum, Chlorella pacifica, and Isochrysis galbana, were evaluated based on the monoculture experiment and the co-culture experiment with two microalgaes (cell density ratio1:1). The results showed that the 96h-EC50 values of prometryn for P. tricornutum, C. pacifica, and I. galbana were 7.65, 16.67, and 4.11 μg/L, respectively; and the toxicity from high to low was as follows:I. galbana > P. tricornutum > C. pacifica. Prometryn exposure significantly inhibited the photosynthesis of these three microalgaes and thereby reduced their population growth. In addition, prometryn treatment also weakened the competitive inhibition of P. tricornutum by C. pacifica in the co-culture group and during the cocultivation of C. pacifica and I. galbana exposed to environmental concentrations (0.5 and 5μg/L) of prometryn for 12 days, an extinction of the sensitive species I. galbana was observed, indicating an interspecific interaction more favorable to diatoms. Overall, this study would provide more theoretical support for assessing the marine ecological risk of the triazine herbicide prometryn.
2023 Vol. 43 (10): 5591-5603 [Abstract] ( 155 ) [HTML 0KB] [ PDF 916KB] ( 1646 )
Carbon Emission Control
5604 A neural network partitioning method for carbon emission estimation based on spatial-temporal clustering of atmospheric CO2 concentration
ZHANG Shao-qing, LEI Li-ping, SONG Hao, GUO Kai-yuan, JI Zhang-hui, SHENG Meng-ya
Aiming at the non-normal distribution of anthropogenic carbon emissions due to the large spatial difference of magnitude, a neural network estimation model for anthropogenic carbon emissions was proposed in this study based on the clustering of spatial-temporal variation characteristics of satellite XCO2. Using the spatial and temporal variations of satellite XCO2 (2010~2021), which are strongly correlated with anthropogenic carbon emissions, for clustering and partitioning, and utilizing satellite-observed SIF, nighttime lighting, as well as population density and anthropogenic emission inventory(EDGAR) as training data, neural network models for Carbon emission estimation were built respectively in each cluster region, and the anthropogenic carbon emissions of the study area were estimated for the year 2021. Cross-verification results with EDGAR show that compared with the unified modeling method based on the data of the whole study area, the estimation result of the partition modeling proposed in this study increased the correlation coefficient (R2) from 0.43 to 0.82, with more reasonable spatial distribution, and the mean deviation decreased from 0.039Mt CO2 to 0.018Mt CO2. The study shows that the estimation of anthropogenic carbon emissions using neural network training with multi-source data can provide data support for the characterization of regional carbon emissions and the assessment of uncertainty in emission inventories.
2023 Vol. 43 (10): 5604-5613 [Abstract] ( 187 ) [HTML 0KB] [ PDF 2532KB] ( 2141 )
5614 Estimation of both air pollutants and carbon emission inventories from civil aircrafts in China
ZHANG Tian, TIAN Yong
Based on the take-off and landing data of Chinese civil aviation aircrafts from 2019 to 2021, the aircraft engine emission factor database of International Civil Aviation Organization (ICAO), and Aircraft Data Base database (BADA) of EUROCONTROL, the high-resolution air pollutants and carbon emission inventories during the entire flight process of Chinese civil aviation aircrafts from 2019 to 2021 were developed from bottom to up. Next, their spatial distribution characteristics in different geographical regions in China were analyzed, where the emerging impacts of the novel coronavirus infection from 2019 to 2021 was further explored. According to the results, the total HC, CO, NOx, and CO2 emissions of China's civil aviation aircrafts in 2019 were 0.74, 6.38, 33.98, and 7785.05million tons, respectively. Also, during the take-off and landing (LTO) cycle stage, the HC, CO, NOx, and CO2 emissions made up 37.84%, 55.02%, 18.83%, and 18.31% of the total emissions, respectively. Specially, Eastern China region had the highest aviation carbon emissions, accounting for 27.20% of the whole country's emissions. Last, the total air pollution emissions decreased from 2019 to 2021, where the CO2 emissions in 2020 and 2021 were reduced by 17.26% and 10.38%, respectively.
2023 Vol. 43 (10): 5614-5623 [Abstract] ( 249 ) [HTML 0KB] [ PDF 2701KB] ( 2313 )
Environmental Impact Assessment and Management
5624 Study on the cost-benefit analysis of new energy vehicles for road freight transportation based on scenario simulation
LIU Wei, WAN Yan-ming, CHEN Si-yuan, LIU Chang, LIU Qi, ZHANG Yan, WANG Ge
To achieve the carbon peaking and carbon neutrality goals, China's road freight sector needs to reduce emissions by developing electric and hydrogen vehicles to replace traditional fuel vehicles. In this paper, a life-cycle benefit analysis model of freight vehicles considering scenario heterogeneity was constructed to compare the life-cycle costs and revenues of oil, electric and hydrogen vehicles under different route scenarios, taking 25t tractors and 18t railcars as examples. The results showed that hydrogen vehicles were more suitable for long-distance heavy freight scenarios with high shipping prices and cold climates, while electric freight models were more suitable for low shipping prices, short-distance, light-load, and warm climate scenarios. Moreover, hydrogen vehicles can outperform electric vehicles in 25-ton heavy freight scenarios by 2030, which can be the key layout direction for hydrogen vehicles. In the short and medium term, policies such as hydrogen price subsidies and carbon taxes cannot achieve spontaneous substitution of new energy vehicles for fuel vehicles in the freight sector, and additional policy support will be needed.
2023 Vol. 43 (10): 5624-5632 [Abstract] ( 253 ) [HTML 0KB] [ PDF 1163KB] ( 2035 )
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