CHINA ENVIRONMENTAL SCIENCECE
 
 
CHINA ENVIRONMENTAL SCIENCECE
　　　　　　　　    More    
Online Submission
Manuscript Tracking
Peer Review
Editor Work
Office Work
Editor-in-chief
Forthcoming Articles
Current Issue
Archive
Advanced Search
Read Articles
Download Articles
Instruction
Template
Copyright Agreement
More   
  Current Issue
 
2023 Vol.43 Issue.11,Published 2023-11-20
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
5633 Attribution and source apportionment of a severe PM2.5 episode in winter 2021 over the Sichuan Basin
YANG Tong, YANG Xian-yu, RUAN Wen-xin, Lü Ya-qiong, HU Qin, CAO Bang-jun, BEN Bing-zheng, WU Kai
In this study, the Weather Research and Forecasting (WRF)-Community Multiscale Air Quality (CMAQ) model with ISAM module was adopted to simulate a highly polluted PM2.5 episode across the Sichuan Basin between November 11and November 20 in 2021. In combination with ground-level meteorological observations and air quality monitoring data, the formation mechanism of this episode and sources of PM2.5 were elucidated. The results show that the variations of meteorological parameters and air pollutants concentrations were well captured by the WRF-CMAQ model. This PM2.5 episode was mainly affected by local emissions and unfavorable meteorological conditions featured by low wind speeds and high relative humidity, resulting in the accumulation of PM2.5 in the Chengdu Plain, which progressively reached its peak in a short period. The peak daily average PM2.5 concentration in multiple cities exceeded 150μg/m3. Further analysis performed by ISAM indicates that local anthropogenic emissions were the dominant source of PM2.5 in cities within the Sichuan Basin, with a contribution higher than 50% depicted in Chengdu, Chongqing, Dazhou, and Guangyuan cities. Regional transport from nearby regions also played an important role in elevating PM2.5 levels.
2023 Vol. 43 (11): 5633-5644 [Abstract] ( 407 ) [HTML 1KB] [ PDF 10551KB] ( 1397 )
5645 Monitoring and driving factors analysis of CO2 concentration in China's mainland based on TanSat
LI Kai-xuan, YANG Li-ping, ZHANG Jing, REN Jie, WANG Yu
Based on XCO2, the column-averaged dry-air mole fraction of CO2, observed by TanSat from March 2017 to March 2018, the accuracy and reliability of this dataset were comprehensively verified and validated against NASA's OCO-2 satellite observations and CT and TCCON ground measurements in China's mainland. XCO2 characteristics in five main regions were analyzed, and driving effects of natural and socioeconomic factors on atmospheric CO2 concentration were investigated by using Pearson correlation analysis and Geodetector method. The results demonstrate a good consistency between TanSat and OCO-2 observations only with a minor difference between (-3~3)×10-6. In general, XCO2 concentration fluctuates regularly with seasons. In summer obvious regional distinctions were detected. XCO2 concentration in south China was at a higher level and greater than 403×10-6 due to intense human influence. Compared with other regions, in north China, a lower average XCO2 concentration (<401×10-6) was observed due to intense vegetation photosynthesis herein. Whereas XCO2 trend in west China was relatively flat. NDVI is the major natural factor affecting XCO2 concentration and presents a significant linear negative correlation with TanSat observations (r=-0.658, P<0.05). While fossil fuel burning had the strongest explanatory power for XCO2 spatial heterogeneity, and its interaction with various natural factors had much greater effect than each single factor. However, interaction between fossil fuel burning and rainfall would be the most influential one with a q value of 0.495.
2023 Vol. 43 (11): 5645-5654 [Abstract] ( 163 ) [HTML 1KB] [ PDF 1081KB] ( 1989 )
5655 A Study of Mn/Zr modification for NH3-SCR denitration mechanism of rare earth tailings
JIAO Kun-ling, JIAO Xiao-yun, LIU Jia-jie, LI Na, HOU Li-min, WU Wen-fei
Mn and Mn/Zr modified rare earth tailings-based NH3-SCR catalysts were prepared using the sol-gel method. The catalysts were characterized using a catalyst activity evaluation system, along with H2-TPR, NH3-TPD, XRD, and DRIFT techniques, to investigate the denitration process and reaction mechanism. The results showed that the denitration activity of the Mn and Mn/Zr modified rare earth tailings catalysts was significantly enhanced, with a denitration activity of 96% achieved at 200℃ for the 6%Mn1%Zr/rare earth tailings catalyst. The modified catalysts exhibited increased oxygen vacancies and acidic sites on the surface, as well as a higher adsorption capacity. The increase in reducible surface area of the catalysts contributed to the improvement of their redox performances. The reaction between NH4+ and gaseous NO2 on the acidic sites of the catalysts followed the E-R mechanism, while the reactions between NH4+ and monodentate and bidentate nitrate species followed the L-H mechanism.
2023 Vol. 43 (11): 5655-5662 [Abstract] ( 152 ) [HTML 1KB] [ PDF 856KB] ( 1138 )
5663 The ecological risks and sources of rare earth elements in the dustfall in typical cities of West China Strait-Based on neodymium isotope tracing combined with MixSIAR model
LI Yi-hong, YU Rui-lian, ZHANG Rui-qi, HU Gong-ren, YAN Yan
Rare earth elements as a kind of emerging contaminants (ECs) began to be widely concerned by scholars. In order to investigate the ecological risk and source contribution of rare earth elements in atmospheric dust in typical cities on the west coast of the China Straits, 15 sampling sites were set up in different functional areas of Quanzhou City to collect and analyze atmospheric dust samples and main potential pollution sources. The potential ecological risk index was used to evaluate the risk of rare earth elements, and the Nd isotope MixSIAR model was used for qualitative analysis and quantitative calculation. On the whole, the potential ecological risk index of rare earth elements in the dustfall in typical cities on the west coast of the Taiwan Strait was at low risk level. While Lu element was at medium risk at some sampling points, and the potential risk index of individual sampling points in industrial areas, commercial areas and heavy traffic areas was relatively high. The Plot of εNd(0) vs Eu/Eu* and εNd(0) vs ΣREEs show that rare earth elements in atmospheric dust samples were greatly affected by natural sources and local anthropogenic emissions such as gasoline exhaust dust, coal burning dust and cement dust. The relative contribution rate of each potential source was calculated by using the (143Nd/144Nd) MixSIAR model. The influence of rare earth elements in atmospheric dusfall in Quanzhou City was greatly influenced by the background soil(24.0%~40.9%), followed by gasoline exhaust dust (20.7%~33.3%) and coal burning dust (21.1%~29.0%). The impact of cement dust (13.7%~20.0%) was relatively low.
2023 Vol. 43 (11): 5663-5670 [Abstract] ( 133 ) [HTML 1KB] [ PDF 1524KB] ( 1572 )
5671 A Study on distribution pattern and influencing factors of CO2 flux in global reservoirs
OUYANG Chang-yue, QIN Yu, FANG Peng, LIANG Yue
This study explored the distribution pattern, spatial changes and influencing factors of CO2 flux in reservoirs from a global perspective, based on 277 sets of CO2 flux emission data from 234reservoirs around the world. The study showed that CO2 fluxes in tropical reservoirs were significantly higher than in other climates, and those in French Guiana and Brazil were significantly higher than in other countries. The CO2 fluxes of global reservoirs were significantly correlated with reservoir age, latitude and primary net productivity (NPP0) (P<0.001). With the increase of age and latitude, the CO2 flux dramatically decreased exponentially, and then the decline rate slowed down. No significant correlations were observed between water temperature, chlorophyll-a (Chl-a), dissolved organic carbon (DOC), total phosphorus and CO2 fluxes in global reservoirs. The CO2 fluxes in the young reservoir were 2.16 and 3.077 times of those in the middle and old reservoirs respectively, while in low latitudes was 2.042 and 3.91 times that in middle and high latitudes. The importance of factors on CO2 fluxes in global reservoirs was in the order of latitude > reservoir age >NPP0>Chl-a >DOC. On a global scale, the importance of global indicators such as geographical location, reservoir age and NPP0were much higher than that of carbon content and eutrophication in individual reservoirs. In future hydropower development, location of new reservoirs should be considered as much as possible to minimize carbon dioxide emissions, especially in tropical regions.
2023 Vol. 43 (11): 5671-5677 [Abstract] ( 171 ) [HTML 1KB] [ PDF 1691KB] ( 2049 )
5678 Spatial and temporal distribution of sulfur dioxide and main emission sources in China
WEI Ye-xiang, ZHANG Xiao-yu, ZHANG Hong
With the rapid development of urbanization and economy, China has become the world's third largest emitter of sulfur dioxide (SO2), posing severe challenges to human health and the sustainable development of social and economic. Based on OMSO2e products, this paper analyzed the spatial and temporal changes of atmospheric SO2 column concentrations in China from 2005 to 2020 and used MEIC emission data and socio-economic data to explore the main factors affecting SO2 changes in China's 10 economic regions. The results show that:(1) Over the past 16 years, SO2 has decreased in a fluctuation way, with a slight increase in Xinjiang and the Qinghai-Tibet Plateau, while other regions showed a significant decreasing trend. (2) SO2 exhibited large inter-annual variation and displayed a spatial distribution pattern of high levels in the east and low levels in the west. The northern coastal areas (NC) and the middle reaches of the Yellow River (MYR) had the highest annual average concentrations and coefficients of variation. (3) SO2 was positively correlated with the proportion of industrial sources, residential sources, power sources, transportation sources and secondary industries in GRP while it was negatively correlated with population density, industrial emission gas treatment facilities and associated expenses. (4) Changes in emission sources were the main factors influencing variations in SO2. This paper provides a theoretical basis and reference for formulating relevant emission reduction policies and ecological environmental protection in China.
2023 Vol. 43 (11): 5678-5686 [Abstract] ( 199 ) [HTML 1KB] [ PDF 2827KB] ( 1622 )
5687 Numerical wind tunnel experiment on surrounding air flow field characteristics of the desertified patchy meadow
WANG Zhi-jun, ZHANG Kai-he
In order to explore the mechanism of wind-sand erosion under the condition of patchy meadow underlying surface in desertified grassland, here in this paper, the meadow is generalized as porous medium for geometric modeling and the turbulence model is improved by additional porosity source terms in order to accurately characterize the interference effects of meadow on incoming air flow. Subsequently, based on the meadow coverage condition in the field test of Hesp (2019), the Standard k-ε, RNG k-ε and Realizable k-ε models are validated and optimized to achieve the model improvement. By referring to the wind speed near the ground (at 2m height) in the Maqu section of the Upper Yellow River, the numerical wind tunnel experiments of flow field characteristics around a single patchy meadow (1m×1m) were carried out under the conditions of meadow coverage of 15.75% (sparse), 31.05% (moderate) and 60.15% (dense) and forward threshold wind speed of 7m/s(low), 11m/s (medium) and 15m/s (high). The results show that a semi-circular low-speed zone on the windward side and a semi-elliptical shelter zone on the leeward side occur generally in the horizontal direction surrounding the meadow, the latter of which expands radially along the wind and accelerates in part on both sides. Moreover, for the vertical direction, the wind speed distribution generally shows the law of weakening on the windward side, sudden acceleration directly above, and large-scale deceleration on the leeward side. When the coverage is constant, the average wind speed around the meadow increases corresponding to the increase of the incoming wind speed. When the incoming wind speed remains constant and the coverage increases, the average wind speed on the leeward side of the meadow increases first and then decreases. The wind speed distribution around the meadow conform to the law of normal distribution, with a high narrow peak on the windward side and a low broad peak on the leeward side. The wind speed profile on the windward side can be fitted as the variogram of the Gaussian model, and the wind speed variogram on the leeward side closely relates to the incoming wind speed and coverage. The improved RNG k-ε turbulence model proposed in this paper can be used as a mathematical model to accurately characterize the complex air flow around the flexible meadow, which is also expected to provide a theoretical foundation for further numerical simulation of the wind-sand flow field for medium and large scale meadows.
2023 Vol. 43 (11): 5687-5699 [Abstract] ( 133 ) [HTML 1KB] [ PDF 2268KB] ( 768 )
5700 Characterization and vapor intrusion risk assessment of VOCs in contaminated sites based on soil gas
HAO Chen-yu, ZHONG Mao-sheng, JIANG Lin, LI Ji-hong, MA Lin, WANG Yang
Contamination characterization and vapor intrusion risk evaluation based on volatile organic compounds (VOCs) in bulk soil were recommended in the technical guidelines of China. However, these guidelines are found to be full of uncertainties in practical use. To evaluate its effectiveness, ten boreholes were drilled within an area contaminated by benzene in a decommissioned site, and 63 paired soil and soil gas samples were collected and analyzed following the technical guidelines. The results revealed that benzene profiles in the soil were similar, as revealed by both the soil and soil gas analyses. The benzene content in 35% of soil gas samples was above the screening level of 1.242mg/m3, and it was distributed in all the ten boreholes. The maximum concentration was nearly 1000 times the screening value. However, in only 5% of soil samples, benzene content was above the soil screening value of 1mg/kg, and the maximum concentration was about 30 times the screening value. Therefore, it can be concluded that analyzing the bulk soil may underestimate the VOC contamination in sites, especially for sites composed of sandy formations. The risk quantified based on soil contents using the linear partition equation was about one order of magnitude higher than that estimated based on measured soil gas concentration. The reason is that the partition of VOCs among soil solid, water, and vapor phases does not follow the linear equilibrium partition exactly due to the aging and sequestration of contaminants by organic matter in the soil. The vapor concentration is highly overestimated using the linear equilibrium equation. Additionally, risk can be overestimated by over two orders of magnitude without considering biodegradation throughout the intrusion process for VOCs (e.g., BTEX) that can be degraded. The results may be entirely different. Therefore, systematic research on VOC contamination and risk characterization, as well as relevant technical guidelines based on soil gas, is suggested to be initiated.
2023 Vol. 43 (11): 5700-5708 [Abstract] ( 175 ) [HTML 1KB] [ PDF 1247KB] ( 1413 )
5709 Removal of Hg0 from smelting flue gas by FeSO4-flocculated sludge activated with sulfuric acid
LI Hong-hu, PENG Xi-yan, AN Miao, LI Jia-yi, CAO Yan-xiao
A kind of adsorbent (SSXTY) with excellent performance on efficiently capturing Hg0 in smelting flue gas was prepared from ferrous sulfate-flocculated sludge with sulfuric acid activation. H2SO4 activation could improve the adsorbent pore structure and increase the active surface oxygen/sulfur species, thus leading to the enhanced mercury removal activity of the adsorbent. Moreover, the SO2 resistance of the adsorbent was greatly improved, which could effectively overcome the inhibition effect of SO2 in actual working conditions. Pyrolysis temperature and H2SO4 addition ratio showed significant effects on the mercury removal activity of adsorbent. SS25T650(H2SO4 addition ratio of 0.25 and pyrolysis temperature of 650℃) exhibited the highest mercury removal efficiency (95.4%). Using flocculated sludge to produce mercury adsorbent not only reduces the adsorbent cost, but also provides a potential way for the resource utilization of flocculated sludge. SSXTY has the advantages of simple preparation method, low cost, excellent SO2 resistance and prominent mercury removal performance, thus showing promising application prospects.
2023 Vol. 43 (11): 5709-5718 [Abstract] ( 161 ) [HTML 1KB] [ PDF 2162KB] ( 1658 )
Water Pollution Control
5719 Nitrite accumulation characteristics in a SO32--driven partial autotrophic denitrification process
NIE Yu-ting, ZHOU Xin, PING Cai-xia
This study developed a novel process of sulfite-driven autotrophic partial denitrification (SDAPD) to achieve the rapid accumulation of NO2--N. Anaerobic sequencing batch biofilm reactors were used to explore the effects on nitrite accumulation under different influent nitrate concentration (25~250mg/L) and different S/N molar ratios (0.8,1.7,2.6). The results show that nitrite accumulation rate (NAR) increased with the increase of influent nitrate concentration, and the S/N can significantly affect the NAR. The NAR was the highest up to (64.7%±3.0%) at S/N of 1.7. Periodic experiments show that nitrate reduction and nitrite accumulation were accompanied by sulfite removal and sulfate production. High S/N could promote the production of protein and polysaccharide in extracellular polymer (EPS) and increase the ratio of PN/PS. Three-dimensional fluorescence spectra shows that the tryptophan was the main component of EPS in SDAPD system, and its fluorescence peak and fluorescence intensity were closely related to S/N. High-throughput sequencing found that Thiobacillus and Thermomonas were key bacteria with the function of sulfur autotrophic denitrification.
2023 Vol. 43 (11): 5719-5727 [Abstract] ( 139 ) [HTML 1KB] [ PDF 1488KB] ( 1046 )
5728 Effect of biochar on the removal of nitrate and N2O emission from water by a screened denitrifying bacterium
WANG Chao-xu, LI Yuan-kun, LIU Yong-chao
To investigate the effect of modified biochar on microbial removal of nitrate with low concentration and N2O emission from water, FeCl3-, H2O2- and NaOH-modified biochars (BC-Fe, BC-H2O2, and BC-NaOH) were prepared by utilizing the pristine rice husk-derived biochar (BC) and characterized further. Meanwhile, a strain of denitrifying bacteria, Raoultella ornithinolytica strain KK1, was screened from activated sludge. Then BC, BC-Fe, BC-H2O2, and BC-NaOH were incorporated into the incubation system containing the strain, respectively and a control treatment without any biochar addition was also setup. The indoor incubation experiment on the microbial removal of nitrate (about 10mg/L, in terms of N) from simulated wastewater was carried out and the dynamic changes of N2O emission rate and NO3--N, NO2--N, NH4+-N, TN, and dissolved organic carbon (DOC) concentrations during incubation were analyzed. Results showed that the average NO3--N degradation rate of the screened strain was 0.10mg/(L·h) within 120h. Compared with BC, the carboxyl and lactone contents of BC-Fe and BC-H2O2 significantly increased and their oxidizing ability was enhanced, while the phenolic hydroxyl content of BC-NaOH significantly increased and its reducing ability was enhanced. Meanwhile, the total acidic oxygen-containing functional group contents of BC-Fe and BC-H2O2 significantly increased by 57.17% and 22.86%, respectively compared with BC, while the total basic oxygen-containing functional group content of BC-NaOH significantly increased by 91.67%. Compared with BC, BC-Fe and BC-H2O2 promoted the reduction of NO3--N by denitrifier, and the cumulative N2O emissions were 3.11 and 2.17 times higher than that of the treatment with BC addition, respectively; while BC-NaOH inhibited the reduction of NO3--N by denitrifier, and the cumulative N2O emission was only 49.63% that of the treatment with BC addition. The impact of biochar on microbial denitrification and N2O emission is attributed to the differences in pH value, DOC content, and redox property of biochar caused by modification.
2023 Vol. 43 (11): 5728-5736 [Abstract] ( 135 ) [HTML 1KB] [ PDF 972KB] ( 1510 )
5737 Comparison of foam characteristics in biological treatment units and water supply outlet of municipal wastewater treatment plant
WANG Fang-shu, GUO Jia, LI Ji-cheng, YANG Chuan-xi, MA Ying-zi, DONG Xiao-wan, CHEN Dong
This study comprehensively analyzed the foam characteristics of the samples collected from the aerobic tank (H), MBR tank (M), and ecological water supply outlet (B) of a wastewater treatment plant located at Qingdao regarding water quality index, organic components and microbial community structure. Compared with H and M, the TOC, TN, protein, UV254 and DO concentrations of the foam mixture collected from B were significantly higher, while its surface tension and viscosity were slightly lower. For the organic composition, the alkanes and fatty acids concentrations of B were much higher than that of H and M, while its BFK concentration was significantly lower. It was also found that the main organic component of the three sampling points was protein which might belong to Mucin and Nisin due to the high matching points. In comparison with H and M, the proportion of fulvic acid humus of B was higher, while its protein was lower. These results indicated that BFK was the primary foaming agent for H and M, and hydrophobic protein and fulvic acid humus were the main foaming agents. However, BFK and LCFAs were the dominating foaming agents for B, and alkanes, hydrophobic proteins and fulvic acid humus were the main foaming agents. It should be noted that the microbial community of B was significantly different from that of H and M. For the microbial composition at the phylum level, the proportion of Proteobacteria of B was up to 97.27%, while the main bacterial of H and M were Actinobacteriota, accounting for 58.5% and 47.9%, respectively. Moreover, the principal genera of B were g_unclassified_Acidovorax, s_uncultured_g_Undibacterium and Pseudomonas, while that of H and M were Skermania and Candidatus Microthrix.
2023 Vol. 43 (11): 5737-5745 [Abstract] ( 142 ) [HTML 1KB] [ PDF 1031KB] ( 1511 )
5746 Degradation of chlorophenolic pollutants in Fe3O4-nZVI Fenton-like system
ZHONG Jin-kui, LI Wen-qing, XIE Ya-rui, LI Jing, WEI Jia-he
The ferriferrous oxide supported nano zero-valent iron (Fe3O4-nZVI) was prepared by co-precipitation and liquid phase reduction method, and used as heterogeneous catalysts with H2O2 of Fenton-like systems to degrade chlorophenols (CPs) in wastewater, such as p-chlorophenol (4-CP), 2,4-dichlorophenol (2,4-DCP) and 2,4,6-trichlorophenol (2,4,6-TCP). The characterisation results of SEM, EDS, XPS, XRD and VSM showed that Fe3O4-nZVI was a nanoscale magnetic composite that could be recycled by magnetic recovery and could promote the circulation of Fe2+ and Fe3+ and increase the yield of HO·. The fitting parameters of kinetics showed that the degradation process of three kinds of CPs in Fe3O4-nZVI Fenton-like system fitted the pseudo-first-order kinetics model (R2>0.9). Under the optimization conditions, which were reaction temperature 25℃, Fe3O4:nZVI=1:1 (mol:mol), pH=3, H2O2 15mmol/L, CPs 40mg/L, and Fe3O4-nZVI 0.6g/L, the degradation rates of 4-CP, 2,4-DCP and 2,4,6-TCP by Fe3O4-nZVI Fenton-like systems were 96.28%, 98.77% and 98.03%, respectively. The degradation rates of three kinds of CPs were in the order of k4-CP>k2,4-DCP>k2,4,6-TCP. The degradation rates of CPs decreased with the increase of chlorine atoms on the benzene ring. The quenching experiments and mass spectrometry results indicated that HO· oxidation and substitution dechlorination played a critical role on degrading CPs.
2023 Vol. 43 (11): 5746-5756 [Abstract] ( 126 ) [HTML 1KB] [ PDF 978KB] ( 1467 )
5757 Degradation emerging contaminants and mitigation membrane fouling by electrochemical activation of persulfate
LIU Yin, XU Qi-bin, SONG Zi-heng, LIU Suo, ZHAO Chun
The occurrence of membrane fouling and the poor retention effect of small molecular organic pollutants have been important factors limiting the development of ultrafiltration technology. This study realized the mitigation of membrane fouling and the removal of small molecular organic pollutants (SMOP) in the ultrafiltration process by coupling advanced oxidation technology. Cross-linked polypyrrole carbon nanotubes were deposited on the surface of polyvinylidene fluoride (PVDF) membrane by spraying, and the crosslinked polypyrrole carbon nanotubes composite ultrafiltration membrane (CP/PVDF) with excellent conductivity was obtained. The performance of fouling mitigation (HA as the simulated pollutant) and removing small molecular organic pollutants was compared when peroxymonosulfate (PMS) and peroxodisulfate (PDS) were used as oxidants respectively. The results showed that the E-PS-CP/PVDF system had high removal ratios for three different small molecular organic pollutants, carbamazepine (CBZ), diclofenac sodium (DCF) and sulfamethoxazole (SMX), and its first-order kinetic constants were higher than 15×10-2min-1, much higher than that of the ultrafiltration system alone (the highest was 0.072×10-2min-1). E-PS-CP/PVDF system had obvious membrane pollution mitigation effect.When using PMS and PDS as electrolytes, the normalized membrane flux only decreased to 0.93and 0.84 within 60min, respectively. The applied electric field and the oxidation of oxidizing hydroxyl radicals on HA changed the interaction of pollutants on the membrane surface and reduced the deposition of HA on the membranes. In addition, the fouling mitigation mechanism of E-PS-CP/PVDF system to alleviate membrane fouling was explored through quenching experiments. The results of mechanism experiments showed that the main reason for alleviating membrane fouling in E-PS-CP/PVDF system was the ·OH, SO4·-and 1O2 generated by the cathodic activation of PS, and PMS had better performance as oxidant than PDS. Therefore, E-PS-CP/PVDF system can alleviate membrane pollution and remove small molecular organic pollutants during ultrafiltration, and has a good application prospect in the field of actual water treatment.
2023 Vol. 43 (11): 5757-5764 [Abstract] ( 163 ) [HTML 1KB] [ PDF 1365KB] ( 1240 )
5765 Amine-modified zeolite synchronously cleans nitrate and total phosphorus from water
CUI He, CHEN Yun-nen, LIU Chen, PENG Zhi-ye
In this paper, modified zeolite (ZOC) was obtained by loading natural zeolite (Z) with amine group. The properties of ZOC were analyzed by static adsorption, desorption experiment, and SEM, FTIR analysis. The results showed that when the adsorption temperature was 25℃, pH was 4~9, ZOC dosage was 4g/L (ZOC dosage was 0.6g/L for single phosphate removal), and the initial concentrations of nitrate (N) and total phosphorus (TP) were 50 and 2 mg/L respectively, the removal rates of N and TP were above 83% and 96%, respectively. With 0.5 mol/L NaCl as the desorption agent, the desorption rates of N and TP were above 99% and 97%, respectively, and the removal rates of N and TP could still reach 85.7% and 98.96% after 5 times of adsorption-desorption cycles. The adsorption behavior of N and TP by ZOC conformed to Langmuir isotherm model, and the adsorption process were conformed to the pseudo-second-order kinetic model. ZOC synchronous (alone) purification of N and TP mechanism involved electrostatic attraction and ion exchange.
2023 Vol. 43 (11): 5765-5776 [Abstract] ( 203 ) [HTML 1KB] [ PDF 1386KB] ( 1479 )
5777 Advanced oxidation processes on fruit and vegetable washing
CHAI Song, CHEN Zi-ang, WEI wei, LIU Jian, WANG Yu-jue, ZHAN Ju-hong, ZHAO Er-zhuo
This study investigated the performance of fruit and vegetable washing by seven advanced oxidation processes (AOPs), namely, electrolysis, ozonation, ultraviolet (UV), available chlorine electro-production (E-Cl), hydrogen peroxide electro-production (E-H2O2), UV combined with E-Cl (UV/E-Cl), and UV combined with E-H2O2 (UV/E-H2O2). Results showed that among the seven AOPs, the UV/E-H2O2 process exhibited the best disinfection performance of completely inactivating 7.11logCFU/mL of Escherichia coli within 5 minutes, without observing any photoreactivation. Furthermore, 93.2% of the herbicide atrazine was abated in 10min by UV/E-H2O2 process. Meanwhile, the generation of disinfection by-products was also effectively controlled during this process. Based on these results, a H2O2 in-situ production system was set up with a carbon-polytetrafluoroethylene electrode in the natural air diffusion way, and the lifetime and operational cost of the system were evaluated for practical fruit and vegetable washing. Results showed that the electrode could be used for more than one year under daily use, and the operational cost was 3.9%~13.5% to the price of commercial H2O2.
2023 Vol. 43 (11): 5777-5786 [Abstract] ( 150 ) [HTML 1KB] [ PDF 687KB] ( 1444 )
5787 Research progress on the application of modified skeletal materials for sludge deep dewatering
GE Zheng, ZHANG Yi-xin, LIU Ji-bao, WEI Yuan-song
Regarding the limitations of using raw skeleton materials, this literature reviewed the categories of skeletal materials, modification methods, and the mechanisms of enhancing sludge dewatering. In addition, the prospects and problems of their future application in sludge deep-dewatering were also discussed. The results showed that modified skeletal materials presented better physical and chemical properties which could play vital roles with multiple functions, including mechanical supporting, electrical neutralization, disruption of extracellular polymeric substances, physical adsorption and catalysis, etc., thus to promote deep dewatering. In terms of current state of research, to realize the reduction and utilization of sludge, development of efficient and economical modification methods for practical engineering applications is recommended.
2023 Vol. 43 (11): 5787-5799 [Abstract] ( 256 ) [HTML 1KB] [ PDF 1182KB] ( 2079 )
5800 Characteristics and risk assessment of surface water fluorine pollution in Ningxia section of Yellow River Basin
ZHAO Zeng-feng, FU Yong-liang, QIU Xiao-cong, ZHOU Rui-juan, ZHAO Rui-zhi, YANG Qiang-qiang
In spring (April), summer (July) and autumn (October) of 2019 and 2021, six times were collected at 99 points in the Ningxia section of the Yellow River Basin. The 99 points were divided into 8 water systems which including the main stream of the Yellow River (S1), Qingshui River (S2), Kushui River (S3), Drainage ditch on the north bank of the Yellow River in Weining Section (S4), drainage ditch on the south bank of the Yellow River in Weining Section (S5), drainage ditch on the west bank of the Yellow River in Qingshi Section (S6), drainage ditch on the east bank of the Yellow River in Qingshi Section (S7), and urban landscape River and lake (S8), and the temporal and spatial distribution of fluorine was analyzed, the influence of environmental factors on fluorine enrichment was analyzed, and ecological and health risk assessment was carried out. The results showed that the average fluoride concentration of surface water in Ningxia section of the Yellow River Basin was 1.46mg/L, higher than the standard value of drinking water in China (1.0mg/L). Influenced by evaporation concentration and rainfall dilution, the fluorine concentration changed from high to low in autumn, spring and summer. The exceeding fluorine was the most serious in the Kushui River, Qingshui River and drainage ditch on the east bank of the Yellow River in Qingshi Section, and the main stream of the Yellow River was the only water system that was not polluted by fluoride. The average ecological risk of surface water fluoride in Ningxia section of the Yellow River Basin reached the low risk level, and the medium risk ratio was 27.84% in autumn, 22.33% in spring, and 11.11% in summer. The highest ecological risk of fluoride was found in the Kushui River, with the medium risk ratio reaching 80%. The results of the health risk assessment showed that except for the main stream of the Yellow River, other seven water systems posed health risks to both children and adults, and the harm to children was much greater than that to adults. The temporal and spatial distribution of fluorine was mainly affected by natural factors, and the dissolution of evaporite weathering and evaporation concentration were the main factors of fluorine enrichment in this area.
2023 Vol. 43 (11): 5800-5811 [Abstract] ( 288 ) [HTML 1KB] [ PDF 2192KB] ( 1175 )
5812 Variation of nitrate concentration in karst cave water and its sources and estimation
SU Dan, ZHOU Zhong-fa, GONG Xiao-huan, DING Sheng-jun, DONG Hui, YAN Li-hui, XIONG Yong
Nitrate (NO3-) pollution of groundwater caused by anthropogenic activities has become a significant environmental problem with global concern. Accurate identification of mixing sources of NO3- pollution in aquatic environments is the key to controlling NO3- input and improving water quality. To clarify the distribution of NO3- in karst cave water, this paper selects Mahuang Cave as the research object. A comprehensive analysis of the cave hydrochemistry, the variation characteristics and sources of NO3- and the biogeochemical processes by using the hydrochemical methods and stable isotope values, the results showed that the pH of the water was 8.36 on average, and the main anions and cations were mainly HCO3-, Ca2+ and Mg2+, respectively. The hydrochemical type was Ca·Mg-HCO3 type, and the water was weakly alkaline. The δD-H2O and δ18O-H2O values were distributed near the local atmospheric precipitation line equation, indicating that atmospheric precipitation was the primary source of cave water recharge. The seasonal variation of NO3-concentration in the water was stable, with average values of 13.46mg/L and 13.93mg/L in the dry and wet seasons, respectively. The water quality met the class II water standard (in terms of N). The ratio of [NO3-] and [Cl-] and the isotopic values of NO3- indicated that fertilizer, soil N, manure&sewage, and atmospheric deposition were the mixing sources of NO3- in water. The process of NO3- conversion in water was dominated by microbial nitrification, and no significant denitrification occurred. The results estimated from the SIAR model showed that the average contribution rates of mixing pollution sources to the NO3-content in water during dry and wet seasons were CF(55%), SN(24%), M&S(12%), AD(8%), and CF (52%), SN (24%), M&S (19%), AD (5%), respectively, where CF and SN were the mainly contributing sources of nitrate concentration in the study area, followed by M&S and AD.
2023 Vol. 43 (11): 5812-5822 [Abstract] ( 180 ) [HTML 1KB] [ PDF 2217KB] ( 1085 )
5823 Inversion and identification of groundwater pollution sources based on surrogate model and flow direction algorithm
LUO Cheng-ming, LU Wen-xi, PAN Zi-dong, WANG Zi-bo, XU Ya-ning, BAI Yu-kun
In this paper, the theory and method of simulation-optimization was applied to identify the relevant information of groundwater pollution sources, the hydraulic conductivities of the simulation model, and the pumping capacity of pumping wells simultaneously. First, a numerical simulation model of groundwater contamination was constructed based on a hypothetical example. Then, the BP neural network (BPNN) and kernel extreme learning machine (KELM) methods were applied to construct surrogate models of the simulation model, and the surrogate model with better fitting accuracy was selected and embedded in the subsequent optimization model to reduce the computational load and improve the approximation accuracy of the surrogate model to the simulation model. Finally, the inversion results were obtained by solving the optimized model with flow direction algorithm (FDA) and comparing them with those obtained by sparrow search algorithm (SSA) and particle swarm optimization (PSO) respectively. The results showed that compared with the KELM surrogate model, the BPNN surrogate model had higher fitting accuracy, with the coefficient of determination, the average relative error and the root mean square error of 0.9999, 0.1723% and 0.5625, respectively; compared with PSO and SSA, FDA had faster convergence speed and higher accuracy in solving optimization model. The average relative error of its identification results was less than 7%, which improved the accuracy and efficiency of groundwater pollution source inversion identification and provided a reliable basis for groundwater pollution remediation, risk assessment and liability determination.
2023 Vol. 43 (11): 5823-5832 [Abstract] ( 165 ) [HTML 1KB] [ PDF 955KB] ( 1447 )
5833 Effect of filter medium on operational performance of a constructed wetland-microbial fuel cell system based on electrode dependent ammonium oxidation
FAN Hong-yong, WANG Hua-wei, PAN Ling-yang, CHU Gang, SUN Ying-jie, WANG Zhen
An anodic layer was installed in a constructed wetland-microbial fuel cell (CW-MFC) system based on electrode dependent ammonium oxidation, and this study was conducted to explore the operational performances and the associated microbial characteristics of the CW-MFCs as different kinds of filter media were introduced into their anodic layers. The results showed that, as the CW-MFC based on electrode dependent ammonium oxidation was adopted to treat domestic sewage, physicochemical properties of filter medium filled in the anodic layer could significantly affect microbial community structure of the electroactive ammonium oxidation biofilm and quantities of the associated functional microorganisms in the biofilm, leading to differences of nitrogen removal and electricity generation among the three devices. Compared with quartz sand and zeolite, broken bricks had lager specific surface area, higher EC value and Fe content, resulting that quantities and activities of the functional microbes involved in electrode dependent ammonium oxidation were increased in the CW-MFC filled broken bricks into the anodic layer. Correspondingly, electrode dependent ammonium oxidation was enhanced in the CW-MFC, and operational performance of the system could also be optimized. Regarding to the CW-MFC filled broken bricks into the anodic layer, its COD, TP, TN and NH4+-N removal rates could respectively reached up to (87.29±2.06)%, (92.52±3.20)%, (87.10±2.27)%, and (96.49±0.76)% during the stable operation phase, as well as the maximum power density of 0.60W/m3, effluent quality of the system could reach Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002) class A standard.
2023 Vol. 43 (11): 5833-5844 [Abstract] ( 171 ) [HTML 1KB] [ PDF 1635KB] ( 1635 )
5845 Construction of CeO2/BiOBr heterojuction for photocatalytic degradation of Rhodamine B
GUO Tian-yu, FAN Xiang-rui, BAI De-hao, QI Yu, WANG Hong-Tao
In this study, CeO2, BiOBr and CeO2/BiOBr photocatalysts were synthesized by a hydrothermal method, and the morphology, structure and photoelectrochemical properties of the photocatalysts were characterized by different techniques. The photocatalytic performance was evaluated by degrading Rhodamine B (RhB) under visible light irradiation. The experimental results showed that the CeO2/BiOBr (CB-10) catalyst with the appropriate amount of CeO2 (10%) exhibited enhanced photocatalytic activity, recyclability and cycling stability and the degradation rate of RhB reached 99% within 30min. Furthermore, the catalyst attained the highest degradation efficiency (96.1%) within 20min when the catalyst dosage was 0.5g/L, the RhB concentration was 20mg/L and pH value was 3. The possible reaction mechanism of CeO2/BiOBr heterojunctional material in photocatalytic process was proposed based on the radical capture test and the energy band structure of material. This study can provide a new idea and method for the preparation of Bi-based composite catalysts.
2023 Vol. 43 (11): 5845-5854 [Abstract] ( 195 ) [HTML 1KB] [ PDF 1412KB] ( 1476 )
Solid Waste
5855 Emission characteristics and abatement mechanism of dioxins in the pyrolysis flue gas of scrap copper enameled wire
FAN Chun-long, QIAN Li-xin, DING Long, SHEN Tao, YAO Ming, CHUN Tie-jun, HAN Yi-jiao, LONG Hong-ming
This paper analyzed generation and emission characteristics of dioxins in the flue gas of a 2t/furnace intermittent pyrolysis furnace were analyzed, and a dioxin control technology based on "process inhibition and terminal reduction" was proposed. The effects of adding inhibitors to the pyrolysis process of scrap copper enameled wire in combination with terminal activated carbon adsorption on the emission of dioxins and their congeners were investigated. The results showed that the emission concentration of PCDD/Fs in the pyrolysis furnace flue gas was 54.32ng/Nm3, and the I-TEQ value was 5.30ng I-TEQ/Nm3. The congeners of PCDF were mostly 1234678-HpCDF and OCDF, and the congeners of PCDD were mostly 1234678-HpCDD and OCDD. By applying the technology of "process inhibition and the terminal reduction", the composite inhibitor can reduce the catalytic activity of copper metal and its compounds, lower the concentration of Cl2, and inhibit the de novo synthesis reaction, while the reactive radicals formed during the decomposition of the composite inhibitor can prevent the formation of PCDD/Fs or attack the molecular bonds of PCDD/Fs, thus inhibiting the formation of dioxins. Combined with the physical adsorption of the terminal activated carbon, the dioxin emission concentration in the pyrolysis furnace flue gas was reduced to 1.10ng/Nm3 and the I-TEQ value was reduced to 0.08ng I-TEQ/Nm3, which meets the national environmental protection standard.
2023 Vol. 43 (11): 5855-5862 [Abstract] ( 214 ) [HTML 1KB] [ PDF 1348KB] ( 1787 )
5863 Effect of biochar-loaded sodium anthraquinone-2-sulfonate on anaerobic digestion
ZHANG Yu-lei, MA Jun-yi, AI Ping, ZHAO Li-xin, YAO Zong-lu, YU Jia-dong, LIANG Yi
In order to improve the efficiency of anaerobic digestion system, biochar (BC) was used as a carrier of anthraquinone-2-sulfonate (AQS) for the preparation of composite mediator (BC/AQS) that can be applied in anaerobic digestion system. The batch anaerobic digestion experiment was carried out at mesophilic condition (35℃) to explore the effect of BC/AQS on anaerobic digestion of corn straw. The results showed that when the AQS loading concentration was 1mmol/L, BC/AQS performed best in enhancing methane production efficiency. On this condition, the maximum methane production rate (Rmax) reached 10.64mL/(d·g), the maximum cumulative methane production (Pmax) reached 240.41mL/g, and the cumulative methane production per unit volatile solid (VS) respectively increased by 20.60% and 12.11% compared to the control and treatment solely added BC (P<0.05). The archaea enriched by BC/AQS were Methanosarcina and Methanofollis. In addition, BC/AQS promoted the generation of volatile fatty acids (VFAs) in the early stage of digestion, resulting in an increase of 7.73% to 18.54% in total VFAs concentration onday 10 compared with the control. In the middle and later stages, BC/AQS promoted the degradation of VFAs. BC/AQS-1mmol/L induced the largest decrease in total VFAs concentration, with a decrease of 77.43%. The potential mechanism may be BC/AQS increased the abundance of hydrolytic acid-producing bacteria including Ruminofilibacter, Proteiniphilum, Fermentimonas and Acinetobacter.
2023 Vol. 43 (11): 5863-5872 [Abstract] ( 137 ) [HTML 1KB] [ PDF 1299KB] ( 1774 )
5873 Effects of the additives on gas emission and enzyme activities during sludge composting
GE Qi-long, WANG Guo-ying, HOU Rui, ZHANG Jing
In response to the issue of elevated greenhouse gas emissions and nitrogen loss during the conventional co-composting of municipal sludge and straw blends, the combined addition of corn straw biochar (CSB) and coal gangue-based zeolite (ZL) was employed. To mitigate emissions of CH4, NH3 and N2O during the composting process, 10% CSB was mixed with varying proportions of ZL (0%, 10%, 20% and 30%) based on the mass ratio of additives to the sludge and corn straw mixture. Meanwhile, an untreated control group was concurrently maintained. The findings revealed that the co-application of CSB and ZL (marked as 10%CSB+ZL) led to a significant augmentation in composting temperature and pH value in comparison to the control. This enhancement facilitated enhanced degradation of organic matter within the compost, with the degradation rates surpassing those observed in both the control group and 10%CSB treatment. The simultaneous application of these two addition agents yielded a reduction in the nitrogen loss during the composting process. Compared with the control, the cumulative emission of CH4, NH3 and N2O in the 10%CSB+10%ZL, 10%CSB+20%ZL, 10%CSB+30%ZL treatments decreased by percentages ranging from 87.81% to 90.87%、41.61% to 57.45%、85.01% to 94.92%, respectively, The cumulative emission of CO2 in these treatments exhibited a substantial increase, ranging from 55.45% to 86.55% relative to the control. Furthermore, enzymatic activities, including dehydrogenase, protease, xylanase and phosphatise, experienced augmentation during the composting process. Biochar functioned as a bulking agent, increasing compost porosity to stimulate microbial growth and bolster related enzymatic activities. Coal gangue-based zeolite contributed to gas emission reduction through an adsorption mechanism. The 10%CSB+20%ZL treatment emerged as the most effective strategy in decreasing nitrogen losses, primarily by curtailing the emission rates of CH4, NH3 and N2O during the composting process.
2023 Vol. 43 (11): 5873-5883 [Abstract] ( 148 ) [HTML 1KB] [ PDF 1182KB] ( 1692 )
5884 The harmless disposal of total cyanide in the spent pot lining derived from electrolytic aluminum industry
CHEN Yu-guang, LI Qing-yun, SHEN Hui-ting, DU Jian-jia, LIN Hong-fei, LIU You-yan
In the present study, the water leaching solution of spent pot lining (SPL) was used as the treated object, and the harmless disposal of cyanide through biodegradation was discussed. The effects of C/N ratio, inoculum amount, medium volume and cyanide concentration on biodegradation were investigated, and the functional genes were analyzed by the method of metagenomics. Results showed that iron cyanide complexes (the main form of total cyanide in the water leaching solution) could be used as the sole nitrogen source for the growth of degrading consortium. The degradation efficiency of 50mg/L total cyanide was achieved (65.2% ±2.1%) within 7days at C/N ratio of 6:1, inoculation amount of 10% (OD600 value of 0.860 ±0.010) and 75mL of medium volume. Some potential genes encoding key enzymes were found in the metagenomics including cyanide hydratase, thiosulfate sulfotransferase and cytochrome bo complex. The biotreatment would provide a new option for the harmless disposal of cyanide in the industrial hazardous waste of SPL.
2023 Vol. 43 (11): 5884-5891 [Abstract] ( 131 ) [HTML 1KB] [ PDF 653KB] ( 2105 )
5892 Effects of carbonization intensity on dewatering performance of municipal sludge and characteristics of lysate——based on Ruyter model
KONG Xin, HOU Yun, GUO Yan-feng, LI Rui-yun, BAI Heng, YUAN Jin
The study used Ruyter model and proposes index of ‘carbonization intensity’. On the basis of the index, the coupling effects of both carbonization temperature and carbonization time on dewaterability of sludge and physicochemical characteristics of produced lysate were analyzed. Furthermore, the mechanism of dewatering performance improvement by hydrothermal carbonization was illustrated as well. Results show that in the lab condition, at the carbonization intensity of higher than 0.12, the water content of treated sludge reduced to 55% after suction filtration, which reached to the level of self-sustaining combustion. The reason for good dewatering performance was due to a series of reactions of macromolecular substances (eg. protein or polysaccharide) under a certain carbonization intensity, such as hydrolysis, polycondensation, decarboxylation. However, in an excessive high carbonization intensity condition (0.21), the degree of aromatization was deepened, which resulted in worse biodegradability of lysate.
2023 Vol. 43 (11): 5892-5899 [Abstract] ( 138 ) [HTML 1KB] [ PDF 1282KB] ( 1635 )
5900 Spatial correlation network and influencing factors of municipal solid waste carbon emission efficiency
GAO Yu-xin, GAO Ming
This paper adopted the undesired output SBM model to measure and evaluate the municipal solid waste carbon emission efficiency in 30 provinces of China from 2005 to 2020. With the help of the social network analysis method (SNA) and the quadratic assignment procedure (QAP), the structural characteristics and influencing factors of the spatial correlation network of municipal solid waste carbon emission efficiency in China were discussed. The results showed that:Except Beijing, Inner Mongolia, Shanghai, Jiangsu and Fujian, the average of municipal solid waste carbon emission efficiency in other provinces was less than 1, and the provinces with higher efficiency were mainly located in eastern region. The tightness of the spatial correlation network of municipal solid waste carbon emission efficiency in China had improved in fluctuation, but there was still room for improvement. The network structure showed good accessibility and stability. The eastern provinces were in the relative center of the spatial network, and played a strong leading role in the spatial network, while the central and western provinces were at the edge, and played an intermediary and transmission role. The spatial correlation network of municipal solid waste carbon emission efficiency was divided into net spillover, net benefit, and broker segments. There were few internal connections among each segment, and close connections between segments,with strong spatial spillover effects. Spatial adjacency difference,economic development level difference, scientific and technological level difference, and municipal solid waste treatment structure difference had a significant impact on the formation of municipal solid waste carbon emission efficiency correlation network in China.
2023 Vol. 43 (11): 5900-5912 [Abstract] ( 184 ) [HTML 1KB] [ PDF 1350KB] ( 1083 )
Soil Pollution Control
5913 Effect and mechanism of biochar application on soil carbon sequestration and mitigation
LI Wen-jie, ZUO Xiang-zhi, WANG Jian, QIN Chao, GAO Yan-zheng
With the proposal of the "double carbon" policy in China, biochar has attracted extensive attention because of its role in increasing the potential of soil carbon sequestration. At present, researchers have done a lot of research on the carbon sequestration and mitigation, but there is no systematic summary of its carbon sequestration and mitigation effects and mechanisms. Therefore, based on the current research progress of the practical application of biochar at home and abroad, the effects of biochar application on soil carbon sequestration and mitigation were systematically summarized. It was expounded that biochar can increase the content and stability of soil carbon pool by relying on its own stability and promote the generation of microbial entombing effect through the soil approach, and increase negative emission potential of biochar by increasing the photosynthesis and biomass carbon pool of aboveground vegetation through the plant approach. In addition, the life cycle assessment (LCA) concluded that the optimization of biochar preparation and the organic integration of biochar system with other bioenergy systems are effective measures to play the positive effect of carbon sequestration potential. Moreover, we summarized the mechanisms of biochar application on soil carbon sequestration and mitigation. It mainly includes:the abiotic oxidation process of biochar is the key to the stability of its carbon sequestration. The application of biochar can increase the carbon sequestration potential of soil ecosystem by providing nutrients and habitats for microbial growth and improving the bioavailability of soil nutrient elements, promoting microbial assimilation and plant growth and development. It can also regulate greenhouse gas emissions by changing soil properties, inhibiting signaling molecules and extracellular electron transfer between microorganisms and enzyme secretion. In addition, biochar combines with soil organic matter and minerals to form organic-mineral complex, and promotes microbial secretion of mycelia, cementing substances and a series of hydrophobic proteins can improve the stability of soil aggregates and increase the stability of soil carbon pool. Concisely, the application of biochar is beneficial to the increase of soil carbon pool content and its carbon sequestration stability. Future research, should focus on the mechanism between abiotic oxidation of biochar, biooxidation and carbon stability, and pay more attention to the role of microbial carbon pump and biochar-organic-mineral interface dynamics in carbon sequestration and mitigation of biochar. This work aims to provide a theoretical basis for the practical application of biochar and ecological sustainable development.
2023 Vol. 43 (11): 5913-5923 [Abstract] ( 162 ) [HTML 1KB] [ PDF 929KB] ( 2937 )
5924 Estimation of VOCs' mass flux depletion and risk assessment at complex contaminated sites
LI Ji-hong, ZHONG Mao-sheng, JIANG Lin, ZHANG Wen-yu, MA Lin, HAO Chen-yu
To reflect the source or mass flux attenuation in actual contaminated sites, Jury model was improved by considering the effect of vertical heterogeneity of site lithology and sublab. The model was compared to the J&E model in predicting volatilization flux, indoor air concentration, health risk assessment. Finally the major influential factors were discussed by using an example of a benzene contaminated site in Beijing. The results showed that the benzene flux into the room predicted by the J&E model remained constant, which was inconsistent with the source attenuation in the actual site. In contrast, the volatilization flux of benzene predicted by the Jury model was initially the largest at the source surface and decreased exponentially with time. However, due to the blocking effect of the soil in the vadose zone and the building subslab, the flux entering the indoor air was relatively low at the beginning and increased with time. By the J&E model, the carcinogenic risk of 7sampling locations exceeded 10-6. However, with the Jury model, the determination of the exposure period was the key factor affecting the risk level. The exposure under the initial stage of source formation (scenario T1), only two locations in the exposure period exceeded the acceptable risk level. Under the mid-term (scenario T2), 4locations in the exposure period exceeded the risk acceptable level, and only under late exposure state (scenario T3), 7locations exceeded the acceptable level of risk. In general, compared with the J&E model, the Jury model was more in consistent with VOCs depletion in the fields by taking into consideration of sources attenuation and vadose blocking effect of mass fluxes.
2023 Vol. 43 (11): 5924-5932 [Abstract] ( 174 ) [HTML 1KB] [ PDF 1134KB] ( 1673 )
5933 Field study on ERT monitoring high-pressure rotary jet repairing PAHs pollution
LIU Di, SONG Quan-wei, LI Ling, HU Jie, WANG Ting-jun, DU Xian-yuan, DENG Yong-feng, KE Han
In this study, sodium persulfate (PS) was selected as the oxidant, Fe0[μm], Fe0[nm, BC-nZVI and NaOH were chosen as activators, and repair PAHs-contaminated soil through high-pressure rotary spraying process by mixture of PS and activators. The high-density electrical resistivity tomography (ERT) technique was employed to monitor the distribution of soil resistivity during the rotary jet process, enabling an analysis of the migration and transformation patterns of the oxidation agents during the remediation process. Additionally, the remediation effects of the 4 agent groups were compared after a 48-hour jet period.The experimental results demonstrated that ERT accurately reflected the locations of pollution remediation, with a maximum deviation of less than 0.5m. The changes in resistivity showed a positive correlation with naphthalene remediation. However, discrepancies existed between the estimated remediation values obtained from fitting curves and the actual remediation values, with errors ranging from 10.3% to 22.6%. Among the tested reagents, carbon-supported iron powder exhibited excellent stability and sustained release performance, leading to an extension of the stable oxidation stage by approximately 8hours after jet. Ultimately, the predetermined remediation area achieved the highest level of pollutant removal in the following order:BC-nZVI>Fe0[nm]>Fe0[μm]≈NaOH.
2023 Vol. 43 (11): 5933-5943 [Abstract] ( 203 ) [HTML 1KB] [ PDF 2297KB] ( 1866 )
5944 Effects of residual plastic film pollution on soil water content and root-shoot growth of maize under drip irrigation condition
HU Qi, LI Xian-yue, SHI Hai-bin, CHEN Ning, ZHANG Yue-hong
To evaluate the impact of the residual plastic film (RPF) amounts on agricultural production, a two-year field experiment was conducted during 2019 and 2020 in Jiuzhuang Agricultural Comprehensive Water-saving Experimental Station, Hetao Irrigation District. The variations of SWC, photosynthetic performance, root-shoot growth, and crop yield were analyzed under different RPF amounts with 0 (CK), 150 (T1), 300 (T2), 450 (T3), and 600kg/hm2 (T4). Moreover, a reasonable field management strategy was formulated. The results showed that SWC in the 0~30cm soil layer under the RPF amount of 0~300kg/hm2 was increased due to the reduction of water infiltration caused by the RPF. However, SWC in the 0~30cm soil layer under the RPF amount with ≥ 450kg/hm2 was decreased due to the formation of preferential flow. Meanwhile, the maize photosynthetic performance, maize root-shoot dry weight, and the root-shoot growth rate were decreased under high RPF amount (≥ 450kg/hm2), especially in the early crop growth stage. The root dry weight, shoot dry weight, and the root-shoot ratio under the T4 treatment were 48.66%, 34.63%, and 18.17% lower than that of the CK, respectively. Additionally, crop yield and water use efficiency (WUE) were limited by the RPF. Crop yield and WUE under the T4treatment decreased by 34.05% and 28.85% compared with that of the CK, respectively. In general, the increase of RPF amount resulted in the decreases of soil water infiltration, maize photosynthetic capacity, maize growth, and maize yield. Therefore, it is of great necessity to determine a reason management strategy for RPF pollution. The reason management strategy would increase root and shoot growth, improve photosynthetic performance, and promote the green sustainable development of the dripped irrigation field under plastic film mulching in Hetao Irrigation District.
2023 Vol. 43 (11): 5944-5953 [Abstract] ( 171 ) [HTML 1KB] [ PDF 1221KB] ( 828 )
5954 Research on soil microplastic separation methods based on density flotation and oil extraction
ZUO Zhen-jiang, WANG Ju, WANG Yan-hui, XU Ming-xiang
To compare the characteristics of soil microplastic separation methods which could meet different usage requirements, this study conducted 12 experimental treatments (S1~S12) based on the density flotation and oil extraction methods, by analyzing the extraction efficiency and cost of microplastics comprehensively, including seven types of microplastics (PP; PE; PS; ABS; PC; PVC; PET) and three particle sizes (2~5mm; 1~2mm; 0.5~1mm). The results showed that:There are differences in the extraction efficiency among extraction methods. Specifically, the extraction efficiency of density flotation (S2~S4) ranged from 89.93% to 96.35% and was significantly influenced by the density of the flotation liquid. The extraction efficiency of the oil extraction method (S5~S10) ranged from 78.57% to 93.33% and was affected by the type of extraction oil (P<0.05), with no significant impact from the amount of oil used (P>0.05). As the density of microplastics increased, the extraction efficiency of the oil extraction method gradually decreased, and it exhibited specific selectivity based on microplastic particle size. The highest extraction efficiency for microplastics was achieved when the particle size was in the range of 1~2mm, exceeding 90%, while extraction efficiency significantly decreased for particle sizes >2mm. The combination of density flotation and oil extraction methods could increase the extraction efficiency of microplastics and reduced differences among different particle sizes, resulting in a more stable extraction effect. Considering both extraction efficiency and cost, three extraction methods were selected to meet different usage requirements:the economical method (S5), the balanced method (S2), and the high-energy method (S3).
2023 Vol. 43 (11): 5954-5960 [Abstract] ( 178 ) [HTML 1KB] [ PDF 424KB] ( 1494 )
Environmental Ecology
5961 Spatial and temporal changes of ecosystem services and driving forces: A case study of Hainan Island
BAI Ting-ting, XU Dong, WU Shao-teng
Based on multi-source remote sensing data and reanalysis data, the spatiotemporal changes of ecosystem services in Hainan Island from 1980 to 2020 were analyzed, and a random forest model was used to explore the driving factors of the spatial distribution of ecosystem services in Hainan Island in the past 40 years, as well as the response of different ecosystem services to human activities and natural factors in the time dimension. The results show that over 95% of the land types in Hainan Island have not changed in the past 40 years. However, the growth rate of construction land in Hainan Island has reached 63.41%, and the expansion was mainly carried out in the form of "occupying farmland and forests". The ecosystem services of forest land were the highest, and the four ecosystem services showed varying degrees of decline, which was significantly related to the decline in ecosystem services in urban areas (P<0.001). There was a significant gradient effect of altitude and climate in the ecosystem services of Hainan Island, and there was a synergistic relationship between all ecosystem services. The main driving factor for the decrease in ecosystem service capacity in Hainan Island was rapid urban expansion. Secondly, the spatial distribution of ecosystem services in Hainan Island was mainly driven by rainfall, soil moisture, actual evapotranspiration, maximum and minimum temperatures.
2023 Vol. 43 (11): 5961-5973 [Abstract] ( 222 ) [HTML 1KB] [ PDF 4613KB] ( 2481 )
5974 Study on trade-offs and synergies of ecosystem services based on mechanical equilibrium model: A case of the Middle Reaches of the Yangtze River Urban Agglomerations
LIANG Yu-qi, WEI Xiao-jian, JIANG Ping, CAI Jin, XIE Ming-rui
Based on the use of the InVEST model to estimate six ecosystem services in the middle reaches of the Yangtze River urban agglomeration from 2000 to 2020, a mechanical equilibrium model was constructed by selecting three forces through Principal Component Analysis (PCA). The spatiotemporal evolution of ecosystem services and the characteristics of trade-offs and synergies within the study area were assessed based on the magnitude and deviation of the resultant forces. The conclusions can be summarized as follows:the spatial and temporal characteristics of the six ecosystem services during the study period were obvious, demonstrating the trend of increasing water yield, soil retention and net primary production, while decreasing grain production, carbon sequestration and habitat quality. On the basis of the findings of PCA, the three principal components were renamed as regulation support service, food supply service and water production supply service. The average of coordination variable Ftotal was 5.21, indicating a generally basic coordination state. The synergies among ecosystem services improved and the overall structure tended to be more reasonable. Meanwhile, significant regional differences in coordination degree distribution were observed. Coordination skewness θ was mainly distributed in quadrants I, II and VI, with a greater number of dominant areas for water production supply service (I and VI) compared to regulation support service (II). Regarding coordinated mobility, although there was some leapfrog development, its level still needs to be enhanced. All counties and districts should optimize the relationship between ecosystem services depending on regional natural conditions, resource endowments and socio-economic status. The research results can provide references and decision-making assistance for ecological construction and rational land utilization in the research area.
2023 Vol. 43 (11): 5974-5986 [Abstract] ( 129 ) [HTML 1KB] [ PDF 3703KB] ( 1921 )
5987 Analysis on the spatio-temporal evolution of ecological security patterns: A case study over Taiyuan Urban Agglomeration
QI Qiang-qiang, XU Zhan-jun
Taking the Taiyuan urban agglomeration as an instance, Morphological Spatial Pattern Analysis (MSPA) was applied to explore the changes in ecological source areas in the years of 2000, 2010, and 2020, and circuit theory was adopted to identify ecological corridors, ecological pinch points, and ecological barrier points, so as to construct a regional ecological security pattern, clarify the evolution trend of ecological security pattern, recognize the key areas for ecological restoration, and formulate targeted restoration measures. The research showed that the ecological source area of the study area increased from 3083.38km2 in 2000 to 3144.17km2 in 2020 with time, which faced the challenge of uneven spatial distribution, showing a spatial structure of sufficiency in the west and inadequacy in the central and eastern regions. Influenced by the increased ecological source areas, the number of ecological corridors in the region increased from 69 in 2000 to 90 in 2020, enhancing landscape connectivity, of which, the western ecological corridors showed the features of large quantities and short distances, while the eastern and western ecological corridors were of long lengths and high resistance. During the research period, the overall area of ecological pinch points showed an increasing trend, with an increased area of 47.64km2 in 2000 to 97.98km2 in 2010 and a decreased area of 83.77km2; the area of barrier points showed a decreasing trend, with a decreased area of 451.78km2 in 2000 to 395.95km2 in 2020. Those areas should be deemed as a crucial area for ecological protection and restoration. This study was of great significance, providing guidance for regional ecological restoration and landscape planning.
2023 Vol. 43 (11): 5987-5997 [Abstract] ( 218 ) [HTML 1KB] [ PDF 3521KB] ( 1845 )
5998 Analysis of erosion sediment sources in typical Mollisols watershed by composite fingerprinting technique
XU Wei-tao, ZHANG Shao-liang, ZHAO Guang-yin, WANG Hao, ZHANG Cheng-bo, ZHUANG Ya-ru, YAN Peng-ke, LI Chuan-bao, LI Wei, ZHANG Xing-yi
It is an important foundation for the scientific prevention and control of soil erosion to clarify the characteristics of erosion sediment sources in the Mollisols watersheds. Using the Guangrong Village sub-basin in Hailun City as the research object, 25geochemical characteristics of six potential sediment source sites and sedimentation areas in the basin were analyzed, and the best combination of fingerprint factors was determined using Kruskal-Wallis H-test and stepwise discriminant analysis, and the relative contribution of each sediment source site was calculated by a multivariate mixture model. The results showed that 11factors (Mg, Ti, Cr, Fe, Cu, As, Mo, Tl, P, C, K) were identified as the best fingerprint factor combinations with a discrimination rate of 75% and a goodness of fit of >0.80. The contribution of each sediment source site to the sedimentation of the 0~20cm soil layer was in the following order:arable land with a north-facing slope near woodland (53.11%) > arable land with a north-facing slope near road (25.00%) > cultivated land with early reclamation (11.91%) > cultivated land near the watershed outlet (6.57%) > forested land (3.41%) > cultivated land with a south-facing slope (0%). Sediment in the different soil layers of 0~30cm in the sedimentation zone mainly originated from the north-facing sloping cultivated land in the watershed, while the smallest contribution of sediment was found in the cultivated land on the north side of the woodland. Different land use practices within the watershed have a greater influence on the sediment contribution than the topographic factors, however, it is mainly influenced by the topographic factor under the same land use practices. Early human activities such as reclamation and road building had a greater influence on the deep sediment contribution to the sedimentation area, while later cultivation activities had a greater influence on the surface sediment contribution to the sedimentation area. The composite fingerprinting technique based on geochemical feature factors can effectively discern the sediment sources in typical black soil sub-basins.
2023 Vol. 43 (11): 5998-6006 [Abstract] ( 130 ) [HTML 1KB] [ PDF 1011KB] ( 1802 )
6007 Occurrence characteristics and risk assessment of microplastics in Liujiaxia reservoir
ZHOU Tian-hong, ZHANG Jia-qian, MIN Rui, YANG Si-yi, SONG Shang-jian, ZHANG Guo-zhen
Liujiaxia Reservoir was selected as the research area in this paper, and the occurrence characteristics of microplastics in different surface water of reservoir were investigated and analyzed in 2021 and 2022 respectively, meanwhile, the potential ecological risk index (PERI) was used to assess the risk of microplastic pollution in the reservoir area. The results show that:The average abundance of microplastics in surface water of Liujiaxia Reservoir in 2021 is (0.52±0.21) items/m3, and the average abundance in 2022 is (0.58±0.17) items/m3. The abundance level is significantly lower than that of domestic lake-type water bodies, slightly lower than that of river type water bodies, similar to that of reservoir type water bodies, and higher than that of the downstream ocean Bohai Sea. Fourier infrared spectroscopy and microconfocal laser Raman spectroscopy were used to identify the types of microplastics, which are mainly polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), polystyrene (PS) and polyvinyl chloride (PVC). The microplastics are mainly fragments and fibers, and the smaller the particle size, the more the number of characteristics. The potential ecological risk of microplastics in the surface water of Liujiaxia reservoir in 2021 is low, and the abundance of microplastics in the reservoir in 2022 is high, but the polymer type is relatively less toxic and has no significant ecological risk.
2023 Vol. 43 (11): 6007-6015 [Abstract] ( 230 ) [HTML 1KB] [ PDF 1661KB] ( 1836 )
6016 Oxalate enhanced heterogeneous photo-Fenton activity of natural iron mineral for naphthol degradation
HU Cai-ping, SUO Jin-ran, DING Guan-tao, XU Tian-yuan, WEI Shan-ming, WANG Kun
In this study, the structure and composition of the natural iron mineral collected from Maanshan were characterized, and the box-plot design (BBD) of the response surface method was used to evaluate the influencing factors. Moreover, the mechanism of enhanced heterogeneous photo-Fenton activity by oxalate was discussed. The characterization result show that the Maanshan iron mineral is mainly magnetite. The performance evaluation results reveal that oxalate can significantly improve the heterogeneous photo-Fenton activity of the iron mineral, and the removal rate of naphthol increased from 40% to >99% after oxalate addition. The BBD design shows that the dominant factor affecting the degradation of naphthol was oxalate concentration, followed by H2O2 concentration. The EPR results reveal that introducing oxalate could significantly improve the generation of CO2·- and O2·-. The efficient catalytic degradation of naphthol was mainly attributed to the photolysis of iron oxalate complexes formed on iron mineral, which can accelerate the production of O2·-. Additionally, the produced Fe(Ⅱ) can accelerate the generation of ·OH via Fenton reaction. The findings can provide guidance for the development of green environmental water pollutant control technology using natural minerals.
2023 Vol. 43 (11): 6016-6024 [Abstract] ( 171 ) [HTML 1KB] [ PDF 1993KB] ( 1621 )
6025 Temporal and spatial variation of heavy metals in coastal wetlands around the Bohai Sea and analysis of their sources
JIAN Rui-feng, YUE Fu-jun, ZHU Zhao-zhou, LIU Xiao-long, ZHANG Lu-yao
In this study, published data was collected and Nemerow index, pollution load index and principal component analysis methods were utilized to analyze the spatial and temporal variation of heavy metals, pollution levels and sources. The results provided important information for the prevention, control and management of heavy metal pollution in coastal wetlands around the Bohai Sea. The results indicated that between 2000 and 2020, the concentrations of As, Pb, Cd and Cu in the coastal wetlands of the Bohai Sea exhibited an increase while those of Cr, Hg and Zn showed a decrease. In terms of wetland surface sediment composition, changes in As and Ni were minimal whereas contents of Cr, Cu, Zn and Hg increased while those of Pb and Cd decreased. Additionally, there was an increase in Cr and Zn content within the surface wetland soil while contents of As, Cu, Ni, Pb, Cd and Zn decreased. The single-factor pollution levels of Cd and Hg in heavy metals in coastal wetlands around the Bohai Sea were high, which were 2.67 and 2.57. In the 2010s, the levels of heavy metal pollution in the coastal wetlands of the Bohai Sea were high, and the Nemerow index and Pollution Load index of water, sediment and soil were 1.53, 4.49, 2.52 and 0.34, 0.96, 1.44, whereas they remained at a low level in China's three economic regions. Cu, Ni, Cr, Zn, As have minimal impact on the environment of the coastal wetlands of the Bohai Sea as they were primarily derived from natural sources and only a minor contribution from anthropogenic sources. Cu, Ni, Cr, Zn and As had a limited impact on the environment of coastal wetlands in the Bohai Sea due to their predominantly natural sources with minor anthropogenic sources; whereas Hg, Pb and Cd posed significant environmental risks to these wetlands primarily as a result of heavy industries and light industries closely linked to them.
2023 Vol. 43 (11): 6025-6038 [Abstract] ( 122 ) [HTML 1KB] [ PDF 1256KB] ( 1789 )
6039 Analysis of urban heat island effect and influencing factors based on the “source-sink” landscape pattern: a case study of Hefei
DI Jun-nan, SU Tao, LEI Bo, LIU Xin-bei, MENG Cheng, XU Liang-quan, WANG Ren-yi
Hefei, which has the highest urbanization growth rate among the three provinces and one city in the Yangtze River Delta, was selected as the research area. The "source sink" landscape of urban heat islands was identified by extracting surface temperature and sensitive remote sensing indices to surface features such as vegetation index, moisture index and impermeable surface index, and then the study was conducted combined with the urban heat island effect and the contribution of land use types to the "source" landscape. The results showed that the heating impact range of the "source" landscape in Hefei was 150m, and the "source-sink" landscape pattern could effectively alleviate the urban heat island effect. The degree of relief showed a strong to weak trend from southeast to northwest, with Lujiang county and Chaohu city having the best relief effect, while Shushan district and Yaohai district having the worst relief effect. The smaller the ratio of the "source sink" landscape area and the effective particle size scale of the "source" landscape, the standard shape index of the "source" landscape was between 0 and 0.35, and the more dispersed the landscape patches, the better the degree of relief of the heat island effect. For any land feature patch, the temperature rise caused by the heat island effect will weaken the inhibitory efficiency of the "source-sink" landscape pattern on the heat island effect. Increasing forest cover is one of the effective means to reduce regional warming and alleviate regional heat island.
2023 Vol. 43 (11): 6039-6050 [Abstract] ( 152 ) [HTML 1KB] [ PDF 994KB] ( 2420 )
6051 Capacitive deionization technology and its application in heavy metal separation and recovery
REN Yan-na, NIE Lu-jie, WANG Lei, WANG Xu-dong
Capacitive deionization (CDI), as a promising water treatment technology, is of great significance for the resource recovery of heavy metal wastewater. This paper describes the characteristics of conventional capacitive deionization (CDI), membrane capacitive deionization (MCDI), flow-through capacitive deionization (FT-CDI), inverted capacitive deionization (I-CDI), flow-electrode capacitive deionization (FCDI), and hybrid capacitive deionization (HCDI) systems, and analyzes the factors affecting the performance of heavy metal ion removal. The conclusions indicate that the removal performance of heavy metal ions is closely related to the equipment configurations, electrode materials, solution properties and operating conditions. Finally, combined with the recent application achievements of CDI technology in the separation of heavy metal ions, the future development direction of CDI technology was prospected, in order to provide reference for the research and application of CDI technology in the field of heavy metal wastewater treatment.
2023 Vol. 43 (11): 6051-6062 [Abstract] ( 178 ) [HTML 1KB] [ PDF 489KB] ( 3477 )
6063 Multi-scenario simulation of the impact of regional land use change on carbon reserve
WANG Zhi-yuan, WU Fan, WAN Ding, ZHANG Kao, LI Long-bin, HUANG Chun-hua
Taking the Dongting Lake Ecological and Economic Zone as an example, this study uses the InVEST model to evaluate the effect of land use changes from 1990to 2020on carbon reserve. The study also uses the Markov-FLUS model to simulate the land use changes and their effects on carbon reserve in 2030 and 2060 under four scenarios:natural evolution, arable land conservation, ecological conservation, and comprehensive conservation. The results show that the ecological and economic zone of Dongting Lake from 1990 to 2020 shows a decrease in the area of arable land, forest land, and grassland and a continuous increase in the area of the watershed, construction land, and unused land. The overall carbon stock in the region is high, but the change in land use causes the regional carbon sequestration capacity and potential to decrease. The regional carbon stock decreases by 0.433×106t in total from 1990 to 2020. Under the four scenarios, the region shows a more significant change in construction land in 2030 and 2060. In the integrated scenario, the increase of construction land is better controlled. The carbon stocks in the Dongting Lake eco-economic zone in 2030 and 2060 are respectively 19.927×106t and 19.696×106t for the natural evolution scenario, 19.891×106t and 19.903×106t for the arable land protection scenario, 19.952×106t and 19.873×106t for the ecological protection scenario, and 20.004×106t and 19.949×106t for the comprehensive protection scenario. Considering a comprehensive assessment that takes into account both the utilization of arable land and the preservation of ecological systems, it becomes evident that the regional capacity for carbon sequestration demonstrates a significant degree of robustness. The study outcomes contribute to the establishment of a spatial arrangement of national land areas with a high carbon sink potential, thereby serving as a foundation for attaining regional carbon equilibrium and optimizing land use structure.
2023 Vol. 43 (11): 6063-6078 [Abstract] ( 209 ) [HTML 1KB] [ PDF 3432KB] ( 1983 )
6079 Stable isotopes research on water sources of dominant plants in a river wetland at the middle reaches of the Yellow River
XU Xiu-li, LI Yun-liang, GUO Qiang
Plant water source along the Yellow River is considered to be a foundation to reveal mechanisms of regional wetland evolution, due to the national strategy of ecological protection and high quality development of the Yellow River basin. This study investigated the characteristics of hydrogen and oxygen isotopes of rainfall, river water, groundwater, soil water and the xylem water for five dominant plants in the typical dry and rainy seasons during 2019, taking the Fen River estuary wetland as an example. The replenishment water sources of the Fen River wetland were explored using the relationship of δ18O and δD. The proportions of water uptake by different plants were further quantified using a direct inference method and the IsoSource mixing model. Results show that the isotope values of the wetland groundwater were much lower than those of rainfall and the Fen River. Wetland groundwater was rarely replenished by the local rainfall and mainly supplied by the Yellow River water. The shallow soil water at 0~20cm depth was mainly supplied by rainfall, while the deep soil water at 20~80cm depth was recharged by upward fluxes of groundwater and Fen River water. The proportions of plant water source were different among species. In the dry season, herbaceous plants showed niche separation of water use. The Typha minima and Calamagrostis pseudophragmites mainly used shallow soil water, while the Juncellus serotinus mainly used deep soil water and groundwater (89%±23%). The Phragmites australis mainly used the Fen River water, groundwater and deep soil water (86%±19%). However, all of the three herbaceous plants used deep soil water, groundwater and river water in the rainy season, demonstrating a niche overlap of the plant water use. Additionally, water sources of Tamarix chinensis exhibited a seasonal shift, characterizing by multiple sources in the dry season and shallow soil water (68%±5%) in the rainy season. Under future warm and dry climate conditions, T. chinensis is likely to exhibit distinctly survive advantages because of the strong plasticity of water use, while the herbaceous plants may be influenced by intense water competition. The findings of this study could provide significant scientific references for the wetland ecosystem construction in the Yellow River basin, contributing to an improved understanding of the wetland evolution mechanism.
2023 Vol. 43 (11): 6079-6089 [Abstract] ( 161 ) [HTML 1KB] [ PDF 720KB] ( 1805 )
6090 ENA-model based carbon metabolism analysis of the Yellow River Delta
LU Chang, WANG Zhi-yu
The purpose of the study is to explore in depth the intrinsic linkage between carbon metabolism ecological relationships and national spatial utilization in the Yellow River Delta, and to provide a reference for national spatial pattern adjustment and green development. The research was based on the spatial classification system of "ecology-agriculture-urban", using the ENA-model to analyze the carbon metabolism process in the Yellow River Delta from 2000 to 2020, and using the standard deviation ellipse and the ecological relationship change rate(ERCR) to evaluate the spatial and temporal distribution and change characteristics of ecological relationships between spaces. The results of the analysis:In the Yellow River Delta, the carbon metabolism was in disorder from 2000 to 2015 due to frequent phenomena such as the occupation of ecological space by agricultural space, and the positive carbon flow increased significantly after 2015, resulting in a balanced carbon metabolism; The dominant ecological relationships in the study area were competitive, with stronger ecological conflicts over carbon metabolism, and mutualistic symbiotic relationships gradually increased in the northwest after 2015, with the priority area of national land space evolution shifted from south to north; Most of the ecological relationship change rate in the study area satisfy ERCR>0, and the scale of ecological relationship increase or decrease was consistent with the change trend of spatial transfer area. The conclusion of the study:There are still unreasonable utilization of the national space in the Yellow River Delta, and the pressure of carbon metabolism still exists, so it is necessary to further optimize the national spatial pattern and promote green development.
2023 Vol. 43 (11): 6090-6101 [Abstract] ( 202 ) [HTML 0KB] [ PDF 2429KB] ( 1072 )
6102 Stabilization of As(Ⅴ) in contaminated sediment by FeMnMg-LDH
ZHOU Hong-guang, GAN Yan-ping, WU De-quan, YANG Yan-mei, ZHANG Yang, WANG Lu-yao
To address the problem of stabilized remediation of dredged sediment, FeMnMg-LDH materials were prepared by an improved co-precipitation method to achieve passivation of As in the sediment. The effect of FeMnMg-LDH on the passivation of As in dredged sediment under different As contamination levels and humic acid (HA) addition through sediment incubation tests was investigated. The results showed that the FeMnMg-LDH material induced the transformation of mild acido-soluble fraction arsenic (MASF-As) to a more stable form. With the increase of FeMnMg-LDH addition level, the leaching concentration of As in the sediment at high contamination level (250mg/kg As) was reduced to 261.35 μg/L, the stabilization efficiency was up to 80.29%, and the percentage of effective state content decreased from 13.24% to 3.21% (3.0% FeMnMg-LDH addition level). The addition of HA had a certain activation effect on As in the sediment, which increased the leaching toxicity and biological effectiveness of As in the sediment. The activation effect brought by HA could be weakened by FeMnMg-LDH passivation remediation at the activation effect brought by HA was gradually weakened with the increase of the addition amount at the restorer addition levels of 0%~3.0%. The results of correlation analysis showed that the leaching toxicity and bioeffectiveness of sediment As were positively correlated with the percentage of MASF-As and negatively correlated with the percentage of reducible arsenic (RF-As), which indicated that FeMnMg-LDH materials reduced the leaching toxicity and bioeffectiveness of As by changing the morphological distribution of As in the sediment. In conclusion, FeMnMg-LDH can be used as a passivating agent for As in substrates, providing new materials and methods for the passivation remediation of heavy metals in sediment.
2023 Vol. 43 (11): 6102-6114 [Abstract] ( 134 ) [HTML 0KB] [ PDF 1515KB] ( 1452 )
6115 Research on automatic extraction method of thermal discharge
ZHU Xiu-fang, LI Yuan
To solve the problems of low automation and poor timeliness of existing algorithms for remote sensing thermal discharge detection, this study proposes an automated extraction method for thermal discharge based on the single-temporal thermal infrared band, called IForest-SVM. The Fuqing Nuclear Power Plant in Fujian Province was taken as an example to test and verify the proposed method using four Landsat-8 remote sensing images from October 2018 to January 2019. IForest-SVM first uses isolation forest to automatically extract samples of thermal discharge and normal water bodies, then purifies the thermal discharge samples by their spatial adjacency relationship with discharge outlets. After that, a support vector machine is used to extract thermal discharge pixels, and misclassified pixels are removed based on their spatial adjacency relationship with discharge outlets to obtain the final spatial distribution of thermal discharge. The test results show that the average values of user accuracy and producer accuracy of thermal discharge detected by the proposed method on three images on November 15, 2018, December 1, 2018, and January 18, 2019 were 89.69%, 94.97%, and 90.04%, respectively. No false alarms occurred on the image without thermal discharge on October 30, 2018, effectively avoiding false detections. IForest-SVM only requires input of the thermal infrared band of remote sensing images without additional parameters, and has the advantages of good portability, strong applicability, and high automation. It has a good application potential in the real-time monitoring and rapid detection of thermal discharge.
2023 Vol. 43 (11): 6115-6122 [Abstract] ( 113 ) [HTML 0KB] [ PDF 1442KB] ( 1348 )
6123 Seasonal characteristics of CH4 flux in a restored salt marsh wetland at Liao River estuary
XING Qing-hui, CHENG Hao, LIU Si-qi, XU Xue-mei, CHEN Hong, HAN Jian-bo, DU Jin-qiu
Using the Eddy Covariance (EC) technique, the seasonal characteristics of CH4 flux between a restored salt marsh and atmosphere were analyzed and its main influencing factors during the period between 2016~2021 in the Liao River estuary were determined. The results showed that the average diurnal fluctuation trend and range of CH4 flux values were different in four seasons in the restored salt marsh. The CH4 flux fluctuates around zero during the daytime in summer, autumn and winter. The peak CH4 emission occurred at 05:30, 01:30, 02:30 and 09:00 respectively in four seasons. On the whole, the salt marsh was usually shown as a CH4 source before 12:00 and a weak CH4 sink or an insignificant CH4 source/sink after 12:00. Both the amplitudes and average values of the diurnal variation of CH4 fluxes were winter, spring, summer and autumn in descending order in the restored salt marsh. The main influencing factors of CH4 release in the restored area were Ta, PAR and WS. In spring, Ta and CH4 flux were negatively correlated, while WS and CH4 flux were positively correlated, Ta and WS accounting for 43.8% of the CH4 flux variation. In summer, PAR and CH4 flux were negatively correlated, while PAR was significantly positively correlated with CH4 flux. In the restored salt marsh of the Liao River estuary, during the year of 2016~2021, the CH4flux values ranged from -60.9 to 155nmol/(m2·s) in different seasons, the average CH4 flux value was 14.05nmol/(m2·s). In general, the restored salt marsh acted as a CH4 source (5.32gC/(m2·a)), with a global warming potential (GWP) of 198.46g CO2-eq/m2.
2023 Vol. 43 (11): 6123-6131 [Abstract] ( 152 ) [HTML 0KB] [ PDF 759KB] ( 1332 )
6132 Correlational relationship between land use and landscape ecological risks in Inner Mongolia section of middle Nenjiang River
HAO Jun, TIAN Ya-nan, GE Feng, LIU Jia-yu
Inner Mongolia section in the middle reaches of Nenjiang River was an important part of the ecological security barrier in the north of China and played an important role in maintaining the ecological security in the middle and lower reaches of the river basin. This paper analyzed the spatial and temporal succession characteristics of land use pattern in watershed from 2000 to 2020, as well as the landscape ecological risk assessment model had been built. Based on the spatial and temporal succession of landscape ecological risk in the river basin over the past 20 years, the relationship between land use pattern and landscape ecological risk had been revealed. The results showed that in the past 20 years, the land use type in Inner Mongolia in the middle reaches of Nenjiang River was mainly forest land, and the overall pattern of land use had not changed much. However, the area of natural forests, wetlands and dryland had decreased significantly, and the area of paddy fields and artificial reservoirs had increased markedly. The landscape ecological risk area of the basin was mainly concentrated in the lower reaches of the Choer River and the Handahan River. In the last 20 years, the artificial reservoirs were the most obvious type of ecological transition to high risk, which increased from 8.90% in 2000 to 53.99% in 2020. The highest proportion of landscape ecological high risk area was paddy field, followed by dry land, urban land, rural residential area and other building land. Although with little change in global aggregation trends, there was a trend of increasing high-risk agglomerations and decreasing low-risk clusters in local aggregation trends. The land use type with the highest proportion of landscape ecological risk high-high agglomeration area was paddy field, accounting for 33.26% of the whole agglomeration area. Artificial land use types such as paddy fields and artificial reservoir were not only higher than other land use types in landscape ecological risk level, but also higher in agglomeration. This study provided strong support for the structural adjustment of subsequent industries in the river basin and the deepening of ecological protection.
2023 Vol. 43 (11): 6132-6140 [Abstract] ( 149 ) [HTML 0KB] [ PDF 2173KB] ( 1714 )
Environmental Microbiology
6141 Effects of nanobubbles on the manganese oxidation of a manganese-oxidizing fungus Cladosporium sp. and the biogenic mechanism
ZHU Li-na, LIU Yun-si, LI Pan
Manganese-oxidizing fungus Cladosporium sp. XM01 was selected as the organism. The appearance and Mn(Ⅱ) removal rate of Cladosporium sp. XM01in the culture prepared by nanobubble water at different concentrations were monitored to evaluate the impact of nanobubbles on the manganese oxidation of XM01. Meanwhile, XM01gene expression in the culture of various concentration nanobubble water was also assessed to explore the mechanism. The results indicated that, due to the sustained-release and oxygen-enrichment properties of nanobubbles, low concentration nanobubble promoted the manganese oxidation of XM01, while high concentration nanobubble showed opposing result because of high oxygen pressure. Therefore, low concentration nanobubbles could be effectively used to obtain biogenic manganese oxides. In summary, this study aimed to reveal the effects of nanobubbles on the manganese oxidation of manganese-oxidizing microorganisms and further expand the application of nanobubbles and biogenic manganese oxidation in environmental area.
2023 Vol. 43 (11): 6141-6148 [Abstract] ( 150 ) [HTML 0KB] [ PDF 1191KB] ( 1330 )
Emerging Contaminants and Environmental Toxicology
6149 Effects of power frequency electromagnetic environment on development and rhythmic behavior of Drosophila melanogaster
ZOU Xin-ping, WANG Xiao-li, DUAN Zheng-hua, ZHANG Zi-yan, SUN Yong-yan
Differences in development, sleep and movement rhythmic behaviors between W1118 wild-type flies and Rye mutants were investigated under PF-EMF exposure. After continuous exposure for 3 days, the parental flies were removed. Developmental process, movement and sleep rhythmic behaviors of offspring were monitored. The results showed that, the pupal and fly population of W1118 significantly increased respectively by 56.2% and 57.5% under PF-EMF exposure. No significant changes were observed in pupal numbers of Rye type flies, but the fly population significantly increased by 85.2%. No significant change of sex ratio was found under PF-EMF exposure. For W1118 flies, the average number of 24-hour movements was increased by 37.3% after PF-EMF exposure, and 10.6% decrease in the number of 24-hour sleep segments was calculated. For Rye type flies, the average counts of 24-hour movement significantly increased by 50.0% after exposure, and 51.5% decrease of 24-hour sleep segment counts was investigated. In the meanwhile, 45.7% decrease of the total sleep duration were also found. Compared with the W1118 type, the Rye mutants showed more significant changes, which suggested that Rye mutants were more sensitive to PF-EMF exposure. In brief, the PF-EMF environment can impact development and rhythmic behaviors of insects. Increased fly offspring numbers movement counts, and disturbed sleep were found after PF-EMF exposure. Further understandings on the entomological effects of PF-EMF exposure, and reasonable evaluations on the ecological effects of PF-EMF can be provided in this study.
2023 Vol. 43 (11): 6149-6155 [Abstract] ( 224 ) [HTML 0KB] [ PDF 1377KB] ( 1651 )
6156 Research progress on the aging process, leachates of microplastics and their environmental effects
MIAO Ling-zhan, DENG Xiao-ya, YANG Zheng, LI Wan-yi, HOU Jun
Effects of photo-degradation, thermal-degradation, physical abrasion and biodegradation on the aging process of microplastics were reviewed. The relevant laboratory research methods and the key conclusions were discussed. Furthermore, the detection methods of the particulate and dissolved leachates of aged microplastics were summarized, and the toxicity of micro/nano-plastics, their pollutant carrying effects and the impacts of plastic's leachates on aquatic ecosystem and organisms were analyzed. Finally, the future research focuses were proposed. It is suggested that future research should take into account the multiple factors to simulate the natural environment, screen the plastic degrading microbes, establish the technical and methodological standards for plastic's leachates, and reveal the toxic mechanism of leachates from microplastics.
2023 Vol. 43 (11): 6156-6171 [Abstract] ( 234 ) [HTML 0KB] [ PDF 758KB] ( 5108 )
Carbon Emission Control
6172 Carbon total factor productivity, technological progress and efficient catching up in the thermal power sector
GAO Wen-jing, YANG Shu-yi
According to the panel data of selected 30 provinces in China from 2001 to 2021, this paper analyzes the changes and sources of total carbon factor productivity in China's thermal power industry based on the SuperSBM-GML model. And then the threshold model was used to test the nonlinear threshold effect of foreign investment level and R&D intensity on carbon total factor productivity in terms of low-carbon technological progress, energy saving and emission reduction efficiency. The results show that the total carbon factor productivity of China's thermal power industry improved by 1.3% in general, of which low-carbon technological progress was the main source of its improvement. The results of the eight economic zones show that the average efficiency value of carbon total factor productivity in developed economic zones (1.015) was higher than that in less developed economic zones (1.006). At the same time, the catching-up effect of low-carbon technological progress in the developed economic zones was also significantly higher than that in the less developed ones. However, the improvement of energy conservation and emission reduction efficiency was more significant in less developed economic zones. The test of threshold effect of foreign investment level manifests that lower foreign investment level inhibits the positive promotion effect between low-carbon technological progress and carbon total factor productivity; the test of threshold effect of R&D intensity demonstrates that the improvement of energy saving and emission reduction efficiency had a significant positive effect on carbon total factor productivity with the increase of R&D intensity.
2023 Vol. 43 (11): 6172-6182 [Abstract] ( 221 ) [HTML 0KB] [ PDF 954KB] ( 1557 )
Environmental Impact Assessment and Management
6183 Green total factor productivity heterogeneity and promotion choice preference in industrial categories considering environmental undesirable-outputs
LIU Ying, WANG Shi
Based on input-output data of 37 industrial sectors in China from 2011 to 2020, green total factor productivity for different industries were obtained with ML production index and non-radial SBM efficiency measurement model. The study found that only considering carbon emissions could cause overestimation of the productivity, and there was significant industry heterogeneity in green total factor productivity. Through the contribution of green total factor productivity to industrial economic growth, it is demonstrated that China's industrial development mode necessarily further transform from "extensive" growth into "intensive" green growth model. The panel Tobit model was used to test the impact of environmental regulation, foreign direct investment and technological innovation capabilities on green total factor productivity of the industries. Moreover, a panel threshold model was used to consider the nonlinear relationship between environmental regulations and green total factor productivity for the heavy chemical industry, light industry, and high-tech industries, and corresponding threshold values were obtained. The results show that scale of enterprises and R&D inputs had significant positive impacts on the growth of green total factor productivity. Strict environmental regulations increase the threshold for foreign direct investment, while trade barriers and transportation costs make foreign direct investment played a negative role in the growth of green total factor productivity. When the threshold values of the heavy industry were between 3.097 and 3.568, environmental regulations had the strongest promoting effect on the improvement of green total factor productivity. When the threshold values of the light industry and high-tech industries were between 3.035 and 4.269, environmental regulations have the smallest inhibitory effect on the improvement of green total factor productivity.
2023 Vol. 43 (11): 6183-6193 [Abstract] ( 136 ) [HTML 0KB] [ PDF 633KB] ( 2116 )
6194 Environmental impact assessment of recycled PET textile using LCA methodology
SUN Guang-ya, WANG Ya-jun, XU Tong-guang, CAO Xin, CHEN Qing-hua, ZHUANG Ling-feng
Based on the rational of life cycle assessment (LCA), this paper proposes to allocate the environmental impact exerted by PET recycled products otherwise wasted and calculate the environmental loads brought by the manufacturing process using recycling technology and original technology, through using the approach of economic value allocation and the cut-off principle. Moreover, this study conducts normalization and sensitivity analysis of LCA modeling for the manufacturing process. The results show that comparing with the original technology, the PET recycling technology can bring about a reduction of 1640kg of greenhouse gas emissions and 40400MJ of non-renewable energy. Besides, environmental indicators such as Human Toxicity Potential, Eutrophication Potential and Marine Aquatic Ecotoxicity Potential was decreased respectively. Among the six fabrication processes, in-situ reactive compatibilization had the greatest contribution to the total environmental loads, and the consumption of electricity and glycidyl methacrylate should be the key factors to improve.
2023 Vol. 43 (11): 6194-6203 [Abstract] ( 308 ) [HTML 0KB] [ PDF 1091KB] ( 1920 )
6204 Effectiveness evaluation of environmental pollution liability insurance policy: A case study in Jiangsu Province
WU Wen-jing, LIU Miao-miao, MA Zong-wei, FANG Wen, YANG Jian-xun, BI Jun
Based on the insurance information and environmental violation data of 2281 enterprises in Jiangsu Province, this study constructed a difference-in-difference model to empirically examine the effectiveness of environmental pollution liability insurance policies in improving enterprises' environmental performance and explores the potential influencing factors and mechanisms. The result shows that environmental pollution liability insurance effectively improved enterprises' environmental compliance. Still, the policy effect depended on the environmental risk level of enterprises and the cities where they were located:(1) Considering the higher cost of improving compliance performance relative to reduced insurance premiums after risk reduction, enterprises with high environmental risk levels demonstrate a weaker response to the policy; (2) positive effects of the policy tend to be enhanced in cities with high-quality risk assessment and site investigation services. This study provides empirical evidence for the effectiveness of environmental pollution liability insurance policies.
2023 Vol. 43 (11): 6204-6211 [Abstract] ( 137 ) [HTML 0KB] [ PDF 543KB] ( 1916 )
6212 Analysis of the coupling process and the influencing factors of the “water-energy-carbon” relationship in the Hohhot-Baotou-Ordos-Yulin resource-based urban agglomeration
YANG Yi, ZHANG Yuan-yuan
To describe the spatiotemporal evolution of "water-energy-carbon" in the Hohhot-Baotou-Ordos-Yulin urban agglomeration, the level of coupled and coordinated development was analyzed, and a gray correlation model was established to identify the key driving factors affecting the change in the coupled and coordinated levels. The results showed that the water consumption, energy consumption and carbon emissions of urban agglomerations had fluctuating growth from 2005 to 2019, and the coupling coordination of "water-energy-carbon" was low, with urbanization rate, population size and economic development level being the key driving factors affecting coupling coordination. The key drivers of coupling coordination of "water-energy-carbon" in each city had obvious spatial heterogeneity. This study provides a scientific basis for revealing the dynamic change process and driving mechanism of urban ecosystems and formulating differentiated urban environmental management policies in resource-based urban agglomerations in the Yellow River Basin.
2023 Vol. 43 (11): 6212-6224 [Abstract] ( 133 ) [HTML 0KB] [ PDF 1382KB] ( 1639 )
中国环境科学
  News
More>>  
  下载中心
   Instruction
   Template
   Copyright Agreement
More>>  
  Links
   Ministry of Land and
　  Resources of the People,s
　  Republic of China
    CNKI
    WANFANG DATA
    CNPITC
More>>  
 
CHINA ENVIRONMENTAL SCIENCECE
Links： China Association for Science and Technology　Chinese Society For Environmental Sciences　CNKI　WANGFANG DATA
Copyright © 2010 Editorial By China Environmental Science　　Support by Beijing Magtech Co.ltd, E-mail:support@magtech.com.cn