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  Current Issue
 
2023 Vol.43 Issue.12,Published 2023-12-20
Air Pollution Control
Water Pollution Control
Solid Waste
Soil Pollution Control
Environmental Ecology
Environmental Impact Assessment and Management
Environmental Toxicology and Health
Carbon Emission Control
Emerging Contaminants
Air Pollution Control
6225 Forecast of NO2 concentrations based on coupled air quality model simulations and monitoring data using machine learning method
HUANG Yong-xi, ZHU Yun, XIE Yang-hong, LI Hai-xian, ZHANG Zhi-cheng, LI Jie, LI Jin-ying, YUAN Ying-zhi
In this study, built upon the WRF-CMAQ air quality model simulations, a novel machine learning method based on simulations and observations (SOML) that integrating feedforward neural network (FNN) and long short-term Memory network (LSTM) through the Lasso method was developed for forecasting NO2 concentrations, where LSTM was derived based on real-time pollutant and meteorological data. This innovative method was then applied to forecast the NO2 concentrations for three consecutive days for ten air quality monitoring stations in Shunde, Foshan to evaluate the model performance. Our results show that: Compared to WRF-CMAQ and other individual models, SOML gave higher accuracy in the three-day forecast of NO2 concentrations, with the mean absolute error (MAE) of first day at 4.99μg/m3, decreasing up to 66.18%; The accuracy of SOML predictions has significantly improved compared with that of WRF-CMAQ, indicating SOML’s suitable applicability to all seasons (MAE decreased by 42.18%, 42.89%, 61.04% and 50.91%, respectively), particularly in autumn and winter; and Compared with WRF-CMAQ, SOML appears to provide better forecasting accuracy of the spatial distribution as well as the NO2 concentration levels at each station in Shunde.
2023 Vol. 43 (12): 6225-6234 [Abstract] ( 235 ) [HTML 1KB] [ PDF 1382KB] ( 1534 )
6235 Analysis of a winter ozone pollution process in the western Pearl River Delta
MAI Jian-hua, YU Ling-ling, DENG Xue-jiao, OU Hong-hui, YU Xin-yang
Using surface meteorological and air quality observational data, the vertical sounding meteorological data and the reanalysis data, the characteristics and cause of an ozone pollution process in Zhongshan City, located in the western part of Pearl River Delta from December 8 to 12, 2021 were analyzed. The results showed that this process was a rare winter continuous O3 pollution process in recent years, during which the average O3 peak concentration in pollution days was 2.3 times higher than that of non-pollution days of the month. Under the control of subtropical high and the surface cold high ridge during the pollution days, the temperature, sunshine hour and humidity in Zhongshan were relatively high, while the wind speed was relatively low, and the daytime wind direction was dominated by north wind. The downdraft, the inversion layer and the descending relative humidity in the daytime near surface enhanced the ozone pollution. There was a clear phenomenon of external pollutant transport during the pollution process, and the potential sources areas of pollution were mainly located in the northeast direction of Zhongshan. A large amount of NO2 flowed into Zhongshan from upstream areas during the accumulation stage of precursors, providing sufficient precursors for the occurrence of O3 pollution. During the pollution days, under favorable solar radiation conditions, the average photolysis rate of NO2 was 23% higher than that of non-pollution days of that month, leading to a rapid increase in daytime O3 concentration and the formation of pollution under poor diffusion conditions.
2023 Vol. 43 (12): 6235-6245 [Abstract] ( 172 ) [HTML 1KB] [ PDF 2447KB] ( 1250 )
6246 Spatial-temporal correlation effects of CO2-PM2.5-O3 and synergistic control countermeasures in China's provincial area
LI Fei, DONG Long, KONG Shao-jie, QU Zhi-guang, GUO Jin-yuan, ZHOU Yuan-yuan, OU Chang-hong
Spatio-temporal characteristics and correlation effects of CO2 emissions and PM2.5 and O3 pollution concentrations in Chinese provinces from 2015 to 2019 were firstly analyzed. Then, the emission factor method was used to compile the emission inventories of CO2, PM2.5 and O3 precursors in each province from 2011 to 2019, and combined the STIRPAT model the synergistic effects of CO2, PM2.5 and O3 precursors were predicted under different scenarios. Moreover, a rating system was established to identify key control areas with their synergistic effects analyzed by sectors, and finally the targeted synergistic control measures were proposed. The results showed that there was no correlation between CO2 emission reduction and PM2.5 concentration reduction in 53% of the provinces, and that between CO2 emission reduction and O3 concentration reduction in 87% of the provinces. There was a synergistic effect between CO2 and PM2.5 in China from 2012 to 2014, while no synergistic effect from 2015 to 2019. Further, there was a synergistic effect between CO2 and O3 precursors in China in the most years, but there was no general synergistic effect between pollution reduction and carbon reduction. Based on the analysis of the obtained coefficient of synergy effect, more provinces achieved the synergistic effect in the low carbon scenario than that in the baseline scenario. Further, according to the developed rating system, the studied provinces were divided into four levels of control areas. The sectors in the "Class I Control Area" should give priority to the synergistic emission reduction of CO2 and PM2.5, while that in the "Class II Control Area" the synergistic emission reduction of CO2 and O3. It was recommended that each sector should take into account the low-carbon scenario, and the "I and II Control Area" should reasonably regulate the population and urbanization rate, and optimize the energy structure, etc.
2023 Vol. 43 (12): 6246-6260 [Abstract] ( 211 ) [HTML 1KB] [ PDF 3094KB] ( 1183 )
6261 The influence of PM2.5 and component concentration on wind direction in Beijing from 2019 to 2021
CHEN Chen, LI Yun-ting, CHANG Miao, JING Kuan, SUN Feng, GUO Yuan-xi, DONG Xin, SUN Rui-wen, SHEN Xiu-e, LIU Bao-xian
Using the meteorological data, PM2.5 and component concentration data of Beijing from 2019 to 2021, combined with the NO2 concentration, the temporal and spatial changes of PM2.5 and component concentration, meteorological parameters, NO2 concentration and nitrogen oxidation rate (NOR) were analyzed and compared. The results showed that: (1) PM2.5 concentration in urban areas of Beijing decreased by 14% in the three years from 2019 to 2021, but NO3- rebounded by 12%; (2) Each wind was upward, and the order of PM2.5 concentration in urban areas of Beijing was: northeast wind> east wind> southwest wind> southeast wind> south wind> west wind> north wind > northwest wind, in addition, the highest concentration of secondary inorganic salt components appeared in the easterly wind direction, and the highest concentration of organic matter (OM) appeared in the southwest wind; (3) In terms of interannual changes in various wind directions, from 2019 to 2021, the concentration of PM2.5, components and NO2 in Beijing showed the characteristics of high concentration "eastward shift" in space, and NO3- rebounded the highest upward in the northeast wind, reaching 65.7%; (4) The north, northeast and southeast winds were upward, and the relative humidity increases synchronously, and NOR increased synchronously in the northeast and east winds, with an increase of 70%, so it was believed that the rebound of NO3- in the northeast wind in Beijing was related to the eastward shift of precursor concentration and the increase of relative humidity in the northeast wind.
2023 Vol. 43 (12): 6261-6269 [Abstract] ( 161 ) [HTML 1KB] [ PDF 1884KB] ( 1354 )
6270 Sources and risk assessment of atmospheric heavy metals in the vicinity of Dabao Mountain mining area
WU Kai-zhang, LIU Ming, LUO Zhong-hua, CHEN Lai-guo, CAI Li-mei, WANG An-hou, ZHENG Yu, LU Hai-tao
To understand the pollution characteristics and potential ecological and health risks of heavy metals in atmospheric PM2.5 around Dabaoshan polymetallic mining area, PM2.5 samples were collected and analyzed for 15 heavy metals including Al, Ti, Cr, Mn, Ni, Cu, Zn, As, Mo, Ag, Cd, Sn, Sb, Tl and Pb from August 20 to September 10, 2022 and October 18 to November 8, 2022, at Tielong Middle School, Tielong Town, Wengyuan County. The positive matrix factorization (PMF) model was utilized in conjunction with correlation analysis was to identify the source of relevant heavy metals. Additionally, risk assessments were conducted employing both the potential ecological risk model and health risk model. The findings revealed that out of the fifteen metals analyzed in atmospheric PM2.5, Al, Zn, Pb, and Mn exhibited the highest concentrations, collectively accounting for 87.8% of the total measured metal concentration. Their average concentrations were determined as follows: Al (112.70ng/m3), Zn (11.96ng/m3), Pb (68.53ng/m3)and Mn (26.82ng/m3). The remaining heavy metals displayed average concentrations ranging from 0.12ng/m3 to 7.99ng/m3. Variations in seasonal distribution of different metal elements were influenced by the emission from different pollution sources under varying wind directions. Atmospheric PM2.5 primarily contains heavy metals originating from six main sources: cement production (13.8%), metal smelting (24.6%), dust sources (13.7%), sludge disposal (19.4%), traffic sources (9.4%), and a composite source of natural sources and agricultural sources (19.1%). The results of the ecological risk and health analysis evaluation showed that the comprehensive ecological risk level of heavy metals in the study area was classified as “strong”. Specifically, Cd posed an “extremely high” ecological risk, Sb exhibited a “strong” ecological risk, while the remaining heavy metals posed a “slight” ecological risk. The overall non-carcinogenic risk from heavy metals was relatively low. However, Cr presented a significant carcinogenic risk, and both As and Cd carried certain carcinogenic risks.
2023 Vol. 43 (12): 6270-6280 [Abstract] ( 164 ) [HTML 1KB] [ PDF 955KB] ( 1329 )
6281 Analysis of meteorological conditions of a continuous heavy pollution process affecting Lanzhou
YE Yan-hua, ZHANG Ning, WANG Ji-xin, GAN Ze-wen, TIAN Yi-nan
Based on the analysis of a persistent heavy pollution process in Lanzhou from March 14 to 21 in 2021, several conclusions were drawn that the main pollutant was PM10, and the main source was imported dust, there were three sand-releasing processes in the west of Hexi, the west of Inner Mongolia and the middle of Mongolia. The main reasons for the long and heavy pollution process was that the dust continuous input and slowly settled. The main transport routes were Hetao-Ningxia-Lanzhou and Alxa-Southern Ningxia-Lanzhou. The height of dust transport was mainly 1.5~3km. The location and moving direction of the upper surface wind speed, the great value of mixed layer thickness and the local dry and warm index could help to predict dust weather in Lanzhou.
2023 Vol. 43 (12): 6281-6289 [Abstract] ( 158 ) [HTML 1KB] [ PDF 3713KB] ( 1567 )
6290 Ground-based ridar-based investigation of a sand and dust pollution process in Hotan City
YIN Lu-lu, HE Qing, LI Jing-long, MENG Lu, FU Guang-xiang, WU Cai-yun, XIAO Hong-dan, FAN Xu-yu-chen
In May 2022, Hotan City,Xinjiang suffered the strongest sandstorm in nearly five years, and the sand and dust pollution process lasted for a week. In this paper, the changes of particulate matter concentration and the vertical distribution characteristics of aerosol optical information in the process of sand and dust pollution were analyzed by using atmospheric aerosol lidar, pollutant concentration of environmental monitoring station and near-ground meteorological observation data, and the meteorological matching pattern of this polluted weather was obtained by using global reanalysis data, and finally the transport and potential sources of air mass during transit were analyzed by combining HYSPLIT backward trajectory model. The results showed that during the period of sand and dust pollution, the trend of PM2.5 and PM10 was consistent and there was heterogeneity in vertical height, and the average PM2.5/PM10 was 0.25, indicating that coarse particulate matter was the main thing, and the increase of wind speed, temperature and humidity were conducive to the occurrence of polluted weather. During the dust pollution, there was an obvious aerosol layer, and there were significant fluctuations in the vertical direction, and the extinction coefficient, backscatter coefficient and depolarization ratio reached the maximum values of the process, which were 3.5km-1, 0.07km-1·sr-1 and 0.17, respectively. In the spring, Hotan City is in a hot and low-pressure field, and it is difficult to dilute and diffuse pollutants under the background environment of the westerly wind and the surrounding terrain of the Tarim Basin, and the sand and dust air masses have been entrenched here for a long time, which is the reason for the long duration of this pollution. The pollutants in this sand and dust weather process mainly came from the Taklamakan Desert in northern Xinjiang, southern Xinjiang and the surrounding countries of stan, and the pollution sources were mainly the emission contribution of endogenous sand and dust aerosols.
2023 Vol. 43 (12): 6290-6300 [Abstract] ( 199 ) [HTML 1KB] [ PDF 6358KB] ( 769 )
6301 Assessing the impact of condensable particulate matter emissions on PM2.5 pollution in Beijing
LI Hong-lin, SONG Guo-jun, JIANG Yi-jing, JIANG Xiao-qun, LI Chen, SHI Yu
Condensable particulate matter (CPM) is recognized as a precursor to PM2.5. Extensive industrial research in China reveals substantial CPM emissions from coal and gas-fired boilers, cooling towers, and other sources, all potentially contributing to haze formation. Despite its notable impact, CPM is seldom considered in cause analyses of PM2.5 emissions. An analysis of Beijing's air quality monitoring data reveals a significant increase in the PM2.5/PM10 ratio during periods when PM2.5 levels exceed standard limits, indicating a clear and growing trend of secondary pollution. In contrast, the emissions and ambient concentrations of traditional primary precursors, such as SO2 and NO2, are decreasing, displaying no significant correlation with PM2.5/PM10 ratios or PM2.5 accumulation rates. Our estimates suggest that the contribution to PM2.5 in ambient air in Beijing from CPM emissions from gas heating sources is at least equivalent to that from NOx. Additionally, static and high-humidity conditions, conducive to PM2.5 pollution, likely intensify CPM agglomeration and conversion. This study suggests a substantial, previously underestimated, impact of CPM on Beijing's PM2.5 secondary pollution and underscores the need for regulatory oversight on CPM emissions. We recommend the implementation and promotion of advanced technologies for the concurrent benefits of water vapor and waste heat recycling, alongside efficient haze reduction.
2023 Vol. 43 (12): 6301-6312 [Abstract] ( 128 ) [HTML 1KB] [ PDF 1157KB] ( 881 )
Water Pollution Control
6313 The inactivation efficiency of ultrasound combined with UV-LED on tetracycline-resistant Escherichia coli
LI Song-wei, ZHOU Xiao-qin, ZHAO Mei-juan, LI Zi-fu, XIA De-hua
In this study, the inactivation efficiency as well as membrane damage of tetracycline-resistant Escherichia coli under ultrasound at different frequencies (33, 120, 200kHz) and different UV-LED wavelengths (255, 275nm) were evaluated respectively, and furthermore, the optimized operation parameter were selected to form combined ultrasound and UV-LED process to control ARB in sewage effectively. The results showed that 33 kHz ultrasound alone was effective in ARB inactivation, and with an input power of 50 W accumulated to an input dose of 1080 KJ/L, the inactivation rate of Escherichia coli can reach to 2.30 log, while the percentage of cell membrane damage was 61.09%. For UV-LED alone, when 255nm UV-LED irradiated at dosage of 19.92mJ/cm2, the inactivation rate of bacteria and the percentage of cell membrane damage were 5.32log and 2.52% respectively. While the inactivation rate and the percentage of cell membrane damage were 4.63 log and 34.95% respectively for 275nm UV-LED irradiation, but dual-wavelength UV-LED irradiation did not show synergistic effect in bacteria inactivation. However, ultrasound combined with UV-LED can obviously improve the disinfection efficiency, the inactivation rate increased to be 7.45log, the cell membrane damage increased to be 68.74%. Meanwhile, the photoreactivation rate of bacteria after disinfection was reduced to 0.4%. The combination of ultrasound and UV-LED shows great potential in ARB control during wastewater treatment.
2023 Vol. 43 (12): 6313-6320 [Abstract] ( 158 ) [HTML 1KB] [ PDF 1193KB] ( 1222 )
6321 Transport simulation of Pu through fractured media based on continuous time random walk model
HUANG Shi-qi, HU Li-tang, LIU Dong-xu, LIN Jian-feng, TIAN Lei, WANG Dao
Non-Fickian dispersion occurs in the migration of nuclides in groundwater, which is influenced by geological media heterogeneity and physicochemical processes. To improve the accuracy of the simulation of this phenomenon, an alternative model is required. To analyze Pu (plutonium) migration in one-dimensional fractured rock columns, we employed the continuous time random walk (CTRW) model together with the traditional advection-dispersion equation (ADE) to effectively represent Pu breakthrough curves (BTCs). The goodness of fit and feasibility of the ADE, CTRW-TPL, CTRW-TPLA, and CTRW-ETA models were later compared to identify the superior model for simulating Pu transport in fractured media with varying colloidal concentrations. The results indicated that the CTRW-TPL model, which incorporated adsorption, outperformed the traditional ADE in describing non-Fickian migration characteristics. Although the CTRW-ETA model lacked comprehensive migration characterization, its inversion process was more feasible. Furthermore, the migration capacity of Pu in fractured media was significantly enhanced due to colloidal effects. However, beyond a certain concentration threshold, the migration capacity of Pu decreased with increasing colloidal concentrations. Regarding the theoretical framework of the CTRW model, our analysis showed that the generalized transport velocity and dispersion coefficient first increased and then decreased, while the average adsorption rate of solute particles first decreased and then increased. These findings serve as a valuable reference for future research on the parameters of the CTRW model in fractured media.
2023 Vol. 43 (12): 6321-6328 [Abstract] ( 139 ) [HTML 1KB] [ PDF 1087KB] ( 1329 )
6329 Process optimization and degradation mechanism of organic matter in Fenton oxidation treatment of coking wastewater
RAN Yu-fang, XU Chun, LI Xin-peng, GONG Yao, FENG Wei-bo, HU Jia-shuo, ZHAO Cheng-wang
In this study, Fenton reaction was used to oxidize pollutants in coking wastewater, and the degradation effects of time, pH, H2O2/COD mass ratio and Fe2+/H2O2 molar ratio on coking wastewater were investigated. The response surface method (RSM) was used to optimize parameters, and the change rule of organic compounds in the reaction was explored. The results show that Fenton oxidation has a good treatment effect on coking wastewater. Under the conditions of pH=3.19, m(H2O2/COD) 1.72, n(Fe2+/H2O2) 0.74 and reaction time 40min, the COD removal rate was 72.69%. The B/C ratio of treated wastewater increased from 0.24 to 0.32. According to the analysis of organic matter in coking wastewater before and after the reaction, there were 21 kinds of organic matter in raw water, most of which were macromolecular substances with complex types, while the number of organic matter in Fenton effluent was significantly reduced to 14. Among them, nitrogen-containing organic matter was completely degraded, some aromatic compounds in the benzene ring cracked, most of the long chain organic matter was broken into short chain organic matter, and the overall molecular weight decreased.
2023 Vol. 43 (12): 6329-6340 [Abstract] ( 191 ) [HTML 1KB] [ PDF 1372KB] ( 1532 )
6341 Electrocatalytic reduction of nitrate to dinitrogen by Cu2O/CF electrode
GUO Feng, XIE Chen-xin, HAN En-shan, ZHANG Cheng-lei, ZHAO Hui, TENG Hou-kai
During the whole electrolysis process, the electrocatalytic activity of cathode materials is affected by the multi-electron kinetic reaction. Presently, copper-based materials have received much attention as one of the most significant electrochemical nitrate reduction reaction (NITRR) electrocatalysts. However, there are still no reports of effective solutions to the problems of activity limitation and selectivity. In this work, we compared the NITRR performance of s-Cu2O/CF and e-Cu2O/CF catalysts prepared on copper foam (CF) by in situ growth and electrodeposition, respectively. An extremely high NO3- removal rate of 92.1% and N2selectivity of 81.1% were attained by the s-Cu2O/CF catalyst in the electrolyte containing 0.05mol/L Cl- and 100mg/L NO3--N. Cyclic voltammetry and linear sweep voltammetry showed that the NITRR process was achieved by electron transfer between nitrate (NO3-) and Cu0derived from CF. In situ grown s-Cu2O/CF, as a bifunctional catalyst for electronic media or bridge, promotes not only NO3- reduction but also the production of reduced hydrogen (H*), which further enhances the conversion of NO2- to NH4+ or N2. After eight cycles of experiments, s-Cu2O/CF still maintained excellent electrocatalytic activity, which further demonstrates its great application potential in the NITRR. Furthermore, a two-step treatment strategy of Ir-Ru/Ti anodic pre-oxidation and s-Cu2O/CF cathodic post-reduction was adopted to remove 93.6% of chemical oxygen demand (COD) and 75.2% of total nitrogen (TN) from the actual wastewater.
2023 Vol. 43 (12): 6341-6351 [Abstract] ( 132 ) [HTML 1KB] [ PDF 2428KB] ( 1241 )
6352 Reduced graphene oxide supported Fe/Ni nanocomposites for 2,4-dichlorophenol removal
HUANG Xue-zheng, ZHANG Yong-xiang, ZHANG Da-sheng, ZHU Xin-feng, LI Hou-yun
Reduced graphene oxide supported Fe/Ni nanocomposites were prepared for the rapid and effective adsorption and dechlorination of 2,4-dichlorophenol (2,4-DCP) by using liquid phase reduction method. The morphological characterization showed that the spherical Fe/Ni bimetallic nanoparticles with the size of 80~150nm were successfully inserted into the graphene sheets and mainly distributed at the edges and folds of the graphene sheets. The agglomeration of Fe/Ni nanoparticles decreased significantly. XRD patterns and FTIR analysis showed nZVI nanoparticles were successfully embedded into graphene through Fe-O bond, Fe/Ni bimetallic nanoparticles had poor crystallinity and amorphous iron oxide which covered the outer layer of nanoparticles. The effects of different preparation conditions such as carbon iron ratio, nickel loading and reduction degree of graphene oxide on the removal of 2,4-DCP were discussed. The optimum preparation conditions of the Fe/Ni@rGO composites are as follows: the mass ratio of graphene to Fe is 1:2, the Ni loading is 5%, and the molar ratio of NaBH4to Fe2+ is 5:1. The adsorption and dechlorination perfermance of 2,4-DCP by nZVI, Fe/Ni, Fe@rGO composites and Fe/Ni@rGO composites were compared and analyzed. The results showed that the removal efficiency of 2,4-DCP by five materials followed the sequence: Fe/Ni@rGOcomposites>Fe/Ni>rGO>Fe@rGOcomposites>nZVI. However, the cycle test and storage stability test showed: compared with Fe/Ni bimetallic, Fe/Ni@rGO composites had stable reactivity activity and high reruse value. The results demonstrated the removal mechanism of 2,4-DCP by Fe/Ni@rGO composites was the synergistic effect of adsorption and dechlorination.
2023 Vol. 43 (12): 6352-6362 [Abstract] ( 136 ) [HTML 1KB] [ PDF 1400KB] ( 984 )
6363 Optimized preparation of high specific surface area pomelo peel-based biochar by Box-Behnken design and its methylene blue adsorption mechanism
SONG Yong-wei, LUO Hao-wei, YANG Jun, GUO Ze-hao, WANG He-ru, SHEN Zu-wu
Pomelo peel was used as a non-traditional precursor to prepare pomelo peel-based biochar (PPBC) by one-step carbonization-activation method. The effect of three crucial preparation variables, activation temperature (x1), impregnation ratio (x2), and activation time (x3), on the methylene blue adsorption value was investigated by Box-Behnken design (BBD). The results showed that the significance of the single factor affecting the methylene blue adsorption value was x3 > x1 > x2, and the interactive item was x1x3> x2x3 (the x1x2 item was not significant). Under the optimum preparation conditions of activation temperature of 924°C, impregnation ratio of 4 and activation time of 133 min, the maximum methylene blue adsorption value predicted by the model was 216.80 mg/g, and that of the experimental value was 215.69 mg/g. Both of them were in good agreement with each other, which indicated that the constructed response surface model could optimize the preparation process of PPBC very well. In addition, the physicochemical properties of PPBC prepared under optimal conditions were analyzed by BET, SEM, and FTIR, and the adsorption mechanisms of methylene blue were investigated. The surface of PPBC contained abundant and heterogeneous pores with a specific surface area as high as 1222.40m2/g, and its adsorption of methylene blue was mainly through the synergistic effects of pore filling, electrostatic interaction, π-π stacking interaction, and hydrogen bonding. PPBC has the potential as a biosorbent for the treatment of methylene blue dye wastewater.
2023 Vol. 43 (12): 6363-6373 [Abstract] ( 127 ) [HTML 1KB] [ PDF 1333KB] ( 1372 )
6374 Efficient decolorization of azo organics by singlet oxygen from activating PMS with octahedral structured FMN-700
ZHONG Qing, YE Xiao-zhen, ZENG Jing, CAI Lan-yan, WANG Yong-quan, HONG Jun-ming
A catalytic material containing iron and manganese nitride (FMN-700) was prepared by high-temperature calcination using nitrogen-doped Prussian blue analogue (PBA) as a precursor for the rapid degradation of azo organic compounds by activated peroxymonosulfate (PMS). The catalysts were characterized by scanning electron microscopy (SEM), X-ray powder diffractometer (XRD) and Fourier transform infrared spectroscopy (FTIR), which demonstrated that FMN-700 has a layered stacked ortho-octahedral structure and contains Fe-Mn-nitride. The effects of catalyst dosage, PMS concentration and initial pH on the catalytic degradation of azo organics were investigated. The results showed that 99.5% decolorization of RBK5 at 10mg/L could be achieved within 60min at an initial pH of 7, a catalyst dosing of 0.2g/L and a PMS concentration of 2mmol/L. The quenching experiments and Electron Paramagnetic Resonance (EPR) indicated that 1O2 was the main active substance in the degradation system. X-ray photoelectron spectroscopy (XPS) showed that the Fe(III)/Fe(II) and Mn(III)/Mn(II) ratios increased and the pyridine N content decreased before and after the reaction. This process can induce the production of 1O2. The significant increase of fluorescence intensity of 3D-EEM spectrum showed that the azo bond with fluorescence quenching effect was broken during the degradation process and azo organic compounds were successfully decolorized and degraded.
2023 Vol. 43 (12): 6374-6385 [Abstract] ( 147 ) [HTML 1KB] [ PDF 1984KB] ( 1321 )
6386 The influencing mechanism of organic/inorganic components of sludge on chloride migration and transformation during sludge-PVC co-pyrolysis
GU Chun-han, SU Ming-xue, LI Ning, ZHU Bing
In order to achieve the reduction of HCl emissions, the migration and spatial distribution of chlorine with organic and inorganic components in sludge during co-pyrolysis with urban organic solid waste was investigated. The representative organic/inorganic components of sludge and PVC were selected for the co-pyrolysis experiments, and the contribution of different sludge components on chlorine solidification during co-pyrolysis were determined through a neural network model. The results showed that the emission of gaseous chlorine decreased from 93.29% to 58.21%, the chlorine in tar also increased from 4.82% to 32.66%, and the chlorine remains in pyrolysis coke increased from 1.89% to 9.13% with the mixing ratio of sludge and PVC of 3:1. Cellulose, hemicellulose, polysaccharide, protein, and Fe2O3 in inorganic mineral components of sludge mainly promoted the transformation of gaseous chlorine to liquid phase, while lignin and CaO further promoted the transfer of gaseous chlorine to the solid phase. The established neural network model showed that the contribution of the main organic components accounts for 71.35%, and among each component, calcium oxide, in consistent with the experimental results, has the greatest contribution to the chlorine curing rate.
2023 Vol. 43 (12): 6386-6392 [Abstract] ( 189 ) [HTML 1KB] [ PDF 978KB] ( 1243 )
6393 Effects of Sedum lineare Thunb roots at different growth stages on hydraulic properties and water flow migration of vermiculite substrate
CHEN Yu, LIU Rui-fen, LIU De-fu
The study aims to reveal the effect of sedum plant roots at different growth stages on hydraulic properties and water flow migration of artificial substrate for green roofs. Sedum lineare Thunb was cultured in the 14cm-depth vermiculite substrate, and thereafter, plant root characteristics were measured and root length frequency distribution functions were evaluated at 30d, 60d and 90d. Based on root length frequency distribution functions and obtained lysimeter data, hydraulic characteristics of vermiculite substrate containing plant roots were predicted, and the effect of root growth on substrate hydraulic characteristics were analyzed. Finally, water flow migration of Sedum lineare Thunb-Vermiculite substrate under the rainfall condition of a typical hydrological year in Wuhan was simulated by HYDRUS-1D model. The results showed that among three root length frequency distribution functions, errors of predicted root surface area and root volume from the lognormal distribution function were both less than 20%, indicating the function was suitable for the sedum root quantification. The results also showed that the hydraulic characteristic parameters θr、n1、w and Ks of vermiculite containing plant roots were increased, while α2 and n2 were reduced, when compared with parameters from vermiculite without plant roots. During the whole plant root growth stage, θr increased continuously but θs, α2 and w decreased continuously. Compared with data from the simulation scenario of vermiculite without plant roots, evapotranspiration of vermiculite substrate with Sedum lineare Thunb roots from four seasons (spring, summer, autumn and winter) were reduced by 4.46%, 2.94%, 8.91% and 7.56% respectively, and rainfall volume reduction rates were also reduced by 1.64%, 1.22%, 7.10% and 7.06% respectively.
2023 Vol. 43 (12): 6393-6405 [Abstract] ( 97 ) [HTML 1KB] [ PDF 1249KB] ( 1155 )
6406 Size effect of polyethylene terephthalate microplastics on Anammox granular sludge
HONG Xian-tao, ZHOU Xin
To investigate the size-dependent effect of microplastics (MPs) on nitrogen removal performance of activated sludge, the effect of polyethylene terephthalate (PET) on anaerobic ammonia-oxidizing granular sludge (AnGS) at different particle sizes (75~500μm) was explored using the methods of water quality determination, activity test, physicochemical characterization and microbial community analysis in this study. Results showed that the nitrogen removal efficiency of Anammox was lower than that of the control group when 75 and 150μm PET-MPs were dosed, while the 300 and 500μm groups showed superiority over the control group. Anaerobic ammonia oxidation activity (SAA) tests showed similar results. Extracellular polymeric substances (EPS) analysis revealed that the smaller the particle size of PET-MPs, the higher the EPS secretion and PN/PS, and the more incomplete the AnGS structure. The inhibition of Anammox by PET at small particle size was mainly associated with the granular sludge's lower Zeta potential and smaller specific surface area. In contrast, large-size PET-MPs reduced the chance of contact with MPs and provided more active sites, facilitating Anammox substrates' delivery efficiency. High-throughput sequencing results showed that the particle size of PET-MPs determined the diversity and abundance of microbial community, especially the relative abundance of Candidatus Kuenenia.
2023 Vol. 43 (12): 6406-6412 [Abstract] ( 132 ) [HTML 1KB] [ PDF 887KB] ( 1406 )
6413 Research progress on adsorption technologies for PFAS removal from water
WANG Tu, BAO Yi-xiang, ZHONG Jin-kui, LI Jing-feng, CAO Zhi-guo, WU Min
In this paper, the adsorption properties, mechanisms, influencing factors, advantages and potential problems of different adsorbents (activated carbon, resin, mineral materials, molecularly imprinted polymers, bio-based materials, etc.) for PFAS removal were summarized. Adsorbents with similar pore size to PFAS molecules, and with opposite surface charge had higher adsorption capacity to PFAS. Lower pH and higher temperature are more favorable for PFAS adsorption, and coexisting organic matter will compete with PFAS on adsorption. The adsorption performance of the adsorbent to PFAS was positively correlated with its chain length, and the adsorption capacity of the adsorbent to PFAS containing sulfonic group was higher than that of PFAS with carboxylic group at the same chain length. The main adsorption mechanisms include electrostatic attraction, hydrophobic interaction, ion exchange, ligand exchange, etc. The reasonable regeneration and disposal of adsorbents was a common problem in practical engineering applications, such as poor regeneration effect of chemical regeneration and biological regeneration, high energy consumption of thermal regeneration, easy to cause secondary pollution by solvent regeneration or landfill treatment. By reviewing the research progress of adsorption removal materials and technologies for PFAS from water, the advantages and disadvantages of different technologies are systematically expounded, and the research direction of adsorption removal technology is prospected, which could provide reference for PFAS pollution control in water.
2023 Vol. 43 (12): 6413-6434 [Abstract] ( 429 ) [HTML 1KB] [ PDF 730KB] ( 7083 )
6435 Magnetic flocculation of kaolin suspension using magnetic materials functionally regulated with plant polyphenols
LIU Chuang, DU Si-cong, CHENG Peng, LIANG Wen-yan
Plant polyphenol (PP) was used as a functional regulating ligand in preparation of Fe3O4@PP magnetic composite via in-situ self-assembly, which was applied in magnetic flocculation of kaolin suspension. The morphology of Fe3O4@PP was observed with SEM. The effects of Ca2+ ions, alkalinity, and humic acid concentration on flocculation performance of Fe3O4@PP were studied. The morphology and structural features of magnetic flocs during growth and breakage were observed using optical microscopy. The interaction mechanism between Fe3O4@PP and kaolin particles was investigated with the extended DLVO theory. The results showed that Fe3O4@PP had excellent dispersibility, chemical stability, and flocculation performance, which could overcome the interference of alkalinity and humic acid, achieving a maximum turbidity removal efficiency of 96.4%. During magnetic flocculation, magnetic flocs gradually became denser and formed long-chain aggregates with good resistance to breakage. The analysis of interaction energy indicated that magnetic force dominated the entire flocculation process. The total interaction potential and effective distance of magnetic force were three orders of magnitude higher than electrostatic and van der Waals forces. Furthermore, the total interaction energy was also affected by the properties of the suspension, such as pH value, Ca2+ ion concentration, and ion species.
2023 Vol. 43 (12): 6435-6444 [Abstract] ( 156 ) [HTML 1KB] [ PDF 1525KB] ( 952 )
Solid Waste
6445 Disposal methods and development tendencies of waste biodegradable plastics
HAN Shi-lei, ZHANG Fu-Shen
Biodegradable plastics have been widely applied in many fields in recent years. Waste biodegradable plastics (WBP) products may easily cause environmental pollution, thus the disposal and resource utilization of WBP are important guarantees for large-scale application of this type of plastics. This paper summarized the main disposal approaches of WBP, especially focused on mechanical recycling, chemical recycling, biological treatment, landfill, incineration and upgrade utilization. Furthermore, the problems encountered in the treatment process of WBP were systematically analyzed, and the future development trend of WBP recycling was predicted. The main purpose is, to provide guidance for the green and efficient treatment of WBP.
2023 Vol. 43 (12): 6445-6464 [Abstract] ( 129 ) [HTML 1KB] [ PDF 907KB] ( 3325 )
6465 Leaching risk and solidification mechanisms of electrolytic manganese residue pollutants based on the geopolymer system
LIU Bo, HE Li-li, YUE Bo, MENG Bang-bang, WANG Tao, GAO Hong
In order to mitigate the potential environmental risks associated with electrolytic manganese residue (EMR), a geological polymerization reaction was employed to carry out its solidification and stabilization. Through leaching toxicity tests and consecutive BCR extraction experiments, the leaching risk of electrolytic manganese residue-based polymer (EMRGP) was ascertained. Characterization techniques such as XRF, XRD, SEM-EDX, and XPS were utilized to investigate the solidification mechanism. The results revealed that the concentrations of Mn2+ and NH4+ in the leachate from EMRGP were merely 4.64μg/L and 0.99mg/L, meeting the standards for discharge and reutilization. BCR continuous extraction experiments showed a lower leaching risk for EMRGP. During the solidification and stabilization process, the formation of silica-alumina gel occurred. NH4+ either volatilized as NH3 or precipitated as struvite, while Mn2+, apart from being oxidized to Mn3+ and Mn4+, concomitantly precipitating with other heavy metal species in the guise of hydroxide precipitates or enshrouded within the protective vestiges of silico-aluminous gels. This approach significantly alleviated the potential environmental risk associated with EMR.
2023 Vol. 43 (12): 6465-6473 [Abstract] ( 160 ) [HTML 1KB] [ PDF 1595KB] ( 1230 )
Soil Pollution Control
6474 Research on the efficiency of surfactant leaching coupled with chemical oxidation on high rings polycyclic aromatic hydrocarbons removal from coking contaminated soil
Li Wei, Wang Hua-wei, Meng Xiang-yu, Yang Yue-wei, DING Hao-ran, Li Shu-peng, Liu Yuan-wen, Sun Ying-jie, Liu Peng, Wang Ya-nan
In order to explore the remediation efficiency of surfactant leaching combined with chemical oxidation technology on the treatment of organic polluted soil in coking sites, the polycyclic aromatic hydrocarbons (PAHs) contaminated soil in a coking site in Anhui Province was taken as the experimental object, and the effect of process parameters such as surfactant concentration, liquid-solid ratio, leaching time and number of leaching on the leaching efficiency was analyzed. On the basis of optimizing the process parameters, the efficiency of chemical oxidation on the removal of PAHs was further investigated. The results showed that: 1) Tween 80 (TW80) was more effective than Triton and rhamnolipid in leaching PAHs from soil, which was used for subsequent experiments; 2) The removal efficiency of ΣPAHs was 43.5% when the concentration of TW80was 6g/L, the liquid-solid ratio was 10:1and the leaching time was 4h; 3) Multiple leaching was helpful for improving the leaching efficiency of PAHs, and the leaching efficiencies of ΣPAHs were 63.3% and 72.1% after three and five times leaching, respectively; 4) The removal efficiency of ΣPAHs increased to 79.4% after TW80 leaching five times combined with the oxidation of 10% H2O2, while the ΣPAHs removal efficiency increased to 81.2% after oxidation treatment with 10% KMnO4, in which the benzo[a]pyrene removal efficiency was 98.3%; 5) After TW80 leaching treatment, the combination of H2O2 or KMnO4 oxidation treatment can improve the removal efficiency of PAHs, the content of benzo[a]pyrene was 0.39mg/kg and 0.46mg/kg after five times leaching combined with 1% H2O2 and three times leaching combined with 1% KMnO4, respectively, which can met the screening value requirement of soil environmental quality risk control standard for soil contamination of development land (GB36600-2018); 6) The combination of surfactant leaching with chemical oxidation technology has a good efficiency on PAHs removal. This technology has a potential application prospect on the remediation of PAHs contaminated soil.
2023 Vol. 43 (12): 6474-6481 [Abstract] ( 150 ) [HTML 1KB] [ PDF 1358KB] ( 1250 )
6482 Soil-microbe characterization and interaction in alpine degraded grassland in Maqu county
WANG Min, LIU Min-xia, WANG Qian-yue, MIAO Le-le, YANG Chun-liang, XIAOYin-di
In this paper, four kinds of alpine grassland with different degradation levels in Maqu county, Gannan Tibetan Autonomous Prefecture, Gansu Province, were used as the research objects, and soil physicochemical factors and soil microbial community characteristics were measured and analyzed. The results showed that the soil water content, soil organic carbon, total nitrogen, and total phosphorus decreased significantly (P<0.05) with increased grassland degradation. In contrast, the trends of soil pH and soil electrical conductivity were opposite. Through high-throughput sequencing, we analyzed and obtained the numbers of bacterial and fungal OTUs in no, light, moderate, and severely degraded grassland were 1927, 2011, 2040, 1798 and 1492, 1511, 1383, 1466; the numbers of bacterial and fungal OTUs specific to no, light, moderate and severely degraded grassland were 588, 513, 691, 409 and 116, 112, 73, 79. The number of soil microbial community bacteria dominated significantly, and the diversity decreased with the degradation of grassland as a whole. The relative abundance of the dominant group of soil bacteria, Proteobacteria, reached a maximum of 45% in the moderately degraded grassland; the relative abundance of the dominant group of soil fungi, Ascomycota, reached a maximum of 89% in the non-degraded grassland. Through RDA analysis, it was obtained that soil electrical conductivity, organic carbon, water content, total nitrogen, total phosphorus and pH were the main influence factors of soil bacteria, and soil total phosphorus, total nitrogen, and organic carbon were the main influence factors of soil fungi.
2023 Vol. 43 (12): 6482-6489 [Abstract] ( 141 ) [HTML 1KB] [ PDF 1745KB] ( 1032 )
6490 Comprehensive risk assessment of key supervision units of soil pollution in Yangtze River Delta
JU Tie-nan, LEI Mei, GUO Guang-hui, XU Yuan, LOU Qi-jia, ZHANG Yang, ZHANG Jin-long
To evaluate the comprehensive risk of key regulatory units of soil pollution in the Yangtze River Delta, based on the risk assessment concept of "source pathway receptor", this paper innovatively integrated the "pathway" into the simulation method of potential pollution scope of the site for key industry enterprises over 50 years of history according to the production information of enterprises and years of natural environment information and evaluates the vulnerability of receptors and site hazards in the Yangtze River Delta according to the pollution scope. On this basis, this study compared the change of the receptor index of relocation enterprises before and after production and closure to evaluate the effect of environmental protection policy control. Finally, based on the site hazards and the vulnerability of peripheral receptors within the pollution range of the production enterprises, we constructed the risk classification at the county scale in the Yangtze River Delta and proposed priority control of county units. The results show that the chemical industry and electroplating industry are the pillar industries of the Yangtze River Delta, accounting for more than 85%, mainly distributed in the eastern region. By 2020, implementing environmental protection policies has effectively safeguarded environmental protection policies that more than 17 million people and protected approximately 23000km2 of agricultural land in the Yangtze River Delta from higher risks, reducing potential pollution by 42%. The study identified eight high-risk counties as priority control areas in the Yangtze River Delta in 2020, including Pudong New Area, Fuyang District, Jiading District, Zhangjiagang City, and Xiaoshan District.
2023 Vol. 43 (12): 6490-6499 [Abstract] ( 173 ) [HTML 1KB] [ PDF 2529KB] ( 1305 )
6500 Characteristics of heavy metal content and pollution risk assessment in the soil of typical Emeishan Basalt Area
HAN Wei, XU Ren-ting, WANG Qiao-lin
To investigate the extent of the influence of Emeishan basalt on soil heavy metal content, the study focused on Zhaotong in Yunnan Province, which is located in a typical distribution area of Emeishan basalt. By combining geological data, the characteristics, pollution risk, and sources of eight heavy metal elements in 7104 soil samples within the region were analyzed and evaluated. The results showed that the surface soil in the Emeishan basalt area is significantly enriched in Cu and Cd, reaching 7.20 and 6.63 times the background values of Chinese soil, respectively. Compared to the risk control standard for soil contamination of agricultural land, except for Hg, the other seven heavy metal elements posed a pollution risk. In terms of spatial distribution of pollution level, Cu, Cd, As, Pb, and Zn were closely associated with the natural source, with Cd and Cu being the highly contaminated heavy metal elements. PCA indicated that Cu mainly originated from the geological parent materials of Emeishan basalt, while Cr and Ni were associated with weathering of coexisting ultrabasic rocks with Emeishan basalt. Cd, Pb, and Zn at high concentrations primarily resulted from human mining activities and vehicle exhaust emissions, as well as being influenced by the geological background. As and Hg were influenced not only by parent material and human activities but also by soil physicochemical properties and organic matter.
2023 Vol. 43 (12): 6500-6508 [Abstract] ( 145 ) [HTML 1KB] [ PDF 2737KB] ( 773 )
6509 Flushing and separating effects for nitrobenzene contaminated soil by a redox-switchable surfactant
GENG Fei, YAO Yu, FU Yu-feng, ZHANG Hui, QIN Chuan-yu, REN Li-ming
A redox-switchable surfactant, 11-ferrocene undecanoyl trimethylammonium bromide (FcCOC10N), was synthesized in this study, achieving the “on” and “off” of its surface activity through the oxidation and reduction state transition of the ferrocene groups. The aim was to facilitate the separation and recovery of the surfactant while improving the remediation of polluted soil by organic contaminates through soil flushing technique. The differences in physical and chemical properties of FcCOC10N before and after the redox reaction indicated its good redox-reversible characteristics. The FcCOC10N solution and nitrobenzene were easily emulsified into an emulsion with small and uniform droplets, which was immediately demulsified and separated with the addition of an oxidant. Moreover, no change was observed for the properties of the emulsion formed by FcCOC10N and nitrobenzene after repeated 5switches, with a demulsification efficiency of > 80%, demonstrating a good emulsification and demulsification cyclic capability between FcCOC10N and nitrobenzene. Flushing of nitrobenzene-contaminated soil was conducted to remove the non-aqueous phase pollutants from the soil via emulsification, with the highest emulsification removal efficiency of 92.40%. Residual nitrobenzene in the soil was further removed through demulsification and separation of nitrobenzene and recycling of FcCOC10N, with a final removal efficiency of 94.70%.
2023 Vol. 43 (12): 6509-6517 [Abstract] ( 138 ) [HTML 1KB] [ PDF 3344KB] ( 961 )
Environmental Ecology
6518 Research on the shift change of vegetation greenness line in the Loess Plateau based on GEE
XIE Pei-jun, SONG Xiao-yan, SUN Wen-yi, MU Xing-min, GAO Peng
The temporal and spatial evolution patterns of the vegetation greenness index and its spatial distribution in the Loess Plateau hold significant scientific importance in gaining comprehensive insights into the dynamic changes of vegetation and assessing the effectiveness of ecological restoration. Although previous studies have explored the factors influencing spatiotemporal variations in vegetation greenness, the limited spatial resolution of remote sensing products poses challenges in capturing fine-scale characteristics and dynamic shifts in vegetation greenness lines. In the study, the Google Earth Engine (GEE) cloud platform, combined with a series of Landsat remote sensing images, is used to calculate the Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), along with their Vegetation Greenness Lines, as indicators to characterize the spatiotemporal evolution of vegetation greenness during the growing season on the Loess Plateau from 1987 to 2020. The results show that the annual average growth rates of NDVI and EVI in the Loess Plateau were 0.0042a-1 (P<0.01) and 0.0023a-1 (P<0.01) from 1987 to 2020, respectively. Notable, the average growth rates after the year 2000 were approximately three to four times higher than those observed before 2000. In terms of spatial distribution, the trends in NDVI and EVI predominantly exhibited significant and highly significant increases, with respective area percentages of 78.78% and 69.21%. Over the period from 1987 to 2020, the vegetation greenness lines VGLNDVI and VGLEVI exhibited a northward movement in the Loess Plateau at rates of 5.52 and 4.59 km/year, respectively. Over the same period, the average northward movements for VGLNDVI and VGLEVI were 173.93km and 131.62km, respectively. The most significant northward shift was primarily observed between 2005 and 2010, with the largest movement of the VGLNDVI and VGLEVI occurring in the Yulin and Yan'an areas of Shaanxi Province, northwest Shanxi Province, and central and southern Inner Mongolia, reaching maximum distances of 532.12km and 471.57km, respectively.
2023 Vol. 43 (12): 6518-6529 [Abstract] ( 146 ) [HTML 1KB] [ PDF 6968KB] ( 820 )
6530 The aging behavior of degradable plastic PBAT under the interaction of environmental factors
JIANG Hui, ZHU Li-fan, YANG Chao, LIU Xiu-li, LIU Xin, SUN Jiao-xia
In order to study the aging behavior of degradable plastics under the interaction of different environmental factors, poly (butyleneadipate-co-terephthalate) (PBAT) was used as the target. The aging process and potential mechanism of PBAT under the interaction of different factors were investigated by setting uniform and interactive experiments with temperature, humidity and light as factors. The results of multi-factor interaction experiments combined with scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) showed that humidity had the greatest influence on the aging behavior of PBAT, and temperature had the least influence on the aging behavior of PBAT. The aging effect was the most obvious under the conditions of temperature 30.0 °C, humidity 60% and ultraviolet light. The changes of chemical bonds and crystallinity of PBAT during different aging processes were further analyzed by X-ray spectroscopy (XPS) and X-ray diffraction (XRD). The results showed that under the interaction of humidity and ultraviolet light, the carbon-oxygen double bond of PBAT decreased and the carbon-oxygen single bond increased. The carbon-oxygen double bond was destroyed to form a carboxyl group. The oxygen atoms in some functional groups replaced the hydrogen atoms, and the behavior of gain and loss of electrons appeared. The small molecule CO2 and π-π bonds were formed on the surface; in this interactive aging process, the crystallinity of PBAT increased.
2023 Vol. 43 (12): 6530-6538 [Abstract] ( 129 ) [HTML 1KB] [ PDF 2002KB] ( 967 )
6539 Analysis of nitrogen and phosphorus emissions from agricultural non-point sources based on improved output coefficient method
GOU Ting, PEI De-fu, LIANG Rong-chang, SHE Lei, YANG Jun, MA Qian-li, ZHAO Xue-min, ZHAO Rui, YAO Ling-ai
To study the nitrogen and phosphorus loadings from agricultural surface sources in the source area of Dongjiang River, the characteristics of nitrogen and phosphorus emissions from agricultural surface sources in the source area of Dongjiang River in 2020 were explored using an improved output coefficient model (ECM). The results show that: (1) the loads of total nitrogen (TN) and total phosphorus (TP) of agricultural surface source pollutants in the source area of Dongjiang River were 4884.23t/a and 591.85t/a, respectively, and the TN pollution load was 8.25 times of the TP pollution load. Among the townships with higher than the average TN load were Liuche Township, Wenfeng Township, Chenguang Township, Nanqiao Township, Jitan Township, Danxi Township and Chengjiang Township, higher than the TP average load of the township were Chenguang, Liuche Township, Nanqiao Township, Wenfeng Township, Danxi Township, Calamus Township and Jitan Township. (2) Nitrogen and phosphorus pollution load intensity and load amount was different, and showed spatial variability. The higher pollution load was Liuche Township and Chenguang Township respectively, but the highest load intensity was Nanqiao Township and Calamus Township respectively. The higher TN load intensity was in the order of Nanqiao Township, Calamus Township, Chenguang Township, Liuche Township and Xiangshan Township, which all higher than the average TN load intensity of 2.88t/(km2×a) in the source area; the higher TP load intensity was in the order of Calamus Township, Nanqiao Township, Chenguang Township, Danxi Township, Liuche Township and Luoshan Township, which all higher than the source area TP average load intensity of 0.36t/(km2×a). (3) The contribution of different source types to nitrogen and phosphorus emissions was not consistent, TN pollution was manifested as land use > rural life > livestock breeding, TP pollution was manifested as livestock breeding > land use > rural life. Among the nitrogen sources, land use pollution accounted for 37.67%~80.29%, mainly distributed in Changning Township, Guizhumat Township, Sanbiao Township, Water Source Township, Wenfeng Township; phosphorus sources of livestock breeding pollution accounted for 44.75%~70.71%, mainly distributed in Calamus Township, Chenguang Township, Luoshan Township, Nanqiao Township, Danxi Township, Longting Township and Liuche Township. Based on different characteristics of nitrogen and phosphorus non-point source pollution in the source area of Dongjiang River, the treatment methods were also different. For the townships were seriously polluted by livestock breeding, which should to solve the problems of poor planning of livestock breeding, unreasonable site selection and low level of resource utilization. The townships were seriously polluted by rural living pollution which should vigorously promote the construction of small rural sewage treatment facilities and improve the living sewage treatment measures. Other townships need to develop a reasonable fertilizer application program to avoid excessive application of chemical fertilizers. This study has important practical significance for improving the continuous emission reduction of agricultural non-point source pollution and ensuring the safety of water supply in Dongjiang River.
2023 Vol. 43 (12): 6539-6550 [Abstract] ( 137 ) [HTML 1KB] [ PDF 2279KB] ( 1392 )
6551 Estimation of nitrogen and phosphorus pollution loads from non-point sources in farmland of Hetao Irrigation District, Inner Mongolia
WANG Yan, JIAO Yan, YANG Wen-zhu, YAN Ying-chao, WU Hong, LING Ling, SHI Yue-chao
To understand the current situation of farmland non-point source pollution in the Hetao irrigation district of Inner Mongolia, the traditional export coefficient model (ECM) was improved, and the farmland non-point source nitrogen and phosphorus pollution load was quantified by precipitation impact factor (α) and terrain impact factor (β) in the area. The farmland non-point source nitrogen and phosphorus discharged into the river (Wuliangsuhai) was estimated, and the critical source areas of pollution was identified by the pollution river influx coefficient (γ). The total export load of non-point source total nitrogen (TN) and total phosphorus (TP) from farmland were 3520.998 and 407.125t in the Hetao irrigation district in 2021, accounting for 79.674% and 89.201% of the total pollution load from different land use types, respectively. The spatial distribution of the export loads for TN and TP of farmland non-point sources was consistent, and the contribution in towns near drainage was the highest. The export loads of TN and TP pollution were 316.658, 236.725, 199.344t/a and 36.615, 27.371, 23.050t/a in Xinhua, Xin'an and Talhu township, respectively. The amount of TN and TP discharged into the river were 387.310 and 16.285t/a from non-point sources of farmland. The towns of Xinhua, Xin'an, Talhu, Longxingchang, Tuanjie and Manhui were key areas for pollution prevention and control in the Hetao irrigation district. The rationality of the improved export coefficient model with relative errors of -4.743% and 19.037% had been verified by comparing with measured values.
2023 Vol. 43 (12): 6551-6560 [Abstract] ( 162 ) [HTML 1KB] [ PDF 2863KB] ( 1412 )
6561 Analysis of the driving forces of vegetation dynamic changes in southwest China
ZENG Xing-lan, CHEN Tian-tian
Based on the Normalized Difference Vegetation Index (NDVI), land use and climate datasets, this study analyzed the trend of change in vegetation growth and clarified the impact of climate change and urban expansion on vegetation dynamics in southwest China by the ensemble empirical mode decomposition, partial correlation analysis and segmented linear regression. The results showed that the NDVI in the southwest China fluctuating increased, indicating an obvious vegetation greening trend; spatially, the regions with high NDVI were distribution in the southeast part and the regions with low NDVI were concentrated at the northwest part. Compared to the solar radiation and precipitation, the influencing scale and degree of temperature on regional vegetation growth was relatively large, accounting for approximately 64.6% of the study area, mainly distributed in the central and western parts of the study area. The land urbanization, economy urbanization and demographic urbanization increased over time, and the spatial distribution of these three urbanizations was relatively consistent. At the county scale, the correlation between economic urbanization, demographic urbanization and vegetation growth increased firstly and then decreased, showing a nonlinear characteristic; while there was a negative correlation between land urbanization and vegetation growth. At the grid scale, the relationship between these three urbanization and vegetation growth remains unchanged; but there were significant differences in the thresholds of nonlinear relationship and the slope of linear relationship. This study can provide scientific reference for implementing more precise ecological management measures and achieving sustainable socio-economic development in this region.
2023 Vol. 43 (12): 6561-6570 [Abstract] ( 213 ) [HTML 1KB] [ PDF 5283KB] ( 1419 )
6571 Identification and restoration zoning of key areas for ecological restoration of territorial space in southwestern karst mountainous areas: A case study of Kaiyuan City in karst mountainous area of Southwest China
XIANG Ai-meng, YUE Qi-fa, ZHAO Xiao-qing, HUANG Pei, RAN Yu-ju, GU Ze-xian, SHI Xin-yu
Taking Kaiyuan City as an example, this paper has constructed the ecological security pattern and identified the key areas of ecological restoration from the perspective of ecosystem services and ecological vulnerability. The ecological problem index was used to quantify the existing ecological problems in the key areas of ecological restoration, and the ecological restoration zoning was delineated and the corresponding restoration strategies were proposed. The research showed that: (1) The ecological security pattern of Kaiyuan City consisted of two sources and two types of corridors. The area of ecological protection source and ecological restoration source was 190.53km2 and 16.82km2 respectively, and the total length of potential ecological corridor and restoration corridor was 191.15km and 75.71km respectively. (2) Based on the ecological security pattern, the key areas of ecological restoration in Kaiyuan City were extracted, including 15 ecological restoration sources, 12 ecological restoration corridors, 31 ecological pinch points and 11 ecological obstacle areas. The rocky desertification in the key areas of ecological restoration was mainly concentrated in the west and south of Kaiyuan city, and the degree of rocky desertification in the west was higher than that in the south. Soil erosion was mainly micro-erosion; geological disasters occured frequently in mining areas and karst landform areas; ecological risks were high; human disturbance was concentrated in the northwest-southeast line. (3) According to the calculation results of ecological problem index, the key areas of ecological restoration were divided into ecological conservation areas, functional improvement areas, disaster prevention areas and key remediation areas, and corresponding optimization strategies were proposed in combination with the prominent ecological problems in each area. The research results could provide some reference for the identification and restoration strategy of key areas of territorial space ecological restoration.
2023 Vol. 43 (12): 6571-6582 [Abstract] ( 114 ) [HTML 1KB] [ PDF 5103KB] ( 1371 )
6583 The key driving factors of land use patio-temporal change and its influence trend——A case study of Wuwei
WANG Xing-dan, LIU Pu-xing, GENG Meng-die, WANG Miao, LU Juan
Based on the Landsat TM/OLI remote sensing image data of Wuwei City in 1990, 2000, 2010 and 2021, this paper used the methods of land use dynamic change index, land use transfer matrix, center of gravity migration model and principal component comprehensive score model, combined with meteorological data and socio- economic statistical data, the spatio-temporal driving factors of land use change in Wuwei City were quantitatively analysed. The results show that: In the past 32 years, the area of Grassland, Cropland, Impervious and Water in Wuwei City showed an increasing trend, while the area of Barren and Forest showed a decreasing trend, and the dynamic rate ranged from 2.56% to -0.13%. Forest and Barren were mainly converted to Grassland and Cropland; The spatial difference of land use change in the study area was obvious. The center of gravity migration distance of Water was the largest, followed by Cropland and Barren was the least; Human activities and climate change were the key factors affecting land use change in Wuwei City. The contribution rate of human activities was 56.35%, which was much higher than that of climate change in 43.65%, and the impacts of both showed an upward trend, and the influence trend of human activities was greater than that of climate change. In the future, we should give full play to the positive role of human beings, so as to promote the coordinated development of human and land.
2023 Vol. 43 (12): 6583-6591 [Abstract] ( 207 ) [HTML 1KB] [ PDF 4152KB] ( 778 )
6592 Accuracy of environmental flows time history reconstruction model based on sparse observation
ZHAN Qing-liang, LIU Xin, CHAO Yang, GE Yao-jun
Obtaining more environmental flow data at more monitoring sites based on limited and sparse available flow monitoring points can provide data for the study of atmospheric monitoring, water monitoring and pollutant dispersion issues. In this study, the influence of physical constraints on the accuracy of the machine learning flow field time history representation model was investigated, and the results of different available measurement points and physical constraint influence weights were compared. The environmental flow around a low Reynolds number square column was tested as an example. Results show that when the number of monitoring points was increased to 500, the accuracy did not improve. When the number of monitoring points was reduced to only 50, the error was minimised when the physical constraint weights were set to 10. The results indicate that the problem of less available data can be effectively compensated by choosing appropriate physical constraint influence weights. Providing a new method and basis for data processing and high-resolution flow field reconstruction for environmental flow problems.
2023 Vol. 43 (12): 6592-6600 [Abstract] ( 143 ) [HTML 1KB] [ PDF 8876KB] ( 952 )
6601 Influence of extreme drought in 2022 on groundwater hydrological regime in the Poyang Lake floodplain area
CAO Si-jia, LI Yun-liang, CHEN Jing, YAO Jing, ZHAO Gui-zhang, LI Zhi-ping
The recognition and attention of groundwater in the river-lake system was done gradually strengthened. The current research used the floodplain area of Poyang Lake as our study area. We further used the FEFLOW groundwater flow model to quantitatively evaluate the spatiotemporal responses of floodplain groundwater under the extreme drought condition in 2022. The simulation results showed that the continuous impact of extreme drought on Poyang Lake in 2022 mainly occurs in the second half of the year. The extreme droughtleaded to a significant decrease of floodplain groundwater level and an overall acceleration of groundwater flow velocity in the lake’s floodplain. The decreasing trends of both the groundwater level and flow velocity exhibited an obvious spatial heterogeneity. In general, the maximum drop of groundwater levels affected by the extreme drought reaches about 5m, and the groundwater flow velocity was about once-twice than that of the normal year. In addition, extreme drought might result in a significant decline in rainfall recharge and a significant increase in groundwater discharge (into the lake), contributed to the decline of floodplain groundwater storage. On an annual scale, the extreme drought might lead to increasing groundwater discharge of 16.2×106m3 in the study area, which was about 14.5 times than that of groundwater discharge in the normal year. Poyang Lake and its floodplain are important drainage and ecological barrier areas of the whole basin groundwater flow system, and therefore, this study highlights the importance of lake and groundwater hydrological responses.
2023 Vol. 43 (12): 6601-6610 [Abstract] ( 210 ) [HTML 1KB] [ PDF 2148KB] ( 1048 )
Carbon Emission Control
6611 The spatial effect and action mechanism of the influence of rural land transfer on agricultural carbon emission intensity
JI Xue-qiang, CUI Yi-lin, ZHANG Si-yang, SUN Hong-yu, YUAN Dong-ming, ZHANG Yue-song
Agricultural carbon emission intensity has important practical value considering agricultural production level and agricultural green development. Analysis of the impact of rural land transfer on agricultural carbon emission intensity has scientific value for promoting carbon emission reduction in the process of rural land transfer promotion, but few existing studies have analyzed its spatial effects. After theoretical analysis, based on the panel data of 30 provinces in China’s mainland from 2005 to 2021, the panel regression model was used to analyze the impact of rural land transfer on agricultural carbon emission intensity. The spatial effects of rural land transfer on agricultural carbon emission intensity were discussed by combining the spatial econometric model. The results showed that during the study period, rural land transfer a significant negative spatial effect on agricultural carbon intensity. Rural land transfer can not only reduce the agricultural carbon intensity in the local area, but also reduce the agricultural carbon intensity in the surrounding area, and its spatial spillover effect is more obvious; Technology development mechanism, demonstration effect mechanism and regional competition mechanism are the key mechanisms of the negative spatial spillover effect on agricultural carbon emission intensity. The spatial effect of rural land transfer on agricultural carbon emission intensity has regional heterogeneity, and the spatial carbon emission reduction effect of rural land transfer in southern China is deeper than that in northern China. Therefore, it is suggested to speed up rural land transfer and give full play to the spatial emission reduction effect of rural land transfer in various ways.
2023 Vol. 43 (12): 6611-6624 [Abstract] ( 186 ) [HTML 1KB] [ PDF 708KB] ( 1292 )
6625 Research on the effect of digital economy on carbon emissions from household consumption
BAN Nan-nan, ZHANG Xiao-yue
Using panel data from 30 provinces and regions in China between 2000 and 2020, this study comprehensively measured the carbon emissions of household consumption and digital economy development index under different levels of demand. By employing a spatial econometric model, we studied the decomposition spatial effect and analyzed the threshold effect of digital economy and overall consumption carbon emissions to investigate the impact of digital economy on carbon emissions from household consumption. The study showed that: (1) the carbon emissions from household consumption in China increased overall, with a trend of high (low) emission in eastern (western) China and concentration in the middle and eastern China. (2) Direct carbon emissions were the main source of carbon emissions from household consumption; but with the development of society, its proportion in the total consumption carbon emissions was declining, while the proportion of indirect emissions were increasing. (3) The development of digital economy could significantly increase indirect carbon emissions from household consumption both in local and its neighboring provinces, and local indirect carbon emissions for survival. However, an "inverted U" relationship was found between the degree of development of digital economy and the overall consumption carbon emissions, and digital economy could promote household consumption carbon emission reduction after reaching a higher level of development. Therefore, it was suggested to further promote the development of the digital economy and strengthen guidance on green production and life, so as to help achieve the "dual carbon" goal.
2023 Vol. 43 (12): 6625-6640 [Abstract] ( 138 ) [HTML 1KB] [ PDF 1205KB] ( 1207 )
6641 Enhancement and mechanism of algal-derived organic matter deposition on lake sediment methane release
ZHANG Nan, HE Kai, ZHONG Ji-cheng, AN Yan-fei, YUAN He-zhong, ZHANG Lei
Lakes are important natural sources of methane (CH4) release. A well-known view is that frequent cyanobacterial blooms promote CH4 release in freshwater lakes, but the specific driving process and mechanism are still unclear. In this study, the driving process and effect of algal-derived organic matter deposition on CH4 release were simulated and studied by using water and sediment samples from Lake Chaohu. The results showed that the CH4 release flux in the group with the treatment of additional added algae was (1.59±0.51)~(98.89±14.30) μmol/(m2·h)) significantly higher than that in the control group (0.02±0.016)~(1.37±0.44) μmol/(m2·h)) (P<0.001). During the simulating experiment, the degradation of algal-derived organic matter provided a large number of substrates for methane production while the reduction of electron acceptors such as dissolved oxygen and sulfate created an environment conducive to methanogens, which resulted in a massive proliferation of methanogens, especially acetic acid trophic methanogens. Our study clearly demonstrated that the large input of algal-derived organic matter increased the methane production rate and methane release flux of lake sediments with acetic acid trophic methanogens playing an important role.
2023 Vol. 43 (12): 6641-6650 [Abstract] ( 171 ) [HTML 1KB] [ PDF 937KB] ( 1056 )
6651 Carbon emissions of municipal sludge "deep dehydration-drying-incineration" processes under different sludge preconditioning methods
')" href="#"> MA Jian-yun, LI Zhi, GU Jun, WANG Fei, HOU Bao-lian, YU Ran
This study developed pilot-scale "deep dehydration-drying-incineration" processes for sludge treatment and disposal with two different preconditioning approaches, i.e., novel sludge biolysis and the conventional chemical agent (iron salt + lime). Then, the carbon emission characteristics of these approaches were analysed and compared according to methods by Intergovernmental Panel on Climate Change (IPCC). The results showed that the moisture contents of dewatered sludge with the plate and frame filter press were both less than 60% no matter which preconditioning method was applied. However, the dry matter contents and the dry basis calorific values of the filter pressed sludges were significantly different. Specifically, the biolysed sludge showed 23.0 % lower dry matter content and 32.1% higher dry basis calorific value as compared with that treated with chemical preconditioning. Based on one cubic meter of raw sludge (RS) with 98% water content, and the total carbon emissions of the sludge "deep dehydration-drying-incineration" process for sludge treatment and disposal with biolysis as pretreatment was 15.8kg CO2eq/m3 RS, which was 41.7% lower than that with the chemical preconditioning process (27.1kg CO2eq/m3 RS).
2023 Vol. 43 (12): 6651-6656 [Abstract] ( 159 ) [HTML 1KB] [ PDF 502KB] ( 1796 )
6657 Investigation into the carbon footprints of modern timber buildings based on life cycle assessment
SU Peng-yu, YAO En-ming, LI Zheng
This paper researched the building life cycle carbon footprint based on a representative modern timber building in China, and a method of splitting the carbon emission of negative carbon building materials into the carbon emission of the production process and the biological carbon sequestration value was proposed. The results showed that the carbon emissions of the life cycle of the modern timber office building were 1.69×107kgCO2e, in which the product stage accounted for 15.56%, the use stage accounted for 84.34%, and the end-of-life stage accounted for 0.10%. The carbon emission in the product stage of timber building was lower than that of traditional reinforced concrete or steel buildings.
2023 Vol. 43 (12): 6657-6666 [Abstract] ( 158 ) [HTML 1KB] [ PDF 1620KB] ( 1396 )
6667 Variation characteristics and correlation of soil and stream carbon dioxide concentrations in a headwater catchment
LI Jia-qi, JIANG Zhen-jiao, DAI Xin, WANG Chuan, WU Li-wen, XIE Yue-qing
With the objective to characterize CO2 dynamics from soil to streams, and to identify relevant influential factors along with temporal evolution patterns, this study established a high-frequency CO2 concentration monitoring transect with four measuring points in a stream and adjacent soil located in the upper reach of the Hailiutu River Basin in Yulin city, Shannxi province. With the spectrum and wavelet analysis, strong diurnal signals with periods of 0.5 and 1d frequencies are identified based on the CO2 concentration time series, indicating that the diurnal stream metabolism plays a key role in regulating in-stream CO2 dynamics. Additionally, variations in hydrological events, i.e. precipitation in the catchment, may lead to prominent changes in CO2 evasion, which has a significant impact on the carbon cycling between stream and soil. Bivariate wavelet coherence analysis reveals that temperature and soil water content directly control stream and soil CO2 dynamics, and confirms that soil-stored CO2 is the main source of the stream CO2 evasion. Further, the results indicate that groundwater is an important pathway for carbon transport from soil to streams.
2023 Vol. 43 (12): 6667-6676 [Abstract] ( 144 ) [HTML 1KB] [ PDF 3837KB] ( 1056 )
6677 Analyzing carbon emissions in the Yangtze River Delta's construction industry: Spatiotemporal characteristics and influencing factors
LIU Ying, WANG Yuan, ZHU Lin
The carbon emissions of the construction sector in the Yangtze River Delta region were calculated using the carbon emission coefficient method in this paper. The spatial variations, evolutionary characteristics, and driving factors of carbon emissions across 26 cities in the Yangtze River Delta were analyzed using the slope index, Theil index, and Logarithmic Mean Divisia Index (LMDI). The results indicated that between 2004 and 2020, the carbon emissions from the construction industry in the Yangtze River Delta were first increased and then exhibited a wave-like fluctuation, overall presenting a high-in-the-east and low-in-the-west spatial pattern. The overall disparity in carbon emissions within the construction sector of the Yangtze River Delta was diminished, first showing a wave-like increase and then a gradual decline. Notably, within the Yangtze River Delta region, the intra-provincial discrepancies contributed more to the overall variance than the inter-provincial discrepancies. Among the driving factors, the effects of economic development and housing construction area promoted the increase in carbon emissions, while factors such as population density, energy consumption intensity, and energy structure intensity played a suppressing role.
2023 Vol. 43 (12): 6677-6688 [Abstract] ( 145 ) [HTML 1KB] [ PDF 2498KB] ( 1428 )
Emerging Contaminants
6689 Effect of stimulated warming on phyllosphere antibiotic resistance genes of Schima superba
LIN Xiao-ru, LI Zi-xin, SUN An-qi, JIN Sheng-sheng, XU Chao-die, CHEN Shi-dong, LIU Xiao-fei, SHEN Ju-pei
To understand the effect of warming on the distribution and seasonal dynamics of antibiotic resistance genes (ARGs) in the phyllosphere, we conducted a study involving collection of foliar samples from natural forest leaves during summer, autumn and winter from two treatments: control and warming (+4℃). The numbers and relative abundance of ARGs in the phyllosphere were determined by high-throughput quantitative PCR. Results showed that a total of 255 ARGs and 10 MGEs were detected in all phyllosphere samples, among which multidrug resistance was the dominant gene type in the phyllosphere, accounting for 47.4% of the total. The antibiotic efflux pump was the main resistance mechanism. ANOVA analysis and principal coordinate analysis showed that season significantly influenced the distribution of phyllosphere ARGs. The relative abundance of phyllosphere ARGs in autumn and winter was (0.614 ± 0.303)copies/16S rRNA and (0.589 ± 0.218)copies/16S rRNA, respectively, which was higher than that in summer ((0.291 ± 0.101)copies/16S rRNA), and the diversity of ARGs in autumn and winter was also higher than that in summer. We found that the relative abundance of seven ARGs(aadA2-03, acrA-02, emrD, matA/mel, tetB-01, tetM-01, tetL-02) decreased significantly (P<0.05), while the relative abundance of the acrA-01 gene increased significantly (P<0.05) in the warming treatment. Redundancy analysis and structural equation modeling showed that seasonality was the main factor driving the composition of phyllosphere ARGs via mediating soil physicochemical properties, while warming had no significant effect.
2023 Vol. 43 (12): 6689-6699 [Abstract] ( 119 ) [HTML 1KB] [ PDF 1368KB] ( 1269 )
6700 Characterization and source analysis of microplastics in urban rivers based on Laser Direct Infrared Imaging
LIU Sha-sha, QIU Yue, ZHANG Xi, SUO Cheng-yu, REN Yi
Taking Tonghui River, a typical urban river in Beijing, as an example, the occurrence characteristics, potential sources and ecological risks of microplastics in urban rivers were systematically studied based on laser infrared imaging system. The results showed that the abundance of microplastics in the surface water of the river ranged from 10 to 41pieces/L, with a mean value of (21.60±10.5) pieces/L. Additionally, a total of 16different types of microplastics were detected in our study, among which the three types with high abundance were polyamide (PA), polyvinyl chloride (PVC) and polybutylene succinate (PBS), with the detection rates of 25.90%, 22.20% and 18.10%, respectively. Moreover, fine microplastics with particle size £200μm dominated in the river, which accounted for 91.20% of the total number of particles. In terms of microplastic shape, film accounted for the largest proportion (67.59%), followed by granules (22.69%) and fiber (9.72%). Finally, according to the results of field investigation and microplastic characterization, we proposed that microplastics in the Tonghui River probably originated from the weathering of domestic garbage on the shore, the aging of sewage pipelines, and the residues in the effluent of sewage treatment plants. The results of risk assessment showed that the potential ecological risk index of microplastics in the lower reaches of Tonghui River was at dangerous and very dangerous levels, and PVC microplastics were the main types of plastics that caused the increased risk of the water ecosystem in the river. Thus, it is recommended that the government strengthen the source control of man-made plastics, especially PVC plastics, to provide support for the ecological environment safety and protection of urban rivers.
2023 Vol. 43 (12): 6700-6711 [Abstract] ( 223 ) [HTML 1KB] [ PDF 989KB] ( 972 )
6712 Adsorption and biodegradation pathway of benzo[a]pyrene mediated by microplastics
YE Jin-ming, LUO Ya-yan, TANG Hui-qi, OUYANG Hao-ming, XIE Qi-lai, CHEN Shuo-na
To investigate the adsorption and biodegradation of polycyclic aromatic hydrocarobons in the presence of microplastics, polypropylene-microplastics (MP-PP) and benzo[a]pyrene (BaP) were chosen as research materials. The aim was to explore the adsorption behavior and mechanism of BaP onto MP-PP, as well as its biodegradation pathway mediated by Novosphingobium tardaugens using MP-PP. The interaction and microscopic characteristics among MP-PP, BaP and strains were examined using X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The results indicated that the adsorption of BaP onto MP-PP followed the pseudo-second-order kinetic model with monolayer coverage, and this process was enhanced by higher temperatures. The presence of MP-PP improved the efficiency of BaP degradation. However, the degradation pathway of BaP by Novosphingobium tardaugens remained unaffected by MP-PP and continued to follow the phthalic acid pathway. The interaction among MP-PP, BaP, and strains primarily occurred at the surface, with microplastics PP serving as adsorption carriers. Although Novosphingobium tardaugens could not decompose MP-PP, it could adhere to the PP surface, facilitating growth, and thereby enhancing the degradation process.
2023 Vol. 43 (12): 6712-6722 [Abstract] ( 167 ) [HTML 1KB] [ PDF 1183KB] ( 1101 )
Environmental Toxicology and Health
6723 Association network survey of childhood asthma and environmental factors in Xinjiang
PENG Li, CAO Chang-an, WU Wei-qi, WANG Yu-na, LIANG Bao-pan, CAO Su-zhen, DUAN Xiao-li
To investigate the prevalence and risk factors of childhood asthma in Xinjiang, an online questionnaire survey was conducted among selected children under the age of 14 in Xinjiang in 2022, and information was obtained on the characteristics of 575 children and their families in the region, and logistic regression models were used to estimate the prevalence of asthma disease among children in Xinjiang and its association with family, parental and environmental factors. The results showed that the prevalence of asthma among children in the region was 4.7 per cent, which was a high prevalence. Maternal asthma, longer heating periods, longer opening of windows in spring and proximity to waste incineration plants or garbage dumps were significantly associated with a higher prevalence of asthma in children. Breastfeeding and physical activity were each significantly associated with a lower risk of asthma. Socioeconomic factors were not significantly associated with childhood asthma in Xinjiang.
2023 Vol. 43 (12): 6723-6731 [Abstract] ( 149 ) [HTML 1KB] [ PDF 447KB] ( 1179 )
6732 Effects of InP/ZnS QDs on cartilage development in rare minnow (Gobiocypris rarus) offspring
WU Ying-yi, CHEN Hang, XIE Wei-wei, JIN Li
Quantum Dots (QDs) are a class of nanomaterials. With the wide application of QDs, its toxic affects on organisms are also concerned. In this experiment, InP/ZnS quantum dots were used, and female rare minnows (Gobiocypris rarus) was used as the experimental animal. Three experimental groups (200, 400, 800nmol/L) were designed. Eggs were taken and fertilized at 4 and 7 days of quantum dots exposure. Using embryo fertilization rate, survival rate, body length and full length of larvae as indicators, the larvae were observed by Albion blue dye and Hematoxylin Eosin (HE) staining. The transcript expression levels of bone developmental related genes (bmp2b, sox9, runx2b) were detected to study the effect of quantum dots on the offspring cartilage development of rare minnows. The results showed that the body length and full length of larvae in high concentration group decreased by 6.2% and 5.9%. The PQ-Meckel’s angle increased by 24.8%, mandibular length decreased by 14.6% and 15.2%, and mandibular width decreased by 10.0% and 10.7%. Craniofacial chondrocytes were swelled and reduced in number. It was found that QDs had different affects on the transcript expression levels of related genes at different development time. In conclusion, InP/ZnS quantum dots can affect the skeletal development of offspring of rare minnows.
2023 Vol. 43 (12): 6732-6739 [Abstract] ( 134 ) [HTML 1KB] [ PDF 2361KB] ( 942 )
Environmental Impact Assessment and Management
6740 Assessing policy effects of the ecological environment quality monitoring authority reform: A case study on ambient air quality monitoring
XIONG Xue-Feng, YUAN Zhi-Ting, CHANG Dun-Hu, Dong Zhan-Feng
Based on the panel data of 278 prefecture cities in China from 2007 to 2016, this study levages arguably exogenous variation in the Ambient Air Quality Standard Reform in 2012 and employs a multi-time point DID model to identify the impact, transmission mechanism, and heterogeneity of environmental quality monitoring authority on air pollution. We find that the reform significantly reduces SO2 emissions and PM2.5 concentration. The emission reduction effect is positively correlated with the density of state-controlled monitoring sites. Importantly, the result remains consistent after a series of robustness tests, including placebo tests and the exclusion of other external policy impacts. Moreover, mechanism analysis uncovers two channels, namely the stringency of local government environmental regulations and green innovation of industrial enterprises, through which the reform curbs air pollution. Strategies such as limiting the number of industrial enterprises and increasing public transportation investment have proven effective in suppressing air pollutant emissions. Lastly, heterogeneity analysis shows that the air pollution reduction effect is more significant in cities with larger initial emissions and higher fiscal decentralization levels, although such effect is smaller in cities with higher fiscal pressure.
2023 Vol. 43 (12): 6740-6754 [Abstract] ( 125 ) [HTML 1KB] [ PDF 735KB] ( 868 )
6755 Differences in carbon footprint of food consumption patterns
JIANG Lu, WANG Rui, LIU Bei-bei
To analyze the carbon footprints of different food consumption patterns, taking dumplings as study objects, a life cycle assessment (LCA) from “cradle to table” was used to evaluate the carbon footprint of four consumption patterns, namely, home-made, frozen retail, chain-store operation and individual operation. The carbon footprints of transportation, storage, processing, packaging, distribution sectors were estimated. Results showed that, the carbon footprints of different dumplings’ consumption patterns increase in sequence from homemade(1.85, kg CO2eq/kg, the same below), chain-store operation (intra-city) (1.86), chain-store operation (cross-city) (1.89), frozen retail (1.96), individual operation (1.96), to chain-store operation (cross-province) (1.97). The carbon footprint of transportation sector varied widely (2.13%~7.80%), with the frozen retail pattern reaching the highest, while the chain-store operation pattern being the lowest when central kitchens for centralized distribution were reasonably well established. The study also explored the discrepancy in the carbon footprints of food waste and loss across different consumption patterns. It is suggested that establishing regional central kitchens and distribution centres, optimizing transportation routes, and reducing food loss and waste throughout the entire process will be key points to reduce carbon emissions in the residential food consumption system.
2023 Vol. 43 (12): 6755-6762 [Abstract] ( 262 ) [HTML 1KB] [ PDF 934KB] ( 1423 )
6763 The spatiotemporal evolution features and influencing factors of water environment co-governance in China: thinking based on the closed-loop and synergy mechanism of water control process
ZHANG Ning, LI Hai-yang, ZHANG Jun-biao, WANG Zi-chen, JIANG Meng-qi
Based on the closed-loop process of "front-end control, middle-end treatment and end protection", a water environment governance evaluation system was constructed from the following three dimensions: water resources endowment, water pollution prevention and water resources protection. Then the spatio-temporal evolution characteristics of water environment governance level of 31 provinces in China from 2011 to 2020 were studied by applying the coupling degree of coordination and spatial kernel density model. Further, the collaboratively governed regions were divided according to the "space-policy-economy" (S-P-E) synergistic matrix and their collaborative governance level and influencing factors were measured. The results indicated that China's water environment governance level showed the spatio-temporal evolution characteristics of "the east areas taking the lead, the middle and west areas following behind, the whole country rising, and fluctuating and expanding differences between provinces". At present, China has eight water environment collaboratively governed regions with the characteristics of "spatial proximity, policy diffusion, economic linkage". There were big differences in the level of governance among regions, though in general they were all characterized by "S" type fluctuating upward trend. Further, it was found that the advantage of water environment governance development was a necessary condition for the enhancement of regional water environment collaborative governance. "Agricultural, industrial structure, agricultural mechanization and economic development had a significant positive effect on the collaborative governance of the water environment, while openness to the outside world, urbanization and population density showed a significant inhibitory effect. In addition, the promotional effect of industrial density and technological innovation showed a lagging effect, and the collaborative governance of the water environment itself had a significant "momentum effect".
2023 Vol. 43 (12): 6763-6777 [Abstract] ( 130 ) [HTML 1KB] [ PDF 1254KB] ( 1641 )
6778 Socio-economic drivers of surface water bodies in the Guangdong-Hong Kong-Macao Greater Bay Area
YANG Zhen-hua, ZHAO Tong-tie-gang, TIAN Yu, YANG Fang, ZHENG Yan-hui, CHEN Xiao-hong
Focusing on the Great Bay Area of Guangdong-Hong Kong-Macao (GBA), the Environmental Kuznets Curve (EKC) of surface water and its socio-economic drivers were identified in the paper.Specifically, the Landsat images were utilized to extract the long-term sequence of surface water dynamics, the EKC was obtained through land use/cover change analysis and the driving factors of long-term equilibrium and short-term fluctuation were illustrated. The results shown that the urban surface water bodies in the GBA generally showed a nonlinear characteristic of first rise and then fall, and depended on the transformation characteristics between water bodies and cropland and impervious surfaces in the past 30a, with the surface water body area increasing by 1323.14km2 from 1990 to 2000, and then fluctuating and decreasing from 2000 onwards; the EKC of the surface water rate and GDP per unit area generally showed a N-type characteristics of rapid decline and gentle rebound reflect the loss/gain of water bodies by anthropogenic cover and ecological restoration/reservoir expansion projects; the DARDL-UECM model clarifies the accuracy of the simulation results (R2>0.7, P<0.000) and the contribution of factors. Regardless of the short-term fluctuation stage or long-term equilibrium stage, ratios of impervious surface, forested land and cropland area share are the main driving factors for urban surface water bodies, and the mean values of the cumulative contributions of the three factors are 0.96 and 0.93.
2023 Vol. 43 (12): 6778-6787 [Abstract] ( 148 ) [HTML 1KB] [ PDF 2837KB] ( 1136 )
6788 Research on the evolutionary game of carbon emission reduction involving four entities
CUI Ning, ZHOU Yu, ZHAO Xiao-liang
This study focused on the collaborative emission reduction governance model that involved multiple entities, wherein an evolutionary game model was constructed among the central government, local government, enterprises, and environmental NGOs. The stability of each equilibrium point was meticulously analyzed, and data simulation was conducted using Matlab software to explore the influence of varying parameters on the strategic choices of the four game participants. The findings revealed that out of the 16pure strategy equilibrium points in the game system, five were conditionally stable. The choice of strategy by the game participants was found to be dependent on the relative net benefit of that strategy, with a greater relative net benefit increasing the likelihood of the strategy being chosen by the relevant participants. It was observed that enhancing the central government's transfer payments to local governments and escalating penalties for non-implementation by local governments could stimulate their active evolution, enabling the system to transition to a stable state more swiftly. While it was noted that increasing enterprises' emission reduction subsidies could foster the growth of a low-carbon economy in the short term, it was not seen as a sustainable governance model. Excessive emission reduction subsidies were found to potentially trigger passive evolution of local governments, preventing the game system from achieving the ideal stable state. Furthermore, it was discovered that augmenting disclosure rewards for environmental NGOs could also induce enterprises to evolve proactively, facilitating the system's faster evolution to the desired stable state. In conclusion, the study proposed respective suggestions for the central government, local governments, enterprises, and environmental NGOs, thereby offering theoretical insights for the advancement of China's low-carbon economy.
2023 Vol. 43 (12): 6788-6802 [Abstract] ( 184 ) [HTML 1KB] [ PDF 2287KB] ( 1108 )
6803 Environmental regulation and firm R&D investment: crowding out or inducing-- Empirical evidence from the collection of sulfur dioxide pollution fees
XIANG Rui-bing, TIAN Cheng-shi, ZHANG Yan-chao
This paper takes SO2 emission fee, a market-based environmental regulation tool, as an example, and uses the data of China's non-financial listed enterprises from 2007 to 2019 to investigate the relationship between environmental regulation, firms’ R&D investment and stock market value. It is found that SO2 emission fee has a significant effect on the increase of R&D investment, and R&D investment has a significant effect on the fluctuation of stock market value. In terms of R&D investment, the incentive effect of SO2 emission fee on non-state-owned enterprises, small and medium-sized enterprises, senior executives' equity incentive, medium and high emission enterprises is stronger. In terms of stock market value, R&D investment under different levels of SO2 emission fee has a significant positive impact on stock market value fluctuations. On the one hand, the improvement of SO2 emission fee standard can cause green patent innovation except for enterprises in the low SO2 emission industry. On the other hand, under the background of environmental regulation, enterprises in medium and high SO2 emission industries apply R&D investment to improve their ability to absorb external advanced knowledge and technology to absorb "innovation", which proves that R&D investment has a two-way effective path to promote "endogenous self-green innovation" and "exogenous absorption innovation".
2023 Vol. 43 (12): 6803-6816 [Abstract] ( 128 ) [HTML 1KB] [ PDF 1487KB] ( 1219 )
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