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  Current Issue
 
2024 Vol.44 Issue.9,Published 2024-09-20
Air Pollution Control
Water Pollution Control
Solid Waste
Soil Pollution Control
Environmental Microbiology
Environmental Ecology
Environmental Impact Assessment and Management
Carbon Emission Control
Emerging Contaminants
Environmental Toxicology and Environmental Health
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2024 Vol. 44 (9): 0-0 [Abstract] ( 90 ) [HTML 1KB] [ PDF 271KB] ( 658 )
Air Pollution Control
4737 Multi-scale evolutions of atmospheric NR-PM1 characteristics and its influencing mechanisms
TIAN Jian, HAN Li-hui, LAN Tong, QI Chao-nan, XIAO Qian, WANG Hai-yan
An Aerodyne Aerosol Chemical Speciation Monitor (ACSM) was deployed to in situ measure the concentrations ofnon-refractory submicron particulate NR-PM1 and its species as organics Org, sulfate SO42-, nitrate NO3-, ammonium NH4+ andchloride Cl- at the southeast urban area in Beijing from December 2021 to November 2022, and further investigate the changecharacteristics of NR-PM1 and its species at different time scales, especially during the different pollution periods, and the importantfactors affecting the formation of secondary sulfate and nitrate. Meanwhile, the positive matrix factorization PMF and backwardtrajectory clustering analysis were used to study the change characteristics of organic aerosol OA components in the different periods,and the influence mechanism of air mass long-distance transport on NR-PM1 and its species in the different periods, respectively. Theresults showed that the annual average mass concentration of NR-PM1 during the study period was (7.60±10.35) μg/m3, being lowerthan the corresponding annual average since 2016, and showed a decline trend year by year. The average concentrations of NR-PM1 in different seasons showed an obvious seasonal variation characterized by autumn > spring > winter > summer, and the diurnalvariations in different seasons followed the order of night > day. The average annual mass concentration of NR-PM1 species showedan order of Org> NO3-> NH4+~ SO42-> Cl-, among which Org contributed the largest fraction of NR-PM1 with about 41.16%,followed by nitrate 33.05%, ammonium 12.47%, sulfate 11.99%, and chloride contributing the lowest fraction with 1.33%. Thediurnal variations of NR-PM1 concentrations in different seasons were all smaller, and the average concentrations of NR-PM1 and itsspecies in haze days were higher than those in ozone pollution days and clean days. The presence of alkaline NH3 in the atmosphereand the meteorological conditions during the haze days were more favorable for the secondary transformation of gaseous precursors.The OA components were different in different seasons. SOA in winter, spring and autumn is the main component of OA,while POA in summer is the main component of OA. OA in haze and ozone-polluted days was mainly affected by secondary organicmatter. The transport pathways of air mass were different in different seasons. It is noted that the haze pollution days were mainlyaffected by the short-distance transports of air mass from the southeast direction and the south direction, and NO3- showed a greatercontribution to NR-PM1. O3-polluted days were mainly affected by short-distance transports of air mass from the south direction,while clean days were mainly affected by long-distance transports of air mass from the northwest direction.
2024 Vol. 44 (9): 4737-4753 [Abstract] ( 124 ) [HTML 1KB] [ PDF 3749KB] ( 970 )
4754 Vertical distribution of atmospheric ozone in Hangzhou Region
QI Bing, XU Xiao-fei, JIN Jun-li, YANG Xin-Jie, NIU Yu-wen, ZHANG Jin-qiang
By using the domestic ECC ozonesonde to conduct one year (December 2021 to November 2022) measurements in Hangzhou,this paper investigated the characteristics of vertical ozone distribution, total column ozone and tropospheric column ozone, and evaluated the ozone profile products retrieved from the Atmospheric Infrared Sounder (AIRS) onboard the Aqua satellite and Microwave Limb Sounder (MLS) onboard the Aura satellite, and also compared the total column ozone products retrieved from AIRS, OMI DOAS and TROPOMI. The results indicated a high consistency of surface ozone measurements between the ozonesonde and ground-based ozone analyzer. The vertical ozone structure exhibited significant monthly variation in Hangzhou. A descending structure of high ozone transmission was observed in the upper troposphere-lower stratosphere region (12~16km) in May, and a high ozone content layer was observed in the boundary layer below 1.5km from April to September. The ozone concentration in the boundary layer was highest in summer, with inconspicuous vertical variation, which was followed by that in spring, autumn and winter when the ozone concentration increased with the increase of height. The ozonesonde measurements and satellite retrievals showed similar variability in the vertical ozone profiles, with a relative difference mostly <10% in the height range analyzed. The average total column ozone and tropospheric column ozone were 302.1DU and 40.5DU, respectively, which showed obviously seasonal variation. The total column ozone and the tropospheric column ozone were highest in spring and summer, respectively, and the tropospheric column ozone was highest in May. The total column ozone from ozonesonde measurements showed a good agreement with the products retrieved by AIRS, OMI DOAS and TROPOMI, with correlation coefficients of 0.78, 0.88, and 0.76, respectively.
2024 Vol. 44 (9): 4754-4764 [Abstract] ( 187 ) [HTML 1KB] [ PDF 4086KB] ( 794 )
4765 Characteristics and sources of Volatile Organic Compounds in urban Jinan, China
ZHANG Hou-yong, SUI Hao-xin, WANG Zai-feng, ZHANG Su-fan, DU Ming-yue, GE Xuan, WANG Ming, TAO Wen-xin, XU Hong-yu, GU Da-sa, ZHANG Yi-sheng
To study the characteristics and sources of ambient volatile organic compounds (VOCs) in urban Jinan, monthly offline observations from 2020 to 2021 and intensive observations in June 2020 were conducted. The inter-annual, seasonal, and daily concentration changes, chemical composition, and ozone formation potential (OFP) of VOCs were analyzed. Sources of VOCs were analyzed using the tracer ratio method and positive matrix factorization (PMF) model. The results indicated that the annual average mixing ratio of VOCs in urban Jinan in 2021 was (35.70 ± 16.58) ×10-9, an improvement of 14.48% compared to 2020, with alkanes and oxygenated VOCs (OVOCs) were the two major components of VOCs. The seasonal characteristics of the average mixing ratio of VOCs in 2020 showed a high in winter and a low in summer, while in 2021, it showed an increase in summer and a low in spring. Influenced by the special rectification action of VOCs in Jinan and the air quality assurance measures for the Beijing Winter Olympics, the average mixing ratio of VOCs in winter 2021 improved significantly compared to 2020, with an improvement rate of 31.08%. Aromatic hydrocarbons contributed significantly in the spring of 2020, which might be related to enterprises’ gradual resumption of work under epidemic control. The top ten components in 2020 and 2021 are mainly alkanes and OVOCs, such aspropane, ethane, n-butane, formaldehyde, acetone, and acetaldehyde. The annual value of OFP was 239.39μg/m3 in 2021, a decrease of 22.46% compared to 2020. The improvement rates of OFP for alkanes, alkynes, aromatics, and halogenated hydrocarbons were 29.28%, 3.09%, 67.93%, and 83.49%, respectively. The OFP for olefins increased significantly, with an increase rate of 37.49%. OVOCs remained at a relatively high level. The top ten species in OFP rankings in 2020 and 2021 mainly include formaldehyde,acetaldehyde, ethylene, 1-butene, propylene, and para/meta xylene. During heavy ozone pollution episodes, the daily variation characteristics of TVOCs volume fraction showed obvious morning and evening peak characteristics, with the noon period being the low value of the day and maintaining a high level at night. The PMF analysis showed that VOCs mainly came from industrial sources, combustion sources, oil and gas volatilization, motor vehicle exhaust emissions, solvent use sources, plant emissions, and secondary generation sources. Motor vehicle exhaust emissions, combustion sources, and industrial sources were critical sources of VOCs for O3 pollution control in Jinan.
2024 Vol. 44 (9): 4765-4777 [Abstract] ( 151 ) [HTML 1KB] [ PDF 2719KB] ( 717 )
4778 Investigations of relationship between surface ozone and temperature in the Beijing-tianjin-hebei region
ZHU Xiao-wan, LIU Xiang-xue, WU Jin, QIU Yu-lu, LI Ying-ruo, MA Zhi-qiang
To investigate the influence of meteorological conditions on long-term ozone (O3) trends, two climate penalty factors were analyzed with observed pollutant and meteorological data from multiple stations in the Beijing-tianjin-hebei region. Results demonstrated that the sensitivity of O3 to temperature enhanced after 2016. Compared the two periods before and after 2016 (2010~2015, P2; 2016~2020, P3), we found that high-temperature weather contributed to this phenomenon. The frequency in high-temperature days in the P3 period was 0.6%~5.1% higher than that in the P2 period, which was related to the enhanced influence of foehn on the plain areas during the P3period. The occurrence frequency of foehn in the P3stage was 2.7 times higher than that in the P2 stage, and the occurrence frequency of high-temperature weather under the foehn condition was 1.0~1.9times higher than that under the non-foehn condition. The enhanced sensitivity of O3 to temperature indicated that once the meteorological conditions are favorable for O3 pollution, the O3 concentration will peak in a short time, and the high concentration of O3 can be maintained for a longer time. In contrast to Beijing, pollution in other areas of the Beijing-tianjin-hebei region was severer than Beijing, and joint prevention need to be continuously strengthened.
2024 Vol. 44 (9): 4778-4785 [Abstract] ( 157 ) [HTML 1KB] [ PDF 2693KB] ( 787 )
4786 Significant factors influencing the multi-temporal-scale evolutions of PM2.5 and O3 concentrations in Xingtai City
LAN Tong, HAN Li-hui, TIAN Jian, QI Chao-nan, XIAO Qian
To reveal the evolution characteristics and influencing factors of atmospheric PM2.5-O3 complex pollution in Xingtai City, this study, based on the meteorological elements and pollutant concentration data provided by the online monitoring platform, deployed the KZ filtering method to decompose the original concentration sequences of PM2.5 and O3 in Xingtai City, and combined the multiple stepwise regression method to quantitatively identify the contribution of source emissions and meteorological factors to pollutant concentration in long-term component. Meanwhile, Random Forest method was used to qualitatively explore the effects of specific source emissions and meteorological factors on the original concentration series of PM2.5 and O3 in Xingtai City. The results showed that the long-term component of PM2.5 concentration in Xingtai City showed a significant downward trend, however, short-term component was major contributor to PM2.5 concentration. The long-term component of O3 concentration showed an increasing trend, and the seasonal component was main contributor to O3 concentration. The contribution ratio of source emissions to meteorological factors in the long-term component concentrations of PM2.5 was about 5:1, and that for O3 was close to 3.5:1. The source emission processes were the main cause of long-term atmospheric PM2.5-O3 complex pollution in Xingtai City. Relative humidity (RH) presented a significant influence on the original concentration series of PM2.5 in Xingtai City, followed by industrial source emission and vehicle exhaust emission. The three factors effectively affecting the original O3 concentration sequences were the short-wave radiation intensity (SR), temperature (T) and vehicle exhaust emission.
2024 Vol. 44 (9): 4786-4795 [Abstract] ( 105 ) [HTML 1KB] [ PDF 1540KB] ( 800 )
4796 Atmospheric ammonia distribution and contribution to PM2.5 in typical areas of Pearl River Delta
HUANG Guo-feng, XIAO Lin-hai, CHEN Zi-jie, ZHANG Tao, HONG Zhuang-min, FANG Xiao-dan, LIAO Tong, CHEN Duo-hong
To investigate the contribution of NH3 to fine particulate matter (PM2.5) in typical areas of the Pearl River Delta in Southern China, three urban sites (GYQ, MH, and DC) and one suburban site (HGS) in the Pearl River Delta were selected to carry out online monitoring of NH3. Water-soluble inorganic ion, nitric acid (HNO3), PM2.5 and meteorological parameters were collected simultaneously. The characteristics of concentration level and diurnal variation of NH3 were analyzed. The potential contribution of NH3 to PM2.5 was further evaluated. The observed results showed that the annual average of NH3 at GYQ, MH, DC and HGS were (5.74±3.0), (4.70±2.41), (5.09۬.26) and (4.17±1.95) μg/m3 respectively. Except for GYQ, the seasonal variation of NH3 in other sites showed an increasing trend of autumn > spring > summer > winter. The diurnal variation of NH3 concentration is similar to that of temperature, and opposite to that of relative humidity. According to the adjusted gas ratio (AdjGR), all sites exhibited high levels of NH3. With the increase of PM2.5 pollution concentration, AdjGR gradually decreased, while the ammonium-to-total ratio of NH3 (NHR) gradually increased. In addition, the NHR > 0.5 of the four sites mainly occurred under the meteorological conditions of temperature < 25℃ and relative humidity < 70%.
2024 Vol. 44 (9): 4796-4804 [Abstract] ( 156 ) [HTML 1KB] [ PDF 1854KB] ( 898 )
4805 Characteristics and formation mechanism of PM2.5 pollution during heavy pollution in an industrial-dominated city in Southwest China
ZHANG Dan, LI Ling, HU Wei, LYU Ping-jiang, YUAN Rui, JIANG Xue, DU Min, LI Zhen-liang, CAI Feng, ZHANG Yong, ZHANG Yun-huai
To study the characteristics and formation mechanisms of haze pollution in Changshou District, a typical industrial city in the upper reaches of the Yangtze River, observational analyses of fine particulate matter (PM2.5) and its important precursors were conducted separately in urban and industrial areas during periods of continuous haze pollution. The results showed that the mean concentration of PM2.5 in Changshou District during the observation period was (71.78±38.44) μg/m3, with the highest daily mean reaching 193μg/m3 during haze pollution episodes. Compared to non-polluted periods, various chemical components of PM2.5 increased during haze pollution, with rapid growth of organic matter (OM) and secondary inorganic aerosols (SIAs) being the primary factors contributing to haze pollution. During haze pollution episodes, the sulfur oxidation ratio (SOR) and nitrogen oxidation ratio (NOR) significantly increased, with increases of 64% and 55%, respectively, compared to clean days, and higher relative humidity (RH) environments played a promoting role in the hygroscopic growth of SOR, NOR, and aerosols. Secondary organic aerosols (SOAs) also showed a significant increasing trend during haze pollution periods, with an increase of 13.03μg/m3 compared to clean days. Evaluation of SOAP revealed that aromatics such as toluene, o-xylene, and m-xylene significantly contributed to SOA formation. Principal component analysis (PCA) and Spearman correlation analysis identified three main sources of chemical components in PM2.5, namely industrial sources, crustal sources, and dust sources, with industrial sources being the most important contributor to PM2.5 chemical composition. Source apportionment results indicated that Changshou District and its surrounding areas are important potential source regions for PM2.5, SIAs, total organic carbon (TOC), sulfur dioxide (SO2), nitrogen dioxide (NO2), and total volatile organic compounds (TVOCs), with local emissions from pollution sources playing a crucial role in haze formation.
2024 Vol. 44 (9): 4805-4816 [Abstract] ( 93 ) [HTML 1KB] [ PDF 2832KB] ( 801 )
4817 Characteristics of atmospheric precipitation chemistry and deposition in typical regions of China during 2000~2021
CHENG Yi-xuan, GUAN Jing-wen, FU Tian, JIANG Bo-qi, CHEN Qian, YU Xing-na
Based on the data of atmospheric precipitation in 10cities of the Northeast, North, East, Southeast, Northwest, and Southwest China from 2000 to 2021, a long-term variation trend was studied on precipitation amount, pH value, electrical conductivity, water-soluble ion concentration, and nitrogen and sulfur wet deposition in various regions. The ion neutralization of precipitation components in typical sites was also analyzed. The pH values of each site in China generally showed an upward trend from 2000 to 2021, but the annual average pH in Chongqing and Shanghai had not yet reached 5.6. The electrical conductivity showed a significant downward trend in Jinan, Xi’an, and Chongqing. The terrestrial characteristics were more obvious in the Northwest with a higher concentration of Ca2+ (up to 1035.2μeq/L). The concentration of NO3- showed an upward trend in Chongqing, which was related to the growth of motor vehicle ownership. The concentration of NH4+ decreased in all regions. The relatively high concentrations of Na+ and Cl- occurred in Southeast, where was influenced by sea salt. The sulfur and nitrogen wet deposition in the Northwest and the Southwest was significantly higher than that in the Southeast. The ratio of NH4+-N to NO3--N showed a downward trend in all regions, but the annual average ratio was commonly greater than 1, indicating that reduced nitrogen was dominated in nitrogen deposition. The acidity of precipitation in Southeast China was relatively higher, but the concentration of acidic ions (SO42- and NO3-) was lower, indicating that the acidity of precipitation was also influenced by the alkaline ions (Ca2+ and NH4+). The annual changes in concentrations of NO3-, NSS-SO42- and NH4+ were not significant in Xiamen and Xi’an, while the pH value and the ratio of the neutralizing potential to the acidifying potential (NP/AP) showed a significant upward trend. The value of NP/AP in Xi’an was significantly higher, reflecting that the neutralization capacity in dust in Xi’an was higher than that in the Southeast China.
2024 Vol. 44 (9): 4817-4825 [Abstract] ( 188 ) [HTML 1KB] [ PDF 1430KB] ( 627 )
4826 Simultaneous reduction of NOx and decomposition of N2O over Fe and Cu zeolite catalysts
SI Qing-yu, FAN Xing, ZHANG Wei-hang, MIAO Jing-wen, LIU Ruo-wen
Fe-Beta and Cu-SSZ-13 catalysts were prepared by ion-exchange method, and composite catalysts were prepared using different mixing methods. Performance of the catalysts in catalyzing NOx reduction and N2O decomposition at the same time was investigated. Fe0.4Cu0.1catalyst, which was composed of Fe-Beta in the top layer and Cu-SSZ-13 in the bottom layer with mass ratio of 4:1, performed the best in catalyzing the removal of NOx and N2O simultaneously and broadening the reactive temperature window. Effects of inlet gas composition on the conversion of NOx, N2O, and NH3 were investigated. Physicochemical characteristics of the catalysts were characterized by N2 adsorption-desorption, XRD, NH3-TPD, UV-Vis DRS and H2-TPR techniques. The results showed that Cu-SSZ-13 and Fe-Beta had superior performance in catalyzing NOx reduction and N2O decomposition, respectively. In the tested temperature range, NOx was reduced by NH3 while N2O was decomposed over Fe0.4Cu0.1 when [NH3]/[NOx] was 1. NOx and N2O conversion reached 93.4% and 100%, respectively at 450℃. Oxidation of NH3 by O2 at high temperatures (>350℃) leads to decrease in NOx conversion with increasing temperature. And the formation of oxygen species from the decomposition of N2O at high temperatures (≥350℃) explains the efficient NOx reduction without O2 in the inlet gas. The presence of 2%H2O in the inlet gas hardly affected the reduction of NOx and oxidation of NH3 over Fe0.4Cu0.1 at high temperature (450℃), but did show reversible inhibitory effects on the conversion of N2O. Abundant isolated Cu2+ ions were detected over Cu-SSZ-13, providing sufficient active centers for the NH3-SCR reaction. Both isolated Fe3+ ions and FexOy species, which can catalyze NO oxidation and N2O decomposition, respectively, were detected over Fe-Beta. Using the top-Fe-bottom-Cu composite catalyst, NO oxidation occurs over Fe-Beta, which consumes oxygen species formed from N2O decomposition and thus promotes the conversion of N2O at low temperatures (≤450℃). However, the promotion effect of NO oxidation on NOx reduction was insignificant since NOx conversion was rather high in the temperature range for effective N2O decomposition.
2024 Vol. 44 (9): 4826-4834 [Abstract] ( 131 ) [HTML 1KB] [ PDF 1076KB] ( 870 )
4835 Black carbon during haze processes impact on aerosol scattering hygroscopic growth
TONG Jing-zhe, MI Jia-yuan, TU Chao-yong, LI Na, LI Zong-hao, DENG Ye, NI Chang-jian
Based on the hourly observed “dry” aerosol scattering coefficient, aerosol absorption coefficient, and the environmental meteorological monitoring data, and the retrieved aerosol particle size hygroscopic growth factor (Gf) from October to December 2017 in Chengdu, the statistical characteristics of black carbon concentration (CBC) were analyzed under four kinds of haze intensity conditions. Besides, the influence mechanism for CBC on the aerosol scattering hygroscopic growth was investigated using the aid of Generalized Additive Model (GAM). The results show that: (1) CBC obeyed lognormal distribution under slight, mild, moderate, and severe haze conditions. The averaged value of CBC increased but the variation coefficient of CBC decreased with increasing haze intensity. (2) CBC showed nonlinear negative correlations with Gf, and nonlinear positive correlations with CPM2.5/PM10 (mass concentration ratio between fine particulate matter and coarse particulate matter) (passing the α=0.01 significant test). Haze development intensified the downward trend of Gf with CBC and reduced the upward trend of CPM2.5/PM10 with CBC. (3) There were significant interactions between CPM2.5/PM10and Gf (passing the α=0.001 significant test). The bivariate GAM model with Gf and CPM2.5/PM10 could better characterize the variation on f.
2024 Vol. 44 (9): 4835-4843 [Abstract] ( 110 ) [HTML 1KB] [ PDF 1016KB] ( 793 )
4844 Characteristics of pollution, emission inventory and light absorption of nitrated aromatic compounds in PM2.5 from residential coal combustion in Guanzhong Plain
WANG Jia-li, ZHANG Qian, WANG Yi-xuan, ZHAO Zi-yi, SUN Jian, SHEN Zhen-xing
In order to investigate the differences in the molecular composition, regional emission and light absorption contribution of nitrated aromatic compounds (NACs) produced by different combustion methods of residential coal in rural areas of Guanzhong Plain, bituminous coal and anthracite were selected as fuels. Based on the field stove and dilution sampling system, the characteristics of (NACs) emissions from coal combustion were studied by using ultra-high performance liquid phase and four-pole time-of-flight mass spectrometry. The results show that the average emission factor of ΣNACs (EFΣNACs) during coal combustion in Guanzhong area was 3.7mg/kg, in which bituminous briquette (7.5mg/kg) > anthracite briquette (2.7mg/kg) = bituminous coal (2.7mg/kg) > anthracite (1.7mg/kg), the EFΣNACs produced by coal combustion in different stoves were significantly different. In traditional stoves, the EFΣNACs emitted by bituminous briquettes were the highest, followed by anthracite briquettes and bituminous raw coal, and anthracite raw coal was the lowest. The EFΣNACs from bituminous briquette decreased the most after the use of air distribution furnace. The light absorption value of ΣNACs at 365nm was bituminous briquette traditional stove > anthracite briquette traditional stove > bituminous briquette air distribution furnace > anthracite air distribution furnace > bituminous traditional stove > anthracite traditional stove > anthracite traditional stove. In this paper, the total emission of ΣNACs from coal combustion in five cities of Guanzhong Plain in 2019was estimated to be 198.8t, with Weinan (91.6t) > Xi ’an (32.2t) > Xianyang (29.2t) ≈ Baoji (29.0t) > Tongchuan (16.8t).
2024 Vol. 44 (9): 4844-4852 [Abstract] ( 93 ) [HTML 1KB] [ PDF 1905KB] ( 655 )
4853 Novel Ce-doped MnOx catalysts for highly efficient catalysis of toluene oxidation at low temperature
. WANG Pei-fen, AN Xiao-wei, MA Xu-li, GUAN Guo-qing, HAO Xiao-gang
Novel Ce-doped MnOx bimetallic catalyst was successfully prepared by co-oxidation-precipitation method, and the influence of synergy between Ce and Mn was explored for catalytic toluene oxidation at low temperature. Characterizations by SEM、XRD、N2 adsorption-desorption、XPS、EPR、H2-TPR, and in situ DRIFTS were performed for the prepared catalysts. It is found that the catalysts with an optimum Ce/Mn molar ratios of 1:3 had a highest performance with T50 of 215℃ and T90 of 233℃, good durability and water resistance for the toluene oxidation. Meanwhile, the results confirmed that the introduction of Ce was beneficial to adjust the morphology of CeMn3Ox catalyst with the formation of coral-structure, leading to the increase in the number of interfaces between crystalline-amorphous, which caused more defects and oxygen vacancies in the bulk of catalyst, promoting the conversion of Olatt↔ Osur↔Oads and enhancing the reducibility. Finally, in situ DRIFTS spectra verified that toluene oxidation followed two reaction pathways under air conditions,Ⅰ:adsorption→benzyl alcohol→benzaldehyde→benzoate→phenol→ benzene ring C=C breakage→ CO2 and H2O,Ⅱ: adsorption → benzene ring C=C cleavage breakage →Maleic anhydride→ CO2 and H2O, in which the C=C breakage of the aromatic ring was considered as a rate-controlled step.
2024 Vol. 44 (9): 4853-4863 [Abstract] ( 97 ) [HTML 1KB] [ PDF 2737KB] ( 711 )
4864 Analyze of characteristics and potential source of atmospheric CO2 concentration in the context of COVID-19 at the Shanghai station
GUO Peng, QING Xue-mei, LIN Yi, ZANG Kun-peng, CHEN Yuan-yuan, LIU Shuo, CHEN Bing-jiang, LAN Wen-gang, GAO Wei, FANG Shuang-xi
Based on the atmospheric CO2 records in the Shanghai Tower station (SH station) from April 2021 to December 2022, this study focused on the characteristics of atmospheric CO2 concentration and emission sources in Shanghai, and analyzed the differences in CO2 concentration during the landfall of Typhoon "In-Fa", the Chinese New Year, and the lockdown during COVID-19 pandemic. The results showed: the diurnal variation of CO in the atmosphere at the SH station had a distinct bimodal pattern (11:00 LT and 17:00 LT), corresponded to the peak times of local human activities. The CO2 concentration on weekdays was higher than that on weekends, and the concentration difference mainly appeared at 03:00~05:00LT and traffic rush hours. The CO2 concentration remained low from April to September, with the lowest value in July ((423.42±0.05)×10-6) and the highest value in December((445.94±0.27)×10-6). During the landing of Typhoon "In-Fa", the atmospheric CO2 concentration was diluted by the combined action of precipitation leaching and strong local wind. During the Chinese Spring Festival and the COVID-19 lockdown, anthropogenic activities plummeted and traffic was restricted during the lockdown, that significantly reduced the atmospheric CO2 concentration. Backward trajectory clustering and weighted potential source contribution function (WPSCF) analysis indicated that the air masses from the ocean diluted the CO2 concentration at the SH station, and the anthropogenic emissions from urban traffic and industry in Anhui, Jiangsu, Hubei and Zhejiang regions to the west of the SH station were the primary potential sources for the atmospheric CO2 at the SH station.
2024 Vol. 44 (9): 4864-4873 [Abstract] ( 128 ) [HTML 1KB] [ PDF 2502KB] ( 653 )
4874 Dynamic study on enhancing the collision coefficient between fugitive particles and magnetic seeds based on multi-field coupling
ZHANG Li-An, DU Chuan-Mei, DIAO Yong-Fa, SHEN Heng-Gen
This paper focuses on enhancing the collision coefficient between fugitive particles and magnetic seeds through multi-field coupling. Based on the computational fluid dynamics-discrete phase model (DPM), a user-defined function(UDF) was used to include the effects of the Coulomb force and magnetic dipole force acting on the fugitive particles. The collision coefficient between the fugitive particles and magnetic seeds in the multi-field formed by the electric and magnetic fields was numerically calculated, and the dynamic mechanism of enhancing the magnetic agglomeration process of particles was obtained. Simulations reveal that, for a fluid velocity of 0.5m/s and particle diameters ranging from 0.5μm to 2.0μm, both Coulomb and magnetic dipole forces enhanced the collision coefficient between the particles and magnetic seeds. Furthermore, the Coulomb force compensated for the problem that the magnetic dipole force between the weakly magnetic particles and the magnetic seeds was small. When the electric field strength(E0) was equal to 0.5kV/cm, the saturation magnetizationof fugitive particles(Mj) and magnetic seeds(Mi) were 500A/m and 40000A/m, respectively, the collision coefficient between fugitive particles and magnetic seeds was increased by 13.50% compared with that without charging. When the charge field strength(E0) was equal to 1.0kV/cm, the collision coefficient was increased by 23.60%.
2024 Vol. 44 (9): 4874-4882 [Abstract] ( 118 ) [HTML 1KB] [ PDF 1921KB] ( 621 )
Water Pollution Control
4883 Optimization of nitrogen removal performance of partial nitrification AO process based on PVA-SA immobilized particles
LI Xiang, PAN Zheng-wei, HOU Lian-gang, TANG Peng, SHI Tian-hao, LI Jun, ZHENG Zhao-ming
Partial nitrification activated sludge immobilized with polyvinyl alcohol-sodium alginate (Polyving Akohol-Sodium Alginate, PVA-SA) was used to treat domestic wastewater and achieve stable partial nitrification in a continuous flow AO (Anaerobic/Oxic) reactor. Using the response surface method, the effects of hydraulic retention time (HRT), internal recirculation ratio and filling rate on nitrite accumulation ratio (NAR) and total nitrogen removal nitrogen removal efficiency (NRE) were investigated, and a quadratic regression model was successfully established. The results showed that the system had the best performance in nitrogen removal with NAR and NRE reaching 86.22% and 86.56% when HRT, internal recirculation ratio and filling rate of aerobic section were controlled as 6.43h, 2.93, and 25%, respectively. In addition, it was observed by live and dead bacteria and Fluorescence In Situ Hybridization (FISH) that the live cells were mainly distributed in the range of 0~500μm on the surface of the particles, while the dead bacteria were distributed in the range of 0~300μm. FISH fluorescence was gradually decreased in intensity with the increase of depth. Finally, 16S rRNA sequencing results showed that the relative abundance of Nitrosomonas increased from 0.013% to 5.02% and Nitrospira increased from 0.055% to 1.99% in the immobilized particles of the long-term run compared with that of the partial nitrification activated sludge. The proportion of NOB in the nitrifying bacteria was reduced, while the proportion of AOB was increased, which contributed to the stabilization of nitrogen removal effect of partial nitrification. This study provides a promising technology for the engineering application of partial nitrification in municipal wastewater plants.
2024 Vol. 44 (9): 4883-4892 [Abstract] ( 142 ) [HTML 1KB] [ PDF 4065KB] ( 780 )
4893 Research on the effect of EPS on bacterial coagulation and granulation of flocculated sludge
WANG Jing-hua, YUAN Lin-jiang, HE Xiang-feng, XIA Da-peng, CHEN Xue-jiao, ZHENG Yuan
In order to explore the influence of extracellular polymers substances on bacterial aggregation and flocculent sludge agglomeration and granulation, bacterial aggregation by adding LB-EPS and TB-EPS to the bacterial suspension was observed. By adding bacteria EPS to the reactor (No. 1) or not (No. 2), the growth changes of aerobic granular sludge in the two reactors were investigated. The aggregation and precipitation efficiency of kaolin mixed solution and bacterial suspension was carried out by simulated EPS and real EPS respectively. The results showed that the aggregation efficiency of LB-EPS for bacteria was higher than that of TB-EPS in both groups of reactors. The sludge in reactor No. 1 grew rapidly and granulated. On the 70th day, the D50 of the sludge reached 377.5μm, and the maximum particle size could reach 1.4~1.5mm. From day 90 to day 100, due to insufficient organic load of sludge, the EPS concentration decreased, the granular sludge disorganized rapidly, and the sludge particle size decreased rapidly, and the D50 decreased rapidly from 296.5μm to 109.6μm. The particle size of sludge in reactor No.2 increased to 239.5μm (D50) on day 70, and continued to rise thereafter. The simulated EPS had more significant flocculation ability for kaolin, and the EPS had more significant effect on the aggregation of bacteria in bacterial suspension. It was concluded that extracellular polymers had adhesion effect on bacteria and promoted bacterial aggregation, and the adhesion effect of LB-EPS on bacteria was greater than that of TB-EPS. The addition of EPS could accelerate the granulation process of sludge. In the process of sludge granulation, the adsorption and aggregation effect of LB-EPS on free bacteria was greater than that of TB-EPS.
2024 Vol. 44 (9): 4893-4900 [Abstract] ( 128 ) [HTML 1KB] [ PDF 1824KB] ( 1374 )
4901 Influence of sulfide on the desulfurization-denitrification performance of the sulfide-driven autotrophic denitrification and anaerobic ammonia oxidation process
WANG Ya-ge, TANG Xi-fang, LIU Jia-yi, FU Yu-lin, GUO Qiong, CHEN Rong, JIN Ren-cun, XING Bao-shan
In this study, mature anammox granular sludge and methanogenic granular sludge were used as inoculum to achieve rapid start-up of the sulfide-driven autotrophic denitrification and anammox (SADA) process. The effects of different sulfide loading on nitrogen removal of the SADA process and its desulfurization mechanism were investigated. Results showed that high sulfide loads (>1.50g S/(L·d)) had no significant inhibitory effect on Anammox bacteria (AnAOB), and the corresponding nitrogen removal efficiency stabilized after 1.5 months of continuous operation. When the sulfide concentration was reduced to zero, the total nitrogen removal efficiency (TNRE) still reached 88.1%, and the stoichiometric ratios of Rs (1.23 ± 0.13) and Rp (0.33 ± 0.08) were similar to the theoretical values of Anammox reaction, indicating that the AnAOB was capable of performing nitrogen removal after removing the high sulfide loading conditions. When the high sulfide loading stress was relieved for 1.5months and was replaced by lower sulfide loading (0.30g S/(L·d)), the effluent showed a decrease in NO3- with the Rp of 0.21, indicating that the SADA system achieved simultaneous nitrogen and sulfur removal. The presence of methanogenic granular sludge reduced the inhibition of AnAOB caused by the sulfide, which shortened the start-up time of the SADA process. Meanwhile, the coupling system can activate the desulphurization-denitrification process quickly after reintroducing sulfide. Morphological analysis and high-throughput sequencing technique showed that in the SADA system AnAOB (e.g., Candidatus Kuenenia, 16.9%) and sulfur-oxidizing bacteria (e.g.Thiobacillus, 31.6%) were enriched under different sulfide stresses, contributing to high total nitrogen removal (>60%) and sulfur production (95.2%) under high sulfide loading.
2024 Vol. 44 (9): 4901-4909 [Abstract] ( 115 ) [HTML 1KB] [ PDF 1750KB] ( 901 )
4910 Comparison of operating performance and microbial characteristics achieving mainstream Anammox between continuous low-oxygen aeration and intermittent aeration modes
LI Yan, ZHOU Xin, PING Cai-xia
Operating performance of mainstream anaerobic ammonia oxidation (Anammox) for treating simulated municipal wastewater was compared respectively under two modes of continuous low-oxygen aeration and intermittent aeration. Intermittent aeration achieved mainstream Anammox in a shorter period with only 24d. The ammonia removal efficiency (ARE) was (96.0±1.0)% and the total nitrogen removal efficiency (TNRE) was (80.2±2.0)% under intermittent aeration. Compared with continuous aeration, nitrogen removal efficiency was more stable and nitrogen removal loading rate was higher. Intermittent aeration elevated both aerobic and anaerobic anammox activities, promoting extracellular polymeric substance (EPS) secretion, increasing protein (PN) content and protein/polysaccharide (PN/PS), which could form a more dense and red anammox biofilm structure. Three-dimensional fluorescence spectra found that the fluorescence intensity of peak A of soluble EPS (S-EPS) increased significantly during intermittent aeration. High-throughput sequencing confirmed that different aeration ways caused significant differences in microbial community composition and quantity of functional genes. Intermittent aeration improved the population structure and increased the relative abundance of aerobic ammonia oxidizers and contributed to the enrichment of Anammox bacteria (Candidatus Brocadia, Candidatus Kuenenia). The gene annotation results indicated synergistic nitrogen removal pathway of partial nitrification/partial denitrification +anammox existed in intermittent aeration condition.
2024 Vol. 44 (9): 4910-4917 [Abstract] ( 106 ) [HTML 1KB] [ PDF 1865KB] ( 1123 )
4918 Removal of phosphates and Cr (VI) from water by iron lanthanum bimetallic MOF
JIN Shi-yi, GUO Bo, CAO Qun, FENG Fan, CHEN Cai-yu, WANG Rui-lin
A magnetic Fe/La bimetallic MOF (Fe/La-MOF) material, which prepared by a rapid and efficient electrodeposition method, was applied for phosphates and Cr(VI) removal from water. The results indicated that the individual phosphate or Cr(VI) removal rates could reach over 94% for phosphate (initial concentration of 100mg P/L) or 95% for Cr(VI) (initial concentration of 20mg Cr/L) after 120 min reaction under the conditions of a equimolar ratio of Fe to La, Fe/La-MOF dosages of 1g/L (for phosphate) or 2.5g/L (for Cr(VI)) and ranges of pH 2~7 (for phosphate) or pH 2~11 (for Cr(VI)), respectively. The Langmuir isotherm model could fit the adsorption of phosphate or Cr(VI) by Fe/La-MOF well, with theoretical maximum adsorption capacities of 350.4mg P/g and 33.4mg Cr/g, respectively. The adsorption behavior of phosphate or Cr(VI) by Fe/La-MOF could be better described by pseudo-second-order kinetics model, implying that the process is mainly chemical adsorption. Characterization results of XPS, XRD and FTIR revealed that ligand exchange between phosphate or Cr(VI) anions and Fe/La-OH could be the main removal mechanism. Furthermore, the magnetic Fe/La-MOF would be easy separated with good stability through 3 cycles of use. The good performances on simultaneous removal of phosphate and Cr(VI) were also exhibited with the removal rates of 100% for phosphate (initial concentration of 25mg P/L)and 92.2% for Cr(VI) (initial concentration of 20mg Cr/L) after 120min reaction under a neutral pH and Fe/La-MOF dosage of 2.5g/L. In general, Fe/La-MOF is a highly efficient adsorbent for removing phosphate or Cr(VI) with greater adsorption capacities and good stability in a wider pH range.
2024 Vol. 44 (9): 4918-4928 [Abstract] ( 109 ) [HTML 1KB] [ PDF 2063KB] ( 1382 )
4929 Co-doped zeolitic imidazolate framework-L for more rapid phosphate removal
SUN Tai-yan, PENG Hai-hao, TONG Jing, XIANG Yin-ping, XU Zheng-yong, YANG Zhao-hui, XIONG Wei-ping
In order to reduce the harm of water eutrophication and improve the efficiency of phosphorus removal by adsorption method, this paper studied the effect of cobalt doping on the phosphate adsorption capacity of Zinc-based leaf zeolitic imidazolate framework-L (Zn-ZIF-L). In this paper, intermittent adsorption tests were used to study the influence of various influencing factors on the adsorption. XRD, XPS, FT-IR and other methods were used to study the surface microstructure of the materials to speculate the possible adsorption mechanism. It was found that the adsorption performance of Zn was the best when the initial molar ratio of Zn to Co was 9.5:0.5. After doping, the adsorption capacity increased by 55% within 10min, the maximum adsorption capacity could reach 85.68mg/g, and the adsorption performance was maintained under different temperature, concentration, pH value of 4~8, different anions and humic acid environments. When the initial concentration was 10mg/L, more than 97% of phosphorus could be adsorbed. More than 93% of phosphorus could be retained in 0.1mol/L Cl- or NO3-. Additionally, the chemical bonding between P-OH and Zn-OH/Co-OH, electrostatic interaction, and hydrogen bond interaction played a leading role in phosphate adsorption. Moreover, Co(0.5)-Zn-ZIF-L could keep a high adsorption capacity after four cycles. These findings suggest that Co(0.5)-Zn-ZIF-L can effectively remove phosphate from water.
2024 Vol. 44 (9): 4929-4938 [Abstract] ( 119 ) [HTML 1KB] [ PDF 1850KB] ( 693 )
4939 Mechanisms regarding the enhanced degradation of chlorinated organophosphates by ultrasound-assisted thermally activated persulfates
LEI Hui-hui, WANG Xiao-fei, WANG Chao-yi, WANG Ya-wei, WANG Xue-dong, KONG Ling-zhao, QIN Hong-bing, WANG Jun-xia
A heat-coupled ultrasonic activated persulfate (Heat/US/PDS) oxidation degradation technology of tri (2-chloroethyl) phosphate (TCEP) was established in this study. The reaction parameters were optimized by the central combination design method (CCD) of the response surface (RSM). The reaction parameters of TCEP removal in this system were more moderate (ultrasonic power was 402.5W, temperature was 52.6℃, reaction time was 120min), and the degradation rate of TCEP was predicted to reach 95.3%. Both coexisting ions and humic acids inhibited the removal of TCEP, and the degradation rate of TCEP was 76% in the four water bodies. Radical quenching experiments and EPR analysis showed that SO4·- and ·OH were the main reactive oxygen species. Five possible degradation intermediates of TCEP were detected. Zebrafish embryo exposure experiment showed that TCEP was safe to react in aqueous solution in this system, and the ecotoxicity of TCEP and its possible products to large fleas, algae and fish was evaluated, and the ecotoxicity of degradation products to aquatic organisms was low.
2024 Vol. 44 (9): 4939-4947 [Abstract] ( 95 ) [HTML 1KB] [ PDF 1956KB] ( 665 )
4948 Dynamics and endogenous release potential of phosphorus at sediment-water interface in Chaohu lakeshore in spring and summer
WANG Ji-chao, HUANG Tao, XU Dan, LI Sheng-jing, WANG Bo, YIN Hao-jie, SUN Qing-ye
By using the traditional manual sampling method and diffusive gradients in thin films technique (DGT), we analyzed the phosphorus species in overlying water, interstitial water, and sediment, and DGT-labile phosphorus (DGT-P) and DGT-labile iron (DGT-Fe) in interstitial water, to investigate the dynamics and diffusion flux of phosphorus in the northwestern lakeshore of Chaohu Lake during the spring and summer seasons. Significant decrease of phosphorus in overlying water in early summer was likely due to its rapid uptake by algae. While significant seasonal variations of phosphorus species in interstitial waters were observed. Authigenic phosphorus was the primary form of inorganic phosphorus in the lakeshore sediments. Lower level phosphorus but higher release potential from sediments in the water-level fluctuation zone (S1, S2) in northwestern Chaohu Lake were observed in contrast to those in the dam isolation zone (S3), due to their different level of organic matter and hydrodynamic disturbance. The release potential of endogenous phosphorus from sediments in summer is higher than that in spring. Correlation analysis between DGT-P and DGT-Fe indicated that the release of endogenous phosphorus from sediments in water-level fluctuation zone is mediated mainly through the iron-bound phosphorus reduction, while those in S3 is weak.
2024 Vol. 44 (9): 4948-4957 [Abstract] ( 103 ) [HTML 1KB] [ PDF 1637KB] ( 629 )
4958 Nitrogen removal efficiency and mechanism of Feammox/NDFO coupling process in electrochemical system
HU Jing-tao, XIN Xin
In order to improve the defects of the slow start-up and poor nitrogen removal efficiency of the Feammox/NDFO coupling process, a strategy to strengthen the start-up of Feammox/NDFO coupling process based on the principle of electrochemistry was proposed in this paper. The anaerobic sequencing batch reactor based on bio electrochemical system (BES) (named B group by authors) was built in the laboratory, and take an general anaerobic sequencing batch reactor (A group) without bio- electrochemical systems as the control group. Reactors A and B were operated for 100 days. The nitrogen removal efficiency, nitrogen removal pathway verification and microbial structure during the start-up process were analyzed, and the mechanism of enhanced denitrification in reactor B system was discussed. The results showed that the NH4+-N removal rate of reactor B was significantly improved, with the removal rate reaching approximate 100% and the TN removal rate reaching 65.83% on the 76th day.However, the NH4+-N and TN removal rates reached 50.22% and 43.01% on the 100 th day in group A. The results of nitrogen removal pathway verification experiment showed that Feammox, NDFO and Anammox reactions were all occurred in both groups A and B, and denitrification rate in group B was higher than that of group A. Compared to group A, the relative abundance of Desulfobacterota which belongs to Feammox/NDFO functional bacteria in in group B was higher than group A with 2.34%. And Thiobacillus and Denitratisoma were higher 1.1.3 and 0.87% than those of group A. BES could accelerate the enrichment of Feammox functional bacteria and denitrifying bacteria, and these bacteria could carry out extracellular electron transfer through BES electrode to enhance nitrogen removal efficiency.
2024 Vol. 44 (9): 4958-4967 [Abstract] ( 101 ) [HTML 1KB] [ PDF 1607KB] ( 824 )
4968 The effect and mechanism of dielectric barrier discharge combined with pulse corona discharge to inactivate of Aeromonas veronii in water
ZHU Zhen-fei, YAN Peng-cheng, ZHANG Rong, ZHANG Min, QU Guang-zhou
In this study, the DBD combined with PCD (DBD/PCD) was used to inactivate Aeromonas veronii in water. The synergistic effect of DBD and PCD was analyzed, and the effects of voltage, pH, carrier gas type and flow rate on the inactivation efficiency of Aeromonas veronii were investigated. The inactivation mechanism of Aeromonas veronii was explored, The types and effects of active substances were analyzed, and the safety of the DBD/PCD was verified through the experiment of zebrafish challenge. The results showed that the inactivation effect of DBD/PCD to Aeromonas veronii was significantly higher than that of DBD and PCD alone, and their synergistic coefficients were both greater than 1. After 420s of treatment, DBD/PCD can reduce the concentration of Aeromonas veronii by 7 orders of magnitude; Increasing the discharge voltage can significantly improve the inactivation efficiency of Aeromonas veronii; Under alkaline conditions, oxygen as a carrier gas is beneficial for the inactivation of Aeromonas veronii; The effect of air flow rate on inactivation efficiency is not obvious in the range of 0.5~1.5L/min. The active substances produced in the DBD/PCD system first act on the outer membrane of Aeromonas veronii cells, causing them to rupture, and then enter the cells to cause damage to intracellular proteins and the virulence genes, ultimately leading to the inactivation of Aeromonas veronii. Active substances (·OH, 1O2 and O2-) produced by DBD/PCD system play an important role in the inactivation of Aeromonas veronii. The experiment of zebrafish challenge showed that the DBD/PCD is a safe and efficient method to inactivate pathogenic microorganisms in water bodies.
2024 Vol. 44 (9): 4968-4977 [Abstract] ( 108 ) [HTML 1KB] [ PDF 3877KB] ( 839 )
4978 Efficiency and mechanism of removing ammonium from groundwater by manganese oxides with different crystal forms
CHENG Ya, MIAO An-qi, HUANG Ting-lin, WEN Gang
The efficiency and mechanism of removing ammonium from groundwater by manganese dioxide with three different crystal forms (α-MnO2, γ-MnO2, δ-MnO2) were studied, and the practical application efficiency of the filter column filled with γ-MnO2 coated filter media was investigated. The experimental results showed that γ-MnO2 possessed the best catalytic oxidation activity for removing ammonium (γ-MnO2>α-MnO2>δ-MnO2), 5mg/L NH4+-N could be completely removed on the 20th day, and the accumulation time of nitrite was the shortest and the peak value was the lowest. The filter column filled with γ-MnO2 coated filter media could quickly (the 6th day) form excellent catalytic activity, when the influent NH4+-N was 2.0mg/L, the effluent NH4+-N was lower than the standard limit (<0.5mg /L). Combined with the characterization analysis, it was found that the highest catalytic activity of γ-MnO2 was mainly due to its higher average manganese oxidation state and abundant surface hydroxy oxygen, and its electron transport ability was the strongest. This study provides theoretical guidance for the application of manganese oxides in the field of ammonium removal from drinking water. γ-MnO2 coated filter media has good catalytic oxidation stability and efficiency, and provides a new perspective for the preparation of catalytic oxidation active filter media in practical engineering.
2024 Vol. 44 (9): 4978-4986 [Abstract] ( 98 ) [HTML 1KB] [ PDF 2527KB] ( 697 )
4987 Research progress on suitable groundwater depth towards sustainable development and utilization of groundwater resources
DU Xin-qiang, FANG Yong-jun, GUO Hui, LU Xiang-qin
The sustainable development and utilization of groundwater resources attempts to satisfy the water demands of human society while securing the ecological and environmental functions of groundwater; the key challenge lies in the identification of the appropriate groundwater burial depth (suitable groundwater depth). In this study, the impacts of changes in groundwater depth on the surface ecological environment from regional to micro scales are reviewed and summarized, and the primary role of the groundwater depth in facilitating the ecological and environmental effects of groundwater is highlighted. The main factors affecting the determination of suitable groundwater depth are identified as the surface vegetation growth, crop growth and yield, soil salinization, land subsidence, and seawater intrusion. Field surveys, remote sensing inversion and stable isotope composition analysis techniques are commonly employed. It is claimed that the ecological and environmental functions of groundwater were primarily studied on arid areas, with progress in non-arid areas advancing more slowly. A method for determining suitable groundwater depth for the sustainable development and utilization of groundwater resources is then proposed, based on the natural geographical and hydrogeological conditions of the study area, as well as the main ecological and environmental issues; a set of regional-scale control indicators for the suitable groundwater depth is established. Finally, combined with the regional ecological environmental protection objectives, the suitable groundwater depth range and thresholds are comprehensively determined through selection and overlay calculation of indicators. At present, there are many researches on the spatial distribution of suitable groundwater depth. However, research into their temporal distribution patterns remains relatively weak, representing one of the significant future directions for studies on suitable groundwater depth.
2024 Vol. 44 (9): 4987-4998 [Abstract] ( 107 ) [HTML 1KB] [ PDF 929KB] ( 908 )
4999 Research progress of groundwater pollution source identification based on process simulation
ZHENG Chuang, DONG Jun, ZHANG Wei-hong, GE Yuan-bo
Groundwater is an important water resource. Compared with air and surface water, groundwater pollution has the characteristics of concealment, lag and irreversibility. After the occurrence of groundwater pollution, the information of pollution sources (quantity, location, release history) can be quickly grasped through the identification of pollution sources, which plays an important role in the prevention and control of groundwater pollution sources, the reasonable design of pollution remediation programs, and the accurate identification of pollution responsibilities. In this paper, the mathematical equation inversion method based on process simulation in groundwater pollution source identification was reviewed. Besides, the relevant literature based on CiteSpace and VOSviewer bibliometric software was analyzed to obtain the research status and hot spots in this field. Finally, the future development trend in the research of mathematical equation inversion based on process simulation was put forward.
2024 Vol. 44 (9): 4999-5006 [Abstract] ( 127 ) [HTML 1KB] [ PDF 1541KB] ( 1173 )
5007 Mechanism of emulsifiedzero-valent iron remediation of aquifer contaminated by perchloroethylene
ZHAO Hai-feng, DONG Jun, SUN Chen, WANG Wei-Ya, ZHU Kai
During the remediation of chlorinated hydrocarbon-contaminated aquifers, emulsified zero-valent iron (EZVI) demonstrates high reactivity, strong mobility, and excellent performance without secondary pollution. To elucidate the degradation pathways of perchloroethylene (PCE) in aquifers by EZVI, this study investigates the impact of the degradation process on the mineral composition of aquifer media, as well as the key microbial species and their functions during remediation. The study aims to clarify the mechanism of the EZVI-PCE-aquifer medium-microbial community reaction system in the context of PCE-contaminated aquifer remediation. Three sets of control experiments—EZVI, Emulsified oil (EVO), and inactivated EZVI—were designed to examine the variations in pollutant and mineral ion concentrations across different reaction systems. The aquifer media were characterized using X-Ray Diffraction (XRD) and microbial 16S rRNA gene sequencing. The results indicate that the primary degradation pathways of PCE by EZVI are chemical reduction and bioreduction, with the former accounting for 77.4% of the PCE degradation. The degradation process affects the aquifer medium composition in two ways: the dissolution reactions of potassium feldspar (Kfs) and albite (Ab) under acidic conditions, and the formation of siderite (Sid). The remediation process exerts a selective pressure on the microbial community, resulting in a dominance of Sporacetigenium, Syntrophomonas, and Dechlorosoma, which are associated with anaerobic fermentation to produce acids, methanogenesis, and biotic dechlorination, respectively.
2024 Vol. 44 (9): 5007-5015 [Abstract] ( 96 ) [HTML 1KB] [ PDF 1639KB] ( 697 )
5016 Quantitative source apportionment and origin analysis of Fe and Mn in the middle and lower reaches groundwater of Chaobai alluvial-proluvial fan, Beijing
CHEN Ji-ji, TAO Lei, XI Yue, TIAN Ying, XU Su-shi, LIU Bao-xian, JING Hong-wei
In order to identify the sources and hydrochemical origin of groundwater with high concentration of Fe and Mn, principal component analysis method and absolute principal component-multiple linear regression model were used to analyze the sources of Fe and Mn in groundwater, and quantify the contribution of each source. Meanwhile, Durrov diagram, chlor-alkali index and mineral saturation index were used to reveal the influence, chemical characteristics and origin of Fe and Mn from different sources. The results showed that the ratio of Fe and Mn exceeding class III standard accounted for 45.6% and 59.4%, respectively. In addition, the concentration levels of Fe and Mn and the rates exceeding the standard were generally higher in wet season than that in dry season. The groundwater in the study area was in a reduction environment, and pH, TOC and sampling depth were the main environmental factors affecting the groundwater quality. Three main components about Fe and Mn were extracted by principal component analysis (PCA), namely, the migration-enrichment effect (F1), the natural dissolution effect of Fe and Mn oxides (F2), and the hydrochemical effect (F3). The main influencing factors of the three principal components were hydrogeological conditions, reduction environment and pH. F1 and F2 were the main reasons which lead to the excess of Fe and Mn in the first and second aquifers, and the low Fe and Mn groundwater formed by F3was distributed in all aquifers. Fe and Mn were easily enriched in HCO3-Ca·Mg groundwater (F1and F2), while the concentrations of Fe and Mn were low in HCO3-Na groundwater (F3). Source analysis results showed that 54.3% and 26.3% of Fe were mainly affacted by F1and F3; the corresponding values for Mn were 58.7% and 19.4%. Less than 7.50% of Fe and Mn were affected by F2. In summary, the migration-enrichment effect and the natural dissolution effect of Fe and Mn oxides are the main factors leading to the excess of Fe and Mn, and hydrogeological conditions and pH are the main variables affecting the concentration of Fe and Mn in groundwater. The influence of anthropogenic activities on the concentration of Fe and Mn in groundwater in the study area is limited.
2024 Vol. 44 (9): 5016-5025 [Abstract] ( 105 ) [HTML 1KB] [ PDF 3368KB] ( 703 )
Solid Waste
5026 Effect of high-content metals on the phosphorus forms and release of sludge-derived biochar
JIANG Jia-jia, WAN Jun-li, FANG Xin, ZHANG Zi-yi, NIE Xiao-bao, SUN Shi-quan
Municipal sludge was enhanced pretreated with high-content metal and then pyrolyzed to form various sludge-derived biochar at low temperature. Pearson’s correlation analysis and characterization methods were employed to investigate the effects of high-content metal and pyrolysis temperature on phosphorus forms and phosphorus release from sludge-derived biochar. The results showed that the phosphorus release from sludge-derived biochar decreased with the increase of pyrolysis temperature, and a large amount of internal phosphorus was converted into ortho-P at 350℃. The enhanced pretreatment and pH had a greater effect on the phosphorus release and immobilization of metal element than pyrolysis temperature. Fe/Al-P and Ca-P competed for the coexistence of phosphorus, and Fe/Al-P was slightly dominant, while Ca-P had a significant effect on IP species. The ability of high-content metal to promote the conversion of OP to IP, inhibit phosphorus release, and hinder the conversion of HPO42- to H2PO4- was Fe>Al>Ca. The dominant phosphorus of calcium-based, and iron- and aluminum-based sludge-derived biochar were Ca-P and Fe/Al-P, respectively, of which Fe/Al-P was encapsulated by iron-aluminum oxides and was more difficult to release. Ca(H2PO4)2 was the primary form of phosphorus release. Fe-enhanced pretreatment has the greatest effect on the form and release of phosphorus in sludge-derived biochar, and Ca-enhanced pretreatment is conducive to the enhancement of bioavailable phosphorus, potentially providing new ideas for the resource utilization of municipal sludge-derived biochar.
2024 Vol. 44 (9): 5026-5034 [Abstract] ( 99 ) [HTML 1KB] [ PDF 1362KB] ( 917 )
5035 Hydraulic performance of HPMC modified bentonites against aggressive solution
WANG Bao, ZHOU Lin, WANG Bai-chuan, ZHU Jia-jia, ZHANG Di, ZHOU Hao-ran
Hydroxypropyl methylcellulose (HPMC) was used to enhance the hydraulic performance of natural sodium bentonite to aggressive solution. Hydraulic conductivity and free swell tests using 5000mg/L CuSO4 and 0.5mol/L H2SO4 solution were conducted to test the hydraulic performance and swell ability of the HPMC modified bentonite. The hydraulic conductivity test results show that the hydraulic conductivity of the bentonite to CuSO4 solution decreased by 32.28% to 77.40% after modification with 2% and 5% HPMC, respectively. Whereas, when permeated with H2SO4 solution, the hydraulic conductivity of the bentonite decreased by 73.42% to 92.83% when the mass loading of HPMC was 2% and 5%, respectively. When the HPMC loading reached 2%, the swell ability of the bentonite cannot be improved, whereas when the HPMC loading was up to 5%, the swell ability of bentonite can be enhanced by 2factors. These data illustrate that modification with HPMC could improve the hydraulic performance of bentonite to the aggressive solution, and the higher HPMC mass loading the higher hydraulic performance of bentonite. The improvement in the hydraulic performance should be attributed mainly to the clogging of the pore of the bentonite specimens.
2024 Vol. 44 (9): 5035-5043 [Abstract] ( 93 ) [HTML 1KB] [ PDF 3160KB] ( 744 )
5044 Assessment of carbon emissions during excavation, screening, and reuse of municipal solid waste landfill
WEI Yu-fang, XU Wen-jie, PENG Yi, CHEN Yun-min, KE Han, ZHAN Liang-tong, YU Lin-feng
This paper evaluated the carbon emissions and carbon reduction benefits of excavating, screening, and reusing landfill material, contributing to the enhancement of China’s carbon emission calculation system in the municipal solid waste treatment sector. Initially, from a process perspective, the emission and reduction factors of each process were classified and organized. Subsequently, a large municipal solid waste landfill in Eastern China was selected as the research subject, and a Monte Carlo simulation was conducted for analysis. The results indicated that the carbon reduction from landfill mining exceeded its emissions, with an average net emission of -235.22kg CO2-eq/t stale waste. Moreover, the main sources of emissions and reductions were analyzed. It was found that the incineration of light materials was a significant contributor to emissions, while the recovery of electricity and thermal energy from incineration was the primary source of emission reduction. Lastly, through the sensitivity analysis of parameters, it was discovered that energy conversion efficiency and the net reduction factor significantly influenced the reduction results.
2024 Vol. 44 (9): 5044-5052 [Abstract] ( 102 ) [HTML 1KB] [ PDF 902KB] ( 767 )
5053 Release characteristics of polycyclic aromatic hydrocarbons and dioxins during co-processing multi-source organic wastes in a coal-water slurry gasifier
CUI Chang-hao, ZHANG Lei, LIU Mei-jia, LI Li, CHEN Chao, WANG Hao-xiang, YAN Da-hai, MA Xiao-feng
Field studies were conducted to investigate the release characteristics of polycyclic aromatic hydrocarbons (PAHs) and dioxins (PCDD/Fs) during the co-processing of anthraquinone dye, distillation residue, waste activated carbon and waste organic solvents in a coal water slurry gasifier. Results indicate that co-processing organic wastes showed minimal impact on gasification parameters but altered the gas composition of CO and CO2 in syngas, in which the gas composition of CO decreased from 40.9% to 31.5%, while the gas composition of CO2 increased from 23.4% to 31.0%. The reason may attribute to the enhanced combustion facilitated by the addition of organic wastes. Naphthalene and low-chlorinated PCDD/Fs were predominant in the gaseous samples under blank and co-processing condition. Under co-processing condition, the TEQ levels of PAHs and PCDD/Fs are in the range of 0.12-0.49ng-TEQ/m3 and 1.22~3.82pg-TEQ/m3, respectively, which showed marginal increases compared to the blank conditions (0.06~0.11ng-TEQ/m3 for PAHs and 1.34~2.97ng-TEQ/m3 for PCDD/Fs), and also well below the relevant standard limits. Under co-processing condition, PAHs and PCDD/Fs in solid samples are predominantly low, medium-ring and low-chlorinated congeners. The TEQ levels of PAHs, including sulfur (0.49ng-TEQ/kg) and carbon black (0.37ng-TEQ/kg), as well as the TEQ levels of PCDD/Fs, including ammonium bicarbonate (8.3pg-TEQ/kg), are higher than those of other solid samples. Moreover, the TEQ levels of PAHs and PCDD/Fs does not significantly increase compared to blank condition, indicating lower environmental risk.
2024 Vol. 44 (9): 5053-5062 [Abstract] ( 108 ) [HTML 1KB] [ PDF 1034KB] ( 662 )
5063 Mechanisms of the effect of modified phosphogypsum on the change of heavy metal migration from sludge
DAI Qu-xiu, HU Yao, MA Li-ping, YANG Jie, GUO Zhi-ying, AO Ran, YANG Ren, ZHENG Da-long, XIE Long-gui
This study utilized a mixture of potato residues and phosphogypsum waste residue to prepare a dual-modified material (D-MPR), which was then used to treat heavy metals in sludge. The preparation conditions of the dual-modified material were studied, along with its effects on the Zeta potential of the sludge, extracellular polymeric substances (EPS), and the migration of heavy metals; the ecological risk of heavy metals in the treated sludge was analyzed, and a heavy metal migration model was constructed. Experimental results showed that the waste residue (PR) underwent etherification modification at an alkalization temperature of 50°C with 2% hexadecyl trimethyl ammonium bromide (CTAB) by PR mass, at an etherification temperature of 50°C for 3hours; subsequently, by adding 1% PR of ammonium persulfate and 80% PR of acrylamide (AM), and reacting at 50°C for 3hours for graft modification, D-MPR was prepared. By adding D-MPR at a proportion of 12‰ of the dry solids (DS) amount of the sludge to treat heavy metals, it was found that compared with the original sludge, approximately 42.43% of non-stable Cd, 60.42% of non-stable Cr, 53.10% of non-stable Cu, 67.58% of non-stable Pb, 55.21% of non-stable Zn, 34.23% of non-stable Ni, and 74.68% of non-stable As were immobilized into the sludge cake, significantly reducing the migration risk and potential ecological risk coefficients of heavy metals in the sludge cake. Furthermore, the study found that the conversion rate of non-stable heavy metals decreased with an increase in LB-EPS and TB-EPS content, and increased with an increase in Zeta potential, thereby establishing a conversion model for non-stable heavy metals. This research provides a solid research foundation for the study of sludge heavy metal treatment with solid waste-based materials and has significant practical importance for the detoxification of sludge.
2024 Vol. 44 (9): 5063-5076 [Abstract] ( 114 ) [HTML 1KB] [ PDF 2224KB] ( 649 )
5077 Exploring the construction path of “Zero-waste City” for mineral resource-based cities in China
MA Chao, FENG Yin-cheng, ZHAO Kang, TIAN Xiang-qin, NIE Jing-lei, HU Hua-long
Mineral resource-based cities play a crucial role in ensuring energy resource safety and promoting healthy economic development in our country. These cities are characterized by the generation of a large amount of solid waste, overall low utilization rate, and prominent environmental pollution issues. How to construct the “zero-waste city” for mineral resource-based cities is an important topic during the China’s “zero-waste city” construction and a key aspect of building a beautiful China. This article analyses the basic characteristics of mineral resource cities, such as distribution, classification and solid waste characteristics, and points out the challenges faced during the construction of “Zero-waste City”, including insufficient integration of management systems, inadequate legal regulations and standards, insufficient technology for the “three transformations” of solid waste, and unclear distinctions between the resource and environment attributes of solid waste. This paper also summarizes the main achievements of China’s “zero-waste city” construction and the typical experience regarding how mineral resource-based cities achieve the “Zero-waste” goal. In the process of advancing the construction of ’zero-waste cities’ in mineral resource-based cities, it is essential to learn from advanced and mature experiences, focus on top-level design, and prioritize the construction of legal regulations and standards. Simultaneously, emphasis should be placed on technological research and innovation, addressing key issues based on the actual conditions of the city, and establishing a comprehensive system for the collaborative utilization and disposal of multiple solid wastes.
2024 Vol. 44 (9): 5077-5084 [Abstract] ( 181 ) [HTML 1KB] [ PDF 533KB] ( 806 )
Soil Pollution Control
5085 Input-output inventory and risk early warning of heavy metal in farmland soil in Taihu Lake Basin, southern Jiangsu
YANG Li, DONG Xin-ping, LIN Jing, BO Wen-hao, BAI Zong-xu, CHEN Tao
In this study, a thorough inventory of heavy metal inflows and outflows in the agricultural soils of the Taihu Lake Basin in southern Jiangsu Province was meticulously compiled using publicly available data. The objective was to evaluate the current accumulation status of eight key heavy metals—arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn)—and forecast their future trends. The primary routes of heavy metal entry into the soil included atmospheric deposition, livestock manure application, irrigation water, and the use of chemical fertilizers and pesticides, while the main pathways for metals to migrate out of soil were crop removal during harvest and soil leaching processes. The findings revealed that As, Cd, Cu, Cr, and Hg mainly infiltrated the agricultural soils via irrigation water, while Ni entered through atmospheric deposition and the use of chemical fertilizers and irrigation water. Lead and Zn predominantly infiltrated through atmospheric deposition. With regard to the removal of these metals from the soil, As, Cr, Cu, Hg, and Pb were chiefly lost through leaching, whereas Cd and Zn were primarily removed via crop harvesting. Notably, Cd has emerged as the most critical heavy metal requiring attention in the agricultural soil of the Taihu Lake Basin, with the potential to exceed the threshold in the near future. The other heavy metals showed varying levels of accumulation, all remaining well below the established risk thresholds.
2024 Vol. 44 (9): 5085-5098 [Abstract] ( 149 ) [HTML 1KB] [ PDF 5176KB] ( 753 )
5099 Effects of nitrogen input on reed root exudates release and soil nitrification
ZHAO Chun-yu, WU Jia-peng, ZHANG Yu-xin, ZHAO Yi-yi, ZHANG Han, LI Xuan, ZHAO Meng-yu, MENG E
To study the effects of nitrogen input caused by human activities on the release of plant root exudates and the nitrification process of soil, in-situ soil and reed seedlings of the Yellow River Delta wetland were collected for enrichment culture experiments, and the release rate of root exudates, nitrification, as well as related physicochemical factors were measured and analyzed. The results showed that the addition of different nitrogen had different effects on physicochemical factors of soil, among which NH4Cl had the most significant promoting effect on microbial biomass carbon and nitrogen and NH4+-N content, and KNO3 addition could significantly increase soil NO3--N content, and reed litter had a stronger promoting effect on soil organic carbon and total nitrogen. Both in rhizosphere and non-rhizosphere zone, the average ammonia oxidation rate (Va) was (5.16±1.37) and (3.62±0.80) μmol/(kg·d), respectively, and the content of NH4+-N was significantly positively correlated, while the average nitrite oxidation rate (Vn) was (6.01±1.42) and (4.45±1.08) μmol/(kg·d), and the content of NO3--N was significantly positively correlated. Soil SOC, TN and Va were significantly positively correlated, which may be explained by the fact that the increase of organic matters promotes the mineralization and then provides the reaction substrates for the ammonia oxidation process. The higher index of nitrogen balance in organic nitrogen addition group also indirectly proved the promotion of mineralization. Compared with the control group, exogenous nutrients can promote the secretion of total acids, total sugars and amino acids in reed root system, with the average release rates were (169.75±31.83), (116.72±21.76) and (9.52±3.31) μg/(g·d), but significantly inhibit or have no obvious effect on phenols and flavonoids. There was a significant negative correlation between the phenols secreted by roots and Va, which was mainly attributed to the selective inhibition of phenols to ammonia-oxidizing bacteria. However, amino acids were significantly positively correlated with Va and Vn, which could provide energy and nutrients for the metabolism of nitrifying bacteria and then promote the nitrification process. In general, on the one hand, the addition of exogenous nitrogen could provide a suitable growth environment for nitrifying bacteria by directly changing the physical and chemical properties of soil. On the other hand, exogenous nitrogen also stimulated the release of root exudates, increasing the content of nutrients and active substances, and then promoted the nitrification.
2024 Vol. 44 (9): 5099-5107 [Abstract] ( 143 ) [HTML 1KB] [ PDF 718KB] ( 628 )
5108 Characteristics of soil microbial communities in typical temperate glacial debris and Retreat Zones: A case study of the Azha and Midui GlaciersYE
Xin-tong, HU Yang, LIU Qiao, LU Xu-yang, LIU Chen
This study investigates the characteristics of soil microbial communities and the impact of soil chemical properties in the glacier moraine and retreat zones of the Azha and Midui Glaciers in southeastern Tibet, using bacterial 16S rRNA gene amplicon sequencing and fungal ITS sequencing technologies. The results show that a total of 38bacterial phyla were found in the soil of both glacier moraine and retreat zones, with Proteobacteria (40%), Actinobacteriota (23%), and Bacteroidota (14%) being the dominant groups. Seven fungal phyla were identified, with Basidiomycota (47%) and Ascomycota (45%) being the dominant groups. Significant differences were observed in the abundance of Patescibacteria, RCP2-54, Bacteroidota, Gemmatimonadota, and Acidobacteriota between the moraine soils of Azha and Midui Glaciers. Significant differences in microbial community structure and abundance were found between the moraine and retreat zone soils of the Midui Glacier (P<0.05), while no significant differences were observed among the three successional stages within the retreat zone. Microbial communities adapted to extreme environments were most abundant in the moraine, while the abundance and diversity of microbial communities involved in plant colonization or symbiosis with plants significantly increased with succession. The α-diversity of microbial communities increased, and the NMDS model gradually approached overlap, indicating that community structure tended to stabilize in the late stages of vegetation succession. Nutrient content, except for total potassium, was low in both glacier moraine soils. As vegetation succession progressed, soil pH gradually decreased while nutrients gradually increased, with the late succession stage showing significantly higher nutrient levels than the earlier stages. Microbial communities in the moraine soils were significantly positively correlated with pH and total potassium (P<0.05), whereas in the retreat zone soils, they were significantly positively correlated with available potassium, nitrate nitrogen, total phosphorus, and soluble organic carbon (P<0.05), with phosphorus limitation being predominant.
2024 Vol. 44 (9): 5108-5121 [Abstract] ( 134 ) [HTML 1KB] [ PDF 2368KB] ( 874 )
5122 Effect of different modified biochar treatments on nitrogen loss and rice yield in paddy fields
YI Ben-ji, LIU Chang, HAN Hong-wei, ZHANG Feng, CHEN Tao-tao, MENG Jun, CHI Dao-cai
In order to further explore the potential of biochar in rice ecosystems for efficiency, fertilizer savings and emission reduction, six treatments of maize stover biochar (B), acidified biochar (BpH), nitrogen-loaded biochar (BNH4), iron-modified biochar (BFe) and calcium-modified biochar (BCa) were set up in a 2-year experiment using no biochar as the control (CK) to study the cation exchange capacity (CEC) of the biochar, the oxygen-containing functional groups, as well as rice yield, nitrogen extraction, ammonia volatilization, nitrogen leaching and soil nitrogen residues under their treatments were investigated. The results showed that BpH, BNH4 and BFe significantly increased the CEC of biochar (53.9%, 29.6% and 28.2%) compared with B. All four modified treatments significantly increased the concentration of oxygenated functional groups, such as -COOH, -OH, C=O, and O-H, to enhance the nitrogen uptake capacity of biochar. The cumulative ammonia volatilization ranged from 9.1 to 19.9kg/hm (2021) and 8.49 to 13.7kg/hm (2022) over the whole reproductive period, and except for BNH4, which had a significant ammonia reducing effect (44.6%), B, BpH, BCa, and BFe had no significant effect on ammonia volatilization in the first year; whereas, BCa, BNH4, and BFe all significantly reduced ammonia volatilization by 33.5%, 37.5% and 37.8%, respectively, compared to CK. The four modified biochars reduced nitrogen leaching by 19.0% and 35.2% (BpH), 15.0% and 21.0% (BCa), 11.3% and 28.7% (BNH4), and 12.6% and 29.0% (BFe) compared to CK in 2consecutive years. B had no significant effect on yield in year 1effect in year 1, but significantly increased yield (8.8%) after 1year of aging; BpH and BNH4were both effective for 2consecutive years, increasing yield by 19.7% and 12.2% (2021), and 11.49% and 5.8% (2022), respectively. BpH, BCa, and BNH4significantly reduced reactive nitrogen emissions in 2 years, with reductions of 23.4%, 21.8% and 42.3% (2021) and 23.5%, 30.5% and 35.5% (2022); BFe 2a had a mixed effect, with a 25.9% enhancement in year 1and a 35.6% reduction in year 2. There were no significant differences in soil mineralized N residuals between biochar treatments in year 1; however, BCa, BNH4, and BFe showed significant efficiency gains in year 2. When considering yield increases, reactive nitrogen reduction and mineralised nitrogen sustainability simultaneously, the best results for BpH and BNH4combined were achieved during the two-year trial, reducing ammonia volatilisation by 23.4% and 42.3% (2021), 23.5% and 35.5% (2022), NH4+-N leaching by 18.9% and 10.6% (2021), 35.4% and 29.0% (2022), NO3--N leaching 15.6% and 14.7% (2021), 24.5% and 23.4% (2022), nitrogen accumulation 1.1% and 13.4% (2021), 14.8% and 4.3% (2022) and mineralised nitrogen residues 1.3% and 15.0% (2021), 12.2% and 17.9% (2022), and finally 19.7% and 12.2% (2021), 11.5% and 5.7% (2022) rice yield increase, compared to CK.
2024 Vol. 44 (9): 5122-5133 [Abstract] ( 107 ) [HTML 1KB] [ PDF 1475KB] ( 810 )
Environmental Ecology
5134 Vegetation responses to extreme meteorological drought event of 2022 in the Yangtze River Basin
ZHAO Qian-zuo, ZHANG Xuan, FEI Jun-yuan, XU Yang, LI Chong, HAO Fang-hua
A method for assessing vegetation sensitivity and vulnerability to meteorological droughts was proposed in this study. Standardized indices were developed based on precipitation, evapotranspiration, and solar-induced chlorophyll fluorescence data. The sensitivity of vegetation to meteorological drought was quantified by using Correlation Coefficient (CC), Response Time scale (RT), and Response Sensitivity (RS), while vulnerability was assessed by Duration Response Ratio (DRR) and Intensity Response Ratio (IRR). The results indicated that in the vegetation response assessment for meteorological drought of 2022 in Yangtze River Basin, (1) Low sensitivity (median CC=0.36, 0.44; median RS=-1.72, -1.58) was observed in evergreen needleleaf forest and grassland exhibited of upstream region. Whereas, the highest sensitivity (median CC=0.68, median RS=-1.37) was shown in cultivated land, and the sensitivity of (woody) savannas surpassed that of forests (median CC: forests=0.41~0.49, woody savanna=0.64, savanna=0.61; median RS: forests=-1.61~-1.57, woody savanna=-1.44, savanna=-1.40) in the middle and lower reaches. (2) The vulnerability of evergreen needleleaf forest was obviously higher than that of other forests (median DRR: needleleaf forest=1.04, other forests=0.85~0.97; median IRR: needleleaf forest=0.94, other forests: IRR=0.76~0.88). Meteorological drought was found to have a greater impact on grasslands than on (woody) savannas in the middle and lower reaches (median DRR: grassland=1.28, woody savanna=0.74, savanna=0.88; median IRR: grassland=1.24, woody savanna=0.74, savanna=0.80). Low vulnerability was exhibited in cultivated land (median DRR=0.77, IRR=0.72). (3) the Jinsha River basin, with the high average elevation, was identified as high vulnerability hotspot, while the Sichuan Basin and the Han River basin were high sensitivity hotspots due to the aggregated croplands. Therefore, to prevent further degradation and irreversible damage, vegetation monitoring and restoration strategies should be conducted according to various responses of vegetation to meteorological drought.
2024 Vol. 44 (9): 5134-5144 [Abstract] ( 135 ) [HTML 1KB] [ PDF 3644KB] ( 682 )
5145 Analysis on spatio-temporal distribution characteristics and tradeoff-synergy of ecosystem services in the FAST Tranquility Zone
QUAN Xiao-ya, SU Wei-ci, GOU Rong, HUANG Xian-feng
Based on the InVEST and CASA models, an assessment was conducted on four ecosystem services—Net Primary Productivity (NPP), water conservation, soil retention, and habitat quality in the FAST Tranquility Zone from 2000 to 2020. This involved calculating these services, analyzing their spatiotemporal variations at different scales, identifying hotspots of ecosystem services, and using tradeoff-synergy index and Random Forest models to reveal the relationships and intensities of tradeoff/synergy among these services and with their driving factors. The results showed that: (1) From 2000 to 2020, the overall ecosystem services in the FAST Tranquility Zone demonstrated an increasing trend, with NPP rising by 730.544gC/m2, water conservation by 5.925mm, habitat quality score by 0.007, and soil conservation by 0.295t/km2. (2) There were notable differences among the circles; the core area showed the fastest increase and had the best service functionality, followed by the remote areas with significant ecological improvement, and lastly the middle area where ecological restoration was relatively slow. (3) Among land use types, woodland and grasslands had the greatest promotional effect on the ecosystem services in the study area. (4) Overall, the ecosystem service hotspots transitioned from class I and II hotspots to non-hotspot areas, class III hotspots, and class IV hotspots. (5) The relationships among the four ecosystem services within the area were predominantly synergistic, with increasing synergy over time, and in some regions, tradeoff effects were evident between water conservation and both soil conservation and NPP. (6) The main driving factors for the tradeoff/synergy relationships among the four ecosystem services in the FAST Tranquility Zone were precipitation, evapotranspiration, sensitivity to rocky desertification, slope, and human activity intensity
2024 Vol. 44 (9): 5145-5159 [Abstract] ( 102 ) [HTML 1KB] [ PDF 8248KB] ( 821 )
5160 Community structure and denitrification function of Photinia phyllosphere bacteria in Zhengzhou City
GU Li-kun, ZHANG Jian-yun, XU Hao, HOU Zhi-kang, SHAO Shuang-shuang, ZHANG Man, ZHONG Shao-pan, BAI Zhi-hui
In this study, 16S rRNA high-throughput sequencing technology was used to analyze the diversity and richness of the phyllosphere bacterial community, and PICRUSt2 software was used to predict the nitrogen metabolism and other functional genes of the phyllosphere bacteria based on the gene sequencing results, and the denitrification rate of the phyllosphere bacteria was measureed. The results showed that Proteobacteria, Actinobacteria, and Bacteroidetes were the dominant phyla in the phyllosphere bacteria of Photinia plants, and Achromobacter, Burkholderia-Caballeronia-Paraburkholderia, and Hymenobacter were the dominant genera, and the dominant bacteria were the same at different locations in the same region. In addition, it was also found that Achromobacter, Massilia, and Sphingomonas, which have denitrification functionsthere, distributed in the phyllosphere of Photinia. The PICRUSt2prediction showed that the metabolic function pathway is dominant of the 6primary functional layers of phyllosphere bacteria, and the membrane transport function is dominant in the 30 secondary functional layers. Meanwhile, the abundance of denitrification related genes is the highest among nitrogen metabolism functional genes, and the abundance of nitrogen fixation related genes is the lowest. The measured denitrification rate of phyllosphere bacteria is (22.2 ± 1.7)-(33.2 ± 4.7) μg/(g·h).
2024 Vol. 44 (9): 5160-5168 [Abstract] ( 113 ) [HTML 1KB] [ PDF 1849KB] ( 1022 )
5169 The relationship of typical grassland species-area based on drone and ground surveys
ZHU Sa-ning, GAO Ji-xi, WAN Hua-Wei, YOU Chun-he, YANG Xue, GUO Yu-tong, ZHU Chen-jia, LV Na
This study focuses on the typical grasslands of Hulunbuir City as the research subject, conducting a systematic evaluation of the differences between traditional ground quadrat surveys and unmanned aerial vehicle (UAV) surveys of grassland plant species. This was achieved by investigating and analyzing the relationship between quadrat area and the number of species within those quadrats. The study determined the minimum survey areas for both ground and UAV surveys in typical grasslands. The findings are as follows: 1) The number of species in typical grasslands has a nonlinear relationship with the survey area, and the "species-area" relationship can be described by the model S=aln(bA+1), where S represents the number of species, A is the area, and a and b are constants. Using the combined sampling method, at least 8 1m2 small quadrats should be included to represent 80% of the species. Based on the nested sampling method, the minimum survey area required is 8.63m2; 2) For typical grasslands, the average species discovery rate of UAV surveys was 81.7% compared to traditional ground survey methods. UAVs can serve as an auxiliary tool for ground surveys to enhance survey efficiency; 3) In monitoring species within typical grasslands, one or two combined quadrats can be chosen, supplemented with 4 to 5 random shots using a UAV. This approach can identify 84.7% to 88.3% of the total number of species in typical grasslands. Compared to the traditional method of conducting 3 to 5 repeated quadrat surveys, this method offers stronger representativeness and higher work efficiency.
2024 Vol. 44 (9): 5169-5179 [Abstract] ( 113 ) [HTML 1KB] [ PDF 935KB] ( 765 )
5180 Species diversity, biomass, and their relationship in the mountainous areas of Beijing
ZHANG Qiang, LI Ling-jun, CHEN Yun-run, LU Hai-feng, LIU Bao-xian, ZHAO Wen-hui, SU Ri-na
The relationship between species diversity and ecosystem function is one of the key issues in ecological research. Biomass is an important modality of ecosystem function. This study investigated 151 forest plots in the mountainous areas of Beijing, in order to understand the species diversity, biomass, and their relationship of the temperate secondary forest communities in Beijing. The results showed that the investigated plants belong to 399 species under 228 genera and 91 families. The vertical structure of forest communities was clearly stratified, and the species diversity of different layers generally presented that tree layer was the lowest, while shrub layer and herb layer were relatively close. Among the 9 forest community types, the species richness of Populus davidiana, Juglans mandshurica, Betula dahurica and Larix principis-rupprechtii communities were relatively high, followed by the Betula platyphylla and Quercus mongolica communities. The Pinus tabuliformis, Quercus variabilis and Tilia mongolica communities were relatively low, with an average number of plant species under 29. The aboveground biomass of forest communities varied from 3.00~25.00kg/m2, with an average of 12.73kg/m2. The biomass density of coniferous forest was higher than that of broad-leaved forest, with a values of 15.92kg/m2 and 11.46kg/m2, respectively. The age structure of forests were mainly middle-aged forests, which have significant carbon sequestration potential in the future. Species diversity displayed a significantly negative correlation with biomass. However, the effect of species diversity on biomass mainly through their shared effects with species properties and environmental factors, and the independent effect of species diversity was quite weak. Because the relationship between species diversity and biomass can be strongly confounded by covarying biotic and abiotic factors, we suggest that the efffects of environmental factors, species properties and management practices on biomass should be comprehensively considered in future research.
2024 Vol. 44 (9): 5180-5191 [Abstract] ( 122 ) [HTML 1KB] [ PDF 1973KB] ( 512 )
5192 Evaluating the changes and driving factors of carbon storage using the PLUS-InVEST Model: A case study of Napa Sea Basin
ZHANG Shuang, GAO Qi-chen, ZHANG Rong, SONG Chen-hui, LI Zhong-fei
Taking the Napa Sea basin as the study area, by using the PLUS-InVEST model and geographic detector methods. Providing a scientific understanding on change pattern of carbon sink function in this basin, evolution patterns of spatial and temporal driving factors of carbon storage were studied over the past 20 years, and the evolution tendency were predicted in future under four kinds of different scenarios based on the PLUS-InVEST model in Napa Sea Basin. The results showed: (1) From 2000 to 2020, water area and construction land respectively increased by 143.98% and 451.86%, and farmland and grassland respectively decreased by 61.37% and 20.53%. Farmland and grassland was mainly transferred to construction land, some grassland transferred to forest land. (2) In the past 20years, carbon storage showed a downward trend, with a total decreased of 0.63×106 tons. Decline of grassland and farmland and increase of construction land were the main reasons for decrease of carbon storage in the basin. (3) Compared carbon storage under different scenarios in 2020with in 2035, its will increase under two kinds of scenarios except for the natural development and cultivated land protection scenario, and total carbon storage will be respectively 18.11×106t, 18.17×106t, 18.31×106 and 18.29×106t for each scenario. (4) DEM (0.533), mean annual temperature (0.442), and NDVI (0.365) were the dominant factors driving the evolution of carbon storage in the basin. (5) The interaction effects among the driving factors was stronger than that of single factors, and synergistic effect of DEM and NDVI (0.633) was the strongest. The results can provide data support for how to improve rationality of land use and function of carbon sink scientifically in Napa Sea Basin.
2024 Vol. 44 (9): 5192-5201 [Abstract] ( 224 ) [HTML 1KB] [ PDF 1368KB] ( 906 )
Emerging Contaminants
5202 Analysis of science and technology need for emerging contaminants control in China
WU Hui-hui, ZHI Yan, XIAO Qing-cong, XU Wei-pan, ZHANG Yan-shen, YU Fang
The management of emerging contaminants is a long-term, complex, and challenging task. To support the well implementation of emerging pollutant control actions, it is urgent to conduct major scientific and technological special projects. The establishment process of risk prevention based management framework for toxic and hazardous chemicals in developed countries and regions like the United States and the European Union was introduced, from the aspects of emerging contaminants screening, monitoring, risk assessment, alternative and treatment technology, and risk control. Meanwhile, the history, achievements, and gaps in the governance of emerging contaminants in China were reviewed. Based on the current situation and existing problems of emerging contaminants control in China, we proposed a five-step management framework of “screening-evaluation-treatment- control-demonstration” to address the technical bottleneck of emerging contaminants management using a stepwise manner, constructed a whole process collaborative governance and risk management system for emerging contaminants, and completed the standard system for emerging contaminant control and management, so as to steadily improve the management level of emerging contaminants.
2024 Vol. 44 (9): 5202-5208 [Abstract] ( 133 ) [HTML 1KB] [ PDF 925KB] ( 1058 )
5209 Risk assessment of antimicrobial resistance
LI Hong-na, YANG Zhen-zhen, HE Xiao-jia
The effectiveness of antimicrobial drugs is threatened by the increasing antimicrobial resistance (AMR). The development process of AMR risk assessment is systematically reviewed both domestically and internationally, and the general assessing processes and commonly used methods are summarized and analysed in this work as well. From the viewpoint of the government agency, only qualitative risk assessments can be conducted for specific drug-resistant bacteria or genes using models currently, which is mainly due to the lack of key variable data related with AMR in the environmental medium. As to the perspective of scientific research, the risk assessment of AMR has been continuously improved. It evolved from focusing on single drug-resistant bacteria, mobile genetic elements, drug-resistant genes, or virulence factors to paying attention to their co-occurrence integrally. Furthermore, comprehensive assessments based on the weights of drug-resistant bacteria and antibiotic resistance genes are also regarded. Based on the above analysis, this study concludes the main problems in current risk assessment of AMR. Moreover, challenges are put forward including lack of dose-response models, genotype control, and monitoring data acquisition of AMR. These findings will provide basic support for risk assessment and control of AMR in China.
2024 Vol. 44 (9): 5209-5221 [Abstract] ( 111 ) [HTML 1KB] [ PDF 2498KB] ( 1988 )
5222 Upcycling PET microplastics via alkaline hydrolysis to defective iron metal-organic frameworks for water treatment
JIANG Wen-bin, JIANG Chen-chen, WEI Xuan-xiang, XU Li-cong, WANG Shan-li, HASAN Md-Shahib, WU Ming-hua, YU De-you
In order to effectively remove polyetylene terephthalate (PET) microplastics, the PET microplastics were alkaline hydrolysed and upcycled to defective iron metal organic frameworks (Fe-MOFs) for the treatment of printing and finishing wastewater. The results showed that the removal rate of PET microplastics reached 100% with 97.4% yield of sodium terephthalate (Na2TPA) at the conditions of 2mol/L NaOH, 120℃ hydrolysis temperature of, and 120min reaction time.. Two facile methods using PET microplastics hydrolysates as precursors were developed for the preparation of defective Fe-MOFs catalysts. Scanning electron microscopy (SEM), powder X-ray diffractometer (XRD), Fourier transform-infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) techniques were employed to characterize the morphologies, crystal structures, molecular structures, and elemental compositions of resultant catalysts. Finally, their catalytic ozonation performances was further evaluated and compared by the degradation of AO-7. The results revealed that D-Fe-MOF could completely remove AO-7 within 3 min at a degradation rate constant of 0.926 min-1, which was 3.6 and 7.3-fold times higher than those of W-Fe-MOF and ozonation alone process.
2024 Vol. 44 (9): 5222-5233 [Abstract] ( 107 ) [HTML 1KB] [ PDF 2767KB] ( 687 )
5234 Flotation separation of microplastics in water: Principle, effect, mechanism and regulation
ZHAO Yi-jin, WANG Yan-ge, RUI Jun-nan, QIU Yu-ping
Flotation technology offers an effective method for separating microplastics (MPs) from water. The process involves the adhesion of fine air bubbles and MP particles, forming bubble-particle combinations with a lower apparent density than water, which results in their floatation to the surface. This study examines the principles, methods, and characteristics of flotation, traces its classification and application, provides a systematic explanation of the interactions between bubbles and MP particles during flotation, compares the differences in the efficiency of removing MPs between traditional air flotation and enhanced air flotation, discusses the effects of the properties of air bubbles and MPs on flotation based on the principle of flotation, and elucidates how environmental conditions of water affect the separation efficiency of MPs.
2024 Vol. 44 (9): 5234-5247 [Abstract] ( 139 ) [HTML 1KB] [ PDF 908KB] ( 832 )
Carbon Emission Control
5248 Advances in microbial fixation and conversion mechanisms of carbon dioxide derived from steel off-gas
LU Jia-ying, WANG Yu-ming, LI Xian-wei, XIONG Li-jun, LI Dan
The steel industry plays a pivotal role in economic development. However, it stands as a significant contributor to large-scale CO2 emissions. Based on the backdrop of global climate change, it is imperative and urgent to reduce CO2 emissions to alleviate global climate changes and strive for sustainable development. Genetically engineered bacteria exhibit a remarkable capacity to assimilate CO2 via regulation of genes of interest, rational design of metabolic pathways, and optimization of bioprocesses. They allow the upcycling of CO2 into high-value-added products, such as organic acids, biofuels, and polyols, offering an innovative solution for the transitioning from the linear “acquisition-manufacturing-processing” economy to a circular economy with diminished carbon footprints. Consequently, this study highlights the research advancements concerning the microbial fixation/conversion of CO2 derived from steel off-gas. This review systematically summarizes the theoretical frontiers and engineering challenges and emphasizes the pivotal role of gene editing technology. The advancements in this field not only provide a new avenue for the reduction of CO2 emission and environmental protection but also pave a path with future innovations towards the attainment of sustainable development goals.
2024 Vol. 44 (9): 5248-5262 [Abstract] ( 119 ) [HTML 1KB] [ PDF 1487KB] ( 2069 )
5263 The impact of digital economy on industrial carbon emission performance: Threshold effect analysis of heterogeneous environmental regulations
LI Bai-tong, LI Jian, TANG Yan, XIA Mei-jun
Given the backdrop of heterogeneous environmental regulations, investigating the influence of the digital economy on industrial carbon emission performance assumes paramount significance. Leveraging panel data spanning 2011 to 2020 from 30 provinces, and employing administrative order, market incentive, and public participation environmental regulations as threshold variables, we construct a bi-directional fixed-effect model and a panel threshold regression model to scrutinize this relationship. Our findings reveal that while the digital economy can enhance industrial carbon emission performance, its efficacy is contingent upon the regulatory landscape. Across different types and intensities of environmental regulations, the impact of the digital economy varies. Regional analysis underscores this variability: in the eastern region, the digital economy’s impact peaks under the threshold of market-incentive environmental regulation, transitioning from inhibitory to promotional effects pre- and post-threshold. Conversely, in the central region, the digital economy’s impact peaks under the threshold of public participatory environmental regulation, transitioning from promotional to inhibitory effects pre- and post-threshold. In western China, the digital economy’s impact peaks under the threshold of administrative order environmental regulation, exhibiting its strongest effect within the threshold. Consequently, policymakers are urged to craft a diverse environmental regulatory framework and leverage digital economy development to enhance industrial carbon emission performance, tailored to regional characteristics.
2024 Vol. 44 (9): 5263-5274 [Abstract] ( 123 ) [HTML 1KB] [ PDF 544KB] ( 1242 )
Environmental Toxicology and Environmental Health
5275 The neurotoxic effects and mechanisms of titanium dioxide nanoparticles
LIU Chao-yang, FANG Yan-yan, ZHANG Zhi-bing
The toxicological effects and mechanisms of different crystal forms (anatase, rutile, mixed) and particle sizes (25, 50, 100nm) of titanium dioxide nanoparticles (TiO2-NPs) on dopaminergic cells were thoroughly investigated using SH-SY5Y cells and PC12 cells as experimental models. The results showed that rutile TiO2-NPs exhibited pronounced toxic effects, followed by mixed and anatase TiO2-NPs. Furthermore, smaller particle sizes were associated with greater toxicity to nerve cells, particularly at 25nm. The neurotoxicity was related to the induction of reactive oxygen species (ROS) generation and apoptosis. The Western Blotting analysis revealed that TiO2-NPs upregulated the levels of Bax and Cytochrome C, downregulated the expression of Bcl-2, and activated Caspase-3, indicating that TiO2-NPs induced apoptosis of dopaminergic cells by affecting the expression of proteins related to mitochondrial apoptosis pathway.
2024 Vol. 44 (9): 5275-5285 [Abstract] ( 114 ) [HTML 1KB] [ PDF 5197KB] ( 1034 )
5286 Evaluating dermal exposure to organochlorine pesticides among petrochemical workers based on skin wipe sampling
GUO Jian, LUO Xiao-jun, ZENG Yan-hong, MAI Bi-xian
This study assessed the dermal exposure to organochlorine pesticides (OCPs) in 30 petrochemical workers from Maoming, a prototypical petrochemical and agricultural city in South China, with an equal gender distribution. Swipe samples from exposed skin areas, such as foreheads and palms, and cloth-covered regions, including forearms and calves, were analyzed using gas chromatography-mass spectrometry (GC-MS). The investigation detected 10 OCPs with frequencies ranging from 1.7% to 57%, with Hexachlorocyclohexane (HCH) occurring more frequently (35%) than dichlorodiphenyltrichloroethane (DDT) (5.3%). OCPs concentrations varied significantly (P<0.0001), with levels ranging to 3050ng/m2, in descending order from forehead, to palms, forearms, and finally calves. Dermal absorption doses (DADderm) and hand-to-mouth exposure doses (DADoral) were predominantly attributable to HCH, which contributed more than 60% of the exposure, and ranged up to 13ng/(kg·d) and 0.24ng/(kg·d), respectively. The head and neck areas were the most substantial contributors to DADderm (87%). Despite slightly higher exposure levels in females, the differences were not statistically significant (P>0.05). Health risk assessments indicated that cancer risks from exposure were within safe limits (<10-4), although females exhibited a marginally higher risk.
2024 Vol. 44 (9): 5286-5292 [Abstract] ( 89 ) [HTML 1KB] [ PDF 522KB] ( 685 )
Environmental Microbiology
5293 Characterization of a bifunctional strain with crude oil degradation and biosurfactant production
LI Ya-jun, ZHANG Ning, ZHANG Peng-fei, ZHANG Rui-Chang, ZHOU Ming, ZHANG Chun-fang, WEI Xue-feng
A biosurfactant (BS)-producing strain YY-1, which was isolated from high-salt oily wastewater, was identified as Shewanella based on morphological, physiological, biochemical characteristics and 16S rRNA gene sequences analysis. The critical micelle concentration of the BS secreted by Shewanella sp. YY-1 was 700mg/L, the surface tension was 30.76mN/m, and the BS showed good chemical stability over a wide range of salinity (10~100g/L), temperature (25~100℃) and pH (2~10). The extracted BS were identified as phospholipids according to thin-layer chromatography, fourier infrared spectroscopy and gas chromatography- mass spectrometry. The results of bioremediation of crude oil wastewater with strain Shewanella sp. YY-1 showed favourable degradation performance. The removal efficiency of short-chain alkanes (C8~C10), medium-chain alkanes (C11~C20), and long-chain alkanes (C21~C44) were 74.70%, 96.68%, and 99.42%, respectively. This study could provide excellent strain resource and theoretical basis for the bioremediation of crude oil wastewater with BS-producing bacteria.
2024 Vol. 44 (9): 5293-5302 [Abstract] ( 93 ) [HTML 1KB] [ PDF 1522KB] ( 781 )
5303 Denitrifying anaerobic methane oxidation microorganisms in shale gas flowback water ― Community structure and key influencing factors
LI Xin-yue, LU Pei-li, LIU Jun, LI Shi-kang, HOU Zheng-ming, DING A-qiang
In this study, we investigated the presence of denitrifying anaerobic methane oxidizing microorganisms in high temperature, high pressure and high salt shale gas flowback water for the first time, along with their correlation with key environmental factors. The results indicated that DAMO archaea and bacteria were detected in all the seven shale gas flowback water, and the archaea exhibiting significantly higher abundance compared to bacteria with 16S rRNA gene copy ranging from 4.32×104～ 5.83×105copies/L and 1.16×103~6.00×103 copies/L, respectively. Additionally, the functional genes mcrA and pomA of DAMO archaea and bacteria were also detected in all the samples. Four representative OTUs of DAMO bacteria and one representative OTU of DAMO archaea were identified in the shale gas flowback water. Despite the high salinity, the DAMO bacteria and archaea detected in flowback water shared a closer genetic relationship to those reported in freshwater environments. RDA correlation analysis revealed that the influence of physicochemical factors in flowback water on DAMO microorganisms was more evident in microbial function rather than microbial abundance. The abundance of pmoA gene was positively and significantly correlated with TOC content, while the abundance of mcrA gene was positively correlated with the concentrations of NO3-, NH4-, PO43-, and Cl-, with Cl- having the greatest impact. These results of the study expanded the understanding of the environmental distribution of DAMO microorganisms, providing a theoretical foundation for controlling greenhouse effect caused by methane emissions in flowback water, and contributing to a deeper comprehension of microbial processes in deep shale formations.
2024 Vol. 44 (9): 5303-5312 [Abstract] ( 107 ) [HTML 1KB] [ PDF 1534KB] ( 808 )
Environmental Impact Assessment and Management
5313 Environmental benefits of waste refrigerator recycling based on IMPACT WORLD+
HUANG Yin, YU Xi, HUANG Yao, QIN Jin-chuan, CHEN Meng-jun
Waste electrical and electronic equipment (WEEE) is a kind of solid waste with large quantity and rapid growth. The WEEE recycling system established by China has become an important measure to achieve carbon neutrality. However, the environmental benefits of the recycling system are yet unclear. In this study, the IMPACT WORLD+ method was used to assess the environmental benefits of the system quantitatively based on the damage indicators of various environmental impacts. The results showed that the total damage indicators of refrigerator recycling were -18803.857EUR2015 where the damage indicators of human health and ecosystem quality were -10592.501EUR2015 and -8211.357EUR2015, respectively. In that case, the environmental benefits were equivalent to 18803.857EUR2015. Therefore, it was estimated that the environmental benefits of refrigerators recycling of the Chinese WEEE recycling system could reach 1.282 billion EUR2015 in 2021. The research indicated that the environmental benefits of WEEE recycling were significant to provide new assistance for the sustainable development of the WEEE recycling industry.
2024 Vol. 44 (9): 5313-5320 [Abstract] ( 128 ) [HTML 1KB] [ PDF 1722KB] ( 859 )
5321 Inter-sectoral transmission mechanism of greenhouse gas emissions driven by catering consumption in China
MO Xin, ZHONG Qiu-meng, LIANG Sai
Based on the environmental input-output model, structural path analysis, and betweenness centrality method, the inter-sectoral transmission mechanism (including key supply chain paths and critical transmission sectors) of greenhouse gas (GHG) emissions driven by catering consumption in China was uncovered. The results showed that (1) the GHG footprint of China’s catering consumption increased with fluctuations during 2002~2020. The top two supply chain paths with the largest contributions to the GHG footprint of China’s catering consumption were “animal husbandry → slaughtering and meat processing → catering → urban consumption”, and “animal husbandry → catering → urban consumption”. Most of the critical supply chain paths started in the three sectors including cultivation, animal husbandry, and electricity and heat production. The key supply chain paths and related starting sectors were the hotspots of policy decisions on catering industry’s low-carbon development. (2) The top three critical transmission sectors for catering industry’s GHG footprint were slaughtering and meat processing, cereal processing, and vegetable oil processing. In 2020, they transmitted 12.2, 8.0, and 7.0Mt CO2-eq of embodied GHG emissions along the catering industry’s supply chains, respectively. More attention should be paid to the productivity improvement in these sectors to reduce the catering industry’s GHG footprint. (3) The transmission roles of cereal processing, and electricity and heat production gradually increased during 2002~2020.
2024 Vol. 44 (9): 5321-5328 [Abstract] ( 134 ) [HTML 1KB] [ PDF 951KB] ( 985 )
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