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  Current Issue
 
2023 Vol.43 Issue.6,Published 2023-06-20
Air Pollution Control
Water Pollution Control
Solid Waste
Soil Pollution Control
Environmental Ecology
Environmental Toxicology and Health
Carbon Emission Control
Air Pollution Control
2673 High-resolution characteristics of NH3 emission from 2010 to 2020 in China based on satellite observation
CHEN Pei-lin, XIAO Xin-xin, WANG Qin-geng
Based on the IASI satellite observation from 2010 to 2020, the NH3 emissions in China (with a resolution of 0.25°×0.25°) were estimated by the emission flux method. The spatiotemporal distributions as well as the long-term trends of NH3 emissions were analyzed. The results showed that the average annual emission and the overall emission intensity of NH3 in China from 2018 to 2020 were 18.61 Mt and 1.93t/km2, respectively. The NH3 emissions in China increased from 12.68Mt in 2010 to 20.75Mt in 2020, with a linear growth rate of 815.10kt/a and a relative growth rate of 5.43%/a. Meanwhile, the proportion of the area with emission intensity exceeding 3.00t/km2 to the total land area of China increased from 4.88% to 20.08%. Areas with high emission intensity were mainly located in the North China Plain and the Chengdu-Chongqing area. Seasonal variation of the NH3 emissions is remarkable. The emissions in spring, summer, autumn, and winter respectively accounted for 25.92%, 36.55%, 19.61%, and 17.92% of the total annual emission. Three main patterns were observed based on the monthly variation of NH3 emissions: (1) Tibet, Inner Mongolia, and parts of northeast and northwest China, where animal husbandry is the main sector, showed a two-peaks pattern (with peaks in winter and summer); (2) Fujian, Taiwan, and a majority part of South China, where double cropping is dominated, also showed a two-peaks pattern (with peaks in spring and summer);(3) A single-peak pattern (with the peak in summer) was found in the rest regions of China. The growth of NH3 emission in the North China Plain was the fastest, followed by the Chengdu-Chongqing area, while in the northeast, northwest, and southwest regions except Chengdu-Chongqing area, the growth was relatively slow. Non-agricultural sources such as industry and transportation sectors have become more important in contributing to the NH3 emission in China. The industrial NH3 escape and vehicle emissions may be the main reasons for the rapid growth of NH3 emissions in China in recent years. Considering NH3 is one of the main sources of PM2.5, it is suggested to consider the spatiotemporal differences of NH3 emissions in relevant policy-making for PM2.5 pollution control.
2023 Vol. 43 (6): 2673-2682 [Abstract] ( 464 ) [HTML 1KB] [ PDF 1203KB] ( 1789 )
2683 Effects of sea-land exchange on ozone and secondary aerosols in Mount Lao
ZHANG Ji, HUANG Liu-bin, ZHAO Min, SUN Yue, ZHAO Feng, CHEN Tian-shu, LIU Yu-hong, LI Hong-yong, SHAN Ye, MU Jiang-shan, JIANG Yue-ru, WANG Xin-feng, ZHU Yu-jiao, SHEN Heng-qing, DONG Can, WANG Wen-xing, XUE Li-kun
To investigate the influence of multiscale sea-land exchange on surface ozone (O3) and secondary aerosols in coastal China, a comprehensive field campaign was carried out at Mount Lao in the spring of 2021. By employing the HYSPLIT model, the air masses can be divided into three types, i.e., Continental, Marine, and Mixed types, according to their total length of crossing oceans. The probabilities of these air masses were 44.5%, 35.6%, and 19.9%, respectively. Compared to Marine and Mixed types, the net photoproduction of O3 was more active under the control of Continental air masses, which can be up to 9.12×10-9h-1. The high-concentration night-time ozone under Continental and Mixed air masses controlled were related to sea-land breezes and ozone input from ocean regions, respectively. Furthermore, the difference in the composition of fine particulate matter (PM2.5) under the control of different air masses types was also investigated. NO3– was the dominant water-soluble inorganic ions (WSIIs) in PM2.5 for Continental air masses, which may be attributed to the promoted NO3– formation by the high concentration of NH4+. SO42– was the dominant WSIIs for Marine air masses, owing to the promoted SO42– formation resulting from the higher relative humidity. These results confirmed the significant differences in the characteristics of atmospheric secondary pollutants in coastal areas under the control of different air masses.
2023 Vol. 43 (6): 2683-2693 [Abstract] ( 315 ) [HTML 1KB] [ PDF 4293KB] ( 1252 )
2694 Characteristics of anthropogenic and biogenic VOCs emissions and their potential impacts on O3 and SOA in the Yangtze River Delta region
ZHANG Ming-ming, SHAO Min, CHEN Pei-lin, GU Chen, WANG Qin-geng
Focusing on the Yangtze River Delta (YRD) region (including Jiangsu, Anhui, Zhejiang provinces, and Shanghai municipality), differences in the total emission amount, species composition, and spatiotemporal distributions between anthropogenic VOCs (AVOCs) and biogenic VOCs (BVOCs) were analyzed. The contributions of the VOCs from different sources to ozone (O3) and secondary organic aerosol (SOA) generation potentials (i.e., OFP and SOAFP) were evaluated. The results showed that the total emission of VOCs in the YRD in 2017 was 6.18×106t, where the AVOCs and BVOCs were 3.86×106t and 2.32×106t, respectively. The main components of VOCs in the YRD were alkanes, aromatic hydrocarbons, isoprene, methanol, and terpenes, accounting for 27.6%, 20.2%, 15.4%, 8.7%, and 6.1%, respectively. In terms of seasonal variations, AVOCs emission was relatively stable, while BVOCs emission showed significant seasonal variation in which the majority amount of BVOCs was emitted from May to September. In particular, the emission amount of BVOCs in July and August accounted for 40.3% of the total annual emission, significantly higher than that of the AVOCs in the same period. Alkene was the main VOCs specie in the period of May to September, while alkanes and aromatic hydrocarbons were the main VOCs species in other months. Spatially, high AVOCs emissions were generally found in economically developed regions such as Shanghai, south-central Jiangsu, northern Zhejiang, and central Anhui. In contrast, high BVOCs emissions were usually found in dense forest areas which were mainly distributed in Zhejiang and southern Anhui. The annual percentages of the contributions of AVOCs and BVOCs to the total OFP were 48.6% and 51.4%, respectively, and that to the total SOAFP were 46.3% and 53.7%, respectively. Shanghai and Jiangsu were dominated by AVOCs, while Zhejiang and Anhui were dominated by BVOCs. Although BVOCs emission in total in the YRD was less than AVOCs emission, it could have significant impacts on O3 and SOA in the summer time, especially in Zhejiang and southern Anhui, where the contribution of BVOCs could be dominant. More attention should be given to the emission characteristics and potential impact of the BVOCs in relevant policy-makings toward pollution control of O3 and fine particulates.
2023 Vol. 43 (6): 2694-2702 [Abstract] ( 417 ) [HTML 1KB] [ PDF 1699KB] ( 2151 )
2703 Ozone sensitivity and precursor emission reduction scheme in Baoding City in summer
ZHANG Xin-yu, WANG Xiao-qi, WANG Chuan-da, ZHANG Jun-feng
Based on the datasets of air pollutant concentrations and meteorological conditions of Baoding from 2015 to July 2019, the relationship between O3 characteristics and meteorological factors in summer season was analyzed. The O3 sensitivity and the reduction scheme of precursors (NOx and VOCs) emissions was determined combining WRF-CMAQ simulations and EKMA curve. Results indicated that monthly average concentrations of MDA8O3 in July from 2015 to 2019 ranged from 138 to 179μg/m3. Compared with 2015, the average concentration of MDA8O3 in July 2019 increased by 10.5%. Among the major meteorological factors, the ozone concentration was positively correlated with temperature (R=0.81 on nonattainment days) and negatively correlated with relative humidity (R=-0.70 on nonattainment days). And higher concentration of O3 mainly occurred accompanied with west wind, southwest wind, south wind and southeast wind. Ozone formation was in the strong VOCs-limited regime in the main urban, southern and eastern suburban of Baoding city, however, it was in the NOx and VOCs transition regime in the western and northern suburban. Thus, it was suggested that the reduction of VOCs emissions should be priority considered in VOCs-limited regime regions. As for the western and northern suburban, the reduction ratio of NOx: VOCs should be larger than 1.
2023 Vol. 43 (6): 2703-2713 [Abstract] ( 190 ) [HTML 1KB] [ PDF 3240KB] ( 954 )
2714 Characteristics, meteorological impacts and potential sources of persistent ozone pollution events in Beijing-Tianjin-Hebei Region during 2015~2020
ZHANG Ying, XU Jian-min, WANG Yao, SU Bao-shan, WU Yan-xing, HU Ting-ting, LIU Run
Based on hourly observed ozone concentration and meteorological reanalysis data from 2015 to 2020, this study analyzed the persistent ozone pollution events, their relationship to the meteorological factors and the potential sources in Beijing-Tianjin-Hebei (BTH) region via the generalized additive model, potential source contribution function and concentration weight trajectory methods. The results show that the number of ozone pollution events lasting three or more consecutive days (OPE3) in BTH increased from 24 days in 2015 to 76days in 2020, accounting for 85% of the total ozone pollution days. The monthly variation in OPE3days were highly consistent with the ozone concentration, with a correlation coefficient of 0.97 from May to September. For example, OPE3 in Beijing mainly occurred under a weather pattern characterized by abnormal anticyclonic, high temperature, low relative humidity, anomalous southerlies and downward air flow. During OPE3, the air mass came mainly from the south of Beijing through a short-distance transport (71.2%). The primary potential sources included the southern Hebei Province, northeastern Shanxi Province, northeastern Henan Province, and northern Shandong Province, together contributing about 79.3% to the OPE3in Beijing.
2023 Vol. 43 (6): 2714-2721 [Abstract] ( 228 ) [HTML 1KB] [ PDF 3168KB] ( 1739 )
2722 Characterizing atmospheric NO2 pollution in Nanjing with ground-based MAX-DOAS and TROPOMI satellite observations
YU Qing-yuan, YIN Yan, ZHANG Xin
The vertical column concentrations and vertical profiles of nitrogen dioxide (NO2) were retrieved based on observations from a multi-axis differential absorption spectrometer (MAX-DOAS) in the northern suburb of Nanjing from May 2018 to December 2020. The spatial and temporal characteristics of tropospheric NO2 were analyzed and compared with the latest TROPOMI (Tropospheric Monitoring Instrument) NO2 products. The results of MAX-DOAS show that NO2 concentration in the northern suburb of Nanjing was influenced by air temperature and solar radiation with low values in summer and high values in winter as well as low values in midday and high values in the morning and evening. And the pollutant mainly came from the southeast direction. The correlation coefficient between TROPOMI data and MAX-DOAS observations was larger than 0.7 in spring, autumn and winter, but only 0.54 in summer, due to the influences of cloudiness and low NO2 concentration in this season. In addition, TROPOMI captured major pollution hotspots in Nanjing urban area and the Yangtze River Delta, which was consistent with the high pollution sector indicated by the MAX-DOAS observations. Meanwhile, both the MAX-DOAS and TROPOMI recorded a more than 50% reduction in NO2 concentration during 16~30 days after the Chinese New Year in 2020 due to the COVID-19 close-down as compared with that in 2019 and 2021, indicating that NO2 pollution at the observation sites was mainly resulted from human activities.
2023 Vol. 43 (6): 2722-2733 [Abstract] ( 277 ) [HTML 1KB] [ PDF 1854KB] ( 1400 )
2734 Contributions to O3 and PM2.5 in summer of vegetation types in typical cities in Beijing-Tianjin-Hebei region
CAI Bin, CHENG Hao-miao, QI Hao-yun, LI Ao-zhe, KANG Tian-fang
Based on the BVOCs emission inventory, WRF-CMAQ model was used with scenario analysis to investigate the effects of BVOCs emissions on O3 and PM2.5 in the Beijing-Tianjin-Hebei region in July 2018. The effects of BVOCs emissions from different vegetation types on O3 and SOA concentrations in Beijing, Handan, Chengde, Baoding and other cities were quantitatively analyzed, which was verified with the O3 and SOA formation potential method. As the results showed, the contributions of BVOCs emission to O3 in Beijing, Handan, Chengde and Baoding were 30.19%, 24.77%, 35.56% and 26.73%, respectively, and the contributions to SOA were 2.55%, 3.32%, 4.17% and 3.59%, respectively. Trees and orchards showed the greatest influences on O3 and SOA in Beijing and Chengde, while grassland and crops showed the greatest contributions in Handan and Baoding. Additionally, the results of numerical simulation and of potential generation method showed relatively consistent results.
2023 Vol. 43 (6): 2734-2743 [Abstract] ( 232 ) [HTML 1KB] [ PDF 1076KB] ( 1366 )
2744 Effects of emission reduction measures on the particle size distribution characteristics of atmospheric particulate matter: Based on the observations before and after the 2022 Beijing Winter Olympic Games
ZHAO Gang, ZHANG Ya-bin, ZHAO Ming-sheng, HAN Hui-xia, LI Gang, YANG Xiao-yang, ZHAO Yu-xi, CHU Yang-xi, CHE Fei, GAO Jian, REN Li-hong
To investigate the distribution of particle number concentration (PNC) in Beijing during the 2022 Winter Olympic Games (WOG), particle size distributions ranging from 3 to 660nm were measured using a Scanning Mobility Particle Sizer (SMPS) from December 1, 2021 to March 28, 2022. By comparing the PNC with gaseous pollutants and meteorological parameters, the PNC and particle size distribution characteristics on new particle formation (NPF) days and non-NPF days before and after the WOG were analyzed. The results indicate that PNC decreased with the implementation of emission reduction measures. During the WOG period (February 1to February 20, 2022), the mean PNC, surface area concentration, and volume concentration of particulate matter decreased by approximately 4.0%~33.3%, 17.1%~41.1%, and 11.7%~41.2%, respectively, compared to other periods within the observation period. These reductions demonstrate the effects of local emission reduction measures and coordinated regional pollution control efforts during the WOG. On NPF days, the PNC in the accumulation mode during the Winter Olympics decreased by about 15.3%~25.1%, while ultrafine PNC increased from 12078cm-3in pre-WOG to 20600cm-3 in post-WOG, primarily influenced by favorable nucleation conditions such as high concentrations of O3 and gaseous sulfuric acid, high solar radiation intensity, low NO2 concentrations, and condensation sinks. On non-NPF days, the PNC decreased by 4.4%~5.5% during the emission limitation period, which may be due to the reduction of primary emissions. The PNC showed a bimodal distribution, with the main peak particle sizes in the range of 3~25and 60~150nm on NPF and non-NPF days, respectively. On non-NPF days, PNC in the 10~35 and 50~150nm particle sizes during the WOG decreased by 17.4%~29.0% and 12.0%~24.2%, respectively, which were associated with the reduction of traffic emissions. During the morning and evening traffic peaks (07:00~09:00 and 18:00~22:00) on both NPF and non-NPF days, the PNC decreased, and the decrease in ultrafine PNC on non-NPF days was greater during these periods than during other times, indicating that the reduction in traffic emissions effectively reduced atmospheric PNC.
2023 Vol. 43 (6): 2744-2754 [Abstract] ( 212 ) [HTML 1KB] [ PDF 2779KB] ( 1216 )
2755 Particle size characteristics of source apportionment and chemical composition of atmospheric dustfall in Taiyuan
TIAN Xiao, XIE Yu-qi, XU Bo, WEI Yu-ting, XU Han, ZHANG Zhong-cheng, FENG Yin-chang, SHI Guo-liang
This study collected dustfall samples at 8 monitoring stations in Taiyuan from November 2019 to December 2020 and analyzed their chemical compositions, size distributions, and source characteristics. The key results are shown as follows. First, the particle size of dustfall was significantly affected by the sampling area, larger at the southern stations and smaller at northern stations. The particle size was also generally larger in autumn and winter, linked to the spatial-temporal characteristics of the dustfall sources in Taiyuan. In addition, the chemical components of dustfall with different particle sizes were obviously different in various spatial-temporal conditions, especially for OC, SO42- and inorganic elements such as Ca, Si, Fe, etc. According to the results from the receptor models, urban dust contributed greater to dustfall with different sizes in Taiyuan (33.7%~37.5%). Meanwhile, construction dust (21.8%~31.6%) and steel industry (5.1%~18.1%) contributed significantly to medium and large particle size dustfall. The influence of coal combustion (14.1%~22.6%) to small size dustfall could not be ignored.
2023 Vol. 43 (6): 2755-2762 [Abstract] ( 174 ) [HTML 1KB] [ PDF 2259KB] ( 829 )
2763 Pollution characteristics and risk assessment of atmospheric heavy metal deposition in Beijing
YIN Yu-zhu, FAN Yan-guo, PAN Yu-chun, SUN Zai-jin, MA Hao-sen, GAO Yun-bing
In order to understand the spatial characteristics and the health risk level of heavy metal deposition flux in Beijing during the epidemic, 52 sets of atmospheric dust samples were collected in Beijing from 2020 to 2021. Laboratory instrument was used to measure the content of six heavy metals (Cr, Ni, Cu, Zn, As, Cd) in the samples, then we calculated the precipitation flux. The results showed that the average content of Cd was less than 10mg/kg, the average content of Cr, Ni, Cu, As was 10~100mg /kg, and the average content of Zn was more than 100mg/kg. The contents of Cr, Ni, Cu, Zn, As and Cd exceeded the Beijing soil background value, and the excess rates were 93.9%, 51.0%, 98.0%, 100.0%, 89.8% and 100.0%, respectively. The precipitation flux of heavy metals in Beijing were similar to the weighted average of agriculture and rural areas in China, and significantly higher than foreign areas. The precipitation flux of heavy metals in Beijing urban area were generally lower than suburban areas. The results of ground accumulation index showed that the pollution levels of each element were in the order of Cd > Zn > Cu>Cr>As>Ni, among which Cd and Zn were moderately and moderately polluted, and the other elements were mildly polluted. In 13monitoring sites, the moderate potential ecological hazards ranged from 23.1% to 76.9% in four quarters, among which Cd had moderate hazard and strong ecological hazard. The results of health risk assessment showed that there were non-carcinogenic risks of Cr and As in adult and children.
2023 Vol. 43 (6): 2763-2776 [Abstract] ( 303 ) [HTML 1KB] [ PDF 1125KB] ( 1822 )
2777 Polycyclic aromatic hydrocarbons about the atmosphere in scrap vehicle dismantling base
RAN Xue-ling, LI Lin, QIN Yu-fei, LIANG Yun-yan, XIE Hai-hua, HE Zi-zhen, WANG Jian-bo, LU Yan, ZHAN Lu, XU Zhen-ming
On the basis of the data analyzed from the samples collected in the study, the concentration distribution characteristics and component characteristics of PAHs in each region of the scrap vehicle dismantling base were analyzed. The main sources of the pollutants in the scrap vehicle dismantling base were investigated using positive definite factor matrix model (PMF). The BaP toxic equivalent method (BaPeq), incremental lifetime carcinogenic risk (ILCR) model and comprehensive scoring method were employed to evaluate the impact of PAHs on human health and to identify priority controlling pollutants of PAHs. The results showed that concentration of PM2.5, PM10, and gas phase was respectively 0.638μg/m3, 0.634μg/m3 and 1.6131μg/m3; illustrating that the concentration of PAHs in gas phase was much higher than that in particulate matter. The order of the concentration of PAHs in both gas phase and particular matter according to ring number was 2~3rings> 4rings> 5~6rings; the main sources of the pollutants were identified as synthetic fiber emission and petroleum volatileization; The carcinogenic risk may exist in the scrap car storage area, other areas in the factory, mechanical crushing area, car dismantling area, vehicle dismantling area and manual sorting area; The priority controlling pollutants were identified and their controling order shall be Nap> Chr> Flu> Fla> BaA> BbF> BaP> BkF> IcdP> BghiP.
2023 Vol. 43 (6): 2777-2787 [Abstract] ( 210 ) [HTML 1KB] [ PDF 1037KB] ( 1425 )
2788 Photothermal catalytic degradation of toluene by CuxO/Bi/Bi2WO6/BiOCl
FANG Hong-li, CHEN Jia-yi, ZENG Wen-jing, WU Su-qin, ZHANG Miao-miao, YUAN Shao-tang, RUI Ze-bao
Type II and Z scheme complex heterojunction CuxO/Bi/Bi2WO6/BiOCl with tight interfaces was synthesized. Based on the surface plasmon resonance effect of the component Bi nanoparticles, unique photogenerated charge transfer and separation route, and suitable redox potential for active oxygen species production, CuxO/Bi/Bi2WO6/BiOCl exhibited wide light response range, strong light absorption, and efficient photogenerated charge separation and active oxygen species production properties. Multicomponent complex heterojunction CuxO/Bi/Bi2WO6/BiOCl demonstrated excellent photothermal synergistic catalytic toluene degradation performance. Under 90℃ coupling light (300mW/cm2, λ=200~2500nm) irradiation, 0.0005% of toluene was completely mineralized on CuxO/Bi/Bi2WO6/BiOCl in 0.5h, ranging among the best performance of the reported photothermal catalysts under similar conditions.
2023 Vol. 43 (6): 2788-2797 [Abstract] ( 248 ) [HTML 1KB] [ PDF 1315KB] ( 1226 )
2798 Adsorption of low concentration CO2 with modified red mud
LIANG Wen-jun, YANG Lan, ZHANG Yan, FANG Hong-ping, LIU Jia
Mesoporous modified red mud adsorbent (MRM) was prepared via acid digestion and alkali reprecipitation, red mud (RM) was used as raw material in our experiment. MgO was loaded on the MRM as the support by impregnation method in order to increase the alkaline active site. The structural properties and the composition of samples were characterized and analyzed by BET, XRF, XRD, CO2-TPD. The results showed that the specific surface area of the MRM was about 28 times higher than the RM, the pore structure was rich, and hematite was the dominant mineral phase composition in MRM. It could be seen that the specific surface area and the pore volume decreased with the increase of the Mg loading, which was due to the occupation and the blockage of the pore structure of the MRM support by MgO. The XRD test results of 5% MgO/MRM did not show the peak shape of MgO, maybe because the loading was small or Mg dispersed on the pore channels of the MRM. When the adsorption temperature was 30℃, the CO2 adsorption capacity of the MRM was 1.54mg/g, the adsorption capacity of 5% MgO/MRM was 2.26mg/g, which indicated that the number of alkaline active sites increased significantly after MgO loading, and the chemical adsorption effect enhanced. With the increase of the temperature, the adsorption capacity gradually decreased. The results of the CO2-TPD test showed that both MRM and 5% MgO/MRM were dominated by chemisorption, which formed the carbonate and bicarbonate structures.
2023 Vol. 43 (6): 2798-2805 [Abstract] ( 238 ) [HTML 1KB] [ PDF 700KB] ( 1442 )
2806 Emission characteristics and stable carbon isotope composition of BTEX in coal coking process
MU Ling, FENG Chuan-yang, LI Yang-yong, LI Xiao-fan, LIU Tian, LIU Zi-ye, JIANG Xin
Emission characteristics and stable carbon isotopic (δ13C) composition of BTEX emitted from different production processes in a typical coal coke plant were measured, and the total BTEX emissions during the coke production in China were estimated. The total emission factor (EF) of BTEX from coal coking process was 16655mg/t coke, among which the EF from coke oven flue gas was the highest (7167mg/t), followed by the flue gases from coke pushing (6454and 1825mg/t), sewage treatment (1096mg/t) and chemical byproduct recovery (112.7mg/t). The total emissions of BTEX from the coking in 2020 were 7844 tons in China, and Shanxi (22.27%), Shaanxi (10.39%), Hebei (10.24%) and Inner Mongolia (8.96%) made higher contributions. Benzene was the most abundant compound, accounting for 86.12% of the total BTEX, followed by Toluene (11.45%); and δ13C of BTEX from coal coking ranged from -27.10‰ to -32.58‰. There was no significant difference in the carbon isotope composition of BTEX emissions from different processes during the coal coke production, and the unique B/T (Benzene/ Toluene) ratio and δ13C value of benzene imply that it could be a good marker for distinguishing coking emissions from other sources in the ambient air.
2023 Vol. 43 (6): 2806-2813 [Abstract] ( 201 ) [HTML 1KB] [ PDF 829KB] ( 1245 )
2814 Environmental behavior, investigation and risk assessment technologies of VOCs in contaminated sites
ZHANG Wen-yu, ZHONG Mao-sheng, JIANG Lin, WANG Shi-jie, SONG Bo-yu, LAI Jin-yu, MA Lin, LI Ji-hong, WANG Jia-min
Volatile Organic Compounds (VOCs) are common in contaminated sites, presenting complex environmental behaviors and high risks for investigation and risk assessment. This paper outlines the major environmental processes of VOCs partitioning and transport in soil, followed by a review of VOCs investigation techniques, risk screening methods, vapor intrusion models, and integrated VI risk assessment methods using multi-lines of evidence. Additionally, the main issues in investigating and assessing VOCs contaminated sites in China are compared to international lessons, from which valuable insights can be gained. Finally, recommendations for improving the investigation and risk assessment of VOCs contaminated sites in China are also provided.
2023 Vol. 43 (6): 2814-2822 [Abstract] ( 173 ) [HTML 1KB] [ PDF 739KB] ( 1534 )
2823 Dust emission and control of construction sites and bare land based on remote sensing monitoring
LI Ting-ting, XU Tao, GENG Kai-yu, ZENG Qing-wei, GONG Fu-qian, FAN Shou-bin
Taking Changping District of Beijing as a research object, based on remote sensing monitoring and emission factor method, this paper analyzed the distribution, emission characteristics and control situation of dust sources from construction sites and bare land. The results showed that the total area of construction sites with different scales was not much different, among which small-scale construction sites account for an absolute advantage, and the dustproof rate of large and medium-sized construction sites was higher than that of small-scale construction sites. Compared with construction sites, bare land had a larger total area, more quantity, smaller unit area, and relatively greater difficulty in control. The dustproof rate of bare land was the lowest. Beiqijia Town and Shahe Town account for 40% of the total area of construction sites in the whole district, indicating that urban construction was developing northward from Huitian area. The dustproof rate of Huitian area and its adjacent Shahe Town and Beiqijia Town was higher than that of Baishan Town, Cuicun Town and three mountainous towns in the north. The TSP emissions from construction sites and bare land in Changping District were 48285t and 2756t respectively in 2021. The dust emission from bare land was only 6% of that from construction sites. Compared with the theoretical value without control measures, both construction site dust and bare land dust reduced emissions by 25%, among which Huitian area had better control effect on both construction site dust and bare land dust than other areas. This study combined localized emission model with remote sensing interpretation to estimate dust emission amount, which can solve the problem of underestimation of emission amount by using non-localized emission factors. It provided a way to promote localization of dust measurement for construction site and bare land, improved spatial-temporal accuracy and update efficiency.
2023 Vol. 43 (6): 2823-2832 [Abstract] ( 323 ) [HTML 1KB] [ PDF 3236KB] ( 870 )
2833 Effects of pore structure of hypercrosslinked polymeric resin on adsorption and desorption of carbon disulfide
QU Hong-chang, MA Jia-kai, WANG Jing, JING Tao, LONG Chao
As a chloromethylation reagent, suspension copolymerization of styrene and vinyl benzene was used to create a number of hypercrosslinked polymeric resins (HPRs). By altering the types of pore-forming agents (toluene or liquid paraffin) and the volume of vinyl benzene, a series of ultra-high cross-linked adsorption resins with different pore structures of HPRs were synthesized. The column breakthrough adsorption experiments demonstrate that the adsorption capacity of HPRs for CS2is related to the microporous volume between 0.4 and 1nm (0~2nm), but has no obvious correlation with specific surface area and total microporous volume (0~2nm). The temperature-programmed desorption studies reveal that, when the adsorption resin has a higher proportion of mesopores and macropores, the CS2 desorption becomes easier with a lower peak temperature.
2023 Vol. 43 (6): 2833-2840 [Abstract] ( 196 ) [HTML 1KB] [ PDF 857KB] ( 1084 )
Water Pollution Control
2841 Characteristics and mechanism of bisphenol A degradation by persulfate activated by Fe/TiO2-X under visible light
FU Quan-chao, XU Lu, LIU Pei-hua, JIN Xin, JIN Peng-kang
In this study, TiO2 and FeCl3 was used as raw materials, Fe/TiO2-X catalysts with high visible light catalytic activity were successfully prepared by hydrothermal-calcination method and applied to the catalytic degradation of BPA by persulfate. The results showed that this system has excellent catalytic oxidation ability, the degradation rate of BPA (50mg/L) reached 100% in 40min, and the salinity reached 68.92%. At the same time, the effects of self-doped Ti3+ in the composite and the amount of catalyst and PS concentration on the degradation of organic compounds were studied. This system can realize the efficient cycle of trivalent iron and divalent iron by autogenic photoelectron reduction of Fe3+. Sulfate radical (SO4-•) and hydroxyl radical (•OH) were the main active oxidizing substances in the system, of which the contribution rate of •OH is more than 66.2%. The result also showed that alkaline environment and inorganic anions such as CO32- had negative effect on the performance of the system.
2023 Vol. 43 (6): 2841-2852 [Abstract] ( 185 ) [HTML 1KB] [ PDF 4536KB] ( 3261 )
2853 Steel slag enhanced iron-nitrogen porous carbon activated peroxymonosulfate to degrade tetracycline
CHEN Ai-xia, LEI Chan-juan, TIAN Zheng, WEI Xiao, WANG Ning, YANG Xu-lin
A new magnetic iron-nitrogen porous carbon with steel slag composite (PC-Fe,N/SS) was obtained by combining iron-nitrogen porous carbon (PC-Fe,N) made from wood chips with steel slag (SS) by a mechanical ball milling method to degrade tetracycline (TC) with its activated peroxymonosulfate (PMS). The results showed that the TC degradation rate of PC-Fe,N/SS/PMS system was 87.50% at initial TC concentration of 20mg/L, PMS and catalyst dosage of 0.50g/L, and pH value of 7.0 within 30min. This was mainly because the surface pore structure and internal electronic structure of porous carbon were improved by KHCO3 and N doping, which provided more reaction sites for PMS; the functional advantages of PC-Fe,N and SS were synergized by the ball milling method, while the agglomeration of Fe nanoparticles on the surface of the material were reduced, which promoted the activation of PMS and the degradation of TC. The VSM and XPS characterization results showed that the saturation magnetization intensity of the material was 28.93emu/g, which was favorable for the separation and recovery; Fe0 and Fe2+ played an important role in the degradation of TC. The results of radical quenching experiments and electron paramagnetic resonance (EPR) tests revealed that the main active species in the degradation of TC by the PC-Fe,N/SS/PMS system was the sulfate radical (SO4•-).
2023 Vol. 43 (6): 2853-2863 [Abstract] ( 226 ) [HTML 1KB] [ PDF 2457KB] ( 965 )
2864 Effect of sodium dodecyl sulfate on naphthalene degradation by thermally activated persulfate
ZHANG Hui, ZHANG Cheng-wu, FU Yu-feng, YAO Yu, GUO Chao, QIN Chuan-yu
Surfactant-enhanced soil washing processes typically produce various washing solutions that contain hydrophobic organic compounds and surfactants. How to effectively remove the target pollutants while minimizing surfactants degradation for reuse has become a major concern for the remediation project. Therefore, the effect of sodium dodecyl sulfate(SDS), an anionic surfactant commonly used in soil washing, on degradation of naphthalene by thermally activated persulfate(PS) was studied. The results showed that the degradation of naphthalene was inhibited by the protection of SDS micelles, but the free radicals still preferentially degraded naphthalene in the mixtures of naphthalene and SDS. When the amount of SDS was 5times of the critical micelle concentration (5CMC), the degradation rate constant of naphthalene (knap= 0.0108min-1) was 18times that of the SDS (kSDS= 0.0006min-1). At 10CMC, the morphology of micelle changed from the spherical at 5CMC to the vesicle, which greatly enhanced the protection of naphthalene by the micelle, thus reducing the preferential degradation of naphthalene in the system. In addition, the effect of PS dosage on the preferential degradability of naphthalene was investigated, and the path and mechanism of naphthalene degradation were also analyzed. The response surface methodology was used to establish a prediction model and the reaction conditions were optimized correspondingly, such model can guide the dosage of reagent in the process of treating actual soil washing solutions according to the desired effect.
2023 Vol. 43 (6): 2864-2873 [Abstract] ( 197 ) [HTML 1KB] [ PDF 3313KB] ( 1513 )
2874 Removal of of Ni(II) from water using silicified micron zero-valent iron
MENG Yue, CHEN Xin-fu, ZHANG Xu, ZHENG Ming-xia, YU Min-da, HU Xiang
A novel silicified micron zero-valent iron (Si-mZVIBM) was prepared by mechanochemical method using soluble silicate as the precursor and the Si-mZVIBM was applied to treat the nickel-containing wastewater. The results showed that the silicon modification can significantly enhance the nickel removal efficiency of micron zero-valent iron. Compared with the unmodified micron zero-valent iron, the nickel removal efficiency was increased by 8times. Furthermore, the Si-mZVIBM showed excellent performances in a variety of actual nickel-polluted water bodies. Based on the microstructure, surface electronegativity and elemental composition analyses of the Si-mZVIBM, it was found that the excellent nickel removal performance of Si-mZVIBM was mainly due to the accelerated refinement of micron zero-valent iron particles by mechanical siliconization. The increase of specific surface area and dispersibility of the Si-mZVIBM promoted the mass transfer of nickel from solution to material surface. At the same time, the silicification also could accelerate the electron transport rate at the interface of micron zero-valent iron, which resulted in rapid reduction and precipitate separation of nickel adsorbed on the surface, and eventually realized the efficient removal of nickel.
2023 Vol. 43 (6): 2874-2880 [Abstract] ( 193 ) [HTML 1KB] [ PDF 1518KB] ( 1398 )
2881 Adsorption characteristics and environmental factors of lepidocrocite to ofloxacin
GAN Cui, LI Yu-qiong, ZHANG Tian-lun, TONG Lei
In this paper, the kinetics and thermodynamic process of adsorption of typical fluoroquinolone antibiotic of ofloxacin (OFL) on lepidocrocite and its environmental influencing factors were investigated by chemically synthesized lepidocrocite. The results showed that, the adsorption process of OFL on lepidocrocite was more fitted with the pseudo-second-order kinetic model (R2=0.991) and the Freundlich model (R2=0.996). The equilibrium adsorption capacities (Qe) was 1.99mg/g and the reaction is spontaneous and exothermic. The adsorption of OFL by lepidocrocite is strongly pH dependent, which mainly depends on the charged nature of lepidocrocite and the existence form of OFL ions under different pH conditions; the increase of ionic strength will weaken the electrostatic repulsion between lepidocrocite and OFL, which will lead to an increase of adsorption. The adsorption of OFL on lepidocrocite was promoted by fulvic acid (FA); The two coexisting ions have different effects on the competitive adsorption of OFL. Ca2+ inhibits the adsorption of OFL, while NO3- has no significant effect. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) showed that the adsorption mechanism of OFL adsorption on lepidocrocite was dominated by bidentate chelate coordination or double-bridge coordination with the participation of carboxyl groups.
2023 Vol. 43 (6): 2881-2888 [Abstract] ( 177 ) [HTML 1KB] [ PDF 1722KB] ( 590 )
2899 Degradation of tetracycline under denitrification and methanogenesis system and its performance change
GONG Qing, WANG Zhen, XING Jian-bo, WANG Su-fang, ZHOU Ai-juan, YUE Xiu-ping
To effectively remove tetracycline (TC) from wastewater, the degradation characteristics and system performance changes of TC under anaerobic denitrification simultaneous methanogenesis (SDM) system were investigated using sodium acetate as a co-metabolizing substrate. The degradation rate of TC (1mg/L) in SDM system could reach 82.6% within 5d, and the degradation rate of TOC during TC degradation could reach more than 95%; however, a certain concentration of TC pressure had an inhibitory effect on TC degradation, NO3--N removal and CH4production, which affected the performance of SDM treatment wastewater. In addition, the degradation pathways of TC by microorganisms in the reaction system were mainly hydroxylation, carbon bond breaking and deamination, etc. Based on the intermediate products, it was concluded that the anaerobic functional groups were enriched by high-throughput sequencing, and the bacterial phylum were Proteobacteria, and the dominant genera were Candidatus_Promineofilum and Candidatus_Microthrix. The Archaebacteria phylum were mainly Euryarchaeota and Halobacterota, and the dominant genera were Methanosaeta and Methanothrix. Finally, the effluent biotoxicity was tested and the results showed that the effluent biotoxicity was reduced at the end of the cycle and was close to that of the blank group.
2023 Vol. 43 (6): 2899-2907 [Abstract] ( 231 ) [HTML 1KB] [ PDF 1276KB] ( 1321 )
2908 Effects of modified rice husk-derived biochar on denitrification and N2O emission from water
WANG Chao-xu, LIU Yong-chao, CHANG Zhi-lin, CHEN Qi-bin, WANG Yong, LI Zuo-chen, YAN Ming, WEI Yang
The study focused on exploring the effects of H2O2-and NaBH4-modified rice husk-derived biochars (BC-H2O2 and BC-NaBH4) on denitrification and N2O emission and the potential mechanisms. Based on BC-H2O2 and BC-NaBH4 preparation and their physicochemical property and surface oxygen-containing functional group content determination, the pristine rice husk-derived biochar (BC), BC-H2O2, and BC-NaBH4 were added into the incubation system containing the screened anaerobic denitrifier (DB) at the ratio of 1% (w/V), respectively. The microcosm incubation experiment was carried out to explore the removal efficiency of nitrate nitrogen (about 10mg/L) from simulated wastewater by DB. Results showed that H2O2-modification increased the carboxyl content on the surface of biochar, while NaBH4-modification increased the contents of lactone and phenolic hydroxyl on the surface of biochar. In addition, the Fourier transform infrared spectra analysis showed that C=O content of BC-H2O2 was significantly higher than that of BC. The denitrification rate peaks of DB+BC-H2O2 and DB+BC-NaBH4 appeared 12h earlier and their values were 17.50% and 6.32% higher than that of DB+BC, respectively. Compared with DB+BC, the cumulative N2O emission of DB+BC-NaBH4 increased by 10.43%, but the difference was not significant. However, the cumulative N2O emission of DB+BC-H2O2 increased by 165.54% and the N2O/(N2O+N2) ratio increased by 170.00% significantly, while there was no significant difference in the cumulative N2O+N2 emission between DB+BC-H2O2 and DB+BC (P<0.05). The result indicated that BC-H2O2 inhibited N2O reduction to N2 and promoted N2O emission, which might be related to the decrease of pH and carbon bioavailability and the increase of C=O content induced by BC-H2O2 amendment.
2023 Vol. 43 (6): 2908-2916 [Abstract] ( 269 ) [HTML 1KB] [ PDF 1156KB] ( 1054 )
2917 Microbial resistance and community changes during the adsorption of sulfadiazine through fixed bed
ZENG Xue-Yu, DENG De-Qi, LIU Kang-Kang, HU Mei-Li, CAO Hai-Lei, Lü Jian
The fixed bed was filled with phosphoric acid modified coffee residue biochar (PABC-700) for the dynamic adsorption of sulfadiazine (SDZ) in water. The effects of influent flow rate, adsorbent filling height and initial concentration on the adsorption properties of sulfadiazine were systematically analyzed, and the microbial resistance and community change in the fixed bed under the long-term selective pressure of SDZ were then evaluated. The results showed that the dynamic adsorption behavior of PABC-700fixed bed for SDZ in water conformed to Yoon-Nelson and Adams-Bohart models. The resistance gene abundance changes of sul1 and sul2 according to the results obtained from qPCR showed that the long-term operation of the fixed bed would lead to the proliferation of sulfonamides resistance genes in the effluent. With the increase of SDZ concentration in the system, the abundance of sul1 and sul2 on biochar also showed an increasing trend. The expression of sul1 and sul2 in the group exposed to 1.0mg/L sulfadiazine was 1.97 and 1.53times that of the control group. The microbial community structure on the surface of biochar, as well as the inlet and outlet of the water after the long-term operation were analyzed using Miseq PE300sequencing technology. The results showed that the microbial community diversity on the fixed bed was significantly attenuated compared with the control group, and there was a significant correlation between the purified effluent and the bacterial community structure on the fixed bed biochar. More attention should be paid to the proliferation of conditional pathogenic bacteria Mycobacterium in filtered effluent.
2023 Vol. 43 (6): 2917-2925 [Abstract] ( 179 ) [HTML 1KB] [ PDF 1796KB] ( 1385 )
2926 Isolation and identification of a vanadium reducing bacterium and the mechanism of V(V) bioreduction
ZHOU Rui, ZHOU Ya-qi, WANG Li-li, SHENG Mi-xue, SI You-bin
In this research, a strain of bacteria with vanadium reduction ability was isolated from the vanadium contaminated soil, and the influence of different V(V) concentration, inoculum amount and pH value on V(V) reduction was investigated. Meanwhile, the extracellular and intracellular V(V) reduction by strain and the enzyme activity changes involved in V(V) reduction were characterized to reveal the mechanism of V(V) bioreduction. The results showed that strain NC1-2 was identified as a strain of Enterobacter kobei. When initial V(V) concentration was 160mg/L, the reduction rate of V(V) by the strain was 96.29%. Increase bacterial inoculation accelerated V(V) reduction by the strain, and pH 8.0 was the optimal condition. With decreased the cell membrane permeability, the reduction rate of V(V) increased from 71.2% to 75.0%. There were differences in the reduction of V(V) by different subcellular fractions. It was found that the reduction rates of V(V) by extracellular exudates and cytoplasmic fractions were 41.71% and 80.17%, respectively; No V(V) reduction occurred in the cell membrane fraction. The nitrite reductase (NIR) activity and reduced nicotinamide adenine dinucleotide (NADH) content were increased to different degrees during the reduction of V(V) by the strains. Fourier transform infrared spectroscopy (FTIR) analysis showed the hydroxyl, carbonyl and amide groups on the surface of bacteria were involved in biosorption. Scanning electron microscope (SEM) showed the precipitation around the bacterial body with V(V) reduction. Energy dispersive spectroscopy (EDS) indicated the presence of vanadium in the precipitate. X-ray photoelectron spectroscopy (XPS) analysis showed that strain NC1-2 reduced V(V) to V(IV). Transmission electron microscope (TEM) results indicated that vanadium was precipitated within the bacteria. In summary, the results suggested that strain NC1-2 was able to reduce V(V) and form insoluble V(IV) precipitates intracellularly and extracellularly, and NIR and NADH were involved in the intracellular biotransformation. The research revealed the characteristics and intrinsic mechanism of V(V) reduction by Enterobacter kobei NC1-2, and preliminarily analyzed its intracellular electron transfer. The isolated strain has good application prospects in vanadium pollution remediation.
2023 Vol. 43 (6): 2926-2937 [Abstract] ( 154 ) [HTML 1KB] [ PDF 2352KB] ( 1051 )
2938 Effect of flow velocity on methane and sulfide formation in sewage pipes
LIU Wei, SHI Xuan, XU Dong-wei, JIN Xin, JING Peng-kang
To explore the effects of velocity variation on methane and sulfide generation in urban sewage pipes, the distribution characteristics of the flora and functional genes of methanogens (MA) and sulfate-reducing bacteria (SRB) were investigated by controlling the flow velocity of sewage pipes in the pilot system. The results showed that methane and sulfide were mainly distributed in solid sediment interstitial water and liquid sewage, which were transferred to the liquid phase and the gas phase with the velocity was increased from 0.1m/s to 0.7m/s. Macroeconomic sequencing of the microorganisms in the pipeline showed that the relative abundance of MA microflora increased by 1.24% and the relative abundance of SRB reduced by 0.4%. In the detection of critical enzymes and genes of methane metabolism and sulfur metabolism pathways, it was found that the relative abundance of critical enzymes and genes in the methane metabolism pathway was higher at 0.7m/s and that of critical enzymes and genes in the sulfur metabolism pathway was higher at low flow velocities.
2023 Vol. 43 (6): 2938-2947 [Abstract] ( 170 ) [HTML 1KB] [ PDF 1565KB] ( 1818 )
2948 Research progress on the application of Feammox for nitrogen removal from wastewaters
YANG Li-li, LI Wen-xuan, PENG Yu-zhuo, HU Kai-yao, MU Hao, DONG San-qiang
Iron ammonia oxidation, also known as Fe(III) reduction coupling with anaerobic ammonia oxidation technology has the advantages of low sludge yield, no need for organic carbon, and tolerance to heavy metals. In this review, the potential mechanisms of Feammox, iron reduction pathways and functional microorganisms are described. And key influencing factors including pH, temperature, source of Fe(Ⅲ), organic matter as well as nitrates and nitrites are discussed. From the perspective of coupling Feammox technology with other nitrogen removal processes, the latest development trend of Feammox technology in wastewater treatment applications is reviewed, and the future development is prospected. An overview of the latest developments in the Feammox process provides valuable information for further process optimization and contributes to better nitrogen removal performance in future practical applications.
2023 Vol. 43 (6): 2948-2959 [Abstract] ( 352 ) [HTML 1KB] [ PDF 730KB] ( 5519 )
Solid Waste
2960 Study on the recycling potential of cobalt metal from end-of-life products
LI Jie, LI Fang-qin, HUANG Li, DAI Tao
Cobalt metal plays an increasingly prominent role in battery materials, superalloys, carbides, magnetic materials and other fields. Due to the extremely scarce of reserves and highly concentrated supply, it was currently the focus of major countries around the world. Recycling cobalt metal from end-of-life (EOL) products was generally considered as a key strategy to mitigate environmental pollution and increase resource supply. Based on existing literature, this study reviewed the content, recovery method and recycling rate of cobalt metal in different EOL products, and estimated the demand and spent quantity of cobalt containing products with material flow analysis method and regression analysis method. The recycling potential of cobalt metal in EOL products was calculated accordingly in Chinese mainland from 2022 to 2035. The results show that EOL battery materials are the main source of cobalt metal recycling, especially for passenger vehicles battery materials. China's cobalt metal recycling potential is increasing year by year, and is expected to reach about 24000~38000 tons by 2035. Finally, we put forward some suggestions to provide support for efficient disposal of EOL products, protection of ecological environment, and improvement of resource utilization efficiency.
2023 Vol. 43 (6): 2960-2969 [Abstract] ( 216 ) [HTML 1KB] [ PDF 691KB] ( 1237 )
2970 Effect of the black soldier fly larvae composting efficiency and carbon-nitrogen fixation by in-situ regulation of carbon source composition
YAN Ye-hao, LIN Jia-cong, MAI Li-wen, ZHU Si-xi, LI Qin-fen, WANG Ding-mei
The glucose and rubber sawdust which is considered as high bioavailable and low bioavailable material, respectively, was set as carbon source. And the peanuts meal was used as the nitrogen source in the BSFL composting. 25composting treatments with C/N of 10、15、20、25、30, and the ratio of available carbon component in 0%、25%、50%、75%、100%. Orthogonal partial least squares regression and relevance analysis were used to determine the key indices of composting and C-N fixation effect. BSFL composting effect between different treatments were comprehensively evaluated by principal component analysis. The results indicated that productivity of the larva and larva-cast were 3.96% ~23.06% and 13.38% ~89.99%, respectively. The content of C and N in larva of was 48.12% ~60.31% and 5.79% ~9.85%, respectively, of which 3.24% ~29.58% and 17.21% ~52.69% were recovered from the composting substrate, respectively. The total C and N fixation rates in BSLF composting were 40.69%~93.81% and 38.06% ~72.89%, respectively. The proportion of carbon availability and active nitrogen components exhibits a significant effect on the C-N conversion rate of larva and larva cast (VIP > 1). The ACC1(Available Activity Carbon 1) content and proportion should be more focus on in practical BSFL composting. The best comprehensive effect larva quality and C-N fixation were obtained in the total C/N of 10with the ratio of available to unavailable carbon component in 1: 1. It is insufficient to conduct the BSFL composting only relying on substrate C/N without considering their availability. This study is significant for providing an efficient in-suit method in accurately regulating the bioavailability of the carbon source of the substrate, and finally result in enhancement of larva conversion efficiency and the C-N fixation.
2023 Vol. 43 (6): 2970-2981 [Abstract] ( 192 ) [HTML 1KB] [ PDF 1478KB] ( 1268 )
2982 Spectral characteristics of dissolved organic carbon from biochar pyrolysis in different atmospheres
ZHANG Hui-ying, CHEN Wei-feng, YU Shu-han, XIANG Yu, QIAN Wei, YANG Liu-ming, NI Jin-zhi
In order to explore the spectrum characteristics of biochar-derived dissolved organic carbon (BDOC) from different pyrolysis atmospheres, a series of biochar were prepared from wheat straws, with the combination of different pyrolysis atmospheres (CO2, N2, or air-limitation) and temperatures (300~750℃). BDOC was then extracted and characterized with ultraviolet-visible spectroscopy and fluorescence parallel factor analysis. We found that The DOC released from biochar was enhanced under the CO2 (10.55mg/g) and N2 (10.17mg/g) pyrolysis at 300℃ and also under the air-limited pyrolysis at 450~750℃, resulting in a release of DOC ranging from 0.31~2.88mg/g. The concentration of DOC released from biochar was positively correlated with biochar parameters such as volatile matter content, H/C, and (O+N)/C ratios. In general, air-limitation pyrolysis facilitated the occurrence of BDOC associated with lower molecular weights, or higher aromaticity (SUV254: 7.66~16.86) and humification degree (HIX: 10.77~52.21), or humic acid-like substance; while the contents of proteinoids were higher in the BDOC from CO2 and N2 pyrolysis. In addition, the spectral characteristics of BDOC were more sensitive to temperature variation under the CO2 and N2 atmospheres than under air-limited pyrolysis.
2023 Vol. 43 (6): 2982-2992 [Abstract] ( 235 ) [HTML 1KB] [ PDF 1217KB] ( 1472 )
Soil Pollution Control
2993 Effect of vegetation pattern change on soil mercury accumulation based on carbon and nitrogen stoichiometry
YANG Lu-han, WANG Xun, WANG Ding-yong
To assess impacts of vegetation on the distribution and accumulation of mercury (Hg) in forest soils, we comprehensively determined the contents and stoichiometric relationships among Hg, carbon (C) and nitrogen (N) in forest soils of Hailuogou glacial retreated regions of the Gongga Mountain, Eastern Qinghai-Tibet Plateau. Results demonstrated the enhanced Hg accumulation in all decomposing litter due to the rapid loss of N and C mass during the initial stage of organic soil formation (at ten-year scale). However, the different Hg accumulation process existed between the pioneer broadleaf tree forest and the climax coniferous tree forests in the period of slow degradation processes of organic matter (at decadal to centennial scales). More in detail, the soil mercury concentration in the organic layer of coniferous forest (277.54±117.19ng/g) was significantly greater than that of deciduous forest (204.23±14.38ng/g); we observed the decreasing mercury concentration with the increasing organic soil depth in deciduous forests, while the nearly constant concentration in coniferous forests. These can be explained by the lower N content in coniferous forests than in broadleaf forests (2.11%±0.20% versus 2.64%±0.10%) which leading to the slow the coniferous litter degradation rate. In addition, Hg/C ratio distinctly decreased with the increasing C/N ratio in deciduous organic soils, but without profile trends in coniferous forest soils because of their largely different litter input characteristics and the Hg accumulation patterns.
2023 Vol. 43 (6): 2993-3001 [Abstract] ( 177 ) [HTML 1KB] [ PDF 1007KB] ( 1316 )
3002 Source apportionment and ecological risk assessment of rare earth elements in vertical profiles of paddy soils — Based on Strontium and neodymium isotope tracing combined with MixSIAR model
CAO Jie, YAN Yu, YU Rui-lian, WEN Bo-sen, HU Gong-ren, CUI Jian-yong, YAN Yan, HUANG Hua-bin
To investigate the sources and ecological risks of rare earth elements in vertical profiles of paddy soils, soil samples from three vertical profiles of paddy soils in southeastern Fujian Province and the surrounding potential sources were collected, and the rare earth element contents and strontium-neodymium isotopic compositions in these samples were determined. The source identification was firstly performed based on rare earth element contents and geochemical characteristics of vertical profile soils and potential sources. The source contribution was then quantified by using strontium-neodymium isotopes in combination with the MixSIAR model. Finally, the contribution of potential sources to the integrated potential ecological risks of rare earth elements in the vertical profile soils were evaluated by the combined results of ecological risk assessment and MixSIAR model. The results showed that rare earth elements in the P1 vertical profile soils were mainly originated from the soil parent material, and rare earth elements reached the medium ecological risk level. Rare earth elements in the P2 vertical profile soils were influenced by chemical fertilizers, and the ecological risks of rare earth elements in the shallow soil were greater than those in the deep soil. Rare earth elements in the P3 vertical profile soils were influenced by combination factors, and the ecological risks of rare earth elements were smaller. The ecological risks of rare earth elements in vertical profile soils were influenced by human factors while natural sources cannot be ignored.
2023 Vol. 43 (6): 3002-3012 [Abstract] ( 287 ) [HTML 1KB] [ PDF 1865KB] ( 1185 )
3013 Effects of Copper and Zinc residues in swine manure on soil N2O emissions and related factors
ZHANG Ting, JIANG Jing-jing, FENG Lian-jie, JIANG Jing-yan
To explore the responses of different pH soils to Cu and Zn residues in the swine manure from intensive animal husbandry, three vegetable-planted soils with the acidic (pH 5.81), neutral (pH 7.18) and alkaline (pH 8.00) were used to treat with an addition of zero manure (CK), organic manure (M) and polluted manure (MP), respectively. All treatments were incubated for half year under the alternation of dry and wet conditions to exhaust the available carbon and nitrogen from the manure. After that, urea was added to each treatment to examine effects of residual Cu and Zn on N2O emissions and its related factors. The results show that N2O emissions from different pH soils had different responses to MP addition. MP significantly reduced N2O emissions from acidic and alkaline soils, while significantly increased N2O emissions from neutral soil (P<0.05). There were some differences in N2O-producing substrates and microbial factors significantly related to available Cu and Zn in different soils. Further stepwise regression analysis showed that the main drivers of N2O emissions from acidic soil were NH4+-N conversion amount, available Zn content and 18S rRNA abundance. N2O emissions from alkaline soil were decided by NO3--N production level only, while the main driver of N2O emissions from neutral soil was the available Cu content. Relative to M treatment, residual available Cu in MP was significantly negatively correlated to the nirS abundance (P<0.05), while positively associated with AOB amoA abundance (n=3, r>0.95); the residual Cu had the greatest role in acidic soil compared to other soils. The residual Zn was positively correlated with nosZ(P<0.05), 18S rRNA(P<0.1), AOA amoA (P<0.1), and 16S rRNA abundance (n=3, r>0.95), and had the largest promoting effect in neutral soil. Evidently, the effective Cu and Zn residues in MP have an overall inhibitory effect on N2O emission-related microbial genes in alkaline soil. Therefore, alkaline soil should be given priority to reduce the negative environmental and ecological effects of manure in intensive aquaculture if the manure is required to return to the field.
2023 Vol. 43 (6): 3013-3022 [Abstract] ( 201 ) [HTML 1KB] [ PDF 1203KB] ( 800 )
3023 Effects of slope erosion-deposition on soil microbial nutrient limitation in the typical Mollisol region of Northeast China
MO Shuai-hao, WANG Xue-song, ZHENG Fen-li, QIN Qi-shan, WANG Yi-fei, AN Xiao-bing, WANG Lun, HU Wen-tao, ZHANG Jia-qiong
A typical sloping cropland with a hundred-year cultivation in Keshan County of Heilongjiang Province was selected and soil erosion-deposition ratesestimated by 210Pbex tracer technique were used to classify soil erosion intensity grades [including deposition (DS), light erosion (LE), moderate erosion (ME), intense erosion (IE) and severe erosion(SE)] in this study. Then differences of soil carbon, nitrogen, phosphorus contents, microbial biomass and extracellular enzyme activities among soil erosion intensity grades were investigated and effects of soil erosion-deposition on soil microbial nutrient limitations based on vector model of enzymatic stoichiometry were assessed. The results were as follows: soil erosion-deposition rates ranged from -782.7 to 10914.5t/(km2·a), with an average of 3507.6t/(km2·a); sloping spatial distribution patterns of soil erosion-deposition displayed that the LE and ME were mainly found at the upper slope positions and nearby the deposition sites, the IE and SE were mainly observed at the middle slope positions, and the DS was mainly located at the slope toe. Soil carbon, nitrogen, phosphorus contents and microbial biomass generally decreased with an increase in soil erosion intensity grade. The activities of soil carbon acquiring enzyme (BG+CBH) and nitrogen acquiring enzyme (NAG+LAP) were the highest at the DS sites, while soil phosphorus acquiring enzyme activities (ACP) was the highest at the SE sites. Soil microorganisms were co-limited by relative carbon and phosphorus using the vector model of enzymatic stoichiometry; soil microbial relative carbon limitation indicated by the vector length(VL) decreased linearly with an increase in soil erosion rates and a decrease in soil deposition rates, whereas its relative phosphorus limitation indicated by the vector angle(VA) increased linearly, which indicated that soil microorganisms were relatively prominent restricted by soil phosphorus in the study area. The variations of soil enzyme activities and microbial nutrient limitations at different soil erosion intensity grades were contributed 60.1% by soil nutrient contents and microbial biomass, in which soil organic presented the highest explanation under the conditional effect with 17.4%. Overall, the impacts of soil erosion and deposition on soil quality were caused by corporate influences of soil properties and microbial nutrient limitations.
2023 Vol. 43 (6): 3023-3033 [Abstract] ( 193 ) [HTML 1KB] [ PDF 2957KB] ( 1097 )
3034 Effects of nitrogen inhibitors on cadmium uptake and transport in rice
LI Xiao-xue, WANG Yi, XU Chao, WANG Hua-jing, ZHANG Quan, ZHU Qi-hong, ZHU Han-hua, HUANG Dao-you
To understand the effect of urease inhibitor (NBPT), nitrification inhibitor (DCD), combined with urea as base fertilizer amendment on the concentration of chloride-extractable Cd (CaCl2-Cd) in soil and the Cd concentrations in Fe plaque on rice root surface and in various rice tissues, a field plot experiment was conducted in a typical Cd-contaminated rice paddy. Compared to the control, the amendments of NBPT, DCD, and NBPT plus DCD were significantly reduced the CaCl2-Cd concentration in soil, especially for a reduction of 15% in NBPT plus DCD treatment. Though the amount of Fe plaque was elevated in NBPT plus DCD treatment plots, no significant effect of the amendments on the Cd fixation in Fe plaque was found. Compared to the control, the concentration of Cd in rice grain and the transport coefficients of Cd from root to grain (TFgrain/root), from stem to leaf (TFleaf/stem), and from stem to grain (TFgrain/stem) were decreased by 18.4%, 20.0%, 40.6%, and 38.1% in NBPT plus DCD plots, respectively. The decrease of Cd concentration in rice grain in NBPT plus DCD plots could be explained by the decreased TFgrain/root and TFgrain/stem. The NBPT and DCD separately combined with urea singly applied as base fertilizer is an effective measure to reduce the Cd concentration in rice grain.
2023 Vol. 43 (6): 3034-3041 [Abstract] ( 220 ) [HTML 1KB] [ PDF 608KB] ( 1455 )
3042 Application and progress of microbial electrochemical technology in the remediation of petroleum contaminated soil
LI Rui-xiang, LI Tian, Zhang Xiao-lin, ZHOU Qi-xing
Petroleum extraction and transportation can generate large areas of petroleum contaminated sites. In the context of carbon neutrality, microbial electrochemical technology provides a novel low-carbon remediation strategy for the removal of petroleum organic pollutants from soils. Based on this, the operating principle and classification of microbial electrochemical systems were briefly introduced. The feasibility of applying this technology to the remediation of petroleum contaminated soil was specifically analysed with regard to the advantages of low cost, low carbon, high energy conversion efficiency and high controllability. Subsequently, the factors influencing the remediation performance of microbial electrochemical systems were outlined in detail, as well as the enhancement pathways such as increasing the electron acceptors, improving the mass transfer capacity and enhancing the electron transfer capacity of the systems were summarized. The current emerging problems and limitations of microbial electrochemical remediation technology were summarized, and it is suggested that future development should focus on microorganisms, reactors and practical applications in order to guide the practical application in contaminated soils.
2023 Vol. 43 (6): 3042-3054 [Abstract] ( 281 ) [HTML 1KB] [ PDF 509KB] ( 3242 )
Environmental Ecology
3055 Health assessment of aquatic ecosystem based on microbial integrity index——A case study on lakes in Dongxihu District of Wuhan
ZHANG Di-tao, ZHANG Peng, WANG Si-yang, ZHANG Liang, CHANG Jian-bo
In the assessment of ecosystem health based on Index of Integrity (IBI), fish, benthic organisms, and living algae are often used as indicators. However, the number of samples available for assessment has become lesser with a sharp decrease in the producers and consumers. Here, five lakes in Dongxihu District of Wuhan City were taken as the research area, and the Microbe IBI (M-IBI) evaluation approach was established by using the water microorganism data obtained with the environmental DNA (eDNA) technology. After comparing and scoring the water quality and field habitat conditions, five sampling points in Ganjiajiao Lake were selected as the reference; and six important biological indicators were selected to develop the ecosystem health scoring and evaluation approach. The results show that among all the 19sampling points, 7sites were evaluated being healthy, accounting for 36.84%; 8sites being sub-healthy, accounting for 42.11%; and 4sites being general, accounting for 21.05%. All the sites in Ganjiajiao Lake and Yangsijing Lake were at the health level. The evaluation results can reasonably reflect the health status of different lakes, indicating a wide application potential of the eDNA-based M-IBI method in the health assessment of degraded lake ecosystems.
2023 Vol. 43 (6): 3055-3067 [Abstract] ( 382 ) [HTML 1KB] [ PDF 1626KB] ( 3204 )
3068 Rare earth elements in the upper reaches of Yarlung Zangbo river
LIU Xin-ting, HE Wen-cheng, PENG Hui, XIAO Shang-bin, LI Jia
The Contents and distribution patterns of rare earth elements and characteristic parameters of Ce and Eu in water and sediments of the upper reaches of the Yarlung Zangbo River were studied to explore its geochemical characteristics and influencing factors. The results showed that the average content of dissolved rare earth elements in water was 19.28ng/L, and the average content of rare earth elements in sediments was 190.8mg/kg. The rare earth elements in water are rich in heavy rare earth elements (LaN/YbN<1), while sediments with enrichment of light rare earth elements (LaN/YbN>1). Affected by rock weathering, Ce in water is a negative anomaly, or Ce in sediment is no anomaly and weak negative anomaly. Under the influence of water-rock interaction on the migration and transformation of rare earth elements in the water-sediment system, Eu in water shows a positive anomaly, and Eu in sediment shows a negative anomaly. Due to the difference in weathering process caused by different source rock types, the rare earth elements in the source and river sections show obvious spatial heterogeneity.
2023 Vol. 43 (6): 3068-3076 [Abstract] ( 246 ) [HTML 1KB] [ PDF 768KB] ( 1281 )
3077 Distribution characteristics and influencing factors of antibiotic resistance genes in inland rivers of Northwest China
XING Yue, ZHANG Wen, CHENG Yan, CHENG Gang, HU Hai-yang
The distribution characteristics of antibiotic resistance genes (ARGs) and bacterial community structure in surface water of Y River Basin were analyzed based on metagenomics. The relationship between ARGs and environmental factors and bacterial communities was investigated. The results showed that 21 types of ARGs and 1295 subtypes of ARGs, 6resistance mechanisms were detected in the surface water of Y River basin, among which multidrug was the main type of ARGs, macB was the dominant subtype of ARGs, and antibiotic effluents were the main resistance mechanisms.Bacteria were detected at 160 phylum levels and 4149 genus levels, respectively, among which Proteobacteria is the dominant bacteria phylum, Liminohabitans and others are the dominant bacteria genera. The correlation analysis showed that TOC, DOC and CODMn were significantly correlated with various ARGs subtypes(P<0.05); Some genera, such as Flavobacterium, Polaromonas, and Nocardioides, were significantly associated with multiple ARGs (P<0.05) and involved multiple type and resistance mechanisms of ARGs .This study aims to provide data support for ARGs distribution characteristics of typical inland river environment in northwest arid region.
2023 Vol. 43 (6): 3077-3086 [Abstract] ( 159 ) [HTML 1KB] [ PDF 1873KB] ( 1333 )
3087 Pattern in changes of carbon and nitrogen stable isotopes of phytoplankton in Yilong Lake under the influence of human activities
WANG Xu, GUO Wen, WANG Ming-guo, LI Ping, WEN Wen-wen, CHEN Li, ZHENG Xin, HUANG Lin-pei, CHEN Guang-jie
From September 2020 to June 2022, a spatial investigation and seasonal analysis of water quality and carbon and nitrogen isotope signals of phytoplankton were carried out across 20 sites of Yilong Lake over 8seasons. The results showed that the distribution of δ13C signal of phytoplankton ranged from -28.98‰ to -22.32‰, showing lower values in wet year (-26.89‰±1.34‰) than in dry year (-25.30‰±0.97‰), and higher values in September than in other months. Meanwhile, the spatial distribution of δ13C signal showed higher values in western lake basin than those in central and eastern lake basins. The δ15N signal of phytoplankton varied from -0.28‰ to 10.25‰, and was significantly higher in wet year (6.28‰±1.07‰) than in dry year (2.78‰±1.55‰). Meanwhile, the values of phytoplankton δ15N were lower in fertilization season (June and December) compared to other seasons, and also higher in rainy season (September) and early dry season (December) than those in central and eastern lake basins. With increasing water volume in Yilong Lake, there was an increase in inorganic carbon input and a decrease in nutrient levels, resulting in a significant decline in phytoplankton δ13C signal. This may reflect the rapid response of phytoplankton δ13C signal linked to human activities such as water diversion and replenishment measures. Meanwhile, the lower δ15N values of phytoplankton are closely related to lake-water NH4+-N concentration, reflecting the role of nitrogen pollution from agricultural non-point sources (mainly ammonia fertilizer) in affecting phytoplankton absorption. However, the δ15N value of phytoplankton increased significantly with expanding water volume along with a replacement of chemical fertilizers by organic fertilizers during agricultural fertilization, a measure taken for mitigating lake eutrophication. The results of MixSIAR model showed that nutrient loading derived from agricultural non-point sources decreased from 88.4% in the dry year to 79.0% in the wet year, with the contribution of point source pollution increasing from 11.6% to 21.0%. Specifically, the relative contribution of chemical fertilizers decreased from 41.2% to 14.0%, the proportion of organic fertilizers increased from 47.2% to 65.0%. Therefore, pollution control measures, such as water diversion, hydrological replenishment and use of organic fertilizers, have largely reduced the lake-water nutrient concentrations, and this is also evidenced in an increase of the δ13C signal of phytoplankton due to an increased basin input of both the δ13C-depleted carbon and δ15N-enriched nitrogen. In all, our study highlights that lake management and restoration measures can significantly affect the isotopic signal and cycling porcesses of nutrients in the primary producers of lakes.
2023 Vol. 43 (6): 3087-3099 [Abstract] ( 285 ) [HTML 1KB] [ PDF 2776KB] ( 1398 )
3100 An analysis of nitrate sources in Nansi Lake based on nitrogen and oxygen isotopes
LING Jun-hong, ZHANG Yi-zhang, CAO Ying-jie, LI Xu, ZHAO Guang-lei
The Nansi Lake of the eastern route of the South-to-North Water Diversion Project was selected as the research object. The water chemistry and distribution characteristics of different forms of nitrogen in the study area were elucidated by using δ15N-NO3- and δ18O-NO3- isotope tracing techniques and water chemistry analysis, revealing the transformation process of nitrogen and analyzing the source of nitrate. Meanwhile, according to the MixSIAR model, the contribution rates of different nitrate sources in were also identified quantitatively. There was no obvious thermocline in Nansi Lake and the water here was alkaline, the SO42--Na+ type was main hydrochemical type. Nitrate nitrogen was the main form of nitrogen in the subordinate lake. The concentration gradually decreased with the self-purification of water and the adsorption of sediment. The pollution characteristics of the rivers were consistent with that of the lake. Nitrification occurred in the process of nitrate formation, and the nitrate in the lake mainly came from domestic sewage > soil organic nitrogen > synthetic fertilizer > atmospheric deposition. Based on the MixSIAR model, the contribution ratios were 51.3%, 23.7%, 16.4% and 8.5%, respectively.
2023 Vol. 43 (6): 3100-3106 [Abstract] ( 203 ) [HTML 1KB] [ PDF 1112KB] ( 1346 )
3107 Abundance of aerobic ammonia-oxidizing and nirS type denitrifying microorganisms in sediments of Lancang River
WU Zi-xian, CHEN Hao-dong, LI Zhu, CHEN Zhuo, LIAO Ming-jun
In order to explore the impact of cascade reservoir on nitrogen cycling microorganisms in the Lancang River , the abundance of ammonia oxidizing bacteria (AOB), ammonia oxidizing archaea (AOA) and nirS type denitrifying microorganisms in the river sediments were studied. Sediment samples were collected from 19 sites from Yanjing to Ganlanba in Yunnan Province. The abundance of AOB-amoA, AOA-amoA and nirS genes were quantified through qPCR. The physical and chemical factors of sediments, pore water, and water bodies were determined at the mean time. The results showed that AOB-amoA gene abundance ranged from 0.82x107 to 4.25x107 copies/g, AOA-amoA gene abundance ranged from 0.83x107 to 6.87x107 copies/g, and the nirS gene abundance ranged from 0.72x107 to 7.32x107 copies/g; the ratio of AOA/AOB is between 0.35 and 2.17, and AOA is not superior to AOB in the sediment. The abundance of AOA-amoA, AOB-amoA and nirS showed no significant difference in the river, reservoir and tributaries sites, indicating that the dam construction has no significant impact on the spatial distribution of nitrogen cycling microorganism abundances. Ammonia, total phosphorus and total nitrogen concentration in pore water are the main environmental factors affecting AOA abundance. AOB abundance is mainly affected by water temperature, total phosphorus, total nitrogen and total organic carbon content in sediments. The abundance of nirS type denitrifying microorganisms is mainly affected by total nitrogen concentration in pore water, and organic carbon content in sediment.
2023 Vol. 43 (6): 3107-3117 [Abstract] ( 213 ) [HTML 1KB] [ PDF 673KB] ( 1112 )
3118 Changes in optical properties of algae-derived chromophoric dissolved organic matter and photogeneration of carbon monoxide: a case study of Skeletonema costatum
HOU Shu-ran, JI Xuan, ZHANG Jing
The optical properties of chromophoric dissolved organic matter (CDOM) during the growth of Skeletonema costatum, the degradation of its algae-derived CDOM and the generation of carbon monoxide (CO) under different wavelengths of irradiation were studied. The results showed that during the growth of Skeletonema costatum, the CDOM absorption coefficients (a(350)) first decreased and then increased. Three fluorescent components were identified during the culture, including C1(humic-like substance, Ex/Em =325nm/395nm), C2(humic-like substance, Ex/Em =265nm/445nm) and C3(protein-like substance, Ex/Em =275nm/345nm). With the increase of irradiation wavelength, the loss rates of a(350) and the fluorescence intensities of fluorescent components in different growth phases showed an increasing trend. After 9hours of irradiation at 280~800nm, 315~800nm and 400~800nm wavelengths, the a(350) was averagely reduced by 69.07% ±8.23%, 51.85% ±12.54%, 31.12% ±3.40%, respectively. In addition, the production of CO from the photodegradationof algae-derived CDOM increased with the increase of the irradiation wavelength, and the contribution of ultraviolet light to CO production was more than 70%.
2023 Vol. 43 (6): 3118-3128 [Abstract] ( 232 ) [HTML 1KB] [ PDF 2003KB] ( 1698 )
3129 Structure and assembly processes of bacterial communities in Poyang Lake basin
SHE Yuan-yang, WANG Peng, DING Ming-jun, NIE Ming-hua, HUANG Gao-xiang, ZHANG Hua, HUANG Yi-ping, CAO Ying-jie
To investigate the structure and assembly processes of bacterial communities across different spatial-temporal scales, a total of eight surface water samples were collected in Poyang Lake basin (from seven hydrological stations) during the dry season (October to January of the following year) and wet season (April to August), and high-throughput sequencing technology was utilized to examine the bacterial community's structure, assembly processes, and co-occurrence networks. The results demonstrated that the Shannon index was significantly higher (5.12) during the wet season compared to the dry season (4.45), while the Chao1index did not differ significantly between the seasons. Moreover, significant differences in a diversity were observed within the same season, while no significant differences were detected in the a and b diversity of bacterial communities in space. The dominant phyla in the Poyang Lake basin were Pseudomonadota (34.72%), Actinobacteria (32.35%), Cyanobacteria (13.21%), and Bacteroidetes (10.81%). The relative abundance of Pseudomonadota and Actinobacteriota decreased significantly, while Cyanobacteria and Bacteroidota significantly increased during the wet season compared to the dry season. Water temperature (WT) and mean stream network length (MDSL) were identified as the primary environmental factors influencing the structure of the bacterial community at the phyla-level. The co-occurrence networks of bacterial communities in water bodies interacted with each other in collaborative and competitive relationships, which were stronger, more complex, and stable during the wet season than in the dry season. Additionally, the complexity and stability of the co-network were significantly influenced by both WT and dissolved oxygen (DO). The assembly of bacterial communities was predominantly dominated by deterministic processes, with a stronger contribution from these processes during the dry season than in the wet season. Finally, some differences in co-network patterns and assembly processes were observed across different time scales.
2023 Vol. 43 (6): 3129-3140 [Abstract] ( 257 ) [HTML 1KB] [ PDF 4380KB] ( 1525 )
3141 Time-lag responses of turbidity to wind values in Meiliang Bay, Taihu Lake
QU Shan, WANG Jian-jian, YUAN Yuan
The wind values from the field high-frequency simultaneous observations were used to quantitatively characterize the wind direction and wind speed variations, and the generalized summation model (GAM) was used to evaluate the hysteresis effects of individual wind speeds and integrated wind values on surface and bottom turbidity of the Taihu Lake. The results show that: (1) the turbidity in the area of Meiliang Bay in the Taihu Lake was low under light wind conditions (wind speed < 4m/s or wind value < 3), and increased continuously with wind speed. With an increase in wind value, the turbidity showed an increasing trend in the early stage and a flat trend in the later stage; (2) the short-term change in wind direction had a small effect on the turbidity, while the long-term accumulation of one-way wind had a large effect; (3) the lag time of surface turbidity was 5h 45min to wind speed alone, and 1h to wind value, and the lag time of bottom turbidity to wind speed and wind value was 7h and 2h, respectively. Obviously, there was a specific time-lagged responses of turbidity to both wind speed and wind direction, becoming obvious with water depth. Due to the influence of other factors (e.g., topography, etc.), the lake flow had a certain vertical shear, and the influence of wind direction on turbidity variation gradually became weak. Obviously, the dual effects of wind direction and the hysteresis effect determine the accuracy of the eutrophication model, and the studies on wind speed's effects on shallow lakes' ecosystems need to be further enhanced with no ignorance of the effects of wind direction.
2023 Vol. 43 (6): 3141-3149 [Abstract] ( 208 ) [HTML 1KB] [ PDF 1306KB] ( 1172 )
3150 Field test and evaluation of methane oxidation capacity of loess cover in municipal solid waste landfill
ZHAN Liang-tong, WANG Yong, LIU Kai, LAN Ji-wu, FENG Song, WANG Jun-ming, LIN Yi-fan
50 sets of surface methane flux tests were conducted to test and analyze the methane oxidation capacity of the soil cover at different landfilling ages by using static chamber, laser methane detector and other equipment. In addition, a modified calculating method was proposed to directly evaluate the methane oxidation rate and methane oxidation fraction of the soil cover. The field test and analysis results indicated that the surface methane flux at 80% of the test sites were lower than the CFI (Carbon Farming Initiative) standard of 60g/(m2∙d); there were emission hotspots with methane flux exceeding CFI limit within 20m near the gas guide shaft. The surface methane flux of the landfill decreased from 1.13g/(m2∙d) to 0.53g/(m2∙d) during the landfilling ages from 3 to 7 years, and remained basically stable during the period of 7 to 10 years. There was a positive correlation between methane oxidation rate and methane flux at the bottom of the cover. The maximum methane oxidation rate measured in the soil cover was 63.30g/(m2∙d), and the corresponding methane flux at the bottom was 75.95g/(m2∙d). The average methane oxidation fraction of the upper loess cover at each landfilling age was over 90%.
2023 Vol. 43 (6): 3150-3157 [Abstract] ( 202 ) [HTML 1KB] [ PDF 2003KB] ( 1033 )
3158 Effects and mechanisms of polyphenols on heavy metal resistance of eukaryotic microalgae
ZHANG Ting-ting, ZHOU Jing, LI Cheng
The biomass of the eukaryotic microalgae Scenedesmus obliquus under Pb2+ stress with pyrogallic acid (PA) and its mechanism were investigated. The results showed that the inhibition rate of 10.0mg/L Pb2+ alone on S. obliquus was 73.1% on the 4th day, but when Pb2+experiment groups were added with different concentrations of PA (1.0, 5.0, 10.0, 15.0mg/L) at the same time, and the inhibition rates of 1.0~10.0mg/L PA groups were significantly lower than that of Pb2+ alone groups (P<0.05). The mechanism studied indicated that Pb2+ could seriously damage the structure of S. obliquus and increase the oxidative stress of the cells, and induce the significant increase of antioxidant enzymes such as superoxide dismutase (SOD), glutathione reductase (GR), glutathione peroxidase (GSH-Px) and glutathione S-transferase (GST) in the early stage. After adding PA groups, the activities of four antioxidant enzymes in all groups except the highest concentration group (15mg/L PA) were kept at a higher level during the test time, especially in the 5.0~10.0mg/L PA groups, the photosynthetic efficiency and the absorption rate of Pb2+ were significantly higher than that in the Pb2+ alone stress group (P<0.05) and the morphology and structure of the cells were less damaged than that of lead alone stress group. It is speculated that the mechanism of counteracting or protecting S. obliquus from Pb2+attack at a certain concentration of PA may be related to the chelation of heavy metals by PA, which reduces the toxicity of Pb2+ and improves the photosynthetic efficiency of S. obliquus; on the other hand, PA may promote the Pb2+absorption capacity of S. obliquus by enhancing its antioxidant capacity. It is known that PA has strong inhibitory effect on cyanobacteria, therefore, it can become an important potential material for biological removal of heavy metal pollutants and complex heavy metal pollution in eutrophic water.
2023 Vol. 43 (6): 3158-3165 [Abstract] ( 186 ) [HTML 1KB] [ PDF 636KB] ( 993 )
3166 Simultaneous removal of Microcystis aeruginosa and DOC by PFS coagulation combined with Ca3(PO4)2 crystallization
LIAO Min-fei, NIE Xiao-bao, WAN Jun-li, SUN Ju-long, OU Yang-shuai, LONG Yuan-nan, LIU Wan-qi
Simultaneous removal of Microcystis aeruginosa (MA) and dissolved organic carbon (DOC) is desired for drinking water treatment plants (DWTPs) during cyanobacteria blooming. Ca3(PO4)2 crystallization pretreatment was utilized to enhance the coagulation efficiency of polymeric ferric sulfate (PFS), to realize well simultaneous removal performance for MA and DOC. The removal efficiency and mechanism of MA and DOC with Ca3(PO4)2 crystallization combined with PFS coagulation were studied. In addition, the adaptability to various cell densities and controlling of residual phosphorus were investigated. The results showed that at cell density of 2.0×106cells/mL and PFS dosage of 20mg/L, cells and DOC removal efficiencies of PFS were increased by Ca3(PO4)2 crystallization from 72.5% and 33.5% to 91.5% and 85%, respectively. The responsible mechanisms for cells removal were co-flocculation and aggravating effects of homogeneous crystalline products of Ca3(PO4)2; while the improvement of DOC removal rate was credited to the co-crystallization and Ca3(PO4)2 adsorption. The combination of Ca3(PO4)2 crystallization and PFS coagulation exhibited a good adaptability to the change of cell density, and the residual phosphorus concentration was anticipated to lower than 20μg/L. The results suggest that Ca3(PO4)2 crystallization combined with PFS coagulation should be a preferred alternative for DWTPs to removal cyanobacteria.
2023 Vol. 43 (6): 3166-3172 [Abstract] ( 187 ) [HTML 1KB] [ PDF 571KB] ( 804 )
3173 A review on application of stable isotope probing combined with metagenomics in studying the biotransformation and degradation of environmental pollutants
ZHANG Huan-jun, ZHOU Jing-ya, LI Yi
The application of stable isotope probing (SIP) combined with metagenomics in the research of environmental pollutants biotransformation and degradation has gradually become a trend. This combined technology provides a culture-independent method to identify functional microbial community with specific metabolic activities and to reveal key metabolic pathways in complex environment, so it has significant advantages in studying in situ biotransformation and degradation of environmental pollutants. This review introduces the application of this combined technology in studying the biotransformation and degradation of hydrocarbons and their derivatives, pesticides, heavy metals and emerging contaminants in different environments, including identification of functional microbial community and mechanism of pollutants biotransformation and degradation. Finally, future prospect is presented based on the current application status of this combined technology. The combined technology associated with multiple approaches to in situ characterization will provide more accurate and comprehensive information for studying the mechanism of biotransformation and degradation of pollutants driven by microorganisms.
2023 Vol. 43 (6): 3173-3182 [Abstract] ( 427 ) [HTML 1KB] [ PDF 438KB] ( 1997 )
3183 Estimation of anthropogenic heat in China using points-of-interest and multisource remote sensing data
QIAN Jing, MAO Li-wei, YANG Xu-chao, CHEN Qian, LI Fei-xiang, WU Xin-tong, CHEN Bo-ru
Statistics on energy consumption, transportation, population and GDP had been used to estimate anthropogenic heat emissions from industries, transportation, buildings, and human metabolism at the prefecture level for mainland China in 2019. Using the top-down energy inventory method and Cubist machine learning algorithm, anthropogenic heat flux (AHF) models were built by integrating points-of-interest (POI) datafrom a variety of categories and multisource remote sensing data. A gridded anthropogenic heat flux (AHF) benchmark dataset at 1km spatial resolution had generated for China in 2019. The relationships between various geographic predictors and AHF from different heat sources were further analyzed. Results showed that high-value areas of AHF were generally distributed to metropolitan areas and cities with relatively developed industries. The values of AHF in urban centers in mainland China ranged between 80 and 200W/m2. The highest values were reported for some heavy industrial areas up to 519.2W/m2. Cubist models can explore the nonlinear relationships between individual predictors and AHF from different heat sources and give the relative importance of the predictors. POI-related variables are the most important predictors and can further refine the estimation of AHF. Compared with previous studies, the spatial distribution of AHF from different heating components was effectively distinguished, highlighting the potential of POI data in improving the precision of AHF mapping. The new gridded AHF dataset in 2019 for mainland China can serve as important input for urban climate and urban environment numerical models.
2023 Vol. 43 (6): 3183-3193 [Abstract] ( 262 ) [HTML 1KB] [ PDF 4749KB] ( 1525 )
Environmental Toxicology and Health
3194 Dose-dependent joint resistance effects of antibacterial agents on Escherichia coli
TONG Dan-qing, SUN Hao-yu, ZHANG Yu-lian, WANG Jia-jun, TANG Liang, WU Ming-hong
Three kinds of common antibacterial agents, i.e., sulfonamide potentiators (SAPs), silver nanoparticles (AgNPs), and sulfonamides (SAs), were selected to investigate joint resistance effects of SAPs-AgNPs and SAPs-AgNPs-SAs on Escherichia coli (E. coli). In addition, mutation unit (MU) method and plasmid conjugative transfer unit (CTU) method were used to judge the joint resistance actions of these antibacterial mixtures at different concentrations. The results show that 3 groups of SAPs-AgNPs and 9 groups of SAPs-AgNPs-SAs had the dose-dependent joint resistance effects: the joint actions of antibacterial mixtures on promoting the mutation frequency of E. coli were mainly antagonism, and their joint actions on promoting the plasmid conjugative transfer frequency of E. coli were changed from antagonism to synergism with an increase in concentration. These effects were speculated to relate to action mechanisms of the test antibacterial agents. Compared with the single antibacterial agent, SAPs-AgNPs and SAPs-AgNPs-SAs may reduce the resistance risk at low concentrations, and thus lower the emergence risk of antibiotic resistance genes (ARGs) but increase the dissemination risk of ARGs at high concentrations.
2023 Vol. 43 (6): 3194-3202 [Abstract] ( 212 ) [HTML 1KB] [ PDF 1405KB] ( 1568 )
3203 The impact of pesticide use on elders’ medical expenditure through water pollution
ZHANG Hong-liang, ZHAO Lin-xuan, MA Shu-qi, WU Jian, XU Shang
With a panel dataset of 23 provinces from 2002 to 2018, a two-way fixed effects estimator was used to evaluate the impacts of pesticide use on local elders’ medical expenditure as well as on that of elders located in downstream provinces. According to the results, a 1% increase in local per capita pesticide usage led to an increase of approximately 15.26 yuan in per capita medical expenditure for the local elders, while the effect of local pesticide use for elders located in downstream provinces was statistically insignificant. Heterogeneous effects were observed based on drinking water sources. In particular, a 1% increase in local per capita pesticide use led to an increase of approximately 179.50 yuan on medical expenditure for elders who relied on non-tap water sources. These results suggested that local governments should continue to implement agricultural and environmental policies that reduce local pesticide usage, address pesticide pollution within province, and increase tap water accessibility for elders in rural areas.
2023 Vol. 43 (6): 3203-3210 [Abstract] ( 225 ) [HTML 1KB] [ PDF 413KB] ( 1234 )
3211 Assessment of the health benefits of declining PM2.5 levels in the Yangtze River Delta
WEI Tong, LI Zheng-lei, CHEN Yu, ZHAO Xiu-ge, WANG Dan-lu, HOU Ya-xuan, LIU Fen
The aim of this study was to evaluate the health and economic benefits of PM2.5 emission reduction for residents in the Yangtze River Delta (YRD) region. Based on the time-weighted PM2.5 exposure levels, the decreasing trend in PM2.5 exposure of residents in the YRD region from 2011 to 2019, and its health and economic synergies, were analyzed using an integrated exposure-response model and the willingness-to-pay method. The results showed that, from 2011 to 2019, the PM2.5 exposure level in the YRD region decreased by 17.03% from 45.06μg/m3 to 37.39μg/m3. Meanwhile, the number of premature deaths attributable to PM2.5 exposure decreased by 24.65% from 139, 962 (95% confidence interval [CI]: 87306~192619) to 105461 (95% CI: 66306~14416). According to the interannual variation-based sensitivity analysis, the number of premature deaths attributed to PM2.5 exposure showed a downward trend year by year after the implementation of relevant policies in 2012, with cumulative benefits of 4.055 billion dollars. These data indicate the effectiveness of various PM2.5 emission reduction actions in China. Since 2018, the annual economic benefits of PM2.5 emission reduction have decreased. Therefore, while reducing carbon emissions, it is necessary to continue to strengthen the control of pollution reduction to reduce attributable deaths and economic loss.
2023 Vol. 43 (6): 3211-3219 [Abstract] ( 254 ) [HTML 1KB] [ PDF 1594KB] ( 1194 )
Carbon Emission Control
3220 Study of the synergy of high-quality development and pollution abatement and carbon reduction promoted by energy optimal allocation
XU Guang-qing, ZHANG Wen-dan, CHEN Xiao-yu
To study the impact of the market-oriented allocation of energy on TFP, which is the core indicator of high-quality development (HQD), and its effect of pollution abatement and carbon reduction (PACR) to explore the possibility of the synergy of HQD and PACR, a stochastic frontier production function was utilized to estimate the change and decomposition of China's industrial TFP from 2010 to 2020, and the impact on the change of TFP and its energy saving potential based on the optimal allocation in a fully competitive market were estimated. Based on the estimation, the potential and effect of PACR were calculated. The study found that: China's industrial TFP growth was sluggish, but the market-oriented allocation of energy could promote TFP growth; Market-oriented allocation of energy could bring significant potential and effect of PACR. The annual reduction was about 15%~20% of the actual emissions. By continuously promoting energy marketization, with a sound institutional system and a reasonable energy price system, synergy of HQD and PACR could be achieved.
2023 Vol. 43 (6): 3220-3230 [Abstract] ( 229 ) [HTML 1KB] [ PDF 843KB] ( 1892 )
3231 Low-carbon transition pathways for China's transportation sector under the background of carbon neutrality
JIA Lu-yu, WANG Ke
This paper developed a Carbon Emission Reduction Model of China's Transportation (CERM-CT) based on the LEAP model framework, which included four categories and 228 emission reduction technologies and measures. The paper set three scenarios-business-as-usual, carbon emission reduction, and deep carbon emission reduction-to analyze the driving forces and service needs in the transportation sector's low-carbon transition. It analyzed the cost-effectiveness of technological measures and proposed a low-carbon transition pathway for China's transportation sector. It was more cost-effective to reduce vehicle energy consumption and develop new energy vehicles, while adjusting transportation structure had great potential for carbon emission reduction. Under the carbon emission reduction scenario, the long-term carbon emissions of transportation would drop to 440million tons in 2050, 69.7% of that under the business-as-usual scenario. The reduction was equivalent to 330million tons compared to the baseline year, and was expected to lead to economy-wide carbon neutrality between 2060~2070. Under the deep carbon emission reduction scenario, transportation emissions would fall to 190million tons in 2050, which translated to 86.9% and 56.9% reduction compared with the business-as-usual and carbon emission reduction scenarios, respectively. In physical terms, the reduction was 580million tons and 250million tons, respectively, compared with the baseline year and carbon emission reduction scenario, expected to lead to economy-wide carbon neutrality by 2060. Improving fuel economy, promoting faster development of new energy vehicles, controlling motor vehicle holdings, and adjusting the transportation structure were essential ways to achieve low-carbon transition in transportation sector, which could contribute to 25.0%, 16.7%, 8.3%, and 50.0% of emission reduction, respectively. The fixed investment demand for the deep carbon emission reduction scenario between 2021~2030 and 2031~2050 were 4.2 trillion RMB and 6.3trillion RMB, respectively, with an average annual investment of 0.4trillion RMB. The investment was mainly used for the building of new infrastructure, renovation of terminal energy equipment and development of low-carbon technologies, among which new infrastructure accounted for over 80% of the total investment in the two time periods. To achieve low-carbon transition, China's transportation sector needs to continuously optimize the transport structure, support the development of new energy vehicles, develop low-carbon technologies, and increase investment in low-carbon infrastructure and technologies.
2023 Vol. 43 (6): 3231-3243 [Abstract] ( 316 ) [HTML 1KB] [ PDF 688KB] ( 2565 )
3244 Spatio-temporal evolution of urban carbon emission intensity and spatiotemporal heterogeneity of influencing factors in China
LI Yun-yan, ZHANG Shuo
Investigating the Spatiotemporal Evolution and Pathway Migration of Urban Carbon Intensity in China from 2005 to 2020 using Map Visualization, Kernel Density Estimation, and Standard Deviation Ellipses. Empirical Examination of Spatiotemporal Heterogeneity of Factors Affecting Urban Carbon Intensity using a Geographically and Temporally Weighted Regression (GTWR) Model. The study finds that: (1) Carbon emission intensity in Chinese cities has decreased over the years but remains significantly higher than that of developed countries during the same period, with considerable room for emission reduction. Spatially, there is a "north-south" disparity in carbon emission intensity, which has become more prominent in the later period of the study. (2) The differences in carbon emission intensity of cities within each region gradually converged, and the distribution became more balanced. The multi-level differentiation of carbon emission intensity in the eastern region was remarkable, and there were still high carbon agglomerations in the west. The region with high carbon emission intensity gradually shifted to the northwest, and the northwest became the main contributor to China's carbon emissions. (3) In general, high-carbon energy consumption has a positive effect in promoting carbon intensity, while industrial upgrading, economic development, population agglomeration, technological research and development, and foreign investment intensity have mainly negative inhibitory effects. However, at the local level, the effects of these factors exhibit significant spatiotemporal heterogeneity. The direction and strength of the fluctuations of various influencing factors vary across different regions and periods.
2023 Vol. 43 (6): 3244-3254 [Abstract] ( 210 ) [HTML 1KB] [ PDF 1187KB] ( 4998 )
3255 The impact of regional innovation policy on carbon emissions-Quasi-natural experiment based on national independent innovation demonstration zone
ZHENG Zhuo-ji, HAN Xian-feng, YIN Yu-ping
Based on the panel data of 278 prefecture-level cities in China from 2006 to 2020, this paper used the progressive difference-in-differences (DID) model to evaluate the impact and mechanism of the policy implementation of national independent innovation demonstration zones on the quantity and quality of regional carbon emissions. The heterogeneity of treatment effect was also discussed. The results showed that the national independent innovation demonstration zone had effectively driven the quantity reduction and quality improvement of carbon emissions (average values are -0.078 and 0.108). The national independent innovation demonstration zone can ultimately achieve effective carbon reduction by improving energy efficiency, driving green technology innovation, and promoting the rationalization of industrial structure. The national independent innovation demonstration zone had different policy effects in different regions at different stages of economic development. It had a more effective inhibitory effect on carbon emissions in the eastern and slower economic growth regions, and a more obvious effect on carbon productivity in the central and western regions and faster economic growth regions.
2023 Vol. 43 (6): 3255-3264 [Abstract] ( 349 ) [HTML 1KB] [ PDF 575KB] ( 1697 )
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