Acta Academiae Medicinae Sinicae

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CHINA ENVIRONMENTAL SCIENCECE

CHINA ENVIRONMENTAL SCIENCECE

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	2024 Vol.44 Issue.11,Published 2024-11-20

	Air Pollution Control Water Pollution Control Solid Waste Soil Pollution Control Environmental Ecology Carbon Emission Control Emerging Contaminants and Environmental Toxicology Agriculture and Country Emerging Contaminants

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		2024 Vol. 44 (11): 0-0 [Abstract] ( 82 ) [HTML 1KB] [ PDF 269KB] ( 538 )

Air Pollution Control

	5921	Research progress and future prospects of atmospheric environment models in China
		WANG Ti-jian, LI Meng-meng, HAN Zhi-wei, ZHANG Hua, ZHOU Chun-hong, XIE Min, LI Shu, ZHUANG Bing-liang, WU Hao, QU Ya-wei, FU Tzung-may, MA Dan-yang, LI Ya-song
		This article offers a comprehensive overview of the history and key features of China’s atmospheric environment models, and also discusses the potential future research directions in this field. Since the 1960s, China has been engaged in the development and application study of atmospheric environment models, which have gone through different stages including transport diffusion models, acid deposition models, air quality models, climate-chemistry coupled models, and earth system models. China has developed its own atmospheric environment models with unique characteristics, improved international advanced models, and played a significant role in pollution prevention, environmental protection for major events, and climate change response. In the future, to improve the performance of atmospheric environment models in China and promote its open-source, more studies are required to focus on the formation mechanism of air pollution in model, retrieval of emission inventory, as well as development of dynamical emission model, multi-source observational data assimilation technique, ensemble forecast technique, unstructured grid system, and environment model based on artificial intelligence.
		2024 Vol. 44 (11): 5921-5933 [Abstract] ( 206 ) [HTML 1KB] [ PDF 454KB] ( 1178 )

	5934	Vertical distribution and combined pollution characteristics of aerosol and ozone in the Guangdong-Hong Kong-Macao Greater Bay Area from 2006 to 2020
		WANG Qing, DENG Tao, WU Dui, HE Guo-wen, ZHANG Xue, OUYANG Shan-shan, TAO Li-ping, ZHANG Ze-biao, WU Cheng, ZHOU Zhen
		In recent years, the concentration of particulate matter in the Guangdong-Hong Kong-Macao Greater Bay Area has decreased significantly, but O₃ pollution has continued to increase under the background of anthropogenic emission reduction. In this study, multi-source observation data of ground-based, tower-based, ozonesonde, aircraft (IAGOS), and satellites in the Greater Bay Area from 2006 to 2020 were used to analyze the three-dimensional spatial and temporal variation characteristics of aerosols, O₃ and related meteorological conditions, with special attention to the vertical distribution characteristics of aerosol and O₃, and the influence of the lower part of boundary layer aerosols on O₃ concentration. The results showed that the concentrations of surface PM₁₀decreased (-2.2μg/(m³ža)) from 2006 to 2020, while the concentrations of surface O₃ and boundary layer O₃ increased (+0.8μg/(m³ža), +0.6μg/(m³ža)). Surface PM_2.5 decreased (-1.5μg/(m³ža)) since 2014. There were differences and commonalities between vertical aerosol and O₃ distribution. The vertical extinction coefficient of aerosol (within 1000m) decreased with increasing height (average rate of change -0.06km^-1/hm), while the O₃ concentration increased with increasing height (average rate of change +1.4μg/(m³žhm)). Generally, both vertical aerosol and O₃ reached their lowest values in summer and both reached their highest concentrations in the free troposphere in spring. Since 2006, the average surface temperature increased by 0.05℃/a, the average relative humidity increased by 0.44%/a, and the average wind speed decreased by 0.02m/(s×a), which to a certain extent can explain the simultaneous increase/decrease of aerosol and O₃ concentrations in a given year. In summer, under the influence of the South China Sea monsoon, the relative humidity within the boundary layer was high, while in fall the temperature within the boundary layer was higher and the humidity was moderate, and this kind of meteorological conditions were more favorable for photochemical reactions. Based on the four years of observation of O₃ and PM₁₀ at Canton Tower, the high surface PM₁₀ value appeared at night, and the high PM₁₀value of 454m appeared in the afternoon and was strongly positively correlated with the O₃ concentration at 454m, which indicates that the secondary reaction of aerosols in the boundary layer in the late afternoon, as well as the backscattering of photochemical radiation by these secondary aerosols, may be one of the factors that exacerbate the O₃ pollution in the boundary layer. The results of the study will help deepen the understanding of the vertical distribution of aerosols and O₃ and the characteristics of the complex pollution in the Greater Bay Area.
		2024 Vol. 44 (11): 5934-5949 [Abstract] ( 140 ) [HTML 1KB] [ PDF 6908KB] ( 838 )

	5950	Influence of downward-mixing ozone in the residual layer on surface ozone—cases study of typical autumn ozone pollution processes in the coastal areas of Jiaodong Peninsula
		MENG He, WANG Wei, ZHANG Miao, DAI Wei, MA Yan, XU Yang
		Based on differential absorption ozone lidar and coherent Doppler wind lidar vertical observation, as well as surface pollutant concentration and meteorological data, a study was conducted in the coastal city of Qingdao of Jiaodong Peninsula, focusing on meteorological causes of typical ozone (O₃) pollution events occurred from October 16^th to 26^th, 2023. The study aimed to explore the vertical evolution in O₃ concentrations during the pollution events, as well as the influence of wind profiles on O₃ distribution vertically. Besides, contributions of downward mixing of residual layer O₃ affected on surface O₃ concentrations was also evaluated. The results indicated that there were two O₃ pollution events during the observation period: event I from the 17^th to 18^th, and event II from 22^nd to 25^th. O₃-8h concentrations on 18^th, 23^rd to 25^th were 197, 171, 179, and 169μg/m³, respectively. These two O₃ pollution events were associated with warming processes at 850hPa geopotential height, intensive solar radiation, nocturnal ground-based inversions, lower stable boundary layers (below 200m), and lower daily atmospheric boundary layer heights. These atmospheric meteorological conditions favored O₃ formation and air pollutants accumulation. Both two O₃ pollution events concluded with cold air advection from the north. Local O₃ production was identified as the primary cause of O₃ pollution in Jiaodong Peninsula. Persisting warmth, intense solar radiation, and unfavorable atmospheric circulation patterns led to continuous regional O₃ pollution. Moreover, transport of residual layer O₃ by the southwest low-level jet could exacerbated surface O₃ pollution within a range of 400~500km. Vertical mixing of residual layer O₃ was found to play a crucial role on surface O₃ concentrations, particularly during morning hours as the atmospheric boundary layer height increases. Between 7:00 and 12:00, the O₃ vertical transport flux in the boundary layer ranged from -20.2 to -36.0μg/(m²·s). On average, vertical mixing of residual layer O₃ contributed 26.4 % (15.1 %~43.2%) to surface O₃, with a highest contribution observed at 9:00. During event II, vertical mixing of residual layer O₃ contributed an average of 23.8 % (15.4 %~36.5 %) to surface O₃. There was no significant difference in vertical mixing contributions between pollution days and clean days. The study highlighted the importance of reducing local pollution emissions and enhancing regional collaborative control measures to effectively O₃ pollution prevention and control.
		2024 Vol. 44 (11): 5950-5960 [Abstract] ( 193 ) [HTML 1KB] [ PDF 4837KB] ( 679 )

	5961	Inversion of PM_2.5 in the Beijing-Tianjin-Hebei region using a random forest model based on GF-5B satellite
		HANG Rui-jie, ZHOU Chun-yan, CHEN Hui, ZHOU Wei, XIE Hui-zhen, CHEN Rui-zhi, WANG Zhong-ting
		This study utilizes aerosol optical depth (AOD) data derived from the domestic GF-5B DPC payload, ERA- 5meteorological data, NDVI data, DEM data, nighttime light data, and ground-based PM_2.5 measurements. Based on a random forest model, an AOD-PM_2.5 inversion model is developed to estimate the PM_2.5 concentration in the Beijing-Tianjin-Hebei region for the year 2022. The results showed that the model's coefficient of determination (R²) for the entire year was 0.80, with a root mean square error (RMSE) of 11.43 μg/m³. For the seasonal models, the R² values were 0.84, 0.71, 0.88, and 0.87 for spring, summer, autumn, and winter, respectively, with corresponding RMSE values of 9.50, 7.37, 9.71, and 11.32μg/m³. Both the annual and seasonal models demonstrated good simulation accuracy. The PM_2.5 concentrations in the Beijing-Tianjin-Hebei region in 2022 exhibited significant seasonal variation, with the highest concentrations in winter and the lowest in summer. The estimated annual average PM_2.5 concentration was 30.86μg/m³. During the summer and autumn, AOD was the primary factor influencing PM_2.5 concentrations, while in spring and winter, the boundary layer height and relative humidity were the main influencing factors.
		2024 Vol. 44 (11): 5961-5970 [Abstract] ( 115 ) [HTML 1KB] [ PDF 3829KB] ( 635 )

	5971	The spatiotemporal characteristics of PM_2.5 and O₃ in the Beijing-Tianjin-Hebei region and the health-based regional cooperative control strategy
		HUANG Zi-jian, DUAN Wen-jiao, QI Hao-yun, HOU Xiao-song
		In order to study the spatiotemporal characteristics of PM_2.5 and O₃ concentrations and health risks in the Beijing-Tianjin-Hebei region and their cooperative control regions, this study constructed a Beijing-Tianjin-Hebei composite pollution correlation network by quantifying the Composite Pollution Health Index, taking the cities as the nodes and the similarity of the composite pollution among the cities as the weights; and based on the Girvan-Newman community detection method, the Beijing-Tianjin-Hebei region was divided into three cooperative control regions for PM_2.5 and O₃. The average annual concentration of PM_2.5 in Beijing-Tianjin-Hebei decreases by 42.19% from 2017 to 2022, with a significant downward trend, while the average annual concentration of MDA8O₃ decreases by 1.85%, with a fluctuating trend; the areas with severe PM_2.5 are also the areas with deteriorating O₃, and spatially show the characteristics of "high in the south and low in the north"; The eastern densely populated cities represented by Beijing and Tianjin have high health risks of PM_2.5 and O₃ exposure, with October-March as the health control period for PM_2.5 and April-September as the collaborative health control period for PM_2.5 and O₃; Beijing-Tianjin-Hebei is divided into three cooperative control regions. The composite pollution characteristics of the three zones are more similar to each other.
		2024 Vol. 44 (11): 5971-5979 [Abstract] ( 117 ) [HTML 1KB] [ PDF 2215KB] ( 756 )

	5980	Chemical characteristics and variations of organic aerosols in Hangzhou during the 19^th Asian Games based on online measurements of organic molecular markers
		ZHU Shu-hui, LAI Yong, YAN Ren-chang, GAO Ya-qin, SHEN Jian-dong, WU Yu-hang, HUANG Cong-yan, YE Xu-hong, JIN Jia-jia, LIN Xu, WANG Yun-yun, ZHANG Tian, FEI Luo-lan, SHUAI Qi-fan
		Air quality in Hangzhou was greatly improved during the 19^th Asian Games with the implementation of temporary emission control measures. Observation data collected at the Asian Games Core Supersite show that average concentration of PM_2.5 during the Games declined by 18% and 71% compared with the periods before and after the Games, respectively. Among its major components, organic aerosols (OA) displayed largest decrease in average concentration by 32%. To further understand the chemical characteristics and formation variations of OA brought by emission reductions, a thermal desorption aerosol GC/MS (TAG) online system was adopted in this study to measure hourly concentrations of total 110organic molecular markers in OA at the same site. The results show that hopanes, which are mainly emitted from vehicles, dropped most significantly among primary organic molecular groups with a mass decrease ratio of 32%. The variations of αβ-norhanpe to EC and αβ-hanpe to EC mass ratios suggest that OA collected at the supersite was more influenced by diesel emissions before and after the Games. While during the Games, their mass ratios were closer to emission inventory obtained from gasoline vehicles, indicating that restriction measures executed in diesel vehicles remarkably lowered the concentration of primary OA. Among secondary organic molecular markers, hydroxyl-carboxylic acids and dicarboxylic acids were the two groups showing highest mass proportions in TAG-measured OA. Their average concentrations also decreased during the Games by 56% and 32%, respectively. Their correlations with other organic molecular groups in OA as well as volatile organic compounds (VOCs) in the gas phase suggest that dicarboxylic acids were formed via photochemical processing from various particular and gaseous precursors, including naphthalene-related, α-pinene-related, and isoprene-related secondary organic aerosol (SOA) tracers as well as VOC species such as aldehyde ketones, furans, terpenes. While hydroxyl-carboxylic acids were mainly secondarily produced from aromatic-related and α-pinene-related SOA tracers in the particle phase. The noticeable decreases in the concentrations of hydroxyl-carboxylic acids and dicarboxylic acids as well as their precursors during the Games imply that controlling anthropogenic VOCs emissions can effectively suppress the formation of secondary OA.
		2024 Vol. 44 (11): 5980-5989 [Abstract] ( 125 ) [HTML 1KB] [ PDF 2366KB] ( 564 )

	5990	Air pollution impact of thermal power industry in Shandong Province under carbon peak and carbon neutrality scenario
		WANG Sheng, ZHOU Bin, QU Jia-Bao, LI Jian-Hui, YU Li-Zhao, WU Xin, YANG Ying, XU Xin, BO Xin
		This study took Shandong Province, a major province of thermal power generation, as an example, calculated the emissions of atmospheric pollutants from thermal power under the scenario of carbon peaking and carbon neutrality, and adopted the CALPUFF model to simulate the contribution of SO₂, NO_x, PM₁₀,and PM_2.5 pollution from the thermal power industry in Shandong under different scenarios. The results show that under the carbon peak scenario, the emissions of SO₂, NO_x, PM₁₀,and PM_2.5 in the Shandong thermal power industry decreased by 2483.42, 23448.71, 364.31, and 341.01t, respectively, compared with the baseline scenario in 2018. The contribution concentration of thermal power to SO₂, NO_x, PM₁₀,and PM_2.5 in each city decreased by 0.22%~26.61%, 0.66%~51.21%, 0.63%~23.82%, and 4.36%~24.38%, respectively, compared with the baseline scenario concentration in 2018. Under the carbon neutral scenario, SO₂, NO_x, PM₁₀,and PM_2.5 in the thermal power industry in Shandong Province SO₂, NO_x, PM₁₀,and PM_2.5 emissions decreased by 10947.71, 44358.58, 1606.00, 1503.29t, respectively, compared with the 2018 base scenario. The contribution concentration of thermal power to SO₂, NO_x, PM₁₀, and PM_2.5 in each city decreased by 22.66%~44.14%, 7.10%~54.37%, 23.08%~42.02%, and 27.20%~42.44%, respectively, compared with the baseline scenario concentration in 2018. Under the scenario of carbon peak and carbon neutrality, thermal power generation is still the "ballast stone" for energy security and stable supply in Shandong Province, and the collaborative control of pollution reduction and carbon reduction is crucial for Shandong thermal power industry.
		2024 Vol. 44 (11): 5990-5998 [Abstract] ( 113 ) [HTML 1KB] [ PDF 1549KB] ( 606 )

	5999	A chamber study of gas-phase products formation by isoprene nocturnal ozonolysis
		TAN Yan, ZHANG Yu-jia, LIU Xiao, LIU Ting, MA Zi-zhen, ZHANG Hua-wei, LEE Shun-cheng
		A chamber experiment was conducted simulate the nighttime ozone oxidation process of isoprene. The concentration changes of gas-phase products in the isoprene-ozone reaction system were monitored in real-time using proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS). Furthermore, the production process of secondary organic aerosols (SOA) was assessed in real-time through scanning mobility particulate size spectrometry (SMPS). The findings revealed that under the conditions of a reaction temperature of (298 ±1) K and a relative humidity of 30%, isoprene was consumed by ozone, resulting in the formation of SOA. The concentration of SOA peaked at 3.14µg/m³ approximately 4 hours into the reaction. The main gas-phase products of the nighttime ozone oxidation reaction of isoprene were oxygenated volatile organic compounds (OVOCs) ranging from C₁ ~ C₄, including formaldehyde (HCHO), formic acid (CH₂O₂), acetic acid (C₂H₄O₂), acetone (C₃H₆O), propionic acid (C₃H₆O₂), methacrolein (MACR), methyl vinyl ketone (MVK), and methacrylic acid (C₄H₆O₂), and the yields of these products varied with the ratio of ozone to isoprene. Notably, HCHO and MACR + MVK exhibited the highest yields among all oxidation products. When the ozone/isoprene ratio ranged from 0.5 to 6.8, the yield ranges were 17.0% to 35.6% for HCHO and 59.3% to 89.5% for MACR + MVK. Additionally, NO₂ was found to inhibit the production of HCHO and MACR + MVK, while other OVOCs displayed a mild negative correlation with increasing NO₂ concentrations. The nighttime oxidation of isoprene plays a significant role in the formation of OVOCs and SOA.
		2024 Vol. 44 (11): 5999-6006 [Abstract] ( 110 ) [HTML 1KB] [ PDF 1273KB] ( 591 )

	6007	Characteristics of CH₄ and VOC_s emissions from municipal solid waste landfills in China
		DENG Tian-le, MA Zhan-yun, LIU Shu-le, GAO Qing-xian, GAO Wen-kang, LI Hua-sheng, XIE Li-yong
		To assess the emission status of primary gas emissions such as methane (CH₄) and VOCs from municipal solid waste (MSW) landfills in China comprehensively and promote the understandings of the reduction potential of air and greenhouse gas emissions in waste sector, this study collected the fundamental information of waste treatment in 695 cities nationwide. Based on the emission factor method, it calculated the emissions of CH₄, VOCs, and other typical air pollutants from urban landfills in China from 2002 to 2022. The results show that the MSW disposed in landfills in China has been decreasing after 2009. The decline rate was lowest in 2021 (1.39%), while highest in 2020 (12.45%). In 2022, the total emissions of CH₄, NH₃, VOCs, TSP, PM₁₀, and PM_2.5 from urban landfills in China were 4.09×10⁶, 17.04, 4.75×10⁴, 14.09, 6.66, and 1.00 ton respectively. In terms of spatial distribution, the regions with significant emissions of CH₄ and volatile organic compounds (VOCs) from MSW landfills in China have experienced a southward migration. Since 2018, there has been a sustained reduction in the emissions of these air pollutants, with the rate of decline ranging from a minimum of 2.75% in 2018 to a maximum of 41.57% in 2022. Post-2020, emissions of CH₄have followed a similar downward trajectory, with a minimum reduction of 4.53% observed in 2020 and a peak decrease of 13.56% in 2022. Over the past few years, there has been a notable decrease in the CH₄ and VOCs emissions from landfills in China. This trend correlates with a reduction in the volume of waste being disposed in the landfills, where the rate of decline for air pollutants has exceeded that observed for CH₄ emissions.
		2024 Vol. 44 (11): 6007-6017 [Abstract] ( 105 ) [HTML 1KB] [ PDF 4146KB] ( 580 )

	6018	Emission characteristics and influencing factors of tire wear particles from light-duty vehicles
		HAN Quan-kang, CHEN Hong-fei, ZU Lei, ZHANG Yu-zhe, WANG Yun-jing, XIE Pei-yuan, ZHU Ren-cheng
		To investigate the emission characteristics of tire wear particles (TWPs), tire wear emission tests based on the real-world driving were carried out on typical light-duty vehicles. The physicochemical characteristics of TWPs were systematically analyzed, along with the effects of environmental temperature, vehicle type, curb weight, and tyre position. The results showed that the main metallic elements in TWPs were Si, Ca, Na, etc. The sizes of TWPs were concentrated in 5~30µm and the shapes were spherical, rod-like, aggregated, and irregular, etc. The average OC/EC value was 4.8. The average emission factor of TWPs in autumn and winter (112.7mg/km) was slightly higher than those in spring and summer (104.6mg/km). A positive correlation was observed between the curb weight and the emission factor of the TWPs. The emission factors of the TWPs of electric vehicles (70.2~177.6mg/km) were slightly higher than those (54.2~155.2mg/km) of fuelled vehicles. The front tires of light-duty vehicles emitted 6%~30% more TWPs than the rear tires on average. It was estimated that the total annual TWPs emissions from light-duty vehicles in China reached 481,000 tons in 2022, exceeding the exhaust particulate matter emissions.
		2024 Vol. 44 (11): 6018-6024 [Abstract] ( 95 ) [HTML 1KB] [ PDF 2595KB] ( 733 )

	6025	Applicability of four types of meteorological data to Fukushima nuclear accident ¹³⁷Cs simulations
		LI Huan-ting, YANG Li, SONG Jia-yue, LI Xin-peng, FANG Sheng
		The local-scale atmospheric transport of ¹³⁷Cs following the Fukushima accident was investigated using ensemble modelling based on four different meteorological inputs (FNL reanalysis data, ERA-Interim reanalysis data, GFS analysis and forecast data, and MEA field meteorological observations data). Two different types of atmospheric transport model were used, i.e., regional-scale meteorological model WRF and Lagrangian particle dispersion model FLEXPART. The influence of different meteorological data was evaluated based on the monitoring data from two monitoring stations in Futaba and Naraha. The simulations showed that FLEXPART successfully reproduced most of the peaks at both stations using all four types of meteorological data (average FAC10 of Futaba:0.57; average FAC10 of Naraha:0.58). The simulations using ERA-Interim and MEA reproduce more peak observations and achieve more satisfactory statistical metrics than the others. The simulated spatial ¹³⁷Cs distribution using four meteorological data were slightly different. The results of ERA-Interim and MEA showed a wider range of plumes, better reproducing the observations. Therefore, ERA-Interim and MEA are recommended for simulating the atmospheric ¹³⁷Cs transport following the Fukushima nuclear accident at local scale.
		2024 Vol. 44 (11): 6025-6035 [Abstract] ( 103 ) [HTML 1KB] [ PDF 3087KB] ( 612 )

	6036	The synergy between K⁺-induced enhanced acidity and active oxygen in Mn-Ce solid solution for promotion of NH₃-SCR
		CHEN Xi, WANG Xao-yan, LI Qiao-yan, WANG Meng-xue, LIANG Mei-sheng
		In this work, K ions were successfully introduced into the lattice of as-prepared Mn-Ce solid solutions (MnCeO_x) by a hydrothermal method, and that was applied in NH₃-SCR. The Mn-O bonding was deeply weakened, leading to a better reducibility and oxygen desorption capacity of the K-contained catalysts according to H₂-TPR and O₂-TPD. Furthermore, the introduction of K ions could facilitate the adsorptive capacity of Brønsted acid sites for NH₃ due to the enhanced electron transfer between Mn/Ce elements according to the characterizations of XPS, NH₃-TPD and in situ DRIFT. Then, the synergy among the acidity and adsorbed active oxygen could promote the activities of catalyst MnCeK_yO_x on NH₃-SCR. With the proportion of 1:5:5 for the amounts of K, Ce and Mn elements, the best performed catalyst MnCeK₁O_x could achieve 94.6% conversion of NO at a lower temperature of 120℃. The broader temperature ranging from 40~260℃ is beneficial for the conversion of NO at many conditions. Finally, in situ DRIFTs of NH₃ and NO adsorption on MnCeO_x and MnCeK₁O_x suggested that the reaction was more sensitive to the adsorption of NH₃ than NO. For MnCeO_x, NH₃ was primarily bound on Lewis then Brønsted acid sites, resulting in the rapid aggregation of both monodentate and bidentate nitrate. For MnCeK₁O_x, the simultaneous adsorption of NH₃ on Lewis and Brønsted acid sites led to less accumulation of intermediates like bidentate nitrate. The results indicated that the introduction of K ions could efficiently improve the activity of Mn-Ce solid solution in NH₃-SCR reaction.
		2024 Vol. 44 (11): 6036-6046 [Abstract] ( 104 ) [HTML 1KB] [ PDF 2340KB] ( 668 )

	6047	Preparation of RuCeTi catalyst and catalytic oxidation of chlorobenzene
		WANG Meng-xue, CHEN Xi, JIA Zi-liang, Li Shu-ning, LIANG Mei-sheng
		In this paper, a catalyst support (CeTi) with abundant strong acidic sites was prepared by sol-gel method, and Ru was loaded on to form a RuCeTi catalyst by chemical reduction process using a certain reductant. And that was used for the catalytic oxidation of chlorobenzene (CB). With the help of characterizations like XRD, HRTEM, XPS, H₂-TPR, and in-situ DRIFTS, it showed that the interaction between Ru and CeO₂ increased the valence state of Ru species, leading to the promotion of redox ability of RuO₂ and the deep oxidation of chlorobenzene. Further the abundant strong acidic sites of the CeTi support provided the adsorption sites for CB. The activity tests showed that the CO₂ selectivity and durability of RuCeTi were significantly enhanced, with a 98% of selectivity and 24h on-stream test at 1000×10^-6 of CB concentration without deactivation. And that could be derived from the synergistic combination of reactive oxygen species and acidic sites.
		2024 Vol. 44 (11): 6047-6056 [Abstract] ( 110 ) [HTML 1KB] [ PDF 1795KB] ( 612 )

Water Pollution Control

	6057	Characteristics of anaerobic ammonium oxidation (anammox) system featuring alternating influent at variable frequencies from top and bottom
		LI Dong, TAO Bo, ZHANG Jie
		The granulation process of anaerobic ammonia oxidation sludge is slow and easily affected by hydraulic shear force and fluctuation in substrate concentration. At the same time, the mass transfer performance of granular sludge deteriorates with the increase of particle size, which leads to the limitation of nitrogen removal performance of the system. In this paper, a top/bottom variable frequency alternating influent operation mode was proposed, which extends the inlet duration and introduces recirculation to provide sufficient hydraulic shear forces. By varying the inlet positions and frequencies, this method effectively reduces the impact load of substrate concentration on Anammox bacteria and enhances the system's nitrogen removal performance. The changes in sludge concentration, particle performance, EPS(Extracellular Polymeric Substances) secretion and nitrogen removal stability during operation were investigated. The results show that under this influent mode, the removal rate of total nitrogen reached 84.80 %, with an average particle size of 783.67μm, and EPS content of 169.13mg/gVSS. After increasing the influent load, the maximum concentration of free ammonia was 9.70mg/L, which has no inhibitory effect on the system. Microscopic observations revealed darker granule colors and higher heme c content, indicating better AnAOB activity. The high-throughput sequencing results showed that the top/bottom variable frequency alternating influent operation mode can greatly increase the abundance of anaerobic ammonia oxidizing bacteria Candidatus_Brocadia in the system, reaching a peak of 43.59% when the alternating frequency was 3times. The influent mode accelerates the mixing of sludge and substrate, shortens the granulation process, improves sludge activity and resilience to shock loads, and realizes the stable operation of the anaerobic ammonia oxidation system.
		2024 Vol. 44 (11): 6057-6067 [Abstract] ( 99 ) [HTML 1KB] [ PDF 1569KB] ( 526 )

	6068	Performance of autotrophic/heterotrophic biological nitrogen removal process based on organic energy conversion
		LI Wei, LI Xiang, YUAN Yan, HUANG Yong, FENG Zhen, LI Peng-fei
		In order to solve the problems of low energy recovery rate and high energy consumption of traditional nitrification and denitrification in the treatment of high organic carbon and high ammonia wastewater by the anaerobic internal circulation reactor (IC)-anaerobic aerobic process (AO). Based on partial nitrification/anaerobic ammonia oxidation (PN/A), and IC high-efficiency methanation, complete autotrophic nitrogen removal process (CANON) to treat this kind of wastewater was designed, and the operating characteristics of IC-CANON in the energy recovery and nitrogen removal process were discussed, and the differences between IC-CANON and traditional IC-AO energy recovery, nitrogen removal stability and energy consumption level were evaluated. The results showed that when the C/N of IC effluent was 0.5~1, the nitrogen removal rate (NRR) of the CANON process reached the highest of 0.24kg/(m³·d), the nitrogen removal efficiency (NRE) was (76.2±5)%, and the minimum nitrogen removal contribution rate of Anammox was more than 70%. When influent C/N was 1.9~4, the NRR of first AO reached the highest of 0.14kg/(m³·d), and the NRE was (89.6±0.9)%. When the nitrogen load rate (NLR) of influent fluctuated at 0.22~0.32kg/(m³·d), the minimum contribution rates of CANON process NRE and Anammox remained above 70% and 65%, respectively. When the influent C/N increased to 2.2, the activity of Anammox in CANON was inhibited, and the NRE decreased from 76% to 45.4%. CANON had a strong resistance to NLR impact, but a poor resistance to organic load impact. Under the fluctuations of C/N and NLR of 0.6~6.6kg/(m³·d) and 0.06~0.16kg/(m³·d), the NRE of the first AO remained at about 90%, compared with Canon, the AO process had well resistance to NLR and organic load impact at the same time. When the NRR of the CANON process reached more than 0.21kg/(m³·d), the energy consumption of nitrogen removal is 3.5~3.6kWh/kgN, which can save (77.8±1.8)% compared with the AO process under the same influent and effluent, and the IC energy recovery rate increased from 62.1% to 89.2%.
		2024 Vol. 44 (11): 6068-6076 [Abstract] ( 110 ) [HTML 1KB] [ PDF 1481KB] ( 621 )

	6077	Unravelling the mechanism of ibuprofen's effect on aerobic granular sludge and its removal mechanism
		TANG Yi, ZHANG Bing, FAN Jia-wei, SHI Wen-xin
		The mechanism of ibuprofen's (IBP) effect on aerobic granular sludge (AGS) was explored and the efficacy and mechanism of IBP removal by AGS system were analyzed. The presence of IBP had little effect on ammonia nitrogen removal in AGS system, and slightly inhibited the removal of organic matter, total nitrogen, and phosphorus. The AGS system was highly resistant to 0.5mg/L IBP, whereas 1.0~5.0mg/L IBP reduced the secretion of EPS, lowered the performance of sludge settleability, and affected the enrichment of functional bacteria, which was detrimental to the stability of the AGS system. The results of 120 consecutive days of experiment showed that AGS could remove 0.5~5.0mg/L of IBP through adsorption and degradation. Adsorption isotherm modelling indicated that AGS adsorbed IBP mainly through multilayer adsorption. The degradation pathways of IBP include decarboxylation and hydroxylation. The prolonged presence of IBP enhanced the proliferation of drug-resistant microorganisms, but altered the community structure and reduced microbial diversity and abundance, with Thiothrix, in particular, becoming the dominant genus. In conclusion, AGS technology has good application prospects for treating wastewater containing anti-inflammatory drugs (IBP), but the high concentration of IBP has a large negative effect on the performance of the AGS system, which requires more attentions.
		2024 Vol. 44 (11): 6077-6087 [Abstract] ( 110 ) [HTML 1KB] [ PDF 2824KB] ( 933 )

	6088	Response and transcriptional analysis of DvH cathode biofilm with the effect of magnetite
		TENG Min, ZHU Xi, ZENG Cui-ping, HU Jia-ping, LIU Guang-li, LUO Hai-ping
		This study investigated the response mechanism of the biofilm by constructing a Desulfovibrio vulgaris Hildenborough (DvH) biocathode, under the influence of magnetite nanoparticles (MNPs). The results showed that the conversion rate of SO₄^2- to S^2- of the biocathode mediated by MNPs increased from 6.8% to 37.9%, compared to the group without MNPs. The results of the linear sweep voltammetry test revealed that, within the potential range of 0~-0.81V, the cathodic current observed in the group with MNPs was higher than that of the control group, suggesting that MNPs enhance the electrocatalytic activity of the cathodic biofilm. The comparative transcriptome analysis of DvH cathodic biofilm revealed that MNPs can facilitate hydrogen utilization in DvH by upregulating genes encoding [FeFe] hydrogenase, Hmc, and ATP synthase. In addition, genes encoding sulfate adenylyltransferase and adenylylsulphate reductase, both crucial enzymes in sulfur metabolism, were upregulated with MNPs addition, which contributed to an improved conversion rate of SO₄^2--S^2-. MNPs upregulated genes related to Flp/Tad pili assembly and PEP-CTERM protein, thereby augmenting the adhesion of DvH and promoting biofilm formation on the cathode. These findings contribute to a novel theoretical framework for the development of highly efficient microbial cathodic electrochemical systems.
		2024 Vol. 44 (11): 6088-6095 [Abstract] ( 90 ) [HTML 1KB] [ PDF 1265KB] ( 567 )

	6096	Effects of complex carbon sources on phosphorus enrichment and microbial communities in biofilm systems
		BI Zhen, FU Hao, WANG Xue-ling, YUAN Yi-na, HUANG Yong
		In this study, the effects of complex carbon sources on the performance of phosphorus enrichment and characteristics of microbial community were investigated in an anaerobic/aerobic alternatively operational biofilm reactor by using synthetic sewage wastewater containing VFAs, glucose and amino acid. The results showed that the utilization efficiency of complex carbon source reached 72.5% by adjusting the parameters of anaerobic hydraulic retention time, aerobic pH and DO concentration. The removal efficiency of total phosphorus and total nitrogen were 99.8% and 76.5%, respectively, with the concentration of phosphorus enrichment solution exceeding 50mg/L. The utilization complex carbon source changed the energy metabolism pathway of biofilm. Specifically, amino acids may participate in phosphorus metabolism as intracellular energy storage substances to compensate for the energy deficiency caused by PHA and glycogen, thus maintaining a good phosphorus removal and enrichment performance of the biofilm system. Meanwhile, the content of intracellular organophosphorus (OP) fluctuated with the activity of phosphorus uptake and release, whereas the content of inorganic poly-phosphorus (IP) changed a little. This phenomenon indicated that the phosphorus metabolism transferred from the IP pathway to the OP pathway. The abundance of hydrolytic bacteria and fermentative bacterium in biofilm increased significantly, which could provide small molecular organic carbon for phosphorus-accumulating bacteria (PAOs) metabolism, thus contribute the satisfactory performance of phosphorus removal and enrichment. The conclusion of present study exhibited the potential of biofilm system to simultaneously realize the phosphorus enrichment and total nitrogen removal via using complex carbon sources in sewage wastewater.
		2024 Vol. 44 (11): 6096-6104 [Abstract] ( 106 ) [HTML 1KB] [ PDF 1575KB] ( 475 )

	6105	Modeling, optimization, and control of biofilter microbial electrolysis cells
		HAN Xu-wei, WANG Li, WANG Jin
		A physical model and mathematical model of the biofilter microbial electrolysis cell (BF-MEC) system were established to study the system structure, reaction mechanism,and influencing factors, and describe the bioelectrochemical consumption substrate process of the BF-MEC system. The model parameters were estimated according to the experimental results obtained in the continuous flow biofilter. Using CH₃COO^-, NH₄⁺, and NO₃^- to simulate wastewater, we explored the effects of the system's optimal electrode spacing, electrode position, applied voltage, hydraulic retention time (HRT), and microbial attachment amount on the system efficiency, and optimized and controlled the system. The simulation results showed that the optimal electrode structure of the BF-MEC system was an electrode spacing of 100mm and the cathode was 150mm from the outlet of the experimental column. When the hydraulic retention time of sewage in the system was greater than 72h, the effluent pollutants could meet the national reclaimed water reuse standard. When the reclaimed water quality was Class B of level one, the minimum voltage required to completely remove pollutant ions was 0.55V. When the microbial attachment amount was greater than 50%, the removal rate increased with the increase of the attachment amount. When the attachment amount reached 93.75%, a small voltage of 0.25V could make the removal rate of each ion in sewage greater than 99%.
		2024 Vol. 44 (11): 6105-6113 [Abstract] ( 105 ) [HTML 1KB] [ PDF 3149KB] ( 460 )

	6114	Nitrogen removal and power production efficiency of iron anode/biocathode single-chamber cell
		XIA Da-peng, YUAN Lin-jiang, CHEN Xue-jiao, LIU Yan, WANG Jing-hua, MA Yan-chen
		The denitrification and electricity generation efficiency of inorganic wastewater from iron anode biocathode single-chamber cells were investigated, and the dominant bacterial community structure of the biocathode was examined. The results showed that the internal resistance of the single-chamber cell was only 224.1 Ω under the condition of external 1000 Ω resistor and 40mg/L nitrate-nitrogen feed water, and the maximum power density reached 1.82W/m³ with the total nitrogen removal rate of 40%. After lowering the external resistance and nitrate-nitrogen load, the cell could be stably operated and treated inorganic wastewater with a nitrate-nitrogen load of 20mg/L under the external 200 Ω resistance, and the total nitrogen removal rate reached 95.8% within 2d. The maximum nitrate-nitrogen removal load was 0.0102kgNO₃^--N/(m³·d), which was a one-fold increase in nitrate-nitrogen removal load, indicating that the single-chamber iron-anode biocathode cell has a good capacity to remove low concentrations of nitrate-nitrogen in inorganic wastewaters. Analysis of the biocathode community showed that the diversity of the biocathode community was reduced compared with that of the inoculated sludge, and the absolute dominant genus was Thiobacillus, with a relative abundance of 40.8%, which was the main genus for cathodic electroautotrophic denitrification.
		2024 Vol. 44 (11): 6114-6121 [Abstract] ( 118 ) [HTML 1KB] [ PDF 2646KB] ( 503 )

	6122	Modified biochar activated persulfate for degradation of tetracycline
		WANG Shi-sheng, YANG Yu, SHENG Guang-hong, LIU Yi-yun, LI Shen-bo
		Tetracycline hydrochloride (TC) degradation was investigated utilizing hydrogen peroxide modified magnetic biochar (H₂O₂modified biochar, HMB) as an activator of peroxydisulfate (PDS), with a focus on assessing the impact of initial pH on TC degradation kinetics. The underlying reaction mechanisms and degradation pathways of HMB-activated PDS for TC degradation were elucidated through a series of experimental techniques, including quenching tests, electron paramagnetic resonance (EPR) spectroscopy for identifying active species, X-ray photoelectron spectroscopy (XPS) analysis, density functional theory (DFT) calculations, and liquid-liquid mass spectrometry (LC-MS) detection. Hydrogen peroxide modification significantly enhanced TC removal, achieving a removal rate of 83.9% under the specified conditions of TC concentration (20mg/L), PDS concentration (1mmol/L), and HMB dosage (0.5g/L). This efficacy surpassed that of PDS alone or the unmodified biochar system, albeit exhibiting a decrease in removal efficiency with rising pH levels. Quenching tests and EPR analyses unveiled both radical and non-radical pathways contributing to TC degradation, the active species mainly includes: SO₄^.-、·OH、O₂^.-and ¹O₂. XPS analysis identified carbonyl (C=O) functionalities as the primary active sites responsible for TC degradation within the HMB/PDS system. Complementary DFT calculations were employed to quantitatively assess the contribution of C=O moieties to the HMB/PDS-mediated degradation process. Furthermore, LC-MS analyses coupled with DFT calculations delineated two distinct degradation pathways for TC, involving mechanisms such as deamidation, hydroxylation, demethylation, and dehydration ring opening.
		2024 Vol. 44 (11): 6122-6131 [Abstract] ( 152 ) [HTML 1KB] [ PDF 2937KB] ( 565 )

	6132	Mitigation of organic fouling of ultrafiltration membrane by peroxymonosulfate activated by activated carbon loaded with CoFe₂O₄
		WANG Qing-yun, LI Kai, WEN Gang, HUANG Ting-lin
		Activated carbon loaded with CoFe₂O₄ (CoFe₂O₄/PAC) was synthesized using the sol-gel method, and its efficiency and mechanism for activating peroxymonosulfate (PMS) for mitigating organic fouling of ultrafiltration membrane was investigated. The results indicated that pretreatment of humic acid (HA) solution by CoFe₂O₄/PAC+PMS significantly alleviated membrane fouling. Compared with pretreatment by PAC+PMS, specific flux was increased by 55% after CoFe₂O₄/PAC+PMS pretreatment, and reversible and irreversible fouling resistance were decreased by 62% and 51%, respectively. The CoFe₂O₄/PAC+PMS pretreatment exhibited high removal efficiency for effluent organic matter (EfOM) of wastewater treatment plant, with the removal rate for DOC reaching 76.4%, and the removal rate for main fluorescence components reaching 53.1%~67.7%. Moreover, organic matter with higher molecular weight was preferentially removed. Therefore, CoFe₂O₄/PAC+PMS pretreatment of EfOM resulted in 69% and 67% reduction of the reversible and irreversible fouling resistance, respectively. Additionally, CoFe₂O₄/PAC exhibited good magnetic separation performance and reusability.
		2024 Vol. 44 (11): 6132-6138 [Abstract] ( 89 ) [HTML 1KB] [ PDF 1079KB] ( 510 )

	6139	The operational efficiency and pollution characteristics of a two-stage filtration AnMBR reactor
		XIA Zhi-heng, LI Ying-hao, JIANG Zhao, JIA Meng-fei, WANG Hong-chen, QI Lu, LIU Guo-hua
		A two-stage filtration AnMBR (F-AnMBR) system was constructed, consisting of a primary filter with polymer filter cloth and a dynamic membrane formed on its surface, along with a secondary filter system utilizing polyvinylidene fluoride (PVDF) ultrafiltration membranes. This system was designed to evaluate its effectiveness in treating low-concentration municipal wastewater. Hydrophilic polyamide filter cloth was selected, featuring an 80μm mesh that effectively intercepts sludge at a flux of 12LMH. Following the formation of the dynamic membrane, the total suspended solids (TSS) interception rate exceeded 88%, indicating its suitability for F-AnMBR applications. The primary filtration significantly enhanced the anti-fouling properties of the AnMBR, with the critical flux of the PVDF ultrafiltration membrane increasing from 6LMH to 12LMH. This improvement was accompanied by a notable reduction in the rate of membrane fouling and an increase in the transmembrane pressure difference. Analyses revealed that the dynamic membrane component reduced membrane fouling substances, such as mixed liquor suspended solids (MLSS), mixed liquor volatile suspended solids (MLVSS), and extracellular polymeric substances (EPS) in the membrane pool by over 50%, effectively delaying the formation of the ultrafiltration membrane cake layer contamination. However, the dynamic membrane's ability to intercept soluble microbial products (SMP) was relatively limited, achieving only a 19.34% reduction in soluble protein content, which constrained the overall improvement of gel layer contamination.
		2024 Vol. 44 (11): 6139-6147 [Abstract] ( 104 ) [HTML 1KB] [ PDF 1940KB] ( 470 )

	6148	Efficacy of sewage sulfide removal by co-aeration of scrap iron filings
		ZHAO Hang, ZHANG Zhi-qiang, JIN Feng, LU Jin-suo
		The iron-oxygen-sulfide control system was constructed by the synergistic aeration technology through the processing of industrial scrap irons into the wastewater. The scrap irons were used to enhance the oxidation process of sulfide by oxygen to improve the inefficiency of traditional aeration and oxygenation to control sulfide in the water phase. A simulated wastewater pipeline reactor was constructed, and the iron-oxygen system composed of scrap iron filings and dissolved oxygen was evaluated for the control of sulfide by regulating the amount of scrap iron filings and the pH value of wastewater. The iron-oxygen system was compared with the direct catalytic oxygen oxidation process of Fe²⁺ and Fe³⁺, and its sulfide control mechanism was explored by the first-order rate equation of total sulfide concentration, and the effectiveness of the iron-oxygen system for the long-term control of sulfide was verified in a continuous flow reactor. The results showed that the sulfide in the wastewater could be removed nearly 100% within 10min when the dosage of scrap iron filings was above 40g/L, and the increase in pH of the wastewater was favorable to the removal of sulfide. In a 30 day continuous flow test, the sulfide concentration was below the detection limit at a gas-to-water ratio of (2 + 1.25)% iron filings, and the average H₂S concentration in the gas-phase space of the reactor was maintained at 20.5×10^-6.
		2024 Vol. 44 (11): 6148-6155 [Abstract] ( 104 ) [HTML 1KB] [ PDF 1724KB] ( 442 )

	6156	Morphology, distribution and removal of microplastics in municipal wastewater plants by traditional oxidation ditch technology
		QI Jie, WANG Wei, LIU Xu-guang, MENG Xin, ZHAI Shi-jiao, SUN Guang-yin
		In order to investigate the morphological characteristics and removal patterns of microplastics in urban wastewater plants in China, especially oxidation ditch process wastewater plants, the presence patterns and removal efficacy of MPs in each treatment unit of a two-phase project of an oxidation ditch process wastewater plant in Handan City were thoroughly analyzed. The results showed that the main shape of MPs was fibrous, accounting for 56.5%, followed by fragments and films, with particles accounting for the smallest proportion at only 4.0%. The particle size range was mainly between 150 and 5000μm, with MPs in the 150~500μm range accounting for the highest proportion at 43.0%. The main types were polyethylene, polyester, and polypropylene, accounting for 28.9%, 17.3%, and 22.5%, respectively. The analysis of the effect of shape and particle size on removal efficacy revealed that fibrous MPs were the most difficult to remove, and as particle size decreased, the difficulty of removal increased. The overall removal rates for the first phase of the plant and the expansion project were (92.0 ±2.5)% and (83.6 ±1.6)%, respectively. The analysis of removal rates for each process level and treatment unit showed that the key roles in removal were played by secondary treatment and deep treatment, with the treatment unit being the oxidation ditch sedimentation tank. The main mechanisms were physical sedimentation and retention in the filtration tank.
		2024 Vol. 44 (11): 6156-6163 [Abstract] ( 101 ) [HTML 1KB] [ PDF 1459KB] ( 529 )

	6164	Efficacy and mechanism of combined inactivation of fungal spores by peracetic acid pretreatment and UV combined
		WANG Jing-yi, WU Ge-hui, WAN Qi-qi, HUANG Ting-lin, WEN Gang
		The study investigated the effects and mechanisms of fungal spore inactivation by pre-exposure to peracetic acid (PFA) combined with ultraviolet (UV) light and subsequent PFA treatment. It was found that PFA, as an effective disinfectant, could produce strong oxidative effects under low-pressure UV activation, disrupting the cell wall structure of fungal spores and thereby achieving inactivation. The results indicated that PFA pretreatment could enhance the subsequent UV/PFA combined disinfection process. Under the same UV and PFA dosage conditions, after 12minutes of PFA pretreatment followed by UV inactivation, the inactivation rates of Aspergillus niger and Aspergillus flavus increased to 3.67-log and 2.51-log, respectively, which were 1.21 and 1.17 times the effect of direct UV/PFA treatment. Additionally, the study examined the influence of pretreatment time, PFA concentration, pH value, and humic acid concentration on the inactivation effect. Increasing the pretreatment time and PFA concentration significantly improved the inactivation efficiency, while alkaline conditions and high humic acid concentrations were detrimental to the inactivation effect. Flow cytometry analysis revealed that the PFA-UV/PFA combined treatment caused more severe damage to the cell membrane and significantly increased reactive oxygen species levels. The generation of more hydroxyl radicals and stronger synergistic effects were key factors in enhancing the inactivation effect. Furthermore, the PFA-UV/PFA treatment was more effective in inhibiting the regeneration ability of incompletely inactivated fungal spores compared to the UV/PFA treatment alone. Compared to the PAA-UV/PAA system, the PFA-UV/PFA combined inactivation system demonstrated higher potential and efficiency in inactivating fungal spores.
		2024 Vol. 44 (11): 6164-6173 [Abstract] ( 91 ) [HTML 1KB] [ PDF 3345KB] ( 575 )

	6174	The influence of adsorbents on the concentration efficiency of municipal wastewater
		HAO Li-tu, YANG Xiao-huan, TIAN Duan-yun, XIA Si-lian, CHEN Rong
		In order to investigate the effects of different adsorbents on carbon source concentration and membrane separation in the coagulation adsorption microfiltration process, this study used polyaluminum chloride (PACL) as a coagulant, and compared three types of adsorbents: powdered activated carbon (PAC), biochar (BC), and magnetic biochar (Fe-BC). The concentration efficiency, membrane fouling characteristics, methane production potential, and microbial community analysis of the concentrate were revealed. Content of COD, protein, and total phosphorus in the concentrate was significantly increased by the addition of adsorbents. The optimal concentration efficiency of the PAC group was 81.8%, and the protein content was about 2.4 times that of the control group. However, the enrichment effect of polysaccharides and total nitrogen was not significant. The membrane fouling of the BC group concentrate was found to be lower. A membrane resistance of 3.31×10⁸m^-1 caused by the concentrate was lower than that of the AC group (4.61×10⁸m^-1) and the Fe BC group (4.13×10⁸m^-1). In addition, the relative abundance of Proteobacteria, which are prone to membrane fouling, in the BC group concentrate was lower. The higher methane production potential of the BC group was due to the higher abundance of Bacteroidota, which participated in EPS and floc formation in the concentrate. The high abundance of Firmicutes involved in the hydrolysis and acidification process in the Fe BC concentrated solution provided favorable conditions for improving the methane production rate.
		2024 Vol. 44 (11): 6174-6180 [Abstract] ( 115 ) [HTML 1KB] [ PDF 1574KB] ( 599 )

	6181	Preparation of TiO₂ nanobelts loaded RuO₂ anode and the research of its ammonia oxidation performance
		LIU Guo-hua, LI Qian-gang, ZHANG Tong-tong, DU Hong-biao, XIAN Guang, ZENG Fan-gang, QI Lu
		In order to further improve the ammonia removal efficiency of the chlorine-mediated electrochemical advanced oxidation (Cl-EAO) technology, a new TiO₂ nanobelts loaded RuO₂ anode (TiO₂ NBs-RuO₂) was prepared in this study. Based on the investigation of its material and electrochemical properties, the ammonia oxidation performance of the anode was explored under different conditions, and the ammonia oxidation mechanism was explored by combining electron paramagnetic resonance (EPR) and free radical inhibition assays. The material characterization results indicated that RuO₂ was loaded on the surface of TiO₂ nanobelts uniformly, which formed a porous and stable structure, and the nanobelts diameter was within 100nm. The electrochemical characterization results indicated that TiO₂ NBs-RuO₂ anode has inhibited the oxygen evolution reaction and improved the current efficiency of the chlorine evolution reaction. The ammonia oxidation process of TiO₂ NBs-RuO₂ anode followed zero order reaction kinetics, and the ammonia nitrogen removal efficiency reached over 99.6% within 50min, which was significantly higher than unmodified Ti-RuO₂ anode and TiO₂-RuO₂ anode. Moreover, its ammonia oxidation rate increased with the increase of initial ammonia nitrogen concentration, initial chlorine concentration, initial pH, and current density. It was found that the ClO· played the most important role in the ammonia oxidation process. In addition, this study compared the TiO₂ NBs-RuO₂ anode and the most common commercial Ti-RuO₂ anode and found that the ammonia oxidation rate of TiO₂ NBs-RuO₂ anode was 29.7% higher than the commercial anode, and the energy consumption ratio and nitrate nitrogen yield of TiO₂ NBs-RuO₂ anode were also lower than the commercial one.
		2024 Vol. 44 (11): 6181-6193 [Abstract] ( 103 ) [HTML 1KB] [ PDF 3319KB] ( 499 )

	6194	Influence of ion cluster on phosphorous recovery efficiency in CaP crystallization system
		LI Yi-nan, NIE Xiao-bao, WAN Jun-li, JIANG Heng, WANG Guo-qi, OU Yang-shuai, WANG Zheng-bo
		To improve the P recovery efficiency of CaP crystallization from wastewater, ion cluster presented in CaP crystallization system and its effects on P recovery were studied. The results indicate that in-situ monitoring of free Ca concentration with selective electrode, combined with ex-situ analysis results of crystalline P and Ca/P molar ratio in CaP, can achieve quantitative analysis of ion clusters in CaP crystallization system. Such method is easy to be operated and has high accuracy. The CaP crystallization process can be divided into three stages: initial ion cluster formation and aggregation (0~20s), mid-term ion cluster formation (20~3000s), and later ion cluster aggregation (3000~7200s), of which the P recovery rates are 11.1%, 3.9%, and 28.5%, respectively, indicating the main P recovery of achieved by ion cluster aggregation. The introduction of crystal seeds into CaP crystallization system of wastewater can regulating the clustering and aggregation process of CaP ion clusters, therefore improve the P recovery performance.
		2024 Vol. 44 (11): 6194-6200 [Abstract] ( 101 ) [HTML 1KB] [ PDF 941KB] ( 513 )

	6201	Adsorption characteristics of polystyrene-based Ce-La bimetal oxides for phosphate
		LI Han, SHEN Meng-meng, LOU Ran, CHEN Jia-chao, CHEN Zhi-hui, ZHU Ya-xian, YANG Wen-lan
		Ce-La bimetal oxides (CLBOs) nanoparticles were immobilized within the pores of a polystyrene anion exchanger (PAE) to fabricate a polystyrene-based nanocomposite CLBOs@PAE for efficient phosphate removal from acidic wastewater. Experimental results indicated that CLBOs@PAE exhibited excellent stability at pH≥3, and acidic conditions favor its adsorption of phosphate. At a pH of 4 and an initial phosphate concentration of 30mg/L, the maximum phosphate adsorption capacity reached 56.71mg/L. The phosphate adsorption process of CLBOs@PAE followed pseudo-second-order kinetics, achieving adsorption equilibrium within 180minutes. Benefiting from the preferential adsorption of embedded CLBOs nanoparticles towards phosphate (involving hydroxyl ligand exchange and inner-sphere complexation), CLBOs@PAE showed significant phosphate adsorption selectivity in the presence of high concentrations of coexisting anions (SO₄^2-, HCO₃^-, NO₃^- and Cl^-). Fixed-bed adsorption experiments demonstrated that at an influent phosphate concentration of 5mg/L, CLBOs@PAE exhibited an effective treatment capacity of up to 5000BV before reaching the breakthrough point (0.5mg/L). Moreover, CLBOs@PAE displayed excellent desorption and regeneration properties, maintaining a relatively stable adsorption capacity over long-term cyclic use, highlighting its promising potential for phosphate removal in acidic wastewater treatment.
		2024 Vol. 44 (11): 6201-6209 [Abstract] ( 94 ) [HTML 1KB] [ PDF 1292KB] ( 532 )

	6210	The seepage regulation mechanism of passive convergence-permeable reactive barrier
		ZHENG Kai-xuan, TAO Shi-yang, DING Jie, CHEN Di, TAN Yi-qi, LEI Lei, CHEN Yan-zhi, WANG Wei, WEN Yong, PENG Xiang-qin, WANG Hong-tao
		Passive convergence-permeable reactive barrier (PC-PRB) is a novel and sustainable in-situ remediation technology for contaminated groundwater. To evaluate the hydraulic capture performance of PC-PRB and reveal its seepage regulation mechanism, we developed a PRB-Flow simulation software with high accuracy of particle tracing algorithm and strong numerical solution stability. Under the specified simulation conditions, the PC-PRB exhibited an approximately 47% increase in planar capture flow rate and a 90% increase in sectional capture flow rate compared to the continuous permeable reactive barrier (C-PRB). Sensitivity analysis showed that the water pipe length L_p, the horizontal range of the passive well TD_w and the passive well depth H_w were the key parameters affecting the hydraulic performance of PC-PRB. There was a significant positive correlation between L_p and the hydraulic capture performance of PC-PRB (P<0.01). Increasing TD_w and H_w can enhance the hydraulic capture capacity of PC-PRB, but the influence degree was not as significant as L_p. The drainage and depressurization effect of the water pipe makes the head drop in the passive well, which drives the surrounding groundwater to converge into the well, thus significantly improving the hydraulic capture performance of PC-PRB. PC-PRB can effectively solve the local breakthrough problem of C-PRB caused by uneven flow velocity.
		2024 Vol. 44 (11): 6210-6220 [Abstract] ( 108 ) [HTML 1KB] [ PDF 990KB] ( 539 )

Solid Waste

	6221	Impact of plastic circular package on the plastic pollution in typical regions
		LIU Xue-wei, LEI Ting-zhou, BAI Jing-jing, LOU Zi-yang, HAN Yi-shi, MA Wen-chao
		This study provides an overview of plastic use, waste, and environmental leakage to 2060. The role of plastic policy scenario implementation (curbing industry demand, enhancing recycling, and reducing the mismanagement rate) in mitigating plastic pollution is illuminated. The research found that if the plastic industry continued as it is, it would remain unsustainable. Environmental leakage of plastic would be expected to double by 2060 compared to 2022. Implementing plastic policies could limit the global growth trend in plastic use and waste (nearly 23% reduction), improve the recyclability of plastic (2060: recycling, +30%), and reduce the environmental leakage of plastic (2060: mismanagement, -15%). The policies consider several scenarios, all of which would contribute to the reduction of mismanaged waste, with a 64.09% reduction in plastic leaking into the environment project. Policy scenarios make the relative decoupling between the environmental leakage and the use of plastic, which conveys that the environmental leakage of plastic will no longer be directly affected by usage. Future policy construction can turn towards strengthening recycling and disposal structure management to achieve sustainable development.
		2024 Vol. 44 (11): 6221-6227 [Abstract] ( 121 ) [HTML 1KB] [ PDF 1612KB] ( 750 )

	6228	Degradation process of polylactic acid plastics in freshwater sediments
		FENG Qin-shuang, ZHANG Li-xue, TANG Bing-ran, HE Qiang, LI Hong
		In order to investigate the degradation process of commercial polylactic acid (PLA) plastics in freshwater sediments, a laboratory sediment system was established and the alternation in surface property, the attached biofilm and the microorganism communities on biodegradable plastic bag (PLAB), plastic straw (PLAS) and plastic cup (PLAC), with PLA as the main component, were identified. The results showed that the surface of plastics became rougher after 180days incubation in sediment, and PLAB with numerous protrusions, cracks and holes on the surface exhibited a mass loss (7.30%), showing the highest degree of degradation. Meanwhile, the infrared spectrum of PLAB changed significantly, with increased peak intensities of characteristic peaks such as C=O and C-O as well as a 13.65% increase in carbonyl index. The XPS spectra indicated that the O/C value of PLAB and PLAS were increased by 13.89% and 5.17%, respectively. The relative content of RO-C=O in the three plastics were reduced, indicating that all the studied plastics underwent degradation. At the end of the experiment, the surface of plastics was colonized by PLA degrading bacteria (Pseudomonas) and Desulfobacterota which may drive the degradation of PLA. PLAB had the strongest fluorescence intensity of mature biofilm, and its biofilm biomass in surface sediment was significantly higher than that of control (P<0.05). PLAB favored the formation of biofilm and the growth of the surrounding microbes, which may be attributed from its roughest surface. In addition, as components of PLAB, poly (butyleneadipate-co-terephthalate) (PBAT) displayed higher hydrolysis rate, which may be responsible for its most obvious degradation among the three plastics. Moreover, PLA plastics increased the microbial diversity in surface sediment and changed the relative abundance of dominant phyla, and may affect element cycles.
		2024 Vol. 44 (11): 6228-6240 [Abstract] ( 106 ) [HTML 1KB] [ PDF 4589KB] ( 560 )

	6241	Collaborative mineralization and simulation study of waste gypsum and CO₂ in citric acid industry
		HUANG Yan, ZHU Zi-han, ZHOU Zi-an, SUN Xiao-ting, DONG Li-ming, YU Su-ping
		To achieve efficient synergy in carbon capture and utilization of waste gypsum in the citric acid industry, this study was based on the CO₂ emission characteristics of citric acid production process, and conducted a study on the process conditions of using ammonium chloride leaching waste gypsum solution to absorb CO₂. Aspen Plus was also used to simulate the synergistic mineralization process. The results showed that approximately 20L of waste gas containing 80% CO₂ (V/V) was generated from 1L of citric acid fermentation broth. When the initial concentration of ammonium chloride was 2mol/L and the waste gypsum was leached for 100minutes, the Ca²⁺ concentration could reach 0.062mol/L. Based on the optimized absorption process conditions, mineralization of 33% CO₂ can be achieved and approximately 192g CaCO₃/kg anhydrous citric acid can be produced. The simulation results of the fully mixed reactor process using Aspen Plus showed that when the CO₂ inlet flow rate was controlled to be 0.6kmol/h and the appropriate ammonia and gypsum inlet flow rates were controlled, a mineralization rate of 96.4% for CO₂ and 100% for gypsum conversion can be achieved, and the synergistic mineralization effect was the best.
		2024 Vol. 44 (11): 6241-6249 [Abstract] ( 102 ) [HTML 1KB] [ PDF 1900KB] ( 617 )

	6250	Enhancement of high concentration anaerobic fermentation of cow dung and reduction of antibiotic resistance genes by Nano-Fe₃O₄
		XI Yan-hua, WANG Xin-zhi, LI Xu, WEI Shuai-qiang, SUN Li-bo, LYU Ya-tian, CHENG Hui-cai
		In order to improve the biogas production performance of high-concentration anaerobic fermentation of cow manure, the enhancement effect of different concentrations of nano iron trioxide (Nano-Fe₃O₄) on substrate hydrolysis and biogas production efficiency was tested, and the influence on microbial community structure and antibiotic resistance genes (ARGs) in the fermentation system were further explored. The results showed that adding 500mg/L of Nano-Fe₃O₄ can improve the hydrolysis degree of high concentration anaerobic fermentation substrates in cow manure, enhance system stability, and increase biogas production by 12.36%. Compared with the control, the abundance of Firmicutes and Fibrobacters in the fermentation system significantly increased by 37.39% and 75.86%, respectively. At the genus level, especially the abundance of Clostridium and Ruminococcus was 3.50 times and 8.69 times higher than that before. Methanosarcina was dominant among methanogens,with an abundance of 2.55%, a significant increase of 27.50% over the control. In addition, the abundance of potential pathogenic bacteria Treponema and Acinetobacter was significantly decreased by 72.14% and 93.69%, respectively. The reduction rate of tetracyclines (tetA,tetG,tetH,tetJ) and aminoglycosides (aph(3), aph(6)) in ARGs was 100%; The average reduction rate of sulfonamide class (sul1, sul2) was 74.41%~96.55%. Research has shown that adding an appropriate amount of Nano-Fe₃O₄ had multiple promoting effects on stabilizing the fermentation system, improving microbial activity, increasing biogas production, and reducing antibiotic resistance genes, etc. The research results can provide relevant theoretical guidance and practical basis for the use of conductive exogenous regulatory additives such as Nano-Fe₃O₄ in livestock and poultry manure biogas projects.
		2024 Vol. 44 (11): 6250-6259 [Abstract] ( 104 ) [HTML 1KB] [ PDF 1777KB] ( 475 )

Soil Pollution Control

	6260	Effect of aging on co-transport of microplastics and cadmium in canal soils
		YANG Rong, ZHAO Fan, GUI Xiang-yang, CAO Feng-he, LI Bo-wen, CHEN Ming
		Packed column experiments and numerical simulations were conducted to investigate the effect of microplastics (MPs) aging on their co-transport with cadmium Cd(II) in canal soils. The aging of MPs facilitated their transport in soils. Compared with pristine (unaged) MPs, the transportability of aged MPs in soils increased by 28.3%~184%. This is likely because of the enhanced negative charges of MPs after aging, resulting in enhanced stability of MP suspensions and stronger repulsive energy barrier between aged MPs and soil particles. For the co-transport of MPs and Cd(II), compared with MPs-alone, the presence of Cd(II) inhibited the transport of MPs in soils, decreasing by 0.20~0.33 times. The aging effect of MPs further reinforced the inhibited transport of MPs by Cd(II), decreasing by 0.21~0.59times. In contract, MPs acted as carriers that enhance the transport of adsorbed Cd(II) in soils. Furthermore, the aged MPs exhibited greater enhancement effect on Cd(II) transport, increasing by 0.56~3.2 times, mainly due to the increased transport of aged MPs that can carry more adsorbed Cd(II). A two-site kinetic retention model was successfully employed to simulate the co-transport of MPs and Cd(II) in soils. The modeling results illustrate the effect of the aging on co-transport of MPs and Cd(II) and further indicate that the aged MPs increased the transport solute flux and potential risks of Cd(II) in soils.
		2024 Vol. 44 (11): 6260-6270 [Abstract] ( 113 ) [HTML 1KB] [ PDF 1965KB] ( 571 )

	6271	*Copper tolerance of a high copper-tolerant Cryptococcus laurentii* strain**
		LIU Wen-xin, WEN Qun-wei, ZHOU Xu, WU Qing-wen, XU Yang, QIN Chun-yan, CHEN Xue-lan, HUANG Ming-zhu
		We isolated a copper-resistant strain from a copper-contaminated area. The 18S and 26S rRNA sequencing showed it had the closest genetic relationship with Cryptococcus laurentii. It was found that the strain could grow normally in the medium with 15mmol/L Cu²⁺, and the maximum adsorption of copper was 29.36μmol/L/OD. In addition, the transcriptome analysis of the strains after copper stress showed that 126genes were up-regulated and 143genes were down-regulated; multiple genes related to amino acid metabolism, energy metabolism, and metal ion transport pathways were differentially expressed. At the same time, we found that copper stress blocked the glucose metabolism pathway, the expression of metabolism related genes decreased by 37% to 73%, which may be one of the important reasons why copper inhibited the growth of bacteria. The expression of heavy metal transport-related functional genes increased dramatically by 7 to 26 times in response to copper stress when induced by copper. The purpose of this study is to reveal the transcriptional response of the strain to copper stress and the metabolic pathways that may be involved in copper resistance, and to provide a basis for the application of microbial technology in copper pollution remediation.
		2024 Vol. 44 (11): 6271-6277 [Abstract] ( 122 ) [HTML 1KB] [ PDF 1285KB] ( 608 )

	6278	Influence of iron and manganese in the vadose zone of red beds on the nitrogen biotransformation
		LIU Ying, HAN Zhi-yong, FENG Shi-jie, ZHAO Zi-liang, CHANG Jia-li, ZHU Hao
		The red beds vadose zone acts as a natural barrier against groundwater nitrogen pollution, but the influence of iron and manganese on the biotransformation of nitrogen remain unclear. Therefore, this study investigates the effects of Fe(III) and Mn(II) on the functional enzymes of dominant nitrifying and denitrifying bacterial species, as well as nitrogen conversion, mediated by the red beds vadose zone. The results showed that Acinetobacter and Pseudomonas were the dominant strains with the highest efficiency in nitrification and denitrification processes, respectively, in the vadose zone of the red beds. The optimal efficiency of nitrification and denitrification was observed at Fe(III) and Mn(II) concentrations of 20 and 10mg/L, respectively. However, inhibition of these processes occurred at concentrations around 30mg/L, and significant inhibition was observed at 60mg/L. The addition of sterilized red beds soil in the SFe0 group increased the activities of nitrification enzymes AMO and HAO by 4.69%~107.5% compared to the Fe0 group without red beds soil, promoting the conversion of NH+ 4 to NH₂OH in the later stages. The activities of denitrification enzymes NAR, NIR, and NOS were increased by 9.16%~73.36%, facilitating the conversion of NO to N₂O in the early stages. In the SMn(0) group, AMO and HAO activities were increased by 22.23%~120.29%, significantly promoting the conversion of NH₂OH to NO₂^- and NO₃^- in the later stages. Overall, the activity of denitrifying enzymes NAR, NOR, and NOS was enhanced, promoting the conversion of NO₂^- to NO in the early stages. At optimal concentrations, the SFe20 group were increased in nitrification and denitrification rates of 58.91% and 121.17%, respectively, while the SMn10 group were increased by 42.17% and 55.68%. Under inhibitory concentrations, the SFe60 group showed an increase of 61.79% and 65.91% in nitrification and denitrification rates, respectively, while the SMn60 group increased by 30.26% and 80.03%. The red beds vadose zone effectively promotes nitrification and denitrification processes and alleviates the inhibitory effects of high concentrations of Fe(III) and Mn(II).
		2024 Vol. 44 (11): 6278-6290 [Abstract] ( 101 ) [HTML 1KB] [ PDF 1890KB] ( 458 )

	6291	Risks of heavy metal contamination in soils of coal mining community and traceability based on PMF-HHR model
		ZHANG Xiao-jing, ZHANG Sheng-wei, LU Jun-ping, XU Zhuo, XU Jia-xuan, LI Xiao-yang, ZHANG Xiao-duo
		To clarify the pollution sources and ecological health risks of heavy metals in soils influenced by coal mining activities, a typical coal mine in Yjinholuo Banner of Inner Mongolia was selected as the study area. A total of 180 surface soil samples were collected from the mining area between 2021 and 2023, and the concentrations of eight types of heavy metals were analyzed. The positive definite matrix factor decomposition model coupled with health risk assessment (PMF-HHR) was used to quantitatively evaluate the human health risks associated with heavy metals from different sources. The pollution of Cd and Hg in the study area is particularly serious, with Cd content in open-pit mines reaching 18 times the background levels of Inner Mongolia, the content of Hg in underground mines being 4.8 times higher, and higher levels of Cd, Cr and Ni in open pit mines than in shaft mines. The heavily polluted areas are mainly located in coal mining areas and along highways. The soil around the mine posed a moderate ecological hazard, with forestland, grassland and farmland showing high-risk levels. PMF source analysis identified five major pollution sources: combined industrial emissions and atmospheric deposition (18.0%), transportation (12.6%), agricultural activities and coal combustion (14.8%), mining (17.0%), and natural parent sources (37.6%). There was a notable cancer risk for both adults and children, with a higher risk observed in children. The main sources of cancer risk were industrial emissions and transportation, with oral ingestion being the dominant exposure pathway. The PMF-HHR model can effectively quantify the health risks from different sources.
		2024 Vol. 44 (11): 6291-6301 [Abstract] ( 116 ) [HTML 1KB] [ PDF 1753KB] ( 589 )

Environmental Ecology

	6302	The characteristics of dissolved CH₄ in the Langhe Bay of the Danjiangkou Reservoir in summer
		MENG Jiang-huai, XIAO Shang-bin, KANG Man-chun, LIU Jia, JI Dao-bin, LONG Liang-hong, ZHU Yi-fan, FU Chen-le, HAN Yan-xing
		This study focuses on the dissolved CH₄ concentration (C_CH4), CH₄ diffusive flux at the water-air interface (F_CH4) and the physicochemical properties of the water body in Danjiangkou Reservoir. Using high-resolution equipment (FaRAGE), a two-day monitoring campaign was conducted from August 20^th to 22^nd, 2023 in the Langhe Bay, including continuous monitoring at a certain site and vertical profile monitoring at multiple sites. The results showed that the surface C_CH4 and F_CH4 in the reservoir bay exhibited significant spatial variability, with mean values of (0.54±0.16) μmol/L and (89.35±27.23) μg/(m²·h), respectively, and F_CH4 was comparable to other water source reservoirs but generally lower than non-water-source reservoirs. Vertically, C_CH4 was stratified with low levels in the surface water and high levels in the bottom water. Temporally, the nocturnal surface C_CH4 and F_CH4 were higher than those during the day. The results of the structural equation model indicated that spatial variations of surface C_CH4 in the reservoir bay could be attributed to pH with an explanation degree of 39.17%. Vertically, water temperature and dissolved oxygen (DO) mainly drove C_CH4, explaining 56.14% and 35.25% of the variance of C_CH4, respectively, while 52.32% of variance of diurnal C_CH4 resulted dominantly from DO. Water quality in the reservoir bay was classified as the oligotrophic status based on the comprehensive trophic level index (TLI(Σ)), and TLI(Σ) of the surface water gradually decreased longitudinally from site LH00 to LH05, with an average of (47.36±8.28). Vertically, TLI(Σ) (the mean was less than 50) was lower in the middle layer than both at the surface and bottom layers of the water column. There was no significant positive correlation between C_CH4 and TLI(Σ) in the Danjiangkou Reservoir, which was different from the findings in other studies. The mesotrophic water in source reservoirs reduced the risk of algal blooms, and thereby maintained the water quality and low CH₄ emissions; however, evaluating CH₄ emissions using TLI(Σ) was not suitable for mesotrophic reservoirs.
		2024 Vol. 44 (11): 6302-6312 [Abstract] ( 141 ) [HTML 1KB] [ PDF 1593KB] ( 343 )

	6313	Variation in benthic community composition, beta diversity, and driving factors in Lake Ulansuhai
		DU Cai-li, CUI Jiang-long, LI Guo-wen, ZHAO Chen, ZHANG Lie-yu
		The study investigated the benthic community structure, β-diversity and its composition in Lake Ulansuhai, and the effects of environmental/spatial factors on benthic β-diversity were analyzed by the Mantel test. The results showed that the benthic community structure in Lake Ulansuhai had significant seasonal differences, and the variance analysis also showed that there were differences in the biomass and diversity index for zoobenthos. The β-diversity of the benthic community in the Lake Ulansuhai was maintained at a high level and dominated by the turnover component, with the ratio of the turnover component reaching 80%. Mantel's test showed that the geographic distance did not have a significant effect on the β-diversity in the benthic community (P > 0.05). In contrast, environmental factors (mainly total nitrogen) in the water were positively correlated with benthic β-diversity and its turnover component, which indicated that environmental factors were the main drivers affecting the structure of benthic communities in Lake Ulansuhai.
		2024 Vol. 44 (11): 6313-6321 [Abstract] ( 106 ) [HTML 1KB] [ PDF 1784KB] ( 664 )

	6322	Effects of sediment capping on the nutrients release and recruitment of dormant cyanobacteria
		YANG Shi-you, TANG Bing-ran, LUO Jun-xiao, LIANG Jia-liang, HE Qiang, LI Hong
		To explore the effect of nutrients removal on the recruitment of the dormant cyanobacteria in sediments as well as the mechanism involved, we conducted a microcosm experiment, in which lanthanum modified bentonite and fly ash-based zeolite were used as nitrogen and phosphorus adsorption materials. Specifically, a control group, nitrogen controlling group (capping the surface sediment with fly ash based zeolite), phosphorus controlling group(capping with lanthanum modified bentonite), and a nitrogen and phosphorus double controlling group (capping with fly ash based zeolite mixed with lanthanum modified bentonite) were set up. The results showed that the concentration of phosphorus and ammonia nitrogen in the pore water of the sediments in control group reached 0.732 and 0.044mg/L after 120 days incubation, while were reduced by 97.81% and 65.91% in the phosphorus controlling group and nitrogen controlling group, respectively. This indicated that these treatments inhibited the release of sedimental phosphate or ammonia nitrogen. In contrast, nitrogen and phosphorus double controlling can achieve efficient reduction in both nitrogen and phosphorus release, as the total phosphorus and total nitrogen concentration in the overlying water showed 33.33% and 57.18% reduction in comparison with their initial value. In addition, Capping the sediment increased the relative abundance of denitrification microorganisms (e.g. Thiobacillus, Sulfuricurvum) and nitrate reduction reaction microorganisms (e.g. norank_f_Anaerolineaceae) in the surface sediment. At the end of the experiment, the concentration of chlorophyll a in the control group was 24.36µg/L, which was 16.13, 6.07 and 32.48 times of that in the nitrogen controlling group, phosphorus controlling group, and nitrogen and phosphorus double controlling group, respectively. The relative abundance of cyanophyta in the nitrogen, and nitrogen and phosphorus double controlling group were decreased by 12.24% and 10.16%, respectively. While the relative abundance of diatomata was higher than that in control group, with 2.34 and 2.33 times of the abundance recoded, respectively. This suggested that the phytoplankton diversity was substantially modified.
		2024 Vol. 44 (11): 6322-6331 [Abstract] ( 125 ) [HTML 1KB] [ PDF 2358KB] ( 624 )

	6332	*Inhibition effect of Microcystis aeruginosa* on autotrophic ammonia-oxidizing bacteria**
		FENG Qian-qian, XIA Ru-ting, MEI Hong, CHENG Kai
		Using Microcystis aeruginosa FACHB-1027 and autotrophic ammonia-oxidizing bacteria (AOB) Nitrosomonas eutropha CZ-4 and Nitrosomonas nitrosa WH-1 as the research material,this study explored the inhibitory effect of M. aeruginosa on AOB.Also,the molecular weight range of the inhibitory substances was determined by dialysis bag tests and the inhibitory substances composition was analyzed by GC-MS.The results showed that the inhibition efficiency of M. aeruginosa on the ammonia oxidation activities of the two AOBs were 90.7% and 89.4%,respectively,indicating that M. aeruginosa can significantly inhibit the ammonia oxidation activity of AOB in a non-ammonium nitrogen competitive manner.After the M. aeruginosa cultures were treated with a dialysis bag with a molecular weight cut-off of 200 Da,the permeate inhibited the ammonia oxidation activity of AOB by 86.9%. The half inhibitory concentration (IC50) of 5,5-2 methyloxazolidine-2,4-dione in the permeate to the ammonia oxidation activity of AOB was 0.4‰~0.8‰,indicating that the M. aeruginosa can secrete small molecular to inhibit the ammonia oxidation activity of the AOB.
		2024 Vol. 44 (11): 6332-6340 [Abstract] ( 91 ) [HTML 1KB] [ PDF 1105KB] ( 558 )

	6341	Distribution characteristics and transport patterns of microplastics in rivers and estuaries of China: a review
		SHEN Xia, LI De-hong, CAI Huan-jie, LI Xiao-long, CAO Li-wei, GAO Wei-zheng
		This study analyzed the “sources” and “sinks” of microplastics in rivers and estuaries, compared current microplastic pollution levels in these environments, and revealed the spatial and temporal distribution of microplastics. Moreover, it summarized the main factors affecting the transport of microplastics and examined the influence of hydrodynamic characteristics on this transport. The findings indicated that the dominant shape of microplastics in rivers and estuaries is primarily fibrous, with sizes mostly less than 1mm. Due to geographical location and seasonal differences, the flow patterns and pollution sources in different study areas vary, leading to distinct distribution characteristics of microplastics. The primary factors influencing microplastic transport in rivers were flow velocity and direction, which affected the settling and suspension behaviors of microplastics. In estuaries, wind and tides played a decisive role in the transport of microplastics. Future research should consider the transport and distribution of microplastics under the coupling effects of hydrodynamic characteristics and multiple influencing factors.
		2024 Vol. 44 (11): 6341-6353 [Abstract] ( 114 ) [HTML 1KB] [ PDF 577KB] ( 777 )

	6354	Assessment of ecosystem health of river based on microbe index of biotic integrity (M-IBI) —A case study of Zhangcun River in Qingdao
		WANG Shu-wen, LIN Jia-feng, SONG Zhao-lu, LI Xian-guo, ZHANG Da-hai
		To assess the contribution of fungal community bioindicators to river ecosystem evaluations, this study established a microbial integrity index (M-IBI) framework using high-throughput sequencing data of sediment samples collected from Zhangcun River during the wet season (September 2020) and dry season (March 2022). Core evaluation indicators, covering various metric types, were identified through distribution range, discriminatory ability, and correlation analysis. The results indicate that the key indicators for the wet season include the relative abundance of Agaricomycetes, the combined relative abundance of Ascomycota and Basidiomycota, the relative abundance of species negatively correlated with chemical oxygen demand (COD), and the relative abundance of animal pathogens. In contrast, the core indicators for dry season comprise the relative abundance of Hypocreales, the relative abundance of Tremellales, the ratio of Ascomycota to Basidiomycota, and the relative abundance of strains negatively correlated with conductivity and pH. Based on these findings, a fungal community-based M-IBI was calculated, which effectively differentiate the reference and impaired sites, and shows a significant correlation with water quality. The M-IBI based on fungal communities is a reliable and promising method for assessing river ecological conditions.
		2024 Vol. 44 (11): 6354-6363 [Abstract] ( 125 ) [HTML 1KB] [ PDF 1144KB] ( 631 )

	6364	Derivation of seawater quality criteria for n-propylbenzene and isopropylbenzene based on species sensitivity distribution
		LI Yu-mei, XIA Yu-fan, MENG Fan-ping
		At present, there is a lack of seawater quality standards for n-propylbenzene (n-PBZ) and isopropylbenzene (i-PBZ) both domestically and internationally, which is not conducive to pollution control and ecological risk assessment of such chemicals in the marine environment. In this study, the acute toxicity tests of n-PBZ and i-PBZ on four marine animals (Neomysis awatschensis, Artemia sp., Ruditapes Philippenarum, and Lateolabrax maculatus) were carried out, and then combined the obtained toxicity values with the reported toxicity values for marine microalgae in literature to construct the species sensitivity distribution (SSD) curves. By doing so, their hazardous concentration for 5% of marine species ((HC₅) were calculated, and the corresponding short-term seawater quality criteria (SSQC) was derived. The half lethal concentrations (LC₅₀) of n-PBZ and i-PBZ for marine animals ranged from 0.38to 83.89mg/L and 1.30to 119.11mg/L, respectively, and the N. awatschensis was most sensitive to both propylbenzenes. The HC₅ values of n-PBZ and i-PBZ were 0.48 and 1.71mg/L, respectively, and the corresponding SSQC values were 0.16 and 0.57mg/L, respectively. According to the risk quotient (RQ) calculation, totally the ecological risk of propylbenzenes was relatively low in the investigated sea areas. However, in the seawater near oil exploitation regions, amedium ecological risk (RQ>0.1) was caused by relatively high concentrations of propylbenzenes. In addition, the marine ecological risk would reach a very high level in sea areas where propylbenzene leakage occured, and effective measures need to be taken to accelerate the elimination of pollution.
		2024 Vol. 44 (11): 6364-6372 [Abstract] ( 108 ) [HTML 1KB] [ PDF 1203KB] ( 630 )

	6373	Application of continuous binning model in the calculation of water environmental capacity for lakes
		LUO Jing, HU Wei-ping, PENG Zhao-liang, LIU Gang, LI Mao-bing, GUO Xi-ya, WANG Yan-ping
		Based on the continuous-binning uniform mixed water quality model, an approach for computing water environmental capacity for different functional regions of shallow lakes was established. The certainty and uncertainty of results were analyzed by statistical methods. Meteorological and hydrological data over multiple years was used to calculate water environmental capacity for each region of Lake Chaohu, and compatibility correction was made to the result of each area. More accurate results under different hydrological conditions and water quality targets of Lake Chaohu were obtained by calculating the value range and average value of water environmental capacity series, and analyzing the consistency among water environmental capacity, pollutant flux into the lake, the water quality target and water quality. The results suggest that the annual degradation coefficients of total nitrogen, total phosphorus, ammonia nitrogen and permanganate index of Chaohu Lake were 2.99, 1.94, 10.86, 0.36a^-1, respectively. The water environmental capacity of the lake varies significantly under different hydrological conditions and water quality targets. The water environmental capacity exhibits decreasing trend with the decrease of water storage and stricter water quality targets. The approach proposed in this study shows high efficiency in calculating annual water environmental capacity under different hydrological conditions and water quality targets for shallow lakes, and can be used for providing guidelines for pollutants control in lakes.
		2024 Vol. 44 (11): 6373-6386 [Abstract] ( 100 ) [HTML 1KB] [ PDF 2073KB] ( 570 )

	6387	The influence of storm runoff on water quality of canyon reservoir
		HUANG Kang-zhe, XUE Rui-kang, HOU Yi, JI Gang, HUANG Ting-lin, WEN Gang
		Sanhekou Reservoir was taken as the representative to conduct field monitoring of multiple storm runoffs in the flood season of 2022. The characteristics of runoff pollution, the law of runoff inflow and its influence on reservoir water quality under different rainfall characteristics were explored, and a high-quality water intake scheme was proposed. The results showed that the total phosphorus and total iron in rainfall runoff were mainly in the granular state, and their concentrations increased significantly with the increase of rainfall intensity, which could be increased to 19 and 37 times of the concentration in the base flow, respectively. The total nitrogen and permanganate index were mainly dissolved, and their concentrations were weakly correlated with rainfall intensity, which could only increase to 2.6 and 2.1 times of the concentration in the base flow, respectively. Runoff entered the reservoir area in the form of isopycnal undercurrent, and the inflow process usually presented thermocline undercurrent, which deteriorated the water quality of the middle and lower layers. Runoff could be effectively predicted by comprehensively considering the antecedent precipitation index and daily rainfall, and runoff was a key indicator to determine whether the main reservoir area was directly affected by storm runoff. The flood peak flow of 2022-10-03 was greater than 1300m³/s, and the subsurface flow directly entered the main reservoir area, which increased the total nitrogen, total phosphorus, total iron and permanganate index of the thermocline from 1.224,0.019,0.106,3.790mg/L to 1.511,0.079,0.828,4.320mg/L, respectively. The water quality of the thermocline exceeded the Class III standard of surface water for half a month. In the project, high turbidity and high pollution source water could be avoided by stratified water intake.
		2024 Vol. 44 (11): 6387-6396 [Abstract] ( 93 ) [HTML 1KB] [ PDF 1051KB] ( 561 )

	6397	Quantitative monitoring of oil spill thickness using multiscale continuous wavelet-based shore-based hyperspectral analysis
		DONG Yang, CUI Hou-xin, DENG Jia-chun, MA Jun-jie, QIN Hai-xiao
		Focusing on the monitoring of 0# diesel oil film thickness, the primary objective is to meticulously analyze the spectral curve characteristics of different thickness oil films. Secondly, to delve deeper into the intricate relationship between spectral data and oil film thickness, the Morlet multi-scale continuous wavelet transform (CWT) technique is introduced. This enables the precise identification of spectral bands that are highly sensitive to oil film thickness, effectively addressing the challenge posed by the high dimensionality and complexity of hyperspectral data. Consequently, this approach significantly enhances the accuracy of thickness regression predictions. At the same time, the CatBoost regression model, with its efficient computing performance, strong feature capture ability, and excellent generalization ability, efficiently integrates these sensitive features and constructs a precise regression prediction model of the oil film thickness, accelerating the real-time monitoring speed of oil spill events, thereby achieving the immediate capture of changes in the thickness of the oil film and ensuring the accuracy of the prediction results, providing a solid scientific basis and technical support for the rapid initiation of oil spill emergency responses and the formulation of precise prevention and control strategies. The results show that the multi-scale continuous wavelet transform technology plays a key role in this study. It can effectively extract the sensitive bands highly related to the thickness of the oil film from the massive hyperspectral data, thereby significantly improving the accuracy and efficiency of oil spill thickness monitoring. The CatBoost regression model can better capture the change category characteristic data of the oil film thickness, further enhancing the generalization ability and robustness of the model. The diesel oil film thickness prediction model established by the CatBoost regression model shows extremely high accuracy, with R²=0.90, RMSE=95.14μm,δ=30.126% on the validation set.
		2024 Vol. 44 (11): 6397-6407 [Abstract] ( 106 ) [HTML 1KB] [ PDF 1473KB] ( 590 )

	6408	Application of the mass spectrometry imaging technology in environmental field
		ZHANG Yu-lin, ZHOU Yang-hao, CHEN Zhong-li, CHEN Rui-huang, SHAO Ying
		Through literature collection, study and bibliometric analysis of Citespace literature, this paper summarizes the development history of mass spectrometry imaging (MSI) technology and its latest application status in the environmental field. Combined with the current research bottleneck in the environmental field, the development prospect of MSI is deeply discussed. MSI, as a new technology integrating high sensitivity mass spectrometry and high precision spatial resolution imaging, can directly collect and identify molecular information from the sample. In the field of environmental toxicology and monitoring, MSI, on one hand, can demonstrate the distribution, location and quantify the pollutants and their transformed products in environmental media or within biological tissues, cells and even sub-cells, and thus reveal the target of pollutant action. On the other hand, it can analyse the characteristics and mechanisms of pollutants' bioaccumulation, biotransformation and metabolic activation. In summary, the application of MSI in the environmental field has important scientific significance, providing a new perspective in the monitoring of water, air and soil pollution, particularly for in situ identification of pollutants and analysis of their toxic effects. Besides, it provides a scientific basis for the risk screening, assessment and control of pollutants.
		2024 Vol. 44 (11): 6408-6417 [Abstract] ( 116 ) [HTML 1KB] [ PDF 803KB] ( 768 )

Agriculture and Country Emerging Contaminants

	6418	The mechanism of carbon quantum dots to regulate the reduction of 2,2’-dinitrobiphenyl by Shewanella
		WANG He-fei, SHEN Ke, ZHANG Wen-kang, SONG Yao, REN Chong-fei, YANG Chen, GAO Yan-zheng
		Shewanella, which is widely presented in soil, can reductively transform a variety of pollutants through extracellular electron transport pathways. Carbon quantum dots (CQDs) were produced from biochar through oxidation by nitric acid, and the the effectiveness and mechanism of CQDs to regulate the reduction of 2,2’-dinitrobiphenyl by the model microorganism (S. oneidensis MR-1) were studied. The produced CQDs were spherical with a particle size of 1.5~4nm, and the surface was rich in oxygen-containing functional groups, which were active for electron transfer. Mtr pathway was the main electron transport pathway for the reduction of 2,2’-dinitrobiphenyl by S. oneidensis MR-1, and SirCD was also involved in the reduction. CQDs can promote the electron transport in the reduction of 2,2’-dinitrobiphenyl by S. oneidensis MR-1, decrease the toxic effect of the pollutants on bacteria, thus improving the reduction efficiency. Goethite prevented reduction of 2,2’-dinitrobiphenyl by S. oneidensis MR-1, which can be alleviated by CQDs. Humic acid and CQDs promoted the reduction of 2,2’-dinitrobiphenyl by S. oneidensis MR-1.
		2024 Vol. 44 (11): 6418-6425 [Abstract] ( 126 ) [HTML 1KB] [ PDF 2627KB] ( 437 )

	6426	Effects and mechanisms of herbicides on horizontal transfer of antibiotic resistance genes through plasmid-mediated conjugation
		SUN Feng-fei, WANG Xiu, MAO Yu-meng, LIU Ke, LIU Juan
		The spread of antibiotic resistance genes (ARGs) in farmland ecosystem is directly related to human health, and has attracted much attention in recent years. Herbicides are common chemical reagents widely used in farmland ecosystem, and until now, little information has been known about its effects and mechanisms on horizontal gene transfer (HGT) of ARGs between bacteria. In this study, with Escherichia coli DH5α(carrying RP4 plasmid with Tet^R, Amp^R, Kan^R) as the donor and E. coli HB101as the recipient, a series of diparental conjugation experiments were conducted to investigate the effects of butachlor, paracetamol and glufosinate on HGT of ARGs via plasmid-mediated conjugation. Furthermore, the mechanisms involved were also clarified from cell membrane permeability, intracellular ROS content, and the transcription levels of genes related to conjugation. The results showed that 100~800mg/L of butachlor and 40~160mg/L of paracetamol could promote the conjugation transfer of plasmid RP4. Under test concentrations, butachlor stimulated the intracellular production of ROS, while paraquat reduced the ROS level. Under the treatment of butachlor or paracetamol, the surface of the recipient bacterium appeared obvious shrinkage, and with the increase of concentration, the pore and even break appeared. Butachlor (400~800mg/L) and paraquat (40~80mg/L) could both increase cell membrane permeability, inhibit the korA transcription and promote the transcription of trbBp、trfAp and traA, thus promoting the conjugation transfer of RP4. Under test concentrations, there was only a little effect of glufosinate on RP4 conjugation, as well as cell membrane permeability, intracellular ROS content and transcription of conjugation-related regulatory genes. This study indicated that widespread use of herbicides in agricultural production could affect the HGT of ARGs via plasmid-mediated conjugation, and the application of reasonable types and concentrations of herbicides could reduce the ARG transmission in both soil environments and plants.
		2024 Vol. 44 (11): 6426-6434 [Abstract] ( 136 ) [HTML 1KB] [ PDF 3026KB] ( 581 )

	6435	Potential human accumulation difference of polyhalogenated carbazoles pollutants
		MA Jun-chao, QIN Chao, WANG Ze-ming, LI Ze-kai, GAO Yan-zheng
		To evaluate the potential human accumulation difference and mechanism of polyhalogenated carbazoles (PHCZs), this study chose human serum albumin (HSA) as a model protein and used spectroscopy and quantum chemical calculations to analyze the interaction effects between HSA and four typical PHCZs, i.e., 3-bromocarbazole (3BCZ), 2,7-dibromocarbazole (27BCZ), 3,6-dibromocarbazole (36BCZ), and 3,6-dichlorocarbazole (36CCZ). All four PHCZs could bind to site 2 of HSA, with the order of intermolecular binding strength as follows: 36BCZ (3.89×10⁵L/mol) > 36CCZ (3.41×10⁵L/mol) > 3BCZ (1.43×10⁵L/mol) > 27BCZ (2.95×10⁴L/mol). Due to the better stability of intermolecular binding and minimal damage to the HSA structure, different PHCZs may have a stronger potential for bioaccumulation in the human body. Quantum chemical calculations indicated that the size and distribution of the negative molecular surface electrostatic potential area of PHCZs played a decisive role in intermolecular binding. This study revealed the potential human accumulation difference and mechanism of common PHCZs, which is of great guiding significance for identifying the types of PHCZs that need to be monitored and controlled in the environment, as well as for the human health risk assessment of PHCZs.
		2024 Vol. 44 (11): 6435-6441 [Abstract] ( 111 ) [HTML 1KB] [ PDF 2363KB] ( 651 )

	6442	The elimination of phthalate acid esters in crops using endophytic bacteria
		XU Lin, ZHANG You-ai, ZHOU Xian, QIN Chao, GAO Yan-zheng
		As emerging organic pollutants, phthalate acid esters (PAEs) can accumulate in crops such as vegetables, fruits, grains through absorption and enter the human body via the food chain, posing great threats to human health. PAEs contamination in soil has attracted widespread attention. How to directly reduce PAEs in crops to ensure the safety of agricultural production in polluted areas has been a hot spot and big challenge in agro-environmental field. Endophytic bacteria are living in and symbiotic with crops. It is expected that effective elimination of PAEs in crops can be achieved by isolating and screening endophytic bacteria with PAEs degradation function from crops grown up in PAEs contaminated areas, and colonising them into contaminated crops. In this paper, we analyzed the PAEs contamination differences in various types of crops and their distribution characteristics in different tissues, sorted out the reported endophytic bacterial species with PAEs degradation functions, and compared the effects of the functional endophytic bacteria on PAEs elimination in crops under different colonization methods, so as to reveal the mechanisms, pathways and key factors of PAEs degradation. It was pointed out that the construction and efficacy of composite endophytic flora for degrading co-existing complexed PAEs and endophytic flora with synergistic functions of “pollutant reduction” and “carbon emissions” coupling are the research directions worth attention in the future.
		2024 Vol. 44 (11): 6442-6452 [Abstract] ( 103 ) [HTML 1KB] [ PDF 648KB] ( 418 )

	6453	Carbon sequestration and decontamination effects of char-based immobilized microorganisms in soils contaminated with emerging contaminants
		XU Yan-xing, CHENG Hao, HU Xiao-jie, TANG Lei, ZHOU Xian, GAO Yan-zheng
		Char-based materials can play a key role in soil carbon sequestration and emission reduction, and can also be used as immobilized carriers of functional microorganisms. However, at present, relevant studies merely focus on a single direction of decontamination or carbon sequestration, lacking a systematic understanding of the synergistic effects of char-based materials. To comprehensively understand the role of char-based materials in environmental control, this review systematically summarized the recent research progress on the char-based materials used for microorganism-immobilization including biochar, activated carbon, carbon nanotubes, and carbon-based nanomaterials. The efficiencies and mechanisms of carbon-based materials in soil carbon sequestration and emission reduction were elucidated, and the effects and mechanisms of char-based materials-immobilized microorganisms on emerging contaminant decontamination in soil were also clarified. This review also pointed out the future studies including synergistical effects on the carbon sequestration and decontamination of char-based immobilized microorganisms, efficiency improvement of char-based materials, innovation of microbial-consortium immobilization methods, and industrial application of immobilized technology, which will provide some insights for the application of char-based materials to synergistically achieve the goal of “carbon fixation and pollution elimination” in contaminated soils.
		2024 Vol. 44 (11): 6453-6463 [Abstract] ( 112 ) [HTML 1KB] [ PDF 440KB] ( 673 )

	6464	Research progress on pollution characteristics and biodegradation of substituted polycyclic aromatic hydrocarbons in soil
		WANG Meng-yao, WANG Jian, TANG Lei, CHEN Xu-wen, GAO Yan-zheng
		In this review, the sources and pollution conditions of SPAHs in soil were analyzed, and the different bacteria reported for SPAHs degradation and their degradation mechanism were reviewed. The Mycobacterium and Sphingobium are the main bacterium involved in NPAHs degradation. Some bacteria and fungi can degrade OPAHs, while the microorganisms for HPAHs degradation are mainly the bacteria. The effects and mechanisms of microbial remediation for SPAHs-contaminated soil were also reviewed. In the biodegradation processes, SPAHs are first transformed to intermediates, which are further degraded to phthalic acid or/and salicylic acid under enzymatic hydrolysis, and finally mineralized through the tricarboxylic acid cycle. It is suggested that the degradation of SPAHs based on synergistic flora and immobilized microbial agents and the microbial remediation for SPAHs-contaminated soil are the important research direction worthy of attention in the future.
		2024 Vol. 44 (11): 6464-6471 [Abstract] ( 127 ) [HTML 1KB] [ PDF 354KB] ( 486 )

Emerging Contaminants and Environmental Toxicology

	6472	Research progress on screening of emerging priority controlled contaminants
		GAO Ge, ZHANG Wen-qing, WEI Xin-ni, LIU Peng, ZHAO Long
		At present, China does not have the capability for comprehensive management of emerging contaminants. It is necessary to conduct an integrated assessment and ranking of emerging contaminants, selecting those with higher rankings for priority and focused control. This paper reviewed the progress in screening emerging priority controlled contaminants in China, as well as in major developed countries and organizations such as the United States and the European Union, systematically sorted out the evaluation indicators and screening methods used in domestic and international pollutant lists. We further analyzed the main problems existing in China's screening work, and combined with the advanced foreign experience to put forward four targeted proposals: strengthening fundamental research and monitoring capacity for emerging contaminants, determining evaluation indicators applicable to China, establishing a sound screening method system, and zoning in the development and issuance of pollutant lists, so as to provide a reference for the future management and control of emerging contaminants in China.
		2024 Vol. 44 (11): 6472-6483 [Abstract] ( 136 ) [HTML 1KB] [ PDF 789KB] ( 934 )

	6484	Combined effects of polypropylene nanoplastics and organophosphorus flame retardants on zebrafish development and neurotoxicity
		ZHOU Xin, WAN Ke-wei, NI An-yu, FANG Lu, BAO Jun-ting, CHEN Jia-yi, WANG Hui-li, QIAN Qiu-hui, WANG Ze-jun, YAN Jin
		Using zebrafish as a model organism, this study investigated the toxic effects and the relevant mechanisms for the exposure to 2-ethylhexyl diphenyl phosphate (EHDPP), as well as the co-exposure to it with polypropylene nanoplastics (PP-NPs). The results indicated that the acute toxicity LC50value of EHDPP for zebrafish at 120hours post-fertilization (hpf) was 2240μg/L. Acute exposure to 250 and 500μg/L EHDPP resulted in developmental delays and deformities in zebrafish, inhibited their swimming activity and reduced the sensitivity to environmental stimuli. At the molecular level, EHDPP concentrations of 50, 125, and 250μg/L significantly decreased the activities of superoxide dismutase (SOD) and catalase (CAT) compared to the control group, leading to excessive accumulation of reactive oxygen species (ROS) and increased malondialdehyde (MDA) levels, which in turn induced inflammation and accelerated cell apoptosis. Although PP-NPs showed limited toxicity to zebrafish, the co-exposure to 100μg/L PP-NPs and EHDPP reduced the LC₅₀ value to 494.6μg/L, significantly enhancing the toxicity of EHDPP and lowering the threshold for its adverse effects, resulting in noticeable developmental and neurotoxic effects at lower concentrations. This study highlights the synergistic toxic effects that can arise from the coexistence of nanoplastics and organic pollutants, providing important insights into the risks associated with microplastics and organic contaminants in real environmental scenarios.
		2024 Vol. 44 (11): 6484-6494 [Abstract] ( 120 ) [HTML 1KB] [ PDF 3112KB] ( 1070 )

	6495	Toxic effects of class II biodegradable plastics on Microcystis aeruginosa
		XU Cheng-long, WU Pei, CHEN Bo, YE Tian-ran, LIAN Jian-jun
		In this study, polylactic acid (PLA), polybutylene glycol terephthalate (PBAT) in biodegradable plastics (BMPs) and polyethylene (PE) in conventional microplastics (CMPs) were selected as test chemicals, and Microcystis aeruginosa was used as the test organism. By testing indicators such as algal cell density, chlorophyll a (Chl-a), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), total intracellular soluble protein (TP) and reactive oxygen species (ROS), the effects of different dosages (50, 100, 150 and 200mg/L) and particle size (150, 250 and 500 μm) of PLA, PBAT and PE on the growth, oxidative stress and cell damage of Microcystis aeruginosa were investigated. The results showed that the growth and oxidative stress indexes of algal cells exhibited significant changes with exposure time under the single action of PLA/PBAT/PE. After 96h of exposure, compared with other treatment groups, the inhibition rate of PLA at a dosage of 100mg/L on Microcystis aeruginosa was the highest (16.31%), while the inhibition rate of PE at a particle size of 150 μm was the highest (15.97%). The exposure of PLA and PE significantly increased the contents of ROS, SOD, CAT and MDA in Microcystis aeruginosa, and their acute toxicity differences may be related to the roughness of the microplastic surfaces. PLA, as an aliphatic polyester, was more prone to hydrolysis in aquatic environments than PBAT, and the release potential of secondary microplastic fragments made it more severely acute toxic to algae.
		2024 Vol. 44 (11): 6495-6503 [Abstract] ( 101 ) [HTML 1KB] [ PDF 2333KB] ( 589 )

Carbon Emission Control

	6504	The impact of temperature on the total factor energy efficiency: empirical evidence from a global analysis
		ZHANG Hong-liang, WU Jie, ZHAO Lin-xuan, WU Jian
		This study employs a stochastic frontier analysis to measure the total factor energy efficiency at the national level across the globe, utilizes a two-way fixed effects model to evaluate the influence of temperature, a critical environmental factor, on the total factor energy efficiency, and projects the impact of future global warming on energy efficiency in different countries. The study finds an inverted U-shaped relationship between temperature and the total factor energy efficiency among nations, which is influenced by income levels. Energy efficiency in poorer countries is more affected by temperature compared to wealthier nations. Specifically, an additional day with an average temperature above 30℃ annually is associated with an average reduction of 0.161in total factor energy efficiency, while an additional day with an average temperature below 0℃ leads to an average decline of 0.176. Prediction results indicate that global warming by the end of the 21st century will lead to a decline in world average energy efficiency, with countries near the equator experiencing more severe impacts. Under the SSP2-4.5 and SSP5-8.5 warming scenarios, the temperature increase induced by climate change will reduce the world's average energy efficiency by 0.76% and 2.76% compared to levels from 1995 to 2005.
		2024 Vol. 44 (11): 6504-6512 [Abstract] ( 109 ) [HTML 1KB] [ PDF 1694KB] ( 616 )

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