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  Current Issue
 
2024 Vol.44 Issue.12,Published 2024-12-20
Air Pollution Control
Water Pollution Control
Soil Pollution Control
Environmental Ecology
Carbon Emission Control
Emerging Contaminants
Environmental Toxicology and Environmental Health
Ozone Pollution Control
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2024 Vol. 44 (12): 0-0 [Abstract] ( 85 ) [HTML 1KB] [ PDF 248KB] ( 461 )
Ozone Pollution Control
6513 Research topic and trend analysis of ozone pollution in China based on bibliometric review
XIE Xiao-dong, HU Jian-lin, ZHANG Yuan-hang
To gain insights into the current research hotspots and trends in the field of ozone pollution in China, a systematic analysis of literature indexed in the SCI database between 2005 and 2022 was conducted based on the bibliometric method. The results showed that the number of publications in the field of ozone pollution in China has shown an increasing trend, especially after 2018. The research mainly focused on the spatiotemporal evolution, the formation mechanism and source contribution, the health and ecosystem effects, and the control strategy. The research findings have provided theoretical support for preventing and controlling ozone pollution in China. The future research trends identified include the health effects of ozone, the impacts of extreme weather events on ozone, and the coordinated control of ozone and particulate matter.
2024 Vol. 44 (12): 6513-6521 [Abstract] ( 174 ) [HTML 1KB] [ PDF 2751KB] ( 719 )
6522 Review of ozone formation sensitivity in China
ZHONG Bo-wen, ZHOU Jun, WANG Yan, YUAN Bin, SHAO Min
This review synthesizes the current assessment methods and research advancements in ozone (O3) formation sensitivity in China. It examines the similarities and differences in the outcomes of various methods used to assess O3 formation sensitivity within the same region. The study reveals that O3 formation in urban areas of China is predominantly in the VOCs-limited regime, while in suburban areas, it is mostly in the NOx-limited regime or a transition regime. In recent years, the areas that are under the VOCs- limited regime have been diminishing, and those under the NOx-limited regime and transition regime have been gradually expanding. The study demonstrates that employing a combination of methods to diagnose O3 formation sensitivity in the same region can enhance the reliability of diagnostic outcomes. Finally, the review presents prospects for the development of emerging technologies and methodologies in China to more accurately determine O3 formation sensitivity.
2024 Vol. 44 (12): 6522-6537 [Abstract] ( 141 ) [HTML 1KB] [ PDF 627KB] ( 1406 )
6538 Influence of typhoon track in northwest Pacific on ozone pollution in autumn in Shantou City
ZHANG Yu-feng, YANG Jun-jun, CHEN Ting-ting, WAN Tao, CAI Huang, ZHANG Li-li, WANG Bo-guang, ZHANG Cheng-liang
In this study, the characteristics of typhoons in the Northwest Pacific Ocean and their effects on autumn ozone pollution in Shantou were analyzed using tropical cyclone data from 2015 to 2022, along with pollutant and meteorological data from the National control station in Shantou, and Global Data Assimilation System (GDAS) data obtained from the National Center for Environmental Prediction (NCEP). The results show that: A total of 234 typhoons occurred in the Northwest Pacific Ocean during this period. with the highest occurrence in summer(106), followed by autumn, and fewer in spring and winter. Through the application of the K-means clustering method, the typhoons were categorized into four types: W (westward landfall in Myanmar and Laos), L (northwest landfall in China), C (dissipation near the South China Sea and East China Sea), and ET (northwest and northeast turn after formation). Ozone concentration were found to be highest during C-type and ET-type typhoons, accompanied by rising temperatures, decreasing relative humidity, and increased solar radiation. Additionally, conditions of calm or light winds were conducive to ozone generation and accumulation. Conversely, ozone concentrations during L-type typhoons were significantly lower, marking these as clean air days. In such cases, meteorological conditions were characterized by rising temperatures, increased relative humidity, low solar radiation, and strong winds, facilitating ozone dispersion and dilution. The peak in ozone concentration during typhoon-affected days occurred between 15:00 and 17:00, with regional ozone transport playing a significant role. Air mass analysis over 72 hours indicated that the primary sources of ozone were located in Shanwei, Huizhou, Zhejiang, and Fujian provinces, with the air mass predominantly arriving from the northeast. Analysis of typical typhoon cases revealed that, compared to non-typhoon periods, photochemical ozone formation was more favourable during typhoon-affected periods due to higher temperatures, lower relative humidity, and stronger solar radiation. The regional transport effect of pollution during Typhoon "Meimei" is significant, and the ozone concentration will show a phenomenon of "peak lag". China has produced a pollution transmission channel from Anhui to Jiangxi and east Guangdong. The results of process analysis showed that the main ozone source contribution during typhoon period was chemical process (41.2%), followed by horizontal transmission (30.3%) and vertical transmission (28.4%).
2024 Vol. 44 (12): 6538-6548 [Abstract] ( 134 ) [HTML 1KB] [ PDF 3149KB] ( 507 )
6549 Characteristics of ozone variations during summer heat waves in typical cities in the Yangtze River Delta Region from 2014 to 2020
DING Jia-hao, XIE Xiao-dong, GONG Kang-jia, XUE Liu-cheng, HU Jian-lin
Three cities in the Yangtze River Delta (YRD), Shanghai, Nanjing and Hangzhou, were selected as typical representative cities to analyze the characteristics of ozone (O3) variations during the summer heat waves from 2014 to 2020 based on observations and WRF-CMAQ model. The results showed that the intensity of summer heat waves in the three cities showed an increasing, then decreasing, then increasing trend, with 2016 and 2017 being the years of super heat waves and 2014 and 2018 being the years of weak heat waves. The hourly O3 concentrations during the heat waves showed a “single peak, single valley” pattern, peaking at 13:00 or 14:00 and reaching valley values at 6:00. Interannual variations of the average daily maximum O3 concentrations, the average daytime and nighttime O3 concentrations and Maximum Daily 8-Hour Average O3 (MDA8O3) during the heat waves were similar in each city, with a significant decreasing trend in Shanghai, an increasing and then decreasing trend in Nanjing, and a decreasing trend in Hangzhou in general, and O3 concentrations during the heat waves were characterized by significant phase changes with temperature in each city. The WRF-CMAQ model could well simulate MDA8O3 during the heat waves in the three cities. Model results showed that the variations in meteorological conditions and precursor emissions have different effects on the changes in MDA8O3 during the heat waves in each city. Variations in meteorological conditions dominated the decrease in MDA8O3 during the heat waves in Shanghai, while variations in MDA8O3 in Nanjing were mainly influenced by variations in emissions, and variations in MDA8O3 in Hangzhou were influenced by the combined effects of meteorology and emissions. Meanwhile, persistent high temperature was not the only meteorological factor affecting O3 concentration, mean sea level pressure and wind speed also had a significant effect on MDA8O3 during the heat waves.
2024 Vol. 44 (12): 6549-6558 [Abstract] ( 132 ) [HTML 1KB] [ PDF 1769KB] ( 769 )
6559 Emission reduction measures for typical PM2.5 and O3 co-pollution event based on the adjoint model
LIU Zhe, AN Xing-qin, WANG Chao, LI Jiang-tao
To investigate PM2.5 and O3 co-pollution and its effective control measures, the "source-concentration" sensitivity analysis of a typical co-pollution event in Beijing from April 19 to 25, 2019 was conducted by GRAPES-CUACE adjoint model in this paper. The contribution of local and surrounding precursor emissions to the peak concentrations of 24h average PM2.5(24-hr PM2.5) and MDA8O3 in Beijing was quantitatively assessed, and corresponding emission reduction experiments were conducted using the adjoint model. The results of the adjoint sensitivity analysis indicated that the peak concentrations of 24-hr PM2.5 and MDA8O3 in Beijing were jointly influenced by the precursor emissions from both local and surrounding areas. The peak 24-hr PM2.5 concentrations were mainly contributed by primary PM2.5 (PPM2.5) emission sources within the preceding 48h, with the largest contribution from Hebei (49.7%), followed by Shandong (24.4%) and Beijing (20.1%). The formation of O3 was controlled by VOCs. The primary contribution periods were within the first 30h for NOx and the first 38h for VOCs. Hebei made the largest contributions, with NOx and VOCs contributing 27.0% and 23.8%, respectively, followed by Beijing (20.9% and 4.9%). The results of the emission reduction experiments for co-pollution event showed that when the peak 24-hr PM2.5 concentrations in Beijing met the standard, the reduction percentages of NOx, VOCs and PPM2.5 were similar, with the reduction percentages for each province as follows: Hebei (55.8%, 59.1%, and 61.3%), Beijing (60.0%, 47.4%, and 60.4%), Shandong (44.0%, 51.2%, and 61.3%), Tianjin (42.7%, 42.7%, and 42.7%), and Shanxi (44.0%, 40.9%, and 42.7%). The peak MDA8O3 concentrations initially increased and then decreased during the iterative process, and more NOx and VOCs needed to be reduced when reaching the standard. The emission reduction percentages for local and surrounding areas were as follows: Hebei (67.8% and 67.1%), Beijing (66.0% and 56.3%), Shandong (57.3% and 59.5%), Tianjin (50.9% and 52.4%), and Shanxi (55.4% and 46.0%).
2024 Vol. 44 (12): 6559-6568 [Abstract] ( 105 ) [HTML 1KB] [ PDF 3626KB] ( 494 )
6569 Coordinated control of PM2.5 and O3 compound pollution in Jincheng City based on the WRF-CMAQ model
LI Chen, ZHANG Zhi-juan, CHEN Xi, YE Cui-ping
This study used the WRF-CMAQ model to simulate and conduct source apportionment for a case of compound pollution in Jinzhong City. By designing 49 different scenarios of VOCs and NOx emission reductions and combining them with EKMA curves to evaluate the scientific reduction ratios of their precursors. The results revealed that industrial and traffic sources are the main contributors to VOCs and NOx in Jincheng City. O3 pollution is mainly influenced by NOx levels, whereas PM2.5 pollution is primarily controlled by VOCs. Considering non-extreme reduction scenarios, for O3 pollution control alone, the optimal VOCs/NOx reduction ratio is 1:2; for PM2.5 pollution control alone, the optimal reduction ratio is 2:1. When considering the coordinated control of both PM2.5 and O3 pollution, the best precursor reduction ratio of VOCs to NOx is 2:1.
2024 Vol. 44 (12): 6569-6577 [Abstract] ( 113 ) [HTML 1KB] [ PDF 1258KB] ( 528 )
6578 Vertical distribution characteristics of O3 under diverse polluted weather based on unmanned aerial vehicle observations
GUO Wei, ZHU Ling-yun, LI Yan-yu, CHEN Ling, YAN Shi-ming, LI Yi-ge
In order to understand the vertical distribution and evolution characteristics of near-surface O3 under diverse polluted weather, 33 in-situ observation experiments were conducted by the unmanned aerial vehicle (UAV) and airborne environmental meteorological equipment in Datong (clean days), Taiyuan (polluted days), and Linfen (polluted days to clean days) of Shanxi Province from August to September 2022, and the daily O3, Total Volatile Organic Compounds (TVOCs), Nitrogen Dioxide (NO2) and vertical distribution of temperature and humidity under 500m of the near-surface at 06:00, 10:00, 15:00, and 19:00 were obtained. The results show that the O3 concentration mainly increased with height, but decreased (Taiyuan and Linfen) or kept uniform distribution (Datong). The mass burden of NO2 and TVOCs both decrease with height. The daily change of vertical distribution of O3 in Datong was vertical increasing-uniformly distributed (or increasing and decreasing)-vertical increasing with height, while Taiyuan and Linfen were mainly vertical increasing-vertical decreasing-vertical increasing. Two types of vertical O3 daily variability caused by the regional transport at different heights were formed during the photochemical reaction period (10:00~15:00), namely, the simultaneous increase of O3 concentration in the upper air-grounding layer and the increase in the grounding layer-the basic stability in the upper air. The better the vertical diffusion conditions were, the more significant the vertical decrease of O3 would be during the pollution peak in the afternoon. Due to the influence of the nighttime inversion layer, the O3 stored in the upper layer of the boundary layer will continue to affect the vertical distribution of O3 and the ground level concentration on the second day. The near-surface VOCs control zones in each observation city gradually changed to common control zones and NOx control zones with the rise of altitude, and the higher the O3 concentration, the higher the altitude of the VOCs control during the observation period.
2024 Vol. 44 (12): 6578-6589 [Abstract] ( 119 ) [HTML 1KB] [ PDF 1824KB] ( 709 )
Air Pollution Control
6590 Aerosol optical properties and direct radiative forcing in Tianjin
LIU Jing-le, SHI Jing, JIANG Ming, CAI Zi-ying, YAO Qing, HAN Su-qin
Based on the analysis of solar radiometer observation data in Tianjin in 2021, we have obtained the variation characteristics of AOD (Aerosol Optical Depth), AE (Angstrom Exponent), FMF (Fine Mode Fraction), volume size distribution, complex refractive index, and direct radiative forcing. The research results indicated that affected by the sand-dust weather in spring and the hygroscopic growth and secondary conversion of aerosols in summer, the AOD values in spring and summer were 0.64 and 0.61 respectively, significantly higher than those in autumn and winter. The seasonal variation of AE in Tianjin ranged from 0.99 to 1.29. The volume spectrum distribution of aerosol particles exhibited a bimodal distribution characteristic. The peaks of the coarse and fine mode particle size spectrum reached of the highest in spring and summer respectively, with values of 0.07μm3/μm2 and 0.05 μm3/μm2 respectively. When AOD was greater than 0.4, the peak concentration of fine mode particles increaseed significantly and approaches the peak concentration of coarse mode particles. In summer, SSA reached 0.93, with the real part of the complex refractive index being 1.43 and the imaginary part being 0.07. In winter, the AAOD value was 0.10, and AAE was 1.15. Aerosol particles with strong extinction capability were concentrated in the range of AAE from 1.0 to 1.2 and SSA from 0.90 to 0.95. The main aerosol types in Tianjin were mixed absorbing particles, accounting for 40%, followed by fine-mode absorbing particles at 33%. The scattering and extinction capability of aerosols had a direct relationship with the increased in relative humidity and FMF. When the relative humidity was higher than 60%, aerosols were mostly types of III to VI. When the aerosol was type of VII, FMF was less than 0.4; when the aerosol was type of V, FMF ranges from 0.4 to 1.0; and when the aerosol was types of I to III, FMF was 0.8 to 1.0. The mean values of aerosol direct radiative forcing at the ground, top of the atmosphere, and in the atmosphere were -71.9W/m2, -14.9W/m2, and 57.1W/m2 respectively. The direct radiative forcing of aerosols was closely related to AOD and SSA. An increased in AOD by one unit resulted in changed in the direct radiative forcing of aerosols at the top of the atmosphere, ground, and in the atmosphereby -28.4W/m2, -99.4W/m2, and 70.9W/m2, respectively. The correlation coefficients with SSA were -0.85, 0.89, and -0.93respectively. As SSA increaseed, the absolute values of the direct radiative forcing efficiency at the ground and in the atmosphere decrease, while the direct radiative forcing efficiency at the top of the atmosphere gradually shifted from a heating effect to a cooling effect. Through the analysis of a haze-dust weather process in Tianjin from March 9th to 16th, 2021, it was found that during the haze episode, fine particle pollution mainly occurred in the form of urban-industrial aerosol types. The hygroscopic growth of aerosol particles led to the increased in the size of fine particles as pollutants accumulated, enhancing the scattering ability of aerosols and their cooling effect on the near-surface air, thus inhibiting the development of the boundary layer and causing a positive feedback mechanism between pollutants and the boundary layer.
2024 Vol. 44 (12): 6590-6599 [Abstract] ( 104 ) [HTML 1KB] [ PDF 1996KB] ( 587 )
6600 Characteristics and budget of nitrous acid at an urban site in winter of Shanghai, China
ZHOU Min, ZHOU Yang, WU Yu-hang, QIAO Li-ping, ZHU Shu-hui
Continuous measurements of HONO and related pollutants were conducted in the urban area of Shanghai from November 6, 2022, to January 2, 2023. By combining box model simulations, the concentrations, characteristics, and sources of winter HONO in Shanghai urban area were obtained. The results showed that the average concentration of HONO was (1.17±0.82)×10-9, with a concentration range of (0.078~5.32)×10-9. The average concentration of HONO in pollution days was significantly higher than that in clean days, showing an increase of approximately 67.2%. HONO exhibited diurnal variation, with higher concentrations at night and lower concentrations during the day, similar to the diurnal variation of NOx. Analysis of correlations between HONOcorr and various influencing factors indicated that the heterogeneous conversion of NO2 was the main source of HONO during nighttime, while both homogeneous and heterogeneous reactions (including photo-enhanced conversion) were dominate sources during daytime. Box model simulations suggested that daytime sources of HONO primarily were photo-enhanced conversion of NO2 on ground surfaces and homogeneous reactions involving OH and NO2. The average HONO formation rates in pollution days were 0.21 and 0.16×10-9/h, respectively. During nighttime, the dominate sources were NO2 conversion on ground surfaces and primary emissions. The increase in PM2.5 and its chemical species during nighttime lead to an increased contribution from NO2 photo-enhanced conversion on various surfaces.
2024 Vol. 44 (12): 6600-6607 [Abstract] ( 111 ) [HTML 1KB] [ PDF 1911KB] ( 542 )
6608 Long-term trends of HCHO columns in Shanxi Province based on satellite remote sensing
YANG Ai-qin, YU Xiao-hong, CHEN Ling, YAN Shi-ming, ZHU Ling-yun, GUO Wei, LI Ming-ming, LI Yan-yu, LI Ying, HE Jie-ying
The long-term trends of formaldehyde (HCHO) column in Shanxi Province from May to August over the period 2013~2022 were analyzed, using satellite measurements from Ozone Monitoring Instrument (OMI) and auxiliary data. The research examines the influence of biogenic volatile organic compounds (BVOCs) and anthropogenic volatile organic compounds (AVOCs) emissions on the observed variations in HCHO levels. Results indicate that the average HCHO column ranged from 4.1×1015 to 53.6×1015 molecules/cm2, with an annual mean of 14.3 × 1015 molecules/cm2. From 2013 to 2018, HCHO column exhibited an increasing trend, followed by a fluctuating decline from 2019 to 2022. Rural areas consistently showed higher HCHO concentrations compared to urban regions. After removing temperature effects, decreases in HCHO concentrations were observed mostly in urban areas with intense human activities, while increases were observed in rural villages with minimal anthropogenic influence. In temperature-sensitive regions, the rise in HCHO concentrations in northern Datong was attributed to increased BVOCs emissions from croplands. Similarly, in western Xinzhou to northern Lüliang, elevated HCHO concentrations were linked to higher BVOCs emissions from croplands, dense shrublands, mixed forests, and savannas. Conversely, central Jinzhong and southern Linfen to northern Yuncheng experienced reductions in HCHO concentrations due to simultaneous decreases in both AVOCs and BVOCs emissions, with reductions in AVOCs playing a particularly significant role.
2024 Vol. 44 (12): 6608-6616 [Abstract] ( 107 ) [HTML 1KB] [ PDF 4700KB] ( 385 )
6617 The pollution characteristics and sources of PM1 and PM2.5 during heavy pollution events in winter in Zhengzhou, China
ZHANG Hong-yu, ZHAI Shi-ting, YUAN Ming-hao, XU Yi-fei, WANG Shen-bo, ZHANG Rui-qin
This study used online observation instruments to analyze and compare the chemical composition of PM1 and PM2.5 during a heavy pollution event in Zhengzhou in 2021. Differences in the sources of PM1 and PM2.5, and the formation mechanisms of secondary inorganic aerosols, were investigated using a positive matrix factorization model, potential source contribution function, thermodynamic modeling, and chemical reaction rate equations. The results showed that the main components of both PM1and PM2.5were nitrate and organic matter, with higher concentrations in PM1 (35.1% and 23.6%) than in PM2.5 (26.3% and 18.2%). Compared to PM2.5, PM1 had larger contributions from secondary sources (37.7%), biomass burning (10.5%), industrial emissions (5.2%), and vehicle emissions (37.0%), while coal combustion (9.3%) and dust (0.4%) contributed less. Additionally, the impact of transport on PM1 was greater than on PM2.5. The dominant pathway for aqueous-phase sulfate formation in both PM1 and PM2.5 was H2O2 oxidation, with transition-metal ion catalysis playing a greater role in PM1 and O3 oxidation being more significant in PM2.5. Nitrate formation in PM1 appeared to be more influenced by gas-phase reactions, and high gas-particle partitioning of NH3 was likely at low aerosol water content in PM1.
2024 Vol. 44 (12): 6617-6627 [Abstract] ( 105 ) [HTML 1KB] [ PDF 2295KB] ( 568 )
6628 The performance and mechanism of Hg0 removal by Mn-Fe modified magnetic carbon sorbent
ZHANG Jing-dong, YANG Jiao-yu, JIE Cui, LI Hong-hu, PENG Xi-yan, AN Miao
In this study, a series of Mn-Fe modified carbon-based magnetic sorbents (MnxFey/C) were prepared by the sol-gel method and further evaluated for gaseous elemental mercury (Hg0) removal and anti-SO2 poisoning. SEM, TEM, BET, XRD, H2-TPR, Raman and XPS were employed to analyze the physicochemical structure of sorbents. According to the characterization results, the inherent reasons for the performance differences of MnxFey/C sorbents were clarified. The results indicated that Mn2Fe1/C achieved best Hg0 removal performance (99.99%) under 150℃ and 250μg/m3 Hg0. The addition of an appropriate amount of Fe could cause strong interaction between Mn and Fe. It led to an oxidation-reduction cycle of Mn3++Fe3+↔Mn4++Fe2+, thus promoting the generation of Mn4+ and weakening the chemical bond strength of Mn-O-Mn. Resultantly, the concentration of oxygen vacancies (Ov) and reactive oxygen species (Oα) was increased, which facilitated Hg0 removal over Mn2Fe1/C. In addition, Mn2Fe1/C showed good resistance to SO2. Its Hg0removal efficiency remained above 80% at a concentration of 2000×10-6 SO2. XPS showed that Fe could protect most of the Mn active sites from SO2 poisoning, thus inhibiting the formation and deposition of sulfate on the sorbent surface. Mn2Fe1/C could be separated from fly ash through magnetic separation. After four cycles of adsorption and regeneration, Mn2Fe1/C still exhibited a Hg0removal efficiency of 95.69%. It showed superior regeneration ability and might be a promising mercury sorbent for coal-fired flue gas.
2024 Vol. 44 (12): 6628-6640 [Abstract] ( 100 ) [HTML 1KB] [ PDF 3934KB] ( 545 )
6641 Study on the purification characteristics of high-temperature smoke utilizing magnetic basalt filter material in the iron and steel industry
ZHANG Li-an, DU Chuan-mei, XU Deng-ke, YANG Bing-wen, DIAO Yong-fa, SHEN Heng-gen
Given the physical property that the fugitive particles contained in the high-temperature smoke emitted by the iron and steel industry were easily magnetized, the concept and preparation method of new magnetic basalt fibers were proposed. A detailed analysis was conducted on the tensile properties, acid and alkali resistance, and the high-temperature stability of the fibers synthesized through the in-situ polymerization method. At the same time, the magnetic basalt filter material was formed utilizing the needle punching process, and its applicability was verified by testing its pore size distribution, mechanical strength, acid and alkali resistance, and high-temperature stability. The results showed that the in-situ polymerization method reduced the strength of the original basalt fibers by 4.6%. The magnetic basalt fibers exhibited acid but not alkali resistance, and their maximum operation temperature was 150°C. The magnetic basalt filter material exhibited a more concentrated pore size distribution with a smaller average pore size than the original basalt filter material. Additionly, the original and the magnetic basalt filter material were resistant to acids but not alkalies, and their maximum operation temperature was 250°C. When the filtration velocity was set as 5m/min, the dust concentration reached 50mg/m3, the filtration efficiency of the magnetic basalt filter material was up to 43.67% higher than that of the original basalt filter material. Furthermore, the pressure drop increase caused by the surface loading process of the filter material could be ignored.
2024 Vol. 44 (12): 6641-6650 [Abstract] ( 94 ) [HTML 1KB] [ PDF 1480KB] ( 534 )
Water Pollution Control
6651 Research on DN-PN/A coupled treatment of low ammonia nitrogen electroplating tail water
ZHANG Yu, LI Jia-yi, YANG Jun-feng, ZHOU Song-wei, WANG Xiao-jun
A pilot-scale continuous-flow denitrification partial nitrification-anaerobic ammonia oxidation (Anammox) multi-unit reactor was constructed to treat the electroplating tail wastewater. The pre-denitrification reactor demonstrated total inorganic nitrogen (TIN) and chemical oxygen demand (COD) removal efficiencies of (29.96±10.37)% and (73.33±9.6)%, respectively, with substantial removal of soluble organics to reduce pollutant loads in subsequent processes. The partial nitrification reactor confirmed that the zeolite packing method effectively achieved stable partial nitrification, yielding a nitrogen accumulation rate of (87.73±22.28)%. During long-term operation, it will be affected by scale, and its performance can be restored after scale removal. The Anammox reactor, as the primary nitrogen removal stage, maintained a TIN removal efficiency of (41.25 ± 14.46)% even during partial nitrification instability, relying on the cooperative effects of ammonia-oxidizing bacterium (AOB), denitrifying bacteria (DNB), and anammox bacteria (AnAOB). High-throughput sequencing identified Nitrosomonas (AOB), in the partial nitrification reactor, with a relative abundance of 5.45%, and Candidatus Anammoglobus (AnAOB), with a relative abundance of 25.91%. These findings provide both theoretical and practical foundations for applying the Anammox process in engineering contexts.
2024 Vol. 44 (12): 6651-6657 [Abstract] ( 107 ) [HTML 1KB] [ PDF 3573KB] ( 589 )
6658 Piezoelectric synergistic photocatalytic degradation of imidazolium ionic liquids
LAI Yue-hua, ZhAO Xiao-xiang, CHU Ling-long
Ionic liquids were efficiently degraded under piezoelectric synergistic photocatalytic conditions using a dual Z-type ternary catalyst, AgI/Ag3PO4/BaTiO3, which was able to degrade 1-hexyl-3methylimidazolium tetrafluoroborate up to 87.3% in 120 min with an apparent rate constant of 1.7 times that of the best binary catalyst. The results of quenching experiments further demonstrated the synergistic effect of piezoelectric on photocatalysis, ·O2- and h+ were main active substances for the degradation of 1-hexyl-3methylimidazolium tetrafluoroborate. AgI/Ag3PO4/BaTiO3 has good stability and reusability, and the degradation rate is still more than 80% after three cycles. The double Z-type structure of AgI/Ag3PO4/BaTiO3 can provide additional electron channels and improve the transfer rate of photogenerated carriers; in addition, the built-in electric field generated by piezoelectricity can improve the electron-hole separation efficiency, which provides the high efficiency in the degradation of the piezoelectricity is the most efficient way to degrade pollutants.
2024 Vol. 44 (12): 6658-6667 [Abstract] ( 98 ) [HTML 1KB] [ PDF 3495KB] ( 460 )
6668 Research progress of nitrate-dependent ferrous oxidation denitrification technology
XUE Jia-hui, LI Yan-yu, QIU Xu, XIAO Ju-qiang, LI Jie, SONG Guang-qing
Nitrate-dependent ferrous oxidation (NDFO) has emerged as a promising autotrophic denitrification technology, effectively addressing key limitations in wastewater treatment, particularly in systems with a low carbon-to-nitrogen (C/N) ratio. NDFO presents substantial economic and environmental advantages, making it an attractive solution for low C/N wastewater treatment. This review critically examines recent advancements in NDFO technology, emphasizing the functional characteristics of various NDFO microorganisms and elucidating the internal reaction mechanisms from both chemical and biological perspectives. We comprehensively analyze the influence of external factors, including temperature, pH, Fe/N ratio, organic carbon sources, and the presence of cations/anions, on the performance of NDFO. Additionally, we explore the role of Fe(III) minerals in the NDFO process and discuss strategies to mitigate cell crust formation. Finally, this paper identifies the existing challenges and limitations of NDFO technology and offers strategic directions for future research.
2024 Vol. 44 (12): 6668-6680 [Abstract] ( 116 ) [HTML 1KB] [ PDF 1031KB] ( 622 )
6681 Effect and mechanism of sulfamethoxazole/trimethoprim on nitrogen removal by solid-phase denitrification
ZHANG Yan-jie, WANG Huan, DONG Wei-yang, YAN Guo-kai, CHANG Yang, WANG Hai-yan, LING Yu, WEI You-fang, TIAN Zi-yang
It is unclear whether the antibiotics (i.e. sulfamethoxazole (SMX) and trimethoprim (TMP)) in the tail water of wastewater treatment plants would affect the nitrogen removal performance of plant carbon source supported solid-phase denitrification (SPD) technology and its mechanism. Three continuous-flow corncob-SPD (CC-SPD) reactors were established, the nitrogen removal performance of the reactors was compared, and the influence mechanism was analyzed by the metagenomic method. The results showed that: (1) The average effluent NO3--N concentrations of the three reactors were (4.09±0.38) mg/L(RS) (5.01±0.44) mg/L(RT) and (3.53±0.35) mg/L(RC), respectively. 50μg/L SMX/TMP had no significant effect on the nitrogen removal performance of the CC-SPD reactor; (2) SMX/TMP could significantly change the microbial community structure, but the dominant bacteria in the reactor were Proteobacteria, Bacteroidetes, and Actinobacteria. Metabolism was the main function of the microbial community, and microorganisms improved the relative abundances of functions about environmental information processing and cellular processes to adapt to SMX/TMP. 50μg/L SMX/TMP did not significantly affect the relative abundances of enzymes related to electron donor generation and denitrification genes.
2024 Vol. 44 (12): 6681-6690 [Abstract] ( 99 ) [HTML 1KB] [ PDF 1868KB] ( 470 )
6691 Influencing mechanism of H2O2 & Fe2+ pre-treatment on natural organic matter fouling behavior of membranes
MIAO Rui, TIAN Man-lin, YANG Yi-fan, MI Yue, WANG Lei, HUANG Dan-xi
Membrane fouling caused by natural organic matter (NOM) is a significant challenge that impedes the efficient and cost-effective operation of ultrafiltration (UF) systems. This study investigates the effectiveness of a trace-level pre-treatment using H2O2 and Fe2+ to mitigate membrane fouling induced by humic acid (HA), a model NOM. The results demonstrate that the addition of 100μmol/L Fe2+ and H2O2, followed by a 20-minute reaction, significantly reduces flux decline from 83% to 20% and enhances flux recovery from 26% to 100%, without the need for acidic conditions. The fouling reduction capability increases with both the duration of the reaction and the dosages of H2O2 and Fe2+, surpassing the individual effects of H2O2, Fe2+, or Fe3+ alone. This improvement is attributed to the generation of carboxyl groups in HA, which triggers a Fenton reaction. The combined oxidation and coagulation processes promote HA aggregation into larger flocs, diminishing HA adhesion to the membrane surface, and ultimately reducing the rate of fouling. The resulting fouling layer is less dense and more easily removable, leading to sustained membrane performance. These findings provide valuable insights into novel strategies for mitigating UF membrane fouling, offering both theoretical and practical contributions to membrane filtration technology.
2024 Vol. 44 (12): 6691-6697 [Abstract] ( 100 ) [HTML 1KB] [ PDF 839KB] ( 446 )
6698 The preparation and Fenton degradation performance of in-situ grown isolated iron 4A-Fe/PES composite membrane
LU Jing, ZHANG Han, YE Hui, SUN Jin-peng, XIN Qing-ping, ZHAO Li-zhi, LIN Li-gang, DING Xiao-li, ZHANG Yu-zhong, LI Hong
The integration of separation with Fenton oxidation aims to achieve efficient degradation of organic wastewater and continuous reuse of catalysts. In this study, 4A zeolite/PES mixed matrix membranes were prepared via non-solvent-induced phase separation and 4A-Fe/PES composite membranes were prepared by in situ growth of isolated iron species on the surface of 4A zeolite through an impregnation technique. Detailed characterization of membrane morphology and structure was conducted using SEM, FTIR, and XPS. The phenol degradation performance of this membrane was investigated under both static and dynamic conditions, with a comparative analysis of the H2O2 decomposition efficiency between 4A-Fe catalysts in powder and membrane forms. The results indicated that in situ growth of isolated iron species increased surface roughness on the zeolite. Under dynamic conditions, the degradation efficiency was significantly higher than in static conditions, reaching a 96.1% degradation rate within 1minute at pH 2, with 31.6mM H2O2 and an initial phenol concentration of 200mg/L. Catalytic kinetics revealed that, at pH 2, the degradation rate of the membrane form was 56times that of the powder form. Even After 5cycles, the membrane maintained a phenol degradation rate exceeding 90%.
2024 Vol. 44 (12): 6698-6707 [Abstract] ( 80 ) [HTML 1KB] [ PDF 1817KB] ( 626 )
6708 Construction of acid-resistant denitrifying mixed bacterial consortium and enhanced biological nitrogen removal
REN Xiao-lan, NIU Hao-ying, YUAN Jin, DUAN Yun, FAN Xiao-jun
To enhance the biological nitrogen removal efficiency of acidic nitrogen-containing wastewater and improve the adaptability of water treatment microorganisms to acidic water conditions, a "bottom-up" strategy for constructing a nitrogen removal bacterial consortium was adopted. Core strains were selected through statistical analysis and partial factorial experiments, and a group of denitrifying composite bacteria, S119-S136-L22, was rationally designed and constructed around these core strains. Under conditions of pH 4.0 and an initial nitrate nitrogen (NO3--N) concentration of 200mg/L, the nitrate removal rate reached 97.32% after 36hours. Through whole-genome sequencing combined with analysis of genes related to nitrogen metabolism and denitrification in each strain, it was speculated that strains S136 and L22 in the consortium are mainly responsible for reducing NO3--N to nitrite nitrogen (NO2--N), while S119 was responsible for reducing NO2--N to nitrogen gas (N2). Sequencing batch reactor (SBR) studies showed that the removal rates of NO3--N and total nitrogen (TN) in the experimental group were increased by 28.99% and 28.67%, respectively, compared to the control group. High-throughput sequencing and analysis of the microbial community interaction network in the system indicated that, compared to the control group, two additional functionally distinct bacterial genera, Cloacibacterium and Serratia, emerged in the experimental group, along with Enterobacter, Alcaligenes, and Klebsiella. The experimental group exhibited a more complex and diverse network of positive correlation pathways, not only showing synergistic interactions between the bacterial genera within the composite consortium but also collinearity between Serratia, Acinetobacter and Achromobacter, as well as between Cloacibacterium, Macellibacteroides and Pleomorphomonas. Analysis of the interaction network between effluent TN, NO3--N, and the microbial community revealed that Cloacibacterium primarily drives the removal of TN and NO3--N, while Pleomorphomonas, Microbacterium, and Propionicicella also play important roles in the removal process of TN and NO3--N.
2024 Vol. 44 (12): 6708-6720 [Abstract] ( 97 ) [HTML 1KB] [ PDF 4131KB] ( 442 )
6721 Correlation of nitrogen metabolism and heavy metal resistance genes in anammox sludges
QU Cai-yan, TANG Xi, CHENG Si-yuan, GUAN Hui-ze, TANG Chong-jian
To elucidate the interaction between nitrogen metabolism and heavy metal resistance in different sludge aggregates, we investigated gene abundance and correlations of nitrogen metabolism genes and heavy metal resistance genes. The gene abundance analysis revealed that the total abundance of nitrogen metabolism genes and heavy metal resistance genes in granules was higher than in flocs (by 24.5% and 5.5%, respectively) and biofilm (by 57.9% and 16.7%, respectively), indicating that granules exhibit the highest potential for nitrogen metabolism and heavy metal resistance. Further, the network analysis showed that the average degree of the granule network was 63.0% and 54.4% higher than in floc network and biofilm network, respectively, highlighting the strongest correlation between nitrogen metabolism genes and heavy metal resistance genes in granules. Therefore, the granule is the optimal sludge aggregate for anammox-based process in treating ammonia-rich wastewater containing heavy metals.
2024 Vol. 44 (12): 6721-6728 [Abstract] ( 106 ) [HTML 1KB] [ PDF 1463KB] ( 709 )
6729 Catalytic degradation of EDTA-Cd by EDTA-Cu in MXene/PMS process: Performance and mechanism
SONG Hao-ran, XU Yi-hang, CHEN Long-yu, ZHAO Qun, LI Chen, CAO Yan, ZHANG Lin-feng, HU Xue-wei, LIU Shu-gen, LI Ying-jie, LI Jie, TIAN Sen-lin
Without the addition of low-valent transition metals, MXene/PMS achieved efficient degradation of EDTA-Cd and recovery of Cd using copper ethylenediaminetetraacetate (EDTA-Cu). The removal efficiency of EDTA-Cd and total Cd reached 80% and 95% within 30minutes, respectively. Increasing the concentrations of MXene, PMS, and Cu2 significantly enhanced the removal of EDTA-Cd and total Cd. The primary reactive species in reaction process were identified as hydroxyl radical (HO·) and sulfate radical (SO4·-). Excellent performance was maintained within a pH range of 3.0 to 9.0, with good resistance to Cl-, HCO3-, HPO42-, and humic acid. Activation of PMS by MXene initiated the oxidative decomposition of EDTA-Cu and released free Cu ions. Then, MXene triggered the Cu(II)/Cu(I) cycle and furtherly enhanced PMS activation, and thereby achieved the efficient degradation of EDTA-Cu/Cd. Additionally, MXene exhibited excellent adsorption capacity for Cu and Cd ions, thus to achieve the recovery of heavy metals. This study utilized the transition metals inherent in heavy metal complexs to develop an efficient method that simultaneously achieves the oxidative decomplexation of heavy metal complexes and the recovery of heavy metals.
2024 Vol. 44 (12): 6729-6740 [Abstract] ( 92 ) [HTML 1KB] [ PDF 1454KB] ( 526 )
6741 Preparation of water-stabilized PEI@UIO-67-bpy composites and adsorption of Cr(VI)
HU Yu-lu, WANG Chi, WANG Tao, ZENG Qiao, LI Kai
UIO-67-bpy with good water stability was prepared by a solvothermal method, and polyethyleneimine (PEI), which contains a large number of amino functional groups, was introduced into UIO-67-bpy by a simple impregnation method to further enhance the stability and improve the adsorption performance and recycling ability for Cr(VI). The kinetics experiments showed that the adsorption reached the adsorption equilibrium at 90min and the removal rate was as high as 99%, and the adsorption of Cr(VI) by PEI@UIO-67-bpy was in accordance with the proposed two-stage kinetic model.The theoretical maximal adsorption capacity of Cr(VI) derived from the Langmuir isotherm model was 297.7mg/g.The cyclic regeneration experiments demonstrated that the removal efficiency of Cr(VI) was maintained at more than 95% after five cycles. The removal of Cr(VI) by PEI@UIO-67-bpy involves electrostatic interaction and reduction of Cr(VI). In conclusion, PEI@UIO-67-bpy is an excellent adsorbent with simple preparation, good stability and adsorption properties, and can be recycled.
2024 Vol. 44 (12): 6741-6752 [Abstract] ( 108 ) [HTML 1KB] [ PDF 7335KB] ( 454 )
6753 Effect of thermal treatment coupled with acid activation on phosphate adsorption by alum sludge
CHEN Ai-xia, PU Ma-xue-er, LYU Lu-xue, WEI Xiao, GAO Ya-jun, FAN Zhi-jie
Alum sludge (AIS) originating from water treatment plants possesses notable phosphate adsorption and chelating capabilities, due to its rich content of aluminum and iron oxides. However, the effectiveness of AIS in phosphate adsorption is often hampered by its complex composition and the presence of impurities. To overcome these obstacles, this study adopted a simple yet effective method that combines thermal treatment with acid activation. The results showed that after being subjected to thermal treatment at 600℃ for 1hour and then activated with 2.0mol/L hydrochloric acid at a solid-liquid ratio of 1:1, the AIS achieved a phosphate adsorption capacity of 18.3mg/g. This represented a 2.4-fold increase compared to the untreated AIS. Furthermore, the treated AIS demonstrated remarkable stability in tests involving the coexistence of anions and cations, as well as metal ion dissolution. The investigation into adsorption kinetics and thermodynamics revealed that the adsorption process was primarily driven by chemisorption. Complementary analyses using SEM, XRD, and BET further confirmed that the adsorption mechanism was dominated by ligand exchange. Additionally, electrostatic attraction, hydrogen bonding, and surface deposition also played pivotal roles in the adsorption process. These findings not only provide a promising perspective on alum sludge disposal and phosphorus pollution control but also embody a promising win-win strategy of "turning waste into treasure"
2024 Vol. 44 (12): 6753-6763 [Abstract] ( 89 ) [HTML 1KB] [ PDF 1781KB] ( 501 )
6764 Application of biogenic Cu/GO composite material in anodic activation of peroxymonosulfate degradation of Reactive Black 5
GUO Ya-ping, CHEN Xiao-qi, ZHANG Fan, WU Wen-ting, ZHANG Qian
This study innovatively employed the extracellular reduction activity of S.oneidensis MR-1 (MR-1) bacteria to prepare a Cu/graphene oxide composite material (MR1-Cu-GO) as an electrocatalyst (EC) and persulfate (PMS) synergistic catalyst. Characterization results indicated that the obtained MR1-Cu-GO exhibited a well-defined distribution of small-sized Cu species (with a diameter of approximately 5~10nm), with the predominant forms of Cu species being a mixture of CuCl2, CuO, and Cu2(OH)2CO3. Efficiency tests for RBK5 degradation reveal that the MR1-Cu-GO/PMS, MR1-Cu-GO/EC, and MR1-Cu-GO/EC/PMS systems all exhibit excellent degradation efficiency towards RBK5. Among them, the MR1-Cu-GO/EC/PMS system shows the highest degradation efficiency. Under optimal conditions with an applied current of 50A/m2 and an initial PMS concentration of 3mmol/L, utilizing the generation of active substances such as HO· and SO4·-, the system achieves a 100% RBK5 degradation rate within 30 minutes.
2024 Vol. 44 (12): 6764-6774 [Abstract] ( 102 ) [HTML 1KB] [ PDF 2284KB] ( 631 )
6775 Effect of cathode layer configuration on operational performance of a constructed wetland based on electrode-dependent ammonium oxidation
XU Zhan-yu, LU Xin-yi, TANG Chong, PAN Ling-yang, LI Long-xue, WEI Xiao-li, NI Cao-mei, LI Gang, WANG Zhen
A cathode layer was installed in a constructed wetland (CW) based on electrode-dependent ammonium oxidation, so as to achieve the occurrence of cathodic autotrophic denitrification in the layer, and it was conducted to explore the effect of cathode layer configuration on operational performance of the device, simultaneously, the microbial characteristics and the associated nitrogen transformation mechanisms in the system were also analyzed and elucidated. The results showed that, cathode layer configuration could significantly affect quantities of the critical functional microorganisms in the cathode layer, and then distinction in the intensity of cathodic autotrophic denitrification occurred in the region, leading to differences of nitrogen removal and electricity generation among the three devices. Regarding to the CW based on electrode-dependent ammonium oxidation, as bio-cathode was installed in its cathode layer filled with broken bricks, abundances and activities of the functional microbes (especially Geobacter, Thauera, Thiobacillus, Pseudomonas, and Hydrogenophaga) involved in cathodic NOx--N reduction increased since the improved cathode layer had lager specific surface area, higher total content of water-soluble salt, and Fe content. Correspondingly, multi-path coupled nitrogen removal system based on “electrode dependent ammonium oxidation-cathodic autotrophic denitrification” was established in the equipment owing to the largely enhancement of the cathodic autotrophic denitrification. Under the circumstances, ideal operational performance of the CW could be achieved, its COD, TP, TN and NH4+-N removal rates could respectively reached up to (88.79±2.58)%, (98.19±0.72)%, (91.34±3.58)%, and (96.78±2.90)% during the stable operation phase. Moreover, the output voltage and the maximum power density of the device was (787.99±89.43) mV and 214.41W/m3, respectively. This study should be conducive to research, development, and design of the new type of constructed wetland with enhancement of nitrogen removal.
2024 Vol. 44 (12): 6775-6786 [Abstract] ( 97 ) [HTML 1KB] [ PDF 2403KB] ( 382 )
6787 Process of research on Far-UVC technology in water treatment
FENG Ya-nan, TAN Yu-chen, LI Hao-xin, ZHANG Xi, ZHANG Tian-yang, LI Zi-fu, SUN Wen-jun, AO Xiu-wei
The main light sources used for emitting Far-UVC are introduced, such as krypton chloride excimer lamps. The mechanisms and recent research advancements of Far-UVC in microbial inactivation and organic micropollutant degradation are highlighted. In terms of microbial inactivation, Far-UVC could induce irreparable damage to pathogens by disrupting their nucleic acids, proteins, and lipids. For the control of micropollutant, on the one hand, the photon energy of Far-UVC exceeds the average bond dissociation energies of most chemical bonds. On the other hand, some of the organic micropollutants and oxidants have enhanced characteristic absorption under Far-UVC irradiation. This leads to the effective degradation of organic micropollutants by Far-UVC technology. Current studies have indicated that Far-UVC outperforms other UV techniques in some certain microorganism inactivation and organic micropollutant degradation. The effect of background water matrix components on the Far-UVC technique is then analysed. Finally, the prospects for future research directions on Far-UVC technology are dicussed, aiming to provide reference and guidance for research and application of this technology in the field of water treatment.
2024 Vol. 44 (12): 6787-6795 [Abstract] ( 118 ) [HTML 1KB] [ PDF 427KB] ( 615 )
6796 Preparation of GAC particle electrode and treatment of old landfill leachate
ZHANG Mao, LI Xiang, WANG Jun, YUAN Yan, HUANG Yong
The conventional fixed plate electrochemical system presents limitations such as electrode passivation, low space utilization, and reduced treatment efficiency. To address these issues, Mn-GAC particle electrodes were prepared using the impregnation method, and a three-dimensional electrolytic system was constructed to evaluate the comprehensive degradation effect on aged landfill leachate. The results demonstrated that particle electrodes with good performance could be successfully prepared under the conditions of 3hours of calcination time, a calcination temperature of 600℃, and an impregnation time of 8hours, as verified by pre-experiments and scanning electron microscopy (SEM). Under optimal conditions—initial pH value of 3, particle electrode dosage of 33.3g/L, current density of 160mA/cm2, and stirring speed of 700r/min—the removal rates of COD, TP, NH4+-N, and TN from the aged landfill leachate reached 81.56%, 99.62%, 62.82%, and 82.47%, respectively, with an energy consumption of only 0.125kWh/g. The analysis of the oxidation mechanism indicated that pollutant removal was primarily achieved through indirect oxidation, dominated by ·OH and active chlorine, accounting for 70% of the total contribution.
2024 Vol. 44 (12): 6796-6806 [Abstract] ( 93 ) [HTML 1KB] [ PDF 1998KB] ( 563 )
Soil Pollution Control
6807 Effects of exogenous nitrogen and phosphorus additions on DOM structural complexityin peatlands
ZHU Xiao-yan, LU Yu-han, WU Zhong, DONG Xiang-qian, WANG Qi-chen, LIU Zhong-hui, LU Yong-zheng
This study investigated the impact of exogenous N and P additions and their interactions on DOM, focusing on its concentrations and structural complexity by analyzing their spectroscopic characteristics in the long-term N, P additions platform in the boreal peatlands. The results indicated that exogenous N and P additions did not significantly alter DOM concentration, but a significant increase in DOM aromatization, from 58.5% to 82.9%, under high nitrogen (N(2)), low phosphorus (P(1)), and combined N-P treatments. Additionally, the endogenous input of DOM was amplified in treatments with high phosphorus (P(2)) and low nitrogen combined with high phosphorus (N(1)P(2)). Fluorescence analysis indicated that DOM primarily consisted of humic-like and protein-like substances. Individual N or P treatments were found to enhance the content of protein-like substances, whereas NP interactions predominantly increased the humic-like content. These results suggest that exogenous N and P additions increase the structural complexity of DOM by promoting plant growth and enhancing microbial activity in boreal peatlands.
2024 Vol. 44 (12): 6807-6816 [Abstract] ( 95 ) [HTML 1KB] [ PDF 1113KB] ( 514 )
6817 Characteristics of Zn flux in cultivated soil layer in karst and non-karst areas of Hengzhou, Guangxi
YANG Ye-yu, LI Cheng, YANG Zhong-fang, ZHANG Qi-zuan, WANG Lei, ZOU Sheng-zhang, WEI Hua-zhou, MO Jia-rong
A comparative study was conducted to analyze the import and export pathways, as well as the annual input and output flux density of Zn in cultivated soil, in both karst and non-karst areas of Hengzhou, Guangxi. The results showed that the content of Zn in soil in karst area was significantly higher than that in non-karst area under the influence of the parent material. The input of soil Zn in both karst and non-karst areas was significantly affected by human activities, with atmospheric deposition being the primary input pathway. The average annual input flux densities were 494.15 and 484.99g/(hm2·a) in karst and non-karst areas, respectively. The main output pathway was through harvesting, with the annual output flux densities being 490.63 and 580.12g/(hm2·a) in karst and non-karst areas, respectively. The annual output flux density in non-karst area was slightly higher due to the influence of Fe-Mn nodulation and irrigation water. Overall, the annual input flux showed Zn accumulation.
2024 Vol. 44 (12): 6817-6827 [Abstract] ( 104 ) [HTML 1KB] [ PDF 1419KB] ( 476 )
Environmental Ecology
6828 Contribution of ammonia-oxidizing microorganisms to nitrification potential and N2O production
WANG Da-ling, YANG Yu-hong, HE Hui, MI Tie-zhu, ZHEN Yu
This study utilized reverse transcription quantitative real-time PCR to investigate the spatial distribution of amoA gene expression levels among ammonia-oxidizing microorganisms in the surface sediments of the East China Sea during spring. Cultivation experiments were performed to assess the relative contributions of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) to the nitrification potential and N2O production in the surface sediments. The results revealed that the expression level of AOA amoA gene was significantly higher than that of AOB (AOA: 4.49×102~2.17×106copies/g;AOB: 6.60×101~7.65×105copies/g), with both showing a spatial distribution pattern of lower levels in nearshore areas (AOA: 8.92×105copies/g; AOB: 2.06×103copies/g) and higher in offshore areas (AOA: 1.05×106copies/g; AOB: 4.06×104copies/g). Nitrification potential was found to be higher in nearshore sediments than in offshore sediments, with the nitrification process gradually shifting from AOA dominance in nearshore areas to AOB dominance in offshore areas. In the N2O production process, the addition of NH4+ significantly enhanced N2O production, with AOB playing a more critical role than AOA in this process.
2024 Vol. 44 (12): 6828-6837 [Abstract] ( 101 ) [HTML 1KB] [ PDF 989KB] ( 466 )
6838 Study on the effect of lanthanum-modified bentonite and vallisneria spiralis combination on cobalt at the sediment-water interface
LI Min-juan, YAN Wen-ming, CHEN Xiang, LI Qi, HE Xiang-yu, WU Jing-wei, GUO Zi-rui
In order to explore the removal effects and mechanisms of dissolved cobalt(Co) in shallow lake sediments by the combination of vallisneria spiralis (V. spirals) and lanthanum-modified bentonite(LMB). The eutrophic sediment of Meiliang Bay in the Taihu Lake is the research object. Indoor simulation experiments (control group, LMB group, V. spiralis group, and LMB & V. spiralis group) were conducted based on High-resolution Peeper (HR-Peeper) to analyze the in-situ and vertical distribution characteristics of dissolved Co, Fe(II) and Mn in the interstitial water from 10 to -100mm of the sediment profile on days 15, 35 and 66after the addition of remediation materials. The results indicated that LMB and V. spiralis can significantly improve the redox environment of sediment profiles (P<0.05). Compared with the control group, the average concentration of dissolved Co decreased by 0.59%~38.18% in experimental groups. The release and migration of Co during combined use were mainly affected through adsorption of iron/manganese plaque on the root surface and complexed adsorption by LMB. In addition, LMB can promote the growth of V. spiralis. At 0~2cm sediment, the proportion of mobile Co(F1+F2+F3) was 54.91%~80.49%. The combination promoted the transformation of acid extractable state to reducible and oxidizable state. The release of Co at the SWI is mainly controlled by the oxidation-reduction of manganese.
2024 Vol. 44 (12): 6838-6845 [Abstract] ( 107 ) [HTML 1KB] [ PDF 1297KB] ( 531 )
6846 The effects of land use patterns on carbon and nitrogen cycling microbe in a river of the upper reaches of the Yellow River
YE Ling, HUANG Jing-jie, YIN Qiong-lin, XIE Lei, BAI Xue, PANG Qing-qing, ZHAO Ju, YANG Wei-gong, PENG Fu-quan, ZHU Xiang, YANG Fei, WANG Long-mian
In this study, the Qingshui River, a typical river in arid and semi-arid areas of the upper reaches of the Yellow River, was investigated. The metagenomic technology was used to reveal the impact of land use on carbon and nitrogen cycling microorganisms in the water bodies. The findings revealed the water quality was less polluted in forest reaches, the average concentrations of NH4+-N, NO3--N, TN, and COD were 0.19, 1.35, 1.66, and 21.92mg/L, respectively. Conversely, the NH4+-N(4.23mg/L) and COD(48.8mg/L) concentration elevated in the water body in urban and rural reaches, while NO3--N(21.62mg/L) and TN(31.59mg/L) contents increased in agricultural reaches. The relative abundance of the nitrification genes amoAB, nxrAB and the carbon cycling genes sucCD, IDH13, mdh, porAB, and gap2 was higher in forested reaches, while the relative abundance of the denitrification genes napAB, nirKS, and nosZ was higher in urban and rural area reaches, and in agricultural area reaches. The dominant microbial species of carbon and nitrogen functional were higher in forested reaches and urban and rural reaches with 20 species than in agricultural reaches with 15species. The microbial network showed that the number of correlation edges was less than 35 in urban and rural reaches and agricultural reaches, and more than 35 in forested reaches, thus the microbial network structures were notably more complex in forested reaches. In urban and rural reaches, Paracoccus and Sphingomonas were significantly negatively correlated with NH4+-N concentration, while Thalassiosira were significantly positively correlated with NO3--N concentration. In agricultural reaches, Leptothrix and Methylocystis were significantly negatively correlated with NH4+-N and COD contents; while Acidovorax, Flavobacterium, and Hydrogenophaga were significantly negatively correlated with NO3--N concentration.
2024 Vol. 44 (12): 6846-6857 [Abstract] ( 185 ) [HTML 1KB] [ PDF 2454KB] ( 564 )
6858 Characteristics of suspended particulate matter and its impacts on water quality in pre-dam system of Lake Changdang
ZHANG Song-he, DUAN Ru-fei, LUO Min, CHEN Hui, YANG Jian
In order to study the characteristics of suspended particulate matter (SPM) in the pre-dam and its potential impact on water quality, we investigated the spatial distribution of SPM and nutrients contents in overlying water in the upstream, midstream and downstream areas of the Dapu Harbor pre-dam system in Lake Changdang in low (December, 2022), medium (April, 2023) and high flow season (August, 2023). We also conducted an in-situ experiment to explore the interception mechanism in pre-dam system in high flow season. The results showed that about 46.42% of NH4+-N, 51.59% of TN and 36.83% TP were removed from overlying water through the pre-dam system, which play an import role on pollutes reduction. It should be noted that SPM sizes had significant effects on TOC (P=0.018) and TN concentration (P=0.011) and carbon and nitrogen contents in SPM increased with the increase of SMP sizes in surface layer of water column. The in-situ experiment revealed that TN and TP content were 2.33~5.25times and 4.53~5.72times higher in captured SPM from the surface and bottom layers of water column than in the free water body, respectively, and N and P concentrations in the water column were negatively correlated with the TN and TP concentrations in SPM, respectively. These data demonstrate that SPM as carrier can adsorb and transport pollutes, and SPM has a great influence on pollutes transformation through adsorption and precipitation. This study provided sound data that pre-dam system can improve water quality through SPM removal, especially for the treatment of high turbid water in inlet rivers of lake.
2024 Vol. 44 (12): 6858-6864 [Abstract] ( 113 ) [HTML 1KB] [ PDF 1189KB] ( 631 )
6865 Effects of artificial turbulence on physiology and biochemistry of Microcystis aeruginosa
LIU Huan, WANG Na, ZHANG Hai-han, LIU Tao, MA Ben, LIU Xiang, PAN Si-xuan
To explore the mechanism underlying the impact of water disturbance on algal growth and physiology, the growth metabolism and photosynthesis of Microcystis aeruginosa cells were examined under controlled artificial turbulence. The results demonstrated that the uptake of nitrogen and phosphorus by Microcystis aeruginosa cells could be enhanced by the moderate disturbance, consequently stimulating algal growth. Conversely, the growth of algae was inhibited by excessive disturbance. Furthermore, an increase in the photosynthetic activity and rate, as well as the production of adenosine triphosphate (ATP) in algal cells, was observed under moderate disturbance. At 14days of the trial, the effective quantum yield (Y(Ⅱ)) of photosystem II (PS II) in the 400r/min disturbance group was 3.77times higher than that before the disturbance. At 500r/min, enhanced antioxidant enzyme activity was exhibited by Microcystis aeruginosa cells to mitigate the oxidative damage caused by the accumulated reactive oxygen species (ROS), thus ensuring the maintenance of normal cellular processes. Three-dimensional fluorescence analysis results indicated that the production of intracellular organic matter (IOM) in algae could be facilitated by moderate disturbance. Consequently, in-situ algae inhibition could be achieved to a certain extent by turbulence disturbance in the water bodies affected by cyanobacterial blooms.
2024 Vol. 44 (12): 6865-6873 [Abstract] ( 108 ) [HTML 1KB] [ PDF 1518KB] ( 452 )
6874 Tracing dissolved inorganic nitrogen sources in plain river networks using stable isotopes: a case study of the Wen-Rui Tang River
LIU Yin-li, LIAO Zhong-lu, WANG Peng-wei, ZHAN Chen-can, TAN Xin-min, WANG Yu-hao, MA Hao-xiang, JI Xiao-liang
In this study, a representative plain river network in Zhejiang Province, namely Wen-Rui Tang River, was selected as the research area. The spatio-temporal variations and primary pollution sources of riverine dissolved inorganic nitrogen (DIN) were identified by combining multiple hydrochemical parameter with stable isotopes (δ15N/δ18O-NO3-, δ15N-NH4+, δ18O-H2O). On basis of these findings, a quantitative source apportionment method of DIN was developed by integrating nitrate and ammonia concentrations, their isotope compositions, and a SIAR model. Finally, the contributions of each pollution source to riverine DIN in Wen-Rui Tang River were calculated. Results revealed that the Wen-Rui Tang River exhibited severe DIN pollution with DIN concentrations ranging from 1.43mg/L to 12.88mg/L. Ammonia, nitrate and nitrite accounted for 63%, 35%, and 2% of DIN, respectively. Significant spatio-temporal variations of DIN content were observed in the Wen-Rui Tang River. Temporally, DIN concentrations followed the order: high flow season < usual flow season < low flow season. Spatially, DIN concentrations in mainstream were lower than those in tributaries and DIN concentrations in urban-rural segments were lower than those in urban segments. The predominant transformation process of DIN was nitrification rather than denitrification within the study area. The model results revealed that the contributions of manure and sewage, soil nitrogen, nitrogen fertilizer, and atmospheric deposition to DIN during the wet season were (71.29 ± 14.24)%, (18.96 ± 13.89)%, (6.78 ± 5.91)%, and (2.97 ± 2.28)%, respectively; during the usual flow season, these contributions accounted for (57.51 ± 15.53)%, (25.01 ± 16.45)%, (15.24 ± 8.19)%, and (2.25 ± 2.28)%, respectively; during the low flow season, they constituted (57.60 ± 16.27)%, (26.75 ± 17.58)%, (13.03 ± 7.95)% and (2.61 ± 2.55)%, respectively. Stronger uncertainties associated with soil nitrogen and manure and sewage contributions were found according to the uncertainty analysis.
2024 Vol. 44 (12): 6874-6885 [Abstract] ( 109 ) [HTML 1KB] [ PDF 1905KB] ( 545 )
Emerging Contaminants
6886 Review on removal of endocrine disrupting chemicals from water by advanced oxidation—Based on sulfate radicals
SHEN Zu-wu, LUO Hao-wei, QIN Qi-lu, AN Miao, YANG Jun, SONG Yong-wei
Due to the rapid development of modern industry, endocrine disrupting chemicals (EDCs) with high ecotoxicity are widely detected in the aquatic environment. In recent years, sulfate radicals-based advanced oxidation processes (SO4-·-AOPs) have been widely recognized for their high oxidative potential and effectiveness in the remediation of EDCs compared with other AOPs. In this paper, firstly, the activation mechanisms of different persulfate (PS) activation methods (e.g., transition metal activation, carbon material activation, thermal activation, UV activation, electrochemical activation, and ultrasonic activation) and their applications in the removal of EDCs are reviewed. The advantages and limitations of each activation method are pointed out, and some effective strategies to enhance their activation performance are summarized. Secondly, the application of sulfite as a novel precursor for the generation of SO4-· is presented, and the changes in toxicity of intermediates during the degradation of EDCs are emphasized. Finally, the research progress is summarized and prospected. In the future, it can be considered to expand the research of machine learning in predicting the reactivity, oxidation mechanism, generated transformation products and their toxicity of SO4-· to different EDCs, so as to further enhance the practical application potential of SO4-·-AOPs.
2024 Vol. 44 (12): 6886-6907 [Abstract] ( 103 ) [HTML 1KB] [ PDF 1564KB] ( 1230 )
6908 Distribution and risks of endocrine disruptors and personal care products in Lhasa River
GU Xiao-yun, GAMA Zhuo-ma, Ye Xin-tong, LU Xu-yang, LIU Chen
The Lhasa River, the largest tributary of the Yarlung Zangbo River, was selected to study the occurrence, distribution, sources and ecological risk of nine typical endocrine disruptors (EDCs) and personal care products (PCPs) in surface water of the main stream and tributaries during the dry season. The results showed that the detection rates of EDCs and PCPs in Lhasa River ranged from 53% to 100%, and the detection rates of bisphenol A, triclocarban, estriol and caffeine were higher than 90%. The average concentrations ranged from 2.28~19.45ng/L, with the highest concentrations of 36.8 and 27.4ng/Ldetected for caffeine and triclosan, respectively. The spatial distribution of pollutant concentrations increased gradually from upstream to downstream, with animal manure-sourced steroidal EDCs dominating in the middle and upper reaches and higher concentrations observed in the tributaries than the main stream. Two large reservoirs in the middle reaches had obviously reduced the concentrations of steroidal EDCs. Phenolic EDCs and PCPs were the major pollutants in the lower reaches, and the main stream from Lhasa City to Yarlung Zangbo River was the highly polluted area, with domestic sewage and industrial wastewater being the main source. Based on the risk entropy evaluation, the overall ecological risk in the Lhasa River showed a trend of downstream > midstream > upstream, with fish being more sensitive than algae and water fleas. Steroidal EDCs (17α-ethynylestradiol, 17β-estradiol, and estrone) posed a high risk to fish, octylphenol posed a medium risk to algae at relatively higher concentrations of the downstream, triclosan posed a low risk to aquatic life, and bisphenol A and triclocarban had no risk. This paper provided data support for the control of emerging contaminants in important rivers on the Qinghai-Tibet Plateau.
2024 Vol. 44 (12): 6908-6920 [Abstract] ( 103 ) [HTML 1KB] [ PDF 1997KB] ( 869 )
6921 Fe(VI)@PMS double oxidation system for degradation of methylparaben from wastewater
ZHAO Wen-bo, SU Bing-qin, ZHANG Xia-ling, SONG Xin-tong, LIN Jia-wei, WEI Yue-xing
Ferrate-activated peroxymonosulfate (Fe(VI)@PMS system) was used to degrade methylparaben (MeP) in wastewater. The degradation performance of MeP with different Fe(VI) dosage, PMS concentration, initial pH value, reaction temperature, initial MeP concentration and coexisting ions was investigated. Based on the Box-Behnken experimental design, a multifactorial experiment was conducted to fit the relationship between the degradation rate of MeP and Fe(VI) dosage, PMS concentration and initial pH to optimize the reaction conditions. The results showed that the MeP degradation rate was 99.03% under the conditions of Fe(VI) dosage of 0.92g/L, PMS concentration of 1.08mmol/L, initial pH of 6.83, and temperature of 25°C, which was similar to the model prediction of the maximum degradation rate of 99.17% for MeP, indicating that the response surface model has a better simulation and prediction ability. Cl-, NO3-, HCO3- and SO42- had no significant effect on the degradation of MeP. The free radical identification experiments proved that the degradation of MeP was accomplished by a combination of free radicals (·OH and SO4-·) and non-radical (1O2) oxidation, with 1O2 playing a major role. Liquid chromatography-mass spectrometry (LC-MS) analysis showed that the main pathways of MeP degradation included hydroxylation and decarboxylation reactions. ECOSAR toxicity analysis showed that the toxicity of MeP could be significantly reduced into non-toxic and harmless in Fe(VI)@PMS system.
2024 Vol. 44 (12): 6921-6934 [Abstract] ( 123 ) [HTML 1KB] [ PDF 2185KB] ( 900 )
6935 MOF-derived FeOOH-MnOx activated permonosulfate to degrade tetracycline hydrochloride
LU Zheng-yi, WANG Yong-quan, CAI Lan-yan, ZENG Jing, YE Rong-bin, HONG Jun-ming
Using the metal-organic framework (Mn-MOF-74) as a precursor, FeOOH-MnOx was prepared by introducing Fe2+ through calcination and used as an efficient catalyst for peroxymonosulfate (PMS) activation to degrade tetracycline hydrochloride (TCH). Characterizations using X-ray powder diffractometry (XRD) and scanning electron microscopy (SEM) confirmed the interwoven polyhedral structure of the catalyst. BET test showed that the specific surface area of FeOOH-MnOx was about 2.25 times greater than that of the precursor, which provided conditions for exposing more active sites. Under the optimal reaction conditions (10mg/L TCH, 0.1g/L catalyst, 1mmol/L PMS), the TCH removal rate of 92.5% in FeOOH-MnOx/PMS system was achieved. Additionally, superior stability and adaptability of the catalyst were demonstrated in the presence of inorganic ions and real water environments. The results of electron paramagnetic resonance (EPR) and quenching experiments indicated that O2·- was identified as the main reactive oxidative species in the degradation system.XPS results were shown to indicate the successful introduction of Fe2-, and the coexistence of Fe and Mn was found to promote the conversion of Mn(III)/Mn(II) and Fe(III)/Fe(II), which accelerated the electron transfer rate and further improved the catalytic performance.
2024 Vol. 44 (12): 6935-6948 [Abstract] ( 99 ) [HTML 1KB] [ PDF 4122KB] ( 1193 )
6949 Research progress of liquid phase microextraction in analysis of new pollutants in environmental water
ZHANG Qin-ming, HE Ying, WANG Lei, WANG Ruo-yao, ZHOU Chi, FAN Zhi-chao, YU Hai-bin, ZHENG Xiao-yan
This article reviews the research progress of liquid-phase microextraction (LPME) in the detection of new pollutants in environmental water bodies in recent years. Single-drop microextraction improves extraction efficiency by using droplet supports, dynamic or continuous flow extraction and so on. Hollow fiber liquid-phase microextraction improves performance of the method by optimizing the receptor phase, supporting liquid membranes, fiber type, etc with characteristics of high flux, stability, and strong selectivity. Dispersive liquid-liquid microextraction mainly focuses on selection, dispersion degree and separation method of extractants, has become a research hotspot due to its rapidity and efficiency advantages. In general, LPME is becoming well-established and shows broard application prospects in analysis of new pollutants in environmental water samples. It is recommended to prioritize the application of LPME technology in developing or revising environmental monitoring analysis method standards, especially in the analysis of ultra trace new pollutants and on-site emergency rapid detection.
2024 Vol. 44 (12): 6949-6961 [Abstract] ( 106 ) [HTML 1KB] [ PDF 708KB] ( 669 )
6962 Advances in the study of microplastic-microbial interactions in the aquatic environment
LI Xue, LUO Yu-hua, LI Hua, MIN Rui, ZHOU Tian-hong, ZHANG Hong-wei
Based on the existing researches and literatures, this paper comprehensively discusses the interaction between microplastics and microorganisms in the aquatic environment in recent years. It is found that microplastics can not only be used as mobile carriers of microorganisms, but also affect the structure and function of microbial communities, and microorganisms play an important role in the degradation of microplastics. In addition, this paper further explores the degradation mechanism of microplastics by microorganisms, and puts forward suggestions for future research and focus in this field, which provides theoretical references for further research on microplastic removal.
2024 Vol. 44 (12): 6962-6971 [Abstract] ( 111 ) [HTML 1KB] [ PDF 1317KB] ( 587 )
6972 The characterstics and risk assessment of microplastics pollution in cascade reservoirs of the Huangbai River
LIU Xiao-wei, LI Wei-ming, YAN Kang, XIAO Ming, LI Xuan, WANG Fang-wei, LI Ying-cheng, GAO Ya-kun, DING Shuang, FANG Zi-jie, LI Hong
This study focused on four cascade reservoirs on the East Branch of the Huangbai River, utilizing a stereo microscope and Fourier transform infrared spectrometer to identify the apparent characteristics and polymer components of microplastics, and to explore the pollution characteristics of microplastics in cascade reservoirs. The pollution risk index, pollution load index and potential ecological risk index were used to assess the ecological risk assessment of the microplastics pollution status in the study area. The results showed that notable variances in both the abundance distribution and apparent attributes of microplastics in surface water and sediment. The average abundance of microplastics in surface water and sediment was (2.30±0.63)n/L and (0.79±0.20)n/g. The abundance of microplastics in the surface water in the dam front area was higher than that in the middle area, which indicated that the dam front of the reservoir area may be a potential accumulation area for microplastics. The high abundance of microplastics in sediment concentrated in the upper reaches of the Xuanmiaoguan Reservoir, which was related to agricultural production and the pollution of domestic waste before the management of the Huangbai River, reflecting the long-term accumulation of microplastics in sediment. Polypropylene(PP) and polyethylene(PE) were the main polymer types, and black and blue were the main colors. The main shape of microplastics in surface water was fibers, while fragments were dominant in sediment. From the perspective of particle size distribution, microplastics with small particle size (0~300μm) were dominant, and the proportion of small-sized microplastics in sediment (82.38%) was much higher than that in surface water (42.96%). The results of the pollution risk index showed that the ecological risk level of surface water and sediment reached a medium level, while the pollution load index and the potential ecological risk index showed that the microplastics pollution status of each sampling point was slightly polluted, with an ecological risk level was I.
2024 Vol. 44 (12): 6972-6983 [Abstract] ( 129 ) [HTML 1KB] [ PDF 2797KB] ( 792 )
6984 Model-averaging species sensitivity distributions of perfluorooctanoic acid and its ecological risk assessment
GUAN Shuo, JIN Zhong-wu, DING Bing, GU Yan-sheng, LIU Xiao-guang
In this study, 30 aquatic species and their associated 53 single toxicity data were collected and screened. Based on different toxicity endpoint data, an Species Sensitivity Distribution (SSD) model for perfluorooctanoic acid (PFOA) was created. In order to reduce the uncertainty introduced by model selection, the model-averaging method was employed and applied to ecological risk assessment. According to the data on lethality, growth inhibition, reproductive toxicity, and biochemical toxicity, the derived Predicted No-Effect Concentration (PNEC) values were 2.09, 0.02, 0.006, and 0.024mg/L, respectively. It is noteworthy that under PFOA exposure, the reproductive endpoint of aquatic species exhibited the highest sensitivity. Therefore, the PNEC value based on the reproductive toxicity endpoint was selected as the Aquatic Life Criteria (ALC) for PFOA. Furthermore, PFOA exposure concentration data in surface water from the Yangtze River basin were collected, and the ecological risk of surface water in the Yangtze River basin was assessed using the Hazard Quotients (HQ) method. The research results indicate that among the 12sampling sites in the Yangtze River basin, the HQ values of all surface water samples range from 0.0004 to 0.04, suggesting that the ecological risk of PFOA in the Yangtze River basin is low. The findings of this study provide important references for aquatic bioprotection and mitigating the ecological risks of PFOA in China.
2024 Vol. 44 (12): 6984-6992 [Abstract] ( 122 ) [HTML 1KB] [ PDF 649KB] ( 460 )
Environmental Toxicology and Environmental Health
6993 The associations between NO2-related health burden and regional developments in China
ZOU Wei-wei, SHAO Yan-chuan, HU Li-tiao, GAO Ming, YANG Jian-xun, LIU Miao-miao, FANG Wen, BI Jun, MA Zong-wei
The related health burden was calculated by using the surface NO2 data from remote sensing at 0.1 degree during 2007~2020. The relationships between regional developments and health burden were explored using a random effect model. The NO2-related mortality usually occurred in the core economic areas of each province. The NO2 exposure was responsible for 301,873 deaths in 2020. The deaths increased by 23,790 during 2007~2013 and decreased by 80,478 during 2013~2020. The environmental Kuznets curve was found between gross domestic product (GDP) per capita and all-cause deaths. The economic growth will lead to an increase in NO2-related deaths in most cases. The increasing trend slows down for regions with higher GDP per capita. The urbanization follows a linear relationship with increased deaths. The results could provide insight into the sustainable developments for different regions in China.
2024 Vol. 44 (12): 6993-7000 [Abstract] ( 109 ) [HTML 1KB] [ PDF 1576KB] ( 463 )
7001 Prediction of heavy metal toxicity and ecological risk based on machine learning methods
LI Guo-feng, YU Jin-qiu, WANG Hong, CHI Hai-feng, LIN Shan-na, CAI Chao
This study focused on the toxicity of typical heavy metals in soil, including cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn), and summarized their effects on the model organisms, earthworms. A total of 113 datasets encompassing the median effective concentration (EC50) of heavy metals on earthworm reproduction, along with corresponding soil physicochemical properties, were compiled from the published literature. The correlation between various datasets was analyzed to reveal the influence of soil physicochemical factors on the biotoxicity of heavy metals. Five machine learning algorithms, including Random Forest (RF), Gradient Boosting Decision Tree (GBDT), Extreme Gradient Boosting (XGBoost), K-Nearest Neighbor (KNN), and Support Vector Regression (SVR), were employed to develop predictive models for biotoxicity of heavy metals based on soil characteristics, ultimately selecting the best-performing model for predicting potential ecological risk thresholds of heavy metals in Chinese soils. The results indicate significant variation in heavy metal toxicity across different soils, with the toxicity trend for earthworm reproduction ranking as follows: indicate significant variation in heavy metal toxicity across different soil types, with the toxicity ranking for earthworm reproduction as Cd>Cu>Pb≈Zn. The effects of soil physicochemical properties on heavy metal toxicity varies depending on the specific heavy metal. Specifically, soil pH emerged as a key factor influencing the toxicity of Pb and Cd, contributing 57.2% and 69.0% respectively, while cation exchange capacity and organic matter content were found to be the primary influencing factors for the bio-toxicity of Cu and Zn. The performance of the machine prediction models for biological toxicity of heavy metals based on soil physicochemical factors was compared and analyzed in terms of model fit and prediction accuracy. Among the predictive models, the XGBoost model performed well for predicting the bio-toxicity of Cd, Cu, and Zn, while the RF model demonstrated higher accuracy in predicting Pb bio-toxicity, achieving R2 values of 0.939 and 0.886 for training and testing sets, respectively. Furthermore, the potential ecological risk thresholds of heavy metals in soils across 34provinces in China were evaluated with the selected models, revealing significant regional differences in potential ecological risks. The findings provided a new strategy for accurate prediction and rational assessment of heavy metal ecological toxicity and potential ecological risk based on soil physicochemical properties.
2024 Vol. 44 (12): 7001-7010 [Abstract] ( 125 ) [HTML 1KB] [ PDF 1508KB] ( 656 )
7011 Antibacterial properties of metal polyphenol-based nanomaterials
HOU Jun, FAN Yue, YANG Zi-jun, WU Jun, YOU Guo-xiang, MIAO Ling-zhan
Using tannic acid and a variety of different metals as raw materials, metal-polyphenol based nano-antibacterial materials (MPNs) were prepared by one-step blending method, and applied to the antibacterial of gram-negative bacteria (E. coli) and gram-positive bacteria (S. aureus). The results showed that MPNs could cooperate photothermal antibacterial strategy with photodynamic antibacterial strategy under light to effectively resist bacteria without triggering bacterial resistance. The metal doping in the MPNs system was helpful to the antibacterial performance of MPNs under light to a certain extent. Taking the antibacterial effect as an indicator, a metal-polyphenol based semiconductor nano-antibacterial material (TA@Fe-TiO2 MPN) with the best antibacterial effect (more than 98%) was screened out, and its antibacterial mechanism was explored through DRS and XPS analysis. The results indicated that due to the oxygen vacancy introduced by TA@Fe on TiO2, TA@Fe-TiO2 MPN had a wide range of light response and enhanced electronic activity which enabled TA@Fe-TiO2 MPN to have enhanced and sustained reactive oxygen production (hydroxyl radical ·OH and singlet oxygen 1O2) and nearly 100% antibacterial properties under full-band illumination.
2024 Vol. 44 (12): 7011-7023 [Abstract] ( 120 ) [HTML 1KB] [ PDF 3829KB] ( 754 )
Carbon Emission Control
7024 Spatiotemporal trends and socio-economic impacts of anthropogenic carbon emissions in China based on OCO-2GHG satellite data
GAO Shun, OU Jin-pei, HUANG Xiao-lei, HUANG Ying-jian, XIE Ji-teng
The spatiotemporal dynamics of column-averaged CO2 dry air mole fractions, as captured by OCO-2 satellite XCO2 data, were meticulously examined across China from 2015 to 2021. This investigation harnessed the synergistic capabilities of spatiotemporal kriging methodologies and advanced XCO2 anomaly computation techniques. Additionally, the quantitative influence of socioeconomic determinants on XCO2 anomalies was elucidated through the application of the random forest algorithm. The findings revealed a discernible cyclical temporal pattern in XCO2 anomalies over the study period, with pronounced seasonal maxima during the winter months. Geographically, the anomalies exhibited a gradient distribution, with elevated concentrations in the eastern and southern regions, juxtaposed against lower levels in the western and northern territories. The spatial configuration of XCO2 anomalies derived from OCO-2 satellite observations was found to be largely congruent with anthropogenic emission inventories. Notably, at broader spatial scales and in regions characterized by higher emission intensities, XCO2 anomalies more effectively encapsulated the spatial distribution attributes of anthropogenic carbon emissions. At the provincial level, variables including GDP, local fiscal expenditure, population density, and vehicle ownership exhibited a significant positive correlation with XCO2 anomalies. Among these, GDP demonstrated the most pronounced association, with correlation and contribution ratios of 0.56 and 0.46, respectively. Furthermore, energy intensity, industrial composition, and energy consumption profiles were identified as consequential determinants contributing to XCO2 anomalies. These research outcomes substantiate the viability of leveraging satellite remote sensing to monitor spatiotemporal fluctuations in anthropogenic carbon emissions and to dissect their underlying drivers across China. This approach is anticipated to furnish critical insights for ecological conservation, environmental stewardship, and the formulation of informed strategies for carbon mitigation initiatives.
2024 Vol. 44 (12): 7024-7035 [Abstract] ( 107 ) [HTML 1KB] [ PDF 5495KB] ( 627 )
7036 Review of the greenhouse gas emission inversion approaches at city scale and future development trends
HU Cheng, ZHANG Jun-qing, LIU Hui-li, SHI Xue-jing, SUN Fan, XIAO Wei
Urban areas are hotspots for carbon dioxide (CO2) and methane (CH4), accounting for 40% to 50% of the global anthropogenic emissions. Therefore, the accurate quantification of their emissions directly impacts the formulation and implementation of climate change policies. The emission inventories are currently the main approach to account for emissions. However, numerous studies have shown that the uncertainty of greenhouse gas inventories at the urban scale is still larger than 50%. Hence, there is an urgent need to reduce the uncertainty in emission inventories. Inverse estimation methods, which is based on concentration observations and atmospheric transport model, have gradually been used for the estimation of urban-scale greenhouse gas emissions since 2010. However, there still exists many knowledge gaps for this approach. To meet the goal of "dual carbon" as announced in 2021, this paper reviews the research progress of urban-scale greenhouse gas emissions and discussed recent difficulties and challenges. It points out that the greenhouse gas concentration observation network is still lacking in China. And the use of medium-precision concentration observation networks and simultaneously developing of emission inventories and meteorological fields with spatial resolutions of 1km are important directions to accurately resolve the total emissions and spatiotemporal patterns of greenhouse gases at the urban scale in the future. By systematically summarizing the current research status, progress, and issues related to urban-scale greenhouse gas emissions in this paper, it is expected to provide methodological references and theoretical insights for the implementation of China's "dual carbon" strategy.
2024 Vol. 44 (12): 7036-7045 [Abstract] ( 115 ) [HTML 1KB] [ PDF 876KB] ( 549 )
7046 Spatial-temporal dynamics and influencing factors of CO2 and CH4 fluxes in a double-water-level regulated Hanfeng Lake in the Three Gorges Reservoir
JIAN Chen, YANG Yi, LIU Ting-ting, GONG Xiao-jie, WANG Xiao-feng
This study investigated the fluxes and concentrations of CO2 and CH4 in Hanfeng Lake, using the floating chamber method and headspace equilibrium method, to reveal spatio-temporal dynamics and driving factors of CO2 and CH4 emissions under varing water level fluctuations. The results showed that Hanfeng Lake was a weak CO2 emission source, with a flux range of -64.34 to 128.37mmol/(m2·d) and an average of (35.8±45.2)mmol/(m2·d), which was much lower than that of other waters in the Three Gorges Reservoir. Meanwhile, Hanfeng Lake was a strong CH4 emission source. Although the CH4 flux showed strong variations with ranges of 0.43~36.93mmol/(m2·d), its average value ((3.87±5.08)mmol/(m2·d)) was much higher than that of other regions in the Three Gorges Reservoir. The total emissions of CO2 and CH4 emitted to the atmosphere by Hanfeng Lake was 1415.48 and 133.54t, respectively, accounting for 26.86% of the total carbon storage of Hanfeng Lake, which indicated that Hanfeng Lake had an active carbon metabolism. From January to December, the CO2 emission flux in Hanfeng Lake showed a seasonal pattern of significant decrease and then rapid increase, and CH4 showed an almost opposite seasonal change. The seasonal dynamics were strongly disturbed by the double-water-level regulation. Higher CO2 and lower CH4 emission during the high water level period of the Three Gorges. During the Hanfeng water level period, CO2 emission was weaker, but CH4 emission was stronger. CO2 and CH4 emissions were stronger during the Three Gorges backwater period. Correlation analysis showed that CO2 emission flux was negatively correlated with Chl-a, algal density and pH. The change of primary production caused by algae blooms was the key factor to dominate the seasonal dynamics of CO2 emissions, and even led to the obvious CO2 source-sink transition in Hanfeng Lake. CH4 fluxes were positively correlated with TOC, DOC, TN, NO3--N and algal density, indicating that the seasonal dynamics of CH4 emission were dominated by nitrogen accumulation and algal metabolism. The CO2 emission flux in Hanfeng Lake showed a spatial characteristic of first decreasing and then increasing from upstream to downstream, which was opposite to the spatial dynamic of CH4 emission flux. This spatial characteristic was caused by the incoming rivers and water level fluctuation. In general, water level fluctuation obviously interfered with the correlation between water environment parameters and carbon emissions, resulting in different key indicators of CO2 and CH4 emission fluxes at different water levels.
2024 Vol. 44 (12): 7046-7062 [Abstract] ( 117 ) [HTML 1KB] [ PDF 3637KB] ( 947 )
7063 Carbon fairness in inter provincial crop production and its driving factors in China
TANG Li-chen, ZENG Xian-gang, CHEN Hui, LI Jie, CHEN Mi, ZHANG Zhong-yuan
On the basis of using the life cycle assessment method to calculate the carbon emissions of crop production in China and 31 provinces from 2006 to 2021, the carbon fairness coefficient of crop production was constructed from the perspective of carbon sink. The XGBoost model was used to identify the key driving factors of carbon fairness and their nonlinear response relationships. The results showed that during the inspection period, the overall carbon fairness of crop production in China tended to decrease, with the carbon fairness coefficient decreasing from 1.025 to 0.944. The regional differences in carbon fairness of crop production in China were significant, with the overall performance being "main grain production area>the production and sales balance area>main grain sales area". The overall degree of carbon fairness was decreasing from northwest to southeast, and there was a trend of weakening high-value aggregation and low-value aggregation. Except for factors such as farmland irrigation conditions, urban-rural income gap, and technological innovation level, other driving factors had complex nonlinear characteristics in their impact on carbon fairness. From the perspective of time effects, agricultural production structure was the most important factor affecting carbon fairness, and the importance of farmland irrigation conditions and grain yield per hectare factors always ranked high. From the perspective of regional effects, agricultural production structure factor ranked high, and there were certain differences in the importance of other driving factors.
2024 Vol. 44 (12): 7063-7078 [Abstract] ( 110 ) [HTML 1KB] [ PDF 1134KB] ( 616 )
7079 Impact of facility agriculture development on agricultural carbon emission efficiency
TONG Hao-tian, XIA En-jun, SUN Cong, HUANG Jie-ping
This study evaluates agricultural carbon emission efficiency (ACEE) and the current development status of facility agriculture, exploring its impact on agricultural carbon emission efficiency. Employing the super-efficiency SBM model, we measured ACEE across the agriculture, animal husbandry, and fisheries sectors, and analyzed the results using kernel density estimation. An entropy weight method was applied to construct the Facility Agriculture Development Index (FADI) for evaluation. An empirical study using the STIRPAT panel regression model examined the specific effects of facility agriculture on ACEE. The findings indicated that between 2010 and 2020, the national average ACEE improved by 49.13%, with significant increases in the eastern (56.72%) and western (52.96%) regions. Most provinces experienced growth in facility agriculture, averaging 2.88%, though economically developed regions lagged behind less developed ones. The STIRPAT model results highlighted a significant positive impact of facility agriculture development on ACEE, with contributing factors such as economic growth, population increase, and industrial structure upgrading. However, this positive effect was currently observed only in the eastern region, while the western, northeastern, and central regions still experienced negative effects. The research indicated that facility agriculture development positively influences national agricultural carbon emission efficiency, primarily driven by the eastern region, though disparities in ACEE and modernization levels persist across regions.
2024 Vol. 44 (12): 7079-7094 [Abstract] ( 127 ) [HTML 1KB] [ PDF 1783KB] ( 447 )
7095 Estimation model of vehicle carbon emission for provincial expressway networks.
YAN Sheng-yu, WANG Zhao-long, WU Jin, BAI Shu-ming, SUN Jian
The paper proposed a model for estimating the carbon emissions of provincial expressway network by toll collection data. In consideration of a theoretical fuel consumption model and the factors such as vehicle type differences, total mass, and vehicle operating conditions, it achieved precise calculation of carbon emissions at the section level. Based on toll collection data, the average speeds of section were calculated through data cleaning and aggregation, and TransCAD was used to achieve traffic allocation. By using PYTHON, the Dijkstra algorithm to determine the actual path matrix was implemented, combining these with the NEDC driving cycle to construct the vehicle driving cycle. It calculated fuel consumption and converted into carbon emissions by inferring specific fuel consumption through the MOVES database. Taking the Ningxia Hui Autonomous Region as a case study, we calculated the monthly carbon emissions of provincial highways and analyzed the distribution characteristics of carbon emissions. The feasibility of the model was verified through MOVES and COPERT simulations and comparison with various fuel consumption data released by the National Bureau of Statistics. The results show that in September 2019, the total carbon emissions of expressways in Ningxia Hui Autonomous Region were 210400 tons, with a passenger vehicle to truck distribution ratio of 1:3.92. Heavy trucks with 5axles or more accounted for 82.34% of the total carbon emissions of trucks. Passenger cars accounted for 83.18% of the total carbon emissions of passenger vehicles. Carbon emissions were mainly concentrated on the road network connecting provincial capital cities and surrounding prefecture level cities. Calculated emissions of the model were 15.86% above those of MOVES and 32.16% above COPERT’s, with a deviation of merely 4.29% from the national and local statistical department’s carbon emission converted by fuel consumption. The paper could reveal the carbon emissions of each vehicle type on provincial expressways, and the distribution characteristics of carbon emissions on each road section.
2024 Vol. 44 (12): 7095-7104 [Abstract] ( 131 ) [HTML 1KB] [ PDF 1197KB] ( 583 )
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