Soil is the main reservoir of microplastics, and the "plastic sphere" can be formed after microplastics enter the soil ecosystem,which is significantly different from the surrounding environment and might affect the soil microbial community structure. Exogenous microplastic particles were added to simulate different degrees of farmland soil microplastic pollution and explore the effects of microplastics on soil microbial communities. The results showed that microplastics pollution could greatly change the bacterial and fungal communities at the microbial genus level in soil. In rhizosphere and non-rhizosphere soils, the number of specific genera of fungal community in the high concentration group of microplastics treatment was significantly higher than that in the low concentration group (p<0.05). The changes of bacterial community and fungal community structure in rhizosphere and non-rhizosphere soils caused by microplastics pollution were significantly different. And the results of soil microbial community diversity and symbiotic network analysis showed that the addition of microplastics in the high concentration group significantly reduced soil microbial diversity, and the effect of microplastics on rhizosphere soil microorganisms was greater than that of non-rhizosphere soil. The results suggested that the response degree of soil fungi community to microplastics pollution was greater than that of bacteria community, and further attention should be paid to rhizosphere soil monitoring in the future.

Due to agricultural film fragmentation, sewage irrigation and other anthropogenic activities, the content and abundance of microplastics in soil are gradually surpassing those in the ocean, and becoming one of the main pollution sources of soil. Soil organisms can absorb soil microplastics, among which microplastics in food crops can enter the human body through the food chain, causing the risk of human microplastic exposure. In addition, soil microplastics can also directly cause toxicity to soil. The sources, migration and other environmental behavior of microplastics in soil ecosystem were summarized, and the impact of microplastics on soil ecosystem was emphasized. The results mainly include the following aspects: (1) Microplastics can migrate and transport in the soil environmental system through the space between soil particles, the root cracks of plants and the movement of animals. (2) Microplastics can affect soil physical and chemical properties, plant growth and development, animal behavior and microbial diversity. (3) Microorganisms and enzymes can degrade microplastics in the soil environment and directly reduce microplastics in the soil system, while biochar can reduce the toxicity of microplastics to the soil ecosystem. All three are potential options for soil microplastics remediation technologies. Finally, the possible research direction of soil microplastics in the future was proposed, in order to provide guidance for the pollution control of soil microplastics.

To explore the occurrence characteristics of microplastics in reservoir water and organisms, Wudu Reservoir was selected as the research area, and microplastics in surface water of different areas and fish in the reservoir were sampled and analyzed in the wet period in 2022. The results showed that the average abundance of microplastics in the surface water of Wudu Reservoir in September 2022 was (63.61±16.26)n/L, and there was no significant difference in the abundance of microplastics at the head, middle and end of the reservoir. Moreover, the average abundance of microplastics in the gastrointestinal tract, gills and muscle was (13.61±8.43), (12.22±4.99), and (4.66±3.34)n/g, respectively. In addition, the abundance of microplastics in muscle was significantly lower than that in the gastrointestinal tract and gills (P<0.05). The results of microplastic composition and size analysis showed that polyvinyl chloride (PVC) and polyamide (PA) accounted for the largest proportion of microplastics in both water and fish, and microplastics with small particle size (20-50 μm) were mainly in both water and fish. The results of correlation analysis showed that the chemical composition and particle size composition of microplastics in surface water were significantly correlated with those in fish (P<0.05). The research results could provide data support for the microplastic pollution control scheme of lake and reservoir.

With the dramatic increase in the amount of plastic waste in marine and freshwater environment, the microplastic content in freshwater lakes in cold regions, represented by Lake Ulansuhai, has increased significantly. Ice formation during the freezing period will promote the enrichment of microplastics in the ice cover. In order to deeply understand the environmental migration characteristics of microplastics in cold and frozen regions, a self-made icing device was used to simulate the freezing and thawing periods of lake water, to reveal the influence of microplastics on the growth rate and melting rate of ice thickness, and ice density. The results showed that the existence of microplastics could promote ice growth, and the ice thickness growth value showed a trend of increasing first and then decreasing with the increase of microplastic abundance. Microplastics played an obstructive role in the melting of the ice, and with the increase of microplastic abundance, the obstructive role was more obvious. Observations of the density of ice samples under different conditions revealed that the change in ice density was dominated by the abundance of microplastics and the freezing temperature, while the particle size of microplastics had a slight impact, which was a combined effect. The microplastics abundance and icing temperature affected the process of ice formation and melting, as well as changes in the ice density.

Focusing on the source characteristics (including water source and packaging materials) of microplastic pollution in bottled water and the bottleneck problem restricting the detection of small-particle microplastics, different brands and different types of bottled water commonly available on the market were selected as research objects, and the concentrations of microplastics (PP, PE, PS, PVC, PET) in the water samples were detected by automatic thermal desorption-gas chromatography-mass spectrometry (ATD-GCMS). The results showed that the main components of microplastics in bottled water were PVC [(2.95±2.03)μg/L], PET [(1.84±2.14)μg/L] and PE [(1.86±1.84)μg/L]. There were significant differences in PVC (P<0.05) and PET (P<0.05) contents in the bottled mineral water, but no significant differences in PE contents. By contrast, there was no statistical significance of PVC and PET contents in different brands of purified water, but there were significant differences in PE contents (P<0.05). The occurrence of microplastics in bottled water was affected by microplastic pollution in source water and the release of microplastics in packaging materials. By comparing and analyzing the occurrence characteristics of microplastics in bottled drinking water, data support should be provided for the future development of management measures to reduce the risk of microplastic intake by drinking water and to prevent and control the health risks.

To explore the accumulation of respiratory nanoplastics in tissues out of respiratory system, the 100 nm polystyrene nanoplastics were used to perform a 2h-short term uptake exposure to SD rats, and the polystyrene concentrations in liver, kidney, heart, and brain of rats were determined with pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The results showed that the concentrations in the kidney, heart, and liver of the exposure group [(0.416±0.143), (0.633±0.278), and (0.617±0.179) g/g] were significantly higher than those of the control group [(0.249±0.020), (0.070±0.096), and (0.101±0.140) g/g] (P<0.05), but no significant correlation were found among different tissues (P>0.05), and polystyrene was not detected in the brain of both the control and exposure groups. The results show that the nanoplastics can enter the blood circulation of rats through the alveoli and deposit in tissues such as liver, kidney, and heart shortly after 2 h of inhalation exposure of 100 nm polystyrene nanoplastics. The study preliminarily explored the accumulation characteristics of nanoplastics in organisms, and could provide data support for further research on the potential impacts of respiratory nanoplastics on human health.

In order to understand the pollution characteristics of pollutants in imported recycled plastic particles, five different types of imported recycled plastic particles were selected. Based on the source and recycling process, the possible types of pollutants were identified. Three characteristic pollutants, namely heavy metals, bisphenol compounds (including tetrabromobisphenol A (BPA) and tetrabromobisphenol S (BPS)), and volatile organic compounds (VOCs), were screened out and their pollution characteristics were analyzed. The results showed that six heavy metals, Cr, Mn, Pb, Cd, Cu, and Hg, were detected in the five types of recycled plastic particles, with relatively high concentrations of Cr, Mn, and Pb. The detection rate of BPS reached 100%, and the detection rate of BPA was between 20% and 100%. The mass concentration of BPS in the five recycled plastic particles was greater than that of BPA, which may be related to the use of BPS or other substitutes for BPA in actual production. Most of the detected VOCs, except for dichloromethane, were homologues of benzene. The results could provide basic data support for subsequent recycling work and help relevant departments further regulate the control of imported recycled plastic particles.

Under the carbon peaking and carbon neutrality goals, the high-quality economic development of seven cities along the Yellow River basin in Inner Mongolia is a key way to realize the high-quality development of the region. In order to explore the influencing factors of carbon emissions and predict the peak of carbon emissions, the panel data of seven cities along the Yellow River basin in Inner Mongolia from 2005 to 2022 was selected, and the Ridge regression and the extended STIRPAT model were used to study the six influencing factors, including population size, urbanization rate, and GDP per capita, as well as the interaction of them, on the carbon emissions of the seven cities. Based on scenario analysis, the trends and peak levels of carbon emissions of the seven cities from 2023 to 2035 were predicted. The results show that: from 2005 to 2022, the carbon emissions of seven cities showed a fluctuating upward trend; the increase in population size, urbanization rate, and GDP per capita can lead to an increase in carbon emissions, while the reduction in energy intensity and carbon intensity can slow the increase in carbon emissions. The interaction of urbanization rate with GDP per capita can lead to a further increase in carbon emissions of the seven cities, while the interaction of population size and GDP per capita, and the interaction of energy intensity and industrial structure can effectively curb the increase in carbon emissions in the region; the trend of changes in carbon emissions of the seven cities have bigger differences under six different forecast scenarios, under both the high carbon and benchmark scenarios, carbon emissions will not peak by 2030, while the other four scenarios will all peak carbon emissions by 2030. The order of carbon emission reduction effectiveness under these scenarios is as follows: comprehensive low-carbon scenario, energy intensity reduction scenario, carbon emission intensity reduction scenario, and industrial structure optimization scenario. Therefore, the comprehensive optimization of industrial structure, the development of clean energy, and the breakthrough of green industrial technology are the optimal strategies for achieving the synergistic development goals of economy, energy conservation and emission reduction in the seven cities along the Yellow River basin in the Inner Mongolia Autonomous Region.

In order to conduct energy consumption and carbon emission prediction analysis at the regional level, energy consumption and carbon emissions in Anhui Province were taken as the research object. By constructing a LEAP Anhui prediction model, three scenarios including baseline scenario (BAS), development planning scenario (DPS), and energy conservation and emission reduction scenario (ERS), were designed to predict three different development paths in Anhui Province. The prediction results show that by 2035, the total energy consumption under BAS scenario will reach 2.3459×10⁸ t (energy consumption is calculated based on standard coal), and compared to BAS scenario, the total energy consumption under DPS and ERS scenarios will decrease by 20.6% and 30.7%, respectively. The total energy consumption under ERS scenario will reach its peak in 2030, with a peak of 1.6416×10⁸ t. Under BAS scenario, the total carbon emissions in Anhui Province will reach 5.122×10⁸ t by 2035, with an average annual growth rate of 2.6%. Under DPS and ERS scenarios, the total carbon emissions will peak in 2030 and 2025, with 3.891×10⁸ t and 3.572×10⁸ t, respectively, both of which were able to fulfill China's commitment to achieve carbon peak before 2030. Based on the carbon constraint target, an optimization analysis was conducted on the energy structure of Anhui Province. Under the constraint path, the proportion of clean energy allocated to the three major systems is 39.3% for the tertiary industry, 23.3% for residential living, and 37.4% for the secondary industry. The minimum demand for clean energy is 1.07×10¹⁸ J, accounting for 20.6% of the total energy demand.

To achieve carbon peak and neutrality targets and control watershed water pollution, township sewage treatment plants (STPs) need to collaborate in reducing pollution and carbon emissions. Based on water quality and quantity data from 2016 to 2022 at a municipal sewage treatment plant in a township in Chengdu, the temporal variability of COD, NH₃-N, TP, and TN was analyzed before and after the standard enhancement and upgrading. Using 2006 IPCC Guidelines for National Greenhouse Gas Inventories (2019 revision) and Guidelines for Carbon Accounting and Emission Reduction in the Urban Water Sector, the characteristics of direct and indirect carbon emission intensity were investigated, and the response of carbon emissions to seasons, water quality, and pollutant reduction amounts before and after the standard enhancement and upgrading was explored. The results showed: (1) After upgrading from Cyclic Activated Sludge System (CASS) to Anaerobic-Anoxic-Oxic -Membrane Bioreactor (AAO-MBR), the effluent quality met Emission Standards for Water Pollutants in Minjiang and Tuojiang River Basins of Sichuan Province (DB 51/2311-2016). Moreover, by increasing carbon source, using MBR membrane to trap sludge and other measures, the effluent concentration and water quality indexes were more stable, and the treatment efficiency of pollutants was higher. (2) After upgrading, direct and indirect carbon emission intensities increased by 41.59% and 105.70%, respectively, with values of 0.296 and 1.082 kg/m³ (in terms of CO₂-eq). In summer, the carbon emission intensity was significantly lower than that of other seasons (P<0.01), and indirect carbon emission intensities before and after the upgrade remained higher than direct carbon emission intensity. (3) After the upgrade, the total carbon emission intensity increased by 0.643 kg/m³(in terms of CO₂-eq). Due to increasing electricity consumption caused by upgrading, the indirect carbon emission intensity significantly changed. Therefore, the township STP upgrading could not only improve treatment efficiency but also increase carbon emissions. It was recommended to consider pollutant removal and energy consumption control synergistically during process transformation to achieve pollution reduction and carbon emission reduction simultaneously.

In semi-enclosed street canyons, traffic emissions and secondary pollutants tend to accumulate in poorly ventilated areas, posing a serious threat to public health. Among the various factors influencing flow dynamics and pollutant dispersion within street canyons, insufficient attention has been given to the thermal buoyancy effect caused by solar radiation on building walls and the impact of different tree trunk heights on aerodynamics. The effects of different tree trunk heights (coupled tree shading effect) and wall heating conditions on air flow and pollutant diffusion in urban street canyons were studied. Five different tree trunk heights (h=0.18H, 0.40H, 0.62H, 0.84H, 1.06H) combined with four wall heating configurations were considered for analysis purposes. The numerical results demonstrate that variations in tree trunk height and the thermal effects of walls significantly impact air flow and pollutant diffusion within urban street canyons. When the trunk height is lower than that of the building, wall heating generates thermal buoyancy which can reduce pollutant concentration in the street canyon and enhance ventilation performance. However, when the trunk height exceeds that of the building, thermal buoyancy generated by windward wall heating hinders pollutant diffusion. Using full-wall heating can achieve a lower accumulation of pollutants. The research results can provide technical guidance for the optimal design of urban green facilities and the precise control of local microclimate environment and air quality.

To investigate the influence of shrub hedge layout on the flow field and pollutant dispersion in elevated bridge street canyons, the shrub hedges were assumed to be porous media, and the standard k-ε model was used in combination with the species transport equation in the simulation. The diffusion process of CO emitted from motor vehicles on the bottom and bridge deck of the elevated bridge street canyons with central two-side shrub hedges was simulated separately. The simulation results were compared and validated with wind tunnel test ones. The results indicate that this numerical simulation method is reliable, and unlike standard street canyons, the shrub hedges in elevated bridge street canyons not only do not hinder the movement of the flow field, but also enhance the convection between the blocked wind field at the bottom and top. This is beneficial for the dispersion of pollutants emitted from the bottom of the road, and can effectively reduce the overall pollutant concentration in the street canyon and improve the issues of pollutant accumulation on the leeward side, above the bridge deck, and at the bottom. When hedges are set on both sides, the convection between the upper and lower wind fields is stronger, and the CO concentration at the leeward wall is reduced by 60%. Therefore, adding shrub hedges can be an effective measure to reduce the level of air pollution in elevated bridge street canyons.

Mobile monitoring is a technique for conducting environmental quality assessments by deploying monitoring equipment on mobile platforms like cars, bicycles, unmanned aerial vehicles (UAVs) and boats. Due to its flexibility, mobility, and real-time capabilities, mobile monitoring technology has gained widespread application in recent years, particularly in atmospheric environmental monitoring. However, there is a shortage of systematic research regarding the application scenarios, advantages, and drawbacks of mobile monitoring technology in atmospheric environmental research. A literature-based review of the foreign and domestic applications of mobile monitoring technology in atmospheric environmental research was conducted, with a focus on the monitoring equipment and the platforms used for atmospheric environmental mobile monitoring. The mobile monitoring equipment is categorized into two groups: sensors and large-scale devices. Sensors, characterized by their compact size and cost-effectiveness, find extensive use on platforms like UAVs and automobiles. Conversely, large-scale devices, including monitors and analyzers, are primarily employed on larger platforms like aircraft and ships, mainly due to size and cost constraints. Atmospheric environmental mobile monitoring platforms are classified into three categories: vehicle-based, aircraft-based, and ship-based. Vehicle-based mobile monitoring is primarily employed for environmental quality assessment, traceability analysis, hotspot monitoring, vehicle emissions tracking, and air pollution exposure measurement. Aircraft platforms play a key role in monitoring ambient air quality, traceability analysis, hotspot monitoring, and the tracking of atmospheric pollutant dispersion. Ship-based mobile monitoring platforms are chiefly utilized for studying sea surface atmospheric components, traceability analysis, and ship exhaust emissions research. Finally, current challenges in existing applications of mobile monitoring platforms, such as coverage, battery life, and data quality, were addressed, and future perspectives were presented for the field.

Selective catalytic reduction (SCR) systems are typically used to reduce nitrogen oxides (NO_x) emitted from diesel engine exhaust emissions. To further improve its de-NO_x performance, firstly, a three-dimensional numerical simulation model was established. The non-uniform distribution of the catalyst was achieved by changing the porosity in the SCR converter, and the impact of the non-uniform distribution of the catalyst under different engine loads on the flow, mass transfer, and heat transfer performance of the SCR system was investigated. Secondly, the impact of the non-uniform distribution of the catalyst on the performance of the SCR system was examined and compared with that of the uniform distribution. Finally, based on the principle of field synergy, the influence of velocity and temperature fields on the heat transfer process in the SCR system was analyzed. The results indicate that the non-uniform distribution of catalysts can improve the performance of SCR systems. At 25% engine load, compared to a uniform distribution, the pressure drop of Case P-R5 is reduced by 165 Pa, the conversion efficiency of NO_x is increased by 0.8%, and the escape of ammonia is reduced by 7 mg/L. In addition, the temperature gradient of Case P-R5 is higher than the maximum peak of the temperature gradient of the catalyst with uniform porosity, indicating that there is less energy transferred to the outside. The non-uniform distribution of the catalyst structure can maintain the temperature of the catalytic region, improve the catalyst activity, and facilitate de-NO_x reactions.

The Pressure State Response (PSR) model can reflect the impact of socioeconomic conditions on the ecological environment of lake water bodies. Based on the PSR model, an evaluation index system was constructed, which included 18 indicators such as population density, vegetation index, water exchange cycle, and phytoplankton diversity index. The years 1999 and 2007 were selected as the historical control years, and the ecologicalhealth status of Lake Taihu Basin from 2011 to 2020 was compared with the control years. The results displayed: (1) The weights of the state layer, pressure layer, and response layer were 0.418, 0.291 and 0.291, respectively. The indicators that had a greater impact on the ecological health of Lake Taihu Basin were mainly the coverage of large aquatic vegetation, the rate of reaching the standard of total phosphorus in lakes, the proportion of environmental protection investment in GDP, the comprehensive trophic status index (TSI) of lakes, the utilization and development rate of water resources, and the diversity index of phytoplankton, with an overall contribution rate of 51.74%. (2)The ecological health assessment results of Lake Taihu Basin in 1999 and 2007 were unhealthy, and it was generally healthy to healthy from 2011 to 2020. The ecological health assessment index decreased in 2015 and 2017, but the overall health status of the basin was improving in 2011-2020. After 2011, the improvement of Lake Taihu Basin health was mainly due to pollution control, ecological restoration and management of the state and local government. The fluctuation of the basin ecological health index in 2015 and 2017 was mainly due to adverse meteorological factors. (3)Changes of large aquatic vegetation coverage, total phosphorus compliance rate, TSI, and phytoplankton biodiversity index were consistent with the changes of ecological health assessment index and the health level of Lake Taihu Basin. In the past 20 years, the increase of the proportion of environmental protection investment in GDP and the optimization of water resources development and utilization had alleviated the adverse impact of the decline of the four indicators on the ecological health of Lake Taihu Basin to a certain extent.

In order to identify the water environmental problems in the Zhaolan Xin River, a systematic survey, monitoring and data analysis on water quality, substrate and water ecology from summer 2021 to spring 2022 were conducted. A three-level hierarchical evaluation system was constructed by a multi-index comprehensive analysis method, seven aspects, including physical integrity, water resources and safety, water quality, etc., were selected to build a comprehensive assessment index system for the health of the river ecosystem of the Zhaolan Xin River, and its health status was evaluated. The results showed that Qingken Lake, the source of the Zhaolan Xin River, was with serious pollution, and the mainstream pollution was mainly from agricultural non-point sources. The water ecosystem was subject to high levels of human disturbance, and the river ecosystem was fragile. The overall health evaluation score of the Zhaolan Xin River was 0.26, ranging from 0.20 to 0.40, and the rating was "poor". Among them, the overall health evaluation scores of the upper, middle and lower reaches of the river were all lower than 0.4 in all the seven aspects, with some scores below 0.2, and the evaluation rating was "poor" or "extremely poor". It was proposed that the future governance strategy should focus on three aspects, i.e. river management, water pollution control and water ecological restoration, and measures of optimizing section layout, deeply controlling pollution sources and dredging should be implemented to achieve improvement of ecological environment in the Zhaolan Xin River in the future.

Huangtai algae outbreaks are an important environmental problem for the water environment and ecological health of Ulansuhai Lake, and it is of great practical significance to identify the distribution of Huangtai algae and explore the key factors affecting it for the prevention and scientific control of huangtai algae outbreaks. Based on the satellite remote sensing images and unmanned aerial photography data from 2013 to 2020, the distribution of Huangtai algae in Ulansuhai Lake was identified and the area statistics were conducted by using the random forest (RF) method, and then the key factors affecting the change of Huangtai algae area were screened by using the grey correlation analysis (GRA) model. The results showed that the ten-fold cross-validated random forest model achieves 99% accuracy on the training set and 92.8% average accuracy on the test set. In terms of the interannual trend, the Huangtai algae area fluctuated greatly in 2014-2015 and 2016-2017, decreasing from 18.92 to 10.59 km² and increasing from 13.31 to 22.48 km², respectively, while at the same time, the Huangtai algae area of other years was relatively stable. In terms of spatial variation, Huangtai algae were more densely distributed in the inlet area and the center of Ulansuhai Lake. In addition, the results of the GRA showed that the correlation between the area of Huangtai algae and water quality indexes changed dynamically in different growth periods. Specifically, the change of Huangtai algae area was significantly affected by water temperature and organic matter concentration in May, more affected by comprehensive environmental factors (water temperature, organic matter concentration and nitrogen and phosphorus nutrients) from June to August, and more affected by nitrogen, phosphorus and other nutrients as well as competitive relationship in September. The study revealed the complex interaction between the growth of Huangtai algae and water quality factors and biological competition, which could provide a scientific basis for the control of Huangtai algae and the health maintenance of water ecosystem.

In order to effectively promote the utilization of low-polluted water in the Nine Plateau Lake Basins in Yunnan Province, based on the data of urban sewage treatment plants, meteorology, and agricultural irrigation in the lake basins in 2021, the total amount of low-polluted water in the lake basins in 2021 was calculated from two aspects, i.e. the tail water of urban sewage treatment plants and the drainage volume of farmland runoff. The current utilization situation was analyzed based on actual investigations. The results showed that: 1) In 2021, the total amount of low-polluted water generated in the Nine Plateau Lake Basins was 1 507.360 7 million m³, of which the tail water from urban sewage treatment plants was 825.441 4 million m³, and the drainage volume of farmland runoff was 681.91 93 million m³. 2) The total amount of low-polluted water reused in the Nine Plateau Lake Basins was 462.794 4 million m³, with a reuse rate of 30.70%. The water reuse rate of urban sewage treatment plants was 54.46%, with the highest reuse rate in Dianchi Lake Basin, mainly used for landscape water, followed by agricultural irrigation and urban miscellaneous use. The reuse rate of farmland runoff drainage was 1.94%, mainly achieved through the construction of regulation and storage belts in basins such as Erhai Lake, Fuxian Lake, Qilu Lake, and Xingyun Lake. Among them, Xingyun Lake Basin had the highest amount of farmland runoff drainage reuse. 3) There was still a lot of utilized space for the reuse of low-polluted water in the lake basins. Different goals for low-polluted water reuse could be set based on industrial structure and development positioning in different lake basins, and water quality monitoring of farmland runoff drainage should be strengthened. According to the water quality concentration of farmland runoff drainage in different periods, the purpose and destination of farmland runoff drainage should be determined scientifically and reasonably, the storage and purification function of the regulation and storage belts be fully utilized, and the comprehensive utilization among the tail water of sewage treatment plant, farmland retreat water and initial rainwater be strengthened. It was recommended to select typical areas within the Nine Plateau Lake Basins to carry out pilot projects for the allocation of low-polluted water. Through pilot demonstrations, successful experiences could be summarized, and a replicable and promotable low-polluted water utilization model be formed to promote the reuse of low-polluted water in the basin.

To improve the purification efficiency of ditches in winter and spring, the ecological ditch was constructed by adding floating blankets with the cold-tolerant plant (Lolium perenne L.) and permeable dams with adsorption filler in the original soil ditch. The removal rates of main pollutants in farmland runoff by the ecological ditch were analyzed, the purification efficiencies of pollutants in different treatment segments were compared and the contributions of plant absorption to the total pollutant flux reduction were estimated. The results showed that the average values of the total removal rates of total nitrogen (TN), nitrate nitrogen (${\mathrm{NO}}_ 3^-{\text{-}}{\mathrm{N}}$), total phosphorus (TP), chemical oxygen demand (COD) and suspended solids (SS) were 29.06%, 54.93%, 20.76%, 54.08% and 49.85%, respectively. The removal rates of TN and ${\mathrm{NO}}_ 3^-{\text{-}}{\mathrm{N}}$ were highest in the permeable dam section of the ecological ditch; the removal rates of TP and COD were highest in the permeable dam section combined with floating blankets; the removal rate of SS was highest in the floating blankets section, and the purification efficiencies of ${\mathrm{NO}}_ 3^-{\text{-}}{\mathrm{N}}$, TP and COD were also better in the floating blankets section. In the nine days with more than 10 mm of rainfall during the experiment, the total reduction amounts of pollutant flux of TN and TP were 11.43 and 0.27 kg, respectively. The nitrogen and phosphorus amounts absorbed by Lolium perenne L. accounted for 20.6% and 55.6% of the total reduction amount of pollution flux of TN and TP, respectively. When the temperature dropped below 0 ℃ after the melting of heavy snow, the concentrations of nitrogen and phosphorus in snow-water runoff increased significantly, which might be due to soil freezing and thawing. Meanwhile, as the purification efficiencies of nitrogen and phosphorus in snow runoff by ecological ditch were not significant, nearby ponds and rivers could be utilized as temporary storage of the runoff, and further enhanced treatment of pollutants could be implemented in combination with ecological measures.

Antibiotics and endocrine disruptors are emerging contaminants that have attracted global attention in recent years. Based on the databases of China National Knowledge Infrastructure (CNKI) and Web of Science (WoS), relevant literature on the environmental behavior of antibiotics and endocrine disruptors in rivers was retrieved. CiteSpace and VOSviewer software were used for bibliometric analysis and visualization display. The results showed that a total of 2 085 relevant papers were searched in CNKI and WoS from 2000 to 2022, including 399 Chinese articles and 1 686 English articles. The research in this field showed an upward trend and increased rapidly in the past five years. The English literature involved 96 countries and 2 022 institutions, and the international performance of China and the United States was the most prominent, with 773 and 251 articles published respectively. The University of Chinese Academy of Sciences ranked first in publications and cooperated closely with institutions at home and abroad. The journals published were mainly in the field of environmental science with interdisciplinary integration, with Environmental Science (Chinese) and Science of the Total Environment topping the publications. The keywords clustering and time zone maps showed that regional research was mainly focused at present. The pollution characteristics of endocrine disruptors including bisphenol A, nonylphenol and organochlorine pesticides, and antibiotics including sulfonamides, tetracyclines and quinolones in rivers were most widely studied, while research on hormonal endocrine disruptors was still insufficient. Study on the migration, transformation and removal mechanisms of the pollutants in rivers was the main trend. The results of keywords of strongest citation bursts indicated that the research in this field over the past 20 years could be divided into three stages. In the early stage, research mainly focused on analysis methods and investigation on the occurrence and characteristics of the contaminants in rivers. In the mid-term, studies primarily concentrated on examining the contaminant transport and fate. In recent years, it has shifted from ecological risk assessment to river water ecological health management services, and the development of pollution control strategies and removal technologies based on regional characteristics are current hotspots and future trends. Besides, the issue of antibiotic resistance originating from antibiotic contamination has garnered global attention, and the generation and transmission mechanism of antibiotic resistance genes and their ecological and health risk are also current hotspots and possible future focus.

Regeneration and utilization of wastewater in the chip industry is of great significance to reduce water pollution, alleviate water shortage and promote the green development of the chip industry. In order to clarify the phytotoxic effects of reclaimed water from the chip industry on plants, petunia hybrida was used as a model organism to analyze the response characteristics of growth morphology, total protein, chlorophyll, antioxidant system and energy system biomarkers, and to evaluate environmental risks based on the second-generation Integrated Biological Responses version 2 (IBRv2) during irrigation with two types of reclaimed water. The results showed that there was no obvious adverse effect on the growth and morphology of petunia hybrida irrigated with two kinds of reclaimed water. At the middle stage of irrigation (9 days), the total protein and chlorophyll of petunia hybrida were significantly induced, and then the induction was relieved and the inhibition began to appear. At the middle and late stage of irrigation (9-15 days), the antioxidant biomarkers of petunia hybrida were mainly inhibited, but no obvious oxidative damage to petunia hybrida occurred. The response patterns of energy system biomarkers were inconsistent during irrigation. The average values of IBRv2 for the two types of reclaimed water from chip industry were between 0.85 and 1.72, and the environmental risk level was low. However, because the reclaimed water still contained high concentrations of chloride ion and total dissolved solids (TDSs), the sensitive biomarker combination of glutamate dehydrogenase, pyruvate kinase, malondialdehyde (MDA) or superoxide dismutase, MDA could be selected to monitor and control the environmental risk. It was recommended to further research and develop the treatment process which could effectively reduce the concentration of chloride ion and TDS in the reclaimed water of chip industry, so as to ensure the ecological environment safety of the reclaimed water for green irrigation.

With the widespread application of flocculants in water and sewage sludge treatment, the potential single or joint toxic effects of their residues in treatment systems are increasingly receiving attention. Polymeric iron sulfate (PFS), polymeric aluminum chloride (PAC) and polyacrylamide (PAM) were used as research objects to explore their potential toxic effects through single toxicity and joint toxicity tests using luminescent bacteria. The results showed that: 1) In the single toxicity test, median effective concentration (EC₅₀) value of PFS, PAC and PAM of luminescent bacteria were 29.41, 71.82 and 1 072.64 mg/L, respectively. The single toxicity effect order was PFS>PAC>PAM. 2) In the joint toxicity of binary flocculants test, PFS-PAM had synergistic effect when mixed with the toxicity ratio of 1∶1, while PAC-PAM had antagonistic effect when mixed with the toxicity ratio of 1∶3 and 3∶1. 3) The concentration addition (CA) and independent action (IA) models were used to predict joint toxicity. The results of PFS-PAM were consistent with the predicted values of CA model, while the results of PFS-PAC and PAC-PAM were consistent with the predicted values of IA model. 4) The three-dimensional deviation response surface results showed that the deviation between experimental observations and CA model (dCA) and IA model predictions (dIA) values changed with the mass concentrations of the flocculants. The CA model was consistent with the results of PFS-PAC, when the mass concentrations of PFS and PAC were high, while for the PAC-PAM system, the prediction of IA model was better than that of CA model. The results indicate that PFS and PAC have higher toxic effect on luminescent bacteria, and the combined use of PFS and PAM may increase the toxic effect and pose environmental risks to microorganisms in water treatment systems.

To address the need for studying the variations in dissolved organic matters (DOMs) in wastewater from sewage treatment plants (STPs) and their correlation with nitrogen transformation, three-dimensional fluorescence spectroscopy, parallel factor analysis, and correlation analysis were employed, and STPs in a city in southwestern China was chosen as the research object to investigate the changes in DOM fluorescence components across different process units and their correlation with nitrogen transformation during the dry season. The results showed that: (1) DOMs in the wastewater of the STPs consisted primarily of four fluorescence components, that was protein-like components C1 (tyrosine-like), C2 (tryptophan-like), and humic-like components C3 and C4. The influent of the STPs was primarily dominated by protein-like components, which accounted for an average of 66.5% of the total fluorescence intensity. Among the protein-like components, C1 had a relatively high content, representing an average of 54.6% of the fluorescence intensity. The effluent was primarily dominated by humic-like components, which accounted for an average of 71.7% of the total fluorescence intensity. Among the protein-like components, C2 had a higher content, representing an average of 99.8% of the fluorescence intensity. (2) The fluorescence intensity of DOMs generally decreased as the treatment process progressed. In particular, the fluorescence intensity of component C1 gradually approached zero. On the other hand, the humic-like components remained relatively stable and did not change throughout the treatment process. (3) The fluorescence index (FI) values of DOMs after passing through the biological treatment units of the STPs were all above 1.9, suggesting that DOMs were predominantly converted into endogenous sources. (4) A strong correlation was observed among ${\mathrm{NH}}_4^+{\text{-}}{\mathrm{N}} $, dissolved total nitrogen (DTN), component C1, and the humification index (HIX) in the STPs. Multiple regression could effectively predict the concentrations of ${\mathrm{NH}}_4^+{\text{-}}{\mathrm{N}} $ and DTN in water. A recommendation was made for the STPs to develop a more comprehensive model using the extensive data on DOM spectral properties and nitrogen (${\mathrm{NH}}_4^+{\text{-}}{\mathrm{N}} $ and DTN). This model would be able to predict the nitrogen trends in both the effluent and receiving water bodies.

Three-compartment septic tank (TcST) with high concentrations of effluent COD, nitrogen and phosphorus would cause local water pollution or black odor when tailwater was directly discharged or overflowed. In view of the above problems, an equal-volume five-compartment purification tank reactor (FcPTR) was constructed and, taking actual domestic sewage as the treatment object, the operating characteristics and unit pollutant removal cost were compared and analyzed. The results revealed that when FcPTR operated continuously for 120 days, average concentrations of effluent COD, TN, $ {\rm {NH}}_4^+ {\text{-N}}$, TP were 74, 26, 20, and 1.6 mg/L, respectively, which could reach Class Ⅱ of local standards for water pollutants discharge from rural domestic facilities that had been issued by 11 provinces (autonomous region, municipality directly under the Central Government) in China when applied in rural areas where the quality of the influent water was similar. The removal of nitrogenous and phosphorus-containing materials was promoted by the growth and metabolism of Proteobacteria on the filler and sludge in the anaerobic baffle zone and aerobic zone. Compared with TcST, FcPTR could significantly enhance the degradation of organic matter and denitrification and phosphorus removal, and improve the shock load resistance. According to cost accounting, when operating for 10 years with the same design volumes and operating scenarios, FcPTR could reduce the cost of 1 kg COD and 1 kg $ {\rm {NH}}_4^+ {\text{-N}}$ removal both by 19.8% compared with TcST.

Solide carbon source denitrification technology is a pivotal strategy for treating low carbon-to-nitrogen (C/N) wastewater, and the important factor affecting the efficiency of biological denitrification is the characteristics of the carbon source. The advantages and application prospects of various types of solid carbon sources, including synthetic biodegradable polymers, natural cellulosic substances, and mixed solid carbon sources, were compared and elucidated, aiming at the unclear principle of their application in nitrogen removal. Detailed analysis was conducted on the influences of physical and chemical properties of carbon sources (such as synthetic substances, carbon released composition, and surface characteristics) and the dosing sites, etc. on the biological denitrification process. The results indicated that the carbon release and its subsequent utilization rate by denitrifying microorganisms were crucial determinants of denitrification efficiency. By optimizing material composition and mixing methods to modify the material characteristics, carbon release could be maximized and the released components could be better utilized by denitrifying microorganisms. It was proposed that the future solid carbon source field should focus on enhancing carbon release capabilities and denitrification rates through advancements in the synthesis of carbon sources and the elucidation of electron transfer mechanisms, to deeply develop and promote novel solid carbon sources.

Due to the demand of urban flood control, drainage and non-point source pollution control in China, the proportion of separate drainage system in cities is increasing, and the initial rainwater pollution caused by separate drainage system has become one of the main causes of urban water pollution. Based on the research results at home and abroad, the research hotspots of the initial rainwater pollution in the separate drainage system were analyzed by using the bibliometrics method, and the sources, pollution characteristics, different control measures and reduction efficiency of the initial rainwater pollution in the urban separate drainage system were comprehensively analyzed. The results showed that pipe deposition was a common problem in the separate drainage system in China, and the pollutants in the urban underlying surface and pipe sediment were the main sources of initial rainwater pollution. Source and pipeline sediment erosion were the main reasons affecting the change characteristics of the initial rainwater quality. In addition, the initial rainwater pollution was also affected by various factors, such as rainfall characteristics, the type of underlying surface, the number of sunny days before rain, and air pollution status. According to the pollution sources and characteristics of the initial rainwater, engineering control measures should be combined with non-engineering control measures to carry out comprehensive control from the source, process, end, and laws and regulations, so as to reduce the pollution caused by the initial rainwater of the urban separate drainage system and improve the quality of the urban water environment.

Overflow pollution during flood season in areas with combined sewer system has become an important reason for the return of urban rivers to blackness and odor, and the effective control of overflow pollution plays an important role in improving the water environment quality and enhancing people's sense of well-being, accessibility and security. In view of the prevention and control of overflow pollution in flood season in areas with combined sewer system, the characteristics of overflow wastewater, the influence on water environment quality, and the influencing factors of overflow pollution were summarized. The distribution characteristics of areas with severe overflow pollution were analyzed and the control suggestions were put forward. The study found that the overflow wastewater from combined sewer systems in China had the characteristics of complex composition, large changes in water quantity and quality, and poor quality of initial rainwater, which caused urban non-point source pollution and led to the deterioration of surface water. By analyzing the countrywide distribution of two main influencing factors of overflow pollution, i.e. precipitation and pipe network conditions, it was preliminarily identified that the areas with serious overflow pollution were mainly distributed in the south and east of China. The correlation analysis showed that there was a moderate correlation between precipitation in flood season, pipe network density and regional water quality. In order to strengthen the prevention and control of overflow pollution in areas with combined sewer system, some specific suggestions were proposed, including developing discharge control standards for overflow pollution according to local conditions, updating technologies for controlling and treating overflow wastewater, enhancing the whole process management of overflow pollution in flood seasons, and strengthening effectiveness assessment of overflow pollution control and treatment, and so on, which hopefully could provide support for effective control of overflow pollution and promote water environmental quality continuously.

To reveal the heavy metal risks in the soil of vegetable and grain planting areas around the city, and to address the current lack of research on human health risks caused by hand mouth intake, respiratory pathways, and skin contact exposure pathways, as well as to estimate the health risks of adults and children from different sources, the surface soil of farmland in Xiqing District, Tianjin City was taken as the research object, and the concentrations of 8 heavy metals including Cr, Cu, Ni, Pb, Zn, As, Hg, and Cd were analyzed. Principal component analysis (PCA), positive definite matrix factorization (PMF), and health risk assessment model (PMF-HRA) were used to evaluate the degree, sources, and health risks of soil heavy metal pollution, and to identify the main heavy metal pollutants and their exposure pathways. The results show that Cd and Hg pollution is the most severe among the 8 heavy metals in agricultural soil in Tianjin City, with the average exceeding the background values by 151.9% and 324.1%, respectively. About 15% of the points are at moderate to severe pollution levels. The main sources of heavy metal pollution in the soil of the research area include natural soil formation processes, agricultural production, transportation, coal burning, and pesticide use. Cd (pesticide sources) and Hg (coal-fired sources) are important elements of soil pollution in agricultural land in the study area. There is no significant non-carcinogenic health risk in three exposure pathways: ingestion of crops, hand and mouth ingestion, and skin contact. The total carcinogenic risk index (TCR) of natural sources is the highest, with Cr being the main contributor to childhood total non-carcinogenic risk indices (HI) and childhood TCR in the source contribution; Hg contributes the most to HI in coal-fired sources, while Cu and Zn contribute to HI from mixed sources of pesticides and transportation. The contributions of the above heavy metal elements are closely related to the industrial, agricultural, and transportation activities of surrounding residents, and should be taken seriously.

In order to determine whether the measurement precision and accuracy of the handheld X-ray fluorescence spectrometer (XRF) can meet the requirements of rapid detection of soil environment, in the context of one soil pollution survey project in a certain plot of Jining City, Shandong Province, the concentrations of arsenic (As), copper (Cu), lead (Pb), zinc (Zn), and nickel (Ni) were detected by XRF rapid detection and laboratory methods. The samples were collected from shallow soil layers (0.2-0.5 m) and deep soil layers (1.5-2.0 m). The results indicated that for shallow soil layers, XRF measurements of heavy metal As consistently exceeded laboratory data, while XRF measurements of heavy metals Cu, Pb, Zn, and Ni were lower within an error of ±30% compared to laboratory measurements. The relative deviations (RD) and overall relative deviation standard deviations of heavy metal elements in shallow soil layers (RD: −33.82%-23.53%, standard deviation: 6.79-19.52) were generally smaller than those in deep soil layers (RD: −30.26%-98.36%, standard deviation: 9.53-49.77), and the dispersion degree of relative deviation in shallow soil layers was smaller than that of deep soil layers. Moreover, the determination coefficients (R²) for heavy metals in shallow soil layers (R²: 0.7762-0.9549) were consistently higher than those in deep soil layers (R²: 0.7762-0.9549), indicating a stronger correlation. When XRF was employed for in-field detection of heavy metals in soil samples, it was recommended to avoid large particles in the samples, compact and flatten the testing surface and, for samples with high moisture content, carry out appropriate drying to minimize detection errors. Despite the inherent limitations of handheld XRF detection, the method demonstrates acceptable accuracy and reliability in reflecting the concentration range of soil elements in soil pollution survey projects, meeting the rapid detection requirements of such projects.

In order to solve the problem of poor physical properties of graphite tailings in the process of reclamation, a composite modifier which can improve its air permeability, water retention and structure was developed. Firstly, the effects of corn straw, cow dung and weathered coal on the physical properties of graphite tailings and the range of application amount were investigated through laboratory tests. Secondly, the response surface method (RSM) was used to design the experiment, and the optimal ratio of the composite modifier (corn straw+cow dung+weathered coal) was obtained. Finally, the physical properties of the modified tailings were analyzed in terms of air permeability, water retention and structure, and the effects of the composite modifier on the microstructure were discussed by scanning electron microscopy (SEM).The results showed that when a single modified material was applied, corn straw had the most obvious effect on the permeability of graphite tailings, cow dung had the most significant effect on its water retention, and weathered coal had the strongest effect on its large aggregate content. The optimum ratio of the compound improvers was 4.10% corn straw, 10.49% cow dung and 2.94% weathered coal. At this time, the bulk density, maximum water holding capacity and large aggregate content of graphite tailings were 1.1 g/cm³, 61.71% and 84.51%, respectively. Compared with the graphite tailings before improvement, the total porosity and water-stable macroaggregate content of graphite tailings increased by 17.42% and 14.48%, respectively, and the water holding capacity was also significantly improved. SEM analysis showed that there were obvious cements on the surface of graphite tailings after improvement, and the particles changed from angle-surface contact and edge-surface contact to direct point contact. A large number of particles agglomerated together to form an agglomerated structure. The effect of composite modifier on the physical properties of graphite tailings was verified from the microscopic scale. The results show that the composite modifier has a significant effect on improving the physical properties of graphite tailings, and it is feasible to realize the soil utilization of graphite tailings.

Based on the environmental risk characteristics of tailings ponds in China, the causes of environmental accidents in recent years were analyzed, and the emergency treatment after environmental accidents and environmental secondary disasters were discussed. In view of the practical problems of China’s large stock and diverse types of tailings resources, low comprehensive utilization rate, and the low production management level of mining enterprises in China, some suggestions were put forward. The first is to achieve the comprehensive utilization of tailings resources and achieve the purpose of reducing emissions. The second is to take systematic pollution control for the tailings ponds, especially for the environmental pollution caused by irresistible factors. The third is to strengthen safety management, reduce safety risks such as dam break, and reduce secondary environmental pollution risks from the source of safety accidents.

To address the risk comparison between different hazardous characteristics and explore the classification management of hazardous wastes, toxic and hazardous substances in hazardous wastes were taken as risky substances. Referring to the concept of critical quantity in the risk source evaluation method in Identification of Major Hazard Installations for Hazardous Chemicals (GB 18218-2018) and Classification Method for Environmental Accident Risk of Enterprise (HJ 941-2018), the concepts of hazard value and hazard rate of hazardous wastes were proposed to quantify the hazardousness of hazardous waste, establish hazardous waste grading methods, and grade hazardous waste and waste-producing enterprises. 7 kinds of hazardous wastes from 5 enterprises of the electronic industry in Beijing were sampled and tested, and they were evaluated according to the established method. The results show that the collected hazardous wastes involve flammability, corrosiveness and toxicity, with the hazard rate ranging from high to low being the hazardous wastes with flammability, corrosiveness and toxicity, respectively. The hazard value of waste organic solvents and pickling waste liquid is higher. The hazard values of hazardous wastes of the enterprises in descending order are in the following order A (6.13), B (2.12), C (1.23), E (1.20), D (0.82). The study shows that the hazard rate can distinguish the inherent hazards of hazardous waste itself and can be used as an indicator for hazardous waste classification. The risks of hazardous wastes with different hazardous characteristics can also be compared. The hazard value can be used as a reference for enterprise hazardous waste classification and management.

The sources and types of hazardous waste generated in China are very complex, the production of hazardous waste is enormous and continues to grow, and thus standardized environmental management and pollution prevention of hazardous waste face enormous pressure. Hazardous waste identification is an important technical means and key basis for identifying the hazardous characteristics of solid waste and determining the environmental management objects of hazardous waste. Based on the authors' experience in hazardous waste identification and the review work briefing of the published hazardous waste identification reports, it was found that some identification institutions did not fully grasp the sampling technical requirements in Technical Specifications on Identification for Hazardous Waste (HJ 298-2019) during the hazardous waste identification process, and the sampling was not standardized, resulting in inadequate or even incorrect conclusions for hazardous waste identification. Therefore, the sampling technical requirements for determining the sampling objects of wastewater treatment sludge generated in the production process, the sampling objects of solid waste in the storage state, the number of parallel line solid waste samples, the sampling time and frequency of continuous solid waste generation, the sampling time and frequency of intermittent solid waste generation, and the sampling methods of solid waste generated in the production process were analyzed. At the same time, common incorrect sampling methods were provided, so as to provide reference for sampling in the identification process of hazardous waste.

Exploring the influencing factors of municipal solid waste (MSW) generation under the construction of "Zero-waste City" will help guide cities to formulate effective governance plans. Based on the grey system and taking 11 pilot cities for the construction of "Zero-waste City" in China as the object, the grey correlation analysis method was used to study the relevant influencing factors of MSW generation, and the amount of MSW generated in the next 9 years was predicted through the grey prediction model. The results show that the economic development level of cities has the greatest impact on the amount of MSW, and the influence degree of related influencing factors is in the order of regional GDP > total retail sales of consumer goods > proportion of tertiary industry > per capita GDP. The results of the GM(1,1) model predicting the MSW generation in 10 pilot cities show that the annual growth rate of MSW generation in Chongqing City and Shenzhen City will remain relatively stable from 2023 to 2030, and the annual growth rate of MSW generation in 8 cities, including Weihai City, Panjin City and Sanya City, will decrease year by year, with Tongling City having the largest decrease and Shaoxing City having the smallest decrease. The GM(1,N) model with five relevant influencing factors was used to predict the MSW generation of six pilot cities. The results show that the annual growth rate of MSW generation in Panjin City and Chongqing City from 2023 to 2030 will have a decreasing trend, while the annual growth rate of Shenzhen City, Xuchang City, Sanya City, and Xuzhou City will increase year by year, with the largest increase in Shenzhen City and the smallest in Xuzhou City. The research results could provide effective strategic support for urban solid waste management in the context of "Zero-waste City" construction.

In order to explore the environmental risk of waste acid gypsum sludge produced by the thermal copper refining process, the long-term stability and heavy metal release characteristics of waste acid gypsum sludge were investigated using the methods of simulated stockpiling, static erosion, and semi-dynamic erosion. The findings indicate that the waste acid gypsum sludge has a leaching concentration of As and Cd that is higher than the standard (1488.66 and 22.98 mg/L, respectively), with As reaching an acid-extractable state of 87.55% and Cd effective state exceeding 90%, which poses a serious environmental risk. The results of the simulated stockpiling demonstrate that shower loss and dust should be prevented because waste acid gypsum sludge poses a serious ecological risk level. As and Cd adhered to the surface of waste acid gypsum sludge are leached out in significant amounts by chemical reaction and diffusion during static and semi-dynamic erosion, resulting in concentrations that are all quite high. Among them, the leaching concentration of each element in the landfill simulation environment is significantly larger than that in other simulation environments, which requires special attention.

The coastal zone of Fangchenggang City was taken as an example, its landscape ecological risk and ecosystem service value in different periods were calculated, the spatial correlation of the two was analyzed using spatial autocorrelation, and the ecological restoration zoning of the national land space in the coastal zone were delineated based on the analysis results. The results showed that from 2000 to 2020, the land use type of the coastal zone of Fangchenggang City was dominated by forest land, accounting for about 50% of the study area, followed by sea area (18%), cultivated land (16%) and construction land (6%), and the type conversion of forest land, sea area and construction land in the coastal zone was the most drastic during the study period. The overall ecological risk level of the study area was dominated by lower ecological risk, which accounted for about 32% of the study area, followed by medium ecological risk (26%), low ecological risk (18%) and higher ecological risk (16%), while the area of high ecological risk was smaller, accounting for only about 8% of the study area. The ranges of lower ecological risk and medium ecological risk showed a trend of shrinking during the study period, while the ranges of low, higher and high ecological risk showed an expansion trend. The value of ecosystem services in the study area showed a trend of "increasing first and then decreasing", with a cumulative decrease of 543 million yuan over the 20 years. Based on the results of spatial clustering analysis of landscape ecological risk and ecosystem service value, the study area was divided into ecological priority restoration area, ecological key restoration area, ecological comprehensive enhancement area, ecological preventive management area and ecological conservation and nourishment area. Ecological restoration measures such as restoration of coastal wetlands, cultivation of agricultural land fertility, management of urban inland waterways, enhancement of the completeness of ecological land use, and promotion of natural regeneration of forests and grasses, etc., were put forward for the different sub-areas, respectively.

The value of the biodiversity perceived by the stakeholders will influence their behavior and attitude towards environment protection and thus impact the efficiency and effectiveness of policies related to environmental conservation directly. To characterize the value perception of biodiversity by stakeholders in a specific region more accurately, a method of choice experiment designed from the perspective of flagship species was proposed. The steps of the method included: selecting flagship species for attribute design based on the study area, optimizing and generating the choice experiment questionnaire for the formal survey based on the results of the pre-survey, obtaining the willingness to pay through the questionnaire survey, evaluating the value of biodiversity in a specific region. Applying the methodology in Qinling Mountains (Shaanxi section), giant pandas, golden monkeys, and crested ibis were selected as flagship species, and 1 288 individuals were finally included through field visits and online surveys. The results showed that the marginal monetary willingness to pay of respondents from inside and outside Shaanxi Province for Qinling biodiversity protection was 146.29 and 212.60 yuan per year, and the value of marginal time willingness to pay was 240.12 and 350.01 yuan per year, respectively. According to the marginal willingness to pay, the biodiversity value of Qinling Mountains (Shaanxi section) was estimated to be 489.772-979.545 billion yuan per year. The case study proves that this method can reflect the value of biodiversity in a more comprehensive and comprehensible way, and provide a solid data basis for the formulation and implementation of ecosystem protection policies.

Organophosphorus pesticides (OPPs) have gradually replaced organochlorine pesticides (OCPs) as one of the most widely used pesticides, and their extensive use poses a threat to the environment. Understanding the dynamics and trends of OPPs research in the environmental field is beneficial for researchers and environmental managers in related fields. Using bibliometric methods, literature on OPPs in the field of environment sourced from the core databases of China Knowledge Network (CNKI) and Web of Science (WoS) from 2000 to 2022 were analyzed, and the current status of research, hotspots, and trends on OPPs in the field of environment were systematically clarified. The development trends and emerging frontiers in OPPs research were also described and key future research directions were proposed. The results indicated a significant increase in publications over the last decade, with a total of 3 427 papers published internationally and in China. OPPs in the environmental field were mainly studied in water and soil, and the environmental behavior and characteristics of OPPs in water were more deeply investigated. Gas chromatography was a primary detection method for OPPs. Chlorpyrifos was one of the target pollutants that have been studied more frequently in the research of OPPs, and its detection rate in the environment was high. The research on OPPs in the environment in China and abroad was basically similar, with early-stage research (2000-2010) mainly focusing on the investigation of the extraction methods of OPPs in the environment. In the mid-term research (2011-2018), the main focus was on the hazards of OPPs in the environment and the evaluation of their impact on the environment. In recent years (2019-2022), research hotspots have primarily focused on OPPs residue, environmental detection and efficient removal methods. In the future, it was recommended to intensify research efforts towards identifying OPPs degradation products, assessing their environmental toxicity, exploring compound exposure scenarios, investigating environmental remediation strategies, and advancing the development of new nanomaterials and environmentally friendly pesticide alternatives.

A local outlier factor algorithm based on GeoHash approach (GeoHash-LOF) was proposed to obtain comprehensive and reliable environmental monitoring data. Compared to the traditional LOF algorithm, GeoHash-LOF introduced the concepts of address partitioning and region encoding, significantly reducing computational overhead. Identified outlier data was repaired using Genetic Algorithm-improved Grey Model (GA-GM) prediction technique. By optimizing the background value and initial value in the grey prediction model, the accuracy of prediction was enhanced. Taking the data provided by European Nuclear Energy Agency (ENEA) as an example, the proposed GeoHash-LOF algorithm and GA-GM technique were compared with other algorithms. The results demonstrated that the proposed algorithms exhibited higher efficiency in identifying anomaly data and achieved better fit in missing data restoration.

Phytoplankton and environmental factors are important components of water ecology, but there are currently few studies on the relationship between phytoplankton and environmental impact factors in plateau rivers. Therefore, Tanglang River-Pudu River basin in the Yunnan-Guizhou Plateau was taken as the research object, and the phytoplankton and water bodies in the river basin were sampled and investigated from April to November (dry season, wet season, and level season) in 2022. The diversity index, comprehensive trophic state index, and redundancy analysis (RDA) were used to analyze the water quality of Tanglang River-Pudu River basin and the relationship between phytoplankton and environmental factors, and to explore the characteristics of phytoplankton communities in the basin and their relationship with environmental factors. The results showed that a total of 261 species belonging to 128 genera and 8 phyla of phytoplankton were detected, mainly including Cyanophyta, Chlorophyta and Bacillariophyta. Aphanizomenon flos-aquae was the dominant species throughout the year. The spatial and temporal changes of phytoplankton community structure and diversity were significant. Compared with the dry season and the level season, the cell density in the wet season was less and the biodiversity was higher. The cell density in the mainstream of the Tanglang River was higher than that in other basins. The comprehensive nutritional status index indicated that the whole basin was at the level of medium nutrition to heavy eutrophication, and the eutrophication level was the severest in the mainstream of the Tanglang River . The RDA analysis revealed that different sub-watersheds had different dominant factors influencing the community structure of phytoplankton. For the mainstream of the Tanglang River, the dominant factors were permanganate index (COD_Mn) and pH. For the tributary of the Tanglang River, the dominant factor was COD_Mn. For the mainstream of the Pudu River, the dominant factors were flow (Q) and nitrate nitrogen (${\mathrm{NO}}_3^- $-N). For the tributary of the Pudu River, the dominant factor was water temperature (WT).