Accurately revealing the spatial heterogeneity in the trade-offs and synergies of land use functions(LUFs)and their driving factors is imperative for advancing sustainable land utilization and optimizing land use plan...Accurately revealing the spatial heterogeneity in the trade-offs and synergies of land use functions(LUFs)and their driving factors is imperative for advancing sustainable land utilization and optimizing land use planning.This is especially critical for ecologically vulnerable inland river basins in arid regions.However,existing methods struggle to effectively capture complex nonlinear interactions among environmental factors and their multifaceted relationships with trade-offs and synergies of LUFs,especially for the inland river basins in arid regions.Consequently,this study focused on the middle reaches of the Heihe River Basin(MHRB),an arid inland river basin in northwestern China.Using land use,socioeconomic,meteorological,and hydrological data from 2000 to 2020,we analyzed the spatiotemporal patterns of LUFs and their trade-off and synergy relationships from the perspective of production,living,ecological functions.Additionally,we employed an integrated Extreme Gradient Boosting(XGBoost)-SHapley Additive exPlanations(SHAP)framework to investigate the environmental factors influencing the spatial heterogeneity in the trade-offs and synergies of LUFs.Our findings reveal that from 2000 to 2020,the production,living,and ecological functions of land use within the MHRB exhibited an increasing trend,demonstrating a distinct spatial pattern of''high in the southwest and low in the northeast''.Significant spatial heterogeneity defined the trade-off and synergistic relationships,with trade-offs dominating human activity-intensive oasis areas,while synergies prevailed in other areas.During the study period,synergistic relationships between production and living functions and between production and ecological functions were relatively robust,whereas synergies in living-ecological functions remained weaker.Natural factors(digital elevation model(DEM),annual mean temperature,Normalized Difference Vegetation Index(NDVI),and annual precipitation)emerged as the primary factors driving the trade-offs and synergies of LUFs,followed by socioeconomic factors(population density,Gross Domestic Product(GDP),and land use intensity),while distance factors(distance to water bodies,distance to residential areas,and distance to roads)exerted minimal influence.Notably,the interactions among NDVI,annual mean temperature,DEM,and land use intensity exerted the most substantial impacts on the relationships among LUFs.This study provides novel perspectives and methodologies for unraveling the mechanisms underlying the spatial heterogeneity in the trade-offs and synergies of LUFs,offering scientific insights to inform regional land use planning and sustainable natural resource management in inland river basins in arid regions.展开更多
To identify the root causes of heavy metal contamination in soils as well as prevent and control such contamination from its sources,this study explored the accumulation patterns and ecological risks of heavy metals l...To identify the root causes of heavy metal contamination in soils as well as prevent and control such contamination from its sources,this study explored the accumulation patterns and ecological risks of heavy metals like Cd and Pb in solid waste in mining areas and across the water body,sediment,soil and agricultural product ecosystem surrounding the mining areas.Focusing on the residual solid waste samples in lead-zinc deposits in a certain area of Guizhou Province,along with samples of topsoils,irrigation water,river sediments,and crops from surrounding areas.This study analyzed the distributions of eight heavy metals,i.e.,Cd,As,Cr,Hg,Pb,Zn,Cu,and Ni,in the samples through field surveys and sample tests.Furthermore,this study assessed the contamination levels and ecological risks of heavy metals in soils,sediments,and agricultural products using methods such as the single-factor index,Nemerow composite index,and potential ecological risk assessment.The results indicate that heavy metals in the solid waste samples all exhibited concentrations exceeding their risk screening values,with 60%greater than their risk intervention values.The soils and sediments demonstrate slight and moderate comprehensive ecological risks of heavy metals.The single-factor potential ecological risks of heavy metals in both the soil and sediment samples decreased in the order of Hg,Cd,Pb,As,Cu,Zn,Cr,and Ni,suggesting the same sources of heavy metals in the soils and sediments.Most of the agricultural product samples exhibited over-limit concentrations of heavy metals dominated by Cd,Pb,Ni,and Cr,excluding Hg and As.The agricultural product assessment using the Nemerow composite index reveals that 35%of the agricultural product samples reached the heavy metal contamination level,implying that the agricultural products from farmland around the solid waste dumps have been contaminated with heavy metals.The eight heavy metals in the soil,sediment,and agricultural product samples manifested high coefficients of variation(CVs),indicating pronounced spatial variability.This suggests that their concentrations in soils,sediments,and agricultural products are significantly influenced by human mining activities.Additionally,the agricultural products exhibit strong transport and accumulation capacities for Cd,Cu,and Zn.展开更多
As the main component of electronic products,plastics contain complex and diverse metal additives.Recycling process is not conducive to stable existence of metal additives in electronic plastics.Once the e-waste plast...As the main component of electronic products,plastics contain complex and diverse metal additives.Recycling process is not conducive to stable existence of metal additives in electronic plastics.Once the e-waste plastics enter the environment,they will continue to release harmful metals into environment after aging,causing serious hazards.This study delved into the analysis and comparison of metal content of e-waste plastics,elucidating aging process and metal leaching behavior over a 112-day natural light exposure period.The findings underscored that metal content in recycled plastics surpassed that in their new counterparts.Specifically,Ti content in new plastics remained below 100 mg/kg,while recycled plastics exhibited Ti content surpassing 100 mg/kg threshold.Throughout prolonged natural light exposure,metals such as Zn,Ba and Sb demonstrated a heightened likelihood of release from electronic plastics in comparison to other metals.The aging process during light exposure led to fragmentation of electronic plastics,accompanied by a reduction in particle size.Notably,the particle size reduction was more pronounced in poly acrylonitrile butadiene styrene(ABS)and recycled ABS,experiencing reductions of 40µm and 85µm,respectively.This phenomenon was attributed to the presence of polybutadiene structural units,which proved more susceptible to aging.Along with the breaking of plastics,the ABS plastics released metal species such as Pb,Cd,Ni,Al that had not been detected in other plastics solutions.The collective evidence from this study suggested that ABS and recycled ABS electronic plastics might pose a heightened potential environmental risk compared to other electronic plastics.展开更多
Although the impact of road transport on urban air quality has achieved a high profile in China,still greater attention is required as it has not yet been considered fully even in relation to the road network linking ...Although the impact of road transport on urban air quality has achieved a high profile in China,still greater attention is required as it has not yet been considered fully even in relation to the road network linking cities and urban areas. Strategic environmental assessment (SEA) is a systematic and comprehensive process for evaluating the environmental impacts of a policy,plan or program in publicly accountable decision-making. Air pollution has been recognized as a significant issue in most transport SEA practices. The Strategic Environmental Assessment of the Hubei Road Network Plan (2002-2020) (HRNP) was introduced as one of the World Bank's pilot SEA projects. An effective framework was developed to investigate the functional relationship between the road network and its potential air pollutant emissions. In this study,two indicators were identified:emission intensity/ inventory of pollutants and the spatial distribution of the most polluted areas. Because strategic actions are inherently nebulous and data quality is often disappointing,three alternative scenarios were employed to address uncertainties and data/scale issues. Calculations were made using emission models and results were analyzed with the help of statistical tools and the geographic information system (GIS). The results from the project implementation and the feedback from the World Bank have both shown that the proposed framework is effective in the transport SEA process.展开更多
Taking a polystyrene production project as an example, according to Technical Guidelines for Environmental Risk Assessment of Con- struction Projects （HJ/T169-2004）, we firstly identity the risk of substances and pr...Taking a polystyrene production project as an example, according to Technical Guidelines for Environmental Risk Assessment of Con- struction Projects （HJ/T169-2004）, we firstly identity the risk of substances and production process to determine the major source of danger, and then conduct source analysis and consequence prediction of the maximum credible accident, finally assess the environmental risk of the project and propose main risk management measures. The results reveal that the environmental risk of the project is acceptable, and it is suggested that some dsk prevention and mitigation measures as well as contingency plans should be established.展开更多
Managed open landfill sites can serve as crucial feeding grounds for birds. Studies have demonstrated that garbage dumps offer favorable feeding habitats for various trophic generalist species, including storks and sc...Managed open landfill sites can serve as crucial feeding grounds for birds. Studies have demonstrated that garbage dumps offer favorable feeding habitats for various trophic generalist species, including storks and scavenger raptors. This study aimed to assess bird diversity and abundance in and around Tayba Al Hasanab Landfill, Khartoum. A bird census was conducted using block counts in January 2021. A questionnaire complemented field observations, and interviews were conducted with landfill authorities and waste collectors to gather information on bird availability, numbers, and diversity. During the block counts, 23 bird species were recorded inside and around the landfill. These species directly relied on food resources available at and around the landfill, belonging to 8 orders and 11 families. The four most abundant species foraging at the landfill were Sparrow House (Passer domesticus) with 97 individuals, Black kite (Milvus migrans) with 67 individuals, cattle egret (Bubulcus ibis) with 42 individuals, and Laughing Dove (Spilopelia senegalensis) with 36 individuals. This suggests that these species are the primary exploiters of food resources at the landfill. The results indicate that all species are considered least concerned except the Egyptian Vulture (Neophron percnopterus), which is classified as endangered. Most of the interviewed individuals reported seeing birds in the study area. The study recorded instances of dead birds, such as a white stork colliding and being electrocuted with a transition line observed at different sites along transmission lines near the landfill. Surveys around Tayba landfill need to be conducted to identify deadly power lines for replacement or implement possible mitigation measures on power lines running parallel and close to the Tayba landfills. The avian community foraging at the landfill displayed fluctuations in abundance and interspecific interactions across seasons. Given that the substantial influx of birds to landfills can pose various environmental challenges in urban settings, this study underscores the significance of examining the seasonal dynamics of bird communities concerning the location and management of landfills.展开更多
Phthalic acid esters(PAEs)are a group of compounds widespread in the environment.To investigate the occurrence and accumulation characteristics of PAEs,surface water samples were collected from the Three Gorges Reserv...Phthalic acid esters(PAEs)are a group of compounds widespread in the environment.To investigate the occurrence and accumulation characteristics of PAEs,surface water samples were collected from the Three Gorges Reservoir area,China.The total concentrations of∑_(11)analyzed PAEs(11PAEs)in the collected water samples ranging from 197.7 to 1,409.3 ng/L(mean±IQR:583.1±308.4 ng/L).While DEHP was the most frequently detected PAE,DnBP and DnNP were the most predominant PAEs in the analyzed water samples with a mean contribution of 63.3%of the∑_(11)PAEs.The concentrations of the∑_(11)PAEs in the water samples from the upper reaches of the Yangtze River were significantly higher than those from themiddle reaches.To better understand the transport and fate of the PAEs,seven detected PAEs were modeled by Quantitative Water Air Sediment Interaction(QWASI).The simulated and measured values were close for most PAEs,and differences are within one order of magnitude even for the worst one.For all simulated PAEs,water and particle inflow were main sources in the reservoir,whereas water outflow and degradation in water were important removal pathways.The contribution ratios of different sources/losses varied fromPAEs,depending on their properties.The calculated risk quotients of DnNP in the Three Gorges Reservoir area whether based onmonitoring or simulating results were all far exceeded the safety threshold value,implying the occurrence of this PAE compound may cause potential adverse effects for the aquatic ecology of the Three Gorges Reservoir area.展开更多
Studies on plant diversity are usually based on the total number of species in a community.However,few studies have examined species richness(SR)of different plant life forms in a community along largescale environmen...Studies on plant diversity are usually based on the total number of species in a community.However,few studies have examined species richness(SR)of different plant life forms in a community along largescale environmental gradients.Particularly,the relative importance(RIV)of different plant life forms in a community and how they vary with environmental variables are still unclear.To fill these gaps,we determined plant diversity of ephemeral plants,annual herbs,perennial herbs,and woody plants from 187 sites across drylands in China.The SR patterns of herbaceous plants,especially perennial herbs,and their RIV in plant communities increased with increasing precipitation and soil nutrient content;however,the RIV of annual herbs was not altered along these gradients.The SR and RIV of ephemeral plants were affected mainly by precipitation seasonality.The SR of woody plants had a unimodal relationship with air temperature and exhibited the highest RIV and SR percentage in plant communities under the harshest environments.An obvious shift emerged in plant community composition,SR and their critical impact factors at 238.5 mm of mean annual precipitation(MAP).In mesic regions(>238.5 mm),herbs were the dominant species,and the SR displayed a relatively slow decreasing rate with increasing aridity,which was mediated mainly by MAP and soil nutrients.In arid regions(<238.5 mm),woody plants were the dominant species,and the SR displayed a relatively fast decreasing rate with increasing aridity,which was mediated mainly by climate variables,especially precipitation.Our findings highlight the importance of comparative life form studies in community structure and biodiversity,as their responses to gradients differed substantially on a large scale.展开更多
A distinctive feature of scholarly communities today is exploring topics and concepts in interdisciplinary and international contexts. This observation is increasingly apparent and visible in advancing our thinking an...A distinctive feature of scholarly communities today is exploring topics and concepts in interdisciplinary and international contexts. This observation is increasingly apparent and visible in advancing our thinking and policies related to human/environmental worlds at local, regional, and global scales. Maps are an important part of these innovative and ongoing research approaches. In this context, we consider urban forests a topic meriting more attention of scholars studying the geographic and environmental intersections of the natural sciences with the social sciences and humanities. We construct two innovative knowledge bases, one a conceptual framework based on major themes and concepts related to mapping urban forests using key words of the first 100 results of a Google Scholar query and a second using the number of Google Scholar hyperlinks about mapping urban forests in 244 capital cities. We discovered that the constructed world maps reveal vast global unevenness in our knowledge about urban forests in hyperlink numbers and ratios, results that merit further attention by disciplinary, international and interdisciplinary scholarly communities.展开更多
The limitations of swirl separation in removing microfine oil droplets in water have driven the development of hydrocyclone technology coupled with multiphase or multifield techniques.To enhance microfine oil droplets...The limitations of swirl separation in removing microfine oil droplets in water have driven the development of hydrocyclone technology coupled with multiphase or multifield techniques.To enhance microfine oil droplets separation,a novel hydrocyclone separation coupled with fiber coalescence(HCCFC) was designed.The interaction between fiber balls and oil droplets inside the hydrocyclone,including droplet coalescence and breakage,was investigated.The influence of different operating parameters on separation efficiency was discussed.The results showed that fiber balls promoted oil droplet coalescence when the inlet droplet size(D_(43)) was below 22.37 μm but caused droplet breakage above this threshold.The coalescence performance of HCCFC improved with increasing inlet oil content but declined beyond 450 mg·L^(-1).Separation experiments confirmed that HCCFC outperformed conventional hydrocyclone,with separation efficiency increasing by 2.9% to 20.0%.As the fiber ball content and inlet flow rate increased,the separation efficiency showed a trend of first increasing and then decreasing.Additionally,HCCFC's separation efficiency varied with inlet oil droplet size distribution,showing the most significant enhancement when D_(43) was 22.37 μm,where separation efficiency increased by 14.4%.These findings offer insights into the development and application of multiphase coupled with hydrocyclone technology.展开更多
Wastewater contains various high-risk trace organic pollutants,such as antibiotics and endocrine disruptors,which seriously restrict wastewater reuse.Cyclodextrin-based functional materials show great potential in the...Wastewater contains various high-risk trace organic pollutants,such as antibiotics and endocrine disruptors,which seriously restrict wastewater reuse.Cyclodextrin-based functional materials show great potential in the removal of trace pollutants because of their adsorption catalytic synergy.Clarifying the synergistic mechanism of cyclodextrin in oxidation is the key issue in confined catalytic oxidation process design.In this work,we fabricated a BiOIO_(3)@BiOBr/β-CD heterojunction photocatalyst to study the synergistic mechanism of cyclodextrin in the photocatalytic oxidation process.The synergistic mechanism of cyclodextrin was investigated by combining radical chemistry,electrochemistry,spectroscopy,and timedependent density functional theory.Results showed that the excited intermediate free radicals played an important role in promoting the photocatalytic degradation process.The heterojunction photocatalyst loaded withβ-cyclodextrin(β-CD)at the electronic end(C[Cat.]=0.2mg/mL)removed about 97%of bisphenol A(BPA)within 30min,and the first-order kinetic constant(k_(CDBIB)=0.112 min^(−1))was about twice that of the unloadedβ-CD(k_(BIB)=0.057 min^(−1)).Cyclodextrin loading improved the photocatalytic performance of the heterojunction and stimulated the intermediate to increase the free radical yield and regulate the reaction path.展开更多
In this study,a Fe,N-decorated carbocatalyst(FeCN@X)based on Fe-MOFs was synthesized to activate peroxydisulfate(PDS)for removing sulfadiazine(SDZ)from water.The surface morphology and structure of FeCN@X was characte...In this study,a Fe,N-decorated carbocatalyst(FeCN@X)based on Fe-MOFs was synthesized to activate peroxydisulfate(PDS)for removing sulfadiazine(SDZ)from water.The surface morphology and structure of FeCN@X was characterized by scanning electron microscopy,X-ray diffraction,and X-ray photoelectron spec troscopy.FeCN@1000,formed at the pyrolysis temperature of 1000℃,exhibited the best catalytic performance for degrade SDZ in the presence of 0.15 g·L^(-1)catalyst and 0.5 mmol·L^(-1)PDS,and the reaction conversion rate was 0.199 L·mmol^(-1).Moreover,the effects of experimental conditions,coexisting anions and fulvic acid on catalytic performance of FeCN@1000 were investigated.The excellent potential of FeCN@1000 as a PDS activator in environmental applications was also suggested by the results of its reusability and adaptability experiments.The result of XPS,ROS quenching,EPR and electrochemical experiments showed the degradation of SDZ was primarily driven by an electron transfer process(ETP).Furthermore,Fe(Ⅲ)instead of Fe(Ⅱ)plays a major role in ETP,as Fe(Ⅲ)sites can interact with PDS and form the low-spin surface complexes(Fe(Ⅲ)/CN-PDS).Meanwhile,the small number of~1O_(2) and O_(2)~-·generated by the activation of PDS will promote the system degradation of SDZ activity by accelerating the conversion of Fe(Ⅱ)to Fe(Ⅲ).This study provides new insights for the design of novel PDS activator for efficient degradation of emerging pollutants by ETP.展开更多
Carbon dioxide photocatalytic reduction (CO_(2)-PR) is an efficient method for controlling CO_(2)emissions and generating cleaner energy while mitigating global warming.Tungsten oxides (WxOy) have attracted considerab...Carbon dioxide photocatalytic reduction (CO_(2)-PR) is an efficient method for controlling CO_(2)emissions and generating cleaner energy while mitigating global warming.Tungsten oxides (WxOy) have attracted considerable attention for CO_(2)-PR due to their excellent spectral absorbance.However,comprehensive reviews are lacking on the use of WxOyfor CO_(2)-PR.Therefore,this review provides a detailed summary of t research progress made with WxOy-based catalysts in CO_(2)-PR.It also explains the fundamental principles of CO_(2)-PR and evaluates key performance indicators that affect the activity of WxOy-based photocatalysts,including yield,selectivity,stability,and apparent quantum yield.Additionally,this review explores opportunities for synthesizing high-performance WxOy-based photocatalysts and highlights their potential for the green preparation of C1/C2 products through CO_(2)-PR.These innovative strategies aim to address the challenges and pressures associated with energy and environmental issues,particularly by enhancing artificial photosynthesis efficiency.展开更多
Developing efficient photocatalysts to address collaborative energy and environmental crises still faces significant challenges.In this report,we present a highly efficient MXene–based photocatalyst,which is combined...Developing efficient photocatalysts to address collaborative energy and environmental crises still faces significant challenges.In this report,we present a highly efficient MXene–based photocatalyst,which is combined with MoS_(2)nano patches and TiO_(2)/Ti_(3)C_(2)(TTC)nanowires through hydrothermal treatment.Of all the composites tested,the optimized photocatalyst gave a remarkable H_(2)and revolving polylactic acid(PLA)into pyruvic acid(PA).Achieving a remarkable H_(2)evolution rate of 637.1 and 243.2μmol g^(−1)h^(−1),in the presence of TEOA and PLA as a sacrificial reagent under UV-vis(λ≥365 nm)light irradiation.The improved photocatalytic activity is a result of the combination of dual cocatalyst on the surface of TTC photocatalyst,which create an ideal synergistic effect for the generation of PA and the production of H_(2)simultaneously.The MoS_(2)TiO_(2)/Ti_(3)C_(2)(MTT)composite can generate more photoexcited charge carriers,leading to the generation of more active radicals,which may enhance the system's photocatalytic activity.This work aims at demonstrating its future significance and guide the scientific community towards a more efficient approach to commercializing H_(2)through photocatalysis.展开更多
Heavy metal contamination of soils through anthropogenic activities is a widespread and serious problem confronting scientists and regulators throughout the world. In this study we investigated the distribution, chemi...Heavy metal contamination of soils through anthropogenic activities is a widespread and serious problem confronting scientists and regulators throughout the world. In this study we investigated the distribution, chemical species and availability of lead, zinc, cadmium and copper in nine surface（0 to 20 cm） soils from near an abandoned lead/zinc mine tailings located in Shaoxing, Zhejiang, China. Total heavy metal contents ranged from 5271 to 16369 mg/kg for Pb, 387 to 1221 mg/kg for Zn, 3.0 to 9.3 mg/kg for Cd and 65 to 206 mg/kg for Cu. In general, all heavy metals exceeded China National Standards for Soil Environmental Quality of Heavy Metals by a factor of 3-65 times. Comparison of the heavy metal concentrations（Pb, Zn, Cd and Cu） with clay content revealed a strongly significant relationship while significant relationship（ P 〈 0.001 ） was also obtained between Cd ＋ Zn and Pb ＋ Cu. Solid phase speciation of the soils using Tessier procedure showed that the heavy metals were distributed in the order： residual 〉〉 organically complexed-Fe-Mn oxides occluded 〉 carbonate bound 〉 exchangeable 〉 water soluble. In the organic matter fraction, the ratio of Pb（29.1% ） to its total concentration in the soils was higher than those of Zn（4.70% ）, Cd（3.16% ） and Cu（9.50% ）. The percentages of the water soluble and the exchangeable fractions of Pb（1.80% ） and Cd（2.74% ） were markedly greater than those of Zn（0.10% ） and Cu（0.15% ）, suggesting that Pb and Cd are relatively more mobile and hence more toxic in the contaminated soils. Strongly significant relationships between H20-Pb, H20-Zn and H20-Cu, strong positive correlations between H20-Pb, H20-Zn, H20-Cu and organic matter in soil were found. The content of H20-Pb, H20-Zn, H20-Cu was negatively correlated with pH values. The similar negative relationships between pH values and exchangeable heavy metals were also recorded. It is suggested that increasing soil pH or liming the soil could decrease bioavailability of heavy metals in the soil.展开更多
Food consumption is one of the key exposure routes of humans to contaminants. This article evaluated the residue levels of 51 pesticides and 16 polychlorinated biphenyls （PCBs） in selected fish and food items which ...Food consumption is one of the key exposure routes of humans to contaminants. This article evaluated the residue levels of 51 pesticides and 16 polychlorinated biphenyls （PCBs） in selected fish and food items which were commonly consumed in the Nantong area of Jiangsu Province, Southeast China. The 51 pesticides and 16 PCBs were analyzed by highly sensitive gas chromatography- tandem mass spectrometry （GC-MS/MS）. The results showed that organochlorine pesticides such as dichlorodiphenyltrichloroethanes （DDTs）, hexachlorocyclohexanes （I-ICHs）, hexachlorobenzene （HCB） and mirex and other pesticides including chlorpyrifos, pyrethroid pesticides, metolachlor, pyridaben and trifluralin were frequently detected in the samples, which was consistent with the accumulation level and characteristics of these toxic chemicals in human adipose tissue of people living in Nantong. Meanwhile, correlation of the residue level of toxic chemicals with their physical chemical properties and historic use pattern in Nantong area was observed. Combined with dietary survey results at the same sampling locations, human health risk assessment of ingestion through the dietary route was performed. The results suggested that the non-cancer risks of the chemicals investigated can be considered negligible in the Nantong area, however, the cancer risks from lifetime dietary exposure to DDTs and HCB have exceeded the acceptable levels.展开更多
The contamination and environmental risk assessment of the toxic elements in sediments from the middle-downstream (Zhuzhou-Changsha section) of the Xiangjiang River in Hunan Province of China were studied. The results...The contamination and environmental risk assessment of the toxic elements in sediments from the middle-downstream (Zhuzhou-Changsha section) of the Xiangjiang River in Hunan Province of China were studied. The results show that As, Cd, Pb and Zn are major contaminants in sediments, and average concentrations of these elements significantly exceed both the Control Standards for Pollutants in Sludge of China (GB4284-84) for agricultural use in acidic soils and the effect range median (ERM) values. The average concentrations of As, Cd and Pb in the river water slightly exceed the limit of Surface Water Environment Quality Standard (GB3838-2002). The concentrations of As and Cr in depth profiles extensively change, but slight changes are observed in Pb and Zn. Cd and Zn in most sediment samples can easily enter the food-chain and bring possible ecotoxicological risk to organisms living in sediments according to the risk assessment code.展开更多
Toxicity studies considering both the bare and stabilized forms of zero valent iron nanoparticles（nZVI） could be timely, given that ecological risks identified are minimized through modification or with substitution...Toxicity studies considering both the bare and stabilized forms of zero valent iron nanoparticles（nZVI） could be timely, given that ecological risks identified are minimized through modification or with substitution of approaches in the synthesis, development and environmental application of the nanoparticles before succeeding to volume production.This review is focused on the fate, transport and toxicological implications of the bare nZVI and surface modified particles used for environmental applications.展开更多
基金funded by the University Teachers Innovation Fund Project of Gansu Province(2025A-001)the Northwest Normal University Young Teachers'Scientific Research Ability Improvement Plan(NWNULKQN2024-20).
文摘Accurately revealing the spatial heterogeneity in the trade-offs and synergies of land use functions(LUFs)and their driving factors is imperative for advancing sustainable land utilization and optimizing land use planning.This is especially critical for ecologically vulnerable inland river basins in arid regions.However,existing methods struggle to effectively capture complex nonlinear interactions among environmental factors and their multifaceted relationships with trade-offs and synergies of LUFs,especially for the inland river basins in arid regions.Consequently,this study focused on the middle reaches of the Heihe River Basin(MHRB),an arid inland river basin in northwestern China.Using land use,socioeconomic,meteorological,and hydrological data from 2000 to 2020,we analyzed the spatiotemporal patterns of LUFs and their trade-off and synergy relationships from the perspective of production,living,ecological functions.Additionally,we employed an integrated Extreme Gradient Boosting(XGBoost)-SHapley Additive exPlanations(SHAP)framework to investigate the environmental factors influencing the spatial heterogeneity in the trade-offs and synergies of LUFs.Our findings reveal that from 2000 to 2020,the production,living,and ecological functions of land use within the MHRB exhibited an increasing trend,demonstrating a distinct spatial pattern of''high in the southwest and low in the northeast''.Significant spatial heterogeneity defined the trade-off and synergistic relationships,with trade-offs dominating human activity-intensive oasis areas,while synergies prevailed in other areas.During the study period,synergistic relationships between production and living functions and between production and ecological functions were relatively robust,whereas synergies in living-ecological functions remained weaker.Natural factors(digital elevation model(DEM),annual mean temperature,Normalized Difference Vegetation Index(NDVI),and annual precipitation)emerged as the primary factors driving the trade-offs and synergies of LUFs,followed by socioeconomic factors(population density,Gross Domestic Product(GDP),and land use intensity),while distance factors(distance to water bodies,distance to residential areas,and distance to roads)exerted minimal influence.Notably,the interactions among NDVI,annual mean temperature,DEM,and land use intensity exerted the most substantial impacts on the relationships among LUFs.This study provides novel perspectives and methodologies for unraveling the mechanisms underlying the spatial heterogeneity in the trade-offs and synergies of LUFs,offering scientific insights to inform regional land use planning and sustainable natural resource management in inland river basins in arid regions.
文摘To identify the root causes of heavy metal contamination in soils as well as prevent and control such contamination from its sources,this study explored the accumulation patterns and ecological risks of heavy metals like Cd and Pb in solid waste in mining areas and across the water body,sediment,soil and agricultural product ecosystem surrounding the mining areas.Focusing on the residual solid waste samples in lead-zinc deposits in a certain area of Guizhou Province,along with samples of topsoils,irrigation water,river sediments,and crops from surrounding areas.This study analyzed the distributions of eight heavy metals,i.e.,Cd,As,Cr,Hg,Pb,Zn,Cu,and Ni,in the samples through field surveys and sample tests.Furthermore,this study assessed the contamination levels and ecological risks of heavy metals in soils,sediments,and agricultural products using methods such as the single-factor index,Nemerow composite index,and potential ecological risk assessment.The results indicate that heavy metals in the solid waste samples all exhibited concentrations exceeding their risk screening values,with 60%greater than their risk intervention values.The soils and sediments demonstrate slight and moderate comprehensive ecological risks of heavy metals.The single-factor potential ecological risks of heavy metals in both the soil and sediment samples decreased in the order of Hg,Cd,Pb,As,Cu,Zn,Cr,and Ni,suggesting the same sources of heavy metals in the soils and sediments.Most of the agricultural product samples exhibited over-limit concentrations of heavy metals dominated by Cd,Pb,Ni,and Cr,excluding Hg and As.The agricultural product assessment using the Nemerow composite index reveals that 35%of the agricultural product samples reached the heavy metal contamination level,implying that the agricultural products from farmland around the solid waste dumps have been contaminated with heavy metals.The eight heavy metals in the soil,sediment,and agricultural product samples manifested high coefficients of variation(CVs),indicating pronounced spatial variability.This suggests that their concentrations in soils,sediments,and agricultural products are significantly influenced by human mining activities.Additionally,the agricultural products exhibit strong transport and accumulation capacities for Cd,Cu,and Zn.
基金the Natural Science Foundation of Guangdong Province(No.2021B1515020041)the National Natural Science Foundation of China(No.42277403)+4 种基金the Projects of International Cooperation and Exchange of the National Natural Science Foundation of China(NSFC-UNEP)(No:32261143459)the Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control(No.2023B1212060002)the Guangdong Major Project of Basic and Applied Basic Research(No.2023B0303000024)the High-level University Special Fund(No.G03050K001)the Research Projects of the General Administration of Customs(No.2022HK060)for financial support.
文摘As the main component of electronic products,plastics contain complex and diverse metal additives.Recycling process is not conducive to stable existence of metal additives in electronic plastics.Once the e-waste plastics enter the environment,they will continue to release harmful metals into environment after aging,causing serious hazards.This study delved into the analysis and comparison of metal content of e-waste plastics,elucidating aging process and metal leaching behavior over a 112-day natural light exposure period.The findings underscored that metal content in recycled plastics surpassed that in their new counterparts.Specifically,Ti content in new plastics remained below 100 mg/kg,while recycled plastics exhibited Ti content surpassing 100 mg/kg threshold.Throughout prolonged natural light exposure,metals such as Zn,Ba and Sb demonstrated a heightened likelihood of release from electronic plastics in comparison to other metals.The aging process during light exposure led to fragmentation of electronic plastics,accompanied by a reduction in particle size.Notably,the particle size reduction was more pronounced in poly acrylonitrile butadiene styrene(ABS)and recycled ABS,experiencing reductions of 40µm and 85µm,respectively.This phenomenon was attributed to the presence of polybutadiene structural units,which proved more susceptible to aging.Along with the breaking of plastics,the ABS plastics released metal species such as Pb,Cd,Ni,Al that had not been detected in other plastics solutions.The collective evidence from this study suggested that ABS and recycled ABS electronic plastics might pose a heightened potential environmental risk compared to other electronic plastics.
基金Project supported by the Environment Department of the World Bank, and the National Project 985: Circular Economy Innovational Platform in Nankai University, China
文摘Although the impact of road transport on urban air quality has achieved a high profile in China,still greater attention is required as it has not yet been considered fully even in relation to the road network linking cities and urban areas. Strategic environmental assessment (SEA) is a systematic and comprehensive process for evaluating the environmental impacts of a policy,plan or program in publicly accountable decision-making. Air pollution has been recognized as a significant issue in most transport SEA practices. The Strategic Environmental Assessment of the Hubei Road Network Plan (2002-2020) (HRNP) was introduced as one of the World Bank's pilot SEA projects. An effective framework was developed to investigate the functional relationship between the road network and its potential air pollutant emissions. In this study,two indicators were identified:emission intensity/ inventory of pollutants and the spatial distribution of the most polluted areas. Because strategic actions are inherently nebulous and data quality is often disappointing,three alternative scenarios were employed to address uncertainties and data/scale issues. Calculations were made using emission models and results were analyzed with the help of statistical tools and the geographic information system (GIS). The results from the project implementation and the feedback from the World Bank have both shown that the proposed framework is effective in the transport SEA process.
文摘Taking a polystyrene production project as an example, according to Technical Guidelines for Environmental Risk Assessment of Con- struction Projects （HJ/T169-2004）, we firstly identity the risk of substances and production process to determine the major source of danger, and then conduct source analysis and consequence prediction of the maximum credible accident, finally assess the environmental risk of the project and propose main risk management measures. The results reveal that the environmental risk of the project is acceptable, and it is suggested that some dsk prevention and mitigation measures as well as contingency plans should be established.
文摘Managed open landfill sites can serve as crucial feeding grounds for birds. Studies have demonstrated that garbage dumps offer favorable feeding habitats for various trophic generalist species, including storks and scavenger raptors. This study aimed to assess bird diversity and abundance in and around Tayba Al Hasanab Landfill, Khartoum. A bird census was conducted using block counts in January 2021. A questionnaire complemented field observations, and interviews were conducted with landfill authorities and waste collectors to gather information on bird availability, numbers, and diversity. During the block counts, 23 bird species were recorded inside and around the landfill. These species directly relied on food resources available at and around the landfill, belonging to 8 orders and 11 families. The four most abundant species foraging at the landfill were Sparrow House (Passer domesticus) with 97 individuals, Black kite (Milvus migrans) with 67 individuals, cattle egret (Bubulcus ibis) with 42 individuals, and Laughing Dove (Spilopelia senegalensis) with 36 individuals. This suggests that these species are the primary exploiters of food resources at the landfill. The results indicate that all species are considered least concerned except the Egyptian Vulture (Neophron percnopterus), which is classified as endangered. Most of the interviewed individuals reported seeing birds in the study area. The study recorded instances of dead birds, such as a white stork colliding and being electrocuted with a transition line observed at different sites along transmission lines near the landfill. Surveys around Tayba landfill need to be conducted to identify deadly power lines for replacement or implement possible mitigation measures on power lines running parallel and close to the Tayba landfills. The avian community foraging at the landfill displayed fluctuations in abundance and interspecific interactions across seasons. Given that the substantial influx of birds to landfills can pose various environmental challenges in urban settings, this study underscores the significance of examining the seasonal dynamics of bird communities concerning the location and management of landfills.
基金supported by the Innovation Fund of Nanjing Institute of Environmental Science,Ministry of Ecology and Environment,China(No.ZX2023QT003)the National Natural Science Foundation of China(No.22306130)+1 种基金Jiangsu Funding Program for Excellent Postdoctoral Talent(No.2022ZB789)the Ecological Environment Research Project of Jiangsu Province,China(No.2022014).
文摘Phthalic acid esters(PAEs)are a group of compounds widespread in the environment.To investigate the occurrence and accumulation characteristics of PAEs,surface water samples were collected from the Three Gorges Reservoir area,China.The total concentrations of∑_(11)analyzed PAEs(11PAEs)in the collected water samples ranging from 197.7 to 1,409.3 ng/L(mean±IQR:583.1±308.4 ng/L).While DEHP was the most frequently detected PAE,DnBP and DnNP were the most predominant PAEs in the analyzed water samples with a mean contribution of 63.3%of the∑_(11)PAEs.The concentrations of the∑_(11)PAEs in the water samples from the upper reaches of the Yangtze River were significantly higher than those from themiddle reaches.To better understand the transport and fate of the PAEs,seven detected PAEs were modeled by Quantitative Water Air Sediment Interaction(QWASI).The simulated and measured values were close for most PAEs,and differences are within one order of magnitude even for the worst one.For all simulated PAEs,water and particle inflow were main sources in the reservoir,whereas water outflow and degradation in water were important removal pathways.The contribution ratios of different sources/losses varied fromPAEs,depending on their properties.The calculated risk quotients of DnNP in the Three Gorges Reservoir area whether based onmonitoring or simulating results were all far exceeded the safety threshold value,implying the occurrence of this PAE compound may cause potential adverse effects for the aquatic ecology of the Three Gorges Reservoir area.
基金supported by the National Key Research and Development Program of China(2023YFF0805602)National Natural Science Foundation of China(32225032,32001192,32271597)+1 种基金the Innovation Base Project of Gansu Province(2021YFF0703904)the Science and Technology Program of Gansu Province(24JRRA515,22JR5RA525,23JRRA1157).
文摘Studies on plant diversity are usually based on the total number of species in a community.However,few studies have examined species richness(SR)of different plant life forms in a community along largescale environmental gradients.Particularly,the relative importance(RIV)of different plant life forms in a community and how they vary with environmental variables are still unclear.To fill these gaps,we determined plant diversity of ephemeral plants,annual herbs,perennial herbs,and woody plants from 187 sites across drylands in China.The SR patterns of herbaceous plants,especially perennial herbs,and their RIV in plant communities increased with increasing precipitation and soil nutrient content;however,the RIV of annual herbs was not altered along these gradients.The SR and RIV of ephemeral plants were affected mainly by precipitation seasonality.The SR of woody plants had a unimodal relationship with air temperature and exhibited the highest RIV and SR percentage in plant communities under the harshest environments.An obvious shift emerged in plant community composition,SR and their critical impact factors at 238.5 mm of mean annual precipitation(MAP).In mesic regions(>238.5 mm),herbs were the dominant species,and the SR displayed a relatively slow decreasing rate with increasing aridity,which was mediated mainly by MAP and soil nutrients.In arid regions(<238.5 mm),woody plants were the dominant species,and the SR displayed a relatively fast decreasing rate with increasing aridity,which was mediated mainly by climate variables,especially precipitation.Our findings highlight the importance of comparative life form studies in community structure and biodiversity,as their responses to gradients differed substantially on a large scale.
文摘A distinctive feature of scholarly communities today is exploring topics and concepts in interdisciplinary and international contexts. This observation is increasingly apparent and visible in advancing our thinking and policies related to human/environmental worlds at local, regional, and global scales. Maps are an important part of these innovative and ongoing research approaches. In this context, we consider urban forests a topic meriting more attention of scholars studying the geographic and environmental intersections of the natural sciences with the social sciences and humanities. We construct two innovative knowledge bases, one a conceptual framework based on major themes and concepts related to mapping urban forests using key words of the first 100 results of a Google Scholar query and a second using the number of Google Scholar hyperlinks about mapping urban forests in 244 capital cities. We discovered that the constructed world maps reveal vast global unevenness in our knowledge about urban forests in hyperlink numbers and ratios, results that merit further attention by disciplinary, international and interdisciplinary scholarly communities.
基金sponsored by the National Science Fund for Distinguished Young Scholars,China(22225804)the National Natural Science Foundation of China(22078102,22408101,22308105)。
文摘The limitations of swirl separation in removing microfine oil droplets in water have driven the development of hydrocyclone technology coupled with multiphase or multifield techniques.To enhance microfine oil droplets separation,a novel hydrocyclone separation coupled with fiber coalescence(HCCFC) was designed.The interaction between fiber balls and oil droplets inside the hydrocyclone,including droplet coalescence and breakage,was investigated.The influence of different operating parameters on separation efficiency was discussed.The results showed that fiber balls promoted oil droplet coalescence when the inlet droplet size(D_(43)) was below 22.37 μm but caused droplet breakage above this threshold.The coalescence performance of HCCFC improved with increasing inlet oil content but declined beyond 450 mg·L^(-1).Separation experiments confirmed that HCCFC outperformed conventional hydrocyclone,with separation efficiency increasing by 2.9% to 20.0%.As the fiber ball content and inlet flow rate increased,the separation efficiency showed a trend of first increasing and then decreasing.Additionally,HCCFC's separation efficiency varied with inlet oil droplet size distribution,showing the most significant enhancement when D_(43) was 22.37 μm,where separation efficiency increased by 14.4%.These findings offer insights into the development and application of multiphase coupled with hydrocyclone technology.
基金supported by Program of Shanghai Outstanding Technology Leaders(No.20XD1433900)the National Natural Science Foundation of China(No.52370168).
文摘Wastewater contains various high-risk trace organic pollutants,such as antibiotics and endocrine disruptors,which seriously restrict wastewater reuse.Cyclodextrin-based functional materials show great potential in the removal of trace pollutants because of their adsorption catalytic synergy.Clarifying the synergistic mechanism of cyclodextrin in oxidation is the key issue in confined catalytic oxidation process design.In this work,we fabricated a BiOIO_(3)@BiOBr/β-CD heterojunction photocatalyst to study the synergistic mechanism of cyclodextrin in the photocatalytic oxidation process.The synergistic mechanism of cyclodextrin was investigated by combining radical chemistry,electrochemistry,spectroscopy,and timedependent density functional theory.Results showed that the excited intermediate free radicals played an important role in promoting the photocatalytic degradation process.The heterojunction photocatalyst loaded withβ-cyclodextrin(β-CD)at the electronic end(C[Cat.]=0.2mg/mL)removed about 97%of bisphenol A(BPA)within 30min,and the first-order kinetic constant(k_(CDBIB)=0.112 min^(−1))was about twice that of the unloadedβ-CD(k_(BIB)=0.057 min^(−1)).Cyclodextrin loading improved the photocatalytic performance of the heterojunction and stimulated the intermediate to increase the free radical yield and regulate the reaction path.
基金supported by Key Research and Development Projects of Shanghai Municipal Commission of Science and Technology(20dz1204000)。
文摘In this study,a Fe,N-decorated carbocatalyst(FeCN@X)based on Fe-MOFs was synthesized to activate peroxydisulfate(PDS)for removing sulfadiazine(SDZ)from water.The surface morphology and structure of FeCN@X was characterized by scanning electron microscopy,X-ray diffraction,and X-ray photoelectron spec troscopy.FeCN@1000,formed at the pyrolysis temperature of 1000℃,exhibited the best catalytic performance for degrade SDZ in the presence of 0.15 g·L^(-1)catalyst and 0.5 mmol·L^(-1)PDS,and the reaction conversion rate was 0.199 L·mmol^(-1).Moreover,the effects of experimental conditions,coexisting anions and fulvic acid on catalytic performance of FeCN@1000 were investigated.The excellent potential of FeCN@1000 as a PDS activator in environmental applications was also suggested by the results of its reusability and adaptability experiments.The result of XPS,ROS quenching,EPR and electrochemical experiments showed the degradation of SDZ was primarily driven by an electron transfer process(ETP).Furthermore,Fe(Ⅲ)instead of Fe(Ⅱ)plays a major role in ETP,as Fe(Ⅲ)sites can interact with PDS and form the low-spin surface complexes(Fe(Ⅲ)/CN-PDS).Meanwhile,the small number of~1O_(2) and O_(2)~-·generated by the activation of PDS will promote the system degradation of SDZ activity by accelerating the conversion of Fe(Ⅱ)to Fe(Ⅲ).This study provides new insights for the design of novel PDS activator for efficient degradation of emerging pollutants by ETP.
基金supported by the National Natural Science Foundation of China(No.22376065)the Science and Technology Commission of Shanghai Municipality(No.22ZR1418600)Shanghai Municipal Science and Technology(No.20DZ2250400)。
文摘Carbon dioxide photocatalytic reduction (CO_(2)-PR) is an efficient method for controlling CO_(2)emissions and generating cleaner energy while mitigating global warming.Tungsten oxides (WxOy) have attracted considerable attention for CO_(2)-PR due to their excellent spectral absorbance.However,comprehensive reviews are lacking on the use of WxOyfor CO_(2)-PR.Therefore,this review provides a detailed summary of t research progress made with WxOy-based catalysts in CO_(2)-PR.It also explains the fundamental principles of CO_(2)-PR and evaluates key performance indicators that affect the activity of WxOy-based photocatalysts,including yield,selectivity,stability,and apparent quantum yield.Additionally,this review explores opportunities for synthesizing high-performance WxOy-based photocatalysts and highlights their potential for the green preparation of C1/C2 products through CO_(2)-PR.These innovative strategies aim to address the challenges and pressures associated with energy and environmental issues,particularly by enhancing artificial photosynthesis efficiency.
文摘Developing efficient photocatalysts to address collaborative energy and environmental crises still faces significant challenges.In this report,we present a highly efficient MXene–based photocatalyst,which is combined with MoS_(2)nano patches and TiO_(2)/Ti_(3)C_(2)(TTC)nanowires through hydrothermal treatment.Of all the composites tested,the optimized photocatalyst gave a remarkable H_(2)and revolving polylactic acid(PLA)into pyruvic acid(PA).Achieving a remarkable H_(2)evolution rate of 637.1 and 243.2μmol g^(−1)h^(−1),in the presence of TEOA and PLA as a sacrificial reagent under UV-vis(λ≥365 nm)light irradiation.The improved photocatalytic activity is a result of the combination of dual cocatalyst on the surface of TTC photocatalyst,which create an ideal synergistic effect for the generation of PA and the production of H_(2)simultaneously.The MoS_(2)TiO_(2)/Ti_(3)C_(2)(MTT)composite can generate more photoexcited charge carriers,leading to the generation of more active radicals,which may enhance the system's photocatalytic activity.This work aims at demonstrating its future significance and guide the scientific community towards a more efficient approach to commercializing H_(2)through photocatalysis.
文摘Heavy metal contamination of soils through anthropogenic activities is a widespread and serious problem confronting scientists and regulators throughout the world. In this study we investigated the distribution, chemical species and availability of lead, zinc, cadmium and copper in nine surface（0 to 20 cm） soils from near an abandoned lead/zinc mine tailings located in Shaoxing, Zhejiang, China. Total heavy metal contents ranged from 5271 to 16369 mg/kg for Pb, 387 to 1221 mg/kg for Zn, 3.0 to 9.3 mg/kg for Cd and 65 to 206 mg/kg for Cu. In general, all heavy metals exceeded China National Standards for Soil Environmental Quality of Heavy Metals by a factor of 3-65 times. Comparison of the heavy metal concentrations（Pb, Zn, Cd and Cu） with clay content revealed a strongly significant relationship while significant relationship（ P 〈 0.001 ） was also obtained between Cd ＋ Zn and Pb ＋ Cu. Solid phase speciation of the soils using Tessier procedure showed that the heavy metals were distributed in the order： residual 〉〉 organically complexed-Fe-Mn oxides occluded 〉 carbonate bound 〉 exchangeable 〉 water soluble. In the organic matter fraction, the ratio of Pb（29.1% ） to its total concentration in the soils was higher than those of Zn（4.70% ）, Cd（3.16% ） and Cu（9.50% ）. The percentages of the water soluble and the exchangeable fractions of Pb（1.80% ） and Cd（2.74% ） were markedly greater than those of Zn（0.10% ） and Cu（0.15% ）, suggesting that Pb and Cd are relatively more mobile and hence more toxic in the contaminated soils. Strongly significant relationships between H20-Pb, H20-Zn and H20-Cu, strong positive correlations between H20-Pb, H20-Zn, H20-Cu and organic matter in soil were found. The content of H20-Pb, H20-Zn, H20-Cu was negatively correlated with pH values. The similar negative relationships between pH values and exchangeable heavy metals were also recorded. It is suggested that increasing soil pH or liming the soil could decrease bioavailability of heavy metals in the soil.
基金supported by the 2008 Commonwealand Environmental protection Project of the Ministry of Environmental Protection of the People’s Republic of China (MEP) (No. 200809102)"333 High-level Talent Cultivation Project" research funding of Jiangsu Province-"Research on human health risk assessment of pesticides"
文摘Food consumption is one of the key exposure routes of humans to contaminants. This article evaluated the residue levels of 51 pesticides and 16 polychlorinated biphenyls （PCBs） in selected fish and food items which were commonly consumed in the Nantong area of Jiangsu Province, Southeast China. The 51 pesticides and 16 PCBs were analyzed by highly sensitive gas chromatography- tandem mass spectrometry （GC-MS/MS）. The results showed that organochlorine pesticides such as dichlorodiphenyltrichloroethanes （DDTs）, hexachlorocyclohexanes （I-ICHs）, hexachlorobenzene （HCB） and mirex and other pesticides including chlorpyrifos, pyrethroid pesticides, metolachlor, pyridaben and trifluralin were frequently detected in the samples, which was consistent with the accumulation level and characteristics of these toxic chemicals in human adipose tissue of people living in Nantong. Meanwhile, correlation of the residue level of toxic chemicals with their physical chemical properties and historic use pattern in Nantong area was observed. Combined with dietary survey results at the same sampling locations, human health risk assessment of ingestion through the dietary route was performed. The results suggested that the non-cancer risks of the chemicals investigated can be considered negligible in the Nantong area, however, the cancer risks from lifetime dietary exposure to DDTs and HCB have exceeded the acceptable levels.
基金Project (20507022) supported by the National Natural Science Foundation of ChinaProject (EREH050303) supported by the Foundation of Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health
文摘The contamination and environmental risk assessment of the toxic elements in sediments from the middle-downstream (Zhuzhou-Changsha section) of the Xiangjiang River in Hunan Province of China were studied. The results show that As, Cd, Pb and Zn are major contaminants in sediments, and average concentrations of these elements significantly exceed both the Control Standards for Pollutants in Sludge of China (GB4284-84) for agricultural use in acidic soils and the effect range median (ERM) values. The average concentrations of As, Cd and Pb in the river water slightly exceed the limit of Surface Water Environment Quality Standard (GB3838-2002). The concentrations of As and Cr in depth profiles extensively change, but slight changes are observed in Pb and Zn. Cd and Zn in most sediment samples can easily enter the food-chain and bring possible ecotoxicological risk to organisms living in sediments according to the risk assessment code.
文摘Toxicity studies considering both the bare and stabilized forms of zero valent iron nanoparticles（nZVI） could be timely, given that ecological risks identified are minimized through modification or with substitution of approaches in the synthesis, development and environmental application of the nanoparticles before succeeding to volume production.This review is focused on the fate, transport and toxicological implications of the bare nZVI and surface modified particles used for environmental applications.
