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Estimation of suspended sediment concentration based on bio-optical mechanism and HJ-1 image in Chaohu Lake

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Science china.Earth Sciences 2010年第S1期53卷 58-66页

作者： WANG Qiao1,2,JIN Xin2,LI YunMei2,WU ChuanQing1,Lü heng2,WANG YanFei2,ZHANG Hong2,YIN Bin2 & zhu Li1 1Satellite Environment Center,ministry of {3. Protection,beijing 100029,china.2key laboratory of Virtual Geographic Environment of education ministry,Nanjing Normal university,Nanjing 210046,china 1. Satellite Environment Center Ministry of Environmental Protection Beijing 100029 China2. Key Laboratory of Virtual Geographic Environment of Education Ministry Nanjing Normal University Nanjing 210046 China

Synchronization experiment was conducted in June,2009 to get Inherent Optical Properties(IOP) of water component in Chaohu *** bio-optical mechanism was studied combined with multispectral data of environmental Satellite 1(CCD),and then inversion models of total suspended matter(TSM),inorganic suspended matter(ISM) and organic suspended matter(OSM) concentration were *** data indicated that:the absorption ratio of suspended particulate matter and CDOM to total were almost no change from band 1 to band 2 with about 85% and 9%,*** ratio of pure water to total increased from 0.4% to 5.6%.water reflectance in these two bands were influenced by absorption of three kinds of components:algae particles absorption surpassed non-algal particles in band 3.and so played an important role in total absorption with about 3..7%;the proportion of pure water absorption and particles matter backscattering both were 99% in band 4,so these two components decided the main inherent optical properties in band *** models of TSM and ISM concentration inversion based on band combination(band 3.+ band 4)/(band 1 + band 2) were built,while OSM concentration was estimated by band 4/(band 1 + band 2) *** by image data,RE of TSM concentration between modeled and measured was 3..4%,and RMSE was 18.68 mg/*** of ISM and OSM concentration were 3..9% and 3..2% *** inversion was more accurate when satellite-ground data were just in the same *** this situation,RE of ISM concentration dropped to 25.4%,and that of TSM and OSM reduced to 26.5% and 26.8% as well.

关键词： HJ-1 Satellite bio-optical property Chaohu Lake suspended matter

Alternate erosion and deposition in the Yangtze Estuary and the future change

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Journal of Geographical Sciences 2020年第1期30卷 145-163页

作者： zhu Boyuan LI Yitian YUE yao YANG Yunping liang Enhang ZHANG Chuncai BORTHWICK Alistair G.L. School of Hydraulic engineering Changsha University of Science&TechnologyChangsha 410114China key laboratory of water-{3. Sciences and water Disaster Prevention of Hunan Province Changsha 410114China School of water Resources and Hydropower engineering State Key Laboratory of Water Resources and Hydropower Engineering ScienceWuhan UniversityWuhan 430072China key laboratory of engineering {3. Tianjin Research Institute for Water Transport EngineeringMinistry of TransportTianjin 300456China The key laboratory of {3. and sediment Sciences Ministry of EducationCollege of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China School of engineering The University of EdinburghThe King’s BuildingsEdinburgh EH93JLUK

The morphological changing trend of the Yangtze Estuary, the largest estuary of Asia, has become a focus of research in recent years. Based on a long series of topographic data from 1950 to 2015, this paper studied the erosion-deposition pattern of the entire Yangtze Estuary. An alternation between erosion and deposition was found during the past 65 years, which was in correspondence to the alternation between flood and dry periods identified by multi-year average duration days of high-level water flow (defined as discharge ≥ 60,000 m3/s, namely, D≥60,000) from the Yangtze River Basin. A quantitative relationship was further developed between the erosional/depositional rate of the Yangtze Estuary and the interpreting variables of yearly water discharge, D≥60,000 and yearly river sediment load, with contributing rates of 1%, 59% and 40%, respectively. Mechanism behind the alternate erosion and deposition pattern was analyzed by examining residual water surface slope and the corresponding capacity of sediment transport in flood and dry periods. In flood periods, a larger discharge results in steeper slope of residual water level which permits a greater capacity of sediment transport. Therefore, more bed materials can be washed to the sea, leading to erosion of the estuary. In contrast, flatter slope of residual water level occurs in dry periods, and deposition dominates the estuarine area due to the decreased capacity of sediment transport and the increased backwater effect of flood-tide. Coastal dynamics and estuarine engineering projects alter the local morphological changes, but slightly affect the total erosional/depositional rate of the whole estuarine region. heavy sedimentation within the Yangtze Estuary after the impoundment of the Three Gorges Dam can be attributed to the reduced occurrence frequency of flood years due to water regulation by the dam, and largely (at least 36%-52%) sourced from the sea. Deposition is still poss

关键词： Yangtze Estuary erosion and deposition alternation total sediment load evolutional trend

Iron Isotope Compositions of Natural River and Lake Samples in the Karst Area,Guizhou Province,Southwest china

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Acta Geologica Sinica(English Edition) 2011年第3期85卷 712-722页

作者： SONG Liuting LIU Congqiang WANG Zhongliang zhu Xiangkun TENG Yanguo WANG Jinsheng TANG Suohan LI Jin liang Lili College of water Sciences Beijing Normal University Beijing 100875 China engineering Research Center of Groundwater Pollution Control and Remediation Ministry of Education Beijing 100875 China State key laboratory of environmental Geoc{3.mistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China

To better understand the Fe isotope characteristics of natural samples in the Karst area,the Fe isotope compositions of riverine suspended particulates,lake suspended particulates,lake {3.s,porewaters,phytoplanktons,and aerosols in the watersheds of Lake Aha（a mineralized water system）and Lake Hongfeng（a mesotrophic water system）,which are located in the Karst area, southwest china.were *** studied samples displayed a variable range betweenδ^（56）Fe=-2.03.and 0.3.‰.Aerosols and phytoplanktons have similar or slightly heavier Fe isotope compositions relative to the average of igneous *** isotope compositions of riverine Suspended Particulate Matter（SPM）were mainly affected by the types of *** particulates collected from tributaries seriously contaminated with coal mine drainages displayed negativeδ^（56）Fe values（-0.89‰to-0.3.‰）during summer,and there were significant increases ofδ^（56）Fe values in winter,except AR2,which was polluted with both coal mine drainage and sewage effluent. Characteristics of lakes have important influences on Fe isotope compositions of suspended particulates,lake {3.s,and *** epilimnetic particulate Fe of Lake Hongfeng hadδ^（56）Fe=-0.04‰to 0.13.,while lighter Fe isotope compositions were measured for particulate Fe from Lake Aha,ranging from-0.42‰to-0.09‰.{3.s collected from Hou Wu（HW）station of Lake Hongfeng have an averageδ^（56）Fe value of 0.09‰and their corresponding porewaters have lighter Fe isotope compositions,ranging from-0.57‰to-0.3.‰;no significant variations have been observed. For the liang Jiang Kou（LJK）station of Lake Aha,the content of reactive Fe and the concentration of sulfate were all *** to the reactive Fe recycling,including dissimilatory Fe reduction,adsorption, and Fe-sulfide formation,porewaters sampled near the {3. surface have been found to have aδ^（56）Fe value as low as-2.03.and an increase up to 0.12‰,with a burial depth of 10 *** contrast,a

关键词： Fe isotope composition karst riverine particulate lake particulate sediment porewater

Future climate change decreases multi-pathway but increases respiratory human health risks of PAHs across china

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National Science Open 2024年第2期3卷 128-147页

作者： Jiaao Bao Xinghui Xia Ying zhu Bingxiang Zhao Erxue Gu Yanan Liu Xiao Yun Zhenrui Zhang Nannan Xi Yong Geng Ying Xu Zhifeng Yang Derek C.G.Muir key laboratory of water and {3. Sciences of ministry of education State Key Laboratory of Water Environment SimulationSchool of EnvironmentBeijing Normal UniversityBeijing 100875China State environmental Protection key laboratory of environmental health Impact Assessment of Emerging Contaminants School of Environmental Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China College of Urban and environmental Sciences Laboratory for Earth Surface ProcessesSino-French Institute for Earth System SciencePeking UniversityBeijing 100871China National Climate Center China Meteorological AdministrationBeijing 100081China key laboratory for City Cluster environmental Safety and Green Development of t{3. ministry of education Institute of Environmental and Ecological EngineeringGuangdong University of TechnologyGuangzhou 510006China Aquatic Contaminants Research Division Environment and Climate Change CanadaBurlington L7S 1A1Canada

Future climate change will affect the environmental fate of hydrophobic organic contaminants(HOCs)and associated human health risks,yet the extent of these effects remains ***,we couple a high-resolution environmental multimedia model with a bioaccumulation model to study the multimedia distribution of 16 priority polycyclic aromatic hydrocarbons(PAHs),a group of HOCs,and assess future PAH-related human health risks under varying climate change scenarios over china.at a continental *** removing the effects of PAH emission changes,we find that the total PAH concentrations would decrease in the air,freshwater,{13.,soil,and organisms,while the high-molecular-weight PAH would increase in the air with climate warming from 1.5°C to 4°***,the multi-pathway exposure human health risks predominately influenced by dietary ingestion are expected to decrease by 1.7%–20.5%,while the respiratory risks are projected to rise by 0.2%–5.8%in the ***,the persistently high multi-pathway human health risks underscore the need for reducing future PAH emissions by 69%compared with 2009 levels in *** study demonstrates the urgency of limiting PAH emissions under future climate change for public health and highlights the importance of including the contribution of dietary ingestion in human health risk assessment.

关键词： polycyclic aromatic hydrocarbons future climate change human health risks emission reduction

Nitrous oxide reductase gene (nosZ) and N_2O reduction along the littoral gradient of a eutrophic freshwater lake

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Journal of environmental Sciences 2013年第1期25卷 44-52页

作者： Chaoxu Wang Guibing zhu Yu Wang Shanyun Wang Chengqing Yin State key laboratory of environmental Aquatic Quality Research Center for Eco-Environmental SciencesChinese Academy of Sciences university of Chinese Academy of Sciences State key laboratory of Urban water Resource and Environment Harbin Institute of Technology

Lake littoral zones are characterized by heterogeneity in the biogeochemistry of nutrient elements. This study aimed to explore the relationship between the nitrous oxide reductase gene （nosZ）-encoding denitrifier community composition/abundance and N2O reduction. Five samples （deep sediment, near-transition sediment, transition site, near-transition land and land soil） were collected along a littoral gradient of eutrophic Baiyangdian Lake, North china. To investigate the relationship between the nosZ-encoding denitrifier community structure and N20 reduction, the nosZ-encoding denitrifier community composition/abundance, potential denitrification rate （DNR） and potential N20 production rate （pN20） were investigated using molecular biological technologies and laboratory incubation experiments. The results showed that the average DNR of sediments was about 25 times higher than that of land soils, reaching 282.5 nmol N/（g dry weight （dw）.hr） and that the average pN20 of sediments was about 3.5 times higher than that of land soils, reaching 15.7 nmol N/（g dw-hr）. In the land area, the nosZ gene abundance showed a negative correlation with the N20/（N20＋N2） ratio, indicating that nosZ gene abundance dominated N20 reduction both in the surface soils of the land area and in the soil core of the transition site. Phylogenetic analysis showed that all the nosZ sequences recovered from sediment clustered closely with the isolates Azospirillum largimobile and Azospirillum irakense affiliated to Rhodospirillaceae in alpha-Proteobacteria, while about 92.3. （12/13. of the nosZ sequences recovered from land soil affiliated to Rhizobiaceae and Bradyrhizobiaceae in a-Proteobacteria. The community composition of nosZ gene-encoding denitrifiers appeared to be coupled with N20 reduction along the littoral gradient.

关键词： littoral gradient N2O reduction nosZ gene abundance community composition

Reductive immobilization and long-term remobilization of radioactive pertechnetate using bio-macromolecules stabilized zero valent iron nanoparticles

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Chinese Chemical Letters 2019年第12期30卷 2163-2168页

作者： Haodong Ji Yangmo zhu Jun Duan Wen Liu Dongye Zhao The key laboratory of {3. and sediment Science Ministry of EducationCollege of Environment Science and EngineeringPeking UniversityBeijing 100871China environmental engineering Program Department of Civil EngineeringAuburn UniversityAuburnAL 36849United States The beijing Innovation Center for engineering Science and Advanced Technology(BIC-ESAT) Peking UniversityBeijing 100871China Institute of environmental Science Taiyuan University of Science and TechnologyTaiyuan 030024China

Reductive immobilization of radioactive pertechnetate(99TcO4^-) in simulated groundwater was studied by prepared carboxymethyl cellulose(CMC) and starch stabilized zero valent iron nanoparticles(nZVI),and long-term remobilization of reduced Tc was also evaluated under anoxic and oxic *** stabilized nZVI can effectively reduce soluble 99Tc(Ⅶ) to insoluble 99 Tc(Ⅳ),and they can be easily delivered into a contaminated groundwater zone and facilitate in situ *** this study,CMCstabilized nZVI showed higher reactivity than that using starch as the *** experiments indicated that more than 99% of 99 Tc(Ⅶ)(CO=12 mg/mL) was reduced and removed from groundwater by CMC-stabilized nZVI with a CMC content of 0.2%(w/w) at a broad pH of 5-8.X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS) analyses further confirmed that 99Tc(Ⅶ)O4^-transformed into 99Tc(Ⅳ)O2(s).The presence of bicarbonate exhibited insignificant effect on Tc immobilization,while humic acid(HA) inhibited reaction mainly due to retardation on electron transfer and formation of Tc(IV)-HA *** interesting,the immobilized Tc(Ⅳ) remained insoluble even after 120 d under anoxic condition,while only^21 % was remobilized when exposed to ***,biomacromolecules stabilized nZVI nanoparticles could be a viable alternative for in situ remediation of radioactive contamination in groundwater.

关键词： Reductive immobilization Radionuclide Stabilized nanoparticles Zero valent iron Groundwater Technetium

Effect of Sb dopant amount on the structure and electrocatalytic capability of Ti/Sb-SnO_2 electrodes in the oxidation of 4-chlorophenol

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Journal of environmental Sciences 2007年第11期19卷 1380-1386页

作者： KONG Jiang-tao SHI Shao-yuan zhu Xiu-ping NI Jin-ren key laboratory of water and {3. Sciences Ministry of Education of China department of environmental engineering Peking University Beijing 100871 China State key laboratory of Biochemical {3. Institute of Process Engineering Chinese Academy of Sciences Beijing 100080 China

Ti/Sb-SnO2 anodes were prepared by thermal decomposition to examine the influence of the amount of Sb dopant on the structure and electrocatalytic capability of the electrodes in the oxidation of 4-chlorophenol. The physicochemical properties of the Sb-SnO2 coating were markedly influenced by different amounts of Sb dopant. The electrodes, which contained 5% Sb dopant in the coating, presented a much more homogenous surface and much smaller mud-cracks, compared with Ti/Sb-SnO2 electrodes containing 10% or 15% Sb dopant, which exibited larger mud cracks and pores on the surface. However, the main microstructure remained unchanged with the addition of the Sb dopant. No new crystal phase was observed by X-ray diffraction （XRD）. The electrochemical oxidation of 4-chlorophenol on the Ti/SnO2 electrode with 5% Sb dopant was inclined to electrochemical combustion; while for those containing more Sb dopant, intermediate species were accumulated. The electrodes with 5% Sb dopant showed the highest efficiency in the bulk electrolysis of 4-chlorophenol at a current density of 20 mA/cm^2 for 180 min; and the removal rates of 4-chlorophenol and COD were 51.0% and 48.9%, respectively.

关键词： 4-chlorophenol cyclic voltammogram electrochemical oxidation Sb dopant Ti/Sb-SnO2 electrode

Effects of seasonal climatic variability on several toxic contaminants in urban lakes: Implications for the impacts of climate change

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Journal of environmental Sciences 2014年第12期26卷 2369-2378页

作者： Qiong Wu Xinghui Xia Xinli Mou Baotong zhu Pujun Zhao Haiyang Dong State key laboratory of water Environment Simulation Key Laboratory of Water and Sediment Sciences of Ministry of EducationSchool of Environment Beijing Normal University School of Chemical and environmental engineering Chongqing Three Gorges University

Climate change is supposed to have influences on water quality and ecosystem. However, only few studies have assessed the effect of climate change on environmental toxic contaminants in urban lakes. In this research, response of several toxic contaminants in twelve urban lakes in {3., china. to the seasonal variations in climatic factors was studied. Fluorides, volatile phenols, arsenic, selenium, and other water quality parameters were analyzed monthly from2009 to 2012. Multivariate statistical methods including principle component analysis, cluster analysis, and multiple regression analysis were performed to study the relationship between contaminants and climatic factors including temperature, precipitation, wind speed, and sunshine duration. Fluoride and arsenic concentrations in most urban lakes exhibited a significant positive correlation with temperature/precipitation, which is mainly caused by rainfall induced diffuse pollution. A negative correlation was observed between volatile phenols and temperature/precipitation, and this could be explained by their enhanced volatilization and biodegradation rates caused by higher temperature. Selenium did not show a significant response to climatic factor variations, which was attributed to low selenium contents in the lakes and soils. Moreover, the response degrees of contaminants to climatic variations differ among lakes with different contamination levels. On average, temperature/precipitation contributed to 8%, 15%, and 12% of the variations in volatile phenols, arsenic, and fluorides,respectively. {3. is undergoing increased temperature and heavy rainfall frequency during the past five decades. This study suggests that water quality related to fluoride and arsenic concentrations of most urban lakes in {3. is becoming worse under this climate change trend.

关键词： Climatic variations Urban lakes Volatile phenols Arsenic Fluorides Selenium water quality

Call for joint international actions to improve scientific understanding and address soil erosion and riverine sediment issues in mountainous regions

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International Soil and water Conservation Research 2023年第3期11卷 586-588页

作者： Fan Zhang Baoyuan Liu Liping zhu Richard Cruse Dongfeng Li Panos Panagos Pasquale Borrelli Yakov Kuzyakov Shaoshan An State key laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijingChina beijing Normal university BeijingChina Agronomy department at Iowa State university AmesIAUnited States department of Geography National University of SingaporeKent RidgeSingapore European Commission Joint Research CentreIspraItaly department of environmental Sciences Environmental GeosciencesUniversity of BaselBaselSwitzerland department of Science Roma Tre UniversityRomeItaly department of Soil Science of Temperate Ecosystems Department of Agricultural Soil ScienceGeorg-August-University of GottingenGermany Research Center of water and Soil Conservation and Ecological Environment Chinese Academy of Sciences&Ministry of EducationYanglingShaanxiChina

During the International Workshop on Soil Erosion and Riverine sediment in Mountainous Regions held in November 2022,scientists from many countries shared their state-of-the-art knowledge and brainstormed to improve scientific understanding for coping with climate change and anthropogenic *** summarized in this discussion includes proposed key scientific questions and suggested joint actions to reduce soil erosion and riverine sediment problems in mountainous regions.

关键词： soil mountainous summarized