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Long-term joint effect of nutrients and temperature increase on algal growth in lake Taihu,China

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Journal of Environmental Sciences 2011年第2期23卷 222-227页

作者： Chun Ye Zhemin Shen Tao Zhang Maohong Fan Yangming Lei Jianda Zhang School of Environmental Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China Chinese Research Academy of Environmental Sciences Beijing 100012 China School of Civil and Environmental Engineering Georgia Institute of Technology Atlanta GA 30332 USA School of Energy Resources and Department of Chemical & Petroleum Engineering University of Wyoming Laramie WY 82071 USA Jiangsu Environmental Monitoring Center 241Fenghuangxijie Road Nanjiang 210036 China

To study how global warming and eutrophication affect water ecosystems, a multiplicative growth Monod model, modified by incorporating the Arrhenius equation, was applied to lake Taihu to quantitatively study the relationships between algal biomass and both nutrients and temperature using long-term data. To qualitatively assess which factor was a limitation of the improved model, temperature variables were calculated using annual mean air temperature （AT）, water temperature （WT）, and their average temperature （ST）, while substrate variables were calculated using annual mean total nitrogen （TN）, total phosphorus （TP）, and their weighted aggregate （R）, respectively. The nine fitted curves showed that TN and AT were two important factors influencing algal growth; AT limited growth as algal photosynthesis is mainly carried out near the water surface; N leakage of phytoplankton and internal phosphorus load from sediment explains why TN was the best predictor of peak biomass using the Monod model. The fitted results suggest that annual mean algal biomass increased by 0.145 times when annual mean AT increased by 1.0℃. Results also showed that the more eutrophic the lake, the greater the effect AT had on algal growth. Subsequently, the long-term joint effect of annual temperature increase and eutrophication to water ecosystems can be quantitatively assessed and predicted.

关键词： lake eutrophication algal bloom global warming

Highly efficient extraction of lithium from salt lake brine by LiAl-layered double hydroxides as lithium-ion-selective capturing material

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Journal of Energy Chemistry 2019年第7期28卷 80-87页

作者： Ying Sun Xiaoyu Guo Shaofang Hu Xu Xiang State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology

The extraction of lithium from salt lake brine in the Chinese Qaidam Basin is challenging due to its high Mg/Li and Na/Li ratios. Herein, we utilized a reaction-coupled separation technology to separate sodium and lithium ions from a high Na/Li ratio brine(Na/Li = 48.7, w/w) and extracted lithium with Li Al-layered double hydroxides(Li Al-LDHs). The Li Al-LDHs act as lithium-ion-selective capturing materials from multication brines. That is, the lithium ions selectively enter the solid phase to form Li Al-LDHs, and the sodium ions are still retained in the liquid phase. This is because the lithium ions can be incorporated into the structural vacancies of LiAl-LDHs, whereas the sodium ions cannot. The effects of reaction conditions on lithium loss and separation efficiency were investigated at both the nucleation and the crystallization stage, e.g., the nucleation rotating speed, the Li/Al molar ratio, the crystallization temperature and time, and co-existing cations. The lithium loss is as low as 3.93% under optimal separation *** sodium ions remained in the solution. Consequently, an excellent Na/Li separation efficiency was achieved by this reaction-coupled separation technology. These findings confirm that LiAl-LDHs play a critical function in selectively capturing lithium ions from brines with a high Na/Li ratio, which is useful for the extraction of lithium ions from the abundant salt lake brine resources in China.

关键词： LiAl-LDHs Lithium extraction Energy metal Salt lake brine Reaction-coupled separation technology

Spatial and historical distribution of organic phosphorus driven by environment conditions in lake sediments

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Journal of Environmental Sciences 2018年第2期30卷 32-41页

作者： Changwei Lü Jiang He Bing Wang School of Ecology and Environment Inner Mongolia University Institute of Environmental Geology Inner Mongolia University Forestry College Inner Mongolia Agricultural University

The chemistry of sedimentary organic phosphorus（OP） and its fraction distribution in sediments are greatly influenced by environmental conditions such as terrestrial inputs and runoffs. The linkage of OP with environmental conditions was analyzed on the basis of OP spatial and historical distributions in lake sediments. The redundancy analysis and OP spatial distribution results suggested that both Na OH-OP（OP extracted by Na OH） and Re-OP（residual OP） in surface sediments from the selected 13 lakes reflected the gradient effects of environmental conditions and the autochthonous and/or allochthonous inputs driven by latitude zonality in China. The lake level and salinity of lake Hulun and the runoff and precipitation of its drainage basin were reconstructed on the basis of the geochemistry index. This work showed that a gradient in weather conditions presented by the latitude zonality in China impacts the OP accumulation through multiple drivers and in many *** drivers are mainly precipitation and temperature, governing organic matter（OM）production, degradation rate and transportation in the watershed. Over a long temporal dimension（4000 years）, the vertical distributions of Re-OP and Na OH-OP based on a dated sediment profile from HLH were largely regulated by the autochthonous and/or allochthonous inputs, which depended on the environmental and climate conditions and anthropogenic activities in the drainage basin. This work provides useful environmental geochemistry information to understand the inherent linkage of OP fractionation with environmental conditions and lake evolution.

关键词： Organic phosphorus Spatial and historical distribution Environmental conditions Sediment lake

Glacial lake Area Changes in High Mountain Asia during 1990-2020 Using Satellite Remote Sensing

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Research 2023年第2期2022卷 1-23页

作者： Meimei Zhang Fang Chen Huadong Guo Lu Yi Jiangyuan Zeng Bin Li International Research Center of Big Data for Sustainable Development Goals Beijing 100094China Key Laboratory of Digital Earth Science Aerospace Information Research InstituteChinese Academy of SciencesNo.9 Dengzhuang South RoadBeijing 100094China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Coastal Environment and Resources Research of Zhejiang Province School of EngineeringWestlake UniversityHangzhou 310024China State Key Laboratory of Remote Sensing Science Aerospace Information Research InstituteChinese Academy of Sciences Beijing 100094China

Changes in a large-scale glacial lake area directly reflect the regional glacier status and climate ***,long time series of glacial lake dataset and comprehensive investigation of the spatiotemporal changes in the gla... 详细信息

关键词： glacial glacier lake

Efects of physical and chemical characteristics of surface sediments in the formation of shallow lake algae-induced black bloom

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Journal of Environmental Sciences 2013年第12期25卷 2353-2360页

作者： Qiushi Shen Cheng Liu Qilin Zhou Jingge Shang Lei Zhang ChengXin Fan University of Chinese Academy of Sciences State Key Laboratory of lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences

Surface sediments are closely related to lake black blooms. The dissolved oxygen （DO） distribution and its penetration depth in surface sediments as well as the migration and transformation of redox sensitive elements such as Fe and S at the sediment-water interface are important factors that could influence the formation of the black bloom. In this study, dredged and undredged sediment cores with different surface properties were used to simulate black blooms in the laboratory. The Micro Profiling System was employed to explore features of the DO and ∑H2S distribution at the sediment-water interface. Physical and chemical characteristics in sediments and pore waters were also analyzed. The results showed that sediment dredging effectively suppressed the black blooms. In the undredged treatment, DO penetration depth was only 50 μm. Fe^2＋ concentrations, ∑H2S concentrations, and ∑H2S production rates were remarkably higher in surface sediments and pore waters compared to control and dredged treatments. Furthermore, depletion of DO and accumulation of Fe^2＋ and ∑H2S in surface sediments and pore waters provided favorable redox environments and necessary material sources for the blooms. The study results proved that physical and chemical characteristics in surface sediments are important factors in the formation of the black bloom, and could provide scientific guidance for emergency treatment and long-term pre-control of black blooms.

关键词： black bloom sediment-water interface dredging sediment micro interface lake

lake inventory and potentially dangerous glacial lakes in the Nyang Qu Basin of China between 1970 and 2016

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Journal of Mountain Science 2020年第4期17卷 851-870页

作者： QI Miao-miao LIU Shi-yin YAO Xiao-jun Richard Grünwald GAO Yong-peng DUAN Hong-yu LIU Juan Institute of International Rivers and Eco-Security Yunnan UniversityKunming 650091China Yunnan Key Laboratory of International Rivers and Transboundary Eco-security Kunming 650091China College of Geography and Environment Sciences Northwest Normal UniversityLanzhou 730070China

There are a large number of glaciers and lakes developed in the Nyang Qu Basin of China. Recent climate change has significant impacted on the high-mountain glacial environment. Rapid melting of glaciers contributes to the formation and expansion of moraine-dammed lakes which increase the probability of glacial lake outburst floods(GLOFs). We calculated a multi-temporal lake inventory based on(1) topographic maps in the 1970 s,(2) satellite imageries from 1990 to 2016,(3) First Chinese Glacier Inventory(FCGI),(4) Glacier Inventory of Southeastern Tibet(GIST) and(5) meteorological data. A total of 880 lakes(>0.01 km^2) have been mapped in 2016, with 318 being glacial lakes(GLs) and 462 non-glacier lakes(NGLs). Most of the lakes were mainly located at 4500 m a.s.l. and the lakes dominated by small lakes(lakes(PDMDLs), covering a total area of 5.88 km2 in the Nyang Qu Basin. There can be found 4 GLs with very high risk, 3 GLs with high risk, 4 GLs with medium risk and 4 GLs with low risk of GLOFs susceptibility. The findings of this study can be used for the future policy of risk management and also be adapted for promoting water resources management.

关键词： lake Inventory Potentially dangerous moraine-dammed lakes(PDMDLs) Hazard assessment Tibetan Plateau Nyang Qu Basin

Numerical investigation of the effects of aquatic plants on wind-induced currents in Taihu lake in China

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Journal of Hydrodynamics 2019年第4期31卷 778-787页

作者： Tian-ping Xu Ming-liang Zhang Hcng-zhi Jiang Jun Tang Hong-xing Zhang Hui-ting Qiao School of Ocean Science and Environment Dalian Ocean University Dalian 116023 China National Marine Environmental Monitoring Center Dalian 116023 China State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116023 China

Shallow lakes are an important part of the earth's water circulation system, and many factors may impact the evolution of the lake water circulation, including the wind, the topography, the human activities, and the aquatic plants. This paper proposes a depth-averaged 2-D hydrodynamic model to investigate the interaction of the wind-induced current and the aquatic plant in the lake. The model is based on the generalized shallow water equations solved by an explicit finite volume method with unstructured triangular grids. The drag force of the vegetation is considered into the momentum equations as the source term. Remote sensing techniques are applied to evaluate the aquatic vegetation in the Taihu lake, China, based on Landsat TM satellite images. The study model is then used to simulate the characteristics of the wind-induced currents in the Taihu lake, without and with the vegetation effects. The simulation results are in good agreement with the field measurements, demonstrating that the aquatic plants significantly affect the magnitude of the velocity and the flow circulation induced by the wind in the Taihu lake. In addition, a sensitivity analysis reveals that the plant parameters (the density and the drag force coefficient) are significant factors influencing the velocity and the structure of the currents in the Taihu lake.

关键词： Finite volume method Roe solver shallow lake wind-induced current aquatic plant

Distribution and relationship between antimicrobial resistance genes and heavy metals in surface sediments of Taihu lake,China

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Journal of Environmental Sciences 2019年第3期31卷 323-335页

作者： Okugbe E.Ohore Felix Gyawu Addo Songhe Zhang Nini Han Kwaku Anim-Larbi Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow lakes College of Environment Hohai University

Heavy metals, pharmaceuticals, and other wastes released into the environment can significantly influence environmental antibiotic resistance. We investigated the occurrence of 22 antimicrobial resistance genes(ARGs) and 10 heavy metal concentrations, and the relationship between ARGs and heavy metals in surface sediment from seven sites of lake Taihu. The results showed significant correlations(p lake. In the surface sediments, heavy metals showed an interaction with resistance genes, but the strength of interaction was diminished with increasing depth. For most of the heavy metals, the concentration of elements in the top sediments was higher than that in other *** resistance genes(tet(A), tet(B), tet(D), tet(E) and tet(O), β-lactam resistance genes(SHV, TEM, CTX, OXA and OXY) and sulfonamide resistance genes(sulA, sul1, sul2, sul3 and int-1) were detected. They showed a trend which inferred a statistically significant increase followed by decreases in the relative abundance of these ARGs(normalized to 16 S rRNA genes) with increasing depth. This study revealed that tet(A), tet(O), TEM, OXY, int-1, sul1 and sul3 were widespread in surface sediments with high abundance, indicating that these genes deserve more attention in future work.

关键词： Antibiotic resistance genes Heavy metals Surface sediments Taihu lake Wastewater treatment plants Pollution

Temporal variation of major nutrients and probabilistic eutrophication evaluation based on stochastic-fuzzy method in Honghu lake, Middle China

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Science China(Technological Sciences) 2019年第3期62卷 417-426页

作者： LI Fei QIU ZhenZhen ZHANG JingDong LIU ChaoYang CAI Ying XIAO MinSi ZHU LiYun Research Center for Environment and Health Zhongnan University of Economics and Law School of Information and Safety Engineering Zhongnan University of Economics and Law

Honghu lake, which is listed in the Ramsar Convention, was found to be contaminated with elevated nutrients to a certain *** study investigated the seasonal variation of major nutrients and probabilistic eutrophic state in surface water from Honghu lake. Average concentrations of total nitrogen(TN), total phosphorus(TP), chlorophyll-a(Chl-a), chemical oxygen demand(COD_(Mn)) and transparency(SD) in summer and winter generally exceeded Grade III of the Chinese environmental quality standards for surface water(GB 3838-2002), with the exception of COD_(Mn)in winter. Mean concentrations of Chl-a and COD_(Mn) in summer were higher than that in winter, while mean concentrations of TN, TP and SD were slightly higher in winter. The improved probabilistic comprehensive trophic level index(PTLI) method based on stochastic-fuzzy theory was established to evaluate the eutrophic state in Honghu lake. Compared with the Monte-Carlo sampling method, the Latin Hypercube sampling(LH-TFN) method was selected for the evaluation simulation due to its efficiency and stability. Evaluation results indicated that mean PTLI in summer(69.70) and winter(61.96) were both subordinated to Grade IV(Medium eutrophication). The corresponding reliability of eutrophication level subordinating to Grade IV in summer was of relatively low reliability(51.27%),which might mislead decision makers to some extent and suggest recheck. The probabilistic eutrophication level in summer developed with a trend from medium to severe eutrophication. Sensitivity analysis illustrated that COD_(Mn)and Chl-a were the priority pollutants in summer, with the contributions to PTLI of 43.3% and 22.5% respectively. Chl-a was the priority pollutant in winter, with the contribution to PTLI up to 51.3%.

关键词： surface water Honghu lake seasonal variation eutrophic state stochastic-fuzzy theory