| Since human beings entered the industrial society,the influence of human activities on the heavy metal pollution in the lake reservoir has become increasingly significant,and has caused serious harm to the water ecosystem and human health.Aha lake this article selects the typical heavy metal pollution of rivers and library core area,through the system to collect water samples,the water-sediment interface,sediment column core environmental samples,such as the time and space distribution characteristics of heavy metals and accumulation process,reveals the interface between sediment and water of heavy metal migration transformation mechanism,and its potential environmental risk sources,for preventing the pollution of heavy metals in lake library and scientific management to provide reference evidence.The main achievements are as follows:(1)Aha reservoir in overlying water average content of heavy metals in the surface water environment quality standard(GB 3838—2002)? class standard and the drinking water health standard(GB 5749—2006),not under heavy metal pollution,suitable as a source of drinking water.The migration and transformation processes of Co,Ni and As in aha reservoir are all affected by the iron-manganese cycle,and Cr,Sb and Pb heavy metals may have the same pollution sources.The results of heavy metal diffusion flux at the sediment-water interface show that the diffusion and release of Co,Ni,As,Pb and other four heavy metals in the sediment pore water have a certain impact on the overburden water body,while the sediment has a good purification and adsorption effect on Zn.Compared with the previous study on the spatial and temporal distribution characteristics and diffusion flux of heavy metals in the overlying water and pore water of aha reservoir,it is found that the pollution prevention and control measures of aha reservoir have played a positive role in the past decade,and the water pollution of heavy metals has been significantly improved.(2)The total concentrations of heavy metals at the sampling points were 1#>2#>3#>4#,and the mean values of individual heavy metal concentrations were Zn>Ni>Cr>Co>Cu>Pb>As>Sb>Cd.The morphologi cal analysis of heavy metals showed that the relative proportion of bioavailable states of each element was: Cd>Co>Zn>Ni>Pb> Cu>As>Cr?Sb,and the pollution point was 1#>3#>2#>4#,the bioavailability of Zn,Co,Ni and Cd in the sediments of aha reservoir was relatively high,so the damage to the environment should be paid attention to.However,Cu,Cr and Sb have good stability in the sediments of aha reservoir and have relatively little impact on the environment.(3)Different methods such as ecological risk assessment,quality benchmark and index were used to evaluate the sediment pollution effect of aha reservoir.Results show that the peak all in 1 #(the middle of a lake),Cd pollution and ecological risk value is higher,SQGs show that Ni element of benthic bring higher toxicity hazard,and frequently happens,the rest of the elements of the potential toxicity were bigger.Multivariate statistical and correlation matrix of heavy metals were identified three sources,three principal components,principal component analysis to determine Co,Ni,Cu,Zn,Cd source correlation with other people,may come from coal mine waste water discharge.Cr,As,its concentration is close to the background value,mineral weathering and atmospheric precipitation may be causing the accumulation of the sediment of Cr and As the main natural activities.Sb is related to Pb,mainly from industrial wastewater and domestic sewage. |
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