Response Analysis Of Diatom Markers Under Heavy Metal Pollution In The Waters Of Le'an River

Because there are abundant metal mineral resources in the upper banks of the Le'an River Basin,the waste water discharged from the mining operation causes heavy metal pollution in the river,which causes potential harm to the lives and health of people,livestock and birds on both sides of the river.The combination of diatom species and even some individual diatoms have a good indicative effect on the water environment.The species composition of epiphytic diatoms in various sections of the Le'an River and the ecological characteristics of the temporal and spatial distribution of epiphytic diatoms under heavy metal pollution were studied.It can provide scientific practice for river water environment monitoring and provide research basis for remediation of heavy metal pollution in water body.In this paper,taking Le'an River as the research area and epiphytic diatoms as the research object,12 sampling sites were set up and sampled in four seasons.The correlation analysis and regression analysis were used.The response indicator relationship between epiphytic diatoms and heavy metal Cu,Pb,Cd,Zn in Lean River was analyzed by?DCA?,redundancy analysis?RDA?and other methods.The main results are as follows:?1?70 species of epiphytic diatoms belonging to 2 classes,5 orders,8 families and 21genera were identified in 12 sampling sites of Le'an River.The biomass of diatoms showed a trend of spring,autumn>summer>winter.The samples with poor water quality were few,and the dominant species of epiphytic diatoms were different;?2?the variation range of diversity index?H?is 1.82³.61,the total average is2.731.The variation of evenness index?E?is 0.22⁰.57,the total average is 0.418,and the water quality of Le'an River is?-medium sewage in the whole year;?3?Through the determination of heavy metal Cu,Pb,Cd,Zn in the water body and sediment of Le'an River,it is found that there are obvious differences in the distribution of each element in various points of Le'an River.The heavy metal content in sediment of Dexing section is the highest and all of them exceed the environmental quality standard;?4?the correlation analysis of four heavy metal elements and the abundance of epiphytic diatoms showed that the abundance of diatoms in Le'an River was positively correlated with the content of Cu,Pb,Cd,Zn.The linear regression equations of the abundance of epiphytic diatoms established by Cu,Pb,Cd,Zn were:y=1.325x+302.381;y=9.786x+342.618;y=121.254x+298.841;y=3.258x+337.913,respectively.The multivariate linear regression equation of the abundance of epiphytic diatoms established by Cu,Pb,Cd,Zn was:y=0.965x₁-0.822x₂+14.701x₃+1.703x₄+290.640;?5?the analysis of the relationship between diatom community and heavy metals showed that Cyclotella,Frustulia,Melosira was positively correlated with the environmental factor pH,and it was positively correlated with the concentration of heavy metal Cu,Pb,Cd,Zn;?6?N.viridula and F.capucina were the indicator species of Cu heavy metal pollution.A.minutissima and P.subcapitata are the indicator species of heavy metal pollution in Pb rivers.N.palea and G.parvulum are the indicator species of Cd heavy metal river pollution.C.ventricosa and S.ulna is an indicator of heavy metal pollution in Zn rivers.A.nodusa and F.crotomensis also have a certain tolerance to metals and are resistant to heavy metal pollution.SHE,IDP,LOBO index is suitable for evaluating water quality evaluation of various sections of Le'an River.