Distribution And Accumulation Of Heavy Metals In The Oncmelania Hupensis And It As A Biomonitor In The Poyang Lake Wetland

The paper takes the Oncomelania hupensis in the Poyang Lake wetland as our research object. We mainly study the heavy metal's concentration and space-time distribution of Cu, Zn, Pb, Cr in the Oncomelania hupensis and the difference between the content of heavy metal in the tissue and shell of the Oncomelania hupensis. The influence of the Oncomelania hupensis size and cumulation faculty on the accumulation. And we analyze the correlation coefficient between the concentration of heavy metal in soil and the Oncomelania hupensis, as well as between the concentration of the exchangeable form and carbonate combination form of heavy metal and the concentration of heavy metal in tissue of the Oncomelania hupensis. Thus it provide the basis on the Oncomelania hupensis as a biomonitor of soil heavy metal pollution in the Poyang Lake wetland. The primary results as follows:1. Although there are different change tendency of different heavy metal in various sampling sites, the order of the heavy metal's content in soil of the Poyang Lake wetland is Zn>Pb>Cu>Cr. The major form of heavy metals are residual form. We analyze the correlation coefficient among the forms, and find there is a significant correlation between the exchangeable form and carbonate combination form of Cu and Zn. At the same time, we have a environmental assessment on heavy metal pollution in the soil of the Poyang Lake with potential ecological risk index, and the order of the RI degrre is ZHX>WCH>WH>XZ>NJ.2. The enrichment content of Cu, Zn, Pb, Cr in the Oncomelania hupensis shows definite seasonal difference. Compared with the Oncomelania hupensis sampling in June, these sampling in October have the lower content of Cu and Zn, and the higher content of Pb and Cr.3. The enrichment content of the Oncomelania hupensis to these heavy metals exists regional difference. And there is a significant correlation between the concentration of Pb and Cr in the Oncomelania hupensis in different sites.4. We use the Metal Pollution Index (MPI) to appraise the accumulation of heavy metal in the Oncomelania hupensis, and the result shows that except XZ, the MPI of other sampling sites are all close.5. The cumulation of the Oncomelania hupensis to heavy metal has segmental difference. In our study it shows that most heavy metals in the Oncomelania hupensis concentrate on the tissue. And there are a significant linear relationship between the concentration of Cu, Pb, Cr in the tissue and shell of the Oncomelania hupensis.6. Size and cumulation faculty of the Oncomelania hupensis can affect the accumulation of heavy metals. Different size of the Oncomelania hupensis has various content of different heavy metal, and the order of cumulation faculty the Oncomelania hupensis is Cu>Zn>Cr>Pb.7. Although the content of heavy metal in soil has no significant corelation with the content of heavy metal in the Oncomelania hupensis, the concentration of Cu and Pb in the Oncomelania hupensis (spiral>7) tissue has a significant linear relationship with the concentration of the exchangeable form and carbonate combination form in the soil. So we can use the Oncomelania hupensis (spiral>7) as a biomonitor to detect the concentration of the exchangeable form and carbonate combination form of Cu and Pb in soil of Poyang Lake wetland.