Heavy Metals Concentration And Contamination In Aquatic Plants And Sediments In Taihu Lake

Heavy metals contamination has already become one of the world serious damages of environment pollution, because of its wide sources and stability, invisibility, and non-degradability. This article select populated and highly developed Taihu Lake basin. Heavy metals contents in aquatic plants such as Potamogetom malaianus , Nymphoides peltata, Vallisneria spiralis, Ceratophyllum demersum, Hydrilla verticillata, Myriophyllum spicatum were measured. In addition, historical variations of heavy metals bound to different fractions in Meiliang sediments from north Taihu Lake were also measured, where pollution began earlier and became more serious, in order to reveal sediments reaction to local industry development.On the basis of our data, heavy metals concentrations in aquatic plants is several times, even several dozen times more than 80's, and heavy metals contents are different in different plants. On the whole, Hydrilla verticillata, Ceratophyllum demersum, Vallisneria spiralis have a good ability to absorb heavy metals, Nymphoides peltata does not. By comparing heavy metals contents in Potamogetom malaianus stem and leaf, Cr,Cu,Ni,Pb,Zn contents in Potamogetom malaianus leaf is largely higher than in stem. Mn contents is reversed. Through comparison between heavy metals contents in Potamogetom malaianus in XQ and DM profiles, the amount of heavy metals absorbed by Potamogetom malaianus is tend to grow along the current inflow. From which we can infer it is water flow that cause heavy metals inequable distribution in water, so that heavy metals contents in Potamogetom malaianus from two profiles varied.Accepting industrial, agricultural and routine polluted water from Wuxi City, heavy metals pollution in Meiliang Bay became more and more serious. On the basis of our data, heavy metals concentration increased step by step in the near century, especially increased largely from late 70's to present, demonstrating a similar trends to industry development in Wuxi City. Sequential extraction method was used to gain heavy metals contents in different fractions. Heavy metals contents in residual is almost invariable. Heavy metals contents in soluable, exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter increased but differently, the contents bound to Fe-Mn oxides is the main increased one, indicating that heavy metals is discharged mainly in bound to Fe-Mn oxides in industrial polluted water into Meiliang Bay. By use of index of enrichment factor, heavy metals contamination in Meiliang Bay is quantitatively analysed. By comparing the concentrations of Pb in Fe-Mn oxides fraction with historical industrial product values of Wuxi City, their similar trends suggest that the increasingly environmental pollution is due to a fast development of industries around northern Taihu region, further indicating that heavy metals was mainly as a form of bound to Fe-Mn oxides into the Taihu Lake ecosystem.