Distribution feature of heavy metals in bottom sediments of Beijing-Hangzhou Grand Canal (Northern Section in Jiangsu Province)

摘要

Northern Section in Jiangsu Province of the Beijing-Hangzhou Grand Canal (from Yangzhou City to Weishan lake) is an important part of water transfer from south to north project (east route) because the water quality will impact the quality of transportation water. In recent years, many local governments have been paying more attention to control the water quality discharged into this river from different tributary, but water pollution of internal source caused by the release of heavy metals in the bottom sediment have not been paying close attention. We have studied the pollution feature of heavy metal in bottom sediments of the northern section in Jiangsu Province of Beijing-Hangzhou Grand Canal supported by the Doctoral Foundation of Education Ministry of China. There are 56 samples to be collected by a special sampling equipment. The contents of heavy metals including Cu, Cr, Zn, Pb were analysed by ICP-MS and Cold Atomic Fluorophotometry is employed to analyse the contents of Hg and As. Geo-accumulation index is employed to assess pollution degree. The maximum concentrations of heavy metals of Cu, Cr, Zn, Hg, As and Pb are 106.3, 153.10, 725.20, 0.48, 29.25,154.10mg/kg respectively. The result assessed by Geo-accumulation index indicated that the bottom sediments in some parts have polluted by the heavy metals in different degrees and Pb pollution is up to moderate. For the other heavy metals, pollution is also up to light. Once balance of heavy metal between river water and the bottom sediments is upset when water transportation will be informally operated, the heavy metals in the bottom sediments can be released into water to make a internal source pollution. We should pay more attention to this issue and take some prevention measures.