Abstract:
The contents of heavy metals, including Cu, Zn, Pb, Cd and Cr, in the sediments of 8 sections in the Huiji Rriver were analyzed for the last continuous five years. The single factor pollution index, integrated pollution index, geoaccumulation index and potential ecological risk index were adopted to evaluate the potential risk of the heavy metal pollution. The monitoring results indicated that the sediments from 8 monitoring sections had been polluted to different degree except that from Sunlitang bridge section which was at the upstream of Huiji river, while the sediment from Pitun bridge showed the highest pollution risk, at the severity level of severe pollution.The comprehensive pollution indices suggested that the river was under heavy pollution by Cd, light pollution by Cu and Pb, slight pollution by Zn and no pollution by Cr. The comprehensive pollution indices of most sediment ranged from 0.55 to 1.89, except 6.74 for Pitun bridge section. The geoaccumulation indices suggested that the most severe pollution was caused by Cd, which leaded to a high
Igeo at 3.50, referred to heavy pollution. The river was still under moderate pollution by Cu and Pb, light pollution by Zn. The potential ecological risk indices suggested that the river was under high risk of Cd pollution and low risk of other four heavy metals pollution. The comprehensive potential ecological risk was high, which is pecked at 2 233.50 in the Pitun bridge section, mainly because of the high cadmium concentration in the sediment.