Heavy metal pollution and potential ecological risk in urban river sediment of Huai’an City, China

Abstract

Sediment heavy metal pollutant monitoring was carried out at 16 monitoring points of three rivers and one lake in Huai’an city. The contamination degree of heavy metals was evaluated by geoaccumulation index. The potential ecological risk of heavy metals was assessed. The results showed that Hg and Cu geoaccumulation index class exceeded moderately polluted level, especially Hg, and two monitoring points reached highly polluted level. Hg pollution is at a high/extremely high potential ecological risk. Most of the other single-factor heavy metal indexes are at a low ecological risk level. The comprehensive ecological risk index of 6 monitoring points showed a high potential ecological risk. The Hg in urban rivers sediment of Huai’an may come from the deposition of long-term domestic sewage discharge or domestic refuse dump.