Pollution assessment and source tracking of heavy metals in surface sediments of Xinyanggang River

The ecological risk of six heavy metals (Cr, Ni, Cu, Zn, As, Pb) in the surface sediments collected from the Xinyanggang River in Yancheng, Jiangsu, East China was evaluated using the enrichment coefficient method and potential ecological risk indexing, combined with multivariate analysis method and positive matrix factorization model (PMF) for source analysis. Results show that: (1) The average concentrations of the heavy metals were Cr (70.63 mg/kg), Ni (27.73 mg/kg), Cu (21.60 mg/kg), Zn (21.60 mg/kg), As (9.01 mg/kg), and Pb (20.38 mg/kg). The average levels of metals are in the order of Zn > Cr > Ni > Cu > Pb > As. Six heavy metals in most of the samples were at the levels of low and moderate enrichment. The potential ecological risk index indicated low ecological risk in the whole study area. The sources of heavy metals were divided into three categories. Cu, Zn, and Pb were derived from industrial wastewater, urban domestic sewage, and urban traffic (44.60%); Cr and Ni mainly came from the emission of urban manufacturing operations (34.50%); and As was mainly from agriculture and breeding pollution (20.90%).