Spatial distribution, ecological risk assessment and source analysis of heavy metals pollution in urban lake sediments of Huaihe River Basin

Abstract

Abstract In order to understand the spatial distribution, pollution characteristics, potential pollution sources and ecological risks of heavy metals in the sediments of Chengxi Lake and Chengdong Lake in Huoqiu County in the middle reaches of the Huaihe River Basin, the contents of heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) in the sediments of Chengxi Lake and Chengdong Lake were determined. The potential sources of heavy metals in sediments were quantitatively analyzed by principal component analysis-absolute principal component fraction-multiple linear regression (PCA-APCS-MLR) receptor model. Descriptive statistics showed that the average concentration of heavy metals in lake sediments from high to low was Zn > Cr > Ni > Cu > Pb > As > Cd > Hg, which in Chengxi Lake was higher than that in Chengdong Lake. Geo-accumulation index and pollution load index all indicated that there were moderate pollutions for Cu, As, Hg, Ni and Zn. Comprehensive indexes of potential ecological risks showed that Cd and Hg exhibited the moderate potential ecological risks, the others were low risks. Mean sediment quality guideline quotient indicated that there was a moderate degree of potential adverse biological toxicity in lake sediments. Spatially, the seriously polluted contaminated were the central position of Chengxi Lake and the northeast end of Chengdong Lake. PCA-APCS-MLR revealed that that Cr, Ni, Cu and Zn were mainly from natural sources, while Cd, As, Hg and Pb elements were mainly from industrial sources and pesticide sources.