Pollution characteristics and ecological risk assessment of heavy metals in surface sediments of main lakes in Dongxihu district, Wuhan

Abstract

In this work, heavy metals in surface sediments of main lakes in Dongxihu district of Wuhan City were investigated. The results showed that the average concentrations of Zn, Cr, Ni, Cu, Pb, As, Cd and Hg were 108, 103, 45.3, 39.5, 32.3, 15.1, 0.34 and 0.08 mg / kg, respectively. Among them, the pollution level of Jinhu Lake is the most serious. Compared with other lakes in China, the average pollution level of surface sediments in the main lakes of Dongxihu is relatively low. The results of geoaccumulation index method showed that Cd in Dongdahu Lake and Jinhu Lake was in moderate pollution level, while that in Ink Lake and Shangjin Lake was moderate pollution accumulation level. Heavy metals in sediments of other lakes were in light or no pollution level. The potential ecological risk index method showed that the potential risk of heavy metals in the sediments of Jinhu Lake and Dongdahu Lake was at the high ecological risk level, the Ink Lake, Shangjin Lake and Xiayin Lake were at the moderate risk level, and the potential risks of heavy metals in the sediments of other lakes were at the low risk level. Principal component analysis showed that Hg, Cr, Ni, Cu, Zn, CD and Pb might come from industrial and traffic sources, while as might be related to pesticide use.The ecological risk of heavy metals should be considered in the process of endogenous pollution control of Jinhu, Dongdahu, Yinhu, Shangjin and Xiayinhu Lakes.

Keywords

• heavy metals
• urban lakes
• ecological risk
• pollution control