HeavyMetalEcologicalRiskinBottomSludgesofYangzongLake,China

张玉玺,刘俊建,陈玺,刘景涛,孙继朝

The concentrations of 10 heavy metals in bottom sludges of Yangzong Lake in Yunnan, China were analyzed. Ecological risk index presented by H?kanson to assess the potential ecological risk of Yangzong Lake was utilized. The results showed that the mean concentrations of titanium, manganese, zinc, vanadium, chromium, copper, nickel, cobalt, lead and arsenic in surface bottom sludges were up to 9413.1, 617.9, 149.2, 189.6, 145.8, 97.6, 55.1, 27.4, 40.3 and 31.4mg/kg, respectively, which are higher than their natural background values. Pearson’s correlation analysis indicated that zinc, chromium, lead and arsenic were highly correlated, and they were originate from activities. Titanium, manganese, vanadium, copper, nickel, and cobalt were also well correlated and mainly from natural factors. The evaluation of pollution index revealed a clear accumulation of the 10 heavy metals, all reaching the level of moderate pollution. Enrichment of arsenic, copper, and chromium was more prominent then other heavy metals. Heavy metals in Yangzong Lake in the descending order of their ecological risks were arsenic, copper, cobalt, nickel, lead, chromium, vanadium, zinc, manganese and titanium. Among them, arsenic was the most prominent factor of ecological risk in bottom sludges of Yangzong Lake.