Occurrence and Ecological Risk Assessment of Heavy Metals from Wuliangsuhai Lake, Yellow River Basin, China

As one of the eight largest freshwater lakes in China, Wuliangsuhai Lake is an extremely rare large lake with biodiversity and environmental protection functions world’s arid or semi-arid areas it plays a pivotal role protecting ecological security Yellow River Basin. Heavy metals sediment interstitial water, surface sediments, cores were investigated analyzed, pollution degree evaluated based on multiple assessment methods. The bioavailability heavy sediments was by calculating ratio chemical fractions metals. toxicity water indicated that Ni, Zn, As, Cd would not be toxic to aquatic ecosystems, however, Hg Cr some regions may cause acute benthos. results are heavily polluted main polluting elements Hg. has highest because its high exchangeable fraction ratio. In addition, exogenous accumulated within 20 cm cores, then, increasing depth, risk decreased.