太湖五里湖区表层沉积物中酸挥发性硫化物和同步提取金属

Acid Volatile Sulfides and Simmltaneous Extracted Metals in the Surficial Sediments of Wuli Lake,Lake Taihu

湖泊底泥中的酸溶硫化物易与二价金属生成难溶金属硫化物,从而制约沉积物中二价有毒金属的化学活性以及生物有效性,进而影响沉积物的环境质量.对沉积物中的酸溶硫化物(AVS)和同步提取金属(SEM)进行测定,依据SEM/AVS的比值可以判定重金属生物有效性.通过对太湖五里湖、梅梁湾表层沉积物夏季和秋季AVS与SEM的采样分析,结果表明:研究区域内AVS的含量夏季高于秋季,SEM受季节影响很小,SEM/AVS大于1,且秋季高于夏季,初步判断该湖区沉积物中重金属具有潜在的生物毒性.

Acid volatile sulfides(AVS)in surficial sediments from Wuli lake,Lake Taihu,2002are available for binding with divalent cationic metals through the formation of insoluble metal-sulfide complexes,thereby controlling the metal bioavailability and subsequent toxicity to benthic biocommunities.AVS concentrations and simultaneous extracted metals(SEM)values are determined have become the major research topic asso-ciated with sediments.The ratio of SEM to AVS is promising to predict metal toxicity.From investigated AVS and SEM during summer and autumn at five locations of Lake Taihu,it was found that SEM-AVS values and AVS concentrations did vary significantly between locations during both seasons.AVS concentra-tions were greater during summer than spring;SEM concentrations did not significantly vary between seasons at the same location,which resulting in significantly lower SEM-AVS values in summer.SEM-AVS values were greater than one at each location during both seasons illustrated there might exist heavy metals toxicity in Lake Taihu sediments.