博斯腾湖沉积物中的酸可挥发性硫化物

Acid Volatile Sulfide in Sediments of Bosten Lake

沉积物中的酸可挥发性硫(AVS)易与二价金属结合生成难溶金属硫化物(MeS),进而制约二价有毒金属的化学活性和生物可利用性。通过测定AVS和同步提取金属(SEM),依据SEM/AVS的比值可判定沉积物中二价重金属的活性。文章对新疆博斯腾湖大、小湖区沉积物样品进行了分析,结果表明:AVS的含量受进水水质和人为活动影响较大,SEM的分布也有类似的分布特征。各采样点表层沉积物SEM/AVS比值均<1,说明沉积物中二价金属的化学活性和生物可利用性都较低。AVS的垂直分布随着深度的增加先降低后略有升高;SEM随深度的加深呈逐渐降低趋势。与太湖相关的研究结果对比发现,博斯腾湖AVS含量高于太湖五里湖区,而SEM低于太湖。

Acid volatile sulfides（AVS） in sediments are available for binding with divalent cationic metals through formation of insoluble metal-sulfide complexes, thereby controlling metal bioavailability and subsequent toxicity to benthic biocommunities. AVS concentration and simultaneous extracted metals （SEM） values were determined to predict metal toxicity. From investigation of AVS and SEM in Bosten Lake, Xinjiang, it was found that SEM and AVS have the same characters. By comparing spatial distribution, it was found that AVS first increased and then decreased with depth while SEM decreased with depth.