潮间带沉积物中重金属的AVS归一化研究

Study of Acid Volatile Sulfide (AVS) and Simultaneously Extracted Metals (SEM) in Clayey Tidal Zone Sediments

采集胶州湾河套镇养殖区潮间带高、中、低潮带的沉积物样品 ,将重金属 AVS归一化法应用于粘土质潮间带沉积物研究 ,测定了酸可挥发硫 (AVS)和酸化过程中溶解释放的重金属 (SEM) ,并根据 SEM与 AVS的摩尔浓度关系评价二价重金属 (Cu、Pb、Zn、Cd、Ni)的化学活性和生物可获得性。结果表明 :河套镇养殖区除各潮带表层 0～ 2 cm外 ,SEM/ AVS均小于 1,重金属的生物活性小 ,不会对养殖的底栖生物造成影响。 8cm以下 AVS平均含量高潮带 >中潮带 >低潮带 ,在同一潮位 AVS随深度增加而增加 ;相同潮位的

It is well known that AVS plays an important role in influencing the toxicity of divalent cationic metals in anoxic sediments. By studying the column samples collected from the tidal znoe of Jiaozhou Bay, it is found that the concentration of acid volatile sulfide gradually increases with depth, and it decreases from high tide land. to midst tide land and to low tide land. We evaluate the chemical activity and bioavailability of heavy metals in the tidel zone of Jiaozhou Bay based on the molar ratio of Simultaneously Extracted Metals (SEM) to AVS. The concentration the SEM appear highest at the boundary of the redox layer. SEM/AVS is mostly less than 1 in this area except the surface layer, which suggests that the heavy metals appear to be of no activity or bioavailability.