【摘要】 为探讨河蚬扰动对沉积物中重金属生物有效性与毒性的影响,制作重金属污染的不同质地沉积物(不同有机质含量和不同砂质含量)样品,采用室内模拟并借助间隙水平衡(Peeper)和薄膜扩散梯度(DGT)原位测定手段,试验研究了河蚬扰动作用下沉积物中重金属生物有效性以及毒性的变化特征。结果表明:河蚬扰动促进沉积物中重金属离子向上覆水释放,使上覆水中的Cd质量浓度增大了2%～12%,As增大了2%～198%;河蚬扰动使Cd、As的活性增大,在砂质沉积物中的活性大于有机质沉积物中的活性;河蚬扰动可促使沉积物中酸可挥发性硫化物的含量降低,进而改变其对沉积物中亲硫金属的结合能力,增强了沉积物中重金属的毒性。更多还原

【Abstract】 In order to investigate the effects of Corbicula fluminea disturbance on the bioavailability and toxicity of heavy metals in sediments,making different sediment samples(different organic matter content and different sandy content)polluted by heavy metals,indoor simulation and in-situ measurement of gap water balance(Peeper) and diffusion gradient in thin film(DGT) are adopted to study the changes in bioavailability and toxicity of heavy metals in sediments under disturbance of Corbicula fluminea.The results show that the disturbance of Corbicula fluminea promotes release of heavy metal ions from sediments to the overlying water,making Cd in the overlying water increased by 2%～12% and As increased by 2%～198%.The disturbance of Corbicula fluminea increased the activity of Cd and As,and the activity in sandy sediments is greater than that in organic sediments.Disturbance of Corbicula fluminea can reduce the content of acid volatile sulfide in the sediments,changing the binding capacity of the thiophilic metal in the sediments,and enhancing the toxicity of the heavy metal in the sediments.更多还原