自然水体悬浮颗粒物吸附铅和镉的特性

用滤膜过滤方法获取自然水体中的悬浮颗粒物， 研究了其吸附铅和镉的动力学、 热力学特征以及过滤水量、 pH值和离子强度对自然水体悬浮颗粒物对铅和镉吸附的影响. 实验结果表明： 悬浮颗粒物对铅和镉都有明显富集作用， 其对铅的吸附速率和最大吸附量均比对镉的大； 悬浮颗粒物对铅、 镉的吸附量与其质量成正比； 随着吸附体系pH值增大， 悬浮颗粒物对铅的吸附量先增大后减小， 对镉的吸附量则一直增大； 在不同离子强度下进行吸附实验， 结果表明, 悬浮颗粒物对铅和镉的吸附可能同时包括电性吸附和专性吸附.

Adsorption Characteristics of Pb and Cd onto Suspended Particulate Matter

Adsorption of Pb and Cd onto suspended particulate matter, which was obtained from the Nanhu Lake by filtrating with the membrane filter of 0.45 μm, was investigated. The results indicate that the adsorption of Pb onto suspended particulate matter is greater and faster than that of Cd. The adsorption amount of Cd and Pb onto suspended particulate matter increases linearly with the weight of suspended particulate matter. The adsorption amount of Cd onto suspended particulate matter increases with the growth of pH, but the adsorption amount of Pb onto suspended particulate matter increases dramatically when pH is no more than 6.25, and then drops quickly when pH is above 6.25. The results of adsorption experiments of Pb and Cd at different ionic intensities show the possible coexistence of electrostatic adsorption and specific adsorption of Pb and Cd onto suspended particulate matter.