重金属在自然水体生物膜上的竞争吸附

Competitive Adsorption of Metal Cations onto Natural Surface Coatings

研究了用长春南湖培养的生物膜吸附重金属过程中镉、钴、铅、镍和铜5种重金属两两共存及5种金属共存时金属间相互影响的情况. 结果表明, 自然水体生物膜对镉、钴、铅、镍和铜吸附时, 金属两两之间相互干扰, 使生物膜对重金属的吸附量有所降低, 其中镍和钴之间的相互作用最显著. 在5种金属共存时, 金属之间影响增大, 但小于两两金属干扰强度的叠加; 而且生物膜对金属的选择性吸附顺序与金属单独存在时生物膜对它们的吸附顺序一致.

The adsorption behaviors of Pb, Cd, Cu, Co and Ni onto natural surface coatings (biofilms and associated minerals, collected in the Nanhu Lake, Changchun, China) with and without competing metal ions were examined in this study. The results show that there is always competition between the two metals in the binary systems, especially between Ni and Co. In the system of all the five metals present, the interference of adsorption among the five metals is more significant than those in the binary systems. But for each metal, this reduction of adsorption capacity is less than the summary of the interfering effects of two metals calculated from the binary systems. The results also indicate that the adsorption sequence of these metals onto surface coatings in the five metal system is in agreement with that of in single metal system.