Guibaud Gilles, van Hullebusch Eric, Bordas François, d'Abzac Paul, Joussein Emmanuel
Université de Limoges, Groupe de Recherche Eau Sol Environnement, Faculté des Sciences et Techniques, 123, Avenue Albert Thomas, 87060 Limoges Cedex, France.
Bioresour Technol. 2009 Jun;100(12):2959-68. doi: 10.1016/j.biortech.2009.01.040. Epub 2009 Feb 28.
The present study deals with the sorption of Cd(II) and Pb(II) by exopolymeric substances (EPS) extracted from activated sludges or pure bacterial strains. The percentage of sorbed metal increases with the concentration of the EPS-water solution. Pb(II) always presents a higher affinity than Cd(II) for EPS. For the EPS extracted from pure bacterial strains, only one global binding constant from a simple equilibrium sorption model, may be used to assess the effect of microbial products such as EPS on Cd(II) and Pb(II) speciation or mobility in the environment. However, for EPS extracted from activated sludges, the wide variation of the global binding constants determined for Cd(II) and Pb(II) do not permit such a simple approach. The differences in sorption to metals between the two types of EPS (bacterial, activated sludges) could be explained by the differences in EPS composition: organic macromolecules, as well as the nature of the mineral fraction.
本研究探讨了从活性污泥或纯细菌菌株中提取的胞外聚合物（EPS）对Cd(II)和Pb(II)的吸附作用。被吸附金属的百分比随EPS水溶液浓度的增加而增加。Pb(II)对EPS的亲和力总是高于Cd(II)。对于从纯细菌菌株中提取的EPS，一个简单平衡吸附模型中的单一全局结合常数可用于评估微生物产物（如EPS）对环境中Cd(II)和Pb(II)形态或迁移率的影响。然而，对于从活性污泥中提取的EPS，针对Cd(II)和Pb(II)测定的全局结合常数变化很大，无法采用这种简单方法。两种类型的EPS（细菌型、活性污泥型）对金属吸附的差异可以通过EPS组成的差异来解释：有机大分子以及矿物成分的性质。
