Transport of metal ions in hydrogels containing humic acids as active complexation agent

abstract

English

The complexation and transport/immobilization ability of humic acids are the most important environmental qualities of these substances. Therefore, the study on these properties are important both for understanding role of their role in natural systems and human-driven applications. This contribution is focused on metal ions diffusion (Co, Cu and Ni) studyied by the method of diffusion couple [1] and their immobilization in humic hydrogels. It was found that the diffusion characteristics of metal ions are strongly affected by their reactivity and their initial concentration. Concentration dependence of Cu diffusivity had different trend comparing Co and Ni, which was caused by high affinity of Cu to humic acids. When the metal ion is first complexed by humic acids, it is bound in an exchangeable mode, which can be transferred to a nonexchangeable one. Our results indicated that the dynamic equilibrium established in the diffusion process includes mainly Cu ions in the exchangeable mode as a result of their high affinity and high amount of bound metals. Their transformation in strong Cu-humic complexes is very slow. On the other hand, Co and Ni had much lower affinity to humic acids, thus their diffusivity is less affected by their reaction with humic acids. Acknowledgements

hydrogel; humic acids; complexation; diffusion

KLUČÁKOVÁ, M.

1. 9. 2017

European Colloid and Interface Society and Complutense University of Madrid

Madrid

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