Quantitative Analysis of Copper Biosorption by the Microalga Chlorella vulgaris

摘要

In this study we have investigated the kinetics of copper removal by inactivated biomass of Chlorella vulgaris, a green microalga, in batch systems. A dual resistance rate model incorporating intrinsic adsorption kinetics and film diffusion was used to assess the relative importance of the two rate processes under varying experimental conditions. Intraparticle diffusion was not accounted for in this model since metal uptake by nonliving algal biomass is a passive nonmetabolically mediated process and is, therefore, a surface binding phenomenon. Modeling results have found that film diffusion appears to be the rate-limiting step at low initial metal concentrations. On the other hand, both the intrinsic adsorption kinetics and film diffusion are likely to control the overall rate of adsorption at high initial metal concentrations. The model described in this study can thus be used for predicting if and under which conditions the metal adsorption process could sufficiently be described by single resistance models.