Removal of metal and organic pollutants from wastewater by a sequential selective technique

Abstract

In this study the application of a sequential selective system that combined biosorption with biodegradation was evaluated as a feasible process for the removal of Cr(VI) and m-cresol from effluents. Cr(VI) biosorption on pretreated chestnut shells showed 100% metal removal and modelling efforts demonstrated that the pseudo-second order kinetic model and Langmuir isotherm fit well the process behaviour. Thus, the treated stream was an appropriate environment for the biodegradation of m-cresol using a laccase-producer fungus, Phlebia radiata. Two bioreactor configurations, rotating drum and modified-airlift, were studied using the fungus grown on chestnut shells, which act as support-substrate as well as oxidative enzyme inductor increasing the laccase activity up to 1000UL−1. The best bioreactor, rotating drum, reached 100% removal in 7days. Finally, the best configuration for the sequential selective system was modelled operating in continuous mode by the breakthrough curves generated using FASTv2.0 and the design bioreactor flow model.