Degradation of Recalcitrant Textile Dyes by Coupling Fungal and Photocatalytic Membrane Reactors

Abstract

White rot fungi have powerful and broad specific extracellular enzymatic systems and can degrade multiple types of recalcitrant compounds including azo dyes, therefore, they are used in the field of bioremediation. In the present study, decolorization and organic matter removal of Acid Red 88 (AR88) and Reactive Red 180 (RR180) dye solutions were performed using the white rot fungus Phanerochaete chrysosporium in a bioreactor. Degradation of the dyes was assessed using a hybrid process consisting of a fungal membrane bioreactor coupled with a photocatalytic membrane reactor. The photocatalytic oxidation step was conducted using the semiconductor ZnO as the catalyst with UVA irradiation. Experimental data with the fungal membrane bioreactor showed that the optimum pH was 4.5 for P. chrysosporium. Integrating photocatalytic step after the fungal membrane process improved the chemical oxygen demand (COD) removal efficiency up to 98 and 96% for RR180 and AR88 dye solutions, respectively. Color removal efficiencies after the photocatalytic degradation were 99.9% for both dye solutions.