Biocatalyst immobilized graphene oxide for effluent treatment: Sustainability, efficiency and cost effectiveness

Abstract

Increasing scarcity of potable water resources on a global scale has been recorded in recent times. This has made laws concerning water usage more stringent. These laws have made it imperative to develop novel, efficient, affordable and less time-consuming processes for effluent treatment and subsequent reuse. In the previous decades, processes like chemical oxidation, solvent extraction, coagulation, catalytic degradation, adsorption, biodegradation (aerobic, anaerobic and electrochemical) and membrane-based separation have been widely investigated for decontamination and reclamation of polluted wastewaters. However, most of these processes are unsuitable on their own for wide-scale application due to their huge operational cost, quantity of sludge produced and time consumed for efficient effluent treatment. Thus, contemporary investigations have reported integrated application of different wastewater treatment processes for efficient treatment of effluents bearing a mixture of emerging pollutants. The present study provides a comparative analysis of different integrated processes of wastewater reclamation in terms of their efficiency and cost effectiveness for identification of processes acceptable for sustainable commercial-scale applications. This study reports an integrated biodegradation- adsorption approach for achieving efficient removal of Metanil yellow with reduced treatment time and disposal hazards. In this study, graphene oxide was investigated as a support material for bacterial strain, Dietzia sp. Immobilized microorganisms were found to be more advantageous in comparison to the conventional suspension system as they offered a higher dye removal efficiency, increased biomass, enhanced degradation and strengthened resistance to hazardous pollutants. Besides, the proposed process is highly cost effective with efficient reusability potential. The experimental parameters were optimized using Central Composite Design of Response Surface Methodology. Results proved the efficiency and cost effectiveness of the integrated adsorption and biodegradation approach in removal of azo dyes indicating the possibility of its application for real time effluent treatments.