Sonophotocatalytic mineralization of environmental contaminants present in aqueous solutions #21

The wastewater released from the industrial sectors essentially needs the effective technology to avoid the hazardous effects associated with its discharge. The development of low cost and faster processing technology makes the mineralization of the environmental pollutants effective for the large-scale utilization. Various methodologies have been proposed and practiced for its commercialization; however, the generation of secondary pollutants was resulted. The ultrasound-assisted mineralization of environmental contaminants gained the maximum interest from the public and research communities due to its enhanced efficiency of advanced oxidation processes (AOPs). The effective utilization of the ultrasound and its combination with the various AOPs achieved the maximum degradation for the wide spectrum of environmental pollutants and avoids the secondary pollutants generation. The current chapter summarizes the photocatalysis-, sonolysis-, sonocatalysis-, and sonophotocatalysis-assisted degradation of various environmental contaminants via single and coupled AOPs. The degradation of various colored and colorless environmental pollutants is discussed here. Among the AOPs reviewed herein, photocatalysis and sonophotocatalysis techniques were found to be very efficient for the degradation. The intermediates identified from the photocatalytic and sonophotocatalytic degradation of environmental contaminants are similar in most of the studies; however, a few of the intermediates were not observed in other AOP processes which indicates different pathway are followed during the degradation. The reasons for achieving synergy and detrimental effects from the coupled AOPs are analyzed. The development of visible light responsive nanocatalysts reduces the cost required for the commercialization of sonophotocatalysis. The cost estimation analysis was discussed here for the commercialization of the AOP techniques. In addition, recycling of the treated water reduces water consumption of various industries.