Recent Advances in Photoreactors for Water Treatment

Water pollution and wastewater management is a global issue and gaining attention worldwide. Among several other wastewater treatment technologies, photocatalytic treatment is a promising and sustainable approach to recycle wastewater into clean water for various applications. Several semiconductor photocatalysts have been proven successful candidates to convert the toxic organic and inorganic water contaminant molecules into non-toxic molecules under the irradiation of light. Besides several key parameters of photocatalytic reactions (viz. light intensity, pH, photocatalyst concentration, temperature), the selection or designing of a photoreactor also significantly influence the efficiency of photocatalysis. In this regard, several types of photoreactors, such as slurry/membrane/rotatingdrum/annular/closed-loop step photoreactor and microphotoreactor have been designed and employed for wastewater treatment. Heterogeneous, homogenous, and combined photocatalyst systems have been exploited in the reactors to achieve effective photocatalysis. Therefore, knowledge of photoreactor designing and different photocatalyst systems help to scale up the photocatalysis process at an industrial scale. This chapter is mainly focused on the fundamentals of photocatalysis and configurations of different photoreactor for the mineralization of toxic water contaminants.