Scale-Up of Photocatalysis-Assisted Water Disinfection: Opportunities and Barriers

Abstract

Dwindling supplies of readily available freshwater, coupled with the continuous growth of the human population, necessitates the purification and reuse of wastewater. This requires next-generation treatment processes, such as advanced oxidative processes (AOPs, e.g., photocatalysis), that offer the ability to remove both harmful microorganisms and other contaminants of emerging concern (CECs) from water. Building upon the laboratory-scale successes of AOPs for the large-scale remediation of water, however, requires process development. To accomplish this goal, a custom-built mobile platform capable of processing 15.14 liters (4 gallons) per minute of water is built and employed for studying the photocatalytic inactivation of Escherichia coli (E. coli) from water. This study indicated that the benchtop setup is as efficient as laboratory-scale studies in disinfecting water by photocatalysis. The study also indicated that catalyst recovery, regeneration and reuse is possible via a combination of gravity-assisted settling, centrifugation and air plasma treatment of the recovered photocatalysts.