Disinfection of wastewater using TiO2 semiconductor photochemistry

Abstract

There is a raise in concern as shown in recent studies, that when it comes to the traditional wastewater disinfection methods such as chlorination and ozonation, there is a formation of health related disinfection by-products such as trihalomethanes and haloacetic acids that can have carcinogenic tendencies. One of the alternative methods available for commercialization in the near future are advanced oxidation processes, which use semiconductor photochemistry in disinfection. The most effective photo catalyst for these disinfection purposes is TiO2, which is a non-toxic substance that is widely used in products like toothpastes and cosmetics. Traditionally these methods are added as a tertiary or final stage of wastewater treatment, which renders them an additional cost to wastewater systems. In this research, heterogeneous photo catalysis of TiO2 is combined with a pressure driven nanofiltration system, in order to integrate disinfection into a water quality solution and avoid the separation step of methods in order to design a continuous water treatment plan. The objective of the research was to test the inactivation of E. coli bacteria trough photocatalytic disinfection in synthetic wastewater, to determine if the integrated filtration system can be viable in photocatalytic disinfection.