Solar photocatalytic oxidation and disinfection of municipal wastewater using advanced oxidation processes based on pH, catalyst dose, and oxidant

There are great interests in photocatalytic oxidation of contaminants using advanced oxidation processes (AOP) based on photocatalytic oxidation in recent years. The main aim of the paper is to develop a method which takes care of energy and water conservation together. The study was performed on photocatalytic disinfection of total coliform (TC) bacteria as water microbial pollution and reducing the chemical oxygen demand (COD) as organic pollution index using catalytic and oxidant in present of sun light. The municipal wastewater was monitored for TC and in then was irradiated with solar light, solar light/TiO₂, and solar light/TiO₂/H₂O₂. Various parameters such as contact time, pH, and different concentration of TiO₂ and H₂O₂ were studied for their effect on reaction process. The result showed that in presence of solar light, catalyst, and oxidant, very effective disinfection and reduction of TC and COD took place. 95.2% and 97% of TC and COD were reduced by irradiation for 240-300 min. Based on the results of various AOP combinations, Solar photolytic, solar/TiO₂, Solar/TiO₂/H₂O₂, the rate of COD, and TC removal was in the order of TiO₂/H₂O₂ > TiO₂ > Solar photolytic. It can be suggested as an effective treatment method for wastewater containing microbial and organic contamination.