Abstract
In the current study, a visible light catalyst g-C3N4 was prepared and evaluated to be applied as a pretreatment process to enhance the biodegradability of organic pollutants in Cheese Whey wastewater. The photocatalysis pretreatment was performed using the solar photo chemical reactor for a duration of 8-9 hours, and the optimization of the process was evaluated under varying catalyst types such as traditional TiO2 and visible light g-C3N4, application dose of catalyst and pH of the system. The results indicated that g-C3N4 achieved the most promising results in terms of solubilization of insoluble fats and protein of cheese whey wastewater. The application dose of 0.75g/L and pH 5-6 showed the most acceptable results where soluble COD was 7876 mg/L and 7976 mg/L which were achieved from the initial values of 5765 mg/L. The follow up reaction of aerobic digestion which was performed in the continuous mixing aerobic (CMA) bioreactor for a duration of 70 day, revealed the efficient performance in terms of tCOD degradation. The lowering of tCDO from 8078 mg/L to 432 was achieved with the pretreated cheese whey wastewater in comparison with the untreated wastewater, where tCOD was lowered to 2634 mg/L. Similarly, a considerable improvement in other water quality parameters such as Nitrogen, pH, EC, sulfates, alkalinity and, oil and grease was achieved with the pretreated cheese whey wastewater. It has been concluded that, this study has a great potential to be applied at the industrial level as the pretreatment process is simple and highly economical due to its dependence on the freely available solar light.