Optimizing the Disinfection Inactivation Efficiency in Wastewater Treatment: A Computational Fluid Dynamics Investigation of a Full-Scale Ozonation Contactor

The inactivation kinetics of total coliforms to increase the pathogenic removal efficiency in a full-scale ozonation contactor in a wastewater treatment plant in Algeria is investigated. An enhanced ozone contactor design is proposed and 3D multiphase computational fluid dynamics simulations were conducted to optimize the operating parameters, including flow rates, ozone concentrations considering the treatment performance, and total operating cost. The existing design has several limitations, including poor mass-transfer efficiency and uneven distribution of dissolved ozone. To address these issues, the optimized design includes new injection-point settings and an increased number of diffusers. The optimized design achieved a significant improvement in mass transfer efficiency. The ozone treatment effectively reduced the total coliform counts in the wastewater samples compared to the existing design. The Chick-Watson model predicted inactivation kinetics, with a reduction of up to 99.997 %. The practical implications of this research can significantly improve the inactivation kinetics of ozone treatments.