A detailed analysis of process optimization for ozone-based processes for water treatment

This study strategically analyses the available literature on ozonation and catalytic ozonation processes while also considering the Fenton process as a representative advanced oxidation process (AOP) for the comparative evaluation of process optimization strategies for dye-containing wastewater. The objective of this work was to identify the most influential operating parameters governing dye degradation and to establish generalized optimization trends reported in the literature. Response surface methodology (RSM)-based statistical analysis was employed to evaluate published optimization studies and identify the significant operating variables. Industrial effluents are complex mixtures of dyes, inorganic ions, and organic constituents, making it difficult to identify the critical parameters governing treatment efficiency. In this work, significant process parameters, including initial dye concentration, pH, temperature, ozone dose/concentration, catalyst dose, hydrogen peroxide concentration, and contact time, were analysed, and their optimum operating ranges were identified using RSM. The analysis showed that the initial concentration of pollutant and ozone dose were the governing parameters of ozonation performance, while catalyst dose had a significant impact on catalytic ozonation. The concentration of hydrogen peroxide was the most significant operating parameter for the Fenton process. The literature compiled and the statistical interpretation of it provide a generalised understanding of the behaviour of the optimization in these oxidation processes and indicate the operating variables that most influence the pollutant removal. The results can serve as a good reference for future laboratory and pilot-scale optimization studies, and may support the development of more efficient and sustainable wastewater treatment processes. However, the observed optimization trends should be considered as preliminary guidelines and further validation is required with real industrial wastewater under practical operating conditions.