Hybrid hydrodynamic cavitation (HC) technique for the treatment and disinfection of lake water

Water reclamation from lakes needs to be accomplished efficiently and affordably to ensure the availability of clean, disinfected water for society. Previous treatment techniques, such as coagulation, adsorption, photolysis, ultraviolet light, and ozonation, are not economically feasible on a large scale. This study investigated the effectiveness of standalone HC and hybrid HC + H2O2 treatment techniques for treating lake water. The effect of pH (3 to 9), inlet pressure (4 to 6 bar), and H2O2 loading (1 to 5 g/L) were examined. At pH = 3, inlet pressure of 5 bar and H2O2 loadings of 3 g/L, maximum COD and BOD removal were achieved·H2O2 was observed to significantly improve the performance of the HC when used as a chemical oxidant. In an optimal operating condition, a COD removal of 54.5 % and a BOD removal of 51.5 % using HC alone for 1 h is observed. HC combined with H2O2 removed 64 % of both COD and BOD. The hybrid HC + H2O2 treatment technique resulted in a nearly 100% removal of pathogens. The results of this study indicate that the HC-based technique is an effective method for removing contaminants and disinfection of the lake water.