Process of landfill leachate pretreatment using coagulation and hydrodynamic cavitation oxidation

Landfill leachate poses a threat to the environment and human health, and its complex composition made it difficult to treat. Among the methods for treating landfill leachate, the physicochemical combination method is considered to have significant effectiveness, low cost, and application potential. In this study, we propose a new method of coagulation and hydrodynamic cavitation/chlorine dioxide (HC/ClO(2)) for treating landfill leachate. The optimal conditions for coagulation and HC/ClO(2) treatment were investigated experimentally. Under the optimal conditions for coagulation, the COD removal rate was 60.14%. Under the optimal HC/ClO(2) treatment conditions, the COD removal rate was 58.82%. In the combined coagulation and HC/ClO(2) process, the COD removal rate was 83.58%. Thus, the proposed method can significantly reduce the organic load before subsequent biological treatment processes, thereby reducing the operation cycles and cost of biological treatment.