Optimisation of coagulation (poly iron chloride) process for partially stabilised leachate using response surface methodology

A coagulation and flocculation treatment method was applied on partially stabilised leachate of Matang landfill. The interactions and effects of dose and pH on the removal of suspended solid (SS), colour and chemical oxygen demand (COD) were investigated, analysed and optimised through RSM. The optimal condition obtained from the satisfactory mathematical model was 0.24 g/L Fe and 4.94 of poly iron chloride (PHI) dose and pH, respectively. Confirmatory experiment indicates good agreement between model prediction and experimental value. Therefore, RSM is an appropriate statistical tool in the optimisation of PHI coagulation and flocculation process.