Treatability Study of Partially Stabilized Leachate by Composite Coagulant (Prehydrolyzed Iron and Tapioca Flour)

s. Treatment of leachate before discharge is crucial to ensure the safety of the environment. Application of coagulation-flocculation in reducing pollutant from leachate was proven to be effective. However the use of chemical coagulant will indirectly affect the health of living organisms. To reduce the affect, substitution of the chemical coagulant with natural material can be used. Natural coagulant on leachate treatment was not as effective as chemical coagulant. However, the benefits of natural polymer as coagulants aids had been proven previously. Combination of chemical and natural coagulant as composite coagulant is able to simplify the process and offers many benefits. The aim of this study was to investigate the applicability of composite coagulant made from combination of prehydrolyzed iron (PHI) and tapioca flour (TF) on partially stabilized leachate and was evaluated through percentage removals of suspended solids (SS), colour, chemical oxygen demand (COD) and ammonia. A series of coagulation-flocculation jar test were carried out by considering the effect of dose and pH. Results indicated that at pH 5 and dose 0.2 g/L Fe, the percentage removals of SS, colour, COD and ammonia were 98%, 96%, 60% and 11%, respectively. The results demonstrated that PHITF can be a potential coagulant for the treatment of partially stabilized leachate.