Landfill leachate coagulation treatment by using Alum, Tapioca starch, and Sago starch

Abstract

Leachate treatment using coagulation process is one of the common methods used in industry. Coagulation is a process of neutralizing the negative charges of the particles in the wastewater by using coagulant to forming larger particles thus easily removed. The aim of this study was to analyze the effectiveness of the alum, tapioca starch and sago starch as to determine the removal efficiency of Chemical Oxygen Demand (COD), Total Suspended Solid (TSS), turbidity, and ammoniacal nitrogen (NH3-N). The leachate was taken from Padang Siding Landfill Site (PSLS) six times (November 2015-January 2016). The jar test was conducted by using alum as main coagulant to determine optimum pH and dosage. Next, determination of involved parameters by using combination of inorganic coagulant (Alum) and natural coagulants (Tapioca starch and Sago starch) under optimized condition. Then, analyze the Sludge Volume Index (SVI) to evaluate the compactness of sludge produced. Data analysis shows that the result on leachate characteristics indicate that PSLS leachate was categorize as intermediate leachate. The optimum pH was result as pH 5 with the removal efficiency of COD (61%), TSS (96%), turbidity (93%), and NH3-N (38%) while the optimum dosage was 1,600 mg/L with removal efficiency of COD (71%), TSS (90%), turbidity (94%), and NH3-N (29%). Next, Sago starch results as more capable coagulant aid since the SVI of Sago starch was 22.0 and Tapioca starch was only 21.6. Overall result shows treatment was less effective when combine alum with natural coagulants which their removal efficiency were alum (71%), alum and sago starch (51.2%), alum and tapioca starch (36%). However, the natural coagulants able to reduce the dosage of alum.