Sludge characterization of coagulation/flocculation of leachate by using different ratio of composite coagulant (PACTF)

Abstract

Landfill leachate is considered as a highly polluted liquid that is produced from infiltration of water through municipal solid waste. This study investigated the effectiveness of composite coagulant used in removing total suspended solid (TSS) of leachate through coagulation-flocculation process and characterized the sludge produced by determining its sludge volume index (SVI), sludge settling rate (SSR), and morphology of sludge using SEM. The composite coagulant used was PACTF that combined chemical (polyaluminium chloride) and natural coagulant (tapioca flour). With ratio TF/PAC of 0.38 and dosage of PACTFb of 168.9 mg/L Al, the TSS percentage removal was 97.4%. While, the SVI and SSR of sludge were 461.5 ml/g and 1.73 cm/min, respectively. The size of sludge particle for PACTFb was in the range of 20 µm to 50 µm. Addition of TF into PAC as composite coagulant improved the sludge formation.