School of Civil Engineering, 14300, Nibong Tebal, Universiti Sains, Malaysia
School of Housing, Building and Planning, 11800, Minden, Universiti Sains, Malaysia
Heavily polluted wastewater from sanitary landfill presents the leachate characteristics that need special treatment and disposal. Concentration of chemical oxygen demand (COD), ammonia nitrogen (NH3-N), heavy metal and other pollutant content are often larger than standard requirement after applying biological/physico-chemical treatment.Thus, the combination of coagulationflocculation and chemical oxidation treatment has been investigated. Using the jar-test procedure and stirrer, the physico-chemical conditions were optimized. It concerns the most effective coagulant between ferric chloride (FeCl3) and poly-aluminum chloride (PACl), the optimal pH and the H2O2 as the most effective chemical oxidant. The optimum pH and dosage of PACl and FeCl3 were obtained as 7 and 2.0 g/L, 5 and 1.0 g/L respectively. Iron salts were proved to be more efficient than aluminum ones, resulting in COD reduction (up to 59%) whereas the corresponding values using alum was lower (50%). The optimum pH and dosage of PACl and ferric chloride for optimum oxidation process was; 300 mg/L at pH7 and 300 mg/L at pH 6 respectively. Oxidation process gave significant effect to the removal of suspended solids and turbidity (up to 94%) using supernatant contain with ion Fe3+ at pH 7.