h2o2 oxidation of pre-coagulated semi aerobic leachate

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.