Activated carbon-mediated advanced oxidation process for effective leachate treatment

Leachate, a wastewater produced when rainwater percolates through landfill materials, is a global environmental concern due to its potential to contaminate groundwater and surface water. This study evaluated the use of aerobic-anaerobic, coagulation-flocculation, and advanced oxidation technologies to treat young landfill leachate collected in Chimbo, Ecuador. The treatment process effectively removed high turbidity, dark brown colour, and dissolved organic compounds. Anaerobic biodegradation reduced biochemical oxygen demand (BOD) and chemical oxygen demand (COD) by 60% and 67%, respectively, after 42 days. Coagulation with polyaluminium chloride and ferric chloride effectively removed suspended particles without adjusting the pH. The advanced oxidation process (AOP) using 4 g/L activated carbon and 4000 ppm H₂O₂ achieved 95% COD removal, 96% BOD removal, and 89% colour removal. This study suggests that AOP using activated carbon as a catalyst and H₂O₂ as an oxidant is a promising approach for high colour removal at a moderate cost.