Seasonal Characterization of Landfill Leachate and Effect of Seasonal Variations on Treatment Processes of Coagulation/Flocculation and Adsorption

The aim of this study was to characterize landfill leachate of Çorlu that was heavily industrialized, and to examine the application of coagulation-flocculation and adsorption for the treatment of this leachate. This deposited area is non-regulated and municipal and industrial wastes are deposited uncontrollably. The experiments were conducted to investigate the combined process of coagulation-flocculation and granular activated carbon (GAC) and waste metal hydroxide (WMH) sludge. In this study, ferric chloride and aluminium sulphate were tested as conventional coagulants, and lime was used for pH adjustment. The optimum working pH for the tested coagulants was 9.5. The optimum dosages were 2.4 g/L for Al2(SO4)3 and FeCl3. Among two of the coagulants FeCl3 showed the highest COD removal efficiency (40%) and showed small seasonal variability according to optimum conditions. The adsorption experiments suggested that the optimum dosage of GAC was 18 g/L and WMH was 13 g/L, and the optimum contact time was 12 h. Under the optimum conditions of coagulation/flocculation/GAC adsorption and coagulation/flocculation/WMH adsorption, COD removal efficiencies were respectively 56-63% and 45-48%. Color removal efficiencies were 77-91% and 8192%, respectively. Results of the adsorption study showed that these adsorbents could be used for only color removal for this landfill leachate.