Effective degradation and detoxification of landfill leachates using a new combination process of coagulation/flocculation-Fenton and powder zeolite adsorption

The aim of this work was to examine the application of an integrated technique that consisted of coagulation/flocculation-Fenton-powder zeolite adsorption methods for the treatment of raw leachates from a landfill site of Bizerte (Northern Tunisia). The coagulation–flocculation process showed a moderate chemical oxygen demand (COD) removal efficiency (RE) (54%) and high turbidity RE (94%). The Fenton experiments suggested that the dosage of 1.2g L−1 of Fe2+ and 2.8g L−1 of H2O2 at pH 3 were the appropriate working conditions. Under these conditions, COD value was higher than the legal limits for discharge throughout the local municipal sewage. To achieve a satisfactory removal of pollutants, adsorption experiments were also carried out using 30 g L−1 of powder zeolite. The removal efficiencies of COD, ammonia, iron, and aluminum were 97, 91, 99, and 97%, respectively. The phytotoxicity test showed that combined treatment process allowed a significant toxicity removal up to 90%.