Detoxification of Leachate by Coagulation Treatment Prior to Fermentation and Possible Reuse in Irrigation

Landfill leachate (LFL) is a very complex effluent that poses considerable threats to humans and to the environment. Selecting the appropriate process for leachate treatment still poses potential concern and challenge for the operation in municipal landfills. The current study aims to assess stabilized leachate degradation through coagulation by using different chemicals (Al2(SO4)3, FeCl3, FeSO4). Thereafter, a complementary process using two Candida strains (Candida kefyr and Candida glabrata) is investigated as a biological treatment of treated LFL. Furthermore, the phytotoxicity of treated LFL is examined by seed germination/root elongation tests using barley and tomato seeds. Upon experimentation and research, the results reveal that the optimum removal efficiency for chemical oxygen demand (COD) and ammonium (NH4+‐N) is 73.3% and 53.5%, respectively, when using the combined process. The removal efficiency of toxic metal elements (Fe, Pb, and Zn) is improved significantly (up to 80%). In addition, physiological and biochemical analyses confirm that the combined process allows a significant toxicity reduction. The obtained outcome is encouraging and supports the possible use of the treated LFL as a fertilizer for plant growth. FeCl3 coagulation combined with biological treatment using a consortium of Candida strains for the removal of pollutants is studied. The process shows good removal efficieny for COD, NH4+‐N, and trace metals. The evaluation for further utilization proves that the treated leachate can be reused as a fertilizer in agriculture.