Improvement of anaerobic digestion of landfill leachate by using coagulation‐flocculation, Fenton's oxidation and air stripping pretreatments

• Published in: Environmental progress & sustainable energy Vol. 37; no. 3; pp. 1041 - 1049
• Main Authors: Smaoui, Yosr, Mlaik, Najwa, Bouzid, Jalel, Sayadi, Sami
• Format: Journal Article
• Language: English
• Published: 01-05-2018
• Subjects: air stripping; coagulation‐flocculation; fenton oxidation; landfill leachate; methane yield
• ISSN: 1944-7442; 1944-7450
• DOI: 10.1002/ep.12781

In Tunisia, the anaerobic digestion process is regarded as a new alternative for the treatment of landfill leachate (LFL). Raw LFL contained high amounts of organic matter, high ammonia concentrations and low biodegradability. In order to improve anaerobic conditions and biogas yields, pretreatment using coagulation‐flocculation, Fenton oxidation (FO) and air stripping processes were investigated and compared in terms of biogas production. Air stripping process was optimized using Response Surface Methodology (RSM). Central Composite Design (CCD) was used with three factors. Under optimized conditions, removals of 85% ammonia, 26% chemical oxygen demand (COD) were achieved. Coagulation‐flocculation provided an increase in the effluent biodegradability with 46% of COD reduction. Fenton's oxidation allowed reducing 48% COD, 30% of biological oxygen demand (BOD5). The effect of pretreatments was investigated with the biochemical methane potential (BMP) assay. A comparison of three different pretreatment methods of LFL for biogas production was performed. Air stripping was demonstrated as providing a better biogas yield than other pretreatments which reached 588 mL/g CODint. The best methane yield was obtained using air stripping pretreatment under optimized conditions. It can result in more robust and effective anaerobic digestion. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 1041–1049, 2018