title: Improvement of anaerobic digestion of waste-activated sludge by using H₂O₂ oxidation, electrolysis, electro-oxidation and thermo-alkaline pretreatments.
abstract: Disintegration of municipal waste-activated sludge (WAS) is regarded as a prerequisite of the anaerobic digestion process to reduce sludge volume and improve biogas yield. Pretreatment of WAS using thermo-alkaline (TA), H2O2 oxidation, electrolysis and electro-oxidation (EO) processes were investigated and compared in term of COD solubilization and biogas production. For each pretreatment, the influences of different operational variables were studied in detail. At optimum conditions, EO gave the maximum COD solubilization (28 %). The effects of pretreatments under the optimum conditions on anaerobic digestion were experienced with biochemical methane potential assay. Significant increases in biogas yield up to 78 and 40 % were observed respectively in the EO and TA pretreated samples compared to raw sludge. Results clearly revealed that the application of EO is a significant alternative method for the improvement of WAS anaerobic digestion.
authors.affiliation: Environmental Bioprocess Laboratory, Centre of Biotechnology of Sfax, BP 1177, 3018, Sfax, Tunisia.
authors.forename: Emna
authors.initials: E
authors.lastname: Feki
authors.affiliation: Environmental Bioprocess Laboratory, Centre of Biotechnology of Sfax, BP 1177, 3018, Sfax, Tunisia. soniakhoufi@gmail.com.
authors.forename: Sonia
authors.initials: S
authors.lastname: Khoufi
authors.affiliation: Environmental Bioprocess Laboratory, Centre of Biotechnology of Sfax, BP 1177, 3018, Sfax, Tunisia.
authors.forename: Slim
authors.initials: S
authors.lastname: Loukil
authors.affiliation: Environmental Bioprocess Laboratory, Centre of Biotechnology of Sfax, BP 1177, 3018, Sfax, Tunisia.
authors.forename: Sami
authors.initials: S
authors.lastname: Sayadi
mesh_terms: D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D056804:Biofuels / Q000032:analysis; D057919:Biological Oxygen Demand Analysis; D004572:Electrolysis; D006358:Hot Temperature; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008697:Methane / Q000737:chemistry; D010084:Oxidation-Reduction; D012722:Sewage / Q000737:chemistry*; D018505:Waste Management / Q000379:methods*
chemical_list: D056804:Biofuels; D012722:Sewage; D006861:Hydrogen Peroxide; D008697:Methane
keywords: Anaerobic digestion; COD solubilization; Electro-oxidation; Thermo-alkaline; Waste-activated sludge