Print Email Facebook Twitter Effects of mild thermal pre-treatment combined with H2O2 addition on waste activated sludge digestibility Title Effects of mild thermal pre-treatment combined with H2O2 addition on waste activated sludge digestibility Author Gonzales, A. (TU Delft Sanitary Engineering) van Lier, J.B. (TU Delft Sanitary Engineering) de Kreuk, M.K. (TU Delft Sanitary Engineering) Date 2022 Abstract The pre-treatment of waste activated sludge (WAS) has become more common since it often results in improved bioconversion to methane, in both rate and extent. However, thorough insights on the possible effects and mechanisms of mild pre-treatment techniques, such as temperatures <100 °C combined with the addition of H2O2, are still limited. This study reports the effects of the addition of 5–30 mgH2O2/g TS and its interaction with thermal pre-treatment at 70 °C on methane production, using WAS as the substrate. It was found that the addition of H2O2 increased the methane production rate, coinciding with a decrease in apparent viscosity of WAS, which probably improved mass transfer under non-ideal mixing conditions. While H2O2 solubilized proteins and carbohydrates and mineralized a small fraction of the humic substances in WAS, these biochemical transformations did not suffice to explain the observed extent and rate of methane production. A decreased particle size, the presence of Fenton's reagent, and the presence of cationic polymers in the WAS were discarded as the reasons for the observed decrease in apparent viscosity. It was concluded that the pre-treatment conditions applied in the present study might be a strategy to enhance mixing conditions in full-scale anaerobic digesters. Subject Apparent viscosityCatalase activityCationic polymerHydroxyl radicalsLow-temperature pre-treatmentNon-ideal mixing To reference this document use: http://resolver.tudelft.nl/uuid:684c9a7e-884c-47aa-91e5-fb562bf6f743 DOI https://doi.org/10.1016/j.wasman.2022.01.017 ISSN 0956-053X Source Waste Management, 141, 163-172 Part of collection Institutional Repository Document type journal article Rights © 2022 A. Gonzales, J.B. van Lier, M.K. de Kreuk Files PDF 1_s2.0_S0956053X22000186_main_1.pdf 4.55 MB Close viewer /islandora/object/uuid:684c9a7e-884c-47aa-91e5-fb562bf6f743/datastream/OBJ/view