Biogas generation by hybrid treatment of dairy wastewater with lipolytic whole cell preparations and anaerobic sludge

• Published in: Biochemical engineering journal Vol. 169; p. 107965
• Main Authors: Ferreira, Tainá F., Santos, Patrick A., Paula, Ariela V., de Castro, Heizir F., Andrade, Grazielle S.S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-05-2021
• Subjects: Biogas; Dairy wastewater; Lipase; Penicillium citrinum; Whole cell; Dairy wastewater; Biogas; Whole cell; Lipase; Penicillium citrinum
• ISSN: 1369-703X; 1873-295X
• DOI: 10.1016/j.bej.2021.107965

•The biochemical methane production were obtained from dairy wastewater treatment.•A hybrid dairy wastewater treatment (enzymatic/biological) were investigated.•The whole cells of Penicillium citrinum were cultivated in agroindustrial wastes.•A high cumulative methane production was reached after 45 h of treatment.
This study aimed to assess the potential of the biochemical methane production and biodegradability of dairy wastewater employing a hybrid treatment: granular anaerobic sludge as inoculum and whole cells of Penicillium citrinum with high lipase activity. It was expected that mycelium-bound lipase from whole cells would enhance hydrolysis, contributing to the efficiency of anaerobic digestion by granular inoculum. Seven substrate and microbial combinations were prepared; five contained the inoculum and whole cells cultivated in different agroindustrial wastes and two were controls (inoculated and uninoculated). A synergistic microbial interaction was evidenced by the high cumulative methane production after 45 h of reaction, reaching 231 mL g−1 volatile solids. pH was maintained at values near neutrality in all treatments, and chemical oxygen demand removal ranged from 42 to 57 % in hybrid treatments. First-order and modified Gompertz kinetic models were fitted to experimental data, and a lag phase was not observed. The results show the potential of hybrid treatment of dairy wastewater with whole cells produced in waste-based media for biogas production.