Effect of Bioaugmentation on Biogas Yields and Kinetics in Anaerobic Digestion of Sewage Sludge

Abstract

Bioaugmentation with a mixture of microorganisms (Bacteria and Archaea) was applied to improve the anaerobic digestion of sewage sludge. The study was performed in reactors operating at a temperature of 35 °C in semi-flow mode. Three runs with different doses of bioaugmenting mixture were conducted. Bioaugmentation of sewage sludge improved fermentation and allowed satisfactory biogas/methane yields and a biodegradation efficiency of more than 46%, despite the decrease in hydraulic retention time (HRT) from 20 d to 16.7 d. Moreover, in terms of biogas production, the rate constant k increased from 0.071 h−1 to 0.087 h−1 as doses of the bioaugmenting mixture were increased, as compared to values of 0.066 h−1 and 0.069 h−1 obtained with sewage sludge alone. Next-generation sequencing revealed that Cytophaga sp. predominated among Bacteria in digesters and that the hydrogenotrophic methanogen Methanoculleus sp. was the most abundant genus among Archaea.

Effect of bioaugmentation on digestate metal concentrations in anaerobic digestion of sewage sludge

“…The enzymes provided by Archaea result in higher reaction rates and reduce the contamination problems [ 44 ]. This was confirmed by the recent study of Lebiocka et al [ 45 ] on the anaerobic digestion of sewage sludge. The authors reported a significant increase in the rate constant of biogas production along with the MAB dose despite the decrease in hydraulic retention time.…”

“…In the present study, the influence of bioaugmentation on total metal concentrations in digestate was examined for anaerobic digestion of sewage sludge. The presented results are the continuation of previously mentioned research [45]. The novel aspect of the work involved evaluating the effect of adding a mixture of wild the bacteria and Archaea from Yellowstone National Park, USA, on the metal contents in the digestate, and determining how it may influence the environment.…”

“…In order to assess the possible toxic impact of metals on the anaerobic digestion process, the biogas yields, VS removal and methane concentration were determined ( Table 2). More detailed information in the field of biogas production, kinetics and process stability is presented in the study performed by Lebiocka et al [45]. The average TS were greatest in R1 (sewage sludge) both in feedstock and digestate: 40.1 and 24.0 g kg -1 , respectively.…”

“…Table 2. Biogas production, methane concentration, and VS removal for runs [45]. (the mean value and standard deviation are given).…”

Genome-Wide and Functional View of Proteolytic and Lipolytic Bacteria for Efficient Biogas Production through Enhanced Sewage Sludge Hydrolysis

“…While microbial consortia may offer a broader degrading potential, they are less biologically stable and controllable than single microbial strains that are hence more often used [9]. The role of bioaugmentation in enhancing methane production was demonstrated for various substrates, which can be grouped into four main categories: sewage sludge [10]; animal manures [11,12]; food industry waste [13,14], and energy crops or agricultural residues [15,16]. These examples are related to studies performed in lab-scale digesters.…”