Behavior of sulfate-reducing bacteria in single-stage anaerobic digesters pretreated with ozone

2019-10-28
Tuncay, Sera
Akcakaya, Merve
İçgen, Bülent
Anaerobic digestion is a solid stabilization process commonly used at both municipal and industrial wastewater and sludge treatment. Anaerobic digesters convert the microbiological cells and other solids generated during the treatment process to a stable end product and also produce methane-rich biogas as an energy source through the degradation of organic matter. Microbial population dynamics involved in anaerobic digestion are not well-studied yet due to the requirement of an extensive investigation of microorganisms, their mechanisms and their relations to each other. There are four successive stages of anaerobic digestion as hydrolysis, acidogenesis, acetogenesis and methanogenesis which are governed by hydrolytic microorganisms, acidogens, acetogens and methanogens. Ozone pretreatment to anaerobic digestion promotes the hydrolysis stage by enhancing methane production ability of methanogens. In anaerobic digestion, sulfates and other sulfur oxides are easily reduced to sulfides especially to hydrogen sulfide (H2S) by sulfate-reducing bacteria (SRB). In the presence of sulfate at considerable levels, this sulfate reduction process dominates over methanogenesis since sulfate reducers and methanogens compete for the similar substrates. Besides, H2S as the end-product of the process, has an inhibitory effect to methanogens and other microbial communities because of its toxicity. In this study, 0.03, 0.06 and 0.09 g O3/g TSS ozone doses were applied to single-stage mesophilic anaerobic digesters in order to observe the improvement in methane production. The effects of these ozone doses on SRB and their role in methane production were examined. Community analysis for the sulfate reducers were performed with Fluorescence in situ Hybridization (FISH) method. As a result of the study, sulfate reducers dominated for the digester pretreated with 0.03 g O3/g TSS ozone dose day by day, while sulfate reducers in the other digesters remained same and did not show a significant change during the operation.
4th International Energy & Engineering Congress (UEMK 2019), 24-25 October 2019

Suggestions

Ozonation of sewage sludge prior to anaerobic digestion led to Methanosaeta dominated biomethanation
Tuncay, Sera; Akcakaya, Merve; İçgen, Bülent (2021-01-01)
Anaerobic digestion (AD) of sewage sludge is commonly employed for sludge stabilization and energy generation at wastewater treatment plants. Of pretreatment techniques used to accelerate rate-limiting hydrolysis step in AD, economically feasible ozonation is prevalent and permits sludge reduction via oxidation. The stability of AD process during ozonation is crucial for successful energy recovery and needs optimal dosage that encourages methanogenic consortium efficient in methane production. This study, t...
Effect of ozone pretreatment on methane production and microbial community structure of single-stage anaerobic digesters
Tuncay, Sera; İçgen, Bülent; Department of Environmental Engineering (2021-2-09)
Increasing amount of sludge produced by wastewater treatment plants poses many problems in environmental, public health and economic aspects. Anaerobic digestion (AD), the most common sludge stabilization method, is used to reveal energy potential of sludge as methane-rich biogas. Various pretreatment methods are applied to enhance AD efficiency by facilitating the rate limiting hydrolysis step. Ozone pretreatment is a remarkable method for improving methane production, sludge reduction and pathogen removal...
Two-stage anaerobic digestion of ozonated sewage sludge predominantly took over by acetotrophic methanogens with increased biogas and methane production
Akcakaya, Merve; Tuncay, Sera; İçgen, Bülent (2022-06-01)
Ozonation of sewage sludge prior to single-stage anaerobic digestion (SAD) has been reported to increase biogas and/or methane production. However, no studies have evaluated the impact of ozone pre-treatment on two-stage anaerobic digestion (TAD) of sewage sludge over the production of these renewable fuels. Present study, therefore, aimed at investigating the impact of 0.06 g O3/g TSS ozone-pretreated sewage sludge on the productivity of mesophilic semi-batch lab-scale TAD and on its methanogenic consortiu...
Investigation of methane production potential of industrial sludges mixed with domestic sludge during anaerobic digestion
Aksu Bahçeci, Hazal; Sanin, F. Dilek.; Department of Environmental Engineering (2019)
Anaerobic digestion has been established as a sludge stabilization and biogas production method for domestic sludge. However, anaerobic digestion has limited success in industrial sludge applications. In this thesis sludge from two different Organized Industrial Districts (OIDs) and textile industry are mixed with urban wastewater sludge with and without ultrasound pretreatment to investigate their energy production potential by using BMP tests. Sludges were digested alone (A for industrial, D for domestic ...
Application of ADM1 model to a full-scale anaerobic digester under dynamic organic loading conditions
Ozkan-Yucel, U. G.; Gökçay, Celal Ferdi (2010-01-01)
The IWA Anaerobic Digestion Model No. 1 (ADM1) was used to simulate the full-scale anaerobic sludge digester of Ankara Central Wastewater Treatment Plant. The digester is a completely mixed, once through continuous flow type which is being fed with a primary and secondary sludge mixture. The variability and unpredicted nature of the primary sludge composition was expected to challenge the model. A one-year dynamic data set from the digester was used for model calibration and validation in the study. The sta...
Citation Formats
S. Tuncay, M. Akcakaya, and B. İçgen, “Behavior of sulfate-reducing bacteria in single-stage anaerobic digesters pretreated with ozone,” Gaziantep, Turkey, 2019, p. 546, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/88428.