Effect of ozone pretreatment on methane production and microbial community structure of single-stage anaerobic digesters

Tuncay, Sera
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. Therefore, this study investigated the effect of ozone pretreatment with varying doses of 0.03, 0.06 and 0.09 g O3/g TSS on methane production and microbial communities of mesophilic single-stage anaerobic digesters operated as semi-batch. Anaerobic digesters were monitored in terms of pH, temperature, chemical oxygen demand, total nitrogen, solids content, total volatile fatty acids, methane production and microbial community structure. Changes in methane and microbial community structure were determined by gas chromatography and fluorescence in situ hybridization (FISH) methods, respectively. Pretreatment with 0.06 g O3/g TSS resulted in 47% methane increase by achieving the highest methane content of 78%. FISH analyses revealed that Methanosaeta spp. were the most dominant methanogens in this pretreated digester.


Effect of ozone pretreatment on biogas production and microbial community structure of two-stage anaerobic digesters
Akçakaya, Merve; İçgen, Bülent; Department of Environmental Engineering (2021-2-09)
The amount of sludge produced in treatment plants is increasing depending on the population growth and water consumption. Anaerobic digestion (AD) is a widely used sludge stabilization method in wastewater treatment plants, as it provides volume reduction and methane-rich biogas production. In single-stage anaerobic digestions, the process fails due to volatile fatty acid accumulation and pH changes. To solve this problem, two-stage anaerobic digestion (TSAD) process has emerged t...
Effects of anaerobic digestion on the combustion of sewage sludge
Çelebi, Emrehan Berkay; Aksoy, Ayşegül; Sanin, Faika Dilek (2016-06-10)
Around the world, especially in the developing countries, sludge management is a topic gaining increasing importance, as the number of treatment plants and the people connected to these plants are on the rise. Old approaches seeing sludge as a waste, including landfilling, leave its place for new applications where sludge acts as an energy source or a resource as fertilizer. Combustion or co-combustion of sludge exploits its energy potential while providing stabilization ...
Behavior of sulfate-reducing bacteria in single-stage anaerobic digesters pretreated with ozone
Tuncay, Sera; Akcakaya, Merve; İçgen, Bülent (null; 2019-10-28)
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 mi...
Effects of pretreatment methods on solubilization of beet-pulp and bio-hydrogen production yield
Ozkan, Leyla; Bayramoğlu, Tuba Hande; DEMİRER, GÖKSEL NİYAZİ (2011-01-01)
Sugar processing wastewater and beet-pulp are two major waste streams of sugar-beet processing plants. Contrary to wastewater, beet-pulp is generally used as animal feed in cattle-raising industry. However, it can serve as a substrate for bio-hydrogen production which corresponds to a higher valorization of beet-pulp. Moreover, pretreatment of lignocellulosic materials like beet-pulp is needed in order to improve overall energy efficiency and enable economic feasibility of bio-hydrogen production. Therefore...
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...
Citation Formats
S. Tuncay, “Effect of ozone pretreatment on methane production and microbial community structure of single-stage anaerobic digesters,” M.S. - Master of Science, Middle East Technical University, 2021.