Effect of ozone pretreatment on biogas production and microbial community structure of two-stage anaerobic digesters

Akçakaya, Merve
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 throughphysical separation of methane production stages.Various pretreatment applications arealsoused in AD to accelerate therate limiting stage,hydrolysis. Of these, with its strong oxidizing ability ozonationstands out. Therefore, in this study, the effect of ozone pretreatment on TSAD was evaluated in terms of biogas production and microbial population dynamics. For this purpose,two-stage anaerobic digesters wereoperatedafter treatment with previously determined ozone dose of 0.06 g O3/g TSS and monitored in terms of pH, chemical oxygen demand, total nitrogen, solids content, total volatile fatty acids, biogas/methane production and microbial community structure. Biogasand methane production weremonitored through water displacement methodand gas chromatography,microbial consortiumwas monitored through fluorescent in situhybridizationmethod. Methane and biogasproductions were found to be increased69% and 38%, respectively. This increase was accounted for the dominance of Methanosaetaspp.


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Citation Formats
M. Akçakaya, “Effect of ozone pretreatment on biogas production and microbial community structure of two-stage anaerobic digesters,” M.S. - Master of Science, Middle East Technical University, 2021.