Combination of alkaline solubilization with microwave digestion as a sludge disintegration method: effect on gas production and quantity and dewaterability of anaerobically digested sludge

Doğan, Ilgın
The significant increase in the sewage sludge production in treatment plants makes anaerobic digestion more important as a stabilization process. However hydrolysis is the rate-limiting step of anaerobic digestion because of the semirigid structure of the microbial cells. Pretreatment of waste activated sludge (WAS) leads to disruption of cell walls and release of extracellular and intracellular materials. Therefore biodegradability of sludge will be improved in terms of more biogas production and sludge minimization. Among the pretreatment methods, alkaline, thermal and thermochemical pretreatments are effectual ones. Considering the effect of thermal pretreatment, microwave technology in which the sample reaches to elevated temperatures very rapidly is a very new pretreatment method. However no previous research has been conducted to test the effectiveness of microwave (MW) irradiation combined with alkaline pretreatment. Since both of these techniques seem to be highly effective, their combination can act synergistically and even more efficient method can be obtained.


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The objective of this study is to illustrate that phase separation improves the efficiency of an anaerobic system which digests semi-solid organic wastes. Organic fraction of municipal solid waste (OFMSW) was the semi-solid organic waste investigated. In the first part of the study, the optimum operational conditions for acidified reactor were determined by considering the volatile solid (VS) reductions and average acidification percentages at the end of two experimental sets conducted. Organic loading rate...
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Anaerobic digestion (AD) is an effective way to convert animal manures into profitable by-products while simultaneously reducing, the pollution of water, air, and soil caused by these wastes. Conventional high-rate anaerobic reactors cannot effectively process animal manures with high solids-containing wastes. The two-phase configuration for AD has several advantages over conventional one-phase processes, e.g., increased stability of the process, smaller size and cost efficient process configurations. In th...
Citation Formats
I. Doğan, “Combination of alkaline solubilization with microwave digestion as a sludge disintegration method: effect on gas production and quantity and dewaterability of anaerobically digested sludge ,” M.S. - Master of Science, Middle East Technical University, 2008.