Two-phase anaerobic digestion of semi-solid organic wastes

Download
index.pdf
2008
Doğan, Eylem
Show full item record
256
views
111
downloads
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 (OLR) of 15 g VS/L.day, pH value of 5.5 and hydraulic retention time (HRT) of 2 days were determined to be the optimum operational conditions for the acidification step. Maximum total volatile fatty acid and average acidification percentage were determined as 12405 mg as HAc/L and 28%, respectively in the reactor operated at optimum conditions. In the second part, an acidification reactor was operated at the optimum conditions determined in the first part. The effluents taken from this reactor as well as the waste stock used to feed this reactor were used as substrate in the biochemical methane potential (BMP) test. The results of BMP test revealed that the reactors fed by acidified samples indicated higher total chemical oxygen demand (tCOD) removals (39%), VS reductions (67%) and cumulative gas productions (265 mL). The result of this study indicated that the separation of the reactors could lead efficiency enhancement in the systems providing that effective control was achieved on acidified reactors.
Acidogenesis., Environmental Engineering.
http://etd.lib.metu.edu.tr/upload/3/12609280/index.pdf
https://hdl.handle.net/11511/17517
Graduate School of Natural and Applied Sciences, Thesis

Suggestions

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; Sanin, Faika Dilek; Department of Environmental Engineering (2008)
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 mi...
Assessment of diffusive and convective mechanisms during carbon dioxide sequestration into deep saline aquifers
Özgür, Emre; Gümrah, Fevzi; Department of Petroleum and Natural Gas Engineering (2006)
The analytical and numerical modeling of CO2 sequestration in deep saline aquifers having different properties was studied with diffusion and convection mechanisms. The complete dissolution of CO2 in the aquifer by diffusion took thousands, even millions of years. In diffusion dominated system, an aquifer with 100 m thickness saturated with CO2 after 10,000,000 years. It was much earlier in convective dominant system. In diffusion process, the dissolution of CO2 in aquifer increased with porosity increase; ...
Two-Phase Thermophilic Acidification and Mesophilic Methanogenesis Anaerobic Digestion of Waste-Activated Sludge
Demirer, Göksel Niyazi; Othman, Maazuza (Mary Ann Liebert Inc, 2008-01-01)
Biological pretreatment methods of waste-activated sludge (WAS) have recently received attention because of their efficiency and relatively low investment. The application of hydrolysis/acidification step before methanization in anaerobic digestion or the two-phase anaerobic digestion process constitutes one of these methods. Two phase (thermophilic acidification and mesophilic methanogenesis) anaerobic digestion of WAS was investigated and reported to perform better in terms of chemical oxygen demand (COD)...
Biorefining of sugar-beet processing wastes by anaerobic biotechnology: waste stabilization and bioproduct formation
Alkaya, Emrah; Demirer, Göksel Niyazi; Department of Environmental Engineering (2008)
The main objective of this study was to investigate two of the possible exploitation routes of anaerobic digestion (acid-phase and methane-phase) for the treatment of sugar-beet processing wastes, while producing valuable biobased products. For this purpose, four sets of laboratory experiments were carried out in a stepwise fashion: First, in the biochemical methane potential (BMP) assay (Set-up 1) wastewater and beet-pulp were efficiently digested (63.787.3% COD removal and 69.689.3% VS reduction) in batch...
An Environmental philosophical analysis of ecosystem health
Saraç, Yüksel; Sol, Ayhan; Department of Philosophy (2019)
The aim of this study is to qualify the notion of ecosystem health by taking the origin of the 'health' concept into consideration and discuss how to find solutions to some environmental problems, arising from the combination of the individual terms of ‘ecosystem health’. With this intention, I evaluate the ethical theories of leading environmental philosophers about ecosystem health through an analytical inquiry.
Citation Formats
E. Doğan, “Two-phase anaerobic digestion of semi-solid organic wastes,” M.S. - Master of Science, Middle East Technical University, 2008.
METU IIS - Integrated Information Service open@metu.edu.tr