Volatile Fatty Acids Production through Degradation of Biomass by Anaerobic Digestion (Mesophilic and Thermophilic)

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Abstract:

Volatile fatty acids (VFAs) are fatty acids with a carbon chain of six carbons or fewer and usually referred to as short-chain fatty acids (SCFA). Degradation of biomass through anaerobic digestion will produce volatile fatty acid (VFAs) through anaerobic digestion process. The volatile fatty acids obtained can be recovered and used to produce methyl or ethyl esters which, could be advantageously used as additive for biodiesel [1]. Anaerobic digestion is a biological process that can degrade waste organic material by concerted action of a wide range of microorganisms in the absence of oxygen. The objective of this study is to degrade the biomass through anaerobic digestion for the production of volatile fatty acids by two different temperatures condition which are mesophilic and thermophilic; 35°C and 55°C respectively. The production of volatile fatty acids was optimized by varying the cycle period of the digestion process with the concentration of Mixed Liquor Suspended Solid (MLSS) maintained at 8000 mg/L for each cycle. The degradation of biomass was carried out using anaerobic sludge digester which 2L of biomass was digested from day 1 until day 24 (cycle period). The tests of MLSS and Mixed Liquor Volatile Suspended Solid (MLVSS) was conducted by Standard Method 2540-D while test for VFAs was conducted through Standard Method 8196. The highest production of volatile fatty acids was obtained in day 5 of cycle period where the concentration is 441 mg/L as acetic acid (HOAC).

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172-176

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June 2014

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[1] D'Addario, E., Pappa, R., Pientrangeli, B., Valdiserri, M. (1992). The acidogenic digestion of the organic fraction of municipal solid waste for the production of liquid fuels.

DOI: 10.2166/wst.1993.0101

Google Scholar

[2] Siddiquee MN, Rohani S. (2011). Lipid extraction and biodiesel production from municipal sewage sludge: A review. Renewable and Sustainable Energy Reviews , 15: 1067-1073.

DOI: 10.1016/j.rser.2010.11.029

Google Scholar

[3] M. Dohanyos, J. Zabranska. (2001). Sludge into biosolids: processing, disposal and utilization. IWA , 13: 223-241.

Google Scholar

[4] W. Rulkens. (2008). Sewage sludge as a biomass resource for the production of energy: overview and assessment of the various options. Energy Fuel , 22: 9-15.

DOI: 10.1021/ef700267m

Google Scholar

[5] T. Liu. (1998). Anaerobic digestion of solid substrates in an innovative Two-Phase Plug-Flow Reactor (TPPFR) and a conventional single-phase continuously stirred tank reactor. Water Sci. Technol., 38 (8–9), 453–461.

DOI: 10.2166/wst.1998.0837

Google Scholar

[6] Ahring, B.K., Ibrahim, A.A., Mladenovska, Z. (2001). Effect of temperature increase from 55 to 65°C on performance and microbial population dynamics of an anaerobic reactor treating cattle manure. Water Resource, Vol. 35, No. 10. 2446-2452.

DOI: 10.1016/s0043-1354(00)00526-1

Google Scholar

[7] S.S. Banister and W. Pretorius (1998). Optimization of primary sludge acidogenic fermentation for biological nutrient removal. Water SA. 24(1), 35-41.

Google Scholar

[8] Zeng R. J., Yuan Z. and Keller J. (2006). Effects of solids concentration, pH and carbon addition on the production rate and composition of volatile fatty acids in prefermenters using primary sewage sludge.

DOI: 10.2166/wst.2006.257

Google Scholar

[9] Q. Yuan, R. Sparling, J.A. Oleszkiewicz (2010). VFA generation from waste activated sludge: Effect of temperature and mixing. Chemosphere 82. 603–607.

DOI: 10.1016/j.chemosphere.2010.10.084

Google Scholar

[10] G. Hui Yu, P. Jing He, L. Ming Shoa, P. Pei He. (2008). Toward understanding the mechanism of improving the production of volatile fatty acids from activated sludge at pH 10. 0. Water Research. 4637-4644.

DOI: 10.1016/j.watres.2008.08.018

Google Scholar