Abstract
Studies on the performance of a laboratory scale upflow anaerobic solids removal (UASR) digester were carried out using sand-laden cow manure slurries having total solids (TS) concentration as 50 and 100 g/l. Hydraulic retention time (HRT) was maintained as 32.4 days, which resulted in the volatile solids (VS) loading rates of 1 and 1.64 g/l d. The UASR system was designed to remove sand from the manure slurry, while anaerobically digesting biodegradable solids inside a single reactor. To enhance the contact of microorganisms and substrate, the liquor from the top of the digester was recirculated through the bed of settled solids at its bottom. Volatile solids reduction through this process was observed to be 62% and 68% in the case of feed slurries having TS concentration as 50 and 100 g/l (referred in the text as 5% and 10% feed slurries), respectively. The methane production rates were observed to be 0.22 and 0.38 l/l d, while methane yield was 0.21 and 0.27 l CH4/g VS loaded, for 5% and 10% feed slurries, respectively. This indicates that the increase in the VS loading had a positive impact on methane production rate and methane yield. It would be of interest to study the performance of a UASR digester at higher solids loadings and with longer solids retention times. Nonetheless, the presented study showed that sand-laden manure slurries can be successfully digested in a UASR digester producing methane energy equivalent to 4 kW h per m3 of digester volume per day.
Similar content being viewed by others
References
APHA (1998) Standard methods for the examination of water and wastewater, 20th edn. American Public Health Association, Washington, DC
Bernard JK, Bray DR, West JW (2003) Bacterial concentrations and sand usage in free stalls bedded with fresh and recycled sand. In: Proceedings of 42nd national mastitis council meeting, Fort Worth, TX, 26 January 2003, pp 153–161
Haghighi-Podeh MR, Bhattacharya SK, Mingbo Q (1995) Effects of nitrophenols on acetate utilizing methanogenic systems. Water Res 29(2):391
Holmes BJ (1998) Effective methods for handling sand-laden dairy manure. Presented at the manure management conference, Ames, Iowa, 10–12 February 1998
Karim K, Hoffmann R, Klasson KT, Al-Dahhan MH (2005) Anaerobic digestion of animal waste: waste strength versus impact of mixing. Bioresour Technol 96(16):1771–1781
Linke B (1997) A model for anaerobic digestion of animal waste slurries. Environ Technol 18:849–854
Persson SPE, Bartlett HD, Branding AE, Regan RW (1979) Agricultural anaerobic digesters: design and operation. Bulletin 827. The Pennsylvania State University, Pennsylvania, USA
Sheffield J (2002) Animal residuals 2002 conference and workshop report-number: JIEE 2002-04
Zeeman G, Sanders WTM, Wang KY, Lettinga G (1997) Anaerobic treatment of complex wastewater and waste activated sludge - application of an upflow anaerobic solid removal (UASR) reactor for the removal and pre-hydrolysis of suspended COD. Water Sci Technol 35(10):121–128
Acknowledgement
The authors would like to thank the United States Department of Energy for sponsoring the research project (Identification Number: DE-FC36-01GO11054).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Karim, K., Hoffmann, R. & Al-Dahhan, M.H. Digestion of sand-laden manure slurry in an upflow anaerobic solids removal (UASR) digester. Biodegradation 19, 21–26 (2008). https://doi.org/10.1007/s10532-007-9111-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10532-007-9111-0