Enhanced Nutrients Removal in Conventional Anaerobic Digestion Processes
One of the main challenges for one phase anaerobic digestion processes is the high concentration of NH4+ and PO4 3- ions in the digested sludge supernatant. This project focuses on enhancing the removal of nutrients during the anaerobic digestion process through fixing both NH4+ and PO4 3- ions in the form of struvite (magnesium ammonium phosphate, MAP, MgNH4PO4.6H2O) within the anaerobic sludge. Batch anaerobic digestion tests showed that Mg2+ concentration in the range 279 – 812 mg/L had insignificant effect on CGP but incurred a slight increase in COD removal. The reactor that had soluble Mg2+:NH4+:PO43- at a molar ratio of 1.28:1:00:1:00 achieved the best performance enhancement of 8% increase in COD removal and 32% reduction in NH4+ in the reactor supernatant. Overall, the results show that there is a potential to optimise conventional anaerobic digestion such that supernatant lean in P and N, and sludge rich in nutrients are obtained.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1063397Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1416
 J. Cheng and B. Liu, "Swine wastewater treatment in anaerobic digesters with floating medium," Trans ASAE, vol. 45, pp. 799-805, 2002.
 T. Noike, I. S. Goo, H. Matsumoto and T. Miyahara, "Development of a new type of anaerobic digestion process equipped with the function of nitrogen removal," Wat. Sci. Technol., vol. 49, pp. 173-179, 2004.
 G. N. Demirer and S. Chen, "Two-phase anaerobic digestion of unscreened dairy manure," Process Biochem., vol. 40, pp. 3542-3549, 2005.
 P. Lusk, "Methane recovery from animal manures the current opportunities casebook," National Renewable Energy Laboratory, NREL/SR-580-25145, September 1998.
 Y. Jaffer, T. A. Clark, P. Pearce, and S. A. Parsons, "Potential phosphorus removal by struvite formation," Water Res, vol. 36, pp. 1834-1842, 2003.
 X. Z. Li, Q. L. Zhao, and X. D. Hao, "Ammonium removal from landfill leachate by chemical precipitation," Waste Man, 19, pp. 409-415, 1999.
 R. T. Burns, L. B. Moody, F. R. Walker, and D. R. Raman, "Laboratory and in-situ reductions of soluble phosphorus in swine waste slurries," Environ. Technol. Vol. 22, pp. 1273-1278, 2001.
 Nelson, N.O., Mikkelsen, R.E. and Hesterberg, D.L. (2003) Struvite precipitation in anaerobic swine lagoon liquid: effect of pH and Mg:P ratio and determination of rate constant. Biores. Technol., 89, 229-236.
 S. Uludag-Demirer, G. N. Demirer, S. Chen, "Ammonia removal from anaerobically digested dairy manure by struvite precipitation," Process Biochemistry, vol. 40, pp. 3667-3674, 2005.
 J. J. Lee, C. U. Choi, M. J. Lee, I. H. Chung, and D. S. Kim, "A study of NH3-N and P refixation by struvite formation in hybrid anaerobic reactor," Wat. Sci. Technol. Vol. 49, pp. 207-214, 2004..
 S. Uludag-Demirer, G.N. Demirer,C. Frear, and S. Chen, "Anaerobic digestion of dairy manure with enhanced ammonia removal," J of Env. Man., 86, 193-2008.
 J. Wang, J. G. Burken, X. Zhang and R. Surampalli, "Engineered struvite precipitation: Impacts of component-ion molar ratios and pH," J Env. Eng. ASCE, vol 131, n 10, pp. 1433-1440, October 2005.
 M. I. H. Bhuiyan, D. S. Mavinic and F. A. Koch, "Thermal decomposition of struvite and its phase transition," Chemosphere, vol. 70, pp. 1347 - 1356, 2008.
 I. J. Kugelman and K. K. Chin, "Toxicity, sygernism and the antagonism in anaerobic waste treatment processes, anaerobic Biological Treatment Processes, F.G. Phland, editor, American Chemistry Society, Advances in Chemistry Series, 105, 55-90, 1971.
 F. Gumersindo, S. Manuel, M. Ramon and L. M. Juan, "Sodium inhibition in the anaerobic digestion process: Antagonism and adaptation phenomena," Enzyme and Microbial Technology, vol. 17, no. 2, pp. 180-188, Feb 1995.
 H. Siegrist, D. Gajcy, S. Sulzer, P. Roeleveld, R. Oschwald, H. Frischknecht, D. Pfund, B. Morgeli, and E. Hugerbuhler, ÔÇ×Nitrogen elimination from digester supernatant with magnesium- immonium phosphate," proceedings of the Fifth Gothenburg Symposium, September 28-30. Berlin: Springer, 1992.