Anaerobic digestion of dairy manure with enhanced ammonia removal


Uludag-Demirer S., Demirer G. N. , Frear C., Chen S.

JOURNAL OF ENVIRONMENTAL MANAGEMENT, vol.86, no.1, pp.193-200, 2008 (Peer-Reviewed Journal) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 86 Issue: 1
  • Publication Date: 2008
  • Doi Number: 10.1016/j.jenvman.2006.12.002
  • Journal Name: JOURNAL OF ENVIRONMENTAL MANAGEMENT
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.193-200
  • Keywords: struvite, anaerobic digestion, ammonia removal, STRUVITE CRYSTALLIZATION, ORGANIC-MATTER, PRECIPITATION, PHOSPHORUS, TREATABILITY, HYDROLYSIS, RECOVERY

Abstract

Poor ammonia-nitrogen removal in methanogenic anaerobic reactors digesting animal manure has been reported as an important disadvantage of anaerobic digestion (AD) in several studies. Development of anaerobic processes that are capable of producing reduced ammonia-nitrogen levels in their effluent is one of the areas where further research must be pursued if AD technology is to be made more effective and economically advantageous. One approach to removing ammonia from anaerobically digested effluents is the forced precipitation of magnesium ammonium phosphate hexahydrate (MgNH4PO4-6H(2)O), commonly called struvite. Struvite is a valuable plant nutrient source for nitrogen and phosphorus since it releases them slowly and has non-burning features because of its low solubility in water. This study investigated coupling AD and controlled struvite precipitation in the same reactor to minimize the nitrogen removal costs and possibly increase the performance of the AD by reducing the ammonia concentration which has an adverse effect oil anaerobic bacteria. The results indicated that Lip to 19% extra COD and almost 11% extra NH3 removals were achieved relative to a control by adding 1750 mg/L of MgCl2-6H(2)O to the anaerobic reactor. (C) 2007 Elsevier Ltd. All rights reserved.