Removal and recovery of nutrients as struvite from anaerobic digestion residues of poultry manure


YILMAZEL Y. D. , Demirer G. N.

ENVIRONMENTAL TECHNOLOGY, vol.32, no.7, pp.783-794, 2011 (Peer-Reviewed Journal) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 32 Issue: 7
  • Publication Date: 2011
  • Doi Number: 10.1080/09593330.2010.512925
  • Journal Name: ENVIRONMENTAL TECHNOLOGY
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.783-794
  • Keywords: anaerobic digestion, poultry manure, nutrient recovery, phosphorus dissolution, struvite, WASTE-WATER, PHOSPHORUS RECOVERY, SEWAGE-SLUDGE, PRECIPITATION, PHOSPHATE, CRYSTALLIZATION, CALCIUM, AMMONIA, LIQUID, IMPACT

Abstract

The removal and the recovery of nutrients, namely nitrogen (N) and phosphorus (P) from anaerobically digested and solid-liquid separated manure effluents via struvite precipitation were investigated. Both the liquid and the solid phases of the poultry manure digester effluent were subjected to struvite precipitation experiments. The Mg:N:P molar ratio of 1:1:1 in the liquid phase resulted in an average NH4-N removal efficiency of 86.4%, which increased to 97.4% by adjusting the Mg:N:P ratio to 1.5:1:1. The acidic phosphorus-dissolution process was applied to the solid phase of the effluent to obtain a phosphorus-enriched solution. Nutrient recovery experiments with NaOH as the buffering reagent were conducted with and without addition of external chemicals (Mg and P sources) to evaluate the influence of the Mg:N:P molar ratio, the Mg:P molar ratio and pH. All the experiments depicted complete PO4-P (99.6-100.0%) and partial NH4-N (3.3-65.6%) recoveries from the phosphorus-enriched solution.