Recovery of nitrogen and phosphorous as struvite from swine waste biogas digester effluent.
- Author:
P W Anton PERERA
1
;
Zhi-Ying HAN
;
Ying-Xu CHEN
;
Wei-Xiang WU
Author Information
- Publication Type:Journal Article
- MeSH: Animals; Bioelectric Energy Sources; Bioreactors; Chemical Precipitation; Hydrogen-Ion Concentration; Magnesium Compounds; chemistry; isolation & purification; Manure; Nitrogen; chemistry; isolation & purification; Phosphates; chemistry; isolation & purification; Phosphorus; chemistry; isolation & purification; Struvite; Swine; Waste Disposal, Fluid; X-Ray Diffraction
- From: Biomedical and Environmental Sciences 2007;20(5):343-350
- CountryChina
- Language:English
-
Abstract:
OBJECTIVETo investigate the feasibility of nitrogen and phosphorus recovery from swine waste biogas digester effluent and the effects of pH and NH4+: Mg2+: PO4(3-) molar ratio on its precipitation.
METHODSPrecipitation experiments with swine waste biogas digester effluent were conducted at pH 7.5, 8.0, 8.5, and 9.0 together with NH4+: Mg2+: PO4(3-) molar ratios 1: 0.2: 0.08, 1: 1: 1, and 1: 1.5: 1.5. Chemical and X-ray diffraction (XRD) analysis were done to determine the composition of the precipitate.
RESULTSThe highest removal and recovery of NH4+ and PO4(3-) were achieved at pH 9.0 in each experiment. The elevation of pH to 9.0 alone could decrease the initial PO4(3-) concentration from 42 mg L(-1) to 4.7 mg L(-1) and 89.2% PO4(3-) recovery was achieved. The pH-molar ratio combination 9.0-1: 1.5: 1.5 effected 76.5% NH4+ and 68.5% PO4(3-) recovery. The molar ratio of 1: 1: 1 together with pH elevation to 9.0 was determined to be the optimum combination for both NH4+ and PO4(3-) removal as it recovered over 70% and 97% of the initial NH4+ and PO4(3-), respectively.
CONCLUSIONSNitrogen and phosphorus can be recovered from biogas digester effluent as struvite.
