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Struvite precipitation from urine - Influencing factors on particle size.
- Source :
-
Water research [Water Res] 2010 Mar; Vol. 44 (6), pp. 2038-46. Date of Electronic Publication: 2010 Jan 04. - Publication Year :
- 2010
-
Abstract
- Struvite crystallisation is a fast and reliable phosphorus removal and recovery process for concentrated waste streams - such as hydrolysed human urine. In order to optimise P-elimination efficiency, it is beneficial to obtain larger particle sizes: they are easier to separate and less prone to wash-out than smaller particles. This paper presents the results of a study on the effect of process parameters on particle size in a single step struvite precipitation. Crystals formed in batch experiments with real hydrolysed urine were shown to have an average size of >90 microm at pH 9 and 20 degrees C. This is reduced to 45 microm when changing stirrer type. Particle size increases with lower supersaturation. The results showed that under otherwise constant conditions, particle size decreases with lower temperature and has a minimum between pH 9 and 10. Deviating trends are observed at pH <8. Struvite formation in a CSTR (continuously stirred tank reactor) process was shown to be a reliable stable process that does not require any pH control. A method based on conductivity measurement is presented to estimate ionic strength, which is needed for equilibrium calculations.<br /> (Copyright 2009 Elsevier Ltd. All rights reserved.)
- Subjects :
- Calibration
Crystallization
Electric Conductivity
Filtration
Humans
Hydrogen-Ion Concentration
Microscopy, Electron, Scanning
Osmolar Concentration
Reproducibility of Results
Solubility
Struvite
Temperature
Time Factors
Waste Disposal, Fluid
Chemical Precipitation
Magnesium Compounds chemistry
Magnesium Compounds urine
Particle Size
Phosphates chemistry
Phosphates urine
Subjects
Details
- Language :
- English
- ISSN :
- 1879-2448
- Volume :
- 44
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- Water research
- Publication Type :
- Academic Journal
- Accession number :
- 20116825
- Full Text :
- https://doi.org/10.1016/j.watres.2009.12.015