Relationship between magnesium ammonium phosphate (MAP) crystal properties and the filtration ability of hollow fiber membrane (HFM) were investigated. Phosphorus recovery process by crystallization has a problem that it produces a large amount of fine crystals. So improvement of the crystallization process by combining with filtration was discussed. MAP crystals were obtained by batch reaction crystallization and the filtration characteristics were investigated. The filtration was evaluated by the specific filtration resistance (αc) on HFM. Filtered slurry was prepared with each suspension density and crystal size distribution. The solution was filtered at constant pressure of 0.02 MPa and the filtration time on each filtrated volume was recorded. As a result, αc decreases exponentially with suspension density increasing from 0.25 g/L to 0.5 g/L and αc decreases moderately with suspension density increasing from 0.5 g/L to 1.5 g/L. αc of large crystals decreases exponentially at less suspension density than αc of small crystals does. Also, αc increases as the ratio of the fractured crystals increases.
. Filtration ability of hollow fiber membrane for production of magnesium ammonium phosphate crystals by reaction crystallization[J]. Frontiers of Chemical Science and Engineering, 2013, 7(1): 55-59.
H. Watamura, H. Marukawa, I. Hirasawa. Filtration ability of hollow fiber membrane for production of magnesium ammonium phosphate crystals by reaction crystallization. Front Chem Sci Eng, 2013, 7(1): 55-59.
Seyhan D, Weikard H P, van Ierland E. An economic model of long-term phosphorus extraction and recycling. Resources, Conservation and Recycling , 2012, 61: 103–108 doi: 10.1016/j.resconrec.2011.12.005
2
Ott C, Rechberger H. The European phosphorus balance. Resources, Conservation and Recycling , 2012, 60: 159–172 doi: 10.1016/j.resconrec.2011.12.007
3
Jarvie H P, Neal C, Withers P J A. Sewage-effluent phosphorus: a greater risk to river eutrophication than agricultural phosphorus? Science of the Total Environment , 2006, 360(1-3): 246–253 doi: 10.1016/j.scitotenv.2005.08.038
4
Bechmann M E, Berge D, Eggestad H O, Vandsemb S M. Phosphorus transfer from agricultural areas and its impact on the eutrophication of lakes-two long-term integrated studies from Norway. Journal of Hydrology (Amsterdam) , 2005, 304(1-4): 238–250 doi: 10.1016/j.jhydrol.2004.07.032
5
Jaffer Y, Clark T A, Pearce P, Parsons S A. Potential phosphorus by struvite formation. Recovery Water Research , 2002, 36: 1834–1842
6
Bradford-Hartke Z, Lant P, Leslie G. Phosphorus recovery from centralised municipal water recycling plants. Chemical Engineering Research & Design , 2012, 90(1): 78–85 doi: 10.1016/j.cherd.2011.08.006
7
Hirasawa, Kaneko S, Kanai Y, Hosoya S, Okuyama K. Crystallization phenomena of magnesium ammonium phosphate (MAP) in a fluidized-bed-type crystallizer. Journal of Crystal Growth , 2002, 237–239 : 2183–2187
8
Shimamura K, Hirasawa I, Ishikawa H, Tanaka T. Phosphorus recovery in a fluidized bed crystallization reactor. Journal of Chemical Engineering of Japan , 2006, 39(10): 1119–1127 doi: 10.1252/jcej.39.1119
9
Hirasawa, Nakagawa H, Yoshikawa O, Itoh M. Phosphate recovery by reactive crystallization of magnesium ammonium phosphate: application to wastewater. American Chemical Society , 1997, 667: 267–276
10
Hirasawa, Toya Y. Fluidized-bed process for phosphate removal by calcium phosphate, crystallization as a separations process. American Chemical Society , 1990, 438: 355–363
11
Shimamura K, Ishikawa H, Tanaka T, Hirasawa I. Use of a seeder reactor to manage crystal growth in the fluidized bed reactor for phosphorus recovery. Water Environment Research , 2007, 79(4): 406–413 doi: 10.2175/106143006X111899
12
Ruth B F, Montillon G H, Montonna R E. Studies in filtration. 1. Critical analysis of filtraion theory. Industrial & Engineering Chemistry , 1933, 25(1): 76–82 doi: 10.1021/ie50277a018
13
Ruth B F, Montillon G H, Montonna R E. Studies in filtration. 2. Fundamental axiom of constant-pressure filtraion. Industrial & Engineering Chemistry , 1933, 25(2): 153–161 doi: 10.1021/ie50278a010
