Recovery of Phosphate Ions by Continuous Precipitation and Crystallization of Struvite in DTM Type Crystallizer with a Jet Pump
The experimental results concerning reaction crystallization of struvite from diluted water solutions of phosphates (1.0 mass % of PO4 3–) with ammonium and magnesium ions in stoichiometric proportions are presented and discussed. Process was carried out in original construction of a continuous crystallizer with a liquid jet pump of descending suspension flow in a mixing chamber (DTM↓ type crystallizer). The effects of environment’s pH and mean residence time of suspension in a crystallizer working volume on the product crystal quality (Lm, L50, CV) as well as on fundamental kinetic parameters of the process –nucleation and linear growth rates –were determined experimentally. It was observed, that increase in the environment’s pH from 9 to 11 results in about three–fold decrease in a mean size of struvite crystals (from 14.3 to 4.2 μm for τ=900 s). Elongation of mean residence time of suspension from 900 to 3600 s influences crystal size distribution of struvite advantageously (Lm=14.3 → 25.9 μm for pH=9). Linear growth rate and nucleation rate of struvite crystals were estimated on the basis of size–independent growth (SIG) MSMPR kinetic model.
struvite reaction crystallization DTM crystallizer liquid jet pump SIG kinetics
Andrzej MATYNIA Nina HUTNIK Krzysztof PIOTROWSKI Boguslawa WIERZBOWSKA Joanna KORALEWSKA
Wroclaw University of Technology,Faculty of Chemistry,Wybrzeze Wyspianskiego 27,50–370 Wroclaw,Polan Silesian University of Technology,Department of Chemical & Process Engineering,ks. M. Strzody 7,44–1
国际会议
2009 International Symposium on Environmental Science and Technology(2009环境科学与技术国际会议)
上海
英文
986-993
2009-06-02（万方平台首次上网日期，不代表论文的发表时间）