Nucleation and Crystal Growth Rates of Struvite in DTM Type Crystallizer with a Jet-Pump of Descending Suspension Flow in a Mixing Chamber | Science Publications

American Journal of Agricultural and Biological Sciences

Andrzej Matynia¹  Krzysztof Piotrowski¹  Joanna Koralewska¹  Bogusława Wierzbowska¹ 

关键词: struvite;    reaction–crystallization;    SDG MSMPR kinetic model;    phosphate removal;    phosphorus recycling;   

DOI  :  10.3844/ajabssp.2007.260.266

学科分类：农业科学（综合）

来源: Science Publications

【 摘 要 】

The kinetic data concerning reaction crystallization of struvite from diluted water solutions of Mg²⁺, NH₄⁺ and PO₄³ ions in a continuous DTMtype liquid jet-pump crystallizer with internal circulation of suspension are presented and discussed. The measurements were performed with the assumption of minimal value of unit power of a jet-pumps feeding stream, providing thus a minimal level of internal circulation intensity. Nucleation and linear growth rates of struvite crystals were calculated on the basis of population density distributions of product particles. A mathematically convenient kinetic model for MSMPR crystallizer, making allowance for a size dependent growth (SDG) phenomenon, was adopted for description of a complex process of precipitation integrated with crystals growth. It was concluded, that in the concentration range of magnesium ions in a feeding solution [Mg²⁺]_RM = 0.12.0 mass % and, in stoichiometric proportions, phosphate ions [PO₄³]_RM = 0.397.81 mass % as well as the ammonium ions [NH₄⁺]_RM = 0.0741.48 mass %, the Rojkowski hyperbolic SDG kinetic model proved to be an equation the best statistically fitted to the own experimental data.

【 授权许可】

Unknown