Advanced Water Management Centre, The University of Queensland, St. Lucia, QLD 4072, Australia.
Water Res. 2013 May 15;47(8):2890-900. doi: 10.1016/j.watres.2013.03.007. Epub 2013 Mar 19.
Struvite crystallization technology is being widely applied in full-scale due to a surge in nutrient demand and phosphate price increases. Past investigations on struvite crystallization focused on process efficiency and thermodynamics, and less on kinetics, while mainly using fluidized bed type crystallizer. In this work, nucleation and growth kinetic data were measured using stirred vessel. The primary and secondary nucleation was measured in synthetic wastewater, and crystal growth in digested supernatant. The measured kinetic data was correlated with solution supersaturation. The dependence of growth rate on relative supersaturation in the digested was higher compared to synthetic wastewater. The crystal polymorph in synthetic wastewater and real wastewater was comparable. Products from the growth studies showed narrow size distribution and favorable separation characteristics. The secondary nucleation rate showed second order dependence on relative supersaturation. The nucleation induction time decreased with an increase in supersaturation ratio with a clear distinction between homogenous and heterogeneous primary nucleation.
由于营养需求的激增和磷酸盐价格的上涨，鸟粪石结晶技术正在大规模应用。过去的鸟粪石结晶研究主要集中在工艺效率和热力学方面，而对动力学的研究较少，主要使用流化床式结晶器。在这项工作中，使用搅拌釜测量成核和生长动力学数据。在合成废水中测量一级和二级成核，在消化上清液中测量晶体生长。测量的动力学数据与溶液过饱和度相关联。与合成废水相比，消化过程中生长速率对相对过饱和度的依赖性更高。在合成废水和实际废水中的晶体多型性相当。生长研究的产物显示出窄的粒径分布和良好的分离特性。二次成核速率对相对过饱和度呈二级依赖关系。随着过饱和度比的增加，成核诱导时间减少，同质和异质一级成核之间有明显的区别。
