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J Hazard Mater. 2013 Jan 15;244-245:357-69. doi: 10.1016/j.jhazmat.2012.11.054. Epub 2012 Dec 1.
A sustainable way to recover phosphorus (P) in swine wastewater involves a preliminary step of P dissolution followed by the separation of particulate organic matter. The next two steps are firstly the precipitation of struvite crystals done by adding a crystallization reagent (magnesia) and secondly the filtration of the crystals. A design of experiments with five process parameters was set up to optimize the size of the struvite crystals in a synthetic swine wastewater. More than 90% of P was recovered as large crystals of struvite in optimal conditions which were: low Mg:Ca ratio (2.25:1), the leading parameter, high N:P ratio (3:1), moderate stirring rate (between 45 and 90 rpm) and low temperature (below 20 °C).These results were obtained despite the presence of a large amount of calcium and using a cheap reactant (MgO). The composition of the precipitates was identified by Raman analysis and solid dissolution. Results showed that amorphous calcium phosphate (ACP) co-precipitated with struvite and that carbonates were incorporated with solid fractions.
一种可持续的从猪废水中回收磷（P）的方法包括先进行 P 溶解，然后分离颗粒状有机物。接下来的两个步骤是首先通过添加结晶试剂（氧化镁）来沉淀鸟粪石晶体，其次是过滤晶体。设计了一个具有五个工艺参数的实验，以优化合成猪废水中鸟粪石晶体的大小。在最佳条件下，超过 90%的 P 以鸟粪石的大晶体形式回收，最佳条件为：低 Mg:Ca 比（2.25:1），这是主导参数，高 N:P 比（3:1），适度的搅拌速度（45 至 90 rpm 之间）和低温（低于 20°C）。尽管存在大量的钙并且使用了廉价的反应物（MgO），但仍获得了这些结果。通过 Raman 分析和固溶实验确定了沉淀物的组成。结果表明，无定形磷酸钙（ACP）与鸟粪石共沉淀，并且碳酸盐与固体部分结合。
