Prediction of Struvite Formation to Recover Phosphorus from Human Urine Using an Equilibrium Model
Prediction of Struvite Formation to Recover Phosphorus from Human Urine Using an Equilibrium Model
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使用平衡模型预测鸟粪石形成以从人尿中回收磷
DOI：
10.2965/jswe.28.191
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
T. Nagasaka
中科院分区：
文献类型：
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作者：
H. Harada;Y. Shimizu;Y. Miyagoshi;S. Matsui;T. Matsuda;T. Nagasaka
从废水中回收磷已引起越来越多的关注。由于人尿是环境中磷的主要来源之一，因此已经进行了几项研究以从粪便中提取的人尿中回收磷。通过在碱性条件下添加镁盐，可以将人尿中的磷以 MAP 沉淀（即鸟粪石，MgNH4PO4·6H2O）的形式回收。然而，人们对人尿液中 MAP 形成的化学反应知之甚少，而这对于该反应的实际应用至关重要。在这项研究中，我们建立了一个平衡模型来理解这种化学现象并预测人类尿液中 MAP 的形成。此外，通过合成和转移的人尿实验形成 MAP 沉淀物，以验证模型。因此，MAP 形成模型具有相当大的有效性。使用该模型，我们预测了在不同 pH 值和镁盐添加量下转移的人尿液中 MAP 的形成。我们得出的结论是，为了在尿液分流厕所中尿液中形成 MAP，并在上清液中实现 0.1 mg·l-1 的 PO4-P 浓度，需要添加至少 10 mM MgCl2。在这种情况下，最佳 pH 值是 9.7。
Phosphorus recovery from wastewater has been a growing concern. Since human urine is one of the main sources of phosphorus in the environment, several studies have been undertaken to recover phosphorus from human urine diverted from feces. Phosphorus in human urine can be recovered as a precipitate of MAP (i.e., struvite, MgNH4PO4·6H2O) by adding magnesium salt under alkaline conditions. However, little is known about the chemical reaction of MAP formation in human urine, which is essential for the practical application of the reaction. In this study, we established an equilibrium model to understand such a chemical phenomenon and to predict MAP formation in human urine. In addition, MAP precipitates were formed experimentally from synthesized and diverted human urine for the validation of the model. As a result, there was a considerable validity of the model of MAP formation. Using this model, we predicted MAP formation in diverted human urine at different pHs and amounts of magnesium salt added. We concluded that the addition of at least 10 mM MgCl2 is necessary in MAP formation in urine in a urine-diversion toilet and in achieving a PO4-P concentration of 0.1 mg·l-1 in the supernatant. In such a case, the optimal pH is 9.7.