Experimental Insights into the Genesis and Growth of Struvite Particles on Low-Solubility Dolomite Mineral Surfaces
Experimental Insights into the Genesis and Growth of Struvite Particles on Low-Solubility Dolomite Mineral Surfaces
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DOI：
10.1021/acs.jpcc.9b05292
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发表时间：
2019-09
期刊：
影响因子：
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通讯作者：
Daniyal Kiani;Manoj Silva;Y. Sheng;J. Baltrusaitis
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文献类型：
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作者：
Daniyal Kiani;Manoj Silva;Y. Sheng;J. Baltrusaitis
低溶解度含 Mg2+ 矿物表面，包括方镁石 (MgO) 和菱镁矿 (MgCO3)，可以作为 Mg2+ 离子的可持续来源，通过二维表面促进生长产生绿色肥料鸟粪石 (MgNH4PO4)。这项工作研究了利用模拟废水中的 NH4+ 和 PO43- 离子形成鸟粪石过程中天然矿物白云石 (CaMg(CO3)2) 的动力学、机理和单颗粒形态。对一系列 [Mg2+]/[NH4+]/[PO43–] 比例进行了测试，0.69:1:1 [500/600 ppm 白云石/磷酸一铵 (MAP)] 的 NH4+ 去除效率最高，为 37%。使用比例 1.37:1:1（1000/600 ppm 白云石/MAP）获得最高 94% 的 PO43– 去除率，但产生的是无定形固体磷酸盐相而不是鸟粪石。此外，在空间分辨异位单晶拉曼光谱中观察到显着的成分异质性，检测到CaCO3、MgCO3、MHPO4和M(H2PO4)2（M：Mg或Ca）。临时解析的原位拉曼光谱...
Low-solubility Mg2+-containing mineral surfaces, including periclase (MgO) and magnesite (MgCO3), can act as sustainable sources of Mg2+ ions to yield green fertilizer struvite (MgNH4PO4) via a two-dimensional surface-facilitated growth. This work studied the kinetics, mechanism, and single-particle speciation of the natural mineral dolomite (CaMg(CO3)2) during struvite formation utilizing NH4+ and PO43– ions from simulated wastewater. A range of [Mg2+]/[NH4+]/[PO43–] ratios were tested and 0.69:1:1 [500/600 ppm of dolomite/monoammonium phosphate (MAP)] yielded the highest NH4+ removal efficiency of 37%. The highest PO43– removal of 94% was obtained using ratio 1.37:1:1 (1000/600 ppm dolomite/MAP) but resulted in an amorphous solid phosphate phase rather than struvite. Moreover, significant compositional heterogeneities were observed in the spatially resolved ex situ single-crystal Raman spectroscopy with CaCO3, MgCO3, MHPO4, and M(H2PO4)2 (M: Mg or Ca) detected. Temporally resolved in situ Raman spectros...