化学沉淀法从氨氮废水中回收磷酸铵镁

Recovery of magnesium ammonium phosphate from ammonia nitrogen wastewater by chemical precipitation

  • 摘要: 在模拟氨氮废水中进行磷酸铵镁(MAP)沉淀实验,研究回收MAP的适宜条件.结果表明:在pH值8.0~11.0之间时生成的沉淀主要成分为MAP;当pH值为10.0,离子配比n(NH4+):n(Mg2+):n(PO43-)控制在1:1.4:1时得到的晶体纯度较高,沉淀量可达3.14g·L-1,此时氨氮去除率为91.5%.分析表明回收MAP可以大幅度降低化学沉淀法的成本,有利于该方法的实际应用.

     

    Abstract: Batch experiments of magnesium ammonium phosphate (MAP) precipitation were conducted to examine the optimal conditions for recovering MAP from simulated NH4+-N wastewater. The experimental results indicated that the precipitates consisted mainly of MAP when the pH was maintained between 8.0 and 11.0. The precipitates, produced at pH 10 and the molar ratio of n (NH4+):n (Mg2+):n (PO43-) was 1:1.4:1, were pure MAP, 3.14 g MAP was attained from 1 L simulated wastewater and the removal rate of NH4+-N could reach 91.5%. It is shown that the application of chemical precipitation method can be promoted for the cost of it could be considerably decreased by recovering MAP.

     

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