磷酸铵镁的超声/吹脱协同分解及循环利用研究

Decomposition of Magnesium Ammonium Phosphate by Combination of Ultrasound and Air-stripping and Its Recycling

采用超声/吹脱协同分解磷酸铵镁(MAP),并将其循环利用处理模拟含氨废水,初步探讨了MAP分解反应条件及其循环利用效率。试验结果表明,超声/吹脱能够协同分解MAP,对MAP混合液中氨氮的去除率高达96.24%。在MAP分解过程中,氨氮易从固相转移到液相,而再从液相转移到气相是整个分解过程的关键步骤。MAP经超声/吹脱协同分解后可以循环利用7次以上,但随着循环次数的增加,MAP循环利用效率降低,其中Mg_3(PO_4)_2·8H_2O无法充分参与反应是循环利用效率降低的主要原因。

Magnesium ammonium phosphate （MAP） was decomposed by the combination of ultrasound and air-stripping and reused to treat wastewater containing ammonia nitrogen. Reaction conditions of MAP decomposition and its recycling rate were discussed. The results showed that ultrasound and air- stripping presented synergistic effect, and the removal rate of ammonia nitrogen in MAP mixture achieved 96.24%. The ammonia nitrogen in MAP could easily be transferred from solid phase to liquid phase and it is a critical step for it to transfer to gas phase. MAP was decomposed and recycled at least for 7 times. However, the recycling rate of MAP decreased with the increase of recycling times, which was mainly owing to the incomplete reaction of Mg3 （ PO4 ） 2 · 8H2O.