晶种对磷回收效率的影响及其产物分析

以CaO、MgO和白云石石灰（D-Lime）为晶种对模拟厌氧消化上清液进行磷回收试验，研究晶种投加量对磷去除效率的影响，分析试验反应动力学和产物表面形态。结果表明:磷浓度为0.645 mmol/L（ρ（P）=20 mg/L）、n（N）/n（P）为8:1、pH为7.80的模拟水中，投加一定量的CaO、MgO和D-Lime进行磷回收试验，磷的去除率在95%以上，试验反应过程符合准一级反应动力学。针对消化上清液中的高浓度常见离子CO₃2-，当c（CO₃2-）≥ 10 mmol/L时，其对CaO除磷具有明显抑制作用，而对D-Lime和MgO抑制作用有限。此外，投加晶种中含有Mg2+时会生成磷酸铵镁晶体（magnesium ammonium phosphate，MAP）。

STUDY ON PHOSPHORUS RECOVERY EFFICIENCY USING THREE CRYSTAL SEEDS AND THE PRODUCTS

Removal and recovery of phosphate from simulated supernatant of sewage sludge anaerobic digestion effluent were compared using CaO, MgO and dolemite lime(D-Lime)as the crystal seeds respectively, and the kinetics and the surface morphology of the products were analyzed. The results indicated that the removal rate of phosphate were all over 95% using the three crystal, seeds with the condition of initial phosphorus concentration of 0.645 mmol/L, molar ratio of nitrogen to phosphorus of 8:1, and pH value of 7.80. The phosphorus recovery resction was subject to the first order model. However, The high concentration of CO₃2- significantly inhibited the phosphorus removal rate while the CaO was used, but the decline of phosphorus removal rate were limited when the crystal seed was MgO or D-Lime. Moreover, the experimental results also demonstrated that MAP crystals could be obtained in the presence of crystal seed containing Mg2+.