磷酸铵镁结晶法高效回收提钒废水中的高浓度氨氮

为实现提钒废水中氨氮的高效回收，探究了磷酸铵镁(MAP)结晶法回收提钒废水中高浓度氨氮过程中磷源、镁源、pH值、沉淀时间和n(Mg)∶n(N)∶n(P)对氨氮回收率的影响，采用Box-Behnken响应面法进行优化建模并用XRD分析产物.结果表明:MgCl₂·6H₂O和Na₂HPO₄·12H₂O是最适合的镁源和磷源.最佳沉淀时间为20min.响应面得到的多项式回归方程表明各因素对氨回收率的影响程度为n(Mg)∶n(N)＞n(P)∶n(N)＞pH，在最优条件附近，pH值、n(Mg)∶n(N)和n(P)∶n(N)分别为9.51，1.22和1.12时进行实验验证，氨的回收率为98.32%，模型优化效果明显.综上，通过响应面优化MAP法对提钒废水中氨氮的高效回收有重要意义.

Efficient Recovery of Highly Concentrated Ammonia Nitrogen from Vanadium-extraction Wastewater with MAP Method

In order to realize the efficient recovery of ammonia nitrogen from vanadium-extraction wastewater， influencing factors including phosphorus source， magnesium source， pH value， reaction time and the molar ratio of n(Mg)∶n(N)∶n(P) were investigated. The Box-Behnken response surface method was then used to optimize the modeling and XRD was used to analyze the products. The results indicated that MgCl₂·6H₂O and Na₂HPO₄·12H₂O were used as the most suitable source of magnesium and phosphorus， and the best precipitation time was 20min. The polynomial regression equation obtained with the Box-Behnken response surface method showed that the influence degree of each factor on the ammonia recovery percent was n(Mg)∶n(N)＞n(P)∶n(N)＞pH. The confirmatory experiment was carried out around the optimal conditions， and pH， n(Mg)∶n(N) and n(P)∶n(N) were 9.51， 1.22 and 1.12， respectively. The recovery percent of ammonia nitrogen was 98.32%， and the effect of model optimization was obvious. In summary， the optimization of MAP with the response surface method for the high-efficiency recovery of ammonia nitrogen in vanadium extraction wastewater is of great significance， especially for the efficient resource utilization of high ammonia-nitrogen wastewater in the expanded vanadium-extraction industry.