基于响应面法优化MAP法处理垃圾渗滤液工艺的研究

Study on technological parameters of the treatment of landfill leachate by MAP method using response surface methodology

利用单因素实验以及响应面法(response surface methodology,RSM),对磷酸铵镁法(magnesium ammonium phosphate,MAP)去除垃圾渗滤液氨氮的影响因素进行了分析和探讨。考察了pH值为8.0～11.0、n(Mg)∶n(N)摩尔比为0.8～1.6、n(P)∶n(N)摩尔比为0.8～1.3条件下,分析氨氮去除率的变化,用Design-Expert软件处理实验数据,得到了二次响应曲面模型以及优化的水平值。基于经济和操作简便性的考虑,pH值由优化水平的8.3调整为9.5,n(Mg)∶n(N)、n(P)∶n(N)摩尔比取优化水平分别为1.40、1.19,氨氮去除率平均值为92.2%,虽然该条件比最佳条件下的氨氮去除率降低了2个百分点,但从操作的难易程度以及经济性方面,体现了其优势。通过X衍射与电镜扫描分析沉淀物质的成分与晶形,表明大部分沉淀物质为磷酸铵镁。

The effect factors of ammonia-nitrogen removal by magnesium ammonium phosphate（MAP） process for landfill leathate,using single-factor tests and response surface methodology（RSM） were studied.The variance of ammonia-nitrogen removals were analyzed under the conditions of high and low levels of pH values,ratio of n（Mg）∶n（N） and n（Mg）∶n（N）8.0 to 11.0,0.8 to 1.6 and 0.8 to 1.3 respectively.Data were analyzed by the software of Design-Expert 5,a quadratic response surface model and optimum level values in terms of actual factors was obtained based on the experimental data.pH value be adjusted from the optimum level value（8.3） to 9.5,ratio of n（Mg）：n（N） and n（P）：n（N） were 1.40,1.19 respectively from the optimum level values.Ammonia-nitrogen removal efficiency reached to 92.2%.Although the removal rate was 2 percentage lower compared with that under the optimum conditions,the advantage of economy and condition of operation was obvious.The morphology of precipitate was studied by scanning electron microscope（SEM） and X-ray diffraction（XRD）.Most of the composition was magnesium ammonium phosphate.