响应面分析法优化稀土废水MAP沉淀法脱氮  

Optimization of ammonia nitrogen removal from rare-earth wastewater using MAP precipitation by response surface methodology

作　　者：王浩[1,2] 成官文[1,2] 宋晓薇[1] 徐子涵[1,2] 蒙金结[1,2] 董传强[1,2] 

机构地区：[1]桂林理工大学环境科学与工程学院,桂林541006 [2]桂林理工大学广西矿冶与环境科学实验中心,桂林541006

出　　处：《环境工程学报》2013年第12期4748-4754,共7页Chinese Journal of Environmental Engineering

基　　金：广西重点实验室基金项目(桂科能1201Z028)

摘　　要：经过预处理后的稀土生产废水,其氨氮浓度大幅降低,但并未达到中华人民共和国《稀土工业污染物排放标准》(GB26451-2011)中氨氮浓度限值。实验通过响应面分析法中的Box-Behnken实验设计(BBD),取pH、n(Mg)∶n(N)、n(P)∶n(N)3因素,采用Design-Expert 8.0.6,建立合适的剩余氨氮浓度及剩余总磷浓度模型,得到回归方程,并分析模型各项指标,各因素及其相互作用对剩余氨氮浓度及剩余总磷浓度的影响。利用预测模型预测最佳实验条件,在最佳实验条件下验证预测结果,并对沉淀物进行X射线衍射(XRD)分析。结果显示,二次响应模型适用于剩余氨氮浓度及剩余总磷浓度,2个模型均拥有较好的拟合程度、可信度及精密度,最优反应条件为:pH=9.88、n(Mg)∶n(N)=1.50∶1、n(P)∶n(N)=1.38∶1时,剩余氨氮浓度为46.58 mg/L,剩余总磷浓度为7.85 mg/L。在最优条件下所得到的沉淀物并非纯净的MgNH4PO4·6H2O,还有Mg3(PO4)2·22H2O生成。Ammonia nitrogen of rare-earth wastewater was dropped largely after pretreatment,but it was not lower than the Emission Standards of Pollutants from Rare-Earth Industry （GB 26451-2011 ） of China. In this study, Box-Behnken Design（BBD） was applied to experimental design and optimize factors, and factors included pH, n（Mg） ： n （N） and n （P） ： n （N）. Design-Expert 8.0.6, a software of response surface methodology, was used to build qualified response models of residual NH4 -N and residual TP. We got the regression equation, ana- lyzed regression results and interaction of factors for residual NH4＋ -N and TP, and predicted the minimum residual NH4＋-N and TP concentrations. The precipitation generated from the optimum condition was analyzed by X-Ray diffraction. The results showed that quadratic response surface models have goodness of fit,reliability and adequate precision,they are qualified to describe the change of residual NH4＋-N and TP concentrations. The optimum conditions of MAP precipitation are pH =9.88,n（Mg） ： n（N） = 1.50：1 ,n（P） ： n（N） = 1.38： 1,residual NH4＋ -N and TP concentrations are 46.58 mg/L and 7.85 mg/L, respectively. The XRD picture of precipitation shows that besides MgNH4PO4·6H2O,Mg2（PO4）2·22H2O generate in reaction process.

关 键 词：响应面分析 氨氮 MAP 稀土废水 XRD 

分 类 号：X703[环境科学与工程—环境工程]