摘要
采用磷酸氨镁(MAP)沉淀法对新型碳材料生产废水中的氨氮(NH4+-N)进行去除研究,考察了废水初始pH、磷氮摩尔比、镁氮摩尔比对氨氮去除率的影响,利用响应曲面法优化了工艺参数,并通过热力学计算、XRD与SEM等分析了磷酸氨镁(MAP)沉淀脱氮过程及机理。响应曲面拟合结果表明,各因素对氨氮去除率的影响次序为NaOH的用量P。优化工艺参数:在25℃时,当初始氨氮浓度为1 498 mo l/L、P时,氨氮去除率为92.09%。热力学计算结果表明:响应曲面法优化后的Mg^(2+)-PO_(4)^(3)-NH_(4)^(+)-H_(2)O体系为脱氮最佳工艺参数。XRD与SEM等表明沉淀产物主要为MgNH_(4)PO_(4)·H_(2)O固体,呈表面粗糙的不规则棒状结构。
Magnesium ammonium phosphate(MAP)precipitation method was adopted to conduct a study on the removal of ammonium nitrogen(NH4t-N)from wastewater produced in the production of new carbon materials.The effects of initial pH of wastewater,phosphorus-to-nitrogen molar ratio,and magnesium-to-nitrogen molar ratio on the ammonium nitrogen removal rate in wastewater were investigated.Response surface methodology was used to optimize the process parameters,and the denitrification process and mechanism of MAP precipitation were analyzed via thermodynamic calculation,XRD,and SEM.It was shown by the response surface fitting results that the order of influence of each factor on the ammonium nitrogen removal rate was as follows:dosage of NaOH(pH)>n(PO)/n(NH)>n(Mg2*)/n(NH).The optimized process parameters were as follows:at a temperature of 25℃,with an initial ammonium nitrogen concentration of 1498 mol/L,pH-9.9,n(PO_(4)^(3-))/n(NH_(4)^(+))-1.27:1,and n(Mg^(2+))/n(NH_(4)^(+))-1.25:1,the ammonium nitrogen removal rate in wastewater reached 92.09%.The thermodynamic calculation results indicated that the Mg^(2+)-PO_(4)^(3-)-NH_(4)^(+)-H_(2)O system optimized by response surface methodology was the optimal process parameter for denitrification;XRD and SEM indicated that the precipitation product was mainly MgNH4PO4-H2O solid,with a rough surface and irregular rodshaped structure.
作者
朱峥嵘
吴艳
肖继波
颜智勇
王艳姣
万均
湛昭哲
ZHU Zhengrong;WU Yan;XIAO Jibo;YAN Zhiyong;WANG Yanjiao;WAN Jun;ZHAN Zhaozhe(School of Environment and Ecology,Hunan Agricultural University,Changsha 410000,China;College of Life and Environmental Sciences,Wenzhou University,Wenzhou 325035,China)
出处
《环境保护科学》
2025年第5期82-89,共8页
Environmental Protection Science
基金
湖南省自然科学基金(2022JJ6057)。
关键词
磷酸氨镁(MAP)沉淀法
响应曲面
热力学计算
氨氮
脱氮机理
magnesium ammonium phosphate(MAP)precipitation method
response surface
thermodynamic calculation
ammonia nitrogen
denitrification mechanism
