MgFe-LDH的制备及其对硝态氮的吸附再生性能研究  

Study on Preparation of MgFe-LDH and Its Adsorption and Regeneration Properties for Nitrate Nitrogen

作　　者：刘果果 冯民权[1] 王毅博[2] 赵直 LIU Guoguo;FENG Minquan;WANG Yibo;ZHAO Zhi(State Key Laboratory of Eco-hydraulics in Northwest Arid Region,Xi’an University of Technology,Xi’an 710048,China;School of Environment and Chemical Engineering,Xi’an Polytechnic University,Xi’an 710048,China)

机构地区：[1]西安理工大学西北旱区生态水利国家重点实验室,陕西西安710048 [2]西安工程大学环境与化学工程学院,陕西西安710048

出　　处：《环境科学与技术》2025年第4期22-29,共8页Environmental Science & Technology

基　　金：国家自然科学基金资助项目(51679191);陕西省重点研发计划资助项目(2024SF-ZDCYL-05-03)。

摘　　要：常见吸附剂对污水厂二级出水中硝态氮的选择性和吸附容量不高,该研究采用水热合成法制备镁铁层状双金属氢氧化物材料(MgFe-LDH),并提出一种深度脱氮技术。结果表明:MgFe-LDH对硝态氮的最大吸附容量可达到7.571 mg/g,最佳制备条件为晶化温度150℃、摩尔比4∶1、晶化时间7 h;对于10 mg/L的低浓度硝态氮废水而言,MgFe-LDH的最佳投加量为150 mg,且对pH变化具有一定的缓冲能力;常见共存阴离子(Cl^(-)、SO_(4)^(2-)和PO_(4)^(3-))与硝态氮之间不存在明显的竞争吸附效应,MgFe-LDH对硝态氮具有较高的吸附选择性,理论最大吸附量可达15.409 mg/g;在最佳脱附条件下,脱附率可达78.34%,三次再生率为67.68%,具备一定的再生能力。研究成果可为污水厂深度处理低浓度硝态氮废水提供参考。The selectivity and adsorption capacity of common adsorbents for nitrate nitrogen in secondary effluent of sewage plants are not high.In this study,an advanced denitrification technique was proposed using layered double hydroxide(MgFe-LDH)prepared by the hydrothermal synthesis method.The results indicated that the maximum adsorption capacity of MgFe-LDH for nitrate nitrogen can reach 7.571 mg/g,and the optimum preparation conditions are crystallization temperature 150℃,molar ratio 4∶1,crystallization time 7 h.The optimal dosage of MgFe-LDH is 150 mg for low-concentration nitratenitrogen wastewater of 10 mg/L,and it has a certain pH buffering capability.There is no significant competitive adsorption effect observed between common co-existing anions(Cl^(-),SO_(4)^(2-),and PO_(4)^(3-))and nitrate nitrogen.MgFe-LDH has a high adsorption selectivity for nitrate nitrogen,and the theoretical maximum adsorption capacity can reach 15.409 mg/g.Under the best desorption conditions,the desorption rate was 78.34%,and the three-cycle regeneration efficiency was 67.68%.These research findings can provide reference for further treatment of low-concentration nitrate nitrogen wastewater in wastewater treatment plants.

关 键 词：MgFe-LDH 制备 硝态氮 吸附 再生 

分 类 号：X703.1[环境科学与工程—环境工程]