焙烧镁铝水滑石的制备及其对水中Cl^-和SO_4^(2-)的吸附特性  

Synthesis of calcinations modified Mg-Al hydrotalcite and its adsorption properties for Cl^- and SO_4^(2-) in water

作　　者：李春艳[1] 蒋云福[1] 赵俊[1] 方超[1] 沈跃跃[1] 赵仕林[1,2] 

机构地区：[1]四川师范大学化学与材料科学学院,成都610068 [2]四川省高校农田生态服务能力建设工程中心,成都610068

出　　处：《环境工程学报》2016年第4期1719-1726,共8页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金资助项目(51173122;21406147);四川省2011协同创新中心资助项目(2014005);成都市科技局项目(2014-HM01-00204-SF;2014-HM01-00205-SF)

摘　　要：采用共沉淀法制备了n(Mg)∶n(Al)=3∶1的镁铝水滑石(LDH),进一步通过焙烧得到改性产物LDO,用XRD与FT-IR对LDO进行了表征,系统研究了其对水中Cl^-和SO_4^(2-)的吸附特性。结果表明:焙烧温度为400℃时,LDO对Cl^-和SO_4^(2-)的吸附量较焙烧前分别提高了75.00%和78.20%;p H值在4~10之间,LDO对Cl^-和SO_4^(2-)的吸附量基本无变化;LDO对Cl^-和SO_4^(2-)的吸附分别符合准一级、准二级动力学模型,吸附等温线均可以用Langmuir方程来描述,最大吸附量分别为61.88和227.79 mg/g。LDO对不同浓度的盐渍土洗盐废水的吸附研究结果表明,LDO对洗盐废水中Cl^-和SO_4^(2-)的去除具有较好的效果。LDO投加量相同情况下,Cl^-和SO_4^(2-)浓度分别为60.71和50.03 mg/L时,LDO对Cl^-和SO_4^(2-)的吸附量分别为16.97和22.85 mg/g;当废水中Cl^-和SO_4^(2-)浓度分别为585.75和513.08 mg/L时,LDO对Cl^-和SO_4^(2-)的吸附量分别为0.89和112.47 mg/g。以上研究结果表明,利用LDO处理轻度的氯化物(氯化物硫酸盐)型盐渍土洗盐废水和中度硫酸盐(硫酸盐氯化物)型盐渍土洗盐废水时,吸附效果较好。In the present study,Mg-Al layered double hydroxide（ LDH）（ n（ Mg） ∶ n（ Al） = 3 ∶ 1） was prepared via a co-precipitation method,and then was calcined to obtain the modified product layered double oxide（ LDO）. The structure of the LDO was examined by X-ray diffraction（ XRD） and Fourier transform infrared spectroscopy（ FT-IR）. Afterwards,the adsorption properties of the LDO for Cl^-and SO_4^（2-）in water were researched systematically. The results showed that the adsorption capacities of the modified product（ LDO） increased by 75. 00% and 78. 20% compared to the LDH when the calcination temperature was 400 ℃. When the initial p H value of the solution changed in the range from 4 to 10,the adsorption capacities of the LDO for Cland SO_4^（2-）changed slightly. The results also showed that the adsorption capacities of the LDO for Cl^-and SO_4^（2-）conformed to the pseudo-first-order and pseudo-second-order adsorption kinetic models,respectively,and both of the adsorption processes were fitted well with the Langmuir equation. The maximum adsorption capacities of Cland SO_4^（2-）were 61. 88 and 227. 79 mg / g,respectively. Subsequently,the LDO was further used to adsorb the Cland SO_4^（2-）in saline soil washing wastewater. The LDO exhibited a satisfactory adsorption capacity. When the concentrations of Cl^-and SO_4^（2-）were 60. 71 and 50. 03 mg / L,the adsorption capacities were 16. 97 and 22. 85 mg /g,respectively. When the concentrations of Cl^-and SO_4^（2-）were 585. 75 and 513. 08 mg / L,the sorption capacities were 0. 89 and 112. 47 mg / g. The above results indicated that the LDO can be used to deal with mild chlorides（ chloride sulfate） and moderate sulfates（ sulfate chloride） in saline soil washing wastewater.

关 键 词：镁铝水滑石 焙烧 吸附 Cl^- SO_4^(2-) 

分 类 号：X703[环境科学与工程—环境工程]