硫氰酸根在粒状镁铝复合氧化物上的吸附性能  

Adsorption Properties of Thiocyanate Anion on Granular Mg/Al Mixed Oxides

作　　者：王秀娟[1] 王海增[1] 孙宝维[1] 韩文军[1] 

机构地区：[1]中国海洋大学化学化工学院海洋化学理论与工程技术教育部重点实验室,青岛266100

出　　处：《环境科学》2012年第9期3182-3188,共7页Environmental Science

基　　金：国家科技支撑计划项目(2006BAB03A11-1);教育部博士点专项基金项目(20090132110009)

摘　　要：以镁铝水滑石(Mg/Al-LDH)为前驱物制备了粒状镁铝复合氧化物(G-Mg3.3AlO4.8),采用BET、XRD、SEM和FT-IR方法对其结构进行了表征,考察了这种新材料对硫氰酸根(SCN-)的吸附性能.G-Mg3.3AlO4.8的比表面积和平均孔径分别为269.4 m2.g-1和13.25 nm,成型造粒保留了层状结构且无新相生成.Freundlich等温式和准二级动力学方程能很好地描述SCN-在G-Mg3.3AlO4.8上的静态吸附过程,25℃初始浓度为500 mg.L-1时静态吸附量可达165.8 mg.g-1;Yoon-Nelson模型能很好地预测SCN-在G-Mg3.3AlO4.8上的穿透曲线,初始浓度100 mg.L-1、流速5 mL.min-1、床层高度10 cm和pH=6时穿透点吸附量可达50.73 mg.g-1,重复使用4次对SCN-的脱除率均保持在98%以上,是一种可重复利用的高效吸附剂.Granular Mg/Al mixed oxides（G-Mg3.3AlO4.8） was successfully synthesized by using Mg/Al layered double hydroxide（Mg/Al-LDH） as the precursor.Its structure was characterized by analytical methods of BET,XRD,SEM and FT-IR.Adsorption properties of thiocyanate anion（SCN-） on this new material were also investigated.Specific surface area and average pore width of G-Mg3.3AlO4.8 are 269.4 m2·g^-1 and 13.25 nm respectively.Molding and granulation retains the layer structure and generates no new phase.Freundlich isotherm equation and pseudo-second-order kinetic equation can describe the static adsorption process precisely and adsorption capacity reaches 165.8 mg·g^-1 at 25℃ and 500 mg·L^-1.Yoon-Nelson model can predict the breakthrough curves of SCN-on G-Mg3.3AlO4.8 precisely.The breakthrough adsorption capacity reaches 50.73 mg·g^-1 under the conditions with initial concentration is 100 mg·L^-1,flow rate is 5 mL·min^-1,bed layer altitude is 10 cm and initial pH is 6.The removal rates of SCN-are all above 98% after reusing four times.Consequently,G-Mg3.3AlO4.8is a reusable and high-efficient adsorbent.

关 键 词：镁铝复合氧化物 粒状 硫氰酸根 吸附 穿透曲线 

分 类 号：X703.1[环境科学与工程—环境工程]