纳米腐植酸基复合树脂的制备及其对Ni~(2+)和Cd~(2+)的吸附

采用水溶液聚合法,以丙烯酸、丙烯酰胺及改性蒙脱土为原料,纳米腐植酸为基体,N,N’-亚甲基双丙烯酰胺为交联剂,过二硫酸钾为引发剂,制备了丙烯酸-蒙脱土-丙烯酰胺/纳米腐植酸复合树脂(简称复合树脂)。考察了溶液pH、吸附时间、吸附温度、初始离子浓度等因素对复合树脂分别吸附Ni~(2+)和Cd~(2+)的影响。实验结果表明:在吸附温度35℃、吸附时间90 min、溶液pH为7、初始Ni~(2+)和Cd~(2+)的浓度分别为0.02 mol/L、复合树脂加入量16.7 g/L的条件下,Ni~(2+)和Cd~(2+)的吸附量分别为383.02 mg/g和359.27 mg/g;复合树脂吸附Ni~(2+)和Cd~(2+)的吸附等温线均满足Langmuir等温吸附方程;吸附过程均符合准二级动力学方程;复合树脂重复使用6次,其对Ni~(2+)和Cd~(2+)的吸附量分别降低了17.1%和9.3%。

Preparation of Nanoscale Humic Acid Based Composite Resin and Adsorption of Ni2+ and Cd2+

The acrylic acid-montmorillonite-acrylamide/nano humic acid composite resin was prepared by aqueous solution polymerization method,using acrylic acid,acrylamide and modified Montmorillonite as raw material,nano humic acid as matrix,N,N’-methylenebis（2-propenamide） as crosslinking agent and potassium persulfate as initiator. The factors affecting the adsorption of Ni²⁺ and Cd²⁺ were studied. The experimental results showed that：Under conditions of adsorption temperature 35 ℃,adsorption time 90 min,solution pH 7,initial Ni²⁺ concentration 0.02 mol/L,initial Cd²⁺ concentration 0.02 mol/L and composite resin dosage 16.7 g/L,the adsorption quantity of Ni²⁺ and Cd²⁺ are 383.02 mg/g and 359.27 mg/g,respectively;The adsorption isotherm of Ni²⁺ and Cd²⁺ follows Langmuir isothermal equation;Both of the adsorption processes fit pseudo-second order kinetic model;After reused for 6 times,the adsorption capacity of the composite resin to Ni²⁺ and Cd²⁺ decreases 17.1% and 9.3%,respectively.