纳米腐植酸基复合树脂的制备及其对Ni^(2+)和Cd^(2+)的吸附

Preparation of Nanoscale Humic Acid Based Composite Resin and Adsorption of Ni^(2+) and Cd^(2+)

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%。

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 Ni^2＋ and Cd^2＋ were studied. The experimental results showed that： Under conditions of adsorption temperature 35 ~C, adsorption time 90 min, solution pH 7, initial Ni^2＋ concentration 0.02 mol/L, initial Cd^2＋ concentration 0.02 mol/L and composite resin dosage 16.7 g/L, the adsorption quantity of Ni^2＋ and Cd^2＋are 383.02 mg/g and 359.27 mg/g, respectively; The adsorption isotherm of Ni2. and Cd^2＋ 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 Ni^2＋ and Cd^2＋ decreases 17.1% and 9.3%, respectively.