改性葡萄藤对水中次甲基蓝吸附特性的影响

以农林废弃物葡萄藤为原料，选用NaOH为改性剂，在最适的改性条件下制备葡萄藤吸附剂，研究了改性后的葡萄藤对次甲基蓝的吸附性能。结果表明，室温下用0.5 g改性葡萄藤，处理浓度为100 mg/L，pH值为6.8的次甲基蓝溶液50 mL，振荡吸附60 min，吸附率可达97.7％；改性葡萄藤对次甲基蓝的吸附符合Freundlich方程所描述的规律，吸附过程的△G<0，△H为16.43 kJ/mol，△S为60.86 J/mol·K，吸附过程符合拟二级动力学模型，E_a为27.85 kJ/mol，吸附是自发的、吸热的熵驱动过程。

Adsorption Capability of Modified Grape Stalks to Methylene Blue

Grape stalks were modified by using sodium hydroxide.Under the optimal modification conditions,modified grape stalks adsorbent were prepared,and the adsorption properties of modified grape stalks to methylene blue from aqueous solutions were analyzed.The results showed that the adsorption rate of the modified grape stalk to methylene blue could reach 97.7％ under the following conditions:methylene blue concentration,100 mg/L; adsorbent dosage,0.5 g; pH,6.8; temperature,25℃ ,oscillatioin time,60 min.Absorptive isotherm to methylene blue well fitted with the Freundlich adsorption model.Thermodynamic parameters of Gibbs free energy (△G) was negative,enthalpy of adsorption (△H) value was 16.43 kJ/mol and the entropy (△S) value was 60.86 J/mol·K,the adsorption kinetics was well described by the proposed kinetic model II,the activation energy (E_a) was determined to be 27.85 kJ/mol,so the adsorption to methylene blue by modified grape stalks was a spontaneous,exothermic driven process.