蔺草负载活性炭对Cr（Ⅵ）的吸附过程分析

摘要

Efficient Cr(Ⅵ) adsorbent based on mat rush (Juncus effusus L.) was prepared in case of not being smashed, along with activated carbon (AC) particles being deposited on the rush surface. The adsorption behaviour was studied and adsorption curves were fitted by kinetics equations and isotherm models.The results showed that the dynamic adsorption met the pseudo-second order kinetics, which indicated that the adsorption rate was controlled by chemical adsorption. The adsorption isotherm was found to follow the Langmuir model rather than Freundlich model. The deposition of AC particles greatly enhanced the adsorption ability of the rush, in condition that the pH value was 1.0, the adsorbent dosage was 1.0 g/50mL, and the oscillation time was 20 hours, an adsorption rate of 99.6%was obtained in the 100 mg/L Cr(Ⅵ) solution at 25℃.%以表面具有沟槽结构的蔺草为基体，通过在其表面负载活性炭颗粒，在不做粉碎处理的情况下得到高效生物基Cr（Ⅵ）吸附剂。分别以准一级、准二级动力学方程和Langmuir模型、Freundlich模型对其吸附特征曲线进行了拟合分析。结果表明：该吸附剂对Cr（Ⅵ）的吸附过程遵循准二级反应机理，吸附速率被化学吸附所控制。吸附等温线符合Langmuir模型。通过表面负载活性炭粒子，大幅度提高了蔺草对Cr（Ⅵ）的吸附性能，当pH值为1.0，蔺草用量为50 mLCr（VI）溶液1.0 g，对浓度100 mg/L的Cr（Ⅵ）溶液25℃下吸附20 h，Cr（Ⅵ）吸附率达到99.6%。