核桃壳的改性及其对亚甲基蓝的吸附研究

Study on modification of walnut shell and its adsorption of methylene blue

以亚甲基蓝为研究对象,利用改性前后核桃壳对其吸附效果进行了研究。研究了吸附时间、吸附剂投加量、亚甲基蓝溶液初始浓度及pH对吸附效果的影响,比较了改性前后核桃壳的吸附性能,并拟合了吸附动力学和吸附等温线模型。研究结果表明,核桃壳对亚甲基蓝的吸附率可达95%以上,并且改性后的核桃壳吸附效果优于改性前。核桃壳及酸、碱改性核桃壳吸附亚甲基蓝的过程符合准二级动力学模型,热改性核桃壳吸附亚甲基蓝的过程符合准一级动力学模型。核桃壳及改性核桃壳吸附亚甲基蓝的过程均符合Freundlich吸附等温线模型。本研究期望制得高效廉价的生物吸附剂,并为改性核桃壳用于处理印染废水提供一定的理论依据。

Methylene blue is taken as the research object,the adsorption effect of walnut shell before and after modification was studied.The effects of adsorption time,dosage of adsorbent,initial concentration of methylene blue solution and pH on the adsorption effect were studied,the adsorption properties of walnut shell before and after modification were compared,the adsorption kinetics and adsorption isotherm model were fitted.The results showed that the adsorption rate of methylene blue from walnut shell was more than 95%,and the adsorption effect of modified walnut shell is better than that before modification.The adsorption process of methylene blue by walnut shell and acid-and alkali-modified walnut shell conforms to the quasi-second-order kinetic model,the adsorption process of methylene blue by thermally modified walnut shell conforms to the quasi-first-order kinetic model.The adsorption process of methylene blue by walnut shell and modified walnut shell conforms to Freundlich adsorption isotherm model.This study is expected to prepare an efficient and cheap biological adsorbent and provide a theoretical basis for the treatment of printing and dyeing wastewater by modified walnut shell.