超声改善国槐叶纤维对碱性品红的吸附行为

Adsorption Behavior of Ultrasonic Modified Sophora japonica Leaf Fiber for Basic Fuchsin

为改善国槐叶纤维的功能特性,经超声波辅助酸处理的不溶性膳食纤维进行改性处理,用以提高对碱性品红的吸附能力。考察了改性国槐叶对碱性品红的影响因素,进一步二次回归正交旋转优化得碱性品红溶液浓度200 mg/L、吸附时间130 min、加入量1.2 g时有最大吸附率99.06%,实测98.53%。BET及SEM分析可知,改性后表面褶皱加剧且比表面积大,孔道效应易发挥,有助于吸附进行;EDS及FTIR分析得,吸附过程中多是羟基、羧基等起作用且有离子交换;符合Freundlich等温式及准二级动力学模型,说明其吸附过程是以化学吸附为主的多活性位点吸附;改性国槐叶的去除率在1%水平上极显著地优于活性炭、大孔树脂和硅藻纯。

In order to improve the functional characteristics of Sophora japonica fiber, the insoluble dietary fiber treated with ultrasonic assisted acid was modified to improve the adsorption capacity of basic fuchsine. Examines the initial fuchsin solution concentration, adsorption time, modified the salvinia natans slag adding amount,solution pH, adsorption temperature, slag particle size effect on adsorption rate of modified countries salvinia natans fuchsin impact factors, further and quadratic regression orthogonal rotary combination optimization method to predict the best adsorption conditions, and compared with other materials transverse adsorption effect.The structural changes of BET, SEM, EDS and FTIR were characterized and analyzed. Isothermal model and dynamic model were used to analyze the adsorption mechanism. The results showed that the maximum adsorption rate was99.06% when the concentration of basic fuchsin solution was 200 mg/L, the adsorption time was 130 min, and the amount of modified Sophora japonica leaf residue was 1.2 g. BET and SEM analysis showed that after modification,the surface fold was intensified and the specific surface area was large, and the pore effect was easy to play, which was conducive to the adsorption process. According to EDS and FTIR analysis, hydroxyl group and carboxyl group play an important role in the adsorption process, and there is ion exchange. The adsorption kinetics model and the adsorption isotherm model were analyzed and found to be in line with Freundlich isotherm model and quasi-secondary kinetics model, indicating that the adsorption process was dominated by chemical adsorption at multiple active sites. The removal rate of modified Sophora japonica leaves was significantly higher than that of activated carbon, macroporous resin and diatoms at 1%.