壳聚糖的改性及其去除废水中染料物质的性能研究

Modification of a chitosan and its performances in dye substance removal from wastewater

采用戊二醛交联FeCl_3制备改性壳聚糖吸附处理染料废水,以20 mg·L^(-1)的亚甲基蓝溶液作为处理对象,探究氯化铁改性壳聚糖(FeCl_3-CTS)投加量、废水p H值、反应时间对其处理亚甲基蓝废水性能的影响,并对吸附动力学、吸附等温线过程进行拟合.结果表明,FeCl_3-CTS对亚甲基蓝废水的处理效果远高于未改性壳聚糖(N-CTS),尤其是在投加量为0.1 g·L^(-1)、p H=6的条件下,经FeCl_3-CTS处理50 min后,亚甲基蓝废水的脱色率高达99.4%,FeCl_3-CTS对亚甲基蓝的吸附容量高达198.8 mg·g^(-1),与N-CTS的54.8%和109.6 mg·g^(-1)相比,均有显著的提高.吸附动力学、吸附等温线拟合结果显示,FeCl_3-CTS对亚甲基蓝废水的吸附过程符合准二级反应动力学方程(R2=0.9992)和Langmuir等温线方程(R^2=0.9995).

A modified chitosan was prepared by cross linking with glutaraldehyde and FeCl3 for dye substance removal from wastewater. Methylene blue solution was selected as the treatment object,and effects of modified chitosan dose,solution p H value,and contact time on methylene blue removal with initial concentration of 20 mg·L^-1 were investigated. Furthermore,the kinetics equations and isotherm equations were used to fit the adsorption process of the modified chitosan in methylene blue treatment. Results showed that the removal efficiency of methylene blue by the FeCl3-modified chitosan was better than that by the natural chitosan. Especially,when the FeCl3-modified chitosan dose was adjusted to 0.1 g·L^-1 and the solution p H value was adjusted to6,after 50 min,methylene blue removal efficiency reached a maximum value of 99. 4%,and the corresponding adsorption capacity reached 198. 8 mg·g^-1,compare to that of 54.8% and 109.6 mg·g^-1 by the natural chitosan,both removal efficiency and adsorption capacity were improved significantly.Furthermore,the methylene blue adsorption process could be well fitted to the pseudo-second-order kinetic model（ R^2= 0. 9992） and the Langmuir equilibrium model（ R^2= 0.9995）.