采用部分偕胺肟化的聚丙烯腈纤维与铁离子反应,形成偕胺肟合铁(Ⅲ)纤维,以此为吸附材料,吸附水溶液中的还原棕染料. 研究了其吸附反应条件、吸附规律及吸附反应动力学. 结果表明,pH值11.5～12.5、温度60 ℃和吸附时间60 min为最佳吸附反应条件. 偕胺肟合铁(Ⅲ)纤维对还原棕的吸附反应符合Langmuir方程和Freundlich等温吸附经验式. 采用不同初始浓度研究吸附时间与溶液浓度的关系,用微分法确定了反应级数和反应速率常数. 由不同温度下的速率常数,并结合Arrhenius方程求出了反应的活化能. 结果表明,偕胺肟合铁(Ⅲ)纤维对还原棕的吸附符合一级反应动力学特征,速率方程c=c_0e~(-kt),速率常数k=32.01e~(-E_a/RT),活化能E_a=11.55 kJ/mol.%Amidoxime chelating fiber containing Fe ( Ⅲ) was prepared from the reaction of partially amido-ximated PAN fiber with Fe~(3+). The studies of its adsorptive behavior for vat brown dye were performed in aqueous media. Results from the investigation on its adsorptive conditions, adsorption rules and adsorption kinetics show that the optimal adsorption parameters are pH: 11. 5 ～ 12. 5, t= 60 ℃( temperature ) and time = 60 min (time). Its adsorptive behavior for vat brown dye fits well with Langmuir and Freundlich isotherm equation. Furthermore, the relationship between adsorption time and sample concentration was investigated by employing various initial concentrations, from which the corresponding reaction order and rate constant were determined by differential method. Based on the Arrhenius equation, the activation energy(E_a) was calculated to be 11. 55 kJ/mol from rate constants at different temperatures. The overall analysis demonstrates that the adsorptive behavior of the present amidoxime chelating fiber containing Fe ( Ⅲ) for vat brown BR dye characterizes first-order reaction with c = c_0e ~(-kt) and k = 32. 01e~(-E_a/RT) .
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