皮胶原纤维固载Zr(IV)对水体中苯羧酸的吸附特性

Adsorption Characteristics of Benzene Carboxylic Acids from Aqueous Solution by Zr(IV)-loaded Collagen Fiber

制备皮胶原纤维固载Zr(IV)吸附剂(ZLCF),并考察ZLCF对水体中苯甲酸(BA)、邻苯二甲酸(o-PA)、对苯二甲酸(p-PA)和间苯二甲酸(m-PA)的吸附特性。研究表明:这4种苯羧酸的吸附平衡同时符合Langmuir和Freundlich方程,但随着它们的羧基数量和位置的不同,其吸附容量也随之变化。总体看,ZLCF对所研究的苯羧酸均具有较大的吸附容量。当苯羧酸溶液(10ml)的初始浓度为6mmol/L、吸附温度为293K时,ZLCF(0.05g)对BA、o-PA、m-PA和p-PA的吸附容量分别达0.4616、0.5892、0.4912和0.3138mmol/g。吸附动力学研究表明:BA的吸附符合拟一级速率方程,边界层扩散为主控步骤;而o-PA、m-PA和p-PA的吸附符合拟二级速率方程,化学吸附为主控步骤。

A novel adsorbent,Zr（IV）-loaded collagen fiber （ZLCF）,was prepared and its adsorption characteristics to benzoic acid （BA）,o-phthalic acid （o-PA）,p-phthalic acid （p-PA） and m-phthalic acid （m PA） from aqueous solution were investigated.It was found that the adsorption equilibrium data of these benzene carboxylic acids can be well fitted by both Langmuir and Freundlich models.But the adsorption capacity of the benzene carboxylic acids changes with the number and position of carboxyl groups on benzene ring.In general,ZLCF has high adsorption capacity to all benzene carboxylic acids investigated.The adsorption capacity of BA,o-PA,m-PA and p-PA was 0.4616,0.5892,0.4912 and 0.3138 mmol/g,respectively,when 10 ml of 6 mmol/L benzene carboxylic acid solution was adsorbed by 0.05 g ZLCF at 293 K.Furthermore,the studies of the adsorption kinetics indicated that the adsorption kinetics of BA was close to the pseudo-first-order rate model and thus the boundary diffusion would be the rate-controlling step.In contrast,the adsorption kinetics of o-PA,m-PA and p-PA can be well described by the pseudo-second-order rate model,which implies that the chemical adsorption should be the rate-controlling step.