改性壳聚糖的制备及其对水中酞酸酯的吸附

以柠檬醛化学改性壳聚糖,制备柠檬醛交联壳聚糖树脂。采用红外光谱(IR)、X射线衍射(XRD)、扫描电镜(SEM)、比表面测定及孔径分析方法表征柠檬醛交联壳聚糖树脂的结构。在25℃,pH为7条件下,考察柠檬醛交联壳聚糖树脂对3种酞酸酯(PAEs)邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二丁酯(DBP)和邻苯二甲酸2-乙基己酯(DEHP)的吸附性能,剖析吸附机理。研究结果表明,壳聚糖对DMP、DEHP和DBP的吸附容量分别为92、113和87 mg/g,而柠檬醛交联壳聚糖树脂对DMP、DEHP和DBP的吸附容量分别为147、166和190 mg/g,柠檬醛交联壳聚糖树脂对3种PAEs的吸附效果明显提高,吸附动力学均满足一级动力学方程。经吸附剂再生实验,柠檬醛交联壳聚糖树脂对PAEs的脱附率达到96.5%~97.1%,可重复使用。

Preparation of Modified Chitosan and Its Adsorption of Phthalic Esters from Aqueous Solution

Citral crosslinked chitosan resin was prepared by chitosan and citral.Its structure was characterized by infrared spectrum(IR),X-ray diffraction(XRD),scanning electron microscope(SEM),surface area determination and pore size analysis.Its specific surface and bore diameter were also determined.The adsorption capability of the resin for phthalic esters(PAEs)was investigated under pH 7 and 25 ℃.Experimental results showed that the adsorption ability of chitosan for dimethyl phthalate(DMP),di-n-butylphthalate(DBP) and di-(2-ethylhexyl)phthalate(DEHP) were 92,87 and 113 mg/g respectively.The adsorption ability of citral crosslinked chitosan resin for DMP,DEHP and DBP were 147,166 and 190 mg/g respectively.The adsorption effects of the polymer on the PAEs had significantly improved,and its adsorption behavior to DMP,DBP and DEHP followed the first-order kinetic equation.It was found that the polymer which is reusable has a better desorption rate of 96.5%~97.1%.