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利用分子印迹技术和甲基丙烯酸对壳聚糖进行改性,并在改变吸附条件、吸附动力学和吸附等温线的基础上,对湘江样水中Cr(VI)进行吸附研究。结果表明:X射线衍射谱显示印迹聚合物的结晶能力减弱,但非结晶区面积增加,吸附点位数提高,对Cr(VI)的吸附容量增大;印迹聚合物对Cr(VI)的吸附能力随时间的延长而增加,8 h后达到饱和,最佳吸附时间是吸附后4~8 h,对Cr(VI)的提取率最大值为33.7%。提取液最佳pH值是4.5~7.5;提取率随着壳聚糖脱乙酰度的增大而增大,吸附效果最好的是90%脱乙酰度壳聚糖。吸附量随着壳聚糖的浓度增加而增加,饱和后对Cr(VI)的提取率变化相对平稳,实验测得最高去除率为98.3%。Cr(VI)印迹壳聚糖吸附的准一级动力学和二级动力学模型线性相关系数分别是0.9013和0.9875,吸附速率分别为0.0091 min-1和7.129g/(mg·min)。Cr(VI)印迹壳聚糖的吸附更符合二级动力学模型,与Langmuir吸附等温线的拟合性比Freundlich吸附等温线的更好,计算得到的最大吸附容量为15.784 mg/g,对河水中Cr(VI)的吸附效果明显。
The molecular imprinting technique and methacrylic acid were used to modify chitosan. Based on the change of adsorption conditions, adsorption kinetics and adsorption isotherms, adsorption of Cr (VI) in Xiangjiang sample water was studied. The results showed that X - ray diffraction showed that the crystallinity of the imprinted polymer was weakened, but the area of amorphous region increased, the number of adsorption sites increased and the adsorption capacity of Cr (VI) increased. The adsorption of Cr (VI) The ability to increase with time, saturated after 8 h, the best adsorption time is 4 ~ 8 h after adsorption, the maximum extraction rate of Cr (VI) was 33.7%. The optimum pH value of the extract was 4.5-7.5. The extraction rate increased with the degree of deacetylation of chitosan. The best adsorption was 90% deacetylated chitosan. The amount of adsorption increases with the concentration of chitosan, and the extraction rate of Cr (VI) changes relatively stable after saturation. The maximum removal rate of the sample is 98.3%. The linear correlation coefficients of the quasi-first-order and second-order kinetic models of Cr (VI) imprinted chitosan were 0.9013 and 0.9875, respectively, and the adsorption rates were 0.0091 min-1 and 7.129 g / (mg · min), respectively. The adsorption of Cr (VI) imprinted chitosan is more in accordance with the second-order kinetic model, and its fitting with Langmuir isotherm is better than Freundlich adsorption isotherm. The calculated maximum adsorption capacity is 15.784 mg / g, Cr (VI) in the adsorption effect is obvious.