谷氨酸接枝交联磁性壳聚糖对废水中铬(Ⅵ)的吸附性能  

Adsorption performance of chromium(Ⅵ)in wastewater on cross-linked magnetic chitosan modified by grafting with glutamic acid

作　　者：张雯雯[1] 雷昌贵[1] ZHANG Wenwen;LEI Changgui(Henan Vocational College of Quality Engineering,Pingdingshan 467000,China)

机构地区：[1]河南质量工程职业学院,河南平顶山467000

出　　处：《冶金分析》2023年第6期77-84,共8页Metallurgical Analysis

基　　金：河南省教育科学规划一般课题项目(2022YB0575)。

摘　　要：为增强壳聚糖吸附Cr(Ⅵ)的能力,以戊二醛作交联剂,谷氨酸、壳聚糖和Fe_(3)O_(4)为原料,制备谷氨酸接枝交联磁性壳聚糖(Glu-CS/Fe_(3)O_(4))。通过傅里叶变换红外光谱(FTIR)、扫描电子显微镜及热重分析对产物进行表征,结果表明Glu-CS/Fe_(3)O_(4)制备成功。将0.075 g Glu-CS/Fe_(3)O_(4)加入到50 mL 100 mg/L Cr(Ⅵ)溶液(pH 3.0)中于40℃静态吸附120 min后,其对Cr(Ⅵ)的吸附率接近100%。经吸附-解吸6次,Glu-CS/Fe_(3)O_(4)对Cr(Ⅵ)的吸附量仅降低14.4%,具有良好的再生性能。通过吸附动力学研究发现,该吸附过程符合准二级动力学方程。根据等温吸附方程拟合试验结果可知,Glu-CS/Fe_(3)O_(4)对Cr(Ⅵ)的吸附过程符合Langmuir等温吸附方程特征,40℃时实际饱和吸附量为130.3 mg/g,属于单分子层化学吸附。To enhance the adsorption capacity of chitosan(CS)for Cr(Ⅵ),the cross-linked magnetic chitosan modified by grafting with glutamic acid(Glu-CS/Fe_(3)O_(4))was synthesized with glutamic acid,chitosan and Fe_(3)O_(4)as raw materials and glutaraldehyde as the crosslinker.The product was characterized by Fourier transform infrared spectroscopy(FTIR),scanning electron microscopy(SEM)and thermogravimetric analysis(TG).The results showed that Glu-CS/Fe_(3)O_(4)was successfully prepared.When 0.075 g of Glu-CS/Fe_(3)O_(4)was added in 50 mL of 100 mg/L Cr(Ⅵ)solution(pH 3.0)for static adsorption at 40℃for 120 min,the adsorption efficiency for Cr(Ⅵ)was close to 100%.The adsorption capacity of Glu-CS/Fe_(3)O_(4)for Cr(Ⅵ)only decreased by 14.4%after adsorption-desorption for 6 times,indicating that it had good performance of recyclability.Through the study of adsorption kinetics and isothermal adsorption equation fitting test,it was found that the adsorption process of Glu-CS/Fe_(3)O_(4)for Cr(Ⅵ)accorded with the characteristics of quasi-second-order kinetic equation and Langmuir isotherm adsorption model.The actual saturated adsorption capacity at 40℃was 130.3 mg/g.This process belonged to monolayer chemisorption.

关 键 词：谷氨酸 交联磁性壳聚糖 接枝改性 铬(Ⅵ) 吸附性能 

分 类 号：O647[理学—物理化学] X703.5[理学—化学]