单宁基酚胺型螯合树脂的制备及对Cr(VI)的吸附

Preparation of phenol-amine chelating resin based on tannin and the adsorption of Cr(VI)

摘要:

杨梅单宁先与氯化亚砜反应制得氯代单宁，再与聚乙烯亚胺交联合成单宁基酚胺型螯合树脂。通过FTIR、SEM、EDS和XPS对单宁基酚胺型螯合树脂的结构进行表征，并考察了螯合树脂对Cr(VI)的吸附性能。在单宁的分子结构侧链引入氨基，能有效改善单宁基螯合树脂对Cr(VI)的吸附性能，螯合树脂对Cr(VI)的吸附主要为还原吸附，铬主要以Cr(III)的形式吸附到树脂上；在温度为318 K、pH为2.0、Cr(VI)初始质量浓度为500 mg/L时，单宁基酚胺型螯合树脂对Cr(VI)的最大吸附量达到364.46 mg/g；当Cr(VI)初始质量浓度低于20 mg/L时，树脂对铬的吸附率达到95%以上；单宁基酚胺型螯合树脂对Cr(VI)的吸附过程符合Langmuir等温吸附模型和准二级吸附动力学方程。该树脂在含铬废水处理方面具有潜在的应用前景。

Abstract:

Phenol-amine chelating resin based on tannin was prepared by the cross-linking reaction of polyethylenimine and chlorinated tannin, where chlorinated tannin was synthesized by the reaction of tannins with thionyl chloride. The phenol-amine chelating resin based on tannin was characterized by FTIR, SEM, EDS and XPS, and the adsorption properties of chelating resin based on tannin for Cr(VI) were evaluated. The adsorption properties of the chelating resin based on tannin were effectively improved owning to the introduction of the amino group into the side chain of tannin molecular structure. The adsorption of Cr(VI) by the chelating resin based on tannin is mainly reduction adsorption, which is mainly adsorbed on the resin in the form of Cr(III). The maximum adsorption capacity of the resin for Cr(VI) was 364.46 mg/g at 318 K and pH 2.0 when initial concentration of Cr(VI) was 500 mg/L, and the adsorption rate of resin to Cr was more than 95% when the initial concentration of Cr(VI) was lower than 20 mg/L. The adsorption process of Cr(VI) by the resin can be described by the Langmuir isothermal adsorption model and the pseudo second order kinetic equation. The resin has potential application prospects in the treatment of the wastewater containing chromium.