Pb2+ adsorption by ethylenediamine-modified pectins and their adsorption mechanisms

Rui-Hong Liang; Ya Li; Li Huang; Xue-Dong Wang; Xiao-Xue Hu; Cheng-Mei Liu; Ming-Shun Chen; Jun Chen

doi:10.1016/j.carbpol.2020.115911

Pb²⁺ adsorption by ethylenediamine-modified pectins and their adsorption mechanisms

Carbohydr Polym. 2020 Apr 15:234:115911. doi: 10.1016/j.carbpol.2020.115911. Epub 2020 Jan 25.

Authors

Rui-Hong Liang¹, Ya Li¹, Li Huang², Xue-Dong Wang¹, Xiao-Xue Hu¹, Cheng-Mei Liu¹, Ming-Shun Chen³, Jun Chen⁴

Affiliations

¹ State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi, 330047, China.
² Nanchang Institute for Control of Food and Drug, Nanchang, Jiangxi, 330047, China.
³ State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi, 330047, China. Electronic address: chenshun1221@163.com.
⁴ State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi, 330047, China. Electronic address: chen-jun1986@hotmail.com.

PMID: 32070530
DOI: 10.1016/j.carbpol.2020.115911

Abstract

Ethylenediamine-modified pectins (EPs) with different degrees of amidation (DA) were prepared and characterized by Fourier Transform Infrared spectra (FTIR), elemental analysis, X-ray photoelectron spectroscopy (XPS). The prepared EPs were then used to remove Pb²⁺ from the aqueous solution. It was found that EPs with the highest DA (EP₄₈) exhibited great removal efficiency of Pb²⁺ (≥94 %) at low concentrations of 40-80 mg/L. The zeta potential analysis showed that EP₄₈ had the fastest increase in zeta potential when Pb²⁺ was continuously added and was the first to be electroneutralized. Particle size analysis further confirmed that EP₄₈ was the first precipitated and formed a larger EP₄₈-Pb²⁺ complex. The FTIR and XPS analyses indicated that Pb²⁺ was adsorbed via the ion exchange of carboxylic groups and chelation with acylamino and amino groups. These results suggested that the EP₄₈ might be a promising adsorbent for the removal of low concentrations of Pb²⁺ in contaminated water.

Keywords: Adsorption; Ethylenediamine; Modification; Pb(2+); Pectin.