A novel self-crosslinked gel microspheres of Premna microphylla turcz leaves for the absorption of uranium

Hongying Gong; Xiaoyan Lin; Yu Xie; Lan Liu; Jian Zhou; Hui Liao; Ran Shang; Xuegang Luo

doi:10.1016/j.jhazmat.2020.124151

A novel self-crosslinked gel microspheres of Premna microphylla turcz leaves for the absorption of uranium

J Hazard Mater. 2021 Feb 15;404(Pt A):124151. doi: 10.1016/j.jhazmat.2020.124151. Epub 2020 Sep 30.

Authors

Hongying Gong¹, Xiaoyan Lin², Yu Xie³, Lan Liu¹, Jian Zhou³, Hui Liao³, Ran Shang⁴, Xuegang Luo¹

Affiliations

¹ School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, Sichuan, China; Engineering Research Center of Biomass Materials, Ministry of Education, Mianyang 621010, Sichuan, China.
² School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, Sichuan, China; Engineering Research Center of Biomass Materials, Ministry of Education, Mianyang 621010, Sichuan, China. Electronic address: lxy20100205@163.com.
³ Engineering Research Center of Biomass Materials, Ministry of Education, Mianyang 621010, Sichuan, China.
⁴ State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.

PMID: 33032091
DOI: 10.1016/j.jhazmat.2020.124151

Abstract

Premna microphylla turcz leaves (PMTL) is a resource-rich, biodegradable, renewable biomass. Here, a microsphere adsorbent was prepared from PMTL by a self-crosslinking method without any addition of chemical cross-linking agent, and characterized by SEM, FTIR, and XPS. The influence of preparation methods and conditions on the properties of the microspheres was studied and the self-crosslinking mechanism was analyzed. The effects of temperature, pH, contact time, uranium concentration, and adsorbent dosage on its adsorption performance toward to uranium were systematically explored. The results showed that PMTL endogenous pectin binding with endogenous Ca²⁺, Mg²⁺ and other metal ions to form an 'egg box' structure might be the mechanism of its self-crosslinking to form microspheres. The adsorption isotherms fitted well by the Freundlich model and the experimental maximum adsorption capacity of microspheres was 346.65 mg·g^-1 at pH of 5, and kinetics data correlated well with the pseudo-second order model. The adsorption mechanism might be the coordination bonding between the uranium and oxygen-containing groups (hydroxyl and carboxyl groups), and the ion exchange between the uranium and metal ions (mainly Ca²⁺ and Mg²⁺). The PMTL microspheres are promising in treating uranium-containing wastewater in a more cost-effective and environmentally friendly manner.

Keywords: Adsorption; Premna microphylla turcz leaves; Self-crosslinking; Uranium.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adsorption
Hydrogen-Ion Concentration
Kinetics
Microspheres
Plant Leaves
Uranium*

Substances

Uranium