Adsorption of Cr(Ⅵ) by Quaternary Ammonium Lignin
Received:November 29, 2021   Revised:December 07, 2021   Accepted:December 13, 2021      Published Online:March 15, 2022
View Full Text  View/Add Comment  Download reader
DOI:doi:10.3969/j.issn.1007-7545.2022.04.015
KeyWord:chromium; quaternary ammonium lignin; adsorption mechanism; adsorption behavior
           
AuthorInstitution
ZHANG Bao-ping 武汉科技大学 省部共建耐火材料与冶金国家重点实验室
XIAO Yu-kun 武汉科技大学 省部共建耐火材料与冶金国家重点实验室
ZHANG Heng 武汉科技大学 省部共建耐火材料与冶金国家重点实验室
WANG Yin 武汉科技大学 省部共建耐火材料与冶金国家重点实验室
Hits: 1567
Download times: 1842
Abstract:
      Cr(Ⅵ) was adsorbed by quaternary ammonium lignin prepared from straw. The mechanism of adsorption was revealed by FTIR and XPS analysis of quaternary ammonium lignin before and after adsorption. Effects of initial concentration of Cr(Ⅵ), temperature, time and initial pH value on adsorption were investigated. The results show that Cr(Ⅵ) is adsorbed mainly by quaternary ammonium and amino in the form of HCrO4-. Part of adsorbed HCrO4- is reduced to Cr(Ⅲ) by alkyl groups and phenolic hydroxyl groups on the benzene ring and absorbed latter by carboxyl groups. A small amount of Cr(Ⅵ) is directly reduced to Cr(Ⅲ) by electron donating functional groups. When initial concentration of Cr(Ⅵ) is 50 mg/L, initial pH value is 1.08, adsorption time is 120 min and temperature is 25 ℃, the removal rate of Cr(Ⅵ) is 99.76%. The adsorption follows the quasi-second-order kinetics and Langmuir models, which indicates that the adsorption is monolayer homogeneous chemisorptions. The research on mechanism and behavior of Cr(Ⅵ) adsorption by quaternary ammonium lignin can provide theoretical basis for resource utilization of rice and removal of chromium.
Close