Enhanced removal performance of magnesium-modified biochar for cadmium in wastewaters: Role of active functional groups, processes, and mechanisms

Anyu Li; Chenghui Ye; Yanhong Jiang; Hua Deng

doi:10.1016/j.biortech.2023.129515

Enhanced removal performance of magnesium-modified biochar for cadmium in wastewaters: Role of active functional groups, processes, and mechanisms

Bioresour Technol. 2023 Oct:386:129515. doi: 10.1016/j.biortech.2023.129515. Epub 2023 Jul 17.

Authors

Anyu Li¹, Chenghui Ye², Yanhong Jiang², Hua Deng³

Affiliations

¹ College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, Hubei Province, China; Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection, Guangxi Normal University, Guilin 541004, China; College of Environment and Resources, Guangxi Normal University, Guilin 541004, China.
² Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection, Guangxi Normal University, Guilin 541004, China; College of Environment and Resources, Guangxi Normal University, Guilin 541004, China.
³ Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection, Guangxi Normal University, Guilin 541004, China; College of Environment and Resources, Guangxi Normal University, Guilin 541004, China. Electronic address: denghua@mailbox.gxnu.edu.cn.

PMID: 37468011
DOI: 10.1016/j.biortech.2023.129515

Abstract

In this study, a series of biochar products with different active functional groups were developed by one-pot coprecipitation method, including magnesium-modified biochar (MgBC) and functional group-grafted MgBC (Cys@MgBC, Try@MgBC, and Glu@MgBC), for effective adsorption of cadmium (Cd(II)) from wastewaters. These biochars exhibited excellent removal performance for Cd(II), particularly Cys@MgBC, whose maximum Cd(II) adsorption capacity reached 223.7 mg g^-1. The highly active and weakly crystalline Mg could adsorb Cd(II) through precipitation and ion exchange, which was further promoted by the introduced functional groups through complexation and precipitation. After 120 d of natural process, the immobilization efficiency of Cd(II) by Cys@MgBC, Try@MgBC, and Glu@MgBC was still maintained at 98.7%, 95.2%, and 82.7% respectively. This study proposes and clarifies the complexation mechanism of functional group-grafted Mg-modified biochar for heavy metals, providing new insights into the practical application of these biochars.

Keywords: Active functional groups; Heavy metal; Long-term stability; Magnesium-modified biochar; Removal mechanisms.

MeSH terms

Adsorption
Cadmium* / chemistry
Charcoal / chemistry
Magnesium
Wastewater*

Substances

Cadmium
biochar
Wastewater
Magnesium
methylglyoxal bis(cyclohexylamidinohydrazone)
Charcoal