Removal of heavy metals from wastewaters with biochar pyrolyzed from MgAl-layered double hydroxide-coated rice husk: Mechanism and application

Anyu Li; Yue Zhang; Wenzhan Ge; Yutong Zhang; Lihu Liu; Guohong Qiu

doi:10.1016/j.biortech.2021.126425

Removal of heavy metals from wastewaters with biochar pyrolyzed from MgAl-layered double hydroxide-coated rice husk: Mechanism and application

Bioresour Technol. 2022 Mar:347:126425. doi: 10.1016/j.biortech.2021.126425. Epub 2021 Nov 25.

Authors

Anyu Li¹, Yue Zhang¹, Wenzhan Ge¹, Yutong Zhang¹, Lihu Liu¹, Guohong Qiu²

Affiliations

¹ Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural Affairs, Hubei Key Laboratory of Soil Environment and Pollution Remediation, State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Interdisciplinary Sciences Institute, Huazhong Agricultural University, Wuhan 430070, Hubei Province, China.
² Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural Affairs, Hubei Key Laboratory of Soil Environment and Pollution Remediation, State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Interdisciplinary Sciences Institute, Huazhong Agricultural University, Wuhan 430070, Hubei Province, China. Electronic address: qiugh@mail.hzau.edu.cn.

PMID: 34838973
DOI: 10.1016/j.biortech.2021.126425

Abstract

This study reports a MgAl-LDH rice husk biochar composite (MgAl-LDH@RHB) with a regular hydrotalcite structure synthesized by a simple hydrothermal method, which was then used to remove Cd(II) and Cu(II) from water. The influencing factors on the adsorption performance were determined through batch adsorption experiments, and the adsorption characteristics and cycling capacity were evaluated with eight models and adsorption-desorption experiments. The results showed that the adsorption of Cd(II) and Cu(II) by MgAl-LDH@RHB conformed to the Langmuir-Freundlich model and PSO kinetics model, indicating single-layer chemical adsorption. In addition, the experimental maximum adsorption capacities for Cd(II) and Cu(II) were 125.34 and 104.34 mg g^-1, respectively. The adsorption of Cd(II) and Cu(II) by MgAl-LDH@RHB was dominated by surface precipitation and ion exchange. The findings reveal the mechanism for the heavy metal removal by MgAl-LDH@RHB and provide a theoretical reference for agricultural waste disposal and water pollution control.

Keywords: Adsorption; Heavy metals; Layered double hydroxides; Mechanisms; Rice husk biochar.

MeSH terms

Adsorption
Charcoal
Hydroxides
Kinetics
Metals, Heavy*
Oryza*
Wastewater
Water Pollutants, Chemical* / analysis

Substances

Hydroxides
Metals, Heavy
Waste Water
Water Pollutants, Chemical
biochar
Charcoal