Effect of deashing on activation process and lead adsorption capacities of sludge-based biochar

Junjie Zhang; Jingai Shao; Qianzheng Jin; Xiong Zhang; Haiping Yang; Yingquan Chen; Shihong Zhang; Hanping Chen

doi:10.1016/j.scitotenv.2020.137016

Effect of deashing on activation process and lead adsorption capacities of sludge-based biochar

Sci Total Environ. 2020 May 10:716:137016. doi: 10.1016/j.scitotenv.2020.137016. Epub 2020 Jan 30.

Authors

Junjie Zhang¹, Jingai Shao², Qianzheng Jin³, Xiong Zhang¹, Haiping Yang¹, Yingquan Chen¹, Shihong Zhang¹, Hanping Chen⁴

Affiliations

¹ State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
² State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China; Department of New Energy Science and Engineering, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China. Electronic address: jashao@hust.edu.cn.
³ School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
⁴ State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China; Department of New Energy Science and Engineering, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.

PMID: 32036135
DOI: 10.1016/j.scitotenv.2020.137016

Abstract

To explore the effect of inorganic minerals on activation process and lead adsorption of sludge-based biochar, sludge-based biochar was pre-deashed using hydrochloric acid or hydrofluoric acid followed by potassium acetate activation. The results indicate that hydrochloric or hydrofluoric acid deashing can improve the pore parameters of sludge-based biochars and promote subsequent activation effect of potassium acetate. The specific surface area of biochar activated by potassium acetate after hydrochloric acid and hydrofluoric acid pretreatment increased from 583.36 m²/g to 718.70 m²/g and 991.55 m²/g, respectively. The enhancement of pore structure is conducive to enhancing the physical adsorption of lead on sludge-based biochar, while the chemical adsorption is not significantly affected at the same time. Thereby, the biochar and activated biochar pretreated with hydrofluoric acid showed better lead adsorption capacities (16.70 and 49.47 mg/g) than untreated biochar (7.56 and 38.49 mg/g).

Keywords: Biochar; Deashing; Lead adsorption; Sludge.

MeSH terms

Adsorption
Charcoal
Lead
Sewage*

Substances

Sewage
biochar
Charcoal
Lead