High-efficiency removal of lead from wastewater by biochar derived from anaerobic digestion sludge

Shih-Hsin Ho; Yi-di Chen; Zhong-Kai Yang; Dillirani Nagarajan; Jo-Shu Chang; Nan-Qi Ren

doi:10.1016/j.biortech.2017.08.025

High-efficiency removal of lead from wastewater by biochar derived from anaerobic digestion sludge

Bioresour Technol. 2017 Dec:246:142-149. doi: 10.1016/j.biortech.2017.08.025. Epub 2017 Aug 7.

Authors

Shih-Hsin Ho¹, Yi-di Chen¹, Zhong-Kai Yang¹, Dillirani Nagarajan², Jo-Shu Chang³, Nan-Qi Ren⁴

Affiliations

¹ State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, PR China.
² Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan; Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan.
³ State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, PR China; Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan; Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan, Taiwan.
⁴ State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, PR China. Electronic address: rnq@hit.edu.cn.

PMID: 28811160
DOI: 10.1016/j.biortech.2017.08.025

Abstract

The properties of biochar derived from waste activated sludge and anaerobic digestion sludge under pyrolysis temperature varying from 400°C to 800°C were investigated. The heavy metals adsorption efficiency of the sludge-derived biochar was also examined. Among the biochar samples tested, ADSBC600 possessing highly porous structure, special surface chemical behaviors and high thermal stability was found to remove Pb²⁺ from aqueous solutions efficiently with an adsorption capacity of 51.20mg/g. The Pb²⁺ adsorption kinetics and isotherm for ADSBC600 can be described using the pseudo second-order model and Langmuir isotherm, respectively. Analysis of the characteristics of biochar before and after metal treatment suggests that electrostatic attraction, precipitation, surface complexation and ion exchange are the possible Pb²⁺ removal mechanisms. This study demonstrates a successful example of waste refinery by converting anaerobic digestion sludge to feasible heavy metal adsorbents to implement the concept of circular economy.

Keywords: Anaerobic digestion sludge; Biochar; Heavy metals removal.

MeSH terms

Adsorption
Charcoal*
Lead
Sewage
Wastewater*

Substances

Sewage
Waste Water
biochar
Charcoal
Lead