Characterization of bioenergy biochar and its utilization for metal/metalloid immobilization in contaminated soil

Xiao Yang, Avanthi D. Igalavithana, Sang Eun Oh, Hyungseok Nam, Ming Zhang, Chi Hwa Wang, Eilhann E. Kwon, Chiu Wa Tsang, Yong Sik Ok

Research output: Journal article publicationJournal articleAcademic researchpeer-review

60 Citations (Scopus)

Abstract

This study is a comparison of the effect of biochar produced by bioenergy systems, via the pyrolysis and gasification processes, on the immobilization of metals/metalloids in soil. Because the processes for these two techniques vary, the feedstocks undergo different heating regimens and, as a result, their respective char products exhibit different physico-chemical properties. Therefore, this study focuses on (1) the characterization of derivative biochar from the bioenergy system to understand their features and (2) an exploration of various biochar impacts on the mobility of As and Pb in contaminated soil. The results showed bioenergy biochars (BBCs) performed well in mitigating Pb extractability (1 M ammonium acetate) with a Pb immobilization >80%, but unfavorably mobilized the bioavailable As, likely because of electrostatic repulsion and ion exchange competition. The BBC surface functional group would chemically bond with the As and remain stable against the pH change. An increment in aromatic carbon would effectively enhance cation-π interaction for Pb immobilization. Nevertheless, an amendment with richer condensed structure and higher inorganic minerals (Ca 2+, K +, Mg 2+, and Na +) can lead to better performance in retaining Pb.

Original languageEnglish
Pages (from-to)704-713
Number of pages10
JournalScience of the Total Environment
Volume640-641
DOIs
Publication statusPublished - 1 Nov 2018

Keywords

  • Black carbon
  • Chemical stabilization
  • Gasification
  • Slow pyrolysis
  • Soil remediation

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • Waste Management and Disposal
  • Pollution

Cite this