Modified sequential extraction for biochar and petroleum coke: Metal release potential and its environmental implications

Konstantin von Gunten, Md Samrat Alam, Magdalena Hubmann, Yong Sik Ok, Kurt O. Konhauser, Daniel S. Alessi

Research output: Contribution to journalArticle

21 Citations (Scopus)


A modified Community Bureau of Reference (CBR) sequential extraction method was tested to assess the composition of untreated pyrogenic carbon (biochar) and oil sands petroleum coke. Wood biochar samples were found to contain lower concentrations of metals, but had higher fractions of easily mobilized alkaline earth and transition metals. Sewage sludge biochar was determined to be less recalcitrant and had higher total metal concentrations, with most of the metals found in the more resilient extraction fractions (oxidizable, residual). Petroleum coke was the most stable material, with a similar metal distribution pattern as the sewage sludge biochar. The applied sequential extraction method represents a suitable technique to recover metals from these materials, and is a valuable tool in understanding the metal retaining and leaching capability of various biochar types and carbonaceous petroleum coke samples.

Original languageEnglish
Pages (from-to)106-110
Number of pages5
JournalBioresource Technology
Publication statusPublished - 2017 Jan 1
Externally publishedYes



  • Agriculture
  • Biochar digestion
  • Contaminants
  • Metal release
  • Sequential extraction

ASJC Scopus subject areas

  • Bioengineering
  • Environmental Engineering
  • Renewable Energy, Sustainability and the Environment
  • Waste Management and Disposal

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