Fabrication and environmental applications of multifunctional mixed metal-biochar composites (MMBC) from red mud and lignin wastes

Dong Wan Cho, Kwangsuk Yoon, Yongtae Ahn, Yuqing Sun, Daniel C.W. Tsang, Deyi Hou, Yong Sik Ok, Hocheol Song

Research output: Journal article publicationJournal articleAcademic researchpeer-review

98 Citations (Scopus)


This study fabricated a new and multifunctional mixed metal-biochar composites (MMBC) using the mixture of two abundant industrial wastes, red mud (RM) and lignin, via pyrolysis under N2 atmosphere, and its ability to treat wastewater containing various contaminants was comprehensively evaluated. A porous structure (BET surface area = 100.8 m2 g−1) was created and metallic Fe was formed in the MMBC owing to reduction of Fe oxides present in RM by lignin decomposition products during pyrolysis at 700 °C, which was closely associated with the transformation of liquid to gaseous pyrogenic products. The potential application of the MMBC was investigated for the removal of heavy metals (Pb(II) and Ni(II)), oxyanions (As(V) and Cr(VI)), dye (methylene blue), and pharmaceutical/personal care products (para-nitrophenol and pCBA). The aluminosilicate mineral, metallic Fe, and porous carbon matrix derived from the incorporation of RM and lignin contributed to the multifunctionality (i.e., adsorption, chemical reduction, and catalytic reaction) of the MMBC. Thus, engineered biochar composites synthesized from selected industrial wastes can be a potential candidate for environmental applications.

Original languageEnglish
Pages (from-to)412-419
Number of pages8
JournalJournal of Hazardous Materials
Publication statusPublished - 15 Jul 2019


  • Bauxite residue
  • Engineered biochar
  • Metallic iron-carbon composites
  • Syngas production
  • Waste biomass valorization

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • Waste Management and Disposal
  • Pollution
  • Health, Toxicology and Mutagenesis

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