Synchronous removal of Cr(VI) and phosphates by a novel crayfish shell biochar-Fe composite from aqueous solution: Reactivity and mechanism

Liu Yan, Fu Xin Dong, Yu Li, Peng Ran Guo, Ling Jun Kong, Wei Chu, Zeng Hui Diao

Research output: Journal article publicationJournal articleAcademic researchpeer-review


Nowadays, a great increasing attention has been paid to the coexistence of multiple inorganic pollutants in the environment. In this study, a novel crayfish shell biochar-Fe composite (FXB) was successfully produced and effectively used for the synchronous removal of Cr(VI) and phosphates (P) from aqueous solution. Experimental results revealed that FXB exhibited a high performance on the removal of Cr(VI) and P over a broader pH range. The escalating ionic strength and anions like Cl- and NO3- showed varying degrees of inhibition effects on Cr(VI) and P removal. The kinetic model of both Cr(VI) and P adsorption fit better with the pseudo-second-order model compared with the pseudo-first-order model. The isotherm of Cr(VI) fit well with the Langmuir model, whereas that of P adsorption fit well with the Freundlich model. Elovich model suggests that both Cr(VI) and P adsorption were the heterogeneous and multi-mechanism processes, and the intra-particle diffusion model confirms that these adsorption processes were dominated by surface and intra-particle diffusion reactions. Both Cr(VI) and P adsorption onto FXB were the spontaneous and endothermic nature. The synchronous removal of Cr(VI) and P could be efficiently achieved using this FXB composite under the certain conditions. A possible reaction mechanism for the synchronous adsorption of Cr(VI) and P onto FXB involving the synergistic effects of surface adsorption, precipitation, reduction and complexation processes was proposed.

Original languageEnglish
Article number107396
JournalJournal of Environmental Chemical Engineering
Issue number2
Publication statusPublished - Apr 2022


  • Adsorption
  • Biochar
  • Cr(VI)
  • Phosphates
  • Synchronous removal

ASJC Scopus subject areas

  • Chemical Engineering (miscellaneous)
  • Waste Management and Disposal
  • Pollution
  • Process Chemistry and Technology

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