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

Abstract

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
Volume10
Issue number2
DOIs
Publication statusPublished - Apr 2022

Keywords

  • 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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