Removal of heavy metal ions and polybrominated biphenyl ethers by sulfurized nanoscale zerovalent iron: Compound effects and removal mechanism

Xipeng Wei; Zhanyu Guo; Hua Yin; Yibo Yuan; Ruxia Chen; Guining Lu; Zhi Dang

doi:10.1016/j.jhazmat.2021.125555

Removal of heavy metal ions and polybrominated biphenyl ethers by sulfurized nanoscale zerovalent iron: Compound effects and removal mechanism

J Hazard Mater. 2021 Jul 15:414:125555. doi: 10.1016/j.jhazmat.2021.125555. Epub 2021 Mar 2.

Authors

Xipeng Wei¹, Zhanyu Guo¹, Hua Yin², Yibo Yuan¹, Ruxia Chen¹, Guining Lu¹, Zhi Dang¹

Affiliations

¹ Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, School of Environment and Energy, South China University of Technology, Guangzhou 510006, Guangdong, China.
² Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters, Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, School of Environment and Energy, South China University of Technology, Guangzhou 510006, Guangdong, China. Electronic address: huayin@scut.edu.cn.

PMID: 33684814
DOI: 10.1016/j.jhazmat.2021.125555

Abstract

Sulfurized nanoscale zerovalent iron (S-nZVI) has been widely reported to be able to quickly remove heavy metals/persistent organic pollutants, but the limited understanding of the complicated removal process of heavy metals-organic combined pollutants restricts the application of S-nZVI. Here, we demonstrate that there is significant difference in the effectiveness of S-nZVI for removing single pollutant and complex pollutants. The removal kinetic constant (k_obs) of heavy metals by S-nZVI followed a sequence of Cr(VI)>Pb(II)>Ni(II)>Cd(II) with or without polybrominated diphenyl ethers (PBDEs). While the capacity of co-existing cations increasing the k_obs of PBDEs followed the order: Ni(II)>Pb(II)>Cd(II), and the co-existence of Cr(VI) anion inhibited the reduction of PBDE by S-nZVI because the generated Cr-Fe precipitate hindered the electron transfer. The de-passivation process on S-nZVI surface by Cd(II) ions slightly accelerated the transformation rate of electron. Nevertheless, the co-existing Pb(II) significantly accelerated the transformation of BDE-209 via the galvanic effect from the generated Pb⁰/Fe⁰ bimetal. Interestingly, the k_obs of BDE-47 in Ni(II)/S-nZVI system was 5.51 times higher than that of Pb(II)/S-nZVI system, implying that an atomic hydrogen mechanism dominated the reduction of BDE-47 by Ni(II)/S-nZVI. In conclusion, the results provided a deep comprehending of removal mechanism of heavy metal-organic complex pollutants by S-nZVI.

Keywords: Heavy metal ions; Polybrominated diphenyl ethers; Reductive reaction; S-nZVI.

Publication types

Research Support, Non-U.S. Gov't