Enhanced reactivity of iron monosulfide towards reductive transformation of tris(2-chloroethyl) phosphate in the presence of cetyltrimethylammonium bromide

Dan Li, Yin Zhong, Xifen Zhu, Heli Wang, Weiqiang Yang, Yirong Deng, Weilin Huang, Ping'an Peng

Research output: Contribution to journalArticle

Abstract

Tris(2-chloroethyl) phosphate (TCEP) is a widely found emerging pollutant due to its heavy usage as a flame retardant. It is chemically stable and is very difficult to removal from water. The goal of this study was to explore whether iron monosulfide (FeS) can be used for reductive transformation of TCEP as FeS can react with a variety of halogenated organic contaminants. We used batch reactor systems to quantify the transformation reactions in the absence and presence of cetyltrimethylammonium bromide (CTAB, a common surfactant in aquatic environments). The results showed that, in the presence of CTAB (100 mg L−1), FeS exhibited much greater reactivity towards TCEP as 93% of initial TCEP had been transformed within 14 d of reaction. In the absence of CTAB, it required 710 d of reaction to achieve 97.3% reduction of initial TCEP. The enhancement of CTAB on TCEP transformation rate could be due to the facts that CTAB could stabilize FeS suspension against aggregation, protect FeS from rapid oxidation, and increase surface adsorption of TCEP on FeS. XPS analysis showed that both Fe(II) and S(-II) species on the FeS surface were involved in the reductive transformation of TCEP. Analysis of transformation products revealed that TCEP was reductively transformed into bis(2-chloroethyl) phosphate (BCEP), Cl and C2H4. These findings showed that FeS may play an important role in the reductive transformation of TCEP when TCEP coexisting with CTAB in aquatic environments.

Original languageEnglish (US)
Article number114282
JournalEnvironmental Pollution
Volume262
DOIs
StatePublished - Jul 2020

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All Science Journal Classification (ASJC) codes

  • Toxicology
  • Pollution
  • Health, Toxicology and Mutagenesis

Keywords

  • CTAB
  • FeS
  • Mechanism
  • TCEP
  • Transformation

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