Enhanced reactivity of iron monosulfide towards reductive transformation of tris(2-chloroethyl) phosphate in the presence of cetyltrimethylammonium bromide. (July 2020)

• Record Type: Journal Article
• Authors: Li, Dan; Zhong, Yin; Zhu, Xifen; Wang, Heli; Yang, Weiqiang; Deng, Yirong; Huang, Weilin; Peng, Ping'an
• Is Part Of: Environmental pollution. Volume 262(2020)
• Publication Date: 2020-07
• Subjects: TCEP -- FeS -- CTAB -- Transformation -- Mechanism; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.114282
• Languages: English
• ISSNs: 0269-7491

Abstract

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 C2 H4 . These findings showed that FeS may play an important role in the reductive transformation of TCEP when TCEP coexisting with CTAB in aquatic environments. Graphical abstract: Image 1 Highlights: FeS exhibited low reactivity towards reductive transformation of TCEP. CTAB could accelerate reductive transformation rate of TCEP by FeS. The presence of CTAB could enhance FeS dispersion and protect FeS from oxidation. Dosages of CTAB, FeS and TCEP affected the rates of TCEP transformation. TCEP was reductively transformed to bis(2-chloroethyl) phosphate, Cl − and C2 H4 . Abstract : FeS plays an important role in the reductive transformation of TCEP in the presence of CTAB.