title: Reductive transformation of tetrabromobisphenol A by sulfidated nano zerovalent iron.
abstract: Recent studies showed that sulfidated nano zerovalent iron (S-nZVI) is a better alternative to non-sulfidated nano zerovalent iron (NS-nZVI) commonly used for contaminated site remediation. However, its reactivity with different halogenated pollutants such as tetrabromobisphenol A (TBBPA) remains unclear. In this study, we explored the reductive transformation of TBBPA by S-nZVI and compared it with that by NS-nZVI. The results showed that over 90% of the initial TBBPA (20 mg L(-1)) was transformed by S-nZVI within 24 h of reaction, which was 1.65 times as high as that for NS-nZVI. The TBBPA transformation by S-nZVI was well described by a pseudo-first-order kinetic model, whilst that by NS-nZVI was well fitted by a three-parameter single exponential decay model. After 11 weeks of aging, S-nZVI was still able to transform up to 56% of the initial TBBPA within 24 h of reaction; by contrast, the two-week aged NS-nZVI lost more than 95% of its original capacity to transform TBBPA. Moreover, S-nZVI showed only an approximately 20% decrease in its capacity to transform TBBPA in the seventh cycle, while NS-nZVI was no longer able to transform TBBPA in the fourth cycle. XPS analysis suggested the formation of FeS layer on S-nZVI surface and electrochemical analysis revealed an elevated electron transfer capacity of S-nZVI, which were likely responsible for the superior performances of S-nZVI in TBBPA transformation. While the transformation rate of TBBPA by S-nZVI decreased with increasing initial concentration of TBBPA, it showed an increasing trend with increasing S/Fe ratio and initial concentration of S-nZVI. The study indicated that S-nZVI has the potential to be a promising alternative to NS-nZVI for remediation of TBBPA-contaminated aquatic environments.
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Mao
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, Guangzhou 510640, China. Electronic address: zhongyin@gig.ac.cn.
authors.forename: Yin
authors.initials: Y
authors.lastname: Zhong
authors.affiliation: Department of Environmental Sciences Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, NJ 08901, USA.
authors.forename: Weilin
authors.initials: W
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, Guangzhou 510640, China; Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Yundang
authors.initials: Y
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, Guangzhou 510640, China.
authors.forename: Ping'an
authors.initials: P
authors.lastname: Peng
mesh_terms: D007501:Iron; D007700:Kinetics; D014873:Water Pollutants / Q000737:chemistry*
chemical_list: D014873:Water Pollutants; D007501:Iron
keywords: Aging; Reusability; S-nZVI; Sulfidation; TBBPA; Transformation pattern