Remarkable promotion in particle dispersion and electron transfer capacity of sulfidated nano zerovalent iron by coating alginate polymer

Dan Li; Yin Zhong; Heli Wang; Weilin Huang; Ping'an Peng

doi:10.1016/j.scitotenv.2020.143481

Remarkable promotion in particle dispersion and electron transfer capacity of sulfidated nano zerovalent iron by coating alginate polymer

Sci Total Environ. 2021 Mar 10:759:143481. doi: 10.1016/j.scitotenv.2020.143481. Epub 2020 Nov 11.

Authors

Dan Li¹, Yin Zhong², Heli Wang³, Weilin Huang⁴, Ping'an Peng⁵

Affiliations

¹ School of Environment and Civil Engineering, Dongguan University of Technology, Dongguan 523808, China; State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, Guangzhou 510640, China. Electronic address: zhongyin@gig.ac.cn.
³ State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ Department of Environmental Sciences, Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, NJ 08901, USA.
⁵ State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, Guangzhou 510640, China.

PMID: 33221003
DOI: 10.1016/j.scitotenv.2020.143481

Abstract

Alginate has been widely employed to increase the performance of nanoscale zerovalent iron (nZVI)-based materials for site remediation. Yet, the effects of alginate on reactivity of sulfidated nZVI (an efficient reductant material) towards contaminants have been understood poorly. In this study, we have developed a one-step synthesis of alginate-coated sulfidated nZVI (S-nZVI@alginate) under air atmosphere and evaluated the reactivity of S-nZVI@alginate towards tetrabromobisphenol A (TBBPA) debromination. Surface analysis shows that S-nZVI has been successfully coated by alginate through the interaction of OH and COO^- groups of alginate with Fe species. The coating of alginate increases particle stability and dispersion under various conditions and facilitates FeS precipitation on the particle surface. Reactivity experiments show that the coating of alginate significantly enhances TBBPA debromination by S-nZVI. The optimized alginate to Fe weight ratio of S-nZVI@alginate is 0.06, with ~3-fold greater TBBPA debromination rate than S-nZVI. S-nZVI@alginate can completely debrominate TBBPA into bisphenol A via a four-sequential step debromination pathway while S-nZVI not. Its superior reactivity may be attributed to that the formation of alginate-Fe complex can lower the redox potential of Fe species to accelerate electron transfer on the particle surface. The TBBPA debromination rate by S-nZVI@alginate is initially enhanced followed by a decrease with an increase in TBBPA concentration, while it can increase 3.3-, 8.9- and 5.6-fold by increasing S-nZVI@alginate dosage, decreasing pH and adding co-contaminant Cd²⁺, respectively. S-nZVI@alginate has greater performance in aging and reusability tests than S-nZVI, and achieves rapid TBBPA removal from wastewater, which may be due to the role of alginate on inhibiting surface oxidation of Fe and S species. Taken together, these results suggest that S-nZVI@alginate provides better reactivity, longevity and reusability than S-nZVI, having the great potential for application into site remediation.

Keywords: Alginate; Debromination; Electron transfer; Oxidation inhibition; Particle dispersion; S-nZVI.