DOI: 10.1016/j.watres.2018.08.033
Scopus记录号: 2-s2.0-85053125903
论文题名: Strong chromate-adsorbent based on pyrrolic nitrogen structure: An experimental and theoretical study on the adsorption mechanism
作者: Ko Y.-J. ; Choi K. ; Lee S. ; Jung K.-W. ; Hong S. ; Mizuseki H. ; Choi J.-W. ; Lee W.-S.
刊名: Water Research
ISSN: 431354
出版年: 2018
卷: 145 起始页码: 287
结束页码: 296
语种: 英语
英文关键词: Chromate adsorption
; First-principles calculation
; Jones oxidation
; Polarization screening
; Pyrrolic nitrogen
Scopus关键词: Adsorbents
; Calculations
; Carbon black
; Chromate coatings
; Chromates
; Density functional theory
; Health risks
; High resolution transmission electron microscopy
; Hydrogen bonds
; Nitrogen
; Polypyrroles
; Solutions
; Transmission electron microscopy
; X ray photoelectron spectroscopy
; Adsorption capacities
; Adsorption mechanism
; Energy filtered transmission electron microscopy
; First-principles calculation
; Ph dependent adsorptions
; Polypyrrole coatings
; Pyrrolic nitrogen
; Water and wastewater
; Adsorption
; adsorption
; chromate
; health risk
; nitrogen
; oxidation
; physicochemical property
; pollutant removal
; water pollution
; Animalia
英文摘要: Chromate is considered a toxic contaminant in various water sources because it poses a risk to animal and human health. To meet the stringent limits for chromium in water and wastewater, pyrrolic nitrogen structure was investigated as a chromate adsorbent for aqueous solutions, employing a polypyrrole coating on carbon black. The characteristics of the adsorbent were analyzed by high-resolution transmission electron microscopy, energy-filtered transmission electron microscopy, and X-ray photoelectron spectroscopy. Chromate was adsorbed as both Cr(III) and Cr(VI). The chromate adsorption capacity increased (from 50.84 to 174.81 mg/g) with increasing amounts of pyrrole monomers (from 50 to 86%) in the adsorbent. The adsorption capacity was well-correlated with the pyrrolic nitrogen content (from 2.06 to 6.57 at%) in the adsorbent, rather than other types of nitrogen. The optimized adsorption capacity (174.81 mg/g in the equilibrium batch experiment and 211.10 mg/g at an initial pH of 3) was far superior to those of conventional adsorbents. We investigated the mechanism behind this powerful chromate adsorption on pyrrolic nitrogen via physical/chemical analyses of the pH-dependent adsorption behavior, supported by first-principles calculation based on density functional theory. We found that Cr(III) and Cr(VI) adsorption followed different reaction paths. Cr(III) adsorption occurred in two sequential steps: 1) A Jones oxidation reaction (JOR)-like reaction of Cr(VI) with pyrrolic N that generates Cr(III), and 2) Cr(III) adsorption on the deprotonated pyrrolic N through Cr(III)–N covalent bonding. Cr(VI) adsorption followed an alternative path: hydrogen-bonding to the deprotonation-free pyrrolic N sites. The pH-dependent fractional deprotonation of the pyrrolic N sites by the JOR-like reaction in the presence of chromate played an important role in the adsorption. © 2018 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112450
Appears in Collections: 气候减缓与适应
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作者单位: Center for Electronic Materials, Korea Institute of Science and Technology, Hwarang-ro 14-gil 5, Seongbuk-gu, Seoul, 02792, South Korea; School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, UNIST-gil, Ulsan, 44919, South Korea; Department of Earth and Environmental Sciences, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, South Korea; Center for Water Resource Cycle Research, Korea Institute of Science and Technology, Hwarang-ro 14-gil 5, Seongbuk-gu, Seoul, 02792, South Korea; Computational Science Research Center, Korea Institute of Science and Technology, Hwarang-ro 14-gil 5, Seongbuk-gu, Seoul, 02792, South Korea; Division of Energy & Environment Technology, KIST School, Korea University of Science and Technology, Hwarang-ro 14-gil 5, Seongbuk-gu, Seoul, 02792, South Korea
Recommended Citation:
Ko Y.-J.,Choi K.,Lee S.,et al. Strong chromate-adsorbent based on pyrrolic nitrogen structure: An experimental and theoretical study on the adsorption mechanism[J]. Water Research,2018-01-01,145