Simultaneous removal of cadmium and nitrate in aqueous media by nanoscale zerovalent iron (nZVI) and Au doped nZVI particles

Yiming Su; Adeyemi S Adeleye; Yuxiong Huang; Xiaoya Sun; Chaomeng Dai; Xuefei Zhou; Yalei Zhang; Arturo A Keller

doi:10.1016/j.watres.2014.06.008

Simultaneous removal of cadmium and nitrate in aqueous media by nanoscale zerovalent iron (nZVI) and Au doped nZVI particles

Water Res. 2014 Oct 15:63:102-11. doi: 10.1016/j.watres.2014.06.008. Epub 2014 Jun 19.

Authors

Yiming Su¹, Adeyemi S Adeleye², Yuxiong Huang³, Xiaoya Sun⁴, Chaomeng Dai⁵, Xuefei Zhou⁴, Yalei Zhang⁶, Arturo A Keller⁷

Affiliations

¹ State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China; Bren School of Environmental Science & Management, University of California, Santa Barbara, 3420 Bren Hall, CA 93106, USA; University of California Center for Environmental Implications of Nanotechnology, Santa Barbara, CA, USA.
² Bren School of Environmental Science & Management, University of California, Santa Barbara, 3420 Bren Hall, CA 93106, USA; University of California Center for Environmental Implications of Nanotechnology, Santa Barbara, CA, USA.
³ Bren School of Environmental Science & Management, University of California, Santa Barbara, 3420 Bren Hall, CA 93106, USA.
⁴ State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China.
⁵ State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China; College of Civil Engineering, Tongji University, Shanghai 200092, China.
⁶ State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China; Key Laboratory of Yangtze Water Environment for Ministry of Education, Tongji University, Shanghai 200092, China. Electronic address: zhangyalei@tongji.edu.cn.
⁷ Bren School of Environmental Science & Management, University of California, Santa Barbara, 3420 Bren Hall, CA 93106, USA; University of California Center for Environmental Implications of Nanotechnology, Santa Barbara, CA, USA. Electronic address: keller@bren.ucsb.edu.

PMID: 24999115
DOI: 10.1016/j.watres.2014.06.008

Abstract

Nanoscale zerovalent iron (nZVI) has demonstrated high efficacy for treating nitrate or cadmium (Cd) contamination, but its efficiency for simultaneous removal of nitrate and Cd has not been investigated. This study evaluated the reactivity of nZVI to the co-contaminants and by-product formation, employed different catalysts to reduce nitrite yield from nitrate, and examined the transformation of nZVI after reaction. Nitrate reduction resulted in high solution pH, negatively charged surface of nZVI, formation of Fe3O4 (a stable transformation of nZVI), and no release of ionic iron. Increased pH and negative charge contributed to significant increase in Cd(II) removal capacity (from 40 mg/g to 188 mg/g) with nitrate present. In addition, nitrate reduction by nZVI could be catalyzed by Cd(II): while 30% of nitrate was reduced by nZVI within 2 h in the absence of Cd(II), complete nitrate reduction was observed in the presence of 40 mg-Cd/L due to the formation of Cd islands (Cd(0) and CdO) on the nZVI particles. While nitrate was reduced mostly to ammonium when Cd(II) was not present or at Cd(II) concentrations ≥ 40 mg/L, up to 20% of the initial nitrate was reduced to nitrite at Cd(II) concentrations < 40 mg/L. Among nZVI particles doped with 1 wt. % Cu, Ag, or Au, nZVI deposited with 1 wt. % Au reduced nitrite yield to less than 3% of the initial nitrate, while maintaining a high Cd(II) removal capacity.

Keywords: Bimetallic nanoparticles; Cd removal; Nanoscale zerovalent iron; Nitrate reduction.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cadmium / chemistry*
Copper / chemistry
Gold / chemistry
Iron / chemistry*
Metal Nanoparticles / chemistry*
Nitrates / chemistry*
Nitrites / analysis
Silver / chemistry
Waste Disposal, Fluid / methods*
Water Pollutants, Chemical / chemistry*
X-Ray Diffraction

Substances

Nitrates
Nitrites
Water Pollutants, Chemical
Cadmium
Silver
Gold
Copper
Iron