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Nat Commun. 2018 Nov 8;9(1):4701. doi: 10.1038/s41467-018-07159-0.

Electrochemically-mediated selective capture of heavy metal chromium and arsenic oxyanions from water.

Author information

1
Department of Chemical Engineering, MIT, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
2
Department of Nuclear Engineering, MIT, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
3
Department of Materials Science and Engineering, University of Central Florida, 12760 Pegasus Drive, Orlando, FL, 32816, USA.
4
Department of Chemical Engineering, MIT, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA. tahatton@mit.edu.

Abstract

The removal of highly toxic, ultra-dilute contaminants of concern has been a primary challenge for clean water technologies. Chromium and arsenic are among the most prevalent heavy metal pollutants in urban and agricultural waters, with current separation processes having severe limitations due to lack of molecular selectivity. Here, we report redox-active metallopolymer electrodes for the selective electrochemical removal of chromium and arsenic. An uptake greater than 100 mg Cr/g adsorbent can be achieved electrochemically, with a 99% reversible working capacity, with the bound chromium ions released in the less harmful trivalent form. Furthermore, we study the metallopolymer response during electrochemical modulation by in situ transmission electron microscopy. The underlying mechanisms for molecular selectivity are investigated through electronic structure calculations, indicating a strong charge transfer to the heavy metal oxyanions. Finally, chromium and arsenic are remediated efficiently at concentrations as low as 100 ppb, in the presence of over 200-fold excess competing salts.

PMID:
30409968
PMCID:
PMC6224381
DOI:
10.1038/s41467-018-07159-0
[Indexed for MEDLINE]
Free PMC Article

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