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Hexavalent chromium in drinking water: Chemistry, challenges and future outlook on Sn(II)- and photocatalyst-based treatment

Chromium (Cr) typically exists in either trivalent and hexavalent oxidation states in drinking water, i.e., Cr(III) and Cr(VI), with Cr(VI) of particular concern in recent years due to its high toxicity and new regulatory standards. This Account presented a critical analysis of the sources and occur...

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Autores principales: Liu, Haizhou, Yu, Xuejun
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Higher Education Press 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7439242/
https://www.ncbi.nlm.nih.gov/pubmed/32839673
http://dx.doi.org/10.1007/s11783-020-1267-4
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author Liu, Haizhou
Yu, Xuejun
author_facet Liu, Haizhou
Yu, Xuejun
author_sort Liu, Haizhou
collection PubMed
description Chromium (Cr) typically exists in either trivalent and hexavalent oxidation states in drinking water, i.e., Cr(III) and Cr(VI), with Cr(VI) of particular concern in recent years due to its high toxicity and new regulatory standards. This Account presented a critical analysis of the sources and occurrence of Cr(VI) in drinking water in the United States, analyzed the equilibrium chemistry of Cr(VI) species, summarized important redox reaction relevant to the fate of Cr(VI) in drinking water, and critically reviewed emerging Cr(VI) treatment technologies. There is a wide occurrence of Cr(VI) in US source drinking water, with a strong dependence on groundwater sources, mainly due to naturally weathering of chromium-containing aquifers. Challenges regarding traditional Cr(VI) treatment include chemical cost, generation of secondary waste and inadvertent re-generation of Cr(VI) after treatment. To overcome these challenges, reductive Cr(VI) treatment technologies based on the application of stannous tin or electron-releasing titanium dioxide photocatalyst hold extreme promise in the future. To moving forward in the right direction, three key questions need further exploration for the technology implementation, including effective management of residual waste, minimizing the risks of Cr(VI) re-occurrence downstream of drinking water treatment plant, and promote the socioeconomic drivers for Cr(VI) control in the future. [Image: see text]
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spelling pubmed-74392422020-08-20 Hexavalent chromium in drinking water: Chemistry, challenges and future outlook on Sn(II)- and photocatalyst-based treatment Liu, Haizhou Yu, Xuejun Front Environ Sci Eng Review Article Chromium (Cr) typically exists in either trivalent and hexavalent oxidation states in drinking water, i.e., Cr(III) and Cr(VI), with Cr(VI) of particular concern in recent years due to its high toxicity and new regulatory standards. This Account presented a critical analysis of the sources and occurrence of Cr(VI) in drinking water in the United States, analyzed the equilibrium chemistry of Cr(VI) species, summarized important redox reaction relevant to the fate of Cr(VI) in drinking water, and critically reviewed emerging Cr(VI) treatment technologies. There is a wide occurrence of Cr(VI) in US source drinking water, with a strong dependence on groundwater sources, mainly due to naturally weathering of chromium-containing aquifers. Challenges regarding traditional Cr(VI) treatment include chemical cost, generation of secondary waste and inadvertent re-generation of Cr(VI) after treatment. To overcome these challenges, reductive Cr(VI) treatment technologies based on the application of stannous tin or electron-releasing titanium dioxide photocatalyst hold extreme promise in the future. To moving forward in the right direction, three key questions need further exploration for the technology implementation, including effective management of residual waste, minimizing the risks of Cr(VI) re-occurrence downstream of drinking water treatment plant, and promote the socioeconomic drivers for Cr(VI) control in the future. [Image: see text] Higher Education Press 2020-08-10 2020 /pmc/articles/PMC7439242/ /pubmed/32839673 http://dx.doi.org/10.1007/s11783-020-1267-4 Text en © Higher Education Press 2020 This article is made available via the PMC Open Access Subset for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.
spellingShingle Review Article
Liu, Haizhou
Yu, Xuejun
Hexavalent chromium in drinking water: Chemistry, challenges and future outlook on Sn(II)- and photocatalyst-based treatment
title Hexavalent chromium in drinking water: Chemistry, challenges and future outlook on Sn(II)- and photocatalyst-based treatment
title_full Hexavalent chromium in drinking water: Chemistry, challenges and future outlook on Sn(II)- and photocatalyst-based treatment
title_fullStr Hexavalent chromium in drinking water: Chemistry, challenges and future outlook on Sn(II)- and photocatalyst-based treatment
title_full_unstemmed Hexavalent chromium in drinking water: Chemistry, challenges and future outlook on Sn(II)- and photocatalyst-based treatment
title_short Hexavalent chromium in drinking water: Chemistry, challenges and future outlook on Sn(II)- and photocatalyst-based treatment
title_sort hexavalent chromium in drinking water: chemistry, challenges and future outlook on sn(ii)- and photocatalyst-based treatment
topic Review Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7439242/
https://www.ncbi.nlm.nih.gov/pubmed/32839673
http://dx.doi.org/10.1007/s11783-020-1267-4
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