Cargando…

Photochemical Degradation of Cyanides and Thiocyanates from an Industrial Wastewater

We have explored the simultaneous degradation of cyanides and thiocyanate present in wastewaters from a cokemaking factory using photoassisted methods under varied illumination conditions (from simulated solar light to UV light). Overall, the photochemical degradation of cyanides was more efficient...

Descripción completa

Detalles Bibliográficos
Autores principales: Viña Mediavilla, Juan Jose, Fernandez Perez, Begoña, Fernandez de Cordoba, Maria C., Ayala Espina, Julia, Ania, Conchi O.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6480199/
https://www.ncbi.nlm.nih.gov/pubmed/30965653
http://dx.doi.org/10.3390/molecules24071373
_version_ 1783413521328898048
author Viña Mediavilla, Juan Jose
Fernandez Perez, Begoña
Fernandez de Cordoba, Maria C.
Ayala Espina, Julia
Ania, Conchi O.
author_facet Viña Mediavilla, Juan Jose
Fernandez Perez, Begoña
Fernandez de Cordoba, Maria C.
Ayala Espina, Julia
Ania, Conchi O.
author_sort Viña Mediavilla, Juan Jose
collection PubMed
description We have explored the simultaneous degradation of cyanides and thiocyanate present in wastewaters from a cokemaking factory using photoassisted methods under varied illumination conditions (from simulated solar light to UV light). Overall, the photochemical degradation of cyanides was more efficient than that of thiocyanates, regardless of the illumination conditions, the effect being more pronounced in the absence of a photocatalyst. This is due to their different degradation mechanism that in the case of thiocyanates is dominated by fast recombination reactions and/or charge transfer reactions to electron scavengers. In all cases, cyanate, ammonia, nitrates, and nitrites were formed at different amounts depending on the illumination conditions. The conversion yield under simulated solar light was almost complete for cyanides and quite high for thiocyanates after 6 h of illumination. Regarding toxicity, photochemical oxidation at 254 nm and under simulated solar light decreased significantly the toxicity of the pristine wastewater, showing a correlation with the intensity of the irradiation source. This indicate that simulated light can be effectively used to reduce the toxicity of industrial effluents, opening an interesting perspective for optimizing cyanide detoxification systems based on natural light.
format Online
Article
Text
id pubmed-6480199
institution National Center for Biotechnology Information
language English
publishDate 2019
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-64801992019-04-30 Photochemical Degradation of Cyanides and Thiocyanates from an Industrial Wastewater Viña Mediavilla, Juan Jose Fernandez Perez, Begoña Fernandez de Cordoba, Maria C. Ayala Espina, Julia Ania, Conchi O. Molecules Article We have explored the simultaneous degradation of cyanides and thiocyanate present in wastewaters from a cokemaking factory using photoassisted methods under varied illumination conditions (from simulated solar light to UV light). Overall, the photochemical degradation of cyanides was more efficient than that of thiocyanates, regardless of the illumination conditions, the effect being more pronounced in the absence of a photocatalyst. This is due to their different degradation mechanism that in the case of thiocyanates is dominated by fast recombination reactions and/or charge transfer reactions to electron scavengers. In all cases, cyanate, ammonia, nitrates, and nitrites were formed at different amounts depending on the illumination conditions. The conversion yield under simulated solar light was almost complete for cyanides and quite high for thiocyanates after 6 h of illumination. Regarding toxicity, photochemical oxidation at 254 nm and under simulated solar light decreased significantly the toxicity of the pristine wastewater, showing a correlation with the intensity of the irradiation source. This indicate that simulated light can be effectively used to reduce the toxicity of industrial effluents, opening an interesting perspective for optimizing cyanide detoxification systems based on natural light. MDPI 2019-04-08 /pmc/articles/PMC6480199/ /pubmed/30965653 http://dx.doi.org/10.3390/molecules24071373 Text en © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Viña Mediavilla, Juan Jose
Fernandez Perez, Begoña
Fernandez de Cordoba, Maria C.
Ayala Espina, Julia
Ania, Conchi O.
Photochemical Degradation of Cyanides and Thiocyanates from an Industrial Wastewater
title Photochemical Degradation of Cyanides and Thiocyanates from an Industrial Wastewater
title_full Photochemical Degradation of Cyanides and Thiocyanates from an Industrial Wastewater
title_fullStr Photochemical Degradation of Cyanides and Thiocyanates from an Industrial Wastewater
title_full_unstemmed Photochemical Degradation of Cyanides and Thiocyanates from an Industrial Wastewater
title_short Photochemical Degradation of Cyanides and Thiocyanates from an Industrial Wastewater
title_sort photochemical degradation of cyanides and thiocyanates from an industrial wastewater
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6480199/
https://www.ncbi.nlm.nih.gov/pubmed/30965653
http://dx.doi.org/10.3390/molecules24071373
work_keys_str_mv AT vinamediavillajuanjose photochemicaldegradationofcyanidesandthiocyanatesfromanindustrialwastewater
AT fernandezperezbegona photochemicaldegradationofcyanidesandthiocyanatesfromanindustrialwastewater
AT fernandezdecordobamariac photochemicaldegradationofcyanidesandthiocyanatesfromanindustrialwastewater
AT ayalaespinajulia photochemicaldegradationofcyanidesandthiocyanatesfromanindustrialwastewater
AT aniaconchio photochemicaldegradationofcyanidesandthiocyanatesfromanindustrialwastewater