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The Seasonality of Nitrite Concentrations in a Chloraminated Drinking Water Distribution System

We studied the seasonal variation of nitrite exposure in a drinking water distribution system (DWDS) with monochloramine disinfection in the Helsinki Metropolitan Area. In Finland, tap water is the main source of drinking water, and thus the nitrite in tap water increases nitrite exposure. Our data...

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Autores principales: Rantanen, Pirjo-Liisa, Mellin, Ilkka, Keinänen-Toivola, Minna M., Ahonen, Merja, Vahala, Riku
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6121643/
https://www.ncbi.nlm.nih.gov/pubmed/30111761
http://dx.doi.org/10.3390/ijerph15081756
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author Rantanen, Pirjo-Liisa
Mellin, Ilkka
Keinänen-Toivola, Minna M.
Ahonen, Merja
Vahala, Riku
author_facet Rantanen, Pirjo-Liisa
Mellin, Ilkka
Keinänen-Toivola, Minna M.
Ahonen, Merja
Vahala, Riku
author_sort Rantanen, Pirjo-Liisa
collection PubMed
description We studied the seasonal variation of nitrite exposure in a drinking water distribution system (DWDS) with monochloramine disinfection in the Helsinki Metropolitan Area. In Finland, tap water is the main source of drinking water, and thus the nitrite in tap water increases nitrite exposure. Our data included both the obligatory monitoring and a sampling campaign data from a sampling campaign. Seasonality was evaluated by comparing a nitrite time series to temperature and by calculating the seasonal indices of the nitrite time series. The main drivers of nitrite seasonality were the temperature and the water age. We observed that with low water ages (median: 6.7 h) the highest nitrite exposure occurred during the summer months, and with higher water ages (median: 31 h) during the winter months. With the highest water age (190 h), nitrite concentrations were the lowest. At a low temperature, the high nitrite concentrations in the winter were caused by the decelerated ammonium oxidation. The dominant reaction at low water ages was ammonium oxidation into nitrite and, at high water ages, it was nitrite oxidation into nitrate. These results help to direct monitoring appropriately to gain exact knowledge of nitrite exposure. Also, possible future process changes and additional disinfection measures can be designed appropriately to minimize extra nitrite exposure.
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spelling pubmed-61216432018-09-07 The Seasonality of Nitrite Concentrations in a Chloraminated Drinking Water Distribution System Rantanen, Pirjo-Liisa Mellin, Ilkka Keinänen-Toivola, Minna M. Ahonen, Merja Vahala, Riku Int J Environ Res Public Health Article We studied the seasonal variation of nitrite exposure in a drinking water distribution system (DWDS) with monochloramine disinfection in the Helsinki Metropolitan Area. In Finland, tap water is the main source of drinking water, and thus the nitrite in tap water increases nitrite exposure. Our data included both the obligatory monitoring and a sampling campaign data from a sampling campaign. Seasonality was evaluated by comparing a nitrite time series to temperature and by calculating the seasonal indices of the nitrite time series. The main drivers of nitrite seasonality were the temperature and the water age. We observed that with low water ages (median: 6.7 h) the highest nitrite exposure occurred during the summer months, and with higher water ages (median: 31 h) during the winter months. With the highest water age (190 h), nitrite concentrations were the lowest. At a low temperature, the high nitrite concentrations in the winter were caused by the decelerated ammonium oxidation. The dominant reaction at low water ages was ammonium oxidation into nitrite and, at high water ages, it was nitrite oxidation into nitrate. These results help to direct monitoring appropriately to gain exact knowledge of nitrite exposure. Also, possible future process changes and additional disinfection measures can be designed appropriately to minimize extra nitrite exposure. MDPI 2018-08-15 2018-08 /pmc/articles/PMC6121643/ /pubmed/30111761 http://dx.doi.org/10.3390/ijerph15081756 Text en © 2018 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
Rantanen, Pirjo-Liisa
Mellin, Ilkka
Keinänen-Toivola, Minna M.
Ahonen, Merja
Vahala, Riku
The Seasonality of Nitrite Concentrations in a Chloraminated Drinking Water Distribution System
title The Seasonality of Nitrite Concentrations in a Chloraminated Drinking Water Distribution System
title_full The Seasonality of Nitrite Concentrations in a Chloraminated Drinking Water Distribution System
title_fullStr The Seasonality of Nitrite Concentrations in a Chloraminated Drinking Water Distribution System
title_full_unstemmed The Seasonality of Nitrite Concentrations in a Chloraminated Drinking Water Distribution System
title_short The Seasonality of Nitrite Concentrations in a Chloraminated Drinking Water Distribution System
title_sort seasonality of nitrite concentrations in a chloraminated drinking water distribution system
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6121643/
https://www.ncbi.nlm.nih.gov/pubmed/30111761
http://dx.doi.org/10.3390/ijerph15081756
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