Effect of hydraulic conditions on manganese accumulation by physical and chemical pathways in chlorinated water distribution system: A preliminary laboratory study
The accumulation of manganese (Mn) in drinking water distribution systems (DWDS) is the main reason for ‘black water’ occurrences at customers' taps. Here, we focused on the impact of hydraulic conditions on Mn accumulation in well chlorinated DWDS, particularly on the physical pathway (i.e., t...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IWA Publishing
2022-10-01
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| Series: | Water Supply |
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| Online Access: | http://ws.iwaponline.com/content/22/10/7576 |
| _version_ | 1811332300116328448 |
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| author | Xinyi Zhou Tomohiro Nakanishi Shinya Echigo Koji Kosaka Sadahiko Itoh |
| author_facet | Xinyi Zhou Tomohiro Nakanishi Shinya Echigo Koji Kosaka Sadahiko Itoh |
| author_sort | Xinyi Zhou |
| collection | DOAJ |
| description | The accumulation of manganese (Mn) in drinking water distribution systems (DWDS) is the main reason for ‘black water’ occurrences at customers' taps. Here, we focused on the impact of hydraulic conditions on Mn accumulation in well chlorinated DWDS, particularly on the physical pathway (i.e., the attachment of particulate Mn to the inner pipe surface) and the chemical pathway (i.e., the autocatalytic oxidation of Mn2+ on the surface of accumulated Mn). Mn accumulation on epoxy resin, a typical lining material for distribution pipes in Japan, was observed in laboratory-scale experiments under different water velocity conditions. The results showed that Mn accumulation was significantly enhanced under higher velocity conditions, which was then fitted with the numerical models describing Mn accumulation by the physical and chemical pathways and the detachment. The rate constants for the physical and chemical pathways had a positive relationship with the flow turbulence in the investigated range, suggesting that hydraulic conditions in DWDS play an important role in Mn accumulation. Effects of Mn speciation and water characteristics on the accumulation process were also simulated under various hydraulic conditions. Based on the obtained results, appropriate countermeasures to control manganese accumulation were then discussed.
HIGHLIGHTS
Effect of hydraulic condition on Mn accumulation in distribution pipes was studied.;
Mn accumulated in pipes via the physical and chemical pathways in chlorinated condition.;
The contribution of the chemical pathway of Mn accumulation increased with time.;
The rates of both pathways were greatly affected by water velocity.;
Increasing the water velocity alone may not be sufficient to reduce Mn accumulation.; |
| first_indexed | 2024-04-13T16:34:44Z |
| format | Article |
| id | doaj.art-eb46410812b243a68d54f198e873a62e |
| institution | Directory Open Access Journal |
| issn | 1606-9749 1607-0798 |
| language | English |
| last_indexed | 2024-04-13T16:34:44Z |
| publishDate | 2022-10-01 |
| publisher | IWA Publishing |
| record_format | Article |
| series | Water Supply |
| spelling | doaj.art-eb46410812b243a68d54f198e873a62e2022-12-22T02:39:28ZengIWA PublishingWater Supply1606-97491607-07982022-10-0122107576758910.2166/ws.2022.338338Effect of hydraulic conditions on manganese accumulation by physical and chemical pathways in chlorinated water distribution system: A preliminary laboratory studyXinyi Zhou0Tomohiro Nakanishi1Shinya Echigo2Koji Kosaka3Sadahiko Itoh4 Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Kyoto University Katsura, Nishikyo, Kyoto 615-8540, Japan Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Kyoto University Katsura, Nishikyo, Kyoto 615-8540, Japan Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Kyoto University Katsura, Nishikyo, Kyoto 615-8540, Japan Department of Environmental Health, National Institute of Public Health, 2-3-6 Minami, Wako, Saitama 351-0197, Japan Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Kyoto University Katsura, Nishikyo, Kyoto 615-8540, Japan The accumulation of manganese (Mn) in drinking water distribution systems (DWDS) is the main reason for ‘black water’ occurrences at customers' taps. Here, we focused on the impact of hydraulic conditions on Mn accumulation in well chlorinated DWDS, particularly on the physical pathway (i.e., the attachment of particulate Mn to the inner pipe surface) and the chemical pathway (i.e., the autocatalytic oxidation of Mn2+ on the surface of accumulated Mn). Mn accumulation on epoxy resin, a typical lining material for distribution pipes in Japan, was observed in laboratory-scale experiments under different water velocity conditions. The results showed that Mn accumulation was significantly enhanced under higher velocity conditions, which was then fitted with the numerical models describing Mn accumulation by the physical and chemical pathways and the detachment. The rate constants for the physical and chemical pathways had a positive relationship with the flow turbulence in the investigated range, suggesting that hydraulic conditions in DWDS play an important role in Mn accumulation. Effects of Mn speciation and water characteristics on the accumulation process were also simulated under various hydraulic conditions. Based on the obtained results, appropriate countermeasures to control manganese accumulation were then discussed. HIGHLIGHTS Effect of hydraulic condition on Mn accumulation in distribution pipes was studied.; Mn accumulated in pipes via the physical and chemical pathways in chlorinated condition.; The contribution of the chemical pathway of Mn accumulation increased with time.; The rates of both pathways were greatly affected by water velocity.; Increasing the water velocity alone may not be sufficient to reduce Mn accumulation.;http://ws.iwaponline.com/content/22/10/7576chemical oxidationdrinking water distribution systemhydraulic conditionmanganese accumulationnumerical simulationphysical attachment |
| spellingShingle | Xinyi Zhou Tomohiro Nakanishi Shinya Echigo Koji Kosaka Sadahiko Itoh Effect of hydraulic conditions on manganese accumulation by physical and chemical pathways in chlorinated water distribution system: A preliminary laboratory study Water Supply chemical oxidation drinking water distribution system hydraulic condition manganese accumulation numerical simulation physical attachment |
| title | Effect of hydraulic conditions on manganese accumulation by physical and chemical pathways in chlorinated water distribution system: A preliminary laboratory study |
| title_full | Effect of hydraulic conditions on manganese accumulation by physical and chemical pathways in chlorinated water distribution system: A preliminary laboratory study |
| title_fullStr | Effect of hydraulic conditions on manganese accumulation by physical and chemical pathways in chlorinated water distribution system: A preliminary laboratory study |
| title_full_unstemmed | Effect of hydraulic conditions on manganese accumulation by physical and chemical pathways in chlorinated water distribution system: A preliminary laboratory study |
| title_short | Effect of hydraulic conditions on manganese accumulation by physical and chemical pathways in chlorinated water distribution system: A preliminary laboratory study |
| title_sort | effect of hydraulic conditions on manganese accumulation by physical and chemical pathways in chlorinated water distribution system a preliminary laboratory study |
| topic | chemical oxidation drinking water distribution system hydraulic condition manganese accumulation numerical simulation physical attachment |
| url | http://ws.iwaponline.com/content/22/10/7576 |
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