pH modelling in aquatic systems with time-variable acid-base dissociation constants applied to the turbid, tidal Scheldt estuary
A new pH modelling approach is presented that explicitly quantifies the influence of biogeochemical processes on proton cycling and pH in an aquatic ecosystem, and which accounts for time variable acid-base dissociation constants. As a case study, the method is applied to investigate proton cycling...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2009-08-01
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| Series: | Biogeosciences |
| Online Access: | http://www.biogeosciences.net/6/1539/2009/bg-6-1539-2009.pdf |
| _version_ | 1819180619684380672 |
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| author | A. F. Hofmann J. J. Middelburg K. Soetaert F. J. R. Meysman |
| author_facet | A. F. Hofmann J. J. Middelburg K. Soetaert F. J. R. Meysman |
| author_sort | A. F. Hofmann |
| collection | DOAJ |
| description | A new pH modelling approach is presented that explicitly quantifies the influence of biogeochemical processes on proton cycling and pH in an aquatic ecosystem, and which accounts for time variable acid-base dissociation constants. As a case study, the method is applied to investigate proton cycling and long-term pH trends in the Scheldt estuary (SW Netherlands, N Belgium). This analysis identifies the dominant biogeochemical processes involved in proton cycling in this heterotrophic, turbid estuary. Furthermore, information on the factors controlling the longitudinal pH profile along the estuary as well as long-term pH changes are obtained. Proton production by nitrification is identified as the principal biological process governing the pH. Its acidifying effect is mainly counteracted by proton consumption due to CO<sub>2</sub> degassing. Overall, CO<sub>2</sub> degassing generates the largest proton turnover in the whole estuary on a yearly basis. The main driver of long-term changes in the mean estuarine pH over the period 2001 to 2004 is the decreasing freshwater flow, which influences the pH directly via a decreasing supply of dissolved inorganic carbon and alkalinity, and also indirectly, via decreasing ammonia loadings and lower nitrification rates. |
| first_indexed | 2024-12-22T22:17:13Z |
| format | Article |
| id | doaj.art-8c3f52ed6c5e4b3b90076867d5a45fbf |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-12-22T22:17:13Z |
| publishDate | 2009-08-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-8c3f52ed6c5e4b3b90076867d5a45fbf2022-12-21T18:10:46ZengCopernicus PublicationsBiogeosciences1726-41701726-41892009-08-016815391561pH modelling in aquatic systems with time-variable acid-base dissociation constants applied to the turbid, tidal Scheldt estuaryA. F. HofmannJ. J. MiddelburgK. SoetaertF. J. R. MeysmanA new pH modelling approach is presented that explicitly quantifies the influence of biogeochemical processes on proton cycling and pH in an aquatic ecosystem, and which accounts for time variable acid-base dissociation constants. As a case study, the method is applied to investigate proton cycling and long-term pH trends in the Scheldt estuary (SW Netherlands, N Belgium). This analysis identifies the dominant biogeochemical processes involved in proton cycling in this heterotrophic, turbid estuary. Furthermore, information on the factors controlling the longitudinal pH profile along the estuary as well as long-term pH changes are obtained. Proton production by nitrification is identified as the principal biological process governing the pH. Its acidifying effect is mainly counteracted by proton consumption due to CO<sub>2</sub> degassing. Overall, CO<sub>2</sub> degassing generates the largest proton turnover in the whole estuary on a yearly basis. The main driver of long-term changes in the mean estuarine pH over the period 2001 to 2004 is the decreasing freshwater flow, which influences the pH directly via a decreasing supply of dissolved inorganic carbon and alkalinity, and also indirectly, via decreasing ammonia loadings and lower nitrification rates.http://www.biogeosciences.net/6/1539/2009/bg-6-1539-2009.pdf |
| spellingShingle | A. F. Hofmann J. J. Middelburg K. Soetaert F. J. R. Meysman pH modelling in aquatic systems with time-variable acid-base dissociation constants applied to the turbid, tidal Scheldt estuary Biogeosciences |
| title | pH modelling in aquatic systems with time-variable acid-base dissociation constants applied to the turbid, tidal Scheldt estuary |
| title_full | pH modelling in aquatic systems with time-variable acid-base dissociation constants applied to the turbid, tidal Scheldt estuary |
| title_fullStr | pH modelling in aquatic systems with time-variable acid-base dissociation constants applied to the turbid, tidal Scheldt estuary |
| title_full_unstemmed | pH modelling in aquatic systems with time-variable acid-base dissociation constants applied to the turbid, tidal Scheldt estuary |
| title_short | pH modelling in aquatic systems with time-variable acid-base dissociation constants applied to the turbid, tidal Scheldt estuary |
| title_sort | ph modelling in aquatic systems with time variable acid base dissociation constants applied to the turbid tidal scheldt estuary |
| url | http://www.biogeosciences.net/6/1539/2009/bg-6-1539-2009.pdf |
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