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Published on: December 19, 2017
Photochemical source of metals for sediments
Jirí Kopácek1, Marie Maresová, Stephen A Norton
1Hydrobiological Institute Academy of Sciences, Ceské Budejovice 37005, Czech Republic. jkopacek@hbu.cas.cz
Environmental Science & Technology
|August 15, 2006
Summary
Photochemical reactions release aluminum (Al) and iron (Fe) from soil organic matter into lakes, forming oxyhydroxides that settle into sediments. This natural process significantly impacts lake ecosystems and metal transport.
Area of Science:
- Environmental Chemistry
- Geochemistry
- Limnology
Background:
- Organic acids in soils bind aluminum (Al) and iron (Fe), transporting them to aquatic systems.
- Understanding Al and Fe fluxes in lakes is crucial for ecosystem health.
Purpose of the Study:
- To investigate the role of photochemistry in Al and Fe cycling in Plesné Lake.
- To quantify the contribution of photochemical liberation to sedimentary fluxes of Al and Fe.
Main Methods:
- Mass budget analysis of in-lake Al fluxes.
- Palaeolimnological analysis of a >10,000-year sediment record.
- In situ photochemical experiments.
Main Results:
- Photochemical liberation of organically bound Al and Fe by solar radiation is a significant source of ionic species in lakes.
- Photochemically induced transformation to oxyhydroxides dominated Al and Fe sedimentary flux (91% and 73%) in Plesné Lake's preindustrial era.
- Approximately 50% of organically bound Al and Fe were liberated as inorganic ions via photochemical decomposition.
Conclusions:
- Photochemical processes are a key natural source of Al and Fe for lakes, influencing their sedimentary deposition.
- This Al and Fe transport mechanism likely occurs in other aquatic environments, impacting trace metal and phosphorus binding.
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