『Abstract
Urban canal sediment provides an opportunity to investigate the
processes controlling P geochemistry in a system dominated by
anthropogenic input. To achieve this a combined study was undertaken
of pore water geochemistry and petrology of the top 25 cm canal
bed sediment from two urban canals in the English West Midland
conurbation. Processes in the sediment are dominated by the geochemistry
of Fe, P and organic matter. Results indicate that sediment re-suspension
by boat traffic has a major influence on pore water chemistry.
In addition to the sediment water interface an additional interface
at 6-7 cm depth was identified and corresponds to the maximum
depth of sediment re-suspension by boat traffic. Phosphorus in
the sediment occurs predominantly as vivianite. Low PO4
concentrations occur close to the sediment water interface in
summer due to frequent re-suspension and Fe oxidation. High PO4 concentrations occur close to the sediment water
interface in winter when boat traffic is infrequent. The greatest
potential to exchange phosphate between sediment and water column
will therefore occur during infrequent boat traffic regimes.』
1. Introduction
2. Methods
3. Results
3.1. pH, Eh and alkalinity
3.2. Pore water iron
3.3. Pore water phosphate
3.4. Pore water sulphate
3.5. Petrology
4. Discussion
5. Conclusions
Acknowledgements
References