Sulphate reduction in the sediment of the Venice canals (Italy)
In: Marine Pollution Bulletin. Macmillan: London. ISSN 0025-326X; e-ISSN 1879-3363, more
Also appears in:Zonta, R.; Guerzoni, S.; De Jonge, V.N.; Pérez-Ruzafa, A. (Ed.) (2007). Measuring and managing changes in estuaries and lagoons. Marine Pollution Bulletin, 55(Spec. Issue 10-12). Elsevier: Amsterdam. 403-602 pp., more
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| Keywords |
Chemical reactions > Reduction > Sulphate reduction
MED, Italy, Veneto, Venice Lagoon [Marine Regions]
Marine/Coastal |
| Authors | | Top |
- Zaggia, L.
- Rosso, J.
- Zonta, R.
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| Abstract |
The sulphur cycle in the sediment of the Venice canal network was investigated by considering the sulphate reduction rate (SRR) and the distribution of sulphur compounds, in both pore water and sediment. Sulphate reduction (SR) is the main process in the metabolism of the organic matter supplied to the network by untreated urban effluents. Although it might account for the decomposition of only a limited percentage of the total organic-C inputs, the estimated rates are among the highest observed in coastal sediments. Measured rates range from 0.26 to 0.99 µmol cm-3 d-1, while mean annual values, estimated by a diagenetic model, vary from 0.16 to 0.43 µmol cm-3 d-1. The speciation of S in the sediment reveals that pyrite-S is the most abundant component of the total reduced S pool, whereas acid volatile sulphides and elemental sulphur together account for less than 45%. A preliminary budget indicates that the rate of burial of solid-phase S is small compared to the S produced by SR (from 10 to 25%). A large amount of reduced S is then lost from the canal deposits to be re-oxidised at the sediment-water interface or in the overlying water column. |
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