ISSN:
1440-1770
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Geography
Notes:
In the summer of 1995, samples of suspended solids and bottom sediments were collected from the lower course of the Danube, downstream from potential pollution sources such as tributaries draining industrialised and densely populated watersheds (the Jiu, Olt, Arges and Ialomita rivers) or big cities on the border of the river (Tulcea, Galati, Braila), and from the Danube Delta. Chemical and toxicological analyses were carried out on these samples. In the present paper, the results of the measurements of the forms of particulate phosphorus are discussed. Phosphorus occurring in the bottom sediments and the suspended solids has various origins and chemical forms. These forms may be operationally defined as: organic phosphorus (OP), apatite inorganic phosphorus (AP) and non-apatite inorganic phosphorus (NAIP). The AP shows low variability, ranging from 350 to 400 p.p.m. for suspended solids and from 425 to 500 p.p.m. for bottom sediments. This is essentially due to the detrital origin of this form. These values are typical for freshwater sediments in European rivers. The NAIP, which originates both from natural sources and from human pollution, shows a high variability. This indicates that the nutrient pollution is derived from both point and non-point sources in the watershed. The NAIP concentrations of 800 p.p.m. (Vadul Oii) and 850 p.p.m. (Oltenita) are very high (fourfold the average for European rivers), indicating that strong anthropogenic sources of phosphorus are present in the lower Danube watershed. As the NAIP is potentially bioavailable, its high concentration may contribute to eutrophication in the lower Danube and the Danube Delta.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1440-1770.2000.00104.x
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