Dissolved boron and nutrients in the mixing plumes of major tropical rivers
Fanning, K.A.; Maynard, V.I. (1978). Dissolved boron and nutrients in the mixing plumes of major tropical rivers. Neth. J. Sea Res. 12(3-4): 345-354
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579; e-ISSN 1873-1406, more
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| Authors | | Top |
- Fanning, K.A.
- Maynard, V.I.
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| Abstract |
Water samples from the plumes of the Zaire River in Africa and the Magdalena River in South America were analyzed for dissolved boron in order to search for interactions between boron and suspended sediments. These interactions have been reported only for smaller rivers. To help characterize any sediment-water interactions, dissolved nutrients were measured as well. On a single graph, boron concentrations were plotted against corresponding salinities for samples from both river plumes. The data points fell on a straight line, and, when multiplied by the salinity- chlorinity ratio of sea water (1.80655), the slope of that line gave the accepted boron-chlorinity ratio of sea water 0.231 mg. kg-1 (‰ chlor.)-1. The excellent fit of all the boron-salinity data to a single straight line with that particular slope indicated that boron acted conservatively in both plumes. Serious doubt is therefore cast on the idea that inorganic adsorption of boron onto suspended sediment is a significant geochemical process at the freshwater-seawater interface of the ocean. Silica was completely conservative in the Magdalena plume and nearly so in the plume of the Zaïre, according to VAN BENNEKOM, BERGER, HELDER & DE VRIES (1978). Such behaviour for silica also indicates a lack of major sediment-water interactions, though minor or trace elements may be effected. Few chemical processes affected nitrate in the Magdalena plume, but the large scatter in the Magdalena phosphate distribution indicated important biological reactions, additional phosphate sources, or both. |
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