Distribution of nutrients in fluvial sediment of the Itajai-Açu river, Blumenau, SC, Brazil

Abstract

This study verified the occurrence of nitrogen (Ntotal, NH4+, NO3- e NO2-) and phosphorus (Ptotal) in fluvial sediments of the Itajaí-Açu River, on the river's course in the urban area of Blumenau city. At the eight sites where the samples were collected, the total nitrogen presented values below those recommended in the CONAMA nº 344/2004 Resolution for sediments which is 4,800.00 µg g-1, with values of 350.00 µg g-1 to 2,100.00 µg g-1. The total phosphorus also presented values below the one recommended by the CONAMA nº 344/2004 Resolution for sediments which is 2,000.00 µg g-1. The values found for total phosphorus varied from 61.50 µg g-1 to 378.00 µg g-1, and were determined as the addition of the organic and the inorganic phosphorus. As for the summation of the NH4+, NO3- and NO2- ions at the eight sites where the sample were collected, it can be observed a greater quantity of these ions in any collecting site and in the other sites the values were low. The content values for the NO2- ions for the studied eight sites were low when compared to the values observed for the NH4+ ion.