The influence of porous media aggregation on the nitrate and ammonium transport in soil columns

Authors: Vesna ZUPANC, Miran VESELIČ, Peter CEPUDER
Citation: Acta hydrotechnica, vol. 19, no. 31, pp. 117-135, 2001.
Abstract: The displacement of one fluid by another miscible fluid under saturated conditions and at different average flow velocities in one – dimensional soil columns was studied. For the tracer solute, nitrogen fertilizer (combination of ammonium (NH4+) and nitrate (NO3-) form of nitrogen) was used to observe the behavior of the nitrogen in the transport processes. For the displacing fluid, distilled water was used. In the course of the experiments, conditions in soil columns with < 2 mm soil fraction were altered. The size of the chosen aggregates influenced the behavior of the tracer. Breakthrough curves of NO3- were compared to the NH4+ breakthrough curves symmetrical with all aggregate sizes. The BTC of the NH4+ obtained a clear shape with the larger aggregate sizes 0.63– 2 mm and 2–4 mm. The greatest influence on the NH4+ transport had the ability of the NH4+ to fixate on the negatively charged particle surfaces.
Keywords: column experiments, porous media, aggregate size, nitrate, ammonium
Full text: a31-vz.pdf