EXPERIMENTAL TESTS USING RHODAMINE WT AS TRACER

Tracer tests with fluorescent dyes have been commonly used to describe physical mechanisms and consequently to determine hydrodispersive parameters. The actual behaviour of these dyes is one of the central issues in the evaluation of tracer tests. In this paper we describe an experimental set-up designed to investigate the behaviour of Rhodamine Wt. A batch experiment was conducted using a standardized technique and equilibrium isotherms were interpolated. The column experiment was conducted using a cylindrical permeameter with the aim of minimizing dead volume and outlining only the sorption of the porous media. Inside the permeameter a constant-rate injection of a solution with both NaCl and Rhodamine Wt was performed and breakthrough curves have been obtained. The tests reveal a mild nonlinear sorption behaviour of Rhodamine Wt. The experimental tests have also pointed out the feasibility of the mathematical model used to calibrate the experimental data.