Determinação experimental do coeficiente de reaeração em rios, com o uso de traçador gasoso inerte

Abstract

ln this work, the reaeration coefficient, K2, in rivers is experimentally determined using the so-called Modified Tracer Technique. In this technique an inert hydrocarbon gas tracer, the propane, is used to simulate oxygen, and a fluorescent tracer, Amidorhodamine G Extra, as a reference tracer. The technique has been apllied in rivers with low flow rates, replacing the metodology developed by Tsivoglou, that uses a radioactive gas tracer, the Kr-85. ln this work the possibility of extrapolating the technique to rivers with high flow rates is studied. The experiments were performed on a 40 Km long reach of the Paraíba do Sul river, between Volta Redonda and Barra do Piraí cities. It is presented the theoretical basis of the modified tracer technique, the procedures employed during the field and laboratory experiments, and the devices which were used in both laboratory and field work. Measured values of K2 are compared with computed values obtained from predictive equations.