RIVER WATER QUALITY STUDIES BY USING RADIOACTIVE TRACERS. A PRACTICAL CASE

M. E. Meciano1, Larosa, A. Martins de Albuquerque1, S. Nakahira1, D. de Castro Rubio Poli2

1 CETESB, 345, Prof. Frederico Hermann Junior Av., Alto de Pinheiros, CEP 05498-900, São Paulo, Brazil,
2 IPEN-CNEN, Travessa R 400, Cidade Universitaria, CEP 05508-900, São Paulo, Brazil


This work presents an analysis of the self purification behavior of the High Middle Tietê river in relation to several effluents flows of the Rasgäo Reservoir and several BOD and OD levels. The water transit time the flows measurement performed and the longitudinal dispersion coefficient are important parameters evaluated by the use of tracers technique. Between 1982 and 1984 five campaigns of transit time and water quality measuremets of the river were made. In these campaigns, a radioactive tracer produced by IPEN was injected into the river by CETESB's technicians downstream of the Rasgäo water reservoir. The works were performed in steady state conditions. The behaviour of the "radioactive cloud" was evaluated along a 266 sector of the Middle High Tietê river. Flows varied from 1.1 to 350 m3/s.