R. G. Passos1*, D. F. C. Dias1, M. P. Matos1, T. E. Possmoser-Nascimento2, M. V. Sperling1
1Department of Sanitary and Environmental Engineering, Federal University of Minas Gerais, Av. Antônio Carlos 6627 – Escola de Engenharia, Bloco 1 – sala 4622; 31270–901 – Belo Horizonte, Brazil 2UNESC – Integrated College of Cacoal, R. dos Esportes, 1030, B. Incra; 76965-864 – Cacoal, Brazil(free)
Results of tests with saline tracers (sodium chloride) in two shallow maturation ponds treating anaerobic effluent in Brazil are presented. One of the ponds had no baffles and presented accumulated sludge after 12 years of operation, while the other had two longitudinal baffles, a shallower depth and the sludge had been previously removed. From the tests, a general tendency to complete mixing with high dispersion was observed in both ponds, even the baffled one. The values of the dispersion number d suggest a high dispersion in both ponds. Daily cycles of stratification and destratification could be seen from the tracer curves. The main results of this study and authors’ perceptions regarding the tests allowed practical considerations about the use of saline tracers in pond systems.