Study of the internal hydrodynamics in three facultative ponds of two municipal WSPS in Spain

The hydraulic performances of three facultative ponds, two of the Cieza and one of the Lorqui-Ceuti joint municipal wastewater stabilization ponds sys tems, were studied. The ponds of Cieza have a maximum capacity of 16,500 m( 3) (F.1) and 32,000 m(3) (F.2), and both have a maximum depth of 1.6 m. The pond of Lorqui-Ceuti have a maximum capacity of 27,000 m(3) and a maximum depth of 1.8 m. A dye tracer, sulforhodamine B, was injected with the feed flow of each one facultative ponds. In the course of time, samples from wit hin and at the outlet of every system were taken. The data obtained prove t hat the hydrodynamic behavior of the ponds is similar to a perfectly mixed tank reactor. The average real residence times were also determined. When t hese were compared to ponds, considered ideal perfectly mixed tank reactors , a high level of coincidence was noted. It was also observed that the hydr odynamics of the ponds presented virtually no flow anomalies. (C) 1999 Else vier Science Ltd. All rights reserved.