Modelling baffles in water acquaculture ponds.

The note presents the results obtained by a scale model testing the flux in one of the four phytotreatment ponds, collecting water coming from an intensive fish farm, located in the Orbetello area, before flowing the water into the Orbetello lagoon (Grosseto, Italy) with the aim of increasing water quality. Flow visualization is carried out on the scale reduced pond tested under different conditions: different flow rates, presence of baffles of different length and position. Baffles seem to improve the system efficiency, reducing recirculation areas which are not involved in the water movement within the pond and dead zones not involved in the movement. They are able to characterize the influence of the forced paths given by the baffles on the reduction of the recirculating areas and the lengthening of the residence time.