Abstract

The water scarcity in the Northern of Chile is a critical issue that is increasing the needs to obtain new water resources or reuse of the actual resources. In the mining industry water could be cleaned for reuse in the same or other applications. Another alternative is the use of seawater directly or after desalination. However, seawater would be pretreated before the process of Reverse Osmosis to eliminate algae and other impurities; e.g., some algae bloom like “red tide” events. This could be carried out by the Dissolved air flotation (DAF). DAF uses air saturated water at high pressure to generate microbubbles, which are created when the water is released into the flotation tank that is maintained at atmospheric pressure, these microbubbles capture contaminant particles when they rise to the surface of the flotation cell where they are removed by skimming. DAF has the advantage of removing suspended organic matter and oils that cannot be removed by sand filtration and can treat waters with mineral turbidity up to 50 NTU and non-mineral turbidity up to 200 NTU. Several studies have determined that over 99% removal of harmful algal blooms can be achieved through seawater pretreatment. A DAF system had been constructed to carry out experiments using green algae, Tetraselmis sp., which can be found during “green tide” events. At the same time a CFD model was applied using the experimental variables with approximated values. Once validated, this will be used to improve the operational conditions of the system and the flotation cell design of similar reactors working at other scales, conditions, or configurations.