The evaluation of existing units as a start point for optimization of water treatment plant enlargement: A real case

Abstract

Filtration units for potabilization of surface water should be designed with special attention in three parameters: filtration rate, thickness of the filtration bed and size of the granular media. The size of the filtration plant, and therefore the cost of construction , is basically determined by the first two parameters listed above. Depending on the water quality, the filtration rate could be between 10 to 20 m3/m2/h, and the determination of this parameter is essential for a proper design of large plants. Nowadays, any rational design of filtration units should be based on the results of a pilot plant as a way to determine the design parameters. An inadequate selection would lead to serious problems in filter operation or to an unnecessary expensive plant. The cost of a pilot plant is always lower than the higher cost that would bring a selection of a very low rate. This paper shows how to determine the design rate,thickness of the bed filter and type of the granular media for a declining rate filtration unit to be constructed at the the Aguas Corrientes treatment plant. This new plant will increase in 10.000 m3/h the filtration capacity of the Aguas Corrientes treatment plant, which supplies the city of Montevideo with potable water.