A Simplified Empirical Model for the One-stage Direct Filtration

A new configuration of the one stage direct filtration process has been investigated by Prof. Fadel (correspondent author) and his team in Mansoura University, Egypt. In this configuration, deep media with fine gravel particles (size 2-4 mm) has been used under low filtration rate (5-8 m/m/hr). For this system a simplified empirical model is proposed to describe the one stage of direct filtration process under steady-state conditions. The model is obtained based on curve fitting of true field data, which is obtained from several plants employing direct filtration process. The model considers all the essential concepts that describe the two processes of flocculation and filtration in one tank and the competition between them for limiting depth. Further, the model has considered all the major factors, which affect on the filtration process such as filter depth, filtration rate, run length, run time, size of media, and alum dose. The present model has an explicit solution, which may be useful for many applications of such filters. The application of the model has been explained for a given set of data and verified by comparison with another filed scale data. Also using the present model, the optimum operation conditions for running this type of filter have been investigated. Compared with other solutions for such system, the model is simple, easy to use, and provides a quick tool for describing such system.