Breakthrough Index and Specific Deposit in Dual Filters

Abstract

The dual filter was tested in this study to improve the performance of the filtration process in water treatment plants. Porcelanite rocks were selected to be the dual media with sand in the experimental work. The work required installing a pilot filtration unit in the location of the filters in one of the water treatment plants. The pilot filtration consists of three plastic column filters, acting parallel and simultaneously. The first contains 70 cm sand, the second and third were dual filters (porcelanite with sand) of different types. The dual media was tested at different filtration rates (5, 7.5, 10, and 15 m/hr). The results showed that the dual filters had better performance than sand filters and reduced the specific deposit ( ) and the breakthrough index (BI). In the dual filters the specific deposit was about (16 to 65 %) less than in sand filters and the breakthrough index (BI) was specified weak for rates 5 and 7 m/hr, light at 10 m/hr, and medium at 15 m/hr..