A study of performance of ground charcoal as the Coarse medium in dual media filtration of potable

Abstract

The study investigated the performance of ground charcoal as the coarse medium in dual media filtration of potable water. Filtration tests were carried out on bench scale models to assess the performance of the dual media filter as compared to a conventional rapid sand filter for the same influent water quality. The analyses commenced by assessing the media characteristics, namely, appearance, size, relative density, acid solubility, and physical stability. The performance of the filters was evaluated on the basis of turbidity removal, headloss development, and backwashing requirements. The results from the filtration tests showed better performance of the ground charcoal dual media filter as compared to the conventional rapid sand filter. The dual media filter exhibited a removal capacity between 1.5 to 2 times that of the conventional rapid sand filter. The rapid sand filter registered a higher rate of headloss development than the dual media filter, and needed about 1.1 times more water for backwashing than the dual media filter. The dual media filter also exhibited a unique quality of removal of organic particulates from the raw water. The results obtained showed that the ground charcoal can be applied as a coarse, light medium in dual media filtration of potable water. However, further research was recommended on the applicability of this media. The application of charcoal IS also economically sound due to its widespread availability throughout the country.