Filtration through roughing gravity filters at low filtration rates between 0.5 and 2 m/h is able to produce water with low particulate concentrations. This allows for further treatment in slow sand filters without the danger of solids overload.
| Title | Filter mechanisms in roughing filters |
| Publication Type | Journal Article |
| Year of Publication | 1993 |
| Authors | Boller, M |
| Pagination | p. 174-185: 17 fig., 1 tab. |
| Date Published | 1993-01-01 |
| Keywords | horizontal roughing filtration, models, particle size, pretreatment, slow sand filtration, suspended solids removal |
| Abstract | Filtration through roughing gravity filters at low filtration rates between 0.5 and 2 m/h is able to produce water with low particulate concentrations. This allows for further treatment in slow sand filters without the danger of solids overload. Sedimentation is the main transport mechanism for suspended solids removal in gravel-type filters. Roughing filter performance depends mainly on: solids concentration, particle-size distribution, filter grain size, layer thickness, and filtration rate. Model calculations of particle transport trajectories in horizontal and vertical-flow filters suggest that horizontal pores are more efficient particle collectors. Roughing filters are particularly appropriate for developing countries because of their high removal rates for colloid size particles without the addition of flocculants, their solids storage capacity at low headloss, and their simple and reliable technology. |
| Notes | 13 ref. |
| Custom 1 | 255.4 |
