Title | Study of a horizontal-flow roughing filter for pretreatment prior to slow sand filtration |
Publication Type | Conference Paper |
Year of Publication | 1988 |
Authors | Williams, PG |
Pagination | Paper A.2 (11 p.): fig., tab. |
Date Published | 1988-01-01 |
Keywords | chemical quality, horizontal roughing filtration, microbiological quality, pilot plants, pretreatment, slow sand filtration, south africa lebowa moganyaka, turbidity removal |
Abstract | A pilot plant study to assess the effectiveness of a horizontal roughing filter as a pretreatment to slow sand filters, was conducted over a 15 month period from Nov. 1984 to Feb. 1986 at Moganyaka village, Lebowa, South Africa. The roughing filter reduced the influent turbidity by between 70 and 85%, as well as reducing colour, iron, and bacterial counts. Slow sand filter run lengths increased from less than one month to between 2 and 6 months. Cleaning of the roughing filter after 15 months of operation took 2 weeks. Design simplifications are recommended. As a result of the study, full-scale roughing filters have been constructed at 2 treatment plants (100,000 l/day each) in Ciskei. |
Notes | 5 ref. |
Custom 1 | 255.4 |