Title | Langsamfilter bei der Grundwasseranreicherung : zehnmal laengere Laufzeit als bisher |
Publication Type | Journal Article |
Year of Publication | 1991 |
Authors | Schalekamp, M |
Pagination | p. 552-561 : 45 fig. |
Date Published | 1991-08-01 |
Keywords | activated carbon treatment, artificial recharge, maintenance, operation, slow sand filtration, switzerland zurich |
Abstract | In 1971 the slow sand filters of the Lakewater Plant Lengg, Zurich, Switzerland, which were charged with a 10 cm thick layer of activated carbon PKST 0.5-2.5 mm, showed a six-times longer filter run than those without activated carbon. This discovery lead to the construction of the Hardhof groundwater recharge basins. All recharge basins, each with an area of about 4,000 sqaure metres, were charged with a 10 cm layer of activated carbon PKST 0.5-2.5 mm and covered by a 1.2 mm thick layer of synthetic fabric. After ten years filter basin No. 3 was cleaned. The fabric layer, the activated carbon, and 7.5 cm of sand were removed. Instead of expensive activated carbon, easily washable gravel of 3-6 mm grain was charged and again the filter was covered by a layer of fabric. Pressure losses after this cleaning prcoess are as low as they were ten years before. |
Notes | 18 ref. |
Custom 1 | 212.2, 255.1 |
Translated Title | Slow sand filter for ground-water recharge : ten times longer filter run than was usual up to now |