Attrition of granular filter media during backwashing with combined air and water Humby, M S; Fitzpatrick, C S.B. [Cranfield University, Cranfield (United Kingdom). School of Water Science] 01 COAL, LIGNITE, AND PEAT; GRANULAR BED FILTERS; ANTHRACITE; WATER TREATMENT; ABRASION; SAND; ACTIVATED CARBON Attrition resistance of granular filter media is becoming increasingly important as materials such as GAC and anthracite are being more frequently used as filter media. The purpose of this study was to evaluate the attrition experienced by various media during backwashing by performing accelerated backwash tests in a pilot column, using a combined water and air backwash at combinations that gave the condition known as collapse-pulsing. Since the dominant mode of attrition was assumed to be abrasion, the effluent was sampled at a number of intervals to determine the amount of fine material in the effluent. Coal-based GAC exhibited the highest weight loss (similar to 7%) and sand the least (similar to 2%). United Kingdom 1996-02-01 English Journal Article Journal Name: Water Research; Journal Volume: 30; Journal Issue: 2; Other Information: PBD: Feb 1996 Medium: X; Size: pp. 291-294 https://doi.org/10.1016/0043-1354(95)00177-8 [] 2 30 Journal ID: WATRAG; ISSN 0043-1354; TRN: 960700820 CLA; SCA: 010500; 010800; PA: CLA-96:070820; EDB-96:090817; SN: 96001604551 2010-12-29 241550