Effects of waste filter backwash recycle operation on clarification and filtration

Abstract

Research Article| June 01 2003 Effects of waste filter backwash recycle operation on clarification and filtration John E. Tobiason; John E. Tobiason 1Department of Civil and Environmental Engineering, University of Massachusetts, Amherst, MA 01003, USA Tel: +1 413-545-5397 Fax: +1 413-545-2202; E-mail: tobiason@ecs.umass.edu Search for other works by this author on: This Site PubMed Google Scholar James K. Edzwald; James K. Edzwald 1Department of Civil and Environmental Engineering, University of Massachusetts, Amherst, MA 01003, USA Search for other works by this author on: This Site PubMed Google Scholar Vivek Gilani; Vivek Gilani 2Hazen and Sawyer, P.C., Detroit, Michigan, USA Search for other works by this author on: This Site PubMed Google Scholar Gary S. Kaminski; Gary S. Kaminski 3Aquarion Water Company, Bridgeport, CT 06606-5044, USA Search for other works by this author on: This Site PubMed Google Scholar Howard J. Dunn; Howard J. Dunn 3Aquarion Water Company, Bridgeport, CT 06606-5044, USA Search for other works by this author on: This Site PubMed Google Scholar Peter B. Galant Peter B. Galant 3Aquarion Water Company, Bridgeport, CT 06606-5044, USA Search for other works by this author on: This Site PubMed Google Scholar Journal of Water Supply: Research and Technology-Aqua (2003) 52 (4): 259–275. https://doi.org/10.2166/aqua.2003.0025 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Share Icon Share Twitter LinkedIn Tools Icon Tools Cite Icon Cite Permissions Search Site Search nav search search input Search input auto suggest search filter All ContentAll JournalsThis Journal Search Advanced Search Citation John E. Tobiason, James K. Edzwald, Vivek Gilani, Gary S. Kaminski, Howard J. Dunn, Peter B. Galant; Effects of waste filter backwash recycle operation on clarification and filtration. Journal of Water Supply: Research and Technology-Aqua 1 June 2003; 52 (4): 259–275. doi: https://doi.org/10.2166/aqua.2003.0025 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex The effects of recycling waste filter backwash (FBW) on the performance of clarification and filtration were studied with pilot-scale experiments. Two different clarification methods, dissolved air flotation (DAF) and inclined plate sedimentation, were studied alone or in combination with subsequent dual-media (anthracite/sand) filtration. Untreated waste FBW from the on-site full-scale plant was used to examine the effects of four recycling operational variables on treatment performance: FBW recycle rate (10 to 40% of raw flow), FBW pH (baseline of 7, high of 8.5), FBW solids level (baseline and high), and coagulant dosing (constant and reduced). Mixed influent flow (raw plus FBW recycle) was maintained constant throughout the study.Recycling FBW caused slight to moderate increases in clarifier effluent turbidity, with impacts generally increasing as recycle percentage increased. However, the increases in clarifier effluent turbidity were not in proportion to the large increase in clarifier influent solids, i.e. clarifier percent removal performance increased as clarifier loadings increased. Recycling high pH FBW with high soluble NOM and more negatively charged particles resulted in the worse treatment performance. Recycling FBW with baseline or high solids level at pH 7 generally caused moderate impacts on clarifier turbidity and minimal impacts on NOM removal. No impacts were found on filter effluent quality from 20% recycle at high solids and at pH 7, however, recycling high pH FBW caused moderate increases in filter effluent turbidity and NOM during the recycling period. dissolved air flotation, filter backwash recycling, sedimentation This content is only available as a PDF. © IWA Publishing 2003 You do not currently have access to this content.