Download or read book Assessment of Auxiliary Backwash Methods for Rapid Sand Filters written by Richard C. Pohlman and published by International Water Assn. This book was released on 2006 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: An audit was performed in 1996 and 1998 at GCWW;s Richard Miller Treatment Plant (RMTP) to insure compliance with all current and proposed state and federal maximum contaminant levels. During the audit, training in filter profiling, including coring and floc retention analysis, was provided. Through these techniques, GCWW determined that the filter media was not getting effectively cleaned. Auxiliary backwash was recommended, but no experimental protocol was available to choose among available options. Four filters at RMTP were rebuilt for this study. New Leopold dual parallel lateral type block underdrains with integral media support (IMS) caps were installed. The sand media was completely replaced. Two filters were outfitted with air scour, one with surface wash and one was rebuilt with no auxiliary wash. The backwash procedures were then optimized and standardized before initiating the study. Turbidity and microbial testing were performed at various time intervals throughout the filter run to characterize the quality of the filter effluent. The magnitude and duration of the initial solids breakthrough were determined by the use of continuous turbidimeters and a supervisory control and data acquisition (SCADA) system. Filter cores and floc retention analyses were used to determine the filter media cleanliness.
Download or read book Assessment of Auxiliary Backwash Method for Rapid Sand Filters written by Richard C. Pohlman and published by American Water Works Association. This book was released on 2006 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary objective of this project was to determine differences in filter effluent water quality and media cleanliness between sand filters employing air scour and those employing surface wash. Discussed in detail are the findings that scour and surface wash systems performed similarly relative to filter effluent quality and filter cleanliness. The advantages of one system over another can be site-specific particularly in retrofit applications.
Download or read book Backwash Instability in Rapid Sand Filters written by Peter A. Norman and published by . This book was released on 1970 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Filter Evaluation Procedures for Granular Media written by Daniel K. Nix and published by . This book was released on 2003 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: &Quot;Filter Evaluation Procedures for Granular Media takes you through all of the granular filter test procedures that water professionals need to know. This book will give water industry personnel the guidance needed to produce the highest level of finished water quality for the protection of public health."--BOOK JACKET.
Download or read book Water Filtration Practices written by Gary S. Logsdon and published by American Water Works Association. This book was released on 2011-01-12 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water operators will find a wealth of hands-on information on the operation and maintenance of pretreatment, rapid-rate granular media filtration, slow-sand filtration, and diatomaceous-earth filtration systems in this book. This practical guide provides recommended procedures for operating, monitoring, and maintaining all types of filters used for conventional water treatment. These procedures are tested and time-proven by hundreds of water utilities and filtration experts to provide high filter efficiency, excellent water quality, long filter runs and minimum downtime. The book also gives advice on what not to do-and why-so you can avoid water quality problems, filter damage, and treatment problems in the future.
Download or read book The backwashing of rapid sand filters written by Salim Erol Ulug and published by . This book was released on 1967 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Filter Media Modification in Rapid Sand Filtration written by Po-Hsun Lin and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective of this research was to improve the filtration technologies to make them more sustainable and accessible. This study focused on developing improved operating methods for rapid sand filtration technology that would not require costly infrastructure upgrades to implement. Unlike previous filter media modifications conducted by other researchers, the filter media in this study was modified in situ. Process Controller software was used for automation of the test apparatus facilitating systematic variation of parameters and replication of results. Several different coagulants at varying dosages were applied by either downflow or upflow to modify a sand filter medium. Initially coagulants were added in downflow mode to the top of a 7.5 cm deep sand column prior to challenging the filter with an otherwise untreated kaolin suspension. Three coagulants, alum (Al2(SO4)3[BULLET]14H2O), ferric chloride (FeCl3), and polyaluminum chloride (PACl), were utilized separately to modify the sand filter medium. After modification of the filter medium, an initial particle removal of 96% was achieved by all coagulants versus 60% removal in the absence of pretreatment. Pretreatment with PACl and alum showed increasing particle removal with increasing dosage up to a maximum of 550 mmol Al/m2 after which filter performance declined. Pretreatment with FeCl3 increased particle removal over the entire range of dosages evaluated (70 to 2200 mmol Fe/m2) but headloss through FeCl3 treated filters became prohibitive at the highest dosage. Although downflow application of coagulant showed promise there was strong evidence that better performance and lower head loss would be possible if a more uniform application of the coagulant throughout the filter could be attained. Thus, a novel fluidized-bed pretreatment process was developed to modify the sand medium at the end of the backwash cycle of the filter. During backwash, a mixture of alum, base, and tap water were pumped into the filter upward from the bottom. The ensuing precipitation of Al(OH)3(am) in the filter pores enhanced the efficiency of turbidity removal from untreated raw water (up to 99.6%) without a substantial increase of head loss ([ALMOST EQUAL TO]14 cm). While pretreatment with Al(OH)3(am) was effective at enhancing particle removal, measurements of dissolved aluminum in the filter effluent showed that this process modification should only be considered for waters with circumneutral pH. At pH of 8 a pretreatment dosage of 16 mol Al/m3 resulted in effluent dissolved Al in excess of the EPA secondary drinking water standard of 0.05~0.2 mg/L. To clearly understand the fundamental aspects of the enhanced particle removal by fluidized-bed pretreatment with Al(OH)3(am), two alternative mechanisms were hypothesized: (1) Al(OH)3(am) coats the sand filter medium, and alters its porosity. (2) Precipitated Al(OH)3(am) embedded within the media pores acts as an additional filter medium that enhances the particle removal efficiency. Mathematical models for these two mechanisms were constructed and compared with experimental data for particle removal and head loss. Model predictions suggest that particle removal by the second mechanism, filtration through Al(OH)3(am) flocs, can account for the observed improvement of the filter performance.
Download or read book American Book Publishing Record written by and published by . This book was released on 2006 with total page 834 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydraulics of Backwashing Rapid Sand Filters written by Robert Charles Hanlon and published by . This book was released on 1936 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Economic analysis for the filter backwash recycling rule written by and published by DIANE Publishing. This book was released on 2001 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Improving Initial Filtrate Quality of Rapid Sand Filter written by Chandrakant Wagh and published by LAP Lambert Academic Publishing. This book was released on 2019-10-21 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Need of water purification was realized by man in early stages of civilization. So, Central and State Government are making efforts to provide adequate and safe drinking water to the people by constructing water treatment plants in the country. Filtration process under goes degradation at initial and last phase which affect the initial effluent quality of filtrate after back washing. The rapid sand filter is important unit of water treatment plant which removes the flocs and colloids through filtration After backwash filter when rapid sand filter brought back in to normal operation high initial turbidity of filtrate is observed. It is in the form of turbidity spike. To reduce this turbidity spike filter conditioning is essential. The present study is for rapid sand filter conditioning using coagulants as alum and polymer in different percentage during backwash of rapid sand filter. The optimal dosage as well as corresponding points of application during backwash will be determined based on laboratory scale studies which found to be improved in initial effluent quality of rapid sand filter.
Download or read book Technology Assessment of Intermittent Sand Filters written by Damann L. Anderson and published by . This book was released on 1985 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of High Rate Sand Filters with Rapid Sand Filters for Use in Public Swimming Pools written by James Rodgers and published by . This book was released on 1978 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Water Filtration Practices written by Gary S. Logsdon and published by . This book was released on 2008 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written for experienced plant staff, this book covers granular media filters, identification of deficiencies, and optimization with rapid gravity filtration or pressure processes, plus information on slow sand filters and precoat filtration.
Download or read book EPA 440 1 written by and published by . This book was released on 1980-12 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development Document for Proposed Effluent Limitations Guidelines New Source Performance Standards and Pretreatment Standards for the Iron and Steel Manufacturing Point Source Category Hot forming subcategory written by and published by . This book was released on 1981 with total page 942 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Laboratory Rapid Sand Filters written by Arun K. Deb and published by . This book was released on 1961 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:
