Backwash Filters Articles

  • The role of backwash in start-up of full-scale drinking water biofilters

    The purpose of backwashing during the start-up period of rapid biofilters at drinking water treatment plants differs significantly from the purpose of backwashing during normal operation. During start-up, finished water quality is secondary, detachment of microorganisms must be minimized, dust present in the original filter media must be removed and inherent inoculation of the biofilter with ...


    By IWA Publishing

  • Optimum backwashing conditions and ammonium-nitrogen treatment efficiency of iron oxide modified sands coated in biofilm

    In this study, iron oxide modified sands with nano-pores (IOMSNP) were enveloped in biofilm (B-IOMSNP) in order to treat the ammonium-nitrogen (NH4+-N) in micro-polluted raw water. The biomass, optimum backwashing conditions, treatment efficiency, and surface morphological properties of the B-IOMSNP were investigated via bio-filtration experiments. The raw quartz sands (RQS) and IOMSNP ...


    By IWA Publishing

  • Effective production of rapid filters with polystyrene granules as a media filter

    In conventional water treatment stations, the filter cleaning is performed with the use of filtered water. To save water and obtain higher production, the use of polystyrene (PS) beads has been proposed as a granular filter element because it is a granular element with a low specific mass. By being lightweight, this material requires a lower water velocity during backwash. The PS beads were ...


    By IWA Publishing

  • Confirmation of the correlation between membrane fouling in microfiltration and biopolymer concentrations in various Japanese surface waters

    A variety of surface waters used for drinking water sources were collected from different parts of Japan to investigate a correlation between the concentration of hydrophilic biopolymer (e.g. proteins and polysaccharides) in the feed water and membrane fouling in microfiltration. Hollow-fiber membranes made from polyvinylidene fluoride with a nominal pore size of 0.1 μm were used in the ...


    By IWA Publishing

  • Filter backwash water treatment options

    Filtration acts as the final step in the removal of suspended matter and protozoa. The accumulated residue is removed during the backwash process and any subsequent recycling of filter backwash water could potentially re-introduce these contaminants into the main treatment process. By separating the filter backwash water from the main treatment process, factors that could interfere with the ...


    By IWA Publishing

  • Influence of air flow rate and backwashing on the hydraulic behaviour of a submerged filter

    The aim of this study was to evaluate backwashing effects on the apparent porosity of the filter media and on the hydraulic behaviour of a pilot scale submerged filter, prior to biofilm colonization, under different hydraulic retention times, and different air flow rates. Tracer curves were analysed with two mathematical models for ideal and non-ideal flow (axial dispersion and Wolf and Resnick ...


    By IWA Publishing

  • Grey water recycling for Internationally Renowned Merchant Bank

    New Nomura building water recycling system passes the test of time. One Angel Lane, the iconic new European headquarters of Nomura in the City of London, has a comprehensive grey water and rainwater water combined system providing 100% of water for toilet flushing on the first five floors of this eleven floor building. Installed by Aquaco in June 2008, the system is working to the ...

  • Nitrogen-removal efficiency in an upflow partially packed biological aerated filter (BAF) without backwashing process

    An upflow, partially packed biological aerated filter (BAF) reactor was used to remove nitrogen in the form of ammonia ions by a nitrification process that involves physical, chemical and biological phenomena governed by a variety of parameters such as dissolved oxygen concentration, pH and alkalinity. Dissolved oxygen (DO) and pH were shown to have effects on the nitrification process in this ...


    By IWA Publishing

  • Knowledge-based system for automatic MBR control

    MBR technology is currently challenging traditional wastewater treatment systems and is increasingly selected for WWTP upgrading. MBR systems typically are constructed on a smaller footprint, and provide superior treated water quality. However, the main drawback of MBR technology is that the permeability of membranes declines during filtration due to membrane fouling, which for a large part ...


    By IWA Publishing

  • Removal of heavy metals in an abandoned mine drainage via ozone oxidation: a pilot-scale operation

    The objective of this study was to evaluate the ozone oxidation of dissolved heavy metals in an abandoned mine drainage (AMD) by conducting a pilot-scale operation at two different ozone doses of 7.5 and 24.0 g O3/h into an ozone reactor. A portion of the abandoned mine drainage near the Jungam Mine in Samchuck, Korea was pumped into this pilot-scale plant and used as an influent for the ozone ...


    By IWA Publishing

  • Removal of heavy metals in an abandoned mine drainage via ozone oxidation: a pilot-scale operation

    The objective of this study was to evaluate the ozone oxidation of dissolved heavy metals in an abandoned mine drainage (AMD) by conducting a pilot-scale operation at two different ozone doses of 7.5 and 24.0 g O3/h into an ozone reactor. A portion of the abandoned mine drainage near the Jungam Mine in Samchuck, Korea was pumped into this pilot-scale plant and used as an influent for the ozone ...


    By IWA Publishing

  • Mining clarifier overflow

    Project Profile: Clarifier Overflow Water Polishing: PFD  Data: End User: US Energy Location: Crested  Butte, CO Commissioned: Spring, 2010 Units: (1) model STiR-50V (50 ft2/filter) Flow Rate: 300 gpm (0.5 Million gallons of water per day) ...


    By Filtra Systems

  • A study of feasibility for water purification using vertical porous concrete filter

    Abstract: There is a need to find cheaper and simpler techniques for rural water filtration system in developing countries. Using a filter made of blocks for the water treatment enables one to make vertical filters. It is expected that the amount of land utilized would decrease by more than 70 % if vertical filters were used. The operation and washing would be simpler than using horizontal sand ...

  • Hong Kong University of Science & Technology Outdoor Swimming Pool

    The Site: The outdoor swimming pooi has three sand filters, two carbon filters and one ozonator. The ozonator broke down regularly, whenever the temperature in the operating room was too high. The Ozonator was used because management wanted to reduce the chiorine dosage from 3ppm to lppm. Back washing frequency of the sand filters was weekly and the carbon in the carbon filters was replaced ...

  • Pilot Testing of Upflow Continuous Backwash Filters for Tertiary Denitrification and Phosphorus Removal

    ABSATRACTPilot testing of upflow continuous backwash filter (UCB) for tertiary denitrification and phosphorus removal was conducted at the Hagerstown wastewater treatment plant. The pilot testing was conducted to determine denitrification performance capabilities of the upflow continuous backwash filters under cold weather operation and low effluent total nitrogen (TN) and total phosphorus ...

  • World War II Memorial, DC - Case Study

    In 2003, AdEdge Water Technologies began working closely with EarthTech, the assigned engineering firm responsible for specifying and selecting the various water treatment systems serving the new National World War II Monument in Washington, DC. Stormwater and groundwater control and treatment are essential aspects of this project given the location of the site on the Mall adjacent to the ...

  • Bed expansion affects performance

    The experience of Pennsylvania Department of Environmental Protection staff over 14 years conducting filter plant performance evaluations led investigators to identify a coomon thread:'inadequate filter bed expansion eventually contributes to poor filter performance and reduced finished water quality.' The article points our that and insufficiently expanded filter is insufficiently cleaned, and ...


    By Entech Design, Inc.

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