backwash Articles

  • Filter backwashing

    Backwashng a drinking water system filter means reversing and increasing the water's flow to flush out accumulated debris and particles. Backwashing is not only vital to the life of a filter, it is fundamental to the quality of water coming out of the filter. Sooner or later, all filters need to be backwashed or ...


    By Entech Design, Inc.

  • Gravity self-backwashing filters

    The filtration of make-up and side-stream water in closed cooling circuits, operated through cooling towers, is a fundamental step to ensure safe and continuous operations in a power plant. Water - required in large amounts for this application - should not be wasted, and the potential damages deriving from a poor treatment must be avoided at all cost. BONO ARTES has developed a technical ...


    By Artes Ingegneria SpA

  • Optimizing filter backwashing

    Optimum filter performance has become a critical component of surface water treatment. For conventional and direct filtration systems, LT1ESWTR requires the combined filter effluent turbidity be less than or equal to 0.3 NTU’s for 95% of the readings taken each month. At no time may the readings exceed 1 NTU. As regulations change and filtration is pushed toward the lower limits of turbidity ...


    By Entech Design, Inc.

  • Filter backwashing: When and how

    Backwashing filters is a necessary and important part of the filtration process. Many operating problems associated with the filtration process can be traced to delayed or inadequate backwashing. Producing a high-quality and low turbidity filtered water depends on having clean media free of cracks and mudballs. The Interim Enhanced Surface Water Treatment Rule, promulgated on Dec.16, 1998, lowers ...


    By Entech Design, Inc.

  • 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

  • Spread and backwash effects in ecotourism: implications for sustainable development

    Increasingly, ecotourism is advocated not only as a form of sustainable tourism, but also for the contribution that it can make towards sustainable development. Donor agencies such as DFID and USAID now recognise the contribution that ecotourism can make towards sustainable livelihoods, and it is being advocated as a pro-poor strategy in the developing countries. Ecotourism must not, however, be ...


    By Inderscience Publishers

  • Innovative Multi-Media Filter – Continuous Backwash Filter

    The disadvantages of conventional MMF based pretreatment Conventional pretreatment is based on multimedia filters (MMF) implemented in large scale desalination plants. Although this filtration method is well proven and provides reliable filtration efficiency, it conceals an inherent drawback, the disadvantages of which relate mainly to the backwashing mechanism. The ...


    By IDE Technologies

  • 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 ...

  • 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

  • Recovery and Reuse of Filter Backwash Water: Coca-Cola Amatil

     Background The Coca Cola Amatil (CCA) Northmead plant in Sydney was established in 1972 and manufactures a wide range of world recognised Coca-Cola trademark soft drink products, such as Sprite, Fanta, Lift and Coca-Cola. The Northmead plant has one aluminium can line and two plastic PET bottle lines. It produced over 250 million litres of soft drink in 1995. ...


  • Ceramic membrane ultrafiltration of natural surface water with ultrasound enhanced backwashing

    Ultrafiltration membrane cleaning with ultrasound enhanced backwashing was investigated with two ceramic membrane systems in parallel. One of them was subjected to ultrasound during backwashing, the other acted as a reference system. The feed water was directly taken from a creek with a sedimentation process as only pre-treatment. The cleaning performance was improved with ultrasound but after 3 ...


    By IWA Publishing

  • Recycle of waste backwash water in ultrafiltration drinking water treatment processes

    In drinking water treatment, ultrafiltration (UF) membrane systems are generally operated at 90 to 95% recovery with production losses resulting from waste residual streams such as backwash water and clean-in-place (CIP) liquid residuals. In drought-prone regions, it may be desirable to apply alternative UF plant design configurations to increase recovery rates and minimize water loss. This ...


    By IWA Publishing

  • Monitoring the fate of fluorescing substances recycled in ultrafiltration process backwash water

    The fate of fluorescing substances during the recycling of membrane backwash water (MBWW) ahead of coagulation, flocculation and sedimentation (CFS) with ultrafiltration (UF) membranes has been investigated. Bench-scale UF membranes were used to generate MBWW from a CFS-treated surface water containing 21 mg/L dissolved organic carbon (DOC) registering a 0.95 cm–1 UV254 absorbance that ...


    By IWA Publishing

  • Treatment of Spent Filter Backwash Wastewater Using Dissolved Air Flotation Process

    Spent Filter Backwash Water (SWW) is a major recycle stream that accounts for 10% (about 30 mgd) of the average flow at Blue Plains Advanced Wastewater Treatment Plant (AWTP) and a similar proportion of nitrification and denitrification treatment process capacity (DCWASA Focus, November 2004). The peak SWW flow and load result from increased filter washing during high flow events. The combined ...

  • 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

  • Application of backwashing with demineralized water for UF fouling control in UF-RO desalination

    The effectiveness of demineralized water backwash on ultrafiltration (UF) fouling control of seawater is investigated in this study. Fouling experiments for two different backwashes (UF permeate and demineralized water) were conducted at three fluxes: 120, 180 and 240 L/(h m2) to compare their fouling control efficiency on UF membranes. Results show that backwashing with demineralized water ...


    By IWA Publishing

  • A pilot-scale study of backwashing ultrafiltration membrane with demineralized water

    This study investigates the effectiveness of different backwash waters on ultrafiltration (UF) fouling control on a pilot-scale setup. Surface water and ion exchange (IEX) pretreated surface water were used as feed water. Three backwash waters were tested: demineralized water, UF permeate and nanofiltration (NF) permeate. Results show that backwashing with demineralized water substantially ...


    By IWA Publishing

  • 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

  • Preliminary study on novel backwash cleaning for reverse osmosis fouling control in water reuse

    We have demonstrated a novel backwash cleaning technique of direct osmosis (DO)-high salinity (HS) for reverse osmosis (RO) fouling control in water reuse. An UF-RO pilot system was continuously (24-h) operated on site with the secondary effluent as the feed over 4 months. The RO plant was run at 75% recovery and at the membrane flux of 17 l m−2 h−1 (LMH) to simulate the full scale NEWater ...


    By IWA Publishing

  • Recycling of spent filter backwash water using coagulation-assisted membrane filtration: effects of submicrometre particles on membrane flux

    Membrane separation technology has been widely used for recycling of spent filter backwash water (SFBW) in water treatment plant. Membrane filtration performance is subject to characteristics of the particles in the SFBW. A bench-scale microfiltration (MF) coupled with pre-coagulation was set up to evaluate the recovery efficiency of SFBW. Effect of particle size distribution and zeta potential ...


    By IWA Publishing

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