chlorine-free disinfection Articles

  • Security Aspects of the Free Chlorine Vs Monochloramine Debate for Disinfection by Product Control

     Introduction: In recent years, there has been a move away from the utilization of free chlorine to maintain a residual level of disinfectant in the distribution system towards the use of monochloramine. The reason behind this change is to decrease the formation of disinfection byproducts (DBPs), which are created when the free chlorine reacts with organic material in the water. The use ...

  • Inactivation of human adenovirus by sequential disinfection with an alternative UV technology and free chlorine

    There has been growing concern over human exposure to adenoviruses through drinking water due to the extreme resistance of human adenoviruses to the traditional UV technology (low-pressure (LP) UV). As an effort to develop an effective treatment strategy against human adenoviruses in drinking water, we determined the effectiveness of sequential disinfection with an alternative UV technology ...


    By IWA Publishing

  • The synergistic effect of Escherichia coli inactivation by sequential disinfection with low level chlorine dioxide followed by free chlorine

    To the best of our knowledge, there was little information available on pathogen removal using low level disinfectant followed by free chlorine in sequential disinfection (SD). This study investigated Escherichia coli inactivation by four types of disinfection: single step disinfection (SSD), SD, traditional sequential disinfection (TSD) and mixed disinfectant disinfection (MDD). Results ...


    By IWA Publishing

  • Ultraviolet Light Oxidation of Free-Chlorine in Water

    Chlorine is the most frequently used chemical for water disinfection. Many industrial and commercial manufacturing facilities cannot tolerate the introduction of chlorine into the process because of contamination and unwanted chemical reactions. Chlorine affects the flavour and odour of drinks and fluids, accelerates corrosion on process vessels and piping, and can also damage delicate process ...

  • What’s the difference between free and total chlorine?

    The element Chlorine exists as a gas Cl2, when this is mixed with water it forms hypochlorous acid (HOCl) which is the disinfecting agent; Cl2 + H2O HCl + HOCl This HOCl can partly disassociate to form the hypochlorite ion ...


    By Camlab Limited

  • Inactivation of Cryptosporidium Parvum oocysts and Clostridium Perfringens spores by a mixed-oxidant disinfectant and by free Chlorine

    Cryptosporidium parvum oocysts and Clostridium perfringens spores are very resistant to chlorine and other drinking-water disinfectants. Clostridium perfringens spores have been suggested as a surrogate indicator of disinfectant activity against Cryptosporidium parvum and other hardy pathogens in water. In this study, an alternative disinfection system consisting of an electrochemically produced ...


    By MIOX Corporation

  • Sequential chlorination for reclaimed water disinfection

    ABSTRACT The Sanitation Districts of Los Angeles County (Districts) operate seven tertiary water reclamation plants (WRPs) with a combined treatment capacity of approximately 200 million gallons per day (MGD). Chloramination is used at these WRPs for effluent disinfection. It was recently discovered that chloramination results in formation of N-nitrosodimethylamine (NDMA), a compound with ...

  • Chlorine Disinfection of Blended Wastewater Effluents

     KeywordsBlended Wastewater, Disinfection IntroductionFlow to publicly owned treatment works (POTWs) increases during wet weather events, due to intrusion of storm water into sanitary collection systems and use of combined sewer systems. When such flows exceed the hydraulic capacity of a POTW alternate flow management techniques must be employed to ensure that ...

  • Accuracy, precision, usability, and cost of free chlorine residual testing methods

    Chlorine is the most widely used disinfectant worldwide, partially because residual protection is maintained after treatment. This residual is measured using colorimetric test kits varying in accuracy, precision, training required, and cost. Seven commercially available colorimeters, color wheel and test tube comparator kits, pool test kits, and test strips were evaluated for use in low-resource ...


    By IWA Publishing

  • Chemistry of Chlorine Application and Production for the Disinfection of Water and Wastewater

     ABSTRACT A thorough understanding of chlorine and sodium hypochlorite chemistry is essential in optimizing their usage in disinfection of water and wastewater. High price of both chemicals and hazards involved in their transportation to plant sites have prompted many utilities to consider generation of these chemical on-site. A detailed discussion of the critical engineering concepts ...

  • Key Operating Strategies for Chlorine Disinfection Operating Systems

    ABSTRACTChlorine has been used as a standard for disinfecting wastewater for many years. While being the standard There are many levels of automation for control of disinfection. To select the best control approach for your facility both control strategies and chlorination chemistry must be understood. Permit conditions must also be fully identified; organism concentrations and operational data. ...

  • Electrochemically activated water as an alternative to chlorine for decentralized disinfection

    Electrochemically activated (ECA) water is being extensively studied and considered as an alternative to chlorine for disinfection. Some researchers claim that ECA is by and large a chlorine solution, while others claim the presence of reactive oxygen species such as ozone and hydroxyl radicals in addition to chlorine. This study compares sodium hypochlorite (NaOCl) and ECA in terms of ...


    By IWA Publishing

  • Chlorination Disinfection Requirements for Membrane Bioreactor Permeate

     ABSTRACT The membrane bioreactor (MBR) process is typically designed and operated to produce a fully nitrified, high quality effluent (permeate) that makes it possible to use free chlorine for disinfection. In California, regulations (Title 22) require a minimum CT value of 450 mg-min/L or 5-log virus inactivation when chlorine is used to produce “disinfected tertiary effluent.” In ...

  • Effect of bacterial growth stage on resistance to chlorine disinfection

    The mechanisms and factors that affect microbial resistance to chlorine disinfection have not been fully elucidated. In this study, we investigated the impact of the cell growth stage on chlorine disinfection efficiency. Specifically, we evaluated the impact of the growth stage on chlorination resistance by comparing the inactivation efficiencies of two indicator bacterial strains (Escherichia ...


    By IWA Publishing

  • Chlorine

    Due to the complexity of chlorine chemistry, the activity and forms of chlorine is not well understood. Its reactions are not always 'predictable' and are somewhat unique. This memo is intended to provide some simple insight of the most common forms of chlorine that we at Osmonics® encounter. The most basic form of chlorine is Chlorine Gas (Cl2). This is usually the cheapest form of chlorination, ...

  • The effect of chlorine and combined chlorine/UV treatment on coliphages in drinking water disinfection

    Chlorine disinfection is a globally used method to ensure the safety of drinking water. However, it has not always been successful against viruses and, therefore, it is important to find new methods to disinfect water. Seventeen different coliphages were isolated from the treated municipal wastewater. These coliphages and MS2 were treated with different dosages of chlorine in drinking water, ...


    By IWA Publishing

  • J555 gasless disinfection

    Detailed design, works manufacture and site installation of Sodium Hypochlorite dosing systems for conversion of 6 sites from Chlorine gas to liquid Sodium Hypochlorite Client: MWH Area: Hertfordshire WES Ltd were involved from early on in the project design stage in developing new Sodium Hypochlorite and Sodium Bisulphite dosing systems for Three Valleys ...


    By WES Ltd / Weschem Ltd

  • Grundfos reference – disinfection case study

    First SELCOPERM unit installed within the Czech Republic to serve for potable water disinfection through the electrical chlorination method ŽLUTICE, Czech Republic: 1/3 of the total capacity of the waterworks at Žlutice has been designed for supplying drinking water to a group of communities found within the catchment area of Žlutice (approximate population of 14,000), the remaining 2/3 ...


  • UV technology - unique in water disinfection

    Due to its undisputable Success &  Efficiency in destroying Cryptosporidium and Combined Chlorine, The Centers for Disease Control and Prevention Recommend installing UV Systems It has taken many years of testing to convince the pool market that the most reliable and best available option for treating and disinfecting water is through using Ultraviolet (UV) technology. UV systems ...


    By ESCO International

  • Reclaimed Water Chlorination: Reducing Chemical Cost and Improving Disinfection Efficiency

     ABSTRACT Irvine Ranch Water District’s (IRWD’s) Michelson Water Reclamation Plant (MWRP) produces 14 MGD of reclaimed water for unrestricted landscape irrigation. The reclaimed water distribution system includes two seasonal storage reservoirs that are considered waters of the State. Nitrogen removal at the plant and dechlorination prior to the reservoirs are therefore required. The ...

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