secondary disinfection Articles

  • UV disinfection of wastewater flocs: the effect of secondary treatment conditions

    Activated sludge flocs that are carried to the final effluent can significantly decrease the effectiveness of ultraviolet (UV) disinfection of wastewater. This effect is detected in a typical UV dose–response curve, where at higher UV doses there is a decrease in the inactivation rate (tailing). In this study, the effect of activated sludge process conditions on the UV inactivation ...


    By IWA Publishing

  • Peracetic acid for secondary effluent disinfection: a comprehensive performance assessment

    The paper is a review of previous research on secondary effluent disinfection by peracetic acid (PAA) integrated with new data about the effect of a preliminary flash-mixing step. The process was studied at bench and pilot scale to assess its performance for discharge in surface water and agricultural reuse (target microorganisms: Escherichia coli and faecal coliform bacteria). The purposes ...


    By IWA Publishing

  • Electrochemical disinfection of secondary wastewater treatment plant (WWTP) effluent

    In this work the electrochemical disinfection of the effluent of a secondary wastewater treatment plant is investigated. In the experimental work, performed on-site with real effluents of the WWTP located in Vuelta Ostrera (Cantabria, Spain), boron-doped diamond (BDD) electrodes were employed. The initial concentration of E. coli in the effluent of the WWTP varied in the range ...


    By IWA Publishing

  • Elimination of enteric indicators and pathogenic bacteria in secondary effluents and lake water by solar disinfection (SODIS)

    The reduction of enteric indicators (fecal coliforms (FC) and Enterococcus faecalis) and elimination of pathogenic bacteria (Salmonella spp. and Staphylococcus aureus) in the secondary effluents and lake water by solar disinfection (SODIS) was studied in this article. FC, E. faecalis, Salmonella spp. and ...


    By IWA Publishing

  • Effect of ozone on secondary effluent treatment for reuse in agriculture

    The results of secondary effluents ozonation from domestic sewages treatment plants in Havana, Cuba are presented. The ozone effect on some physico-chemical parameters was determined. The ozone gas concentration is the parameter, which exerts the greatest influence on the ozone transferred. The results indicated that ozonation of secondary effluents is a safe disinfection alternative for ...


    By Inderscience Publishers

  • 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 ...

  • Using Ozone Disinfection for EDC Removal

    Clark County Water Reclamation District (CCWRD) serves the suburban area in and around the city of Las Vegas. The Las Vegas Valley is served by three treatment plants, which all discharge to the Las Vegas Wash. The wash empties into the Las Vegas Bay of Lake Mead. Lake Mead is also the source of drinking water for the Las Vegas Valley. In 1996 USGS reported symptoms of estrogen exposure in carp ...

  • 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 ...

  • Performic acid for advanced wastewater disinfection

    The disinfection efficiency of performic acid (PFA) against various microbial contaminants has been studied in municipal secondary effluent. The study demonstrated that PFA provides rapid, efficient and safe disinfection, degrading both bacteria and viruses even at low doses. The resistance order starting from the most resistant microorganism is as follows: MS2-coliphages > DNA-coliphages ...


    By IWA Publishing

  • A Regulatory Perspective on Maintenance of Disinfection Systems

    ABSTRACTThe Clean Water Act contains requirements to set water quality standards for all contaminants, including bacterial contaminants, in surface waters. Wastewater treatment cannot be expected to remove all of the bacterial contaminants, and as a result, many organisms remain in the waste stream. Therefore, disinfection of treated wastewaters is designed to reduce bacterial numbers to a safe ...

  • Photocatalytic inactivation of E. faecalis in secondary wastewater plant effluents

    Photocatalytic inactivation of Enterococcus faecalis using TiO2 suspensions was investigated and compared to the inactivation of the most commonly used faecal indicator strain Escherichia coli. In contrast to the inactivation in pure deionized water, disinfection of effluents from the biological process of an urban wastewater plant showed a longer initial lag phase and higher ...


    By IWA Publishing

  • Combined physico-chemical treatment of secondary settled municipal wastewater in a multifunctional reactor

    In this paper, the physico-chemical treatment of municipal wastewater for the simultaneous removal of pollutant indicators (chemical oxygen demand (COD) and total coliforms) and organic contaminants (total phenols) was investigated and assessed. A secondary settled effluent was subjected to coagulation, disinfection and absorption in a multifunctional reactor by dosing, simultaneously, aluminum ...


    By IWA Publishing

  • An antimicrobial polycationic sand filter for water disinfection

    A new sand filtration water disinfection technology is developed which relies on the antimicrobial properties of hydrophobic polycations (N-hexylated polyethylenimine) covalently attached to the sand's surface. The efficacy of the filter disinfection process was evaluated both with water spiked with E. coli and with real aqueous effluent from a wastewater treatment plant. For the ...


    By IWA Publishing

  • Antimicrobial resistance of fecal indicators in disinfected wastewater

    The main objective of the study was to assess the potential of three systems (UV irradiation, ozonation, and micro/ultrafiltration) operated in a pilot scale in removal of antimicrobial-resistant fecal bacteria from secondary effluent of the local wastewater treatment plant (700,000 population equivalent). The effectiveness of the processes was analysed using the removal ratio of fecal indicators ...


    By IWA Publishing

  • Operating Chemically Enhanced Clarification for Optimum Disinfection Performance

    ABSTRACTThe Milwaukee Metropolitan Sewerage District conducted demonstration tests in 2005 to evaluate chemically enhanced clarification (CEC) of wet-weather flows at the District’s two wastewater treatment plants (WWTPs). CEC offers the potential to treat intermittent high wetweather flows, produce high-quality effluent, and fit into the limited space at the plant sites. Two CEC processes were ...

  • Sustainable, Low-maintenance Disinfection for Onsite Systems

    Most of the regulations applicable for onsite wastewater treatment system are based on the use of native soil for effluent dispersal. However, there are more and more situations where dispersal of effluent in native soil is impossible: repairs of existing systems on undersized lots for implementation of required dispersal fields: sites located in soils having low permeability: or where the ...


    By Premier Tech Aqua

  • The Challenge of the Future: Operating Emerging Disinfection Technologies

    ABSTRACTThe Clean Water Act (1972 and 1977) established the basis for regulating pollutant discharges into the waters of the United States. This Act contains many provisions regulating pollutant discharges and surface water quality in the United States. This act has also been modified by numerous revisions and amendments since it was enacted in 1972. The National Pollutant Discharge Elimination ...

  • Photoreactivation and subsequent solar disinfection of Escherichia coli in UV-disinfected municipal wastewater under natural conditions

    Photoreactivation of ultraviolet (UV)-disinfected wastewater of different qualities was experimentally assessed. Photoreactivation ability of secondary effluent and microstrained inflow was analyzed in different samples of 50 mL (Petri dish) and 7,000 mL volume to describe open channel effluent situations of wastewater treatment plants in a more realistic approach. The small sample of secondary ...


    By IWA Publishing

  • Evaluation of the UV disinfection process in bacteria and amphizoic amoebae inactivation

    Abstract: Every year around 3.4 million people die from water-related diseases, mainly amoebiasis and diarrhoea caused by bacteria. The assessment of the efficiency of a UV light disinfection process in the inactivation of indicators, pathogen bacteria and amphizoic amoebae in a secondary treated effluent was carried out. Wastewater was irradiated with different doses of UV light using a ...

  • Optimizing the Removal and Disinfection of Microorganisms Occluded within Wastewater Particles

     ABSTRACT A procedure is presented that provides the basis for optimizing filtration and disinfection systems by assuring that microorganisms occluded in effluent particles are sufficiently inactivated or removed. A secondary effluent sample was collected from an operational treatment facility and used in a series of laboratory tests. Experimental data were then used to calibrate a ...

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