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Sample records for field-testing uv disinfection

  1. Field-testing UV disinfection of drinking water

    SciTech Connect

    Gadgil, A.; Drescher, A.; Greene, D.; Miller, P.; Motau, C.; Stevens, F.

    1997-09-01

    A recently invented device, ``UV Waterworks,`` uses ultraviolet (UV) light to disinfect drinking water. Its novel features are: low cost, robust design, rapid disinfection, low electricity use, low maintenance, high flow rate and ability to work with unpressurized water sources. The device could service a community of 1,000 persons, at an annual total cost of less than 10 US cents per person. UV Waterworks has been successfully tested in the laboratory. Limited field trials of an early version of the device were conducted in India in 1994--95. Insights from these trials led to the present design. Extended field trials of UV Waterworks, initiated in South Africa in February 1997, will be coordinated by the South African Center for Essential Community Services (SACECS), with technical and organizational support from Lawrence Berkeley National Laboratory(LBNL) and the Natural Resources Defense Council (both US). The first of the eight planned sites of the year long trial is an AIDS hospice near Durban. Durban metro Water and LBNL lab-tested a UV Waterworks unit prior to installing it at the hospice in August, 1997. The authors describe the field test plans and preliminary results from Durban.

  2. UV disinfection for onsite sand filter effluent

    SciTech Connect

    Lowery, J.D.; Romatzick, S.

    1982-05-01

    The technical and economic feasibility of using ultraviolet (uv) light as a viable alternative to chlorine as the required disinfectant for onsite sand filter effluents discharged to surface waters in Maine was determined. To obtain a reliable cross section of performance for sand filters in Maine, 74 filters were selected for an effluent characterization program. The effluent characterization study allowed general conclusions to be made with regard to the potential of uv disinfection. A simple suspended lamp uv disinfection unit was designed, constructed, and tested in the laboratory and in the field. The efficiency of the uv disinfection unit was determined through field testing at 10 of the 74 sand filter sites used in the effluent characterization program.

  3. Ultraviolet (UV) Disinfection for Drinking Water Systems

    EPA Science Inventory

    UV disinfection is an effective process for inactivating many microbial pathogens in water with potential to serve as stand-alone treatment or in combination with other disinfectants. USEPA provided guidance on the validation of UV reactors nearly a decade ago. Since then, lesson...

  4. DETECTION OF INFECTIOUS ADENOVIRUS IN TERTIARY TREATED AND UV DISINFECTED WASTEWATER DURING A UV DISINFECTION PILOT STUDY

    EPA Science Inventory

    An infectious enteric adenovirus was isolated from urban wastewater receiving tertiary treatment and ultraviolet (UV) disinfection. A pilot study was undertaken to investigate the efficacy of UV disinfection (low pressure, high intensity radiation) of total and fecal coliform bac...

  5. UV Disinfection System for Cabin Air

    NASA Astrophysics Data System (ADS)

    Lim, Soojung

    Ultraviolet (UV) radiation is commonly used for disinfection of water. As a result of advancements made in the last 10-15 years, the analysis and design of UV disinfection systems for water is well developed. UV disinfection is also used for disinfection of air; however, despite the fact the UV-air systems have a longer record of application than UV-water systems, the methods used to analyze and design UV-air disinfection systems remain quite empirical. It is well-established that the effectiveness of UV-air systems is strongly affected by the type of microorganisms, the irradiation level/type (lamp power and wavelength), duration of irradiation (exposure time), air movement pattern (mixing degree), and relative humidity. This paper will describe ongoing efforts to evaluate, design and test a UV-air system based on first principles. Specific issues to be addressed in this work will include laboratory measurements of relevant kinetics (i.e., UV dose-response behavior) and numerical simulations designed to represent fluid mechanics and the radiation intensity field. UV dose-response behavior of test microorganism was measured using a laboratory (bench-scale) system. Target microorganisms (e.g., bacterial spores) were first applied to membrane filters at sub-monolayer coverage. The filters were then transferred to an environmental chamber at fixed relative humidity (RH) and allowed to equilibrate with their surroundings. Microorganisms were then subjected to UV exposure under a collimated beam. The experiment was repeated at RH values ranging from 20% to 100%. UV dose-response behavior was observed to vary with RH. For example, at 100% RH, a UV dose of 20 mJ/cm2 accomplished 90% (1 log10 units) of the B. subtilis spore inactivation, whereas 99 % (2 log10 units) inactivation was accomplished at this same UV dose under 20% RH conditions. However, at higher doses, the result was opposite of that in low dose. Reactor behavior is simulated using an integrated application

  6. Bioassay and dose measurement in UV disinfection.

    PubMed Central

    Qualls, R G; Johnson, J D

    1983-01-01

    A bioassay method was developed to measure the average intensity within a UV disinfection reactor. The survival of spores of Bacillus subtilis was determined as a function of UV dose to prepare a standard curve. Spores were added to unknown systems, and the survival rate was used to determine the average intensity. A modification was used for flow-through reactors by which spores were injected as a spike and collected at a known time after injection. A point source summation method for calculating intensity was verified by bioassay measurements in a simple cylinder. This calculation method was also applied to multiple-lamp reactors. PMID:6405690

  7. Virus Sensitivity Index of UV disinfection.

    PubMed

    Tang, Walter Z; Sillanpää, Mika

    2015-01-01

    A new concept of Virus Sensitivity Index (VSI) is defined as the ratio between the first-order inactivation rate constant of a virus, ki, and that of MS2-phage during UV disinfection, kr. MS2-phage is chosen as the reference virus because it is recommended as a virus indicator during UV reactor design and validation by the US Environmental Protection Agency. VSI has wide applications in research, design, and validation of UV disinfection systems. For example, it can be used to rank the UV disinfection sensitivity of viruses in reference to MS2-phage. There are four major steps in deriving the equation between Hi/Hr and 1/VSI. First, the first-order inactivation rate constants are determined by regression analysis between Log I and fluence required. Second, the inactivation rate constants of MS2-phage are statistically analysed at 3, 4, 5, and 6 Log I levels. Third, different VSI values are obtained from the ki of different viruses dividing by the kr of MS2-phage. Fourth, correlation between Hi/Hr and 1/VSI is analysed by using linear, quadratic, and cubic models. As expected from the theoretical analysis, a linear relationship adequately correlates Hi/Hr and 1/VSI without an intercept. VSI is used to quantitatively predict the UV fluence required for any virus at any log inactivation (Log I). Four equations were developed at 3, 4, 5, and 6 Log I. These equations have been validated using external data which are not used for the virus development. At Log I less than 3, the equation tends to under-predict the required fluence at both low Log I such as 1 and 2 Log I. At Log I greater than 3 Log I, the equation tends to over-predict the fluence required. The reasons for these may very likely be due to the shoulder at the beginning and the tailing at the end of the collimated beam test experiments. At 3 Log I, the error percentage is less than 6%. The VSI is also used to predict inactivation rate constants under two different UV disinfection

  8. UV disinfection system for cabin air

    NASA Astrophysics Data System (ADS)

    Lim, Soojung; Blatchley, Ernest R.

    2009-10-01

    The air of indoor cabin environments is susceptible to contamination by airborne microbial pathogens. A number of air treatment processes are available for inactivation or removal of airborne pathogens; included among these processes is ultraviolet (UV) irradiation. The effectiveness of UV-based processes is known to be determined by the combined effects of UV dose delivery by the reactor and the UV dose-response behavior of the target microbe(s). To date, most UV system designs for air treatment have been based on empirical approaches, often involving crude representations of dose delivery and dose-response behavior. The objective of this research was to illustrate the development of a UV system for disinfection of cabin air based on well-defined methods of reactor and reaction characterization. UV dose-response behavior of a test microorganism was measured using a laboratory (bench-scale) system. Target microorganisms (bacterial spores) were first applied to membrane filters at sub-monolayer coverage. The filters were then transferred to a humidity chamber at fixed relative humidity (RH) and allowed to equilibrate with their surroundings. Microorganisms were then subjected to UV exposure under a collimated beam. The experiment was repeated at RH values ranging from 20% to 100%. UV dose-response behavior was observed to vary with RH. For example, at 100% RH, a UV dose of 20 mJ/cm 2 accomplished 99.7% (2.5 log10 U) of the Bacillus subtilis spore inactivation, whereas 99.94% (3.2 log10 U) inactivation was accomplished at this same UV dose under 20% RH conditions. To determine reactor behavior, UV dose-response behavior was combined with simulated results of computational fluid dynamics (CFD) and radiation intensity field models. This modeling approach allowed estimating the UV dose distribution delivered by the reactor. The advantage of this approach is that simulation of many reactor configurations can be done in a relatively short period of time. Moreover, by

  9. Design and bidding of UV disinfection equipment -- Case study

    SciTech Connect

    Akyurek, M.

    1998-07-01

    Ultraviolet (UV) disinfection systems are being widely considered for application to treated wastewaters, in lieu of conventional chlorination facilities. The number of UV systems operating in the US was approximately 50 in 1984. In 1990 there were over 500 systems, a ten-fold increase. The use of UV disinfection has increased since 1990, and will likely to increase in the future. It is anticipated that as many chlorine disinfection facilities reach their useful life, most of them will be replaced with UV disinfection systems. Several manufacturers offer different UV disinfection equipment. Each offers something different for the designer. There are also different approaches used in estimating the number of lamps needed for the disinfection system. The lack of standardization in determination of the number of lamps for a UV system poses problems for the designer. Such was the case during the design of the disinfection system for the Watertown, SD Wastewater Treatment Plant (WWRP). The purpose of this paper is to present a case study for the design and bidding of UV disinfection equipment.

  10. UV disinfection pilot plant study at the Savannah River Site

    SciTech Connect

    Huffines, R.L.; Beavers, B.A.

    1993-01-01

    An ultraviolet light disinfection system pilot plant was operated at the Savannah River Site Central Shops sanitary wastewater treatment package plant July 14, 1992 through August 13, 1992. The purpose was to determine the effectiveness of ultraviolet light disinfection on the effluent from the small package-type wastewater treatment plants currently used on-site. This pilot plant consisted of a rack of UV lights suspended in a stainless steel channel through which a sidestream of effluent from the treatment plant clarifier was pumped. Fecal coliform analyses were performed on the influent to and effluent from the pilot unit to verify the disinfection process. UV disinfection was highly effective in reducing fecal coliform colonies within NPDES permit limitations even under process upset conditions. The average fecal coliform reduction exceeded 99.7% using ultraviolet light disinfection under normal operating conditions at the package treatment plants.

  11. UV disinfection pilot plant study at the Savannah River Site

    SciTech Connect

    Huffines, R.L.; Beavers, B.A.

    1993-05-01

    An ultraviolet light disinfection system pilot plant was operated at the Savannah River Site Central Shops sanitary wastewater treatment package plant July 14, 1992 through August 13, 1992. The purpose was to determine the effectiveness of ultraviolet light disinfection on the effluent from the small package-type wastewater treatment plants currently used on-site. This pilot plant consisted of a rack of UV lights suspended in a stainless steel channel through which a sidestream of effluent from the treatment plant clarifier was pumped. Fecal coliform analyses were performed on the influent to and effluent from the pilot unit to verify the disinfection process. UV disinfection was highly effective in reducing fecal coliform colonies within NPDES permit limitations even under process upset conditions. The average fecal coliform reduction exceeded 99.7% using ultraviolet light disinfection under normal operating conditions at the package treatment plants.

  12. US EPA Testing of LP & MP UV Disinfection Technologies

    EPA Science Inventory

    Presentation will discuss the ongoing USEPA research on UV disinfection addressing the following objectives: Conservatively predict log inactivation and RED of adenovirus with surrogates; Conduct many (LP=61) UV reactor conditions challenged with Ad2, B. pumilus, and MS2 & conduc...

  13. Tertiary treatment using microfiltration and UV disinfection for water reclamation

    SciTech Connect

    Jolis, D.; Hirano, R.; Pitt, P.

    1999-03-01

    Microfiltration and UV disinfection are two alternative technologies for water reclamation. The results of a pilot study combining these two processes are presented. In addition to producing filtrate turbidites averaging 0.06 nephelometric turbidity units, microfiltration was an effective barrier to pathogens, demonstrating average log reductions of 4.5 for total coliforms and 2.9 for MS2 bacteriophage. Ultraviolet disinfection following microfiltration reliably met the California Wastewater Reclamation Criteria (Title 22) total coliform standard of 2.2 colony-forming units/100 mL at a UV dose of 450 J/m{sup 2}. The MS2 bacteriophage standard, which requires a 5-log reduction, was achieved by microfiltration and a UV dose of 880 J/m{sup 2}. A model of the kinetics of inactivation of MS2 bacteriophage was used in further analysis of disinfection data. The model indicated that considerable backmixing occurred in the pilot UV disinfection unit, and observed UV doses could be reduced with improved hydraulics.

  14. Wastewater disinfection alternatives: chlorine, ozone, peracetic acid, and UV light.

    PubMed

    Mezzanotte, V; Antonelli, M; Citterio, S; Nurizzo, C

    2007-11-01

    Disinfection tests were carried out at pilot scale to compare the disinfection efficiency of ozone, sodium hypochlorite (NaOCl), peracetic acid (PAA), and UV irradiation. Total coliforms, fecal coliforms, and Escherichia coli were monitored as reference microorganisms. Total heterotrophic bacteria (THB) were also enumerated by cytometry. At similar doses, NaOCl was more effective than PAA, and its action was less affected by contact time. The results obtained by ozonation were comparable for total coliforms, fecal coliforms, and E. coli. On the contrary, some differences among the three indicators were observed for NaOCl, PAA, and UV. Differences increased with increasing values of the disinfectant concentration times contact time (C x t) and were probably the result of different initial counts, as total coliforms include fecal coliforms, which include E. coli. The UV irradiation lead to complete E. coli removals, even at low doses (10 to 20 mJ/cm2). Total heterotrophic bacteria appeared to be too wide a group to be a good disinfection indicator; no correlation was found among THB inactivation, dose, and contact time.

  15. Ozone and UV254 radiation for municipal wastewater disinfection.

    PubMed

    Blatchley, Ernest R; Weng, Shihchi; Afifi, Mehrnaz Zare; Chiu, Hsiao-Han; Reichlin, Douglas B; Jousset, Stéphane; Erhardt, Richard S

    2012-11-01

    Bench-scale experiments were conducted with municipal wastewater effluent samples to examine the feasibility of combined application of ozone and ultraviolet (UV) radiation for disinfection. Effluent samples displayed rapid initial ozone demand, which promotes ozone transfer but diminishes disinfection efficacy. Ozone doses up to 10 mg/L yielded only trace quantities of residual ozone; despite the fact that initial ozone demand was never exceeded, quantifiable (though variable) inactivation of E. coli was observed, along with modest improvements of UV transmittance. Results from collimated beam experiments demonstrated that compliance with effluent discharge permit limitations could be achieved consistently with a UV254 dose of 12.4 mJ/cm2 at a pre-ozonation dose of 2 to 3 mg/L. In the absence of pre-ozonation, consistent compliance was observed at a UV dose of 16.5 mJ/cm2. No evidence of synergism between ozone and UV254 radiation was found in the measured inactivation responses of E. coli.

  16. Enhancing disinfection by advanced oxidation under UV irradiation in polyphosphate-containing wastewater flocs.

    PubMed

    Azimi, Y; Allen, D G; Farnood, R R

    2014-05-01

    In this paper, the role of naturally occurring polyphosphate in enhancing the ultraviolet disinfection of wastewater flocs is examined. It was found that polyphosphate, which accumulates naturally within the wastewater flocs in the enhanced biological phosphorus removal process, is capable of producing hydroxyl radicals under UV irradiation and hence causing the photoreactive disinfection of microorganisms embedded within flocs. This phenomenon is likely responsible for the improved UV disinfection of the biological nutrient removal (BNR) effluent compared to that of conventional activated sludge effluent by as much as 1 log. A mathematical model is developed that combines the chemical disinfection by hydroxyl radical formation within flocs, together with the direct inactivation of microorganisms by UV irradiation. The proposed model is able to quantitatively explain the observed improvement in the UV disinfection of the BNR effluents. This study shows that the chemical composition of wastewater flocs could have a significant positive impact on their UV disinfection by inducing the production of oxidative species.

  17. Comparison of methods of enumerating coliforms after UV disinfection.

    PubMed Central

    Qualls, R G; Chang, J C; Ossoff, S F; Johnson, J D

    1984-01-01

    In view of the differences that have been found between the most-probable-number and membrane filtration methods for the recovery of coliforms from chlorinated samples, the survival of total and fecal coliforms in UV-irradiated effluent samples, as tested by the most-probable-number and standard single-step membrane filtration methods, was compared. There were no significant differences in the survival of total and fecal coliforms, as tested by the two methods. In a separate set of experiments comparing total and fecal coliform survival, as tested by the most-probable-number method, only a very small but statistically significant difference of 0.1 log survival units was found. For UV-disinfected wastewater effluents, standard one-step membrane filtration procedures are comparable to standard most-probable-number procedures. PMID:6508284

  18. EVALUATING IN VITRO INFECTIVITY FOR MEASURING UV DISINFECTION OF CRYPTOSPORIDIUM PARVUM OOCYSTS IN FINISHED WATER

    EPA Science Inventory

    UV technology to inactivate Cryptosporidium parvum oocysts has become well established in the US. The challenge now is to effectively demonstrate UV reactor performance and disinfection capacity with various finished water matrices and under different operational conditions. In s...

  19. Chemical pretreatment of combined sewer overflows for improved UV disinfection.

    PubMed

    Gibson, J; Farnood, R; Seto, P

    2016-01-01

    The aim of this research was to better understand chemical pre-treatment of combined sewer overflows (CSOs) for subsequent ultraviolet (UV) disinfection. Approximately 200 jar tests were completed. Alum (Al2(S04)3·12H2O) resulted in a higher UV light transmission (UVT), and equivalent total suspended solids (TSS) removal, than ferric chloride (FeCl3). An alum dose of 20 mg/L increased the UVT of the raw CSO from 30 to 60% after settling. The addition of 100 mg/L of alum maximized UVT reaching approximately 85%. Flocculation did not increase UVT. However, it did improve the removal of TSS. Cationic polymers worked quickly compared with metal coagulants, but only reached a UVT of 60%. A high positive charge density on the polymer improved the removal of turbidity when compared with low charge, but did not affect UVT. If the goal is to maximise UVT, a very high alum dose may be preferred. If the goal is to minimize coagulant dose with moderate UV performance, cationic polymer at approximately 3 mg/L is recommended. PMID:26819393

  20. Wastewater disinfection by low-pressure UV and ozone: a design approach based on water quality.

    PubMed

    Savoye, P; Janex, M L; Lazarova, V

    2001-01-01

    Disinfection processes are known to be very sensitive to wastewater quality. This paper discusses the parameters that impact the UV light (UV) and ozone disinfection processes and the related mechanisms based on literature review. Low-pressure UV and ozone technologies were investigated on effluents that covered a wide range of water quality. The results are given in terms of design doses required to meet three major disinfection standards. Both processes were found eligible for the majority of effluents tested. Although cost-effectiveness is usually considered more favourable to UV, the ozone alternative should be examined in cases such as the disinfection of low-quality effluents or large treatment plants. Ozonation was also found capable of meeting the stringent Title 22 standard with no coagulation at a dose of 10 mg/l.

  1. Effectiveness of UV-C light irradiation on disinfection of an eSOS(®) smart toilet evaluated in a temporary settlement in the Philippines.

    PubMed

    Zakaria, Fiona; Harelimana, Bertin; Ćurko, Josip; van de Vossenberg, Jack; Garcia, Hector A; Hooijmans, Christine Maria; Brdjanovic, Damir

    2016-01-01

    Ultraviolet germicidal (short wavelength UV-C) light was studied as surface disinfectant in an Emergency Sanitation Operation System(®) smart toilet to aid to the work of manual cleaning. The UV-C light was installed and regulated as a self-cleaning feature of the toilet, which automatically irradiate after each toilet use. Two experimental phases were conducted i.e. preparatory phase consists of tests under laboratory conditions and field testing phase. The laboratory UV test indicated that irradiation for 10 min with medium-low intensity of 0.15-0.4 W/m(2) could achieve 6.5 log removal of Escherichia coli. Field testing of the toilet under real usage found that UV-C irradiation was capable to inactivate total coliform at toilet surfaces within 167-cm distance from the UV-C lamp (UV-C dose between 1.88 and 2.74 mW). UV-C irradiation is most effective with the support of effective manual cleaning. Application of UV-C for surface disinfection in emergency toilets could potentially reduce public health risks. PMID:27666295

  2. Effectiveness of UV-C light irradiation on disinfection of an eSOS(®) smart toilet evaluated in a temporary settlement in the Philippines.

    PubMed

    Zakaria, Fiona; Harelimana, Bertin; Ćurko, Josip; van de Vossenberg, Jack; Garcia, Hector A; Hooijmans, Christine Maria; Brdjanovic, Damir

    2016-01-01

    Ultraviolet germicidal (short wavelength UV-C) light was studied as surface disinfectant in an Emergency Sanitation Operation System(®) smart toilet to aid to the work of manual cleaning. The UV-C light was installed and regulated as a self-cleaning feature of the toilet, which automatically irradiate after each toilet use. Two experimental phases were conducted i.e. preparatory phase consists of tests under laboratory conditions and field testing phase. The laboratory UV test indicated that irradiation for 10 min with medium-low intensity of 0.15-0.4 W/m(2) could achieve 6.5 log removal of Escherichia coli. Field testing of the toilet under real usage found that UV-C irradiation was capable to inactivate total coliform at toilet surfaces within 167-cm distance from the UV-C lamp (UV-C dose between 1.88 and 2.74 mW). UV-C irradiation is most effective with the support of effective manual cleaning. Application of UV-C for surface disinfection in emergency toilets could potentially reduce public health risks.

  3. Feasibility of the silver-UV process for drinking water disinfection.

    PubMed

    Butkus, Michael A; Talbot, Mark; Labare, Michael P

    2005-12-01

    A synergistic effect between cationic silver and UV radiation (silver-UV disinfection) has been observed that can appreciably enhance inactivation of viruses. The purpose of this work was to assess the feasibility of this technique for drinking water disinfection and evaluate the effects of selected impurities, found in fresh water, and common parameters on inactivation of the coliphage MS-2 with the silver-UV process. Turbidity (kaolin), calcium hardness, carbonate alkalinity, and pH did not significantly degrade inactivation. Inactivation was reduced in the presence of chloride, at concentrations greater than 30 mg/L, and in water samples with UV-254 absorbance values greater than ca. 0.1 cm(-1). Inactivation of MS-2 with silver-UV disinfection was also reduced at high phosphate concentrations (above ca. 5 mM). Silver-UV inactivation of MS-2 increased with increases in temperature between 10 and 20 degrees C. Silver-UV inactivation of MS-2 was increased by greater than 1-log over UV alone, in two untreated fresh water sources, which indicates that silver-UV may be a viable treatment technology. An assessment of operation and management costs suggests that an increase in inactivation of MS-2 with silver-UV disinfection could be economically beneficial.

  4. Modeling and kinetic characterization of wastewater disinfection using chlorine and UV irradiation.

    PubMed

    Mounaouer, Brahmi; Abdennaceur, Hassen

    2016-10-01

    Sewage disinfection has the primary objective of inactivating pathogenic organisms to prevent the dissemination of waterborne diseases. This study analyzed individual disinfection, with chlorine alone, ultraviolet radiation alone, and a combined disinfection process (chlorine-UV radiation). Pseudomonas aeruginosa ATCC 15442, Escherichia coli ATCC 11229, Salmonella typhi ATCC 14028, and Clostridium perfringens were selected to evaluate the efficiency of different disinfection processes. The aim of the present study was to characterize the kinetics of chlorine (as NaHOCl) consumption, to evaluate responses of these bacterial species to the chlorination, the ultraviolet (UV) radiation, and the chlorine/UV disinfection processes in secondary wastewater using a batch laboratory reactor. Another target of this work was to study the modeling of the kinetic of water disinfection by chlorination and/or UV irradiation. Two kinetic models (Chick-Watson and Hom) were tested as to ability to scale disinfection of these bacterial species by different ultraviolet and/or chlorine doses. The results of the kinetics of chlorine consumption showed that monochloramines and trichloramines were the most important forms of residual chlorine as compared to free chlorine and dichloramines. The kinetics of inactivation of all examined bacterial strains showed that the application of the model of Hom in its original form was not representative of this kinetics of inactivation. Modification of this model, considering an initial decline of bacteria during the contact of water with chlorine, improved the results of the model. By the same, results revealed that the involved processes of UV irradiation were too complex to be approached by a simplified formulation, even in the case of specific strains of microorganisms and the use of nearly constant UV radiation intensity. In fact, the results have pointed out that the application of the Chick-Watson law is known to be inadequate to describe

  5. Modeling and kinetic characterization of wastewater disinfection using chlorine and UV irradiation.

    PubMed

    Mounaouer, Brahmi; Abdennaceur, Hassen

    2016-10-01

    Sewage disinfection has the primary objective of inactivating pathogenic organisms to prevent the dissemination of waterborne diseases. This study analyzed individual disinfection, with chlorine alone, ultraviolet radiation alone, and a combined disinfection process (chlorine-UV radiation). Pseudomonas aeruginosa ATCC 15442, Escherichia coli ATCC 11229, Salmonella typhi ATCC 14028, and Clostridium perfringens were selected to evaluate the efficiency of different disinfection processes. The aim of the present study was to characterize the kinetics of chlorine (as NaHOCl) consumption, to evaluate responses of these bacterial species to the chlorination, the ultraviolet (UV) radiation, and the chlorine/UV disinfection processes in secondary wastewater using a batch laboratory reactor. Another target of this work was to study the modeling of the kinetic of water disinfection by chlorination and/or UV irradiation. Two kinetic models (Chick-Watson and Hom) were tested as to ability to scale disinfection of these bacterial species by different ultraviolet and/or chlorine doses. The results of the kinetics of chlorine consumption showed that monochloramines and trichloramines were the most important forms of residual chlorine as compared to free chlorine and dichloramines. The kinetics of inactivation of all examined bacterial strains showed that the application of the model of Hom in its original form was not representative of this kinetics of inactivation. Modification of this model, considering an initial decline of bacteria during the contact of water with chlorine, improved the results of the model. By the same, results revealed that the involved processes of UV irradiation were too complex to be approached by a simplified formulation, even in the case of specific strains of microorganisms and the use of nearly constant UV radiation intensity. In fact, the results have pointed out that the application of the Chick-Watson law is known to be inadequate to describe

  6. Disinfection of a wastewater flow treated by advanced primary treatment using O₃, UV and O₃/UV combinations.

    PubMed

    Bustos, Yaneth A; Vaca, Mabel; López, Raymundo; Torres, Luis G

    2010-11-01

    This study was conducted to evaluate the ozone, UV and O₃/UV processes for the reuse of sewage treatment plant effluent (Universidad Autonoma Metropolitana Azcapotzalco wastewater treatment plant). The ozone/UV process was compared to individual ozone and the UV processes and control parameters were total and fecal coliforms. Different ozone concentrations (6-12 mg O₃/min) and different UV fluencies (6.7-20.12 mJ/cm²) were tested. It is possible to conclude than none of the processes achieved the disinfection levels required to comply with the Mexican standard NOM-003-SEMARNAT-1997. The continuous ozone process offered the lower total and fecal coliforms reductions, while UV light resulted a disinfection agent with higher germicide power than ozone. The maximum logarithmic reduction achieved due to the combined ozone/UV process was of 2.04 for fecal coliforms and of 2.17 for total coliforms. The next 8 combinations showed lower removal efficiencies, but always higher than those obtained with the single ozone or UV processes. The ozone/UV process was highly effective for the disinfection and a synergistic effect was observed.

  7. Application of ultraviolet light-emitting diodes (UV-LEDs) for water disinfection: A review.

    PubMed

    Song, Kai; Mohseni, Madjid; Taghipour, Fariborz

    2016-05-01

    Ultraviolet (UV) disinfection is an effective technology for the inactivation of pathogens in water and is of growing interest for industrial application. A new UV source - ultraviolet light-emitting diode (UV-LED) - has emerged in the past decade with a number of advantages compared to traditional UV mercury lamps. This promising alternative raises great interest in the research on application of UV-LEDs for water treatment. Studies on UV-LED water disinfection have increased during the past few years. This article presents a comprehensive review of recent studies on UV-LEDs with various wavelengths for the inactivation of different microorganisms. Many inconsistent and incomparable data were found from published studies, which underscores the importance of establishing a standard protocol for studying UV-LED inactivation of microorganisms. Different UV sensitivities to UV-LEDs and traditional UV lamps were observed in the literature for some microorganisms, which requires further investigation for a better understanding of microorganism response to UV-LEDs. The unique aspects of UV-LEDs improve inactivation effectiveness by applying LED special features, such as multiple wavelengths and pulsed illumination; however, more studies are needed to investigate the influencing factors and mechanisms. The special features of UV-LEDs offer the flexibility of novel reactor designs for a broad application of UV-LED reactors.

  8. Feasibility study of UV disinfection for agricultural reuse of secondary level effluent in Korea.

    PubMed

    Yoon, Chun G; Chung, Kwang-Wuk; Ham, Jong-Hwa; Jeon, Ji-Hong

    2004-01-01

    A pilot study was performed to examine the feasibility of UV disinfection for agricultural reuse of reclaimed water. The effluent from the bio-filter of a 16-unit apartment was used as input to the flow-through type UV disinfection system, with average suspended solid (SS) and biological oxygen demand (BOD) concentrations of 3.4 and 5.9 mg/L, respectively, and a mean level of total coliforms in the range of 1.5 x 10(4) MPN/100 mL. UV disinfection was found to be effective, in that it reduced mean concentration of indicator microorganisms (total coliform [TC], fecal coliform [FC], and E. coli) to less than 100 MPN/ 100 mL within 60s exposure using 17, 25, and 40 W lamps. The microorganisms often exceeded 200 MPN/100 mL with 17 and 25W lamps, but were completely removed with 40W lamp in one cylindrical chamber. Disinfection with two chambers in series demonstrated complete removal for all the experiments. About 30 mW x s/cm2 was thought to be adequate for the disinfection of secondary effluent to keep the suggested bacterial standards of 100 MPN FC/100 mL for agricultural reuse. Water quality effect on the UV efficiency was not apparent within the experimental conditions. Statistical analysis showed that the removal rates of TC, FC, and E. coli did not significantly vary with turbidity, dissolved organic matter (DOM), or SS concentrations (p = 0.05). Photo-reactivation problems after UV disinfection might be a lesser concern in agricultural reuse than for other uses, due to exposure of water to solar radiation and resulting inactivation. Overall, UV disinfection of effluent from secondary level wastewater treatment plants in Korea was thought to be an effective and feasible alternative for agricultural reuse, and thus it is strongly recommended.

  9. Use of Clinical UV Chamber to Disinfect Dental Impressions: A Comparative Study

    PubMed Central

    Sharma, Sakshi; Kumar, Varun; Gupta, Neelu

    2015-01-01

    Introduction Dental impressions are potential source of infection in a prosthodontic practice. Risk of transmission of infection through saliva, blood etc is considered as hazard for both dentist as well as dental auxiliary staff. A number of methods are currently employed for disinfecting the impressions which are technique sensitive and time consuming. This study focuses on disinfecting impression using dental UV chamber which is commonly employed for storing sterilized instruments. Aim The aim of this invitro study was to evaluate the use of clinical UV chamber to disinfect various impression materials at different time intervals and its comparison with 2% glutaraldehyde using standard immersion technique. Materials and Methods Total sample size of 180 specimens was taken from three different impression materials. The impressions were made from 30 dentulous subjects. A total of ten impressions were made for each impression material i.e. alginate, addition silicone and polyether impression material. Six punch samples were taken from each impression. Out of 6 punch sample, one was kept as control, second was disinfected by immersing in freshly prepared 2% glutaraldehyde solution for 10 minutes and remaining four were exposed to UV rays for 3 minutes, 6 minutes, 10 minutes and 15 minutes using dental UV chamber. Amount of disinfection achieved was evaluated by counting the colonies over the culture plates with the help of digital colony. Results The results showed that the mean CFUs for alginate were found to be i.e. 11797.40 ± 5989.73 (mean ± SD). The mean CFUs for addition silicone impression material was found 7095.40 with a standard deviation of 4268.83 and the mean CFUs for polyether impression material was found to be 2168.92 ± 1676 (mean ± SD). Conclusion For alginate and addition silicone impression material, disinfection was achieved on exposure to UV rays for a period of 10 minutes. However, for polyether impression material 3 minutes of exposure to

  10. IDENTIFICATION OF TI02/UV DISINFECTION BYPRODUCTS IN DRINKING WATER

    EPA Science Inventory

    Due to concern over the presence of trihalomethanes (THMs) and other chlorinated byproducts in chlorinated drinking water, alternative disinfection methods are being explored. One of the alternative treatment methods currently being evaluated for potential use with small systems ...

  11. Action spectra for validation of pathogen disinfection in medium-pressure ultraviolet (UV) systems.

    PubMed

    Beck, Sara E; Wright, Harold B; Hargy, Thomas M; Larason, Thomas C; Linden, Karl G

    2015-03-01

    Ultraviolet (UV) reactors used for disinfecting water and wastewater must be validated and monitored over time. The validation process requires understanding the photochemical properties of the pathogens of concern and the challenge microorganisms used to represent them. Specifically for polychromatic UV systems, the organisms' dose responses to UV light and their sensitivity across the UV spectrum must be known. This research measured the UV spectral sensitivity, called action spectra, of Cryptosporidium parvum, and MS2, T1UV, Q Beta, T7, and T7m Coliphages, as well as Bacillus pumilus spores. A tunable laser from the National Institute of Standards and Technology was used to isolate single UV wavelengths at 10 nm intervals between 210 and 290 nm. Above 240 nm, all bacteria and viruses tested exhibited a relative peak sensitivity between 260 and 270 nm. Of the coliphage, MS2 exhibited the highest relative sensitivity below 240 nm, relative to its sensitivity at 254 nm, followed by Q Beta, T1UV, T7m and T7 coliphage. B. pumilus spores were more sensitive to UV light at 220 nm than any of the coliphage. These spectra are required for calculating action spectra correction factors for medium pressure UV system validation, for matching appropriate challenge microorganisms to pathogens, and for improving UV dose monitoring. Additionally, understanding the dose response of these organisms at multiple wavelengths can improve polychromatic UV dose calculations and enable prediction of pathogen inactivation from wavelength-specific disinfection technologies such as UV light emitting diodes (LEDs).

  12. Action spectra for validation of pathogen disinfection in medium-pressure ultraviolet (UV) systems.

    PubMed

    Beck, Sara E; Wright, Harold B; Hargy, Thomas M; Larason, Thomas C; Linden, Karl G

    2015-03-01

    Ultraviolet (UV) reactors used for disinfecting water and wastewater must be validated and monitored over time. The validation process requires understanding the photochemical properties of the pathogens of concern and the challenge microorganisms used to represent them. Specifically for polychromatic UV systems, the organisms' dose responses to UV light and their sensitivity across the UV spectrum must be known. This research measured the UV spectral sensitivity, called action spectra, of Cryptosporidium parvum, and MS2, T1UV, Q Beta, T7, and T7m Coliphages, as well as Bacillus pumilus spores. A tunable laser from the National Institute of Standards and Technology was used to isolate single UV wavelengths at 10 nm intervals between 210 and 290 nm. Above 240 nm, all bacteria and viruses tested exhibited a relative peak sensitivity between 260 and 270 nm. Of the coliphage, MS2 exhibited the highest relative sensitivity below 240 nm, relative to its sensitivity at 254 nm, followed by Q Beta, T1UV, T7m and T7 coliphage. B. pumilus spores were more sensitive to UV light at 220 nm than any of the coliphage. These spectra are required for calculating action spectra correction factors for medium pressure UV system validation, for matching appropriate challenge microorganisms to pathogens, and for improving UV dose monitoring. Additionally, understanding the dose response of these organisms at multiple wavelengths can improve polychromatic UV dose calculations and enable prediction of pathogen inactivation from wavelength-specific disinfection technologies such as UV light emitting diodes (LEDs). PMID:25506761

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

    PubMed

    Schmidtlein, F; Lübken, M; Grote, I; Orth, H; Wichern, M

    2015-01-01

    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 effluent revealed a total log10 inactivation of 1.8 units and the small sample of microstrained inflow a total log10 inactivation of 3.2, with an applied UV-254 fluence of 84 and 253 J/m², respectively. Maximum net photoreactivation for secondary effluent and microstrained inflow was in the order of 1.2 log10 and 0.37 log10 units, respectively, for both sample sizes. However, significantly faster photoreactivation performance was generally determined for small sample volumes. The photoreactivation processes were completely compensated for by solar disinfection within a 120 min exposure time. Solar disinfection processes were negligible in the larger sample volumes of microstrained inflow. For municipal wastewater treatment systems with open channel effluents, it is essential to take into consideration the dependence of solar UV-365 fluence rate on water depth and wastewater characteristics.

  14. Sequential water disinfection using UV irradiation and iodination for long-term space missions

    NASA Astrophysics Data System (ADS)

    Pennell, Kelly

    As part of the NASA Specialized Center of Research and Training for Advanced Life Support (NSCORT-ALS), a disinfection process, which uses ultraviolet (UV) radiation as the primary disinfectant and iodine as the secondary disinfectant, was investigated. The purpose of this research was to support NASA's goal of long-term space missions to destinations such as Mars. Long-term space missions typically refer to missions with durations of one (1) to five (5) years. For a hypothetical mission to Mars, the length of the mission is estimated to be 600 days. All of the items required for survival of the six person crew would need to be readily available during the mission, including safe potable water. Due to cost and logistical considerations associated with supplying the crew with earth-based potable water for the entire mission duration, closed-loop water treatment processes, in which a finite amount of water is continuously used and re-used, are being considered. Closed-loop treatment systems are comprised of many individual processes. The subject research is focused on the water disinfection process using ultraviolet (UV) radiation as the primary disinfectant and a chemical disinfectant (iodine) as the residual disinfectant. The four main research objectives completed as part of this research are summarized below. (1) Developed a tool that allowed iodine species and concentrations to be predicted based on system characteristics, such as pH and redox potential. (2) Investigated the disinfection efficacy of UV radiation and iodine using a challenge microorganism (Bacillus subtilis spores). Effort was placed on characterizing the response of B. subtilis spores to sequential disinfection (i.e. UV then iodine). Inactivation models were developed to describe the inactivation kinetics. (3) Evaluated a chemical actinometer to monitor the minimum dose within a UV reactor. A continuous-form irradiance field model was developed to estimate the output of a cylindrical non

  15. Disinfection of Spacecraft Potable Water Systems by Photocatalytic Oxidation Using UV-A Light Emitting Diodes

    NASA Technical Reports Server (NTRS)

    Birmele, Michele N.; O'Neal, Jeremy A.; Roberts, Michael S.

    2011-01-01

    Ultraviolet (UV) light has long been used in terrestrial water treatment systems for photodisinfection and the removal of organic compounds by several processes including photoadsorption, photolysis, and photocatalytic oxidation/reduction. Despite its effectiveness for water treatment, UV has not been explored for spacecraft applications because of concerns about the safety and reliability of mercury-containing UV lamps. However, recent advances in ultraviolet light emitting diodes (UV LEDs) have enabled the utilization of nanomaterials that possess the appropriate optical properties for the manufacture of LEDs capable of producing monochromatic light at germicidal wavelengths. This report describes the testing of a commercial-off-the-shelf, high power Nichia UV-A LED (250mW A365nnJ for the excitation of titanium dioxide as a point-of-use (POD) disinfection device in a potable water system. The combination of an immobilized, high surface area photocatalyst with a UV-A LED is promising for potable water system disinfection since toxic chemicals and resupply requirements are reduced. No additional consumables like chemical biocides, absorption columns, or filters are required to disinfect and/or remove potentially toxic disinfectants from the potable water prior to use. Experiments were conducted in a static test stand consisting of a polypropylene microtiter plate containing 3mm glass balls coated with titanium dioxide. Wells filled with water were exposed to ultraviolet light from an actively-cooled UV-A LED positioned above each well and inoculated with six individual challenge microorganisms recovered from the International Space Station (ISS): Burkholderia cepacia, Cupriavidus metallidurans, Methylobacterium fujisawaense, Pseudomonas aeruginosa, Sphingomonas paucimobilis and Wautersia basilensis. Exposure to the Nichia UV-A LED with photocatalytic oxidation resulted in a complete (>7-log) reduction of each challenge bacteria population in <180 minutes of contact

  16. UV disinfection induces a VBNC state in Escherichia coli and Pseudomonas aeruginosa.

    PubMed

    Zhang, Shenghua; Ye, Chengsong; Lin, Huirong; Lv, Lu; Yu, Xin

    2015-02-01

    The occurrence of a viable but nonculturable (VBNC) state in bacteria may dramatically underestimate the health risks associated with drinking water. Therefore, the potential for UV treatment to induce a VBNC state in Escherichia coli and Pseudomonas aeruginosa was investigated. UV disinfection effectively reduced the culturability of E. coli and P. aeruginosa, with the destruction of nucleic acids demonstrated using gadA long gene fragment qPCR amplification. Following UV radiation, copy numbers for the high transcriptional levels of the 16S rRNA gene varied insignificantly in both strains, confirming results from plate counting assays indicating that VBNC states were induced in both strains. Furthermore, the virulence genes gadA and oprL remained highly expressed, suggesting that the VBNC bacteria still displayed pathogenicity. Propidium monoazide qPCR indicated that cell membranes remained intact even at a UV dose of 300 mJ/cm(2). The RT-qPCR results after UV and chlorine treatments in E. coli were significantly different (8.41 and 5.59 log units, respectively), further confirming the induction of VBNC bacteria induced by UV radiation. Finally, resuscitation was achieved, with E. coli showing greater resuscitation ability than P. aeruginosa. These results systematically revealed the potential health risks of UV disinfection and strongly suggest a combined disinfection strategy.

  17. Comparative disinfection efficiency of pulsed and continuous-wave UV irradiation technologies.

    PubMed

    Bohrerova, Zuzana; Shemer, Hilla; Lantis, Robert; Impellitteri, Christopher A; Linden, Karl G

    2008-06-01

    Pulsed UV (PUV) is a novel UV irradiation system that is a non-mercury lamp-based alternative to currently used continuous-wave systems for water disinfection. PUV polychromatic irradiation disinfection efficiency was compared to that from continuous-wave monochromatic low-pressure (LP) and polychromatic medium-pressure (MP) UV systems, using two types of actinometry (ferrioxalate and iodide-iodate) and an absolute spectral emission method for fluence measurement. All three methods were in good agreement. Once accurate and reliable methods for fluence measurement were established, the inactivation of Escherichia coli and pathogen surrogates phage T4 and T7 were investigated under each technology. Inactivation was significantly faster using PUV irradiation compared to LP or MP UV lamps at equivalent fluence levels. A significant fraction of the enhanced PUV inactivation efficiency was due to wavelengths greater than 295 nm. PMID:18460414

  18. Limnoithona sinensis as refuge for bacteria: protection from UV radiation and chlorine disinfection in drinking water treatment.

    PubMed

    Lin, Tao; Cai, Bo; Chen, Wei

    2014-11-01

    In this study, we tested the potential of Limnoithona sinensis to provide its attached bacteria refuge against disinfection. The experimental results indicated that in water devoid of zooplankton, both UV radiation and chlorine disinfection significantly decreased the viability of free-living bacteria. In the presence of L. sinensis, however, the attached bacteria could survive and rapidly recover from disinfection. This demonstrated that L. sinensis provided protection from external damage to various aquatic bacteria that were attached to its body. The surviving bacteria remained on L. sinensis after disinfection exposure, which enabled a rapid increase in the bacterial population followed by their subsequent release into the surrounding water. Compared with UV radiation, chlorine disinfection was more effective in terms of inactivating attached bacteria. Both UV radiation and chlorine disinfection had little effect in terms of preventing the spread of undesirable bacteria, due to the incomplete inactivation of the bacteria associated with L. sinensis.

  19. MONITORING THE EFFECTIVENESS OF UV DISINFECTION OF AEROMONAS SPP. USING SELECTIVE AND NON-SELECTIVE MEDIA

    EPA Science Inventory

    This research was initiated to determine the sensitivity of Aeromonas spp. to ultraviolet (UV) disinfection. Aeromonas hydrophila is a contaminant listed on the USEPA's 1998 CCL. Three different Aeromonas spp. (A. hydrophila, A. sobria and A. caviae) were tested using membrane fi...

  20. Determining Resistance of Toxoplasma gondii Oocysts to UV Disinfection Using Cell Culture and a Mouse Bioassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of UV exposure on Toxoplasma gondii oocysts has not been completely defined for use in water disinfection. This study evaluated irradiated oocysts by three assays: a SCID mouse biassay, an in vitro T. gondii oocyst plaque assay (TOP-assay), and a quantitative reverse-transcriptase real-t...

  1. Non-PRASA Drinking Water Research on UV Disinfection in Puerto Rico

    EPA Science Inventory

    The U.S. EPA and InterAmerican University of San German worked with water treatment operators from Patillas, Puerto Rico on the installation, training and testing of pretreatment/UV disinfection systems in the communities of La Sofia and Apeadero. This presentation provides path...

  2. Modeling of secondary treated wastewater disinfection by UV irradiation: effects of suspended solids content.

    PubMed

    Brahmi, Mounaouer; Belhadi, Noureddine Hamed; Hamdi, Helmi; Hassen, Abdennaceur

    2010-01-01

    This work aimed to study UV-resistant strains of Pseudomonas aeruginosa, to propose a formulation of the kinetics of secondary treated wastewater disinfection and to underline the influence of suspended solids on the inactivation kinetics of these strains. Some investigations were carried out for the validation of some simulation models, from the simplest, the kinetics model of Chick-Watson reduced to first order, to rather complex models such as multi-kinetic and Collins-Selleck models. Results revealed that the involved processes of UV irradiation were too complex to be approached by a simplified formulation, even in the case of specific strains of microorganisms and the use of nearly constant UV radiation intensity. In fact, the application of Chick-Watson model in its original form is not representative of the kinetics of UV disinfection. Modification, taking into account the speed change during the disinfection process, has not significantly improved results. On the other hand, the application of Collins-Selleck model demonstrates that it was necessary to exceed a least dose of critical radiation to start the process of inactivation. To better explain the process of inactivation, we have assumed that the action of disinfectant on the survival of lonely microorganisms is faster than its action on suspended solids protected or agglomerated to each others. We can assume in this case the existence of two inactivation kinetics during the processes (parallel and independent) of the first-order. For this reason, the application of a new kinetic model by introducing a third factor reflecting the influence of suspended solids in water on disinfection kinetics appeared to be determinant for modeling UV inactivation of P. aeruginosa in secondary treated wastewater.

  3. Secondary formation of disinfection by-products by UV treatment of swimming pool water.

    PubMed

    Spiliotopoulou, Aikaterini; Hansen, Kamilla M S; Andersen, Henrik R

    2015-07-01

    Formation of disinfection by-products (DBPs) during experimental UV treatment of pool water has previously been reported with little concurrence between laboratory studies, field studies and research groups. In the current study, changes in concentration of seven out of eleven investigated volatile DBPs were observed in experiments using medium pressure UV treatment, with and without chlorine and after post-UV chlorination. Results showed that post-UV chlorine consumption increased, dose-dependently, with UV treatment dose. A clear absence of trihalomethane formation by UV and UV with chlorine was observed, while small yet statistically significant increases in dichloroacetonitrile and dichloropropanone concentrations were detected. Results indicate that post-UV chlorination clearly induced secondary formation of several DBPs. However, the formation of total trihalomethanes was no greater than what could be replicated by performing the DBP formation assay with higher chlorine concentrations to simulate extended chlorination. Post-UV chlorination of water from a swimming pool that continuously uses UV treatment to control combined chlorine could not induce secondary formation for most DBPs. Concurrence for induction of trihalomethanes was identified between post-UV chlorination treatments and simulated extended chlorination time treatment. Trihalomethanes could not be induced by UV treatment of water from a continuously UV treated pool. This indicates that literature reports of experimentally induced trihalomethane formation by UV may be a result of kinetic increase in formation by UV. However, this does not imply that higher trihalomethane concentrations would occur in pools that apply continuous UV treatment. The bromine fraction of halogens in formed trihalomethanes increased with UV dose. This indicates that UV removes bromine atoms from larger molecules that participate in trihalomethane production during post-UV chlorination. Additionally, no significant

  4. Synergistic effect of the sequential use of UV irradiation and chlorine to disinfect reclaimed water.

    PubMed

    Wang, Xiujuan; Hu, Xuexiang; Wang, Haibo; Hu, Chun

    2012-03-15

    The effectiveness of UV and chlorination, used individually and sequentially, was investigated in killing pathogenic microorganisms and inhibiting the formation of disinfection by-products in two different municipal wastewaters for the source water of reclaimed water, which were from a microfilter (W1) and membrane bioreactor (W2) respectively. Heterotrophic plate count (HPC), total bacteria count (TBC), and total coliform (TC) were selected to evaluate the efficiency of different disinfection processes. UV inactivation of the three bacteria followed first-order kinetics in W1 wastewater, but in W2 wastewater, the UV dose-response curve trailed beyond approximately 10 mJ/cm2 UV. The higher number of particles in the W2 might have protected the bacteria against UV damage, as UV light alone was not effective in killing HPC in W2 wastewater with higher turbidity. However, chlorine was more effective in W2 than in W1 for the three bacteria inactivation owing to the greater formation of inorganic and organic chloramines in W1 wastewater. Complete inactivation of HPC in W1 wastewater required a chlorine dose higher than 5.5 mg/L, whereas 4.5 mg/L chlorine gave the equivalent result in W2 wastewater. In contrast, sequential UV and chlorine treatment produced a synergistic effect in both wastewater systems and was the most effective option for complete removal of all three bacteria. UV disinfection lowered the required chlorine dose in W1, but not in W2, because of the higher chlorine consumption in W2 wastewater. However, UV irradiation decreased total trihalomethane formation during chlorination in both wastewaters.

  5. US EPA's UV Disinfection Technologies Demonstration Study - States Briefing

    EPA Science Inventory

    EPA report and anticipated Journal articles will provide recommendations & guidance based on lessons learned for subsequent UV technology testing and monitoring/control applications of virus inactivation in drinking water.

  6. The regrowth of phytoplankton cultures after UV disinfection.

    PubMed

    Martínez, Lucía F; Mahamud, Manuel M; Lavín, Antonio G; Bueno, Julio L

    2013-02-15

    This study addresses how cultures of three phytoplankton species -Chaetoceros calcitrans, Chlorella autotrophica and Phaeocystis globosa - can recover from the effects of UV-C exposure if the cells are placed in a rich medium. Flow cytometry and pulse amplitude modulation (PAM) were used to determine cell recovery after UV treatment. The recovery of C. calcitrans was complete 9 days after treatment. For C. autotrophica, the recovery was noticeable 5 days after treatment. P. globosa only recovered if the UV dose did not exceed 7.3×10(5) μWs/cm(2). The recovery of the UV-treated cultures introduced to a regrowth medium, compared with the recovery of the irradiated cultures kept in their original environment, had two main characteristics: cell recovery was slower but was more efficient. This pattern of recovery has very important implications for real ballast water management systems because such systems discharge treated water into the environment.

  7. Fungicidal effects of chemical disinfectants, UV light, desiccation and heat on the amphibian chytrid Batrachochytrium dendrobatidis.

    PubMed

    Johnson, Megan L; Berger, Lee; Philips, Lara; Speare, Richard

    2003-12-29

    The efficacy of a number of disinfection treatments was tested on in vitro cultures of the fungus Batrachochytrium dendrobatidis, the causative agent of chytridiomycosis in amphibians. The aim was to evaluate the fungicidal effects of chemical disinfectants, sterilising ultraviolet (UV) light, heat and desiccation, using methods that were feasible for either disinfection in the field, in amphibian husbandry or in the laboratory. The chemical disinfectants tested were: sodium chloride, household bleach (active ingredient: sodium hypochlorite), potassium permanganate, formaldehyde solution, Path-X agricultural disinfectant (active ingredient: didecyl dimethyl ammonium chloride, DDAC), quaternary ammonium compound 128 (DDAC), Dithane, Virkon, ethanol and benzalkonium chloride. In 2 series of experiments using separate isolates of B. dendrobatidis, the fungicidal effect was evaluated for various time periods and at a range of chemical concentrations. The end point measured was death of 100% of zoospores and zoosporangia. Nearly all chemical disinfectants resulted in 100%, mortality for at least one of the concentrations tested. However, concentration and time of exposure was critical for most chemicals. Exposure to 70% ethanol, 1 mg Virkon ml(-1) or 1 mg benzalkonium chloride ml(-1) resulted in death of all zoosporangia after 20 s. The most effective products for field use were Path-X and the quaternary ammonium compound 128, which can be used at dilutions containing low levels (e.g. 0.012 or 0.008%, respectively) of the active compound didecyl dimethyl ammonium chloride. Bleach, containing the active ingredient sodium hypochlorite, was effective at concentrations of 1% sodium hypochlorite and above. Cultures did not survive complete drying, which occurred after <3 h at room temperature. B. dendrobatidis was sensitive to heating, and within 4 h at 37 degrees C, 30 min at 47 degrees C and 5 min at 60 degrees C, 100% mortality occurred. UV light (at 1000 mW m(-2) with a

  8. Evaluation of an Innovative Approach to Validation of Ultraviolet (UV) Reactors for Disinfection in Drinking Water Systems

    EPA Science Inventory

    UV disinfection is an effective process for inactivating many microbial pathogens found in source waters with the potential as stand-alone treatment or in combination with other disinfectants. For surface and groundwater sourced drinking water applications, the U.S. Environmental...

  9. [Inactivation and reactivation of antibiotic-resistant bacteria during and after UV disinfection in reclaimed water].

    PubMed

    Huang, Jing-Jing; Tang, Fang; Xi, Jin-Ying; Pang, Yu-Chen; Hu, Hong-Ying

    2014-04-01

    Prevalence of antibiotic-resistant bacteria in wastewater effluents is concerned as an emerging contaminant. To estimate inactivation and reactivation potentials of antibiotic-resistant bacteria by UV disinfection, inactivation and reactivation of penicillin-, ampicillin-, cephalexin-, chloramphenicol-and rifampicin-resistant bacteria in the secondary effluent were studied under different UV doses. The results showed that the inactivation ratios of penicillin-, ampicillin-, cephalexin-and chloramphenicol-resistant bacteria were higher than 4-log, which was closed to that of total heterotrophic bacteria; however, the inactivation ratio of rifampicin-resistant bacteria was lower (3.7-log) under 20 mJ x cm(-2) UV exposure. After 22 h standing incubation, antibiotic-resistant bacteria widely reactivated. The colony forming ability of antibiotic-resistant bacteria was as high as 3-log when exposed to 20 mJ x cm(-2) UV light. Hence, conventional UV dose can not effectively control reactivation of antibiotic-resistant bacteria in reclaimed water by UV disinfection.

  10. Disinfection and oxidation of sewage effluent water using ozone and UV technologies.

    PubMed

    Oh, B S; Park, S J; Jung, Y J; Park, S Y; Kang, J W

    2007-01-01

    This study was aimed at exploring the reclamation of sewage treatment plant effluent water (SEW) as an alternative water resource. For the oxidation of SEW, an ozone-UV system, based on the results of the combined ozone/UV process performed in our previous study, was set up under practical conditions, including a series type, continuous mode, semi-pilot scale operation (1.5 m3/d). As a result, the serial contact of the ozone and UV reactors showed lower CODCr and TOC removal efficiencies. However, these were greatly enhanced by recycling the water flow of the ozone-UV system at 40Q, as a result of the improvements in the transferred ozone dose in the ozone reactor and the contact efficiency between photons and ozone in the UV reactor, which approached that achieved in the combined ozone/UV process. For the disinfection of SEW, carried out in a syringe-type batch reactor, the increase of instantaneous ozone demand (ozone ID) led to a higher inactivation efficiency, an increased UV transmittance due to ozonation, and an enhanced inactivation rate of E. coli in the UV reactor. Additionally, it was concluded that the ozone/UV process could overcome the limitations of the ozone alone and UV alone processes for the reclamation of sewage effluent water.

  11. The potential for optical beam shaping of UV laser sources for mass scale quarantine disinfection applications

    NASA Astrophysics Data System (ADS)

    Lizotte, Todd

    2010-08-01

    Recent events concerning H1N1 "swine flu", have demonstrated to the world the significant potential of rapid increases in death and illness among all age groups and even among the healthy population [1] when a highly infectious influenza virus is introduced. In terms of mass casualties due to a pandemic, preparedness and response planning must be done. One course of action to prevent a pandemic outbreak or reduce the impact of a bioterrorist event is the use of isolation or quarantine facilities. The first level of isolation or quarantine is within the personal residence of the person exposed or infected. In the case where, the specific virus is extremely contagious and its onset of symptoms is rapid and severe, there will be a need for the deployment and setup of larger self contained quarantine facilities. Such facilities are used to house infectious individuals to minimize the exposure of susceptible individuals to contagious individuals, especially when specialized care or treatment is required and during the viral shedding period (5 to 7 days). These types of facilities require non-shared air conditioning, heating and ventilating systems where 100% of air is vented to the outside through a series of disinfection systems and staged filters. Although chemical disinfection is possible, there is a desire to incorporate intense UV radiation as a means to deactivate and disinfect airborne virus within hospital settings and isolated mass scale quarantine facilities. UV radiation is also being considered for disinfection of contaminated surfaces, such as table tops, walls and floors in hospitals and temporary quarantine facilities. In such applications the use of UV bulb technology can create many problems, for instance bulb technology requires numerous bulbs to treat a large volume of air, generates significant heat, uses significant power and does not produce large fluxes of UV light efficiently. This paper provides several methods of creating quarantine level

  12. Infectivity of Giardia duodenalis Cysts from UV Light-Disinfected Wastewater Effluent Using a Nude BALB/c Mouse Model.

    PubMed

    Dos Santos, Luciana Urbano; Alves, Delma Pegolo; Guaraldo, Ana Maria Aparecida; Cantusio Neto, Romeu; Durigan, Mauricio; Franco, Regina Maura Bueno

    2013-01-01

    Giardia duodenalis is a protozoan of public health interest that causes gastroenteritis in humans and other animals. In the city of Campinas in southeast Brazil, giardiasis is endemic, and this pathogen is detected at high concentrations in wastewater effluents, which are potential reservoirs for transmission. The Samambaia wastewater treatment plant (WWTP) in the city of Campinas employs an activated sludge system for sewage treatment and ultraviolet (UV) light for disinfection of effluents. To evaluate this disinfection process with respect to inactivating G. duodenalis cysts, two sample types were investigated: (i) effluent without UV disinfection (EFL) and (ii) effluent with UV disinfection (EFL+UV). Nude immunodeficient BALB/c mice were intragastrically inoculated with a mean dose of 14 cysts of G. duodenalis recovered from effluent from this WWTP, EFL, or EFL+UV. All animals inoculated with G. duodenalis cysts developed the infection, but animals inoculated with UV-exposed cysts released a lower average concentration of cysts in their faeces than animals inoculated with cysts that were not UV disinfected. Trophozoites were also observed in both groups of animals. These findings suggest that G. duodenalis cysts exposed to UV light were damaged but were still able to cause infection.

  13. Infectivity of Giardia duodenalis Cysts from UV Light-Disinfected Wastewater Effluent Using a Nude BALB/c Mouse Model.

    PubMed

    Dos Santos, Luciana Urbano; Alves, Delma Pegolo; Guaraldo, Ana Maria Aparecida; Cantusio Neto, Romeu; Durigan, Mauricio; Franco, Regina Maura Bueno

    2013-01-01

    Giardia duodenalis is a protozoan of public health interest that causes gastroenteritis in humans and other animals. In the city of Campinas in southeast Brazil, giardiasis is endemic, and this pathogen is detected at high concentrations in wastewater effluents, which are potential reservoirs for transmission. The Samambaia wastewater treatment plant (WWTP) in the city of Campinas employs an activated sludge system for sewage treatment and ultraviolet (UV) light for disinfection of effluents. To evaluate this disinfection process with respect to inactivating G. duodenalis cysts, two sample types were investigated: (i) effluent without UV disinfection (EFL) and (ii) effluent with UV disinfection (EFL+UV). Nude immunodeficient BALB/c mice were intragastrically inoculated with a mean dose of 14 cysts of G. duodenalis recovered from effluent from this WWTP, EFL, or EFL+UV. All animals inoculated with G. duodenalis cysts developed the infection, but animals inoculated with UV-exposed cysts released a lower average concentration of cysts in their faeces than animals inoculated with cysts that were not UV disinfected. Trophozoites were also observed in both groups of animals. These findings suggest that G. duodenalis cysts exposed to UV light were damaged but were still able to cause infection. PMID:27335858

  14. Infectivity of Giardia duodenalis Cysts from UV Light-Disinfected Wastewater Effluent Using a Nude BALB/c Mouse Model

    PubMed Central

    dos Santos, Luciana Urbano; Alves, Delma Pegolo; Guaraldo, Ana Maria Aparecida; Cantusio Neto, Romeu; Durigan, Mauricio; Franco, Regina Maura Bueno

    2013-01-01

    Giardia duodenalis is a protozoan of public health interest that causes gastroenteritis in humans and other animals. In the city of Campinas in southeast Brazil, giardiasis is endemic, and this pathogen is detected at high concentrations in wastewater effluents, which are potential reservoirs for transmission. The Samambaia wastewater treatment plant (WWTP) in the city of Campinas employs an activated sludge system for sewage treatment and ultraviolet (UV) light for disinfection of effluents. To evaluate this disinfection process with respect to inactivating G. duodenalis cysts, two sample types were investigated: (i) effluent without UV disinfection (EFL) and (ii) effluent with UV disinfection (EFL+UV). Nude immunodeficient BALB/c mice were intragastrically inoculated with a mean dose of 14 cysts of G. duodenalis recovered from effluent from this WWTP, EFL, or EFL+UV. All animals inoculated with G. duodenalis cysts developed the infection, but animals inoculated with UV-exposed cysts released a lower average concentration of cysts in their faeces than animals inoculated with cysts that were not UV disinfected. Trophozoites were also observed in both groups of animals. These findings suggest that G. duodenalis cysts exposed to UV light were damaged but were still able to cause infection. PMID:27335858

  15. A comparative study of the bactericidal activity and daily disinfection housekeeping surfaces by a new portable pulsed UV radiation device.

    PubMed

    Umezawa, Kazuo; Asai, Satomi; Inokuchi, Sadaki; Miyachi, Hayato

    2012-06-01

    Daily cleaning and disinfecting of non-critical surfaces in the patient-care areas are known to reduce the occurrence of health care-associated infections. However, the conventional means for decontamination of housekeeping surfaces of sites of frequent hand contact such as manual disinfection using ethanol wipes are laborious and time-consuming in daily practice. This study evaluated a newly developed portable pulsed ultraviolet (UV) radiation device for its bactericidal activity in comparison with continuous UV-C, and investigated its effect on the labor burden when implemented in a hospital ward. Pseudomonas aeruginosa, Multidrug-resistant P. aeruginosa, Escherichia coli, Acinetobacter baumannii, Amikacin and Ciprofloxacin-resistant A. baumannii, Staphylococcus aureus, Methicillin-resistant S. aureus and Bacillus cereus were irradiated with pulsed UV or continuous UV-C. Pulsed UV and continuous UV-C required 5 and 30 s of irradiation, respectively, to attain bactericidal activity with more than 2Log growth inhibition of all the species. The use of pulsed UV in daily disinfection of housekeeping surfaces reduced the working hours by half in comparison to manual disinfection using ethanol wipes. The new portable pulsed UV radiation device was proven to have a bactericidal activity against critical nosocomial bacteria, including antimicrobial-resistant bacteria after short irradiation, and was thus found to be practical as a method for disinfecting housekeeping surfaces and decreasing the labor burden.

  16. Effect of ozonation and UV irradiation with direct filtration on disinfection and disinfection by-product precursors in drinking water treatment.

    PubMed

    Amirsardari, Y; Yu, Q; Willams, P

    2001-09-01

    Pilot plant studies were conducted to evaluate the effect of pre-ozonation and ultraviolet irradiation on disinfection, disinfection by-product precursors and water quality in a direct filtration water treatment system. Disinfection parameters including total coliforms, faecal coliforms and heterotrophic plate count were investigated. Total organic carbon (TOC), trihalomethanes (THMs), total organic halides (TOX), filtered water turbidity and colour were also evaluated. It was found that advanced pre-oxidation processes (ozonation and UV irradiation) significantly increase the level of disinfection of raw water. Removal of total trihalomethanes and total organic halides precursors improved with ozonation and UV irradiation, compared to no oxidation treatment in direct filtration and/or in conventional water treatment. All coliforms (total and faecal) were completely destroyed by ozonation alone, and also with ozonation in conjunction with UV irradiation. However, the heterotrophic plate count was not significantly reduced at an ozone residual concentration of 0.1 mg l(-1). This suggests that disinfection efficiency is strongly influenced by competition reactions of organic and inorganic compounds with ozone. Precursors of total trihalomethanes and total organic halides were reduced by 90% and 98%, respectively, with advanced pre-oxidation processes. Water quality parameters were improved by the pre-ozonation and UV irradiation treatment system.

  17. Removal of disinfection by-product precursors with ozone-UV advanced oxidation process.

    PubMed

    Chin, A; Bérubé, P R

    2005-05-01

    The efficacy of using ozone (O3), ultraviolet irradiation (UV) and the combined O3-UV advanced oxidation process (AOP) to remove 2 classes of disinfection by-product (DBP) precursors from raw surface water samples have been evaluated and compared. In particular, trihalomethane and haloacetic acids formation potentials were measured. Laboratory batch scale experiments were carried out as a function of ozone and UV dosage in order to study the removal kinetics. It is concluded that the combined O3-UV AOP is more effective than either the ozone or UV treatment alone. Ozone-UV AOP is capable of mineralizing up to 50% of the total organic carbon from the raw source water at an ozone dose of 0.62+/-0.019 mg O3/mL and a UV dose of 1.61 W s/cm2. In addition, O3-UV AOP can reduce trihalomethane formation potential by roughly 80% and haloacetic acids formation potential by roughly 70% at the same ozone and UV dosage.

  18. Effects of UV light disinfection on antibiotic-resistant coliforms in wastewater effluents

    SciTech Connect

    Meckes, M.C.

    1982-02-01

    Total coliforms and total coliforms resistant to streptomycin, tetracycline, or chloramphenicol were isolated from filtered activated sludge effluents before and after UV light irradiation. Although the UV irradiation effectively disinfected the wastewater effluent, the percentage of the total surviving coliform population resistant to tetracycline or chloramphenicol was significantly higher than the percentage of the total coliform population resistant to those antibiotics before UV irradiation. This finding was attributed to the mechanism of R-factor mediated resistance to tetracycline. No significant difference was noted for the percentage of the surviving total coliform population resistant to streptomycin before or after UV irradiation. Multiple drug resistant to patterns of 300 total coliform isolates revealed that 82% were resistant to two or more antibiotics. Furthermore, 46% of these isolates were capable of transferring antibiotic resistance to a sensitive strain of Escherichia coli.

  19. The assessment of particle association and UV disinfection of wastewater using indigenous spore-forming bacteria.

    PubMed

    Li, Dong; Craik, Stephen A; Smith, Daniel W; Belosevic, Miodrag

    2009-02-01

    Studies have shown that association between particles and coliform bacteria in wastewater influence the inactivation of these microorganisms by ultraviolet (UV) irradiation. This research investigated the potential use of indigenous aerobic spore-forming (ASF) bacteria for studying the particle - microorganism interaction and its effect on UV disinfection of protozoan pathogens, such as Giardia spp. and Cryptosporidium spp., present in effluents from full-scale municipal wastewater treatment plants. The effect of particle - ASF association was determined by homogenizing wastewater effluent samples before and after exposure to controlled UV doses delivered by a bench-scale collimated beam apparatus. Particle association between Bacillus subtilis spores added to wastewater and wastewater particles was also assessed. The results indicate that spores are not significantly associated with wastewater particulate matter and particle association does not significantly affect the inactivation of indigenous spores present in wastewater by UV radiation in this study. PMID:18996557

  20. Effect of UV light disinfection on antibiotic-resistant coliforms in wastewater effluents.

    PubMed Central

    Meckes, M C

    1982-01-01

    Total coliforms and total coliforms resistant to streptomycin, tetracycline, or chloramphenicol were isolated from filtered activated sludge effluents before and after UV light irradiation. Although the UV irradiation effectively disinfected the wastewater effluent, the percentage of the total surviving coliform population resistant to tetracycline or chloramphenicol was significantly higher than the percentage of the total coliform population resistant to those antibiotics before UV irradiation. This finding was attributed to the mechanism of R-factor-mediated resistance to tetracycline. No significant difference was noted for the percentage of the surviving total coliform population resistant to streptomycin before or after UV irradiation. Multiple drug resistance patterns of 300 total coliform isolates revealed that 82% were resistant to two or more antibiotics. Furthermore, 46% of these isolates were capable of transferring antibiotic resistance to a sensitive strain of Escherichia coli. PMID:7059170

  1. The efficacy of UV irradiation in the microbial disinfection of marine mammal water.

    PubMed

    Spotte, S; Buck, J D

    1981-01-01

    A study was made on the efficacy of a commercial ultraviolet (UV) sterilizer in reducing the number of bacteria and yeasts ina saline, closed-system marine mammal complex. UV irradiation was effective in lowering bacterial counts in the effluent of the unit (greater than 75% reduction), but bacteria in more remote parts of the water system reached levels equal to or greater than pre-UV counts. Yeast reduction was considerably less, and a trend similar to that of the bacteria was observed in remote sections of the water system. It is concluded that UV irradiation is of limited value in the disinfection of marine mammal water. Factors contributing to the poor performance of the sterilizer were the long recycle time of the water and lack of a residual effect.

  2. Performance of UV disinfection and the microbial quality of greywater effluent along a reuse system for toilet flushing.

    PubMed

    Friedler, Eran; Gilboa, Yael

    2010-04-01

    This paper examines the microbial quality of treated RBC (Rotating Biological Contactor) and MBR (Membrane Bioreactor) light greywater along a continuous pilot-scale reuse system for toilet flushing, quantifies the efficiency of UV disinfection unit, and evaluates the regrowth potential of selected microorganisms along the system. The UV disinfection unit was found to be very efficient in reducing faecal coliforms and Staphylococcus aureus. On the other hand, its efficiency of inactivation of HPC (Heterotrophic Plate Count) and Pseudomonas aeruginosa was lower. Some regrowth occurred in the reuse system as a result of HPC regrowth which included opportunistic pathogens such as P. aeruginosa. Although the membrane (UF) of the MBR system removed all bacteria from the greywater, bacteria were observed in the reuse system due to "hopping phenomenon." The microbial quality of the disinfected greywater was found to be equal or even better than the microbial quality of "clean" water in toilet bowls flushed with potable water (and used for excretion). Thus, the added health risk associated with reusing the UV-disinfected greywater for toilet flushing (regarding P. aeruginosa and S. aureus), was found to be insignificant. The UV disinfection unit totally removed (100%) the viral indicator (F-RNA phage, host: E. coli F(amp)(+)) injected to the treatment systems simulating transient viral contamination. To conclude, this work contributes to better design of UV disinfection reactors and provides an insight into the long-term behavior of selected microorganisms along on-site greywater reuse systems for toilet flushing.

  3. The role of effluent nitrate in trace organic chemical oxidation during UV disinfection.

    PubMed

    Keen, Olya S; Love, Nancy G; Linden, Karl G

    2012-10-15

    Most conventional biological treatment wastewater treatment plants (WWTPs) contain nitrate in the effluent. Nitrate undergoes photolysis when irradiated with ultraviolet (UV) light in the 200-240 and 300-325 nm wavelength range. In the process of nitrate photolysis, nitrite and hydroxyl radicals are produced. Medium pressure mercury lamps emitting a polychromatic UV spectrum including irradiation below 240 nm are becoming more common for wastewater disinfection. Therefore, nitrified effluent irradiated with polychromatic UV could effectively become a de facto advanced oxidation (hydroxyl radical) treatment process. UV-based advanced oxidation processes commonly rely on addition of hydrogen peroxide in the presence of UV irradiation for production of hydroxyl radicals. This study compares the steady-state concentration of hydroxyl radicals produced by nitrate contained in a conventional WWTP effluent to that produced by typical concentrations of hydrogen peroxide used for advanced oxidation treatment of water. The quantum yield of hydroxyl radical production from nitrate by all pathways was calculated to be 0.24 ± 0.03, and the quantum yield of hydroxyl radicals from nitrite was calculated to be 0.65 ± 0.06. A model was developed that would estimate production of hydroxyl radicals directly from nitrate and water quality parameters. In effluents with >5 mg-N/L of nitrate, the concentration of hydroxyl radicals is comparable to that produced by addition of 10 mg/L of H(2)O(2). Nitrifying wastewater treatment plants utilizing polychromatic UV systems at disinfection dose levels can be expected to achieve up to 30% degradation of some micropollutants by hydroxyl radical oxidation. Increasing UV fluence to levels used during advanced oxidation could achieve over 95% degradation of some compounds. PMID:22819875

  4. Impulse powerful UV-radiation source pumped by the sublight ionization waves for the bacteriological disinfection of water

    NASA Astrophysics Data System (ADS)

    Filiouguine, Igor V.; Kostiouchenko, S. V.; Koudryavtsev, N. N.; Vasilyak, Leonid M.; Yakimenko, A. V.

    1993-11-01

    The bacteriological disinfective action of UV-radiation is well known. The pioneer work on UV-radiation used for bacteriological disinfection of waste water was made in 1910. Because of the high cost and low living time of the UV-radiation sources, the alternative technique for waste water purification by chlorine introducing was spread out. During the second stage of the UV purification development, beginning in approximately 1970, the interest for bacteriological cleaning of water, increased again. Two reasons were responsible for this event: first, the significant improvement of technology and design of UV-bacteriological purificators, and second, recognition of the serious danger of chlorine compounds introduced into water under purification because of the toxicity of these compounds. Further investigations gave excellent results in the creation and industrial applications of UV- bacteriological purificators. Now we can see a rapid development of industrial technology in UV-purification of drinking and waste waters.

  5. Silver nanowire-carbon fiber cloth nanocomposites synthesized by UV curing adhesive for electrochemical point-of-use water disinfection.

    PubMed

    Hong, Xuesen; Wen, Junjie; Xiong, Xuhua; Hu, Yongyou

    2016-07-01

    Novel silver nanowire (AgNW) - carbon fiber cloth (CC) nanocomposites were synthesized by a rapid and facile method. Acting as filter in an electrical gravity filtration device, the AgNW-CC nanocomposites were applied to electrochemical point-of-use water disinfection. AgNW-CC nanocomposites were characterized by FESEM, XRD, and FTIR. Their disinfection performance toward Escherichia coli and bacteriophage MS2 was evaluated by inhibition zone tests, optical density growth curve tests, and flow tests. The results showed that complex 3D AgNW networks with controllable silver release (<100 ppb) were fabricated on CC by using UV curing adhesive. AgNW-CC nanocomposites exhibited excellent intrinsic antibacterial activities against E. coli. The concentration of AgNWs and UV adhesive controlled the released silver and hence led to the change in antibacterial activity. The external electric field significantly enhanced the disinfection efficiency of AgNW-CC nanocomposites. Over 99.999% removal of E. coli and MS2 could be achieved. More complex AgNW networks contributed to higher disinfection efficiency under 10 V and 10(6) CFU (PFU) mL(-1) of microorganism. UV adhesive could keep the disinfection performance from being affected by flow rate. The convenient synthesis and outstanding disinfection performance offer AgNW-CC nanocomposites opportunities in the application of electrochemical point-of-use drinking water disinfection. PMID:27085313

  6. Silver nanowire-carbon fiber cloth nanocomposites synthesized by UV curing adhesive for electrochemical point-of-use water disinfection.

    PubMed

    Hong, Xuesen; Wen, Junjie; Xiong, Xuhua; Hu, Yongyou

    2016-07-01

    Novel silver nanowire (AgNW) - carbon fiber cloth (CC) nanocomposites were synthesized by a rapid and facile method. Acting as filter in an electrical gravity filtration device, the AgNW-CC nanocomposites were applied to electrochemical point-of-use water disinfection. AgNW-CC nanocomposites were characterized by FESEM, XRD, and FTIR. Their disinfection performance toward Escherichia coli and bacteriophage MS2 was evaluated by inhibition zone tests, optical density growth curve tests, and flow tests. The results showed that complex 3D AgNW networks with controllable silver release (<100 ppb) were fabricated on CC by using UV curing adhesive. AgNW-CC nanocomposites exhibited excellent intrinsic antibacterial activities against E. coli. The concentration of AgNWs and UV adhesive controlled the released silver and hence led to the change in antibacterial activity. The external electric field significantly enhanced the disinfection efficiency of AgNW-CC nanocomposites. Over 99.999% removal of E. coli and MS2 could be achieved. More complex AgNW networks contributed to higher disinfection efficiency under 10 V and 10(6) CFU (PFU) mL(-1) of microorganism. UV adhesive could keep the disinfection performance from being affected by flow rate. The convenient synthesis and outstanding disinfection performance offer AgNW-CC nanocomposites opportunities in the application of electrochemical point-of-use drinking water disinfection.

  7. [Analysis of UV-visible absorption spectrum on the decolorization of industrial wastewater by disinfection].

    PubMed

    Huang, Xin; Wang, Long-Yong; Gao, Nai-Yun; Li, Wei-Guo

    2012-10-01

    The UV-Visible absorption spectrum of industrial wastewater was explored to introduce a substituting method determining the color of water, and to compare the decolorization efficacy of different disinfectants. The results show that the visible absorption spectrum(350-600 nm), instead of ultraviolet absorption spectrum, should be applied to characterize the color of wastewater. There is a good correlation between the features of visible absorption spectrum and the true color of wastewater. Both ozone and chlorine dioxide has a better decolorization performance than chlorine. However, the color of chlorine dioxide itself has a negative effect on decolorization. The changes in the features of visible absorption spectrum effectively reflect the variations in the color of wastewater after disinfection.

  8. ENVIRONMENTAL TECHNOLOGY VERIFICATION: JOINT (NSF-EPA) VERIFICATION STATEMENT AND REPORT: UV DISINFECTION FOR REUSE APPLICATIONS, ONDEO DEGREMONT, INC., AQUARAY® 40 HO VLS DISINFECTION SYSTEM

    EPA Science Inventory

    Verification testing of the Ondeo Degremont, Inc. Aquaray® 40 HO VLS Disinfection System to develop the UV delivered dose flow relationship was conducted at the Parsippany-Troy Hills wastewater treatment plant test site in Parsippany, New Jersey. Three reactor modules were m...

  9. [Hygienic, chemical and ecotoxicological aspects of the disinfection of biologically treated waste water by ozone and UV light].

    PubMed

    Iske, U; Nelle, T; Oberg, C; Rudolph, K U; Zander-Hauck, S

    1996-02-01

    Biologically treated waste water from two different municipal treatment plants with mainly domestic waste water on the one hand and industrial influenced waste water on the other hand was disinfected by UV-irradiation and ozonation. Hygienic, chemical and eco-toxic effects of the disinfection step were examined. It was found that by ozonation as well as by UV-irradiation the required guide and imperative values for fecal and total coliform bacteria were fulfilled. The UV-irradiation induces no changes concerning chemical waste water quality and toxic effects. In contrast to these results ozonation can lead to alterations in chemistry and toxicity depending on the waste water composition.

  10. The effect of inorganic precursors on disinfection byproduct formation during UV-chlorine/chloramine drinking water treatment.

    PubMed

    Lyon, Bonnie A; Dotson, Aaron D; Linden, Karl G; Weinberg, Howard S

    2012-10-01

    Ultraviolet (UV) disinfection is being increasingly used in drinking water treatment. It is important to understand how its application to different types of water may influence finished water quality, particularly as anthropogenic activity continues to impact the quality of source waters. The objective of this study was to evaluate the effect of inorganic precursors on the formation of regulated and unregulated disinfection byproducts (DBPs) during UV irradiation of surface waters when combined with chlorination or chloramination. Samples were collected from three drinking water utilities supplied by source waters with varying organic and inorganic precursor content. The filtered samples were treated in the laboratory with a range of UV doses delivered from low pressure (LP, UV output at 253.7 nm) and medium pressure (MP, polychromatic UV output 200-400 nm) mercury lamps followed by chlorination or chloramination, in the presence and absence of additional bromide and nitrate. The regulated trihalomethanes and haloacetic acids were not affected by UV pretreatment at disinfection doses (40-186 mJ/cm²). With higher doses (1000 mJ/cm²), trihalomethane formation was increased 30-40%. While most effects on DBPs were only observed with doses much higher than typically used for UV disinfection, there were some effects on unregulated DBPs at lower doses. In nitrate-spiked samples (1-10 mg N/L), chloropicrin formation doubled and increased three- to six-fold with 40 mJ/cm² MP UV followed by chloramination and chlorination, respectively. Bromopicrin formation was increased in samples containing bromide (0.5-1 mg/L) and nitrate (1-10 mg N/L) when pretreated with LP or MP UV (30-60% with 40 mJ/cm² LP UV and four- to ten-fold increase with 40 mJ/cm² MP UV, after subsequent chlorination). The formation of cyanogen chloride doubled and increased three-fold with MP UV doses of 186 and 1000 mJ/cm², respectively, when followed by chloramination in nitrate-spiked samples but

  11. Numerical study of the effects of lamp configuration and reactor wall roughness in an open channel water disinfection UV reactor.

    PubMed

    Sultan, Tipu

    2016-07-01

    This article describes the assessment of a numerical procedure used to determine the UV lamp configuration and surface roughness effects on an open channel water disinfection UV reactor. The performance of the open channel water disinfection UV reactor was numerically analyzed on the basis of the performance indictor reduction equivalent dose (RED). The RED values were calculated as a function of the Reynolds number to monitor the performance. The flow through the open channel UV reactor was modelled using a k-ε model with scalable wall function, a discrete ordinate (DO) model for fluence rate calculation, a volume of fluid (VOF) model to locate the unknown free surface, a discrete phase model (DPM) to track the pathogen transport, and a modified law of the wall to incorporate the reactor wall roughness effects. The performance analysis was carried out using commercial CFD software (ANSYS Fluent 15.0). Four case studies were analyzed based on open channel UV reactor type (horizontal and vertical) and lamp configuration (parallel and staggered). The results show that lamp configuration can play an important role in the performance of an open channel water disinfection UV reactor. The effects of the reactor wall roughness were Reynolds number dependent. The proposed methodology is useful for performance optimization of an open channel water disinfection UV reactor.

  12. Numerical study of the effects of lamp configuration and reactor wall roughness in an open channel water disinfection UV reactor.

    PubMed

    Sultan, Tipu

    2016-07-01

    This article describes the assessment of a numerical procedure used to determine the UV lamp configuration and surface roughness effects on an open channel water disinfection UV reactor. The performance of the open channel water disinfection UV reactor was numerically analyzed on the basis of the performance indictor reduction equivalent dose (RED). The RED values were calculated as a function of the Reynolds number to monitor the performance. The flow through the open channel UV reactor was modelled using a k-ε model with scalable wall function, a discrete ordinate (DO) model for fluence rate calculation, a volume of fluid (VOF) model to locate the unknown free surface, a discrete phase model (DPM) to track the pathogen transport, and a modified law of the wall to incorporate the reactor wall roughness effects. The performance analysis was carried out using commercial CFD software (ANSYS Fluent 15.0). Four case studies were analyzed based on open channel UV reactor type (horizontal and vertical) and lamp configuration (parallel and staggered). The results show that lamp configuration can play an important role in the performance of an open channel water disinfection UV reactor. The effects of the reactor wall roughness were Reynolds number dependent. The proposed methodology is useful for performance optimization of an open channel water disinfection UV reactor. PMID:27108375

  13. Photoreactivation of bacteriophages after UV disinfection: role of genome structure and impacts of UV source.

    PubMed

    Rodriguez, Roberto A; Bounty, Sarah; Beck, Sara; Chan, Connie; McGuire, Christian; Linden, Karl G

    2014-05-15

    The UV inactivation kinetics of bacteriophages MS2, PhiX174, T1 and PRD1 and the potential of bacterial UV repair mechanisms to reactivate these bacteriophages is described here. The selected bacteriophages represent a range of genome size, single and double stranded genomes, circular and linear organization and RNA and DNA. Bacteriophages were exposed to UV irradiation from two different collimated beam UV irradiation sources (medium-pressure (MP) mercury lamps and low-pressure (LP) mercury lamps) and assayed during which host-phage cultures were exposed to photoreactivating light for 6 h, then incubated overnight at 37 °C in the dark. Dark controls following UV exposure were performed in parallel. UV inactivation kinetics (using dark controls) showed that circular ssDNA phage (PhiX174) was the most sensitive and linear ssRNA phage (MS2) was the more resistant phage. No photoreactivation was observed for MS2 (RNA phage) and the highest photoreactivation was observed for PRD1. In the case of PRD1, the dose required for 4-log reduction (dark control) was around 35 mJ/cm(2), with a similar dose observed for both UV sources (MP and LP). When the photoreactivation step was added, the dose required for 4-log reduction using LP lamps was 103 mJ/cm(2) and for MP lamps was 60 mJ/cm(2). Genome organization differences between bacteriophages play an important role in resistance to UV inactivation and potential photoreactivation mediated by bacterial host mechanisms. The use of photoreactivation during the assay of PRD1 creates a more conservative surrogate for potential use in UV challenge testing.

  14. Toxicity on aquatic organisms exposed to secondary effluent disinfected with chlorine, peracetic acid, ozone and UV radiation.

    PubMed

    da Costa, Juliana Berninger; Rodgher, Suzelei; Daniel, Luiz Antonio; Espíndola, Evaldo Luiz Gaeta

    2014-11-01

    The toxic potential of four disinfectant agents (chlorine, ozone, peracetic acid and UV radiation), used in the disinfection of urban wastewater, was evaluated with respect to four aquatic organisms. Disinfection assays were carried out with wastewater from the city of Araraquara (São Paulo State, Brazil), and subsequently, toxicity bioassays were applied in order to verify possible adverse effects to the cladocerans (Ceriodaphnia silvestrii and Daphnia similis), midge larvae Chironomus xanthus and fish (Danio rerio). Under the experimental conditions tested, all the disinfectants were capable of producing harmful effects on the test organisms, except for C. xanthus. The toxicity of the effluent to C. silvestrii was observed to increase significantly as a result of disinfection using 2.5 mg L(-1) chlorine and 29.9 mg L(-1) ozone. Ozonation and chlorination significantly affected the survival of D. similis and D. rerio, causing mortality of 60 to 100 % in comparison to the non-disinfected effluent. In experiments with effluent treated with peracetic acid (PAA) and UV radiation, a statistically significant decrease in survival was only detected for D. rerio. This investigation suggested that the study of the ideal concentrations of disinfectants is a research need for ecologically safe options for the treatment of wastewater.

  15. Toxicity on aquatic organisms exposed to secondary effluent disinfected with chlorine, peracetic acid, ozone and UV radiation.

    PubMed

    da Costa, Juliana Berninger; Rodgher, Suzelei; Daniel, Luiz Antonio; Espíndola, Evaldo Luiz Gaeta

    2014-11-01

    The toxic potential of four disinfectant agents (chlorine, ozone, peracetic acid and UV radiation), used in the disinfection of urban wastewater, was evaluated with respect to four aquatic organisms. Disinfection assays were carried out with wastewater from the city of Araraquara (São Paulo State, Brazil), and subsequently, toxicity bioassays were applied in order to verify possible adverse effects to the cladocerans (Ceriodaphnia silvestrii and Daphnia similis), midge larvae Chironomus xanthus and fish (Danio rerio). Under the experimental conditions tested, all the disinfectants were capable of producing harmful effects on the test organisms, except for C. xanthus. The toxicity of the effluent to C. silvestrii was observed to increase significantly as a result of disinfection using 2.5 mg L(-1) chlorine and 29.9 mg L(-1) ozone. Ozonation and chlorination significantly affected the survival of D. similis and D. rerio, causing mortality of 60 to 100 % in comparison to the non-disinfected effluent. In experiments with effluent treated with peracetic acid (PAA) and UV radiation, a statistically significant decrease in survival was only detected for D. rerio. This investigation suggested that the study of the ideal concentrations of disinfectants is a research need for ecologically safe options for the treatment of wastewater. PMID:25213288

  16. Inactivation and UV Disinfection of Murine Norovirus with TiO2 under Various Environmental Conditions▿

    PubMed Central

    Lee, JungEun; Zoh, KyungDuk; Ko, GwangPyo

    2008-01-01

    We studied inactivation and UV disinfection of murine norovirus (MNV) as a surrogate for human norovirus. We investigated the effects of different surface characteristics, temperatures, and NaCl concentrations on MNV survival using both a plaque assay and a real-time TaqMan reverse transcription (RT)-PCR assay. MNV survived more than 40 days on diaper material, on gauze, and in a stool suspension. Compared to inactivation at lower temperatures (−20 and 4°C), inactivation of MNV was greater at higher temperatures (18 and 30°C). On the surface of both gauze and diaper material, there was a <2-log10 reduction in the amount of infectious MNV in 40 days after incubation at both −20 and 4°C, compared to a >5-log10 reduction after incubation at 30°C in 24 days. MNV survived better in a stool suspension than on the surface of gauze or diaper material. A higher salt concentration increased the rate of inactivation of MNV. In 72 h, <0.3-, 1.5-, and 2.5-log10 reductions in the amount of infectious MNV occurred in distilled water and 0.5 and 1 M NaCl, respectively. We observed only minor reductions in the numbers of viral RNA copies as quantified by real-time TaqMan RT-PCR regardless of the temperature, the salt concentration, or the suspending medium. We also evaluated UV disinfection of infectious MNV with and without TiO2. The amount of MNV was significantly reduced by 254-nm UV with and without TiO2. When 25 mJ/cm2 UV was used, 3.3- and 3.6-log10 reductions in the amounts of infectious MNV occurred with and without TiO2, respectively. Our results demonstrate that MNV can persist in various environmental conditions and can be efficiently controlled by UV disinfection. PMID:18245239

  17. Disinfection efficiency of peracetic acid, UV and ozone after enhanced primary treatment of municipal wastewater.

    PubMed

    Gehr, Ronald; Wagner, Monika; Veerasubramanian, Priya; Payment, Pierre

    2003-11-01

    The City of Montreal Wastewater Treatment Plant uses enhanced physicochemical processes (ferric and/or alum coagulation) for suspended solids and phosphorus removal. The objective of this study was to assess the ability of peracetic acid (PAA), UV, or ozone to inactivate the indicator organisms fecal coliforms, Enterococci, MS-2 coliphage, or Clostridium perfringens in the effluent from this plant. PAA doses to reach the target fecal coliform level of 9000 CFU/100mL exceeded 6 mg/L; similar results were obtained for enterococci, and no inactivation of Clostridium perfringens was observed. However a 1-log reduction of MS-2 occurred at PAA doses of 1.5 mg/L and higher. It was expected that this effluent would have a high ozone demand, and would require relatively high UV fluences, because of relatively high effluent COD, iron and suspended solids concentrations, and low UV transmittance. This was confirmed herein. For UV, the inactivation curve for fecal coliforms showed the typical two-stage shape, with the target of 1000 CFU/100 mL (to account for photoreactivation) occurring in the asymptote zone at fluences >20 mJ/cm(2). In contrast, inactivation curves for MS-2 and Clostridium perfringens were linear. Clostridium perfringens was the most resistant organism. For ozone, inactivation was already observed before any residuals could be measured. The transferred ozone doses to reach target fecal coliform levels ( approximately 2-log reduction) were 30-50 mg/L. MS-2 was less resistant, but Clostridium perfringens was more resistant than fecal coliforms. The different behaviour of the four indicator organisms studied, depending on the disinfectant, suggests that a single indicator organism might not be appropriate. The required dose of any of the disinfectants is unlikely to be economically viable, and upstream changes to the plant will be needed. PMID:14568042

  18. Disinfection efficiency of peracetic acid, UV and ozone after enhanced primary treatment of municipal wastewater.

    PubMed

    Gehr, Ronald; Wagner, Monika; Veerasubramanian, Priya; Payment, Pierre

    2003-11-01

    The City of Montreal Wastewater Treatment Plant uses enhanced physicochemical processes (ferric and/or alum coagulation) for suspended solids and phosphorus removal. The objective of this study was to assess the ability of peracetic acid (PAA), UV, or ozone to inactivate the indicator organisms fecal coliforms, Enterococci, MS-2 coliphage, or Clostridium perfringens in the effluent from this plant. PAA doses to reach the target fecal coliform level of 9000 CFU/100mL exceeded 6 mg/L; similar results were obtained for enterococci, and no inactivation of Clostridium perfringens was observed. However a 1-log reduction of MS-2 occurred at PAA doses of 1.5 mg/L and higher. It was expected that this effluent would have a high ozone demand, and would require relatively high UV fluences, because of relatively high effluent COD, iron and suspended solids concentrations, and low UV transmittance. This was confirmed herein. For UV, the inactivation curve for fecal coliforms showed the typical two-stage shape, with the target of 1000 CFU/100 mL (to account for photoreactivation) occurring in the asymptote zone at fluences >20 mJ/cm(2). In contrast, inactivation curves for MS-2 and Clostridium perfringens were linear. Clostridium perfringens was the most resistant organism. For ozone, inactivation was already observed before any residuals could be measured. The transferred ozone doses to reach target fecal coliform levels ( approximately 2-log reduction) were 30-50 mg/L. MS-2 was less resistant, but Clostridium perfringens was more resistant than fecal coliforms. The different behaviour of the four indicator organisms studied, depending on the disinfectant, suggests that a single indicator organism might not be appropriate. The required dose of any of the disinfectants is unlikely to be economically viable, and upstream changes to the plant will be needed.

  19. Disinfection.

    ERIC Educational Resources Information Center

    Gould, J. P.; Haas, C. N.

    1978-01-01

    Presents a literature review of wastewater disinfection for 1978. This review covers areas such as: (1) mechanisms of inactivation of negative microorganisms by chlorine and ozone; and (2) the effects of various treatment on over-all water quality. A list of 61 references is also presented. (HM)

  20. DISINFECTION

    EPA Science Inventory

    The primary goal of the disinfection process in drinking water treatment is the inactivation of microbial pathogens. These pathogens comprise a diverse group of organisms which serve as the etiological agents of waterborne disease. Included in this group are bacterial, viral and ...

  1. Inactivation of Escherichia coli, Bacteriophage MS2, and Bacillus Spores under UV/H2O2 and UV/Peroxydisulfate Advanced Disinfection Conditions.

    PubMed

    Sun, Peizhe; Tyree, Corey; Huang, Ching-Hua

    2016-04-19

    Ultraviolet light (UV) combined with peroxy chemicals, such as H2O2 and peroxydisulfate (PDS), have been considered potentially highly effective disinfection processes. This study investigated the inactivation of Escherichia coli, bacteriophage MS2, and Bacillus subtilis spores as surrogates for pathogens under UV/H2O2 and UV/PDS conditions, with the aim to provide further understanding of UV-based advanced disinfection processes (ADPs). Results showed that one additional log of inactivation of E. coli was achieved with 0.3 mM H2O2 or PDS at 5.2 × 10(-5) Einstein·L(-1) photo fluence (at 254 nm) compared with UV irradiation alone. Addition of H2O2 and PDS greatly enhanced the inactivation rate of MS2 by around 15 folds and 3 folds, respectively, whereas the inactivation of B. subtilis spores was slightly enhanced. Reactive species responsible for the inactivation were identified to be •OH, SO4(·-), and CO3(·-) based on manipulation of solution conditions. The CT value of each reactive species was calculated with respect to each microbial surrogate, which showed that the disinfection efficacy ranked as •OH > SO4(·-) > CO3(·-) ≫ O2(·-)/HO2(·). A comprehensive dynamic model was developed and successfully predicted the inactivation of the microbial surrogates in surface water and wastewater matrices. The concepts of UV-efficiency and EE/O were employed to provide a cost-effective evaluation for UV-based ADPs. Overall, the present study suggests that it will be beneficial to upgrade UV disinfection to UV/H2O2 ADP for the inactivation of viral pathogens.

  2. Inactivation of Escherichia coli, Bacteriophage MS2, and Bacillus Spores under UV/H2O2 and UV/Peroxydisulfate Advanced Disinfection Conditions.

    PubMed

    Sun, Peizhe; Tyree, Corey; Huang, Ching-Hua

    2016-04-19

    Ultraviolet light (UV) combined with peroxy chemicals, such as H2O2 and peroxydisulfate (PDS), have been considered potentially highly effective disinfection processes. This study investigated the inactivation of Escherichia coli, bacteriophage MS2, and Bacillus subtilis spores as surrogates for pathogens under UV/H2O2 and UV/PDS conditions, with the aim to provide further understanding of UV-based advanced disinfection processes (ADPs). Results showed that one additional log of inactivation of E. coli was achieved with 0.3 mM H2O2 or PDS at 5.2 × 10(-5) Einstein·L(-1) photo fluence (at 254 nm) compared with UV irradiation alone. Addition of H2O2 and PDS greatly enhanced the inactivation rate of MS2 by around 15 folds and 3 folds, respectively, whereas the inactivation of B. subtilis spores was slightly enhanced. Reactive species responsible for the inactivation were identified to be •OH, SO4(·-), and CO3(·-) based on manipulation of solution conditions. The CT value of each reactive species was calculated with respect to each microbial surrogate, which showed that the disinfection efficacy ranked as •OH > SO4(·-) > CO3(·-) ≫ O2(·-)/HO2(·). A comprehensive dynamic model was developed and successfully predicted the inactivation of the microbial surrogates in surface water and wastewater matrices. The concepts of UV-efficiency and EE/O were employed to provide a cost-effective evaluation for UV-based ADPs. Overall, the present study suggests that it will be beneficial to upgrade UV disinfection to UV/H2O2 ADP for the inactivation of viral pathogens. PMID:27014964

  3. Efficiency of the UV/H2O2 process for the disinfection of humic surface waters.

    PubMed

    Alkan, Ufuk; Teksoy, Arzu; Atesli, Ahu; Baskaya, Huseyin S

    2007-03-01

    The efficiency of the UV/H2O2 process for the disinfection of total coliforms and the prevention of bacterial regrowth in humic surface waters were investigated. Inactivation of total coliforms was determined in water samples containing various concentrations ranging from 0-10 mg/L dissolved organic carbon (DOC) of fulvic acid, which were exposed to various doses (68-681 mWs/cm2) of UV radiation in the presence of 0.125 mg/L and 3.000 mg/L of hydrogen peroxide. Disinfection efficiencies of the UV radiation and the UV/H2O2 processes were compared. The results of bacterial inactivation experiments showed that the performances of the UV and the UV/H2O2 (0.125) were comparable whereas the UV/H2O2 (3.000) process showed significant improvement in performance, especially, in highly humic waters. Inactivation coefficient appeared to be almost doubled by the addition of 3.000 mg/L hydrogen peroxide during the treatment of highly humic waters. In contradiction to significant regrowth which occurred in the single UV radiation treatment, residual bacteria following the UV/H2O2 (0.125) and the UV/H2O2 (3.000) treatments were completely inactivated during dark incubation indicating the elimination of possible bacterial regrowth.

  4. UV disinfection of RBC-treated light greywater effluent: kinetics, survival and regrowth of selected microorganisms.

    PubMed

    Gilboa, Yael; Friedler, Eran

    2008-02-01

    The microbial quality of raw greywater was found to be much better than that of municipal wastewater, with 1.6 x 10(7)cfu ml(-1) heterotrophic plate count (HPC), and 3.8 x 10(4), 9.9 x 10(3), 3.3 x 10(3) and 4.6 x 10(0)cfu 100 ml(-1) faecal coliforms (FC), Staphylococcus aureus sp., Pseudomonas aeruginosa sp. and Clostridium perfringes sp., respectively. Further, three viral indicators monitored (somatic phage, host: Escherichia coli CN(13) and F-RNA phages, hosts: E. coli F+(amp), E. coli K12) were not present in raw greywater. The greywater was treated by an RBC followed by sedimentation. The treatment removed two orders of magnitude of all bacteria. UV disinfection kinetics, survival and regrowth of HPC, FC, P. aeruginosa sp. and S. aureus sp. were examined. At doses up to 69 mW s cm(-2) FC were found to be the most resistant bacteria, followed by HPC, P. aeruginosa sp. and S. aureus sp. (inactivation rate coefficients: 0.0687, 0.113, 0.129 and 0.201 cm2 mW(-1)s(-1), respectively). At higher doses (69-439 mW s cm(-2)) all but HPC (which exhibited a tailing curve) were completely eliminated. Microscopic examination showed that FC self-aggregate in the greywater effluent. This provides FC an advantage at low doses, since the concentration of suspended matter (that can provide shelter from UV radiation) in the effluent was very low. FC, P. aeruginosa sp. and S. aureus sp. did not exhibit regrowth up to 6h after exposure to increasing UV doses (19-439 mW s cm(-2)). HPC regrowth was proven to be statistically significant in un-disinfected effluent and after irradiation with high UV doses (147 and 439 mW s cm(-2)). At these doses regrowth resulted from growth of UV-resistant bacteria due to decreased competition with other bacteria eliminated by the irradiation.

  5. Heuristic optimization of a continuous flow point-of-use UV-LED disinfection reactor using computational fluid dynamics.

    PubMed

    Jenny, Richard M; Jasper, Micah N; Simmons, Otto D; Shatalov, Max; Ducoste, Joel J

    2015-10-15

    Alternative disinfection sources such as ultraviolet light (UV) are being pursued to inactivate pathogenic microorganisms such as Cryptosporidium and Giardia, while simultaneously reducing the risk of exposure to carcinogenic disinfection by-products (DBPs) in drinking water. UV-LEDs offer a UV disinfecting source that do not contain mercury, have the potential for long lifetimes, are robust, and have a high degree of design flexibility. However, the increased flexibility in design options will add a substantial level of complexity when developing a UV-LED reactor, particularly with regards to reactor shape, size, spatial orientation of light, and germicidal emission wavelength. Anticipating that LEDs are the future of UV disinfection, new methods are needed for designing such reactors. In this research study, the evaluation of a new design paradigm using a point-of-use UV-LED disinfection reactor has been performed. ModeFrontier, a numerical optimization platform, was coupled with COMSOL Multi-physics, a computational fluid dynamics (CFD) software package, to generate an optimized UV-LED continuous flow reactor. Three optimality conditions were considered: 1) single objective analysis minimizing input supply power while achieving at least (2.0) log10 inactivation of Escherichia coli ATCC 11229; and 2) two multi-objective analyses (one of which maximized the log10 inactivation of E. coli ATCC 11229 and minimized the supply power). All tests were completed at a flow rate of 109 mL/min and 92% UVT (measured at 254 nm). The numerical solution for the first objective was validated experimentally using biodosimetry. The optimal design predictions displayed good agreement with the experimental data and contained several non-intuitive features, particularly with the UV-LED spatial arrangement, where the lights were unevenly populated throughout the reactor. The optimal designs may not have been developed from experienced designers due to the increased degrees of

  6. Heuristic optimization of a continuous flow point-of-use UV-LED disinfection reactor using computational fluid dynamics.

    PubMed

    Jenny, Richard M; Jasper, Micah N; Simmons, Otto D; Shatalov, Max; Ducoste, Joel J

    2015-10-15

    Alternative disinfection sources such as ultraviolet light (UV) are being pursued to inactivate pathogenic microorganisms such as Cryptosporidium and Giardia, while simultaneously reducing the risk of exposure to carcinogenic disinfection by-products (DBPs) in drinking water. UV-LEDs offer a UV disinfecting source that do not contain mercury, have the potential for long lifetimes, are robust, and have a high degree of design flexibility. However, the increased flexibility in design options will add a substantial level of complexity when developing a UV-LED reactor, particularly with regards to reactor shape, size, spatial orientation of light, and germicidal emission wavelength. Anticipating that LEDs are the future of UV disinfection, new methods are needed for designing such reactors. In this research study, the evaluation of a new design paradigm using a point-of-use UV-LED disinfection reactor has been performed. ModeFrontier, a numerical optimization platform, was coupled with COMSOL Multi-physics, a computational fluid dynamics (CFD) software package, to generate an optimized UV-LED continuous flow reactor. Three optimality conditions were considered: 1) single objective analysis minimizing input supply power while achieving at least (2.0) log10 inactivation of Escherichia coli ATCC 11229; and 2) two multi-objective analyses (one of which maximized the log10 inactivation of E. coli ATCC 11229 and minimized the supply power). All tests were completed at a flow rate of 109 mL/min and 92% UVT (measured at 254 nm). The numerical solution for the first objective was validated experimentally using biodosimetry. The optimal design predictions displayed good agreement with the experimental data and contained several non-intuitive features, particularly with the UV-LED spatial arrangement, where the lights were unevenly populated throughout the reactor. The optimal designs may not have been developed from experienced designers due to the increased degrees of

  7. Protection against UV disinfection of E. coli bacteria and B. subtilis spores ingested by C. elegans nematodes.

    PubMed

    Bichai, Françoise; Barbeau, Benoit; Payment, Pierre

    2009-08-01

    Nematodes, which occur abundantly in granular media filters of drinking water treatment plants and in distribution systems, can ingest and transport pathogenic bacteria and provide them protection against chemical disinfectants. However, protection against UV disinfection had not been investigated to date. In this study, Caenorhabditis elegans nematodes (wild-type strain N2) were allowed to feed on Escherichia coli OP50 and Bacillus subtilis spores before being exposed to 5 and 40 mJ/cm(2) UV fluences, using a collimated beam apparatus (LP, 254 nm). Sonication (15 W, 60s) was used to extract bacteria from nematode guts following UV exposure in order to assess the amount of ingested bacteria that resisted the UV treatment using a standard culture method. Bacteria located inside the gut of C. elegans were shown to benefit from a significant protection against UV. Approximately 15% of the applied UV fluence of 40 mJ/cm(2) (as typically used in WTP) was found to reach the bacteria located inside nematode guts based on the inactivation of recovered bacteria (2.7 log reduction of E. coli bacteria and 0.7 log reduction of B. subtilis spores at 40 mJ/cm(2)). To our knowledge, this study is the first demonstration of the protection effect of bacterial internalization by higher organisms against UV treatment, using the specific case of E. coli and B. subtilis spores ingested by C. elegans.

  8. Application of a molecular biology concept for the detection of DNA damage and repair during UV disinfection.

    PubMed

    Süss, Jacqueline; Volz, Sabrina; Obst, Ursula; Schwartz, Thomas

    2009-08-01

    As nucleic acids are major targets in bacteria during standardised UV disinfection (254 nm), inactivation rates also depend on bacterial DNA repair. Due to UV-related DNA modifications, PCR-based approaches allow for a direct detection of DNA damage and repair during UV disinfection. By applying different primer sets, the correlation between amplicon length and PCR amplification became obvious. The longer the targeted DNA fragment was, the more UV-induced DNA lesions inhibited the PCR. Regeneration of Pseudomonas aeruginosa, Enterococcus faecium, and complex wastewater communities was recorded over a time period of 66 h. While phases of intensive repair and proliferation were found for P. aeruginosa, no DNA repair was detected by qPCR in E. faecium. Cultivation experiments verified these results. Despite high UV mediated inactivation rates original wastewater bacteria seem to express an enhanced robustness against irradiation. Regeneration of dominant and proliferation of low-abundant, probably UV-resistant species contributed to a strong post-irradiation recovery accompanied by a selection for beta-Proteobacteria.

  9. Impact of UV and Peracetic Acid Disinfection on the Prevalence of Virulence and Antimicrobial Resistance Genes in Uropathogenic Escherichia coli in Wastewater Effluents

    PubMed Central

    Biswal, Basanta Kumar; Khairallah, Ramzi; Bibi, Kareem; Mazza, Alberto; Gehr, Ronald; Masson, Luke

    2014-01-01

    Wastewater discharges may increase the populations of pathogens, including Escherichia coli, and of antimicrobial-resistant strains in receiving waters. This study investigated the impact of UV and peracetic acid (PAA) disinfection on the prevalence of virulence and antimicrobial resistance genes in uropathogenic Escherichia coli (UPEC), the most abundant E. coli pathotype in municipal wastewaters. Laboratory disinfection experiments were conducted on wastewater treated by physicochemical, activated sludge, or biofiltration processes; 1,766 E. coli isolates were obtained for the evaluation. The target disinfection level was 200 CFU/100 ml, resulting in UV and PAA doses of 7 to 30 mJ/cm2 and 0.9 to 2.0 mg/liter, respectively. The proportions of UPECs were reduced in all samples after disinfection, with an average reduction by UV of 55% (range, 22% to 80%) and by PAA of 52% (range, 11% to 100%). Analysis of urovirulence genes revealed that the decline in the UPEC populations was not associated with any particular virulence factor. A positive association was found between the occurrence of urovirulence and antimicrobial resistance genes (ARGs). However, the changes in the prevalence of ARGs in potential UPECs were different following disinfection, i.e., UV appears to have had no effect, while PAA significantly reduced the ARG levels. Thus, this study showed that both UV and PAA disinfections reduced the proportion of UPECs and that PAA disinfection also reduced the proportion of antimicrobial resistance gene-carrying UPEC pathotypes in municipal wastewaters. PMID:24727265

  10. Impact of UV and peracetic acid disinfection on the prevalence of virulence and antimicrobial resistance genes in uropathogenic Escherichia coli in wastewater effluents.

    PubMed

    Biswal, Basanta Kumar; Khairallah, Ramzi; Bibi, Kareem; Mazza, Alberto; Gehr, Ronald; Masson, Luke; Frigon, Dominic

    2014-06-01

    Wastewater discharges may increase the populations of pathogens, including Escherichia coli, and of antimicrobial-resistant strains in receiving waters. This study investigated the impact of UV and peracetic acid (PAA) disinfection on the prevalence of virulence and antimicrobial resistance genes in uropathogenic Escherichia coli (UPEC), the most abundant E. coli pathotype in municipal wastewaters. Laboratory disinfection experiments were conducted on wastewater treated by physicochemical, activated sludge, or biofiltration processes; 1,766 E. coli isolates were obtained for the evaluation. The target disinfection level was 200 CFU/100 ml, resulting in UV and PAA doses of 7 to 30 mJ/cm(2) and 0.9 to 2.0 mg/liter, respectively. The proportions of UPECs were reduced in all samples after disinfection, with an average reduction by UV of 55% (range, 22% to 80%) and by PAA of 52% (range, 11% to 100%). Analysis of urovirulence genes revealed that the decline in the UPEC populations was not associated with any particular virulence factor. A positive association was found between the occurrence of urovirulence and antimicrobial resistance genes (ARGs). However, the changes in the prevalence of ARGs in potential UPECs were different following disinfection, i.e., UV appears to have had no effect, while PAA significantly reduced the ARG levels. Thus, this study showed that both UV and PAA disinfections reduced the proportion of UPECs and that PAA disinfection also reduced the proportion of antimicrobial resistance gene-carrying UPEC pathotypes in municipal wastewaters. PMID:24727265

  11. ENVIRONMENTAL TECHNOLOGY VERIFICATION: JOINT (NSF-EPA) VERIFICATION STATEMENT AND REPORT FOR THE UV DISINFECTION OF SECONDARY EFFLUENTS, SUNTEC, INC. MODEL LPX200 DISINFECTION SYSTEM - 03/09/WQPC-SWP

    EPA Science Inventory

    Verification testing of the SUNTEC LPX200 UV Disinfection System to develop the UV delivered dose flow relationship was conducted at the Parsippany-Troy Hills wastewater treatment plant test site in Parsippany, New Jersey. Two lamp modules were mounted parallel in a 6.5-meter lon...

  12. A comparative study of disinfection efficiency and regrowth control of microorganism in secondary wastewater effluent using UV, ozone, and ionizing irradiation process.

    PubMed

    Lee, O-Mi; Kim, Hyun Young; Park, Wooshin; Kim, Tae-Hun; Yu, Seungho

    2015-09-15

    Ionizing radiation technology was suggested as an alternative method to disinfection processes, such as chlorine, UV, and ozone. Although many studies have demonstrated the effectiveness of irradiation technology for microbial disinfection, there has been a lack of information on comparison studies of disinfection techniques and a regrowth of each treatment. In the present study, an ionizing radiation was investigated to inactivate microorganisms and to determine the critical dose to prevent the regrowth. As a result, it was observed that the disinfection efficiency using ionizing radiation was not affected by the seasonal changes of wastewater characteristics, such as temperature and turbidity. In terms of bacterial regrowth after disinfection, the ionizing radiation showed a significant resistance of regrowth, whereas, on-site UV treatment is influenced by the suspended solid, temperature, or precipitation. The electric power consumption was also compared for the economic feasibility of each technique at a given value of disinfection efficiency of 90% (1-log), showing 0.12, 36.80, and 96.53 Wh/(L/day) for ionizing radiation, ozone, and UV, respectively. The ionizing radiation requires two or three orders of magnitude lower power consumption than UV and ozone. Consequently, ionizing radiation can be applied as an effective and economical alternative technique to other conventional disinfection processes.

  13. [Disinfection and degradation of 2,4-DCP with UV-radiation and on-line ozone in drinking water treatmeant].

    PubMed

    Ma, Xiaomin; Song, Qiang; Hu, Chun; Wang, Yizhong; Qu, Jiuhui

    2002-09-01

    A type reactor with on-line O3 was used to do further research of the disinfection of total bacteria, E. coli and degradation of 2,4-DCP. The result was obtained in the following conditions. Only UV-radiation, O3 applied by other machine and by the reactor itself, and other conditions were changed to study the disinfection and degradation. The result showed the satisfied effect of disinfection and degradation would be achieved by using UV/O3 applied outside and when the flow rate was about 400 L.h-1, on-line O3 could be produced and make high efforts to enhance disinfection and degradation. The method of UV/O3 was a promising technology in the treatment of drinking water.

  14. Degradation of carbamazepine by UV/chlorine advanced oxidation process and formation of disinfection by-products.

    PubMed

    Zhou, Shiqing; Xia, Ying; Li, Ting; Yao, Tian; Shi, Zhou; Zhu, Shumin; Gao, Naiyun

    2016-08-01

    Pharmaceuticals in water are commonly found and are not efficiently removed by current treatment processes. Degradation of antiepileptic drug carbamazepine (CBZ) by UV/chlorine advanced oxidation process was systematically investigated in this study. The results showed that the UV/chlorine process was more effective at degrading CBZ than either UV or chlorination alone. The CBZ degradation followed pseudo-first order reaction kinetics, and the degradation rate constants (kobs) were affected by the chlorine dose, solution pH, and natural organic matter concentration to different degrees. Degradation of CBZ greatly increased with increasing chlorine dose and decreasing solution pH during the UV/chlorine process. Additionally, the presence of natural organic matter in the solution inhibited the degradation of CBZ. UV photolysis, chlorination, and reactive species (hydroxyl radical •OH and chlorine atoms •Cl) were identified as responsible for CBZ degradation in the UV/chlorine process. Finally, a degradation pathway for CBZ in the UV/chlorine process was proposed and the formation potentials of carbonaceous and nitrogenous disinfection by-products were evaluated. Enhanced formation of trichloroacetic acid, dichloroacetonitrile, and trichloronitromethane precursors should be considered when applying UV/chlorine advanced oxidation process to drinking water. PMID:27164884

  15. Emerging micropollutant oxidation during disinfection processes using UV-C, UV-C/H2O2, UV-A/TiO2 and UV-A/TiO2/H2O2.

    PubMed

    Pablos, Cristina; Marugán, Javier; van Grieken, Rafael; Serrano, Elena

    2013-03-01

    Regeneration of wastewater treatment plant effluents constitutes a solution to increase the availability of water resources in arid regions. Water reuse legislation imposes an exhaustive control of the microbiological quality of water in the operation of disinfection tertiary treatments. Additionally, recent reports have paid increasing attention to emerging micropollutants with potential biological effects even at trace level concentration. This work focuses on the evaluation of several photochemical technologies as disinfection processes with the aim of simultaneously achieving bacterial inactivation and oxidation of pharmaceuticals as examples of emerging micropollutants typically present in water and widely studied in the literature. UV-C-based processes show a high efficiency to inactivate bacteria. However, the bacterial damages are reversible and only when using H(2)O(2), bacterial reproduction is affected. Moreover, a complete elimination of pharmaceutical compounds was not achieved at the end of the inactivation process. In contrast, UV-A/TiO(2) required a longer irradiation time to inactivate bacteria but pharmaceuticals were completely removed along the process. In addition, its oxidation mechanism, based on hydroxyl radicals (OH), leads to irreversible bacterial damages, not requiring of chemicals to avoid bacterial regrowth. For UV-A/TiO(2)/H(2)O(2) process, the addition of H(2)O(2) improved Escherichia coli inactivation since the cell wall weakening, due to OH attacks, allowed H(2)O(2) to diffuse into the bacteria. However, a total elimination of the pharmaceuticals was not achieved during the inactivation process.

  16. Emerging micropollutant oxidation during disinfection processes using UV-C, UV-C/H2O2, UV-A/TiO2 and UV-A/TiO2/H2O2.

    PubMed

    Pablos, Cristina; Marugán, Javier; van Grieken, Rafael; Serrano, Elena

    2013-03-01

    Regeneration of wastewater treatment plant effluents constitutes a solution to increase the availability of water resources in arid regions. Water reuse legislation imposes an exhaustive control of the microbiological quality of water in the operation of disinfection tertiary treatments. Additionally, recent reports have paid increasing attention to emerging micropollutants with potential biological effects even at trace level concentration. This work focuses on the evaluation of several photochemical technologies as disinfection processes with the aim of simultaneously achieving bacterial inactivation and oxidation of pharmaceuticals as examples of emerging micropollutants typically present in water and widely studied in the literature. UV-C-based processes show a high efficiency to inactivate bacteria. However, the bacterial damages are reversible and only when using H(2)O(2), bacterial reproduction is affected. Moreover, a complete elimination of pharmaceutical compounds was not achieved at the end of the inactivation process. In contrast, UV-A/TiO(2) required a longer irradiation time to inactivate bacteria but pharmaceuticals were completely removed along the process. In addition, its oxidation mechanism, based on hydroxyl radicals (OH), leads to irreversible bacterial damages, not requiring of chemicals to avoid bacterial regrowth. For UV-A/TiO(2)/H(2)O(2) process, the addition of H(2)O(2) improved Escherichia coli inactivation since the cell wall weakening, due to OH attacks, allowed H(2)O(2) to diffuse into the bacteria. However, a total elimination of the pharmaceuticals was not achieved during the inactivation process. PMID:23276426

  17. Characterization of biofilm and corrosion of cast iron pipes in drinking water distribution system with UV/Cl2 disinfection.

    PubMed

    Zhu, Ying; Wang, Haibo; Li, Xiaoxiao; Hu, Chun; Yang, Min; Qu, Jiuhui

    2014-09-01

    The effect of UV/Cl2 disinfection on the biofilm and corrosion of cast iron pipes in drinking water distribution system were studied using annular reactors (ARs). Passivation occurred more rapidly in the AR with UV/Cl2 than in the one with Cl2 alone, decreasing iron release for higher corrosivity of water. Based on functional gene, pyrosequencing assays and principal component analysis, UV disinfection not only reduced the required initial chlorine dose, but also enhanced denitrifying functional bacteria advantage in the biofilm of corrosion scales. The nitrate-reducing bacteria (NRB) Dechloromonas exhibited the greatest corrosion inhibition by inducing the redox cycling of iron to enhance the precipitation of iron oxides and formation of Fe3O4 in the AR with UV/Cl2, while the rhizobia Bradyrhizobium and Rhizobium, and the NRB Sphingomonas, Brucella producing siderophores had weaker corrosion-inhibition effect by capturing iron in the AR with Cl2. These results indicated that the microbial redox cycling of iron was possibly responsible for higher corrosion inhibition and lower effect of water Larson-Skold Index (LI) changes on corrosion. This finding could be applied toward the control of water quality in drinking water distribution systems.

  18. Role of ozone in UV-C disinfection, demonstrated by comparison between wild-type and mutant conidia of Aspergillus niger.

    PubMed

    Liu, Jing; Zhou, Lin; Chen, Ji-Hong; Mao, Wang; Li, Wen-Jian; Hu, Wei; Wang, Shu-Yang; Wang, Chun-Ming

    2014-01-01

    This study aimed to investigate the tolerance of a melanized wild-type strain of Aspergillus niger (CON1) and its light-colored mutant (MUT1) to UV-C light and the concomitantly generated ozone. Treatments were segregated into four groups based on whether UV irradiation was used and the presence or absence of ozone: (-UV, -O3), (-UV, +O3), (+UV, -O3) and (+UV, +O3). The survival of CON1 and MUT1 conidia under +UV decreased as the exposure time increased, with CON1 showing greater resistance to UV irradiation than MUT1. Ozone induced CON1 conidium inactivation only under conditions of UV radiation exposure. While, the inactivation effect of ozone on MUT1 was always detectable regardless of the presence of UV irradiation. Furthermore, the CON1 conidial suspension showed lower UV light transmission than MUT1 when examined at the same concentration. Compared with the pigment in MUT1, the melanin in CON1 exhibited more potent radical-scavenging activity and stronger UV absorbance. These results suggested that melanin protected A. niger against UV disinfection via UV screening and free radical scavenging. The process by which UV-C disinfection induces a continual decrease in conidial survival suggests that UV irradiation and ozone exert a synergistic fungicidal effect on A. niger prior to reaching a plateau.

  19. Applicability of integrated cell culture quantitative PCR (ICC-qPCR) for the detection of infectious adenovirus type 2 in UV disinfection studies

    EPA Science Inventory

    Human adenovirus is relatively resistant to UV radiation and has been used as a conservative testing microbe for evaluations of UV disinfection systems as components of water treatment processes. In this study, we attempted to validate the applicability of integrated cell culture...

  20. Comparative effectiveness of membrane bioreactors, conventional secondary treatment, and chlorine and UV disinfection to remove microorganisms from municipal wastewaters

    USGS Publications Warehouse

    Francy, Donna S.; Erin, A. Stelzer; Bushon, Rebecca N.; Brady, Amie M.G.; Williston, Ashley G.; Riddell, Kimberly R.; Borchardt, Mark A.; Spencer, Susan K.; Gellner, Terry M.

    2012-01-01

    Log removals of bacterial indicators, coliphage, and enteric viruses were studied in three membrane bioreactor (MBR) activated-sludge and two conventional secondary activated-sludge municipal wastewater treatment plants during three recreational seasons (May-Oct.) when disinfection of effluents is required. In total, 73 regular samples were collected from key locations throughout treatment processes: post-preliminary, post-MBR, post-secondary, post-tertiary, and post-disinfection (UV or chlorine). Out of 19 post-preliminary samples, adenovirus by quantitative polymerase chain reaction (qPCR) was detected in all 19, enterovirus by quantitative reverse transcription polymerase chain reaction (qRT-PCR) was detected in 15, and norovirus GI by qRT-PCR was detected in 11. Norovirus GII and Hepatitis A virus were not detected in any samples, and rotavirus was detected in one sample but could not be quantified. Although culturable viruses were found in 12 out of 19 post-preliminary samples, they were not detected in any post-secondary, post-MBR, post-ultraviolet, or post-chlorine samples. Median log removals for all organisms were higher for MBR secondary treatment (3.02 to >6.73) than for conventional secondary (1.53-4.19) treatment. Ultraviolet disinfection after MBR treatment provided little additional log removal of any organism except for somatic coliphage (>2.18), whereas ultraviolet or chlorine disinfection after conventional secondary treatment provided significant log removals (above the analytical variability) of all bacterial indicators (1.18-3.89) and somatic and F-specific coliphage (0.71 and >2.98). Median log removals of adenovirus across disinfection were low in both MBR and conventional secondary plants (no removal detected and 0.24), and few removals of individual samples were near or above the analytical variability of 1.2 log genomic copies per liter. Based on qualitative examinations of plots showing reductions of organisms throughout treatment

  1. Comparative effectiveness of membrane bioreactors, conventional secondary treatment, and chlorine and UV disinfection to remove microorganisms from municipal wastewaters.

    PubMed

    Francy, Donna S; Stelzer, Erin A; Bushon, Rebecca N; Brady, Amie M G; Williston, Ashley G; Riddell, Kimberly R; Borchardt, Mark A; Spencer, Susan K; Gellner, Terry M

    2012-09-01

    Log removals of bacterial indicators, coliphage, and enteric viruses were studied in three membrane bioreactor (MBR) activated-sludge and two conventional secondary activated-sludge municipal wastewater treatment plants during three recreational seasons (May-Oct.) when disinfection of effluents is required. In total, 73 regular samples were collected from key locations throughout treatment processes: post-preliminary, post-MBR, post-secondary, post-tertiary, and post-disinfection (UV or chlorine). Out of 19 post-preliminary samples, adenovirus by quantitative polymerase chain reaction (qPCR) was detected in all 19, enterovirus by quantitative reverse transcription polymerase chain reaction (qRT-PCR) was detected in 15, and norovirus GI by qRT-PCR was detected in 11. Norovirus GII and Hepatitis A virus were not detected in any samples, and rotavirus was detected in one sample but could not be quantified. Although culturable viruses were found in 12 out of 19 post-preliminary samples, they were not detected in any post-secondary, post-MBR, post-ultraviolet, or post-chlorine samples. Median log removals for all organisms were higher for MBR secondary treatment (3.02 to >6.73) than for conventional secondary (1.53-4.19) treatment. Ultraviolet disinfection after MBR treatment provided little additional log removal of any organism except for somatic coliphage (>2.18), whereas ultraviolet or chlorine disinfection after conventional secondary treatment provided significant log removals (above the analytical variability) of all bacterial indicators (1.18-3.89) and somatic and F-specific coliphage (0.71 and >2.98). Median log removals of adenovirus across disinfection were low in both MBR and conventional secondary plants (no removal detected and 0.24), and few removals of individual samples were near or above the analytical variability of 1.2 log genomic copies per liter. Based on qualitative examinations of plots showing reductions of organisms throughout treatment

  2. [Analysis of Pathogenic Bacteria in Reclaimed Water and Impact of UV Disinfection on the Removal of Pathogenic Bacteria].

    PubMed

    Jing, Ming; Wang, Lei

    2016-02-15

    In the study, 454-pyrosequencing technology was employed to investigate the species of pathogenic bacteria and the proportion of each pathogen in secondary effluent. Culture-based, qPCR and Q-RT-PCR methods were employed to analyze the removal of indicator (E. coli) and pathogen (Salmonella and Mycobacterium) by ultraviolet (UV) disinfection at a dose of 60 mJ x Cm(-2). The results showed that 11 kinds of pathogenic bacteria were found and the most abundant potentially pathogenic bacteria in the secondary effluent were affiliated with the genera of Clostridium (2.96%), Arcobacter (0.82%) and Mycobacterium (0.36%). 99.9% of culturable E. coli and Salmonella were removed by UV disinfection (60 mJ x cm(-2), however, less than 90% of culturable Mycobacterium were removed. The removal efficiencies of viable E. coli, Salmonella and Mycobacterium were low. Q-RT-PCR seemed to be a promising method for evaluating viable microorganisms in samples. Besides, pathogenic bacteria entered into VBNC state at a UV dose of 60 mJ x cm(-2). Other advanced treatment processes were needed to ensure safe utilization of reclaimed water. PMID:27363153

  3. [Analysis of Pathogenic Bacteria in Reclaimed Water and Impact of UV Disinfection on the Removal of Pathogenic Bacteria].

    PubMed

    Jing, Ming; Wang, Lei

    2016-02-15

    In the study, 454-pyrosequencing technology was employed to investigate the species of pathogenic bacteria and the proportion of each pathogen in secondary effluent. Culture-based, qPCR and Q-RT-PCR methods were employed to analyze the removal of indicator (E. coli) and pathogen (Salmonella and Mycobacterium) by ultraviolet (UV) disinfection at a dose of 60 mJ x Cm(-2). The results showed that 11 kinds of pathogenic bacteria were found and the most abundant potentially pathogenic bacteria in the secondary effluent were affiliated with the genera of Clostridium (2.96%), Arcobacter (0.82%) and Mycobacterium (0.36%). 99.9% of culturable E. coli and Salmonella were removed by UV disinfection (60 mJ x cm(-2), however, less than 90% of culturable Mycobacterium were removed. The removal efficiencies of viable E. coli, Salmonella and Mycobacterium were low. Q-RT-PCR seemed to be a promising method for evaluating viable microorganisms in samples. Besides, pathogenic bacteria entered into VBNC state at a UV dose of 60 mJ x cm(-2). Other advanced treatment processes were needed to ensure safe utilization of reclaimed water.

  4. UV/TiO2 photocatalytic disinfection of carbon-bacteria complexes in activated carbon-filtered water: Laboratory and pilot-scale investigation.

    PubMed

    Zhao, Jin Hui; Chen, Wei; Zhao, Yaqian; Liu, Cuiyun; Liu, Ranbin

    2015-01-01

    The occurrence of carbon-bacteria complexes in activated carbon filtered water has posed a public health problem regarding the biological safety of drinking water. The application of combined process of ultraviolet radiation and nanostructure titanium dioxide (UV/TiO2) photocatalysis for the disinfection of carbon-bacteria complexes were assessed in this study. Results showed that a 1.07 Lg disinfection rate can be achieved using a UV dose of 20 mJ cm(-2), while the optimal UV intensity was 0.01 mW cm(-2). Particle sizes ≥8 μm decreased the disinfection efficiency, whereas variation in particle number in activated carbon-filtered water did not significantly affect the disinfection efficiency. Photoreactivation ratio was reduced from 12.07% to 1.69% when the UV dose was increased from 5 mJ cm(-2) to 20 mJ cm(-2). Laboratory and on-site pilot-scale experiments have demonstrated that UV/TiO2 photocatalytic disinfection technology is capable of controlling the risk posed by carbon-bacteria complexes and securing drinking water safety.

  5. Pulsed UV-C disinfection of Escherichia coli with light-emitting diodes, emitted at various repetition rates and duty cycles.

    PubMed

    Wengraitis, Stephen; McCubbin, Patrick; Wade, Mary Margaret; Biggs, Tracey D; Hall, Shane; Williams, Leslie I; Zulich, Alan W

    2013-01-01

    A 2010 study exposed Staphylococcus aureus to ultraviolet (UV) radiation and thermal heating from pulsed xenon flash lamps. The results suggested that disinfection could be caused not only by photochemical changes from UV radiation, but also by photophysical stress damage caused by the disturbance from incoming pulses. The study called for more research in this area. The recent advances in light-emitting diode (LED) technology include the development of LEDs that emit in narrow bands in the ultraviolet-C (UV-C) range (100-280 nm), which is highly effective for UV disinfection of organisms. Further, LEDs would use less power, and allow more flexibility than other sources of UV energy in that the user may select various pulse repetition frequencies (PRFs), pulse irradiances, pulse widths, duty cycles and types of waveform output (e.g. square waves, sine waves, triangular waves, etc.). Our study exposed Escherichia coli samples to square pulses of 272 nm radiation at various PRFs and duty cycles. A statistically significant correlation was found between E. coli's disinfection sensitivity and these parameters. Although our sample size was small, these results show promise and are worthy of further investigation. Comparisons are also made with pulsed disinfection by LEDs emitting at 365 nm, and pulsed disinfection by xenon flash lamps.

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

    PubMed

    Zyara, Alyaa M; Torvinen, Eila; Veijalainen, Anna-Maria; Heinonen-Tanski, Helvi

    2016-08-01

    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, and a combined chlorine/ultraviolet irradiation treatment for the chlorine-resistant coliphages. Chlorine disinfection with 0.3-0.5 mg/L total chlorine (free Cl-dosage 0.12-0.21 mg/L) for 10 min achieved 2.5-5.7 Log10-reductions for 11 sensitive coliphages. The six most resistant coliphages showed no reduction with these chlorine concentrations. MS2 was intermediate in chlorine resistance, and thus it is not a good indicator for viruses in chlorine disinfection. In the combined treatment total chlorine of 0.05-0.25 mg/L (free Cl-dosage 0.02-0.08 mg/L) and ultraviolet irradiation (14-22 mWs/cm(2)) were more effective than chlorine alone, and 3-5 Log10-reductions were achieved for the chlorine-resistant strains. The chlorination efficiency could be increased by higher dosages and longer contact times, but this could increase the formation of disinfection by-products. Therefore, the combination treatment is a recommended disinfection method. PMID:27441859

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

    PubMed

    Zyara, Alyaa M; Torvinen, Eila; Veijalainen, Anna-Maria; Heinonen-Tanski, Helvi

    2016-08-01

    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, and a combined chlorine/ultraviolet irradiation treatment for the chlorine-resistant coliphages. Chlorine disinfection with 0.3-0.5 mg/L total chlorine (free Cl-dosage 0.12-0.21 mg/L) for 10 min achieved 2.5-5.7 Log10-reductions for 11 sensitive coliphages. The six most resistant coliphages showed no reduction with these chlorine concentrations. MS2 was intermediate in chlorine resistance, and thus it is not a good indicator for viruses in chlorine disinfection. In the combined treatment total chlorine of 0.05-0.25 mg/L (free Cl-dosage 0.02-0.08 mg/L) and ultraviolet irradiation (14-22 mWs/cm(2)) were more effective than chlorine alone, and 3-5 Log10-reductions were achieved for the chlorine-resistant strains. The chlorination efficiency could be increased by higher dosages and longer contact times, but this could increase the formation of disinfection by-products. Therefore, the combination treatment is a recommended disinfection method.

  8. Changes in dissolved organic matter fluorescence and disinfection byproduct formation from UV and subsequent chlorination/chloramination.

    PubMed

    Lyon, Bonnie A; Cory, Rose M; Weinberg, Howard S

    2014-01-15

    Ultraviolet (UV) irradiation is being increasingly used to help drinking water utilities meet finished water quality regulations, but its influence on disinfection byproduct (DBP) precursors and DBP formation is not completely understood. This study investigated the effect of medium pressure (MP) UV combined with chlorination/chloramination on the fluorescent fraction of dissolved organic matter (DOM) isolated from a United States surface water with median total organic carbon content. Parallel factor analysis was used to understand how UV may alter the capacity of DOM to form DBPs of potential human health concern. The production of chloral hydrate and cyanogen chloride from MP UV followed by chlorine or chloramine, respectively, correlated with a decrease in fluorescence intensity of a protein/tryptophan-like component (R(2)=0.79-0.99) and a humic-like component (R(2)=0.91-1.00). This suggests that the UV-induced precursors to these compounds originated from DOM with similar characteristics to these components. The fluorescent DOM components identified in this study are similar to reoccurring components that have been previously identified in a range of raw and treated waters, and this work demonstrates the value of using fluorescence analysis of DOM to understand the relationships between DOM source and DBP formation under a range of treatment conditions.

  9. Micro-organism re-growth in wastewater disinfected by UV radiation and ozone: a micro-biological study.

    PubMed

    Alonso, E; Santos, A; Riesco, P

    2004-04-01

    A series of disinfection experiments using UV radiation and ozone was performed on the secondary effluent from a wastewater treatment plant at a pilot plant scale. The microbial population in the inflowing wastewater and the treated outflow water were quantified for each of the treatment modules (fecal coliforms, fecal streptococci, Salmonella spp. (presence/absence), Clostridium Sulphite-reducers, Pseudomonas aeruginosa, Staphylococcus aureus, coliphages, nematodes, intestinal nematodes and pathogenic fungi). Treated water was stored in opaque tanks at a temperature between 20 and 22 degrees C, after which, a one-month study of the regrowth of the bacterial flora, nematodes and fungi was carried out. Clostridium Sulphite-reducers, pathogenic fungi and nematodes were the micro-organisms showing a greatest degree of resistence to UV- and Ozone-treatment. It was only concerning Clostridium and Pseudomonas abatement that significant elimination results were achieved with both technologies.

  10. Solar disinfection of drinking water (SODIS): an investigation of the effect of UV-A dose on inactivation efficiency.

    PubMed

    Ubomba-Jaswa, Eunice; Navntoft, Christian; Polo-López, M Inmaculada; Fernandez-Ibáñez, Pilar; McGuigan, Kevin G

    2009-05-01

    The effect of solar UV-A irradiance and solar UV-A dose on the inactivation of Escherichia coli K-12 using solar disinfection (SODIS) was studied. E. coli K-12 was seeded in natural well-water contained in borosilicate glass tubes and exposed to sunlight at different irradiances and doses of solar UV radiation. In addition, E. coli K-12 was also inoculated into poly(ethylene) terephthalate (PET) bottles and in a continuous flow system (10 L min(-1)) to determine the effect of an interrupted and uninterrupted solar dose on inactivation. Results showed that inactivation from approximately 10(6) CFU mL(-1) to below the detection level (4 CFU/mL) for E. coli K-12, is a function of the total uninterrupted dose delivered to the bacteria and that the minimum dose should be >108 kJ m(-2) for the conditions described (spectral range of 0.295-0.385 microm). For complete inactivation to below the limit of detection, this dose needs to be received regardless of the incident solar UV intensity and needs to be delivered in a continuous and uninterrupted manner. This is illustrated by a continuous flow system in which bacteria were not fully inactivated (residual viable concentration approximately 10(2) CFU/mL) even after 5 h of exposure to strong sunlight and a cumulative dose of >108 kJ m(-2). This has serious implications for attempts to scale-up solar disinfection through the use of re-circulatory continuous flow reactors.

  11. Multiple transformation pathways of p-arsanilic acid to inorganic arsenic species in water during UV disinfection.

    PubMed

    Li, Suqi; Xu, Jing; Chen, Wei; Yu, Yingtan; Liu, Zizheng; Li, Jinjun; Wu, Feng

    2016-09-01

    p-Arsanilic acid (p-ASA) is widely used in China as livestock and poultry feed additive for promoting animal growth. The use of organoarsenics poses a potential threat to the environment because it is mostly excreted by animals in its original form and can be transformed by UV-Vis light excitation. This work examined the initial rate and efficiency of p-ASA phototransformation under UV-C disinfection lamp. Several factors influencing p-ASA phototransformation, namely, pH, initial concentration, temperature, as well as the presence of NaCl, NH4(+), and humic acid, were investigated. Quenching experiments and LC-MS were performed to investigate the mechanism of p-ASA phototransformation. Results show that p-ASA was decomposed to inorganic arsenic (including As(III) and As(V)) and aromatic products by UV-C light through direct photolysis and indirect oxidation. The oxidation efficency of p-ASA by direct photosis was about 32%, and those by HO and (1)O2 were 19% and 49%, respectively. Cleavage of the arsenic-benzene bond through direct photolysis, HO oxidation or (1)O2 oxidation results in simultaneous formation of inorganic As(III), As(IV), and As(V). Inorganic As(III) is oxidized to As(IV) and then to As(V) by (1)O2 or HO. As(IV) can undergo dismutation or simply react with oxygen to produce As(V) as well. Reactions of the organic moieties of p-ASA produce aniline, aminophenol and azobenzene derivatives as main products. The photoconvertible property of p-ASA implies that UV disinfection of wastewaters from poultry and swine farms containing p-ASA poses a potential threat to the ecosystem, especially agricultural environments.

  12. Multiple transformation pathways of p-arsanilic acid to inorganic arsenic species in water during UV disinfection.

    PubMed

    Li, Suqi; Xu, Jing; Chen, Wei; Yu, Yingtan; Liu, Zizheng; Li, Jinjun; Wu, Feng

    2016-09-01

    p-Arsanilic acid (p-ASA) is widely used in China as livestock and poultry feed additive for promoting animal growth. The use of organoarsenics poses a potential threat to the environment because it is mostly excreted by animals in its original form and can be transformed by UV-Vis light excitation. This work examined the initial rate and efficiency of p-ASA phototransformation under UV-C disinfection lamp. Several factors influencing p-ASA phototransformation, namely, pH, initial concentration, temperature, as well as the presence of NaCl, NH4(+), and humic acid, were investigated. Quenching experiments and LC-MS were performed to investigate the mechanism of p-ASA phototransformation. Results show that p-ASA was decomposed to inorganic arsenic (including As(III) and As(V)) and aromatic products by UV-C light through direct photolysis and indirect oxidation. The oxidation efficency of p-ASA by direct photosis was about 32%, and those by HO and (1)O2 were 19% and 49%, respectively. Cleavage of the arsenic-benzene bond through direct photolysis, HO oxidation or (1)O2 oxidation results in simultaneous formation of inorganic As(III), As(IV), and As(V). Inorganic As(III) is oxidized to As(IV) and then to As(V) by (1)O2 or HO. As(IV) can undergo dismutation or simply react with oxygen to produce As(V) as well. Reactions of the organic moieties of p-ASA produce aniline, aminophenol and azobenzene derivatives as main products. The photoconvertible property of p-ASA implies that UV disinfection of wastewaters from poultry and swine farms containing p-ASA poses a potential threat to the ecosystem, especially agricultural environments. PMID:27593271

  13. Process Requirements for Achieving Full-Flow Disinfection of Recirculating Water Using Ozonation and UV Irradiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A continuous water disinfection process can be used to prevent the introduction and accumulation of obligate and opportunistic fish pathogens in recirculating aquaculture systems (RAS), especially during a disease outbreak when the causative agent would otherwise proliferate within the system. To p...

  14. Exploring the potential synergistic effects of chemical disinfectants and UV on the inactivation of free-living bacteria and treatment of biofilms in a pilot-scale system.

    PubMed

    Vankerckhoven, E; Verbessem, B; Crauwels, S; Declerck, P; Muylaert, K; Willems, K A; Rediers, H

    2011-01-01

    The main objective of this study is to explore possible synergistic or additive effects of combinations of chemical disinfectants (sodium hypochlorite, peracetic acid, hydrogen peroxide, chlorine dioxide) and UV in their efficacy in inactivating free-living bacteria and removing biofilms. In contrast to most studies, this study examines disinfection of municipal water in a pilot-scale system using a mixed bacterial suspension, which enables a better simulation of the conditions encountered in actual industrial environments. It was shown that the combination of either hypochlorite, hydrogen peroxide, peracetic acid, or chlorine dioxide with UV yielded additive effects on the inactivation of free-living bacteria. Actual synergy was observed for the combination of UV and 5 ppm hydrogen peroxide. Regarding biofilm treatment, additive effects were observed using the combination of hydrogen peroxide and UV. The promising results obtained in this study indicate that the combination of UV and chemical disinfectants can considerably reduce the amount of chemicals required for the effective disinfection and treatment of biofilms.

  15. Tracing nitrogenous disinfection byproducts after medium pressure UV water treatment by stable isotope labeling and high resolution mass spectrometry.

    PubMed

    Kolkman, Annemieke; Martijn, Bram J; Vughs, Dennis; Baken, Kirsten A; van Wezel, Annemarie P

    2015-04-01

    Advanced oxidation processes are important barriers for organic micropollutants (e.g., pharmaceuticals, pesticides) in (drinking) water treatment. Studies indicate that medium pressure (MP) UV/H2O2 treatment leads to a positive response in Ames mutagenicity tests, which is then removed after granulated activated carbon (GAC) filtration. The formed potentially mutagenic substances were hitherto not identified and may result from the reaction of photolysis products of nitrate with (photolysis products of) natural organic material (NOM). In this study we present an innovative approach to trace the formation of disinfection byproducts (DBPs) of MP UV water treatment, based on stable isotope labeled nitrate combined with high resolution mass spectrometry. It was shown that after MP UV treatment of artificial water containing NOM and nitrate, multiple nitrogen containing substances were formed. In total 84 N-DBPs were detected at individual concentrations between 1 to 135 ng/L bentazon-d6 equivalents, with a summed concentration of 1.2 μg/L bentazon-d6 equivalents. The chemical structures of three byproducts were confirmed. Screening for the 84 N-DBPs in water samples from a full-scale drinking water treatment plant based on MP UV/H2O2 treatment showed that 22 of the N-DBPs found in artificial water were also detected in real water samples.

  16. Antibiotic resistance spread potential in urban wastewater effluents disinfected by UV/H2O2 process.

    PubMed

    Ferro, Giovanna; Guarino, Francesco; Castiglione, Stefano; Rizzo, Luigi

    2016-08-01

    Urban wastewater treatment plants (UWTPs) are among the main hotspots of antibiotic resistance (AR) spread into the environment and the role of conventional and new disinfection processes as possible barrier to minimise the risk for AR transfer is presently under investigation. Accordingly, the aim of this work was to evaluate the effect of an advanced oxidation process (AOP) (specifically UV/H2O2) on AR transfer potential. UV/H2O2 disinfection experiments were carried out on real wastewater samples to evaluate the: i) inactivation of total coliforms, Escherichia coli and antibiotic resistant E. coli as well as ii) possible removal of target antibiotic resistance genes (ARGs) (namely, blaTEM, qnrS and tetW). In particular, DNA was extracted from both antibiotic resistant E. coli bacterial cells (intracellular DNA), grown on selective culture media, and the whole water suspension (total DNA) collected at different treatment times. Polymerase chain reaction (PCR) assay was performed to detect the absence/presence of the selected ARGs. Real Time quantitative Polymerase Chain Reaction (qPCR) was used to quantify the investigated ARGs in terms of copiesmL(-1). In spite of the bacterial inactivation and a decrease of ARGs in intracellular DNA after 60min treatment, UV/H2O2 process was not effective in ARGs removal from water suspension (total DNA). Particularly, an increase up to 3.7×10(3)copiesmL(-1) (p>0.05) of blaTEM gene was observed in total DNA after 240min treatment, while no difference (p>0.05) was found for qnrS gene between the initial (5.1×10(4)copiesmL(-1)) and the final sample (4.3×10(4)copiesmL(-1)). On the base of the achieved results, the investigated disinfection process may not be effective in minimising AR spread potential into the environment. The death of bacterial cells, which results in DNA release in the treated water, may pose a risk for AR transfer to other bacteria present in the receiving water body.

  17. Does UV disinfection compromise sutures? An evaluation of tissue response and suture retention in salmon surgically implanted with transmitters

    SciTech Connect

    Walker, Ricardo W.; Brown, Richard S.; Deters, Katherine A.; Eppard, M. B.; Cooke, Steven J.

    2013-10-01

    Ultraviolet radiation (UVR) can be used as a tool to disinfect surgery tools used for implanting transmitters into fish. However, the use of UVR could possibly degrade monofilament suture material used to close surgical incisions. This research examined the effect of UVR on monofilament sutures to determine if they were compromised and negatively influenced tag and suture retention, incision openness, or tissue reaction. Eighty juvenile Chinook salmon Oncorhynchus tshawytscha were surgically implanted with an acoustic transmitter and a passive integrated transponder. The incision was closed with a single stitch of either a suture exposed to 20 doses of UV radiation (5 minute duration per dose) or a new, sterile suture. Fish were then held for 28 d and examined under a microscope at day 7, 14, 21 and 28 for incision openness, ulceration, redness, and the presence of water mold. There was no significant difference between treatments for incision openness, redness, ulceration or the presence of water mold on any examination day. On day 28 post-surgery, there were no lost sutures; however, 2 fish lost their transmitters (one from each treatment). The results of this study do not show any differences in negative influences such as tissue response, suture retention or tag retention between a new sterile suture and a suture disinfected with UVR.

  18. Mutagenic activity associated with by-products of drinking water disinfection by chlorine, chlorine dioxide, ozone and UV-irradiation.

    PubMed

    Zoeteman, B C; Hrubec, J; de Greef, E; Kool, H J

    1982-12-01

    A retrospective epidemiological study in The Netherlands showed a statistical association between chlorination by-products in drinking water and cancer of the esophagus and stomach for males. A pilot-plant study with alternative disinfectants was carried out with stored water of the Rivers Rhine and Meuse. It was demonstrated that the increase of direct acting mutagens after treatment with chlorine dioxide is similar to the effect of chlorination. Ozonation of Rhine water reduced the mutagenic activity for Salmonella typhimurium TA 98 both with and without metabolic activation. UV alone hardly affects the mutagenicity of the stored river water for S. typh. TA 98. In all studies, practically no mutagenic activity for S. typh. TA 100 was found. Although remarkable changes in the concentration of individual organic compounds are reported, the identity of the mutagens detected is yet unclear. Compounds of possible interest due to their removal by ozonation are 1,3,3-trimethyloxindole, dicyclopentadiene and several alkylquinolines. Compounds which might be responsible for the increased mutagenicity after chlorination are two brominated acetonitriles and tri(2-chlorethyl) phosphate. Furthermore, the concentration procedure with adsorption on XAD resin and the subsequent elution step may have affected the results. It is proposed to focus further research more on the less volatile by-products of disinfection than on the trihalomethanes.

  19. UV-laser-based longitudinal illuminated diffuser (LID) incorporating diffractive and Lambertian reflectance for the disinfection of beverages

    NASA Astrophysics Data System (ADS)

    Lizotte, Todd

    2010-08-01

    A novel laser beam shaping system was designed to demonstrate the potential of using high power UV laser sources for large scale disinfection of liquids used in the production of food products, such as juices, beer, milk and other beverage types. The design incorporates a patented assembly of optical components including a diffractive beam splitting/shaping element and a faceted pyramidal or conically shaped Lambertian diffuser made from a compression molded PTFE compounds. When properly sintered to an appropriate density, as an example between 1.10 and 1.40 grams per cubic centimeter, the compressed PTFE compounds show a ~99% reflectance at wavelengths ranging from 300 nm to 1500 nm, and a ~98.5% refection of wavelengths from 250 nm to 2000 nm [1]. The unique diffuser configuration also benefits from the fact that the PTFE compounds do not degrade when exposed to ultraviolet radiation as do barium sulfate materials and silver or aluminized mirror coatings [2]. These components are contained within a hermetically sealed quartz tube. Once assembled a laser beam is directed through one end of the tube. This window takes the form of a computer generated diffractive splitter or other diffractive shaper element to split the laser beam into a series of spot beamlets, circular rings or other geometric shapes. As each of the split beamlets or rings cascade downward, they illuminate various points along the tapered PTFE cone or faceted pyramidal form. As they strike the surface they each diffuse in a Lambertian reflectance pattern creating a pseudo-uniform circumferential illuminator along the length of the quartz tube enclosing the assembly. The compact tubular structure termed Longitudinal Illuminated Diffuser (LID) provides a unique UV disinfection source that can be placed within a centrifugal reactor or a pipe based reactor chamber. This paper will review the overall design principle, key component design parameters, preliminary analytic and bench operational testing

  20. Genotoxic response of Austrian groundwater samples treated under standardized UV (254 nm)--disinfection conditions in a combination of three different bioassays.

    PubMed

    Haider, Thomas; Sommer, Regina; Knasmüller, Siefried; Eckl, Peter; Pribil, Walter; Cabaj, Alexander; Kundi, Michael

    2002-01-01

    Ground water samples from different geographic areas in Austria, with different amounts of natural and anthropogenic organic compounds were treated with a standardized low pressure UV (254 nm)-irradiation laboratory flow-through system (UV fluence: 800 J/m2). The genotoxic activities of the water samples before and after the UV disinfection were investigated using a combination of three different bioassays which complement each other with regard to their sensitivity detecting different genotoxins. The test battery comprises the Salmonella/microsome assay (Ames test with TA98. TA 100 and TA 102, with and without S9 mix) and two micronucleus tests with the plant Tradescantia (clone #4430) and with primary rat hepatocytes. Overall, the tested Austrian groundwater samples used for human consumption caused only weak genotoxic activities compared to drinking water samples reported from other countries under similar experimental conditions. With the exception of one weak positive result in the Ames test (only in strain TA98 without S9 mix) with an induction factor of 1.9) all samples after UV disinfection were devoid of additional mutagenic and clastogenic activities compared to the samples before UV disinfection.

  1. Inactivation of antibiotic resistance genes in municipal wastewater effluent by chlorination and sequential UV/chlorination disinfection.

    PubMed

    Zhang, Yingying; Zhuang, Yao; Geng, Jinju; Ren, Hongqiang; Zhang, Yan; Ding, Lili; Xu, Ke

    2015-04-15

    This study investigated disinfection methods including chlorination, ultraviolet (UV) irradiation and sequential UV/chlorination treatment on the inactivation of antibiotic resistance genes (ARGs). ARGs including sul1, tetX, tetG, intI1, and 16S rRNA genes in municipal wastewater treatment plant (MWTP) effluent were examined. The results indicated a positive correlation between the removal of ARGs and chlorine dosage (p=0.007-0.014, n=6),as well as contact time (p=0.0001, n=10). Greater free chlorine (FC) dosage leads to higher removal for all the genes and the maximum removal (1.30-1.49 logs) could be achieved at FC dosage of 30 mg L(-1). The transformation kinetic data for ARGs removal (log C0/C) followed the second-order reaction kinetic model with FC dosage (R(2)=0.6829-0.9999) and contact time (R(2)=0.7353-8634), respectively. Higher ammonia nitrogen (NH3-N) concentration was found to lead to lower removal of ARGs at the same chlorine dosage. When the applied Cl2:NH3-N ratio was over 7.6:1, a significant reduction of ARGs (1.20-1.49 logs) was achieved. By using single UV irradiation, the log removal values of tetX and 16Ss rRNA genes were 0.58 and 0.60, respectively, while other genes were 0.36-0.40 at a fluence of 249.5 mJ cm(-2), which was observed to be less effective than chlorination. With sequential UV/chlorination treatment, 0.006 to 0.31 log synergy values of target genes were observed under different operation parameters.

  2. Innovative Approach to Validation of Ultraviolet (UV) Reactors for Disinfection in Drinking Water Systems

    EPA Science Inventory

    Slide presentation at Conference: ASCE 7th Civil Engineering Conference in the Asian Region. USEPA in partnership with the Cadmus Group, Carollo Engineers, and other State & Industry collaborators, are evaluating new approaches for validating UV reactors to meet groundwater &...

  3. UV/chlorine process for ammonia removal and disinfection by-product reduction: comparison with chlorination.

    PubMed

    Zhang, Xinran; Li, Weiguang; Blatchley, Ernest R; Wang, Xiaoju; Ren, Pengfei

    2015-01-01

    The combined application of UV irradiation at 254 nm and chlorination (UV/chlorine process) was investigated for ammonia removal in water treatment. The UV/chlorine process led to higher ammonia removal with less chlorine demand, as compared to breakpoint chlorination. Chlorination of NH₃ led to NH₂Cl formation in the first step. The photolysis of NH₂Cl and radical- mediated oxidation of ammonia appeared to represent the main pathways for ammonia removal. The trivalent nitrogen of ammonia was oxidized, presumably by reactions with aminyl radicals and chlorine radicals. Measured products included NO₃⁻and NO₂⁻; it is likely that N₂ and N₂O were also generated. In addition, UV irradiation appeared to have altered the reactivity of NOM toward free chlorine. The UV/chlorine process had lower chlorine demand, less C-DBPs (THMs and HAAs), but more HANs than chlorination. These results indicate that the UV/chlorine process could represent an alternative to conventional breakpoint chlorination for ammonia-containing water, with several advantages in terms of simplicity, short reaction time, and reduced chemical dosage.

  4. Implementing Ultraviolet (UV) Disinfection for Treatment of Groundwater for Small and Medium Sized Utilities - abstract

    EPA Science Inventory

    This presentation will focus on validation testing performed on a three-lamp low-pressure high-output (LPHO) TrojanUVSwiftTM UV reactor using MS2, Bacillus Pumilus, and live adenovirus as the test microbes. An adjustable sensor was used to help determine the optimal sensor locati...

  5. Impact of UV/H2O2 pre-oxidation on the formation of haloacetamides and other nitrogenous disinfection byproducts during chlorination.

    PubMed

    Chu, Wenhai; Gao, Naiyun; Yin, Daqiang; Krasner, Stuart W; Mitch, William A

    2014-10-21

    Haloacetamides (HAcAms), an emerging class of nitrogen-based disinfection byproducts (N-DBPs) of health concern in drinking water, have been found in drinking waters at μg/L levels. However, there is a limited understanding about the formation, speciation, and control of halogenated HAcAms. Higher ultraviolet (UV) doses and UV advanced oxidation (UV/H2O2) processes (AOPs) are under consideration for the treatment of trace organic pollutants. The objective of this study was to examine the potential of pretreatment with UV irradiation, H2O2 oxidation, and a UV/H2O2 AOP for minimizing the formation of HAcAms, as well as other emerging N-DBPs, during postchlorination. We investigated changes in HAcAm formation and speciation attributed to UV, H2O2 or UV/H2O2 followed by the application of free chlorine to quench any excess hydrogen peroxide and to provide residual disinfection. The results showed that low-pressure UV irradiation alone (19.5-585 mJ/cm(2)) and H2O2 preoxidation alone (2-20 mg/L) did not significantly change total HAcAm formation during subsequent chlorination. However, H2O2 preoxidation alone resulted in diiodoacetamide formation in two iodide-containing waters and increased bromine utilization. Alternatively, UV/H2O2 preoxidation using UV (585 mJ/cm(2)) and H2O2 (10 mg/L) doses typically employed for trace contaminant removal controlled the formation of HAcAms and several other N-DBPs in drinking water.

  6. Applicability of integrated cell culture quantitative PCR (ICC-qPCR) for the detection of infectious adenovirus type 2 in UV disinfection studies.

    PubMed

    Ryu, Hodon; Cashdollar, Jennifer L; Fout, G Shay; Schrantz, Karen A; Hayes, Samuel

    2015-01-01

    Practical difficulties of the traditional adenovirus infectivity assay such as intensive labor requirements and longer turnaround period limit the direct use of adenovirus as a testing microorganism for systematic, comprehensive disinfection studies. In this study, we attempted to validate the applicability of integrated cell culture quantitative PCR (ICC-qPCR) as an alternative to the traditional cell culture method with human adenovirus type 2 (HAdV2) in a low-pressure UV disinfection study and to further optimize the procedures of ICC-qPCR for 24-well plate format. The relatively high stability of the hexon gene of HAdV2 was observed after exposure to UV radiation, resulting in a maximum gene copy reduction of 0.5 log10 at 280 mJ cm(-2). Two-day post-inoculation incubation period and a maximum spiking level of 10(5) MPN mL(-1) were selected as optimum conditions of ICC-qPCR with the tested HAdV2. An approximate 1:1 correlation of virus quantities by the traditional and ICC-qPCR cell culture based methods suggested that ICC-qPCR is a satisfactory alternative for practical application in HAdV2 disinfection studies. ICC-qPCR results, coupled with a first-order kinetic model (i.e., the inactivation rate constant of 0.0232 cm(2) mJ(-1)), showed that an UV dose of 172 mJ cm(-2) achieved a 4-log inactivation credit for HAdV2. This estimate is comparable to other studies with HAdV2 and other adenovirus respiratory types. The newly optimized ICC-qPCR shows much promise for further study on its applicability of other slow replicating viruses in disinfection studies.

  7. Simultaneous degradation of disinfection byproducts and earthy-musty odorants by the UV/H2O2 advanced oxidation process.

    PubMed

    Jo, Chang Hyun; Dietrich, Andrea M; Tanko, James M

    2011-04-01

    Advanced treatment technologies that control multiple contaminants are beneficial to drinking water treatment. This research applied UV/H(2)O(2) for the simultaneous degradation of geosmin, 2-methylisoborneol, four trihalomethanes and six haloacetic acids. Experiments were conducted in de-ionized water at 24 ± 1.0 °C with ng/L amounts of odorants and μg/L amounts of disinfection byproducts. UV was applied with and without 6 mg/L H(2)O(2.) The results demonstrated that brominated trihalomethanes and brominated haloacetic acids were degraded to a greater extent than geosmin and 2-methylisoborneol. Tribromomethane and dibromochloromethane were degraded by 99% and 80% respectively at the UV dose of 1200 mJ/cm(2) with 6 mg/L H(2)O(2), whereas 90% of the geosmin and 60% of the 2-methylisoborneol were removed. Tribromoacetic acid and dibromoacetic acid were degraded by 99% and 80% respectively under the same conditions. Concentrations of trichloromethane and chlorinated haloacetic acids were not substantially reduced under these conditions and were not effectively removed at doses designed to remove geosmin and 2-methylisoborneol. Brominated compounds were degraded primarily by direct photolysis and cleavage of the C-Br bond with pseudo first order rate constants ranging from 10(-3) to 10(-2) s(-1). Geosmin and 2-methylisoborneol were primarily degraded by reaction with hydroxyl radical with direct photolysis as a minor factor. Perchlorinated disinfection byproducts were degraded by reaction with hydroxyl radicals. These results indicate that the UV/H(2)O(2) can be applied to effectively control both odorants and brominated disinfection byproducts.

  8. Synergistic effect of sequential or combined use of ozone and UV radiation for the disinfection of Bacillus subtilis spores.

    PubMed

    Jung, Yeon Jung; Oh, Byung Soo; Kang, Joon-Wun

    2008-03-01

    This study was performed to evaluate the inactivation efficiency or synergy of combined ozone and UV processes (combined ozone/UV process) or sequential processes (ozone-UV, UV-ozone) compared with individual unit processes and to investigate the specific roles of ozone, UV and the hydroxyl radical, which is formed as an intermediate in the combined ozone/UV process. The Bacillus subtilis spore, which has often been used as a surrogate microorganism for Cryptosporidium parvum oocysts, was used as a target microorganism. Compared to individual unit processes with ozone or UV, the inactivation of B. subtilis spores by the combined ozone/UV process was enhanced under identical conditions. To investigate the specific roles of ozone and UV in the combined ozone/UV process, sequential ozone-UV and UV-ozone processes were tested for degrees of inactivation. Additionally, the experiment was performed in the presence and absence of tert-butyl alcohol, which acted as a hydroxyl radical scavenger to assess the role of inactivation by the hydroxyl radical in the combined ozone/UV process. Among the five candidate processes, the greatest synergistic effect was observed in the combined ozone/UV process. From the comparison of five candidate processes, the hydroxyl radical and ozone were each determined to significantly enhance the overall inactivation efficiency in the combined ozone/UV process. PMID:18028981

  9. Synergistic effect of sequential or combined use of ozone and UV radiation for the disinfection of Bacillus subtilis spores.

    PubMed

    Jung, Yeon Jung; Oh, Byung Soo; Kang, Joon-Wun

    2008-03-01

    This study was performed to evaluate the inactivation efficiency or synergy of combined ozone and UV processes (combined ozone/UV process) or sequential processes (ozone-UV, UV-ozone) compared with individual unit processes and to investigate the specific roles of ozone, UV and the hydroxyl radical, which is formed as an intermediate in the combined ozone/UV process. The Bacillus subtilis spore, which has often been used as a surrogate microorganism for Cryptosporidium parvum oocysts, was used as a target microorganism. Compared to individual unit processes with ozone or UV, the inactivation of B. subtilis spores by the combined ozone/UV process was enhanced under identical conditions. To investigate the specific roles of ozone and UV in the combined ozone/UV process, sequential ozone-UV and UV-ozone processes were tested for degrees of inactivation. Additionally, the experiment was performed in the presence and absence of tert-butyl alcohol, which acted as a hydroxyl radical scavenger to assess the role of inactivation by the hydroxyl radical in the combined ozone/UV process. Among the five candidate processes, the greatest synergistic effect was observed in the combined ozone/UV process. From the comparison of five candidate processes, the hydroxyl radical and ozone were each determined to significantly enhance the overall inactivation efficiency in the combined ozone/UV process.

  10. The effect of UV/H2O2 treatment on disinfection by-product formation potential under simulated distribution system conditions.

    PubMed

    Metz, D H; Meyer, M; Dotson, A; Beerendonk, E; Dionysiou, D D

    2011-07-01

    Advanced oxidation with ultraviolet light and hydrogen peroxide (UV/H(2)O(2)) produces hydroxyl radicals that have the potential to degrade a wide-range of organic micro-pollutants in water. Yet, when this technology is used to reduce target contaminants, natural organic matter can be altered. This study evaluated disinfection by-product (DBP) precursor formation for UV/H(2)O(2) while reducing trace organic contaminants in natural water (>90% for target pharmaceuticals, pesticides and taste and odor producing compounds and 80% atrazine degradation). A year-long UV/H(2)O(2) pilot study was conducted to evaluate DBP precursor formation with varying water quality. The UV pilot reactors were operated to consistently achieve 80% atrazine degradation, allowing comparison of low pressure (LP) and medium pressure (MP) lamp technologies for DBP precursor formation. Two process waters of differing quality were used as pilot influent, i.e., before and after granular activated carbon adsorption. DBP precursors increased under most of the conditions studied. Regulated trihalomethane formation potential increased through the UV/H(2)O(2) reactors from 20 to 118%, depending on temperature and water quality. When Post-GAC water served as reactor influent, less DBPs were produced in comparison to conventionally treated water. Haloacetic acid (HAA5) increased when conventionally treated water served as UV/H(2)O(2) pilot influent, but only increased slightly (MP lamp) when GAC treated water served as pilot influent. No difference in 3-day simulated distribution system DBP concentration was observed between LP and MP UV reactors when 80% atrazine degradation was targeted.

  11. Disinfection of biologically treated wastewater and prevention of biofouling by UV/electrolysis hybrid technology: influence factors and limits for domestic wastewater reuse.

    PubMed

    Haaken, Daniela; Dittmar, Thomas; Schmalz, Viktor; Worch, Eckhard

    2014-04-01

    Reuse of wastewater contributes significantly to an efficient and sustainable water usage. However, due to the presence of a multitude of pathogens (e.g. bacteria, viruses, worms, protozoa) in secondary effluents, disinfection procedures are indispensable. In decentralized wastewater treatment, UV irradiation represents one of the most common disinfection methods in addition to membrane processes and to a certain extent electrochemical procedures. However, the usage of UV disinfected secondary effluents for domestic (sanitary) or irrigation purposes bears a potential health risk due to the possible photo and dark repair of reversibly damaged bacteria. Against this background, the application of the UV/electrolysis hybrid technology for disinfection and prevention of bacterial reactivation in biologically treated wastewater was investigated in view of relevant influence factors and operating limits. Furthermore, the influence of electrochemically generated total oxidants on the formation of biofilms on quartz glass surfaces was examined, since its preventive avoidance contributes to an enhanced operational safety of the hybrid reactor. It was found that reactivation of bacteria in UV irradiated, biologically treated wastewater can be prevented by electrochemically produced total oxidants. In this regard, the influence of the initial concentration of the microbiological indicator organism Escherichia coli (E. coli) (9.3*10(2)-2.2*10(5) per 100 mL) and the influence of total suspended solids (TSS) in the range of 11-75 mg L(-1) was examined. The concentration of total oxidants necessary for prevention of bacterial regrowth increases linearly with the initial E. coli and TSS concentration. At an initial concentration of 933 E. coli per 100 mL, a total oxidants concentration of 0.4 mg L(-1) is necessary to avoid photo reactivation (at 4200 Lux), whereas 0.67 mg L(-1) is required if the E. coli concentration is enhanced by 2.4 log levels (cTSS = constant = 13 mg

  12. Disinfection of biologically treated wastewater and prevention of biofouling by UV/electrolysis hybrid technology: influence factors and limits for domestic wastewater reuse.

    PubMed

    Haaken, Daniela; Dittmar, Thomas; Schmalz, Viktor; Worch, Eckhard

    2014-04-01

    Reuse of wastewater contributes significantly to an efficient and sustainable water usage. However, due to the presence of a multitude of pathogens (e.g. bacteria, viruses, worms, protozoa) in secondary effluents, disinfection procedures are indispensable. In decentralized wastewater treatment, UV irradiation represents one of the most common disinfection methods in addition to membrane processes and to a certain extent electrochemical procedures. However, the usage of UV disinfected secondary effluents for domestic (sanitary) or irrigation purposes bears a potential health risk due to the possible photo and dark repair of reversibly damaged bacteria. Against this background, the application of the UV/electrolysis hybrid technology for disinfection and prevention of bacterial reactivation in biologically treated wastewater was investigated in view of relevant influence factors and operating limits. Furthermore, the influence of electrochemically generated total oxidants on the formation of biofilms on quartz glass surfaces was examined, since its preventive avoidance contributes to an enhanced operational safety of the hybrid reactor. It was found that reactivation of bacteria in UV irradiated, biologically treated wastewater can be prevented by electrochemically produced total oxidants. In this regard, the influence of the initial concentration of the microbiological indicator organism Escherichia coli (E. coli) (9.3*10(2)-2.2*10(5) per 100 mL) and the influence of total suspended solids (TSS) in the range of 11-75 mg L(-1) was examined. The concentration of total oxidants necessary for prevention of bacterial regrowth increases linearly with the initial E. coli and TSS concentration. At an initial concentration of 933 E. coli per 100 mL, a total oxidants concentration of 0.4 mg L(-1) is necessary to avoid photo reactivation (at 4200 Lux), whereas 0.67 mg L(-1) is required if the E. coli concentration is enhanced by 2.4 log levels (cTSS = constant = 13 mg

  13. ENVIRONMENTAL TECHNOLOGY VERIFICATION: JOINT (NSF-EPA) VERIFICATION STATEMENT AND REPORT; UV DISINFECTION FOR REUSE APPLICATION, AQUIONICS, INC. BERSONINLINE 4250 UV SYSTEM

    EPA Science Inventory

    Verification testing of the Aquionics, Inc. bersonInLine® 4250 UV System to develop the UV delivered dose flow relationship was conducted at the Parsippany-Troy Hills Wastewater Treatment Plant test site in Parsippany, New Jersey. Two full-scale reactors were mounted in series. T...

  14. Field test experience

    NASA Technical Reports Server (NTRS)

    Weaver, R. W.

    1983-01-01

    As a part of the Flat-Plate Solar Array Project (FSA), a field-test program was developed to obtain solar photovoltaic (PV) module performance and endurance data. These data are used to identify the specific characteristics of module designs under various environmental conditions. The information obtained from field testing is useful to all participants in the National Photovoltaics Program, from the research planner to the life-cycle cost analyst.

  15. Ultraviolet disinfection of potable water

    SciTech Connect

    Wolfe, R.L. )

    1990-06-01

    Because of upcoming surface and groundwater regulations regarding the control of microbiological and chemical contaminants, there is a need to evaluate the feasibility and effectiveness of ultraviolet (UV) radiation for primary disinfection of potable water supplies. Data is presented on microbicidal wavelengths of UV and distribution of energy output for low and medium-pressure arc lamps. Both systems were found to perform equally well for inactivating microorganisms, but each had distinct advantages in different applications. Approximate dosages for 90% inactivation of selected microorganisms by UV is presented in a table. Cost analysis for disinfection is presented in two tables as well as the advantages and disadvantages of UV disinfection. 38 refs.

  16. AOPs with ozone and UV radiation in drinking water: contaminants removal and effects on disinfection byproducts formation.

    PubMed

    Collivignarelli, C; Sorlini, S

    2004-01-01

    In this study, the advanced oxidation with ozone and UV radiation (with two low pressure UV lamps, at 254 and 185 nm wavelength) were experimented on a surface water in order to study the removal of two odorous compounds (geosmin and 2-methylisoborneol) and a pesticide (metolachlor), the influence on organic compounds (UV absorbance and THM precursors) and bromate formation. Different batch tests were performed with ozone concentration up to 10 mg/L, UV dose up to 14,000 J/m2 and a maximum contact time of 10 minutes. The main results show that metolachlor can be efficiently removed with ozone alone while for geosmin and MIB a complete removal can be obtained with the advanced oxidation of ozone (with concentration of 1.5-3 mg/L and contact time of 2-3 minutes) with UV radiation (with doses of 5,000-6,000 J/m2). As concerns the influence on the organic precursors, all the experimented processes show a medium removal of about 20-40% for UV absorbance and 15-30% for THMFP (trihalomethanes formation potential). As concerns bromate formation, the advanced oxidation of ozone/UV 254 nm shows a bromate formation that is about 40% lower with respect to conventional oxidation with ozone.

  17. ULTRAVIOLET DISINFECTION STUDIES WITH CCL LISTED MICROORGANISMS

    EPA Science Inventory

    Resistance to ultraviolet (UV) disinfection is an essential aspect regarding all microbial groups listed on the CCL. The U.S. drinking water industry is interested in including UV light treatment as an amendment to conventional treatment for disinfecting water supplies. UV disi...

  18. Disinfection Processes.

    PubMed

    Munakata, Naoko; Kuo, Jeff

    2016-10-01

    A review of the literature published in 2015 on topics relating to disinfection processes is presented. This review is divided into the following sections: disinfection methods, disinfection byproducts, and microbiology and microbial communities. PMID:27620087

  19. Controlling Legionella and Pseudomonas aeruginosa re-growth in therapeutic spas: implementation of physical disinfection treatments, including UV/ultrafiltration, in a respiratory hydrotherapy system.

    PubMed

    Leoni, E; Sanna, T; Zanetti, F; Dallolio, L

    2015-12-01

    The study aimed to assess the efficacy of an integrated water safety plan (WSP) in controlling Legionella re-growth in a respiratory hydrotherapy system located in a spa centre, supplied with sulphurous water, which was initially colonized by Legionella pneumophila. Heterotrophic plate counts, Pseudomonas aeruginosa, Legionella spp. were detected in water samples taken 6-monthly from the hydrotherapy equipment (main circuit, entry to benches, final outlets). On the basis of the results obtained by the continuous monitoring and the changes in conditions, the original WSP, including physical treatments of water and waterlines, environmental surveillance and microbiological monitoring, was integrated introducing a UV/ultrafiltration system. The integrated treatment applied to the sulphurous water (microfiltration/UV irradiation/ultrafiltration), waterlines (superheated stream) and distal outlets (descaling/disinfection of nebulizers and nasal irrigators), ensured the removal of Legionella spp. and P. aeruginosa and a satisfactory microbiological quality over time. The environmental surveillance was successful in evaluating the hazard and identifying the most suitable preventive strategies to avoid Legionella re-growth. Ultrafiltration is a technology to take into account in the control of microbial contamination of therapeutic spas, since it does not modify the chemical composition of the water, thus allowing it to retain its therapeutic properties. PMID:26608761

  20. Controlling Legionella and Pseudomonas aeruginosa re-growth in therapeutic spas: implementation of physical disinfection treatments, including UV/ultrafiltration, in a respiratory hydrotherapy system.

    PubMed

    Leoni, E; Sanna, T; Zanetti, F; Dallolio, L

    2015-12-01

    The study aimed to assess the efficacy of an integrated water safety plan (WSP) in controlling Legionella re-growth in a respiratory hydrotherapy system located in a spa centre, supplied with sulphurous water, which was initially colonized by Legionella pneumophila. Heterotrophic plate counts, Pseudomonas aeruginosa, Legionella spp. were detected in water samples taken 6-monthly from the hydrotherapy equipment (main circuit, entry to benches, final outlets). On the basis of the results obtained by the continuous monitoring and the changes in conditions, the original WSP, including physical treatments of water and waterlines, environmental surveillance and microbiological monitoring, was integrated introducing a UV/ultrafiltration system. The integrated treatment applied to the sulphurous water (microfiltration/UV irradiation/ultrafiltration), waterlines (superheated stream) and distal outlets (descaling/disinfection of nebulizers and nasal irrigators), ensured the removal of Legionella spp. and P. aeruginosa and a satisfactory microbiological quality over time. The environmental surveillance was successful in evaluating the hazard and identifying the most suitable preventive strategies to avoid Legionella re-growth. Ultrafiltration is a technology to take into account in the control of microbial contamination of therapeutic spas, since it does not modify the chemical composition of the water, thus allowing it to retain its therapeutic properties.

  1. LSA field test

    NASA Technical Reports Server (NTRS)

    Jaffe, P.

    1979-01-01

    Degradation tests indicate that electrical degradation is not a slow monotonically increasing phenomenon as originally thought but occurs abruptly as the result of some traumatic event. This finding has led to a change in the test philosophy. A discussion of this change is presented along with a summary of degradation and failure data from all the sites and results from a variety of special tests. New instrumentation for in-field measurements are described. Field testing activity was expanded by the addition of twelve remote sites located as far away as Alaska and the Canal Zone. Descriptions of the new sites are included.

  2. Biofilm and siderophore effects on secondary waste water disinfection.

    PubMed

    Saidi, N; Kouki, S; Mehri, I; Ben Rejeb, A; Belila, A; Hassen, A; Ouzari, H

    2011-10-01

    The efficiency of ultraviolet (UV) light disinfection of wastewater effluent using a large-scale pilot system was studied. The relationship between biofilm and siderophore production and UV doses received by Pseudomonas aeruginosa strain ATCC 15442 was determined. UV decreased pyoverdine production and enhanced biofilm production. Consequently external factors conditioned by both pyoverdine and biofilm may affect the UV effect on bacterial disinfection.

  3. RESOLVE 2010 Field Test

    NASA Technical Reports Server (NTRS)

    Captain, J.; Quinn, J.; Moss, T.; Weis, K.

    2010-01-01

    This slide presentation reviews the field tests conducted in 2010 of the Regolith Environment Science & Oxygen & Lunar Volatile Extraction (RESOLVE). The Resolve program consist of several mechanism: (1) Excavation and Bulk Regolith Characterization (EBRC) which is designed to act as a drill and crusher, (2) Regolith Volatiles Characterization (RVC) which is a reactor and does gas analysis,(3) Lunar Water Resources Demonstration (LWRD) which is a fluid system, water and hydrogen capture device and (4) the Rover. The scientific goal of this test is to demonstrate evolution of low levels of hydrogen and water as a function of temperature. The Engineering goals of this test are to demonstrate:(1) Integration onto new rover (2) Miniaturization of electronics rack (3) Operation from battery packs (elimination of generator) (4) Remote command/control and (5) Operation while roving. Views of the 2008 and the 2010 mechanisms, a overhead view of the mission path, a view of the terrain, the two drill sites, and a graphic of the Master Events Controller Graphical User Interface (MEC GUI) are shown. There are descriptions of the Gas chromatography (GC), the operational procedure, water and hydrogen doping of tephra. There is also a review of some of the results, and future direction for research and tests.

  4. Synergistic effect of heat and solar UV on DNA damage and water disinfection of E. coli and bacteriophage MS2.

    PubMed

    Theitler, Dana Jennifer; Nasser, Abid; Gerchman, Yoram; Kribus, Abraham; Mamane, Hadas

    2012-12-01

    The response of a representative virus and indicator bacteria to heating, solar irradiation, or their combination, was investigated in a controlled solar simulator and under real sun conditions. Heating showed higher inactivation of Escherichia coli compared to the bacteriophage MS2. Heating combined with natural or simulated solar irradiation demonstrated a synergistic effect on the inactivation of E. coli, with up to 3-log difference for 50 °C and natural sun insolation of 2,000 kJ m(-2) (compared to the sum of the separate treatments). Similar synergistic effect was also evident when solar-UV induced DNA damage to E. coli was assessed using the endonuclease sensitive site assay (ESS). MS2 was found to be highly resistant to irradiation and heat, with a slightly synergistic effect observed only at 59 °C and natural sun insolation of 5,580 kJ m(-2). Heat treatment also hindered light-dependent recovery of E. coli making the treatment much more effective.

  5. Disinfection of urban wastewater by solar driven and UV lamp - TiO₂ photocatalysis: effect on a multi drug resistant Escherichia coli strain.

    PubMed

    Rizzo, L; Della Sala, A; Fiorentino, A; Li Puma, G

    2014-04-15

    The effect of TiO₂ photocatalysis on the inactivation of an antibiotic resistant Escherichia coli strain selected from an urban wastewater treatment plant (UWWTP) effluent was investigated. Different light sources including a 250 W wide spectrum lamp, a 125 W UV-A lamp and solar radiation, as well as, photocatalysts loadings (TiO₂ Degussa P25) in the range from 0.05 to 2.00 g TiO₂ L(-1) were evaluated. The higher efficiency (total bacterial inactivation after 10 min of irradiation) was observed in the absence of TiO₂ when the wastewater was irradiated using the 250 W lamp. In the presence of TiO₂ a decreasing inactivation trend was observed (99.76% and 72.22% inactivation after 10 min irradiation at 0.10 and 2.00 g TiO₂ L(-1) respectively). Under solar simulated conditions the highest inactivation efficiency (93.17%) after 10 min of irradiation was achieved at the lower photocatalyst loading (0.05 g TiO₂ L(-1)). The concept of "reactor optical thickness" was introduced to explain the rates of disinfection observed. The optimum photocatalyst loading estimated by radiation absorption-scattering modeling was found to be 0.1 g TiO₂ L(-1) for all lamps. The difference between experimental tests and modeling may be due to TiO₂ particles aggregation. Comparative kinetic tests between solar and solar simulated photocatalytic (SSP) processes using 0.05 g TiO₂ L(-1) in suspension showed a quite similar inactivation behavior up to 30 min of irradiation, but only the SSP process resulted in a total inactivation of bacteria after 60 min of exposure. Antibiotic resistant test (Kirby-Bauer) on survived colonies showed that the SSP and SP processes affected in different ways the resistance of E. coli strain to the target antibiotics.

  6. Disinfection and toxicological assessments of pulsed UV and pulsed-plasma gas-discharge treated-water containing the waterborne protozoan enteroparasite Cryptosporidium parvum.

    PubMed

    Hayes, Jennifer; Kirf, Dominik; Garvey, Mary; Rowan, Neil

    2013-09-01

    We report for the first time on the comparative use of pulsed-plasma gas-discharge (PPGD) and pulsed UV light (PUV) for the novel destruction of the waterborne enteroparasite Cryptosporidium parvum. It also describes the first cyto-, geno- and ecotoxicological assays undertaken to assess the safety of water decontaminated using PPGD and PUV. During PPGD treatments, the application of high voltage pulses (16 kV, 10 pps) to gas-injected water (N2 or O2, flow rate 2.5L/min) resulted in the formation of a plasma that generated free radicals, ultraviolet light, acoustic shock waves and electric fields that killed ca. 4 log C. parvum oocysts in 32 min exposure. Findings showed that PPGD-treated water produced significant cytotoxic properties (as determined by MTT and neutral red assays), genotoxic properties (as determined by comet and Ames assays), and ecotoxic properties (as determined by Microtox™, Thamnotox™ and Daphnotox™ assays) that are representative of different trophic levels in aquatic environment (p<0.05). Depending in part on the type of injected gas used, PPGD-treated water became either alkaline (pH ≤ 8.58, using O2) or acidic (pH ≥ 3.21, using N2) and contained varying levels of reactive free radicals such as ozone (0.8 mg/L) and/or dissociated nitric and nitrous acid that contributed to the observed disinfection and toxicity. Chemical analysis of PPGD-treated water revealed increasing levels of electrode metals that were present at ≤ 30 times the tolerated respective values for EU drinking water. PUV-treated water did not exhibit any toxicity and was shown to be far superior to that of PPGD for killing C. parvum oocysts taking only 90 s of pulsing [UV dose of 6.29 μJ/cm(2)] to produce a 4-log reduction compared to a similar reduction level achieved after 32min PPGD treatment as determined by combined in vitro CaCo-2 cell culture-qPCR.

  7. Guidelines for ultraviolet disinfection of drinking water: considerations for Ontario.

    PubMed

    Hofmann, Ron; Andrews, Bob; Lachmaniuk, Pat

    The Ontario Ministry of the Environment is actively investigating protocols for approving the installation of ultraviolet (UV) disinfection systems for drinking water disinfection. This paper discusses issues that may be considered for selecting the appropriate UV dose, validating UV reactor performance, and monitoring the performance of the reactor once installed.

  8. High-performance, low-cost solar collectors for disinfection of contaminated water.

    PubMed

    Vidal, A; Diaz, A I

    2000-01-01

    Although the germicidal action of sunlight has long been recognized, its potential for practical applications has to be researched more thoroughly. This paper summarizes the progress made toward a commercially practical collector for solar disinfection applications. Nontracking compound parabolic collectors (CPCs), developed originally for capturing solar photons for thermal energy applications, were examined as potential solar photoreactors. A field demonstration of solar disinfection treatment using commercially manufactured solar reactors was conducted. Field tests showed successful destruction of Escherichia coli and Enterococcus faecalis and have provided data for full-scale design of water treatment systems. From above observations, a throughput value of 50 L/m2 h for the low-cost CPC reactor tested was estimated. For a 190 m3/d (0.05 MGD) facility, the estimated total costs for disinfection using UV-A is U.S. $0.19/m3 ($0.70/1000 gal). The use of near-UV sunlight to disinfect water supplies seems promising in rural communities of developing countries where treated water is unavailable.

  9. Investigations of the relationship between use of in vitro cell culture-quantitative PCR and a mouse-based bioassay for evaluating critical factors affecting the disinfection performance of pulsed UV light for treating Cryptosporidium parvum oocysts in saline.

    PubMed

    Garvey, Mary; Farrell, Hugh; Cormican, Martin; Rowan, Neil

    2010-03-01

    Cryptosporidium parvum is an enteric coccidian parasite that is recognised as a frequent cause of water-borne disease in humans. We report for the first time on use of the in vitro HCT-8 cell culture-quantitative PCR (qPCR) assay and the in vivo SCID-mouse bioassay for evaluating critical factors that reduce or eliminate infectivity of C. parvum after irradiating oocysts in saline solution under varying operational conditions with pulsed UV light. Infections post UV treatments were detected by immunofluorescence (IF) microscopy and by quantitative PCR in cell culture, and by IF staining of faeces and by hematoxylin and eosin staining of intestinal villi in mice. There was a good agreement between using cell culture-qPCR and the mouse assay for determining reduction or elimination of C. parvum infectivity as a consequence of varying UV operating conditions. Reduction in infectivity depended on the intensity of lamp discharge energy applied, amount of pulsing and population size of oocysts (P < or = 0.05). Conventional radiometer was unable to measure fluence or UV dose in saline samples due to the ultra-short non-continuous nature of the high-energy light pulses. Incorporation of humic acid at a concentration above that found in surface water (i.e., < or =10 ppm) did not significantly affect PUV disinfection capability irrespective of parameters tested (P < or = 0.05). These observations show that use of this HCT-8 cell culture assay is equivalent to using the 'gold standard' mouse-based infectivity assay for determining disinfection performances of PUV for treating C. parvum in saline solution. PMID:20096310

  10. Micropollutants produced by disinfection of wastewater effluents

    SciTech Connect

    Jolley, R.L.; Cumming, R.B.; Lee, N.E.; Thompson, J.E.; Lewis, L.R.

    1981-01-01

    Recent research conducted with the objective of determining some of the chemical mutagenic characteristics of nonvolatile micropollutants in treated wastewater effluents is summarized. The effluents from nine wastewater plants were examined relative to the chemical effects of the disinfectants chlorine, ozone, and uv light on nonvolatile organic constituents and the formation of mutagenic constituents during disinfection. Results indicate that disinfection by chlorine or ozone can lead to an increase in the number of mutagenic materials in the effluents. (JGB)

  11. Ultraviolet disinfection of contact lenses.

    PubMed

    Harris, M G; Fluss, L; Lem, A; Leong, H

    1993-10-01

    To evaluate the efficacy of ultraviolet (UV) radiation as a method of disinfecting contact lenses and their storage solutions, we contaminated soft lenses (Bausch & Lomb Optima 38), rigid gas permeable (RGP) lenses (Oxyflow F-30), and their storage solutions with three common bacteria. Escherichia coli (E.c.), Staphylococcus epidermis (S.e.), and Serratia marcescens (S.m.). The storage solutions used were saline solution and RGP conditioning solution. We determined the exposure times to 253.7-nm wavelength UV radiation necessary to disinfect the contact lenses and solutions. The decimal reduction values (D values) found for UV radiation were 10 to 200 hundred times shorter than reported for currently available disinfection systems. For E.c., sterilization was attained after 100 s of exposure. For S.e. and S.m., sterilization occurred after 300 s of exposure. Different contact lens solutions transmit UV radiation to various degrees, with saline solution passing more than 90% of the UV radiation. Thus, our results indicate that UV radiation is an effective and rapid method of disinfecting contact lenses and their storage solutions. PMID:8247487

  12. Ultraviolet disinfection of contact lenses.

    PubMed

    Harris, M G; Fluss, L; Lem, A; Leong, H

    1993-10-01

    To evaluate the efficacy of ultraviolet (UV) radiation as a method of disinfecting contact lenses and their storage solutions, we contaminated soft lenses (Bausch & Lomb Optima 38), rigid gas permeable (RGP) lenses (Oxyflow F-30), and their storage solutions with three common bacteria. Escherichia coli (E.c.), Staphylococcus epidermis (S.e.), and Serratia marcescens (S.m.). The storage solutions used were saline solution and RGP conditioning solution. We determined the exposure times to 253.7-nm wavelength UV radiation necessary to disinfect the contact lenses and solutions. The decimal reduction values (D values) found for UV radiation were 10 to 200 hundred times shorter than reported for currently available disinfection systems. For E.c., sterilization was attained after 100 s of exposure. For S.e. and S.m., sterilization occurred after 300 s of exposure. Different contact lens solutions transmit UV radiation to various degrees, with saline solution passing more than 90% of the UV radiation. Thus, our results indicate that UV radiation is an effective and rapid method of disinfecting contact lenses and their storage solutions.

  13. Assessing point-of-use ultraviolet disinfection for safe water in urban developing communities.

    PubMed

    Barstow, Christina K; Dotson, Aaron D; Linden, Karl G

    2014-12-01

    Residents of urban developing communities often have a tap in their home providing treated and sometimes filtered water but its microbial quality cannot be guaranteed. Point-of-use (POU) disinfection systems can provide safe drinking water to the millions who lack access to clean water in urban communities. While many POU systems exist, there are several concerns that can lead to low user acceptability, including low flow rate, taste and odor issues, high cost, recontamination, and ineffectiveness at treating common pathogens. An ultraviolet (UV) POU system was constructed utilizing developing community-appropriate materials and simple construction techniques based around an inexpensive low-wattage, low pressure UV bulb. The system was tested at the bench scale to characterize its hydrodynamic properties and microbial disinfection efficacy. Hydraulically the system most closely resembled a plug flow reactor with minor short-circuiting. The system was challenge tested and validated for a UV fluence of 50 mJ/cm(2) and greater, over varying flow rates and UV transmittances, corresponding to a greater than 4 log reduction of most pathogenic bacteria, viruses, and protozoa of public health concern. This study presents the designed system and testing results to demonstrate the potential architecture of a low-cost, open-source UV system for further prototyping and field-testing.

  14. The North Carolina Field Test

    SciTech Connect

    Sharp, T.R.; Ternes, M.P.

    1990-08-01

    The North Carolina Field Test will test the effectiveness of two weatherization approaches: the current North Carolina Low-Income Weatherization Assistance Program and the North Carolina Field Test Audit. The Field Test Audit will differ from North Carolina's current weatherization program in that it will incorporate new weatherization measures and techniques, a procedure for basing measure selection of the characteristics of the individual house and the cost-effectiveness of the measure, and also emphasize cooling energy savings. The field test will determine the differences of the two weatherization approaches from the viewpoints of energy savings, cost effectiveness, and implementation ease. This Experimental Plan details the steps in performing the field test. The field test will be a group effort by several participating organizations. Pre- and post-weatherization data will be collected over a two-year period (November 1989 through August 1991). The 120 houses included in the test will be divided into a control group and two treatment groups (one for each weatherization procedure) of 40 houses each. Weekly energy use data will be collected for each house representing whole-house electric, space heating and cooling, and water heating energy uses. Corresponding outdoor weather and house indoor temperature data will also be collected. The energy savings of each house will be determined using linear-regression based models. To account for variations between the pre- and post-weatherization periods, house energy savings will be normalized for differences in outdoor weather conditions and indoor temperatures. Differences between the average energy savings of treatment groups will be identified using an analysis of variance approach. Differences between energy savings will be quantified using multiple comparison techniques. 9 refs., 8 figs., 5 tabs.

  15. Computational modeling of ultraviolet disinfection.

    PubMed

    Younis, B A; Yang, T H

    2010-01-01

    The efficient design of ultraviolet light (UV) systems for water and wastewater treatment requires detailed knowledge of the patterns of fluid motion that occur in the disinfection channel. This knowledge is increasingly being obtained using Computational Fluid Dynamics (CFD) software packages that solve the equations governing turbulent fluid-flow motion. In this work, we present predictions of the patterns of flow and the extent of disinfection in a conventional reactor consisting of an open channel with an array of UV lamps placed with their axes perpendicular to the direction of flow. It is shown that the resulting flow is inherently unsteady due to the regular shedding of vortices from the submerged lamps. It is also shown that the accurate prediction of the hydraulic residence time and, consequently, the extent of disinfection is strongly dependent on the ability of the CFD method to capture the occurrence and strength of the vortex shedding, and its effects on the turbulent mixing processes.

  16. CHALLENGES OF COMBINED SEWER OVERFLOW DISINFECTION BY ULTRAVIOLET LIGHT IRRADIATION

    EPA Science Inventory

    This article examines the performance and effectiveness of ultraviolet (UV) light irradiation for disinfection of combined sewer overflow (CSO). Due to the negative impact of conventional water disinfectants on aquatic life, new agents (e.g., UV light) are being investigated for ...

  17. ULTRAVIOLET LIGHT DISINFECTION OF COMBINED SEWER OVERFLOW (NEW ORLEANS)

    EPA Science Inventory

    The objective of this state-of-the-art review is to examine the performance and effectiveness of ultraviolet (UV) light disinfection for combined sewer overflow (CSO) applications. Topics presented include the use of UV light as a disinfecting agent, its practical applications, d...

  18. Report of Field Test Evaluation.

    ERIC Educational Resources Information Center

    Michigan State Univ., East Lansing. Regional Instructional Materials Center for Handicapped Children and Youth.

    Reported by the Great Lakes Region Special Education Instructional Materials Center are field test evaluation of 18 auditory instructional materials for use with handicapped children who learn best through the auditory modality. Among materials evaluated are a taped program on use of the abacus and a cassette audiotape on bird habits and sounds.…

  19. Real Time Monitoring of Dissolved Organic Carbon Concentration and Disinfection By-Product Formation Potential in a Surface Water Treatment Plant with Simulaneous UV-VIS Absorbance and Fluorescence Excitation-Emission Mapping

    NASA Astrophysics Data System (ADS)

    Gilmore, A. M.

    2015-12-01

    This study describes a method based on simultaneous absorbance and fluorescence excitation-emission mapping for rapidly and accurately monitoring dissolved organic carbon concentration and disinfection by-product formation potential for surface water sourced drinking water treatment. The method enables real-time monitoring of the Dissolved Organic Carbon (DOC), absorbance at 254 nm (UVA), the Specific UV Absorbance (SUVA) as well as the Simulated Distribution System Trihalomethane (THM) Formation Potential (SDS-THMFP) for the source and treated water among other component parameters. The method primarily involves Parallel Factor Analysis (PARAFAC) decomposition of the high and lower molecular weight humic and fulvic organic component concentrations. The DOC calibration method involves calculating a single slope factor (with the intercept fixed at 0 mg/l) by linear regression for the UVA divided by the ratio of the high and low molecular weight component concentrations. This method thus corrects for the changes in the molecular weight component composition as a function of the source water composition and coagulation treatment effects. The SDS-THMFP calibration involves a multiple linear regression of the DOC, organic component ratio, chlorine residual, pH and alkalinity. Both the DOC and SDS-THMFP correlations over a period of 18 months exhibited adjusted correlation coefficients with r2 > 0.969. The parameters can be reported as a function of compliance rules associated with required % removals of DOC (as a function of alkalinity) and predicted maximum contaminant levels (MCL) of THMs. The single instrument method, which is compatible with continuous flow monitoring or grab sampling, provides a rapid (2-3 minute) and precise indicator of drinking water disinfectant treatability without the need for separate UV photometric and DOC meter measurements or independent THM determinations.

  20. UV Waterworks Outreach Support. Final Report

    DOE R&D Accomplishments Database

    Miller, P.

    1998-05-01

    A recently invented device uses UV light (254 nm) to inexpensively disinfect community drinking water supplies. Its novel features are: low cost (about US $600), robust design, rapid disinfection (12 seconds), low electricity use (40W), low maintenance (every 6 months), high flow rate (15 l/min) and ability to work with unpressurized water sources. The device could service a community of 1,000 persons, at an annual total cost of 14 cents US per person. This device has been tested in a number of independent laboratories worldwide. The laboratory tests have confirmed that the unit is capable of disinfecting waters to drinking water standards for bacteria and viruses. An extended field trial of the device began in South Africa in February 1997, with lab testing at the municipal water utility. A unit installed at the first field site, an AIDS hospice near Durban, has been in continuous operation since August, 1997. Additional test sites are being identified. The author describes the results of the initial lab tests, reports the most recent findings from the ongoing field test-monitoring program, and discusses plans for future tests.

  1. UV waterworks outreach support. Final report

    SciTech Connect

    Miller, P.

    1998-12-31

    A recently invented device uses UV light (254 nm) to inexpensively disinfect community drinking water supplies. Its novel features are: low cost (about US $600), robust design, rapid disinfection (12 seconds), low electricity use (40W), low maintenance (every 6 months), high flow rate (15 l/min) and ability to work with unpressurized water sources. The device could service a community of 1,000 persons, at an annual total cost of 14 cents US per person. This device has been tested in a number of independent laboratories worldwide. The laboratory tests have confirmed that the unit is capable of disinfecting waters to drinking water standards for bacteria and viruses. An extended field trial of the device began in South Africa in February 1997, with lab testing at the municipal water utility. A unit installed at the first field site, an AIDS hospice near Durban, has been in continuous operation since August, 1997. Additional test sites are being identified. The author describes the results of the initial lab tests, reports the most recent findings from the ongoing field test-monitoring program, and discusses plans for future tests.

  2. Production Hydraulic Packer Field Test

    SciTech Connect

    Schneller, Tricia; Salas, Jose

    2000-06-30

    In October 1999, the Rocky Mountain Oilfield Testing Center and Halliburton Energy Services cooperated on a field test of Halliburton's new Production Hydraulic Packer technology on Well 46-TPX-10 at Naval Petroleum Reserve No. 3 near Casper, WY. Performance of the packer was evaluated in set and unset operations. The packer's ability to seal the annulus between the casing and tubing was hydraulically tested and the results were recorded.

  3. Descent Advisor Preliminary Field Test

    NASA Technical Reports Server (NTRS)

    Green, Steven M.; Vivona, Robert A.; Sanford, Beverly

    1995-01-01

    A field test of the Descent Advisor (DA) automation tool was conducted at the Denver Air Route Traffic Control Center in September 1994. DA is being developed to assist Center controllers in the efficient management and control of arrival traffic. DA generates advisories, based on trajectory predictions, to achieve accurate meter-fix arrival times in a fuel efficient manner while assisting the controller with the prediction and resolution of potential conflicts. The test objectives were: (1) to evaluate the accuracy of DA trajectory predictions for conventional and flight-management system equipped jet transports, (2) to identify significant sources of trajectory prediction error, and (3) to investigate procedural and training issues (both air and ground) associated with DA operations. Various commercial aircraft (97 flights total) and a Boeing 737-100 research aircraft participated in the test. Preliminary results from the primary test set of 24 commercial flights indicate a mean DA arrival time prediction error of 2.4 seconds late with a standard deviation of 13.1 seconds. This paper describes the field test and presents preliminary results for the commercial flights.

  4. Descent advisor preliminary field test

    NASA Technical Reports Server (NTRS)

    Green, Steven M.; Vivona, Robert A.; Sanford, Beverly

    1995-01-01

    A field test of the Descent Advisor (DA) automation tool was conducted at the Denver Air Route Traffic Control Center in September 1994. DA is being developed to assist Center controllers in the efficient management and control of arrival traffic. DA generates advisories, based on trajectory predictions, to achieve accurate meter-fix arrival times in a fuel efficient manner while assisting the controller with the prediction and resolution of potential conflicts. The test objectives were to evaluate the accuracy of DA trajectory predictions for conventional- and flight-management-system-equipped jet transports, to identify significant sources of trajectory prediction error, and to investigate procedural and training issues (both air and ground) associated with DA operations. Various commercial aircraft (97 flights total) and a Boeing 737-100 research aircraft participated in the test. Preliminary results from the primary test set of 24 commercial flights indicate a mean DA arrival time prediction error of 2.4 sec late with a standard deviation of 13.1 sec. This paper describes the field test and presents preliminary results for the commercial flights.

  5. Equivalency testing of ultraviolet disinfection for wastewater reclamation

    SciTech Connect

    Oppenheimer, J.A.; Jacangelo, J.G.; Laine, J.M.

    1996-11-01

    UV light disinfection was shown to continuously provide microbial inactivation equivalent to chlorine while reducing the formation of known carcinogenic disinfection by-products and the formation of chronic whole effluent toxicity. This was the first study to demonstrate UV`s performance relative to chlorination over an extended timeframe at a full-scale facility treating to meet the most stringent California reclamation standards.

  6. A stepped wedge, cluster-randomized trial of a household UV-disinfection and safe storage drinking water intervention in rural Baja California Sur, Mexico.

    PubMed

    Gruber, Joshua S; Reygadas, Fermin; Arnold, Benjamin F; Ray, Isha; Nelson, Kara; Colford, John M

    2013-08-01

    In collaboration with a local non-profit organization, this study evaluated the expansion of a program that promoted and installed Mesita Azul, an ultraviolet-disinfection system designed to treat household drinking water in rural Mexico. We conducted a 15-month, cluster-randomized stepped wedge trial by randomizing the order in which 24 communities (444 households) received the intervention. We measured primary outcomes (water contamination and diarrhea) during seven household visits. The intervention increased the percentage of households with access to treated and safely stored drinking water (23-62%), and reduced the percentage of households with Escherichia coli contaminated drinking water (risk difference (RD): -19% [95% CI: -27%, -14%]). No significant reduction in diarrhea was observed (RD: -0.1% [95% CI: -1.1%, 0.9%]). We conclude that household water quality improvements measured in this study justify future promotion of the Mesita Azul, and that future studies to measure its health impact would be valuable if conducted in populations with higher diarrhea prevalence. PMID:23732255

  7. A Stepped Wedge, Cluster-Randomized Trial of a Household UV-Disinfection and Safe Storage Drinking Water Intervention in Rural Baja California Sur, Mexico

    PubMed Central

    Gruber, Joshua S.; Reygadas, Fermin; Arnold, Benjamin F.; Ray, Isha; Nelson, Kara; Colford, John M.

    2013-01-01

    In collaboration with a local non-profit organization, this study evaluated the expansion of a program that promoted and installed Mesita Azul, an ultraviolet-disinfection system designed to treat household drinking water in rural Mexico. We conducted a 15-month, cluster-randomized stepped wedge trial by randomizing the order in which 24 communities (444 households) received the intervention. We measured primary outcomes (water contamination and diarrhea) during seven household visits. The intervention increased the percentage of households with access to treated and safely stored drinking water (23–62%), and reduced the percentage of households with Escherichia coli contaminated drinking water (risk difference (RD): −19% [95% CI: −27%, −14%]). No significant reduction in diarrhea was observed (RD: −0.1% [95% CI: −1.1%, 0.9%]). We conclude that household water quality improvements measured in this study justify future promotion of the Mesita Azul, and that future studies to measure its health impact would be valuable if conducted in populations with higher diarrhea prevalence. PMID:23732255

  8. A stepped wedge, cluster-randomized trial of a household UV-disinfection and safe storage drinking water intervention in rural Baja California Sur, Mexico.

    PubMed

    Gruber, Joshua S; Reygadas, Fermin; Arnold, Benjamin F; Ray, Isha; Nelson, Kara; Colford, John M

    2013-08-01

    In collaboration with a local non-profit organization, this study evaluated the expansion of a program that promoted and installed Mesita Azul, an ultraviolet-disinfection system designed to treat household drinking water in rural Mexico. We conducted a 15-month, cluster-randomized stepped wedge trial by randomizing the order in which 24 communities (444 households) received the intervention. We measured primary outcomes (water contamination and diarrhea) during seven household visits. The intervention increased the percentage of households with access to treated and safely stored drinking water (23-62%), and reduced the percentage of households with Escherichia coli contaminated drinking water (risk difference (RD): -19% [95% CI: -27%, -14%]). No significant reduction in diarrhea was observed (RD: -0.1% [95% CI: -1.1%, 0.9%]). We conclude that household water quality improvements measured in this study justify future promotion of the Mesita Azul, and that future studies to measure its health impact would be valuable if conducted in populations with higher diarrhea prevalence.

  9. Comparison of the action spectra and relative DNA absorbance spectra of microorganisms: information important for the determination of germicidal fluence (UV dose) in an ultraviolet disinfection of water.

    PubMed

    Chen, Ren Zhuo; Craik, Stephen A; Bolton, James R

    2009-12-01

    The action spectra of Bacillus subtilis spores (ATCC6633) and Salmonella typhimurium LT2 were characterized using physical radiometry for irradiance measurements and a multiple target model to interpret the inactivation kinetics. The observed action spectrum of B. subtilis spores deviated significantly from the relative absorbance spectrum of the DNA purified from the spores, but matched quite well with the relative absorbance spectrum of decoated spores. The action spectrum of B. subtilis spores determined in this study was statistically different from those reported in previous studies. On the other hand, the action spectrum of S. typhimurium bacteria matched quite well with the relative absorbance spectrum of DNA extracted from vegetative cells, except in the region below 240nm. It is concluded that the common use of the relative DNA absorbance spectrum as a surrogate for the germicidal action spectrum can result in systematic errors when evaluating the performance of a polychromatic UV light reactors using bioassays. For example, if the weighted germicidal fluence (UV dose) calculated using the relative DNA absorbance spectrum as the germicidal weighting factor is found to be 40mJcm(-2) for a medium pressure lamp UV reactor, that calculated using the relative action spectrum of B. subtilis spores, as determined in this study, would be 66mJcm(-2). PMID:19762061

  10. Comparison of the action spectra and relative DNA absorbance spectra of microorganisms: information important for the determination of germicidal fluence (UV dose) in an ultraviolet disinfection of water.

    PubMed

    Chen, Ren Zhuo; Craik, Stephen A; Bolton, James R

    2009-12-01

    The action spectra of Bacillus subtilis spores (ATCC6633) and Salmonella typhimurium LT2 were characterized using physical radiometry for irradiance measurements and a multiple target model to interpret the inactivation kinetics. The observed action spectrum of B. subtilis spores deviated significantly from the relative absorbance spectrum of the DNA purified from the spores, but matched quite well with the relative absorbance spectrum of decoated spores. The action spectrum of B. subtilis spores determined in this study was statistically different from those reported in previous studies. On the other hand, the action spectrum of S. typhimurium bacteria matched quite well with the relative absorbance spectrum of DNA extracted from vegetative cells, except in the region below 240nm. It is concluded that the common use of the relative DNA absorbance spectrum as a surrogate for the germicidal action spectrum can result in systematic errors when evaluating the performance of a polychromatic UV light reactors using bioassays. For example, if the weighted germicidal fluence (UV dose) calculated using the relative DNA absorbance spectrum as the germicidal weighting factor is found to be 40mJcm(-2) for a medium pressure lamp UV reactor, that calculated using the relative action spectrum of B. subtilis spores, as determined in this study, would be 66mJcm(-2).

  11. HIGH-RATE DISINFECTION TECHNIQUES FOR COMBIND SEWER OVERFLOW

    EPA Science Inventory

    This paper presents high-rate disinfection technologies for combined sewer overflow (CSO). The high-rate disinfection technologies of interest are: chlorination/dechlorination, ultraviolet light irradiation (UV), chlorine dioxide (ClO2 ), ozone (O3), peracetic acid (CH3COOOH )...

  12. New formaldehyde base disinfectants.

    NASA Technical Reports Server (NTRS)

    Trujillo, R.; Lindell, K. F.

    1973-01-01

    Preparations of formaldehyde in various organic liquids - ethylene glycol, glycerol, and propylene glycol - serve as effective disinfectants towards microbial vegetative cells and spores. This disinfection is a temperature-dependent process and is manifest when these formaldehyde base disinfectants are dissolved in water. The irritating vapors associated with formaldehyde disinfection are not present in either of these new formaldehyde base disinfectants or in aqueous solutions of them.

  13. Disinfection of contaminated water by using solar irradiation.

    PubMed

    Caslake, Laurie F; Connolly, Daniel J; Menon, Vilas; Duncanson, Catriona M; Rojas, Ricardo; Tavakoli, Javad

    2004-02-01

    Contaminated water causes an estimated 6 to 60 billion cases of gastrointestinal illness annually. The majority of these cases occur in rural areas of developing nations where the water supply remains polluted and adequate sanitation is unavailable. A portable, low-cost, and low-maintenance solar unit to disinfect unpotable water has been designed and tested. The solar disinfection unit was tested with both river water and partially processed water from two wastewater treatment plants. In less than 30 min in midday sunlight, the unit eradicated more than 4 log10 U (99.99%) of bacteria contained in highly contaminated water samples. The solar disinfection unit has been field tested by Centro Panamericano de Ingenieria Sanitaria y Ciencias del Ambiente in Lima, Peru. At moderate light intensity, the solar disinfection unit was capable of reducing the bacterial load in a controlled contaminated water sample by 4 log10 U and disinfected approximately 1 liter of water in 30 min.

  14. Reaction of silver nanoparticles in the disinfection process.

    PubMed

    Yuan, Zhihua; Chen, Yunbin; Li, Tingting; Yu, Chang-Ping

    2013-10-01

    This study investigated the dissolution, aggregation, and reaction kinetics of silver nanoparticles (AgNPs) with the three types of water disinfectants (ultraviolet, sodium hypochlorite, and ozone) under the different conditions of pH, ionic strength, or humic acid (HA). The physicochemical changes of AgNPs were measured by using UV-Vis spectroscopy, transmission electron microscopy, and inductively coupled plasma optical emission spectrometer. The results showed that when AgNPs contacted the disinfectants, oxidative dissolution was the primary reaction. In addition, the reaction kinetics studies revealed that the reaction rate of AgNPs with disinfectants was significantly influenced by different disinfectants along with different pH and the presence of sodium nitrate and HA. Our research demonstrated the potential effect of disinfectants on AgNPs, which will improve our understanding of the fate of AgNPs in the disinfection processes in the water and wastewater treatment plant. PMID:23830116

  15. Reaction of silver nanoparticles in the disinfection process.

    PubMed

    Yuan, Zhihua; Chen, Yunbin; Li, Tingting; Yu, Chang-Ping

    2013-10-01

    This study investigated the dissolution, aggregation, and reaction kinetics of silver nanoparticles (AgNPs) with the three types of water disinfectants (ultraviolet, sodium hypochlorite, and ozone) under the different conditions of pH, ionic strength, or humic acid (HA). The physicochemical changes of AgNPs were measured by using UV-Vis spectroscopy, transmission electron microscopy, and inductively coupled plasma optical emission spectrometer. The results showed that when AgNPs contacted the disinfectants, oxidative dissolution was the primary reaction. In addition, the reaction kinetics studies revealed that the reaction rate of AgNPs with disinfectants was significantly influenced by different disinfectants along with different pH and the presence of sodium nitrate and HA. Our research demonstrated the potential effect of disinfectants on AgNPs, which will improve our understanding of the fate of AgNPs in the disinfection processes in the water and wastewater treatment plant.

  16. Kinetics of UV inactivation of wastewater bioflocs.

    PubMed

    Azimi, Y; Allen, D G; Farnood, R R

    2012-08-01

    Ultraviolet disinfection is a physical method of disinfecting secondary treated wastewaters. Bioflocs formed during secondary treatment harbor and protect microbes from exposure to ultraviolet (UV) light, and significantly decrease the efficiency of disinfection at high UV doses causing the tailing phenomena. However, the exact mechanism of tailing and the role of biofloc properties and treatment conditions are not widely understood. It is hypothesized that sludge bioflocs are composed of an easily disinfectable loose outer shell, and a physically stronger compact core inside that accounts for the tailing phenomena. Hydrodynamic shear stress was applied to the bioflocs to peel off the looser outer shell to isolate the cores. Biofloc and core samples were fractionated into narrow size distributions by sieving and their UV disinfection kinetics were determined and compared. The results showed that for bioflocs, the tailing level elevates as the biofloc size increases, showing greater resistance to disinfection. However, for the cores larger than 45μm, it was found that the UV inactivation curves overlap, and show very close to identical inactivation kinetics. Comparing bioflocs and cores of similar size fraction, it was found that in all cases cores were harder to disinfect with UV light, and showed a higher tailing level. This study suggests that physical structure of bioflocs plays a significant role in the UV inactivation kinetics. PMID:22608608

  17. Kinetics of UV inactivation of wastewater bioflocs.

    PubMed

    Azimi, Y; Allen, D G; Farnood, R R

    2012-08-01

    Ultraviolet disinfection is a physical method of disinfecting secondary treated wastewaters. Bioflocs formed during secondary treatment harbor and protect microbes from exposure to ultraviolet (UV) light, and significantly decrease the efficiency of disinfection at high UV doses causing the tailing phenomena. However, the exact mechanism of tailing and the role of biofloc properties and treatment conditions are not widely understood. It is hypothesized that sludge bioflocs are composed of an easily disinfectable loose outer shell, and a physically stronger compact core inside that accounts for the tailing phenomena. Hydrodynamic shear stress was applied to the bioflocs to peel off the looser outer shell to isolate the cores. Biofloc and core samples were fractionated into narrow size distributions by sieving and their UV disinfection kinetics were determined and compared. The results showed that for bioflocs, the tailing level elevates as the biofloc size increases, showing greater resistance to disinfection. However, for the cores larger than 45μm, it was found that the UV inactivation curves overlap, and show very close to identical inactivation kinetics. Comparing bioflocs and cores of similar size fraction, it was found that in all cases cores were harder to disinfect with UV light, and showed a higher tailing level. This study suggests that physical structure of bioflocs plays a significant role in the UV inactivation kinetics.

  18. Minicourse 18: Main Field Test Report.

    ERIC Educational Resources Information Center

    Skailand, Dawn

    This report describes the main field test of Minicourse 18: Teaching Reading as Decoding. The purposes of the main field test were: (1) to evaluate the effects of the course on the participating teachers, (2) to evaluate four reteach treatments on teacher skill acquisition, (3) to compare scores for central city and suburban teachers, and (4) to…

  19. Field Testing: A Model and Its Applications.

    ERIC Educational Resources Information Center

    Goldstein, Marjorie T.

    Described is a Social Learning Curriculum (SLC) field test model that focuses on aspects of personnel utilization, communication systems, and the quality of human communication and that highlights the role of the supervisor in the education of the mentally retarded. The four field test model phases discussed are 1) the planning phase (including…

  20. Peracetic acid for secondary effluent disinfection: a comprehensive performance assessment.

    PubMed

    Antonelli, M; Turolla, A; Mezzanotte, V; Nurizzo, C

    2013-01-01

    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 of the research were: (1) determining PAA decay and disinfection kinetics as a function of operating parameters, (2) evaluating PAA suitability as a disinfectant, (3) assessing long-term disinfection efficiency, (4) investigating disinfected effluent biological toxicity on some aquatic indicator organisms (Vibrio fischeri, Daphnia magna and Selenastrum capricornutum), (5) comparing PAA with conventional disinfectants (sodium hypochlorite, UV irradiation). PAA disinfection was capable of complying with Italian regulations on reuse (10 CFU/100 mL for E. coli) and was competitive with benchmarks. No regrowth phenomena were observed, as long as needed for agricultural reuse (29 h after disinfection), even at negligible concentrations of residual disinfectant. The toxic effect of PAA on the aquatic environment was due to the residual disinfectant in the water, rather than to chemical modification of the effluent. PMID:24355852

  1. Lighting the way to improved disinfection

    SciTech Connect

    Valenti, M.

    1997-07-01

    Ultraviolet light has a proven track record of killing bacteria and viruses found in municipal wastewater. In addition, environmental concerns over the use of chemical disinfectants, coupled with improvements in ultraviolet-lighting technology, have led to the development of UV systems that treat spent metalworking fluids in the industrialized world; disinfect drinking water in developing countries; and clean aquaculture water, ballast water, and hospital air everywhere. A large-scale pilot plant capable of treating less than 1 million gallons per day was built on-site by Los Angeles-based Montgomery Watson and CCCSD in 1992. It demonstrated that UV was just as effective as chlorination in killing bacteria and slightly more effective in destroying viruses found in the Martinez plant`s wastewater. It also showed the lamps would need to be cleaned of fouling every two to four weeks. The paper discusses this plant and the use of UV light in the above-mentioned water treatment processes.

  2. Impact of suspended particles and enhancement techniques on ultraviolet disinfection of a secondary effluent

    NASA Astrophysics Data System (ADS)

    Wang, Jianling; Wang, Lin; Wang, Baozhen; Zhang, Jinsong; Zou, Qixian

    2006-10-01

    The concentration of suspended solids in the secondary effluent often varies widely, leading to frequent adjustment of the UV dosage to meet the disinfection criterion. In addition, a desired disinfection rate is difficult to achieve sometimes. The authors studied the particle size distribution, contribution of particle-associated Fecal Coliform (F.C.), and their influences on UV disinfection. A combined disinfection process (chlorination with a subsequent UV disinfection) was tested to improve the disinfection effect. The results indicated that the content of suspended solids, especially that of large particles, has a strong impact on UV disinfection efficiency; Dτ;10µm particles associated F.C. are difficult to be disinfected and are the main part of the tailings of F.C. inactivation curves. Pre-chlorination could decrease the number of particles in the secondary effluent and transform the large particles into small ones, reducing the influence of particles on UV disinfection and enhancing the resistance ability of the combined process to particle loading.

  3. Indicators for photoreactivation and dark repair studies following ultraviolet disinfection.

    PubMed

    Quek, Puay Hoon; Hu, Jiangyong

    2008-06-01

    Repair of DNA in bacteria following ultraviolet (UV) disinfection can cause reactivation of inactivated bacteria and negatively impact the efficiency of the UV disinfection process. In this study, various strains of E. coli (wild-type, UV-resistant and antibiotic-resistant strains) were investigated for their ability to perform dark repair and photoreactivation, and compared based on final repair levels after 4 h of incubation, as well as repair rates. Analysis of the results revealed that the repair abilities of different E. coli strains can differ quite significantly. In photoreactivation, the log repair ranged from 10 to 85%, with slightly lower log repair percentages when medium-pressure (MP) UV disinfection was employed. In dark repair, log repair ranged from 13 to 28% following low-pressure (LP) UV disinfection. E. coli strains ATCC 15597 and ATCC 11229 were found to repair the fastest and to the highest levels for photoreactivation and dark repair, respectively. These strains were also confirmed to repair to higher levels when compared to a pathogenic E. coli O157:H7 strain. Hence, these strains could possibly serve as conservative indicators for future repair studies following UV disinfection. In addition, dimer repair by photoreactivation and dark repair was also confirmed on a molecular level using the endonuclease sensitive site (ESS) assay.

  4. Enhanced UV inactivation of adenoviruses under polychromatic UV lamps.

    PubMed

    Linden, Karl G; Thurston, Jeanette; Schaefer, Raymond; Malley, James P

    2007-12-01

    Adenovirus is recognized as the most UV-resistant waterborne pathogen of concern to public health microbiologists. The U.S. EPA has stipulated that a UV fluence (dose) of 186 mJ cm(-2) is required for 4-log inactivation credit in water treatment. However, all adenovirus inactivation data to date published in the peer-reviewed literature have been based on UV disinfection experiments using UV irradiation at 253.7 nm produced from a conventional low-pressure UV source. The work reported here presents inactivation data for adenovirus based on polychromatic UV sources and details the significant enhancement in inactivation achieved using these polychromatic sources. When full-spectrum, medium-pressure UV lamps were used, 4-log inactivation of adenovirus type 40 is achieved at a UV fluence of less than 60 mJ cm(-2) and a surface discharge pulsed UV source required a UV fluence of less than 40 mJ cm(-2). The action spectrum for adenovirus type 2 was also developed and partially explains the improved inactivation based on enhancements at wavelengths below 230 nm. Implications for water treatment, public health, and the future of UV regulations for virus disinfection are discussed. PMID:17933932

  5. Witnessing orifice meter calibration and field testing

    SciTech Connect

    Woods, D.

    1995-12-01

    It would seem with the advent of electronic measurement and electronic custody transfer of natural gas and other petroleum products that witnessing orifice meter calibration and field testing would become an obsolete practice in the petroleum industry. This however, is not the case. Due to low volume measurement, remote locations, dollar cost of electronic measurement, and arrangements between companies regarding electronic custody, transfer, witnessing orifice meter calibration and field testing will continue to be an integral part of the petroleum industry`s future. Even as technology moves forward and electronic measurement becomes common within the petroleum industry, electronic hardware used in measurement will, like the orifice recorder, only be a secondary measuring device. The meter tube and orifice plate will continue to be the primary measuring device. Due to these circumstances witnessing orifice meter calibration and field testing will also continue to be important even though some emphasis will be shifted to witnessing field testing of electronic equipment. The information in this paper is not meant to be an absolute, but, to be used as a guide in witnessing and field testing orifice meters. There are many variables in testing that. due to the length of this paper, will not be discussed.

  6. SRS environmental technology development field test platform

    SciTech Connect

    Riha, B.D.; Rossabi, J.; Eddy-Dilek, C.A.

    1995-09-01

    A critical and difficult step in the development and implementation of new technologies for environmental monitoring and characterization is successfully transferring these technologies to industry and government users for routine assessment and compliance activities. The Environmental Sciences Section of the DOE Savannah River Technology Center provides a forum for developers, potential users, and regulatory organizations to evaluate new technologies in comparison with baseline technologies in a well characterized field test bed. The principal objective of this project is to conduct comprehensive, objective field tests of monitoring and characterization technologies that are not currently used in EPA standard methods and evaluate their performance during actual operating conditions against baseline methods. This paper provides an overview of the field test site and a description of some of the technologies demonstrated at the site including their field applications.

  7. Biodiesel from wastewater: lipid production in high rate algal pond receiving disinfected effluent.

    PubMed

    Assemany, Paula Peixoto; Calijuri, Maria Lucia; do Couto, Eduardo de Aguiar; Santiago, Aníbal Fonseca; Dos Reis, Alberto José Delgado

    2015-01-01

    The production of different species of microalgae in consortium with other micro-organisms from wastewaters may represent an alternative process, to reduce the costs, for obtaining biofuels. The aim of this study was to evaluate the influence of pre-ultraviolet disinfection (UV) in the production of lipids from biomass produced in high rate ponds. Two high rate algal ponds were evaluated: a pond that received domestic sewage without disinfection and the other receiving domestic sewage previously disinfected by UV radiation (uvHRAP). The UV disinfection did not lead to significant differences in fatty acid profile and total lipid productivities, although it increased algal biomass concentration and productivity as well as lipid content. Moreover, the overall biomass concentrations and productivities decreased with the UV disinfection, mostly as a consequence of a loss in bacterial load. We thus conclude that uvHRAP disinfection may represent a potential strategy to promote the cleaner and safer growth of algal biomass when cultivated in consortium with other micro-organisms. Mainly regarding the use of wastewater as culture medium, together with a cheaper production of lipids for biodiesel, pre-disinfection may represent an advance since extraction costs could be significantly trimmed due to the increase in lipid content.

  8. Ultraviolet disinfection of fecal coliform in municipal wastewater: effects of particle size.

    PubMed

    Madge, Bethany A; Jensen, James N

    2006-03-01

    Suspended solids interfere with the efficiency of disinfection using UV radiation by decreasing the rate of disinfection and inducing tailing. However, conventional measures of solids (total suspended solids, turbidity, and UV transmittance) do not adequately predict the presence or degree of these effects. Bacteria and viruses can become associated with particles in wastewater. A fractionation technique was developed to separate particle-associated bacteria into three fractions, based on particle size. The results show that the degree to which particles interfere with UV disinfection efficiency is dependent on particle size. The small size fraction (< 5 microm) consistently produced a statistically significant faster disinfection rate than the large fraction (> 20 microm), with the unfiltered sample and the medium fraction (particles > 5 microm, but < 20 microm) between the two extremes. Tailing also was observed only in the large fraction. Correlations between the disinfection rate constant and the percentage of large fraction bacteria of a sample were good.

  9. Ice slurry cooling development and field testing

    SciTech Connect

    Kasza, K.E.; Hietala, J.; Wendland, R.D.; Collins, F.

    1992-07-01

    A new advanced cooling technology collaborative program is underway involving Argonne National Laboratory (ANL), Northern States Power (NSP) and the Electric Power Research Institute (EPRI). The program will conduct field tests of an ice slurry distributed load network cooling concept at a Northern States Power utility service center to further develop and prove the technology and to facilitate technology transfer to the private sector. The program will further develop at Argonne National Laboratory through laboratory research key components of hardware needed in the field testing and develop an engineering data base needed to support the implementation of the technology. This program will sharply focus and culminate research and development funded by both the US Department of Energy and the Electric Power Research Institute on advanced cooling and load management technology over the last several years.

  10. Ice slurry cooling development and field testing

    SciTech Connect

    Kasza, K.E. ); Hietala, J. ); Wendland, R.D. ); Collins, F. )

    1992-01-01

    A new advanced cooling technology collaborative program is underway involving Argonne National Laboratory (ANL), Northern States Power (NSP) and the Electric Power Research Institute (EPRI). The program will conduct field tests of an ice slurry distributed load network cooling concept at a Northern States Power utility service center to further develop and prove the technology and to facilitate technology transfer to the private sector. The program will further develop at Argonne National Laboratory through laboratory research key components of hardware needed in the field testing and develop an engineering data base needed to support the implementation of the technology. This program will sharply focus and culminate research and development funded by both the US Department of Energy and the Electric Power Research Institute on advanced cooling and load management technology over the last several years.

  11. Disinfection. [Wastewater treatment

    SciTech Connect

    Haas, C.N.; McCreary, J.J.

    1982-06-01

    Methods of disinfection of wastewater including chlorination, ultraviolet radiation, ozone, and quaternary compounds are reviewed. Various analytical methods to detect residues of the disinfectants are described. The production of inorganic and nonvolatile organic compounds in conventional water treatment processes is reviewed. (KRM)

  12. Cold chain: solar refrigerator field tested.

    PubMed

    1983-04-01

    The Health Ministries of Colombia and Peru, in collaboration with the Expanded Program on Immunization (EPI)/Pan American Health Organization (PAHO) and the Centers for Disease Control (CDC), have begun field testing a solar-powered vaccine refrigerator. The aim of the fields trials is to determine whether solar refrigerators can maintain the temperatures required for vaccine storage (+4-8 degrees Celsius) and produce ice at a rate of 2 kg/24 hours under different environmental conditions. these refrigerators would be particularly useful in areas that lack a consistent supply of good quality fuel or where the electrical supply is intermittent or nonexistent. Full appraisal of this technology will require 2 years of field testing; Colombia and Peru expect to complete testing in 1985. To date, 5 models have passed CDC-developed specifications, all of which are manufactured in the US. PAHO/WHO recommends that health ministries should consider the following guidelines in considering the purchase of a particular system: the initial purchase should be for a limited quantity (about 5) of refrigerators to permit field testing; solar panels should meet specific criteria; consideration should be given only to those models that have passed qualification tests; each unit should be fully equipped with monitoring devices and spare parts; and a trained refrigerator technician should be available to repair the equipment.

  13. Investigating synergism during sequential inactivation of Bacillus subtilis spores with several disinfectants.

    PubMed

    Cho, Min; Kim, Jae-Hong; Yoon, Jeyong

    2006-08-01

    The sequential application of ozone, chlorine dioxide, or UV followed by free chlorine was performed to investigate the synergistic inactivation of Bacillus subtilis spores. The greatest synergism was observed when chlorine dioxide was used as a primary disinfectant followed by secondary disinfection with free chlorine. A lesser synergistic effect was observed when ozone was used as the primary disinfectant, but no synergism was observed when UV was used as the primary disinfectant. When free chlorine was used as the primary disinfectant (i.e., sequential application in the reverse order), the synergistic effect was shown only when chlorine dioxide was applied as the secondary disinfectant. The synergistic effect observed could be related to damage to the spore coat during primary disinfection, suggested by the loss of proteins from spores during disinfectant treatment. The greatest synergism observed by the chlorine dioxide/free chlorine pair suggested that common reaction sites might exist for these disinfectants. The concept of percent synergistic effect was introduced to quantitatively compare the extent of synergistic effects in the sequential disinfection processes.

  14. High-Rate Disinfection Techniques for Combined Sewer Overflow (Proceedings Paper)

    EPA Science Inventory

    This paper presents high-rate disinfection technologies for combined sewer overflow (CSO). The high-rate disinfection technologies of interest are: chlorination/dechlorination, ultraviolet light irradiation (UV), chlorine dioxide (ClO2 ), ozone (O3), peracetic acid (CH3COOOH ), a...

  15. Differential toxicity of drinking water disinfected with combinations of ultraviolet radiation and chlorine.

    PubMed

    Plewa, Michael J; Wagner, Elizabeth D; Metz, Deborah H; Kashinkunti, Ramesh; Jamriska, Katherine J; Meyer, Maria

    2012-07-17

    Alternative technologies to disinfect drinking water such as ultraviolet (UV) disinfection are becoming more widespread. The benefits of UV disinfection include reduced risk of microbial pathogens such as Cryptosporidium and reduced production of regulated drinking water disinfection byproducts (DBPs). The objective of this research was to determine if mammalian cell cytotoxicity and genotoxicity varied in response to different chlorination protocols with and without polychromatic medium pressure UV (MPUV) and monochromatic low pressure UV (LPUV) disinfection technologies. The specific aims were to analyze the mammalian cell cytotoxicity and genotoxicity of concentrated organic fractions from source water before and after chlorination and to determine the cytotoxicity and genotoxicity of the concentrated organic fractions from water samples treated with UV alone or UV before or after chlorination. Exposure of granular activated carbon-filtered Ohio River water to UV alone resulted in the lowest levels of mammalian cell cytotoxicity and genotoxicity. With combinations of UV and chlorine, the lowest levels of cytotoxicity and genotoxicity were observed with MPUV radiation. The best combined UV plus chlorine methodology that generated the lowest cytotoxicity and genotoxicity employed chlorination first followed by MPUV radiation. These data may prove important in the development of multibarrier methods of pathogen inactivation of drinking water, while limiting unintended toxic consequences.

  16. UV/H(2)O(2) treatment of drinking water increases post-chlorination DBP formation.

    PubMed

    Dotson, Aaron D; Keen, Volha Olya S; Metz, Debbie; Linden, Karl G

    2010-06-01

    Ultraviolet (UV) irradiation has become popular as a primary disinfectant because it is very effective against Cryptosporidium and does not directly form regulated disinfection by-products. Higher UV doses and UV advanced oxidation (UV/H2O2) processes are under consideration for the treatment of trace organic pollutants (e.g. pharmaceuticals, personal care products). Despite the disinfection effectiveness of UV light, a secondary disinfectant capable of maintaining a distribution system residual is required to meet current U.S. regulation. This study investigated changes in disinfection by-product (DBP) formation attributed to UV or UV/H2O2 followed by application of free chlorine to quench hydrogen peroxide and provide residual disinfectant. At a UV dose of 1000 mJ/cm(2), trihalomethane (THM) yield increased by up to 4 microg/mg-C and 13 microg/mg-C when treated with low and medium pressure UV, respectively. With the addition of hydrogen peroxide, THM yield increased by up to 25 microg/mg-C (5mg-H2O2/L) and 37 microg/mg-C (10 mg-H2O2/L). Although no changes in DBPs are expected during UV disinfection, application of UV advanced oxidation followed by chlorine addition was assessed with regard to impacts on DBP formation.

  17. MONITORING FOR AEROMONAS SPECIES AFTER TREATMENT WITH COMMON DRINKING WATER DISINFECTANTS

    EPA Science Inventory

    The sensitivity of Aeromonas spp. To free chlorine, chloramine and ultraviolet (UV) disinfection was determined. Aeromonas hydrophila is a contaminant listed on the USEPA's 1998 Contaminant Candidate List (CCL). Experiments using free chlorine indicated that the Aeromonas spp. ...

  18. Mechanisms of Escherichia coli inactivation by several disinfectants.

    PubMed

    Cho, Min; Kim, Jaeeun; Kim, Jee Yeon; Yoon, Jeyong; Kim, Jae-Hong

    2010-06-01

    The objective of this study was to elucidate dominant mechanisms of inactivation, i.e. surface attack versus intracellular attack, during application of common water disinfectants such as ozone, chlorine dioxide, free chlorine and UV irradiation. Escherichia coli was used as a representative microorganism. During cell inactivation, protein release, lipid peroxidation, cell permeability change, damage in intracellular enzyme and morphological change were comparatively examined. For the same level of cell inactivation by chemical disinfectants, cell surface damage was more pronounced with strong oxidant such as ozone while damage in inner cell components was more apparent with weaker oxidant such as free chlorine. Chlorine dioxide showed the inactivation mechanism between these two disinfectants. The results suggest that the mechanism of cell inactivation is primarily related to the reactivity of chemical disinfectant. In contrast to chemical disinfectants, cell inactivation by UV occurred without any changes measurable with the methods employed. Understanding the differences in inactivation mechanisms presented herein is critical to identify rate-limiting steps involved in the inactivation process as well as to develop more effective disinfection strategies.

  19. Efficacy of Inactivation of Human Enteroviruses by Multiple-Wavelength UV LEDs

    EPA Science Inventory

    Ultraviolet (UV) light has been successfully used for treating a broad suite of pathogens without the concomitant formation of carcinogenic disinfection by-products (DBPs). However, conventional mercury UV lamps have some practical limitations in water treatment applications, suc...

  20. Efficacy of Inactivation of Human Enteroviruses by Multiple-Wavelength UV LEDs - abstract

    EPA Science Inventory

    Background: Ultraviolet (UV) light has been successfully used for treating a broad suite of pathogens without the concomitant formation of carcinogenic disinfection by-products (DBPs). However, conventional mercury UV lamps have some practical limitations in water treatment appli...

  1. Goldstone field test activities: Target search

    NASA Technical Reports Server (NTRS)

    Tarter, J.

    1986-01-01

    In March of this year prototype SETI equipment was installed at DSS13, the 26 meter research and development antenna at NASA's Goldstone complex of satellite tracking dishes. The SETI equipment will remain at this site at least through the end of the summer so that the hardware and software developed for signal detection and recognition can be fully tested in a dynamic observatory environment. The field tests are expected to help understand which strategies for observing and which signal recognition algorithms perform best in the presence of strong man-made interfering signals (RFI) and natural astronomical sources.

  2. Issues related to field testing in tuff

    SciTech Connect

    Zimmerman, R.M.

    1982-12-31

    This paper has brought out the unique properties of tuffs and related them to needs associated with their use as a host rock for a high level nuclear waste repository. Major issues of temperature, pore water, joints, and depositional patterns have been identified and related responses and impacts outlined in Table 1. Planned experiments have been outlined and their relationships to the rock mechanics issues summarized in Table 2. The conclusions from this paper are: (1) tuff is a complex rock and basic phenomenological understanding is incomplete; and (2) available field test facilities will be used for a series of experiments designed to improve phenomenological understanding and support repository design efforts.

  3. Humidifier disinfectants, unfinished stories.

    PubMed

    Choi, Yeyong; Paek, Domyung

    2016-01-01

    Once released into the air, humidifier disinfectants became tiny nano-size particles, and resulted in chemical bronchoalveolitis. Families had lost their most beloved members, and even some of them became broken. Based on an estimate of two million potential victims who had experienced adverse effects from the use of humidifier disinfectants, we can say that what we have observed was only the tip of the iceberg. Problems of entire airways, as well as other systemic effects, should be examined, as we know these nano-size particles can irritate cell membranes and migrate into systemic circulation. The story of humidifier disinfectant is not finished yet. PMID:26987713

  4. Effects of wastewater disinfection on waterborne bacteria and viruses

    USGS Publications Warehouse

    Blatchley, E. R.; Gong, W.-L.; Alleman, J.E.; Rose, J.B.; Huffman, D.E.; Otaki, M.; Lisle, J.T.

    2007-01-01

    Wastewater disinfection is practiced with the goal of reducing risks of human exposure to pathogenic microorganisms. In most circumstances, the efficacy of a wastewater disinfection process is regulated and monitored based on measurements of the responses of indicator bacteria. However, inactivation of indicator bacteria does not guarantee an acceptable degree of inactivation among other waterborne microorganisms (e.g., microbial pathogens). Undisinfected effluent samples from several municipal wastewater treatment facilities were collected for analysis. Facilities were selected to provide a broad spectrum of effluent quality, particularly as related to nitrogenous compounds. Samples were subjected to bench-scale chlorination and dechlorination and UV irradiation under conditions that allowed compliance with relevant discharge regulations and such that disinfectant exposures could be accurately quantified. Disinfected samples were subjected to a battery of assays to assess the immediate and long-term effects of wastewater disinfection on waterborne bacteria and viruses. In general, (viable) bacterial populations showed an immediate decline as a result of disinfectant exposure; however, incubation of disinfected samples under conditions that were designed to mimic the conditions in a receiving stream resulted in substantial recovery of the total bacterial community. The bacterial groups that are commonly used as indicators do not provide an accurate representation of the response of the bacterial community to disinfectant exposure and subsequent recovery in the environment. UV irradiation and chlorination/dechlorination both accomplished measurable inactivation of indigenous phage; however, the extent of inactivation was fairly modest under the conditions of disinfection used in this study. UV irradiation was consistently more effective as a virucide than chlorination/dechlorination under the conditions of application, based on measurements of virus (phage

  5. Comparative Field Tests of Pressurised Rover Prototypes

    NASA Astrophysics Data System (ADS)

    Mann, G. A.; Wood, N. B.; Clarke, J. D.; Piechochinski, S.; Bamsey, M.; Laing, J. H.

    The conceptual designs, interior layouts and operational performances of three pressurised rover prototypes - Aonia, ARES and Everest - were field tested during a recent simulation at the Mars Desert Research Station in Utah. A human factors experiment, in which the same crew of three executed the same simulated science mission in each of the three vehicles, yielded comparative data on the capacity of each vehicle to safely and comfortably carry explorers away from the main base, enter and exit the vehicle in spacesuits, perform science tasks in the field, and manage geological and biological samples. As well as offering recommendations for design improvements for specific vehicles, the results suggest that a conventional Sports Utility Vehicle (SUV) would not be suitable for analog field work; that a pressurised docking tunnel to the main habitat is essential; that better provisions for spacesuit storage are required; and that a crew consisting of one driver/navigator and two field science crew specialists may be optimal. From a field operations viewpoint, a recurring conflict between rover and habitat crews at the time of return to the habitat was observed. An analysis of these incidents leads to proposed refinements of operational protocols, specific crew training for rover returns and again points to the need for a pressurised docking tunnel. Sound field testing, circulating of results, and building the lessons learned into new vehicles is advocated as a way of producing ever higher fidelity rover analogues.

  6. Numerical simulations of capillary barrier field tests

    SciTech Connect

    Morris, C.E.; Stormont, J.C.

    1997-12-31

    Numerical simulations of two capillary barrier systems tested in the field were conducted to determine if an unsaturated flow model could accurately represent the observed results. The field data was collected from two 7-m long, 1.2-m thick capillary barriers built on a 10% grade that were being tested to investigate their ability to laterally divert water downslope. One system had a homogeneous fine layer, while the fine soil of the second barrier was layered to increase its ability to laterally divert infiltrating moisture. The barriers were subjected first to constant infiltration while minimizing evaporative losses and then were exposed to ambient conditions. The continuous infiltration period of the field tests for the two barrier systems was modelled to determine the ability of an existing code to accurately represent capillary barrier behavior embodied in these two designs. Differences between the field test and the model data were found, but in general the simulations appeared to adequately reproduce the response of the test systems. Accounting for moisture retention hysteresis in the layered system will potentially lead to more accurate modelling results and is likely to be important when developing reasonable predictions of capillary barrier behavior.

  7. Photoreactivation of Escherichia coli following medium-pressure ultraviolet disinfection and its control using chloramination.

    PubMed

    Quek, P H; Hu, J Y; Chu, X N; Feng, Y Y; Tan, X L

    2006-01-01

    Ultraviolet (UV) disinfection is becoming increasingly popular as an alternative disinfection technology to chlorination in recent years. In this study, we investigated the photoreactivation of Escherichia coli following medium-pressure (MP) UV disinfection of synthetic water by a bench-scale collimated beam apparatus. The UV doses ranged from 1.6 -19.7 mWs/cm2 and photoreactivation was investigated for 6 hours under fluorescent light. In addition, chloramination was applied after UV disinfection to investigate its ability to control photoreactivation. It was found that photoreactivation occurred for all UV doses tested and the increase in bacteria numbers ranged from 0.04 to 1.35 log10. However, the degree of photoreactivation decreased with increased UV doses. Chloramination experiments revealed that the addition of 0.5 mg/l of monochloramine resulted in suppression of photoreactivation for 1 hour only. An increased monochloramine dose of 1 mg/l was found to prevent photoreactivation for the entire duration of the experiment. The results of this study have shown that photoreactivation occurs even after MP UV disinfection, although it is of a lesser extent at higher UV doses. This study has also established that secondary chloramination can effectively suppress and eliminate photoreactivation with a chloramine dose of 1 mg/l.

  8. Secondary hospital wastewater detoxification and disinfection by advanced oxidation processes.

    PubMed

    Machado, E L; Kist, L T; Schmidt, R; Hoeltz, J M; Dalberto, D; Alcayaga, E L A

    2007-10-01

    Secondary hospital wastewater treatment was investigated as an alternative to detoxification and disinfection after anaerobic digestion in a hospital located in southern Brazil. Tertiary and secondary effluents were assessed by general parameters. The use of advanced oxidation processes (UV/O3 and UV/TiO2/O3) showed potential capacity for disinfection and detoxification of wastewater effluents. The UV/TiO2/O3 method yielded the best results, decreasing toxicity of EC50 = 65 to nontoxic levels, also reducing MPN/100ml of 1.1 x 10(6) to values less than 2 and increasing wastewater biodegradability. The low energetic consumption of the proposed UV/TiO2/O3 method can be considered operationally advantageous.

  9. Recent advances in drinking water disinfection: successes and challenges.

    PubMed

    Ngwenya, Nonhlanhla; Ncube, Esper J; Parsons, James

    2013-01-01

    , it is recommended that water disinfection should never be compromised by attempting to control DBPs. The reason for this is that the risks of human illness and death from pathogens in drinking water are much greater than the risks from exposure to disinfectants and disinfection by-products. Nevertheless, if DBP levels exceed regulatory limits, strategies should focus on eliminating organic impurities that foster their formation, without compromising disinfection. As alternatives to chlorine, disinfectants such as chloramines, ozone, chlorine dioxide, and UV disinfection are gaining popularity. Chlorine and each of these disinfectants have individual advantage and disadvantage in terms of cost, efficacy-stability, ease of application, and nature of disinfectant by-products (DBPs). Based on efficiency, ozone is the most efficient disinfectant for inactivating bacteria, viruses, and protozoa. In contrast, chloramines are the least efficient and are not recommended for use as primary disinfectants. Chloramines are favored for secondary water disinfection, because they react more slowly than chlorine and are more persistent in distribution systems. In addition, chloramines produce lower DBP levels than does chlorine, although microbial activity in the distribution system may produce nitrate from monochloramine, when it is used as a residual disinfectant, Achieving the required levels of water quality, particularly microbial inactivation levels, while minimizing DBP formation requires the application of proper risk and disinfection management protocols. In addition, the failure of conventional treatment processes to eliminate critical waterborne pathogens in drinking water demand that improved and/or new disinfection technologies be developed. Recent research has disclosed that nanotechnology may offer solutions in this area, through the use of nanosorbents, nanocatalysts, bioactive nanoparticles, nanostructured catalytic membranes, and nanoparticle-enhanced filtration.

  10. Recent advances in drinking water disinfection: successes and challenges.

    PubMed

    Ngwenya, Nonhlanhla; Ncube, Esper J; Parsons, James

    2013-01-01

    , it is recommended that water disinfection should never be compromised by attempting to control DBPs. The reason for this is that the risks of human illness and death from pathogens in drinking water are much greater than the risks from exposure to disinfectants and disinfection by-products. Nevertheless, if DBP levels exceed regulatory limits, strategies should focus on eliminating organic impurities that foster their formation, without compromising disinfection. As alternatives to chlorine, disinfectants such as chloramines, ozone, chlorine dioxide, and UV disinfection are gaining popularity. Chlorine and each of these disinfectants have individual advantage and disadvantage in terms of cost, efficacy-stability, ease of application, and nature of disinfectant by-products (DBPs). Based on efficiency, ozone is the most efficient disinfectant for inactivating bacteria, viruses, and protozoa. In contrast, chloramines are the least efficient and are not recommended for use as primary disinfectants. Chloramines are favored for secondary water disinfection, because they react more slowly than chlorine and are more persistent in distribution systems. In addition, chloramines produce lower DBP levels than does chlorine, although microbial activity in the distribution system may produce nitrate from monochloramine, when it is used as a residual disinfectant, Achieving the required levels of water quality, particularly microbial inactivation levels, while minimizing DBP formation requires the application of proper risk and disinfection management protocols. In addition, the failure of conventional treatment processes to eliminate critical waterborne pathogens in drinking water demand that improved and/or new disinfection technologies be developed. Recent research has disclosed that nanotechnology may offer solutions in this area, through the use of nanosorbents, nanocatalysts, bioactive nanoparticles, nanostructured catalytic membranes, and nanoparticle-enhanced filtration

  11. Field Test Kit for Gun Residue Detection

    SciTech Connect

    WALKER, PAMELA K.; RODACY, PHILIP J.

    2002-01-01

    One of the major needs of the law enforcement field is a product that quickly, accurately, and inexpensively identifies whether a person has recently fired a gun--even if the suspect has attempted to wash the traces of gunpowder off. The Field Test Kit for Gunshot Residue Identification based on Sandia National Laboratories technology works with a wide variety of handguns and other weaponry using gunpowder. There are several organic chemicals in small arms propellants such as nitrocellulose, nitroglycerine, dinitrotoluene, and nitrites left behind after the firing of a gun that result from the incomplete combustion of the gunpowder. Sandia has developed a colorimetric shooter identification kit for in situ detection of gunshot residue (GSR) from a suspect. The test kit is the first of its kind and is small, inexpensive, and easily transported by individual law enforcement personnel requiring minimal training for effective use. It will provide immediate information identifying gunshot residue.

  12. A novel fiber optical device for ultraviolet disinfection of water.

    PubMed

    Lu, Gang; Li, Chaolin; Zheng, Yinggang; Zhang, Qian; Peng, Juan; Fu, Ming

    2008-07-24

    Since there are several problems in traditional UV disinfection techniques, a highly efficient, reliable and economical method, using quartz optical fibers to deliver UV light is proposed. The principle of the experimental setup is that ultraviolet rays are gathered by a reflector and converge on a light point, the diameter of approximately 5mm. In this way UV light can be transferred into water to kill the bacteria in the water. This paper presents preliminary results on water disinfection using this new UV disinfection setup. Its suitability for application could be shown in experiments with E. coli (ATCC8099) as test microorganisms. We have optimized the distribution of the optical fibers in the water in bench-scale study. This result can provide guidance for pilot-scale and field-scale study of this new technique. The results show that the new technique had a good performance under different conditions as follows: (a) turbidity level=10.2 NTU, (b) ferric ion concentration=0.3 mg/L, and (c) humic acid concentration=5 mg/L. The new technique provides a promising approach to disinfection treatment of drinking water.

  13. Modern technologies for improving cleaning and disinfection of environmental surfaces in hospitals.

    PubMed

    Boyce, John M

    2016-01-01

    Experts agree that careful cleaning and disinfection of environmental surfaces are essential elements of effective infection prevention programs. However, traditional manual cleaning and disinfection practices in hospitals are often suboptimal. This is often due in part to a variety of personnel issues that many Environmental Services departments encounter. Failure to follow manufacturer's recommendations for disinfectant use and lack of antimicrobial activity of some disinfectants against healthcare-associated pathogens may also affect the efficacy of disinfection practices. Improved hydrogen peroxide-based liquid surface disinfectants and a combination product containing peracetic acid and hydrogen peroxide are effective alternatives to disinfectants currently in widespread use, and electrolyzed water (hypochlorous acid) and cold atmospheric pressure plasma show potential for use in hospitals. Creating "self-disinfecting" surfaces by coating medical equipment with metals such as copper or silver, or applying liquid compounds that have persistent antimicrobial activity surfaces are additional strategies that require further investigation. Newer "no-touch" (automated) decontamination technologies include aerosol and vaporized hydrogen peroxide, mobile devices that emit continuous ultraviolet (UV-C) light, a pulsed-xenon UV light system, and use of high-intensity narrow-spectrum (405 nm) light. These "no-touch" technologies have been shown to reduce bacterial contamination of surfaces. A micro-condensation hydrogen peroxide system has been associated in multiple studies with reductions in healthcare-associated colonization or infection, while there is more limited evidence of infection reduction by the pulsed-xenon system. A recently completed prospective, randomized controlled trial of continuous UV-C light should help determine the extent to which this technology can reduce healthcare-associated colonization and infections. In conclusion, continued efforts to

  14. Disinfecting personal protective equipment with pulsed xenon ultraviolet as a risk mitigation strategy for health care workers.

    PubMed

    Jinadatha, Chetan; Simmons, Sarah; Dale, Charles; Ganachari-Mallappa, Nagaraja; Villamaria, Frank Charles; Goulding, Nicole; Tanner, Benjamin; Stachowiak, Julie; Stibich, Mark

    2015-04-01

    The doffing of personal protective equipment (PPE) after contamination with pathogens such as Ebola poses a risk to health care workers. Pulsed xenon ultraviolet (PX-UV) disinfection has been used to disinfect surfaces in hospital settings. This study examined the impact of PX-UV disinfection on an Ebola surrogate virus on glass carriers and PPE material to examine the potential benefits of using PX-UV to decontaminate PPE while worn, thereby reducing the pathogen load prior to doffing. Ultraviolet (UV) safety and coverage tests were also conducted. PX-UV exposure resulted in a significant reduction in viral load on glass carriers and PPE materials. Occupational Safety and Health Administration-defined UV exposure limits were not exceeded during PPE disinfection. Predoffing disinfection with PX-UV has potential as an additive measure to the doffing practice guidelines. The PX-UV disinfection should not be considered sterilization; all PPE should still be considered contaminated and doffed and disposed of according to established protocols.

  15. IN SITU FIELD TESTING OF PROCESSES

    SciTech Connect

    J.S.Y. YANG

    2004-11-08

    The purpose of this scientific analysis report is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts and surface-based boreholes through unsaturated zone (UZ) tuff rock units. In situ testing, monitoring, and associated laboratory studies are conducted to directly assess and evaluate the waste emplacement environment and the natural barriers to radionuclide transport at Yucca Mountain. This scientific analysis report supports and provides data to UZ flow and transport model reports, which in turn contribute to the Total System Performance Assessment (TSPA) of Yucca Mountain, an important document for the license application (LA). The objectives of ambient field-testing activities are described in Section 1.1. This report is the third revision (REV 03), which supercedes REV 02. The scientific analysis of data for inputs to model calibration and validation as documented in REV 02 were developed in accordance with the Technical Work Plan (TWP) ''Technical Work Plan for: Performance Assessment Unsaturated Zone'' (BSC 2004 [DIRS 167969]). This revision was developed in accordance with the ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 1.2.4) for better integrated, consistent, transparent, traceable, and more complete documentation in this scientific analysis report and associated UZ flow and transport model reports. No additional testing or analyses were performed as part of this revision. The list of relevant acceptance criteria is provided by ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654]), Table 3-1. Additional deviations from the TWP regarding the features, events, and processes (FEPs) list are discussed in Section 1.3. Documentation in this report includes descriptions of how, and under what conditions, the tests were conducted. The descriptions and

  16. Bistatic radar sea state monitoring field test

    NASA Technical Reports Server (NTRS)

    Ruck, G. T.; Kirchbaum, G. K.; Everly, J. O.

    1975-01-01

    Recent advances in understanding the physical phenomena controlling the interaction of electromagnetic energy with the ocean surface have revealed the possiblity of remote measurement of the two-dimensional surface wave height spectrum of the ocean using bistatic radar techniques. The basic feasibility of such a technique operating at frequencies in the HF region (3 to 30 MHz) was examined during previous studies and hardware for an experimental verification experiment was specified. The activities have resulted in a determination of the required hardware and system parameters for both satellite and aircraft systems, the development, assembly, and testing of hardware for an experimental aircraft system, the development and initial testing of data processing procedures, and the conduct of an initial flight test experiment. Activities were devoted to completing the assembly and testing of the experimental hardware, completing the experiment planning, conducting a field test experiment, and the processing and analysis of the experimental data. Even though directional spectrum maps of the test area cannot be generated from the measured data, the hardware concept employed appears viable, and solutions to the problems encountered have been identified.

  17. Cooperative field test program for wind systems

    SciTech Connect

    Bollmeier, W.S. II; Dodge, D.M.

    1992-03-01

    The objectives of the Federal Wind Energy Program, managed by the US Department of Energy (DOE), are (1) to assist industry and utilities in achieving a multi-regional US market penetration of wind systems, and (2) to establish the United States as the world leader in the development of advanced wind turbine technology. In 1984, the program conducted a series of planning workshops with representatives from the wind energy industry to obtain input on the Five-Year Research Plan then being prepared by DOE. One specific suggestion that came out of these meetings was that the federal program should conduct cooperative research tests with industry to enhance the technology transfer process. It was also felt that the active involvement of industry in DOE-funded research would improve the state of the art of wind turbine technology. DOE established the Cooperative Field Test Program (CFTP) in response to that suggestion. This program was one of the first in DOE to feature joint industry-government research test teams working toward common objectives.

  18. Trip Report-Produced-Water Field Testing

    SciTech Connect

    Sullivan, Enid J.

    2012-05-25

    Los Alamos National Laboratory (LANL) conducted field testing of a produced-water pretreatment apparatus with assistance from faculty at the Texas A&M University (TAMU) protein separation sciences laboratory located on the TAMU main campus. The following report details all of the logistics surrounding the testing. The purpose of the test was to use a new, commercially-available filter media housing containing modified zeolite (surfactant-modified zeolite or SMZ) porous medium for use in pretreatment of oil and gas produced water (PW) and frac-flowback waters. The SMZ was tested previously in October, 2010 in a lab-constructed configuration ('old multicolumn system'), and performed well for removal of benzene, toluene, ethylbenzene, and xylenes (BTEX) from PW. However, a less-expensive, modular configuration is needed for field use. A modular system will allow the field operator to add or subtract SMZ filters as needed to accommodate site specific conditions, and to swap out used filters easily in a multi-unit system. This test demonstrated the use of a commercial filter housing with a simple flow modification and packed with SMZ for removing BTEX from a PW source in College Station, Texas. The system will be tested in June 2012 at a field site in Pennsylvania for treating frac-flowback waters. The goals of this test are: (1) to determine sorption efficiency of BTEX in the new configuration; and (2) to observe the range of flow rates, backpressures, and total volume treated at a given flow rate.

  19. 3X-100 blade field test.

    SciTech Connect

    Zayas, Jose R.; Johnson, Wesley D.

    2008-03-01

    In support of a Work-For-Other (WFO) agreement between the Wind Energy Technology Department at Sandia National Laboratories and 3TEX, one of the three Micon 65/13M wind turbines at the USDA Agriculture Research Service (ARS) center in Bushland, Texas, has been used to test a set of 9 meter wind turbine blades, manufactured by TPI composites using the 3TEX carbon material for the spar cap. Data collected from the test has been analyzed to evaluate both the aerodynamic performance and the structural response from the blades. The blades aerodynamic and structural performance, the meteorological inflow and the wind turbine structural response has been monitored with an array of 57 instruments: 15 to characterize the blades, 13 to characterize inflow, and 15 to characterize the time-varying state of the turbine. For the test, data was sampled at a rate of 40 Hz using the ATLAS II (Accurate GPS Time-Linked Data Acquisition System) data acquisition system. The system features a time-synchronized continuous data stream and telemetered data from the turbine rotor. This paper documents the instruments and infrastructure that have been developed to monitor these blades, turbines and inflow, as well as both modeling and field testing results.

  20. III-Nitride UV Devices

    NASA Astrophysics Data System (ADS)

    Asif Khan, M.; Shatalov, M.; Maruska, H. P.; Wang, H. M.; Kuokstis, E.

    2005-10-01

    The need for efficient, compact and robust solid-state UV optical sources and sensors had stimulated the development of optical devices based on III-nitride material system. Rapid progress in material growth, device fabrication and packaging enabled demonstration of high efficiency visible-blind and solar-blind photodetectors, deep-UV light-emitting diodes with emission from 400 to 250 nm, and UV laser diodes with operation wavelengths ranging from 340 to 350 nm. Applications of these UV optical devices include flame sensing; fluorescence-based biochemical sensing; covert communications; air, water and food purification and disinfection; and biomedical instrumentation. This paper provides a review of recent advances in the development of UV optical devices. Performance of state-of-the-art devices as well as future prospects and challenges are discussed.

  1. 40 CFR 1065.925 - PEMS preparation for field testing.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false PEMS preparation for field testing. 1065.925 Section 1065.925 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Field Testing and Portable Emission Measurement Systems § 1065.925 PEMS preparation for field testing....

  2. Essential oils for the disinfection of grey water.

    PubMed

    Winward, Gideon P; Avery, Lisa M; Stephenson, Tom; Jefferson, Bruce

    2008-04-01

    Although the antimicrobial properties of many plant essential oils (EOs) are well known, their application for the disinfection of water has received little attention. In this study, their use as alternative 'natural' disinfectants for grey water reuse was assessed. Toxicity screening of eight EOs and their components highlighted origanum oil (Thymus capitatus) and carvacrol as exerting the most antimicrobial activity. Over a 30-min contact time, origanum EO concentrations of up to 94 mg L(-1) had minimal effect on total coliform concentrations in the grey water while a concentration of 468 mg L(-1) rendered total coliforms non-detectable in 100mL grey water. Coliform inactivation was found to increase with EO contact time. Organic concentration and particulate size in grey water were shown to reduce the efficacy of disinfection with origanum EO. Origanum EO prevented regrowth of coliform bacteria in reed bed-treated grey water for up to 14 days at a concentration of 468 mg L(-1), with or without prior disinfection by ultraviolet (UV) light. Based on the disinfection data reported here, the production of sufficient origanum EO for the disinfection of grey water for reuse with toilet flushing, would require approximately 35 times the average land area of a UK household.

  3. In Situ Field Testing of Processes

    SciTech Connect

    J. Wang

    2001-12-14

    The purpose of this Analysis/Model Report (AMR) is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts of the Yucca Mountain Site Characterization Project (YMP). This revision updates data and analyses presented in the initial issue of this AMR. This AMR was developed in accordance with the ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' and ''Technical Work Plan for UZ Flow, Transport, and Coupled Processes Process Model Report. These activities were performed to investigate in situ flow and transport processes. The evaluations provide the necessary framework to: (1) refine and confirm the conceptual model of matrix and fracture processes in the unsaturated zone (UZ) and (2) analyze the impact of excavation (including use of construction water and effect of ventilation) on the UZ flow and transport processes. This AMR is intended to support revisions to ''Conceptual and Numerical Models for UZ Flow and Transport'' and ''Unsaturated Zone Flow and Transport Model Process Model Report''. In general, the results discussed in this AMR are from studies conducted using a combination or a subset of the following three approaches: (1) air-injection tests, (2) liquid-release tests, and (3) moisture monitoring using in-drift sensors or in-borehole sensors, to evaluate the impact of excavation, ventilation, and construction-water usage on the surrounding rocks. The liquid-release tests and air-injection tests provide an evaluation of in situ fracture flow and the competing processes of matrix imbibition. Only the findings from testing and data not covered in the ''Seepage Calibration Model and Seepage Testing Data'' are analyzed in detail in the AMR.

  4. Field testing of asphalt-emulsion radon-barrier system

    SciTech Connect

    Hartley, J.N.; Freeman, H.D.; Baker, E.G.; Elmore, M.R.; Nelson, D.A.; Voss, C.F.; Koehmstedt, P.L.

    1981-09-01

    Three years of laboratory and field testing have demonstrated that asphalt emulsion seals are effective radon diffusion barriers. Both laboratory and field tests in 1979, 1980 and 1981 have shown that an asphalt emulsion seal can reduce radon fluxes by greater than 99.9%. The effective diffusion coefficient for the various asphalt emulsion admix seals averages about 10/sup -6/ cm/sup 2//s. The 1981 joint field test is a culmination of all the technology developed to date for asphalt emulsion radon barrier systems. Preliminary results of this field test and the results of the 1980 field test are presented. 18 figures, 6 tables.

  5. FIELD TEST OF THE FLAME QUALITY INDICATOR

    SciTech Connect

    Rudin, Andrew M; Butcher, Thomas; Troost, Henry

    2003-02-04

    The flame quality indicator concept was developed at BNL specifically to monitor the brightness of the flame in a small oil burner and to provide a ''call for service'' notification when the brightness has changed from its setpoint, either high or low. In prior development work BNL has explored the response of this system to operational upsets such as excess air changes, fouled atomizer nozzles, poor fuel quality, etc. Insight Technologies, Inc. and Honeywell, Inc. have licensed this technology from the U.S. Department of Energy and have been cooperating to develop product offerings which meet industry needs with an optimal combination of function and price. Honeywell has recently completed the development of the Flame Quality Monitor (FQM or Honeywell QS7100F). This is a small module which connects via a serial cable to the burners primary operating control. Primary advantages of this approach are simplicity, cost, and ease of installation. Call-for-service conditions are output in the form of front panel indicator lights and contact closure which can trigger a range of external communication options. Under this project a field test was conducted of the FQM in cooperation with service organizations in Virginia, Pennsylvania, New Jersey, New York, and Connecticut. At total of 83 field sites were included. At each site the FQM was installed in parallel with another embodiment of this concept--the Insight AFQI. The AFQI incorporates a modem and provides the ability to provide detailed information on the trends in the flame quality over the course of the two year test period. The test site population was comprised of 79.5% boilers, 13.7% warm air furnaces, and 6.8% water heaters. Nearly all were of residential size--with firing rates ranging from 0.6 gallons of oil per hour to 1.25. During the course of the test program the monitoring equipment successfully identified problems including: plugged fuel lines, fouled nozzles, collapsed combustion chambers, and poor fuel

  6. CHLORINE DISINFECTION OF AEROMONAS

    EPA Science Inventory

    The bacterial genus Aeromonas is currently listed on the USEPA's Candidate Contaminant List (CCL). Resistance to chemical disinfection is an essential aspect regarding all microbial groups listed on the CCL. This study was designed to determine the inactivation kinetics of Aeromo...

  7. [Use od ozone for disinfection of ships' system of water supply contaminated by Pseudomonas aeruginosa].

    PubMed

    Rakhmanin, Iu A; Strikalenko, T V; Mokienko, A V; Stoianova, N V; Gutsel', Iu I

    1990-11-01

    Experimental substantiation is given of the use of ozone in doses, recommended for disinfection of water and ship water supply systems infected by Pseudomonas aeruginosa. The positive effect of ozonation of water supply systems infected by Pseudomonas aeruginosa was confirmed by results of field testing on ships of the Black sea marine steam-navigation.

  8. Medical Devices; General Hospital and Personal Use Devices; Classification of the Ultraviolet Radiation Chamber Disinfection Device. Final order.

    PubMed

    2015-11-20

    The Food and Drug Administration (FDA or the Agency) is classifying the ultraviolet (UV) radiation chamber disinfection device into class II (special controls). The special controls that will apply to the device are identified in this order and will be part of the codified language for the UV radiation chamber disinfection device classification. The Agency is classifying the device into class II (special controls) in order to provide a reasonable assurance of safety and effectiveness of the device.

  9. Medical Devices; General Hospital and Personal Use Devices; Classification of the Ultraviolet Radiation Chamber Disinfection Device. Final order.

    PubMed

    2015-11-20

    The Food and Drug Administration (FDA or the Agency) is classifying the ultraviolet (UV) radiation chamber disinfection device into class II (special controls). The special controls that will apply to the device are identified in this order and will be part of the codified language for the UV radiation chamber disinfection device classification. The Agency is classifying the device into class II (special controls) in order to provide a reasonable assurance of safety and effectiveness of the device. PMID:26595943

  10. Disinfection of secondary effluents by infiltration percolation.

    PubMed

    Makni, H

    2001-01-01

    Among the most attractive applications of reclaimed wastewater are: irrigation of public parks, sports fields, golf courses and market gardening. These uses require advanced wastewater treatment including disinfection. According to WHO guidelines (1989) and current rules and regulations in Tunisia, faecal coliform levels have to be reduced to < 10(3) or 10(2) CFU/100 mL. In Tunisia, most wastewater plants are only secondary treatment and, in order to meet health related regulations, the effluents need to be disinfected. However, it is usual for secondary effluents to need filtration prior to disinfection. Effectiveness of conventional disinfection processes, such as chlorination and UV radiation, are dependent upon the oxidation level and the levels of suspended solids of the treated water. Ozonation is relatively expensive and energy consuming. The consideration of the advantages and disadvantages of conventional techniques, their reliability, investment needs and operational costs will lead to the use of less sophisticated alternative techniques for certain facilities. Among alternative techniques, soil aquifer treatment and infiltration percolation through sand beds have been studied in Arizona, Israel, France, Spain and Morocco. Infiltration percolation plants have been intermittently fed with secondary or high quality primary effluents which percolated through 1.5-2 m unsaturated coarse sand and were recovered by under-drains. In such infiltration percolation facilities, microorganisms were eliminated through numerous physical, physicochemical and biological inter-related processes (mechanical filtration, adsorption and microbial degradation respectively). Efficiency of faecal coliform removal was dependent upon the water detention times in the filtering medium and on the oxidation of the filtered water. Effluents of Sfax town aerated ponds were infiltrated through 1.5 m deep sand columns in order to determine the performance of infiltration percolation in the

  11. Effects of ultraviolet light disinfection on tetracycline-resistant bacteria in wastewater effluents.

    PubMed

    Childress, H; Sullivan, B; Kaur, J; Karthikeyan, R

    2014-09-01

    The ubiquitous use of antibiotics has led to an increasing number of antibiotic-resistant bacterial strains, including strains that are multidrug-resistant, pathogenic, or both. There is also evidence to suggest that antibiotic resistance genes (ARGs) spread to the environment, humans, and animals through wastewater effluents. The overall objective of this study was to investigate the effect of ultraviolet (UV) light disinfection on antibiotic-resistant bacteria. Wastewater effluent samples from a wastewater treatment plant (WWTP) in Texas were evaluated for differences in tetracycline-resistant bacteria before and after UV treatment. The effects of photoreactivation or dark repair on the reactivation of bacteria present in WWTP effluent after UV disinfection were also examined. Culture-based methods were used to characterize viable heterotrophic, tetracycline-resistant heterotrophic, Escherichia coli, and tetracycline-resistant E. coli bacteria present before and after UV treatment. UV disinfection was found to be as effective at reducing concentrations of resistant heterotrophs and E. coli, as it was at reducing total bacterial concentrations. The lowest survival ratio following UV disinfection was observed in tetracycline-resistant E. coli showing particular susceptibility to UV treatment. Photoreactivation and dark repair rates were found to be comparable to each other for all bacterial populations.

  12. Commercial Disinfectants During Disinfection Process Validation: More Failures than Success

    PubMed Central

    Chumber, Sushil Kumar; Khanduri, Uma

    2016-01-01

    Introduction Disinfection process validation is mandatory before introduction of a new disinfectant in hospital services. Commercial disinfection brands often question existing hospital policy claiming greater efficacy and lack of toxicity of their products. Inadvertent inadequate disinfection leads to morbidity, patient’s economic burden, and the risk of mortality. Aim To evaluate commercial disinfectants for high, intermediate and low-level disinfection so as to identify utility for our routine situations. Materials and Methods This laboratory based experiment was conducted at St Stephen Hospital, Delhi during July-September 2013. Twelve commercial disinfectants: Sanidex®, Sanocid®, Cidex®, SekuSept Aktiv®, BIB Forte®, Alprojet W®, Desnet®, Sanihygiene®, Incidin®, D125®, Lonzagard®, and Glutishield® were tested. Time-kill assay (suspension test) was performed against six indicator bacteria (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella Typhi, Bacillus cereus, and Mycobacterium fortuitum). Low and high inoculum (final concentrations 1.5X106 and 9X106 cfu/ml) of the first five bacteria while only low level of M. fortuitum was tested. Results Cidex® (2.4% Glutaraldehyde) performed best as high level disinfectant while newer quarternary ammonium compounds (QACs) (Incidin®, D125®, and Lonzagard®) were good at low level disinfection. Sanidex® (0.55% Ortho-pthalaldehyde) though mycobactericidal took 10 minutes for sporicidal activity. Older QAC containing BIB Forte® and Desnet® took 20 minutes to fully inhibit P. aeruginosa. All disinfectants effectively reduced S. Typhi to zero counts within 5 minutes. Conclusion Cidex® is a good high-level disinfectant while newer QACs (Incidin®, D125®, and Lonzagard®) were capable low-level disinfectants. PMID:27656441

  13. New Water Disinfection Technology for Earth and Space Applications as Part of the NPP Fellowship Research

    NASA Technical Reports Server (NTRS)

    SilvestryRodriquez, Nadia

    2010-01-01

    There is the need for a safe, low energy consuming and compact water disinfection technology to maintain water quality for human consumption. The design of the reactor should present no overheating and a constant temperature, with good electrical and optical performance for a UV water treatment system. The study assessed the use of UVA-LEDs to disinfectant water for MS2 Bacteriophage. The log reduction was sufficient to meet US EPA standards as a secondary disinfectant for maintaining water quality control. The study also explored possible inactivation of Pseudomonas aeruginosa and E. coli.

  14. Visible light powered self-disinfecting coatings for influenza viruses

    NASA Astrophysics Data System (ADS)

    Weng, Ding; Qi, Hangfei; Wu, Ting-Ting; Yan, Ming; Sun, Ren; Lu, Yunfeng

    2012-04-01

    Influenza A viruses, the pathogens responsible for the recent swine flu outbreak and many historical pandemics, remain a threat to the public health. We report herein the fabrication of self-disinfecting surfaces from photoactive building nanocrystals, which can inactivate influenza viruses rapidly, spontaneously and continuously under visible light illumination.Influenza A viruses, the pathogens responsible for the recent swine flu outbreak and many historical pandemics, remain a threat to the public health. We report herein the fabrication of self-disinfecting surfaces from photoactive building nanocrystals, which can inactivate influenza viruses rapidly, spontaneously and continuously under visible light illumination. Electronic supplementary information (ESI) available: XRD, UV-Vis absorbance, TEM, AFM of as-prepared nanocrystals and as-fabricated self-disinfecting surfaces, disinfection of influenza A virus by TiO2 (P25) with UV irradiation as reference control, photoinactivation of influenza A virus envelope proteins and photoinactivation of trypsin. See DOI: 10.1039/c2nr30388d

  15. Disinfection of greywater effluent and regrowth potential of selected bacteria.

    PubMed

    Friedler, Eran; Yardeni, Anat; Gilboa, Yael; Alfiya, Yuval

    2011-01-01

    Chlorination and UV irradiation of RBC (rotating biological contactor)-treated light GW (greywater) was investigated. The ability of chlorine and UV to inactivate indictor bacteria (FC - Faecal Coliforms, HPC - Heterotrophic Plate Count) and specific pathogens (P.a. - Pseudomonas aeruginosa sp., S.a. - Staphylococcus aureus sp.), was assessed and their regrowth potential was examined. The RBC removed 88.5-99.9% of all four bacteria groups. Nevertheless, the treated GW had to be disinfected. Most of the chlorine was consumed during the first 0.5 h, while later its decay rate decreased significantly, leaving enough residual after 6 h to prevent regrowth and to further inactivate bacteria in the stored GW effluent. Under exposure to low UV doses (≤69 mJ/cm(2)) FC was the most resistant bacteria group, followed by HPC, P.a. and S.a. Exposure to higher doses (≤439 mJs/cm(2)) completely inactivated FC, P.a. and S.a., while no further HPC inactivation was observed. FC, P.a. and S.a. did not exhibit regrowth after exposure to all the UV doses applied (up to 6 h storage). HPC did not exhibit regrowth after exposure to low UV doses (19-69 mJ/cm2), while it presented statistically significant regrowth in un-disinfected effluent and after exposure to higher UV doses (147-439 mJ/cm(2)).

  16. Water disinfection through photoactive modified titania.

    PubMed

    Sethi, Diptipriya; Pal, Ajoy; Sakthivel, Ramasamy; Pandey, Sony; Dash, Tapan; Das, Trupti; Kumar, Rohit

    2014-01-01

    TiO(2), N-TiO(2) and S-TiO(2) samples have been prepared by various chemical methods. These samples were characterized by X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), Laser Raman spectrometer, UV-Visible spectrophotometer, field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM). X-ray powder diffraction study reveals that all three samples are single anatase phase of titania and the crystallinity of titania decreases with sulphur doping whereas nitrogen doping does not affect it. UV-Visible (diffuse) reflectance spectra shows that doping of titania with nitrogen and sulphur shift the absorption edge of titania from ultraviolet to visible region. XPS study confirms that both nitrogen and sulphur are well doped in the titania lattice. It is observed that nitrogen occupies at both substitutional and interstitial position in the lattice of titania. FE-SEM and TEM studies demonstrate that the particles are below 50nm range. It is found that S and N doping of titania increased its water disinfection property in the order TiO(2)UV/UV-Visible light irradiation.

  17. Disinfectants used for environmental disinfection and new room decontamination technology.

    PubMed

    Rutala, William A; Weber, David J

    2013-05-01

    Environmental contamination plays an important role in the transmission of several key health care-associated pathogens. Effective and thorough cleaning/disinfecting of the patient environment is essential. Room decontamination units (such as ultraviolet-C and hydrogen peroxide systems) aid in reducing environmental contamination after terminal room cleaning and disinfection.

  18. “Evaluation of the Effect of Ultraviolet Disinfection on Dimensional Stability of the Polyvinyl Silioxane Impressions.” an in-Vitro Study

    PubMed Central

    Godbole, Surekha R; Dahane, Trupti M; Nimonkar, Sharayu V

    2014-01-01

    Introduction: Infection control is an important concept in the present day practice of dentistry. The prosthodontists are at an added risk of transmission because of the infection spreading through the contaminated lab equipments while working in the lab. The purpose of this study is to evaluate the effect of UV light disinfection on dimensional stability of polyvinyl siloxane impressions. Materials and Methods : Impressions were made in perforated custom tray. After polymerization of impression, half the samples were disinfected in UV light and remaining samples were not subjected to disinfection and poured in die stone which served as control group. Linear dimensions were measured on the cast with travelling microscope of 0.001accuracy. Result : The result showed that UV light disinfectant showed no significant dimensional changes on impressions. Conclusion: Hence, it can be safely used to disinfect impressions in clinical prosthodontic procedures. PMID:25386528

  19. Point-of-use water disinfection using ultraviolet and visible light-emitting diodes.

    PubMed

    Lui, Gough Yumu; Roser, David; Corkish, Richard; Ashbolt, Nicholas J; Stuetz, Richard

    2016-05-15

    Improvements in point-of-use (POU) drinking water disinfection technologies for remote and regional communities are urgently needed. Conceptually, UV-C light-emitting diodes (LEDs) overcome many drawbacks of low-pressure mercury tube based UV devices, and UV-A or visible light LEDs also show potential. To realistically evaluate the promise of LED disinfection, our study assessed the performance of a model 1.3 L reactor, similar in size to solar disinfection bottles. In all, 12 different commercial or semi-commercial LED arrays (270-740 nm) were compared for their ability to inactivate Escherichia coli K12 ATCC W3110 and Enterococcus faecalis ATCC 19433 over 6h. Five log10 and greater reductions were consistently achieved using the 270, 365, 385 and 405 nm arrays. The output of the 310 nm array was insufficient for useful disinfection while 430 and 455 nm performance was marginal (≈ 4.2 and 2.3-log10s E. coli and E. faecalis over the 6h). No significant disinfection was observed with the 525, 590, 623, 660 and 740 nm arrays. Delays in log-phase inactivation of E. coli were observed, particularly with UV-A wavelengths. The radiation doses required for >3-log10 reduction of E. coli and E. faecalis differed by 10 fold at 270 nm but only 1.5-2.5 fold at 365-455 nm. Action spectra, consistent with the literature, were observed with both indicators. The design process revealed cost and technical constraints pertaining to LED electrical efficiency, availability and lifetime. We concluded that POU LED disinfection using existing LED technology is already technically possible. UV-C LEDs offer speed and energy demand advantages, while UV-A/violet units are safer. Both approaches still require further costing and engineering development. Our study provides data needed for such work. PMID:26967007

  20. DISINFECTION BYPRODUCTS: THE NEXT GENERATION

    EPA Science Inventory

    Disinfection of drinking water is rightly hailed as a major public health triumph of the 20th Century. Before widespread disinfection of drinking water in the U.S. and Europe, millions of people died from infectious waterborne diseases, such as typhoid and cholera. The microbia...

  1. Sanitizers and Disinfectants Guide. Revised

    ERIC Educational Resources Information Center

    Healthy Schools Network, Inc., 2012

    2012-01-01

    Sanitizers and disinfectants can play an important role in protecting public health. They are designed to kill "pests," including infectious germs and other microorganisms such as bacteria, viruses, and fungi. Unfortunately, sanitizers and disinfectants also contain chemicals that are "pesticides." Exposure to persistent toxic chemicals in…

  2. Ultraviolet radiation as disinfection for fish surgical tools

    SciTech Connect

    Walker, Ricardo W.; Markillie, Lye Meng; Colotelo, Alison HA; Geist, David R.; Gay, Marybeth E.; Woodley, Christa M.; Eppard, M. B.; Brown, Richard S.

    2013-04-04

    Telemetry is frequently used to examine the behavior of fish, and the transmitters used are normally surgically implanted into the coelomic cavity of fish. Implantation requires the use of surgical tools such as scalpels, forceps, needle holders, and sutures. When fish are implanted consecutively, as in large telemetry studies, it is common for surgical tools to be sterilized or, at minimum, disinfected between each use so that pathogens that may be present are not spread among fish. To determine the efficacy for this application, ultraviolet (UV) radiation was used to disinfect surgical tools exposed to one of four aquatic organisms that typically lead to negative health issues for salmonids. These organisms included Aeromonas salmonicida, Flavobacterium psychrophilum, Renibacterium salmoninarum, and Saprolegnia parasitica, causative agents of furunculosis, coldwater disease, bacterial kidney disease, and saprolegniasis (water mold), respectively. Four experiments were conducted to address the question of UV efficacy. In the first experiment, forceps were exposed to the three bacteria at three varying concentrations. After exposure to the bacterial culture, tools were placed into a mobile Millipore UV sterilization apparatus. The tools were then exposed for three different time periods – 2, 5, or 15 min. UV radiation exposures at all durations were effective at killing all three bacteria on forceps at the highest bacteria concentrations. In the second experiment, stab scalpels, sutures, and needle holders were exposed to A. salmonicida using the same methodology as used in Experiment 1. UV radiation exposure at 5 and 15 min was effective at killing A. salmonicida on stab scalpels and sutures but not needle holders. In the third experiment, S. parasitica, a water mold, was tested using an agar plate method and forceps-pinch method. UV radiation was effective at killing the water mold at all three exposure durations. Collectively, this study shows that UV

  3. Disinfection of pumice.

    PubMed

    Setz, J; Heeg, P

    1996-10-01

    Pumice is a potential source of infection for the dental technician and of cross-contamination between different dentures and patients. In this study, the number of microorganisms in two different combinations of pumice and disinfectant was compared with a conventional mixture of pumice and water. The results revealed that under practical conditions the mix of Steribim (pumice containing benzoic acid added by the manufacturer) with water reduced the number of bacteria by 99% compared with a mix of a conventional pumice and water. The addition of an antiseptic product that contained octenidine as active agent to conventional pumice reduced the number of microorganisms by 99.999%.

  4. Inactivation of antibiotic resistance genes in municipal wastewater by chlorination, ultraviolet, and ozonation disinfection.

    PubMed

    Zhuang, Yao; Ren, Hongqiang; Geng, Jinju; Zhang, Yingying; Zhang, Yan; Ding, Lili; Xu, Ke

    2015-05-01

    This study investigated the inactivation of two antibiotic resistance genes (ARGs)-sul1 and tetG, and the integrase gene of class 1 integrons-intI1 by chlorination, ultraviolet (UV), and ozonation disinfection. Inactivation of sul1, tetG, and intI1 underwent increased doses of three disinfectors, and chlorine disinfection achieved more inactivation of ARGs and intI1 genes (chlorine dose of 160 mg/L with contact time of 120 min for 2.98-3.24 log reductions of ARGs) than UV irradiation (UV dose of 12,477 mJ/cm(2) for 2.48-2.74 log reductions of ARGs) and ozonation disinfection (ozonation dose of 177.6 mg/L for 1.68-2.55 log reductions of ARGs). The 16S rDNA was more efficiently removed than ARGs by ozone disinfection. The relative abundance of selected genes (normalized to 16S rDNA) increased during ozonation and with low doses of UV and chlorine disinfection. Inactivation of sul1 and tetG showed strong positive correlations with the inactivation of intI1 genes (for sul1, R (2)  = 0.929 with p < 0.01; for tetG, R (2)  = 0.885 with p < 0.01). Compared to other technologies (ultraviolet disinfection, ozonation disinfection, Fenton oxidation, and coagulation), chlorination is an alternative method to remove ARGs from wastewater effluents. At a chlorine dose of 40 mg/L with 60 min contact time, the selected genes inactivation efficiency could reach 1.65-2.28 log, and the cost was estimated at 0.041 yuan/m(3).

  5. Occurrence and exposures to disinfectants and disinfection by-products

    SciTech Connect

    Cumming, R.B.; Jolley, R.L.

    1992-12-31

    Disinfection by-products are associated with all chemical disinfectants. The concentration and toxic nature of the disinfection byproducts (DBPs) is a direct function of the chemical nature of the disinfectant itself and/or of the chemical reactions of the disinfectant with reaction substrates in the water, especially organic constituents. A principal advantage of biological and physical water treatment processes, such as filtration, is the lack of chemical reactions producing disinfectant-related DBPs. The use of the highest quality source water available is important for minimization of DBP formation. In lieu of such high quality water, improvement of water quality by removal of DBP precursors through filtration or other means before application of chemical disinfectants is important. Most, if not all, water treatment experts are aware of these simplistic axioms. In view of the increasing knowledge being developed concerning DBPs including the identification of ``new`` DBPs, prudence dictates minimization of DBP formation. Wholesome drinking water is perhaps the biggest economic bargain available to consumers. The cost-effectiveness of water quality improvement should be evaluated with that in mind.

  6. Occurrence and exposures to disinfectants and disinfection by-products

    SciTech Connect

    Cumming, R.B.; Jolley, R.L.

    1992-01-01

    Disinfection by-products are associated with all chemical disinfectants. The concentration and toxic nature of the disinfection byproducts (DBPs) is a direct function of the chemical nature of the disinfectant itself and/or of the chemical reactions of the disinfectant with reaction substrates in the water, especially organic constituents. A principal advantage of biological and physical water treatment processes, such as filtration, is the lack of chemical reactions producing disinfectant-related DBPs. The use of the highest quality source water available is important for minimization of DBP formation. In lieu of such high quality water, improvement of water quality by removal of DBP precursors through filtration or other means before application of chemical disinfectants is important. Most, if not all, water treatment experts are aware of these simplistic axioms. In view of the increasing knowledge being developed concerning DBPs including the identification of new'' DBPs, prudence dictates minimization of DBP formation. Wholesome drinking water is perhaps the biggest economic bargain available to consumers. The cost-effectiveness of water quality improvement should be evaluated with that in mind.

  7. Photovoltaic-Powered Vaccine Refrigerator: Freezer Systems Field Test Results

    NASA Technical Reports Server (NTRS)

    Ratajczak, A. F.

    1985-01-01

    A project to develop and field test photovoltaic-powered refrigerator/freezers suitable for vaccine storage was undertaken. Three refrigerator/freezers were qualified; one by Solar Power Corp. and two by Solvolt. Follow-on contracts were awarded for 19 field test systems and for 10 field test systems. A total of 29 systems were installed in 24 countries between October 1981 and October 1984. The project, systems descriptions, installation experiences, performance data for the 22 systems for which field test data was reported, an operational reliability summary, and recommendations relative to system designs and future use of such systems are explained. Performance data indicate that the systems are highly reliable and are capable of maintaining proper vaccine storage temperatures in a wide range of climatological and user environments.

  8. Photovoltaic-powered vaccine refrigerator: Freezer systems field test results

    NASA Astrophysics Data System (ADS)

    Ratajczak, A. F.

    1985-08-01

    A project to develop and field test photovoltaic-powered refrigerator/freezers suitable for vaccine storage was undertaken. Three refrigerator/freezers were qualified; one by Solar Power Corp. and two by Solvolt. Follow-on contracts were awarded for 19 field test systems and for 10 field test systems. A total of 29 systems were installed in 24 countries between October 1981 and October 1984. The project, systems descriptions, installation experiences, performance data for the 22 systems for which field test data was reported, an operational reliability summary, and recommendations relative to system designs and future use of such systems are explained. Performance data indicate that the systems are highly reliable and are capable of maintaining proper vaccine storage temperatures in a wide range of climatological and user environments.

  9. Field Testing Research at the NWTC (Fact Sheet)

    SciTech Connect

    Not Available

    2015-02-01

    The National Wind Technology Center (NWTC) at the National Renewable Laboratory (NREL) has extensive field testing capabilities that have been used in collaboration with the wind industry to accelerate wind technology development and deployment for more than 30 years.

  10. Effect of chlorination and ultraviolet disinfection on tetA-mediated tetracycline resistance of Escherichia coli.

    PubMed

    Huang, Jing-Jing; Hu, Hong-Ying; Wu, Yin-Hu; Wei, Bin; Lu, Yun

    2013-02-01

    Antibiotic-resistant bacteria are an emerging threat to public health during drinking water consumption and reclaimed water reuse. Several studies have shown that the proportions of antibiotic-resistant bacteria in waters may increase when exposed to low doses of UV light or chlorine. In this study, inactivation of tetracycline-resistant Escherichia coli and antibiotic-sensitive E. coli by UV disinfection and chlorination was compared to determine the tolerance of tetracycline-resistant E. coli to UV light and chlorine, and tetracycline resistance of a tetracycline-resistant E. coli population was studied under different doses of the disinfectants. Our results showed that relative to antibiotic-sensitive E. coli, tetracycline-resistant E. coli had the same tolerance to UV light and a potentially higher tolerance to chlorination. The mortality frequency distributions of tetracycline-resistant E. coli exposed to tetracycline were shifted by both chlorination and UV disinfection. When compared to the hemi-inhibitory concentrations (IC(50)) of tetracycline-resistant E. coli with no exposure to UV or chlorination, the IC(50) of tetracycline-resistant E. coli treated with tetracycline was 40% lower when inactivation by UV light or chlorination reached 3-log but was 1.18 times greater when inactivation by chlorination reached 4.3-log. Chlorination applied to drinking water or reclaimed water treatment may increase the risk of selection for highly tetracycline-resistant E. coli.

  11. Dental unit waterlines disinfection using hypochlorous acid-based disinfectant

    PubMed Central

    Shajahan, Irfana Fathima; Kandaswamy, D; Srikanth, Padma; Narayana, L Lakshmi; Selvarajan, R

    2016-01-01

    Objective: The purpose of the study was to investigate the efficacy of a new disinfectant to disinfect the dental unit waterlines. Materials and Methods: New dental unit waterlines were installed in 13 dental chairs, and biofilm was allowed to grow for 10 days. Disinfection treatment procedure was carried out in the 12 units, and one unit was left untreated. The dental unit waterlines were removed and analyzed using the scanning electron microscope (SEM) (TESCAN VEGA3 SBU). Result: On examination, SEM images showed that there was no slime layer or bacterial cells seen in any of the 12 cut sections obtained from the treated dental waterlines which mean that there was no evident of biofilm formation. Untreated dental unit waterlines showed a microbial colonization with continuous filamentous organic matrix. There was significant biofilm formation in the control tube relative to the samples. Conclusion: The tested disinfectant was found to be effective in the removal of biofilm from the dental unit waterlines. PMID:27563184

  12. Halonitroalkanes, halonitriles, haloamides, and N-nitrosamines: a critical review of nitrogenous disinfection byproduct formation pathways.

    PubMed

    Shah, Amisha D; Mitch, William A

    2012-01-01

    Interest in the formation of nitrogenous disinfection byproducts (N-DBPs) has increased because toxicological research has indicated that they are often more genotoxic, cytotoxic, or carcinogenic than many of the carbonaceous disinfection byproducts (C-DBPs) that have been a focus for previous research. Moreover, population growth has forced utilities to exploit source waters impaired by wastewater effluents or algal blooms. Both waters feature higher levels of organic nitrogen, that might serve as N-DBP precursors. Utilities are exploring new disinfectant combinations to reduce the formation of regulated trihalomethanes and haloacetic acids. As some of these new combinations may promote N-DBP formation, characterization of N-DBP formation pathways is needed. Formation pathways for halonitroalkanes, halonitriles, haloamides, and N-nitrosamines associated with chlorine, ozone, chlorine dioxide, UV, and chloramine disinfection are critically reviewed. Several important themes emerge from the review. First, the formation pathways of the N-DBP families are partially linked because most of the pathways involve similar amine precursors. Second, it is unlikely that a disinfection scheme that is free of byproduct formation will be discovered. Disinfectant combinations should be optimized to reduce the overall exposure to toxic byproducts. Third, the understanding of formation pathways should be employed to devise methods of applying disinfectants that minimize byproduct formation while accomplishing pathogen reduction goals. Fourth, the well-characterized nature of the monomers constituting the biopolymers that likely dominate the organic nitrogen precursor pool should be exploited to predict the formation of byproducts likely to form at high yields.

  13. Disinfection of swine wastewater using chlorine, ultraviolet light and ozone.

    PubMed

    Macauley, John J; Qiang, Zhimin; Adams, Craig D; Surampalli, Rao; Mormile, Melanie R

    2006-06-01

    Veterinary antibiotics are widely used at concentrated animal feeding operations (CAFOs) to prevent disease and promote growth of livestock. However, the majority of antibiotics are excreted from animals in urine, feces, and manure. Consequently, the lagoons used to store these wastes can act as reservoirs of antibiotics and antibiotic-resistant bacteria. There is currently no regulation or control of these systems to prevent the spread of these bacteria and their genes for antibiotic resistance into other environments. This study was conducted to determine the disinfection potential of chlorine, ultraviolet light and ozone against swine lagoon bacteria. Results indicate that a chlorine dose of 30 mg/L could achieve a 2.2-3.4 log bacteria reduction in lagoon samples. However, increasing the dose of chlorine did not significantly enhance the disinfection activity due to the presence of chlorine-resistant bacteria. The chlorine resistant bacteria were identified to be closely related to Bacillus subtilis and Bacillus licheniformis. A significant percentage of lagoon bacteria were not susceptible to the four selected antibiotics: chlortetracycline, lincomycin, sulfamethazine and tetracycline (TET). However, the presence of both chlorine and TET could inactivate all bacteria in one lagoon sample. The disinfection potential of UV irradiation and ozone was also examined. Ultraviolet light was an effective bacterial disinfectant, but was unlikely to be economically viable due to its high energy requirements. At an ozone dose of 100 mg/L, the bacteria inactivation efficiency could reach 3.3-3.9 log.

  14. Sequential and Simultaneous Applications of UV and Chlorine for Adenovirus Inactivation.

    PubMed

    Rattanakul, Surapong; Oguma, Kumiko; Takizawa, Satoshi

    2015-09-01

    Adenoviruses are water-borne human pathogens with high resistance to UV disinfection. Combination of UV treatment and chlorination could be an effective approach to deal with adenoviruses. In this study, human adenovirus 5 (HAdV-5) was challenged in a bench-scale experiment by separate applications of UV or chlorine and by combined applications of UV and chlorine in either a sequential or simultaneous manner. The treated samples were then propagated in human lung carcinoma epithelial cells to quantify the log inactivation of HAdV-5. When the processes were separate, a fluence of 100 mJ/cm(2) and a CT value of 0.02 mg min/L were required to achieve 2 log inactivation of HAdV-5 by UV disinfection and chlorination, respectively. Interestingly, synergistic effects on the HAdV-5 inactivation rates were found in the sequential process of chlorine followed by UV (Cl2-UV) (p < 0.05, ANCOVA) in comparison to the separate processes or the simultaneous application of UV/Cl2. This implies that a pretreatment with chlorine may increase the sensitivity of the virus to the subsequent UV disinfection. In conclusion, this study suggests that the combined application of UV and chlorine could be an effective measure against adenoviruses as a multi-barrier approach in water disinfection.

  15. Stery-hand: A new device to support hand disinfection.

    PubMed

    Szilagyi, Laszlo; Lehotsky, Akos; Nagy, Melinda; Haidegger, Tamas; Benyo, Balazs; Benyo, Zoltan

    2010-01-01

    Incomplete disinfection can cause serious complications in surgical care. The teaching of effective hand washing is crucial in modern medical training. To support the objective evaluation of hand disinfection, we developed a compact, mobile device, relying on digital imaging and image processing. The hardware consists of a metal case with matte black interior, ultra-violet lighting and a digital camera. Image segmentation and clustering are performed on a regular notebook. The hand washing procedures performed with a soap mixed with UV-reflective powder. This results the skin showing bright under UV light only on the treated (sterile) surfaces. When the surgeon inserts its hands into the box, the camera placed on the top takes an image of the hand for evaluation. The software performs the segmentation and clustering automatically. First, the hand contour is determined from the green intensity channel of the recorded RGB image. Then, the pixels of the green channel belonging to the hand are partitioned to three clusters using a quick, histogram based fuzzy c-means algorithm. The optimal threshold between the intensities of clean and dirty areas is extracted using these clusters, while the final approximated percentage of the clean area is computed using a weighting formula. The main advantage of our device is the ability to obtain objective and comparable result on the quality of hand disinfection. It may find its best use in the clinical education and training. PMID:21096021

  16. Minimization of the formation of disinfection by-products.

    PubMed

    Badawy, Mohamed I; Gad-Allah, Tarek A; Ali, Mohamed E M; Yoon, Yeoman

    2012-09-01

    The drinking water industry is required to minimize DBPs levels while ensuring adequate disinfection. In this study, efficient and appropriate treatment scheme for the reduction of disinfection by-product (DBPs) formation in drinking water containing natural organic matter has been established. This was carried out by the investigation of different treatment schemes consisting of enhanced coagulation, sedimentation, disinfection by using chlorine dioxide/ozone, filtration by sand filter, or granular activated carbon (GAC). Bench scale treatment schemes were applied on actual samples from different selected sites to identify the best conditions for the treatment of water. Samples were collected from effluent of each step in the treatment train in order to analyze pH, UV absorbance at 254 nm (UVA(254)), specific UV absorbance at 254 nm (SUVA(254)), dissolved organic carbon (DOC), haloacetic acids (HAAs) and trihalomethanes (THMs). The obtained results indicated that using pre-ozonation/enhanced coagulation/activated carbon filtration treatment train appears to be the most effective method for reducing DBPs precursors in drinking water treatment.

  17. Automated particulate sampler field test model operations guide

    SciTech Connect

    Bowyer, S.M.; Miley, H.S.

    1996-10-01

    The Automated Particulate Sampler Field Test Model Operations Guide is a collection of documents which provides a complete picture of the Automated Particulate Sampler (APS) and the Field Test in which it was evaluated. The Pacific Northwest National Laboratory (PNNL) Automated Particulate Sampler was developed for the purpose of radionuclide particulate monitoring for use under the Comprehensive Test Ban Treaty (CTBT). Its design was directed by anticipated requirements of small size, low power consumption, low noise level, fully automatic operation, and most predominantly the sensitivity requirements of the Conference on Disarmament Working Paper 224 (CDWP224). This guide is intended to serve as both a reference document for the APS and to provide detailed instructions on how to operate the sampler. This document provides a complete description of the APS Field Test Model and all the activity related to its evaluation and progression.

  18. Effects of UV intensity and water turbidity on microbial indicator inactivation.

    PubMed

    Liu, Wen-jun; Zhang, Yong-ji

    2006-01-01

    The effects of UV intensity and turbidity on selected microbial indicator inactivation were investigated. Results showed that UV disinfection was effective in killing all the selected microbial indicators, the resistance order of the microorganisms was as follows: MS-2 coliphage > Bacillus subtilis > E. coli > Staphylococcus aureus and Candida albicans. UV intensity had influence on the inactivation of all the microorganisms, high UV disinfection efficency was obtained with higher UV intensity. Turbidity had impact on the bacteria inactivation rate, but there was no evidence that turbidity had any negative contribution to MS-2 coliphage. Under the same UV dosage, higher UV intensity could overcome the negative influence of turbidity on UV performance, enhanced microorganism inactivation effect in turbidity water. PMID:17078540

  19. Field test of fiber optic ocean bottom seismograph

    NASA Astrophysics Data System (ADS)

    Zhang, Wentao; Wang, Zhaogang; Huang, Wenzhu; Li, Li; Liu, Wenyi; Luo, Yingbo; Li, Fang

    2016-05-01

    In this paper we report the field test of fiber optic ocean bottom seismograph (OOBS) which can be used in the active source seismic research. There are three fiber laser accelerometers (FLAs) and one fiber laser hydrophone (FLH), which is wavelength division multiplexed, in the OOBS. The interrogation system is put on shore and is connected with the OOBS with optical fiber cable. The field test of using an air gun is carried out under water with a depth of 30 m. The results show that the OOBS has similar performance as conventional electric OBS.

  20. Field test of microbend fiber sensor for hospital use

    NASA Astrophysics Data System (ADS)

    Chen, Zhihao; Lau, Doreen; Teo, Ju Teng; Ng, Soon Huat; Yang, Xiufeng; Kei, Pin Lin

    2014-05-01

    In this paper, we report a field test of a microbend fiber sensor for simultaneous measurement of breathing rate, breathing pattern, Ballistocardiogram and heart rate during magnetic resonance imaging (MRI). Comparative experiments conducted between our sensor and commercial physiologic device on a healthy male subject showed an accuracy of +/-2bpm for simultaneous measurement of both breathing rate and heart rate. Our preliminary field test on simultaneous measurement of breathing rate and heart rate in a clinical trial conducted on 11 healthy subjects in the 3.0 Tesla MRI environment showed very good agreement compared with measurements obtained from conventional MRcompatible devices.

  1. Formation of N-nitrosamines from eleven disinfection treatments of seven different surface waters.

    PubMed

    Zhao, Yuan-Yuan; Boyd, Jessica M; Woodbeck, Matthew; Andrews, Robert C; Qin, Feng; Hrudey, Steve E; Li, Xing-Fang

    2008-07-01

    Formation of nine N-nitrosamines has been investigated when seven different source waters representing various qualities were each treated with eleven bench-scale disinfection processes, without addition of nitrosamine precursors. These disinfection treatments included chlorine (OCl-), chloramine (NH2Cl), chlorine dioxide (ClO2), ozone (O3), ultraviolet (UV), advanced oxidation processes (AOP), and combinations. The total organic carbon (TOC) of the seven source waters ranged from 2 to 24 mg x L(-1). The disinfected water samples and the untreated source waters were analyzed for nine nitrosamines using a solid phase extraction and liquid chromatography-tandem mass spectrometry method. Prior to any treatment, N-nitrosodimethylamine (NDMA) was detected ranging from 0 to 53 ng x L(-1) in six of the seven source waters, and its concentrations increased in the disinfected water samples (0-118 ng x L(-1)). N-nitrosodiethylamine (NDEA), N-nitrosomorpholine (NMor), and N-nitrosodiphenylamine (NDPhA) were also identified in some of the disinfected water samples. NDPhA (0.2-0.6 ng x L(-1)) was formed after disinfection with OCl-, NH2Cl, O3, and MPUV/OCl-. NMEA was produced with OCl- and MPUV/OCl-, and NMor formation was associated with O3. In addition, UVtreatment alone degraded NDMA; however, UV/ OCl- and AOP/OCl- treatments produced higher amounts of NDMA compared to UV and AOP alone, respectively. These results suggest that UV degradation or AOP oxidation treatment may provide a source of NDMA precursors. This study demonstrates that environmental concentrations and mixtures of unknown nitrosamine precursors in source waters can form NDMA and other nitrosamines.

  2. Applicability of UV resistant Bacillus pumilus endospores as a human adenovirus surrogate for evaluating the effectiveness of virus inactivation in low-pressure UV treatment systems

    EPA Science Inventory

    Recent studies have demonstrated the potential to use Bacillus pumilus endospores as a surrogate of human adenovirus (HAdV) in UV disinfection studies. The use of endospores has been limited by observations of batch-to-batch variation in UV sensitivity. This study reports on a pr...

  3. Ultraviolet disinfection of water for small water supplies

    NASA Astrophysics Data System (ADS)

    Carlson, D. A.; Seabloom, R. W.; Dewalle, F. B.; Wetzler, T. F.; Engeset, J.

    1985-07-01

    In the study ultraviolet radiation was considered as an alternative means of disinfection of small drinking water supplies. A major impetus for the study was the large increase in waterborne disease episodes in the United States whose etiologic agent, Giardia lamblia, was found to be highly resistant to conventional chlorination. While the germicidal effect of sunlight has long been known, it has been found that artificial UV radiation with a wavelength of 253.7 nm, can be produced by low pressure mercury vapor lamps. The inactivation of microorganisms by UV radiation is based upon photochemical reactions in DNA which result in errors in the coding system. Inactivation of microorganisms due to exposure to UV is proportional to the intensity multiplied by the time of exposure.

  4. Analyzing Educational Testing Service Graduate Major Field Test Results

    ERIC Educational Resources Information Center

    Thornton, Barry; Arbogast, Gordon

    2012-01-01

    The Educational Testing Service (ETS) created the Graduate Major Field Test in Business (GMFT-B) for MBA students. This test is administered to all MBA classes at Jacksonville University for the purpose of measuring student academic achievement and growth, as well as to assess educational outcomes. The test is given in the capstone course,…

  5. Field Testing Vocational Education Metric Modules. Final Report.

    ERIC Educational Resources Information Center

    Oldsen, Carl F.

    A project was conducted for the following purposes: (1) to develop a workshop training package to prepare vocational education teachers to use vocational subject-specific modules; (2) to train those teachers to use the workshop package; (3) to conduct field tests of the metric modules with experimental and control groups; (4) to analyze, describe,…

  6. Results of field tests of a transportable calorimeter assay system

    SciTech Connect

    Rakel, D.A.; Lemming, J.F.; Rodenburg, W.W.; Duff, M.F.; Jarvis, J.Y.

    1981-01-01

    A transportable calorimetric assay system, developed for use by US Department of Energy inspectors, is described. The results of field tests at three DOE sites are presented. The samples measured in these tests represent a variety of forms (ash, oxide, metal buttons), isotopic composition, and total plutonium content.

  7. Evaluation Report: Early Childhood Education Program, 1969 Field Test.

    ERIC Educational Resources Information Center

    Appalachia Educational Lab., Charleston, WV.

    Reported are findings from the first year's field test of the home-oriented Appalachia Educational Laboratory (AEL) Early Childhood Education Program for 3-, 4-, and 5-year-olds. The program consists of a 30-minute daily television lesson, a weekly home visit by a paraprofessional, and group instruction once a week in a mobile classroom. The…

  8. Differential Gender Performance on the Major Field Test-Business

    ERIC Educational Resources Information Center

    Bielinska-Kwapisz, Agnieszka; Brown, F. William

    2013-01-01

    The Major Field Test in Business (MFT-B), a standardized assessment test of business knowledge among undergraduate business seniors, is widely used to measure student achievement. Many previous studies analyzing scores on the MFT-B report gender differences on the exam even after controlling for student's aptitude, general intellectual…

  9. Field tests of transgenic barley lines in North Dakota

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Testing transgenic barley lines for FHB in the greenhouse does not necessarily give the same results as field tests. The objective of this project was to test 18 transgenic lines in replicated trials in an inoculated FHB nursery. Several programs have developed barley lines expressing anti-fungal a...

  10. 29. PLAN OF THE ARVFS FIELD TEST FACILITY SHOWING BUNKER, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. PLAN OF THE ARVFS FIELD TEST FACILITY SHOWING BUNKER, CABLE CHASE, SHIELDING TANK AND FRAME ASSEMBLY. F.C. TORKELSON DRAWING NUMBER 842-ARVFS-701-1. INEL INDEX CODE NUMBER: 075 0701 851 151970. - Idaho National Engineering Laboratory, Advanced Reentry Vehicle Fusing System, Scoville, Butte County, ID

  11. 30. ELEVATION OF ARVFS FIELD TEST FACILITY SHOWING VIEW OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. ELEVATION OF ARVFS FIELD TEST FACILITY SHOWING VIEW OF SOUTH SIDE OF FACILITY, INCLUDING BUNKER, CABLE CHASE, SHIELDING TANK, AND FRAME ASSEMBLY. F.C. TORKELSON DRAWING NUMBER 842-ARVFS-701-2. INEL INDEX CODE NUMBER: 075 0701 851 151971. - Idaho National Engineering Laboratory, Advanced Reentry Vehicle Fusing System, Scoville, Butte County, ID

  12. 40 CFR 35.2262 - Funding of field testing.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Funding of field testing. 35.2262 Section 35.2262 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2262 Funding of...

  13. 40 CFR 35.2262 - Funding of field testing.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Funding of field testing. 35.2262 Section 35.2262 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2262 Funding of...

  14. 40 CFR 35.2262 - Funding of field testing.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Funding of field testing. 35.2262 Section 35.2262 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2262 Funding of...

  15. Documenting and Explaining Major Field Test Results among Undergraduate Students

    ERIC Educational Resources Information Center

    Contreras, Salvador; Badua, Frank; Chen, Jiun Shiu; Adrian, Mitchell

    2011-01-01

    The authors investigated the results of the Educational Testing Service Major Field Test (ETS-MFT) administered to business majors at a U.S. state university. Longitudinal trends and cross-sectional differences are documented, including significant performance differences among students of different majors. Findings suggest that a cohort affect…

  16. READ: Field Test of an Educational Approach to Reading Disability.

    ERIC Educational Resources Information Center

    Morsink, Catherine

    This investigation describes a field test of the materials entitled "Reading: An Educational Approach to Disability" (READ), which were developed to aid disabled readers in the beginning stages of learning to decode English print. The subjects were 15 Title I reading teachers working in small groups with 183 second-grade children. The questions of…

  17. Laboratory or field tests for evaluating firefighters' work capacity?

    PubMed

    Lindberg, Ann-Sofie; Oksa, Juha; Malm, Christer

    2014-01-01

    Muscle strength is important for firefighters work capacity. Laboratory tests used for measurements of muscle strength, however, are complicated, expensive and time consuming. The aims of the present study were to investigate correlations between physical capacity within commonly occurring and physically demanding firefighting work tasks and both laboratory and field tests in full time (N = 8) and part-time (N = 10) male firefighters and civilian men (N = 8) and women (N = 12), and also to give recommendations as to which field tests might be useful for evaluating firefighters' physical work capacity. Laboratory tests of isokinetic maximal (IM) and endurance (IE) muscle power and dynamic balance, field tests including maximal and endurance muscle performance, and simulated firefighting work tasks were performed. Correlations with work capacity were analyzed with Spearman's rank correlation coefficient (rs). The highest significant (p<0.01) correlations with laboratory and field tests were for Cutting: IE trunk extension (rs = 0.72) and maximal hand grip strength (rs = 0.67), for Stairs: IE shoulder flexion (rs = -0.81) and barbell shoulder press (rs = -0.77), for Pulling: IE shoulder extension (rs = -0.82) and bench press (rs = -0.85), for Demolition: IE knee extension (rs = 0.75) and bench press (rs = 0.83), for Rescue: IE shoulder flexion (rs = -0.83) and bench press (rs = -0.82), and for the Terrain work task: IE trunk flexion (rs = -0.58) and upright barbell row (rs = -0.70). In conclusion, field tests may be used instead of laboratory tests. Maximal hand grip strength, bench press, chin ups, dips, upright barbell row, standing broad jump, and barbell shoulder press were strongly correlated (rs≥0.7) with work capacity and are therefore recommended for evaluating firefighters work capacity. PMID:24614596

  18. Health effects of drinking water disinfectants and disinfection by-products

    SciTech Connect

    Condie, L.W.; Bercz, J.P.

    1986-01-01

    This paper summarizes toxicological studies conducted with drinking water disinfectants. Toxicological effects, which are associated with the disinfectants themselves as well as with the by-products formed when disinfectants react with organic material present in water, are considered. The health impact of chemical reactions occurring between residual disinfectants and nutrients in the gastrointestinal tract is also discussed. 40 references, 5 tables.

  19. 40 CFR 141.54 - Maximum residual disinfectant level goals for disinfectants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum residual disinfectant level goals for disinfectants. 141.54 Section 141.54 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.54 Maximum residual disinfectant level...

  20. 40 CFR 141.54 - Maximum residual disinfectant level goals for disinfectants.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Maximum residual disinfectant level goals for disinfectants. 141.54 Section 141.54 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.54 Maximum residual disinfectant level...

  1. 40 CFR 141.54 - Maximum residual disinfectant level goals for disinfectants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Maximum residual disinfectant level goals for disinfectants. 141.54 Section 141.54 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.54 Maximum residual disinfectant level...

  2. 40 CFR 141.54 - Maximum residual disinfectant level goals for disinfectants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Maximum residual disinfectant level goals for disinfectants. 141.54 Section 141.54 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.54 Maximum residual disinfectant level...

  3. 40 CFR 141.54 - Maximum residual disinfectant level goals for disinfectants.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Maximum residual disinfectant level goals for disinfectants. 141.54 Section 141.54 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.54 Maximum residual disinfectant level...

  4. A pulsed light system for the disinfection of flow through water in the presence of inorganic contaminants.

    PubMed

    Garvey, Mary; Rowan, Neil

    2015-06-01

    The use of ultraviolet (UV) light for water disinfection has become increasingly popular due to on-going issues with drinking water and public health. Pulsed UV light has proved to be an effective form of inactivating a range of pathogens including parasite species. However, there are limited data available on the use of pulsed UV light for the disinfection of flowing water in the absence or presence of inorganic contaminants commonly found in water sources. Here, we report on the inactivation of test species including Bacillus endospores following pulsed UV treatment as a flow through system. Significant levels of inactivation were obtained for both retention times tested. The presence of inorganic contaminants iron and/or manganese did affect the rate of disinfection, predominantly resulting in an increase in the levels of inactivation at certain UV doses. The findings of this study suggest that pulsed UV light may provide a method of water disinfection as it successfully inactivated bacterial cells and bacterial endospores in the absence and presence of inorganic contaminants.

  5. Disinfection potential of ozone, ultraviolet-C and their combination in wash water for the fresh-cut vegetable industry.

    PubMed

    Selma, María V; Allende, Ana; López-Gálvez, Francisco; Conesa, María A; Gil, María I

    2008-09-01

    The purpose of this research was to investigate the disinfection efficacy of ozone (O(3)) and UV-C illumination (UV), and their combination (O(3)-UV) for reducing microbial flora of fresh-cut onion, escarole, carrot, and spinach wash waters collected from the industry. Furthermore, the influence of water physicochemical parameters on the decontamination efficacy and the effect of these technologies on physicochemical quality of wash water were analyzed. O(3), UV, and O(3)-UV were effective disinfection treatments on vegetable wash water, with a maximum microbial reduction of 6.6 log CFU mL(-1) after 60 min treatment with O(3)-UV. However, maximum total microbial reductions achieved by UV and O(3) treatments after 60 min were 4.0 and 5.9 log CFU mL(-1), lower than by O(3)-UV treatment. Furthermore, turbidity of wash water was reduced significantly by O(3) and O(3)-UV treatments, while UV treatment did not affect the physicochemical quality of the water. Conclusions derived from this study illustrate that O(3) and O(3)-UV are alternatives to other sanitizers used in the fresh-cut washing processes. The use of these technologies would allow less frequent changing of spent water and the use of much lower sanitizer doses. Nevertheless, in specific applications such as carrot wash water, where levels of undesirable microbial and chemical constituents are lower than other vegetable wash water, UV treatment could be an appropriate treatment considering cost-effectiveness criteria.

  6. Can pulsed xenon ultraviolet light systems disinfect aerobic bacteria in the absence of manual disinfection?

    PubMed

    Jinadatha, Chetan; Villamaria, Frank C; Ganachari-Mallappa, Nagaraja; Brown, Donna S; Liao, I-Chia; Stock, Eileen M; Copeland, Laurel A; Zeber, John E

    2015-04-01

    Whereas pulsed xenon-based ultraviolet light no-touch disinfection systems are being increasingly used for room disinfection after patient discharge with manual cleaning, their effectiveness in the absence of manual disinfection has not been previously evaluated. Our study indicates that pulsed xenon-based ultraviolet light systems effectively reduce aerobic bacteria in the absence of manual disinfection. These data are important for hospitals planning to adopt this technology as adjunct to routine manual disinfection.

  7. Influence of wastewater disinfection on densities of culturable fecal indicator bacteria and genetic markers.

    PubMed

    Chern, Eunice C; Brenner, Kristen; Wymer, Larry; Haugland, Richard A

    2014-09-01

    The US Environmental Protection Agency has proposed the use of quantitative polymerase chain reaction (qPCR) as a rapid alternative analytical method for monitoring recreational water quality at beaches. For qPCR to be considered for other Clean Water Act purposes, such as inclusion in discharge permits and use in Total Maximum Daily Load calculations, it is necessary to understand how qPCR detectable genetic markers are influenced by wastewater disinfection. This study investigated genetic markers for Escherichia coli, Enterococcus, Clostridium spp., Bacteroides, total Bacteroidales, as well as the human-associated Bacteroides markers, HF183 and HumM2, to determine which, if any, were influenced by disinfection (chlorination or ultraviolet light) of effluents from secondary wastewater treatment in different seasons. The effects of disinfection on culturable enterococci, E. coli, Bacteroides, and C. perfringens were also compared to their associated genetic markers. Disinfection of secondary treatment effluents significantly reduced culturable fecal indicator bacteria (FIB) but not genetic marker densities. No significant differences were observed in the responses of FIB culture and genetic marker densities to type of disinfection (chlorination vs UV) or season. Results of this study provide evidence that qPCR may not be suitable for monitoring efficacy of wastewater disinfection on the inactivation of bacterial pathogens. PMID:25252344

  8. Influence of wastewater disinfection on densities of culturable fecal indicator bacteria and genetic markers.

    PubMed

    Chern, Eunice C; Brenner, Kristen; Wymer, Larry; Haugland, Richard A

    2014-09-01

    The US Environmental Protection Agency has proposed the use of quantitative polymerase chain reaction (qPCR) as a rapid alternative analytical method for monitoring recreational water quality at beaches. For qPCR to be considered for other Clean Water Act purposes, such as inclusion in discharge permits and use in Total Maximum Daily Load calculations, it is necessary to understand how qPCR detectable genetic markers are influenced by wastewater disinfection. This study investigated genetic markers for Escherichia coli, Enterococcus, Clostridium spp., Bacteroides, total Bacteroidales, as well as the human-associated Bacteroides markers, HF183 and HumM2, to determine which, if any, were influenced by disinfection (chlorination or ultraviolet light) of effluents from secondary wastewater treatment in different seasons. The effects of disinfection on culturable enterococci, E. coli, Bacteroides, and C. perfringens were also compared to their associated genetic markers. Disinfection of secondary treatment effluents significantly reduced culturable fecal indicator bacteria (FIB) but not genetic marker densities. No significant differences were observed in the responses of FIB culture and genetic marker densities to type of disinfection (chlorination vs UV) or season. Results of this study provide evidence that qPCR may not be suitable for monitoring efficacy of wastewater disinfection on the inactivation of bacterial pathogens.

  9. Disinfection of Human Teeth for Educational Purposes.

    ERIC Educational Resources Information Center

    Tate, William H.; White, Robert S.

    1991-01-01

    A study investigated the efficacy of glutaraldehyde and several other disinfectants for disinfecting teeth to be used for teaching and research, as an alternative to autoclaving for teeth with amalgam restorations. Results indicate that formalin was the only disinfectant that penetrated tooth pulp chambers in effective antimicrobial…

  10. [Drinking water decontamination with isolative sorbent disinfectants].

    PubMed

    Krasnov, M S

    2004-01-01

    Drinking water can be decontaminated with the use of isolative sorbent disinfectants. Consideration of the effectiveness of water disinfectants and the sorptive power of porous materials against bacteria and viruses attested to the favour of iodine and silver-containing disinfectants and their compositions on porous aggressive carriers to be employed in extreme conditions such as on board crewed space vehicles.

  11. Prototype Engineered Barrier System Field Tests; Progress report

    SciTech Connect

    Ramirez, A.L.; Beatty, J.; Buscheck, T.A.; Carlson, R.; Daily, W.; LaTorre, V.R.; Lee, K.; Lin, Wunan; Mao, Nai-hsien; Nitao, J.J.; Towse, D.; Ueng, Tzou-Shin; Watwood, D.; Wilder, D.

    1989-07-26

    This paper presents selected preliminary results obtained during the first 54 days of the Prototype Engineered Barrier System Field Tests (PEBSFT) that are being performed in G-Tunnel within the Nevada Test Site. The test described is a precursor to the Engineered Barrier Systems Field Tests (EBSFT). The EBSFT will consist of in situ tests of the geohydrologic and geochemical environment in the near field (within a few meters) of heaters emplaced in welded tuff to simulate the thermal effects of waste packages. The PEBSFTs are being conducted to evaluate the applicability of measurement techniques, numerical models, and procedures for future investigations that will be conducted in the Exploratory Shaft Facilities of the Yucca Mountain Project (YMP). The paper discusses the evolution of hydrothermal behavior during the prototype test, including rock temperatures, changes in rock moisture content, air permeability of fractures, gas pressures, and rock mass gas-phase humidity. 10 refs., 12 figs.

  12. Review of water disinfection techniques

    NASA Technical Reports Server (NTRS)

    Colombo, Gerald V.; Sauer, Richard L.

    1987-01-01

    Throughout the history of manned space flight the supply of potable water to the astronauts has presented unique problems. Of particular concern has been the microbiological quality of the potable water. This has required the development of both preflight water system servicing procedures to disinfect the systems and inflight disinfectant addition and monitoring devices to ensure continuing microbiological control. The disinfectants successfully used to date have been aqueous chlorine or iodine. Because of special system limitations the use of iodine has been the most successful for inflight use and promises to be the agent most likely to be used in the future. Future spacecraft potable, hygiene, and experiment water systems will utilize recycled water. This will present special problems for water quality control. NASA is currently conducting research and development to solve these problems.

  13. Development of a field test for upper-body power.

    PubMed

    Shim, A L; Bailey, M L; Westings, S H

    2001-05-01

    The purpose of this study was to develop a field test capable of measuring upper-body power through the use of a common weight-training apparatus, a Smith machine (SM), set up for bench press (BP) movement. A small, battery-operated digital timing device was designed and constructed to allow a precise calculation of power (in conjunction with measures of distance and force) for this specific movement, which involved an explosive press from the chest to a position just short of full arm extension. In pilot work, 1 repetition maximums (1RM) were determined on the SM BP for 3 male subjects, and by subsequently testing power on the same subjects at varying resistances, an average relative percentage of the 1RM-producing peak power values was found by power curve analysis for test standardization. Reliability was assessed (using 11 men) by SM power measurements taken over 3 days on the SM fitted with the timer. An intraclass R (0.998) indicated a high correlation between the 3 separate field-test trials. Finally, 8 male subjects were used to compare SM scores with a criterion measure, the Linea Isokinetic BP station (Loredan Biomedical, Inc., Sacramento CA). A Pearson product moment coefficient found a high correlation between the field test (SM) and Linea power scores (r = 0.987). A 2-tailed dependent t-test between the field and criterion scores was not significant, suggesting that no consistent error variable was present. It can be concluded that this is a valid field test of power for this movement. PMID:11710404

  14. U.S. field testing programs and results

    SciTech Connect

    Wicks, G.G.

    2000-06-09

    The United States has been active in four major international in-situ or field testing programs over the past two decades, involving the burial of simulated high-level waste forms and package components. These programs are designed to supplement laboratory testing studies in order to obtain the most complete and realistic picture possible of waste glass behavior under realistic repository-relevant conditions.

  15. The Center-TRACON Automation System: Simulation and field testing

    NASA Technical Reports Server (NTRS)

    Denery, Dallas G.; Erzberger, Heinz

    1995-01-01

    A new concept for air traffic management in the terminal area, implemented as the Center-TRACON Automation System, has been under development at NASA Ames in a cooperative program with the FAA since 1991. The development has been strongly influenced by concurrent simulation and field site evaluations. The role of simulation and field activities in the development process will be discussed. Results of recent simulation and field tests will be presented.

  16. Lidar Tracking of Multiple Fluorescent Tracers: Method and Field Test

    NASA Technical Reports Server (NTRS)

    Eberhard, Wynn L.; Willis, Ron J.

    1992-01-01

    Past research and applications have demonstrated the advantages and usefulness of lidar detection of a single fluorescent tracer to track air motions. Earlier researchers performed an analytical study that showed good potential for lidar discrimination and tracking of two or three different fluorescent tracers at the same time. The present paper summarizes the multiple fluorescent tracer method, discusses its expected advantages and problems, and describes our field test of this new technique.

  17. On-site cell field test support program

    NASA Astrophysics Data System (ADS)

    Staniunas, J. W.; Merten, G. P.

    1982-09-01

    Utility sites for data monitoring were reviewed and selected. Each of these sites will be instrumented and its energy requirements monitored and analyzed for one year prior to the selection of 40 Kilowatt fuel cell field test sites. Analyses in support of the selection of sites for instrumentation shows that many building sectors offered considerable market potential. These sectors include nursing home, health club, restaurant, industrial, hotel/motel and apartment.

  18. Determining UV Inactivation of Toxoplasma gondii Oocysts by Using Cell Culture and a Mouse Bioassay

    EPA Science Inventory

    The effect of UV exposure on Toxoplasma gondii oocysts has not been completely defined for use in water disinfection. This study evaluated UV irradiated oocysts by three assays: a SCID mouse bioassay, an in vitro T. gondii oocyst plaque assay (TOP-assay), and a quantitative reve...

  19. New disinfection and sterilization methods.

    PubMed Central

    Rutala, W. A.; Weber, D. J.

    2001-01-01

    New disinfection methods include a persistent antimicrobial coating that can be applied to inanimate and animate objects (Surfacine), a high-level disinfectant with reduced exposure time (ortho-phthalaldehyde), and an antimicrobial agent that can be applied to animate and inanimate objects (superoxidized water). New sterilization methods include a chemical sterilization process for endoscopes that integrates cleaning (Endoclens), a rapid (4-hour) readout biological indicator for ethylene oxide sterilization (Attest), and a hydrogen peroxide plasma sterilizer that has a shorter cycle time and improved efficacy (Sterrad 50). PMID:11294738

  20. Microbial selectivity of UV treatment on antibiotic-resistant heterotrophic bacteria in secondary effluents of a municipal wastewater treatment plant.

    PubMed

    Guo, Mei-Ting; Yuan, Qing-Bin; Yang, Jian

    2013-10-15

    Little is known about the microbial selectivity of UV treatment for antibiotic resistant bacteria, and the results of limited studies are conflicting. To understand the effect of UV disinfection on antibiotic resistant bacteria, both total heterotrophic bacteria and antibiotic resistant bacteria (including cephalexin-, ciprofloxacin-, erythromycin-, gentamicin-, vancomycin-, sulfadiazine-, rifampicin-, tetracycline- and chloramphenicol-resistant bacteria) were examined in secondary effluent samples from a municipal wastewater treatment plant. Bacteria resistant to both erythromycin and tetracycline were chosen as the representative of multiple-antibiotic-resistant bacteria and their characteristics after UV treatment were also investigated. UV disinfection results in effective inactivation for total heterotrophic bacteria, as well as all antibiotic resistant bacteria. After UV treatment at a fluence of 5 mJ/cm(2), the log reductions of nine types of antibiotic resistant bacteria varied from 1.0 ± 0.1 to 2.4 ± 0.1. Bacteria resistant to both erythromycin and tetracycline had a similar fluence response as did total heterotrophic bacteria. The findings suggest that UV disinfection could eliminate antibiotic resistance in wastewater treatment effluents and thus ensure public health security. Our experimental results indicated that UV disinfection led to enrichment of bacteria with resistance to sulfadiazine, vancomycin, rifampicin, tetracycline and chloramphenicol, while the proportions of cephalexin-, erythromycin-, gentamicin- and ciprofloxacin-resistant bacteria in the wastewater decreased. This reveals the microbial selectivity of UV disinfection for antibiotic resistant bacteria. PMID:24001605

  1. Cell culture-Taqman PCR assay for evaluation of Cryptosporidium parvum disinfection.

    PubMed

    Keegan, Alexandra R; Fanok, Stella; Monis, Paul T; Saint, Christopher P

    2003-05-01

    Cryptosporidium parvum represents a challenge to the water industry and a threat to public health. In this study, we developed a cell culture-quantitative PCR assay to evaluate the inactivation of C. parvum with disinfectants. The assay was validated by using a range of disinfectants in common use in the water industry, including low-pressure UV light (LP-UV), ozone, mixed oxidants (MIOX), and chlorine. The assay was demonstrated to be reliable and sensitive, with a lower detection limit of a single infectious oocyst. Effective oocyst inactivation was achieved (>2 log(10) units) with LP-UV (20 mJ/cm(2)) or 2 mg of ozone/liter (for 10 min). MIOX and chlorine treatments of oocysts resulted in minimal effective disinfection, with <0.1 log(10) unit being inactivated. These results demonstrate the inability of MIOX to inactivate Cryptosporidium. The assay is a valuable tool for the evaluation of disinfection systems for drinking water and recycled water.

  2. Laboratory or Field Tests for Evaluating Firefighters' Work Capacity?

    PubMed Central

    Lindberg, Ann-Sofie; Oksa, Juha; Malm, Christer

    2014-01-01

    Muscle strength is important for firefighters work capacity. Laboratory tests used for measurements of muscle strength, however, are complicated, expensive and time consuming. The aims of the present study were to investigate correlations between physical capacity within commonly occurring and physically demanding firefighting work tasks and both laboratory and field tests in full time (N = 8) and part-time (N = 10) male firefighters and civilian men (N = 8) and women (N = 12), and also to give recommendations as to which field tests might be useful for evaluating firefighters' physical work capacity. Laboratory tests of isokinetic maximal (IM) and endurance (IE) muscle power and dynamic balance, field tests including maximal and endurance muscle performance, and simulated firefighting work tasks were performed. Correlations with work capacity were analyzed with Spearman's rank correlation coefficient (rs). The highest significant (p<0.01) correlations with laboratory and field tests were for Cutting: IE trunk extension (rs = 0.72) and maximal hand grip strength (rs = 0.67), for Stairs: IE shoulder flexion (rs = −0.81) and barbell shoulder press (rs = −0.77), for Pulling: IE shoulder extension (rs = −0.82) and bench press (rs = −0.85), for Demolition: IE knee extension (rs = 0.75) and bench press (rs = 0.83), for Rescue: IE shoulder flexion (rs = −0.83) and bench press (rs = −0.82), and for the Terrain work task: IE trunk flexion (rs = −0.58) and upright barbell row (rs = −0.70). In conclusion, field tests may be used instead of laboratory tests. Maximal hand grip strength, bench press, chin ups, dips, upright barbell row, standing broad jump, and barbell shoulder press were strongly correlated (rs≥0.7) with work capacity and are therefore recommended for evaluating firefighters work capacity. PMID:24614596

  3. EPIDEMIOLOGIC STUDIES OF DISINFECTANTS AND DISINFECTANT BY-PRODUCTS

    EPA Science Inventory

    This article provides a review of the epidemiologic evidence for human health effects that may be associated with the disinfection of drinking water. An epidemiologic study attempts to link human health effects with exposure to a specific agent (e.g., DBCM), agents (e.g., THMs or...

  4. Ultraviolet disinfection of antibiotic resistant bacteria and their antibiotic resistance genes in water and wastewater.

    PubMed

    McKinney, Chad W; Pruden, Amy

    2012-12-18

    Disinfection of wastewater treatment plant effluent may be an important barrier for limiting the spread of antibiotic-resistant bacteria (ARBs) and antibiotic resistance genes (ARGs). While ideally disinfection should destroy ARGs, to prevent horizontal gene transfer to downstream bacteria, little is known about the effect of conventional water disinfection technologies on ARGs. This study examined the potential of UV disinfection to damage four ARGs, mec(A), van(A), tet(A), and amp(C), both in extracellular form and present within a host ARBs: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VRE), Escherichia coli SMS-3-5, and Pseudomonas aeruginosa 01, respectively. An extended amplicon-length quantitative polymerase chain reaction assay was developed to enhance capture of ARG damage events and also to normalize to an equivalent length of target DNA (∼1000 bp) for comparison. It was found that the two Gram-positive ARBs (MRSA and VRE) were more resistant to UV disinfection than the two Gram-negative ARBs (E. coli and P. aeruginosa). The two Gram-positive organisms also possessed smaller total genome sizes, which could also have reduced their susceptibility to UV because of fewer potential pyrimidine dimer targets. An effect of cell type on damage to ARGs was only observed in VRE and P. aeruginosa, the latter potentially because of extracellular polymeric substances. In general, damage of ARGs required much greater UV doses (200-400 mJ/cm² for 3- to 4-log reduction) than ARB inactivation (10-20 mJ/cm² for 4- to 5-log reduction). The proportion of amplifiable ARGs following UV treatment exhibited a strong negative correlation with the number of adjacent thymines (Pearson r < -0.9; p < 0.0001). ARBs surviving UV treatment were negatively correlated with total genome size (Pearson r < -0.9; p < 0.0001) and adjacent cytosines (Pearson r < -0.88; p < 0.0001) but positively correlated with adjacent thymines (Pearson r

  5. Field testing of fugitive dust control techniques at a uranium mill tailings pile - 1982 Field Test, Gas Hills, Wyoming.

    SciTech Connect

    Elmore, M.R.; Hartley, J.N.

    1983-12-01

    A field test was conducted on a uranium tailings pile to evaluate the effectiveness of 15 chemical stabilizers for control of fugitive dust from uranium mill tailings. A tailings pile at the Federal American Partners (FAP) Uranium Mill, Gas Hills, Wyoming, was used for the field test. Preliminary laboratory tests using a wing tunnel were conducted to select the more promising stabilizers for field testing. Fourteen of the chemical stabilizers were applied with a field spray system pulled behind a tractor; one--Hydro Mulch--was applied with a hydroseeder. A portable weather station and data logger were installed to record the weather conditions at the test site. After 1 year of monitoring (including three site visits), all of the stabilizers have degraded to some degree; but those applied at the manufacturers' recommended rate are still somewhat effective in reducing fugitive emissions. The following synthetic polymer emulsions appear to be the more effective stabilizers: Wallpol 40-133 from Reichold Chemicals, SP-400 from Johnson and March Corporation, and CPB-12 from Wen Don Corporation. Installed costs for the test plots ranged from $8400 to $11,300/ha; this range results from differences in stabilizer costs. Large-scale stabilization costs of the test materials are expected to range from $680 to $3600/ha based on FAP experience. Evaluation of the chemical stabilizers will continue for approximately 1 year. 2 references, 33 figures, 22 tables.

  6. Experimental study on the disinfection efficiencies of a continuous-flow ultrasound/ultraviolet baffled reactor.

    PubMed

    Zhou, Xiaoqin; Guo, Hao; Li, Zifu; Zhao, Junyuan; Yun, Yupan

    2015-11-01

    A self-designed continuous-flow ultrasound/ultraviolet (US/UV) baffled reactor was tested in this work, and the disinfection efficiency of secondary effluent from a wastewater treatment plant (WWTP) was investigated in terms of the different locations of ultrasonic transducers inside the reactor under similar input power densities and specific energy consumptions. Results demonstrated that the two-stage simultaneous US/UV irradiation in both chambers 2 and 3 at a flow rate of 1200 L/h performed excellent disinfection efficiency. It achieved an average feacal coliforms concentration of 201±78 colony forming unit (CFU)/L in the effluent and an average of (4.24±0.26) log10 reduction. Thereafter, 8 days of continuous operation was performed under such a condition. A total of 31 samples were taken, and all the samples were analyzed in triplicate for feacal coliforms analysis. Experimental results showed that feacal coliforms concentrations remained at about 347±174 CFU/L under the selected optimum disinfection condition, even if the influent concentrations fluctuated from 3.97×10(5) to 3.57×10(6) CFU/L. This finding implied that all effluents of continuous-flow-baffled-reactor with simultaneous US/UV disinfection could meet the requirements of the discharge standard of pollutants for municipal WWTP (GB 18918-2002) Class 1-A (1000 CFU/L) with a specific energy consumption of 0.219 kWh/m(3). Therefore, the US/UV disinfection process has great potential for practical applications.

  7. Comparative effect of simulated solar light, UV, UV/H2O2 and photo-Fenton treatment (UV-Vis/H2O2/Fe2+,3+) in the Escherichia coli inactivation in artificial seawater.

    PubMed

    Rubio, D; Nebot, E; Casanueva, J F; Pulgarin, C

    2013-10-15

    Innovative disinfection technologies are being studied for seawater, seeking a viable alternative to chlorination. This study proposes the use of H2O2/UV254 and photo-Fenton as disinfection treatment in seawater. The irradiations were carried out using a sunlight simulator (Suntest) and a cylindrical UV reactor. The efficiency of the treatment was compared for Milli-Q water, Leman Lake water and artificial seawater. The presence of bicarbonates and organic matter was investigated in order to evaluate possible effects on the photo-Fenton disinfection treatment. The photo-Fenton treatment, employing 1 mg L(-1) Fe(2+) and 10 mg L(-1) of H2O2, led to the fastest bacterial inactivation kinetics. Using H2O2/UV254 high disinfection rates were obtained similar to those obtained with photo-Fenton under UV254 light. In Milli-Q water, the rate of inactivation for Escherichia coli was higher than in Leman Lake water and seawater due to the lack of inorganic ions affecting negatively bacteria inactivation. The presence of bicarbonate showed scavenging of the OH(•) radicals generated in the treatment of photo-Fenton and H2O2/UV254. Despite the negative effect of inorganic ions, especially HCO3(-), the disinfection treatments with AOPs in lake water and seawater improved significantly the disinfection compared to light alone (simulated sunlight and UV254). In the treatment of photo-Fenton with simulated sunlight, dissolved organic matter had a beneficial effect by increasing the rate of inactivation. This is associated with the formation of Fe(3+)-organo photosensitive complexes leading to the formation of ROS able to inactivate bacteria. This effect was not observed in the photo-Fenton with UV254. Growth of E. coli surviving in seawater was observed 24 and 48 h after treatment with UV light. However, growth of surviving bacteria was not detected after photo-Fenton with UV254 and H2O2/UV254 treatments. This study suggests H2O2/UV254 and photo-Fenton treatments for the

  8. Investigating synergism during sequential inactivation of MS-2 phage and Bacillus subtilis spores with UV/H2O2 followed by free chlorine.

    PubMed

    Cho, Min; Gandhi, Varun; Hwang, Tae-Mun; Lee, Sangho; Kim, Jae-Hong

    2011-01-01

    A sequential application of UV as a primary disinfectant with and without H(2)O(2) addition followed by free chlorine as secondary, residual disinfectant was performed to evaluate the synergistic inactivation of selected indicator microorganisms, MS-2 bacteriophage and Bacillus subtilis spores. No synergism was observed when the UV irradiation treatment was followed by free chlorine, i.e., the overall level of inactivation was the same as the sum of the inactivation levels achieved by each disinfection step. With the addition of H(2)O(2) in the primary UV disinfection step, however, enhanced microbial inactivation was observed. The synergism was observed in two folds manners: (1) additional inactivation achieved by hydroxyl radicals generated from the photolysis of H(2)O(2) in the primary UV disinfection step, and (2) damage to microorganisms in the primary step which facilitated the subsequent chlorine inactivation. Addition of H(2)O(2) in the primary disinfection step was also found to be beneficial for the degradation of selected model organic pollutants including bisphenol-A (endocrine disruptor), geosmin (taste and odor causing compound) and 2,4-D (herbicide). The results suggest that the efficiency of UV/free chlorine sequential disinfection processes, which are widely employed in drinking water treatment, could be significantly enhanced by adding H(2)O(2) in the primary step and hence converting the UV process to an advanced oxidation process.

  9. Recycled Water Poses Disinfectant Problem

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1973

    1973-01-01

    Discusses the possible health hazards resulting from released nucleic acid of inactivated viruses, chlorinated nonliving organic molecules, and overestimated reliability of waste treatment standards. Suggests the recycle system use a dual disinfectant such as chlorine and ozone in water treatment. (CC)

  10. Postoutbreak disinfection of mobile equipment.

    PubMed

    Alphin, R L; Ciaverelli, C D; Hougentogler, D P; Johnson, K J; Rankin, M K; Benson, E R

    2010-03-01

    Current control strategies for avian influenza virus, exotic Newcastle disease, and other highly contagious poultry diseases include surveillance, quarantine, depopulation, disposal, and decontamination. Skid steer loaders and other mobile equipment are extensively used during depopulation and disposal. Movement of contaminated equipment has been implicated in the spread of disease in previous outbreaks. One approach to equipment decontamination is to power wash the equipment, treat with a liquid disinfectant, change any removable filters, and let it sit idle for several days. In this project, multiple disinfectant strategies were individually evaluated for their effectiveness at inactivating Newcastle disease virus (NDV) on mechanical equipment seeded with the virus. A small gasoline engine was used to simulate typical mechanical equipment. A high titer of LaSota strain, NDV was applied and dried onto a series of metal coupons. The coupons were then placed on both interior and exterior surfaces of the engine. Liquid disinfectants that had been effective in the laboratory were not as effective at disinfecting the engine under field conditions. Indirect thermal fog showed a decrease in overall virus titer or strength. Direct thermal fog was more effective than liquid spray application or indirect thermal fog application. PMID:20521731

  11. Field tests for evaluating the aerobic work capacity of firefighters.

    PubMed

    Lindberg, Ann-Sofie; Oksa, Juha; Gavhed, Désirée; Malm, Christer

    2013-01-01

    Working as a firefighter is physically strenuous, and a high level of physical fitness increases a firefighter's ability to cope with the physical stress of their profession. Direct measurements of aerobic capacity, however, are often complicated, time consuming, and expensive. The first aim of the present study was to evaluate the correlations between direct (laboratory) and indirect (field) aerobic capacity tests with common and physically demanding firefighting tasks. The second aim was to give recommendations as to which field tests may be the most useful for evaluating firefighters' aerobic work capacity. A total of 38 subjects (26 men and 12 women) were included. Two aerobic capacity tests, six field tests, and seven firefighting tasks were performed. Lactate threshold and onset of blood lactate accumulation were found to be correlated to the performance of one work task (r(s) = -0.65 and -0.63, p<0.01, respectively). Absolute (mL · min(-1)) and relative (mL · kg(-1) · min(-1)) maximal aerobic capacity was correlated to all but one of the work tasks (r(s) = -0.79 to 0.55 and -0.74 to 0.47, p<0.01, respectively). Aerobic capacity is important for firefighters' work performance, and we have concluded that the time to row 500 m, the time to run 3000 m relative to body weight (s · kg(-1)), and the percent of maximal heart rate achieved during treadmill walking are the most valid field tests for evaluating a firefighter's aerobic work capacity. PMID:23844153

  12. Preliminary operational results of the industrial process heat field tests

    SciTech Connect

    Kutscher, C.; Davenport, R.

    1980-04-01

    There are currently six DOE-funded solar industrial process heat (IPH) field tests which have been operational for one year or longer. These are all low temperature first generation projects which supply heat at temperatures below 100/sup 0/C - three hot water and three hot air. During the 1979 calendar year, personnel from the Solar Energy Research Institute (SERI) visited all of these sites; the performance and cost results obtained for each project and the operational problems encountered at each site are discussed.

  13. Field Testing of Utility Robots for Lunar Surface Operations

    NASA Technical Reports Server (NTRS)

    Fong, Terrence; Bualat, Maria; Deans, Matt; Allan, Mark; Bouyssounouse, Xavier; Broxton, Michael; Edwards, Laurence; Lee, Pascal; Lee, Susan Y.; Lees, David; Park, Eric; Pedersen, Liam; Smith, Trey; To, Vinh; Utz, Hans; Pacis, Estrellina; Schreckenghost, Debra

    2008-01-01

    Since 2004, NASA has been working to return to the Moon. In contrast to the Apollo missions, two key objectives of the current exploration program is to establish significant infrastructure and an outpost. Achieving these objectives will enable long-duration stays and long-distance exploration of the Moon. To do this, robotic systems will be needed to perform tasks which cannot, or should not, be performed by crew alone. In this paper, we summarize our work to develop "utility robots" for lunar surface operations, present results and lessons learned from field testing, and discuss directions for future research.

  14. Operation and design of selected industrial process heat field tests

    SciTech Connect

    Kearney, D. W.

    1981-02-01

    The DOE program of solar industrial process heat field tests has shown solar energy to be compatible with numerous industrial needs. Both the operational projects and the detailed designs of systems that are not yet operational have resulted in valuable insights into design and hardware practice. Typical of these insights are the experiences discussed for the four projects reviewed. Future solar IPH systems should benefit greatly not only from the availability of present information, but also from the wealth of operating experience from projects due to start up in 1981.

  15. Skin disinfection in preterm infants.

    PubMed

    Malathi, I; Millar, M R; Leeming, J P; Hedges, A; Marlow, N

    1993-09-01

    Greater care and a more thorough approach to intravenous catheter site disinfection may be important for the prevention of catheter related sepsis, especially with coagulase negative staphylocci in preterm infants. The efficacy of skin disinfection was evaluated in preterm infants using a skin swabbing technique after disinfectant exposure. In the first part of the study, 25 peripheral intravascular catheter sites were quantitatively sampled immediately after routine cannula insertion. Bacterial counts greater than 100 colony forming units/cm2 were observed from 10 (40%) sites. In the second part, sampling for bacterial colony counts was done after skin cleansing with various durations of exposure of chlorhexidine/alcohol swabs or povidone iodine. The overall mean reduction in bacterial colony counts after skin cleansing ranged from 90-99%. Skin sterilisation was achieved in 33-92% of cases. The use of two consecutive 10 second exposures resulted in a significantly improved reduction in colony counts compared with a single 10 second wipe. A longer 30 second exposure also resulted in a greater reduction of bacterial numbers compared with a shorter duration of 5 or 10 seconds. Repopulation of disinfected sites occurred within 48 hours. This effect was delayed by occluding the cleansed site with a semipermeable dressing. There were no significant differences between povidone iodine and the chlorhexidine swabs in reducing bacterial numbers. This study has demonstrated that a brief exposure with a premoistened disinfectant swab is not sufficient for complete elimination of resident skin flora of newborn infants. The use of two consecutive cleanings, or a longer duration of cleansing is recommended for more effective skin sterilisation.

  16. Evaluation of propidium monoazide-quantitative PCR to detect viable Mycobacterium fortuitum after chlorine, ozone, and ultraviolet disinfection.

    PubMed

    Lee, Eun-Sook; Lee, Man-Ho; Kim, Bog-Soon

    2015-10-01

    We evaluated whether propidium monoazide (PMA) combined with real-time quantitative PCR (qPCR) is suitable for detecting viable Mycobacterium fortuitum after chlorine, ozone, and ultraviolet (UV) disinfection. PMA-qPCR was effective in determining the viability of M. fortuitum compared with qPCR based on the membrane integrity. However, with a mild chlorine concentration, PMA-qPCR as an alternative method was not applicable due to a large gap between loss of culturability and membrane integrity damage. In ozonation, PMA-qPCR was able to differentiate between viable and injured mycobacteria, and the results were similar to those obtained by the culture method. Interestingly, PMA-qPCR was successful in monitoring the viability after UV disinfection due to the long UV exposure needed to effectively inactivate M. fortuitum. The findings of the present study suggested that the characteristics of disinfectants and the M. fortuitum resistance to disinfectants play critical roles in determining the suitability of PMA-qPCR for evaluating the efficacy of disinfection methods. PMID:26143168

  17. Evaluation of propidium monoazide-quantitative PCR to detect viable Mycobacterium fortuitum after chlorine, ozone, and ultraviolet disinfection.

    PubMed

    Lee, Eun-Sook; Lee, Man-Ho; Kim, Bog-Soon

    2015-10-01

    We evaluated whether propidium monoazide (PMA) combined with real-time quantitative PCR (qPCR) is suitable for detecting viable Mycobacterium fortuitum after chlorine, ozone, and ultraviolet (UV) disinfection. PMA-qPCR was effective in determining the viability of M. fortuitum compared with qPCR based on the membrane integrity. However, with a mild chlorine concentration, PMA-qPCR as an alternative method was not applicable due to a large gap between loss of culturability and membrane integrity damage. In ozonation, PMA-qPCR was able to differentiate between viable and injured mycobacteria, and the results were similar to those obtained by the culture method. Interestingly, PMA-qPCR was successful in monitoring the viability after UV disinfection due to the long UV exposure needed to effectively inactivate M. fortuitum. The findings of the present study suggested that the characteristics of disinfectants and the M. fortuitum resistance to disinfectants play critical roles in determining the suitability of PMA-qPCR for evaluating the efficacy of disinfection methods.

  18. 9 CFR 166.14 - Cleaning and disinfecting.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... disinfecting. (a) Disinfectants to be used. Disinfection required under the regulations in this Part shall be... cresylic disinfectant that is used in accordance with directions on the EPA-approved label, provided such disinfectant also meets the requirements set forth in §§ 71.10(b) and 71.11 of this chapter. (3)...

  19. 9 CFR 166.14 - Cleaning and disinfecting.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... disinfecting. (a) Disinfectants to be used. Disinfection required under the regulations in this Part shall be... cresylic disinfectant that is used in accordance with directions on the EPA-approved label, provided such disinfectant also meets the requirements set forth in §§ 71.10(b) and 71.11 of this chapter. (3)...

  20. 9 CFR 166.14 - Cleaning and disinfecting.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... disinfecting. (a) Disinfectants to be used. Disinfection required under the regulations in this Part shall be... cresylic disinfectant that is used in accordance with directions on the EPA-approved label, provided such disinfectant also meets the requirements set forth in §§ 71.10(b) and 71.11 of this chapter. (3)...

  1. 9 CFR 166.14 - Cleaning and disinfecting.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... disinfecting. (a) Disinfectants to be used. Disinfection required under the regulations in this Part shall be... cresylic disinfectant that is used in accordance with directions on the EPA-approved label, provided such disinfectant also meets the requirements set forth in §§ 71.10(b) and 71.11 of this chapter. (3)...

  2. 9 CFR 166.14 - Cleaning and disinfecting.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... disinfecting. (a) Disinfectants to be used. Disinfection required under the regulations in this Part shall be... cresylic disinfectant that is used in accordance with directions on the EPA-approved label, provided such disinfectant also meets the requirements set forth in §§ 71.10(b) and 71.11 of this chapter. (3)...

  3. Field tests-low input, side-wall vented boiler

    SciTech Connect

    Litzke, W.L.; Butcher, T.A.; Celebi, Y.

    1996-07-01

    The Fan Atomized Burner (FAB) was developed at Brookhaven National Laboratory as part of the Oil Heat Combustion Equipment Technology Program to provide a practical low-firing rate technology leading to new, high efficiency oil-fired appliances. The development of the burner design and results of application testing have been presented in prior oil heat conferences over the past several years. This information is also summarized in a more comprehensive BNL report. The first field trial of a prototype unit was initiated during the 1994-95 heating season. This paper presents the results of the second year of testing, during the 1995-96 heating season. The field tests enable the demonstration of the reliability and performance of the FAB under practical, typical operating conditions. Another important objective of the field test was to demonstrate that the low input is adequate to satisfy the heating and hot water demands of the household. During the first field trial it was shown that at a maximum input rate of 0.4 gph (55,000 Btu/hr) the burner was able to heat a home with over 2,000 square feet of conditioned living space and provide adequate supply of domestic hot water for a family of six. The test is located in Long Island, NY.

  4. Pricetown I underground coal gasification field test: operations report

    SciTech Connect

    Agarwal, A.K.; Seabaugh, P.W.; Zielinski, R.E.

    1981-01-01

    An Underground Coal Gasification (UCG) field test in bituminous coal was successfully completed near Pricetown, West Virginia. The primary objective of this field test was to determine the viability of the linked vertical well (LVV) technology to recover the 900 foot deep, 6 foot thick coal seam. A methane rich product gas with an average heating value of approximately 250 Btu/SCF was produced at low air injection flow rates during the reverse combustion linkage phase. Heating value of the gas produced during the linkage enhancement phase was 221 Btu/SCF with air injection. The high methane formation has been attributed to the thermal and hydrocracking of tars and oils along with hydropyrolysis and hydrogasification of coal char. The high heating value of the gas was the combined effect of residence time, flow pattern, injection flow rate, injection pressure, and back pressure. During the gasification phase, a gas with an average heating value of 125 Btu/SCF was produced with only air injection, which resulted in an average energy production of 362 MMBtu/day.

  5. Site Guidelines for a Deep Borehole Field Test

    NASA Astrophysics Data System (ADS)

    Sassani, D.; Kuhlman, K. L.; Freeze, G. A.; MacKinnon, R. J.; Perry, F.

    2015-12-01

    The US DOE Office of Nuclear Energy Used Nuclear Fuel Disposition Campaign (UFDC) is initiating a Deep Borehole Field Test (DBFT), without use of any radioactive waste, to evaluate the geoscience of the approach and technical capabilities for implementation. DOE has identified Sandia National Laboratories (SNL) as the Technical Lead for the UFDC DBFT Project, with the role of supporting DOE in (i) developing the overall DBFT Project Plan, (ii) management and integration of all DBFT Project activities, and (iii) providing Project technical guidance to DOE, other DOE National Laboratories, and university partners. The DBFT includes drilling one Characterization Borehole (CB-8.5" diameter), followed by an optional Field Test Borehole (FTB), to a depth of about 5,000 m (16,400 feet) into crystalline basement rock in a geologically stable continental location. The DBFT CB will be drilled and completed to facilitate downhole scientific testing and analyses. If site conditions are found to be favorable, DOE may drill the larger-diameter (17") FTB to facilitate proof-of-concept of handling, emplacement, and retrieval activities using surrogate waste containers. Guidelines for favorable DBFT site geohydrochemical and geomechanical conditions will be discussed and status of the DBFT Project will be provided. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. SAND2015-6426A.

  6. Deep Borehole Field Test Requirements and Controlled Assumptions.

    SciTech Connect

    Hardin, Ernest

    2015-07-01

    This document presents design requirements and controlled assumptions intended for use in the engineering development and testing of: 1) prototype packages for radioactive waste disposal in deep boreholes; 2) a waste package surface handling system; and 3) a subsurface system for emplacing and retrieving packages in deep boreholes. Engineering development and testing is being performed as part of the Deep Borehole Field Test (DBFT; SNL 2014a). This document presents parallel sets of requirements for a waste disposal system and for the DBFT, showing the close relationship. In addition to design, it will also inform planning for drilling, construction, and scientific characterization activities for the DBFT. The information presented here follows typical preparations for engineering design. It includes functional and operating requirements for handling and emplacement/retrieval equipment, waste package design and emplacement requirements, borehole construction requirements, sealing requirements, and performance criteria. Assumptions are included where they could impact engineering design. Design solutions are avoided in the requirements discussion. Deep Borehole Field Test Requirements and Controlled Assumptions July 21, 2015 iv ACKNOWLEDGEMENTS This set of requirements and assumptions has benefited greatly from reviews by Gordon Appel, Geoff Freeze, Kris Kuhlman, Bob MacKinnon, Steve Pye, David Sassani, Dave Sevougian, and Jiann Su.

  7. Performance evaluation of infrared imaging system in field test

    NASA Astrophysics Data System (ADS)

    Wang, Chensheng; Guo, Xiaodong; Ren, Tingting; Zhang, Zhi-jie

    2014-11-01

    Infrared imaging system has been applied widely in both military and civilian fields. Since the infrared imager has various types and different parameters, for system manufacturers and customers, there is great demand for evaluating the performance of IR imaging systems with a standard tool or platform. Since the first generation IR imager was developed, the standard method to assess the performance has been the MRTD or related improved methods which are not perfect adaptable for current linear scanning imager or 2D staring imager based on FPA detector. For this problem, this paper describes an evaluation method based on the triangular orientation discrimination metric which is considered as the effective and emerging method to evaluate the synthesis performance of EO system. To realize the evaluation in field test, an experiment instrument is developed. And considering the importance of operational environment, the field test is carried in practical atmospheric environment. The test imagers include panoramic imaging system and staring imaging systems with different optics and detectors parameters (both cooled and uncooled). After showing the instrument and experiment setup, the experiment results are shown. The target range performance is analyzed and discussed. In data analysis part, the article gives the range prediction values obtained from TOD method, MRTD method and practical experiment, and shows the analysis and results discussion. The experimental results prove the effectiveness of this evaluation tool, and it can be taken as a platform to give the uniform performance prediction reference.

  8. A possible field test for marine cloud brightening geoengineering. A possible field test for marine cloud brightening geoengineering

    NASA Astrophysics Data System (ADS)

    Gadian, A.; Wood, R.; Coe, H.; Latham, J.

    2011-12-01

    A possible field test for marine cloud brightening geoengineering. Abstract: The Marine Cloud Brightening (MCB) geoengineering technique (Latham et al 2008) hypothesizes that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre seawater particles can enhance the cloud droplet number concentration and increase cloud albedo. Here, we propose a set of field tests to critically assess the efficacy of the MCB geoengineering proposal over a limited area. The tests are de minimus with respect to their climate effects. The tests involve three phases, with increasing logistical complexity, each of which is designed to test one or more important components of the cloud brightening scheme. Each involves the introduction and monitoring of controlled aerosol perturbations from one or more ship-based seeding platforms up to a limited area of 100x100 km2. A suite of observational platforms of increasing number and complexity, including aircraft, ships and satellites, will observe the aerosol plume and in the later experiments the cloud and albedo responses to the aerosol perturbations. These responses must include the necessary cloud physical and chemical processes which determine the efficacy of the cloud brightening scheme. Since these processes are also central to the broader problem of aerosol-cloud-climate interactions, such field tests would have significant benefits for climate science in addition to providing a critical test of the MCB hypothesis. Such field experiments should be designed and conducted in an objective manner within the framework of emerging geoengineering research governance structures. Reference: Latham J. et al.. (2008) Global temperature stabilization via controlled albedo enhancement of low-level maritime clouds. Phil. Trans. R. Soc. A doi:10.1098/rsta.2008.0137

  9. DISINFECTION BY-PRODUCT FORMATION BY ALTERNATIVE DISINFECTANTS AND REMOVAL BY GRANULAR ACTIVATED CARBON

    EPA Science Inventory

    The effects of the use of the alternative disinfectants on the formation of halogenated disinfection by–products (DBPs) including total organic halide, trihalomethanes, haloacetic acids, haloacetonitriles, haloketones, chloral hydrate, and chloropicrin, were examined along ...

  10. Efficacy of an Automated Multiple Emitter Whole-Room Ultraviolet-C Disinfection System Against Coronaviruses MHV and MERS-CoV.

    PubMed

    Bedell, Kurt; Buchaklian, Adam H; Perlman, Stanley

    2016-05-01

    Efficient and automated methods of disinfecting surfaces contaminated with the Middle Eastern respiratory syndrome coronavirus (MERS-CoV) may prevent the spread of the virus. Here we report the efficacy and use of an automated triple-emitter whole room UV-C disinfection system to inactivate mouse hepatitis virus, strain A59 (MHV-A59) and MERS-CoV viruses on surfaces with a >5 log10 reduction.

  11. Status report on analytical methods to support the disinfectant/disinfection by-products regulation

    SciTech Connect

    Not Available

    1992-08-01

    The U.S. EPA is developng national regulations to control disinfectants and disinfection by-products in public drinking water supplies. Twelve disinfectants and disinfection by-products are identified for possible regulation under this rule. The document summarizes the analytical methods that EPA intends to propose as compliance monitoring methods. A discussion of surrogate measurements that are being considered for inclusion in the regulation is also provided.

  12. Transformation pathways and acute toxicity variation of 4-hydroxyl benzophenone in chlorination disinfection process.

    PubMed

    Liu, Wei; Wei, Dongbin; Liu, Qi; Du, Yuguo

    2016-07-01

    Benzophenones compounds (BPs) are widely used as UV filters, and have been frequently found in multiple environmental matrices. The residual of BPs in water would cause potential threats on ecological safety and human health. Chlorination disinfection is necessary in water treatment process, in which many chemicals remained in water would react with disinfectant chlorine and form toxic by-products. By using ultra performance liquid phase chromatography quadrupole time of flight mass spectrometer (UPLC-QTOF-MS), nuclear magnetic resonance (NMR), the transformation of 4-hydroxyl benezophenone (4HB) with free available chlorine (FAC) was characterized. Eight major products were detected and seven of them were identified. Transformation pathways of 4HB under acid, neutral, and alkaline conditions were proposed respectively. The transformation mechanisms involved electrophilic chlorine substitution of 4HB, Baeyer-Villiger oxidation of ketones, hydrolysis of esters and oxidative breakage of benzene ring. The orthogonal experiments of pH and dosages of disinfectant chlorine were conducted. The results suggested that pH conditions determined the occurrence of reaction types, and the dosages of disinfectant chlorine affected the extent of reactions. Photobacterium assay demonstrated that acute toxicity had significant increase after chlorination disinfection of 4HB. It was proved that 3,5-dichloro-4HB, one of the major transformation products, was responsible for the increasing acute toxicity after chlorination. It is notable that, 4HB at low level in real ambient water matrices could be transformed during simulated chlorination disinfection practice. Especially, two major products 3-chloro-4HB and 3,5-dichloro-4HB were detected out, implying the potential ecological risk after chlorination disinfection of 4HB.

  13. Transformation pathways and acute toxicity variation of 4-hydroxyl benzophenone in chlorination disinfection process.

    PubMed

    Liu, Wei; Wei, Dongbin; Liu, Qi; Du, Yuguo

    2016-07-01

    Benzophenones compounds (BPs) are widely used as UV filters, and have been frequently found in multiple environmental matrices. The residual of BPs in water would cause potential threats on ecological safety and human health. Chlorination disinfection is necessary in water treatment process, in which many chemicals remained in water would react with disinfectant chlorine and form toxic by-products. By using ultra performance liquid phase chromatography quadrupole time of flight mass spectrometer (UPLC-QTOF-MS), nuclear magnetic resonance (NMR), the transformation of 4-hydroxyl benezophenone (4HB) with free available chlorine (FAC) was characterized. Eight major products were detected and seven of them were identified. Transformation pathways of 4HB under acid, neutral, and alkaline conditions were proposed respectively. The transformation mechanisms involved electrophilic chlorine substitution of 4HB, Baeyer-Villiger oxidation of ketones, hydrolysis of esters and oxidative breakage of benzene ring. The orthogonal experiments of pH and dosages of disinfectant chlorine were conducted. The results suggested that pH conditions determined the occurrence of reaction types, and the dosages of disinfectant chlorine affected the extent of reactions. Photobacterium assay demonstrated that acute toxicity had significant increase after chlorination disinfection of 4HB. It was proved that 3,5-dichloro-4HB, one of the major transformation products, was responsible for the increasing acute toxicity after chlorination. It is notable that, 4HB at low level in real ambient water matrices could be transformed during simulated chlorination disinfection practice. Especially, two major products 3-chloro-4HB and 3,5-dichloro-4HB were detected out, implying the potential ecological risk after chlorination disinfection of 4HB. PMID:27085063

  14. 9 CFR 91.41 - Cleaning and disinfecting of aircraft.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... animals on the aircraft shall be cleaned and disinfected using an approved disinfectant listed in § 71.10... stowage area. The disinfectant solution must be applied with a device that creates an aerosol or mist...

  15. DRINKING WATER DISINFECTION BY-PRODUCTS: WHAT IS KNOWN

    EPA Science Inventory

    Chlorine, ozone, chlorine dioxide, and chloramine are currently the major disinfectants being used to disinfect drinking water. Although the alternative disinfectants (ozone, chlorine dioxide, and chloramine) are increasing in popularity in the United States, chlorine is still us...

  16. Field Tested Service Oriented Robotic Architecture: Case Study

    NASA Technical Reports Server (NTRS)

    Flueckiger, Lorenzo; Utz, Hanz

    2012-01-01

    This paper presents the lessons learned from six years of experiments with planetary rover prototypes running the Service Oriented Robotic Architecture (SORA) developed by the Intelligent Robotics Group (IRG) at NASA Ames Research Center. SORA relies on proven software methods and technologies applied to the robotic world. Based on a Service Oriented Architecture and robust middleware, SORA extends its reach beyond the on-board robot controller and supports the full suite of software tools used during mission scenarios from ground control to remote robotic sites. SORA has been field tested in numerous scenarios of robotic lunar and planetary exploration. The results of these high fidelity experiments are illustrated through concrete examples that have shown the benefits of using SORA as well as its limitations.

  17. Antarctic field tests of SARSAT personal locater beacons

    NASA Technical Reports Server (NTRS)

    Bindschadler, Robert

    1987-01-01

    Field tests of SARSAT personal locater beacons were conducted in the Antarctic to assess the viability of using these beacons to increase the safety of Antarctic field parties. Data were collected on the extent to which dry or wet snow, melting conditions, crevasse walls and snow bridges affected the ability of the SARSAT satellite to calculate an accurate position of the beacon. Average response time between beacon turn on and alert reception in McMurdo was between 4 and 5 hours for these tests. It is concluded that the SARSAT system is viable for Antarctic operations and it is recommended that it be implemented for future field operations. Because of obstruction of line-of-sight between beacon and satellite degrades the accuracy of the location calculation (particularly in wet snow), it is further recommended that field parties have sufficient numbers of beacons to insure that in an emergency, one will be able to operate from the surface.

  18. A field test of a simple stochastic radiative transfer model

    SciTech Connect

    Byrne, N.

    1995-09-01

    The problem of determining the effect of clouds on the radiative energy balance of the globe is of well-recognized importance. One can in principle solve the problem for any given configuration of clouds using numerical techniques. This knowledge is not useful however, because of the amount of input data and computer resources required. Besides, we need only the average of the resulting solution over the grid scale of a general circulation model (GCM). Therefore, we are interested in estimating the average of the solutions of such fine-grained problems using only coarse grained data, a science or art called stochastic radiation transfer. Results of the described field test indicate that the stochastic description is a somewhat better fit to the data than is a fractional cloud cover model, but more data are needed. 1 ref., 3 figs.

  19. Non-contact rail flaw detection system: first field test

    NASA Astrophysics Data System (ADS)

    Rizzo, Piervincenzo; Coccia, Stefano; Lanza di Scalea, Francesco; Bartoli, Ivan; Fateh, Mahmood

    2007-04-01

    Researchers at UCSD, with the initial support of NSF and the current support of the Federal Railroad Administration (FRA), have been working on a flaw detection prototype for rails that uses non-contact ultrasonic probing and robust data processing algorithms to provide high speed and high reliability defect detection in these structures. Besides the obvious advantages of non-contact probing, the prototype uses ultrasonic guided waves able to detect and quantify transverse cracks in the rail head, notoriously the most dangerous of all rail track defects. This paper will report on the first field test which was conducted in Gettysburg, PA in March 2006 with the technical support of ENSCO, Inc. Good results were obtained for the detection of both surface-breaking and internal cracks ranging in size from 2% cross-sectional head area (H.A.) reduction to 80% H.A. reduction.

  20. Results of field testing the cement evaluation tool

    SciTech Connect

    Leigh, C.A.; Finlayson, C.G.; Van der Kolk, C.

    1984-01-01

    The Cement Evaluation Tool (CET) developed by Schlumberger employs a pulse-echo technique using eight sonic transducers to investigate the casing cement bond. The tool has been widely field tested in a clastic environment in Brunei (N.W. Borneo), across both oil and gas bearing reservoirs. Numerous comparisons of the CET with conventional CBL/VDL logs have been made. Across oil and water bearing intervals the CET is shown to compare favourably with the CBL/VDL and yields significant additional information on channeling, cement distribution, and the success of casing centralization. In addition, the accuracy of the acoustic calipers have proved sufficient to be used in assisting drilling and completion operations. The response of the tool to a microannulus has also been demonstrated by multiple runs under varying wellbore pressures.

  1. Field test plan: Buried waste technologies, Fiscal Year 1995

    SciTech Connect

    Heard, R.E.; Hyde, R.A.; Engleman, V.S.; Evans, J.D.; Jackson, T.W.

    1995-06-01

    The US Department of Energy, Office of Technology Development, supports the applied research, development, demonstration, testing, and evaluation of a suite of advanced technologies that, when integrated with commercially available baseline technologies, form a comprehensive remediation system for the effective and efficient remediation of buried waste. The Fiscal Year 1995 effort is to deploy and test multiple technologies from four functional areas of buried waste remediation: site characterization, waste characterization, retrieval, and treatment. This document is the basic operational planning document for the deployment and testing of the technologies that support the field testing in Fiscal Year 1995. Discussed in this document are the scope of the tests; purpose and objective of the tests; organization and responsibilities; contingency plans; sequence of activities; sampling and data collection; document control; analytical methods; data reduction, validation, and verification; quality assurance; equipment and instruments; facilities and utilities; health and safety; residuals management; and regulatory management.

  2. Detailed field test of yaw-based wake steering

    NASA Astrophysics Data System (ADS)

    Fleming, P.; Churchfield, M.; Scholbrock, A.; Clifton, A.; Schreck, S.; Johnson, K.; Wright, A.; Gebraad, P.; Annoni, J.; Naughton, B.; Berg, J.; Herges, T.; White, J.; Mikkelsen, T.; Sjöholm, M.; Angelou, N.

    2016-09-01

    This paper describes a detailed field-test campaign to investigate yaw-based wake steering. In yaw-based wake steering, an upstream turbine intentionally misaligns its yaw with respect to the inflow to deflect its wake away from a downstream turbine, with the goal of increasing total power production. In the first phase, a nacelle-mounted scanning lidar was used to verify wake deflection of a misaligned turbine and calibrate wake deflection models. In the second phase, these models were used within a yaw controller to achieve a desired wake deflection. This paper details the experimental design and setup. All data collected as part of this field experiment will be archived and made available to the public via the U.S. Department of Energy's Atmosphere to Electrons Data Archive and Portal.

  3. SMART wind turbine rotor. Design and field test

    SciTech Connect

    Berg, Jonathan Charles; Resor, Brian Ray; Paquette, Joshua A.; White, Jonathan Randall

    2014-01-01

    The Wind Energy Technologies department at Sandia National Laboratories has developed and field tested a wind turbine rotor with integrated trailing-edge flaps designed for active control of rotor aerodynamics. The SMART Rotor project was funded by the Wind and Water Power Technologies Office of the U.S. Department of Energy (DOE) and was conducted to demonstrate active rotor control and evaluate simulation tools available for active control research. This report documents the design, fabrication, and testing of the SMART Rotor. This report begins with an overview of active control research at Sandia and the objectives of this project. The SMART blade, based on the DOE / SNL 9-meter CX-100 blade design, is then documented including all modifications necessary to integrate the trailing edge flaps, sensors incorporated into the system, and the fabrication processes that were utilized. Finally the test site and test campaign are described.

  4. Field test of a post-closure radiation monitor

    SciTech Connect

    Reed, S.; Christy, C.E.; Heath, R.E.

    1995-12-01

    The DOE is conducting remedial actions at many sites contaminated with radioactive materials. After closure of these sites, long-term subsurface monitoring is typically required by law. This monitoring is generally labor intensive and expensive using conventional sampling and analysis techniques. The U.S. Department of Energy`s Morgantown Energy Technology Center (METC) has contracted with Babcock and Wilcox to develop a Long-Term Post-Closure Radiation Monitoring System (LPRMS) to reduce these monitoring costs. A prototype LPRMS probe was built, and B&W and FERMCO field tested this monitoring probe at the Fernald Environmental Management Project in the fall of 1994 with funding from the DOE`s Office of Technology Development (EM-50) through METC. The system was used to measure soil and water with known uranium contamination levels, both in drums and in situ at depths up to 3 meters. For comparison purposes, measurements were also performed using a more conventional survey probe with a sodium iodide scintillator directly butt-coupled to detection electronics. This paper presents a description and the results of the field tests. The results were used to characterize the lower detection limits, precision and bias of the system, which allowed the DOE to judge the monitoring system`s ability to meet its long-term post-closure radiation monitoring needs. Based on the test results, the monitoring system has been redesigned for fabrication and testing in a potential Phase III of this program. If the DOE feels that this system can meet its needs and chooses to continue into Phase III of this program, this redesigned full scale prototype system will be built and tested for a period of approximately a year. Such a system can be used at a variety of radioactively contaminated sites.

  5. Comparison of two aerobic field tests in young tennis players.

    PubMed

    Fargeas-Gluck, Marie-Agnès; Léger, Luc A

    2012-11-01

    This study compares the maximal responses of a new aerobic tennis field test, the NAVTEN to a known aerobic field test, often used with young tennis players, that is, the continuous multistage 20-m shuttle run test (20-m SRT). The NAVTEN is an intermittent (1-minute/1-minute) multistage test with side-to-side displacements and ball hitting. Ten young elite tennis players aged 12.9 ± 0.3 (mean ± SD) randomly performed both tests and were continuously monitored for heart rate (HR) and oxygen uptake (V[Combining Dot Above]O2) using the Vmax ST (Sensormedics). The 20-m SRT and NAVTEN show similar HRpeak (202 ± 6.1 vs. 208 ± 9.5, respectively) and V[Combining Dot Above]O2peak (54.2 ± 5.9 vs. 54.9 ± 6.0 ml·kg·min). Pearson correlations between both tests were 0.88 and 0.92 for V[Combining Dot Above]O2peak and maximal speed, respectively. The NAVTEN yielded V[Combining Dot Above]O2peak values that are typical for active subjects of that age and are similar to the 20-m SRT supporting its use to measure aerobic fitness of young tennis players in specific and entertaining field conditions. The fact that two-thirds of the tennis players achieved a different ranking (±1 rank) with the NAVTEN and the 20-m SRT suggests that the NAVTEN may be more specific than the 20-m SRT to assess aerobic fitness of tennis players. From a practical point of view, the NAVTEN test is more specific and pedagogical for young tennis players even though both tests yield similar maximal values.

  6. Ultra violet disinfection: A 3-year history

    SciTech Connect

    Tubesing, R.R.; Lindeke, D.R.

    1998-07-01

    The Stillwater Wastewater Treatment Facility is one of nine wastewater treatment facilities operated by the Metropolitan Council Environmental Services in the Minneapolis-St. Paul Metropolitan Area. The facility services the cities of Stillwater, Oak Park Heights, and Bayport. In 1993, an ultra violet disinfection facility began operation to provide the disinfection for the Facility. This presentation discusses the reasons for using ultra violet disinfection in lieu of chlorination/dechlorination facilities, the operating performance, and operating cost factors.

  7. Disinfection Addition and Disinfection Changes: What It Means to the LCR

    EPA Science Inventory

    This slide presentation’s general points are: Many protective pipe scales are vey dependent on ORP, and hence, state of disinfection. Adding disinfection to anoxic systems will likely cause big chemistry changes in DS and corrosion. Changing disinfectants could cause major l...

  8. Disinfecting Filters For Recirculated Air

    NASA Technical Reports Server (NTRS)

    Pilichi, Carmine A.

    1992-01-01

    Simple treatment disinfects air filters by killing bacteria, algae, fungi, mycobacteria, viruses, spores, and any other micro-organisms filters might harbor. Concept applied to reusable stainless-steel wire mesh filters and disposable air filters. Treatment used on filters in air-circulation systems in spacecraft, airplanes, other vehicles, and buildings to help prevent spread of colds, sore throats, and more-serious illnesses.

  9. Remote sensing and field test capabilities at U.S. Army Dugway Proving Ground

    NASA Astrophysics Data System (ADS)

    Pearson, James T.; Herron, Joshua P.; Marshall, Martin S.

    2012-05-01

    U.S. Army Dugway Proving Ground (DPG) is a Major Range and Test Facility Base (MRTFB) with the mission of testing chemical and biological defense systems and materials. DPG facilities include state-of-the-art laboratories, extensive test grids, controlled environment calibration facilities, and a variety of referee instruments for required test measurements. Among these referee instruments, DPG has built up a significant remote sensing capability for both chemical and biological detection. Technologies employed for remote sensing include FTIR spectroscopy, UV spectroscopy, Raman-shifted eye-safe lidar, and other elastic backscatter lidar systems. These systems provide referee data for bio-simulants, chemical simulants, toxic industrial chemicals (TICs), and toxic industrial materials (TIMs). In order to realize a successful large scale open-air test, each type of system requires calibration and characterization. DPG has developed specific calibration facilities to meet this need. These facilities are the Joint Ambient Breeze Tunnel (JABT), and the Active Standoff Chamber (ASC). The JABT and ASC are open ended controlled environment tunnels. Each includes validation instrumentation to characterize simulants that are disseminated. Standoff systems are positioned at typical field test distances to measure characterized simulants within the tunnel. Data from different types of systems can be easily correlated using this method, making later open air test results more meaningful. DPG has a variety of large scale test grids available for field tests. After and during testing, data from the various referee instruments is provided in a visual format to more easily draw conclusions on the results. This presentation provides an overview of DPG's standoff testing facilities and capabilities, as well as example data from different test scenarios.

  10. Remote sensing and field test capabilities at U.S. Army Dugway Proving Ground

    NASA Astrophysics Data System (ADS)

    Pearson, James T.; Herron, Joshua P.; Marshall, Martin S.

    2011-11-01

    U.S. Army Dugway Proving Ground (DPG) is a Major Range and Test Facility Base (MRTFB) with the mission of testing chemical and biological defense systems and materials. DPG facilities include state-of-the-art laboratories, extensive test grids, controlled environment calibration facilities, and a variety of referee instruments for required test measurements. Among these referee instruments, DPG has built up a significant remote sensing capability for both chemical and biological detection. Technologies employed for remote sensing include FTIR spectroscopy, UV spectroscopy, Raman-shifted eye-safe lidar, and other elastic backscatter lidar systems. These systems provide referee data for bio-simulants, chemical simulants, toxic industrial chemicals (TICs), and toxic industrial materials (TIMs). In order to realize a successful large scale open-air test, each type of system requires calibration and characterization. DPG has developed specific calibration facilities to meet this need. These facilities are the Joint Ambient Breeze Tunnel (JABT), and the Active Standoff Chamber (ASC). The JABT and ASC are open ended controlled environment tunnels. Each includes validation instrumentation to characterize simulants that are disseminated. Standoff systems are positioned at typical field test distances to measure characterized simulants within the tunnel. Data from different types of systems can be easily correlated using this method, making later open air test results more meaningful. DPG has a variety of large scale test grids available for field tests. After and during testing, data from the various referee instruments is provided in a visual format to more easily draw conclusions on the results. This presentation provides an overview of DPG's standoff testing facilities and capabilities, as well as example data from different test scenarios.

  11. Decontamination formulations for disinfection and sterilization

    DOEpatents

    Tucker, Mark D.; Engler, Daniel E.

    2007-09-18

    Aqueous decontamination formulations that neutralize biological pathogens for disinfection and sterilization applications. Examples of suitable applications include disinfection of food processing equipment, disinfection of areas containing livestock, mold remediation, sterilization of medical instruments and direct disinfection of food surfaces, such as beef carcasses. The formulations include at least one reactive compound, bleaching activator, inorganic base, and water. The formulations can be packaged as a two-part kit system, and can have a pH value in the range of 7-8.

  12. Transformation of pharmaceuticals during oxidation/disinfection processes in drinking water treatment.

    PubMed

    Postigo, Cristina; Richardson, Susan D

    2014-08-30

    Pharmaceuticals are emerging contaminants of concern and are widespread in the environment. While the levels of these substances in finished drinking waters are generally considered too low for human health concern, there are now concerns about their disinfection by-products (DBPs) that can form during drinking water treatment, which in some cases have been proven to be more toxic than the parent compounds. The present manuscript reviews the transformation products of pharmaceuticals generated in water during different disinfection processes, i.e. chlorination, ozonation, chloramination, chlorine dioxide, UV, and UV/hydrogen peroxide, and the main reaction pathways taking place. Most of the findings considered for this review come from controlled laboratory studies involving reactions of pharmaceuticals with these oxidants used in drinking water treatment.

  13. Comparative evaluation of iodoacids removal by UV/persulfate and UV/H2O2 processes.

    PubMed

    Xiao, Yongjun; Zhang, Lifeng; Zhang, Wei; Lim, Kok-Yong; Webster, Richard D; Lim, Teik-Thye

    2016-10-01

    To develop a cost-effective method for post-formation mitigation of iodinated disinfection by-products, degradation of iodoacids by UV, UV/PS (persulfate), and UV/H2O2 was extensively investigated in this study. UV direct photolysis of 4 iodoacids followed first-order kinetics with rate constants in the range of 2.43 × 10(-4)-3.02 × 10(-3) cm(2) kJ(-1). The derived quantum yields (Ф254) of the 4 iodoacids range from 0.13 to 0.34, respectively. A quantitative structure-activity relationship (QSAR) model was subsequently established and applied to predict the direct photolysis rates of 6 other structurally similar iodoacids whose standards are commercially unavailable. At a UV dose of 140 mJ cm(-2) which is typically applied for disinfection of drinking water, the removal percentages of 4 iodoacids were only between 3.35% and 34.7%. Thus, ICH2CO2H (IAA), the most photo-recalcitrant species, was selected as the target compound for removal in the UV/PS and UV/H2O2 processes. The IAA degradation rates decreased with increasing pH from 3 to 11 in both processes. Humic acid (HA) and HCO3(-) had inhibitory effects on IAA degradation in both processes. Cl(-) adversely affected the IAA degradation in the UV/PS process but had no effect in the UV/H2O2 process. Generally, in the deionized (DI) water, surface water, treated drinking water, and secondary effluent, UV/PS process is more effective than UV/H2O2 process for IAA removal, based on the same molar ratio of oxidant: IAA. SO4(-) generated in the UV/PS process yields a greater mineralization of IAA than HO in the UV/H2O2 process. IO3(-) was the predominant end-product in the UV/PS process, while I(-) was the major end-product in the UV/H2O2 process. The respective contributions of UV, HO, and SO4(-) for IAA removal in the UV/PS process were 7.8%, 14.7%, and 77.5%, respectively, at a specific condition (1.5 μM IAA, 60 μM oxidant, and pH 7). Compared to UV/H2O2 process, UV/PS was also observed as more cost

  14. Comparative evaluation of iodoacids removal by UV/persulfate and UV/H2O2 processes.

    PubMed

    Xiao, Yongjun; Zhang, Lifeng; Zhang, Wei; Lim, Kok-Yong; Webster, Richard D; Lim, Teik-Thye

    2016-10-01

    To develop a cost-effective method for post-formation mitigation of iodinated disinfection by-products, degradation of iodoacids by UV, UV/PS (persulfate), and UV/H2O2 was extensively investigated in this study. UV direct photolysis of 4 iodoacids followed first-order kinetics with rate constants in the range of 2.43 × 10(-4)-3.02 × 10(-3) cm(2) kJ(-1). The derived quantum yields (Ф254) of the 4 iodoacids range from 0.13 to 0.34, respectively. A quantitative structure-activity relationship (QSAR) model was subsequently established and applied to predict the direct photolysis rates of 6 other structurally similar iodoacids whose standards are commercially unavailable. At a UV dose of 140 mJ cm(-2) which is typically applied for disinfection of drinking water, the removal percentages of 4 iodoacids were only between 3.35% and 34.7%. Thus, ICH2CO2H (IAA), the most photo-recalcitrant species, was selected as the target compound for removal in the UV/PS and UV/H2O2 processes. The IAA degradation rates decreased with increasing pH from 3 to 11 in both processes. Humic acid (HA) and HCO3(-) had inhibitory effects on IAA degradation in both processes. Cl(-) adversely affected the IAA degradation in the UV/PS process but had no effect in the UV/H2O2 process. Generally, in the deionized (DI) water, surface water, treated drinking water, and secondary effluent, UV/PS process is more effective than UV/H2O2 process for IAA removal, based on the same molar ratio of oxidant: IAA. SO4(-) generated in the UV/PS process yields a greater mineralization of IAA than HO in the UV/H2O2 process. IO3(-) was the predominant end-product in the UV/PS process, while I(-) was the major end-product in the UV/H2O2 process. The respective contributions of UV, HO, and SO4(-) for IAA removal in the UV/PS process were 7.8%, 14.7%, and 77.5%, respectively, at a specific condition (1.5 μM IAA, 60 μM oxidant, and pH 7). Compared to UV/H2O2 process, UV/PS was also observed as more cost

  15. Institutional Tuberculosis Transmission. Controlled Trial of Upper Room Ultraviolet Air Disinfection: A Basis for New Dosing Guidelines

    PubMed Central

    Mphaphlele, Matsie; Dharmadhikari, Ashwin S.; Jensen, Paul A.; Rudnick, Stephen N.; van Reenen, Tobias H.; Pagano, Marcello A.; Leuschner, Wilhelm; Sears, Tim A.; Milonova, Sonya P.; van der Walt, Martie; Stoltz, Anton C.; Weyer, Karin

    2015-01-01

    Rationale: Transmission is driving the global tuberculosis epidemic, especially in congregate settings. Worldwide, natural ventilation is the most common means of air disinfection, but it is inherently unreliable and of limited use in cold climates. Upper room germicidal ultraviolet (UV) air disinfection with air mixing has been shown to be highly effective, but improved evidence-based dosing guidelines are needed. Objectives: To test the efficacy of upper room germicidal air disinfection with air mixing to reduce tuberculosis transmission under real hospital conditions, and to define the application parameters responsible as a basis for proposed new dosing guidelines. Methods: Over an exposure period of 7 months, 90 guinea pigs breathed only untreated exhaust ward air, and another 90 guinea pigs breathed only air from the same six-bed tuberculosis ward on alternate days when upper room germicidal air disinfection was turned on throughout the ward. Measurements and Main Results: The tuberculin skin test conversion rates (>6 mm) of the two chambers were compared. The hazard ratio for guinea pigs in the control chamber converting their skin test to positive was 4.9 (95% confidence interval, 2.8–8.6), with an efficacy of approximately 80%. Conclusions: Upper room germicidal UV air disinfection with air mixing was highly effective in reducing tuberculosis transmission under hospital conditions. These data support using either a total fixture output (rather than electrical or UV lamp wattage) of 15–20 mW/m3 total room volume, or an average whole-room UV irradiance (fluence rate) of 5–7 μW/cm2, calculated by a lighting computer-assisted design program modified for UV use. PMID:25928547

  16. Effect of Disinfectants on Glucose Monitors

    PubMed Central

    Mahoney, John J; Lim, Christine G

    2012-01-01

    Background Monitoring blood glucose levels is an integral part of routine diabetes management. To minimize the risk of transmission of bloodborne pathogens during monitoring, the Centers for Disease Control and Prevention (CDC) recommends that glucose meters be disinfected after each use whenever they are used to test multiple patients. The objective of this study is to assess the compatibility of some common disinfectants with certain blood glucose meter systems. Methods We tested six disinfectants for adverse impact on meter performance or the exterior meter surfaces. The disinfectants tested were 0.525% sodium hypochlorite, 20% 2-propanol and 10% ethanol, 17.2% isopropanol, 55% isopropanol, 70% isopropanol, and hydrogen peroxide. To assess meter performance, we tested OneTouch® Ultra® blood glucose monitoring systems with control solution before and after application of either water or disinfectant. To assess the effect on exterior meter surfaces, we performed a soaking test to simulate long-term exposure to disinfectant. Results Paired t-test results showed that the control solution data associated with disinfectant and with water application were not significantly different for each meter type. However, most of the meter types were adversely affected by hydrogen peroxide and/or by the higher concentrations of alcohol-based disinfectants. Conclusions Although none of the six disinfectants affected meter performance, hydrogen peroxide and isopropanol >20% adversely affected the exterior surfaces of the tested meters. When complying with CDC instructions for meter disinfection, users should use caution and choose disinfectants that have been validated by the meter manufacturer. PMID:22401326

  17. Synergistic effect of solar radiation and solar heating to disinfect drinking water sources.

    PubMed

    Rijal, G K; Fujioka, R S

    2001-01-01

    Waterborne diseases are still common in developing countries as drinking water sources are contaminated and feasible means to reliably treat and disinfect these waters are not available. Many of these developing countries are in the tropical regions of the world where sunlight is plentiful. The objective of this study was to evaluate the effectiveness of combining solar radiation and solar heating to disinfect contaminated water using a modified Family Sol*Saver System (FSP). The non-UV transmittable cover sheet of the former FSP system was replaced with an UV transmittable plastic cover sheet to enable more wavelengths of sunlight to treat the water. Disinfection efficiency of both systems was evaluated based on reduction of the natural populations of faecal coliform, E. coli, enterococci, C. perfringens, total heterotrophic bacteria, hydrogen sulphide producing bacteria and FRNA virus. The results showed that under sunny and partly sunny conditions, water was heated to critical temperature (60 degrees C) in both the FSP systems inactivating more than 3 log (99.9%) of the concentrations of faecal coliform and E. coli to undetectable levels of < 1 CFU/100 mL within 2-5 h exposure to sunlight. However, under cloudy conditions, the two FSP systems did not reduce the concentrations of faecal indicator bacteria to levels of < 1 CFU/100 mL. Nonetheless, sufficient evidence was obtained to show that UV radiation of sunlight plus heat worked synergistically to enhance the inactivation of faecal indicator bacteria. The relative log removal of indicator microorganism in the FSP treated water was total heterotrophic bacteria < C. perfringens < F RNA virus < enterococci < E. coli < faecal coliform. In summary, time of exposure to heat and radiation effects of sunlight were important in disinfecting water by solar units. The data indicated that direct radiation of sunlight worked synergistically with solar heating of the water to disinfect the water. Thus, effective

  18. Synergistic effect of solar radiation and solar heating to disinfect drinking water sources.

    PubMed

    Rijal, G K; Fujioka, R S

    2001-01-01

    Waterborne diseases are still common in developing countries as drinking water sources are contaminated and feasible means to reliably treat and disinfect these waters are not available. Many of these developing countries are in the tropical regions of the world where sunlight is plentiful. The objective of this study was to evaluate the effectiveness of combining solar radiation and solar heating to disinfect contaminated water using a modified Family Sol*Saver System (FSP). The non-UV transmittable cover sheet of the former FSP system was replaced with an UV transmittable plastic cover sheet to enable more wavelengths of sunlight to treat the water. Disinfection efficiency of both systems was evaluated based on reduction of the natural populations of faecal coliform, E. coli, enterococci, C. perfringens, total heterotrophic bacteria, hydrogen sulphide producing bacteria and FRNA virus. The results showed that under sunny and partly sunny conditions, water was heated to critical temperature (60 degrees C) in both the FSP systems inactivating more than 3 log (99.9%) of the concentrations of faecal coliform and E. coli to undetectable levels of < 1 CFU/100 mL within 2-5 h exposure to sunlight. However, under cloudy conditions, the two FSP systems did not reduce the concentrations of faecal indicator bacteria to levels of < 1 CFU/100 mL. Nonetheless, sufficient evidence was obtained to show that UV radiation of sunlight plus heat worked synergistically to enhance the inactivation of faecal indicator bacteria. The relative log removal of indicator microorganism in the FSP treated water was total heterotrophic bacteria < C. perfringens < F RNA virus < enterococci < E. coli < faecal coliform. In summary, time of exposure to heat and radiation effects of sunlight were important in disinfecting water by solar units. The data indicated that direct radiation of sunlight worked synergistically with solar heating of the water to disinfect the water. Thus, effective

  19. Portable narcotics detector and the results obtained in field tests

    NASA Astrophysics Data System (ADS)

    Tumer, Tumay O.; Su, Chih-Wu; Kaplan, Christopher R.; Rigdon, Stephen W.

    1997-02-01

    A compact integrated narcotics detection instrument (CINDI) has been developed at NOVA R&D, Inc. with funding provided by the U.S. Coast Guard. CINDI is designed as a portable sensitive neutron backscatter detector which has excellent penetration for thick and high Z compartment barriers. It also has a highly sensitive detection system for backscattered neutrons and, therefore, uses a very weak californium-252 neutron source. Neutrons backscatter profusely from materials that have a large hydrogen content, such as narcotics. The rate of backscattered neutrons detected is analyzed by a microprocessor and displayed on the control panel. The operator guides the detector along a suspected area and displays in real time the backscattered neutron rate. CINDI is capable of detecting narcotics effectively behind panels made of steel, wood, fiberglass, or even lead-lined materials. This makes it useful for inspecting marine vessels, ship bulkheads, automobiles, structure walls or small sealed containers. The strong response of CINDI to hydrogen-rich materials such as narcotics makes it an effective tool for detecting concealed drugs. Its response has been field tested by NOVA, the U.S. Coast Guard and Brewt Power Systems. The results of the tests show excellent response and specificity to narcotic drugs. Several large shipments of concealed drugs have been discovered during these trials and the results are presented and discussed.

  20. Cooperative field test program for wind systems. Final report

    SciTech Connect

    Bollmeier, W.S. II; Dodge, D.M.

    1992-03-01

    The objectives of the Federal Wind Energy Program, managed by the US Department of Energy (DOE), are (1) to assist industry and utilities in achieving a multi-regional US market penetration of wind systems, and (2) to establish the United States as the world leader in the development of advanced wind turbine technology. In 1984, the program conducted a series of planning workshops with representatives from the wind energy industry to obtain input on the Five-Year Research Plan then being prepared by DOE. One specific suggestion that came out of these meetings was that the federal program should conduct cooperative research tests with industry to enhance the technology transfer process. It was also felt that the active involvement of industry in DOE-funded research would improve the state of the art of wind turbine technology. DOE established the Cooperative Field Test Program (CFTP) in response to that suggestion. This program was one of the first in DOE to feature joint industry-government research test teams working toward common objectives.

  1. The Savannah River Technology Center environmental monitoring field test platform

    SciTech Connect

    Rossabi, J.

    1993-03-05

    Nearly all industrial facilities have been responsible for introducing synthetic chemicals into the environment. The Savannah River Site is no exception. Several areas at the site have been contaminated by chlorinated volatile organic chemicals. Because of the persistence and refractory nature of these contaminants, a complete clean up of the site will take many years. A major focus of the mission of the Environmental Sciences Section of the Savannah River Technology Center is to develop better, faster, and less expensive methods for characterizing, monitoring, and remediating the subsurface. These new methods can then be applied directly at the Savannah River Site and at other contaminated areas in the United States and throughout the world. The Environmental Sciences Section has hosted field testing of many different monitoring technologies over the past two years primarily as a result of the Integrated Demonstration Program sponsored by the Department of Energy`s Office of Technology Development. This paper provides an overview of some of the technologies that have been demonstrated at the site and briefly discusses the applicability of these techniques.

  2. Field Testing of a Portable Radiation Detector and Mapping System

    SciTech Connect

    Hofstetter, K.J.; Hayes, D.W.; Eakle, R.F.

    1998-03-01

    Researchers at the Savannah River Site (SRS) have developed a man- portable radiation detector and mapping system (RADMAPS) which integrates the accumulation of radiation information with precise ground locations. RADMAPS provides field personnel with the ability to detect, locate, and characterize nuclear material at a site or facility by analyzing the gamma or neutron spectra and correlating them with position. the man-portable field unit records gamma or neutron count rate information and its location, along with date and time, using an embedded Global Positioning System (GPS). RADMAPS is an advancement in data fusion, integrating several off-the-shelf technologies with new computer software resulting in a system that is simple to deploy and provides information useful to field personnel in an easily understandable form. Decisions on subsequent actions can be made in the field to efficiently use available field resources. The technologies employed in this system include: recording GPS, radiation detection (typically scintillation detectors), pulse height analysis, analog-to-digital converters, removable solid-state (Flash or SRAM) memory cards, Geographic Information System (GIS) software and personal computers with CD-ROM supporting digital base maps. RADMAPS includes several field deployable data acquisition systems designed to simultaneously record radiation and geographic positions. This paper summarizes the capabilities of RADMAPS and some of the results of field tests performed with the system.

  3. Geomechanical Considerations for the Deep Borehole Field Test

    NASA Astrophysics Data System (ADS)

    Park, B. Y.

    2015-12-01

    Deep borehole disposal of high-level radioactive waste is under consideration as a potential alternative to shallower mined repositories. The disposal concept consists of drilling a borehole into crystalline basement rocks to a depth of 5 km, emplacement of canisters containing solid waste in the lower 2 km, and plugging and sealing the upper 3 km of the borehole. Crystalline rocks such as granites are particularly attractive for borehole emplacement because of their low permeability and porosity at depth, and high mechanical strength to resist borehole deformation. In addition, high overburden pressures contribute to sealing of some of the fractures that provide transport pathways. We present geomechanical considerations during construction (e.g., borehole breakouts, disturbed rock zone development, and creep closure), relevant to both the smaller-diameter characterization borehole (8.5") and the larger-diameter field test borehole (17"). Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  4. Field test of a post-closure radiation monitor

    SciTech Connect

    Reed, S.E.; Christy, C.E.; Heath, R.E.

    1995-10-01

    The DOE is conducting remedial actions at many sites contaminated with radioactive materials. After closure of these sites, long-term subsurface monitoring is typically required by law. This monitoring is generally labor intensive and expensive using conventional sampling and analysis techniques. The U.S. Department of Energy`s Morgantown Energy Technology Center (METC) has contracted with Babcock and Wilcox to develop a Long-Term Post-Closure Radiation Monitoring System (LPRMS) to reduce these monitoring costs. The system designed in Phase I of this development program monitors gamma radiation using a subsurface cesium iodide scintillator coupled to above-ground detection electronics using optical waveguide. The radiation probe can be installed to depths up to 50 meters using cone penetrometer techniques, and requires no downhole electrical power. Multiplexing, data logging and analysis are performed at a central location. A prototype LPRMS probe was built, and B&W and FERMCO field tested this monitoring probe at the Fernald Environmental Management Project in the fall of 1994 with funding from the DOE`s Office of Technology Development (EM-50) through METC. The system was used measure soil and water with known uranium contamination levels, both in drums and in situ depths up to 3 meters. For comparison purposes measurements were also performed using a more conventional survey probe with a sodium iodide scintillator directly butt-coupled to detection electronics.

  5. Laboratory and field testing of improved geothermal rock bits

    SciTech Connect

    Hendrickson, R.R.; Jones, A.H.; Winzenried, R.W.; Maish, A.B.

    1980-07-01

    The development and testing of 222 mm (8-3/4 inch) unsealed, insert type, medium hard formation, high-temperature bits are described. The new bits were fabricated by substituting improved materials in critical bit components. These materials were selected on bases of their high temperature properties, machinability, and heat treatment response. Program objectives required that both machining and heat treating could be accomplished with existing rock bit production equipment. Two types of experimental bits were subjected to laboratory air drilling tests at 250/sup 0/C (482/sup 0/F) in cast iron. These tests indicated field testing could be conducted without danger to the hole, and that bearing wear would be substantially reduced. Six additional experimental bits, and eight conventional bits were then subjected to air drilling a 240/sup 0/C (464/sup 0/F) in Francisan Graywacke at The Geysers, CA. The materials selected improved roller wear by 200%, friction-pin wear by 150%, and lug wear by 150%. Geysers drilling performances compared directly to conventional bits indicate that in-gage drilling life was increased by 70%. All bits at The Geysers are subjected to reaming out-of-gage hole prior to drilling. Under these conditions the experimental bits showed a 30% increase in usable hole over the conventional bits. These tests demonstrated a potential well cost reduction of 4 to 8%. Savings of 12% are considered possible with drilling procedures optimized for the experimental bits.

  6. Silver disinfection in water distribution systems

    NASA Astrophysics Data System (ADS)

    Silvestry Rodriguez, Nadia

    Silver was evaluated as disinfectant to maintain water quality in water distribution system. It was used to inhibit growth of two opportunistic bacteria in planktonik form and in biofilm formation in Robbins devices with stainless steel and PVC surfaces. The results of this work show that silver is a potential secondary disinfectant to be used in water distribution systems.

  7. MUTAGENICITY OF DRINKING WATER FOLLOWING DISINFECTION

    EPA Science Inventory

    Many drinking water utilities in the USA are considering alternatives to chlorine for disinfection in order to comply with federal regulations regarding disinfection by-products. An evaluation is thus needed of the potential risks associated with the use of alternative disinfecta...

  8. 40 CFR 141.72 - Disinfection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Disinfection. 141.72 Section 141.72 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL... for Giardia lamblia cysts and viruses. If a system uses a disinfectant other than chlorine, the...

  9. 40 CFR 141.72 - Disinfection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Disinfection. 141.72 Section 141.72 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL... for Giardia lamblia cysts and viruses. If a system uses a disinfectant other than chlorine, the...

  10. 40 CFR 141.72 - Disinfection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for Giardia lamblia cysts and viruses. If a system uses a disinfectant other than chlorine, the system...) The residual disinfectant concentration in the distribution system, measured as total chlorine, combined chlorine, or chlorine dioxide, as specified in § 141.74 (a)(2) and (b)(6), cannot be...

  11. Interaction of disinfectant residues on cleanroom substrates.

    PubMed

    Kaiser, H; Klein, D; Kopis, E; Leblanc, D; McDonnell, G; Tirey, J F

    1999-01-01

    This study will determine the levels of disinfectant residues on stainless steel surfaces after simulated manual cleaning activities. Additionally, this study will determine if chemical interactions between different chemical agents, representative of commonly used cleanroom disinfectant technologies, subsequently applied to the same surfaces exist, and to what degree these interactions impact sporicidal performance of an oxidizing biocide against Bacillus subtilis.

  12. Disinfection of Bacillus spores with acidified nitrite.

    PubMed

    Szabo, Jeffrey G; Adcock, Noreen J; Rice, Eugene W

    2014-10-01

    Disinfecting water generated from a bioterrorism contamination event will require large amounts of disinfectant since the volume of water flushed from a drinking water distribution system or wash water collected from a contaminated outdoor area can accumulate quickly. Commonly used disinfectants may be unavailable in the necessary amounts, so evaluation of alternative disinfectants is needed. This study focuses on disinfection of Bacillus spores in water using acidified nitrite. The effect of varying pH (2 or 3), temperature (5°C or 24°C), nitrite concentration (0.01 or 0.1M), buffer (Butterfields or Phosphate Buffered Saline, PBS) and Bacillus species (B. globigii and B. anthracis Sterne) was evaluated. B. globigii was more resistant to disinfection under all water quality conditions. Disinfection was more effective for B. globigii and B. anthracis Sterne at 0.1M nitrite, pH 2, and 24°C. Disinfection of B. anthracis Sterne was enhanced in low ionic strength Butterfields buffer compared to PBS.

  13. 40 CFR 1065.935 - Emission test sequence for field testing.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Emission test sequence for field... Systems § 1065.935 Emission test sequence for field testing. (a) Time the start of field testing as.... Start the field test within 20 min of engine shutdown. (3) If the standard-setting part requires...

  14. 40 CFR 1065.935 - Emission test sequence for field testing.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Emission test sequence for field... Systems § 1065.935 Emission test sequence for field testing. (a) Time the start of field testing as.... Start the field test within 20 min of engine shutdown. (3) If the standard-setting part requires...

  15. 40 CFR 1065.935 - Emission test sequence for field testing.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Emission test sequence for field... Systems § 1065.935 Emission test sequence for field testing. (a) Time the start of field testing as.... Start the field test within 20 min of engine shutdown. (3) If the standard-setting part requires...

  16. 40 CFR 1065.935 - Emission test sequence for field testing.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Emission test sequence for field... Systems § 1065.935 Emission test sequence for field testing. (a) Time the start of field testing as.... Start the field test within 20 min of engine shutdown. (3) If the standard-setting part requires...

  17. 76 FR 3075 - Availability of an Environmental Assessment for Field Testing Feline Leukemia Vaccine, Live...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-19

    ... Feline Leukemia Vaccine, Live Canarypox Vector AGENCY: Animal and Plant Health Inspection Service, USDA... testing, and then to field test, an unlicensed Feline Leukemia Vaccine, Live Canarypox Vector. The... field testing of this vaccine, examines the potential effects that field testing this veterinary...

  18. Photovoltaic powered ultraviolet and visible light-emitting diodes for sustainable point-of-use disinfection of drinking waters.

    PubMed

    Lui, Gough Yumu; Roser, David; Corkish, Richard; Ashbolt, Nicholas; Jagals, Paul; Stuetz, Richard

    2014-09-15

    For many decades, populations in rural and remote developing regions will be unable to access centralised piped potable water supplies, and indeed, decentralised options may be more sustainable. Accordingly, improved household point-of-use (POU) disinfection technologies are urgently needed. Compared to alternatives, ultraviolet (UV) light disinfection is very attractive because of its efficacy against all pathogen groups and minimal operational consumables. Though mercury arc lamp technology is very efficient, it requires frequent lamp replacement, involves a toxic heavy metal, and their quartz envelopes and sleeves are expensive, fragile and require regular cleaning. An emerging alternative is semiconductor-based units where UV light emitting diodes (UV-LEDs) are powered by photovoltaics (PV). Our review charts the development of these two technologies, their current status, and challenges to their integration and POU application. It explores the themes of UV-C-LEDs, non-UV-C LED technology (e.g. UV-A, visible light, Advanced Oxidation), PV power supplies, PV/LED integration and POU suitability. While UV-C LED technology should mature in the next 10 years, research is also needed to address other unresolved barriers to in situ application as well as emerging research opportunities especially UV-A, photocatalyst/photosensitiser use and pulsed emission options. PMID:24946032

  19. Photovoltaic powered ultraviolet and visible light-emitting diodes for sustainable point-of-use disinfection of drinking waters.

    PubMed

    Lui, Gough Yumu; Roser, David; Corkish, Richard; Ashbolt, Nicholas; Jagals, Paul; Stuetz, Richard

    2014-09-15

    For many decades, populations in rural and remote developing regions will be unable to access centralised piped potable water supplies, and indeed, decentralised options may be more sustainable. Accordingly, improved household point-of-use (POU) disinfection technologies are urgently needed. Compared to alternatives, ultraviolet (UV) light disinfection is very attractive because of its efficacy against all pathogen groups and minimal operational consumables. Though mercury arc lamp technology is very efficient, it requires frequent lamp replacement, involves a toxic heavy metal, and their quartz envelopes and sleeves are expensive, fragile and require regular cleaning. An emerging alternative is semiconductor-based units where UV light emitting diodes (UV-LEDs) are powered by photovoltaics (PV). Our review charts the development of these two technologies, their current status, and challenges to their integration and POU application. It explores the themes of UV-C-LEDs, non-UV-C LED technology (e.g. UV-A, visible light, Advanced Oxidation), PV power supplies, PV/LED integration and POU suitability. While UV-C LED technology should mature in the next 10 years, research is also needed to address other unresolved barriers to in situ application as well as emerging research opportunities especially UV-A, photocatalyst/photosensitiser use and pulsed emission options.

  20. Sepsis, parenteral vaccination and skin disinfection

    PubMed Central

    Cook, Ian F.

    2016-01-01

    ASBSTRACT Disinfection should be required for all skin penetrative procedures including parenteral administration of vaccines. This review analyses medically attended infectious events following parenteral vaccination in terms of their microbiological aetiology and pathogenesis. Like ‘clean’ surgical site infections, the major pathogens responsible for these events were Staphylococcal species, implicating endogenous con-tamination as a significant source of infection. As 70% isopropyl alcohol swabbing has been shown to effectively disinfect the skin, it would be medico-legally difficult to defend a case of sepsis with the omission of skin disinfection unless the very low risk of this event was adequately explained to the patient and documented prior to vaccination. There was a significant cost-benefit for skin disinfection and cellulitis. Skin disinfection in the context of parenteral vaccination represents a new paradigm of medical practice; the use of a low cost intervention to prevent an event of very low prevalence but of significant cost. PMID:27295449

  1. Formation of disinfection by-products in the ultraviolet/chlorine advanced oxidation process.

    PubMed

    Wang, Ding; Bolton, James R; Andrews, Susan A; Hofmann, Ron

    2015-06-15

    Disinfection by-product (DBP) formation may be a concern when applying ultraviolet light and free chlorine (UV/chlorine) as an advanced oxidation process (AOP) for drinking water treatment, due to typically large chlorine doses (e.g. 5-10 mg L(-1) as free chlorine). A potential mitigating factor is the low chlorine contact times for this AOP treatment (e.g. seconds). Full-scale and pilot-scale test results showed minimal trihalomethane (THM) and haloacetic acid (HAA) formation during UV/chlorine treatment, while dichloroacetonitrile (DCAN) and bromochloroacetonitrile (BCAN) were produced rapidly. Adsorbable organic halide (AOX) formation was significant when applying the UV/chlorine process in water that had not been previously chlorinated, while little additional formation was observed in prechlorinated water. Chlorine photolysis led to chlorate and bromate formation, equivalent to approximately 2-17% and 0.01-0.05% of the photolyzed chlorine, respectively. No perchlorate or chlorite formation was observed. During simulated secondary disinfection of AOP-treated water, DBP formation potential for THMs, HAAs, HANs, and AOX was observed to increase approximately to the same extent as was observed for pretreatment using the more common AOP of UV combined with hydrogen peroxide (UV/H2O2).

  2. Field testing plan for unsaturated zone monitoring and field studies

    SciTech Connect

    Young, M.H.; Wierenga, P.J.; Warrick, A.W.

    1996-10-01

    The University of Arizona, in cooperation with the Bureau of Economic Geology at The University of Texas at Austin, and Stephens and Associates in Albuquerque, New Mexico has developed a field testing plan for evaluating subsurface monitoring systems. The U.S. Nuclear Regulatory Commission has requested development of these testing plans for low-level radioactive waste disposal sites (LLW) and for monitoring at decommissioned facilities designated under the {open_quotes}Site Decommissioning Management Plan{close_quotes} (SDMP). The tests are conducted on a 50 m by 50 m plot on the University of Arizona`s Maricopa Agricultural Center. Within the 50 m by 50 m plot one finds: (1) an instrumented buried trench, (2) monitoring islands similar to those proposed for the Ward Valley, California LLW Facility, (3) deep borehole monitoring sites, (4) gaseous transport monitoring, and (5) locations for testing non-invasive geophysical measurement techniques. The various subplot areas are instrumented with commercially available instruments such as neutron probes, time domain reflectometry probes, tensiometers, psychrometers, heat dissipation sensors, thermocouples, solution samplers, and cross-hole geophysics electrodes. Measurement depths vary from ground surface to 15 m. The data from the controlled flow and transport experiments, conducted over the plot, will be used to develop an integrated approach to long-term monitoring of the vadose zone at waste disposal sites. The data will also be used to test field-scale flow and transport models. This report describes in detail the design of the experiment and the methodology proposed for evaluating the data.

  3. Comparison of two field tests to estimate maximum aerobic speed.

    PubMed

    Berthoin, S; Gerbeaux, M; Turpin, E; Guerrin, F; Lensel-Corbeil, G; Vandendorpe, F

    1994-08-01

    The measurement of maximal aerobic speed (MAS) and the prediction of maximal oxygen uptake (VO2 max) by means of field tests were carried out on 17 students studying physical education. The subjects underwent a continuous multi-stage track test (Léger and Boucher, 1980), shuttle test (Léger et al., 1984) and VO2 max measurement on a treadmill. The VO2 max values estimated using the track test (56.8 +/- 5.8 ml kg-1 min-1) were not significantly different from the values measured in the treadmill test (56.8 +/- 7.1 ml kg-1 min-1), but were higher than those estimated using the shuttle test (51.1 +/- 5.9 ml kg-1 min-1). The maximal nature of the tests was checked by measurement of heart rate and lactate concentration, taken within 2 min post-test. The means of the MAS observed in the track test (15.8 +/- 1.9 km h-1) and in the treadmill test (15.9 +/- 2.6 km h-1) were not significantly different (P > 0.10). The mean of the shuttle test MAS (13.1 +/- 1 km h-1) was significantly lower (P < 0.01) than those of the other tests. However, the MAS of the shuttle test and track test are linked. The equation for linear regression between MAS values in these two tests is MAStrack = 1.81 x MASshuttle -7.86 (r = 0.91), allowing estimation of one of these MAS values when the other is known. Thus these values may be used within diversified training.

  4. Field Testing GEOICE: A Next-Generation Polar Seismometer

    NASA Astrophysics Data System (ADS)

    Beaudoin, B. C.; Winberry, J. P.; Huerta, A. D.; Chung, P.; Parker, T.; Anderson, K. R.; Bilek, S. L.; Carpenter, P.

    2015-12-01

    We report on the development of a new NSF MRI-community supported seismic observatory designed for studies in ice-covered regions - the Geophysical Earth Observatory for Ice Covered Environs (GEOICE). This project is motivated by the need to densify and optimize the collection of high-quality seismic data relevant to key solid Earth and cryosphere science questions. The GEOICE instruments and their power and other ancillary systems are being designed to require minimal installation time and logistical load (i.e., size and weight), while maximizing ease-of-use in the field. The system is capable of advanced data handling and telemetry while being able to withstand conditions associated with icy environments, including cold/wet conditions and high-latitude solar limitations. The instrument capability will include a hybrid seismograph pool of broadband and intermediate elements for observation of both long-period signals (e.g, long-period surface waves and slow sources) and intermediate-to-short-period signals (e.g., teleseismic body waves, local seismicity, and impulsive or extended glaciogenic signals).Key features will include a design that integrates the seismometer and digitizer into a single, environmentally and mechanically robust housing; very low power requirements (~1 watt) for the intermediate-band systems; and advanced power systems that optimize battery capacity and operational limits. The envisioned ~100 element GEOICE instruments will nearly double the current polar inventory of stations and will be maintained and supported at the IRIS PASSCAL Instrument Center to ensure full and flexible peer-reviewed community use. Prototype instruments are currently deployed in Antarctica and Alaska, with a larger Antarctic deployment planned for the 2015-2016 season. The results of these field tests will help to refine instrumentation design and lead to the production of robust and capable next-generation seismic sensors.

  5. Advanced Rooftop Control (ARC) Retrofit: Field-Test Results

    SciTech Connect

    Wang, Weimin; Katipamula, Srinivas; Ngo, Hung; Underhill, Ronald M.; Taasevigen, Danny J.; Lutes, Robert G.

    2013-07-31

    The multi-year research study was initiated to find solutions to improve packaged equipment operating efficiency in the field. Pacific Northwest National Laboratory (PNNL), with funding from the U.S. Department of Energy’s (DOE’s) Building Technologies Office (BTO) and Bonneville Power Administration (BPA) conducted this research, development and demonstration (RD&D) study. Packaged equipment with constant speed supply fans is designed to provide ventilation at the design rate at all times when the fan is operating as required by building code. Although there are a number of hours during the day when a building may not be fully occupied or the need for ventilation is lower than designed, the ventilation rate cannot be adjusted easily with a constant speed fan. Therefore, modulating the supply fan in conjunction with demand controlled ventilation (DCV) will not only reduce the coil energy but also reduce the fan energy. The objective of this multi-year research, development and demonstration project was to determine the magnitude of energy savings achievable by retrofitting existing packaged rooftop air conditioners with advanced control strategies not ordinarily used for packaged units. First, through detailed simulation analysis, it was shown that significant energy (between 24% and 35%) and cost savings (38%) from fan, cooling and heating energy consumption could be realized when packaged air conditioning units with gas furnaces are retrofitted with advanced control packages (combining multi-speed fan control, integrated economizer controls and DCV). The simulation analysis also showed significant savings for heat pumps (between 20% and 60%). The simulation analysis was followed by an extensive field test of a retrofittable advanced rooftop unit (RTU) controller.

  6. Field tests of acoustic telemetry for a portable coastal observatory

    USGS Publications Warehouse

    Martini, M.; Butman, B.; Ware, J.; Frye, D.

    2006-01-01

    Long-term field tests of a low-cost acoustic telemetry system were carried out at two sites in Massachusetts Bay. At each site, an acoustic Doppler current profiler mounted on a bottom tripod was fitted with an acoustic modem to transmit data to a surface buoy; electronics mounted on the buoy relayed these data to shore via radio modem. The mooring at one site (24 m water depth) was custom-designed for the telemetry application, with a custom designed small buoy, a flexible electro-mechanical buoy to mooring joint using a molded chain connection to the buoy, quick-release electro-mechanical couplings, and dual hydrophones suspended 7 m above the bottom. The surface buoy at the second site (33 m water depth) was a U.S. Coast Guard (USCG) channel buoy fitted with telemetry electronics and clamps to hold the hydrophones. The telemetry was tested in several configurations for a period of about four years. The custom-designed buoy and mooring provided nearly error-free data transmission through the acoustic link under a variety of oceanographic conditions for 261 days at the 24 m site. The electro mechanical joint, cables and couplings required minimal servicing and were very reliable, lasting 862 days deployed before needing repairs. The acoustic communication results from the USCG buoy were poor, apparently due to the hard cobble bottom, noise from the all-steel buoy, and failure of the hydrophone assembly. Access to the USCG buoy at sea required ideal weather. ??2006 IEEE.

  7. Field testing advanced geothermal turbodrill (AGT). Phase 1 final report

    SciTech Connect

    Maurer, W.C.; Cohen, J.H.

    1999-06-01

    Maurer Engineering developed special high-temperature geothermal turbodrills for LANL in the 1970s to overcome motor temperature limitations. These turbodrills were used to drill the directional portions of LANL`s Hot Dry Rock Geothermal Wells at Fenton Hill, New Mexico. The Hot Dry Rock concept is to drill parallel inclined wells (35-degree inclination), hydraulically fracture between these wells, and then circulate cold water down one well and through the fractures and produce hot water out of the second well. At the time LANL drilled the Fenton Hill wells, the LANL turbodrill was the only motor in the world that would drill at the high temperatures encountered in these wells. It was difficult to operate the turbodrills continuously at low speed due to the low torque output of the LANL turbodrills. The turbodrills would stall frequently and could only be restarted by lifting the bit off bottom. This allowed the bit to rotate at very high speeds, and as a result, there was excessive wear in the bearings and on the gauge of insert roller bits due to these high rotary speeds. In 1998, Maurer Engineering developed an Advanced Geothermal Turbodrill (AGT) for the National Advanced Drilling and Excavation Technology (NADET) at MIT by adding a planetary speed reducer to the LANL turbodrill to increase its torque and reduce its rotary speed. Drilling tests were conducted with the AGT using 12 1/2-inch insert roller bits in Texas Pink Granite. The drilling tests were very successful, with the AGT drilling 94 ft/hr in Texas Pink Granite compared to 45 ft/hr with the LANL turbodrill and 42 ft/hr with a rotary drill. Field tests are currently being planned in Mexico and in geothermal wells in California to demonstrate the ability of the AGT to increase drilling rates and reduce drilling costs.

  8. Site Characterization for a Deep Borehole Field Test

    NASA Astrophysics Data System (ADS)

    Kuhlman, K. L.; Hardin, E. L.; Freeze, G. A.; Sassani, D.; Brady, P. V.

    2015-12-01

    The US Department of Energy Office of Nuclear Energy is at the beginning of 5-year Deep Borehole Field Test (DBFT) to investigate the feasibility of constructing and characterizing two boreholes in crystalline basement rock to a depth of 5 km (16,400 ft). The concept of deep borehole disposal for radioactive waste has some advantages over mined repositories, including incremental construction and loading, the enhanced natural barriers provided by deep continental crystalline basement, and reduced site characterization. Site characterization efforts need to determine an eligible site that does not have the following disqualifying characteristics: greater than 2 km to crystalline basement, upward vertical fluid potential gradients, presence of economically exploitable natural resources, presence of high permeability connection to the shallow subsurface, and significant probability of future seismic or volcanic activity. Site characterization activities for the DBFT will include geomechanical (i.e., rock in situ stress state, and fluid pressure), geological (i.e., rock and fracture infill lithology), hydrological (i.e., quantity of fluid, fluid convection properties, and solute transport mechanisms), and geochemical (i.e., rock-water interaction and natural tracers) aspects. Both direct (i.e., sampling and in situ testing) and indirect (i.e., borehole geophysical) methods are planned for efficient and effective characterization of these site aspects and physical processes. Borehole-based characterization will be used to determine the variability of system state (i.e., stress, pressure, temperature, and chemistry) with depth, and interpretation of material and system parameters relevant to numerical site simulation. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE

  9. Drinking water biofilms on copper and stainless steel exhibit specific molecular responses towards different disinfection regimes at waterworks.

    PubMed

    Jungfer, Christina; Friedrich, Frank; Varela Villarreal, Jessica; Brändle, Katharina; Gross, Hans-Jürgen; Obst, Ursula; Schwartz, Thomas

    2013-09-01

    Biofilms growing on copper and stainless steel substrata in natural drinking water were investigated. A modular pilot-scale distribution facility was installed at four waterworks using different raw waters and disinfection regimes. Three-month-old biofilms were analysed using molecular biology and microscopy methods. High total cell numbers, low counts of actively respiring cells and low numbers of cultivable bacteria indicated the high abundance of viable but not cultivable bacteria in the biofilms. The expression of the recA SOS responsive gene was detected and underlined the presence of transcriptionally active bacteria within the biofilms. This effect was most evident after UV disinfection, UV oxidation and UV disinfection with increased turbidity at waterworks compared to chemically treated and non-disinfected systems. Furthermore, live/dead staining techniques and environmental scanning electron microscopy imaging revealed the presence of living and intact bacteria in biofilms on copper substrata. Cluster analyses of DGGE profiles demonstrated differences in the composition of biofilms on copper and steel materials.

  10. Comparison of UVB and UVC irradiation disinfection efficacies on Pseudomonas Aeruginosa (P. aeruginosa) biofilm

    NASA Astrophysics Data System (ADS)

    Argyraki, A.; Markvart, M.; Nielsen, Anne; Bjarnsholt, T.; Bjørndal, L.; Petersen, P. M.

    2016-04-01

    Disinfection routines are important in all clinical applications. The uprising problem of antibiotic resistance has driven major research efforts towards alternative disinfection approaches, involving light-based solutions. Pseudomonas aeruginosa (P. aeruginosa) is a common bacterium that can cause skin, soft tissue, lungs, kidney and urinary tract infections. Moreover, it can be found on and in medical equipment causing often cross infections in hospitals. The objective of this study was to test the efficiency, of two different light-based disinfection treatments, namely UVB and UVC irradiation, on P. aeruginosa biofilms at different growth stages. In our experiments a new type of UV light emitting diodes (LEDs) were used to deliver UV irradiation on the biofilms, in the UVB (296nm) and UVC (266nm) region. The killing rate was studied as a function of dose for 24h grown biofilms. The dose was ramped from 72J/m2 to 10000J/m2. It was shown that UVB irradiation was more effective than UVC irradiation in inactivating P. aeruginosa biofilms. No colony forming units (CFU) were observed for the UVB treated biofilms when the dose was 10000 J/m2 (CFU in control sample: 7.5 x 104). UVB irradiation at a dose of 20000J/m2 on mature biofilms (72h grown) resulted in a 3.9 log killing efficacy. The fact that the wavelength of 296nm exists in daylight and has such disinfection ability on biofilms gives new perspectives for applications within disinfection at hospitals.

  11. Particle effects on ultraviolet disinfection of coliform bacteria in recycled water.

    PubMed

    Jolis, D; Lam, C; Pitt, P

    2001-01-01

    Pilot- and bench-scale coliform inactivation tests with UV irradiation were used to show how suspended solids remaining in filtered secondary effluent affect the efficiency of the UV disinfection process. Observed kinetic inactivation rates decreased with increasing suspended particle sizes of 7 microm or larger present in tertiary effluent. First-order inactivation rates estimated from collimated beam dose-response curves for discrete ranges of UV doses were substantially different, which should caution researchers not to compare inactivation data obtained with largely dissimilar UV doses or suspended particle distributions. A dose of approximately 800 J/m2 was identified as the minimum dose that will consistently meet the California wastewater reclamation coliform criterion when applied to in-line filtration effluent.

  12. EFFICACY OF NOVEL WATER DISINFECTION TECHNIQUES IN HORTICULTURAL NUTRIENT RECYCLING.

    PubMed

    Heungens, K; Clierinck, M; Inghelbrecht, S; Vissers, M

    2015-01-01

    Hydroponic systems used for growing potted ornamentals in greenhouses are commonly ebb-and-flow irrigation systems. The drainage water is usually recycled to save water and nutrients. To avoid the spread of pathogens in these closed irrigation systems, disinfection of the recycled water is standard practice. Growers can use slow sand filtration or UV-radiation techniques, but these methods are often either not sulted for specific problems or they require an excessively large investment. The objective of this study was to test less expensive but effective alternative disinfection systems. The efficacy of five disinfection systems against fungi and oomycetes was determined: Aqua-Hort (based on Cu-ions), Reciclean (performic acid), D1-OX Forte (CIO2), ECA (electrochemically activated water = anodic oxidation: hypochlorite and free radicals) and Newtec (also anodic oxidation). These five systems and a no-sterilization control were integrated in small closed ebb-and-flow circuits with nutrient solution reservoirs of 400 L each. Activity against Fusarium was excellent with ECA, good with Newtec and DI-OX Forte, moderate with high doses of Reciclean (250 ppm H2O2 and poor with the Aqua-Hort. There was no Pythium in the ECA and Newtec systems, while still so in the Aqua-Hort system, even at high doses (up to 7 ppm Cu++). Although the Reciclean (up to 100 ppm H2O2) and Aqua-Hort systems did not perform well against the pathogens, they did very well against algae; especially Reciclean was also useful against duckweed in water and liverwort on soil substrates. Concentrations of total Cl were elevated in water, substrate and plants after treatments with ECA and Newtec; other accumulations were Cu (Aqua-Hort), Na and SO4 (DI-OX Forte). However, only on a limited number of plant species these accumulations produced phytotoxic effects.

  13. Drowning in disinfection byproducts? Assessing swimming pool water.

    PubMed

    Zwiener, Christian; Richardson, Susan D; DeMarini, David M; De Marini, David M; Grummt, Tamara; Glauner, Thomas; Frimmel, Fritz H

    2007-01-15

    Disinfection is mandatory for swimming pools: public pools are usually disinfected by gaseous chlorine or sodium hypochlorite and cartridge filters; home pools typically use stabilized chlorine. These methods produce a variety of disinfection byproducts (DBPs), such as trihalomethanes (THMs), which are regulated carcinogenic DBPs in drinking water that have been detected in the blood and breath of swimmers and of nonswimmers at indoor pools. Also produced are halogenated acetic acids (HAAs) and haloketones, which irritate the eyes, skin, and mucous membranes; trichloramine, which is linked with swimming-pool-associated asthma; and halogenated derivatives of UV sun screens, some of which show endocrine effects. Precursors of DBPs include human body substances, chemicals used in cosmetics and sun screens, and natural organic matter. Analytical research has focused also on the identification of an additional portion of unknown DBPs using gas chromatography (GC)/mass spectrometry (MS) and liquid chromatography (LC)/MS/MS with derivatization. Children swimmers have an increased risk of developing asthma and infections of the respiratory tract and ear. A 1.6-2.0-fold increased risk for bladder cancer has been associated with swimming or showering/bathing with chlorinated water. Bladder cancer risk from THM exposure (all routes combined) was greatest among those with the GSTT1-1 gene. This suggests a mechanism involving distribution of THMs to the bladder by dermal/inhalation exposure and activation there by GSTT1-1 to mutagens. DBPs may be reduced by engineering and behavioral means, such as applying new oxidation and filtration methods, reducing bromide and iodide in the source water, increasing air circulation in indoor pools, and assuring the cleanliness of swimmers. The positive health effects gained by swimming can be increased by reducing the potential adverse health risks. PMID:17310693

  14. EFFICACY OF NOVEL WATER DISINFECTION TECHNIQUES IN HORTICULTURAL NUTRIENT RECYCLING.

    PubMed

    Heungens, K; Clierinck, M; Inghelbrecht, S; Vissers, M

    2015-01-01

    Hydroponic systems used for growing potted ornamentals in greenhouses are commonly ebb-and-flow irrigation systems. The drainage water is usually recycled to save water and nutrients. To avoid the spread of pathogens in these closed irrigation systems, disinfection of the recycled water is standard practice. Growers can use slow sand filtration or UV-radiation techniques, but these methods are often either not sulted for specific problems or they require an excessively large investment. The objective of this study was to test less expensive but effective alternative disinfection systems. The efficacy of five disinfection systems against fungi and oomycetes was determined: Aqua-Hort (based on Cu-ions), Reciclean (performic acid), D1-OX Forte (CIO2), ECA (electrochemically activated water = anodic oxidation: hypochlorite and free radicals) and Newtec (also anodic oxidation). These five systems and a no-sterilization control were integrated in small closed ebb-and-flow circuits with nutrient solution reservoirs of 400 L each. Activity against Fusarium was excellent with ECA, good with Newtec and DI-OX Forte, moderate with high doses of Reciclean (250 ppm H2O2 and poor with the Aqua-Hort. There was no Pythium in the ECA and Newtec systems, while still so in the Aqua-Hort system, even at high doses (up to 7 ppm Cu++). Although the Reciclean (up to 100 ppm H2O2) and Aqua-Hort systems did not perform well against the pathogens, they did very well against algae; especially Reciclean was also useful against duckweed in water and liverwort on soil substrates. Concentrations of total Cl were elevated in water, substrate and plants after treatments with ECA and Newtec; other accumulations were Cu (Aqua-Hort), Na and SO4 (DI-OX Forte). However, only on a limited number of plant species these accumulations produced phytotoxic effects. PMID:27141749

  15. Quaternary Ammonium Disinfectant Issues Encountered in an Environmental Services Department.

    PubMed

    Boyce, John M; Sullivan, Linda; Booker, Arica; Baker, James

    2016-03-01

    We identified several factors affecting the use of quaternary ammonium-based (Quat) disinfectant in our facility. Microfiber wipers, cotton towels, and 1 of 2 types of disposable wipes soaked in a Quat disinfectant revealed significant binding of the disinfectant. Concentrations of Quat delivered by automated disinfectant dispensers varied widely.

  16. Disinfecting activities of non-peroxide soft contact lens cold disinfection solutions.

    PubMed

    Shih, K L; Raad, M K; Hu, J C; Gresh, W J; Jiries, S I; Caldwell, L J; Bergamini, M V

    1991-07-01

    The antimicrobial activities of three non-peroxide soft contact lens chemical disinfection systems--ReNu Multi-Purpose Solution (0.00005% polyaminopropyl biguanide), Opti-Soft Disinfecting Solution (0.001% polyquaternium-1), and Opti-Free Rinsing, Disinfecting & Storage Solution (0.001% polyquaternium-1)--were compared to Soft Mate Disinfecting Solution (0.005% chlorhexidine digluconate). Each product was separately inoculated with each of five microorganisms at approximately 10(6) microorganisms per mL. All of the solutions demonstrated excellent disinfecting activity against Pseudomonas aeruginosa and Staphylococcus epidermidis, with complete disinfection occurring within 4 hours. Only Soft Mate disinfected Serratia marcescens within 4 hours. ReNu reduced the microorganisms to 10-100 cells/mL and Opti-Soft and Opti-Free reduced the number to 10(2)-10(3) cells/mL. For the fungal species, Soft Mate showed excellent activity against Candida albicans (disinfection in 4 hours) and reduced Aspergillus fumigatus to 10(3) spores/mL in 4 hours. After 4 hours ReNu, Opti-Soft, and Opti-Free had reduced C. albicans only slightly, to 10(5) cells/mL and displayed virtually no disinfecting activity against A. fumigatus. For these newer chemical disinfection systems, diligent cleaning and rinsing of the soft contact lenses are the most important steps in the patient care regimen.

  17. Optimization of fixed titanium dioxide film on PET bottles and visual indicator for water disinfection

    NASA Astrophysics Data System (ADS)

    Heredia-Munoz, Manuel Antonio

    Water is perhaps the most important resource that sustains human life. According to the World Health Organization (WHO), almost two billion people do not have access to the required water that is needed to satisfy their daily needs and one billion do not have access to clean sources of water for consumption, most of them living in isolated and poor areas around the globe. Poor quality water increases the risk of cholera, typhoid fever and dysentery, and other water-borne illness making this problem a real crisis that humankind is facing. Several water disinfection technologies have been proposed as solutions for this problem. Solar water disinfection using TiO2 coated PET bottles was the alternative that is studied in this work. This technology does not only inactivate bacteria but also disintegrates organic chemicals that can be present in water. The objectives of this work address the optimization of the TiO 2 coated PET bottles technologies. The improvement on the bottle coating process, using two coats of 10% W/V of TiO2 in a solution of vinegar and sodium bicarbonate to form the TiO2 film, the use of a different indigo carmine (1.25 X 10-1mg/pill) concentration in the pill indicator of contamination, the increase of the disinfection rate through shaking the bottles, degradation under intermittent UV radiation and the effect of bottle size on photocatalytic water disinfection were among the most important findings. A new mathematical model that describes better photocatalytic water disinfection in TiO2 coated bottles and simulates water disinfection under different working conditions was another important achievement. These results can now be used to design a strategy for disseminating this technology in areas where it is required and, in that way, generate the greatest positive impact on the people needing safe drinking water.

  18. Algal biomass production and wastewater treatment in high rate algal ponds receiving disinfected effluent.

    PubMed

    Santiago, Aníbal Fonseca; Calijuri, Maria Lucia; Assemany, Paula Peixoto; Calijuri, Maria do Carmo; dos Reis, Alberto José Delgado

    2013-01-01

    Algal biomass production associated with wastewater is usually carried out in high rate algal ponds (HRAPs), which are concomitantly used in the treatment of such effluent. However, most types of wastewater have high levels of bacteria that can inhibit the growth of algal biomass by competing for space and nutrients. The objective of this study was to assess the influence of ultraviolet (UV) pre-disinfection on the performance of HRAPs used for wastewater treatment and algal biomass production. Two HRAPs were tested: one received effluent from an upflow anaerobic sludge blanket (UASB) reactor- HRAP -and the second received UASB effluent pre-disinfected by UV radiation-(UV)HRAP. Physical, chemical and microbiological parameters were monitored, as well as algal biomass productivity and daily pH and dissolved oxygen (DO) variation. The (UV)HRAP presented highest DO and pH values, as well as greater percentage of chlorophyll a in the biomass, which indicates greater algal biomass productivity. The average percentages of chlorophyll a found in the biomass obtained from the HRAP and the (UV)HRAP were 0.95 +/- 0.65% and 1.58 +/- 0.65%, respectively. However, total biomass productivity was greater in the HRAP (11.4 gVSSm(-2) day(-1)) compared with the (UV)HRAP (9.3 gVSSm(-2) day(-1)). Mean pH values were 7.7 +/- 0.7 in the HRAP and 8.1 +/- 1.0 in the (UV)HRAP, and mean values of DO percent saturation were 87 +/- 26% and 112 +/- 31% for the HRAP and the (UV)HRAP, respectively. Despite these differences, removal efficiencies of organic carbon, chemical oxygen demand, ammoniacal nitrogen and soluble phosphorus were statistically equal at the 5% significance level.

  19. Results from laboratory and field testing of nitrate measuring spectrophotometers

    USGS Publications Warehouse

    Snazelle, Teri T.

    2015-01-01

    In Phase II, the analyzers were deployed in field conditions at three diferent USGS sites. The measured nitrate concentrations were compared to discrete (reference) samples analyzed by the Direct UV method on a Shimadzu UV1800 bench top spectrophotometer, and by the National Environmental Methods Index (NEMI) method I-2548-11 at the USGS National Water Quality Laboratory. The first deployment at USGS site 0249620 on the East Pearl River in Hancock County, Mississippi, tested the ability of the TriOs ProPs (10-mm path length), Hach NITRATAX (5 mm), Satlantic SUNA (10 mm), and the S::CAN Spectro::lyser (5 mm) to accurately measure low-level (less than 2 mg-N/L) nitrate concentrations while observing the effect turbidity and colored dissolved organic matter (CDOM) would have on the analyzers' measurements. The second deployment at USGS site 01389005 Passaic River below Pompton River at Two Bridges, New Jersey, tested the analyzer's accuracy in mid-level (2-8 mg-N/L) nitrate concentrations. This site provided the means to test the analyzers' performance in two distinct matrices—the Passaic and the Pompton Rivers. In this deployment, three instruments tested in Phase I (TriOS, Hach, and SUNA) were deployed with the S::CAN Spectro::lyser (35 mm) already placed by the New Jersey Water Science Center (WSC). The third deployment at USGS site 05579610 Kickapoo Creek at 2100E Road near Bloomington, Illinois, tested the ability of the analyzers to measure high nitrate concentrations (greater than 8 mg-N/L) in turbid waters. For Kickapoo Creek, the HIF provided the TriOS (10 mm) and S::CAN (5 mm) from Phase I, and a SUNA V2 (5 mm) to be deployed adjacent to the Illinois WSC-owned Hach (2 mm). A total of 40 discrete samples were collected from the three deployment sites and analyzed. The nitrate concentration of the samples ranged from 0.3–22.2 mg-N/L. The average absolute difference between the TriOS measurements and discrete samples was 0.46 mg-N/L. For the combined data

  20. UV inactivation of pathogenic and indicator microorganisms

    SciTech Connect

    Chang, J.C.; Ossoff, S.F.; Lobe, D.C.; Dorfman, M.H.; Dumais, C.M.; Qualls, R.G.; Johnson, J.D.

    1985-06-01

    Survival was measured as a function of the dose of germicidal UV light for the bacteria Escherichia coli, Salmonella typhi, Shigella sonnei, Streptococcus faecalis, Staphylococcus aureus, and Bacillus subtilis spores, the enteric viruses poliovirus type 1 and simian rotavirus SA11, the cysts of the protozoan Acanthamoeba castellanii, as well as for total coliforms and standard plate count microorganisms from secondary effluent. The doses of UV light necessary for a 99.9% inactivation of the cultured vegetative bacteria, total coliforms, and standard plate count microorganisms were comparable. However, the viruses, the bacterial spores, and the amoebic cysts required about 3 to 4 times, 9 times, and 15 times, respectively, the dose required for E. coli. These ratios covered a narrower relative dose range than that previously reported for chlorine disinfection of E. coli, viruses, spores, and cysts.

  1. UV inactivation of pathogenic and indicator microorganisms.

    PubMed Central

    Chang, J C; Ossoff, S F; Lobe, D C; Dorfman, M H; Dumais, C M; Qualls, R G; Johnson, J D

    1985-01-01

    Survival was measured as a function of the dose of germicidal UV light for the bacteria Escherichia coli, Salmonella typhi, Shigella sonnei, Streptococcus faecalis, Staphylococcus aureus, and Bacillus subtilis spores, the enteric viruses poliovirus type 1 and simian rotavirus SA11, the cysts of the protozoan Acanthamoeba castellanii, as well as for total coliforms and standard plate count microorganisms from secondary effluent. The doses of UV light necessary for a 99.9% inactivation of the cultured vegetative bacteria, total coliforms, and standard plate count microorganisms were comparable. However, the viruses, the bacterial spores, and the amoebic cysts required about 3 to 4 times, 9 times, and 15 times, respectively, the dose required for E. coli. These ratios covered a narrower relative dose range than that previously reported for chlorine disinfection of E. coli, viruses, spores, and cysts. PMID:2990336

  2. Intermittent versus Continuous Incremental Field Tests: Are Maximal Variables Interchangeable?

    PubMed

    Carminatti, Lorival J; Possamai, Carlos A P; de Moraes, Marcelo; da Silva, Juliano F; de Lucas, Ricardo D; Dittrich, Naiandra; Guglielmo, Luiz G A

    2013-01-01

    The aim of the present study was to compare physiological responses derived from an incremental progressive field test with a constant speed test i.e. intermittent versus continuous protocol. Two progressive maximum tests (Carminatti`s test (T-CAR) and the Vameval test (T-VAM)), characterized by increasing speed were used. T-CAR is an intermittent incremental test, performed as shuttle runs; while T-VAM is a continuous incremental test performed on an athletic track. Eighteen physically active, healthy young subjects (21.9 ± 2.0 years; 76.5 ± 8.6 kg, 1.78 ± 0.08 m, 11.2 ± 5.4% body fat), volunteered for this study. Subjects performed four different maximum test sessions conducted in the field: two incremental tests and two time to exhaustion tests (TTE) at peak test velocities (PV). No significant differences were found for PV (T-CAR = 15.6 ± 1.2; T-VAM = 15.5 ± 1.3 km·h(-1)) and maximal HR (T-CAR = 195 ± 11; T- VAM = 194 ± 14 bpm). During TTE, there were no significant differences for HR (TTET-CAR and TTET-VAM = 192 ± 12 bpm). However, there was a significant difference in TTE (p = 0.04) (TTET-CAR = 379 ± 84, TTET-VAM = 338 ± 58 s) with a low correlation (r = 0.41). The blood lactate concentration measured at the end of the TTE tests, showed no significant difference (TTET-CAR = 13.2 ± 2.4 vs. TTET-VAM = 12.9 ± 2.4 mmol·l(-1)). Based on the present findings, it is suggested that the maximal variables derived from T-CAR and T-VAM can be interchangeable in the design of training programs. Key pointsT-CAR is an intermittent shuttle run test that predicts the maximal aerobic speed with accuracy, hence, test results could be interchangeable with continuous straight-line tests.T-CAR provides valid field data for evaluating aerobic fitness.In comparison with T-VAM, T-CAR may be a more favourable way to prescribe intermittent training using a shuttle-running protocol.

  3. Development of a specific anaerobic field test for aerobic gymnastics.

    PubMed

    Alves, Christiano Robles Rodrigues; Borelli, Marcello Tadeu Caetano; Paineli, Vitor de Salles; Azevedo, Rafael de Almeida; Borelli, Claudia Cristine Gomes; Lancha Junior, Antônio Herbert; Gualano, Bruno; Artioli, Guilherme Giannini

    2015-01-01

    The current investigation aimed to develop a valid specific field test to evaluate anaerobic physical performance in Aerobic Gymnastics athletes. We first designed the Specific Aerobic Gymnast Anaerobic Test (SAGAT), which included gymnastics-specific elements performed in maximal repeated sprint fashion, with a total duration of 80-90 s. In order to validate the SAGAT, three independent sub-studies were performed to evaluate the concurrent validity (Study I, n=8), the reliability (Study II, n=10) and the sensitivity (Study III, n=30) of the test in elite female athletes. In Study I, a positive correlation was shown between lower-body Wingate test and SAGAT performance (Mean power: p = 0.03, r = -0.69, CI: -0.94 to 0.03 and Peak power: p = 0.02, r = -0.72, CI: -0.95 to -0.04) and between upper-body Wingate test and SAGAT performance (Mean power: p = 0.03, r = -0.67, CI: -0.94 to 0.02 and Peak power: p = 0.03, r = -0.69, CI: -0.94 to 0.03). Additionally, plasma lactate was similarly increased in response to SAGAT (p = 0.002), lower-body Wingate Test (p = 0.021) and a simulated competition (p = 0.007). In Study II, no differences were found between the time to complete the SAGAT in repeated trials (p = 0.84; Cohen's d effect size = 0.09; ICC = 0.97, CI: 0.89 to 0.99; MDC95 = 0.12 s). Finally, in Study III the time to complete the SAGAT was significantly lower during the competition cycle when compared to the period before the preparatory cycle (p < 0.001), showing an improvement in SAGAT performance after a specific Aerobic Gymnastics training period. Taken together, these data have demonstrated that SAGAT is a specific, reliable and sensitive measurement of specific anaerobic performance in elite female Aerobic Gymnastics, presenting great potential to be largely applied in training settings. PMID:25876039

  4. Advanced Utility Mercury-Sorbent Field-Testing Program

    SciTech Connect

    Ronald Landreth

    2007-12-31

    This report summarizes the work conducted from September 1, 2003 through December 31, 2007 on the project entitled Advanced Utility Mercury-Sorbent Field-Testing Program. The project covers the testing at the Detroit Edison St. Clair Plant and the Duke Power Cliffside and Buck Stations. The St. Clair Plant used a blend of subbituminous and bituminous coal and controlled the particulate emissions by means of a cold-side ESP. The Duke Power Stations used bituminous coals and controlled their particulate emissions by means of hot-side ESPs. The testing at the Detroit Edison St. Clair Plant demonstrated that mercury sorbents could be used to achieve high mercury removal rates with low injection rates at facilities that burn subbituminous coal. A mercury removal rate of 94% was achieved at an injection rate of 3 lb/MMacf over the thirty day long-term test. Prior to this test, it was believed that the mercury in flue gas of this type would be the most difficult to capture. This is not the case. The testing at the two Duke Power Stations proved that carbon- based mercury sorbents can be used to control the mercury emissions from boilers with hot-side ESPs. It was known that plain PACs did not have any mercury capacity at elevated temperatures but that brominated B-PAC did. The mercury removal rate varies with the operation but it appears that mercury removal rates equal to or greater than 50% are achievable in facilities equipped with hot-side ESPs. As part of the program, both sorbent injection equipment and sorbent production equipment was acquired and operated. This equipment performed very well during this program. In addition, mercury instruments were acquired for this program. These instruments worked well in the flue gas at the St. Clair Plant but not as well in the flue gas at the Duke Power Stations. It is believed that the difference in the amount of oxidized mercury, more at Duke Power, was the difference in instrument performance. Much of the equipment was

  5. Field Testing of Nano-PCM Enhanced Building Envelope Components

    SciTech Connect

    Biswas, Kaushik; Childs, Phillip W; Atchley, Jerald Allen

    2013-08-01

    The U.S. Department of Energy s (DOE) Building Technologies Program s goal of developing high-performance, energy efficient buildings will require more cost-effective, durable, energy efficient building envelopes. Forty-eight percent of the residential end-use energy consumption is spent on space heating and air conditioning. Reducing envelope-generated heating and cooling loads through application of phase change material (PCM)-enhanced envelope components can facilitate maximizing the energy efficiency of buildings. Field-testing of prototype envelope components is an important step in estimating their energy benefits. An innovative phase change material (nano-PCM) was developed with PCM encapsulated with expanded graphite (interconnected) nanosheets, which is highly conducive for enhanced thermal storage and energy distribution, and is shape-stable for convenient incorporation into lightweight building components. During 2012, two test walls with cellulose cavity insulation and prototype PCM-enhanced interior wallboards were installed in a natural exposure test (NET) facility at Charleston, SC. The first test wall was divided into four sections, which were separated by wood studs and thin layers of foam insulation. Two sections contained nano-PCM-enhanced wallboards: one was a three-layer structure, in which nano-PCM was sandwiched between two gypsum boards, and the other one had PCM dispersed homogeneously throughout graphite nanosheets-enhanced gypsum board. The second test wall also contained two sections with interior PCM wallboards; one contained nano-PCM dispersed homogeneously in gypsum and the other was gypsum board containing a commercial microencapsulated PCM (MEPCM) for comparison. Each test wall contained a section covered with gypsum board on the interior side, which served as control or a baseline for evaluation of the PCM wallboards. The walls were instrumented with arrays of thermocouples and heat flux transducers. Further, numerical modeling of

  6. Development of a Specific Anaerobic Field Test for Aerobic Gymnastics

    PubMed Central

    Paineli, Vitor de Salles; Azevedo, Rafael de Almeida; Borelli, Claudia Cristine Gomes; Lancha Junior, Antônio Herbert; Gualano, Bruno; Artioli, Guilherme Giannini

    2015-01-01

    The current investigation aimed to develop a valid specific field test to evaluate anaerobic physical performance in Aerobic Gymnastics athletes. We first designed the Specific Aerobic Gymnast Anaerobic Test (SAGAT), which included gymnastics-specific elements performed in maximal repeated sprint fashion, with a total duration of 80-90 s. In order to validate the SAGAT, three independent sub-studies were performed to evaluate the concurrent validity (Study I, n=8), the reliability (Study II, n=10) and the sensitivity (Study III, n=30) of the test in elite female athletes. In Study I, a positive correlation was shown between lower-body Wingate test and SAGAT performance (Mean power: p = 0.03, r = -0.69, CI: -0.94 to 0.03 and Peak power: p = 0.02, r = -0.72, CI: -0.95 to -0.04) and between upper-body Wingate test and SAGAT performance (Mean power: p = 0.03, r = -0.67, CI: -0.94 to 0.02 and Peak power: p = 0.03, r = -0.69, CI: -0.94 to 0.03). Additionally, plasma lactate was similarly increased in response to SAGAT (p = 0.002), lower-body Wingate Test (p = 0.021) and a simulated competition (p = 0.007). In Study II, no differences were found between the time to complete the SAGAT in repeated trials (p = 0.84; Cohen’s d effect size = 0.09; ICC = 0.97, CI: 0.89 to 0.99; MDC95 = 0.12 s). Finally, in Study III the time to complete the SAGAT was significantly lower during the competition cycle when compared to the period before the preparatory cycle (p < 0.001), showing an improvement in SAGAT performance after a specific Aerobic Gymnastics training period. Taken together, these data have demonstrated that SAGAT is a specific, reliable and sensitive measurement of specific anaerobic performance in elite female Aerobic Gymnastics, presenting great potential to be largely applied in training settings. PMID:25876039

  7. Microbial resistance to disinfectants: mechanisms and significance

    SciTech Connect

    Hoff, J.C.; Akin, E.W.

    1986-11-01

    Drinking water disinfection provides the final barrier to transmission of a wide variety of potentially waterborne infectious agents including pathogenic bacteria, viruses, and protozoa. These agents differ greatly in their innate resistance to inactivation by disinfectants, ranging from extremely sensitive bacteria to highly resistant protozoan cysts. The close similarity between microorganism inactivation rates and the kinetics of chemical reactions has long been recognized. Ideally, under carefully controlled conditions, microorganism inactivation rates simulate first-order chemical reaction rates, making it possible to predict the effectiveness of disinfection under specific conditions. In practice, changes in relative resistance and deviations from first-order kinetics are caused by a number of factors, including microbial growth conditions, aggregation, and association with particulate materials. The net effect of all these factors is a reduction in the effectiveness and predictability of disinfection processes. To ensure effective pathogen control, disinfectant concentrations and contact times greater than experimentally determined values may be required. Of the factors causing enhanced disinfection resistance, protection by association with particulate matter is the most significant. Therefore, removal of particulate matter is an important step in increasing the effectiveness of disinfection processes.

  8. Photo-active float for field water disinfection.

    PubMed

    Shwetharani, R; Balakrishna, R Geetha

    2016-03-01

    The present study investigates the antibacterial activity of a photoactive float fabricated with visible light active N-F-TiO2 for the disinfection of field water widely contaminated with Gram positive and Gram negative bacteria like, Salmonella typhimurium (Gram negative), Escherichia coli (Gram negative), Staphylococcus aureus (Gram positive), Bacillus species (Gram positive), and Pseudomonas species (Gram negative). The antibacterial activity can be attributed to the unique properties of the photocatalyst, which releases reactive oxygen species in aqueous solution, under the illumination of sunlight. N-F-TiO2 nanoparticles efficiently photocatalyse the destruction of all the bacteria present in the contaminated water, giving clean water. The inactivation of bacteria is confirmed by a standard plate count method, MDA, RNA and DNA analysis. The purity of water was further validated by SPC indicating nil counts of bacteria after two days of storing and testing. The photocatalysts were characterized by XRD, BET measurement, SEM, EDX, UV-Vis and PL analysis.

  9. Inactivation of Aspergillus flavus in drinking water after treatment with UV irradiation followed by chlorination.

    PubMed

    Al-Gabr, Hamid Mohammad; Zheng, Tianling; Yu, Xin

    2013-10-01

    The disinfection process for inactivating microorganisms at drinking water treatment plants is aimed for safety of drinking water for humans from a microorganism, such as bacteria, viruses, algae, fungi by using chlorination, ozonation, UV irradiation, etc. In the present study, a combination of two disinfectants, UV irradiation followed by chlorination, was evaluated for inactivating Aspergillus flavus under low contact time and low dosage of UV irradiation. The results indicated an inverse correlation between the inactivation of A. flavus by using UV irradiation only or chlorination alone. By using UV radiation, the 2 log10 control of A. flavus was achieved after 30 s of irradiation, while chlorination was observed to be more effective than UV, where the 2 log was achieved at chlorine concentration of 0.5, 1, 2 and 3 mg/l, in contact time of 60, 5, 1 and 1 min, respectively. However, combined use (UV irradiation followed by chlorination) was more effective than using either UV or chlorination alone; 5 s UV irradiation followed by chlorination produced 4 log10 reduction of A. flavus at chlorine concentrations of 2 and 3 mg/l under a contact time of 15 min. The results indicated that efficiency of UV irradiation improves when followed by chlorination at low concentrations.

  10. Comparison of indicator bacteria inactivation by the ultraviolet and the ultraviolet/hydrogen peroxide disinfection processes in humic waters.

    PubMed

    Teksoy, Arzu; Alkan, Ufuk; Eleren, Sevil Çalışkan; Topaç, Burcu Şengül; Sağban, Fatma Olcay Topaç; Başkaya, Hüseyin Savaş

    2011-12-01

    The aim of the present study was to evaluate responses of potential indicator bacteria (i.e. Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis) to the ultraviolet (UV) radiation and the UV/hydrogen peroxide (H₂O₂) disinfection processes of surface waters with different qualities in terms of humic content. The UV and the UV/H₂O₂ processes were applied to waters containing various concentrations of fulvic acid in order to inactivate E. coli, P. aeruginosa and B. subtilis spores. Three fulvic acid (0, 2 and 6 mg l(-1)) and four H₂O₂ (0, 10, 25 and 50 mg l(-1)) concentrations were used. Results showed that the k values of E. coli, P. aeruginosa and B. subtilis spores varied between 2.22 and 4.00, 1.73 and 3.58, and 1.40 and 1.86, respectively, in all test conditions. The sensitivity of the test organisms followed a decreasing order of E. coli > P. aeruginosa > B. subtilis. Results of the study indicated that the blocking effect of fulvic acid for the UV light was diminished by using H₂O₂ in combination with the UV radiation. Findings of the present study strongly suggested that the UV/H₂O₂ process was significantly effective on the inactivation of E. coli and P. aeruginosa in humic waters, whereas it induced little or no apparent contribution to the disinfection efficiency of B. subtilis spores.

  11. A comparative study on the pulsed UV and the low-pressure UV inactivation of a range of microbial species in water.

    PubMed

    Garvey, Mary; Thokala, Nikhil; Rowan, Neil

    2014-12-01

    Research into alternative methods of disinfecting water and wastewater has proven necessary due to the emergence of chlorine-resistant organisms and the disinfection byproducts associated with chlorine use. The use of UV light to inactivate microbial species has proven effective, however; standard UV lamps have proven to be less effective in their ability to inactivate parasites and bacterial endospores in water treatment settings. Pulsed UV (PUV) light may potentially provide a novel alternative to water and wastewater disinfection. Research outlined in this study assesses the potential of a novel PUV system for the rapid and reproducible inactivation of a range of test species including Bacillus endospores. In comparison to standard low-pressure (LP) UV lamps, this PUV system provided significantly higher levels of inactivation for all test species. Furthermore, there was a remarkable decrease in time needed to obtain significant inactivation rates following treatment with PUV compared to LP-UV. With the PUV system, a 70-second treatment time (7.65 μJ/cm2) resulted in similar inactivation rates of Bacillus endospores to that of the LP-UV inactivation of their vegetative counterpart. Also, at PUV doses exceeding 4.32 J/cm2, there was not a significant difference in the PUV inactivation of Bacillus endospores in the absence or presence of 10 ppm organic matter. However, the presence of organic matter resulted in a significant reduction in microbial inactivation for all treatment doses using the LP-UV system. The findings of this study suggest that PUV technology may provide a rapid effective method for the disinfection of water and wastewater.

  12. Formation of disinfection byproducts in a recirculating mariculture system: emerging concerns.

    PubMed

    Qiang, Zhimin; Zhang, Haiting; Dong, Huiyu; Adams, Craig; Luan, Gang; Wang, Lei

    2015-02-01

    Disinfection is commonly employed in recirculating mariculture systems (RMS) to control animal diseases and improve seawater quality; however, little is known about the occurrence of disinfection byproducts (DBPs) formed in such RMS. Beijing Aquarium is a typical RMS with artificially prepared seawater and mainly adopts a decentralized treatment strategy for different animal tanks, including sand filtration, foam fractionation, and disinfection (O3, UV, and O3/ClO2). This study reveals that the adopted disinfection processes were highly effective in controlling marine heterotrophic bacteria; however, some concerns were raised on the formation of various kinds of DBPs, including secondary oxidants, inorganic oxyanions, and hazardous organic species. Free chlorine and free bromine were generated from ozonation at health-relevant concentrations. High concentrations of BrO3(-) and ClO3(-) were formed in mammal tanks, which exceeded the USEPA-regulated maximum contaminant level (MCL) for drinking water by 19-25 and 52-54 times, respectively. Extremely high concentrations of NO3(-) were detected in mammal tanks, which considerably exceeded the MCL regulated by the Sea Water Quality Standard of China for the mariculture industry (Class II) by about 1100 times. Undoubtedly, the presence of various DBPs poses serious health threats to aquarium animals. To solve these problems, potential control measures for DBPs are proposed.

  13. Solar water disinfection (SODIS): a review from bench-top to roof-top.

    PubMed

    McGuigan, Kevin G; Conroy, Ronán M; Mosler, Hans-Joachim; du Preez, Martella; Ubomba-Jaswa, Eunice; Fernandez-Ibañez, Pilar

    2012-10-15

    Solar water disinfection (SODIS) has been known for more than 30 years. The technique consists of placing water into transparent plastic or glass containers (normally 2L PET beverage bottles) which are then exposed to the sun. Exposure times vary from 6 to depending on the intensity of sunlight and sensitivity of the pathogens. Its germicidal effect is based on the combined effect of thermal heating of solar light and UV radiation. It has been repeatedly shown to be effective for eliminating microbial pathogens and reduce diarrhoeal morbidity including cholera. Since 1980 much research has been carried out to investigate the mechanisms of solar radiation induced cell death in water and possible enhancement technologies to make it faster and safer. Since SODIS is simple to use and inexpensive, the method has spread throughout the developing world and is in daily use in more than 50 countries in Asia, Latin America, and Africa. More than 5 million people disinfect their drinking water with the solar disinfection (SODIS) technique. This review attempts to revise all relevant knowledge about solar disinfection from microbiological issues, laboratory research, solar testing, up to and including real application studies, limitations, factors influencing adoption of the technique and health impact.

  14. In Vitro Antifungal Evaluation of Seven Different Disinfectants on Acrylic Resins

    PubMed Central

    Yildirim-Bicer, A. Z.; Peker, I.; Akca, G.; Celik, I.

    2014-01-01

    Objective. The aim of this study was to evaluate alternative methods for the disinfection of denture-based materials. Material and Methods. Two different denture-based materials were included in the study. Before microbial test, the surface roughness of the acrylic resins was evaluated. Then, the specimens were divided into 8 experimental groups (n = 10), according to microorganism considered and disinfection methods used. The specimens were contaminated in vitro by standardized suspensions of Candida albicans ATCC#90028 and Candida albicans oral isolate. The following test agents were tested: sodium hypochlorite (NaOCl 1%), microwave (MW) energy, ultraviolet (UV) light, mouthwash containing propolis (MCP), Corega Tabs, 50% and 100% white vinegar. After the disinfection procedure, the number of remaining microbial cells was evaluated in CFU/mL. Kruskal-Wallis, ANOVA, and Dunn's test were used for multiple comparisons. Mann Whitney U test was used to compare the surface roughness. Results. Statistically significant difference (P < 0.05) was found between autopolymerised and heat-cured acrylic resins. The autopolymerised acrylic resin surfaces were rougher than surfaces of heat-cured acrylic resin. The most effective disinfection method was 100% white vinegar for tested microorganisms and both acrylic resins. Conclusion. This study showed that white vinegar 100% was the most effective method for tested microorganisms. This agent is cost-effective and easy to access and thus may be appropriate for household use. PMID:24995305

  15. [Disinfection by-products reduction of combined disinfection by chlorine and monochloramines in distribution system].

    PubMed

    Liu, Jing; Chen, Chao; Zhang, Xiao-Jian

    2009-09-15

    Halogen disinfection by-products of four chlorined disinfection processes with long contact time in distribution system was compared in the work. These four disinfection processes are free chlorine, monochloramines, free chlorine disinfection in clearwelles while chloramines in distribution system, sequential chlorination disinfection with short-term free chlorine plus chloramines. According to the research, free chlorine generates most trihalomethanes (THMs) and haloacetic acids (HAAs) both in clearwells and distribution system, while monochloramines barely yield halogen DBPs. Free chlorine disinfection in clearwelles while chloramines in distribution system could reduce 9.6% of THMs and 42% of HAAs in 24 h contact time of distribution system compared with free chlorine. But free chlorine has contacted with water for 2 h in this process, halogen DBPs have been yielded substantially. Process of sequential chlorination disinfection could control DBPs more effectively due to keeping a short contact time of free chlorine and water. 48% of THMs and 72% of HAAs are reduced in 24h compared with free chlorine. In conclusion, sequential chlorination disinfection is a more effective disinfection process for controlling DBPs and water safety.

  16. [Virucidal activity of disinfectants. Influence of the serum protein upon the virucidal activity of disinfectants].

    PubMed

    Noda, M; Matsuda, S; Kobayashi, M

    2000-08-01

    Five disinfectants were tested for virucidal activity on three DNA viruses and three RNA viruses in the presence or absence of serum protein. Disinfectants of the aldehyde and halogen groups had a virucidal activity on human herpes virus, bovine rhabdo virus, human immunodeficiency virus, human adeno virus, porcine parvo virus, and polio virus. Disinfectants of the invert and amphoteric soap groups, and biganide group had a destructive effect on RNA and DNA viruses possessing an envelope. The presence of serum protein exerted great influence upon the virucidal activity of disinfectants of the invert and amphoteric soap groups. PMID:11019515

  17. Effect of particles and bioflocculation on ultraviolet disinfection of Escherichia coli.

    PubMed

    Kollu, Kerim; Ormeci, Banu

    2012-03-01

    Presence of particles is known to decrease the effectiveness of ultraviolet (UV) disinfection by shielding the targeted microorganisms from UV light. This study aims to provide an in-depth understanding on the effect of particles and flocs on UV disinfection by using a stable, well-defined and well-controlled synthetic system that can simulate the bioflocculation of particles and microorganisms in water and wastewater samples. The synthetic system was created by using Escherichia coli, latex particles (1, 3.2, 11, 25, and 45 μm), alginate, and divalent cations; and the bioflocculation of particles was achieved naturally, as it would occur in the environment, without using chemical coagulants. E. coli was quantified before and after UV disinfection using membrane filtration. Even in the absence of particles, some of the self-aggregated E. coli could survive a UV dose of 90 mJ/cm(2). E. coli inactivation levels measured in the presence of particles were lower than the inactivation levels measured in the absence of particles. At low UV doses (<9 mJ/cm(2)), neither particle size nor degree of flocculation had a significant effect on the inactivation of E. coli. Particle size had a significant effect on the inactivation of E. coli only at high UV doses (80 mJ/cm(2)), and larger particles (e.g., 25 μm) protected bacteria more compared to smaller particles (e.g., 3.2 and 11 μm). What size of particles flocs were made of (3.2, 11, and 25 μm) did not make a significant difference on the inactivation levels of E. coli. For 3.2 μm particles, there was no significant difference in E. coli inactivation between non-flocculated and flocculated samples at any UV dose. For 11 and 25 μm particles, there was a significant difference in E. coli inactivation between non-flocculated and flocculated samples at 80 mJ/cm(2). Degree of flocculation became a significant factor in determining the number of surviving bacteria only at high UV doses and only for larger particles.

  18. Photocatalytic water disinfection of Cryptosporidium parvum and Giardia lamblia using a fibrous ceramic TiO(2) photocatalyst.

    PubMed

    Navalon, Sergio; Alvaro, Mercedes; Garcia, Hermenegildo; Escrig, Daniel; Costa, Víctor

    2009-01-01

    Cryptosporidium parvum and Giardia lamblia are two of the most chlorine resistant microorganisms with notable adverse effects on humans. Our study shows that waters containing these two protozoa at low concentrations can be efficiently disinfected in continuous flow by using a commercial fibrous ceramic TiO(2) photocatalyst. The efficiency of the photocatalytic disinfection is largely enhanced by adding a small concentration of chlorine. In this way, the residence time on the photoreactor can be considerably shortened. In contrast, under the same conditions and radiance power, UV light without any photocatalyst is significantly less efficient, particularly for G. lamblia. These results exemplify the advantages of the photocatalytic process for safe and complete water disinfection. PMID:19237757

  19. Comparison of UV-Induced Inactivation and RNA Damage in MS2 Phage across the Germicidal UV Spectrum.

    PubMed

    Beck, Sara E; Rodriguez, Roberto A; Hawkins, Michael A; Hargy, Thomas M; Larason, Thomas C; Linden, Karl G

    2015-12-28

    Polychromatic UV irradiation is a common method of pathogen inactivation in the water treatment industry. To improve its disinfection efficacy, more information on the mechanisms of UV inactivation on microorganisms at wavelengths throughout the germicidal UV spectrum, particularly at below 240 nm, is necessary. This work examined UV inactivation of bacteriophage MS2, a common surrogate for enteric pathogens, as a function of wavelength. The bacteriophage was exposed to monochromatic UV irradiation from a tunable laser at wavelengths of between 210 nm and 290 nm. To evaluate the mechanisms of UV inactivation throughout this wavelength range, RT-qPCR (reverse transcription-quantitative PCR) was performed to measure genomic damage for comparison with genomic damage at 253.7 nm. The results indicate that the rates of RNA damage closely mirror the loss of viral infectivity across the germicidal UV spectrum. This demonstrates that genomic damage is the dominant cause of MS2 inactivation from exposure to germicidal UV irradiation. These findings contrast those for adenovirus, for which MS2 is used as a viral surrogate for validating polychromatic UV reactors.

  20. Comparison of UV-Induced Inactivation and RNA Damage in MS2 Phage across the Germicidal UV Spectrum

    PubMed Central

    Beck, Sara E.; Rodriguez, Roberto A.; Hawkins, Michael A.; Hargy, Thomas M.; Larason, Thomas C.

    2015-01-01

    Polychromatic UV irradiation is a common method of pathogen inactivation in the water treatment industry. To improve its disinfection efficacy, more information on the mechanisms of UV inactivation on microorganisms at wavelengths throughout the germicidal UV spectrum, particularly at below 240 nm, is necessary. This work examined UV inactivation of bacteriophage MS2, a common surrogate for enteric pathogens, as a function of wavelength. The bacteriophage was exposed to monochromatic UV irradiation from a tunable laser at wavelengths of between 210 nm and 290 nm. To evaluate the mechanisms of UV inactivation throughout this wavelength range, RT-qPCR (reverse transcription-quantitative PCR) was performed to measure genomic damage for comparison with genomic damage at 253.7 nm. The results indicate that the rates of RNA damage closely mirror the loss of viral infectivity across the germicidal UV spectrum. This demonstrates that genomic damage is the dominant cause of MS2 inactivation from exposure to germicidal UV irradiation. These findings contrast those for adenovirus, for which MS2 is used as a viral surrogate for validating polychromatic UV reactors. PMID:26712541

  1. Conventional and advanced oxidation processes used in disinfection of treated urban wastewater.

    PubMed

    Rodríguez-Chueca, J; Ormad, M P; Mosteo, R; Sarasa, J; Ovelleiro, J L

    2015-03-01

    The purpose of the current study is to compare the inactivation of Escherichia coli in wastewater effluents using conventional treatments (chlorination) and advanced oxidation processes (AOPs) such as UV irradiation, hydrogen peroxide (H2O2)/solar irradiation, and photo-Fenton processes. In addition, an analysis of the operational costs of each treatment is carried out taking into account the optimal dosages of chemicals used. Total inactivation of bacteria (7.5 log) was achieved by means of chlorination and UV irradiation. However, bacterial regrowth was observed 6 hours after the completion of UV treatment, obtaining a disinfection value around 3 to 4 log. On the other hand, the combination H2O2/solar irradiation achieved a maximum inactivation of E. coli of 3.30 ± 0.35 log. The photo-Fenton reaction achieved a level of inactivation of 4.87 ± 0.10 log. The order of disinfection, taking into account the reagent/cost ratio of each treatment, is as follows: chlorination > UV irradiation > photo-Fenton > H2O2/sunlight irradiation.

  2. Disinfection, sterilization, and antisepsis: An overview.

    PubMed

    Rutala, William A; Weber, David J

    2016-05-01

    All invasive procedures involve contact by a medical device or surgical instrument with a patient's sterile tissue or mucous membranes. The level of disinfection or sterilization is dependent on the intended use of the object: critical (items that contact sterile tissue such as surgical instruments), semicritical (items that contact mucous membrane such as endoscopes), and noncritical (devices that contact only intact skin such as stethoscopes) items require sterilization, high-level disinfection and low-level disinfection, respectively. Cleaning must always precede high-level disinfection and sterilization. Antiseptics are essential to infection prevention as part of a hand hygiene program as well as several other uses such as surgical hand antisepsis and pre-operative skin preparation.

  3. Wastewater Disinfectants: Many Called--Few Chosen

    ERIC Educational Resources Information Center

    Smith, James W.

    1978-01-01

    Gives a comparative study of disinfectants used to rid wastewater of pathogens. Concentrates on the effects of chlorine and ozone, with some mention of ultra-violet irradiation, bromine chloride, and chlorine dioxide. (MA)

  4. Environmental Cleaning and Disinfecting for MRSA

    MedlinePlus

    ... stores and other retail stores. Check the disinfectant product’s label on the back of the container. Most, if ... check for an EPA registration number on the product’s label to confirm that it is registered). How should ...

  5. ALTERNATIVE DISINFECTION FOR DRINKING WATER TREATMENT

    EPA Science Inventory

    During a one-yr study at Jefferson Parish, La., the chemical, microbiological, and mutagenic effects os using the major drinkgin water disinfectants (chlorine, chlorine dioxide, chloramine, ozone) were evaluated. Tests were performed on samples collected from various treatment s...

  6. ALTERNATIVE DISINFECTANTS FOR DRINKING WATER TREATMENT

    EPA Science Inventory

    During a one-year study at Jefferson Parish, Louisiana the chemical, microbiological, and mutagenic effects of using the major drinking water disinfectants (chlorine, chlorine dioxide, chloramine, ozone) were evaluated. ests were performed on samples collected from various treatm...

  7. Antiviral activity of alcohol for surface disinfection.

    PubMed

    Moorer, W R

    2003-08-01

    Bacteria and viruses from the patient's mouth travel with dental splatter and spills. A surface disinfectant should possess antiviral activity as well as antibacterial action. Because of frequent and 'open' application in the dental office, such a disinfectant should be non-toxic, non-allergenic and safe for the hygienist. It now appears that high-concentration alcohol mixtures (i.e. 80% ethanol + 5% isopropanol) are not only excellent antibacterials, but quickly inactivate HIV as well as hepatitis B and hepatitis C viruses. Compared to alternative surface disinfectants, use of high-concentration alcohol for the spray-wipe-spray method of surface disinfection in dentistry appears safe and efficient. However, dried matter should be wiped and hydrated first.

  8. [Formaldehyde sediment in incubators following disinfection].

    PubMed

    Wartner, R; Kegel, M; Meyer, H D; Schlüter, G; Wegner, J; Werner, E

    1983-12-01

    Measurements in incubators revealed the presence of formaldehyde concentrations involving a health risk for premature and normal newborns kept and cared for in incubators. Prior to measurements, the incubators had been disinfected by means of formaldehyde vapours in an "Aseptor" disinfecting cabinet (Drägerwerk AG, Lübeck) and then ventilated in strict adherence to operating instructions. The elevated formaldehyde concentrations found had been due to residues of paraformaldehyde and urotropin on the surfaces of the disinfected apparatus, liberating formaldehyde by hydrolysis depending on temperature and relative humidity. There should be a basic reconsideration of the present practice of incubator disinfection. From experiments with activated-carbon filters in incubators it would seem that there is a chance of reducing such formaldehyde concentrations.

  9. 9 CFR 71.10 - Permitted disinfectants.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., Fungicide, and Rodenticide Act (7 U.S.C. 135 et seq.), with tuberculocidal claims, as disinfectants for... confusion, the product of each manufacturer and distributor shall bear a distinctive trade name or...

  10. Chlorination of oxybenzone: Kinetics, transformation, disinfection byproducts formation, and genotoxicity changes.

    PubMed

    Zhang, Shujuan; Wang, Xiaomao; Yang, Hongwei; Xie, Yuefeng F

    2016-07-01

    UV filters are a kind of emerging contaminant, and their transformation behavior in water treatment processes has aroused great concern. In particular, toxic products might be produced during reaction with disinfectants during the disinfection process. As one of the most widely used UV filters, oxybenzone has received significant attention, because its transformation and toxicity changes during chlorine oxidation are a concern. In our study, the reaction between oxybenzone and chlorine followed pseudo-first-order and second-order kinetics. Three transformation products were detected by LC-MS/MS, and the stability of products followed the order of tri-chloro-methoxyphenoyl > di-chlorinated oxybenzone > mono-chlorinated oxybenzone. Disinfection byproducts (DBPs) including chloroform, trichloroacetic acid, dichloroacetic acid and chloral hydrate were quickly formed, and increased at a slower rate until their concentrations remained constant. The maximum DBP/oxybenzone molar yields for the four compounds were 12.02%, 6.28%, 0.90% and 0.23%, respectively. SOS/umu genotoxicity test indicated that genotoxicity was highly elevated after chlorination, and genotoxicity showed a significantly positive correlation with the response of tri-chloro-methoxyphenoyl. Our results indicated that more genotoxic transformation products were produced in spite of the elimination of oxybenzone, posing potential threats to drinking water safety. This study shed light on the formation of DBPs and toxicity changes during the chlorination process of oxybenzone.

  11. Chlorination of oxybenzone: Kinetics, transformation, disinfection byproducts formation, and genotoxicity changes.

    PubMed

    Zhang, Shujuan; Wang, Xiaomao; Yang, Hongwei; Xie, Yuefeng F

    2016-07-01

    UV filters are a kind of emerging contaminant, and their transformation behavior in water treatment processes has aroused great concern. In particular, toxic products might be produced during reaction with disinfectants during the disinfection process. As one of the most widely used UV filters, oxybenzone has received significant attention, because its transformation and toxicity changes during chlorine oxidation are a concern. In our study, the reaction between oxybenzone and chlorine followed pseudo-first-order and second-order kinetics. Three transformation products were detected by LC-MS/MS, and the stability of products followed the order of tri-chloro-methoxyphenoyl > di-chlorinated oxybenzone > mono-chlorinated oxybenzone. Disinfection byproducts (DBPs) including chloroform, trichloroacetic acid, dichloroacetic acid and chloral hydrate were quickly formed, and increased at a slower rate until their concentrations remained constant. The maximum DBP/oxybenzone molar yields for the four compounds were 12.02%, 6.28%, 0.90% and 0.23%, respectively. SOS/umu genotoxicity test indicated that genotoxicity was highly elevated after chlorination, and genotoxicity showed a significantly positive correlation with the response of tri-chloro-methoxyphenoyl. Our results indicated that more genotoxic transformation products were produced in spite of the elimination of oxybenzone, posing potential threats to drinking water safety. This study shed light on the formation of DBPs and toxicity changes during the chlorination process of oxybenzone. PMID:27085067

  12. Photocatalytic disinfection of indoor air

    SciTech Connect

    Goswami, D.Y.; Trivedi, D.M.; Block, S.S.

    1997-02-01

    The present study demonstrated the antibacterial effect of photocatalytic oxidation in indoor air using titanium dioxide as the catalyst. Through a series of experiments, it was determined that titanium dioxide did enhance the inactivation rate of the microorganisms under certain conditions. In these experiments the air velocity, relative humidity, and UV (350 nm) intensity were varied. It was found that higher velocities retarded the destruction rate due to the low retention time in the reactor. TiO{sub 2} also did not accelerate the reaction at low humidities (30%). At a relative humidity of 50%, there was complete inactivation of the organisms, but at higher humidities (85%), 10% of the organisms were still viable. The experiments showed that at higher UV intensities, most of the activation was done by the UV photons. However, the photons were not able to completely inactivate the microorganisms. In the photocatalysis experiments there was complete inactivation of the bacteria.

  13. New developments in disinfection and sterilization.

    PubMed

    Wallace, Craig A

    2016-05-01

    A review of regulatory clearances for selected new sterilization and disinfection products for the period January 2012-June 2015 indicates continued leverage of established technologies for steam and low-temperature sterilization, and high-level disinfection. New products in these areas were typically modified and improved versions of existing products, with the exception of a new combination hydrogen peroxide/ozone sterilizer. Development of new low-temperature sterilization technologies to address continued evolution of complex medical devices is expected to continue.

  14. Field test of Ku-band transmission using small-dish (IBS) earth stations

    NASA Astrophysics Data System (ADS)

    Takeuchi, Yoshio; Nohara, Mitsuo; Takahata, Fumio

    A field test of an experimental Intelsat business services (IBS) communications system was conducted for approximately one year to evaluate the transmission quality at the Ku-band before IBS was brought into commercial use in Japan. At first, the configuration of the field test is outlined. Then, the results of the field test are demonstrated and discussed in detail, especially with respect to the bit error rate performance, which specifies the transmission quality of the digital communications.

  15. An environmental disinfection odyssey: evaluation of sequential interventions to improve disinfection of Clostridium difficile isolation rooms.

    PubMed

    Sitzlar, Brett; Deshpande, Abhishek; Fertelli, Dennis; Kundrapu, Sirisha; Sethi, Ajay K; Donskey, Curtis J

    2013-05-01

    OBJECTIVE. Effective disinfection of hospital rooms after discharge of patients with Clostridium difficile infection (CDI) is necessary to prevent transmission. We evaluated the impact of sequential cleaning and disinfection interventions by culturing high-touch surfaces in CDI rooms after cleaning. DESIGN. Prospective intervention. SETTING. A Veterans Affairs hospital. INTERVENTIONS. During a 21-month period, 3 sequential tiered interventions were implemented: (1) fluorescent markers to provide monitoring and feedback on thoroughness of cleaning facility-wide, (2) addition of an automated ultraviolet radiation device for adjunctive disinfection of CDI rooms, and (3) enhanced standard disinfection of CDI rooms, including a dedicated daily disinfection team and implementation of a process requiring supervisory assessment and clearance of terminally cleaned CDI rooms. To determine the impact of the interventions, cultures were obtained from CDI rooms after cleaning and disinfection. RESULTS. The fluorescent marker intervention improved the thoroughness of cleaning of high-touch surfaces (from 47% to 81% marker removal; P < .0001). Relative to the baseline period, the prevalence of positive cultures from CDI rooms was reduced by 14% (P=.024), 48% (P <.001), and 89% (P=.006) with interventions 1, 2, and 3, respectively. During the baseline period, 67% of CDI rooms had positive cultures after disinfection, whereas during interventions periods 1, 2, and 3 the percentages of CDI rooms with positive cultures after disinfection were reduced to 57%, 35%, and 7%, respectively. CONCLUSIONS. An intervention that included formation of a dedicated daily disinfection team and implementation of a standardized process for clearing CDI rooms achieved consistent CDI room disinfection. Culturing of CDI rooms provides a valuable tool to drive improvements in environmental disinfection.

  16. An environmental disinfection odyssey: evaluation of sequential interventions to improve disinfection of Clostridium difficile isolation rooms.

    PubMed

    Sitzlar, Brett; Deshpande, Abhishek; Fertelli, Dennis; Kundrapu, Sirisha; Sethi, Ajay K; Donskey, Curtis J

    2013-05-01

    OBJECTIVE. Effective disinfection of hospital rooms after discharge of patients with Clostridium difficile infection (CDI) is necessary to prevent transmission. We evaluated the impact of sequential cleaning and disinfection interventions by culturing high-touch surfaces in CDI rooms after cleaning. DESIGN. Prospective intervention. SETTING. A Veterans Affairs hospital. INTERVENTIONS. During a 21-month period, 3 sequential tiered interventions were implemented: (1) fluorescent markers to provide monitoring and feedback on thoroughness of cleaning facility-wide, (2) addition of an automated ultraviolet radiation device for adjunctive disinfection of CDI rooms, and (3) enhanced standard disinfection of CDI rooms, including a dedicated daily disinfection team and implementation of a process requiring supervisory assessment and clearance of terminally cleaned CDI rooms. To determine the impact of the interventions, cultures were obtained from CDI rooms after cleaning and disinfection. RESULTS. The fluorescent marker intervention improved the thoroughness of cleaning of high-touch surfaces (from 47% to 81% marker removal; P < .0001). Relative to the baseline period, the prevalence of positive cultures from CDI rooms was reduced by 14% (P=.024), 48% (P <.001), and 89% (P=.006) with interventions 1, 2, and 3, respectively. During the baseline period, 67% of CDI rooms had positive cultures after disinfection, whereas during interventions periods 1, 2, and 3 the percentages of CDI rooms with positive cultures after disinfection were reduced to 57%, 35%, and 7%, respectively. CONCLUSIONS. An intervention that included formation of a dedicated daily disinfection team and implementation of a standardized process for clearing CDI rooms achieved consistent CDI room disinfection. Culturing of CDI rooms provides a valuable tool to drive improvements in environmental disinfection. PMID:23571361

  17. Sorting through the Wealth of Options: Comparative Evaluation of Two Ultraviolet Disinfection Systems

    PubMed Central

    Nerandzic, Michelle M.; Fisher, Christopher W.; Donskey, Curtis J.

    2014-01-01

    Background Environmental surfaces play an important role in the transmission of healthcare-associated pathogens. Because environmental cleaning is often suboptimal, there is a growing demand for safe, rapid, and automated disinfection technologies, which has lead to a wealth of novel disinfection options available on the market. Specifically, automated ultraviolet-C (UV-C) devices have grown in number due to the documented efficacy of UV-C for reducing healthcare-acquired pathogens in hospital rooms. Here, we assessed and compared the impact of pathogen concentration, organic load, distance, and radiant dose on the killing efficacy of two analogous UV-C devices. Principal Findings The devices performed equivalently for each impact factor assessed. Irradiation delivered for 41 minutes at 4 feet from the devices consistently reduced C. difficile spores by ∼ 3 log10CFU/cm2, MRSA by>4 log10CFU/cm2, and VRE by >5 log10CFU/cm2. Pathogen concentration did not significantly impact the killing efficacy of the devices. However, both a light and heavy organic load had a significant negative impacted on the killing efficacy of the devices. Additionally, increasing the distance to 10 feet from the devices reduced the killing efficacy to ≤3 log10CFU/cm2 for MRSA and VRE and <2 log10CFU/cm2 for C.difficile spores. Delivery of reduced timed doses of irradiation particularly impacted the ability of the devices to kill C. difficile spores. MRSA and VRE were reduced by >3 log10CFU/cm2 after only 10 minutes of irradiation, while C. difficile spores required 40 minutes of irradiation to achieve a similar reduction. Conclusions The UV-C devices were equally effective for killing C. difficile spores, MRSA, and VRE. While neither device would be recommended as a stand-alone disinfection procedure, either device would be a useful adjunctive measure to routine cleaning in healthcare facilities. PMID:25247783

  18. Non-inferiority of pulsed xenon UV light versus bleach for reducing environmental Clostridium difficile contamination on high-touch surfaces in Clostridium difficile infection isolation rooms.

    PubMed

    Ghantoji, Shashank S; Stibich, Mark; Stachowiak, Julie; Cantu, Sherry; Adachi, Javier A; Raad, Issam I; Chemaly, Roy F

    2015-02-01

    The standard for Clostridium difficile surface decontamination is bleach solution at a concentration of 10 % of sodium hypochlorite. Pulsed xenon UV light (PX-UV) is a means of quickly producing germicidal UV that has been shown to be effective in reducing environmental contamination by C. difficile spores. The purpose of this study was to investigate whether PX-UV was equivalent to bleach for decontamination of surfaces in C. difficile infection isolation rooms. High-touch surfaces in rooms previously occupied by C. difficile infected patients were sampled after discharge but before and after cleaning using either bleach or non-bleach cleaning followed by 15 min of PX-UV treatment. A total of 298 samples were collected by using a moistened wipe specifically designed for the removal of spores. Prior to disinfection, the mean contamination level was 2.39 c.f.u. for bleach rooms and 22.97 for UV rooms. After disinfection, the mean level of contamination for bleach was 0.71 c.f.u. (P = 0.1380), and 1.19 c.f.u. (P = 0.0017) for PX-UV disinfected rooms. The difference in final contamination levels between the two cleaning protocols was not significantly different (P = 0.9838). PX-UV disinfection appears to be at least equivalent to bleach in the ability to decrease environmental contamination with C. difficile spores. Larger studies are needed to validate this conclusion.

  19. Non-inferiority of pulsed xenon UV light versus bleach for reducing environmental Clostridium difficile contamination on high-touch surfaces in Clostridium difficile infection isolation rooms

    PubMed Central

    Ghantoji, Shashank S.; Stibich, Mark; Stachowiak, Julie; Cantu, Sherry; Adachi, Javier A.; Raad, Issam I.

    2015-01-01

    The standard for Clostridium difficile surface decontamination is bleach solution at a concentration of 10 % of sodium hypochlorite. Pulsed xenon UV light (PX-UV) is a means of quickly producing germicidal UV that has been shown to be effective in reducing environmental contamination by C. difficile spores. The purpose of this study was to investigate whether PX-UV was equivalent to bleach for decontamination of surfaces in C. difficile infection isolation rooms. High-touch surfaces in rooms previously occupied by C. difficile infected patients were sampled after discharge but before and after cleaning using either bleach or non-bleach cleaning followed by 15 min of PX-UV treatment. A total of 298 samples were collected by using a moistened wipe specifically designed for the removal of spores. Prior to disinfection, the mean contamination level was 2.39 c.f.u. for bleach rooms and 22.97 for UV rooms. After disinfection, the mean level of contamination for bleach was 0.71 c.f.u. (P = 0.1380), and 1.19 c.f.u. (P = 0.0017) for PX-UV disinfected rooms. The difference in final contamination levels between the two cleaning protocols was not significantly different (P = 0.9838). PX-UV disinfection appears to be at least equivalent to bleach in the ability to decrease environmental contamination with C. difficile spores. Larger studies are needed to validate this conclusion. PMID:25627208

  20. UV-induced self-aggregation of E. coli after low and medium pressure ultraviolet irradiation.

    PubMed

    Kollu, Kerim; Örmeci, Banu

    2015-07-01

    Presence of aggregated bacteria has been shown to decrease the efficacy of ultraviolet (UV) disinfection and there is some indication that UV irradiation may promote aggregation of bacteria among themselves. This study aims to provide an in-depth understanding of the effect of UV light on inducing self-aggregation of Escherichia coli bacteria by using microscopy and particle counter analysis techniques. The bacteria were observed and quantified before and after UV irradiation by employing size and concentration parameters. Four doses of low-pressure (LP) UV irradiation, 20, 40, 60 and 80 mJ/cm(2), and two doses of medium-pressure (MP) UV irradiation, 40 and 80 mJ/cm(2), were tested. At all LP UV doses tested, a significant increase in particle size was observed following UV exposure, indicating UV-induced self-aggregation. However, the magnitude of UV dose did not seem to have an impact. In the MP UV experiments, only a dose of 80 mJ/cm(2) had a significant impact on the formation of aggregates upon UV exposure. Changing the light intensity and exposure time to deliver the same LP UV dose resulted in different levels of aggregation. The results indicated that UV light intensity and wavelength may play a role in aggregation of bacteria. PMID:26002538

  1. Microbial disinfection of water with endotoxin degradation by photocatalysis using Ag@TiO2 core shell nanoparticles.

    PubMed

    S, Sreeja; K, Vidya Shetty

    2016-09-01

    The studies on photocatalytic disinfection of water contaminated with Escherichia coli using Ag core and TiO2 shell (Ag@TiO2) nanoparticles under UV irradiation showed that these nanoparticles are very efficient in water disinfection both in their free and immobilised form. Complete disinfection of 40 × 10(8) CFU/mL could be achieved in 60 min with 0.4 g/L catalyst loading and in 35 min with 1 g/L catalyst loading. Ag@TiO2 nanoparticles were found to be superior to TiO2 nanoparticles in photocatalytic disinfection of water. Kinetics of disinfection followed Chick's law, and the pseudo-first-order rate constant was 0.0168 min(-1) for a catalyst loading of 0.1 g/L. Disinfection of water and degradation of endotoxins (harmful disinfection residual) occurred simultaneously during photocatalysis thereby making the treated water safe for use. Endotoxin degradation showed a shifting order of kinetics. The rate of photocatalysis with nanoparticles immobilised in cellulose acetate film was marginally lower as compared to that of free nanoparticles. Negligible Ag ion leakage and re-growth of cells post-photo-catalytic treatment of water confirmed that complete disintegration of E. coli occurred during photocatalysis making the treated water safe for use. Therefore, Ag@TiO2 nanoparticles have a potential for large-scale application in drinking water treatment plants and household purification units.

  2. Microbial disinfection of water with endotoxin degradation by photocatalysis using Ag@TiO2 core shell nanoparticles.

    PubMed

    S, Sreeja; K, Vidya Shetty

    2016-09-01

    The studies on photocatalytic disinfection of water contaminated with Escherichia coli using Ag core and TiO2 shell (Ag@TiO2) nanoparticles under UV irradiation showed that these nanoparticles are very efficient in water disinfection both in their free and immobilised form. Complete disinfection of 40 × 10(8) CFU/mL could be achieved in 60 min with 0.4 g/L catalyst loading and in 35 min with 1 g/L catalyst loading. Ag@TiO2 nanoparticles were found to be superior to TiO2 nanoparticles in photocatalytic disinfection of water. Kinetics of disinfection followed Chick's law, and the pseudo-first-order rate constant was 0.0168 min(-1) for a catalyst loading of 0.1 g/L. Disinfection of water and degradation of endotoxins (harmful disinfection residual) occurred simultaneously during photocatalysis thereby making the treated water safe for use. Endotoxin degradation showed a shifting order of kinetics. The rate of photocatalysis with nanoparticles immobilised in cellulose acetate film was marginally lower as compared to that of free nanoparticles. Negligible Ag ion leakage and re-growth of cells post-photo-catalytic treatment of water confirmed that complete disintegration of E. coli occurred during photocatalysis making the treated water safe for use. Therefore, Ag@TiO2 nanoparticles have a potential for large-scale application in drinking water treatment plants and household purification units. PMID:27259963

  3. Effect of Nonthermal, Conventional, and Combined Disinfection Technologies on the Stability of Human Adenoviruses as Fecal Contaminants on Surfaces of Fresh Ready-to-Eat Products.

    PubMed

    Birmpa, Angeliki; Bellou, Maria; Kokkinos, Petros; Vantarakis, Apostolos

    2016-03-01

    Over one-half of foodborne diseases are believed to be of viral origin. The ability of viruses to persist in the environment and fresh produce, as well as their low infectious dose, allows even a small amount of contamination to cause serious foodborne problems. Moreover, the consumer's demands for fresh, convenient, and safe foods have prompted research into alternative food disinfection technologies. Our study focuses on viral inactivation by both conventional and alternative nonthermal disinfection technologies on different fresh ready-to-eat food products. The use of chlorine, as well as that of nonthermal technologies such as UV light and ultrasound (US), was tested for different treatment times. UV nonthermal technology was found to be more effective for the disinfection of human adenoviruses (hAdVs) compared with US, achieving a log reduction of 2.13, 1.25, and 0.92 for lettuce, strawberries, and cherry tomatoes, respectively, when UV treatment was implemented for 30 min. US treatment for the same period achieved a log reduction of 0.85, 0.53, and 0.36, respectively. The sequential use of US and UV was found to be more effective compared with when the treatments were used separately, for the same treatment time, thus indicating a synergistic effect. In addition, human adenoviruses were inactivated sooner, when chlorine treatment was used. Therefore, the effect of each disinfection method was dependent upon the treatment time and the type of food. PMID:26939656

  4. Methodology for modeling the disinfection efficiency of fresh-cut leafy vegetables wash water applied on peracetic acid combined with lactic acid.

    PubMed

    Van Haute, S; López-Gálvez, F; Gómez-López, V M; Eriksson, Markus; Devlieghere, F; Allende, Ana; Sampers, I

    2015-09-01

    A methodology to i) assess the feasibility of water disinfection in fresh-cut leafy greens wash water and ii) to compare the disinfectant efficiency of water disinfectants was defined and applied for a combination of peracetic acid (PAA) and lactic acid (LA) and comparison with free chlorine was made. Standardized process water, a watery suspension of iceberg lettuce, was used for the experiments. First, the combination of PAA+LA was evaluated for water recycling. In this case disinfectant was added to standardized process water inoculated with Escherichia coli (E. coli) O157 (6logCFU/mL). Regression models were constructed based on the batch inactivation data and validated in industrial process water obtained from fresh-cut leafy green processing plants. The UV254(F) was the best indicator for PAA decay and as such for the E. coli O157 inactivation with PAA+LA. The disinfection efficiency of PAA+LA increased with decreasing pH. Furthermore, PAA+LA efficacy was assessed as a process water disinfectant to be used within the washing tank, using a dynamic washing process with continuous influx of E. coli O157 and organic matter in the washing tank. The process water contamination in the dynamic process was adequately estimated by the developed model that assumed that knowledge of the disinfectant residual was sufficient to estimate the microbial contamination, regardless the physicochemical load. Based on the obtained results, PAA+LA seems to be better suited than chlorine for disinfecting process wash water with a high organic load but a higher disinfectant residual is necessary due to the slower E. coli O157 inactivation kinetics when compared to chlorine.

  5. Methodology for modeling the disinfection efficiency of fresh-cut leafy vegetables wash water applied on peracetic acid combined with lactic acid.

    PubMed

    Van Haute, S; López-Gálvez, F; Gómez-López, V M; Eriksson, Markus; Devlieghere, F; Allende, Ana; Sampers, I

    2015-09-01

    A methodology to i) assess the feasibility of water disinfection in fresh-cut leafy greens wash water and ii) to compare the disinfectant efficiency of water disinfectants was defined and applied for a combination of peracetic acid (PAA) and lactic acid (LA) and comparison with free chlorine was made. Standardized process water, a watery suspension of iceberg lettuce, was used for the experiments. First, the combination of PAA+LA was evaluated for water recycling. In this case disinfectant was added to standardized process water inoculated with Escherichia coli (E. coli) O157 (6logCFU/mL). Regression models were constructed based on the batch inactivation data and validated in industrial process water obtained from fresh-cut leafy green processing plants. The UV254(F) was the best indicator for PAA decay and as such for the E. coli O157 inactivation with PAA+LA. The disinfection efficiency of PAA+LA increased with decreasing pH. Furthermore, PAA+LA efficacy was assessed as a process water disinfectant to be used within the washing tank, using a dynamic washing process with continuous influx of E. coli O157 and organic matter in the washing tank. The process water contamination in the dynamic process was adequately estimated by the developed model that assumed that knowledge of the disinfectant residual was sufficient to estimate the microbial contamination, regardless the physicochemical load. Based on the obtained results, PAA+LA seems to be better suited than chlorine for disinfecting process wash water with a high organic load but a higher disinfectant residual is necessary due to the slower E. coli O157 inactivation kinetics when compared to chlorine. PMID:26065727

  6. Possible monitoring requirements for the disinfectants and disinfection by-products (D/DBP) regulations

    SciTech Connect

    Not Available

    1993-01-01

    The monitoring requirements presented in the report were developed by EPA before a negotiated Disinfectants and Disinfection By-Products (D/DBP) rule was considered. The framework described herein may be substantially changed as a result of the negotiated rulemaking process. The document is useful to consider in developing various monitoring options during the negotiated rulemaking process.

  7. Ultraviolet, chlorine and ozone disinfection of some enteroviruses in drinking water and treated effluents.

    PubMed

    Ali, M A

    1997-01-01

    The inactivation efficiency of chlorine, ultraviolet light and ozone were determined for poliovirus type 3, Coxsackievirus type B4 and Hepatitis A virus in drinking water and treated effluent. Ultraviolet was more efficient than the other two disinfectants at wave length 254 nm where no infective virus was detected after 4 min of UV irradiation in both drinking water and treated effluent. Inactivation by chlorine dose more than 25 mg/L was sufficient for studied viruses in both drinking water and treated effluent. Also virus-seeded drinking water was exposed to ozone for 18 min at ozone rate of 319 mg/L/h to obtain the maximum inactivation of PV3, CoxB4 and HAV but about 20 min of ozone exposure was needed for treated effluent. Physico-chemical parameters were measured before and after disinfection assay. No significant changes were observed.

  8. Solar and photocatalytic disinfection of protozoan, fungal and bacterial microbes in drinking water.

    PubMed

    Lonnen, J; Kilvington, S; Kehoe, S C; Al-Touati, F; McGuigan, K G

    2005-03-01

    The ability of solar disinfection (SODIS) and solar photocatalytic (TiO(2)) disinfection (SPC-DIS) batch-process reactors to inactivate waterborne protozoan, fungal and bacterial microbes was evaluated. After 8 h simulated solar exposure (870 W/m(2) in the 300 nm-10 microm range, 200 W/m(2) in the 300-400 nm UV range), both SPC-DIS and SODIS achieved at least a 4 log unit reduction in viability against protozoa (the trophozoite stage of Acanthamoeba polyphaga), fungi (Candida albicans, Fusarium solani) and bacteria (Pseudomonas aeruginosa, Escherichia coli). A reduction of only 1.7 log units was recorded for spores of Bacillus subtilis. Both SODIS and SPC-DIS were ineffective against the cyst stage of A. polyphaga.

  9. Altered UV absorbance and cytotoxicity of chlorinated sunscreen agents.

    PubMed

    Sherwood, Vaughn F; Kennedy, Steven; Zhang, Hualin; Purser, Gordon H; Sheaff, Robert J

    2012-12-01

    Sunscreens are widely utilized due to the adverse effects of ultraviolet (UV) radiation on human health. The safety of their active ingredients as well as that of any modified versions generated during use is thus of concern. Chlorine is used as a chemical disinfectant in swimming pools. Its reactivity suggests sunscreen components might be chlorinated, altering their absorptive and/or cytotoxic properties. To test this hypothesis, the UV-filters oxybenzone, dioxybenzone, and sulisobenzone were reacted with chlorinating agents and their UV spectra analyzed. In all cases, a decrease in UV absorbance was observed. Given that chlorinated compounds can be cytotoxic, the effect of modified UV-filters on cell viability was examined. Chlorinated oxybenzone and dioxybenzone caused significantly more cell death than unchlorinated controls. In contrast, chlorination of sulisobenzone actually reduced cytotoxicity of the parent compound. Exposing a commercially available sunscreen product to chlorine also resulted in decreased UV absorbance, loss of UV protection, and enhanced cytotoxicity. These observations show chlorination of sunscreen active ingredients can dramatically decrease UV absorption and generate derivatives with altered biological properties.

  10. Impact of wastewater infrastructure upgrades on the urban water cycle: Reduction in halogenated reaction byproducts following conversion from chlorine gas to ultraviolet light disinfection.

    PubMed

    Barber, Larry B; Hladik, Michelle L; Vajda, Alan M; Fitzgerald, Kevin C; Douville, Chris

    2015-10-01

    The municipal wastewater treatment facility (WWTF) infrastructure of the United States is being upgraded to expand capacity and improve treatment, which provides opportunities to assess the impact of full-scale operational changes on water quality. Many WWTFs disinfect their effluent prior to discharge using chlorine gas, which reacts with natural and synthetic organic matter to form halogenated disinfection byproducts (HDBPs). Because HDBPs are ubiquitous in chlorine-disinfected drinking water and have adverse human health implications, their concentrations are regulated in potable water supplies. Less is known about the formation and occurrence of HDBPs in disinfected WWTF effluents that are discharged to surface waters and become part of the de facto wastewater reuse cycle. This study investigated HDBPs in the urban water cycle from the stream source of the chlorinated municipal tap water that comprises the WWTF inflow, to the final WWTF effluent disinfection process before discharge back to the stream. The impact of conversion from chlorine-gas to low-pressure ultraviolet light (UV) disinfection at a full-scale (68,000 m(3) d(-1) design flow) WWTF on HDBP concentrations in the final effluent was assessed, as was transport and attenuation in the receiving stream. Nutrients and trace elements (boron, copper, and uranium) were used to characterize the different urban source waters, and indicated that the pre-upgrade and post-upgrade water chemistry was similar and insensitive to the disinfection process. Chlorinated tap water during the pre-upgrade and post-upgrade samplings contained 11 (mean total concentration=2.7 μg L(-1); n=5) and 10 HDBPs (mean total concentration=4.5 μg L(-1)), respectively. Under chlorine-gas disinfection conditions 13 HDBPs (mean total concentration=1.4 μg L(-1)) were detected in the WWTF effluent, whereas under UV disinfection conditions, only one HDBP was detected. The chlorinated WWTF effluent had greater relative proportions of

  11. Impact of wastewater infrastructure upgrades on the urban water cycle: Reduction in halogenated reaction byproducts following conversion from chlorine gas to ultraviolet light disinfection.

    PubMed

    Barber, Larry B; Hladik, Michelle L; Vajda, Alan M; Fitzgerald, Kevin C; Douville, Chris

    2015-10-01

    The municipal wastewater treatment facility (WWTF) infrastructure of the United States is being upgraded to expand capacity and improve treatment, which provides opportunities to assess the impact of full-scale operational changes on water quality. Many WWTFs disinfect their effluent prior to discharge using chlorine gas, which reacts with natural and synthetic organic matter to form halogenated disinfection byproducts (HDBPs). Because HDBPs are ubiquitous in chlorine-disinfected drinking water and have adverse human health implications, their concentrations are regulated in potable water supplies. Less is known about the formation and occurrence of HDBPs in disinfected WWTF effluents that are discharged to surface waters and become part of the de facto wastewater reuse cycle. This study investigated HDBPs in the urban water cycle from the stream source of the chlorinated municipal tap water that comprises the WWTF inflow, to the final WWTF effluent disinfection process before discharge back to the stream. The impact of conversion from chlorine-gas to low-pressure ultraviolet light (UV) disinfection at a full-scale (68,000 m(3) d(-1) design flow) WWTF on HDBP concentrations in the final effluent was assessed, as was transport and attenuation in the receiving stream. Nutrients and trace elements (boron, copper, and uranium) were used to characterize the different urban source waters, and indicated that the pre-upgrade and post-upgrade water chemistry was similar and insensitive to the disinfection process. Chlorinated tap water during the pre-upgrade and post-upgrade samplings contained 11 (mean total concentration=2.7 μg L(-1); n=5) and 10 HDBPs (mean total concentration=4.5 μg L(-1)), respectively. Under chlorine-gas disinfection conditions 13 HDBPs (mean total concentration=1.4 μg L(-1)) were detected in the WWTF effluent, whereas under UV disinfection conditions, only one HDBP was detected. The chlorinated WWTF effluent had greater relative proportions of

  12. Evaluation of a pulsed xenon ultraviolet disinfection system for reduction of healthcare-associated pathogens in hospital rooms.

    PubMed

    Nerandzic, Michelle M; Thota, Priyaleela; Sankar C, Thriveen; Jencson, Annette; Cadnum, Jennifer L; Ray, Amy J; Salata, Robert A; Watkins, Richard R; Donskey, Curtis J

    2015-02-01

    OBJECTIVE To determine the effectiveness of a pulsed xenon ultraviolet (PX-UV) disinfection device for reduction in recovery of healthcare-associated pathogens. SETTING Two acute-care hospitals. METHODS We examined the effectiveness of PX-UV for killing of Clostridium difficile spores, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococcus (VRE) on glass carriers and evaluated the impact of pathogen concentration, distance from the device, organic load, and shading from the direct field of radiation on killing efficacy. We compared the effectiveness of PX-UV and ultraviolet-C (UV-C) irradiation, each delivered for 10 minutes at 4 feet. In hospital rooms, the frequency of native pathogen contamination on high-touch surfaces was assessed before and after 10 minutes of PX-UV irradiation. RESULTS On carriers, irradiation delivered for 10 minutes at 4 feet from the PX-UV device reduced recovery of C. difficile spores, MRSA, and VRE by 0.55±0.34, 1.85±0.49, and 0.6±0.25 log10 colony-forming units (CFU)/cm2, respectively. Increasing distance from the PX-UV device dramatically reduced killing efficacy, whereas pathogen concentration, organic load, and shading did not. Continuous UV-C achieved significantly greater log10CFU reductions than PX-UV irradiation on glass carriers. On frequently touched surfaces, PX-UV significantly reduced the frequency of positive C. difficile, VRE, and MRSA culture results. CONCLUSIONS The PX-UV device reduced recovery of MRSA, C. difficile, and VRE on glass carriers and on frequently touched surfaces in hospital rooms with a 10-minute UV exposure time. PX-UV was not more effective than continuous UV-C in reducing pathogen recovery on glass slides, suggesting that both forms of UV have some effectiveness at relatively short exposure times.

  13. Second Field Test of the AEL Measure of School Capacity for Improvement

    ERIC Educational Resources Information Center

    Copley, Lisa D.; Meehan, Merrill L.; Howley, Caitlin W.; Hughes, Georgia K.

    2005-01-01

    The major purpose of the second field test of the AEL MSCI instrument was to assess the psychometric properties of the refined version with a larger, more diverse group of respondents. The first objective of this field test was to expand the four-point Likert-type response scale to six points in order to yield more variance in responses. The…

  14. 40 CFR 35.2211 - Field testing for Innovative and Alternative Technology Report.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Field testing for Innovative and Alternative Technology Report. 35.2211 Section 35.2211 Protection of Environment ENVIRONMENTAL PROTECTION... Treatment Works § 35.2211 Field testing for Innovative and Alternative Technology Report. The grantee...

  15. 40 CFR 35.2211 - Field testing for Innovative and Alternative Technology Report.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Field testing for Innovative and Alternative Technology Report. 35.2211 Section 35.2211 Protection of Environment ENVIRONMENTAL PROTECTION... Treatment Works § 35.2211 Field testing for Innovative and Alternative Technology Report. The grantee...

  16. Training Probation and Parole Officers to Provide Substance Abuse Treatment: A Field Test.

    ERIC Educational Resources Information Center

    Cunningham, John A.; Herie, Marilyn; Martin, Garth; Turner, Bonnie J.

    1998-01-01

    The results of field-testing a substance-abuse treatment protocol are reported. Ten probation and parole officers were trained in Structured Relapse Prevention, and 55 clients were treated. Incentives and barriers to treatment are highlighted. The use of this type of field test as a dissemination technique is discussed. (EMK)

  17. The Major Field Test in Business: A Solution to the Problem of Assurance of Learning Assessment?

    ERIC Educational Resources Information Center

    Green, Jeffrey J.; Stone, Courtenay Clifford; Zegeye, Abera

    2014-01-01

    Colleges and universities are being asked by numerous sources to provide assurance of learning assessments of their students and programs. Colleges of business have responded by using a plethora of assessment tools, including the Major Field Test in Business. In this article, the authors show that the use of the Major Field Test in Business for…

  18. 76 FR 12932 - Availability of an Environmental Assessment for Field Testing Fowl Laryngotracheitis-Marek's...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-09

    ..., examines the potential effects that field testing this veterinary vaccine could have on the quality of the... testing this veterinary vaccine will not have a significant impact on the quality of the human environment... Assessment for Field Testing Fowl Laryngotracheitis-Marek's Disease Vaccine, Serotype 3, Live Marek's...

  19. 78 FR 29698 - Availability of an Environmental Assessment for Field Testing a Canine Lymphoma Vaccine, DNA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-21

    ... a Canine Lymphoma Vaccine, DNA AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION... testing, and then to field test, an unlicensed Canine Lymphoma Vaccine, DNA. The environmental assessment... Lymphoma Vaccine, DNA. Possible Field Test Locations: Arizona, Florida, Georgia, New York, North...

  20. 78 FR 58514 - Availability of an Environmental Assessment for Field Testing of a DNA Immunostimulant

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-24

    ... of a DNA Immunostimulant AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION: Notice of... then to field test, an unlicensed DNA Immunostimulant recommended for reduction in morbidity and.... Product: DNA Immunostimulant. Possible Field Test Locations: Texas, Mississippi, and Georgia for...

  1. Small-scale field tests of attract-and-kill stations for pest Tephritid fruit flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field tests were conducted at UF-TREC, Homestead to test efficacy of wax-matrix bait stations and mass trapping for control of the Caribbean fruit fly in a 5 by 30 tree guava planting. Results of the study and the ability to document control using small-scale field tests will be discussed....

  2. Validity of Selected Lab and Field Tests of Physical Working Capacity.

    ERIC Educational Resources Information Center

    Burke, Edmund J.

    The validity of selected lab and field tests of physical working capacity was investigated. Forty-four male college students were administered a series of lab and field tests of physical working capacity. Lab tests include a test of maximum oxygen uptake, the PWC 170 test, the Harvard Step Test, the Progressive Pulse Ratio Test, Margaria Test of…

  3. 40 CFR 35.2211 - Field testing for Innovative and Alternative Technology Report.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Field testing for Innovative and Alternative Technology Report. 35.2211 Section 35.2211 Protection of Environment ENVIRONMENTAL PROTECTION... Treatment Works § 35.2211 Field testing for Innovative and Alternative Technology Report. The grantee...

  4. 40 CFR 35.2211 - Field testing for Innovative and Alternative Technology Report.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Field testing for Innovative and Alternative Technology Report. 35.2211 Section 35.2211 Protection of Environment ENVIRONMENTAL PROTECTION... Treatment Works § 35.2211 Field testing for Innovative and Alternative Technology Report. The grantee...

  5. 40 CFR 35.2211 - Field testing for Innovative and Alternative Technology Report.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Field testing for Innovative and Alternative Technology Report. 35.2211 Section 35.2211 Protection of Environment ENVIRONMENTAL PROTECTION... Treatment Works § 35.2211 Field testing for Innovative and Alternative Technology Report. The grantee...

  6. Reproductive effects of alternative disinfectants

    SciTech Connect

    Carlton, B.D.; Barlett, P.; Basaran, A.; Colling, K.; Osis, I.; Smith, M.K.

    1986-11-01

    Organohalides formed through the reaction of chlorine and organic compounds in natural and waste waters pose potential health hazards. For this reason, alternative water disinfectants that do not form organohalides are being investigated with great interest. In this laboratory, the authors have examined the reproductive effects of chloramine and chlorine administered by gavage in Long-Evans rats. Animals were treated for a total of 66 to 76 days. Males were treated for 56 days and females for 14 days prior to breeding and throughout the 10-day breeding period. Females were treated throughout gestation and lactation. Following breeding, the males were necropsied and evaluated for sperm parameters and reproductive tract histopathology. Adult females and some pups were necropsied at weaning on postnatal day 21. Other pups were treated postweaning until 28 or 40 days of age. These pups were evaluated for the day of vaginal patency and thyroid hormone levels. No differences were observed between control rats and those rats exposed to up to 5 mg/kg/day chlorine or 10 mg/kg/day chloramine when fertility, viability, litter size, day of eye opening, or day of vaginal patency were evaluated. No alterations in sperm count, sperm direct progressive movement percent motility, or sperm morphology were observed among adult male rats. In addition, male and female reproductive organ weights were comparable to their respective control groups, and no significant histopathologic changes were observed among chlorine- or chloramine-treated male and female rats.

  7. Formation and Occurrence of Disinfection By-Products

    EPA Science Inventory

    Disinfection by-products (DBPs) are formed when disinfectants such as chlorine, ozone, chlorine dioxide, or chloramines react with naturally occurring organic matter, anthropogenic contaminants, bromide, and iodide during the production of drinking water. There is concern about D...

  8. Study and application of herbal disinfectants in China.

    PubMed

    Chen, Zhao-Bin

    2004-12-01

    Disinfection means killing or removing pathogenic microorganisms in media to realize a harmless process. A disinfectant, which is also referred to as a disinfection medicine in relevant regulations, is the medicine used to kill microorganisms for the purpose of disinfection. The disinfectants prepared from plants (including traditional Chinese herbal medicines) and the extracts thereof are called herbal disinfectants. China has a long history of using herbal disinfectants. As early as in 533 A.D., the use of Cornel to sterilize well water was recorded in Necessary Techniques for Qi People by Jia Enxie of the Beiwei Dynasty. During the Dragon Boat Festival, people often use fumigants made of traditional Chinese herbal medicines like Chinese Atractylodes, Argy Wormwood Leaf and Red Arsenic Sulfide to smoke their houses, so as to ward off plagues and drive away evils. In fact this is now a kind of disinfection practice.

  9. MULTISPECTRAL IDENTIFICATION OF CHLORINE DIOXIDE DISINFECTION BYPRODUCTS IN DRINKING WATER

    EPA Science Inventory

    This paper discusses the identification of organic disinfection byproducts (DBPs) at a pilot plant in Evansville, IN, which uses chlorine dioxide as a primary disinfectant. Unconventional multispectral identification techniques (gas chromatography combined with high- and low reso...

  10. The History And Future Directions Of Biosolids Disinfection

    EPA Science Inventory

    This paper reviews the history of disinfection practices, emphasizing their application to human fecal material and the residuals from wastewater treatment. It discusses development of the current US sewage sludge disinfection regulations and their associated practices; discusse...

  11. The History And Future Directions Of Biosolids Disinfection (Presentation)

    EPA Science Inventory

    This paper reviews the history of disinfection practices, emphasizing their application to human fecal material and the residuals from wastewater treatment. It discusses development of the current US sewage sludge disinfection regulations and their associated practices; discusse...

  12. Study and application of herbal disinfectants in China.

    PubMed

    Chen, Zhao-Bin

    2004-12-01

    Disinfection means killing or removing pathogenic microorganisms in media to realize a harmless process. A disinfectant, which is also referred to as a disinfection medicine in relevant regulations, is the medicine used to kill microorganisms for the purpose of disinfection. The disinfectants prepared from plants (including traditional Chinese herbal medicines) and the extracts thereof are called herbal disinfectants. China has a long history of using herbal disinfectants. As early as in 533 A.D., the use of Cornel to sterilize well water was recorded in Necessary Techniques for Qi People by Jia Enxie of the Beiwei Dynasty. During the Dragon Boat Festival, people often use fumigants made of traditional Chinese herbal medicines like Chinese Atractylodes, Argy Wormwood Leaf and Red Arsenic Sulfide to smoke their houses, so as to ward off plagues and drive away evils. In fact this is now a kind of disinfection practice. PMID:15745254

  13. DISINFECTION PROCESSES AND STABILITY REFINEMENTS TO BIOSOLIDS TREATMENT TECHNOLOGIES

    EPA Science Inventory

    This paper reviews the current US sewage sludge disinfection regulations and their associated practices; discusses the limitations of the practices; discusses the criteria employed in evaluating a new (innovative or alternative) disinfection process and both notes some processes ...

  14. PARTICLE ASSOCIATION EFFECTS ON MICROBIAL INDICATOR CONCENTRATIONS AND CSO DISINFECTION

    EPA Science Inventory

    Combined sewer overflow (CSO) and wastewater disinfection effectiveness are evaluated by measuring microbial indicator concentrations before and after disinfection. The standard techniques for quantifying indicators are membrane filtration and multiple-tube fermentation/most pro...

  15. 75 FR 54589 - Availability of an Environmental Assessment for Field Testing Foot-and-Mouth Disease Vaccine...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-08

    ... Foot-and-Mouth Disease Vaccine, Live Adenovirus Vector AGENCY: Animal and Plant Health Inspection... purpose of field testing, and then to field test, an unlicensed foot-and-mouth disease vaccine, live... field testing of this vaccine, examines the potential effects that field testing this veterinary...

  16. [Study on UV and H2O2 combined inactivation of E. coli in drinking water].

    PubMed

    Zhang, Yi-Qing; Zhou, Ling-Ling; Zhang, Yong-Ji

    2013-06-01

    The inactivation effect of E. coli with both UV irradiation and hydrogen peroxide disinfection individually and in different combination modes was investigated. The results showed that hydrogen peroxide alone caused hardly any inactivation of E. coli. Only 0.02 lg inactivation was achieved by hydrogen peroxide with concentration of 20 mg x L(-1) and contact time of 30 min. UV irradiation was able to inactivate E. coli to a certain extent. The inactivation reached 4.51 lg at a UV dose of 10 mJ x cm(-2). The combination of UV and H2O2 could significantly improve the inactivation effect and the different combination modes affected the inactivation effect. The inactivation effect of UV-H2O2 was better than that of H2O2 -UV. The inactivation was increased by 0.09, 0.35, 0.38, 0.68 lg and 0.01, 0.07, 0.14, 0.53 lg when compared to the treatment with solely UV irradiation, respectively, at UV dose of 5 mJ x cm(-2) with hydrogen peroxide at contact time of 2.5, 5, 10, 20 minutes. UV/H2O2 achieved better results than sequential disinfection. The inactivation was enhanced by 0.43 lg and 0.58 lg when compared to UV-H2O2 and H2O2-UV, respectively, at UV dose of 5 mJ x cm(-2) with hydrogen peroxide at contact time of 20 minutes. The inactivation of E. coli increased with the enhancement of UV radiation intensity.

  17. [Evaluation of surface disinfectants utilized in dentistry].

    PubMed

    Silva, Célia Regina Gonçalves e; Jorge, Antonio Olavo Cardoso

    2002-01-01

    Surface disinfection is a procedure carried out on the external parts of the dental equipment as well as on other items of the dental office. The aim of this study was to analyze the efficacy of 4 surface disinfectants utilized in dentistry: 77 degrees GL alcohol, phenolic compound (Duplofen), iodophor (PVP-I) and 77 degrees GL alcohol with 5% of chlorhexidine. Four surfaces of the equipment were analyzed in the study (the carter, the washbasin for hand-washing, the headrest of the chair and the external surface of the reflector), and the spray-wipe-spray procedure was carried out. From each surface, samples were collected by means of surface plates containing Mitis Salivarius bacitracin sucrose agar, Sabouraud Dextrose agar with chloramphenicol, MacConkey agar and blood agar, for counting mutans streptococci, Candida yeasts, gram-negative bacteria and total microorganisms, respectively (ufc/plate). The results were statistically analyzed by means of the Student's t test in order to compare the mean ufc/plate values. The most effective disinfectant was 77 degrees GL alcohol with 5% of chlorhexidine, mainly against gram-positive bacteria. Iodophor and phenolic compound were also effective in microbial reduction. 77 degrees GL alcohol was the least effective product - however, although it is not considered as a surface disinfectant, it produced, in this study, statistically significant microbial reduction after the disinfecting procedure.

  18. Trends in sterilization and disinfection procedures in orthodontic offices.

    PubMed

    Cash, R G

    1990-10-01

    The present survey is a repetition of a 1987 survey examining the sterilization/disinfection procedures of Georgia's orthodontists. The purpose of this study is to examine the trends in orthodontic sterilization/disinfection procedures. Orthodontists in Georgia have dramatically changed their sterilization and disinfection procedures. The major changes represented are greater use of protective barrier wear by doctor and staff members; increased heat sterilization methods for instruments, pliers, and handpieces; and increased disinfection of alginate impressions.

  19. Disinfection of titanium dioxide nanotubes using super-oxidized water decrease bacterial viability without disrupting osteoblast behavior.

    PubMed

    Beltrán-Partida, Ernesto; Valdez-Salas, Benjamín; Escamilla, Alan; Curiel, Mario; Valdez-Salas, Ernesto; Nedev, Nicola; Bastidas, Jose M

    2016-03-01

    Amorphous titanium dioxide (TiO2) nanotubes (NTs) on Ti6Al4V alloy were synthesized by anodization using a commercially available super-oxidized water (SOW). The NT surfaces were sterilized by ultraviolet (UV) irradiation and disinfected using SOW. The adhesion and cellular morphology of pig periosteal osteoblast (PPO) cells and the behavior of Staphylococcus aureus (S. aureus) cultured on the sterilized and disinfected surfaces were investigated. A non-anodized Ti6Al4V disc sterilized by UV irradiation (without SOW) was used as control. The results of this study reveal that the adhesion, morphology and filopodia development of PPO cells in NTs are dramatically improved, suggesting that SOW cleaning may not disrupt the benefits obtained by NTs. Significantly decreased bacterial viability in NTs after cleaning with SOW and comparing with non-cleaned NTs was seen. The results suggest that UV and SOW could be a recommendable method for implant sterilization and disinfection without altering osteoblast behavior while decreasing bacterial viability.

  20. An insight of disinfection by-product (DBP) formation by alternative disinfectants for swimming pool disinfection under tropical conditions.

    PubMed

    Yang, Linyan; Schmalz, Christina; Zhou, Jin; Zwiener, Christian; Chang, Victor W-C; Ge, Liya; Wan, Man Pun

    2016-09-15

    Sodium hypochlorite (NaClO) is the most commonly used disinfectant in pool treatment system. Outdoor pools usually suffer from the strong sunlight irradiation which degrades the free chlorine rapidly. In addition, more pools start to adopt the recirculation of swimming pool water, which intensifies the disinfection by-product (DBP) accumulation issue. Given these potential drawbacks of using NaClO in the tropical environment, two alternative organic-based disinfectants, trichloroisocyanuric acid (TCCA, C3Cl3N3O3) and bromochlorodimethylhydantoin (BCDMH, C5H6BrClN2O2), were investigated and compared to NaClO in terms of their self-degradation and the formation of DBPs, including trihalomethanes (THMs) and haloacetic acids (HAAs), under simulated tropical climate conditions. The result reveals that halogen stabilizer, TCCA, had the advantages of slower free chlorine degradation and lower DBP concentration compared to NaClO, which makes it a good alternative disinfectant. BCDMH was not recommended mainly due to the highly reactive disinfecting ingredient, hypobromous acid (HBrO), which fails to sustain the continuous disinfection requirement. Total disinfectant dosage was the main factor that affects residual chlorine/bromine and THM/HAA formation regardless of different disinfectant dosing methods, e.g. shock dosing (one-time spiking) in the beginning, and continuous dosing during the whole experimental period. Two-stage second-order-kinetic-based models demonstrate a good correlation between the measured and predicted data for chlorine decay (R(2) ≥ 0.95), THM (R(2) ≥ 0.99) and HAA (R(2) ≥ 0.83) formation. Higher temperature was found to enhance the DBP formation due to the temperature dependence of reaction rates. Thus, temperature control of pools, especially for those preferring higher temperatures (e.g. hydrotherapy and spa), should take both bather comfort and DBP formation potential into consideration. It is also observed that chlorine competition

  1. Integrated Disinfection By-Products Mixtures Research: Disinfection of Drinking Waters by Chlorination and Ozonation/Postchlorination Treatment Scenarios

    EPA Science Inventory

    This article describes disinfection of the same source water by two commonly used disinfection treatment scenarios for purposes of subsequent concentration, chemical analysis, and toxicological evaluation. Accompanying articles in this issue of the Journal of Toxicology and Envir...

  2. Studies on Disinfection By-Products and Drinking Water

    USGS Publications Warehouse

    Rostad, Colleen E.

    2007-01-01

    Drinking water is disinfected with chemicals to remove pathogens, such as Giardia and Cryptosproridium, and prevent waterborne diseases such as cholera and typhoid. During disinfection, by-products are formed at trace concentrations. Because some of these by-products are suspected carcinogens, drinking water utilities must maintain the effectiveness of the disinfection process while minimizing the formation of by-products.

  3. MODELING DISINFECTANT RESIDUALS IN DRINKING-WATER STORAGE TANKS

    EPA Science Inventory

    The factors leading to the loss of disinfectant residual in well-mixed drinking-water storage tanks are studied. Equations relating disinfectant residual to the disinfectant's reation rate, the tank volume, and the fill and drain rates are presented. An analytical solution for ...

  4. Proteomic Adaptations to Starvation Prepare Escherichia coli for Disinfection Tolerance

    PubMed Central

    Du, Zhe; Nandakumar, Renu; Nickerson, Kenneth; Li, Xu

    2015-01-01

    Despite the low nutrient level and constant presence of secondary disinfectants, bacterial re-growth still occurs in drinking water distribution systems. The molecular mechanisms that starved bacteria use to survive low-level chlorine-based disinfectants are not well understood. The objective of this study is to investigate these molecular mechanisms at the protein level that prepare starved cells for disinfection tolerance. Two commonly used secondary disinfectants chlorine and monochloramine, both at 1 mg/L, were used in this study. The proteomes of normal and starved Escherichia coli (K12 MG1655) cells were studied using quantitative proteomics. Over 60-min disinfection, starved cells showed significantly higher disinfection tolerance than normal cells based on the inactivation curves for both chlorine and monochloramine. Proteomic analyses suggest that starvation may prepare cells for the oxidative stress that chlorine-based disinfection will cause by affecting glutathione metabolism. In addition, proteins involved in stress regulation and stress responses were among the ones up-regulated under both starvation and chlorine/monochloramine disinfection. By comparing the fold changes under different conditions, it is suggested that starvation prepares E. coli for disinfection tolerance by increasing the expression of enzymes that can help cells survive chlorine/monochloramine disinfection. Protein co-expression analyses show that proteins in glycolysis and pentose phosphate pathway that were up-regulated under starvation are also involved in disinfection tolerance. Finally, the production and detoxification of methylglyoxal may be involved in the chlorine-based disinfection and cell defense mechanisms. PMID:25463932

  5. THE TOXICOLOGY OF COMPLEX MIXTURES OF DISINFECTION BY-PRODUCTS

    EPA Science Inventory

    Chemical disinfection of water is a major public health advance that has decreased dramatically water-borne disease. Chemical disinfectants react with naturally occurring organic and inorganic matter in water to produce a wide variety of disinfection byproducts (DBPs). DBP num...

  6. A Toxicological Perspective on Disinfection ByProducts

    EPA Science Inventory

    Disinfection of water is essential for reduction of microbes harmful to human health and chemical disinfection is considered one of the major public health triumphs of the 20th Century. An unintended consequence of disinfection with oxidizing chemicals is formation of disinfectio...

  7. 21 CFR 880.6890 - General purpose disinfectants.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false General purpose disinfectants. 880.6890 Section... Miscellaneous Devices § 880.6890 General purpose disinfectants. (a) Identification. A general purpose disinfectant is a germicide intended to process noncritical medical devices and equipment surfaces. A...

  8. 21 CFR 880.6890 - General purpose disinfectants.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false General purpose disinfectants. 880.6890 Section... Miscellaneous Devices § 880.6890 General purpose disinfectants. (a) Identification. A general purpose disinfectant is a germicide intended to process noncritical medical devices and equipment surfaces. A...

  9. 21 CFR 880.6890 - General purpose disinfectants.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false General purpose disinfectants. 880.6890 Section... Miscellaneous Devices § 880.6890 General purpose disinfectants. (a) Identification. A general purpose disinfectant is a germicide intended to process noncritical medical devices and equipment surfaces. A...

  10. 21 CFR 880.6890 - General purpose disinfectants.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false General purpose disinfectants. 880.6890 Section... Miscellaneous Devices § 880.6890 General purpose disinfectants. (a) Identification. A general purpose disinfectant is a germicide intended to process noncritical medical devices and equipment surfaces. A...

  11. 21 CFR 880.6890 - General purpose disinfectants.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false General purpose disinfectants. 880.6890 Section... Miscellaneous Devices § 880.6890 General purpose disinfectants. (a) Identification. A general purpose disinfectant is a germicide intended to process noncritical medical devices and equipment surfaces. A...

  12. Environmental health perspectives. Volume 46. Drinking water disinfectants - December 1982

    SciTech Connect

    Lucier, G.W.; Hook, G.E.R.

    1982-01-01

    Among subjects considered are chlorine dioxide, N-chloramines, mutagenic activity by disinfectant reaction products, trihalomethane and behavioral toxicity, and carcinogenic risk estimation. There are 27 papers on these and related topics. The volume stems from a symposium on drinking water disinfectants and disinfectant by-products.

  13. OPTIMAL SCHEDULING OF BOOSTER DISINFECTION IN WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Booster disinfection is the addition of disinfectant at locations distributed throughout a water distribution system. Such a strategy can reduce the mass of disinfectant required to maintain a detectable residual at points of consumption in the distribution system, which may lea...

  14. 9 CFR 91.41 - Cleaning and disinfecting of aircraft.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Cleaning and disinfecting of aircraft... INSPECTION AND HANDLING OF LIVESTOCK FOR EXPORTATION Cleaning and Disinfecting of Aircraft § 91.41 Cleaning and disinfecting of aircraft. Prior to loading of animals, the stowage area of aircraft to be used...

  15. 9 CFR 91.41 - Cleaning and disinfecting of aircraft.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Cleaning and disinfecting of aircraft... INSPECTION AND HANDLING OF LIVESTOCK FOR EXPORTATION Cleaning and Disinfecting of Aircraft § 91.41 Cleaning and disinfecting of aircraft. Prior to loading of animals, the stowage area of aircraft to be used...

  16. 9 CFR 91.41 - Cleaning and disinfecting of aircraft.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Cleaning and disinfecting of aircraft... INSPECTION AND HANDLING OF LIVESTOCK FOR EXPORTATION Cleaning and Disinfecting of Aircraft § 91.41 Cleaning and disinfecting of aircraft. Prior to loading of animals, the stowage area of aircraft to be used...

  17. Evaluation of disinfection techniques in the treatment of advanced primary treated wastewater for Ciudad Juárez, México.

    PubMed

    Carrasco, Leirad; Turner, Charles D

    2006-01-01

    The purpose of this study was to develop and evaluate the effectiveness of alternative disinfection techniques at the bench-scale level using wastewater from Ciudad Juarez, Mexico, as model feed. This paper presents findings on the effectiveness of UV radiation, peracetic acid (PAA), chlorine dioxide (ClO2), and hypochlorous acid (HOCl) as disinfectants for advanced primary treatment (APT) plant effluent. Wastewater samples for bench-scale testing were collected from an agua negra ("black water") ditch that is part of the combined sewer system in Ciudad Juarez. Bench-scale simulations of the APT process used in Ciudad Juarez were run using a jar test apparatus and aluminum sulfate [Al2(SO4)3] as the coagulant. Jar test effluent from the bench system was used for disinfection testing. The Mexican discharge quality standard for total coliforms is 10 000/100 mL. Ultraviolet radiation met this standard at a dose of 47.5 mW-s/cm2. Ultraviolet disinfection proved reliable and effective despite the presence of suspended solids, and UV dose effectiveness expressed as a total coliforms survival ratio was best explained by a linear regression model. The ClO2 dose ranged from 10 to 20 mg/L and was only effective under ambient temperature conditions found during the winter months; PAA disinfection never met Mexican standards. Chlorine disinfection was effective at a dose range of 8 to 10 mg/L on samples collected at low temperature conditions. Since the completion of this research, Ciudad Juarez has discontinued the use of chlorine disinfection because of its high cost and ineffectiveness.

  18. Increased formation of halomethanes during chlorination of chloramphenicol in drinking water by UV irradiation, persulfate oxidation, and combined UV/persulfate pre-treatments.

    PubMed

    Wenhai, Chu; Tengfei, Chu; Erdeng, Du; Deng, Yang; Yingqing, Guo; Naiyun, Gao

    2016-02-01

    Ultraviolet/persulfate (UV/PS) has been widely used to generate sulfate radicals for degradation of water organic pollutants in previous studies. However, its impacts on disinfection byproduct formation during post-chlorination of degraded compounds is unclear. The objective of this study was to evaluate the impacts of UV irradiation, PS oxidation, and the combined UV/PS advanced oxidation process (AOP) pre-treatments on halomethane formation during the following chlorination of chloramphenicol (CAP), a model antibiotic commonly found in wastewater-impacted water. Results showed that CAP could be transformed to more trichloromethane (TCM) than monochloromethane (MCM) and dichloromethane (DCM) in the presence of excess chlorine. UV photolysis, PS oxidation and UV/PS AOP all directly decomposed CAP to produce halomethanes (HMs) before post-chlorination. Moreover, UV and UV/PS pre-treatments both enhanced the formation of all the HMs in the subsequent chlorination. PS pre-oxidation decreased the TCM formation during post-chlorination, but increased the yields of MCM, DCM and total HMs. UV pre-irradiation significantly increased the bromide utilization of HMs, whereas UV/PS pre-oxidation decreased the bromine incorporation and utilization of HMs from the chlorination of CAP in a low-bromide water. UV irradiation, PS oxidation, and UV/PS AOP can inactivate pathogens and degrade organic pollutants, but this benefit should be weighed against a potential risk of the increased halomethane formation from degraded organic pollutants with and without post-chlorination.

  19. Evaluation of reflection and refraction in simulations of ultraviolet disinfection using the discrete ordinates radiation model.

    PubMed

    Ho, C K

    2009-01-01

    Simulations of UV disinfection systems require accurate models of UV radiation within the reactor. Processes such as reflection and refraction at surfaces within the reactor can impact the intensity of the simulated radiation field, which in turn impacts the simulated dose and performance of the UV reactor. This paper describes a detailed discrete ordinates radiation model and comparisons to a test that recorded the UV radiation distribution around a low pressure UV lamp in a water-filled chamber with a UV transmittance of 88%. The effects of reflection and refraction at the quartz sleeve were investigated, along with the impact of wall reflection from the interior surfaces of the chamber. Results showed that the inclusion of wall reflection improved matches between predicted and measured values of incident radiation throughout the chamber. The difference between simulations with and without reflection ranged from several percent near the lamp to nearly 40% further away from the lamp. Neglecting reflection and refraction at the quartz sleeve increased the simulated radiation near the lamp and reduced the simulated radiation further away from the lamp. However, the distribution and trends in the simulated radiation field both with and without the effects of reflection and refraction at the quartz sleeve were consistent with the measured data distributions.

  20. Evaluation of reflection and refraction in simulations of ultraviolet disinfection using the discrete ordinates radiation model.

    PubMed

    Ho, C K

    2009-01-01

    Simulations of UV disinfection systems require accurate models of UV radiation within the reactor. Processes such as reflection and refraction at surfaces within the reactor can impact the intensity of the simulated radiation field, which in turn impacts the simulated dose and performance of the UV reactor. This paper describes a detailed discrete ordinates radiation model and comparisons to a test that recorded the UV radiation distribution around a low pressure UV lamp in a water-filled chamber with a UV transmittance of 88%. The effects of reflection and refraction at the quartz sleeve were investigated, along with the impact of wall reflection from the interior surfaces of the chamber. Results showed that the inclusion of wall reflection improved matches between predicted and measured values of incident radiation throughout the chamber. The difference between simulations with and without reflection ranged from several percent near the lamp to nearly 40% further away from the lamp. Neglecting reflection and refraction at the quartz sleeve increased the simulated radiation near the lamp and reduced the simulated radiation further away from the lamp. However, the distribution and trends in the simulated radiation field both with and without the effects of reflection and refraction at the quartz sleeve were consistent with the measured data distributions. PMID:19542648