WorldWideScience

Sample records for radiation disinfected dates

  1. Disinfecting wounds with radiation

    International Nuclear Information System (INIS)

    Cuttler, J.M.

    2002-01-01

    Infection with clostridium bacteria, which live in the soil, is most often associated with war wounds, car accidents, complicated abortions, etc. The incidence is highest in areas with poor access to proper wound care. Such infections lead to gas gangrene, a deadly disease that spreads very quickly in the body and causes rapid death. Present-day treatment consists of administering antibiotics and surgical removal of dead, damaged and infected tissue. Amputation is usually necessary to control the spread of the infection, which can advance at the rate of six inches per hour. Before the 1940s, this disease was treated successfully with low doses (50 rad) of radiation (X-rays) in the area of infection. A review of 364 cases treated in this manner, from 1928 until 1940, indicated that patient mortality would be reduced from 50 percent (or higher) to ∼5 percent if patients were treated reasonably early and with the correct technique. X-ray therapy stopped the infection without the need for amputation to control its spread. Low-dose irradiation (LDI) therapy, given immediately, acted as a prophylaxis to prevent the onset of gas gangrene. This is but one example of the extensive use of radiation treatment of many types of infections, before the advent of antibiotics. Low doses are inadequate to kill invading bacteria directly, however, they will stimulate our defences to destroy the infection. The observed beneficial effects are consistent with the large amount of scientific evidence of radiation hormesis - the stimulation of an organism's own defences by low doses of radiation (to destroy invaders and heal wounds). In view of the ineffectiveness of antibiotics in many cases and the evolution of antibiotic-resistant strains of bacteria, physicians should start to use LDI therapies again. Many patients would benefit greatly. (author)

  2. Enhanced composting of radiation disinfected sewage sludge

    International Nuclear Information System (INIS)

    Kawakami, W.; Hashimoto, S.

    1984-01-01

    Studies on isothermal composting of radiation disinfected sewage sludge and liquid chromatography of water extracts of the products were carried out. The optimum temperature and pH were around 50 deg C and 7 to 8, respectively. The repeated use of products as seeds increased the rate of CO 2 evolution. The rate reached a maximum within 10 hours and decreased rapidly, and the CO 2 evolution ceased after about 3 days. The conversion of organic carbon to carbon dioxide attained to about 40% for the repeated use of products as seeds at the optimum conditions. As long as seeds as available were used, no remarkable difference was found in the composting of unirradiated and irradiated sludges. The composting process using radiation, however, can be carried out at the optimum conditions and is expected to shorten the composting period, because it is not necessary to keep fermentation temperature higher to reduce pathogen in sludge. Liquid chromatographic studies of the products showed that low molecular components decreased and higher molecular ones increased with fermentation. An index expressing the degree of reduction of easily decomposable organics was presented. The index also showed that the optimum temperature for fermentation was 50 deg C. (author)

  3. Composting of gamma-radiation disinfected sewage sludge

    International Nuclear Information System (INIS)

    Kawakami, W.; Hashimoto, S.; Watanabe, H.; Nishimura, K.; Watanabe, H.; Ito, H.; Takehisa, M.

    1981-01-01

    The composting of radiation disinfected sewage sludge has been studied since 1978, aiming to present a new process of sludge composting for agricultural uses. This process is composed of two steps: irradiation step to disinfect sludge, and composting step to remove odor and easily decomposable organics in sludge. In this paper, the gamma-irradiation effect on sludge cake and composting condition of irradiated sludge are discussed. (author)

  4. Drinking water disinfection by means of ultraviolet radiation

    International Nuclear Information System (INIS)

    Gelzhaeuser, P.; Bewig, F.; Holm, K.; Kryschi, R.; Reich, G.; Steuer, W.

    1985-01-01

    The book presents all lectures held during a course at Technical Academy Esslingen, on September 10, 1985, on the subject of 'Drinking water disinfection by means of ultraviolet radiation'. The methods hitherto used for disinfection are no longer suitable because of the increasing amounts of organic pollutants found in the untreated water, and because of the necessity to make drinking water disinfection less expensive, non-polluting and thus environmentally compatible. U.V. irradiation is a method allowing technically simple and safe disinfection of the water, and also does not have any effect on the natural taste of the drinking water. The lectures presented discuss all aspects of the method, the equipment, and the performance of irradiation systems in practice. (orig./PW) [de

  5. Disinfection ultraviolet radiation bulk food products

    OpenAIRE

    Семенов, А. А.

    2014-01-01

    В работе представлены результаты обеззараживания сыпучих пищевых продуктов ультрафиолетовым излучением. Предложена технология бактерицидного обеззараживания сыпучих продуктов с размером частиц до 50 мкм. Проведены необходимые расчеты, связанные с дозой облучения, с временем пребывания частиц в зоне облучения и необходимой дозой инактивации в зависимости от вида бактерий. Considered the results of bulk food products disinfection by ultraviolet radiation. The technology bactericidal disinfec...

  6. Radiation disinfection of sewage sludge and composting of the irradiated sludge

    International Nuclear Information System (INIS)

    Hashimoto, Shoji; Nishimura, Koichi; Watanabe, Hiromasa; Kawakami, Waichiro

    1985-01-01

    In the radiation disinfected sewage sludge, its stabilization is necessary with the composting. In this disinfected sludge, there is no need of keeping it at high temperature at the cost of fermentation velocity. The fermentation velocity can thus be set to obtain its maximum value. In sewage sludge utilization of farm land, to prevent the contamination with pathogenic bacteria and the secondary pollution, the radiation disinfection of dehydrated sludge and the composting of the disinfected sludge have been studied. The disinfection effect when an electron accelerator is used for the radiation source is described. Then, the composting of the disinfected sludge is described in chemical kinetics of the microorganisms. (Mori, K.)

  7. The efficiency of water treatment and disinfection by means of ultraviolet radiation

    International Nuclear Information System (INIS)

    Sobotka, J.

    1993-01-01

    Advantages and disadvantages of various water disinfection methods are discussed. The report examines the effectiveness of combined chlorine treatment and UV irradiation method of water disinfection and describes methods of determining UV radiation intensity, α absorption coefficient and radiation dose by means of measuring equipment constructed by the author. The α absorption coefficient dependence on the colour and turbidity of water exposed to radiation is defined. Enchytraeus albidus was applied as bioindicator in UV radiation intensity and disinfection effects measurements. The influence of UV radiation on microbiological, physical, chemical, and toxicological properties of water was determined. Prototype devices for water disinfection with UV radiation were made. (author)

  8. The efficiency of water treatment and disinfection by means of ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sobotka, J [Medical Academy, Warsaw (Poland). Inst. of Social Medicine

    1993-01-01

    Advantages and disadvantages of various water disinfection methods are discussed. The report examines the effectiveness of combined chlorine treatment and UV irradiation method of water disinfection and describes methods of determining UV radiation intensity, [alpha] absorption coefficient and radiation dose by means of measuring equipment constructed by the author. The [alpha] absorption coefficient dependence on the colour and turbidity of water exposed to radiation is defined. Enchytraeus albidus was applied as bioindicator in UV radiation intensity and disinfection effects measurements. The influence of UV radiation on microbiological, physical, chemical, and toxicological properties of water was determined. Prototype devices for water disinfection with UV radiation were made. (author).

  9. Annual radiation dose in thermoluminescence dating

    International Nuclear Information System (INIS)

    Li Huhou

    1988-01-01

    The annual radiation dose in thermoluminescence dating has been discussed. The autor gives an entirely new concept of the enviromental radiation in the thermoluminescence dating. Methods of annual dose detemination used by author are dating. Methods of annual dose determination used by author are summed up, and the results of different methods are compared. The emanium escapiug of three radioactive decay serieses in nature has been considered, and several determination methods are described. The contribution of cosmic rays for the annual radiation dose has been mentioned

  10. Annual radiation dose in thermoluminescence dating

    Energy Technology Data Exchange (ETDEWEB)

    Huhou, Li [Chinese Academy of Social Sciences, Beijing, BJ (China). Inst. of Archaeology

    1988-11-01

    The annual radiation dose in thermoluminescence dating has been discussed. The autor gives an entirely new concept of the enviromental radiation in the thermoluminescence dating. Methods of annual dose detemination used by author are dating. Methods of annual dose determination used by author are summed up, and the results of different methods are compared. The emanium escapiug of three radioactive decay serieses in nature has been considered, and several determination methods are described. The contribution of cosmic rays for the annual radiation dose has been mentioned.

  11. Ultraviolet radiation as disinfection for fish surgical tools

    Energy Technology Data Exchange (ETDEWEB)

    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

  12. Disinfection of sewage water and sludge using gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Musaad, R M.A. [Department of Radiation Chemistry, Atomic Energy Research Coordination Council, Sudan Academy of Sciences, Khartoum (Sudan)

    2008-04-15

    This study has been carried out to assess the efficiency of gamma radiation in disinfecting sewage water and sludge from harmful pathogenic bacteria (e.g. Streptococcus, Salmonella, Shigella, total E-coli and total coliform), parasites (Ascaris ova) as well as its ability to degrade organic matter (BOD). Samples were exposed to gamma-radiation doses ranging from 0.5 to 8 KGy using Co''6{sup 0} cell. Amongst pathogenic bacteria which are subjected to different doses of gamma-radiation Streptococcus faecalis revealed to be the most resistance bacterial indicator since complete elimination of these bacteria could be attained at 3.5 KGy. While total e-coli shown to be the most sensitive with lethal dose at 2 KGy. The radiation doses that required for reducing the bacterial population by 90% (D{sub 10}) and 50% (D {sub 50}) were determined for each species. The D{sub 10} values found ranged from 0.75 KGy for Streptococcus and 2.75 KGy for total count bacteria. On the other hand, D{sub 50} fall within the range of 0.5 KGy for total count bacteria, total coliform and Streptococcus, and 1.0 KGy for total e-coli. With regard to the efficiency of radiation treatment to destroy Ascaris ova viability it was found that no larvae were viable after exposure to 1.0 KGy following incubation of exposed ova for four weeks period.(Author)

  13. Disinfection of sewage water and sludge using gamma radiation

    International Nuclear Information System (INIS)

    Musaad, R.M.A.

    2008-04-01

    This study has been carried out to assess the efficiency of gamma radiation in disinfecting sewage water and sludge from harmful pathogenic bacteria (e.g. Streptococcus, Salmonella, Shigella, total E-coli and total coliform), parasites (Ascaris ova) as well as its ability to degrade organic matter (BOD). Samples were exposed to gamma-radiation doses ranging from 0.5 to 8 KGy using Co''6 0 cell. Amongst pathogenic bacteria which are subjected to different doses of gamma-radiation Streptococcus faecalis revealed to be the most resistance bacterial indicator since complete elimination of these bacteria could be attained at 3.5 KGy. While total e-coli shown to be the most sensitive with lethal dose at 2 KGy. The radiation doses that required for reducing the bacterial population by 90% (D 10 ) and 50% (D 50 ) were determined for each species. The D 10 values found ranged from 0.75 KGy for Streptococcus and 2.75 KGy for total count bacteria. On the other hand, D 50 fall within the range of 0.5 KGy for total count bacteria, total coliform and Streptococcus, and 1.0 KGy for total e-coli. With regard to the efficiency of radiation treatment to destroy Ascaris ova viability it was found that no larvae were viable after exposure to 1.0 KGy following incubation of exposed ova for four weeks period.(Author)

  14. Radiation disinfection of manure for animal feed supplement

    International Nuclear Information System (INIS)

    Harsojo; Andini, S.; Nazly, H.; Suwirma, S.; Danius, J.

    1989-01-01

    Radiation disinfection of manure for animal feed supplement. Radiation treatment for disinfection of manure have been investigated on manure collected during the dry and rainy seasons. Total bacterial counts of non-irradiated dewatered manure with water content of around 13.44% were found to be 1.0x10 6 up to 1.4x10 8 per g during the dry season, and 2.0x10 5 up to 1.7x10 7 per g during the rainy season, while coliforms, enterobecteriacease, staphylococcus, streptococcus, and pseudomonas were found to be 1.0x10 6 up to 1.4x10 8 per g, 1.0x10 4 up to 1.2x10 6 per g, 4.0x10 5 up to 2.2x10 7 per g, 1.8x10 3 per g, and 1.0x10 2 up to 5.4x10 3 per g, respectively. About 30% of the total coliforms were found to be escherichia coli. Irradiation dose of 4 kGy eliminated salmonella from all samples observed. No. Shigella Vibrio, and parasites were detected in the samples. Total nitrogen of the dewatered manure ranged between 1.87 and 2.33%, phosphorus between 1.25 and 4.38%, and potassium between 0.66 and 2.18%. Heavy metal elements were found only in very small amounts, hence the dewatered manure could be applied as animal feed or soil conditioner. A combination of irradiation at 4 kGy and storage for 3 months was synergistically effective to eliminate coliform, E. coli, and salmonella in the dewatered manure. From nutritional point of view, the manure is still acceptable for animal feed supplement. (author). 13 refs

  15. Dating ancient monuments by nuclear radiation

    International Nuclear Information System (INIS)

    Goedicke, C.

    2000-01-01

    In the fifties and sixties several disciplines dealing with chronologies but lacking precise methods of measurements (geology, biology, archaeology and art history) became aware of the radioactive decay as a tool of measuring elapsed time. Among the disciplines that benefit most from physical methods archaeology has to be named first. So was archaeological work revolutionised by the introduction of the C-14 dating method. A wider selection of material became datable after the introduction of luminescence techniques using the effect of nuclear radiation on semiconductors. These minerals are widespread among archaeological materials. In ancient monuments, the objective of this paper, semiconductors almost exclusively form the material basis. Over the last four millennia wood, stone, mortar and fired bricks have been used for the construction of buildings. After discussing methods taking wood as a dating material, a broader view will be given on the results achieved by luminescence dating of fired bricks, mortar and stone. For many years brick dating was performed by thermoluminescence, the recipes followed those of ceramic dating. Preferably multiple aliquot additive dose protocols were used on polymineral fine grain fractions (1-10 μm). It was expected that the error in dating monuments would be smaller compared to ceramic dating, because of the constancy of the environmental conditions which a brick experiences during its lifetime. However, the variability of firing temperatures in brick kilns overthrows this advantage. Therefore, the demands of art historians to fall short of an error margin of 5% could generally not be fulfilled. Especially in medieval or renaissance times the temporal resolution of thermoluminescence is inferior to traditional stylistic dating as long as specific stylistic forms are present. New optical luminescence techniques and a new philosophy of dose evaluation, based on single aliquot regeneration protocols, produce less scatter, and in

  16. Role of radiation dating technique - one example

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Shigueo [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica; Etchevarne, Carlos A. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Fac. de Filosofia e Ciencias Humanas. Dept. Antropologia e Etnologia; Cano, Nilo F.; Munita, C.S. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2012-07-01

    Full text: The great majority of archaeological or geological dating technique is based on radiation effect. The so called radioactivity method uses radioactive decays of elements. This is the case of the well known radiocarbon or carbon-14 method. Also the method of relating daughter nucleus to decaying nucleus, as in K-40/Ar-40, Th- 230/U-234, etc. Here we will concentrate in the method based on energy deposition in a solid by radiation from the disintegration of U-series and Th-series. {beta}-rays emitted by the decay of K-40 into Ca-40 (80%) and Ar-40 (11%) also contributes. The role of {alpha}, {beta} and {gamma} radiation emitted by radionuclides in the U-238 and Th-232 series and of {beta} rays from the decay of K-40, all of them in the soil irradiate anything in their course. For dating, we can have sediments as well as potteries produced by ancient people and became buried. The important process consists in transferring a fraction of the energy of radiation to the solid, mainly liberating electrons from valence band to conduction band and from there to traps. In many case the energy of the radiation is used to create defects which in turn create energy levels (traps) in the forbidden gap (or energy gap). There are three ways to recover the energy stored in the solid: (1) by emission of light optically stimulated (OSL), (2) by emission of light thermally stimulated (TL), (3) by microwave absorption (EPR or ESR). Using these techniques among several applications, we will present one to find the first settlers in the northeaster region of Brazil. (author)

  17. Role of radiation dating technique - one example

    International Nuclear Information System (INIS)

    Watanabe, Shigueo

    2012-01-01

    Full text: The great majority of archaeological or geological dating technique is based on radiation effect. The so called radioactivity method uses radioactive decays of elements. This is the case of the well known radiocarbon or carbon-14 method. Also the method of relating daughter nucleus to decaying nucleus, as in K-40/Ar-40, Th- 230/U-234, etc. Here we will concentrate in the method based on energy deposition in a solid by radiation from the disintegration of U-series and Th-series. β-rays emitted by the decay of K-40 into Ca-40 (80%) and Ar-40 (11%) also contributes. The role of α, β and γ radiation emitted by radionuclides in the U-238 and Th-232 series and of β rays from the decay of K-40, all of them in the soil irradiate anything in their course. For dating, we can have sediments as well as potteries produced by ancient people and became buried. The important process consists in transferring a fraction of the energy of radiation to the solid, mainly liberating electrons from valence band to conduction band and from there to traps. In many case the energy of the radiation is used to create defects which in turn create energy levels (traps) in the forbidden gap (or energy gap). There are three ways to recover the energy stored in the solid: (1) by emission of light optically stimulated (OSL), (2) by emission of light thermally stimulated (TL), (3) by microwave absorption (EPR or ESR). Using these techniques among several applications, we will present one to find the first settlers in the northeaster region of Brazil. (author)

  18. Utilization of ultraviolet radiation of cold hollow cathode discharge plasma for water disinfection

    International Nuclear Information System (INIS)

    Soloshenko, I.O.; Bazhenov, V.Yu.; Khomych, V.O.; Tsiolko, V.V.; Potapchenko, N.G.; Goncharuk, V.V.

    2006-01-01

    We study the possibility to use the ultraviolet radiation of a hollow cathode discharge plasma for water disinfection. We have performed the comparative experiments on the influence of ultraviolet radiation of the mentioned discharge plasma, as well as that of a standard low pressure mercury lamp

  19. Effect of Gamma Radiation sterilization versus Disinfection on Removable Partial Dentures (Microbiological study)

    International Nuclear Information System (INIS)

    Mohammed, M.A.

    2011-01-01

    The aim of the study was to compare between the effectiveness of disinfection, using commercially available Fittydent super cleansing tablets versus sterilization, using gamma radiation on candidal growth in maxillary removable partial dentures. Methods: Fourteen partially edentulous subjects were selected according to specific criteria and divided equally and randomly into two groups; Group I: disinfection group and Group II: sterilization group. Conventional maxillary removable partial dentures were constructed for all subjects. The swab technique was used to collect the samples one month after denture delivery, immediately after disinfection/sterilization, and then one week, two weeks, three weeks, four weeks, and five weeks after disinfection/sterilization respectively. Bacteriological candidal colony count was performed using a manual contact colony counter. Results: Both methods (disinfection and sterilization) led to a noticeable decrease in the candidal count. However this decrease was highly and markedly evident in Group II as compared to Group I. Infact, no candidal growth was recorded for group II immediately after strerilization and was maintained for two more weeks. Statistical analysis revealed highly significant differences between the two groups. Conclusions: Both methods were effective in decreasing the number of Candida albicans adhering to the denture. However, sterilization using Gamma radiation had a more superior immediate, as well as, long term efficiency as compared to disinfection using Fittydent super cleansing tablets.

  20. Drinking water disinfection by means of ultraviolet radiation. Desinfektion von Trinkwasser durch UV-Bestrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Gelzhaeuser, P; Bewig, F; Holm, K; Kryschi, R; Reich, G; Steuer, W

    1985-01-01

    The book presents all lectures held during a course at Technical Academy Esslingen, on September 10, 1985, on the subject of 'Drinking water disinfection by means of ultraviolet radiation'. The methods hitherto used for disinfection are no longer suitable because of the increasing amounts of organic pollutants found in the untreated water, and because of the necessity to make drinking water disinfection less expensive, non-polluting and thus environmentally compatible. U.V. irradiation is a method allowing technically simple and safe disinfection of the water, and also does not have any effect on the natural taste of the drinking water. The lectures presented discuss all aspects of the method, the equipment, and the performance of irradiation systems in practice.

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

    Science.gov (United States)

    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.

  2. Synergistic effect of solar radiation and solar heating to disinfect drinking water sources.

    Science.gov (United States)

    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 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 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 disinfection was observed even when the water temperature did not reach 60 degrees C. Finally, the hydrogen sulphide test is a simple and reliable test that householders can use to determine whether their water had been sufficiently disinfected.

  3. Sludge disinfection using gamma radiation: a sound option for Albuquerque

    International Nuclear Information System (INIS)

    Noland, P.D.; Khera, A.K.

    1980-01-01

    The City of Albuquerque has disposed of its anaerobically digested dried sludge cake on City and county parks for many years. If the City is to continue such beneficial use of sludge, it must now provide a supplementary disinfection process in order to meet the recent EPA regulations governing land application of sewage sludges. In light of these recent regulations and soaring costs of electrical energy, the City of Albuquerque recently completed a comprehensive sludge management study. This study is intended to supplement the areawide facilities plan completed in 1976. Among the various alternatives evaluated, the most feasible was the continued use of dried sludge cake on City parks and sale of excess sludge cake as an unlimited use soil conditioner and fertilizer. This sludge would be disinfected by gamma irradiation. The proposed solids management system would consist of two-stage anaerobic digestion and pipeline transfer to dewatering, disinfection, and stockpiling facilities at a remote tract approximately 5 miles from the treatment plant

  4. Isolation of Bacillus subtilis as indicator in the disinfection of residual water by means of gamma radiation

    International Nuclear Information System (INIS)

    Mata J, M.; Colin C, A.; Lopez V, H.; Brena V, M.; Carrasco A, H.; Pavon R, S.

    2002-01-01

    In the attempt to get more alternatives of disinfection of residual water, the Bacillus subtilis was isolated by means of gamma radiation as a bio indicator of disinfection since it turned out to be resistant to the 5 KGy dose, comparing this one with other usual microorganisms as biondicators like E. coli and S typhimurium which turn out more sensitive to such dose. (Author)

  5. Microwave radiation is effective at disinfecting dental stone surfaces without changing their physical properties.

    Science.gov (United States)

    Bona, Ariel José; Amaral-Brito, Mauro Gustavo; Rodrigues, José Augusto; Peruzzo, Daiane Cristina; França, Fabiana Mantovani Gomes

    2017-01-01

    The aims of this study were to evaluate the effectiveness of different microwave radiation regimens for disinfection of type IV dental stone surfaces and to assess the influence of these regimens on surface roughness and dimensional change following disinfection. Three hundred cylindrical (20 × 2-mm) test specimens were made in type IV stone and divided into subgroups of 20 according to the microorganisms tested (Staphylococcus aureus, Escherichia coli, or Candida albicans) and the 900-W microwave radiation protocol (cycles of 3, 5, or 7 minutes; a positive control; or a negative control). To test physical changes, 80 test specimens were made with the same dimensions except that they had 2 parallel and symmetrical indentations measuring 8 × 4 mm. These specimens were divided into 4 subgroups of 20 each (a subgroup for each radiation time and a negative control). The mean dimensional change and roughness data were analyzed by mixed models for repeated measures and Tukey-Kramer tests. Disinfection was analyzed with descriptive statistics. For E coli and C albicans, all radiation times proved effective at sterilizing the test specimens. For S aureus, sterilization was achieved with 5 and 7 minutes of exposure; however, colonies were observed in 10 Petri dishes (50%) exposed to 3 minutes of microwave radiation. No statistically significant difference in dimensional change or surface roughness was observed for any radiation regimen (P > 0.05).

  6. Ionizing radiation in the disinfection of water contaminated with potentially pathogenic mycobacteria

    International Nuclear Information System (INIS)

    Kubin, M.; Sedlackova, J.; Vacek, K.

    1982-01-01

    Sterile drinking water samples were artificially colonized with M. kansasii, M. gardonae and M. fortuitum suspensions (the numbers of viable units in 1 ml were 1.2x10 3 , 48.5 and 3.2x10 3 , respectively) prepared from mycobacterial strains replicated in Tween 80-free liquid Dubos medium STO. The contaminated water samples were irradiated from a rotary cobalt 60 source (gamma radiation, E=1.17 and 1.33 MeV, dose rate 1 kJ/kg.h at room temperature) with doses 0.7, 1.5, 2.2, 3, 9, 16 and 27 kJ/kg. The disinfecting effectiveness was assessed by direct cultivation tests (0.5 ml volumes of water inoculated on egg medium) and by cultivation on membrane filtres after filtering the whole amount of the water examined (about 500 ml). Total disinfection was recorded for M. kansasii and M. fortuitum irradiated with 9 kJ/kg and for M. gordonae after irradiation with 1.5 kJ/kg. The calculated value of D 10 =0.4 kJ/kg (i.e., the radiation dose that reduces the number of viable mycobacteria by an order of magnitude) is suggestive of a strong disinfecting effect of ionizing radiation on the tested strains of potentially pathogenic mycobacteria. The results indicate that ionizing radiation could be applxcable in disinfecting supply and potable water contaminated with mycobacteria difficult to remove by other methods which, as a rule, cannot ensure permanent disinfection. (author)

  7. Ionizing radiation in the disinfection of water contaminated with potentially pathogenic mycobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Kubin, M [Institut Hygieny a Epidemiologie, Prague (Czechoslovakia); Sedlackova, J; Vacek, K [Ustav Jaderneho Vyzkumu CSKAE, Rez (Czechoslovakia)

    1982-01-01

    Sterile drinking water samples were artificially colonized with M. kansasii, M. gardonae and M. fortuitum suspensions (the numbers of viable units in 1 ml were 1.2x10/sup 3/, 48.5 and 3.2x10/sup 3/, respectively) prepared from mycobacterial strains replicated in Tween 80-free liquid Dubos medium STO. The contaminated water samples were irradiated from a rotary cobalt 60 source (gamma radiation, E=1.17 and 1.33 MeV, dose rate 1 kJ/kg.h at room temperature) with doses 0.7, 1.5, 2.2, 3, 9, 16 and 27 kJ/kg. The disinfecting effectiveness was assessed by direct cultivation tests (0.5 ml volumes of water inoculated on egg medium) and by cultivation on membrane filtres after filtering the whole amount of the water examined (about 500 ml). Total disinfection was recorded for M. kansasii and M. fortuitum irradiated with 9 kJ/kg and for M. gordonae after irradiation with 1.5 kJ/kg. The calculated value of D/sub 10/=0.4 kJ/kg (i.e., the radiation dose that reduces the number of viable mycobacteria by an order of magnitude) is suggestive of a strong disinfecting effect of ionizing radiation on the tested strains of potentially pathogenic mycobacteria. The results indicate that ionizing radiation could be applicable in disinfecting supply and potable water contaminated with mycobacteria difficult to remove by other methods which, as a rule, cannot ensure permanent disinfection.

  8. The use of shore wave ultraviolet radiation for disinfection in operating rooms

    International Nuclear Information System (INIS)

    Baanrud, H.; Moan, J.

    1999-01-01

    Over a number of years short wave ultraviolet radiation (UVC;200-280 nm) has been used to disinfect air and surfaces in operating rooms, patient rooms and laboratories, as well as air in ventilation ducts. Despite the well-documented effect of ultraviolet radiation on air quality, this technology has been relatively little used. One advantage of this method is that the UVC sources ensure a continuous reduction in the number of airborne microorganisms that are generated all the time. There are, however, some disadvantages with this method. Human exposure to ultraviolet C may cause keratoconjunctivitis and erythema and requires protection of the skin and the eyes of people exposed to levels above recommended exposure limits. However, by enclosing the UVC sources or by irradiation in the absence of human activity, human exposure is eliminated. These and other aspects concerning the use of short wave ultraviolet radiation as a disinfection agent in operating rooms are discussed in this article

  9. Radiation induced chemical changes in and disinfection of organic wastes suitable for supplemental feed

    International Nuclear Information System (INIS)

    Groneman, A.F.

    1980-01-01

    Ionizing radiation has been found to disinfect organic wastes and simultaneously ease the separation of suspended solids from water. Because these effects can have important favourable impacts on the technology of upgrading organic wastes to animal feed or fertilizers, experimental studies are reported on the rationale of effects of gamma irradiation or disinfection and separation of the solid and the liquid phase of organic waste systems. The radiation inactivation of microorganisms occurs by direct and indirect action. Mechanisms of inactivation are discussed and measures are proposed how the indirect action of the radiation inactivation of microorganisms can be increased. Effects of gamma irradiation on dewatering properties of organic wastes were indirectly caused by the oxidizing OH radicals produced by the irradiation of water. OH radicals react with organic components of the solid phase which leads to their solubilisation resulting in an increase of the total organic carbon concentration in the liquid phase. Results of a mutagenicity test indicate that the solvated compounds exhibited no mutagenic activity. Microbiological case studies on the disinfection and upgrading of liquid and solid organic wastes to animal feed are discussed and the acceptance of radiation processing is evaluated. (Auth.)

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

    Science.gov (United States)

    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.

  11. Inhibition of trihalomethane formation in city water by radiation-ozone treatment and rapid composting of radiation disinfected sewage sludge

    International Nuclear Information System (INIS)

    Takehisa, M.; Arai, H.; Arai, M.

    1985-01-01

    Humic acid and Fulvic acid in natural water are precursors of carcinogenic THM which is formed during chlorine disinfection in city water processing. The radiation-oxidation process in the presence of ozone is effective to remove the precursors. The THM formation was reduced more than the decrease in TOC by the combination treatment. This is mainly due to a change in the chemical structure of the oxidation products. A composting of radiation disinfected sludge cake for agricultural reuse could be achieved within 3 days primary fermentation in a sewage plant. The rapid fermentation with use of radiation is effective to scale down of a fermentor of composting plant and the process reduces a health risk from the workers as well as final users. (author)

  12. Inhibition of trihalomethane formation in city water by radiation-ozone treatment and rapid composting of radiation disinfected sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Takehisa, M; Arai, H; Arai, M

    1985-01-01

    Humic acid and Fulvic acid in natural water are precursors of carcinogenic THM which is formed during chlorine disinfection in city water processing. The radiation-oxidation process in the presence of ozone is effective to remove the precursors. The THM formation was reduced more than the decrease in TOC by the combination treatment. This is mainly due to a change in the chemical structure of the oxidation products. A composting of radiation disinfected sludge cake for agricultural reuse could be achieved within 3 days primary fermentation in a sewage plant. The rapid fermentation with use of radiation is effective to scale down a fermentor of a composting plant and the process reduces health risk for the workers as well as final users.

  13. UV disinfection of water. 1. Effect on microorganisms/virus conditions which can limit the use of UV radiation as a means of disinfection

    Energy Technology Data Exchange (ETDEWEB)

    Skipperud, E; Johansen,; Myhrstad, J A [Statens Inst. for Folkehelse, Oslo (Norway)

    1978-01-01

    UV radiation has been found to have advantages over chloration for the disinfection of water. New regulations for dietary conditions on Norwegian ships introduced in 1974 led to increased use of UV disinfection, and this has in the following years spread to waterworks. The present article is based on a study to determine possible limitation. The nature of the injuries to the microorganisms is first discussed, together with repair mechanisms. A table is given showing the energy required for 90 and 100 percent inactivation of a number of microorganisms. Some other factors affecting UV inactivation are briefly mentioned. (JIW).

  14. Disinfestation of Date Fruits by Gamma Radiation and Its Effect on the Nutritional Contents of Dates

    International Nuclear Information System (INIS)

    Ahmed, Z.A.; Boshra, S.A.; Mikhaiel, A.A.; Hassan, N.M.

    2008-01-01

    Irradiation dis infestations of Siwa date fruits seems to be a very promising method. Considerations of the health safety of irradiated date fruits involve nutritional contents has been investigated by chemical analysis. The dose of 400 and 1000 Gy were lethal for the different stages of oases date moth, Ephestia calidella. Dates are a good source of iron and potassium, they also contain calcium, magnesium, copper and other minerals. The radiation dose 1000 Gy had mostly affected the carbohydrates content, some minerals as Fe, Ca and Na partially changed by the treatment. Protein and vitamin contents were slightly affected

  15. Radiation-chemical disinfection of dissolved impurities and environmental protection

    International Nuclear Information System (INIS)

    Petrukhin, N.V.; Putilov, A.V.

    1986-01-01

    Radiation-chemical neutralization of dissolved toxic impurities formed in the production processes of different materials, while modern plants being in use, is considered. For the first time the processes of deep industrial waste detoxication and due to this peculiarities of practically thorough neutralization of dissolved toxic impurities are considered. Attention is paid to devices and economic factors of neutralization of dissolved toxic impurities. The role of radiation-chemical detoxication for environment protection is considered

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

    Science.gov (United States)

    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.

  17. Insect disinfestation of packed dates by gamma-radiation

    International Nuclear Information System (INIS)

    Ahmed, M.S.H.; Hameed, A.A.; Kadhum, A.A.; Ali, S.R.

    1985-01-01

    The effect of gamma-radiation on insect disinfestation of commercially packed dry dates was studied in collaboration with the Iraqui Date Administration. The wrapping of ''window carton lunch boxes'' (each holding 250 g of dry dates, Zahdi variety) with polyethylene film, compared to cellophane, prevented reinfestation for a long period of storage if treated with 0.70 kGy of gamma-radiation. All live insects that were found in the irradiated boxes and tested were genetically sterile, and those in different developmental stages died within a short period of time without passing through metamorphosis. In all cases (treated or control batches), cellophane-sealed boxes proved to be more vulnerable to reinfestation. Dates packed in plastic cups, used for N/sub 2/ vacuum packaging, were also effectively disinfested by the same dose of radiation. The value of airtight packaging will certainly add to the advantage of the high penetration power of gamma-radiation relative to methyl bromide fumigation. Results of the assessment of the damaging ability of irradiated insects indicate that treatment of packed dates with 0.70 kGy is sufficient as far as quarantine measures are concerned where the possible increase in infestation rate, brought about by radio-resistant insect stages that usually constitute a small fraction in nature, is negligible

  18. Development of a process for radiation disinfection and composting of sewage sludge

    International Nuclear Information System (INIS)

    Kawakami, Waichiro; Hashimoto, Shoji; Nishimura, Koichi; Watanabe, Hiromasa; Watanabe, Hiroshi

    1985-05-01

    Radiation disinfection of sewage sludge and composting of the irradiated sludge were studied for a purpose of their safe land application from a viewpoint of environment protection and beneficial utilization of resources. Seasonal changes of total bacterial number and coliform number in sludge cake, those of the dose required for disinfection and the regrowth of bacteria after disinfection were examined. Determination of residual bacteria werealso carried out. The dose for disinfection of coliform was 0.3-0.5 Mrad(3-5 kGy). Fermentation conditions such as temperature, pH, pressure, buking agent and seeds, were studied in addition to continuation and scale-up of the process for aerobic fermentation of irradiated sludge for a purpose of shortening the period for primary fermentation. And conditions for maintaining high oxygen permeability of sludge and deordorization were also investigated. The optimum conditions for composting were shown to be near 7 for pH, 50 0 C for temperature. Composting in a continuous process was studied based on microbiological rate expressions, and it was shown that the composting rate could be estimated from batch-experimental data. Composting in a large scale was investigated by using a small scale fermentor and a computer, and was estimated to have the same rate as in a small scale, when the fermentation conditions were maintained at the optimum. It was also shown that the diameter of sludge grain should be less than about 5 mm to obtain high oxygen permeability of sludge and maintain the fast rate in isothermal composting, and that the evolution of anmonia which is an index of ill-smell would also cease within 3 days under the optimum conditions. The products obtained in the isothermal composting of irradiated sludge were shown to be almost the same as those by usual composting processes using nonirradiated sludges. (J.P.N.)

  19. Utilization of Gamma Radiation for Disinfecting Domestic Wastewater

    International Nuclear Information System (INIS)

    Aldehmani, K.; Abokhabta, S.; Rahil, E.; Elammari, M.; Aboudeeb, F.

    2004-01-01

    Wastewater treatment by Gamma radiation is an effective, economic and environmentally friendly as the water produced has the specification to be reused for watering trees, gardens, football fields and golf courses instead of using fresh water that can be saved for drinking purposes as we suffer a severe shortage of fresh water. Sewage water samples were brought from Elhadba Elkhadra wastewater treatment plant which is located in the City of Tripoli. Samples were taken from two places: the inlet of the plant and from the stream coming out from the biological treatment, they are taken in sterile plastic bottles to ensure that cross contamination does not take place. Samples were irradiated at Tajura Research Centre with different doses ranged between 0.5 and 2 kGy with a dose rate of 10 Gy/min. These samples were investigated chemically and microbiologically. A study was carried out on the effect of gamma radiation on pathogenic organisms, and the total suspended solids in the raw and treated samples. Results showed that the doses 2.0 kGy and 1.5 kGy were enough to terminate the total microbial count and Enterobacter ease respectively but only a dose of 1.0 kGy was needed to eliminate total coliform, fecal coliform and spore forming bacteria. There were also higher BOD, pH and E.C. values in raw sewage than the sewage that was subjected to biological treatment which gave a good indication for the efficiency of the biological treatment. (authors)

  20. Disinfection of municipal water using solar radiation: an economical approach for rural dwellers in the coastal region of Karachi

    International Nuclear Information System (INIS)

    Ahmed, M.F.; Saleem, M.

    2010-01-01

    At present acquiring safe drinking water in rural or remote areas of Pakistan is a challenging task for dwellers. Coast line of Karachi is a sporadic habitat of villages not having access to safe drinking water. Many incidents of waterborne diseases have been reported in that area and attributed to contaminated municipal water supply. Solution of the problem is disinfection however, general methods of water disinfection such as boiling, UV-lamp, ozonation and chemical additive are costly or require skilled manpower. Present study investigates the solar disinfection method to treat municipal water supply at Karachi Institute of Power Engineering (KINPOE) located at the coastal belt of Karachi. Effect of exposure time, bottle material and turbidity of water on the process performance was evaluated. Model indicator bacteria total coliform (TC) was used to evaluate the solar disinfection process. Study revealed that in order to disinfect the municipal water, samples should be filled in PET transparent bottles, having turbidity below 23 NTU, and expose to solar radiation in the study area at least for one hour. Study shows that solar disinfection may provide safe drinking water meeting national and international water quality standards at minimum cost and effort in sunshine rich areas and not having access to other water purification systems. (author)

  1. Disinfection of wastewater from a Riyadh Wastewater Treatment Plant with ionizing radiation

    International Nuclear Information System (INIS)

    Basfar, A.A.; Abdel Rehim, F.

    2002-01-01

    The goal of this research was to establish the applicability of the electron beam treatment process for treating wastewater intended for reuse. The objective of this study was to determine the effectiveness of gamma irradiation in the disinfection of wastewater, and the improvement of the water quality by determining the changes in organic matter as indicated by the measurement of biochemical oxygen demand (BOD), chemical oxygen demand (COD) and total organic carbon (TOC). Samples of effluent, before and after chlorination, and sludge were obtained from a Riyadh Wastewater Treatment Plant. The studies were conducted using a laboratory scale 60 Co gamma source. The improvement in quality of the irradiated samples was demonstrated by the reduction in bacteria, and the reduction in the BOD, COD and TOC. Radiation of the wastewater provided adequate disinfection while at the same time increasing the water quality. This treatment could lead to additional opportunities for the reuse of this valuable resource. Limited studies, conducted on the anaerobically digested secondary biosolids, showed an improvement in bacterial content and no change in COD

  2. Effect of radiation on disinfection and mechanical properties of Korean traditional paper, Hanji

    International Nuclear Information System (INIS)

    Choi, Jong-il; Chung, Yong Jae; Kang, Dai Ill; Lee, Kyu Shik; Lee, Ju-Woon

    2012-01-01

    Fumigants, including methyl bromide and ethylene oxide, are generally used for the preservation of the Korean cultural heritage, especially paper products like letters and books. However, the use of fumigants is banned because of their harmful effects on humans and the environment. Gamma irradiation is being considered as an alternative for the sterilization of insects and fungi in organic products. Therefore, the purpose of this study was to investigate the sterilization effects of radiation and its effect on the mechanical properties of the Korean traditional paper—Hanji. Treatment doses of 9 kGy and 8 kGy of gamma irradiation inactivated 5 log units of Aspergillus niger and Bacillus cereus spores inoculated on Hanji, respectively. The gamma irradiations up to an absorbed dose of 50 kGy resulted in no significant changes in the tensile strength, bursting strength, and appearance of Hanji. These results confirmed that radiation treatment disinfects the Korean traditional paper efficiently without changing its properties and that this treatment could be used to prevent the damage of Korean ancient archives by molds and fungi. - Highlights: ► Radiation sensitivity of mold was tested on Korean traditional paper, Hanji. ► Mechanical properties of Hanji were measured to investigate the effect of irradiation. ► This result is useful to conserve the Korean cultural heritages made by Hanji with the radiation technology.

  3. Antibacterial activity of some disinfectants, essential oils and radiation against some bacterial isolates

    International Nuclear Information System (INIS)

    Ramadan, A.B.; Abo-State, M.A.M.; Ghaly, M.F.; Ezzat, S.M.; Hefni, H.M.I.

    2006-01-01

    Nosocomial bacteria has been considered problems for all hospitals. Bacterial isolates of the present study were isolated from Sharkia Hospitals, Egypt. The isolates were S. aureus, P. aeruginosa, E. coli, Klebsiella spp., Citrobacter spp., Enterobacter spp., Proteus spp., Serratia spp. and S. epidermidis. Two disinfectants (savlon and phenolics) were examined against all the bacterial isolates at the hospitals recommended concentrations to determine the most resistance bacterial isolates. Twelve essential oils, ultraviolet radiation, Gamma radiation and laser were tested against the most resistant bacterial isolates to disinfectants and antiseptics. These bacterial isolates were S. aureus and P. aeruginosa. The most effective concentration of savlon was 2%, while that of phenolics were 4 and 5% . Fumigation of essential oils of Eugenia caryophyllata L., Marjorum hortensis L., Foeniculum vulgare L., Rosmarinus officinalis L. and Thymus vulgaris L. had high effects against these bacterial isolates. Rosmarinus officinalis L., Marjorum hortensis L., Eugenia caryophyllata L. and Thymus vulgaris L. essential oils had high effects on bacterial isolates by disc diffusion method. Matricaria chamomilla L. and Eucalyptus spp. oils had no effects against P. aeruginosa. Both essential oils of Jasminum gradiflocum L. and Jasminum sambac L. had no effects by fumigation and diffused essential oils. Ultraviolet irradiation had lethal effect on S. aureus when it exposed to ultraviolet for 10 minutes at a distance of 20 cm, while it had a lethal effect on P. aeruginosa when exposed to the rays for 7 minutes at the same distance. Gamma irradiation had lethal effect on P. aeruginosa and S. aureus at 2.5 and 3 KGy, respectively. Laser had a lethal effect on P. aeruginosa and S. aureus after 14 and 15 minutes of exposure, respectively

  4. Morphological response of human rotavirus to ultra-violet radiation, heat and disinfectants

    International Nuclear Information System (INIS)

    Rodgers, F.G.; Hufton, P.; Kurzawska, E.; Molloy, C.; Morgan, S.

    1985-01-01

    The morphological damage induced in human rotavirus particles by exposure to UV radiation (254 nm) increased progressively with length of treatment. Exposure of the virus in suspension to 9000 ergs/cm 2 /s removed the smooth capsid layer from 50% of particles after 1 min and from all the virions within 10 min. By this time, the number of stain-penetrated or empty particles increased markedly, along with the appearance of virus-derived debris in the form of disrupted and isolated capsomeres. After treatment for 120 min no intact virus particles were observed. The action of wet (100 0 C) or dry (60 0 C) heat resulted in changes similar to those effected by UV radiation. Sodium hypochlorite, cetrimide and 70% ethanol induced a rapid loss of the outer capsid layer, but, compared with UV radiation or heat, a slower increase in the number of stain-penetrated particles was noted. Chlorhexidine and phenol had effects on virus structure only after extended periods of exposure, whilst glutaraldehyde treatment had little influence on virus morphology. Glutaraldehyde 2% v/v would appear to be most suitable for the disinfection of rotavirus-containing electron microscope grids before their examination. (author)

  5. Water disinfection with solar radiation; Desinfeccion del agua con radiacion solar

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Alejandra; Cortes, Juana E; Rodriguez, Miriam; Mundo, Alfredo; Vazquez, Sandra [Instituto Mexicano de Tecnologia del Agua, Jiutepec, Morelos (Mexico); Estrada, Claudio A [Centro de Investigacion en Energia, Temixco, Morelos (Mexico)

    2000-07-01

    Water disinfection by exposure to solar radiation is a low cost and easy application option to rural communities. The treatment of water can be done using plastic bags or plastic bottles of two litters setting on a reflective material. The efficient of the plastic bottles is lower than the one plastic bags, but the plastic bottles have a much better control of the treated water avoiding its recontamination. In order to increase the efficiency of disinfection using plastic bottles, two solar concentrators, using flat mirrors, were designed and built. Effluent water from a treatment plant of residual waters was used for the testing. Several comparison were carried out taking into account the position of the concentrators, the transparency of the bottles and the bags. The results show that using the concentrator that adjust its position to the sun every hour, a 100% disinfection is obtained in 4 hours of direct exposure to the sun rays in a sunny day. The period of time can be reduced up to 2 hours, if instead using transparent bottles, the bottles are black painted at their bottom half. With these results, the basis to design a cheap concentrator of easy construction to be used in rural communities have been settle. [Spanish] La desinfeccion del agua por exposicion a la luz solar fotodesinfeccion es una opcion de bajo costo y facil aplicacion para las comunidades rurales. El tratamiento puede llevarse a cabo utilizando bolsas o botellas de plastico transparente de dos litros de capacidad colocadas sobre un material reflejante. Las botellas son menos eficientes que las bolsas, pero permiten un mejor control del agua tratada evitando su recontaminacion. Para aumentar la eficiencia de la desinfeccion utilizando las botellas, se disenaron y construyeron dos concentradores solares de espejos planos que permitieron disminuir el tiempo de exposicion requerido cuando se utilizan estas. Para las pruebas de desinfeccion se utilizo agua del efluente de una planta de tratamiento

  6. Effect of radiation on disinfection and mechanical properties of Korean traditional paper, Hanji

    Science.gov (United States)

    Choi, Jong-il; Chung, Yong Jae; Kang, Dai Ill; Lee, Kyu Shik; Lee, Ju-Woon

    2012-08-01

    Fumigants, including methyl bromide and ethylene oxide, are generally used for the preservation of the Korean cultural heritage, especially paper products like letters and books. However, the use of fumigants is banned because of their harmful effects on humans and the environment. Gamma irradiation is being considered as an alternative for the sterilization of insects and fungi in organic products. Therefore, the purpose of this study was to investigate the sterilization effects of radiation and its effect on the mechanical properties of the Korean traditional paper—Hanji. Treatment doses of 9 kGy and 8 kGy of gamma irradiation inactivated 5 log units of Aspergillus niger and Bacillus cereus spores inoculated on Hanji, respectively. The gamma irradiations up to an absorbed dose of 50 kGy resulted in no significant changes in the tensile strength, bursting strength, and appearance of Hanji. These results confirmed that radiation treatment disinfects the Korean traditional paper efficiently without changing its properties and that this treatment could be used to prevent the damage of Korean ancient archives by molds and fungi.

  7. Disinfection of secondary effluent by gamma radiation inactivation efficiency and regrowth

    International Nuclear Information System (INIS)

    Sekiguchi, M.; Sawai, T.; Shimokawa, T.; Sawai, T.

    1992-01-01

    Inactivation efficiencies of several microorganisms in secondary effluents (SE) from sewage treatment plants by gamma radiation were investigated. Escherichia coli, Klebsiella pneumoniae and Enterobacter cloacae inoculated in SE were very sensitive but Streptcoccus sp. was resistant to gamma radiation. In addition, no significant difference was found between the combined sewer system and the separate sewer system in regards to the inactivation efficiencies of the bacteria inoculated in the SE. The number of total bacteria in SE was rapidly decreased in the dose range of 0 to 0.2-0.3 kGy but the number gradually fell over the dose range. Moreover, the number of total coliforms almost exponentially decreased with increasing dose, and fell to undetectable levels at about 0.5 kGy. Because of the decrease of the initial bacteria number in SE, adequate filtrating treatments were effective in lowering the irradiation dose for disinfection. Further, the effects of filtrating treatment on bacteria regrowth in SE are discussed. (author)

  8. Water and Wastewater Disinfection with Peracetic Acid and UV Radiation and Using Advanced Oxidative Process PAA/UV

    Directory of Open Access Journals (Sweden)

    Jeanette Beber de Souza

    2015-01-01

    Full Text Available The individual methods of disinfection peracetic acid (PAA and UV radiation and combined process PAA/UV in water (synthetic and sanitary wastewater were employed to verify the individual and combined action of these advanced oxidative processes on the effectiveness of inactivation of microorganisms indicators of fecal contamination E. coli, total coliforms (in the case of sanitary wastewater, and coliphages (such as virus indicators. Under the experimental conditions investigated, doses of 2, 3, and 4 mg/L of PAA and contact time of 10 minutes and 60 and 90 s exposure to UV radiation, the results indicated that the combined method PAA/UV provided superior efficacy when compared to individual methods of disinfection.

  9. Water and Wastewater Disinfection with Peracetic Acid and UV Radiation and Using Advanced Oxidative Process PAA/UV

    OpenAIRE

    Beber de Souza, Jeanette; Queiroz Valdez, Fernanda; Jeranoski, Rhuan Felipe; Vidal, Carlos Magno de Sousa; Cavallini, Grasiele Soares

    2015-01-01

    The individual methods of disinfection peracetic acid (PAA) and UV radiation and combined process PAA/UV in water (synthetic) and sanitary wastewater were employed to verify the individual and combined action of these advanced oxidative processes on the effectiveness of inactivation of microorganisms indicators of fecal contamination E. coli, total coliforms (in the case of sanitary wastewater), and coliphages (such as virus indicators). Under the experimental conditions investigated, doses o...

  10. Seasonal changes in bacterial counts and radiation-disinfection of sewage sludge

    International Nuclear Information System (INIS)

    Watanabe, Hiroshi; Ito, Hitoshi; Takehisa, Masaaki; Iizuka, Hiroshi.

    1981-01-01

    The effect of radiation on sewage sludge was investigated to disinfect it. The results obtained were as follows: 1. In either activated sludge or digested sludge dewatered by centrifugation, total bacteria and coliforms were up to 3.0 x 10 9 /g and 3.5 x 10 8 /g, respectively. In the activated sludge which was dewatered by a filter-press with calcium oxide and iron chloride, total bacteria were up to 3.0 x 10 5 /g, while coliforms were hardly detected. 2. The fraction of coliforms was somewhat more in centrifuged sludge than in raw sludge. 3. The radiosensitivity of coliforms in raw sludge differed between samples. Namely, some sludge was sterilized with 0.5 Mrad while others were not sterilized even with 1.0 Mrad. On the other hand, coliforms in dewatered sludge were sterilized with 0.5 Mrad without seasonal change, but total bacteria were more radioresistant and more than 13 Mrad was required to reduce it to an undetectable level. From these results it is concluded that the dewatered sludge should be irradiated at 0.5 Mrad to eliminate the coliforms in it. (author)

  11. Disinfection of sewage sludge by gamma radiation, electron beams and alternative methods

    International Nuclear Information System (INIS)

    Lessel, T.

    1997-01-01

    Sewage sludges generally contain high concentrations of pathogens, even after digestion or other conventional treatments for stabilization. Disinfection can be effected by irradiation (e.g. gamma or electron beam), by heat treatment (pasteurization or thermophilic stabilization), and by changing the pH (lime treatment). Irradiation is a simple and reliable process for disinfection with special advantages and favorable side-effects. Irradiation can be combined with oxygenation, heat or other treatments, with favorable synergistic effects. The total costs for the irradiation treatment of sewage sludges are comparable to those of alternative disinfection methods. Most of the worldwide practical experience has been obtained at the sewage-sludge irradiation plant in Geiselbullach (10 km west of Munich, Germany), which was continuously in operation from 1973 to 1993. A multidisciplinary research programme was conducted during the first 8 years. In subsequent years, the plant was operated commercially for sewage-sludge disinfection, without public funds. Other demonstration or research plants for sewage-sludge irradiation have been reported in the USA, India, Russia, Japan, Austria, Germany and Hungary. (author)

  12. Disinfection of an advanced primary effluent using peracetic acid or ultraviolet radiation for its reuse in public services.

    Science.gov (United States)

    Julio, Flores R; Hilario, Terres-Peña; Mabel, Vaca M; Raymundo, López C; Arturo, Lizardi-Ramos; Ma Neftalí, Rojas-Valencia

    2015-03-01

    The disinfection of a continuous flow of an effluent from an advanced primary treatment (coagulation-flocculation-sedimentation) with or without posterior filtration, using either peracetic acid (PAA) or ultraviolet (UV) radiation was studied. We aimed to obtain bacteriological quality to comply with the microbiological standard established in the Mexican regulations for treated wastewater reuse (NOM-003-SEMARNAT-1997), i.e., less than 240 MPN (most probable number) FC/100 mL. The concentrations of PAA were 10, 15, and 20 mg/L, with contact times of 10, and 15 min. Fecal coliforms (FC) inactivation ranged from 0.93 up to 6.4 log units, and in all cases it reached the limits set by the mentioned regulation. Water quality influenced the PAA disinfection effectiveness. An efficiency of 91% was achieved for the unfiltered effluent, as compared to 99% when wastewater was filtered. UV radiation was applied to wastewater flows of 21, 30 and 39 L/min, with dosages from 1 to 6 mJ/cm². This treatment did not achieve the bacteriological quality required for treated wastewater reuse, since the best inactivation of FC was 1.62 log units, for a flow of 21 L/min of filtered wastewater and a UV dosage of 5.6 mJ/cm².

  13. Radiation surveillance in Austria in 2000. Dates and evaluation

    International Nuclear Information System (INIS)

    Bobek, E.; Streeruwitz, E.

    2001-11-01

    This report presents results of the radiation surveillance in Austria in 2000, performed by the competent authorities, based on the Austrian Radiation Protection Act. In particular data of large scale monitoring concerning radioactive contamination and of nuclear research reactor emission and immission control are given. In Austria an extensive program is realized for the purpose of large scale surveillance on radioactivity. On the one hand an early radiation warning system with 336 gamma dose rate monitors and several partly nuclide specific air contamination monitors is operated. The data are automatically communicated to various authorities in real-time. On the other hand the radionuclide content of various media such as air, precipitation, surface water, foodstuffs etc is monitored by periodic sampling and subsequent analysis in laboratories. In addition to this routine program special projects are carried out for investigation of specific media and to improve the knowledge of the time dependence respectively of regional aspects of the contamination situation. The inspection of the nuclear installations by the authorities concerning emissions and immissions is set up of two parts: inspection of the quality of the internal control by the operator and independent surveillance by examination of samples taken by the authority. In 2000 the average annual radiation exposure of the Austrian population amounted to about 4.2 mSv effective dose per person. The contributions dominating by far originate from natural and medical sources of radiation. In comparison with these, contributions from all other sources of radiation are extremely small. The average annual effective dose caused by natural radiation amounts to approximately 2.9 mSv per person. The inhalation of the radioactive noble gas radon and its short lived progeny in the mean contributes more than half to this exposure. Mainly because of different radon concentrations considerable variations in natural

  14. Radiation measurements in Austria in 1999 - date and evaluation

    International Nuclear Information System (INIS)

    Bobek, E.; Streeruwitz, E.

    2000-12-01

    This report presents results of the radiation surveillance in Austria in 1999, performed by the General Directorate VI of the Federal Chancellery, based on the Austrian Radiation Protection Act. In particular data of large scale monitoring concerning radioactive contamination and of nuclear research reactor emission and immission control are given. In Austria an extensive program is realized for the purpose of large scale surveillance on radioactivity. On the one hand an Early Radiation Warning System with 336 gamma dose rate monitors and several partly nuclide specific air contamination monitors is operated. The data are automatically communicated to various authorities in real-time. On the other hand the radionuclide content of various media such as air, precipitation, surface water, foodstuffs etc. is monitored by periodic sampling and subsequent analysis in laboratories. In addition to this routine program special projects are carried out for investigation of specific media and to improve the knowledge of the time dependence respectively of regional aspects of the contamination situation. The inspection of the nuclear installations by the authorities concerning emissions and immissions is set up of two parts: inspection of the quality of the internal control by the operator independent surveillance by examination of samples taken by the authority. In 1999 the average annual radiation exposure of the Austrian population amounted to about 4.6 mSv effective dose per person. The contributions dominating by far originate from natural and medical sources of radiation. In comparison with these, contributions from all other sources of radiation are extremely small. The average annual effective dose caused by natural radiation amounts to approximately 3.2 mSv per person. The inhalation of the radioactive noble gas radon and its short lived progeny in the mean contributes more than half to this exposure. Mainly because of different radon values considerable variations in

  15. Isolation of Bacillus subtilis as indicator in the disinfection of residual water by means of gamma radiation; Aislamiento de Bacillus subtilis como indicador en la desinfeccion de aguas residuales mediante radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Mata J, M; Colin C, A [Facultad de Quimica, UAEM, Paseo Colon esq. Tollocan s/n, Toluca, 50000 Estado de Mexico (Mexico); Lopez V, H; Brena V, M; Carrasco A, H; Pavon R, S [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    In the attempt to get more alternatives of disinfection of residual water, the Bacillus subtilis was isolated by means of gamma radiation as a bio indicator of disinfection since it turned out to be resistant to the 5 KGy dose, comparing this one with other usual microorganisms as biondicators like E. coli and S typhimurium which turn out more sensitive to such dose. (Author)

  16. The effectiveness of UV-C radiation for facility-wide environmental disinfection to reduce health care-acquired infections.

    Science.gov (United States)

    Napolitano, Nathanael A; Mahapatra, Tanmay; Tang, Weiming

    2015-12-01

    Health care-acquired infections (HAIs) constitute an increasing threat for patients worldwide. Potential contributors of HAIs include environmental surfaces in health care settings, where ultraviolet-C radiation (UV-C) is commonly used for disinfection. This UV-C intervention-based pilot study was conducted in a hospital setting to identify any change in the incidence of HAIs before and after UV-C intervention, and to determine the effectiveness of UV-C in reducing pathogens. In a hospital in Culver City, CA, during 2012-2013, bactericidal doses of UV-C radiation (254 nm) were delivered through a UV-C-based mobile environmental decontamination unit. The UV-C dosing technology and expertise of the specifically trained personnel were provided together as a dedicated service model by a contracted company. The incidence of HAIs before and after the intervention period were determined and compared. The dedicated service model dramatically reduced HAIs (incidence difference, 1.3/1000 patient-days, a 34.2% reduction). Reductions in the total number and incidence proportions (28.8%) of HAIs were observed after increasing and maintaining the coverage of UV-C treatments. The dedicated service model was found to be effective in decreasing the incidence of HAIs, which could reduce disease morbidity and mortality in hospitalized patients. This model provides a continuously monitored and frequently UV-C-treated patient environment. This approach to UV-C disinfection was associated with a decreased incidence of HAIs. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  17. Radiation dates of holocene shorelines in Peninsula Malaysia

    International Nuclear Information System (INIS)

    Tjia, H.D.; Kigoshi, K.

    1977-01-01

    Fifteen newly determined radiocarbon dates indicate the presence of former shorelines up to 3 meters above present high tide level in the tectonically stable Peninsula of Malaysia. The sea level indicators consist of oysters in growth position (9 samples), molluscs in beach deposits (2), corals in growth position (3), and beachrock (1). In the Peninsula living oysters occur up to or slightly above high tide, modern beach deposits may occur as high as 1.5 meters above high tide, and corals live up to low tide level. The literature shows that high tide, and corals live up to low tide level. The literature shows that beachrock marks intertidal zones. Combined with seven previously published ages of raised shorelines in the region, strong evidence is presented for one or more high Holocene, eustatic sea level stands in the continental part of Southeast Asia. Periods of high sea levels occur between 2500 and 2900 yr BP, and between 4200 and 5700 yr BP. There is also some indication of high sea level between 8300 and 9500 yr BP. (author)

  18. Thermal activation and radiation quenching effects in pre-dose dating of porcelain

    International Nuclear Information System (INIS)

    Wang Weida; Xia Junding

    2005-01-01

    The pre-dose technique is very useful for thermoluminescence dating of porcelain. It incorporates two characteristics in the porcelain dating, i.e. thermal activation and radiation quenching. Two methods, activation method and quenching method, for evaluation of paleodose were introduced. The results show that activation method and quenching method one suitable for dating of lower limit age (less than 100 years B.P.) and upper limit age (greater than 1000 years B.P.), respectively. When both methods are co-used, the dating will be more accurate. (authors)

  19. Disinfection process of municipal wastewater through ultraviolet radiation: Application in the wastewater treatment plant of Jerez de la Frontera; Desinfeccion de aguas residuales urbanas mediante radiacion ultravioleta: Aplicacion enla EDAR de Jerez de la Frontera

    Energy Technology Data Exchange (ETDEWEB)

    Salcedo Davila, I.; Andrades Balao, J. A.; Quiroga Alonso, J. M.

    2002-07-01

    This paper reports the results obtained of the disinfection through ultraviolet radiation of the treated municipal wastewater in the plant of Jerez de la Frontera for possible municipal and tourist/recreational reuse. The results obtained show that 1.265 J/m''2 of UV doses cause nearly a 99, 9% decrease of the studied microorganisms (total coliform, fecal coliform and fecal strepto cocos) in more than 77% of the carried out studies. The disinfection unitary cost, at industrial scale, was 0.03 E/m''3 waste-water, which means the UV radiation treatment is very competitive against others disinfection systems. (Author) 10 refs.

  20. Disinfection and conservation of mangoes, Mangifera indica L., haden and keitt varieties by gamma radiation

    International Nuclear Information System (INIS)

    Domarco, R.E.; Walder, J.M.M.; Arthur, V.

    1988-05-01

    The radiation doses of disinfestation and conservation for mangoes of Haden and Keitt varieties are described, including experimental data with different doses and different time of irradiation. (author)

  1. Investigations on insect disinfestation of dried dates by using gamma radiation

    International Nuclear Information System (INIS)

    Ahmed, M.S.H.

    1981-01-01

    Reviews the laboratory experiments carried out in Iraq to control the most important insect pests of dates in storage, viz. the fig moth, Ephestia cautella and the saw-toothed grain beetle, oryzaephilus surinamensis by gamma-radiation. Developmental stages of Ecutella in general had a much higher resistance to gamma-radiation than the corresponding stages of O-surinamensis. Treatment with a dose of 20 Krad resulted in 100 mortality in the most damaging developmental stages of the species. (46 refs.)

  2. Effect of peracetic acid, ultraviolet radiation, nanofiltration-chlorine in the disinfection of a non conventional source of water (Tula Valley).

    Science.gov (United States)

    Trujillo, J; Barrios, J A; Jimenez, B

    2008-01-01

    Water supply for human consumption requires certain quality that reduces health risks to consumers. In this sense, the process of disinfection plays an important role in the elimination of pathogenic microorganisms. Even though chlorination is the most applied process based on its effectiveness and cost, its application is being questioned considering the formation of disinfection by-products (DBPs). Therefore, alternative disinfectants are being evaluated and some treatment processes have been proposed to remove DBPs precursors (organic matter. This paper reports the results of disinfection of a non conventional source of water (aquifer recharged unintentionally with raw wastewater) with peracetic acid (PAA) and ultraviolet radiation (UV) as well as nanofiltration (NF) followed by chlorination to produce safe drinking water. The results showed that a dose of 2 mg/L PAA was needed to eliminate total and faecal coliforms. For UV light, a dose of 12.40 mWs/cm2 reduced total and faecal coliforms below the detection limit. On the other hand, chlorine demand of water before NF was 1.1-1.3 mg/L with a trihalomethane formation potential (THMFP) of 118.62 microg/L, in contrast with chlorination after NF where the demand was 0.5 mg/L and THMFP of 17.64 microg/L. The recommended scheme is nanofiltration + chlorination.

  3. Disinfection of drain water of tomato by means of UV radiation and slow sand filtration in real greenhouse circumstances.

    Science.gov (United States)

    De Rocker, E; Goen, K; Van Poucke, K

    2006-01-01

    The efficiency of the disinfection of drain water was tested at 11 greenhouses with tomato cultivation on rockwool substrate in Flanders (Belgium) by means of mycological analysis. In addition the presence of phytopathogenic fungi in the drain water was analysed at 2 supplementary greenhouses with recirculation without disinfection.

  4. Application of gas-fired infra-red radiator to thermal disinfection of horticultural substrate

    International Nuclear Information System (INIS)

    Wawer, M.; Osiński, A.

    1998-01-01

    The studies were carried out on heating horticultural substrate (moor peat - bark, 1:1 by volume) with a gas-fired infra-red radiator to destroy the pests and pathogens. Minimum distance between radiator and substrate surface was determined considering assumed time of heating. Dynamics of substrate heating was determined depending on its layer thickness and kind of surface under substrate layer; black rubber, ground steel sheet and aluminium foil were used as the surface. Considerable decreasing of infra-red radiation penetrability through the substrate layer above 7 mm thick was found as well as an significant effect of the radiation reflected from the surface under substrate layer on the intensity of its heating. It was also stated that heating horticultural substrates with the gas-fired infra-red radiator enables to rise the temperature of thin substrate layer up to 70 degree of C within relatively short time [pl

  5. Disinfection of sewage

    International Nuclear Information System (INIS)

    Arenas, J.

    1984-01-01

    Laboratory studies at IPEN and SEDAPAL have shown the effectiveness disinfection of sewage by means of ionizing radiations. A dose of 1 Kilo Gray reduces the coliforms and salmonella under the permissible levels. This method should allow to use again the liquids in the agriculture or its disposal like sea nutrient

  6. Investigation of TL properties of sand collected from sewage sludge as an ''in situ'' dosimeter in radiation disinfection

    International Nuclear Information System (INIS)

    Benny, P.G.; Bhatt, B.C.

    1996-01-01

    Thermoluminescence (TL) properties of sand, collected from sewage sludge, were studied after extensive cleaning procedures. In the sand samples treated with either hydrogen peroxide (H 2 O 2 ) or hydrofluoric acid (HF), there was a prominent TL peak at about 220 o C after γ-irradiation and 120 o C, 20 min post-irradiation annealing treatment. The dose vs TL response curves in hydrogen-peroxide-treated and HF-treated sand samples were found to be linear up to 30 and 100 Gy, respectively, beyond which they were supra-linear. The extent of post-irradiation fading in the sand sample, which was treated with H 2 O 2 and post-irradiation annealed at 120 o C for 20 min, was observed to be 8% after 21 days, while no detectable fading was observed for the sample which was HF treated and annealed at 120 o C for 20 min after γ-irradiation. Therefore, H 2 O 2 - as well as HF-treated sludge sand samples could be considered for use as in situ TL dosimeters for radiation disinfection of sewage sludge. (Author)

  7. UV disinfection of water

    International Nuclear Information System (INIS)

    Skipperud, E.; Johansen; Myhrstad, J.A.

    1978-01-01

    UV radiation has been found to have advantages over chloration for the disinfection of water. New regulations for dietary conditions on Norwegian ships introduced in 1974 led to increased use of UV disinfection, and this has in the following years spread to waterworks. The present article is based on a study to determine possible limitation. The nature of the injuries to the microorganisms is first discussed, together with repair mechanisms. A table is given showing the energy required for 90 and 100 percent inactivation of a number of microorganisms. Some other factors affecting UV inactivation are briefly mentioned. (JIW)

  8. Disinfection of Airborne Organisms by Ultraviolet-C Radiation and Sunlight

    Science.gov (United States)

    2012-07-01

    organisms used in this test were E. coli cells, B. subtilis spores, Candida famata var. flareri cells, and Penicillium citrinum spores. A few studies...in Protecting Bacillus sp . Endospores Against Environmental UV Radiation. FEMS Microbiol. Ecol. 2005, 51, 231–236. Munakata, N. Comparative

  9. Solar Radiation Disinfection of Drinking Water at Temperate Latitudes: Inactivation rates for an optimized reactor configuration

    Science.gov (United States)

    Solar radiation-driven inactivation of bacteria, virus and protozoan pathogen models was quantified in simulated drinking water at a temperate latitude (34°S). The water was seeded with Enterococcus faecalis, Clostridium sporogenes spores, and P22 bacteriophage, each at ca 1 x 10...

  10. Ultraviolet disinfection of potable water

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, R. L. [Metropolitan Water District of Southern California, Los Angeles, CA (United States)

    1990-06-15

    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.

  11. Ultraviolet disinfection of potable water

    International Nuclear Information System (INIS)

    Wolfe, R.L.

    1990-01-01

    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

  12. Disinfection of the bee hive's American Foulbrood by gamma radiation from Cobalt-60

    International Nuclear Information System (INIS)

    Gosselin, P.; Charbonneau, R.

    1990-01-01

    Gamma radiation from Cobalt-60 was used to sterilize honeybee combs contaminated by Bacillus larvae. The determination of the radiosensitivity (D 10 ) was done on cultured cells in Brain Heart Infusion broth and was found to be determined at 125 Gy. The D 10 of isolated spores from contaminated combs was then determined at 0,518 kGy and the D 10 of spores irradiated in their own original environment was found at 2,05 kGy. These treated combs were then sent back in the beehives. The bees cleaned the combs thoroughly and started the storage of honey in some cells. Eggs were also layed in others. Forty five days later, there were still no sing of re-appearance of the American Foulbrood disease. (author)

  13. Quality assessment of Egyptian drinking water supplies and disinfecting using ultraviolet radiation

    International Nuclear Information System (INIS)

    Karem, H.A.; Hassan, A.A.

    2000-01-01

    Drinking water, surface and underground water were microbiological and chemical analyzed during storage in covered and uncovered tanks for four months. Microbiological analyses were carried out to determine the microbial indicators namely, Total bacterial counts, total coliform, E. coli, Enterococcus faecalis, Pseudomonas aeruginosa and Clostridium perfringens. Drinking water of Amiria municipal water station was microbiologically safe after storage in covered tanks however, in uncovered tanks the total bacterial counts increased gradually to reach 8 x 10 2 cfu/ml at the fourth month. With respect to underground water, all tested groups of microorganisms were attained high values except E. coli and E. faecalis counts were not detected. During storage the densities of total bacterial counts, total coliform and P. aeruginosa increased in both covered and uncovered tanks to reach at the fourth month 10 6 -10 7 , 58-68, 51-65 cfu/ml respectively. As to bottled water, samples of four companies producing it in Egypt were taken for analysis during the steps of production. Companies A, B and C were used underground water and company D used surface water. Results revealed that all companies were microbiologically unsatisfactory where final product still contained total bacterial counts, P. aeruginosa and C. perfringens exceeding the drinking water quality guideline values. An experiment was conducted to study the efficiency of uv radiation in reducing the densities of certain bacterial isolates inoculated in sterilized tap water. P. aeruginosa was the most sensitive bacteria followed by E. coli whereas E. faecalis and B. cereus were more resistant toward uv radiation. (author)

  14. Isolation of a bacteria of the Bacillus genus as indicator in the disinfection of residual waters by means of the ionizing radiation (e- , γ)

    International Nuclear Information System (INIS)

    Mata J, M.

    2003-01-01

    The pollutants of the water can be chemical, physical and biological. Among those biological we find to the microorganisms: bacterias, virus and protozoa. These cause important infections in many countries, mainly of Latin America. With the advance of the technology and the quick demographic growth, the biological pollution of the water has already become an important topic since it would damage the public health and it causes that their disinfection has greater attention. In the treatment of residual waters three basic treatments exist the one primary, secondary and tertiary; in this last we find the disinfection, which can be taken to end by chemical and physical methods. For this work of investigation it was used the ionizing radiation, because it is an innovative technology that it eliminates microorganisms in residual waters. The investigation consisted on treating, samples of residual water after the biological treatment of the plant RECICLAGUA with ionizing radiation (electrons and gammas), for the case of electrons it was used the dose of 0.5 kGy and for gamma the dose, of 5 kGy, later the survivor bacteria was isolated to these doses in both cases and they were carried out the tests of identification. In accordance with the obtained results can say that it is about a B. subtilis. The isolated B.subtilis was presented as a pollutant of the flora of the residual water, having a greater survival to the dose of 0.5 and 5 kGy with electrons and gammas, respectively that other present polluting microorganisms in the samples of residual water. For it fits signalize that this microorganism shows characteristics as it easy isolation and identification, the presence with pathogen microorganisms and a greater survival when being irradiated, therefore it can use as indicator in the disinfection of residual waters through ionizing radiation (electrons and gammas). (Author)

  15. Effect of gamma radiation on some embryonic stages of two stored-date insect species

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, M S.H.; Ouda, N A; Lamooza, S B; Al-Hassany, I A [Iraq Atomic Energy Commission, Baghdad. Nuclear Research Inst.

    1974-01-01

    The saw-toothed grain beetle, Oryzaephilus surinamensis (L.), and the fig moth, Ephestia (Cadra) cautella /Walker/ are good representatives of the insects that infest dates and other foodstuffs causing annually a considerable damage. These two insects differ from each other in many aspects and essentially in that the beetle possesses monocentric chromosomes while the moth has chromosomes with diffuse centromeres. Therefore the mechanism of their response to radiation is expected to be quite different at certain developmental stages where mitotic and/or meiotic divisions are involved. Different age-groups, at 12-h intervals, of eggs of both species, irradiated with 10 krad of gamma radiation from /sup 60/Co showed a differential radiosensitivity which decreased as the egg age increased. The hatchability of irradiated eggs of the two species significantly increased in a direct relation to the age in hours. However, Ephestia eggs showed a higher radioresistance in the present test than Oryzaephilus eggs. This resistance to gamma radiation might be due to the peculiar mechanism of irradiated chromosomes with diffuse centromeres during mitosis. It is concluded that in order to find the proper recommended dose for disinfestation and sterilization purposes, refined studies on the response of embryonic and other developmental stages of different insect species to radiation should be thoroughly carried out.

  16. The effects of radiation damage accumulation and annealing on fission-track dating of titanite

    International Nuclear Information System (INIS)

    Enkelmann, Eva; Jonckheere, Raymond; Ratschbacher, Lothar

    2005-01-01

    Fission-track dating of titanite is hindered by the fact that track etching is anisotropic in fresh titanites and becomes isotropic with increasing radiation damage. Independent age determinations with the population method are problematic due to different track counting efficiencies (Q) for ρ s in unannealed and ρ i in annealed titanite. Independent age determinations with the external detector method depend on correction factors for the track registration geometries (G = 0.5), counting efficiencies (Q) and range deficit (R = 1.38); however, Q is unaffected by annealing. It was attempted to determine GQR through calculation, direct experiment and on the basis of age standards. The direct experiment involves measurements of the ratio of the induced-track densities in titanite and a co-irradiated external detector. The track densities in the internal titanite surfaces could not be measured but the results for the external surfaces confirm that this approach leads to a significant overestimation of GQR, due to prior annealing. The GQR-values determined on the basis of age standards are consistent with that obtained by calculation assuming that Q ∼ 1, although there is no experimental confirmation for this fact apart from their isotropic etching characteristics. The fact that identical GQR-factors were obtained on standards of different age and uranium content suggests that a single GQR-value is appropriate for dating titanites within a broad range of radiation damage. In terms of the ζ-calibration this implies that a single ζ-factor is also suitable for dating different titanites. These findings suggest that other factors besides the accumulation of alpha-recoil damage, such as a phase transition, could be co-responsible for the different etching characteristics of annealed and unannealed titanites

  17. Sewage sludges disinfection

    International Nuclear Information System (INIS)

    Alexandre, D.

    1977-01-01

    There is an hygienic risk in using biological sewage sludges for agriculture. Systematic analysis carried out on sludges samples obtained from purification plants in East and South part of France, show the almost uniform presence of pathogenic microorganisms. Some of it survive more than 9 months after soil application. Conventional process for disinfection: liming and heat are not suitable for agricultural use. On the other hand, irradiation involves no modification in structure and composition of sludges. Radiation doses required for disinfection vary according to microorganisms. If some of them are eliminated with rather light doses (200 krad) mycobacteria, viruses and eggs of worms resist to more important doses. Security dose is estimated around 1000 krad

  18. Sewage sludges disinfection

    International Nuclear Information System (INIS)

    Alexandre, D.; Gevaudan, P.P.

    1977-01-01

    There is a hygienic risk in using biological sewage sludges for agriculture. Systematic analyses carried out on sludge samples obtained from purification plants in the Eastern and Southern part of France, show the almost uniform presence of pathogenic microorganisms. Some of them survive more than nine months after application to the soil. Conventional processes for disinfection, liming and heat, make the sludge unsuitable for agricultural use. On the other hand, irradiation involves no modification of structure and composition of sludges. Radiation doses required for disinfection vary according to the type of microorganism. Some of them are eliminated at rather low doses (200 krad), but mycobacteria, viruses and eggs of worms resist to more important doses. The security dose is estimated to be approx. 1000 krad

  19. An environmental disinfection odyssey: evaluation of sequential interventions to improve disinfection of Clostridium difficile isolation rooms.

    Science.gov (United States)

    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 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.

  20. Use of UV-C radiation to disinfect non-critical patient care items: a laboratory assessment of the Nanoclave Cabinet

    Directory of Open Access Journals (Sweden)

    Moore Ginny

    2012-08-01

    Full Text Available Abstract Background The near-patient environment is often heavily contaminated, yet the decontamination of near-patient surfaces and equipment is often poor. The Nanoclave Cabinet produces large amounts of ultraviolet-C (UV-C radiation (53 W/m2 and is designed to rapidly disinfect individual items of clinical equipment. Controlled laboratory studies were conducted to assess its ability to eradicate a range of potential pathogens including Clostridium difficile spores and Adenovirus from different types of surface. Methods Each test surface was inoculated with known levels of vegetative bacteria (106 cfu/cm2, C. difficile spores (102-106 cfu/cm2 or Adenovirus (109 viral genomes, placed in the Nanoclave Cabinet and exposed for up to 6 minutes to the UV-C light source. Survival of bacterial contaminants was determined via conventional cultivation techniques. Degradation of viral DNA was determined via PCR. Results were compared to the number of colonies or level of DNA recovered from non-exposed control surfaces. Experiments were repeated to incorporate organic soils and to compare the efficacy of the Nanoclave Cabinet to that of antimicrobial wipes. Results After exposing 8 common non-critical patient care items to two 30-second UV-C irradiation cycles, bacterial numbers on 40 of 51 target sites were consistently reduced to below detectable levels (≥ 4.7 log10 reduction. Bacterial load was reduced but still persisted on other sites. Objects that proved difficult to disinfect using the Nanoclave Cabinet (e.g. blood pressure cuff were also difficult to disinfect using antimicrobial wipes. The efficacy of the Nanoclave Cabinet was not affected by the presence of organic soils. Clostridium difficile spores were more resistant to UV-C irradiation than vegetative bacteria. However, two 60-second irradiation cycles were sufficient to reduce the number of surface-associated spores from 103 cfu/cm2 to below detectable levels. A 3 log10 reduction in

  1. A Total-Evidence Approach to Dating with Fossils, Applied to the Early Radiation of the Hymenoptera

    Science.gov (United States)

    Ronquist, Fredrik; Klopfstein, Seraina; Vilhelmsen, Lars; Schulmeister, Susanne; Murray, Debra L.; Rasnitsyn, Alexandr P.

    2012-01-01

    Abstract Phylogenies are usually dated by calibrating interior nodes against the fossil record. This relies on indirect methods that, in the worst case, misrepresent the fossil information. Here, we contrast such node dating with an approach that includes fossils along with the extant taxa in a Bayesian total-evidence analysis. As a test case, we focus on the early radiation of the Hymenoptera, mostly documented by poorly preserved impression fossils that are difficult to place phylogenetically. Specifically, we compare node dating using nine calibration points derived from the fossil record with total-evidence dating based on 343 morphological characters scored for 45 fossil (4--20 complete) and 68 extant taxa. In both cases we use molecular data from seven markers (∼5 kb) for the extant taxa. Because it is difficult to model speciation, extinction, sampling, and fossil preservation realistically, we develop a simple uniform prior for clock trees with fossils, and we use relaxed clock models to accommodate rate variation across the tree. Despite considerable uncertainty in the placement of most fossils, we find that they contribute significantly to the estimation of divergence times in the total-evidence analysis. In particular, the posterior distributions on divergence times are less sensitive to prior assumptions and tend to be more precise than in node dating. The total-evidence analysis also shows that four of the seven Hymenoptera calibration points used in node dating are likely to be based on erroneous or doubtful assumptions about the fossil placement. With respect to the early radiation of Hymenoptera, our results suggest that the crown group dates back to the Carboniferous, ∼309 Ma (95% interval: 291--347 Ma), and diversified into major extant lineages much earlier than previously thought, well before the Triassic. [Bayesian inference; fossil dating; morphological evolution; relaxed clock; statistical phylogenetics.] PMID:22723471

  2. Joint Radiation Emergency Management Plan of the International Organizations. Date Effective: 1 July 2013

    International Nuclear Information System (INIS)

    2013-01-01

    The Convention on Early Notification of a Nuclear Accident (the 'Early Notification Convention') and the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency (the 'Assistance Convention') are prime legal instruments that establish an international framework to facilitate the exchange of information and the prompt provision of assistance in the event of a radiation emergency, with the aim of minimizing the consequences. The International Atomic Energy Agency (IAEA) has specific functions assigned to it under these Conventions, to which the the European Commission, through the European Atomic Energy Community (Euratom), the Food and Agriculture Organization of the United Nations (FAO), the World Health Organization (WHO) and the World Meteorological Organization (WMO) are full Parties. The arrangements between the IAEA, States and international intergovernmental organizations ('international organizations') for facilitating the practical implementation of those articles of the two Conventions that are operational in nature are documented in the IAEA's Operations Manual for Incident and Emergency Communication (IEComm). In addition to the IEComm arrangements and pursuant to the obligations placed on the IAEA by the Conventions, the IAEA regularly convenes the Inter-Agency Committee on Radiological and Nuclear Emergencies (IACRNE), whose purpose is to coordinate the arrangements of the relevant international organizations for preparing for and responding to radiation incidents or emergencies. Although the Conventions assign specific response functions and responsibilities to the IAEA and the Parties, various international organizations have - by virtue of their statutory functions or of related legal instruments (including, for example, the WHO International Health Regulations 2005) - functions and responsibilities that encompass aspects of preparedness and response in this context. Moreover, some regional organizations/bodies (e.g. the

  3. Joint Radiation Emergency Management Plan of the International Organizations. Date Effective: 1 July 2013

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-07-01

    The Convention on Early Notification of a Nuclear Accident (the 'Early Notification Convention') and the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency (the 'Assistance Convention') are prime legal instruments that establish an international framework to facilitate the exchange of information and the prompt provision of assistance in the event of a radiation emergency, with the aim of minimizing the consequences. The International Atomic Energy Agency (IAEA) has specific functions assigned to it under these Conventions, to which the the European Commission, through the European Atomic Energy Community (Euratom), the Food and Agriculture Organization of the United Nations (FAO), the World Health Organization (WHO) and the World Meteorological Organization (WMO) are full Parties. The arrangements between the IAEA, States and international intergovernmental organizations ('international organizations') for facilitating the practical implementation of those articles of the two Conventions that are operational in nature are documented in the IAEA's Operations Manual for Incident and Emergency Communication (IEComm). In addition to the IEComm arrangements and pursuant to the obligations placed on the IAEA by the Conventions, the IAEA regularly convenes the Inter-Agency Committee on Radiological and Nuclear Emergencies (IACRNE), whose purpose is to coordinate the arrangements of the relevant international organizations for preparing for and responding to radiation incidents or emergencies. Although the Conventions assign specific response functions and responsibilities to the IAEA and the Parties, various international organizations have - by virtue of their statutory functions or of related legal instruments (including, for example, the WHO International Health Regulations 2005) - functions and responsibilities that encompass aspects of preparedness and response in this context. Moreover, some regional organizations/bodies (e.g. the

  4. Desinfecção de água de chuva por radiação ultravioleta Disinfection of rainwater by ultraviolet radiation

    Directory of Open Access Journals (Sweden)

    Elisabeth Wisbeck

    2011-12-01

    Full Text Available O objetivo deste trabalho foi avaliar o tratamento de água de chuva, de duas regiões industriais de Joinville (SC, por radiação ultravioleta. O reator operou em processo contínuo, de modo que cada partícula permanecesse sob radiação por 60 segundos. As amostras de água foram analisadas em termos de coliformes totais, coliformes termotolerantes e bactérias heterotróficas antes do tratamento por ultravioleta, após o tratamento e após tratadas e armazenadas por 24, 48 e 72 horas. Verificou-se a eficiência da desinfecção de água de chuva direta e de telhado por radiação ultravioleta com a inativação de 100% dos coliformes totais e dos coliformes termotolerantes e o não recrescimento desses micro-organismos em amostras tratadas e estocados por até 72 horas, no entanto, bactérias heterotróficas persistiram e foram identificadas após 24, 48 e 72 horas ao tratamento.The objective of this study was to evaluate the treatment of rainwater in two industrial regions in Joinville (SC, Brazil by ultraviolet radiation. The reactor was operating in continuous process with each particle remaining under radiation for 60 seconds. The samples were evaluated in terms of total coliforms, fecal coliform and heterotrophic bacteria prior to ultraviolet treatment, after treatment and further treated and stored for 24, 48 and 72 hours. The efficiency of disinfection of direct rainwater and that collected from roofing by ultraviolet radiation was verified with 100% inactivation of total coliforms and fecal coliform and these microorganisms did not reappear in samples treated and stored for up to 72 hours, however, heterotrophic bacteria persisted and were identified after 24, 48 and 72 hours of treatment.

  5. Development of the electrical discharge method for water disinfection

    International Nuclear Information System (INIS)

    Vojtenko, L.M.; Kononov, O.V.; Starchik, P.D.; Samojlenko, L.S.; Stavs'ka, S.S.

    1995-01-01

    Studies of processes of bacterially polluted water disinfection by the method of pulse electrical discharge in water are presented. The studies was performed to improve the disinfection technology. Main attention was concentrated to clear up effect of discharge instability on the disinfection. An influence of the shape and sizes of electrodes on repeatability of discharges was also investigated. It was found that salts solved in water greatly influence ultraviolet radiation absorption coefficients

  6. The efficacy of potassium ferrate as a chemical disinfectant on E. coli, Vibrio cholera, human adenovirus, and Giardia lamblia

    Science.gov (United States)

    Introduction: Drinking water and wastewater go through numerous treatments to remove microorganisms and other contaminants one of many processes along the treatment train is disinfection. There are different ways to disinfect these waters, however to date the most common disinf...

  7. The efficacy of potassium ferrate as a chemical disinfectant on E. coli, Vibrio cholera, human adenovirus, and Giardia lamblia - Abstract

    Science.gov (United States)

    Introduction: Drinking water and wastewater effluents go through numerous treatments to remove microorganisms and other contaminants in the United States. One of many processes along the treatment train is disinfection, and to date the most common disinfectants still remain chemi...

  8. Spiral-shaped disinfection reactors

    KAUST Repository

    Ghaffour, Noreddine

    2015-08-20

    This disclosure includes disinfection reactors and processes for the disinfection of water. Some disinfection reactors include a body that defines an inlet, an outlet, and a spiral flow path between the inlet and the outlet, in which the body is configured to receive water and a disinfectant at the inlet such that the water is exposed to the disinfectant as the water flows through the spiral flow path. Also disclosed are processes for disinfecting water in such disinfection reactors.

  9. Photoreactivation Study of Wastewater Treatment Effluent Disinfected by UV-disinfection for Water Reuse

    International Nuclear Information System (INIS)

    Yoon, C.G.; Jung, K.W.; Ham, J.H.; Jeon, J.H.

    2003-01-01

    Photoreactivation of microorganism following UV-disinfection is one of the research topics of interest in assessing the UV-disinfection performance. Apparent photoreactivation was examined under fluorescent lamp and solar radiation as well as in darkness. Total coliform, fecal coliform, and Escherichia coli were used as indicator microorganisms, and their concentration of 10~30 MPN/100mL increased to the level of 100 MPN/100mL after 24 hours, which implied that part of damaged microorganisms by UV-disinfection might be repairable with time

  10. ASTRO's Advances in Radiation Oncology: Success to date and future plans

    Directory of Open Access Journals (Sweden)

    Robert C. Miller, MD, MBA, FASTRO

    2017-07-01

    Full Text Available ASTRO's Advances in Radiation Oncology was launched as a new, peer-reviewed scientific journal in December 2015. More than 200 manuscripts have been submitted and 97 accepted for publication as of May 2017. As Advances enters its second year of publication, we have chosen to highlight subjects that will transform the way we practice radiation oncology in special issues or ongoing series: immunotherapy, biomedical analytics, and social media. A teaching case report contest for North American radiation oncology residents will be launched at American Society of Radiation Oncology 2017 to encourage participation in scientific publication by trainees early in their careers. Recognizing our social mission, Advances will also begin a series of articles devoted to highlighting the growing disparities in access to radiation oncology services in vulnerable populations in North America. We wish to encourage the American Society of Radiation Oncology membership to continue its support of the journal through high-quality manuscript submission, participation in the peer review process, and highlighting important manuscripts through sharing on social media.

  11. Standardization of methods for microbiological examination of sludges in the special outlook of disinfection by ionizing radiations

    International Nuclear Information System (INIS)

    Alexandre, D.; Charrel, J.; Blancard, A.

    1978-01-01

    Scattering and difficulties in the interpretation of data regarding the level of radiation doses required for inactivation of microorganisms encountered in waste water and sludge, is due, in great part, to the lack of precision in operational conditions and to the diversity in analytical methods. After reminding the importance of the main physical and chemical parameters characterizing the media and liable to change the radio sensitivity of present germs, authors review the different methods used in microbiology for isolation and counting of the most generally studied microorganisms in view of standardization. (Auth.)

  12. Wholesomeness studies with a full diet of irradiated dates, using the insect ephestia Cautella: 1. Disinfestation doses of gamma radiation

    International Nuclear Information System (INIS)

    Al-Hakkak, Z.S.; Ali, S.R.; Ahmed, M.S.H.; Al-Maliky, S.K.

    1983-01-01

    The study deals with the effect of feeding irradiated dates as a whole diet on some biological parameters of the fig moth ephestia cautella. Statistical analyses of the results indicated that the differences in the undermentioned parameters were insignificant when measured and compared with insects reared wholly either on irradiated or on unirradiated dry dates fruits. 1. Average numbers of larvae and pupae produced out of 400 seeded eggs after 30 days of incubation. 2. Average percentage of adult survival and their sex-ratio. 3. Mating frequency (average number of spermatophores per female) of the survived adults. 4. Average number of eggs laid per female. 5. Average percentage of eggs hatchability. 6. Mating frequency, average number of eggs per female and average percentage of egg hatchability of F1 progeny adults produced from insect parents reared on 100% diet of irradiated as well as on unirradiated dates. Therefore it could be concluded that disinfestation of date fruits by such a range of doses (50-100 krad) of gamma radiation might not have any adverse effect on the fig moth

  13. Spiral-shaped disinfection reactors

    KAUST Repository

    Ghaffour, NorEddine; Ait-Djoudi, Fariza; Naceur, Wahib Mohamed; Soukane, Sofiane

    2015-01-01

    This disclosure includes disinfection reactors and processes for the disinfection of water. Some disinfection reactors include a body that defines an inlet, an outlet, and a spiral flow path between the inlet and the outlet, in which the body

  14. [Response of indica rice spikelet differentiation and degeneration to air temperature and solar radiation of different sowing dates].

    Science.gov (United States)

    Wang, Ya Liang; Zhang, Yu Ping; Xiang, Jing; Wang, Lei; Chen, Hui Zhe; Zhang, Yi Kai; Zhang, Wen Qian; Zhu, De Feng

    2017-11-01

    In this study, three rice varieties, including three-line hybrid indica rice Wuyou308 and Tianyouhuazhan, and inbred indica rice Huanghuazhan were used to investigate the effects of air temperature and solar radiation on rice growth duration and spikelet differentiation and degeneration. Ten sowing-date treatments were conducted in this field experiment. The results showed that the growth duration of three indica rice varieties were more sensitive to air temperature than to day-length. With average temperature increase of 1 ℃, panicle initiation advanced 1.5 days, but the panicle growth duration had no significant correlation with the temperature and day-length. The number of spikelets and differentiated spikelets revealed significant differences among different sowing dates. Increases in average temperature, maximum temperature, minimum temperature, effective accumulated temperature, temperature gap and the solar radiation benefited dry matter accumulation and spikelet differentiation of all varieties. With increases of effective accumulated temperature, diurnal temperature gap and solar radiation by 50 ℃, 1 ℃, 50 MJ·m -2 during panicle initiation stage, the number of differentiated spikelets increased 10.5, 14.3, 17.1 respectively. The rate of degenerated spikelets had a quadratic correlation with air temperature, extreme high and low temperature aggravated spikelets degeneration, and low temperature stress made worse effect than high temperature stress. The rate of spikelet degeneration dramatically rose with the temperature falling below the critical temperature, the critical effective accumulated temperature, daily average temperature, daily maximum temperature and minimum temperature during panicle initiation were 550-600 ℃, 24.0-26.0 ℃, 32.0-34.0 ℃, 21.0-23.0 ℃, respectively. In practice, the natural condition of appropriate high temperature, large diurnal temperature gap and strong solar radiation were conducive to spikelet differentiation

  15. A pilot solar water disinfecting system: performance analysis and testing

    Energy Technology Data Exchange (ETDEWEB)

    Saitoh, T.S.; El-Ghetany, H.H. [Tohoku University, Sendai (Japan). Dept. of Aeronautics and Space Engineering

    2002-07-01

    In most countries, contaminated water is the major cause of most water-borne diseases. Disinfection of water may be accomplished by a number of different physical-chemical treatments including direct application of thermal energy, chemical and filtration techniques. Solar energy also can be used effectively in this field because inactivation of microorganisms is done either by heating water to a disinfecting temperature or by exposing it to ultraviolet solar radiation. A pilot solar system for disinfecting contaminated water is designed, constructed and tested. Investigations are carried out to evaluate the performance of a wooden hot box solar facility as a solar disinfectant. Experimental data show that solar energy is viable for the disinfection process. A solar radiation model is presented and compared with the experimental data. A mathematical model of the solar disinfectant is also presented. The governing equations are solved numerically via the fourth-order Runge-Kutta method. The effects of environmental conditions (ambient temperature, wind speed, solar radiation, etc.) on the performance of the solar disinfectant are examined. Results showed that the system is affected by ambient temperature, wind speed, ultraviolet solar radiation intensity, the turbidity of the water, the quantity of water exposed, the contact area between the transparent water container in the solar disinfectant and the absorber plate as well as the geometrical parameters of the system. It is pointed out that for partially cloudy conditions with a low ambient temperature and high wind speeds, the thermal efficiency of the solar disinfectant is at a minimum. The use of solar energy for the disinfection process will increase the productivity of the system while completely eliminating the coliform group bacteria at the same time. (author)

  16. Applications of Photocatalytic Disinfection

    Directory of Open Access Journals (Sweden)

    Joanne Gamage

    2010-01-01

    Full Text Available Due to the superior ability of photocatalysis to inactivate a wide range of harmful microorganisms, it is being examined as a viable alternative to traditional disinfection methods such as chlorination, which can produce harmful byproducts. Photocatalysis is a versatile and effective process that can be adapted for use in many applications for disinfection in both air and water matrices. Additionally, photocatalytic surfaces are being developed and tested for use in the context of “self-disinfecting” materials. Studies on the photocatalytic technique for disinfection demonstrate this process to have potential for widespread applications in indoor air and environmental health, biological, and medical applications, laboratory and hospital applications, pharmaceutical and food industry, plant protection applications, wastewater and effluents treatment, and drinking water disinfection. Studies on photocatalytic disinfection using a variety of techniques and test organisms are reviewed, with an emphasis on the end-use application of developed technologies and methods.

  17. ESR dating of elephant teeth and radiation dose rate estimation in soil

    International Nuclear Information System (INIS)

    Taisoo Chong; Ohta, Hiroyuki; Nakashima, Yoshiyuki; Iida, Takao; Saisho, Hideo

    1989-01-01

    Chemical analysis of 238 U, 232 Th and 40 K in the dentine as well as enamel of elephant tooth fossil has been carried out in order to estimate the internal absorbed dose rate of the specimens, which was estimated to be (39±4) mrad/y on the assumption of early uptake model of radionuclides. The external radiation dose rate in the soil including the contribution from cosmic rays was also estimated to be (175±18) mrad/y with the help of γ-ray spectroscopic techniques of the soil samples in which the specimens were buried. The 60 Co γ-ray equivalent accumulated dose of (2±0.2) x 10 4 rad for the tooth enamel gave ''ESR age'' of (9±2) x 10 4 y, which falls in the geologically estimated range between 3 x 10 4 and 30 x 10 4 y before the present. (author)

  18. Joint Radiation Emergency Management Plan of the International Organizations. Date Effective: 1 January 2010

    International Nuclear Information System (INIS)

    2010-01-01

    The purpose of this Plan is to describe the inter-agency framework for preparedness for and response to a radiation5 incident or emergency irrespective of its cause. In particular, its objectives are: 1. To provide a common understanding of the emergency preparedness and response roles and responsibilities, objectives, authorities, capabilities and arrangements of each participating international organization, and any relevant inter-agency arrangements; 2. To provide an overall concept of operations between the international organizations based on the emergency response objectives, responsibilities, authorities, capabilities and arrangements of each participating international organization, and any existing inter-agency arrangements, in order to facilitate a timely, effective and co-ordinated response; 3. To facilitate development of agreements among the participating international organizations on practical issues, if appropriate; 4. To provide a common understanding of the process for improving and changing the inter-agency response arrangements; 5. To provide a common understanding of roles and responsibilities of the participating international organizations with respect to: international standards, supporting national capabilities through provision of guidance and training, relevant research, emergency exercises and other preparedness considerations; 6. To guide the managers in each participating organization who need to ensure that all appropriate arrangements are given the necessary support within their organization; 7. To facilitate the well founded development, maintenance and training of plans and procedures for each organization; 8. To draw the attention of personnel in States and international organizations6 to these arrangements and to facilitate the development of compatible arrangements, if appropriate. The Joint Plan describes the arrangements of the participating international organizations7 for responding to a radiation incident or emergency

  19. Thermoluminescence dating

    International Nuclear Information System (INIS)

    Price, D.M.

    1999-01-01

    Thermoluminescence (TL) dating of sediments depends upon the acquisition and long term stable storage of TL energy by crystalline minerals contained within a sedimentary unit. This energy is stored in the form of trapped electrons and quartz sand is the most commonly used mineral employed in the dating process. Prior to the final depositional episode it is necessary that any previously acquired TL is removed by exposure to sunlight. After burial the TL begins to build up again at a rate dependent upon the radiation flux delivered by long-lived isotopes of uranium, thorium and potassium. The presence of rubidium and cosmic radiation generally play a lesser but contributory roll, and the total radiation dose delivered to the TL phosphor is modified by the presence of water. The period since deposition is therefore measured by determining the total amount of stored TL energy, the palaeodose (P), and the rate at which this energy is acquired, the annual radiation dose (ARD). TL dating may be applied to eolian, fluvial, coastal and in some cases, marine sediments. the technique is also successfully applied to volcanic materials and to a certain extent to archeological specimens

  20. Intracellular mechanisms of solar water disinfection

    Science.gov (United States)

    Castro-Alférez, María; Polo-López, María Inmaculada; Fernández-Ibáñez, Pilar

    2016-12-01

    Solar water disinfection (SODIS) is a zero-cost intervention measure to disinfect drinking water in areas of poor access to improved water sources, used by more than 6 million people in the world. The bactericidal action of solar radiation in water has been widely proven, nevertheless the causes for this remain still unclear. Scientific literature points out that generation of reactive oxygen species (ROS) inside microorganisms promoted by solar light absorption is the main reason. For the first time, this work reports on the experimental measurement of accumulated intracellular ROS in E. coli during solar irradiation. For this experimental achievement, a modified protocol based on the fluorescent probe dichlorodihydrofluorescein diacetate (DCFH-DA), widely used for oxidative stress in eukaryotic cells, has been tested and validated for E. coli. Our results demonstrate that ROS and their accumulated oxidative damages at intracellular level are key in solar water disinfection.

  1. Humidifier disinfectants, unfinished stories

    Directory of Open Access Journals (Sweden)

    Yeyong Choi

    2016-02-01

    Full Text Available 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.

  2. Environmental cleaning and disinfection.

    Science.gov (United States)

    Traverse, Michelle; Aceto, Helen

    2015-03-01

    The guidelines in this article provide veterinarians, veterinary technicians, and veterinary health care workers with an overview of evidence-based recommendations for the best practices associated with environmental cleaning and disinfection of a veterinary clinic that deals with small animals. Hospital-associated infections and the control and prevention programs necessary to alleviate them are addressed from an environmental perspective. Measures of hospital cleaning and disinfection include understanding mechanisms and types of contamination in veterinary settings, recognizing areas of potential concern, addressing appropriate decontamination techniques and selection of disinfectants, the management of potentially contaminated equipment, laundry, and waste management, and environmental surveillance strategies. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Inverted Apatite (U-Th)/He and Fission-track Dates from the Rae craton, Baffin Island, Canada and Implications for Apatite Radiation Damage-He Diffusivity Models

    Science.gov (United States)

    Ault, A. K.; Reiners, P. W.; Thomson, S. N.; Miller, G. H.

    2015-12-01

    Coupled apatite (U-Th)/He and fission-track (AFT) thermochronology data from the same sample can be used to decipher complex low temperature thermal histories and evaluate compatibility between these two methods. Existing apatite He damage-diffusivity models parameterize radiation damage annealing as fission-track annealing and yield inverted apatite He and AFT dates for samples with prolonged residence in the He partial retention zone. Apatite chemistry also impacts radiation damage and fission-track annealing, temperature sensitivity, and dates in both systems. We present inverted apatite He and AFT dates from the Rae craton, Baffin Island, Canada, that cannot be explained by apatite chemistry or existing damage-diffusivity and fission track models. Apatite He dates from 34 individual analyses from 6 samples range from 237 ± 44 Ma to 511 ± 25 Ma and collectively define a positive date-eU relationship. AFT dates from these same samples are 238 ± 15 Ma to 350 ± 20 Ma. These dates and associated track length data are inversely correlated and define the left segment of a boomerang diagram. Three of the six samples with 20-90 ppm eU apatite grains yield apatite He and AFT dates inverted by 300 million years. These samples have average apatite Cl chemistry of ≤0.02 wt.%, with no correlation between Cl content and Dpar. Thermal history simulations using geologic constraints, an apatite He radiation damage accumulation and annealing model, apatite He dates with the range of eU values, and AFT date and track length data, do not yield any viable time-temperature paths. Apatite He and AFT data modeled separately predict thermal histories with Paleozoic-Mesozoic peaks reheating temperatures differing by ≥15 °C. By modifying the parameter controlling damage annealing (Rmr0) from the canonical 0.83 to 0.5-0.6, forward models reproduce the apatite He date-eU correlation and AFT dates with a common thermal history. Results imply apatite radiation damage anneals at

  4. Phylogeny and divergence-date estimates of rapid radiations in muroid rodents based on multiple nuclear genes.

    Science.gov (United States)

    Steppan, Scott; Adkins, Ronald; Anderson, Joel

    2004-08-01

    The muroid rodents are the largest superfamily of mammals, containing nearly one third of all mammal species. We report on a phylogenetic study comprising 53 genera sequenced for four nuclear genes, GHR, BRCA1, RAG1, and c-myc, totaling up to 6400 nucleotides. Most relationships among the subfamilies are resolved. All four genes yield nearly identical phylogenies, differing only in five key regions, four of which may represent particularly rapid radiations. Support is very strong for a fundamental division of the mole rats of the subfamilies Spalacinae and Rhizomyinae from all other muroids. Among the other "core" muroids, a rapid radiation led to at least four distinct lineages: Asian Calomyscus, an African clade of at least four endemic subfamilies, including the diverse Nesomyinae of Madagascar, a hamster clade with maximum diversity in the New World, and an Old World clade including gerbils and the diverse Old World mice and rats (Murinae). The Deomyinae, recently removed from the Murinae, is well supported as the sister group to the gerbils (Gerbillinae). Four key regions appear to represent rapid radiations and, despite a large amount of sequence data, remain poorly resolved: the base of the "core" muroids, among the five cricetid (hamster) subfamilies, within a large clade of Sigmodontinae endemic to South America, and among major geographic lineages of Old World Murinae. Because of the detailed taxon sampling within the Murinae, we are able to refine the fossil calibration of a rate-smoothed molecular clock and apply this clock to date key events in muroid evolution. We calculate rate differences among the gene regions and relate those differences to relative contribution of each gene to the support for various nodes. The among-gene variance in support is greatest for the shortest branches. We present a revised classification for this largest but most unsettled mammalian superfamily.

  5. Disinfection of drinking water

    International Nuclear Information System (INIS)

    Ensenauer, P.

    1977-01-01

    Some methods for disinfecting drinking water are described, e.g. UV irradiation (optimal wavelength 210-250mm) with the advantage of constant water composition and the resulting danger of re-infection. (AJ) [de

  6. Disinfection of drinking water

    Energy Technology Data Exchange (ETDEWEB)

    Ensenauer, P

    1977-01-01

    Some methods for disinfecting drinking water are described, e.g. UV irradiation (optimal wavelength 210-250mm) with the advantage of constant water composition and the resulting danger of re-infection.

  7. Ultraviolet light - nature's own disinfection process

    Energy Technology Data Exchange (ETDEWEB)

    Munkeberg, T [Thorolf Gregersen a/s, Oslo (Norway)

    1978-05-18

    Ultraviolet radiation from the sun is the means by which natural pollution products, as well as much of the smaller amount of pollution products produced by man, are converted and returned to the cycle of nature. Artificial ultraviolet radiation offers an optimum method for the disinfection of drinking water and can be used in the long term without undesireable effects on man or the enviromment. There is no evidence that ultraviolet irradiation leads to radiation resistant mutations of bacteria. The geometrical arrangement of ultraviolet disinfection units is described and the capacities of typical units is mentioned as being 600-800 m/sup 3/ /hr, though there is no reason why this should not be increased.

  8. Ultraviolet light - nature's own disinfection process

    International Nuclear Information System (INIS)

    Munkeberg, T.

    1978-01-01

    Ultraviolet radiation from the sun is the means by which natural pollution products, as well as much of the smaller amount of pollution products produced by man, are converted and returned to the cycle of nature. Artificial ultraviolet radiation offers an optimum method for the disinfection of drinking water and can be used in the long term without undesireable effects on man or the enviromment. There is no evidence that ultraviolet irradiation leads to radiation resistant mutations of bacteria. The geometrical arrangement of ultraviolet disinfection units is described and the capacities of typical units is mentioned as being 600-800 m 3 /hr, though there is no reason why this should not be increased. (JIW)

  9. Emergency Disinfection of Drinking Water

    Science.gov (United States)

    How to boil and disinfect water to kill most disease-causing microorganisms during emergency situations where regular water service has been interrupted and local authorities recommend using only bottled water, boiled water, or disinfected water.

  10. Copper disinfection ban causes storm.

    Science.gov (United States)

    Lester, Alan

    2013-05-01

    Since 1 February this year, under the EU's Biocidal Products Directive, it has been illegal to sell or use water treatment systems that use elemental copper, a practice employed historically by a significant number of UK healthcare facilities to combat Legionella. Alan Lester, managing director of specialist supplier of 'environmentally-friendly' water treatment systems, Advanced Hydro, says the ban has caused 'a storm of giant proportion,' with advocates of copper ion-based treatment systems arguing that this disinfection method dates back 3,000 years to Egyptian times, making it an 'undoubtedly proven' technology. Here he explains why the ban came into force, considers why the UK's Health and Safety Executive (HSE) is seeking a derogation, looks at the ban's likely impact, and gives a personal viewpoint on the 'pros and cons' of some of the alternative treatment technologies, including a titanium dioxide-based system marketed by Advanced Hydro itself in the UK.

  11. Disinfection of drinking water by ultraviolet light

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    It is no longer mandatory that a given residue of chlorine is present in drinking water and this has led to interest in the use of ultraviolet radiation for disinfection of water in large public waterworks. After a brief discussion of the effect of ultraviolet radiation related to wavelength, the most usual type of irradiation equipment is briefly described. Practioal considerations regarding the installation, such as attenuation of the radiation due to water quality and deposits are presented. The requirements as to dose and residence time are also discussed and finally it is pointed out that hydraulic imperfections can reduce the effectiveness drastically. (JIW)Ψ

  12. Disinfection by electrohydraulic treatment.

    Science.gov (United States)

    Allen, M; Soike, K

    1967-04-28

    Electrohydraulic treatment was applied to suspensions of Escherichia coli, spores of Bacillus subtilis var. niger, Saccharomyces cerevisiae, and bacteriophage T2 at an input energy that, in most cases, was below the energy required to sterilize. The input energy was held relatively constant for each of these microorganisms, but the capacitance and voltage were varied. Data are presented which show the degree of disinfection as a function of capacitance and voltage. In all cases, the degree of disinfection for a given input energy increases as both capacitance and voltage are lowered.

  13. Water disinfection agents and disinfection by-products

    Science.gov (United States)

    Ilavský, J.; Barloková, D.; Kapusta, O.; Kunštek, M.

    2017-10-01

    The aim of this work is to describe factors of water quality change in the distribution network and legislative requirements in Slovakia for disinfectants and disinfection byproducts (DBPs). In the experimental part, the time dependence of the application of the chlorine dioxide and sodium hypochlorite on the formation of some by-products of disinfection for drinking water from WTP Hriňová is studied. We monitored trihalomethanes, free chlorine, chlorine dioxide and chlorites.

  14. Reduction of date microbial load with ozone

    Science.gov (United States)

    Farajzadeh, Davood; Qorbanpoor, Ali; Rafati, Hasan; Isfeedvajani, Mohsen Saberi

    2013-01-01

    Background: Date is one of the foodstuffs that are produced in tropical areas and used worldwide. Conventionally, methyl bromide and phosphine are used for date disinfection. The toxic side effects of these usual disinfectants have led food scientists to consider safer agents such as ozone for disinfection, because food safety is a top priority. The present study was performed to investigate the possibility of replacing common conventional disinfectants with ozone for date disinfection and microbial load reduction. Materials and Methods: In this experimental study, date samples were ozonized for 3 and 5 hours with 5 and 10 g/h concentrations and packed. Ozonized samples were divided into two groups and kept in an incubator which was maintained at 25°C and 40°C for 9 months. During this period, every 3 month, microbial load (bacteria, mold, and yeast) were examined in ozonized and non-ozonized samples. Results: This study showed that ozonization with 5 g/h for 3 hours, 5 g/h for 5 hours, 10 g/h for 3 hours, and 10 g/h for 5 hours leads to about 25%, 25%, 53%, and 46% reduction in date mold and yeast load and about 6%, 9%, 76%, and 74.7% reduction in date bacterial load at baseline phase, respectively. Appropriate concentration and duration of ozonization for microbial load reduction were 10 g/h and 3 hours. Conclusion: Date ozonization is an appropriate method for microbial load reduction and leads to an increase in the shelf life of dates. PMID:24124432

  15. Economic evaluation of slurry-, sewage-sludge, and crop disinfection facility applications based on industrial accelerator and 60Co radiation source

    International Nuclear Information System (INIS)

    Abelovszky, L.

    1979-01-01

    The degree of the compliance with the requirements of slurry and sewage treatment, the range of use of radiation sterilization procedures in agriculture and food industry, the possibilities of the complex application of radiation methods and factors influencing their economic efficiency, the economic evaluation of the versatile chargeable accelerators, the fixed and semi-mobile radioisotope facilities, the economic efficiency of the multipurpose utilization, the differences in the application of accelerators and radio isotopes as to the power source applied, the penetration, the dose rates and the radiation energy focusing are discussed. The radiation facility costs are compared. Conclusions concerning the choice of the most efficient applications are given. (author)

  16. Spiral-shaped reactor for water disinfection

    KAUST Repository

    Soukane, Sofiane; Ait-Djoudi, Fariza; Naceur, Wahib M.; Ghaffour, NorEddine

    2016-01-01

    Chlorine-based processes are still widely used for water disinfection. The disinfection process for municipal water consumption is usually carried out in large tanks, specifically designed to verify several hydraulic and disinfection criteria

  17. A review on wastewater disinfection

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Amin

    2013-01-01

    Full Text Available Changes in regulations and development of new technologies have affected the selection of alternative for treated wastewater disinfection. Disinfection is the last barrier of wastewater reclamation process to protect ecosystem safety and human health. Driving forces include water scarcity and drinking water supply, irrigation, rapid industrialization, using reclaimed water, source protection, overpopulation, and environmental protection. The safe operation of water reuse depends on effluent disinfection. Understanding the differences in inactivation mechanisms is critical to identify rate-limiting steps involved in the inactivation process as well as to develop more effective disinfection strategies. Disinfection byproducts discharged from wastewater treatment plants may impair aquatic ecosystems and downstream drinking-water quality. Numerous inorganic and organic micropollutants can undergo reactions with disinfectants. Therefore, to mitigate the adverse effects and also to enhance that efficiency, the use of alternative oxidation/disinfection systems should be evaluated as possible alternative to chlorine. This review gives a summary of the traditional, innovative, and combined disinfection alternatives and also disinfection byproducts for effluent of municipal wastewater treatment plants.

  18. Dating Violence

    Science.gov (United States)

    ... for Teens / Dating Violence Bulletins for Teens: Dating Violence What is it? If you are a victim ... often. If You Are a Victim of Dating Violence, You Might… Think it's your fault. Feel angry, ...

  19. Solar water disinfecting system using compound parabolic concentrating collector

    Energy Technology Data Exchange (ETDEWEB)

    El-Ghetany, H.H.; Saitoh, T.S. [Tohoku Univ., Sendai (Japan)

    2000-05-31

    Solar water disinfection is an alternative technology using solar radiation and thermal treatment to inactivate and destroy pathogenic microorganisms present in water. The Compound Parabolic Concentrating, (CPC) collector can be used as an efficient key component for solar disinfectanting system. Two types of the CPC collectors are studied, namely the transparent-tube and the Copper-tube CPC collector. It is found that after 30 minutes of exposing the water sample to solar radiation or heating it up to 65 degree C for a few minuets all the coliform bacterial present in the contaminated water sample were completely eliminated. In this article, the effect of water temperature on the disinfecting process was presented. Thermal and micro-biological measurements were also made to evaluate the system performance. (author)

  20. Joint radiation emergency management plan of the international organizations. Emergency preparedness and response. Date effective: 1 January 2007

    International Nuclear Information System (INIS)

    2007-01-01

    prompt provision of information and assistance. This document is the fourth edition of the Joint Plan. The third edition was co-sponsored by the European Commission, EUROPOL, FAO, IAEA, INTERPOL, OCHA, OECD/NEA, OOSA, PAHO, UNEP, WHO and WMO in co-operation with the International Civil Aviation Organization (ICAO). The present edition is additionally co-sponsored by the International Maritime Organization (IMO) and in co-operation with United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The Joint Plan does not prescribe arrangements between the participating organizations, but describes a common understanding of how each organization acts during a response and in making preparedness arrangements. It describes the arrangements as envisaged from 1 December 2006, by which time each participating organization needs to have initiated the steps necessary for harmonizing its own response plans and arrangements with the 2006 edition. The subsequent edition is envisaged for release in December 2008. Although a controlled distribution list is maintained for the Joint Plan and any amendments, it is not restricted in its availability. An up-to-date version is maintained on the IAEA's public web site under http://www-ns.iaea.org/tech-areas/emergency/inter-liaison.htm

  1. The preparation and characterization of a loess sediment reference material for QC/QA of the annual radiation dose determination in luminescence dating

    International Nuclear Information System (INIS)

    De Corte, F.; De Wispelaere, A.; Vandenberghe, D.; Hossain, S.M.; Van den haute, P.

    2005-01-01

    Of crucial importance for obtaining reliable results in the luminescence dating of sediments, is the accurate and precise assessment of both the palaeodose and the annual radiation dose [cf the age equation: luminescence-age (ka) = palaeodose (Gray)/annual radiation dose (Gray.ka -1 )]. Clearly, for QC/QA of the annual radiation dose determination, a sediment reference material - not readily available up to now - would be highly useful. Therefore, in the present work a loess sediment was prepared and characterized with well-defined K, Th and U contents (the radiation dose being built up mainly by 40 K, and by 232 Th and 235,238 U and their decay daughters) and - otherwise expressed - alpha, beta, gamma and total radiation dose-rates. The material, a fine-grained aeolian loess sediment deposited in the Young-Pleistocene (Weichselian), a part of the Quaternary, was collected at Volkegem, Belgium. At the sampling site, NaI(Tl) field gamma-ray spectrometry was performed, yielding - via comparison with the 'Heidelberg calibration block' - concentrations (wet loess weight) for K, Th and U. About 14 kg material was brought to the laboratory and kept for ∼1 week at 110 degree C until constant weight (water content ≅14%). Then, the dried loess was subject to agate ball milling so as to pass through a 50 μm sieve. The ∼12 kg powder obtained in this way was homogenized both in a turbula mixer and manually. For the thus prepared loess material, good homogeneity for its K, Th and U content was found, as investigated via k 0 -INAA. For the final concentration and radiation dose-rate characterization, use was made of (next to NaI(Tl) field gamma-ray spectrometry and k 0 -INAA): extended energy-range low-background Ge gamma-ray spectrometry (also showing that the 232 Th and 238 U decay series were in secular equilibrium), thick source ZnS alpha-counting and GM beta-counting. For the latter', the conversion factors 'beta count-rate mutually implies radiation dose-rate' were

  2. A survey of the signal stability and radiation dose response of sulfates in the context of adapting optical dating for Mars

    International Nuclear Information System (INIS)

    O'Connor, V.A.; Lepper, K.; Morken, T.O.; Thorstad, D.J.; Podoll, A.; Giles, M.J.

    2011-01-01

    The Martian landscape is currently dominated by eolian processes, and eolian dunes are a direct geomorphic expression of the dynamic interaction between the atmosphere and the lithosphere of planets. The timing, frequency, and spatial extent of dune mobility directly reflects changing climatic conditions, therefore, sedimentary depositional ages are important for understanding the paleoclimatic and geomorphologic history of features and processes present on the surface of the Earth or Mars. Optical dating is an established terrestrial dosimetric dating technique that is being developed for this task on Mars. Gypsum and anhydrite are two of the most stable and abundant sulfate species found on the Earth, and they have been discovered in Martian sediments along with various magnesium sulfates and jarosite. In this study, the optical dating properties of various Ca-, Mg-, and Fe-bearing sulfates were documented to help evaluate the influence they may have on in-situ optical dating in eolian environments on Mars. Single-aliquot regenerative-dose (SAR) experimental procedures have been adapted to characterize the radiation dose response and signal stability of the Martian sulfate analogs. Jarosite was dosimetrically inert in our experiments. The radiation dose response of the Ca- and Mg-sulfates was monotonically increasing in all cases with characteristic doses ranging from ∼100 to ∼1000 Gy. Short-term signal fading also varied considerably in the Ca- and Mg-sulfates ranging from ∼0% to ∼40% per decade for these materials. These results suggest that the OSL properties of Ca- and Mg-sulfates will need to be considered when developing protocols for in-situ optical dating on Mars, but more enticingly, our results foreshadow the potential for gypsum to be developed as a geochronometer for Mars or the Earth. - Highlights: → The radiation dose response and OSL signal stability of Ca- and Mg-sulfates was highly variable. → OSL properties of Ca- and Mg

  3. Sanitizers and Disinfectants Guide. Revised

    Science.gov (United States)

    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…

  4. Irradiation as an alternative for disinfection of domestic waste in the Canadian Arctic

    International Nuclear Information System (INIS)

    1981-01-01

    This study evaluated the technical and economic feasibility of various methods for disinfecting wastewater in the Canadian Arctic with specific reference to gamma radiation. More conventional disinfection practices, such as chlorination, chlorination-dechlorination, and ozonation were compared to gamma radiation along with ultraviolet irradiation and lime disinfection. The quality of lagoon effluent, highly diluted (weak) sewage, holding tank wastes and honey-bag wastes, which are the typical waste types found in northern communities, was established from data available in the literature. Further literature reviews were undertaken to establish a data base for design and effectiveness of disinfection systems operated in cold climates. Capital and operating costs for all technically feasible disinfection process alternates were estimated based on historical cost data adjusted to 1977 for the construction and instalation of similar systems in the north. The costs of equipment, chemicals, fuel and electrical power were obtained from suppliers. The environmental impact of each of the disinfection processes was reviewed with emphasis on gamma irradiation. Safety and health aspects were also considered. The study concluded that gamma irradiation was capable of providing safe, reliable disinfection for concentrated honey-bag and holding wastes. Pilot-scale testing was recommended prior to construction of full-scale disinfection facilities. For lagoon effluents and weak sewage, gamma irradiation was not cost competitive with other alternates; rather chlorination-dechlorination was found to be the most cost-effective and environmentally acceptable alternative

  5. Radiocarbon dating of samples for archaeologic and geologic interesting by liquid scintillation spectrometry with low background radiation

    International Nuclear Information System (INIS)

    Pessenda, L.C.R.; Camargo, P.B. de

    1991-01-01

    An analytical system for radiocarbon dating of environmental samples using low level liquid scintillation counting spectrometry was developed at the Center for Nuclear Energy in Agriculture, University of Sao Paulo. Physical and chemical pretreatment and benzene synthesis of samples, counting procedure, optimization of analytical parameters and laboratory intercomparison with radiocarbon laboratories of Center for Applied Isotope Studies, University of Georgia, USA and University of Waterloo, Canada, are described. (author)

  6. 40 CFR 141.72 - Disinfection.

    Science.gov (United States)

    2010-07-01

    ... PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.72 Disinfection. A public water... the direct influence of surface water and provides filtration treatment must provide disinfection...) Disinfection requirements for public water systems which provide filtration. Each public water system that...

  7. Dating Violence

    Science.gov (United States)

    Stader, David L.

    2011-01-01

    Dating violence is a form of student-on-student victimization and is a serious school safety issue. Research indicates that at a minimum, 10 percent of high school students are victims of dating violence in one form or another. Among female high school students that date, some data indicate that as many as 30 percent may be victims of dating…

  8. Role of ultraviolet (UV) disinfection in infection control and environmental cleaning.

    Science.gov (United States)

    Qureshi, Zubair; Yassin, Mohamed H

    2013-06-01

    Ultraviolet (UV) radiation is capable of disinfecting surfaces, water and air. The UV technology was used for many years. However, safer and more effective delivery systems of UV radiation, make it a very useful option for disinfection. Effective disinfection of environmental surfaces is a key step in the prevention of spread of infectious agents. The traditional manual cleaning is essential in assuring adequate elimination of contamination. However, terminal cleaning is frequently suboptimal or unpredictable in many circumstances. UV-C radiation is an adjunctive disinfectant new technology that could kill a wide array of microorganisms including both vegetative and spore forming pathogens. The technology is getting more affordable and has produced consistent reproducible significant reduction of bacterial contamination.

  9. Up-to-date status of ionizing radiation influence issue on testes and gland-gonads system. Chapter 4

    International Nuclear Information System (INIS)

    2000-01-01

    In the chapter the analytical survey on ionizing radiation action on men sexual function is made. It is known, that the ionizing irradiation destructs both the sexual and the reproductive functions of men. Literature analysis indicates on high frequency of liquidators' complaints on sexual dysfunctions, and that the problem of clinical and pathogenetic regularities of sexual dysfunctions is unexplored. It is noted, that this problem is not only medical problem but it is the social one

  10. Solar disinfection of water for low income communities; Desinfeccao solar de agua para comunidades de baixa renda

    Energy Technology Data Exchange (ETDEWEB)

    Felix, Lorna Falcao

    2010-03-15

    The use of solar energy for water disinfection, and is accessible to disadvantaged communities because of its low cost, has the advantage of using disposable materials such as bottles of polyethylene terephthalate (PET). We present a study that used two methods of disinfection: the methodology proposed by the project Solar Water Disinfection (SODIS), which consisted of water disinfection by solar radiation and temperature and the methodology which the temperature of the water for disinfection. In both, we seek to eliminate microorganisms that cause serious diseases such as dysentery, typhoid, cholera, etc. Water samples were collected in the community of Bass, where the population has low income and the incidence of waterborne diseases is high. The experiments were divided into two stages. In step 1 we studied the feasibility of disinfection and in step 2 the feasibility of the pilot plant to obtain adequate levels of disinfection temperatures desired. The results showed the efficiency of the disinfection process, reaching an average of 80 to 100% death of microorganisms, but regrowth was observed in some samples. Finally on the good results of stage 1, is designed and built and tested in an experimental pilot plant, which has shown to be feasible to promote water disinfection through the use of solar energy. The water after treatment is in accordance with the limits established by Brazilian legislation for clean water, maintaining a positive performance for the disinfection and acceptable levels of bacterial regrowth. (author)

  11. A review on wastewater disinfection

    OpenAIRE

    Mohammad Mehdi Amin; Hassan Hashemi; Amir Mohammadi Bovini; Yung Tse Hung

    2013-01-01

    Changes in regulations and development of new technologies have affected the selection of alternative for treated wastewater disinfection. Disinfection is the last barrier of wastewater reclamation process to protect ecosystem safety and human health. Driving forces include water scarcity and drinking water supply, irrigation, rapid industrialization, using reclaimed water, source protection, overpopulation, and environmental protection. The safe operation of water reuse depends on effluent d...

  12. Disinfection of treated sewage. [Ultra-violet irradiation

    Energy Technology Data Exchange (ETDEWEB)

    From, J O

    1976-09-02

    The release of treated sewage in the vicinity of bathing places, drinking water sources or fish and shellfish culture plants is undesirable due to high bacterial content. Disinfection by chlorine would be relatively expensive and the toxicity would result in a local dead zone. The formation of small, but measurable, amounts of persistent chlorated hydrocarbons could also lead to long-term biological effects. Disinfection by ozone or gamma radiation would involve investments unacceptable in small plants. Ultraviolet radiation with wavelength 2500-2600 A has a powerful bacteriocidal effect and has been demonstrated to give bacterial mortality of 99.96 to 99.997 %. A standard plant produced in USA with a capacity of 11.3 m/sup 3//h is illustrated. UV radiation has no effect on the chemical composition of the water and the operating costs are low.

  13. Isolation of a bacteria of the Bacillus genus as indicator in the disinfection of residual waters by means of the ionizing radiation (e{sup -} , {gamma}); Aislamiento de una bacteria del genero Bacillus como indicador en la desinfeccion de aguas residuales mediante la radiacion ionizante (e{sup -} , {gamma})

    Energy Technology Data Exchange (ETDEWEB)

    Mata J, M

    2003-07-01

    The pollutants of the water can be chemical, physical and biological. Among those biological we find to the microorganisms: bacterias, virus and protozoa. These cause important infections in many countries, mainly of Latin America. With the advance of the technology and the quick demographic growth, the biological pollution of the water has already become an important topic since it would damage the public health and it causes that their disinfection has greater attention. In the treatment of residual waters three basic treatments exist the one primary, secondary and tertiary; in this last we find the disinfection, which can be taken to end by chemical and physical methods. For this work of investigation it was used the ionizing radiation, because it is an innovative technology that it eliminates microorganisms in residual waters. The investigation consisted on treating, samples of residual water after the biological treatment of the plant RECICLAGUA with ionizing radiation (electrons and gammas), for the case of electrons it was used the dose of 0.5 kGy and for gamma the dose, of 5 kGy, later the survivor bacteria was isolated to these doses in both cases and they were carried out the tests of identification. In accordance with the obtained results can say that it is about a B. subtilis. The isolated B.subtilis was presented as a pollutant of the flora of the residual water, having a greater survival to the dose of 0.5 and 5 kGy with electrons and gammas, respectively that other present polluting microorganisms in the samples of residual water. For it fits signalize that this microorganism shows characteristics as it easy isolation and identification, the presence with pathogen microorganisms and a greater survival when being irradiated, therefore it can use as indicator in the disinfection of residual waters through ionizing radiation (electrons and gammas). (Author)

  14. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2009-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materals in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs.

  15. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2008-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materals in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs

  16. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2012-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materials in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs.

  17. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2009-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materals in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs

  18. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2013-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materials in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs.

  19. Study of sequential disinfection for the inactivation of protozoa and indicator microorganisms in wastewater

    Directory of Open Access Journals (Sweden)

    Raphael Corrêa Medeiros

    2015-05-01

    Full Text Available Sewage disinfection has the primary objective of inactivating pathogenic organisms to prevent the dissemination of waterborne diseases. This study analyzed individual disinfection, with chlorine and ultraviolet radiation, and sequential disinfection (chlorine-UV radiation. The tests were conducted with anaerobic effluent in batch, in laboratory scale, with two dosages of chlorine (10 and 20 mg L-1 and UV (2.5 and 6.1 Wh m-3. In addition, to guarantee the presence of cysts in the tests, 104 cysts per liter of Giardia spp. were inoculated. The resistance order was as follows: E. coli = Total Coliforms < Clostridium perfringens < Giardia spp.. Furthermore, synergistic effects reached 0.06 to 1.42 log of inactivation in sequential disinfection for both the most resistant microorganisms.

  20. Environmentally friendly disinfectant: Production, disinfectant action and efficiency

    Directory of Open Access Journals (Sweden)

    Čekerevac Milan I.

    2006-01-01

    Full Text Available Silver is a known disinfectant from ancient times, and it has been widely used for various purposes: for food and water disinfection, curing of wounds and as a universal antibiotic for a wide spectrum of diseases - until the Second World War and the discovery of penicillin. Until recently, it was assumed that silver, being a heavy metal, was toxic for humans and living beings. However, the newest research provides facts that the usage of silver, even for drinking water disinfection, is benign if it is added in small concentrations (in parts per billion. It has been shown in the newer scientific and technical literature that silver in colloidal form is a powerful (secondary disinfectant for drinking water, that it can be effectively used for the disinfection of water containers including swimming pools, installations in food industry, medicine, etc. Particularly, it has been shown that colloidal silver combined with hydrogen peroxide shows synergism having strong bactericidal and antiviral effects. The combination can be successfully used as a disinfectant in agriculture, food production and medicine. The original electrochemical process of production, the mechanism of physical-chemical reactions in that process and the mechanism of the antiseptic affect of the environmentally friendly disinfectant, based on the synergism of colloidal silver and hydrogen peroxide and the activity of electrochemically activated water, is shown. The starting solution was anolyte, obtained in electrochemical activation by water electrolysis of a highly diluted solution of K-tartarate in demineralized water (5.5-1CT4 M. The problem of electrolysis of very dilute aqueous solutions in membrane cells was particularly treated. It was shown that the efficiency of the electrolysis depends on the competition between the two processes: the rates of the processes of hydrogen and oxygen generation at the electrodes and the process of diffusion of hydrogen and hydroxyl ions

  1. Irradiation of dates

    International Nuclear Information System (INIS)

    Farkas, J.; Al-Charchafchy, F.; Al-Shaikhaly, M.H.; Mirjan, J.; Auda, H.

    1974-01-01

    Testing of the technical feasibility of radurization of fresh dates was attempted. In addition preliminary studies were carried out to investigate the applicability of gamma rays to date syrup manufacture. The varieties Zahdi, Lelwi and Tabarzel were studied at different stages of ripening. The eating quality of fresh dates was not affected significantly by irradiation even with doses of 270 and 540 krad. The duration of the softening process, after-ripening, of dates was prolonged by low doses of 10-30 krad in the majority of the experimental batches. The time period of after-ripening was reduced with 270 krad, as well as with 540 krad as a result of shortening of the induction period, i.e. the time after which the date begins to soften. The microbial spoilage of khalaal Lelwi dates was considerably reduced by irradiation with doses above 90 krad. The dibis yield of fully rutab dates was highly increased by the radiation doses of 375 to 2000 krad. The darkness and viable cell count of dibis pressed from irradiated dates were significantly lower than that of untreated dates. (F.J.)

  2. Radiation disinfection or disinfestation of nematodes, aphids, mites, thrips, and other pests on food plant materials: evaluation for effectiveness and product quality

    Energy Technology Data Exchange (ETDEWEB)

    Moy, J H; Chinnasri, B; Sipes, B S; Schmitt, D P; Hamasaki, R T; Mersino, E F; Yamakawa, R M [Hawaii Institute of Tropical Agriculture and Human Resources, University of Hawaii at Manoa, Honolulu, HI (United States)

    1999-05-01

    Many fresh herbs, ornamental plants, and several varieties of taro grown in Hawaii are infested with various pests such as aphids, mites, thrips, and nematodes. Finding an efficacious quarantine treatment for these commodities is difficult because most cannot tolerate heat or cold, and a suitable chemical treatment is lacking. Irradiation could be a feasible, practical alternative. Quality of these irradiated materials should be studied to help determine if irradiation is a suitable quarantine treatment. Of the ten fresh herbs irradiated with up to 0.70 kGy, five (rosemary, thyme, oregano, parsley, chives) are very tolerant, and show no difference from the controls after two to three weeks at 7 deg. C. Red ginger and four cultivars of heliconia, very attractive ornamental plants, can be irradiated at 0.75 and 0.50 kGy, respectively, and have a vase life of 10 days or more at 21 deg. C. Leafminer in bean plants cannot emerge when irradiated at 0.15 kGy. The nematode, Meloidogyne javanica, which infects taro and ginger, is prevalent in Hawaii. To cause mortality in second stage juveniles (J2), a gamma-radiation dose higher than 4.0 kGy is necessary. Suppression of hatching of egg masses requires doses of 2.0 kGy and above. Galling of tomato plants inoculated with J2 and egg masses decreases when J2 and egg masses were irradiated at 3.25 kGy and above. Heating J2 at 43 deg. C for 10 min before inoculating them into the plants effectively reduces root galling. Synergism was not found between heat treatment (49 deg. C for 10 or 20 min) and irradiation with up to 0.015 kGy, the dose above which sprouting of ginger rhizomes and taro cormels is inhibited. The results suggest that irradiation is promising as a quarantine treatment for selected fresh herbs and ornamental plants, but not for control of nematodes in root crops. (author) 10 refs, 3 tabs

  3. Radiation disinfection or disinfestation of nematodes, aphids, mites, thrips, and other pests on food plant materials: evaluation for effectiveness and product quality

    International Nuclear Information System (INIS)

    Moy, J.H.; Chinnasri, B.; Sipes, B.S.; Schmitt, D.P.; Hamasaki, R.T.; Mersino, E.F.; Yamakawa, R.M.

    1999-01-01

    Many fresh herbs, ornamental plants, and several varieties of taro grown in Hawaii are infested with various pests such as aphids, mites, thrips, and nematodes. Finding an efficacious quarantine treatment for these commodities is difficult because most cannot tolerate heat or cold, and a suitable chemical treatment is lacking. Irradiation could be a feasible, practical alternative. Quality of these irradiated materials should be studied to help determine if irradiation is a suitable quarantine treatment. Of the ten fresh herbs irradiated with up to 0.70 kGy, five (rosemary, thyme, oregano, parsley, chives) are very tolerant, and show no difference from the controls after two to three weeks at 7 deg. C. Red ginger and four cultivars of heliconia, very attractive ornamental plants, can be irradiated at 0.75 and 0.50 kGy, respectively, and have a vase life of 10 days or more at 21 deg. C. Leafminer in bean plants cannot emerge when irradiated at 0.15 kGy. The nematode, Meloidogyne javanica, which infects taro and ginger, is prevalent in Hawaii. To cause mortality in second stage juveniles (J2), a gamma-radiation dose higher than 4.0 kGy is necessary. Suppression of hatching of egg masses requires doses of 2.0 kGy and above. Galling of tomato plants inoculated with J2 and egg masses decreases when J2 and egg masses were irradiated at 3.25 kGy and above. Heating J2 at 43 deg. C for 10 min before inoculating them into the plants effectively reduces root galling. Synergism was not found between heat treatment (49 deg. C for 10 or 20 min) and irradiation with up to 0.015 kGy, the dose above which sprouting of ginger rhizomes and taro cormels is inhibited. The results suggest that irradiation is promising as a quarantine treatment for selected fresh herbs and ornamental plants, but not for control of nematodes in root crops. (author)

  4. [DESIDENT CaviCide a new disinfectant].

    Science.gov (United States)

    Severa, J; Klaban, V

    2009-01-01

    The properties of the new disinfection agent DESIDENT CaviCide, such as characteristics, disinfection efficiency, biological degradability and ecotoxicity are described. Also areas and forms of usage this biocidal agent are mentioned.

  5. Joint radiation emergency management plan of the international organizations. Emergency preparedness and response. Date effective: 1 December 2002

    International Nuclear Information System (INIS)

    2002-11-01

    directives and regulations that bear on emergency response arrangements among some States. There are also bilateral agreements between some international organizations that also have relevance to preparedness and response arrangements. In March 2002, the IAEA Board of Governors approved a Safety Requirements document to be issued according to the IAEA's statutory function 'to establish ... standards of safety for protection of health and minimization of danger to life and property'. These Safety Requirements, entitled 'Preparedness and Response for a Nuclear or Radiological Emergency' (GS-R-2), are being jointly sponsored by the FAO, IAEA, the International Labour Organisation (ILO), the OECD Nuclear Energy Agency (NEA/OECD), the United Nations Office for the Co-ordination of Humanitarian Affairs (OCHA), the Pan American Health Organization (PAHO) and WHO. These safety standards imply additional expectations with regard to operational emergency response arrangements. It has been recognized by the organizations responsible for emergency response, and reflected in the above requirements, that good planning in advance of an emergency can substantially improve the response. Moreover, one of the most important features of emergency response plans is to have clear lines of responsibility and authority. With this in mind, the IAEA, the organizations party to the Conventions, and some other international organizations that participate in the activities of the IACRNA develop and maintain this 'Joint Radiation Emergency Management Plan of the International Organizations' (the Joint Plan), which describes: the objectives of response; the organizations involved in response, their roles and responsibilities, and the interfaces among them and between them and States; operational concepts; and preparedness arrangements. These practical arrangements are reflected in the various organizations own emergency plans. The IAEA is the main co-ordinating body for development and maintenance of the

  6. Estimating retrospective exposure of household humidifier disinfectants.

    Science.gov (United States)

    Park, D U; Friesen, M C; Roh, H S; Choi, Y Y; Ahn, J J; Lim, H K; Kim, S K; Koh, D H; Jung, H J; Lee, J H; Cheong, H K; Lim, S Y; Leem, J H; Kim, Y H; Paek, D M

    2015-12-01

    We conducted a comprehensive humidifier disinfectant exposure characterization for 374 subjects with lung disease who presumed their disease was related to humidifier disinfectant use (patient group) and for 303 of their family members (family group) for an ongoing epidemiological study. We visited the homes of the registered patients to investigate disinfectant use characteristics. Probability of exposure to disinfectants was determined from the questionnaire and supporting evidence from photographs demonstrating the use of humidifier disinfectant, disinfectant purchase receipts, any residual disinfectant, and the consistency of their statements. Exposure duration was estimated as cumulative disinfectant use hours from the questionnaire. Airborne disinfectant exposure intensity (μg/m(3)) was estimated based on the disinfectant volume (ml) and frequency added to the humidifier per day, disinfectant bulk level (μg/ml), the volume of the room (m(3)) with humidifier disinfectant, and the degree of ventilation. Overall, the distribution patterns of the intensity, duration, and cumulative exposure to humidifier disinfectants for the patient group were higher than those of the family group, especially for pregnant women and patients ≤6 years old. Further study is underway to evaluate the association between the disinfectant exposures estimated here with clinically diagnosed lung disease. Retrospective exposure to household humidifier disinfectant as estimated here can be used to evaluate associations with clinically diagnosed lung disease due to the use of humidifier disinfectant in Korea. The framework, with modifications to account for dispersion and use patterns, can also be potentially adapted to assessment of other household chemical exposures. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Microbiological Efficacy Test Methods of Disinfectants

    OpenAIRE

    Şahiner, Aslı

    2015-01-01

    Disinfection process is required in every area where microbiological contamination and infection risk is present, especially in medical sector, food, veterinary and general common living areas hence many disinfectants and antiseptics are being produced for different purposes. Disinfectants are made up a large group of biocidal products. Depending on the chemical properties of active substances, targeted microorganisms may differ While some disinfectants are effective in a large spectrum, othe...

  8. UV disinfection in drinking water supplies.

    Science.gov (United States)

    Hoyer, O

    2000-01-01

    UV disinfection has become a practical and safely validatable disinfection procedure by specifying the requirements for testing and monitoring in DVGW standard W 294. A standardized biodosimetric testing procedure and monitoring with standardized UV sensors is introduced and successfully applied. On-line monitoring of irradiance can be counterchecked with handheld reference sensors and makes it possible that UV systems can be used for drinking water disinfection with the same level of confidence and safety as is conventional chemical disinfection.

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

    Science.gov (United States)

    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. Published by Elsevier Inc.

  10. Microwave discharge electrodeless lamps (MDEL). V. Microwave-assisted photolytic disinfection of Bacillus subtilis in simulated electroplating wash wastewaters.

    Science.gov (United States)

    Horikoshi, Satoshi; Tsuchida, Akihiro; Abe, Masahiko; Ohba, Naoki; Uchida, Masayoshi; Serpone, Nick

    2010-01-01

    This short article examines the microwave-assisted photolytic disinfection of aqueous solutions contaminated by Bacillus subtilis microorganisms using UV and vacuum-UV radiation emitted from a microwave discharge electrodeless lamp (MDEL), a device containing a Hg/Ar gas-fill that was proposed recently for use in Advanced Oxidation Processes (AOPs). Results of the disinfection are compared with those obtained from UV radiation emitted by a low-pressure electrode Hg lamp and by an excimer lamp. Also examined is the disinfection of B. subtilis aqueous media that contained Au3+ or Ni2+ ions, species often found in the treatment of electroplating wash wastewaters.

  11. Cross-Resistance of UV- or Chlorine Dioxide-Resistant Echovirus 11 to Other Disinfectants

    Directory of Open Access Journals (Sweden)

    Qingxia Zhong

    2017-10-01

    Full Text Available The emergence of waterborne viruses with resistance to disinfection has been demonstrated in the laboratory and in the environment. Yet, the implications of such resistance for virus control remain obscure. In this study we investigate if viruses with resistance to a given disinfection method exhibit cross-resistance to other disinfectants. Chlorine dioxide (ClO2- or UV-resistant populations of echovirus 11 were exposed to five inactivating treatments (free chlorine, ClO2, UV radiation, sunlight, and heat, and the extent of cross-resistance was determined. The ClO2-resistant population exhibited cross-resistance to free chlorine, but to none of the other inactivating treatments tested. We furthermore demonstrated that ClO2 and free chlorine act by a similar mechanism, in that they mainly inhibit the binding of echovirus 11 to its host cell. As such, viruses with host binding mechanisms that can withstand ClO2 treatment were also better able to withstand oxidation by free chlorine. Conversely, the UV-resistant population was not significantly cross-resistant to any other disinfection treatment. Overall, our results indicate that viruses with resistance to multiple disinfectants exist, but that they can be controlled by inactivating methods that operate by a distinctly different mechanism. We therefore suggest to utilize two disinfection barriers that act by different mechanisms in order to control disinfection-resistant viruses.

  12. Radiometric dating

    International Nuclear Information System (INIS)

    Das, N.R.

    2017-01-01

    Since the discovery of natural radioactivity in uranium, in the last decade of the nineteenth century, the nuclear property of radioactive decay of radionuclides at immutable rates has been effectively utilized in dating of varieties of naturally occurring geological matrices and the organisms which constantly replenish their "1"4C supply through respiration when alive on earth. During the period, applications of radiometric dating techniques have been extensively diversified and have enabled the geologists to indicate the absolute time scales of geological formations and the evolution of the solar system, the earth, meteorites, lunar rocks, etc. and the archaeologists to record the facts of history of several important events like dinosaur era, Iceman, the Shroud in Turin and many other ancient artefacts. In the development of dating methods, varieties of naturally occurring radio-isotopic systems with favorable half-lives ranging from about 10 years to over 100 billion years have been used as radiometric clocks. (author)

  13. Crop maize evapotranspiration; 2: ratios between the evapotranspiration to class A pan evaporation, to the reference evapotranspiration and to global solar radiation, at three sowing dates

    International Nuclear Information System (INIS)

    Matzenauer, R.; Bergamashi, H.; Berlato, M.A.

    1998-01-01

    Water availability is the most limiting factor for growth and grain yield of maize in the State of Rio Grande do Sul, Brazil, reducing frequently this production. Therefore, studies involving the determination of the water requirements are important for irrigation management to minimize the water availability problem. The main objective of this study was to calculate ratios between the maize crop evapotranspiration (ETm) to the class A pan evaporation (Eo), to the reference evapotranspiration (ETo) and to global solar radiation (Rs), in order to obtain ralations between ETm/Eo, ETm/ETo and ETm/Rs, at different crop stages for three different sowing dates. Field experiments were carried out at the Experimental Station of Taquari/RS, 29°48’ of south latitude, 51°49’of west longitude, and 76m of altitude, from 1976/77 to 1988/89. ETm was measured using drainage lysimeters (Thornthwaite-Mather type). The average ratio between ETm and Eo for whole crop cycle (from sowing to physiological maturity) was 0.66, 0.72, and 0.68, respectively, in crops sown on September, October, and November. The average ratio between ETm and ETo for whole crop cycle was 0.74, 0.81, and 0.8, in crops sown on September, October, and November, while the average ratio between ETm and Rs was 0.45, 0.51, and 0.49 for the same sowing dates. The higher average values of crop coefficients occured from tasseling to the milk grain stage, when ETm/Eo was 0.81, 0.92, and 0.81; ETm/ETo was 0.97, 1.05, and 0.96, whereas ETm/Rs was 0.6, 0.68, and 0.6 for crops sown on September, October, and November, respectively [pt

  14. Radiation disinfection of rice-straw products

    International Nuclear Information System (INIS)

    Ito, Hitoshi; Ishigaki, Isao; Ohki, Yumi.

    1991-01-01

    For the quarantine treatment of rice-straw products from foreign countries, irradiation effects of gamma-rays and electron beams on plant pathogenic microorganisms especially on fungi were investigated. The total aerobic bacteria in rice-straw was determined to be 3x10 7 - 3x10 8 per gram which consisted mainly of Pseudomonas, Flavobacterium, Arthrobacter and Erwinia. The principal bacteria in rice-straw could be eliminated with 5 kGy of gamma irradiation. Deinococcus proteolyticus and Pseudomonas radiora were the main survivors at 5 to 12 kGy of irradiation. Saprophytic fungus which belongs to Dimorphospora also survived up to 8 kGy of irradiation. The D 10 values of 26 strains of fungi isolated from rice-straw were 1.1 to 2.5 times higher in the dry condition compared to the values when irradiated in 0.067 M phosphate buffer solution. The induction dose in the dry condition also increased from 1.5 to 10 times than that in the wet condition. In the case of electron beam irradiation of fungi under dry conditions, D 10 values were about 1.3 times higher than that of gamma irradiation. From this study, the dose necessary to reduce the plant pathogenic fungi in rice-straw at a level below 10 -4 per gram was estimated to be as 7-8 kGy for gamma-irradiation and 10 kGy for electron beam irradiation. (author)

  15. Radiation disinfection of rice-straw products

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hitoshi; Ishigaki, Isao (Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment); Ohki, Yumi

    1991-11-01

    For the quarantine treatment of rice-straw products from foreign countries, irradiation effects of gamma-rays and electron beams on plant pathogenic microorganisms especially on fungi were investigated. The total aerobic bacteria in rice-straw was determined to be 3x10{sup 7} - 3x10{sup 8} per gram which consisted mainly of Pseudomonas, Flavobacterium, Arthrobacter and Erwinia. The principal bacteria in rice-straw could be eliminated with 5 kGy of gamma irradiation. Deinococcus proteolyticus and Pseudomonas radiora were the main survivors at 5 to 12 kGy of irradiation. Saprophytic fungus which belongs to Dimorphospora also survived up to 8 kGy of irradiation. The D{sub 10} values of 26 strains of fungi isolated from rice-straw were 1.1 to 2.5 times higher in the dry condition compared to the values when irradiated in 0.067 M phosphate buffer solution. The induction dose in the dry condition also increased from 1.5 to 10 times than that in the wet condition. In the case of electron beam irradiation of fungi under dry conditions, D{sub 10} values were about 1.3 times higher than that of gamma irradiation. From this study, the dose necessary to reduce the plant pathogenic fungi in rice-straw at a level below 10{sup -4} per gram was estimated to be as 7-8 kGy for gamma-irradiation and 10 kGy for electron beam irradiation. (author).

  16. Disinfection of sewage sludge with gamma radiation

    International Nuclear Information System (INIS)

    1980-01-01

    In the Geiselbullach sewage treatment plant near Munich, sewage irradiation by a 60 Co source is being investigated on a technical scale. 145 m 3 of sewage sludge are irradiated per day and then used as field fertilizer. (orig./HBR) [de

  17. Luminescence dating in archaeology

    International Nuclear Information System (INIS)

    Wintle, A.G.

    2001-01-01

    Thermoluminescence (TL) dating is routinely applied to burnt lithic material. Simple fires are capable of enabling stones weighing a few hundred grams to reach 450 o C, thus zeroing the TL signal. TL dates have been obtained for Upper and Lower Paleolithic sites in Europe and the Near East. TL dating continues to be used for dating pottery and for authentification of ceramic works of art. Some recent studies report the use of optically stimulated luminescence (OSL) (also know as photoluminescence) for dating very small samples of quartz, e.g. from small pieces of pottery or frm metallurgical slag The major recent advance has been in the development of a reliable laboratory procedure for using the OSL signal from quartz to obtain the past radiation exposure. The quartz OSL signal is extremely sensitive to light and is reduced to a negligible level on exposure to direct sunlight for radionuclides during burial, signal to date san.sized quartz grains extracted from sediments, The OSL signal is stimulated by 470 nm light from emitting diodes and the detected using flirters centred on 340 nm A similar signal can be obtained from feldspar grain when are exposed to infrared wavelengths around 880 nm. The infrared stimulated luminescence (IRSL) signals is also rapidly depleted by exposure to sunlight, and dating of colluvial deposits from archaeological sites has been reported

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

    Energy Technology Data Exchange (ETDEWEB)

    Lee, O-Mi [Quarantine Technology Center, Animal and Plant Quarantine Agency Plant, 175 Anyangro, Manan-Gu, Anyang-Si, Gyeonggi-Do 480-757 (Korea, Republic of); Kim, Hyun Young; Park, Wooshin; Kim, Tae-Hun [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup, Jeonbuk 580-185 (Korea, Republic of); Yu, Seungho, E-mail: seunghoyu68@gmail.com [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup, Jeonbuk 580-185 (Korea, Republic of)

    2015-09-15

    Highlights: • The ionizing radiation was applied to inactivate microorganisms and the critical dose to prevent the regrowth was determined. • The seasonal variation of disinfection efficiency observed in on-site UV treatment system was influenced by suspended solid, temperature, and precipitation, whereas, stable values were observed in ionizing radiation. • The electrical power consumption for disinfection using UV and ozone requires higher energy than ionizing radiation. - Abstract: 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.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

    Highlights: • The ionizing radiation was applied to inactivate microorganisms and the critical dose to prevent the regrowth was determined. • The seasonal variation of disinfection efficiency observed in on-site UV treatment system was influenced by suspended solid, temperature, and precipitation, whereas, stable values were observed in ionizing radiation. • The electrical power consumption for disinfection using UV and ozone requires higher energy than ionizing radiation. - Abstract: 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

  20. Radiocarbon dating

    International Nuclear Information System (INIS)

    Lazos R, L.

    2005-01-01

    The application of the radiocarbon dating in archaeology has not served only to solve problems related with the establishment of chronologies, but also in the development of archaeological methods of excavation and interpretation. This has been possible because the dating method by radiocarbon provides a common temporary scale that transcends the cultural and regional frontiers. It is even spoken of the revolution that has meant the fact that the application of this method has allowed to the archaeologist to pass from the construction of chronologies until the evaluation and dynamic interpretation of the archaeological data to build theories. This work explains and compares methods for the detection of 14 C, as the gas counting, the liquid scintillation counting and the mass spectrometry with accelerators. (Author)

  1. The project of the technological line of the electronic-beam drains disinfection in the infected hospitals' divisions and tubercular centres

    International Nuclear Information System (INIS)

    Shlapatska, V.V.; Volkonsky, V.G.; Sakhno, V.I.; Tomchaj, S.P.

    1999-01-01

    The purpose of the project was to create the electrophysical facility for the environmental protection from contamination by drains of the infected hospitals' divisions and tubercular centres and prevention of open water reservoirs. Development of the economically approved methods of the radiative disinfection of contaminated drains; development of the inexpensive compact facility for the electron-beam disinfection of small volume drains

  2. Improving stethoscope disinfection at a children's hospital.

    Science.gov (United States)

    Zaghi, Justin; Zhou, Jing; Graham, Dionne A; Potter-Bynoe, Gail; Sandora, Thomas J

    2013-11-01

    Stethoscopes are contaminated with pathogenic bacteria and pose a risk for transmission of infections, but few clinicians disinfect their stethoscope after every use. We sought to improve stethoscope disinfection rates among pediatric healthcare providers by providing access to disinfection materials and visual reminders to disinfect stethoscopes. Prospective intervention study. Inpatient units and emergency department of a major pediatric hospital. Physicians and nurses with high anticipated stethoscope use. Baskets filled with alcohol prep pads and a sticker reminding providers to regularly disinfect stethoscopes were installed outside of patient rooms. Healthcare providers' stethoscope disinfection behaviors were directly observed before and after the intervention. Multivariable logistic regression models were created to identify independent predictors of stethoscope disinfection. Two hundred twenty-six observations were made in the preintervention period and 261 in the postintervention period (83% were of physicians). Stethoscope disinfection compliance increased significantly from a baseline of 34% to 59% postintervention (P stethoscope disinfection supplies and visible reminders outside of patient rooms significantly increased stethoscope disinfection rates among physicians and nurses at a children's hospital. This simple intervention could be replicated at other healthcare facilities. Future research should assess the impact on patient infections.

  3. Thermoluminescence dating of pottery

    International Nuclear Information System (INIS)

    Higashimura, Takenobu; Ichikawa, Yoneta.

    1978-01-01

    This report is divided into two parts. The first half describes on the history of thermoluminescence dating, and the latter half, the principle and measurement examples. It was in late 1955 that the measurement of radiation dose using thermoluminescence began. The method to thermoluminescence dating was developed when it was found that most natural stones emit the thermoluminescence. About Greek earthen wares, the study of which was presented in 1961 by G. Kennedy of University of California, the dating was able to be made within the standard deviation of 10%. Since then, this dating method progressed rapidly, and a number of laboratories are now forwarding the investigation. In the samples of natural materials, intensity of thermoluminescence I is proportional to natural radiation dose D which has been absorbed by the samples, i.e. I = kD, where k is the susceptibility of thermoluminescence of the samples. Since k is different in each sample, D can be determined by irradiating the sample with β or γ ray of known dose D 0 , measuring its luminescence I 0 , and eliminating k through these two equations, because i 0 = kD 0 . Next, if t is assumed to be the time passed since a pottery was made, D is expressed as Rt, where R is the natural radiation dose per year absorbed by the pottery. Thus t is determined if R is known. The report describes on the method of measuring R. As an example, the results of measurement of the potteries excavated at Iwakura remains, Yorikura, Taishaku-kyo, are listed. Results by 14 C dating are also described for reference. (Wakatsuki, Y.)

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

    Science.gov (United States)

    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 ...

  5. History of radiocarbon dating

    Energy Technology Data Exchange (ETDEWEB)

    Libby, W F [Department of Chemistry and Institute of Geophysics, University of California, Los Angeles, CA (United States)

    1967-08-15

    The development is traced of radiocarbon dating from its birth in curiosity regarding the effects of cosmic radiation on Earth. Discussed in historical perspective are: the significance of the initial measurements in determining the course of developments; the advent of the low-level counting technique; attempts to avoid low-level counting by the use of isotopic enrichment; the gradual appearance of the environmental effect due to the combustion of fossil fuel (Suess effect); recognition of the atmosphere ocean barrier for carbon dioxide exchange; detailed understanding of the mixing mechanism from the study of fallout radiocarbon; determination of the new half-life; indexing and the assimilation problem for the massive accumulation of dates; and the proliferation of measurement techniques and the impact of archaeological insight on the validity of radiocarbon dates. (author)

  6. Zinc oxide nanoparticles for water disinfection

    Directory of Open Access Journals (Sweden)

    Emelita Asuncion S. Dimapilis

    2018-03-01

    Full Text Available The world faces a growing challenge for adequate clean water due to threats coming from increasing demand and decreasing supply. Although there are existing technologies for water disinfection, their limitations, particularly the formation of disinfection-by-products, have led to researches on alternative methods. Zinc oxide, an essential chemical in the rubber and pharmaceutical industries, has attracted interest as antimicrobial agent. In nanoscale, zinc oxide has shown antimicrobial properties which make its potential great for various applications. This review discusses the synthesis of zinc oxide with focus on precipitation method, its antimicrobial property and the factors affecting it, disinfection mechanisms, and the potential application to water disinfection.

  7. Designing plasmas for chronic wound disinfection

    International Nuclear Information System (INIS)

    Nosenko, T; Shimizu, T; Morfill, G E

    2009-01-01

    Irradiation with low-temperature atmospheric-pressure plasma provides a promising method for chronic wound disinfection. To be efficient for this purpose, plasma should meet the following criteria: it should significantly reduce bacterial density in the wounded area, cause a long-term post-irradiation inhibition of bacterial growth, yet without causing any negative effect on human cells. In order to design plasmas that would satisfy these requirements, we assessed the relative contribution of different components with respect to bactericidal properties due to irradiation with argon plasma. We demonstrate that plasma-generated UV radiation is the main short-term sterilizing factor of argon plasma. On the other hand, plasma-generated reactive nitrogen species (RNS) and reactive oxygen species (ROS) cause a long-term 'after-irradiation' inhibition of bacterial growth and, therefore, are important for preventing wound recolonization with bacteria between two treatments. We also demonstrate that at certain concentrations plasma-generated RNS and ROS cause significant reduction of bacterial density, but have no adverse effect on human skin cells. Possible mechanisms of the different effects of plasma-generated reactive species on bacteria and human cells are discussed. The results of this study suggest that argon plasma for therapeutic purposes should be optimized in the direction of reducing the intensity of plasma-generated UV radiation and increasing the density of non-UV plasma products.

  8. Designing plasmas for chronic wound disinfection

    Energy Technology Data Exchange (ETDEWEB)

    Nosenko, T; Shimizu, T; Morfill, G E [Max-Planck Institute for Extraterrestrial Physics, Garching (Germany)], E-mail: tnosenko@mpe.mpg.de

    2009-11-15

    Irradiation with low-temperature atmospheric-pressure plasma provides a promising method for chronic wound disinfection. To be efficient for this purpose, plasma should meet the following criteria: it should significantly reduce bacterial density in the wounded area, cause a long-term post-irradiation inhibition of bacterial growth, yet without causing any negative effect on human cells. In order to design plasmas that would satisfy these requirements, we assessed the relative contribution of different components with respect to bactericidal properties due to irradiation with argon plasma. We demonstrate that plasma-generated UV radiation is the main short-term sterilizing factor of argon plasma. On the other hand, plasma-generated reactive nitrogen species (RNS) and reactive oxygen species (ROS) cause a long-term 'after-irradiation' inhibition of bacterial growth and, therefore, are important for preventing wound recolonization with bacteria between two treatments. We also demonstrate that at certain concentrations plasma-generated RNS and ROS cause significant reduction of bacterial density, but have no adverse effect on human skin cells. Possible mechanisms of the different effects of plasma-generated reactive species on bacteria and human cells are discussed. The results of this study suggest that argon plasma for therapeutic purposes should be optimized in the direction of reducing the intensity of plasma-generated UV radiation and increasing the density of non-UV plasma products.

  9. Comparison of Riboflavin and Toluidine Blue O as Photosensitizers for Photoactivated Disinfection on Endodontic and Periodontal Pathogens In Vitro.

    Science.gov (United States)

    Nielsen, Henrik Krarup; Garcia, Javier; Væth, Michael; Schlafer, Sebastian

    2015-01-01

    Photoactivated disinfection has a strong local antimicrobial effect. In the field of dentistry it is an emerging adjunct to mechanical debridement during endodontic and periodontal treatment. In the present study, we investigate the effect of photoactivated disinfection using riboflavin as a photosensitizer and blue LED light for activation, and compare it to photoactivated disinfection with the widely used combination of toluidine blue O and red light. Riboflavin is highly biocompatible and can be activated with LED lamps at hand in the dental office. To date, no reports are available on the antimicrobial effect of photoactivated disinfection using riboflavin/blue light on oral microorganisms. Planktonic cultures of eight organisms frequently isolated from periodontal and/or endodontic lesions (Aggregatibacter actinomycetemcomitans, Candida albicans, Enterococcus faecalis, Escherischia coli, Lactobacillus paracasei, Porphyromonas gingivalis, Prevotella intermedia and Propionibacterium acnes) were subjected to photoactivated disinfection with riboflavin/blue light and toluidine blue O/red light, and survival rates were determined by CFU counts. Within the limited irradiation time of one minute, photoactivated disinfection with riboflavin/blue light only resulted in minor reductions in CFU counts, whereas full kills were achieved for all organisms when using toluidine blue O/red light. The black pigmented anaerobes P. gingivalis and P. intermedia were eradicated completely by riboflavin/blue light, but also by blue light treatment alone, suggesting that endogenous chromophores acted as photosensitizers in these bacteria. On the basis of our results, riboflavin cannot be recommended as a photosensitizer used for photoactivated disinfection of periodontal or endodontic infections.

  10. Wastewater disinfection by combination of ultrasound and ultraviolet irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Naddeo, V., E-mail: vnaddeo@unisa.it [Department of Civil Engineering, University of Salerno, Via Ponte don Melillo, 1, 84084 Fisciano (Italy); Landi, M.; Belgiorno, V. [Department of Civil Engineering, University of Salerno, Via Ponte don Melillo, 1, 84084 Fisciano (Italy); Napoli, R.M.A. [Department of Environmental Science, University of Napoli Parthenope, Via Amm. F. Acton, 38, 80133 Napoli (Italy)

    2009-09-15

    Reclamation and reuse of wastewater is one of the most effective ways to alleviate water resource scarcity. In many countries very stringent limit for chlorination by-products such as trihalomethanes has been set for wastewater reuse. Accordingly, the use of alternative oxidation/disinfection systems should be evaluated as possible alternative to chlorine. Recently ultrasound (US) was found to be effective as pre-treatment for wastewater disinfection by UV irradiation. The aim of this work is to investigate the wastewater advanced treatment by simultaneous combination of UV and US in terms of bacteria inactivation (Total coliform and Escherichia coli) at pilot-scale. The pilot plant was composed of two reactors: US-UV reactor and UV reactor. The influence of different reaction times, respective US and UV dose and synergistic effect was tested and discussed for two different kinds of municipal wastewater. An important enhancement of UV disinfection ability has been observed in presence of US, especially with wastewater characterized by low transmittance. In particular the inactivation was greater for T. coliform than for E. coli. Furthermore, the results obtained showed also that the fouling formation on the lamps was slower in US-UV reactor than in UV reactor both with and without solar radiation.

  11. Wastewater disinfection by combination of ultrasound and ultraviolet irradiation

    International Nuclear Information System (INIS)

    Naddeo, V.; Landi, M.; Belgiorno, V.; Napoli, R.M.A.

    2009-01-01

    Reclamation and reuse of wastewater is one of the most effective ways to alleviate water resource scarcity. In many countries very stringent limit for chlorination by-products such as trihalomethanes has been set for wastewater reuse. Accordingly, the use of alternative oxidation/disinfection systems should be evaluated as possible alternative to chlorine. Recently ultrasound (US) was found to be effective as pre-treatment for wastewater disinfection by UV irradiation. The aim of this work is to investigate the wastewater advanced treatment by simultaneous combination of UV and US in terms of bacteria inactivation (Total coliform and Escherichia coli) at pilot-scale. The pilot plant was composed of two reactors: US-UV reactor and UV reactor. The influence of different reaction times, respective US and UV dose and synergistic effect was tested and discussed for two different kinds of municipal wastewater. An important enhancement of UV disinfection ability has been observed in presence of US, especially with wastewater characterized by low transmittance. In particular the inactivation was greater for T. coliform than for E. coli. Furthermore, the results obtained showed also that the fouling formation on the lamps was slower in US-UV reactor than in UV reactor both with and without solar radiation.

  12. Radiation

    International Nuclear Information System (INIS)

    2013-01-01

    The chapter one presents the composition of matter and atomic theory; matter structure; transitions; origin of radiation; radioactivity; nuclear radiation; interactions in decay processes; radiation produced by the interaction of radiation with matter

  13. Sediment dating in review

    International Nuclear Information System (INIS)

    Prescott, J.R.; Robertson, G.B.

    1997-01-01

    The paper will comment on a few issues of particular relevance to Australasia. Thermoluminescent (TL) methods applied to open sites have been demonstrated to be effective. A particularly good example of this is to be found in the South East of South Australia, where a sequence of low ranges runs roughly parallel with the coast. They represent relict sand dunes left behind, on a slowly rising land surface by successive interglacial incursions of the sea at roughly 120 ka intervals. Comparison with ages established on independent geological grounds allows a test of quartz TL and IRSL ages that is believable back to 500 ka. Older than this, we do not yet understand the physics of the quartz well enough to go unequivocally forward (backward?). Similar results are emerging elsewhere. With dating limits being pushed ever further back, the time variation of the environmental radiation giving rise to the stored luminescent energy needs to be addressed. Particularly at wet sites, radioactive disequilibrium must be considered. In any case, a time profile of the radiation dose rate needs to be determined.In dating a given site or sites the value of ages obtained by any dating method,including C-14, is enhanced by parallel measurements with an different method

  14. Anaerobic effluent disinfection using ozone: Byproducts formation

    NARCIS (Netherlands)

    Silva, G.H.R.; Daniel, L.A.; Bruning, H.; Rulkens, W.H.

    2010-01-01

    This research was aimed at studying oxidation processes, coliform inactivation effectiveness and disinfection byproducts (DBPs) associated with the disinfection of anaerobic sanitary wastewater effluent with ozone applied at doses of 5.0, 8.0 and 10.0mg O(3)L(-1) for contact times of 5, 10 and 15

  15. Ultraviolet (UV) Disinfection for Drinking Water Systems

    Science.gov (United States)

    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...

  16. Silver disinfection in water distribution systems

    Science.gov (United States)

    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.

  17. Chemical disinfection of combined sewer overflows

    DEFF Research Database (Denmark)

    Chhetri, Ravi Kumar

    of the residual disinfectants PFA, PAA and chlorine dioxide (ClO2), and their degradation products hydrogen peroxide and chlorite, in relation to organisms in the aquatic ecosystem was studied. With the help of ecotoxicity data, a preliminary environmental risk assessment of PFA, PAA and ClO2 for CSO disinfection...

  18. Adaptive Mechanisms Underlying Microbial Resistance to Disinfectants

    Science.gov (United States)

    2016-02-01

    11775]). E.coli is a gram-negative, facultative anaerobic, and rod-shaped bacteria commonly found in warm-blooded animals . 2.1.2 Disinfectants...Nisbet, D.J. Disinfectant and Antibiotic Susceptibility Profiles of Escherichia coli O157:H7 Strains from Cattle Carcasses , Feces, and Hides and

  19. Adverse health effects of humidifier disinfectants in Korea: lung toxicity of polyhexamethylene guanidine phosphate.

    Science.gov (United States)

    Kim, Ha-Ryong; Hwang, Gi-Wook; Naganuma, Akira; Chung, Kyu-Hyuck

    2016-01-01

    Exposure to humidifier disinfectants was identified in 2011 as the potential cause of an outbreak of lung disease in Korea. It is estimated that over 8 million people have been exposed to humidifier disinfectants-chemicals added to the water used in humidifiers to prevent the growth of microorganisms-since their commercial introduction. The primary component of humidifier disinfectant products involved was polyhexamethylene guanidine phosphate (PHMG-P), a guanidine-based antimicrobial agent. Lesions observed in the lungs of patients were similar to those observed in laboratory animals exposed to PHMG-P. In this review, we outline the physicochemical and toxicological properties of PHMG-P, and introduce a putative mechanism for its lung toxicity based in large part on research findings to date.

  20. Thermoluminescence dating method

    International Nuclear Information System (INIS)

    Zink, A.

    2004-01-01

    A crystal that is submitted to radiation stores energy and releases this energy under the form of light whenever it is heated. These 2 properties: the ability to store energy and the ability to reset the energy stored are the pillars on which time dating methods like thermoluminescence are based. A typical accuracy of the thermoluminescence method is between 5 to 7% but an accuracy of 3% can be reached with a sufficient number of measurement. This article describes the application of thermoluminescence to the dating of a series of old terra-cotta statues. This time measurement is absolute and does not require any calibration, it represents the time elapsed since the last heating of the artifact. (A.C.)

  1. Cleaning and Disinfection of Bacillus cereus Biofilm.

    Science.gov (United States)

    Deal, Amanda; Klein, Dan; Lopolito, Paul; Schwarz, John Spencer

    2016-01-01

    Methodology has been evolving for the testing of disinfectants against bacterial single-species biofilms, as the difficulty of biofilm remediation continues to gain much-needed attention. Bacterial single-species biofilm contamination presents a real risk to good manufacturing practice-regulated industries. However, mixed-species biofilms and biofilms containing bacterial spores remain an even greater challenge for cleaning and disinfection. Among spore-forming microorganisms frequently encountered in pharmaceutical manufacturing areas, the spores of Bacillus cereus are often determined to be the hardest to disinfect and eradicate. One of the reasons for the low degree of susceptibility to disinfection is the ability of these spores to be encapsulated within an exopolysachharide biofilm matrix. In this series of experiments, we evaluated the disinfectant susceptibility of B. cereus biofilms relative to disassociated B. cereus spores and biofilm from a non-spore-forming species. Further, we assessed the impact that pre-cleaning has on increasing that susceptibility. Methodology has been evolving for the testing of disinfectants against bacterial single-species biofilms, as the difficulty of biofilm remediation continues to gain much-needed attention. Bacterial single-species biofilm contamination presents a real risk to good manufacturing practice-regulated industries. However, mixed-species biofilms and biofilms containing bacterial spores remain an even greater challenge for cleaning and disinfection. Among spore-forming microorganisms frequently encountered in pharmaceutical manufacturing areas, the spores of Bacillus cereus are often determined to be the hardest to disinfect and eradicate. One of the reasons for the low degree of susceptibility to disinfection is the ability of these spores to be encapsulated within an exopolysachharide biofilm matrix. In this series of experiments, we evaluated the disinfectant susceptibility of B. cereus biofilms relative to

  2. How clean is your scope? A completed audit cycle of the disinfection of nasendoscopes

    Science.gov (United States)

    Lakhani, Raj; Smithard, Abigail; Bleach, Nigel

    2010-01-01

    INTRODUCTION Correct disinfection of nasendoscopes is essential to address both the potential iatrogenic transmission of infection and to avoid injury from the chemicals used. MATERIALS AND METHODS Standards-based audit of the disinfection of nasendoscopes against the ENT UK guidelines, ervention: instructional poster and staff training session. The disinfection process was re-audited one month later. RESULTS A total of 10 sessions and 31 cleaning episodes were audited in the first cycle (C1). A total of 12 sessions and 36 cleaning episodes were re-audited in the second cycle (C2). Clinic set-up results: there was a marked improvement in the checking of the expiry date (C1 = 5/10; C2 = 10/12; P ≤ 0.001) and recording the date for the solution to be discarded (C1 = 0/10; C2 = 10/12; P ≤ 0.048). Each cleaning episode results: an improvement in transportation in a ‘dirty bag’ (C1 = 0/31; C2 = 19/36; P ≤ 0.001), washing of the scope (C1 = 0/31; C2 = 36/36; P ≤ 0.001), adequate disinfection time (C1 = 16/31; C2 = 33/36; P≤ 0.001), rinsing and drying with alcohol swab (C1 = 0/31; C2 = 35/36; P ≤ 0.001) and placing of the scope in a ‘clean bag’ for storage (C1 = 0/31; C2 = 35/36; P ≤ 0.001) was seen after the intervention. CONCLUSIONS The introduction of a poster and training in the disinfection of nasendoscopes proved successful in improving compliance with the published guidelines. These simple measures were simple, cheap and effective to institute. The benefit of improving the disinfection of nasendoscopes to patients, doctors and the organisations that they work in is clear. PMID:20883605

  3. Use of ultraviolet-disinfected nutrient solutions in greenhouses

    International Nuclear Information System (INIS)

    Acher, A.; Heuer, B.; Rubinskaya, E.; Fischer, E.

    1997-01-01

    Environmental concerns and economics require the recycling of plant nutrient solutions (PNS) used in soilless cultures in greenhouses. To avoid possible outbreaks of plant diseases, disinfection of the recycled PNS might be necessary. This paper describes a case study on the stability of Fe 3+ -chelates, present in PNS and exposed to ultraviolet radiation (UV 254 nm) for disinfection, and the effect on plant growth. Three Fe-chelates, each containing 2 mg Fe 3+ l -1 , in PNS were: i, Fe-EDDHA (Fe-ethylene-diamine-dihydroxyphenyl acetic acid); ii, Fe-Na-EDTA (Fe-ethylene-diamine-tetraacetic acid); and iii, Fe-DTPA (Fe-diethylene-triamine-pentaacetic acid). Seedlings of sorghum, corn and tomatoes were grown hydroponically for four weeks in continuously aerated PNS, which had been exposed previously for 0, 2.5 and 130 s to a UV radiation fluence of 80 mW s -1 cm -2 . The accumulation of plant fresh weight (APFW) differed from non-treated controls, depending on chelating agent and on exposure time to UV. The greatest APFW was observed in sorghum (128, 178 and 98%) at 2.5 s UV-exposure for PNS containing i, ii and iii, respectively. For corn and tomato, the respective results were: 108, 139 and 96%, and 129, 91 and 89% for tomatoes, respectively. The stability of i, ii and iii upon exposure to UV radiation is discussed. (author)

  4. 9 CFR 166.14 - Cleaning and disinfecting.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Cleaning and disinfecting. 166.14... AGRICULTURE SWINE HEALTH PROTECTION SWINE HEALTH PROTECTION General Provisions § 166.14 Cleaning and disinfecting. (a) Disinfectants to be used. Disinfection required under the regulations in this Part shall be...

  5. 9 CFR 83.7 - Shipping containers; cleaning and disinfection.

    Science.gov (United States)

    2010-01-01

    ... HEMORRHAGIC SEPTICEMIA § 83.7 Shipping containers; cleaning and disinfection. (a) All live fish that are to be... been cleaned and disinfected. (1) Cleaning and disinfection of shipping containers must be monitored by... who issues the ICI. (2) Cleaning and disinfection must be sufficient to neutralize any VHS virus to...

  6. Disinfection and physical and chemical changes in waste waters, sludge and agricultural wastes

    International Nuclear Information System (INIS)

    Groneman, A.F.; Oosterheert, W.F.

    1980-01-01

    It is of interest for agriculture to consider recycling scenarios that use undigested sludges as they contain higher concentrations of nitrogen, phosphorus and organic matter than digested sludges. Also from the point of view of waste water management, this approach is of interest because it reduces the time and number of treatments of sludges, thus resulting in technological and economic advantages. However, the utilization of this type of sludge in agriculture is restricted by the presence of human pathogens. Therefore studies concerning the disinfection efficiency of gamma irradiation in undigested sludge at pilot plant level were performed and results compared with the disinfection efficiency of this radiation treatment in digested sludge. (Auth.)

  7. Surface Disinfections: Present and Future

    Directory of Open Access Journals (Sweden)

    Matteo Saccucci

    2018-01-01

    Full Text Available The propagation of antibiotic resistance increases the chances of major infections for patients during hospitalization and the spread of health related diseases. Therefore finding new and effective solutions to prevent the proliferation of pathogenic microorganisms is critical, in order to protect hospital environment, such as the surfaces of biomedical devices. Modern nanotechnology has proven to be an effective countermeasure to tackle the threat of infections. On this note, recent scientific breakthroughs have demonstrated that antimicrobial nanomaterials are effective in preventing pathogens from developing resistance. Despite the ability to destroy a great deal of bacteria and control the outbreak of infections, nanomaterials present many other advantages. Moreover, it is unlikely for nanomaterials to develop resistance due to their multiple and simultaneous bactericidal mechanisms. In recent years, science has explored more complex antimicrobial coatings and nanomaterials based on graphene have shown great potential in antibacterial treatment. The purpose of this article is to deepen the discussion on the threat of infections related to surface disinfection and to assess the state of the art and potential solutions, with specific focus on disinfection procedures using nanomaterials.

  8. Sonochemical disinfection of municipal wastewater

    International Nuclear Information System (INIS)

    Antoniadis, Apostolos; Poulios, Ioannis; Nikolakaki, Eleni; Mantzavinos, Dionissios

    2007-01-01

    The application of high intensity, low frequency ultrasound for the disinfection of simulated and septic tank wastewaters is evaluated in this work. Laboratory scale experiments were conducted at 24 and 80 kHz ultrasound frequency with horn-type sonicators capable of operating in continuous and pulsed irradiation modes at nominal ultrasound intensities up to 450 W. For the experiments with simulated wastewaters, Escherichia coli were used as biological indicator of disinfection efficiency, while for the experiments with septic tank wastewaters, the total microbiological load was used. Complete elimination of E. coli could be achieved within 20-30 min of irradiation at 24 kHz and 450 W with the efficiency decreasing with decreasing intensity and frequency. Moreover, continuous irradiation was more effective than intermittent treatment based on a common energy input. Irradiation of the septic tank effluent prior to biological treatment at 24 kHz and 450 W for 30 min resulted in a three-log total microbiological load reduction, and this was nearly equal to the reduction that could be achieved during biological treatment. Bacterial cell elimination upon irradiation was irreversible as no reappearance of the microorganisms occurred after 24 h

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

    Energy Technology Data Exchange (ETDEWEB)

    Lui, Gough Yumu, E-mail: gough@student.unsw.edu.au [UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); School of Photovoltaics and Renewable Energy Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Roser, David, E-mail: djroser@unsw.edu.au [UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Corkish, Richard, E-mail: r.corkish@unsw.edu.au [School of Photovoltaics and Renewable Energy Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Ashbolt, Nicholas J., E-mail: ashbolt@ualberta.ca [UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); School of Public Health, South Academic Building, University of Alberta, Edmonton, Alberta T6G 2G7 (Canada); Stuetz, Richard, E-mail: r.stuetz@unsw.edu.au [UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia)

    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 6 h. Five log{sub 10} 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-log{sub 10}s E. coli and E. faecalis over the 6 h). 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-log{sub 10} 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. - Highlights: • Disinfection of E. coli and E. faecalis achieved with 270 and 365–455 nm LEDs • No significant disinfection was found with 310 and > 455 nm LEDs

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    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 6 h. Five log_1_0 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-log_1_0s E. coli and E. faecalis over the 6 h). 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-log_1_0 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. - Highlights: • Disinfection of E. coli and E. faecalis achieved with 270 and 365–455 nm LEDs • No significant disinfection was found with 310 and > 455 nm LEDs. • UV

  11. Dating by electron paramagnetic resonance

    International Nuclear Information System (INIS)

    Poupeau, G.; Rossi, A.M.

    1984-01-01

    Some natural materials behave like dosimeters in front of the ionizing particle flux coming from environmental radioactivity and the cosmic radiation. This property is used for the dating by Electron Paramagnetic Resonance (EPR). Before presenting the basic principles of the EPR analysis and the dating method which uses such a phenomenous, it is reviewed several types of application currently in course of development. (L.C.) [pt

  12. Ultraviolet disinfection of treated municipal wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Vander Laan, H; Cairns, B

    1993-12-31

    A wastewater disinfection system developed by a Canadian company, Trojan Technologies Inc., was discussed. Disinfection for pathogen reduction prior to discharge of treated municipal wastewater back into rivers and lakes has been either ignored or treated by the use of chemicals. In 1979 the first pilot ultraviolet (UV) wastewater disinfection system was established. Since then, over 500 municipal UV installations have been commissioned. The largest installation can process 212 million gallons of water per day. The advantages of UV as a disinfectant are: (1) It is more effective than chlorine. (2) There are no mutagenic/carcinogenic byproducts formed with UV. (3) No toxic chemical residuals are discharged. (4) UV is safe to both the operators and the public. (5) It is cost effective. Europe has not been as active in wastewater disinfection as has North America. One result of the absence of wastewater disinfection in Europe is that the Rhine River, for example, carries 50 million salmonella per second. Disinfection of wastewater effluents is, of course, indispensable in protecting our drinking water supply. 2 figs.

  13. TL and EPR dating: some applications

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, S. [Institute of Physics, University of Sao Paulo, Sao Paulo (Brazil)

    2006-07-01

    The intensity of thermoluminescence light emitted by a crystal is a function of radiation dose. The number of defects or of radicals in a crystal or organic substances is also a function of radiation dose. Since such defects or radicals present EPR signals, the EPR intensity is also a function of radiation dose. These facts are basis for radiation dosimetry and can be applied in dating of archaeological potteries or other materials, as well as in dating geological substances such as sediments, caves speleothemes, animal teeth and bones. Recent investigation on sensitized quartz based dosimeters and dating calcite covering ancient wall painting to find early settlers in Brazil will be presented. (Author)

  14. Disinfection of human musculoskeletal allografts in tissue banking: a systematic review.

    Science.gov (United States)

    Mohr, J; Germain, M; Winters, M; Fraser, S; Duong, A; Garibaldi, A; Simunovic, N; Alsop, D; Dao, D; Bessemer, R; Ayeni, O R

    2016-12-01

    Musculoskeletal allografts are typically disinfected using antibiotics, irradiation or chemical methods but protocols vary significantly between tissue banks. It is likely that different disinfection protocols will not have the same level of microorganism kill; they may also have varying effects on the structural integrity of the tissue, which could lead to significant differences in terms of clinical outcome in recipients. Ideally, a disinfection protocol should achieve the greatest bioburden reduction with the lowest possible impact on tissue integrity. A systematic review of three databases found 68 laboratory and clinical studies that analyzed the microbial bioburden or contamination rates of musculoskeletal allografts. The use of peracetic acid-ethanol or ionizing radiation was found to be most effective for disinfection of tissues. The use of irradiation is the most frequently published method for the terminal sterilization of musculoskeletal allografts; it is widely used and its efficacy is well documented in the literature. However, effective disinfection results were still observed using the BioCleanse™ Tissue Sterilization process, pulsatile lavage with antibiotics, ethylene oxide, and chlorhexidine. The variety of effective methods to reduce contamination rate or bioburden, in conjunction with limited high quality evidence provides little support for the recommendation of a single bioburden reduction method.

  15. Solar water disinfection (SODIS): A review from bench-top to roof-top

    Energy Technology Data Exchange (ETDEWEB)

    McGuigan, Kevin G., E-mail: kmcguigan@rcsi.ie [Royal College of Surgeons in Ireland, Dublin 2 (Ireland); Conroy, Ronan M. [Royal College of Surgeons in Ireland, Dublin 2 (Ireland); Mosler, Hans-Joachim [EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133: CH-8600 Duebendorf (Switzerland); Preez, Martella du; Ubomba-Jaswa, Eunice [CSIR, Natural Resources and the Environment, Pretoria, Gauteng (South Africa); Fernandez-Ibanez, Pilar [Plataforma Solar de Almeria - CIEMAT, P.O. Box 22, 07200 Tabernas, Almeria (Spain)

    2012-10-15

    Graphical abstract: . Water being treated by solar disinfection outside a primary school classroom in Southern Uganda. Students fill their bottles at home and expose them to the sun while they are at school. Highlights: Black-Right-Pointing-Pointer A thorough review of current state of play of solar water disinfection. Black-Right-Pointing-Pointer An examination of both laboratory and field studies. Black-Right-Pointing-Pointer Description of the economic and behaviour change aspects of this technology. - Abstract: 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 2 L PET beverage bottles) which are then exposed to the sun. Exposure times vary from 6 to 48 h 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.

  16. Solar water disinfection (SODIS): A review from bench-top to roof-top

    International Nuclear Information System (INIS)

    McGuigan, Kevin G.; Conroy, Ronán M.; Mosler, Hans-Joachim; Preez, Martella du; Ubomba-Jaswa, Eunice; Fernandez-Ibañez, Pilar

    2012-01-01

    Graphical abstract: . Water being treated by solar disinfection outside a primary school classroom in Southern Uganda. Students fill their bottles at home and expose them to the sun while they are at school. Highlights: ► A thorough review of current state of play of solar water disinfection. ► An examination of both laboratory and field studies. ► Description of the economic and behaviour change aspects of this technology. - Abstract: 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 2 L PET beverage bottles) which are then exposed to the sun. Exposure times vary from 6 to 48 h 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.

  17. Dating and Sexual Feelings

    Science.gov (United States)

    ... Home Body Your sexuality Dating and sexual feelings Dating and sexual feelings Thinking about romance, starting to ... you learn how to stay healthy and strong. Dating older guys top If you date someone even ...

  18. ASSESSMENT OF THE EFFICIENCY OF DISINFECTION METHOD ...

    African Journals Online (AJOL)

    eobe

    ABSTRACT. The efficiencies of three disinfection methods namely boiling, water guard and pur purifier were assessed. ... Water is an indispensable resource for supporting life systems [2- ...... developing country context: improving decisions.

  19. Enhancement of ultraviolet water disinfection process

    African Journals Online (AJOL)

    grabi-1

    2013-05-15

    May 15, 2013 ... disinfected water distribution systems, including. Legionella .... soft agar, mixed, incubated at room temperature for 2 min and poured onto the ... The determination of a log increase methodology was employed to quantify the ...

  20. PROBIOTIC CLEANING PREPARATIONS VERSUS CHEMICAL DISINFECTANTS

    Directory of Open Access Journals (Sweden)

    W. Luepcke

    2017-12-01

    Full Text Available Probiotic detergents are increasingly used and are a real alternative for limiting the use of chemical cleaners, chemical disinfectants and antibiotics. They therefore have a great future because they contribute to animal health, to the hygienic production of food products of animal origin and to their harmlessness and to consumer health and environmental protection where they even have a beneficial effect on the microflora apart from chemical disinfectants that have a negative impact and destroy the beneficial microflora.

  1. Setting a date

    International Nuclear Information System (INIS)

    Moore, Glenis.

    1987-01-01

    Dating techniques are discussed and explained. The age range and sensitivity of different techniques are given. Potassium/argon dating, amino-acid dating, radiocarbon dating, dendrochronology, thermoluminescence and geomagnetic field dating are all mentioned. Each technique is explained and a brief history given. The techniques and equipment used by the British Museum, and some examples of archaeological articles dated are mentioned. (UK)

  2. [Disinfectants for the skin of premature].

    Science.gov (United States)

    Cucurachi, G; Tuoto, M G

    2010-06-01

    Nosocomial infections are among the leading causes of mortality and morbidity in neonatal intensive care units. Prevention of healthcare-associated infections is based on strategies that aim to limit susceptibility to infections by enhancing host defences, interrupting trasmission of organisms by healthcare workers and by promoting the judicious use of antimicrobials. Strategies for the prevention of nosocomial infections include hand hygiene practices, prevention of central venous (cvc)-related bloodstream infections, judicious use of antimicrobials for therapy, enhancement of host defences, skin care and early enteral feeding with human milk. Major concerns about the use of alcoholic chlorhexidine are for the high risk of skin burns in extremely premature infants during the first days of life, when the skin is thin and not fully keratinesed. Aqueous chlorhexidine could be less irritant when used in very low birthweigth infants and thus could represent a good option. A recent prospective trial of adult patients showed similar effectiveness of alcoholic and aqueos solutions of chlorexidine. However, to date no study evaluated whether the aqueos formulation is less harmful and as effective as the alcoholic formulation in neonatal infants. The lack of evidence for neonatal patients prompts urgent need for large randomised controlled trials comparing effectiveness and safety of different skin disinfectants before CVC placement in neonates and particulary in very low birth-weight infants. Nosocomial infections are still of the most serious problems for the neonatal intensive care unit. Therefore every effort must be implemented to reduce the incidence of these infections, can not be considered a toll required hospitalization, as it may not be acceptable for a place of shelter and care as the hospital may itself be a source of disease.

  3. Predictors of stethoscope disinfection among pediatric health care providers.

    Science.gov (United States)

    Muniz, Jeanette; Sethi, Rosh K V; Zaghi, Justin; Ziniel, Sonja I; Sandora, Thomas J

    2012-12-01

    Stethoscopes are contaminated with bacteria, but predictors of stethoscope disinfection frequency are unknown. We sought to describe health care provider stethoscope disinfection attitudes and practices and determine predictors of frequent disinfection. We used an anonymous online survey of nurses, nurse practitioners, and physicians at a pediatric hospital. We assessed frequency and methods of disinfection, perceptions of contamination, and barriers to disinfection. Multivariate logistic regression models were used to identify independent predictors of disinfecting after every use. One thousand four hundred one respondents completed the survey: 76% believed that infection transmission occurs via stethoscopes, but only 24% reported disinfecting after every use. In multivariate analyses, belief that infection transmission occurs via stethoscopes significantly increased the odds of disinfection after every use (odds ratio [OR], 2.06 [95% confidence interval (CI): 1.38-3.06]). The odds of disinfection after every use were significantly decreased in those who perceived the following barriers: lack of time (OR, 0.31 [95% CI: 0.18-0.54]), lack of access to disinfection material (OR, 0.41 [95% CI: 0.29-0.57]), or lack of visual reminders to disinfect (OR, 0.22 [95% CI: 0.14-0.34]). Only a minority of pediatric health care providers reported disinfecting their stethoscopes after every use. Increasing access to disinfection materials and visual reminders in health care facilities may improve stethoscope disinfection practices. Copyright © 2012 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  4. Optical stimulated luminescence (OSL) dating

    International Nuclear Information System (INIS)

    Banerjee, D.

    1999-01-01

    Since the pioneering work by Huntley et al. (1985), optical dating is being increasingly recognised as an important technique for establishing a time frame of deposition of sediments (Aitken, 1998). Optical dating differs from thermoluminescence (TL) dating in that visible/infrared light from lasers or LEDs (light-emitting-diodes) is used as a means of stimulation, in contrast to thermal stimulation. It has several advantages over TL dating: (i) the resetting of the OSL (optically stimulated luminescence) clock is more effective than that of TL clock; for sediments transported under water or in other situations where the sediment grains have undergone inhomogeneous bleaching, this property ensures that ages based on optical dating are generally more reliable than TL ages, (ii) the optical dating technique is non-destructive, and multiple readouts of the optical signal is possible; this feature has resulted in the development of single-aliquot and single-grain protocols (Murray and Wintle, 1999; Banerjee et al. 1999), (iii) the sample is not heated as in TL; thus, spurious luminescence is avoided and there is a significant reduction in blackbody radiation. Dating of materials which change phase on heating is also practical, and finally, (iv) thermal quenching of luminescence is negligible, allowing accurate estimation of kinetic parameters using standard techniques and providing access to deep OSL traps. This characteristic may be helpful in extending the limits of optical dating beyond the last 150 ka from a global point of view

  5. Ultraviolet light-emitting diodes in water disinfection.

    Science.gov (United States)

    Vilhunen, Sari; Särkkä, Heikki; Sillanpää, Mika

    2009-06-01

    The novel system of ultraviolet light-emitting diodes (UV LEDs) was studied in water disinfection. Conventional UV lamps, like mercury vapor lamp, consume much energy and are considered to be problem waste after use. UV LEDs are energy efficient and free of toxicants. This study showed the suitability of LEDs in disinfection and provided information of the effect of two emitted wavelengths and different test mediums to Escherichia coli destruction. Common laboratory strain of E. coli (K12) was used and the effects of two emitted wavelengths (269 and 276 nm) were investigated with two photolytic batch reactors both including ten LEDs. The effects of test medium were examined with ultrapure water, nutrient and water, and nutrient and water with humic acids. Efficiency of reactors was almost the same even though the one emitting higher wavelength had doubled optical power compared to the other. Therefore, the effect of wavelength was evident and the radiation emitted at 269 nm was more powerful. Also, the impact of background was studied and noticed to have only slight deteriorating effect. In the 5-min experiment, the bacterial reduction of three to four log colony-forming units (CFU) per cubic centimeter was achieved, in all cases. When turbidity of the test medium was greater, part of the UV radiation was spent on the absorption and reactions with extra substances on liquid. Humic acids can also coat the bacteria reducing the sensitivity of the cells to UV light. The lower wavelength was distinctly more efficient when the optical power is considered, even though the difference of wavelengths was small. The reason presumably is the greater absorption of DNA causing more efficient bacterial breakage. UV LEDs were efficient in E. coli destruction, even if LEDs were considered to have rather low optical power. The effect of wavelengths was noticeable but the test medium did not have much impact. This study found UV LEDs to be an optimal method for bacterial

  6. Efficient Disinfection of Tap and Surface Water with Single High Power 285 nm LED and Square Quartz Tube

    Directory of Open Access Journals (Sweden)

    Martin Hessling

    2016-01-01

    Full Text Available A small water disinfection system based on the combination of a strong single 25 mW LED with a wavelength of 285 nm and a short quartz tube with an outer rectangular cross section is presented. For the disinfection tests clear tap water and slightly turbid and yellow pond water are contaminated with high concentrations of Escherichia coli bacteria. These water samples are exposed to the germicidal 285 nm LED radiation while they flow through the quartz tube. The portion of surviving germs is determined by membrane filtration for different water qualities and flow rates. For clear tap water the bacteria concentration can be reduced by at least three orders of magnitude up to flow rates of about 20 L/h. In pond water the maximum flow rate for such a reduction is less than 3 L/h. These high disinfection capabilities and the small size of this system, allow its integration in medical systems for point of use disinfection or even its application in the Third World for decentralized water disinfection powered by small solar cells, because this disinfection capacity should be sufficient for small groups or families.

  7. Optimization of fixed titanium dioxide film on PET bottles and visual indicator for water disinfection

    Science.gov (United States)

    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.

  8. Chemical U-Th-Pb dating of monazite by 3D-Micro x-ray fluorescence analysis with synchrotron radiation

    DEFF Research Database (Denmark)

    Schmitz, Susanne; Möller, Andreas; Wilke, Max

    2009-01-01

    A confocal set-up for three-dimensional (3D) micro X-ray fluorescence (micro-XRF) was used at the mySpot beamline at BESSY II, which allows compositional depth profiling for various applications. We present results obtained with a confocal 3D micro-XRF set-up for chemical age dating using the U, Th...... and Pb concentrations of monazite within rock thin sections. The probing volume was determined to be approximately 21 × 21 × 24 µm3 for W-La using an excitation energy of 19 keV. The relative detection limits particularly for Pb are below 10 ppm (for counting times of 1000 s). Therefore, this 3D micro...... of ages, varying from 20 Ma to 1.82 Ga. Reference materials (GM3, F6, 3345) can be reproduced within error. The spread in the ages of all points determined by 3D micro-XRF is within 8 % of the isotopic reference value. The average 3D micro-XRF dates reproduce the reference ages with discrepancies between...

  9. Hospital disinfection: efficacy and safety issues.

    Science.gov (United States)

    Dettenkofer, Markus; Block, Colin

    2005-08-01

    To review recent publications relevant to hospital disinfection (and cleaning) including the reprocessing of medical instruments. The key question as to whether the use of disinfectants on environmental surfaces rather than cleaning with detergents only reduces nosocomial infection rates still awaits conclusive studies. New disinfectants, mainly peroxygen compounds, show good sporicidal properties and will probably replace more problematical substances such as chlorine-releasing agents. The safe reprocessing of medical devices requires a well-coordinated approach, starting with proper cleaning. New methods and substances show promising activity for preventing the transmission of prions. Different aspects of virus inactivation have been studied, and the transmissibility, e.g. of norovirus, shows the need for sound data on how different disinfectant classes perform. Biofilms or other forms of surface-adherent organisms pose an extraordinary challenge to decontamination. Although resistance to biocides is generally not judged to be as critical as antibiotic resistance, scientific data support the need for proper use, i.e. the avoidance of widespread application, especially in low concentrations and in consumer products. Chemical disinfection of heat-sensitive instruments and targeted disinfection of environmental surfaces are established components of hospital infection control. To avoid danger to staff, patients and the environment, prudent use as well as established safety precautions are required. New technologies and products should be evaluated with sound methods. As emerging resistant pathogens will challenge healthcare facilities in the future even more than at present, there is a need for well-designed studies addressing the role of disinfection in hospital infection control.

  10. Inactivation of an enterovirus by airborne disinfectants

    Science.gov (United States)

    2013-01-01

    Background The activity of airborne disinfectants on bacteria, fungi and spores has been reported. However, the issue of the virucidal effect of disinfectants spread by fogging has not been studied thoroughly. Methods A procedure has been developed to determine the virucidal activity of peracetic acid-based airborne disinfectants on a resistant non-enveloped virus poliovirus type 1. This virus was laid on a stainless carrier. The products were spread into the room by hot fogging at 55°C for 30 minutes at a concentration of 7.5 mL.m-3. Poliovirus inoculum, supplemented with 5%, heat inactivated non fat dry organic milk, were applied into the middle of the stainless steel disc and were dried under the air flow of a class II biological safety cabinet at room temperature. The Viral preparations were recovered by using flocked swabs and were titered on Vero cells using the classical Spearman-Kärber CPE reading method, the results were expressed as TCID50.ml-1. Results The infectious titer of dried poliovirus inocula was kept at 105 TCID50.mL-1 up to 150 minutes at room temperature. Dried inocula exposed to airborne peracetic acid containing disinfectants were recovered at 60 and 120 minutes post-exposition and suspended in culture medium again. The cytotoxicity of disinfectant containing medium was eliminated through gel filtration columns. A 4 log reduction of infectious titer of dried poliovirus inocula exposed to peracetic-based airborne disinfectant was obtained. Conclusion This study demonstrates that the virucidal activity of airborne disinfectants can be tested on dried poliovirus. PMID:23587047

  11. Performance of on-site Medical waste disinfection equipment in hospitals of Tabriz, Iran

    Directory of Open Access Journals (Sweden)

    Hassan Taghipour

    2016-10-01

    Full Text Available Background: The number of studies available on the performance of on-site medical waste treatment facilities is rare, to date. The aim of this study was to evaluate the performance of onsite medical waste treatment equipment in hospitals of Tabriz, Iran. Methods: A various range of the on-site medical waste disinfection equipment (autoclave, chemical disinfection, hydroclave, and dry thermal treatment was considered to select 10 out of 22 hospitals in Tabriz to be included in the survey. The apparatus were monitored mechanically, chemically, and biologically for a six months period in all of the selected hospitals. Results: The results of the chemical monitoring (Bowie-Dick tests indicated that 38.9% of the inspected autoclaves had operational problems in pre-vacuum, air leaks, inadequate steam penetration into the waste, and/or vacuum pump. The biological indicators revealed that about 55.55% of the samples were positive. The most of applied devices were not suitable for treating anatomical, pharmaceutical, cytotoxic, and chemical waste. Conclusion: Although on-site medical waste treating facilities have been installed in all the hospitals, the most of infectious-hazardous medical waste generated in the hospitals were deposited into a municipal solid waste landfill, without enough disinfection. The responsible authorities should stringently inspect and evaluate the operation of on-site medical waste treating equipment. An advanced off-site central facility with multi-treatment and disinfection equipment and enough capacity is recommended as an alternative.

  12. A practical evaluation of detergent and disinfectant solutions on ...

    African Journals Online (AJOL)

    Student01

    2012-01-06

    Jan 6, 2012 ... Nine sanitation chemical solutions: benzalkonium chloride, sodium hypochlorite, nitric ... cleaning and disinfection in reducing selected bacteria levels as required by ..... bacteria targeted during disinfection are attached to a.

  13. Basic Information about Chloramines and Drinking Water Disinfection

    Science.gov (United States)

    Chloramines are disinfectants used to treat drinking water. Chloramines are most commonly formed when ammonia is added to chlorine to treat drinking water. Chloramines provide longer-lasting disinfection as the water moves through pipes to consumers.

  14. Study and application of herbal disinfectants in China.

    Science.gov (United States)

    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.

  15. [Experimental evaluation of the spraying disinfection efficiency on dental models].

    Science.gov (United States)

    Zhang, Yi; Fu, Yuan-fei; Xu, Kan

    2013-08-01

    To evaluate the disinfect effect after spraying a new kind of disinfectant on the dental plaster models. The germ-free plaster samples, which were smeared with bacteria compound including Staphylococcus aureus, Escherichia coli, Saccharomyces albicans, Streptococcus mutans and Actinomyces viscosus were sprayed with disinfectants (CaviCide) and glutaraldehyde individually. In one group(5 minutes later) and another group(15 minutes later), the colonies were counted for statistical analysis after sampling, inoculating, and culturing which were used for evaluation of disinfecting efficiency. ANOVA was performed using SPSS12.0 software package. All sample bacteria were eradicated after spraying disinfectants(CaviCide) within 5 minutes and effective bacteria control was retained after 15 minutes. There was significant difference between the disinfecting efficiency of CaviCide and glutaraldehyde. The effect of disinfection with spraying disinfectants (CaviCide) on dental models is quick and effective.

  16. Disinfection for small water supplies: a technical guide

    CSIR Research Space (South Africa)

    Solsona, F

    1990-01-01

    Full Text Available This guide will present some disinfection systems, which will be useful in supporting disinfection programmes. The description of the different systems will provide a guideline for the selection of equipment base on balancing the simplicity...

  17. Understanding Teen Dating Violence

    Science.gov (United States)

    Understanding Teen Dating Violence Fact Sheet 2014 Dating violence is a type of intimate partner violence. It occurs between two people in a close relationship. The nature of dating violence can be physical, emotional, or sexual. • Physical— This ...

  18. Teen Dating Violence

    Science.gov (United States)

    ... Room Social Media Publications Injury Center Teen Dating Violence Recommend on Facebook Tweet Share Compartir On This ... serious forms of violence. What is teen dating violence? Teen Dating Violence [550 KB, 2 Pages, 508] ...

  19. OPTIMAL SCHEDULING OF BOOSTER DISINFECTION IN WATER DISTRIBUTION SYSTEMS

    Science.gov (United States)

    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...

  20. Studies on Disinfection By-Products and Drinking Water

    Science.gov (United States)

    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.

  1. Chemical aspects of peracetic acid based wastewater disinfection ...

    African Journals Online (AJOL)

    Peracetic acid (PAA) has been studied for wastewater disinfection applications for some 30 years and has been shown to be an effective disinfectant against many indicator microbes, including bacteria, viruses, and protozoa. One of the key advantages compared to, e.g., chlorine is the lack of harmful disinfection ...

  2. 40 CFR 141.172 - Disinfection profiling and benchmarking.

    Science.gov (United States)

    2010-07-01

    ... benchmarking. 141.172 Section 141.172 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Disinfection-Systems Serving 10,000 or More People § 141.172 Disinfection profiling and benchmarking. (a... sanitary surveys conducted by the State. (c) Disinfection benchmarking. (1) Any system required to develop...

  3. Effects of some antiseptics and disinfectants on Staphylococcus ...

    African Journals Online (AJOL)

    A total of 6 antiseptics and disinfectants at varying concentrations (20% - 100%) and contact time (10-60 minutes) were tested for the efficacy in the reduction of Staphylococcus aureus isolated from the hands of volunteers. Disinfectant 1 was the most effective disinfectant being bactericidal to S. aureus at 100% ...

  4. 9 CFR 91.41 - Cleaning and disinfecting of aircraft.

    Science.gov (United States)

    2010-01-01

    ... of this chapter. The time at which the cleaning and disinfection is performed must be approved by the inspector, who will give approval only if he or she determines that the cleaning and disinfection will be... time, the inspector shall determine whether further cleaning and disinfection are necessary. The...

  5. Treatment and Recycling Process for Biosolids by Radiation

    International Nuclear Information System (INIS)

    Lee, J. K.; Yoo, D. H.; Lee, B. J.; Park, C. K.; Lee, M. J.

    2005-01-01

    The volume of sludge is increasing rapidly on a yearly basis in Korea. Liquid sewage sludge generated in Korea has been treated as reuse (7%), landfill (5%), incineration (12%) and ocean dump (72%) in 2003 [1]. Ocean dump is the main treatment of sewage sludge up to date but incineration and landfill will be increased because Korean government will restrict ocean dump in the near future. Desirable treatment of sewage sludge is still a sensitive issue though many scientists have vigorously studied the safe and environmentally sound treatment of sewage sludge and reducing sludge cake. Therefore reduction of moisture content in sludge and recycling by radiation is the main objective in this work. Here we studied the radiation technique as a pretreatment process to enhance sludge dewaterability, to disinfect micro-organisms, and to remove the toxic organics in sewage sludge simultaneously. The improvement of sludge compost after irradiation was also observed to develop the method for recycling of sludge

  6. Technical considerations during disinfection by UV

    International Nuclear Information System (INIS)

    Ekhtiarzadeh, Z.; Sadeghpur, H.

    2002-01-01

    The use of new methods for treatment of water and wastewater in the country is one the rise and therefore the theoretical and practical knowledge of the industry's engineers should increase simultaneously. Ultraviolet is one of the new technologies used both for treatment of water as well as wastewater. The UV disinfection system consists of different components such as the lamp, ballast and the lamp fixtures. Each has a specification, which should be taken into account prior to design, order and purchase. The subject of price is also among the important considerations. The article presents figures cost comparison in various sections. It does not try to either approve or reject other disinfection systems such as chlorination, but the writer believes that any method should find its own practice and conditions of use, and the disinfection system designers should opt for the best system suited to their plans and avoid limiting themselves to a single one

  7. Activity and action screening of selected disinfectants

    Directory of Open Access Journals (Sweden)

    Kateřina Balharová

    2006-01-01

    Full Text Available This research work is aimed to monitoring of selected disinfectants´activity in operational conditions. Hereby there have been monitored two acidic disinfectants Despon K and Mikasan D, which have had-by their producer-stated different recommended concentration. These solutions were monitored in viewpoint of their activity at different temperature, time of circulation, pH and water hardness. In this work there were measured pH of solutions in unloaded medium to be compared with pH of solutions in loaded medium and this measuring was carried out regularly each week within a one month period. During this period there was also monitored total plate count (TPC, which was stated in the dairy, where samples were taken two-times monthly. It has been found, that the disinfectants Mikasan D and Mikal 94D are effective even by high water hardness.

  8. Ultraviolet air disinfection for protection against influenza

    International Nuclear Information System (INIS)

    Riley, R.L.

    1977-01-01

    Three converging lines of evidence support the belief that it may be possible, under appropriate circumstances, to interrupt the airborne transmission of influenza by ultraviolet (UV) air disinfection. These lines of evidence are: (a) that influenza is airborne; (b) that UV irradiation of the upper air of a room can provide safe and effective disinfection of air in the lower part of the room; and (c) that epidemic spread of airborne viral infections in humans can be prevented if the population under consideration remains in the UV-protected environment

  9. Drinking water contamination and it's disinfection

    International Nuclear Information System (INIS)

    Shah, P.M.J.

    2005-01-01

    High quality water is necessary for the survival of human life. In this paper, an effort has been made to highlight the various causes of water contamination. Some of the most common impurities present in water are pathogenic microorganisms along with organize and in organize pollutants. Different treatment methods are adopted to ensure the potability of water. They include physical, chemical and ultra viable treatment along with solar disinfection etc. The adoption of a particular disinfection strategy depends on the level of treatment required and the resources available to carry out such a treatment. (author)

  10. The role of 'no-touch' automated room disinfection systems in infection prevention and control.

    Science.gov (United States)

    Otter, J A; Yezli, S; Perl, T M; Barbut, F; French, G L

    2013-01-01

    Surface contamination in hospitals is involved in the transmission of pathogens in a proportion of healthcare-associated infections. Admission to a room previously occupied by a patient colonized or infected with certain nosocomial pathogens increases the risk of acquisition by subsequent occupants; thus, there is a need to improve terminal disinfection of these patient rooms. Conventional disinfection methods may be limited by reliance on the operator to ensure appropriate selection, formulation, distribution and contact time of the agent. These problems can be reduced by the use of 'no-touch' automated room disinfection (NTD) systems. To summarize published data related to NTD systems. Pubmed searches for relevant articles. A number of NTD systems have emerged, which remove or reduce reliance on the operator to ensure distribution, contact time and process repeatability, and aim to improve the level of disinfection and thus mitigate the increased risk from the prior room occupant. Available NTD systems include hydrogen peroxide (H(2)O(2)) vapour systems, aerosolized hydrogen peroxide (aHP) and ultraviolet radiation. These systems have important differences in their active agent, delivery mechanism, efficacy, process time and ease of use. Typically, there is a trade-off between time and effectiveness among NTD systems. The choice of NTD system should be influenced by the intended application, the evidence base for effectiveness, practicalities of implementation and cost constraints. NTD systems are gaining acceptance as a useful tool for infection prevention and control. Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  11. Solar disinfection: an approach for low-cost household water treatment technology in Southwestern Ethiopia.

    Science.gov (United States)

    Dessie, Awrajaw; Alemayehu, Esayas; Mekonen, Seblework; Legesse, Worku; Kloos, Helmut; Ambelu, Argaw

    2014-01-10

    Disinfection of contaminated water using solar radiation (SODIS) is known to inactivate bacteria. Its inactivation efficiency depends on local conditions where the disinfection is made. This study was aiming to test the efficiency of solar disinfection using different water parameters as low-cost household water treatment technology. Inactivation of microbes was tested using fecal coliform as test organism. The SODIS experiment was carried out at turbidity 2NTU, pH 7, and various water temperature (38.1°C, 41.8°C, 45.6°Cand 51.1°C) and solar intensities, using clear and black plastic bottles filled to different depths. The results show that the rate of microbial inactivation in relation to depth of water, turbidity, container type, intensity of light and color of container was statistically significant (p solar disinfection. By adjusting the parameters, complete and irreversible fecal coliform inactivation was achieved within an exposure time of less than four hours in the areas where the solar irradiance is about 3.99 kW/m2 and above. Our results indicate that application of SODIS could play a significant role in the provision of safe water in rural communities of developing countries where there is ample sunshine, specifically in sub-Saharan African countries.

  12. Sensitivity to disinfection of bacterial indicator organisms for monitoring the Salmonella Enteritidis status of layer farms after cleaning and disinfection.

    Science.gov (United States)

    Dewaele, I; Ducatelle, R; Herman, L; Heyndrickx, M; De Reu, K

    2011-06-01

    The present study evaluated Escherichia coli, Enterococcus faecalis, and Enterococcus hirae as potential indicator organisms for the possible Salmonella Enteritidis (SE) presence in layer farms after cleaning and disinfection by comparing their susceptibility to disinfection. A quantitative suspension disinfection test according to European Standard EN1656 was performed using disinfection products CID20 and Virocid (both from CID Lines, Ieper, Belgium). In a preliminary test, the sensitivity to both disinfection products was compared between ATCC strains of SE, E. coli, En. faecalis, and En. hirae. The sensitivity of SE to disinfection was most comparable to that of E. coli. A second disinfection test compared the elimination of E. coli to SE ATCC strains as well as field strains. Results showed no significant effect regarding the strain (P > 0.05 for CID20 and Virocid), meaning that no difference was detected in sensitivity toward disinfection. When comparing the sensitivity in general at species level for all concentrations of disinfectant used, no significant difference was found between E. coli and SE in sensitivity to Virocid (P > 0.05). In conclusion, because of its similar response to disinfection in a suspension disinfection test, E. coli could be used as an indicator for possible Salmonella presence after cleaning and disinfection.

  13. Potential role of intense ionising radiation sources in municipal sludge management and environmental protection

    International Nuclear Information System (INIS)

    Krishnamurthy, K.

    1980-01-01

    Magnitude of the problem of safe disposal of sewage and sludge is explained. With rapid increase in the quantum of generated municipal and industrial wastes, their disposal on land or in sea is becoming harmful to public health, hazardous to aquatic life and disturbing to ecological balance. These wastes can be recycled, but to make this recycling beneficial and at the same time harmless to public health, the wastes must be disinfected. Radiation disinfection of sewage and sludge is examined as one of the ways of disinfection. Irradiation can be carried out with gamma radiation or energised electrons. Techniques of radiation disinfection and radiation doses required for disinfection are discussed. Case studies of a few radiation plants for sludge disinfection are presented. They include the Palmdale Plant in Florida, Sandia Irradiator at Albuqurque, New Mexico, Energised Electron Facility at Deer Island, Boston - all these in U.S.A., and the Munich Plant in West Germany. Mention has been made to the work in progress in India on the design of irradiators. Reference has been made to the proposed electron irradiation system for destruction of toxic chemicals such as PCB in drinking water and for disinfection of secondary water. Economics of radiation disinfection is also discussed and it is noted that the radiation process can become economically competitive when cheap sources of radiation become available. (M.G.B.)

  14. Progress in radiocarbon dating

    International Nuclear Information System (INIS)

    Hedges, R.E.M.

    1985-01-01

    The article concerns radiocarbon dating, the most important method for dating in archaeology. The principles and practice of the dating method are described. Recent developments in radiocarbon dating due to technical advances, are discussed, and include radiometric counting of small samples and accelerator mass spectrometry. Carbon isotopes and the environment are also discussed. (U.K.)

  15. ESR dating of fault rocks

    International Nuclear Information System (INIS)

    Lee, Hee Kwon

    2002-03-01

    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then trow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs grain size shows a plateau for grains below critical size : these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected from the Yangsan fault system. ESR dates from the this fault system range from 870 to 240 ka. Results of this research suggest that long-term cyclic fault activity continued into the pleistocene

  16. ESR dating of fault rocks

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Kwon [Kangwon National Univ., Chuncheon (Korea, Republic of)

    2002-03-15

    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then trow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs grain size shows a plateau for grains below critical size : these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected from the Yangsan fault system. ESR dates from the this fault system range from 870 to 240 ka. Results of this research suggest that long-term cyclic fault activity continued into the pleistocene.

  17. Pulsed high voltage electric discharge disinfection of microbially contaminated liquids.

    Science.gov (United States)

    Anpilov, A M; Barkhudarov, E M; Christofi, N; Kop'ev, V A; Kossyi, I A; Taktakishvili, M I; Zadiraka, Y

    2002-01-01

    To examine the use of a novel multielectrode slipping surface discharge (SSD) treatment system, capable of pulsed plasma discharge directly in water, in killing micro-organisms. Potable water containing Escherichia coli and somatic coliphages was treated with pulsed electric discharges generated by the SSD. The SSD system was highly efficient in the microbial disinfection of water with a low energy utilization (eta approximately 10-4 kW h l-1). The SSD treatment was effective in the destruction of E. coli and its coliphages through the generation of u.v. radiation, ozone and free radicals. The non-thermal treatment method can be used for the eradication of micro-organisms in a range of contaminated liquids, including milk, negating the use of pasteurization. The method utilizes multipoint electric discharges capable of treating large volumes of liquid under static and flowing regimes.

  18. Characterization of unknown iodinated disinfection byproducts during chlorination/chloramination using ultrahigh resolution mass spectrometry

    International Nuclear Information System (INIS)

    Wang, Xin; Wang, Juan; Zhang, Yahe; Shi, Quan; Zhang, Haifeng; Zhang, Yu; Yang, Min

    2016-01-01

    Iodinated disinfection byproducts (I-DBPs), formed from the reaction of disinfectant(s) with organic matter in the presence of iodide in raw water, have recently been focused because of their more cytotoxic and genotoxic properties than their chlorinated or brominated analogues. To date, only a few I-DBPs in drinking water have been identified. In this study, C18 solid phase extraction coupled with electrospray ionization ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) was used to characterize unknown I-DBPs in chloraminated/chlorinated water spiked with iodide and humic substances. In total, 178 formulas for one-iodine-containing products, 13 formulas for two-iodine-containing products, and 15 formulas for one-chlorine and one-iodine-containing products were detected in the chloraminated water sample, while only 9 formulas for one-iodine-containing products and 6 formulas for one-chlorine and one-iodine-containing products were found in the chlorinated water sample. Most I-DBPs have corresponding chlorine-containing analogues with identical CHO compositions. As indicated by the modified aromaticity index (AI mod ), in the C18 extracts, more than 68% of the I-DBPs have aromatic structures or polycyclic aromatic structures. This result demonstrates that the use of chloramination as an alternative disinfection method may lead to the formation of abundant species of I-DBPs in the presence of iodide. Thus, the suitability of adopting chloramination as an alternative disinfection method should be reevaluated, particularly when iodide is present in raw water. - Highlights: • The formulas of 206 iodinated DBPs in chloraminated drinking water were proposed. • More than 68% of the I-DBPs might have aromatic or polycyclic aromatic structures. • Precursors with high aromaticity is preferential to form iodinated DBPs.

  19. Characterization of unknown iodinated disinfection byproducts during chlorination/chloramination using ultrahigh resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin; Wang, Juan [State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Zhang, Yahe; Shi, Quan [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249 (China); Zhang, Haifeng; Zhang, Yu [State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Yang, Min, E-mail: yangmin@rcees.ac.cn [State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)

    2016-06-01

    Iodinated disinfection byproducts (I-DBPs), formed from the reaction of disinfectant(s) with organic matter in the presence of iodide in raw water, have recently been focused because of their more cytotoxic and genotoxic properties than their chlorinated or brominated analogues. To date, only a few I-DBPs in drinking water have been identified. In this study, C18 solid phase extraction coupled with electrospray ionization ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) was used to characterize unknown I-DBPs in chloraminated/chlorinated water spiked with iodide and humic substances. In total, 178 formulas for one-iodine-containing products, 13 formulas for two-iodine-containing products, and 15 formulas for one-chlorine and one-iodine-containing products were detected in the chloraminated water sample, while only 9 formulas for one-iodine-containing products and 6 formulas for one-chlorine and one-iodine-containing products were found in the chlorinated water sample. Most I-DBPs have corresponding chlorine-containing analogues with identical CHO compositions. As indicated by the modified aromaticity index (AI{sub mod}), in the C18 extracts, more than 68% of the I-DBPs have aromatic structures or polycyclic aromatic structures. This result demonstrates that the use of chloramination as an alternative disinfection method may lead to the formation of abundant species of I-DBPs in the presence of iodide. Thus, the suitability of adopting chloramination as an alternative disinfection method should be reevaluated, particularly when iodide is present in raw water. - Highlights: • The formulas of 206 iodinated DBPs in chloraminated drinking water were proposed. • More than 68% of the I-DBPs might have aromatic or polycyclic aromatic structures. • Precursors with high aromaticity is preferential to form iodinated DBPs.

  20. A bacteriological study of hospital beds before and after disinfection with phenolic disinfectant

    OpenAIRE

    Denise de Andrade; Emília L. S. Angerami; Carlos Roberto Padovani

    2000-01-01

    In hospitals, one of the ways to control microbial contamination is by disinfecting the furniture used by patients. This study's main objective was to evaluate the microbiological condition of hospital mattresses before and after such disinfection, in order to identify bacteria that are epidemiologically important in nosocomial infection, such as Staphylococcus aureus and Pseudomonas aeruginosa. RODAC plates with two different culture media were used to collect specimens. Patient beds were se...

  1. A bacteriological study of hospital beds before and after disinfection with phenolic disinfectant

    Directory of Open Access Journals (Sweden)

    Andrade Denise de

    2000-01-01

    Full Text Available In hospitals, one of the ways to control microbial contamination is by disinfecting the furniture used by patients. This study's main objective was to evaluate the microbiological condition of hospital mattresses before and after such disinfection, in order to identify bacteria that are epidemiologically important in nosocomial infection, such as Staphylococcus aureus and Pseudomonas aeruginosa. RODAC plates with two different culture media were used to collect specimens. Patient beds were selected according to previously established criteria, and surface areas on the mattresses were chosen at random. From the total of 1 040 plate cultures from 52 mattresses, positive results were obtained from 500 of them (48.1%, 263 before disinfection and 237 after disinfection. Considering the selectivity of the culture media, the positivity rate was high. There were high prevalences of S. aureus both before and after mattress disinfection. The study results suggest that the usual disinfection procedures, instead of diminishing the number of microbes, merely displace them from one part of the mattress to another, and the number of microorganisms remains the same.

  2. A bacteriological study of hospital beds before and after disinfection with phenolic disinfectant

    Directory of Open Access Journals (Sweden)

    Denise de Andrade

    2000-03-01

    Full Text Available In hospitals, one of the ways to control microbial contamination is by disinfecting the furniture used by patients. This study's main objective was to evaluate the microbiological condition of hospital mattresses before and after such disinfection, in order to identify bacteria that are epidemiologically important in nosocomial infection, such as Staphylococcus aureus and Pseudomonas aeruginosa. RODAC plates with two different culture media were used to collect specimens. Patient beds were selected according to previously established criteria, and surface areas on the mattresses were chosen at random. From the total of 1 040 plate cultures from 52 mattresses, positive results were obtained from 500 of them (48.1%, 263 before disinfection and 237 after disinfection. Considering the selectivity of the culture media, the positivity rate was high. There were high prevalences of S. aureus both before and after mattress disinfection. The study results suggest that the usual disinfection procedures, instead of diminishing the number of microbes, merely displace them from one part of the mattress to another, and the number of microorganisms remains the same.

  3. Carbon nanoparticles for solar disinfection of water.

    Science.gov (United States)

    Maddigpu, Pratap Reddy; Sawant, Bhairavi; Wanjari, Snehal; Goel, M D; Vione, Davide; Dhodapkar, Rita S; Rayalu, S

    2018-02-05

    The present manuscript deals with the application of carbon nano particles (CNP) and chitosan (CHIT) in the form of CHIT-CNP composite for the disinfection of water. The CHIT-CNP composite was prepared by the solution casting method and characterized by TEM, XRD and elemental analysis. In the present investigation we study the disinfection efficiency towards E. coli bacteria of both CNP and CHIT-CNP, under sunlight (SODIS) in identical experimental conditions. Both CNP and CHIT-CNP enhanced disinfection as compared to SODIS alone, and comparable performance was achieved when the same dose of CNP in the two materials was applied. However, the CHIT-CNP composite is in the form of a fabric and it is easier to use and handle as compared to the CNP powder, especially in rural and resource-constrained areas. Moreover the SODIS-CHIT-CNP setup, when used in a compound parabolic collector (CPC) reactor showed high bactericidal efficiency compared to SODIS alone, which is promising for practical applications. The disinfection potential of the CNP powder was compared with that of the well-known material TiO 2 Degussa P25 (DP 25 ): DP 25 gave 6-log kill of bacteria in 180min, whereas CNP produced 6-log kill in 150min. Copyright © 2017. Published by Elsevier B.V.

  4. essential oil as hatching egg disinfectant

    African Journals Online (AJOL)

    STORAGESEVER

    2010-04-26

    Apr 26, 2010 ... disinfectant for hatching egg obtained from broiler breeder flock. Oregano essential ... contamination rate, hatchability of fertile egg, body weight at 21 and 42 days, body weight gain and total feed ... successful healthy hatchlings. Several ...... Insecticidal properties of essential plant oils against the mosquito.

  5. STERILIZATION AND DISINFECTION IN A PRIVATE CLINIC

    African Journals Online (AJOL)

    Oral examination is done with a mirror and probe. The mirror is then washed under the tap water and disinfected in 'V3 sterilizing' fluid concentrate. The probe is placed in a tray with ... Protective glasses are worn additionally to the gloves and facemask, when cavity preparation. is being performed. The handpiece is wiped.

  6. USE OF FENTON'S REAGENT AS A DISINFECTANT

    Science.gov (United States)

    Combined sewage samples obtained from a wastewater treatment facility were disinfected by the Fenton's Reagent of several different compositions. The pre-settled samples contained both suspended solids (SS) and dissolved organic carbon (DOC) at concentrations of 28 and 290 mg/L,...

  7. Radiations

    International Nuclear Information System (INIS)

    Pujol Mora, J.

    1999-01-01

    The exposition to ionizing radiations is a constant fact in the life of the human being and its utilization as diagnostic and therapeutic method is generalized. However, it is notorious how as years go on, the fear to the ionizing radiation seems to persist too, and this fact is not limited to the common individual, but to the technical personnel and professional personnel that labors with them same. (S. Grainger) [es

  8. Radiation

    International Nuclear Information System (INIS)

    Davidson, J.H.

    1986-01-01

    The basic facts about radiation are explained, along with some simple and natural ways of combating its ill-effects, based on ancient healing wisdom as well as the latest biochemical and technological research. Details are also given of the diet that saved thousands of lives in Nagasaki after the Atomic bomb attack. Special comment is made on the use of radiation for food processing. (U.K.)

  9. Disinfection of dental impressions - compliance to accepted standards.

    Science.gov (United States)

    Almortadi, N; Chadwick, R G

    2010-12-18

    The responsibility of ensuring impressions have been cleaned and disinfected before dispatch to the dental laboratory lies solely with the dentist. Uncertainty of impression disinfection risks both the health of the receiving dental technician and potential repeat disinfection of an already disinfected impression with detrimental consequences for its dimensions. To ascertain, from the perspectives of dentists and dental technicians, current impression decontamination and disinfection practices with, in the case of the technicians, an estimate of the relative prevalence of contaminated voids within apparently disinfected impressions. Anonymous postal questionnaire. Dentist (n = 200) and dental technician (n = 200) potential participants, selected at random from the registers held by the General Dental Council, were invited to complete an anonymous postal questionnaire that sought to establish current practices and perceived effectiveness of impression disinfection. Questionnaire return rates of 42.1% and 31.2% were recorded for dentists and dental technicians respectively. A wide range of solutions, at different dilutions of the same product, was used by the dentists to disinfect dental impressions. 37.2% rinsed the impressions with water, and 2.6% always brushed debris away, before disinfection. 24.7% of dentists did not inform the laboratory of disinfection. Irrespective of the disinfection status of the received impressions, 50% of the responding dental technicians disinfected all impressions. 95% of them had received blood-contaminated impressions. 15% had encountered blood-filled voids upon trimming back the peripheries of impressions. 64.7% were confident that the impressions received by them had been disinfected by the dentists. Compliance with good practice is less than ideal and education in impression disinfection for both dentists and dental technicians is required to address this.

  10. Radiation

    International Nuclear Information System (INIS)

    Winther, J.F.; Ulbak, K.; Dreyer, L.; Pukkala, E.; Oesterlind, A.

    1997-01-01

    Exposure to solar and ionizing radiation increases the risk for cancer in humans. Some 5% of solar radiation is within the ultraviolet spectrum and may cause both malignant melanoma and non-melanocytic skin cancer; the latter is regarded as a benign disease and is accordingly not included in our estimation of avoidable cancers. Under the assumption that the rate of occurrence of malignant melanoma of the buttocks of both men and women and of the scalp of women would apply to all parts of the body in people completely unexposed to solar radiation, it was estimated that approximately 95% of all malignant melanomas arising in the Nordic populations around the year 2000 will be due to exposure to natural ultraviolet radiation, equivalent to an annual number of about 4700 cases, with 2100 in men and 2600 in women, or some 4% of all cancers notified. Exposure to ionizing radiation in the Nordic countries occurs at an average effective dose per capita per year of about 3 mSv (Iceland, 1.1 mSv) from natural sources, and about 1 mSv from man-made sources. While the natural sources are primarily radon in indoor air, natural radionuclides in food, cosmic radiation and gamma radiation from soil and building materials, the man-made sources are dominated by the diagnostic and therapeutic use of ionizing radiation. On the basis of measured levels of radon in Nordic dwellings and associated risk estimates for lung cancer derived from well-conducted epidemiological studies, we estimated that about 180 cases of lung cancer (1% of all lung cancer cases) per year could be avoided in the Nordic countries around the year 2000 if indoor exposure to radon were eliminated, and that an additional 720 cases (6%) could be avoided annually if either radon or tobacco smoking were eliminated. Similarly, it was estimated that the exposure of the Nordic populations to natural sources of ionizing radiation other than radon and to medical sources will each give rise to an annual total of 2120

  11. The performance and applicability study of a fixed photovoltaic-solar water disinfection system

    International Nuclear Information System (INIS)

    Jin, Yanchao; Wang, Yiping; Huang, Qunwu; Zhu, Li; Cui, Yong; Cui, Lingyun

    2016-01-01

    Highlights: • A fixed photovoltaic-SODIS (solar water disinfection) system was constructed. • The system could generate electricity and produce clean water simultaneously. • The daily solar generated electricity was much more than the system consumption. • The system can be used for about 90% of whole year in Lhasa and Chennai. • Temperature enhanced the SODIS process for about 60% days of whole year in Chennai. - Abstract: The objective of the study is to construct and evaluate a fixed PV (photovoltaic) cell integrated with SODIS (solar water disinfection) system to treat drinking water and generate electricity under different climate through experimental and simulation methods. The photovoltaic and disinfection performances of the hybrid system were studied by the disinfection of Escherichia coli. The applicability of the system in Lhasa and Chennai was evaluated by analyzing the daily radiation and predicting the daily water temperature and the system electricity output. The results confirm that the temperature would dramatically enhance the SODIS process and shorten the disinfection time, when the water temperature was above 45 °C. The PV cell in the hybrid system could work under low temperature because of the water layer and the generated electricity was much more than the system consumption. The simulation results show that the days with maximum water temperature above 45 °C were more than 60% of whole year in Chennai. The generated electricity of the hybrid system was 49682.3 W h and 45615.9 W h a year in Lhasa and Chennai respectively. It was sufficient to drive the system of whole year. The number of days which realized drinking water treatment was 324 days in Lhasa and 315 days in Chennai a year.

  12. Peracetic Acid as a Green Disinfectant for Combined Sewer ...

    Science.gov (United States)

    This cooperative research and development agreement between U.S. EPA, Solvay, MSDGC, and CB&I is evaluating the potential of PAA for disinfection of Muddy Creek CSO wastewater and comparing that with sodium hypochlorite disinfection. This presentation will document the effectiveness of sodium hypochlorite and PAA for the inactivation of E. coli in CSO wastewater using laboratory bench-scale jar tests and Muddy Creek field site studies based on the following items:•Storage, shelf life, and application of the disinfectants.•Effectiveness of the disinfectants in the inactivation of E. coli.•Formation of harmful byproducts by the disinfectants.•Operation and maintenance costs, including the cost of the disinfectant, its storage, application, and neutralizing agent for the disinfectant to maintain the Ohio EPA guideline for residual disinfectant at the discharge point. Like many cities in the USA, Cincinnati, Ohio is attempting to find the best way to meet state and federal requirements concerning combined sewer overflow (CSO) wastewater. The Muddy Creek CSO treatment facility was constructed to provide treatment for CSO Numbers 198 and 216 from the Westwood Trunk sewer. The Metropolitan Sewer District of Greater Cincinnati (MSDGC) is currently using sodium hypochlorite for disinfection in this treatment facility. Because of degradation of hypochlorite during storage and the formation of chlorinated disinfection byproducts (DBPs), MSDGC is evaluating alternat

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

    Science.gov (United States)

    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.

  14. Shift in the microbial ecology of a hospital hot water system following the introduction of an on-site monochloramine disinfection system.

    Science.gov (United States)

    Baron, Julianne L; Vikram, Amit; Duda, Scott; Stout, Janet E; Bibby, Kyle

    2014-01-01

    Drinking water distribution systems, including premise plumbing, contain a diverse microbiological community that may include opportunistic pathogens. On-site supplemental disinfection systems have been proposed as a control method for opportunistic pathogens in premise plumbing. The majority of on-site disinfection systems to date have been installed in hospitals due to the high concentration of opportunistic pathogen susceptible occupants. The installation of on-site supplemental disinfection systems in hospitals allows for evaluation of the impact of on-site disinfection systems on drinking water system microbial ecology prior to widespread application. This study evaluated the impact of supplemental monochloramine on the microbial ecology of a hospital's hot water system. Samples were taken three months and immediately prior to monochloramine treatment and monthly for the first six months of treatment, and all samples were subjected to high throughput Illumina 16S rRNA region sequencing. The microbial community composition of monochloramine treated samples was dramatically different than the baseline months. There was an immediate shift towards decreased relative abundance of Betaproteobacteria, and increased relative abundance of Firmicutes, Alphaproteobacteria, Gammaproteobacteria, Cyanobacteria and Actinobacteria. Following treatment, microbial populations grouped by sampling location rather than sampling time. Over the course of treatment the relative abundance of certain genera containing opportunistic pathogens and genera containing denitrifying bacteria increased. The results demonstrate the driving influence of supplemental disinfection on premise plumbing microbial ecology and suggest the value of further investigation into the overall effects of premise plumbing disinfection strategies on microbial ecology and not solely specific target microorganisms.

  15. Gamma irradiation of cultural artifacts for disinfection using Monte Carlo simulations

    International Nuclear Information System (INIS)

    Choi, Jong-il; Yoon, Minchul; Kim, Dongho

    2012-01-01

    In this study, it has been investigated the disinfection of Korean cultural artifacts by gamma irradiation, simulating the absorbed dose distribution on the object with the Monte Carlo methodology. Fungal contamination was identified on two traditional Korean agricultural tools, Hongdukkae and Holtae, which had been stored in a museum. Nine primary species were identified from these items: Bjerkandera adusta, Dothideomycetes sp., Penicillium sp., Cladosporium tenuissimum, Aspergillus versicolor, Penicillium sp., Entrophospora sp., Aspergillus sydowii, and Corynascus sepedonium. However, these fungi were completely inactivated by gamma irradiation at an absorbed dose of 20 kGy on the front side. Monte Carlo N Particle Transport Code was used to simulate the doses applied to these cultural artifacts, and the measured dose distributions were well predicted by the simulations. These results show that irradiation is effective for the disinfection of cultural artifacts and that dose distribution can be predicted with Monte Carlo simulations, allowing the optimization of the radiation treatment. - Highlights: ► Radiation was applied for the disinfection of Korean cultural artifacts. ► Fungi on the artifacts were completely inactivated by the irradiation. ► Monte Carlo N Particle Transport Code was used to predict the dose distribution. ► This study is applicable for the preservation of cultural artifacts by irradiation.

  16. Development of clean environment conservation technology by radiation

    International Nuclear Information System (INIS)

    Lee, Myunjoo; Kim, Tak Hyun; Jung, In Ha

    2012-04-01

    This report is aim to develop the technology for environmental conservation by radiation. It is consisted of two research parts. One is development of wastewater disinfection technology by radiation and the other is development of livestock waste treatment technology by radiation. For the development of wastewater disinfection technology disinfect ion process, technology for treatment of toxic organic chemicals and assessment of ecological toxicity, technology for treatment of endocrine disrupting chemicals and assessment of genetic safety were developed. For the development of livestock waste treatment technology, process for simultaneous removal of nutrients, technology for disinfection and quality enhancement of livestock waste compost, technology for reduction of composting periods, monitoring of toxic organic compounds, pretreatment technology for organic toxic chemicals and enhancement of biological treatment efficiencies were developed. Based on basic research, advanced livestock wastewater treatment process using radiation was established

  17. [Control of disinfection in buildings used for poultry raising].

    Science.gov (United States)

    Maris, P

    1989-01-01

    During a 2-year survey in turkey breeding farms, it was possible to compare six disinfection procedures by monitoring 14 first disinfections following the breeding house cleaning and 14 second disinfections prior to animal return. By swabbing all the germs from asbestos concrete surfaces, we noted that in the case of first disinfection the chloramine T-based product was more effective than phenol or quaternary ammonium-aldehyde-based products. For the second disinfection, it was demonstrated that a minimal dose of 15 kg of formaldehyde was necessary for disinfection to be satisfactory; 12 to 15 kg paraformaldehyde was as effective as 40 to 60 liters of 30-35% formol for buildings, the ground surface of which covered between 1,000 and 1,300 m2.

  18. Application and study of conjunctival sac disinfectants in ophthalmic surgeries

    Directory of Open Access Journals (Sweden)

    Yan-Fei Luo

    2016-01-01

    Full Text Available Postoperative endophthalmitis is the most serious complications of ophthalmic surgeries. Conjunctival sac disinfection is currently recognized as an effectively important way to reduce the risk of endophthalmitis. At present, there are some disinfectants has been used in clinic or in the researches:mercury agent, gentamicin, povidone iodine and acid electrolytic water. All kinds of disinfectants play the role of disinfection by different ways. Povidone iodine is the most widely used conjunctival sac disinfectant. Mercurial and gentamicin have been rarely used because they pollute the environment, are easy to cause drug resistant bacteria, localized side reactions and so on. The acid electrolyte water is not used in clinic at present. With the popularization and development of the ophthalmic surgeries, the ophthalmologists have become more and more concerned about the postoperative eye comfort, the research and application of conjunctival sac disinfectant in the future will continue to be updated and developed.

  19. Is free halogen necessary for disinfection?

    Science.gov (United States)

    Williams, D E; Elder, E D; Worley, S D

    1988-10-01

    The principle of Le Chatelier was used in demonstrating that 3-chloro-4,4-dimethyl-2-oxazolidinone (compound 1) itself kills Staphylococcus aureus rather than the very small amount of free chlorine in hydrolysis equilibrium with compound 1. On the other hand, when the N-bromo analog of compound 1 (compound 1B) was used as the disinfectant, the mixture of combined compound 1B and free bromine formed in the hydrolysis equilibrium provided disinfection. When the hydrolysis equilibrium for 1B was suppressed to the level at which a negligible amount of free bromine remained in solution, combined compound 1B was much more efficacious than combined compound 1 at killing S. aureus.

  20. Assessment of photoreactivation following ultraviolet light disinfection

    International Nuclear Information System (INIS)

    Kashimada, K.; Kamiko, N.; Yamamoto, K.; Ohgaki, S.

    1996-01-01

    Photoreactivation of microorganisms following UV disinfection is one of the research topics of interest in assessing the performance of UV disinfection, because there is little consensus on how the visible light intensity relates to the photoreactivation rate and the maximum survival in wastewater treatment processes. Apparent photoreactivation by a fluorescent lamp was observed in case of indicator bacteria (heterotrophic bacteria, coliform bacteria, fecal coliforms) in raw sewage, but not E. coli B and E. coli K12 A/λ(F+). Inactivation of fecal coliform was observed simultaneously during photoreactivation process by sunlight. Dose rate at 360 nm wave length as visible light intensity showed that it was a useful indicator for assessing the photoreactivation rate and the maximum survival when photoreactivation took place by both fluorescent lamp and sunlight. The model for photoreactivation was developed. The photoreactivation rate increased with increasing visible light intensity at 360 nm. However, the maximum survival value may not be affected by visible light intensity. (author)

  1. UV DISINFECTION GUIDANCE MANUAL FOR THE ...

    Science.gov (United States)

    Provides technical information on selection, design and operation of UV systems; provides regulatory agencies with guidance and the necessary tools to assess UV systems at the design, start-up, and routine operation phase; provides manufacturers with the testing and performance standards for UV components and systems for treating drinking water. Provide guidance to water systems, regulators and manufacturers on UV disinfection of drinking water.

  2. Role of disinfection in the Infection Prevention Multibarrier System

    OpenAIRE

    Kramer, Axel

    2007-01-01

    The role of disinfection in infection prevention has been analyzed over the past 50 years both in the form of benefit-risk evaluations as well as in an epidemiological sense. This has served as the basis for not only national and international guidelines and recommendations, but has also created the legal and normative framework for regulation of infection control (and hence of disinfection) in numerous and acts and ordinances. Likewise, today the efficacy of disinfection measures, user safet...

  3. Disinfectant effect of Methylated Ethanol against Listeria species

    OpenAIRE

    Y Yakubu; M D Salihu; O O Faleke; M B Abubakar; A A Magaji,A U Junaidu

    2012-01-01

    This study was carried out in order to determine the disinfectant effect of Methylated spirit® (95% methanol and 5% ethanol) as a teat dip against Listeria species. Hand milking was employed to collect 576 (288 x 2) raw milk samples from different lactating cows within Sokoto metropolis (Nigeria). 288 samples were collected before disinfecting the udder teats with Methylated spirit®, while the other 288 were collected after disinfection with Methylated spirit®. The ...

  4. Efficacy of a variety of disinfectants against Listeria spp.

    OpenAIRE

    Best, M; Kennedy, M E; Coates, F

    1990-01-01

    The efficacy of 14 disinfectants against Listeria innocua and two strains of Listeria monocytogenes in the presence of organic matter was studied. Quantitative efficacy tests were used. Many of the disinfectants tested were not as effective on Listeria spp. when the test organisms were dried onto the surface of steel disks (carrier tests) as they were when the organisms were placed in suspension (suspension test). The presence of whole serum and milk (2% fat) further reduced the disinfectant ...

  5. Bacterial Spores Survive Treatment with Commercial Sterilants and Disinfectants

    OpenAIRE

    Sagripanti, Jose-Luis; Bonifacino, Aylin

    1999-01-01

    This study compared the activity of commercial liquid sterilants and disinfectants on Bacillus subtilis spores deposited on three types of devices made of noncorrodible, corrodible, or polymeric material. Products like Renalin, Exspor, Wavicide-01, Cidexplus, and cupric ascorbate were tested under conditions specified for liquid sterilization. These products, at the shorter times indicated for disinfection, and popular disinfectants, like Clorox, Cavicide, and Lysol were also studied. Data ob...

  6. Environmental radiation studies relevant to thermoluminescence dating

    International Nuclear Information System (INIS)

    Murray, A.S.; Bowman, S.G.E.; Aitken, M.J.

    1980-01-01

    To determine the age of a potsherd by the thermoluminescence (TL) technique, one must have an accurate knowledge of the cosmic and environmental gamma dose rate in quartz. This is obtained by leaving a sensitive TL dosimeter buried as near as possible to the position from which the sherd was removed. The ratios of the response of a quartz-like dosimeter to those of CaF 2 and LiF have been measured. This experiment used a 1-m cube of concrete containing 3000 ppM of uranium and its daughters. Smaller, less active matrixes of 40 K and thorium and its daughters have also been constructed. A means of making direct dose-rate determinations when the site context remains but burial of a dosimeter is impractical was developed using a NaI(Tl) system. The equipment was field tested on approx. 40 Peruvian archaeological sites, and results are compared with CaF 2 measurements

  7. Spiral-shaped reactor for water disinfection

    KAUST Repository

    Soukane, Sofiane

    2016-04-20

    Chlorine-based processes are still widely used for water disinfection. The disinfection process for municipal water consumption is usually carried out in large tanks, specifically designed to verify several hydraulic and disinfection criteria. The hydrodynamic behavior of contact tanks of different shapes, each with an approximate total volume of 50,000 m3, was analyzed by solving turbulent momentum transport equations with a computational fluid dynamics code, namely ANSYS fluent. Numerical experiments of a tracer pulse were performed for each design to generate flow through curves and investigate species residence time distribution for different inlet flow rates, ranging from 3 to 12 m3 s−1. A new nature-inspired Conch tank design whose shape follows an Archimedean spiral was then developed. The spiral design is shown to strongly outperform the other tanks’ designs for all the selected plug flow criteria with an enhancement in efficiency, less short circuiting, and an order of magnitude improvement in mixing and dispersion. Moreover, following the intensification philosophy, after 50% reduction in its size, the new design retains its properties and still gives far better results than the classical shapes.

  8. Biological Treatment of Water Disinfection Byproducts using ...

    Science.gov (United States)

    Major disinfection by-products (DBPs) from the chlorination process of drinking water include trihalomethanes (THMs) and haloacetic acides (HAA5). THMs mainly consist of chloroform, and other harsh chemicals. Prolonged consumptions of drinking water containing high levels of THMs has been linked with diseases of the liver, kidneys, bladder, or central nervous system and may increase likelihood of cancer. A risk also exists for THMs exposure via inhalation while showering, bathing or washing clothes and dishes. Due to these risks, the U.S. EPA regulate THMs content in drinking water. This research investigates biological degradation of THM using chloroform as a model compound. The study aims to decrease possible risks of THMs through filtration. Throughout this year’s presentations, there is a common theme of health and safety concerns. UC researchers are working hard to clean water ways of naturally occurring contaminates as well as man-made toxins found in our waterways. The significance of these presentations translates into the promise of safer environments, and more importantly saved lives, as UC’s faculty continues to produce real-world solutions to problems threatening the world around us. A biotech process has been developed and demonstrated that effectively remove and treat volatile disinfection by-products from drinking water. The process strips low concentration disinfection by-products, such as trihalomethanes, that are formed during the chlori

  9. Evaluation of toothbrush disinfection via different methods

    Directory of Open Access Journals (Sweden)

    Adil BASMAN

    2016-01-01

    Full Text Available The aim of this study was to compare the efficacy of using a dishwasher or different chemical agents, including 0.12% chlorhexidine gluconate, 2% sodium hypochlorite (NaOCl, a mouthrinse containing essential oils and alcohol, and 50% white vinegar, for toothbrush disinfection. Sixty volunteers were divided into five experimental groups and one control group (n = 10. Participants brushed their teeth using toothbrushes with standard bristles, and they disinfected the toothbrushes according to instructed methods. Bacterial contamination of the toothbrushes was compared between the experimental groups and the control group. Data were analyzed by Kruskal–Wallis and Duncan's multiple range tests, with 95% confidence intervals for multiple comparisons. Bacterial contamination of toothbrushes from individuals in the experimental groups differed from those in the control group (p < 0.05. The most effective method for elimination of all tested bacterial species was 50% white vinegar, followed in order by 2% NaOCl, mouthrinse containing essential oils and alcohol, 0.12% chlorhexidine gluconate, dishwasher use, and tap water (control. The results of this study show that the most effective method for disinfecting toothbrushes was submersion in 50% white vinegar, which is cost-effective, easy to access, and appropriate for household use.

  10. Models for predicting disinfection byproduct (DBP) formation in drinking waters: a chronological review.

    Science.gov (United States)

    Chowdhury, Shakhawat; Champagne, Pascale; McLellan, P James

    2009-07-01

    Disinfection for the supply of safe drinking water forms a variety of known and unknown byproducts through reactions between the disinfectants and natural organic matter. Chronic exposure to disinfection byproducts through the ingestion of drinking water, inhalation and dermal contact during regular indoor activities (e.g., showering, bathing, cooking) may pose cancer and non-cancer risks to human health. Since their discovery in drinking water in 1974, numerous studies have presented models to predict DBP formation in drinking water. To date, more than 48 scientific publications have reported 118 models to predict DBP formation in drinking waters. These models were developed through laboratory and field-scale experiments using raw, pretreated and synthetic waters. This paper aims to review DBP predictive models, analyze the model variables, assess the model advantages and limitations, and to determine their applicability to different water supply systems. The paper identifies the current challenges and future research needs to better control DBP formation. Finally, important directions for future research are recommended to protect human health and to follow the best management practices.

  11. Bacterial spores survive treatment with commercial sterilants and disinfectants.

    Science.gov (United States)

    Sagripanti, J L; Bonifacino, A

    1999-09-01

    This study compared the activity of commercial liquid sterilants and disinfectants on Bacillus subtilis spores deposited on three types of devices made of noncorrodible, corrodible, or polymeric material. Products like Renalin, Exspor, Wavicide-01, Cidexplus, and cupric ascorbate were tested under conditions specified for liquid sterilization. These products, at the shorter times indicated for disinfection, and popular disinfectants, like Clorox, Cavicide, and Lysol were also studied. Data obtained with a sensitive and quantitative test suggest that commercial liquid sterilants and disinfectants are less effective on contaminated surfaces than generally acknowledged.

  12. Correlates of minimal dating.

    Science.gov (United States)

    Leck, Kira

    2006-10-01

    Researchers have associated minimal dating with numerous factors. The present author tested shyness, introversion, physical attractiveness, performance evaluation, anxiety, social skill, social self-esteem, and loneliness to determine the nature of their relationships with 2 measures of self-reported minimal dating in a sample of 175 college students. For women, shyness, introversion, physical attractiveness, self-rated anxiety, social self-esteem, and loneliness correlated with 1 or both measures of minimal dating. For men, physical attractiveness, observer-rated social skill, social self-esteem, and loneliness correlated with 1 or both measures of minimal dating. The patterns of relationships were not identical for the 2 indicators of minimal dating, indicating the possibility that minimal dating is not a single construct as researchers previously believed. The present author discussed implications and suggestions for future researchers.

  13. Dating of cremated bones

    OpenAIRE

    Lanting, JN; Aerts-Bijma, AT; van der Plicht, J; Boaretto, E.; Carmi, I.

    2001-01-01

    When dating unburnt bone, bone collagen, the organic fraction of the bone, is used. Collagen does not survive the heat of the cremation pyre, so dating of cremated bone has been considered impossible. Structural carbonate in the mineral fraction of the bone, however, survives the cremation process. We developed a method of dating cremated bone by accelerator mass spectrometry (AMS), using this carbonate fraction. Here we present results for a variety of prehistoric sites and ages, showing a r...

  14. Carbon 14 dating method

    International Nuclear Information System (INIS)

    Fortin, Ph.

    2000-01-01

    This document gives a first introduction to 14 C dating as it is put into practice at the radiocarbon dating centre of Claude-Bernard university (Lyon-1 univ., Villeurbanne, France): general considerations and recalls of nuclear physics; the 14 C dating method; the initial standard activity; the isotopic fractioning; the measurement of samples activity; the liquid-scintillation counters; the calibration and correction of 14 C dates; the preparation of samples; the benzene synthesis; the current applications of the method. (J.S.)

  15. Less skin irritation from alcohol-based disinfectant than from detergent used for hand disinfection

    DEFF Research Database (Denmark)

    Pedersen, L K; Held, E; Johansen, J D

    2005-01-01

    and forearms of 17 healthy volunteers. A control area was included. After 4 weeks an SLS patch was applied to each area. Irritant reactions were quantified with a visual score recording and measurements of transepidermal water loss (TEWL) and skin colour were performed on days 1, 5, 11, 38 and 40. RESULTS...... was found on the disinfectant-treated area compared with the control area and detergent area, and a similar trend was found for TEWL, although it was not statistically significant. CONCLUSION: Alcohol-based disinfectant caused less visible skin irritation and less skin barrier disruption than the use...

  16. Evaluation of the efficiency of the photo Fenton disinfection of natural drinking water source during the rainy season in the Sahelian region

    International Nuclear Information System (INIS)

    Ndounla, J.; Pulgarin, C.

    2014-01-01

    The photo-disinfection of water from two different wells (W1, pH: 4.6–5.1 ± 0.02) and (W2 pH: 5.6–5.7 ± 0.02) was carried out during the rainy season at Ouagadougou–Burkina Faso, West Africa. The weather variation during the rainy season significantly affects the photo-disinfection processes (solar disinfection and photo-Fenton). The dilution of the water by rainwater highly affected the chemical composition of the wells' water used in this study; very low iron contents Compared to the ones recorded during the dry season were recorded in all water samples. Both photo-disinfection processes were used to treat 25 L of water in a compound parabolic collector (CPC). None of them have shown the total inactivation of both wild enteric bacteria strains (total coliforms/E. coli and Salmonella spp.) involved in the treatment. However, the total coliforms/E. coli strains were totally inactivated during the exposure under most of the photo-Fenton treatment. Also, the remaining strains, especially those of Salmonella spp. were achieved during the subsequent 24 h of dark storage under the action of the Fenton process. Under uniquely solar radiation, total inactivation was recorded only in the total coliforms/E. coli strains. The impact of the available irradiance on the efficiency of the photo-Fenton disinfection of natural water was highlighted during the exposure under high intermittent solar radiation. The impact of the HCO 3 − concentration of both wells' water on the evolution of the pH during the photo-disinfection was recorded. Drastic decrease was noticed after the initial fast increase in presence of low HCO 3 − concentration while a steady state was observed after the increase in presence of higher concentration. The redox activities of the nitrogen components of the water during both photo-disinfection processes have led to increased concentration of nitrite in all the cases and variations were noticed in that of nitrate and ammonia. - Graphical

  17. Evaluation of the efficiency of the photo Fenton disinfection of natural drinking water source during the rainy season in the Sahelian region

    Energy Technology Data Exchange (ETDEWEB)

    Ndounla, J., E-mail: juliette.ndounla@epfl.ch [Ecole Polytechnique Fédérale de Lausanne, Institute of Chemical Sciences and Engineering GPAO, Station 6, CH 1015 Lausanne (Switzerland); Institut International d' Ingénierie de l' Eau et de l' Environnement, Laboratoire Eau, Dépollution, Ecosystème et Santé (LEDES), 01 BP 594 Ouagadougou 01 (Burkina Faso); Pulgarin, C., E-mail: Cesar.pulgarin@epfl.ch [Ecole Polytechnique Fédérale de Lausanne, Institute of Chemical Sciences and Engineering GPAO, Station 6, CH 1015 Lausanne (Switzerland)

    2014-09-15

    The photo-disinfection of water from two different wells (W1, pH: 4.6–5.1 ± 0.02) and (W2 pH: 5.6–5.7 ± 0.02) was carried out during the rainy season at Ouagadougou–Burkina Faso, West Africa. The weather variation during the rainy season significantly affects the photo-disinfection processes (solar disinfection and photo-Fenton). The dilution of the water by rainwater highly affected the chemical composition of the wells' water used in this study; very low iron contents Compared to the ones recorded during the dry season were recorded in all water samples. Both photo-disinfection processes were used to treat 25 L of water in a compound parabolic collector (CPC). None of them have shown the total inactivation of both wild enteric bacteria strains (total coliforms/E. coli and Salmonella spp.) involved in the treatment. However, the total coliforms/E. coli strains were totally inactivated during the exposure under most of the photo-Fenton treatment. Also, the remaining strains, especially those of Salmonella spp. were achieved during the subsequent 24 h of dark storage under the action of the Fenton process. Under uniquely solar radiation, total inactivation was recorded only in the total coliforms/E. coli strains. The impact of the available irradiance on the efficiency of the photo-Fenton disinfection of natural water was highlighted during the exposure under high intermittent solar radiation. The impact of the HCO{sub 3}{sup −} concentration of both wells' water on the evolution of the pH during the photo-disinfection was recorded. Drastic decrease was noticed after the initial fast increase in presence of low HCO{sub 3}{sup −} concentration while a steady state was observed after the increase in presence of higher concentration. The redox activities of the nitrogen components of the water during both photo-disinfection processes have led to increased concentration of nitrite in all the cases and variations were noticed in that of nitrate and

  18. S K Date

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. S K Date. Articles written in Bulletin of Materials Science. Volume 23 Issue 2 April 2000 pp 97-101 Magnetic Materials. Comparison of the irreversible thermomagnetic behaviour of some ferro- and ferrimagnetic systems · P S Anil Kumar P A Joy S K Date · More Details Abstract ...

  19. Second Quaternary dating workshop

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-11-01

    The second Quaternary dating methods workshop was held at Lucas Heights and sponsored by ANSTO and AINSE. Topics covered include, isotope and thermoluminescence dating, usage of accelerator and thermal ionisation mass spectrometry in environmental studies emphasizing on the methodologies used and sample preparation

  20. Dating of cremated bones

    NARCIS (Netherlands)

    Lanting, JN; Aerts-Bijma, AT; van der Plicht, J; Boaretto, E.; Carmi, I.

    2001-01-01

    When dating unburnt bone, bone collagen, the organic fraction of the bone, is used. Collagen does not survive the heat of the cremation pyre, so dating of cremated bone has been considered impossible. Structural carbonate in the mineral fraction of the bone, however, survives the cremation process.

  1. Second Quaternary dating workshop

    International Nuclear Information System (INIS)

    1999-01-01

    The second Quaternary dating methods workshop was held at Lucas Heights and sponsored by ANSTO and AINSE. Topics covered include, isotope and thermoluminescence dating, usage of accelerator and thermal ionisation mass spectrometry in environmental studies emphasizing on the methodologies used and sample preparation

  2. Radiation sterilization of harmful algae in water

    International Nuclear Information System (INIS)

    Byung Chull An; Jae-Sung Kim; Seung Sik Lee; Shyamkumar Barampuram; Eun Mi Lee; Byung Yeoup Chung

    2007-01-01

    Complete text of publication follows. Objective: Drinking water, water used in food production and for irrigation, water for fish farming, waste water, surface water, and recreational water have been recently recognized as a vector for the transmission of harmful micro-organisms. The human and animal harmful algae is a waterborne risk to public health and economy because the algae are ubiquitous and persistent in water and wastewater, not completely removed by physical-chemical treatment processes, and relatively resistant to chemical disinfection. Gamma and electron beam radiation technology is of growing in the water industry since it was demonstrated that gamma and electron beam radiation is very effective against harmful algae. Materials and Methods: Harmful algae (Scenedesmus quadricauda(Turpin) Brebisson 1835 (AG10003), Chlorella vulgaris Beijerinck 1896 (AG30007) and Chlamydomonas sp. (AG10061)) were distributed from Korean collection for type cultures (KCTC). Strains were cultured aerobically in Allen's medium at 25□ and 300 umol/m2s for 1 week using bioreactor. We investigated the disinfection efficiency of harmful algae irradiated with gamma (0.05 to 10 kGy for 30 min) and electron beam (1 to 19 kGy for 5 sec) rays. Results and Conclusion: We investigated the disinfection efficiency of harmful algae irradiated with gamma and electron beam rays of 50 to 19000 Gy. We established the optimum sterilization condition which use the gamma and electron beam radiation. Gamma ray disinfected harmful algae at 400 Gy for 30 min. Also, electron beam disinfected at 1000 Gy for 5 sec. This alternative disinfection practice had powerful disinfection efficiency. Hence, the multi-barrier approach for drinking water treatment in which a combination of various disinfectants and filtration technologies are applied for removal and inactivation of different microbial pathogens will guarantee a lower risk of microbial contamination.

  3. Quaternary dating methods

    International Nuclear Information System (INIS)

    Mahaney, W.C.

    1984-01-01

    The papers in this book cover absolute, relative and multiple dating methods, and have been written by specialists from a number of different earth sciences disciplines - their common interest being the dating of geological materials within the Quaternary. Papers on absolute dating methods discuss radiocarbon, uranium-series, potassium argon, 40 Ar/ 39 Ar, paleomagnetic, obsidian hydration, thermoluminescence, amino acid racemization, tree rings, and lichenometric techniques. Those on relative dating include discussions on various geomorphic relative age indicators such as drainage density changes, hypsometric integrals, bifurcation ratios, stream junction angles, spur morphology, hillslope geometry, and till sheet characteristics. The papers on multiple dating cite examples from the Rocky Mountains, Australia, Lake Agassiz Basin, and the Southern Andes. Also included is the panel discussion which reviews and assesses the information presented, and a field trip guide which discusses the sequences of Wisconian tills and interlayered lacustrine and fluvial sediments. (orig.)

  4. Disinfection of drinking water by ultraviolet light. Minimum dose and shortest time of residence are central criteria when choosing plant

    Energy Technology Data Exchange (ETDEWEB)

    1977-06-23

    It is no longer mandatory that a given residue of chlorine is present in drinking water and this has led to interest in the use of ultraviolet radiation for disinfection of water in large public waterworks. After a brief discussion of the effect of ultraviolet radiation related to wavelength, the most usual type of irradiation equipment is briefly described. Practioal considerations regarding the installation, such as attenuation of the radiation due to water quality and deposits are presented. The requirements as to dose and residence time are also discussed and finally it is pointed out that hydraulic imperfections can reduce the effectiveness drastically.

  5. MUTAGENICITY AND DISINFECTION BY-PRODUCTS IN SURFACE DRINKING WATER DISINFECTED WITH PERACETIC ACID

    Science.gov (United States)

    The aims of this research were to study the influence of peracetic acid (PAA) on the formation of mutagens in surface waters used for human consumption and to assess its potential application for the disinfection of drinking water. The results obtained using PAA were compared to ...

  6. ESR dating of fault rocks

    International Nuclear Information System (INIS)

    Lee, Hee Kwon

    2003-02-01

    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then grow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs. grain size shows a plateau for grains below critical size; these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected near the Gori nuclear reactor. Most of the ESR signals of fault rocks collected from the basement are saturated. This indicates that the last movement of the faults had occurred before the Quaternary period. However, ESR dates from the Oyong fault zone range from 370 to 310 ka. Results of this research suggest that long-term cyclic fault activity of the Oyong fault zone continued into the Pleistocene

  7. ESR dating of fault rocks

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Kwon [Kangwon National Univ., Chuncheon (Korea, Republic of)

    2003-02-15

    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then grow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs. grain size shows a plateau for grains below critical size; these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected near the Gori nuclear reactor. Most of the ESR signals of fault rocks collected from the basement are saturated. This indicates that the last movement of the faults had occurred before the Quaternary period. However, ESR dates from the Oyong fault zone range from 370 to 310 ka. Results of this research suggest that long-term cyclic fault activity of the Oyong fault zone continued into the Pleistocene.

  8. 21 CFR 880.6890 - General purpose disinfectants.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use... disinfectant is a germicide intended to process noncritical medical devices and equipment surfaces. A general... prior to terminal sterilization or high level disinfection. Noncritical medical devices make only...

  9. [Scanning electron microscope study of chemically disinfected endodontic files].

    Science.gov (United States)

    Navarro, G; Mateos, M; Navarro, J L; Canalda, C

    1991-01-01

    Forty stainless steel endodontic files were observed at scanning electron microscopy after being subjected to ten disinfection cycles of 10 minutes each one, immersed in different chemical disinfectants. Corrosion was not observed on the surface of the files in circumstances that this study was made.

  10. Ozone reactions with indoor materials during building disinfection

    DEFF Research Database (Denmark)

    Poppendieck, D.; Hubbard, H.; Ward, M.

    2007-01-01

    , and particularly after several hours of disinfection, surface reaction resistance dominated the overall resistance to ozone deposition for nearly all materials. Total building disinfection by-products (all carbonyls) were quantified per unit area of each material for the experimental period. Paper, office...... partition, and medium density fiberboard each released greater than 38 mg m(-2) of by-products....

  11. The antimicrobial activities of some commonly used disinfectants on ...

    African Journals Online (AJOL)

    The disinfectants; SavlonR, JikR, Methylated spirit and kerosene were observed for their inhibitory activities on Bacillus subtilis, Pseudomonas aeruginosa and Candida albicans. This was done by measuring the zone of inhibition of the disinfectants on the tested organisms. The results showed that Savlon was very effective ...

  12. Microbial contamination of disinfectant solutions in some health care ...

    African Journals Online (AJOL)

    Commonly used disinfectants in some health institutions in three major towns of northern Nigeria were examined for presence of bacteria contamination. For each disinfectant, stock, freshly diluted and left-over of used diluted samples were analyzed. All the stock samples were free of bacteria contaminants while 52.17% of ...

  13. HIGH-RATE DISINFECTION TECHNIQUES FOR COMBIND SEWER OVERFLOW

    Science.gov (United States)

    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 )...

  14. Peracetic Acid as a Green Disinfectant for Combined Sewer Overflows

    Science.gov (United States)

    This cooperative research and development agreement between U.S. EPA, Solvay, MSDGC, and CB&I is evaluating the potential of PAA for disinfection of Muddy Creek CSO wastewater and comparing that with sodium hypochlorite disinfection. This presentation will document the effectiven...

  15. Disinfectant effect of Methylated Ethanol against Listeria species

    Directory of Open Access Journals (Sweden)

    Y Yakubu

    2012-04-01

    Full Text Available This study was carried out in order to determine the disinfectant effect of Methylated spirit® (95% methanol and 5% ethanol as a teat dip against Listeria species. Hand milking was employed to collect 576 (288 x 2 raw milk samples from different lactating cows within Sokoto metropolis (Nigeria. 288 samples were collected before disinfecting the udder teats with Methylated spirit®, while the other 288 were collected after disinfection with Methylated spirit®. The samples were analyzed using selective culture and isolation technique in which the 288 samples collected before disinfection, 114 (39.6% were positive for Listeria species. Among the positive samples 44 (38.6% were Listeria innocua, 16 (14.0% Listeria ivanovii, 36 (31.6% Listeria monocytogenes, 11 (9.6% Listeria welshimeri and 7 (6.1% Listeria seeligeri, while none of the 288 samples collected after disinfection was positive. The study has shown high prevalence of Listeria species in milk collected without washing/disinfecting the teats and has also established the sensitivity of Listeria species to methylated ethanol which can be used as dip for disinfecting udder teats before milking in order to prevent contamination with Listeria species and other methylated spirit-sensitive organisms. This study is essential to educate Fulani herdsmen and other milk handlers on the importance of disinfecting udder teats before milking. [Vet. World 2012; 5(2.000: 91-93

  16. Evaluation of hospital disinfection as a means of controlling endemic ...

    African Journals Online (AJOL)

    Evaluation of hospital environment disinfection as a means of controlling endemic nosocomial pathogens in a University Teaching Hospital in Nigeria was evaluated. Disinfectant used in the Hospital was collected from the Infection Control unit and prepared in different concentrations. The isolated bacterial species from the ...

  17. Nanomaterial Case Study: Nanoscale Silver in Disinfectant Spray (Final Report)

    Science.gov (United States)

    EPA announced the release of the final report, Nanomaterial Case Study: Nanoscale Silver in Disinfectant Spray. This report represents a case study of engineered nanoscale silver (nano-Ag), focusing on the specific example of nano-Ag as possibly used in disinfectant spr...

  18. Disinfection studies of Nahar (Mesua ferrea) seed kernel oil using ...

    African Journals Online (AJOL)

    GREGORY

    2011-12-16

    Dec 16, 2011 ... with a k value of -0.040. Key words: Nahar (Mesua ferrea) seed kernel oil, extraction, gum Arabic, disinfection, kinetics. INTRODUCTION. Disinfection plays a key role in the reclamation and reuse of wastewater for eliminating infectious diseases, this, in part, augments domestic water supply and decreases ...

  19. Candida auris: Disinfectants and Implications for Infection Control.

    Science.gov (United States)

    Ku, Tsun S N; Walraven, Carla J; Lee, Samuel A

    2018-01-01

    Candida auris is a rapidly emerging pathogen and is able to cause severe infections with high mortality rates. It is frequently misidentified in most clinical laboratories, thus requiring more specialized identification techniques. Furthermore, several clinical isolates have been found to be multidrug resistant and there is evidence of nosocomial transmission in outbreak fashion. Appropriate infection control measures will play a major role in controlling the management and spread of this pathogen. Unfortunately, there are very few data available on the effectiveness of disinfectants against C. auris . Chlorine-based products appear to be the most effective for environmental surface disinfection. Other disinfectants, although less effective than chlorine-based products, may have a role as adjunctive disinfectants. A cleaning protocol will also need to be established as the use of disinfectants alone may not be sufficient for maximal decontamination of patient care areas. Furthermore, there are fewer data on the effectiveness of antiseptics against C. auris for patient decolonization and hand hygiene for healthcare personnel. Chlorhexidine gluconate has shown some efficacy in in vitro studies but there are reports of patients with persistent colonization despite twice daily body washes with this disinfectant. Hand hygiene using soap and water, with or without chlorhexidine gluconate, may require the subsequent use of alcohol-based hand sanitizer for maximal disinfection. Further studies will be needed to validate the currently studied disinfectants for use in real-world settings.

  20. Candida auris: Disinfectants and Implications for Infection Control

    Directory of Open Access Journals (Sweden)

    Tsun S. N. Ku

    2018-04-01

    Full Text Available Candida auris is a rapidly emerging pathogen and is able to cause severe infections with high mortality rates. It is frequently misidentified in most clinical laboratories, thus requiring more specialized identification techniques. Furthermore, several clinical isolates have been found to be multidrug resistant and there is evidence of nosocomial transmission in outbreak fashion. Appropriate infection control measures will play a major role in controlling the management and spread of this pathogen. Unfortunately, there are very few data available on the effectiveness of disinfectants against C. auris. Chlorine-based products appear to be the most effective for environmental surface disinfection. Other disinfectants, although less effective than chlorine-based products, may have a role as adjunctive disinfectants. A cleaning protocol will also need to be established as the use of disinfectants alone may not be sufficient for maximal decontamination of patient care areas. Furthermore, there are fewer data on the effectiveness of antiseptics against C. auris for patient decolonization and hand hygiene for healthcare personnel. Chlorhexidine gluconate has shown some efficacy in in vitro studies but there are reports of patients with persistent colonization despite twice daily body washes with this disinfectant. Hand hygiene using soap and water, with or without chlorhexidine gluconate, may require the subsequent use of alcohol-based hand sanitizer for maximal disinfection. Further studies will be needed to validate the currently studied disinfectants for use in real-world settings.

  1. Sewage disinfection towards protection of drinking water resources.

    Science.gov (United States)

    Kolch, A

    2000-01-01

    Wastewater applied in agriculture for irrigation could replace the use of natural drinking-water resources. With respect to high concentrations of human pathogens wastewater has to be disinfected prior to use. This paper introduces disinfection methods with emphasis on UV irradiation.

  2. Endoscope disinfection and its pitfalls - requirement for retrograde surveillance cultures

    NARCIS (Netherlands)

    Buss, A. J.; Been, M. H.; Borgers, R. P.; Stokroos, I.; Melchers, W. J. G.; Peters, F. T. M.; Limburg, A. J.; Degener, J. E.

    Background and study aims: Several endoscopy-related outbreaks of infection have been reported in recent years. For early recognition of inadequate disinfection of endoscopes we designed a microbiological surveillance system to evaluate the efficacy of the cleaning and disinfection procedure, and to

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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

  5. Disinfection of contaminated water by using solar irradiation.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2013-01-01

    Drinking water is the most important single source of human exposure to gastroenteric diseases, mainly as a result of the ingestion of microbial contaminated water. Waterborne microbial agents that pose a health risk to humans include enteropathogenic bacteria, viruses, and protozoa. Therefore, properly assessing whether these hazardous agents enter drinking water supplies, and if they do, whether they are disinfected adequately, are undoubtedly aspects critical to protecting public health. As new pathogens emerge, monitoring for relevant indicator microorganisms (e.g., process microbial indicators, fecal indicators, and index and model organisms) is crucial to ensuring drinking water safety. Another crucially important step to maintaining public health is implementing Water Safety Plans (WSPs), as is recommended by the current WHO Guidelines for Drinking Water Quality. Good WSPs include creating health-based targets that aim to reduce microbial risks and adverse health effects to which a population is exposed through drinking water. The use of disinfectants to inactivate microbial pathogens in drinking water has played a central role in reducing the incidence of waterborne diseases and is considered to be among the most successful interventions for preserving and promoting public health. Chlorine-based disinfectants are the most commonly used disinfectants and are cheap and easy to use. Free chlorine is an effective disinfectant for bacteria and viruses; however, it is not always effective against C. parvum and G. lamblia. Another limitation of using chlorination is that it produces disinfection by-products (DBPs), which pose potential health risks of their own. Currently, most drinking water regulations aggressively address DBP problems in public water distribution systems. The DBPs of most concern include the trihalomethanes (THMs), the haloacetic acids (HAAs), bromate, and chlorite. However, in the latest edition of the WHO Guidelines for Drinking Water Quality

  7. Impact of disinfection on drinking water biofilm bacterial community.

    Science.gov (United States)

    Mi, Zilong; Dai, Yu; Xie, Shuguang; Chen, Chao; Zhang, Xiaojian

    2015-11-01

    Disinfectants are commonly applied to control the growth of microorganisms in drinking water distribution systems. However, the effect of disinfection on drinking water microbial community remains poorly understood. The present study investigated the impacts of different disinfectants (chlorine and chloramine) and dosages on biofilm bacterial community in bench-scale pipe section reactors. Illumina MiSeq sequencing illustrated that disinfection strategy could affect both bacterial diversity and community structure of drinking water biofilm. Proteobacteria tended to predominate in chloraminated drinking water biofilms, while Firmicutes in chlorinated and unchlorinated biofilms. The major proteobacterial groups were influenced by both disinfectant type and dosage. In addition, chloramination had a more profound impact on bacterial community than chlorination. Copyright © 2015. Published by Elsevier B.V.

  8. Date Rape (For Teens)

    Science.gov (United States)

    ... owe" someone sex, even if you're a couple. Rape is not always violent. If you say " ... date rape" drugs like: rohypnol , called roofies, lunch money, or mind erasers GHB (gamma hydroxybutyric acid), called ...

  9. Methods of dating

    Energy Technology Data Exchange (ETDEWEB)

    Gatty, B

    1986-04-01

    Scientific methods of dating, born less than thirty years ago, have recently improved tremendously. First the dating principles will be given; then it will be explained how, through natural radioactivity, we can have access to the age of an event or an object; the case of radiocarbon will be especially emphasized. The principle of relative methods such as thermoluminescence or paleomagnetism will also be shortly given. What is the use for dating. The fields of its application are numerous; through these methods, relatively precise ages can be given to the major events which have been keys in the history of universe, life and man; thus, dating is a useful scientific tool in astrophysics, geology, biology, anthropology and archeology. Even if certain ages are still subject to controversies, we can say that these methods have confirmed evolution's continuity, be it on a cosmic, biologic or human scale, where ages are measured in billions, millions or thousands of years respectively.

  10. Radiometric dating methods

    International Nuclear Information System (INIS)

    Bourdon, B.

    2003-01-01

    The general principle of isotope dating methods is based on the presence of radioactive isotopes in the geologic or archaeological object to be dated. The decay with time of these isotopes is used to determine the 'zero' time corresponding to the event to be dated. This paper recalls the general principle of isotope dating methods (bases, analytical methods, validation of results and uncertainties) and presents the methods based on natural radioactivity (Rb-Sr, Sm-Nd, U-Pb, Re-Os, K-Ar (Ar-Ar), U-Th-Ra- 210 Pb, U-Pa, 14 C, 36 Cl, 10 Be) and the methods based on artificial radioactivity with their applications. Finally, the methods based on irradiation damages (thermoluminescence, fission tracks, electron spin resonance) are briefly evoked. (J.S.)

  11. NAIP 2012 Image Dates

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — This map is produced by the Aerial Phtography Field Office (APFO) to show the image acquisition dates for the 2012 National Agriculture Imagery Program (NAIP)...

  12. NAIP 2014 Image Dates

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — This map is produced by the Aerial Phtography Field Office (APFO) to show the image acquisition dates for the 2014 National Agriculture Imagery Program (NAIP)...

  13. Food Product Dating

    Science.gov (United States)

    ... Standard Forms FSIS United States Department of Agriculture Food Safety and Inspection Service About FSIS District Offices ... Web Content Viewer (JSR 286) Actions ${title} Loading... Food Product Dating "Best if Used By" is a ...

  14. NAIP 2013 Image Dates

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — This map is produced by the Aerial Phtography Field Office (APFO) to show the image acquisition dates for the 2013 National Agriculture Imagery Program (NAIP)...

  15. NAIP 2011 Image Dates

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — This map is produced by the Aerial Phtography Field Office (APFO) to show the image acquisition dates for the 2011 National Agriculture Imagery Program (NAIP)...

  16. The role of surface disinfection in infection prevention

    Science.gov (United States)

    Gebel, Jürgen; Exner, Martin; French, Gary; Chartier, Yves; Christiansen, Bärbel; Gemein, Stefanie; Goroncy-Bermes, Peter; Hartemann, Philippe; Heudorf, Ursel; Kramer, Axel; Maillard, Jean-Yves; Oltmanns, Peter; Rotter, Manfred; Sonntag, Hans-Günther

    2013-01-01

    Background: The Rudolf Schuelke Foundation addresses topics related to hygiene, infection prevention and public health. In this context a panel of scientists from various European countries discussed “The Role of Surface Disinfection in Infection Prevention”. The most important findings and conclusions of this meeting are summarised in the present consensus paper. Aim: Although the relevance of surface disinfection is increasingly being accepted, there are still a number of issues which remain controversial. In particular, the following topics were addressed: Transferral of microbes from surface to patients as a cause of infection, requirements for surface disinfectants, biocidal resistance and toxicity, future challenges. Methods and findings: After discussion and review of current scientific literature the authors agreed that contaminated surfaces contribute to the transmission of pathogens and may thus pose an infection hazard. Targeted surface disinfection based on a risk profile is seen as an indispensable constituent in a multibarrier approach of universal infection control precautions. Resistance and cross-resistance depend on the disinfectant agent as well as on the microbial species. Prudent implementation of surface disinfection regimens tested to be effective can prevent or minimize adverse effects. Conclusions: Disinfection must be viewed as a holistic process. There is a need for defining standard principles for cleaning and disinfection, for ensuring compliance with these principles by measures such as written standard operating procedures, adequate training and suitable audit systems. Also, test procedures must be set up in order to demonstrate the efficacy of disinfectants including new application methods such as pre-soaked wipes for surface disinfection. PMID:23967396

  17. The role of surface disinfection in infection prevention

    Directory of Open Access Journals (Sweden)

    Gebel, Jürgen

    2013-04-01

    Full Text Available [english] Background: The Rudolf Schuelke Foundation addresses topics related to hygiene, infection prevention and public health. In this context a panel of scientists from various European countries discussed “The Role of Surface Disinfection in Infection Prevention”. The most important findings and conclusions of this meeting are summarised in the present consensus paper.Aim: Although the relevance of surface disinfection is increasingly being accepted, there are still a number of issues which remain controversial. In particular, the following topics were addressed: Transferral of microbes from surface to patients as a cause of infection, requirements for surface disinfectants, biocidal resistance and toxicity, future challenges.Methods and findings: After discussion and review of current scientific literature the authors agreed that contaminated surfaces contribute to the transmission of pathogens and may thus pose an infection hazard. Targeted surface disinfection based on a risk profile is seen as an indispensable constituent in a multibarrier approach of universal infection control precautions. Resistance and cross-resistance depend on the disinfectant agent as well as on the microbial species. Prudent implementation of surface disinfection regimens tested to be effective can prevent or minimize adverse effects.Conclusions: Disinfection must be viewed as a holistic process. There is a need for defining standard principles for cleaning and disinfection, for ensuring compliance with these principles by measures such as written standard operating procedures, adequate training and suitable audit systems. Also, test procedures must be set up in order to demonstrate the efficacy of disinfectants including new application methods such as pre-soaked wipes for surface disinfection.

  18. Radiation disinfection of liquid sewage sludge for safe reutilization

    International Nuclear Information System (INIS)

    Harsoyo; Hilmy, Nazly; Suwirma, S.

    1992-01-01

    Liquid sewage sludge with water content of 80.9% was irradiated with doses of 2, 4, and 6 kGy respectively and then stored at room temperature. Parameter observed were total microbes per g, chemical, physical properties. Total bacterial counts of unirradiated liquid sewage sludge were found to be 12,91 X 10(5) per g, while coliform, enterobacteriaceae, staphylococcus, fecal streptococcus, and pseudomonas were found to be 76.66 X 10(4) per g, 23.82 X 10(4) per g, 46.57 X 10(3) per g, 6.27 X 10(2) per g, 20.04 X 10(3) per g, respectively. About 10% of the total coliform were escherichia coli. Irradiation dose of 4 kGy eliminated salmonella from all samples observed. No shigella was found in the samples. Total nitrogen contents of the liquid sewage sludge ranged berween 0.34 and 0.48%, phosphorus between 0.78 and 1.04%, and potassium between 0.04 and 0.06%. Heavy metal elements were found only in very small amount. The BOD(5), COD, solid suspension, particle size, and sedimentation rate of unirradiated liquid sewage sludge were found to be 1.49 ppm, 13.93% W, 46 mg/ml, 0.0035 ml, and 11.30 cm/week, respectively. A combination of irradiation at 4 kGy and storage for 4 weeks could eliminate enterobacteriaceae, staphylococcus, fecal streptococcus, psedomonas, and salmonella in the liquid sewage sludge. (authors). 9 refs, 13 tabs

  19. Improved Drinking Water Disinfection with UVC-LEDs for Escherichia Coli and Bacillus Subtilis Utilizing Quartz Tubes as Light Guide

    Directory of Open Access Journals (Sweden)

    Andrej Gross

    2015-08-01

    Full Text Available A new approach is investigated utilizing light guidance capabilities of optical pure quartz glass in order to maximize drinking water disinfection efficiency with UVC-light-emitting diodes (LEDs. Two experimental setups consisting of soda-lime AR® glass (VWR, Darmstadt, Germany or HSQ® 100 quartz glass (Heraeus, Wasserburg, Germany reactors were designed to compare disinfection rates with and without total reflection of UVC radiation along the reactor walls. Each reactor was filled with 9 mL bacteria samples containing either E. coli DSM (Deutsche Sammlung von Mikroorganismen 498 or B. subtilis DSM 402 strains (concentration 1–3 × 106 colony forming units (CFU/mL with and without additional mixing and irradiation periods of 10, 40, and 90 s. Disinfection rates were increased up to 0.95 log10 (E. coli and 0.75 log10 (B. subtilis by the light guide approach in stagnant samples. The same experiments with mixing of the samples resulted in an increased disinfection efficiency of 3.07 log10 (E. coli and 1.59 log10 (B. subtilis. Optical calculations determine that total reflection is achieved with the applied UVC-LED’s viewing angle of 15°. Furthermore measurements show that HSQ® 100 quartz has a transmittance of 92% at 280 nm UVC irradiation compared to the transmittance of soda-lime glass of 2% (1 mm wall thickness.

  20. Effect Of Storage And Disinfection Methods Of Extracted Bovine Teeth On Bond Strength To Dentin

    OpenAIRE

    Humel M.M.C.; Oliveira M.T.; Cavalli V.; Giannini M.

    2007-01-01

    The aim of this study was to evaluate the effect of storage and disinfection methods (SDM) on bond strength (BS) to bovine dentin, using two adhesive systems. Adper Single Bond and Clearfil Protect Bond. Method: Extracted bovine teeth were assigned to the following SDM: 100% Humidity (HU); Gamma Radiation (GR); Autoclave (AU): 0.10g/mL Thymol (TH); 10% Formatin (FO); Frozen (FR); 0.2% Sodium Azide (SA) and 0.5% Chloramine T (CT) (n=10). The GR and AU groups were submitted to sterilization met...

  1. Use of radiocarbon technique for archaelogic dating

    International Nuclear Information System (INIS)

    Chausson, Y.

    1986-01-01

    The nuclear technique based on the beta radiation measurements emitted by the radiocarbon is applied an the geochronologycal dating of organic samples of prehistoric fires and sambaqui shells. This paper describes the origin of the method, the technique used and its applications, the analysis method, the equipments and the experiences performed. (Author) [pt

  2. 9 CFR 52.7 - Disinfection of premises, conveyances, and materials.

    Science.gov (United States)

    2010-01-01

    ... cleaning and disinfection, unless an official pseudorabies epidemiologist determines that a shorter or... and disinfection, except for cleaning and disinfection of the conveyances used to transport the swine... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Disinfection of premises, conveyances...

  3. 9 CFR 55.4 - Disinfection of premises, conveyances, and materials.

    Science.gov (United States)

    2010-01-01

    ... paid will be responsible for expenses incurred in connection with the cleaning and disinfection, except that APHIS or a State will pay for cleaning and disinfection of the conveyances used to transport the... disinfecting premises when the procedures needed to conduct effective cleaning and disinfection are unusually...

  4. Dating fossil opal phytoliths

    International Nuclear Information System (INIS)

    Lentfer, C.; Boyd, B.; Torrence, R.

    1999-01-01

    Full text: Opal phytoliths are microscopic silica bodies formed by the precipitation of hydrated silica dioxide (SiO 2 nH 2 0) in, around and between cell walls. They are relatively resistant to degradation in most environments and thus, can occur in large quantities in palaeosediments. Consequently, they are valuable tools for environmental reconstruction. Furthermore, phytoliths are often the only recoverable organic material in well oxidised sediments, the occluded carbon provides the opportunity for dating sediment whose ages have previously been difficult to determine, and thus, increase the potential for fine resolution determination of environmental change. This poster describes the results of an investigation assessing the viability of AMS radiocarbon dating of fossil phytolith inclusions using samples from Garua Island, West New Britain, PNG. Thirteen phytolith samples, isolated from sediments previously dated using tephrastratigraphy and C14 dating of macroremains of nutshells and wood charcoal, were used in the analysis. As a control measure, thirteen parallel samples of microscopic charcoal were also dated using AMS. The results show that the AMS dates for the microscopic charcoal samples are consistent with ages anticipated from the other dating methods, for all but one sample. However, the dates for eight of the thirteen phytolith samples are considerably younger than expected. This bias could be explained by several factors, including downwashing of phytolith through soils, bioturbation, carbon exchange through the siliceous matrix of the phytolith bodies, and contamination from extraneous sources of modern carbon retained in the samples. Research is currently focusing on the investigation of these issues and selected samples are in the process of being retreated with strong oxidising agents to clear contaminants prior to re-dating. Further to this, a full investigation of one profile with a long sequence is underway. High concentrations of

  5. Fine Sprays for Disinfection within Healthcare

    Directory of Open Access Journals (Sweden)

    G Nasr

    2016-09-01

    Full Text Available Problems exist worldwide with Hospital Acquired Infections (HAI's. The Spray Research Group (SRG have been working with relevant industries in developing a product which can provide a delivery system for treatment chemicals for surfaces, including the design and testing of a novel Spill-Return Atomiser (SRA for this purpose. A comprehensive description of this atomiser has already been given. This paper reports on a new application of this atomiser and discusses the problem of spray coating for disinfection that has been considered very little in previous work. The related spray coating performance tests in developing the product are thus provided. The experimental work includes determining the required spray duration and the coverage area produced by different sprays, including the analysis of the effects of atomiser positions, configurations, and the required number of atomisers. Comparison is made with the efficacy of an ultrasonic gas atomiser that is currently used for this purpose. The investigation has found that the utilisation of fine sprays (10μm>D32>25μm at high liquid pressure (<12MPa and low flow rates (<0.3 l/min is suitable for surface disinfection in healthcare applications (i.e. MRSA, VRSA etc.

  6. Cleansing and Disinfection in the Food Industry

    Directory of Open Access Journals (Sweden)

    Ruhtan Baskaya

    2009-02-01

    Full Text Available In the applications of industrial hygiene, it is of utmost importance to define the potential risk factors in the business enterprise in question, to pay sufficient consideration to those factors, and to spend every effort for their checking and elimination. In that sense, cleansing and disinfection applications have a basic importance. Food hygiene covers all the efforts spent in order to ensure the proper conditions for the production of healthy food at every stage of the production process, extending from the farm to the table. Cleansing is the removal of the dirt or food leftovers found on the tools and equipment contacting food, and preventing their conversion into a convenient millieu for the reproduction of microorganisms. Cleansing is the process of removing not only the visible dirts and leftovers, but also a large part of the visible microorganisms. Disinfection is applied after cleansing; it is the process of disintegration of microorganisms which can cause contamination, or reduction of those microorganisms to minimum levels so that they can not create any harmful effects. [TAF Prev Med Bull 2009; 8(1.000: 93-106

  7. Wastewater disinfection with peracetic acid and UV

    International Nuclear Information System (INIS)

    Caretti, C.; Lubello, C.

    2001-01-01

    Was investigated the synergy between UV and peracetic acid (PAA) through a five months on-site experimental study in a pilot plant fed by the secondary effluent of the central wastewater treatment plant of Pistoia, Italy. This experiment is a part of a larger research project on advanced treatment for municipal wastewater reuse in agriculture. Because of Italy's strict limits on unrestricted wastewater reuse in agriculture (2 CFU total coliform/100 ml), a very high degree of disinfection is necessary. In the investigated experimental conditions, it has been impossible to meet such values through an exclusive use of UV irradiation (the UV unit reaches at most 4 Log inactivation). Low levels of PAA greatly enhance the decline of indicator levels, but higher unsustainable doses are required to hit the Italian limit. Through a poor amount of information on the subject was available in literature, it was tried to find out how the disinfection efficiency could improve by simultaneously using UV and PAA. It was found out that a combined treatment is satisfactory and that it is more advantage of the hydroxyl radicals formation due to the PAA photo lysis. The application of 2 ppm of PAA with an UV dose of 192 mWscm - 2 is enough to meet the Italian limit [it

  8. Quality control of disinfection in ultrasonic baths

    Energy Technology Data Exchange (ETDEWEB)

    Schoene, H. [Technical University Dresden (Germany). Faculty of Mechanical Engineering; Jatzwauk, L. [University Hospital of the Technical University Dresden (Germany). Abt. Krankenhaushygiene

    2002-07-01

    Numerous investigations under laboratory conditions confirmed the microbicidal efficacy of ultrasonication. Morphological destruction was shown on bacteria and fungi as well as on different virus species. Ultrasonic treatment seems to increase the effect of different antibiotics and disinfectants. Reasons for this synergism are largely unknown and uninvestigated, but the active principle seems to bee the dispersing effect of ultrasonication in combination with the destruction of cell wall or cell membrane. Unfortunately no validation of test conditions exists for most of these investigations, regarding intensity and frequency of ultrasonic waves, temperature of liquid medium and measurement of cavitation which is an essential part of physical and chemical effects in ultrasonic baths. In contrast to most laboratory experiments sound density of ultrasound for treatment of medical instruments is below 1 W/cm{sup 2} because instruments will be destroyed under stronger ultrasonic conditions. The frequency is below 50 KHz. This paper describes bactericidal and fungicidal effects of low- intensity-ultrasonication and its synergistical support to chemical disinfection. (orig.)

  9. Effects of disinfecting alginate impressions on the scratch hardness of stone models.

    Science.gov (United States)

    Hiraguchi, Hisako; Nakagawa, Hisami; Wakashima, Mitsuru; Miyanaga, Kohichi; Saigo, Masataka; Nishiyama, Minoru

    2006-03-01

    This study investigated the effects of disinfecting alginate impressions on the scratch depth of resultant stone models. Eleven brands of alginate impression material and two disinfectants, 1% sodium hypochlorite and 2% glutaraldehyde, were used. Impressions were immersed in disinfectant solutions or stored in sealed bags after spraying with disinfectants, and then poured with a type V dental stone. The scratch depth of the stone model obtained from disinfected impression was measured. The storage of alginate impressions after spraying with disinfectants did not increase the scratch depth of resultant stone models. However, the effect of immersion in disinfectants on scratch depth varied with the brand of the alginate impression material.

  10. Inactivation model for disinfection of biofilms in drinking water

    International Nuclear Information System (INIS)

    Karlicki, A.; O'Leary, K.C.; Gagnon, G.A.

    2002-01-01

    The purpose of the project was to investigate experimentally the effects of free chlorine, monochloramine and chlorine dioxide on the removal of biofilm growth in water as it applies to drinking water in distribution systems. In particular, biofilm kill for a particular dosage of disinfectant was measured as a function of time for each disinfectant over a range of disinfectant concentrations. These results were used to formulate concentration-time (Ct) inactivation values for each disinfectant to compare the efficacy of the three disinfectants for biofilm control. The biofilm reactor system consisted of a 125 mL columns, each containing tightly packed 3 mm glass beads on which heterotrophic bacterial biofilm is established. Following an initial biofilm inoculation period, the glass beads were removed from the columns and placed into glass jars for disinfection with free chlorine, monochloramine and chlorine dioxide. Cell counts were determined on a time series basis with the goal of achieving a Ct inactivation model that is similar to models presently used for inactivation of suspended cells. Ultimately this research could be used to develop a rationale method for setting regulatory values for secondary disinfection in drinking water distribution systems, which presently in only a few states and provinces. (author)

  11. ASSESSMENT OF ACTION OF DISINFECTANTS AGAINST LISTERIA MONOCYTOGENES BIOFILMS

    Directory of Open Access Journals (Sweden)

    T. K. CABEÇA

    2008-12-01

    Full Text Available

    The purpose of this study was to assess the action of various disinfectants used in food industry against biofilm cells of Listeria monocytogenes formed on stainless steel surfaces during 24, 72 and 120 hours. Numbers of viable biofilm cells decreased after treatment with all the tested disinfectants (iodine, biguanide, quaternary ammonium compounds, peracetic acid and sodium hypochlorite. Sodium hypochlorite was the most effective disinfectant against the biofilm cells, while biguanide and iodine were the least. Scanning electron microscopy observations demonstrated attached cells on stainless steel surfaces after treatment with all the disinfectants. These observations showed that microorganisms were not completely removed from stainless steel surfaces after treatment with the disinfectants, however, the attachment did not means the viability of remaining cells. The biofilm age in hours (24, 72 and 120 had no apparent influence on resistance of microbiological cells to the disinfectants under study. In conclusion biofilm cells of L. monocytogenes can withstand disinfectants action.

  12. Wettability changes in polyether impression materials subjected to immersion disinfection.

    Science.gov (United States)

    Shetty, Shweta; Kamat, Giridhar; Shetty, Rajesh

    2013-07-01

    Disinfection of impression materials prevents cross-contamination; however, the disinfectants may alter the wettability property. The purpose of this investigation was to evaluate the wettability changes of polyether impression material after immersing in four different chemical disinfectant solutions for a period of 10 min and 30 min, respectively. A total of 45 samples of polyether dental impression material (Impregum soft, 3MESPE, St. Paul, MN, USA) were randomly divided into nine groups with five specimens each. Each specimen was disc shaped, flat of 32 mm diameter and 3 mm thickness. The samples were immersed in four disinfectant solutions: 2% Glutaraldehyde, 5% sodium hypochlorite, 0.05% iodophor, and 5.25% phenol for 10 min and 30 min, respectively. The control was without disinfection. Wettability of the samples was assessed by measuring the contact angle by using the Telescopic Goniometer. Data were subjected to analysis of variance (Fisher's test) and Tukey's post hoc test for multiple comparisons at 5% level of significance. The contact angle of 20.21° ± 0.22° were recorded in the control samples. After 10 min, the samples that were immersed in 5% sodium hypochlorite and 5.25% phenol showed significant statistical increase in the contact angle as compared to the control (P polyether material. Within the limitations of the study, 2% glutaraldehyde proved safe for 10 min of immersion disinfection while 0.05% iodophor holds promise as an effective disinfectant without affecting the wettability of the material.

  13. Efficacy of a variety of disinfectants against Listeria spp.

    Science.gov (United States)

    Best, M; Kennedy, M E; Coates, F

    1990-02-01

    The efficacy of 14 disinfectants against Listeria innocua and two strains of Listeria monocytogenes in the presence of organic matter was studied. Quantitative efficacy tests were used. Many of the disinfectants tested were not as effective on Listeria spp. when the test organisms were dried onto the surface of steel disks (carrier tests) as they were when the organisms were placed in suspension (suspension test). The presence of whole serum and milk (2% fat) further reduced the disinfectant capacities of most of the formulations studied. Only three disinfectants (povidone-iodine, chlorhexidine gluconate, and glutaraldehyde) were effective in the carrier test in the presence of serum; however, all three were ineffective when challenged with milk (2% fat). Only one solution, sodium dichloroisocyanurate, was effective in the presence of milk. All but four formulations (chloramine-T, phosphoric acid, an iodophor, and formaldehyde) were effective in the suspension tests, regardless of the organic load. L. monocytogenes was observed to be slightly more resistant to disinfection than L. innocua was. There was no difference in disinfectant susceptibility between the two strains of L. monocytogenes. These findings emphasize the need for caution in selecting an appropriate disinfectant for use on contaminated surfaces, particularly in the presence of organic material.

  14. Continuous-flow solar UVB disinfection reactor for drinking water.

    Science.gov (United States)

    Mbonimpa, Eric Gentil; Vadheim, Bryan; Blatchley, Ernest R

    2012-05-01

    Access to safe, reliable sources of drinking water is a long-standing problem among people in developing countries. Sustainable solutions to these problems often involve point-of-use or community-scale water treatment systems that rely on locally-available resources and expertise. This philosophy was used in the development of a continuous-flow, solar UVB disinfection system. Numerical modeling of solar UVB spectral irradiance was used to define temporal variations in spectral irradiance at several geographically-distinct locations. The results of these simulations indicated that a solar UVB system would benefit from incorporation of a device to amplify ambient UVB fluence rate. A compound parabolic collector (CPC) was selected for this purpose. Design of the CPC was based on numerical simulations that accounted for the shape of the collector and reflectance. Based on these simulations, a prototype CPC was constructed using materials that would be available and inexpensive in many developing countries. A UVB-transparent pipe was positioned in the focal area of the CPC; water was pumped through the pipe to allow exposure of waterborne microbes to germicidal solar UVB radiation. The system was demonstrated to be effective for inactivation of Escherichia coli, and DNA-weighted UV dose was shown to govern reactor performance. The design of the reactor is expected to scale linearly, and improvements in process performance (relative to results from the prototype) can be expected by use of larger CPC geometry, inclusion of better reflective materials, and application in areas with greater ambient solar UV spectral irradiance than the location of the prototype tests. The system is expected to have application for water treatment among communities in (developing) countries in near-equatorial and tropical locations. It may also have application for disaster relief or military field operations, as well as in water treatment in areas of developed countries that receive

  15. Drinking Water Supply without Use of a Disinfectant

    Science.gov (United States)

    Rajnochova, Marketa; Tuhovcak, Ladislav; Rucka, Jan

    2018-02-01

    The paper focuses on the issue of drinking water supply without use of any disinfectants. Before the public water supply network operator begins to consider switching to operation without use of chemical disinfection, initial assessment should be made, whether or not the water supply system in question is suitable for this type of operation. The assessment is performed by applying the decision algorithm. The initial assessment is followed by another decision algorithm which serves for managing and controlling the process of switching to drinking water supply without use of a disinfectant. The paper also summarizes previous experience and knowledge of this way operated public water supply systems in the Czech Republic.

  16. Sterilization, high-level disinfection, and environmental cleaning.

    Science.gov (United States)

    Rutala, William A; Weber, David J

    2011-03-01

    Failure to perform proper disinfection and sterilization of medical devices may lead to introduction of pathogens, resulting in infection. New techniques have been developed for achieving high-level disinfection and adequate environmental cleanliness. This article examines new technologies for sterilization and high-level disinfection of critical and semicritical items, respectively, and because semicritical items carry the greatest risk of infection, the authors discuss reprocessing semicritical items such as endoscopes and automated endoscope reprocessors, endocavitary probes, prostate biopsy probes, tonometers, laryngoscopes, and infrared coagulation devices. In addition, current issues and practices associated with environmental cleaning are reviewed. Copyright © 2011. Published by Elsevier Inc.

  17. Integration of an innovative biological treatment with physical or chemical disinfection for wastewater reuse

    International Nuclear Information System (INIS)

    De Sanctis, Marco; Del Moro, Guido; Levantesi, Caterina; Luprano, Maria Laura; Di Iaconi, Claudio

    2016-01-01

    In the present paper, the effectiveness of a Sequencing Batch Biofilter Granular Reactor (SBBGR) and its integration with different disinfection strategies (UV irradiation, peracetic acid) for producing an effluent suitable for agricultural use was evaluated. The plant treated raw domestic sewage, and its performances were evaluated in terms of the removal efficiency of a wide group of physical, chemical and microbiological parameters. The SBBGR resulted really efficient in removing suspended solids, COD and nitrogen with an average effluent concentration of 5, 32 and 10 mg/L, respectively. Lower removal efficiency was observed for phosphorus with an average concentration in the effluent of 3 mg/L. Plant effluent was also characterized by an average electrical conductivity and sodium adsorption ratio of 680 μS/cm and 2.9, respectively. Therefore, according to these gross parameters, the SBBGR effluent was conformed to the national standards required in Italy for agricultural reuse. Moreover, disinfection performances of the SBBGR was higher than that of conventional municipal wastewater treatment plants and met the quality criteria suggested by WHO (Escherichia coli < 1000 CFU/100 mL) for agricultural reuse. In particular, the biological treatment by SBBGR removed 3.8 ± 0.4 log units of Giardia lamblia, 2.8 ± 0.8 log units of E. coli, 2.5 ± 0.7 log units of total coliforms, 2.0 ± 0.3 log units of Clostridium perfringens, 2.0 ± 0.4 log units of Cryptosporidium parvum and 1.7 ± 0.7 log units of Somatic coliphages. The investigated disinfection processes (UV and peracetic acid) resulted very effective for total coliforms, E. coli and somatic coliphages. In particular, a UV radiation and peracetic acid doses of 40 mJ/cm"2 and 1 mg/L respectively reduced E. coli content in the effluent below the limit for agricultural reuse in Italy (10 CFU/100 mL). Conversely, they were both ineffective on C.perfringens spores. - Highlights: • SBBGR system showed high

  18. Integration of an innovative biological treatment with physical or chemical disinfection for wastewater reuse

    Energy Technology Data Exchange (ETDEWEB)

    De Sanctis, Marco, E-mail: marco.desanctis@ba.irsa.cnr.it [Water Research Institute, CNR, Via F. De Blasio 5, 70123 Bari (Italy); Del Moro, Guido [Water Research Institute, CNR, Via F. De Blasio 5, 70123 Bari (Italy); Levantesi, Caterina; Luprano, Maria Laura [Water Research Institute, CNR, Via Salaria Km 29.600, 00015 Monterotondo, RM (Italy); Di Iaconi, Claudio [Water Research Institute, CNR, Via F. De Blasio 5, 70123 Bari (Italy)

    2016-02-01

    In the present paper, the effectiveness of a Sequencing Batch Biofilter Granular Reactor (SBBGR) and its integration with different disinfection strategies (UV irradiation, peracetic acid) for producing an effluent suitable for agricultural use was evaluated. The plant treated raw domestic sewage, and its performances were evaluated in terms of the removal efficiency of a wide group of physical, chemical and microbiological parameters. The SBBGR resulted really efficient in removing suspended solids, COD and nitrogen with an average effluent concentration of 5, 32 and 10 mg/L, respectively. Lower removal efficiency was observed for phosphorus with an average concentration in the effluent of 3 mg/L. Plant effluent was also characterized by an average electrical conductivity and sodium adsorption ratio of 680 μS/cm and 2.9, respectively. Therefore, according to these gross parameters, the SBBGR effluent was conformed to the national standards required in Italy for agricultural reuse. Moreover, disinfection performances of the SBBGR was higher than that of conventional municipal wastewater treatment plants and met the quality criteria suggested by WHO (Escherichia coli < 1000 CFU/100 mL) for agricultural reuse. In particular, the biological treatment by SBBGR removed 3.8 ± 0.4 log units of Giardia lamblia, 2.8 ± 0.8 log units of E. coli, 2.5 ± 0.7 log units of total coliforms, 2.0 ± 0.3 log units of Clostridium perfringens, 2.0 ± 0.4 log units of Cryptosporidium parvum and 1.7 ± 0.7 log units of Somatic coliphages. The investigated disinfection processes (UV and peracetic acid) resulted very effective for total coliforms, E. coli and somatic coliphages. In particular, a UV radiation and peracetic acid doses of 40 mJ/cm{sup 2} and 1 mg/L respectively reduced E. coli content in the effluent below the limit for agricultural reuse in Italy (10 CFU/100 mL). Conversely, they were both ineffective on C.perfringens spores. - Highlights: • SBBGR system showed high

  19. Obsidian dating prospects

    International Nuclear Information System (INIS)

    Ambrose, W.

    1997-01-01

    Full text: Developments in the nuclear industry have shown that some of the problems related to the glassification of waste for long term storage are centred on the rate of glass weathering in various repositories. Long term weathering of artificial glasses is paralleled by the archaeological problem of determining hydration rates in obsidian artefacts as a means of dating their manufacture. Figures available for sites in Papua New Guinea indicate that the weathering rate is sufficiently fast to render conventional hydration measurement completely unreliable. This follows from the range of calculated surface reduction rates which range between .0002μ to .004μ per year depending on the site's location and the obsidian source. Hydration rates for key Papua New Guinea obsidians have been determined from long term experimental laboratory exposure and these are used to evaluate the age of obsidians from selected archaeological sites. By adopting a strategy of measuring hydration in concealed fissures both the weathering rate and the dating of the Papua New Guinea obsidians have been successfully achieved. The dissolution rates of natural obsidians could be useful in considering weathering rates for artificial glasses. An improved system for calculating the annual effective hydration temperature is presented which gives a better control of micro-environmental temperature in its crucial rate determining role. The combined result of these developments gives obsidian hydration dating an enhanced capacity to be a useful and independent dating system

  20. Confronting Dating Violence.

    Science.gov (United States)

    McNulty, Raymond J.; Heller, Daniel A.; Binet, Tracy

    1997-01-01

    To be safe havens for children, schools cannot address the intellect only. Brattleboro (Vermont) Union High School went beyond academics by sponsoring a performance of "The Yellow Dress," a powerful one-woman play about a teenage victim of dating violence. The production challenged participants to unite school and community, intellect…

  1. The Realities of Date Rape.

    Science.gov (United States)

    Presley, Cara; Watson, Jennifer; Williams, Audrey R.

    This poster presentation addresses the issue of date rape, specifically in the college environment. Highlighted are date rape statistics, demographics, and date rape drugs. Also discussed are date rape warnings and prevention strategies. It is concluded that college and university administrators must place the issue of date rape and acquaintance…

  2. Efficacy of a high free iodine barrier teat disinfectant for the prevention of naturally occurring new intramammary infections and clinical mastitis in dairy cows.

    Science.gov (United States)

    Martins, C M M R; Pinheiro, E S C; Gentilini, M; Benavides, M Lopez; Santos, M V

    2017-05-01

    Using a natural exposure trial design, the goal of our study was to evaluate the clinical efficacy of an iodine teat disinfectant with barrier properties and a high level of free iodine relative to a conventional iodine teat disinfectant with no barrier properties and low levels of free iodine. During the 18 wk of the trial, quarter milk samples were collected every 2 wk from 385 dairy cows from 2 herds. Cows on both farms were assigned in a balanced way according to milk yield, number of lactation, days in milk, somatic cell count (SCC) and microbiology culture pretrial into one of following groups: nonbarrier post milking teat disinfectant (NBAR; n = 195 cows; 747 quarters) or barrier postmilking teat disinfectant (BAR; n = 190 cows; 728 quarters). Afterward, at each scoring date every 2 wk, milk SCC was quantified in samples from all mammary quarters and microbiologic culture was only performed on milk samples with SCC >200,000 cells/mL for multiparous cows and SCC >100,000 cells/mL for primiparous cows. A new intramammary infection (NIMI) was defined when a quarter had milk SCC 200,000 cells/mL for multiparous cows and >100,000 cells/mL for primiparous cows, and positive microorganism isolation. A quarter could have several NIMI, but only 1 case per specific pathogen was considered. The most frequently isolated microorganism group on both farms was Streptococcus spp. (6.25% of total mammary quarters), followed by coagulase-negative staphylococci (3.6%) and Corynebacterium spp. (1.5%). In the present study, an interaction occurred between treatment and week of trial on the incidence risk of NIMI. Quarters disinfected with BAR had 54 and 37% lower odds of NIMI than quarters disinfected with NBAR at 8 and 16 wk of the trial, respectively; whereas at other weeks of the study both products had similar incidence risks of NIMI. Overall, teats disinfected with BAR had 46% lower odds of acquiring a clinical mastitis than those disinfected with NBAR. We concluded that

  3. Enhanced photocatalytic disinfection of indoor air

    Energy Technology Data Exchange (ETDEWEB)

    Vohra, Amit; Goswami, D.Y.; Deshpande, D.A.; Block, S.S. [Solar Energy and Energy Conversion Laboratory, Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611 (United States)

    2006-04-18

    A silver ion doped TiO{sub 2} based photocatalyst, with improved destruction of airborne microbes, has been developed. The performance of the silver ion doped photocatalyst is demonstrated using a catalyst coated filter in a recirculating air experimental facility. Bacillus cereus, Staphylococcus aureus, Escherichia coli, Aspergillus niger, and MS2 Bacteriophage have been used as indexes to demonstrate the high disinfection efficiency of the enhanced photocatalysis process. The microbial destruction performance of the enhanced photocatalyst is found to be an order of magnitude higher than that of a conventional TiO{sub 2} photocatalyst. The process of enhanced photocatalysis can thus be used effectively against high concentrations of airborne microorganisms, making it an attractive option as a defense against bio-terrorism. (author)

  4. Antimicrobial-Coated Granules for Disinfecting Water

    Science.gov (United States)

    Akse, James R.; Holtsnider, John T.; Kliestik, Helen

    2011-01-01

    Methods of preparing antimicrobialcoated granules for disinfecting flowing potable water have been developed. Like the methods reported in the immediately preceding article, these methods involve chemical preparation of substrate surfaces (in this case, the surfaces of granules) to enable attachment of antimicrobial molecules to the surfaces via covalent bonds. A variety of granular materials have been coated with a variety of antimicrobial agents that include antibiotics, bacteriocins, enzymes, bactericides, and fungicides. When employed in packed beds in flowing water, these antimicrobial-coated granules have been proven effective against gram-positive bacteria, gram-negative bacteria, fungi, and viruses. Composite beds, consisting of multiple layers containing different granular antimicrobial media, have proven particularly effective against a broad spectrum of microorganisms. These media have also proven effective in enhancing or potentiating the biocidal effects of in-line iodinated resins and of very low levels of dissolved elemental iodine.

  5. Preliminary observations of a continuous flow solar disinfection system for a rural community in Kenya

    International Nuclear Information System (INIS)

    Gill, L.W.; Price, C.

    2010-01-01

    This project involves the design and installation of a continuous flow reactor which uses solar radiation, an abundant resource in most sub-Saharan countries, to disinfect water supplies. The system was installed at a rural village in Kenya to disinfect surface water collected at a recently constructed micro-dam. The solar reactor uses CPC reflectors which reflect both direct and diffuse solar radiation onto clear pipes through which the requisite water supply flows. The reaction kinetics for the full-scale design had been determined on a variety of pathogenic micro-organisms under both artificial and real sunlight in controlled conditions. The community fully participated in the planning, installation and subsequent operation of the system. The preliminary water quality results indicate that the system is providing a safe source of water for the community. The installation, commissioning and initial use of the system highlights the critical need for community involvement and approval if such interventions are going to be successful in rural areas, alongside the requirements for strategic and technical support.

  6. Effects of different cavity‑disinfectants and potassium titanyl ...

    African Journals Online (AJOL)

    disinfectants and potassium titanyl phosphate (KTP) laser on microtensile bond strength to primary dentin. Chlorhexidine (CHX), propolis (PRO), ozonated water (OW), gaseous ozone (OG) and KTP laser were used for this purpose. Methodology: ...

  7. Waterline ATS B. globigii spore water disinfection data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Disinfection of B. globigii spores (a non-pathogenic surrogate for B. anthracis) in clean and dirty water using the ATS-Waterline system, which uses ultraviolet...

  8. Effect of ultrasonic pretreatment on purified water disinfection

    International Nuclear Information System (INIS)

    Simon Andreu, P.; Lardin Mifsut, C.; Vergara Romero, L.; Polo Canas, P. M.; Perez Sanchez, P.; Rancano Perez, A.

    2009-01-01

    Due to the importance of a suitable water disinfection in order to insure a pollutant effect minimization against environment, this work has been carried out to determine how can affect an ultrasonic pre-treatment upon disinfection step. It has been confirmed the ultrasonic disintegration of bacterial cells in treated water and disinfectant power of treatment by itself, which is not enough to be used as a single method in water disinfection. It has also been proved that from a technical and economical point of view the combination of UV and ultrasound improves the UV treatment performance. Finally, it has been detected that an ultrasonic pre-treatment increases chlorination effectiveness, however the high cost in this combination makes it unfeasible of industrial scale. (Author) 6 refs

  9. Effect of hydrodynamic cavitation on zooplankton: A tool for disinfection

    Digital Repository Service at National Institute of Oceanography (India)

    Sawant, S.S.; Anil, A.C.; Venkat, K.; Gaonkar, C.; Kolwalkar, J.; Khandeparker, L.; Desai, D.V.; Mahulkar, A.V.; Ranade, V.V.; Pandit, A.B.

    by individual oscillating cavity, cell wall strength and geometrical and operating parameters of cavitation device. Theoretical model for quantifying the cavitationally generated turbulent shear and extent of microbial disinfection has been developed...

  10. Assessment of apparent effectiveness of chemical egg disinfectants ...

    African Journals Online (AJOL)

    Aquaculture holds the potential to supplement catches as well as produce seed ... re-circulating incubation system at the National Aquaculture Center, Domasi, Malawi. ... Key words: Egg, disinfectants, incubation, recirculation, hatchability, egg ...

  11. development of an automated batch-process solar water disinfection

    African Journals Online (AJOL)

    user

    This work presents the development of an automated batch-process water disinfection system ... Locally sourced materials in addition to an Arduinomicro processor were used to control ..... As already mentioned in section 3.1.1, a statistical.

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

    Science.gov (United States)

    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 ...

  13. Selecting a Sustainable Disinfection Technique for Wastewater Reuse Projects

    Directory of Open Access Journals (Sweden)

    Jorge Curiel-Esparza

    2014-09-01

    Full Text Available This paper presents an application of the Analytical Hierarchy Process (AHP by integrating a Delphi process for selecting the best sustainable disinfection technique for wastewater reuse projects. The proposed methodology provides project managers a tool to evaluate problems with multiple criteria and multiple alternatives which involve non-commeasurable decision criteria, with expert opinions playing a major role in the selection of these treatment technologies. Five disinfection techniques for wastewater reuse have been evaluated for each of the nine criteria weighted according to the opinions of consulted experts. Finally, the VIKOR method has been applied to determine a compromise solution, and to establish the stability of the results. Therefore, the expert system proposed to select the optimal disinfection alternative is a hybrid method combining the AHP with the Delphi method and the VIKOR technique, which is shown to be appropriate in realistic scenarios where multiple stakeholders are involved in the selection of a sustainable disinfection technique for wastewater reuse projects.

  14. Mimicking disinfection and drying of biofilms in contaminated endoscopes

    NARCIS (Netherlands)

    Kovaleva, J.; Degener, J. E.; van der Mei, H. C.

    2010-01-01

    The effects of peracetic acid-based (PAA) disinfectant with, and without, additional drying on Candida albicans, Candida parapsilosis, Pseudomonas aeruginosa and Stenotrophomonas maltophilia, isolated from contaminated flexible endoscopes, in single-and dual-species biofilms were studied. Biofilms

  15. Selection Criteria for Water Disinfection Techniques in Agricultural Practices

    OpenAIRE

    Haute, Sam van; Sampers, Imca; Jacxsens, Liesbeth; Uyttendaele, Mieke

    2013-01-01

    This paper comprises a selection tool for water disinfection methods for fresh produce pre- and postharvest practices. A variety of water disinfection technologies is available on the market and no single technology is the best choice for all applications. It can be difficult for end users to choose the technology that is best fit for a specific application. Therefore, the different technologies were characterized in order to identify criteria that influence the suitability of a technology fo...

  16. Methodological approaches to disinfection of human hepatitis B virus.

    OpenAIRE

    Prince, D L; Prince, H N; Thraenhart, O; Muchmore, E; Bonder, E; Pugh, J

    1993-01-01

    Three commercial disinfectants (two quaternary formulations and one phenolic) were tested against human hepatitis B virus (HHBV). The treated virus was assayed for infectivity by the chimpanzee assay and for morphological alteration by the Morphological Alteration and Disintegration Test. The same agents were tested against duck hepatitis B virus in a duck hepatocyte infectivity assay. It is apparent that human and duck hepatitis viruses were relatively susceptible to disinfection, becoming n...

  17. Amino acid racemisation dating

    International Nuclear Information System (INIS)

    Murray-Wallace, C.V.

    1999-01-01

    The potential of the time-dependent amino acid racemisation reaction as a method of age assessment was first reported by Hare and Abelson (1968). They noted that in specimens of the bivalve mollusc Mercenaria sp., greater concentrations of amino acids in the D-configuration with increasing fossil age. Hare and Abelson (1968) also reported negligible racemisation in a modern specimen of Mecanaria sp. On this basis they suggested that the extent of amino acid racemisation (epimerisation in the case of isoleucine) may be used to assess the age of materials within and beyond the range of radiocarbon dating. For the past thirty years amino acid racemisation has been extensively applied in Quaternary research as a method of relative and numeric dating, and a particularly large literature has emerged on the subject

  18. Dating fractures in infants

    Energy Technology Data Exchange (ETDEWEB)

    Halliday, K.E., E-mail: kath.halliday@nuh.nhs.uk [Department of Radiology, Nottingham University Hospitals, Queen' s Medical Centre, Nottingham (United Kingdom); Broderick, N J; Somers, J M [Department of Radiology, Nottingham University Hospitals, Queen' s Medical Centre, Nottingham (United Kingdom); Hawkes, R [Department of Radiology, Paul O' Gorman Building, Bristol (United Kingdom)

    2011-11-15

    Aim: To document the timing of the appearance of the radiological features of fracture healing in a group of infants in which the date of injury was known and to assess the degree of interobserver agreement. Materials and methods: Three paediatric radiologists independently assessed 161 images of 37 long bone fractures in 31 patients aged 0-44 months. The following features were assessed: soft-tissue swelling, subperiosteal new bone formation (SPNBF), definition of fracture line, presence or absence of callus, whether callus was well or ill defined, and the presence of endosteal callus. Results: Agreement between observers was only moderate for all discriminators except SPNBF. SPNBF was invariably seen after 11 days but was uncommon before this time even in the very young. In one case SPNBF was seen at 4 days. Conclusion: With the exception of SPNBF, the criteria relied on to date fractures are either not reproducible or are poor discriminators of fracture age.

  19. Dating fractures in infants

    International Nuclear Information System (INIS)

    Halliday, K.E.; Broderick, N.J.; Somers, J.M.; Hawkes, R.

    2011-01-01

    Aim: To document the timing of the appearance of the radiological features of fracture healing in a group of infants in which the date of injury was known and to assess the degree of interobserver agreement. Materials and methods: Three paediatric radiologists independently assessed 161 images of 37 long bone fractures in 31 patients aged 0-44 months. The following features were assessed: soft-tissue swelling, subperiosteal new bone formation (SPNBF), definition of fracture line, presence or absence of callus, whether callus was well or ill defined, and the presence of endosteal callus. Results: Agreement between observers was only moderate for all discriminators except SPNBF. SPNBF was invariably seen after 11 days but was uncommon before this time even in the very young. In one case SPNBF was seen at 4 days. Conclusion: With the exception of SPNBF, the criteria relied on to date fractures are either not reproducible or are poor discriminators of fracture age.

  20. Radiocarbon dating for contributors

    International Nuclear Information System (INIS)

    Jansen, H.S.

    1984-06-01

    This report describes the radiocarbon facility at the Institute of Nuclear Sciences, and is written for potential contributors, current users, and for those who advise others. The report briefly outlines the principles and practices of C-14 dating; with emphasis on factors that enable contributors to judge whether C-14 work is appropriate, and to assist them with the procedures to be followed in order to get the best results. Age determinations, being the main requirements by contributors, have been discussed in detail

  1. A Review of Heterogeneous Photocatalysis for Water and Surface Disinfection

    Directory of Open Access Journals (Sweden)

    John Anthony Byrne

    2015-03-01

    Full Text Available Photo-excitation of certain semiconductors can lead to the production of reactive oxygen species that can inactivate microorganisms. The mechanisms involved are reviewed, along with two important applications. The first is the use of photocatalysis to enhance the solar disinfection of water. It is estimated that 750 million people do not have accessed to an improved source for drinking and many more rely on sources that are not safe. If one can utilize photocatalysis to enhance the solar disinfection of water and provide an inexpensive, simple method of water disinfection, then it could help reduce the risk of waterborne disease. The second application is the use of photocatalytic coatings to combat healthcare associated infections. Two challenges are considered, i.e., the use of photocatalytic coatings to give “self-disinfecting” surfaces to reduce the risk of transmission of infection via environmental surfaces, and the use of photocatalytic coatings for the decontamination and disinfection of medical devices. In the final section, the development of novel photocatalytic materials for use in disinfection applications is reviewed, taking account of materials, developed for other photocatalytic applications, but which may be transferable for disinfection purposes.

  2. Efficiency of hydrogen peroxide in improving disinfection of ICU rooms.

    Science.gov (United States)

    Blazejewski, Caroline; Wallet, Frédéric; Rouzé, Anahita; Le Guern, Rémi; Ponthieux, Sylvie; Salleron, Julia; Nseir, Saad

    2015-02-02

    The primary objective of this study was to determine the efficiency of hydrogen peroxide (H₂O₂) techniques in disinfection of ICU rooms contaminated with multidrug-resistant organisms (MDRO) after patient discharge. Secondary objectives included comparison of the efficiency of a vaporizator (HPV, Bioquell) and an aerosolizer using H₂O₂, and peracetic acid (aHPP, Anios) in MDRO environmental disinfection, and assessment of toxicity of these techniques. This prospective cross-over study was conducted in five medical and surgical ICUs located in one University hospital, during a 12-week period. Routine terminal cleaning was followed by H₂O₂ disinfection. A total of 24 environmental bacteriological samplings were collected per room, from eight frequently touched surfaces, at three time-points: after patient discharge (T0), after terminal cleaning (T1) and after H₂O₂ disinfection (T2). In total 182 rooms were studied, including 89 (49%) disinfected with aHPP and 93 (51%) with HPV. At T0, 15/182 (8%) rooms were contaminated with at least 1 MDRO (extended spectrum β-lactamase-producing Gram-negative bacilli 50%, imipenem resistant Acinetobacter baumannii 29%, methicillin-resistant Staphylococcus aureus 17%, and Pseudomonas aeruginosa resistant to ceftazidime or imipenem 4%). Routine terminal cleaning reduced environmental bacterial load (P disinfection efficiency.

  3. Shift in the microbial ecology of a hospital hot water system following the introduction of an on-site monochloramine disinfection system.

    Directory of Open Access Journals (Sweden)

    Julianne L Baron

    Full Text Available Drinking water distribution systems, including premise plumbing, contain a diverse microbiological community that may include opportunistic pathogens. On-site supplemental disinfection systems have been proposed as a control method for opportunistic pathogens in premise plumbing. The majority of on-site disinfection systems to date have been installed in hospitals due to the high concentration of opportunistic pathogen susceptible occupants. The installation of on-site supplemental disinfection systems in hospitals allows for evaluation of the impact of on-site disinfection systems on drinking water system microbial ecology prior to widespread application. This study evaluated the impact of supplemental monochloramine on the microbial ecology of a hospital's hot water system. Samples were taken three months and immediately prior to monochloramine treatment and monthly for the first six months of treatment, and all samples were subjected to high throughput Illumina 16S rRNA region sequencing. The microbial community composition of monochloramine treated samples was dramatically different than the baseline months. There was an immediate shift towards decreased relative abundance of Betaproteobacteria, and increased relative abundance of Firmicutes, Alphaproteobacteria, Gammaproteobacteria, Cyanobacteria and Actinobacteria. Following treatment, microbial populations grouped by sampling location rather than sampling time. Over the course of treatment the relative abundance of certain genera containing opportunistic pathogens and genera containing denitrifying bacteria increased. The results demonstrate the driving influence of supplemental disinfection on premise plumbing microbial ecology and suggest the value of further investigation into the overall effects of premise plumbing disinfection strategies on microbial ecology and not solely specific target microorganisms.

  4. Theoretical model for the UV disinfection system in the operating ward of PZU 'Filip Vtori'

    International Nuclear Information System (INIS)

    Ilkov, Marjan

    2010-01-01

    Here we investigate the theoretical modeling of an UV disinfection system for the operating ward in PZU 'FILIP VTORI'. As nocosomial infections pose a serious threat to patients everywhere in the world, here the disinfection of the air and the surfaces is modeled and discussed. The surfaces are disinfected with direct illumination of open UV after hours system, UV curtains, overhead disinfection, floor disinfection and disinfection of the incoming air through the ventilation/air-condition system. From the results it can be seen that the concentrations of bacteria, fungi and viruses drop significantly which in turn should give a significant drop in a number of hospital acquired infections.(Author)

  5. In vitro study on the disinfectability of two split-septum needle-free connection devices using different disinfection procedures

    Directory of Open Access Journals (Sweden)

    Engelhart, Steffen

    2015-12-01

    Full Text Available This in vitro study investigated the external disinfection of two needle-free connection devices (NFC using Octeniderm (spraying and wiping technique vs. Descoderm pads (wiping technique. The split-septum membrane of the NFC was contaminated with >10 CFU . The efficacy of the disinfection at 30 sec. exposure time was controlled by taking a swab sample and by flushing the NFC with sterile 0.9% sodium chloride solution. Disinfection with octenidine dihydrochloride 0.1 g, 1-Propanol 30.0 g, and 2-Propanol 45.0 g in solution was highly effective (CFU reduction ≥4 log against both microorganisms, whereas the use of 63.1 g 2-Propanol in 100 ml solution led to residual contamination with . Our investigation underlines that (i in clinical practice disinfection of NFCs before use is mandatory, and that (ii details of disinfection technique are of utmost importance regarding their efficacy. Our investigation revealed no significant differences between both split-septum NFC types. Clinical studies are needed to confirm a possible superiority of disinfectants with long-lasting residual antimicrobial activity.

  6. Organic chloramines in chlorine-based disinfected water systems: A critical review.

    Science.gov (United States)

    How, Zuo Tong; Kristiana, Ina; Busetti, Francesco; Linge, Kathryn L; Joll, Cynthia A

    2017-08-01

    This paper is a critical review of current knowledge of organic chloramines in water systems, including their formation, stability, toxicity, analytical methods for detection, and their impact on drinking water treatment and quality. The term organic chloramines may refer to any halogenated organic compounds measured as part of combined chlorine (the difference between the measured free and total chlorine concentrations), and may include N-chloramines, N-chloramino acids, N-chloraldimines and N-chloramides. Organic chloramines can form when dissolved organic nitrogen or dissolved organic carbon react with either free chlorine or inorganic chloramines. They are potentially harmful to humans and may exist as an intermediate for other disinfection by-products. However, little information is available on the formation or occurrence of organic chloramines in water due to a number of challenges. One of the biggest challenges for the identification and quantification of organic chloramines in water systems is the lack of appropriate analytical methods. In addition, many of the organic chloramines that form during disinfection are unstable, which results in difficulties in sampling and detection. To date research has focussed on the study of organic monochloramines. However, given that breakpoint chlorination is commonly undertaken in water treatment systems, the formation of organic dichloramines should also be considered. Organic chloramines can be formed from many different precursors and pathways. Therefore, studying the occurrence of their precursors in water systems would enable better prediction and management of their formation. Copyright © 2017. Published by Elsevier B.V.

  7. Dating Violence among College Students

    Science.gov (United States)

    Iconis, Rosemary

    2013-01-01

    Dating violence is a significant problem on college campuses. More than one-fifth of the undergraduate dating population are physically abused by their dating partners and an even greater percentage are psychologically abused. Researchers have identified risk factors for college student dating violence. Preventive interventions are strongly…

  8. Flirting in Online Dating

    DEFF Research Database (Denmark)

    Mortensen, Kristine Køhler

    2017-01-01

    Various fields have examined the activity of flirting, predominantly based on experimental and reported data; the interactional workings are therefore often overlooked. Based on emails and chats from two Danish online dating sites, this article investigates how users negotiate romantic connections...... through the flirting strategy of ‘imagined togetherness’, linguistically constructing imagery of a shared future. Using the notion of the chronotope, turn-by-turn analysis demonstrates how users, embedded in the activity of getting to know each other, tenuously communicate romantic interest by alluding...

  9. Numerical and experimental investigation of UV disinfection for water treatment

    International Nuclear Information System (INIS)

    Li, H.Y.; Osman, H.; Kang, C.W.; Ba, T.

    2017-01-01

    Highlights: • UV irradiation for water treatment is numerically and experimentally investigated. • Fluence rate E increases exponentially with the increase of UVT. • UV dose distribution moves to a high range with increase of UVT and lamp power. • A linear relationship is observed between fluence rate E and average UV dose D_a_v_e. • D_a_v_e decreases with the increase of UVT and fluid flow rate. - Abstract: Disinfection by ultraviolet (UV) for water treatment in a UV reactor is numerically and experimentally investigated in this paper. The flow of water, UV radiation transportation as well as microorganism particle trajectories in the UV reactor is simulated. The effects of different parameters including UV transmittance (UVT), lamp power and water flow rate on the UV dose distribution and average UV dose are studied. The UV reactor performance in terms of average UV dose under these parameters is analysed. Comparisons are made between experiments and simulations on the average UV dose and reasonable agreement is achieved. The results show that the fluence rate increases exponentially with the increase of UVT. The UV dose distribution profiles moves to a high range of UV dose with the increase of UVT and lamp power. The increase of water flow rate reduces the average exposure time of microorganism particles to the UV light, resulting in the shifting of UV dose distribution to a low range of UV dose. A linear relationship is observed between fluence rate and the average UV dose. The average UV dose increases with the increase of lamp power while it decreases with the increase of UVT and water flow rate.

  10. On the factors influencing the performance of solar reactors for water disinfection with photosensitized singlet oxygen.

    Science.gov (United States)

    Manjón, Francisco; Villén, Laura; García-Fresnadillo, David; Orellana, Guillermo

    2008-01-01

    Two solar reactors based on compound parabolic collectors (CPCs) were optimized for water disinfection by photosensitized singlet oxygen (1O2) production in the heterogeneous phase. Sensitizing materials containing Ru(II) complexes immobilized on porous silicone were produced, photochemically characterized, and successfully tested for the inactivation of up to 10(4) CFU mL(-1) of waterborne Escherichia coli (gram-negative) or Enterococcus faecalis (gram-positive) bacteria. The main factors determining the performance of the solar reactors are the type of photosensitizing material, the sensitizer loading, the CPC collector geometry (fin- vs coaxial-type), the fluid rheology, and the balance between concurrent photothermal--photolytic and 1O2 effects on the microorganisms' inactivation. In this way, at the 40 degrees N latitude of Spain, water can be disinfected on a sunny day (0.6-0.8 MJ m(-2) L(-1) accumulated solar radiation dose in the 360-700 nm range, typically 5-6 h of sunlight) with a fin-type reactor containing 0.6 m2 of photosensitizing material saturated with tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II) (ca. 2.0 g m(-2)). The optimum rheological conditions require laminar-to-transitional water flow in both prototypes. The fin-type system showed better inactivation efficiency than the coaxial reactor due to a more important photolytic contribution. The durability of the sensitizing materials was tested and the operational lifetime of the photocatalyst is at least three months without any reduction in the bacteria inactivation efficiency. Solar water disinfection with 1O2-generating films is demonstrated to be an effective technique for use in isolated regions of developing countries with high yearly average sunshine.

  11. Bomb pulse radiocarbon dating

    International Nuclear Information System (INIS)

    Tuniz, C.; Zoppi, U.; Hotchkis, M.A.C.

    2004-01-01

    Modern forensic science has to deal not only with homicides and other traditional crimes but also with more global threats such as the smuggling of nuclear materials, clandestine production of weapons of mass destruction, stockpiling of illicit drugs by state controlled groups and war crimes. Forensic applications have always benefited from the use of advanced analytical tools that can characterize materials found at crime scenes. In this paper we will discuss the use of accelerator mass spectrometry (AMS) as an ultrasensitive tool for the crime laboratories of the third millennium. An important objective in forensic science is to order past events chronologically by analysing materials associated with criminal actions. Radiocarbon dating is known to the general public for its application to historical and prehistorical investigations. Examples of forensic significance include the assassination of the Inca Atahualpa by Francisco Pizarro in the early 1530s, the possible murder of the Tyrolean Ice Man (Oetzi) 5300 years ago and the analysis of the burial cloths allegedly associated with the crucifixion of Jesus Christ . Recent murders, including those associated with war crimes in the Balkans during the 1990s, can be studied using 14 C bomb pulse dating. This method has other forensic applications, including investigation of frauds related to food and wine counterfeiting, dating of opium crops and dating of substances used in biological warfare. AMS extends the applicability of the radiocarbon method, allowing the analysis of 14 C in submilligram organic samples. Specific molecular compounds extracted from bones, hair, skin and other carbon bearing substances of forensic significance can now be dated, enhancing the sensitivity and reliability of chronological determinations. AMS can also be used to analyse rare actinide isotopes released into the environment during the clandestine production of nuclear weapons or associated with the smuggling of nuclear materials. In

  12. Updating dating down under

    International Nuclear Information System (INIS)

    Bristow, J.W.

    1986-01-01

    The article deals with the Sensitive High Resolution Ion Microprobe (SHRIMP), Australia's only microprobe and its applications for geochronology. SHRIMP has the ability to analyse tiny areas (less than 30μm across) within crystals directly, the only sample preparation required being polishing of the crystal surface. Most analyses so far have been done on separated crystals prepared as grain mounts, although an increasing number of analyses are now being made of crystals in rock thin sections where their textural associations can be established. Important features of SHRIMP are its double-focusing mass spectrometer and great physical size, more than 8 meters long, employing a magnet weighing six tons. This enables the machine to distinguish ions with atomic masses differing by less than one part in ten thousand while at the same time having a very great sensitivity. SHRIMP was used for dating crustal zircons from southern African Kimberlites. Although low U and Pb abundances presents problems in peak selection and focusing on SHRIMP its was found that kimberlitic zircons could be dated successfully

  13. Overcoming the problem of residual microbial contamination in dental suction units left by conventional disinfection using novel single component suction handpieces in combination with automated flood disinfection.

    Science.gov (United States)

    Boyle, M A; O'Donnell, M J; Russell, R J; Galvin, N; Swan, J; Coleman, D C

    2015-10-01

    Decontaminating dental chair unit (DCU) suction systems in a convenient, safe and effective manner is problematic. This study aimed to identify and quantify the extent of the problems using 25 DCUs, methodically eliminate these problems and develop an efficient approach for reliable, effective, automated disinfection. DCU suction system residual contamination by environmental and human-derived bacteria was evaluated by microbiological culture following standard aspiration disinfection with a quaternary ammonium disinfectant or alternatively, a novel flooding approach to disinfection. Disinfection of multicomponent suction handpieces, assembled and disassembled, was also studied. A prototype manual and a novel automated Suction Tube Cleaning System (STCS) were developed and tested, as were novel single component suction handpieces. Standard aspiration disinfection consistently failed to decontaminate DCU suction systems effectively. Semi-confluent bacterial growth (101-500 colony forming units (CFU) per culture plate) was recovered from up to 60% of suction filter housings and from up to 19% of high and 37% of low volume suction hoses. Manual and automated flood disinfection of DCU suction systems reduced this dramatically (ranges for filter cage and high and low volume hoses of 0-22, 0-16 and 0-14CFU/plate, respectively) (P<0.0001). Multicomponent suction handpieces could not be adequately disinfected without prior removal and disassembly. Novel single component handpieces, allowed their effective disinfection in situ using the STCS, which virtually eliminated contamination from the entire suction system. Flood disinfection of DCU suction systems and single component handpieces radically improves disinfection efficacy and considerably reduces potential cross-infection and cross-contamination risks. DCU suction systems become heavily contaminated during use. Conventional disinfection does not adequately control this. Furthermore, multicomponent suction handpieces

  14. Bio deterioration management in implementing cultural resources ionizing radiations

    International Nuclear Information System (INIS)

    Ritacco, Miguel

    2012-01-01

    Insects can attack various organic products including those make cultural objects such as furniture, books, yarn, etc.. There are different procedures to disinfect, but the application of radiation ionizing radiation (60Co) has advantages over others because the low doses employed affecting this insects not produce undesirable changes in objects (author)

  15. Electron beam disinfection of sewage sludge

    International Nuclear Information System (INIS)

    Hashimoto, Shoji

    1992-01-01

    Electron beam treatment of dehydrated sewage sludge for safe reutilization was performed. Ranges of total bacterial counts and total coliforms in the sludge were from 1.5 x 10 8 to 1.6 x 10 9 and from 2.2 x 10 7 to 1.5 x 10 8 per wet gram, respectively. Total bacterial counts decreased about 5 log cycles after irradiating 5 kGy and irradiation with 2 kGy was enough to kill all coliforms in sewage sludge. The survival curves of total bacteria, obtained by irradiation in oxygen atmosphere, approached to that in nitrogen atmosphere with the increase of sludge thickness. No effects of dose rate and electron energy were found when the sludge layers were thin enough. Continuous disinfection of sewage sludge cake, with the maximum feed rate of 300 kg-sludge/hr, was successfully performed with a Cockcroft-Walton type electron accelerator, a sludge pump and a flat nozzle. (J.P.N.)

  16. Sterilization and disinfection: the prevailing indifference

    International Nuclear Information System (INIS)

    Mirza, I.

    2007-01-01

    To evaluate the knowledge and attitude of health care professionals towards the process of sterilization and disinfection, and to check the adequacy of the reading material accessible to them. The study comprised of three components. In the first part, sections devoted to this subject in the popular books read by the students of operation theatre assistant course and students of diploma in general nursing were examined for adequacy and authenticity of information. In the second part, standard operating procedures were examined regarding sterilization of textile, rubber tubes of suction units and diathermy hand pieces of 20 operation theatres of three teaching hospital attached to undergraduate medical college of Punjab. In the third part of the study, working knowledge of 64 practicing operation theatre assistants and 57 practicing nurses was assessed through a questionnaire. It was found that popular books either did not contain the required information or the information provided was misleading or incorrect. Standard operating procedures for sterilization of selected items of all the operation theatres studied fell much below the standard of practice desired in the light of current knowledge and contemporary practices. Finally the working knowledge of the professionals studied was much below the bare minimum expected by the profession. There is a dire need for upgrading the knowledge and attitude of health care professionals regarding sterilization, besides improving the operation theatres sterilization procedures. (author)

  17. Disinfection of an advanced primary effluent with peracetic acid and ultraviolet combined treatment: a continuous-flow pilot plant study.

    Science.gov (United States)

    González, Abelardo; Gehr, Ronald; Vaca, Mabel; López, Raymundo

    2012-03-01

    Disinfection of an advanced primary effluent using a continuous-flow combined peracetic acid/ultraviolet (PAA/UV) radiation system was evaluated. The purpose was to determine whether the maximum microbial content, established under Mexican standards for treated wastewaters meant for reuse--less than 240 most probable number fecal coliforms (FC)/100 mL--could be feasibly accomplished using either disinfectant individually, or the combined PAA/UV system. This meant achieving reduction of up to 5 logs, considering initial concentrations of 6.4 x 10(+6) to 5.8 x 10(+7) colony forming units/100 mL. During the tests performed under these experiments, total coliforms (TC) were counted because FC, at the most, will be equal to TC. Peracetic acid disinfection achieved less than 1.5 logs TC reduction when the C(t) x t product was less than 2.26 mg x minimum (min)/L; 3.8 logs for C(t) x t 4.40 mg x min/L; and 5.9 logs for C(t) x t 24.2 mg x min/L. In continuous-flow UV irradiation tests, at a low-operating flow (21 L/min; conditions which produced an average UV fluence of 13.0 mJ/cm2), the highest TC reduction was close to 2.5 logs. The only condition that produced a disinfection efficiency of approximately 5 logs, when both disinfection agents were used together, was the combined process dosing 30 mg PAA/L at a pilot plant flow of 21 L/min and contact time of 10 minutes to attain an average C(t) x t product of 24.2 mg x min/L and an average UV fluence of 13 mJ/cm2. There was no conclusive evidence of a synergistic effect when both disinfectants were employed in combination as compared to the individual effects achieved when used separately, but this does not take into account the nonlinearity (tailing-off) of the dose-response curve.

  18. Radiocarbon dates XXI

    International Nuclear Information System (INIS)

    Lowdon, J.A.; Blake, W. Jr.

    1981-01-01

    This list includes 105 radiocarbon age determinations on 104 geological samples made by the Radiocarbon Dating Laboratory. They are on samples from various areas as follows: Labrador Shelf (2); Newfoundland (12); Nova Scotia (2); New Brunswick (1); Quebec (3); Ontario (1); Manitoba (1); Alberta (2); British Columbia (15); Yukon Territory (35); Northwest Territories, Mainland (10); Northwest Territories, Arctic Archipelago (21). Details of background and standard for the 2 L and 5 L counters during the period from November 4, 1980 to October 31, 1981 are summarized in Tables 1 and 2; Table 3 gives the number of counts used to determine the average background and standard counting rates; and Table 4 lists the number of different background and standard gas preparations used for counting

  19. The Occurrence and Comparative Toxicity of Haloacetaldehyde Disinfection Byproducts in Drinking Water

    Science.gov (United States)

    The introduction of drinking water disinfection greatly reduced the incidence of waterborne diseases. However, the reaction between disinfectants and natural organic matter in the source water can lead to an unintended consequence, which is the formation of drinking water disinfe...

  20. Disinfection of stabilization pond effluent by peracetic acid and sodium hypochlorite

    Directory of Open Access Journals (Sweden)

    Negar Rezania

    2013-01-01

    Conclusions: The study demonstrated that application of combined PAA and NaOCl in disinfecting the effluent of the stabilization pond will promote the efficiency of disinfection process in inactivating the coliform group bacteria and fecal streptococci.

  1. Residual viral and bacterial contamination of surfaces after cleaning and disinfection

    NARCIS (Netherlands)

    Tuladhar, E.; Hazeleger, W.C.; Koopmans, M.; Zwietering, M.H.; Beumer, R.R.; Duizer, E.

    2012-01-01

    Environmental surfaces contaminated with pathogens can be sources of indirect transmission, and cleaning and disinfection are common interventions focused on reducing contamination levels. We determined the efficacy of cleaning and disinfection procedures for reducing contamination by noroviruses,

  2. Integrated Disinfection By-Products Mixtures Research: Concentration by Reverse Osmosis Membrane Techniques of Disinfection By-Products from Water Disinfected by Chlorination and Ozonation/Postchlorination

    Science.gov (United States)

    To conduct the health-effect studies described in subsequent articles in this series, concentrated aqueous mixtures of disinfection by-products were required for the two water treatment trains described in the preceding article (Miltner et al., 2008). To accomplish this, the fini...

  3. Clinical and cost effectiveness of eight disinfection methods for terminal disinfection of hospital isolation rooms contaminated with Clostridium difficile 027.

    Science.gov (United States)

    Doan, L; Forrest, H; Fakis, A; Craig, J; Claxton, L; Khare, M

    2012-10-01

    Clostridium difficile spores can survive in the environment for months or years, and contaminated environmental surfaces are important sources of nosocomial C. difficile transmission. To compare the clinical and cost effectiveness of eight C. difficile environmental disinfection methods for the terminal cleaning of hospital rooms contaminated with C. difficile spores. This was a novel randomized prospective study undertaken in three phases. Each empty hospital room was disinfected, then contaminated with C. difficile spores and disinfected with one of eight disinfection products: hydrogen peroxide vapour (HPV; Bioquell Q10) 350-700 parts per million (ppm); dry ozone at 25 ppm (Meditrox); 1000 ppm chlorine-releasing agent (Actichlor Plus); microfibre cloths (Vermop) used in combination with and without a chlorine-releasing agent; high temperature over heated dry atomized steam cleaning (Polti steam) in combination with a sanitizing solution (HPMed); steam cleaning (Osprey steam); and peracetic acid wipes (Clinell). Swabs were inoculated on to C. difficile-selective agar and colony counts were performed pre and post disinfection for each method. A cost-effectiveness analysis was also undertaken comparing all methods to the current method of 1000 ppm chlorine-releasing agent (Actichlor Plus). Products were ranked according to the log(10) reduction in colony count from contamination phase to disinfection. The three statistically significant most effective products were hydrogen peroxide (2.303); 1000 ppm chlorine-releasing agent (2.223) and peracetic acid wipes (2.134). The cheaper traditional method of using a chlorine-releasing agent for disinfection was as effective as modern methods. Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  4. Selection criteria for water disinfection techniques in agricultural practices.

    Science.gov (United States)

    Haute, Sam van; Sampers, Imca; Jacxsens, Liesbeth; Uyttendaele, Mieke

    2015-01-01

    This paper comprises a selection tool for water disinfection methods for fresh produce pre- and postharvest practices. A variety of water disinfection technologies is available on the market and no single technology is the best choice for all applications. It can be difficult for end users to choose the technology that is best fit for a specific application. Therefore, the different technologies were characterized in order to identify criteria that influence the suitability of a technology for pre- or postharvest applications. Introduced criteria were divided into three principal components: (i) criteria related to the technology and which relate to the disinfection efficiency, (ii) attention points for the management and proper operation, and (iii) necessities in order to sustain the operation with respect to the environment. The selection criteria may help the end user of the water disinfection technology to obtain a systematic insight into all relevant aspects to be considered for preliminary decision making on which technologies should be put to feasibility testing for water disinfection in pre- and postharvest practices of the fresh produce chain.

  5. Microbiological evaluation of ultrasonic nebulization for disinfecting dental impressions.

    Science.gov (United States)

    Mendonca, Marcio Jose; Rafael, Renata Santos; Camilotti, Veridiana; Menolli, Rafael Andrade; Sicoli, Eliseu Augusto; Teixeira, Nancielli; Sinhoreti, Mario Alexandre Coelho

    2013-07-01

    Disinfecting dental impressions is necessary to decrease the risk of cross-contamination in dental offices. Ultrasonic nebulization has been mentioned as a microbicidal technique that can be used to disinfect contaminated dental impressions. This study compared the microbicidal effect of 2% glutaraldehyde and 0.2% peracetic acid for the disinfection of dental impressions made with vinyl polysiloxane, using 2 disinfection methods: immersion and ultrasonic nebulization. Bactericial efficacy was examined using Staphylococcus aureus and Bacillus atrophaeus as indicators. Thirty impressions were obtained and distributed randomly in 5 groups (n = 6). Group 1 was immersed in 2% glutaraldehyde immersion for 10 minutes, Group 2 was immersed in 0.2% peracetic acid for 10 minutes, Group 3 underwent ultrasonic nebulization for 10 minutes in 2% glutaraldehyde solution, Group 4 underwent ultrasonic nebulization for 10 minutes in 0.2% peracetic acid solution, and Group 5 was a control group that received no disinfectant. Both solutions experienced a 100% reduction in microorganisms following ultrasonic nebulization, as did peracetic acid following immersion; however, immersion in glutaraldehyde demonstrated lower values of reduction in B atrophaeus group, with a statistically significant difference compared with the other experimental groups.

  6. Ultraviolet (UV) disinfection of grey water: particle size effects.

    Science.gov (United States)

    Winward, G P; Avery, L M; Stephenson, T; Jefferson, B

    2008-02-01

    The impact of water quality on the ultraviolet (UV) disinfection of grey water was investigated with reference to urban water reuse. Direct UV disinfection of grey water did not meet the stringent California State Title 22 criteria for unrestricted urban water reuse due to the presence of particulate material ranging from or = 2000 microm in size. Grey water was manipulated by settling to produce fractions of varying particle size distributions and blending was employed post-disinfection to extract particle-associated coliforms (PACs). The efficacy of UV disinfection was found to be linked to the particle size of the grey water fractions. The larger particle size fractions with a mean particle size of 262 microm and above were observed to shield more coliforms from UV light than did the smaller particles with a mean particle size below 119 microm. Up to 70% of total coliforms in the larger particle size fractions were particle-associated following a UV dose (fluence) of 260 mJ.cm(-2) and would remain undetected by standard coliform enumeration techniques. Implications for urban water reuse are discussed and recommendations made for grey water treatment to ensure removal of particle-associated indicator bacteria and pathogens prior to UV disinfection.

  7. Fresh water disinfection by pulsed low electric field

    International Nuclear Information System (INIS)

    Zheng, C; Xu, Y; Liu, Z; Yan, K

    2013-01-01

    In this paper, we describe a pulsed low electric field process for water disinfection. Electric intensity of 0.6–1.7 kV cm −1 is applied. Experiments are performed with a 1.2 L axis-cylinder reactor. A bipolar pulsed power source with pulsed width of 25 μs and frequency of 100–3000 Hz is used. Water conductivity of 3–200 μs cm −1 is investigated, which can significantly affect pulsed voltage-current waveforms and injected energy. Energy per pulse rises with increased water conductivity. The initial E. Coli density and water conductivity are two major factors influencing the disinfection. No disinfection effect is performed with deionized water of 3 μs cm −1 . When water conductivity is 25 μs cm −1 and bacteria density is 10 4 –10 6 cfu ml −1 , significant disinfection effect is observed. More than 99% of the cells can be disinfected with an energy density of less than 70 J ml −1 , while water temperature is below 30 °C.

  8. [Decontamination of dental unit waterlines using disinfectants and filters].

    Science.gov (United States)

    Monarca, S; Garusi, G; Gigola, P; Spampinato, L; Zani, C; Sapelli, P L

    2002-10-01

    Bacterial contamination of the dental unit water system can become a health problem for patients, particularly if they are immunodepressed. The present study has had the purpose of evaluating the effectiveness of methods of chemical decontamination using different disinfectants (peracetic acid, hydrogen peroxide, silver salts, chloramine T, glutaraldehyde T4) and methods of physical decontamination using synthetic membranes for the filtration of water. A preliminary removal procedure of the biofilm present in the waterline has been followed in a dental unit prepared on purpose for the research; subsequently different 2-week long maintenance procedures were applied using disinfectants injected by a pump and finally the bacterial contamination of the water flowing from the waterline was evaluated. The physical decontamination was performed using 0.22 mm membrane filters, which have been installed also in another dental unit, and the filtered water was analyzed to detect bacterial contamination. The preliminary procedure of biofilm removal succeeded obtaining germ-free water. Among the disinfectants used for the maintenance of the water quality only glutaraldehyde T4 was able to reduce the bacterial contamination under the limit suggested by the ADA. The membrane filter system was not able to purify the water, but when a disinfectant (peracetic acid) was used in the last part of the waterline good results were obtained. At present no decontamination system of dental waterline is available, and glutaraldehyde T4 seems to be the best disinfectant only if integrated with periodic biofilm removal for the maintenance of the water quality.

  9. Effectiveness of Four Disinfectants against Ebola Virus on Different Materials

    Directory of Open Access Journals (Sweden)

    Sophie Smither

    2016-07-01

    Full Text Available The West Africa Ebola virus (EBOV outbreak has highlighted the need for effective disinfectants capable of reducing viral load in a range of sample types, equipment and settings. Although chlorine-based products are widely used, they can also be damaging to equipment or apparatus that needs continuous use such as aircraft use for transportation of infected people. Two aircraft cleaning solutions were assessed alongside two common laboratory disinfectants in a contact kill assay with EBOV on two aircraft relevant materials representative of a porous and non-porous surface. A decimal log reduction of viral titre of 4 is required for a disinfectant to be deemed effective and two of the disinfectants fulfilled this criteria under the conditions tested. One product, Ardrox 6092, was found to perform similarly to sodium hypochlorite, but as it does not have the corrosive properties of sodium hypochlorite, it could be an alternative disinfectant solution to be used for decontamination of EBOV on sensitive apparatus.

  10. UV disinfection for reuse applications in North America.

    Science.gov (United States)

    Sakamoto, G; Schwartzel, D; Tomowich, D

    2001-01-01

    In an effort to conserve and protect limited water resources, the States of Florida and California have actively promoted wastewater reclamation and have implemented comprehensive regulations covering a range of reuse applications. Florida has a semi-tropical climate with heavy summer rains that are lost due to run off and evaporation. Much of California is arid and suffers periodic droughts, low annual rainfall and depleted ground water supplies. The high population density combined with heavy irrigation demands has depleted ground water supplies resulting in salt-water intrusion. During the past decade, Florida reuse sites have increased dramatically from 118 to 444 plants representing a total flow capacity of 826 MGD. California presently has over 250 plants producing 1 BGD with a projected increase of 160 sites over the next 20 years. To prevent the transmission of waterborne diseases, disinfection of reclaimed water is controlled by stringent regulations. Many states regulate wastewater treatment processes, nutrient removal, final effluent quality and disinfection criteria based upon the specific reuse application. As a rule, the resulting effluents have low turbidity and suspended solids. For such effluents, UV technology can economically achieve the most stringent disinfection targets that are required by the States of California and Florida for restricted and unrestricted reuse. This paper compares UV disinfection for wastewater reuse sites in California and Florida and discusses the effect of effluent quality on UV disinfection.

  11. Cleaning, disinfection and sterilization of surface prion contamination.

    Science.gov (United States)

    McDonnell, G; Dehen, C; Perrin, A; Thomas, V; Igel-Egalon, A; Burke, P A; Deslys, J P; Comoy, E

    2013-12-01

    Prion contamination is a risk during device reprocessing, being difficult to remove and inactivate. Little is known of the combined effects of cleaning, disinfection and sterilization during a typical reprocessing cycle in clinical practice. To investigate the combination of cleaning, disinfection and/or sterilization on reducing the risk of surface prion contamination. In vivo test methods were used to study the impact of cleaning alone and cleaning combined with thermal disinfection and high- or low-temperature sterilization processes. A standardized test method, based on contamination of stainless steel wires with high titres of scrapie-infected brain homogenates, was used to determine infectivity reduction. Traditional chemical methods of surface decontamination against prions were confirmed to be effective, but extended steam sterilization was more variable. Steam sterilization alone reduced the risk of prion contamination under normal or extended exposure conditions, but did show significant variation. Thermal disinfection had no impact in these studies. Cleaning with certain defined formulations in combination with steam sterilization can be an effective prion decontamination process, in particular with alkaline formulations. Low-temperature, gaseous hydrogen peroxide sterilization was also confirmed to reduce infectivity in the presence and absence of cleaning. Prion decontamination is affected by the full reprocessing cycle used on contaminated surfaces. The correct use of defined cleaning, disinfection and sterilization methods as tested in this report in the scrapie infectivity assay can provide a standard precaution against prion contamination. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  12. Disinfection of Water and Wastewater Using Gamma Irradiation in Isfahan Water and Wastewater Treatment Plants

    Directory of Open Access Journals (Sweden)

    Hassan Hashemi

    2011-01-01

    Full Text Available To investigate the effect of gamma irradiation on the disinfection of water and wastewater, water samples were collected from raw and filtered water and wastewater samples were taken from the effluent of the secondary sedimentation, polished effluent (1-day retention time, and also from filtered (rapid sand filter effluent. The samples were irradiated with gamma collimated beam in a batch system using a Co-60 therapeutic gamma radiation machine with a radioactive source emission rate of 405.38CGy/min at different doses of 20-160 Gy and 80-240 Gy, respectively. The samples were analyzed before and after irradiation for total and fecal coliforms. It was observed that nearly 100% reduction was achieved in total and fecal coliforms in water samples treated with a dose of 160 Gy. Depending on effluent quality, disinfection efficiencies achieved using 240 Gy gamma irradiation for inactivation of total coliforms in wastewater samples were 83, 64, and 56 percent for filtered, clarified, and secondary effluents, respectively. The same values were nearly 81, 58, and 46 percent, respectively, for inactivation of fecal coliforms. At lower doses of 120-240Gy, the coliform bacteria were successfully inactivated. It was concluded that a linear correlation holds between the dose delivered and the inactivation of microorganisms, so that inactivation increases with increasing irradiation time.

  13. Dates fruits classification using SVM

    Science.gov (United States)

    Alzu'bi, Reem; Anushya, A.; Hamed, Ebtisam; Al Sha'ar, Eng. Abdelnour; Vincy, B. S. Angela

    2018-04-01

    In this paper, we used SVM in classifying various types of dates using their images. Dates have interesting different characteristics that can be valuable to distinguish and determine a particular date type. These characteristics include shape, texture, and color. A system that achieves 100% accuracy was built to classify the dates which can be eatable and cannot be eatable. The built system helps the food industry and customer in classifying dates depending on specific quality measures giving best performance with specific type of dates.

  14. Using Combined Processes of Filtration and Ultraviolet Irradiation for Effluent Disinfection of Isfahan North Wastewater Treatment Plant in Pilot Scale

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Amin

    2011-07-01

    Full Text Available This study was carried out to evaluate the secondary effluent disinfection of the Isfahannorth municipal wastewater treatment plant using filtration and UV technology in current operational condition. The combined system was used in series in pilot scale including: Pressure Sand Filter + Low Pressure (LP + Medium Pressure (MP UV Lamps. The UV dose varied according to the initial intensity of lamp, flow rate and influent transmittance. Total coliform (TC, fecal coliform (FC and fecal streptococcus (FS were analyzed as microbiological parameters in all effluent samples. TSS, BOD5, COD, VSS, pH and transmittance (UVT percentage were tested as physicochemical parameters, before and after the units. Results showed that the filtration with loading of 1050 lit/m2.hr, followed by MP lamp with dose of 230 mW.s/cm2 is an effective alternative to reduce the TC/FC and FS in the secondary effluent. The combined disinfection processes that were used in this study, could be met the standards of 1000 TC, and 400FC/100ml for effluent discharge to receiving waters or restricted reuses in the agriculture. This process can also inactivate the FS down to 6-log.Using low-pressure lamps due to low dose radiation for disinfection is not cost-effective. In this study, parasite egg counts due to lack of access to accurate identification techniques for alive cyst detection was not examined.

  15. Evaluation of 5 Cleaning and Disinfection Methods for Nets Used to Collect Zebrafish (Danio rerio)

    OpenAIRE

    Collymore, Chereen; Porelli, Gina; Lieggi, Christine; Lipman, Neil S

    2014-01-01

    Few standardized methods of cleaning and disinfecting equipment in zebrafish facilities have been published, even though the effectiveness of these procedures is vital to preventing the transmission of pathogenic organisms. Four chemical disinfectants and rinsing with municipal tap water were evaluated for their ability to disinfect nets used to capture zebrafish. The disinfectants included benzalkonium chloride+methylene blue, sodium hypochlorite, chlorine dioxide, and potassium peroxymonosu...

  16. Effect of alginate chemical disinfection on bacterial count over gypsum cast

    OpenAIRE

    Haralur, Satheesh B.; Al-Dowah, Omir S.; Gana, Naif S.; Al-Hytham, Abdullah

    2012-01-01

    PURPOSE To evaluate the efficacy of sodium hypochlorite (1 : 10) and iodophor disinfectants on alginate impressions along with their effect on the survived bacterium count on the gypsum cast. MATERIALS AND METHODS Four alginate impression on each dentate patients were made, of which Group I were not washed or disinfected, Group II impressions were merely washed with water, Group III were disinfected by spraying with sodium hypochlorite (1 : 10), Group IV were disinfected with iodophor (1 : 21...

  17. Conventional and Alternative Disinfection Methods of Legionella in Water Distribution Systems – Review

    Directory of Open Access Journals (Sweden)

    Pūle Daina

    2016-12-01

    Full Text Available Prevalence of Legionella in drinking water distribution systems is a widespread problem. Outbreaks of Legionella caused diseases occur despite various disinfectants are used in order to control Legionella. Conventional methods like thermal disinfection, silver/copper ionization, ultraviolet irradiation or chlorine-based disinfection have not been effective in the long term for control of biofilm bacteria. Therefore, research to develop more effective disinfection methods is still necessary.

  18. Compact Nd:YAG laser operating at 1.06, 1.32, and 1.44 μm for dental caries effective disinfection

    Science.gov (United States)

    Dostálová, Tat'jana; Jelínková, Helena; Kadlecová, Martina; Němec, Michal; Å ulc, Jan; Fibrich, Martin; Nejezchleb, Karel; Kapitch, Nickalai; Å koda, Václav

    2017-02-01

    The analysis of the disinfection effect of Nd:YAG laser radiation was investigated for patients with high concentration of Streptococcus mutans in saliva (positive result in Saliva-check mutans test). For the interaction the Nd:YAG laser system generated separate switchable wavelengths with the maximum output energies 1.1, 0.6, and 0.3 J for wavelength 1.06 μm, 1.32, μm and 1.44 μm, respectively, was used. Our study proved that after the laser irradiation the Saliva-check test showed negative presence of Streptococcus mutans. The disinfection effect was confirmed for all used radiation wavelength. For 1.44 μm this effect was reached with a smallest energy density.

  19. 40 CFR 141.709 - Developing the disinfection profile and benchmark.

    Science.gov (United States)

    2010-07-01

    ... Cryptosporidium Disinfection Profiling and Benchmarking Requirements § 141.709 Developing the disinfection profile...) of the water before or at the first customer and prior to each additional point of disinfectant...) before or at the first customer during peak hourly flow. (ii) Determine successive CTcalc/CT99.9 values...

  20. 9 CFR 51.8 - Disinfection of premises, conveyances, and materials.

    Science.gov (United States)

    2010-01-01

    ... facilities, conveyances, or other materials on the premises that would require such cleaning and disinfection... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Disinfection of premises, conveyances... ANIMALS DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Cattle, Bison, and Swine § 51.8 Disinfection of...

  1. 9 CFR 91.18 - Cleaning and disinfection of transport carriers for export.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Cleaning and disinfection of transport....18 Cleaning and disinfection of transport carriers for export. All fittings, utensils and equipment... port. Such disinfection of halters, ropes, and similar equipment used in handling and tying of animals...

  2. 9 CFR 77.19 - Cleaning and disinfection of premises, conveyances, and materials.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Cleaning and disinfection of premises... PRODUCTS TUBERCULOSIS Cattle and Bison § 77.19 Cleaning and disinfection of premises, conveyances, and... health officials. Cleaning and disinfection must be completed before the premises, conveyances, or...

  3. 9 CFR 53.7 - Disinfection of premises, conveyances, and materials.

    Science.gov (United States)

    2010-01-01

    ... least 7 days following such cleaning and disinfection, unless the Administrator determines that a... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Disinfection of premises, conveyances... LIVESTOCK OR POULTRY § 53.7 Disinfection of premises, conveyances, and materials. All premises, including...

  4. 9 CFR 77.41 - Cleaning and disinfection of premises, conveyances, and materials.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Cleaning and disinfection of premises... PRODUCTS TUBERCULOSIS Captive Cervids § 77.41 Cleaning and disinfection of premises, conveyances, and... health officials. Cleaning and disinfection must be completed before the premises, conveyances, or...

  5. Genotoxicity of the disinfection by-products resulting from peracetic acid- or hypochlorite-disinfected sewage wastewater.

    Science.gov (United States)

    Crebelli, R; Conti, L; Monarca, S; Feretti, D; Zerbini, I; Zani, C; Veschetti, E; Cutilli, D; Ottaviani, M

    2005-03-01

    Wastewater disinfection is routinely carried out to prevent the spread of human pathogens present in wastewater effluents. To this aim, chemical and physical treatments are applied to the effluents before their emission in water bodies. In this study, the influence of two widely used disinfectants, peracetic acid (PAA) and sodium hypochlorite (NaClO), on the formation of mutagenic by-products was investigated. Wastewater samples were collected before and after disinfection, in winter and in summer, at a pilot plant installed in a municipal wastewater-treatment plant. Samples were adsorbed using silica C18 cartridges and the concentrates were tested for mutagenicity in the Salmonella typhimurium reversion test with strains TA98 and TA100. Non-concentrated water samples were tested with two plant genotoxicity assays (the Allium cepa root anaphase aberration test and the Tradescantia/micronucleus test). Mutagenicity assays in bacteria and in Tradescantia showed borderline mutagenicity in some of the wastewater samples, independent of the disinfection procedure applied. Negative results were obtained in the A. cepa anaphase aberration test. These results indicate that, in the conditions applied, wastewater disinfection with PAA and NaClO does not lead to the formation of significant amounts of genotoxic by-products.

  6. Application of neutral electrolyzed water to disinfection of alginate impression.

    Science.gov (United States)

    Nagamatsu, Yuki; Chen, Ker-Kong; Nagamatsu, Hiroshi; Kozono, Yoshio; Shimizu, Hiroshi

    2016-01-01

    Neutral electrolyzed water was developed with new concepts of long-term good durability and minimum corrosiveness to metal in addition to its excellent bactericidal activities similar to acid type of electrolyzed waters. The present study examined the bactericidal effects of the neutral electrolyzed water on disinfection of the alginate impression of a dental arch model contaminated by bacteria. Only 1-min immersion in neutral electrolyzed water could sufficiently disinfect the alginate impression including the metallic tray under ultrasonic with no significant differences from acid electrolyzed waters. No bactericidal effects were found in any electrolyzed water when used as mixing water. Considering the advantages and disadvantages of each electrolyzed water in a comprehensive way, it was suggested that neutral electrolyzed water may be the most appropriate for the disinfection of alginate impression.

  7. Drinking water and biofilm disinfection by Fenton-like reaction.

    Science.gov (United States)

    Gosselin, F; Madeira, L M; Juhna, T; Block, J C

    2013-10-01

    A Fenton-like disinfection process was conducted with Fenton's reagent (H2O2) at pH 3 or 5 on autochthonous drinking water biofilms grown on corroded or non-corroded pipe material. The biofilm disinfection by Fenton-like oxidation was limited by the low content of iron and copper in the biomass grown on non-corroded plumbing. It was slightly improved by spiking the distribution system with some additional iron source (soluble iron II or ferrihydrite particles appeared as interesting candidates). However successful in situ disinfection of biofilms was only achieved in fully corroded cast iron pipes using H2O2 and adjusting the pH to 5. These new results provide additional support for the use of Fenton's processes for cleaning drinking water distribution systems contaminated with biological agents or organics. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Disinfection of bacteria attached to granular activated carbon.

    Science.gov (United States)

    LeChevallier, M W; Hassenauer, T S; Camper, A K; McFeters, G A

    1984-01-01

    Heterotrophic plate count bacteria, coliform organisms, and pathogenic microorganisms attached to granular activated carbon particles were examined for their susceptibility to chlorine disinfection. When these bacteria were grown on carbon particles and then disinfected with 2.0 mg of chlorine per liter (1.4 to 1.6 mg of free chlorine residual per liter after 1 h) for 1 h, no significant decrease in viable counts was observed. Washed cells attached to the surface of granular activated carbon particles showed similar resistance to chlorine, but a progressive increase in sublethal injury was found. Observations made by scanning electron microscope indicated that granular activated carbon was colonized by bacteria which grow in cracks and crevices and are coated by an extracellular slime layer. These data suggest a possible mechanism by which treatment and disinfection barriers can be penetrated and pathogenic bacteria may enter drinking water supplies. Images PMID:6508306

  9. Disinfection procedures for in vitro propagation of Anthurium

    Directory of Open Access Journals (Sweden)

    Silva Jaime A. Teixeira da

    2015-06-01

    Full Text Available Disinfection of plant material is the most important step of the tissue culture protocol. In this process, an attempt is made to eliminate microbial contaminants from the surface and interior of plant material, thus giving the explant a fighting chance at survival in vitro. Initial cultures of Anthurium species and cultivars, which are usually established from ex vitro material grown in a greenhouse, pots or in the field, easily contaminate the in vitro milieu. This review highlights the differences in disinfection protocols that exist for different species or cultivars of Anthurium. The protocol needs to be adjusted based on the material used: spadices, spathes, seeds, leaves, or roots. Regrettably, most of the currently published protocols, derived from a literature that spans over 100 published papers, have numerous weaknesses and flaws in the information provided pertaining to disinfection and infection levels. Advice for future Anthurium researchers should thus be followed cautiously.

  10. Biophysical methods for disinfection and stimulation of wheat seeds

    International Nuclear Information System (INIS)

    Marinkovic, S.; Marinkovic, B.

    2007-01-01

    In this paper we are shown results of applying electron treatment (disinfection of seed by electrons), and RIES method (electromagnetic seed stimulation). Four cultivars of wheat were used in this trial: Renesansa, Durumko, NS-Rana 5 and Sonata. Seed was treated with fast electrons and just before sowing stimulated by ultra low frequency electromagnetic field (from 0 to 100 Hz). For seed disinfection was used chemical treatment as well, as control variant. Control variant for all treatments was seed without any disinfection. The highest number of spikelets per spike was obtained at variant H+RIES. The highest spike length was obtained at variants e sup(-) + RIES and control. At variant H+RIES was achieved the highest grain number. Treatment H had influence on decreasing of grain mass per spike in relation to control variant, for significant value of 0.15 g. The highest grain mass per spike was obtained at variant e sup(-) + RIES

  11. A novel cupping-assisted plasma treatment for skin disinfection

    Science.gov (United States)

    Xiong, Zilan; Graves, David B.

    2017-02-01

    A novel plasma treatment method/plasma source called cupping-assisted plasma treatment/source for skin disinfection is introduced. The idea combines ancient Chinese ‘cupping’ technology with plasma sources to generate active plasma inside an isolated, pressure-controlled chamber attached to the skin. Advantages of lower pressure include reducing the threshold voltage for plasma ignition and improving the spatial uniformity of the plasma treatment. In addition, with reduced pressure inside the cup, skin pore permeability might be increased and it improves attachment of the plasma device to the skin. Moreover, at a given pressure, plasma-generated active species are restricted inside the cup, raising local reactive species concentration and enhancing the measured surface disinfection rate. A surface micro-discharge (SMD) device is used as an example of a working plasma source. We report discharge characteristics and disinfection efficiency as a function of pressure and applied voltage.

  12. Dating technique tested

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    An analytical technique for dating ground water and polar ice up to a million years old has been successfully tested by scientists at Oak Ridge National Laboratory (ORNL). The system, known as a rare gas atom counter, extends the capabilities of resonance ionization mass spectrometry to include counting single atoms of krypton-81. The counter is composed of a pulsed dye laser operated in tandem with a mass spectrometer to separate the various isotopes of krypton. In a collaborative study, ORNL scientists recently used the method for the first time to count krypton-81 in a liter of ground water removed from a sandstone aquifer near Zurich. Fewer than 1000 krypton-81 atoms were isolated from the ground water samples. According to Bernard Lehman, a collaborating geochemist at the University of Bern, this first test proved that counting the small numbers of krypton-81 atoms necessary to make an estimate of the age of water could actually be done. Among the applications of this method, Lehman says, could be improved siting of locations for the disposal of radioactive wastes

  13. Generation of ozone foam and its application for disinfection

    Science.gov (United States)

    Hiragaki, Keisuke; Ishimaru, Tomiya; Nakanishi, Masaru; Muraki, Ryouji; Nieda, Masanori; Yamabe, Chobei

    2015-07-01

    Generated ozone foam was applied to the disinfection of Pseudomonas fluorescens. The effect of disinfection has been confirmed experimentally and new equipment for the disinfection of hands using this ozone foam has been put on the market for the practical use. The ozone foam was produced in the foam generator after mixing the water including surfactant (30 mL/min) and air including ozone (1000 ppm = 2.14 g/m3 ~ 1600 ppm = 3.4 g/m3, 300 mL/min). The liquid-to-gas ratio is 100 L/m3. The concentration of dissolved ozone in the thin liquid films of the bubbles was about 3 mg/L which was measured by the chemical method of the KI absorption and titration of sodium thiosulfate solution. The disinfection test samples were prepared using the PET disk on which Pseudomonas fluorescens of its number of more than 108 were attached. Test sample was inserted into ozone foam set on the glass plate for one to 6 min. The survival rate log (N/N0 decreased with time and its value of about-2.6 (i.e., ~1/400) was obtained at 6 min (2 min × 3 times repeated). It was also confirmed that the ozone foam was useful for the disinfection of hands. For more effective disinfection (in case of taking a long time for foam melting), the ozone foam was broken by force and changed into ozone water by which the survival rate decreased ×4 (i.e., N/N0 = 1/10 000) at 4 ~ 6 min. Contribution to the topical issue "The 14th International Symposium on High Pressure Low Temperature Plasma Chemistry (HAKONE XIV)", edited by Nicolas Gherardi, Ronny Brandenburg and Lars Stollenwark

  14. Evaluation of the efficiency of the photo Fenton disinfection of natural drinking water source during the rainy season in the Sahelian region.

    Science.gov (United States)

    Ndounla, J; Pulgarin, C

    2014-09-15

    The photo-disinfection of water from two different wells (W1, pH: 4.6-5.1 ± 0.02) and (W2 pH: 5.6-5.7 ± 0.02) was carried out during the rainy season at Ouagadougou-Burkina Faso, West Africa. The weather variation during the rainy season significantly affects the photo-disinfection processes (solar disinfection and photo-Fenton). The dilution of the water by rainwater highly affected the chemical composition of the wells' water used in this study; very low iron contents Compared to the ones recorded during the dry season were recorded in all water samples. Both photo-disinfection processes were used to treat 25 L of water in a compound parabolic collector (CPC). None of them have shown the total inactivation of both wild enteric bacteria strains (total coliforms/E. coli and Salmonella spp.) involved in the treatment. However, the total coliforms/E. coli strains were totally inactivated during the exposure under most of the photo-Fenton treatment. Also, the remaining strains, especially those of Salmonella spp. were achieved during the subsequent 24h of dark storage under the action of the Fenton process. Under uniquely solar radiation, total inactivation was recorded only in the total coliforms/E. coli strains. The impact of the available irradiance on the efficiency of the photo-Fenton disinfection of natural water was highlighted during the exposure under high intermittent solar radiation. The impact of the HCO3(-) concentration of both wells' water on the evolution of the pH during the photo-disinfection was recorded. Drastic decrease was noticed after the initial fast increase in presence of low HCO3(-) concentration while a steady state was observed after the increase in presence of higher concentration. The redox activities of the nitrogen components of the water during both photo-disinfection processes have led to increased concentration of nitrite in all the cases and variations were noticed in that of nitrate and ammonia. Copyright © 2014 Elsevier B

  15. Effect of new disinfectant substances on pseudomonas aeruginosa

    International Nuclear Information System (INIS)

    Majtan, V.

    1998-01-01

    The anti-bacterial effect of 13 new commercially manufactured disinfectant substances on P. aeruginosa strain was studied. The substances tested represent 9 quaternary ammonium salts QAT and 4 combined QAT with other ingredients. The antimicrobial efficacy was characterised by influencing the growth and reproduction of bacterial cells expressed either by MIC and ED 50 as well as and ED 50 , as well as by the inhibition of incorporation rate of incorporation rate of [ 14 C] adenine and [ 14 C] leucine. The method of inhibition of [ 14 C] precursors is suitable as one from possible evaluation criterion on anti-bacterial efficacy of synthetic disinfectant substances. (authors)

  16. [Control of disinfection in the buildings of pig farms].

    Science.gov (United States)

    Maris, P

    1990-01-01

    A survey carried out in pig farms was undertaken in order to compare 4 disinfectants used in 13 disinfecting operations, during the vacation period. It was immediately noticeable that after swabbing and counting the staphylococci, the chloramine T-based preparation was more effective than the quaternary ammonium-aldehyde association, phenolic acid derivatives or the quaternary ammonium preparations. We then observed that although the number of organisms decreased by 99.8%, their number on slatted floors still ranged between 0.02 x 10(4) and 3 x 10(4) per cm2.

  17. Monitoring and improving the effectiveness of surface cleaning and disinfection.

    Science.gov (United States)

    Rutala, William A; Weber, David J

    2016-05-02

    Disinfection of noncritical environmental surfaces and equipment is an essential component of an infection prevention program. Noncritical environmental surfaces and noncritical medical equipment surfaces may become contaminated with infectious agents and may contribute to cross-transmission by acquisition of transient hand carriage by health care personnel. Disinfection should render surfaces and equipment free of pathogens in sufficient numbers to prevent human disease (ie, hygienically clean). Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  18. Effects of ozone, ultraviolet and peracetic acid disinfection of a primary-treated municipal effluent on the immune system of rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Hébert, N; Gagné, F; Cejka, P; Bouchard, B; Hausler, R; Cyr, D G; Blaise, C; Fournier, M

    2008-08-01

    Municipal sewage effluents are complex mixtures that are known to compromise the health condition of aquatic organisms. The aim of this study was to evaluate the impacts of various wastewater disinfection processes on the immune system of juvenile rainbow trout (Oncorhynchus mykiss). The trout were exposed to a primary-treated effluent for 28 days before and after one of each of the following treatments: ultraviolet (UV) radiation, ozonation and peracetic acid. Immune function was characterized in leucocytes from the anterior head kidney by the following three parameters: phagocytosis activity, natural cytotoxic cells (NCC) function and lymphocyte (B and T) proliferation assays. The results show that the fish mass to length ratio was significantly decreased for the primary-treated and all three disinfection processes. Exposure to the primary-treated effluent led to a significant increase in macrophage-related phagocytosis; the addition of a disinfection step was effective in removing this effect. Both unstimulated and mitogen-stimulated T lymphocyte proliferation in fish decreased dramatically in fish exposed to the ozonated effluent compared to fish exposed to either the primary-treated effluent or to aquarium water. Stimulation of T lymphocytes proliferation was observed with the peracetic acid treatment group. In conclusion, the disinfection strategy used can modify the immune system in fish at the level of T lymphocyte proliferation but was effective to remove the effects on phagocytosis activity.

  19. [Experiments on disinfection of vaccinia virus embedded in scabs and/or at the hand].

    Science.gov (United States)

    Schümann, K; Grossgebauer, K

    1977-01-01

    Vaccinia viruses embedded in rabbit dermal scabs were subjected to physical and chemical disinfection procedures. Scabs were suspended in vitro without saline or in physiological saline, and left for 1 hour at 70 to 90 degrees C. A complete inactivation was achived only in those scab samples which had been incubated at 90 degrees C for 1 hour and suspended in physiological saline. Scabs which had been placed in a disinfecting apparatus (Vacudes 4000) filled with mattrasses consistently proved to be free of infectious vaccinia viruses in each of the chosen programs. In addition scabs were subjected to disinfection by means of chemical disinfecting agents. The scabs had been placed in a chemical disinfecting suspension and left there for 90 minutes. Complete disinfection was obtained with glutaraldehyde 2%, formaldehyde 2%, Lysoformin 2% or 3%, phenol 5% and chloramine T 2%. Complete disinfection was likewise achieved after 3 hours treatment with some alchohols (ethylalcohol 80%, isopropylalcohol 7%, n-propylalcohol 60%), Amocid 5% and formaldehyde 1%.0.5% formaldehyde caused complete disinfection when applied for 6 hours. The only exception was a Quat which did not disinfect fully even after 18 hours application. Concerning the tests to disinfect the hands complete disinfection occurs when using chloramine T (1.5%) or isopropylalcohol (70%) in 2 to 5 minutes. Further tests were performed with scabs which were placed in sick rooms that were terminally disinfected with formaline vapor. It could be confirmed that the usual terminal disinfection with formaldehyde vapor was unable to completely disinfect the scabs. It is necessary to double the amount of formaldehyde (10 g formaldehyde per cubic metre of space) and prolong the period of treatment to 24 hours to achieve a greater degree of disinfection rate.

  20. [The posibility of usage microwave energy as an alternative method of disinfection for silicone impressions in orthopaedic dentistry].

    Science.gov (United States)

    Nespriad'ko, V P; Shevchuk, V O; Omel'ianenko, M D

    2011-01-01

    In this experimental investigation estimated the effect of microwave disinfection on the alteration of dimensional stability of silicone impressions and gypsum casts poured from them comparing to an invariable parameters of metal die. In this article uncovers the main point of origin, spreading and influence according to the classical theory of electro-magnetic waves (EMW) as an example was used the model M745R Samsung microwave oven. We evaluated possibilities and advantages of use the auxiliary plant for flowing regulation of the power of microwave radiation that calls "microUndaDent". It was designed, developed and installated by us in the department of orthopaedic dentistry.

  1. Radiation technology for environmental conservation

    International Nuclear Information System (INIS)

    Machi, Sueo; Tokunaga, Okihiro; Arai, Hidehiko; Hashimoto, Shoji

    1991-01-01

    This paper reviews research and development of radiation technology application for environmental conservation. Our group in cooperation with Ebara Mfg. co., Ltd. first found and studied removals of sulfur dioxide and nitrogen oxides from flue gases by electron beam irradiation. Most of sulfer dioxide and nitrogen oxides are converted to ammonium sulfate and nitrate by radiation with the addition of ammonia. Feasibility studies of this technology by pilot scale experiments have been carried out in Japan, USA and Germany for flue gases from iron-ore sintering furnace and coal fire power station. About 90 % of CO 2 and NO X are removed with 15 kGy. Organic pollutants in wastewater, drinking water and ground water have been found to be reduced by radiation technology. Synergetic effect of radiation and ozone to remove pollutants was also found. Disinfection of water effluent from sewage water treatment plant by radiation instead of using chlorine to avoid formation of chlorinated organic compounds has been studied by our group. Efficient composting of sewage sludge using radiation disinfection followed by fermentation has been developed and produced compost can be used as fertilizer. In conclusion, radiation technology can provide new efficient treatment method for wastes. (author)

  2. Radiation technology for environmental conservation

    Energy Technology Data Exchange (ETDEWEB)

    Machi, Sueo; Tokunaga, Okihiro; Arai, Hidehiko; Hashimoto, Shoji [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1991-01-01

    This paper reviews research and development of radiation technology application for environmental conservation. Our group in cooperation with Ebara Mfg. co., Ltd. first found and studied removals of sulfur dioxide and nitrogen oxides from flue gases by electron beam irradiation. Most of sulfer dioxide and nitrogen oxides are converted to ammonium sulfate and nitrate by radiation with the addition of ammonia. Feasibility studies of this technology by pilot scale experiments have been carried out in Japan, USA and Germany for flue gases from iron-ore sintering furnace and coal fire power station. About 90 % of CO{sub 2} and NO{sub X} are removed with 15 kGy. Organic pollutants in wastewater, drinking water and ground water have been found to be reduced by radiation technology. Synergetic effect of radiation and ozone to remove pollutants was also found. Disinfection of water effluent from sewage water treatment plant by radiation instead of using chlorine to avoid formation of chlorinated organic compounds has been studied by our group. Efficient composting of sewage sludge using radiation disinfection followed by fermentation has been developed and produced compost can be used as fertilizer. In conclusion, radiation technology can provide new efficient treatment method for wastes. (author).

  3. Progress in ESR dating of fossils

    International Nuclear Information System (INIS)

    Ikeya, M.

    1983-01-01

    In this review the progress of ESR dating is briefly described together with its historical development. Examples of fossil dating include shells and corals in geological sediments, fossil bones and teeth in anthropology and fossil woods in geology. The total dose of natural radiation (TD) equivalent to the archaeological dose in TL dating was obtained by the additive dose method. Initially, the TDs were plotted against the known ages; using the apparent annual dose-rate thus obtained gives the ESR age within a factor of 2 or 3 for a fossil. Precise assessment of the radiation environment was made later taking the disequilibrium of uranium series disintegration into account. ESR ages of corals agreed well with those obtained by radiocarbon and uranium-thorium methods. The time-independent accumulation rate or a linear accumulation or uranium was adopted as a first sensible model for the opensystem fossil bones: the relation between the TD and the age explains the ages of anthropologically important bones. Lastly, geological assessment of fossil woods was made by ESR based on the organic radicals and electron traps in the silicified part. (author)

  4. Application of a high-level peracetic acid disinfection protocol to re-process antibiotic disinfected skin allografts.

    Science.gov (United States)

    Lomas, R J; Huang, Q; Pegg, D E; Kearney, J N

    2004-01-01

    Skin allografts, derived from cadaveric donors, are widely used for the treatment of burns and ulcers. Prior to use in clinical situations, these allografts are disinfected using a cocktail of antibiotics and then cryopreserved. Unfortunately, this antibiotic disinfection procedure fails to decontaminate a significant proportion and these contaminated grafts can not be used clinically. We have investigated whether it is possible to apply a second, more potent disinfection procedure to these contaminated grafts and effectively to re-process them for clinical use. Cadaveric skin grafts, treated with antibiotics and cryopreserved, were thawed and a peracetic acid (PAA) disinfection protocol applied. The grafts were then preserved in a high concentration of glycerol or propylene glycol, and properties thought to be essential for successful clinical performance assessed. The cytotoxicity of the grafts was assessed using both extract and contact assays; damage to the skin collagen was assessed using a collagenase susceptibility assay and the capacity of the grafts to elicit an inflammatory response in vitro was assessed by quantifying the production of the pro-inflammatory cytokine TNF-alpha by human peripheral blood mononuclear phagocytes. PAA disinfection, in conjunction with either glycerol or propylene glycol preservation, did not render the grafts cytotoxic, pro-inflammatory, or increase their susceptibility to collagenase digestion. The rates of penetration of glycerol and propylene glycol into the re-processed skin were comparable to those of fresh skin. This study has demonstrated that PAA disinfection combined with immersion in high concentrations of either glycerol or propylene glycol was an effective method for re-processing contaminated skin allografts, and may justify their clinical use.

  5. The influence of disinfectants on mutagenicity and on toxicity of urban waste water; Valutazione di trattamenti di disinfezione di acque reflue urbane mediante test di tossicita' e di mutagenesi

    Energy Technology Data Exchange (ETDEWEB)

    Monarca, S. [Brescia Univ., Brescia (IT). Dipt. di Medicina Sperimentale e Applicata] [and others

    1999-12-01

    The aim of the research was to study the influence of disinfectants alternative to chlorine, such as chlorine dioxide, ozone, peracetic acid and UV radiation, have on the formation of mutagenic and toxic compounds in waste water disinfection. Preliminary results are presented and discussed. [Italian] Scopo del lavoro e' stato lo studio dell'azione antimicrobica di diversi disinfettanti su acque reflue urbane dopo trattamento secondario, correlando tale parametro con l'attivita' tossica e genotossica prodotta dalla disinfezione. I risultati vengono presentati e discussi.

  6. Ionizing radiation and water reuse

    International Nuclear Information System (INIS)

    Borrely, Sueli Ivone; Sampa, Maria Helena de Oliveira; Oikawa, Hiroshi; Silveira, Carlos Gaia da; Duarte, Celina Lopes; Cherbakian, Eloisa Helena

    2002-01-01

    The aim of the present paper is to point out the possibility of including ionizing radiation for wastewater treatment and reuse. Radiation processing is an efficient technology which can be useful for water reuse once the process can reduce not only the biological contamination but also organic substances, promoting an important acute toxicity removal from aquatic resources. Final secondary effluents from three different wastewater treatment plant were submitted to electron beam radiation and the process efficacy was evaluated. Concerning disinfection, relatively low radiation doses (2,0 - 4,0 kGy) accounted for 4 to 6 cycle log reduction for total coliforms. When radiation was applied for general wastewater improvement related to the chemical contamination, radiation process reduced from 78% up to 100% the total acute toxicity, measured for crustaceans, D. similis, and for V. fiscehri bacteria. (author)

  7. Control of dangerous substances in discharges and microbiological abatement: European framework and a case study of an ozone disinfection system.

    Science.gov (United States)

    Ostoich, M; Serena, F; Falletti, L; Fantoni, A

    2013-01-01

    Directive 2000/60/EC requires the achievement of a 'good chemical status' for surface water within pre-established dates. Disinfection is needed to achieve compulsory final microbial limit values (in Italy for wastewater discharges the parameter Escherichia coli - EC - is imposed by law with a maximum limit value of 5,000 cfu/100 mL). Liquid waste and disinfection by-products must be considered when designing appropriate monitoring of dangerous substances; the specific classes of substances must be investigated according to the typology of received wastewaters and liquid wastes (where applicable) and specific analytical techniques, with Limit of Detection (LOD) lower than the limit values, must be applied; the difficulties faced by national and regional environmental control Agencies is that these techniques have to be applied during ordinary activity and not only for research purposes. The study aims to present the control of dangerous substances, as a screening view, in wastewater treatment plant (WWTP) discharges in the province of Venice (Northern Italy) for the period 2007-2010 based on available data from institutional controls. In addition, the wastewater disinfection process with ozone applied to a medium size WWTP (45,000 Population Equivalents) is presented as a case study, with a view to assessing the microbiological abatement efficacy and the presence of dangerous substances. Discharge quality of the WWTPs in the province of Venice presented mean values that were higher than the LOD, but only for certain metals. For the Paese plant, zinc and chloroform were the only micro-pollutants detected with a higher level than the LOD. From microbiological data in the period 2006-2011 the disinfection abatement efficiency for Paese was, in most cases above 99% for EC, faecal coliform (FC), faecal streptococci (FS) while efficiency was slightly lower for total coliform (TC); however, the proposed criterion aimed at respecting 99.99% abatement was not completely

  8. ESR dating of the fault rocks

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Kwon [Kangwon National Univ., Chuncheon (Korea, Republic of)

    2004-01-15

    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then grow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs, grain size shows a plateau for grains below critical size : these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected near the Ulzin nuclear reactor. ESR signals of quartz grains separated from fault rocks collected from the E-W trend fault are saturated. This indicates that the last movement of these faults had occurred before the quaternary period. ESR dates from the NW trend faults range from 300ka to 700ka. On the other hand, ESR date of the NS trend fault is about 50ka. Results of this research suggest that long-term cyclic fault activity near the Ulzin nuclear reactor continued into the pleistocene.

  9. Does disinfection of environmental surfaces influence nosocomial infection rates? A systematic review.

    Science.gov (United States)

    Dettenkofer, Markus; Wenzler, Sibylle; Amthor, Susanne; Antes, Gerd; Motschall, Edith; Daschner, Franz D

    2004-04-01

    To review the evidence on the effects of disinfection of environmental surfaces in hospitals (as compared with cleaning without use of disinfectants) on the occurrence of nosocomial infections. Systematic review of experimental and nonexperimental intervention studies dealing with environmental disinfection or cleaning in different health care settings. A total of 236 scientific articles were identified. None described a meta-analysis, systematic review, or randomized controlled trial. Only 4 articles described completed cohort studies matching the inclusion criteria. None of these studies showed lower infection rates associated with routine disinfection of surfaces (mainly floors) versus cleaning with detergent only. Disinfectants may pose a danger to staff, patients, and the environment and require special safety precautions. However, targeted disinfection of certain environmental surfaces is in certain instances an established component of hospital infection control. Given the complex, multifactorial nature of nosocomial infections, well-designed studies that systematically investigate the role of surface disinfection are required.

  10. One plunge or two?--hand disinfection with alcohol gel.

    Science.gov (United States)

    Macdonald, Duncan J M; Mckillop, Elisabeth C A; Trotter, Sylvia; Gray, Alastair J R

    2006-04-01

    To compare health care workers' hand surface coverage using two different volumes of alcohol gel for hand disinfection. and methods. A total of 84 members of staff in our hospital were studied. Subjects were asked to disinfect their hands with alcohol gel containing a clear fluorescent substance. Performance was assessed by using UV light to identify areas which had been missed, and the total surface area missed was calculated. A total of 42 subjects received 3.5 ml of alcohol gel, and 42 age-, sex-, and job-matched subjects received 1.75 ml of alcohol gel. Significantly less area was missed when hand disinfecting with double the volume of alcohol gel; 1.23 versus 6.35% surface area was missed (P disinfection significantly improves the efficiency of coverage of the hands with alcohol gel. This may result in lower bacterial count on the hands and may reduce the spread of nosocomial infections including that of methicillin-resistant Staphylococcus aureus.

  11. Surface dielectric barrier discharge jet for skin disinfection

    NARCIS (Netherlands)

    Creyghton, Y.; Meijer, R.; Verweij, P.; Zanden, F. van der; Leenders, P.

    2012-01-01

    A consortium consisting of the research institute TNO, the medical -university and hospital St Radboud and two industrial enterprises is working on a non-thermal plasma treatment method for hand disinfection. The group is seeking for cooperation, in particular in the field of validation methods and

  12. Control of house-dust mites with home disinfectants

    NARCIS (Netherlands)

    Schober, G.; Wetter, G.; Bischoff, E.; Bronswijk, van J.E.M.H.; Kniest, F.M.

    1987-01-01

    Chemical disinfectants and biocidal preparations used in households were tested in the laboratory for their ability to kill the house-dust miteDermatophagoides farinae. Batches of ten specimens were soaked in aqueous solutions or suspensions containing 0.0, 0.1, 0.3, 1.0, 3.0 and 10.0% (by volume)

  13. 9 CFR 53.6 - Disinfection of animals.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Disinfection of animals. 53.6 Section 53.6 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF... of animals. Animals of species not susceptible to the disease for which a quarantine has been...

  14. A parametrical study of disinfection with hydrodynamic cavitation.

    Science.gov (United States)

    Arrojo, S; Benito, Y; Tarifa, A Martínez

    2008-07-01

    The physical and chemical conditions generated by cavitation bubbles can be used to destroy microorganisms and disinfect wastewater. The effect of different cavitation chamber designs and diverse operational parameters on the inactivation rate of Escherichia coli have been studied and used to understand the mechanisms involved in cell disruption.

  15. Disinfection Alternatives for Small Communities in Puerto Rico

    Science.gov (United States)

    Disinfection Alternatives for Small Communities in Puerto Rico Craig Patterson1, Graciela Ramirez Toro2, Harvey Minnigh2, Cristina Maldonado3, and Rajib Sinha4 1U.S. EPA Office of Research and Development, 2Centro de Educación, Conservación e Interpretación Ambiental (CECIA),...

  16. A biocoagulant slow sand filtration for disinfection of Toxoplasma ...

    African Journals Online (AJOL)

    An integrated low-tech biocoagulant-sand filter drum for disinfection of oocysts of Toxoplasma gondii targeted for developing countries was evaluated. Dirty and turbid water (130.3 NTU) from Mezam River and leachates from dump sites and stagnant water in Bamenda, Cameroon, was analyzed microscopically after ...

  17. Assessment of peracetic acid disinfected effluents by microbiotests.

    Science.gov (United States)

    Antonelli, M; Mezzanotte, V; Panouillères, M

    2009-09-01

    Bioassays were performed by commercially available kits on peracetic acid (PAA) solutions, at different concentrations, and on secondary effluents (from two different wastewater treatment plants) after disinfection at bench-scale, considering both samples containing residual active PAA and the same samples where residual PAA was quenched. Four indicator organisms were used: Vibrio fischeri, Thamnocephalus platyurus, Daphnia magna, and Selenastrum capricornutum. The experiments lead to conclude that Thamnocephalus platyurus is a very sensitive organism, probably not adequate to perform a reliable toxicity assessment of effluents for monitoring purposes. The presence of specific organic compounds deriving from human metabolism and urban pollution, even at very low concentrations, can affect the results of bioassays, especially those performed on Vibrio fischeri. PAA is toxic for bacteria and crustaceans even at concentrations lower than the ones commonly used in wastewater disinfection (2-5 mg/L), while its effect on algae is smaller. The toxic effect on bacteria was expected, as PAA is used for disinfection, but its possible influence on biological processes in the receiving aquatic environment should be considered. Toxicity on crustaceans would confirm the fact that discharging disinfected effluents could raise some environmental problems.

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

    Science.gov (United States)

    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.

  19. 7 CFR 301.89-12 - Cleaning, disinfection, and disposal.

    Science.gov (United States)

    2010-01-01

    ... indica must be cleaned and disinfected in accordance with § 301.89-13 prior to being used in the conditioning of seed that has tested negative for the spores of Tilletia indica or to being moved from a... move bunted-kernel-positive host crops, including trucks, railroad cars, and other containers, that...

  20. A prototype catheter designed for ultraviolet C disinfection

    DEFF Research Database (Denmark)

    Bak, Jimmy; Begovic, Tanja

    2013-01-01

    UVC light exposure, sampling and plate counting. Findings Two minutes of UVC exposure was sufficient to obtain 4 log10 disinfection for the full-length prototype catheter. This exposure corresponds to ∼40 mJ/cm2 at the catheter tip and indicates that even shorter exposure times can be achieved...

  1. The Effect of Various Brands of Chloroxylenol disinfectants on Some ...

    African Journals Online (AJOL)

    Suspension and surface viability tests were carried out to determine the effects of various brands of chloroxylenol disinfectants on clinically important nosocomial gram negative and gram-positive organisms. Dettol and morigard brands of chloroxylenol inhibited gram-positive organisms at a dilution of 1 in 50. Tiscol brand of ...

  2. UASB reactor effluent disinfection by ozone and chlorine

    NARCIS (Netherlands)

    Ribeiro da Silvia, G.H.; Bruning, H.; Gerrity, D.; Daniel, L.A.

    2015-01-01

    This research studied the sequential ozone and chlorine process with respect to, the inactivation of indicator bacteria and the formation of ozone disinfection byproducts in sanitary wastewater effluent. The applied ozone doses were 5, 8 and 10 mg.O3.L-1, followed by chlorine doses of 10, 20 and 30

  3. A practical evaluation of detergent and disinfectant solutions on ...

    African Journals Online (AJOL)

    Student01

    2012-01-06

    Jan 6, 2012 ... inactivation efficacy and effect on material corrosion ... Cleaning and disinfection agents were evaluated against selected bacteria on ... bacteria strains: Escherichia coli K12, E. coli DSM 682, Salmonella ... in terms of the lifespan of the equipment, and also ..... Individual descriptions of the observed basis.

  4. The effect of various disinfectants on dental shade guides.

    Science.gov (United States)

    Huang, Peterson Y; Masri, Radi; Romberg, Elaine; Driscoll, Carl F

    2014-09-01

    Dental shade guides are used to evaluate tooth color before prosthodontic procedures and are subjected to disinfection after use. The effect of disinfection on shade guides has not been thoroughly investigated. The purpose of this study was to evaluate the effect of disinfectants on the color of shade tabs. Changes in the color (ΔE) of VITA Classical Shade Guide tabs were measured with a VITA Easyshade spectrophotometer in the CIELAB system and calculated after being subjected to Cavicide, Asepticare TB, Sporicidin, and distilled water (control) over a simulated period of 2 years. Statistical analysis was accomplished by a 2-way analysis of variance followed by the Tukey honestly significant difference (HSD) test (α=.05). A significant difference was noted in the degree of shade tab color change, depending on the type of disinfectant used (F=153.2, PCavicide (ΔE=1.198). The average total CIELAB color difference for 50% human perceptibility is approximately 1 unit (under standardized laboratory conditions). In the oral cavity, however, an average change of 3.7 ΔE units could still allow teeth to be perceived as having the same color. Therefore, although the results are statistically significant, they may not be clinically important. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  5. [The effect of disinfectant soaking on dental gypsum model size].

    Science.gov (United States)

    Zhu, Cao-yun; Xu, Yun-wen; Xu, Kan

    2012-12-01

    To study the influence of disinfectant soaking on the dimensional stability of three kinds of dental gypsum model. Three commonly used gypsums ( type III,IV,Vtype) in clinic were used to make 24 specimens for 50 mm×15 mm×10 mm in size. One hour after release, the specimens were placed for 24 h. A digital caliper was used to measure the size of the gypsum model. Distilled water immersion was as used control, glutaraldehyde disinfectant and Metrix CaviCide disinfectant soaking were used for the experimental group. After soaking for 0.5h, the gypsum models were removed and placed for 0.5 h, 1 h, 2 h, 24 h. The size of the models was measured again using the same method. The data was analyzed with SPSS10.0 software package. The initial gypsum model length was (50.07±0.017) mm, (50.048±0.015) mm and (50.027±0.015) mm. After soaking for different times, the size of the model changed little, and the dimensions changed less than 0.01%. The results show that disinfectant soaking has no significant effect on dental model dimensions.

  6. Effects of Ozone and Photo‑Activated Disinfection against ...

    African Journals Online (AJOL)

    Objectives: The purpose of this study was to compare the antibacterial effects of gaseous ozone (O3) and photo‑activated disinfection (PAD) methods against Enterococcus faecalis (E. faecalis) biofilms. Materials and Methods: Sixty‑five human mandibular premolars with straight root canals were selected. After root canal ...

  7. Moist Heat Disinfection and Revisiting the A0 Concept.

    Science.gov (United States)

    McCormick, Patrick J; Schoene, Michael J; Dehmler, Matthew A; McDonnell, Gerald

    2016-04-02

    Moist heat is employed in the medical device, pharmaceutical, and food processing industries to render products and goods safe for use and human consumption. Applications include its use to pasteurize a broad range of foods and beverages, the control of microbial contamination of blood products, and treatment of bone tissue transplants and vaccines. In the pharmaceutical industry, water heated to 65°C to 80°C is used to sanitize high-purity water systems. In healthcare, it has been employed for decades to disinfect patient care items ranging from bedpans to anesthesia equipment. There is a good understanding of the conditions necessary to achieve disinfection of microorganisms at temperatures ranging from 65°C to 100°C. Based on this information, the efficacy of moist heat processes at a range of exposure times and temperatures can be quantified based on mathematical models such as the A0 calculation. While the A0 concept is recognized within the European healthcare community, it has yet to be widely adopted within the United States. This article provides information regarding the A0 concept, a brief overview of the classification of thermal disinfection for use with healthcare applications within the United States, and recent data on reinvestigating the thermal disinfection of a selected panel of microorganisms and a mixed culture biofilm.

  8. Disinfection Pilot Trial for Little Miami WWTP | Science ...

    Science.gov (United States)

    There is a serious interest growing nationally towards the use of PAA at various stages of public waste water treatment facilities; one of such use is secondary waste water treatment. MSDGC is currently interested in improving efficiency and economic aspects of waste water treatment. MSDGC requested for ORD’s support to evaluate alternative cost-effective disinfectants. This report herein is based on the data generated from the field pilot test conducted at the Little Miami Wastewater Treatment Plant. Chlorine assisted disinfection of wastewaters created the concern regarding the formation of high levels of toxic halogenated disinfection byproducts (DBPs) detrimental to aquatic life and public health. Peracetic acid is emerging as a green alternative to chlorine and claimed to have economic and social benefits. In addition, it is a relatively simple retrofit to the existing chlorine treated wastewater treatment facilities. PAA is appealed to possess a much lower aquatic toxicity profile than chlorine and decays rapidly in the environment, even if overdosed. As a result, PAA generally does not need a quenching step, such as dechlorination, reducing process complexity, sodium pollution and cost. PAA treatment does not result in the formation of chlorinated disinfection by-products such as trihalomethanes (THMs), haloacetic acids and other byproducts such as cyanide and n-Nitrosodimethylamine (NDMA).

  9. Disinfection of wastewater with peracetic acid: a review.

    Science.gov (United States)

    Kitis, Mehmet

    2004-03-01

    Peracetic acid is a strong disinfectant with a wide spectrum of antimicrobial activity. Due to its bactericidal, virucidal, fungicidal, and sporicidal effectiveness as demonstrated in various industries, the use of peracetic acid as a disinfectant for wastewater effluents has been drawing more attention in recent years. The desirable attributes of peracetic acid for wastewater disinfection are the ease of implementing treatment (without the need for expensive capital investment), broad spectrum of activity even in the presence of heterogeneous organic matter, absence of persistent toxic or mutagenic residuals or by-products, no quenching requirement (i.e., no dechlorination), small dependence on pH, short contact time, and effectiveness for primary and secondary effluents. Major disadvantages associated with peracetic acid disinfection are the increases of organic content in the effluent due to acetic acid (AA) and thus in the potential microbial regrowth (acetic acid is already present in the mixture and is also formed after peracetic acid decomposition). Another drawback to the use of peracetic acid is its high cost, which is partly due to limited production capacity worldwide. However, if the demand for peracetic acid increases, especially from the wastewater industry, the future mass production capacity might also be increased, thus lowering the cost. In such a case, in addition to having environmental advantages, peracetic acid may also become cost-competitive with chlorine.

  10. [The principle of registration, evaluation and testing of disinfecting preparations].

    Science.gov (United States)

    Röhm-Rodowald, Ewa; Jakimiak, Bozenna; Podgórska, Marta

    2008-01-01

    Disinfectants are used to produce a state in which the number of living micro-organisms has been reduced to a level which is appropriate to the practical situation. For any products which are included in the Biocidal Directive 98/8/EC, for which specific activity is claimed, test data has to be approved by the regulatory authority and a product license obtained before the product can be offered for sale. Disinfectants can be recorded as biocidal products or medical devices. Presently, it is possible to measure the activity of a product on defined micro-organisms in specified experimental conditions. Efficacy is the result of the use of a product according to a defined application. To allow different requirements in different areas of application, separate tests and pass criteria have been or will be prepared for each of following three areas of application: medical, veterinary and group comprising food, industrial, domestic and institutional areas. The laboratory methods to be used for testing the activity of chemical disinfectants meets the European standards. The tests are categorised on a modular basis as follows: phase 1 tests, phase 2 step 1 tests, phase 2 step 2 tests and phase 3 tests. In order to claim that a product has disinfectant properties, suitable for use in the medical area, the product shall be tested according to European standards: phase 2 step 1 tests, phase 2 step 2 tests. Phase 1 tests are not required to support claims for chemical disinfectants used in human medicine. Only phase 1 tests are required to support claims for active substances for which no particular area of application is specified. Medical devices are subjects to the European Directive 93/42/EEC which requires that a product must carry a CE mark. Disinfectants which are intended specifically by its manufacturer to be used on medical devices are themselves medical devices and so these products, as well as conforming to the instrument disinfection European standards as specified

  11. Sludge irradiation disinfection for beneficial use

    International Nuclear Information System (INIS)

    1980-12-01

    Papers given at the symposium are included in this volume. The symposium was organized to facilitate the transfer of information on the use of sludge irradiation as a process to further reduce pathogens. State-of-the-art gamma radiation of dried sewage solids is reviewed. Separate abstracts have been prepared for individual papers for inclusion in the Energy Data Base

  12. 78 FR 59982 - Revisions to Radiation Protection

    Science.gov (United States)

    2013-09-30

    ... NUCLEAR REGULATORY COMMISSION [NRC-2012-0268] Revisions to Radiation Protection AGENCY: Nuclear..., ``Radiation Sources,'' Section 12.3 -12.4, ``Radiation Protection Design Features,'' and Section 12.5, ``Operational Radiation Protection Program.'' DATES: The effective date of this Standard Review Plan update is...

  13. Thermoluminescence dating of some Hungarian medieval churches

    International Nuclear Information System (INIS)

    Kasa, I.; Bajnoczy, G.

    1984-01-01

    Thermoluminescence dating of three Hungarian historic churches was performed using the quarz inclusion technique and sup(60)Co gamma irradiation. Quarz grains obtained from the bricks were irradiated and the radiation doses were measured by CaSOsub(4):Dy TL dosemeters. Glow curves of irradiated and non-irradiated samples were also measured. From the results it was concluded that the ages of two churches were 10 and 30 percent less, respectively, than the ages estimated earlier. The age of the third church proved to be correct. (R.P.)

  14. Disinfecting the iPad: evaluating effective methods.

    Science.gov (United States)

    Howell, V; Thoppil, A; Mariyaselvam, M; Jones, R; Young, H; Sharma, S; Blunt, M; Young, P

    2014-06-01

    Tablet computers are increasingly used in healthcare, but they may carry nosocomial pathogens. There are few data available on how to clean an iPad effectively for use in the clinical setting. We aimed to identify the most effective method of decontaminating the Apple iPad, without causing damage, and establish the duration of any residual effect. Following contamination with a microbial broth (meticillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococcus (VRE) and Clostridium difficile), we examined efficacy of iPad disinfection in the laboratory using six different disinfectant wipes: Sani-Cloth CHG 2% (chlorhexidine 2%/alcohol 70%), Clorox, Tristel, Trigene, soap and water, and plain cloth. Following cleaning, iPads were recontaminated to examine residual activity. After 480 Sani-Cloth CHG 2% disinfecting episodes, functional and visual analysis of iPads was performed by blinded subjects. With the exception of Clostridium difficile, Sani-Cloth CHG 2% and Clorox wipes were most effective against MRSA and VRE, and they were significantly better than the Apple-recommended plain cloth (P ≤ 0.001). A substantial residual antimicrobial effect was seen for >6h after wiping the iPad with Sani-Cloth CHG 2% despite repeated recontamination and without further disinfection. The functionality or visual appearance of the iPad was not damaged by repeated use of Sani-Cloth CHG 2% wipes. Sani-Cloth CHG 2% wipes effectively disinfect the iPad against MRSA and VRE, with a residual antibacterial effect and without causing damage. Copyright © 2014 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  15. Dimensional Stability of Color-Changing Irreversible Hydrocolloids after Disinfection

    Directory of Open Access Journals (Sweden)

    Khaledi AAR

    2015-03-01

    Full Text Available Statement of Problem: Disinfection of dental impressions is a weak point in the dental hygiene chain. In addition, dental office personnel and dental technicians are endangered by cross-contamination. Objectives: This study aimed to investigate the dimensional stability of two color-changing irreversible hydrocolloid materials (IH after disinfection with glutaraldehyde. Materials and Methods: In this in vitro study, impressions were made of a master maxillary arch containing three reference inserts on the occlucal surface of the left and right maxillary second molars and in the incisal surface of the maxillary central incisors. Two types of color-changing irreversible hydrocolloid (tetrachrom, cavex were used. Glutaraldehyde 2% was used in two methods of spraying and immersion to disinfect the impressions. The control group was not disinfected. Casts were made of type IV gypsum. The linear dimensional change of the stone casts was measured with a profile projector. For statistical analysis, Kruskall-Wallis and Mann-Witney tests were used (α=0.05. Results: By immersion method, the casts fabricated from tetrachrom were 0.36% larger in the anteroposterior (AP and 0.05% smaller in cross arch (CA dimensions; however, the casts prepared after spraying of tetrachrom were 0.44% larger in the AP and 0.10% smaller in CA dimensions. The casts made from Cavex were 0.05% smaller in the AP and 0.02% smaller in CA dimensions after spraying and 0.01% smaller in the AP and 0.003% smaller in CA dimensions after immersion. Generally there were not significant differences in AP and CA dimensions of the experimental groups compared to the control (p > 0.05. Conclusions: Disinfection of the tested color-changing irreversible hydrocolloids by glutaraldahyde 2% did not compromise the accuracy of the obtained casts.

  16. Effect of gamma rays on fruit storage of some date palm cultivars

    International Nuclear Information System (INIS)

    El Salhy, F.T.A.

    1998-01-01

    This investigation wa conducted on two date groups: Semi-dry date (Amry cultivar) and dry date (Sackoti and Bartamoda cultivars) dates, at the National Center for Radiation Research and Technology (NCRRT), in Cairo, during two successive seasons, 1992 and 1993. The aim of this study is to find out the best alternative method for improving fruit quality as well as prolonging the marketable period of date fruits. Semi-dry date (Amry) fruits were obtained from El-Kourain region, brought from Aswan Governorate. Two hundred and twenty kilograms of fruits from each date group were collected to be used for the different postharvest experiments

  17. Disinfectant choices in veterinary practices, shelters and households : ABCD guidelines on safe and effective disinfection for feline environments

    NARCIS (Netherlands)

    Addie, Diane D; Boucraut-Baralon, Corine; Egberink, Herman; Frymus, Tadeusz; Gruffydd-Jones, Tim; Hartmann, Katrin; Horzinek, Marian C; Hosie, Margaret J; Lloret, Albert; Lutz, Hans; Marsilio, Fulvio; Pennisi, Maria Grazia; Radford, Alan D; Thiry, Etienne; Truyen, Uwe; Möstl, Karin

    OVERVIEW: Regardless of whether a pathogen is viral, bacterial, parasitic, fungal or an emerging unknown, the mainstay of infectious disease control is hygiene, and the cornerstone of good hygiene is effective disinfection. CHALLENGES AND CURRENT CHOICES: Certain pathogens present a challenge to

  18. Disinfection aboard cruise liners and naval units: formation of disinfection by-products using chlorine dioxide in different qualities of drinking water.

    Science.gov (United States)

    Ufermann, Petra; Petersen, Hauke; Exner, Martin

    2011-12-01

    The world-wide deployment of cruise liners and naval units has caused an increased need for the disinfection of drinking water. The main cause for this is the unknown quality of drinking water in foreign harbours--besides the formation of bio-films due to the climatically disadvantageous conditions in the operational area. Water conduits on board are currently disinfected with calcium hypochlorite in case of microbiological contamination. Chemical and physical analyses after disinfection with calcium hypochlorite have shown that organic by-products consisting of trihalomethanes develop in considerable amounts during disinfection. Furthermore, the method is susceptible to handling errors and thus often leads to insufficient disinfection results. Hitherto, the use of other disinfection methods allowed by government regulations, especially chlorine dioxide, is not widely spread. Unlike disinfection with calcium hypochlorite, chlorine dioxide does not lead to the formation of trihalomethanes. Typical disinfection by-products (DBP) are the anions chlorite and chlorate, which are formed in oxidative processes. The formation conditions of these anions have not yet been elucidated. For this reason, the probability of the generation of inorganic by-products after disinfection with chlorine dioxide has been determined, and their occurrence in drinking water on board has been examined with respect to a possible correlation between water quality and the formation of chlorate and chlorite. Therefore, a chromatographic method was developed and validated in order to determine the periodical development of chlorate and chlorite from chorine dioxide in purified water at different pH-values as well as in actual drinking water samples from water conduits on board. The formation of the by-products chlorite and chlorate after disinfection with chlorine dioxide is influenced neither by pH-value nor by chemical properties of the disinfected water. Considering the examined conditions

  19. Luminescence dating of Netherland's sediments

    NARCIS (Netherlands)

    Wallinga, J.; Davids, F.; Dijkmans, J.W.A.

    2007-01-01

    Over the last decades luminescence dating techniques have been developed that allow earth scientists to determine the time of deposition of sediments. In this contribution we revity: 1) the development of the methodology, 2) tests of the reliability of luminescence dating on Netherlands' sediments;

  20. The isotopic dating of crystals

    International Nuclear Information System (INIS)

    Giuliani, G.; Cheilletz, A.

    1995-01-01

    The first part of this work deals with the answer to the question : why are the crystals dated ? Then, some isotopic dating methods are described : U-Th-Pb, K-Ar, 40 Ar/ 39 Ar, Rb-Sr, Sm-Nd, fission traces, carbon 14 methods. Examples concerning emeralds and diamonds are given. (O.L.). 12 refs., 2 figs

  1. The comparison of absolute dating (Radiocarbon dating) and relative dating of Pringapus and Gondosuli temples

    International Nuclear Information System (INIS)

    Faisal, W; Arumbinang, H; Taftazani, A; Widayati, S; Sumiyatno; Suhardi

    1996-01-01

    The absolute dating (radiocarbon, 14 C dating) and relative dating of Pringapus and Gondosuli temples in Temanggung regency (district) of Central Java Province have been carried out. The field sampling was done especially with the purpose to obtain vertical data, so that excavation method was adopted in the case. The main data were the ecofacts of organic habitation such as bones, woods, charcoals, shells, and paper artefacts. The artefacts data were used as a comparison. The comparative data analysis were conducted at Yogyakarta archaeological Department Laboratory, thus included dating of artefacts which were performed according to archaeological analysis procedures, generally based on the attributes attached to the artefacts, whereas the absolute dating of charcoal samples were performed in the Radiocarbon Dating Laboratory at Yogyakarta Nuclear Research Centre. Based on the relative dating of epigraphy content on the andesit rock from Gondosuli Temple which showed the year of 754 Saka or 832 AD, the Pringapus Temple was estimated to be built in the 850 AD. According to the absolute dating (Radiocarbon Dating with delta 13 C and tree ring corrections) the age for Gondosuli temple based on GDS/LU-2/Spit-7 samples is (384 -602) AD and from GDS/LU-2/Spit-8 = (452 - 652) AD. With these significant differences in the results obtained, it can be concluded that culture environment where the sample were collected already existed before the temple was built. Further investigation is still required

  2. The Effect of Disinfection by Spray Atomization on Dimensional Accuracy of Condensation Silicone Impressions

    Directory of Open Access Journals (Sweden)

    Fariba Saleh Saber

    2010-12-01

    Full Text Available Background and aims. The condensation silicone impression materials are available, but there is little knowledge of their accuracy after disinfection. The objective of this study was to evaluate the effect of the disinfection by spray atomization on dimensional accuracy of condensation silicone impressions. Materials and methods. Impressions were made on a stainless steel master model containing a simulated two complete crown preparation with an edentulous space interposed using Spidex® and Rapid® impression materials. 44 impressions were made with each material, of which 16 were disinfected with 5.25% sodium hypochlorite, 16 were disinfected with 10% iodophor and 12 were not disinfected. Three dimensional measurements of working casts, including interpreparation distance, height, and diameter, were calculated using a measuring microscope graduated at 0.001 mm. Dimensional changes (mm between the disinfected and non-disinfected working casts were compared. One-way analysis of variance (ANOVA was employed to analyze the data (α=0.05. Results. Disinfection of each condensation silicone material by spraying atomization with two different disinfectant material resulted in significant change in interpreparation distance (p<0.05. Changes in height and diameter were only significant in Spidex® impressions (p<0.05. Conclusion. Significant changes in the mean dimensions were seen as a result of disinfection by spraying; however, the dimensional changes do not seem great enough to cause critical positional distortion of teeth when fixed partial denture restorations are made.

  3. Resistance to disinfection of a polymicrobial association contaminating the surface of elastomeric dental impressions.

    Science.gov (United States)

    Giammanco, Giovanni M; Melilli, Dario; Rallo, Antonio; Pecorella, Sonia; Mammina, Caterina; Pizzo, Giuseppe

    2009-04-01

    The aim of this study was to evaluate the ability to resist disinfection of a polymicrobial association contaminating the surface of dental impressions obtained with two different elastomers: a polyether (Impregum) and an addition-polymerized silicone (Elite). Impressions were contaminated with a mixture of three biofilm-forming microorganisms (Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans) and disinfected immediately after contamination, or after microbial layers were allowed to develop during a six-hour storage. Two commercial disinfectants were tested: MD 520 containing 0.5% glutaraldehyde and Sterigum Powder without glutaraldehyde. Residual contamination was recovered by mechanical rinsing immediately after disinfection and after a six-hour storage of disinfected impressions, and assessed by colony counting. Both disinfectants tested were shown to be effective in reducing the microbial presence on the impression materials, achieving at least a 102 reduction of microbial counts compared to water rinsing. However, Sterigum was generally less effective on the Elite elastomer and could not grant disinfection on six-hour aged P. aeruginosa and C. albicans microbial layers. The results of this study suggest that the materials used for the impressions influence the efficacy of disinfection. Disinfectants should be tested according to conditions encountered in everyday clinical practice and the need for immediate disinfection of impressions should be clearly indicated by manufacturers.

  4. In-Use Evaluation of Peracetic Acid for High-Level Disinfection of Endoscopes.

    Science.gov (United States)

    Chenjiao, Wu; Hongyan, Zhang; Qing, Gu; Xiaoqi, Zhong; Liying, Gu; Ying, Fang

    2016-01-01

    Many high-level disinfectants have been used for disinfection of endoscopes such as 2% glutaraldehyde (GA), 0.55% ortho-phthalaldehyde (OPA), and peracetic acid (PAA). Both GA and OPA are widely used in disinfection of endoscopes and have been previously discussed, but there is little research on the practical use of PAA as an endoscope disinfectant. An experimental model of a flexible gastrointestinal endoscope being contaminated with 9 strains of microorganism was designed. After the cleaning and disinfecting procedure was completed, we evaluated the biocidal activity (850 ppm PAA, 2% GA, and 0.55% OPA) on our flexible gastrointestinal endoscope model. We also evaluated sterilization effectiveness of PAA on other bacteria, including some antibiotic-resistant bacteria (methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, and Clostridium difficile). The residual bacterial colony count number of the PAA-disinfected endoscope was significantly lower than that of the GA- and OPA-disinfected endoscopes. The biocidal effect and efficiency of the endoscope disinfection by PAA appeared to be better than either the GA- or OPA-disinfected endoscope. PAA has demonstrated a good sterilization effect on other bacterial species; of particular note are common antibiotic-resistant bacteria such as methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, and Clostridium difficile. The results of this study demonstrate that PAA is a fast and effective high-level disinfectant for use in the reprocessing of flexible endoscopes.

  5. Toxic impact of bromide and iodide on drinking water disinfected with chlorine or chloramines.

    Science.gov (United States)

    Yang, Yang; Komaki, Yukako; Kimura, Susana Y; Hu, Hong-Ying; Wagner, Elizabeth D; Mariñas, Benito J; Plewa, Michael J

    2014-10-21

    Disinfectants inactivate pathogens in source water; however, they also react with organic matter and bromide/iodide to form disinfection byproducts (DBPs). Although only a few DBP classes have been systematically analyzed for toxicity, iodinated and brominated DBPs tend to be the most toxic. The objectives of this research were (1) to determine if monochloramine (NH2Cl) disinfection generated drinking water with less toxicity than water disinfected with free chlorine (HOCl) and (2) to determine the impact of added bromide and iodide in conjunction with HOCl or NH2Cl disinfection on mammalian cell cytotoxicity and genomic DNA damage induction. Water disinfected with chlorine was less cytotoxic but more genotoxic than water disinfected with chloramine. For both disinfectants, the addition of Br(-) and I(-) increased cytotoxicity and genotoxicity with a greater response observed with NH2Cl disinfection. Both cytotoxicity and genotoxicity were highly correlated with TOBr and TOI. However, toxicity was weakly and inversely correlated with TOCl. Thus, the forcing agents for cytotoxicity and genotoxicity were the generation of brominated and iodinated DBPs rather than the formation of chlorinated DBPs. Disinfection practices need careful consideration especially when using source waters containing elevated bromide and iodide.

  6. Observations on Salmonella contamination of commercial duck farms before and after cleaning and disinfection.

    Science.gov (United States)

    Martelli, Francesca; Gosling, Rebecca J; Callaby, Rebecca; Davies, Rob

    2017-04-01

    In the European Union, statutory control of Salmonella is in place in the chicken and turkey sectors, but not in the duck sector. In this study, 14 Salmonella-positive duck farms were sampled before and after cleaning and disinfection, and once the houses had been restocked with a new flock. The cleaning and disinfection programmes used were subdivided into two main categories: ones in which a final formaldehyde disinfection step was included (1) and ones in which it was not included (2). Several types of samples were collected during the study, and faecal samples were those more frequently positive (62% of faecal samples were positive for Salmonella in comparison to 2-23% of samples from all the other sample categories) (P cleaning and disinfection programme used, there was a statistically significant (P cleaning and disinfection (41.1%) and after cleaning and disinfection (3.1%). After restocking, the number of Salmonella-positive samples increased significantly (P disinfection programme 1 was used were 5.34 times less likely to have samples positive for Salmonella after cleaning and disinfection than farms which implemented programme 2. Formaldehyde acts effectively against Salmonella even in the presence of some residual organic matter. Limited residual contamination on farms after cleaning and disinfection represents a risk of infection for young ducklings, and thorough cleaning and disinfection procedures should be implemented to reduce the carry-over of infection between flocks.

  7. Resistance of Pseudomonas aeruginosa isolates to hydrogel contact lens disinfection correlates with cytotoxic activity.

    Science.gov (United States)

    Lakkis, C; Fleiszig, S M

    2001-04-01

    One of the most common pathogens in infection of hydrogel contact lens wearers is Pseudomonas aeruginosa, which can gain access to the eye via contamination of the lens, lens case, and lens care solutions. Only one strain per species is used in current regulatory testing for the marketing of chemical contact lens disinfectants. The aim of this study was to determine whether P. aeruginosa strains vary in their susceptibility to hydrogel contact lens disinfectants. A method for rapidly screening bacterial susceptibility to contact lens disinfectants was developed, based on measurement of the MIC. The susceptibility of 35 P. aeruginosa isolates to two chemical disinfectants was found to vary among strains. MICs ranged from 6.25 to 100% for both disinfectants at 37 degrees C, and a number of strains were not inhibited by a 100% disinfectant concentration in the lens case environment at room temperature (22 degrees C). Resistance to disinfection appeared to be an inherent rather than acquired trait, since some resistant strains had been isolated prior to the introduction of the disinfectants and some susceptible P. aeruginosa strains could not be made more resistant by repeated disinfectant exposure. A number of P. aeruginosa strains which were comparatively more resistant to short-term disinfectant exposure also demonstrated the ability to grow to levels above the initial inoculum in one chemical disinfectant after long-term (24 to 48 h) disinfectant exposure. Resistance was correlated with acute cytotoxic activity toward corneal epithelial cells and with exsA, which encodes a protein that regulates cytotoxicity via a complex type III secretion system. These results suggest that chemical disinfection solutions may select for contamination with cytotoxic strains. Further investigation of the mechanisms and factors responsible for resistance may also lead to strategies for reducing adverse responses to contact lens wear.

  8. Influence of Irradiated Chitosan on Growth and Flower Quality of Gladiolus at Different Sowing Dates and Synthesis of Radiation Cross-Linked Poly(Acrylic Acid) Hydrogel for Agriculture Applications. Chapter 14

    Energy Technology Data Exchange (ETDEWEB)

    Habib, U.; Ahmed, N. [Department of Horticulture, PMAS Arid Agriculture University, Rawalpindi (Pakistan); Zahid, S.; Yashin, T., E-mail: yasintariq@yahoo.com [Pakistan Institute of Engineering and Applied Sciences, Islamabad (Pakistan)

    2014-07-15

    The plant growth promoter activity of irradiated chitosan on Gladiolus hortulanus cv. Amsterdam was studied. Chitosan was applied in the form of foliar spray at third leaf stage. Corms were sown at three different dates with 15-day intervals. Data on several parameters such as survival percentage, leaf area, plant height, number of florets per spike, and vase life were collected. Chitosan-treated plants showed superior results as compared to the control samples. Acrylic acid-based superabsorbent hydrogel was prepared using phenyltriethoxysilane (PTES) as cross-linker. Different amounts of PTES were incorporated and irradiated at different doses of up to a maximum of 30 kGy. The cross-linked acrylic acid showed hydrogel properties, and its swelling kinetics, gel fraction, and equilibrium degree of swelling (EDS) were studied. The swelling of hydrogel was also affected by pH, ionic strength, and temperature. These hydrogels can be further explored as a super water absorbent material in semi-arid and drought prone areas. (author)

  9. Irradiation disinfestation and decontamination of Iranian dates and pistachio nuts

    Science.gov (United States)

    Zare, Z.; Sayhoon, M.; Maghsoudi, V.

    1993-07-01

    Decontamination and disinfestation effect of gamma radiation on microflora of dates and artificially infested packed dates (Mazafaty, Zard and Sayer variety) with Tribolium Confusum, Oryzaephilus Surinamensis and Ephestia Cautella in different stages studied. Treatment with 0.75 kGy dose of gamma radiation leads to complete and satisfactory insect disinfestation of dates during a storage period of 9, 20 and 35 days. This study shows that microbiological quality of Mazafaty dates can be significantly improved when they have received a gamma radiation dose of 2.5 kGy. Finally the sugar content of irradiated and unirradiated samples have compared. In this study, we have also used gamma radiation treatment for the control of microbial spoilage of pistachio nuts caused by toxigenic Aspergillus Flavus. The first sequence involved, the freshly harvested pistachio nuts inoculated with A. Flavus spores and exposed to radiation treatment, then retention of samples in a environmental chamber, set at temperature of 15-20 C at 75-80% relative humidity and stored for six months. In the second sequence during the storage period the changes in protein, lipid content of pistachio nuts have analyzed.

  10. Irradiation disinfestation and decontamination of Iranian dates and pistachio nuts

    International Nuclear Information System (INIS)

    Zare, Z.; Sayhoon, M.; Maghsoudi, V.

    1993-01-01

    The decontamination and disinfestation effect of gamma radiation on the microflora of dates and artificially infested packed dates was studied. Treatment with 0.75 kGy dose of gamma radiation leads to complete and satisfactory insect disinfestation of dates during a storage period of 9, 20 and 35 days. This study shows that the microbiological quality of Mazafaty dates can be significantly improved when they received a gamma radiation dose of 2.5 kGy. The sugar content of irradiated and unirradiated samples have been compared. In this study, we also used gamma radiation treatment for the control of microbial spoilage of pistachio nuts caused by the toxogenic Aspergillus flavus. The freshly harvested pistachio nuts were inoculated with A. flavus spores and exposed to radiation treatment, then samples were retained in an environmental chamber, set at a temperature of 15-20 C at 75-80% relative humidity and stored for six months. In the second batch during the storage period the changes in protein, lipid content of pistachio nuts were analysed. (author)

  11. Radiation exposure and radiation protection

    International Nuclear Information System (INIS)

    Heuck, F.; Scherer, E.

    1985-01-01

    The present volume is devoted to the radiation hazards and the protective measures which can be taken. It describes the current state of knowledge on the changes which exposure to ionizing rays and other forms of physical energy can induce in organs and tissues, in the functional units and systems of the organism. Special attention is paid to general cellular radiation biology and radiation pathology and to general questions of the biological effects of densely ionizing particle radiation, in order to achieve a better all-round understanding of the effects of radiation on the living organism. Aside from the overviews dealing with the effects of radiation on the abdominal organs, urinary tract, lungs, cerebral and nervous tissue, bones, and skin, the discussion continues with the lymphatic system, the bone marrow as a bloodforming organ, and the various phases of reaction in the reproductive organs, including damage and subsequent regeneration. A special section deals with environmental radiation hazards, including exposure to natural radiation and the dangers of working with radioactive substances, and examines radiation catastrophes from the medical point of view. Not only reactor accidents are covered, but also nuclear explosions, with exhaustive discussion of possible damage and treatment. The state of knowledge on chemical protection against radiation is reviewed in detail. Finally, there is thorough treatment of the mechanism of the substances used for protection against radiation damage in man and of experience concerning this subject to date. In the final section of the book the problems of combined radiotherapy are discussed. The improvement in the efficacy of tumor radiotherapy by means of heavy particles is elucidated, and the significance of the efficacy of tumor therapy using electron-affinitive substances is explained. There is also discussion of the simultaneous use of radiation and pharmaceuticals in the treatment of tumors. (orig./MG) [de

  12. Combining sun-based technologies (microalgae and solar disinfection) for urban wastewater regeneration.

    Science.gov (United States)

    Gutiérrez-Alfaro, Sergio; Rueda-Márquez, Juan J; Perales, José A; Manzano, Manuel A

    2018-04-01

    Solar disinfection (SODIS) of urban wastewater can be a suitable technology for improving the microbiological quality of reclaimed water as a complement to other extensive and environmentally friendly technologies such as microalgae biotreatment. The objective of this work is to evaluate the feasibility of incorporating the SODIS technology at the end of a pilot scale urban wastewater treatment plant (WWTP) where the processes are based on microalgae biotechnology and comprising three Upflow Anaerobic Sludge Blanket (UASB, 20m 3 each one) reactor, six High Rate Algal Ponds (HRAP, 32m 2 each one), and a Dissolved Air Flotation (DAF, 1m 3 ) unit. E. coli concentration was monitored at the effluent of the different units (UASB, HRAP, DAF) of the pilot WWTP. The efficiency of the SODIS process was studied for the inactivation of three of the commonly employed indicator microorganisms (Escherichia coli, Enterococcus spp. and Clostridium perfringens) using a compound parabolic collector (CPC) for five months under various conditions of irradiance and temperature. E. coli and Enterococcus spp. were more effectively disinfected by the SODIS unit (2.9 and 2.5 logarithms of reduction on average, respectively) than by the HRAP (2 and 1.1) or the DAF (0.9 and 0.1). On the contrary, the DAF technology achieved better reduction rates of C. perfringens (1.7) than the SODIS (0.9) and the HRAP (0.1). No regrowth of any microorganisms was detected during dark storage after the SODIS treatment. Incorporating a SODIS unit after the non-conventional WWTP processes substantially increases the possibilities for reuse of the treated water after receiving a cumulative UV radiation dose of 25W·h/m 2 (50min of normalized time of solar illumination). The surface requirement of the SODIS equipment would be 3.5 times smaller than the HRAP's surface. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Integration of an innovative biological treatment with physical or chemical disinfection for wastewater reuse.

    Science.gov (United States)

    De Sanctis, Marco; Del Moro, Guido; Levantesi, Caterina; Luprano, Maria Laura; Di Iaconi, Claudio

    2016-02-01

    In the present paper, the effectiveness of a Sequencing Batch Biofilter Granular Reactor (SBBGR) and its integration with different disinfection strategies (UV irradiation, peracetic acid) for producing an effluent suitable for agricultural use was evaluated. The plant treated raw domestic sewage, and its performances were evaluated in terms of the removal efficiency of a wide group of physical, chemical and microbiological parameters. The SBBGR resulted really efficient in removing suspended solids, COD and nitrogen with an average effluent concentration of 5, 32 and 10 mg/L, respectively. Lower removal efficiency was observed for phosphorus with an average concentration in the effluent of 3 mg/L. Plant effluent was also characterized by an average electrical conductivity and sodium adsorption ratio of 680 μS/cm and 2.9, respectively. Therefore, according to these gross parameters, the SBBGR effluent was conformed to the national standards required in Italy for agricultural reuse. Moreover, disinfection performances of the SBBGR was higher than that of conventional municipal wastewater treatment plants and met the quality criteria suggested by WHO (Escherichia colidisinfection processes (UV and peracetic acid) resulted very effective for total coliforms, E. coli and somatic coliphages. In particular, a UV radiation and peracetic acid doses of 40 mJ/cm(2) and 1 mg/L respectively reduced E. coli content in the effluent below the limit for agricultural reuse in Italy (10 CFU/100 mL). Conversely, they were both ineffective on C.perfringens spores. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Hepatitis A Virus Disinfection in Water by Solar Photo-Fenton Systems.

    Science.gov (United States)

    Polo, David; García-Fernández, Irene; Fernández-Ibañez, Pilar; Romalde, Jesús L

    2018-06-01

    This study evaluates and compares the effectiveness of solar photo-Fenton systems for the inactivation of hepatitis A virus (HAV) in water. The effect of solar irradiance, dark- Fenton reaction and three different reactant concentrations (2.5/5, 5/10 and 10/20 mg/L of Fe 2+ /H 2 O 2 ) on the photo-Fenton process were tested in glass bottle reactors (200 mL) during 6 h under natural sunlight. Disinfection kinetics were determined both by RT-qPCR and infectivity assays. Mean water temperatures ranged from 25 to 27.3 °C, with a maximum local noon UV irradiances of 22.36 W/m 2 . Photo-Fenton systems yielded increased viral reduction rates in comparison with the isolated effect under the Fenton reaction in darkness (negligible viral reduction) or the solar radiation (0.25 Log of RNA reduction). With the highest concentration employed (10-20 mg/L Fe 2+ -H 2 O 2 ), an average RNA reduction rate of ~ 1.8 Log (initial concentration of 10 5 pfu/mL) and a reduction of 80% in the infectivity capacity were reached. Results showed a strong synergistic effect between Fe 2+ /H 2 O 2 and sunlight, demonstrating that significant disinfection rates of HAV under photo-Fenton systems may occur with relatively higher efficiency at middle environmental temperatures and without the need for an energy-intensive light source.

  15. AHP 47: A NIGHT DATE

    Directory of Open Access Journals (Sweden)

    Phun tshogs dbang rgyal ཕུན་ཚོགས་དབང་རྒྱལ།

    2017-04-01

    Full Text Available The author was born in 1993 in Ska chung (Gaqun Village, Nyin mtha' (Ningmute Township, Rma lho (Henan Mongolian Autonomous County, Rma lho (Huangnan Tibetan Autonomous Prefecture, Mtsho sngon (Qinghai Province, PR China. Night dating was popular for teenage boys some years ago. They rode horses and yaks when they went night dating. They generally rode yaks, because horses were important for their families and used for such important tasks as pursuing bandits and going to the county town for grain and supplies. An early experience with night dating is described.

  16. Study on a New Ultraviolet Sterilizer to the Surface Disinfection of the Ultrasound Probe.

    Science.gov (United States)

    Chen, Gui Qiu; Chen, Yu Hao; Yi, Liang; Yin, Jin; Gao, Qiong; Song, Jiang Nan; Li, Shi Kang; Chen, Pei Hou; Guo, Gui Ping

    2018-02-01

    We studied the disinfection effect of a new ultraviolet (UV) sterilizer and its utilization on ultrasound probe surfaces. Carrier quantitative germicidal tests, simulated on-the-spot trials, and organic substance influence tests were used to carry out experimental observation. Artificially infected probes were disinfected using the sterilizer or a germicidal lamp for comparison. The total number and types of bacteria were determined and identified. Our results demonstrated the sterilizer had the best disinfection effect among three different disinfection methods in hospital. The sterilizer has been used in a hospital setting for 2 years with no notable damage to the ultrasound probe instrument. It has the advantages of fast disinfection, high disinfection effect, and good compatibility with the ultrasound instrument, worthy of being a promoted application in medical institutions. Copyright © 2018 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  17. Activity of disinfectants against foodborne pathogens in suspension and adhered to stainless steel surfaces

    Directory of Open Access Journals (Sweden)

    Tatiane Karen Cabeça

    2012-09-01

    Full Text Available The purpose of this study was to investigate and compare the efficacy of various disinfectants on planktonic cells and biofilm cells of Listeria monocytogenes, Staphylococcus aureus and Escherichia coli. Numbers of viable biofilm cells decreased after treatment with all tested disinfectants (iodine, biguanide, quaternary ammonium compounds, peracetic acid and sodium hypochlorite. Sodium hypochlorite was the most effective disinfectant against biofilm cells, while biguanide was the least effective. Scanning electron microscopy observations revealed that cells adhered on stainless steel surface after treatment with the disinfectants. No viable planktonic cells were observed after treatment with the same disinfectants. Based on our findings, we concluded that biofilm cells might be more resistant to disinfectants than plancktonic cells.

  18. Thermal disinfection of hotels, hospitals, and athletic venues hot water distribution systems contaminated by Legionella species.

    Science.gov (United States)

    Mouchtouri, Varvara; Velonakis, Emmanuel; Hadjichristodoulou, Christos

    2007-11-01

    Legionella spp. (> or = 500 cfu liter(-1)) were detected in 92 of 497 water distribution systems (WDS) examined. Thermal disinfection was applied at 33 WDS. After the first and second application of the disinfection procedure, 15 (45.4%) and 3 (9%) positive for remedial actions WDS were found, respectively. Legionella pneumophila was more resistant to thermal disinfection than Legionella non-pneumophila spp. (relative risk [RR]=5.4, 95% confidence intervals [CI]=1-35). WDS of hotels with oil heater were more easily disinfected than those with electrical or solar heater (RR=0.4 95% CI=0.2-0.8). Thermal disinfection seems not to be efficient enough to eliminate legionellae, unless repeatedly applied and in combination with extended heat flushing, and faucets chlorine disinfection.

  19. Chemical surface disinfection of eggs of Baltic cod, Gadus morhua L

    DEFF Research Database (Denmark)

    Overton, J L; Bruun, Morten Sichlau; Dalsgaard, Inger

    2010-01-01

    The effect of two disinfectants on eggs and larvae of Baltic cod, Gadus morhua, was investigated. The eggs were disinfected for 10 min using various concentrations of either glutaraldehyde (100, 200, 400, 600 and 800 mg L−1) or iodophor (10, 50, 100 and 150 mg L−1), 1–4-days post......-fertilization. Bactericidal effect of disinfection, survival to hatching, hatching success and larval abnormalities were assessed. Larval survival was recorded at 5-, 10- and 15-days post-hatch (dph). Although Baltic cod eggs have an unusually thin chorion, they could tolerate surface disinfection. A reduction in bacterial...... growth was observed with increased concentrations of disinfectant (3.0 × 107–1.6 × 101 CFU mL−1). Abnormalities in newly hatched larvae were not related to disinfection. Survival of the yolk sac larvae was significantly better for eggs treated with 400 mg L−1 glutaraldehyde for 10 min at 10 and 15 dph...

  20. Laboratory and field investigation of chemical disinfection of combined sewer overflow in Copenhagen area

    DEFF Research Database (Denmark)

    Chhetri, Ravi Kumar; Thornberg, Dines; Berner, Jesper

    We investigated the possibility to apply performic acid (PFA) and peracetic acid (PAA) for disinfection of combined sewer overflow (CSO) in existing CSO management infrastructures. The disinfection power of PFA and PAA to Escherichia coli (E. coli) and enterococcus were studied in batch scale...... and pre-field experiment. In batch scale experiment 2.5 mg·L -1 PAA removed around 4 log unit of E. coli and enterococcus from CSO with long contact time. Removal of E. coli and enterococcus from CSO were always around or above 3 log unit using 2-4 mg·L -1 PFA with short contact time in batch scale...... and pre-field experiment. There were no toxicological effect measured by Vibrio fischeri when CSO was disinfected with PFA, slight toxicological effect was observed on CSO disinfected with PAA. When the design for PFA based disinfection was applied to CSO collected from an authentic event. Disinfection...

  1. Microbial electrolytic disinfection process for highly efficient Escherichia coli inactivation

    DEFF Research Database (Denmark)

    Zhou, Shaofeng; Huang, Shaobin; Li, Xiaohu

    2018-01-01

    extensively studied for recalcitrant organics removal, its application potential towards water disinfection (e.g., inactivation of pathogens) is still unknown. This study investigated the inactivation of Escherichia coli in a microbial electrolysis cell based bio-electro-Fenton system (renamed as microbial......Water quality deterioration caused by a wide variety of recalcitrant organics and pathogenic microorganisms has become a serious concern worldwide. Bio-electro-Fenton systems have been considered as cost-effective and highly efficient water treatment platform technology. While it has been......]OH was identified as one potential mechanism for disinfection. This study successfully demonstrated the feasibility of bio-electro-Fenton process for pathogens inactivation, which offers insight for the future development of sustainable, efficient, and cost-effective biological water treatment technology....

  2. Surface Dielectric Barrier Discharge Jet for Skin Disinfection

    Science.gov (United States)

    Creyghton, Yves; Meijer, Rogier; Verweij, Paul; van der Zanden, Frank; Leenders, Paul

    A consortium consisting of the research institute TNO, the medical ­university and hospital St Radboud and two industrial enterprises is working on a non-thermal plasma treatment method for hand disinfection. The group is seeking for cooperation, in particular in the field of validation methods and potential ­standardization for plasma based disinfection procedures. The present paper describes technical progress in plasma source development together with initial microbiological data. Particular properties of the sheet shaped plasma volume are the possibility of treating large irregular surfaces in a short period of time, effective plasma produced species transfer to the surface together with high controllability of the nature of plasma species by means of temperature conditioning.

  3. Chlorine dioxine DBPs (disinfection by-products in drinking water

    Directory of Open Access Journals (Sweden)

    C. Lasagna

    2013-01-01

    Full Text Available Since the 1970s it has been well known that, though water for human consumption is generally disinfected before being distributed along the network, the use of chemicals results in the formation of many different Disinfection By-Products (DBPs. In the case of chlorine dioxide, the most important and represented DBPs are chlorite and chlorate: after an introduction concerning the current Italian regulation on this subject, in the experimental part the results of a 7-year minitoring campaign, concerning water of different origin collected from taps in various Italian regions, are shown. The analytical technique used for the determination of chlorite and chlorate was Ion Chromatography. The result obtained are finally discussed.

  4. Dose requirements for UVC disinfection of catheter biofilms

    DEFF Research Database (Denmark)

    Bak, Jimmy; Ladefoged, Søren D.; Tvede, Michael

    2009-01-01

    Bacterial biofilms on permanent catheters are the major sources of infection. Exposure to ultraviolet-C (UVC) light has been proposed as a method for disinfecting the inner surface of catheters. Specification of a UVC-based device for in vivo disinfection is based on the knowledge of the required...... doses to kill catheter biofilm. Given these doses and the power of available UVC light sources, calculation of the necessary treatment times is then possible. To determine the required doses, contaminated urinary catheters were used as test samples and UVC treated in vitro. Patient catheters (n = 67......) were collected and cut into segments of equal size and treated with various UVC doses. After treatment, the biofilm was removed by scraping and quantified by counting colony forming units. Percentage killing rates were determined by calculating ratios between UVC-treated samples and controls (no UVC...

  5. Sludge disinfection by combined treatment of bleaching powder and irradiation

    International Nuclear Information System (INIS)

    Harsoyo

    1987-01-01

    Sludge disinfection by combined treatment of bleaching powder and irradiation. Disinfection of sludge by combined treatment of bleaching powder and irradiation has been investigated. Sludge were obtained from water and waste sanitation department (Dinas Kebersihan) DKI located at Kebon Nanas, Jakarta. Sludge were mixed with bleaching powder at the concentration of 0, 10 and 20 mg/l and then irradiated in multipurpose panoramic batch irradiator (PANBIT) with doses of 2, 4, 6, 8, and 10 kGy and a dose rate 9 kGy/h. The reducing colony form unit caused by the combined treatment depend on type bacteria observed in sludge. Pathogenic bacteria as Clostridium still survive at a dose of 10 kGy on sludge containing 20 mg/l bleaching powder, but Salmonella, Shigella, and Vibrio were not detected in this experiment, neither in the control nor in the irradiated samples. (author). 14 refs.; 4 figs

  6. Solar disinfection of drinking water and oral rehydration solutions

    Energy Technology Data Exchange (ETDEWEB)

    Acra, A; Raffoul, Z; Karahagopian, Y

    1984-01-01

    This document provides concise information on oral rehydration therapy for the control of diarrheal diseases in developing countries; however, the main emphasis has been placed on the disinfection of oral rehydration solutions, or the water used in their preparation, as achieved by exposure to sunlight in transparent containers. The fundamental principles of solar energy are presented as well as studies which demonstrate the efficacy of the method. 2 figures, 6 tables.

  7. Inactivation Effect of Antibiotic-Resistant Gene Using Chlorine Disinfection

    Directory of Open Access Journals (Sweden)

    Takashi Furukawa

    2017-07-01

    Full Text Available The aim of this study was to elucidate the inactivation effects on the antibiotic-resistance gene (vanA of vancomycin-resistant enterococci (VRE using chlorination, a disinfection method widely used in various water treatment facilities. Suspensions of VRE were prepared by adding VRE to phosphate-buffered saline, or the sterilized secondary effluent of a wastewater treatment plant. The inactivation experiments were carried out at several chlorine concentrations and stirring time. Enterococci concentration and presence of vanA were determined. The enterococci concentration decreased as chlorine concentrations and stirring times increased, with more than 7.0 log reduction occurring under the following conditions: 40 min stirring at 0.5 mg Cl2/L, 20 min stirring at 1.0 mg Cl2/L, and 3 min stirring at 3.0 mg Cl2/L. In the inactivation experiment using VRE suspended in secondary effluent, the culturable enterococci required much higher chlorine concentration and longer treatment time for complete disinfection than the cases of suspension of VRE. However, vanA was detected in all chlorinated suspensions of VRE, even in samples where no enterococcal colonies were present on the medium agar plate. The chlorine disinfection was not able to destroy antibiotic-resistance genes, though it can inactivate and decrease bacterial counts of antibiotic-resistant bacteria (ARB. Therefore, it was suggested that remaining ARB and/or antibiotic-resistance gene in inactivated bacterial cells after chlorine disinfection tank could be discharged into water environments.

  8. Iodine Disinfection in the Use of Individual Water Purification Devices

    Science.gov (United States)

    2006-03-01

    Effect of Resin Disinfectants-I3 and –I5 on Giardia muris and Giardia lamblia. Applied and Environmental Microbiology, 46(5), 965-969. 24. AWWA... Giardia or Cryptosporidium). Iodine-using IWPDs meeting these standards are considered effective against disease causing bacteria, viruses, and...CT = 65 mg-min/L) for a 2-log inactivation of E. histolytica cysts (references 9 and 10). Another study using Giardia cysts showed CT’s up to 3

  9. Automation of air disinfection and lighting in agricultural buildings

    Directory of Open Access Journals (Sweden)

    L. Yu. Yuferev

    2017-01-01

    Full Text Available The article describes the urgency of this problem and modern ways of its solving. Modern disinfection and lighting systems are not developed enough. The authors proposed to automate the system of disinfection, dust removal and lighting in the farm building. We developed algorithm on the basis of which the universal program in the programming language C ++ was written. Assembled the microprocessor set ARDUINO. The program is included in the microprocessor ATMEGA, which is part of ARDUINO. As a basis for the disinfection system, a two-component ARUF device was used, which includes two decontaminating components: an ultraviolet lamp and an aerosol dispenser. Each of the algorithms (lighting and disinfection consists of 3 parts: data collection and analysis, control, data output to the display. The sequence of 3 parts is 1 cycle, then it repeated. In the first part on the basis of indications of sensors assignment to variables of some values was carried out. In the second part, based on the values of the variables, the decontamination and lighting devices are controlled. In the third part due to changing the screen number, variable, it is possible to switch the display and view the status of the installation and external parameters. The program, written on the basis of algorithms, is universal and suitable for almost any poultry and livestock buildings. All parameters (the time of the beginning and completion of the ARUV operation within 24 hours, the daily time of the illumination of a certain cycle, the maximum and minimum humidity, the duration of each cycle used for control and management are variables. Operator can set the items using the display in the menu.

  10. Dating the humans by radiocarbon

    International Nuclear Information System (INIS)

    Fedi, M.E.

    2011-01-01

    Radiocarbon has become a very powerful tool used for dating. This paper deals with a specific application of 1 4C i.e. dating of humans. Attention is focused on those aspects that, if neglected, might lead to a misinterpretation of the results or to an unsatisfying accuracy of the measurement. After a brief description of the main principles on which the radiocarbon method is based and of Accelerator Mass Spectrometry, examples taken from the research activity of INFN-LABEC (Laboratorio di Tecniche Nucleari per I Beni Culturali) in Florence are presented. The case of the relic of St. Francis represents an example of dating not directly human remains but other objects that can be associated to them. The case of two burials from the archaeological area of Baratti-Populonia, in Tuscany, gives the possibility to show the importance of estimating the human palaeodiet when dating bone samples.

  11. Suitability of electrolyzed oxidizing water for the disinfection of hard surfaces and equipment in radiology

    OpenAIRE

    Pintaric, Robert; Matela, Joze; Pintaric, Stefan

    2015-01-01

    Background Hospitals are faced with increasingly resistant strains of micro-organisms. When it comes to disinfection, individual parts of electronic equipment of angiology diagnostics such as patient couches of computer tomography (CT) and magnetic resonance imaging (MRI) scanners prove to be very hard to disinfect. Disinfectants of choice are therefore expected to possess properties such as rapid, residue-free action without any damaging effect on the sensitive electronic equipment. This pap...

  12. Exposure characteristics of familial cases of lung injury associated with the use of humidifier disinfectants

    OpenAIRE

    Park, Donguk; Leem, Jonghan; Lee, Kyoungmu; Lim, Heungkyu; Choi, Yeyong; Ahn, Jong-Ju; Lim, Sinye; Park, Jeongim; Choi, Kyungho; Lee, Naroo; Jung, Hyejung; Ha, Jongsik; Paek, Domyung

    2014-01-01

    Background This study describes 17 families with 38 lung injury patients (14 males, 24 females; 22 preschool-age children less than six years of age and 16 individuals of 13–50 years) who used disinfectant added to humidifiers in the home. Methods Clinical examination and humidifier disinfectant-use histories were taken, and a thorough home investigation was performed to assess exposure to humidifier disinfectant. Results Nine of the patients (three pregnant females, six preschool-age childre...

  13. Association of high-level humidifier disinfectant exposure with lung injury in preschool children.

    Science.gov (United States)

    Park, Dong-Uk; Ryu, Seung-Hun; Roh, Hyun-Suk; Lee, Eun; Cho, Hyun-Ju; Yoon, Jisun; Lee, So-Yeon; Cho, Young Ah; Do, Kyung-Hyun; Hong, Soo-Jong

    2018-03-01

    Children aged ≤6years reportedly account for 52% of victims of humidifier disinfectant-associated lung injuries. To evaluate the association of humidifier disinfectants with lung injury risk among children aged ≤6years. Patients with humidifier disinfectant-associated lung injuries (n=214) who were clinically evaluated to have a definite (n=108), probable (n=49), or possible (n=57) association with humidifier disinfectants as well as control patients (n=123) with lung injury deemed unlikely to be associated with humidifier disinfectant use were evaluated to determine factors associated with increased risk of humidifier disinfectant-associated lung injury using unconditional multiple logistic regression analysis. For estimated airborne humidifier disinfectant concentrations, risk of humidifier disinfectant-associated lung injury increased ≥two-fold in a dose-dependent manner in the highest quartile (Q4, 135-1443μg/m 3 ) compared with that in the lowest quartile (Q1, ≤33μg/m 3 ). Registered patients using more than two humidifier disinfectant brands were at an increased risk of humidifier disinfectant-associated lung injury (adjusted OR, 2.2; 95% confidence interval, 1.3-3.8) compared with those using only one brand. With respect to the duration of humidifier disinfectant use, risk of humidifier disinfectant-associated lung injury increased ≥two-fold in the lowest quartile (≤5months) compared with that in the highest quartile (≥14months; adjusted OR 0.3; 95% confidence interval, 0.2-0.6). Younger children are more vulnerable to HDLI when exposed to HD chemicals within short period in early life. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Antiviral activity of a novel composition of peracetic acid disinfectant on parvoviruses

    Science.gov (United States)

    Dagher, Fadi; Jiang, Jun; Tijssen, Peter; Laliberté, Jean-François

    2017-01-01

    Porcine parvoviruses (PPV) are known to be particularly resistant to many disinfectants used to control other non-enveloped viruses. However, effective disinfectants used against PPV are harsh and corrosive to animal health facilities and the environment. We propose a noncorrosive “green” disinfectant that generates peracetic acid in-situ and is capable of inactivating PPV completely at a 1% concentration for a 10-minute contact time. PMID:28154460

  15. Radiocarbon dating of lake sediments

    OpenAIRE

    Pocevičius, Matas

    2016-01-01

    Matas Pocevičius, Radiocarbon dating of lake sediments, bachelor thesis, Vilnius University, Faculty of Physics, Department of General Physics and Spectroscopy, physics, Vilnius, 45 p., 2016. The aim of this study is to evaluate the possibility of radiocarbon dating application for Tapeliai lake bottom sediments. The literature review discusses topics related to accelerator mass spectrometry, principles of radiocarbon formation, importance of nuclear fallout for 14C, possible applications of ...

  16. Antifungal efficacy of hydrogen peroxide in dental unit waterline disinfection.

    Science.gov (United States)

    Szymańska, Jolanta

    2006-01-01

    The concentration and composition of fungal flora in dental unit waterlines (DUWL) were evaluated. For this purpose, water samples from unit reservoirs and high-speed handpieces, and biofilm samples from the waterline walls from units were collected. Subsequently, analogous samples from DUWL were taken before and after disinfection using agent containing hydrogen peroxide. In the examined samples, the yeast-like fungi Candida albicans and Candida curvata were found. The following species of mould were also identified: Aspergillus amstelodami, Aspergillus fumigatus, Aspergillus glaucus group, Aspergillus (=Eurotium herbariorum) repens, Citromyces spp., Geotrichum candidum, Penicillium (glabrum) frequentans, Penicillium pusillum, Penicillium turolense and Sclerotium sclerotiorum (Sclerotinia sclerotiorum). Before disinfection, Candida curvata and Candida albicans constituted the greatest proportion of the total fungi in the reservoirs water; in the water of handpieces--Candida albicans and Aspergillus glaucus group; and in the biofilm samples--Aspergillus glaucus group and Candida albicans. After disinfection, in all 3 kinds of samples, Candida albicans prevailed, constituting from 31.2-85.7 % of the total fungi. The application of agent containing hydrogen peroxide caused a significant decrease both in the number of total fungi and individual fungal species, which confirms the product effectiveness in fungal decontamination of DUWL.

  17. Thermodynamic properties of an emerging chemical disinfectant, peracetic acid.

    Science.gov (United States)

    Zhang, Chiqian; Brown, Pamela J B; Hu, Zhiqiang

    2018-04-15

    Peracetic acid (PAA or CH 3 COOOH) is an emerging disinfectant with a low potential to form carcinogenic disinfection by-products (DBPs). Basic thermodynamic properties of PAA are, however, absent or inconsistently reported in the literature. This review aimed to summarize important thermodynamic properties of PAA, including standard Gibbs energy of formation and oxidation-reduction (redox) potential. The standard Gibbs energies of formation of CH 3 COOOH (aq) , CH 3 COOOH (g) , CH 3 COOOH (l) , and CH 3 COOO (aq) - are -299.41kJ·mol -1 , -283.02kJ·mol -1 , -276.10kJ·mol -1 , and -252.60kJ·mol -1 , respectively. The standard redox potentials of PAA are 1.748V and 1.005V vs. standard hydrogen electrode (SHE) at pH 0 and pH 14, respectively. Under biochemical standard state conditions (pH 7, 25°C, 101,325Pa), PAA has a redox potential of 1.385V vs. SHE, higher than many disinfectants. Finally, the environmental implications of the thermodynamic properties of PAA were systematically discussed. Those properties can be used to predict the physicochemical and biological behavior of aquatic systems exposed to PAA. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Formation of trihalomethanes as disinfection byproducts in herbal spa pools.

    Science.gov (United States)

    Fakour, Hoda; Lo, Shang-Lien

    2018-04-09

    Herbal spa treatments are favorite recreational activities throughout the world. The water in spas is often disinfected to control pathogenic microorganisms and guarantee hygiene. However, chlorinated water may cause the formation of disinfection byproducts (DBPs). Although there have been many studies on DBP formation in swimming pools, the role of organic matter derived from herbal medicines applied in herbal spa water has been largely neglected. Accordingly, the present study investigated the effect of herbal medicines on the formation of trihalomethanes (THMs) in simulated herbal spa water. Water samples were collected from a spa pool, and then, disinfection and herbal addition experiments were performed in a laboratory. The results showed that the organic molecules introduced by the herbal medicines are significant precursors to the formation of THMs in spa pool water. Since at least 50% of THMs were produced within the first six hours of the reaction time, the presence of herbal medicines in spa water could present a parallel route for THM exposure. Therefore, despite the undeniable benefits of herbal spas, the effect of applied herbs on DBP formation in chlorinated water should be considered to improve the water quality and health benefits of spa facilities.

  19. Radiocarbon dating of iron artefacts

    Energy Technology Data Exchange (ETDEWEB)

    Cresswell, R. [Australian National Univ., Canberra, ACT (Australia). Dept. of Nuclear Physics

    1997-12-31

    Iron artefacts are generally dated by association or on stylistic grounds. This may not give a true indication of the date of manufacture, or may not be possible if the piece is out of context, ambiguous in style, or a copy. Obtaining a direct date on the artefact would be preferable. During the processes of manufacture, carbon is incorporated into the iron from the fuel source. If the fuel is of a material containing contemporaneous carbon, i.e. has an ambient radiocarbon signature, e.g. charcoal, then we may reliably radiocarbon date the artefact by extracting this carbon. Care must be taken, however, to ensure that re-working has not introduced multiple sources of carbon that would give an erroneous date. Detailed chemical analysis must precede radiocarbon analysis. Sample size is determined by carbon content, and before the advent of accelerator mass spectrometry, several tens of grams of carbon were required for radiocarbon dating (van der Merwe, 1969), prohibiting this method except for high-carbon cast-irons and bulk samples, e.g. caches of nails. AMS permits the analysis of sub-gram pieces of iron (Cresswell, 1991), thereby permitting the analysis of museum pieces with only minimal loss of material, and small fragments of iron recovered from archaeological sites. A few examples are given to illustrate these points. Paper no. 41; Extended abstract. 6 refs.

  20. Radiocarbon dating of iron artefacts

    International Nuclear Information System (INIS)

    Cresswell, R.

    1997-01-01

    Iron artefacts are generally dated by association or on stylistic grounds. This may not give a true indication of the date of manufacture, or may not be possible if the piece is out of context, ambiguous in style, or a copy. Obtaining a direct date on the artefact would be preferable. During the processes of manufacture, carbon is incorporated into the iron from the fuel source. If the fuel is of a material containing contemporaneous carbon, i.e. has an ambient radiocarbon signature, e.g. charcoal, then we may reliably radiocarbon date the artefact by extracting this carbon. Care must be taken, however, to ensure that re-working has not introduced multiple sources of carbon that would give an erroneous date. Detailed chemical analysis must precede radiocarbon analysis. Sample size is determined by carbon content, and before the advent of accelerator mass spectrometry, several tens of grams of carbon were required for radiocarbon dating (van der Merwe, 1969), prohibiting this method except for high-carbon cast-irons and bulk samples, e.g. caches of nails. AMS permits the analysis of sub-gram pieces of iron (Cresswell, 1991), thereby permitting the analysis of museum pieces with only minimal loss of material, and small fragments of iron recovered from archaeological sites. A few examples are given to illustrate these points