WorldWideScience

Sample records for tap water filters

  1. Tap water filters.

    Science.gov (United States)

    2003-02-01

    Moen PureTouch filters remove impurities from tap water without removing fluoride. These carbon block filters consist of finely powdered activated carbon that is combined with a plastic binder material and heated to form a hollow cylinder. The blocks are further wrapped with material to improve performance and reduce clogging. The filters are available with different filtering capabilities (Table 1). The filters mount in the faucet spout or under the sink.

  2. Impact of a silver layer on the membrane of tap water filters on the microbiological quality of filtered water.

    Science.gov (United States)

    Vonberg, Ralf-Peter; Sohr, Dorit; Bruderek, Juliane; Gastmeier, Petra

    2008-10-08

    Bacteria in the hospital's drinking water system represent a risk for the acquisition of a nosocomial infection in the severely immunocompromised host. Terminal tap water filters may be used to prevent nosocomial Legionnaires' disease. We present data from water samples using an improved kind of tap water filters. In a blinded study on an intermediate care unit of the thoracic surgery department, a modified type of the Germlyser water filter (Aqua-Free Membrane Technology) with a newly-introduced silver layer on the filtration membrane was compared to its preceding type without such a layer on 15 water outlets. We determined growth of Legionella, other pathogenic bacteria, and the total heterotrophic plate count in unfiltered water and filtered water samples after filter usage intervals of 1 through 4 weeks. A total of 299 water samples were tested. Twenty-nine of the 60 unfiltered water samples contained Legionella of various serogroups (baseline value). In contrast, all samples filtered by the original water filter and all but one of the water samples filtered by the modified filter type remained Legionella-free. No other pathogenic bacteria were detected in any filtered sample. The total plate count in water samples increased during use of both kinds of filters over time. However, for the first 7 days of use, there were significantly fewer water samples containing >100 CFU per mL when using the new filter device compared with the older filters or taps with no filter. No advantage was seen thereafter. The use of this type of terminal water filter is an appropriate method to protect immunocompromised patients from water-borne pathogens such as Legionella.

  3. Impact of a silver layer on the membrane of tap water filters on the microbiological quality of filtered water

    Directory of Open Access Journals (Sweden)

    Bruderek Juliane

    2008-10-01

    Full Text Available Abstract Background Bacteria in the hospital's drinking water system represent a risk for the acquisition of a nosocomial infection in the severely immunocompromised host. Terminal tap water filters may be used to prevent nosocomial Legionnaires' disease. We present data from water samples using an improved kind of tap water filters. Methods In a blinded study on an intermediate care unit of the thoracic surgery department, a modified type of the Germlyser water filter (Aqua-Free Membrane Technology with a newly-introduced silver layer on the filtration membrane was compared to its preceding type without such a layer on 15 water outlets. We determined growth of Legionella, other pathogenic bacteria, and the total heterotrophic plate count in unfiltered water and filtered water samples after filter usage intervals of 1 through 4 weeks. Results A total of 299 water samples were tested. Twenty-nine of the 60 unfiltered water samples contained Legionella of various serogroups (baseline value. In contrast, all samples filtered by the original water filter and all but one of the water samples filtered by the modified filter type remained Legionella-free. No other pathogenic bacteria were detected in any filtered sample. The total plate count in water samples increased during use of both kinds of filters over time. However, for the first 7 days of use, there were significantly fewer water samples containing >100 CFU per mL when using the new filter device compared with the older filters or taps with no filter. No advantage was seen thereafter. Conclusion The use of this type of terminal water filter is an appropriate method to protect immunocompromised patients from water-borne pathogens such as Legionella.

  4. Analysis of UV filters in tap water and other clean waters in Spain.

    Science.gov (United States)

    Díaz-Cruz, M Silvia; Gago-Ferrero, Pablo; Llorca, Marta; Barceló, Damià

    2012-03-01

    The present paper describes the development of a method for the simultaneous determination of five hormonally active UV filters namely benzophenone-3 (BP3), 3-(4-methylbenzylidene) camphor (4MBC), 2-ethylhexyl 4-(dimethylamino) benzoate (OD-PABA), 2-ethylhexyl 4-methoxycinnamate (EHMC) and octocrylene (OC) by means of solid-phase extraction and gas chromatography-electron impact ionization-mass spectrometry. Under optimized conditions, this methodology achieved low method limits of detection (needed for clean waters, especially drinking water analysis), between 0.02 and 8.42 ng/L, and quantitative recovery rates higher than 73% in all cases. Inter- and intraday precision for all compounds were lower than 7% and 11%, respectively. The optimized methodology was applied to perform the first survey of UV absorbing compounds in tap water from the metropolitan area and the city of Barcelona (Catalonia, Spain). In addition, other types of clean water matrices (mineral bottled water, well water and tap water treated with an ion-exchange resin) were investigated as well. Results evidenced that all the UV filters investigated were detected in the water samples analyzed. The compounds most frequently found were EHMC and OC. Maximum concentrations reached in tap water were 290 (BP3), 35 (4MBC), 110 (OD-PABA), 260 (EHMC), and 170 ng/L (OC). This study constitutes the first evidence of the presence of UV filter residues in tap water in Europe.

  5. Bottled, filtered, and tap water use in Latino and non-Latino children.

    Science.gov (United States)

    Hobson, Wendy L; Knochel, Miguel L; Byington, Carrie L; Young, Paul C; Hoff, Charles J; Buchi, Karen F

    2007-05-01

    To describe bottled, filtered, and tap water consumption and fluoride use among pediatric patients; to analyze differences between ethnic and socioeconomic groups; and to describe the frequency of physician-parent discussions regarding water consumption. Convenience sample survey. An urban public health clinic. Parents attending a public health clinic. The primary outcome measure was the prevalence of tap, filtered, and bottled water use. The secondary outcome measures were supplemental fluoride use and the percentage of patients reporting discussions of water consumption with their physician. A total of 216 parents (80.5% Latino and 19.5% non-Latino) completed the survey. Of the parents, 30.1% never drank tap water and 41.2% never gave it to their children. Latino parents were less likely than non-Latino parents to drink tap water (odds ratio, 0.26; 95% confidence interval, 0.10-0.67) and less likely to give tap water to their children (odds ratio, 0.32; 95% confidence interval, 0.15-0.70). More Latinos believed that tap water would make them sick (odds ratio, 5.63; 95% confidence interval, 2.17-14.54). Approximately 40% of children who never drank tap water were not receiving fluoride supplements. Of the lowest-income families (water to their children. Of the parents surveyed, 82.5% reported that their child's physician had never discussed the type of water they should use. Many Latino families avoid drinking tap water because they fear it causes illness. Unnecessary use of bottled and filtered water is costly and may result in adverse dental health outcomes. Physicians should provide guidance to families regarding the safety, low cost, and dental health benefits of drinking tap water.

  6. Neither hollow-fibre membrane filters nor activated-charcoal filters remove fluoride from fluoridated tap water.

    Science.gov (United States)

    Konno, Hideki; Yaegaki, Ken; Tanaka, Tomoko; Sato, Tsutomu; Itai, Kazuyoshi; Imai, Toshio; Murata, Takatoshi; Herai, Mayumi

    2008-06-01

    Previous reports of the reduction of fluoride concentrations in fluoridated water by domestic water treatment systems have indicated that further supplementation with fluoride is required. However, the absorption of fluoride by filters has not yet been directly identified. If these filters do not absorb fluoride, further fluoride supplementation may increase fluorosis. In this study, we determined whether filtering systems absorb fluoride ions. We directly measured the amounts of fluoride absorbed by activated-carbon filters or hollow-fibre membrane filters using pyrohydrolysis of the filters and flow-injection analysis, the sensitivity of which is more than 100 times greater than that of conventional methods. We made fluoride solutions of pure or tap water and determined changes in fluoride concentration as a result of filtering with a fluoride electrode. Hollow-fibre membrane filters did not affect fluoride concentrations in the fluoridated water, but activated-carbon filters removed some fluoride, especially from the pure-water solution. Filtering a pure-water solution with a fluoride concentration of 0.8 mg F/L reduced the fluoride concentration until 210 L of the solution had been filtered. However, filtering a tap-water solution of 0.8 mg F/L reduced the fluoride concentration only until 8 L had been filtered. The concentration of absorbed fluoride in the filter at 10 L of filtration was 4.7 mg/kg activated carbon. Further fluoride supplementation of fluoridated water should not be necessary, regardless of whether an activated-carbon or hollow-fibre membrane filter is installed on a domestic water treatment system.

  7. The Effect of Different Boiling and Filtering Devices on the Concentration of Disinfection By-Products in Tap Water

    Directory of Open Access Journals (Sweden)

    Glòria Carrasco-Turigas

    2013-01-01

    Full Text Available Disinfection by-products (DBPs are ubiquitous contaminants in tap drinking water with the potential to produce adverse health effects. Filtering and boiling tap water can lead to changes in the DBP concentrations and modify the exposure through ingestion. Changes in the concentration of 4 individual trihalomethanes (THM4 (chloroform (TCM, bromodichloromethane (BDCM, dibromochloromethane (DBCM, and bromoform (TBM, MX, and bromate were tested when boiling and filtering high bromine-containing tap water from Barcelona. For filtering, we used a pitcher-type filter and a household reverse osmosis filter; for boiling, an electric kettle, a saucepan, and a microwave were used. Samples were taken before and after each treatment to determine the change in the DBP concentration. pH, conductivity, and free/total chlorine were also measured. A large decrease of THM4 (from 48% to 97% and MX concentrations was observed for all experiments. Bromine-containing trihalomethanes were mostly eliminated when filtering while chloroform when boiling. There was a large decrease in the concentration of bromate with reverse osmosis, but there was a little effect in the other experiments. These findings suggest that the exposure to THM4 and MX through ingestion is reduced when using these household appliances, while the decrease of bromate is device dependent. This needs to be considered in the exposure assessment of the epidemiological studies.

  8. The Effect of Different Boiling and Filtering Devices on the Concentration of Disinfection By-Products in Tap Water

    Science.gov (United States)

    Carrasco-Turigas, Glòria; Villanueva, Cristina M.; Goñi, Fernando; Rantakokko, Panu; Nieuwenhuijsen, Mark J.

    2013-01-01

    Disinfection by-products (DBPs) are ubiquitous contaminants in tap drinking water with the potential to produce adverse health effects. Filtering and boiling tap water can lead to changes in the DBP concentrations and modify the exposure through ingestion. Changes in the concentration of 4 individual trihalomethanes (THM4) (chloroform (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM), and bromoform (TBM)), MX, and bromate were tested when boiling and filtering high bromine-containing tap water from Barcelona. For filtering, we used a pitcher-type filter and a household reverse osmosis filter; for boiling, an electric kettle, a saucepan, and a microwave were used. Samples were taken before and after each treatment to determine the change in the DBP concentration. pH, conductivity, and free/total chlorine were also measured. A large decrease of THM4 (from 48% to 97%) and MX concentrations was observed for all experiments. Bromine-containing trihalomethanes were mostly eliminated when filtering while chloroform when boiling. There was a large decrease in the concentration of bromate with reverse osmosis, but there was a little effect in the other experiments. These findings suggest that the exposure to THM4 and MX through ingestion is reduced when using these household appliances, while the decrease of bromate is device dependent. This needs to be considered in the exposure assessment of the epidemiological studies. PMID:23476675

  9. Nickel in tap water

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Nielsen, G D; Flyvholm, Morten

    1983-01-01

    Nickel analyses of tap water from several sources in Copenhagen gave up to 490 X 10(-6) g X 1(-1) in the first 250 ml portions. Hot water gave higher values than cold water. After flushing for 5 min, low values were found. Considerable variation from time to time and from tap to tap was found...

  10. Relay self interference minimisation using tapped filter

    KAUST Repository

    Jazzar, Saleh

    2013-05-01

    In this paper we introduce a self interference (SI) estimation and minimisation technique for amplify and forward relays. Relays are used to help forward signals between a transmitter and a receiver. This helps increase the signal coverage and reduce the required transmitted signal power. One problem that faces relays communications is the leaked signal from the relay\\'s output to its input. This will cause an SI problem where the new received signal at the relay\\'s input will be added with the unwanted leaked signal from the relay\\'s output. A Solution is proposed in this paper to estimate and minimise this SI which is based upon using a tapped filter at the destination. To get the optimum weights for this tapped filter, some channel parameters must be estimated first. This is performed blindly at the destination without the need of any training. This channel parameter estimation method is named the blind-self-interference-channel-estimation (BSICE) method. The next step in the proposed solution is to estimate the tapped filter\\'s weights. This is performed by minimising the mean squared error (MSE) at the destination. This proposed method is named the MSE-Optimum Weight (MSE-OW) method. Simulation results are provided in this paper to verify the performance of BSICE and MSE-OW methods. © 2013 IEEE.

  11. Analysis of tap weight errors in CCD transversal filters

    NARCIS (Netherlands)

    Ricco, Bruno; Wallinga, Hans

    1978-01-01

    A method is presented to determine and evaluate the actual tap weight errors in CCD split-electrode transversal filters. It is concluded that the correlated part in the tap weight errors dominates the random errors.

  12. Radioactive substances in tap water.

    Science.gov (United States)

    Atsuumi, Ryo; Endo, Yoshihiko; Suzuki, Akihiko; Kannotou, Yasumitu; Nakada, Masahiro; Yabuuchi, Reiko

    2014-01-01

    A 9.0 magnitude (M) earthquake with an epicenter off the Sanriku coast occurred at 14: 46 on March 11, 2011. TEPCO Fukushima Daiichi Nuclear Power Plant (F-1 NPP) was struck by the earthquake and its resulting tsunami. Consequently a critical nuclear disaster developed, as a large quantity of radioactive materials was released due to a hydrogen blast. On March 16(th), 2011, radioiodine and radioactive cesium were detected at levels of 177 Bq/kg and 58 Bq/kg, respectively, in tap water in Fukushima city (about 62km northwest of TEPCO F-1 NPP). On March 20th, radioiodine was detected in tap water at a level of 965 Bq/kg, which is over the value-index of restrictions on food and drink intake (radioiodine 300 Bq/kg (infant intake 100 Bq/kg)) designated by the Nuclear Safety Commission. Therefore, intake restriction measures were taken regarding drinking water. After that, although the all intake restrictions were lifted, in order to confirm the safety of tap water, an inspection system was established to monitor all tap water in the prefecture. This system has confirmed that there has been no detection of radioiodine or radioactive cesium in tap water in the prefecture since May 5(th), 2011. Furthermore, radioactive strontium ((89) Sr, (90)Sr) and plutonium ((238)Pu, (239)Pu+(240)Pu) in tap water and the raw water supply were measured. As a result, (89) Sr, (238)Pu, (239)Pu+(240)Pu were undetectable and although (90)Sr was detected, its committed effective dose of 0.00017 mSv was much lower than the yearly 0.1 mSv of the World Health Organization guidelines for drinking water quality. In addition, the results did not show any deviations from past inspection results.

  13. Lead and tap water

    Science.gov (United States)

    Water contaminated with lead ... The Environmental Protection Agency (EPA) monitors drinking water in the United States. It requires water suppliers to produce annual water quality reports. These reports include information about lead amounts, and they ...

  14. Contamination Control and Monitoring of Tap Water as Fluid in Industrial Tap Water Hydraulic Systems

    DEFF Research Database (Denmark)

    Conrad, Finn; Adelstorp, Anders

    1998-01-01

    Presentation of results and methods addressed to contamination control and monitoring of tap water as fluid in tap water hydraulic systems.......Presentation of results and methods addressed to contamination control and monitoring of tap water as fluid in tap water hydraulic systems....

  15. BACTERIOLOGICAL QUALITY OF TAP WATER

    Directory of Open Access Journals (Sweden)

    Justyna Zamorska

    2016-06-01

    Full Text Available The most sensitive method of detecting contamination in water supply networks is microbiological testing. Microbiological water safety is evaluated mainly based on the results of traditional tests that rely on bacteria culturing on the so called bacterial growth mediums. Flow cytometry is a modern technology that has been used in microbiology only recently. The diagnostic method based on flow cytometry is much faster and more versatile. Microbiological quality testing was conducted in rzeszowski district, in the area of water network supplied by surface waters, and in the area of water network supplied by underground waters. The scope of the analysis of the microbiological quality of tap water was based on the determination of selected indicators of the sanitary condition of water ie; the total number of psychrophilic and mesophilic bacteria on nutrient agar (reference called Agar A and additionally called agar supplemented with R, the number of coliforms and faecal streptococci. Determination of the total number of microorganisms by flow cytometry was performed using two dyes SYBR Green and iodide pyridine. Water from underground water intakes, not under the permanent control of microbial had worse microbiological parameters. Used new methods of microbiological assays showed greater amounts of microbiological contamination.

  16. Evaluation on the Quality of Bangkok Tap Water with Other Drinking Purpose Water

    Science.gov (United States)

    Kordach, A.; Chardwattananon, C.; Wongin, K.; Chayaput, B.; Wongpat, N.

    2018-02-01

    The concern of drinking purposed water quality in Bangkok, Nonthaburi, and Samutprakarn provinces has been a problem for over fifteen years. Metropolitan Water Works Authority (MWA) of Thailand is fully responsible for providing water supply to the mentioned areas. The objective of Drinkable Tap Water Project is to make people realize in quality of tap water. Communities, school, government agencies, hotels, hospitals, department stores, and other organizations are participating in this project. MWA have collected at least 3 samples of water from the corresponding places and the samples have to meet the World Health Organization (WHO) guidelines level. This study is to evaluate water quality of tap water, storage water, filtered water, and filtered water dispenser. The water samples from 2,354 attending places are collected and analyzed. From October 2011 to September 2016, MWA analyzed 32,711 samples. The analyzed water parameters are free residual chlorine, appearance color, turbidity, pH, conductivity, total dissolved solids (TDS), and pathogenic bacteria; E.coli. The results indicated that a number of tap water samples had the highest number compliance with WHO guidelines levels at 98.40%. The filtered water, filtered water dispenser, and storage water were received 96.71%, 95.63%, and 90.88%, respectively. However, the several samples fail to pass WHO guideline level because they were contaminated by E.coli. The result is that tap water has the highest score among other sources probably because tap water has chlorine for disinfection and always is monitored by professional team round-the-clock services compared to the other water sources with less maintenance or cleaning. Also, water quality reports are continuously sent to customers by mail addresses. Tap water quality data are shown on MWA websites and Facebook. All these steps of work should enhance the confidence of tap water quality.

  17. Evaluation on the Quality of Bangkok Tap Water with Other Drinking Purpose Water

    Directory of Open Access Journals (Sweden)

    Kordach A.

    2018-01-01

    Full Text Available The concern of drinking purposed water quality in Bangkok, Nonthaburi, and Samutprakarn provinces has been a problem for over fifteen years. Metropolitan Water Works Authority (MWA of Thailand is fully responsible for providing water supply to the mentioned areas. The objective of Drinkable Tap Water Project is to make people realize in quality of tap water. Communities, school, government agencies, hotels, hospitals, department stores, and other organizations are participating in this project. MWA have collected at least 3 samples of water from the corresponding places and the samples have to meet the World Health Organization (WHO guidelines level. This study is to evaluate water quality of tap water, storage water, filtered water, and filtered water dispenser. The water samples from 2,354 attending places are collected and analyzed. From October 2011 to September 2016, MWA analyzed 32,711 samples. The analyzed water parameters are free residual chlorine, appearance color, turbidity, pH, conductivity, total dissolved solids (TDS, and pathogenic bacteria; E.coli. The results indicated that a number of tap water samples had the highest number compliance with WHO guidelines levels at 98.40%. The filtered water, filtered water dispenser, and storage water were received 96.71%, 95.63%, and 90.88%, respectively. However, the several samples fail to pass WHO guideline level because they were contaminated by E.coli. The result is that tap water has the highest score among other sources probably because tap water has chlorine for disinfection and always is monitored by professional team round-the-clock services compared to the other water sources with less maintenance or cleaning. Also, water quality reports are continuously sent to customers by mail addresses. Tap water quality data are shown on MWA websites and Facebook. All these steps of work should enhance the confidence of tap water quality.

  18. Sinusitis from Nontuberculous Mycobacteria in Tap Water

    Centers for Disease Control (CDC) Podcasts

    2012-12-21

    Dr. Wellington S. Tichenor. Associate Clinical Professor of Medicine at New York Medical College and in private practice in Manhattan, New York, discusses his investigation of sinusitis from nontuberculous mycobacteria in tap water.  Created: 12/21/2012 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 12/31/2012.

  19. Bottled Water or Tap Water? A Comparative Study of Drinking Water Choices on University Campuses

    Directory of Open Access Journals (Sweden)

    Neng Qian

    2018-01-01

    Full Text Available A cross-regional comparative study was conducted to survey the drinking behaviors of university students, in Singapore, Hong Kong, and Macau. In particular, I tested students’ preference for bottled water over filtered tap water, in a context where the latter option is widely accessible, free of charge, and meets drinking standards. It was found that Singapore has a relatively low rate of bottled water consumption within the young population of university students, while in Hong Kong and Macau one-fourth of the students still drink bottled water more frequently than tap water. Using the Theory of Planned Behavior framework, the perceptions and factors that determine the choices were studied. In terms of determinants of the drinking water choices, “Safety and Hygiene” and “Convenience and Availability” ranked highest for all three regions. “Taste”, “Price”, and “Personal and Family Habits” were valued next by different subsamples. Respondents from Singapore rated relatively high in the accessibility of filtered tap water, safety of tap water transfer, and trust in government, and these factors are considerably significant in driving the result of having the lowest consumption of bottle water on campus. Gender and the behaviors of students who stay in campus dorms were also explored.

  20. What's Wrong with the Tap? Examining Perceptions of Tap Water and Bottled Water at Purdue University

    Science.gov (United States)

    Saylor, Amber; Prokopy, Linda Stalker; Amberg, Shannon

    2011-09-01

    The environmental impacts of bottled water prompted us to explore drinking water choices at Purdue University, located in West Lafayette, IN. A random sample of 2,045 Purdue University students, staff, and faculty was invited to participate in an online survey. The survey assessed current behaviors as well as perceived barriers and benefits to drinking tap water versus bottled water. 677 surveys were completed for a response rate of 33.1%. We then conducted qualitative interviews with a purposive sample of university undergraduates ( n = 21) to obtain contextual insights into the survey results and the beliefs of individuals with a variety of drinking water preferences. This study revealed that women drink disproportionately more bottled water then men while undergraduate students drink more than graduate students, staff and faculty. The study also uncovered a widespread belief that recycling eliminates the environmental impacts of bottled water. Important barriers to drinking tap water at Purdue include: perceived risks from tap water and the perceived safety of bottled water, preferring the taste of bottled water, and the convenience of drinking bottled water. The qualitative interviews revealed that drinking water choices can be influenced by several factors—especially whether individuals trust tap water to be clean—but involve varying levels of complexity. The implications of these results for social marketing strategies to promote tap water are discussed.

  1. BACTERIOLOGICAL QUALITY OF TAP WATER

    OpenAIRE

    Justyna Zamorska; Monika Zdeb; Dorota Papciak

    2016-01-01

    The most sensitive method of detecting contamination in water supply networks is microbiological testing. Microbiological water safety is evaluated mainly based on the results of traditional tests that rely on bacteria culturing on the so called bacterial growth mediums. Flow cytometry is a modern technology that has been used in microbiology only recently. The diagnostic method based on flow cytometry is much faster and more versatile. Microbiological quality testing was conducted in rzes...

  2. Chapter 13. Industrial Application of Tap Water Hydraulic Systems

    DEFF Research Database (Denmark)

    Conrad, Finn; Adelstorp, Anders

    1997-01-01

    Design and application of modern pure tap water components and systems in industries, in particular food processing industry.......Design and application of modern pure tap water components and systems in industries, in particular food processing industry....

  3. Chapter 12. Pure Tap Water Hydraulic Systems and Applications

    DEFF Research Database (Denmark)

    Conrad, Finn; Adelstorp, Anders

    1997-01-01

    Presentation of developed a modern pure tap water hydraulic components (Nessie), systems and industrial applications.......Presentation of developed a modern pure tap water hydraulic components (Nessie), systems and industrial applications....

  4. Multiplication of Legionella pneumophila in unsterilized tap water.

    OpenAIRE

    Yee, R B; Wadowsky, R M

    1982-01-01

    Naturally occurring Legionella pneumophila, an environmental isolate which had not been grown on artificial medium, was tested for the ability to multiply in tap water. A showerhead containing L. pneumophila and non-Legionellaceae bacteria was immersed in nonsterile tap water supplying this fixture. Also L. pneumophila and non-Legionellaceae bacteria were sedimented from tap water from a surgical intensive care unit. This bacterial suspension was inoculated into tap water from our laboratory....

  5. Drinking of tap water is smart, but how do it better? - A tap water quality research

    Science.gov (United States)

    Mika, Anna; Sekuła, Klaudia; Dendys, Marta; Ptaszek, Weronika; Postawa, Adam

    2018-02-01

    Drinking tap water has recently become popular. It is a way to fight with the tons of garbage (disposable, plastic bottles). However, many people are afraid of water quality. The research was performed in December 2015 in Krakow, during one week. 56 samples were collected. The samples were taken in different times of the day and in the two types of building (old one with installation from the 80s and new one with installation built in past few years). Samples were taken by two qualified operators. The first sample was collected at the morning at 6 a.m., before anyone uses the tap. The second one after the tap was flushed and then the third one after 30 minutes stagnation. At the evening was taken one sample (after using the tap all day).The aim of the research was to check the quality of drinking water in the end-user. The results show that quality of tap water in Krakow is good, also in the end-user, but the concentration of chemical elements are changing during the flushing and using of the tap.

  6. Radiostrontium in milk and tap water

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    The New York City sample is a monthly composite of pasteurized milk purchased daily at retail stores. During appropriate periods Sr-89, as well as Sr-90, has been analyzed in these milk samples. The monthly Sr-90 to calcium ratios for New York City since the inception of the sampling program are presented in the table on page C-3. These data are presented graphically in the figure on page C-4. Samples of New York City tap water are taken daily at EML so that by the end of the month, approximately 100 liters have been collected. The Sr-90 data since the inception of the program are presented in the table on page C-5. The available cesium-137 data expressed as the Cs-137 to Sr-90 ratio are given in the table on page C-6. A graphical presentation of the New York City Sr-90 data is shown in the figure on page C-7

  7. Performance evaluation of conventional and water saving taps.

    Science.gov (United States)

    Fidar, A M; Memon, F A; Butler, D

    2016-01-15

    The rapid pace of urbanisation comes with considerable environmental implications including pressures on already stressed limited water resources. In urban areas, most of the water use is associated with water consumption in buildings. The second largest use of water is via taps. It is often assumed that water taps with low flow rates can contribute to reduced per capita water consumption. However, this is based on very little evidence. This paper presents the synthesis of a 13,000 high resolution observations made to investigate the actual water consumption of innovative (water saving) electronic taps and conventional mixer taps. High resolution flow-meters and data loggers were fitted into two washrooms in two different buildings of a higher education institution to record the water use through the basin taps. The recorded data provided information on duration, frequency of use and volume of water consumption per use. The data was helpful in identifying trends in hot and cold water use and therefore can be useful in estimating energy for producing hot water and associated greenhouse gas emissions. Analysis of the observed data suggests that the low flow taps have greater mean water consumption per event than the conventional taps and water consumption is more influenced by user behaviour rather than the technology. Copyright © 2015. Published by Elsevier B.V.

  8. Water use and time analysis in ablution from taps

    Science.gov (United States)

    Zaied, Roubi A.

    2017-09-01

    There is a lack of water resources and an extreme use of potable water in our Arab region. Ablution from taps was studied since it is a repeated daily activity that consumes more water. Five different tap types are investigated for water consumption fashions including traditional mixing tap and automatic tap. Analyzing 100 experimental observations revealed that 22.7-28.8 % of ablution water is used for washing of feet and the largest water waste occurs during washing of face portions. Moreover, 30-47 % amount of water consumed in ablution from taps is wasted which can be saved if tap releases water only at moments of need. The push-type tap is being spread recently especially in airports. If it is intended for use in ablution facilities, batch duration and volume must be tuned. When each batch is 0.25 L of water and lasts for 3 s, 3 L are sufficient for one complete ablution in average which means considerable saving. A cost-benefit model is proposed for using different tap types and an economic feasibility study is performed on a case study. This analysis can help us to design better ablution systems.

  9. Hydraulic Systems with Tap Water versus Bio-oils

    DEFF Research Database (Denmark)

    Conrad, Finn

    1997-01-01

    Deals with the advantages of using pure tap water hydraulics versus bio-oils for suiteable applications. Focus is in particular on food processing industry.......Deals with the advantages of using pure tap water hydraulics versus bio-oils for suiteable applications. Focus is in particular on food processing industry....

  10. Tap Water Hydraulic Systems for Medium Power Applications

    DEFF Research Database (Denmark)

    Conrad, Finn; Adelstorp, Anders

    1998-01-01

    Presentation of new range of developed tap water hydraulic componets and applications for medium power up to 4 kW and 50 bar.......Presentation of new range of developed tap water hydraulic componets and applications for medium power up to 4 kW and 50 bar....

  11. Tap-length optimization of adaptive filters used in stereophonic acoustic echo cancellation

    DEFF Research Database (Denmark)

    Kar, Asutosh; Swamy, M.N.S.

    2017-01-01

    An adaptive filter with a large number of weights or taps is necessary for stereophonic acoustic echo cancellation (SAEC), depending on the room impulse response and acoustic path where the cancellation is performed. However, a large tap-length results in slow convergence and increases...... is applied to an existing multiple sub-filter-based echo canceller, for which we present a convergence analysis. Computer simulations are also presented, comparing the proposed approach with related work....... of acoustic echo paths. The tap-length optimization is applied to a single long adaptive filter with thousands of coefficients to decrease the total number of weights, which in turn reduces the computational load. To further increase the convergence rate, the proposed tap-length-optimization algorithm...

  12. The Danger of Using Tap Water with Contact Lenses

    Science.gov (United States)

    Acanthamoeba is a microbe that is very common in tap water. It has two forms: the trophozoite and the cyst. These trophozoites and cysts can stick to the surface of your contact lenses and then infect your eye.

  13. Multiplication of Legionella pneumophila in unsterilized tap water.

    Science.gov (United States)

    Yee, R B; Wadowsky, R M

    1982-06-01

    Naturally occurring Legionella pneumophila, an environmental isolate which had not been grown on artificial medium, was tested for the ability to multiply in tap water. A showerhead containing L. pneumophila and non-Legionellaceae bacteria was immersed in nonsterile tap water supplying this fixture. Also L. pneumophila and non-Legionellaceae bacteria were sedimented from tap water from a surgical intensive care unit. This bacterial suspension was inoculated into tap water from our laboratory. The legionellae in both suspensions multiplied in the tap water at 32, 37, and 42 degrees C. The non-Legionellaceae bacteria multiplied at 25, 32, and 37 degrees C. A water sample which was collected from the bottom of a hot water tank was found to contain L. pneumophila and non-Legionellaceae bacteria. These legionellae also multiplied when the water sample was incubated at 37 degrees C. These results indicate that L. pneumophila may multiply in warm water environments such as hot water plumbing fixtures, hot water tanks, and cooling towers.

  14. Divergence of stable isotopes in tap water across China

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Sihan; Hu, Hongchang; Tian, Fuqiang; Tie, Qiang; Wang, Lixin; Liu, Yaling; Shi, Chunxiang

    2017-03-02

    Stable isotopes in water (e.g., δ2H and δ18O) are important indicators of hydrological and ecological patterns and processes. Tap water can reflect integrated features of regional hydrological processes and human activities. China is a large country with significant meteorological and geographical variations. This report presents the first national-scale survey of Stable Isotopes in Tap Water (SITW) across China. 780 tap water samples have been collected from 95 cities across China from December 2014 to December 2015. (1) Results yielded the Tap Water Line in China is δ2H = 7.72 δ18O + 6.57 (r2 = 0.95). (2) SITW spatial distribution presents typical "continental effect". (3) SITW seasonal variations indicate clearly regional patterns but no trends at the national level. (4) SITW can be correlated in some parts with geographic or meteorological factors. This work presents the first SITW map in China, which sets up a benchmark for further stable isotopes research across China. This is a critical step toward monitoring and investigating water resources in climate-sensitive regions, so the human-hydrological system. These findings could be used in the future to establish water management strategies at a national or regional scale. Title: Divergence of stable isotopes in tap water across China Authors: Zhao, SH; Hu, HC; Tian, FQ; Tie, Q; Wang, LX; Liu, YL; Shi, CX Source: SCIENTIFIC REPORTS, 7 10.1038/srep43653 MAR 2 2017

  15. Tunable and reconfigurable multi-tap microwave photonic filter based on dynamic Brillouin gratings in fibers.

    Science.gov (United States)

    Sancho, J; Primerov, N; Chin, S; Antman, Y; Zadok, A; Sales, S; Thévenaz, L

    2012-03-12

    We propose and experimentally demonstrate new architectures to realize multi-tap microwave photonic filters, based on the generation of a single or multiple dynamic Brillouin gratings in polarization maintaining fibers. The spectral range and selectivity of the proposed periodic filters is extensively tunable, simply by reconfiguring the positions and the number of dynamic gratings along the fiber respectively. In this paper, we present a complete analysis of three different configurations comprising a microwave photonic filter implementation: a simple notch-type Mach-Zehnder approach with a single movable dynamic grating, a multi-tap performance based on multiple dynamic gratings and finally a stationary grating configuration based on the phase modulation of two counter-propagating optical waves by a common pseudo-random bit sequence (PRBS).

  16. Phthalate occurrence in rivers and tap water from central Spain.

    Science.gov (United States)

    Domínguez-Morueco, N; González-Alonso, S; Valcárcel, Y

    2014-12-01

    The aim of this study is to evaluate the presence and concentrations of the main phthalates in water from the Jarama and Manzanares rivers in the region of Madrid (RM, Central Spain), the most densely populated region of Spain, and to determine the possible oestrogenic activity based on found phthalate concentration. The presence of phthalates in major supply drinking water areas of the RM was also analysed, thus allowing a preliminary assessment of the health risks resulting from the concentrations obtained. The results of this study show the presence of the three (dimethyl phthalate (DMP), diethyl phthalate (DEP) di-n-butyl phthalate (DBP)) of five phthalates studied (dimethyl phthalate (DMP), diethyl phthalate (DEP), di-(2-ethylhexyl) phthalate (DEHP), benzyl-butyl phthalate (BBP) and di-n-butyl phthalate (DBP)). The DBP was found in both river and tap water samplers, whereas DMP and DEP were found in only drinking water samples. The DBP was found to make the highest average contribution to pollution in both river and tap water. The DEHP was not found in both the river and tap water because it is one of the most regulated phthalates. The highest phthalate contamination was found in the Manzanares river and in those areas that receive treated water from the Tagus river. The phthalates found in river and tap water in the RM do not represent a potential oestrogenic risk for the aquatic environment or humans. A preliminary risk assessment suggested that the risk of exposure to phthalates from tap water in this study is acceptable, although continuous monitoring of the presence of these substances in both drinking and river water should be undertaken to detect possible increases in their concentrations. This is the first study to analyse the presence of phthalates in both rivers and drinking water of the centre of Spain. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Microbial Bioload of Some Tap Water Samples from Enugu, Enugu ...

    African Journals Online (AJOL)

    Bacteriological screening on all sample groups indicated the presence of microorganism in tap water available in all eleven locations. Further characterization using biochemical methods revealed the absence of E. coli, and the presence of Pseudomonas aeruginosa. Shigella species and Salmonella species in sample ...

  18. Multiplication of Legionella spp. in tap water containing Hartmannella vermiformis.

    Science.gov (United States)

    Wadowsky, R M; Wilson, T M; Kapp, N J; West, A J; Kuchta, J M; States, S J; Dowling, J N; Yee, R B

    1991-07-01

    A model was developed to study the multiplication of various Legionella spp. in tap water containing Hartmannella vermiformis. Tap water cultures prepared with the following components were suitable for the multiplication studies: Legionella spp., 10(3) CFU/ml; H. vermiformis, 10(4.4) cysts per ml; and killed Pseudomonas paucimobilis, 10(9) cells per ml. Cocultures were incubated at 37 degrees C for at least 1 week. The following legionellae multiplied in tap water cocultures in each replicate experiment: L. bozemanii (WIGA strain), L. dumoffii (NY-23 and TX-KL strains), L. micdadei (two environmental strains), and L. pneumophila (six environmental strains and one clinical isolate). Growth yield values for these strains were 0.6 to 3.5 log CFU/ml. Legionellae which did not multiply in replicate cocultures included L. anisa (one strain), L. bozemanii (MI-15 strain), L. micdadei (a clinical isolate), L. longbeachae, (one strain), and L. pneumophila (Philadelphia 1 strain). L. gormanii and an environmental isolate of L. pneumophila multiplied in only one of three experiments. None of the legionellae multiplied in tap water containing only killed P. paucimobilis. The mean growth yield (+/- standard deviation) of H. vermiformis in the cocultures was 1.2 +/- 0.1 log units/ml. H. vermiformis supports multiplication of only particular strains of legionellae, some of which are from diverse origins.

  19. [Nitrate concentrations in tap water in Spain].

    Science.gov (United States)

    Vitoria, Isidro; Maraver, Francisco; Sánchez-Valverde, Félix; Armijo, Francisco

    2015-01-01

    To determine nitrate concentrations in drinking water in a sample of Spanish cities. We used ion chromatography to analyze the nitrate concentrations of public drinking water in 108 Spanish municipalities with more than 50,000 inhabitants (supplying 21,290,707 potential individuals). The samples were collected between January and April 2012. The total number of samples tested was 324. The median nitrate concentration was 3.47 mg/L (range: 0.38-66.76; interquartile range: 4.51). The water from 94% of the municipalities contained less than 15 mg/L. The concentration was higher than 25mg/L in only 3 municipalities and was greater than 50mg/L in one. Nitrate levels in most public drinking water supplies in municipalities inhabited by almost half of the Spanish population are below 15 mg/L. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

  20. Microbiological tap water profile of a medium-sized building and effect of water stagnation.

    Science.gov (United States)

    Lipphaus, Patrick; Hammes, Frederik; Kötzsch, Stefan; Green, James; Gillespie, Simon; Nocker, Andreas

    2014-01-01

    Whereas microbiological quality of drinking water in water distribution systems is routinely monitored for reasons of legal compliance, microbial numbers in tap water are grossly understudied. Motivated by gross differences in water from private households, we applied in this study flow cytometry as a rapid analytical method to quantify microbial concentrations in water sampled at diverse taps in a medium size research building receiving chlorinated water. Taps differed considerably in frequency of usage and were located in laboratories, bathrooms, and a coffee kitchen. Substantial differences were observed between taps with concentrations (per mL) in the range from 6.29 x 10(3) to 7.74 x 10(5) for total cells and from 1.66 x 10(3) to 4.31 x 10(5) for intact cells. The percentage of intact cells varied between 7% and 96%. Water from taps with very infrequent use showed the highest bacterial numbers and the highest proportions of intact cells. Stagnation tended to increase microbial numbers in water from those taps which were otherwise frequently used. Microbial numbers in other taps that were rarely opened were not affected by stagnation as their water is probably mostly stagnant. For cold water taps, microbial numbers and the percentage of intact cells tended to decline with flushing with the greatest decline for taps used least frequently whereas microbial concentrations in water from hot water taps tended to be somewhat more stable. We conclude that microbiological water quality is mainly determined by building-specific parameters. Tap water profiling can provide valuable insight into plumbing system hygiene and maintenance.

  1. 40 CFR 141.86 - Monitoring requirements for lead and copper in tap water.

    Science.gov (United States)

    2010-07-01

    ... copper in tap water. 141.86 Section 141.86 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 141.86 Monitoring requirements for lead and copper in tap water. (a) Sample site location. (1) By the... the water system can collect the number of lead and copper tap samples required in paragraph (c) of...

  2. Optimization of Adenovirus 40 and 41 Recovery from Tap Water

    Science.gov (United States)

    Currently, the U.S. Environmental Protection Agency’s Information Collection Rule (ICR) for the primary concentration of viruses from drinking and surface waters uses the 1MDS filter; however, a more cost effective option, the NanoCeram® filter, has been shown to recover comparab...

  3. Perceptions of Tap Water and School Water Fountains and Association with Intake of Plain Water and Sugar-Sweetened Beverages

    Science.gov (United States)

    Onufrak, Stephen J.; Park, Sohyun; Sharkey, Joseph R.; Merlo, Caitlin; Dean, Wesley R.; Sherry, Bettylou

    2014-01-01

    Background: Little is known regarding youth perceptions of tap water and school water fountains and how these relate to water and sugar-sweetened beverage (SSB) intake. Methods: We used national 2010 YouthStyles data to assess perceptions of tap water and school water fountains and associations with water and SSB intake. Results: Nearly 1 in 5…

  4. Isolation and Identification of Free-Living Amoebae from Tap Water in Sivas, Turkey

    Directory of Open Access Journals (Sweden)

    Kübra Açıkalın Coşkun

    2013-01-01

    Full Text Available The present work focuses on a local survey of free-living amoebae (FLA that cause opportunistic and nonopportunistic infections in humans. Determining the prevalence of FLA in water sources can shine a light on the need to prevent FLA related illnesses. A total of 150 samples of tap water were collected from six districts of Sivas province. The samples were filtered and seeded on nonnutrient agar containing Escherichia coli spread. Thirty-three (22% out of 150 samples were found to be positive for FLA. The FLA were identified by morphology and by PCR using 18S rDNA gene. The morphological analysis and partial sequencing of the 18S rDNA gene revealed the presence of three different species, Acanthamoeba castellanii, Acanthamoeba polyphaga, and Hartmannella vermiformis. Naegleria fowleri, Balamuthia mandrillaris, or Sappinia sp. was not isolated during the study. All A. castellanii and A. polyphaga sequence types were found to be genotype T4 that contains most of the pathogenic Acanthamoeba strains. The results indicated the occurrence and distribution of FLA species in tap water in these localities of Sivas, Turkey. Furthermore, the presence of temperature tolerant Acanthamoeba genotype T4 in tap water in the region must be taken into account for health risks.

  5. MINERAL WATER FROM SUPERMARKET VS. TAP WATER. SOME CONSIDERATIONS RELATED TO INNOCUITY

    Directory of Open Access Journals (Sweden)

    Ciprian – Nicolae POPA

    2015-04-01

    Full Text Available 15 Romanian brands of mineral water were purchased from hypermarket. For each of the 15 mineral waters were determined the content of nitrates, nitrites and pH. The data obtained were compared with the content of nitrates, nitrites and pH of the tap water collected in 15 locations in Bucharest, according to data released by the Apa Nova operator. The results showed that the mean of tap water pH in Bucharest, although slightly higher than the tested mineral waters pH, did not differ significantly from the mean of mineral waters pH, being situated in the alkaline domain. The mean content of nitrates in tap water in Bucharest, did not differ significantly from that of the tested mineral waters (t = 0.811. Nitrates content of tap water in Bucharest was significantly distinct less, as the pH was higher (r = 0.68**. Basically, the change in pH by one unit, lowers the amount of nitrate by 46%. Bucharest tap water nitrites content was significantly lower than that of tested mineral waters (0.005 mg/l to 0.0124; t = 2.674*. Basically, Bucharest tap water contained up to 2.5 times less nitrites than the nitrites mean of tested mineral waters.

  6. Contribution of radon in tap water to indoor radon concentrations

    International Nuclear Information System (INIS)

    Gesell, T.F.; Prichard, H.M.

    1980-01-01

    The contribution of radon ( 222 Rn) in domestic water supplies to the concentration of 222 Rn in indoor atmospheres has been investigated and found to be significant for concentrations over a few thousand picocuries per liter in the water supply. A model predicting average indoor increments due to this source is presented and supported by a series of measurements made in the laboratory and in private homes in the vicinity of Houston, Texas. The efficiency with which radon is transferred from water to air was experimentally determined, and these efficiencies were combined with estimates of average indoor water use to produce a source term proportional to the concentration of 222 Rn in the tap water. The importance of the dwelling volume and the air change rate is discussed

  7. Quality comparison of tap water vs. bottled water in the industrial city of Yanbu (Saudi Arabia).

    Science.gov (United States)

    Ahmad, Maqbool; Bajahlan, Ahmad S

    2009-12-01

    This study was conducted to compare the quality of bottled water with potabilized desalinated tap water. Fourteen brands of local and imported bottled water samples were collected from the local market and analyzed for physicochemical parameters in the Royal Commission Environmental Laboratory. Results were compared with 5-year continuous monitoring data of tap water from different locations in Madinat Yanbu Al-Sinaiyah (MYAS) including storage tanks of desalination plant. Results show that there was no significant difference in the quality of tap water and bottled water. Bacteriological test was never found positive in the 5-year data in tap water. Similarly, physicochemical analysis shows the persistent quality of tap water. Based on hardness analysis, bottled and tap water are categorized as soft water. Trihalomethanes (THMs) study also indicates that traces of disinfection by products (DBPs) are present in both tap and bottled water and are much less than the World Health Organization and Environmental Protection Agency maximum permissible limits. It is also important to note that the tap water distribution network in MAYS is a high-pressure recirculation network and there is no chance to grow bacteria in stagnant water in pipe lines or houses. Recently, the Royal Commission has replaced the whole drinking water network, which was made of asbestos-cemented pipes with glass-reinforced plastic (GRP) pipes, to avoid any asbestos contaminations. Based on these results, it is concluded that drinking water distributed in the city is of very good and persistent quality, comparable with bottled water. Continuous monitoring also guarantees the safe drinking water to the community. Hence, it is the responsibility of the Royal Commission to encourage the peoples in the city to drink tap water as it is as good as bottled water even better than some of the brands and is monitored regularly. It is also much cheaper compared to bottled water and is available round the clock

  8. Growth-supporting activity for Legionella pneumophila in tap water cultures and implication of hartmannellid amoebae as growth factors.

    Science.gov (United States)

    Wadowsky, R M; Butler, L J; Cook, M K; Verma, S M; Paul, M A; Fields, B S; Keleti, G; Sykora, J L; Yee, R B

    1988-11-01

    Photosynthetic cyanobacteria, heterotrophic bacteria, free-living amoebae, and ciliated protozoa may support growth of Legionella pneumophila. Studies were done with two tap water cultures (WS1 and WS2) containing L. pneumophila and associated microbiota to characterize growth-supporting activity and assess the relative importance of the microbiota in supporting multiplication of L. pneumophila. The water cultures were incubated in the dark at 35 degrees C. The growth-supporting factor(s) was separated from each culture by filtration through 1-micron-pore-size membrane filters. The retentate was then suspended in sterile tap water. Multiplication of L. pneumophila occurred when both the retentate suspension and the filtrate from either culture were inoculated into sterile tap water. L. pneumophila did not multiply in tap water inoculated with only the filtrate, even though filtration did not reduce the concentration of L. pneumophila or heterotrophic bacteria in either culture. Growth-supporting activity of the retentate suspension from WS1 was inactivated at 60 degrees C but unaffected at 0, 25, and 45 degrees C after 30-min incubations. Filtration experiments indicated that the growth-supporting factor(s) in WS1 was 2 to 5 micron in diameter. Ciliated protozoa were not detected in either culture. Hartmannellid amoebae were conclusively demonstrated in WS2 but not in WS1. L. pneumophila multiplied in tap water inoculated with the amoebae (10(3)/ml) and the 1-micron filtrate of WS2. No multiplication occurred in tap water inoculated with the filtrate only. Growth-supporting activity for L. pneumophila may be present in plumbing systems; hartmannellid amoebae appear to be important determinants of multiplication of L. pneumophila in some tap water cultures.

  9. Radiostrontium in milk and tap water. Appendix D

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The New York City sample is a monthly composite of pasteurized milk purchased daily at retail stores. The monthly Sr-90 to calcium ratios for New York City since the inception of the sampling program in 1954 through the third quarter of 1980 are tabulated. Samples of New York City tap water are taken daily at EML so that by the end of the month, approximately 100 liters have been collected. The Sr-90 data since the inception of the program are presented. The available cesium-137 data expressed as the Cs-137 to Sr-90 ratio are given. A graphical presentation of the New York City Sr-90 data is also shown

  10. Zinc sacrificial anode behavior at elevated temperatures in sodium chloride and tap water environments

    International Nuclear Information System (INIS)

    Othman, Othman Mohsen

    2005-01-01

    Zinc sacrificial anode coupled to mild steel was tested in sodium chloride and tap water environments at elevated temperatures. The anode failed to protect the mild steel specimens in tap water environment at all temperatures specified for this study. This was partly due to the high resistivity of the medium. The temperature factor did not help to activate the anode in water tap medium. In sodium chloride environment the anode demonstrated good protection for steel cathodes. In tap water environment the anode weight loss was negligible. The zinc anode suffered intergranular corrosion in sodium chloride environment and this was noticed starting at 40 degree centigrade. In tap water environment the zinc anode demonstrated interesting behavior beyond 60 degree centigrade, that could be attributed to the phenomenon of reversal of potential at elevated temperatures. It also showed shallow pitting spots in tap water environment without any sign of intergranular corrosion. Zinc anodes would suffer intergranular corrosion at high temperatures. (author)

  11. Disparities in plain, tap and bottled water consumption among US adults: National Health and Nutrition Examination Survey (NHANES) 2007-2014.

    Science.gov (United States)

    Rosinger, Asher Y; Herrick, Kirsten A; Wutich, Amber Y; Yoder, Jonathan S; Ogden, Cynthia L

    2018-02-01

    Differences in bottled v. tap water intake may provide insights into health disparities, like risk of dental caries and inadequate hydration. We examined differences in plain, tap and bottled water consumption among US adults by sociodemographic characteristics. Cross-sectional analysis. We used 24 h dietary recall data to test differences in percentage consuming the water sources and mean intake between groups using Wald tests and multiple logistic and linear regression models. National Health and Nutrition Examination Survey (NHANES), 2007-2014. A nationally representative sample of 20 676 adults aged ≥20 years. In 2011-2014, 81·4 (se 0·6) % of adults drank plain water (sum of tap and bottled), 55·2 (se 1·4) % drank tap water and 33·4 (se 1·4) % drank bottled water on a given day. Adjusting for covariates, non-Hispanic (NH) Black and Hispanic adults had 0·44 (95 % CI 0·37, 0·53) and 0·55 (95 % CI 0·45, 0·66) times the odds of consuming tap water, and consumed B=-330 (se 45) ml and B=-180 (se 45) ml less tap water than NH White adults, respectively. NH Black, Hispanic and adults born outside the fifty US states or Washington, DC had 2·20 (95 % CI 1·79, 2·69), 2·37 (95 % CI 1·91, 2·94) and 1·46 (95 % CI 1·19, 1·79) times the odds of consuming bottled water than their NH White and US-born counterparts. In 2007-2010, water filtration was associated with higher odds of drinking plain and tap water. While most US adults consumed plain water, the source (i.e. tap or bottled) and amount differed by race/Hispanic origin, nativity status and education. Water filters may increase tap water consumption.

  12. Tap water nasal irrigation in adults with seasonal allergic rhinitis: a randomized double-blind study.

    Science.gov (United States)

    Xiong, Min; Fu, Xiaoyan; Deng, Wenting; Lai, Huangwen; Yang, Chuanhong

    2014-06-01

    Saline nasal irrigation is effective in the treatment of seasonal allergic rhinitis, and sodium chloride itself has no antiallergic effects. The mechanism of saline nasal irrigation depends mainly on washing away allergens and inflammatory mediators induced by allergic reactions. Tap water has the same washing effects as saline. In this study, it was investigated if tap water nasal irrigation was effective in the treatment of seasonal allergic rhinitis. Sixty-four patients diagnosed with seasonal allergic rhinitis were enrolled. Patients were randomized to tap water nasal irrigation group and non-tap water nasal irrigation group for treatment. Patients of both groups were treated with desloratadine. Treatment outcomes were measured using allergic rhinitis Quality of Life (QoL) survey was completed at baseline and after 3 weeks of therapy. There were statistically significant differences in QoL scores between tap water nasal irrigation group and non-tap water nasal irrigation group. The tap water nasal irrigation group had better QoL scores than the non-tap water nasal irrigation group. Tap water nasal irrigation can be a valuable adjuvant therapy for patients with seasonal allergic rhinitis.

  13. Tap water iontophoresis in the treatment of pediatric hyperhidrosis.

    Science.gov (United States)

    Dagash, Haitham; McCaffrey, Sinead; Mellor, Katie; Roycroft, Agnes; Helbling, Ingrid

    2017-02-01

    The treatment options for localized hyperhidrosis include antiperspirants, anticholinergics, iontophoresis, botulinum toxin and surgery. Tap water iontophoresis (TWI) involves immersing the affected area in tap water and passing a small electrical current through the area. Our aim was to assess the success of this therapy in a pediatric cohort. Retrospective case note review of all patients younger than 18years who underwent TWI between 2002 and 2015. Demographic data, number of treatment sessions, side effects and overall success were analyzed. Individuals undergo 7 treatments over 4weeks. A positive outcome was determined as an improvement in symptoms. Pre- and posttreatment hyperhidrosis disease severity scale (HDSS) was measured. Data are presented as mean (range). Statistical analysis was by paired t-test. A P value of hyperhidrosis (PPH) was present in 39/43 (91%) patients. Axillary hyperhidrosis (AH) was present in 19/43 (44%) patients. All patients (with the exception of one) underwent 7 sessions (5-7). Side effects included paresthesia (88%), pruritus (26%), pain (26%), erythema (14%), dryness (12%) as well as vesicle formation and abrasions in one patient (2%). A positive outcome was found in 84% (36/43) of patients. There was a significant reduction in mean HDSS (pre 3.5 vs. post 2; P=0.0001). TWI is a safe and effective modality of treatment for both PPH and AH in the pediatric population, with minimal side effects. Pediatric surgeons should offer this treatment option before considering more invasive surgical procedures. IV: Retrospective study. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

  14. Water conservation in surgery: a comparison of two surgical scrub techniques demonstrating the amount of water saved using a 'taps on/taps off' technique.

    Science.gov (United States)

    Petterwood, Joshua; Shridhar, Vivek

    2009-08-01

    Australia finds itself in the grip of its worst drought on record. The surgical profession has a responsibility to conserve water where possible. We tried to show how much water we saved through the simple measure of turning taps off while not in use during the surgical scrub. We conducted a prospective analysis of two different scrub techniques at the Gold Coast Hospital in Queensland, Australia. Ten participants completed two 5-min scrubs using standard 'elbow on' taps. In the first, they left the taps running throughout the scrub; in the second, they turned the taps on and off so that water ran only when rinsing the hands. Water was collected and the amount of time the hands spent under running water was recorded. Amount of water used during the surgical scrub. A mean of 15.5 L was used during the 'taps on' scrub, with participants spending a mean of 47 s rinsing the hands. During the 'taps on/off' scrub, participants used a mean of 4.5 L, spending 40 s rinsing the hands. This represents a water saving of 11 L or 71% for each scrub (P technique is a simple and effective way of conserving large amounts of water during the surgical scrub. The technique should be adopted as standard practice.

  15. Trihalomethane concentrations in tap water as determinant of bottled water use in the city of Barcelona.

    Science.gov (United States)

    Font-Ribera, Laia; Cotta, Jordi Colomer; Gómez-Gutiérrez, Anna; Villanueva, Cristina M

    2017-08-01

    Bottled water consumption is increasing worldwide, despite its huge economic and environmental cost. We aim to describe personal and tap water quality determinants of bottled water use in the city of Barcelona. This cross-sectional study used data from the Health Survey of Barcelona in 2006 (N=5417 adults). The use of bottled water to drink and to cook was evaluated in relation to age, gender, educational level, district and levels of trihalomethanes (THMs), free chlorine, conductivity, chloride, sodium, pH, nitrate and aluminium in municipal tap water using Robust Poisson Regression. The prevalence of bottled water use to drink and cook was 53.9% and 6.7%, respectively. Chemical parameters in water had a large variability (interquartile range of THMs concentrations: 83.2-200.8μg/L) and were correlated between them, except aluminium. Drinking bottled water increased with educational level, while cooking with bottled water was higher among men than among women and decreased with age. After adjusting by these personal determinants, a dose-response relationship was found between concentrations of all chemicals except aluminium in tap water and bottled water use. The highest association was found for THMs, with a Prevalence Ratio of 2.00 (95%CI=1.86, 2.15) for drinking bottled water and 2.80 (95%CI=1.72, 4.58) for cooking with bottled water, among those with >150μg/L vs. tap water. More than half of Barcelona residents regularly drank bottled water, and the main determinant was the chemical composition of tap water, particularly THM level. Copyright © 2017. Published by Elsevier B.V.

  16. The role of domestic tap water in Acanthamoeba contamination in contact lens storage cases in Korea

    Science.gov (United States)

    Jeong, Hae Jin

    2005-01-01

    A survey was carried out from August to December 2004 in Pusan, Korea to document the presence of free-living amoeba (FLA), including the genus Acanthamoeba, in both contact lens storage cases and domestic tap water. Acanthamoeba was isolated from 5 (4.2%) in 120 contact lens storage cases. Four house tap water samples from residents, whose contact lens storage cases had been contaminated by Acanthamoeba, were also found to be contaminated with Acanthamoeba. Therefore, the contamination rate of FLA and Acanthamoeba in domestic tap water was investigated in order to examine the role of domestic tap water in Acanthamoeba contamination of contact lens storage cases. FLA and Acanthamoeba were identified in 97 (46.8%) and 16 (7.7%) of the 207 domestic tap water samples, respectively. There were no significant differences between the contamination rates of FLA in tap water according to the filtration plant of origin. No FLA was detected in the tap water directly supplied by the water purification plants. Water storage tanks appear to promote FLA colonization, including Acanthamoeba, in domestic tap water. This increases the risk of Acanthamoeba contamination in contact lens storage cases as well as increasing the risk of Acanthamoeba keratitis. PMID:15951638

  17. Risk Factors Associated with the Choice to Drink Bottled Water and Tap Water in Rural Saskatchewan

    Directory of Open Access Journals (Sweden)

    Lianne McLeod

    2014-01-01

    Full Text Available A cross-sectional study investigated risk factors associated with choices to drink bottled water and tap water in rural Saskatchewan. Of 7,500 anonymous postal questionnaires mailed out, 2,065 responses were analyzed using generalized linear mixed models. Those who reported a water advisory (p < 0.001 or living in the area for £10 years (p = 0.01 were more likely to choose bottled water. Those who reported tap water was not safe to drink were more likely to choose bottled water, an effect greater for those who had no aesthetic complaints (p ≤ 0.001, while those with aesthetic complaints were more likely to choose bottled water if they believed the water was safe (p < 0.001. Respondents who treated their water and did not use a community supply were more likely to choose bottled water (p < 0.001, while those who did not treat their water were more likely to choose bottled water regardless of whether a community supply was used (p < 0.001. A similar pattern of risk factors was associated with a decreased likelihood of consuming tap water daily; however, the use of a community water supply was not significant. Understanding the factors involved in drinking water choices could inform public health education efforts regarding water management in rural areas.

  18. Hydrogen evolution on nickel electrode in synthetic tap water - alkaline solution

    NARCIS (Netherlands)

    Petrov, Yanko; Schosger, Jean-Pierre; Stoynov, Zdravko; de Bruijn, Frank

    2011-01-01

    The effect of tap water contaminants on the kinetics of the hydrogen evolution reaction on a nickel electrode in 1 mol dm(-3) KOH was investigated by galvanostatic polarization and electrochemical impedance spectroscopy techniques. It was found that the tap water contaminants lead to an increase in

  19. Cryptosporidium: A Guide to Water Filters

    Science.gov (United States)

    ... Cryptosporidium Tracking in the United States CryptoNet Healthy Water Sites Healthy Water Drinking Water Healthy Swimming Global ... lt;/label> Parasites Home A Guide to Water Filters Recommend on Facebook Tweet Share Compartir Filtering ...

  20. Regional Assessment of Recharge Elevation of Tap Water Sources Using the Isoscape Approach

    OpenAIRE

    Yamanaka, Tsutomu; Yamada, Yuki

    2017-01-01

    The importance of mountains as “natural water towers” has been quantified by comparing water budgets in upstream (mountain) and downstream (lowland) areas, but their importance for tap water supplies has not been assessed. Here, we propose an isoscape approach to estimate the mean recharge elevation of tap water sources (rivers, reservoirs, springs, and wells) and apply it to a region in central Japan as a case study. Errors in the estimation of mean recharge elevation were estimated at 90–14...

  1. The occurrence of antibiotic resistance genes in tap water - a review

    Science.gov (United States)

    Siedlecka, Agata

    2018-02-01

    The study presents a review of the occurrence of genetic determinants of antibiotic resistance in tap water. The aim of this study was also to compare the applied methods for antibiotic resistance genes (ARGs) investigations in tap water. As the concentration of ARGs in treated, drinking water is expected to be very low and may cause problems in a standard isolation procedure, the special emphasis is placed on the applied procedures of DNA extraction and their efficiency. The study presents the first attempts to obtain DNA directly from tap water. Further efforts must be put to determine the final amount of obtained DNA and the presence of chosen ARGs among the molecules.

  2. Comparison of filtering methods, filter processing and DNA extraction kits for detection of mycobacteria in water

    Directory of Open Access Journals (Sweden)

    Marija Kaevska

    2015-09-01

    Full Text Available Introduction and objective. Mycobacteria have been isolated from almost all types of natural waters, as well as from man-made water distribution systems. Detection of mycobacteria using PCR has been described in different types of water; however, currently, there is no standardised protocol for the processing of large volumes of water. Material and Methods. In the present study, different filtering methods are tested and optimised for tap or river water filtration up to 10 L, as well as filter processing and DNA isolation using four commercially available kits. Results. The PowerWater DNA isolation kit (MoBio, USA, together with a kit used for soil and other environmental samples (PowerSoil DNA isolation kit, MoBio, had the highest efficiency. Filtration of 10 L of water and elution of the filter in PBS with the addition of 0.05% of Tween 80 is suggested. Conclusions. The described protocol for filter elution is recommended, and the use of the PowerWater DNA isolation kit for the highest mycobacterial DNA yield from water samples. The described protocol is suitable for parallel detection of mycobacteria using cultivation.

  3. Fluoride Intake through Consumption of Tap Water and Bottled Water in Belgium

    Directory of Open Access Journals (Sweden)

    Herman van Oyen

    2009-05-01

    Full Text Available There is a tendency to align higher levels of fluoride in natural mineral water with the existing higher levels in tap water. Treatment of natural mineral waters could harm the preservation of their natural character. In this study fluoride intake through bottled and tap water consumption in the Belgian adult population was assessed, taking into account regional differences. A deterministic approach was used whereby consumption quantities of tap water and different brands of bottled water were linked with their respective fluoride concentrations. Data from the national food consumption survey (2004 were used and the Nusser methodology was applied to obtain usual intake estimates. Mean intake of fluoride through total water consumption in Flanders was 1.4±0.7 mg/day (97.5th percentile: 3.1 mg/day, while in the Walloon region it was on average 0.9±0.6 mg/day (97.5th percentile: 2.4 mg/day. The probability of exceeding the UL of 7 mg per day via a normal diet was estimated to be low. Consequently, there is no need to revise the existing norms, but higher fluoride concentrations should be more clearly indicated on the labels. Reliable data about total dietary fluoride intake in children, including intake of fluoride via tooth paste and food supplements, are needed.

  4. Inorganic chemical quality of European tap-water: 2. Geographical distribution

    International Nuclear Information System (INIS)

    Flem, B.; Reimann, C.; Birke, M.; Banks, D.; Filzmoser, P.; Frengstad, B.

    2015-01-01

    Highlights: • European scale comparison of tap water. • 579 tap water samples have been analyses for more than 60 parameters. • Chemical geographical distribution. • Water treatment processes. • Importance of geology on tap water quality. - Abstract: 579 tap water samples were collected at the European scale and analysed at a single laboratory for more than 60 parameters. This dataset is analysed here in terms of the spatial and national distribution of the analysed inorganic chemical parameters. The distribution of most parameters is controlled by various artificial and natural factors (land use, distribution network, water source and treatment, geographical location and geology). The distribution of nitrate can be interpreted in terms of land use and climate. Water treatment affects the distribution of phosphorus in tap water; especially the policy of adding phosphate to potable water in the UK to suppress plumbosolvency. The distribution of alkalinity, Ca, Mg, Sr and Li appears to reflect both water source (low in surface waters) and the geological contrast between base-poor crystalline rock terrains and carbonate rich sedimentary rock. The Scandinavian nations’ tap water shows the highest concentrations of most of the rare earth elements, probably reflecting their geological availability and mobility in low pH raw water sources. The distribution of fluoride, uranium and arsenic also appear to exhibit geological and source (groundwater versus surface water) controls. Hungary returns several high As results, which may reflect As-rich reducing groundwaters of the Pannonian basin. Much Estonian tap water reflects a very specific hydrochemical environment, namely Palaeozoic near-coastal aquifers, which yield deep, reducing or saline groundwater (possibly influenced by marine intrusion), enriched in Ba, B, Br − , Cl − , Eu, F − , I, Li, K, Mn and Na

  5. Yeasts and filamentous fungi in bottled mineral water and tap water from municipal supplies

    Directory of Open Access Journals (Sweden)

    Mirian Ueda Yamaguchi

    2007-01-01

    Full Text Available The main objective of this study was to analyse the occurrence of yeasts and filamentous fungi in drinking water as well as to investigate their correlation with the indicator bacteria of faecal pollution. Yeasts were detected in 36.6% and 11.6% of the bottled mineral on water dispensers and tap water samples from municipal system, respectively. Twenty-one (35.0% of bottled mineral water and two (3.3% of tap water samples were positive for filamentous fungi. For bottled mineral water 12 (20.0% of 60 samples were positive for total coliform, compared with 3(5.0%out of 60 samples from tap water. The mineral water from dispensers was more contaminated than tap water. Strains belonging to the genera Candida identified to the species level were C. parapsilosis, C. glabrata and C. albicans. Thus, bottled mineral water from water dispensers and tap water could be considered a possible transmission route for filamentous fungi and yeasts, and could constitute a potential health hazard, mainly to immunocompromised indivuals.O principal objetivo do presente estudo foi avaliar a prevalência de leveduras e fungos filamentosos em água potável, bem como investigar suas correlações com bactérias indicadoras de contaminação fecal. Leveduras foram detectadas em 36,6% e 11,6% das amostras de água mineral de garrafão em dispensadores de água e água de torneira do sistema municipal, respectivamente. Vinte e uma (35,5% das amostras de água mineral de garrafão e duas (3,3% das amostras de água de torneira foram positivas para fungos filamentosos. Para água mineral de garrafão, 12 (20.0% das 60 amostras foram positivas para coliforme total, comparado com 3 (5.0% das 60 amostras de água de torneira. A água coletada de garrafões de água mineral dos dispensadores foi marcadamente mais contaminada que as amostras de água de torneira. Candida spp identificadas ao nível de espécie foram C. parapsilosis, C. glabrata e C. albicans. Como está sendo

  6. Perfluoroalkyl and polyfluoroalkyl substances (PFASs) in mineral water and tap water.

    Science.gov (United States)

    Gellrich, Vanessa; Brunn, Hubertus; Stahl, Thorsten

    2013-01-01

    The aims of the present study were to determine PFAS (perfluoroalkyl and polyfluoroalkyl substances) concentrations in various sources of water intended for human consumption, use these data to calculate the possible uptake via water as well as to estimate the water related health risk to consumers. A total of 177 water samples (119 mineral waters, 26 tap water samples, 18 spring water samples and 14 raw (untreated) water samples) were analyzed using liquid chromatography tandem mass spectrometry for the presence of 10 or 19 PFASs, respectively. PFAS concentrations above the limit of detection of 1 ng/L were found in 52% of all samples. Short-chain PFASs with less than 8 carbon atoms were responsible for 58% of the total PFAS contamination. The highest concentration (sum of PFASs) of 42.7 ng/L was detected in tap water. The calculated maximum uptake of both components for which a tolerable daily intake (TDI) level exists were 0.17 ng/kg bodyweight/day for PFOS (perfluorooctane sulfonic acid) and 0.21 ng/kg bodyweight/day for PFOA (perfluorooctane carboxylic acid). In regard to the model calculations made here (TDI for adults and for infants), the uptake of PFOS and PFOA via consumption of water can be considered negligible. Supplemental materials are available for this article. Go to the publisher's online edition of Journal of Environmental Science and Health, Part A to view the supplemental file.

  7. Genotypic diversity and antibiotic resistance in Sphingomonadaceae isolated from hospital tap water.

    Science.gov (United States)

    Narciso-da-Rocha, Carlos; Vaz-Moreira, Ivone; Manaia, Célia M

    2014-01-01

    The aim of this study was to infer about the modes and extent of dispersion of Sphingomonadaceae via tap water. Sphingomonadaceae isolated from tap water samples in different places of a hospital were compared, based on intra-species genetic variability and antibiotic resistance phenotypes. These isolates were also compared with others isolated before from houses and dental chairs, served by the same municipal water supply system. Sphingomonadaceae from hospital tap water comprised members of the genera Sphingomonas, Sphingobium, Novosphingobium and Blastomonas. In general, distinct genotypes of Sphingomonadaceae were detected in different hospital areas and in tap water outside the hospital, suggesting these bacteria are not persistent or widespread in the urban water distribution system. Possible intrinsic antibiotic resistance, observed in most or all members of the family or of a genus, was observed for colistin in Sphingomonadaceae, aminoglycosides in the genus Blastomonas and beta-lactams in the genus Sphingobium. Possible acquired resistance phenotypes, not common to all members of a given species, comprised fluoroquinolones, cephalosporins and sulphonamides. Although the potential of Sphingomonadaceae as opportunistic pathogens may be low, the capacity of these bacteria to thrive in water supply systems, combined with the intrinsic or acquired antibiotic resistance, may raise the risk associated with their occurrence in hospital tap water. © 2013 Elsevier B.V. All rights reserved.

  8. Longitudinal and Source-to-Tap New Orleans, LA, U.S.A. Drinking Water Microbiology.

    Science.gov (United States)

    Hull, Natalie M; Holinger, Eric P; Ross, Kimberly A; Robertson, Charles E; Harris, J Kirk; Stevens, Mark J; Pace, Norman R

    2017-04-18

    The two municipal drinking water systems of New Orleans, LA, U.S.A. were sampled to compare the microbiology of independent systems that treat the same surface water from the Mississippi River. To better understand temporal trends and sources of microbiology delivered to taps, these treatment plants and distribution systems were subjected to source-to-tap sampling over four years. Both plants employ traditional treatment by chloramination, applied during or after settling, followed by filtration before distribution in a warm, low water age system. Longitudinal samples indicated microbiology to have stability both spatially and temporally, and between treatment plants and distribution systems. Disinfection had the greatest impact on microbial composition, which was further refined by filtration and influenced by distribution and premise plumbing. Actinobacteria spp. exhibited trends with treatment. In particular, Mycobacterium spp., very low in finished waters, occurred idiosyncratically at high levels in some tap waters, indicating distribution and/or premise plumbing as main contributors of mycobacteria. Legionella spp., another genus containing potential opportunistic pathogens, also occurred ubiquitously. Source water microbiology was most divergent from tap water, and each step of treatment brought samples more closely similar to tap waters.

  9. Investigation of Natural Radioactivity in the Tap and Spring Water in Yaounde Town, Cameroon

    International Nuclear Information System (INIS)

    Lydie, R.M.; Hakam, O.K.; Choukri, A.; Lydie, R.M.; Hakam, O.K.; Choukri, A.

    2013-01-01

    The natural radionuclide concentrations in the tap and springs water in Yaounde town, capital of Cameroon with a population of 3.5 million inhabitants were estimated by gamma spectrometry, using both well calibrated Canberra NaI(Tl) and HPGe detector systems. Tap water samples were collected during the dry and the rainy seasons, respectively in December 2002 and July 2003 and spring water samples were collected in August 2010. The radionuclides observed with regularity belonged to the series decay naturally occurring radionuclides headed by 238 U and 232 Th as well as the non-series nuclide 40 K. Assuming an individual daily consumption of 1 litre of water, the average annual intake for these populations is 3821 Bq/y for tap water and 1161 Bq/y for spring water.

  10. Evaluation of on-line concentration coupled to liquid chromatography tandem mass spectrometry for the quantification of neonicotinoids and fipronil in surface water and tap water.

    Science.gov (United States)

    Montiel-León, Juan Manuel; Duy, Sung Vo; Munoz, Gabriel; Amyot, Marc; Sauvé, Sébastien

    2018-03-05

    A study was initiated to investigate a fast and reliable method for the determination of selected systemic insecticides in water matrixes and to evaluate potential sources of bias in their analysis. Acetamiprid, clothianidin, desnitro-imidacloprid, dinotefuran, fipronil, imidacloprid, nitenpyram, thiacloprid, and thiamethoxam were amenable to analysis via on-line sample enrichment hyphenated to ultra-high-performance liquid chromatography tandem mass spectrometry. The selection of on-line solid-phase extraction parameters was dictated by a multicriterion desirability approach. A 2-mL on-line injection volume with a 1500 μL min -1 loading flow rate met the objectives sought in terms of chromatographic requirements, extraction efficiency, sensitivity, and precision. A total analysis time of 8 min per sample was obtained with method limits of detection in the range of 0.1-5 ng L -1 for the scope of targeted analytes. Automation at the sample concentration step yielded intraday and interday precisions in the range of 1-23 and 2-26%, respectively. Factors that could affect the whole method accuracy were further evaluated in matrix-specific experiments. The impact of the initial filtration step on analyte recovery was evaluated in ultra-pure water, tap water, and surface water. Out of the nine membranes tested, glass fiber filters and polyester filters appeared as the most appropriate materials. Sample storage stability was also investigated across the three matrix types; the targeted analytes displayed suitable stability during 28 days at either 4 °C or - 20 °C, with little deviations (± 10%) with respect to the initial T 0 concentration. Method applicability was demonstrated in a range of tap water and surface water samples from the province of Québec, Canada. Results from the present survey indicated a predominance of thiamethoxam (tap water and river water, respectively), clothianidin (tap water and river water, respectively), and imidacloprid (tap

  11. Evaluating a Tap Water Contamination Incident Attributed to Oil Contamination by Nontargeted Screening Strategies.

    Science.gov (United States)

    Wang, Beili; Wan, Yi; Zheng, Guomao; Hu, Jianying

    2016-03-15

    The present study applied nontargeted screening techniques as a novel approach to evaluate the tap water samples collected during the "4.11" tap water pollution incident occurred on April 11, 2014 in Lanzhou in west China. Multivariate analysis (PCA and OPLS-DA) of about 3000 chemical features obtained in extracts of tap water samples by ultrahigh-pressure liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) analysis showed significantly different chemical profiles in tap water from pollution regions versus reference regions during the event. These different chemical profiles in samples from different regions were not observed in samples collected during the nonpollution period. The compounds responsible for the differences in profiles between regions were identified as naphthenic acids (NAs) and oxidized NAs (oxy-NAs) after the sample extracts underwent bromination to explore saturations, dansylation to identify hydroxylations and corresponding MS/MS mode analysis. A consistent finding was further observed in the targeted analysis of NA mixtures, demonstrating that the Lanzhou "4.11" tap water pollution incident could be attributed to oil spill pollution, and NA mixtures would be a marker for oil contamination. Such evaluations can help to rapidly discriminate pollution sources in accidental pollution events and contribute to regular water monitoring management of water safety issues.

  12. The occurrence of Aeromonas in drinking water, tap water and the Porsuk River

    Directory of Open Access Journals (Sweden)

    Merih Kivanc

    2011-03-01

    Full Text Available The occurrence of Aeromonas spp. in the Porsuk River, public drinking water and tap water in the City of Eskisehir (Turkey was monitored. Fresh water samples were collected from several sampling sites during a period of one year. Total 102 typical colonies of Aeromonas spp. were submitted to biochemical tests for species differentiation and of 60 isolates were confirmed by biochemical tests. Further identifications of isolates were carried out first with the VITEK system (BioMe˜rieux and then selected isolates from different phenotypes (VITEK types were identified using the DuPont Qualicon RiboPrinter® system. Aeromonas spp. was detected only in the samples from the Porsuk River. According to the results obtained with the VITEK system, our isolates were 13% Aeromonas hydrophila, 37% Aeromonas caviae, 35% Pseudomonas putida, and 15% Pseudomonas acidovorans. In addition Pseudomonas sp., Pseudomonas maltophila, Aeromonas salmonicida, Aeromonas hydrophila, and Aeromonas media species were determined using the RiboPrinter® system. The samples taken from the Porsuk River were found to contain very diverse Aeromonas populations that can pose a risk for the residents of the city. On the other hand, drinking water and tap water of the City are free from Aeromonas pathogens and seem to be reliable water sources for the community.

  13. Disparity in disinfection byproducts concentration between hot and cold tap water.

    Science.gov (United States)

    Liu, Boning; Reckhow, David A

    2015-03-01

    The quality of water entering a distribution system may differ substantially from the quality at the point of exposure to the consumer. This study investigated temporal variations in the levels of regulated and non-regulated disinfection byproducts (DBPs) in cold and hot tap water in a home on a medium-sized municipal water system. In addition, samples were collected directly from the water plant with some being held in accordance with a simulated distribution system (SDS) test protocol. The location for this work was a system in western Massachusetts, USA that uses free chlorine as a final disinfectant. Very little short term variability of DBPs at the point of entry (POE) was observed. The concentration of DBPs in the time-variable SDS test was similar to concentrations in the cold water tap. For most DBPs, the concentrations continued to increase as the cold water tap sample was held for the time-variable SDS incubation period. However, the impact of heating on DBP levels was compound specific. For example, the concentrations of trihalomethanes (THMs), dichloroacetic acid (DCAA) and chloropicrin (CP) were substantially higher in the hot water tap than in the cold water time-variable SDS samples. In contrast, the concentration of trichloroacetic acid (TCAA) was lower in the heated hot tap water, but about equal to that observed in the cold tap water. The situation was more pronounced for dichloroacetonitrile (DCAN), bromodichloroacetic acid (BDCAA), bromochloroacetic acid (BCAA) and 1,1,1-trichloropropanone (TCP), which all showed lower concentrations in the hot water then in either of the cold water samples (instantaneous or time-variable SDS). The latter was viewed as a clear indication of thermally-induced decomposition. The ratio of unknown total organic halide (UTOX) to TOX was substantially lower in the hot tap water as the THM to TOX ratio became correspondingly larger. The results of this study show that DBP exposure in the home is not well represented by

  14. Determination of four fluoroquinolone antibiotics in tap water in Guangzhou and Macao

    International Nuclear Information System (INIS)

    Yiruhan; Wang Qiaojun; Mo Cehui; Li Yanwen; Gao Peng; Tai Yiping; Zhang Yan; Ruan Zhili; Xu Jiawei

    2010-01-01

    Four fluoroquinolone antibiotics (norfloxacin, ciprofloxacin, lomefloxacin, and enrofloxacin) in tap water in Guangzhou and Macao were analyzed using high performance liquid chromatography fluorescence detection. The results showed that all target antibiotics were detected in high rate both in Guangzhou (77.5%) and Macao (100%), ranging from 1.0 to 679.7 ng/L (SD ≤ 37.6) in Guangzhou, and from 2.0 to 37.0 ng/L (SD ≤ 2.5) in Macao. The fluoroquinolone antibiotics pollution in tap water widely distributes in Guangzhou and Macao. In addition, the effect of rainfall on concentration of fluoroquinolone antibiotics in south China was also investigated. Our result indicates that the antibiotic concentration in tap water in Guangzhou tends to obviously reduce at the beginning of rainy season, even decreases below the limit of quantification immediately. Thus, it was clarified that the heavy rain in south China has the function of reducing the fluoroquinolone antibiotics concentrations in tap water. - The antibiotics were detected in the tap water in Guangzhou and Macao using our developed method for fluoresence detection with high performance liquid chromatography

  15. Determination of four fluoroquinolone antibiotics in tap water in Guangzhou and Macao

    Energy Technology Data Exchange (ETDEWEB)

    Yiruhan; Wang Qiaojun [Department of Environmental Engineering, Jinan University, Huangpudadaoxi 601, Guangzhou 510632 (China); Mo Cehui, E-mail: tchmo@jnu.edu.c [Department of Environmental Engineering, Jinan University, Huangpudadaoxi 601, Guangzhou 510632 (China); Li Yanwen; Gao Peng; Tai Yiping; Zhang Yan; Ruan Zhili; Xu Jiawei [Department of Environmental Engineering, Jinan University, Huangpudadaoxi 601, Guangzhou 510632 (China)

    2010-07-15

    Four fluoroquinolone antibiotics (norfloxacin, ciprofloxacin, lomefloxacin, and enrofloxacin) in tap water in Guangzhou and Macao were analyzed using high performance liquid chromatography fluorescence detection. The results showed that all target antibiotics were detected in high rate both in Guangzhou (77.5%) and Macao (100%), ranging from 1.0 to 679.7 ng/L (SD {<=} 37.6) in Guangzhou, and from 2.0 to 37.0 ng/L (SD {<=} 2.5) in Macao. The fluoroquinolone antibiotics pollution in tap water widely distributes in Guangzhou and Macao. In addition, the effect of rainfall on concentration of fluoroquinolone antibiotics in south China was also investigated. Our result indicates that the antibiotic concentration in tap water in Guangzhou tends to obviously reduce at the beginning of rainy season, even decreases below the limit of quantification immediately. Thus, it was clarified that the heavy rain in south China has the function of reducing the fluoroquinolone antibiotics concentrations in tap water. - The antibiotics were detected in the tap water in Guangzhou and Macao using our developed method for fluoresence detection with high performance liquid chromatography

  16. Tap Water Versus Sterile Normal Saline in Wound Swabbing: A Double-Blind Randomized Controlled Trial.

    Science.gov (United States)

    Chan, Mun Che; Cheung, Kin; Leung, Polly

    2016-01-01

    The use of tap water as a wound-cleansing agent is becoming more common in clinical practice, especially in community settings. The aim of this study was to test whether there are differences in wound infection and wound healing rates when wounds are cleansed with tap water or sterile normal saline. Double-blinded randomized controlled trial. Subjects were recruited from the community nursing service of a local hospital in Hong Kong. The target sample included subjects who were aged 18 years or more, and receiving chronic or acute wound care treatment. Subjects were randomly assigned to wound cleansing with tap water (experimental group) or sterile normal saline (control group). Wound assessment was conducted at each home visit, and an assessment of wound size was conducted once a week. The main outcome measures, occurrence of a wound infection and wound healing, were assessed over a period of 6 weeks. Twenty-two subjects (11 subjects in each group) with 30 wounds participated in the study; 16 wounds were managed with tap water cleansing and 14 were randomly allocated to management with the sterile normal saline group. Analysis revealed no significant difference between the experimental and control groups in the proportions of wound infection and wound healing. Study findings indicate that tap water is a safe alternative to sterile normal saline for wound cleansing in a community setting.

  17. The occurrence of antibiotic resistance genes in tap water – a review

    Directory of Open Access Journals (Sweden)

    Siedlecka Agata

    2018-01-01

    Full Text Available The study presents a review of the occurrence of genetic determinants of antibiotic resistance in tap water. The aim of this study was also to compare the applied methods for antibiotic resistance genes (ARGs investigations in tap water. As the concentration of ARGs in treated, drinking water is expected to be very low and may cause problems in a standard isolation procedure, the special emphasis is placed on the applied procedures of DNA extraction and their efficiency. The study presents the first attempts to obtain DNA directly from tap water. Further efforts must be put to determine the final amount of obtained DNA and the presence of chosen ARGs among the molecules.

  18. Levels of major and trace elements, including rare earth elements, and ²³⁸U in Croatian tap waters.

    Science.gov (United States)

    Fiket, Željka; Rožmarić, Martina; Krmpotić, Matea; Benedik, Ljudmila

    2015-05-01

    Concentrations of 46 elements, including major, trace, and rare earth elements, and (238)U in Croatian tap waters were investigated. Selected sampling locations include tap waters from various hydrogeological regions, i.e., different types of aquifers, providing insight into the range of concentrations of studied elements and (238)U activity concentrations in Croatian tap waters. Obtained concentrations were compared with the Croatian maximum contaminant levels for trace elements in water intended for human consumption, as well as WHO and EPA drinking water standards. Concentrations in all analyzed tap waters were found in accordance with Croatian regulations, except tap water from Šibenik in which manganese in concentration above maximum permissible concentration (MPC) was measured. Furthermore, in tap water from Osijek, levels of arsenic exceeded the WHO guidelines and EPA regulations. In general, investigated tap waters were found to vary considerably in concentrations of studied elements, including (238)U activity concentrations. Causes of variability were further explored using statistical methods. Composition of studied tap waters was found to be predominately influenced by hydrogeological characteristics of the aquifer, at regional and local level, the existing redox conditions, and the household plumbing system. Rare earth element data, including abundances and fractionation patterns, complemented the characterization and facilitated the interpretation of factors affecting the composition of the analyzed tap waters.

  19. Tests of some methods to remove I-131 from contaminated tap water

    International Nuclear Information System (INIS)

    Tagami, Keiko; Uchida, Shigeo

    2011-01-01

    Following the Fukushima Daiichi Nuclear Power Plant accident, iodine-131 concentrations in tap water higher than 100 Bq L -1 were reported by several local governments in the Kanto Plain in March 2011. To remove iodine-131 from tap water, five methods were tested in this study, that is, (1) boiling, (2) adding charcoals from oak or bamboo, (3) activated charcoals, (4) water purifiers, and (5) reverse osmosis (RO) treatments. Boiling was shown to be not effective in removing iodine-131 from tap water; indeed even higher concentrations may result from the liquid-volume reduction accompanying this process. Adding charcoals and activated charcoal treatment could not remove iodine-131, because no reduction of iodine-131 was observed in tap water samples after these treatments. Only limited effect was found with water purifiers with first several portions; no effect was expected with further water treatment. On the other hand, the RO showed high iodine-131 removal percentage of more than 95%, although the method needs about 5-10 L water to obtain 1 L of RO treated water. (author)

  20. Perfluoroalkyl acids (PFAAs) in the Pra and Kakum River basins and associated tap water in Ghana.

    Science.gov (United States)

    Essumang, David K; Eshun, Albert; Hogarh, Jonathan N; Bentum, John K; Adjei, Joseph K; Negishi, Junya; Nakamichi, Shihori; Habibullah-Al-Mamun, Md; Masunaga, Shigeki

    2017-02-01

    Perfluoroalkyl acids (PFAAs) are persistent environmental pollutants that have been detected in various media including human serum. Due to concerns regarding their bioaccumulation and possible negative health effects, an understanding of routes of human exposure is necessary. PFAAs are recalcitrant in many water treatment processes, making drinking water a potential source of human exposure. This study presents the first report on contamination from PFAAs in river and drinking water in Ghana. The targeted PFAAs were perfluoroalkyl carboxylic acids (PFCAs) with C 4-14 carbon chain and perfluoroalkane sulphonic acids (PFSAs) with C 6, 8, 10 . Five PFAA congeners - PFOA, PFOS, PFHxA, PFDA and PFPeA - were commonly detected in river and tap water. The mean concentrations of ∑PFAAs in the Kakum and Pra Rivers were 281 and 398ng/L, while tap water (supplied from the treatment of water from those rivers) contained concentrations of 197 and 200ng/L, respectively. PFOA and PFOS constituted about 99% of the ∑PFAAs. The risk quotient (RQ) attributed to drinking of tap water was estimated at 1.01 and 1.74 for PFOA and PFOS, respectively. For a country that has not produced these compounds, the RQs were unexpectedly high, raising concerns particularly about contamination from such emerging pollutants in local water sources. The study revealed limitations of local tap water treatment in getting rid of these emerging pollutants. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Tapping Alternatives: The Benefits of Managing Urban Water Demands.

    Science.gov (United States)

    Dziegielewski, Benedykt; Baumann, Duane D.

    1992-01-01

    Presents the California plan for water demand management. Water conservation techniques are used to balance demand with supply. Discusses the implementation process: (1) water-use and service area analysis; (2) water-use forecasts; (3) benefit-cost analysis; (4) and development of a long-term water management plan. (17 references) (MCO)

  2. Removal of waterborne pathogens from liver transplant unit water taps in prevention of healthcare-associated infections: a proposal for a cost-effective, proactive infection control strategy.

    Science.gov (United States)

    Zhou, Z Y; Hu, B J; Qin, L; Lin, Y E; Watanabe, H; Zhou, Q; Gao, X D

    2014-04-01

    Hospital water supplies often contain waterborne pathogens, which can become a reservoir for healthcare-associated infections (HAIs). We surveyed the extent of waterborne pathogen contamination in the water supply of a Liver Transplant Unit. The efficacy of point-of-use (POU) water filters was evaluated by comparative analysis in routine clinical use. Our baseline environmental surveillance showed that Legionella spp. (28%, 38/136), Pseudomonas aeruginosa (8%, 11/136), Mycobacterium spp. (87%, 118/136) and filamentous fungi (50%, 68/136) were isolated from the tap water of the Liver Transplant Unit. 28.9% of Legionella spp.-positive water samples (n = 38) showed high-level Legionella contamination (≥10(3) CFU/L). After installation of the POU water filter, none of these pathogens were found in the POU filtered water samples. Furthermore, colonizations/infections with Gram-negative bacteria determined from patient specimens were reduced by 47% during this period, even if only 27% (3/11) of the distal sites were installed with POU water filters. In conclusion, the presence of waterborne pathogens was common in the water supply of our Liver Transplant Unit. POU water filters effectively eradicated these pathogens from the water supply. Concomitantly, healthcare-associated colonization/infections declined after the POU filters were installed, indicating their potential benefit in reducing waterborne HAIs. © 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.

  3. Sociodemographic characteristics and beverage intake of children who drink tap water.

    Science.gov (United States)

    Patel, Anisha I; Shapiro, Daniel J; Wang, Y Claire; Cabana, Michael D

    2013-07-01

    Tap water provides a calorie-free, no-cost, environmentally friendly beverage option, yet only some youth drink it. To examine sociodemographic characteristics, weight status, and beverage intake of those aged 1-19 years who drink tap water. National Health and Nutrition Examination Survey data (2005-2010) were used to examine factors associated with tap water consumption. A comparison was made of beverage intake among tap water consumers and nonconsumers, by age, race/ethnicity, and income. Tap water consumption was more prevalent among school-aged children (OR=1.85, 95% CI=1.47, 2.33, for those aged 6-11 years; OR=1.85, 95% CI=1.32, 2.59, for those aged 12-19 years) as compared to those aged 1-2 years. Tap water intake was less prevalent among girls/women (OR=0.76, 95% CI=0.64, 0.89); Mexican Americans (OR=0.32, 95% CI=0.23, 0.45); non-Hispanic blacks (OR=0.48, 95% CI=0.34, 0.67); and others (OR=0.50, 95% CI=0.36, 0.68) as compared to whites; Spanish speakers (OR=0.72, 95% CI=0.55, 0.95); and among referents with a lower than Grade-9 education (OR=0.52, 95% CI=0.31, 0.88); Grade 9-11 education (OR=0.50, 95% CI=0.32, 0.77); and high school/General Educational Development test completion (OR=0.50, 95% CI=0.33, 0.76), as compared to college graduates. Tap water consumers drank more fluid (52.5 vs 48.0 ounces, ptap water, and this finding is more pronounced among minorities. Sociodemographic disparities in tap water consumption may contribute to disparities in health outcomes. Improvements in drinking water infrastructure and culturally relevant promotion may help to address these issues. Published by Elsevier Inc. on behalf of American Journal of Preventive Medicine

  4. Assessment of drinking water quality at the tap using fluorescence spectroscopy

    DEFF Research Database (Denmark)

    Heibati, Masoumeh; Stedmon, Colin A; Stenroth, Karolina

    2017-01-01

    Treated drinking water may become contaminated while travelling in the distribution system on the way to consumers. Elevated dissolved organic matter (DOM) at the tap relative to the water leaving the treatment plant is a potential indicator of contamination, and can be measured sensitively...

  5. Successful treatment of dyshidrotic hand eczema using tap water iontophoresis with pulsed direct current.

    Science.gov (United States)

    Odia, S; Vocks, E; Rakoski, J; Ring, J

    1996-11-01

    The efficacy of tap water iontophoresis in treating palmoplantar hyperhidrosis has been sufficiently documented and has led to its extensive use in clinical practice. In order to test the efficacy of this treatment modality in cases of dyshidrotic hand eczema, 20 patients were treated with tap water iontophoresis in addition to two-sided steroid-free topical therapy in a randomized half-side-study. A special score for dyshidrotic eczema including objective and subjective criteria was developed to document the success of the therapy. Only those sides treated with tap water iontophoresis showed significant improvement. This significant effect of iontophoresis indicates the efficacy of this treatment in cases of dyshidrotic hand eczema.

  6. Boiling of simulated tap water: effect on polar brominated disinfection byproducts, halogen speciation, and cytotoxicity.

    Science.gov (United States)

    Pan, Yang; Zhang, Xiangru; Wagner, Elizabeth D; Osiol, Jennifer; Plewa, Michael J

    2014-01-01

    Tap water typically contains numerous halogenated disinfection byproducts (DBPs) as a result of disinfection, especially of chlorination. Among halogenated DBPs, brominated ones are generally significantly more toxic than their chlorinated analogues. In this study, with the aid of ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry by setting precursor ion scans of m/z 79/81, whole spectra of polar brominated DBPs in simulated tap water samples without and with boiling were revealed. Most polar brominated DBPs were thermally unstable and their levels were substantially reduced after boiling via decarboxylation or hydrolysis; the levels of a few aromatic brominated DBPs increased after boiling through decarboxylation of their precursors. A novel adsorption unit for volatile total organic halogen was designed, which enabled the evaluation of halogen speciation and mass balances in the simulated tap water samples during boiling. After boiling for 5 min, the overall level of brominated DBPs was reduced by 62.8%, of which 39.8% was volatilized and 23.0% was converted to bromide; the overall level of chlorinated DBPs was reduced by 61.1%, of which 44.4% was volatilized and 16.7% was converted to chloride; the overall level of halogenated DBPs was reduced by 62.3%. The simulated tap water sample without boiling was cytotoxic in a chronic (72 h) exposure to mammalian cells; this cytotoxicity was reduced by 76.9% after boiling for 5 min. The reduction in cytotoxicity corresponded with the reduction in overall halogenated DBPs. Thus, boiling of tap water can be regarded as a "detoxification" process and may reduce human exposure to halogenated DBPs through tap water ingestion.

  7. Tap water versus sterile saline solution in the colonisation of skin wounds.

    Science.gov (United States)

    Resende, Margarida Mc; Rocha, Cleber A; Corrêa, Nely Fm; Veiga, Renato Rg; Passos, Sandro Jf; Novo, Neil F; Juliano, Yara; Damasceno, Carlos Av

    2016-08-01

    Irrigating wounds with tap water does not increase colonisation, but controlled studies are required for further evidence. Microbial colonisation was assessed in skin wounds, before and after irrigation with tap water, and was compared with irrigation using 0·9% sodium chloride sterile solution. The study included 120 subjects with chronic, traumatic, vascular, pressure or neuropathic wounds. A total of 60 wounds were randomly assigned to be irrigated with tap water (tap water group) and another 60 to be irrigated with 0·9% sodium chloride sterile solution (saline group), at a pressure of 0·46-0·54 PSI. Samples were collected from the centre of each wound using Levine's technique, before and after irrigation, and cultivated in thioglycollate, hypertonic mannitol agar, eosin methylene blue (EMB) agar, blood agar and Sabouraud agar at 37°C for 72 hours. There was concordance (kappa test) and discordance (McNemar test) regarding the count of positive and/or negative samples before and after irrigation in each group. The proportion of reduction of positive samples was similar for both groups in all cultures. Colony-forming unit count before and after irrigation was similar in both groups and in all cultures, except for the culture in hypertonic mannitol agar from the tap water group, for which the count was lower after irrigation (Wilcoxon z = 2·05, P = 0·041). It is concluded that skin wound irrigation with tap water leads to further reduction of Gram-positive bacteria compared with 0·9% sodium chloride sterile solution, with no difference in colonisation of haemolytic bacteria, Gram-negative bacteria and fungi. © 2015 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  8. Bottled or tap? Testing perceptions about water in Lebanon and ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2016-06-09

    Jun 9, 2016 ... Researchers compared water quality available in two informal settlements in Lebanon and Jordan. Tests were conducted to compare water supplied by the municipality and bottled water. The results: tests showed that their quality is similar, although the brand of the bottled water and how it is stored affected ...

  9. Microprocessor controlled anodic stripping voltameter for trace metals analysis in tap water

    Energy Technology Data Exchange (ETDEWEB)

    Clem, R.G.; Park, F.W.; Kirsten, F.A.; Phillips, S.L.; Binnall, E.P.

    1981-04-01

    The construction and use of a portable, microprocessor controlled anodic stripping voltameter for on-site simultaneous metal analysis of copper, lead and cadmium in tap water is discussed. The instrumental system is comprised of a programmable controller which permits keying in analytical parameters such as sparge time and plating time; a rotating cell for efficient oxygen removal and amalgam formation; and, a magnetic tape which can be used for data storage. Analysis time can be as short as 10 to 15 minutes. The stripping analysis is based on a pre-measurement step during which the metals from a water sample are concentrated into a thin mercury film by deposition from an acetate solution of pH 4.5. The concentrated metals are then electrochemically dissolved from the film by application of a linearly increasing anodic potential. Typical peak-shaped curves are obtained. The heights of these curves are related to the concentration of metals in the water by calibration data. Results of tap water analysis showed 3 +- 1 ..mu..g/L lead, 22 +- 0.3 ..mu..g/L copper, and less than 0.2 ..mu..g/L cadmium for a Berkeley, California tap water, and 1 to 1000 ..mu..g/L Cu, 1 to 2 ..mu..g/L Pb for ten samples of Seattle, Washington tap water. Recommendations are given for a next generation instrument system.

  10. Cardiovascular and metabolic responses to tap water ingestion in young humans: does the water temperature matter?

    Science.gov (United States)

    Girona, M; Grasser, E K; Dulloo, A G; Montani, J P

    2014-06-01

    Drinking water induces short-term cardiovascular and metabolic changes. These effects are considered to be triggered by gastric distension and osmotic factors, but little is known about the influence of water temperature. We determined, in a randomized crossover study, the acute cardiovascular and metabolic responses to 500 mL of tap water at 3 °C (cold), 22 °C (room) and 37 °C (body) in 12 young humans to ascertain an effect of water temperature. We measured continuous beat-to-beat haemodynamics, skin blood flux with laser-Doppler flowmetry and resting energy expenditure by indirect calorimetry starting with a 30-min baseline followed by a 4-min drink period and a subsequent 90-min post-drink observation. Ingestion of cold- and room-tempered water led to decreased heart rate (P body-tempered water. Drinking cold- and room-, but not body-tempered water, led to increased high frequency power of heart rate variability (P water increased energy expenditure over 90 min by 2.9% (P water to intra-abdominal temperature levels. Overall, ingestion of cold- and room-, but not body-tempered water reduced the workload to the heart through a reduction in heart rate and double product which could be mediated by an augmented cardiac vagal tone. © 2014 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  11. Assessment of the radiological quality of tap waters 2008-2009

    International Nuclear Information System (INIS)

    Caamano, Delphine; Tracol, Raphael; Guillotin, Laetitia; Jedor, Beatrice; Davezac, Henri; Loyen, Jeanne

    2011-06-01

    After a recall of the context (radioactivity, origin of natural radioactivity in waters, exposure of population to natural radioactivity and health impact, indicators of water radiological quality, presence of uranium in water), this document reports a study which is based on the health control of water radiological quality by regional health agencies, on the analysis of natural and artificial radionuclides, on a survey on tap water radiological quality performed in 2009 by regional health agencies, and on an inventory of results related to the presence of radon in water performed by the IRSN and these agencies. The obtained results are presented and discussed in terms of factors impacting the result representativeness, of generalisation of the implementation of a health control, of tap water radiological quality. It is outlined that the uranium-related chemical risk is higher than the radiological risk

  12. Tap water isotopes reveal the San Francisco Bay Area's plumbing and responses to a major drought

    Science.gov (United States)

    Tipple, B. J.; Jameel, M. Y.; Chau, T. H.; Mancuso, C. J.; Bowen, G. J.; Dufour, A.; Chesson, L. A.; Ehleringer, J. R.

    2016-12-01

    Water availability and sustainability in the Western United States is a major flashpoint among expanding communities, growing industries, and productive agricultural lands. This issue came to a head in 2015 in the State of California, when the State mandated a 25% reduction in urban water use following a multi-year drought that significantly depleted water resources. The demands for and challenges in supplying water are only expected to intensify as climate perturbations, such as the 2012-2015 California Drought, become more common. As a consequence, there is an increased need to understand linkages between population centers, water transport and usage, and the impacts of climate change on water resources and infrastructure. To better understand these relationships within a megalopolis in the Western United States, we collected and analyzed 723 tap waters from the San Francisco Bay Area during seven collection campaigns across 21 months during 2013-2015. San Francisco Bay Area was selected as it has well-known water management strategies and its water resources were dramatically affected by the 2012-2105 drought. Consistent with known water management strategies and previous reports of tap water isotope values, we found large spatiotemporal variations in the δ2H and δ18O values of tap waters, indicative of complex water transport systems and municipality-scale management decisions. We observed δ2H and δ18O values of tap water consistent with waters originating from snowmelt from the Sierra Nevada Mountains, local precipitation, ground water, and partially evaporated reservoir sources. A cluster analysis of measured tap water data grouped waters from 43 static sampling sites that were associated with specific water utility providers within the San Francisco Bay Area and known management practices. Water management responses to the drought, such as source switching, bringing in new sources, and conservation, could be observed within the isotope data from each of

  13. Rapidly growing nontuberculous mycobacteria cultured from home tap and shower water.

    Science.gov (United States)

    van Ingen, Jakko; Blaak, Hetty; de Beer, Jessica; de Roda Husman, Ana Maria; van Soolingen, Dick

    2010-09-01

    Tap and shower water at two locations in the Netherlands was examined for the presence of rapidly growing nontuberculous mycobacteria. Cultures yielded Mycobacterium peregrinum, M. salmoniphilum, M. llatzerense, M. septicum, and three potentially novel species, a distribution different from that in clinical samples.

  14. TIME TO PREGNANCY IN RELATION TO TOTAL TRIHALOMETHANE LEVELS IN TAP WATER

    Science.gov (United States)

    Time to pregnancy in relation to total trihalomethane levels in tap waterShanna H. Swan, Cuirong Ren, Gayle C. Windham, Laura Fenster, Kirsten Waller. (University of Missouri and California Department of Health Services). We have previously reported increased risks o...

  15. Tap water scalds among seniors and the elderly: socio-economics and implications for prevention.

    Science.gov (United States)

    Alden, Nicole E; Bessey, Palmer Q; Rabbitts, Angela; Hyden, Philip J; Yurt, Roger W

    2007-08-01

    Tap water scalds among those >or=60 years old are often attributed to physical impairments with aging. This study assesses socio-economics associated with tap water scalds among seniors and the elderly. Charts of patients admitted to an urban Burn Center between 7/00 and 6/04 for treatment of tap water scalds were reviewed. Demographics, injury details, co-morbidities, surgical interventions/critical care requirements, length of stay (LOS), disposition and related economics were reviewed. During the study period, 68 patients >or=60 years were hospitalized for treatment of these scalds. Mean age and burn size were 78+/-1 years and 7+/-0.9% TBSA. Over 98% of patients were admitted with pre-existing co-morbidities; 60% required ICU care for 40+/-5 days; 22% required mechanical ventilation and 71% required surgery. LOS was 34+/-4 days. Most patients received government assistance income. Pre-injury, 32% resided alone. Post-injury, 10% of patients returned home alone; mortality was 22%. Per patient hospital costs approximated $113,000. These findings report that tap water scalds result in significant morbidity, mortality and health care costs for local seniors and the elderly. Socio-economic factors play a significant role in these injuries and must be assessed when planning prevention efforts.

  16. Abdominal tap

    Science.gov (United States)

    Peritoneal tap; Paracentesis; Ascites - abdominal tap; Cirrhosis - abdominal tap; Malignant ascites - abdominal tap ... You then receive a local numbing medicine. The tap needle is inserted 1 to 2 inches (2. ...

  17. Water partnerships: IAEA regional projects for Africa TAP expertise

    International Nuclear Information System (INIS)

    Boussaha, A.; Kastens, R.F.

    2000-01-01

    Issues of water scarcity are on the top of governmental agendas. The efforts of the IAEA's African Member States to address these issues rely upon increasingly complex requirements for analytical tools, technologies and institutional capacities. National programmes in water resources management are receiving growing attention and a large number of bilateral and multilateral development partners are actively involved in providing technical and financial support. Applications of nuclear techniques in the field of hydrology constitute important, and sometimes unique tools for obtaining critical information needed for water resources management. In most cases, isotope hydrology methodologies provide a qualitative definition or solution of the hydrological problem while in certain circumstances, quantification of hydrological parameters are enabled only by the application of these methodologies. Such information is essential for determining the long-term productive capacity of an aquifer, protecting vulnerable recharge areas from pollution, or limiting saltwater intrusion. Isotopes also provide useful data for constraining and validating groundwater models used for water management

  18. Tap Water Hydraulic Control Systems - Design and Industrial Applications. Chapter 7 in Advances in Hydraulic Control Systems

    DEFF Research Database (Denmark)

    Conrad, Finn

    Deals with development and design of modern tap water hydraulic components and systems, in particalar the Danfoss Nessie-family of components and systems working with pure tap water without any kind of additives. Typical industrial applications are presented and the perspectives of new industrial...

  19. Radiation hazards and lifetime risk assessment of tap water using liquid scintillation counting and high-resolution gamma spectrometry.

    Science.gov (United States)

    Al-Shboul, K F; Alali, A E; Batayneh, I M; Al-Khodire, H Y

    2017-11-01

    In this work, two complementary techniques, viz. liquid scintillation counting and high-resolution gamma spectrometry are utilized to analyze radionuclides concentrations in tap water of Irbid governorate, Jordan, and study their correlation. Gross alpha and gross beta concentrations, in the tap water samples collected from the nine districts of Irbid governorate, ranged from tap water samples, shows that the activity concentrations of 226 Ra, 232 Th, and 40 K ranged between tap water in drilled wells leads to higher levels of radioactivity concentrations beyond the international permissible limits. Furthermore, the average lifetime risk and annual effective dose received by age-grouped inhabitants due to direct and indirect tap water consumption are evaluated, where most of the received dose is attributed to 226 Ra. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Contribution of tap water to chlorate and perchlorate intake: a market basket study.

    Science.gov (United States)

    Asami, Mari; Yoshida, Nobue; Kosaka, Koji; Ohno, Koichi; Matsui, Yoshihiko

    2013-10-01

    The contributions of water to total levels of chlorate and perchlorate intake were determined using food and water samples from a market basket study from 10 locations in Japan between 2008 and 2009. Foods were categorized into 13 groups and analyzed along with tap water. The average total chlorate intake was 333 (min. 193-max. 486) μg/day for samples cooked with tap water. The contribution of tap water to total chlorate intake was as high as 47%-58%, although total chlorate intake was less than 32% of the tolerable daily intake, 1500 μg/day for body weight of 50 kg. For perchlorate, daily intake from water was 0.7 (0.1-4.4) μg/day, which is not high compared to the average total intake of 14 (2.5-84) μg/day, while the reference dose (RfD) is 35 μg/day and the provisional maximum tolerable daily intake (PMTDI) is 500 μg/day for body weight of 50 kg. The highest intake of perchlorate was 84 μg/day, where concentrations in foods were high, but not in water. The contribution of water to total perchlorate intake ranged from 0.5% to 22%, while the ratio of highest daily intake to RfD was 240% and that to PMTDI was 17%. Eight baby formulas were also tested--total chlorate and perchlorate intakes were 147 (42-332) μg/day and 1.11 (0.05-4.5) μg/day, respectively, for an ingestion volume of 1 L/day if prepared with tap water. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Bacterial Pathogens Associated with Tap and Well Waters in Lagos ...

    African Journals Online (AJOL)

    Results: Our finding revealed that all the well waters from the locations under study were contaminated with one or more of the following bacterial pathogens Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Enterobacter aerogenes, Shigella dysenteriae, Proteus vulgaris and Pseudomonas aeruginosa, with E coli ...

  2. Spectrophotometric determination of iron (III) in tap water using 8 ...

    African Journals Online (AJOL)

    ajl yemi

    2011-11-14

    Nov 14, 2011 ... Atomic absorption spectro- metry and inductively coupled with plasma spectrometry have also been applied for the determination of iron in water and other cations (Abollino et al., 1995). Iron has been separated by capillary isotachophoresis as an. EDTA complex for the simultaneous determination of.

  3. Availability of clean tap water and medical services prevents the incidence of typhoid Fever.

    Science.gov (United States)

    Lee, Deog-Yong; Lee, Esther; Park, Hyemin; Kim, Seonghan

    2013-04-01

    In this study, the factors that induced a decrease in the incidence of typhoid fever were analyzed. Based on the study results, we propose a quantitative and concrete solution to reduce the incidence of typhoid fever. We analyzed the incidence and fatality rate of typhoid fever in Korea. Tap water service rate and the number of pharmacies, which affect the incidence rate of typhoid fever, were used as environmental factors. To prevent typhoid fever in the community, it is necessary to provide clean tap water service to 35.5% of the population, with an individual requiring 173 L of clean water daily. Appropriate access to clean water (51% service coverage, 307 L) helped the population to maintain individual hygiene and food safety practices, which brought about a decrease in the incidence of typhoid fever, and subsequently a decrease in fatality rate, which was achieved twice. During the 8-year study period, the fatality rate decreased to 1% when the population has access to proper medical service. The fatality rate was primarily affected by the availability of medical services as well as by the incidence of typhoid fever. However, an analysis of the study results showed that the incidence of typhoid fever was affected only by the availability of clean water through the tap water system.

  4. Pharmaceuticals in tap water: human health risk assessment and proposed monitoring framework in China.

    Science.gov (United States)

    Leung, Ho Wing; Jin, Ling; Wei, Si; Tsui, Mirabelle Mei Po; Zhou, Bingsheng; Jiao, Liping; Cheung, Pak Chuen; Chun, Yiu Kan; Murphy, Margaret Burkhardt; Lam, Paul Kwan Sing

    2013-07-01

    Pharmaceuticals are known to contaminate tap water worldwide, but the relevant human health risks have not been assessed in China. We monitored 32 pharmaceuticals in Chinese tap water and evaluated the life-long human health risks of exposure in order to provide information for future prioritization and risk management. We analyzed samples (n = 113) from 13 cities and compared detected concentrations with existing or newly-derived safety levels for assessing risk quotients (RQs) at different life stages, excluding the prenatal stage. We detected 17 pharmaceuticals in 89% of samples, with most detectable concentrations (92%) at risk levels, but 4 (i.e., dimetridazole, thiamphenicol, sulfamethazine, and clarithromycin) were found to have at least one life-stage RQ ≥ 0.01, especially for the infant and child life stages, and should be considered of high priority for management. We propose an indicator-based monitoring framework for providing information for source identification, water treatment effectiveness, and water safety management in China. Chinese tap water is an additional route of human exposure to pharmaceuticals, particularly for dimetridazole, although the risk to human health is low based on current toxicity data. Pharmaceutical detection and application of the proposed monitoring framework can be used for water source protection and risk management in China and elsewhere.

  5. Perceptions of Tap Water and School Water Fountains among Youth and Association with Intake of Plain Water and Sugar-Sweetened Beverages

    Science.gov (United States)

    Onufrak, Stephen J; Park, Sohyun; Sharkey, Joseph R; Merlo, Caitlin; Dean, Wesley R.; Sherry, Bettylou

    2015-01-01

    BACKGROUND Little is known regarding youth perceptions of tap water and school water fountains and how these relate to water and sugar-sweetened beverage (SSB) intake. METHODS We used national 2010 YouthStyles data to assess perceptions of tap water and school water fountains and associations with water and SSB intake. RESULTS Nearly 1 in 5 participants disagreed their tap water was safe and nearly 2 in 5 disagreed school water fountains were clean and safe. Perceived tap water risk was more prevalent among non-Hispanic (NH) blacks (26.4%) and Hispanics (28.3%) compared to NH whites (14.7%, p tap water risk was not associated with SSB intake (odds ratio (OR) = 1.0, 95% CI: 0.6, 1.5) or water intake (OR = 1.4, 95% CI: 0.9, 2.1). Negative water fountain perceptions were associated with SSB intake only among Hispanics (race/ethnicity interaction p tap water and water fountains among youth are common and should be considered in efforts to provide water in schools. PMID:24443781

  6. The relationship of perceptions of tap water safety with intake of sugar-sweetened beverages and plain water among US adults.

    Science.gov (United States)

    Onufrak, Stephen J; Park, Sohyun; Sharkey, Joseph R; Sherry, Bettylou

    2014-01-01

    Research is limited on whether mistrust of tap water discourages plain water intake and leads to a greater intake of sugar-sweetened beverages (SSB). The objective of the present study was to examine demographic differences in perceptions of tap water safety and determine if these perceptions are associated with intake of SSB and plain water. The study examined perceptions of tap water safety and their cross-sectional association with intake of SSB and plain water. Racial/ethnic differences in the associations of tap water perceptions with SSB and plain water intake were also examined. Nationally weighted data from the 2010 HealthStyles Survey (n 4184). US adults aged ≥18 years. Overall, 13·0 % of participants disagreed that their local tap water was safe to drink and 26·4 % of participants agreed that bottled water was safer than tap water. Both mistrust of tap water safety and favouring bottled water differed by region, age, race/ethnicity, income and education. The associations of tap water mistrust with intake of SSB and plain water were modified by race/ethnicity (P tap water was safe to drink were more likely to report low intake of plain water. The odds of consuming ≥1 SSB/d among Hispanics who mistrusted their local tap water was twice that of Hispanics who did not (OR = 2·0; 95 % CI 1·2, 3·3). Public health efforts to promote healthy beverages should recognize the potential impact of tap water perceptions on water and SSB intake among minority populations.

  7. Detection of Escherichia coli, Salmonella species, and Vibrio cholerae in tap water and bottled drinking water in Isfahan, Iran.

    Science.gov (United States)

    Momtaz, Hassan; Dehkordi, Farhad Safarpoor; Rahimi, Ebrahim; Asgarifar, Amin

    2013-06-07

    The quality of drinking water has an important role in human infection and disease. This study was aimed at comparing polymerase chain reaction and culture in detecting Escherichia coli, Salmonella species and Vibrio cholera in tape water and bottled drinking water in various seasons in Isfahan province, Iran. A total of 448 water samples from tap water and bottled mineral water were taken over 6 months, from July 2010 to December 2010, and after filtration, samples were examined by culture and polymerase chain reaction methods for detection of Escherichia coli, Salmonella species, and Vibrio cholerae. The culture method showed that 34 (7.58%), 4 (0.89%) and 3 (0.66%) of all 448 water samples were positive for Escherichia coli, Salmonella species, and Vibrio cholera, respectively. The uidA gene from Escherichia coli, IpaB gene from Salmonella species, and epsM gene from Vibrio cholera were detected in 38 (26.38%), 5 (3.47%), and 3 (2.08%) of 144 tap-water samples, respectively. Escherichia coli was detected in 8 (2.63%) of 304 samples of bottled drinking water from 5 companies. The water of southern part of Isfahan and company 5 had the highest prevalence of bacteria. The Escherichia coli water contamination was significantly higher (P waters of southern part and tap waters of central part of Isfahan. This study showed that the polymerase chain reaction assays can be an extremely accurate, fast, safe, sensitive and specific approach to monitor drinking water quality from purification facilities and bottled water companies. Also, our study confirmed the presence of Escherichia coli, Salmonella species, and Vibrio cholerae as water-borne pathogens in tap water and bottled drinking water of Isfahan, Iran. The present study showed the important public health problem in Isfahan, Iran.

  8. Susceptibility of Legionella pneumophila to chlorine in tap water.

    Science.gov (United States)

    Kuchta, J M; States, S J; McNamara, A M; Wadowsky, R M; Yee, R B

    1983-11-01

    A study was conducted to compare the susceptibility of legionellae and coliforms to disinfection by chlorine. The chlorine residuals used were similar to concentrations that might be found in the distribution systems of large public potable water supplies. The effects of various chlorine concentrations, temperatures, and pH levels were considered. A number of different Legionella strains, both environmental and clinical, were tested. The results indicate that legionellae are much more resistant to chlorine than are coliform bacteria. At 21 degrees C, pH 7.6, and 0.1 mg of free chlorine residual per liter, a 99% kill of L. pneumophila was achieved within 40 min, compared with less than 1 min for Escherichia coli. The observed resistance is enhanced as conditions for disinfection become less optimal. The required contact time for the removal of L. pneumophilia was twice as long at 4 degrees C than it was at 21 degrees C. These data suggest that legionellae can survive low levels of chlorine for relatively long periods of time.

  9. Reduction of FENOby tap water and carbonated water mouthwashes: magnitude and time course.

    Science.gov (United States)

    Lassmann-Klee, Paul Guenther; Lindholm, Tuula; Metsälä, Markus; Halonen, Lauri; Sovijärvi, Anssi Raimo Antero; Piirilä, Päivi

    Fractional exhaled nitric oxide (F ENO ) assesses eosinophilic inflammation of the airways, but F ENO values are also influenced by oral nitric oxide (NO). The aim of this pilot study was to measure F ENO and compare the effect of two different mouthwashes on F ENO and analyse the duration of the effect. F ENO was measured in 12 randomized volunteers (healthy or asthmatic subjects) with a NIOX VERO® analyser at an expiratory flow rate of 50 mL/s. After a baseline measurement, a mouthwash was performed either with tap water or carbonated water and was measured during 20 min in 2 min intervals. The procedure was repeated with the other mouthwash. We found that both mouthwashes reduced F ENO immediately at the beginning compared to the baseline (p mouthwash effect lasted 12 min (p ranging from mouthwash reduced F ENO statistically significantly only for 2 min compared with the baseline. We conclude that a single carbonated water mouthwash can significantly reduce the oropharyngeal NO contribution during a 12 min time interval.

  10. Evaluation of Tap Water Based on Sensor Array and Conducting Nanostructured Polymers

    Directory of Open Access Journals (Sweden)

    Eduarda Carvalho

    2016-11-01

    Full Text Available A sensor system, adapted to evaluate tap water, was fabricated and tested. Interdigitated  gold-coated microelectrodes were covered with various conducting polymers, single or mixed, under several different conditions. Polymer films were laid down by a  self-assembly technique and their impedance was analyzed over a range of frequencies from 1Hz to 1MHz. Samples collected from different localities at São Paulo state (Brazil were used. The results of sensorial system analyzed by Principal Component Analysis had allowed completing discrimination of tap water samples. Good discrimination between the sensors was observed when there was obtained a PCA with different samples, obtaining the total variance (PC1 = 62.03%; PC2 = 37.97% of the observations. The sensorial system based in global selectivity using interdigitated electrode and nanostruturated conducting polymers allowed a statistical discrimination of sample waters of different locations. The future expectations are the upgrading of the system and implementation of a monitoring of tap water systems based nanostructured sensors.

  11. Defensive spending on tap water substitutes: the value of reducing perceived health risks.

    Science.gov (United States)

    Dupont, Diane P; Jahan, Nowshin

    2012-03-01

    We examine factors that explain consumer spending on tap water substitutes using information from a national survey undertaken with a representative set of Canadian respondents. We develop a model to predict the percentage of households that undertake such spending for the purpose of reducing perceived health risks from tap water consumption. Using results from the model we estimate the magnitude of defensive expenditures to be over half a billion dollars (2010 US$) per year for Canada, as a whole. This is equivalent to approximately $48 per household per year or about $19 per person per year. Residents of Ontario, the province in which an Escherichia coli incident took place in 2000, have the highest willingness-to-pay of approximately $60 per household per year.

  12. Haitian Tap-Taps

    Science.gov (United States)

    Sterling, Joan

    2011-01-01

    In the small island country of Haiti, colorful taxis transport the natives to the market. Although the taxis may be crowded with people, goods, and even livestock, it is considered a luxury to ride rather than go on foot. The children's picture book, "Tap-Tap," is a wonderful introduction to the culture of this land. The name…

  13. Exposure to arsenic in tap water and gestational diabetes: A French semi-ecological study.

    Science.gov (United States)

    Marie, Cécile; Léger, Stéphanie; Guttmann, Aline; Rivière, Olivier; Marchiset, Nathalie; Lémery, Didier; Vendittelli, Françoise; Sauvant-Rochat, Marie-Pierre

    2018-02-01

    The increase in the prevalence of gestational diabetes mellitus (GDM) and its consequences for mother and children prompts research on their risk factors including environmental factors. Studies on exposure to arsenic (As) in tap water and the risk of GDM have not provided conclusive evidence, particularly when levels of exposure were low (from 10 to 50µg As/L). The main objective of this study was to assess the association between exposure to As in tap water and the risk of GDM. A semi-ecological study was conducted from births recorded at the University Hospital of Clermont-Ferrand, France, in 2003, 2006 and 2010. Individual medical/obstetric data were available. As exposure was estimated from the concentrations of As measured during sanitary control of tap water supplied in the mothers' commune of residence (aggregate data). French guidelines for As in tap water were used to identify groups potentially exposed, designated "As +" (≥ 10µg As/L) and "As -" (< 10µg As/L). Multivariate logistic regression analysis was performed. 5053 women (5.7% with a GDM) were included. Overall, women in the As + group had a higher risk of GDM than those in the As - group (adjusted OR = 1.62; 95%CI: 1.01-2.53). Stratified analysis of pre-pregnancy body mass index (BMI) showed a positive association only for obese or overweight women (adjusted OR = 2.30; 95%CI: 1.13-4.50). This French semi-ecological study provides additional arguments for an association between As exposure and the risk of GDM in particular in a context of low exposure. Further studies are needed to assess a potential interaction between As exposure and body mass index. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Availability of Clean Tap Water and Medical Services Prevents the Incidence of Typhoid Fever

    OpenAIRE

    Lee, Deog-Yong; Lee, Esther; Park, HyeMin; Kim, SeongHan

    2013-01-01

    Objective: In this study, the factors that induced a decrease in the incidence of typhoid fever were analyzed. Based on the study results, we propose a quantitative and concrete solution to reduce the incidence of typhoid fever. Methods: We analyzed the incidence and fatality rate of typhoid fever in Korea. Tap water service rate and the number of pharmacies, which affect the incidence rate of typhoid fever, were used as environmental factors. Results: To prevent typhoid fever in the communit...

  15. Spatial and statistical methods for correlating the interaction between groundwater contamination and tap water exposure in karst regions

    Science.gov (United States)

    Padilla, I. Y.; Rivera, V. L.; Macchiavelli, R. E.; Torres Torres, N. I.

    2016-12-01

    Groundwater systems in karst regions are highly vulnerable to contamination and have an enormous capacity to store and rapidly convey pollutants to potential exposure zones over long periods of time. Contaminants in karst aquifers used for drinking water purposes can, therefore, enter distributions lines and the tap water point of use. This study applies spatial and statistical analytical methods to assess potential correlations between contaminants in a karst groundwater system in northern Puerto Rico and exposure in the tap water. It focuses on chlorinated volatile organic compounds (CVOC) and phthalates because of their ubiquitous presence in the environment and the potential public health impacts. The work integrates historical data collected from regulatory agencies and current field measurements involving groundwater and tap water sampling and analysis. Contaminant distributions and cluster analysis is performed with Geographic Information System technology. Correlations between detection frequencies and contaminants concentration in source groundwater and tap water point of use are assessed using Pearson's Chi Square and T-Test analysis. Although results indicate that correlations are contaminant-specific, detection frequencies are generally higher for total CVOC in groundwater than tap water samples, but greater for phthalates in tap water than groundwater samples. Spatial analysis shows widespread distribution of CVOC and phthalates in both groundwater and tap water, suggesting that contamination comes from multiple sources. Spatial correlation analysis indicates that association between tap water and groundwater contamination depends on the source and type of contaminants, spatial location, and time. Full description of the correlations may, however, need to take into consideration variable anthropogenic interventions.

  16. Evaluation of radon concentration in well and tap waters in Bursa (Turkey)

    International Nuclear Information System (INIS)

    Akar Tarim, U.; Gurler, O.; Akkaya, G.; Kilic, N.; Yalcin, S.; Kaynak, G.; Gundogdu, O.

    2012-01-01

    222 Rn measurements in water samples collected from 27 wells and 19 taps that were supplied from the investigated wells were conducted using the AlphaGUARD PQ 2000PRO radon gas analyser at sites across several geologic formations within the city of Bursa (Turkey). The measured radon concentrations ranged from 1.46 to 53.64 Bq l -1 for well water and from 0.91 to 12.58 Bq l -1 for tap water. Of the 27 sites sampled, only 7 had radon levels above the safe limit of 11.1 Bq l -1 recommended by the USEPA. In general, all determined concentrations were well below the 100 Bq l -1 revised reference level proposed by the European Union. These values of radon concentrations in water samples are compared with those reported from other countries. Doses resulting from the consumption of these waters were calculated. The minimum and the maximum annual mean effective doses due to 222 Rn intake through water consumption were 0.02 μSv a -1 and 1.11 μSv a -1 , respectively. (authors)

  17. Control of bacterial contamination of washbasin taps and output water using Ecasol: a one-year study.

    LENUS (Irish Health Repository)

    Boyle, M A

    2012-04-01

    Contaminated washbasin taps and output water are an important source of bacteria that may cause nosocomial infection. A five-week pretreatment study of hot and cold water from 15 washbasin taps at Dublin Dental Hospital showed consistently heavy contamination by aerobic heterotrophic bacteria: mean bacterial counts of 482.5 [standard deviation (SD) 293] colony-forming units (cfu)\\/mL and 5022 (SD 4322) cfu\\/mL, respectively.

  18. Comparative analysis of the quality of drinking tap water in some areas of the Murmansk region

    Directory of Open Access Journals (Sweden)

    Bеkreneva O. I.

    2017-06-01

    Full Text Available The present work describes the microbiological research of drinkin g tap water quality of some settlements in the Murmansk region. The samples of drinking tap water have been selected and the microbiological indicators of thermotolerant coliform bacteria, common coliform bacteria, and total microbial number have been determined; the compliance of these indicators with the requirements of sanitary norms and rules has been also established. Determination of total microbial number has been carried out by the deep method, and levels of total and thermotolerant coliform bacteria – by the membrane filtration method. It has been shown that the content of microorganisms in drinking water sources depends on the season of the year. The greatest number of microorganisms in water is observed in spring and autumn p eriods of the year and is caused by floodwater and precipitation of water into the water intake system. The greates t number of microorganisms in water samples has been recorded in the town of Sputnik. The repeated inconsistency o f water quality with the requirements of normative and technical documentation has been identified. The prev alence of acute intestinal diseases among the population and the influence of water quality on this i ndicator have been estimated. The high incidence of intestinal infections in the town of Pechenga has been revealed, a few more prosperous for this indicator are the towns of Zaozersk and Sputnik. Recommendations for improvi ng the quality of drinking water treatment have been transferred to the services of central water supply and distributed among the population. After the implementation of the recommendations, the repeated tests have been performed, and some improvement of water quality has been stated.

  19. Microbial contamination of contact lens storage cases and domestic tap water of contact lens wearers.

    Science.gov (United States)

    Üstüntürk, Miray; Zeybek, Zuhal

    2012-11-01

    Contact lenses have been widely used as an alternative to spectacles both in developed and developing countries. However, under certain circumstances, adverse responses can occur during contact lens wear and several microorganisms--including bacteria, fungi, and free living amoebae--can cause several eye infections in wearers. Extended wear of contact lenses is the major risk factor of eye infections such as microbial keratitis, besides contaminated contact lens storage case, contaminated lens care solutions, and inaccurate contact lens handling. In this study, we collected contact lens storage case and domestic tap water samples from 50 asymptomatic contact lens wearers. We determined that total aerobic mesophilic bacteria were isolated in 45 (90 %), Gram negative rod bacteria were isolated in 20 (40 %), Pseudomonas spp. were isolated in 2 (4 %) and fungi were isolated in 18 (36 %) out of 50 contact lens storage cases. Free living amoebae were not detected in investigated contact lens storage cases. At the same time, out of 50, total aerobic mesophilic bacteria were isolated in 34 (68 %), fungi were isolated in 15 (30 %) and free living amoebae were isolated in 15 (30 %) domestic tap water samples. No Gram-negative rod bacteria and Pseudomonas spp. were detected in investigated water samples. Two contact lens case samples and two tap water samples were excluded from the analysis for Pseudomonas spp. for technical reasons. According to our findings, inadequate contact lens maintenance during lens wear may result in the contamination of contact lens storage cases. This situation can lead to severe eye infections in contact lens wearers over time.

  20. Removal of Fe(II) from tap water by electrocoagulation technique

    International Nuclear Information System (INIS)

    Ghosh, D.; Solanki, H.; Purkait, M.K.

    2008-01-01

    Electrocoagulation (EC) is a promising electrochemical technique for water treatment. In this work electrocoagulation (with aluminum as electrodes) was studied for iron Fe(II) removal from aqueous medium. Different concentration of Fe(II) solution in tap water was considered for the experiment. During EC process, various amorphous aluminum hydroxides complexes with high sorption capacity were formed. The removal of Fe(II) was consisted of two principal steps; (a) oxidation of Fe(II) to Fe(III) and (b) subsequent removal of Fe(III) by the freshly formed aluminum hydroxides complexes by adsorption/surface complexation followed by precipitation. Experiments were carried out with different current densities ranging from 0.01 to 0.04 A/m 2 . It was observed that the removal of Fe(II) increases with current densities. Inter electrode distance was varied from 0.005 to 0.02 m and was found that least inter electrode distance is suitable in order to achieve higher Fe(II) removal. Other parameters such as conductivity, pH and salt concentration were kept constant as per tap water quality. Satisfactory iron removal of around 99.2% was obtained at the end of 35 min of operation from the initial concentration of 25 mg/L Fe(II). Iron concentration in the solution was determined using Atomic absorption spectrophotometer. By products obtained from the electrocoagulation bath were analyzed by SEM image and corresponding elemental analysis (EDAX). Cost estimation for the electrocoagulation was adopted and explained well. Up to 15 mg/L of initial Fe(II) concentration, the optimum total cost was 6.05 US$/m 3 . The EC process for removing Fe(II) from tap water is expected to be adaptable for household use

  1. Indoor Heating Drives Water Bacterial Growth and Community Metabolic Profile Changes in Building Tap Pipes during the Winter Season.

    Science.gov (United States)

    Zhang, Hai-Han; Chen, Sheng-Nan; Huang, Ting-Lin; Shang, Pan-Lu; Yang, Xiao; Ma, Wei-Xing

    2015-10-27

    The growth of the bacterial community harbored in indoor drinking water taps is regulated by external environmental factors, such as indoor temperature. However, the effect of indoor heating on bacterial regrowth associated with indoor drinking water taps is poorly understood. In the present work, flow cytometry and community-level sole-carbon-source utilization techniques were combined to explore the effects of indoor heating on water bacterial cell concentrations and community carbon metabolic profiles in building tap pipes during the winter season. The results showed that the temperature of water stagnated overnight ("before") in the indoor water pipes was 15-17 °C, and the water temperature decreased to 4-6 °C after flushing for 10 min ("flushed"). The highest bacterial cell number was observed in water stagnated overnight, and was 5-11 times higher than that of flushed water. Meanwhile, a significantly higher bacterial community metabolic activity (AWCD590nm) was also found in overnight stagnation water samples. The significant "flushed" and "taps" values indicated that the AWCD590nm, and bacterial cell number varied among the taps within the flushed group (p heating periods.

  2. PLASMA NA/K CHANGES AFTER GASTRIC LAVAGE WITH TAP WATER IN INGESTION POISONING PATIENTS

    Directory of Open Access Journals (Sweden)

    K MONTAZERI

    2002-06-01

    Full Text Available Introduction. Ingestion poisoning include 79% of all poisoning. Usually the first step in management of these patients is gastric lavage, which in most centers is done by tap water (exepct for children below 4 years old. Due to low Na and K of tap water and daily secretion of Na and K in stomach, one of the probable complications of this lavage is lasting the Na and K, and electrolyte imbalance in patients. Methods. This study was done on 100 poisoned patients undergone Gastric lavage. All of patients were more than 4 years old. Poisoning by toxin or drug contain sodium or potassium, cause to exclude patients from study. For all patients Na/K of plasma before and half hour after gastric lavage were measured. After gastric lavage, volume of lavage, Na/K of lavage liquid and Na/K of tap water were recorded. Results. The changes of plasma Na in all patients were from 7 mmol/lit increasing to 12 mmol/Lit decreasing, and for plasma K were from 1 mmol/lit increasing to 1.2 mmol/lit decreasing. Means changes of Na was 2.74 mmol/lit decreasing and mean change of K was 0.33 mmol/Lit. Decreasing in plasma electrolytes in patients with high volume of gastric lavage was predominant but this relation between. volume of lavage and changing of plasma electrolytes was not considerable. Also total Na and K excretion" in all volumes of lavage was nearly equal. Discussion. In patients without underlying disesae, plasma Na/K changes during gastric lavage is not considerable but in patients with underlying disease or old patients can lead to electrolytes disturbance and to be recommended in these patients plasma elcectrolytes to be measured.

  3. Treatment of primary hyperhidrosis with tap water iontophoresis in paediatric patients: a retrospective analysis.

    Science.gov (United States)

    Dogruk Kacar, Seval; Ozuguz, Pinar; Eroglu, Selma; Polat, Serap; Karaca, Semsettin

    2014-12-01

    Primary hyperhidrosis is an under-recognized condition in children and adolescents. Iontophoresis is the second line of treatment for palmoplantar hyperhidrosis following topical treatment. The studies evaluating the efficacy of iontophoresis in children are limited. We aimed to investigate the efficacy and reliability of tap water iontophoresis in children with primary hyperhidrosis. Twenty-one patients aged under 18 years, who received iontophoresis for primary palmoplantar hyperhidrosis, were included in the study. In our clinic, tap water iontophoresis was administered at regular intervals, starting with five times per week and decreased to once a week on fifth week. Then maintenance sessions once a week for 6 weeks are recommended. The presence of excessive sweating was scored by visual analogue scale (VAS): "0" as continuation of excessive sweating and "10" as the absence of excessive sweating. The demographic and clinical data were collected from files. Also, patients fulfilled a questionnaire for efficacy on follow-up visit. Nineteen patients completed the whole 21 sessions. The mean VAS score was 5.89 ± 1.49 at the end of the 15th session and 6.36 ± 2.06 at the end of the treatment. Side effects were well tolerated. Only seven patients were still free of excessive sweating on third months after treatment. The mean satisfaction score was 4.95 ± 2.38, as measured by VAS where 0 indicated dissatisfaction and 10 indicated high satisfaction. Tap water iontophoresis is an effective method of treatment for primary palmoplantar and axillary hyperhidrosis in paediatric patients. But there are still unanswered questions about the mechanism of action, ideal session intervals and protocols for maximum efficacy.

  4. Assessment of the Extraction Methods for Monitoring Phthalate Emerging Contaminants in Groundwater and Tap Water

    Science.gov (United States)

    Cotto, I.; Padilla, I. Y.; De Jesús, N. H.; Torres, P. M.

    2015-12-01

    Trace organic contaminants such as phthalates, among other chemicals of emerging concerns, have not historically been considered as pollutants but are being detected in water, posing a potential risk to public health and the environment. One of the most common phthalates of particular concern is di-(2-ethylhexyl) phthalate (DEHP), a plasticizer normally found in plastics and consumer products, including: cosmetics, pharmaceuticals, medical devices, food packages, water bottles, and wiring cables. DEHP has been associated with preterm birth, a major cause of neonatal mortality and health complications. This study aims at monitoring the presence and concentration of DEHP and other phthalates in groundwater and tap water systems in Puerto Rico, which has one of the highest rates of preterm birth in the U.S. The Environmental Protection Agency (EPA) suggests a liquid-liquid extraction method that uses methylene chloride as the preferred organic solvent for the extractions. This work presents modified EPA methods that reduce the volume of sample and solvent used, lower the time of analysis, increase productivity, and decrease hazards and waste. Distribution coefficient of DEHP between methylene chloride and water are estimated and related to sample extraction efficiency. Research results indicate that DEHP is in fact distributed between water and methylene chloride with a distribution coefficient average value of 1.24. The study concludes that the sample and solvent volumes have influence on the efficiency but have not an effect on the distribution coefficient. The tests show higher extraction efficiencies for lower DEHP concentrations and higher extraction volumes. Results from the water analysis show presence of DEHP in 55% of groundwater and 44% of tap water samples, indicating a potential exposure through water.

  5. Water heater temperature set point and water use patterns influence Legionella pneumophila and associated microorganisms at the tap.

    Science.gov (United States)

    Rhoads, William J; Ji, Pan; Pruden, Amy; Edwards, Marc A

    2015-12-01

    Lowering water heater temperature set points and using less drinking water are common approaches to conserving water and energy; yet, there are discrepancies in past literature regarding the effects of water heater temperature and water use patterns on the occurrence of opportunistic pathogens, in particular Legionella pneumophila. Our objective was to conduct a controlled, replicated pilot-scale investigation to address this knowledge gap using continuously recirculating water heaters to examine five water heater set points (39-58 °C) under three water use conditions. We hypothesized that L. pneumophila levels at the tap depend on the collective influence of water heater temperature, flow frequency, and the resident plumbing ecology. We confirmed temperature setting to be a critical factor in suppressing L. pneumophila growth both in continuously recirculating hot water lines and at distal taps. For example, at 51 °C, planktonic L. pneumophila in recirculating lines was reduced by a factor of 28.7 compared to 39 °C and was prevented from re-colonizing biofilm. However, L. pneumophila still persisted up to 58 °C, with evidence that it was growing under the conditions of this study. Further, exposure to 51 °C water in a low-use tap appeared to optimally select for L. pneumophila (e.g., 125 times greater numbers than in high-use taps). We subsequently explored relationships among L. pneumophila and other ecologically relevant microbes, noting that elevated temperature did not have a general disinfecting effect in terms of total bacterial numbers. We documented the relationship between L. pneumophila and Legionella spp., and noted several instances of correlations with Vermamoeba vermiformis, and generally found that there is a dynamic relationship with this amoeba host over the range of temperatures and water use frequencies examined. Our study provides a new window of understanding into the microbial ecology of potable hot water systems and helps to resolve

  6. A study on the prevalence of Aeromonas spp. and its enterotoxin genes in samples of well water, tap water, and bottled water

    Directory of Open Access Journals (Sweden)

    Hareesh Didugu

    2015-10-01

    Full Text Available Aim: The aim of this work was to study the prevalence of Aeromonas spp. and its enterotoxin genes in various water sources. Materials and Methods: 125 samples (50 from well water, 50 from tap water, and 25 from bottled water were collected from various sources in and around Greater Hyderabad Municipal Corporation and examined for the presence of aeromonads by both cultural and polymerase chain reaction (PCR assay. Alkaline peptone water with ampicillin was used as enrichment. Aeromonas isolation medium and ampicillin dextrin agar were used as selective media. The boiling and snap chilling method was used for DNA extraction. Primers targeted against 16S rRNA, aer, and ast were used to identify aeromonads and its enterotoxins. Results: 48%, 18%, and 12% of well water, tap water, and bottled water samples were found positive by cultural assay with an overall prevalence of 28.8%. Aeromonads were detected in 32 % (52% in well water, 20% in tap water, and 16% in bottled water of samples by PCR assay. Aerolysin (aer gene was noticed in 34.6%, 20%, and 0% of well water, tap water, and bottled water samples, respectively, with an overall prevalence of 27.5%. Thermostable cytotonic enterotoxin (ast was observed in 37.5% (42.3% in well water, 30% in tap water, and 25% in bottled mineral water of samples. Conclusions: Presence of aeromonads and its toxin genes in various sources of water is of public health concern and emphasizes the need for necessary preventive measures to tackle the problem.

  7. The occurrence of Aeromonas spp. in the bottled mineral water, well water and tap water from the municipal supplies

    Directory of Open Access Journals (Sweden)

    Denise de Oliveira Scoaris

    2008-10-01

    Full Text Available The aim of this work was to study the occurrence of Aeromonas sp in the bottled mineral water, well water and tap water from the municipal supplies. Positive samples were found for Aeromonas spp. 12.7% from the mineral water, 8.3% from the artesian water and 6.5% from the tap water. The recovery of Aeromonas spp. was significantly higher in the bottled mineral and artesian water than in the tap water from municipal supplies. The occurrence of the Aeromonas spp. did not correlate significantly with the contamination indicator bacteria (i.e. total coliforms in the artesian water samples. However, a significant correlation was found between Aeromonas spp. and total coliforms in the both mineral water and tap water samples. The presence or absence of a correlation between the indicator bacteria and Aeromonas could reflect the occasional appearance of the pathogen in the drinking water and the different rates of survival and recovery of these agents compared with those fecal indicators. The finding that 41.6, 14.8 and 9.0 % of the artesian water, bottled mineral water and tap water, respectively, sampled in the current study failed to meet the Brazilian standard for total coliforms in the drinking water should therefore be of concern.A porcentagem de amostras positivas para Aeromonas foi de 12.7% para água mineral, 8.3% para água de poço artesiano e 6.5% para água do sistema público de abastecimento. O isolamento de Aeromonas spp. foi significativamente maior em água mineral e água de poço artesiano do que em água do sistema público. A ocorrência de Aeromonas spp. não teve correlação significativa com os indicadores de contaminação tradicionalmente utilizados (coliformes totais em amostras de água de poço artesiano. No entanto, esta correlação foi positiva e significativa em água mineral e água do sistema público. A presença ou ausência de correlação entre bactérias indicadoras e a presença de Aeromonas pode refletir o

  8. Spatial, seasonal, and source variability in the stable oxygen and hydrogen isotopic composition of tap waters throughout the USA

    Science.gov (United States)

    Landwehr, Jurate M.; Coplen, Tyler B.; Stewart, David W.

    2013-01-01

    To assess spatial, seasonal, and source variability in stable isotopic composition of human drinking waters throughout the entire USA, we have constructed a database of δ18O and δ2H of US tap waters. An additional purpose was to create a publicly available dataset useful for evaluating the forensic applicability of these isotopes for human tissue source geolocation. Samples were obtained at 349 sites, from diverse population centres, grouped by surface hydrologic units for regional comparisons. Samples were taken concurrently during two contrasting seasons, summer and winter. Source supply (surface, groundwater, mixed, and cistern) and system (public and private) types were noted. The isotopic composition of tap waters exhibits large spatial and regional variation within each season as well as significant at-site differences between seasons at many locations, consistent with patterns found in environmental (river and precipitation) waters deriving from hydrologic processes influenced by geographic factors. However, anthropogenic factors, such as the population of a tap’s surrounding community and local availability from diverse sources, also influence the isotopic composition of tap waters. Even within a locale as small as a single metropolitan area, tap waters with greatly differing isotopic compositions can be found, so that tap water within a region may not exhibit the spatial or temporal coherence predicted for environmental water. Such heterogeneities can be confounding factors when attempting forensic inference of source water location, and they underscore the necessity of measurements, not just predictions, with which to characterize the isotopic composition of regional tap waters. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  9. Blood Lead Levels and Dental Caries in U.S. Children Who Do Not Drink Tap Water.

    Science.gov (United States)

    Sanders, Anne E; Slade, Gary D

    2018-02-01

    This study's purpose is to determine whether nonconsumption of tap water is associated with lower prevalence of elevated blood lead levels and higher prevalence of dental caries in children and adolescents. Cross-sectional data from the National Health and Nutrition Examination Survey 2005-2014 recorded drinking water source (n=15,604) and blood lead levels (n=12,373) for participants aged 2-19 years, and dental caries experience for the 2011-2014 subset (n=5,677). The threshold for elevated blood lead level was ≥3 μg/dL. A binary outcome indicated presence or absence of dental caries experience. Multivariable generalized linear models estimated adjusted prevalence ratios with 95% confidence limits. In analysis conducted in 2017, 15% of children and adolescents did not drink tap water, 3% had elevated blood lead levels ≥3 μg/dL, and 50% had dental caries experience. Children and adolescents who did not drink water were less likely than tap water drinkers to have an elevated blood lead level (adjusted prevalence ratios=0.62, 95% confidence limits=0.42, 0.90). Nonconsumers of tap water were more likely to have dental caries (adjusted prevalence ratios=1.13, 95% confidence limits=1.03, 1.23). Results persisted after adjustment for other covariates and using a higher threshold for elevated blood lead level. In this nationally representative U.S. survey, children and adolescents who did not drink tap water had lower prevalence of elevated blood lead levels and higher prevalence of dental caries than those who drank tap water. Copyright © 2018 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  10. Pseudo-outbreak of Cupriavidus pauculus infection at an outpatient clinic related to rinsing culturette swabs in tap water.

    Science.gov (United States)

    Balada-Llasat, Joan-Miquel; Elkins, Camille; Swyers, Lettie; Bannerman, Tammy; Pancholi, Preeti

    2010-07-01

    Cupriavidus pauculus is a water microorganism rarely isolated from clinical specimens. We describe a pseudo-outbreak in which multiple strains that were associated with moistening of culturette swabs with tap water were isolated from a single clinic before collecting the patient specimen.

  11. The role of domestic tap water on Acanthamoeba keratitis in non-contact lens wearers and validation of laboratory methods.

    Science.gov (United States)

    Koltas, Ismail Soner; Eroglu, Fadime; Erdem, Elif; Yagmur, Meltem; Tanır, Ferdi

    2015-09-01

    Acanthamoeba is increasingly recognized as an important cause of keratitis in non-contact lens wearers while contact lens wear is the leading risk factor for Acanthamoeba keratitis (AK). It is unlikely that the Acanthamoeba colonization is a feature which is effective only in patient's homes with infectious keratitis since the organism has been isolated from domestic tap water. Two hundred and thirty-one (231) corneal scrapings were taken from infectious keratitis cases, and four contact lens solutions and domestic tap waters were taken from 22 out of 44 AK-diagnosed patient's homes. Microscopic examination, culture, PCR, real-time PCR and DNA sequencing analyses were used for AK-diagnosed samples. The real-time PCR was the most sensitive (100 %) one among the methods used in diagnosis of AK. The 44 (19.0 %) out of 231 corneal scrapings, 4/4 (100 %) contact lens solution and 11/22 (50 %) of domestic tap water samples were found to be positive by real-time PCR for Acanthamoeba. A. griffini (T3), A. castellanii (T4) and A. jacobsi (T15) genotypes were obtained from corneal scrapings, contact lens solutions and domestic tap water samples taken from the patient's homes diagnosed with AK. The isolation of Acanthamoeba containing 6/22 (27.3 %) A. griffini (T3), 14/22 (63.6 %) A. castellanii (T4) and 2/22 (9.1 %) A. jacobsi (T15) from the domestic tap water outlets of 22 of 44 (50 %) of patient's homes revealed that is a significant source of these organisms. A. griffini (T3) and A. jacobsi (T15) genotypes have not been determined from AK cases in Turkey previously. Thus, we conclude that Acanthamoeba keratitis is associated with exposition of patients who has ocular trauma or ocular surface disease to domestic tap water in endemic or potentially endemic countries.

  12. Nitrotoga is selected over Nitrospira in newly assembled biofilm communities from a tap water source community at increased nitrite loading

    DEFF Research Database (Denmark)

    Kinnunen, Marta; Gülay, Arda; Albrechtsen, Hans-Jørgen

    2017-01-01

    Community assembly is a central topic in microbial ecology: how do assembly processes interact and what is the relative contribution of stochasticity and determinism? Here, we exposed replicate flow-through biofilm systems, fed with nitrite-supplemented tap water, to continuous immigration from...... a source community, present in the tap water, to determine the extent of selection and neutral processes in newly assembled biofilm communities at both the community and the functional guild (of nitrite-oxidizing bacteria, NOB) levels. The community composition of biofilms assembled under low and high...

  13. Development of a coprecipitation system for the speciation/preconcentration of chromium in tap waters

    Energy Technology Data Exchange (ETDEWEB)

    Karatepe, Aslihan, E-mail: karatepea@gmail.com [Nevsehir University, Faculty of Science and Arts, Department of Chemistry, 50000 Nevsehir (Turkey); Korkmaz, Esra [Bozok University, Faculty of Science and Arts, Department of Chemistry, Yozgat (Turkey); Soylak, Mustafa [Erciyes University, Faculty of Science and Arts, Chemistry Department, 38039 Kayseri (Turkey); Elci, Latif [Pamukkale University, Faculty of Science and Arts, Department of Chemistry, 20020 Denizli (Turkey)

    2010-01-15

    A method for the speciation of chromium(III), chromium(VI) and determination of total chromium based on coprecipitation of chromium(III) with dysprosium hydroxide has been investigated and applied to tap water samples. Chromium(III) was quantitatively recovered by the presented method, while the recovery values for chromium(VI) was below 10%. The influences of analytical parameters including amount of dysprosium(III), pH, centrifugation speed and sample volume for the quantitative precipitation were examined. No interferic effects were observed from alkali, earth alkali and some transition metals for the analyte ions. The detection limits (k = 3, N = 15) were 0.65 {mu}g/L for chromium(III) and 0.78 {mu}g/L for chromium(VI). The validation of the presented method was checked by the analysis of certified reference materials.

  14. Development of a coprecipitation system for the speciation/preconcentration of chromium in tap waters

    International Nuclear Information System (INIS)

    Karatepe, Aslihan; Korkmaz, Esra; Soylak, Mustafa; Elci, Latif

    2010-01-01

    A method for the speciation of chromium(III), chromium(VI) and determination of total chromium based on coprecipitation of chromium(III) with dysprosium hydroxide has been investigated and applied to tap water samples. Chromium(III) was quantitatively recovered by the presented method, while the recovery values for chromium(VI) was below 10%. The influences of analytical parameters including amount of dysprosium(III), pH, centrifugation speed and sample volume for the quantitative precipitation were examined. No interferic effects were observed from alkali, earth alkali and some transition metals for the analyte ions. The detection limits (k = 3, N = 15) were 0.65 μg/L for chromium(III) and 0.78 μg/L for chromium(VI). The validation of the presented method was checked by the analysis of certified reference materials.

  15. [One-time effects of drinking mineral water and tap water enriched with silver nanoparticles on the biochemical markers of liver condition and metabolic parameters in healthy rats].

    Science.gov (United States)

    Efimenko, N V; Frolkov, V K; Kozlova, V V; Kaisinova, A S; Chalaya, E N

    2017-12-05

     The objective of the present research was to study the influence of tap water enriched with silver nanoparticles (NP) as well as that of «Krasnoarmeysky» and «Essentuki №17» mineral waters after their single administration through the oral gavage to the rats on the metabolism of carbohydrates and lipids, the biochemical markers of the liver condition, and the endocrine profile in the healthy animals.  The laboratory animals (130 male Wistar rats) were allocated to thirteen groups comprised of 10 rats each as follows: 1st group (n=10) intact animals, 2nd group (5 minutes after the administration of silver NP (n=10), 3rd group (15 minutes after the of silver NP), 4th group (60 minutes after the administration of silver NP), 5th group (n=10) (5 minutes after the introduction of the «Krasnoarmeysky» mineral water), 6th group (n=10) (15 min after the introduction of the «Krasnoarmeysky» mineral water), 7th group (n=10), (60 minutes after the introduction of the «Krasnoarmeysky» mineral water) 8th group (n=10) (5 minutes after the introduction of the «Essentuki № 17» mineral water), 9th group (n=10) (15 min after the introduction of the «Essentuki № 7» mineral water) , 10th group (n=10) (60 minutes after the introduction of the «Essentuki №17» mineral water), 11th group (n=10) (5 minutes after administration of tap water (control),12th group (n=10) (15 minutes after administration of tap water (control), and 13th (n=10) group 60 minutes after administration of tap water (control).  The study has demonstrated that the tap water enriched with silver nanoparticles similar to the mineral waters caused stress reactions that are inferior to those induced by «Essentuki №17» mineral water in terms of the magnitude; however, the effect provoked by the tap water was of longer duration. Moreover, the tap water enriched with silver nanoparticles stimulates prooxidant reactions, and inhibit the activity of antioxidant protection. Silver nanoparticles

  16. Isolation and identification of Acanthamoeba strains from soil and tap water in Yanji, China.

    Science.gov (United States)

    Xuan, Yinghua; Shen, Yanqin; Ge, Yuxi; Yan, Gen; Zheng, Shanzi

    2017-06-30

    Members of the genus Acanthamoeba are widely distributed throughout the world, and some of them are considered pathogenic, as they are capable of causing corneal and central nervous system diseases. In this study, we isolated Acanthamoeba strains from soil and tap water in Yanji, China. We identified four strains of Acanthamoeba (CJY/S1, CJY/S2, CJY/S3, and CJY/W1) using mitochondrial DNA restriction fragment length polymorphism (mtDNA RFLP) analysis. Nuclear 18S rDNA sequences were used for phylogenetic analysis and species identification. Genotypic characterization of the isolates showed that they belonged to genotypes T4 (CJY/S1 and CJY/S2), T5 (CJY/S3), and T16 (CJY/W1). Sequence differences between CJY/S1 and Acanthamoeba castellanii Neff, CJY/S2 and Acanthamoeba KA/E7, and CJY/S3 and Acanthamoeba lenticulata 68-2 were 0.31, 0.2, and 0.26%, respectively. 18S ribosomal deoxyribonucleic acid (rDNA) of CJY/W1 had 99% sequence identity to that of Acanthamoeba sp. U/H-C1. Strains CJY/S1 and CJY/S2, isolated from soil, had similar mtDNA RFLP patterns, whereas strain CJY/W1, isolated from tap water, displayed a different pattern. To the best of our knowledge, this is the first report on the identification of genotypes T4, T5, and T16 from environmental sources in Yanji, China.

  17. Estimation of the consumption of cold tap water for microbiological risk assessment: An overview of studies and statistical analysis of data

    NARCIS (Netherlands)

    Mons, M.N.; Wielen, J.M.L. van der; Blokker, E.J.M.; Sinclair, M.I.; Hulshof, K.F.A.M.; Dangendorf, F.; Hunter, P.R.; Medema, G.J.

    2007-01-01

    The volume of cold tap water consumed is an essential element in quantitative microbial risk assessment. This paper presents a review of tap water consumption studies. Study designs were evaluated and statistical distributions were fitted to water consumption data from The Netherlands, Great

  18. Persistence of antibiotic resistance genes and bacterial community changes in drinking water treatment system: From drinking water source to tap water.

    Science.gov (United States)

    Su, Hao-Chang; Liu, You-Sheng; Pan, Chang-Gui; Chen, Jun; He, Liang-Ying; Ying, Guang-Guo

    2018-03-01

    As emerging contaminants, antibiotic resistance genes (ARGs) have become a public concern. This study aimed to investigate the occurrence and diversity of ARGs, and variation in the composition of bacterial communities in source water, drinking water treatment plants, and tap water in the Pearl River Delta region, South China. Various ARGs were present in the different types of water. Among the 27 target ARGs, floR and sul1 dominated in source water from three large rivers in the region. Pearson correlation analysis suggested that sul1, sul2, floR, and cmlA could be potential indicators for ARGs in water samples. The total abundance of the detected ARGs in tap water was much lower than that in source water. Sand filtration and sedimentation in drinking water treatment plants could effectively remove ARGs; in contrast, granular activated carbon filtration increased the abundance of ARGs. It was found that Pseudomonas may be involved in the proliferation and dissemination of ARGs in the studied drinking water treatment system. Bacteria and ARGs were still present in tap water after treatment, though they were significantly reduced. More research is needed to optimize the water treatment process for ARG removal. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Rate of Legionella pneumophila colonization in hospital hot water network after time flow taps installation.

    Science.gov (United States)

    Totaro, M; Valentini, P; Costa, A L; Giorgi, S; Casini, B; Baggiani, A

    2018-01-01

    In hospital water systems legionellae may be resistant to disinfectants in pipework, which is a problem particularly in areas where there is low flow or stagnation of water. We evaluated legionella colonization of a water network of an Italian hospital after time flow taps (TFTs) installation in proximity to dead legs. The water volume flushed was 64 L/day from May 2016, and 192 L/day from December 2016. Before TFTs installation, Legionella pneumophila sg2-14 was detected in all points (4 × 10 4  ± 3.1 × 10 4  cfu/L). All sites remained positive (2.9 × 10 4  ± 1.9 × 10 4  cfu/L) through November 2016. From December 2016 legionella persisted in one point only (2 × 10 2 to 6.8 × 10 3  cfu/L). TFTs with chemical disinfection may reduce legionella colonization associated with dead legs. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  20. Disinfection of Mycobacterium avium subspecies hominissuis in drinking tap water using ultraviolet germicidal irradiation.

    Science.gov (United States)

    Schiavano, Giuditta Fiorella; De Santi, Mauro; Sisti, Maurizio; Amagliani, Giulia; Brandi, Giorgio

    2017-09-13

    Nontuberculous mycobacteria are resistant to conventional water treatments, and are opportunistic human pathogen, particularly in hospitalized patients. The aim of this investigation was to assess the effectiveness of an ultraviolet UV-C lamp treatment against Mycobacterium avium subspecies hominissuis in drinking tap water. Ultraviolet treatments (0-192 mJ/cm 2 ) were performed using UV lamp immerged onto cylindrical glass tubes containing artificially contaminated water. The results showed that susceptibility to UV varied considerably according to the strains and the diameter of the tube. With a dose of 32 mJ/cm 2 , a significant inactivation (p < .05) of 3 log (99.9%) or more was obtained in only 5 of the 14 strains. To obtain a complete inactivation of all strains an irradiation of 192 mJ/cm 2 was needed, a dose that is much higher than the limits recommended by the international standards for UV disinfection of drinking water. In conclusion, it may be difficult to standardize a UV dose for the elimination of waterborne mycobacteria.

  1. Indoor Heating Drives Water Bacterial Growth and Community Metabolic Profile Changes in Building Tap Pipes during the Winter Season

    Directory of Open Access Journals (Sweden)

    Hai-Han Zhang

    2015-10-01

    Full Text Available The growth of the bacterial community harbored in indoor drinking water taps is regulated by external environmental factors, such as indoor temperature. However, the effect of indoor heating on bacterial regrowth associated with indoor drinking water taps is poorly understood. In the present work, flow cytometry and community-level sole-carbon-source utilization techniques were combined to explore the effects of indoor heating on water bacterial cell concentrations and community carbon metabolic profiles in building tap pipes during the winter season. The results showed that the temperature of water stagnated overnight (“before” in the indoor water pipes was 15–17 °C, and the water temperature decreased to 4–6 °C after flushing for 10 min (“flushed”. The highest bacterial cell number was observed in water stagnated overnight, and was 5–11 times higher than that of flushed water. Meanwhile, a significantly higher bacterial community metabolic activity (AWCD590nm was also found in overnight stagnation water samples. The significant “flushed” and “taps” values indicated that the AWCD590nm, and bacterial cell number varied among the taps within the flushed group (p < 0.01. Heatmap fingerprints and principle component analyses (PCA revealed a significant discrimination bacterial community functional metabolic profiles in the water stagnated overnight and flushed water. Serine, threonine, glucose-phosphate, ketobutyric acid, phenylethylamine, glycerol, putrescine were significantly used by “before” water samples. The results suggested that water stagnated at higher temperature should be treated before drinking because of bacterial regrowth. The data from this work provides useful information on reasonable utilization of drinking water after stagnation in indoor pipes during indoor heating periods.

  2. Health improvement of domestic hot tap water supply Gusev, Kaliningrad Region, Russia. Make-up water tank project. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Aagaard, Joergen

    1998-07-01

    This report describes the project `Health Improvement of Domestic Hot Tap Water Supply, Gusev, Kaliningrad, Russia`, which was carried out in the autumn of 1996 and financed by the Danish Environmental Protection Agency, the Danish Energy Agency and Gusev Municipality. The project proposal and application outlined the following objectives: Erection of system so that hot tap water, which is tapped directly from the district heating system, obtains an acceptable quality in health terms; Complete training and education, so that the plant can be operated and maintained by the power station`s staff and rehabilitation projects within supply of domestic water and district heating can be promoted to the greatest possible extent; Systems for heat treatment of make-up water were implemented in less than three months; The project was carried out in close Danish-Russian co-operation from the beginning of engineering to the commissioning and resulted in transfer and demonstration of know-how and technology; Information was recorded on the existing domestic water and heat supply systems as well as on the treatment of sewage, and recommendations for rehabilitation projects were made. Previously, when the temperature in the district heating system was relatively high, a heat treatment apparently took place in the district heating system. However, due to the current poor economic situation there are no means with which to buy the fuel quantities necessary to maintain the previously normal district heating temperature. In the new concept the cold make-up water is heated to >80 deg. C as required by the health authorities before it is led to the district heating return system and subsequently heated to the actual supply temperature of 50-60 deg. C. The energy consumption in the two concepts is approximately the same. A 1,000 m{sup 3} tank with heating coils was erected between the make-up water system and the district heating system. The tank should equalise the daily capacity

  3. Quantifying tap-to-household water quality deterioration in urban communities in Vellore, India: The impact of spatial assumptions.

    Science.gov (United States)

    Alarcon Falconi, Tania M; Kulinkina, Alexandra V; Mohan, Venkata Raghava; Francis, Mark R; Kattula, Deepthi; Sarkar, Rajiv; Ward, Honorine; Kang, Gagandeep; Balraj, Vinohar; Naumova, Elena N

    2017-01-01

    Municipal water sources in India have been found to be highly contaminated, with further water quality deterioration occurring during household storage. Quantifying water quality deterioration requires knowledge about the exact source tap and length of water storage at the household, which is not usually known. This study presents a methodology to link source and household stored water, and explores the effects of spatial assumptions on the association between tap-to-household water quality deterioration and enteric infections in two semi-urban slums of Vellore, India. To determine a possible water source for each household sample, we paired household and tap samples collected on the same day using three spatial approaches implemented in GIS: minimum Euclidean distance; minimum network distance; and inverse network-distance weighted average. Logistic and Poisson regression models were used to determine associations between water quality deterioration and household-level characteristics, and between diarrheal cases and water quality deterioration. On average, 60% of households had higher fecal coliform concentrations in household samples than at source taps. Only the weighted average approach detected a higher risk of water quality deterioration for households that do not purify water and that have animals in the home (RR=1.50 [1.03, 2.18], p=0.033); and showed that households with water quality deterioration were more likely to report diarrheal cases (OR=3.08 [1.21, 8.18], p=0.02). Studies to assess contamination between source and household are rare due to methodological challenges and high costs associated with collecting paired samples. Our study demonstrated it is possible to derive useful spatial links between samples post hoc; and that the pairing approach affects the conclusions related to associations between enteric infections and water quality deterioration. Copyright © 2016 Elsevier GmbH. All rights reserved.

  4. Geothermal brine well: Mile-deep drill hole may tap ore-bearing magmatic water and rocks Undergoing Metamorphism

    Science.gov (United States)

    White, D.E.; Anderson, E.T.; Grubbs, D.K.

    1963-01-01

    A deep geothermal well in California has tapped a very saline brine extraordinarily high in heavy metals and other rare elements; copper and silver are precipitated during brine production. Preliminary evidence suggests that the brine may be pure magmatic water and an active ore-forming solution. Metamorphism of relatively young rocks may also be occurring within accessible depths.

  5. Effective Dose Radon 222 of the Tap Water in Children and Adults People; Minab City, Iran.

    Science.gov (United States)

    Fakhri, Yadolah; Kargosha, Morteza; Langarizadeh, Ghazaleh; Zandsalimi, Yahya; Rasouli Amirhajeloo, Leila; Moradi, Mahboobeh; Moradi, Bigard; Mirzaei, Maryam

    2015-09-01

    (222)Rn is a radioactive, odorless, and colorless element which has a half-life of 3.83 days. One of (222)Rn main resources are Groundwater (wells, springs, etc.). Hence, the use of groundwater with high concentration of (222)Rn can increase the risk of lung and stomach cancers. Concentration of (222)Rn in tap water of Minab city in two temperatures 5 and 15 ºC was measured by radon meter model RTM1668-2. The effective dose was calculated by equations proposed by UNSCEAR. Geometric mean concentration of (222)Rn in drinking water was found to be 0.78±0.06 and 0.46±0.04 Bq/l at 5 and 15 ̊C (p value<0.05), respectively. The effective doses were 0.006 and 0.003 mSv/y for adults, and 0.011 and 0.007 mSv/y for the children, respectively (p value<0.05). Besides, the effective dose for adult through inhaling (222)Rn at 5 and 15 ̊C were estimated 0.0021 and 0.0012mSv/y, respectively. Geometric mean concentration in (222)Rn drinking water and effective dose received from drinking water and inhalation of (222)Rn is lower than WHO and EPA standard limits. Increasing temperature of drinking water will decrease the effective dose received. Annual Effective dose received from inhalation and consumption of (222)Rn in drinking water in children is more than adults.

  6. Thermodynamic and structural studies of mixed monolayers: Mutual mixing of DPPC and DPPG with DoTAP at the air-water interface

    Energy Technology Data Exchange (ETDEWEB)

    Panda, Amiya Kumar, E-mail: akpanda1@yahoo.com [Department of Chemistry, University of North Bengal, Darjeeling-734 013, West Bengal (India); Vasilev, Krasimir [Mawson Institute for Advanced Manufacturing, Mawson Lakes, University of South Australia, SA-5095 (Australia); Orgeig, Sandra [Sansom Institute for Health Research and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA 5000 (Australia); Prestidge, Clive A. [Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA 5095 (Australia)

    2010-05-10

    Phospholipid monomolecular films at the air-water interface are useful model membranes to understand miscibility among various components. Surface pressure ({pi})-area (A) isotherms of pure and mixed monolayers of dioleoyltrimethylammonium propane (DoTAP)-dipalmitoylphosphatidylcholine (DPPC) and DoTAP-dipalmitoyphosphatidylglycerol (DPPG) were constructed using a surface balance. DPPC and DPPG produced isotherms as expected and reported earlier. DoTAP, an unsaturated lipid, demonstrated a continuous {pi}-A isotherm. Associative interactions were identified in DPPC-DoTAP mixtures compared to the pure components, while DPPG-DoTAP mixtures showed repulsive interaction up to an equimolar ratio. Compression moduli of the monolayers revealed that DPPC-DoTAP mixtures had increasing stability with increasing surface pressure, but addition of DoTAP to DPPG showed instability at low and intermediate concentrations. In both cases increased stability was returned at higher X{sub DoTAP} values and surface pressures. Lipid monolayer film thickness values, determined on a gold coated glass substrate by surface plasmon resonance spectroscopy (SPR), indicated a systematic change in height profile for DPPC-DoTAP mixtures with increasing X{sub DoTAP}. However, DPPG-DoTAP mixed monolayer systems demonstrated a biphasic response. The SPR data were in excellent agreement with our interpretation of the structure of solid supported lipid monolayers.

  7. The impact of the hot tap water load pattern in the industrial hall on the energy yield from solar collectors

    Science.gov (United States)

    Fidorów-Kaprawyl, Natalia; Dudkiewicz, Edyta

    2017-11-01

    The systems using solar energy, popular in Poland, can be used to supply hot water for the installation used by employees of industrial halls. In manufacturing plants, employing a large number of people, the demand for hot water is practically constant throughout the year and is characterized by periodic use at the end of each work shift. Dynamics of the hot water consumption depends on the number of shifts as well as working days and holidays. Additionally the maximum hot tap water demand occurs in the whole period of installation operation. In polish climatic conditions the solar collectors' systems have the largest capacity in the summer, while in winter they need to be assisted. Beside that the supply of renewable energy is uneven and depends on weather conditions. In the paper the one-hour step analysis concerning the dependence of the load pattern of the hot tap water preparation system on the energy yield from solar collectors had been performed.

  8. Pollution by Nonylphenol in river, tap water, and aquatic in an acid rain-plagued city in southwest China.

    Science.gov (United States)

    Jie, Yu; Jie, Zhou; Ya, Luo; Xuesong, Yang; Jing, Yang; Yu, Yang; Jiaqi, Yang; Jie, Xu

    2017-06-01

    Nonylphenol (NP) has provoked much environmental concern because of their weak estrogenic activities; however, few data are available on the environmental levels of the chemical in China. Environmental or river samples were assayed for NP by high-performance liquid chromatography (HPLC) technique. The concentration for NP measured in Xiangjiang River, ranging from 0.174 to 3.411 μg/L with a mean value of 1.73 μg/L, was lower than the Water Quality Criteria for NP of the US (6.6 μg/L); however, the NP concentration was maintained at a higher level compare to the developed countries and other civil cities. NP concentration in downstream water was markedly higher than that both in midstream and upstream water. Tissue accumulation of NP was observed in aquatics. A ratio of mean concentration of NP in aquatic (chlamys farreri and hemiculter leucisculus) to that in river water was 241 and 1087, respectively. The presence of NP in tap water in two urban districts of Zunyi was common with a detectable rate reached 100.0%. Mean NP concentration in terminal tap water in Huichuan district was six times as high as Honghuagang district, which was above Standards for the Drinking Water Quality for Phenols of China (2 μg/L). The pollution of NP in Xiangjiang River, tap water, and aquatic in Zunyi belongs to moderate or severe level in the world.

  9. Investigation of Locally Made Ceramic Filter for Household Water Treatment

    OpenAIRE

    Nurmiyanto, Awaluddin; Prasetya, Agus

    2012-01-01

    This research have objective to develop and evaluate the performance of ceramic filter in using locally available material at Yogyakarta. Ceramic filter are made by pressing a mixture of clay, discarded pottery (grog) and combustible material (coconut fiber) into the molder. Curving processes are then applied to form tubular shape before firing it using kiln (1005°C). Filtration test were performed gravitationally by flowing well water into ceramic filter. Filtered water quality was complying...

  10. Occurrence, Source, and Human Infection Potential of Cryptosporidium and Giardia spp. in Source and Tap Water in Shanghai, China▿

    Science.gov (United States)

    Feng, Yaoyu; Zhao, Xukun; Chen, Jiaxu; Jin, Wei; Zhou, Xiaonong; Li, Na; Wang, Lin; Xiao, Lihua

    2011-01-01

    Genotyping studies on the source and human infection potential of Cryptosporidium oocysts in water have been almost exclusively conducted in industrialized nations. In this study, 50 source water samples and 30 tap water samples were collected in Shanghai, China, and analyzed by the U.S. Environmental Protection Agency (EPA) Method 1623. To find a cost-effective method to replace the filtration procedure, the water samples were also concentrated by calcium carbonate flocculation (CCF). Of the 50 source water samples, 32% were positive for Cryptosporidium and 18% for Giardia by Method 1623, whereas 22% were positive for Cryptosporidium and 10% for Giardia by microscopy of CCF concentrates. When CCF was combined with PCR for detection, the occurrence of Cryptosporidium (28%) was similar to that obtained by Method 1623. Genotyping of Cryptosporidium in 17 water samples identified the presence of C. andersoni in 14 water samples, C. suis in 7 water samples, C. baileyi in 2 water samples, C. meleagridis in 1 water sample, and C. hominis in 1 water sample. Therefore, farm animals, especially cattle and pigs, were the major sources of water contamination in Shanghai source water, and most oocysts found in source water in the area were not infectious to humans. Cryptosporidium oocysts were found in 2 of 30 tap water samples. The combined use of CCF for concentration and PCR for detection and genotyping provides a less expensive alternative to filtration and fluorescence microscopy for accurate assessment of Cryptosporidium contamination in water, although the results from this method are semiquantitative. PMID:21498768

  11. Potential for Hepa filter damage from water spray systems in filter plenums

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, W.; Fretthold, J.K.; Slawsld, J.W.

    1997-01-01

    The water spray systems in high efficiency particulate air (HEPA) filter plenums that are used in nearly all Department of Energy (DOE) facilities for protection against fire was designed under the assumption that the HEPA filters would not be damaged by the water sprays. The most likely scenario for filter damage involves filter plugging by the water spray, followed by the fan blowing out the filter medium. A number of controlled laboratory tests that were previously conducted in the late 1980s are reviewed in this paper to provide a technical basis for the potential HEPA filter damage by the water spray system in HEPA filter plenums. In addition to the laboratory tests, the scenario for HEPA filter damage during fires has also occurred in the field. Afire in a four-stage, HEPA filter plenum at Rocky Flats in 1980 caused the first three stages of HEPA filters to blow out of their housing and the fourth stage to severely bow. Details of this recently declassified fire are presented in this paper. Although these previous findings suggest serious potential problems exist with the current water spray system in filter plenum , additional studies are required to confirm unequivocally that DOE`s critical facilities are at risk.

  12. Water washable stainless steel HEPA filter

    Science.gov (United States)

    Phillips, Terrance D.

    2001-01-01

    The invention is a high efficiency particulate (HEPA) filter apparatus and system, and method for assaying particulates. The HEPA filter provides for capture of 99.99% or greater of particulates from a gas stream, with collection of particulates on the surface of the filter media. The invention provides a filter system that can be cleaned and regenerated in situ.

  13. Pseudomonas aeruginosa Outbreak in a Neonatal Intensive Care Unit Attributed to Hospital Tap Water.

    Science.gov (United States)

    Bicking Kinsey, Cara; Koirala, Samir; Solomon, Benjamin; Rosenberg, Jon; Robinson, Byron F; Neri, Antonio; Laufer Halpin, Alison; Arduino, Matthew J; Moulton-Meissner, Heather; Noble-Wang, Judith; Chea, Nora; Gould, Carolyn V

    2017-07-01

    OBJECTIVE To investigate an outbreak of Pseudomonas aeruginosa infections and colonization in a neonatal intensive care unit. DESIGN Infection control assessment, environmental evaluation, and case-control study. SETTING Newly built community-based hospital, 28-bed neonatal intensive care unit. PATIENTS Neonatal intensive care unit patients receiving care between June 1, 2013, and September 30, 2014. METHODS Case finding was performed through microbiology record review. Infection control observations, interviews, and environmental assessment were performed. A matched case-control study was conducted to identify risk factors for P. aeruginosa infection. Patient and environmental isolates were collected for pulsed-field gel electrophoresis to determine strain relatedness. RESULTS In total, 31 cases were identified. Case clusters were temporally associated with absence of point-of-use filters on faucets in patient rooms. After adjusting for gestational age, case patients were more likely to have been in a room without a point-of-use filter (odds ratio [OR], 37.55; 95% confidence interval [CI], 7.16-∞). Case patients had higher odds of exposure to peripherally inserted central catheters (OR, 7.20; 95% CI, 1.75-37.30) and invasive ventilation (OR, 5.79; 95% CI, 1.39-30.62). Of 42 environmental samples, 28 (67%) grew P. aeruginosa. Isolates from the 2 most recent case patients were indistinguishable by pulsed-field gel electrophoresis from water-related samples obtained from these case-patient rooms. CONCLUSIONS This outbreak was attributed to contaminated water. Interruption of the outbreak with point-of-use filters provided a short-term solution; however, eradication of P. aeruginosa in water and fixtures was necessary to protect patients. This outbreak highlights the importance of understanding the risks of stagnant water in healthcare facilities. Infect Control Hosp Epidemiol 2017;38:801-808.

  14. Irrigation of continent catheterizable ileal pouches: tap water can replace sterile solutions because it is safe, easy, and economical.

    Science.gov (United States)

    Birkhäuser, Frédéric D; Zehnder, Pascal; Roth, Beat; Schürch, Leander; Ochsner, Katharina; Willener, Rita; Thalmann, George N; Burkhard, Fiona C; Studer, Urs E

    2011-04-01

    Continent catheterizable ileal pouches require regular irrigations to reduce the risk of bacteriuria and urinary tract infections (UTIs). Our aim was to compare the UTI rate, patient friendliness, and costs of standard sterile irrigation versus irrigation with tap water. Twenty-three patients participated in a prospective randomized two-arm crossover single-center trial. Aseptic intermittent self-catheterization (ISC) combined with sterile sodium chloride (NaCl) 0.9% irrigation was compared with clean ISC and irrigation with tap water (H(2)O) during two study periods of 90 d each. Patients underwent daily pouch irrigations with NaCl 0.9% solution or tap water. Urine nitrite dipstick tests were evaluated daily; urine culture (UC) and patient friendliness were evaluated monthly. Costs were documented. A total of 3916 study days with nitrite testing and irrigation were analyzed, 1876 (48%) in the NaCl arm and 2040 (52%) in the H(2)O arm. In the NaCl arm, 418 study days (22%) with nitrite-positive dipsticks were recorded, 219 d (11%) in the H(2)O arm, significantly fewer (p=0.01). Of the 149 UCs, 96 (64%) were positive, 48 in each arm, revealing a total of 16 different germs. All patients preferred the H(2)O method. Monthly costs were up to 20 times lower in the H(2)O arm. Pouch irrigation with sterile NaCl 0.9% solution and tap water had comparable rates of positive UC. Irrigation with tap water significantly lowered the incidence of nitrite-positive study days and was substantially less costly and more patient friendly than NaCl irrigation. We therefore recommend the use of tap water (or bottled water) instead of sterile NaCl 0.9% solution for daily irrigation of continent catheterizable ileal pouches. Australian New Zealand Clinical Trials Registry, ACTRN12610000618055, http://www.ANZCTR.org.au/ACTRN12610000618055.aspx. Copyright © 2011 European Association of Urology. Published by Elsevier B.V. All rights reserved.

  15. Tapping Into Water: Key Considerations for Achieving Excellence in School Drinking Water Access

    Science.gov (United States)

    Hecht, Kenneth; Hampton, Karla E.; Grumbach, Jacob M.; Braff-Guajardo, Ellen; Brindis, Claire D.

    2014-01-01

    Objectives. We examined free drinking water access in schools. Methods. We conducted cross-sectional interviews with administrators from 240 California public schools from May to November 2011 to examine the proportion of schools that met excellent water access criteria (i.e., location, density, type, maintenance, and appeal of water sources), school-level characteristics associated with excellent water access, and barriers to improvements. Results. No schools met all criteria for excellent water access. High schools and middle schools had lower fountain:student ratios than elementary schools (odds ratio [OR] = 0.06; 95% confidence interval [CI] = 0.02, 0.20; OR = 0.30, 95% CI = 0.12, 0.70). Rural schools were more likely to offer a nonfountain water source than city schools (OR = 5.0; 95% CI = 1.74, 14.70). Newer schools were more likely to maintain water sources than older schools (OR = 0.98; 95% CI = 0.97, 1.00). Schools that offered free water in food service areas increased from pre- to postimplementation of California’s school water policy (72%–83%; P water included cost of programs and other pressing concerns. Conclusions. Awareness of the benefits related to school drinking water provision and funding may help communities achieve excellence in drinking water access. PMID:24832141

  16. Tapping into water: key considerations for achieving excellence in school drinking water access.

    Science.gov (United States)

    Patel, Anisha I; Hecht, Kenneth; Hampton, Karla E; Grumbach, Jacob M; Braff-Guajardo, Ellen; Brindis, Claire D

    2014-07-01

    We examined free drinking water access in schools. We conducted cross-sectional interviews with administrators from 240 California public schools from May to November 2011 to examine the proportion of schools that met excellent water access criteria (i.e., location, density, type, maintenance, and appeal of water sources), school-level characteristics associated with excellent water access, and barriers to improvements. No schools met all criteria for excellent water access. High schools and middle schools had lower fountain:student ratios than elementary schools (odds ratio [OR] = 0.06; 95% confidence interval [CI] = 0.02, 0.20; OR = 0.30, 95% CI = 0.12, 0.70). Rural schools were more likely to offer a nonfountain water source than city schools (OR = 5.0; 95% CI = 1.74, 14.70). Newer schools were more likely to maintain water sources than older schools (OR = 0.98; 95% CI = 0.97, 1.00). Schools that offered free water in food service areas increased from pre- to postimplementation of California's school water policy (72%-83%; P improving school water included cost of programs and other pressing concerns. Awareness of the benefits related to school drinking water provision and funding may help communities achieve excellence in drinking water access.

  17. Development of a Certified Reference Material (NMIJ CRM 7203-a) for Elemental Analysis of Tap Water.

    Science.gov (United States)

    Zhu, Yanbei; Narukawa, Tomohiro; Inagaki, Kazumi; Miyashita, Shin-Ichi; Kuroiwa, Takayoshi; Ariga, Tomoko; Kudo, Izumi; Koguchi, Masae; Heo, Sung Woo; Suh, Jung Ki; Lee, Kyoung-Seok; Yim, Yong-Hyeon; Lim, Youngran

    2017-01-01

    A certified reference material (CRM), NMIJ CRM 7203-a, was developed for the elemental analysis of tap water. At least two independent analytical methods were applied to characterize the certified value of each element. The elements certified in the present CRM were as follows: Al, As, B, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, Pb, Rb, Sb, Se, Sr, and Zn. The certified value for each element was given as the (property value ± expanded uncertainty), with a coverage factor of 2 for the expanded uncertainty. The expanded uncertainties were estimated while considering the contribution of the analytical methods, the method-to-method variance, the sample homogeneity, the long-term stability, and the concentrations of the standard solutions for calibration. The concentration of Hg (0.39 μg kg -1 ) was given as the information value, since loss of Hg was observed when the sample was stored at room temperature and exposed to light. The certified values of selected elements were confirmed by a co-analysis carried out independently by the NMIJ (Japan) and the KRISS (Korea).

  18. Health risk assessment of trihalomethanes from tap water in Karachi, Pakistan

    International Nuclear Information System (INIS)

    Karim, Z.; Mumtaz, M.; Kamal, T.

    2011-01-01

    Risk assessment study of trihalomethanes (THMs) through different exposure pathways is based on the results of THMs concentration in tap water samples collected from various locations of Karachi city. The lifetime cancer risk and hazard index of each THM species were used to estimate the health risk from THM exposure through oral ingestion and dermal absorption. Exposure to CHCl/sub 3/ either through ingestion or dermal contact was found to be the most important pathway for cancer risks from THMs. It was also found that the residents of Karachi have a higher risk of cancer through oral ingestion than through the dermal absorption. The mean hazard index value of Total trihalomethanes (TTHMs) through oral ingestion and dermal absorption was calculated to be 8.84 X 10/sup -2/ and 4.39 X 10/sup -3/, respectively. The results of hazard index were found lower than unity, which did not indicate the non-cancer effects of THMs. On the basis of cancer risk analysis, it is expected that approximately 2 of the 18 million population of Karachi could get cancer each year due to exposure to the THMs. (author)

  19. Synergistic Effect of Molybdate and Monoethanolamine on Corrosion Inhibition of Ductile Cast Iron in Tap Water

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K. T.; Kim, Y. S. [Andong National University, Andong (Korea, Republic of); Chang, H. Y.; Lim, B. T.; Park, H. B. [KEPCO Engineering and Construction Company, Gimcheon (Korea, Republic of)

    2017-02-15

    A synergistic effect was observed in the combination of nitrite and ethanolamines. Ethanolamine is one of the representative organic corrosion inhibitors and can be categorized as adsorption type. However, nitrosamines can form when amines mix with sodium nitrite. Since nitrosamine is a carcinogen, the co-addition of nitrite and ethanolamine will be not practical, and thus, a non-toxic combination of inhibitors shall be needed. In order to maximize the effect of monoethanolamine, we focused on the addition of molybdate. Molybdate has been used to alternate the addition of chromate, but it showed insufficient oxidizing power relative to corrosion inhibitors. This work evaluated the synergistic effect of the co-addition of molybdate and monoethanolamine, and its corrosion mechanism was elucidated. A high concentration of molybdate or monoethanolamine was needed to inhibit the corrosion of ductile cast iron in tap water, but in the case of the co-addition of molybdate and monoethanolamine, a synergistic effect was observed. This synergistic effect could be attributed to the molybdate that partly oxidizes the metallic surface and the monoethanolamine that is simultaneously adsorbed on the graphite surface. This adsorbed layer then acts as the barrier layer that mitigates galvanic corrosion between the graphite and the matrix.

  20. Reduction in pesticide residue levels in olives by ozonated and tap water treatments and their transfer into olive oil.

    Science.gov (United States)

    Kırış, Sevilay; Velioglu, Yakup Sedat

    2016-01-01

    The effects of different wash times (2 and 5 min) with tap and ozonated water on the removal of nine pesticides from olives and the transfer ratios of these pesticides during olive oil production were determined. The reliability of the analytical methods was also tested. The applied methods of analysis were found to be suitable based on linearity, trueness, repeatability, selectivity and limit of quantification all the pesticides tested. All tap and ozonated water wash cycles removed a significant quantity of the pesticides from the olives, with a few exceptions. Generally, extending the wash time increased the pesticide reduction with ozonated water, but did not make significant differences with tap water. During olive oil processing, depending on the processing technique and physicochemical properties of the pesticides, eight of nine pesticides were concentrated into olive oil (processing factor > 1) with almost no significant difference between treatments. Imidacloprid did not pass into olive oil. Ozonated water wash for 5 min reduced chlorpyrifos, β-cyfluthrin, α-cypermethrin and imidacloprid contents by 38%, 50%, 55% and 61% respectively in olives.

  1. Enhanced chlorine resistance of tap water-adapted Legionella pneumophila as compared with agar medium-passaged strains.

    Science.gov (United States)

    Kuchta, J M; States, S J; McGlaughlin, J E; Overmeyer, J H; Wadowsky, R M; McNamara, A M; Wolford, R S; Yee, R B

    1985-07-01

    Previous studies have shown that bacteria maintained in a low-nutrient "natural" environment such as swimming pool water are much more resistant to disinfection by various chemical agents than strains maintained on rich media. In the present study a comparison was made of the chlorine (Cl2) susceptibility of hot-water tank isolates of Legionella pneumophila maintained in tap water and strains passaged on either nonselective buffered charcoal-yeast extract or selective differential glycine-vancomycin-polymyxin agar medium. Our earlier work has shown that environmental and clinical isolates of L. pneumophila maintained on agar medium are much more resistant to Cl2 than coliforms are. Under the present experimental conditions (21 degrees C, pH 7.6 to 8.0, and 0.25 mg of free residual Cl2 per liter, we found the tap water-maintained L. pneumophila strains to be even more resistant than the agar-passaged isolates. Under these conditions, 99% kill of tap water-maintained strains of L. pneumophila was usually achieved within 60 to 90 min compared with 10 min for agar-passaged strains. Samples from plumbing fixtures in a hospital yielded legionellae which were "super"-chlorine resistant when assayed under natural conditions. After one agar passage their resistance dropped to levels of comparable strains which had not been previously exposed to additional chlorination. These studies more closely approximate natural conditions than our previous work and show that tap water-maintained L. pneumophila is even more resistant to Cl2 than its already resistant agar medium-passaged counterpart.

  2. Granular filters for water treatment: heterogeneity and diagnostic tools

    DEFF Research Database (Denmark)

    Lopato, Laure Rose

    in a proactive manner. They can also be used to optimize the filtration process. However, further research is necessary to relate the information obtained through the tools to specific causes. New tools such as the total dissolved gas probe, salt tracers and ammonium profiles are presented. Potential tools from......Rapid granular filters are the most commonly used filters in drinking water treatment plants and are the focus of this PhD study. They are usually constructed with sand, anthracite, activated carbon, garnet sand, and ilmenite and have filtration rates ranging from 3 to 15 m/h. Filters are often...... and reliable filter performance, and water quality compliance. A salt tracer tool is developed to be used in full-scale filters to investigate the heterogeneity of the filter bed. The tool allows the pore velocity to be estimated in different locations of the filter bed during the duration of a filter run...

  3. Estimating the frequency of tap-water exposures to Mycobacterium avium complex in the U.S. population with advanced AIDS.

    Science.gov (United States)

    Rice, Glenn; Wright, J Michael; Boutin, Brenda; Swartout, Jeff; Rodgers, Pam; Niemuth, Nancy; Broder, Michael

    Mycobacterium avium complex (MAC) is a group of ubiquitous and opportunistic bacterial pathogens included on the U.S. Environmental Protection Agency Drinking Water Contaminant Candidate List. The risk of contracting a disseminated MAC infection is primarily limited to the immunocompromised, including those with advanced acquired immunodeficiency syndrome (AIDS). These infections likely result from exposures to MAC-contaminated tap water, food, or soil, although the epidemiologic evidence is insufficient to implicate a specific medium. The objective of this study was to assess tap water exposure to MAC in the U.S. population with advanced AIDS, defined here as having fewer than 100 CD4(+) cells/mm(3) of blood. Using limited data on the detection of MAC and self-reported post-tap treatment practices, two exposure models were developed to simulate the likelihood of exposure to MAC via tap water consumption in this sensitive population. The first model integrated data from studies that described sources of water for consumption and post-tap treatment rates in cohorts infected with human immunodeficiency virus (HIV(+)). The second model used data from a study that categorized the fraction of water intake consisting of tap water that was not further treated. Approximately 1500 individuals with advanced AIDS were estimated to ingest tap water with detectable concentrations of MAC organisms daily. Additional studies on tap-water use in U.S. HIV(+) populations are needed to confirm these findings. Longitudinal and cross-sectional studies on the occurrence of MAC in tap water, particularly in regions with large HIV(+)/AIDS populations, would help address some of the uncertainty in these exposure estimates.

  4. Fecal indicators and zoonotic pathogens in household drinking water taps fed from rainwater tanks in Southeast Queensland, Australia.

    Science.gov (United States)

    Ahmed, W; Hodgers, L; Sidhu, J P S; Toze, S

    2012-01-01

    In this study, the microbiological quality of household tap water samples fed from rainwater tanks was assessed by monitoring the numbers of Escherichia coli bacteria and enterococci from 24 households in Southeast Queensland (SEQ), Australia. Quantitative PCR (qPCR) was also used for the quantitative detection of zoonotic pathogens in water samples from rainwater tanks and connected household taps. The numbers of zoonotic pathogens were also estimated in fecal samples from possums and various species of birds by using qPCR, as possums and birds are considered to be the potential sources of fecal contamination in roof-harvested rainwater (RHRW). Among the 24 households, 63% of rainwater tank and 58% of connected household tap water (CHTW) samples contained E. coli and exceeded Australian drinking water guidelines of rainwater tanks and 83% of CHTW samples also contained enterococci. In all, 21%, 4%, and 13% of rainwater tank samples contained Campylobacter spp., Salmonella spp., and Giardia lamblia, respectively. Similarly, 21% of rainwater tank and 13% of CHTW samples contained Campylobacter spp. and G. lamblia, respectively. The number of E. coli (P = 0.78), Enterococcus (P = 0.64), Campylobacter (P = 0.44), and G. lamblia (P = 0.50) cells in rainwater tanks did not differ significantly from the numbers observed in the CHTW samples. Among the 40 possum fecal samples tested, Campylobacter spp., Cryptosporidium parvum, and G. lamblia were detected in 60%, 13%, and 30% of samples, respectively. Among the 38 bird fecal samples tested, Campylobacter spp., Salmonella spp., C. parvum, and G. lamblia were detected in 24%, 11%, 5%, and 13% of the samples, respectively. Household tap water samples fed from rainwater tanks tested in the study appeared to be highly variable. Regular cleaning of roofs and gutters, along with pruning of overhanging tree branches, might also prove effective in reducing animal fecal contamination of rainwater tanks.

  5. Dichlorvos (DDVP residue removal from tomato by washing with tap and ozone water, a commercial detergent solution and ultrasonic cleaner

    Directory of Open Access Journals (Sweden)

    Ali HESHMATI

    Full Text Available Abstract Dichlorvos (DDVP is one of the most consumption chlorinated organophosphate insecticide used on tomato. The knowledge about the influence of postharvest household processes on the levels of DDVP residues in vegetables is required to estimate dietary exposure. In this study, the removal of sprayed dichlorvos (DDVP on tomato by washing with tap, ozonated water (in dosages of 2, 4 and 6 mg ozone/L, a commercial detergent solution (in concentration of 1, 2 and 3% and ultrasonic cleaner (with power of 100, 200 and 300 W was investigated. DDVP residue was determined by gas chromatography with electron capture detector. Washing processes led to the significant reduction of DDVP. The gradual increase in the percentage of the removal was observed due to increment of washing time, ozone dosage, and concentration of detergent solution as well as ultrasonic power. The maximum removal percentage of DDVP after 15 min of washing with tap and ozonated water, a detergent solution and ultrasonic cleaner was 30.7, 91.9, 70.7, and 88.9%, respectively. In general, results indicated washing with tap, ozonated water, a detergent solution and ultrasonic cleaning are effective methods for removal of DDVP from tomato and reduction of its dietary exposure without influence on product quality.

  6. Aspirin and paracetamol removal using a commercial micro-sized TiO2catalyst in deionized and tap water.

    Science.gov (United States)

    Bianchi, Claudia L; Sacchi, Benedetta; Pirola, Carlo; Demartin, Francesco; Cerrato, Giuseppina; Morandi, Sara; Capucci, Valentino

    2017-05-01

    Micro-sized TiO 2 catalyst was employed to degrade pharmaceutical compounds, i.e. aspirin and paracetamol, two of the most widely used drugs, purchasable without prescription. Their active agents, acetylsalicylic acid and acetaminophen, are characterized by different substituent groups, linked to the aromatic ring, which affect both the photodegradation and mineralization processes. The experimental conditions highlight the relationship between the nature of the pristine molecules, their degradation mechanisms, their mutual interference and the water's role. The research started from model systems with a single pollutant to the mixture of them and finally by moving from deionized water to tap water.

  7. The evaluation of the classical Kirby-Bauer antibiogram method for the determination of antibiotic resistant microorganisms in tap water

    Directory of Open Access Journals (Sweden)

    Siedlecka Agata

    2017-01-01

    Full Text Available Water supply systems are the main source of potable water for many inhabitants. The European Union and Polish laws demand high quality of tap water, but the aspect of antibiotic resistant bacteria (ARB is not mentioned. The special emphasis is placed on the presence of pathogenic microorganisms in water, determining by the presence of chosen indicators. Although these regulations provide quite good quality of drinking water, the neglect of resistance vectors could lead to a serious threat to human health. In this study the randomly chosen sample of water from the Wroclaw water supply system was tested in order to evaluate the usefulness of Kirby-Bauer antibiogram method for the assessment of the presence of ARB. The susceptibility testing with 6 chosen antibiotics was performed on bacterial strains isolated from the sample. The diameters of growth inhibition zones were measured and the preliminary identification of strains was carried out, including Gram staining and bacterial cellular morphologies assessments. Although full recognition of the drug resistance phenomenon demands the identification of bacterial species for the comparison with susceptibility testing guidelines, this preliminary research could answer the question, whether the Kirby-Bauer method is sufficient for investigations of ARB dwelling in Wroclaw tap water or the other solution should be applied.

  8. Investigation of Fungi in Drinking Water Resources as a Source of Contamination Tap Water in Sari, Iran

    Directory of Open Access Journals (Sweden)

    Z Yousefi

    2013-06-01

    Full Text Available Background and purpose: One of the most prominent concerns for the water consumers is pathogenic microorganism contamination. Wells and underground water resources are the main resources of drinking water in Sari city, Iran. The main objectives of the research project were to explore the distribution and frequency of mycoflora in wells and underground water resources of the city and their contamination effects on humans. Materials and methods: Three reservoirs and 18 wells or underground water resources were analyzed. Water samples were then filtered and analyzed according to the World Health Organization guidelines. Each filter and 0.2 ml of suspension inoculated on SDA+CG media. For fungal growth, plates were incubated at 27’C for 7-10 days. The fungi were identified by standard mycological techniques. Results: Fungal colonies were isolated from all samples. From total of 160 fungal colonies isolated from wells water, 14 species of fungi were distinguished. Rhodotorula (54.4%, Monilinia (13.7%, Alternaria (6.9% were the most commonly isolated. Drechslera, Rhizopus, and Exserohilum (0.6% had the lowest frequency. There was no significant difference between fungal elements isolated from three major reservoirs (P>0.05. Conclusion: This study revealed that resources of drinking water from an area have to monitored and if its fungal CFU be greater than a certain value, medical and health preventive measures should be taken before the water is used by human. In this context, public and private awareness should also be provided through the media, broadcasting, teachers and scholars.

  9. Spatio-temporal variation in the tap water isotope ratios of Salt Lake City: a novel indicator of urban water system structure and dynamics.

    Science.gov (United States)

    Jameel, M. Y.; Bowen, G. J.

    2015-12-01

    Public water supply systems are the life-blood of urban areas. How we use urban water systems affects more than human health and well-being. Our water use can alter a city's energy balance, including how much solar energy is absorbed as heat or reflected back into space. The severity of these effects, and the need to better understand connections between climate, water extraction, water use, and water use impacts, is strongest in areas of climatic aridity and substantial land-use change, such as the rapidly urbanizing areas of Utah. We have gathered and analyzed stable water isotope data from a series of semi-annual hydrological surveys (spring and fall, 2013 and 2014) in urban tap water sampled across the Salt Lake Valley. Our study has led to four major findings thus far: 1) Clear and substantial variation in tap water isotopic composition in space and time that can be linked to different water sources and management practices within the urban area, 2) There is a strong correlation between the range of observed isotope values and the population of water districts, reflecting use of water from multiple local and non-local sources in districts with high water demand, 3) Water isotopes reflect significant and variable loss of water due to evaporation of surface water resources and 4) Overall, tap water contains lower concentrations of the heavy H and O isotopes than does precipitation within the basin, reflecting the connection between city water supplies and mountain water sources. Our results highlight the utility of isotopic data as an indicator of heterogeneities within urban water systems, management practices and their variation across a major metropolitan area, and effects of climate variability on urban water supplies

  10. Prokaryotic communities in drinking water biofilters using alternative filter medium

    DEFF Research Database (Denmark)

    Breda, Inês Lousinha Ribeiro; Roslev, Peter; Ramsay, Loren

    Biofilters are often the heart of drinking water treatment systems in Europe. The effect that alternative filter media may have on the microbial communities and therefore in the duration of the start-up period has received little attention. This project investigates the microbial communities...... in an alternative filter medium during the start-up of manganese removal. Filter media properties were measured using gravimetric methods and a photometric particle analyzer. Physical, chemical and microbial analyses were used to follow the manganese ripening. Microbial analyses of both inlet water and filter...

  11. Contamination of hospital tap water: the survival and persistence of Pseudomonas aeruginosa on conventional and 'antimicrobial' outlet fittings.

    Science.gov (United States)

    Hutchins, C F; Moore, G; Thompson, K-A; Webb, J; Walker, J T

    2017-10-01

    Pseudomonas aeruginosa infections have been linked to contaminated hospital taps, highlighting the potential for tap outlet fittings (OF) to harbour biofilm. P. aeruginosa may be transferred to OFs via contaminated cleaning cloths. Suggested interventions include flushing regimens and alternative OF designs. To investigate the transfer of P. aeruginosa from a contaminated cleaning cloth to conventional and 'antimicrobial/antibiofilm' OFs and to determine whether this contamination persists and/or leads to contamination of tap water. Microfibre cloths contaminated with P. aeruginosa (10 8  cfu/mL) were used to wipe four different types of OF [one of conventional design (OF-A) and three marketed as 'antimicrobial' and/or 'antibiofilm' (OF- B, -C and -D)]. OFs were inserted into an experimental water distribution system for up to 24 h. Survival was assessed by culture. Single and multiple water samples were collected and cultured for P. aeruginosa. The median number of P. aeruginosa transferred from cloth to OF was 5.7 × 10 5  cfu (OF-A), 1.9 × 10 6  cfu (OF-B), 1.4 × 10 5  cfu (OF-C) and 2.9 × 10 6  cfu (OF-D). Numbers declined on all OFs during the 24 h period with log reductions ranging from 3.5 (OF-C) to 5.2 (OF-B; P > 0.05). All water samples delivered immediately after OF contamination contained P. aeruginosa at ≥10 cfu per 100 mL. Contamination of water delivered from OF-A persisted despite continued flushing. Water delivered from OF-B did not contain P. aeruginosa beyond the first flush. Contaminated cleaning cloths may transfer P. aeruginosa to OFs, leading to contamination of tap water. Although not removing the potential for contamination, 'antimicrobial/antibiofilm' OFs may prevent P. aeruginosa from continually contaminating water delivered from the outlet. Copyright © 2017 The Healthcare Infection Society. All rights reserved.

  12. Avoiding the Use of Exhausted Drinking Water Filters: A Filter-Clock Based on Rusting Iron

    Directory of Open Access Journals (Sweden)

    Arnaud Igor Ndé-Tchoupé

    2018-05-01

    Full Text Available Efficient but affordable water treatment technologies are currently sought to solve the prevalent shortage of safe drinking water. Adsorption-based technologies are in the front-line of these efforts. Upon proper design, universally applied materials (e.g., activated carbons, bone chars, metal oxides are able to quantitatively remove inorganic and organic pollutants as well as pathogens from water. Each water filter has a defined removal capacity and must be replaced when this capacity is exhausted. Operational experience has shown that it may be difficult to convince some low-skilled users to buy new filters after a predicted service life. This communication describes the quest to develop a filter-clock to encourage all users to change their filters after the designed service life. A brief discussion on such a filter-clock based on rusting of metallic iron (Fe0 is presented. Integrating such filter-clocks in the design of water filters is regarded as essential for safeguarding public health.

  13. Whole genome and transcriptome analyses of environmental antibiotic sensitive and multi-resistant Pseudomonas aeruginosa isolates exposed to waste water and tap water.

    Science.gov (United States)

    Schwartz, Thomas; Armant, Olivier; Bretschneider, Nancy; Hahn, Alexander; Kirchen, Silke; Seifert, Martin; Dötsch, Andreas

    2015-01-01

    The fitness of sensitive and resistant Pseudomonas aeruginosa in different aquatic environments depends on genetic capacities and transcriptional regulation. Therefore, an antibiotic-sensitive isolate PA30 and a multi-resistant isolate PA49 originating from waste waters were compared via whole genome and transcriptome Illumina sequencing after exposure to municipal waste water and tap water. A number of different genomic islands (e.g. PAGIs, PAPIs) were identified in the two environmental isolates beside the highly conserved core genome. Exposure to tap water and waste water exhibited similar transcriptional impacts on several gene clusters (antibiotic and metal resistance, genetic mobile elements, efflux pumps) in both environmental P. aeruginosa isolates. The MexCD-OprJ efflux pump was overexpressed in PA49 in response to waste water. The expression of resistance genes, genetic mobile elements in PA49 was independent from the water matrix. Consistently, the antibiotic sensitive strain PA30 did not show any difference in expression of the intrinsic resistance determinants and genetic mobile elements. Thus, the exposure of both isolates to polluted waste water and oligotrophic tap water resulted in similar expression profiles of mentioned genes. However, changes in environmental milieus resulted in rather unspecific transcriptional responses than selected and stimuli-specific gene regulation. © 2014 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  14. Selective solid phase extraction of lanthanides from tap and river waters with ion imprinted polymers.

    Science.gov (United States)

    Moussa, Manel; Ndiaye, Massamba Mbacké; Pinta, Thomas; Pichon, Valérie; Vercouter, Thomas; Delaunay, Nathalie

    2017-04-22

    For the first time, an ion imprinted polymer (IIP) able to selectively extract simultaneously all the lanthanide ions was successfully synthesized in acetonitrile using Nd 3+ as a template ion, methacrylic acid as a complexing monomer, and ethylene glycol dimethacrylate as a cross-linker. A non-imprinted polymer (NIP) was synthesized under the same conditions as those of the IIP, but in the absence of the template ion. After the removal of the template ions, grounding and sieving, the IIP particles were packed in solid phase extraction (SPE) cartridges. The selectivity of the IIP was evaluated by comparing its behavior with the one of the NIP. Each SPE step (percolation, washing, and elution) was optimized in order to find the best compromise between the selectivity and the extraction recoveries. Using the optimized SPE conditions, the extraction recoveries of eight lanthanide ions representative of the lanthanide family were higher than 77% with an average value of 83% with the IIP, whereas, in the case of the NIP, they ranged between 14 and 36% and they were below 3% for the interfering ions from alkali, transition, and post-transition metal families with the IIP. A first evaluation of the reproducibility of the SPE profiles was carried out by performing statistical tests on the data obtained with several cartridges filled with particles obtained from two different IIP and NIP syntheses. Promising results were obtained. The specific capacity, i. e. the adsorption capacity of Nd 3+ ions by the specific cavities of the imprinted polymer, was about 9 mg of Nd 3+ per gram of IIP (60 μmol g -1 ), which is more than enough for the extraction of the lanthanide ions at trace levels. The breakthrough volume was about 1 mL per mg of IIP, leading to an enrichment factor of 15, which allows not only to selectively extract the lanthanides but also to concentrate them. Finally, the imprinted polymer was successfully used to selectively extract lanthanides from tap and

  15. The impact of the hot tap water load pattern in the industrial hall on the energy yield from solar collectors

    Directory of Open Access Journals (Sweden)

    Fidorów-Kaprawyl Natalia

    2017-01-01

    Full Text Available The systems using solar energy, popular in Poland, can be used to supply hot water for the installation used by employees of industrial halls. In manufacturing plants, employing a large number of people, the demand for hot water is practically constant throughout the year and is characterized by periodic use at the end of each work shift. Dynamics of the hot water consumption depends on the number of shifts as well as working days and holidays. Additionally the maximum hot tap water demand occurs in the whole period of installation operation. In polish climatic conditions the solar collectors’ systems have the largest capacity in the summer, while in winter they need to be assisted. Beside that the supply of renewable energy is uneven and depends on weather conditions. In the paper the one-hour step analysis concerning the dependence of the load pattern of the hot tap water preparation system on the energy yield from solar collectors had been performed.

  16. Investigation of Locally Made Ceramic Filter for Household Water Treatment

    Directory of Open Access Journals (Sweden)

    Awaluddin Nurmiyanto

    2012-06-01

    Full Text Available This research have objective to develop and evaluate the performance of ceramic filter in using locally available material at Yogyakarta. Ceramic filter are made by pressing a mixture of clay, discarded pottery (grog and combustible material (coconut fiber into the molder. Curving processes are then applied to form tubular shape before firing it using kiln (1005°C. Filtration test were performed gravitationally by flowing well water into ceramic filter. Filtered water quality was complying with Indonesia drinking water quality standard (E.Coli and turbidity although it has low filtration rate (0,461 L/Hr. The most optimum ceramic filter in turbidity and bacterial removal was composition number 10 {clay+coconut fiber 4,5%(w/w+grog 5%(w/w} that have average turbidity removal 88,2%, and average E. Coli removal 100%. N2 adsorption-desorption result on ceramic filter number 10 showed 0,04μm pore size, and 4,32m2/g pore surface area. The result from the XRD (X-ray diffractometer indicates crystal structure of calcite and quartz on ceramic filter surface. Energy Dispersive X-ray (EDX analysis showed Carbon compound as the most material constituent within the filter. Whereas micro’s photo using SEM (scanning electron microscopic and TEM (transmitted electron microscopic showed filter surface consists of stacked aggregates, separated by more randomly oriented particles.

  17. Occurrence of antidepressant residues in the sewage-impacted Vistula and Utrata rivers and in tap water in Warsaw (Poland).

    Science.gov (United States)

    Giebułtowicz, Joanna; Nałęcz-Jawecki, Grzegorz

    2014-06-01

    Antidepressants, even at low concentrations, can reveal some adverse effects on aquatic life due to disturbing homeostasis throughout the central and peripheral nervous system both in vertebrates and invertebrates. To date there have not been any reports regarding the presence of these pharmaceuticals in surface and tap waters in Eastern Europe. Therefore the aim of this study was to determine the presence of 21 antidepressant pharmaceuticals at specific points of the main Polish river - the Vistula, a smaller river of the Warsaw region - the Utrata, as well as in tap water samples of Warsaw. Samples were collected twice at one month intervals and analysed using solid-phase extraction (SPE) technique coupled with the liquid chromatography-electrospray ionisation-tandem mass spectrometer (LC-MS/MS) method operated under the multiple reaction monitoring mode (MRM). This is the first study where active compounds such as moclobemid or trazodone in the environment have been investigated. Environmental risk assessment of antidepressants in Poland was estimated on the basis of annuals sale data extracted from the NFZ (Narodowy Fundusz Zdrowia-National Health Service) base of reimbursed pharmaceuticals(1). Predicted environmental concentration (PEC) of target pharmaceuticals were compared with their measured concentration (MEC). Moreover, the application of the EMEA/CHMP guideline for environmental risk assessment of the antidepressants was discussed. The highest concentration of antidepressants was observed in the small river Utrata. In tap water only trace amounts of antidepressants including citalopram (up to 1.5ng/l), mianserin (up to 0.9ng/l), sertraline (water and the aquatic environment could have long-term effects even at low exposure level, especially since synergy amongst pharmaceutical pollutants may occur. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. When urban taps run dry: Sachet water consumption and health effects in low income neighborhoods of Accra, Ghana

    Science.gov (United States)

    Stoler, Justin; Fink, Günther; Weeks, John R.; Otoo, Richard Appiah; Ampofo, Joseph A.; Hill, Allan G.

    2011-01-01

    Intraurban differentials in safe drinking water in developing cities have been exacerbated by rapid population growth that exceeds expansion of local water infrastructure. In Accra, Ghana, municipal water is rationed to meet demand, and the gap in water services is increasingly being filled by private water vendors selling packaged “sachet” water. Sachets extend drinking water coverage deeper into low-income areas and alleviate the need for safe water storage, potentially introducing a health benefit over stored tap water. We explore correlates of using sachets as the primary drinking water source for 2,093 women in 37 census areas classified as slums by UN-Habitat, and links between sachet water and reported diarrhea episodes in a subset of 810 children under five. We find that neighborhood rationing exerts a strong effect on a household's likelihood of buying sachet water, and that sachet customers tend to be the poorest of the poor. Sachet use is also associated with higher levels of self-reported overall health in women, and lower likelihood of diarrhea in children. We conclude with implications for sachet regulation in Accra and other sub-Saharan cities facing drinking water shortages. PMID:22018970

  19. When urban taps run dry: sachet water consumption and health effects in low income neighborhoods of Accra, Ghana.

    Science.gov (United States)

    Stoler, Justin; Fink, Günther; Weeks, John R; Otoo, Richard Appiah; Ampofo, Joseph A; Hill, Allan G

    2012-03-01

    Intraurban differentials in safe drinking water in developing cities have been exacerbated by rapid population growth that exceeds expansion of local water infrastructure. In Accra, Ghana, municipal water is rationed to meet demand, and the gap in water services is increasingly being filled by private water vendors selling packaged "sachet" water. Sachets extend drinking water coverage deeper into low-income areas and alleviate the need for safe water storage, potentially introducing a health benefit over stored tap water. We explore correlates of using sachets as the primary drinking water source for 2093 women in 37 census areas classified as slums by UN-Habitat, and links between sachet water and reported diarrhea episodes in a subset of 810 children under five. We find that neighborhood rationing exerts a strong effect on a household's likelihood of buying sachet water, and that sachet customers tend to be the poorest of the poor. Sachet use is also associated with higher levels of self-reported overall health in women, and lower likelihood of diarrhea in children. We conclude with implications for sachet regulation in Accra and other sub-Saharan cities facing drinking water shortages. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. The first association of a primary amebic meningoencephalitis death with culturable Naegleria fowleri in tap water from a US treated public drinking water system.

    Science.gov (United States)

    Cope, Jennifer R; Ratard, Raoult C; Hill, Vincent R; Sokol, Theresa; Causey, Jonathan Jake; Yoder, Jonathan S; Mirani, Gayatri; Mull, Bonnie; Mukerjee, Kimberly A; Narayanan, Jothikumar; Doucet, Meggie; Qvarnstrom, Yvonne; Poole, Charla N; Akingbola, Olugbenga A; Ritter, Jana M; Xiong, Zhenggang; da Silva, Alexandre J; Roellig, Dawn; Van Dyke, Russell B; Stern, Harlan; Xiao, Lihua; Beach, Michael J

    2015-04-15

    Naegleria fowleri is a climate-sensitive, thermophilic ameba found in warm, freshwater lakes and rivers. Primary amebic meningoencephalitis (PAM), which is almost universally fatal, occurs when N. fowleri-containing water enters the nose, typically during swimming, and migrates to the brain via the olfactory nerve. In August 2013, a 4-year-old boy died of meningoencephalitis of unknown etiology in a Louisiana hospital. Clinical and environmental testing and a case investigation were initiated to determine the cause of death and to identify potential exposures. Based on testing of cerebrospinal fluid and brain specimens, the child was diagnosed with PAM. His only reported water exposure was tap water; in particular, tap water that was used to supply water to a lawn water slide on which the child had played extensively prior to becoming ill. Water samples were collected from both the home and the water distribution system that supplied the home and tested; N. fowleri was identified in water samples from both the home and the water distribution system. This case is the first reported PAM death associated with culturable N. fowleri in tap water from a US treated drinking water system. This case occurred in the context of an expanding geographic range for PAM beyond southern states, with recent case reports from Minnesota, Kansas, and Indiana. This case also highlights the role of adequate disinfection throughout drinking water distribution systems and the importance of maintaining vigilance when operating drinking water systems using source waters with elevated temperatures. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  1. A simple optode based imaging technique to measure O2 distribution and dynamics in tap water biofilms

    DEFF Research Database (Denmark)

    Staal, Marc Jaap; Prest, E.; Vrouwenvelder, H.

    2011-01-01

    window. The method is based on sequential imaging of the O2 dependent luminescence intensity, which are subsequently normalized with luminescent intensity images recorded under anoxic conditions. We present 2-dimensional O2 distribution images at the base of a tap water biofilm measured with the new...... ratiometric method and compare the results with O2 distribution images obtained in the same biofilm reactor with luminescence lifetime imaging. Using conventional digital cameras, such simple normalized luminescence intensity imaging can yield images of 2-dimensional O2 distributions with a high signal...

  2. Biofilm Composition and Threshold Concentration for Growth of Legionella pneumophila on Surfaces Exposed to Flowing Warm Tap Water without Disinfectant

    Science.gov (United States)

    Bakker, Geo L.; Italiaander, Ronald; Veenendaal, Harm R.; Wullings, Bart A.

    2017-01-01

    ABSTRACT Legionella pneumophila in potable water installations poses a potential health risk, but quantitative information about its replication in biofilms in relation to water quality is scarce. Therefore, biofilm formation on the surfaces of glass and chlorinated polyvinyl chloride (CPVC) in contact with tap water at 34 to 39°C was investigated under controlled hydraulic conditions in a model system inoculated with biofilm-grown L. pneumophila. The biofilm on glass (average steady-state concentration, 23 ± 9 pg ATP cm−2) exposed to treated aerobic groundwater (0.3 mg C liter−1; 1 μg assimilable organic carbon [AOC] liter−1) did not support growth of the organism, which also disappeared from the biofilm on CPVC (49 ± 9 pg ATP cm−2) after initial growth. L. pneumophila attained a level of 4.3 log CFU cm−2 in the biofilms on glass (1,055 ± 225 pg ATP cm−2) and CPVC (2,755 ± 460 pg ATP cm−2) exposed to treated anaerobic groundwater (7.9 mg C liter−1; 10 μg AOC liter−1). An elevated biofilm concentration and growth of L. pneumophila were also observed with tap water from the laboratory. The Betaproteobacteria Piscinibacter and Methyloversatilis and amoeba-resisting Alphaproteobacteria predominated in the clones and isolates retrieved from the biofilms. In the biofilms, the Legionella colony count correlated significantly with the total cell count (TCC), heterotrophic plate count, ATP concentration, and presence of Vermamoeba vermiformis. This amoeba was rarely detected at biofilm concentrations of TCC = 1 × 106 to 2 × 106 cells cm−2) was derived for growth of L. pneumophila in biofilms. IMPORTANCE Legionella pneumophila is the etiologic agent in more than 10,000 cases of Legionnaires' disease that are reported annually worldwide and in most of the drinking water-associated disease outbreaks reported in the United States. The organism proliferates in biofilms on surfaces exposed to warm water in engineered freshwater installations. An

  3. Removal method of radium in mine water by filter sand

    International Nuclear Information System (INIS)

    Taki, Tomihiro; Naganuma, Masaki

    2003-01-01

    Trace radium is contained in mine water from the old mine road in Ningyo-Toge Environmental Engineering Center, JNC. We observed that filter sand with hydrated manganese oxide adsorbed radium in the mine water safely for long time. The removal method of radium by filter sand cladding with hydrated manganese oxide was studied. The results showed that radium was removed continuously and last for a long time from mine water with sodium hypochlorite solution by passing through the filter sand cladding with hydrated manganese. Only sodium hypochlorite solution was used. When excess of it was added, residue chlorine was used as chlorine disinfection. Filter sand cladding with hydrated manganese on the market can remove radium in the mine water. The removal efficiency of radium is the same as the radium coprecipitation method added with barium chloride. The cost is much lower than the ordinary methods. Amount of waste decreased to about 1/20 of the coprecipitation method. (S.Y.)

  4. Removal of 16 pesticide residues from strawberries by washing with tap and ozone water, ultrasonic cleaning and boiling.

    Science.gov (United States)

    Lozowicka, Bozena; Jankowska, Magdalena; Hrynko, Izabela; Kaczynski, Piotr

    2016-01-01

    The effects of washing with tap and ozone water, ultrasonic cleaning and boiling on 16 pesticide (ten fungicides and six insecticides) residue levels in raw strawberries were investigated at different processing times (1, 2 and 5 min). An analysis of these pesticides was conducted using gas chromatography with nitrogen-phosphorous and electron capture detection (GC-NPD/ECD). The processing factor (PF) for each pesticide in each processing technique was determined. Washing with ozonated water was demonstrated to be more effective (reduction from 36.1 to 75.1 %) than washing with tap water (reduction from 19.8 to 68.1 %). Boiling decreased the residues of the most compounds, with reductions ranging from 42.8 to 92.9 %. Ultrasonic cleaning lowered residues for all analysed pesticides with removal of up to 91.2 %. The data indicated that ultrasonic cleaning and boiling were the most effective treatments for the reduction of 16 pesticide residues in raw strawberries, resulting in a lower health risk exposure. Calculated PFs for alpha-cypermethrin were used to perform an acute risk assessment of dietary exposure. To investigate the relationship between the levels of 16 pesticides in strawberry samples and their physicochemical properties, a principal component analysis (PCA) was performed. Graphical abstract ᅟ.

  5. Multiresidue determination of UV filters in water samples by solid-phase extraction and liquid chromatography with tandem mass spectrometry analysis.

    Science.gov (United States)

    Capriotti, Anna Laura; Cavaliere, Chiara; Piovesana, Susy; Samperi, Roberto; Stampachiacchiere, Serena; Ventura, Salvatore; Laganà, Aldo

    2014-10-01

    UV filters, contained in sunscreens and other cosmetic products, as well as in some plastics and industrial products, are nowadays considered contaminants of emerging concern because their widespread and increasing use has lead to their presence in the environment. Furthermore, some UV filters are suspected to have endocrine disruption activity. In the present work, we developed an analytical method based on liquid chromatography with tandem mass spectrometry for the determination of UV filters in tap and lake waters. Sixteen UV filters were extracted from water samples by solid-phase extraction employing graphitized carbon black as adsorbent material. Handling 200 mL of water sample, satisfactory recoveries were obtained for almost all the analytes. The limits of detection and quantification of the method were comparable to those reported in other works, and ranged between 0.7-3.5 and 1.9-11.8 ng/L, respectively; however in our case the number of investigated compounds was larger. The major encountered problem in method development was to identify the background contamination sources and reduce their contribution. UV filters were not detected in tap water samples, whereas the analyses conducted on samples collected from three different lakes showed that the swimming areas are most subject to UV filter contamination. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. An Evaluation of Microbial and Chemical Contamination Sources Related to the Deterioration of Tap Water Quality in the Household Water Supply System

    Directory of Open Access Journals (Sweden)

    Yoonjin Lee

    2013-09-01

    Full Text Available The predominant microorganisms in samples taken from shower heads in residences in the Korean city “N” were Stenotrophomonas maltophilia, Sphingomonas paucimobilis, Acidovorax temperans, and Microbacterium lacticum. Legionella was not detected in this case. The volatile organic compounds (VOCs vinylacetate, NN-DMA, cis-1,2-dichloroethylene, epichlorohydrin, and styrene were measured in five types of plastic pipes: PVC, PB, PP, PE, and cPVC. The rate of multiplication of the heterotrophic plate count (HPC attached on the copper pipe in contact with hot tap water was higher than the rate for the copper pipe in contact with cold tap water. Biofilm accumulation on stainless steel pipes with added acetate (3 mg/L was 2.56 times higher than the non-supplemented condition. Therefore, the growth of HPC in the pipe system was affected by the type and availability of nutrients and depended on variables such as heating during the hot water supply.

  7. An Evaluation of Microbial and Chemical Contamination Sources Related to the Deterioration of Tap Water Quality in the Household Water Supply System

    Science.gov (United States)

    Lee, Yoonjin

    2013-01-01

    The predominant microorganisms in samples taken from shower heads in residences in the Korean city “N” were Stenotrophomonas maltophilia, Sphingomonas paucimobilis, Acidovorax temperans, and Microbacterium lacticum. Legionella was not detected in this case. The volatile organic compounds (VOCs) vinylacetate, NN-DMA, cis-1,2-dichloroethylene, epichlorohydrin, and styrene were measured in five types of plastic pipes: PVC, PB, PP, PE, and cPVC. The rate of multiplication of the heterotrophic plate count (HPC) attached on the copper pipe in contact with hot tap water was higher than the rate for the copper pipe in contact with cold tap water. Biofilm accumulation on stainless steel pipes with added acetate (3 mg/L) was 2.56 times higher than the non-supplemented condition. Therefore, the growth of HPC in the pipe system was affected by the type and availability of nutrients and depended on variables such as heating during the hot water supply. PMID:24018837

  8. An evaluation of microbial and chemical contamination sources related to the deterioration of tap water quality in the household water supply system.

    Science.gov (United States)

    Lee, Yoonjin

    2013-09-06

    The predominant microorganisms in samples taken from shower heads in residences in the Korean city "N" were Stenotrophomonas maltophilia, Sphingomonas paucimobilis, Acidovorax temperans, and Microbacterium lacticum. Legionella was not detected in this case. The volatile organic compounds (VOCs) vinylacetate, NN-DMA, cis-1,2-dichloroethylene, epichlorohydrin, and styrene were measured in five types of plastic pipes: PVC, PB, PP, PE, and cPVC. The rate of multiplication of the heterotrophic plate count (HPC) attached on the copper pipe in contact with hot tap water was higher than the rate for the copper pipe in contact with cold tap water. Biofilm accumulation on stainless steel pipes with added acetate (3 mg/L) was 2.56 times higher than the non-supplemented condition. Therefore, the growth of HPC in the pipe system was affected by the type and availability of nutrients and depended on variables such as heating during the hot water supply.

  9. Detection of trace levels of Pb2+ in tap water at boron-doped diamond electrodes with anodic stripping voltammetry

    International Nuclear Information System (INIS)

    Dragoe, Diana; Spataru, Nicolae; Kawasaki, Ryuji; Manivannan, Ayyakkannu; Spataru, Tanta; Tryk, Donald A.; Fujishima, Akira

    2006-01-01

    Boron-doped diamond (BDD) electrodes were used to investigate the possibility of detecting trace levels of lead by linear-sweep anodic stripping voltammetry. The low limit of detection (2 nM) is an advantage compared to other electrode materials, and it was found that at low pH values, copper concentrations that are usually present in drinking water do not affect to a large extent the detection of lead. These findings recommend anodic stripping voltammetry at the BDD electrodes as a suitable mercury-free method for the determination of trace levels of lead in drinking water. The results obtained for the lead detection in tap water real samples are in excellent agreement with those found by inductively coupled plasma-mass spectrometry (ICP-MS), demonstrating the practical analytical utility of the method

  10. Synthesis and characterization of triazole based supramolecule for interaction with cefuroxime in tap water and blood plasma.

    Science.gov (United States)

    Ahmed, Farid; Perveen, Samina; Shah, Kiramat; Shah, Muhammad Raza; Ahmed, Shakil

    2018-01-01

    In this study a new calix[4]arene triazole 5 was successfully synthesized using click reaction and characterized through UV-visible, FT-IR, 1 H NMR spectroscopes and Mass Spectrometry. The supramolecular interaction of compound 5 towards commonly used drugs has been carried out using UV-Visible spectroscopy. The supramolecule 5 showed characteristic enhancement in the absorbance intensity after mixing with Cefuroxime at pH (2-12). Compound 5 displayed considerably good interactions with cefuroxime in the presence of other drugs. Compound 5 exhibits linear relationship with cefuroxime concentration in the range of (10-80µM) with regression value of 0.9954. The standard deviation for 50µM Cefuroxime was found to be 0.01 and the limit of detection for cefuroxime was calculated to be 2µM. Job's plot experiments showed 1:1 (5: cefuroxime) binding stoichiometry between compound 5 and cefuroxime. Supramolecule 5 displayed fairly good spectrophotometric recognition of Cefuroxime in human blood plasma and tap water thus showing that the ingredients of tap water and plasma sample was inert in the recognition of cefuroxime. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Filters for purification of drinking water from 134,137Cs, 89,90 Sr, 60Co: Experience of Chernobyl

    International Nuclear Information System (INIS)

    Khaydarov, R.A.; Gapurova, O.U.; Khaydarov, R.R.; Ochilov, O.

    2004-01-01

    Full text: The most probable and dangerous radionuclides which can appear in waste water of atomic power stations after accidents or terrorist acts are 134 , 137 Cs, 90 Sr, 1 29 I. Moreover, the radionuclides 137 Cs, 90 Sr and 60 Co are also most attractive for terrorists to use in dirty bombs. As a result of the disasters the radionuclides can contaminate drinking water. Generally a tap water is decontaminated at water supply stations. Nevertheless it is very important to have sorbents and household drinking water filters in stocks to prevent panic of populace and consequences of emergency cases at the water supply stations. As the concentration of Na + , K + , Ca 2+ , Mg 2+ , Cl - ions in potable water can have the value of 100 - 500 mg/l and the concentration of radionuclides is very low, the sorbents must have high selectivity and distribution coefficient of Cs + , Sr 2+ , Co 2+ , I - ions. Unfortunately most of known resins cannot be used for these purposes. Created technology of producing cationic and anionic exchange fibroid sorbents on the base of polyacrylonitrile fibers is described in the paper. Chemical characteristics of the sorbent and filters were investigated. The static exchange capacity is 3-4 meq/g for cationic sorbents and 1-2 meq/g for anionic sorbents. The removal coefficient of listed radionuclides from drinking water by filter is 102 - 103. After Chernobyl accident Academy of Sciences and KGB of Ukraine tested the household filters with fibroid sorbents and ten thousands filters were produced in the Institute of Nuclear Physics of Uzbekistan and given to Ukraine through 'Isotope' Corp. (USSR). The experience of using the filters for purification of drinking water from radionuclides in Chernobyl region is described in the paper. High technical and chemical characteristics of the sorbents have been confirmed by tests in certified labs of Germany, USA, Korea, India and Russia

  12. Human exposure to thallium through tap water: A study from Valdicastello Carducci and Pietrasanta (northern Tuscany, Italy).

    Science.gov (United States)

    Campanella, Beatrice; Onor, Massimo; D'Ulivo, Alessandro; Giannecchini, Roberto; D'Orazio, Massimo; Petrini, Riccardo; Bramanti, Emilia

    2016-04-01

    A geological study evidenced the presence of thallium (Tl) at concentrations of concern in groundwaters near Valdicastello Carducci (Tuscany, Italy). The source of contamination has been identified in the Tl-bearing pyrite ores occurring in the abandoned mining sites of the area. The strongly acidic internal waters flowing in the mining tunnels can reach exceptional Tl concentrations, up to 9000μg/L. In September 2014 Tl contamination was also found in the tap water distributed in the same area (from 2 to 10μg/L). On October 3, 2014 the local authorities imposed a Do Not Drink order to the population. Here we report the results of the exposure study carried out from October 2014 to October 2015, and aimed at quantifying Tl levels in 150 urine and 318 hair samples from the population of Valdicastello Carducci and Pietrasanta. Thallium was quantified by inductively coupled plasma - mass spectrometry (ICP-MS). Urine and hair were chosen as model matrices indicative of different time periods of exposure (short-term and long-term, respectively). Thallium values found in biological samples were correlated with Tl concentrations found in tap water in the living area of each citizen, and with his/her habits. Thallium concentration range found in hair and urine was 1-498ng/g (values in unexposed subjects 0.1-6ng/g) and 0.046-5.44μg/L (reference value for the European population 0.006μg/L), respectively. Results show that Tl levels in biological samples were significantly associated with residency in zones containing elevated water Tl levels. The kinetics of decay of Tl concentration in urine samples was also investigated. At the best of our knowledge, this is the first study on human contamination by Tl through water involving such a high number of samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. A Simple Slow-Sand Filter for Drinking Water Purification

    Directory of Open Access Journals (Sweden)

    K. O. Yusuf

    2017-04-01

    Full Text Available Water-borne diseases are commonly encountered when pathogen-contaminated water is consumed. In rural areas, water is usually obtained from ponds, open shallow wells, streams and rain water during rainy season. Rain water is often contaminated by pathogens due to unhygienic of physical and chemical conditions of the roofs thereby making it unsafe for consumption. A simple slow sand filter mechanism was designed and fabricated for purification of water in rural areas where electricity is not available to power water purification devices. Rain water samples were collected from aluminum roof, galvanized roof and thatched roof. The waters samples were allowed to flow through the slow sand filter. The values of turbidity, total dissolved solids, calcium, nitrite, faecal coliform and total coliform from unfiltered water through thatched roof were 0.92 NTU, 27.23 mg/l, 6 mg/l, 0.16 mg/l, 5cfu/100ml and 6.0 cfu/100ml, respectively while the corresponding values for slow sand filter from thatched roof were 0.01 NTU, 0.23 mg/l, 2.5 mg/l, 0.1 mg/l, 0 cfu/100ml and 0 cfu/100ml, respectively. The values of turbidity, total dissolved solid, nitrite, calcium, faecal coliform and total coliform from unfiltered water for aluminum roof were 0.82 NTU, 23.68 mg/l, 2.70 mg/l, 1.0 mg/l, 4 cfu/100ml and 4cfu/100ml, respectively while the corresponding values for slow sand filter were 0.01 NTU, 0.16 mg/l, 0.57 mg/l, 0.2 mg/l, 0 cfu/100ml and 0 cfu/100ml, respectively. The values obtained for galvanized roof were also satisfactory. The slow sand filter is recommended for used in rural areas for water purification to prevent risk of water-borne diseases.

  14. Application of a Low Cost Ceramic Filter for Recycling Sand Filter Backwash Water

    Directory of Open Access Journals (Sweden)

    Md Shafiquzzaman

    2018-02-01

    Full Text Available The aim of this study is to examine the application of a low cost ceramic filter for the treatment of sand filter backwash water (SFBW. The treatment process is comprised of pre-coagulation of SFBW with aluminum sulfate (Alum followed by continuous filtration usinga low cost ceramic filter at different trans-membrane pressures (TMPs. Jar test results showed that 20 mg/L of alum is the optimum dose for maximum removal of turbidity, Fe, and Mn from SFBW. The filter can be operated at a TMP between 0.6 and 3 kPa as well as a corresponding flux of 480–2000 L/m2/d without any flux declination. Significant removal, up to 99%, was observed forturbidity, iron (Fe, and manganese (Mn. The flux started to decline at 4.5 kPa TMP (corresponding flux 3280 L/m2/d, thus indicated fouling of the filter. The complete pore blocking model was found as the most appropriate model to explain the insight mechanism of flux decline. The optimum operating pressure and the permeate flux were found to be 3 kPa and 2000 L/m2/d, respectively. Treated SFBW by a low cost ceramic filter was found to be suitable to recycle back to the water treatment plant. The ceramic filtration process would be a low cost and efficient option to recycle the SFBW.

  15. Stable hydrogen and oxygen isotopes of tap water reveal structure of the San Francisco Bay Area's water system and adjustments during a major drought.

    Science.gov (United States)

    Tipple, Brett J; Jameel, Yusuf; Chau, Thuan H; Mancuso, Christy J; Bowen, Gabriel J; Dufour, Alexis; Chesson, Lesley A; Ehleringer, James R

    2017-08-01

    Water availability and sustainability in the Western United States is a major flashpoint among expanding communities, growing industries, and productive agricultural lands. This issue came to a head in 2015 in the State of California, when the State mandated a 25% reduction in urban water use following a multi-year drought that significantly depleted water resources. Water demands and challenges in supplying water are only expected to intensify as climate perturbations, such as the 2012-2015 California Drought, become more common. As a consequence, there is an increased need to understand linkages between urban centers, water transport and usage, and the impacts of climate change on water resources. To assess if stable hydrogen and oxygen isotope ratios could increase the understanding of these relationships within a megalopolis in the Western United States, we collected and analyzed 723 tap waters across the San Francisco Bay Area during seven collection campaigns spanning 21 months during 2013-2015. The San Francisco Bay Area was selected as it has well-characterized water management strategies and the 2012-2105 California Drought dramatically affected its water resources. Consistent with known water management strategies and previously collected isotope data, we found large spatiotemporal variations in the δ 2 H and δ 18 O values of tap waters within the Bay Area. This is indicative of complex water transport systems and varying municipality-scale management decisions. We observed δ 2 H and δ 18 O values of tap water consistent with waters originating from snowmelt from the Sierra Nevada Mountains, local precipitation, ground water, and partially evaporated reservoir sources. A cluster analysis of the isotope data collected in this study grouped waters from 43 static sampling sites that were associated with specific water utility providers within the San Francisco Bay Area and known management practices. Various management responses to the drought, such as

  16. Characterization of large area ZnS(Ag) detector for gross alpha and beta activity measurements in tap water plants

    Energy Technology Data Exchange (ETDEWEB)

    Lunardon, M.; Cester, D.; Mistura, G.; Moretto, S.; Stevanato, L.; Viesti, G. [Department of Physics and Astronomy ' Galileo Galilei' , University of Padova, (Italy); Schotanus, P.; Bodewits, E. [SCIONIX Holland BV, (Netherlands)

    2015-07-01

    In this work we present the characterization of a large area 200 x 200 mm{sup 2} EJ-444 scintillation detector to be used for monitoring gross alpha and beta activity in tap water plants. Specific tests were performed to determine the best setup to readout the light from the detector side in order to have the possibility to stack many detectors and get a compact device with total active area of the order of 1 m{sup 2}. Alpha/Beta discrimination, efficiency and homogeneity tests were carried out with alpha and beta sources. Background from ambient radioactivity was measured as well. Alpha/beta real-time monitoring in drinking water is a goal of the EU project TAWARA{sub R}TM. (authors)

  17. Mobility of fertiliser-derived uranium in arable soils and its contribution to uranium concentrations in groundwater and tap water

    International Nuclear Information System (INIS)

    Smidt, Geerd Ahlrich

    2011-01-01

    Phosphorus (P) mineral fertilisers are found to contain high concentrations of uranium (U) (up to 206 mg U kg -1 ) and other trace elements (TE), such as Cd, Pb, Ni, Cu, Zn, Th, Nb, Sr, V, and rare earth elements. The content of U and other trace elements is depended on the sedimentary of igneous origin of the rock phosphate. In this study, the production of P fertilisers has been shown to contaminate top soil horizons with U and other trace elements in the close vicinity of a factory located in Southern Brazil. In contrast to this point source, agricultural P fertilisation leads to a diffuse contamination of the agro-ecosystem with U and other fertiliser-derived trace elements on a large scale. Top soil horizons of arable land accumulate fertiliser-derived U. According to the geochemical behaviour of U(VI) species under oxidising conditions, the mobilisation capacity for U in top soil horizons is considered to be high, contrary to other fertiliser-derived heavy metals (e.g. Cd). Hence, it is assumed that U can be leached to shallow groundwater and can reach fresh water resources potentially used for drinking water supply. The aims of this study were to investigate the concentration of U and other contaminants in P fertilisers, to identify geochemical processes of fertiliser-derived U mobility and mobilisation from arable top soil horizons to the groundwater, and to evaluate the origin of U in German groundwater and tap water. This study presents the broadest recent data set on regional distribution of U concentrations in German tap water to which 76 % of the German population has access. The mean U concentration was 0.68 μg L -1 , the median 0.50 μg L -1 . 1.3 % or 1 million of the 80.6 million inhabitants in Germany are exposed to U concentrations in tap water which are higher than the German drinking water threshold limit of 10 μg L -1 . The regional distribution of U concentrations largely agrees with the geological setting reported for mineral waters

  18. Copper concentrations in tap water and possible effects on infant's health - Results of a study in Lower Saxony, Germany

    International Nuclear Information System (INIS)

    Zietz, B.P.; Dassel de Vergara, Julia; Dunkelberg, Hartmut

    2003-01-01

    Copper in drinking water has been associated with non-Indian childhood cirrhosis (NICC), a form of liver cirrhosis in childhood. This epidemiological study examines the exposure of infants to increased copper concentrations through drinking water from public water supplies in southern Lower Saxony, Germany, and whether this dietary copper intake causes liver damage in early childhood. In total, water samples from 1674 households with infants were tested for copper. The mean copper concentration was 0.18 mg/L in the 1619 collected stagnation samples and 0.11 mg/L in the 1660 random daytime samples. There were notable regional differences in copper values. In 10.3% of all sampled households a copper value of 0.5 mg/L or more was found. These families were requested to additionally collect 2 composite samples. An increased level of copper in the drinking water with copper concentrations at or above 0.8 mg/L in the composite samples and a defined minimum ingestion of tap water was followed by a recommendation of a pediatric examination. Fourteen infants were examined by a pediatrician and of these 11 received a blood serum analysis. None of the examined infants showed any signs of liver malfunction. From the results of the study, no indication of a hazard due to copper pipes connected to public water supplies could be found

  19. Relationship between tap water hardness, magnesium, and calcium concentration and mortality due to ischemic heart disease or stroke in the Netherlands

    NARCIS (Netherlands)

    Leurs, L.J.; Schouten, L.J.; Mons, M.N.; Goldbohm, R.A.; Brandt, P.A. van den

    2010-01-01

    BACKGROUND: Conflicting results on the relationship between the hardness of drinking water and mortality related to ischemic heart disease (IHD) or stroke have been reported. OBJECTIVES: We investigated the possible association between tap water calcium or magnesium concentration and total hardness

  20. Physics on Tap

    Science.gov (United States)

    Wheeler, Andrew P. S.

    2012-01-01

    This article aims to describe how to visualize surface tension effects in liquid jets. A simple experiment is proposed using the liquid jet flow from a mains water tap/faucet. Using a modern digital camera with a high shutter speed, it is possible to visualize the instabilities (capillary waves) that form within the jet due to the action of…

  1. Plasma-activation of tap water using DBD for agronomy applications: Identification and quantification of long lifetime chemical species and production/consumption mechanisms.

    Science.gov (United States)

    Judée, F; Simon, S; Bailly, C; Dufour, T

    2018-04-15

    Cold atmospheric plasmas are weakly ionized gases that can be generated in ambient air. They produce energetic species (e.g. electrons, metastables) as well as reactive oxygen species, reactive nitrogen species, UV radiations and local electric field. Their interaction with a liquid such as tap water can hence change its chemical composition. The resulting "plasma-activated liquid" can meet many applications, including medicine and agriculture. Consequently, a complete experimental set of analytical techniques dedicated to the characterization of long lifetime chemical species has been implemented to characterize tap water treated using cold atmospheric plasma process and intended to agronomy applications. For that purpose, colorimetry and acid titrations are performed, considering acid-base equilibria, pH and temperature variations induced during plasma activation. 16 species are quantified and monitored: hydroxide and hydronium ions, ammonia and ammonium ions, orthophosphates, carbonate ions, nitrite and nitrate ions and hydrogen peroxide. The related consumption/production mechanisms are discussed. In parallel, a chemical model of electrical conductivity based on Kohlrausch's law has been developed to simulate the electrical conductivity of the plasma-activated tap water (PATW). Comparing its predictions with experimental measurements leads to a narrow fitting, hence supporting the self-sufficiency of the experimental set, I.e. the fact that all long lifetime radicals of interest present in PATW are characterized. Finally, to evaluate the potential of cold atmospheric plasmas for agriculture applications, tap water has been daily plasma-treated to irrigate lentils seeds. Then, seedlings lengths have been measured and compared with untreated tap water, showing an increase as high as 34.0% and 128.4% after 3 days and 6 days of activation respectively. The interaction mechanisms between plasma and tap water are discussed as well as their positive synergy on

  2. Arsenic removal for ceramic water filters

    Directory of Open Access Journals (Sweden)

    Mishant Kumar

    2013-02-01

    Full Text Available Arsenic in drinking water is a hazard to human health and is a known carcinogen (Mass 1992. Resource Development International – Cambodia (RDIC has researched, developed, and manufactured simple ceramic water fi lters (CWF which have proved to be extremely effective in removing pathogens from water. These fi lters however, do not remove arsenic from water, which exists in the source water at levels above the World Health Organisation (WHO guideline of 10μg/L. The aims of this literature based study were to investigate conventional and non-conventional arsenic removal processes, and to discuss the options for applying an arsenic removal technology to the CWFs produced by RDIC. It was found that conventional arsenic removal technologies are diffi cult to implement in the context of household water treatment in a developing country. This study suggested that non-conventional arsenic removal technologies shall be more effective and that field studies must be undertaken to verify the success of such methods.

  3. De novo biofilm community assembly from tap water source communities favors Nitrotoga over Nitrospira under elevated nitrite surface loading

    DEFF Research Database (Denmark)

    Kinnunen, Marta; Dechesne, Arnaud; Albrechtsen, Hans-Jørgen

    -through biofilm system to continuous immigration from a tap water metacommunity while applying different nitrite surface loading rates. After 63 days of operation, we extracted biofilms and analyzed the community composition via Illumina MiSeq targeting the 16S rRNA gene. Previous studies have shown...... in the metacommunity, Nitrotoga and Nitrospira were found at near equal abundances, in the biofilm community, elevated nitrite loading strongly selected for Nitrotoga over Nitrospira. The biofilms were also significantly different in their alpha-diversity (p... of the biofilm community decreased significantly (p=0.004) compared to the metacommunity. These observations indicate that the selection towards Nitrotoga and Nitrospira dominated community assembly under different nitrite loadings. Lastly, we compared our observations of community composition...

  4. Biofilm Composition and Threshold Concentration for Growth of Legionella pneumophila on Surfaces Exposed to Flowing Warm Tap Water without Disinfectant.

    Science.gov (United States)

    van der Kooij, Dick; Bakker, Geo L; Italiaander, Ronald; Veenendaal, Harm R; Wullings, Bart A

    2017-03-01

    Legionella pneumophila in potable water installations poses a potential health risk, but quantitative information about its replication in biofilms in relation to water quality is scarce. Therefore, biofilm formation on the surfaces of glass and chlorinated polyvinyl chloride (CPVC) in contact with tap water at 34 to 39°C was investigated under controlled hydraulic conditions in a model system inoculated with biofilm-grown L. pneumophila The biofilm on glass (average steady-state concentration, 23 ± 9 pg ATP cm -2 ) exposed to treated aerobic groundwater (0.3 mg C liter -1 ; 1 μg assimilable organic carbon [AOC] liter -1 ) did not support growth of the organism, which also disappeared from the biofilm on CPVC (49 ± 9 pg ATP cm -2 ) after initial growth. L. pneumophila attained a level of 4.3 log CFU cm -2 in the biofilms on glass (1,055 ± 225 pg ATP cm -2 ) and CPVC (2,755 ± 460 pg ATP cm -2 ) exposed to treated anaerobic groundwater (7.9 mg C liter -1 ; 10 μg AOC liter -1 ). An elevated biofilm concentration and growth of L. pneumophila were also observed with tap water from the laboratory. The Betaproteobacteria Piscinibacter and Methyloversatilis and amoeba-resisting Alphaproteobacteria predominated in the clones and isolates retrieved from the biofilms. In the biofilms, the Legionella colony count correlated significantly with the total cell count (TCC), heterotrophic plate count, ATP concentration, and presence of Vermamoeba vermiformis This amoeba was rarely detected at biofilm concentrations of <100 pg ATP cm -2 A threshold concentration of approximately 50 pg ATP cm -2 (TCC = 1 × 10 6 to 2 × 10 6 cells cm -2 ) was derived for growth of L. pneumophila in biofilms. IMPORTANCE Legionella pneumophila is the etiologic agent in more than 10,000 cases of Legionnaires' disease that are reported annually worldwide and in most of the drinking water-associated disease outbreaks reported in the United States. The organism proliferates in biofilms on surfaces

  5. Correlation among the terrestrial gamma radiation, the indoor air 222Rn, and the tap water 222Rn in Switzerland

    International Nuclear Information System (INIS)

    Buchli, R.; Burkart, W.

    1989-01-01

    The external gamma radiation and the indoor air Rn (222Rn) concentration were measured in 55 houses of the South East Grisons, the Urseren valley, and the Upper Rhine valley (crystalline subsoils) and in 39 houses of the Molasse basin and the Helvetic nappes (sedimentary subsoils). In homes located on a crystalline subsoil, a mean cellar gamma level of 1.40 mGy y-1 was measured, which is twice the mean gamma level of 0.70 mGy y-1 found in homes built on a sedimentary subsoil. The cellar 222Rn gas concentration is about six times higher in houses with a crystalline subsoil (1232 Bq m-3) than in houses with a sedimentary subsoil (201 Bq m-3). Although a weak correlation is observed between the mean gamma radiation levels and mean cellar 222Rn gas concentrations for the five subregions investigated, the gamma levels and the 222Rn gas concentrations do not correlate for single homes. For the population living on the ground floor of a house with a crystalline subsoil, the gamma radiation and the indoor air 222Rn lead to estimated mean exposures of 1.16 mSv and 9.44 mSv effective dose equivalent per year, respectively. In houses with a sedimentary subsoil, these mean exposures lead to 0.68 mSv y-1 and 3.22 mSv y-1, respectively. A mean tap water 222Rn content of 38.3 Bq L-1 and 10.4 Bq L-1 was measured in 31 villages with a crystalline subsoil and 73 villages with a sedimentary subsoil, respectively. Radon-222 degasing from the tap water into the indoor air leads to an additional exposure of about 0.11 mSv y-1 and 0.03 mSv y-1 in homes with a crystalline subsoil and homes with a sedimentary subsoil, respectively

  6. A City-wide Investigation of the Isotopic Distribution and Source of Tap Waters for Forensic Human Geolocation Ground-truthing.

    Science.gov (United States)

    Ueda, Momoko; Bell, Lynne S

    2017-05-01

    Human geolocation is prefaced on the accuracy of the geographic precision of mapped isotopic values for drinking water. As most people live in cities, it becomes important to understand city water supplies and how the isotopic values uniquely reflect that city. This study investigated the isotopic distribution of δ 2 H and δ 18 O from sourced tap waters that were collected from across the Metro Vancouver (MV) area (n = 135). The results revealed that the isotopic values reflect their water sources with a range of 5.3‰ for δ 18 O tap and 29.3‰ for δ 2 H tap for MV. The results indicate that individual cities need higher resolution studies to determine their tap water isotopic ranges, and a good understanding of the water supply network itself for human geolocation work. With an extended high-resolution understanding of each city, human tissue may be compared with more certainty for geolocation. © 2016 American Academy of Forensic Sciences.

  7. Application of Self Cleaning Rapid Sand Filter in Water Treatment

    Directory of Open Access Journals (Sweden)

    Ali Reza Rahmani

    2005-08-01

    Full Text Available Rapid sand filter is one of the most important units in the water treatment plants. It has some difficulties in operation such as backwashing. For the solving of this problem a rapid sand filter has designed and built with the self-cleaning backwashing system. This system consist of 3 main constituents; one galvanized siphon and two galvanized steel tanks. One of them is used for filtration and the other used for the storage of filtrated water in elevation for backwashing the system. Water enter from upside of the filter through the inlet pipe, and collected from the under drainage pipe. Then filter water conduct to the storage tank and exit from outlet pipe. In the beginning, the head loss was low, but because of bed clogging by suspended solids, it increases gradually to the designed head loss (1.2m. Then the system is outed of the service automatically and the backwash is began. The main data for the design of system selected from the hydraulic rules of siphons and rapid sand filter criteria. After essential calculations it was constructed and was started operation. For the hydraulic studies a known volume of storage tank was selected and the time needed for the fill (in filtration stage and empty (in backwash stage of water volume with volumetric method were measured. In hydraulic studies the filter surface rate (SOR was selected about 5-7.5m3/m2/hr (1.39-2.08 lit/sec and the flow of water in siphon, during the backwashing was measured 8.7 lit/sec. It can be seen that the siphon passes 4-6 times the inlet raw water thus a negative pressure will created in the siphon which causes the water above the sand bed to be discharged automatically and rinse water from elevated tank flow under the sand bed and back wash it. So according to this study self cleaning rapid sand filter is very useful for water filtration, especially in small population community. The construction of system is rapid, simple and economic.

  8. Dynamic graphene filters for selective gas-water-oil separation.

    Science.gov (United States)

    Bong, Jihye; Lim, Taekyung; Seo, Keumyoung; Kwon, Cho-Ah; Park, Ju Hyun; Kwak, Sang Kyu; Ju, Sanghyun

    2015-09-23

    Selective filtration of gas, water, and liquid or gaseous oil is essential to prevent possible environmental pollution and machine/facility malfunction in oil-based industries. Novel materials and structures able to selectively and efficiently filter liquid and vapor in various types of solutions are therefore in continuous demand. Here, we investigate selective gas-water-oil filtration using three-dimensional graphene structures. The proposed approach is based on the adjustable wettability of three-dimensional graphene foams. Three such structures are developed in this study; the first allows gas, oil, and water to pass, the second blocks water only, and the third is exclusively permeable to gas. In addition, the ability of three-dimensional graphene structures with a self-assembled monolayer to selectively filter oil is demonstrated. This methodology has numerous potential practical applications as gas, water, and/or oil filtration is an essential component of many industries.

  9. Molecular characterization of natural biofilms from household taps with different materials: PVC, stainless steel, and cast iron in drinking water distribution system.

    Science.gov (United States)

    Lin, Wenfang; Yu, Zhisheng; Chen, Xi; Liu, Ruyin; Zhang, Hongxun

    2013-09-01

    Microorganism in drinking water distribution system may colonize in biofilms. Bacterial 16S rRNA gene diversities were analyzed in both water and biofilms grown on taps with three different materials (polyvinyl chloride (PVC), stainless steel, and cast iron) from a local drinking water distribution system. In total, five clone libraries (440 sequences) were obtained. The taxonomic composition of the microbial communities was found to be dominated by members of Proteobacteria (65.9-98.9 %), broadly distributed among the classes Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria. Other bacterial groups included Firmicutes, Acidobacteria, Bacteroidetes, Cyanobacteria, and Deinococcus-Thermus. Moreover, a small proportion of unclassified bacteria (3.5-10.6 %) were also found. This investigation revealed that the bacterial communities in biofilms appeared much more diversified than expected and more care should be taken to the taps with high bacterial diversity. Also, regular monitor of outflow water would be useful as potentially pathogenic bacteria were detected. In addition, microbial richness and diversity in taps ranked in the order as: PVC cast iron. All the results interpreted that PVC would be a potentially suitable material for use as tap component in drinking water distribution system.

  10. Treatment of residual waters of slaughterhouses with filters

    International Nuclear Information System (INIS)

    Ortiz A, Jesus Mario

    1995-01-01

    For studying the anaerobic treatment of the residual waters coming from a slaughterhouse of bovine livestock, they were used a system of two filters in series and a third unique filter as witness. With values average of load organic volumetric and time of retention of 1.6 kg/(m 3 d) and 26 hours respectively, the efficiencies of removal of total DQO were similar in the unique filter and in the system in series, of the order of 64% on the average. Likewise, the retention and accumulation of biological solids in the channel were shown as the main road of removal of the DQO. The differentiation of the process achieved with the two filters in series allowed establishing that most of the accumulation happened in the primary filter, as long as the fundamental of the bioconversion in methane took place in the secondary filter of the system in series. The first relative level of methanegenization obtained could be explained by the limitations to the activity of the methanogenic biomass imposed by the low temperatures, although it could not discard a probable inhibition for the hydrolysis products of the accumulated fats

  11. performance of water filters towards the removal of selected

    African Journals Online (AJOL)

    Morohani Merinyo

    rights. Only 80% of urban and 47.9% of rural dwellers in Tanzania have access to improved water sources according to. Tanzania Demographic and Health Survey ..... Nordin D, Baker and Mazumder. A 2006 The use and performance of Bio-. Sand filters in the Artibonite Valley of. Haiti: a field of 107 households. Rural.

  12. Rural water safety from the source to the on-farm tap.

    Science.gov (United States)

    Corkal, Darrell; Schutzman, W C; Hilliard, Clint

    For those Canadians who live in metropolitan areas, good quality water for domestic use and consumption is readily available, and perhaps taken for granted. However, for over 4 million Canadians who rely on private water supplies, access to water that is safe for consumption and suitable for domestic use is a very real issue. This is also true in the agriculture and agri-food sector. Many of these private water supplies are in rural areas, where water is taken from surface or ground sources. These supplies may be of naturally poor quality, or may have had their quality affected by municipal, industrial, or agricultural activities. Options to protect and enhance the quality of private water supplies include source protection using best management practices (BMPs), source enhancement, and water treatment using innovative small-scale systems. With funding from the Canada-Saskatchewan Agri-Food Innovation Fund, Agriculture and Agri-Food Canada has conducted applied research into effective and affordable BMPs (remote livestock watering, low-drift nozzles for spraying farm chemicals, methods to reduce agro-chemical runoff or leaching, etc.). Source enhancement strategies were studied using aeration for farm ponds or preventive maintenance procedures for ground water wells. Various water treatment technologies were adapted to the small-scale needs of farms, including coagulation, biological sand and biological carbon filtration, membrane filtration using microfilters, nanofilters or reverse osmosis processes, and disinfection systems using chlorination or ultra violet light. Each research project included a technology transfer component, to ensure that the knowledge gained from the research was available to those that needed the information, and to help decision makers address rural water quality problems.

  13. Dynamic graphene filters for selective gas-water-oil separation

    OpenAIRE

    Jihye Bong; Taekyung Lim; Keumyoung Seo; Cho-Ah Kwon; Ju Hyun Park; Sang Kyu Kwak; Sanghyun Ju

    2015-01-01

    Selective filtration of gas, water, and liquid or gaseous oil is essential to prevent possible environmental pollution and machine/facility malfunction in oil-based industries. Novel materials and structures able to selectively and efficiently filter liquid and vapor in various types of solutions are therefore in continuous demand. Here, we investigate selective gas-water-oil filtration using three-dimensional graphene structures. The proposed approach is based on the adjustable wettability o...

  14. Postoperative socket irrigation with drinking tap water reduces the risk of inflammatory complications following surgical removal of third molars: a multicenter randomized trial

    NARCIS (Netherlands)

    Ghaeminia, H.; Hoppenreijs, T.J.; Xi, T.; Fennis, J.P.; Maal, T.J.J.; Berge, S.J.; Meijer, G.J.

    2017-01-01

    OBJECTIVES: The primary aim of the present study was to evaluate the effectiveness of postoperative irrigation of the socket with drinking tap water on inflammatory complications following lower third molar removal. MATERIAL AND METHODS: A multicenter randomized controlled trial was carried out from

  15. Electrochemical Performances of Diamond Like Carbon Films for Pb(II) Detection in Tap Water Using Differential Pulse Anodic Stripping Voltammetry Technique

    Czech Academy of Sciences Publication Activity Database

    Sbartai, A.; Namour, F.; Barbier, F.; Krejčí, J.; Kučerová, R.; Krejčí, T.; Neděla, Vilém; Sobota, Jaroslav; Jaffrezic-Renault, N.

    2013-01-01

    Roč. 11, č. 8 (2013), s. 1524-1529 ISSN 1546-198X Institutional support: RVO:68081731 Keywords : Diamond Like Carbon DLC * Lead Detection * Differential Pulse Anodic Stripping * Voltammetry * Tap Water Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.558, year: 2013

  16. Drinking Water in your Home

    Science.gov (United States)

    Many people choose to filter or test the drinking water that comes out of their tap or from their private well for a variety of reasons. And whether at home, at work or while traveling, many Americans drink bottled water.

  17. Modeling the sustainability of a ceramic water filter intervention.

    Science.gov (United States)

    Mellor, Jonathan; Abebe, Lydia; Ehdaie, Beeta; Dillingham, Rebecca; Smith, James

    2014-02-01

    Ceramic water filters (CWFs) are a point-of-use water treatment technology that has shown promise in preventing early childhood diarrhea (ECD) in resource-limited settings. Despite this promise, some researchers have questioned their ability to reduce ECD incidences over the long term since most effectiveness trials conducted to date are less than one year in duration limiting their ability to assess long-term sustainability factors. Most trials also suffer from lack of blinding making them potentially biased. This study uses an agent-based model (ABM) to explore factors related to the long-term sustainability of CWFs in preventing ECD and was based on a three year longitudinal field study. Factors such as filter user compliance, microbial removal effectiveness, filter cleaning and compliance declines were explored. Modeled results indicate that broadly defined human behaviors like compliance and declining microbial effectiveness due to improper maintenance are primary drivers of the outcome metrics of household drinking water quality and ECD rates. The model predicts that a ceramic filter intervention can reduce ECD incidence amongst under two year old children by 41.3%. However, after three years, the average filter is almost entirely ineffective at reducing ECD incidence due to declining filter microbial removal effectiveness resulting from improper maintenance. The model predicts very low ECD rates are possible if compliance rates are 80-90%, filter log reduction efficiency is 3 or greater and there are minimal long-term compliance declines. Cleaning filters at least once every 4 months makes it more likely to achieve very low ECD rates as does the availability of replacement filters for purchase. These results help to understand the heterogeneity seen in previous intervention-control trials and reemphasize the need for researchers to accurately measure confounding variables and ensure that field trials are at least 2-3 years in duration. In summary, the CWF

  18. Assessment of tap water quality and corrosion scales from the selected distribution systems in northern Pakistan.

    Science.gov (United States)

    Baig, Shams Ali; Lou, Zimo; Baig, Muzaffar Ali; Qasim, Muhammad; Shams, Dilawar Farhan; Mahmood, Qaisar; Xu, Xinhua

    2017-04-01

    Corrosion deposits formed within drinking water distribution systems deteriorate drinking water quality and resultantly cause public health consequences. In the present study, an attempt was made to investigate the concurrent conditions of corrosion scales and the drinking water quality in selected water supply schemes (WSS) in districts Chitral, Peshawar, and Abbottabad, northern Pakistan. Characterization analyses of the corrosion by-products revealed the presence of α-FeOOH, γ-FeOOH, Fe 3 O 4 , and SiO 2 as major constituents with different proportions. The constituents of all the representative XRD peaks of Peshawar WSS were found insignificant as compared to other WSS, and the reason could be the variation of source water quality. Well-crystallized particles in SEM images indicated the formation of dense oxide layer on corrosion by-products. A wider asymmetric vibration peak of SiO 2 appeared only in Chitral and Abbottabad WSS, which demonstrated higher siltation in the water source. One-way ANOVA analysis showed significant variations in pH, turbidity, TDS, K, Mg, PO 4 , Cl, and SO 4 values, which revealed that these parameters differently contributed to the source water quality. Findings from this study suggested the implementation of proper corrosion prevention measures and the establishment of international collaboration for best corrosion practices, expertise, and developing standards.

  19. Quantification of Saprolegnia parasitica in river water using real-time quantitative PCR: from massive fish mortality to tap drinking water.

    Science.gov (United States)

    Rocchi, Steffi; Tisserant, Maxime; Valot, Benoit; Laboissière, Audrey; Frossard, Victor; Reboux, Gabriel

    2017-02-01

    Since 2010, the Loue River (Franche-Comté, East of France) has been suffering from massive fish kills infested by Saprolegnia parasitica. The river supplies inhabitants of the city of Besançon in drinking water, raising the question of a potential risk through both water consumption and use. We developed a real-time quantitative PCR (qPCR) to quantify S. parasitica in the Loue River as well as in the drinking water. A weak spatial trend is suggested with greater quantities of S. parasitica observed at the sampling station close to the main pumping station. No S. parasitica DNA was detected in the tap water connected to pumping stations. The use of qPCR, which combines specificity, practicality, speed and reliability, appears to be an effective tool to monitor the spatial and temporal dynamics of this oomycete and identify the risk period for wild salmonid populations in the field, for fishery management or in aquaculture.

  20. Concentrations of 222Rn in well and tap waters of North-Eastern Attiki (Central Greece)

    International Nuclear Information System (INIS)

    Kritidis, Panaiotis; Angelou, Panaiotis.

    1984-07-01

    An alpha-scintillation system for determination of low 222 Rn concentrations in water is described. The use of vacuum sampling, the avoidance of sample transfer and the corrections applied result in low systematical errors. The method has been used for a preliminary investigation of 222 Rn concentrations in well waters of NE Attiki, where values between 4 and 345 pCi/1 have been observed. The additional annual effective dose equivalent due to the systematic domestic use of water with the highest radon concentration measured is estimated not to exceed 5 mrem. (author)

  1. Monitoring of Emerging and Legacy Contaminants in Groundwater and Tap Water of the Karst Region in Northern Puerto Rico for Assessment of Sources and Fate and Transport Processes

    Science.gov (United States)

    Padilla, I. Y.; Cotto, I.; Torres, P. M.

    2014-12-01

    The karst aquifer region of northern Puerto Rico is the area with the highest groundwater extraction in the island. Urban and industrial development has led to extensive contamination of the groundwater in the region. Of particular concern, is the presence of emerging and legacy organic contaminants, such as phthalates and chlorinated organic compounds (CVOCs), because there high risk for exposure and adverse health impact. Variable sources and the heterogeneous and dynamic conditions of karst groundwater systems, limits the ability to properly assess and manage the water quality of these precious water resources. This work develops a monitoring and water analysis scheme to assess spatial-temporal exposure of hazardous contaminants trough karst water in northern Puerto Rico. Groundwater and tap water are sampled in the region and analyzed for phthalates, CVOCs, and common ions. Detections and concentrations of phthalates and CVOCs are determined by using modified EPA methods, which rely on liquid-liquid extractions and gas chromatography techniques. The modified methods have reduced the volume of samples and solvent waste, decreased the time of analysis, increased analysis outcomes, and lower potential for hazardous exposure. Results show intermittent presence of di-ethyl, di-butyl and di (2-ethyl hexyl) phthalates in 36% of the groundwater and 53% of tap water samples, with detected concentrations ranging between 0.1-88.7 μg/L. These results indicate that karst groundwater can serve as a route of exposure for phthalates, but there are additional disperse sources in the water system. CVOCs are detected in groundwater at much higher frequencies (50%) than phthalates, and include trichloromethane (TCM), carbon tetrachloride (CT), trichloroethylene (TCE), and tetrachloroethylene (TCE). CVOCs, except for TCM, are found at lower frequencies on tap water (5.8%) than groundwater (27%). TCM is detected more frequently and at higher concentrations in tap water (56.8%) than

  2. A Novel Liquid-Liquid Extraction for the Determination of Sertraline in Tap Water and Waste Water at Trace Levels by GC-MS.

    Science.gov (United States)

    Koçoğlu, Elif Seda; Bakırdere, Sezgin; Keyf, Seyfullah

    2017-09-01

    A simple, green and fast analytical method was developed for the determination of sertraline in tap and waste water samples at trace levels by using supportive liquid-liquid extraction with gas chromatography-mass spectrometry. Different parameters affecting extraction efficiency such as types and volumes of extraction and supporter solvents, extraction period, salt type and amount were optimized to get lower detection limits. Ethyl acetate was selected as optimum extraction solvent. In order to improve the precision, anthracene-D10 was used as an internal standard. The calibration plot of sertraline was linear from 1.0 to 1000 ng/mL with a correlation coefficient of 0.999. The limit of detection value under the optimum conditions was found to be 0.43 ng/mL. In real sample measurements, spiking experiments were performed to check the reliability of the method for these matrices. The spiking experiments yielded satisfactory recoveries of 91.19 ± 2.48%, 90.48 ± 5.19% and 95.46 ± 6.56% for 100, 250 and 500 ng/mL sertraline for tap water, and 85.80 ± 2.15% and 92.43 ± 4.02% for 250 and 500 ng/mL sertraline for waste water.

  3. Measuring the Willingness to Pay for Tap Water Quality Improvements: Results of a Contingent Valuation Survey in Pusan

    Directory of Open Access Journals (Sweden)

    Chang-Seob Kim

    2013-10-01

    Full Text Available With increasing concern regarding health, people have developed an interest in the safety of drinking water. In this study, we attempt to measure the economic benefits of tap water quality improvement through a case study on Pusan, the second largest city in Korea. To this end, we use a scenario that the government plans to implement a new project of improving water quality and apply the contingent valuation (CV method. A one-and-one-half bounded dichotomous choice question (OOHBDC format is employed to reduce the potential for response bias in multiple-bound formats such as the double-bound model, while maintaining much of the efficiency. Moreover, we employ the spike model to deal with zero willingness to pay (WTP responses from the OOHBDC CV survey. The CV survey of 400 randomly selected households was rigorously designed to comply with the guidelines for best-practice CV studies using person-to-person interviews. From the spike OOHBDC CV model, the mean WTP for the improvement was estimated to be KRW 2,124 (USD 2.2, on average, per household, per month. The value amounts to 36.6% of monthly water bill and 20.2% of production costs of water. The conventional OOHBDC model produces statistically insignificant mean WTP estimate and even negative value, but the OOHBDC spike model gives us statistically significant mean WTP estimate and fitted our data well. The WTP value to Pusan residents can be computed to be KRW 31.2 billion (USD 32.1 million per year.

  4. Water flow exchange characteristics in coarse granular filter media

    DEFF Research Database (Denmark)

    Andreasen, Rune Røjgaard; Pugliese, Lorenzo; Poulsen, Tjalfe

    2013-01-01

    in this study are performed at a concurrent airflow of 0.3 m s−1, water irrigation rates of 1–21 cm h−1 in materials with particle diameters ranging from 2 to 14 mm to represent media and operation conditions relevant for low flow biotrickling filter design. Specific surface area related elution velocity...... constitutes a scientific gap. This study investigates the impact of particle size distribution (considering materials with multiple particle sizes) and irrigation rate on the overall specific surface area related elution velocity distribution in porous granular media. The elution measurements performed...... distribution was closely related to the filter water content, water irrigation rate, media specific surface area and particle size distribution. A predictive model linking the specific surface area related elution velocity distribution to irrigation rate, specific surface area and particle size distribution...

  5. Low Contribution of PbO 2 -Coated Lead Service Lines to Water Lead Contamination at the Tap

    Energy Technology Data Exchange (ETDEWEB)

    Triantafyllidou, Simoni [Oak Ridge Institute; Schock, Michael R. [Water Supply; amp,; DeSantis, Michael K. [Oak Ridge Institute; White, Colin [Department; amp, Applied Science, University of Cincinnati, Cincinnati, Ohio 45221, United States

    2015-02-24

    To determine if residential water sampling corroborates the expectation that formation of stable PbO2 coatings on lead service lines (LSLs) provides an effective lead release control strategy, lead profile sampling was evaluated for eight home kitchen taps in three U.S. cities with observed PbO2-coated LSLs (Newport, Rhode Island; Cincinnati and Oakwood, Ohio). After various water standing times, these LSLs typically released similar or lower peak lead levels (1 to 18 μg/L) than the lead levels from the respective kitchen faucets (1 to 130 μg/L), and frequently 50–80% lower than the lead levels typically reported from Pb(II)-coated LSLs in comparable published sampling studies. Prolonged stagnation (10–101 h) at the Cincinnati sites produced varying results. One site showed minimal (0–4 μg/L) increase in lead release from the PbO2-coated LSL, and persistence of free chlorine residual. However, the other site showed up to a 3-fold increase proportional to standing time, with essentially full depletion of the chlorine residual. Overall, lead release was consistently much lower than that reported in studies of Pb(II)-coated LSL scales, suggesting that natural formation of PbO2 in LSLs is an effective lead “corrosion” control strategy.

  6. Antimycobacterial potential of the juniper berry essential oil in tap water.

    Science.gov (United States)

    Peruč, Dolores; Gobin, Ivana; Abram, Maja; Broznić, Dalibor; Svalina, Tomislav; Štifter, Sanja; Staver, Mladenka Malenica; Tićac, Brigita

    2018-03-01

    Mycobacterium avium complex-related diseases are often associated with poorly maintained hot water systems. This calls for the development of new control strategies. The aim of this study was to investigate the activity of essential oils (EOs) from the Mediterranean plants, common juniper, immortelle, sage, lavandin, laurel, and white cedar against Mycobacterium avium ssp. avium, Mycobacterium intracellulare, and Mycobacterium gordonae in culturing broth and freshwater as their most common habitat. To do that, we developed a new method of water microdilution to determine their minimal effective concentrations (MEC). The most active EO was the one from the common juniper with the MEC of 1.6 mg mL-1. Gas chromatography / mass spectrometry the juniper EO identified monoterpenes (70.54 %) and sesquiterpenes (25.9 %) as dominant component groups. The main monoterpene hydrocarbons were α-pinene, sabinene, and β-pinene. The juniper EO significantly reduced the cell viability of M. intracellulare and M. gordonae at MEC, and of M. avium at 2xMEC. Microscopic analysis confirmed its inhibitory effect by revealing significant morphological changes in the cell membrane and cytoplasm of all three bacteria. The mode of action of the juniper EO on the cell membrane was confirmed by a marked leakage of intracellular material. Juniper EO has a great practical potential as a complementary or alternative water disinfectant in hot water systems such as baths, swimming pools, spa pools, hot tubs, or even foot baths/whirlpools.

  7. Determination of Arsenic in Sinus Wash and Tap Water by Inductively Coupled Plasma-Mass Spectrometry

    Science.gov (United States)

    Donnell, Anna M.; Nahan, Keaton; Holloway, Dawone; Vonderheide, Anne P.

    2016-01-01

    Arsenic is a toxic element to which humans are primarily exposed through food and water; it occurs as a result of human activities and naturally from the earth's crust. An experiment was developed for a senior level analytical laboratory utilizing an Inductively Coupled Plasma-Mass Spectrometer (ICP-MS) for the analysis of arsenic in household…

  8. Compatibility between Hydraulic and Mechanical Properties of Ceramic Water Filters

    Directory of Open Access Journals (Sweden)

    Riyadh Z. Al Zubaidy

    2017-05-01

    Full Text Available In this paper, ceramic water filters were produced by using ten mixtures of different ratios of red clay and sawdust under different production conditions. The physical properties of these filters were tested. The production conditions include five press pressures ranged from 10 to 50MPa and a firing schedule having three different final temperatures of 1000, 1070, and 1100˚C. The tests results of the physical properties were used to obtain best compatibility between the hydraulic and the mechanical properties of these filters. Results showed that as the press pressure and the firing temperature are increased, the bulk density and the compressive and bending strengths of the produced filters are increased, while, the porosity and absorption are decreased. As the sawdust content is increased the bulk density and the compressive and bending strengths are decreased, while, the porosity and absorption are increased. High hydraulic conductivity is obtained at a firing temperature of 1070˚C when the sawdust content is less than 10%. Otherwise, it is increased as sawdust content and the firing temperature are increased. Filters made of mixture 92.5% red clay and 7.5% sawdust formed . under a press pressure of 20MPa and a firing temperature of 1070˚C gave the best compatibility between hydraulic and mechanical properties. In this case, the hydraulic conductivity was 50mm/day, the compressive strength was 14MPa, and the bending strength was 10.8MPa.

  9. Trace element analysis of mineral and tap water samples using total reflection x-ray fluorescence (TXRF)

    International Nuclear Information System (INIS)

    Mangala, M.J.; Korir, K.A.; Maina, D.M.; Kinyua, A.M.

    2000-01-01

    Results of trace element analysis by TXRF of tap water and various brands of bottled mineral water samples which are representative of local and imported brands sold in Nairobi are reported. The variation in elemental concentrations in water samples analyzed were as follows: potassium (K) 0.2 to 28.9 μg/ml; calcium (Ca) 2.2 to 120 μg/ml; titanium (Ti) 11 to 60 μg/l; manganese (Mn) 8 to 670 μg/l; iron (Fe) 31 to 540 μg/l; copper (Cu) 8 to 30 μg/l; zinc (Zn) 8 to 4730 μg/l; bromine (Br) 9 to 248 μg/l; rubidium (Rb) 10 to 40 μg/l and strontium (Sr) 10 to 1000 μg/l. Local mineral water samples contain higher levels of trace elements; manganese (Mn), zinc (Zn), bromine (Br), rubidium (Rb) and strontium (Sr) as compared to the imported brands. Principal component analysis of the results revealed three component loading factors clusters for: rubidium (Rb), strontium (Sr) and calcium (Ca); titanium (Ti), iron (Fe), bromine (Br), and zinc (Zn); zinc (Zn), manganese (Mn) and potassium (K) respectively. The percentage of total variance explained by the components was 31.4, 27.3, and 14.8 respectively. In this study, we also found that a limited spread of 5-6 mm for a 10 μl sample was achieved when the quartz sample carrier was dried in a low pressure (300 mbar) oven at 70 o C for 10 hours. (author)

  10. Quantifying the Water Footprint of Manufactured Products: A Case Study of Pitcher Water Filters

    Directory of Open Access Journals (Sweden)

    Ashley Barker

    2012-01-01

    Full Text Available Fresh water is a finite resource that is critically needed bysociety for a variety of purposes. The demand for freshwater will grow as the world population and global livingstandard increase, and fresh water shortages will becomemore commonplace. This will put significant stress onsociety. It has been argued that fresh water may becomethe next oil, and efforts have to be made to better manageits fresh water consumption by agricultural and domesticusers. Industry also uses large amounts. Surprisingly, onlyrecently is serious attention being directed toward waterrelatedissues. This effort to quantify the water footprint ofa manufactured product represents one of the first initiativesto characterize the role of water in a discrete good.This study employed a life cycle assessment methodologyto determine the water footprint of a pitcher water filter.This particular product was selected because many waterintensivematerials and processes are needed to produceits major components: for example, agricultural processesused to produce activated carbon and petrochemicalprocesses used to produce the polypropylene casing. Inaddition, a large amount of water is consumed during theproduct’s use phase. Water data was obtained from theEcoinvent 2.1 database and categorized as either beingassociated with blue or green water.The blue water footprint (surface water consumption forthe pitcher water filter was 76 gallons per filter: 10 gallonsconsumed for materials extraction, 15 gallons for themanufacturing stage, and 50 gallons during the use phase.The green water footprint (precipitation was associatedwith the cultivation of the coconut tree; activated carbonis obtained from the coconut shells. The green waterfootprint was calculated to be 164 gallons per filter.The overall water footprint was 240 gallons per filter;the filter footprint is heavily dominated by green water(68% rather than blue water (32%. Future studies mayinvestigate how the production and

  11. Relationship between antibiotic- and disinfectant-resistance profiles in bacteria harvested from tap water.

    Science.gov (United States)

    Khan, Sadia; Beattie, Tara K; Knapp, Charles W

    2016-06-01

    Chlorination is commonly used to control levels of bacteria in drinking water; however, viable bacteria may remain due to chlorine resistance. What is concerning is that surviving bacteria, due to co-selection factors, may also have increased resistance to common antibiotics. This would pose a public health risk as it could link resistant bacteria in the natural environment to human population. Here, we investigated the relationship between chlorine- and antibiotic-resistances by harvesting 148 surviving bacteria from chlorinated drinking-water systems and compared their susceptibilities against chlorine disinfectants and antibiotics. Twenty-two genera were isolated, including members of Paenibacillus, Burkholderia, Escherichia, Sphingomonas and Dermacoccus species. Weak (but significant) correlations were found between chlorine-tolerance and minimum inhibitory concentrations against the antibiotics tetracycline, sulfamethoxazole and amoxicillin, but not against ciprofloxacin; this suggest that chlorine-tolerant bacteria are more likely to also be antibiotic resistant. Further, antibiotic-resistant bacteria survived longer than antibiotic-sensitive organisms when exposed to free chlorine in a contact-time assay; however, there were little differences in susceptibility when exposed to monochloramine. Irrespective of antibiotic-resistance, spore-forming bacteria had higher tolerance against disinfection compounds. The presence of chlorine-resistant bacteria surviving in drinking-water systems may carry additional risk of antibiotic resistance. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. The Management of Silica in Los Alamos National Laboratory Tap Water - A Study of Silica Solubility

    Energy Technology Data Exchange (ETDEWEB)

    Wohlberg, C.; Worland, V.P.; Kozubal, M.A.; Erickson, G.F.; Jacobson, H.M.; McCarthy, K.T.

    1999-07-01

    Well water at Los Alamos National Laboratory (LANL) has a silica (SiO{sub 2}) content of 60 to 100 mg/L, with 4 mg/L of magnesium, 13 mg/L calcium and lesser concentrations of other ions. On evaporation in cooling towers, when the silica concentration reaches 150 to 220 mg/L, silica deposits on heat transfer surfaces. When the high silica well water is used in the reprocessing of plutonium, silica remains in solution at the end of the process and creates a problem of removal from the effluent prior to discharge or evaporation. The work described in this Report is divided into two major parts. The first part describes the behavior of silica when the water is evaporated at various conditions of pH and in the presence of different classes of anions: inorganic and organic. In the second part of this work it was found that precipitation (floccing) of silica was a function of solution pH and mole ratio of metal to silica.

  13. Determination of copper in tap water using solid-phase spectrophotometry

    Science.gov (United States)

    Hill, Carol M.; Street, Kenneth W.; Philipp, Warren H.; Tanner, Stephen P.

    1994-01-01

    A new application of ion exchange films is presented. The films are used in a simple analytical method of directly determining low concentrations of Cu(2+) in aqueous solutions, in particular, drinking water. The basis for this new test method is the color and absorption intensity of the ion when adsorbed onto the film. The film takes on the characteristic color of the adsorbed cation, which is concentrated on the film by many orders of magnitude. The linear relationship between absorbance (corrected for variations in film thickness) and solution concentration makes the determinations possible. These determinations agree well with flame atomic absorption determinations.

  14. Determination of glyphosate and aminomethylphosphonic acid for assessing the quality tap water using SPE and HPLC

    Directory of Open Access Journals (Sweden)

    Eduardo Luiz Delmonico

    2014-02-01

    Full Text Available The use of pesticides in agriculture is one of the current problems that may result in contamination of both ground and surface water and groundwater. Considering the environmental importance and the increasing use of herbicides in Maringá region, in the present work methods for extraction and determination of glyphosate (GLYP and aminomethylphosphonic acid (AMPA using solid phase extraction (SPE and high performance liquid chromatography (HPLC were developed. For SPE, anion exchange resin was used and elution was done with hydrochloric acid 50.0 mmol L-1, achieving recovery rates of 82.5-116.2% and 67.1-104.0% for AMPA and GLYP, respectively. For HPLC determination the analytes were derivatized and injected in the HPLC with a C18 column and using mobile phase consisting of phosphate buffer 0.20 mol L-1 at pH 3.0 and acetonitrile (85:15; the monitoring was done at 240 nm. The analysis was performed in 8 min with the same limit of detection and limit of quantification for AMPA and GLYP of 0.09 and 0.20 mg L-1, respectively. The methods were applied to analysis of public water supply samples and concentrations from 2.1 up to 2.9 µg L-1 for AMPA and from 2.3 up to 3.3 µg L-1 for glyphosate were found.

  15. Comparison of Fluoride Levels in Tap and Bottled Water and Reported Use of Fluoride Supplementation in a United States–Mexico Border Community

    Directory of Open Access Journals (Sweden)

    Paloma I. Beamer

    2017-04-01

    Full Text Available BackgroundCompared to the general United States (U.S. population, Arizona counties along the U.S.–Mexico border have a higher prevalence of dental caries, which can be reduced with adequate fluoride exposure. Because of concern regarding local tap water quality, fluoride-free bottled water consumption is common in this region, raising concern that families are not receiving adequate fluoride to promote dental health.ObjectiveTo evaluate the levels of fluoride in tap and bottled water as well as the use of fluoride supplements in an Arizona border community.MethodsLow-income Latino households (n = 90 who report use of bottled water as their primary source of water intake were recruited. Participants completed a questionnaire about their and their children’s dental histories and use of fluoride supplements. Water samples (bottled and tap were collected from a subset of households (n = 30 for analysis of fluoride.ResultsFluoride detection levels were significantly greater (p = 0.02, Fisher’s exact test in tap water (average = 0.49 mg/dL than in bottled water, yet, the majority (22/30 were below the range for optimal dental health (0.7–1.2 mg/L. Concentration of fluoride in the majority (29/30 of bottled water samples was below the quantitative detection limit of 0.4 mg/L. Children were significantly less likely to have dental caries if they received fluoride varnishing treatments (p = 0.01, Fisher’s exact test, lived in households that reported using fluoridated mouthwash (p < 0.001, Fisher’s exact test, their parents received fluoride education (p = 0.01, Fisher’s exact test, and their parents reported visiting a dentist yearly (p < 0.001, Fisher’s exact test. Furthermore, none of the participants reported receiving recommendations from health-care providers about fluoride supplementation or variance in content by the type of water consumed.ConclusionAlthough fluoride was significantly more

  16. Comparison of Fluoride Levels in Tap and Bottled Water and Reported Use of Fluoride Supplementation in a United States-Mexico Border Community.

    Science.gov (United States)

    Victory, Kerton R; Cabrera, Nolan L; Larson, Daniela; Reynolds, Kelly A; Latura, Joyce; Thomson, Cynthia A; Beamer, Paloma I

    2017-01-01

    Compared to the general United States (U.S.) population, Arizona counties along the U.S.-Mexico border have a higher prevalence of dental caries, which can be reduced with adequate fluoride exposure. Because of concern regarding local tap water quality, fluoride-free bottled water consumption is common in this region, raising concern that families are not receiving adequate fluoride to promote dental health. To evaluate the levels of fluoride in tap and bottled water as well as the use of fluoride supplements in an Arizona border community. Low-income Latino households ( n  = 90) who report use of bottled water as their primary source of water intake were recruited. Participants completed a questionnaire about their and their children's dental histories and use of fluoride supplements. Water samples (bottled and tap) were collected from a subset of households ( n  = 30) for analysis of fluoride. Fluoride detection levels were significantly greater ( p  = 0.02, Fisher's exact test) in tap water (average = 0.49 mg/dL) than in bottled water, yet, the majority (22/30) were below the range for optimal dental health (0.7-1.2 mg/L). Concentration of fluoride in the majority (29/30) of bottled water samples was below the quantitative detection limit of 0.4 mg/L. Children were significantly less likely to have dental caries if they received fluoride varnishing treatments ( p  = 0.01, Fisher's exact test), lived in households that reported using fluoridated mouthwash ( p  < 0.001, Fisher's exact test), their parents received fluoride education ( p  = 0.01, Fisher's exact test), and their parents reported visiting a dentist yearly ( p  < 0.001, Fisher's exact test). Furthermore, none of the participants reported receiving recommendations from health-care providers about fluoride supplementation or variance in content by the type of water consumed. Although fluoride was significantly more likely to be detected in tap than bottled water

  17. Arsenic removal from drinking water by a household sand filter in Vietnam--effect of filter usage practices on arsenic removal efficiency and microbiological water quality.

    Science.gov (United States)

    Nitzsche, Katja Sonja; Lan, Vi Mai; Trang, Pham Thi Kim; Viet, Pham Hung; Berg, Michael; Voegelin, Andreas; Planer-Friedrich, Britta; Zahoransky, Jan; Müller, Stefanie-Katharina; Byrne, James Martin; Schröder, Christian; Behrens, Sebastian; Kappler, Andreas

    2015-01-01

    Household sand filters are applied to treat arsenic- and iron-containing anoxic groundwater that is used as drinking water in rural areas of North Vietnam. These filters immobilize poisonous arsenic (As) via co-oxidation with Fe(II) and sorption to or co-precipitation with the formed Fe(III) (oxyhydr)oxides. However, information is lacking regarding the effect of the frequency and duration of filter use as well as of filter sand replacement on the residual As concentrations in the filtered water and on the presence of potentially pathogenic bacteria in the filtered and stored water. We therefore scrutinized a household sand filter with respect to As removal efficiency and the presence of fecal indicator bacteria in treated water as a function of filter operation before and after sand replacement. Quantification of As in the filtered water showed that periods of intense daily use followed by periods of non-use and even sand replacement did not significantly (pwater (95% removal). The first flush of water from the filter contained As concentrations below the drinking water limit and suggests that this water can be used without risk for human health. Colony forming units (CFUs) of coliform bacteria increased during filtration and storage from 5 ± 4 per 100mL in the groundwater to 5.1 ± 1.5 × 10(3) and 15 ± 1.4 × 10(3) per 100mL in the filtered water and in the water from the storage tank, respectively. After filter sand replacement, CFUs of Escherichia coli of water by qPCR targeting the 23S rRNA gene. The results demonstrate the efficient and reliable performance of household sand filters regarding As removal, but indicate a potential risk for human health arising from the enrichment of coliform bacteria during filtration and from E. coli cells that are introduced by sand replacement. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Hydrocyclone for pre-filtering of irrigation water

    Directory of Open Access Journals (Sweden)

    Soccol Olívio José

    2004-01-01

    Full Text Available The use of water containing suspended sediments causes serious problems to irrigation systems. Choosing the right filtering system type and capacity is essential to avoid increases in operational and maintenance costs of irrigation resulting from the need for cleaning and frequent component replacing. Pre-filters, such as the hydrocyclone, are important for their significant capability of retaining particles suspended in the water. Data on hydrocyclones performance for pre-filtering of irrigation water can be found in the literature, but research data in Brazil are scarce. Therefore, four Rietema type hydrocyclones (50 mm diameter were constructed, one with circular-end and the other three presenting rectangular-end feeding tubes. The evaluation of hydrocyclones performance was conducted by using suspensions of fine sand and clay soil particles under varied pressure differentials. The comparison criteria were the discharge and the separation capability, given by total efficiency and reduced total efficiency. The hydrocyclone with circular-end feeding tube presented the highest indexes for the adopted criteria, considering sand and soil suspensions.

  19. INVESTIGATION OF CHANGES OF PHYSICAL AND CHEMICAL PROPERTIES OF TAP WATER UNDER INFLUENCE OF POWERFUL UNDERWATER SPARK DISCHARGES

    Directory of Open Access Journals (Sweden)

    D. V. Vinnikov

    2017-03-01

    Full Text Available Purpose. The purpose of this investigation is to study the changes in the redox potential and pH-value of the tap water as a function of underwater spark discharges, storage device capacitance and the charging voltage. Methodology. To define the electric parameters of discharge circuit we used the Rogowski loop and the compensated capacitance-ohm potential divider. To determine water properties before and after the treatment we used the following devices: the water analyzer Anion -7051 with the limit of absolute error of the EMF measurement ± 2 mV, the BANTE 902 device with the absolute error of ± 0.002 рН. Results. We managed to establish the time of the origination of changes in the properties of treated water. A change in the positive redox potential to a negative one occurred already after the third pulse at a total energy input of ≥ 1 kJ. The pH value increased in the range of 0.2 – 0.45 рН units. We obtained the relationship of a change in the redox potential as a function of total energy of the pulse train that actually exhibits the linear relation to the mass of erosion products. We established that the electrodes made of stainless steel and the electrodes made of graphite provide similar changes in water properties. An increase in pH is indicative of the progress of reactions that result in the formation of ОН‾. Originality. The obtained experimental data prove a rapid and reliable change in the redox potential from positive to negative changes in the redox potential exponent can persist during ten days and even longer. The erosion products of electrodes can be removed from the treated water using the method of magnetic separation. Practical value. The «HYDRA» plant can be used as the electrochemical ideal mixing reactor of a discrete action with the removal of erosion products of the electrode using the method of magnetic separation.

  20. The δ2H and δ18O of tap water from 349 sites in the United States and selected territories

    Science.gov (United States)

    Coplen, Tyler B.; Landwehr, Jurate M.; Qi, Haiping; Lorenz, Jennifer M.

    2013-01-01

    Because the stable isotopic compositions of hydrogen (δ2H) and oxygen (δ18O) of animal (including human) tissues, such as hair, nail, and urine, reflect the δ2H and δ18O of water and food ingested by an animal or a human and because the δ2H and δ18O of environmental waters vary geographically, δ2H and δ18O values of tap water samples collected in 2007-2008 from 349 sites in the United States and three selected U.S. territories have been measured in support of forensic science applications, creating one of the largest databases of tap water δ2H and δ18O values to date. The results of replicate isotopic measurements for these tap water samples confirm that the expanded uncertainties (U = 2μc) obtained over a period of years by the Reston Stable Isotope Laboratory from δ2H and δ18O dual-inlet mass spectrometric measurements are conservative, at ±2‰ and ±0.2 ‰, respectively. These uncertainties are important because U.S. Geological Survey data may be needed for forensic science applications, including providing evidence in court cases. Half way through the investigation, an isotope-laser spectrometer was acquired, enabling comparison of dual-inlet isotope-ratio mass spectrometric results with isotope-laser spectrometric results. The uncertainty of the laser-based δ2H measurement results for these tap water samples is comparable to the uncertainty of the mass spectrometric method, with the laser-based method having a slightly lower uncertainty. However, the δ18O uncertainty of the laser-based method is more than a factor of ten higher than that of the dual-inlet isotoperatio mass spectrometric method.

  1. Randomised controlled trial of thermostatic mixer valves in reducing bath hot tap water temperature in families with young children in social housing: A protocol

    Directory of Open Access Journals (Sweden)

    Phillips Ceri

    2008-03-01

    Full Text Available Abstract Background Each year in the UK 2000 children attend emergency departments and 500 are admitted to hospital following a bath water scald. The long term effects can include disability, disfigurement or psychological harm and repeated skin grafts may be required as the child grows. The costs of treating a severe scald are estimated at 250,000 GBP. Children living in the most deprived wards are at greatest risk of thermal injuries; hospital admission rates are three times that for children living in the least deprived wards. Domestic hot water, which is usually stored at around 60 degrees Celsius, can result in a second-degree burn after 3 seconds and a third-degree burn after 5 seconds. Educational strategies to encourage testing of tap water temperature and reduction of hot water thermostat settings have largely proved unsuccessful. Legislation in the USA mandating pre-setting hot water heater thermostats at 49 degrees Celsius was effective in reducing scald injuries, suggesting passive measures may have a greater impact. Thermostatic mixer valves (TMVs, recently developed for the domestic market, fitted across the hot and cold water supply pipes of the bath, allow delivery of water set at a fixed temperature from the hot bath tap. These valves therefore offer the potential to reduce scald injuries. Design/Methods A pragmatic, randomised controlled trial to assess the effectiveness of TMVs in reducing bath hot tap water temperatures in the homes of families with young children in rented social housing. Two parallel arms include an intervention group and a control group where the intervention will be deferred. The intervention will consist of fitting a TMV (set at 44 degrees Celsius by a qualified plumber and provision of educational materials. The control arm will not receive a TMV or the educational materials for the study duration but will be offered the intervention after collection of follow-up data 12 months post randomisation. The

  2. Rotating carbon nanotube membrane filter for water desalination

    Science.gov (United States)

    Tu, Qingsong; Yang, Qiang; Wang, Hualin; Li, Shaofan

    2016-01-01

    We have designed a porous nanofluidic desalination device, a rotating carbon nanotube membrane filter (RCNT-MF), for the reverse osmosis desalination that can turn salt water into fresh water. The concept as well as design strategy of RCNT-MF is modeled, and demonstrated by using molecular dynamics simulation. It has been shown that the RCNT-MF device may significantly improve desalination efficiency by combining the centrifugal force propelled reverse osmosis process and the porous CNT-based fine scale selective separation technology. PMID:27188982

  3. REMOVING BIOMASS FROM WATER PONDS AND SMALL WATER RESERVOIRS BY USING NON-WOVEN FILTERS

    Directory of Open Access Journals (Sweden)

    Jakub Nieć

    2015-10-01

    Full Text Available Small water bodies, for example garden ponds, play many functions in the environment, including biocenotic, hydrological, climatic, sozological, landfill-creative, and aesthetic. Due to their small size, these reservoirs are sensitive to external and internal factors, they are also a common natural contaminants receivers. Nonwoven filters have been investigated for several years as a useful device for treatment of domestic wastewater pre-treated in a septic tank. The aim of this study was to verify the possibility of using this type of filters for water originating from small water body purification. The effectiveness of filters were tested on the water originating from the garden pond, contained high levels of nutrients and intensive algal bloom. Research was carried out on three filters (each filter consisted of four geotextile TS 20 layers. Basic water quality indicators: total suspended solids, turbidity, COD and BOD5, temperature, pH and dissolved oxygen were measured. The research results can be considered as satisfactory in terms of mechanical treatment (removal of turbidity and total suspended solids. An important positive effect of the filters was the oxygenation of the treated water, which is especially important for fish.

  4. Point-of-use water purification using clay pot water filters and copper ...

    African Journals Online (AJOL)

    All other critical parameters such as total hardness, turbidity, electrical conductivity and ions in the filtered water were also within acceptable levels for drinking water quality. The filtration rate of the pot was also measured as a function of grain size of the sawdust and height of the water column in it. The filtration rate was ...

  5. A method for improving reliability and relevance of LCA reviews: the case of life-cycle greenhouse gas emissions of tap and bottled water.

    Science.gov (United States)

    Fantin, Valentina; Scalbi, Simona; Ottaviano, Giuseppe; Masoni, Paolo

    2014-04-01

    The purpose of this study is to propose a method for harmonising Life Cycle Assessment (LCA) literature studies on the same product or on different products fulfilling the same function for a reliable and meaningful comparison of their life-cycle environmental impacts. The method is divided in six main steps which aim to rationalize and quicken the efforts needed to carry out the comparison. The steps include: 1) a clear definition of the goal and scope of the review; 2) critical review of the references; 3) identification of significant parameters that have to be harmonised; 4) harmonisation of the parameters; 5) statistical analysis to support the comparison; 6) results and discussion. This approach was then applied to the comparative analysis of the published LCA studies on tap and bottled water production, focussing on Global Warming Potential (GWP) results, with the aim to identify the environmental preferable alternative. A statistical analysis with Wilcoxon's test confirmed that the difference between harmonised GWP values of tap and bottled water was significant. The results obtained from the comparison of the harmonised mean GWP results showed that tap water always has the best environmental performance, even in case of high energy-consuming technologies for drinking water treatments. The strength of the method is that it enables both performing a deep analysis of the LCA literature and obtaining more consistent comparisons across the published LCAs. For these reasons, it can be a valuable tool which provides useful information for both practitioners and decision makers. Finally, its application to the case study allowed both to supply a description of systems variability and to evaluate the importance of several key parameters for tap and bottled water production. The comparative review of LCA studies, with the inclusion of a statistical decision test, can validate and strengthen the final statements of the comparison. Copyright © 2014 Elsevier B.V. All

  6. Busting the Baby Teeth Myth and Increasing Children’s Consumption of Tap Water: Building Public Will for Children’s Oral Health in Colorado

    OpenAIRE

    Wyatt C. Hornsby; William Bailey; Patricia A. Braun; Karl Weiss; James Heichelbech

    2017-01-01

    Question Can a multifaceted statewide communications campaign motivate behavior change in low-income Colorado families to limit children’s fruit juice consumption and increase children’s consumption of tap water to prevent tooth decay? Purpose Caries is the most common chronic disease of childhood, affecting 40% of kindergartners and 55% of third graders in Colorado. Frequent consumption of 100% fruit juice is linked to childhood caries. The purpose of this campaign, “Cavities Get ...

  7. Relationship Between Growth of AIgae and Water Purification in a Slow Sand Filter in Summe

    OpenAIRE

    中本, 信忠; 池田, 大介; 田口, 香代; 山本, 満寿夫; 松田, 卓也

    1995-01-01

    The effects of water depth on the growth of algae and on the purification capacity of water in slow sand filters in summer were studied. Filamentous algae grew well in a shallow filter pond. The higher removal rates of available nutrients and dissolved organic carbon in a raw water were observed in the filteration of a shallow filter pond. Importance of algae as a nutrient assimilator and as an oxygen producer in the purification process was discussed.

  8. Water-resistant cellulosic filter for aerosol entrapment and water purification, Part I: production of water-resistant cellulosic filter.

    Science.gov (United States)

    Heydarifard, Solmaz; Nazhad, Mousa M; Xiao, Huining; Shipin, Oleg; Olson, James

    2016-01-01

    Synthetic filters are neither biodegradable nor produced from renewable sources. Thus, their disposal has serious environmental impacts. There is a growing desire to produce filters from cellulosic fibers that are renewable, biodegradable, cheap and most importantly recyclable if the contamination is removed. Foam-laid process in papermaking is a promising process for the production of specialty papers. Filters produced using this process are capable of providing products with high specific surface area and tortuous structure favorable for entrapping particulate matters, while providing excellent permeability for incoming gas or liquid. Although the end product fulfills completely the requirement of a filter in a dry environment, it fails completely if it is exposed to a moist environment. This work reports on converting the hydrophilic cellulosic filter into a hydrophobic product without disturbing its original structure.

  9. Prevalence of pathogenic free-living amoeba and other protozoa in natural and communal piped tap water from Queen Elizabeth protected area, Uganda.

    Science.gov (United States)

    Sente, Celsus; Erume, Joseph; Naigaga, Irene; Mulindwa, Julius; Ochwo, Sylvester; Magambo, Phillip Kimuda; Namara, Benigna Gabriela; Kato, Charles Drago; Sebyatika, George; Muwonge, Kevin; Ocaido, Michael

    2016-08-03

    Pathogenic water dwelling protozoa such as Acanthamoeba spp., Hartmannella spp., Naegleria spp., Cryptosporidium spp. and Giardia spp. are often responsible for devastating illnesses especially in children and immunocompromised individuals, yet their presence and prevalence in certain environment in sub-Saharan Africa is still unknown to most researchers, public health officials and medical practitioners. The objective of this study was to establish the presence and prevalence of pathogenic free-living amoeba (FLA), Cryptosporidium and Giardia in Queen Elizabeth Protected Area (QEPA). Samples were collected from communal taps and natural water sites in QEPA. Physical water parameters were measured in situ. The samples were processed to detect the presence of FLA trophozoites by xenic cultivation, Cryptosporidium oocysts by Ziehl-Neelsen stain and Giardia cysts by Zinc Sulphate floatation technique. Parasites were observed microscopically, identified, counted and recorded. For FLA, genomic DNA was extracted for amplification and sequencing. Both natural and tap water sources were contaminated with FLA, Cryptosporidium spp. and Giardia spp. All protozoan parasites were more abundant in the colder rainy season except for Harmannella spp. and Naegleria spp. which occurred more in the warmer months. The prevalence of all parasites was higher in tap water than in natural water samples. There was a strong negative correlation between the presence of Acanthamoeba spp., Hartmannella spp., Cryptosporidium spp. and Giardia spp. with Dissolved Oxygen (DO) (P protozoa that could possibly be the cause of a number of silent morbidities and mortalities among rural households in QEPA. This implies that water used by communities in QEPA is of poor quality and predisposes them to a variety of protozoan infections including the FLA whose public health importance was never reported, thus necessitating adoption of proper water safety measures.

  10. Filtering Water by Use of Ultrasonically Vibrated Nanotubes

    Science.gov (United States)

    Gavalas, Lillian Susan

    2009-01-01

    Devices that could be characterized as acoustically driven molecular sieves have been proposed for filtering water to remove all biological contaminants and all molecules larger than water molecules. Originally intended for purifying wastewater for reuse aboard spacecraft, these devices could also be attractive for use on Earth in numerous settings in which there are requirements to obtain potable, medical-grade, or otherwise pure water from contaminated water supplies. These devices could also serve as efficient means of removing some or all water from chemical products . for example, they might be useful as adjuncts or substitutes for stills in the removal of water from alcohols and alcoholic beverages. These devices may be constructed using various materials, such as ceramics, metallics, or polymers, depending on end-use requirements. A representative device of this type (see figure) would include a polymeric disk, about 1 mm in diameter and between 1 and 40 microns thick, within which would be embedded single-wall carbon nanotubes aligned along the thickness axis. The polymeric disk would be part of a unitary polymeric ring assembly. An acoustic transducer in the form of a piezoelectric-film-and-electrode subassembly - typically 9 microns thick and made of poly(vinylidene fluoride) coated with copper 150 nm thick -. would be affixed to the outside of the outer polymeric ring by means of an electrically nonconductive epoxy. The nanotubes would be chosen to have diameters between about 8 and about 13.5 A because water molecules could fit into the nanotubes, but larger molecules could not. Water to be purified would be placed in contact with one face (typically, the upper face) of the filter disk. The surface tension of water is low enough that water molecules should enter and travel along the nanotubes, and computational simulations of molecular dynamics and experimental measurements have shown that the water molecules inside the nanotubes in this size range can

  11. Experimental comparison of point-of-use filters for drinking water ultrafiltration.

    Science.gov (United States)

    Totaro, M; Valentini, P; Casini, B; Miccoli, M; Costa, A L; Baggiani, A

    2017-06-01

    Waterborne pathogens such as Pseudomonas spp. and Legionella spp. may persist in hospital water networks despite chemical disinfection. Point-of-use filtration represents a physical control measure that can be applied in high-risk areas to contain the exposure to such pathogens. New technologies have enabled an extension of filters' lifetimes and have made available faucet hollow-fibre filters for water ultrafiltration. To compare point-of-use filters applied to cold water within their period of validity. Faucet hollow-fibre filters (filter A), shower hollow-fibre filters (filter B) and faucet membrane filters (filter C) were contaminated in two different sets of tests with standard bacterial strains (Pseudomonas aeruginosa DSM 939 and Brevundimonas diminuta ATCC 19146) and installed at points-of-use. Every day, from each faucet, 100 L of water was flushed. Before and after flushing, 250 mL of water was collected and analysed for microbiology. There was a high capacity of microbial retention from filter C; filter B released only low Brevundimonas spp. counts; filter A showed poor retention of both micro-organisms. Hollow-fibre filters did not show good micro-organism retention. All point-of-use filters require an appropriate maintenance of structural parameters to ensure their efficiency. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  12. Different senescent HDPE pipe-risk: brief field investigation from source water to tap water in China (Changsha City).

    Science.gov (United States)

    Tang, Jing; Tang, Lin; Zhang, Chang; Zeng, Guangming; Deng, Yaocheng; Dong, Haoran; Wang, Jingjing; Wu, Yanan

    2015-10-01

    Semi-volatile organic compounds (SVOCs) derived from plastic pipes widely used in water distribution definitely influence our daily drinking water quality. There are still few scientific or integrated studies on the release and degradation of the migrating chemicals in pipelines. This investigation was carried out at field sites along a pipeline in Changsha, China. Two chemicals, 2, 4-tert-buthylphenol and 1, 3-diphenylguanidine, were found to be migrating from high density polyethylene (HDPE) pipe material. New pipes released more of these two compounds than older pipes, and microorganisms living in older pipes tended to degrade them faster, indicating that the aged pipes were safer for water transmission. Microorganism degradation in water plays a dominant role in the control of these substances. To minimize the potential harm to human, a more detailed study incorporating assessment of their risk should be carried out, along with seeking safer drinking pipes.

  13. Low Contribution of PbO2-Coated Lead Service Lines to Water Lead Contamination at the Tap

    Science.gov (United States)

    To determine if field experience corroborates that formation of stable PbO2 coatings on lead service lines (LSLs) provides an effective lead contamination control strategy, lead profile sampling was undertaken at eight home kitchen taps in three US cities (Newport, Rhode Island; ...

  14. Water risk assessment in China based on the improved Water Risk Filter

    Directory of Open Access Journals (Sweden)

    G. Hong

    2014-09-01

    Full Text Available Finding an effective way to deal with the water crisis and the relationship between water and development is a major issue for all levels of government and different economic sectors across the world. Scientific understanding of water risk is the basis for achieving a scientific relationship between water and development, and water risk assessment is currently an important research focus. To effectively deal with the global water crisis, the World Wide Fund for Nature and German Investment and Development Company Limited proposed the concept of water risk and released an online Water Risk Filter in March 2012, which has been applied to at least 85 countries. To comprehensively and accurately reflect the situation of water risk in China, this study adjusts the water risk assessment indicators in the Water Risk Filter, taking the actual situation in China and the difficulty of obtaining the information about the indicators into account, and proposes an index system for water risk evaluation for China which consists of physical risk, regulatory risk and reputational risk. The improved Water Risk Filter is further used to assess the sources and causes of the water risks in 10 first-class and seven second-class water resource areas (WRAs. The results indicate that the water risk for the whole country is generally medium and low, while those for different regions in the country vary greatly, and those for southern regions are generally lower than those for northern regions. Government regulatory and policy implementation as well as media supervision in northern regions should be strengthened to reduce the water risk. The research results may provide decision support and references for both governments and industrial enterprises in identifying water risks, formulating prevention and control policies, and improving water resources management in China.

  15. Water risk assessment in China based on the improved Water Risk Filter

    Science.gov (United States)

    Hong, G.; Yaqin, Q.; Qiong, L.; Cunwen, N.; Na, W.; Jiajia, L.; Jongde, G.; Na, Z.; Xiangyi, D.

    2014-09-01

    Finding an effective way to deal with the water crisis and the relationship between water and development is a major issue for all levels of government and different economic sectors across the world. Scientific understanding of water risk is the basis for achieving a scientific relationship between water and development, and water risk assessment is currently an important research focus. To effectively deal with the global water crisis, the World Wide Fund for Nature and German Investment and Development Company Limited proposed the concept of water risk and released an online Water Risk Filter in March 2012, which has been applied to at least 85 countries. To comprehensively and accurately reflect the situation of water risk in China, this study adjusts the water risk assessment indicators in the Water Risk Filter, taking the actual situation in China and the difficulty of obtaining the information about the indicators into account, and proposes an index system for water risk evaluation for China which consists of physical risk, regulatory risk and reputational risk. The improved Water Risk Filter is further used to assess the sources and causes of the water risks in 10 first-class and seven second-class water resource areas (WRAs). The results indicate that the water risk for the whole country is generally medium and low, while those for different regions in the country vary greatly, and those for southern regions are generally lower than those for northern regions. Government regulatory and policy implementation as well as media supervision in northern regions should be strengthened to reduce the water risk. The research results may provide decision support and references for both governments and industrial enterprises in identifying water risks, formulating prevention and control policies, and improving water resources management in China.

  16. Conductive Cotton Filters for Affordable and Efficient Water Purification

    Directory of Open Access Journals (Sweden)

    Fang Li

    2017-09-01

    Full Text Available It is highly desirable to develop affordable, energy-saving, and highly-effective technologies to alleviate the current water crisis. In this work, we reported a low-cost electrochemical filtration device composing of a conductive cotton filter anode and a Ti foil cathode. The device was operated by gravity feed. The conductive cotton filter anodes were fabricated by a facile dying method to incorporate carbon nanotubes (CNTs as fillers. The CNTs could serve as adsorbents for pollutants adsorption, as electrocatalysts for pollutants electrooxidation, and as conductive additives to render the cotton filters highly conductive. Cellulose-based cotton could serve as low-cost support to ‘host’ these CNTs. Upon application of external potential, the developed filtration device could not only achieve physically adsorption of organic compounds, but also chemically oxide these compounds on site. Three model organic compounds were employed to evaluate the oxidative capability of the device, i.e., ferrocyanide (a model single-electron-transfer electron donor, methyl orange (MO, a common recalcitrant azo-dye found in aqueous environments, and antibiotic tetracycline (TC, a common antibiotic released from the wastewater treatment plants. The devices exhibited a maximum electrooxidation flux of 0.37 mol/h/m2 for 5.0 mmol/L ferrocyanide, of 0.26 mol/h/m2 for 0.06 mmol/L MO, and of 0.9 mol/h/m2 for 0.2 mmol/L TC under given experimental conditions. The effects of several key operational parameters (e.g., total cell potential, CNT amount, and compound concentration on the device performance were also studied. This study could shed some light on the good design of effective and affordable water purification devices for point-of-use applications.

  17. Occurrence of immunosuppressive drugs and their metabolites in the sewage-impacted Vistula and Utrata Rivers and in tap water from the Warsaw region (Poland).

    Science.gov (United States)

    Giebułtowicz, Joanna; Nałęcz-Jawecki, Grzegorz

    2016-04-01

    Immunosuppresive therapy following organ transplant frequently includes treatment with tacrolimus and mycophenolic acid derivatives. These pharmaceuticals may enter the environment through wastewater treatment plant (WWTP) effluents and may have a potentially harmful effect on aquatic biota. Tacrolimus, mycophenolic acid and their metabolites were measured at specific points of a large Polish river (Vistula), a smaller river (Utrata) and in tap water samples from the Warsaw region. Analysis was performed using liquid chromatography tandem mass spectrometry, after solid phase extraction for water samples, or QuEChERS extraction for sediments. Residues of tacrolimus were below quantitation limits in both water and sediment samples. However, in water samples mycophenolic acid concentrations were measured at up to 180 ng L(-1) downstream of WWTP outfalls. No immunosuppressive drugs were detected in tap water. Concentrations of mycophenolic acid exceeded the predicted no effect concentration (PNEC) value in some Polish surface water, and risk calculations predicted at least twice higher concentrations in some other countries of the European Union. To the best of the authors' knowledge, this is the first report of these immunosuppressive drug concentrations in the environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Getting back on tap: the policy context and cost of ensuring access to low-cost drinking water in Massachusetts schools.

    Science.gov (United States)

    Cradock, Angie L; Wilking, Cara L; Olliges, Sarah A; Gortmaker, Steven L

    2012-09-01

    Adequate water intake may have important health benefits for schoolchildren. Layers of federal, state, and local policy are relevant to provision of water within schools. Recently passed state and federal laws require free drinking-water access for students during mealtimes. To review Massachusetts local district wellness policies related to water access, provide estimates of costs for three water-provision strategies, and discuss implications for policy relevant to adequate drinking-water access. Legal research was conducted using the LexisNexis legal database and government websites. Local wellness policies were double-coded using existing research tools. Costs of three water-delivery options were estimated using a 10-year school-district perspective. Prior to 2010, most Massachusetts public school district wellness policies (92%-94%) did not address access to free drinking water. Ten-year costs per school for providing water during mealtimes to students, including dispenser unit, installation, water testing, water, cups, and labor, range between $12,544 and $27,922 (depending on water-delivery option) assuming the average Massachusetts school enrollment. Water-provision strategies relying on tap water are more economical than bottled water in the long term. Policy recommendations and cost considerations deserve attention at the local, state, and federal levels. Recommendations are discussed to ensure access to safe, free drinking water for all students. Copyright © 2012 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  19. High-technology metals as emerging contaminants: Strong increase of anthropogenic gadolinium levels in tap water of Berlin, Germany, from 2009 to 2012

    International Nuclear Information System (INIS)

    Tepe, N.; Romero, M.; Bau, M.

    2014-01-01

    Highlights: • Monitoring study Berlin-2012 confirms tap water contamination with gadolinium. • Contamination confined to western districts of Berlin. • Strong increase of anthropogenic gadolinium from 2009 to 2012. • Anthropogenic gadolinium is tracer for wastewater-derived substances. - Abstract: The distribution of rare earth elements (REE) in tap water sampled in December 2012 in Berlin, Germany, is characterized by anomalously high levels of gadolinium (Gd). While the western districts of the city show strong anthropogenic positive Gd anomalies in REE distribution patterns, the eastern districts are (almost) unaffected. This contamination with anthropogenic Gd results from Gd-based contrast agents used in Magnetic Resonance Imaging, that enter rivers, groundwater and eventually tap water via the clear water effluent from wastewater treatment plants. While the spatial distribution of anthropogenic Gd in 2012 confirms results of an earlier study in 2009 (Kulaksiz and Bau, 2011a), anthropogenic Gd concentrations have increased between 1.5- and 11.5-fold in just three years. This confirms predictions based upon the increase of anthropogenic Gd concentrations in the Havel River over the past two decades and the time it takes the water to migrate from the Havel River to the groundwater production wells. Anomalously high levels of anthropogenic Gd in tap water, which are not confined to Berlin but have also been observed in London, U.K., and in German cities in the Ruhr area and along the Rhine River, reveal that high-technology metals have become emerging contaminants. While non-toxic at the observed concentrations, the anthropogenic Gd is a microcontaminant that may be used as a conservative pseudo-natural tracer for wastewater-derived xenobiotics such as pharmaceuticals, food additives and personal care products. Our results suggest that monitoring the concentrations of such substances in Berlin’s drinking water can be restricted to a few central and

  20. Identification, toxicity and control of iodinated disinfection byproducts in cooking with simulated chlor(am)inated tap water and iodized table salt.

    Science.gov (United States)

    Pan, Yang; Zhang, Xiangru; Li, Yu

    2016-01-01

    Chlorine/chloramine residuals are maintained in drinking water distribution systems to prevent microbial contamination and microorganism regrowth. During household cooking processes (e.g., soup making), the residual chlorine/chloramines in tap water may react with the iodide in iodized table salt to form hypoiodous acid, which could react with remaining natural organic matter in tap water and organic matter in food to generate iodinated disinfection byproducts (I-DBPs). However, I-DBPs formed during cooking with chloraminated/chlorinated tap water are almost completely new to researchers. In this work, by adopting precursor ion scan of m/z 127 using ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry, many new polar I-DBPs formed during cooking with chloraminated/chlorinated tap water were detected and proposed with structures, of which 3-iodo-4-hydroxybenzaldehyde, 3-iodo-4-hydroxybenzoic acid, 3-iodo-4-hydroxy-5-methylbenzoic acid, diiodoacetic acid, 3,5-diiodo-4-hydroxybenzaldehyde, 3,5-diiodo-4-hydroxybenzoic acid, 2,6-diiodo-4-nitrophenol, 2,4-diiodo-6-nitrophenol, and 2,4,6-triiodophenol were confirmed with standard compounds. With the aid of ultra fast liquid chromatography/ion trap-time of flight-mass spectrometry, molecular formula identification of five new I-DBPs (C8H5O4I, C7H4NO4I, C8H5O5I, C7H4NO5I, and C8H6O3I2) was achieved. A developmental toxicity with a recently developed sensitive bioassay was conducted for the newly identified I-DBPs, suggesting that phenolic I-DBPs (except for iodinated carboxyphenols) were about 50-200 times more developmentally toxic than aliphatic I-DBPs. The major I-DBPs in a baseline simulated cooking water sample were determined to be from 0.72 to 7.63 μg/L. Polar I-DBPs formed under various disinfection and cooking conditions were compared, and suggestions for controlling their formation were provided. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Enrichment of H(2)(17)O from tap water, characterization of the enriched water, and properties of several (17)O-labeled compounds.

    Science.gov (United States)

    Prasad, Brinda; Lewis, Andrew R; Plettner, Erika

    2011-01-01

    A low-abundance form of water, H(2)(17)O, was enriched from 0.04% to ∼90% by slow evaporation and fractional distillation of tap water. The density and refractive index for H(2)(17)O are reported. Gas chromatography-mass spectrometry (GC-MS) of (16)O- and (17)O-1-hexanols and their trimethyl silyl ethers and of (16)O- and (17)O-hexamethyl disiloxanes was used to determine the percentage of (17)O enrichment in the H(2)(17)O. Furthermore, the chemical shifts of labeled and nonlabeled water dissolved in CDCl(3) differed sufficiently that we could verify the enrichment of H(2)(17)O. (17)O hexanol was synthesized by the reaction of iodohexane with Na(17)OH. (17)O-Labeled trimethylsilanol and (17)O-labeled hexamethyldisiloxane were prepared by the reaction of H(2)(17)O with bis(trimethylsilyl)trifluoroacetamide (BSTFA). To generate standards for (17)O NMR, H(2)(17)O(2), and (17)O camphor were prepared. H(2)(17)O was electrolyzed to form (17)O-labeled hydrogen peroxide which was quantified using two colorimetric assays. (17)O-Labeled camphor was prepared by exchanging the ketone oxygen of camphor using H(2)(17)O. The (17)O-labeled compounds were characterized using (17)O, (1)H, and (13)C NMR and GC-MS. While we were characterizing the labeled camphor, we also detected an unexpected oxygen exchange reaction of primary alcohols, catalyzed by electrophilic ketones such as camphor. The reaction is a displacement of the alcohol OH group by water. This is an example of the usefulness of (17)O NMR in the study of a reaction mechanism that has not been noticed previously.

  2. Spatial distribution of orofacial cleft defect births in Harris County, Texas, 1990 to 1994, and historical evidence for the presence of low-level radioactivity in tap water.

    Science.gov (United States)

    Cech, Irina; Burau, Keith D; Walston, Jane

    2007-06-01

    While both ionizing and nonionizing radiation are known to impair human reproductive capacity, the role of low-level domestic radiation continues to be an unsettled issue. We examined the geostatistical distribution (residential longitude and latitude) of orofacial cleft birth cases adjusted for the underlying population distribution. Furthermore, we examined the cleft birth rates enumerated by zip codes for possible associations with levels of radium and radon in drinking water. Cleft births and unaffected live births in Harris County, Texas, from 1990 to 1994, were geocoded by residential addresses and tested for spatial clusters using the space-time clustering program SaTScan. Historical sample data on local variations in water quality facilitated the assessment of the association of orofacial cleft defect births with low-level radiation exposure. A cluster of significantly greater than expected numbers of cleft defect births was identified in northwest Harris County, (relative risk = 3.0, P = 0.043), where the presence of elevated levels of radium (> 3 pCi/L) and radon (> 300 pCi/L) in the tap water has been known since the 1980s. Despite the ecological design of the study, lacking individual exposure measurements for cleft birth residences, there was strong suggestive evidence of an association between elevated radiation levels in tap water and elevated cleft birth prevalence rates by zip codes. Attention of physicians is invited to environmental causes as potential risk factors for orofacial cleft. This would aid in genetic counseling and the development of future preventive measures.

  3. Effectiveness of table top water pitcher filters to remove arsenic from drinking water.

    Science.gov (United States)

    Barnaby, Roxanna; Liefeld, Amanda; Jackson, Brian P; Hampton, Thomas H; Stanton, Bruce A

    2017-10-01

    Arsenic contamination of drinking water is a serious threat to the health of hundreds of millions of people worldwide. In the United States ~3 million individuals drink well water that contains arsenic levels above the Environmental Protection Agency (EPA) maximum contaminant level (MCL) of 10μg/L. Several technologies are available to remove arsenic from well water including anion exchange, adsorptive media and reverse osmosis. In addition, bottled water is an alternative to drinking well water contaminated with arsenic. However, there are several drawbacks associated with these approaches including relatively high cost and, in the case of bottled water, the generation of plastic waste. In this study, we tested the ability of five tabletop water pitcher filters to remove arsenic from drinking water. We report that only one tabletop water pitcher filter tested, ZeroWater®, reduced the arsenic concentration, both As 3+ and As 5+ , from 1000μg/L to water and its use reduces plastic waste associated with bottled water. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Silver Nanoparticles (AgNP impregnated filters in drinking water disinfection

    Directory of Open Access Journals (Sweden)

    Rus Alexandru

    2017-01-01

    Full Text Available This paper describes how simple portable devices could eliminate water pathogens by using Silver Nanoparticles, based on their antimicrobial properties. Recent studies indicated that silver nanoparticles can achieve up to 100% antibacterial activity removal. Results are showing that Silver Nanoparticles retention in the filter structure, E. coli bacteria removal, water quality and water flow rate must be evaluated as main efficiency indicators of the designed filters, in order to obtain the optimal filter. To apply the antimicrobial property of Silver in drinking-water treatment, a filter is produced using Additive Manufacturing techniques and coated with different concentrations of silver solutions.

  5. Clinical and Microbiologic Efficacy of a Water Filter Program in a Rural Honduran Community

    Directory of Open Access Journals (Sweden)

    Jaclyn Arquiette

    2014-01-01

    Full Text Available Water purification in the rural Honduras is a focus of the nonprofit organization Honduras Outreach Medical Brigade Relief Effort (HOMBRE. We assessed water filter use and tested filter microbiologic and clinical efficacy. A 22-item questionnaire assessed water sources, obtainment/storage, purification, and incidence of gastrointestinal disease. Samples from home clay-based filters in La Hicaca were obtained and paired with surveys from the same home. We counted bacterial colonies of four bacterial classifications from each sample. Sixty-five surveys were completed. Forty-five (69% individuals used a filter. Fifteen respondents reported diarrhea in their home in the last 30 days; this incidence was higher in homes not using a filter. Thirty-three paired water samples and surveys were available. Twenty-eight samples (85% demonstrated bacterial growth. A control sample was obtained from the local river, the principal water source; number and bacterial colony types were innumerable within 24 hours. Access to clean water, the use of filters, and other treatment methods differed within a geographically proximal region. Although the majority of the water samples failed to achieve bacterial eradication, water filters may sufficiently reduce bacterial coliform counts to levels below infectious inoculation. Clay water filters may be sustainable water treatment measures in resource poor settings.

  6. A study of DNA damage in buccal cells of consumers of well- and/or tap-water using the comet assay: Assessment of occupational exposure to genotoxicants.

    Science.gov (United States)

    Vazquez Boucard, Celia; Lee-Cruz, Larisa; Mercier, Laurence; Ramírez Orozco, Martín; Serrano Pinto, Vania; Anguiano, Gerardo; Cazares, Linette; Díaz, Daniel

    2017-10-01

    Because of concerns that natural aquifers in the region of Todos Santos (Baja California Sur, Mexico) might be contaminated by organochlorine pesticides and heavy metals, a case-control study was conducted among consumers and non-consumers of well- and/or tap-water to determine risks to human health. This study was based on a genotoxic evaluation of buccal cells using the Comet assay technique. Levels of DNA damage in the consumers group were significantly higher than those of the control group. However, occupational exposure to genotoxicants showed to be the critical factor rather than water consumption. Taking into account the professions of well- and/or tap-water consumers, agricultural workers exposed directly (those who fumigated) or indirectly (those not involved in fumigating) to agrochemicals showed greater genetic damage than controls. This difference persisted even when age, and whether the person smoked or consumed alcoholic drinks were considered. These factors were not associated with the level of genetic damage observed. Chemical analyses of organochlorine pesticides and heavy metals were carried out to evaluate the water quality of wells, faucets, and surface water of canals consumed by the population and/or used for irrigation. High concentrations of α and β endosulfan were detected in water of surface canals. Although our inventory of agrochemicals employed in the region showed the use of products considered carcinogenic and/or mutagenic, they were not detected by the analytical techniques used. Heavy metals (arsenic, mercury, and lead) were detected in water of some wells used for irrigation and human consumption. Environ. Mol. Mutagen. 58:619-627, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  7. Preliminary analysis on the water quality index (WQI) of irradiated basic filter elements

    Science.gov (United States)

    Arif Abu Bakar, Asyraf; Muhamad Pauzi, Anas; Aziz Mohamed, Abdul; Syima Sharifuddin, Syazrin; Mohamad Idris, Faridah

    2018-01-01

    Simple water filtration system is needed in times of extreme floods. Clean water for sanitation at evacuation centres is essential and its production is possible by using the famous simple filtration system consisting of empty bottle and filter elements (sands, gravels, cotton/coffee filter). This research intends to study the effects of irradiated filter elements on the filtration effectiveness through experiments. The filter elements will be irradiated with gamma and neutron radiation using the facilities available at Malaysia Nuclear Agency. The filtration effectiveness is measured using the water quality index (WQI) that is developed in this study to reflect the quality of filtered water. The WQI of the filtered water using the system with irradiated filter elements is then compared with that of the system with non-irradiated filter elements. This preliminary analysis only focus on filtration element of silica sand. Results shows very nominal variation in in WQI after filtered by non-irradiated, gamma and neutron filter element (silica sand), where the hypothesis could not be affirmed.

  8. Processes of microbial pesticide degradation in rapid sand filters for treatment of drinking water

    DEFF Research Database (Denmark)

    Hedegaard, Mathilde Jørgensen; Albrechtsen, Hans-Jørgen

    Aerobic rapid sand filters for treatment of groundwater at waterworks were investigated for the ability to remove pesticides. The potential, kinetics and mechanisms of microbial pesticide removal was investigated in microcosms consisting of filter sand, treated water and pesticides in initial...... concentrations of 0.04-2.4 μg/L. The pesticides were removed from the water in microcosms with filter sand from all three investigated sand filters. Within the experimental periode of six to 13 days, 65-85% of the bentazone, 86-93% of the glyphosate, 97-99% of the p-nitrophenol was removed from the water phase...

  9. Stratification of nitrification activity in rapid sand filters for drinking water treatment

    DEFF Research Database (Denmark)

    Tatari, Karolina; Smets, Barth F.; Musovic, Sanin

    2013-01-01

    Rapid sand filters used in groundwater treatment remove ammonium, iron and manganese from the water. Ammonium is removed biologically by nitrifying microorganisms attached on the sand surface. Nitrification kinetics and activity is strongly affected by filter design and operation, which are the key...... parameters in process optimization. Nitrification optimization needs a detailed insight of the process and the way it takes place in the filter. Filters are often considered in a “black box” approach, where data are only available for influent and effluent and the entire filter is assumed homogenous. The aim...... of this study is to investigate nitrification activity in a rapid sand filter, with focus on its homogeneity and how it relates to filter performance. Two groundwater treatment plants in Denmark were selected for the experimental investigations. Plant 1 operates a single line of pre and after filters and has...

  10. Tunable, Strain-Controlled Nanoporous MoS₂ Filter for Water Desalination.

    Science.gov (United States)

    Li, Weifeng; Yang, Yanmei; Weber, Jeffrey K; Zhang, Gang; Zhou, Ruhong

    2016-02-23

    The deteriorating state of global fresh water resources represents one of the most serious challenges that scientists and policymakers currently face. Desalination technologies, which are designed to extract potable water from the planet's bountiful stores of seawater, could serve to alleviate much of the stress that presently plagues fresh water supplies. In recent decades, desalination methods have improved via water-filtering architectures based on nanoporous graphene filters and artificial membranes integrated with biological water channels. Here, we report the auspicious performance (in simulations) of an alternative nanoporous desalination filter constructed from a MoS2 nanosheet. In striking contrast to graphene-based filters, we find that the "open" and "closed" states of the MoS2 filter can be regulated by the introduction of mechanical strain, yielding a highly tunable nanopore interface. By applying lateral strain to the MoS2 filter in our simulations, we see that the transition point between "open" and "closed" states occurs under tension that induces about 6% cross-sectional expansion in the membrane (6% strain); the open state of the MoS2 filter demonstrates high water transparency and a strong salt filtering capability even under 12% strain. Our results thus demonstrate the promise of a controllable nanoporous MoS2 desalination filter, wherein the morphology and size of the central nanopore can be precisely regulated by tensile strain. These findings support the design and proliferation of tunable nanodevices for filtration and other applications.

  11. Phosphate removal from agricultural drainage water using an iron oxyhydroxide filter material

    Science.gov (United States)

    Phosphate discharged with agricultural drainage causes water quality degradation on local, regional, and national scales. Iron oxyhydroxide filter materials can potentially remove the soluble phosphate present in drainage waters. Laboratory saturated column experiments and preliminary small-scale ...

  12. Characterization of a Large Area ZnS(Ag) Detector for Gross Alpha and Beta Activity Measurements in Tap Water Plants

    Science.gov (United States)

    Bodewits, E.; Cester, D.; Lunardon, M.; Moretto, S.; Schotanus, P.; Stevanato, L.; Viesti, G.

    2016-06-01

    In this work we present the characterization of a large area 200 mm ×200 mm EJ-444 scintillation detector to be used for monitoring gross alpha and beta activity in tap water plants. Specific tests were performed in order to determine the best setup to read-out the light from the detector side. The possibility to stack many detectors and get a compact device with total active area of the order of 1 m2 has been explored. Alpha/beta discrimination, efficiency and homogeneity tests were carried out with alpha and beta sources. Background from ambient radioactivity was measured as well. Alpha/beta real-time monitoring in drinking water is a goal of the EU project TAWARA_RTM.

  13. Performance of water filters towards the removal of selected ...

    African Journals Online (AJOL)

    Organic matter removal was found to be 47%, 43%, 53%, 43.4% for bio-sand, slow sand, ceramic and membrane purifier respectively, while, fluoride removal was found to be 95.5% for bone char filter. Furthermore, filters were also assessed in terms of media availability, buying costs, operation, benefits/ effectiveness ...

  14. Storm Water Pollution Removal Performance of Compost Filter Socks

    Science.gov (United States)

    In 2005, the US Environmental Protection Agency National Menu of Best Management Practices (BMPs) listed compost filter socks as an approved BMP for controlling sediment in storm runoff on construction sites. Filtrexx International manufactures and distributes Filter Soxx (FS). Literature suggests...

  15. REMOVING BIOMASS FROM WATER PONDS AND SMALL WATER RESERVOIRS BY USING NON-WOVEN FILTERS

    OpenAIRE

    Jakub Nieć; Marcin Spychała; Agnieszka Ewa Ławniczak; Natalia Walczak

    2015-01-01

    Small water bodies, for example garden ponds, play many functions in the environment, including biocenotic, hydrological, climatic, sozological, landfill-creative, and aesthetic. Due to their small size, these reservoirs are sensitive to external and internal factors, they are also a common natural contaminants receivers. Nonwoven filters have been investigated for several years as a useful device for treatment of domestic wastewater pre-treated in a septic tank. The aim of this study was to ...

  16. Biofouling reduction for improvement of depth water filtration. Filter production and testing

    Directory of Open Access Journals (Sweden)

    Sztuk - Sikorska Ewa

    2016-09-01

    Full Text Available Water is a strategic material. Recycling is an important component of balancing its use. Deep-bed filtration is an inexpensive purification method and seems to be very effective in spreading water recovery. Good filter designs, such as the fibrous filter, have high separation efficiency, low resistance for the up-flowing fluid and high retention capacity. However, one of the substantial problems of this process is the biofouling of the filter. Biofouling causes clogging and greatly reduces the life of the filter. Therefore, the melt-blown technique was used for the formation of novel antibacterial fibrous filters. Such filters are made of polypropylene composites with zinc oxide and silver nanoparticles on the fiber surface. These components act as inhibitors of bacterial growth in the filter and were tested in laboratory and full scale experiments. Antibacterial/bacteriostatic tests were performed on Petri dishes with E. coli and B. subtilis. Full scale experiments were performed on natural river water, which contained abiotic particles and mutualistic bacteria. The filter performance at industrial scale conditions was measured using a particle counter, a flow cytometer and a confocal microscope. The results of the experiments indicate a significant improvement of the composite filter performance compared to the regular fibrous filter. The differences were mostly due to a reduction in the biofouling effect.

  17. Results from measurements of natural radiation in and from filters in some water treatment plants; Maetningar av naturlig radioaktivitet i och fraan filter vid naagra vattenverk

    Energy Technology Data Exchange (ETDEWEB)

    Oestergren, Inger; Aakerblom, Gustav [Swedish Radiation Protection Authority, Stockholm (Sweden); Ek, Britt-Marie [Geological Survey of Sweden, Uppsala (Sweden)

    2005-07-01

    Large water treatment plants often process surface water where the concentration of natural radionuclides is so low that treatment of the water produces no radiation dose or waste problem. The level of natural radionuclides in ground water is higher than in surface water and often so high that mitigation is needed to clean the water. Specific treatment of the filters and filter masses is needed in some cases because the natural radionuclides precipitate in the filters. The radiation doses received by personnel at the ground water treatment plants are often low because of the relatively short time the workers spend inside the treatment plant. The results presented here indicate no need for extra action to insure radiation protection with regard to radioactivity inside the treatment plant or during processing of the filters and waste. A comprehensive discussion of the problems associated with the concentrating of natural radionuclides in water filters is presented in this report.

  18. Busting the Baby Teeth Myth and Increasing Children's Consumption of Tap Water: Building Public Will for Children's Oral Health in Colorado.

    Science.gov (United States)

    Hornsby, Wyatt C; Bailey, William; Braun, Patricia A; Weiss, Karl; Heichelbech, James

    2017-01-01

    Can a multifaceted statewide communications campaign motivate behavior change in low-income Colorado families to limit children's fruit juice consumption and increase children's consumption of tap water to prevent tooth decay? Caries is the most common chronic disease of childhood, affecting 40% of kindergartners and 55% of third graders in Colorado. Frequent consumption of 100% fruit juice is linked to childhood caries. The purpose of this campaign, "Cavities Get Around," was to motivate families to limit children's fruit juice consumption and increase consumption of tap water to protect baby teeth from caries, while also building public will for children's oral health. The campaign included targeted media, promotores/organizers, and family education. We focused on fruit juice because audience research showed many families view fruit juice as healthy, and it is also a common beverage among young children up to age of 6 years. We also focused on low-socioeconomic status families because data show higher childhood tooth decay rates in this population. To evaluate progress, we conducted identical pre- and post-surveys, each of 600 random low-income parents contacted by landline, mobile telephone, and Internet, allowing for comparative data. Significant progress was achieved compared to 2014 baseline results. Findings from a November 2015 statewide survey of parents included the following: (1) 22-point increase from 2014 in percentage of children regularly drinking tap water (from 41 to 63%). (2) 29-point decrease from 2014 in percentage of respondents who considered fruit juice consumption important to their child's health and nutritional needs (from 72 to 43%). (3) 19-point reduction in fruit juice consumption among young children (from 66% in 2014 to 47% in 2015). (4) 6-point reduction in percentage of parents considering baby teeth "less important" than adult teeth (from 21% in 2014 to 15% in 2015). The campaign also played a role in new state rules prohibiting

  19. Busting the Baby Teeth Myth and Increasing Children’s Consumption of Tap Water: Building Public Will for Children’s Oral Health in Colorado

    Directory of Open Access Journals (Sweden)

    Wyatt C. Hornsby

    2017-09-01

    Full Text Available QuestionCan a multifaceted statewide communications campaign motivate behavior change in low-income Colorado families to limit children’s fruit juice consumption and increase children’s consumption of tap water to prevent tooth decay?PurposeCaries is the most common chronic disease of childhood, affecting 40% of kindergartners and 55% of third graders in Colorado. Frequent consumption of 100% fruit juice is linked to childhood caries. The purpose of this campaign, “Cavities Get Around,” was to motivate families to limit children’s fruit juice consumption and increase consumption of tap water to protect baby teeth from caries, while also building public will for children’s oral health.MethodsThe campaign included targeted media, promotores/organizers, and family education. We focused on fruit juice because audience research showed many families view fruit juice as healthy, and it is also a common beverage among young children up to age of 6 years. We also focused on low-socioeconomic status families because data show higher childhood tooth decay rates in this population. To evaluate progress, we conducted identical pre- and post-surveys, each of 600 random low-income parents contacted by landline, mobile telephone, and Internet, allowing for comparative data.ResultsSignificant progress was achieved compared to 2014 baseline results. Findings from a November 2015 statewide survey of parents included the following: (1 22-point increase from 2014 in percentage of children regularly drinking tap water (from 41 to 63%. (2 29-point decrease from 2014 in percentage of respondents who considered fruit juice consumption important to their child’s health and nutritional needs (from 72 to 43%. (3 19-point reduction in fruit juice consumption among young children (from 66% in 2014 to 47% in 2015. (4 6-point reduction in percentage of parents considering baby teeth “less important” than adult teeth (from 21% in 2014 to 15% in 2015. The

  20. Development and characterization of ultra lightweight, highly selective, filter media for oil-water mixtures

    Science.gov (United States)

    Baghernejad, Lida

    Emulsions formed by oil-water mixtures can cause serious issues at different stages of crude oil production, produced water remediation, and oil spills. Efficient, cost-effective processes for separation of oil--water emulsions or dispersions are critical and highly desirable. Filters are among the most common means employed to separate oil-water emulsions into their corresponding components. To conduct single step gravity-based or centrifugal separation of oil--water mixtures into their pure phase, it is essential that the filter be hydrophilic and oleophobic both in air and water. The filter medium should also have high surface porosity, which affects the rate of permeation of one phase. It should be stable at operating temperatures and pressures and be resistant to degradation by chemicals in the feed stream. Favorable oil rejection characteristics, resistance to fouling by organic and inorganic foulants and low cost of production are also important. The goal of this project is to develop ultra-lightweight filters that are durable, highly porous and able to selectively separate oil-water mixtures, from non-woven cellulose based materials by electrospinning. Since electrospinning is a cost-effective, scalable method that can be used to fabricate filters with very thin nanoscale fibers and nano-dimension pores, and cellulose is a very cheap and abundant ingredient, these filters may be considered as novel tools for efficient, cost-effective separation of oil-water emulsions in industry. Currently there is a growing demand for highly porous selective filters for oil-water mixtures in the petroleum industry. These filters are beneficial to both manufacturers and consumers. This research focuses on the development and characterization of the new filter material and evaluation of its suitability for oil-water separation in the field.

  1. A New Method for the Deposition of Metallic Silver on Porous Ceramic Water Filters

    Directory of Open Access Journals (Sweden)

    Kathryn N. Jackson

    2018-01-01

    Full Text Available A new method of silver application to a porous ceramic water filter used for point-of-use water treatment is developed. We evaluated filter performance for filters manufactured by the conventional method of painting an aqueous suspension of silver nanoparticles onto the filter and filters manufactured with a new method that applies silver nitrate to the clay-water-sawdust mixture prior to pressing and firing the filter. Filters were evaluated using miscible displacement flow-through experiments with pulse and continuous-feed injections of E. coli. Flow characteristics were quantified by tracer experiments using [3H]H2O. Experiments using pulse injections of E. coli showed similar performance in breakthrough curves between the two application methods. Long-term challenge tests performed with a continuous feed of E. coli and growth medium resulted in similar log removal rates, but the removal rate by nanosilver filters decreased over time. Silver nitrate filters provided consistent removal with lower silver levels in the effluent and effective bacterial disinfection. Results from continued use with synthetic groundwater over 4 weeks, with a pulse injection of E. coli at 2 and 4 weeks, support similar conclusions—nanosilver filters perform better initially, but after 4 weeks of use, nanosilver filters suffer larger decreases in performance. Results show that including silver nitrate in the mixing step may effectively reduce costs, improve silver retention in the filter, increase effective lifespan, and maintain effective pathogen removal while also eliminating the risk of exposure to inhalation of silver nanoparticles by workers in developing-world filter production facilities.

  2. Application of biological filters in water treatment systems

    Science.gov (United States)

    Hurley, T. L.; Bambenek, R. A.

    1973-01-01

    Silver chloride placed on or close to barrier kills bacteria as they arrive. Dead bacteria accumulate linearly, whereas previously, live bacteria accumulated exponentially. During continuous 30-day tests, no bacteriological contamination was found downstream of filters with silver chloride added.

  3. Making Fe0-Based Filters a Universal Solution for Safe Drinking Water Provision

    Directory of Open Access Journals (Sweden)

    Elham Naseri

    2017-07-01

    Full Text Available Metallic iron (Fe0-based filtration systems have the potential to significantly contribute to the achievement of the United Nations (UN Sustainable Development Goals (SDGs of substantially improving the human condition by 2030 through the provision of clean water. Recent knowledge on Fe0-based safe drinking water filters is addressed herein. They are categorized into two types: Household and community filters. Design criteria are recalled and operational details are given. Scientists are invited to co-develop knowledge enabling the exploitation of the great potential of Fe0 filters for sustainable safe drinking water provision (and sanitation.

  4. Isolation and identification of pathogenic free-living amoeba from surface and tap water of Shiraz City using morphological and molecular methods.

    Science.gov (United States)

    Armand, B; Motazedian, M H; Asgari, Q

    2016-01-01

    Free-living amoebae (FLA) are the most abundant and widely distributed protozoa in the environment. An investigation was conducted to determine the presence of free-living amoebae (FLA), Acanthamoeba and Vermamoeba in waterfronts of parks and squares and tap water of Shiraz City, Iran. FLA are considered pathogenic for human. These ubiquitous organisms have been isolated from different environments such as water, soil, and air. Eighty-two water samples were collected from different places of Shiraz City during the summer of 2013. All samples were processed in Dept. of Parasitology and Mycology, Shiraz University of Medical Sciences, Fars, Iran. Samples were screened for FLA and identified by morphological characters in the cultures, PCR amplification targeting specific genes for each genus and sequencing determined frequent species and genotypes base on NCBI database. Overall, 48 samples were positive for Acanthamoeba and Vermamoeba in non-nutrient agar culture based on morphological characteristics. The PCR examination was done successfully. Sequencing results were revealed T4 (62.96 %) genotypes as the most common genotype of Acanthamoeba in the Shiraz water sources. In addition, T5 (33.33 %) and T15 (3.71 %) were isolated from water supplies. Vermamoeba vermiformis was known the dominant species from this genus. The high frequency of Acanthamoeba spp. and Vermamoeba in different environmental water sources of Shiraz is an alert for the public health related to water sources. The result highlights a need for taking more attention to water supplies in order to prevent illnesses related to free-living amoebae.

  5. Functionalization and formation of drinking water filter rod from lignite with zeolite, bentonite, and clay

    Directory of Open Access Journals (Sweden)

    Sumrit Mopoung

    2016-03-01

    Full Text Available A drinking water filter rod was functionalized and formed from a starting mixture of lignite, zeolite, bentonite, and clay. The formation of the filter was studied focusing on the effects of zeolite dosage and sintering temperature in a reducing atmosphere. The sintered filters were characterized by XRD, FTIR, and SEM-EDS. The physical and chemical properties of filters were measured. The results showed that the firing shrinkage, the total shrinkage and hardness increased with increasing sintering temperature. However, mass yield and fixed carbon decreased with increasing sintering temperature. The functional surface groups of the sintered filter exhibited a high content of aluminosilicates and carbon, which were derived from all starting materials. The macropores of sintered filter had dimensions of the channels between particles in the range of 0.2-2 µm.

  6. Copper deficiency can limit nitrification in biological rapid sand filters for drinking water production

    DEFF Research Database (Denmark)

    Wagner, Florian Benedikt; Nielsen, Peter Borch; Boe-Hansen, Rasmus

    2016-01-01

    enzymes in nitrification, we investigated the effect of copper dosing on nitrification in different biological rapid sand filters treating groundwater. A lab-scale column assay with filter material from a water works demonstrated that addition of a trace metal mixture, including copper, increased ammonium......Incomplete nitrification in biological filters during drinking water treatment is problematic, as it compromises drinking water quality. Nitrification problems can be caused by a lack of nutrients for the nitrifying microorganisms. Since copper is an important element in one of the essential...... removal compared to a control without addition. Subsequently, another water works was investigated in full-scale, where copper influent concentrations were below 0.05 μg Cu L-1 and nitrification was incomplete. Copper dosing of less than 5 μg Cu L-1 to a full-scale filter stimulated ammonium removal...

  7. Copper deficiency can limit nitrification in biological rapid sand filters for drinking water production

    DEFF Research Database (Denmark)

    Wagner, Florian Benedikt; Nielsen, Peter Borch; Boe-Hansen, Rasmus

    2016-01-01

    Incomplete nitrification in biological filters during drinking water treatment is problematic, as it compromises drinking water quality. Nitrification problems can be caused by a lack of nutrients for the nitrifying microorganisms. Since copper is an important element in one of the essential...... enzymes in nitrification, we investigated the effect of copper dosing on nitrification in different biological rapid sand filters treating groundwater. A lab-scale column assay with filter material from a water works demonstrated that addition of a trace metal mixture, including copper, increased ammonium...... removal compared to a control without addition. Subsequently, another water works was investigated in full-scale, where copper influent concentrations were below 0.05 μg Cu L-1 and nitrification was incomplete. Copper dosing of less than 5 μg Cu L-1 to a full-scale filter stimulated ammonium removal...

  8. Performance of non woven synthetic fabric and disc filters for fertirrigation water treatment

    OpenAIRE

    Ribeiro,Túlio Assunção Pires; Paterniani,José Euclides Stipp; Airoldi,Rogério Pereira da Silva; Silva,Marcelo Jacomini Moreira da

    2004-01-01

    Obstruction of emitters caused by the presence of solid particles in the water raises the cost and maintenance of trickle irrigation systems, and might compromise their utilization. This research was performed through test fields, with the objective of evaluating the performance of a disc filter (130 microns) and a non woven synthetic fabric filter on the removal of physical, chemical and biological impurities from the irrigation water, which may cause emitter obstruction during fertirrigatio...

  9. Technical Assistance Plan (TAP)

    Science.gov (United States)

    A Technical Assistance Plan (TAP) enables community groups to retain the services of an independent technical advisor and to provide resources for a community group to help inform other community members about site decisions.

  10. Propeller TAP flap

    DEFF Research Database (Denmark)

    Thomsen, Jørn Bo; Bille, Camilla; Wamberg, Peter

    2013-01-01

    The aim of this study was to examine if a propeller thoracodorsal artery perforator (TAP) flap can be used for breast reconstruction. Fifteen women were reconstructed using a propeller TAP flap, an implant, and an ADM. Preoperative colour Doppler ultrasonography was used for patient selection...... to identify the dominant perforator in all cases. A total of 16 TAP flaps were performed; 12 flaps were based on one perforator and four were based on two. A permanent silicone implant was used in 14 cases and an expander implant in two. Minor complications were registered in three patients. Two cases had...... major complications needing additional surgery. One flap was lost due to a vascular problem. Breast reconstruction can be performed by a propeller TAP flap without cutting the descending branch of the thoracodorsal vessels. However, the authors would recommend that a small cuff of muscle is left around...

  11. Separation and determination of trace amounts of zinc, lead, cadmium and mercury in tap and Qaroun lake water using polyurethane foam functionalized with 4-hydroxytoluene and 4-hydroxyacetophenone

    Energy Technology Data Exchange (ETDEWEB)

    Burham, N. [Chemistry Department, Faculty of Science, Fayoum University, Fayoum City (Egypt)]. E-mail: n_burham@yahoo.com; Abdel-Azeem, S.M. [Chemistry Department, Faculty of Science, Fayoum University, Fayoum City (Egypt); El-Shahat, M.F. [Chemistry Department, Faculty of Science, Ain-Shams University, Cairo (Egypt)

    2006-10-10

    A stable chelating sorbent was synthesized by covalently linking 4-hydroxytoluene or 4-hydroxyacetophenone with the polyurethane foam (PUF) through -N=N- group. The synthesized chelating sorbents were characterized by IR and UV/vis measurements. The modified foams show excellent stability towards various solvents. Factors influencing the extraction process of Zn(II), Pb(II), Cd(II) and Hg(II) were studied and evaluated as a function of pH of metal ion solution and equilibration shaking time. The values of sorption capacity of metal ions ({mu}g g{sup -1}) were determined with the two types of bonded foams. The two phenolic bonded foams were studied comparatively. The potential applications of the two newly synthesized foams for the removal and separation of the examined metal ions from two natural water samples (drinking tap water and Qaroun lake water at Fayoum City, Egypt) were investigated. Precision (assessed as a relative standard deviation, R.S.D.) was also evaluated and found to be {<=}7.3% (N = 5) with a detection limit under 0.46 {mu}g L{sup -1}.

  12. Separation and determination of trace amounts of zinc, lead, cadmium and mercury in tap and Qaroun lake water using polyurethane foam functionalized with 4-hydroxytoluene and 4-hydroxyacetophenone

    International Nuclear Information System (INIS)

    Burham, N.; Abdel-Azeem, S.M.; El-Shahat, M.F.

    2006-01-01

    A stable chelating sorbent was synthesized by covalently linking 4-hydroxytoluene or 4-hydroxyacetophenone with the polyurethane foam (PUF) through -N=N- group. The synthesized chelating sorbents were characterized by IR and UV/vis measurements. The modified foams show excellent stability towards various solvents. Factors influencing the extraction process of Zn(II), Pb(II), Cd(II) and Hg(II) were studied and evaluated as a function of pH of metal ion solution and equilibration shaking time. The values of sorption capacity of metal ions (μg g -1 ) were determined with the two types of bonded foams. The two phenolic bonded foams were studied comparatively. The potential applications of the two newly synthesized foams for the removal and separation of the examined metal ions from two natural water samples (drinking tap water and Qaroun lake water at Fayoum City, Egypt) were investigated. Precision (assessed as a relative standard deviation, R.S.D.) was also evaluated and found to be ≤7.3% (N = 5) with a detection limit under 0.46 μg L -1

  13. Annual variations and effects of temperature on Legionella spp. and other potential opportunistic pathogens in tap and shower water

    Data.gov (United States)

    U.S. Environmental Protection Agency — The data contained in this worksheet provides the quantitative detection of potential pathogens for the bathroom water samples used in this study. This dataset is...

  14. Modeling Flow Rate to Estimate Hydraulic Conductivity in a Parabolic Ceramic Water Filter

    Directory of Open Access Journals (Sweden)

    Ileana Wald

    2012-01-01

    Full Text Available In this project we model volumetric flow rate through a parabolic ceramic water filter (CWF to determine how quickly it can process water while still improving its quality. The volumetric flow rate is dependent upon the pore size of the filter, the surface area, and the height of water in the filter (hydraulic head. We derive differential equations governing this flow from the conservation of mass principle and Darcy's Law and find the flow rate with respect to time. We then use methods of calculus to find optimal specifications for the filter. This work is related to the research conducted in Dr. James R. Mihelcic's Civil and Environmental Engineering Lab at USF.

  15. Removal naturally occurring radionuclides from drinking water using a filter specifically designed for Drinking Water Treatment Plants.

    Science.gov (United States)

    Baeza, A; Salas, A; Guillén, J; Muñoz-Serrano, A; Ontalba-Salamanca, M Á; Jiménez-Ramos, M C

    2017-01-01

    The occurrence of naturally occurring radionuclides in drinking water can pose health hazards in some populations, especially taking into account that routine procedures in Drinking Water Treatment Plants (DWTPs) are normally unable to remove them efficiently from drinking water. In fact, these procedures are practically transparent to them, and in particular to radium. In this paper, the characterization and capabilities of a patented filter designed to remove radium from drinking water with high efficiency is described. This filter is based on a sandwich structure of silica and green sand, with a natural high content manganese oxide. Both sands are authorized by Spanish authorities to be used in Drinking Water Treatment Plants. The Mn distribution in the green sand was found to be homogenous, thus providing a great number of adsorption sites for radium. Kinetic studies showed that the 226 Ra adsorption on green sand was influenced by the content of major cations solved in the treated water, but the saturation level, about 96-99%, was not affected by it. The physico-chemical parameters of the treated water were unaltered by the filter. The efficiency of the filter for the removal of 226 Ra remained unchanged with large water volumes passed through it, proving its potential use in DWTP. This filter was also able to remove initially the uranium content due to the presence of Fe 2 O 3 particles in it, although it is saturated faster than radium. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Microbial pesticide removal in rapid sand filters for drinking water treatment – Potential and kinetics

    DEFF Research Database (Denmark)

    Hedegaard, Mathilde Jørgensen; Albrechtsen, Hans-Jørgen

    2014-01-01

    Filter sand samples, taken from aerobic rapid sand filters used for treating groundwater at three Danish waterworks, were investigated for their pesticide removal potential and to assess the kinetics of the removal process. Microcosms were set up with filter sand, treated water, and the pesticides...... or metabolites mecoprop (MCPP), bentazone, glyphosate and p-nitrophenol were applied in initial concentrations of 0.03–2.4 μg/L. In all the investigated waterworks the concentration of pesticides in the water decreased – MCPP decreased to 42–85%, bentazone to 15–35%, glyphosate to 7–14% and p-nitrophenol 1....../L) increased from 0.21%/g filter sand to 0.75%/g filter sand, when oxygen availability was increased from 0.28 mg O2/g filter sand to 1.09 mg O2/g filter sand. Bentazone was initially cleaved in the removal process. A metabolite, which contained the carbonyl group, was removed rapidly from the water phase...

  17. Assessment of crushed-recycled glass as filter media for drinking water treatment

    International Nuclear Information System (INIS)

    Rutledge, S.O.; Fahie, C.; Gagnon, G.A.

    2002-01-01

    The objective of this project was to evaluate the performance of a pressure filter utilizing crushed glass as the filter media. The performance of the crushed glass filter was compared to that of a sand filter. The research was conducted in Orangedale, Nova Scotia, which is a small community of with a population of approximately 500. Orangedale is located on the south shore of Bras d'Or Lakes and feeds into Miller Pond, which serves as the source the of drinking water. The Orangedale treatment plant produces an average daily flow of 35 m3/d (6.4-gpm). The treatment plant consists of coagulation (sodium aluminate and polyaluminum chloride), flocculation, dissolved air flotation (DAF), disinfection with sodium hypochlorite and dual-media filtration with anthracite and sand. In general, the particle removal capabilities of the crushed glass filter were slightly poorer than that of a sand filter, as quantified in a field application in the community of Orangedale, Nova Scotia. It was found that the crushed glass used in this project had a higher angularity and slightly higher uniformity coefficient. During initial start-up the performance of the crushed glass filter was more variable and appeared to improve as the glass began to wear. After six-months of use the crushed glass filter was able to produce a very consistent filter effluent that was only slightly greater than the silica sand filter. After six-months of use, the sand filter achieved a 1.6 log-removal of particles with diameters greater than 2 μm; whereas the crushed glass filter achieved a 1.4 log removal for the similar particle size range. The observed removal performance was particularly encouraging given that the sand used had properties that were consistent with the standards set by the American Water Works Association. The crushed glass filter media was initially sieved and washed, but had no other pre-treatment preparation. Thus the application of crushed glass shows considerable promise as filter

  18. Evaluating the sustainability of ceramic filters for point-of-use drinking water treatment.

    Science.gov (United States)

    Ren, Dianjun; Colosi, Lisa M; Smith, James A

    2013-10-01

    This study evaluates the social, economic, and environmental sustainability of ceramic filters impregnated with silver nanoparticles for point-of-use (POU) drinking water treatment in developing countries. The functional unit for this analysis was the amount of water consumed by a typical household over ten years (37,960 L), as delivered by either the POU technology or a centralized water treatment and distribution system. Results indicate that the ceramic filters are 3-6 times more cost-effective than the centralized water system for reduction of waterborne diarrheal illness among the general population and children under five. The ceramic filters also exhibit better environmental performance for four of five evaluated life cycle impacts: energy use, water use, global warming potential, and particulate matter emissions (PM10). For smog formation potential, the centralized system is preferable to the ceramic filter POU technology. This convergence of social, economic, and environmental criteria offers clear indication that the ceramic filter POU technology is a more sustainable choice for drinking water treatment in developing countries than the centralized treatment systems that have been widely adopted in industrialized countries.

  19. Educational Concerns of Implementing Biosand Water Filters in Rural Uganda

    Science.gov (United States)

    Spowart, Matthew

    2012-01-01

    The world is facing a shortage of clean drinking water. Current predictions, due to growing population, urbanization, and climate change estimate access to clean water to be further challenged in the coming years. Research has indicated that point of use (POU) technologies are likely to be the most efficient at delivering clean water (water…

  20. Synergistic Water-Treatment Reactors Using a TiO2-Modified Ti-Mesh Filter

    OpenAIRE

    Akira Fujishima; Yuko Morito; Masahiko Ikekita; Tomonori Suzuki; Masayuki Hara; Yasuhiro Nojima; Ryuichi Nakano; Kazuya Nakata; Shoko Tago; Ken Masuko; Tsuyoshi Ochiai

    2013-01-01

    The recent applications of a TiO2-modified Ti-mesh filter (TMiP™) for water purification are summarized with newly collected data including biological assays as well as sewage water treatment. The water purification reactors consist of the combination of a TMiP, a UV lamp, an excimer VUV lamp, and an ozonation unit. The water purification abilities of the reactor were evaluated by decomposition of organic contaminants, inactivation of waterborne pathogens, and treatment efficiency for sewage ...

  1. HybridICE® filter: ice separation in freeze desalination of mine waste waters.

    Science.gov (United States)

    Adeniyi, A; Maree, J P; Mbaya, R K K; Popoola, A P I; Mtombeni, T; Zvinowanda, C M

    2014-01-01

    Freeze desalination is an alternative method for the treatment of mine waste waters. HybridICE(®) technology is a freeze desalination process which generates ice slurry in surface scraper heat exchangers that use R404a as the primary refrigerant. Ice separation from the slurry takes place in the HybridICE filter, a cylindrical unit with a centrally mounted filter element. Principally, the filter module achieves separation of the ice through buoyancy force in a continuous process. The HybridICE filter is a new and economical means of separating ice from the slurry and requires no washing of ice with water. The performance of the filter at a flow-rate of 25 L/min was evaluated over time and with varied evaporating temperature of the refrigerant. Behaviours of the ice fraction and residence time were also investigated. The objective was to find ways to improve the performance of the filter. Results showed that filter performance can be improved by controlling the refrigerant evaporating temperature and eliminating overflow.

  2. Investigation of the performance of non-conventional pressure filter system in potable water treatment.

    Science.gov (United States)

    Kelkar, P S; Andey, S P; Dhage, S S

    2005-07-01

    The biflow pressure filter system installed at a residential campus was investigated for its performance under different operating conditions. The investigation was carried out to evaluate raw water quality, chemical dosing systems, filter media and overall filtration performance. Treatability studies were carried out to decide optimum doses of chemicals sused in potable water treatment system. It was found that the biflow pressure system could not deliver filtrate of desired quality and therefore its use in potable water treatment may cause ill effects in human-beings.

  3. Comammox Nitrospira are key nitrifiers in diverse groundwater-fed drinking water filters

    DEFF Research Database (Denmark)

    Fowler, Jane; Palomo, Alejandro; Smets, Barth F.

    Nitrification is a dominant process in groundwater-fed rapid sand filters (RSFs) used for drinking water purification. Near complete removal of ammonium and nitrite is required in the EU and Denmark due to strict regulatory limits that enable high water stability in the distribution system. RSFs....... Temperature as well as the sulfate and calcium content of the influent water made significant contributions towards explaining both the total and comammox community structures, while the iron content of the filter material made a significant contribution to explaining only the structure of the comammox...

  4. Experimental investigation of an optical water filter for Photovoltaic/Thermal conversion module

    International Nuclear Information System (INIS)

    Al-Shohani, Wisam A.M.; Sabouri, Aydin; Al-Dadah, Raya; Mahmoud, Saad; Butt, Haider

    2016-01-01

    Highlights: • New design of Photovoltaic/Thermal system is proposed. • Using the optical water layer as a spectrum splitter is tested experimentally. • Optical rig is developed to study the optical performance of water layer. • Energy conversion under different water layer thicknesses is determined. - Abstract: This paper presents an experimental investigation of a novel optical water filter used for Photovoltaic/Thermal and Concentrating Photovoltaic/Thermal modules. A water layer is used as a spectrum splitter of solar radiation placed above the photovoltaic cells and as a thermal working fluid simultaneously. The water layer absorbs the ultraviolet and part of infrared, which are not used by the photovoltaic, but transmits the visible and some of infrared to the solar cell surface which are used by the photovoltaic. In this work, the transmittance of the optical water filter was measured for different water thicknesses (1, 2, 3, 4, and 5 cm) and radiation wavelength ranging from 0.35 to 1 μm. Results show that there is a significant effect of the water layer thickness on the transmittance of the spectra where the transmittance decreases as the water layer increases. Moreover, energy conversion rate of photovoltaic with the optical water filter at different water layer thicknesses has been determined.

  5. Submerged Pond Sand Filter-A Novel Approach to Rural Water Supply

    DEFF Research Database (Denmark)

    Øhlenschlæger, Mia; Christensen, Sarah Christine Boesgaard; Bregnhøj, Henrik

    2016-01-01

    with a level of faecal coliforms of 2 +/- 2 colony forming units (CFU)/100 mL measured in the treated water. Turbidity was visibly removed during treatment. When water was retrieved from the filter through a manual pump for long consistent time intervals (60 min), faecal coliform counts increased from four...

  6. Activated soil filters for removal of biocides from contaminated run-off and waste-waters

    DEFF Research Database (Denmark)

    Bester, Kai; Banzhaf, Stefan; Burkhardt, Michael

    2011-01-01

    Building facades can be equipped with biocides to prevent formation of algal, fungal and bacterial films. Thus run-off waters may contain these highly active compounds. In this study, the removal of several groups of biocides from contaminated waters by means of an activated soil filter was studied...

  7. Method for the analysis of asbestos fibers in water using MCE filters

    Energy Technology Data Exchange (ETDEWEB)

    Brackett, K.A.; Clark, P.J.; Millette, J.R.

    1993-01-01

    A method using mixed cellulose ester filters for the preparation of water samples to be tested under the Federal guidelines for asbestos in drinking water is described. Updating of the previous counting rules has been done to bring them closer to those specified in the AHERA protocol.

  8. Filter-feeding bivalves can remove avian influenza viruses from water and reduce infectivity

    Science.gov (United States)

    Avian influenza (AI) viruses are transmitted within wild aquatic bird populations through an indirect fecal-oral route involving fecal-contaminated water. In this study, the influence of filter-feeding bivalves, Corbicula fluminea, on the infectivity of AI virus in water was examined. A single cla...

  9. Batch test screening of industrial product/byproduct filter materials for agricultural drainage water treatment

    Science.gov (United States)

    Filter treatment may be a viable means for removing the nitrate, phosphate, and pesticides discharged with agricultural drainage waters that cause adverse environmental impacts within the U.S. on local, regional, and national scales. Laboratory batch test screening for agricultural drainage water ...

  10. Highly selective dummy molecularly imprinted polymer as a solid-phase extraction sorbent for five bisphenols in tap and river water.

    Science.gov (United States)

    Sun, Xiaoli; Wang, Jincheng; Li, Yun; Jin, Jing; Zhang, Baoqin; Shah, Syed Mazhar; Wang, Xueli; Chen, Jiping

    2014-05-23

    A simple and fast method for both dummy template selection and polymer composition optimization is proposed here. A series of dummy templates for bisphenols imprinting were screened by running them on a non-imprinted polymer (NIP) column with porogen solvent as mobile phase. The tested dummy templates mainly involved bisphenol S (BPS), bromobisphenol A (TBBPA), bisphenol F (BPF), bisphenol E (BPE), bisphenol B (BPB), bisphenol AF (BPAF), 2,2',6,6'-tetramethyl-4,4'-sulfonyldiphenol (BS-TM) and 4,4'-diaminodiphenylmethane (DADPM). Different monomers and porogens were also investigated for BPS and DADPM using the same method. BPS dummy template was finally selected with acetonitrile and 4-VP as porogen and monomer. The resulting dummy molecularly imprinted polymer (DMIP) achieved superior affinities for BPF, BPE, BPA, BPB and BPAF with imprinting factors 14.5, 13.8, 8.7, 5.7 and 4.2, respectively. An efficient method based on BPS-DMIP-SPE coupled with HPLC-UV was developed for selective extraction of BPF, BPE, BPA, BPB and BPAF in water samples. The method showed excellent recoveries (89.4-102.0%) and precision (RSD 0.3-4.8%, n=5) for tap and river water samples spiked at three concentration levels each (40, 200 and 1000ngL(-1)). The detection limits ranged between 2.2 and 3.8ngL(-1) with a sample volume of 500mL. The result demonstrated the superiority of the optimized method for selective extraction of BPs in water samples at the ngL(-1) level. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Voltammetric detection of trifluralin in tap water, fruit juice, and vegetable extracts in the presence of surfactants.

    Science.gov (United States)

    Ferro, Érica Castro; Cardoso, Claudia A L; Arruda, Gilberto J

    2017-10-03

    This study describes a novel electrochemical method to determine the herbicide trifluralin in samples of water, fruit juice, and vegetable extracts in the presence of surfactants, using a glassy carbon electrode (GCE). In acidic media, trifluralin was irreversible on the glassy carbon electrode surface at -0.5 V vs. Ag/AgCl. Surfactant presence on the electrode-solution interface modified current intensities and shifted the reduction peak potential of trifluralin. Different types of surfactant and their concentrations were investigated. The anionic surfactant significantly enhanced the peak current intensity of trifluralin. Under optimal analytical conditions, an analytical curve was obtained in the concentration range of 0.48-32.20 µM. The limits of detection and quantification were estimated at 0.031 and 0.104 µM, respectively. The method was successfully applied to quantify trifluralin in samples of water, orange and tomato juice, and green pepper, carrot, and onion extracts, with recovery rates of 97.9-102.1%. The results were in good agreement with those obtained using high-performance liquid chromatography, indicating that the proposed electrochemical method can be employed to quantify trifluralin in various types foods, with sensitivity, specificity, selectivity and reproducibility.

  12. Initial testing of electrospun nanofibre filters in water filtration ...

    African Journals Online (AJOL)

    2009-11-17

    Nov 17, 2009 ... techniques for the production of flat-sheet membranes and the application of these membranes in water filtration. ... be used for water filtration applications, but that further improvements are necessary before these membranes can be practically .... nanofibres so that the pore size increases and bacteria leak.

  13. Radium 226 in filter sludges from ground water treatment

    International Nuclear Information System (INIS)

    Haberer, K.

    1999-01-01

    Sludge waters from 80 different water works in Germany have been investigated on the content of radium 226, which appears wide-spread in ground water in very low concentrations, but heavily enriched in treatment sludges. The radium 226 contents of the sludge waters from treatment facilities for iron and manganese removal and in some cases for softening and flocculation were related to the dry residues separately determined. The specific Ra 226-activities of the dry residues fit to a log-norm distribution with a median value of 500 Bq/kg and a deviation of 1.7. 90% of the values were below 1200 Bq/kg. Radium 226 is strongly fixed to the sludges and will not be washed out, as elution experiments showed. Further investigations and calculations of the radium 226 content in the treated ground water proved the plausibility of the results. (orig.) [de

  14. From source to filter: changes in bacterial community composition during potable water treatment.

    Science.gov (United States)

    Zanacic, Enisa; McMartin, Dena W; Stavrinides, John

    2017-06-01

    Rural communities rely on surface water reservoirs for potable water. Effective removal of chemical contaminants and bacterial pathogens from these reservoirs requires an understanding of the bacterial community diversity that is present. In this study, we carried out a 16S rRNA-based profiling approach to describe the bacterial consortia in the raw surface water entering the water treatment plants of 2 rural communities. Our results show that source water is dominated by the Proteobacteria, Bacteroidetes, and Cyanobacteria, with some evidence of seasonal effects altering the predominant groups at each location. A subsequent community analysis of transects of a biological carbon filter in the water treatment plant revealed a significant increase in the proportion of Proteobacteria, Acidobacteria, Planctomycetes, and Nitrospirae relative to raw water. Also, very few enteric coliforms were identified in either the source water or within the filter, although Mycobacterium was of high abundance and was found throughout the filter along with Aeromonas, Legionella, and Pseudomonas. This study provides valuable insight into bacterial community composition within drinking water treatment facilities, and the importance of implementing appropriate disinfection practices to ensure safe potable water for rural communities.

  15. Batch Test Screening of Industrial Product/Byproduct Filter Materials for Agricultural Drainage Water Treatment

    Directory of Open Access Journals (Sweden)

    Barry J. Allred

    2017-10-01

    Full Text Available Filter treatment may be a viable means for removing the nitrate (NO3−, phosphate (PO43−, and pesticides discharged with agricultural drainage waters that cause adverse environmental impacts within the U.S. on local, regional, and national scales. Laboratory batch test screening for agricultural drainage water treatment potential was conducted on 58 industrial product/byproduct filter materials grouped into six categories: (1 high carbon content media; (2 high iron content media; (3 high aluminum content media; (4 surfactant modified clay/zeolite; (5 coal combustion residuals; and (6 spent foundry sands. Based on a percent contaminant removal criteria of 75% or greater, seven industrial products/byproducts were found to meet this standard for NO3− alone, 44 met this standard for PO43−, and 25 met this standard for the chlorinated triazine herbicide, atrazine. Using a 50% or greater contaminant removal criteria, five of the industrial product/byproduct filter materials exhibited potential for removing NO3−, PO43−, and atrazine together; eight showed capability for combined NO3− and PO43− removal; 21 showed capability for combined PO43− and atrazine removal; and nine showed capability for combined NO3− and atrazine removal. The results of this study delineated some potential industrial product/byproduct filter materials for drainage water treatment; however, a complete feasibility evaluation for drainage water treatment of any of these filter materials will require much more extensive testing.

  16. Designing metallic iron based water filters: Light from methylene blue discoloration.

    Science.gov (United States)

    Btatkeu-K, B D; Tchatchueng, J B; Noubactep, C; Caré, S

    2016-01-15

    Available water filtration systems containing metallic iron (Fe(0) filters) are pragmatically designed. There is a lack of sound design criteria to exploit the full potential of Fe(0) filters. A science-based design relies on valuable information on processes within a Fe(0) filter, including chemical reactions, hydrodynamics and their relation to the performance of the filter. The aim of this study was to establish a simple method to evaluate the initial performance of Fe(0) filters. The differential adsorptive affinity of methylene blue (MB) onto sand and iron oxide is exploited to characterize the evolution of a Fe(0)/sand system using the pure sand system as operational reference. Five systems were investigated for more than 70 days: pure sand, pure Fe(0), Fe(0)/sand, Fe(0)/pumice and Fe(0)/sand/pumice. Individual systems were characterized by the extent of changes in pH value, iron breakthrough, MB breakthrough and hydraulic conductivity. Results showed that for MB discoloration (i) pure sand was the most efficient system, (ii) hybrid systems were more sustainable than the pure Fe(0) system, and (iii) the pores of used pumice are poorly interconnected. Characterizing the initial reactivity of Fe(0) filters using MB discoloration has introduced a powerful tool for the exploration of various aspects of filter design. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Bowtie filter and water calibration in the improvement of cone beam CT image quality

    International Nuclear Information System (INIS)

    Li Minghui; Dai Jianrong; Zhang Ke

    2010-01-01

    Objective: To evaluate the improvement of cone beam CT (CBCT) image quality by using bewtie filter (F 1 ) and water calibration. Methods: First the multi-level gain calibration of the detector panel with the method of Cal 2 calibration was performed, and the CT images of CATPHAN503 with F 0 and bowtie filter were collected, respectively. Then the detector panel using water calibration kit was calibrated, and images were acquired again. Finally, the change of image quality after using F 1 and (or) water calibration method was observed. The observed indexes included low contrast visibility, spatial uniformity, ring artifact, spatial resolution and geometric accuracy. Results: Comparing with the traditional combination of F 0 filter and Cal 2 calibration, the combination of bowtie filter F 1 and water calibration improves low contrast visibility by 13.71%, and spatial uniformity by 54. 42%. Water calibration removes ring artifacts effectively. However, none of them improves spatial resolution and geometric accuracy. Conclusions: The combination of F 1 and water calibration improves CBCT image quality effectively. This improvement is aid to the registration of CBCT images and localization images. (authors)

  18. Depth investigation of rapid sand filters for drinking water production reveals strong stratification in nitrification biokinetic behavior

    DEFF Research Database (Denmark)

    Tatari, Karolina; Smets, Barth F.; Albrechtsen, Hans-Jørgen

    2016-01-01

    The biokinetic behavior of NH4 + removal was investigated at different depths of a rapid sand filter treating groundwater for drinking water preparation. Filter materials from the top, middle and bottom layers of a full-scale filter were exposed to various controlled NH4 + loadings in a continuous...

  19. Assessment of Filter Materials for Removal of Contaminants From Agricultural Drainage Waters

    Science.gov (United States)

    Allred, B. J.

    2007-12-01

    Fertilizer nutrients and pesticides applied on farm fields, especially in the Midwest U.S., are commonly intercepted by buried agricultural drainage pipes and then discharged into local streams and lakes, oftentimes resulting in an adverse environmental impact on these surface water bodies. Low cost filter materials have the potential to remove nutrient and pesticide contaminants from agricultural drainage waters before these waters are released from the farm site. Batch tests were conducted to find filter materials potentially capable of removing nutrient (nitrate and phosphate) and pesticide (atrazine) contaminants from subsurface drainage waters. For each batch test, stock solution (40 g) and filter material (5 g) were combined in 50 mL Teflon centrifuge tubes and mixed with a rotator for 24 hours. The stock solution contained 50 mg/L nitrate-N, 0.25 mg/L phosphate-P, 0.4 mg/L atrazine, 570 mg/L calcium sulfate, and 140 mg/L potassium chloride. Calcium sulfate and potassium chloride were added so that the stock solution would contain anions and cations normally found in agricultural drainage waters. There were six replicate batch tests for each filter material. At the completion of each test, solution was removed from the centrifuge tube and analyzed for nitrate-N, phosphate-P, and atrazine. A total of 38 filter materials were tested, which were divided into five classes; high carbon content substances, high iron content substances, high aluminum content substances, surfactant modified clay/zeolite, and coal combustion products. Batch test results generally indicate, that with regard to the five classes of filter materials; high carbon content substances adsorbed atrazine very effectively; high iron content substances worked especially well removing almost all of the phosphate present; high aluminum content substances lowered phosphate levels; surfactant modified clay/zeolite substantially reduced both nitrate and atrazine; and coal combustion products

  20. Microbial degradation of pesticides in rapid sand filters for treatment of drinking water

    DEFF Research Database (Denmark)

    Hedegaard, Mathilde Jørgensen; Albrechtsen, Hans-Jørgen

    2014-01-01

    – up to 43% of the initial glyphosate was found as CO2 after 6 days. At Sjælsø waterworks Plant II the contact time in the primary rapid sand filter was 43 minutes. It was found that less than 20 minutes was needed to biologically remove more than 50% of the initial bentazone (concentration 0.1 μg......In Denmark drinking water supply is based on groundwater which is treated by aeration followed by filtration in rapid sand filters. Unfortunately pesticide contamination of the groundwater poses a threat to the water supply, since the simple treatment process at the waterworks is not considered...

  1. Pressurized water reactor monitoring. Study of detection, diagnostic and estimation (least squares and filtering) methods

    International Nuclear Information System (INIS)

    Gillet, M.

    1986-07-01

    This thesis presents a study for the surveillance of the Primary circuit water inventory of a pressurized water reactor. A reference model is developed for the development of an automatic system ensuring detection and real-time diagnostic. The methods to our application are statistical tests and adapted a pattern recognition method. The estimation of the detected anomalies is treated by the least square fit method, and by filtering. A new projected optimization method with superlinear convergence is developed in this framework, and a segmented linearization of the model is introduced, in view of a multiple filtering. 46 refs [fr

  2. Serological responses to Cryptosporidium antigens in inhabitants of Hungary using conventionally filtered surface water and riverbank filtered drinking water.

    Science.gov (United States)

    Farkas, K; Plutzer, J; Moltchanova, E; Török, A; Varró, M J; Domokos, K; Frost, F; Hunter, P R

    2015-10-01

    In this study the putative protective seroprevalence (PPS) of IgG antibodies to the 27-kDa and 15/17-kDa Cryptosporidium antigens in sera of healthy participants who were and were not exposed to Cryptosporidium oocysts via surface water-derived drinking water was compared. The participants completed a questionnaire regarding risk factors that have been shown to be associated with infection. The PPS was significantly greater (49-61%) in settlements where the drinking water originated from surface water, than in the control city where riverbank filtration was used (21% and 23%). Logistic regression analysis on the risk factors showed an association between bathing/swimming in outdoor pools and antibody responses to the 15/17-kDa antigen complex. Hence the elevated responses were most likely due to the use of contaminated water. Results indicate that waterborne Cryptosporidium infections occur more frequently than reported but may derive from multiple sources.

  3. Water Quality of Trickling Biological Periwinkle Shells Filter for ...

    African Journals Online (AJOL)

    The designed biofilter and other system components were constructed, assembled and commissioned for pilot catfish production. The system with the designed biofilter served as the treatment system, while that without biofilter served as the control system. Data were collected daily (except for BOD5) on water quality ...

  4. Biological drinking water treatment of anaerobic groundwater in trickling filters

    NARCIS (Netherlands)

    De Vet, W.W.J.M.

    2011-01-01

    Drinking water production from anaerobic groundwater is usually achieved by so called conventional techniques such as aeration and sand filtration. The notion conventional implies a long history and general acceptation of the application, but doesn’t necessarily mean a thorough understanding of the

  5. Initial testing of electrospun nanofibre filters in water filtration ...

    African Journals Online (AJOL)

    The aim of this study was to evaluate the use of nanofibre microfiltration membranes, spun by an innovative electrospinning technique, in water filtration applications. As such, this study bridges the gap between developments in electrospinning techniques for the production of flat-sheet membranes and the application of ...

  6. Origin of bank filtered groundwater resources covering the drinking water demand of Budapest, Hungary

    International Nuclear Information System (INIS)

    Forizs, I.; Deak, J.

    1998-01-01

    The ratio of Danube water/infiltrated precipitation has been determined using stable oxygen isotope data on four parts of the protection area of the bank filtered water works supplying drinking water for Budapest, Hungary. These ratios comparing to those calculated by hydraulic modeling rarely match each other. The Danube water transit time calculated fro few wells by isotopic data are usually shorter than those determined by hydraulic modeling. The relation between the δ 18 O values and the nitrate chloride and sulfate pollutants shows that the source of the pollutants is on the island area (sewage water, agricultural activity and salt used for de-icing asphalt roads). (author)

  7. The Challenge of Producing and Marketing Colloidal Silver Water Filters in Nepal

    Directory of Open Access Journals (Sweden)

    Anne Bogler

    2015-07-01

    Full Text Available Background: Obtaining safe drinking water can be a challenge in Nepal. By training potters and setting up production sites for Colloidal Silver Filters, several non-governmental organizations have tried to provide local people with a low-cost option for household water treatment. Out of 19 trained entrepreneurs, only four are currently producing filters. The goal of this evaluation was to find out what conditions lead to the successful continuation of the production and the reasons for failure. Methods: The evaluation of the potters was based on a Qualitative Comparative Analysis and the conditions looked at were: “Production”, “Collaboration”, “Market” and “Potter”. Results: Analysis showed that production problems and insufficient demand led to the termination of ceramic filter production and that both trouble-free production and high demand are necessary for a sustainable business.

  8. Biodegradation of gasoline compounds (BTEX) in a water works sand filter

    DEFF Research Database (Denmark)

    Arvin, Erik; Engelsen, P.; Sebber, U.

    2004-01-01

    Various chemical compounds including aromatic gasoline compounds frequently contaminate drinking water wells in urban areas. Because ground water treatment is simple, usually consisting of aeration/stripping and sand-filtration, it is of significant interest to know the ability of the conventional...... treatment to remove the chemical contaminants. The removal of gasoline compounds was investigated in a two-stage pilot scale sand filter, each with a filter depth of 0.8-1 m and with a filtration rate of 7.6 m/h. The concentrations of aromatic compounds were in the range 7-15 mu g/L, which are realistically...... sand grains). Influent iron concentrations in the range 0-4 mg/L and backwashing did not adversely affect the biodegradation of hydrocarbons. This study has shown that a conventional biological active sand filter can act as an efficient barrier against gasoline compounds, thereby saving the consumer...

  9. Treatment of Palmar Hyperhidrosis with Tap Water Iontophoresis: A Randomized, Sham-Controlled, Single-Blind, and Parallel-Designed Clinical Trial.

    Science.gov (United States)

    Kim, Do Hun; Kim, Tae Han; Lee, Seung Ho; Lee, Ai Young

    2017-12-01

    Palmar hyperhidrosis is a common disorder of excessive sweating. A number of studies have demonstrated the effectiveness of iontophoresis in the treatment of palmar hyperhidrosis. However, controlled clinical studies on iontophoresis for palmar hyperhidrosis have been limited. To determine the efficacy and safety of iontophoresis in the treatment of palmar hyperhidrosis with a randomized, sham-controlled, single-blind, and parallel-designed study. Twenty nine patients with significant palmar hyperhidrosis were enrolled in this study. They received active iontophoresis treatment (group A) or sham treatment (group B). Iontophoresis was performed 20 minutes each time, five times per week, for 2 weeks. Its efficacy was assessed with starch-iodine test, mean sweat secretion rate, and hyperhidrosis disease severity scale. Twenty-seven of the 29 patients completed the 2-week treatment. After completion of 10 times of treatment, results of the starch-iodine test showed clinical improvement in 92.9% of patients in group A and 38.5% of patients in group B ( p =0.001). The mean sweat secretion rate was reduced by 91.8% of patients in group A and by 39.1% of patients in group B ( p <0.001). Improvement in quality of life was reported by 78.6% of patients in group A and by 30.8% of patients in group B ( p =0.028). In group A, one case of localized adverse event was noted, although no adverse event was encountered in group B. Tap water iontophoresis could be used as an effective and safe treatment modality for palmar hyperhidrosis.

  10. Dataset on the cost estimation for spent filter backwash water (SFBW treatment

    Directory of Open Access Journals (Sweden)

    Afshin Ebrahimi

    2017-12-01

    Full Text Available The dataset presented in this article are related to the research article entitled “Hybrid coagulation-UF processes for spent filter backwash water treatment: a comparison studies for PAFCl and FeCl3 as a pre-treatment” (Ebrahimi et al., 2017 [1]. This article reports the cost estimation for treating produced spent filter backwash water (SFBW during water treatment in Isfahan- Iran by various methods including primary sedimentation, coagulation & flocculation, second clarification, ultra filtration (UF and recirculation of settled SFBW to water treatment plant (WTP entrance. Coagulation conducted by PAFCl and FeCl3 as pre polymerized and traditional coagulants. Cost estimation showed that contrary to expectations, the recirculation of settled SFBW to WTP entrance is more expensive than other method and it costs about $ 37,814,817.6. Versus the cheapest option related to separate primary sedimentation, coagulation & flocculation in WTP. This option cost about $ 4,757,200 and $ 950,213 when FeCl3 and PAFCl used as coagulant, respectively. Keywords: Spent filter backwash water, Water treatment, Coat estimation, Water reuse

  11. The effect of algal and bacterial filters on sea water quality during ...

    African Journals Online (AJOL)

    The increase in Cu concentra- tion was thought to be due to condensation moisture in the copper piping used in the air reticulation system of the laboratory building. To remove this moisture, a. 'Compair' Model M4 automatic water-ejector and filter was installed into the airline system for the second experi- mental trial.

  12. Anaerobic incubation of membrane filter cultures for improved detection of fecal coliforms from recreational waters.

    OpenAIRE

    Doyle, J D; Tunnicliff, B; Brickler, S K; Kramer, R E; Sinclair, N A

    1984-01-01

    Anaerobic incubation of membrane filter cultures significantly enhanced detection of fecal coliforms in surface-water samples from recreational beaches. In contrast to standard aerobic incubation, anaerobic incubation suppressed overgrowth of masking, noncoliform bacteria but did not increase the frequency of fecal coliform recovery.

  13. Low-cost domestic water filter: The case for a process-based ...

    African Journals Online (AJOL)

    Low-cost domestic water filter: The case for a process-based approach for the development of a rural technology product. ... Since the project aims at technology transfer to the rural poor for generating rural livelihoods, appropriate financial models and the general sustainability issues for such an activity are briefly discussed ...

  14. Water softening by single-bowl ion exchange filter efficiency estimate and improvement

    OpenAIRE

    Kostygin, V. A.; Stolyarenko, G. S.; Kochetov, G. M.; Tugay, A. M.; Vashchenko, V. N.

    2014-01-01

    The article presents results of experimental investigations of the water softener in a laboratory installation of uninterruptible countercurrent ion exchange filter, which has a movable layer of ion exchange material. The installation provides for two simultaneous processes: counter ion sorption and regeneration of the sorbent with the processing capability of the sorbent in the regeneration zone by ultrasonic radiation.

  15. Effects of dynamic operating conditions on nitrification in biological rapid sand filters for drinking water treatment

    DEFF Research Database (Denmark)

    Lee, Carson Odell; Boe-Hansen, Rasmus; Musovic, Sanin

    2014-01-01

    Biological rapid sand filters are often used to remove ammonium from groundwater for drinking water supply. They often operate under dynamic substrate and hydraulic loading conditions, which can lead to increased levels of ammonium and nitrite in the effluent. To determine the maximum nitrification...

  16. Noninvasive mapping of water diffusional exchange in the human brain using filter-exchange imaging.

    Science.gov (United States)

    Nilsson, Markus; Lätt, Jimmy; van Westen, Danielle; Brockstedt, Sara; Lasič, Samo; Ståhlberg, Freddy; Topgaard, Daniel

    2013-06-01

    We present the first in vivo application of the filter-exchange imaging protocol for diffusion MRI. The protocol allows noninvasive mapping of the rate of water exchange between microenvironments with different self-diffusivities, such as the intracellular and extracellular spaces in tissue. Since diffusional water exchange across the cell membrane is a fundamental process in human physiology and pathophysiology, clinically feasible and noninvasive imaging of the water exchange rate would offer new means to diagnose disease and monitor treatment response in conditions such as cancer and edema. The in vivo use of filter-exchange imaging was demonstrated by studying the brain of five healthy volunteers and one intracranial tumor (meningioma). Apparent exchange rates in white matter range from 0.8±0.08 s(-1) in the internal capsule, to 1.6±0.11 s(-1) for frontal white matter, indicating that low values are associated with high myelination. Solid tumor displayed values of up to 2.9±0.8 s(-1). In white matter, the apparent exchange rate values suggest intra-axonal exchange times in the order of seconds, confirming the slow exchange assumption in the analysis of diffusion MRI data. We propose that filter-exchange imaging could be used clinically to map the water exchange rate in pathologies. Filter-exchange imaging may also be valuable for evaluating novel therapies targeting the function of aquaporins. Copyright © 2012 Wiley Periodicals, Inc.

  17. [Hygienic study of an activated fibrous charcoal material as a sorbing filtering element for drinking water afterpurification].

    Science.gov (United States)

    Prokopov, V A; Mironets, N V; Gakal, R K; Maktaz, E D; Dugan, A M; Teteneva, I A; Tarabarova, S B; Martyshchenko, N V; Nadvornaia, Zh D

    1993-01-01

    The results of complex toxicological and hygienic study showed that the quality of pipe water filtered through the activated carbonic fibrous material (ACFM) "Dnepr-F" forming a part of absorptive filtering element improved markedly. The content of organic substances decreased drastically as well as that of nitrates and iron. Microbiological indices did not suffer appreciable changes and were within permissible limits. The water filtered through the absorptive element with ACFM had no adverse influence on the organisms of warm-blooded animals. Proceeding from foregoing one can conclude that the "Dnepr-F" may be recommended as a part of absorptive filtering element for the final refinement of drinking water.

  18. Results of heavy metals and other water quality levels in tap water from Çan sourced from Ağı Dağı (Mt. Ağı) (Çanakkale, Turkey).

    Science.gov (United States)

    Kilinc, Gamze; Yilmaz, Selehattin; Turkoglu, Muhammet; Erdugan, Huseyin

    2016-06-01

    In this study, the concentrations of heavy metals Pb, Cu, Zn, Cd, Ni, Fe, Mn and Cr were determined using an inductively coupled plasma and optical emission spectrophotometer (ICP-OES), and water quality parameters pH, temperature, and conductivity were measured using the YSI 556 MPS water probe. The water samples were collected monthly from five different street tap water points sourced from Mt. Agi (Ağı Dağı in Turkish) spring waters between May 2012 and February 2013 in Çan (Canakkale, Turkey). All results were compared with the drinking water standards of the Turkish Standards Institute (TSE 266), World Health Organization, European Union and US Environmental Protection Agency. While concentrations of Cu, Zn, Fe, and Mn were within limit values, Pb, Cd, Ni, and Cr were at undetectable limits. The highest concentrations of Cu, Zn, Fe, and Mn were 0.010 ppm, 0.018 ppm, 0.058 ppm, and 0.014 ppm, respectively. The findings revealed that although there was no public health risk in view of heavy metal concentrations, there was an acidity problem due to lower pH levels correlated with some heavy metals such as Cu (R = 0.419), Fe (R = -0.421) and Mn (R = -0.687).

  19. Assessment of addition of biochar to filtering mixtures for potential water pollutant removal

    OpenAIRE

    Piscitelli, Lea; Rivier, Pierre-Adrien; Mondelli, Donato; Miano, Teodoro; Joner, Erik J.

    2017-01-01

    Green roofs are used increasingly to alleviate peaks of water discharge into the sewage systems in urban areas. Surface runoff from roofs contain pollutants from dry and wet deposition, and green roofs offer a possibility to reduce the amounts of pollutants in the water discharged from roofs by degradation and filtering. These pollutants would otherwise enter wastewater treatments plants and ultimately end up in sewage sludge that is spread on agricultural soils. The most common substrates us...

  20. Clear of underground water from ferric and manganese modified filtering material active pink sand

    Science.gov (United States)

    Skolubovich, Yury; Voytov, Evgeny; Skolubovich, Alexey; Ilyina, Lilia

    2017-10-01

    The article analyzes the methods of purification of groundwater from iron and manganese. A particular problem is the removal of the manganese compounds from water. For the water treatment plants of small and medium capacity economically viable use of the modified filter materials. This research paper presents the technological characteristics of different catalytically active materials. The article describes the results of a study of a new modified material Active pink sand to clean groundwater from iron, manganese and other impurities.

  1. Dataset on the spent filter backwash water treatment by sedimentation, coagulation and ultra filtration.

    Science.gov (United States)

    Mahdavi, Mokhtar; Ebrahimi, Afshin; Azarpira, Hossein; Tashauoei, Hamid Reza; Mahvi, Amir Hossein

    2017-12-01

    During operation of most water treatment plants, spent filter backwash water (SFBW) is generated, which accounts about 2-10% of the total plant production. By increasing world population and water shortage in many countries, SFBW can be used as a permanent water source until the water treatment plant is working. This data article reports the practical method being used for water reuse from SFBW through different method including pre-sedimentation, coagulation and flocculation, second clarification, ultra filtration (UF) and returned settled SFBW to the beginning of water treatment plant (WTP). Also, two coagulants of polyaluminum ferric chloride (PAFCl) and ferric chloride (FeCl 3 ) were investigated with respect to their performance on treated SFBW quality. Samples were collected from Isfahan's WTP in Iran during spring and summer season. The acquired data indicated that drinkable water can be produced form SFBW by applying hybrid coagulation-UF process (especially when PAFCl used as coagulant).

  2. Microbiological evaluation of water during the 2011 flood crisis in Thailand

    International Nuclear Information System (INIS)

    Chaturongkasumrit, Yuphakhun; Techaruvichit, Punnida; Takahashi, Hajime; Kimura, Bon; Keeratipibul, Suwimon

    2013-01-01

    In 2011, a severe flood occurred in Thailand, covering nearly half the country in water for several months. The contamination of floodwater and subsequent contamination of water for human consumption could have potentially led to a widespread health crisis. However, to date, no study has been conducted to determine the safety of the waters used for human consumption in Thailand during the severe flood. Therefore, we conducted microbiological analysis of 4 kinds of water (floodwater, river water, tap water, and filtered tap water) collected from industrial and residential areas that were damaged due to flooding. Higher net levels of bacteria were found in water with a higher turbidity. No clear trend was observed in the pH value of all 4 water samples. The level of total bacterial contamination in the water samples was estimated by real-time quantitative polymerase chain reaction (PCR). Eleven of the 12 tap water samples and all of the filtered tap water samples had a total bacterial load that exceeded the Thai water quality standards. One of the tap water samples and one of the filtered tap water samples were found to be positive for Shigella sp., although none of the floodwater samples showed detectable levels of this pathogen as determined by PCR analysis. One of the samples of floodwater was also found to be positive for Leptospira sp., but none of the tap water or filtered tap water samples were positive. Most of the tap water samples and all filtered tap water samples were found to be contaminated with Vibrio cholerae. Bacterial contamination in water samples was also analyzed by denaturing gradient gel electrophoresis (DGGE) analysis. These results revealed that several microorganisms were transferred via floodwater to different areas in the central part of Thailand and cross-contaminated between floodwater and water for human consumption. - Highlights: • We investigated the flood impact on the waters used for human consumption. • Higher net levels of

  3. Microbiological evaluation of water during the 2011 flood crisis in Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Chaturongkasumrit, Yuphakhun; Techaruvichit, Punnida; Takahashi, Hajime; Kimura, Bon [Department of Food Science and Technology, Faculty of Marine Science, Tokyo University of Marine Science and Technology, Tokyo 108-8477 (Japan); Keeratipibul, Suwimon, E-mail: Suwimon.k@chula.ac.th [Department of Food Technology, Faculty of Science, Chulalongkorn University, Phayathai Road, Bangkok 10330 (Thailand)

    2013-10-01

    In 2011, a severe flood occurred in Thailand, covering nearly half the country in water for several months. The contamination of floodwater and subsequent contamination of water for human consumption could have potentially led to a widespread health crisis. However, to date, no study has been conducted to determine the safety of the waters used for human consumption in Thailand during the severe flood. Therefore, we conducted microbiological analysis of 4 kinds of water (floodwater, river water, tap water, and filtered tap water) collected from industrial and residential areas that were damaged due to flooding. Higher net levels of bacteria were found in water with a higher turbidity. No clear trend was observed in the pH value of all 4 water samples. The level of total bacterial contamination in the water samples was estimated by real-time quantitative polymerase chain reaction (PCR). Eleven of the 12 tap water samples and all of the filtered tap water samples had a total bacterial load that exceeded the Thai water quality standards. One of the tap water samples and one of the filtered tap water samples were found to be positive for Shigella sp., although none of the floodwater samples showed detectable levels of this pathogen as determined by PCR analysis. One of the samples of floodwater was also found to be positive for Leptospira sp., but none of the tap water or filtered tap water samples were positive. Most of the tap water samples and all filtered tap water samples were found to be contaminated with Vibrio cholerae. Bacterial contamination in water samples was also analyzed by denaturing gradient gel electrophoresis (DGGE) analysis. These results revealed that several microorganisms were transferred via floodwater to different areas in the central part of Thailand and cross-contaminated between floodwater and water for human consumption. - Highlights: • We investigated the flood impact on the waters used for human consumption. • Higher net levels of

  4. Nickel removal from nickel plating waste water using a biologically active moving-bed sand filter.

    Science.gov (United States)

    Pümpel, Thomas; Macaskie, Lynne E; Finlay, John A; Diels, Ludo; Tsezos, Marios

    2003-12-01

    Efficient removal of dissolved nickel was observed in a biologically active moving-bed 'MERESAFIN' sand filter treating rinsing water from an electroless nickel plating plant. Although nickel is fully soluble in this waste water, its passage through the sand filter promoted rapid removal of approximately 1 mg Ni/l. The speciation of Ni in the waste water was modelled; the most probable precipitates forming under the conditions in the filter were predicted using PHREEQC. Analyses of the Ni-containing biosludge using chemical, electron microscopical and X-ray spectroscopic techniques confirmed crystallisation of nickel phosphate as arupite (Ni3(PO4)2 x 8H2O), together with hydroxyapatite within the bacterial biofilm on the filter sand grains. Biosorption contributed less than 1% of the overall sequestered nickel. Metabolising bacteria are essential for the process; the definitive role of specific components of the mixed population is undefined but the increase in pH promoted by metabolic activity of some microbial components is likely to promote nickel desolubilisation by others.

  5. Factors affecting continued use of ceramic water purifiers distributed to tsunami-affected communities in Sri Lanka.

    Science.gov (United States)

    Casanova, Lisa M; Walters, Adam; Naghawatte, Ajith; Sobsey, Mark D

    2012-11-01

    There is little information about continued use of point-of-use technologies after disaster relief efforts. After the 2004 tsunami, the Red Cross distributed ceramic water filters in Sri Lanka. This study determined factors associated with filter disuse and evaluate the quality of household drinking water. A cross-sectional survey of water sources and treatment, filter use and household characteristics was administered by in-person oral interview, and household water quality was tested. Multivariable logistic regression was used to model probability of filter non-use. At the time of survey, 24% of households (107/452) did not use filters; the most common reason given was breakage (42%). The most common household water sources were taps and wells. Wells were used by 45% of filter users and 28% of non-users. Of households with taps, 75% had source water Escherichia coli in the lowest World Health Organisation risk category (water source; households with taps were more likely to stop use than households with wells. Tap water users also had higher-quality source water, suggesting that disuse is not necessarily negative and monitoring of water quality can aid decision-making about continued use. To promote continued use, disaster recovery filter distribution efforts must be joined with capacity building for long-term water monitoring, supply chains and local production. © 2012 Blackwell Publishing Ltd.

  6. Microbiological Characterization of the International Space Station Water Processor Assembly External Filter Assembly S/N 01

    Science.gov (United States)

    Weir, Natalee; Wilson, Mark; Yoets, Airan; Yoets, Airan; Molina, Thomas; Bruce, Rebekah; Sitler, Glenn; Carter, Layne

    2012-01-01

    The External Filter Assembly (EFA) S/N 01 is a mesh screen filter with a pore size of approximately 300 micron that was installed in the International Space Station (ISS) Water Processor Assembly (WPA) between the Waste Tank and the Mostly Liquid Separator (MLS) on February 11, 2010 to protect clearances in the MLS solenoid valve SV_1121_3. A removal & replacement of the EFA Filter was performed on March 22, 2011 in response to increasing pressure across the Waste Tank solenoid valve SV_1121_1 and the EFA Filter. The EFA Filter was returned on ULF6 and received in the Boeing Huntsville Laboratory on June 13, 2011. The filter was aseptically removed from the housing, and the residual water was collected for enumeration and identification of bacteria and fungi. Swab samples of the filter surface were also collected for microbiological enumeration and identification. Sample analyses were performed by Boeing Huntsville Laboratory and NASA Johnson Space Center Microbiology for comparison. Photographic documentation of the EFA filter was performed using a stereo microscope and environmental scanning electron microscope. This paper characterizes the amount and types of microorganisms on the filter surface and in the residual water from the filter housing following 1 year of utilization in the ISS WPA.

  7. Endocrine disruptors in water filters used in the Rio dos Sinos Basin region, Southern Brazil

    Directory of Open Access Journals (Sweden)

    CM Furtado

    Full Text Available The activated carbon filter is used in residences as another step in the treatment of drinking water, based on a physical-chemical process to absorb pollutants that are not removed in conventional treatment. Endocrine disruptors (EDCs are exogenous substances or mixtures of substances that acts on the endocrine system similarly to the endogenously produced hormones, triggering malfunctions and harmful changes to human and animal health. The objective of the present work was to study EDCs through semi-quantitative analysis of residential water filters collected in the region of Rio dos Sinos basin, focusing on two specific classes: hormones and phenols. The solid phase extraction principle was used for the extraction of compounds and gas chromatography coupled with mass spectrometry for the separation and characterization of EDCs. Four samples of residential filters collected from public water distribution and artesian wells, from the cities of Novo Hamburgo and São Leopoldo were analysed. Using the developed methodology, it was possible to detect and comparatively quantify selected EDCs in all studied samples, which indicates the presence of these contaminants in drinking water from different sources.

  8. Endocrine disruptors in water filters used in the Rio dos Sinos Basin region, Southern Brazil.

    Science.gov (United States)

    Furtado, C M; von Mühlen, C

    2015-05-01

    The activated carbon filter is used in residences as another step in the treatment of drinking water, based on a physical-chemical process to absorb pollutants that are not removed in conventional treatment. Endocrine disruptors (EDCs) are exogenous substances or mixtures of substances that acts on the endocrine system similarly to the endogenously produced hormones, triggering malfunctions and harmful changes to human and animal health. The objective of the present work was to study EDCs through semi-quantitative analysis of residential water filters collected in the region of Rio dos Sinos basin, focusing on two specific classes: hormones and phenols. The solid phase extraction principle was used for the extraction of compounds and gas chromatography coupled with mass spectrometry for the separation and characterization of EDCs. Four samples of residential filters collected from public water distribution and artesian wells, from the cities of Novo Hamburgo and São Leopoldo were analysed. Using the developed methodology, it was possible to detect and comparatively quantify selected EDCs in all studied samples, which indicates the presence of these contaminants in drinking water from different sources.

  9. An Improved Cambridge Filter Pad Extraction Methodology to Obtain More Accurate Water and “Tar” Values: In Situ Cambridge Filter Pad Extraction Methodology

    Directory of Open Access Journals (Sweden)

    Ghosh David

    2014-07-01

    Full Text Available Previous investigations by others and internal investigations at Philip Morris International (PMI have shown that the standard trapping and extraction procedure used for conventional cigarettes, defined in the International Standard ISO 4387 (Cigarettes -- Determination of total and nicotine-free dry particulate matter using a routine analytical smoking machine, is not suitable for high-water content aerosols. Errors occur because of water losses during the opening of the Cambridge filter pad holder to remove the filter pad as well as during the manual handling of the filter pad, and because the commercially available filter pad holder, which is constructed out of plastic, may adsorb water. This results in inaccurate values for the water content, and erroneous and overestimated values for Nicotine Free Dry Particulate Matter (NFDPM. A modified 44 mm Cambridge filter pad holder and extraction equipment which supports in situ extraction methodology has been developed and tested. The principle of the in situ extraction methodology is to avoid any of the above mentioned water losses by extracting the loaded filter pad while kept in the Cambridge filter pad holder which is hermetically sealed by two caps. This is achieved by flushing the extraction solvent numerous times through the hermetically sealed Cambridge filter pad holder by means of an in situ extractor. The in situ methodology showed a significantly more complete water recovery, resulting in more accurate NFDPM values for high-water content aerosols compared to the standard ISO methodology. The work presented in this publication demonstrates that the in situ extraction methodology applies to a wider range of smoking products and smoking regimens, whereas the standard ISO methodology only applies to a limited range of smoking products and smoking regimens, e.g., conventional cigarettes smoked under ISO smoking regimen. In cases where a comparison of yields between the PMI HTP and

  10. Biodegradation of gasoline compounds (BTEX) in a water works sand filter

    DEFF Research Database (Denmark)

    Arvin, Erik; Engelsen, P.; Sebber, U.

    2004-01-01

    Various chemical compounds including aromatic gasoline compounds frequently contaminate drinking water wells in urban areas. Because ground water treatment is simple, usually consisting of aeration/stripping and sand-filtration, it is of significant interest to know the ability of the conventional...... treatment to remove the chemical contaminants. The removal of gasoline compounds was investigated in a two-stage pilot scale sand filter, each with a filter depth of 0.8-1 m and with a filtration rate of 7.6 m/h. The concentrations of aromatic compounds were in the range 7-15 mu g/L, which are realistically...... capital costs and operational costs from installation of supplementary treatment....

  11. Endocrine disruptors in water filters used in the Rio dos Sinos Basin region, Southern Brazil

    OpenAIRE

    Furtado, CM; von Mühlen, C

    2015-01-01

    The activated carbon filter is used in residences as another step in the treatment of drinking water, based on a physical-chemical process to absorb pollutants that are not removed in conventional treatment. Endocrine disruptors (EDCs) are exogenous substances or mixtures of substances that acts on the endocrine system similarly to the endogenously produced hormones, triggering malfunctions and harmful changes to human and animal health. The objective of the present work was to study EDCs thr...

  12. Water

    Science.gov (United States)

    ... Marion County, Indiana Salt Lake County, Utah Seattle-King County, Washington Tools and Training CLPPP CAP Healthy ... wish to use tap water for drinking or cooking, especially when the water has been off and ...

  13. Drawer compacted sand filter: a new and innovative method for on-site grey water treatment.

    Science.gov (United States)

    Assayed, Almoayied; Chenoweth, Jonathan; Pedley, Steven

    2014-01-01

    In this paper, results ofa new sand filter design were presented. The drawer compacted sand filter (DCSF) is a modified design for a sand filter in which the sand layer is broken down into several layers, each of which is 10 cm high and placed in a movable drawer separated by a 10 cm space. A lab-scale DCSF was designed and operated for 330 days fed by synthetic grey water. The response of drawer sand filters to variable hydraulic and organic loading rates (HLR and OLR) in terms of biological oxygen demand (BODs), chemical oxygen demand (COD), total suspended solids (TSS), pH, electrical conductivity and Escherichia coli reductions were evaluated. The HLR was studied by increasing from 72 to 142 L m(-2) day(-1) and OLR was studied by increasing it from 23 to 30 g BOD5 m(-2) day(-1) while keeping the HLR constant at 142 L m(-2) day(-1). Each loading regime was applied for 110 days. Results showed that DCSF was able to remove >90% of organic matter and total suspended solids for all doses. No significant difference was noticed in terms of overall filter efficiency between different loads for all parameters. Significant reduction in BOD5 and COD (P water was drained through the third drawer in all tested loads. The paper concludes that DCSF would be appropriate for use in dense urban areas as its footprint is small and is appropriate for a wide range of users because of its convenience and low maintenance requirements.

  14. TAP usage in SIMBAD

    Science.gov (United States)

    Oberto, Anaïs, O.; Mantelet, Gregory; Wenger, Marc

    2015-09-01

    TAP (Table Access Protocol promoted by IVOA) is available on SIMBAD web site since July 2012. We will have a look of all kinds of uses and try to figure out how people use it in SIMBAD. Thanks to ADQL (Astronomical Data Query Language), everyone can write their own query using criteria on all data available in the database. In the SIMBAD database, more than 30 tables are available. It can be rather difficult to write a complex query. We will see how many joins between tables are used, and how many fields are used in the queries. The SIMBAD usage is going to change thanks to this new feature, a new way to search in the database.

  15. COMPUTER MODELING OF HYDRODYNAMIC PARAMETERS AT BOUNDARIES OF WATER INTAKE AREA WITH FILTERING INTAKE

    Directory of Open Access Journals (Sweden)

    Boronina Lyudmila Vladimirovna

    2012-12-01

    Full Text Available Improvement of water intake technologies are of great importance. These technologies are required to provide high quality water intake and treatment; they must be sufficiently simple and reliable, and they must be easily adjustable to particular local conditions. A mathematical model of a water supply area near the filtering water intake is proposed. On its basis, a software package designated for the calculation of parameters of the supply area along with its graphical representation is developed. To improve the efficiency of water treatment plants, the authors propose a new method of their integration into the landscape by taking account of velocity distributions in the water supply area within the water reservoir where the plant installation is planned. In the proposed relationship, the filtration rate and the scattering rate at the outlet of the supply area are taken into account, and they assure more precise projections of the inlet velocity. In the present study, assessment of accuracy of the mathematical model involving the scattering of a turbulent flow has been done. The assessment procedure is based on verification of the mean values equality hypothesis and on comparison with the experimental data. The results and conclusions obtained by means of the method developed by the authors have been verified through comparison of deviations of specific values calculated through the employment of similar algorithms in MathCAD, Maple and PLUMBING. The method of the water supply area analysis, with the turbulent scattering area having been taken into account, and the software package enable to numerically estimate the efficiency of the pre-purification process by tailoring a number of parameters of the filtering component of the water intake to the river hydrodynamic properties. Therefore, the method and the software package provide a new tool for better design, installation and operation of water treatment plants with respect to filtration and

  16. In situ bioremediation of trichloroethylene-contaminated water by a resting-cell methanotrophic microbial filter

    International Nuclear Information System (INIS)

    Taylor, R.T.; Duba, A.G.; Durham, W.B.; Hanna, M.L.; Jackson, K.J.; Jovanovich, M.C.; Knapp, R.B.; Knezovich, J.P.; Shah, N.N.; Shonnard, D.R.; Wijesinghe, A.M.

    1992-10-01

    The Lawrence Livermore National Laboratory is testing and developing an in situ microbial filter technology for remediating migrating subsurface plumes contaminated with low concentrations of trichloroethylene (TCE). Their current focus is the establishment of a replenishable bioactive zone (catalytic filter) along expanding plume boundaries by the Injection of a representative methanotrophic bacterium, Methylosinus trichosporium OB3b. We have successfully demonstrated this microbial filter strategy using emplaced, attached resting cells (no methane additions) in a 1.1-m flow-through test bed loaded with water-saturated sand. Two separate 24 h pulses of TCE (109 ppb and 85 ppb), one week apart, were pumped through the system at a flow velocity of 1.5 cm/h; no TCE (<0.5 ppb) was detected on the downstream side of the microbial filter. Subsequent excavation of the wet sand confirmed the existence of a TCE-bioactive zone 19 days after it had been created. An enhanced longevity of the cellular, soluble-form methane monooxygenase produced by this methanotroph Is a result of our laboratory bioreactor culturing conditions. Additional experiments with cells in sealed vials and emplaced in the 1.1-m test bed yielded a high resting-cell finite TCE biotransformation capacity of ∼ 0.25 mg per mg of bacteria; this is suitable for a planned sand-filled trench field demonstration at a Lawrence Livermore National Laboratory site

  17. Phosphate limitation in biological rapid sand filters used to remove ammonium from drinking water

    DEFF Research Database (Denmark)

    Lee, Carson Odell; Albrechtsen, Hans-Jørgen; Smets, Barth F.

    2013-01-01

    Removing ammonium from drinking water is important for maintaining biological stability in distribution systems. This is especially important in regions that do not use disinfectants in the treatment process or keep a disinfectant residual in the distribution system. Problems with nitrification can...... occur with increased ammonium loads caused by seasonal or operational changes and can lead to extensive periods of elevated ammonium and nitrite concentrations in the effluent. One possible cause of nitrification problems in these filters maybe due to phosphate limitation. This was investigated using...... the total number of ammonium oxidizing bacteria in the column. © 2013 American Water Works Association AWWA WQTC Conference Proceedings All Rights Reserved....

  18. Maximum Likelihood Ensemble Filter-based Data Assimilation with HSPF for Improving Water Quality Forecasting

    Science.gov (United States)

    Kim, S.; Riazi, H.; Shin, C.; Seo, D.

    2013-12-01

    Due to the large dimensionality of the state vector and sparsity of observations, the initial conditions (IC) of water quality models are subject to large uncertainties. To reduce the IC uncertainties in operational water quality forecasting, an ensemble data assimilation (DA) procedure for the Hydrologic Simulation Program - Fortran (HSPF) model has been developed and evaluated for the Kumho River Subcatchment of the Nakdong River Basin in Korea. The procedure, referred to herein as MLEF-HSPF, uses maximum likelihood ensemble filter (MLEF) which combines strengths of variational assimilation (VAR) and ensemble Kalman filter (EnKF). The Control variables involved in the DA procedure include the bias correction factors for mean areal precipitation and mean areal potential evaporation, the hydrologic state variables, and the water quality state variables such as water temperature, dissolved oxygen (DO), biochemical oxygen demand (BOD), ammonium (NH4), nitrate (NO3), phosphate (PO4) and chlorophyll a (CHL-a). Due to the very large dimensionality of the inverse problem, accurately specifying the parameters for the DA procdedure is a challenge. Systematic sensitivity analysis is carried out for identifying the optimal parameter settings. To evaluate the robustness of MLEF-HSPF, we use multiple subcatchments of the Nakdong River Basin. In evaluation, we focus on the performance of MLEF-HSPF on prediction of extreme water quality events.

  19. Performance Estimation for Lowpass Ternary Filters

    Directory of Open Access Journals (Sweden)

    O'Shea Peter

    2003-01-01

    Full Text Available Ternary filters have tap values limited to , , or . This restriction in tap values greatly simplifies the multipliers required by the filter, making ternary filters very well suited to hardware implementations. Because they incorporate coarse quantisation, their performance is typically limited by tap quantisation error. This paper derives formulae for estimating the achievable performance of lowpass ternary filters, thereby allowing the number of computationally intensive design iterations to be reduced. Motivated by practical communications systems requirements, the performance measure which is used is the worst-case stopband attenuation.

  20. One-step competitive lateral flow biosensor running on an independent quantification system for smart phones based in-situ detection of trace Hg(II) in tap water.

    Science.gov (United States)

    Cheng, Nan; Xu, Yuancong; Huang, Kunlun; Chen, Yuting; Yang, Zhansen; Luo, Yunbo; Xu, Wentao

    2017-01-01

    In this study, a one-step lateral flow biosensor (LFB) has been developed, optimized and validated for quantitative detection of Hg(II) in water. In the measurement principle, just one T-rich ssDNA probe (TSP) for the specific binding process was successfully employed in the competitive LFB based methods. The concept of an independent quantification system was realized using a cresol red dot as an external standard, which effectively eliminates false negative results. Under optimized conditions, the limit of detection for Hg(II) was 4nM; high selectivity towards Hg(II) and extraordinary device-to-device repeatability of the LFB were achieved. Furthermore, Hg(II) from tap water samples was analyzed, and the results were confirmed by ICP-MS. The interference from other components in the real samples could be neglected during the analysis. The approach provides a simple, sensitive, and practical tool for the detection of trace Hg(II) in tap water, showing great promise for in-situ applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. A HYBRID FILTER AND WRAPPER FEATURE SELECTION APPROACH FOR DETECTING CONTAMINATION IN DRINKING WATER MANAGEMENT SYSTEM

    Directory of Open Access Journals (Sweden)

    S. VISALAKSHI

    2017-07-01

    Full Text Available Feature selection is an important task in predictive models which helps to identify the irrelevant features in the high - dimensional dataset. In this case of water contamination detection dataset, the standard wrapper algorithm alone cannot be applied because of the complexity. To overcome this computational complexity problem and making it lighter, filter-wrapper based algorithm has been proposed. In this work, reducing the feature space is a significant component of water contamination. The main findings are as follows: (1 The main goal is speeding up the feature selection process, so the proposed filter - based feature pre-selection is applied and guarantees that useful data are improbable to be detached in the initial stage which discussed briefly in this paper. (2 The resulting features are again filtered by using the Genetic Algorithm coded with Support Vector Machine method, where it facilitates to nutshell the subset of features with high accuracy and decreases the expense. Experimental results show that the proposed methods trim down redundant features effectively and achieved better classification accuracy.

  2. Modeling Adsorption Based Filters (Bio-remediation of Heavy Metal Contaminated Water)

    Science.gov (United States)

    McCarthy, Chris

    I will discuss kinetic models of adsorption, as well as models of filters based on those mechanisms. These mathematical models have been developed in support of our interdisciplinary lab group, which is centered at BMCC/CUNY (City University of New York). Our group conducts research into bio-remediation of heavy metal contaminated water via filtration. The filters are constructed out of biomass, such as spent tea leaves. The spent tea leaves are available in large quantities as a result of the industrial production of tea beverages. The heavy metals bond with the surfaces of the tea leaves (adsorption). The models involve differential equations, stochastic methods, and recursive functions. I will compare the models' predictions to data obtained from computer simulations and experimentally by our lab group. Funding: CUNY Collaborative Incentive Research Grant (Round 12); CUNY Research Scholars Program.

  3. Pressurized water reactor monitoring. Study of detection, diagnostic and estimation methods (least error squares and filtering)

    International Nuclear Information System (INIS)

    Gillet, M.

    1986-07-01

    This thesis presents a study for the surveillance of the ''primary coolant circuit inventory monitoring'' of a pressurized water reactor. A reference model is developed in view of an automatic system ensuring detection and diagnostic in real time. The methods used for the present application are statistical tests and a method related to pattern recognition. The estimation of failures detected, difficult owing to the non-linearity of the problem, is treated by the least error squares method of the predictor or corrector type, and by filtering. It is in this frame that a new optimized method with superlinear convergence is developed, and that a segmented linearization of the model is introduced, in view of a multiple filtering [fr

  4. Design, construction and operation of a new filter approach for treatment of surface waters in Southeast Asia

    Science.gov (United States)

    Frankel, R. J.

    1981-05-01

    A simple, inexpensive, and efficient method of water treatment for rural communities in Southeast Asia was developed using local materials as filter media. The filter utilizes coconut fiber and burnt rice husks in a two-stage filtering process designed as a gravityfed system without the need for backwashing, and eliminates in most cases the need of any chemicals. The first-stage filter with coconut fiber acts essentially as a substitute for the coagulation and sedimentation phases of conventional water-treatment plants. The second-stage filter, using burnt rice husks, is similar to slow sand filtration with the additional benefits of taste, color and odor removals through the absorption properties of the activated carbon in the medium. This paper reports on the design, construction costs, and operating results of several village size units in Thailand and in the Philippines.

  5. Adaptive Kalman Filter Based on Adjustable Sampling Interval in Burst Detection for Water Distribution System

    Directory of Open Access Journals (Sweden)

    Doo Yong Choi

    2016-04-01

    Full Text Available Rapid detection of bursts and leaks in water distribution systems (WDSs can reduce the social and economic costs incurred through direct loss of water into the ground, additional energy demand for water supply, and service interruptions. Many real-time burst detection models have been developed in accordance with the use of supervisory control and data acquisition (SCADA systems and the establishment of district meter areas (DMAs. Nonetheless, no consideration has been given to how frequently a flow meter measures and transmits data for predicting breaks and leaks in pipes. This paper analyzes the effect of sampling interval when an adaptive Kalman filter is used for detecting bursts in a WDS. A new sampling algorithm is presented that adjusts the sampling interval depending on the normalized residuals of flow after filtering. The proposed algorithm is applied to a virtual sinusoidal flow curve and real DMA flow data obtained from Jeongeup city in South Korea. The simulation results prove that the self-adjusting algorithm for determining the sampling interval is efficient and maintains reasonable accuracy in burst detection. The proposed sampling method has a significant potential for water utilities to build and operate real-time DMA monitoring systems combined with smart customer metering systems.

  6. Development of biomass in a drinking water granular active carbon (GAC) filter.

    Science.gov (United States)

    Velten, Silvana; Boller, Markus; Köster, Oliver; Helbing, Jakob; Weilenmann, Hans-Ulrich; Hammes, Frederik

    2011-12-01

    Indigenous bacteria are essential for the performance of drinking water biofilters, yet this biological component remains poorly characterized. In the present study we followed biofilm formation and development in a granular activated carbon (GAC) filter on pilot-scale during the first six months of operation. GAC particles were sampled from four different depths (10, 45, 80 and 115 cm) and attached biomass was measured with adenosine tri-phosphate (ATP) analysis. The attached biomass accumulated rapidly on the GAC particles throughout all levels in the filter during the first 90 days of operation and maintained a steady state afterward. Vertical gradients of biomass density and growth rates were observed during start-up and also in steady state. During steady state, biomass concentrations ranged between 0.8-1.83 x 10(-6) g ATP/g GAC in the filter, and 22% of the influent dissolved organic carbon (DOC) was removed. Concomitant biomass production was about 1.8 × 10(12) cells/m(2)h, which represents a yield of 1.26 × 10(6) cells/μg. The bacteria assimilated only about 3% of the removed carbon as biomass. At one point during the operational period, a natural 5-fold increase in the influent phytoplankton concentration occurred. As a result, influent assimilable organic carbon concentrations increased and suspended bacteria in the filter effluent increased 3-fold as the direct consequence of increased growth in the biofilter. This study shows that the combination of different analytical methods allows detailed quantification of the microbiological activity in drinking water biofilters. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Activated soil filters for removal of biocides from contaminated run-off and waste-waters.

    Science.gov (United States)

    Bester, Kai; Banzhaf, Stefan; Burkhardt, Michael; Janzen, Niklas; Niederstrasser, Bernd; Scheytt, Traugott

    2011-11-01

    Building facades can be equipped with biocides to prevent formation of algal, fungal and bacterial films. Thus run-off waters may contain these highly active compounds. In this study, the removal of several groups of biocides from contaminated waters by means of an activated soil filter was studied. A technical scale activated vertical soil filter (biofilter) with different layers (peat, sand and gravel), was planted with reed (Phragmites australis) and used to study the removal rates and fate of hydrophilic to moderate hydrophobic (log K(ow) 1.8-4.4) biocides and biocide metabolites such as: Terbutryn, Cybutryn (Irgarol® 1051), Descyclopropyl-Cybutryn (Cybutryn and Terbutryn metabolite), Isoproturon, Diuron, and its metabolite Diuron-desmonomethyl, Benzo-isothiazolinone, n-Octyl-isothiazolinone, Dichloro-n-octylisothiazolinone and Iodocarbamate (Iodocarb). Three experiments were performed: the first one (36 d) under low flow conditions (61 L m(-2) d(-1)) reached removal rates between 82% and 100%. The second one was performed to study high flow conditions: During this experiment, water was added as a pulse to the filter system with a hydraulic load of 255 L m(-2) within 5 min (retention time waters or infiltration into soil without appropriate removal. In the last experiment the removal efficiencies of the different layers were studied. Though the peat layer was responsible for most of the removal, the sand and gravel layers also contributed significantly for some compounds. All compounds are rather removed by degradation than by sorption. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Efficient multichannel acoustic echo cancellation using constrained tap selection schemes in the subband domain

    Science.gov (United States)

    Desiraju, Naveen Kumar; Doclo, Simon; Wolff, Tobias

    2017-12-01

    Acoustic echo cancellation (AEC) is a key speech enhancement technology in speech communication and voice-enabled devices. AEC systems employ adaptive filters to estimate the acoustic echo paths between the loudspeakers and the microphone(s). In applications involving surround sound, the computational complexity of an AEC system may become demanding due to the multiple loudspeaker channels and the necessity of using long filters in reverberant environments. In order to reduce the computational complexity, the approach of partially updating the AEC filters is considered in this paper. In particular, we investigate tap selection schemes which exploit the sparsity present in the loudspeaker channels for partially updating subband AEC filters. The potential for exploiting signal sparsity across three dimensions, namely time, frequency, and channels, is analyzed. A thorough analysis of different state-of-the-art tap selection schemes is performed and insights about their limitations are gained. A novel tap selection scheme is proposed which overcomes these limitations by exploiting signal sparsity while not ignoring any filters for update in the different subbands and channels. Extensive simulation results using both artificial as well as real-world multichannel signals show that the proposed tap selection scheme outperforms state-of-the-art tap selection schemes in terms of echo cancellation performance. In addition, it yields almost identical echo cancellation performance as compared to updating all filter taps at a significantly reduced computational cost.

  9. Repartition of oil miscible and water soluble UV filters in an applied sunscreen film determined by confocal Raman microspectroscopy.

    Science.gov (United States)

    Sohn, Myriam; Buehler, Theodor; Imanidis, Georgios

    2016-07-06

    Photoprotection provided by topical sunscreens is expressed by the sun protection factor (SPF) which depends primarily on the UV filters contained in the product and the applied sunscreen amount. Recently, the vehicle was shown to significantly impact film thickness distribution of an applied sunscreen and sunscreen efficacy. In the present work, repartition of the UV filters within the sunscreen film upon application is investigated for its role to affect sun protection efficacy. The spatial repartition of an oil-miscible and a water-soluble UV filter within the sunscreen film was studied using confocal Raman microspectroscopy. Epidermis of pig ear skin was used as substrate for application of three different sunscreen formulations, an oil-in-water emulsion, a water-in-oil emulsion, and a clear lipo-alcoholic spray (CAS) and SPF in vitro was measured. Considerable differences in the repartition of the UV filters upon application and evaporation of volatile ingredients were found between the tested formulations. A nearly continuous phase of lipid-miscible UV filter was formed only for the WO formulation with dispersed aggregates of water-soluble UV filter. OW emulsion and CAS exhibited interspersed patches of the two UV filters, whereas the segregated UV filter domains of the latter formulation were by comparison of a much larger scale and spanned the entire thickness of the sunscreen film. CAS therefore differed markedly from the other two formulations with respect to filter repartition. This difference should be reflected in SPF when the absorption spectra of the employed UV filters are not the same. Confocal Raman microspectroscopy was shown to be a powerful technique for studying this mechanism of sun protection performance of sunscreens.

  10. Experimental Comparison of the Reproductive Outcomes and Early Development of the Offspring of Rats Given Five Common Types of Drinking Water

    Science.gov (United States)

    Zeng, Hui; Shu, Wei-qun; Chen, Ji-an; Liu, Lin; Wang, Da-hua; Fu, Wen-juan; Wang, Ling-qiao; Luo, Jiao-hua; Zhang, Liang; Tan, Yao; Qiu, Zhi-qun; Huang, Yu-jing

    2014-01-01

    Tap water (unfiltered), filtered tap water and processed bottled water (purified water, artificial mineralized water, or natural water) are now the five most widely consumed types of drinking water in China. However, the constituents (organic chemicals and inorganic ingredients) of the five waters differ, which may cause them to have different long-term health effects on those who drink them, especially sensitive children. In order to determine which type of water among the five waters is the most beneficial regarding reproductive outcomes and the developmental behaviors of offspring, two generations of Sprague–Dawley rats were given these five waters separately, and their reproductive outcomes and the developmental behaviors of their offspring were observed and compared. The results showed that the unfiltered tap water group had the lowest values for the maternal gestation index (MGI) and offspring's learning and memory abilities (OLMA); the lowest offspring survival rate was found in the purified water group; and the highest OLMA were found in the filtered tap water group. Thus, the best reproductive and offspring early developmental outcomes were found in the group that drank filtered tap water, which had the lowest levels of pollutants and the richest minerals. Therefore, thoroughly removing toxic contaminants and retaining the beneficial minerals in drinking water may be important for both pregnant women and children, and the best way to treat water may be with granular activated carbon and ion exchange by copper zinc alloy. PMID:25279561

  11. Experimental comparison of the reproductive outcomes and early development of the offspring of rats given five common types of drinking water.

    Directory of Open Access Journals (Sweden)

    Hui Zeng

    Full Text Available Tap water (unfiltered, filtered tap water and processed bottled water (purified water, artificial mineralized water, or natural water are now the five most widely consumed types of drinking water in China. However, the constituents (organic chemicals and inorganic ingredients of the five waters differ, which may cause them to have different long-term health effects on those who drink them, especially sensitive children. In order to determine which type of water among the five waters is the most beneficial regarding reproductive outcomes and the developmental behaviors of offspring, two generations of Sprague-Dawley rats were given these five waters separately, and their reproductive outcomes and the developmental behaviors of their offspring were observed and compared. The results showed that the unfiltered tap water group had the lowest values for the maternal gestation index (MGI and offspring's learning and memory abilities (OLMA; the lowest offspring survival rate was found in the purified water group; and the highest OLMA were found in the filtered tap water group. Thus, the best reproductive and offspring early developmental outcomes were found in the group that drank filtered tap water, which had the lowest levels of pollutants and the richest minerals. Therefore, thoroughly removing toxic contaminants and retaining the beneficial minerals in drinking water may be important for both pregnant women and children, and the best way to treat water may be with granular activated carbon and ion exchange by copper zinc alloy.

  12. Removal of diclofenac from surface water by electron beam irradiation combined with a biological aerated filter

    Science.gov (United States)

    He, Shijun; Wang, Jianlong; Ye, Longfei; Zhang, Youxue; Yu, Jiang

    2014-12-01

    The degradation of DCF was investigated in aqueous solution by using electron beam (EB) technology. When the initial concentration was between 10 and 40 mg/L, almost 100% of the DCF was degraded at a dose of 0.5 kGy. However, only about 6.5% of DCF was mineralized even at 2 kGy according to total organic carbon (TOC) measurements. A combined process of EB and biological aerated filter (BAF) was therefore developed to enhance the treatment of DCF contaminated surface water. The effluent quality of combined process was substantially improved by EB pretreatment due to the degradation of DCF and related intermediates. Both irradiation and biological treatment reduced the toxicity of the treated water. The experimental results showed that EB is effective for removing DCF from artificial aqueous solution and real surface water.

  13. Reverse Osmosis Filter Use and High Arsenic Levels in Private Well Water

    Science.gov (United States)

    George, Christine M.; Smith, Allan H.; Kalman, David A.; Steinmaus, Craig M.

    2013-01-01

    Inorganic arsenic causes cancer, and millions of people worldwide are exposed to arsenic-contaminated water. Regulatory standards for arsenic levels in drinking water generally do not apply to private domestic wells. Reverse osmosis (RO) units commonly are used by well owners to reduce arsenic concentrations, but may not always be effective. In a survey of 102 homes in Nevada, 19 used RO devices. Pre- and post-RO filtration arsenic concentrations averaged 443 μg/l and 87 μg/l, respectively. The average absolute and percent reductions in arsenic concentrations after filtration were 356 μg/l and 79%, respectively. Postfiltration concentrations were higher than 10 μg/l in 10 homes and higher than 100 μg/l in 4 homes. These findings provide evidence that RO filters do not guarantee safe drinking water and, despite regulatory standards, some people continue to be exposed to very high arsenic concentrations. PMID:17867571

  14. Construction and optimisation of a cartridge filter for removing fluoride in drinking water

    Directory of Open Access Journals (Sweden)

    G. Wrensford

    2004-06-01

    Full Text Available An attempt has been made to construct a cartridge to be used for the defluoridation of drinking water. The cartridge packed with bone char material could be fixed onto a domestic faucet as a flow through defluoridizer. PVC cartridges of various sizes were made from a ¾ inch pipe. The efficiency of fluoride removal was determined for the following parameters: cartridge length, flow rate of water, compactness of bone char material and particle size with the aim of determining the optimum conditions for a good cartridge. It was found that the optimal conditions for the F- filter that gave the best results in removing of F- from water with minimum inconvenience were: particle size, 0.2 mm mean diameter; the flow rate, equal or less than 20 mL/min; cartridge length, 10 cm filled with 20 g of bone char material.

  15. Biological filters and their use in potable water filtration systems in spaceflight conditions

    Science.gov (United States)

    Thornhill, Starla G.; Kumar, Manish

    2018-05-01

    Providing drinking water to space missions such as the International Space Station (ISS) is a costly requirement for human habitation. To limit the costs of water transport, wastewater is collected and purified using a variety of physical and chemical means. To date, sand-based biofilters have been designed to function against gravity, and biofilms have been shown to form in microgravity conditions. Development of a universal silver-recycling biological filter system that is able to function in both microgravity and full gravity conditions would reduce the costs incurred in removing organic contaminants from wastewater by limiting the energy and chemical inputs required. This paper aims to propose the use of a sand-substrate biofilter to replace chemical means of water purification on manned spaceflights.

  16. [Water-filtered infrared-A (wIRA) promotes wound healing].

    Science.gov (United States)

    Winkel, R; Hoffmann, G; Hoffmann, R

    2014-11-01

    Water-filtered infrared-A (wIRA) is a special form of heat radiation with high tissue penetration and low thermal load to the skin surface which promotes the healing of acute and chronic wounds both by thermal and thermic as well as by non-thermal and non-thermic effects. Water-filtered infrared-A increases tissue temperature (+ 2.7 °C at a tissue depth of 2 cm), tissue oxygen partial pressure (+ 32 % at a tissue depth of 2 cm) and tissue perfusion. These three factors are decisive for a sufficient supply of tissue with energy and oxygen and consequently also for wound healing and infection defense. Water-filtered infrared-A promotes normal as well as disturbed wound healing by diminishing inflammation and exudation, by promotion of infection defense and regeneration, and by alleviation of pain. These effects have been proven in a total of seven prospective studies (of these six randomized controlled studies) with most of the effects having an evidence level of Ia or Ib. The additional cases of complicated courses of wound healing presented in this article illustrate the proven effects of wIRA. Not only in the 6 presented cases wIRA turned the complicated courses of wound healing for the better and facilitated the healing of the wounds after varying total times of irradiation (in the 6 cases 51-550 h) and after variable times of wound care and mostly after transplantation of split skin grafts. In complicated courses of wound healing wIRA does not replace consultation and, when indicated, treatment by an experienced plastic surgeon and by a surgeon specialized in septic surgery. With these limitations wIRA can be recommended as a valuable complement for the treatment of acute as well as of chronic wounds.

  17. Fabrication of antibacterial water filter by coating silver nanoparticles on flexible polyurethane foams

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Thi Phuong Phong; Ngo Vo Ke Thanh; Phan Hue Phuong [Laboratory for Nanotechnology, Vietnam National University-Ho Chi Minh City Community 6, Linh Trung Ward, Thu Duc District, Ho Chi Minh City (Viet Nam)], E-mail: ntpphong@vnuhcm.edu.vn

    2009-09-01

    In this paper, we fabricated silver-coated polyurethane foams and used it as a bacterial filter for contaminated drinking water. Flexible PU foams were soaked in silver colloidal solutions for 10 h, then washed and air-dried at room temperature. The prepared silver colloidal solutions and silver-coated PU materials were characterized by several techniques including TEM, FESEM/EDS, UV-VIS, ICP-AAS, and Raman spectroscopy. The TEM images showed that the size of silver nanoparticles in colloidal solutions varies from 6 to 12nm. The Raman, FE-SEM/EDS and ICP-AAS data illustrated that silver nanoparticles were stable on the PU foam and were not washed away by water. Furthermore, the microbiological tests (tube tests and flow test) were carried out on silver-coated PU materials with the Coliforms, E. coli, and B. subtilis. The obtained results showed that the bacteria was killed completely with antibacterial efficiency of 100% being observed. Our research suggests that silver-coated polyurethane foams can be used as excellent antibacterial water filters and would have several applications in other sectors.

  18. Assessment of addition of biochar to filtering mixtures for potential water pollutant removal.

    Science.gov (United States)

    Piscitelli, Lea; Rivier, Pierre-Adrien; Mondelli, Donato; Miano, Teodoro; Joner, Erik J

    2018-01-01

    Green roofs are used increasingly to alleviate peaks of water discharge into the sewage systems in urban areas. Surface runoff from roofs contain pollutants from dry and wet deposition, and green roofs offer a possibility to reduce the amounts of pollutants in the water discharged from roofs by degradation and filtering. These pollutants would otherwise enter wastewater treatments plants and ultimately end up in sewage sludge that is spread on agricultural soils. The most common substrates used in green roofs have limited capacity for filtration and sorption. Also, more sustainable alternatives are sought, due to the high carbon footprint of these materials. Biochar is a carbon-rich material produced by pyrolysis of biomass, and several types of biochar have been described as good sorbents and filter materials. Biochar is also a light and carbon negative material, which may fulfill other desired criteria for new green roof substrates. We here report on an experiment where two types of biochar, produced from olive husks at 450 °C or from forest waste at 850 ° C were mixed with volcanic rock or peat, and tested for retention capacity of phenanthrene and six heavy metals in a column experiment with unsaturated gravimetric water flow lasting for 3 weeks. The results suggest that biochar as a component in green roof substrates perform better than traditional materials, concerning retention of the tested pollutants, and that different types of biochar have different properties in this respect.

  19. Analysis of up-flow aerated biological activated carbon filter technology in drinking water treatment.

    Science.gov (United States)

    Lu, Shaoming; Liu, Jincui; Li, Shaowen; Biney, Elizabeth

    2013-01-01

    Problems have been found in the traditional post-positioned down-flow biological activated carbon filter (DBACF), such as microorganism leakage and low biodegradability. A pilot test was carried out to place a BACF between the sediment tank and the sand filter; a new technology of dual media up-flow aerated biological activated carbon filter (UBACF) was developed. Results showed that in terms of the new process, the up-flow mode was better than the down-flow. Compared with the DBACF, the problem of microorganism leakage could be well resolved with the UBACF process by adding disinfectant before the sand filtration, and a similar adsorption effect could be obtained. For the tested raw water, the COD(Mn) and NH3-N removal rate was 54.6% and 85.0%, respectively, similar to the waterworks with the DBACF process. The UBACF greatly enhanced oxygen supply capability and mass transfer rate via aeration, and the NH3-N removal ability was significantly improved from 1.5 mg/L to more than 3 mg/L. Influent to the UBACF with higher turbidity could be coped with through the primary filtration of the ceramisite layer combined with fluid-bed technology, which gave the carbon bed a low-turbidity environment of less than 1.0 NTU. The backwashing parameters and carbon abrasion rate of the two processes were almost the same.

  20. Retention of radium from thermal waters on sand filters and adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Elejalde, C. [Dpto. de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria, Alameda de Urquijo s/n, 48013 Bilbao (Spain)]. E-mail: inpelsac@bi.ehu.es; Herranz, M. [Dpto. de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria, Alameda de Urquijo s/n, 48013 Bilbao (Spain); Idoeta, R. [Dpto. de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria, Alameda de Urquijo s/n, 48013 Bilbao (Spain); Legarda, F. [Dpto. de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria, Alameda de Urquijo s/n, 48013 Bilbao (Spain); Romero, F. [Dpto. de Ingenieria Quimica y del Medio Ambiente, Escuela Tecnica Superior de Ingenieria, Alameda de Urquijo s/n, 48013 Bilbao (Spain); Baeza, A. [Dpto. de Fisica, Facultad de Veterinaria, Universidad de Extremadura, Avda. Universidad s/n, 10071 Caceres (Spain)

    2007-06-18

    This study was focussed on laboratory experiences of retention of radium from one thermal water on sand filters and adsorbents, trying to find an easy method for the elimination in drinkable waters polluted with this natural radio-nuclide. A thermal water from Cantabria (Spain) was selected for this work. Retention experiences were made with columns of 35 mm of diameter containing 15 cm layers of washed river sand or 4 cm layers of zeolite A3, passing known volumes of thermal water at flows between 4 and 40 ml/min with control of the retained radium by determining the amount in the water after the treatment. The statistical analysis of data suggests that retention depends on the flow and the volume passed through the columns. As additional adsorbents were used kaolin and a clay rich in illite. Jar-test experiences were made agitating known weights of adsorbents with the selected thermal water, with addition of flocculants and determination of radium in filtrated water after the treatment. Data suggest that retention is related to the weight of adsorbent used, but important quantities of radium seem remain in solution for higher amounts of adsorbents, according to the statistical treatment of data. The elution of retained radium from columns or adsorbents, previously used in experiences, should be the aim of a future research.

  1. Retention of radium from thermal waters on sand filters and adsorbents

    International Nuclear Information System (INIS)

    Elejalde, C.; Herranz, M.; Idoeta, R.; Legarda, F.; Romero, F.; Baeza, A.

    2007-01-01

    This study was focussed on laboratory experiences of retention of radium from one thermal water on sand filters and adsorbents, trying to find an easy method for the elimination in drinkable waters polluted with this natural radio-nuclide. A thermal water from Cantabria (Spain) was selected for this work. Retention experiences were made with columns of 35 mm of diameter containing 15 cm layers of washed river sand or 4 cm layers of zeolite A3, passing known volumes of thermal water at flows between 4 and 40 ml/min with control of the retained radium by determining the amount in the water after the treatment. The statistical analysis of data suggests that retention depends on the flow and the volume passed through the columns. As additional adsorbents were used kaolin and a clay rich in illite. Jar-test experiences were made agitating known weights of adsorbents with the selected thermal water, with addition of flocculants and determination of radium in filtrated water after the treatment. Data suggest that retention is related to the weight of adsorbent used, but important quantities of radium seem remain in solution for higher amounts of adsorbents, according to the statistical treatment of data. The elution of retained radium from columns or adsorbents, previously used in experiences, should be the aim of a future research

  2. Use, microbiological effectiveness and health impact of a household water filter intervention in rural Rwanda-A matched cohort study.

    Science.gov (United States)

    Kirby, Miles A; Nagel, Corey L; Rosa, Ghislaine; Umupfasoni, Marie Mediatrice; Iyakaremye, Laurien; Thomas, Evan A; Clasen, Thomas F

    2017-08-01

    Unsafe drinking water is a substantial health risk contributing to child diarrhoea. We investigated impacts of a program that provided a water filter to households in rural Rwandan villages. We assessed drinking water quality and reported diarrhoea 12-24 months after intervention delivery among 269 households in the poorest tertile with a child under 5 from 9 intervention villages and 9 matched control villages. We also documented filter coverage and use. In Round 1 (12-18 months after delivery), 97.4% of intervention households reported receiving the filter, 84.5% were working, and 86.0% of working filters contained water. Sensors confirmed half of households with working filters filled them at least once every other day on average. Coverage and usage was similar in Round 2 (19-24 months after delivery). The odds of detecting faecal indicator bacteria in drinking water were 78% lower in the intervention arm than the control arm (odds ratio (OR) 0.22, 95% credible interval (CrI) 0.10-0.39, p<0.001). The intervention arm also had 50% lower odds of reported diarrhoea among children <5 than the control arm (OR=0.50, 95% CrI 0.23-0.90, p=0.03). The protective effect of the filter is also suggested by reduced odds of reported diarrhoea-related visits to community health workers or clinics, although these did not reach statistical significance. Copyright © 2017 Elsevier GmbH. All rights reserved.

  3. Physics of Beer Tapping

    Science.gov (United States)

    Rodríguez-Rodríguez, Javier; Casado-Chacón, Almudena; Fuster, Daniel

    2014-11-01

    The popular bar prank known in colloquial English as beer tapping consists in hitting the top of a beer bottle with a solid object, usually another bottle, to trigger the foaming over of the former within a few seconds. Despite the trick being known for a long time, to the best of our knowledge, the phenomenon still lacks scientific explanation. Although it seems natural to think that shock-induced cavitation enhances the diffusion of CO2 from the supersaturated bulk liquid into the bubbles by breaking them up, the subtle mechanism by which this happens remains unknown. Here, we show that the overall foaming-over process can be divided into three stages where different physical phenomena take place in different time scales: namely, the bubble-collapse (or cavitation) stage, the diffusion-driven stage, and the buoyancy-driven stage. In the bubble-collapse stage, the impact generates a train of expansion-compression waves in the liquid that leads to the fragmentation of preexisting gas cavities. Upon bubble fragmentation, the sudden increase of the interface-area-to-volume ratio enhances mass transfer significantly, which makes the bubble volume grow by a large factor until CO2 is locally depleted. At that point buoyancy takes over, making the bubble clouds rise and eventually form buoyant vortex rings whose volume grows fast due to the feedback between the buoyancy-induced rising speed and the advection-enhanced CO2 transport from the bulk liquid to the bubble. The physics behind this explosive process sheds insight into the dynamics of geological phenomena such as limnic eruptions.

  4. Tapping a new energy source

    International Nuclear Information System (INIS)

    Thomas, W.

    1999-01-01

    The Sable Offshore Energy Project is one of Canada's largest construction projects which is bringing a new industry to Nova Scotia. A five-party consortium comprised of Mobil Oil Canada, Shell Canada, Imperial Oil, Nova Scotia Resources and Mosbacher, has formed an enterprise called Sable Offshore Energy Inc. The consortium plans to bring natural gas to markets in Canada and the United States before the end of 1999. The Santa Fe Galaxy II is one of the world's most modern marine all-weather drilling rigs that will soon begin the drilling of wells. Once in production, the project will produce half a billion cubic feet of natural gas daily from three production platforms that will tap three separate undersea natural gas fields. The gas will then be transported 200 km to shore near Goldboro, Nova Scotia, through an undersea pipeline. There, it will be treated to remove any remaining water and to separate liquid natural gas from the gas proper. The natural gas liquids will then be carried by an onshore pipeline to a new facility at Point Tupper where they will be processed into propane, butane and condensate. There will be enough gas to meet the potential demand in Nova Scotia and New Brunswick. Large urban centres such as Halifax and Saint John will be served by secondary lines that branch off the main pipeline, but developing smaller markets will take time because the necessary infrastructure does not yet exist. The project has already created thousands of jobs in the province. 5 figs

  5. Evaluation of Plastic Household Biosand Filter (BSF) In Combination with Solar Disinfection (SODIS) For Water Treatment

    International Nuclear Information System (INIS)

    Hussain, G.; Haydar, S.; Bari, A. J.; Anis, M.; Asif, Z.; Aziz, J. A.

    2015-01-01

    Efficiency of a household plastic biosand filter (BSF) for the removal of turbidity and fecal contamination was evaluated. Water of river Ravi was used as influent. Water filtered through BSF was further treated using Solar Disinfection (SODIS). The study was conducted for raw water with low pollution level (total coliforms <500 MPN/100 ml) and high pollution level (total coliforms between 500-20,000 MPN/100 ml). The average value of turbidity removal by BSF was 94.5 percentage with 0.9 NTU as average turbidity of effluent. For raw water with low pollution level, the BSF was able to achieve a maximum of 2.2 log10 unit reduction (99.4 percentage) for total coliforms (39 MPN/100 mL in effluent) and 1.95 log10 unit reduction (98.5 percentage) for fecal coliforms (9 MPN/100 mL in effluent). While for raw water with high pollution level, the maximum removal of 1.5 log10 unit (97.5 percentage) for total coliforms (1430 MPN/100 mL in effluent) and 1.8 log10 units (98.4 percentage) for fecal coliforms (387 MPN/100 mL in effluent) was achieved in BSF. To make the effluent fit for drinking it was further treated using SODIS, which rendered the BSF effluent fit for drinking with zero fecal coliforms count (for full sunny and partially cloudy conditions). Newly proposed plastic BSF could be a good replacement of already used concrete household BSF (used in more than 63 countries) being cheaper in cost and lighter in weight by 85 percentage and 80 percentage, respectively than the concrete BSF. (author)

  6. [Evaluation of drinking-water treatment by Lifestraw® and Ceramic-pot filters].

    Science.gov (United States)

    Pérez-Vidal, Andrea; Díaz-Gómez, Jaime; Salamanca-Rojas, Karen L; Rojas-Torres, Leidy Y

    2016-04-01

    Objective To evaluate under laboratory conditions, the removal efficiency of turbidity and E. coli of two household water filters: LifeStraw® family (MF) and ceramic pot filter (CPF). Methods The two systems were operated over 6 months using two identical control units per system, treating 7.5 L/d of a synthetic substrate used as raw water. The turbidity of the substrate was adjusted with Kaolinite and the E. coli concentration, with a replica of the ATCC 95922 strain. The differences of effluent quality of the systems, in terms of turbidity and E. coli, were evaluated with Analysis of Variance (ANOVA). Operative and maintenance aspects, that could limit or enhance the use of the systems, were also considered in the evaluation. Results The water synthetic substrate quality had an average of 32.2 ± 2.8 NTU for turbidity and 3,9x105 UFC/100 mL for E. coli. Both systems reduce the turbidity to values below 2 NTU with an inactivation of 100 % of E. coli. Statistical differences were found between the systems in terms of turbidity removal, MF being more efficient than the CPF (99,2 ± 0.4 % and 97.6 % ± 1.14, respectively). Conclusions Both systems are suitable for household water supply treatment, acheiving the water quality standards established by Colombian regulations. The MF was more efficient for suspended solids removal and filtration rate, but when economic, operative, and maintenance aspects along with social acceptability and lifespan are considered, the CPF seems more suitable, especially in rural areas.

  7. Synergistic Water-Treatment Reactors Using a TiO2-Modified Ti-Mesh Filter

    Directory of Open Access Journals (Sweden)

    Akira Fujishima

    2013-07-01

    Full Text Available The recent applications of a TiO2-modified Ti-mesh filter (TMiP™ for water purification are summarized with newly collected data including biological assays as well as sewage water treatment. The water purification reactors consist of the combination of a TMiP, a UV lamp, an excimer VUV lamp, and an ozonation unit. The water purification abilities of the reactor were evaluated by decomposition of organic contaminants, inactivation of waterborne pathogens, and treatment efficiency for sewage water. The UV-C/TMiP/O3 reactor disinfected E. coli in aqueous suspension in approximately 1 min completely, and also decreased the number of E. coli in sewage water in 15 min dramatically. The observed rate constants of 7.5 L/min and 1.3 L/min were calculated by pseudo-first-order kinetic analysis respectively. Although organic substances in sewage water were supposed to prevent the UV-C/TMiP/O3 reactor from purifying water, the reactor reduced E. coli in sewage water continuously. On the other hand, although much higher efficiencies for decomposition of organic pollutants in water were achieved in the excimer/TMiP reactor, the disinfection activity of the reactor for waterborne pathogens was not as effective as the other reactors. The difference of efficiency between organic pollutants and waterborne pathogens in the excimer/TMiP reactor may be due to the size, the structure, and the decomposition mechanism of the organic pollutants and waterborne pathogens. These results show that a suitable system assisted by synergy of photocatalysts and other technologies such as ozonation has a huge potential as a practical wastewater purification system.

  8. Improving water quality forecasting via data assimilation - Application of maximum likelihood ensemble filter to HSPF

    Science.gov (United States)

    Kim, Sunghee; Seo, Dong-Jun; Riazi, Hamideh; Shin, Changmin

    2014-11-01

    An ensemble data assimilation (DA) procedure is developed and evaluated for the Hydrologic Simulation Program - Fortran (HSPF), a widely used watershed water quality model. The procedure aims at improving the accuracy of short-range water quality prediction by updating the model initial conditions (IC) based on real-time observations of hydrologic and water quality variables. The observations assimilated include streamflow, biochemical oxygen demand (BOD), dissolved oxygen (DO), chlorophyll a (CHL-a), nitrate (NO3), phosphate (PO4) and water temperature (TW). The DA procedure uses the maximum likelihood ensemble filter (MLEF), which is capable of handling both nonlinear model dynamics and nonlinear observation equations, in a fixed-lag smoother formulation. For evaluation, the DA procedure was applied to the Kumho Catchment of the Nakdong River Basin in the Republic of Korea. A set of performance measures was used to evaluate analysis and prediction of streamflow and water quality variables. To remove systematic errors in the model simulation originating from structural and parametric errors, a parsimonious bias correction procedure is incorporated into the observation equation. The results show that the DA procedure substantially improves predictive skill for most variables; reduction in root mean square error ranges from 11% to 60% for Day-1 through 3 predictions for all observed variables except DO. It is seen that MLEF handles highly nonlinear hydrologic and biochemical observation equations very well, and that it is an effective DA technique for water quality forecasting.

  9. Modeling the Performance of Biological Rapid Sand Filters Used to Remove Ammonium, Iron, and Manganese From Drinking Water

    DEFF Research Database (Denmark)

    Lee, Carson; Albrechtsen, Hans-Jørgen; Smets, Barth F.

    activated carbon and are often used following ozonation to remove additional biodegradable organics created during ozonation. In Europe, biological filters are also used to remove ammonium and reduced forms of iron and manganese. These compounds can cause biological instability in the distribution system...... for chlorine addition following treatment. Under the normal conditions found in many water treatment plants, reduced iron can be oxidized through aeration and the precipitates can be captured by the filter media. Ammonium and manganese can be removed biologically. This research uses both pilot and full scale...... studies to determine how operating conditions affect the performance of the filters. Substrate concentrations, particle/precipitate accumulation, and biomass kinetics are monitored throughout the depth of the filter and over the operational cycle of the filter. Tracer tests, using a conservative salt...

  10. Evaluation of drinking water treatment combined filter backwash water recycling technology based on comet and micronucleus assay.

    Science.gov (United States)

    Chen, Ting; Xu, Yongpeng; Liu, Zhiquan; Zhu, Shijun; Shi, Wenxin; Cui, Fuyi

    2016-04-01

    Based on the fact that recycling of combined filter backwash water (CFBW) directly to drinking water treatment plants (WTP) is considered to be a feasible method to enhance pollutant removal efficiency, we were motivated to evaluate the genotoxicity of water samples from two pilot-scale drinking water treatment systems, one with recycling of combined backwash water, the other one with a conventional process. An integrated approach of the comet and micronucleus (MN) assays was used with zebrafish (Danio rerio) to investigate the water genotoxicity in this study. The total organic carbon (TOC), dissolved organic carbon (DOC), and trihalomethane formation potential (THMFP), of the recycling process were lower than that of the conventional process. All the results showed that there was no statistically significant difference (P>0.05) between the conventional and recycling processes, and indicated that the genotoxicity of water samples from the recycling process did not accumulate in 15 day continuous recycling trial. It was worth noting that there was correlation between the concentrations of TOC, DOC, UV254, and THMFPs in water and the DNA damage score, with corresponding R(2) values of 0.68, 0.63, 0.28, and 0.64. Nevertheless, both DNA strand breaks and MN frequency of all water samples after disinfection were higher than that of water samples from the two treatment units, which meant that the disinfection by-products (DBPs) formed by disinfection could increase the DNA damage. Both the comet and MN tests suggest that the recycling process did not increase the genotoxicity risk, compared to the traditional process. Copyright © 2015. Published by Elsevier B.V.

  11. Recreational water quality response to a filtering barrier at a Great Lakes beach

    Science.gov (United States)

    Przybyla-Kelly, Kasia; Nevers, Meredith; Breitenbach, Cathy; Whitman, Richard L.

    2013-01-01

    Recent research has sought to determine the off- or onshore origin of fecal indicator bacteria (FIB) in order to improve local recreational water quality. In an effort to reduce offshore contamination, a filtering barrier (FB) was installed at Calumet Beach, Lake Michigan, Chicago, IL. A horseshoe-shaped curtain (146 m long, 0.18 mm apparent opening size, 1.5–1.6 m deepest point) was designed to exclude FIB containing or promoting debris and thus reduce the number of swimming advisories during the examination period of July through September 2012. Mean water Escherichia coli concentrations were significantly lower at southern transects (S; outside FB) than at transects within the FB (WN) and at northern transects (N; outside FB) (1.45 log (MPN)/100 ml vs. 1.74 and 1.72, respectively, p sources of contamination and nearshore dynamics that may direct future beach management strategies.

  12. A Method of Effective Quarry Water Purifying Using Artificial Filtering Arrays

    Science.gov (United States)

    Tyulenev, M.; Garina, E.; Khoreshok, A.; Litvin, O.; Litvin, Y.; Maliukhina, E.

    2017-01-01

    The development of open pit mining in the large coal basins of Russia and other countries increases their negative impact on the environment. Along with the damage of land and air pollution by dust and combustion gases of blasting, coal pits have a significant negative impact on water resources. Polluted quarry water worsens the ecological situation on a much larger area than covered by air pollution and land damage. This significantly worsens the conditions of people living in cities and towns located near the coal pits, and complicates the subsequent restoration of the environment, irreversibly destroying the nature. Therefore, the research of quarry wastewater purifying is becoming an important mater for scholars of technical colleges and universities in the regions with developing open-pit mining. This paper describes the method of determining the basic parameters of the artificial filtering arrays formed on coal pits of Kuzbass (Western Siberia, Russia), and gives recommendations on its application.

  13. Importance of copper for nitrification in biological rapid sand filters for drinking water production

    DEFF Research Database (Denmark)

    Wagner, Florian Benedikt

    nitrification during drinking water production provided the motivation to investigate if a lack of copper could be responsible for the problems in nitrifying biofilters. Copper is believed to be an essential cofactor in the enzyme ammonia monooxygenase (AMO), which catalyzes the first essential step...... be supplied in a controlled fashion, and that little maintenance and no chemicals are required. Copper dosing through the novel electrolysis method, as well as through passive dosing from solid copper and active dosing of copper solution, was studied at nine more DWTPs, which all shared a long history...... were the main active ammonium oxidizers during the dosing. This PhD project revealed that copper is of vital importance for efficient nitrification in biological rapid sand filters for drinking water production. The results of this study have important practical implications for biofilters currently...

  14. Explaining low rates of sustained use of siphon water filter: evidence from follow-up of a randomised controlled trial in Bangladesh.

    Science.gov (United States)

    Najnin, Nusrat; Arman, Shaila; Abedin, Jaynal; Unicomb, Leanne; Levine, David I; Mahmud, Minhaj; Leder, Karin; Yeasmin, Farzana; Luoto, Jill E; Albert, Jeff; Luby, Stephen P

    2015-04-01

    To assess sustained siphon filter usage among a low-income population in Bangladesh and study relevant motivators and barriers. After a randomised control trial in Bangladesh during 2009, 191 households received a siphon water filter along with educational messages. Researchers revisited households after 3 and 6 months to assess filter usage and determine relevant motivators and barriers. Regular users were defined as those who reported using the filter most of the time and were observed to be using the filter at follow-up visits. Integrated behavioural model for water, sanitation and hygiene (IBM-WASH) was used to explain factors associated with regular filter use. Regular filter usage was 28% at the 3-month follow-up and 21% at the 6-month follow-up. Regular filter users had better quality water at the 6-month, but not at the 3-month visit. Positive predictors of regular filter usage explained through IBM-WASH at both times were willingness to pay >US$1 for filters, and positive attitude towards filter use (technology dimension at individual level); reporting boiling drinking water at baseline (psychosocial dimension at habitual level); and Bengali ethnicity (contextual dimension at individual level). Frequently reported barriers to regular filter use were as follows: considering filter use an additional task, filter breakage and time required for water filtering (technology dimension at individual level). The technological, psychosocial and contextual dimensions of IBM-WASH contributed to understanding the factors related to sustained use of siphon filter. Given the low regular usage rate and the hardware-related problems reported, the contribution of siphon filters to improving water quality in low-income urban communities in Bangladesh is likely to be minimal. © 2014 John Wiley & Sons Ltd.

  15. Density and distribution of nitrifying guilds in rapid sand filters for drinking water production: Dominance of Nitrospira spp

    DEFF Research Database (Denmark)

    Tatari, Karolina; Musovic, Sanin; Gülay, Arda

    2017-01-01

    distribution of these guilds, filter material was sampled at four drinking water treatment plants (DWTPs) in parallel filters of the pre- and after-filtration stages at different locations and depths. The target guilds were quantified by qPCR targeting 16S rRNA and amoA genes. Total bacterial densities......We investigated the density and distribution of total bacteria, canonical Ammonia Oxidizing Bacteria (AOB) (Nitrosomonas plus Nitrosospira), Ammonia Oxidizing Archaea (AOA), as well as Nitrobacter and Nitrospira in rapid sand filters used for groundwater treatment. To investigate the spatial...

  16. Characterization of water commercial filters based on activated carbon for water treatment of the Tumbes river – Peru

    Directory of Open Access Journals (Sweden)

    Carmen Rosa Silupú García

    2017-09-01

    Full Text Available Comercial activated carbon samples (A, B, C, and D used in filters for the treatment of water were characterized and evaluated in the decontamination of heavy metals present in river water and in the elimination of coliform microorganisms. The carbon samples had microporous and mesoporous structures. Surface areas of between 705 and 906 m2/g were found. The carbons samples were amorphous and the presence of antibacterial agents such as Ag, Cl, Cu, and Si was detected. It was determined that for As and Pb, whose initial concentrations in contaminated water (water of the Tumbes river-Peru were 56.7 and 224.0 μg/L, respectively, the percentage of adsorption was close to 100%. The relationship between point of zero charge pH of the activated carbons and pH of the river water during the experiments plays a determinant role in the adsorption of the analyzed elements. The antibacterial capacity was evaluated satisfactorily against the following strains of fecal gram negative bacteria: Escherichia coli (ATCC® 25922™, Salmonella typhimurium (ATCC® 14028™, and Shigella flexneri (ATCC® 12022™. This ability is based on the surface presence in the carbons of the mentioned antibacterial agents.

  17. Controlled laboratory experiments and modeling of vegetative filter strips with shallow water tables

    Science.gov (United States)

    Fox, Garey A.; Muñoz-Carpena, Rafael; Purvis, Rebecca A.

    2018-01-01

    Natural or planted vegetation at the edge of fields or adjacent to streams, also known as vegetative filter strips (VFS), are commonly used as an environmental mitigation practice for runoff pollution and agrochemical spray drift. The VFS position in lowlands near water bodies often implies the presence of a seasonal shallow water table (WT). In spite of its potential importance, there is limited experimental work that systematically studies the effect of shallow WTs on VFS efficacy. Previous research recently coupled a new physically based algorithm describing infiltration into soils bounded by a water table into the VFS numerical overland flow and transport model, VFSMOD, to simulate VFS dynamics under shallow WT conditions. In this study, we tested the performance of the model against laboratory mesoscale data under controlled conditions. A laboratory soil box (1.0 m wide, 2.0 m long, and 0.7 m deep) was used to simulate a VFS and quantify the influence of shallow WTs on runoff. Experiments included planted Bermuda grass on repacked silt loam and sandy loam soils. A series of experiments were performed including a free drainage case (no WT) and a static shallow water table (0.3-0.4 m below ground surface). For each soil type, this research first calibrated VFSMOD to the observed outflow hydrograph for the free drainage experiments to parameterize the soil hydraulic and vegetation parameters, and then evaluated the model based on outflow hydrographs for the shallow WT experiments. This research used several statistical metrics and a new approach based on hypothesis testing of the Nash-Sutcliffe model efficiency coefficient (NSE) to evaluate model performance. The new VFSMOD routines successfully simulated the outflow hydrographs under both free drainage and shallow WT conditions. Statistical metrics considered the model performance valid with greater than 99.5% probability across all scenarios. This research also simulated the shallow water table experiments with

  18. Gas-operated heat pump for monovalent space heating and tap water heating. A seizable contribution to carbon dioxide emission control; Gasbetriebene Waermepumpe zur monovalenten Raumbeheizung und Trinkwassererwaermung. Ein greifbarer Beitrag zur Reduktion der CO{sub 2}-Emissionen

    Energy Technology Data Exchange (ETDEWEB)

    Heikrodt, K.; Heckt, R. [Viessmann Werke GmbH und Co., Allendorf (Germany)

    1999-07-01

    The project had the objectives to develop a Vuilleumier heat pump for space heating and make an experimental study testing it as a heat generator for a heating system for one- and multi-family houses. Apart from monovalent operation, the following boundary conditions were defined: provision for connection to existing heating systems, even radiator heatings with 75 C/60 C, tap water heating, and air-source heat. Performance constant, manufacturing cost, freedom from maintenance, and service life were taken into consideration in the design, rating and construction of the unit. (orig.) [German] Ziel des Vorhabens war die Entwicklung einer Vuilleumier-Waermepumpe zur Raumbeheizung und deren experimentelle Untersuchung als Waermeerzeuger fuer ein Heizungssystem in Ein- und Mehrfamilienhaeusern. Als Rahmebedingungen wurden neben einer monovalenten Betriebsweise auch die moegliche Anbindung an bestehende Heizungssysteme, sogar Radiatorheizungen mit 75 C/60 C, Trinkwassererwaermung und Luft als Waermequelle festgelegt. Leistungszahl, Herstellkosten, Wartungsfreiheit und Lebensdauer wurden in Konzeption, Auslegung und Konstruktion beruecksichtigt. (orig.)

  19. Using Iron-Manganese Co-Oxide Filter Film to Remove Ammonium from Surface Water

    Directory of Open Access Journals (Sweden)

    Ruifeng Zhang

    2017-07-01

    Full Text Available An iron-manganese co-oxide filter film (MeOx has been proven to be a good catalyst for the chemical catalytic oxidation of ammonium in groundwater. Compared with groundwater, surface water is generally used more widely and has characteristics that make ammonium removal more difficult. In this study, MeOx was used to remove ammonium from surface water. It indicated that the average ammonium removal efficiency of MeOx was greater than 90%, even though the water quality changed dramatically and the water temperature was reduced to about 6–8 °C. Then, through inactivating microorganisms, it showed that the removal capability of MeOx included both biological (accounted for about 41.05% and chemical catalytic oxidation and chemical catalytic oxidation (accounted for about 58.95%. The investigation of the characterizations suggested that MeOx was formed by abiotic ways and the main elements on the surface of MeOx were distributed homogenously. The analysis of the catalytic oxidation process indicated that ammonia nitrogen may interact with MeOx as both ammonia molecules and ammonium ions and the active species of O2 were possibly •O and O2−.

  20. Cluster randomized controlled trial of the plastic BioSand Water filter in Cambodia.

    Science.gov (United States)

    Stauber, C E; Printy, E R; McCarty, F A; Liang, K R; Sobsey, M D

    2012-01-17

    About half of the rural population of Cambodia lacks access to improved water; an even higher percentage lacks access to latrines. More than 35,000 concrete BioSand Water filters (BSF) have been installed in the country. However, the concrete BSF takes time to produce and weighs hundreds of pounds. A plastic BSF has been developed but may not perform to the same benchmarks established by its predecessor. To evaluate plastic BSF performance and health impact, we performed a cluster randomized controlled trial in 13 communities including 189 households and 1147 participants in the Angk Snoul district of Kandal Province from May to December 2008. The results suggest that villages with plastic BSFs had significantly lower concentrations of E. coli in drinking water and lower diarrheal disease (incidence rate ratio 0.41, 95% confidence interval: 0.24-0.69) compared to control villages. As one of the first studies on the plastic BSF in Cambodia, these are important findings, especially in a setting where the concrete BSF has seen high rates of continued use years after installation. The study suggests the plastic BSF may play an important role in scaling up the distribution/implementation of the BSF, potentially improving water quality and health in the region.

  1. Point-of-use water purification using clay pot water filters and copper ...

    African Journals Online (AJOL)

    2011-11-24

    Nov 24, 2011 ... all pathogenic contaminants present in raw water. Many of the CPWFs reported in literature remove up to 98–99% of the disease-causing pathogens. It is therefore a common practice to incorporate an antibacterial agent such as colloidal silver into the structure of CPWFs as an additional measure to ensure.

  2. [Field study to obtain Legionella-free water from showers and sinks of a transplantation unit by a system of water filters].

    Science.gov (United States)

    Wendt, C; Weist, K; Dietz, E; Schlattmann, P; Rüden, H

    1995-03-01

    The efficiency of filters for elimination of Legionella was examined in a ten month field study. Showers and sinks of twelve patient rooms were equipped with nylon 66-polyamid filters. Before filtration the total number of colonies was very high with an arithmetical mean of 1131 cfu/ml. This could be reduced by filtration at the sinks (mean = 205 cfu/ml). After equipping showers with filters we found a significant increase in the total number of colonies (mean = 1961 cfu/ml). In non-filtered water we found Legionella in nearly 90% of the 648 samples, the concentration extended to 300 cfu/ml (mean = 51 cfu/ml). After filtration the concentration of Legionella was up to 280 cfu/ml in 7.3% of the 665 samples. We calculated a logistic regression model to examine the effects of the age of the filters and the duration of their use since the last sterilization. These parameters were calculated from the time of the break through or retrograde contamination with Legionella. There were clear differences between shower and sink filters. Assuming a 5% probability of break through or retrograde contamination with Legionella, the sink filters should be sterilized every 3 weeks without regards to the age of the filters. In contrast the shower filters may be used for 3 weeks if they are sterilized weekly. If weekly sterilization is not feasible they should be used for 2 weeks only. In our study it was not possible to achieve Legionella-free water by changing either the frequency of sterilization or the age of the filters.

  3. Characterization of filters cartridges from the water polishing system of IEA-R1 reactor: radiometric methods

    International Nuclear Information System (INIS)

    Tessaro, Ana Paula G.; Vicente, Roberto

    2015-01-01

    The acceptance of radioactive waste in a repository depends primarily on knowledge of the radioisotopic inventory of the material, according to regulations established by regulatory agencies. The primary characterization is also a fundamental action to determine further steps in the management of the radioactive wastes. The aim of this work is to report the development of non-destructive methods for primary characterization of filters cartridges discarded as radioactive waste. The filters cartridges are used in the water polishing system of the IEA-R1 reactor retaining the particles in suspension in the reactor cooling water. The IEA-R1 is a pool type reactor with a thermal power of 5 MW, moderated and cooled with light water. It is located in the Energy and Nuclear Research Institute (IPEN-CNEN), in São Paulo, Brazil. The cartridge filters become radioactive waste when they are saturated and do not meet the required flow for the proper operation of the water polishing system. The activities of gamma emitters present in the filters are determined using gamma spectrometry, dose rate measurements and the Point Kernel Method to correlate results from both measurements. For the primary characterization, one alternative method is the radiochemical analysis of slices taken from each filter, what presents the disadvantage of higher exposures personnel and contamination risks. Another alternative method is the calibration of the measurement geometry of a gamma spectrometer, which requires the production of a standard filter. Both methods are necessary but can not be used in operational routine of radioactive waste management owing to cost and complexity. The method described can be used to determine routinely the radioactive inventory of these filters and other radioactive wastes, avoiding the necessity of destructive radiochemical analysis, or the necessity of calibrating the geometry of measurement. (author)

  4. Tapping mode microwave impedance microscopy

    KAUST Repository

    Lai, K.

    2009-01-01

    We report tapping mode microwave impedance imaging based on atomic force microscope platforms. The shielded cantilever probe is critical to localize the tip-sample interaction near the tip apex. The modulated tip-sample impedance can be accurately simulated by the finite-element analysis and the result agrees quantitatively to the experimental data on a series of thin-film dielectric samples. The tapping mode microwave imaging is also superior to the contact mode in that the thermal drift in a long time scale is totally eliminated and an absolute measurement on the dielectric properties is possible. We demonstrated tapping images on working nanodevices, and the data are consistent with the transport results. © 2009 American Institute of Physics.

  5. Integrated programmable photonic filter on the silicon -on- insulator platform

    DEFF Research Database (Denmark)

    Liao, Shasha; Ding, Yunhong; Peucheret, Christophe

    2014-01-01

    We propose and demonstrate a silicon - on - insulator (SOI) on - chip programmable filter based on a four - tap finite impulse response structure. The photonic filter is programmable thanks to amplitude and phase modulation of each tap controlled by thermal heater s. We further demonstrate...

  6. Ensemble kalman filtering to perform data assimilation with soil water content probes and pedotransfer functions in modeling water flow in variably saturated soils

    Science.gov (United States)

    Data from modern soil water contents probes can be used for data assimilation in soil water flow modeling, i.e. continual correction of the flow model performance based on observations. The ensemble Kalman filter appears to be an appropriate method for that. The method requires estimates of the unce...

  7. "Bottled or Tap?" A Controversy for Science, Economics, and Society

    Science.gov (United States)

    Lapham, Steven S.

    2009-01-01

    Every year, Americans spend billions of dollars on bottled water. They purchase a bottle from the vending machine or buy a case at the grocery, no longer considering the water that's freely available from their taps. As consumers and as citizens, however, Americans should pause to study the personal and public consequences of this choice. In this…

  8. Rapid quantification of radiocesium dissolved in water by using nonwoven fabric cartridge filters impregnated with potassium zinc ferrocyanide

    International Nuclear Information System (INIS)

    Yasutaka, Tetsuo; Takahashi, Akira; Kawamoto, Tohru; Tsuji, Hideki; Kondo, Yoshihiko; Suzuki, Yasukazu

    2015-01-01

    This paper presents a cartridge filter incorporating a nonwoven fabric impregnated with potassium zinc ferrocyanide (Zn-C) to effectively concentrate and quantify cesium dissolved in water. Experiments conducted with 137 Cs in conditioned water showed that at a flow rate of 2.5 L/min the filter could absorb 97.9% of dissolved 137 Cs from 20 L of water; high recovery efficiency was achieved over a pH range of 3-10. Test measurements of 137 Cs concentrations using Zn-C in river water agreed with the results derived by using an evaporative concentration method (within the counting error of the detector). Using this method, the pre-concentration time of radiocesium in 20 L of fresh water can be reduced to just 8 minutes. (author)

  9. Use of self cleaning filters as pre-filter in water injection for maintenance of fine filters life; Uso de filtros auto limpantes como pre-filtro em agua de injecao para manutencao da vida util dos filtros polidores

    Energy Technology Data Exchange (ETDEWEB)

    Ramalhao, Adriano Gorga; Seno, Carlos Eduardo; Ribeiro, Alice [3M do Brasil Ltda., Sumare, SP (Brazil)

    2008-07-01

    The water injection treatment involves several units of treatment, which are defined and designed from data, some obtained from measurements, with other empirical formulas, others as a compromise, and that most of them varies. This variability can be covered by some filtration systems with greater flexibility. In the case of self cleaning filtration systems, they offer such flexibility due to its retro washing automated by metal cartridges that can extend up to fifty percent in the life of the filter end in cases of deterioration in water quality because of increased organic material for many reasons. (author)

  10. Application of design for six sigma methodology on portable water filter that uses membrane filtration system: A preliminary study

    Science.gov (United States)

    Fahrul Hassan, Mohd; Jusoh, Suhada; Zaini Yunos, Muhamad; Arifin, A. M. T.; Ismail, A. E.; Rasidi Ibrahim, M.; Zulafif Rahim, M.

    2017-09-01

    Portable water filter has grown significantly in recent years. The use of water bottles as a water drink stuff using hand pump water filtration unit has been suggested to replace water bottled during outdoor recreational activities and for emergency supplies. However, quality of water still the issue related to contaminated water due to the residual waste plants, bacteria, and so on. Based on these issues, the study was carried out to design a portable water filter that uses membrane filtration system by applying Design for Six Sigma. Design for Six Sigma methodology consists of five stages which is Define, Measure, Analyze, Design and Verify. There were several tools have been used in each stage in order to come out with a specific objective. In the Define stage, questionnaire approach was used to identify the needs of portable water filter in the future from potential users. Next, Quality Function Deployment (QFD) tool was used in the Measure stage to measure the users’ needs into engineering characteristics. Based on the information in the Measure stage, morphological chart and weighted decision matrix tools were used in the Analyze stage. This stage performed several activities including concept generation and selection. Once the selection of the final concept completed, detail drawing was made in the Design stage. Then, prototype was developed in the Verify stage to conduct proof-of-concept testing. The results that obtained from each stage have been reported in this paper. From this study, it can be concluded that the application of Design for Six Sigma in designing a future portable water filter that uses membrane filtration system is a good start in looking for a new alternative concept with a completed supporting document.

  11. Comparison of the efficiency of polycarbonate and mixed cellulose ester filters for use in the filtration of water samples

    Energy Technology Data Exchange (ETDEWEB)

    Brackett, K.A.; Clark, P.J.

    1993-01-01

    The federal standard for the presence of asbestos in drinking water mandates the use of transmission electron microscopy (TEM) as the only acceptable testing method. The July 17, 1992 Federal Register specifies that the analysis for asbestos shall be conducted by the EPA Protocol entitled Analytical Method for Determination of Asbestos Fibers in Water (EPA-600/4-83) developed by Chatfield and Dillon (1), using polycarbonate (PC) membrane filters. A separate document (1993) providing guidance and clarification of the Chatfield method has been peer reviewed, which allows some slight changes to what was originally a research method, but still requires the use of PC filters. A draft of an alternative method using mixed cellulose ester (MCE) membrane filters was recently published in The Microscope (2). The experiment was designed to determine the quantitative differences between the two methods for all fiber lengths as well as for the regulated fibers > or = 10 micrometers in length.

  12. Geothermal Energy: Tapping the Potential

    Science.gov (United States)

    Johnson, Bill

    2008-01-01

    Ground source geothermal energy enables one to tap into the earth's stored renewable energy for heating and cooling facilities. Proper application of ground-source geothermal technology can have a dramatic impact on the efficiency and financial performance of building energy utilization (30%+). At the same time, using this alternative energy…

  13. TAP: More than Performance Pay

    Science.gov (United States)

    Sawchuk, Stephen

    2009-01-01

    Since its inception, the program has tackled the most challenging issue facing the teaching profession: how to align systems for managing schools' human capital with goals for improving student achievement. In addition to pay, the Teacher Advancement Program (TAP) shapes new approaches to on-the-job training, career advancement, and evaluation in…

  14. Progressive Increase in Disinfection By-products and Mutagenicity from Source to Tap to Swimming Pool and Spa Water: Impact of Human Use

    Science.gov (United States)

    Pools and spas are enjoyed throughout the world for exercise and relaxation. However, there are no previous studies on mutagenicity of disinfected spa (hot tub) waters or comprehensive identification of disinfection byproducts (DBPs) formed in spas. Using 28 water samples from ...

  15. Laboratory Feasibility Evaluation of a New Modified Iron Product for Use as a Filter Material to Treat Agricultural Drainage Waters

    Science.gov (United States)

    Allred, B. J.

    2010-12-01

    The removal of excess soil water with a subsurface drainage pipe system is a common agricultural practice employed to improve crop yields, especially in the Midwest U.S. However, fertilizer nutrients (nitrate and phosphate) and pesticides applied on farm fields will frequently leach downwards through the soil profile to be intercepted by the buried drainage pipes and then discharged with drainage water into neighboring streams and lakes, oftentimes producing adverse environmental impacts on local, regional, and national scales. On-site drainage water filter treatment systems can potentially be employed to prevent the release of agricultural nutrients/pesticides into adjacent waterways. A recently developed modified iron product may have promise as a filter material used within this type of drainage water treatment system. Therefore, a laboratory study was initiated to directly evaluate the feasibility of employing this new modified iron product as a filter material to treat drainage waters. Laboratory research included saturated falling-head hydraulic conductivity tests, contaminant (nutrient/pesticide) removal batch tests, and saturated solute transport column experiments. The saturated falling-head hydraulic conductivity tests indicate that the unaltered modified iron product by itself has a high enough hydraulic conductivity (> 1.0 x 10-3 cm/s) to normally allow sufficient water flow rates that are needed to make this material hydraulically practical for use in drainage water filter treatment systems. Modified iron hydraulic conductivity can be improved substantially (> 1 x 10-2 cm/s) by using only the portion of this material that is retained on a 100 mesh sieve (particle size > 0.15 mm). Batch test results carried out with spiked drainage water and either unaltered or 100 mesh sieved modified iron showed nitrate reductions of greater than 30% and 100% removal of the pesticide, atrazine. Saturated solute transport columns tests with spiked drainage water

  16. Sphagnum can 'filter' N deposition, but effects on the plant and pore water depend on the N form.

    Science.gov (United States)

    Chiwa, Masaaki; Sheppard, Lucy J; Leith, Ian D; Leeson, Sarah R; Tang, Y Sim; Cape, J Neil

    2016-07-15

    The ability of Sphagnum moss to efficiently intercept atmospheric nitrogen (N) has been assumed to be vulnerable to increased N deposition. However, the proposed critical load (20kgNha(-1)yr(-1)) to exceed the capacity of the Sphagnum N filter has not been confirmed. A long-term (11years) and realistic N manipulation on Whim bog was used to study the N filter function of Sphagnum (Sphagnum capillifolium) in response to increased wet N deposition. On this ombrotrophic peatland where ambient deposition was 8kgNha(-1)yr(-1), an additional 8, 24, and 56kgNha(-1)yr(-1) of either ammonium (NH4(+)) or nitrate (NO3(-)) has been applied for 11years. Nutrient status of Sphagnum and pore water quality from the Sphagnum layer were assessed. The N filter function of Sphagnum was still active up to 32kgNha(-1)yr(-1) even after 11years. N saturation of Sphagnum and subsequent increases in dissolved inorganic N (DIN) concentration in pore water occurred only for 56kgNha(-1)yr(-1) of NH4(+) addition. These results indicate that the Sphagnum N filter is more resilient to wet N deposition than previously inferred. However, functionality will be more compromised when NH4(+) dominates wet deposition for high inputs (56kgNha(-1)yr(-1)). The N filter function in response to NO3(-) uptake increased the concentration of dissolved organic N (DON) and associated organic anions in pore water. NH4(+) uptake increased the concentration of base cations and hydrogen ions in pore water though ion exchange. The resilience of the Sphagnum N filter can explain the reported small magnitude of species change in the Whim bog ecosystem exposed to wet N deposition. However, changes in the leaching substances, arising from the assimilation of NO3(-) and NH4(+), may lead to species change. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. WATER CONDITIONING FOR FOOD INDUSTRY USES

    Directory of Open Access Journals (Sweden)

    RAISA NASTAS

    2011-03-01

    Full Text Available Water conditioning for food industry uses. Tap (drinkingwater from many localities of Moldova doesn’t always correspond to the “Sanitarystandards for drinking water quality” or to the requirements of the “Regulation fornon-alcoholic beverages”, requiring the need for additional purification/conditioning. This paper presents research regarding the removal/adsorption of themain pollutants in tap water (iron, manganese, aluminum, humic substances,trihalomethanes on supports of local carbon adsorbents made from vegetableproducts (stones of peach and plum, walnut shells. Experiments were performedin dynamic conditions in columns of carbon adsorbents. As work solutions wasused tap water where pollutants have been introduced in amounts equivalent to 3maximum allowable concentrations. Carbonaceous adsorbents used forremoval/adsorption of pollutants in dynamic conditions, reveal a capacity of up to1:400 volumes adsorbent: solution before breakthrough. Combined filter, utilizingactive carbons, was constructed and tested for conditioning of tap water forbeverage and food production. The results demonstrated efficient remove oforganic substances and heavy metals by filtering of about 700 volumes of waterper volume of filter.

  18. GPR image analysis to locate water leaks from buried pipes by applying variance filters

    Science.gov (United States)

    Ocaña-Levario, Silvia J.; Carreño-Alvarado, Elizabeth P.; Ayala-Cabrera, David; Izquierdo, Joaquín

    2018-05-01

    Nowadays, there is growing interest in controlling and reducing the amount of water lost through leakage in water supply systems (WSSs). Leakage is, in fact, one of the biggest problems faced by the managers of these utilities. This work addresses the problem of leakage in WSSs by using GPR (Ground Penetrating Radar) as a non-destructive method. The main objective is to identify and extract features from GPR images such as leaks and components in a controlled laboratory condition by a methodology based on second order statistical parameters and, using the obtained features, to create 3D models that allows quick visualization of components and leaks in WSSs from GPR image analysis and subsequent interpretation. This methodology has been used before in other fields and provided promising results. The results obtained with the proposed methodology are presented, analyzed, interpreted and compared with the results obtained by using a well-established multi-agent based methodology. These results show that the variance filter is capable of highlighting the characteristics of components and anomalies, in an intuitive manner, which can be identified by non-highly qualified personnel, using the 3D models we develop. This research intends to pave the way towards future intelligent detection systems that enable the automatic detection of leaks in WSSs.

  19. Optimization of an enhanced ceramic micro-filter for concentrating E.coli in water

    Science.gov (United States)

    Zhang, Yushan; Guo, Tianyi; Xu, Changqing; Hong, Lingcheng

    2017-02-01

    Recently lower limit of detection (LOD) is necessary for rapid bacteria detection and analysis applications in clinical practices and daily life. A critical pre-conditioning step for these applications is bacterial concentration, especially for low level of pathogens. Sample volume can be largely reduced with an efficient pre-concentration process. Some approaches such as hollow-fiber ultra-filtration and electrokinetic technique have been applied to bacterial concentration. Since none of these methods can provide a concentrating method with a stable recovery efficiency, bacterial concentration still remains challenging Ceramic micro- filter can be used to concentrate the bacteria but the cross flow system keeps the bacteria in suspension. Similar harvesting bacteria using ultra-filtration showed an average recovery efficiency of 43% [1] and other studies achieved recovery rates greater than 50% [2]. In this study, an enhanced ceramic micro-filter with 0.14 μm pore size was proposed and demonstrated to optimize the concentration of E.coli. A high recovery rate (mean value >90%) and a high volumetric concentration ratio (>100) were achieved. Known quantities (104 to 106 CFU/ml) of E.coli cells were spiked to different amounts of phosphate buffered saline (0.1 to 1 L), and then concentrated to a final retentate of 5 ml to 10 ml. An average recovery efficiency of 95.3% with a standard deviation of 5.6% was achieved when the volumetric con- centration ratio was 10. No significant recovery rate loss was indicated when the volumetric concentration ratio reached up to 100. The effects of multiple parameters on E.coli recovery rate were also studied. The obtained results indicated that the optimized ceramic micro- filtration system can successfully concentrate E.coli cells in water with an average recovery rate of 90.8%.

  20. Manganese oxidation and bacterial diversity on different filter media coatings during the start-up of drinking water biofilters

    DEFF Research Database (Denmark)

    Breda, I. L.; Ramsay, L.; Roslev, P.

    2017-01-01

    Manganese removal is a typical concern in drinking water production. Biofiltration may be used when treating groundwater sources but the onset of manganese removal in virgin biofilters can vary considerably. The aim of this study was to investigate the effect of different filter media on manganese...

  1. Polaromonas and Hydrogenophaga species are the predominant bacteria cultured from granular activated carbon filters in water treatment

    NARCIS (Netherlands)

    Magic-Knezev, A.; Wullings, B.A.; Kooij, van der D.

    2009-01-01

    AIM: Identification of the predominating cultivable bacteria in granular activated carbon (GAC) filters used in a variety of water treatment plants for selecting representative strains to study the role of bacteria in the removal of dissolved organic matter. METHODS AND RESULTS: Bacterial isolates

  2. Synthetic ultraviolet light filtering chemical contamination of coastal waters of Virgin Islands National Park, St. John, U.S. Virgin Islands

    Science.gov (United States)

    Bargar, Timothy A.; Alvarez, David; Garrison, Virginia H.

    2015-01-01

    Contamination of surface waters by synthetic ultraviolet light (UV) filtering chemicals is a concern for the Virgin Islands National Park (VINP). Discrete water samples were collected from VINP bays to determine UV filter chemical presence in the coastal waters. Spatial distribution and the potential for partitioning between subsurface waters and the sea surface microlayer (SML) were also examined. The UV filter chemicals 4-methylbenzylidene camphor, benzophenone-3, octinoxate, homosalate, and octocrylene were detected at concentrations up to 6073 ng/L (benzophenone-3). Concentrations for benzophenone-3 and homosalate declined exponentially (r2 = 0.86 to 0.98) with distance from the beach. Limited data indicate that some UV filter chemicals may partition to the SML relative to the subsurface waters. Contamination of VINP coastal waters by UV filter chemicals may be a significant issue, but an improved understanding of the temporal and spatial variability of their concentrations would be necessary to better understand the risk they present.

  3. Retention of titanium dioxide nanoparticles in biological activated carbon filters for drinking water and the impact on ammonia reduction.

    Science.gov (United States)

    Liu, Zhiyuan; Yu, Shuili; Park, Heedeung; Liu, Guicai; Yuan, Qingbin

    2016-06-01

    Given the increasing discoveries related to the eco-toxicity of titanium dioxide (TiO2) nanoparticles (NPs) in different ecosystems and with respect to public health, it is important to understand their potential effects in drinking water treatment (DWT). The effects of TiO2 NPs on ammonia reduction, ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in biological activated carbon (BAC) filters for drinking water were investigated in static and dynamic states. In the static state, both the nitrification potential and AOB were significantly inhibited by 100 μg L(-1) TiO2 NPs after 12 h (p  0.05). In the dynamic state, different amounts of TiO2 NP pulses were injected into three pilot-scale BAC filters. The decay of TiO2 NPs in the BAC filters was very slow. Both titanium quantification and scanning electron microscope analysis confirmed the retention of TiO2 NPs in the BAC filters after 134 days of operation. Furthermore, the TiO2 NP pulses considerably reduced the performance of ammonia reduction. This study identified the retention of TiO2 NPs in BAC filters and the negative effect on the ammonia reduction, suggesting a potential threat to DWT by TiO2 NPs.

  4. Benzophenone-type UV filters in surface waters: An assessment of profiles and ecological risks in Shanghai, China.

    Science.gov (United States)

    Wu, Ming-Hong; Xie, Deng-Guo; Xu, Gang; Sun, Rui; Xia, Xiao-Yu; Liu, Wen-Long; Tang, Liang

    2017-07-01

    Benzophenone-type UV filters (BP-UV filters) are frequently introduced into aquatic environment from several sources. The occurrence and fate of select BP-UV filters and their metabolites were investigated in this study. All target compounds were detected in water samples, except for 2, 3, 4-trihydroxybenzophenone (2, 3, 4-OH-BP). The concentration reached up 131ngL -1 for 5-benzoyl-4-hydroxy-2-ethoxybenzenesulfonic acid (BP-4), 30.0ngL -1 for 2-hydroxy-4-methoxybenzophenone (BP-3), and mean value of 158ngL -1 for benzophenone (BP). Concentrations of BP-UV filters were not related to recreational waters but with high population frequencies. In addition, five BP-UV filters, namely 2,2',4,4'-tetrahydroxybenzophenone (BP-2), 2,3,4-OH-BP, 2,4-dihydroxybenzophenone (BP-1), 4-hydroxybenzophenone (4-OH-BP) and BP were investigated for probable sources, and found that they originate from BP-3 metabolism. There is a similar source for BP-3, BP-4, BP-1, 4-OH-BP and BP. Environmental risk assessment (ERA) showed that risk quotients (RQs) of BP-4, BP-3 and BP were 2.7, 0.8 and 0.5, respectively. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Technical Note: Improved total atmospheric water vapour amount determination from near-infrared filter measurements with sun photometers

    Directory of Open Access Journals (Sweden)

    F. Mavromatakis

    2007-09-01

    Full Text Available In this work we explore the effect of the contribution of the solar spectrum to the recorded signal in wavelengths outside the typical 940-nm filter's bandwidth. We employ gaussian-shaped filters as well as actual filter transmission curves, mainly AERONET data, to study the implications imposed by the non-zero out-of-band contribution to the coefficients used to derive precipitable water from the measured water vapour band transmittance. Published parameterized transmittance functions are applied to the data to determine the filter coefficients. We also introduce an improved, three-parameter, fitting function that can describe the theoretical data accurately, with significantly less residual effects than with the existing functions. The moderate-resolution SMARTS radiative transfer code is used to predict the incident spectrum outside the filter bandpass for different atmospheres, solar geometries and aerosol optical depths. The high-resolution LBLRTM radiative transfer code is used to calculate the water vapour transmittance in the 940-nm band. The absolute level of the out-of-band transmittance has been chosen to range from 10−6 to 10−4, and typical response curves of commercially available silicon photodiodes are included into the calculations.

    It is shown that if the out-of-band transmittance effect is neglected, as is generally the case, then the derived columnar water vapour is mainly underestimated by a few percents. The actual error depends on the specific out-of-band transmittance, optical air mass of observation and water vapour amount. Further investigations will use experimental data from field campaigns to validate these findings.

  6. 3D soil water nowcasting using electromagnetic conductivity imaging and the ensemble Kalman filter

    Science.gov (United States)

    Huang, Jingyi; McBratney, Alex B.; Minasny, Budiman; Triantafilis, John

    2017-06-01

    Mapping and immediate forecasting of soil water content (θ) and its movement can be challenging. Although inversion of apparent electrical conductivity (ECa) measured by electromagnetic induction to calculate depth-specific electrical conductivity (σ) has been used, it is difficult to apply it across a field. In this paper we use a calibration established along a transect, across a 3.94-ha field with varying soil texture, using an ensemble Kalman filter (EnKF) to monitor and nowcast the 3-dimensional θ dynamics on 16 separate days over a period of 38 days. The EnKF combined a physical model fitted with θ measured by soil moisture sensors and an Artificial Neural Network model comprising σ generated by quasi-3d inversions of DUALEM-421S ECa data. Results showed that the distribution of θ was controlled by soil texture, topography, and vegetation. Soil water dried fastest at the beginning after the initial irrigation event and decreased with time and soil depth, which was consistent with classical soil drying theory and experiments. It was also found that the soil dried fastest in the loamy and duplex soils present in the field, which was attributable to deep drainage and preferential flow. It was concluded that the EnKF approach can be used to improve the irrigation efficiency by applying variable irrigation rates across the field. In addition, soil water status can be nowcasted across large spatial extents using this method with weather forecast information, which will provide guidance to farmers for real-time irrigation management.

  7. Subproductos halogenados de la cloración en el agua de consumo público Halogenated by-products of chlorination in tap water

    Directory of Open Access Journals (Sweden)

    J. Calderón

    2002-06-01

    Full Text Available Objetivo: La presencia de trihalometanos en el agua de diversas ciudades españolas está demostrada. Este estudio pretende analizar sus concentraciones en el agua de la ciudad de Barcelona. Métodos: Se analizan 151 muestras de agua recogidas durante el año 1998. Los análisis se realizaron en el laboratorio municipal mediante purge and trap y posterior determinación por cromatografía de gases acoplada a espectrofotometría de masas. Los resultados se presentan según el origen del agua: ríos Llobregat, Ter o mezcla. Resultados: En aguas del Ter los valores son relativamente bajos y predominan cloroformo y bromodiclorometano, mientras que en las del Llobregat son más elevados y predominan bromoformo y dibromoclorometano. Las aguas de mezcla presentan valores intermedios. Los valores totales alcanzados en las muestras procedentes del Llobregat superan los 100 µg/l. Conclusiones: Estos resultados muestran la necesidad de seguir corrigiendo la contaminación orgánica y los compuestos halogenados en el agua captada para el consumo humano en Barcelona.Objective: The presence of trihalomethanes in the water systems of several Spanish cities has been demonstrated. The aim of this study was to analyze trihalomethane concentrations in the water provided for human consumption in the city of Barcelona. Methods: We analyzed 151 water samples collected in 1998. The analyses were performed in the Public Health Laboratory of Barcelona using the purge-and-trap method and subsequent determination by gas chromatography and mass spectrometry. The results are presented according to the source of the water: the rivers of Llobregat or Ter, or a mixture of these. Results: Thrihalomethane concentrations in the water from Ter were relatively low, with a predominance of chloroform and bromodichloromethane, while concentrations in the water from Llobregat were much higher, with a predominance of bromoform and dibromochloromethane. Mixed water showed intermediate

  8. A New Method for the Fast Analysis of Trihalomethanes in Tap and Recycled Waters Using Headspace Gas Chromatography with Micro-Electron Capture Detection

    Directory of Open Access Journals (Sweden)

    Lydon D. Alexandrou

    2017-05-01

    Full Text Available Chemical disinfection of water supplies brings significant public health benefits by reducing microbial contamination. The process can however, result in the formation of toxic compounds through interactions between disinfectants and organic material in the source water. These new compounds are termed disinfection by-products (DBPs. The most common are the trihalomethanes (THMs such as trichloromethane (chloroform, dichlorobromomethane, chlorodibromomethane and tribromomethane (bromoform; these are commonly reported as a single value for total trihalomethanes (TTHMs. Analysis of DBPs is commonly performed via time- and solvent-intensive sample preparation techniques such as liquid–liquid and solid phase extraction. In this study, a method using headspace gas chromatography with micro-electron capture detection was developed and applied for the analysis of THMs in drinking and recycled waters from across Melbourne (Victoria, Australia. The method allowed almost complete removal of the sample preparation step whilst maintaining trace level detection limits (>1 ppb. All drinking water samples had TTHM concentrations below the Australian regulatory limit of 250 µg/L but some were above the U.S. EPA limit of 60 µg/L. The highest TTHM concentration was 67.2 µg/L and lowest 22.9 µg/L. For recycled water, samples taken directly from treatment plants held significantly higher concentrations (153.2 µg/L TTHM compared to samples from final use locations (4.9–9.3 µg/L.

  9. Assessment of polycarbonate filter in a molecular analytical system for the microbiological quality monitoring of recycled waters onboard ISS.

    Science.gov (United States)

    Bechy-Loizeau, Anne-Laure; Flandrois, Jean-Pierre; Abaibou, Hafid

    2015-07-01

    On the ISS, as on Earth, water is an essential element for life and its quality control on a regular basis allows to ensure the health of the crew and the integrity of equipment. Currently, microbial water analysis onboard ISS still relies on the traditional culture-based microbiology methods. Molecular methods based on the amplification of nucleic acids for microbiological analysis of water quality show enormous potential and are considered as the best alternative to culture-based methods. For this reason, the Midass, a fully integrated and automated prototype was designed conjointly by ESA and bioMérieux for a rapid monitoring of the microbiological quality of air. The prototype allows air sampling, sample processing and the amplification/detection of nucleic acids. We describe herein the proof of principle of an analytical approach based on molecular biology that could fulfill the ESA's need for a rapid monitoring of the microbiological quality of recycled water onboard ISS. Both concentration and recovery of microorganisms are the main critical steps when the microfiltration technology is used for water analysis. Among filters recommended standards for monitoring the microbiological quality of the water, the polycarbonate filter was fully in line with the requirements of the ISO 7704-1985 standard in terms of efficacy of capture and recovery of bacteria. Moreover, this filter does not retain nucleic acids on the surface and has no inhibitory effect on their downstream processing steps such as purification and amplification/detection. Although the Midass system was designed for the treatment of air samples, the first results on the integration of PC filters were encouraging. Nevertheless, system modifications are needed to better adapt the Midass system for the monitoring of the microbiological water quality. Copyright © 2015 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

  10. The Nano-filters as the tools for the management of the water imbalance in the human society

    Science.gov (United States)

    Singh, R. P.; Kontar, V.

    2011-12-01

    ultra-thin nanoscale fibers, which filter out contaminants, plus active carbon granules, which kill bacteria. The carbon nano-tube as filters exhibit chemical-species selectivity with higher physical strength and higher temperature tolerance, more rugged process, more rapid filtration, regeneration via thermal means rather than physical removal and lowers costs. The nano-filters remove the toxic or unwanted bivalent ions (ions with 2 or more charges), such as lead, iron, nickel, mercury, etc. The nano-materials and nano-filters will help solve the problems of the water imbalance management in the human society. Therefore we are talking about some nano-applications on the session H138 "Imbalance of Water in Nature".

  11. Tapping Site Planning and Design

    Science.gov (United States)

    2010-06-17

    US Army Corps of Engineers BUILDING STRONG® Tapping Site Planning and Design Kevin S. Holden, RLA, ASLA Landscape Architecture Community of Practice...PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) US Army Corps of Engineers,Community of Practice Leader for Landscape ,Rock Island,IL,61204-2004 8...STRONG® Site Planning and Design 1. How is Site Planning and Design foundational to sustainable development? 2. What role does the Landscape Architect

  12. Strong low-pass filtering effects on water vapour flux measurements with closed-path eddy correlation systems

    DEFF Research Database (Denmark)

    Ibrom, Andreas; Dellwik, Ebba; Flyvbjerg, Henrik K.

    2007-01-01

    forest in Soro, Zealand, Denmark, amounted on average to 42% of the measured flux, while it was only 4% for the CO2 flux, which was measured with the same EC system. We recommend using the described method to correct water vapour fluxes measured in any closed-path EC system for unintended low......Turbulent water vapour fluxes measured with closed-path eddy correlation (EC) systems are unintentionally low-pass filtered by the system in a manner that varies with environmental conditions. Why and how is described here. So is the practical method that systematically corrects long-term flux...... datasets for this substantial measurement error. In contrast to earlier studies, a large number of spectra and raw data have been used in the analysis to define the low-pass filtering characteristic of the EC system. This revealed that the cut-off frequency of the closed-path EC system for water vapour...

  13. Density and distribution of nitrifying guilds in rapid sand filters for drinking water production: Dominance of Nitrospira spp.

    Science.gov (United States)

    Tatari, Karolina; Musovic, Sanin; Gülay, Arda; Dechesne, Arnaud; Albrechtsen, Hans-Jørgen; Smets, Barth F

    2017-12-15

    We investigated the density and distribution of total bacteria, canonical Ammonia Oxidizing Bacteria (AOB) (Nitrosomonas plus Nitrosospira), Ammonia Oxidizing Archaea (AOA), as well as Nitrobacter and Nitrospira in rapid sand filters used for groundwater treatment. To investigate the spatial distribution of these guilds, filter material was sampled at four drinking water treatment plants (DWTPs) in parallel filters of the pre- and after-filtration stages at different locations and depths. The target guilds were quantified by qPCR targeting 16S rRNA and amoA genes. Total bacterial densities (ignoring 16S rRNA gene copy number variation) were high and ranged from 10 9 to 10 10 per gram (10 15 to 10 16 per m 3 ) of filter material. All examined guilds, except AOA, were stratified at only one of the four DWTPs. Densities varied spatially within filter (intra-filter variation) at two of the DWTPs and in parallel filters (inter-filter variation) at one of the DWTPs. Variation analysis revealed random sampling as the most efficient strategy to yield accurate mean density estimates, with collection of at least 7 samples suggested to obtain an acceptable (below half order of magnitude) density precision. Nitrospira was consistently the most dominant guild (5-10% of total community), and was generally up to 4 orders of magnitude more abundant than Nitrobacter and up to 2 orders of magnitude more abundant than canonical AOBs. These results, supplemented with further analysis of the previously reported diversity of Nitrospira in the studied DWTPs based on 16S rRNA and nxrB gene phylogeny (Gülay et al., 2016; Palomo et al., 2016), indicate that the high Nitrospira abundance is due to their comammox (complete ammonia oxidation) physiology. AOA densities were lower than AOB densities, except in the highly stratified filters, where they were of similar abundance. In conclusion, rapid sand filters are microbially dense, with varying degrees of spatial heterogeneity, which

  14. Laboratory Evaluation of Sulfur Modified Iron for Use as a Filter Material to Treat Agricultural Drainage Waters

    Science.gov (United States)

    Allred, B. J.

    2009-12-01

    Where subsurface drainage practices are employed, fertilizer nutrients and pesticides applied on farm fields and municipal locations are commonly intercepted by the buried drainage pipes and then discharged into local streams and lakes, oftentimes producing adverse environmental impacts on these surface water bodies. On-site water filter treatment systems can be employed to prevent the release of agricultural nutrients/pesticides into adjacent waterways. Sulfur modified iron is a relatively unknown industrial product that may have promise for use as a filter material to remove contaminants from subsurface drainage waters. Sulfur modified iron (SMI) is a high surface area iron powder (zero valent iron) that has been altered via chemical reaction with pure sulfur to produce a sulfur/iron surface coating on the iron particles. A laboratory investigation was conducted with contaminant removal batch tests, saturated falling-head hydraulic conductivity tests, and saturated solute transport column experiments to evaluate the feasibility for using SMI to treat subsurface drainage waters. Contaminant removal batch tests showed that three SMI samples were much more effective removing nitrate (> 94% nitrate removed) than three zero valent iron samples (pesticide, atrazine (< 37% atrazine removed). Hydraulic conductivity tests indicated that all three SMI samples that were evaluated had sufficient hydraulic conductivity, much greater than the 1 x 10-3 cm/s standard used for stormwater sand filters. The saturated solute transport tests confirmed that SMI can be effective removing nitrate and phosphate from drainage waters. Analysis of column effluent also showed that the large majority of nitrate removed by SMI was converted to ammonium. Consequently, these laboratory findings support the use of SMI in agricultural drainage water filter treatment systems, particularly when nitrate and phosphate pollution are major environmental concerns.

  15. Concentration of enteroviruses, adenoviruses, and noroviruses from drinking water by use of glass wool filters.

    Science.gov (United States)

    Lambertini, Elisabetta; Spencer, Susan K; Bertz, Phillip D; Loge, Frank J; Kieke, Burney A; Borchardt, Mark A

    2008-05-01

    Available filtration methods to concentrate waterborne viruses are either too costly for studies requiring large numbers of samples, limited to small sample volumes, or not very portable for routine field applications. Sodocalcic glass wool filtration is a cost-effective and easy-to-use method to retain viruses, but its efficiency and reliability are not adequately understood. This study evaluated glass wool filter performance to concentrate the four viruses on the U.S. Environmental Protection Agency contaminant candidate list, i.e., coxsackievirus, echovirus, norovirus, and adenovirus, as well as poliovirus. Total virus numbers recovered were measured by quantitative reverse transcription-PCR (qRT-PCR); infectious polioviruses were quantified by integrated cell culture (ICC)-qRT-PCR. Recovery efficiencies averaged 70% for poliovirus, 14% for coxsackievirus B5, 19% for echovirus 18, 21% for adenovirus 41, and 29% for norovirus. Virus strain and water matrix affected recovery, with significant interaction between the two variables. Optimal recovery was obtained at pH 6.5. No evidence was found that water volume, filtration rate, and number of viruses seeded influenced recovery. The method was successful in detecting indigenous viruses in municipal wells in Wisconsin. Long-term continuous filtration retained viruses sufficiently for their detection for up to 16 days after seeding for qRT-PCR and up to 30 days for ICC-qRT-PCR. Glass wool filtration is suitable for large-volume samples (1,000 liters) collected at high filtration rates (4 liters min(-1)), and its low cost makes it advantageous for studies requiring large numbers of samples.

  16. Modeling water and sediment trapping by vegetated filters using vfsmod: comparing methods for estimating infiltration parameters

    Science.gov (United States)

    Amanda L. Fox; Dean E. Eisenhauer; Michael G. Dosskey

    2005-01-01

    Vegetated filters (buffers) are used to intercept overland runoff and reduce sediment and other contaminant loads to streams (Dosskey, 2001). Filters function by reducing runoff velocity and volume, thus enhancing sedimentation and infiltration. lnfiltration is the main mechanism for soluble contaminant removal, but it also plays a role in suspended particle removal....

  17. Analysis of pharmaceutical and other organic wastewater compounds in filtered and unfiltered water samples by gas chromatography/mass spectrometry

    Science.gov (United States)

    Zaugg, Steven D.; Phillips, Patrick J.; Smith, Steven G.

    2014-01-01

    Research on the effects of exposure of stream biota to complex mixtures of pharmaceuticals and other organic compounds associated with wastewater requires the development of additional analytical capabilities for these compounds in water samples. Two gas chromatography/mass spectrometry (GC/MS) analytical methods used at the U.S. Geological Survey National Water Quality Laboratory (NWQL) to analyze organic compounds associated with wastewater were adapted to include additional pharmaceutical and other organic compounds beginning in 2009. This report includes a description of method performance for 42 additional compounds for the filtered-water method (hereafter referred to as the filtered method) and 46 additional compounds for the unfiltered-water method (hereafter referred to as the unfiltered method). The method performance for the filtered method described in this report has been published for seven of these compounds; however, the addition of several other compounds to the filtered method and the addition of the compounds to the unfiltered method resulted in the need to document method performance for both of the modified methods. Most of these added compounds are pharmaceuticals or pharmaceutical degradates, although two nonpharmaceutical compounds are included in each method. The main pharmaceutical compound classes added to the two modified methods include muscle relaxants, opiates, analgesics, and sedatives. These types of compounds were added to the original filtered and unfiltered methods largely in response to the tentative identification of a wide range of pharmaceutical and other organic compounds in samples collected from wastewater-treatment plants. Filtered water samples are extracted by vacuum through disposable solid-phase cartridges that contain modified polystyrene-divinylbenzene resin. Unfiltered samples are extracted by using continuous liquid-liquid extraction with dichloromethane. The compounds of interest for filtered and unfiltered sample

  18. Occurrence, distribution and ecological risk assessment of multiple classes of UV filters in surface waters from different countries.

    Science.gov (United States)

    Tsui, Mirabelle M P; Leung, H W; Wai, Tak-Cheung; Yamashita, Nobuyoshi; Taniyasu, Sachi; Liu, Wenhua; Lam, Paul K S; Murphy, Margaret B

    2014-12-15

    Organic UV filters are common ingredients of personal care products (PCPs), but little is known about their distribution in and potential impacts to the marine environment. This study reports the occurrence and risk assessment of twelve widely used organic UV filters in surface water collected in eight cities in four countries (China, the United States, Japan, and Thailand) and the North American Arctic. The number of compounds detected, Hong Kong (12), Tokyo (9), Bangkok (9), New York (8), Los Angeles (8), Arctic (6), Shantou (5) and Chaozhou (5), generally increased with population density. Median concentrations of all detectable UV filters were UV filter levels in Hong Kong. In general, spatial patterns varied with sampling month and all compounds showed higher concentrations in the wet season except benzophenone-4 (BP-4). Probabilistic risk assessment showed that 4-methylbenzylidene camphor (4-MBC) posed greater risk to algae, while benzophenone-3 (BP-3) and ethylhexyl methoxycinnamate (EHMC) were more likely to pose a risk to fishes and also posed high risk of bleaching in hard corals in aquatic recreational areas in Hong Kong. This study is the first to report the occurrence of organic UV filters in the Arctic and provides a wider assessment of their potential negative impacts in the marine environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Tapping into community resources in China | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2011-01-18

    Jan 18, 2011 ... The time saved as result of the tap water system enabled farmers to establish a fruit orchard on uncultivated lands — sloping hills that can't be used for farming without risking soil erosion. Villagers also developed an approach for reforesting and managing disappearing forest lands. From 1995 to 1997, ...

  20. Economic benefits flow from taps | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-12-08

    Dec 8, 2010 ... Community-run tap water systems in China's remote Guizhou province have enabled families to develop new income-generating activities and boost a faltering economy. The advances arose from an IDRC-sponsored project in the late 1990s promoting “community-based natural resource management.

  1. Bilateral transversus abdominis plane (TAP) block with 24 hours ropivacaine infusion via TAP catheters

    DEFF Research Database (Denmark)

    Petersen, Pernille L; Hilsted, Karen L; Dahl, Jørgen B

    2013-01-01

    The analgesic effect of a TAP block has been investigated in various surgical settings. There are however limited information about block level and block duration. Furthermore, there is a lack of information about continuous TAP block after ultrasound-guided posterior TAP blocks.The aim of this d...... of this double-blind randomized study was therefore to investigate the effect of an ultrasound-guided posterior TAP block with 24 hours local anesthetic infusion via a TAP catheter....

  2. Radium desorption, manganese and iron dissolution from sand filters of a conventional ground water treatment plant under reductive conditions

    International Nuclear Information System (INIS)

    Al-Hobaib, A.S.; Al-Sulaiman, K.M.; Al-Dhayan, D.M.; Al-Suhybani, A.A.

    2006-01-01

    Sand filters are used as a filter bed in many ground water treatment plants to remove the physical contaminants and oxidation products. A build-up of radioactivity may take place on the granules, where iron and manganese oxides are deposited and form thin films on the surface of sand filter. The oxides of iron and manganese play an important role in adsorbing radium from ground water. The disposal of those granules makes a significant problem. A batch technique is used for solubilization of radium from sand filters in the presence of some organic acids, which act as reducing agents. These acids are formic acid, acetic acid, benzoic acid, succinic acid, oxalic acid, phthalic acid, and adipic acid. The data were obtained as a function of acidity, temperature, contact time and liquid/solid ratio particle size and shaking speed. It was found that oxalic acid was the best for radium removal. The effectiveness of these acids on radium removal was as follows: oxalic acid > phthalic acid > adipic acid > succinic acid > formic acid > acetic acid. The maximum removal obtained was 69.9% at 1M oxalic acid at 8 ml/g ratio. Reaction kinetics and mechanism parameters of the dissolution process were studied and compared with other published data. (author)

  3. Operation and performance evaluation of high-speed filter using porous non-woven filamentous fibre for the treatment of turbid water.

    Science.gov (United States)

    Niu, Siping; Park, Kisoo; Yu, Jianghua; Kim, Youngchul

    2016-01-01

    This study was carried out to identify the filter performance of fibre filter module treating high-turbidity water at extremely high filtration rates (1000-2500 m/day). The effects of filter aid chemical (polyaluminium chloride (PAC)), filtration rate and particles size on filter performance were investigated. It was found that PAC was a crucial factor influencing the separation process. Even though the optimum PAC dose for the raw water with turbidity of 50 nephelometric turbidity units (NTU) was 0.5 mg/L, the turbidity removal efficiencies were similar as the raw water turbidity was no more than 50 NTU. As expected, the filter performance was negatively affected by the increased filtration rate. However, the turbidity removal efficiency at an extremely high filtration rate still was amazing and attractive (∼80% at 2500 m/day). Moreover, the D50 and uniformity coefficient of the particles in raw water were not the factors greatly affecting the filter performance. The empirical model for the filter processes of granular filters did not work; therefore, an empirical model towards fibre filters at a high flow rate was suggested, which can be used to predict the treatment performance.

  4. Water

    OpenAIRE

    Hertie School of Governance

    2010-01-01

    All human life depends on water and air. The sustainable management of both is a major challenge for today's public policy makers. This issue of Schlossplatz³ taps the streams and flows of the current debate on the right water governance.

  5. Comparison of k Q factors measured with a water calorimeter in flattening filter free (FFF) and conventional flattening filter (cFF) photon beams

    Science.gov (United States)

    de Prez, Leon; de Pooter, Jacco; Jansen, Bartel; Perik, Thijs; Wittkämper, Frits

    2018-02-01

    Recently flattening filter free (FFF) beams became available for application in modern radiotherapy. There are several advantages of FFF beams over conventional flattening filtered (cFF) beams, however differences in beam spectra at the point of interest in a phantom potentially affect the ion chamber response. Beams are also non-uniform over the length of a typical reference ion chamber and recombination is usually larger. Despite several studies describing FFF beam characteristics, only a limited number of studies investigated their effect on k Q factors. Some of those studies predicted significant discrepancies in k Q factors (0.4% up to 1.0%) if TPR20,10 based codes of practice (CoPs) were to be used. This study addresses the question to which extent k Q factors, based on a TPR20,10 CoP, can be applied in clinical reference dosimetry. It is the first study that compares k Q factors measured directly with an absorbed dose to water primary standard in FFF-cFF pairs of clinical photon beams. This was done with a transportable water calorimeter described elsewhere. The measurements corrected for recombination and beam radial non-uniformity were performed in FFF-cFF beam pairs at 6 MV and 10 MV of an Elekta Versa HD for a selection of three different Farmer-type ion chambers (eight serial numbers). The ratio of measured k Q factors of the FFF-cFF beam pairs were compared with the TPR20,10 CoPs of the NCS and IAEA and the %dd(10) x CoP of the AAPM. For the TPR20,10 based CoPs differences less than 0.23% were found in k Q factors between the corresponding FFF-cFF beams with standard uncertainties smaller than 0.35%, while for the %dd(10) x these differences were smaller than 0.46% and within the expanded uncertainty of the measurements. Based on the measurements made with the equipment described in this study the authors conclude that the k Q factors provided by the NCS-18 and IAEA TRS-398 codes of practice can be applied for flattening filter free beams without

  6. Pollution patterns and underlying relationships of benzophenone-type UV-filters in wastewater treatment plants and their receiving surface water.

    Science.gov (United States)

    Wu, Ming-Hong; Li, Jian; Xu, Gang; Ma, Luo-Dan; Li, Jia-Jun; Li, Jin-Song; Tang, Liang

    2018-05-15

    The environmental behaviors of emerging pollutants, benzophenone-type UV filters (BP-UV filters) and their derivatives were investigated in four wastewater treatment plants (WWTPs), and their receiving surface waters in Shanghai. The concentration level of selected BP-UV filters in the WWTPs was detected from ngL -1 to μgL -1 . BP (621-951ngL -1 ) and BP-3 (841-1.32 × 10 3 ngL -1 ) were the most abundant and highest detection frequency individuals among the target BP-UV filters in influents, whereas BP (198-400ngL -1 ), BP-4 (93.3-288ngL -1 ) and BP-3 (146-258ngL -1 ) were predominant in effluents. BP-UV filters cannot be completely removed and the total removal efficiency varied widely (-456% to 100%) during the treatment process. It can be inferred that the usage of BP and BP-3 are higher than other BP-UV filters in the study area. The lowest and highest levels were BP-2 (ND-7.66ngL -1 ) and BP-3 (68.5-5.01 × 10 3 ng L -1 ) in the receiving surface water, respectively. Interestingly, the seasonal variation of BP-3 is larger than those of other BP-UV filters in surface water from Shanghai. There is no obvious pollution pattern of BP-UV filters in the surface water from the cosmetic factory area. The correlation analysis of BP-UV filters between WWTPs effluents and nearby downstream water samples suggested that BP-UV filters emitted from some WWTPs might be the main source of receiving surface water. Preliminary risk assessment indicated that the levels of BP-UV filters detected by the effluent posed medium to high risk to fish as well as other aquatic organisms. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Arsenic in drinking water wells on the Bolivian high plain: field monitoring and effect of salinity on removal efficiency of iron-oxides-containing filters

    OpenAIRE

    Van den Bergh, Kenneth; Du Laing, Gijs; Montoya, Juan; De Deckere, E; Tack, Filip

    2010-01-01

    In the rural areas around Oruro (Bolivia), untreated groundwater is used directly as drinking water. This research aimed to evaluate the general drinking water quality, with focus on arsenic (As) concentrations, based on analysis of 67 samples from about 16 communities of the Oruro district. Subsequently a filter using Iron Oxide Coated Sand (IOCS) and a filter using a Composite Iron Matrix (CIM) were tested for their arsenic removal capacity using synthetic water mimicking real groundwater. ...

  8. Multiplication of Legionella pneumophila Sequence Types 1, 47, and 62 in Buffered Yeast Extract Broth and Biofilms Exposed to Flowing Tap Water at Temperatures of 38°C to 42°C.

    Science.gov (United States)

    van der Kooij, Dick; Brouwer-Hanzens, Anke J; Veenendaal, Harm R; Wullings, Bart A

    2016-11-15

    Legionella pneumophila proliferates in freshwater environments at temperatures ranging from 25 to 45°C. To investigate the preference of different sequence types (ST) for a specific temperature range, growth of L. pneumophila serogroup 1 (SG1) ST1 (environmental strains), ST47, and ST62 (disease-associated strains) was measured in buffered yeast extract broth (BYEB) and biofilms grown on plasticized polyvinyl chloride in flowing heated drinking water originating from a groundwater supply. The optimum growth temperatures in BYEB were approximately 37°C (ST1), 39°C (ST47), and 41°C (ST62), with maximum growth temperatures of 42°C (ST1) and 43°C (ST47 and ST62). In the biofilm at 38°C, the ST47 and ST62 strains multiplied equally well compared to growth of the environmental ST1 strain and an indigenous L. pneumophila non-SG1 strain, all attaining a concentration of approximately 10 7 CFU/cm -2 Raising the temperature to 41°C did not impact these levels within 4 weeks, but the colony counts of all strains tested declined (at a specific decline rate of 0.14 to 0.41 day -1 ) when the temperature was raised to 42°C. At this temperature, the concentration of Vermamoeba vermiformis in the biofilm, determined with quantitative PCR (qPCR), was about 2 log units lower than the concentration at 38°C. In columns operated at a constant temperature, ranging from 38 to 41°C, none of the tested strains multiplied in the biofilm at 41°C, in which also V. vermiformis was not detected. These observations suggest that strains of ST47 and ST62 did not multiply in the biofilm at a temperature of ≥41°C because of the absence of a thermotolerant host. Growth of Legionella pneumophila in tap water installations is a serious public health concern. The organism includes more than 2,100 varieties (sequence types). More than 50% of the reported cases of Legionnaires' disease are caused by a few sequence types which are very rarely detected in the environment. Strains of selected

  9. Transdermal penetration of topically applied fluorescent dyes with and without the influence of Water Filtered Infrared-A-Radiation

    OpenAIRE

    Grone, Diego

    2010-01-01

    Optical methods were used to investigate the influence of water filtered infrared A radiation (wIRA) on the dermatopharmacokinetics of topically applied substances. The penetration profiles of the hydrophilic dye fluoresceine and the lipophilic dye curcumin in a standard o/w emulsion were determined by tape stripping, in combination with spectroscopic measurements. Additionally, the penetration was investigated in vivo by laser scanning microscopy. Three different protocols (mode A-C) were us...

  10. The occurrence of UV filters in natural and drinking water in São Paulo State (Brazil).

    Science.gov (United States)

    da Silva, Claudia Pereira; Emídio, Elissandro Soares; de Marchi, Mary Rosa Rodrigues

    2015-12-01

    Ultraviolet (UV) filters are widely used in the formulation of personal care products (PCPs) to prevent damage to the skin, lips, and hair caused by excessive UV radiation. Therefore, large amounts of these substances are released daily into the aquatic environment through either recreational activities or the release of domestic sewage. The concern regarding the presence of such substances in the environment and the exposure of aquatic organisms is based on their potential for bioaccumulation and their potential as endocrine disruptors. Although there are several reports regarding the occurrence and fate of UV filters in the aquatic environment, these compounds are still overlooked in tropical areas. In this study, we investigated the occurrence of the organic UV filters benzophenone-3 (BP-3), ethylhexyl salicylate (ES), ethylhexyl methoxycinnamate (EHMC), and octocrylene (OC) in six water treatment plants in various cities in Southeast Brazil over a period of 6 months to 1 year. All of the UV filters studied were detected at some time during the sampling period; however, only EHMC and BP-3 were found in quantifiable concentrations, ranging from 55 to 101 and 18 to 115 ng L(-1), respectively. Seasonal variation of BP-3 was most clearly noticed in the water treatment plant in Araraquara, São Paulo, where sampling was performed for 12 months. BP-3 was not quantifiable in winter but was quantifiable in summer. The levels of BP-3 were in the same range in raw, treated and chlorinated water, indicating that the compound was not removed by the water treatment process.

  11. Microbial degradation of pesticides in rapid sand filters used for drinking water treatment

    DEFF Research Database (Denmark)

    Hedegaard, Mathilde Jørgensen

    in rapid sand filters was not associated with methane oxidation. Based on the present investigations and literature, it was suggested that phenoxy acid degradation in rapid sand filters is due to primary metabolism, and that degradation might be stimulated by enriching naturally occurring specific...... degraders in the sand filters upon exposure to phenoxy acid contaminated groundwater. A suite of evidence showed that the herbicide bentazone was co-metabolically transformed to hydroxy-bentazone by the methanotrophic enrichment culture. Subsequently, it was investigated whether bentazone degradation...... a sequential reactor system, where methanotrophs are grown in the aeration tanks and transported to the rapid sand filters where they can perform co-metabolic pesticide biodegradation. It was suggested that bentazone removal can be stimulated at waterworks, by stimulating growth of methanotrophs. Overall...

  12. Impact of titanium dioxide nanoparticles on the bacterial communities of biological activated carbon filter intended for drinking water treatment.

    Science.gov (United States)

    Zhiyuan, Liu; Shuili, Yu; Heedeung, Park; Qingbin, Yuan; Guicai, Liu; Qi, Li

    2016-08-01

    Titanium dioxide nanoparticles (TiO2 NPs) are inevitably present in the aquatic environment owing to their increasing production and use. However, knowledge of the potential effects of TiO2 NPs on the treatment of drinking water is scarce. Herein, the effects of two types of anatase TiO2 NPs (TP1, 25 nm; TP2, 100 nm) on the bacterial community in a biological activated carbon (BAC) filter were investigated via quantitative polymerase chain reaction (Q-PCR) analysis, ATP quantification, and 454 pyrosequencing analysis. Both TP1 and TP2 significantly inhibited the bacterial ATP level (p treatment, whereas those of Bacilli class and Gammaproteobacteria class increased. TiO2 NP size showed a greater effect on the bacterial composition than did the dose based on Bray-Curtis distances. These findings identified negative effects of TiO2 NPs on the bacterial community in the BAC filter. Given the fact that BAC filters are used widely in drinking water treatment plants, these results suggested a potential threat by TiO2 NP to drinking water treatment system.

  13. Superhydrophilic and underwater superoleophobic poly(sulfobetaine methacrylate)-grafted glass fiber filters for oil-water separation.

    Science.gov (United States)

    Liu, Qingsheng; Patel, Ankit A; Liu, Lingyun

    2014-06-25

    Oil-water separation is a major problem in industries such as oil production and wastewater treatment, where millions of gallons of oil-contaminated water are produced. Zwitterionic poly(sulfobetaine methacrylate) (pSBMA) is a superhydrophilic polymer due to its strong interaction with water via electrostatic interactions. By coating surfaces of filter media with such a superhydrophilic polymer, it is expected that one can effectively separate oil and water. In this work, pSBMA was grafted onto glass fiber surfaces using surface-initiated atom transfer radical polymerization (SI-ATRP). The in-air water contact angle of the pSBMA-treated glass was 8-15°, as compared to 31° for the control untreated glass, whereas the underwater-oil contact angle of the pSBMA-grafted glass was 162-169°, as compared to 142° for the control pristine glass, suggesting that the pSBMA-grafted glass slides are superhydrophilic and underwater superoleophobic. Such superhydrophilicity and underwater superoleophobicity were realized by modifying surface chemistry only, with no need to create rough surfaces. The pSBMA-grafted glass fiber filters demonstrated exceptional results at separating oil from water without even allowing miniscule amounts of visible oil to permeate through.

  14. The distribution and tapping tidal energy

    Directory of Open Access Journals (Sweden)

    Zygmunt Kowalik

    2004-09-01

    Full Text Available Tidal power along tidal shores has been used for centuries to run small tidal mills. Generating electricity by tapping tidal power proved to be very successful only in the last century through the tidal power plant constructed in 1967 in La Rance, France. This used a large barrier to generate the sea level head necessary for driving turbines. Construction of such plants evolved very slowly because of prohibitive costs and concerns about the environmental impact. Developments in the construction of small, efficient and inexpensive underwater turbines admit the possibility of small scale operations that will use local tidal currents to bring electricity to remote locations. Since the generation of such electricity is concerned with the tidal energy in local water bodies, it is important to understand the site-specific energy balance, i.e., the energy flowing in through open boundaries, and the energy generated and dissipated within the local domain. The question is how to tap the tidal energy while keeping possible changes in the present tidal regimes to a minimum. The older approach of constructing barrages may still be quite useful in some locations. The basics of such tidal power plants constructed in a small bay are analyzed in order to understand the principal parameter for tidal plant evaluation, i.e., the power produced.     The new approach is to place turbines - devices similar to windmills - in the pathway of tidal currents. Theoretically, the amount of power available by such turbines for electricity generation is proportional to the water density and velocity cubed of the tidal flow. The naturally dissipated tidal power due to bottom friction forces is also proportional to the cube of the velocity. Because of this similarity, the exploitation of tidal energy can be directed to reinvesting the naturally dissipated power into tidal power for the generation of electricity. This approach to tidal power exploitation is better tuned

  15. Environmental occurrence and ecological risk assessment of organic UV filters in marine organisms from Hong Kong coastal waters.

    Science.gov (United States)

    Sang, Ziye; Leung, Kelvin Sze-Yin

    2016-10-01

    Organic UV filters, now considered to be emerging contaminants in aquatic ecosystems, are being intensively tracked in environmental waters worldwide. However, their environmental fate and impact of these contaminants on marine organisms remains largely unknown, especially in Asia. This work elucidates the occurrence and the ecological risks of seven UV filters detected in farmed fish, wild mussels and some other wild organisms collected from local mariculture farms in Hong Kong. For all of the organisms, ethylhexyl methoxycinnamate (EHMC) and octyl dimethyl p-aminobenzoic acid (OD-PABA) were the predominant contaminants with the highest concentrations up to 51.3 and 24.1ng/g (dw), respectively; lower levels were found for benzophenone-8 (BP-8), octocrylene (OC) and benzophenone-3 (BP-3) from UV filters indicated a positive correlation between their measured concentrations and the anthropogenic activities responsible for their direct emission. The ecological risk assessment specific to the marine aquatic environment was carried out. The risk quotient (RQ) values of EHMC and BP-3 were calculated as 3.29 and 2.60, respectively, indicating these two UV filters may pose significant risks to the marine aquatic environment. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Occurrence of pharmaceuticals and UV-filters in riverine run-offs and waters of the German Baltic Sea.

    Science.gov (United States)

    Fisch, Kathrin; Waniek, Joanna J; Schulz-Bull, Detlef E

    2017-11-15

    The occurrence of pharmaceuticals and personal care products (PPCPs) in the marine environment is of great concern. This study was done to determine the emergence of eight pharmaceuticals and eleven ultraviolet filters (UV-Filters) in 5 rivers/streams discharging into the Baltic Sea. Furthermore, a focus was put on the influence of wastewater treatment plant as indirect source and the occurrence of the PPCPs in close beach proximity. Two pharmaceuticals (sulfamethoxazole, salicylic acid) and two UV-filters (2-phenylbenzimidazole-5-sulfonic acid, octocrylene) were detected in all analyzed water samples, with concentration ranging from 0.6ng/L to 836.3ng/L. In all rivers the PPCP concentration decreases towards the Baltic Sea. Sulfamethoxazole was detected at comparable concentration along the coast, which leads to the assumption of stable concentration in beach proximity. Along the coast UV-filters appeared in varying concentrations, leading to the conclusion that the direct input into the marine environment plays a bigger role than the indirect input. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Improved platelet compatibility of water vapour glow discharge treated non-woven poly(ethylene therephthalate) leukocyte-reduction filters of different types of platelet concentrates

    NARCIS (Netherlands)

    Kostelijk, E.H.; Klomp, A.J.A.; Klomp, A.J.A.; Engbers, G.H.M.; Gouwerok, C.W.N.; van Aken, W.G.; Verhoeven, A.J.; Feijen, Jan; de Korte, D.

    2001-01-01

    Non-woven poly[ethylene terephthalate] (NW-PET) filter fabric, usually used for leucocyte removal of red cells, was modified by water vapour glow discharge (WVGD) treatment to improve platelet compatibility. Modified filter material was evaluated with different kinds of platelet concentrates (PCs).

  18. Improved platelet compatiblity of water vapour glow discharge treated non-woven poly(ethylene terephthalate) leukocyte-reduction filters for different types of platelet concentrates

    NARCIS (Netherlands)

    Kostelijk, E. H.; Klomp, A. J.; Engbers, G. H.; Gouwerok, C. W.; Verhoeven, A. J.; van Aken, W. G.; Feijen, J.; de Korte, D.

    2001-01-01

    Non-woven poly[ethylene terephthalate] (NW-PET) filter fabric, usually used for leucocyte removal of red cells, was modified by water vapour glow discharge (WVGD) treatment to improve platelet compatibility. Modified filter material was evaluated with different kinds of platelet concentrates (PCs).

  19. Manganese dioxide-coated filters for removing radium from drinking water. Report for 19 September 1983-1 September 1987

    International Nuclear Information System (INIS)

    Menetrez, M.Y.; Anderson, D.G.; Stahel, E.P.

    1988-09-01

    Research was performed using manganese dioxide (MnO 2 ) to demonstrate that above pH3 cations are adsorbed from solution in the order of their affinity, and that the interaction is characterized by the pH dependence of the metal. The relationship of the zero-point charge of pH and the solution ionic strength effects on interfacial surface potential and adsorption were addressed. Characteristics of MnO 2 behavior, structure, and stability found in research investigation were reviewed. Most of the study was on the use of MnO 2 coated filters for the removal of radium. A few comparison tests on radium removal with ion exchange were also made. Specifically, these tests have shown that acrylic-fiber filters coated with MnO 2 will remove radium from water. For a high-hardness water with pH = 7.4, total radium removal was 14,200 pCi/g MnO 2 before the MCL of 5 pCi/L was exceeded, and for a low-hardness water with pH = 4.5, total radium removal was 5000 pCi/g MnO 2 before the MCL of 5 pCi/L was exceeded. Hardness passed through the MnO 2 filters with little change and, therefore, radium was highly preferred over hardness. A step-by-step process for the preparation of acrylic-fiber filters coated with MnO 2 was designed and operated successfully

  20. Downregulation of TAP1 and TAP2 in early stage breast cancer.

    Directory of Open Access Journals (Sweden)

    Andrea M Henle

    Full Text Available TAP1-TAP2 heterodimeric complexes are recognized as the transporter associated with antigen processing of major histocompatibility complex class I peptides for recognition by tumor-specific cytotoxic T lymphocytes. In this study, we investigated the immunohistochemical expression of TAP1 and TAP2 in 160 patients with breast cancer and correlated their expression levels with clinicopathologic parameters. The median age of the patient cohort was 52.5 years (range, 30-86 years. Both TAP1 and TAP2 immunohistochemical expression levels correlated significantly with breast cancer characteristics (P < .001. TAP1 expression levels were low to negative in stage I breast tumors. TAP1 and TAP2 levels were significantly higher in grade 3 tumors than low-grade (grade 1 and 2 tumors. TAP1 and TAP2 expression levels were not significantly different among different levels of HER2-expressing tumors and did not vary by estrogen and progesterone receptor status or patient age. Both TAP1 and TAP2 overexpression in breast cancer might be an indicator of an aggressive breast tumor.

  1. Feasibility of snow water equivalent estimation using the Ensemble Kalman Filter

    Science.gov (United States)

    Durand, M. T.; Margulis, S. A.

    2004-12-01

    Recent studies have demonstrated the tremendous affect of snow cover on the dynamics of land surface behavior. Due to the large latent heat of vaporziation of water and the high albedo of snow, snow cover plays a key role in the global energy balance. Additionally, it is well-known that many arid regions depend upon the seasonal snowpack as a main source of water. These facts have driven the study of snow and the interest in increasingly sophisticated snow characterization within land surface models (LSMs). The large uncertainty associated with the LSMs and with precipitation data in general is one reason why work is being done to constrain the models with observations of snow states and remote sensing observations. The latter have a tremendous potential for improving model performance due to the relative ease of collection when compared with in-situ observations. Attempts have been made to obtain snow water equivalent (SWE) estimates by inverting remote sensing observations. Such methods include empirical regression algorithms based upon results from radiative transfer models (RTMs), `direct insertion' methods for incorporating retrieved snow state estimates directly into an LSM, and neural network-based schemes which adjust snow states until predictions from an RTM match the remote sensing observation. While each of these methods have had some success, the robust estimation of SWE and other snow properties is made difficult by the complex dependence of the remotely sensed signal on a number of snowpack characteristics. Data assimilation is an ideal framework for merging multi-frequency remote sensing observations and a snow physics model, because it provides a means of weighing the tremendous uncertainty of meteorological data (such as precipitation measurements from snow gages) and remote sensing observations. The objective of this study is to assess the feasibility of using the Ensemble Kalman Filter (EnKF) to characterize snowpack properties. The EnKF follows

  2. Behavioral Reactivity Associated With Electronic Monitoring of Environmental Health Interventions--A Cluster Randomized Trial with Water Filters and Cookstoves.

    Science.gov (United States)

    Thomas, Evan A; Tellez-Sanchez, Sarita; Wick, Carson; Kirby, Miles; Zambrano, Laura; Abadie Rosa, Ghislaine; Clasen, Thomas F; Nagel, Corey

    2016-04-05

    Subject reactivity--when research participants change their behavior in response to being observed--has been documented showing the effect of human observers. Electronics sensors are increasingly used to monitor environmental health interventions, but the effect of sensors on behavior has not been assessed. We conducted a cluster randomized controlled trial in Rwanda among 170 households (70 blinded to the presence of the sensor, 100 open) testing whether awareness of an electronic monitor would result in a difference in weekly use of household water filters and improved cookstoves over a four-week surveillance period. A 63% increase in number of uses of the water filter per week between the groups was observed in week 1, an average of 4.4 times in the open group and 2.83 times in the blind group, declining in week 4 to an insignificant 55% difference of 2.82 uses in the open, and 1.93 in the blind. There were no significant differences in the number of stove uses per week between the two groups. For both filters and stoves, use decreased in both groups over four-week installation periods. This study suggests behavioral monitoring should attempt to account for reactivity to awareness of electronic monitors that persists for weeks or more.

  3. Ammonium removal pathways and microbial community in GAC-sand dual media filter in drinking water treatment.

    Science.gov (United States)

    Feng, Shuo; Xie, Shuguang; Zhang, Xiaojian; Yang, Zhiyu; Ding, Wei; Liao, Xiaobin; Liu, Yuanyuan; Chen, Chao

    2012-01-01

    A GAC-sand dual media filter (GSF) was devised as an alternative solution for drinking water treatment plant to tackle the raw water polluted by ammonium in place of expensive ozone-GAC processes or bio-pretreatments. The ammonium removal pathways and microbial community in the GSFs were investigated. The concentrations of ammonium, nitrite and nitrate nitrogen were monitored along the filter. Total inorganic nitrogen (TIN) loss occurred during the filtration. For 1 mg ammonium removal, the TIN loss was as high as 0.35 mg, DO consumption was 3.06 mg, and alkalinity consumption was 5.55 mg. It was assumed that both nitrification and denitrification processes occur in the filters to fit the TIN loss and low DO consumption. During the filtration, nitritation, nitrification and nitritation-anaerobic ammonium oxidation processes probably occur, while traditional nitrification and denitrification and simultaneous nitrification and denitrification processes may occur. In the GSFs, Nitrosomonas and Nitrospira are likely to be involved in nitrification processes, while Novosphingobium, Comamonadaceae and Oxalobacteraceae may be involved in denitrification processes.

  4. Designing Programme Implementation Strategies to Increase the Adoption and Use of Biosand Water Filters in Rural India

    Directory of Open Access Journals (Sweden)

    Tommy K.K. Ngai

    2014-06-01

    Full Text Available Low-cost household water treatment systems are innovations designed to improve the quality of drinking water at the point of use. This study investigates how an NGO can design appropriate programme strategies in order to increase the adoption and sustained use of household sand filters in rural India. A system dynamics computer model was developed and used to assess 18 potential programme strategies for their effectiveness in increasing filter use at two and ten years into the future, under seven scenarios of how the external context may plausibly evolve. The results showed that the optimal choice of strategy is influenced by the macroeconomic situation, donor funding, presence of alternative options, and the evaluation time frame. The analysis also revealed some key programme management challenges, including the trade-off between optimising short- or long-term gains, and counter-intuitive results, such as higher subsidy fund allocation leading to fewer filter distribution, and technology advances leading to fewer sales. This study outlines how an NGO can choose effective strategies in consideration of complex system interactions. This study demonstrated that small NGOs can dramatically increase their programme outcomes without necessarily increasing operational budget.

  5. Peatlands as Filters for Polluted Mine Water?—A Case Study from an Uranium-Contaminated Karst System in South Africa—Part III: Quantifying the Hydraulic Filter Component

    Directory of Open Access Journals (Sweden)

    Frank Winde

    2011-03-01

    Full Text Available As Part III of a four-part series on the filter function of peat for uranium (U, this paper focuses on the hydraulic component of a conceptual filter model introduced in Part II. This includes the quantification of water flow through the wetland as a whole, which was largely unknown and found to be significantly higher that anticipated. Apart from subaquatic artesian springs associated with the underlying karst aquifer the higher flow volumes were also caused by plumes of polluted groundwater moving laterally into the wetland. Real-time, quasi-continuous in situ measurements of porewater in peat and non-peat sediments indicate that rising stream levels (e.g., during flood conditions lead to the infiltration of stream water into adjacent peat deposits and thus allow for a certain proportion of flood water to be filtered. However, changes in porewater quality triggered by spring rains may promote the remobilization of possibly sorbed U.

  6. The construction and initial startup of an onfloated pulver resin filter equipment for condensate treatment at a boiling water reactor

    International Nuclear Information System (INIS)

    Gruenewale, D.; Wieland, G.

    1978-01-01

    The treatment of condensate at the boiling water reactors is owing to the corrosive and splitting products, as well as condenser leakages obligatory. The various possibilities of condensate treatment flow diagrams are outlined. Then the procedure of the pulver resin onfloating and the functioning phases of the respective equipment are shown by the means of illustration materials. After the startup of the equipment the condensate make-up equipment presented a statisfactory function within a short time. After putting the power plant into service the condensate make-up equipment delivered an adequately clean condenste. The clefts arising under certain operational circumstances caused a weaker quality at the onfloating, but they could be eliminated in a short time. The comparison of costs with the mix-bed filters points out to the advantages of the onfloated filters until 500 l/h condenser leakage. (author)

  7. Vertical flow soil filter for the elimination of micro pollutants from storm and waste water

    DEFF Research Database (Denmark)

    Janzen, Niklas; Banzhaf, Stefan; Scheytt, Traugott

    2009-01-01

    ) to prevent clogging and was spiked with activated sludge to enhance microbial biomass and biodegradation potential. Compounds used as UV filters, antioxidants or plasticizers, namely 4-methylbenzylidene camphor (4-MBC), benzophenone-3 (BP-3), butylated hydroxytoluene (BHT), N-butylbenzenesulfonamide (NBBS...

  8. A standard test for filter media cleanliness | Van Staden | Water SA

    African Journals Online (AJOL)

    After a series of tests on various filter media, using 6 stripping methods, 2 methods were identified that met the criteria in the first objective. The first, a magnetic stirrer method is a mechanical agitation method and the second, referred to as the cylinder inversion method, is a manual agitation method. Each of these methods ...

  9. Recommendations for Evaluating Multiple Filters in Ballast Water Management Systems for US Type Approval

    Science.gov (United States)

    2016-01-01

    Escherichia coli,  cfu of intestinal enterococci, and ə cfu of toxigenic Vibrio cholerae). To meet these stringent discharge standards, most...Four standard methods have been developed to evaluate particle removal efficiency in air filters: (1) Weight arrestance test, (2) Atmospheric dust

  10. Process evaluation and assessment of use of a large scale water filter and cookstove program in Rwanda

    Directory of Open Access Journals (Sweden)

    Christina K. Barstow

    2016-07-01

    Full Text Available Abstract Background In an effort to reduce the disease burden in rural Rwanda, decrease poverty associated with expenditures for fuel, and minimize the environmental impact on forests and greenhouse gases from inefficient combustion of biomass, the Rwanda Ministry of Health (MOH partnered with DelAgua Health (DelAgua, a private social enterprise, to distribute and promote the use of improved cookstoves and advanced water filters to the poorest quarter of households (Ubudehe 1 and 2 nationally, beginning in Western Province under a program branded Tubeho Neza (“Live Well”. The project is privately financed and earns revenue from carbon credits under the United Nations Clean Development Mechanism. Methods During a 3-month period in late 2014, over 470,000 people living in over 101,000 households were provided free water filters and cookstoves. Following the distribution, community health workers visited nearly 98 % of households to perform household level education and training activities. Over 87 % of households were visited again within 6 months with a basic survey conducted. Detailed adoption surveys were conducted among a sample of households, 1000 in the first round, 187 in the second. Results Approximately a year after distribution, reported water filter use was above 90 % (+/−4 % CI and water present in filter was observed in over 76 % (+/−6 % CI of households, while the reported primary stove was nearly 90 % (+/−4.4 % CI and of households cooking at the time of the visit, over 83 % (+/−5.3 % CI were on the improved stove. There was no observed association between household size and stove stacking behavior. Conclusions This program suggests that free distribution is not a determinant of low adoption. It is plausible that continued engagement in households, enabled by Ministry of Health support and carbon financed revenue, contributed to high adoption rates. Overall, the program was able to demonstrate a privately

  11. TAP 3: Training Program Support Manual

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

    The Training Accreditation Program (TAP) establishes objectives and criteria against which DOE nuclear facility training is evaluated to determine readiness for accreditation. TAP 3 has been developed to assist the contractor in preparing the initial Self-Evaluation Report, Training Program Accreditation Plan, and the CSER (contractor self-evaluation report).

  12. Nanofiber Filters Eliminate Contaminants

    Science.gov (United States)

    2009-01-01

    With support from Phase I and II SBIR funding from Johnson Space Center, Argonide Corporation of Sanford, Florida tested and developed its proprietary nanofiber water filter media. Capable of removing more than 99.99 percent of dangerous particles like bacteria, viruses, and parasites, the media was incorporated into the company's commercial NanoCeram water filter, an inductee into the Space Foundation's Space Technology Hall of Fame. In addition to its drinking water filters, Argonide now produces large-scale nanofiber filters used as part of the reverse osmosis process for industrial water purification.

  13. Water-filtered infrared-A (wIRA can act as a penetration enhancer for topically applied substances

    Directory of Open Access Journals (Sweden)

    Sterry, Wolfram

    2008-07-01

    Full Text Available Background: Water-filtered infrared-A (wIRA irradiation has been shown to enhance penetration of clinically used topically applied substances in humans through investigation of functional effects of penetrated substances like vasoconstriction by cortisone. Aim of the study: Investigation of the influence of wIRA irradiation on the dermatopharmacokinetics of topically applied substances by use of optical methods, especially to localize penetrating substances, in a prospective randomised controlled study in humans. Methods: The penetration profiles of the hydrophilic dye fluorescein and the lipophilic dye curcumin in separate standard water-in-oil emulsions were determined on the inner forearm of test persons by tape stripping in combination with spectroscopic measurements. Additionally, the penetration was investigated in vivo by laser scanning microscopy. Transepidermal water loss, hydration of the epidermis, and surface temperature were determined. Three different procedures (modes A, B, C were used in a randomised order on three separate days of investigation in each of 12 test persons. In mode A, the two dyes were applied on different skin areas without water-filtered infrared-A (wIRA irradiation. In mode B, the skin surface was irradiated with wIRA over 30 min before application of the two dyes (Hydrosun® radiator type 501, 10 mm water cuvette, orange filter OG590, water-filtered spectrum: 590–1400 nm with dominant amount of wIRA. In mode C, the two dyes were applied and immediately afterwards the skin was irradiated with wIRA over 30 min. In all modes, tape stripping started 30 min after application of the formulations. Main variable of interest was the ratio of the amount of the dye in the deeper (second 10% of the stratum corneum to the amount of the dye in the upper 10% of the stratum corneum. Results: The penetration profiles of the hydrophilic fluorescein showed in case of pretreatment or treatment with wIRA (modes B and C an

  14. Fe-Ti/Fe (II)-loading on ceramic filter materials for residual chlorine removal from drinking water.

    Science.gov (United States)

    Man, Kexin; Zhu, Qi; Guo, Zheng; Xing, Zipeng

    2018-06-01

    Ceramic filter material was prepared with silicon dioxide (SiO 2 ), which was recovered from red mud and then modified with Fe (II) and Fe-Ti bimetal oxide. Ceramic filter material can be used to reduce the content of residual chlorine from drinking water. The results showed that after a two-step leaching process with 3 M hydrochloric acid (HCl) and 90% sulfuric acid (H 2 SO 4 ), the recovery of SiO 2 exceeded 80%. Fe (II)/Fe-Ti bimetal oxide, with a high adsorption capacity of residual chlorine, was prepared using a 3:1 M ratio of Fe/Ti and a concentration of 0.4 mol/L Fe 2+ . According to the zeta-potential, scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis, Fe (II) and Fe-Ti bimetal oxide altered the zeta potential and structural properties of the ceramic filter material. There was a synergistic interaction between Fe and Ti in which FeOTi bonds on the material surface and hydroxyl groups provided the active sites for adsorption. Through a redox reaction, Fe (II) transfers hypochlorite to chloride, and FeOTiCl bonds were formed after adsorption. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Characterization of the water filters cartridges from the iea-r1 reactor using the Monte Carlo method

    International Nuclear Information System (INIS)

    Costa, Priscila; Potiens Junior, Ademar J.

    2015-01-01

    Filter cartridges are part of the primary water treatment system of the IEA-R1 Research Reactor and, when saturated, they are replaced and become radioactive waste. The IEA-R1 is located at the Nuclear and Energy Research Institute (IPEN), in Sao Paulo, Brazil. The primary characterization is the main step of the radioactive waste management in which the physical, chemical and radiological properties are determined. It is a very important step because the information obtained in this moment enables the choice of the appropriate management process and the definition of final disposal options. In this paper, it is presented a non-destructive method for primary characterization, using the Monte Carlo method associated with the gamma spectrometry. Gamma spectrometry allows the identification of radionuclides and their activity values. The detection efficiency is an important parameter, which is related to the photon energy, detector geometry and the matrix of the sample to be analyzed. Due to the difficult to obtain a standard source with the same geometry of the filter cartridge, another technique is necessary to calibrate the detector. The technique described in this paper uses the Monte Carlo method for primary characterization of the IEA-R1 filter cartridges. (author)

  16. Advantages of a Laplace transform filtering integration scheme over semi-implicit methods in a global shallow water model

    Science.gov (United States)

    Clancy, Colm; Lynch, Peter

    2010-05-01

    A filtering numerical time-integration scheme is being developed. Using a modified inversion to the Laplace Transform (LT), the scheme is designed to remove spurious noise while faithfully simulating low frequency atmospheric modes. The method has been compared with traditional semi-implicit schemes in a shallow water framework and shows a number of advantages. In particular we are investigating the behaviour of a semi-Lagrangian formulation of the LT scheme in the presence of orography. We will also discuss its effects on the energy spectra of atmospheric simulations.

  17. Viral interference with antigen presentation: trapping TAP.

    Science.gov (United States)

    Ressing, Maaike E; Luteijn, Rutger D; Horst, Daniëlle; Wiertz, Emmanuel J

    2013-09-01

    Following primary infection, herpesviruses persist for life in their hosts, even when vigorous anti-viral immunity has been induced. Failure of the host immune system to eliminate infected cells is facilitated by highly effective immune evasion strategies acquired by these herpesviruses during millions of years of co-evolution with their hosts. Here, we review the mechanisms of action of viral gene products that lead to cytotoxic T cell evasion through interference with the function of the transporter associated with antigen processing, TAP. The viral TAP inhibitors impede transport of peptides from the cytosol into the ER lumen, thereby preventing peptide loading onto MHC class I complexes. Recent insights have revealed a pattern of functional convergent evolution. In every herpesvirus subfamily, inhibitors of TAP function have been identified that are, surprisingly, unrelated in genome location, structure, and mechanism of action. Recently, cowpox virus has also been found to encode a TAP inhibitor. Expanding our knowledge on how viruses perturb antigen presentation, in particular by targeting TAP, not only provides information on viral pathogenesis, but also reveals novel aspects of the cellular processes corrupted by these viruses, notably the translocation of peptides by the ATP-binding cassette (ABC) transporter TAP. As the various TAP inhibitors are anticipated to impede discrete conformational transitions it is expected that crystal structures of TAP-inhibitor complexes will reveal valuable structural information on the actual mechanism of peptide translocation by TAP. Viral TAP inhibitors are also used for various (clinical) applications, for example, as effective tools in antigen presentation studies and as immunomodulators in immunotherapy for cancer, heterologous vaccination, and transplant protection. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Effects of High-Stress Polymer Conditioning on the Filterability of Water and Wastewater Sludges.

    Science.gov (United States)

    1983-05-05

    with ferric chloride greatly improved filterability as well. Goodman and Witcher (1965) undertook studies to determine if polymers could be used to...to sludge holding facilities. Goodman and Witcher procurred washwater samples and tested the effects of polymer conditioning. They used three liter...Goodman, B.L., and Witcher , G., "Polymer Aided Sludge Treatment." Journal WPCF. Vol. 37, 12, 1643-1656 (1965). Hannah, S., Cohen, J.M., and Robeck, G.G

  19. A two-step crushed lava rock filter unit for grey water treatment at household level in an urban slum.

    Science.gov (United States)

    Katukiza, A Y; Ronteltap, M; Niwagaba, C B; Kansiime, F; Lens, P N L

    2014-01-15

    Decentralised grey water treatment in urban slums using low-cost and robust technologies offers opportunities to minimise public health risks and to reduce environmental pollution caused by the highly polluted grey water i.e. with a COD and N concentration of 3000-6000 mg L(-1) and 30-40 mg L(-1), respectively. However, there has been very limited action research to reduce the pollution load from uncontrolled grey water discharge by households in urban slums. This study was therefore carried out to investigate the potential of a two-step filtration process to reduce the grey water pollution load in an urban slum using a crushed lava rock filter, to determine the main filter design and operation parameters and the effect of intermittent flow on the grey water effluent quality. A two-step crushed lava rock filter unit was designed and implemented for use by a household in the Bwaise III slum in Kampala city (Uganda). It was monitored at a varying hydraulic loading rate (HLR) of 0.5-1.1 m d(-1) as well as at a constant HLR of 0.39 m d(-1). The removal efficiencies of COD, TP and TKN were, respectively, 85.9%, 58% and 65.5% under a varying HLR and 90.5%, 59.5% and 69%, when operating at a constant HLR regime. In addition, the log removal of Escherichia coli, Salmonella spp. and total coliforms was, respectively, 3.8, 3.2 and 3.9 under the varying HLR and 3.9, 3.5 and 3.9 at a constant HLR. The results show that the use of a two-step filtration process as well as a lower constant HLR increased the pollutant removal efficiencies. Further research is needed to investigate the feasibility of adding a tertiary treatment step to increase the nutrients and microorganisms removal from grey water. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Terrestrial water storage changes over Xinjiang extracted by combining Gaussian filter and multi-channel singular spectrum analysis from GRACE

    Science.gov (United States)

    Guo, Jinyun; Li, Wudong; Chang, Xiaotao; Zhu, Guangbin; Liu, Xin; Guo, Bin

    2018-01-01

    Water resource management is crucial for the economic and social development of Xinjiang, an arid area located in the Northwest China. In this paper, the time-variations of GRACE-derived monthly gravity field models from Jan. 2003 to Dec. 2013 are analyzed to study the terrestrial water storage (TWS) changes in Xinjiang using the multi-channel singular spectrum analysis (MSSA) with a Gaussian smoothing radius of 400 km. As an extended singular spectrum analysis (SSA), MSSA is more flexible to deal with multivariate time series in terms of estimating periodic components and trend, reducing noise and identifying patterns of similar spatiotemporal behavior thanks to the data-adaptive nature of the base functions. Combining MSSA and Gaussian filter can not only obviously remove the north-south striping errors in the GRACE solutions, but also reduce the leakage errors, which can increase the signal-to-noise ratio by comparing with the traditional procedure, i.e. empirical decorrelation method (EDM) followed with the Gaussian filtering. The spatiotemporal characteristics of TWS changes in Xinjiang were validated against the Global Land Dynamics Assimilation System (GLDAS), the Climate Prediction Center (CPC) and in-situ precipitation data. The water storage in Xinjiang shows the relatively large fluctuation from Jan. 2003 to Dec. 2013, with a drop from Jan. 2006 to Dec. 2008 due to the drought event and an obvious rise from Jan. 2009 to Dec. 2010 because of the high precipitation. Spatially, the terrestrial water storage has been increasing in the south Xinjiang, but decreasing in the north Xinjiang. The minimum rate of water storage change is -4.4 mm/yr occurring in the central Tianshan Moun