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Sample records for drinking water biofilms

  1. AFM Structural Characterization of Drinking Water Biofilm ...

    Science.gov (United States)

    Due to the complexity of mixed culture drinking water biofilm, direct visual observation under in situ conditions has been challenging. In this study, atomic force microscopy (AFM) revealed the three dimensional morphology and arrangement of drinking water relevant biofilm in air and aqueous solution. Operating parameters were optimized to improve imaging of structural details for a mature biofilm in liquid. By using a soft cantilever (0.03 N/m) and slow scan rate (0.5 Hz), biofilm and individual bacterial cell’s structural topography were resolved and continuously imaged in liquid without loss of spatial resolution or sample damage. The developed methodology will allow future in situ investigations to temporally monitor mixed culture drinking water biofilm structural changes during disinfection treatments. Due to the complexity of mixed culture drinking water biofilm, direct visual observation under in situ conditions has been challenging. In this study, atomic force microscopy (AFM) revealed the three dimensional morphology and arrangement of drinking water relevant biofilm in air and aqueous solution. Operating parameters were optimized to improve imaging of structural details for a mature biofilm in liquid. By using a soft cantilever (0.03 N/m) and slow scan rate (0.5 Hz), biofilm and individual bacterial cell’s structural topography were resolved and continuously imaged in liquid without loss of spatial resolution or sample damage. The developed methodo

  2. AFM Structural Characterization of Drinking Water Biofilm under Physiological Conditions

    Science.gov (United States)

    Due to the complexity of mixed culture drinking water biofilm, direct visual observation under in situ conditions has been challenging. In this study, atomic force microscopy (AFM) revealed the three dimensional morphology and arrangement of drinking water relevant biofilm in air...

  3. AFM Structural Characterization of Drinking Water Biofilm under Physiological Conditions

    Science.gov (United States)

    Due to the complexity of mixed culture drinking water biofilm, direct visual observation under in situ conditions has been challenging. In this study, atomic force microscopy (AFM) revealed the three dimensional morphology and arrangement of drinking water relevant biofilm in air...

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

    Science.gov (United States)

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

    2015-11-01

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

  5. Drinking water biofilm cohesiveness changes under chlorination or hydrodynamic stress.

    Science.gov (United States)

    Mathieu, L; Bertrand, I; Abe, Y; Angel, E; Block, J C; Skali-Lami, S; Francius, G

    2014-05-15

    Attempts at removal of drinking water biofilms rely on various preventive and curative strategies such as nutrient reduction in drinking water, disinfection or water flushing, which have demonstrated limited efficiency. The main reason for these failures is the cohesiveness of the biofilm driven by the physico-chemical properties of its exopolymeric matrix (EPS). Effective cleaning procedures should break up the matrix and/or change the elastic properties of bacterial biofilms. The aim of this study was to evaluate the change in the cohesive strength of two-month-old drinking water biofilms under increasing hydrodynamic shear stress τw (from ∼0.2 to ∼10 Pa) and shock chlorination (applied concentration at T0: 10 mg Cl2/L; 60 min contact time). Biofilm erosion (cell loss per unit surface area) and cohesiveness (changes in the detachment shear stress and cluster volumes measured by atomic force microscopy (AFM)) were studied. When rapidly increasing the hydrodynamic constraint, biofilm removal was found to be dependent on a dual process of erosion and coalescence of the biofilm clusters. Indeed, 56% of the biofilm cells were removed with, concomitantly, a decrease in the number of the 50-300 μm(3) clusters and an increase in the number of the smaller (i.e., 600 μm(3)) ones. Moreover, AFM evidenced the strengthening of the biofilm structure along with the doubling of the number of contact points, NC, per cluster volume unit following the hydrodynamic disturbance. This suggests that the compactness of the biofilm exopolymers increases with hydrodynamic stress. Shock chlorination removed cells (-75%) from the biofilm while reducing the volume of biofilm clusters. Oxidation stress resulted in a decrease in the cohesive strength profile of the remaining drinking water biofilms linked to a reduction in the number of contact points within the biofilm network structure in particular for the largest biofilm cluster volumes (>200 μm(3)). Changes in the cohesive

  6. Kinetics of biofilm formation by drinking water isolated Penicillium expansum.

    Science.gov (United States)

    Simões, Lúcia Chaves; Simões, Manuel; Lima, Nelson

    2015-01-01

    Current knowledge on drinking water (DW) biofilms has been obtained mainly from studies on bacterial biofilms. Very few reports on filamentous fungi (ff) biofilms are available, although they can contribute to the reduction in DW quality. This study aimed to assess the dynamics of biofilm formation by Penicillium expansum using microtiter plates under static conditions, mimicking water flow behaviour in stagnant regions of drinking water distribution systems. Biofilms were analysed in terms of biomass (crystal violet staining), metabolic activity (resazurin, fluorescein diacetate and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide [MTT]) and morphology (epifluorescence [calcofluor white M2R, FUN-1, FDA and acridine orange] and bright-field microscopies). Biofilm development over time showed the typical sigmoidal curve with noticeable different phases in biofilm formation (induction, exponential, stationary, and sloughing off). The methods used to assess metabolic activity provided similar results. The microscope analysis allowed identification of the involvement of conidia in initial adhesion (4 h), germlings (8 h), initial monolayers (12 h), a monolayer of intertwined hyphae (24 h), mycelial development, hyphal layering and bundling, and development of the mature biofilms (≥48 h). P. expansum grows as a complex, multicellular biofilm in 48 h. The metabolic activity and biomass of the fungal biofilms were shown to increase over time and a correlation between metabolism, biofilm mass and hyphal development was found.

  7. Bacterial community analysis of drinking water biofilms in southern Sweden.

    Science.gov (United States)

    Lührig, Katharina; Canbäck, Björn; Paul, Catherine J; Johansson, Tomas; Persson, Kenneth M; Rådström, Peter

    2015-01-01

    Next-generation sequencing of the V1-V2 and V3 variable regions of the 16S rRNA gene generated a total of 674,116 reads that described six distinct bacterial biofilm communities from both water meters and pipes. A high degree of reproducibility was demonstrated for the experimental and analytical work-flow by analyzing the communities present in parallel water meters, the rare occurrence of biological replicates within a working drinking water distribution system. The communities observed in water meters from households that did not complain about their drinking water were defined by sequences representing Proteobacteria (82-87%), with 22-40% of all sequences being classified as Sphingomonadaceae. However, a water meter biofilm community from a household with consumer reports of red water and flowing water containing elevated levels of iron and manganese had fewer sequences representing Proteobacteria (44%); only 0.6% of all sequences were classified as Sphingomonadaceae; and, in contrast to the other water meter communities, markedly more sequences represented Nitrospira and Pedomicrobium. The biofilm communities in pipes were distinct from those in water meters, and contained sequences that were identified as Mycobacterium, Nocardia, Desulfovibrio, and Sulfuricurvum. The approach employed in the present study resolved the bacterial diversity present in these biofilm communities as well as the differences that occurred in biofilms within a single distribution system, and suggests that next-generation sequencing of 16S rRNA amplicons can show changes in bacterial biofilm communities associated with different water qualities.

  8. Probing young drinking water biofilms with hard and soft particles.

    Science.gov (United States)

    Paris, Tony; Skali-Lami, Salaheddine; Block, Jean-Claude

    2009-01-01

    The aim of our study was to investigate, through the use of soft (Escherichia coli) and hard (polystyrene microspheres) particles, the distribution and persistence of allochthonous particles inoculated in drinking water flow chambers. Biofilms were allowed to grow for 7-10 months in tap water from Nancy's drinking water network and were composed of bacterial aggregates and filamentous fungi. Both model particles adhered almost exclusively on the biofilms (i.e. on the bacterial aggregates and on the filamentous structures) and not directly on the uncolonized walls (glass or Plexiglas). Biofilm age (i.e. bacterial density and biofilm properties) and convective-diffusion were found to govern particle accumulation: older biofilms and higher wall shear rates both increased the velocity and the amount of particle deposition on the biofilm. Persistence of the polystyrene particles was measured over a two-month period after inoculation. Accumulation amounts were found to be very different between hard and soft particles as only 0.03 per thousand of the soft particles inoculated accumulated in the biofilm against 0.3-0.8% for hard particles.

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

    Science.gov (United States)

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

    2013-10-01

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

  10. Dynamics of Biofilm Regrowth in Drinking Water Distribution Systems.

    Science.gov (United States)

    Douterelo, I; Husband, S; Loza, V; Boxall, J

    2016-07-15

    The majority of biomass within water distribution systems is in the form of attached biofilm. This is known to be central to drinking water quality degradation following treatment, yet little understanding of the dynamics of these highly heterogeneous communities exists. This paper presents original information on such dynamics, with findings demonstrating patterns of material accumulation, seasonality, and influential factors. Rigorous flushing operations repeated over a 1-year period on an operational chlorinated system in the United Kingdom are presented here. Intensive monitoring and sampling were undertaken, including time-series turbidity and detailed microbial analysis using 16S rRNA Illumina MiSeq sequencing. The results show that bacterial dynamics were influenced by differences in the supplied water and by the material remaining attached to the pipe wall following flushing. Turbidity, metals, and phosphate were the main factors correlated with the distribution of bacteria in the samples. Coupled with the lack of inhibition of biofilm development due to residual chlorine, this suggests that limiting inorganic nutrients, rather than organic carbon, might be a viable component in treatment strategies to manage biofilms. The research also showed that repeat flushing exerted beneficial selective pressure, giving another reason for flushing being a viable advantageous biofilm management option. This work advances our understanding of microbiological processes in drinking water distribution systems and helps inform strategies to optimize asset performance. This research provides novel information regarding the dynamics of biofilm formation in real drinking water distribution systems made of different materials. This new knowledge on microbiological process in water supply systems can be used to optimize the performance of the distribution network and to guarantee safe and good-quality drinking water to consumers. Copyright © 2016 Douterelo et al.

  11. Investigation of natural biofilms formed during the production of drinking water from surface water embankment filtration.

    Science.gov (United States)

    Emtiazi, Farahnaz; Schwartz, Thomas; Marten, Silke Mareike; Krolla-Sidenstein, Peter; Obst, Ursula

    2004-03-01

    Populations of bacteria in biofilms from different sites of a drinking water production system were analysed. Polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) analyses revealed changing DNA band patterns, suggesting a population shift during bank filtration and processing at the waterworks. In addition, common DNA bands that were attributed to ubiquitous bacteria were found. Biofilms even developed directly after UV disinfection (1-2m distance). Their DNA band patterns only partly agreed with those of the biofilms from the downstream distribution system. Opportunistic pathogenic bacteria in biofilms were analysed using PCR and Southern blot hybridisation (SBH). Surface water appeared to have a direct influence on the composition of biofilms in the drinking water distribution system. In spite of preceding filtration and UV disinfection, opportunistic pathogens such as atypical mycobacteria and Legionella spp. were found in biofilms of drinking water, and Pseudomonas aeruginosa was detected sporadically. Enterococci were not found in any biofilm. Bacterial cell counts in the biofilms from surface water to drinking water dropped significantly, and esterase and alanine-aminopeptidase activity decreased. beta-glucosidase activity was not found in the biofilms. Contrary to the results for planktonic bacteria, inhibitory effects were not observed in biofilms. This suggested an increased tolerance of biofilm bacteria against toxic compounds.

  12. Biofilm bacterial communities in urban drinking water distribution systems transporting waters with different purification strategies.

    Science.gov (United States)

    Wu, Huiting; Zhang, Jingxu; Mi, Zilong; Xie, Shuguang; Chen, Chao; Zhang, Xiaojian

    2015-02-01

    Biofilm formation in drinking water distribution systems (DWDS) has many adverse consequences. Knowledge of microbial community structure of DWDS biofilm can aid in the design of an effective control strategy. However, biofilm bacterial community in real DWDS and the impact of drinking water purification strategy remain unclear. The present study investigated the composition and diversity of biofilm bacterial community in real DWDSs transporting waters with different purification strategies (conventional treatment and integrated treatment). High-throughput Illumina MiSeq sequencing analysis illustrated a large shift in the diversity and structure of biofilm bacterial community in real DWDS. Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Nitrospirae, and Cyanobacteria were the major components of biofilm bacterial community. Proteobacteria (mainly Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria) predominated in each DWDS biofilm, but the compositions of the dominant proteobacterial classes and genera and their proportions varied among biofilm samples. Drinking water purification strategy could shape DWDS biofilm bacterial community. Moreover, Pearson's correlation analysis indicated that Actinobacteria was positively correlated with the levels of total alkalinity and dissolved organic carbon in tap water, while Firmicutes had a significant positive correlation with nitrite nitrogen.

  13. Reduced Efficiency of Chlorine Disinfection of Naegleria fowleri in a Drinking Water Distribution Biofilm.

    Science.gov (United States)

    Miller, Haylea C; Wylie, Jason; Dejean, Guillaume; Kaksonen, Anna H; Sutton, David; Braun, Kalan; Puzon, Geoffrey J

    2015-09-15

    Naegleria fowleri associated with biofilm and biological demand water (organic matter suspended in water that consumes disinfectants) sourced from operational drinking water distribution systems (DWDSs) had significantly increased resistance to chlorine disinfection. N. fowleri survived intermittent chlorine dosing of 0.6 mg/L for 7 days in a mixed biofilm from field and laboratory-cultured Escherichia coli strains. However, N. fowleri associated with an attached drinking water distribution biofilm survived more than 30 times (20 mg/L for 3 h) the recommended concentration of chlorine for drinking water. N. fowleri showed considerably more resistance to chlorine when associated with a real field biofilm compared to the mixed laboratory biofilm. This increased resistance is likely due to not only the consumption of disinfectants by the biofilm and the reduced disinfectant penetration into the biofilm but also the composition and microbial community of the biofilm itself. The increased diversity of the field biofilm community likely increased N. fowleri's resistance to chlorine disinfection compared to that of the laboratory-cultured biofilm. Previous research has been conducted in only laboratory scale models of DWDSs and laboratory-cultured biofilms. To the best of our knowledge, this is the first study demonstrating how N. fowleri can persist in a field drinking water distribution biofilm despite chlorination.

  14. Role of biofilm roughness and hydrodynamic conditions in Legionella pneumophila adhesion to and detachment from simulated drinking water biofilms.

    Science.gov (United States)

    Shen, Yun; Monroy, Guillermo L; Derlon, Nicolas; Janjaroen, Dao; Huang, Conghui; Morgenroth, Eberhard; Boppart, Stephen A; Ashbolt, Nicholas J; Liu, Wen-Tso; Nguyen, Thanh H

    2015-04-07

    Biofilms in drinking water distribution systems (DWDS) could exacerbate the persistence and associated risks of pathogenic Legionella pneumophila (L. pneumophila), thus raising human health concerns. However, mechanisms controlling adhesion and subsequent detachment of L. pneumophila associated with biofilms remain unclear. We determined the connection between L. pneumophila adhesion and subsequent detachment with biofilm physical structure characterization using optical coherence tomography (OCT) imaging technique. Analysis of the OCT images of multispecies biofilms grown under low nutrient condition up to 34 weeks revealed the lack of biofilm deformation even when these biofilms were exposed to flow velocity of 0.7 m/s, typical flow for DWDS. L. pneumophila adhesion on these biofilm under low flow velocity (0.007 m/s) positively correlated with biofilm roughness due to enlarged biofilm surface area and local flow conditions created by roughness asperities. The preadhered L. pneumophila on selected rough and smooth biofilms were found to detach when these biofilms were subjected to higher flow velocity. At the flow velocity of 0.1 and 0.3 m/s, the ratio of detached cell from the smooth biofilm surface was from 1.3 to 1.4 times higher than that from the rough biofilm surface, presumably because of the low shear stress zones near roughness asperities. This study determined that physical structure and local hydrodynamics control L. pneumophila adhesion to and detachment from simulated drinking water biofilm, thus it is the first step toward reducing the risk of L. pneumophila exposure and subsequent infections.

  15. Biofilm in water pipelines; a potential source for off-flavours in the drinking water.

    Science.gov (United States)

    Skjevrak, I; Lund, V; Ormerod, K; Due, A; Herikstad, H

    2004-01-01

    Volatile organic compounds (VOC) are identified in natural biofilm established in plastic pipes used at the drinking water supply. Odour potent VOCs such as ectocarpene, dictyopterene A and C', geosmin, beta-ionone, 6-methyl-5-hepten-2-one, menthol and menthone were prominent compounds in biofilm in the distribution network and at raw water test sites, and are associated with algae and cyanobacteria present in the raw water source.

  16. Metagenome Survey of Biofilms in Drinking-Water Networks

    Science.gov (United States)

    Schmeisser, C.; Stöckigt, C.; Raasch, C.; Wingender, J.; Timmis, K. N.; Wenderoth, D. F.; Flemming, H.-C.; Liesegang, H.; Schmitz, R. A.; Jaeger, K.-E.; Streit, W. R.

    2003-01-01

    Most naturally occurring biofilms contain a vast majority of microorganisms which have not yet been cultured, and therefore we have little information on the genetic information content of these communities. Therefore, we initiated work to characterize the complex metagenome of model drinking water biofilms grown on rubber-coated valves by employing three different strategies. First, a sequence analysis of 650 16S rRNA clones indicated a high diversity within the biofilm communities, with the majority of the microbes being closely related to the Proteobacteria. Only a small fraction of the 16S rRNA sequences were highly similar to rRNA sequences from Actinobacteria, low-G+C gram-positives and the Cytophaga-Flavobacterium-Bacteroides group. Our second strategy included a snapshot genome sequencing approach. Homology searches in public databases with 5,000 random sequence clones from a small insert library resulted in the identification of 2,200 putative protein-coding sequences, of which 1,026 could be classified into functional groups. Similarity analyses indicated that significant fractions of the genes and proteins identified were highly similar to known proteins observed in the genera Rhizobium, Pseudomonas, and Escherichia. Finally, we report 144 kb of DNA sequence information from four selected cosmid clones, of which two formed a 75-kb overlapping contig. The majority of the proteins identified by whole-cosmid sequencing probably originated from microbes closely related to the alpha-, beta-, and gamma-Proteobacteria. The sequence information was used to set up a database containing the phylogenetic and genomic information on this model microbial community. Concerning the potential health risk of the microbial community studied, no DNA or protein sequences directly linked to pathogenic traits were identified. PMID:14660379

  17. Bulk water phase and biofilm growth in drinking water at low nutrient conditions

    DEFF Research Database (Denmark)

    Boe-Hansen, Rasmus; Albrechtsen, Hans-Jørgen; Arvin, Erik

    2002-01-01

    to quantify the effect of retention times at hydraulic conditions similar to those in drinking water distribution networks. Water and pipe wall samples were taken and examined during the experiment. The pipes had been exposed to drinking water at approximately 131C, for at least 385 days to allow......In this study, the bacterial growth dynamics of a drinking water distribution system at low nutrient conditions was studied in order to determine bacterial growth rates by a range of methods, and to compare growth rates in the bulk water phase and the biofilm. A model distribution system was used...... the formation of a mature quasi-stationary biofilm. At retention times of 12 h, total bacterial counts increased equivalent to a net bacterial growth rate of 0.048 day1. The bulk water phase bacteria exhibited a higher activity than the biofilmbacteria in terms of culturability, cell-specific ATP content...

  18. Fate of Salmonella Typhimurium in laboratory-scale drinking water biofilms

    CSIR Research Space (South Africa)

    Schaefer, Lisa M

    2013-08-01

    Full Text Available and thus allows in situ detection of undisturbed cells and is ideally suited for monitoring Salmonella in biofilms. The fate and persistence of non-typhoidal Salmonella in simulated drinking water biofilms was investigated. The ability of Salmonella to form...

  19. Effect of sodium hypochlorite on typical biofilms formed in drinking water distribution systems.

    Science.gov (United States)

    Lin, Huirong; Zhu, Xuan; Wang, Yuxin; Yu, Xin

    2017-04-01

    Human health and biological safety problems resulting from urban drinking water pipe network biofilms pollution have attracted wide concern. Despite the inclusion of residual chlorine in drinking water distribution systems supplies, the bacterium is a recalcitrant human pathogen capable of forming biofilms on pipe walls and causing health risks. Typical drinking water bacterial biofilms and their response to different concentrations of chlorination was monitored. The results showed that the four bacteria all formed single biofilms susceptible to sodium hypochlorite. After 30 min disinfection, biomass and cultivability decreased with increasing concentration of disinfectant but then increased in high disinfectant doses. PMA-qPCR results indicated that it resulted in little cellular damage. Flow cytometry analysis showed that with increasing doses of disinfectant, the numbers of clusters increased and the sizes of clusters decreased. Under high disinfectant treatment, EPS was depleted by disinfectant and about 0.5-1 mg/L of residual chlorine seemed to be appropriate for drinking water treatment. This research provides an insight into the EPS protection to biofilms. Resistance of biofilms against high levels of chlorine has implications for the delivery of drinking water.

  20. Adhesion and biofilm formation on polystyrene by drinking water-isolated bacteria.

    Science.gov (United States)

    Simões, Lúcia Chaves; Simões, Manuel; Vieira, Maria João

    2010-10-01

    This study was performed in order to characterize the relationship between adhesion and biofilm formation abilities of drinking water-isolated bacteria (Acinetobacter calcoaceticus, Burkholderia cepacia, Methylobacterium sp., Mycobacterium mucogenicum, Sphingomonas capsulata and Staphylococcus sp.). Adhesion was assessed by two distinct methods: thermodynamic prediction of adhesion potential by quantifying hydrophobicity and the free energy of adhesion; and by microtiter plate assays. Biofilms were developed in microtiter plates for 24, 48 and 72 h. Polystyrene (PS) was used as adhesion substratum. The tested bacteria had negative surface charge and were hydrophilic. PS had negative surface charge and was hydrophobic. The free energy of adhesion between the bacteria and PS was > 0 mJ/m(2) (thermodynamic unfavorable adhesion). The thermodynamic approach was inappropriate for modelling adhesion of the tested drinking water bacteria, underestimating adhesion to PS. Only three (B. cepacia, Sph. capsulata and Staphylococcus sp.) of the six bacteria were non-adherent to PS. A. calcoaceticus, Methylobacterium sp. and M. mucogenicum were weakly adherent. This adhesion ability was correlated with the biofilm formation ability when comparing with the results of 24 h aged biofilms. Methylobacterium sp. and M. mucogenicum formed large biofilm amounts, regardless the biofilm age. Given time, all the bacteria formed biofilms; even those non-adherents produced large amounts of matured (72 h aged) biofilms. The overall results indicate that initial adhesion did not predict the ability of the tested drinking water-isolated bacteria to form a mature biofilm, suggesting that other events such as phenotypic and genetic switching during biofilm development and the production of extracellular polymeric substances (EPS), may play a significant role on biofilm formation and differentiation. This understanding of the relationship between adhesion and biofilm formation is important for

  1. Preferential colonization and release of Legionella pneumophila from mature drinking water biofilms grown on copper versus unplasticized polyvinylchloride coupons

    Science.gov (United States)

    Legionella persistence and amplification in premise drinking water systems is a known contributor to legionellosis outbreaks, especially in the presence of suitable eukaryotic hosts. Here we examined Legionella pneumophila behavior within drinking water biofilms grown on copper ...

  2. Elimination of Naegleria fowleri from bulk water and biofilm in an operational drinking water distribution system.

    Science.gov (United States)

    Miller, Haylea C; Morgan, Matthew J; Wylie, Jason T; Kaksonen, Anna H; Sutton, David; Braun, Kalan; Puzon, Geoffrey J

    2017-03-01

    Global incidence of primary amoebic meningoencephalitis cases associated with domestic drinking water is increasing. The need for understanding disinfectant regimes capable of eliminating the causative microorganism, Naegleria fowleri, from bulk water and pipe wall biofilms is critical. This field study demonstrated the successful elimination of N. fowleri from the bulk water and pipe wall biofilm of a persistently colonised operational drinking water distribution system (DWDS), and the prevention of further re-colonisation. A new chlorination unit was installed along the pipe line to boost the free chlorine residual to combat the persistence of N. fowleri. Biofilm and bulk water were monitored prior to and after re-chlorination (RCl), pre-rechlorination (pre-RCl) and post-rechlorination (post-RCl), respectively, for one year. A constant free chlorine concentration of > 1 mg/L resulted in the elimination of N. fowleri from both the bulk water and biofilm at the post-RCl site. Other amoeba species were detected during the first two months of chlorination, but all amoebae were eliminated from both the bulk water and biofilm at post-RCl after 60 days of chlorination with free chlorine concentrations > 1 mg/L. In addition, a dynamic change in the biofilm community composition and a four log reduction in biofilm cell density occurred post-RCl. The pre-RCl site continued to be seasonally colonised by N. fowleri, but the constant free chlorine residual of > 1 mg/L prevented N. fowleri from recolonising the bulk and pipe wall biofilm at the post-RCl site. To our knowledge, this is the first study to demonstrate successful removal of N. fowleri from both the bulk and pipe wall biofilm and prevention of re-colonisation of N. fowleri in an operational DWDS. The findings of this study are of importance to water utilities in addressing the presence of N. fowleri and other amoeba in susceptible DWDSs.

  3. Temporal variations in the abundance and composition of biofilm communities colonizing drinking water distribution pipes.

    Directory of Open Access Journals (Sweden)

    John J Kelly

    Full Text Available Pipes that transport drinking water through municipal drinking water distribution systems (DWDS are challenging habitats for microorganisms. Distribution networks are dark, oligotrophic and contain disinfectants; yet microbes frequently form biofilms attached to interior surfaces of DWDS pipes. Relatively little is known about the species composition and ecology of these biofilms due to challenges associated with sample acquisition from actual DWDS. We report the analysis of biofilms from five pipe samples collected from the same region of a DWDS in Florida, USA, over an 18 month period between February 2011 and August 2012. The bacterial abundance and composition of biofilm communities within the pipes were analyzed by heterotrophic plate counts and tag pyrosequencing of 16S rRNA genes, respectively. Bacterial numbers varied significantly based on sampling date and were positively correlated with water temperature and the concentration of nitrate. However, there was no significant relationship between the concentration of disinfectant in the drinking water (monochloramine and the abundance of bacteria within the biofilms. Pyrosequencing analysis identified a total of 677 operational taxonomic units (OTUs (3% distance within the biofilms but indicated that community diversity was low and varied between sampling dates. Biofilms were dominated by a few taxa, specifically Methylomonas, Acinetobacter, Mycobacterium, and Xanthomonadaceae, and the dominant taxa within the biofilms varied dramatically between sampling times. The drinking water characteristics most strongly correlated with bacterial community composition were concentrations of nitrate, ammonium, total chlorine and monochloramine, as well as alkalinity and hardness. Biofilms from the sampling date with the highest nitrate concentration were the most abundant and diverse and were dominated by Acinetobacter.

  4. Effect of Disinfectant Exposure on Legionella pneumophila Associated with Simulated Drinking Water Biofilms: Release, Inactivation, and Infectivity.

    Science.gov (United States)

    Shen, Yun; Huang, Conghui; Lin, Jie; Wu, Wenjing; Ashbolt, Nicholas J; Liu, Wen-Tso; Nguyen, Thanh H

    2017-02-21

    Legionella pneumophila, the most commonly identified causative agent in drinking water associated with disease outbreaks, can be harbored by and released from drinking water biofilms. In this study, the release of biofilm-associated L. pneumophila under simulated drinking water flow containing a disinfectant residual was examined. Meanwhile, the inactivation and infectivity (to amoebae) of the released L. pneumophila were studied. To simulate drinking water system conditions, biofilms were prepared under either disinfectant exposure (predisinfected biofilms) or disinfectant-free (untreated biofilms) conditions, respectively. For experiments with water flow containing a disinfectant to release the biofilm-associated L. pneumophila from these two types of biofilms, the L. pneumophila release kinetics values from predisinfected and untreated biofilms under flow condition were not statistically different (one-way ANOVA, p > 0.05). However, inactivation of the L. pneumophila released from predisinfected biofilms was 1-2 times higher and amoeba infectivity was 2-29 times lower than that from untreated biofilms. The higher disinfectant resistance of L. pneumophila released from untreated biofilms was presumably influenced by the detachment of a larger amount of biofilm material (determined by 16S rRNA qPCR) surrounding the released L. pneumophila. This study highlights the interaction among disinfectant residual, biofilms, and L. pneumophila, which provides guidelines to assess and control pathogen risk.

  5. Multi-species biofilms defined from drinking water microorganisms provide increased protection against chlorine disinfection.

    Science.gov (United States)

    Schwering, Monika; Song, Joanna; Louie, Marie; Turner, Raymond J; Ceri, Howard

    2013-09-01

    A model biofilm, formed of multiple species from environmental drinking water, including opportunistic pathogens, was created to explore the tolerance of multi-species biofilms to chlorine levels typical of water-distribution systems. All species, when grown planktonically, were killed by concentrations of chlorine within the World Health Organization guidelines (0.2-5.0 mg l(-1)). Higher concentrations (1.6-40-fold) of chlorine were required to eradicate biofilm populations of these strains, ~70% of biofilms tested were not eradicated by 5.0 mg l(-1) chlorine. Pathogenic bacteria within the model multi-species biofilms had an even more substantial increase in chlorine tolerance; on average ~700-1100 mg l(-1) chlorine was required to eliminate pathogens from the biofilm, 50-300-fold higher than for biofilms comprising single species. Confocal laser scanning microscopy of biofilms showed distinct 3D structures and multiple cell morphologies and arrangements. Overall, this study showed a substantial increase in the chlorine tolerance of individual species with co-colonization in a multi-species biofilm that was far beyond that expected as a result of biofilm growth on its own.

  6. Diversity and functions of bacterial community in drinking water biofilms revealed by high-throughput sequencing

    Science.gov (United States)

    Chao, Yuanqing; Mao, Yanping; Wang, Zhiping; Zhang, Tong

    2015-01-01

    The development of biofilms in drinking water (DW) systems may cause various problems to water quality. To investigate the community structure of biofilms on different pipe materials and the global/specific metabolic functions of DW biofilms, PCR-based 454 pyrosequencing data for 16S rRNA genes and Illumina metagenomic data were generated and analysed. Considerable differences in bacterial diversity and taxonomic structure were identified between biofilms formed on stainless steel and biofilms formed on plastics, indicating that the metallic materials facilitate the formation of higher diversity biofilms. Moreover, variations in several dominant genera were observed during biofilm formation. Based on PCA analysis, the global functions in the DW biofilms were similar to other DW metagenomes. Beyond the global functions, the occurrences and abundances of specific protective genes involved in the glutathione metabolism, the SoxRS system, the OxyR system, RpoS regulated genes, and the production/degradation of extracellular polymeric substances were also evaluated. A near-complete and low-contamination draft genome was constructed from the metagenome of the DW biofilm, based on the coverage and tetranucleotide frequencies, and identified as a Bradyrhizobiaceae-like bacterium according to a phylogenetic analysis. Our findings provide new insight into DW biofilms, especially in terms of their metabolic functions. PMID:26067561

  7. Response of Simulated Drinking Water Biofilm Mechanical and Structural Properties to Long-Term Disinfectant Exposure.

    Science.gov (United States)

    Shen, Yun; Huang, Conghui; Monroy, Guillermo L; Janjaroen, Dao; Derlon, Nicolas; Lin, Jie; Espinosa-Marzal, Rosa; Morgenroth, Eberhard; Boppart, Stephen A; Ashbolt, Nicholas J; Liu, Wen-Tso; Nguyen, Thanh H

    2016-02-16

    Mechanical and structural properties of biofilms influence the accumulation and release of pathogens in drinking water distribution systems (DWDS). Thus, understanding how long-term residual disinfectants exposure affects biofilm mechanical and structural properties is a necessary aspect for pathogen risk assessment and control. In this study, elastic modulus and structure of groundwater biofilms was monitored by atomic force microscopy (AFM) and optical coherence tomography (OCT) during three months of exposure to monochloramine or free chlorine. After the first month of disinfectant exposure, the mean stiffness of monochloramine- or free-chlorine-treated biofilms was 4 to 9 times higher than those before treatment. Meanwhile, the biofilm thickness decreased from 120 ± 8 μm to 93 ± 6-107 ± 11 μm. The increased surface stiffness and decreased biofilm thickness within the first month of disinfectant exposure was presumably due to the consumption of biomass. However, by the second to third month during disinfectant exposure, the biofilm mean stiffness showed a 2- to 4-fold decrease, and the biofilm thickness increased to 110 ± 7-129 ± 8 μm, suggesting that the biofilms adapted to disinfectant exposure. After three months of the disinfectant exposure process, the disinfected biofilms showed 2-5 times higher mean stiffness (as determined by AFM) and 6-13-fold higher ratios of protein over polysaccharide, as determined by differential staining and confocal laser scanning microscopy (CLSM), than the nondisinfected groundwater biofilms. However, the disinfected biofilms and nondisinfected biofilms showed statistically similar thicknesses (t test, p > 0.05), suggesting that long-term disinfection may not significantly remove net biomass. This study showed how biofilm mechanical and structural properties vary in response to a complex DWDS environment, which will contribute to further research on the risk assessment and control of biofilm-associated-pathogens in DWDS.

  8. Understanding, Monitoring, and Controlling Biofilm Growth in Drinking Water Distribution Systems.

    Science.gov (United States)

    Liu, Sanly; Gunawan, Cindy; Barraud, Nicolas; Rice, Scott A; Harry, Elizabeth J; Amal, Rose

    2016-09-06

    In drinking water distribution systems (DWDS), biofilms are the predominant mode of microbial growth, with the presence of extracellular polymeric substance (EPS) protecting the biomass from environmental and shear stresses. Biofilm formation poses a significant problem to the drinking water industry as a potential source of bacterial contamination, including pathogens, and, in many cases, also affecting the taste and odor of drinking water and promoting the corrosion of pipes. This article critically reviews important research findings on biofilm growth in DWDS, examining the factors affecting their formation and characteristics as well as the various technologies to characterize and monitor and, ultimately, to control their growth. Research indicates that temperature fluctuations potentially affect not only the initial bacteria-to-surface attachment but also the growth rates of biofilms. For the latter, the effect is unique for each type of biofilm-forming bacteria; ammonia-oxidizing bacteria, for example, grow more-developed biofilms at a typical summer temperature of 22 °C compared to 12 °C in fall, and the opposite occurs for the pathogenic Vibrio cholerae. Recent investigations have found the formation of thinner yet denser biofilms under high and turbulent flow regimes of drinking water, in comparison to the more porous and loosely attached biofilms at low flow rates. Furthermore, in addition to the rather well-known tendency of significant biofilm growth on corrosion-prone metal pipes, research efforts also found leaching of growth-promoting organic compounds from the increasingly popular use of polymer-based pipes. Knowledge of the unique microbial members of drinking water biofilms and, importantly, the influence of water characteristics and operational conditions on their growth can be applied to optimize various operational parameters to minimize biofilm accumulation. More-detailed characterizations of the biofilm population size and structure are now

  9. Dynamics of biofilm formation in a model drinking water distribution system

    DEFF Research Database (Denmark)

    Boe-Hansen, Rasmus; Albrechtsen, Hans-Jørgen; Arvin, Erik

    2002-01-01

    determinations. The biofilm grew at a rate of 0.030±0.002 day−1 reaching quasi-stationary state at 2.6×106 cells/cm2 after approximately 200 days. The low substrate level in the bulk phase (AOC at approximately 6 g ac-C/l) most likely caused the relatively slow biofilm formation rate observed. During......The dynamics of biofilm formation in non-chlorinated groundwater-based drinking water was studied in a model distribution system. The formation of biofilm was closely monitored for a period of 522 days by total bacterial counts (AODC), heterotrophic plate counts (R2A media), and ATP content...... the maturation of the biofilm, the bacterial community changed properties in terms of cell-specific ATP content and culturability of the bacteria....

  10. Microbial analysis of in situ biofilm formation in drinking water distribution systems: implications for monitoring and control of drinking water quality.

    Science.gov (United States)

    Douterelo, Isabel; Jackson, M; Solomon, C; Boxall, J

    2016-04-01

    Biofilm formation in drinking water distribution systems (DWDS) is influenced by the source water, the supply infrastructure and the operation of the system. A holistic approach was used to advance knowledge on the development of mixed species biofilms in situ, by using biofilm sampling devices installed in chlorinated networks. Key physico-chemical parameters and conventional microbial indicators for drinking water quality were analysed. Biofilm coverage on pipes was evaluated by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The microbial community structure, bacteria and fungi, of water and biofilms was assessed using pyrosequencing. Conventional wisdom leads to an expectation for less microbial diversity in groundwater supplied systems. However, the analysis of bulk water showed higher microbial diversity in groundwater site samples compared with the surface water site. Conversely, higher diversity and richness were detected in biofilms from the surface water site. The average biofilm coverage was similar among sites. Disinfection residual and other key variables were similar between the two sites, other than nitrates, alkalinity and the hydraulic conditions which were extremely low at the groundwater site. Thus, the unexpected result of an exceptionally low diversity with few dominant genera (Pseudomonas and Basidiobolus) in groundwater biofilm samples, despite the more diverse community in the bulk water, is attributed to the low-flow hydraulic conditions. This finding evidences that the local environmental conditions are shaping biofilm formation, composition and amount, and hence managing these is critical for the best operation of DWDS to safeguard water quality.

  11. Establishment and Early Succession of Bacterial Communities in Monochloramine-treated Drinking Water Biofilms

    Science.gov (United States)

    The use of monochloramine as drinking water disinfectant is increasing because it forms lower levels of traditional disinfection by-products compared to free-chlorine. However, little is known about the bacterial succession within biofilms in monochloramine-treated systems. The d...

  12. Monitoring of biofilm formation and activity in drinking water distribution networks under oligotrophic conditions

    DEFF Research Database (Denmark)

    Boe-Hansen, Rasmus; Martiny, Adam Camillo; Arvin, Erik

    2003-01-01

    In this study, the construction a model distribution system suitable for studies of attached and suspended microbial activity in drinking water under controlled circumstances is outlined. The model system consisted of two loops connected in series with a total of 140 biofilm sampling points...

  13. Molecular analysis of bacterial communities in biofilms of a drinking water clearwell.

    Science.gov (United States)

    Zhang, Minglu; Liu, Wenjun; Nie, Xuebiao; Li, Cuiping; Gu, Junnong; Zhang, Can

    2012-01-01

    Microbial community structures in biofilms of a clearwell in a drinking water supply system in Beijing, China were examined by clone library, terminal restriction fragment length polymorphism (T-RFLP) and 454 pyrosequencing of the amplified 16S rRNA gene. Six biofilm samples (designated R1-R6) collected from six locations (upper and lower sites of the inlet, middle and outlet) of the clearwell revealed similar bacterial patterns by T-RFLP analysis. With respect to the dominant groups, the phylotypes detected by clone library and T-RFLP generally matched each other. A total of 9,543 reads were obtained from samples located at the lower inlet and the lower outlet sites by pyrosequencing. The bacterial diversity of the two samples was compared at phylum and genus levels. Alphaproteobacteria dominated the communities in both samples and the genus of Sphingomonas constituted 75.1%-99.6% of this phylum. A high level of Sphingomonas sp. was first observed in the drinking water biofilms with 0.6-1.0 mg L(-1) of chlorine residual. Disinfectant-resistant microorganisms deserve special attention in drinking water management. This study provides novel insights into the microbial populations in drinking water systems and highlights the important role of Sphingomonas species in biofilm formation.

  14. Establishment and Early Succession of Bacterial Communities in Monochloramine-Treated Drinking Water Biofilms

    Science.gov (United States)

    Monochloramine is increasingly used as a drinking water disinfectant because it forms lower levels of regulated disinfection by-products. While its use has been shown to increase nitrifying bacteria, little is known about the bacterial succession within biofilms in monochloramin...

  15. Changes in bacterial composition of biofilm in a metropolitan drinking water distribution system.

    Science.gov (United States)

    Revetta, R P; Gomez-Alvarez, V; Gerke, T L; Santo Domingo, J W; Ashbolt, N J

    2016-07-01

    This study examined the development of bacterial biofilms within a metropolitan distribution system. The distribution system is fed with different source water (i.e. groundwater, GW and surface water, SW) and undergoes different treatment processes in separate facilities. The biofilm community was characterized using 16S rRNA gene clone libraries and functional potential analysis, generated from total DNA extracted from coupons in biofilm annular reactors fed with onsite drinking water for up to 18 months. Differences in the bacterial community structure were observed between GW and SW. Representatives that explained the dissimilarity were associated with the classes Betaproteobacteria, Alphaproteobacteria, Actinobacteria, Gammaproteobacteria and Firmicutes. After 9 months the biofilm bacterial community from both GW and SW were dominated by Mycobacterium species. The distribution of the dominant operational taxonomic unit (OTU) (Mycobacterium) positively correlated with the drinking water distribution system (DWDS) temperature. In this study, the biofilm community structure observed between GW and SW were dissimilar, while communities from different locations receiving SW did not show significant differences. The results suggest that source water and/or the water quality shaped by their respective treatment processes may play an important role in shaping the bacterial communities in the distribution system. In addition, several bacterial groups were present in all samples, suggesting that they are an integral part of the core microbiota of this DWDS. These results provide an ecological insight into biofilm bacterial structure in chlorine-treated drinking water influenced by different water sources and their respective treatment processes. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  16. Biofilms in drinking water and their role as reservoir for pathogens.

    Science.gov (United States)

    Wingender, Jost; Flemming, Hans-Curt

    2011-11-01

    Most microorganisms on Earth live in various aggregates which are generally termed "biofilms". They are ubiquitous and represent the most successful form of life. They are the active agent in biofiltration and the carriers of the self-cleaning potential in soils, sediments and water. They are also common on surfaces in technical systems where they sometimes cause biofouling. In recent years it has become evident that biofilms in drinking water distribution networks can become transient or long-term habitats for hygienically relevant microorganisms. Important categories of these organisms include faecal indicator bacteria (e.g., Escherichia coli), obligate bacterial pathogens of faecal origin (e.g., Campylobacter spp.) opportunistic bacteria of environmental origin (e.g., Legionella spp., Pseudomonas aeruginosa), enteric viruses (e.g., adenoviruses, rotaviruses, noroviruses) and parasitic protozoa (e.g., Cryptosporidium parvum). These organisms can attach to preexisting biofilms, where they become integrated and survive for days to weeks or even longer, depending on the biology and ecology of the organism and the environmental conditions. There are indications that at least a part of the biofilm populations of pathogenic bacteria persists in a viable but non-culturable (VBNC) state and remains unnoticed by the methods appointed to their detection. Thus, biofilms in drinking water systems can serve as an environmental reservoir for pathogenic microorganisms and represent a potential source of water contamination, resulting in a potential health risk for humans if left unnoticed.

  17. Evaluation of methods for the extraction of DNA from drinking water distribution system biofilms.

    Science.gov (United States)

    Hwang, Chiachi; Ling, Fangqiong; Andersen, Gary L; LeChevallier, Mark W; Liu, Wen-Tso

    2012-01-01

    While drinking water biofilms have been characterized in various drinking water distribution systems (DWDS), little is known about the impact of different DNA extraction methods on the subsequent analysis of microbial communities in drinking water biofilms. Since different DNA extraction methods have been shown to affect the outcome of microbial community analysis in other environments, it is necessary to select a DNA extraction method prior to the application of molecular tools to characterize the complex microbial ecology of the DWDS. This study compared the quantity and quality of DNA yields from selected DWDS bacteria with different cell wall properties using five widely used DNA extraction methods. These were further selected and evaluated for their efficiency and reproducibility of DNA extraction from DWDS samples. Terminal restriction fragment length analysis and the 454 pyrosequencing technique were used to interpret the differences in microbial community structure and composition, respectively, from extracted DNA. Such assessments serve as a concrete step towards the determination of an optimal DNA extraction method for drinking water biofilms, which can then provide a reliable comparison of the meta-analysis results obtained in different laboratories.

  18. Monitoring of biofilm formation and activity in drinking water distribution networks under oligotrophic conditions

    DEFF Research Database (Denmark)

    Boe-Hansen, Rasmus; Martiny, Adam Camillo; Arvin, Erik

    2003-01-01

    In this study, the construction a model distribution system suitable for studies of attached and suspended microbial activity in drinking water under controlled circumstances is outlined. The model system consisted of two loops connected in series with a total of 140 biofilm sampling points....... The biofilm from the system was studied using 11 different microbial methods and the results were compared and discussed. The methods were used for biomass quantification (AODC, HPC and ATP determination), visualisation of structure (CLSM), activity measurement (leucine incorporation, AOC removal rate...

  19. Molecular Analysis of Bacterial Communities in Biofilms of a Drinking Water Clearwell

    OpenAIRE

    Zhang, Minglu; Liu, Wenjun; Nie, Xuebiao; Li, Cuiping; Gu, Junnong; Zhang, Can

    2012-01-01

    Microbial community structures in biofilms of a clearwell in a drinking water supply system in Beijing, China were examined by clone library, terminal restriction fragment length polymorphism (T-RFLP) and 454 pyrosequencing of the amplified 16S rRNA gene. Six biofilm samples (designated R1–R6) collected from six locations (upper and lower sites of the inlet, middle and outlet) of the clearwell revealed similar bacterial patterns by T-RFLP analysis. With respect to the dominant groups, the phy...

  20. Core-satellite populations and seasonality of water meter biofilms in a metropolitan drinking water distribution system.

    Science.gov (United States)

    Ling, Fangqiong; Hwang, Chiachi; LeChevallier, Mark W; Andersen, Gary L; Liu, Wen-Tso

    2016-03-01

    Drinking water distribution systems (DWDSs) harbor the microorganisms in biofilms and suspended communities, yet the diversity and spatiotemporal distribution have been studied mainly in the suspended communities. This study examined the diversity of biofilms in an urban DWDS, its relationship with suspended communities and its dynamics. The studied DWDS in Urbana, Illinois received conventionally treated and disinfected water sourced from the groundwater. Over a 2-year span, biomass were sampled from household water meters (n=213) and tap water (n=20) to represent biofilm and suspended communities, respectively. A positive correlation between operational taxonomic unit (OTU) abundance and occupancy was observed. Examined under a 'core-satellite' model, the biofilm community comprised 31 core populations that encompassed 76.7% of total 16 S rRNA gene pyrosequences. The biofilm communities shared with the suspended community highly abundant and prevalent OTUs, which related to methano-/methylotrophs (i.e., Methylophilaceae and Methylococcaceae) and aerobic heterotrophs (Sphingomonadaceae and Comamonadaceae), yet differed by specific core populations and lower diversity and evenness. Multivariate tests indicated seasonality as the main contributor to community structure variation. This pattern was resilient to annual change and correlated to the cyclic fluctuations of core populations. The findings of a distinctive biofilm community assemblage and methano-/methyltrophic primary production provide critical insights for developing more targeted water quality monitoring programs and treatment strategies for groundwater-sourced drinking water systems.

  1. Assessing the impact of water treatment on bacterial biofilms in drinking water distribution systems using high-throughput DNA sequencing.

    Science.gov (United States)

    Shaw, Jennifer L A; Monis, Paul; Fabris, Rolando; Ho, Lionel; Braun, Kalan; Drikas, Mary; Cooper, Alan

    2014-12-01

    Biofilm control in drinking water distribution systems (DWDSs) is crucial, as biofilms are known to reduce flow efficiency, impair taste and quality of drinking water and have been implicated in the transmission of harmful pathogens. Microorganisms within biofilm communities are more resistant to disinfection compared to planktonic microorganisms, making them difficult to manage in DWDSs. This study evaluates the impact of four unique drinking water treatments on biofilm community structure using metagenomic DNA sequencing. Four experimental DWDSs were subjected to the following treatments: (1) conventional coagulation, (2) magnetic ion exchange contact (MIEX) plus conventional coagulation, (3) MIEX plus conventional coagulation plus granular activated carbon, and (4) membrane filtration (MF). Bacterial biofilms located inside the pipes of each system were sampled under sterile conditions both (a) immediately after treatment application ('inlet') and (b) at a 1 km distance from the treatment application ('outlet'). Bacterial 16S rRNA gene sequencing revealed that the outlet biofilms were more diverse than those sampled at the inlet for all treatments. The lowest number of unique operational taxonomic units (OTUs) and lowest diversity was observed in the MF inlet. However, the MF system revealed the greatest increase in diversity and OTU count from inlet to outlet. Further, the biofilm communities at the outlet of each system were more similar to one another than to their respective inlet, suggesting that biofilm communities converge towards a common established equilibrium as distance from treatment application increases. Based on the results, MF treatment is most effective at inhibiting biofilm growth, but a highly efficient post-treatment disinfection regime is also critical in order to prevent the high rates of post-treatment regrowth.

  2. Effect of wall shear rate on biofilm deposition and grazing in drinking water flow chambers.

    Science.gov (United States)

    Paris, Tony; Skali-Lami, Salaheddine; Block, Jean-Claude

    2007-08-15

    The effect of four-wall shear rates (34.9, 74.8, 142.5, and 194.5 s(-1)) on bacterial deposition on glass slides in drinking water flow chambers was studied. Biofilm image acquisition was performed over a 50-day period. Bacterial accumulation and surface coverage curves were obtained. Microscopic observations allowed us to obtain information about the dynamics and spatial distribution of the biofilm. During the first stage of biofilm formation (210-518 h), bacterial accumulation was a function of the wall shear rate: the higher the wall shear rate, the faster the bacterial deposition (1.1 and 1.9 x 10(4) bacterial cells . cm(-2) for wall shear rates of 34.9 and 142.5 s(-1), respectively). A new similarity relationship characteristic of a non-dimensional time and function of the wall shear rate was proposed to describe initial bacterial deposition. After 50 days of exposure to drinking water, surface coverage was more or less identical under the entire wall shear rates (7.44 +/- 0.9%), suggesting that biofilm bacterial density cannot be controlled using hydrodynamics. However, the spatial distribution of the biofilm was clearly different. Under low wall shear rate, aggregates were composed of bacterial cells able to "vibrate" independently on the surface, whereas, under a high wall shear rate, aggregates were more cohesive. Therefore, susceptibility to the hydraulic discontinuities occurring in drinking water system may not be similar. In all the flow chambers, significant decreases in bacterial biomass (up to 77%) were associated with the presence of amoebae. This grazing preferentially targeted small, isolated cells.

  3. Microbiological contamination and resistance genes in biofilms occurring during the drinking water treatment process.

    Science.gov (United States)

    Farkas, Anca; Butiuc-Keul, Anca; Ciatarâş, Dorin; Neamţu, Călin; Crăciunaş, Cornelia; Podar, Dorina; Drăgan-Bularda, Mihail

    2013-01-15

    Biofilms are the predominant mode of microbial growth in drinking water systems. A dynamic exchange of individuals occurs between the attached and planktonic populations, while lateral gene transfer mediates genetic exchange in these bacterial communities. Integrons are important vectors for the spread of antimicrobial resistance. The presence of class 1 integrons (intI1, qac and sul genes) was assessed in biofilms occurring throughout the drinking water treatment process. Isolates from general and specific culture media, covering a wide range of environmental bacteria, fecal indicators and opportunistic pathogens were tested. From 96 isolates tested, 9.37% were found to possess genetic determinants of putative antimicrobial resistance, and these occurred in both Gram-positive and Gram-negative bacteria. Class 1 integron integrase gene was present in 8.33% of bacteria, all positive for the qacEΔ1 gene. The sul1 gene was present in 3.12% of total isolates, representing 37.5% of the class 1 integron positive cells. The present study shows that biofilm communities in a drinking water treatment plant are a reservoir of class 1 integrons, mainly in bacteria that may be associated with microbiological contamination. Eight out of nine integron bearing strains (88.8%) were identified based on 16S rRNA gene sequencing as either enteric bacteria or species that may be connected to animal and anthropogenic disturbance. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. THE PUBLIC HEALTH IMPORTANCE OF BIOFILM SLIME IN DRINKING WATER PIPES: CREATING HIDEOUTS FOR THE PATHOGENIC UNDERWORLD OF MICROBIOLOGY

    Science.gov (United States)

    Biofilms consist of many species of bacteria, protozoa, and other microbes living together on almost any type of moist surface. Within drinking water distribution systems, biofilms grow readily on the inner walls of pipes, even in the presence of chlorine disinfectants. Some mi...

  5. Sequential UV- and chlorine-based disinfection to mitigate Escherichia coli in drinking water biofilms.

    Science.gov (United States)

    Murphy, H M; Payne, S J; Gagnon, G A

    2008-04-01

    This study was designed to examine the potential downstream benefits of sequential disinfection to control the persistence of Escherichia coli under conditions relevant to drinking water distribution systems. Eight annular reactors (four polycarbonate and four cast iron) were setup in parallel to address various factors that could influence biofilm growth in distribution systems. Eight reactors were treated with chlorine, chlorine dioxide and monochloramine alone or in combination with UV to examine the effects on Escherichia coli growth and persistence in both the effluent and biofilm. In general, UV-treated systems in combination with chlorine or chlorine dioxide and monochloramine achieved greater log reductions in both effluent and biofilm than systems treated with chlorine-based disinfectants alone. However, during UV-low chlorine disinfection, E. coli was found to persist at low levels, suggesting that the UV treatment had instigated an adaptive mutation. During UV-chlorine-dioxide treatment, the E. coli that was initially below the detection limit reappeared during a low level of disinfection (0.2 mg/L) in the cast iron systems. Chloramine was shown to be effective in disinfecting suspended E. coli in the effluent but was unable to reduce biofilm counts to below the detection limit. Issues such as repair mechanism of E. coli and nitrification could help explain some of these aberrations. Improved understanding of the ability of chlorine-based disinfectant in combination with UV to provide sufficient disinfection will ultimately effect in improved management and safety of drinking water.

  6. Interaction of legionella pneumophila and helicobacter pylori with bacterial species isolated from drinking water biofilms

    Directory of Open Access Journals (Sweden)

    Azevedo Nuno F

    2011-03-01

    Full Text Available Abstract Background It is well established that Legionella pneumophila is a waterborne pathogen; by contrast, the mode of Helicobacter pylori transmission remains unknown but water seems to play an important role. This work aims to study the influence of five microorganisms isolated from drinking water biofilms on the survival and integration of both of these pathogens into biofilms. Results Firstly, both pathogens were studied for auto- and co-aggregation with the species isolated from drinking water; subsequently the formation of mono and dual-species biofilms by L. pneumophila or H. pylori with the same microorganisms was investigated. Neither auto- nor co-aggregation was observed between the microorganisms tested. For biofilm studies, sessile cells were quantified in terms of total cells by SYTO 9 staining, viable L. pneumophila or H. pylori cells were quantified using 16 S rRNA-specific peptide nucleic acid (PNA probes and cultivable cells by standard culture techniques. Acidovorax sp. and Sphingomonas sp. appeared to have an antagonistic effect on L. pneumophila cultivability but not on the viability (as assessed by rRNA content using the PNA probe, possibly leading to the formation of viable but noncultivable (VBNC cells, whereas Mycobacterium chelonae increased the cultivability of this pathogen. The results obtained for H. pylori showed that M. chelonae and Sphingomonas sp. help this pathogen to maintain cultivability for at least 24 hours. Conclusions It appears that M. chelonae may have an important role in the survival of both pathogens in drinking water. This work also suggests that the presence of some microorganisms can decrease the cultivability of L. pneumophila but not the viability which indicates that the presence of autochthonous microorganisms can lead to misleading results when the safety of water is assessed by cultivable methods alone.

  7. Comparison of biofilm ecology supporting growth of individual Naegleria species in a drinking water distribution system.

    Science.gov (United States)

    Puzon, Geoffrey J; Wylie, Jason T; Walsh, Tom; Braun, Kalan; Morgan, Matthew J

    2017-04-01

    Free-living amoebae (FLA) are common components of microbial communities in drinking water distribution systems (DWDS). FLA are of clinical importance both as pathogens and as reservoirs for bacterial pathogens, so identifying the conditions promoting amoebae colonisation of DWDSs is an important public health concern for water utilities. We used high-throughput amplicon sequencing to compare eukaryotic and bacterial communities associated with DWDS biofilms supporting distinct FLA species (Naegleria fowleri, N. lovaniensis or Vermamoeba sp.) at sites with similar physical/chemical conditions. Eukaryote and bacterial communities were characteristics of different FLA species presence, and biofilms supporting Naegleria growth had higher bacterial richness and higher abundance of Proteobacteria, Bacteroidetes (bacteria), Nematoda and Rotifera (eukaryota). The eukaryotic community in the biofilms had the greatest difference in relation to the presence of N. fowleri, while the bacterial community identified individual bacterial families associated with the presence of different Naegleria species. Our results demonstrate that ecogenomics data provide a powerful tool for studying the microbial and meiobiotal content of biofilms, and, in these samples can effectively discriminate biofilm communities supporting pathogenic N. fowleri. The identification of microbial species associated with N. fowleri could further be used in the management and control of N. fowleri in DWDS. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Influence of biofilms on iron and manganese deposition in drinking water distribution systems.

    Science.gov (United States)

    Ginige, Maneesha P; Wylie, Jason; Plumb, Jason

    2011-02-01

    biofilms due to cell death or flow dynamics could release the entrapped Fe and Mn into the bulk water, which could lead to a discoloured water event. Hence, managing biofilm growth on drinking water pipelines should be considered by water utilities to minimize accumulation of Fe and Mn in distribution networks.

  9. Changes in Biofilm Community Structure Associated with Monochloramine-treated Drinking Water Biofilms

    Science.gov (United States)

    Monochloramine is increasingly used as a drinking water disinfectant because it forms lower levels of traditional disinfectant by-products compared to free-chlorine disinfection treatment. The use of monochloramine has been shown to increase ammonia-oxidizing bacteria and the pr...

  10. Effect of temperature and pipe material on biofilm formation and survival of Escherichia coli in used drinking water pipes

    DEFF Research Database (Denmark)

    Silhan, J.; Corfitzen, Charlotte B.; Albrechtsen, Hans-Jørgen

    2006-01-01

    Segments of used drinking water pipes of galvanised steel (GS), cross-linked polyethylene (PEX), copper pipes (Cu) or new medium-density polyethylene (PE) were investigated for the formation of biofilm and survival of E coli in biofilm and in the water phase. Pipes were filled with water and incu...... survived longer at both temperatures in the glass control bottles than in the drinking water pipes. Despite the obvious biofilm formation, E coli was not detected in the biofilm at any of the investigated surfaces.......Segments of used drinking water pipes of galvanised steel (GS), cross-linked polyethylene (PEX), copper pipes (Cu) or new medium-density polyethylene (PE) were investigated for the formation of biofilm and survival of E coli in biofilm and in the water phase. Pipes were filled with water...... confirmed the general trends observed by HPC. Higher temperature was seen to be an important factor reducing E coli survival in the water phase in drinking water pipes. At 1 VC E coli survived more than 4 d in GS and Cu pipes and 8 d in PE-pipes, but was not detected after 48 h at 35 degrees C. The E coli...

  11. Community shift of biofilms developed in a full-scale drinking water distribution system switching from different water sources.

    Science.gov (United States)

    Li, Weiying; Wang, Feng; Zhang, Junpeng; Qiao, Yu; Xu, Chen; Liu, Yao; Qian, Lin; Li, Wenming; Dong, Bingzhi

    2016-02-15

    The bacterial community of biofilms in drinking water distribution systems (DWDS) with various water sources has been rarely reported. In this research, biofilms were sampled at three points (A, B, and C) during the river water source phase (phase I), the interim period (phase II) and the reservoir water source phase (phase III), and the biofilm community was determined using the 454-pyrosequencing method. Results showed that microbial diversity declined in phase II but increased in phase III. The primary phylum was Proteobacteria during three phases, while the dominant class at points A and B was Betaproteobacteria (>49%) during all phases, but that changed to Holophagae in phase II (62.7%) and Actinobacteria in phase III (35.6%) for point C, which was closely related to its water quality. More remarkable community shift was found at the genus level. In addition, analysis results showed that water quality could significantly affect microbial diversity together, while the nutrient composition (e.g. C/N ration) of the water environment might determine the microbial community. Furthermore, Mycobacterium spp. and Pseudomonas spp. were detected in the biofilm, which should give rise to attention. This study revealed that water source switching produced substantial impact on the biofilm community. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Core-satellite populations and seasonality of water meter biofilms in a metropolitan drinking water distribution system

    KAUST Repository

    Ling, Fangqiong

    2015-08-07

    © 2015 International Society for Microbial Ecology Drinking water distribution systems (DWDSs) harbor the microorganisms in biofilms and suspended communities, yet the diversity and spatiotemporal distribution have been studied mainly in the suspended communities. This study examined the diversity of biofilms in an urban DWDS, its relationship with suspended communities and its dynamics. The studied DWDS in Urbana, Illinois received conventionally treated and disinfected water sourced from the groundwater. Over a 2-year span, biomass were sampled from household water meters (n=213) and tap water (n=20) to represent biofilm and suspended communities, respectively. A positive correlation between operational taxonomic unit (OTU) abundance and occupancy was observed. Examined under a ‘core-satellite’ model, the biofilm community comprised 31 core populations that encompassed 76.7% of total 16 S rRNA gene pyrosequences. The biofilm communities shared with the suspended community highly abundant and prevalent OTUs, which related to methano-/methylotrophs (i.e., Methylophilaceae and Methylococcaceae) and aerobic heterotrophs (Sphingomonadaceae and Comamonadaceae), yet differed by specific core populations and lower diversity and evenness. Multivariate tests indicated seasonality as the main contributor to community structure variation. This pattern was resilient to annual change and correlated to the cyclic fluctuations of core populations. The findings of a distinctive biofilm community assemblage and methano-/methyltrophic primary production provide critical insights for developing more targeted water quality monitoring programs and treatment strategies for groundwater-sourced drinking water systems.The ISME Journal advance online publication, 7 August 2015; doi:10.1038/ismej.2015.136.

  13. Long-term succession of structure and diversity of a biofilm formed in a model drinking water distribution system

    DEFF Research Database (Denmark)

    Martiny, A.C.; Jørgensen, T.M.; Albrechtsen, Hans-Jørgen

    2003-01-01

    In this study, we examined the long-term development of the overall structural morphology and community composition of a biofilm formed in a model drinking water distribution system with biofilms from 1 day to 3 years old. Visualization and subsequent quantification showed how the biofilm developed...... length polymorphisms showed a correlation between the population profile and the age of the sample, separating the samples into young (1 to 94 days) and old (571 to 1,093 days) biofilms, whereas a limited spatial variation in the biofilm was observed. A more detailed analysis with cloning and sequencing......% of the community by day 256, and which resulted in a reduction in the overall richness. After 500 days, the biofilm entered a stable population state, which was characterized by a greater richness of bacteria, including Nitrospira, Planctomyces, Acidobacterium, and Pseudomonas. The combination of different...

  14. Detection of Escherichia coli in biofilms from pipe samples and coupons in drinking water distribution networks.

    Science.gov (United States)

    Juhna, T; Birzniece, D; Larsson, S; Zulenkovs, D; Sharipo, A; Azevedo, N F; Ménard-Szczebara, F; Castagnet, S; Féliers, C; Keevil, C W

    2007-11-01

    Fluorescence in situ hybridization (FISH) was used for direct detection of Escherichia coli on pipe surfaces and coupons in drinking water distribution networks. Old cast iron main pipes were removed from water distribution networks in France, England, Portugal, and Latvia, and E. coli was analyzed in the biofilm. In addition, 44 flat coupons made of cast iron, polyvinyl chloride, or stainless steel were placed into and continuously exposed to water on 15 locations of 6 distribution networks in France and Latvia and examined after 1 to 6 months exposure to the drinking water. In order to increase the signal intensity, a peptide nucleic acid (PNA) 15-mer probe was used in the FISH screening for the presence or absence of E. coli on the surface of pipes and coupons, thus reducing occasional problems of autofluorescence and low fluorescence of the labeled bacteria. For comparison, cells were removed from the surfaces and examined with culture-based or enzymatic (detection of beta-d-glucuronidase) methods. An additional verification was made by using PCR. Culture method indicated presence of E. coli in one of five pipes, whereas all pipes were positive with the FISH methods. E. coli was detected in 56% of the coupons using PNA FISH, but no E. coli was detected using culture or enzymatic methods. PCR analyses confirmed the presence of E. coli in samples that were negative according to culture-based and enzymatic methods. The viability of E. coli cells in the samples was demonstrated by the cell elongation after resuscitation in low-nutrient medium supplemented with pipemidic acid, suggesting that the cells were present in an active but nonculturable state, unable to grow on agar media. E. coli contributed to ca. 0.001 to 0.1% of the total bacterial number in the samples. The presence and number of E. coli did not correlate with any of physical and/or chemical characteristic of the drinking water (e.g., temperature, chlorine, or biodegradable organic matter concentration

  15. Biofilm structures (EPS and bacterial communities) in drinking water distribution systems are conditioned by hydraulics and influence discolouration.

    Science.gov (United States)

    Fish, K; Osborn, A M; Boxall, J B

    2017-03-27

    High-quality drinking water from treatment works is degraded during transport to customer taps through the Drinking Water Distribution System (DWDS). Interactions occurring at the pipe wall-water interface are central to this degradation and are often dominated by complex microbial biofilms that are not well understood. This study uses novel application of confocal microscopy techniques to quantify the composition of extracellular polymeric substances (EPS) and cells of DWDS biofilms together with concurrent evaluation of the bacterial community. An internationally unique, full-scale, experimental DWDS facility was used to investigate the impact of three different hydraulic patterns upon biofilms and subsequently assess their response to increases in shear stress, linking biofilms to water quality impacts such as discolouration. Greater flow variation during growth was associated with increased cell quantity but was inversely related to EPS-to-cell volume ratios and bacterial diversity. Discolouration was caused and EPS was mobilised during flushing of all conditions. Ultimately, biofilms developed under low-varied flow conditions had lowest amounts of biomass, the greatest EPS volumes per cell and the lowest discolouration response. This research shows that the interactions between hydraulics and biofilm physical and community structures are complex but critical to managing biofilms within ageing DWDS infrastructure to limit water quality degradation and protect public health.

  16. Formation of biofilms in drinking water distribution networks, a case study in two cities in Finland and Latvia.

    Science.gov (United States)

    Lehtola, Markku J; Juhna, Tālis; Miettinen, Ilkka T; Vartiainen, Terttu; Martikainen, Pertti J

    2004-12-01

    The formation of biofilms in drinking water distribution networks is a significant technical, aesthetic and hygienic problem. In this study, the effects of assimilable organic carbon, microbially available phosphorus (MAP), residual chlorine, temperature and corrosion products on the formation of biofilms were studied in two full-scale water supply systems in Finland and Latvia. Biofilm collectors consisting of polyvinyl chloride pipes were installed in several waterworks and distribution networks, which were supplied with chemically precipitated surface waters and groundwater from different sources. During a 1-year study, the biofilm density was measured by heterotrophic plate counts on R2A-agar, acridine orange direct counting and ATP-analyses. A moderate level of residual chlorine decreased biofilm density, whereas an increase of MAP in water and accumulated cast iron corrosion products significantly increased biofilm density. This work confirms, in a full-scale distribution system in Finland and Latvia, our earlier in vitro finding that biofilm formation is affected by the availability of phosphorus in drinking water.

  17. Sulfate Reducing Bacteria and Mycobacteria Dominate the Biofilm Communities in a Chloraminated Drinking Water Distribution System.

    Science.gov (United States)

    Gomez-Smith, C Kimloi; LaPara, Timothy M; Hozalski, Raymond M

    2015-07-21

    The quantity and composition of bacterial biofilms growing on 10 water mains from a full-scale chloraminated water distribution system were analyzed using real-time PCR targeting the 16S rRNA gene and next-generation, high-throughput Illumina sequencing. Water mains with corrosion tubercles supported the greatest amount of bacterial biomass (n = 25; geometric mean = 2.5 × 10(7) copies cm(-2)), which was significantly higher (P = 0.04) than cement-lined cast-iron mains (n = 6; geometric mean = 2.0 × 10(6) copies cm(-2)). Despite spatial variation of community composition and bacterial abundance in water main biofilms, the communities on the interior main surfaces were surprisingly similar, containing a core group of operational taxonomic units (OTUs) assigned to only 17 different genera. Bacteria from the genus Mycobacterium dominated all communities at the main wall-bulk water interface (25-78% of the community), regardless of main age, estimated water age, main material, and the presence of corrosion products. Further sequencing of the mycobacterial heat shock protein gene (hsp65) provided species-level taxonomic resolution of mycobacteria. The two dominant Mycobacteria present, M. frederiksbergense (arithmetic mean = 85.7% of hsp65 sequences) and M. aurum (arithmetic mean = 6.5% of hsp65 sequences), are generally considered to be nonpathogenic. Two opportunistic pathogens, however, were detected at low numbers: M. hemophilum (arithmetic mean = 1.5% of hsp65 sequences) and M. abscessus (arithmetic mean = 0.006% of hsp65 sequences). Sulfate-reducing bacteria from the genus Desulfovibrio, which have been implicated in microbially influenced corrosion, dominated all communities located underneath corrosion tubercules (arithmetic mean = 67.5% of the community). This research provides novel insights into the quantity and composition of biofilms in full-scale drinking water distribution systems, which is critical for assessing the risks to public health and to the

  18. Manganese-oxidizing and -reducing microorganisms isolated from biofilms in chlorinated drinking water systems.

    Science.gov (United States)

    Cerrato, José M; Falkinham, Joseph O; Dietrich, Andrea M; Knocke, William R; McKinney, Chad W; Pruden, Amy

    2010-07-01

    The interaction of chemical, physical and biological factors that affect the fate, transport and redox cycling of manganese in engineered drinking water systems is not clearly understood. This research investigated the presence of Mn-oxidizing and -reducing bacteria in conventional water treatment plants exposed to different levels of chlorine. Mn(II)-oxidizing and Mn(IV)-reducing bacteria, principally Bacillus spp., were isolated from biofilm samples recovered from four separate drinking water systems. Rates of Mn-oxidation and -reduction for selected individual isolates were represented by pseudo-first-order kinetics. Pseudo-first-order rate constants were obtained for Mn-oxidation (range: 0.106-0.659 days(-1)), aerobic Mn-reduction (range: 0.036-0.152 days(-1)), and anaerobic Mn-reduction (range: 0.024-0.052 days(-1)). The results indicate that microbial-catalyzed Mn-oxidation and -reduction (aerobic and anaerobic) can take place simultaneously in aqueous environments exposed to considerable oxygen and chlorine levels and thus affect Mn-release and -deposition in drinking water systems. This has important implications for Mn-management strategies, which typically assume Mn-reduction is not possible in the presence of chlorine and oxidizing conditions. Copyright 2010 Elsevier Ltd. All rights reserved.

  19. The effects of metabolite molecules produced by drinking water-isolated bacteria on their single and multispecies biofilms.

    Science.gov (United States)

    Simões, Lúcia Chaves; Simões, Manuel; Vieira, Maria João

    2011-08-01

    The elucidation of the mechanisms by which diverse species survive and interact in drinking water (DW) biofilm communities may allow the identification of new biofilm control strategies. The purpose of the present study was to investigate the effects of metabolite molecules produced by bacteria isolated from DW on biofilm formation. Six opportunistic bacteria, viz. Acinetobacter calcoaceticus, Burkholderia cepacia, Methylobacterium sp., Mycobacterium mucogenicum, Sphingomonas capsulata and Staphylococcus sp. isolated from a drinking water distribution systems (DWDS) were used to form single and multispecies biofilms in the presence and absence of crude cell-free supernatants produced by the partner bacteria. Biofilms were characterized in terms of mass and metabolic activity. Additionally, several physiological aspects regulating interspecies interactions (sessile growth rates, antimicrobial activity of cell-free supernatants, and production of iron chelators) were studied to identify bacterial species with biocontrol potential in DWDS. Biofilms of Methylobacterium sp. had the highest growth rate and M. mucogenicum biofilms the lowest. Only B. cepacia was able to produce extracellular iron-chelating molecules. A. calcoaceticus, B. cepacia, Methylobacterium sp. and M. mucogenicum biofilms were strongly inhibited by crude cell-free supernatants from the other bacteria. The crude cell-free supernatants of M. mucogenicum and S. capsulata demonstrated a high potential for inhibiting the growth of counterpart biofilms. Multispecies biofilm formation was strongly inhibited in the absence of A. calcoaceticus. Only crude cell-free supernatants produced by B. cepacia and A. calcoaceticus had no inhibitory effects on multispecies biofilm formation, while metabolite molecules of M. mucogenicum showed the most significant biocontrol potential.

  20. Experimental biofilms within drinking water treatment plant origin; evaluation of nutrient concentration and temperature influences upon their development

    Directory of Open Access Journals (Sweden)

    Anca FARKAS

    2009-11-01

    Full Text Available From the planktonic free-floating state, microorganisms pass to the solid state, the biofilm, cells being strongly attached to each other and usually to the interface. This changing in cells’ behavior induces surface colonization and complex interactions development within the biofilm. If the biofilm’s role into the natural aquatic habitats is, undoubtedly, a positive one, consisting in water self-purification, drinking water pipe networks biofouling can be responsible for a wide range of water quality and operational problems. This exploratory experiment was performed in order to investigate, in a time interval of 7 days, the influence of certain environmental factors such as nutrient concentration and temperature upon in vitro biofilm’s development, origin in the biofilm of water treatment plant. The method used for in vitro biofilm growth monitoring is the colorimetric measurement of the biomass. Descriptive analyses, including the mean value, variability, trends, correlations and graphic displays were performed. The correlation analysis shown that the biofilm development in the discussed experiment was influenced as by the origin source as by the temperature, time and nutrients concentration. The biomass increment was significantly different for the biofilms with clarifier and sand filter sites origin, grown at 22 oC, while at 8 oC, the differences were not significant from a statistical point of view. For all the dilutions, moments and temperatures considered, the biofilm’s development with clarifier origin registered was significantly higher than the biofilm with sand filter origin.

  1. Simultaneous enhancement of organics and nitrogen removal in drinking water biofilm pretreatment system with reed addition.

    Science.gov (United States)

    Feng, Li-Juan; Zhu, Liang; Yang, Qi; Yang, Guang-Feng; Xu, Jian; Xu, Xiang-Yang

    2013-02-01

    A novel drinking water biofilm pretreatment process with reed addition was established for enhancement of simultaneously organics and nitrogen removal. Results showed that nitrate removal efficiency was positively related with the influent C/N ratio, reaching to 87.8±2.8% at the C/N ratio of 4.7. However, the predicted trichloromethane (THM) levels based on total organic carbon (TOC) and UV254 were high with the increase of influent C/N ratio. Combined with the pollutants removal performance and microbial community variation, an appropriate C/N ratio via reed addition was determined at 2.2 for the continuous biofilm reactor. With adjustment of hydraulic retention time (HRT), the highest of nitrate removal efficiency (74.2±1.4%) and organics utilization efficiency (0.63 mg NO3--N mg(-1)TOC) were achieved at an optimum HRT of 18 h, with both low effluent NO3--N (0.88±0.03 mg l(-1)) and TOC (2.86±0.67 mg l(-1)).

  2. Bacterial Composition of Biofilms Collected From Two Service Areas in a Metropolitan Drinking Water Distribution System

    Science.gov (United States)

    The development and succession of bacteria were examined by 16S rRNA gene clone libraries generated from various biofilms within a metropolitan water distribution system. Biofilms were obtained from off-line devices using polycarbonate coupons from annular reactors incubated for ...

  3. Drinking Water

    Science.gov (United States)

    ... the safest water supplies in the world, but drinking water quality can vary from place to place. It ... water supplier must give you annual reports on drinking water. The reports include where your water came from ...

  4. Drinking water biofilms on copper and stainless steel exhibit specific molecular responses towards different disinfection regimes at waterworks.

    Science.gov (United States)

    Jungfer, Christina; Friedrich, Frank; Varela Villarreal, Jessica; Brändle, Katharina; Gross, Hans-Jürgen; Obst, Ursula; Schwartz, Thomas

    2013-09-01

    Biofilms growing on copper and stainless steel substrata in natural drinking water were investigated. A modular pilot-scale distribution facility was installed at four waterworks using different raw waters and disinfection regimes. Three-month-old biofilms were analysed using molecular biology and microscopy methods. High total cell numbers, low counts of actively respiring cells and low numbers of cultivable bacteria indicated the high abundance of viable but not cultivable bacteria in the biofilms. The expression of the recA SOS responsive gene was detected and underlined the presence of transcriptionally active bacteria within the biofilms. This effect was most evident after UV disinfection, UV oxidation and UV disinfection with increased turbidity at waterworks compared to chemically treated and non-disinfected systems. Furthermore, live/dead staining techniques and environmental scanning electron microscopy imaging revealed the presence of living and intact bacteria in biofilms on copper substrata. Cluster analyses of DGGE profiles demonstrated differences in the composition of biofilms on copper and steel materials.

  5. Whole-Genome Sequences of Four Strains Closely Related to Members of the Mycobacterium chelonae Group, Isolated from Biofilms in a Drinking Water Distribution System Simulator

    Science.gov (United States)

    We report the draft genome sequences of four Mycobacterium chelonae group strains from biofilms obtained after a ‘chlorine burn’ in a chloraminated drinking water distribution system simulator. These opportunistic pathogens have been detected in drinking and hospital water distr...

  6. Whole-Genome Sequences of Four Strains Closely Related to Members of the Mycobacterium chelonae Group, Isolated from Biofilms in a Drinking Water Distribution System Simulator

    Science.gov (United States)

    We report the draft genome sequences of four Mycobacterium chelonae group strains from biofilms obtained after a ‘chlorine burn’ in a chloraminated drinking water distribution system simulator. These opportunistic pathogens have been detected in drinking and hospital water distr...

  7. Effect of pipe material and low level disinfectants on biofilm development in a simulated drinking water distribution system

    Institute of Scientific and Technical Information of China (English)

    Ling-ling ZHOU; Yong-ji ZHANG; Gui-bai LI

    2009-01-01

    The efficiency of chlorine and chloramines disinfection on biofilm development in a simulated drinking water distribution system was investigated by using heterotrophic bacterial spread plate technique.The experiments were carried out with four annular reactors(ARs)with stainless steel(SS)or copper(Cu)material slides.The results showed that there were fewer bacteria attached to Cu slides without a disinfectant compared with those attached to SS slides.When the water was disinfected with chloramines,the heterotrophic plate counts(HPCs)on the biofilm attached to the Cu slides were significantly lower(by 3.46 log CFU/cm2)than those attached to the SS slides.Likewise,the biofilm HPC numbers on the Cu slides were slightly lower(by 1.19log CFU/cm2) than those on the SS slides disinfected with chlorine.In a quasi-steady state.the HPC levels on Cu slides can be reduced to 3.0 log CFU/cm2 with chlorine and to about 0.9 log CFU/cm2 with chloramines.The addition of chloramines resulted in a more efficient reduction of biofilm heterotrophic bacteria than did chlorine.We concluded that the chlorine and chloramines levels usually employed in water distribution system were not SUfficient to prevent the growth and development of microbial biofilm.The combination of copper pipe slides and chlorarnincs as the disinfectant was the most efficient combination to bring about diminished bacterial levels.

  8. Structure and microbial diversity of biofilms on different pipe materials of a model drinking water distribution systems.

    Science.gov (United States)

    Rożej, Agnieszka; Cydzik-Kwiatkowska, Agnieszka; Kowalska, Beata; Kowalski, Dariusz

    2015-01-01

    The experiment was conducted in three model drinking water distribution systems (DWDSs) made of unplasticized polyvinyl chloride (PVC), silane cross-linked polyethylene (PEX) and high density polyethylene (HDPE) pipes to which tap water was introduced. After 2 years of system operation, microbial communities in the DWDSs were characterized with scanning electron microscopy, heterotrophic plate count, and denaturing gradient gel electrophoresis. The most extensive biofilms were found in HDPE pipes where bacteria were either attached to mineral deposits or immersed in exopolymers. On PEX surfaces, bacteria did not form large aggregates; however, they were present in the highest number (1.24 × 10(7) cells cm(-2)). PVC biofilm did not contain mineral deposits but was made of single cells with a high abundance of Pseudomonas aeruginosa, which can be harmful to human health. The members of Proteobacteria and Bacteroidetes were found in all biofilms and the water phase. Sphingomonadales and Methylophilaceae bacteria were found only in PEX samples, whereas Geothrix fermentans, which can reduce Fe(III), were identified only in PEX biofilm. The DNA sequences closely related to the members of Alphaproteobacteria were the most characteristic and intense amplicons detected in the HDPE biofilm.

  9. Bacterial community radial-spatial distribution in biofilms along pipe wall in chlorinated drinking water distribution system of East China.

    Science.gov (United States)

    Liu, Jingqing; Ren, Hongxing; Ye, Xianbei; Wang, Wei; Liu, Yan; Lou, Liping; Cheng, Dongqing; He, Xiaofang; Zhou, Xiaoyan; Qiu, Shangde; Fu, Liusong; Hu, Baolan

    2017-01-01

    Biofilms in the pipe wall may lead to water quality deterioration and biological instability in drinking water distribution systems (DWDSs). In this study, bacterial community radial-spatial distribution in biofilms along the pipe wall in a chlorinated DWDS of East China was investigated. Three pipes of large diameter (300, 600, and 600 mm) were sampled in this DWDS, including a ductile cast iron pipe (DCIP) with pipe age of 11 years and two gray cast iron pipes (GCIP) with pipe ages of 17 and 19 years, and biofilms in the upper, middle, and lower parts of each pipe wall were collected. Real-time quantitative polymerase chain reaction (qPCR) and culture-based method were used to quantify bacteria. 454 pyrosequencing was used for bacterial community analysis. The results showed that the biofilm density and total solid (TS) and volatile solid (VS) contents increased gradually from the top to the bottom along the pipe wall. Microorganisms were concentrated in the upper and lower parts of the pipe wall, together accounting for more than 80 % of the total biomass in the biofilms. The bacterial communities in biofilms were significantly different in different areas of the pipe wall and had no strong interaction. Compared with the upper and lower parts of the pipe wall, the bacterial community in the middle of the pipe wall was distributed evenly and had the highest diversity. The 16S rRNA genes of various possible pathogens, including Escherichia coli, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Salmonella enterica, were detected in the biofilms, and the abundances of these possible pathogens were highest in the middle of the pipe wall among three areas. The detachment of the biofilms is the main reason for the deterioration of the water quality in DWDSs. The results of this study suggest that the biofilms in the middle of the pipe wall have highly potential risk for drinking water safety, which provides new ideas for the study of the microbial ecology in

  10. Autohydrogenotrophic denitrification of drinking water using a polyvinyl chloride hollow fiber membrane biofilm reactor.

    Science.gov (United States)

    Zhang, Yanhao; Zhong, Fohua; Xia, Siqing; Wang, Xuejiang; Li, Jixiang

    2009-10-15

    A hollow fiber membrane biofilm reactor (MBfR) using polyvinyl chloride (PVC) hollow fiber was evaluated in removing nitrate form contaminated drinking water. During a 279-day operation period, the denitrification rate increased gradually with the increase of influent nitrate loading. The denitrification rate reached a maximum value of 414.72 g N/m(3)d (1.50 g N/m(2)d) at an influent NO(3)(-)-N concentration of 10mg/L and a hydraulic residence time of 37.5 min, and the influent nitrate was completely reduced. At the same time, the effluent quality analysis showed the headspace hydrogen content (3.0%) was lower enough to preclude having an explosive air. Under the condition of the influent nitrate surface loading of 1.04 g N/m(2)d, over 90% removal efficiencies of the total nitrogen and nitrate were achieved at the hydrogen pressure above 0.04 MPa. The results of denaturing gel gradient electrophoresis (DGGE), 16S rDNA gene sequence analysis, and hierarchical cluster analysis showed that the microbial community structures in MBfR were of low diversity, simple and stable at mature stages; and the beta-Proteobacteria, including Rhodocyclus, Hydrogenophaga, and beta-Proteobacteria HTCC379, probably play an important role in autohydrogenotrophic denitrification.

  11. CHANGES IN BACTERIAL COMPOSITION OF BIOFILM IN A METROPOLITAN DRINKING WATER DISTRIBUTION SYSTEM

    Science.gov (United States)

    This study examined the development of bacterial biofilms within a metropolitan distribution system. The distribution system is fed with different source water (i.e., groundwater, GW and surface water, SW) and undergoes different treatment processes in separate facilities. The b...

  12. CHANGES IN BACTERIAL COMPOSITION OF BIOFILM IN A METROPOLITAN DRINKING WATER DISTRIBUTION SYSTEM

    Science.gov (United States)

    This study examined the development of bacterial biofilms within a metropolitan distribution system. The distribution system is fed with different source water (i.e., groundwater, GW and surface water, SW) and undergoes different treatment processes in separate facilities. The b...

  13. Exploring the Role of Coliform Bacteria in Class 1 Integron Carriage and Biofilm Formation During Drinking Water Treatment.

    Science.gov (United States)

    Farkas, Anca; Crăciunaş, Cornelia; Chiriac, Cecilia; Szekeres, Edina; Coman, Cristian; Butiuc-Keul, Anca

    2016-11-01

    This study investigates the role of coliforms in the carriage of class 1 integron and biocide resistance genes in a drinking water treatment plant and explores the relationship between the carriage of such genes and the biofouling abilities of the strain. The high incidence of class 1 integron and biocide resistance genes (33.3 % of the isolates) highlights the inherent risk of genetic contamination posed by coliform populations during drinking water treatment. The association between the presence of intI1 gene and qac gene cassettes, especially qacH, was greater in biofilm cells. In coliforms recovered from biofilms, a higher frequency of class 1 integron elements and higher diversity of genetic patterns occurred, compared to planktonic cells. The coliform isolates under the study proved to mostly carry non-classical class 1 integrons lacking the typical qacEΔ1/sul1 genes or a complete tni module, but bearing the qacH gene. No link was found between the carriage of integron genes and the biofouling degree of the strain, neither in aerobic or in anaerobic conditions. Coliform bacteria isolated from established biofilms rather adhere in oxygen depleted environments, while the colonization ability of planktonic cells is not significantly affected by oxygen availability.

  14. Reduction of Precursors of Chlorination By-products in Drinking Water Using Fluidized-bed Biofilm Reactor at Low Temperature

    Institute of Scientific and Technical Information of China (English)

    SHU-GUANG XIE; DONG-HUI WEN; DONG-WEN SHI; XIAO-YAN TANG

    2006-01-01

    Objective To investigate the reduction of chlorination by-products (CBPs) precursors using the fluidized-bed biofilm reactor (FBBR). Methods Reduction of total organic carbon (TOC), ultraviolet absorbance (UV254), trihalomethane (THM)formation potential (THMFP), haloacetic acid (HAA) formation potential (HAAFP), and ammonia in FBBR were evaluated in detail. Results The reduction of TOC or UV254 was low, on average 12.6% and 4.7%, respectively, while the reduction of THMFP and HAAFP was significant. The reduction of ammonia was 30%-40% even below 3℃, however, it could quickly rise to over 50% above 3℃. Conclusions The FBBR effectively reduces CBPs and ammonia in drinking water even at low temperature and seems to be a very promising and competitive drinking water reactor for polluted surface source waters, especially in China.

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

    Science.gov (United States)

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

    2014-09-01

    The effect of UV/Cl2 disinfection on the biofilm and corrosion of cast iron pipes in drinking water distribution system were studied using annular reactors (ARs). Passivation occurred more rapidly in the AR with UV/Cl2 than in the one with Cl2 alone, decreasing iron release for higher corrosivity of water. Based on functional gene, pyrosequencing assays and principal component analysis, UV disinfection not only reduced the required initial chlorine dose, but also enhanced denitrifying functional bacteria advantage in the biofilm of corrosion scales. The nitrate-reducing bacteria (NRB) Dechloromonas exhibited the greatest corrosion inhibition by inducing the redox cycling of iron to enhance the precipitation of iron oxides and formation of Fe3O4 in the AR with UV/Cl2, while the rhizobia Bradyrhizobium and Rhizobium, and the NRB Sphingomonas, Brucella producing siderophores had weaker corrosion-inhibition effect by capturing iron in the AR with Cl2. These results indicated that the microbial redox cycling of iron was possibly responsible for higher corrosion inhibition and lower effect of water Larson-Skold Index (LI) changes on corrosion. This finding could be applied toward the control of water quality in drinking water distribution systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. A continuous stirred hydrogen-based polyvinyl chloride membrane biofilm reactor for the treatment of nitrate contaminated drinking water.

    Science.gov (United States)

    Xia, Siqing; Zhang, YanHao; Zhong, FoHua

    2009-12-01

    A continuous stirred hydrogen-based polyvinyl chloride (PVC) membrane biofilm reactor (MBfR) was investigated to remove nitrate from the drinking water. The reactor was operated over 100 days, and the result showed that the average nitrate denitrification rate of 1.2 g NO(3)(-)-N/m(2) d and the total nitrogen (TN) removal of 95.1% were achieved with the influent nitrate concentration of 50 mg NO(3)(-)-N/L and the hydrogen pressure of 0.05 MPa. Under the same conditions, the average rate of hydrogen utilization by biofilm was 0.031 mg H(2)/cm(2) d, which was sufficient to remove 50 mg NO(3)(-)-N/L from the contaminated water with the effluent nitrate and nitrite concentrations below drinking water limit values. The average hydrogen utilization efficiency was achieved as high as 99.5%. Flux analysis demonstrated that, compared to sulfate reduction, nitrate reduction competed more strongly for hydrogen electron, and obtained more electrons in high influent nitrate loading.

  17. Characterisation of the physical composition and microbial community structure of biofilms within a model full-scale drinking water distribution system.

    Directory of Open Access Journals (Sweden)

    Katherine E Fish

    Full Text Available Within drinking water distribution systems (DWDS, microorganisms form multi-species biofilms on internal pipe surfaces. A matrix of extracellular polymeric substances (EPS is produced by the attached community and provides structure and stability for the biofilm. If the EPS adhesive strength deteriorates or is overcome by external shear forces, biofilm is mobilised into the water potentially leading to degradation of water quality. However, little is known about the EPS within DWDS biofilms or how this is influenced by community composition or environmental parameters, because of the complications in obtaining biofilm samples and the difficulties in analysing EPS. Additionally, although biofilms may contain various microbial groups, research commonly focuses solely upon bacteria. This research applies an EPS analysis method based upon fluorescent confocal laser scanning microscopy (CLSM in combination with digital image analysis (DIA, to concurrently characterize cells and EPS (carbohydrates and proteins within drinking water biofilms from a full-scale DWDS experimental pipe loop facility with representative hydraulic conditions. Application of the EPS analysis method, alongside DNA fingerprinting of bacterial, archaeal and fungal communities, was demonstrated for biofilms sampled from different positions around the pipeline, after 28 days growth within the DWDS experimental facility. The volume of EPS was 4.9 times greater than that of the cells within biofilms, with carbohydrates present as the dominant component. Additionally, the greatest proportion of EPS was located above that of the cells. Fungi and archaea were established as important components of the biofilm community, although bacteria were more diverse. Moreover, biofilms from different positions were similar with respect to community structure and the quantity, composition and three-dimensional distribution of cells and EPS, indicating that active colonisation of the pipe wall is

  18. Characterisation of the physical composition and microbial community structure of biofilms within a model full-scale drinking water distribution system.

    Science.gov (United States)

    Fish, Katherine E; Collins, Richard; Green, Nicola H; Sharpe, Rebecca L; Douterelo, Isabel; Osborn, A Mark; Boxall, Joby B

    2015-01-01

    Within drinking water distribution systems (DWDS), microorganisms form multi-species biofilms on internal pipe surfaces. A matrix of extracellular polymeric substances (EPS) is produced by the attached community and provides structure and stability for the biofilm. If the EPS adhesive strength deteriorates or is overcome by external shear forces, biofilm is mobilised into the water potentially leading to degradation of water quality. However, little is known about the EPS within DWDS biofilms or how this is influenced by community composition or environmental parameters, because of the complications in obtaining biofilm samples and the difficulties in analysing EPS. Additionally, although biofilms may contain various microbial groups, research commonly focuses solely upon bacteria. This research applies an EPS analysis method based upon fluorescent confocal laser scanning microscopy (CLSM) in combination with digital image analysis (DIA), to concurrently characterize cells and EPS (carbohydrates and proteins) within drinking water biofilms from a full-scale DWDS experimental pipe loop facility with representative hydraulic conditions. Application of the EPS analysis method, alongside DNA fingerprinting of bacterial, archaeal and fungal communities, was demonstrated for biofilms sampled from different positions around the pipeline, after 28 days growth within the DWDS experimental facility. The volume of EPS was 4.9 times greater than that of the cells within biofilms, with carbohydrates present as the dominant component. Additionally, the greatest proportion of EPS was located above that of the cells. Fungi and archaea were established as important components of the biofilm community, although bacteria were more diverse. Moreover, biofilms from different positions were similar with respect to community structure and the quantity, composition and three-dimensional distribution of cells and EPS, indicating that active colonisation of the pipe wall is an important

  19. Pyrosequencing reveals bacterial communities in unchlorinated drinking water distribution system: an integral study of bulk water, suspended solids, loose deposits, and pipe wall biofilm.

    Science.gov (United States)

    Liu, G; Bakker, G L; Li, S; Vreeburg, J H G; Verberk, J Q J C; Medema, G J; Liu, W T; Van Dijk, J C

    2014-05-20

    The current understanding of drinking water distribution system (DWDS) microbiology is limited to pipe wall biofilm and bulk water; the contributions of particle-associated bacteria (from suspended solids and loose deposits) have long been neglected. Analyzing the composition and correlation of bacterial communities from different phases helped us to locate where most of the bacteria are and understand the interactions among these phases. In the present study, the bacteria from four critical phases of an unchlorinated DWDS, including bulk water, pipe wall biofilm, suspended solids, and loose deposits, were quantified and identified by adenosine triphosphate analysis and pyrosequencing, respectively. The results showed that the bulk water bacteria (including the contribution of suspended solids) contributed less than 2% of the total bacteria. The bacteria associated with loose deposits and pipe wall biofilm that accumulated in the DWDS accounted for over 98% of the total bacteria, and the contributions of bacteria in loose deposits and pipe wall biofilm were comparable. Depending on the amount of loose deposits, its contribution can be 7-fold higher than the pipe wall biofilm. Pyrosequencing revealed relatively stable bacterial communities in bulk water, pipe wall biofilm, and suspended solids throughout the distribution system; however, the communities present in loose deposits were dependent on the amount of loose deposits locally. Bacteria within the phases of suspended solids, loose deposits, and pipe wall biofilm were similar in phylogenetic composition. The bulk water bacteria (dominated by Polaromonas spp.) were clearly different from the bacteria from the other three phases (dominated by Sphingomonas spp.). This study highlighted that the integral DWDS ecology should include contributions from all of the four phases, especially the bacteria harbored by loose deposits. The accumulation of loose deposits and the aging process create variable microenvironments

  20. Pyrosequencing Reveals Bacterial Communities in Unchlorinated Drinking Water Distribution System: An Integral Study of Bulk Water, Suspended Solids, Loose Deposits, and Pipe Wall Biofilm

    KAUST Repository

    Liu, G.

    2014-05-20

    The current understanding of drinking water distribution system (DWDS) microbiology is limited to pipe wall biofilm and bulk water; the contributions of particle-associated bacteria (from suspended solids and loose deposits) have long been neglected. Analyzing the composition and correlation of bacterial communities from different phases helped us to locate where most of the bacteria are and understand the interactions among these phases. In the present study, the bacteria from four critical phases of an unchlorinated DWDS, including bulk water, pipe wall biofilm, suspended solids, and loose deposits, were quantified and identified by adenosine triphosphate analysis and pyrosequencing, respectively. The results showed that the bulk water bacteria (including the contribution of suspended solids) contributed less than 2% of the total bacteria. The bacteria associated with loose deposits and pipe wall biofilm that accumulated in the DWDS accounted for over 98% of the total bacteria, and the contributions of bacteria in loose deposits and pipe wall biofilm were comparable. Depending on the amount of loose deposits, its contribution can be 7-fold higher than the pipe wall biofilm. Pyrosequencing revealed relatively stable bacterial communities in bulk water, pipe wall biofilm, and suspended solids throughout the distribution system; however, the communities present in loose deposits were dependent on the amount of loose deposits locally. Bacteria within the phases of suspended solids, loose deposits, and pipe wall biofilm were similar in phylogenetic composition. The bulk water bacteria (dominated by Polaromonas spp.) were clearly different from the bacteria from the other three phases (dominated by Sphingomonas spp.). This study highlighted that the integral DWDS ecology should include contributions from all of the four phases, especially the bacteria harbored by loose deposits. The accumulation of loose deposits and the aging process create variable microenvironments

  1. Development of an Escherichia coli K12-specific quantitative polymerase chain reaction assay and DNA isolation suited to biofilms associated with iron drinking water pipe corrosion products

    Science.gov (United States)

    Escherichia coli is one of the most commonly used fecal indicator organisms for drinking water and groundwater systems. In order to understand various biogeochemical and biophysical factors affecting its interactions with biofilms, E. coli K12 was chosen as a model organism. A Ta...

  2. Persistence of non-native spore forming bacteria in drinking water biofilm and evaluation of decontamination methods.

    Science.gov (United States)

    Shane, William T; Szabo, Jeffrey G; Bishop, Paul L

    2011-01-01

    Persistence of Bacillus globigii spores, a surrogate for Bacillus anthracis, was studied on biofouled concrete-lined slides in drinking water using biofilm annular reactors. Reactors were inoculated with B. globigii spores and persistence was monitored in the bulk and biofilm phases, first in dechlorinated water and later with free chlorine concentrations of 1 and 5 mg/L. In the dechlorinated study, a steady state population of spores developed on the slides. The addition of free chlorine at 5 mg/L decreased the adhered spore density by 2-logs within 4 hours and spores were not detected after 67 and 49 hours in the presence of 1 and 5 mg/L free chlorine, respectively. This suggests that adhered spores can persist in non-chlorinated conditions, but detach and/or are inactivated upon addition of free chlorine. When injected into a chlorinated reactor, adhered spore density continually decreased and spores were either undetectable or unquantifiable by 48 hours for both 1 and 5 mg/L chlorine concentrations. Results from these experiments suggest that the presence of a free chlorine residual limits adherence of viable spores to biofouled concrete-lined pipe walls by inactivating spores before they have attached. Both free chlorine concentrations (1 and 5 mg/L) were equally effective at inactivating spores in terms of log reduction, but the higher concentrations yielded faster rates of log reduction.

  3. An ignored and potential source of taste and odor (T&O) issues-biofilms in drinking water distribution system (DWDS).

    Science.gov (United States)

    Zhou, Xinyan; Zhang, Kejia; Zhang, Tuqiao; Li, Cong; Mao, Xinwei

    2017-05-01

    It is important for water utilities to provide esthetically acceptable drinking water to the public, because our consumers always initially judge the quality of the tap water by its color, taste, and odor (T&O). Microorganisms in drinking water contribute largely to T&O production and drinking water distribution systems (DWDS) are known to harbor biofilms and microorganisms in bulk water, even in the presence of a disinfectant. These microbes include T&O-causing bacteria, fungi, and algae, which may lead to unwanted effects on the organoleptic quality of distributed water. Importantly, the understanding of types of these microbes and their T&O compound-producing mechanisms is needed to prevent T&O formation during drinking water distribution. Additionally, new disinfection strategies and operation methods of DWDS are also needed for better control of T&O problems in drinking water. This review covers: (1) the microbial species which can produce T&O compounds in DWDS; (2) typical T&O compounds in DWDS and their formation mechanisms by microorganisms; (3) several common factors in DWDS which can influence the growth and T&O generation of microbes; and (4) several strategies to control biofilm and T&O compound formation in DWDS. At the end of this review, recommendations were given based on the conclusion of this review.

  4. High efficiency removal of 2-chlorophenol from drinking water by a hydrogen-based polyvinyl chloride membrane biofilm reactor.

    Science.gov (United States)

    Xia, Siqing; Zhang, Zhiqiang; Zhong, Fohua; Zhang, Jiao

    2011-02-28

    A continuously stirred hydrogen-based membrane biofilm reactor (MBfR) with polyvinyl chloride (PVC) hollow fiber membrane was investigated for removing 2-chlorophenol (2-CP) from contaminated drinking water. The bioreactor startup was achieved by acclimating the microorganisms from a denitrifying and sulfate-reducing MBfR to the drinking water contaminated by 2-CP. The effects of some major factors, including 2-CP loading, H(2) pressure, nitrate loading, and sulfate loading, on the removal of 2-CP by the MBfR were systematically investigated. Although the effluent 2-CP concentration increased with its increasing influent loading, the removing efficiency of 2-CP by the MBfR could be up to 94.7% under a high influent loading (25.71 mg/L d). The removing efficiency of 2-CP by the MBfR could be improved by higher H(2) pressure, and lower influent nitrate concentration and sulfate concentration. A high H(2) pressure can assure enough available H(2) as the electron donor for 2-CP degradation. The competition in the electron donor made nitrate and sulfate inhibit the degradation of 2-CP in the MBfR. The electron flux analyses indicated that the degradation of 2-CP only accounted for a small part of electron flux, and the autohydrogenotrophic bacteria in the MBfR were highly efficient for the 2-CP removal.

  5. Molecular analysis of long-term biofilm formation on PVC and cast iron surfaces in drinking water distribution system.

    Science.gov (United States)

    Liu, Ruyin; Zhu, Junge; Yu, Zhisheng; Joshi, DevRaj; Zhang, Hongxun; Lin, Wenfang; Yang, Min

    2014-04-01

    To understand the impacts of different plumbing materials on long-term biofilm formation in water supply system, we analyzed microbial community compositions in the bulk water and biofilms on faucets with two different materials-polyvinyl chloride (PVC) and cast iron, which have been frequently used for more than10 years. Pyrosequencing was employed to describe both bacterial and eukaryotic microbial compositions. Bacterial communities in the bulk water and biofilm samples were significantly different from each other. Specific bacterial populations colonized on the surface of different materials. Hyphomicrobia and corrosion associated bacteria, such as Acidithiobacillus spp., Aquabacterium spp., Limnobacter thiooxidans, and Thiocapsa spp., were the most dominant bacteria identified in the PVC and cast iron biofilms, respectively, suggesting that bacterial colonization on the material surfaces was selective. Mycobacteria and Legionella spp. were common potential pathogenic bacteria occurred in the biofilm samples, but their abundance was different in the two biofilm bacterial communities. In contrast, the biofilm samples showed more similar eukaryotic communities than the bulk water. Notably, potential pathogenic fungi, i.e., Aspergillus spp. and Candida parapsilosis, occurred in similar abundance in both biofilms. These results indicated that microbial community, especially bacterial composition was remarkably affected by the different pipe materials (PVC and cast iron).

  6. Biofilm Community Dynamics in Bench-Scale Annular Reactors Simulating Arrestment of Chloraminated Drinking Water Nitrification

    Science.gov (United States)

    Annular reactors (ARs) were used to study biofilm community succession and provide an ecological insight during nitrification arrestment through simultaneously increasing monochloramine (NH2Cl) and chlorine to nitrogen mass ratios, resulting in four operational periods (I to IV)....

  7. 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 steel iron. All the results interpreted that PVC would be a potentially suitable material for use as tap component in drinking water distribution system.

  8. Microbial diversities (16S and 18S rDNA gene pyrosequencing) and environmental pathogens within drinking water biofilms grown on the common premise plumbing materials unplasticized polyvinylchloride and copper

    Science.gov (United States)

    Drinking water (DW) biofilm communities influence the survival of opportunistic pathogens, e.g. Legionella pneumophila, via parasitization of free-living amoebae such as Acanthamoebae. Yet knowledge about the microbial composition of DW biofilms developed on common in-premise pl...

  9. CHARACTERIZING THE EFFECT OF CHLORINE AND CHLORAMINES ON THE FORMATION OF BIOFILM IN A SIMULATED DRINKING WATER DISTRIBUTION SYSTEM

    Science.gov (United States)

    Drinking wate treatment in the US has played a major role in protecting public health through the reduction of wateborne disease. However, carcinogenic and toxic contaminants continue to threaten the quality of surface and ground water in the US. The passage of the Safe Drinking ...

  10. Pyrosequencing analysis of bacterial communities in biofilms from different pipe materials in a city drinking water distribution system of East China.

    Science.gov (United States)

    Ren, Hongxing; Wang, Wei; Liu, Yan; Liu, Shuai; Lou, Liping; Cheng, Dongqing; He, Xiaofang; Zhou, Xiaoyan; Qiu, Shangde; Fu, Liusong; Liu, Jingqing; Hu, Baolan

    2015-12-01

    Biofilms in drinking water distribution systems (DWDSs) could cause several types of problems, such as the deterioration of water quality, corrosion of pipe walls, and potential proliferation of opportunistic pathogens. In this study, ten biofilm samples from different pipe materials, including ductile cast iron pipe (DCIP), gray cast iron pipe (GCIP), galvanized steel pipe (GSP), stainless steel clad pipe (SSCP), and polyvinyl chloride (PVC), were collected from an actual DWDS to investigate the effect of pipe material on bacterial community. Real-time quantitative polymerase chain reaction (qPCR) and culture-based method were used to quantify bacteria. 454 pyrosequencing was used for bacterial community analysis. The results showed that the numbers of total bacteria and culturable heterotrophic bacteria from iron pipes were higher than that in PVC, while the numbers of Shigella and vibrios were low in biofilms from iron pipes. Bacterial community analysis showed that Hyphomicrobium or Desulfovibrio were the predominant microorganism in iron pipes, whereas Sphingomonas or Pseudomonas were dominant in other types of pipe. This study revealed differences in bacterial communities in biofilms among different pipe materials, and the results were useful for pipeline material selection in DWDSs.

  11. Evaluation of susceptibility of polymer and rubber materials intended into contact with drinking water on biofilm formation

    Science.gov (United States)

    Szczotko, Maciej; Stankiewicz, Agnieszka; Jamsheer-Bratkowska, Małgorzata

    Plumbing materials in water distribution networks and indoor installations are constantly evolving. The application of new, more economical solutions with plastic materials eliminates the corrosion problems, however, do not fully protect the consumer against secondary microbial contamination of water intended for human consumption caused by the presence of a biofilm on the inner surface of materials applied. National Institute of Public Health - National Institute of Hygiene conducts research aimed at a comprehensive assessment of this type of materials, resulting their further marketing authorization in Poland. Evaluation and comparison of polymer and rubber materials intended to contact with water for the susceptibility to biofilm formation. Plastic materials (polyethylene, polypropylene, polyvinyl chloride) and rubber compounds (EPDM, NBR), from different manufacturers were evaluated. The study was carried out on 37 samples, which were divided into groups according to the material of which they were made. The testing was conducted according to the method based on conditions of dynamic flow of tap water. The level of bioluminescence in swabs taken from the surface of the tested materials was investigated with a luminometer. Evaluation of plastic materials does not show major objections in terms of hygienic assessment. All materials met the evaluation criteria established for methodology used. In case of rubber compounds, a substantial part clearly exceeded the limit values, which resulted in their negative assessment and elimination of these materials from domestic market. High susceptibility to the formation of biofilm in the group of products made of rubber compounds has been demonstrated. Examined plastic materials, except for several cases, do not revealed susceptibility to biofilm formation, but application of plastics for distribution of water intended for human consumption does not fully protect water from secondary, microbiological contamination. Complete

  12. Formation and elimination of the biofilm in drinking water distribution system; Formacion y eliminacion de biofilm en las redes de distribucion de agua potable

    Energy Technology Data Exchange (ETDEWEB)

    Ubeda, J.; Briones, A. [Universidad de Castilla-La Mancha (Spain); Lopez, E. [Aquagest, S. A. Ciudad Real (Spain)

    2000-07-01

    The water distribution system is a proper medium for the developing of microorganisms. This growth together to the excretion of organic polymers promote the formation of the bio films. Its develop on the surface of the distribution systems depend of different factors, underlying the composition of the pipes. The formation of the biofilm cause a deterioration of the organoleptic and micro biologic quality of water since it behaves as a protector barrier of the pathogenic bacteria that have outlived the water treatment process. A biofilm can be visualized using microscopic techniques, even though at the present genetic and immuno fluorescent techniques are employed. The cleaning and disinfection are used for its elimination: when the chloride is used, a great residual concentration is needed. (Author) 22 refs.

  13. Microbial diversities (16S and 18S rRNA gene pyrosequencing) and environmental pathogens within drinking water biofilms grown on the common premise plumbing materials unplasticized polyvinylchloride and copper.

    Science.gov (United States)

    Buse, Helen Y; Lu, Jingrang; Lu, Xinxin; Mou, Xiaozhen; Ashbolt, Nicholas J

    2014-05-01

    Drinking water (DW) biofilm communities influence the survival of opportunistic pathogens, yet knowledge about the microbial composition of DW biofilms developed on common in-premise plumbing material is limited. Utilizing 16S and 18S rRNA gene pyrosequencing, this study characterized the microbial community structure within DW biofilms established on unplasticized polyvinyl chloride (uPVC) and copper (Cu) surfaces and the impact of introducing Legionella pneumophila (Lp) and Acanthamoeba polyphaga. Mature (> 1 year old) biofilms were developed before inoculation with sterilized DW (control, Con), Lp, or Lp and A. polyphaga (LpAp). Comparison of uPVC and Cu biofilms indicated significant differences between bacterial (P = 0.001) and eukaryotic (P 0.05) but did affect eukaryotic members (uPVC, P < 0.01; Cu, P = 0.001). Thus, established DW biofilms host complex communities that may vary based on substratum matrix and maintain consistent bacterial communities despite introduction of Lp, an environmental pathogen.

  14. Impact of drinking water conditions and copper materials on downstream biofilm microbial communities and legionella pneumophila colonization

    Science.gov (United States)

    Legionella pneumophila, the medically important species within the genus Legionella, is a concern in engineered water systems. Its ability to amplify within free-living amoebae is well documented, but its interactions/ecology within the microbial community of drinking water biofi...

  15. Evaluation of the Inhibition of Culturable Enterococcus faecium, Escherichia coli, or Aeromonas hydrophilia by an Existing Drinking Water Biofilm

    Science.gov (United States)

    Experiments were conducted to determine if an existing biofilm could act as a inhibitor to introduced microorganisms, preventing them from being incorporated into the existing biofilm or forming a biofilm. Biofilm sampling coupons were challenged by a solution of a single indica...

  16. Accumulation of MS2, GA, and Qβ phages on high density polyethylene (HDPE) and drinking water biofilms under flow/non-flow conditions.

    Science.gov (United States)

    Pelleïeux, Sandra; Bertrand, Isabelle; Skali-Lami, Salaheddine; Mathieu, Laurence; Francius, Grégory; Gantzer, Christophe

    2012-12-01

    Accumulation of enteric viruses on surfaces within a drinking water distribution system was investigated in a reactor using three F-specific RNA bacteriophages (MS2, GA, and Qβ) as models of human pathogenic viruses. The influence of hydrodynamic versus hydrostatic conditions and the effect of the colonization of HDPE surfaces with two-month-old biofilms were assessed for virus accumulation on surfaces. In order to work under controlled laminar conditions and to study various wall shear stresses at the same time, a new rotating disc reactor was designed. Among the wall shear rates applied in the reactor (450 to 1640 s(-1)) no significant differences were observed concerning both the total number of bacteria, which was found to be around 1.7 × 10(7) cells/cm(2) and the virus concentrations on surfaces were about 3 × 10(4), 5 × 10(5) and 3 × 10(5) eq PFU/cm(2) for MS2, GA and Qβ phages, respectively. Comparison between static versus dynamic conditions revealed that both Brownian diffusion and convective diffusion were involved in the transport of these soft colloidal particles and an increase reaching about 1 log in virus concentrations measured on surfaces appeared when hydrodynamic conditions where applied. Our results also showed the influence of the colonization by two-month-old drinking water biofilms which led to a change in the level of virus adhesion. The implication of the physico-chemical properties was also underlined since different adhesion profiles were obtained for the three bacteriophages and MS2 phage was found to be the less adherent one whatever the conditions applied. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Biological denitrification in drinking water treatment using the seaweed Gracilaria verrucosa as carbon source and biofilm carrier.

    Science.gov (United States)

    Ovez, B; Mergaert, J; Saglam, M

    2006-04-01

    Chemical and microbiological aspects were investigated with regard to biological denitrification of drinking water using the seaweed Gracilaria verrucosa as the carbon and energy substrate and as physical support for the microbial flora in semibatch, fixed-bed reactors. Complete removal of nitrate (100 mg/L) was readily achieved without accumulation of nitrite. Microbiological analysis indicated that the effluent of the reactor contained high numbers of bacteria (>10(6)/mL total count). Among the 44 bacterial strains isolated directly from the samples or isolated after enrichment at 37 degrees C, 25 different fatty acid profiles were found, indicating a complex microflora, including potential pathogens.

  18. Quality of Drinking Water

    Science.gov (United States)

    Roman, Harry T.

    2009-01-01

    The quality of drinking water has been gaining a great deal of attention lately, especially as water delivery infrastructure continues to age. Particles of various metals such as lead and copper, and other substances like radon and arsenic could be entering drinking water supplies. Spilled-on-the-ground hydrocarbon-based substances are also…

  19. Quality of Drinking Water

    Science.gov (United States)

    Roman, Harry T.

    2009-01-01

    The quality of drinking water has been gaining a great deal of attention lately, especially as water delivery infrastructure continues to age. Particles of various metals such as lead and copper, and other substances like radon and arsenic could be entering drinking water supplies. Spilled-on-the-ground hydrocarbon-based substances are also…

  20. Nitrate in drinking water

    DEFF Research Database (Denmark)

    Schullehner, Jörg; Hansen, Birgitte; Sigsgaard, Torben

    Annual nationwide exposure maps for nitrate in drinking water in Denmark from the 1970s until today will be presented based on the findings in Schullehner & Hansen (2014) and additional work on addressing the issue of private well users and estimating missing data. Drinking water supply in Denmark...... is highly decentralized and fully relying on simple treated groundwater. At the same time, Denmark has an intensive agriculture, making groundwater resources prone to nitrate pollution. Drinking water quality data covering the entire country for over 35 years are registered in the public database Jupiter....... In order to create annual maps of drinking water quality, these data had to be linked to 2,852 water supply areas, which were for the first time digitized, collected in one dataset and connected to the Jupiter database. Analyses of the drinking water quality maps showed that public water supplies...

  1. Drinking Water and Health.

    Science.gov (United States)

    National Academy of Sciences, Washington, DC.

    In response to a provision of the Safe Drinking Water Act of 1974 which called for a study that would serve as a scientific basis for revising the primary drinking water regulations that were promulgated under the Act, a study of the scientific literature was undertaken in order to assess the implications for human health of the constituents of…

  2. Drink Water, Fight Fat?

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_165714.html Drink Water, Fight Fat? When you have it in place ... HealthDay News) -- If you choose a glass of water instead of a beer or a sugar-sweetened ...

  3. Drinking Water FAQ

    Science.gov (United States)

    ... your well Who should test your well Drinking Water FAQ Frequently Asked Questions General Where does my ... CDC's Private Wells page. Top of Page Public Water Systems What type of health issues can be ...

  4. SDWISFED Drinking Water Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — SDWIS/FED is EPA's national regulatory compliance database for the drinking water program. It includes information on the nation's 160,000 public water systems and...

  5. Drinking Water Distribution Systems

    Science.gov (United States)

    Learn about an overview of drinking water distribution systems, the factors that degrade water quality in the distribution system, assessments of risk, future research about these risks, and how to reduce cross-connection control risk.

  6. Drinking Water Treatability Database (TDB)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Drinking Water Treatability Database (TDB) presents referenced information on the control of contaminants in drinking water. It allows drinking water utilities,...

  7. A new coupon design for simultaneous analysis of in situ microbial biofilm formation and community structure in drinking water distribution systems.

    Science.gov (United States)

    Deines, Peter; Sekar, Raju; Husband, P Stewart; Boxall, Joby B; Osborn, A Mark; Biggs, Catherine A

    2010-06-01

    This study presents a new coupon sampling device that can be inserted directly into the pipes within water distribution systems (WDS), maintaining representative near wall pipe flow conditions and enabling simultaneous microscopy and DNA-based analysis of biofilms formed in situ. To evaluate this sampling device, fluorescent in situ hybridization (FISH) and denaturing gradient gel electrophoresis (DGGE) analyses were used to investigate changes in biofilms on replicate coupons within a non-sterile pilot-scale WDS. FISH analysis demonstrated increases in bacterial biofilm coverage of the coupon surface over time, while the DGGE analysis showed the development of increasingly complex biofilm communities, with time-specific clustering of these communities. This coupon design offers improvements over existing biofilm sampling devices in that it enables simultaneous quantitative and qualitative compositional characterization of biofilm assemblages formed within a WDS, while importantly maintaining fully representative near wall pipe flow conditions. Hence, it provides a practical approach that can be used to capture the interactions between biofilm formation and changing abiotic conditions, boundary shear stress, and turbulent driven exchange within WDS.

  8. Drinking water and cancer.

    OpenAIRE

    Morris, R D

    1995-01-01

    Any and all chemicals generated by human activity can and will find their way into water supplies. The types and quantities of carcinogens present in drinking water at the point of consumption will differ depending on whether they result from contamination of the source water, arise as a consequence of treatment processes, or enter as the water is conveyed to the user. Source-water contaminants of concern include arsenic, asbestos, radon, agricultural chemicals, and hazardous waste. Of these,...

  9. Drinking water quality and formation of biofilms in an office building during its first year of operation, a full scale study.

    Science.gov (United States)

    Inkinen, Jenni; Kaunisto, Tuija; Pursiainen, Anna; Miettinen, Ilkka T; Kusnetsov, Jaana; Riihinen, Kalle; Keinänen-Toivola, Minna M

    2014-02-01

    Complex interactions existing between water distribution systems' materials and water can cause a reduction in water quality and unwanted changes in materials, aging or corrosion of materials and formation of biofilms on surfaces. Substances leaching from pipe materials and water fittings, as well as the microbiological quality of water and formation of biofilms were evaluated by applying a Living Lab theme i.e. a research in a real life setting using a full scale system during its first year of operation. The study site was a real office building with one part of the building lined with copper pipes, the other with cross-linked polyethylene (PEX) pipes thus enabling material comparison; also differences within the cold and hot water systems were analysed. It was found that operational conditions, such as flow conditions and temperature affected the amounts of metals leaching from the pipe network. In particular, brass components were considered to be a source of leaching; e. g. the lead concentration was highest during the first few weeks after the commissioning of the pipe network when the water was allowed to stagnate. Assimilable organic carbon (AOC) and microbially available phosphorus (MAP) were found to leach from PEX pipelines with minor effects on biomass of the biofilm. Cultivable and viable biomass (heterotrophic plate count (HPC), and adenosine triphosphate (ATP)) levels in biofilms were higher in the cold than in the hot water system whereas total microbial biomass (total cell count (DAPI)) was similar with both systems. The type of pipeline material was not found to greatly affect the microbial biomass or Alpha-, Beta- and Gammaproteobacteria profiles (16s rRNA gene copies) after the first one year of operation. Also microbiological quality of water was found to deteriorate due to stagnation.

  10. Biofilms from a Brazilian water distribution system include filamentous fungi.

    Science.gov (United States)

    Siqueira, V M; Oliveira, H M B; Santos, C; Paterson, R R M; Gusmão, N B; Lima, N

    2013-03-01

    Filamentous fungi in drinking water can block water pipes, can cause organoleptic biodeterioration, and are a source of pathogens. There are increasing reports of the involvement of the organisms in biofilms. This present study describes a sampling device that can be inserted directly into pipes within water distribution systems, allowing biofilm formation in situ. Calcofluor White M2R staining and fluorescent in situ hybridization with morphological analyses using epifluorescent microscopy were used to analyse biofilms for filamentous fungi, permitting direct observation of the fungi. DAPI (4',6-diamidino-2-phenylindole) was applied to detect bacteria. Filamentous fungi were detected in biofilms after 6 months on coupons exposed to raw water, decanted water and at the entrance of the water distribution system. Algae, yeast, and bacteria were also observed. The role of filamentous fungi requires further investigations.

  11. Drinking water quality assessment.

    Science.gov (United States)

    Aryal, J; Gautam, B; Sapkota, N

    2012-09-01

    Drinking water quality is the great public health concern because it is a major risk factor for high incidence of diarrheal diseases in Nepal. In the recent years, the prevalence rate of diarrhoea has been found the highest in Myagdi district. This study was carried out to assess the quality of drinking water from different natural sources, reservoirs and collection taps at Arthunge VDC of Myagdi district. A cross-sectional study was carried out using random sampling method in Arthunge VDC of Myagdi district from January to June,2010. 84 water samples representing natural sources, reservoirs and collection taps from the study area were collected. The physico-chemical and microbiological analysis was performed following standards technique set by APHA 1998 and statistical analysis was carried out using SPSS 11.5. The result was also compared with national and WHO guidelines. Out of 84 water samples (from natural source, reservoirs and tap water) analyzed, drinking water quality parameters (except arsenic and total coliform) of all water samples was found to be within the WHO standards and national standards.15.48% of water samples showed pH (13) higher than the WHO permissible guideline values. Similarly, 85.71% of water samples showed higher Arsenic value (72) than WHO value. Further, the statistical analysis showed no significant difference (Pwater for collection taps water samples of winter (January, 2010) and summer (June, 2010). The microbiological examination of water samples revealed the presence of total coliform in 86.90% of water samples. The results obtained from physico-chemical analysis of water samples were within national standard and WHO standards except arsenic. The study also found the coliform contamination to be the key problem with drinking water.

  12. IDENTIFICATION OF ACTIVE BACTERIAL COMMUNITIES IN A MODEL DRINKING WATER BIOFILM SYSTEM USING 16S RRNA-BASED CLONE LIBRARIES

    Science.gov (United States)

    Recent phylogenetic studies have used DNA as the target molecule for the development of environmental 16S rDNA clone libraries. As DNA may persist in the environment, DNA-based libraries cannot be used to identify metabolically active bacteria in water systems. In this study, a...

  13. 给水管网生物膜反应器及分子生物学研究方法进展%Progress on Research Methods of Biofilm Reactor and Molecular Biology in Drinking Water Distribution

    Institute of Scientific and Technical Information of China (English)

    林文芳; 余志晟; 陈曦; 张洪勋

    2012-01-01

    Microorganisms attach to the inner surface of drinking water network and form biofilms during delivery to endpoint consumers. The biofilms lead to series of water quality problem such as growth of pathogenic bacteria, undesirable color and turbidity, pipeline corrosion, which would arouse a potential health risk. Moreover the organisms are protected from disinfectant once integrated in drinking water biofilms, therefore the biofilms are always the hot and difficult research subject of drinking water distribution systems. However biofilms in the real distribution are difficult to be obtained, and their dynamic formation cannot be continuously monitored, so biofilms with model rector in labs are very important. With the development of technologies, cultivation method is not the only technique used to study the biofilms, and new research tools like modem molecular methods and microscopic image techniques are introduced, which provide a scientific and reasonable understanding of biofilras, thereby guarantee security to high quality drinking water. A comprehensive overview of several common model reactors and their working principles, advantages and disadvantages were discussed.%饮用水在经管道输送到用户的过程中,微生物附着到管网内壁生长形成生物膜.生物膜的存在会引起一系列水质问题如病原菌的生长、色度和浊度的变化、管道的腐蚀等,对人类饮用水安全构成威胁.而且生物膜对消毒剂有顽强的抗性,一旦形成就难以控制.所以生物膜一直是给水管网研究的热点和难点.但是给水管网中生物膜的实际采样研究比较困难,而且实际取样无法连续监测生物膜形成的动态变化过程,因此用反应器实验模拟研究生物膜显得尤为重要.另外,随着技术的进步,研究给水管网生物膜不仅仅局限于传统的培养方法,还出现了一些新手段如现代分子生物学技术和显微镜图像分析技术,以便更加科学、合理

  14. CERN’s Drinking Water

    CERN Multimedia

    GS Department

    CERN’s drinking water is monitored on a regular basis. A certified independent laboratory takes and analyses samples to verify that the water complies with national and European regulations for safe drinking water. Nevertheless, the system that supplies our drinking water is very old and occasionally, especially after work has been carried out on the system, the water may become cloudy or discoloured, due to traces of corrosion. For this reason, we recommend: Never use hot water from the tap for drinking or cooking. If you need hot water, then draw water from the cold water tap and heat it. Only drink or cook with cold water. Let the cold water run until it is clear before drinking or making your tea or coffee. If you have any questions about the quality of CERN’s drinking water, please contact: Jerome Espuche (GS/SEM), Serge Deleval (EN/CV) or Jonathan Gulley (DG/SCG).

  15. Water Fit to Drink.

    Science.gov (United States)

    Donovan, Edward P.

    The major objective of this module is to help students understand how water from a source such as a lake is treated to make it fit to drink. The module, consisting of five major activities and a test, is patterned after Individualized Science Instructional System (ISIS) modules. The first activity (Planning) consists of a brief introduction and a…

  16. 饮用水管网生物膜中弧菌数量影响因素研究%Effects of drinking water distribution system on Vibrio amounts in biofilm

    Institute of Scientific and Technical Information of China (English)

    史亚; 施晓峰; 张永静; 柳景青; 程东庆

    2016-01-01

    Summary With the development of modern industries,drinking water in residential area and public building were supplied by water distribution systems.The drinking water distribution system is the final step from water plants to the users,and therefore is essential to assure drinking water safety for customers.Previous studies confirmed that many bacteria in the drinking water distribution systems existed as biofilm,which could induce corrosion and scaling of the pipe walls,reduce the water quality and water-carrying capacity of the pipelines. Moreover,as the pathogens growing in the biofilms transferred in the pipelines,the risks caused by these microorganisms would increase.Vibrio species is an estuarine bacterium widely distributed in the natural aquatic environment around the world.Among the discovered 76 kinds ofVibrio species,at least 12 kinds have pathogenic effect on human,and often result in severe diarrhea and dehydration.We found the Vibrio species in our previous survey of pathogenic bacteria in biofilm,indicating that the residents were at potential risk from Vibrio species. Therefore,the effect of pipe materials,pipe ages,and pipe diameters on amount of Vibrio species in biofilm of drinking water distribution system was necessary to investigate. In this study,1 2 biofilm samples were collected from the drinking water distribution system in east China. Vibrio was isolated using thiosulfate-citrate-bile salts-sucrose(TCBS)agar medium and was identified according to their biochemical reaction characteristics using biochemical identification kit for Vibrionaceae GYZ-9V.The amounts of total bacteria were determined by a spread-plating method according to the Ministry of Health StandardExaminationMethodsforDrinkingWater(2006).Samples and their dilutions were spread on Petri dishes with nutrient agar medium.Analysis of variance (ANOVA) by a least significant difference test was used to compare Vibrio counts from different pipe materials,ages and diameters

  17. CERN’s Drinking Water

    CERN Multimedia

    GS Department

    2009-01-01

      CERN’s drinking water is monitored, with regular samples being taken and analysed by a certified independent laboratory, which checks on compliance with national and European regulations for safe drinking water. Nevertheless, the drinking water network is very old and occasionally, especially after work has been carried out on the network, the clarity and colour of the water can be adversely affected due to high levels of corrosion in suspension. Some basic recommendations should always be followed:   Never use hot water from the tap for drinking or cooking. If you need hot water, then draw water from the cold water tap before heating it. Only drink or cook with cold water. Let the cold water run until you notice that the water has become clear.   If you have questions about the quality of CERN’s drinking water, then please contact: Jerome Espuche (GS/SEM), Serge Deleval (EN/CV) or Jonathan Gulley (DG/SCG).

  18. CERN’s Drinking Water

    CERN Multimedia

    GS Department

      CERN’s drinking water is monitored, with regular samples being taken and analysed by a certified independent laboratory, which checks on compliance with national and European regulations for safe drinking water. Nevertheless, the drinking water network is very old and occasionally, especially after work has been carried out on the network, the clarity and colour of the water can be adversely affected due to high levels of corrosion in suspension. Some basic recommendations should always be followed: Never use hot water from the tap for drinking or cooking. If you need hot water, then draw water from the cold water tap before heating it. Only drink or cook with cold water. Let the cold water run until you notice that the water has become clear. If you have questions about the quality of CERN’s drinking water, then please contact: Jerome Espuche (GS/SEM), Serge Deleval (EN/CV) or Jonathan Gulley (DG/SCG).

  19. Biofilms on Hospital Shower Hoses: Characterization and Implications for Nosocomial Infections

    Science.gov (United States)

    Although the source of drinking water used in hospitals is commonly, biofilms on water pipelines are refuge to bacteria that survive different disinfection strategies. Drinking water (DW) biofilms are well known to harbor opportunistic pathogens, however, these biofilm communitie...

  20. Biofilms on Hospital Shower Hoses: Characterization and Implications for Nosocomial Infections

    Science.gov (United States)

    Although the source of drinking water used in hospitals is commonly, biofilms on water pipelines are refuge to bacteria that survive different disinfection strategies. Drinking water (DW) biofilms are well known to harbor opportunistic pathogens, however, these biofilm communitie...

  1. Pesticides in drinking water

    Directory of Open Access Journals (Sweden)

    Irena Grmek-Košnik

    2006-09-01

    Full Text Available Background: Use of pesticides deceives of indisputable advantage, however remainders of pesticides in drinking water might represent potential danger for health on foodstuffs. In European Union (EU pesticides and their relevant metabolic, degrading and reactive products, with exception for aldrin, dieldrin, heptaclor and heptaclor epoxide, should not exceed the concentration of 0.10 μg/l. At limit value 0.10 μg/l we wish to achieve null value these substances in drinking water.Methods: In years 2004 and 2005 monitoring of pesticides in drinking waters on pipes of consumers in all larger towns in state was done. Majority of pesticides were analysed by gas chromatography in combination with mass spectrometry while fluid cromatography was used primarily for badly volatile or polar and termolabile compound.Results: Results of analyses of drinking water and of ground waters for years 2004 and 2005 showed that levels of atrazine, desethyl-atrazine and 2.6 dichlorobenzamide were exceeded few times when compared to required levels. In 2005 bentazone, MCPP, metolachlor, terbuthylazin were exceeded. In 2004 concentration of pesticides were exceeded in 25 samples in 15 different areas, supplying 183,881 inhabitants. In 2005 concentration of pesticides were exceeded in 31 samples in 14 different areas, supplying 151,297 inhabitants. The distribution shows, that contamination was present mostly in the northeast part of Slovenia, where intensive agriculture takes place.Conclusions: Received status review acquired by monitoring of pesticides in drinking water is only an assessment of circumstances that will gain in representativity by enlarged number of sampling locations and longer observation time. For assessment of trends of pollution of drinking water in Slovenia it will be necessary to monitor concentration of pesticides through longer period. We could have unpolluted drinking water only with restricted use of pesticides on water-protection ranges or

  2. Biofilm growth on polyvinylchloride surface incubated in suboptimal microbial warm water and effect of sanitizers on biofilm removal post biofilm formation

    Science.gov (United States)

    An in vitro experiment was conducted to understand the nature of biofilm growth on polyvinyl chloride (PVC) surface when exposed to sub optimal quality microbial water (> 4 log10 cfu/ml) obtained from poultry drinking water source mimicking water in waterlines during the first week of poultry broodi...

  3. BioMig--A Method to Evaluate the Potential Release of Compounds from and the Formation of Biofilms on Polymeric Materials in Contact with Drinking Water.

    Science.gov (United States)

    Wen, Gang; Kötzsch, Stefan; Vital, Marius; Egli, Thomas; Ma, Jun

    2015-10-06

    In contact with water, polymeric materials (plastics) release compounds that can support suspended microbial growth and/or biofilm formation. The different methods presently used in the European Union to test plastics take 7-16 weeks to obtain a result. In industry, this delays material and product development as well as quality testing. Therefore, we developed a method package (BioMig) that allows testing of plastic materials with high reproducibility in 2 weeks for their potential biofilm (or biomass) formation and release of carbonaceous migration products when in contact with water. BioMig consists of (i) an extended migration potential test (seven times for 24 h at 60 °C), based on the European norm EN 12873-1 and the German UBA (Umweltbundesamt) guideline, and (ii) a biomass formation potential (BFP) test (14 days at 30 °C), which is a modified version of the Dutch biofilm production potential test. In the migration potential test, the amount of carbon released into water by the specimen is quantified by monitoring total and assimilable organic carbon over time; furthermore, the modular design of the test also allows one to assess additional parameters such as pathogen growth potential on the migration water or toxic effects on microbial growth. Flow cytometry (FCM)-based total cell counting (TCC) is used to quantify microbial growth in suspension and on surfaces after removal with mild sonication without affecting cell integrity. The BFP test allows one to determine both the planktonic (pBFP) and the sessile (sBFP) cell fractions. The sBFP consists of surface-attached cells after removal (>90% efficiency). Results for four standard test materials (PE-Xa, PE-Xc, EPDM 2%, and EPDM 20%), plus positive (PVC-P) and negative (glass) controls are presented. FCM-based TCC demonstrates that the release of growth-supporting carbon and proliferation of surface-attached cells stops increasing and stabilizes after 14 days of incubation; this allows for faster

  4. DNase I and Proteinase K eliminate DNA from injured or dead bacteria but not from living bacteria in microbial reference systems and natural drinking water biofilms for subsequent molecular biology analyses.

    Science.gov (United States)

    Villarreal, Jessica Varela; Jungfer, Christina; Obst, Ursula; Schwartz, Thomas

    2013-09-01

    Molecular techniques, such as polymerase chain reaction (PCR) and quantitative PCR (qPCR), are very sensitive, but may detect total DNA present in a sample, including extracellular DNA (eDNA) and DNA coming from live and dead cells. DNase I is an endonuclease that non-specifically cleaves single- and double-stranded DNA. This enzyme was tested in this study to analyze its capacity of digesting DNA coming from dead cells with damaged cell membranes, leaving DNA from living cells with intact cell membranes available for DNA-based methods. For this purpose, an optimized DNase I/Proteinase K (DNase/PK) protocol was developed. Intact Staphylococcus aureus cells, heat-killed Pseudomonas aeruginosa cells, free genomic DNA of Salmonella enterica, and a mixture of these targets were treated according to the developed DNase/PK protocol. In parallel, these samples were treated with propidium monoazide (PMA) as an already described assay for live-dead discrimination. Quantitative PCR and PCR-DGGE of the eubacterial 16S rDNA fragment were used to test the ability of the DNase/PK and PMA treatments to distinguish DNA coming from cells with intact cell membranes in the presence of DNA from dead cells and free genomic DNA. The methods were applied to three months old autochthonous drinking water biofilms from a pilot facility built at a German waterworks. Shifts in the DNA patterns observed after DGGE analysis demonstrated the applicability of DNase/PK as well as of the PMA treatment for natural biofilm investigation. However, the DNase/PK treatment demonstrated some practical advantages in comparison with the PMA treatment for live/dead discrimination of bacterial targets in drinking water systems.

  5. Basic Information about Lead in Drinking Water

    Science.gov (United States)

    ... control treatment to prevent lead and copper from contaminating drinking water. Corrosion control treatment means utilities must ... Page How EPA Requires States and Public Water Systems to Protect Drinking Water The Safe Drinking Water ...

  6. Overview of biofilm formation in distribution systems and its impact on the deterioration of water quality

    CSIR Research Space (South Africa)

    Momba, MNB

    2000-01-01

    Full Text Available and significance of biofilms on the microbial quality of drinking water. The review addresses the main factors governing the formation of biofilms such as the types of disinfectants and residual concentrations, resistance of bacteria to disinfectants, the influence...

  7. Effect of Phosphorus on Survival of Escherichia coli in Drinking Water Biofilms▿

    OpenAIRE

    Juhna, Talis; Birzniece, Dagne; Rubulis, Janis

    2007-01-01

    The effect of phosphorus addition on survival of Escherichia coli in an experimental drinking water distribution system was investigated. Higher phosphorus concentrations prolonged the survival of culturable E. coli in water and biofilms. Although phosphorus addition did not affect viable but not culturable (VBNC) E. coli in biofilms, these structures could act as a reservoir of VBNC forms of E. coli in drinking water distribution systems.

  8. Lead in School Drinking Water.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC. Office of Water Programs.

    Lead levels in school drinking water merit special concern because children are more at risk than adults from exposure to lead. This manual provides ways in which school officials can minimize this risk. It assists administrators by providing: (1) general information on the significance of lead in school drinking water and its effects on children;…

  9. Hotspots for selected metal elements and microbes accumulation and the corresponding water quality deterioration potential in an unchlorinated drinking water distribution system

    NARCIS (Netherlands)

    Liu, Gang; Tao, Yu; Zhang, Ya Ping; Lut, Maarten; Knibbe, Willem Jan; Wielen, van der Paul; Liu, Wentso; Medema, Gertjan; Meer, van der Walter

    2017-01-01

    Biofilm formation, loose deposit accumulation and water quality deterioration in drinking water distribution systems have been widely reported. However, the accumulation and distribution of harbored elements and microbes in the different niches (loose deposits, PVC-U biofilm, and HDPE biofilm) and

  10. Impact of Hydraulic Well Restoration on Native Bacterial Communities in Drinking Water Wells

    OpenAIRE

    Karwautz, Clemens; Lueders, Tillmann

    2014-01-01

    The microbial monitoring of drinking water production systems is essential to assure water quality and minimize possible risks. However, the comparative impact of microbes from the surrounding aquifer and of those established within drinking water wells on water parameters remains poorly understood. High pressure jetting is a routine method to impede well clogging by fine sediments and also biofilms. In the present study, bacterial communities were investigated in a drinking water production ...

  11. Drinking Water Contaminants -- Standards and Regulations

    Science.gov (United States)

    ... Protection Agency Search Search Contact Us Share Drinking Water Contaminants – Standards and Regulations EPA identifies contaminants to regulate in drinking water to protect public health. The ...

  12. Biofilm formation in a hot water system

    DEFF Research Database (Denmark)

    Bagh, L.K.; Albrechtsen, Hans-Jørgen; Arvin, Erik

    2002-01-01

    The biofilm formation rate was measured in situ in a hot water system in an apartment building by specially designed sampling equipment, and the net growth of the suspended bacteria was measured by incubation of water samples with the indigeneous bacteria. The biofilm formation rate reached......, in the sludge, or in the water from the distribution system was negligible. This indicated that bacterial growth took place on the inner surfaces in the hot water system and biofilm formation and detachment of bacteria could account for most of the suspended bacteria actually measured in hot water. Therefore...

  13. Heterotrophic bacteria in drinking water distribution system: a review.

    Science.gov (United States)

    Chowdhury, Shakhawat

    2012-10-01

    The microbiological quality of drinking water in municipal water distribution systems (WDS) depends on several factors. Free residual chlorine and/or chloramines are typically used to minimize bacterial recontamination and/or regrowth in WDS. Despite such preventive measures, regrowth of heterotrophic (HPC) and opportunistic bacteria in bulk water and biofilms has yet to be controlled completely. No approach has shown complete success in eliminating biofilms or HPC bacteria from bulk water and pipe surfaces. Biofilms can provide shelter for pathogenic bacteria and protect these bacteria from disinfectants. Some HPC bacteria may be associated with aesthetic and non-life threatening diseases. Research to date has achieved important success in understanding occurrence and regrowth of bacteria in bulk water and biofilms in WDS. To achieve comprehensive understanding and to provide efficient control against bacteria regrowth, future research on bacteria regrowth dynamics and their implications is warranted. In this study, a review was performed on the literature published in this area. The findings and limitations of these papers are summarized. Occurrences of bacteria in WDS, factors affecting bacteria regrowth in bulk water and biofilms, bacteria control strategies, sources of nutrients, human health risks from bacterial exposure, modelling of bacteria regrowth and methods of bacteria sampling and detection and quantification are investigated. Advances to date are noted, and future research needs are identified. Finally, research directions are proposed to effectively control HPC and opportunistic bacteria in bulk water and biofilms in WDS.

  14. The risks of drinking water

    Science.gov (United States)

    Reichhardt, Tony

    1984-04-01

    Three researchers from the Energy and Environmental Policy Center at Harvard University have come up with a new method of calculating the risk from contaminants in drinking water, one that they believe takes into account some of the uncertainties in pronouncing water safe or dangerous to drink. The new method concentrates on the risk of cancer, which authors Edmund Crouch, Richard Wilson, and Lauren Zeise believe has not been properly considered in establishing drinking water standards.Writing in the December 1983 issue of Water Resources Research, the authors state that “current [drinking water] standards for a given chemical or class of chemicals do not account for the presence of other pollutants” that could combine to create dangerous substances. According to Wilson, “Over a hundred industrial pollutants and chlorination byproducts have been found in various samples of drinking water, some of which are known carcinogens, others suspected carcinogens.” The same chlorine that solves one major health problem—the threat of bacterial disease—can thus contribute to another, according to the authors, by increasing the long-term risk of cancer. The largest risks are due to halomethanes such as chloroform and bromoform, produced as chlorine reacts with organic matter in drinking water.

  15. Drinking Water State Revolving Fund

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Drinking Water State Revolving Fund (DWSRF) National Information Management System collects information that provide a record of progress and accountability for...

  16. Responsibility for drinking water; Verantwortung fuer Trinkwasser

    Energy Technology Data Exchange (ETDEWEB)

    Lein, Peter [Ingenieurbuero Dipl.-Ing. Peter Lein, Berlin (Germany)

    2008-03-15

    Planners of drinking water supply systems, implementing sanitary companies as well as building owners probably can be made liable, if the user of drinking water supply systems suffer health damages by drinking water hygienic problems. The germinating of the drinking water with legionella often is the consequence of a not professional start-up of a plant immediately after completion.

  17. In situ examination of microbial populations in a model drinking water distribution system

    DEFF Research Database (Denmark)

    Martiny, Adam Camillo; Nielsen, Alex Toftgaard; Arvin, Erik

    2002-01-01

    A flow cell set-up was used as a model drinking water distribution system to analyze the in situ microbial population. Biofilm growth was followed by transmission light microscopy for 81 days and showed a biofilm consisting of microcolonies separated by a monolayer of cells. Protozoans (ciliates...

  18. [Drinking water quality and safety].

    Science.gov (United States)

    Gómez-Gutiérrez, Anna; Miralles, Maria Josepa; Corbella, Irene; García, Soledad; Navarro, Sonia; Llebaria, Xavier

    2016-11-01

    The purpose of drinking water legislation is to guarantee the quality and safety of water intended for human consumption. In the European Union, Directive 98/83/EC updated the essential and binding quality criteria and standards, incorporated into Spanish national legislation by Royal Decree 140/2003. This article reviews the main characteristics of the aforementioned drinking water legislation and its impact on the improvement of water quality against empirical data from Catalonia. Analytical data reported in the Spanish national information system (SINAC) indicate that water quality in Catalonia has improved in recent years (from 88% of analytical reports in 2004 finding drinking water to be suitable for human consumption, compared to 95% in 2014). The improvement is fundamentally attributed to parameters concerning the organoleptic characteristics of water and parameters related to the monitoring of the drinking water treatment process. Two management experiences concerning compliance with quality standards for trihalomethanes and lead in Barcelona's water supply are also discussed. Finally, this paper presents some challenges that, in the opinion of the authors, still need to be incorporated into drinking water legislation. It is necessary to update Annex I of Directive 98/83/EC to integrate current scientific knowledge, as well as to improve consumer access to water quality data. Furthermore, a need to define common criteria for some non-resolved topics, such as products and materials in contact with drinking water and domestic conditioning equipment, has also been identified. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

  19. Chlorine stress mediates microbial surface attachment in drinking water systems.

    Science.gov (United States)

    Liu, Li; Le, Yang; Jin, Juliang; Zhou, Yuliang; Chen, Guowei

    2015-03-01

    Microbial attachment to drinking water pipe surfaces facilitates pathogen survival and deteriorates disinfection performance, directly threatening the safety of drinking water. Notwithstanding that the formation of biofilm has been studied for decades, the underlying mechanisms for the origins of microbial surface attachment in biofilm development in drinking water pipelines remain largely elusive. We combined experimental and mathematical methods to investigate the role of environmental stress-mediated cell motility on microbial surface attachment in chlorination-stressed drinking water distribution systems. Results show that at low levels of disinfectant (0.0-1.0 mg/L), the presence of chlorine promotes initiation of microbial surface attachment, while higher amounts of disinfectant (>1.0 mg/L) inhibit microbial attachment. The proposed mathematical model further demonstrates that chlorination stress (0.0-5.0 mg/L)-mediated microbial cell motility regulates the frequency of cell-wall collision and thereby controls initial microbial surface attachment. The results reveal that transport processes and decay patterns of chlorine in drinking water pipelines regulate microbial cell motility and, thus, control initial surface cell attachment. It provides a mechanistic understanding of microbial attachment shaped by environmental disinfection stress and leads to new insights into microbial safety protocols in water distribution systems.

  20. Comparison of extraction methods for extracellular polymeric substances from a drinking water biofilm-forming bacteria%管网生物膜菌株胞外聚合物的提取方法比较

    Institute of Scientific and Technical Information of China (English)

    邬卓颖; 郭峰; 叶成松; 张胜华; 于鑫

    2012-01-01

    以饮用水管网生物膜样品中一株强成膜能力的菌株Pleomorphomonas oryzae作为研究对象,考察了8种方法(高速离心法、超声法、加热法、EDTA法、H2SO4法、NaOH法、SDS法、甲醛法)对菌株胞外聚合物(EPS)的提取效果,并结合三维荧光光谱(EEM)和傅立叶红外光谱(FTIR)对提取的EPS进行成分分析.结果表明,EDTA法和H2SO4法既能提高EPS的提取效率,提取量分别为64.77 mg.g-1SS和74.43 mg.g-1SS,是离心方法提取量的1.62倍和1.86倍,又不会在提取过程中对菌株细胞造成破坏,是较为理想的EPS提取方法.EEM分析进一步证实,NaOH法对菌株细胞破坏严重,造成EPS成分变化较大.FTIR分析则说明,化学提取方法相较于物理提取方法会引入杂质对组分测定造成干扰.%Drinking water distribution systems(DWDS) often face the problem of biofilm formation,which results in microbial contamination,and furthermore influence the water quality and population health.The extracellular polymeric substances(EPS) is the major component of biofilm which accounts for over 90%,and its physical and chemical properties have effects on biofilm adhesion and formation.Eight methods for extracting EPS from a drinking water distribution system related bacteria,Pleomorphomonas oryzae,(centrifugation,sonication,heating,EDTA,H2SO4,NaOH,SDS,formaldehyde) were investigated,and then three-dimensional excitation and emission matrix(EEM) fluorescence spectroscopy and Fourier transform infrared(FTIR) spectroscopy were used to supplement the chemical analysis.The results showed that the EDTA and H2SO4 method were efficient and did not cause cell disruption.These two methods obtained 64.77 mg · g-1 SS and 74.43 mg · g-1 SS from bacterial culture,higher than that of the centrifugation method by 1.62 and 1.86 times,respectively.EEM fluorescence spectra of EPS extracted by NaOH method indicates that the method was so severe that cell

  1. Impact of Environmental Factors on Legionella Populations in Drinking Water

    Directory of Open Access Journals (Sweden)

    David Otto Schwake

    2015-05-01

    Full Text Available To examine the impact of environmental factors on Legionella in drinking water distribution systems, the growth and survival of Legionella under various conditions was studied. When incubated in tap water at 4 °C, 25 °C, and 32 °C, L. pneumophila survival trends varied amongst the temperatures, with the stable populations maintained for months at 25 °C and 32 °C demonstrating that survival is possible at these temperatures for extended periods in oligotrophic conditions. After inoculating coupons of PVC, copper, brass, and cast iron, L. pneumophila colonized biofilms formed on each within days to a similar extent, with the exception of cast iron, which contained 1-log less Legionella after 90 days. L. pneumophila spiked in a model drinking water distribution system colonized the system within days. Chlorination of the system had a greater effect on biofilm-associated Legionella concentrations, with populations returning to pre-chlorination levels within six weeks. Biofilms sampled from drinking water meters collected from two areas within central Arizona were analyzed via PCR for the presence of Legionella. Occurrence in only one area indicates that environmental differences in water distribution systems may have an impact on the survival of Legionella. These results document the impact of different environmental conditions on the survival of Legionella in water.

  2. How dogs drink water

    Science.gov (United States)

    Gart, Sean; Socha, Jake; Vlachos, Pavlos; Jung, Sunghwan

    2014-11-01

    Animals with incomplete cheeks (i.e. dogs and cats) need to move fluid against gravity into the body by means other than suction. They do this by lapping fluid with their tongue. When a dog drinks, it curls its tongue posteriorly while plunging it into the fluid and then quickly withdraws its tongue back into the mouth. During this fast retraction fluid sticks to the ventral part of the curled tongue and is drawn into the mouth due to inertia. We show several variations of this drinking behavior among many dog breeds, specifically, the relationship between tongue dynamics and geometry, lapping frequency, and dog weight. We also compare the results with the physical experiment of a rounded rod impact onto a fluid surface. Supported by NSF PoLS #1205642.

  3. Giardia and Drinking Water from Private Wells

    Science.gov (United States)

    ... type="submit" value="Submit" /> Healthy Water Home Giardia and Drinking Water from Private Wells Recommend on ... visit CDC's Giardia website. Where and how does Giardia get into drinking water? Millions of Giardia parasites ...

  4. Biofilm removal with a dental water jet.

    Science.gov (United States)

    Gorur, Amita; Lyle, Deborah M; Schaudinn, Christoph; Costerton, John W

    2009-03-01

    The objective of this study was to evaluate the effect of a dental water jet on plaque biofilm removal using scanning electron microscopy (SEM). Eight teeth with advanced aggressive periodontal disease were extracted. Ten thin slices were cut from four teeth. Two slices were used as the control. Eight were inoculated with saliva and incubated for 4 days. Four slices were treated using a standard jet tip, and four slices were treated using an orthodontic jet tip. The remaining four teeth were treated with the orthodontic jet tip but were not inoculated with saliva to grow new plaque biofilm. All experimental teeth were treated using a dental water jet for 3 seconds on medium pressure. The standard jet tip removed 99.99% of the salivary (ex vivo) biofilm, and the orthodontic jet tip removed 99.84% of the salivary biofilm. Observation of the remaining four teeth by the naked eye indicated that the orthodontic jet tip removed significant amounts of calcified (in vivo) plaque biofilm. This was confirmed by SEM evaluations. The Waterpik dental water jet (Water Pik, Inc, Fort Collins, CO) can remove both ex vivo and in vivo plaque biofilm significantly.

  5. Volatile organic compounds in natural biofilm in polyethylene pipes supplied with lake water and treated water from the distribution network.

    Science.gov (United States)

    Skjevrak, Ingun; Lund, Vidar; Ormerod, Kari; Herikstad, Hallgeir

    2005-10-01

    The objective of this work was investigation of volatile organic compounds (VOC) in natural biofilm inside polyethylene (HDPE) pipelines at continuously flowing water. VOC in biofilm may contribute to off-flavour episodes in drinking water. The pipelines were supplied with raw lake water and treated water from the distribution network. Biofilm was established at test sites located at two different drinking water distribution networks and their raw water sources. A whole range of volatile compounds were identified in the biofilm, including compounds frequently associated with cyanobacteria and algae, such as ectocarpene, dictyopterene A and C', geosmin, beta-ionone and 6-methyl-5-hepten-2-one. In addition, volatile amines, dimethyldisulphide and 2-nonanone, presumably originating from microorganisms growing in the biofilm, were identified. C8-compounds such as 1-octen-3-one and 3-octanone were believed to be products from microfungi in the biofilm. Degradation products from antioxidants such as Irgafos 168, Irganox 1010 and Irganox 1076 used in HDPE pipes, corresponding to 2,4-di-tert-butylphenol and 2,6-di-tert-butylbenzoquinone, were present in the biofilm.

  6. DRINK WATER, WASTEWATER - CUSTOMERS` AWARENESS AND ATTITUDE

    OpenAIRE

    Petrescu, Dacinia Crina; Mihaela TUTUNEA

    2012-01-01

    The objective of the study is to establish behavioural patterns related to drink water and beliefs on water and on the water company.Four main issues are analysed: the awareness on the services delivered by the water company, the use of drink water from the tap, the evaluation of general quality of the water and the cause of dissatisfaction with the water quality. The results show good awarenesson drink water transportation, medium for raw water treatment, low for wastewater collection and tr...

  7. Irrigation waters and pipe-based biofilms as sources for antibiotic-resistant bacteria

    Science.gov (United States)

    The presence of antibiotic-resistant bacteria in environmental surface waters has gained recent attention. Wastewater- and drinking water distribution systems are known to disseminate antibiotic-resistant bacteria, with the biofilms that form on the inner-surfaces of the pipeline as a hotspot for pr...

  8. Manganese in Madison's drinking water.

    Science.gov (United States)

    Schlenker, Thomas; Hausbeck, John; Sorsa, Kirsti

    2008-12-01

    Public concern over events of manganese-discolored drinking water and the potential for adverse health effects from exposure to excess manganese reached a high level in 2005. In response, Public Health Madison Dane County, together with the Madison Water Utility, conceived and implemented a public health/water utility strategy to quantify the extent of the manganese problem, determine the potential for adverse human health effects, and communicate these findings to the community. This strategy included five basic parts: taking an inventory of wells and their manganese levels, correlating manganese concentration with turbidity, determining the prevalence and distribution of excess manganese in Madison households, reviewing the available scientific literature, and effectively communicating our findings to the community. The year-long public health/water utility strategy successfully resolved the crisis of confidence in the safety of Madison's drinking water.

  9. Preliminary assessment of the interaction of introduced biological agents with biofilms in water distribution systems.

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, Michael B.; Caldwell, Sara; Jones, Howland D. T.; Altman, Susan Jeanne; Souza, Caroline Ann; McGrath, Lucas K.

    2005-12-01

    Basic research is needed to better understand the potential risk of dangerous biological agents that are unintentionally or intentionally introduced into a water distribution system. We report on our capabilities to conduct such studies and our preliminary investigations. In 2004, the Biofilms Laboratory was initiated for the purpose of conducting applied research related to biofilms with a focus on application, application testing and system-scale research. Capabilities within the laboratory are the ability to grow biofilms formed from known bacteria or biofilms from drinking water. Biofilms can be grown quickly in drip-flow reactors or under conditions more analogous to drinking-water distribution systems in annular reactors. Biofilms can be assessed through standard microbiological techniques (i .e, aerobic plate counts) or with various visualization techniques including epifluorescent and confocal laser scanning microscopy and confocal fluorescence hyperspectral imaging with multivariate analysis. We have demonstrated the ability to grow reproducible Pseudomonas fluorescens biofilms in the annular reactor with plate counts on the order of 10{sup 5} and 10{sup 6} CFU/cm{sup 2}. Stationary phase growth is typically reached 5 to 10 days after inoculation. We have also conducted a series of pathogen-introduction experiments, where we have observed that both polystyrene microspheres and Bacillus cereus (as a surrogate for B. anthracis) stay incorporated in the biofilms for the duration of our experiments, which lasted as long as 36 days. These results indicated that biofilms may act as a safe harbor for bio-pathogens in drinking water systems, making it difficult to decontaminate the systems.

  10. CFD in drinking water treatment

    NARCIS (Netherlands)

    Wols, B.A.

    2010-01-01

    Hydrodynamic processes largely determine the efficacy of drinking water treatment systems, in particular disinfection systems. A lack of understanding of the hydrodynamics has resulted in suboptimal designs of these systems. The formation of unwanted disinfection-by-products and the energy consumpti

  11. CFD in drinking water treatment

    NARCIS (Netherlands)

    Wols, B.A.

    2010-01-01

    Hydrodynamic processes largely determine the efficacy of drinking water treatment systems, in particular disinfection systems. A lack of understanding of the hydrodynamics has resulted in suboptimal designs of these systems. The formation of unwanted disinfection-by-products and the energy consumpti

  12. CFD in drinking water treatment

    NARCIS (Netherlands)

    Wols, B.A.

    2010-01-01

    Hydrodynamic processes largely determine the efficacy of drinking water treatment systems, in particular disinfection systems. A lack of understanding of the hydrodynamics has resulted in suboptimal designs of these systems. The formation of unwanted disinfection-by-products and the energy

  13. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges

    KAUST Repository

    Prest, Emmanuelle I.

    2016-02-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order

  14. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges

    Science.gov (United States)

    Prest, Emmanuelle I.; Hammes, Frederik; van Loosdrecht, Mark C. M.; Vrouwenvelder, Johannes S.

    2016-01-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order

  15. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges.

    Science.gov (United States)

    Prest, Emmanuelle I; Hammes, Frederik; van Loosdrecht, Mark C M; Vrouwenvelder, Johannes S

    2016-01-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order

  16. Biological stability of drinking water: controlling factors, methods and challenges

    Directory of Open Access Journals (Sweden)

    Emmanuelle ePrest

    2016-02-01

    Full Text Available Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g. development of opportunistic pathogens, aesthetic (e.g. deterioration of taste, odour, colour or operational (e.g. fouling or biocorrosion of pipes problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors such as (i type and concentration of available organic and inorganic nutrients, (ii type and concentration of residual disinfectant, (iii presence of predators such as protozoa and invertebrates, (iv environmental conditions such as water temperature, and (v spatial location of microorganisms (bulk water, sediment or biofilm. Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i existing knowledge on biological stability controlling factors and (ii how these factors are affected by drinking water production and distribution conditions. In addition, (iii the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discuss how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order to

  17. Bacterial community of biofilms developed under different water supply conditions in a distribution system.

    Science.gov (United States)

    Sun, Huifang; Shi, Baoyou; Bai, Yaohui; Wang, Dongsheng

    2014-02-15

    In order to understand the bacterial community characteristics of biofilms developed under different finished water supply histories in drinking water distribution systems (DWDS), biofilm samples on different type of iron corrosion scales in a real DWDS were collected and systematically investigated using 454 pyrosequencing of 16S rRNA gene. The richness and diversity estimators showed that biofilms formed in DWDS transporting finished groundwater (GW) had the lowest level of bacterial diversity. From phylum to genus level, the dominant bacterial groups found in the biofilms under finished surface water (SW) and GW conditions were distinct. Proteobacteria was the dominant group in all biofilm samples (in the range of 40%-97%), but was relatively higher in biofilms with GW. The relative abundance of Firmicutes in biofilms with SW (28%-35%) was significantly higher (piron-reducing bacteria (mainly Bacillus) and iron-oxidizing bacteria (mainly Acidovorax) were relatively higher in biofilms with SW, which might contribute to the formation of much thicker or tubercle-formed corrosion scales under SW supply condition. Several potential opportunistic pathogens, such as Burkholderia fungorum, Mycobacterium neoaurum, Mycobacterium frederiksbergense were detected in the biofilms.

  18. Analysis of black fungal biofilms occurring at domestic water taps. II: potential routes of entry.

    Science.gov (United States)

    Heinrichs, Guido; Hübner, Iris; Schmidt, Carsten K; de Hoog, G Sybren; Haase, Gerhard

    2013-06-01

    Formation of tenacious and massive black biofilms was occasionally observed at the water-air interphase of water taps and in associated habitats at several locations in Germany. Exophiala lecanii-corni was proven to be the dominant component of these biofilms. Water utility companies were interested to understand by which route fungi building these black biofilms enter their habitat at affected sites in domestic sanitary. A wide variety of fungi is known to be common in wet indoor environments, as well as in the drinking water resources. Two possible routes of entry are therefore considered as follows: (a) distribution by the drinking water system or (b) a retrograde route of colonisation. Previous compositional analysis revealed that the black constituents of biofilms primarily belong to the herpotrichiellaceous black yeast and relatives. Therefore, a systematic search for black fungi in the drinking water system was performed using Sabouraud's glucose agar medium with chloramphenicol and erythritol-chloramphenicol agar as isolation media. Cadophora malorum was the dominant fungus in the investigated drinking water systems, and samples taken from the house connections (n = 50; 74 %, route of contamination in case of E. lecanii-corni can be assumed.

  19. An experimental study on the influence of water stagnation and temperature change on water quality in a full-scale domestic drinking water system.

    Science.gov (United States)

    Zlatanović, Lj; van der Hoek, J P; Vreeburg, J H G

    2017-10-15

    The drinking water quality changes during the transport through distribution systems. Domestic drinking water systems (DDWSs), which include the plumbing between the water meter and consumer's taps, are the most critical points in which water quality may be affected. In distribution networks, the drinking water temperature and water residence time are regarded as indicators of the drinking water quality. This paper describes an experimental research on the influence of stagnation time and temperature change on drinking water quality in a full-scale DDWS. Two sets of stagnation experiments, during winter and summer months, with various stagnation intervals (up to 168 h of stagnation) were carried out. Water and biofilms were sampled at two different taps, a kitchen and a shower tap. Results from this study indicate that temperature and water stagnation affect both chemical and microbial quality in DDWSs, whereas microbial parameters in stagnant water appear to be driven by the temperature of fresh water. Biofilm formed in the shower pipe contained more total and intact cells than the kitchen pipe biofilm. Alphaproteobacteria were found to dominate in the shower biofilm (78% of all Proteobacteria), while in the kitchen tap biofilm Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria were evenly distributed. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Regulation Development for Drinking Water Contaminants

    Science.gov (United States)

    To explain what process and information underlies regulations including how the Safe Drinking Water Act applies to regulation development i.e. how does the drinking water law translate into regulations.

  1. [On the rating of Helicobacter pylori in drinking water].

    Science.gov (United States)

    Fedichkina, T P; Solenova, L G; Zykova, I E

    2014-01-01

    There are considered the issues related to the possibility to rate of Helicobacter pylori (H. pylori) content in drinking water. There is described the mechanism of of biofilm formation. The description refers to the biofilm formation mechanism in water supply systems and the existence of H. pylori in those systems. The objective premises of the definition of H. pylori as a potential limiting factor for assessing the quality of drinking water have been validated as follows: H. pylori is an etiologic factor associated to the development of chronic antral gastritis, gastric ulcer and duodenal ulcer, and gastric cancer either, in the Russian population the rate of infection with H. pylori falls within range of 56 - 90%, water supply pathway now can be considered as a source of infection of the population with H. pylori, the existence of WHO regulatory documents considering H. pylori as a candidate for standardization of the quality of the drinking water quite common occurrence of biocorrosion, the reduction of sanitary water network reliability, that creates the possibility of concentrating H. pylori in some areas of the water system and its delivery to the consumer of drinking water, and causes the necessity of the prevention of H. pylori-associated gastric pathology of the population. A comprehensive and harmonized approach to H. pylori is required to consider it as a candidate to its rating in drinking water. Bearing in mind the large economic losses due to, on the one hand, the prevalence of disease caused by H. pylori, and, on the other hand, the biocorrosion of water supply system, the problem is both relevant in terms of communal hygiene and economy.

  2. Decontamination of Drinking Water Infrastructure ...

    Science.gov (United States)

    Technical Brief This study examines the effectiveness of decontaminating corroded iron and cement-mortar coupons that have been contaminated with spores of Bacillus atrophaeus subsp. globigii (B. globigii), which is often used as a surrogate for pathogenic B. anthracis (anthrax) in disinfection studies. Bacillus spores are persistent on common drinking water material surfaces like corroded iron, requiring physical or chemical methods to decontaminate the infrastructure. In the United States, free chlorine and monochloramine are the primary chemical disinfectants used by the drinking water industry to inactivate microorganisms. Flushing is also a common, easily implemented practice in drinking water distribution systems, although large volumes of contaminated water needing treatment could be generated. Identifying readily available alternative disinfectant formulations for infrastructure decontamination could give water utilities options for responding to specific types of contamination events. In addition to presenting data on flushing alone, which demonstrated the persistence of spores on water infrastructure in the absence of high levels of disinfectants, data on acidified nitrite, chlorine dioxide, free chlorine, monochloramine, ozone, peracetic acid, and followed by flushing are provided.

  3. Detection of Actinobacillus pleuropneumoniae in drinking water from pig farms.

    Science.gov (United States)

    Loera-Muro, Victor M; Jacques, Mario; Tremblay, Yannick D N; Avelar-González, Francisco J; Loera Muro, Abraham; Ramírez-López, Elsa M; Medina-Figueroa, Alejandra; González-Reynaga, Higinio M; Guerrero-Barrera, Alma L

    2013-03-01

    Actinobacillus pleuropneumoniae is the aetiological agent of porcine pleuropneumonia and is normally transmitted by aerosols and direct contact between animals. A. pleuropneumoniae has traditionally been considered an obligate pathogen of pigs and its presence in the environment has yet to be investigated. Here, the presence of A. pleuropneumoniae was detected in drinking water of pig farms in Mexico using a PCR specific for the RTX toxin gene, apxIV. The presence of A. pleuropneumoniae in farm drinking water was confirmed by indirect immunofluorescence using an A. pleuropneumoniae-specific polyclonal antibody and by fluorescent in situ hybridization. Viable bacteria from the farm drinking water were detected using the Live/Dead BacLight stain. Additionally, viable A. pleuropneumoniae was selected and isolated using the cAMP test and the identity of the isolated bacteria were confirmed by Gram staining, a specific polyclonal antibody and an A. pleuropneumoniae-specific PCR. Furthermore, biofilms were observed by scanning electron microscopy in A. pleuropneumoniae-positive samples. In conclusion, our data suggest that viable A. pleuropneumoniae is present in the drinking water of swine farms and may use biofilm as a strategy to survive in the environment.

  4. 30 CFR 75.1718 - Drinking water.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drinking water. 75.1718 Section 75.1718 Mineral... SAFETY STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1718 Drinking water. An adequate supply of potable water shall be provided for drinking purposes in the active workings of the mine, and such...

  5. Comammox in drinking water systems.

    Science.gov (United States)

    Wang, Yulin; Ma, Liping; Mao, Yanping; Jiang, Xiaotao; Xia, Yu; Yu, Ke; Li, Bing; Zhang, Tong

    2017-06-01

    The discovery of complete ammonia oxidizer (comammox) has fundamentally upended our perception of the global nitrogen cycle. Here, we reported four metagenome assembled genomes (MAGs) of comammox Nitrospira that were retrieved from metagenome datasets of tap water in Singapore (SG-bin1 and SG-bin2), Hainan province, China (HN-bin3) and Stanford, CA, USA (ST-bin4). Genes of phylogenetically distinct ammonia monooxygenase subunit A (amoA) and hydroxylamine dehydrogenase (hao) were identified in these four MAGs. Phylogenetic analysis based on ribosomal proteins, AmoA, hao and nitrite oxidoreductase (subunits nxrA and nxrB) sequences indicated their close relationships with published comammox Nitrospira. Canonical ammonia-oxidizing microbes (AOM) were also identified in the three tap water samples, ammonia-oxidizing bacteria (AOB) in Singapore's and Stanford's samples and ammonia-oxidizing archaea (AOA) in Hainan's sample. The comammox amoA-like sequences were also detected from some other drinking water systems, and even outnumbered the AOA and AOB amoA-like sequences. The findings of MAGs and the occurrences of AOM in different drinking water systems provided a significant clue that comammox are widely distributed in drinking water systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Safe Drinking Water

    Centers for Disease Control (CDC) Podcasts

    2008-04-23

    Listen to this podcast to learn more about the steps that are taken to bring you clean tap water.  Created: 4/23/2008 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 5/1/2008.

  7. DRINKING WATER TREATMENT

    Science.gov (United States)

    The purpose of water treatment is threefold: 1. To improve the aethetic quality ofwater, 2. to remove toxic or health-hazardous chemicals, 3. to remove and/or inactivate any disease causing microorganisms. These objectives should be accomplished using a reasonable safety factor...

  8. Drinking Water Maximum Contaminant Levels (MCLs)

    Data.gov (United States)

    U.S. Environmental Protection Agency — National Primary Drinking Water Regulations (NPDWRs or primary standards) are legally enforceable standards that apply to public water systems. Primary standards...

  9. Drinking Water Temperature Modelling in Domestic Systems

    NARCIS (Netherlands)

    Moerman, A.; Blokker, M.; Vreeburg, J.; Van der Hoek, J.P.

    2014-01-01

    Domestic water supply systems are the final stage of the transport process to deliver potable water to the customers’ tap. Under the influence of temperature, residence time and pipe materials the drinking water quality can change while the water passes the domestic drinking water system. According

  10. DRINKING WATER RESOURCES IN CROATIA

    Directory of Open Access Journals (Sweden)

    Darko Mayer

    1996-12-01

    Full Text Available Annualy renewed resources of drinking water on the Earth are about 45000 cu. km. With today's stage of development that quantity is enough for living 4.5 to 9 billion of people. As it is expected that by 2025 the population on our planet will be over 8.5 billion people, it is clear that the next century will be characterized by the problem of ensuring enaugh quantities of drinking water. This problem will be particularly emphasized in the developing countries and large cities. In the poor countries of arid and subarid areas water deficit will cause the food production crisis and large migrations of the population with almost unpredistable sociological, economical and political consequences could be expected. In the developed world the "water crisis" will stimulate scientific and tehnological progress. The Republic of Croatia, if examined as a whole, regarding the climatic, hydrological, hydrogeological and demographic conditions, has planty of good quality water. It is our duty to preserve this resources for future generations (the paper is published in Croatian.

  11. Filamentous fungi in drinking water tanks of a water supply system in Recife-PE, Brazil

    OpenAIRE

    Silva, P. B. R.; Santana, J. B. de; Oliveira, H. M. B.; Siqueira, Virgínia M.; Santos, C.; Lima, Nelson; Gusmão, N. B.

    2012-01-01

    Drinking water reservoirs are widely used in various building constructions in Brazil for as a source of potable water for users. However, they are susceptible to the growth of microorganisms such as fungi. From these, several negative factors may ensue, namely, unpleasant odors and flavours, pigments, biofilm formation and mycotoxins. This is caused fungal resistance to treatment and disinfection. Brazilian law and those of other countries offer no encouragement for the resear...

  12. LCA of Drinking Water Supply

    DEFF Research Database (Denmark)

    Godskesen, Berit; Meron, Noa; Rygaard, Martin

    2017-01-01

    Water supplies around the globe are growing complex and include more intense treatment methods than just decades ago. Now, desalination of seawater and wastewater reuse for both non-potable and potable water supply have become common practice in many places. LCA has been used to assess the potent......Water supplies around the globe are growing complex and include more intense treatment methods than just decades ago. Now, desalination of seawater and wastewater reuse for both non-potable and potable water supply have become common practice in many places. LCA has been used to assess...... the potentials and reveal hotspots among the possible technologies and scenarios for water supplies of the future. LCA studies have been used to support decisions in the planning of urban water systems and some important findings include documentation of reduced environmental impact from desalination of brackish...... water over sea water, the significant impacts from changed drinking water quality and reduced environmental burden from wastewater reuse instead of desalination. Some of the main challenges in conducting LCAs of water supply systems are their complexity and diversity, requiring very large data...

  13. Impact of hydraulic well restoration on native bacterial communities in drinking water wells.

    Science.gov (United States)

    Karwautz, Clemens; Lueders, Tillmann

    2014-01-01

    The microbial monitoring of drinking water production systems is essential to assure water quality and minimize possible risks. However, the comparative impact of microbes from the surrounding aquifer and of those established within drinking water wells on water parameters remains poorly understood. High pressure jetting is a routine method to impede well clogging by fine sediments and also biofilms. In the present study, bacterial communities were investigated in a drinking water production system before, during, and after hydraulic purging. Variations were observed in bacterial communities between different wells of the same production system before maintenance, despite them having practically identical water chemistries. This may have reflected the distinct usage practices of the different wells, and also local aquifer heterogeneity. Hydraulic jetting of one well preferentially purged a subset of the dominating taxa, including lineages related to Diaphorobacter, Nitrospira, Sphingobium, Ralstonia, Alkanindiges, Janthinobacterium, and Pseudomonas spp, suggesting their tendency for growth in well-associated biofilms. Lineages of potential drinking water concern (i.e. Legionellaceae, Pseudomonadaceae, and Acinetobacter spp.) reacted distinctly to hydraulic jetting. Bacterial diversity was markedly reduced in drinking water 2 weeks after the cleaning procedure. The results of the present study provide a better understanding of drinking water wells as a microbial habitat, as well as their role in the microbiology of drinking water systems.

  14. Water Districts - MO 2010 Active Public Drinking Water Systems (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This point layer represents active public drinking water systems. Each public drinking water system's distribution or service area is represented by a single point.

  15. Pharmaceutical compounds in drinking water

    Directory of Open Access Journals (Sweden)

    Vikas Chander

    2016-06-01

    Full Text Available Pharmaceutical products and their wastes play a major role in the degradation of environment. These drugs have positive as well as negative consequences on different environmental components including biota in different ways. Many types of pharmaceutical substances have been detected with significant concentrations through various advanced instrumental techniques in surface water, subsurface water, ground water, domestic waste water, municipal waste water and industrial effluents. The central as well as state governments in India are providing supports by creating excise duty free zones to promote the pharmaceutical manufacturers for their production. As a result, pharmaceutical companies are producing different types of pharmaceutical products at large scale and also producing complex non-biodegradable toxic wastes byproducts and releasing untreated or partially treated wastes in the environment in absence of strong regulations. These waste pollutants are contaminating all types of drinking water sources. The present paper focuses on water quality pollution by pharmaceutical pollutants, their occurrences, nature, metabolites and their fate in the environment.

  16. Lead and Drinking Water from Private Wells

    Science.gov (United States)

    ... submit” value=”Submit” /> Healthy Water Home Lead and Drinking Water from Private Wells Recommend on ... remove lead from my drinking water? What is lead? Lead is a naturally occurring bluish-gray metal ...

  17. Microbial dynamics in drinking water biofilms

    OpenAIRE

    Codony Iglesias, Francesc

    2015-01-01

    El agua de consumo subministrada a través de las redes de distribución deviene alterada durante su circulación en el mismo debido a la actividad microbiana. Estos cambios en la calidad a menudo afectan al sabor, color y al olor. En otros casos, la calidad sanitaria de agua es alterada debido al recrecimiento bacteriano. La masa del agua, es el mayor hábitat de un sistema de aguas potables, aunque la mayoría de cambios significativos en sus propiedades tienen lugar en las superficies de contac...

  18. Pyrosequencing analysis of the bacterial community in drinking water wells.

    Science.gov (United States)

    Navarro-Noya, Yendi E; Suárez-Arriaga, Mayra C; Rojas-Valdes, Aketzally; Montoya-Ciriaco, Nina M; Gómez-Acata, Selene; Fernández-Luqueño, Fabián; Dendooven, Luc

    2013-07-01

    Wells used for drinking water often have a large biomass and a high bacterial diversity. Current technologies are not always able to reduce the bacterial population, and the threat of pathogen proliferation in drinking water sources is omnipresent. The environmental conditions that shape the microbial communities in drinking water sources have to be elucidated, so that pathogen proliferation can be foreseen. In this work, the bacterial community in nine water wells of a groundwater aquifer in Northern Mexico were characterized and correlated to environmental characteristics that might control them. Although a large variation was observed between the water samples, temperature and iron concentration were the characteristics that affected the bacterial community structure and composition in groundwater wells. Small increases in the concentration of iron in water modified the bacterial communities and promoted the growth of the iron-oxidizing bacteria Acidovorax. The abundance of the genera Flavobacterium and Duganella was correlated positively with temperature and the Acidobacteria Gp4 and Gp1, and the genus Acidovorax with iron concentrations in the well water. Large percentages of Flavobacterium and Pseudomonas bacteria were found, and this is of special concern as bacteria belonging to both genera are often biofilm developers, where pathogens survival increases.

  19. Radon in private drinking water wells.

    Science.gov (United States)

    Otahal, P; Merta, J; Burian, I

    2014-07-01

    At least 10% of inhabitants in the Czech Republic are supplied with water from private sources (private wells, boreholes). With the increasing cost of water, the number of people using their own sources of drinking water will be likely to increase. According to the Decree of the State Office for Nuclear Safety about the Radiation Protection 307/2002 as amended by Decree 499/2005, the guideline limit for the supplied drinking water ('drinking water for public supply') for radon concentration is 50 Bq·l(-1). This guideline does not apply to private sources of drinking water. Radon in water influences human health by ingestion and also by inhalation when radon is released from water during showering and cooking. This paper presents results of measurements of radon concentrations in water from private wells in more than 300 cases. The gross concentration of alpha-emitting radionuclides and the concentrations of radium and uranium were also determined.

  20. Safe drinking water: the toxicologist's approach.

    Science.gov (United States)

    van Leeuwen, F X

    2000-01-01

    The production of adequate and safe drinking water is a high priority issue for safeguarding the health and well-being of humans all over the world. Traditionally, microbiological quality of drinking water has been the main concern, but over the last decades the attention of the general public and health officials on the importance of chemical quality and the threat of chemical pollutants have increased with the increase of our knowledge on the hazards of chemical substances. There are many sources of contamination of drinking water. Broadly they can be divided into two categories: contaminants originating from surface and groundwater, and contaminants used or formed during the treatment and distribution of drinking water. Contaminants in surface and groundwater can range from natural substances such as arsenic and manganese leaching from soil, to contaminants introduced by human activities, such as run-off from agricultural activities, controlled discharge from sewage treatment works and industrial plants, and uncontrolled discharges or leakage from landfill sites and from chemical accidents. Disinfectants and disinfectant by-products are well known contaminants resulting from the processes used by the drinking water industry for the treatment and distribution of water. The basic question in the production of drinking water is how to rid drinking water of potentially dangerous microorganisms and chemicals without introducing new hazards that might pose new and different threats to human health. It is the responsibility of toxicologists to provide risk assessments for chemical pollutants and to derive guidelines or standards for drinking water quality below which no significant health risk is encountered, to assure consumers that drinking water is safe and can be consumed without any risk. This paper will focus on the toxicological procedures used by the World Health Organization to derive guideline values for chemical compounds in drinking water, and will touch

  1. Application of DVC-FISH method in tracking Escherichia coli in drinking water distribution networks

    Directory of Open Access Journals (Sweden)

    L. Mezule

    2013-04-01

    Full Text Available Sporadic detection of live (viable Escherichia coli in drinking water and biofilm with molecular methods but not with standard plate counts has raised concerns about the reliability of this indicator in the surveillance of drinking water safety. The aim of this study was to determine spatial distribution of different viability forms of E. coli in a drinking water distribution system which complies with European Drinking Water Directive (98/83/EC. For two years coupons (two week old and pre-concentrated (100 times with ultrafilters water samples were collected after treatment plants and from four sites in the distribution network at several distances. The samples were analyzed for total, viable (able to divide as DVC-FISH positive and cultivable E. coli. The results showed that low numbers of E. coli enters the distribution sytem from the treatment plants and tend to accumulate in the biofilm of water distribution system. Almost all of the samples contained metabolically active E. coli in the range of 1 to 50 cells per litre or cm2 which represented approximately 53% of all E. coli detected. The amount of viable E. coli significantly increased into the network irrespective of the season. The study has shown that DVC-FISH method in combination with water pre-concentration and biofilm sampling allows to better understand the behaviour of E. coli in water distribution networks, thus, it provides new evidences for water safety control.

  2. 75 FR 48329 - Tribal Drinking Water Operator Certification Program

    Science.gov (United States)

    2010-08-10

    ... AGENCY Tribal Drinking Water Operator Certification Program AGENCY: Environmental Protection Agency (EPA... Water Operator Certification Program, effective October 1, 2010. The program enables qualified drinking..., operators learn how to supply drinking water that meets national standards and gain understanding of...

  3. Diversity and antibiotic resistance in Pseudomonas spp. from drinking water.

    Science.gov (United States)

    Vaz-Moreira, Ivone; Nunes, Olga C; Manaia, Célia M

    2012-06-01

    Pseudomonas spp. are common inhabitants of aquatic environments, including drinking water. Multi-antibiotic resistance in clinical isolates of P. aeruginosa is widely reported and deeply characterized. However, the information regarding other species and environmental isolates of this genus is scant. This study was designed based on the hypothesis that members of the genus Pseudomonas given their high prevalence, wide distribution in waters and genetic plasticity can be important reservoirs of antibiotic resistance in drinking water. With this aim, the diversity and antibiotic resistance phenotypes of Pseudomonas isolated from different drinking water sources were evaluated. The genotypic diversity analyses were based on six housekeeping genes (16S rRNA, rpoD, rpoB, gyrB, recA and ITS) and on pulsed field gel electrophoresis. Susceptibility to 21 antibiotics of eight classes was tested using the ATB PSE EU (08) and disk diffusion methods. Pseudomonas spp. were isolated from 14 of the 32 sampled sites. A total of 55 non-repetitive isolates were affiliated to twenty species. Although the same species were isolated from different sampling sites, identical genotypes were never observed in distinct types of water (water treatment plant/distribution system, tap water, cup fillers, biofilm, and mineral water). In general, the prevalence of antibiotic resistance was low and often the resistance patterns were related with the species and/or the strain genotype. Resistance to ticarcillin, ticarcillin with clavulanic acid, fosfomycin and cotrimoxazol were the most prevalent (69-84%). No resistance to piperacillin, levofloxacin, ciprofloxacin, tetracycline, gentamicin, tobramycin, amikacin, imipenem or meropenem was observed. This study demonstrates that Pseudomonas spp. are not so widespread in drinking water as commonly assumed. Nevertheless, it suggests that water Pseudomonas can spread acquired antibiotic resistance, preferentially via vertical transmission.

  4. Caffeinated soft drinks reduce bacterial prevalence in voice prosthetic biofilms

    NARCIS (Netherlands)

    Free, RH; Elving, GJ; Van der Mei, HC; Van Weissenbruch, R; Albers, FWJ; Busscher, HJ

    2000-01-01

    Laryngectomized patients use indwelling silicone rubber voice prostheses, placed in a surgically created fistula in between the trachea and the esophagus, for voice and speech rehabilitation. At the esophageal side, these voice prostheses rapidly become colonized by a thick biofilm consisting of a v

  5. Smart Water: Energy-Water Optimization in Drinking Water Systems

    Science.gov (United States)

    This project aims to develop and commercialize a Smart Water Platform – Sensor-based Data-driven Energy-Water Optimization technology in drinking water systems. The key technological advances rely on cross-platform data acquisition and management system, model-based real-time sys...

  6. Removal of Dental Biofilms with an Ultrasonically Activated Water Stream.

    Science.gov (United States)

    Howlin, R P; Fabbri, S; Offin, D G; Symonds, N; Kiang, K S; Knee, R J; Yoganantham, D C; Webb, J S; Birkin, P R; Leighton, T G; Stoodley, P

    2015-09-01

    Acidogenic bacteria within dental plaque biofilms are the causative agents of caries. Consequently, maintenance of a healthy oral environment with efficient biofilm removal strategies is important to limit caries, as well as halt progression to gingivitis and periodontitis. Recently, a novel cleaning device has been described using an ultrasonically activated stream (UAS) to generate a cavitation cloud of bubbles in a freely flowing water stream that has demonstrated the capacity to be effective at biofilm removal. In this study, UAS was evaluated for its ability to remove biofilms of the cariogenic pathogen Streptococcus mutans UA159, as well as Actinomyces naeslundii ATCC 12104 and Streptococcus oralis ATCC 9811, grown on machine-etched glass slides to generate a reproducible complex surface and artificial teeth from a typodont training model. Biofilm removal was assessed both visually and microscopically using high-speed videography, confocal scanning laser microscopy (CSLM), and scanning electron microscopy (SEM). Analysis by CSLM demonstrated a statistically significant 99.9% removal of S. mutans biofilms exposed to the UAS for 10 s, relative to both untreated control biofilms and biofilms exposed to the water stream alone without ultrasonic activation (P biofilm removal. The UAS was also highly effective at S. mutans, A. naeslundii, and S. oralis biofilm removal from machine-etched glass and S. mutans from typodont surfaces with complex topography. Consequently, UAS technology represents a potentially effective method for biofilm removal and improved oral hygiene.

  7. Investigation of drinking water quality in Kosovo.

    Science.gov (United States)

    Berisha, Fatlume; Goessler, Walter

    2013-01-01

    In the recent years, not much environmental monitoring has been conducted in the territory of Kosovo. This study represents the first comprehensive monitoring of the drinking water situation throughout most of the territory of Kosovo. We present the distribution of major and minor trace elements in drinking water samples from Kosovo. During our study we collected 951 samples from four different sources: private-bored wells; naturally flowing artesian water; pumped-drilled wells; and public water sources (tap water). The randomly selected drinking water samples were investigated by routine water analyses using inductively coupled plasma mass spectrometry (ICPMS) for 32 elements (Li, Be, B, Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Rb, Sr, Mo, Ag, Cd, Sn, Sb, Te, Ba, Tl, Pb, Bi, Th, U). Even though there are set guidelines for elemental exposure in drinking water worldwide, in developing countries, such as Kosovo, the lack of monitoring drinking water continues to be an important health concern. This study reports the concentrations of major and minor elements in the drinking water in Kosovo. Additionally, we show the variation of the metal concentration within different sources. Of the 15 regulated elements, the following five elements: Mn, Fe, Al, Ni, As, and U were the elements which most often exceeded the guidelines set by the EU and/or WHO.

  8. 3D Chlorine and Monochloramine Penetration and Nitrifying Biofilm Activity and Viability: Periodic Chlorine Switch Implications

    Science.gov (United States)

    Biofilm formation in drinking water distribution systems has been associated with water quality degradation and may result in non-compliance with existing regulations. United States water utilities report biofilm survival and regrowth despite disinfectant presence, and systems t...

  9. Influence of hydraulic regimes on bacterial community structure and composition in an experimental drinking water distribution system

    OpenAIRE

    Douterelo, I.; Sharpe, R.L.; Boxall, J.B.

    2011-01-01

    Microbial biofilms formed on the inner-pipe surfaces of drinking water distribution systems (DWDS) can alter drinking water quality, particularly if they are mechanically detached from the pipe wall to the bulk water, such as due to changes in hydraulic conditions. Results are presented here from applying 454 pyrosequencing of the 16S ribosomal RNA (rRNA) gene to investigate the influence of different hydrological regimes on bacterial community structure and to study the potential mobilisatio...

  10. 30 CFR 71.602 - Drinking water; distribution.

    Science.gov (United States)

    2010-07-01

    ... resistant materials. The containers shall be marked with the words “Drinking Water.” ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drinking water; distribution. 71.602 Section 71... Drinking Water § 71.602 Drinking water; distribution. (a) Water shall be piped or transported in...

  11. 30 CFR 71.603 - Drinking water; dispensing requirements.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drinking water; dispensing requirements. 71.603... COAL MINES Drinking Water § 71.603 Drinking water; dispensing requirements. (a) Water shall be dispensed through a drinking fountain or from a water storage container with an adequate supply of...

  12. Microbial quality of drinking water from groundtanks and tankers at ...

    African Journals Online (AJOL)

    Microbial quality of drinking water from groundtanks and tankers at source ... and lower educational standard were associated with poorer water quality, ... Keywords: drinking water; point of use; water quality; water quantity; hygiene; sanitation ...

  13. Radioactive isotopes in Danish drinking water

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Sven P. [Risoe National Lab., Roskilde (Denmark)

    2006-08-31

    A screening investigation of radioactivity in Danish drinking water has been carried out during 2001-2003. Samples of drinking water were collected from 296 water supplies representing more than 40% of the water delivered from water works in the country. Total alpha and total beta radioactivity was determined in the samples and compared with screening levels of 0.1 Bq/l total alpha and 1 Bq/l total beta radioactivity. The levels for total beta radioactivity were met in all the water works while total alpha radioactivity exceeded the screening levels for 13 water supplies. Further investigations were carried out for the water works with concentrations of alpha radioactivity above the screening levels in Ebeltoft, Grenae and Frederikssund to estimate the total indicative dose from the water. The elevated levels were found to be due to uranium in the water from individual boreholes. Radiation doses from consumption of water at these uranium levels are estimated to be well below the total indicative dose of 0.1 mSv/y specified in the Drinking Water Directive Groundwater used for drinking water was collected from different types of geological structures including bed rock and areas with potentially elevated levels of natural radioactivity. Also in these cases the concentrations of radioactivity were sufficiently low to meet the requirements in the Drinking Water Directive. In view of the results it seems probable that the risk of finding drinking water in Denmark with unacceptable concentrations of radioactivity is very small. Therefore there is no need for further radiological investigations of the Danish water supply based on natural groundwaters. (au)

  14. US Forest Service Surface Drinking Water Importance

    Data.gov (United States)

    US Forest Service, Department of Agriculture — A map service on the www depicting watershed indexes to help identify areas of interest for protecting surface drinking water quality. The dataset depicted in this...

  15. Drinking Water Mapping Application (DWMA) - Public Version

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Drinking Water Mapping Application (DWMA) is a web-based geographic information system (GIS) that enhances the capabilities to identify major contaminant risks...

  16. Drinking Water Mapping Application (DWMA) - Public Version

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Drinking Water Mapping Application (DWMA) is a web-based geographic information system (GIS) that enhances the capabilities to identify major contaminant risks...

  17. ALTERNATIVE DISINFECTANTS FOR DRINKING WATER TREATMENT

    Science.gov (United States)

    During a one-year study at Jefferson Parish, Louisiana the chemical, microbiological, and mutagenic effects of using the major drinking water disinfectants (chlorine, chlorine dioxide, chloramine, ozone) were evaluated. ests were performed on samples collected from various treatm...

  18. Drinking Water Microbiome as a Screening Tool for Nitrification in Chloraminated Drinking Water Distribution Systems

    Science.gov (United States)

    Many water utilities in the US using chloramine as disinfectant treatment in their distribution systems have experienced nitrification episodes, which detrimentally impact the water quality. A chloraminated drinking water distribution system (DWDS) simulator was operated throug...

  19. Biofilms as bioindicators of mercury exposure in surface waters

    Science.gov (United States)

    Le Faucheur, S.; Dranguet, P.; Freiburghaus, A.; Slaveykova, V. I.; Carmen, M.

    2016-12-01

    Biofilms are communities of microorganisms living in shallow waters, which possess several interesting characteristics to be a good bioindicator, i.e. ubiquitous, easy to collect, integrator of the quality of their ambient environment and sensitive to pollutants. Our work investigated whether biofilm could be used as a bioindicator of Hg contamination in natural waters and explore the links between ambient Hg concentrations, its bioaccumulation and biofilm composition. To that end, field- and lab-based experiments were performed with biofilm grown on artificial substrata in either Hg-impacted waters and in microcosms spiked with Hg. The field experiments were performed in contrasted environments: the Olt River (Romania) impacted by chloro-alkali releases and the lagoon of Venice (Italy) affected by urban, industrial and agricultural activities. The field studies were complemented with microcosm experiments using Geneva Lake water enriched with Hg (13 pM to 1.4 nM). Bioaccumulated inorganic HgII and methylmercury (CH3Hg) in biofilms were measured w/o cysteine washing step to assess the total and intracellular Hg content. Biofilm composition was examined from gene to community levels using several techniques, notably qPCR, epifluorescent microscopy and pyrosequencing. In parallel the physico-chemical parameters of the ambient waters (pH, anion/cation and dissolved organic matter concentrations) were well characterized and dissolved Hg concentrations measured. Commercially available DGTs for Hg were additionally used in the lagoon of Venice. The main findings of the study can be summarized as follows: (i) accumulation of Hg in biofilms well correlates with ambient Hg concentration in a specific environment, but (ii) that bioaccumulation highly depends of biofilm composition, with bacterial-dominated biofilms having higher uptake rate constants than algal-dominated biofilms, and (iii) Hg exposure at environmental low concentrations (pM levels) strongly impacts algal

  20. Drinking water quality monitoring using trend analysis.

    Science.gov (United States)

    Tomperi, Jani; Juuso, Esko; Eteläniemi, Mira; Leiviskä, Kauko

    2014-06-01

    One of the common quality parameters for drinking water is residual aluminium. High doses of residual aluminium in drinking water or water used in the food industry have been proved to be at least a minor health risk or even to increase the risk of more serious health effects, and cause economic losses to the water treatment plant. In this study, the trend index is developed from scaled measurement data to detect a warning of changes in residual aluminium level in drinking water. The scaling is based on monotonously increasing, non-linear functions, which are generated with generalized norms and moments. Triangular episodes are classified with the trend index and its derivative. The severity of the situations is evaluated by deviation indices. The trend episodes and the deviation indices provide good tools for detecting changes in water quality and for process control.

  1. Irrigation waters and pipe-based biofilms as sources for antibiotic-resistant bacteria.

    Science.gov (United States)

    Blaustein, Ryan A; Shelton, Daniel R; Van Kessel, Jo Ann S; Karns, Jeffrey S; Stocker, Matthew D; Pachepsky, Yakov A

    2016-01-01

    The presence of antibiotic-resistant bacteria in environmental surface waters has gained recent attention. Wastewater and drinking water distribution systems are known to disseminate antibiotic-resistant bacteria, with the biofilms that form on the inner-surfaces of the pipeline as a hot spot for proliferation and gene exchange. Pipe-based irrigation systems that utilize surface waters may contribute to the dissemination of antibiotic-resistant bacteria in a similar manner. We conducted irrigation events at a perennial stream on a weekly basis for 1 month, and the concentrations of total heterotrophic bacteria, total coliforms, and fecal coliforms, as well as the concentrations of these bacterial groups that were resistant to ampicillin and tetracycline, were monitored at the intake water. Prior to each of the latter three events, residual pipe water was sampled and 6-in. sections of pipeline (coupons) were detached from the system, and biofilm from the inner-wall was removed and analyzed for total protein content and the above bacteria. Isolates of biofilm-associated bacteria were screened for resistance to a panel of seven antibiotics, representing five antibiotic classes. All of the monitored bacteria grew substantially in the residual water between irrigation events, and the biomass of the biofilm steadily increased from week to week. The percentages of biofilm-associated isolates that were resistant to antibiotics on the panel sometimes increased between events. Multiple-drug resistance was observed for all bacterial groups, most often for fecal coliforms, and the distributions of the numbers of antibiotics that the total coliforms and fecal coliforms were resistant to were subject to change from week to week. Results from this study highlight irrigation waters as a potential source for antibiotic-resistant bacteria, which can subsequently become incorporated into and proliferate within irrigation pipe-based biofilms.

  2. Potential impacts of changing supply-water quality on drinking water distribution: A review.

    Science.gov (United States)

    Liu, Gang; Zhang, Ya; Knibbe, Willem-Jan; Feng, Cuijie; Liu, Wentso; Medema, Gertjan; van der Meer, Walter

    2017-06-01

    Driven by the development of water purification technologies and water quality regulations, the use of better source water and/or upgraded water treatment processes to improve drinking water quality have become common practices worldwide. However, even though these elements lead to improved water quality, the water quality may be impacted during its distribution through piped networks due to the processes such as pipe material release, biofilm formation and detachment, accumulation and resuspension of loose deposits. Irregular changes in supply-water quality may cause physiochemical and microbiological de-stabilization of pipe material, biofilms and loose deposits in the distribution system that have been established over decades and may harbor components that cause health or esthetical issues (brown water). Even though it is clearly relevant to customers' health (e.g., recent Flint water crisis), until now, switching of supply-water quality is done without any systematic evaluation. This article reviews the contaminants that develop in the water distribution system and their characteristics, as well as the possible transition effects during the switching of treated water quality by destabilization and the release of pipe material and contaminants into the water and the subsequent risks. At the end of this article, a framework is proposed for the evaluation of potential transition effects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Analysis of black fungal biofilms occurring at domestic water taps. I: compositional analysis using Tag-Encoded FLX Amplicon Pyrosequencing.

    Science.gov (United States)

    Heinrichs, Guido; Hübner, Iris; Schmidt, Carsten K; de Hoog, G Sybren; Haase, Gerhard

    2013-06-01

    Mass growth of dark fungal biofilms on water taps and associated habitats was observed in various German drinking water distribution systems recently. Customers of affected drinking water systems are anxious about potential and unknown health risks. These environments are known to harbour a fungal flora also comprising a variety of fungal opportunists that are well known to cause superficial mycoses in humans (Exophiala equina, Exophiala lecanii-corni) but are not known to establish dark biofilms so far. To gain profound insight on composition of respective biofilms, a metagenomic approach using Tag-Encoded FLX Amplicon Pyrosequencing (TEFAP) of the ribosomal internal transcribed spacer 2 region in comparison with a classical cultivation approach using Sabouraud agar with chloramphenicol and erythritol-chloramphenicol-agar was performed. E. lecanii-corni was found to be the major component in 10 of 13 biofilms analysed independently of the method used. Alternaria sp., E. equina, Fusarium spp. and Ochroconis spp. were also relatively abundant. As expected, TEFAP usually revealed a higher diversity than the cultivation approaches. For example, opportunistic species like Candida albicans or Exophiala dermatitidis were detected in very low amounts. In conclusion, TEFAP turned out to be a promising and powerful tool for the semi-quantitative analysis of fungal biofilms. Referring to relevant literature, potential biological hazards caused by fungi of the dark biofilms can be regarded as low.

  4. Emergency Disinfection of Drinking Water

    Science.gov (United States)

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

  5. Safe Drinking Water Information System (SDWIS) Surface Water Intakes

    Data.gov (United States)

    U.S. Environmental Protection Agency — This is a point feature dataset showing the locations of surface water intakes. These intake locations are part of the safe drinking water information system...

  6. Linking nitrifying biofilm characteristics and nitrification performance in moving-bed biofilm reactors for polluted raw water pretreatment.

    Science.gov (United States)

    Zhang, Shuangfu; Wang, Yayi; He, Weitao; Xing, Meiyan; Wu, Min; Yang, Jian; Gao, Naiyun; Sheng, Guangyao; Yin, Daqiang; Liu, Shanhu

    2013-10-01

    Biofilm physiology was characterized by four biofilm constituents, i.e., polysaccharides, proteins (PN), humic-like substances and phospholipids (PL), for the first time to explore the relationships between biofilm characteristics and nitrification performance in moving-bed biofilm reactors (MBBRs) designed for pretreatment of polluted raw surface water for potable supply. The biofilm compositions depended highly on the balance of microbial decay and nitrification processes. The increased ammonia loading greatly regulated the community structure, promoting the dominance of nitrifiers and their proportions in the nitrifying biofilm. Nitrification rate and activity correlated linearly with the fractions of volatile solids (VS), PN and PL, which were related to nitrification processes in the biofilm. The specific biofilm activity demonstrated an exponential-asymptotic relationship with ratios of PN/VS and PL/VS. Thus, analyzing biofilm characteristics can be valid for estimating nitrification performance in MBBRs, and may offer engineers with basis to optimize MBBR design and operation.

  7. Small Drinking Water Systems Research and Development

    Science.gov (United States)

    In the United States, there are 152,002 public water systems (PWS) in operation. Of these, 97% are considered small systems under the Safe Drinking Water Act (SDWA)—meaning they serve 10,000 or fewer people. While many of these small systems consistently provide safe, relia...

  8. Biofilm development on metal surfaces in tropical marine waters

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, F.P.; Bhosle, N.B.

    environments. However, little is known about biofilm bacteria developed on metal surfaces, especially immersed in tropical marine waters. Similarly, not much is known about the nature of organic matter deposited on the surfaces over the period of immersion...

  9. Influence of hydraulic regimes on bacterial community structure and composition in an experimental drinking water distribution system.

    Science.gov (United States)

    Douterelo, I; Sharpe, R L; Boxall, J B

    2013-02-01

    Microbial biofilms formed on the inner-pipe surfaces of drinking water distribution systems (DWDS) can alter drinking water quality, particularly if they are mechanically detached from the pipe wall to the bulk water, such as due to changes in hydraulic conditions. Results are presented here from applying 454 pyrosequencing of the 16S ribosomal RNA (rRNA) gene to investigate the influence of different hydrological regimes on bacterial community structure and to study the potential mobilisation of material from the pipe walls to the network using a full scale, temperature-controlled experimental pipeline facility accurately representative of live DWDS. Analysis of pyrosequencing and water physico-chemical data showed that habitat type (water vs. biofilm) and hydraulic conditions influenced bacterial community structure and composition in our experimental DWDS. Bacterial community composition clearly differed between biofilms and bulk water samples. Gammaproteobacteria and Betaproteobacteria were the most abundant phyla in biofilms while Alphaproteobacteria was predominant in bulk water samples. This suggests that bacteria inhabiting biofilms, predominantly species belonging to genera Pseudomonas, Zooglea and Janthinobacterium, have an enhanced ability to express extracellular polymeric substances to adhere to surfaces and to favour co-aggregation between cells than those found in the bulk water. Highest species richness and diversity were detected in 28 days old biofilms with this being accentuated at highly varied flow conditions. Flushing altered the pipe-wall bacterial community structure but did not completely remove bacteria from the pipe walls, particularly under highly varied flow conditions, suggesting that under these conditions more compact biofilms were generated. This research brings new knowledge regarding the influence of different hydraulic regimes on the composition and structure of bacterial communities within DWDS and the implication that this

  10. Basic Information about Chloramines and Drinking Water Disinfection

    Science.gov (United States)

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

  11. 30 CFR 71.601 - Drinking water; quality.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drinking water; quality. 71.601 Section 71.601... Water § 71.601 Drinking water; quality. (a) Potable water provided in accordance with the provisions of § 71.600 shall meet the applicable minimum health requirements for drinking water established by the...

  12. Anencephalus, drinking water, geomagnetism and cosmic radiation.

    Science.gov (United States)

    Archer, V E

    1979-01-01

    The mortality rates from anencephalus from 1950-1969 in Canadian cities are shown to be strongly correlated with city growth rate and with horizontal geomagnetic flux, which is directly related to the intensity of cosmic radiation. They are also shown to have some association with the magnesium content of drinking water. Prior work with these data which showed associations with magnesium in drinking water, mean income, latitude and longitude was found to be inadequate because it dismissed the observed geographic associations as having little biological meaning, and because the important variables of geomagnetism and city growth rate were overlooked.

  13. Removal of Foodborne Pathogen Biofilms by Acidic Electrolyzed Water

    Directory of Open Access Journals (Sweden)

    Qiao Han

    2017-06-01

    Full Text Available Biofilms, which are complex microbial communities embedded in the protective extracellular polymeric substances (EPS, are difficult to remove in food production facilities. In this study, the use of acidic electrolyzed water (AEW to remove foodborne pathogen biofilms was evaluated. We used a green fluorescent protein-tagged Escherichia coli for monitoring the efficiency of AEW for removing biofilms, where under the optimal treatment conditions, the fluorescent signal of cells in the biofilm disappeared rapidly and the population of biofilm cells was reduced by more than 67%. Additionally, AEW triggered EPS disruption, as indicated by the deformation of the carbohydrate C-O-C bond and deformation of the aromatic rings in the amino acids tyrosine and phenylalanine. These deformations were identified by EPS chemical analysis and Raman spectroscopic analysis. Scanning electron microscopy (SEM images confirmed that the breakup and detachment of biofilm were enhanced after AEW treatment. Further, AEW also eradicated biofilms formed by both Gram-negative bacteria (Vibrio parahaemolyticus and Gram-positive bacteria (Listeria monocytogenes and was observed to inactivate the detached cells which are a potential source of secondary pollution. This study demonstrates that AEW could be a reliable foodborne pathogen biofilm disrupter and an eco-friendly alternative to sanitizers traditionally used in the food industry.

  14. Private drinking water quality in rural Wisconsin.

    Science.gov (United States)

    Knobeloch, Lynda; Gorski, Patrick; Christenson, Megan; Anderson, Henry

    2013-03-01

    Between July 1, 2007, and December 31, 2010, Wisconsin health departments tested nearly 4,000 rural drinking water supplies for coliform bacteria, nitrate, fluoride, and 13 metals as part of a state-funded program that provides assistance to low-income families. The authors' review of laboratory findings found that 47% of these wells had an exceedance of one or more health-based water quality standards. Test results for iron and coliform bacteria exceeded safe limits in 21% and 18% of these wells, respectively. In addition, 10% of the water samples from these wells were high in nitrate and 11% had an elevated result for aluminum, arsenic, lead, manganese, or strontium. The high percentage of unsafe test results emphasizes the importance of water quality monitoring to the health of nearly one million families including 300,000 Wisconsin children whose drinking water comes from a privately owned well.

  15. Climate change influence on drinking water quality

    Science.gov (United States)

    Kovacs, Melinda Haydee; Ristoiu, Dumitru; Voica, Cezara; Moldovan, Zaharie

    2013-11-01

    Although it are quite well known the possible effects of climate changes on surface waters availability and their hydrological risks, their consequences on drinking water quality is not well defined yet. Disinfection agents (as Cl2, O3, etc.) or multiple combinations of them for water treatment and disinfection purposes are applied by water treatment plants at worldwide level. Unfortunately, besides the benefits of these processes were also highlighted some undesirable effects such as formation of several disinfection by-products (DBPs) after reaction of disinfection agent with natural organic matter (NOM) from water body. DBPs formation in drinking water, suspected to posses adverse health effects to humans are strongly regulated in our days. Thus, throughout this study kinetics experiments both the main physicochemical factors that influencing the quality of drinking waters were evaluated as well how they act through possible warming or the consequences of extreme events. Increasing water temperatures with 1 - 5 °C above its normal value has showed that NOMs are presented in higher amount which led to the need for greater amount of disinfectant agent (5 - 15 %). Increasing the amount of disinfecting agent resulted in the formation of DBPs in significantly higher concentrations (between 5 - 30 %).

  16. Inactivation of the biofilm by the air plasma containing water

    Science.gov (United States)

    Suganuma, Ryota; Yasuoka, Koichi; Yasuoka Takeuchi lab Team

    2014-10-01

    Biofilms are caused by environmental degradation in food factory and medical facilities. Inactivation of biofilm has the method of making it react to chemicals including chlorine, hydrogen peroxide, and ozone. Although inactivation by chemicals has the problem that hazardous property of a residual substance and hydrogen peroxide have slow reaction velocity. We achieved advanced oxidation process (AOP) with air plasma. Hydrogen peroxide and ozone, which were used for the formation of OH radicals in our experiment, were able to be generated selectively by adjusting the amount of water supplied to the plasma. We inactivated Pseudomonas aeruginosa biofilm in five minutes with OH radicals generated by using hydrogen peroxide and ozone.

  17. Transmission of Helicobacter pylori and the role of water and biofilms.

    Science.gov (United States)

    Percival, Steven L; Thomas, John G

    2009-09-01

    Documented evidence relating to the survival of Helicobacter pylori outside the gastric niche is extremely limited. To date the primary transmission routes of H. pylori have yet to be confirmed and when this is achieved preventive infection control measures can be implemented to reduce and ultimately prevent human infection from this pathogen. There is mounting evidence which suggests that the prevalence of H. pylori infection has a strong correlation with access to clean water, suggesting a transmission route to the host. However, there are no established culture methods for the detection of viable H. pylori in the environment, in particular drinking water supplies, preventing the development of true epidemiological and risk assessments. The aim of this review is to highlight the available data to date that suggests drinking water and possible survival in biofilms as a probable transmission mode for H. pylori.

  18. A sub-tank water-saving drinking water station

    Science.gov (United States)

    Zhang, Ting

    2017-05-01

    "Thousands of boiling water" problem has been affecting people's quality of life and good health, and now most of the drinking fountains cannot effectively solve this problem, at the same time, ordinary drinking water also has high energy consumption, there are problems such as yin and yang water. Our newly designed dispenser uses a two-tank heating system. Hot water after heating, into the insulation tank for insulation, when the water tank in the water tank below a certain water level, the cold water and then enter the heating tank heating. Through the water flow, tank volume and other data to calculate the time required for each out of water, so as to determine the best position of the water level control, summed up the optimal program, so that water can be continuously uninterrupted supply. Two cans are placed up and down the way, in the same capacity on the basis of the capacity of the container, the appropriate to reduce its size, and increase the bottom radius, reduce the height of its single tank to ensure that the overall height of two cans compared with the traditional single change. Double anti-dry design, to ensure the safety of the use of drinking water. Heating tank heating circuit on and off by the tank of the float switch control, so that the water heating time from the tank water level control, to avoid the "thousands of boiling water" generation. The entry of cold water is controlled by two solenoid valves in the inlet pipe, and the opening and closing of the solenoid valve is controlled by the float switch in the two tanks. That is, the entry of cold water is determined by the water level of the two tanks. By designing the control scheme cleverly, Yin and yang water generation. Our design completely put an end to the "thousands of boiling water", yin and yang water, greatly improving the drinking water quality, for people's drinking water safety provides a guarantee, in line with the concept of green and healthy development. And in the small

  19. Polyfluorinated chemicals in European surface waters, ground- and drinking waters

    NARCIS (Netherlands)

    Eschauzier, C.; de Voogt, P.; Brauch, H.-J.; Lange, F.T.; Knepper, T.P.; Lange, F.T.

    2012-01-01

    Polyfluorinated chemicals (PFCs), especially short chain fluorinated alkyl sulfonates and carboxylates, are ubiquitously found in the environment. This chapter aims at giving an overview of PFC concentrations found in European surface, ground- and drinking waters and their behavior during convention

  20. Polyfluorinated chemicals in European surface waters, ground- and drinking waters

    NARCIS (Netherlands)

    Eschauzier, C.; de Voogt, P.; Brauch, H.-J.; Lange, F.T.; Knepper, T.P.; Lange, F.T.

    2012-01-01

    Polyfluorinated chemicals (PFCs), especially short chain fluorinated alkyl sulfonates and carboxylates, are ubiquitously found in the environment. This chapter aims at giving an overview of PFC concentrations found in European surface, ground- and drinking waters and their behavior during

  1. Drinking Water. The Food Guide Pyramid.

    Science.gov (United States)

    Frost, Helen

    This booklet for young children is part of a series that supports national science standards related to physical health and nutrition, describing and illustrating the importance of drinking water. Colorful photographs support early readers in understanding the text. The repetition of words and phrases helps early readers learn new words. The book…

  2. CONTROL OF ZOONOTIC DISEASES IN DRINKING WATER

    Science.gov (United States)

    For over a century, the process of providing hygienically safe drinking water has focused on utilizing treatment processes to provide barriers to the passage of infectious disease-causing organisms to humans. This concept is often considered the cornerstone of sanitary engineerin...

  3. Microfiltration and Ultrafiltration Membranes for Drinking Water

    Science.gov (United States)

    This article provides a concise and abbreviated summary of AWWA Manual of Practice M53, Microfiltration and Ultrafiltration Membranes for Drinking Water, to serve as a quick point of reference. For convenience, the article’s organization matches that of M53, as follows: • wate...

  4. Drinking Water. The Food Guide Pyramid.

    Science.gov (United States)

    Frost, Helen

    This booklet for young children is part of a series that supports national science standards related to physical health and nutrition, describing and illustrating the importance of drinking water. Colorful photographs support early readers in understanding the text. The repetition of words and phrases helps early readers learn new words. The book…

  5. Investigating the role of biofilms in trihalomethane formation in water distribution systems with a multicomponent model.

    Science.gov (United States)

    Abokifa, Ahmed A; Yang, Y Jeffrey; Lo, Cynthia S; Biswas, Pratim

    2016-11-01

    Biofilms are ubiquitous in the pipes of drinking water distribution systems (DWDSs), and recent experimental studies revealed that the chlorination of the microbial carbon associated with the biofilm contributes to the total disinfection by-products (DBPs) formation with distinct mechanisms from those formed from precursors derived from natural organic matter (NOM). A multiple species reactive-transport model was developed to explain the role of biofilms in DBPs formation by accounting for the simultaneous transport and interactions of disinfectants, organic compounds, and biomass. Using parameter values from experimental studies in the literature, the model equations were solved to predict chlorine decay and microbial regrowth dynamics in an actual DWDS, and trihalomethanes (THMs) formation in a pilot-scale distribution system simulator. The model's capability of reproducing the measured concentrations of free chlorine, suspended biomass, and THMs under different hydrodynamic and temperature conditions was demonstrated. The contribution of bacteria-derived precursors to the total THMs production was found to have a significant dependence on the system's hydraulics, seasonal variables, and the quality of the treated drinking water. Under system conditions that promoted fast bacterial re-growth, the transformation of non-microbial into microbial carbon DBP precursors by the biofilms showed a noticeable effect on the kinetics of THMs formation, especially when a high initial chlorine dose was applied. These conditions included elevated water temperature and high concentrations of nutrients in the influent water. The fraction of THMs formed from microbial sources was found to reach a peak of 12% of the total produced THMs under the investigated scenarios. The results demonstrated the importance of integrating bacterial regrowth dynamics in predictive DBPs formation models. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. On the way to identify microorganisms in drinking water distribution networks via DNA analysis of the gut content of freshwater isopods.

    Science.gov (United States)

    Mayer, Michael; Keller, Adrian; Szewzyk, Ulrich; Warnecke, Hans-Joachim

    2015-05-10

    Pure drinking water is the basis for a healthy society. In Germany the drinking water regulations demand for analysis of water via detection of certain microbiological parameters by cultivation only. However, not all prokaryotes can be detected by these standard methods. How to gain more and better information about the bacteria present in drinking water and its distribution systems? The biofilms in drinking water distribution systems are built by bacteria and therefore represent a valuable source of information about the species present. Unfortunately, these biofilms are badly accessible. We thus exploited the circumstance that a lot of metazoans graze the biofilms, so that the content of their guts partly reflects the respective biofilm biocenosis. Therefore, we collected omnivorous isopods, prepared their guts and examined and characterized their contents based on 16S und 18S rDNA analysis. These molecularbiological investigations provide a profound basis for the characterization of the biocenosis and thereby biologically assess the drinking water ecosystems. Combined with a thorough identification of the species and the knowledge of their habitats, this approach can provide useful indications for the assessment of drinking-water quality and the early detection of problems in the distribution system. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Integrated modeling of ozonation for optimization of drinking water treatment

    NARCIS (Netherlands)

    van der Helm, A.W.C.

    2007-01-01

    Drinking water treatment plants automation becomes more sophisticated, more on-line monitoring systems become available and integration of modeling environments with control systems becomes easier. This gives possibilities for model-based optimization. In operation of drinking water treatment

  8. Region 9 Drinking Water Wells (LD-SDWIS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — EPAâ??s Safe Drinking Water Information System (SDWIS) databases store information about drinking water. The federal version (SDWIS/FED) stores the information EPA...

  9. A drinking water quality framework for South Africa

    African Journals Online (AJOL)

    Quality Framework for South Africa to enable effective management of drinking water quality and the protection of public health. ... to monitor, manage, communicate and regulate drinking water quality. ... Inadequate WSA institutional capacity (staffing, funding, .... Although demonstrating compliance with regulatory limits.

  10. Sole Source Aquifer Program | Drinking Water in New ...

    Science.gov (United States)

    2017-07-06

    The Safe Drinking Water Act gives EPA the authority to designate aquifers which are the sole or principal drinking water source for an area, and which, if contaminated, would create a significant hazard to public health.

  11. Bacteriology of drinking water distribution systems: an integral and multidimensional review.

    Science.gov (United States)

    Liu, G; Verberk, J Q J C; Van Dijk, J C

    2013-11-01

    A drinking water distribution system (DWDS) is the final and essential step to supply safe and high-quality drinking water to customers. Biological processes, such as biofilm formation and detachment, microbial growth in bulk water, and the formation of loose deposits, may occur. These processes will lead to deterioration of the water quality during distribution. In extreme conditions, pathogens and opportunistic pathogens may proliferate and pose a health risk to consumers. It is, therefore, necessary to understand the bacteriology of DWDSs to develop effective strategies that can ensure the water quality at consumers' taps. The bacteriology of DWDSs, both the quantitative growth and the qualitative bacterial community, has attracted considerable research attention. However, the researchers have focused mainly on the pipe wall biofilm. In this review, DWDS bacteriology has been reviewed multidimensionally, including both the bacterial quantification and identification. For the first time, the available literature was reviewed with an emphasis on the subdivision of DWDS into four phases: bulk water, suspended solids, loose deposits, and pipe wall biofilm. Special concentration has been given to potential contribution of particulate matter: suspended particles and loose deposits. Two highlighted questions were reviewed and discussed: (1) where does most of the growth occur? And (2) what is the contribution of particle-associated bacteria to DWDS bacteriology and ecology? At the end of this review, recommendations were given based on the conclusion of this review to better understand the integral DWDS bacteriology.

  12. Improving Drinking Water Quality by Remineralisation.

    Science.gov (United States)

    Luptáková, Anna; Derco, Ján

    2015-01-01

    The reason of low mineral content in source water is its origin in poorly soluble mineral geological structures. There are many areas with very soft low-mineralised water around the world. All people involved in drinking water treatment as well as some public health experts and producers of chemicals used for water treatment may be interested in the study. Enrichment of drinking water by minerals including calcium and magnesium is very important particularly in regions where drinking water is prepared by desalination. The aim of this work was to study and intensify the recarbonization process. Half-calcined dolomite in combination with carbon dioxide constitutes the chemistry of the applied method. Advantages of using a fluidised bed reactor contributed also significantly to the process efficiency enhancement. Continuous input of carbon dioxide into the fluidised bed recarbonization reactor resulted in an increase in the recarbonization rate by about one order of magnitude compared with the process in without carbon dioxide addition. Very good fit of experimental data for hydrodynamic characteristics of fluidised bed was obtained using simple model based on the Richardson and Zaki expansion equation. The first order model describes kinetic data from the recarbonization process with a good accuracy. Higher recarbonization rates were observed with smaller particles of half-calcined dolomite.

  13. Microbial biogeography of drinking water: patterns in phylogenetic diversity across space and time.

    Science.gov (United States)

    Roeselers, Guus; Coolen, Jordy; van der Wielen, Paul W J J; Jaspers, Marco C; Atsma, Adrie; de Graaf, Bendert; Schuren, Frank

    2015-07-01

    In this study, we collected water from different locations in 32 drinking water distribution networks in the Netherlands and analysed the spatial and temporal variation in microbial community composition by high-throughput sequencing of 16S rRNA gene amplicons. We observed that microbial community compositions of raw source and processed water were very different for each distribution network sampled. In each network, major differences in community compositions were observed between raw and processed water, although community structures of processed water did not differ substantially from end-point tap water. End-point water samples within the same distribution network revealed very similar community structures. Network-specific communities were shown to be surprisingly stable in time. Biofilm communities sampled from domestic water metres varied distinctly between households and showed no resemblance to planktonic communities within the same distribution networks. Our findings demonstrate that high-throughput sequencing provides a powerful and sensitive tool to probe microbial community composition in drinking water distribution systems. Furthermore, this approach can be used to quantitatively compare the microbial communities to match end-point water samples to specific distribution networks. Insight in the ecology of drinking water distribution systems will facilitate the development of effective control strategies that will ensure safe and high-quality drinking water.

  14. The quality of drinking water in Poland

    Directory of Open Access Journals (Sweden)

    L. Kłos

    2015-05-01

    Full Text Available Introduction. An analysis of the drinking water quality and the degree of access to water supply and sewerage system in Poland was conducted. Materials and methods. Method of analysis of secondary statistical data was applied, mostly based on data available in the materials of the Central Statistical Office in Warsaw, the Waterworks Polish Chamber of Commerce in Bydgoszcz and the National Water Management in Warsaw. Result and discussion. 60 % of Poles do not trust to drink water without prior boiling. Water flowing from the taps, although widely available, is judged to be polluted, with too much fluorine or not having the appropriate consumer values (colour, smell and taste. The current water treatment systems can however improve them, although such a treatment, i.e. mainly through chlorination of water, deteriorates its quality in relation to pure natural water. The result is that fewer and fewer Poles drink water directly from the tap. They also less and less use tap water to cook food for which the bottled water is trusted more. Reason for that is that society does not trust the safety of the water supplied by the municipal water companies. The question thus is: Are they right? Tap water in Poland meets all standards since it is constantly monitored by the water companies and all relevant health services. Tap water supplied through the water supply system can be used without prior boiling. Studies have shown that only the operating parameters of water, suc h as taste, odour and hardness, are not satisfactory everywhere, different in each city, and sometimes in different districts of cities, often waking thoughts among users about its inappropriateness. The lowered water value can be easily improved at home through the use of filters. In conclusion, due to constant monitoring and investment in upgrading treatment processes, the quality of tap water has improved significantly in the last years. Conclusion. The results first allow assessing the

  15. A Drop to Drink. . .A Report on the Quality of Our Drinking Water.

    Science.gov (United States)

    Tait, Jack

    Basic information about the quality of our nation's drinking water is contained in this brochure. Written for the general public to familiarize them with the situation, it will also help them evaluate the state of the nation's drinking water as well as that of their own communities. The need to assure reliable sources of healthful drinking water…

  16. 21 CFR 520.2325a - Sulfaquinoxaline drinking water.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sulfaquinoxaline drinking water. 520.2325a Section... Sulfaquinoxaline drinking water. (a) Sponsor. See § 510.600(c) of this chapter for identification of the sponsors... tolerances. See § 556.685 of this chapter. (c) Conditions of use. It is used in drinking water as follows:...

  17. Health assessment of toluene in California drinking water

    Energy Technology Data Exchange (ETDEWEB)

    Reed, N.; Reed, W.; Beltran, L.; Li, R.; Encomienda, I.

    1989-03-08

    This report reviews existing literature pertinent to the health risk posed by the use of toluene-contaminated drinking water. Also included in the study is an estimate of the toluene exposure of California residents based on the most recent data on toluene concentrations in California drinking water supplies. The concentration of toluene in drinking water that may cause adverse health effects is delineated.

  18. Assessment of Drinking Water Quality from Bottled Water Coolers.

    Directory of Open Access Journals (Sweden)

    Marzieh Farhadkhani

    2014-05-01

    Full Text Available Drinking water quality can be deteriorated by microbial and toxic chemicals during transport, storage and handling before using by the consumer. This study was conducted to evaluate the microbial and physicochemical quality of drinking water from bottled water coolers.A total of 64 water samples, over a 5-month period in 2012-2013, were collected from free standing bottled water coolers and water taps in Isfahan. Water samples were analyzed for heterotrophic plate count (HPC, temperature, pH, residual chlorine, turbidity, electrical conductivity (EC and total organic carbon (TOC. Identification of predominant bacteria was also performed by sequence analysis of 16S rDNA.The mean HPC of water coolers was determined at 38864 CFU/ml which exceeded the acceptable level for drinking water in 62% of analyzed samples. The HPC from the water coolers was also found to be significantly (P < 0.05 higher than that of the tap waters. The statistical analysis showed no significant difference between the values of pH, EC, turbidity and TOC in water coolers and tap waters. According to sequence analysis eleven species of bacteria were identified.A high HPC is indicative of microbial water quality deterioration in water coolers. The presence of some opportunistic pathogens in water coolers, furthermore, is a concern from a public health point of view. The results highlight the importance of a periodic disinfection procedure and monitoring system for water coolers in order to keep the level of microbial contamination under control.

  19. Climate vulnerability of drinking water supplies

    Science.gov (United States)

    Selmeczi, Pál; Homolya, Emese; Rotárné Szalkai, Ágnes

    2016-04-01

    Extreme weather conditions in Hungary led to difficulties in drinking water management on diverse occasions in the past. Due to reduced water resources and the coexisting high demand for drinking water in dry summer periods the availability of a number of water supplies became insufficient therefore causing limitations in water access. In some other cases, as a result of floods and flash floods over karstic areas evolving in consequence of excessive precipitation, several water supplies had to be excluded in order to avoid the risk of infections. More frequent occurrence of extreme weather conditions and further possible changes in the future induce the necessity for an analysis of the vulnerability of drinking water resources to climate change. Since 95% of the total drinking water supply in Hungary originates from subsurface layers, significance of groundwater resources is outstanding. The aim of our work carried out in the frames of the NAGiS (National Adaptation Geo-information System) project was to build up a methodology for the study and determination of the vulnerability of drinking water supplies to climate. The task covered analyses of climatic parameters influencing drinking water supplies principally and hydrogeological characteristics of the geological media that significantly determines vulnerability. Effects on drinking water resources and their reduction or exclusion may imply societal and economic consequences therefore we extended the analyses to the investigation of possibilities concerning the adaptation capacity to changed conditions. We applied the CIVAS (Climate Impact and Vulnerability Assessment Scheme) model developed in the frames of the international climate research project CLAVIER (Climate Change and Variability: Impact on Central and Eastern Europe) to characterize climate vulnerability of drinking water supplies. The CIVAS model, being based on the combined evaluation of exposure, sensitivity and adaptability, provides a unified

  20. GLYPHOSATE REMOVAL FROM DRINKING WATER

    Science.gov (United States)

    Activated-carbon, oxidation, conventional-treatment, filtration, and membrane studies are conducted to determine which process is best suited to remove the herbicide glyphosate from potable water. Both bench-scale and pilot-scale studies are completed. Computer models are used ...

  1. GLYPHOSATE REMOVAL FROM DRINKING WATER

    Science.gov (United States)

    Activated-carbon, oxidation, conventional-treatment, filtration, and membrane studies are conducted to determine which process is best suited to remove the herbicide glyphosate from potable water. Both bench-scale and pilot-scale studies are completed. Computer models are used ...

  2. Quantifying Salmonella population dynamics in water and biofilms.

    Science.gov (United States)

    Sha, Qiong; Vattem, Dhiraj A; Forstner, Michael R J; Hahn, Dittmar

    2013-01-01

    Members of the bacterial genus Salmonella are recognized worldwide as major zoonotic pathogens often found to persist in non-enteric environments including heterogeneous aquatic biofilms. In this study, Salmonella isolates that had been detected repeatedly over time in aquatic biofilms at different sites in Spring Lake, San Marcos, Texas, were identified as serovars Give, Thompson, Newport and -:z10:z39. Pathogenicity results from feeding studies with the nematode Caenorhabditis elegans as host confirmed that these strains were pathogenic, with Salmonella-fed C. elegans dying faster (mean survival time between 3 and 4 days) than controls, i.e., Escherichia coli-fed C. elegans (mean survival time of 9.5 days). Cells of these isolates inoculated into water at a density of up to 10(6) ml(-1) water declined numerically by 3 orders of magnitude within 2 days, reaching the detection limit of our quantitative polymerase chain reaction (qPCR)-based quantification technique (i.e., 10(3) cells ml(-1)). Similar patterns were obtained for cells in heterogeneous aquatic biofilms developed on tiles and originally free of Salmonella that were kept in the inoculated water. Cell numbers increased during the first days to more than 10(7) cells cm(-2), and then declined over time. Ten-fold higher cell numbers of Salmonella inoculated into water or into biofilm resulted in similar patterns of population dynamics, though cells in biofilms remained detectable with numbers around 10(4) cells cm(-2) after 4 weeks. Independent of detectability by qPCR, samples of all treatments harbored viable salmonellae that resembled the inoculated isolates after 4 weeks of incubation. These results demonstrate that pathogenic salmonellae were isolated from heterogeneous aquatic biofilms and that they could persist and stay viable in such biofilms in high numbers for some time.

  3. [Human exposure to trihalomethanes in drinking water].

    Science.gov (United States)

    Tominaga, M Y; Midio, A F

    1999-08-01

    Halogenated hydrocarbon compounds, some of them recognized as carcinogenic to different animal species can be found in drinking water. Chloroform, bromodichloromethane, dibromochloromethane and bromoform are the most important trihalomethanes found in potable water. They are produced in natural waters during chlorinated desinfection by the halogenation of precursors, specially humic and fulvic compounds. The review, in the MEDLINE covers the period from 1974 to 1998, presents the general aspects of the formation of trihalomethanes, sources of human exposure and their toxicological meaning for exposed organisms: toxicokinetic disposition and spectrum of toxic effects (carcinogenic, mutagenic and teratogenic).

  4. Spatial distribution of Legionella pneumophila MLVA-genotypes in a drinking water system.

    Science.gov (United States)

    Rodríguez-Martínez, Sarah; Sharaby, Yehonatan; Pecellín, Marina; Brettar, Ingrid; Höfle, Manfred; Halpern, Malka

    2015-06-15

    Bacteria of the genus Legionella cause water-based infections, resulting in severe pneumonia. To improve our knowledge about Legionella spp. ecology, its prevalence and its relationships with environmental factors were studied. Seasonal samples were taken from both water and biofilm at seven sampling points of a small drinking water distribution system in Israel. Representative isolates were obtained from each sample and identified to the species level. Legionella pneumophila was further determined to the serotype and genotype level. High resolution genotyping of L. pneumophila isolates was achieved by Multiple-Locus Variable number of tandem repeat Analysis (MLVA). Within the studied water system, Legionella plate counts were higher in summer and highly variable even between adjacent sampling points. Legionella was present in six out of the seven selected sampling points, with counts ranging from 1.0 × 10(1) to 5.8 × 10(3) cfu/l. Water counts were significantly higher in points where Legionella was present in biofilms. The main fraction of the isolated Legionella was L. pneumophila serogroup 1. Serogroup 3 and Legionella sainthelensis were also isolated. Legionella counts were positively correlated with heterotrophic plate counts at 37 °C and negatively correlated with chlorine. Five MLVA-genotypes of L. pneumophila were identified at different buildings of the sampled area. The presence of a specific genotype, "MLVA-genotype 4", consistently co-occurred with high Legionella counts and seemed to "trigger" high Legionella counts in cold water. Our hypothesis is that both the presence of L. pneumophila in biofilm and the presence of specific genotypes, may indicate and/or even lead to high Legionella concentration in water. This observation deserves further studies in a broad range of drinking water systems to assess its potential for general use in drinking water monitoring and management.

  5. Drinking-water safety: challenges for community-managed systems.

    Science.gov (United States)

    Rizak, S; Hrudey, Steve E

    2008-01-01

    A targeted review of documented waterborne disease outbreaks over the past decades reveals some recurring themes that should be understood by drinking-water suppliers. Evidence indicates the outbreaks are often linked to some significant change in conditions that provides a sudden challenge to a water system. Severe weather events, such as heavy rainfall or runoff from snow melt, as well as treatment process and system changes, are common risk factors for drinking-water outbreaks. Failure to recognise warning signs and complacency are important contributors to drinking water becoming unsafe. Drinking-water suppliers must focus on competence and vigilance in maintaining effective multiple barriers appropriate to the challenges facing the drinking-water system. Understanding the risk factors and failure modes of waterborne disease outbreaks is an essential component for effective management of community drinking-water supplies and ensuring the delivery of safe drinking-water to consumers.

  6. Phosphorus limitation on bacterial regrowth in drinking water

    Institute of Scientific and Technical Information of China (English)

    SANG Jun-qiang; ZHANG Xi-hui; YU Guo-zhong; WANG Zhan-sheng

    2003-01-01

    Assimilable organic carbon (AOC) test and bacterial regrowth potential (BRP) analysis were used to investigate the effect of phosphorus on bacterial regrowth in the drinking water that was made from some raw water taken from a reservoir located in northern China. It was shown that AOC of the drinking water samples increased by 43.9%-59.6% and BRP increased by 100%-235% when 50 μg/L PO3-4-P(as NaH2 PO4 ) was added alone to the drinking water samples. This result was clear evidence of phosphorus limitation on bacteria regrowth in the drinking water. This investigation indicated the importance of phosphorus in ensuring biological stability of drinking water and offered a novel possible option to restrict microbial regrowth in drinking water distribution system by applying appropriate technologies to remove phosphorus efficiently from drinking water in China.

  7. Drinking Water Consequences Tools. A Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Pasqualini, Donatella [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-12

    In support of the goals of Department of Homeland Security’s (DHS) National Protection and Programs Directorate and the Federal Emergency Management Agency, the DHS Office of Science and Technology is seeking to develop and/or modify consequence assessment tools to enable drinking water systems owner/operators to estimate the societal and economic consequences of drinking water disruption due to the threats and hazards. This work will expand the breadth of consequence estimation methods and tools using the best-available data describing water distribution infrastructure, owner/assetlevel economic losses, regional-scale economic activity, and health. In addition, this project will deploy the consequence methodology and capability within a Web-based platform. This report is intended to support DHS effort providing a review literature review of existing assessment tools of water and wastewater systems consequences to disruptions. The review includes tools that assess water systems resilience, vulnerability, and risk. This will help to understand gaps and limitations of these tools in order to plan for the development of the next-generation consequences tool for water and waste water systems disruption.

  8. TRIHALOMETHANES IN THE DRINKING WATER OF TEHRAN

    Directory of Open Access Journals (Sweden)

    F.Vaezi

    1992-06-01

    Full Text Available Natural sources of water contain some halogenated organic compounds after disinfection by chlorine. Trihalomethanes are one group of the chlorination by products that suspected of being carcinogenic inhuman unfortunately, these compounds are in finished water of all treatment plants that use chlorine as a disinfectant. In this study, the concentration of total THMS of water treated in the water treatment plant No.1 of Tehran had been measured by spectrophotometric method, along the month of June, 1371. Results of experiments have shown that organic contents of Tehran drinking water were not considerable in the period of survey. The mean concentration of TTHMS in water samples is estimated to be 28 micrograms per liter and none of the analyzed samples was considered polluted.

  9. Water drinking as a treatment for orthostatic syndromes

    Science.gov (United States)

    Shannon, John R.; Diedrich, Andre; Biaggioni, Italo; Tank, Jens; Robertson, Rose Marie; Robertson, David; Jordan, Jens

    2002-01-01

    PURPOSE: Water drinking increases blood pressure in a substantial proportion of patients who have severe orthostatic hypotension due to autonomic failure. We tested the hypothesis that water drinking can be used as a practical treatment for patients with orthostatic and postprandial hypotension, as well as those with orthostatic tachycardia. SUBJECTS AND METHODS: We studied the effect of drinking water on seated and standing blood pressure and heart rate in 11 patients who had severe orthostatic hypotension due to autonomic failure and in 9 patients who had orthostatic tachycardia due to idiopathic orthostatic intolerance. We also tested the effect of water drinking on postprandial hypotension in 7 patients who had autonomic failure. Patients drank 480 mL of tap water at room temperature in less than 5 minutes. RESULTS: In patients with autonomic failure, mean (+/- SD) blood pressure after 1 minute of standing was 83 +/- 6/53 +/- 3.4 mm Hg at baseline, which increased to 114 +/- 30/66 +/- 18 mm Hg (P water drinking, compared with 22 +/- 10/12 +/- 5 mm Hg with drinking (P water drinking attenuated orthostatic tachycardia (123 +/- 23 beats per minute) at baseline to 108 +/- 21 beats per minute after water drinking ( P Water drinking elicits a rapid pressor response in patients with autonomic failure and can be used to treat orthostatic and postprandial hypotension. Water drinking moderately reduces orthostatic tachycardia in patients with idiopathic orthostatic intolerance. Thus, water drinking may serve as an adjunctive treatment in patients with impaired orthostatic tolerance.

  10. Characterization of bacterial community dynamics in a full-scale drinking water treatment plant.

    Science.gov (United States)

    Li, Cuiping; Ling, Fangqiong; Zhang, Minglu; Liu, Wen-Tso; Li, Yuxian; Liu, Wenjun

    2017-01-01

    Understanding the spatial and temporal dynamics of microbial communities in drinking water systems is vital to securing the microbial safety of drinking water. The objective of this study was to comprehensively characterize the dynamics of microbial biomass and bacterial communities at each step of a full-scale drinking water treatment plant in Beijing, China. Both bulk water and biofilm samples on granular activated carbon (GAC) were collected over 9months. The proportion of cultivable cells decreased during the treatment processes, and this proportion was higher in warm season than cool season, suggesting that treatment processes and water temperature probably had considerable impact on the R2A cultivability of total bacteria. 16s rRNA gene based 454 pyrosequencing analysis of the bacterial community revealed that Proteobacteria predominated in all samples. The GAC biofilm harbored a distinct population with a much higher relative abundance of Acidobacteria than water samples. Principle coordinate analysis and one-way analysis of similarity indicated that the dynamics of the microbial communities in bulk water and biofilm samples were better explained by the treatment processes rather than by sampling time, and distinctive changes of the microbial communities in water occurred after GAC filtration. Furthermore, 20 distinct OTUs contributing most to the dissimilarity among samples of different sampling locations and 6 persistent OTUs present in the entire treatment process flow were identified. Overall, our findings demonstrate the significant effects that treatment processes have on the microbial biomass and community fluctuation and provide implications for further targeted investigation on particular bacteria populations. Copyright © 2016. Published by Elsevier B.V.

  11. Manganese deposition in drinking water distribution systems

    Energy Technology Data Exchange (ETDEWEB)

    Gerke, Tammie L., E-mail: Tammie.Gerke@miamioh.edu [Department of Geology, University of Cincinnati, Cincinnati, OH 45221-0013 (United States); Little, Brenda J., E-mail: brenda.little@nrlssc.navy.mil [Naval Research Laboratory, Stennis Space Center, MS 39529 (United States); Barry Maynard, J., E-mail: maynarjb@ucmail.uc.edu [Department of Geology, University of Cincinnati, Cincinnati, OH 45221-0013 (United States)

    2016-01-15

    This study provides a physicochemical assessment of manganese deposits on brass and lead components from two fully operational drinking water distributions systems. One of the systems was maintained with chlorine; the other, with secondary chloramine disinfection. Synchrotron-based in-situ micro X-ray adsorption near edge structure was used to assess the mineralogy. In-situ micro X-ray fluorescence mapping was used to demonstrate the spatial relationships between manganese and potentially toxic adsorbed metal ions. The Mn deposits ranged in thickness from 0.01 to 400 μm. They were composed primarily of Mn oxides/oxhydroxides, birnessite (Mn{sup 3+} and Mn{sup 4+}) and hollandite (Mn{sup 2+} and Mn{sup 4+}), and a Mn silicate, braunite (Mn{sup 2+} and Mn{sup 4+}), in varying proportions. Iron, chromium, and strontium, in addition to the alloying elements lead and copper, were co-located within manganese deposits. With the exception of iron, all are related to specific health issues and are of concern to the U.S. Environmental Protection Agency (U.S. EPA). The specific properties of Mn deposits, i.e., adsorption of metals ions, oxidation of metal ions and resuspension are discussed with respect to their influence on drinking water quality. - Highlights: • Oxidation and deposition of Mn deposits in drinking water distribution pipes • In-situ synchrotron-based μ-XANES and μ-XRF mapping • Toxic metal sorption in Mn deposits.

  12. Protecting health from metal exposures in drinking water.

    Science.gov (United States)

    Armour, Margaret-Ann

    2016-03-01

    Drinking water is essential to us as human beings. According to the World Health Organization "The quality of drinking-water is a powerful environmental determinant of health" (http://www.who.int/water_sanitation_health/dwq/en/), but clean drinking water is a precious commodity not always readily available. Surface and ground water are the major sources of drinking water. Both can be contaminated, surface water with bacteria while ground water frequently contains salts of metals that occur naturally or are introduced by human activity. This paper will briefly review the metallic salts found in drinking water in areas around the world, as well as list some of the methods used to reduce or remove them. It will then discuss our research on reducing the risk of pollution of drinking water by removal of metal ions from wastewater.

  13. Water, Water Everywhere, But is it Safe to Drink?

    Science.gov (United States)

    Drinking water disinfection by-products (DBPs) have been associated with adverse human health effects, including bladder cancer, early term miscarriage, and birth defects. While it is vitally important to kill harmful pathogens in water, it is also important to minimize harmful ...

  14. Why Drinking Water Is the Way to Go

    Science.gov (United States)

    ... game, or just working out or playing hard, drink water before, during, and after playing. Don't forget ... is very dark yellow, it's holding on to water, so it's probably time to drink up. You can help your body by drinking ...

  15. [Mechanism of NH(4+)-N removal in drinking water biofilter].

    Science.gov (United States)

    Liu, Bing; Fan, Hui; Yu, Guo-Zhong; Yu, Xin; Zhao, Cheng-Mei; Li, Qing-Fei; Zhang, Shu-Ting; Wei, Bo

    2012-07-01

    In order to explore the mechanism of NH(4+)-N removal in drinking water biofilter, water quality parameters, such as NH(4+)-N, NO(2-)-N, NO(3-)-N, total phosphorus, permanganate index, nitrogen gas, temperature and dissolved oxygen etc, were determined in the inflow and outflow of biofilter. Samples of granular activated carbon (GAC) at different height (0, 10, 20, 40, 60 cm) of the biofiter media were collected and analyzed for the bacterial community with molecular biology techniques. The bacterial diversity in the activated carbon biofilm sample was studied based on the phylogenetic analysis of sequences. The results showed that there were three stages according to the NH(4+)-N concentration in the influent. The "nitrogen loss" phenomenon (total inorganic nitrogen in the effluent was less than that in the influent) occurred at the first, second and third stages and the amount of nitrogen loss were 0.94, 0.32 and 0.15 mg x L(-1), respectively. The amount of nitrogen loss had a good positive correlation with the NH(4+)-N concentration in the influent, but not a linear relationship with the concentration of the permanganate index in the influent. The average concentrations of N2 increased gradually with the height of media in the biofilter, with values of 14.04 and 14.67 mg x L(-1) in the influent and the effluent, respectively. Based on the sequencing results, the ammonia-oxidizing bacteria (AOB) in the activated carbon biofilm were classified into three common genera: Nitrosococcus, Nitrosomonas and Nitrosospira. When the NH(4+)-N concentration in the influent was relatively high, the "nitrogen loss" phenomenon in biofilter was caused by the AOB.

  16. Desalinated drinking water in the GCC countries - The need to address consumer perceptions.

    Science.gov (United States)

    Shomar, Basem; Hawari, Jalal

    2017-10-01

    The Gulf Cooperation Council (GCC) countries consist of Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates. These countries depend mainly on seawater desalination to meet their water needs. Although great emphasis is given to characterize desalinated water for its physicochemical and microbial properties, e.g. presence of metals, other organic contaminants and for bacteria, sensorial characteristics including smell, taste and color have not received the same attention. This is possibly attributed to the fact that inhabitants of GCC States do not use desalinated tap water for drinking consumption, rather they depend on locally produced or imported bottled water where color, taste and odor are not problematic. To address the consumer needs and perceptions of drinking desalinated water in GCC countries, water quality standards and guidelines, should respond to the public concern about other sensorial characteristics (organoleptic properties) including taste, odor, and trigeminal sensations. Often the root causes of color and smell in water are attributed to the presence of organic and inorganic contaminants and to bacterial growth which is frequently accompanied by the production of metabolites and byproducts that are obnoxious. The unpleasant sensorial problems associated with desalinated drinking tap water may constitute the driving force for most people in GCC countries to depend on bottled water. To encourage people in the GCC countries to consume desalinated tap water, it is essential that water testing include measurements of physicochemical properties, biofilm presence and organoleptic parameters to improve overall water quality. This review highlights the contribution of organoleptics for consumers of desalinated tap water. It extends water quality research to be addressed by standards for organoleptic parameters in desalinated drinking water. Accordingly, consumer awareness and outreach campaigns should be implemented to encourage people

  17. [Revision of the drinking water regulations].

    Science.gov (United States)

    Hauswirth, S

    2011-11-01

    The revision the Drinking Water Regulations will come into effect on 01.11.2011. Surveillance authorities and owners of drinking water supply systems had hoped for simplifications and reductions because of the new arrangements. According to the official statement for the revision the legislature intended to create more clarity, consider new scientific findings, to change regulations that have not been proved to close regulatory gaps, to deregulate and to increase the high quality standards. A detailed examination of the regulation text, however, raises doubts. The new classification of water supply systems requires different modalities of registration, water analyses and official observation, which will complicate the work of the authorities. In particular, the implementation of requirements of registration and examination for the owners of commercial and publicly-operated large hot-water systems in accordance with DVGW Worksheet W 551 requires more effort. According to the estimated 30 000 cases of legionellosis in Germany the need for a check of such systems for Legionella, however, is not called into question. Furthermore, the development of sampling plans and the monitoring of mobile water supply systems requires more work for the health authorities.

  18. Sonication for advanced drinking water treatment

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guang-ming; WEI Xi-zhu; LI Xiang-kun; ZHANG Jie; DOU Zi-bo

    2009-01-01

    This paper investigated the feasibility of sonication as an advanced treatment method for drinking water production and used comprehensive indexes of water quality to examine its efficiency. Results show that sonication significantly reduces the toxicity of water. Sonication with 5 W/L at 90 kHz lasting for 30 min decreases he water SUVA and the disinfection byproduct formation potential (DBPFP) by 38.7% and 27.2% respective ly. Sonieation also decreases the UV254 by more than 50% through destroying unsaturated chemical bonds.Higher sound intensity and higher frequency benefit the reduction of TOC and UV254, Besides, sonication significantly increases the affinity of organics with granular activated carbon (GAC), and thus the hybrid sonication-GAC method reduces the water TOC, COD, UV254, and DBPFP by 78. 3%, 69.4%, 75.7%, and 70. 0% respectively. Therefore, sonieation and the hybrid sonieation-GAC method are proposed as advanced treatment methods for drinking water.

  19. Estimation of nitrite, nitrate, and N-nitrosamines in drinking water and soft drinks

    Energy Technology Data Exchange (ETDEWEB)

    Alwan, S.M.; Jawad, I.M.; Abdul-Rahman, S.K.; Al-Kafaji, S.H.

    1987-09-01

    A survey for the determination of the carcinogenic N-nitrosamines in drinking water and selected soft drinks was achieved, using a GLC method. This shows that these substances occur predominantly in the drinks. The average contents of dimethylnitrosamine and diethylnitrosamine in drinking water were 4.1 ..mu..g/L and 0.2 ..mu..g/L respectively, while they were approximately 3.9 ..mu..g/L and 0.43 ..mu..g/L in soft drinks. Nitrite and nitrate contents in drinking water samples were also estimated, as potential factors for the formation of N-nitrosamines. The mean contents of nitrite and nitrate in drinking water were 65 g/L and 10.8 g/L respectively.

  20. 75 FR 54871 - National Drinking Water Advisory Council's Climate Ready Water Utilities Working Group Meeting...

    Science.gov (United States)

    2010-09-09

    ... AGENCY National Drinking Water Advisory Council's Climate Ready Water Utilities Working Group Meeting... Water Utilities (CRWU) Working Group of the National Drinking Water Advisory Council (NDWAC). The.... Environmental Protection Agency, Office of Ground Water and Drinking Water, Water Security Division (Mail...

  1. Presence of potential bacterial pathogens in a municipal drinking water supply system.

    Science.gov (United States)

    Felföldi, T; Tarnóczai, Tímea; Homonnay, Z G

    2010-09-01

    The quality of drinking water is a major public concern, but the detection of most potential pathogens is not always included in drinking water hygienic monitoring or is only assessed with highly biased cultivation-based methods. In this study, the occurrence of Pseudomonas aeruginosa and Legionella spp. was examined with taxon-specific PCRs in samples taken at ten points of a municipal drinking water supply system in three months. Sequence analysis confirmed the positivity of samples and revealed a diverse community of legionellae. The results showed that chlorination was an important and effective disinfection method against pathogenic bacteria in drinking water, but pathogenic bacteria could reoccur in the system farther away from the chlorination point. No strong correlation was found between the presence of the investigated potentially pathogenic bacteria and the measured abiotic and biotic parameters within the investigated range. It is hypothesized that instead of physicochemical parameters, the main factors influencing the presence of pathogens in the drinking water were rather the composition of the microbial community, the biotic interactions between individual non-pathogenic and pathogenic microorganisms (competition or promotion of growth) and the structure of biofilm grown on the inner surface of the supply system.

  2. Drinking Water Quality Status and Contamination in Pakistan

    Science.gov (United States)

    Nafees, Muhammad; Rizwan, Muhammad; Bajwa, Raees Ahmad; Shakoor, Muhammad Bilal; Arshad, Muhammad Umair; Chatha, Shahzad Ali Shahid; Deeba, Farah; Murad, Waheed; Malook, Ijaz

    2017-01-01

    Due to alarming increase in population and rapid industrialization, drinking water quality is being deteriorated day by day in Pakistan. This review sums up the outcomes of various research studies conducted for drinking water quality status of different areas of Pakistan by taking into account the physicochemical properties of drinking water as well as the presence of various pathogenic microorganisms. About 20% of the whole population of Pakistan has access to safe drinking water. The remaining 80% of population is forced to use unsafe drinking water due to the scarcity of safe and healthy drinking water sources. The primary source of contamination is sewerage (fecal) which is extensively discharged into drinking water system supplies. Secondary source of pollution is the disposal of toxic chemicals from industrial effluents, pesticides, and fertilizers from agriculture sources into the water bodies. Anthropogenic activities cause waterborne diseases that constitute about 80% of all diseases and are responsible for 33% of deaths. This review highlights the drinking water quality, contamination sources, sanitation situation, and effects of unsafe drinking water on humans. There is immediate need to take protective measures and treatment technologies to overcome unhygienic condition of drinking water supplies in different areas of Pakistan. PMID:28884130

  3. A new method to assess the influence of migration from polymeric materials on the biostability of drinking water.

    Science.gov (United States)

    Bucheli-Witschel, Margarete; Kötzsch, Stefan; Darr, Stephan; Widler, Roland; Egli, Thomas

    2012-09-01

    After having produced drinking water of high quality it is of vital interest to distribute the water without compromising its quality neither by recontamination nor by microbial regrowth. To minimize regrowth, the strategy of distributing biostable water is followed in several European countries. This implies on one hand the production of water that has a low level of growth-supporting nutrients, in particular organic carbon compounds, and, on the other hand, using materials for storage/distribution that have a low biofilm formation potential and from which only low amounts of total organic carbon (TOC) leach into the water phase. Currently, the approval of materials in contact with drinking water relies on two tests, a migration test and a biofilm formation test. Here we describe an extended migration testing procedure that allows to obtain information not only on the amount of chemical compounds but also on the amount of growth-supporting compounds leaching into the water. In short, the test developed combines several migration cycles and subsequent measurement of the TOC with a novel, fast and reliable test method for determining the assimilable organic carbon (AOC) in the migration waters. AOC gives an indication on the growth-supporting properties of the material. Thus, an initial characterisation of a material with respect to its suitability for usage in contact with drinking water can be performed in a single assay. Results obtained with the new assay for a number of materials typically used in drinking water and sanitary installations are reported.

  4. Defluoridation of drinking water by using Calcium loaded Bentonite

    African Journals Online (AJOL)

    Dr.M.Singanan

    Hence, this process can be recommended for the water treatment. The untreated ... KEY WORDS: Drinking water, fluoride removal, bentonite C and red clay. INTRODUCTION. Water is ... find alternative water sources and suitable cost effective ...

  5. The function of advanced treatment process in a drinking water treatment plant with organic matter-polluted source water.

    Science.gov (United States)

    Lin, Huirong; Zhang, Shuting; Zhang, Shenghua; Lin, Wenfang; Yu, Xin

    2017-04-01

    To understand the relationship between chemical and microbial treatment at each treatment step, as well as the relationship between microbial community structure in biofilms in biofilters and their ecological functions, a drinking water plant with severe organic matter-polluted source water was investigated. The bacterial community dynamics of two drinking water supply systems (traditional and advanced treatment processes) in this plant were studied from the source to the product water. Analysis by 454 pyrosequencing was conducted to characterize the bacterial diversity in each step of the treatment processes. The bacterial communities in these two treatment processes were highly diverse. Proteobacteria, which mainly consisted of beta-proteobacteria, was the dominant phylum. The two treatment processes used in the plant could effectively remove organic pollutants and microbial polution, especially the advanced treatment process. Significant differences in the detection of the major groups were observed in the product water samples in the treatment processes. The treatment processes, particularly the biological pretreatment and O3-biological activated carbon in the advanced treatment process, highly influenced the microbial community composition and the water quality. Some opportunistic pathogens were found in the water. Nitrogen-relative microorganisms found in the biofilm of filters may perform an important function on the microbial community composition and water quality improvement.

  6. Ammonia pollution characteristics of centralized drinking water sources in China

    Institute of Scientific and Technical Information of China (English)

    Qing Fu; Binghui Zheng; Xingru Zhao; Lijing Wang; Changming Liu

    2012-01-01

    The characteristics of ammonia in drinking water sources in China were evaluated during 2005-2009.The spatial distribution and seasonal changes of ammonia in different types of drinking water sources of 22 provinces,5 autonomous regions and 4 municipalities were investigated.The levels of ammonia in drinking water sources follow the order of river > lake/reservoir > groundwater.The levels of ammonia concentration in river sources gradually decreased from 2005 t0 2008,while no obvious change was observed in the lakes/reservoirs and groundwater drinking water sources.The proportion of the type of drinking water sources is different in different regions.In river drinking water sources,the ammonia level was varied in different regions and changed seasonally.The highest value and wide range of annual ammonia was found in South East region,while the lowest value was found in Southwest region.In lake/reservoir drinking water sources,the ammonia levels were not varied obviously in different regions.In underground drinking water sources,the ammonia levels were varied obviously in different regions due to the geological permeability and the natural features of regions.In the drinking water sources with higher ammonia levels,there are enterprises and wastewater drainages in the protected areas of the drinking water sources.

  7. Ammonia pollution characteristics of centralized drinking water sources in China.

    Science.gov (United States)

    Fu, Qing; Zheng, Binghui; Zhao, Xingru; Wang, Lijing; Liu, Changming

    2012-01-01

    The characteristics of ammonia in drinking water sources in China were evaluated during 2005-2009. The spatial distribution and seasonal changes of ammonia in different types of drinking water sources of 22 provinces, 5 autonomous regions and 4 municipalities were investigated. The levels of ammonia in drinking water sources follow the order of river > lake/reservoir > groundwater. The levels of ammonia concentration in river sources gradually decreased from 2005 to 2008, while no obvious change was observed in the lakes/reservoirs and groundwater drinking water sources. The proportion of the type of drinking water sources is different in different regions. In river drinking water sources, the ammonia level was varied in different regions and changed seasonally. The highest value and wide range of annual ammonia was found in South East region, while the lowest value was found in Southwest region. In lake/reservoir drinking water sources, the ammonia levels were not varied obviously in different regions. In underground drinking water sources, the ammonia levels were varied obviously in different regions due to the geological permeability and the natural features of regions. In the drinking water sources with higher ammonia levels, there are enterprises and wastewater drainages in the protected areas of the drinking water sources.

  8. Benefits of Safer Drinking Water: The Value of Nitrate Reduction

    OpenAIRE

    Crutchfield, Stephen R.; Cooper, Joseph C.; Hellerstein, Daniel

    1997-01-01

    Nitrates in drinking water, which may come from nitrogen fertilizers applied to crops, are a potential health risk. This report evaluates the potential benefits of reducing human exposure to nitrates in the drinking water supply. In a survey, respondents were asked a series of questions about their willingness to pay for a hypothetical water filter, which would reduce their risk of nitrate exposure. If nitrates in the respondent's drinking water were to exceed the EPA minimum safety standard,...

  9. Biological stability of drinking water: Controlling factors, methods, and challenges

    NARCIS (Netherlands)

    Prest, E.I.E.D.; Hammes, F.; Van Loosdrecht, M.C.M.; Vrouwenvelder, J.S.

    2016-01-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and ca

  10. Biological stability of drinking water: Controlling factors, methods, and challenges

    NARCIS (Netherlands)

    Prest, E.I.E.D.; Hammes, F.; Van Loosdrecht, M.C.M.; Vrouwenvelder, J.S.

    2016-01-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and ca

  11. 30 CFR 71.600 - Drinking water; general.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drinking water; general. 71.600 Section 71.600 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH... Water § 71.600 Drinking water; general. An adequate supply of potable water shall be provided...

  12. Biological stability of drinking water: Controlling factors, methods, and challenges

    NARCIS (Netherlands)

    Prest, E.I.E.D.; Hammes, F.; Van Loosdrecht, M.C.M.; Vrouwenvelder, J.S.

    2016-01-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and

  13. Atomic Force Microscopy (AFM) for In-Situ Biofilm Surface Characterization during Free Chlorine and Monochloramine Exposure

    Science.gov (United States)

    Drinking water distribution system biofilm are attached to pipe walls and found in sediments. These biofilms are complex and contain a variety of microorganisms embedded in a matrix with extracellular polymeric substances (EPS), providing protection from disinfection. Without pro...

  14. Atomic Force Microscopy (AFM) for In-Situ Biofilm Surface Characterization during Free Chlorine and Monochloramine Exposure

    Science.gov (United States)

    Drinking water distribution system biofilm are attached to pipe walls and found in sediments. These biofilms are complex and contain a variety of microorganisms embedded in a matrix with extracellular polymeric substances (EPS), providing protection from disinfection. Without pro...

  15. Comparing Methods of Separating Bacterial Biofilms on the Surface of Water Transportation Pipes and Equipment of Milking in the Farms

    Directory of Open Access Journals (Sweden)

    setareh nabizadeh

    2016-08-01

    Full Text Available Introduction Bacterial biofilms can be both useful and harmful based on their combination and locations. Biofilm formation occurs as a stepwise process. Their formation in liquid transportation pipes used for milking system and drinking water in animal farms may create some problems and is a potential source of pollution. Speed of biofilm formation depends on many factors including: construction and functional characteristics of bacteria, the composition and culture conditions such as temperature and substratum. In this research the Bacillus subtillis bacteria with special characteristics was selected due to its capability for biofilm creation. Bacillus subtillis bacteria is mobility and a stronger connection than other bacteria levels are created. In the research conducted in the biofilm there are many resources on biofilm formation by Bacillus subtillis bacteria. Bacillus subtillis is saprophytic in the soil, water and air. There is also the ability to form spores of Bacillus subtillis. Materials and Methods Firstly the possibility of creating biofilms on different Plastic (polyvinilchlorid, polypropylene, polyethylengelycole, alluminum and glass surfaces in three temperatures of 4°C, 30°C and 37°C were studied. Two different methods of biofilms separation including separating swap and vortex were tested and their efficienceies were calculated. After biofilm formation on parts of the vortex separation method after washing parts in sterile conditions in a tube containing normal saline for 4 minutes was vortex. The bacterial suspension decreasing dilution series was created. Pour plate in medium using agar plate count agar and was cultured at 30°C for 24-48 hours. Numbers of colonies were counted. The numbers of biofilm cells were calculated. In swap method after biofilm formation on parts using a cotton swap was isolated biofilms. The swap was transferred to tube containing normal saline and the bacterial suspension decreasing dilution

  16. Portable Nanomesh Creates Safer Drinking Water

    Science.gov (United States)

    2008-01-01

    Providing astronauts with clean water is essential to space exploration to ensure the health and well-being of crewmembers away from Earth. For the sake of efficient and safe long-term space travel, NASA constantly seeks to improve the process of filtering and re-using wastewater in closed-loop systems. Because it would be impractical for astronauts to bring months (or years) worth of water with them, reducing the weight and space taken by water storage through recycling and filtering as much water as possible is crucial. Closed-loop systems using nanotechnology allow wastewater to be cleaned and reused while keeping to a minimum the amount of drinking water carried on missions. Current high-speed filtration methods usually require electricity, and methods without electricity usually prove impractical or slow. Known for their superior strength and electrical conductivity, carbon nanotubes measure only a few nanometers in diameter; a nanometer is one billionth of a meter, or roughly one hundred-thousandth the width of a human hair. Nanotubes have improved water filtration by eliminating the need for chemical treatments, significant pressure, and heavy water tanks, which makes the new technology especially appealing for applications where small, efficient, lightweight materials are required, whether on Earth or in space. "NASA will need small volume, effective water purification systems for future long-duration space flight," said Johnson Space Center s Karen Pickering. NASA advances in water filtration with nanotechnology are now also protecting human health in the most remote areas of Earth.

  17. Lithium in drinking water and thyroid function.

    Science.gov (United States)

    Broberg, Karin; Concha, Gabriela; Engström, Karin; Lindvall, Magnus; Grandér, Margareta; Vahter, Marie

    2011-06-01

    High concentrations of lithium in drinking water were previously discovered in the Argentinean Andes Mountains. Lithium is used worldwide for treatment of bipolar disorder and treatment-resistant depression. One known side effect is altered thyroid function. We assessed associations between exposure to lithium from drinking water and other environmental sources and thyroid function. Women (n=202) were recruited in four Andean villages in northern Argentina. Lithium exposure was assessed based on concentrations in spot urine samples, measured by inductively coupled plasma mass spectrometry. Thyroid function was evaluated by plasma free thyroxine (T4) and pituitary gland thyroid-stimulating hormone (TSH), analyzed by routine immunometric methods. The median urinary lithium concentration was 3,910 μg/L (5th, 95th percentiles, 270 μg/L, 10,400 μg/L). Median plasma concentrations (5th, 95th percentiles) of T4 and TSH were 17 pmol/L (13 pmol/L, 21 pmol/L) and 1.9 mIU/L, (0.68 mIU/L, 4.9 mIU/L), respectively. Urine lithium was inversely associated with T4 [β for a 1,000-μg/L increase=-0.19; 95% confidence interval (CI), -0.31 to -0.068; p=0.002] and positively associated with TSH (β=0.096; 95% CI, 0.033 to 0.16; p=0.003). Both associations persisted after adjustment (for T4, β=-0.17; 95% CI, -0.32 to -0.015; p=0.032; for TSH: β=0.089; 95% CI, 0.024 to 0.15; p=0.007). Urine selenium was positively associated with T4 (adjusted T4 for a 1 μg/L increase: β=0.041; 95% CI, 0.012 to 0.071; p=0.006). Exposure to lithium via drinking water and other environmental sources may affect thyroid function, consistent with known side effects of medical treatment with lithium. This stresses the need to screen for lithium in all drinking water sources.

  18. Coliform Sources and Mechanisms for Regrowth in Household Drinking Water in Limpopo, South Africa.

    Science.gov (United States)

    Mellor, Jonathan E; Smith, James A; Samie, Amidou; Dillingham, Rebecca A

    2013-09-01

    Resource-limited communities throughout the developing world face significant environmental health problems related to the myriad of coliform sources within those communities. This study comprehensively investigated contamination sources and the biological and chemical mechanisms sustaining them in two adjacent communities in rural Limpopo, South Africa. An 8-month study was conducted of household (n = 14) and source water quality, measurements of biofilm layers on the inside of household water storage containers and water transfer devices, and also hand-based coliforms and hand-washing effectiveness. A 7-day water container incubation experiment was also performed to determine the biological and chemical changes that occur in a household water storage container independent of human interference. Results indicate that household drinking water frequently becomes contaminated after collection but before consumption (197 versus 1,046 colony-forming units/100 mL; n = 266; p water treatment and other interventions aimed at maintaining the safe water chain and preventing biological regrowth.

  19. Association and decontamination of Bacillus spores in a simulated drinking water system.

    Science.gov (United States)

    Morrow, J B; Almeida, J L; Fitzgerald, L A; Cole, K D

    2008-12-01

    The objective of this work was to elucidate the disinfectant susceptibility of Bacillus anthracis Sterne (BA) and a commercial preparation of Bacillus thuringiensis (BT) spores associated with a simulated drinking water system. Biofilms composed of indigenous water system bacteria were accumulated on copper and polyvinyl chloride (PVC) pipe material surfaces in a low-flow pipe loop and uniformly mixed tank reactor (CDC biofilm reactor). Application of a distributed shear during spore contact resulted in approximately a 1.0 and 1.6 log10 increase in the number of spores associated with copper and PVC surfaces, respectively. Decontamination of spores in both free suspension and after association with biofilm-conditioned pipe materials was attempted using free chlorine and monochloramine. Associated spores required 5- to 10-fold higher disinfectant concentrations to observe the same reduction of viable spores as in suspension. High disinfectant concentrations (103 mg/L free chlorine and 49 mg/L monochloramine) yielded less than a 2-log10 reduction in viable associated spores after 60 min. Spores associated with biofilms on copper surfaces consistently yielded higher Ct values than PVC.

  20. Chlorinated drinking water for lightweight laying hens

    Directory of Open Access Journals (Sweden)

    A.F. Schneider

    Full Text Available ABSTRACT The study aimed to evaluate the effect of different levels of chlorine in drinking water of laying hens on zootechnical performance, eggs shell quality, hemogasometry levels and calcium content in tibia. 144 Hy-Line laying hens, 61 weeks old, were used distributed in 24 metabolism cages. They were subjected to water diets, for a period of 28 days, using sodium hypochlorite as a chlorine source in order to obtain the following concentrations: 5ppm (control, 20ppm, 50ppm, and 100ppm. Their performance was evaluated through water consumption, feed intake, egg production and weight, egg mass, feed conversion. Shell quality was measured by specific gravity. At the end of the experiment, arterial blood was collected for blood gas level assessment and a poultry of each replicate was sacrificed to obtain tibia and calcium content measurement. There was a water consumption reduction from 20ppm of chlorine and feed intake reduction in poultry receiving water with 100ppm of chlorine. The regression analysis showed that the higher the level of chlorine in water, the higher the reduction in consumption. There were no differences in egg production and weight, egg mass, feed conversion, specific gravity, tibia calcium content, and hemogasometry levels (hydrogenionic potential, carbon dioxide partial pressure, oxygen partial pressure, sodium, potassium, chloride, bicarbonate, carbon dioxide total concentration, anion gap and oxygen saturation. The use of levels above 5ppm of chlorine is not recommended in the water of lightweight laying hens.

  1. Iron and manganese removal from drinking water

    Directory of Open Access Journals (Sweden)

    Daniela-Elena Pascu

    2016-04-01

    Full Text Available The purpose of the present study is to find a suitable method for removal of iron and manganese from ground water, considering bothlocal economical and environmental aspects. Ground water is a highly important source of drinking water in Romania. Ground water is naturally pure from bacteria at a 25 m depth or more. However, solved metals may occur and if the levels are too high, the water is not drinkable. Different processes, such as electrochemical and combined electrochemical-adsorption methods have been applied to determine metals content in accordance to reports of National Water Agency from Romania (ANAR. Every water source contains dissolved or particulate compounds. The concentrations of these compounds can affect health, productivity, compliance requirements, or serviceability and cannot be economically removed by conventional filtration means. In this study, we made a comparison between the electrochemical and adsorption methods (using membranes. Both methods have been used to evaluate the efficiency of iron and manganese removal at various times and temperatures. We used two membrane types: composite and cellulose, respectively. Different approaches, including lowering the initial current density and increasing the initial pH were applied. Reaction kinetics was achieved using mathematical models: Jura and Temkin.

  2. Melioidosis caused by Burkholderia pseudomallei in drinking water, Thailand, 2012.

    Science.gov (United States)

    Limmathurotsakul, Direk; Wongsuvan, Gumphol; Aanensen, David; Ngamwilai, Sujittra; Saiprom, Natnaree; Rongkard, Patpong; Thaipadungpanit, Janjira; Kanoksil, Manas; Chantratita, Narisara; Day, Nicholas P J; Peacock, Sharon J

    2014-02-01

    We identified 10 patients in Thailand with culture-confirmed melioidosis who had Burkholderia pseudomallei isolated from their drinking water. The multilocus sequence type of B. pseudomallei from clinical specimens and water samples were identical for 2 patients. This finding suggests that drinking water is a preventable source of B. pseudomallei infection.

  3. Start-up of a drinking water biofilter

    DEFF Research Database (Denmark)

    Ramsay, Loren; Søborg, Ditte; Breda, Inês Lousinha Ribeiro

    When virgin filter media is placed in drinking water biofilters, a start-up period of some months typically ensues. During this period, the necessary inorganic coating and bacterial community are established on the filter medium, after which the treated water complies with drinking water criteria...

  4. 30 CFR 75.1718-1 - Drinking water; quality.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drinking water; quality. 75.1718-1 Section 75... AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1718-1 Drinking water; quality. (a) Potable water provided in accordance with the provisions of § 75.1718 shall meet the...

  5. Continous assessment of a drinking water PVC pipe

    NARCIS (Netherlands)

    Marques Arsenio, A.; Vreeburg, J.H.G.; Wielinga, M.P.C.; Van Dijk, J.C.

    2012-01-01

    In 2010 the Dutch drinking water network stretched for almost 116,000 km supplying water to more than 16 million people. Almost 50% was made of PVC. The analysis of the failure registration of 5 Dutch drinking water companies showed that ca. 29 % of the total number of failures in the PVC Dutch netw

  6. Manganese deposition in drinking water distribution systems.

    Science.gov (United States)

    Gerke, Tammie L; Little, Brenda J; Barry Maynard, J

    2016-01-15

    This study provides a physicochemical assessment of manganese deposits on brass and lead components from two fully operational drinking water distributions systems. One of the systems was maintained with chlorine; the other, with secondary chloramine disinfection. Synchrotron-based in-situ micro X-ray adsorption near edge structure was used to assess the mineralogy. In-situ micro X-ray fluorescence mapping was used to demonstrate the spatial relationships between manganese and potentially toxic adsorbed metal ions. The Mn deposits ranged in thickness from 0.01 to 400 μm. They were composed primarily of Mn oxides/oxhydroxides, birnessite (Mn(3+) and Mn(4+)) and hollandite (Mn(2+) and Mn(4+)), and a Mn silicate, braunite (Mn(2+) and Mn(4+)), in varying proportions. Iron, chromium, and strontium, in addition to the alloying elements lead and copper, were co-located within manganese deposits. With the exception of iron, all are related to specific health issues and are of concern to the U.S. Environmental Protection Agency (U.S. EPA). The specific properties of Mn deposits, i.e., adsorption of metals ions, oxidation of metal ions and resuspension are discussed with respect to their influence on drinking water quality.

  7. [Hydraulic fracturing - a hazard for drinking water?].

    Science.gov (United States)

    Ewers, U; Gordalla, B; Frimmel, F

    2013-11-01

    Hydraulic fracturing (fracking) is a technique used to release and promote the extraction of natural gas (including shale gas, tight gas, and coal bed methane) from deep natural gas deposits. Among the German public there is great concern with regard to the potential environmental impacts of fracking including the contamination of ground water, the most important source of drinking water in Germany. In the present article the risks of ground water contamination through fracking are discussed. Due to the present safety requirements and the obligatory geological and hydrogeological scrutiny of the underground, which has to be performed prior to fracking, the risk of ground water contamination by fracking can be regarded as very low. The toxicity of chemical additives of fracking fluids is discussed. It is recommended that in the future environmental impact assessment and approval of fracs should be performed by the mining authorities in close cooperation with the water authorities. Furthermore, it is recommended that hydraulic fracturing in the future should be accompanied by obligatory ground water monitoring.

  8. Optimisation of ATP determination in drinking water

    DEFF Research Database (Denmark)

    Corfitzen, Charlotte B.; Albrechtsen, Hans-Jørgen

    Adenosine Triphosphate (ATP) can be used as a relative measure of cell activity, and is measured by the light output from the reaction between luciferin and ATP catalyzed by firefly luciferase. The measurement has potential as a monitoring and surveillance tool within drinking water distribution......, since the method is very sensitive (detects 0.5 ng ATP/L) and results are obtained within minutes. When calculating the ATP value a number of parameters need to be considered. These were investigate by use of two different reagent kits (PCP-kit and Lumin(ATE)/Lumin(EX)-kit), internal standard...... and an Advance Coupe luminometer. The investigations showed a 60 times higher response of the PCP-kit, making it more suitable for measurement of samples with low ATP content. ATP-standard dilutions prepared in tap water were stable for at least 15 months when stored frozen at -80ºC, and storage of large...

  9. Optimisation of ATP determination in drinking water

    DEFF Research Database (Denmark)

    Corfitzen, Charlotte B.; Albrechtsen, Hans-Jørgen

    Adenosine Triphosphate (ATP) can be used as a relative measure of cell activity, and is measured by the light output from the reaction between luciferin and ATP catalyzed by firefly luciferase. The measurement has potential as a monitoring and surveillance tool within drinking water distribution......, since the method is very sensitive (detects 0.5 ng ATP/L) and results are obtained within minutes. When calculating the ATP value a number of parameters need to be considered. These were investigate by use of two different reagent kits (PCP-kit and Lumin(ATE)/Lumin(EX)-kit), internal standard...... and an Advance Coupe luminometer. The investigations showed a 60 times higher response of the PCP-kit, making it more suitable for measurement of samples with low ATP content. ATP-standard dilutions prepared in tap water were stable for at least 15 months when stored frozen at -80ºC, and storage of large...

  10. Vulnerability of drinking water supplies to engineered nanoparticles.

    Science.gov (United States)

    Troester, Martin; Brauch, Heinz-Juergen; Hofmann, Thilo

    2016-06-01

    The production and use of engineered nanoparticles (ENPs) inevitably leads to their release into aquatic environments, with the quantities involved expected to increase significantly in the future. Concerns therefore arise over the possibility that ENPs might pose a threat to drinking water supplies. Investigations into the vulnerability of drinking water supplies to ENPs are hampered by the absence of suitable analytical methods that are capable of detecting and quantifiying ENPs in complex aqueous matrices. Analytical data concerning the presence of ENPs in drinking water supplies is therefore scarce. The eventual fate of ENPs in the natural environment and in processes that are important for drinking water production are currently being investigated through laboratory based-experiments and modelling. Although the information obtained from these studies may not, as yet, be sufficient to allow comprehensive assessment of the complete life-cycle of ENPs, it does provide a valuable starting point for predicting the significance of ENPs to drinking water supplies. This review therefore addresses the vulnerability of drinking water supplies to ENPs. The risk of ENPs entering drinking water is discussed and predicted for drinking water produced from groundwater and from surface water. Our evaluation is based on reviewing published data concerning ENP production amounts and release patterns, the occurrence and behavior of ENPs in aquatic systems relevant for drinking water supply and ENP removability in drinking water purification processes. Quantitative predictions are made based on realistic high-input case scenarios. The results of our synthesis of current knowledge suggest that the risk probability of ENPs being present in surface water resources is generally limited, but that particular local conditions may increase the probability of raw water contamination by ENPs. Drinking water extracted from porous media aquifers are not generally considered to be prone to ENP

  11. Improved biostability assessment of drinking water with a suite of test methods at a water supply treating eutrophic lake water.

    Science.gov (United States)

    van der Kooij, Dick; Martijn, Bram; Schaap, Peter G; Hoogenboezem, Wim; Veenendaal, Harm R; van der Wielen, Paul W J J

    2015-12-15

    Assessment of drinking-water biostability is generally based on measuring bacterial growth in short-term batch tests. However, microbial growth in the distribution system is affected by multiple interactions between water, biofilms and sediments. Therefore a diversity of test methods was applied to characterize the biostability of drinking water distributed without disinfectant residual at a surface-water supply. This drinking water complied with the standards for the heterotrophic plate count and coliforms, but aeromonads periodically exceeded the regulatory limit (1000 CFU 100 mL(-1)). Compounds promoting growth of the biopolymer-utilizing Flavobacterium johnsoniae strain A3 accounted for c. 21% of the easily assimilable organic carbon (AOC) concentration (17 ± 2 μg C L(-1)) determined by growth of pure cultures in the water after granular activated-carbon filtration (GACF). Growth of the indigenous bacteria measured as adenosine tri-phosphate in water samples incubated at 25 °C confirmed the low AOC in the GACF but revealed the presence of compounds promoting growth after more than one week of incubation. Furthermore, the concentration of particulate organic carbon in the GACF (83 ± 42 μg C L(-1), including 65% carbohydrates) exceeded the AOC concentration. The increased biomass accumulation rate in the continuous biofouling monitor (CBM) at the distribution system reservoir demonstrated the presence of easily biodegradable by-products related to ClO2 dosage to the GACF and in the CBM at 42 km from the treatment plant an iron-associated biomass accumulation was observed. The various methods applied thus distinguished between easily assimilable compounds, biopolymers, slowly biodegradable compounds and biomass-accumulation potential, providing an improved assessment of the biostability of the water. Regrowth of aeromonads may be related to biomass-turnover processes in the distribution system, but establishment of quantitative relationships is needed for

  12. Biological stability in drinking water distribution systems: A novel approach for systematic microbial water quality monitoring

    NARCIS (Netherlands)

    Prest, E.I.E.D.

    2015-01-01

    Challenges to achieve biological stability in drinking water distribution systems Drinking water is distributed from the treatment facility to consumers through extended man-made piping systems. The World Health Organization drinking water guidelines (2006) stated that “Water entering the distribut

  13. Biological stability in drinking water distribution systems: A novel approach for systematic microbial water quality monitoring

    NARCIS (Netherlands)

    Prest, E.I.E.D.

    2015-01-01

    Challenges to achieve biological stability in drinking water distribution systems Drinking water is distributed from the treatment facility to consumers through extended man-made piping systems. The World Health Organization drinking water guidelines (2006) stated that “Water entering the

  14. [The EU drinking water recommendations: objectives and perspectives].

    Science.gov (United States)

    Blöch, H

    2011-12-01

    Protection of our drinking water resources and provision of safe drinking water are key requirements of modern water management and health policy. Microbiological and chemical quality standards have been established in the EU water policy since 1980, and are now complemented by a comprehensive protection of water as a resource. This contribution reflects a presentation at the scientific conference of the Federal Associations of Physicians and Dentists within the Public Health Service in May 2011 and provides an overview on objectives and challenges for drinking water protection at the European level.

  15. MAGNESIUM, DRINKING WATER HARDNESS AND CARDIOVASCULAR DISEASE

    Directory of Open Access Journals (Sweden)

    Dragana Nikic

    2006-01-01

    Full Text Available Many different countries suggest and justify an integrated laboratory and epidemiological research program with an aim to reject or accept the magnesium – CVD (cardiovascular disease hypothesis. The studies shown in this paper that have investigated the relationship between water hardness, especially magnesium and CVD indicate that, even though there has been an ongoing research for nearly half a century (1957-2004, it has not been completed yet. Different study designs (obductional, clinical, ecological, case-control and cohort restrict an adequate comparison of their results as well as the deduction of results applicable on each territorial level.The majority of researchers around the world, using populational and individual studies, have found an inverse (protective association between mortality and morbidity from CVD and the increase in water hardness, especially the increase in the concentration of magnesium. The most frequent benefit of the water with an optimal mineral composition is the reduction of mortality from ischemic heart disease.It was suggested that Mg from water is a supplementary source of Mg of high biological value, because magnesium from water is absorbed around 30% better than Mg in a diet. The vast majority of studies consider lower concentrations of Mg in the water, in the range of 10% of the total daily intake of Mg.Future research efforts must give better answers to low Mg concentrations in the drinking water, before any concrete recommendations are given to the public. Moreover, the researchers must also determine which chemical form of Mg is most easily absorbed and has the greatest impact.Additional research is necessary in order to further investigate the interrelation between different water and food components as well as individual risk factors in the pathogenesis of CVD.

  16. Sulfate reducing bacteria and their activities in oil sands process-affected water biofilm

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hong; Yu, Tong, E-mail: tong.yu@ualberta.ca; Liu, Yang, E-mail: yang.liu@ualberta.ca

    2015-12-01

    Biofilm reactors were constructed to grow stratified multispecies biofilm in oil sands process-affected water (OSPW) supplemented with growth medium. The development of sulfate reducing bacteria (SRB) within the biofilm and the biofilm treatment of OSPW were evaluated. The community structure and potential activity of SRB in the biofilm were investigated with H{sub 2}S microsensor measurements, dsrB gene-based denaturing gradient gel electrophoresis (DGGE), and the real time quantitative polymerase chain reaction (qPCR). Multispecies biofilm with a thickness of 1000 μm was successfully developed on engineered biocarriers. H{sub 2}S production was observed in the deeper anoxic zone of the biofilm from around 750 μm to 1000 μm below the bulk water-biofilm interface, revealing sulfate reduction in the deeper zone of the stratified biofilm. The biofilm removed chemical oxygen demand (COD), sulfate, and nitrogen. The study expands current knowledge of biofilm treatment of OSPW and the function of anaerobic SRB in OSPW biofilm, and thus provides information for future bioreactor development in the reclamation of OSPW. - Graphical abstract: The development of sulfate reducing bacteria (SRB) within Oil Sands Process-affected Water (OSPW) biofilm and the biofilm treatment of OSPW were evaluated by Liu and coworkers. Combined microsensor and molecular biology techniques were utilized in this study. Their results demonstrated that multispecies biofilm with a thickness of 1000 μm was successfully developed on engineered biocarriers. H{sub 2}S production was observed in the deeper anoxic zone of the biofilm from around 750 μm to 1000 μm below the bulk water-biofilm interface, revealing sulfate reduction in the deeper zone of the biofilm. The biofilm removed chemical oxygen demand (COD), sulfate, and nitrogen. - Highlights: • Biofilm in oil sands wastewater was developed on engineered biocarriers. • Bacterial community and in situ activity of SRB were studied in the

  17. Methodological approaches for studying the microbial ecology of drinking water distribution systems.

    Science.gov (United States)

    Douterelo, Isabel; Boxall, Joby B; Deines, Peter; Sekar, Raju; Fish, Katherine E; Biggs, Catherine A

    2014-11-15

    The study of the microbial ecology of drinking water distribution systems (DWDS) has traditionally been based on culturing organisms from bulk water samples. The development and application of molecular methods has supplied new tools for examining the microbial diversity and activity of environmental samples, yielding new insights into the microbial community and its diversity within these engineered ecosystems. In this review, the currently available methods and emerging approaches for characterising microbial communities, including both planktonic and biofilm ways of life, are critically evaluated. The study of biofilms is considered particularly important as it plays a critical role in the processes and interactions occurring at the pipe wall and bulk water interface. The advantages, limitations and usefulness of methods that can be used to detect and assess microbial abundance, community composition and function are discussed in a DWDS context. This review will assist hydraulic engineers and microbial ecologists in choosing the most appropriate tools to assess drinking water microbiology and related aspects. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Microbiome of free-living amoebae isolated from drinking water.

    Science.gov (United States)

    Delafont, Vincent; Brouke, Amélie; Bouchon, Didier; Moulin, Laurent; Héchard, Yann

    2013-12-01

    Free-living amoebae (FLA) are protozoa that can be found in water networks where they prey on bacteria within biofilms. Most bacteria are digested rapidly by phagocytosis, however some are able to survive within amoebae and some are even able to multiply, as it is the case for Legionella pneumophila. These resisting bacteria are a potential health problem as they could also resist to macrophage phagocytosis. Several publications already reported intra-amoebal bacteria but the methods of identification did not allow metagenomic analysis and are partly based on co-culture with one selected amoebal strain. The aim of our study was to conduct a rRNA-targeted metagenomic analysis on amoebae and intra-amoebal bacteria found in drinking water network, to provide the first FLA microbiome in environmental strains. Three sites of a water network were sampled during four months. Culturable FLA were isolated and total DNA was prepared, allowing purification of both amoebal and bacterial DNA. Metagenomic studies were then conducted through 18S or 16S amplicons sequencing. Hartmannella was by far the most represented genus of FLA. Regarding intra-amoebal bacteria, 54 genera were identified, among which 21 were newly described intra-amoebal bacteria, underlying the power of our approach. There were high differences in bacterial diversity between the three sites. Several genera were highly represented and/or found at least in two sites, underlying that these bacteria could be able to multiply within FLA. Our method is therefore useful to identify FLA microbiome and could be applied to other networks to have a more comprehensive view of intra-amoebal diversity.

  19. Managing peatland vegetation for drinking water treatment

    Science.gov (United States)

    Ritson, Jonathan P.; Bell, Michael; Brazier, Richard E.; Grand-Clement, Emilie; Graham, Nigel J. D.; Freeman, Chris; Smith, David; Templeton, Michael R.; Clark, Joanna M.

    2016-11-01

    Peatland ecosystem services include drinking water provision, flood mitigation, habitat provision and carbon sequestration. Dissolved organic carbon (DOC) removal is a key treatment process for the supply of potable water downstream from peat-dominated catchments. A transition from peat-forming Sphagnum moss to vascular plants has been observed in peatlands degraded by (a) land management, (b) atmospheric deposition and (c) climate change. Here within we show that the presence of vascular plants with higher annual above-ground biomass production leads to a seasonal addition of labile plant material into the peatland ecosystem as litter recalcitrance is lower. The net effect will be a smaller litter carbon pool due to higher rates of decomposition, and a greater seasonal pattern of DOC flux. Conventional water treatment involving coagulation-flocculation-sedimentation may be impeded by vascular plant-derived DOC. It has been shown that vascular plant-derived DOC is more difficult to remove via these methods than DOC derived from Sphagnum, whilst also being less susceptible to microbial mineralisation before reaching the treatment works. These results provide evidence that practices aimed at re-establishing Sphagnum moss on degraded peatlands could reduce costs and improve efficacy at water treatment works, offering an alternative to ‘end-of-pipe’ solutions through management of ecosystem service provision.

  20. Occurrence of neonicotinoid insecticides in finished drinking water and fate during drinking water treatment

    Science.gov (United States)

    Klarich, Kathryn L.; Pflug, Nicholas C.; DeWald, Eden M.; Hladik, Michelle; Kolpin, Dana W.; Cwiertny, David M.; LeFevre, Gergory H.

    2017-01-01

    Neonicotinoid insecticides are widespread in surface waters across the agriculturally-intensive Midwestern US. We report for the first time the presence of three neonicotinoids in finished drinking water and demonstrate their general persistence during conventional water treatment. Periodic tap water grab samples were collected at the University of Iowa over seven weeks in 2016 (May-July) after maize/soy planting. Clothianidin, imidacloprid, and thiamethoxam were ubiquitously detected in finished water samples and ranged from 0.24-57.3 ng/L. Samples collected along the University of Iowa treatment train indicate no apparent removal of clothianidin and imidacloprid, with modest thiamethoxam removal (~50%). In contrast, the concentrations of all neonicotinoids were substantially lower in the Iowa City treatment facility finished water using granular activated carbon (GAC) filtration. Batch experiments investigated potential losses. Thiamethoxam losses are due to base-catalyzed hydrolysis at high pH conditions during lime softening. GAC rapidly and nearly completely removed all three neonicotinoids. Clothianidin is susceptible to reaction with free chlorine and may undergo at least partial transformation during chlorination. Our work provides new insights into the persistence of neonicotinoids and their potential for transformation during water treatment and distribution, while also identifying GAC as an effective management tool to lower neonicotinoid concentrations in finished drinking water.

  1. Should children drink more water?: the effects of drinking water on cognition in children.

    Science.gov (United States)

    Edmonds, Caroline J; Burford, Denise

    2009-06-01

    While dehydration has well-documented negative effects on adult cognition, there is little research on hydration and cognitive performance in children. We investigated whether having a drink of water improved children's performance on cognitive tasks. Fifty-eight children aged 7-9 years old were randomly allocated to a group that received additional water or a group that did not. Results showed that children who drank additional water rated themselves as significantly less thirsty than the comparison group (p=0.002), and they performed better on visual attention tasks (letter cancellation, p=0.02; spot the difference memory tasks, ps=0.019 and 0.014).

  2. 21 CFR 520.2240a - Sulfaethoxypyridazine drinking water.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sulfaethoxypyridazine drinking water. 520.2240a Section 520.2240a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Sulfaethoxypyridazine drinking water. (a) Chemical name. N′-(6-Ethoxy-3-pyridazinyl) sulfanilamide. (b)...

  3. TAPWAT: Definition structure and applications for modelling drinking water treatment

    NARCIS (Netherlands)

    Versteegh JFM; Gaalen FW van; Rietveld LC; Evers EG; Aldenberg TA; Cleij P; Technische Universiteit Delft; LWD

    2001-01-01

    The 'Tool for the Analysis of the Production of drinking WATer' (TAPWAT) model has been developed for describing drinking-water quality in integral studies in the context of the Environmental Policy Assessment of the RIVM. The model consists of modules that represent individual steps in a treatment

  4. Hydraulic modelling of drinking water treatment plant operations

    NARCIS (Netherlands)

    Worm, G.I.M.; Mesman, G.A.M.; Van Schagen, K.M.; Borger, K.J.; Rietveld, L.C.

    2009-01-01

    The flow through a unit of a drinking water treatment plant is one of the most important parameters in terms of a unit's effectiveness. In the present paper, a new EPAnet library is presented with the typical hydraulic elements for drinking water treatment processes well abstraction, rapid sand filt

  5. TAPWAT: Definition structure and applications for modelling drinking water treatment

    NARCIS (Netherlands)

    Versteegh JFM; Gaalen FW van; Rietveld LC; Evers EG; Aldenberg TA; Cleij P; Technische Universiteit Delft; LWD

    2001-01-01

    The 'Tool for the Analysis of the Production of drinking WATer' (TAPWAT) model has been developed for describing drinking-water quality in integral studies in the context of the Environmental Policy Assessment of the RIVM. The model consists of modules that represent individual steps in a treatment

  6. Availability of drinking water in US public school cafeterias.

    Science.gov (United States)

    Hood, Nancy E; Turner, Lindsey; Colabianchi, Natalie; Chaloupka, Frank J; Johnston, Lloyd D

    2014-09-01

    This study examined the availability of free drinking water during lunchtime in US public schools, as required by federal legislation beginning in the 2011-2012 school year. Data were collected by mail-back surveys in nationally representative samples of US public elementary, middle, and high schools from 2009-2010 to 2011-2012. Overall, 86.4%, 87.4%, and 89.4% of students attended elementary, middle, and high schools, respectively, that met the drinking water requirement. Most students attended schools with existing cafeteria drinking fountains and about one fourth attended schools with water dispensers. In middle and high schools, respondents were asked to indicate whether drinking fountains were clean, and whether they were aware of any water-quality problems at the school. The vast majority of middle and high school students (92.6% and 90.4%, respectively) attended schools where the respondent perceived drinking fountains to be clean or very clean. Approximately one in four middle and high school students attended a school where the survey respondent indicated that there were water-quality issues affecting drinking fountains. Although most schools have implemented the requirement to provide free drinking water at lunchtime, additional work is needed to promote implementation at all schools. School nutrition staff at the district and school levels can play an important role in ensuring that schools implement the drinking water requirement, as well as promote education and behavior-change strategies to increase student consumption of water at school.

  7. Integrated modeling of ozonation for optimization of drinking water treatment

    NARCIS (Netherlands)

    van der Helm, A.W.C.

    2007-01-01

    Drinking water treatment plants automation becomes more sophisticated, more on-line monitoring systems become available and integration of modeling environments with control systems becomes easier. This gives possibilities for model-based optimization. In operation of drinking water treatment plants

  8. Integrated modeling of ozonation for optimization of drinking water treatment

    NARCIS (Netherlands)

    van der Helm, A.W.C.

    2007-01-01

    Drinking water treatment plants automation becomes more sophisticated, more on-line monitoring systems become available and integration of modeling environments with control systems becomes easier. This gives possibilities for model-based optimization. In operation of drinking water treatment plants

  9. Studies on Disinfection By-Products and Drinking Water

    Science.gov (United States)

    Rostad, Colleen E.

    2007-01-01

    Drinking water is disinfected with chemicals to remove pathogens, such as Giardia and Cryptosproridium, and prevent waterborne diseases such as cholera and typhoid. During disinfection, by-products are formed at trace concentrations. Because some of these by-products are suspected carcinogens, drinking water utilities must maintain the effectiveness of the disinfection process while minimizing the formation of by-products.

  10. An environmental assessment of United States drinking water watersheds

    Science.gov (United States)

    James Wickham; Timothy Wade; Kurt Riitters

    2011-01-01

    Abstract There is an emerging recognition that natural lands and their conservation are important elements of a sustainable drinking water infrastructure. We conducted a national, watershed-level environmental assessment of 5,265 drinking water watersheds using data on land cover, hydrography and conservation status. Approximately 78% of the conterminous United States...

  11. Reducing Lead in Drinking Water: A Manual for Minnesota's Schools.

    Science.gov (United States)

    Minnesota State Dept. of Health, St. Paul.

    This manual was designed to assist Minnesota's schools in minimizing the consumption of lead in drinking water by students and staff. It offers step-by-step instructions for testing and reducing lead in drinking water. The manual answers: Why is lead a health concern? How are children exposed to lead? Why is lead a special concern for schools? How…

  12. Reducing Lead in School Drinking Water: A Case Study.

    Science.gov (United States)

    Odell, Lee

    1991-01-01

    The Seattle School District began a program in 1990 to identify lead levels in the district's drinking water and to implement measures to lower any high lead levels. Recounts each of the seven steps of the program, discusses what the district found, and explains how it lowered lead levels in the drinking water. (MLF)

  13. Meeting drinking water and sanitation targets of MDGs. Water use & competition in sub-Saharan Africa

    NARCIS (Netherlands)

    Hoek van der, Marjolijn

    2006-01-01

    Access to safe drinking water and improved sanitation is of vital importance for human beings. Improving the access to safe drinking water and improved sanitation in developing countries is therefore one of the Millennium Development Goals (MDGs) to be me

  14. Nitrates in drinking water and the risk of death from rectal cancer: does hardness in drinking water matter?

    Science.gov (United States)

    Chang, Chih-Ching; Chen, Chih-Cheng; Wu, Deng-Chuang; Yang, Chun-Yuh

    2010-01-01

    The objectives of this study were to (1) examine the relationship between nitrate levels in public water supplies and increased risk of death from rectal cancer and (2) determine whether calcium (Ca) and magnesium (Mg) levels in drinking water might modify the effects of nitrate on development of rectal cancer. A matched case-control study was used to investigate the relationship between the risk of death from rectal cancer and exposure to nitrate in drinking water in Taiwan. All rectal cancer deaths of Taiwan residents from 2003 through 2007 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to the cases by gender, year of birth, and year of death. Information on the levels of nitrate-nitrogen (NO(3)-N), Ca, and Mg in drinking water was collected from Taiwan Water Supply Corporation (TWSC). The municipality of residence for cancer cases and controls was presumed to be the source of the subject's NO(3)-N, Ca, and Mg exposure via drinking water. Relative to individuals whose NO(3)-N exposure level was water with a NO(3)-N exposure > or =0.38 ppm. There was no apparent evidence of an interaction between drinking water NO(3)-N levels with low Mg intake via drinking water. However, evidence of a significant interaction was noted between drinking-water NO(3)-N concentrations and Ca intake via drinking water. Our findings showed that the correlation between NO(3)-N exposure and risk of rectal cancer development was influenced by Ca in drinking water. This is the first study to report effect modification by Ca intake from drinking water on the association between NO(3)-N exposure and risk of rectal cancer occurrence. Increased knowledge of the mechanistic interaction between Ca and NO(3)-N in reducing rectal cancer risk will aid in public policymaking and setting threshold standards.

  15. Trihalomethanes in drinking water and the risk of death from rectal cancer: does hardness in drinking water matter?

    Science.gov (United States)

    Kuo, Hsin-Wei; Chen, Pei-Shih; Ho, Shu-Chen; Wang, Li-Yu; Yang, Chun-Yuh

    2010-01-01

    The objectives of this study were (1) to examine the relationship between total trihalomethanes (TTHM) levels in public water supplies and risk of rectal cancer development and (2) to determine whether calcium (Ca) and magnesium (Mg) levels in drinking water might modify the effects of TTHM on risk of developing rectal cancer. A matched cancer case-control study was used to investigate the relationship between the risk of death attributed to rectal cancer and exposure to TTHM in drinking water in 53 municipalities in Taiwan. All rectal cancer deaths in the 53 municipalities from 1998 through 2007 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to cancer cases by gender, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each cancer case. Data on TTHM levels in drinking water were collected from the Taiwan Environmental Protection Administration. Information on the levels of Ca and Mg in drinking water was obtained from the Taiwan Water Supply Corporation. The municipality of residence for cancer cases and controls was presumed to be the source of the subject's TTHM, Ca, and Mg exposure via drinking water. Relative to individuals whose TTHM exposure level was water with a TTHM exposure >or=4.9 ppb. There was no evidence of an interaction of drinking-water TTHM levels with low Ca intake via drinking water. However, evidence of an interaction was noted between drinking-water TTHM concentrations and Mg intake via drinking water. Our findings showed that the correlation between TTHM exposure and risk of rectal cancer is influenced by Mg in drinking water. Increased knowledge of the interaction between Mg and TTHM in reducing rectal cancer risk will aid in public policymaking and standard setting.

  16. [Features of legionella biofilm formation in artificial and natural water systems].

    Science.gov (United States)

    Dronina, Iu E; Karpova, T I; Sadretdinova, O V; Didenko, L V; Tartakovskiĭ, I S

    2012-01-01

    Study the ability to form monospecies and associative biofilms as a characteristic oflegionella strains and features of organization of natural legionella biofilms in potentially dangerous water systems. Comparative evaluation ofthe ability of 28 strains of Legionella spp. to form biofilms was determined in water according to previously developed procedure. Samples from biofilm of industrial enterprise coolers and systems of hot water supply of public buildings (hotels, trade centers, hospitals) were studied. Biofilms were studied by scanning and transmission electron microscopy methods. Legionella strains are divided into 3 groups by the ability to form biofilms. L. pneumophila BLR-05 strain that has the most pronounced ability to form monospecies biofilm and persistence in association with Pseudomonas aeruginosa was detected. Formation of massive legionella biofilm in association with bacteria of other taxonomic groups was detected on protective antibacterial filters in the system of hot water supply of a department of a therapeutic prophylaxis institution in the course of 2-3 weeks. Legionella biofilms on the surface of coolers resemble an aggregate of fungi, bacteria and blue-green algae enclosed into matrix. The ability to form artificial monospecies and associative biofilm may be a useful characteristic of legionella strains for evaluation of their adhesion and be used to evaluate epidemiological significance of the isolated strains. Prevention of formation of natural legionella biofilms in potentially dangerous water systems is necessary as an essential component of modern strategy of legionellosis prophylaxis.

  17. Growth kinetics of coliform bacteria under conditions relevant to drinking water distribution systems.

    Science.gov (United States)

    Camper, A K; McFeters, G A; Characklis, W G; Jones, W L

    1991-08-01

    The growth of environmental and clinical coliform bacteria under conditions typical of drinking water distribution systems was examined. Four coliforms (Klebsiella pneumoniae, Escherichia coli, Enterobacter aerogenes, and Enterobacter cloacae) were isolated from an operating drinking water system for study; an enterotoxigenic E. coli strain and clinical isolates of K. pneumoniae and E. coli were also used. All but one of the coliforms tested were capable of growth in unsupplemented mineral salts medium; the environmental isolates had greater specific growth rates than did the clinical isolates. This trend was maintained when the organisms were grown with low levels (less than 1 mg liter-1) of yeast extract. The environmental K. pneumoniae isolate had a greater yield, higher specific growth rates, and a lower Ks value than the other organisms. The environmental E. coli and the enterotoxigenic E. coli strains had comparable yield, growth rate, and Ks values to those of the environmental K. pneumoniae strain, and all three showed significantly more successful growth than the clinical isolates. The environmental coliforms also grew well at low temperatures on low concentrations of yeast extract. Unsupplemented distribution water from the collaborating utility supported the growth of the environmental isolates. Growth of the K. pneumoniae water isolate was stimulated by the addition of autoclaved biofilm but not by tubercle material. These findings indicate that growth of environmental coliforms is possible under the conditions found in operating municipal drinking water systems and that these bacteria could be used in tests to determine assimilable organic carbon in potable water.

  18. Assessment of changes in drinking water quality during distribution ...

    African Journals Online (AJOL)

    ... turbidity, feacal coliforms, manganese, lead, zinc and residual chlorine. ... Tap water at Area 25 Township is generally safe for human consumption. Key words: Drinking water, distribution system, biochemical parameters, human health.

  19. Drinking Water Quality in Hospitals and Other Buildings

    Science.gov (United States)

    Drinking water quality entering large buildings is generally adequately controlled by the water utility, but localized problems may occur within building or “premise” plumbing. Particular concerns are loss of disinfectant residual and temperature variability, which may enhance pa...

  20. 75 FR 61751 - National Drinking Water Advisory Council: Request for Nominations

    Science.gov (United States)

    2010-10-06

    ... AGENCY National Drinking Water Advisory Council: Request for Nominations AGENCY: Environmental Protection... National Drinking Water Advisory Council (Council). This 15-member Council was established by the Safe Drinking Water Act (SDWA) to provide practical and independent advice, consultation and recommendations...

  1. Comparison of biofilm formation and water quality when water from different sources was stored in large commercial water storage tanks.

    Science.gov (United States)

    van der Merwe, Venessa; Duvenage, Stacey; Korsten, Lise

    2013-03-01

    Rain-, ground- and municipal potable water were stored in low density polyethylene storage tanks for a period of 90 days to determine the effects of long-term storage on the deterioration in the microbial quality of the water. Total viable bacteria present in the stored water and the resultant biofilms were enumerated using heterotrophic plate counts. Polymerase chain reaction (PCR) and Colilert-18(®) tests were performed to determine if the faecal indicator bacteria Escherichia coli was present in the water and in the biofilm samples collected throughout the study. The municipal potable water at the start of the study was the only water source that conformed to the South African Water Quality Guidelines for Domestic Use. After 15 days of storage, this water source had deteriorated microbiologically to levels considered unfit for human consumption. E. coli was detected in the ground- and potable water and ground- and potable biofilms periodically, whereas it was detected in the rainwater and associated biofilms at every sampling point. Imperfections in the UV resistant inner lining of the tanks were shown to be ecological niches for microbial colonisation and biofilm development. The results from the current study confirmed that long-term storage can influence water quality and increase the number of microbial cells associated with biofilms on the interior surfaces of water storage tanks.

  2. Sulfate reducing bacteria and their activities in oil sands process-affected water biofilm.

    Science.gov (United States)

    Liu, Hong; Yu, Tong; Liu, Yang

    2015-12-01

    Biofilm reactors were constructed to grow stratified multispecies biofilm in oil sands process-affected water (OSPW) supplemented with growth medium. The development of sulfate reducing bacteria (SRB) within the biofilm and the biofilm treatment of OSPW were evaluated. The community structure and potential activity of SRB in the biofilm were investigated with H2S microsensor measurements, dsrB gene-based denaturing gradient gel electrophoresis (DGGE), and the real time quantitative polymerase chain reaction (qPCR). Multispecies biofilm with a thickness of 1000 μm was successfully developed on engineered biocarriers. H2S production was observed in the deeper anoxic zone of the biofilm from around 750 μm to 1000 μm below the bulk water-biofilm interface, revealing sulfate reduction in the deeper zone of the stratified biofilm. The biofilm removed chemical oxygen demand (COD), sulfate, and nitrogen. The study expands current knowledge of biofilm treatment of OSPW and the function of anaerobic SRB in OSPW biofilm, and thus provides information for future bioreactor development in the reclamation of OSPW.

  3. Microbial quality of drinking water from microfiltered water dispensers.

    Science.gov (United States)

    Sacchetti, R; De Luca, G; Dormi, A; Guberti, E; Zanetti, F

    2014-03-01

    A comparison was made between the microbial quality of drinking water obtained from Microfiltered Water Dispensers (MWDs) and that of municipal tap water. A total of 233 water samples were analyzed. Escherichia coli (EC), enterococci (ENT), total coliforms (TC), Staphylococcus aureus, Pseudomonas aeruginosa and heterotrophic plate count (HPC) at 22 °C and 37 °C were enumerated. In addition, information was collected about the principal structural and functional characteristics of each MWD in order to study the various factors that might influence the microbial quality of the water. EC and ENT were not detected in any of the samples. TC were never detected in the tap water but were found in 5 samples taken from 5 different MWDs. S. aureus was found in a single sample of microfiltered water. P. aeruginosa was found more frequently and at higher concentrations in the samples collected from MWDs. The mean HPCs at 22 °C and 37 °C were significantly higher in microfiltered water samples compared to those of the tap water. In conclusion, the use of MWDs may increase the number of bacteria originally present in tap water. It is therefore important to monitor the quality of the dispensed water over time, especially if it is destined for vulnerable users.

  4. Drinking water from private wells and risks to children.

    Science.gov (United States)

    Rogan, Walter J; Brady, Michael T

    2009-06-01

    Drinking water for approximately one sixth of US households is obtained from private wells. These wells can become contaminated by pollutant chemicals or pathogenic organisms and cause illness. Although the US Environmental Protection Agency and all states offer guidance for construction, maintenance, and testing of private wells, there is little regulation. With few exceptions, well owners are responsible for their own wells. Children may also drink well water at child care or when traveling. Illness resulting from children's ingestion of contaminated water can be severe. This policy statement provides recommendations for inspection, testing, and remediation for wells providing drinking water for children.

  5. Fixed-biofilm reactors applied to waste water treatment and aquacultural water recirculating systems

    NARCIS (Netherlands)

    Bovendeur, J.

    1989-01-01

    Fixed-biofilm waste water treatment may be regarded as one of the oldest engineered biological waste water treatment methods. With the recent introduction of modern packing materials, this type of reactor has received a renewed impuls for implementation in a wide field of water treatment.

    In

  6. Fixed-biofilm reactors applied to waste water treatment and aquacultural water recirculating systems.

    NARCIS (Netherlands)

    Bovendeur, J.

    1989-01-01

    Fixed-biofilm waste water treatment may be regarded as one of the oldest engineered biological waste water treatment methods. With the recent introduction of modern packing materials, this type of reactor has received a renewed impuls for implementation in a wide field of water treatment.In this the

  7. Safe drinking water: Experience with Water Safety Plans and assessment of risk factors in water supply

    OpenAIRE

    María J. Gunnarsdóttir 1947

    2012-01-01

    Access to adequate and clean drinking water is one of the fundamentals of a good and prosperous society. A comprehensive regulatory framework as well as institutional guidelines and procedures are necessary to secure this at any time. Iceland was one of the first countries to categorize drinking water as food in legislation passed in 1995. According to the legislation water utilities are obligated to implement systematic preventive management, Water Safety Plan (WSP), to ensure good quality w...

  8. Trihalomethanes in drinking water and the risk of death from esophageal cancer: does hardness in drinking water matter?

    Science.gov (United States)

    Tsai, Shang-Shyue; Chiu, Hui-Fen; Yang, Chun-Yuh

    2013-01-01

    The objectives of this study were to (1) examine the relationship between total trihalomethanes (TTHM) levels in public water supplies and risk of esophageal cancer occurrence and (2) determine whether calcium (Ca) and magnesium (Mg) levels in drinking water modify the effects of TTHM on risk to develop esophageal cancer. A matched case-control study was used to investigate the relationship between the risk of death attributed to esophageal cancer and exposure to TTHM in drinking water in 53 municipalities in Taiwan. All esophageal cancer deaths in the 53 municipalities from 2006 through 2010 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to the cancer cases by gender, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each cancer case. Data on TTHM levels in drinking water were collected from Taiwan Environmental Protection Administration. Information on the levels of Ca and Mg in drinking water was obtained from the Taiwan Water Supply Corporation. The municipality of residence for cancer cases and controls was presumed to be the source of the subject's TTHM, Ca, and Mg exposure via drinking water. Relative to individuals whose TTHM exposure level water with a TTHM exposure ≥4.9 ppb. There was evidence of an interaction between drinking-water TTHM levels and low Ca and Mg intake. Our findings showed that the correlation between TTHM exposure and risk of esophageal cancer development was influenced by Ca and Mg levels in drinking water. This is the first study to report effect modification by Ca and Mg intake from drinking water on the correlation between TTHM exposure and risk of esophageal cancer occurrence. Increased knowledge of the interaction between Ca, Mg, and TTHM in reducing risk of esophageal cancer development will aid in public policymaking and standard setting for drinking

  9. Analysis of black fungal biofilms occurring at domestic water taps (II): Potential routes of entry

    NARCIS (Netherlands)

    Heinrichs, G.; Hübner, I.; Schmidt, C.K.; de Hoog, G.S.; Haase, G.

    2013-01-01

    Formation of tenacious and massive black biofilms was occasionally observed at the water-air interphase of water taps and in associated habitats at several locations in Germany. Exophiala lecanii-corni was proven to be the dominant component of these biofilms. Water utility companies were interested

  10. Analysis of black fungal biofilms occurring at domestic water taps (II): Potential routes of entry

    NARCIS (Netherlands)

    G. Heinrichs; I. Hübner; C.K. Schmidt; G.S. de Hoog; G. Haase

    2013-01-01

    Formation of tenacious and massive black biofilms was occasionally observed at the water-air interphase of water taps and in associated habitats at several locations in Germany. Exophiala lecanii-corni was proven to be the dominant component of these biofilms. Water utility companies were interested

  11. Fluoride content in bottled drinking waters, carbonated soft drinks and fruit juices in Davangere city, India

    Directory of Open Access Journals (Sweden)

    Thippeswamy H

    2010-01-01

    Full Text Available Background: The regular ingestion of fluoride lowers the prevalence of dental caries. The total daily intake of fluoride for optimal dental health should be 0.05-0.07 mg fluoride/kg body weight and to avoid the risk of dental fluorosis, the daily intake should not exceed a daily level of 0.10 mg fluoride/kg body weight. The main source of fluoride is from drinking water and other beverages. As in other countries, consumption of bottled water, juices and carbonated beverages has increased in our country. Objective: To analyze the fluoride content in bottled water, juices and carbonated soft drinks that were commonly available in Davangere city. Materials and Methods: Three samples of 10 commercially available brands of bottled drinking water, 12 fruit juices and 12 carbonated soft drinks were purchased. Bottled water and carbonated soft drinks were stored at a cold place until fluoride analysis was performed and a clear juice was prepared using different fruits without the addition of water. Then, the fluoride analysis was performed. Results: The mean and standard deviation of fluoride content of bottled water, fruit juices and carbonated soft drinks were measured, which were found to be 0.20 mg (±0.19 F/L, 0.29 mg (±0.06 F/L and 0.22 mg (±0.05 F/L, respectively. Conclusion: In viewing the results of the present study, it can be concluded that regulation of the optimal range of fluoride in bottled drinking water, carbonated soft drinks and fruit juices should be drawn for the Indian scenario.

  12. Fluoride content in bottled drinking waters, carbonated soft drinks and fruit juices in Davangere city, India.

    Science.gov (United States)

    Thippeswamy, H M; Kumar, Nanditha; Anand, S R; Prashant, G M; Chandu, G N

    2010-01-01

    The regular ingestion of fluoride lowers the prevalence of dental caries. The total daily intake of fluoride for optimal dental health should be 0.05-0.07 mg fluoride/kg body weight and to avoid the risk of dental fluorosis, the daily intake should not exceed a daily level of 0.10 mg fluoride/kg body weight. The main source of fluoride is from drinking water and other beverages. As in other countries, consumption of bottled water, juices and carbonated beverages has increased in our country. To analyze the fluoride content in bottled water, juices and carbonated soft drinks that were commonly available in Davangere city. Three samples of 10 commercially available brands of bottled drinking water, 12 fruit juices and 12 carbonated soft drinks were purchased. Bottled water and carbonated soft drinks were stored at a cold place until fluoride analysis was performed and a clear juice was prepared using different fruits without the addition of water. Then, the fluoride analysis was performed. The mean and standard deviation of fluoride content of bottled water, fruit juices and carbonated soft drinks were measured, which were found to be 0.20 mg (±0.19) F/L, 0.29 mg (±0.06) F/L and 0.22 mg (±0.05) F/L, respectively. In viewing the results of the present study, it can be concluded that regulation of the optimal range of fluoride in bottled drinking water, carbonated soft drinks and fruit juices should be drawn for the Indian scenario.

  13. An assessment of drinking-water quality post-Haiyan.

    Science.gov (United States)

    Magtibay, Bonifacio; Anarna, Maria Sonabel; Fernando, Arturo

    2015-01-01

    Access to safe drinking-water is one of the most important public health concerns in an emergency setting. This descriptive study reports on an assessment of water quality in drinking-water supply systems in areas affected by Typhoon Haiyan immediately following and 10 months after the typhoon. Water quality testing and risk assessments of the drinking-water systems were conducted three weeks and 10 months post-Haiyan. Portable test kits were used to determine the presence of Escherichia coli and the level of residual chlorine in water samples. The level of risk was fed back to the water operators for their action. Of the 121 water samples collected three weeks post-Haiyan, 44% were contaminated, while 65% (244/373) of samples were found positive for E. coli 10 months post-Haiyan. For the three components of drinking-water systems - source, storage and distribution - the proportions of contaminated systems were 70%, 67% and 57%, respectively, 10 months after Haiyan. Vulnerability to faecal contamination was attributed to weak water safety programmes in the drinking-water supply systems. Poor water quality can be prevented or reduced by developing and implementing a water safety plan for the systems. This, in turn, will help prevent waterborne disease outbreaks caused by contaminated water post-disaster.

  14. Does calcium in drinking water modify the association between nitrate in drinking water and risk of death from colon cancer?

    Science.gov (United States)

    Chiu, Hui-Fen; Tsai, Shang-Shyue; Chen, Pei-Shih; Wu, Trong-Neng; Yang, Chun-Yuh

    2011-09-01

    The objective of this study was to explore whether calcium (Ca) levels in drinking water modified the effects of nitrate on colon cancer risk. A matched case-control study was used to investigate the relationship between the risk of death from colon cancer and exposure to nitrate in drinking water in Taiwan. All colon cancer deaths of Taiwan residents from 2003 through 2007 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to the cases by gender, year of birth and year of death. Information on the levels of nitrate-nitrogen (NO(3)-N) and Ca in drinking water have been collected from Taiwan Water Supply Corporation (TWSC). The municipality of residence for cases and controls was assumed to be the source of the subject's NO(3)-N and Ca exposure via drinking water. We observed evidence of an interaction between drinking water NO(3)-N and Ca intake via drinking water. This is the first study to report effect modification by Ca intake from drinking water on the association between NO(3)-N exposure and risk of colon cancer mortality.

  15. Pseudomonas-related populations associated with reverse osmosis in drinking water treatment.

    Science.gov (United States)

    Sala-Comorera, Laura; Blanch, Anicet R; Vilaró, Carles; Galofré, Belén; García-Aljaro, Cristina

    2016-11-01

    Reverse osmosis membrane filtration technology (RO) is used to treat drinking water. After RO treatment, bacterial growth is still observed in water. However, it is not clear whether those microorganisms belong to species that can pose a health risk, such as Pseudomonas spp. The goal of this study is to characterize the bacterial isolates from a medium that is selective for Pseudomonas and Aeromonas which were present in the water fraction before and after the RO. To this end, isolates were recovered over two years and were identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. They were then biochemically phenotyped and the population similarity indexes were calculated. The isolates were analysed for their capacity to form biofilms in vitro and antimicrobial susceptibility. There were significant differences between the microbial populations in water before and after RO. Furthermore, the structures of the populations analysed at the same sampling point were similar in different sampling campaigns. Some of the isolates had the capacity to form a biofilm and showed resistance to different antibiotics. A successful level filtration via RO and subsequent recolonization of the membrane with different species from those in the feed water was found. Pseudomonas aeruginosa was not recovered from among the isolates. This study increases the knowledge on the microorganisms present in water after RO treatment, with focus in one of the genus causing problems in RO systems associated with human health risk, Pseudomonas.

  16. Time to revisit arsenic regulations: comparing drinking water and rice

    Science.gov (United States)

    2014-01-01

    Background Current arsenic regulations focus on drinking water without due consideration for dietary uptake and thus seem incoherent with respect to the risks arising from rice consumption. Existing arsenic guidelines are a cost-benefit compromise and, as such, they should be periodically re-evaluated. Discussion Literature data was used to compare arsenic exposure from rice consumption relative to exposure arising from drinking water. Standard risk assessment paradigms show that arsenic regulations for drinking water should target a maximum concentration of nearly zero to prevent excessive lung and bladder cancer risks (among others). A feasibility threshold of 3 μg As l-1 was determined, but a cost-benefit analysis concluded that it would be too expensive to target a threshold below 10 μg As l-1. Data from the literature was used to compare exposure to arsenic from rice and rice product consumption relative to drinking water consumption. The exposure to arsenic from rice consumption can easily be equivalent to or greater than drinking water exposure that already exceeds standard risks and is based on feasibility and cost-benefit compromises. It must also be emphasized that many may disagree with the implications for their own health given the abnormally high cancer odds expected at the cost-benefit arsenic threshold. Summary Tighter drinking water quality criteria should be implemented to properly protect people from excessive cancer risks. Food safety regulations must be put in place to prevent higher concentrations of arsenic in various drinks than those allowed in drinking water. Arsenic concentrations in rice should be regulated so as to roughly equate the risks and exposure levels observed from drinking water. PMID:24884827

  17. Organochlorine pesticides residues in bottled drinking water from Mexico City.

    Science.gov (United States)

    Díaz, Gilberto; Ortiz, Rutilio; Schettino, Beatriz; Vega, Salvador; Gutiérrez, Rey

    2009-06-01

    This work describes concentrations of organochlorine pesticides in bottled drinking water (BDW) in Mexico City. The results of 36 samples (1.5 and 19 L presentations, 18 samples, respectively) showed the presence of seven pesticides (HCH isomers, heptachlor, aldrin, and p,p'-DDE) in bottled water compared with the drinking water standards set by NOM-127-SSA1-1994, EPA, and World Health Organization. The concentrations of the majority of organochlorine pesticides were within drinking water standards (0.01 ng/mL) except for beta-HCH of BW 3, 5, and 6 samples with values of 0.121, 0.136, and 0.192 ng/mL, respectively. It is important monitoring drinking bottled water for protecting human health.

  18. Fixed-biofilm reactors applied to waste water treatment and aquacultural water recirculating systems

    OpenAIRE

    Bovendeur, J.

    1989-01-01

    Fixed-biofilm waste water treatment may be regarded as one of the oldest engineered biological waste water treatment methods. With the recent introduction of modern packing materials, this type of reactor has received a renewed impuls for implementation in a wide field of water treatment.

    In this thesis the possibilities are presented for fixed-film post-treatment of anaerobically digested domestic sewage and water reconditioning in aquacultural water recirculation systems. Emphasis i...

  19. Safe and Affordable Drinking Water for Developing Countries

    Science.gov (United States)

    Gadgil, Ashok

    2008-09-01

    Safe drinking water remains inaccessible for about 1.2 billion people in the world, and the hourly toll from biological contamination of drinking water is 200 deaths mostly among children under five years of age. This chapter summarizes the need for safe drinking water, the scale of the global problem, and various methods tried to address it. Then it gives the history and current status of an innovation ("UV Waterworks™") developed to address this major public health challenge. It reviews water disinfection technologies applicable to achieve the desired quality of drinking water in developing countries, and specifically, the limitations overcome by one particular invention: UV Waterworks. It then briefly describes the business model and financing option than is accelerating its implementation for affordable access to safe drinking water to the unserved populations in these countries. Thus this chapter describes not only the innovation in design of a UV water disinfection system, but also innovation in the delivery model for safe drinking water, with potential for long term growth and sustainability.

  20. Drinking water infrastructure and environmental disparities: evidence and methodological considerations.

    Science.gov (United States)

    VanDerslice, James

    2011-12-01

    Potable drinking water is essential to public health; however, few studies have investigated income or racial disparities in water infrastructure or drinking water quality. There were many case reports documenting a lack of piped water or serious water quality problems in low income and minority communities, including tribal lands, Alaskan Native villages, colonias along the United States-Mexico border, and small communities in agricultural areas. Only 3 studies compared the demographic characteristics of communities by the quality of their drinking water, and the results were mixed in these studies. Further assessments were hampered by difficulties linking specific water systems to the sociodemographic characteristics of communities, as well as little information about how well water systems operated and the effectiveness of governmental oversight.

  1. Drinking Water Infrastructure and Environmental Disparities: Evidence and Methodological Considerations

    Science.gov (United States)

    2011-01-01

    Potable drinking water is essential to public health; however, few studies have investigated income or racial disparities in water infrastructure or drinking water quality. There were many case reports documenting a lack of piped water or serious water quality problems in low income and minority communities, including tribal lands, Alaskan Native villages, colonias along the United States–Mexico border, and small communities in agricultural areas. Only 3 studies compared the demographic characteristics of communities by the quality of their drinking water, and the results were mixed in these studies. Further assessments were hampered by difficulties linking specific water systems to the sociodemographic characteristics of communities, as well as little information about how well water systems operated and the effectiveness of governmental oversight. PMID:21836110

  2. Modelling and simulation of a nitrification biofilter for drinking water ...

    African Journals Online (AJOL)

    2005-09-30

    Sep 30, 2005 ... surface area available for biofilm growth is 17 424 m². In the biofilter the total water volume for nitrification is 14.52 m³. The raw canal ... diffusion limitation. The major ..... First the effect of reducing the aeration of the biofilter was inves- tigated. ... day 200. Outside this period the DO ammonium ratio is higher.

  3. Arsenic drinking water regulations in developing countries with extensive exposure.

    Science.gov (United States)

    Smith, Allan H; Smith, Meera M Hira

    2004-05-20

    The United States Public Health Service set an interim standard of 50 microg/l in 1942, but as early as 1962 the US Public Health Service had identified 10 microg/l as a goal which later became the World Health Organization Guideline for drinking water in 1992. Epidemiological studies have shown that about one in 10 people drinking water containing 500 microg/l of arsenic over many years may die from internal cancers attributable to arsenic, with lung cancer being the surprising main contributor. A prudent public health response is to reduce the permissible drinking water arsenic concentrations. However, the appropriate regulatory response in those developing countries with large populations with much higher concentrations of arsenic in drinking water, often exceeding 100 microg/l, is more complex. Malnutrition may increase risks from arsenic. There is mounting evidence that smoking and arsenic act synergistically in causing lung cancer, and smoking raises issues of public health priorities in developing countries that face massive mortality from this product. Also, setting stringent drinking water standards will impede short term solutions such as shallow dugwells. Developing countries with large populations exposed to arsenic in water might reasonably be advised to keep their arsenic drinking water standards at 50 microg/l.

  4. [DIRECTIONALITY OF THE BIOLOGICAL EFFECT OF DRINKING WATER].

    Science.gov (United States)

    Gibert, K K; Karasev, A K; Marasanov, A V; Stekhin, A A; Iakovleva, G V

    2015-01-01

    There have been performed the studies of the dimensional parameters of peroxide associates in drinking water, per- forming regulatory functions in cellular metabolism, that determine the character of the biological response of the human body to drinking water The direction of action of peroxide associates type Σ [(HO2-(*) ... OH-(*) (H2O) tp)]q, (where (H2O) tp is an associate with the tetragonal structure (Walrafen pentamer Is ice VI), q is the degree of association p--parameter of ion coordination) on the cellular structures of the organism is associated with their quantum properties, determining the macroscopic parameters of the electron wave packets. Research has confirmed the addressness of the nonlocal entering electron to certain cellular structures of the body, which is determined by the structural similarity of centers of condensation of electrons in the cells of systems and organs of the body with the parameters of the electron wave packets in the associates. Methodology for the estimation of the orientation of biological effect of the drinking water to the systems of the body on the base of the analysis of variations in heart rhythm under non-contact influence of water on the human body and its relationship with the dimensional parameters and peroxide activity of associates in drinking water can be suggested for the implementation of screening tests for drinking water quality, taking into account both the individualfeatures of responses of body systems to drinking water and its group action.

  5. Monitoring drinking water quality in South Africa: Designing ...

    African Journals Online (AJOL)

    In South Africa, the management and monitoring of drinking water quality is governed by policies and regulations based .... The measures for improvement of monitoring were: .... purposes, the effectiveness and desirability of a government.

  6. IDENTIFICATION OF NEW DISINFECTION BY-PRODUCTS IN DRINKING WATER

    Science.gov (United States)

    Due to concern over the potential adverse health effects of trihalomethanes (THMs) and other chlorinated by-products in chlorinated drinking water, alternative disinfectants are being explored. Ozone, chlorine dioxide, and chloramine are popular alternatives, as they produce low...

  7. Optimal drinking water composition for caries control in populations

    DEFF Research Database (Denmark)

    Bruvo, M.; Ekstrand, K.; Arvin, Erik;

    2008-01-01

    Apart from the well-documented effect of fluoride in drinking water on dental caries, little is known about other chemical effects. Since other ions in drinking water may also theoretically influence caries, as well as binding of fluoride in the oral environment, we hypothesized that the effect...... of drinking water on caries may not be limited to fluoride only. Among 22 standard chemical variables, including 15 ions and trace elements as well as gases, organic compounds, and physical measures, iterative search and testing identified that calcium and fluoride together explained 45% of the variations...... in the numbers of decayed, filled, and missing tooth surfaces (DMF-S) among 52,057 15-year-old schoolchildren in 249 Danish municipalities. Both ions had reducing effects on DMF-S independently of each other, and could be used in combination for the design of optimal drinking water for caries control...

  8. Aircraft Drinking Water Rule Public Meetings and Summaries

    Science.gov (United States)

    In developing the Aircraft Drinking Water Rule, EPA used a collaborative process to obtain a broad range of views including the airlines, flight attendants, passengers, pilots, airports, laboratories, public health officials and environmental organizations

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

  11. ENVIRONMENTAL POLLUTION CONTROL ALTERNATIVES: DRINKING WATER TREATMENT FOR SMALL COMMUNITIES

    Science.gov (United States)

    This document provides information for small system owners, operators, managers, and local decision makers, such as town officials, regarding drinking water treatment requirements and the treatment technologies suitable for small systems. t is not intended to be a comprehensive m...

  12. Time to revisit arsenic regulations: comparing drinking water and rice

    National Research Council Canada - National Science Library

    Sauvé, Sébastien

    2014-01-01

    .... Standard risk assessment paradigms show that arsenic regulations for drinking water should target a maximum concentration of nearly zero to prevent excessive lung and bladder cancer risks (among others...

  13. REMOVAL OF URANIUM FROM DRINKING WATER BY CONVENTIONAL TREATMENT METHODS

    Science.gov (United States)

    The USEPA currently does not regulate uranium in drinking water but will be revising the radionuclide regulations during 1989 and will propose a maximum contaminant level for uranium. The paper presents treatment technology information on the effectiveness of conventional method...

  14. Safe Drinking Water Information System (SDWIS) Sewer Treatment Plants

    Data.gov (United States)

    U.S. Environmental Protection Agency — This is a point feature dataset showing the locations of sewer treatment plants. These facility locations are part of the safe drinking water information system...

  15. The generation of oxygen radicals after drinking of oxygenated water.

    Science.gov (United States)

    Schoenberg, M H; Hierl, T C; Zhao, J; Wohlgemuth, N; Nilsson, U A

    2002-03-28

    It has been speculated whether ingestion of oxygenated water can lead to an enhanced generation of oxygen radicals. The purpose of three prospective randomized blinded clinical studies was therefore to measure if, when and at which oxygen content in the water,drinking of oxygenated water induces the generation of radicals. Moreover in the fourth prospective,randomized, blinded study possible longterm effects of drinking oxygenated water were examined. Altogether 66 volunteers were drinking 300 ml oxygenated or tap water within 15 minutes. Before drinking, altogether 15 ml of blood from the antecubital vein was collected for determination of ascorbyl radicals with ESR, routine laboratory data (hemoglobin, erythrocytes, hematocrit, leukocytes, thrombocytes, uric acid) and the vitamins A,C,E by HPLC. After drinking the ascorbyl radical measurements were repeated from blood of the antecubital vein. In the longterm study ( fourth study) the volunteers had to undergo the same procedure, as described above, at day 1 and day 21. In the meantime they were drinking per day three times 300 ml either oxygenated water or tap water. All subjects exhibited normal vitamin levels in all three studies. Concommitantly in the fourth study there was no statistically relevant alteration of vitamin concentrations during the observation period of three weeks in the verum and placebo-group. 30 minutes after drinking oxygenated water the concentration of ascorbyl radicals increased significantly by median 42 % from median 48 to 65 nmol/l. This increase of ascorbyl radicals after 30 minutes was reproducible in all studies. The levels of ascorbyl radicals remained elevated for 60 minutes after drinking and returned to normal after 120 minutes. This increase was independent of the oxygen concentration in the water, beginning at 30 mg oxygen/l. Water containing 15 mg oxygen/l did not lead to an enhanced radical formation. Longterm consumption of oxygenated water attenuated the ascorbyl radical

  16. Occurrence of Legionella pneumophila and Hartmannella vermiformis in fresh water environments and their interactions in biofilms

    NARCIS (Netherlands)

    Kuiper, M.W.

    2006-01-01

    Legionella pneumophila, the causative agent of Legionnaires’ disease, is widespread in natural fresh water environments and is also frequently found in man-made water systems. Microbial biofilms and protozoa are known to play a major role in the proliferation of L. pneumophila. Biofilms provide shel

  17. Mutagenic activity of drinking water in Wroclaw, Poland.

    Science.gov (United States)

    Gasiorowski, K; Szyba, K; Sawicka, J; Gulanowski, B

    1993-01-01

    The Salmonella mutagenicity test was applied to the evaluation of mutagenic activity of Wroclaw drinking water. Contaminants of water samples were concentrated by adsorption on XAD-2 resin. After while they were eluted sequentially with acetone, dichloromethane/methanol (1:1, v/v) and methanol, and then obtained organic extracts were evaporated to dryness. The extracts were then dissolved in DMSO and examined by using the Ames test. The results proved significant contamination of drinking water with mutagenic substances. Hydroxyapatite column chromatography performed after direct incubation of standard DNA probes with tested water extracts showed that drinking water was contaminated with DNA interstrand cross-linking substances. Filtration of tap water through carbon filters markedly reduced mutagenic activity of tested water extracts, whereas ceramic filters were more efficient in depleting of DNA interstrand cross-linking contaminants.

  18. Lead in Drinking Water in Slovenian Kindergartens and Schools

    Directory of Open Access Journals (Sweden)

    Bitenc K.

    2013-04-01

    Full Text Available The purpose of the work is to determine how high are the concentrations of lead in drinking water in older Slovenian kindergartens and primary schools and to demonstrate that lead can also migrate from newer materials used for the construction of water distribution networks. To determine the concentrations of lead in drinking water, it is needed to take 250 ml of drinking water that stood in the pipes from 8 to 18hours. It is also applied a method for determining the migration from different materials. An old lead pipe is utilized, as well as new materials (PEX-Al-PEX, copper, galvanized pipes and stainless steel pipes. Sampling showed that 6 samples of 39 had levels of lead higher than 10 µg/l, two of them highly exceeded that level. Negative correlation between the level of pH and concentration of lead in drinking water is moderate. Implementation of lead migration from various types of pipes demonstrated the migration from galvanized pipes in all simulants. Furthermore, the migration of lead from galvanized pipes is dependent on water temperature. The migration was confirmed from the lead pipe as expected. Study points to a problem with elevated concentrations of lead in drinking water faced by older kindergartens and primary schools in Slovenia. All concentrations of lead after flushing the pipes were below the 10 µg/l, which shows that the most effective action to lower the concentrations of lead is flushing the water pipes. For the purposes of national monitoring of drinking water is necessary to apply a better method for determining lead levels in drinking water namely the sampling of water that stood in the pipes at least 8 to 18 hours. This study has demonstrated the migration of lead from galvanized pipes. This material is also installed in 54 % of kindergartens and primary schools that participated in the study.

  19. [Hygienic requirements on materials in contact with drinking water].

    Science.gov (United States)

    Schlosser, F-U; Schuster, R; Rapp, T

    2007-03-01

    In Germany the hygienic requirements on materials used to supply drinking water are a part of the technical standards. These regulations have to ensure that legal requirements on drinking water are met at the tap. The hygienic harmlessness is assured by requirements on the composition of materials and by test procedures including parametric limits. Historically, the requirements on different types of materials are a part of different technical standards.

  20. Arsenic contamination of drinking water and mental health

    OpenAIRE

    Chowdhury, Shyamal; Krause, Annabelle; Zimmermann, Klaus F.

    2016-01-01

    This paper investigates the effect of drinking arsenic contaminated water on mental health. Drinking water with an unsafe arsenic level for a prolonged period can lead to arsenicosis, which includes symptoms such as black spots on the skin and subsequent illnesses such as various cancers. We collected household survey data from Bangladesh, a country with wide arsenic contamination of groundwater to construct several measures for arsenic contamination that include the actual arsenic level in t...

  1. Monochloramine Cometabolism by Nitrifying Biofilm Relevant to Drinking Water

    Science.gov (United States)

    Recently, biological monochloramine removal (i.e., cometabolism) by a pure culture ammonia–oxidizing bacteria, Nitrosomonas europaea, and a nitrifying mixed–culture have been shown to increase monochloramine demand. Although important, these previous suspended culture batch kine...

  2. Monochloramine Cometabolism by Nitrifying Biofilm Relevant to Drinking Water

    Science.gov (United States)

    Recently, biological monochloramine removal (i.e., cometabolism) by a pure culture ammonia–oxidizing bacteria, Nitrosomonas europaea, and a nitrifying mixed–culture have been shown to increase monochloramine demand. Although important, these previous suspended cultur...

  3. Monochloramine Cometabolism by Nitrifying Biofilm Relevant to Drinking Water

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data for Figures in manuscript. This dataset is associated with the following publication: Wahman , D., J. Maestre, and G. Speitel Jr.. Monochloramine Cometabolism...

  4. Monochloramine Cometabolism by Nitrifying Biofilm Relevant to Drinking Water

    Science.gov (United States)

    Recently, biological monochloramine removal (i.e., cometabolism) by a pure culture ammonia–oxidizing bacteria, Nitrosomonas europaea, and a nitrifying mixed–culture have been shown to increase monochloramine demand. Although important, these previous suspended culture batch kine...

  5. Formation of disinfection byproducts in typical Chinese drinking water

    Institute of Scientific and Technical Information of China (English)

    Wenbo Liu; Yanmei Zhao; Christopher WK Chow; Dongsheng Wang

    2011-01-01

    Eight typical drinking water supplies in China were selected in this study.Both source and tap water were used to investigate the occurrence of chlorinated disinfection byproducts (DBPs), and seasonal variation in the concentrations of trihalomethanes (THMs) of seven water sources was compared.The results showed that the pollution level for source water in China, as shown by DBP formation potential, was low.The most encountered DBPs were chloroform, dichloroacetic acid, trichloroacetic acid, and chiorodibromoacetic acid.The concentration of every THMs and haloacetic acid (HAA) compound was under the limit of standards for drinking water quality.The highest total THMs concentrations were detected in spring.

  6. Formation of disinfection byproducts in typical Chinese drinking water.

    Science.gov (United States)

    Liu, Wenbo; Zhao, Yanmei; Chow, Christopher W K; Wang, Dongsheng

    2011-01-01

    Eight typical drinking water supplies in China were selected in this study. Both source and tap water were used to investigate the occurrence of chlorinated disinfection byproducts (DBPs), and seasonal variation in the concentrations of trihalomethanes (THMs) of seven water sources was compared. The results showed that the pollution level for source water in China, as shown by DBP formation potential, was low. The most encountered DBPs were chloroform, dichloroacetic acid, trichloroacetic acid, and chlorodibromoacetic acid. The concentration of every THMs and haloacetic acid (HAA) compound was under the limit of standards for drinking water quality. The highest total THMs concentrations were detected in spring.

  7. Isotopic Fingerprint for Phosphorus in Drinking Water Supplies.

    Science.gov (United States)

    Gooddy, Daren C; Lapworth, Dan J; Ascott, Matthew J; Bennett, Sarah A; Heaton, Timothy H E; Surridge, Ben W J

    2015-08-01

    Phosphate dosing of drinking water supplies, coupled with leakage from distribution networks, represents a significant input of phosphorus to the environment. The oxygen isotope composition of phosphate (δ(18)OPO4), a novel stable isotope tracer for phosphorus, offers new opportunities to understand the importance of phosphorus derived from sources such as drinking water. We report the first assessment of δ(18)OPO4 within drinking water supplies. A total of 40 samples from phosphate-dosed distribution networks were analyzed from across England and Wales. In addition, samples of the source orthophosphoric acid used for dosing were also analyzed. Two distinct isotopic signatures for drinking water were identified (average = +13.2 or +19.7‰), primarily determined by δ(18)OPO4 of the source acid (average = +12.4 or +19.7‰). Dependent upon the source acid used, drinking water δ(18)OPO4 appears isotopically distinct from a number of other phosphorus sources. Isotopic offsets from the source acid ranging from -0.9 to +2.8‰ were observed. There was little evidence that equilibrium isotope fractionation dominated within the networks, with offsets from temperature-dependent equilibrium ranging from -4.8 to +4.2‰. While partial equilibrium fractionation may have occurred, kinetic effects associated with microbial uptake of phosphorus or abiotic sorption and dissolution reactions may also contribute to δ(18)OPO4 within drinking water supplies.

  8. Infiltration of pesticides in surface water into nearby drinking water supply wells

    DEFF Research Database (Denmark)

    Malaguerra, Flavio; Albrechtsen, Hans-Jørgen; Binning, Philip John

    Drinking water wells are often placed near streams because streams often overly permeable sediments and the water table is near the surface in valleys, and so pumping costs are reduced. The lowering of the water table by pumping wells can reverse the natural flow from the groundwater to the stream......, inducing infiltration of surface water to groundwater and consequently to the drinking water well. Many attenuation processes can take place in the riparian zone, mainly due to mixing, biodegradation and sorption. However, if the water travel time from the surface water to the pumping well is too short......, or if the compounds are poorly degradable, contaminants can reach the drinking water well at high concentrations, jeopardizing drinking water quality. Here we developed a reactive transport model to evaluate the risk of contamination of drinking water wells by surface water pollution. The model was validated using...

  9. Physical, chemical and microbial analysis of bottled drinking water.

    Science.gov (United States)

    Sasikaran, S; Sritharan, K; Balakumar, S; Arasaratnam, V

    2012-09-01

    People rely on the quality of the bottled drinking water, expecting it to be free of microbial contamination and health hazards. To evaluate the quality of bottled drinking water sold in Jaffna peninsula by analysing the physical, chemical and microbial contents and comparing with the recommended Sri Lankan Standard (SLS) values. All bottled water samples sold in Jaffna peninsula were collected. Electrical conductivity, total dissolved solid, pH, calcium, nitrate, total aerobic and anaerobic count, coliform bacterial count and faecal contamination were checked. These are 22 brands of bottled drinking water sold in Jaffna peninsula. The sample had very low electrical conductivity when compared with SLS (750 μS/ cm) and varied from 19 to 253 μS/cm with the mean of 80.53 (±60.92) μS/cm. The pH values of the bottled drinking water brands varied from 4.11 to 7.58 with a mean of 6.2 (±0.75). The total dissolved solid content of the bottled drinking water brands varied from 9 to 123.67 mg/l with a mean of 39.5 (±30.23) mg/l. The calcium content of the bottled drinking water brands varied from 6.48 to 83.77 mg/l with a mean of 49.9 (±25.09) mg/l. The nitrate content of the bottled drinking water brands varied from 0.21 to 4.19 mg/l with the mean of 1.26 (±1.08) mg/l. Aerobic bacterial count varied from 0 to 800 colony forming unit per ml (cfu/ml) with a mean of 262.6 (±327.50) cfu/ml. Among the 22 drinking bottled water brands 14 and 9% of bottled drinking water brands showed fungal and coliform bacterial contaminants respectively. The water brands which contained faecal contamination had either Escherichia coli or Klebsiella spp. The bottled drinking water available for sale do not meet the standards stipulated by SLS.

  10. 75 FR 20352 - National Drinking Water Advisory Council's Climate Ready Water Utilities Working Group Meeting...

    Science.gov (United States)

    2010-04-19

    ... AGENCY National Drinking Water Advisory Council's Climate Ready Water Utilities Working Group Meeting... Protection Agency (EPA or Agency) is announcing the third in-person meeting of the Climate Ready Water Utilities (CRWU) Working Group of the National Drinking Water Advisory Council (NDWAC). The purpose of...

  11. 75 FR 35458 - National Drinking Water Advisory Council's Climate Ready Water Utilities Working Group Meeting...

    Science.gov (United States)

    2010-06-22

    ... AGENCY National Drinking Water Advisory Council's Climate Ready Water Utilities Working Group Meeting... Protection Agency (EPA or Agency) is announcing the fourth in-person meeting of the Climate Ready Water Utilities (CRWU) Working Group of the National Drinking Water Advisory Council (NDWAC). The purpose of...

  12. 75 FR 1380 - National Drinking Water Advisory Council's Climate Ready Water Utilities Working Group Meeting...

    Science.gov (United States)

    2010-01-11

    ... AGENCY National Drinking Water Advisory Council's Climate Ready Water Utilities Working Group Meeting... Agency (EPA or Agency) is announcing the second in-person meeting of the Climate Ready Water Utilities (CRWU) Working Group of the National Drinking Water Advisory Council (NDWAC). The purpose of...

  13. Analysis of Dissolved Organic Nutrients in the Interstitial Water of Natural Biofilms.

    Science.gov (United States)

    Tsuchiya, Yuki; Eda, Shima; Kiriyama, Chiho; Asada, Tomoya; Morisaki, Hisao

    2016-07-01

    In biofilms, the matrix of extracellular polymeric substances (EPSs) retains water in the interstitial region of the EPS. This interstitial water is the ambient environment for microorganisms in the biofilms. The nutrient condition in the interstitial water may affect microbial activity in the biofilms. In the present study, we measured the concentrations of dissolved organic nutrients, i.e., saccharides and proteins, contained in the interstitial water of biofilms formed on the stones. We also analyzed the molecular weight distribution, chemical species, and availability to bacteria of some saccharides in the interstitial water. Colorimetric assays showed that the concentrations of saccharides and proteins in the biofilm interstitial water were significantly higher (ca. 750 times) than those in the surrounding lake waters (p interstitial waters were mainly of low molecular-weight saccharides such as glucose and maltose, while proteins in the interstitial water were high molecular-weight proteins (over 7000 Da). Bacterial growth and production of EPS occurred simultaneously with the decrease in the low molecular-weight saccharide concentrations when a small portion of biofilm suspension was inoculated to the collected interstitial water, suggesting that the dissolved saccharides in the interstitial water support bacterial growth and formation of biofilms.

  14. 76 FR 72703 - Meeting of the National Drinking Water Advisory Council-Notice of Public Meeting

    Science.gov (United States)

    2011-11-25

    ... AGENCY Meeting of the National Drinking Water Advisory Council--Notice of Public Meeting AGENCY... meeting of the National Drinking Water Advisory Council (NDWAC or Council), established under the Safe Drinking Water Act. The Council will consider various issues associated with drinking water protection...

  15. In situ detection and characterization of potable water biofilms on materials by microscopic, spectroscopic and electrochemistry methods

    Energy Technology Data Exchange (ETDEWEB)

    Gamby, Jean [Universite Pierre et Marie Curie - Paris 6, CNRS-UPR 15, Laboratoire Interfaces et Systemes Electrochimiques, 4 Place Jussieu, Case Courrier 133, 75252 Paris Cedex 05 (France)], E-mail: jean.gamby@upmc.fr; Pailleret, Alain [Universite Pierre et Marie Curie - Paris 6, CNRS-UPR 15, Laboratoire Interfaces et Systemes Electrochimiques, 4 Place Jussieu, Case Courrier 133, 75252 Paris Cedex 05 (France); Clodic, Carol Boucher; Pradier, Claire-Marie [Universite Pierre et Marie Curie - Paris 6, CNRS-UMR 7609, Laboratoire de Reactivite de Surface, 4 Place Jussieu, Case Courrier 178, 75252 Paris Cedex 05 (France); Tribollet, Bernard [Universite Pierre et Marie Curie - Paris 6, CNRS-UPR 15, Laboratoire Interfaces et Systemes Electrochimiques, 4 Place Jussieu, Case Courrier 133, 75252 Paris Cedex 05 (France)

    2008-12-01

    We studied biofilm formation on stainless steel occurring in a drinking water distribution system which operated in parallel at 20 and 37 deg. C, in order to focus on the effect of temperature rather than on other operational and water quality parameters. A surface conditioning step was followed as a function of time on this material until adhesion of bacterial colonies by using microscopic methods: scanning electron microscopy (SEM) and atomic force microscopy (AFM); a spectroscopic method: polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS), and an electrochemical method: rotating disk electrode (RDE). Correlations between surface analysis, the duration of immersion of the sample and the influence of temperature have been identified clearly before bacterial adhesion. In cold water, these results showed an initial conditioning step of surface occurring during the first 8 days, with detection of superficial acidic functions grafted on surface, until adsorption of proteins. After 12 days, formation of independent bacteria microcolonies, reaching 2-3 {mu}m in length was observed. In tepid water, the first step was reduced to 2 days during which carbonates, acidic functions, and proteins were detected. After 90 days, the biofilm entered in a stable population state, which appeared as a bacteria rich film, including possibly Legionella. The spatial variation of the biofilm was limited as deduced from the thickness determination (about 4 {mu}m for 3-month period), using a RDE. The combination of these different techniques confirms successive steps for biofilm formation on stainless steel in a tap water. Then, we scrutinized the external near environment of bacteria including extracellular polymeric substances (EPS) and then further characterize the morphology of dominant bacteria (shape, size, flagellum) on gold substrate by AFM in air.

  16. Evidence of arsenic release promoted by disinfection by-products within drinking-water distribution systems.

    Science.gov (United States)

    Andra, Syam S; Makris, Konstantinos C; Botsaris, George; Charisiadis, Pantelis; Kalyvas, Harris; Costa, Costas N

    2014-02-15

    Changes in disinfectant type could trigger a cascade of reactions releasing pipe-anchored metals/metalloids into finished water. However, the effect of pre-formed disinfection by-products on the release of sorbed contaminants (arsenic-As in particular) from drinking water distribution system pipe scales remains unexplored. A bench-scale study using a factorial experimental design was performed to evaluate the independent and interaction effects of trihalomethanes (TTHM) and haloacetic acids (HAA) on arsenic (As) release from either scales-only or scale-biofilm conglomerates (SBC) both anchored on asbestos/cement pipe coupons. A model biofilm (Pseudomonas aeruginosa) was allowed to grow on select pipe coupons prior experimentation. Either TTHM or HAA individual dosing did not promote As release from either scales only or SBC, detecting water. In the case of scales-only coupons, the combination of the highest spike level of TTHM and HAA significantly (pdisinfected finished water in pipe networks remains to be investigated in the field.

  17. Microflora of drinking water distributed through decentralized supply systems (Tomsk)

    Science.gov (United States)

    Khvaschevskaya, A. A.; Nalivaiko, N. G.; Shestakova, A. V.

    2016-03-01

    The paper considers microbiological quality of waters from decentralized water supply systems in Tomsk. It has been proved that there are numerous microbial contaminants of different types. The authors claim that the water distributed through decentralized supply systems is not safe to drink without preliminary treatment.

  18. Condition Assessment for Drinking Water Transmission and Distribution Mains

    Science.gov (United States)

    This project seeks to improve the capability to characterize the condition of water infrastructure. The integrity of buried drinking water mains is critical, as it influences water quality, losses, pressure and cost. This research complements the U.S. Environmental Protection A...

  19. Discolouration in drinking water systems: a particular approach

    NARCIS (Netherlands)

    Vreeburg, J.H.G.

    2007-01-01

    The quality of drinking water in the Netherlands meets high standards as is annually reported by the Ministry of Housing, Spatial Planning and the Environment (VROM)(Versteegh and Dik, 2006). Also the water companies themselves report in the voluntary Benchmark that water quality is one of the least

  20. Biological instability in a chlorinated drinking water distribution network.

    Science.gov (United States)

    Nescerecka, Alina; Rubulis, Janis; Vital, Marius; Juhna, Talis; Hammes, Frederik

    2014-01-01

    The purpose of a drinking water distribution system is to deliver drinking water to the consumer, preferably with the same quality as when it left the treatment plant. In this context, the maintenance of good microbiological quality is often referred to as biological stability, and the addition of sufficient chlorine residuals is regarded as one way to achieve this. The full-scale drinking water distribution system of Riga (Latvia) was investigated with respect to biological stability in chlorinated drinking water. Flow cytometric (FCM) intact cell concentrations, intracellular adenosine tri-phosphate (ATP), heterotrophic plate counts and residual chlorine measurements were performed to evaluate the drinking water quality and stability at 49 sampling points throughout the distribution network. Cell viability methods were compared and the importance of extracellular ATP measurements was examined as well. FCM intact cell concentrations varied from 5×10(3) cells mL(-1) to 4.66×10(5) cells mL(-1) in the network. While this parameter did not exceed 2.1×10(4) cells mL(-1) in the effluent from any water treatment plant, 50% of all the network samples contained more than 1.06×10(5) cells mL(-1). This indisputably demonstrates biological instability in this particular drinking water distribution system, which was ascribed to a loss of disinfectant residuals and concomitant bacterial growth. The study highlights the potential of using cultivation-independent methods for the assessment of chlorinated water samples. In addition, it underlines the complexity of full-scale drinking water distribution systems, and the resulting challenges to establish the causes of biological instability.

  1. Biological instability in a chlorinated drinking water distribution network.

    Directory of Open Access Journals (Sweden)

    Alina Nescerecka

    Full Text Available The purpose of a drinking water distribution system is to deliver drinking water to the consumer, preferably with the same quality as when it left the treatment plant. In this context, the maintenance of good microbiological quality is often referred to as biological stability, and the addition of sufficient chlorine residuals is regarded as one way to achieve this. The full-scale drinking water distribution system of Riga (Latvia was investigated with respect to biological stability in chlorinated drinking water. Flow cytometric (FCM intact cell concentrations, intracellular adenosine tri-phosphate (ATP, heterotrophic plate counts and residual chlorine measurements were performed to evaluate the drinking water quality and stability at 49 sampling points throughout the distribution network. Cell viability methods were compared and the importance of extracellular ATP measurements was examined as well. FCM intact cell concentrations varied from 5×10(3 cells mL(-1 to 4.66×10(5 cells mL(-1 in the network. While this parameter did not exceed 2.1×10(4 cells mL(-1 in the effluent from any water treatment plant, 50% of all the network samples contained more than 1.06×10(5 cells mL(-1. This indisputably demonstrates biological instability in this particular drinking water distribution system, which was ascribed to a loss of disinfectant residuals and concomitant bacterial growth. The study highlights the potential of using cultivation-independent methods for the assessment of chlorinated water samples. In addition, it underlines the complexity of full-scale drinking water distribution systems, and the resulting challenges to establish the causes of biological instability.

  2. Refractive Errors in Northern China Between the Residents with Drinking Water Containing Excessive Fluorine and Normal Drinking Water.

    Science.gov (United States)

    Bin, Ge; Liu, Haifeng; Zhao, Chunyuan; Zhou, Guangkai; Ding, Xuchen; Zhang, Na; Xu, Yongfang; Qi, Yanhua

    2016-10-01

    The purpose of this study was to evaluate the refractive errors and the demographic associations between drinking water with excessive fluoride and normal drinking water among residents in Northern China. Of the 1843 residents, 1415 (aged ≥40 years) were divided into drinking-water-excessive fluoride (DWEF) group (>1.20 mg/L) and control group (≤1.20 mg/L) on the basis of the fluoride concentrations in drinking water. Of the 221 subjects in the DWEF group, with 1.47 ± 0.25 mg/L (fluoride concentrations in drinking water), the prevalence rates of myopia, hyperopia, and astigmatism were 38.5 % (95 % confidence interval [CI] = 32.1-45.3), 19.9 % (95 % CI = 15-26), and 41.6 % (95 % CI = 35.1-48.4), respectively. Of the 1194 subjects in the control group with 0.20 ± 0.18 mg/L, the prevalence of myopia, hyperopia, and astigmatism were 31.5 % (95 % CI = 28.9-34.2), 27.6 % (95 % CI = 25.1-30.3), and 45.6 % (95 % CI = 42.8-48.5), respectively. A statistically significant difference was not observed in the association of spherical equivalent and fluoride concentrations in drinking water (P = 0.84 > 0.05). This report provides the data of the refractive state of the residents consuming drinking water with excess amounts of fluoride in northern China. The refractive errors did not result from ingestion of mild excess amounts of fluoride in the drinking water.

  3. Chemical quality and regulatory compliance of drinking water in Iceland.

    Science.gov (United States)

    Gunnarsdottir, Maria J; Gardarsson, Sigurdur M; Jonsson, Gunnar St; Bartram, Jamie

    2016-11-01

    Assuring sufficient quality of drinking water is of great importance for public wellbeing and prosperity. Nations have developed regulatory system with the aim of providing drinking water of sufficient quality and to minimize the risk of contamination of the water supply in the first place. In this study the chemical quality of Icelandic drinking water was evaluated by systematically analyzing results from audit monitoring where 53 parameters were assessed for 345 samples from 79 aquifers, serving 74 water supply systems. Compliance to the Icelandic Drinking Water Regulation (IDWR) was evaluated with regard to parametric values, minimum requirement of sampling, and limit of detection. Water quality compliance was divided according to health-related chemicals and indicators, and analyzed according to size. Samples from few individual locations were benchmarked against natural background levels (NBLs) in order to identify potential pollution sources. The results show that drinking compliance was 99.97% in health-related chemicals and 99.44% in indicator parameters indicating that Icelandic groundwater abstracted for drinking water supply is generally of high quality with no expected health risks. In 10 water supply systems, of the 74 tested, there was an indication of anthropogenic chemical pollution, either at the source or in the network, and in another 6 water supplies there was a need to improve the water intake to prevent surface water intrusion. Benchmarking against the NBLs proved to be useful in tracing potential pollution sources, providing a useful tool for identifying pollution at an early stage. Copyright © 2016 Elsevier GmbH. All rights reserved.

  4. Comparison of Particle-Associated Bacteria from a Drinking Water Treatment Plant and Distribution Reservoirs with Different Water Sources

    Science.gov (United States)

    Liu, G.; Ling, F. Q.; van der Mark, E. J.; Zhang, X. D.; Knezev, A.; Verberk, J. Q. J. C.; van der Meer, W. G. J.; Medema, G. J.; Liu, W. T.; van Dijk, J. C.

    2016-02-01

    This study assessed the characteristics of and changes in the suspended particles and the associated bacteria in an unchlorinated drinking water distribution system and its reservoirs with different water sources. The results show that particle-associated bacteria (PAB) were present at a level of 0.8-4.5 × 103 cells ml-1 with a biological activity of 0.01-0.04 ng l-1 ATP. Different PAB communities in the waters produced from different sources were revealed by a 16S rRNA-based pyrosequencing analysis. The quantified biomass underestimation due to the multiple cells attached per particle was ≥ 85%. The distribution of the biologically stable water increased the number of cells per particle (from 48 to 90) but had minor effects on the PAB community. Significant changes were observed at the mixing reservoir. Our results show the characteristics of and changes in suspended PAB during distribution, and highlight the significance of suspended PAB in the distribution system, because suspended PAB can lead to a considerable underestimation of biomass, and because they exist as biofilm, which has a greater mobility than pipe-wall biofilm and therefore presents a greater risk, given the higher probability that it will reach the customers’ taps and be ingested.

  5. Comparison of Particle-Associated Bacteria from a Drinking Water Treatment Plant and Distribution Reservoirs with Different Water Sources.

    Science.gov (United States)

    Liu, G; Ling, F Q; van der Mark, E J; Zhang, X D; Knezev, A; Verberk, J Q J C; van der Meer, W G J; Medema, G J; Liu, W T; van Dijk, J C

    2016-02-02

    This study assessed the characteristics of and changes in the suspended particles and the associated bacteria in an unchlorinated drinking water distribution system and its reservoirs with different water sources. The results show that particle-associated bacteria (PAB) were present at a level of 0.8-4.5 × 10(3) cells ml(-1) with a biological activity of 0.01-0.04 ng l(-1) ATP. Different PAB communities in the waters produced from different sources were revealed by a 16S rRNA-based pyrosequencing analysis. The quantified biomass underestimation due to the multiple cells attached per particle was ≥ 85%. The distribution of the biologically stable water increased the number of cells per particle (from 48 to 90) but had minor effects on the PAB community. Significant changes were observed at the mixing reservoir. Our results show the characteristics of and changes in suspended PAB during distribution, and highlight the significance of suspended PAB in the distribution system, because suspended PAB can lead to a considerable underestimation of biomass, and because they exist as biofilm, which has a greater mobility than pipe-wall biofilm and therefore presents a greater risk, given the higher probability that it will reach the customers' taps and be ingested.

  6. Microbiological Contamination of Drinking Water Associated with Subsequent Child Diarrhea.

    Science.gov (United States)

    Luby, Stephen P; Halder, Amal K; Huda, Tarique Md; Unicomb, Leanne; Islam, M Sirajul; Arnold, Benjamin F; Johnston, Richard B

    2015-11-01

    We used a prospective, longitudinal cohort enrolled as part of a program evaluation to assess the relationship between drinking water microbiological quality and child diarrhea. We included 50 villages across rural Bangladesh. Within each village field-workers enrolled a systematic random sample of 10 households with a child under the age of 3 years. Community monitors visited households monthly and recorded whether children under the age of 5 years had diarrhea in the preceding 2 days. Every 3 months, a research assistant visited the household and requested a water sample from the source or container used to provide drinking water to the child. Laboratory technicians measured the concentration of Escherichia coli in the water samples using membrane filtration. Of drinking water samples, 59% (2,273/3,833) were contaminated with E. coli. Of 12,192 monthly follow-up visits over 2 years, mothers reported that their child had diarrhea in the preceding 2 days in 1,156 (9.5%) visits. In a multivariable general linear model, the log10 of E. coli contamination of the preceding drinking water sample was associated with an increased prevalence of child diarrhea (prevalence ratio = 1.14, 95% CI = 1.05, 1.23). These data provide further evidence of the health benefits of improved microbiological quality of drinking water. © The American Society of Tropical Medicine and Hygiene.

  7. Artificial sweetener sucralose in U.S. drinking water systems.

    Science.gov (United States)

    Mawhinney, Douglas B; Young, Robert B; Vanderford, Brett J; Borch, Thomas; Snyder, Shane A

    2011-10-15

    The artificial sweetener sucralose has recently been shown to be a widespread of contaminant of wastewater, surface water, and groundwater. In order to understand its occurrence in drinking water systems, water samples from 19 United States (U.S.) drinking water treatment plants (DWTPs) serving more than 28 million people were analyzed for sucralose using liquid chromatography tandem mass spectrometry (LC-MS/MS). Sucralose was found to be present in source water of 15 out of 19 DWTPs (47-2900 ng/L), finished water of 13 out of 17 DWTPs (49-2400 ng/L) and distribution system water of 8 out of the 12 DWTPs (48-2400 ng/L) tested. Sucralose was only found to be present in source waters with known wastewater influence and/or recreational usage, and displayed low removal (12% average) in the DWTPs where finished water was sampled. Further, in the subset of DWTPs with distribution system water sampled, the compound was found to persist regardless of the presence of residual chlorine or chloramines. In order to understand intra-DWTP consistency, sucralose was monitored at one drinking water treatment plant over an 11 month period from March 2010 through January 2011, and averaged 440 ng/L in the source water and 350 ng/L in the finished water. The results of this study confirm that sucralose will function well as an indicator compound for anthropogenic influence on source, finished drinking and distribution system (i.e., tap) water, as well as an indicator compound for the presence of other recalcitrant compounds in finished drinking water in the U.S.

  8. Drinking Water Sources with Surface Intakes from LDHH source data, Geographic NAD83, LOSCO (1999) [drinking_water_surface_intakes_LDHH_1999

    Data.gov (United States)

    Louisiana Geographic Information Center — This is a point dataset for 87 public drinking water sources with surface intakes. It was derived from a larger statewide general drinking water source dataset...

  9. Postexercise rehydration: potassium-rich drinks versus water and a sports drink.

    Science.gov (United States)

    Pérez-Idárraga, Alexandra; Aragón-Vargas, Luis Fernando

    2014-10-01

    Fluid retention, thirst quenching, tolerance, and palatability of different drinks were assessed. On 4 different days, 12 healthy, physically active volunteers (24.4 ± 3.2 years old, 74.75 ± 11.36 kg body mass (mean ± S.D)), were dehydrated to 2.10% ± 0.24% body mass by exercising in an environmental chamber (32.0 ± 0.4 °C dry bulb, 53.8 ± 5.2% relative humidity). Each day they drank 1 of 4 beverages in random order: fresh coconut water (FCW), bottled water (W), sports drink (SD), or potassium-rich drink (NEW); volume was 120% of weight loss. Urine was collected and perceptions self-reported for 3 h. Urine output was higher (p drink (p > 0.05). Fluid retention was higher for SD than W (68.2% ± 13.0% vs. 51.3% ± 12.6%, p = 0.013), but not for FCW and NEW (62.5% ± 15.4% and 65.9% ± 15.4%, p > 0.05). All beverages were palatable and well tolerated; none maintained a positive net fluid balance after 3 h, but deficit was greater in W versus SD (p = 0.001). FCW scored higher for sweetness (p = 0.03). Thirst increased immediately after exercise but returned to baseline after drinking a small volume (p drink with sodium.

  10. The role of advanced oxidation processes in drinking water treatment

    OpenAIRE

    Philippe, Karine K.

    2010-01-01

    Removal of natural organic matter (NOM) is an ever growing challenge for water utilities as many surface waters used for drinking water in the UK exhibit increasing organics levels and it is well known that these organics can lead to problems such as water colouration, unpleasant odour and taste, bacterial growth and disinfection by-products (DBPs) formation. NOM is traditionally removed by coagulation, however in the case of hydrophilic organic matter rich waters the performances of these pr...

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

    Science.gov (United States)

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

    2011-10-01

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

  12. Fluoride and bacterial content of bottled drinking water versus municipal tap water

    Directory of Open Access Journals (Sweden)

    Mythri H

    2010-01-01

    Full Text Available Background: Water is a divine gift. People quench their thirst without questioning the source of water. But, apprehension about contaminants in municipal water supplies along with increased fear of fluorosis made bottled drinking water as one of the important tradable commodities. Objectives: The objectives of the study were to determine and compare the fluoride and bacterial contents of commercially available bottled drinking water and municipal tap water in Davangere city, Karnataka. Materials and Methods: Fifty samples of 10 categories of bottled drinking water with different batch numbers were purchased and municipal water from different sources were collected. Fluoride levels were determined by an ion-selective electrode. Water was cultured quantitatively and levels of bacteria were calculated as colony-forming units (CFUs per milliliter. Results: Descriptive analysis of water samples for fluoride concentration was in the range of 0.07-0.33 for bottled drinking water, Bisleri showing the highest of 0.33. A comparison of the mean values of microbial count for bottled drinking water with that of municipal tap water showed no statistically significant difference, but was more than the standard levels along with the presence of fungus and maggots. Conclusion: The fluoride concentration was below the optimal level for both municipal tap water and bottled drinking water. CFUs were more than the recommended level in both municipal tap water and bottled drinking water.

  13. Drinking Water Denitrification using Autotrophic Denitrifying Bacteria in a Fluidized Bed Bioreactor 

    Directory of Open Access Journals (Sweden)

    Abdolmotaleb Seid-mohammadi

    2013-02-01

    Full Text Available Background and Objectives: Contamination of drinking water sources with nitrate may cause adverse effects on human health. Due to operational and maintenance problems of physicochemical nitrate removal processes, using biological denitrification processes have been performed. The aim of this study is to evaluate nitrate removal efficiency from drinking water using autotrophic denitrifying bacteria immobilized on sulfur impregnated activated carbon in a fluidized bed bioreactor. Materials and Methods: After impregnating activated carbon by sulfur as a microorganism carriers and enrichment and inoculation of denitrifying bacteria, a laboratory-scale fluidized bed bioreactor was operated. Nitrate removal efficiency, nitrite, turbidity, hardness and TOC in the effluent were examined during the whole experiment under various conditions including constant influent nitrate concentration as 90 mg NO3--N/l corresponding to different HRT ranging from 5.53 to 1.5 hr. Results: We found that  the denitrification rates was depended on the hydraulic retention time and the nitrate removal efficiency was up to 98%  and nitrite concentration was lower than 1mg/l at optimum HRT=2.4 hr respectively. Moreover, there was no difference in hardness between influent and effluent due to supplying sodium bicarbonate as carbon source for denitrifying bacteria.  However pH, TOC, hardness, and turbidity of the effluent met the W.H.O guidelines for drinking water.  Conclusion: This study demonstrated that an innovative carrier as sulfur impregnated activated carbon could be used as both the biofilm carrier and energy source for treating nitrate contaminated drinking water in the lab-scale fluidized bed bioreactor.

  14. Drinking-Water Standards and Regulations. Volume 2. Manual for 1982-88

    Energy Technology Data Exchange (ETDEWEB)

    Wang, L.K.; Wang, M.H.S.

    1988-04-10

    The following 11 important documents are compiled for Drinking Water Standards and Regulations: (1) U.S. Environmental Agency Water Programs, National Interim Primary Drinking Water Regulations; (2) New Jersey Safe Drinking Water Act; (3) Summary of New Jersey Drinking Water Standards; (4) U.S. Environmental Protection Agency Safe Drinking Water Act of 1986 Amendments; (5) U.S. Environmental Protection Agency National Primary Drinking Water Standards; (6) Canadian National Health and Welfare Drinking Water Quality Guidelines--Maximum Acceptable Concentrations; (7) U.S. Environmental Protection Agency, National Primary Drinking Water Regulations, Filtration and Disinfection Turbidity, Giardia Lamblia, Viruses, Legionella, and Heterotrophic Bacteria; (8) Public Water Supply Manual--Guide to the Safe Drinking Water Program; (9) Public Water Supply Manual--Emergency Response; (10) U.S. EPA Approved Krofta Chemicals; (11) NY-DOH Approved Krofta Chemicals.

  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 Fe2O3 particles in it, although it is saturated faster than radium. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Trihalomethanes in drinking water and the risk of death from kidney cancer: does hardness in drinking water matter?

    Science.gov (United States)

    Liao, Yen-Hsiung; Chen, Chih-Cheng; Chang, Chih-Ching; Peng, Chiung-Yu; Chiu, Hui-Fen; Wu, Trong-Neng; Yang, Chun-Yuh

    2012-01-01

    The objectives of this study were to (1) examine the relationship between total trihalomethanes (TTHM) levels in public water supplies and risk of development of kidney cancer and (2) determine whether hardness levels in drinking water modify the effects of TTHM on risk of kidney cancer induction. A matched case-control study was used to investigate the relationship between the risk of death attributed to kidney cancer and exposure to TTHM in drinking water in 53 municipalities in Taiwan. All kidney cancer deaths in the 53 municipalities from 1998 through 2007 were obtained. Controls were deaths from other causes and were pair-matched to the cancer cases by gender, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each cancer case. Data on TTHM levels and levels of hardness in drinking water were also collected. The municipality of residence for cancer cases and controls was presumed to be the source of the subject's TTHM and hardness exposure via drinking water. Relative to individuals whose TTHM exposure level was water with a TTHM exposure ≥4.9 ppb. However, evidence of an interaction was noted between the use of soft water and drinking water TTHM concentrations. Increased knowledge of the interaction between hardness and TTHM levels in reducing risk of kidney cancer development will aid in public policy decision and establishing standards to prevent disease occurrence.

  17. Nitrates in drinking water and the risk of death from brain cancer: does hardness in drinking water matter?

    Science.gov (United States)

    Ho, Chi-Kung; Yang, Ya-Hui; Yang, Chun-Yuh

    2011-01-01

    The objectives of this study were to (1) examine the relationship between nitrate levels in public water supplies and risk of death from brain cancer and (2) determine whether calcium (Ca) and magnesium (Mg) levels in drinking water might modify the influence of nitrates on development of brain cancer. A matched cancer case-control study was used to investigate the relationship between the risk of death from brain cancer and exposure to nitrates in drinking water in Taiwan. All brain cancer deaths of Taiwan residents from 2003 through 2008 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to cancer cases by gender, year of birth, and year of death. Information on the levels of nitrate-nitrogen (NO₃-N), Ca, and Mg in drinking water was obtained from Taiwan Water Supply Corporation (TWSC). The municipality of residence for cancer cases and controls was presumed to be the source of the subject's NO₃-N, Ca, and Mg exposure via drinking water. Relative to individuals whose NO₃-N exposure level was water with a NO₃-N exposure ≥ 0.38 ppm. No marked effect modification was observed due to Ca and Mg intake via drinking water on brain cancer occurrence.

  18. Contribution of drinking water to dietary requirements of essential metals.

    Science.gov (United States)

    Deveau, Michelle

    2010-01-01

    Drinking water can be a source of essential metals, but only one study published thus far has compared the intake of essential metals in drinking water to dietary reference intakes. This assessment compares the ingestion of chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), selenium (Se), and zinc (Zn) from drinking water at the maximum concentrations that should be found in water, or at concentrations that are potentially more likely to be found in Canadian water, to the recommended dietary allowance or adequate intake values established by the Institute of Medicine. At guideline limits, water provides sufficient Cr and Cu to meet nutritional requirements, and Mn and Zn levels are sufficient for some age categories to meet nutritional requirements. At concentrations that are more likely to be found in Canadian water, adequate intakes for Cr and Mn may be met by water alone for bottle-fed infants, and water was estimated to provide 23-66% of daily Cu requirements. Drinking water might become a significant source of some essential metals in individuals whose diets are low in these metals, especially in the case of Cu.

  19. The 1991 Lead/Copper Drinking Water Rule and the 1995 Decision Not to Revise the Arsenic Drinking Water Rule: Two Case Studies in EPA's Use of Science

    OpenAIRE

    Powell, Mark

    1996-01-01

    This paper discusses EPA's acquisition and use of science in two decisions under the Safe Drinking Water Act: the 1991 revision of the lead drinking water regulations and the 1995 decision to pursue additional research instead of revising the arsenic in drinking water standard. In the first case, a committed band of policy entrepreneurs within EPA mobilized and supplemented scientific information which had accumulated in the agency's air program to force lead in drinking water up the agency's...

  20. Drinking and Cleaning Water Use in a Dairy Cow Barn

    Directory of Open Access Journals (Sweden)

    Michael Krauß

    2016-07-01

    Full Text Available Water is used in dairy farming for producing feed, watering the animals, and cleaning and disinfecting barns and equipment. The objective of this study was to investigate the drinking and cleaning water use in a dairy cow barn. The water use was measured on a well-managed commercial dairy farm in North-East Germany. Thirty-eight water meters were installed in a barn with 176 cows and two milking systems (an automatic milking system and a herringbone parlour. Their counts were logged hourly over 806 days. On average, the cows in the automatic milking system used 91.1 (SD 14.3 L drinking water per cow per day, while those in the herringbone parlour used 54.4 (SD 5.3 L per cow per day. The cows drink most of the water during the hours of (natural and artificial light in the barn. Previously published regression functions of drinking water intake of the cows were reviewed and a new regression function based on the ambient temperature and the milk yield was developed (drinking water intake (L per cow per day = −27.937 + 0.49 × mean temperature + 3.15 × milk yield (R2 = 0.67. The cleaning water demand had a mean of 28.6 (SD 14.8 L per cow per day in the automatic milking system, and a mean of 33.8 (SD 14.1 L per cow per day in the herringbone parlour. These findings show that the total technical water use in the barn makes only a minor contribution to water use in dairy farming compared with the water use for feed production.

  1. Are Endocrine Disrupting Compounds a Health Risk in Drinking Water?

    Directory of Open Access Journals (Sweden)

    Ian R. Falconer

    2006-06-01

    Full Text Available There has been a great deal of international discussion on the nature and relevance of endocrine disrupting compounds in the environment. Changes in reproductive organs of fish and mollusks have been demonstrated in rivers downstream of sewage discharges in Europe and in North America, which have been attributed to estrogenic compounds in the effluent. The anatomical and physiological changes in the fauna are illustrated by feminization of male gonads. The compounds of greatest hormonal activity in sewage effluent are the natural estrogens 17β-estradiol, estrone, estriol and the synthetic estrogen ethinylestradiol. Androgens are also widely present in wastewaters. Investigations of anthropogenic chemical contaminants in freshwaters and wastewaters have shown a wide variety of organic compounds, many of which have low levels of estrogenic activity. In many highly populated countries the drinking water is sourced from the same rivers and lakes that are the recipients of sewage and industrial discharge. The River Thames which flows through London, England, has overall passed through drinking water and sewage discharge 5 times from source to mouth of the river. Under these types of circumstance, any accumulation of endocrine disrupting compounds from sewage or industry potentially affects the quality of drinking water. Neither basic wastewater treatment nor basic drinking water treatment will eliminate the estrogens, androgens or detergent breakdown products from water, due to the chemical stability of the structures. Hence a potential risk to health exists; however present data indicate that estrogenic contamination of drinking water is very unlikely to result in physiologically detectable effects in consumers. Pesticide, detergent and industrial contamination remain issues of concern. As a result of this concern, increased attention is being given to enhanced wastewater treatment in locations where he effluent is directly or indirectly in

  2. Microbiological quality of carbonated drinking water produced with in-home carbonation systems.

    Science.gov (United States)

    Kohnen, Wolfgang; Teske-Keiser, Susanne; Meyer, Heinz-Georg; Loos, Anja H; Pietsch, Michael; Jansen, Bernd

    2005-01-01

    The microbiological quality of carbonated water produced with tap water in commercial in-home carbonation systems was determined, the results being discussed in the context of the microbiological quality of the tap water used, the properties of the drink makers, and the procedures of preparation and washing of various parts of the appliance. The last-mentioned data were received from each participant of the study by questionnaire. Escherichia coli, coliforms, fecal streptococci and spore-forming sulphite-reducing anaerobes were used as indicators for the hygienic quality of the water. Tap-water samples were collected according to the usual procedure when filling the carbonating bottle, i.e., without previous flushing and disinfection of the faucet. In 12% of tap-water samples, coliforms could be detected. On the other hand, in 20 of 52 carbonated waters (39%), coliforms as indicators of water pollution were found. By means of fecal streptococci and Pseudomonas aeruginosa, it was possible to establish additional contamination not involving E. coli or coliforms alone. Analysis revealed that, in addition to contaminated tap water, a bacterial biofilm on the inner surface of the re-usable bottles had a predominant influence on the microbiological quality of the carbonated water.

  3. Free-living amoebae, Legionella and Mycobacterium in tap water supplied by a municipal drinking water utility in the USA.

    Science.gov (United States)

    Marciano-Cabral, Francine; Jamerson, Melissa; Kaneshiro, Edna S

    2010-03-01

    Legionella and Mycobacterium can proliferate within free-living amoebae (FLA) where they are protected from disinfectants at concentrations that can kill bacteria but not protozoa. Despite effective treatment of drinking water, microbes can enter water utility distribution systems (DS) and hence the plumbing within building premises. Additionally, biofilm formation may account for the persistence of microbes in the DS. In the present study a domestic water tap in north-central United States (USA) was sampled in March and September 2007 and analysed for FLA, Legionella and Mycobacterium. Identification of organisms was determined by growth on specific culture media, light and electron microscopy, and amplification of DNA probes specific for each organism. In both the spring and fall samples, amoebae, Legionella and Mycobacterium were detected. However, Acanthamoeba was prominent in the spring sample whereas Vahlkampfia and Naegleria were the amoebae detected in the autumn. Bacterial proliferation in laboratory cultures was noticeably enhanced in the presence of amoebae and biofilms rapidly formed in mixed amoebae and bacteria cultures. It is hypothesized that temperature affected the dynamics of FLA species population structure within the DS and that pathogenic bacteria that proliferate within FLA, which are themselves opportunistic pathogens, pose dual public health risks.

  4. Study of biofilm influenced corrosion on cast iron pipes in reclaimed water

    Science.gov (United States)

    Zhang, Haiya; Tian, Yimei; Wan, Jianmei; Zhao, Peng

    2015-12-01

    Biofilm influenced corrosion on cast iron pipes in reclaimed water was systemically studied using the weight loss method and electrochemical impedance spectroscopy (EIS). The results demonstrated that compared to sterile water, the existence of the biofilm in reclaimed water promoted the corrosion process significantly. The characteristics of biofilm on cast iron coupons were examined by the surface profiler, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The bacterial counts in the biofilm were determined using the standard plate count method and the most probable number (MPN). The results demonstrated that the corrosion process was influenced by the settled bacteria, EPS, and corrosion products in the biofilm comprehensively. But, the corrosion mechanisms were different with respect to time and could be divided into three stages in our study. Furthermore, several corresponding corrosion mechanisms were proposed for different immersion times.

  5. Corona discharges with water electrospray for Escherichia coli biofilm eradication on a surface.

    Science.gov (United States)

    Kovalova, Zuzana; Leroy, Magali; Kirkpatrick, Michael J; Odic, Emmanuel; Machala, Zdenko

    2016-12-01

    Low-temperature plasma (cold), a new method for the decontamination of surfaces, can be an advantageous alternative to the traditional chemical methods, autoclave or dry heat. Positive and negative corona discharges in air were tested for the eradication of 48-h Escherichia coli biofilms grown on glass slides. The biofilms were treated by cold corona discharge plasma for various exposure times. Water electrospray from the high voltage electrode was applied in some experiments. Thermostatic cultivation of the biofilm, and confocal laser scanning microscopy (CLSM) of the biofilm stained with fluorescent dyes were used for biocidal efficiency quantification. Up to 5 log10 reduction of bacterial concentration in the biofilm was measured by thermostatic cultivation after exposure to both corona discharges for 15min. This decontamination efficiency was significantly enhanced by simultaneous water electrospray through the plasma. CLSM showed that the live/dead ratio after treatment remained almost constant inside the biofilm; only cells on the top layers of the biofilm were affected. DAPI fluorescence showed that biofilm thickness was reduced by about 1/3 upon exposure to the corona discharges with electrospray for 15min. The biofilm biomass loss by about 2/3 was confirmed by crystal violet assay.

  6. Hydraulic modelling of drinking water treatment plant operations

    Directory of Open Access Journals (Sweden)

    K. J. Borger

    2008-10-01

    Full Text Available For a drinking water treatment plant simulation, water quality models, a hydraulic model, a process-control model, an object model, data management, training and decision-support features and a graphic user interface have been integrated. The integration of a hydraulic model in the simulator is necessary to correctly determine the division of flows over the plant's lanes and, thus, the flow through the individual treatment units, based on valve positions and pump speeds. The flow through a unit is one of the most important parameters in terms of a unit's effectiveness. In the present paper, a new EPAnet library is presented with the typical hydraulic elements for drinking water treatment processes. Using this library, a hydraulic model was set up and validated for the drinking water treatment plant Harderbroek.

  7. Drinking water safety and the development of purification technology

    Institute of Scientific and Technical Information of China (English)

    Li Guibai

    2012-01-01

    This paper briefly introduced the evolution of purification technology for drinking water over time. After description of the 1st generation processes in the beginning of the 20th century -- conventional processes and the 2nd generation processes in 1970s -- advanced treatment processes, a tertiary processes -- UF (ultrafiltration) based on integrated processes was proposed. Moreover, reaction measures (dosing variety of regents for different contaminants) for urban source water emergencies.were illustrated in brief. A new technology of KMnO4 and potassium permanganate composite (PPC) for drinking water purification which was developed by Harbin Institute of Technology (HIT) was concisely introduced.

  8. Activity of ozonated water and ozone against Staphylococcus aureus and Pseudomonas aeruginosa biofilms

    Science.gov (United States)

    Bialoszewski, Dariusz; Pietruczuk-Padzik, Anna; Kalicinska, Agnieszka; Bocian, Ewa; Czajkowska, Magdalena; Bukowska, Bozena; Tyski, Stefan

    2011-01-01

    Summary Background The known bactericidal properties of ozone have not been checked in relation to its action on bacterial biofilms. This is especially true of ozonated fluids. The aim of this study was to investigate the bactericidal activity of ozonated water and that of a mixture of ozone and oxygen against biofilms. Material/Methods Eighteen clinical strains of Staphylococcus aureus and Pseudomonas aeruginosa exhibiting various levels of antibiotic sensitivity were investigated. Bacteria were cultured in biofilm form on polystyrene titration plates for periods of 2 to 72 hours. The biofilms formed in this way were exposed to in statu nascendi ozonated water produced in a prototype device that had been tested in clinical conditions, or to a mixture of oxygen and ozone generated in the same device. Live cells in the biofilm were stained with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) bromide solution. The degree of reduction of viable bacteria following ozone exposure was determined. Results Ozonated water was found to be an effective bactericidal agent against biofilms after as little as 30 seconds of exposure, while the bactericidal activity of the ozone-oxygen solution was much lower. Prolongation of the duration of biofilm exposure to the gaseous disinfectant to 40 minutes led to a reduction in the viable cell count, which nevertheless remained high. Conclusions Unlike the ozone-oxygen mixture, ozonated water effectively destroys bacterial biofilms in vitro. PMID:22037737

  9. Nitrate intake from drinking water on Tenerife island (Spain).

    Science.gov (United States)

    Caballero Mesa, J M; Rubio Armendáriz, C; Hardisson de la Torre, A

    2003-01-20

    Although meat and vegetable products contain higher concentrations of nitrate, drinking water is the fastest and most direct form of nitrate consumption by the population. It becomes contaminated with nitrates when sea water infiltrates fresh water aquifers and when rain and irrigation water wash through soils that have been excessively treated with nitrated fertilizers. Nitrates are of great toxicological interest as they are involved in the origin of nitrites and nitrosamines and the development of metahaemoglobinaemia in infants. The objective of this study was to determine the quantities of NO(3)(-) in the water supply of each of the Island's municipalities and in the leading brands of bottled waters consumed by the population of Tenerife. This parameter is necessary for the determination of Acceptable Daily Intake (A.D.I.) of nitrates from drinking water. With one unremarkable exception, the nitrate levels found in the water analyzed were optimum for human consumption and amply complied with current European Legislation.

  10. Laboratory investigation of drinking water sources of Kangra, Himachal Pradesh.

    Science.gov (United States)

    Thakur, S D; Panda, A K

    2012-06-01

    A total of 70 drinking water sources including piped water supply (n = 36), ground water sources (n = 24, hand pumps and bore wells) and natural water sources (n = 10, springs/step-wells) from various parts of district Kangra, Himachal Pradesh were investigated for their suitability for drinking purpose by presumptive coliform test. Three samples were collected from each source during different parts of the year. Piped water sources (91.7%) were most contaminated followed by natural water sources (90%) and ground water sources (62.5%). 70.5% of the total water samples (n = 210) were positive for coliforms. All the three samples from 8.3% (n = 3), 37.5% (n = 9) and 10% (n = 1) piped water, ground water and natural sources respectively, were negative for coliform organisms. A variety of organisms including Proteus, Klebsiella, Citrobacter, Escherichia coli (E. coli), Pasteurella, Enterobacter and Serratia liquefaciens were isolated from water samples positive for coliforms in presumptive coliform test. Thermo-tolerant coliform organisms; Escherichia coli, Citrobacter, Klebsiella and Enterobacter were 71.2% (n = 52) of the total bacterial isolations. These findings suggest absence of adequate treatment and disinfection of the water sources supplying drinking water in district Kangra.

  11. Health risks due to radon in drinking water

    Science.gov (United States)

    Hopke, P.K.; Borak, T.B.; Doull, J.; Cleaver, J.E.; Eckerman, K.F.; Gundersen, L.C.S.; Harley, N.H.; Hess, C.T.; Kinner, N.E.; Kopecky, K.J.; Mckone, T.E.; Sextro, R.G.; Simon, S.L.

    2000-01-01

    Following more than a decade of scientific debate about the setting of a standard for 222Rn in drinking water, Congress established a timetable for the promulgation of a standard in the 1996 Amendments to the Safe Drinking Water Act. As a result of those Amendments, the EPA contracted with the National Academy of Sciences to undertake a risk assessment for exposure to radon in drinking water. In addition, the resulting committee was asked to address several other scientific issues including the national average ambient 222Rn concentration and the increment of 222Rn to the indoor- air concentration arising from the use of drinking water in a home. A new dosimetric analysis of the cancer risk to the stomach from ingestion was performed. The recently reported risk estimates developed by the BEIR VI Committee for inhalation of radon decay products were adopted. Because the 1996 Amendments permit states to develop programs in which mitigation of air- producing health-risk reductions equivalent to that which would be achieved by treating the drinking water, the scientific issues involved in such 'multimedia mitigation programs' were explored.

  12. Occurrence, Monitoring and Treatment of Cyanobacterial Toxins in Drinking Water

    Science.gov (United States)

    In the summer of 2014 a number of drinking water treatment plants (DWTPs) on Lake Erie supplied water samples on a monthly basis for analysis. Chlorophyll-a measurements, LC/MS/MS and ELISA techniques specific to microcystins were employed to measure potential harmful algal bloom...

  13. Effect of the Distribution System on Drinking Water Quality

    Directory of Open Access Journals (Sweden)

    A. Grünwald

    2001-01-01

    Full Text Available The overall objective of this paper is to characterise the main aspects of water quality deterioration in a distribution system. The effect of residence time on chlorine uptake and the formation and evolution of disinfection by-products in distributed drinking water are discussed.

  14. physico-chemical and bacteriological analyses of drinking water in ...

    African Journals Online (AJOL)

    2, July, 2012, pp. ... (10) geo-referenced points in five communities of Ibeno Local Government Area ... water works for provision of good quality drinking water, modern sanitary ... health of the people of Ibeno Local Government Area. ... Nigerian Journal of Technology ... hazards such as gas flaring, oil spillage, washing of.

  15. Health surveys of cyanobacteria in drinking and recreational waters

    Directory of Open Access Journals (Sweden)

    Guadalupe Martínez Juárez

    2008-06-01

    Full Text Available Environmental surveys of drinking and recreational waters with the objective of related health risk control are a common component in public health policy. Based in updated scientific knowledge proliferation of Cyanobacteria constitutes a new risk, and it should be considered in public health programs. The principal objective of this work is to assess the presence of cyanobacteria and microcystins in drinking and recreational waters. Results of a four year survey in the sanitary department of Talavera de la Reina are presented. A descriptive study of the presence of cyanobacteria and microcystins, in non treated water from two reservoirs at the pick up point and after treatment in the exit point from two treatment plants. The same approach has been used in two recreational summer natural water reservoirs. Every fifteen days samples were analysed for cyanobateria recount and free microcystin level determination by ELISA essay. From the results of the analysis in drinking water we concluded that microcystines levels in non treated water from reservoirs are not high, less than 6 per cent of samples showed a positive results for microcystins. Treatment was effective as no sample after treatment showed a positive result for microcystins. 48 per cent of recreational water samples showed levels above 100,000 cells per ml, which corresponds to the WHO moderate adverse effect risk guide level. Public health policy should include systematic level survey of cyanobaterias from drinking and recreational water. Exposure related health adverse effects surveys should be conducted.

  16. Photocatalytic Coats in Glass Drinking-Water Bottles

    Science.gov (United States)

    Andren, Anders W.; Armstrong, David E.; Anderson, Marc A.

    2005-01-01

    According to a proposal, the insides of glass bottles used to store drinking water would be coated with films consisting of or containing TiO2. In the presence of ultraviolet light, these films would help to remove bacteria, viruses, and trace organic contaminants from the water.

  17. Phosphate Removal and Recovery using Drinking Water Plant Waste Residuals

    Science.gov (United States)

    Water treatment plants are used to provide safe drinking water. In parallel, however, they also produce a wide variety of waste products which, in principle, could be possible candidates as resources for different applications. Calcium carbonate is one of such residual waste in ...

  18. Developments in Biotechnology of Relevance to Drinking Water Preparation

    NARCIS (Netherlands)

    Janssen, Dick B.; Witholt, Bernard

    1985-01-01

    This paper discusses strategies to increase the feasibility of microorganisms for the removal of toxic xenobiotics from waste water and drinking water. Based on the principles of adaptational mutations and genetic exchange of catabolic activities, it becomes possible to select and engineer

  19. Toxicological relevance of emerging contaminants for drinking water quality

    NARCIS (Netherlands)

    Schriks, M.; Heringa, M.B.; van der Kooij, M.M.E.; de Voogt, P.; van Wezel, A.P.

    2010-01-01

    The detection of many new compounds in surface water, groundwater and drinking water raises considerable public concern, especially when human health based guideline values are not available it is questioned if detected concentrations affect human health. In an attempt to address this question, we d

  20. Toxicological relevance of emerging contaminants for drinking water quality

    NARCIS (Netherlands)

    Schriks, M.; Heringa, M.B.; van der Kooij, M.M.E.; de Voogt, P.; van Wezel, A.P.

    2010-01-01

    The detection of many new compounds in surface water, groundwater and drinking water raises considerable public concern, especially when human health based guideline values are not available it is questioned if detected concentrations affect human health. In an attempt to address this question, we

  1. Phosphate Removal and Recovery using Drinking Water Plant Waste Residuals

    Science.gov (United States)

    Water treatment plants are used to provide safe drinking water. In parallel, however, they also produce a wide variety of waste products which, in principle, could be possible candidates as resources for different applications. Calcium carbonate is one of such residual waste in ...

  2. Presence of the β-triketone herbicide tefuryltrione in drinking water sources and its degradation product in drinking waters.

    Science.gov (United States)

    Kamata, Motoyuki; Asami, Mari; Matsui, Yoshihiko

    2017-07-01

    Triketone herbicides are becoming popular because of their herbicidal activity against sulfonylurea-resistant weeds. Among these herbicides, tefuryltrione (TFT) is the first registered herbicide for rice farming, and recently its distribution has grown dramatically. In this study, we developed analytical methods for TFT and its degradation product 2-chloro-4-methylsulfonyl-3-[(tetrahydrofuran-2-yl-methoxy) methyl] benzoic acid (CMTBA). TFT was found frequently in surface waters in rice production areas at concentrations as high as 1.9 μg/L. The maximum observed concentration was lower than but close to 2 μg/L, which is the Japanese reference concentration of ambient water quality for pesticides. However, TFT was not found in any drinking waters even though the source waters were purified by conventional coagulation and filtration processes; this was due to chlorination, which transforms TFT to CMTBA. The conversion rate of TFT to CMBA on chlorination was almost 100%, and CMTBA was stable in the presence of chlorine. Moreover, CMTBA was found in drinking waters sampled from household water taps at a similar concentration to that of TFT in the source water of the water purification plant. Although the acceptable daily intake and the reference concentration of CMTBA are unknown, the highest concentration in drinking water exceeded 0.1 μg/L, which is the maximum allowable concentration for any individual pesticide and its relevant metabolites in the European Union Drinking Directive. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Evaluation of ATP measurements to detect microbial ingress by wastewater and surface water in drinking water.

    Science.gov (United States)

    Vang, Óluva K; Corfitzen, Charlotte B; Smith, Christian; Albrechtsen, Hans-Jørgen

    2014-11-01

    Fast and reliable methods are required for monitoring of microbial drinking water quality in order to protect public health. Adenosine triphosphate (ATP) was investigated as a potential real-time parameter for detecting microbial ingress in drinking water contaminated with wastewater or surface water. To investigate the ability of the ATP assay in detecting different contamination types, the contaminant was diluted with non-chlorinated drinking water. Wastewater, diluted at 10(4) in drinking water, was detected with the ATP assay, as well as 10(2) to 10(3) times diluted surface water. To improve the performance of the ATP assay in detecting microbial ingress in drinking water, different approaches were investigated, i.e. quantifying microbial ATP or applying reagents of different sensitivities to reduce measurement variations; however, none of these approaches contributed significantly in this respect. Compared to traditional microbiological methods, the ATP assay could detect wastewater and surface water in drinking water to a higher degree than total direct counts (TDCs), while both heterotrophic plate counts (HPC 22 °C and HPC 37 °C) and Colilert-18 (Escherichia coli and coliforms) were more sensitive than the ATP measurements, though with much longer response times. Continuous sampling combined with ATP measurements displays definite monitoring potential for microbial drinking water quality, since microbial ingress in drinking water can be detected in real-time with ATP measurements. The ability of the ATP assay to detect microbial ingress is influenced by both the ATP load from the contaminant itself and the ATP concentration in the specific drinking water. Consequently, a low ATP concentration of the specific drinking water facilitates a better detection of a potential contamination of the water supply with the ATP assay.

  4. Determination of strontium in drinking water and consequences of radioactive elements present in drinking water for human health

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2006-01-01

    Full Text Available In this paper the analysis of strontium and uranium content in drinking water has been done, indirectly, according to the scale which originates from drinking water in water-supply system of the city of Belgrade. Gamaspectrometric analysis showed the presence of free natural radionuclide in low activities. The activity of 90Sr in scale which is 0.72±0.11 Bq/kg was determined by radiochemical. Because of the small quantities of fur in the house heater this activity can be considered as irrelevant, but the accumulation of scale can have intensified influence. In this paper, the analysis of effects of the radioactive isotopes presence (first of all 238U and 235U in drinking water on human health has been done. .

  5. 75 FR 54872 - Drinking Water Strategy Contaminants as Group(s)-Notice of Public Stakeholder Meeting

    Science.gov (United States)

    2010-09-09

    ..., contact Shari Bauman, Standards and Risk Management Division, Office of Ground Water and Drinking Water... (202) 564-0293 or bauman.shari@epa.gov . For more information about the Drinking Water Strategy,...

  6. Report: EPA Lacks Internal Controls to Prevent Misuse of Emergency Drinking Water Facilities

    Science.gov (United States)

    Report #11-P-0001, October 12, 2010. EPA cannot accurately assess the risk of public water systems delivering contaminated drinking water from emergency facilities because of limitations in Safe Drinking Water Information System (SDWIS) data management.

  7. Updating national standards for drinking-water: a Philippine experience.

    Science.gov (United States)

    Lomboy, M; Riego de Dios, J; Magtibay, B; Quizon, R; Molina, V; Fadrilan-Camacho, V; See, J; Enoveso, A; Barbosa, L; Agravante, A

    2017-04-01

    The latest version of the Philippine National Standards for Drinking-Water (PNSDW) was issued in 2007 by the Department of Health (DOH). Due to several issues and concerns, the DOH decided to make an update which is relevant and necessary to meet the needs of the stakeholders. As an output, the water quality parameters are now categorized into mandatory, primary, and secondary. The ten mandatory parameters are core parameters which all water service providers nationwide are obligated to test. These include thermotolerant coliforms or Escherichia coli, arsenic, cadmium, lead, nitrate, color, turbidity, pH, total dissolved solids, and disinfectant residual. The 55 primary parameters are site-specific and can be adopted as enforceable parameters when developing new water sources or when the existing source is at high risk of contamination. The 11 secondary parameters include operational parameters and those that affect the esthetic quality of drinking-water. In addition, the updated PNSDW include new sections: (1) reporting and interpretation of results and corrective actions; (2) emergency drinking-water parameters; (3) proposed Sustainable Development Goal parameters; and (4) standards for other drinking-water sources. The lessons learned and insights gained from the updating of standards are likewise incorporated in this paper.

  8. Accumulation of arsenic in drinking water distribution systems.

    Science.gov (United States)

    Lytle, Darren A; Sorg, Thomas J; Frietch, Christy

    2004-10-15

    The tendency for iron solid surfaces to adsorb arsenic is well-known and has become the basis for several drinking water treatment approaches that remove arsenic. It is reasonable to assume that iron-based solids, such as corrosion deposits present in drinking water distribution systems, have similar adsorptive properties and could therefore concentrate arsenic and potentially re-release it into the distribution system. The arsenic composition of solids collected from drinking water distribution systems (pipe sections and hydrant flush solids), where the waters had measurable amounts of arsenic in their treated water, were determined. The elemental composition and mineralogy of 67 solid samples collected from 15 drinking water utilities located in Ohio (7), Michigan (7), and Indiana (1) were also determined. The arsenic content of these solids ranged from 10 to 13 650 microg of As/g of solid (as high as 1.37 wt %), and the major element of most solids was iron. Significant amounts of arsenic were even found in solids from systems that were exposed to relatively low concentrations of arsenic (water.

  9. Beyond Flint: National Trends in Drinking Water Quality Violations

    Science.gov (United States)

    Allaire, M.; Wu, H.; Lall, U.

    2016-12-01

    Ensuring safe water supply for communities across the U.S. represents an emerging challenge. Aging infrastructure, impaired source water, and strained community finances may increase vulnerability of water systems to quality violations. In the aftermath of Flint, there is a great need to assess the current state of U.S. drinking water quality. How widespread are violations? What are the spatial and temporal patterns in water quality? Which types of communities and systems are most vulnerable? This is the first national assessment of trends in drinking water quality violations across several decades. In 2015, 9% of community water systems violated health-related water quality standards. These non-compliant systems served nearly 23 million people. Thus, the challenge of providing safe drinking water extends beyond Flint and represents a nationwide concern. We use a panel dataset that includes every community water system in the United States from 1981 to 2010 to identify factors that lead to regulatory noncompliance. This study focuses on health-related violations of the Safe Drinking Water Act. Lasso regression informed selection of appropriate covariates, while logistic regressions modeled the probability of noncompliance. We find that compliance is positively associated with private ownership, purchased water supply, and greater household income. Yet, greater concentration of utility ownership and violations in prior years are associated with a higher likelihood of violation. The results suggest that purchased water contracts, which are growing among small utilities, could serve as a way to improve regulatory compliance in the future. However, persistence of violations and ownership concentration deserve attention from policymakers. Already, the EPA has begun to prioritize enforcement of persistent violators. Overall, as the revitalization of U.S. water infrastructure becomes a growing priority area, results of this study are intended to inform investment and

  10. Hydraulic modelling of drinking water treatment plant operations

    Directory of Open Access Journals (Sweden)

    L. C. Rietveld

    2009-06-01

    Full Text Available The flow through a unit of a drinking water treatment plant is one of the most important parameters in terms of a unit's effectiveness. In the present paper, a new EPAnet library is presented with the typical hydraulic elements for drinking water treatment processes well abstraction, rapid sand filtration and cascade and tower aeration. Using this treatment step library, a hydraulic model was set up, calibrated and validated for the drinking water treatment plant Harderbroek. With the actual valve position and pump speeds, the flows were calculated through the several treatment steps. A case shows the use of the model to calculate the new setpoints for the current frequency converters of the effluent pumps during a filter backwash.

  11. Pathogens in drinking water: Are there any new ones

    Energy Technology Data Exchange (ETDEWEB)

    Reasoner, D.J.

    1993-01-01

    Since 1976 three newly recognized human pathogens have become familiar to the drinking water industry as waterborne disease agents. These are: the legionnaires disease agent, Legionella pneumophila and related species; and two protozoan pathogens, Giardia lamblia and Cryptosporidium parvum, both of which form highly disinfectant resistant cysts that are shed in the feces of infected individuals. The question frequently arises - are there other emerging waterborne pathogens that may pose a human health problem that the drinking water industry will have to deal with. The paper will review the current state of knowledge of the occurrence and incidence of pathogens and opportunistic pathogens other than Legionella, Giardia and Cryptosporidium in treated and untreated drinking water. Bacterial agents that will be reviewed include Aeromonas, Pseudomonas, Campylobacter, Mycobacterium, Yersinia and Plesiomonas. Aspects of detection of these agents including detection methods and feasibility of monitoring will be addressed.

  12. Drinking water consumption patterns in Canadian communities (2001-2007).

    Science.gov (United States)

    Roche, S M; Jones, A Q; Majowicz, S E; McEwen, S A; Pintar, K D M

    2012-03-01

    A pooled analysis of seven cross-sectional studies from Newfoundland and Labrador, Waterloo and Hamilton Regions, Ontario and Vancouver, East Kootenay and Northern Interior Regions, British Columbia (2001 to 2007) was performed to investigate the drinking water consumption patterns of Canadians and to identify factors associated with the volume of tap water consumed. The mean volume of tap water consumed was 1.2 L/day, with a large range (0.03 to 9.0 L/day). In-home water treatment and interactions between age and gender and age and bottled water use were significantly associated with the volume of tap water consumed in multivariable analyses. Approximately 25% (2,221/8,916) of participants were classified as bottled water users, meaning that 75% or more of their total daily drinking water intake was bottled. Approximately 48.6% (4,307/8,799) of participants used an in-home treatment method to treat their tap water for drinking purposes. This study provides a broader geographic perspective and more current estimates of Canadian water consumption patterns than previous studies. The identified factors associated with daily water consumption could be beneficial for risk assessors to identify individuals who may be at greater risk of waterborne illness.

  13. Lung cancer and arsenic concentrations in drinking water in Chile.

    Science.gov (United States)

    Ferreccio, C; González, C; Milosavjlevic, V; Marshall, G; Sancha, A M; Smith, A H

    2000-11-01

    Cities in northern Chile had arsenic concentrations of 860 microg/liter in drinking water in the period 1958-1970. Concentrations have since been reduced to 40 microg/liter. We investigated the relation between lung cancer and arsenic in drinking water in northern Chile in a case-control study involving patients diagnosed with lung cancer between 1994 and 1996 and frequency-matched hospital controls. The study identified 152 lung cancer cases and 419 controls. Participants were interviewed regarding drinking water sources, cigarette smoking, and other variables. Logistic regression analysis revealed a clear trend in lung cancer odds ratios and 95% confidence intervals (CIs) with increasing concentration of arsenic in drinking water, as follows: 1, 1.6 (95% CI = 0.5-5.3), 3.9 (95% CI = 1.2-12.3), 5.2 (95% CI = 2.3-11.7), and 8.9 (95% CI = 4.0-19.6), for arsenic concentrations ranging from less than 10 microg/liter to a 65-year average concentration of 200-400 microg/liter. There was evidence of synergy between cigarette smoking and ingestion of arsenic in drinking water; the odds ratio for lung cancer was 32.0 (95% CI = 7.2-198.0) among smokers exposed to more than 200 microg/liter of arsenic in drinking water (lifetime average) compared with nonsmokers exposed to less than 50 microg/liter. This study provides strong evidence that ingestion of inorganic arsenic is associated with human lung cancer.

  14. Onsite defluoridation system for drinking water treatment using calcium carbonate.

    Science.gov (United States)

    Wong, Elaine Y; Stenstrom, Michael K

    2017-08-28

    Fluoride in drinking water has several effects on teeth and bones. At concentrations of 1-1.5 mg/L, fluoride can strengthen enamel, improving dental health, but at concentrations above 1.5 to 4 mg/L can cause dental fluorosis. At concentrations of 4-10 mg/L, skeletal fluorosis can occur. There are many areas of the world that have excessive fluoride in drinking water, such as China, India, Sri Lanka, and the Rift Valley countries in Africa. Treatment solutions are needed, especially in poor areas where drinking water treatment plants are not available. On-site or individual treatment alternatives can be attractive if constructed from common materials and if simple enough to be constructed and maintained by users. Advanced on-site methods, such as under sink reserve osmosis units, can remove fluoride but are too expensive for developing areas. This paper investigates calcium carbonate as a cost effective sorbent for an onsite defluoridation drinking water system. Batch and column experiments were performed to characterize F(-) removal properties. Fluoride sorption was described by a Freundlich isotherm model, and it was found that the equilibrium time was approximately 3 h. Calcium carbonate was found to have comparable F(-) removal abilities as the commercial ion exchange resins and possessed higher removal effectiveness compared to calcium containing eggshells and seashells. It was also found that the anion Cl- did not compete with F(-) at typical drinking water concentrations, having little impact on the effectiveness of the treatment system. A fluoride removal system is proposed that can be used at home and can be maintained by users. Through this work, we can be a step closer to bringing safe drinking water to those that do not have access to it. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Iodine content in drinking water and other beverages in Denmark

    DEFF Research Database (Denmark)

    Rasmussen, Lone Banke; Larsen, Erik Huusfeldt; Ovesen, L.

    2000-01-01

    Objective: To investigate the variation in iodine content in drinking water in Denmark and to determine the difference in iodine content between organic and non-organic milk. Further, to analyse the iodine content in other beverages. Design and setting: Tap water samples were collected from 41...... evenly distributed localities in Denmark. Organic and non-organic milli was collected at the same time (twice summer and twice winter). Soft drinks, beers and juice were collected from different Danish producers and wine from different countries. All samples were analysed for iodine using inductively...

  16. A brief overview on radon measurements in drinking water.

    Science.gov (United States)

    Jobbágy, Viktor; Altzitzoglou, Timotheos; Malo, Petya; Tanner, Vesa; Hult, Mikael

    2017-07-01

    The aim of this paper is to present information about currently used standard and routine methods for radon analysis in drinking waters. An overview is given about the current situation and the performance of different measurement methods based on literature data. The following parameters are compared and discussed: initial sample volume and sample preparation, detection systems, minimum detectable activity, counting efficiency, interferences, measurement uncertainty, sample capacity and overall turnaround time. Moreover, the parametric levels for radon in drinking water from the different legislations and directives/guidelines on radon are presented. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Feasibility Test of Refill Drinking Water in Batam

    OpenAIRE

    ., Hazimah; Triwuri, Nurlinda Ayu

    2016-01-01

    According to the Regulation of the Minister of Health No.492 Year 2010, drinking water quality is assessed from the chemistry parameters, one of them is aluminium (Al), iron (Fe), kloride (Cl) and copper (Cu), it should meet the standards that have been defined. The aim of this research is to find out the quality of refill drinking water in Batam with indicator aluminium (Al), iron (Fe), kloride (Cl) and copper (Cu). The research was conducted in the laboratory of PT. Sucofindo Batam, Riau Is...

  18. EVALUATION OF EFFECTIVENESS OF HOUSEHOLD DRINKING WATER FILTRATION

    Directory of Open Access Journals (Sweden)

    Karolina Jezierska

    2014-10-01

    Full Text Available The aim of this study was to analyze the effectiveness of household drinking water filtration. This article demonstrates the possibilities of using study on the reaction of ascorbic acid degradation in aqueous solutions to develop a new method for determining the effectiveness of household drinking water filtration. Based on the measurements of absorbance of ascorbic acid a new parameters WCW (Coeffi cient of Water Purity and SF (Filtration Degree were defined. Correlations between the SF and the amount of filtered water (filter usage were investigated. With the filter usage decreasing effectiveness of calcium ions removal and drop of differences in conductivity between the tap and filtered water were observed. SF decreases proportionally to the filter usage and therefore the proposed method can be an effective tool to determine the effectiveness of domestic water filters.

  19. Latest Technologies and Equipment to Obtain High Quality Drinking Water

    Directory of Open Access Journals (Sweden)

    Goncharuk, V.V.

    2015-01-01

    Full Text Available A principally new concept of providing the Ukrainian population with quality drinking water have been proposed. It is based on a system of autonomous complexes for water purification in places of direct consumption. Water treatment autonomous complexes for collective and individual use with biotesting and analytical quality control of drinking water have been developed. The choice of the cleaning methods of tap and other waters up to the quality of genetic safe is performed in accordance with its composition and is based on a block concept that provides the possibility of varying the number of units depending on the composition of the source water. The proposed technology and equipment at cost and complex problems to be solved have no analogues in the world. Over thousand of modular installations «Vega» and disinfecting vehicles «Promin» are implemented in many settlement in all regions of Ukraine.

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

    Science.gov (United States)

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

    2013-01-01

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

  1. Plant wide chemical water stability modelling with PHREEQC for drinking water treatment

    NARCIS (Netherlands)

    Van der Helm, A.W.C.; Kramer, O.J.I.; Hooft, J.F.M.; De Moel, P.J.

    2015-01-01

    In practice, drinking water technologists use simplified calculation methods for aquatic chemistry calculations. Recently, the database stimela.dat is developed especially for aquatic chemistry for drinking water treatment processes. The database is used in PHREEQC, the standard in geohydrology for

  2. Plant wide chemical water stability modelling with PHREEQC for drinking water treatment

    NARCIS (Netherlands)

    Van der Helm, A.W.C.; Kramer, O.J.I.; Hooft, J.F.M.; De Moel, P.J.

    2015-01-01

    In practice, drinking water technologists use simplified calculation methods for aquatic chemistry calculations. Recently, the database stimela.dat is developed especially for aquatic chemistry for drinking water treatment processes. The database is used in PHREEQC, the standard in geohydrology for

  3. Alternative technology for arsenic removal from drinking water

    OpenAIRE

    Purenović Milovan

    2007-01-01

    Arsenic is a naturally occurring element in water, food and air. It is known as a poison, but in very small quantities it is showed to be an essential element. Actual problem in the world is arsenic removal from drinking water using modern and alternative technology, especially because EPA's and other international standards have reduced MCL from 50 to 10 ug/1. Because of rivers and lakes pollution, in a number of plants for natural water purification, average concentrations of arsenic in wat...

  4. Relationship Between Microcystin in Drinking Water and Colorectal Cancer

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective To investigate the association of microcystin (MC) in drinking water with the incidence of colorectal cancer. Methods The study was designed as a retrospective cohort. Eight townships or towns were randomly selected as the study sites in Haining City of Zhejiang Province, China. 408 cases of colon and rectum carcinomas diagnosed from 1977 to 1996 in the study sites were included, and a survey on types of drinking water of these patients was conducted. Samples of different water sources (well, tap, river and pond) were collected separately and microcystin concentrations were determined by indirect competitive ELISA method. Results The incidence rate of colorectal cancer was significantly higher in population who drank river and pond water than those who drank well and tap water. Compared to well water, the relative risk (RR) for colorectal cancer was 1.88 (tap), 7.94 (river) and 7.70 (pond) respectively. The positive rate (>50 pg/mL) of microcystin in samples of well, tap, river and pond water was 0, 0, 36.23% and 17.14% respectively. The concentration of microcystin in river and pond water was significantly higher than that in well and tap water (P<0.01). Spearman rank correlation analysis showed that in the study sites, the microcystin concentration of river and pond water was positively associated with the incidence of colorectal cancer (rs= 0.881, P<0.01). Conclusions The types of drinking water are positively associated with the incidence of colorectal cancer in the study sites, and this may be related to microcystin contamination of drinking water. Further biological study is needed to support the possible causative role of mycrocystin in carcinogenesis of colon and rectum.

  5. Exploring Perceptions and Behaviors about Drinking Water in Australia and New Zealand: Is It Risky to Drink Water, When and Why?

    Directory of Open Access Journals (Sweden)

    Andrea Crampton

    2016-02-01

    Full Text Available Consumers in most developed countries, including Australia and New Zealand, presume their drinking water is safe. How social perceptions about drinking water are formed, however, remains inadequately explored in the research literature. This research contributes exploratory insights by examining factors that affect consumer perceptions and behaviors. Individual perceptions of drinking water quality and actions undertaken to mitigate perceived risks were collected during 183 face-to-face interviews conducted at six research sites. Qualitative thematic analysis revealed the majority did not consider drinking water a “risky” activity, trusted water management authorities to manage all safety issues and believed self-evaluation of drinking water’s taste and appearance were sufficient measures to ensure safe consumption. Quantitatively, significant relationships emerged between water quality perceptions and sex, employment status, drinking water treatment and trust in government to provide safe water. Expert advice was rarely sought, even by those who believed drinking tap water posed some health risks. Generational differences emerged in media usage for drinking water advice. Finally, precautionary measures taken at home and abroad often failed to meet national drinking water guidelines. Three major conclusions are drawn: a. broad lack of awareness exists about the most suitable and safe water treatment activities, as well as risks posed; b. health literacy and interest may be improved through greater consumer involvement in watershed management; and c. development of health campaigns that clearly communicate drinking water safety messages in a timely, relevant and easily understandable fashion may help mitigate actual risks and dispel myths.

  6. Water quality modeling in the dead end sections of drinking water (Supplement)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Dead-end sections of drinking water distribution networks are known to be problematic zones in terms of water quality degradation. Extended residence time due to...

  7. CO2 emissions from German drinking water reservoirs.

    Science.gov (United States)

    Saidi, Helmi; Koschorreck, Matthias

    2017-03-01

    Globally, reservoirs are a significant source of atmospheric CO2. However, precise quantification of greenhouse gas emissions from drinking water reservoirs on the regional or national scale is still challenging. We calculated CO2 fluxes for 39 German drinking water reservoirs during a period of 22years (1991-2013) using routine monitoring data in order to quantify total emission of CO2 from drinking water reservoirs in Germany and to identify major drivers. All reservoirs were a net CO2 source with a median flux of 167gCm(-2)y(-1), which makes gaseous emissions a relevant process for the carbon budget of each reservoir. Fluxes varied seasonally with median fluxes of 13, 48, and 201gCm(-2)y(-1) in spring, summer, and autumn respectively. Differences between reservoirs appeared to be primarily caused by the concentration of CO2 in the surface water rather than by the physical gas transfer coefficient. Consideration of short term fluctuations of the gas transfer coefficient due to varying wind speed had only a minor effect on the annual budgets. High CO2 emissions only occurred in reservoirs with pHCO2 emissions correlated exponentially with pH but not with dissolved organic carbon (DOC). There was significant correlation between land use in the catchment and CO2 emissions. In total, German drinking water reservoirs emit 44000t of CO2 annually, which makes them a negligible CO2 source (CO2 emissions) in Germany.

  8. [Moulds and yeasts in bottled water and soft drinks].

    Science.gov (United States)

    Ancasi, E G; Carrillo, L; Benítez Ahrendts, M R

    2006-01-01

    Some damaged cartons of soft drinks and carbonated water were analyzed to detect the microorganisms that caused the damage. The contaminants of sugar used in the production of one of the drinks were also studied. The methods of Déak & Beuchat and Pitt & Hocking were used for the identification of yeasts and moulds, respectively. The agents of the spoilage of soft drinks were Debaryomyces hansenii, Debaryomyces polymorphus, Galactomyces geotrichum, Metschnikowia pulcherrima, Mucor circinelloides, Pichia anomala, Pichia jadinii, Pichia subpelliculosa, Rhodotorula glutinis and Zygosaccharomyces bailii. The microorganisms found in sugar were Aspergillus niger, Aspergillus penicilloides, Aspergillus versicolor, Cladosporium sphaerospermum, Mucor racemosus, P. anomala and Rhizopus stolonifer. Paecilomyces fulvus and Penicillium glabrum were observed in carbonated water.

  9. Effects of slightly acidic electrolysed drinking water on mice.

    Science.gov (United States)

    Inagaki, Hideaki; Shibata, Yoshiko; Obata, Takahiro; Kawagoe, Masami; Ikeda, Katsuhisa; Sato, Masayoshi; Toida, Kazumi; Kushima, Hidemi; Matsuda, Yukihisa

    2011-10-01

    Slightly acidic electrolysed (SAE) water is a sanitizer with strong bactericidal activity due to hypochlorous acid. We assessed the safety of SAE water as drinking water for mice at a 5 ppm total residual chlorine (TRC) concentration to examine the possibility of SAE water as a labour- and energy-saving alternative to sterile water. We provided SAE water or sterile water to mice for 12 weeks, during which time we recorded changes in body weight and weekly water and food intakes. At the end of the experiment, all of the subject animals were sacrificed to assess serum aspartate aminotransferase, alanine aminotransferase and creatinine levels and to examine the main organs histopathologically under a light microscope. In addition, we investigated the bacteria levels of both types of water. We found no difference in functional and morphological health condition indices between the groups. Compared with sterile water, SAE water had a relatively higher ability to suppress bacterial growth. We suggest that SAE water at 5 ppm TRC is a safe and useful alternative to sterile water for use as drinking water in laboratory animal facilities.

  10. Water quality and management of private drinking water wells in Pennsylvania.

    Science.gov (United States)

    Swistock, Bryan R; Clemens, Stephanie; Sharpe, William E; Rummel, Shawn

    2013-01-01

    Pennsylvania has over three million rural residents using private water wells for drinking water supplies but is one of the few states that lack statewide water well construction or management standards. The study described in this article aimed to determine the prevalence and causes of common health-based pollutants in water wells and evaluate the need for regulatory management along with voluntary educational programs. Water samples were collected throughout Pennsylvania by Master Well Owner Network volunteers trained by Penn State Extension. Approximately 40% of the 701 water wells sampled failed at least one health-based drinking water standard. The prevalence of most water quality problems was similar to past studies although both lead and nitrate-N were reduced over the last 20 years. The authors' study suggests that statewide water well construction standards along with routine water testing and educational programs to assist water well owners would result in improved drinking water quality for private well owners in Pennsylvania.

  11. 75 FR 53267 - National Primary Drinking Water Regulations: Revisions to the Total Coliform Rule; Extension of...

    Science.gov (United States)

    2010-08-31

    ... AGENCY 40 CFR Parts 141 and 142 RIN 2040-AD94 National Primary Drinking Water Regulations: Revisions to... 30 days the public comment period for a proposed National Primary Drinking Water Regulation, the... inquiries, contact Sean Conley, Office of Ground Water and Drinking Water (MC 4607M), U.S....

  12. 78 FR 48158 - Meeting of the National Drinking Water Advisory Council

    Science.gov (United States)

    2013-08-07

    .... SUMMARY: The U.S. Environmental Protection Agency is announcing a meeting of the National Drinking Water Advisory Council (Council), established under the Safe Drinking Water Act (SDWA). This meeting is scheduled... associated with drinking water protection and public water systems. During this meeting, the Council...

  13. 76 FR 67187 - National Drinking Water Advisory Council; Notice of a Public Teleconference Meeting

    Science.gov (United States)

    2011-10-31

    ... AGENCY National Drinking Water Advisory Council; Notice of a Public Teleconference Meeting AGENCY..., Office of Ground Water and Drinking Water (Mail Code 4601M), 1200 Pennsylvania Avenue NW., Washington, DC... the Safe Drinking Water Act (SDWA) of 1974 to provide practical and independent advice,...

  14. Safe Drinking Water for Alaska: Curriculum for Grades 1-6.

    Science.gov (United States)

    South East Regional Resource Center, Juneau, AK.

    Presented is a set of 10 lessons on safe drinking water in Alaska for use by elementary school teachers. The aim is to provide students with an understanding of the sources of the water they drink, how drinking water can be made safe, and the health threat that unsafe water represents. Although this curriculum relates primarily to science, health,…

  15. 78 FR 73206 - Notice of Lodging of Proposed Consent Decree Under the Safe Drinking Water Act

    Science.gov (United States)

    2013-12-05

    ... of Lodging of Proposed Consent Decree Under the Safe Drinking Water Act On November 23, 2013 the... requirements of the Safe Drinking Water Act and the National Primary Drinking Water Regulations (``NPDWRs...-142-F. The action concerns the public water system the defendant, Bryan Pownall (``Defendant'')...

  16. Heavy metal pollution in drinking water - a global risk for human health

    African Journals Online (AJOL)

    Heavy metal pollution in drinking water - a global risk for human health: A review. ... is currently facing critical water supply and drinking water quality problems. ... the HM pollution in drinking water, the incorporation of them into the food chain, ...

  17. Evaluation of Minerals Content of Drinking Water in Malaysia

    Directory of Open Access Journals (Sweden)

    Azrina Azlan

    2012-01-01

    Full Text Available The drinking and mineral water samples obtained from different geographical locations had concentrations of the selected minerals lower than the standard limits, except for manganese, arsenic, and fluoride. The concentrations of manganese and arsenic in two mineral water samples were slightly higher than the standard international recommended limits. One mineral water sample had a fluoride concentration higher than the standard limits, whereas manganese was not detected in nine drinking and mineral water samples. Most of the selected minerals found in the tap water samples were below the international standard limits, except for iron and manganese. The concentrations of iron and manganese in the tap water samples were higher than the standard limits, which were obtained from one and three of the studied locations, respectively. The potable water obtained from various manufacturers and locations in Peninsular Malaysia is safe for consumption, as the minerals concentrations were below the standard limits prescribed by the Malaysian Food Regulations of 1985. The data obtained may also provide important information related to daily intake of these minerals from drinking water.

  18. Evaluation of minerals content of drinking water in Malaysia.

    Science.gov (United States)

    Azlan, Azrina; Khoo, Hock Eng; Idris, Mohd Aizat; Ismail, Amin; Razman, Muhammad Rizal

    2012-01-01

    The drinking and mineral water samples obtained from different geographical locations had concentrations of the selected minerals lower than the standard limits, except for manganese, arsenic, and fluoride. The concentrations of manganese and arsenic in two mineral water samples were slightly higher than the standard international recommended limits. One mineral water sample had a fluoride concentration higher than the standard limits, whereas manganese was not detected in nine drinking and mineral water samples. Most of the selected minerals found in the tap water samples were below the international standard limits, except for iron and manganese. The concentrations of iron and manganese in the tap water samples were higher than the standard limits, which were obtained from one and three of the studied locations, respectively. The potable water obtained from various manufacturers and locations in Peninsular Malaysia is safe for consumption, as the minerals concentrations were below the standard limits prescribed by the Malaysian Food Regulations of 1985. The data obtained may also provide important information related to daily intake of these minerals from drinking water.

  19. Development and application of innovative technologies for drinking water quality assurance in China

    Institute of Scientific and Technical Information of China (English)

    QU Jiuhui; YIN Chengqing; YANG Min; LIU Huijuan

    2007-01-01

    The continuously deteriorating quality of source water is threatening the safety of drinking water in China.Various efforts have been made to update water treatment processes to decrease the pollution problems of drinking water,such as protection of drinking water sources,enhancement of conventional treatment processes,and development of new or advanced treatment technologies.This paper reviews a variety of protection and remediation methods for drinking water sources,development and application of drinking water treatment technologies,new technologies for special pollutants removal from groundwater,and the latest research progress on water distribution systems in China.

  20. Persistence and decontamination of surrogate radioisotopes in a model drinking water distribution system.

    Science.gov (United States)

    Szabo, Jeffrey G; Impellitteri, Christopher A; Govindaswamy, Shekar; Hall, John S

    2009-12-01

    Contamination of a model drinking water system with surrogate radioisotopes was examined with respect to persistence on and decontamination of infrastructure surfaces. Cesium and cobalt chloride salts were used as surrogates for cesium-137 and cobalt-60. Studies were conducted in biofilm annular reactors containing heavily corroded iron surfaces formed under shear and constantly submerged in drinking water. Cesium was not detected on the corroded iron surface after equilibration with 10 and 100mgL(-1) solutions of cesium chloride, but cobalt was detected on corroded iron coupons at both initial concentrations. The amount of adhered cobalt decreased over the next six weeks, but was still present when monitoring stopped. X-ray absorption near-edge spectroscopy (XANES) showed that adhered cobalt was in the III oxidation state. The adsorbed cobalt was strongly resistant to decontamination by various physicochemical methods. Simulated flushing, use of free chlorine and dilute ammonia were found to be ineffective whereas use of aggressive methods like 14.5M ammonia and 0.36M sulfuric acid removed 37 and 92% of the sorbed cobalt, respectively.

  1. Differences in dissolved organic matter between reclaimed water source and drinking water source.

    Science.gov (United States)

    Hu, Hong-Ying; Du, Ye; Wu, Qian-Yuan; Zhao, Xin; Tang, Xin; Chen, Zhuo

    2016-05-01

    Dissolved organic matter (DOM) significantly affects the quality of reclaimed water and drinking water. Reclaimed water potable reuse is an effective way to augment drinking water source and de facto reuse exists worldwide. Hence, when reclaimed water source (namely secondary effluent) is blended with drinking water source, understanding the difference in DOM between drinking water source (dDOM) and reclaimed water source (rDOM) is essential. In this study, composition, transformation, and potential risk of dDOM from drinking water source and rDOM from secondary effluent were compared. Generally, the DOC concentration of rDOM and dissolved organic nitrogen (DON) content in reclaimed water source were higher but rDOM exhibited a lower aromaticity. Besides, rDOM comprises a higher proportion of hydrophilic fractions and more low-molecular weight compounds, which are difficult to be removed during coagulation. Although dDOM exhibited higher specific disinfection byproducts formation potential (SDBPFP), rDOM formed more total disinfection byproducts (DBPs) during chlorination including halomethanes (THMs) and haloacetic acids (HAAs) due to high DOC concentration. Likewise, in consideration of DOC basis, rDOM contained more absolute assimilable organic carbon (AOC) despite showing a lower specific AOC (normalized AOC per unit of DOC). Besides, rDOM exhibited higher biotoxicity including genotoxicity and endocrine disruption. Therefore, rDOM presents a greater potential risk than dDOM does. Reclaimed water source needs to be treated carefully when it is blended with drinking water source.

  2. Arsenic in drinking water and adverse birth outcomes in Ohio.

    Science.gov (United States)

    Almberg, Kirsten S; Turyk, Mary E; Jones, Rachael M; Rankin, Kristin; Freels, Sally; Graber, Judith M; Stayner, Leslie T

    2017-08-01

    Arsenic in drinking water has been associated with adverse reproductive outcomes in areas with high levels of naturally occurring arsenic. Less is known about the reproductive effects of arsenic at lower levels. This research examined the association between low-level arsenic in drinking water and small for gestational age (SGA), term low birth weight (term LBW), very low birth weight (VLBW), preterm birth (PTB), and very preterm birth (VPTB) in the state of Ohio. Exposure was defined as the mean annual arsenic concentration in drinking water in each county in Ohio from 2006 to 2008 using Safe Drinking Water Information System data. Birth outcomes were ascertained from the birth certificate records of 428,804 births in Ohio from the same time period. Multivariable generalized estimating equation logistic regression models were used to assess the relationship between arsenic and each birth outcome separately. Sensitivity analyses were performed to examine the roles of private well use and prenatal care utilization in these associations. Arsenic in drinking water was associated with increased odds of VLBW (AOR 1.14 per µg/L increase; 95% CI 1.04, 1.24) and PTB (AOR 1.10; 95% CI 1.06, 1.15) among singleton births in counties where water was positively associated with VLBW and PTB in a population where nearly all (>99%) of the population was exposed under the current maximum contaminant level of 10µg/L. Current regulatory standards may not be protective against reproductive effects of prenatal exposure to arsenic. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Fluoride in Drinking Water -Its Effects and Removal

    Directory of Open Access Journals (Sweden)

    Ram Gopal

    1985-01-01

    Full Text Available Occurrence of fluoride in water, its metabolism, excretion. effect oingestion in human and cattle system and methods of fluoridation and defluoridation have been discussed. The presence of fluoride in waters occurring in India, with special reference to Rajasthan desert has been reviewed. Based on the survey and physico-chemical analyses of about 2,700 water samples of Rajasthan, distribution of fluoride in this area has been discussed wrth reference to drinking water standards. A water resources map showing concentrations of fluoride in four arid districts of Rajasthan is also presented.

  4. 9 CFR 3.115 - Food and drinking water requirements.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Food and drinking water requirements. 3.115 Section 3.115 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling, Care,...

  5. Metagenomic Analyses of Drinking Water Receiving Different Disinfection Treatments

    Science.gov (United States)

    A metagenome-based approach was utilized for assessing the taxonomic affiliation and function potential of microbial populations in free chlorine (CHL) and monochloramine (CHM) treated drinking water (DW). A total of 1,024, 242 (averaging 544 bp) and 849, 349 (averaging 554 bp) ...

  6. Why Drinking Water Is the Way to Go

    Science.gov (United States)

    ... A Movies & More Quizzes Kids' Dictionary of Medical Words En Español What Other Kids Are Reading Taking Care of Your Ears Taking Care of Your Skin Taking Care of Your Teeth El cuidado de los dientes Video: Getting an X-ray Why Drinking Water Is the Way to Go KidsHealth > For Kids > ...

  7. Spectrophotometric determination of fluoride in drinking water using ...

    African Journals Online (AJOL)

    2011-03-14

    Mar 14, 2011 ... for 1.5 mg∙ℓ-1 fluoride for the method using chrome azurol B were ... in drinking water can give rise to a number of adverse effects ... reagents, due to their spectrophotometric properties described .... Possible structure for aluminium chrome azurol B 1:2 complex ..... zirconium-eriochrome cyanine R. Anal.

  8. COMPARATIVE RISK DILEMNAS IN DRINKING WATER DISINFECTION [EDITORIAL

    Science.gov (United States)

    Disinfection of drinking water supplies has been one of the most succesful public health interventions of the twentieth century. It has virtually eliminated outbreaks of serious waterborne infectious diseases, such as cholera and typhoid. there are still, however, an average of...

  9. Pipe failure predictions in drinking water systems using satellite observations

    NARCIS (Netherlands)

    Arsénio, André Marques; Dheenathayalan, Prabu; Hanssen, Ramon; Vreeburg, Jan; Rietveld, Luuk

    2015-01-01

    Soil deformation is believed to play a crucial role in the onset of failures in the underground infrastructure. This article describes a method to generate a replacement-prioritisation map for underground drinking water pipe networks using ground movement data. A segment of the distribution netwo

  10. 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

  11. Pipe failure predictions in drinking water systems using satellite observations

    NARCIS (Netherlands)

    Arsénio, André Marques; Dheenathayalan, Prabu; Hanssen, Ramon; Vreeburg, Jan; Rietveld, Luuk

    2015-01-01

    Soil deformation is believed to play a crucial role in the onset of failures in the underground infrastructure. This article describes a method to generate a replacement-prioritisation map for underground drinking water pipe networks using ground movement data. A segment of the distribution

  12. Drinking water assessment of 4 locations from Ghaziabad, Uttar Pradesh

    Directory of Open Access Journals (Sweden)

    Shikha Bisht

    2013-04-01

    Full Text Available In this study drinking water samples from 4 different locations in Ghaziabad were collected by random grab sampling. These were analyzed for physiochemical and elemental parameters. The parameters tested were pH, Nitrate, Fluoride, Chloride, Sulphate, Total Dissolved solids, Hardness, Alkalinity, Calcium, Magnesium, Aluminium, Boron, Zinc, Selenium, Manganese, Iron, Chromium, Copper, Lead, Cadmium, Arsenic and Mercury.

  13. TAPWAT: Definition structure and applications for modelling drinking water treatment

    NARCIS (Netherlands)

    Versteegh JFM; van Gaalen FW; Rietveld LC; Evers EG; Aldenberg TA; Cleij P; LWD

    2001-01-01

    Het model TAPWAT (Tool for the Analysis of the Production of drinking WATer), is ontwikkeld om de drinkwaterkwaliteit te beschrijven voor integrale studies in het kader van het planbureau Milieu en Natuur van het RIVM. Het model bestaat uit modules die de individuele zuiveringsstappen van het

  14. Dimethylamine biodegradation by mixed culture enriched from drinking water biofilter.

    Science.gov (United States)

    Liao, Xiaobin; Chen, Chao; Zhang, Jingxu; Dai, Yu; Zhang, Xiaojian; Xie, Shuguang

    2015-01-01

    Dimethylamine (DMA) is one of the important precursors of drinking water disinfection by-product N-nitrosodimethylamine (NDMA). Reduction of DMA to minimize the formation of carcinogenic NDMA in drinking water is of practical importance. Biodegradation plays a major role in elimination of DMA pollution in the environment, yet information on DMA removal by drinking water biofilter is still lacking. In this study, microcosms with different treatments were constructed to investigate the potential of DMA removal by a mixed culture enriched from a drinking water biofilter and the effects of carbon and nitrogen sources. DMA could be quickly mineralized by the enrichment culture. Amendment of a carbon source, instead of a nitrogen source, had a profound impact on DMA removal. A shift in bacterial community structure was observed with DMA biodegradation, affected by carbon and nitrogen sources. Proteobacteria was the predominant phylum group in DMA-degrading microcosms. Microorganisms from a variety of bacterial genera might be responsible for the rapid DMA mineralization. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Drinking Water Activities for Students, Teachers, and Parents.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC.

    This guide provides teachers with materials, information, and classroom activities to enhance any drinking water curriculum. Students can use the activity sheets to further lessons and stimulate thought. Parents can use the guide to develop science projects that will provoke thought, encourage research, and provide a scientific approach to…

  16. 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...

  17. 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

  18. Arsenic in Drinking Water--The Silent Killer

    Science.gov (United States)

    Wajrak, Magdalena

    2011-01-01

    Natural arsenic salts are present in all waters, with natural concentrations of less than 10 parts per billion (ppb). Unfortunately, there is an increasing number of countries where toxic arsenic compounds in groundwater, which is used for drinking and irrigation, have been detected at concentrations above the World Health Organization's…

  19. Arsenic in Drinking Water--The Silent Killer

    Science.gov (United States)

    Wajrak, Magdalena

    2011-01-01

    Natural arsenic salts are present in all waters, with natural concentrations of less than 10 parts per billion (ppb). Unfortunately, there is an increasing number of countries where toxic arsenic compounds in groundwater, which is used for drinking and irrigation, have been detected at concentrations above the World Health Organization's…

  20. Metagenomic Analyses of Drinking Water Receiving Different Disinfection Treatments

    Science.gov (United States)

    A metagenome-based approach was utilized for assessing the taxonomic affiliation and function potential of microbial populations in free chlorine (CHL) and monochloramine (CHM) treated drinking water (DW). A total of 1,024, 242 (averaging 544 bp) and 849, 349 (averaging 554 bp) ...

  1. Geospatial examination of lithium in drinking water and suicide mortality

    Directory of Open Access Journals (Sweden)

    Helbich Marco

    2012-06-01

    Full Text Available Abstract Background Lithium as a substance occurring naturally in food and drinking water may exert positive effects on mental health. In therapeutic doses, which are more than 100 times higher than natural daily intakes, lithium has been proven to be a mood-stabilizer and suicide preventive. This study examined whether natural lithium content in drinking water is regionally associated with lower suicide rates. Methods Previous statistical approaches were challenged by global and local spatial regression models taking spatial autocorrelation as well as non-stationarity into account. A Geographically Weighted Regression model was applied with significant independent variables as indicated by a spatial autoregressive model. Results The association between lithium levels in drinking water and suicide mortality can be confirmed by the global spatial regression model. In addition, the local spatial regression model showed that the association was mainly driven by the eastern parts of Austria. Conclusions According to old anecdotic reports the results of this study support the hypothesis of positive effects of natural lithium intake on mental health. Both, the new methodological approach and the results relevant for health may open new avenues in the collaboration between Geographic Information Science, medicine, and even criminology, such as exploring the spatial association between violent or impulsive crime and lithium content in drinking water.

  2. Model-Based Control of Drinking-Water Treatment Plants

    NARCIS (Netherlands)

    Van Schagen, K.M.

    2009-01-01

    The drinking water in the Netherlands is of high quality and the production cost is low. This is the result of extensive research in the past decades to innovate and optimise the treatment processes. The processes are monitored and operated by motivated and skilled operators and process technologist

  3. 77 FR 61027 - Notice of Lodging of Proposed Consent Decree Under the Clean Water Act and Safe Drinking Water Act

    Science.gov (United States)

    2012-10-05

    ... Clean Water Act and Safe Drinking Water Act at mobile home parks operated by defendants in Pennsylvania, Delaware and Virginia. The defendants treat sewage and provide drinking water at a number of its mobile... about drinking water problems. The Consent Decree requires payment of a civil penalty of...

  4. Evaluation of ATP measurements to detect microbial ingress by wastewater and surface water in drinking water

    DEFF Research Database (Denmark)

    Vang, Óluva Karin; Corfitzen, Charlotte B.; Smith, Christian

    2014-01-01

    in this respect. Compared to traditional microbiological methods, the ATP assay could detect wastewater and surface water in drinking water to a higher degree than total direct counts (TDCs), while both heterotrophic plate counts (HPC 22 °C and HPC 37 °C) and Colilert-18 (Escherichia coli and coliforms) were more......Fast and reliable methods are required for monitoring of microbial drinking water quality in order to protect public health. Adenosine triphosphate (ATP) was investigated as a potential real-time parameter for detecting microbial ingress in drinking water contaminated with wastewater or surface...

  5. Drinking water contamination and treatment techniques

    Science.gov (United States)

    Sharma, S.; Bhattacharya, A.

    2016-08-01

    Water is of fundamental importance for life on earth. The synthesis and structure of cell constituents and transport of nutrients into the cells as well as body metabolism depend on water. The contaminations present in water disturb the spontaneity of the mechanism and result in long/short-term diseases. The probable contaminations and their possible routes are discussed in the present review. Continued research efforts result in some processes/technologies to remove the contaminations from water. The review includes concepts and potentialities of the technologies in a comprehensible form. It also includes some meaningful hybrid technologies and promising awaited technologies in coming years.

  6. Drinking water contamination and treatment techniques

    Science.gov (United States)

    Sharma, S.; Bhattacharya, A.

    2017-06-01

    Water is of fundamental importance for life on earth. The synthesis and structure of cell constituents and transport of nutrients into the cells as well as body metabolism depend on water. The contaminations present in water disturb the spontaneity of the mechanism and result in long/short-term diseases. The probable contaminations and their possible routes are discussed in the present review. Continued research efforts result in some processes/technologies to remove the contaminations from water. The review includes concepts and potentialities of the technologies in a comprehensible form. It also includes some meaningful hybrid technologies and promising awaited technologies in coming years.

  7. Chemical Biology Strategies for Biofilm Control.

    Science.gov (United States)

    Yang, Liang; Givskov, Michael

    2015-08-01

    Microbes live as densely populated multicellular surface-attached biofilm communities embedded in self-generated, extracellular polymeric substances (EPSs). EPSs serve as a scaffold for cross-linking biofilm cells and support development of biofilm architecture and functions. Biofilms can have a clear negative impact on humans, where biofilms are a common denominator in many chronic diseases in which they prime development of destructive inflammatory conditions and the failure of our immune system to efficiently cope with them. Our current assortment of antimicrobial agents cannot efficiently eradicate biofilms. For industrial applications, the removal of biofilms within production machinery in the paper and hygienic food packaging industry, cooling water circuits, and drinking water manufacturing systems can be critical for the safety and efficacy of those processes. Biofilm formation is a dynamic process that involves microbial cell migration, cell-to-cell signaling and interactions, EPS synthesis, and cell-EPS interactions. Recent progress of fundamental biofilm research has shed light on novel chemical biology strategies for biofilm control. In this article, chemical biology strategies targeting the bacterial intercellular and intracellular signaling pathways will be discussed.

  8. Risk assessment of fluoride exposure in drinking water of Tunisia.

    Science.gov (United States)

    Guissouma, Wiem; Hakami, Othman; Al-Rajab, Abdul Jabbar; Tarhouni, Jamila

    2017-06-01

    The presence of fluoride in drinking water is known to reduce dental cavities among consumers, but an excessive intake of this anion might leads to dental and skeletal fluorosis. This study reports a complete survey of the fluoridated tap water taken from 100 water consumption points in Tunisia. The fluoride concentrations in tap water were between 0 and 2.4 mg L(-1). Risk assessment of Fluoride exposure was assessed depending on the age of consumers using a four-step method: hazard identification, toxicity reference values selection (TRVs), daily exposure assessment, and risk characterization. Our findings suggest that approximately 75% of the Tunisian population is at risk for dental decay, 25% have a potential dental fluorosis risk, and 20% might have a skeletal fluorosis risk according to the limits of fluoride in drinking water recommended by WHO. More investigations are recommended to assess the exposure risk of fluoride in other sources of drinking water such as bottled water. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Feasibility of sulfide control in sewers by reuse of iron rich drinking water treatment sludge.

    Science.gov (United States)

    Sun, Jing; Pikaar, Ilje; Sharma, Keshab Raj; Keller, Jürg; Yuan, Zhiguo

    2015-03-15

    Dosage of iron salt is the most commonly used method for sulfide control in sewer networks but incurs high chemical costs. In this study, we experimentally investigate the feasibility of using iron rich drinking water treatment sludge for sulfide control in sewers. A lab-scale rising main sewer biofilm reactor was used. The sulfide concentration in the effluent decreased from 15.5 to 19.8 mgS/L (without dosing) to below 0.7-2.3 mgS/L at a sludge dosing rate achieving an iron to total dissolved inorganic sulfur molar ratio (Fe:S) of 1:1, with further removal of sulfide possible by prolonging the reaction time. In fact, batch tests revealed an Fe consumption to sulfide removal ratio of 0.5 ± 0.02 (mole:mole), suggesting the possible occurrence of other reactions involving the removal of sulfide. Modelling revealed that the reaction between iron in sludge and sulfide has reaction orders of 0.65 ± 0.01 and 0.77 ± 0.02 with respect to the Fe and sulfide concentrations, respectively. The addition of sludge slightly increased the total chemical oxidation demand (tCOD) concentration (by approximately 12%) as expected, but decreased the soluble chemical oxidation demand (sCOD) concentration and methane formation by 7% and 20%, respectively. Some phosphate removal (13%) was also observed at the sludge dosing rate of 1:1 (Fe:S), which is beneficial to nutrient removal from the wastewater. Overall, this study suggests that dosing iron-rich drinking water sludge to sewers could be an effective strategy for sulfide removal in sewer systems, which would also reduce the sludge disposal costs for drinking water treatment works. However, its potential side-effects on sewer sedimentation and on the wastewater treatment plant effluent remain to be investigated.

  10. Presence of enteric viruses in source waters for drinking water production in The Netherlands.

    Science.gov (United States)

    Lodder, W J; van den Berg, H H J L; Rutjes, S A; de Roda Husman, A M

    2010-09-01

    The quality of drinking water in The Netherlands has to comply with the Dutch Drinking Water Directive: less than one infection in 10,000 persons per year may occur due to consumption of unboiled drinking water. Since virus concentrations in drinking waters may be below the detection limit but entail a public health risk, the infection risk from drinking water consumption requires the assessment of the virus concentrations in source waters and of the removal efficiency of treatment processes. In this study, samples of source waters were taken during 4 years of regular sampling (1999 to 2002), and enteroviruses, reoviruses, somatic phages, and F-specific phages were detected in 75% (range, 0.0033 to 5.2 PFU/liter), 83% (0.0030 to 5.9 PFU/liter), 100% (1.1 to 114,156 PFU/liter), and 97% (0.12 to 14,403 PFU/liter), respectively, of 75 tested source water samples originating from 10 locations for drinking water production. By endpoint dilution reverse transcription-PCR (RT-PCR), 45% of the tested source water samples were positive for norovirus RNA (0.22 to 177 PCR-detectable units [PDU]/liter), and 48% were positive for rotavirus RNA (0.65 to 2,249 PDU/liter). Multiple viruses were regularly detected in the source water samples. A significant correlation between the concentrations of the two phages and those of the enteroviruses could be demonstrated. The virus concentrations varied greatly between 10 tested locations, and a seasonal effect was observed. Peak concentrations of pathogenic viruses occur in source waters used for drinking water production. If seasonal and short-term fluctuations coincide with less efficient or failing treatment, an unacceptable public health risk from exposure to this drinking water may occur.

  11. Are NORMs Accumulated in Filters of Drinking Water Facilities?

    Science.gov (United States)

    Choung, S.; Shin, W.; Park, M.; Han, J. H.; Ryu, J. S.; Han, W. S.; Chang, B. U.

    2016-12-01

    Groundwater is used as raw water to produce mineral drinking water through filtering processes in bottled water facilities. Although natural occurring radioactive materials (NORMs) exist in groundwater, accumulation of NORMs were rarely studied due to their low concentrations in groundwater. The goal of this study is to evaluate potential accumulation of NORMs in filters used at the drinking water facilities. Raw water and treated water after each filtering step, bottled water, and used filters were collected from a total of 13 bottled water facilities to analyze major dissolved ions and NORMs. Additionally, surface radioactive dose rate were measured at individual filter housings. The measured concentrations of NORMs in raw and treated water were quite low. However, the surface radioactivity dose rates dramatically increased around filter housing located at very first step regardless of filter type (i.e., activated carbon or membrane filter) in 4 out of 6 facilities. Some used filters showed approximately 20 times greater contents of Pb-210 than the Korean regulation level of 1 Bq g-1. Also, the concentrations of uranium and thorium were detected up to 75 µg g-1filter and 2 µg g-1filter, respectively, in 4 water facilities. These results implies potential accumulation of NORMs in filters used at bottled water facilities. Therefore, the filters need to be monitored during manufacturing processes of bottled water, and may be properly managed after use.

  12. Purification of drinking water by low cost method in Ethiopia

    Science.gov (United States)

    Abatneh, Yasabie; Sahu, Omprakash; Yimer, Seid

    2014-12-01

    Nowadays, water treatment is a big issue in rural areas especially in African country. Due to lack of facilities available in those areas and the treatment are expensive. In this regard's an attempt has been made to find alternative natural way to treat the rural drinking water. The experiment trials were undertaken on the most promising plant extracts, namely: Moringa oleifera, Jatropha curcas and Guar gum. The extracts were used to treat contaminated water obtained from a number of wells. The results showed that the addition of M. oleifera can considerably improve the quality of drinking water. A 100 % improvement both in turbidity and reduction in Escherichia coli was noted for a number of the samples, together with significant improvements in colour.

  13. [Medical and environmental aspects of the drinking water supply crisis].

    Science.gov (United States)

    Él'piner, L I

    2013-01-01

    Modern data determining drinking water supply crisis in Russia have been considered. The probability of influence of drinking water quality used by population on current negative demographic indices was shown. The necessity of taking into account interests of public health care in the process of formation of water management decisions was grounded. To achieve this goal the application of medical ecological interdisciplinary approach was proposed Its use is mostly effective in construction of goal-directed medical ecological sections for territorial schemes of the rational use and protection of water resources. Stages of the elaboration of these sections, providing the basing of evaluation and prognostic medical and environmental constructions on similar engineering studies of related disciplinary areas (hydrological, hydrogeological, hydrobiological, hydrochemical, environmental, socio-economic, technical and technological) were determined.

  14. Bacteriological quality of bottled drinking water versus municipal tap water in Dharan municipality, Nepal.

    Science.gov (United States)

    Pant, Narayan Dutt; Poudyal, Nimesh; Bhattacharya, Shyamal Kumar

    2016-06-07

    Water-related diseases are of great concern in developing countries like Nepal. Every year, there are countless morbidity and mortality due to the consumption of unsafe drinking water. Recently, there have been increased uses of bottled drinking water in an assumption that the bottled water is safer than the tap water and its use will help to protect from water-related diseases. So, the main objective of this study was to analyze the bacteriological quality of bottled drinking water and that of municipal tap water. A total of 100 samples (76 tap water and 24 bottled water) were analyzed for bacteriological quality and pH. The methods used were spread plate method for total plate count (TPC) and membrane filter method for total coliform count (TCC), fecal coliform count (FCC), and fecal streptococcal count (FSC). pH meter was used for measuring pH. One hundred percent of the tap water samples and 87.5 % of the bottled water samples were found to be contaminated with heterotrophic bacteria. Of the tap water samples, 55.3 % were positive for total coliforms, compared with 25 % of the bottled water. No bottled water samples were positive for fecal coliforms and fecal streptococci, in contrast to 21.1 % and 14.5 % of the tap water samples being contaminated with fecal coliforms and fecal streptococci, respectively. One hundred percent of the tap water samples and 54.2 % of the bottled water samples had pH in the acceptable range. All of the municipal tap water samples and most of the bottled drinking water samples distributed in Dharan municipality were found to be contaminated with one or more than one type of indicator organisms. On the basis of our findings, we may conclude that comparatively, the bottled drinking water may have been safer (than tap water) to drink.

  15. Protection Planning for Rural Centralized Drinking Water Source Areas in Chongqing

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Protection planning is made for rural centralized drinking water source areas according to current situations of rural drinking water and existing problems of centralized drinking water source areas in Chongqing,and in combination with survey,analysis and evaluation of urban-rural drinking water source areas in whole city.There are engineering measures and non-engineering measures,to guarantee drinking water security of rural residents,improve rural ecological environment,realize sustainable use of water resource,and promote sustainable development of society.Engineering measures include conservation and protection of water resource,ecological restoration,isolation,and comprehensive control of pointsource and area-source pollution.Non-engineering measures include construction of monitoring system for drinking water source area,construction of security information system for rural centralized drinking water source area,and construction of emergency mechanism for water pollution accidents in rural water source areas.

  16. A Visual Insight into the Degradation of Metals Used in Drinking Water Distribution Systems Using AFM

    Science.gov (United States)

    Evaluating the fundamental corrosion and passivation of metallic copper used in drinking water distribution materials is important in understanding the overall mechanism of the corrosion process. Copper pipes are widely used for drinking water distribution systems and although it...

  17. Subsurface iron and arsenic removal for drinking water treatment in Bangladesh

    NARCIS (Netherlands)

    Van Halem, D.

    2011-01-01

    Arsenic contamination of shallow tube well drinking water is an urgent health problem in Bangladesh. Current arsenic mitigation solutions, including (household) arsenic removal options, do not always provide a sustainable alternative for safe drinking water. A novel technology, Subsurface Arsenic

  18. REMOVAL OF BERYLLIUM FROM DRINKING WATER BY CHEMICAL COAGULATION AND LIME SOFTENING

    Science.gov (United States)

    The effectiveness of conventional drinking water treatment and lime softening was evaluated for beryllium removal from two drinking water sources. ar test studies were conducted to determine how common coagulants (aluminum sulfate and ferric chloride and lime softening performed ...

  19. Radioactivity in drinking water supplies in Western Australia.

    Science.gov (United States)

    Walsh, M; Wallner, G; Jennings, P

    2014-04-01

    Radiochemical analysis was carried out on 52 drinking water samples taken from public outlets in the southwest of Western Australia. All samples were analysed for Ra-226, Ra-228 and Pb-210. Twenty five of the samples were also analysed for Po-210, and 23 were analysed for U-234 and U-238. Ra-228 was found in 45 samples and the activity ranged from Ra-226 was detected in all 52 samples and the activity ranged from 3.200 to 151.1 mBq L(-1). Po-210 was detected in 24 samples and the activity ranged from 0.000 to 114.2 mBq L(-1). These data were used to compute the annual radiation dose that persons of different age groups and also for pregnant and lactating females would receive from drinking this water. The estimated doses ranged from 0.001 to 2.375 mSv y(-1) with a mean annual dose of 0.167 mSv y(-1). The main contributing radionuclides to the annual dose were Ra-228, Po-210 and Ra-226. Of the 52 drinking water samples tested, 94% complied with the current Australian Drinking Water Guidelines, while 10% complied with the World Health Organization's radiological guidelines which many other countries use. It is likely that these results provide an overestimate of the compliance, due to limitations, in the sampling technique and resource constraints on the analysis. Because of the increasing reliance of the Western Australian community on groundwater for domestic and agricultural purposes, it is likely that the radiological content of the drinking water will increase in the future. Therefore there is a need for further monitoring and analysis in order to identify problem areas.

  20. Monochloramine Cometabolism by Nitrifying Biofilm Relevant ...

    Science.gov (United States)

    Recently, biological monochloramine removal (i.e., cometabolism) by a pure culture ammonia–oxidizing bacteria, Nitrosomonas europaea, and a nitrifying mixed–culture have been shown to increase monochloramine demand. Although important, these previous suspended culture batch kinetic experiments were not representative of drinking water distribution systems where bacteria grow predominantly as biofilm attached to pipe walls or sediments and physiological differences may exist between suspension and biofilm growth. Therefore, the current research was an important next step in extending the previous results to investigate monochloramine cometabolism by biofilm grown in annular reactors under drinking water relevant conditions. Estimated monochloramine cometabolism kinetics were similar to those of ammonia metabolism, and monochloramine cometabolism was a significant loss mechanism (25–40% of the observed monochloramine loss). These results demonstrated that monochloramine cometabolism occurred in drinking water relevant nitrifying biofilm; thus, cometabolism may be a significant contribution to monochloramine loss during nitrification episodes in distribution systems. Investigate whether or not nitrifying biofilm can biologically transform monochloramine under drinking water relevant conditions.