Science.gov

Sample records for addition water samples

  1. Effects of atmospheric precipitation additions on phytoplankton photosynthesis in Lake Michigan water samples

    SciTech Connect

    Parker, J.I.; Tisue, G.T.; Kennedy, C.W.; Seils, C.A.

    1981-01-01

    The effects of incremental additions (0.1 to 50% v/v) of atmospheric precipitation on phytoplankton photosynthesis (/sup 14/C uptake) were tested in Lake Michigan water samples. Wet deposition was used in experiments I, III, and IV, and a melted snow core was used in experiment II. Additions of precipitation significantly reduced photosynthesis in the first three experiments, starting at about the 5 to 15% treatment level. No significant difference occurred in experiment IV, but photosynthesis was greater than in the control samples and this precipitation sample appeared to stimulate primary productivity. Soluble reactive phosphate, nitrate, and ammonia levels in the precipitation samples exceeded the lake water averages by factors of 10, 2, and 50, respectively. Silicon levels in precipitation reduced pH very little and no consistent relationship was observed with reduced photosynthesis. Alkalinity was greatly reduced in the treated samples and special precautions were required in ce, Ti, Be, Co, Cu, Mo, Ni, P,f the Pd crystals of about 30 A. Possible mechanisms are discussed for isotope exchange in CO molecules in these catalysts and for the promoting effect of Pd on the activity of CuO.

  2. Percent recoveries of anthropogenic organic compounds with and without the addition of ascorbic acid to preserve finished-water samples containing free chlorine, 2004-10

    USGS Publications Warehouse

    Valder, Joshua F.; Delzer, Gregory C.; Bender, David A.; Price, Curtis V.

    2011-01-01

    This report presents finished-water matrix-spike recoveries of 270 anthropogenic organic compounds with and without the addition of ascorbic acid to preserve water samples containing free chlorine. Percent recoveries were calculated using analytical results from a study conducted during 2004-10 for the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS). The study was intended to characterize the effect of quenching on finished-water matrix-spike recoveries and to better understand the potential oxidation and transformation of 270 anthropogenic organic compounds. The anthropogenic organic compounds studied include those on analytical schedules 1433, 2003, 2033, 2060, 2020, and 4024 of the USGS National Water Quality Laboratory. Three types of samples were collected from 34 NAWQA locations across the Nation: (1) quenched finished-water samples (not spiked), (2) quenched finished-water matrix-spike samples, and (3) nonquenched finished-water matrix-spike samples. Percent recoveries of anthropogenic organic compounds in quenched and nonquenched finished-water matrix-spike samples are presented. Comparisons of percent recoveries between quenched and nonquenched spiked samples can be used to show how quenching affects finished-water samples. A maximum of 18 surface-water and 34 groundwater quenched finished-water matrix-spike samples paired with nonquenched finished-water matrix-spike samples were analyzed. Percent recoveries for the study are presented in two ways: (1) finished-water matrix-spike samples supplied by surface-water or groundwater, and (2) by use (or source) group category for surface-water and groundwater supplies. Graphical representations of percent recoveries for the quenched and nonquenched finished-water matrix-spike samples also are presented.

  3. Study Design and Percent Recoveries of Anthropogenic Organic Compounds With and Without the Addition of Ascorbic Acid to Preserve Water Samples Containing Free Chlorine, 2004-06

    USGS Publications Warehouse

    Valder, Joshua F.; Delzer, Gregory C.; Price, Curtis V.; Sandstrom, Mark W.

    2008-01-01

    The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS) began implementing Source Water-Quality Assessments (SWQAs) in 2002 that focus on characterizing the quality of source water and finished water of aquifers and major rivers used by some of the larger community water systems in the United States. As used for SWQA studies, source water is the raw (ambient) water collected at the supply well prior to water treatment (for ground water) or the raw (ambient) water collected from the river near the intake (for surface water). Finished water is the water that is treated, which typically involves, in part, the addition of chlorine or other disinfection chemicals to remove pathogens, and is ready to be delivered to consumers. Finished water is collected before the water enters the distribution system. This report describes the study design and percent recoveries of anthropogenic organic compounds (AOCs) with and without the addition of ascorbic acid to preserve water samples containing free chlorine. The percent recoveries were determined by using analytical results from a laboratory study conducted in 2004 by the USGS's National Water Quality Laboratory (NWQL) and from data collected during 2004-06 for a field study currently (2008) being conducted by the USGS's NAWQA Program. The laboratory study was designed to determine if preserving samples with ascorbic acid (quenching samples) adversely affects analytical performance under controlled conditions. During the laboratory study, eight samples of reagent water were spiked for each of five analytical schedules evaluated. Percent recoveries from these samples were then compared in two ways: (1) four quenched reagent spiked samples analyzed on day 0 were compared with four quenched reagent spiked samples analyzed on day 7 or 14, and (2) the combined eight quenched reagent spiked samples analyzed on day 0, 7, or 14 were compared with eight laboratory reagent spikes (LRSs). Percent

  4. Ionic liquids as mobile phase additives for the high-performance liquid chromatographic analysis of fluoroquinolone antibiotics in water samples.

    PubMed

    Herrera-Herrera, Antonio V; Hernández-Borges, Javier; Rodríguez-Delgado, Miguel Angel

    2008-12-01

    In this work, four ionic liquids differing in the length of the alkyl chain on the imidazolium cation and one ionic liquid containing tetraethylammonium, all with the same counterion, (i.e. 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIm-BF(4)), 1-butyl-3-methylimidazolium tetrafluoroborate (BMIm-BF(4)), 1-hexyl-3-methylimidazolium tetrafluoroborate (HMIm-BF(4)), 1-methyl-3-octylimidazolium tetrafluoroborate (MOIm-BF(4)), and tetraethylammonium tetrafluroborate (Et(4)N-BF(4))) were tested as mobile phase additives for HPLC separation of a group of seven basic fluoroquinolone (FQ) antibiotics for human and veterinary use (i.e. fleroxacin, ciprofloxacin, lomefloxacin, danofloxacin, enrofloxacin, sarafloxacin, and difloxacin) using a conventional reversed-phase Nova-Pak C(18) column. Fluorescence detection was used. Among the ionic liquids selected, use of BMIm-BF(4) enabled effective separation of these compounds with relatively low analysis time (14 min). The best separation was achieved by isocratic elution at 1 mL min(-1) with 5 mmol L(-1) BMIm-BF(4) and 10 mmol L(-1) ammonium acetate at pH 3.0 with 13% (v/v) acetonitrile. Limits of detection (LODs) for fluorescence detection were in the range 0.5-11 microg L(-1). The method was tested by analyzing several water samples after the optimization of a suitable solid-phase extraction (SPE) procedure using Oasis HLB cartridges. Mean recovery values were above 84% for all analytes with LODs in the range 1-29 ng L(-1). PMID:18854988

  5. GROUND WATER SAMPLING ISSUES

    EPA Science Inventory

    Obtaining representative ground water samples is important for site assessment and
    remedial performance monitoring objectives. Issues which must be considered prior to initiating a ground-water monitoring program include defining monitoring goals and objectives, sampling point...

  6. Enantioselective Michael Addition of Water

    PubMed Central

    Chen, Bi-Shuang; Resch, Verena; Otten, Linda G; Hanefeld, Ulf

    2015-01-01

    The enantioselective Michael addition using water as both nucleophile and solvent has to date proved beyond the ability of synthetic chemists. Herein, the direct, enantioselective Michael addition of water in water to prepare important β-hydroxy carbonyl compounds using whole cells of Rhodococcus strains is described. Good yields and excellent enantioselectivities were achieved with this method. Deuterium labeling studies demonstrate that a Michael hydratase catalyzes the water addition exclusively with anti-stereochemistry. PMID:25529526

  7. The role of methanol addition to water samples in reducing analyte adsorption and matrix effects in liquid chromatography-tandem mass spectrometry.

    PubMed

    Li, Wei; Liu, Yucan; Duan, Jinming; Saint, Christopher P; Mulcahy, Dennis

    2015-04-10

    Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis coupled simply with water filtering before injection has proven to be a simple, economic and time-saving method for analyzing trace-level organic pollutants in aqueous environments. However, the linearity, precision and detection limits of such methods for late-eluting analytes were found to be much poorer than for early-eluting ones due to adsorption of the analytes in the operating system, such as sample vial, flow path and sample loop, creating problems in quantitative analysis. Addition of methanol (MeOH) into water samples as a modifier was shown to be effective in alleviating or even eliminating the negative effect on signal intensity for the late-eluting analytes and at the same time being able to reduce certain matrix effects for real water samples. Based on the maximum detection signal intensity obtained on desorption of the analytes with MeOH addition, the ratio of the detection signal intensity without addition of MeOH to the maximum intensity can be used to evaluate the effectiveness of methanol addition. Accordingly, the values of <50%, 50-80%, 80-120% could be used to indicate strong, medium and no effects, respectively. Based on this concept, an external matrix-matched calibration method with the addition of MeOH has been successfully established for analyzing fifteen pesticides with diverse physico-chemical properties in surface and groundwater with good linearity (r(2): 0.9929-0.9996), precision (intra-day relative standard deviation (RSD): 1.4-10.7%, inter-day RSD: 1.5-9.4%), accuracy (76.9-126.7%) and low limits of detection (0.003-0.028μg/L). PMID:25748540

  8. Developing Water Sampling Standards

    ERIC Educational Resources Information Center

    Environmental Science and Technology, 1974

    1974-01-01

    Participants in the D-19 symposium on aquatic sampling and measurement for water pollution assessment were informed that determining the extent of waste water stream pollution is not a cut and dry procedure. Topics discussed include field sampling, representative sampling from storm sewers, suggested sampler features and application of improved…

  9. Water based drilling mud additive

    SciTech Connect

    McCrary, J.L.

    1983-12-13

    A water based fluid additive useful in drilling mud used during drilling of an oil or gas well is disclosed, produced by reacting water at temperatures between 210/sup 0/-280/sup 0/ F. with a mixture comprising in percent by weight: gilsonite 25-30%, tannin 7-15%, lignite 25-35%, sulfonating compound 15-25%, water soluble base compound 5-15%, methylene-yielding compound 1-5%, and then removing substantially all of the remaining water to produce a dried product.

  10. Water Sample Concentrator

    ScienceCinema

    Idaho National Laboratory

    2010-01-08

    Automated portable device that concentrates and packages a sample of suspected contaminated water for safe, efficient transport to a qualified analytical laboratory. This technology will help safeguard against pathogen contamination or chemical and biolog

  11. Water Sample Concentrator

    SciTech Connect

    Idaho National Laboratory

    2009-07-21

    Automated portable device that concentrates and packages a sample of suspected contaminated water for safe, efficient transport to a qualified analytical laboratory. This technology will help safeguard against pathogen contamination or chemical and biolog

  12. Water sample filtration unit

    USGS Publications Warehouse

    Skougstad, M.W.; Scarbro, G.F., Jr.

    1968-01-01

    A readily portable, all plastic, pressure filtration unit is described which greatly facilitates rapid micropore membrane field filtration of up to several liters of water with a minimum risk of inorganic chemical alteration or contamination of the sample. The unit accommodates standard 10.2-cm. (4-inch) diameter filters. The storage and carrying case serves as a convenient filter stand for both field and laboratory use.

  13. GROUND WATER SAMPLING FOR VOCS

    EPA Science Inventory

    Sampling protocol should be dictated by the sampling objective(s). It is important to obtain representative ground water samples, regardless of the sampling objective(s). Low-flow (minimum draw-down) purging and sampling techniques are best in most instances, particularly for VOC...

  14. 7 CFR 27.25 - Additional samples of cotton; drawing.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Additional samples of cotton; drawing. 27.25 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Inspection and Samples § 27.25 Additional samples of cotton; drawing. In addition to the samples hereinbefore...

  15. 7 CFR 27.25 - Additional samples of cotton; drawing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Additional samples of cotton; drawing. 27.25 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Inspection and Samples § 27.25 Additional samples of cotton; drawing. In addition to the samples hereinbefore...

  16. 7 CFR 27.25 - Additional samples of cotton; drawing.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Additional samples of cotton; drawing. 27.25 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Inspection and Samples § 27.25 Additional samples of cotton; drawing. In addition to the samples hereinbefore...

  17. 7 CFR 27.25 - Additional samples of cotton; drawing.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Additional samples of cotton; drawing. 27.25 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Inspection and Samples § 27.25 Additional samples of cotton; drawing. In addition to the samples hereinbefore...

  18. 7 CFR 27.25 - Additional samples of cotton; drawing.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Additional samples of cotton; drawing. 27.25 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Inspection and Samples § 27.25 Additional samples of cotton; drawing. In addition to the samples hereinbefore...

  19. 21 CFR 71.4 - Samples; additional information.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Samples; additional information. 71.4 Section 71.4 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL COLOR ADDITIVE PETITIONS General Provisions § 71.4 Samples; additional information. The Commissioner may request samples of the color additive,...

  20. 21 CFR 71.4 - Samples; additional information.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... samples of the color additive, articles used as components thereof, or of the food, drug, or cosmetic in... additive, or articles used as components thereof, or of the food, drug, or cosmetic in which the color... respect to the safety of the color additive or the physical or technical effect it produces. The date...

  1. 21 CFR 71.4 - Samples; additional information.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... samples of the color additive, articles used as components thereof, or of the food, drug, or cosmetic in... additive, or articles used as components thereof, or of the food, drug, or cosmetic in which the color... respect to the safety of the color additive or the physical or technical effect it produces. The date...

  2. Estimating soil water retention using soil component additivity model

    NASA Astrophysics Data System (ADS)

    Zeiliger, A.; Ermolaeva, O.; Semenov, V.

    2009-04-01

    Soil water retention is a major soil hydraulic property that governs soil functioning in ecosystems and greatly affects soil management. Data on soil water retention are used in research and applications in hydrology, agronomy, meteorology, ecology, environmental protection, and many other soil-related fields. Soil organic matter content and composition affect both soil structure and adsorption properties; therefore water retention may be affected by changes in soil organic matter that occur because of both climate change and modifications of management practices. Thus, effects of organic matter on soil water retention should be understood and quantified. Measurement of soil water retention is relatively time-consuming, and become impractical when soil hydrologic estimates are needed for large areas. One approach to soil water retention estimation from readily available data is based on the hypothesis that soil water retention may be estimated as an additive function obtained by summing up water retention of pore subspaces associated with soil textural and/or structural components and organic matter. The additivity model and was tested with 550 soil samples from the international database UNSODA and 2667 soil samples from the European database HYPRES containing all textural soil classes after USDA soil texture classification. The root mean square errors (RMSEs) of the volumetric water content estimates for UNSODA vary from 0.021 m3m-3 for coarse sandy loam to 0.075 m3m-3 for sandy clay. Obtained RMSEs are at the lower end of the RMSE range for regression-based water retention estimates found in literature. Including retention estimates of organic matter significantly improved RMSEs. The attained accuracy warrants testing the 'additivity' model with additional soil data and improving this model to accommodate various types of soil structure. Keywords: soil water retention, soil components, additive model, soil texture, organic matter.

  3. Water addition, evaporation and water holding capacity of poultry litter.

    PubMed

    Dunlop, Mark W; Blackall, Patrick J; Stuetz, Richard M

    2015-12-15

    Litter moisture content has been related to ammonia, dust and odour emissions as well as bird health and welfare. Improved understanding of the water holding properties of poultry litter as well as water additions to litter and evaporation from litter will contribute to improved litter moisture management during the meat chicken grow-out. The purpose of this paper is to demonstrate how management and environmental conditions over the course of a grow-out affect the volume of water A) applied to litter, B) able to be stored in litter, and C) evaporated from litter on a daily basis. The same unit of measurement has been used to enable direct comparison-litres of water per square metre of poultry shed floor area, L/m(2), assuming a litter depth of 5cm. An equation was developed to estimate the amount of water added to litter from bird excretion and drinking spillage, which are sources of regular water application to the litter. Using this equation showed that water applied to litter from these sources changes over the course of a grow-out, and can be as much as 3.2L/m(2)/day. Over a 56day grow-out, the total quantity of water added to the litter was estimated to be 104L/m(2). Litter porosity, water holding capacity and water evaporation rates from litter were measured experimentally. Litter porosity decreased and water holding capacity increased over the course of a grow-out due to manure addition. Water evaporation rates at 25°C and 50% relative humidity ranged from 0.5 to 10L/m(2)/day. Evaporation rates increased with litter moisture content and air speed. Maintaining dry litter at the peak of a grow-out is likely to be challenging because evaporation rates from dry litter may be insufficient to remove the quantity of water added to the litter on a daily basis. PMID:26367067

  4. ADVANCES IN GROUND WATER SAMPLING PROCEDURES

    EPA Science Inventory

    Obtaining representative ground water samples is important for site assessment and remedial performance monitoring objectives. Issues which must be considered prior to initiating a ground-water monitoring program include defining monitoring goals and objectives, sampling point...

  5. Magnificent Ground Water Connection. [Sample Activities].

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Washington, DC.

    Water conservation and usage is an important concept in science. This document, geared specifically to New England, provides many activities for protecting and discussing ground water situations. Sample activities for grades K-6 include: (1) All the Water in the World; (2) The Case of the Disappearing Water; (3) Deep Subjects--Wells and Ground…

  6. THE FATE OF FLUOROSILICATE DRINKING WATER ADDITIVES

    EPA Science Inventory

    Periodically, the EPA reexamines its information on regulated drinking water contaminants to deterime if further study is required. Fluoride is one such contaminant undergoing review. The chemical literature indicates that some deficiencies exist in our understanding of the spe...

  7. GROUND WATER SAMPLING FOR METALS

    EPA Science Inventory

    The collection of groundwater samples for metals, including metalloids such as arsenic and selenium, is primarily complicated by the fact that many of the target metal contaminants are also part of the immobile geologic matrix through which groundwater flows. istorically, filtrat...

  8. Handbook for sampling and sample preservation of water and wastewater. Report for 1978-1981

    SciTech Connect

    Berg, E.L.

    1992-05-01

    Personnel from Armstrong Laboratory (AL) Water Quality Function found this EPA publication to be an excellent source for sampling and sample preservation of water and wastewater. The information found in this document should assist base Bioenvironmental Engineers in all aspects of water sampling. Sampling, Flow, Measurements, Wastewater sampling, Sediment sampling, Statistical approach to sampling, Ground water sampling, Drinking water Sampling, Sludge sampling.

  9. Chapter A5. Processing of Water Samples

    USGS Publications Warehouse

    Wilde, Franceska D., (Edited By); Radtke, Dean B.; Gibs, Jacob; Iwatsubo, Rick T.

    1999-01-01

    The National Field Manual for the Collection of Water-Quality Data (National Field Manual) describes protocols and provides guidelines for U.S. Geological Survey (USGS) personnel who collect data used to assess the quality of the Nation's surface-water and ground-water resources. This chapter addresses methods to be used in processing water samples to be analyzed for inorganic and organic chemical substances, including the bottling of composite, pumped, and bailed samples and subsamples; sample filtration; solid-phase extraction for pesticide analyses; sample preservation; and sample handling and shipping. Each chapter of the National Field Manual is published separately and revised periodically. Newly published and revised chapters will be announced on the USGS Home Page on the World Wide Web under 'New Publications of the U.S. Geological Survey.' The URL for this page is http:/ /water.usgs.gov/lookup/get?newpubs.

  10. Determination of dissolved aluminum in water samples

    USGS Publications Warehouse

    Afifi, A.A.

    1983-01-01

    A technique has been modified for determination of a wide range of concentrations of dissolved aluminum (Al) in water and has been tested. In this technique, aluminum is complexed with 8-hydroxyquinoline at pH 8.3 to minimize interferences, then extracted with methyl isobutyl ketone (MIBK). The extract is analyzed colorimetrically at 395 nm. This technique is used to analyze two forms of monomeric Al, nonlabile (organic complexes) and labile (free, Al, Al sulfate, fluoride and hydroxide complexes). A detection limit 2 ug/L is possible with 25-ml samples and 10-ml extracts. The detection limit can be decreased by increasing the volume of the sample and (or) decreasing the volume of the methyl isobutyl ketone extract. The analytical uncertainty of this method is approximately + or - 5 percent. The standard addition technique provides a recovery test for this technique and ensures precision in samples of low Al concentrations. The average percentage recovery of the added Al plus the amount originally present was 99 percent. Data obtained from analyses of filtered standard solutions indicated that Al is adsorbed on various types of filters. However, the relationship between Al concentrations and adsorption remains linear. A test on standard solutions also indicated that Al is not adsorbed on nitric acid-washed polyethylene and polypropylene bottle wells. (USGS)

  11. Automated storm water sampling on small watersheds

    USGS Publications Warehouse

    Harmel, R.D.; King, K.W.; Slade, R.M.

    2003-01-01

    Few guidelines are currently available to assist in designing appropriate automated storm water sampling strategies for small watersheds. Therefore, guidance is needed to develop strategies that achieve an appropriate balance between accurate characterization of storm water quality and loads and limitations of budget, equipment, and personnel. In this article, we explore the important sampling strategy components (minimum flow threshold, sampling interval, and discrete versus composite sampling) and project-specific considerations (sampling goal, sampling and analysis resources, and watershed characteristics) based on personal experiences and pertinent field and analytical studies. These components and considerations are important in achieving the balance between sampling goals and limitations because they determine how and when samples are taken and the potential sampling error. Several general recommendations are made, including: setting low minimum flow thresholds, using flow-interval or variable time-interval sampling, and using composite sampling to limit the number of samples collected. Guidelines are presented to aid in selection of an appropriate sampling strategy based on user's project-specific considerations. Our experiences suggest these recommendations should allow implementation of a successful sampling strategy for most small watershed sampling projects with common sampling goals.

  12. Chapter A4. Collection of Water Samples

    USGS Publications Warehouse

    Wilde, Franceska D., (Edited By)

    1999-01-01

    The National Field Manual for the Collection of Water-Quality Data (National Field Manual) describes protocols and provides guidelines for U.S. Geological Survey (USGS) personnel who collect data that are used to assess the quality of the Nation's surface-water and ground-water resources. This chapter addresses preparations and appropriate methods for the collection of surface-water, groundwater, and associated quality-control samples. Among the topics covered are considerations and procedures to prevent sample contamination; establishing site files; instructions for collecting depth-integrated isokinetic and nonisokinetic samples at flowing- and still-water sites; and guidelines for collecting formation water from wells having various types of construction and hydraulic and aquifer characteristics.

  13. SUPERFUND GROUND WATER ISSUE: GROUND WATER SAMPLING FOR METALS ANALYSES

    EPA Science Inventory

    Filtration of ground-water samples for metals analysis is an issue identified by the Forum as a concern of Superfund decision-makers. Inconsistency in EPA Syperfund cleanup pracices occurs where one EPA Region implements a remedial action based on unfiltered ground-water samples,...

  14. 10. Water treatment plant, view to S. 1965 addition is ...

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

    10. Water treatment plant, view to S. 1965 addition is in the foreground - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

  15. Chapter A1. Preparations for Water Sampling

    USGS Publications Warehouse

    Wilde, Franceska D.; Radtke, Dean B.; Gibs, Jacob; Iwatsubo, Rick T.

    1998-01-01

    The National Field Manual for the Collection of Water-Quality Data (National Field Manual) provides guidelines and standard procedures for U.S. Geological Survey (USGS) personnel who collect data used to assess the quality of the Nation's surface-water and ground-water resources. This chapter addresses field-trip preparations, including selection of sample-collection sites for studies of surface-water quality, site reconnaissance and well selection for studies of groundwater quality, and the establishment of electronic files and field files and folders for a sampling site. Each chapter of the National Field Manual is published separately and revised periodically. Newly published and revised chapters are posted on the World Wide Web on the USGS page 'National Field Manual for the Collection of Water-Quality Data.' The URL for this page is http://pubs.water.usgs.gov/twri9A/ (accessed Jan. 31, 2005).

  16. SAMPLING DESIGN FOR ASSESSING RECREATIONAL WATER QUALITY

    EPA Science Inventory

    Current U.S. EPA guidelines for monitoring recreatoinal water quality refer to the geometric mean density of indicator organisms, enterococci and E. coli in marine and fresh water, respectively, from at least five samples collected over a four-week period. In order to expand thi...

  17. The effect of switchable water additives on clay settling.

    PubMed

    Chen, Chien-Shun; Lau, Ying Yin; Mercer, Sean M; Robert, Tobias; Horton, J Hugh; Jessop, Philip G

    2013-01-01

    The recycling of process water from strip mining extractions is a very relevant task both industrially and environmentally. The sedimentation of fine tailings during such processes, however, can often require long periods of time and/or the addition of flocculants which make later water recycling difficult. We propose the use of switchable water additives as reversible flocculants for clay/water suspensions. Switchable water additives are compounds such as diamines that make it possible to reversibly control the ionic strength of an aqueous solution. Addition of CO(2) to such an aqueous solution causes the ionic strength to rise dramatically, and the change is reversed upon removal of the CO(2). These additives, while in the presence of CO(2), promote the aggregation of clay tailings, reduce settling times, and greatly increase the clarity of the liberated water. The removal of CO(2) from the liberated water regenerates a low ionic strength solution that does not promote clay aggregation and settling until CO(2) is added again. Such reversible behavior would be useful in applications such as oil sands separations in which the recycled water must not promote aggregation. When added to kaolinite and montmorillonite clay suspensions, switchable water provided process waters of lower turbidity than those additives from inorganic salts or by CO(2)-treatment alone. When recollected, the switchable water supernatant was shown to be recyclable over three cycles for enhanced settling of kaolinite. PMID:22945593

  18. 52 additional reference population samples for the 55 AISNP panel.

    PubMed

    Pakstis, Andrew J; Haigh, Eva; Cherni, Lotfi; ElGaaied, Amel Ben Ammar; Barton, Alison; Evsanaa, Baigalmaa; Togtokh, Ariunaa; Brissenden, Jane; Roscoe, Janet; Bulbul, Ozlem; Filoglu, Gonul; Gurkan, Cemal; Meiklejohn, Kelly A; Robertson, James M; Li, Cai-Xia; Wei, Yi-Liang; Li, Hui; Soundararajan, Usha; Rajeevan, Haseena; Kidd, Judith R; Kidd, Kenneth K

    2015-11-01

    Ancestry inference for a person using a panel of SNPs depends on the variation of frequencies of those SNPs around the world and the amount of reference data available for calculation/comparison. The Kidd Lab panel of 55 AISNPs has been incorporated in commercial kits by both Life Technologies and Illumina for massively parallel sequencing. Therefore, a larger set of reference populations will be useful for researchers using those kits. We have added reference population allele frequencies for 52 population samples to the 73 previously entered so that there are now allele frequencies publicly available in ALFRED and FROG-kb for a total of 125 population samples. PMID:26355664

  19. Stereochemistry of enzymatic water addition to C=C bonds.

    PubMed

    Chen, Bi-Shuang; Otten, Linda G; Hanefeld, Ulf

    2015-01-01

    Water addition to carbon-carbon double bonds using hydratases is attracting great interest in biochemistry. Most of the known hydratases are involved in primary metabolism and to a lesser extent in secondary metabolism. New hydratases have recently been added to the toolbox, both from natural sources or artificial metalloenzymes. In order to comprehensively understand how the hydratases are able to catalyse the water addition to carbon-carbon double bonds, this review will highlight the mechanistic and stereochemical studies of the enzymatic water addition to carbon-carbon double bonds, focusing on the syn/anti-addition and stereochemistry of the reaction. PMID:25640045

  20. CONSTANT VOLUME SAMPLING SYSTEM WATER CONDENSATION

    EPA Science Inventory

    Combustion of organic motor vehicle fuels produces carbon dioxide and water (H2O) vapor (and also products of incomplete combustion, e.g. hydrocarbons and carbon monoxide, at lower concentrations). he Constant Volume Sampling (CVS) system, commonly used to condition auto exhaust ...

  1. Fire extinct experiments with water mist by adding additives

    NASA Astrophysics Data System (ADS)

    Yang, Lijun; Zhao, Jianbo

    2011-12-01

    The effects of fire extinguishment with water mist by adding different additives were studied. Tens of chemical substances (including alkali metal salt, dilution agent and surface active agent) were selected as additives due to their different extinct mechanisms. At first the performance of fire extinguishment with single additive was studied, then the effects of the same kinds of chemical substances under the same mass fraction were compared to study their influences on the fire extinguishment factors, including extinct time, fire temperature and oxygen concentration from which the fire extinct mechanism with additives could be concluded. Based on this the experiments were conducted to study the cooperate effect of the complexity of different additives. It indicated the relations between different firefighting mechanisms and different additives were competitive. From a large number of experiments the extinct mechanism with water mist by adding additives was concluded and an optimal compounding additive was selected.

  2. Reliability of chemical analyses of water samples

    SciTech Connect

    Beardon, R.

    1989-11-01

    Ground-water quality investigations require reliable chemical analyses of water samples. Unfortunately, laboratory analytical results are often unreliable. The Uranium Mill Tailings Remedial Action (UMTRA) Project`s solution to this problem was to establish a two phase quality assurance program for the analysis of water samples. In the first phase, eight laboratories analyzed three solutions of known composition. The analytical accuracy of each laboratory was ranked and three laboratories were awarded contracts. The second phase consists of on-going monitoring of the reliability of the selected laboratories. The following conclusions are based on two years experience with the UMTRA Project`s Quality Assurance Program. The reliability of laboratory analyses should not be taken for granted. Analytical reliability may be independent of the prices charged by laboratories. Quality assurance programs benefit both the customer and the laboratory.

  3. A new device for collecting time-integrated water samples from springs and surface water bodies

    USGS Publications Warehouse

    Panno, S.V.; Krapac, I.G.; Keefer, D.A.

    1998-01-01

    A new device termed the 'seepage sampler' was developed to collect representative water samples from springs, streams, and other surface-water bodies. The sampler collects composite, time-integrated water samples over short (hours) or extended (weeks) periods without causing significant changes to the chemical composition of the samples. The water sample within the sampler remains at the ambient temperature of the water body and does not need to be cooled. Seepage samplers are inexpensive to construct and easy to use. A sampling program of numerous springs and/or streams can be designed at a relatively low cost through the use of these samplers. Transient solutes migrating through such flow systems, potentially unnoticed by periodic sampling, may be detected. In addition, the mass loading of solutes (e.g., agrichemicals) may be determined when seepage samplers are used in conjunction with discharge measurements.

  4. Reduction of hexavalent chromium in water samples acidified for preservation

    USGS Publications Warehouse

    Stollenwerk, K.G.; Grove, D.B.

    1985-01-01

    Reduction of hexavalent chromium, Cr(VI), in water samples, preserved by standard techniques, was investigated. The standard preservation technique for water samples that are to be analyzed for Cr(VI) consists of filtration through a 0.45-??m membrane, acidification to a pH < 2, and storage in plastic bottles. Batch experiments were conducted to evaluate the effect of H+ concentration, NO2, temperature, and dissolved organic carbon (DOC) on the reduction of Cr(VI) to Cr(III). The rate of reduction of Cr(VI) to Cr(III) increased with increasing NO2, DOC, H+, and temperature. Reduction of Cr(VI) by organic matter occurred in some samples even though the samples were unacidified. Reduction of Cr(VI) is inhibited to an extent by storing the sample at 4??C. Stability of Cr(VI) in water is variable and depends on the other constituents present in the sample. Water samples collected for the determination of Cr(VI) should be filtered (0.45-??m membrane), refrigerated, and analyzed as quickly as possible. Water samples should not be acidified. Measurement of total Cr in addition to Cr(VI) can serve as a check for Cr(VI) reduction. If total Cr is greater than Cr(VI), the possibility that Cr(VI) reduction has occurred needs to be considered.The rate of reduction of Cr(VI) to Cr(III) increased with increasing NO//2, DOC, H** plus , and temperature. Reduction of Cr(VI) by organic matter occurred in some samples even though the samples were unacidified. Reduction of Cr(VI) is inhibited to an extent by storing the sample at 4 degree C. Stability of Cr(VI) in water is variable and depends on the other constituents present in the sample. Water samples collected for the determination of Cr(VI) should be filtered (0. 45- mu m membrane), refrigerated, and analyzed as quickly as possible. Water samples should not be acidified. Measurement of total Cr in addition to Cr(VI) can serve as a check for Cr(VI) reduction. If total Cr is greater than Cr(VI), the possibility that Cr

  5. [Utility of noise addition image made by using water phantom and image addition and subtraction software].

    PubMed

    Watanabe, Ryo; Ogawa, Masato; Mituzono, Hiroki; Aoki, Takahiro; Hayano, Mizuho; Watanabe, Yuka

    2010-08-20

    In optimizing exposures, it is very important to evaluate the impact of image noise on image quality. To realize this, there is a need to evaluate how much image noise will make the subject disease invisible. But generally it is very difficult to shoot images of different quality in a clinical examination. Thus, a method to create a noise addition image by adding the image noise to raw data has been reported. However, this approach requires a special system, so it is difficult to implement in many facilities. We have invented a method to easily create a noise addition image by using the water phantom and image add-subtract software that accompanies the device. To create a noise addition image, first we made a noise image by subtracting the water phantom with different SD. A noise addition image was then created by adding the noise image to the original image. By using this method, a simulation image with intergraded SD can be created from the original. Moreover, the noise frequency component of the created noise addition image is as same as the real image. Thus, the relationship of image quality to SD in the clinical image can be evaluated. Although this method is an easy method of LDSI creation on image data, a noise addition image can be easily created by using image addition and subtraction software and water phantom, and this can be implemented in many facilities. PMID:20953102

  6. Ground Water Sampling at ISCO Sites - Residual Oxidant Impact on Sample Quality and Sample Preservation Guideline

    EPA Science Inventory

    In-situ chemical oxidation (ISCO) involves the delivery of a chemical oxidant into the subsurface where oxidative reactions transform ground water contaminants into less toxic or harmless byproducts. Due to oxidant persistence, ground water samples collected at hazardous waste si...

  7. Microbial sampling variables and recreational water quality standards.

    PubMed Central

    Brenniman, G R; Rosenberg, S H; Northrop, R L

    1981-01-01

    A study was conducted at two beaches on Lake Erie to evaluate the water sampling design for the collection of several microbiological indicator organisms in relation to day, time, and location of collection. The concentrations of these organisms were generally found to vary significantly (P less than 0.05) by the specific time of day and day of weekend that collection took place. However, the concentrations of these organisms did not vary significantly (P greater than 0.05) at various locations in the bathing area. Future studies investigating the health effects of recreational water as related to microbiological variables should be designed to collect water samples at the specific time of day and day of weekend that an individual was exposed. In addition, sampling at various locations in the bathing area should probably be considered for those beaches having poor dispersion of fecal waste sources. PMID:6781366

  8. Construction Site Storm Water Sampling California's New Construction Sampling and Analysis Requirements

    SciTech Connect

    Forrest, C.L.; Mathews, S.

    2002-04-02

    The California State Water Resources Control Board (State Board) originally issued a National Pollutant Discharge System (NPDES) permit for storm water discharges associated with construction activities in 1992. This NPDES permit was issued as a general permit, applicable throughout the state (with certain exceptions). The general construction permit was made site-specific by a discharger-developed Storm Water Pollution Prevention Plan (SWPPP). As with most NPDES construction storm water permits, monitoring requirements were limited to inspections. Sampling and analysis of discharges was not specifically required, but a Regional Water Quality Control Board (Regional Board) could require additional monitoring. In 1999, the State -Board revised and reissued its construction general permit. While the 1999 permit significantly enhanced the erosion and sediment control descriptions and requirements, and expanded the inspection program, sampling and analysis was still not required. Environmental advocacy groups took exception to the absence of sampling requirements and sought relief in court to add sampling and analysis. In 2001, the State Board in response to the court order adopted a resolution requiring sampling and analysis of construction site runoff under two conditions. Turbidity and/or sediment sampling is required when construction site runoff enters water bodies determined to impaired for sediment or turbidity. Sampling for non-visible pollutants is required when construction operations expose materials to storm water. Sampling construction site runoff is relatively new concept for NPDES permits. Only a few permits throughout the country require sampling and analysis for sediment-related pollutants, and California is one of the only permitting entities to require sampling for non-visible pollutants in construction site runoff. The added complexity of sampling runoff requires construction operators and erosion and sediment control professionals to expand their

  9. Continuous water sampling and water analysis in estuaries

    USGS Publications Warehouse

    Schemel, L.E.; Dedini, L.A.

    1982-01-01

    Salinity, temperature, light transmission, oxygen saturation, pH, pCO2, chlorophyll a fluorescence, and the concentrations of nitrate, nitrite, dissolved silica, orthophosphate, and ammonia are continuously measured with a system designed primarily for estuarine studies. Near-surface water (2-m depth) is sampled continuously while the vessel is underway; on station, water to depths of 100 m is sampled with a submersible pump. The system is comprised of commercially available instruments, equipment, and components, and of specialized items designed and fabricated by the authors. Data are read from digital displays, analog strip-chart recorders, and a teletype printout, and can be logged in disc storage for subsequent plotting. Data records made in San Francisco Bay illustrate physical, biological, and chemical estuarine processes, such as mixing and phytoplankton net production. The system resolves large- and small-scale events, which contributes to its reliability and usefulness.

  10. AMES SALMONELLA MUTAGENICITY ASSAY PROCEDURE FOR WATER SAMPLES

    EPA Science Inventory

    This report describes methods for water and wastewater sample collection and processing for the Ames Salmonella mutagenicity assay. uidelines are provided for sampling equipment, composite sample collection, storage, and handling; sample filtration and extraction and concentratio...

  11. 21 CFR 173.310 - Boiler water additives.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...), pp. 744-745, which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are available from the National Academy Press, 2101... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Boiler water additives. 173.310 Section...

  12. 21 CFR 173.310 - Boiler water additives.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...), pp. 744-745, which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are available from the National Academy Press, 2101... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Boiler water additives. 173.310 Section...

  13. 21 CFR 173.310 - Boiler water additives.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...), pp. 744-745, which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are available from the National Academy Press, 2101... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Boiler water additives. 173.310 Section...

  14. 21 CFR 173.310 - Boiler water additives.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...), pp. 744-745, which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are available from the National Academy Press, 2101... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Boiler water additives. 173.310 Section...

  15. HANDBOOK FOR SAMPLING AND SAMPLE PRESERVATION OF WATER AND WASTEWATER

    EPA Science Inventory

    The four basic factors which affect the quality of environmental data are Sample Collection, Preservation, Analyses, and Data Recording. Improper action in any one of these areas will result in poor data from which poor judgements are certain. Therefore, this research program was...

  16. 49 CFR 199.111 - Retention of samples and additional testing.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Retention of samples and additional testing. 199.111 Section 199.111 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE... SAFETY DRUG AND ALCOHOL TESTING Drug Testing § 199.111 Retention of samples and additional testing....

  17. Chapter 5: Surface water quality sampling in streams and canals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surface water sampling and water quality assessments have greatly evolved in the United States since the 1970s establishment of the Clean Water Act. Traditionally, water quality referred to only the chemical characteristics of the water and its toxicological properties related to drinking water or ...

  18. UMTRA project water sampling and analysis plan, Maybell, Colorado

    SciTech Connect

    Not Available

    1994-06-01

    This water sampling and analysis plan (WSAP) describes planned water sampling activities and provides the regulatory and technical basis for ground water sampling in 1994 at the US Department of Energy`s (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project site in Maybell, Colorado. The WSAP identifies and justifies sampling locations, analytical parameters, and sampling frequencies at the site. The ground water data will be used for site characterization and risk assessment. The regulatory basis for the ground water and surface water monitoring activities is derived from the EPA regulations in 40 CFR Part 192 (1993) and the proposed EPA standards of 1987 (52 FR 36000). Sampling procedures are guided by the UMTRA Project standard operating procedures (SOP) (JEG, n.d.), the Technical Approach Document (TAD) (DOE, 1989), and the most effective technical approach for the site. This WSAP also includes a summary and the results of water sampling activities from 1989 through 1992 (no sampling was performed in 1993).

  19. UMTRA water sampling and analysis plan, Green River, Utah

    SciTech Connect

    Papusch, R.

    1993-12-01

    The purpose of this water sampling and analysis plan (WSAP) is to provide a basis for groundwater and surface water sampling at the Green River Uranium Mill Tailing Remedial Action (UMTRA) Project site. This WSAP identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequency for the monitoring locations.

  20. GROUND WATER SAMPLING USING LOW-FLOW TECHNIQUES

    EPA Science Inventory

    Obtaining representative ground water samples is important for site assessment and remedial performance monitoring objectives. The sampling device or method used to collect samples from monitoring or compliance well can significantly impact data quality and reliability. Low-flo...

  1. ACQUISITION OF REPRESENTATIVE GROUND WATER QUALITY SAMPLES FOR METALS

    EPA Science Inventory

    R.S. Kerr Environmental Research Laboratory (RSKERL) personnel have evaluated sampling procedures for the collection of representative, accurate, and reproducible ground water quality samples for metals for the past four years. Intensive sampling research at three different field...

  2. Silicone rubber selection for passive sampling of pesticides in water.

    PubMed

    Martin, A; Margoum, C; Randon, J; Coquery, M

    2016-11-01

    Silicone rubber can extract organic compounds with a broad range of polarities (logKow>2-3) from aqueous samples. Such compounds include substances of major concern in the protection of aquatic ecosystems and human health, e.g. pesticides. Silicone rubbers (SRs) with various characteristics have been successfully used in sorptive methods for water sample extraction in the laboratory (SPME, SBSE), and for passive sampling in aquatic environments. However, only few studies have evaluated variability in organic compound sorption due to the origin of SRs, particularly for pesticides. The aim of this study was to select an SR for the extraction of pesticides from water samples by passive sampling. To this end we measured the impact of seven SR formulations on sorption capacity, defined by the partition coefficient (Ksw). Kinetic experiments and sorption isotherms were performed to determine extraction recovery as a selection criterion for SRs, and pesticide partition coefficients. Very large differences in affinity for pesticides were found between two kinds of SRs: "Polymerized SR kits" and "Manufactured SRs". One SR was chosen among the "Manufactured SRs", and the Ksw values of 21 pesticides were determined, filling a gap in the literature (1.50additional economic and technical factors, we suggest using SR from Goodfellow in future work to reduce the variability of Ksw literature values. PMID:27591618

  3. Dynamic Response of Forest Litter and Mineral Soil to Pulsed Water Additions

    NASA Astrophysics Data System (ADS)

    Boot, C. M.; Schaeffer, S. M.; Carbone, M. S.; Still, C. J.; Schimel, J.

    2010-12-01

    Quantifying microbial responses to drought and moisture pulses are essential to understanding terrestrial C cycling in a changing climate. Using laboratory incubations we sought to determine if water added in multiple consecutive pulses to pine forest litter and mineral soil resulted in different C dynamics than water added in a single event. Soils were collected from two sites on Santa Cruz Island located in Channel Islands National Park 40 km southwest of Santa Barbara, CA. Both sites are dominated by Bishop pine (Pinus muricata) mixed with chaparral shrubs, with a ~3-10 cm thick litter layer. The sites differ, however, in the frequency and amount of precipitation received. Following water additions as either one or three pulses (equal total volume) we measured respiration, dissolved organic carbon (DOC) and microbial biomass carbon (MBC) over twenty-two days after the first water addition. Three days after the initial water addition in the litter samples the DOC and MBC for both treatments were not different; however, the temporal dynamics varied by site with the high precipitation site responding more quickly and with a higher magnitude than the low precipitation site. In both the litter and mineral soil respiration rate correlated with soil moisture (r2=0.91 and 0.84 respectively). Our results suggest that the water history and other site-specific characteristics were more important in the response to pulsed water additions than how the water was introduced to the system.

  4. Methods for collection and analysis of water samples

    USGS Publications Warehouse

    Rainwater, Frank Hays; Thatcher, Leland Lincoln

    1960-01-01

    This manual contains methods used by the U.S. Geological Survey to collect, preserve, and analyze water samples. Throughout, the emphasis is on obtaining analytical results that accurately describe the chemical composition of the water in situ. Among the topics discussed are selection of sampling sites, frequency of sampling, field equipment, preservatives and fixatives, analytical techniques of water analysis, and instruments. Seventy-seven laboratory and field procedures are given for determining fifty-three water properties.

  5. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  6. Study of Cloud Water Samples Collected over Northern Poland.

    PubMed

    Polkowska, Ż; Błaś, M; Lech, D; Namieśnik, J

    2014-01-01

    The paper gives the results of the first studies on the chemistry of cloud water collected during 3 mo (Aug.-Oct. 2010) in the free atmosphere over the area to the south of the Tri-City (Gdansk-Sopot-Gdynia) conurbation on the Gulf of Gdansk, Poland. Taken from cumulus, stratus, and stratocumulus clouds by means of an aircraft-mounted collector, the water samples were analyzed for the following contaminants: anions (chlorides, fluorides, nitrates, sulfates, and phosphates), cations (lithium, sodium, potassium, ammonium, calcium, and magnesium), and trace metals. In addition, pH values were measured, and the type and composition of suspended particulate matter was determined. We discuss the relationship between the concentration of inorganic ions and the type of cloud from which water was sampled. The chemistry is also likely related to the circulation pattern and inflow of clean air masses from the Baltic Sea. Moreover, a relationship was found between the composition of the samples examined and the location of pollutant emission sources. PMID:25602567

  7. UMTRA Project water sampling and analysis plan, Slick Rock, Colorado

    SciTech Connect

    Not Available

    1994-08-01

    This water sampling and analysis plan (WSAP) provides the regulatory and technical basis for ground water and surface water sampling at the Uranium Mill Tailings Remedial Action (UMTRA) Project Union Carbide (UC) and North Continent (NC) processing sites and the proposed Burro Canyon disposal site near Slick Rock, Colorado for the upcoming year. It identifies and justifies the sampling locations, analytical parameters, and sampling frequencies. The WSAP bridges water quality characterization and data collection objectives for the surface remediation program (Subpart A) and the ground water compliance program (Subpart B) identified in 40 CFR Part 192 (1994).

  8. Nano-porous pottery using calcined waste sediment from tap water production as an additive.

    PubMed

    Sangsuk, Supin; Khunthon, Srichalai; Nilpairach, Siriphan

    2010-10-01

    A suspension of sediment from a lagoon in a tap water production plant was collected for this experiment. The suspension was spray dried and calcined at 700 °C for 1 h. After calcining, 30 wt.% of the sediment were mixed with pottery clay. Samples with and without calcined sediment were sintered at 900, 1000 and 1100 °C. The results show that calcined sediment can be used as an additive in pottery clay. The samples with calcined sediment show higher porosity, water absorption and flexural strength, especially for 900 and 1000 °C. At 900 °C, samples with calcined sediment show a porosity of 50% with an average pore size of 68 nm, water absorption of 31% and flexural strength of 12.61 MPa. PMID:19942644

  9. Sampling trace organic compounds in water: a comparison of a continuous active sampler to continuous passive and discrete sampling methods

    USGS Publications Warehouse

    Coes, Alissa L.; Paretti, Nicholas V.; Foreman, William T.; Iverson, Jana L.; Alvarez, David A.

    2014-01-01

    A continuous active sampling method was compared to continuous passive and discrete sampling methods for the sampling of trace organic compounds (TOCs) in water. Results from each method are compared and contrasted in order to provide information for future investigators to use while selecting appropriate sampling methods for their research. The continuous low-level aquatic monitoring (CLAM) sampler (C.I.Agent® Storm-Water Solutions) is a submersible, low flow-rate sampler, that continuously draws water through solid-phase extraction media. CLAM samplers were deployed at two wastewater-dominated stream field sites in conjunction with the deployment of polar organic chemical integrative samplers (POCIS) and the collection of discrete (grab) water samples. All samples were analyzed for a suite of 69 TOCs. The CLAM and POCIS samples represent time-integrated samples that accumulate the TOCs present in the water over the deployment period (19–23 h for CLAM and 29 days for POCIS); the discrete samples represent only the TOCs present in the water at the time and place of sampling. Non-metric multi-dimensional scaling and cluster analysis were used to examine patterns in both TOC detections and relative concentrations between the three sampling methods. A greater number of TOCs were detected in the CLAM samples than in corresponding discrete and POCIS samples, but TOC concentrations in the CLAM samples were significantly lower than in the discrete and (or) POCIS samples. Thirteen TOCs of varying polarity were detected by all of the three methods. TOC detections and concentrations obtained by the three sampling methods, however, are dependent on multiple factors. This study found that stream discharge, constituent loading, and compound type all affected TOC concentrations detected by each method. In addition, TOC detections and concentrations were affected by the reporting limits, bias, recovery, and performance of each method.

  10. Sampling trace organic compounds in water: a comparison of a continuous active sampler to continuous passive and discrete sampling methods.

    PubMed

    Coes, Alissa L; Paretti, Nicholas V; Foreman, William T; Iverson, Jana L; Alvarez, David A

    2014-03-01

    A continuous active sampling method was compared to continuous passive and discrete sampling methods for the sampling of trace organic compounds (TOCs) in water. Results from each method are compared and contrasted in order to provide information for future investigators to use while selecting appropriate sampling methods for their research. The continuous low-level aquatic monitoring (CLAM) sampler (C.I.Agent® Storm-Water Solutions) is a submersible, low flow-rate sampler, that continuously draws water through solid-phase extraction media. CLAM samplers were deployed at two wastewater-dominated stream field sites in conjunction with the deployment of polar organic chemical integrative samplers (POCIS) and the collection of discrete (grab) water samples. All samples were analyzed for a suite of 69 TOCs. The CLAM and POCIS samples represent time-integrated samples that accumulate the TOCs present in the water over the deployment period (19-23 h for CLAM and 29 days for POCIS); the discrete samples represent only the TOCs present in the water at the time and place of sampling. Non-metric multi-dimensional scaling and cluster analysis were used to examine patterns in both TOC detections and relative concentrations between the three sampling methods. A greater number of TOCs were detected in the CLAM samples than in corresponding discrete and POCIS samples, but TOC concentrations in the CLAM samples were significantly lower than in the discrete and (or) POCIS samples. Thirteen TOCs of varying polarity were detected by all of the three methods. TOC detections and concentrations obtained by the three sampling methods, however, are dependent on multiple factors. This study found that stream discharge, constituent loading, and compound type all affected TOC concentrations detected by each method. In addition, TOC detections and concentrations were affected by the reporting limits, bias, recovery, and performance of each method. PMID:24419241

  11. Experiment 2030. EE-2 Temperature Log and Downhole Water Sample

    SciTech Connect

    Grigsby, Charles O.

    1983-07-29

    A temperature log and downhole water sample run were conducted in EE-2 on July 13, 1983. The temperature log was taken to show any changes which had occurred in the fracture-to-wellbore intersections as a result of the Experiment 2020 pumping and to locate fluid entries for taking the water sample. The water sample was requested primarily to determine the arsenic concentration in EE-2 fluids (see memo from C.Grigsby, June 28, 1983 concerning arsenic in EE-3 samples.) The temperature log was run using the thermistor in the ESS-6 water samples.

  12. EVALUATION OF SOLID SORBENTS FOR WATER SAMPLING

    EPA Science Inventory

    The report describes a systematic evaluation of the applicability of macroreticular resins for general and compound-specific sampling of organics. The first portion is an extensive review of current pertinent literature concerned with the use of macroreticular resins for sampling...

  13. 40 CFR 80.8 - Sampling methods for gasoline, diesel fuel, fuel additives, and renewable fuels.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other than... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Sampling methods for gasoline, diesel... Provisions § 80.8 Sampling methods for gasoline, diesel fuel, fuel additives, and renewable fuels....

  14. 19 CFR 151.11 - Request for samples or additional examination packages after release of merchandise.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... packages after release of merchandise. 151.11 Section 151.11 Customs Duties U.S. CUSTOMS AND BORDER... after release of merchandise. If the port director requires samples or additional examination packages... Administration may obtain samples of any food, drug, device, or cosmetic, the importation of which is governed...

  15. 19 CFR 151.11 - Request for samples or additional examination packages after release of merchandise.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... packages after release of merchandise. 151.11 Section 151.11 Customs Duties U.S. CUSTOMS AND BORDER... after release of merchandise. If the port director requires samples or additional examination packages... Administration may obtain samples of any food, drug, device, or cosmetic, the importation of which is governed...

  16. 19 CFR 151.11 - Request for samples or additional examination packages after release of merchandise.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... packages after release of merchandise. 151.11 Section 151.11 Customs Duties U.S. CUSTOMS AND BORDER... after release of merchandise. If the port director requires samples or additional examination packages... Administration may obtain samples of any food, drug, device, or cosmetic, the importation of which is governed...

  17. 19 CFR 151.11 - Request for samples or additional examination packages after release of merchandise.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... packages after release of merchandise. 151.11 Section 151.11 Customs Duties U.S. CUSTOMS AND BORDER... after release of merchandise. If the port director requires samples or additional examination packages... Administration may obtain samples of any food, drug, device, or cosmetic, the importation of which is governed...

  18. 19 CFR 151.11 - Request for samples or additional examination packages after release of merchandise.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... packages after release of merchandise. 151.11 Section 151.11 Customs Duties U.S. CUSTOMS AND BORDER... after release of merchandise. If the port director requires samples or additional examination packages... Administration may obtain samples of any food, drug, device, or cosmetic, the importation of which is governed...

  19. UMTRA project water sampling and analysis plan, Gunnison, Colorado

    SciTech Connect

    Not Available

    1994-06-01

    This water sampling and analysis plan summarizes the results of previous water sampling activities and the plan for water sampling activities for calendar year 1994. A buffer zone monitoring plan is included as an appendix. The buffer zone monitoring plan is designed to protect the public from residual contamination that entered the ground water as a result of former milling operations. Surface remedial action at the Gunnison Uranium Mill Tailings Remedial Action Project site began in 1992; completion is expected in 1995. Ground water and surface water will be sampled semiannually in 1994 at the Gunnison processing site (GUN-01) and disposal site (GUN-08). Results of previous water sampling at the Gunnison processing site indicate that ground water in the alluvium is contaminated by the former uranium processing activities. Background ground water conditions have been established in the uppermost aquifer (Tertiary gravels) at the Gunnison disposal site. The monitor well locations provide a representative distribution of sampling points to characterize ground water quality and ground water flow conditions in the vicinity of the sites. The list of analytes has been modified with time to reflect constituents that are related to uranium processing activities and the parameters needed for geochemical evaluation. Water sampling will be conducted at least semiannually during and one year following the period of construction activities, to comply with the ground water protection strategy discussed in the remedial action plan (DOE, 1992a).

  20. LABORATORY ANALYSES: WATER AND ENVIRONMENTAL SAMPLES

    EPA Science Inventory

    To be presented at the Workshop for Improving the Recognition, Investigation, and Reporting of Waterborne Disease Outbreaks Associated with Drinking, Recreational and Other Waters in Nashville, TN, May 29 - June 1, 2007

  1. Par Pond refill water quality sampling

    SciTech Connect

    Koch, J.W. II; Martin, F.D.; Westbury, H.M.

    1996-08-01

    This study was designed to document anoxia and its cause in the event that the anoxia caused a fish kill. However, no fish kill was observed during this study, and dissolved oxygen and nutrient concentrations generally remained within the range expected for southeastern reservoirs. Par Pond water quality monitoring will continue during the second summer after refill as the aquatic macrophytes become reestablished and nutrients in the sediments are released to the water column.

  2. UMTRA project water sampling and analysis plan -- Shiprock, New Mexico

    SciTech Connect

    Not Available

    1994-02-01

    Water sampling and analysis plan (WSAP) is required for each U.S. Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project site to provide a basis for ground water and surface water sampling at disposal and former processing sites. This WSAP identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequency for the monitoring stations at the Navaho Reservation in Shiprock, New Mexico, UMTRA Project site. The purposes of the water sampling at Shiprock for fiscal year (FY) 1994 are to (1) collect water quality data at new monitoring locations in order to build a defensible statistical data base, (2) monitor plume movement on the terrace and floodplain, and (3) monitor the impact of alluvial ground water discharge into the San Juan River. The third activity is important because the community of Shiprock withdraws water from the San Juan River directly across from the contaminated alluvial floodplain below the abandoned uranium mill tailings processing site.

  3. Visualizing Water Quality Sampling-Events in Florida

    NASA Astrophysics Data System (ADS)

    Bolt, M. D.

    2015-07-01

    Water quality sampling in Florida is acknowledged to be spatially and temporally variable. The rotational monitoring program that was created to capture data within the state's thousands of miles of coastline and streams, and millions of acres of lakes, reservoirs, and ponds may be partly responsible for inducing the variability as an artifact. Florida's new dissolved-oxygen-standard methodology will require more data to calculate a percent saturation. This additional data requirement's impact can be seen when the new methodology is applied retrospectively to the historical collection. To understand how, where, and when the methodological change could alter the environmental quality narrative of state waters requires addressing induced bias from prior sampling events and behaviors. Here stream and coastal water quality data is explored through several modalities to maximize understanding and communication of the spatiotemporal relationships. Previous methodology and expected-retrospective calculations outside the regulatory framework are found to be significantly different, but dependent on the spatiotemporal perspective. Data visualization is leveraged to demonstrate these differences, their potential impacts on environmental narratives, and to direct further review and analysis.

  4. UMTRA project water sampling and analysis plan, Naturita, Colorado

    SciTech Connect

    Not Available

    1994-04-01

    Surface remedial action is scheduled to begin at the Naturita UMTRA Project processing site in the spring of 1994. No water sampling was performed during 1993 at either the Naturita processing site (NAT-01) or the Dry Flats disposal site (NAT-12). Results of previous water sampling at the Naturita processing site indicate that ground water in the alluvium is contaminated as a result of uranium processing activities. Baseline ground water conditions have been established in the uppermost aquifer at the Dry Flats disposal site. Water sampling activities scheduled for April 1994 include preconstruction sampling of selected monitor wells at the processing site, surface water sampling of the San Miguel River, sampling of several springs/seeps in the vicinity of the disposal site, and sampling of two monitor wells in Coke Oven Valley. The monitor well locations provide sampling points to characterize ground water quality and flow conditions in the vicinity of the sites. The list of analytes has been updated to reflect constituents related to uranium processing activities and the parameters needed for geochemical evaluation. Water sampling will be conducted annually at minimum during the period of construction activities.

  5. Beyond Traditional Sampling Synthesis: Real-Time Timbre Morphing Using Additive Synthesis

    NASA Astrophysics Data System (ADS)

    Haken, Lippold; Fitz, Kelly; Christensen, Paul

    Because of its theoretical advantage for making timbral manipulations, sine wave additive synthesis is an attractive alternative to sampling synthesis, which is currently the most popular method for real-time synthesizers. Nevertheless, until recently performers have seldom used additive synthesis because of the practical difficulty of accomplishing these timbral manipulations, which inherently require modification of large numbers of time-varying amplitude and frequency control functions.

  6. Use of ready-mixed concrete plant sludge water in concrete containing an additive or admixture.

    PubMed

    Chatveera, B; Lertwattanaruk, P

    2009-04-01

    In this study, we investigated the feasibility of using sludge water from a ready-mixed concrete plant as mixing water in concrete containing either fly ash as an additive or a superplasticizer admixture based on sulfonated naphthalene-formaldehyde condensates (SNF). The chemical and physical properties of the sludge water and the dry sludge were investigated. Cement pastes were mixed using sludge water containing various levels of total solids content (0.5, 2.5, 5, 7.5, 10, 12.5, and 15%) in order to determine the optimum content in the sludge water. Increasing the total solids content beyond 5-6% tended to reduce the compressive strength and shorten the setting time. Concrete mixes were then prepared using sludge water containing 5-6% total solids content. The concrete samples were evaluated with regard to water required, setting time, slump, compressive strength, permeability, and resistance to acid attack. The use of sludge water in the concrete mix tended to reduce the effect of both fly ash and superplasticizer. Sludge water with a total solids content of less than 6% is suitable for use in the production of concrete with acceptable strength and durability. PMID:19231063

  7. Modeling complexometric titrations of natural water samples.

    PubMed

    Hudson, Robert J M; Rue, Eden L; Bruland, Kenneth W

    2003-04-15

    Complexometric titrations are the primary source of metal speciation data for aquatic systems, yet their interpretation in waters containing humic and fulvic acids remains problematic. In particular, the accuracy of inferred ambient free metal ion concentrations and parameters quantifying metal complexation by natural ligands has been challenged because of the difficulties inherent in calibrating common analytical methods and in modeling the diverse array of ligands present. This work tests and applies a new method of modeling titration data that combines calibration of analytical sensitivity (S) and estimation of concentrations and stability constants for discrete natural ligand classes ([Li]T and Ki) into a single step using nonlinear regression and a new analytical solution to the one-metal/two-ligand equilibrium problem. When applied to jointly model data from multiple titrations conducted at different analytical windows, it yields accurate estimates of S, [Li]T, Ki, and [Cu2+] plus Monte Carlo-based estimates of the uncertainty in [Cu2+]. Jointly modeling titration data at low-and high-analytical windows leads to an efficient adaptation of the recently proposed "overload" approach to calibrating ACSV/CLE measurements. Application of the method to published data sets yields model results with greater accuracy and precision than originally obtained. The discrete ligand-class model is also re-parametrized, using humic and fulvic acids, L1 class (K1 = 10(13) M(-1)), and strong ligands (L(S)) with K(S) > K1 as "natural components". This approach suggests that Cu complexation in NW Mediterranean Sea water can be well represented as 0.8 +/- 0.3/0.2 mg humic equiv/L, 13 +/- 1 nM L1, and 2.5 +/- 0.1 nM L(S) with [CU]T = 3 nM. In coastal seawater from Narragansett Bay, RI, Cu speciation can be modeled as 0.6 +/- 0.1 mg humic equiv/L and 22 +/- 1 nM L1 or approximately 12 nM L1 and approximately 9 nM L(S), with [CU]T = 13 nM. In both waters, the large excess

  8. Microbial Condition of Water Samples from Foreign Fuel Storage Facilities

    SciTech Connect

    Berry, C.J.; Fliermans, C.B.; Santo Domingo, J.

    1997-10-30

    In order to assess the microbial condition of foreign nuclear fuel storage facilities, fourteen different water samples were received from facilities outside the United States that have sent spent nuclear fuel to SRS for wet storage. Each water sample was analyzed for microbial content and activity as determined by total bacteria, viable aerobic bacteria, viable anaerobic bacteria, viable sulfate- reducing bacteria, viable acid-producing bacteria and enzyme diversity. The results for each water sample were then compared to other foreign samples and to data from the receiving basin for off- site fuel (RBOF) at SRS.

  9. UMTRA project water sampling and analysis plan, Riverton, Wyoming

    SciTech Connect

    Not Available

    1994-03-01

    Surface remediation was completed at the former uranium mill site in Riverton, Wyoming, in 1990. Residual radioactive materials (contaminated soil and debris) were removed and disposed of at Union Carbide Corporation`s (Umetco) nearby Gas Hills Title 2 facility. Ground water in the surficial and semiconfined aquifers (known collectively as the `uppermost aquifer`) below the former mill and tailings site has been contaminated. No contamination has been detected in the deeper, confined sandstone aquifer. The contaminant plume extends off site to the south and east. The plume is constrained by surface wetlands and small streams to the east and west of the site and by the Little Wind River to the south. Fifteen monitor wells installed in 1993 were sampled to better define the contaminant plume and to provide additional water quality data for the baseline risk assessment. Samples also were collected from domestic wells in response to a request by the Wyoming Department of Environmental Quality in January 1994. No contamination attributable to the former uranium milling operations have ever been detected in any of the domestic wells used for potable supplies.

  10. 49 CFR 199.111 - Retention of samples and additional testing.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Retention of samples and additional testing. 199.111 Section 199.111 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY DRUG AND ALCOHOL TESTING Drug Testing...

  11. 31. VIEW FROM SOUTHWEST TO CORNER WHERE SAMPLING/CRUSHING ADDITIONS ABUT ...

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

    31. VIEW FROM SOUTHWEST TO CORNER WHERE SAMPLING/CRUSHING ADDITIONS ABUT CRUSHED OXIDIZED ORE BIN. INTACT BARREN SOLUTION TANK VISIBLE IN FRONT OF CRUSHED ORE BIN. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  12. Decontaminating materials used in ground water sampling devices: Organic contaminants

    SciTech Connect

    Parker, L.V.; Ranney, T.A.

    2000-12-31

    In these studies, the efficiency of various decontamination protocols was tested on small pieces of materials commonly used in ground water sampling devices. Three materials, which ranged in ability to sorb organic solutes, were tested: stainless steel (SS), rigid polyvinyl chloride (PVC), and polytetrafluoroethylene (PTFE). The test pieces were exposed to two aqueous test solutions: One contained three volatile organic compounds (VOCs) and one nitroaromatic compound, and the other contained four pesticides. Also, three types of polymetic tubing were exposed to pesticide solutions. Generally, the contact times were 10 minutes and 24 hours for sorption and desorption. The contaminants were removed from the nonpermeable SS and the less-sorptive rigid PVC test pieces simply by washing with a hot detergent solution and rinsing with hot water. Additional treatment was required for the PTFE test pieces exposed to the VOCs and for the low-density polyethylene (LDPE) tubing exposed to the pesticide test solution. Solvent rinsing did not improve removal of the three VOCs form the PTFE and only marginally improved removal of the residual pesticides from the LDPE. However, a hot water and detergent wash and rinse followed by oven drying at approximately 105 C was effective for removing the VOCs from the PTFE and substantially reduced pesticide contamination from the LDPE.

  13. Studies of levels of biogenic amines in meat samples in relation to the content of additives.

    PubMed

    Jastrzębska, Aneta; Kowalska, Sylwia; Szłyk, Edward

    2016-01-01

    The impact of meat additives on the concentration of biogenic amines and the quality of meat was studied. Fresh white and red meat samples were fortified with the following food additives: citric and lactic acids, disodium diphosphate, sodium nitrite, sodium metabisulphite, potassium sorbate, sodium chloride, ascorbic acid, α-tocopherol, propyl 3,4,5-trihydroxybenzoate (propyl gallate) and butylated hydroxyanisole. The content of spermine, spermidine, putrescine, cadaverine, histamine, tyramine, tryptamine and 2-phenylethylamine was determined by capillary isotachophoretic methods in meat samples (fresh and fortified) during four days of storage at 4°C. The results were applied to estimate the impact of the tested additives on the formation of biogenic amines in white and red meat. For all tested meats, sodium nitrite, sodium chloride and disodium diphosphate showed the best inhibition. However, cadaverine and putrescine were characterised by the biggest changes in concentration during the storage time of all the additives. Based on the presented data for the content of biogenic amines in meat samples analysed as a function of storage time and additives, we suggest that cadaverine and putrescine have a significant impact on meat quality. PMID:26515667

  14. July 2010 Natural Gas and Produced Water Sampling at the Gasbuggy, New Mexico, Site

    SciTech Connect

    2011-01-01

    Annual natural gas and produced water monitoring was conducted for gas wells adjacent to Section 36, where the Gasbuggy test was conducted, in accordance with the draft Long-Term Surveillance and Maintenance Plan for the Gasbuggy Site, Rio Arriba County, New Mexico. Sampling and analysis was conducted as specified in the Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites. (LMS/PLN/S04351, continually updated). Natural gas samples were collected for tritium and carbon-14 analysis. Produced water samples were collected and analyzed for tritium, gamma-emitting radionuclides (by high-resolution gamma spectrometry), gross alpha, and gross beta. An additional water sample was collected from well 29-6 Water Hole for analysis of tritium and gamma-emitting radionuclides. A duplicate produced water sample was collected from well 30-039-21743.

  15. UMTRA water sampling and analysis plan, Tuba City, Arizona. Draft

    SciTech Connect

    Not Available

    1993-09-01

    The purpose of this document is to provide background, guidance, and justification for fiscal year (FY) 1994 water sampling activities for the uranium mil tailings site at Tuba City, Arizona. This sampling and analysis plan will form the basis for groundwater sampling and analysis work orders to be implemented in FY94.

  16. Monitoring of fluoride in water samples using a smartphone.

    PubMed

    Levin, Saurabh; Krishnan, Sunderrajan; Rajkumar, Samuel; Halery, Nischal; Balkunde, Pradeep

    2016-05-01

    In several parts of India, groundwater is the only reliable, year round source for drinking water. Prevention of fluorosis, a chronic disease resulting from excess intake of fluoride, requires the screening of all groundwater sources for fluoride in endemic areas. In this paper, the authors present a field deployable colorimetric analyzer based on an inexpensive smartphone embedded with digital camera for taking photograph of the colored solution as well as an easy-fit, and compact sample chamber (Akvo Caddisfly). Phones marketed by different smartphone makers were used. Commercially available zirconium xylenol orange reagent was used for determining fluoride concentration. A software program was developed to use with the phone for recording and analyzing the RGB color of the picture. Linear range for fluoride estimation was 0-2mgl(-1). Around 200 samples, which consisted of laboratory prepared as well as field samples collected from different locations in Karnataka, India, were tested with Akvo Caddisfly. The results showed a significant positive correlation between Ion Selective Electrode (ISE) method and Akvo Caddisfly (Phones A, B and C), with correlation coefficient ranging between 0.9952 and 1.000. In addition, there was no significant difference in the mean fluoride content values between ISE and Phone B and C except for Phone A. Thus the smartphone method is economical and suited for groundwater fluoride analysis in the field. PMID:26874766

  17. UMTRA project water sampling and analysis plan, Tuba City, Arizona

    SciTech Connect

    1996-02-01

    Planned, routine ground water sampling activities at the U.S. Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project site in Tuba City, Arizona, are described in the following sections of this water sampling and analysis plan (WSAP). This plan identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequency for the stations routinely monitored at the site. The ground water data are used for site characterization and risk assessment. The regulatory basis for routine ground water monitoring at UMTRA Project sites is derived from the U.S. Environmental Protection Agency (EPA) regulations in 40 CFR Part 192 (1994) and the final EPA standards of 1995 (60 FR 2854). Sampling procedures are guided by the UMTRA Project standard operating procedures (SOP) (JEG, n.d.), and the most effective technical approach for the site.

  18. Turbulent flow of oil-water emulsions with polymer additives

    NASA Astrophysics Data System (ADS)

    Manzhai, V. N.; Monkam Clovis Le Grand, Monkam; Abdousaliamov, A. V.

    2014-08-01

    The article outlines direct and reverse oil-water emulsions. Microphotography study of these emulsions was carried out. The effect of water-soluble and oil soluble polymers on the emulsion structure and their turbulent flow velocity in cylindrical channel was investigated. It has been experimentally proven that if the fluid being transported is not homogeneous, but a two-phase oil-water emulsion, only the polymer that is compatible with dispersion medium and capable of dissolving in this medium can reduce the hydrodynamic resistance of the fluid flow. Thus, the resistance in direct emulsions can be reduced by water- soluble polyacrylamide, while oil-soluble polyhexene can be applied for reverse emulsions.

  19. The stability of chlorofluorocarbons (CFCs) in ground-water samples archived in borosilicate ampoules

    USGS Publications Warehouse

    Shapiro, Stephanie Dunkle; Busenberg, Eurybiades; Plummer, L. Niel

    2005-01-01

    The U.S. Geological Survey (USGS) Chlorofluorocarbon (CFC) Laboratory in Reston, Va., has been measuring concentrations of CFCs in ground-water samples since 1989 to estimate the year that a water sample was recharged to a ground-water flow system. The water samples have been collected in flame-sealed borosilicate ampoules. Typically for each site, three samples were analyzed within days to a few months after collection, and additional samples were archived for extended periods of time (up to four years). The stability of CFC concentrations in the archived water samples from the USGS CFC Laboratory was investigated by analyzing the CFC concentrations in archived water samples and comparing them with the CFC concentrations that were obtained soon after the samples were collected. The archived samples selected for analysis were chosen from sites with a wide variety of hydrogeologic and geochemical conditions. For CFC-11 and CFC-12 concentrations, approximately 14% and 10.5%, respectively, of the archived samples were statistically different (both higher and lower) from the concentrations obtained from analyses conducted soon after the sample collection. Most of the extraneous values were attributed to natural variability of CFC concentrations originally in the water discharged from wells, rather than to microbial degradation within the ampoule on storage.

  20. Exfoliated MoS2 in Water without Additives

    PubMed Central

    Forsberg, Viviane; Zhang, Renyun; Bäckström, Joakim; Dahlström, Christina; Andres, Britta; Norgren, Magnus; Andersson, Mattias; Hummelgård, Magnus; Olin, Håkan

    2016-01-01

    Many solution processing methods of exfoliation of layered materials have been studied during the last few years; most of them are based on organic solvents or rely on surfactants and other funtionalization agents. Pure water should be an ideal solvent, however, it is generally believed, based on solubility theories that stable dispersions of water could not be achieved and systematic studies are lacking. Here we describe the use of water as a solvent and the stabilization process involved therein. We introduce an exfoliation method of molybdenum disulfide (MoS2) in pure water at high concentration (i.e., 0.14 ± 0.01 g L−1). This was achieved by thinning the bulk MoS2 by mechanical exfoliation between sand papers and dispersing it by liquid exfoliation through probe sonication in water. We observed thin MoS2 nanosheets in water characterized by TEM, AFM and SEM images. The dimensions of the nanosheets were around 200 nm, the same range obtained in organic solvents. Electrophoretic mobility measurements indicated that electrical charges may be responsible for the stabilization of the dispersions. A probability decay equation was proposed to compare the stability of these dispersions with the ones reported in the literature. Water can be used as a solvent to disperse nanosheets and although the stability of the dispersions may not be as high as in organic solvents, the present method could be employed for a number of applications where the dispersions can be produced on site and organic solvents are not desirable. PMID:27120098

  1. Exfoliated MoS2 in Water without Additives.

    PubMed

    Forsberg, Viviane; Zhang, Renyun; Bäckström, Joakim; Dahlström, Christina; Andres, Britta; Norgren, Magnus; Andersson, Mattias; Hummelgård, Magnus; Olin, Håkan

    2016-01-01

    Many solution processing methods of exfoliation of layered materials have been studied during the last few years; most of them are based on organic solvents or rely on surfactants and other funtionalization agents. Pure water should be an ideal solvent, however, it is generally believed, based on solubility theories that stable dispersions of water could not be achieved and systematic studies are lacking. Here we describe the use of water as a solvent and the stabilization process involved therein. We introduce an exfoliation method of molybdenum disulfide (MoS2) in pure water at high concentration (i.e., 0.14 ± 0.01 g L-1). This was achieved by thinning the bulk MoS2 by mechanical exfoliation between sand papers and dispersing it by liquid exfoliation through probe sonication in water. We observed thin MoS2 nanosheets in water characterized by TEM, AFM and SEM images. The dimensions of the nanosheets were around 200 nm, the same range obtained in organic solvents. Electrophoretic mobility measurements indicated that electrical charges may be responsible for the stabilization of the dispersions. A probability decay equation was proposed to compare the stability of these dispersions with the ones reported in the literature. Water can be used as a solvent to disperse nanosheets and although the stability of the dispersions may not be as high as in organic solvents, the present method could be employed for a number of applications where the dispersions can be produced on site and organic solvents are not desirable. PMID:27120098

  2. Additive non-uniform random sampling in superimposed fiber Bragg grating strain gauge

    NASA Astrophysics Data System (ADS)

    Ma, Y. C.; Liu, H. Y.; Yan, S. B.; Yang, Y. H.; Yang, M. W.; Li, J. M.; Tang, J.

    2013-05-01

    This paper demonstrates an additive non-uniform random sampling and interrogation method for dynamic and/or static strain gauge using a reflection spectrum from two superimposed fiber Bragg gratings (FBGs). The superimposed FBGs are designed to generate non-equidistant space of a sensing pulse train in the time domain during dynamic strain gauge. By combining centroid finding with smooth filtering methods, both the interrogation speed and accuracy are improved. A 1.9 kHz dynamic strain is measured by generating an additive non-uniform randomly distributed 2 kHz optical sensing pulse train from a mean 500 Hz triangular periodically changing scanning frequency.

  3. UMTRA project water sampling and analysis plan, Monument Valley, Arizona

    SciTech Connect

    Not Available

    1994-04-01

    The Monument Valley Uranium Mill Tailings Remedial Action (UMTRA) Project site in Cane Valley is a former uranium mill that has undergone surface remediation in the form of tailings and contaminated materials removal. Contaminated materials from the Monument Valley (Arizona) UMTRA Project site have been transported to the Mexican Hat (Utah) UMTRA Project site for consolidation with the Mexican Hat tailings. Tailings removal was completed in February 1994. Three geologic units at the site contain water: the unconsolidated eolian and alluvial deposits (alluvial aquifer), the Shinarump Conglomerate (Shinarump Member), and the De Chelly Sandstone. Water quality analyses indicate the contaminant plume has migrated north of the site and is mainly in the alluvial aquifer. An upward hydraulic gradient in the De Chelly Sandstone provides some protection to that aquifer. This water sampling and analysis plan recommends sampling domestic wells, monitor wells, and surface water in April and September 1994. The purpose of sampling is to continue periodic monitoring for the surface program, evaluate changes to water quality for site characterization, and provide data for the baseline risk assessment. Samples taken in April will be representative of high ground water levels and samples taken in September will be representative of low ground water levels. Filtered and nonfiltered samples will be analyzed for plume indicator parameters and baseline risk assessment parameters.

  4. UMTRA water sampling and analysis plan, Lakeview, Oregon

    SciTech Connect

    Not Available

    1993-09-29

    The purpose of this document is to provide background, guidance, and justification for water sampling activities for the Lakeview, Oregon, Uranium Mill Tailings Remedial Action (UMTRA) processing and disposal sites. This water sampling and analysis plan will form the basis for groundwater sampling and analysis work orders (WSAWO) to be implemented during 1993. Monitoring at the former Lakeview processing site is for characterization purposes and in preparation for the risk assessment, scheduled for the fall of 1993. Compliance monitoring was conducted at the disposal site. Details of the sampling plan are discussed in Section 5.0.

  5. 5. VIEW TO SOUTH, SAMPLING BUILDING AND WATER TOWER. ...

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

    5. VIEW TO SOUTH, SAMPLING BUILDING AND WATER TOWER. - Vanadium Corporation of America (VCA) Naturita Mill, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

  6. 10. VIEW TO SOUTHEAST, SAMPLING BUILDING, FOUNDATION, WATER TOWER, AND ...

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

    10. VIEW TO SOUTHEAST, SAMPLING BUILDING, FOUNDATION, WATER TOWER, AND SKINNER SALT ROASTERS. - Vanadium Corporation of America (VCA) Naturita Mill, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

  7. 4. VIEW TO NORTHEAST, SKINNER SALT ROASTERS, SAMPLING BUILDING, WATER ...

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

    4. VIEW TO NORTHEAST, SKINNER SALT ROASTERS, SAMPLING BUILDING, WATER TOWER, AND OFFICE BUILDING. - Vanadium Corporation of America (VCA) Naturita Mill, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

  8. Implications of heterogeneous distributions of organisms on ballast water sampling.

    PubMed

    Costa, Eliardo G; Lopes, Rubens M; Singer, Julio M

    2015-02-15

    Ballast water sampling is one of the problems still needing investigation in order to enforce the D-2 Regulation of the International Convention for the Control and Management of Ship Ballast Water and Sediments. Although statistical "representativeness" of the sample is an issue usually discussed in the literature, neither a definition nor a clear description of its implications are presented. In this context, we relate it to the heterogeneity of the distribution of organisms in ballast water and show how to specify compliance tests under different models based on the Poisson and negative binomial distributions. We provide algorithms to obtain minimum sample volumes required to satisfy fixed limits on the probabilities of Type I and II errors. We show that when the sample consists of a large number of aliquots, the Poisson model may be employed even under moderate heterogeneity of the distribution of the organisms in the ballast water tank. PMID:25510550

  9. False cyanide formation during drinking water sample preservation and storage.

    PubMed

    Delaney, Michael F; Blodget, Charles; Hoey, Corinna E; McSweeney, Nancy E; Epelman, Polina A; Rhode, Steven F

    2007-12-15

    Carefully controlled bench-scale and on-site experiments demonstrated that cyanide can form in the treated drinking water sample container during preservation and storage. In the bench-scale experiment, treated tap water samples were collected on 20 days over six months. The tap water samples were split and some of the splits were spiked with formaldehyde, a known ozone disinfection byproduct, held for three hours and tested for cyanide. Then they were preserved and held for 2-10 days. None of the 69 initial samples had cyanide detects, but 22 of 49 formaldehyde-spiked samples and three of the 20 unspiked samples developed detectable cyanide concentrations during storage. In the on-site experiment, six samples were collected at a finished water tap at an ozone/chloramination treatment plant over three days. Each sample was split, and a portion was spiked with formaldehyde. Each portion was analyzed in triplicate after three different procedures: (1) immediately distilled on-site, (2) stabilized on-site in a distillation tube and distilled back at the laboratory several days later, or (3) following the conventional procedure of preserving the sample to pH > 12 in a container and distilling the sample back at the laboratory. Only the samples handled in the conventional way had detectable amounts of cyanide. Both experiments demonstrated that cyanide can form during conventional preservation and storage, and it is likely that the cyanide detected for this treated drinking water was formed in the sample container as a consequence of the preservation and storage conditions. PMID:18200867

  10. Nitrification in lake sediment with addition of drinking water treatment residuals.

    PubMed

    Wang, Changhui; Liu, Juanfeng; Wang, Zhixin; Pei, Yuansheng

    2014-06-01

    Drinking water treatment residuals (WTRs), non-hazardous by-products generated during potable water production, can effectively reduce the lake internal phosphorus (P) loading and improve water quality in lakes. It stands to reason that special attention regarding the beneficial reuse of WTRs should be given not only to the effectiveness of P pollution control, but also to the effects on the migration and transformation of other nutrients (e.g., nitrogen (N)). In this work, based on laboratory enrichment tests, the effects of WTRs addition on nitrification in lake sediment were investigated using batch tests, fluorescence in situ hybridization, quantitative polymerase chain reaction and phylogenetic analysis techniques. The results indicated that WTRs addition had minor effects on the morphologies of AOB and NOB; however, the addition slightly enhanced the sediment nitrification potential from 12.8 to 13.2 μg-N g(-1)-dry sample h(-1) and also increased the ammonia oxidation bacteria (AOB) and nitrite oxidizing bacteria (NOB) abundances, particularly the AOB abundances (P < 0.05), which increased from 1.11 × 10(8) to 1.31 × 10(8) copies g(-1)-dry sample. Moreover, WTRs addition was beneficial to the enrichment of Nitrosomonas and Nitrosospira multiformis and promoted the emergence of a new Nitrospira cluster, causing the increase in AOB and NOB diversities. Further analysis showed that the variations of nitrification in lake sediment after WTRs addition were primarily due to the decrease of bioavailable P, the introduction of new nitrifiers and the increase of favorable carriers for microorganism attachment in sediments. Overall, these results suggested that WTRs reuse for the control of lake internal P loading would also lead to conditions that are beneficial to nitrification. PMID:24681379

  11. GROUND WATER PURGING AND SAMPLING METHODS: HISTORY VS. HYSTERIA

    EPA Science Inventory

    It has been over 10 years since the low-flow ground water purging and sampling method was initially reported in the literature. The method grew from the recognition that well purging was necessary to collect representative samples, bailers could not achieve well purging, and high...

  12. Superoxygenated Water as an Experimental Sample for NMR Relaxometry

    ERIC Educational Resources Information Center

    Nestle, Nikolaus; Dakkouri, Marwan; Rauscher, Hubert

    2004-01-01

    The increase in NMR relaxation rates as a result of dissolved paramagnetic species on the sample of superoxygenated drinking water is demonstrated. It is concluded that oxygen content in NMR samples is an important issue and can give rise to various problems in the interpretation of both spectroscopic and NMR imaging or relaxation experiments.

  13. RAPID DETERMINATION OF {sup 210} PO IN WATER SAMPLES

    SciTech Connect

    Maxwell, S.

    2013-05-22

    A new rapid method for the determination of {sup 210}Po in water samples has been developed at the Savannah River National Laboratory (SRNL) that can be used for emergency response or routine water analyses. If a radiological dispersive device (RDD) event or a radiological attack associated with drinking water supplies occurs, there will be an urgent need for rapid analyses of water samples, including drinking water, ground water and other water effluents. Current analytical methods for the assay of {sup 210}Po in water samples have typically involved spontaneous auto-deposition of {sup 210}Po onto silver or other metal disks followed by counting by alpha spectrometry. The auto-deposition times range from 90 minutes to 24 hours or more, at times with yields that may be less than desirable. If sample interferences are present, decreased yields and degraded alpha spectrums can occur due to unpredictable thickening in the deposited layer. Separation methods have focused on the use of Sr Resin, often in combination with 210Pb analysis. A new rapid method for {sup 210}Po in water samples has been developed at the Savannah River National Laboratory (SRNL) that utilizes a rapid calcium phosphate co-precipitation method, separation using DGA Resin (N,N,N,N-tetraoctyldiglycolamide extractant-coated resin, Eichrom Technologies or Triskem-International), followed by rapid microprecipitation of {sup 210}Po using bismuth phosphate for counting by alpha spectrometry. This new method can be performed quickly with excellent removal of interferences, high chemical yields and very good alpha peak resolution, eliminating any potential problems with the alpha source preparation for emergency or routine samples. A rapid sequential separation method to separate {sup 210} Po and actinide isotopes was also developed. This new approach, rapid separation with DGA Resin plus microprecipitation for alpha source preparation, is a significant advance in radiochemistry for the rapid

  14. Impact of Oxidant Residuals on Ground Water Samples at ISCO Sites: Recommended Guidelines for Sample Preservation

    EPA Science Inventory

    In-situ chemical oxidation (ISCO) involves the introduction of a chemical oxidant into the subsurface for the purpose of transforming ground water contaminants into less toxic or harmless byproducts. Due to oxidant persistence, ground water samples collected at hazardous waste si...

  15. Oxygen Isotopic Analyses of Water Extracted from Lunar Samples

    NASA Astrophysics Data System (ADS)

    Nunn Martinez, M.; Thiemens, M. H.

    2014-12-01

    Oxygen exists in lunar materials in distinct phases having unique sources and equilibration histories. The oxygen isotopic composition (δ17O, δ18O) of various components of lunar materials has been studied extensively, but analyses of water in these samples are relatively sparse [1-3]. Samples collected on the lunar surface reflect not only the composition of their source reservoirs but also contributions from asteroidal and cometary impacts, interactions with solar wind and cosmic radiation, among other surface processes. Isotopic characterization of oxygen in lunar water could help resolve the major source of water in the Earth-Moon system by revealing if lunar water is primordial, asteroidal, or cometary in origin [1]. Methods: A lunar rock/soil sample is pumped to high vacuum to remove physisorbed water before heating step-wise to 50, 150, and 1000°C to extract extraterrestrial water without terrestrial contamination. The temperature at which water is evolved is proportional to the strength with which the water is bound in the sample and the relative difficulty of exchanging oxygen atoms in that water. This allows for the isolated extraction of water bound in different phases, which could have different source reservoirs and/or histories, as evidenced by the mass (in)dependence of oxygen compositions. A low blank procedure was developed to accommodate the low water content of lunar material [4]. Results: Oxygen isotopic analyses of lunar water extracted by stepwise heating lunar basalts and breccias with a range of compositions, petrologic types, and surface exposure ages will be presented. The cosmic ray exposure age of these samples varies by two orders of magnitude, and we will consider this in discussing the effects of solar wind and cosmic radiation on the oxygen isotopic composition (Δ17O). I will examine the implications of our water analyses for the composition of the oxygen-bearing reservoir from which that water formed, the effects of surface

  16. Considerations of acidifying water samples for 99Tc analysis.

    PubMed

    Blanchard, R L; Lieberman, R; Richardson, W S; Wakamo, C L

    1993-08-01

    Environmental water samples are routinely acidified before radionuclide analysis to prevent adsorption of radionuclides on the container walls. This study addresses the concern for volatilizing 99Tc from acid solutions during evaporation before beta analysis has been addressed. Water samples can be acidified to pH 1.7 with nitric acid and evaporated to dryness on planchets without significant losses of technetium due to volatilization. However, the planchets should not be flamed unless a detergent is used, and control samples should be flamed to determine the loss of activity under the conditions used. PMID:8392504

  17. UMTRA project water sampling and analysis plan, Mexican Hat, Utah

    SciTech Connect

    Not Available

    1994-04-01

    The Mexican Hat, Utah, Uranium Mill Tailings Remedial Action (UMTRA) Project site is a former uranium mill that is undergoing surface remediation in the form of on-site tailings stabilization. Contaminated surface materials from the Monument Valley, Arizona, UMTRA Project site have been transported to the Mexican Hat site and are being consolidated with the Mexican Hat tailings. The scheduled completion of the tailings disposal cell is August 1995. Water is found in two geologic units at the site: the Halgaito Shale Formation and the Honaker Trail Formation. The tailings rest on the Halgaito Shale, and water contained in that unit is a result of milling activities and, to a lesser extent, water released from the tailings from compaction during remedial action construction of the disposal cell. Water in the Halgaito Shale flows through fractures and discharges at seeps along nearby arroyos. Flow from the seeps will diminish as water drains from the unit. Ground water in the lower unit, the Honaker Trail Formation, is protected from contamination by an upward hydraulic gradient. There are no nearby water supply wells because of widespread poor background ground water quality and quantity, and the San Juan River shows no impacts from the site. This water sampling and analysis plan (WSAP) recommends sampling six seeps and one upgradient monitor well compared in the Honaker Trail Formation. Samples will be taken in April 1994 (representative of high group water levels) and September 1994 (representative of low ground water levels). Analyses will be performed on filtered samples for plume indicator parameters.

  18. Chapter A3. Cleaning of Equipment for Water Sampling

    USGS Publications Warehouse

    Wilde, Franceska D., (Edited By); Radtke, Dean B.; Gibs, Jacob; Iwatsubo, Rick T.

    1998-01-01

    The National Field Manual for the Collection of Water-Quality Data (National Field Manual) describes protocols and provides guidelines for U.S. Geological Survey (USGS) personnel who collect data used to assess the quality of the Nation's surface-water and ground-water resources. Chapter A3 describes procedures for cleaning the equipment used to collect and process samples of surface water and ground water and procedures for assessing the efficacy of the equipment-cleaning process. This chapter is designed for use with the other chapters of this field manual. Each chapter of the National Field Manual is published separately and revised periodically. Newly published and revised chapters will be posted on the USGS page 'National Field Manual for the Collection of Water-Quality Data.' The URL for this page is http://pubs.water.usgs.gov/twri9A/ (accessed September 20, 2004).

  19. On the asymptotic improvement of supervised learning by utilizing additional unlabeled samples - Normal mixture density case

    NASA Technical Reports Server (NTRS)

    Shahshahani, Behzad M.; Landgrebe, David A.

    1992-01-01

    The effect of additional unlabeled samples in improving the supervised learning process is studied in this paper. Three learning processes. supervised, unsupervised, and combined supervised-unsupervised, are compared by studying the asymptotic behavior of the estimates obtained under each process. Upper and lower bounds on the asymptotic covariance matrices are derived. It is shown that under a normal mixture density assumption for the probability density function of the feature space, the combined supervised-unsupervised learning is always superior to the supervised learning in achieving better estimates. Experimental results are provided to verify the theoretical concepts.

  20. Water Imbibition into Rock as Affected by Sample Shape, Pore, Conductivity, and Antecedent Water Content

    SciTech Connect

    R.P. Ewing

    2005-08-29

    Infiltration is often presumed to follow Philip's equation, I = st{sup 1/2}, where I is cumulative infiltration, s is sorptivity, and t is time. This form of the equation is appropriate for short times, and/or for negligible gravitational effects. For a uniform soil, this equation describes a plot of log(mass imbibed) versus log(time), with a slope (imbibition exponent) of 1/2. The equation has also been applied to low-porosity rocks, where the extremely small pores render gravitational forces negligible. Experiments recently performed on a wide variety of rocks produced imbibition exponents from 0.2 to 0.5. Many rock types showed initial imbibition proceeding as I {approx} t{sup 1/4}, then later switched to ''normal'' (t{sup 1/2}) behavior. The distance to the wetting front that corresponds to this cross-over behavior was found to be related to the sample shape: tall thin samples are more likely to exhibit the exponent 1/4, and to cross over to 1/2-type behavior later, while short, squat samples are less likely to display the 1/4-type behavior at all. Additionally, the exponents are sensitive to antecedent water content, with initially wetter samples having smaller values. In this study, we present the experimental data, and provide a consistent and physically-based explanation using percolation theory. The analogy between imbibition and diffusion is used to model imbibition into samples with low pore connectivity, with the exponents and their crossover behavior emerging from a random walk process. All laboratory phenomena--different exponents, crossover behavior, and effects of sample shape and antecedent water content--are reproduced by the model, with similar patterns across experiment and simulation. We conclude both that diffusion is a useful and powerful conceptual model for understanding imbibition, and also that imbibition experiments, being simpler than diffusion measurements, can be used to examine diffusive behavior in rock.

  1. Effects of Additives, Photodegradation, and Water-tree Degradation on the Photoluminescence in Polyethylene and Polypropylene

    NASA Astrophysics Data System (ADS)

    Ito, Toshihide; Fuse, Norikazu; Ohki, Yoshimichi

    Photoluminescence (PL) spectra induced by irradiation of ultraviolet photons are compared among low-density polyethylene (LDPE), crosslinked polyethylene (XLPE), and polypropylene (PP). Three PL bands appear around 4.2, 3.6, and 3.1 eV in LDPE and XLPE, while similar three PL bands are observed at similar energies in PP. The PL spectra and their decay profiles are independent of the presence of additives and are also independent of whether the samples were crosslinked or not. These results indicate that neither the additives nor the crosslinking has any significant effects on the respective three PLs in PE and PP. When the sample was pre-irradiated by the ultraviolet photons under different atmospheres (air, O2, and vacuum), all the PL intensities decrease with the progress of the pre-irradiation regardless of whether the sample is PE or PP. Therefore, all the PLs are considered to result from impurities. In all the pre-irradiated samples, a new PL band appears at 2.9 eV, of which intensity is stronger when the oxygen partial pressure during the pre-irradiation was lower. This PL is considered to be due to photo-induced conjugated double bonds. It has also been confirmed that water-tree degradation in LDPE or in XLPE does not contribute to PL.

  2. Sample port design for ballast water sampling: Refinement of guidance regarding the isokinetic diameter.

    PubMed

    Wier, Timothy P; Moser, Cameron S; Grant, Jonathan F; First, Matthew R; Riley, Scott C; Robbins-Wamsley, Stephanie H; Drake, Lisa A

    2015-09-15

    By using an appropriate in-line sampling system, it is possible to obtain representative samples of ballast water from the main ballast line. An important parameter of the sampling port is its "isokinetic diameter" (DISO), which is the diameter calculated to determine the velocity of water in the sample port relative to the velocity of the water in the main ballast line. The guidance in the U.S. Environmental Technology Verification (ETV) program protocol suggests increasing the diameter from 1.0× DISO (in which velocity in the sample port is equivalent to velocity in the main line) to 1.5-2.0× DISO. In this manner, flow velocity is slowed-and mortality of organisms is theoretically minimized-as water enters the sample port. This report describes field and laboratory trials, as well as computational fluid dynamics modeling, to refine this guidance. From this work, a DISO of 1.0-2.0× (smaller diameter sample ports) is recommended. PMID:26187400

  3. Compositing water samples for analysis of volatile organic compounds

    USGS Publications Warehouse

    Lopes, T.J.; Fallon, J.D.; Maluk, T.L.

    2000-01-01

    Accurate mean concentrations of volatile organic compounds (VOCs) can easily and economically be obtained from a single VOC analysis by using proven methods of collecting representative, discrete water samples and compositing them with a gas-tight syringe. The technique can be used in conjunction with chemical analysis by a conventional laboratory, field-portable equipment, or a mobile laboratory. The type of mean concentration desired depends on the objectives of monitoring. For example, flow-weighted mean VOC concentrations can be used to estimate mass loadings in wastewater and urban storm water, and spatially integrated mean VOC concentrations can be used to assess sources of drinking water (e.g., reservoirs and rivers). The mean error in a discrete sample due to compositing is about 2% for most VOC concentrations greater than 0.1 ??g/L. The total error depends on the number of discrete samples comprising the composite sample and precision of the chemical analysis.Accurate mean concentrations of volatile organic compounds (VOCs) can easily and economically be obtained from a single VOC analysis by using proven methods of collecting representative, discrete water samples and compositing them with a gas-tight syringe. The technique can be used in conjunction with chemical analysis by a conventional laboratory, field-portable equipment, or a mobile laboratory. The type of mean concentration desired depends on the objectives of monitoring. For example, flow-weighted mean VOC concentrations can be used to estimate mass loadings in wastewater and urban storm water, and spatially integrated mean VOC concentrations can be used to assess sources of drinking water (e.g., reservoirs and rivers). The mean error in a discrete sample due to compositing is about 2% for most VOC concentrations greater than 0.1 ??g/L. The total error depends on the number of discrete samples comprising the composite sample and precision of the chemical analysis.Researchers are able to derive

  4. Chapter A2. Selection of Equipment for Water Sampling

    USGS Publications Warehouse

    Wilde, Franceska D., (Edited By); Radtke, Dean B.; Gibs, Jacob; Iwatsubo, Rick T.

    1998-01-01

    The National Field Manual for the Collection of Water-Quality Data (National Field Manual) describes protocols and provides guidelines for U.S. Geological Survey (USGS) personnel who collect data used to assess the quality of the Nation's surface-water and ground-water resources. This chapter of the manual addresses the selection of equipment commonly used by USGS personnel to collect and process water-quality samples. Each chapter of the National Field Manual is published separately and revised periodically. Newly published and revised chapters will be posted on the World Wide Web on the USGS page 'National Field Manual for the Collection of Water-Quality Data.' The URL for this page is http://pubs.water.usgs.gov/twri9A/ (accessed March 20, 2003).

  5. Statistical inference for the additive hazards model under outcome-dependent sampling

    PubMed Central

    Yu, Jichang; Liu, Yanyan; Sandler, Dale P.; Zhou, Haibo

    2015-01-01

    Cost-effective study design and proper inference procedures for data from such designs are always of particular interests to study investigators. In this article, we propose a biased sampling scheme, an outcome-dependent sampling (ODS) design for survival data with right censoring under the additive hazards model. We develop a weighted pseudo-score estimator for the regression parameters for the proposed design and derive the asymptotic properties of the proposed estimator. We also provide some suggestions for using the proposed method by evaluating the relative efficiency of the proposed method against simple random sampling design and derive the optimal allocation of the subsamples for the proposed design. Simulation studies show that the proposed ODS design is more powerful than other existing designs and the proposed estimator is more efficient than other estimators. We apply our method to analyze a cancer study conducted at NIEHS, the Cancer Incidence and Mortality of Uranium Miners Study, to study the risk of radon exposure to cancer. PMID:26379363

  6. Evaluation of preconcentration methods in the analysis of synthetic musks in whole-water samples.

    PubMed

    Cavalheiro, Joana; Prieto, Ailette; Zuloaga, Olatz; Preudhomme, Hugues; Amouroux, David; Monperrus, Mathilde

    2015-07-01

    According to the European Water Framework Directive, environmental assessment of organic compounds should be made in whole-water samples, but due to their hydrophobicity and strong attraction to organic content these compounds can be found bound to suspended particle matter or in the dissolved fraction. In this work, the extraction of musk compounds was studied in whole-water samples exhibiting different amounts of dissolved organic carbon and suspended particulate matter using polyethersulfone preconcentration technique. Matrix effects in estuarine and wastewater (both influent and effluent) were evaluated for filtered and unfiltered samples. For unfiltered samples, estuarine water exhibited matrix effects <20%, while for effluent it was up to 48% and for influent ranged from 85 to 99%. To compensate matrix effects and determine total concentrations in unfiltered samples, different quantification approaches were tested: the use of deuterated analogues and standard additions. Standard additions provided the best results for unfiltered samples. Finally, filtered and unfiltered samples were analyzed using both polyethersulfone preconcentration and membrane-assisted solvent extraction and results showed a good agreement between the two methods. In both cases unfiltered samples provided concentrations 1.5-2.6 times higher than filtered samples. PMID:25885885

  7. RAPID ANALYSIS OF EMERGENCY URINE AND WATER SAMPLES

    SciTech Connect

    Maxwell, S

    2007-02-26

    There is a need for fast, reliable methods for the determination of actinides and Sr-89/90 analysis on environmental and bioassay samples in response to an emergency radiological incident. The SRS (Savannah River Site) Environmental Bioassay Laboratory participated in the National Institute of Standards and Technology Radiochemistry Intercomparison Program (NRIP-06) and analyzed water and urine samples within 8 hours of receipt. The SRS Environmental Laboratory was the only lab that participated in the program that analyzed these samples for both actinides and Sr-89/90 within the requested 8 hour turnaround time. A new, rapid actinide and strontium 89/90 separation method was used for both urine and water samples. This method uses stacked TEVA Resin{reg_sign}, TRU Resin{reg_sign} and Sr-Resin{reg_sign} cartridges from Eichrom Technologies (Darien, IL, USA) that allows the rapid separation of plutonium (Pu), neptunium (Np), uranium (U), and americium (Am), curium (Cm) and thorium (Th) using a single multi-stage column combined with alpha spectrometry. By using vacuum box cartridge technology and stacked cartridges with rapid flow rates, sample preparation time was minimized. This paper discusses the technology and conditions employed for both water and urine samples and presents the SRS performance data on the NRIP-06 samples.

  8. Microwell enumeration of viable Saprolegniaceae in water samples.

    PubMed

    Thoen, Even; Evensen, Øystein; Skaar, Ida

    2010-01-01

    Existing methods for enumeration of viable Saprolegniaceae propagules in water are laborious, time consuming and prevent examination of large numbers of samples or samples with high spore loads. In the present study a microwell plate (MWP) assay for estimation of Saprolegniaceae in water samples, modified from Hagen (1992), was evaluated. The ability of the assay to recover Saprolegniaceae was assessed by applying it to spore suspensions with four predetermined concentrations, 500-10,000 spores per liter of samples tested. The method also was used to analyze a set of field samples and compare it to a standard filtration method to ascertain its practicability. The MWP assay underestimated the number of spores in the test suspensions with predetermined concentrations. The accuracy of the assay varied with spore concentration, giving the lowest recovery (62.5%) at low spore numbers and the highest (86%) at intermediate concentrations (1000-5000 spores/L) for both isolates and growth media. The findings indicate that spores aggregate with increasing concentration. When applied to field samples the assay clearly distinguished among samples with presumptive differences in spore load and yielded significantly higher counts than the filtration method. The results justify the MWP method foruse in estimation of Saprolegniaceae in water bodies particularly relevant for monitoring of spore load in aquaculture as well as in ecological studies. PMID:20361514

  9. Adsorption of Water on JSC-1A Lunar Simulant Samples

    NASA Technical Reports Server (NTRS)

    Goering, John; Sah, Shweta; Burghaus, Uwe; Street, Kenneth W.

    2008-01-01

    Remote sensing probes sent to the moon in the 1990s indicated that water may exist in areas such as the bottoms of deep, permanently shadowed craters at the lunar poles, buried under regolith. Water is of paramount importance for any lunar exploration and colonization project which would require self-sustainable systems. Therefore, investigating the interaction of water with lunar regolith is pertinent to future exploration. The lunar environment can be approximated in ultra-high vacuum systems such as those used in thermal desorption spectroscopy (TDS). Questions about water dissociation, surface wetting, degree of crystallization, details of water-ice transitions, and cluster formation kinetics can be addressed by TDS. Lunar regolith specimens collected during the Apollo missions are still available though precious, so testing with simulant is required before applying to use lunar regolith samples. Hence, we used for these studies JSC-1a, mostly an aluminosilicate glass and basaltic material containing substantial amounts of plagioclase, some olivine and traces of other minerals. Objectives of this project include: 1) Manufacturing samples using as little raw material as possible, allowing the use of surface chemistry and kinetics tools to determine the feasibility of parallel studies on regolith, and 2) Characterizing the adsorption kinetics of water on the regolith simulant. This has implications for the probability of finding water on the moon and, if present, for recovery techniques. For condensed water films, complex TDS data were obtained containing multiple features, which are related to subtle rearrangements of the water adlayer. Results from JSC-1a TDS studies indicate: 1) Water dissociation on JSC-1a at low exposures, with features detected at temperatures as high as 450 K and 2) The formation of 3D water clusters and a rather porous condensed water film. It appears plausible that the sub- m sized particles act as nucleation centers.

  10. COMPARISON OF GROUND-WATER SAMPLING DEVICES BASED ON EQUILIBRATION OF WATER QUALITY INDICATOR PARAMETERS

    EPA Science Inventory

    The sampling device selected when obtaining ground-water samples can have a significant impact on the representativeness and reproducibility of the sample. his study evaluated several different sampling devices (low speed submersible pump, peristaltic pump, and bladder pump) in t...

  11. UMTRA project water sampling and analysis plan, Salt Lake City, Utah

    SciTech Connect

    Not Available

    1994-06-01

    Surface remedial action was completed at the Salt Lake City, Utah, Uranium Mill Tailings Remedial Action (UMTRA) Project site in the fall of 1987. Results of water sampling for the years 1992 to 1994 indicate that site-related ground water contamination occurs in the shallow unconfined aquifer (the uppermost aquifer). With respect to background ground water quality, contaminated ground water in the shallow, unconfined aquifer has elevated levels of chloride, sodium, sulfate, total dissolved solids, and uranium. No contamination associated with the former tailings pile occurs in levels exceeding background in ground water in the deeper confined aquifer. This document provides the water sampling and analysis plan for ground water monitoring at the former uranium processing site in Salt Lake City, Utah (otherwise known as the ``Vitro`` site, named after the Vitro Chemical Company that operated the mill). All contaminated materials removed from the processing site were relocated and stabilized in a disposal cell near Clive, Utah, some 85 miles west of the Vitro site (known as the ``Clive`` disposal site). No ground water monitoring is being performed at the Clive disposal site, since concurrence of the remedial action plan by the US Nuclear Regulatory Commission and completion of the disposal cell occurred before the US Environmental Protection Agency issued draft ground water standards in 1987 (52 FR 36000) for cleanup, stabilization, and control of residual radioactive materials at the disposal site. In addition, the likelihood of post-closure impact on the ground water is minimal to nonexistent, due to the naturally poor quality of the ground water. Water sampling activities planned for calendar year 1994 consist of sampling ground water from nine monitor wells to assess the migration of contamination within the shallow unconfined aquifer and sampling ground water from two existing monitor wells to assess ground water quality in the confined aquifer.

  12. Supplement to the UMTRA project water sampling and analysis plan, Slick Rock, Colorado

    SciTech Connect

    1995-09-01

    The water sampling and analysis plan (WSAP) provides the regulatory and technical basis for ground water and surface water sampling at the Uranium Mill Tailings Remedial Action (UMTRA) Project Union Carbide (UC) and North Continent (NC) processing sites and the Burro Canyon disposal site near Slick Rock, Colorado. The initial WSAP was finalized in August 1994 and will be completely revised in accordance with the WSAP guidance document (DOE, 1995) in late 1996. This version supplements the initial WSAP, reflects only minor changes in sampling that occurred in 1995, covers sampling scheduled for early 1996, and provides a preliminary projection of the next 5 years of sampling and monitoring activities. Once surface remedial action is completed at the former processing sites, additional and more detailed hydrogeologic characterization may be needed to develop the Ground Water Program conceptual ground water model and proposed compliance strategy. In addition, background ground water quality needs to be clearly defined to ensure that the baseline risk assessment accurately estimated risks from the contaminants of potential concern in contaminated ground water at the UC and NC sites.

  13. Profile sampling to characterize particulate lead risks in potable water.

    PubMed

    Clark, Brandi; Masters, Sheldon; Edwards, Marc

    2014-06-17

    Traditional lead (Pb) profiling, or collecting sequential liters of water that flow from a consumer tap after a stagnation event, has recently received widespread use in understanding sources of Pb in drinking water and risks to consumer health, but has limitations in quantifying particulate Pb risks. A new profiling protocol was developed in which a series of traditional profiles are collected from the same tap at escalating flow rates. The results revealed marked differences in risks of Pb exposure from one consumer home to another as a function of flow rate, with homes grouped into four risk categories with differing flushing requirements and public education to protect consumers. On average, Pb concentrations detected in water at high flow without stagnation were at least three to four times higher than in first draw samples collected at low flow with stagnation, demonstrating a new "worst case" lead release scenario, contrary to the original regulatory assumption that stagnant, first draw samples contain the highest lead concentrations. Testing also revealed that in some cases water samples with visible particulates had much higher Pb than samples without visible particulates, and tests of different sample handling protocols confirmed that some EPA-allowed methods would not quantify as much as 99.9% of the Pb actually present (avg. 27% of Pb not quantified). PMID:24865841

  14. Gas-driven pump for ground-water samples

    USGS Publications Warehouse

    Signor, Donald C.

    1978-01-01

    Observation wells installed for artificial-recharge research and other wells used in different ground-water programs are frequently cased with small-diameter steel pipe. To obtain samples from these small-diameter wells in order to monitor water quality, and to calibrate solute-transport models, a small-diameter pump with unique operating characteristics is required that causes a minimum alternation of samples during field sampling. A small-diameter gas-driven pump was designed and built to obtain water samples from wells of two-inch diameter or larger. The pump is a double-piston type with the following characteristics: (1) The water sample is isolated from the operating gas, (2) no source of electricity is ncessary, (3) operation is continuous, (4) use of compressed gas is efficient, and (5) operation is reliable over extended periods of time. Principles of operation, actual operation techniques, gas-use analyses and operating experience are described. Complete working drawings and a component list are included. Recent modifications and pump construction for high-pressure applications also are described. (Woodard-USGS)

  15. Isotope evidence of hexavalent chromium stability in ground water samples.

    PubMed

    Čadková, Eva; Chrastný, Vladislav

    2015-11-01

    Chromium stable isotopes are of interest in many geochemical studies as a tool to identify Cr(VI) reduction and/or dilution in groundwater aquifers. For such studies the short term stability of Cr(VI) in water samples is required before the laboratory analyses can be carried out. Here the short term stability of Cr(VI) in groundwater samples was studied using an isotope approach. Based on commonly available methods for Cr(VI) stabilization, water samples were filtered and the pH value was adjusted to be equal to or greater than 8 before Cr isotope analysis. Based on our Cr isotope data (expressed as δ(53)CrNIST979), Cr(VI) was found to be unstable over short time periods in anthropogenically contaminated groundwater samples regardless of water treatment (e.g., pH adjustment, different storage temperatures). Based on our laboratory experiments, δ(53)CrNIST979 of the Cr(VI) pool was found to be unstable in the presence of dissolved Fe(II), Mn(IV) and/or SO2. Threshold concentrations of Fe(II) causing Cr(VI) reduction range between 10 mg L(-1) and 100 mg L(-1)and less than 1 mg L(-1) for Mn. Hence our isotope data show that water samples containing Cr(VI) should be processed on-site through anion column chemistry to avoid any isotope shifts. PMID:26037819

  16. A water soluble additive to suppress respirable dust from concrete-cutting chainsaws: a case study.

    PubMed

    Summers, Michael P; Parmigiani, John P

    2015-01-01

    Respirable dust is of particular concern in the construction industry because it contains crystalline silica. Respirable forms of silica are a severe health threat because they heighten the risk of numerous respirable diseases. Concrete cutting, a common work practice in the construction industry, is a major contributor to dust generation. No studies have been found that focus on the dust suppression of concrete-cutting chainsaws, presumably because, during normal operation water is supplied continuously and copiously to the dust generation points. However, there is a desire to better understand dust creation at low water flow rates. In this case study, a water-soluble surfactant additive was used in the chainsaw's water supply. Cutting was performed on a free-standing concrete wall in a covered outdoor lab with a hand-held, gas-powered, concrete-cutting chainsaw. Air was sampled at the operator's lapel, and around the concrete wall to simulate nearby personnel. Two additive concentrations were tested (2.0% and 0.2%), across a range of fluid flow rates (0.38-3.8 Lpm [0.1-1.0 gpm] at 0.38 Lpm [0.1 gpm] increments). Results indicate that when a lower concentration of additive is used exposure levels increase. However, all exposure levels, once adjusted for 3 hours of continuous cutting in an 8-hour work shift, are below the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) of 5 mg/m(3). Estimates were made using trend lines to predict the fluid flow rates that would cause respirable dust exposure to exceed both the OSHA PEL and the American Conference of Governmental Industrial Hygienists (ACGIH®) threshold limit value (TLV). PMID:25714034

  17. UMTRA project water sampling and analysis plan, Durango, Colorado

    SciTech Connect

    Not Available

    1994-01-01

    Surface remedial action has been completed at the Uranium Mill Tailings Remedial Action Project in Durango, Colorado. Contaminated soil and debris have been removed from the former processing site and placed in the Bodo Canyon disposal cell. Ground water at the former uranium mill/tailings site and raffinate pond area has been contaminated by the former milling operations. The ground water at the disposal site was not impacted by the former milling operations at the time of the cell`s construction. Activities for fiscal 1994 involve ground water sampling and site characterization of the disposal site.

  18. Feasibility of additional HTV operation requirement for sample returning capability from the ISS

    NASA Astrophysics Data System (ADS)

    Imada, Takane

    2006-07-01

    HTV (H-II transfer vehicle) is under development in JAXA as a service vehicle which delivers several items up to 6 ton to the ISS (International Space Station), however, it was not expected to have a recovery capability from the ISS. But after the NASA announcement about the Space Shuttle retirement after 2010, it is expected that the sample returning capability from the ISS will be drastically reduced after the retirement. It may also degrade the worth of the ISS as an experimental center on orbit. So, JAXA started the feasibility study about the additional function on HTV to equip a re-entry capsule in it to enable the recovery operation from the ISS. This study shows the preliminary feasibility assessment result of returning capsule in HTV carrier and the feasibility to equip small capsule and jettison system in carrier without major modification or safety impact to the ISS.

  19. Stability of explosives in environmental water and soil samples

    SciTech Connect

    Maskarinec, M.P.; Bayne, C.K.; Johnson, L.H.; Holladay, S.K.; Jenkins, R.A.; Tomkins, B.A.

    1991-01-01

    This report focuses on data generated for the purpose of establishing the stability of HMX, RDX, TNT, and DNT explosives in environmental water and soil samples. The study was carried out over a one year time frame and took into account as many variables as possible within the constraints of budget and time. The objectives of the study were: (1) to provide a data base which could be used to provide guidance on pre-analytical holding times for regulatory purposes; and (2) and to provide a basis for the evaluation of data which is generated outside of the currently allowable holding times for quality assurance purposes. The experimental design consisted of three water samples and three soil samples. The water samples were distilled-in-glass water, a ground water, and surface water. The soil samples were a US Army Toxic and Hazardous Materials Agency soil, a Captina silt loam from Roane County, Tennessee, and a McLaurin sandy loam from Stone County, Mississippi. The analytes consisted of four explosives HMX, RDX, TNT and DNT. Several approaches were taken to estimate the MHTs for each explosive because a standard definition for MHT has not been adopted by the Environmental Protection Agency (EPA). First, a procedure recommended by the American Society for Testing and Materials (ASTM) was modified and applied to the data base. Secondly, a procedure developed by Environmental Science and Engineering (ESE) for the analysis of a similar data base was applied. This report is intended to summarize the findings of the study in such a way as to allow individual decisions to be made regarding the quality of environmental data. The use of the data base may well be different for analyses conducted under RCRA, for example, than for those conducted under NPDES permit requirements. For this reason, the summary statistics for each replicate analysis is presented in the appendices of this report. 18 refs., 4 figs., 14 tabs.

  20. Stability of low levels of perchlorate in drinking water and natural water samples

    USGS Publications Warehouse

    Stetson, S.J.; Wanty, R.B.; Helsel, D.R.; Kalkhoff, S.J.; Macalady, D.L.

    2006-01-01

    Perchlorate ion (ClO4-) is an environmental contaminant of growing concern due to its potential human health effects, impact on aquatic and land animals, and widespread occurrence throughout the United States. The determination of perchlorate cannot normally be carried out in the field. As such, water samples for perchlorate analysis are often shipped to a central laboratory, where they may be stored for a significant period before analysis. The stability of perchlorate ion in various types of commonly encountered water samples has not been generally examined-the effect of such storage is thus not known. In the present study, the long-term stability of perchlorate ion in deionized water, tap water, ground water, and surface water was examined. Sample sets containing approximately 1000, 100, 1.0, and 0.5 ??g l-1 perchlorate ion in deionized water and also in local tap water were formulated. These samples were analyzed by ion chromatography for perchlorate ion concentration against freshly prepared standards every 24 h for the first 7 days, biweekly for the next 4 weeks, and periodically after that for a total of 400 or 610 days for the two lowest concentrations and a total of 428 or 638 days for the high concentrations. Ground and surface water samples containing perchlorate were collected, held and analyzed for perchlorate concentration periodically over at least 360 days. All samples except for the surface water samples were found to be stable for the duration of the study, allowing for holding times of at least 300 days for ground water samples and at least 90 days for surface water samples. ?? 2006 Elsevier B.V. All rights reserved.

  1. An evaluation of drinking water samples treated with alternative disinfectants

    SciTech Connect

    Patterson, K.S.; Lykins, B.W. Jr.; Garner, L.M.

    1995-10-01

    Due to concern over potential human health risks associated with the use of chlorine (Cl{sub 2}) for disinfection of drinking water, many utilities are considering alternative disinfectants. An evaluation is thus needed of the potential risks associated with the use of alternative disinfectants relative to those posed by Cl{sub 2}. At a pilot-scale drinking water plant in Jefferson Parish, LA., two studies were conducted in which clarified and sand filtered Mississippi River water was treated with either ozone (O{sub 3}), monochloramine (NH{sub 2}Cl), Cl{sub 2} or was not disinfected. Ozonated water was also post-disinfected with either NH{sub 2}Cl or Cl{sub 2}, to provide a disinfectant residual. For each treatment stream total organic carbon (TOC), total organic halide (TOX) and microbiological contaminants were determined. XAD resin concentrates were also prepared for mutagenicity testing in the Ames Salmonella assay. Water samples disinfected with O{sub 3} alone had low levels of mutagenic activity, the same as the non-disinfected water. The level of mutagenicity observed following chlorination was approximately twice that observed following treatment with NH{sub 2}Cl. Disinfection with O{sub 3} prior to treatment with either Cl{sub 2} or NH{sub 2}Cl resulted in a significantly lower level of mutagenicity than when either disinfectant was used alone. The concentrations of TOX present in the water samples showed a pattern similar to that of the mutagenicity data. The levels of TOC, by contrast, were similar for all the treatment streams. No significant baterial contamination was observed in water samples treated with either Cl{sub 2} or NH{sub 2}Cl alone or in combination with O{sub 3}, as determined by heterotrophic plate counts. However, O{sub 3} alone did not insure an acceptable level of disinfection at the end of the treatment stream.

  2. Guidelines and techniques for obtaining water samples that accurately represent the water chemistry of an aquifer

    USGS Publications Warehouse

    Claassen, Hans C.

    1982-01-01

    Obtaining ground-water samples that accurately represent the water chemistry of an aquifer is a complex task. Before a ground-water sampling program can be started, an understanding of the kind of chemical data needed and the potential changes in water chemistry resulting from various drilling, well-completion, and sampling techniques is needed. This report provides a basis for such an evaluation and permits a choice of techniques that will result in obtaining the best possible data for the time and money allocated.

  3. THE EMPACT BEACHES: A CASE STUDY IN RECREATIONAL WATER SAMPLING

    EPA Science Inventory

    Various chapters describe sample and experimental design, use of a geometric mean or an arithmetic mean, modeling and forecasting, and risk assessment in relation to monitoring recreational waters for fecal indicators. All of these aspects of monitoring are dependent on the spat...

  4. NEW APPROACHES TO THE PRESERVATION OF CONTAMINANTS IN WATER SAMPLES

    EPA Science Inventory

    The potential of antibiotics, chemical biocides and lytic enzymes in preserving nutrients, biological oxygen demand and oil and grease in water and sewage effluents was studied. Preliminary studies concerning the effect of drugs on cell growth and oxygen utilization in samples st...

  5. FILTRATION OF GROUND WATER SAMPLES FOR METALS ANALYSIS

    EPA Science Inventory

    The filtration of a ground water samples with 0.45 um filters for determination of 'dissolved' metals is not only inaccurate for distinguishing between dissolved and particulate phases, but if used for estimates of mobile contaminant loading in a given aquifer, may result in sign...

  6. SAMPLING STRATEGIES FOR WATER QUALITY IN THE GREAT LAKES

    EPA Science Inventory

    The major goal of this project was to investigate the potential applications of Kalman filtering and modern optimization techniques to the design of sampling strategies for water quality in the Great Lakes. Two representative problems of general limnological interest with conside...

  7. Downhole pumps for water sampling in small diameter wells

    USGS Publications Warehouse

    Koopman, F. C.

    1979-01-01

    The relatively high cost and difficulty in locating a source of pumps for use in obtaining ground-water samples from small-diameter wells has demonstrated a need for this report. Criteria for selection of a pump and pumping equipment to meet specific requirements has been tabulated to assist field personnel in making a selection from commercial sources. (Kosco-USGS)

  8. MICROBIAL SAMPLING VARIABLES AND RECREATIONAL WATER QUALITY STANDARDS

    EPA Science Inventory

    A study was conducted at two beaches on Lake Erie to evaluate the water sampling design for the collection of several microbiological indicator organisms in relation to day, time, and location of collection. The concentrations of these organisms were generally found to vary signi...

  9. Filtration recovery of extracellular DNA from environmental water samples

    EPA Science Inventory

    qPCR methods are able to analyze DNA from microbes within hours of collecting water samples, providing the promptest notification and public awareness possible when unsafe pathogenic levels are reached. Health risk, however, may be overestimated by the presence of extracellular ...

  10. Total Water Content Measurements with an Isokinetic Sampling Probe

    NASA Technical Reports Server (NTRS)

    Reehorst, Andrew L.; Miller, Dean R.; Bidwell, Colin S.

    2010-01-01

    The NASA Glenn Research Center has developed a Total Water Content (TWC) Isokinetic Sampling Probe. Since it is not sensitive to cloud water particle phase nor size, it is particularly attractive to support super-cooled large droplet and high ice water content aircraft icing studies. The instrument is comprised of the Sampling Probe, Sample Flow Control, and Water Vapor Measurement subsystems. Analysis and testing have been conducted on the subsystems to ensure their proper function and accuracy. End-to-end bench testing has also been conducted to ensure the reliability of the entire instrument system. A Stokes Number based collection efficiency correction was developed to correct for probe thickness effects. The authors further discuss the need to ensure that no condensation occurs within the instrument plumbing. Instrument measurements compared to facility calibrations from testing in the NASA Glenn Icing Research Tunnel are presented and discussed. There appears to be liquid water content and droplet size effects in the differences between the two measurement techniques.

  11. Standard reference water samples for rare earth element determinations

    USGS Publications Warehouse

    Verplanck, P.L.; Antweiler, R.C.; Nordstrom, D.K.; Taylor, H.E.

    2001-01-01

    Standard reference water samples (SRWS) were collected from two mine sites, one near Ophir, CO, USA and the other near Redding, CA, USA. The samples were filtered, preserved, and analyzed for rare earth element (REE) concentrations (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) by inductively coupled plasma-mass spectrometry (ICP-MS). These two samples were acid mine waters with elevated concentrations of REEs (0.45-161 ??g/1). Seventeen international laboratories participated in a 'round-robin' chemical analysis program, which made it possible to evaluate the data by robust statistical procedures that are insensitive to outliers. The resulting most probable values are reported. Ten to 15 of the participants also reported values for Ba, Y, and Sc. Field parameters, major ion, and other trace element concentrations, not subject to statistical evaluation, are provided.

  12. Investigations of Sample Stability in Water Chemistry Samples: Implications for the National Aquatic Resource Surveys

    EPA Science Inventory

    Water samples collected for the EPA's National Aquatic Resource Surveys (NARS) typically arrive at an analytical laboratory 2 or 3 days after collection (longer if collected from a remote location), at which point they are stabilized (filtration and/or acid preservation) until an...

  13. A Small Diameter Rosette for Sampling Ice Covered Waters

    NASA Astrophysics Data System (ADS)

    Chayes, D. N.; Smethie, W. M.; Perry, R. S.; Schlosser, P.; Friedrich, R.

    2011-12-01

    A gas tight, small diameter, lightweight rosette, supporting equipment and an effective operational protocol has been developed for aircraft supported sampling of sea water across the Lincoln Sea. The system incorporates a commercial off the shelf CTD electronics (SBE19+ sensor package and SBE33 deck unit) to provide real-time measurement data at the surface. We designed and developed modular water sample units and custom electronics to decode the bottle firing commands and close the sample bottles. For a typical station, we land a ski-equipped deHaviland Twin Otter (DHC-6) aircraft on a suitable piece of sea-ice, drill a 12" diameter hole through the ice next to the cargo door and set up a tent to provide a reasonable working environment over the hole. A small winch with 0.1" diameter single conductor cable is mounted in the aircraft by the cargo door and a tripod supports a sheave above the hole. The CTD module is connected to the end of the wire and the water sampling modules are stacked on top as the system is lowered. For most stations, three sample modules are used to provide 12 four (4) liter sample bottles. Data collected during the down-cast is used to formulate the sampling plan which is executed on the up-cast. The system is powered by a 3,700 Watt, 120VAC gasoline generator. After collection, the sample modules are stored in passively temperature stabilized ice chests during the flight back to the logistics facility at Alert where a broad range of samples are drawn and stored for future analysis. The transport mechanism has a good track record of maintaining water samples within about two degrees of the original collection temperature which minimizes out-gassing. The system has been successfully deployed during a field program each spring starting in 2004 along a transect between the north end of Ellesmere Island (Alert, Nunavut) and the North Pole. During the eight field programs we have taken 48 stations with twelve bottles at most stations (eight at

  14. A new method of snowmelt sampling for water stable isotopes

    USGS Publications Warehouse

    Penna, D.; Ahmad, M.; Birks, S. J.; Bouchaou, L.; Brencic, M.; Butt, S.; Holko, L.; Jeelani, G.; Martinez, D. E.; Melikadze, G.; Shanley, J.B.; Sokratov, S. A.; Stadnyk, T.; Sugimoto, A.; Vreca, P.

    2014-01-01

    We modified a passive capillary sampler (PCS) to collect snowmelt water for isotopic analysis. Past applications of PCSs have been to sample soil water, but the novel aspect of this study was the placement of the PCSs at the ground-snowpack interface to collect snowmelt. We deployed arrays of PCSs at 11 sites in ten partner countries on five continents representing a range of climate and snow cover worldwide. The PCS reliably collected snowmelt at all sites and caused negligible evaporative fractionation effects in the samples. PCS is low-cost, easy to install, and collects a representative integrated snowmelt sample throughout the melt season or at the melt event scale. Unlike snow cores, the PCS collects the water that would actually infiltrate the soil; thus, its isotopic composition is appropriate to use for tracing snowmelt water through the hydrologic cycle. The purpose of this Briefing is to show the potential advantages of PCSs and recommend guidelines for constructing and installing them based on our preliminary results from two snowmelt seasons.

  15. Determination of rare earth elements in natural water samples - A review of sample separation, preconcentration and direct methodologies.

    PubMed

    Fisher, Andrew; Kara, Derya

    2016-09-01

    This review discusses and compares the methods given for the determination of rare earth elements (REE) in natural water samples, including sea, river, lake, tap, ground and waste waters as well as Antarctic ice. Since REE are at very low concentrations in natural waters, numerous different preconcentration methods have been proposed to enable their measurement. These include liquid liquid extraction, dispersive liquid-liquid micro-extraction and solidified floating drop micro-extraction. In addition to liquid-liquid extraction methods, solid phase extraction using commercial resins, resins made in-house, silica-based exchange materials and other solid media is also discussed. These and other techniques such as precipitation/co-precipitation and flotation are compared in terms of speed, preconcentration factors achieved, precision, accuracy and limits of detection (LOD). Some papers have discussed the direct determination of REE in these sample types. Some have used specialised sample introduction systems such as ultrasonic nebulization whereas others have used a standard sample introduction system coupled with inductively coupled plasma mass spectrometry (ICP-MS) detection. These direct methods have also been discussed and compared. PMID:27543012

  16. Covalent Functionalization of Fluorinated Graphene and Subsequent Application as Water-based Lubricant Additive.

    PubMed

    Ye, Xiangyuan; Ma, Limin; Yang, Zhigang; Wang, Jinqing; Wang, Honggang; Yang, Shengrong

    2016-03-23

    Although the fluorinated graphene (FG) possesses numerous excellent properties, it can not be really applied in aqueous environments due to its high hydrophobicity. Therefore, how to achieve hydrophilic FG is a challenge. Here, a method of solvent-free urea melt synthesis is developed to prepare the hydrophilic urea-modified FG (UFG). Some characterizations via transmission electron microscopy (TEM), atomic force microscopy (AFM), Fourier transfer infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and thermo gravimetric analysis (TGA) demonstrate that the urea molecules can covalently functionalize the FG and the hydrophilic UFG can be prepared. According to the tribological tests run on an optimal-SRV-I reciprocation friction tester, it can be found that the antiwear ability of water can be largely improved by adding the appropriate UFG. When the concentration of UFG aqueous dispersion is 1 mg/mL, the sample of UFG-1 has the best antiwear ability with a 64.4% decrease of wear rate compared with that of the pure water (UFG-0), demonstrating the prepared UFG can be used as a novel and effective water-based lubricant additive. PMID:26923174

  17. Water vapor measurement system in global atmospheric sampling program, appendix

    NASA Technical Reports Server (NTRS)

    Englund, D. R.; Dudzinski, T. J.

    1982-01-01

    The water vapor measurement system used in the NASA Global Atmospheric Sampling Program (GASP) is described. The system used a modified version of a commercially available dew/frostpoint hygrometer with a thermoelectrically cooled mirror sensor. The modifications extended the range of the hygrometer to enable air sample measurements with frostpoint temperatures down to -80 C at altitudes of 6 to 13 km. Other modifications were made to permit automatic, unattended operation in an aircraft environment. This report described the hygrometer, its integration with the GASP system, its calibration, and operational aspects including measurement errors. The estimated uncertainty of the dew/frostpoint measurements was + or - 1.7 Celsius.

  18. RAPID SEPARATION METHOD FOR EMERGENCY WATER AND URINE SAMPLES

    SciTech Connect

    Maxwell, S.; Culligan, B.

    2008-08-27

    The Savannah River Site Environmental Bioassay Lab participated in the 2008 NRIP Emergency Response program administered by the National Institute for Standards and Technology (NIST) in May, 2008. A new rapid column separation method was used for analysis of actinides and {sup 90}Sr the NRIP 2008 emergency water and urine samples. Significant method improvements were applied to reduce analytical times. As a result, much faster analysis times were achieved, less than 3 hours for determination of {sup 90}Sr and 3-4 hours for actinides. This represents a 25%-33% improvement in analysis times from NRIP 2007 and a {approx}100% improvement compared to NRIP 2006 report times. Column flow rates were increased by a factor of two, with no significant adverse impact on the method performance. Larger sample aliquots, shorter count times, faster cerium fluoride microprecipitation and streamlined calcium phosphate precipitation were also employed. Based on initial feedback from NIST, the SRS Environmental Bioassay Lab had the most rapid analysis times for actinides and {sup 90}Sr analyses for NRIP 2008 emergency urine samples. High levels of potential matrix interferences may be present in emergency samples and rugged methods are essential. Extremely high levels of {sup 210}Po were found to have an adverse effect on the uranium results for the NRIP-08 urine samples, while uranium results for NRIP-08 water samples were not affected. This problem, which was not observed for NRIP-06 or NRIP-07 urine samples, was resolved by using an enhanced {sup 210}Po removal step, which will be described.

  19. Fishing in the Water: Effect of Sampled Water Volume on Environmental DNA-Based Detection of Macroinvertebrates.

    PubMed

    Mächler, Elvira; Deiner, Kristy; Spahn, Fabienne; Altermatt, Florian

    2016-01-01

    Accurate detection of organisms is crucial for the effective management of threatened and invasive species because false detections directly affect the implementation of management actions. The use of environmental DNA (eDNA) as a species detection tool is in a rapid development stage; however, concerns about accurate detections using eDNA have been raised. We evaluated the effect of sampled water volume (0.25 to 2 L) on the detection rate for three macroinvertebrate species. Additionally, we tested (depending on the sampled water volume) what amount of total extracted DNA should be screened to reduce uncertainty in detections. We found that all three species were detected in all volumes of water. Surprisingly, however, only one species had a positive relationship between an increased sample volume and an increase in the detection rate. We conclude that the optimal sample volume might depend on the species-habitat combination and should be tested for the system where management actions are warranted. Nevertheless, we minimally recommend sampling water volumes of 1 L and screening at least 14 μL of extracted eDNA for each sample to reduce uncertainty in detections when studying macroinvertebrates in rivers and using our molecular workflow. PMID:26560432

  20. An opacity-sampled treatment of water vapor

    NASA Technical Reports Server (NTRS)

    Alexander, David R.; Augason, Gordon C.; Johnson, Hollis R.

    1989-01-01

    Although the bands of H2O are strong in the spectra of cool stars and calculations have repeatedly demonstrated their significance as opacity sources, only approximate opacities are currently available, due both to the difficulty of accounting for the millions of lines involved and to the inadequacy of laboratory and theoretical data. To overcome these obstacles, a new treatment is presented, based upon a statistical representation of the water vapor spectrum derived from available laboratory data. This statistical spectrum of water vapor employs an exponential distribution of line strengths and random positions of lines whose overall properties are forced to reproduce the mean opacities observed in the laboratory. The resultant data set is then treated by the opacity-sampling method exactly as are all other lines, both molecular and atomic. Significant differences are found between the results of this improved treatment and the results obtained with previous treatments of water-vapor opacity.

  1. LC-MS/MS determination of tralopyril in water samples.

    PubMed

    Oliveira, Isabel B; Schönenberger, René; Barroso, Carlos M; Suter, Marc J-F

    2016-02-01

    A targeted analytical method was established to determine tralopyril (4-bromo-2-(4-chlorophenyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile) in water. This compound has been recently introduced as a biocide in ship antifouling paints, becoming a potential new environmental contaminant. The method presented here allows for the first time the direct determination of tralopyril in environmental samples without the need of a pre-concentration step. The injected sample is separated by a 30 min HPLC-gradient on a reversed phase column and the compound identified and quantified by negative ion LC-MS/MS. Tralopyril solutions in DMSO, seawater, river Glatt water and E3 medium (used for zebrafish experiments) were analysed to demonstrate the applicability of the method. The method provides good retention time reproducibility and a quantitation limit (LOQ) of 0.025 μg L(-1) for DMSO, seawater and E3 exposure medium and 0.05 μg L(-1) for river Glatt water. Calculated tralopyril half-lives were 6.1 h for seawater, 8.1 h for river Glatt water and 7.4 h for E3 medium at 18 °C. PMID:26694794

  2. GROUND WATER SAMPLING OF VOCS IN THE WATER/CAPILLARY FRINGE AREA FOR VAPOR INTRUSION ASSESSMENT

    EPA Science Inventory

    Vapor intrusion has recently been considered a major pathway for increased indoor air contamination from certain volatile organic contaminants (VOCs). The recent Draft EPA Subsurface Vapor Intrusion Guidance Document states that ground water samples should be obtained from the u...

  3. Evidence That Certain Waste Tank Headspace Vapor Samples Were Contaminated by Semivolatile Polymer Additives

    SciTech Connect

    Huckaby, James L.

    2006-02-09

    Vapor samples collected from the headspaces of the Hanford Site high-level radioactive waste tanks in 1994 and 1995 using the Vapor Sampling System (VSS) were reported to contain trace levels of phthalates, antioxidants, and certain other industrial chemicals that did not have a logical origin in the waste. This report examines the evidence these chemicals were sampling artifacts (contamination) and identifies the chemicals reported as headspace constituents that may instead have been contaminants. Specific recommendations are given regarding the marking of certain chemicals as suspect on the basis they were sampling manifold contaminants.

  4. EPA GROUND WATER ISSUE: Ground Water Sample Preservation at ISCO Sites – Recommended Guidelines

    EPA Science Inventory

    In-situ chemical oxidation (ISCO) involves the introduction of a chemical oxidant into the subsurface for the purpose of transforming ground water contaminants into harmless byproducts. Due to oxidant persistence, ground water samples collected at hazardous waste sites may contai...

  5. Using high frequency water quality data to assess sampling strategies for the EU Water Framework Directive

    NASA Astrophysics Data System (ADS)

    Skeffington, R. A.; Halliday, S. J.; Wade, A. J.; Bowes, M. J.; Loewenthal, M.

    2015-01-01

    The EU Water Framework Directive (WFD) requires that the ecological and chemical status of water bodies in Europe should be assessed, and action taken where possible to ensure that at least "good" quality is attained in each case by 2015. This paper is concerned with the accuracy and precision with which chemical status in rivers can be measured given certain sampling strategies, and how this can be improved. High frequency (hourly) chemical data from four rivers in southern England were subsampled to simulate different sampling strategies for four parameters used for WFD classification: dissolved phosphorus, dissolved oxygen, pH and water temperature. These data sub-sets were then used to calculate the WFD classification for each site. Monthly sampling was less precise than weekly sampling, but the effect on WFD classification depended on the closeness of the range of concentrations to the class boundaries. In some cases, monthly sampling for a year could result in the same water body being assigned to one of 3 or 4 WFD classes with 95% confidence, whereas with weekly sampling this was 1 or 2 classes for the same cases. In the most extreme case, random sampling effects could result in the same water body being assigned to any of the 5 WFD quality classes. The width of the weekly sampled confidence intervals was about 33% that of the monthly for P species and pH, about 50% for dissolved oxygen, and about 67% for water temperature. For water temperature, which is assessed as the 98th percentile in the UK, monthly sampling biases the mean downwards by about 1 °C compared to the true value, due to problems of assessing high percentiles with limited data. Confining sampling to the working week compared to all seven days made little difference, but a modest improvement in precision could be obtained by sampling at the same time of day within a 3 h time window, and this is recommended. For parameters with a strong diel variation, such as dissolved oxygen, the value

  6. Solventless and solvent-minimized sample preparation techniques for determining currently used pesticides in water samples: a review.

    PubMed

    Tankiewicz, Maciej; Fenik, Jolanta; Biziuk, Marek

    2011-10-30

    The intensification of agriculture means that increasing amounts of toxic organic and inorganic compounds are entering the environment. The pesticides generally applied nowadays are regarded as some of the most dangerous contaminants of the environment. Their presence in the environment, especially in water, is hazardous because they cause human beings to become more susceptible to disease. For these reasons, it is essential to monitor pesticide residues in the environment with the aid of all accessible analytical methods. The analysis of samples for the presence of pesticides is problematic, because of the laborious and time-consuming operations involved in preparing samples for analysis, which themselves may be a source of additional contaminations and errors. To date, it has been standard practice to use large quantities of organic solvents in the sample preparation process; but as these solvents are themselves hazardous, solventless and solvent-minimized techniques are coming into use. This paper discusses the most commonly used over the last 15 years sample preparation techniques for monitoring organophosphorus and organonitrogen pesticides residue in water samples. Furthermore, a significant trend in sample preparation, in accordance with the principles of 'Green Chemistry' is the simplification, miniaturization and automation of analytical techniques. In view of this aspect, several novel techniques are being developed in order to reduce the analysis step, increase the sample throughput and to improve the quality and the sensitivity of analytical methods. The paper describes extraction techniques requiring the use of solvents - liquid-liquid extraction (LLE) and its modifications, membrane extraction techniques, hollow fibre-protected two-phase solvent microextraction, liquid phase microextraction based on the solidification of a floating organic drop (LPME-SFO), solid-phase extraction (SPE) and single-drop microextraction (SDME) - as well as solvent

  7. Arsenic-related water quality with depth and water quality of well-head samples from production wells, Oklahoma, 2008

    USGS Publications Warehouse

    Becker, Carol J.; Smith, S. Jerrod; Greer, James R.; Smith, Kevin A.

    2010-01-01

    The U.S. Geological Survey well profiler was used to describe arsenic-related water quality with well depth and identify zones yielding water with high arsenic concentrations in two production wells in central and western Oklahoma that yield water from the Permian-aged Garber-Wellington and Rush Springs aquifers, respectively. In addition, well-head samples were collected from 12 production wells yielding water with historically large concentrations of arsenic (greater than 10 micrograms per liter) from the Garber-Wellington aquifer, Rush Springs aquifer, and two minor aquifers: the Arbuckle-Timbered Hills aquifer in southern Oklahoma and a Permian-aged undefined aquifer in north-central Oklahoma. Three depth-dependent samples from a production well in the Rush Springs aquifer had similar water-quality characteristics to the well-head sample and did not show any substantial changes with depth. However, slightly larger arsenic concentrations in the two deepest depth-dependent samples indicate the zones yielding noncompliant arsenic concentrations are below the shallowest sampled depth. Five depth-dependent samples from a production well in the Garber-Wellington aquifer showed increases in arsenic concentrations with depth. Well-bore travel-time information and water-quality data from depth-dependent and well-head samples showed that most arsenic contaminated water (about 63 percent) was entering the borehole from perforations adjacent to or below the shroud that overlaid the pump. Arsenic concentrations ranged from 10.4 to 124 micrograms per liter in 11 of the 12 production wells sampled at the well head, exceeding the maximum contaminant level of 10 micrograms per liter for drinking water. pH values of the 12 well-head samples ranged from 6.9 to 9. Seven production wells in the Garber-Wellington aquifer had the largest arsenic concentrations ranging from 18.5 to 124 micrograms per liter. Large arsenic concentrations (10.4-18.5) and near neutral to slightly alkaline

  8. Sample preservation for the analysis of antibiotics in water.

    PubMed

    Llorca, Marta; Gros, Meritxell; Rodríguez-Mozaz, Sara; Barceló, Damià

    2014-11-21

    This paper describes a stability study performed for 56 antibiotics belonging to 9 different groups--macrolides, tetracyclines, fluoroquinolones, quinolones, penicillins, cephalosporines, lincosamides, sulfonamides and nitroimidazole antibiotics--in purified water samples fortified with the selected compounds at 10 ng/ml. For this purpose, three different sample preservation modes were tested with the aim of avoiding biotic and abiotic degradation: (i) storage at -20°C, (ii) storage at -20°C with 0.1% of EDTA and (iii) pre-concentration in a solid phase extraction cartridge (SPE), which was afterwards stored at -20°C. Concentrations of antibiotics in the samples preserved using the different protocols were monitored after 0, 1, 2 and 12 weeks. The results showed that, for the accurate determination of all compounds they should be analyzed right after sampling. However, if this is not possible, most of the antibiotics can be analyzed within the 1st week after sampling and preservation at -20°C (with or without EDTA) or in a SPE cartridges at -20°C. Nonetheless, some antibiotics found extensively in the environment, such as sulfamethoxazole, ciprofloxacin, ofloxacin, erythromycin, azithromycin and clarithromycin exhibited low stability after 1 week preservation and, therefore, they should be analyzed within this time. PMID:25441070

  9. Asotin Creek ISCO Water Sample Data Summary: Water Year 2002, Annual Report 2001-2002.

    SciTech Connect

    Peterson, Stacia

    2003-08-01

    The Pomeroy Ranger District operates 3 automated water samplers (ISCOs) in the Asotin Creek drainage in cooperation with the Asotin Model Watershed. The samplers are located on Asotin Creek: Asotin Creek at the mouth, Asotin Creek at Koch site, and South Fork Asotin Creek above the forks. At the end of Water Year (WY) 2001 we decided to sample from Oct. 1 through June 30 of each water year. This decision was based on the difficulty of obtaining good low flow samples, since the shallow depth of water often meant that instrument intakes were on the bed of the river and samples were contaminated with bed sediments. The greatest portion of suspended sediment is transported during the higher flows of fall and especially during the spring snow runoff period, and sampling the shorter season should allow characterization of the sediment load of the river. The ISCO water samplers collected a daily composite sample of 4 samples per day into one bottle at 6-hour intervals until late March when they were reprogrammed to collect 3 samples per day at 8-hour intervals. This was done to reduce battery use since battery failure had become an ongoing problem. The water is picked up on 24-day cycles and brought to the Forest Service Water Lab in Pendleton, OR. The samples are analyzed for total suspended solids (TSS), conductivity, and turbidity. A total dissolved solids value is estimated based on conductivity. The USGS gage, Asotin Creek at the mouth, No.13335050 has been discontinued and there are no discharge records available for this period.

  10. Feed additives diclazuril and nicarbazin in egg and liver samples from Croatian farms.

    PubMed

    Bilandžić, Nina; Dolenc, Jožica; Gačnik, Ksenija Šinigoj; Varenina, Ivana; Kolanović, Božica Solomun

    2013-01-01

    In total 307 egg and 275 liver samples were examined for nicarbazin and 365 eggs for diclazuril over a 30-month period. Enzyme-linked immunosorbent assay methods used for quantification were validated according to European Commission Decision 2002/657/EC. Non-compliant samples were confirmed by LC-MS/MS. Mean diclazuril concentrations in egg samples were 0.31 µg kg⁻¹, which is below the MRL. In only one egg sample, 2.26 µg kg⁻¹ was determined by enzyme-linked immunosorbent assay, although confirmation by LC-MS/MS gave a value of 1.6 µg kg(-1). Mean nicarbazin levels determined were 1.85 µg kg⁻¹ in egg and 21.1 µg kg⁻¹ in liver samples. Four samples, one egg and three livers, yielded elevated concentrations of nicarbazin, but only in the egg sample the LC-MS/MS method confirmed nicarbazin (106 µg kg⁻¹) above the MRL value. PMID:24779872

  11. Adsorption of Water on Simulated Moon Dust Samples

    NASA Technical Reports Server (NTRS)

    Goering, John P.; Sah, Shweta; Burghaus, Uwe; Street, Kenneth W., Jr.

    2008-01-01

    A lunar regolith simulant dust sample (JSC-1a) supported on a silica wafer (SiO2/Si(111)) has been characterized by scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX), and Auger electron spectroscopy (AES). The adsorption kinetics of water has been studied primarily by thermal desorption spectroscopy (TDS) and also by collecting isothermal adsorption transients. The support has been characterized by water TDS. JSC-1a consists mostly of aluminosilicate glass and other minerals containing Fe, Na, Ca, and Mg. The particle sizes span the range from a few microns up to 100 microns. At small exposures, H2O TDS is characterized by broad (100 to 450 K) structures; at large exposures distinct TDS peaks emerge that are assigned to amorphous solid water (145 K) and crystalline ice (165 K). Water dissociates on JSC-1a at small exposures but not on the bare silica support. It appears that rather porous condensed ice layers form at large exposures. At thermal impact energies, the initial adsorption probability amounts to 0.92+/-0.05.

  12. Prototype spectral analysis of water samples for monitoring and treatment of public water resources

    NASA Astrophysics Data System (ADS)

    Lambrakos, S. G.; Lee, M.; Yapijakis, C.; Ramsey, L. S.; Huang, L.; Shabaev, A.; Massa, L.

    2014-06-01

    Experimental measurements conducted in the laboratory, involving hyperspectral analysis of water samples taken from public water resources in the New York City metro area, have motivated a reevaluation of issues concerning the potential application of this type of analysis for water monitoring, treatment and evaluation prior to filtration. One issue concerns hyperspectral monitoring of contaminants with respect to types and relative concentrations. This implies a need for better understanding the statistical profiles of water contaminants in terms of spatial-temporal distributions of electromagnetic absorption spectra ranging from the ultraviolet to infrared, which are associated with specific water resources. This issue also implies the need for establishing correlations between hyperspectral signatures and types of contaminants to be found within specific water resources. Another issue concerns the use of absorption spectra for determining changes in chemical and physical characteristics of contaminants after application of water treatments in order to determine levels of toxicity with respect to the environment.

  13. UMTRA Project water sampling and analysis plan, Salt Lake City, Utah. Revision 1

    SciTech Connect

    1995-06-01

    This water sampling and analysis plan describes planned, routine ground water sampling activities at the US Department of Energy Uranium Mill Tailings Remedial Action Project site in Salt Lake City, Utah. This plan identifies and justifies sampling locations, analytical parameters, detection limits, and sampling frequencies for routine monitoring of ground water, sediments, and surface waters at monitoring stations on the site.

  14. Methods for sampling fish communities as part of the National Water-Quality Assessment Program

    USGS Publications Warehouse

    Meador, M.R.; Cuffney, T.F.; Gurtz, M.E.

    1993-01-01

    Fish community structure is characterized in the U.S. Geological Survey's National Water-Quality Assessment Program as part of an integrated physical, chemical, and biological assessment of the Nation's water quality. The objective of the National Water-Quality Assessment characterization of fish community structure is to relate fish community characteristics to physical, chemical, and other biological factors to assess water-quality conditions. To accomplish this, fish community structure is described at sites representing selected environmental settings. In addition, spatial and temporal patterns in fish community structure are examined at local, regional, and national levels. A representative sample of the fish community is collected by sampling a stream reach using two complementary methods. The primary collection method is electrofishing using backpack, towed, or boat-operated electrofishing gear; seining is a secondary technique. Other secondary techniques may be substituted after careful consideration of sampling efficiency and consultation with local fish ecologists. Before fish sampling is conducted, careful consideration must be given to collecting permits; protecting endangered, threatened, and special-concern species; and coordinating sampling efforts with other fish ecologists. After the sample is collected, individual fish are identified to species by ichthyologists. Length and weight measurements are taken, and the presence of external anomalies are recorded.

  15. Water isotopic ratios from a continuously melted ice core sample

    NASA Astrophysics Data System (ADS)

    Gkinis, V.; Popp, T. J.; Blunier, T.; Bigler, M.; Schüpbach, S.; Kettner, E.; Johnsen, S. J.

    2011-11-01

    A new technique for on-line high resolution isotopic analysis of liquid water, tailored for ice core studies is presented. We built an interface between a Wavelength Scanned Cavity Ring Down Spectrometer (WS-CRDS) purchased from Picarro Inc. and a Continuous Flow Analysis (CFA) system. The system offers the possibility to perform simultaneuous water isotopic analysis of δ18O and δD on a continuous stream of liquid water as generated from a continuously melted ice rod. Injection of sub μl amounts of liquid water is achieved by pumping sample through a fused silica capillary and instantaneously vaporizing it with 100% efficiency in a~home made oven at a temperature of 170 °C. A calibration procedure allows for proper reporting of the data on the VSMOW-SLAP scale. We apply the necessary corrections based on the assessed performance of the system regarding instrumental drifts and dependance on the water concentration in the optical cavity. The melt rates are monitored in order to assign a depth scale to the measured isotopic profiles. Application of spectral methods yields the combined uncertainty of the system at below 0.1‰ and 0.5‰ for δ18O and δD, respectively. This performance is comparable to that achieved with mass spectrometry. Dispersion of the sample in the transfer lines limits the temporal resolution of the technique. In this work we investigate and assess these dispersion effects. By using an optimal filtering method we show how the measured profiles can be corrected for the smoothing effects resulting from the sample dispersion. Considering the significant advantages the technique offers, i.e. simultaneuous measurement of δ18O and δD, potentially in combination with chemical components that are traditionally measured on CFA systems, notable reduction on analysis time and power consumption, we consider it as an alternative to traditional isotope ratio mass spectrometry with the possibility to be deployed for field ice core studies. We present

  16. Long-term nitrogen additions and the intrinsic water-use efficiency of boreal Scots pine.

    NASA Astrophysics Data System (ADS)

    Marshall, John; Wallin, Göran; Linder, Sune; Lundmark, Tomas; Näsholm, Torgny

    2015-04-01

    Nitrogen fertilization nearly always increases productivity in boreal forests, at least in terms of wood production, but it is unclear how. In a mature (80 yrs. old) Scots pine forest in northern Sweden, we tested the extent to which nitrogen fertilization increased intrinsic photosynthetic water-use efficiency. We measured δ13C both discretely, in biweekly phloem sampling, and continuously, by monitoring of bole respiration. The original experiment was designed as a test of eddy covariance methods and is not therefore strictly replicated. Nonetheless, we compared phloem contents among fifteen trees from each plot and stem respiration from four per plot. The treatments included addition of 100 kg N/ha for eight years and a control. Phloem contents have the advantage of integrating over the whole canopy and undergoing complete and rapid turnover. Their disadvantage is that some have observed isotopic drift with transport down the length of the stem, presumably as a result of preferential export and/or reloading. We also measured the isotopic composition of stem respiration from four trees on each plot using a Picarro G1101-I CRDS attached to the vent flow from a continuous gas-exchange system. We detected consistent differences in δ13C between the treatments in phloem contents. Within each treatment, the phloem δ13C was negatively correlated with antecedent temperature (R2= 0.65) and no other measured climate variable. The isotopic composition of stem CO2 efflux will be compared to that of phloem contents. However, when converted to intrinsic water-use efficiency, the increase amounted to only about 4%. This is a small relative to the near doubling in wood production. Although we were able to detect a clear and consistent increase in water-use efficiency with N-fertilization, it constitutes but a minor cause of the observed increase in wood production.

  17. THE PERSISTENCE OF MYCOBACTERIUM AVIUM IN A DRINKING WATER SYSTEM AFTER THE ADDITION OF FILTRATION

    EPA Science Inventory

    Drinking water is increasingly recognized as a major source of pathogenic nontuberculous mycobacteria (NTM) associated with human infection. Our goal was to determine if the prevalence of NTM would decrease after the addition of filtration treatment to an unfiltered surface water...

  18. Enhancing water removal from whole stillage by enzyme addition during fermentation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The removal of water from coproducts in the fuel ethanol process requires a significant energy input. In this study, the addition of cell-wall-degrading enzymes was investigated to determine whether or not the enzymes could reduce the amount of water bound within the wet grains. This would have the ...

  19. Analysis of native water, bed material, and elutriate samples of major Louisiana waterways, 1975

    USGS Publications Warehouse

    Demas, Charles R.

    1976-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, conducted a series of elutriate studies in selected reaches of major navigable waterways of Louisiana. As defined by the U.S. Environmental Protection Agency, an elutriate is the supernatant resulting from the vigorous 30-minute shaking of one part bottom sediment from the dredging site with four parts water (vol/vol) collected from the dredging site followed by one hour settling time and appropriate centrifugation and a 0.45-micron filtration. The elutriate studies were initiated to evaluate possible environmental effects of proposed dredging activities in selected reaches of Louisiana waterways. The waterways investigated were the Mississippi River-Gulf Outlet, Breton Sound, Mississippi River downstream from Baton Rouge, Bayou Long, Intracoastal Waterway (east and west of the Harvey Canal), Three Rivers area, Ouachita River, Barataria Bay, Houma Navigation Canal, Atchafalaya Bay (Ship Channel), Berwick Bay, Intracoastal Waterway (Port Allen to Morgan City), Petite Anse area, and Calcasieu River and Ship Channel. The Geological Survey collected 227 samples of native water and bed (bottom) material from 130 different sites. These samples (as well as elutriates prepared from mixtures of native water and bed material) were analyzed for selected metal, pesticide, nutrient, and organic constituents. An additional 116 bed samples collected at 58 sites were analyzed for selected pesticides; and 4 additional native-water samples from 2 sites were analyzed for selected metal pesticide, nutrient, and organic constituents. (Woodard-USGS)

  20. Thermal behavior of water confined in micro porous of clay mineral at additional pressure.

    NASA Astrophysics Data System (ADS)

    Ito, Y.; Takemura, T.; Fujimori, H.; Nagoe, A.; Sugimoto, T.

    2014-12-01

    Water is the most familiar substance. However water has specific properties that has a crystal structure of a dozen and density of that is maximum at 277.15 K. Therefore it understands various natural phenomena to study physical properties of water. Oodo et al study physical properties of water confined in silica gel [1]. They indicate that melting point of water confined in silica gel decrease with decreasing pore size of silica gel. Also in case that pore size is less than 2 nm, water confined in silica gel is unfreezing water at low temperature. It is considered that effect of pore size prevent crystal growth of water. Therefore we are interested in water confined in clay minerals. Clay minerals have a number of water conditions. Also it is thought that water confined in clay minerals show different physical behavior to exist the domain where change with various effect. Therefore we studied a thermal properties and phase behavior of absorption water in clay minerals. In addition, we analyzed the changes in the thermal behavior of absorption water due to the effect of earth pressure that was an environmental factor in the ground. [1] Oodo & Fujimori, J. Non-Cryst. Solids, 357 (2011) 683.

  1. An experiment in representative ground-water sampling for water- quality analysis

    USGS Publications Warehouse

    Huntzinger, T.L.; Stullken, L.E.

    1988-01-01

    Obtaining a sample of groundwater that accurately represents the concentration of a chemical constituent in an aquifer is an important aspect of groundwater-quality studies. Varying aquifer and constituent properties may cause chemical constituents to move within selectively separate parts of the aquifer. An experiment was conducted in an agricultural region in south-central Kansas to address questions related to representative sample collection. Concentrations of selected constituents in samples taken from observation wells completed in the upper part of the aquifer were compared to concentrations in samples taken from irrigation wells to determine if there was a significant difference. Water in all wells sampled was a calcium bicarbonate type with more than 200 mg/L hardness and about 200 mg/L alkalinity. Sodium concentrations were also quite large (about 40 mg/L). There was a significant difference in the nitrite-plus-nitrate concentrations between samples from observation and irrigation wells. The median concentration of nitrite plus nitrate in water from observation wells was 5.7 mg/L compared to 3.4 mg/L in water from irrigation wells. The differences in concentrations of calcium, magnesium, and sodium (larger in water from irrigation wells) were significant at the 78% confidence level but not at the 97% confidence level. Concentrations of the herbicide, atrazine, were less than the detection limit of 0.1 micrograms/L in all but one well. (USGS)

  2. Rapid and Sensitive Voltammetric Determination of Aclonifen in Water Samples.

    PubMed

    Guziejewski, Dariusz; Smarzewska, Sylwia; Skowron, Monika; Ciesielski, Witold; Nosal-Wiercinłska, Agnieszka; Skrzypek, Slawomira

    2016-01-01

    This paper presents the use of square wave voltammetry (SWV) and square wave adsorptive stripping voltammetry (SWAdSV) in conjunction with a cyclic renewable silver amalgam film electrode (Hg(Ag)FE) for the determination of aclonifen in spiked water samples. A reduction peak at -0.65 V versus Ag/AgCl was obtained in the selected buffer (borax buffer with pH 9.2), exhibiting the characteristics of an irreversible reaction. The effect of square wave (SW) frequency, SW amplitude and step potential, as well as accumulation parameters (time and potential) were studied to select the optimal experimental conditions. The calibration curve was linear in the aclonifen concentration range from 1.0×10(-7) to 1.0×10(-6) mol L(-1) and from 1.0×10(-8) to1.0×10(-7) mol L(-1) for SWV and SWAdSV, respectively. The detection and quantification limits were found to be 3.1×10(-8) mol L(-1); 1.0×10(-7) mol L(-1) and 2.9×10(-9) mol L(-1); 9.6×10(-9) mol L-1 for SWV and SWAdSV, respectively. The proposed method was applied successfully in the determination of aclonifen in spiked water samples. The developed procedure can be adequate at least for screening purposes, where positive results should be confirmed by more selective method. PMID:26970782

  3. Olefin Metathesis Reaction in Water and in Air Improved by Supramolecular Additives.

    PubMed

    Tomasek, Jasmine; Seßler, Miriam; Gröger, Harald; Schatz, Jürgen

    2015-01-01

    A range of water-immiscible commercially available Grubbs-type precatalysts can be used in ring-closing olefin metathesis reaction in high yields. The synthetic transformation is possible in pure water under ambient conditions. Sulfocalixarenes can help to boost the reactivity of the metathesis reaction by catalyst activation, improved mass transfer, and solubility of reactants in the aqueous reaction media. Additionally, the use of supramolecular additives allows lower catalyst loadings, but still high activity in pure water under aerobic conditions. PMID:26506329

  4. Toward a mechanistic understanding of the effect of biochar addition on soil water retention

    NASA Astrophysics Data System (ADS)

    Yi, S.; Chang, N.; Guo, M.; Imhoff, P. T.

    2014-12-01

    Biochar (BC) is a carbon-rich product produced by thermal degradation of biomass in an oxygen-free environment, whose application to sediment is said to improve water retention. However, BC produced from different feedstocks and pyrolyzed at different temperatures have distinct properties, which may alter water retention in ways difficult to predict a priori. Our goal is to develop a mechanistic understanding of BC addition on water retention by examining the impact of BC from two feedstocks, poultry litter (PL) and hardwood (HW), on the soil-water retention curves (SWRC) of a uniform sand and a sandy loam (SL). For experiments with sand, BC and sand were sieved to the same particle size (~ 0.547 mm) to minimize effects of BC addition on particle size distribution. Experiments with SL contained the same sieved BC. PL and HW bicohars were added at 2 and 7% (w/w), and water retention was measured from 0 to -4.38 × 106 cm-H2O. Both BCs increased porosities for sand and SL, up to 39 and 13% for sand and SL, respectively, with 7% HW BC addition. The primary cause for these increases was the internal porosity of BC particles. While the matric potential for air-entry was unchanged with BC addition, BC amendment increased water retention for sand and SL in the capillary region (0 to -15,000 cm-H2O) by an average of 26 and 33 % for 7% PL and HW BC in sand, respectively, but only 7 and 14 % for 7% PL and HW BC in SL. The most dramatic influence of BC amendment on water retention occurred in the adsorption region (< -15,000 cm-H2O), where water retention increased by a factor of 11 and 22 for 7% PL and HW BC in sand, respectively, but by 140 and 190 % for 7% PL and HW BC in SL, respectively. The impact of BC on water retention in these sediments is explained primarily by the additional surface area and internal porosity of PL and HW BC particles. van Genuchten (VG) models were fitted to the water retention data. For SL where the impact of BC addition on water retention was

  5. Role of additives in wood plastic composite of water soluble monomer

    NASA Astrophysics Data System (ADS)

    Ali, K. M. Idriss; Khan, Mubarak A.; Husain, M. M.

    1994-10-01

    Wood plastic composites are prepared under radiation of 60Co gamma source with simul, a low grade wood of Bangladesh using a water soluble monomer acrylamide (AM) mixed with a swelling solvent methanol, water or methanol/water (1:1) at different compositions in the presence of a number of additives and co-additives such as NVP ( N-vinylpyrrolidone), TPGDA (tripropylene glycol diacrylate), TMPTA (trimethylol propane triacrylate), sulfuric acid, urea and copper sulfate. Polymer loading (PL) and tensile strength (TS) of the composites are measured. The role of these additives on the composites is also discussed. It is observed that nitrogen-atom containing-materials like urea, NVP and AM produce composites with the highest mechanical strength, and incorporation of copper into this system provides additional property of protection and preservation of the composites against attacks by insects and microbes.

  6. A first screening and risk assessment of pharmaceuticals and additives in personal care products in waste water, sludge, recipient water and sediment from Faroe Islands, Iceland and Greenland.

    PubMed

    Huber, Sandra; Remberger, Mikael; Kaj, Lennart; Schlabach, Martin; Jörundsdóttir, Hrönn Ó; Vester, Jette; Arnórsson, Mímir; Mortensen, Inge; Schwartson, Richard; Dam, Maria

    2016-08-15

    A screening of a broad range of pharmaceuticals and additives in personal care products (PPCPs) in sub-arctic locations of the Faroe Islands (FO), Iceland (IS) and Greenland (GL) was conducted. In total 36 pharmaceuticals including some metabolites, and seven additives in personal care products were investigated in influent and effluent waters as well as sludge of waste water treatment plants (WWTPs) and in water and sediment of recipients. Concentrations and distribution patterns for PPCPs discharged via sewage lines (SLs) to the marine environment were assessed. Of the 36 pharmaceuticals or metabolites analysed 33 were found close to or above the limit of detection (LOD) in all or a part of the samples. All of the seven investigated additives in personal care products were detected above the LOD. Some of the analysed PPCPs occurred in every or almost every sample. Among these were diclofenac, ibuprofen, lidocaine, naproxen, metformin, citalopram, venlafaxine, amiloride, furosemide, metoprolol, sodium dodecyl sulphate (SDS) and cetrimonium salt (ATAC-C16). Additionally, the study encompasses ecotoxicological risk assessment of 2/3 of the analysed PPCPs in recipient and diluted effluent waters. For candesartan only a small margin to levels with inacceptable risks was observed in diluted effluent waters at two locations (FO). Chronical risks for aquatic organisms staying and/or living around WWTP effluent pipe-outlets were indicated for 17β-estradiol and estriol in the three countries. Additives in PCPs were found to pose the largest risk to the aquatic environment. The surfactants CAPB and ATAC-C16 were found in concentrations resulting in risk factors up to 375 for CAPB and 165 for ATAC-C16 in recipients for diluted effluents from Iggia, Nuuk (GL) and Torshavn (FO) respectively. These results demonstrates a potentially high ecological risk stemming from discharge of surfactants as used in household and industrial detergents as well as additives in personal care

  7. Supplement to the UMTRA Project water sampling and analysis plan, Maybell, Colorado

    SciTech Connect

    1995-09-01

    This water sampling and analysis plan (WSAP) supplement supports the regulatory and technical basis for water sampling at the Maybell, Colorado, Uranium Mill Tailings Remedial Action (UMTRA) Project site, as defined in the 1994 WSAP document for Maybell (DOE, 1994a). Further, this supplement serves to confirm our present understanding of the site relative to the hydrogeology and contaminant distribution as well as our intention to continue to use the sampling strategy as presented in the 1994 WSAP document for Maybell. Ground water and surface water monitoring activities are derived from the US Environmental Protection Agency regulations in 40 CFR Part 192 (1994) and 60 CFR 2854 (1 995). Sampling procedures are guided by the UMTRA Project standard operating procedures (JEG, n.d.), the Technical Approach Document (DOE, 1989), and the most effective technical approach for the site. Additional site-specific documents relevant to the Maybell site are the Maybell Baseline Risk Assessment (currently in progress), the Maybell Remedial Action Plan (RAP) (DOE, 1994b), and the Maybell Environmental Assessment (DOE, 1995).

  8. Measurement of the tritium concentration in the fractionated distillate from environmental water samples.

    PubMed

    Atkinson, Robert; Eddy, Teresa; Kuhne, Wendy; Jannik, Tim; Brandl, Alexander

    2014-09-01

    Standard procedures for the measurement of tritium in water samples often require distillation of an appropriate sample aliquot. This distillation process may result in a fractionation of tritiated water and regular light water due to the vapor pressure isotope effect, introducing either a bias or an additional contribution to the total tritium measurement uncertainty. The current study investigates the relative change in vapor pressure isotope effect in the course of the distillation process, distinguishing it from and extending previously published measurements. The separation factor as a quantitative measure of the vapor pressure isotope effect is found to assume values of 1.04 ± 0.036, 1.05 ± 0.026, and 1.07 ± 0.038, depending on the vigor of the boiling process during distillation of the sample. A lower heat setting in the experimental setup, and therefore a less vigorous boiling process, results in a larger value for the separation factor. For a tritium measurement in water samples where the first 5 mL are discarded, the tritium concentration could be underestimated by 4-7%. PMID:24814721

  9. Effects of Water and Nitrogen Addition on Species Turnover in Temperate Grasslands in Northern China

    PubMed Central

    Xu, Zhuwen; Wan, Shiqiang; Ren, Haiyan; Han, Xingguo; Li, Mai-He; Cheng, Weixin; Jiang, Yong

    2012-01-01

    Global nitrogen (N) deposition and climate change have been identified as two of the most important causes of current plant diversity loss. However, temporal patterns of species turnover underlying diversity changes in response to changing precipitation regimes and atmospheric N deposition have received inadequate attention. We carried out a manipulation experiment in a steppe and an old-field in North China from 2005 to 2009, to test the hypothesis that water addition enhances plant species richness through increase in the rate of species gain and decrease in the rate of species loss, while N addition has opposite effects on species changes. Our results showed that water addition increased the rate of species gain in both the steppe and the old field but decreased the rates of species loss and turnover in the old field. In contrast, N addition increased the rates of species loss and turnover in the steppe but decreased the rate of species gain in the old field. The rate of species change was greater in the old field than in the steppe. Water interacted with N to affect species richness and species turnover, indicating that the impacts of N on semi-arid grasslands were largely mediated by water availability. The temporal stability of communities was negatively correlated with rates of species loss and turnover, suggesting that water addition might enhance, but N addition would reduce the compositional stability of grasslands. Experimental results support our initial hypothesis and demonstrate that water and N availabilities differed in the effects on rate of species change in the temperate grasslands, and these effects also depend on grassland types and/or land-use history. Species gain and loss together contribute to the dynamic change of species richness in semi-arid grasslands under future climate change. PMID:22768119

  10. The CERN antiproton source: Controls aspects of the additional collector ring and fast sampling devices

    NASA Astrophysics Data System (ADS)

    Chohan, V.

    1990-08-01

    The upgrade of the CERN antiproton source, meant to gain an order of magnitude in antiproton flux, required the construction of an additional ring to complement the existing antiproton accumulator (AA) and an entire rebuild of the target zone. The AA also needed major modifications to handle the increased flux and perform purely as an accumulator, preceded by collection in the collector ring (AC). The upgrade, known as the ACOL (antiproton collector) project, was approved under strict time and budgetary constraints and the existing AA control system, based on the Proton Synchrotron (PS) Divisional norms of CAMAC and Norsk-Data computers, had to be extended in the light of this. The limited (9 months) installation period for the whole upgrade meant that substantial preparatory and planning activities had to be carried out during the normal running of the AA. Advantage was taken of the upgrade to improve and consolidate the AA. Some aspects of the control system related to this upgrade are discussed together with the integration of new applications and instrumentation. The overall machine installation and running-in was carried out within the defined milestones and the project has now achieved the physics design goals.

  11. Effects of Water and Nitrogen Addition on Ecosystem Carbon Exchange in a Meadow Steppe

    PubMed Central

    Wang, Yunbo; Jiang, Qi; Yang, Zhiming; Sun, Wei; Wang, Deli

    2015-01-01

    A changing precipitation regime and increasing nitrogen deposition are likely to have profound impacts on arid and semiarid ecosystem C cycling, which is often constrained by the timing and availability of water and nitrogen. However, little is known about the effects of altered precipitation and nitrogen addition on grassland ecosystem C exchange. We conducted a 3-year field experiment to assess the responses of vegetation composition, ecosystem productivity, and ecosystem C exchange to manipulative water and nitrogen addition in a meadow steppe. Nitrogen addition significantly stimulated aboveground biomass and net ecosystem CO2 exchange (NEE), which suggests that nitrogen availability is a primary limiting factor for ecosystem C cycling in the meadow steppe. Water addition had no significant impacts on either ecosystem C exchange or plant biomass, but ecosystem C fluxes showed a strong correlation with early growing season precipitation, rather than whole growing season precipitation, across the 3 experimental years. After we incorporated water addition into the calculation of precipitation regimes, we found that monthly average ecosystem C fluxes correlated more strongly with precipitation frequency than with precipitation amount. These results highlight the importance of precipitation distribution in regulating ecosystem C cycling. Overall, ecosystem C fluxes in the studied ecosystem are highly sensitive to nitrogen deposition, but less sensitive to increased precipitation. PMID:26010888

  12. Dynamic effect of sodium-water reaction in fast flux test facility power addition sodium pipes

    SciTech Connect

    Huang, S.N.; Anderson, M.J.

    1990-03-01

    The Fast Flux Facility (FFTF) is a demonstration and test facility of the sodium-cooled fast breeder reactor. A power addition'' to the facility is being considered to convert some of the dumped, unused heat into electricity generation. Components and piping systems to be added are sodium-water steam generators, sodium loop extensions from existing dump heat exchangers to sodium-water steam generators, and conventional water/steam loops. The sodium loops can be subjected to the dynamic loadings of pressure pulses that are caused by postulated sodium leaks and subsequent sodium-water reaction in the steam generator. The existing FFTF secondary pipes and the new power addition sodium loops were evaluated for exposure to the dynamic effect of the sodium-water reaction. Elastic and simplified inelastic dynamic analyses were used in this feasibility study. The results indicate that both the maximum strain and strain range are within the allowable limits. Several cycles of the sodium-water reaction can be sustained by the sodium pipes that are supported by ordinary pipe supports and seismic restraints. Expensive axial pipe restraints to withstand the sodium-water reaction loads are not needed, because the pressure-pulse-induced alternating bending stresses act as secondary stresses and the pressure pulse dynamic effect is a deformation-controlled quantity and is self-limiting. 14 refs., 7 figs., 3 tabs.

  13. Apparatus for direct addition of reagents into a nuclear magnetic resonance (NMR) sample in the NMR probe

    NASA Astrophysics Data System (ADS)

    Perrin, Charles L.; Rivero, Ignacio A.

    1999-04-01

    Nuclear magnetic resonance (NMR) is a widely used tool in chemistry and biochemistry. It is occasionally necessary to add small aliquots of solvents or reagents repeatedly into the NMR tube. Ordinarily this is accomplished only by ejecting the sample and carrying out the addition outside the probe. It would be preferable to add the aliquot directly into the sample. We have designed and implemented a delivery system to accomplish this. This apparatus is particularly applicable to a recent NMR titration method for measuring relative pK's and to experiments where temperature must also be varied. This apparatus provides a safe, simple, and inexpensive method for repeated aliquot addition directly into the sample in the NMR probe.

  14. Phosphorus Concentrations in Stream-Water and Reference Samples - An Assessment of Laboratory Comparability

    USGS Publications Warehouse

    McHale, Michael R.; McChesney, Dennis

    2007-01-01

    In 2003, a study was conducted to evaluate the accuracy and precision of 10 laboratories that analyze water-quality samples for phosphorus concentrations in the Catskill Mountain region of New York State. Many environmental studies in this region rely on data from these different laboratories for water-quality analyses, and the data may be used in watershed modeling and management decisions. Therefore, it is important to determine whether the data reported by these laboratories are of comparable accuracy and precision. Each laboratory was sent 12 samples for triplicate analysis for total phosphorus, total dissolved phosphorus, and soluble reactive phosphorus. Eight of these laboratories reported results that met comparability criteria for all samples; the remaining two laboratories met comparability criteria for only about half of the analyses. Neither the analytical method used nor the sample concentration ranges appeared to affect the comparability of results. The laboratories whose results were comparable gave consistently comparable results throughout the concentration range analyzed, and the differences among methods did not diminish comparability. All laboratories had high data precision as indicated by sample triplicate results. In addition, the laboratories consistently reported total phosphorus values greater than total dissolved phosphorus values, and total dissolved phosphorus values greater than soluble reactive phosphorus values, as would be expected. The results of this study emphasize the importance of regular laboratory participation in sample-exchange programs.

  15. GROUND WATER SAMPLING FOR VERTICAL PROFILING OF CONTAMINANTS

    EPA Science Inventory

    Accurate delineation of plume boundaries and vertical contaminant distribution are necessary in order to adequately characterize waste sites and determine remedial strategies to be employed. However, it is important to consider the sampling objectives, sampling methods, and sampl...

  16. Effect of dilute polymer additives on the acoustic cavitation threshold of water

    SciTech Connect

    Crum, L.A.; Brosey, J.E.

    1984-02-01

    Measurements are presented of the variation of the acoustic cavitation threshold of water with concentration of the polymer additives polyethylene oxide and guar gum. It was found that small amounts of these additives could significantly increase the cavitation threshold. A theoretical model, based upon nucleation of a gas bubble from a Harvey-type crevice in a mote or solid particle, is developed that gives good agreement with the measurements. The applicability of this approach to an explanation of cavitation index reduction in flow-generated or confined jet cavitation, when polymer additives are introduced, is discussed.

  17. Releasing-addition method for the flame-photometric determination of calcium in thermal waters

    USGS Publications Warehouse

    Rowe, J.J.

    1963-01-01

    Study of the interferences of silica and sulfate in the flame-photometric determination of calcium in thermal waters has led to the development of a method requiring no prior chemical separations. The interference effects of silica, sulfate, potassium, sodium, aluminum, and phosphate are overcome by an addition technique coupled with the use of magnesium as a releasing agent. ?? 1963.

  18. Water sorption of CH3- and CF3-Bis-GMA based resins with additives

    PubMed Central

    PRAKKI, Anuradha; CILLI, Renato; VIEIRA, Ian Matos; DUDUMAS, Kristina; PEREIRA, José Carlos

    2012-01-01

    Objectives To evaluate the effect of additives on the water sorption characteristics of Bis-GMA based copolymers and composites containing TEGDMA, CH3Bis-GMA or CF3Bis-GMA. Material and methods Fifteen experimental copolymers and corresponding composites were prepared combining Bis-GMA and TEGDMA, CH3Bis-GMA or CF3Bis-GMA, with aldehyde or diketone (24 and 32 mol%) totaling 30 groups. For composites, barium aluminosilicate glass and pyrogenic silica was added to comonomer mixtures. Photopolymerization was effected by 0.2 wt% each of camphorquinone and N,N-dimethyl-p-toluidine. Specimen densities in dry and water saturated conditions were obtained by Archimedes' method. Water sorption and desorption were evaluated in a desorption-sorption-desorption cycle. Water uptake (%WU), water desorption (%WD), equilibrium solubility (ES; µg/mm3), swelling (f) and volume increase (%V) were calculated using appropriate equations. Results All resins with additives had increased %WU and ES. TEGDMA-containing systems presented higher %WU, %WD, ES, f and %V values, followed by resins based on CH3Bis-GMA and CF3Bis-GMA. Conclusions Aldehyde and diketone led to increases in the water sorption characteristics of experimental resins. PMID:23032211

  19. Burning of suspended coal-water slurry droplet with oil as combustion additive. Final report

    SciTech Connect

    Yao, S.C.

    1984-10-01

    The combustion of single coal-water slurry droplet with oil as combustion additive (CWOM) has been studied. In this study, the droplet is suspended on a fine quartz fiber and is exposed to the hot combustion product of propane (C/sub 3/H/sub 8/) and air. The results are documented in a movie series. The combustion of CWOM with various combinations of concentrations are compared with that of coal-water slurry and water-oil mixture droplets. The combustion of coal-water slurry is enhanced significantly due to the presence of emulsified kerosene. The enhancement is also dependent upon the mixing procedure during preparation of CWOM. The presence of emulsified kerosene induces local boil-off and combustion that coal particles are splashed as fire works during the early evaporation stage of droplet heat-up. After particle splashing, blow-holes appear on the droplet surface. The popcorn and swelling phenomena usually occurred in coal-water-slurry combustion is greatly reduced. Significant combustion enhancement occurs with the use of kerosene in an amount of about 15 percent of the overall CWOM. This process of using kerosene as combustion additive may provide obvious advantage for the combustion of bituminous coal-water slurry. 4 references, 6 figures.

  20. Electromembrane extraction for the determination of parabens in water samples.

    PubMed

    Villar-Navarro, Mercedes; Moreno-Carballo, María Del Carmen; Fernández-Torres, Rut; Callejón-Mochón, Manuel; Bello-López, Miguel Ángel

    2016-02-01

    To our knowledge, for the first time an electromembrane extraction combined with a high-performance liquid chromatography procedure using diode-array detection has been developed for the determination of five of the most widely used parabens: ethyl 4-hydroxybenzoate, propyl 4-hydroxybenzoate, butyl 4-hydroxybenzoate, isobutyl 4-hydroxybenzoate, and benzyl 4-hydroxybenzoate. Parabens were extracted from pH 4 aqueous sample solutions with use of an Accurel® S6/2 polypropylene hollow fiber that supports a liquid membrane of 1-octanol to a pH 12 aqueous acceptor solution placed inside the lumen of the hollow fiber. An electric current of 30 V was applied over the supported liquid membrane by means of platinum wires placed in the donor and acceptor phases. Parabens were extracted in 40 min with enrichment factors in the 30-49 range. The procedure has detection limits between 0.98 and 1.43 μg L(-1). The method was applied to the determination of parabens in surface environmental waters with excellent results. PMID:26753971

  1. Chromobacterium aquaticum sp. nov., isolated from spring water samples.

    PubMed

    Young, Chiu-Chung; Arun, A B; Lai, Wei-An; Chen, Wen-Ming; Chou, Jui-Hsing; Chao, Jiu-Hsing; Shen, Fo-Ting; Rekha, P D; Kämpfer, Peter

    2008-04-01

    Strain CC-SEYA-1T, a motile, Gram-negative, non-violet-pigmented bacterium, was isolated on nutrient agar from spring-water samples collected from Yang-Ming Mountain, Taipei County, Taiwan. 16S rRNA gene sequence studies showed that the strain clustered with Chromobacterium violaceum (96.8 % similarity) and Chromobacterium subtsugae (96.5 % similarity), followed by Aquitalea magnusonii (95.8 % similarity). The fatty acid profile was slightly different from those reported for C. violaceum, C. subtsugae and A. magnusonii. The results of DNA-DNA hybridization, and physiological and biochemical tests allowed both genotypic and phenotypic differentiation of the isolate from the described Chromobacterium species. It is evident from the data obtained that the strain should be classified as a novel species in the genus Chromobacterium. The name proposed for this taxon is Chromobacterium aquaticum sp. nov.; the type strain is CC-SEYA-1T (=CCUG 55175T=BCRC 17769T). PMID:18398186

  2. Free energy calculation of water addition coupled to reduction of aqueous RuO4-

    NASA Astrophysics Data System (ADS)

    Tateyama, Yoshitaka; Blumberger, Jochen; Ohno, Takahisa; Sprik, Michiel

    2007-05-01

    Free energy calculations were carried out for water addition coupled reduction of aqueous ruthenate, RuO4-+H2O +e-→[RuO3(OH)2]2-, using Car-Parrinello molecular dynamics simulations. The full reaction is divided into the reduction of the tetrahedral monoanion, RuO4-+e-→RuO42-, followed by water addition, RuO42-+H2O →[RuO3(OH)2]2-. The free energy of reduction is computed from the fluctuations of the vertical energy gap using the MnO4-+e -→MnO42- reaction as reference. The free energy for water addition is estimated using constrained molecular dynamics methods. While the description of this complex reaction, in principle, involves multiple reaction coordinates, we found that reversible transformation of the reactant into the product can be achieved by control of a single reaction coordinate consisting of a suitable linear combination of atomic distances. The free energy difference of the full reaction is computed to be -0.62eV relative to the normal hydrogen electrode. This is in good agreement with the experimental value of -0.59eV, lending further support to the hypothesis that, contrary to the ruthenate monoanion, the dianion is not tetrahedral but forms a trigonal-bipyramidal dihydroxo complex in aqueous solution. We construct an approximate two-dimensional free energy surface using the coupling parameter for reduction and the mechanical constraint for water addition as variables. Analyzing this surface we find that in the most favorable reaction pathway the reduction reaction precedes water addition. The latter takes place via the protonated complex [RuO3(OH)]- and subsequent transport of the created hydroxide ion to the fifth coordination site of Ru.

  3. Evaluation of methods used from 1965 through 1982 to determine inorganic constituents in water samples

    USGS Publications Warehouse

    Friedman, Linda C.; Fishman, Marvin J.

    1989-01-01

    Since 1962, the U.S. Geological Survey has prepared and distributed Standard Reference Water Samples (SRWS) to participating laboratories in order to alert them to possible analytical deficiencies. This report marks the first time that a concentrated effort has been made to examine and compare the SRWS data for each constituent by the analytical method that was used to obtain the data. Unlike laboratories that participate in interlaboratory studies that are designed to determine the precision and accuracy of a particular analytical method, laboratories that participate in the SRWS program are allowed to select the method used to analyze a reference sample and are requested to report the method used. Data for a particular method could not be compared with a 'true' value because the data were obtained from analyses of reference samples that were prepared using natural waters; however, where possible a comparison was made between the mean concentrations obtained by the various analytical methods that were used to determine each constituent. Where enough information is available, models for predicting the precisions of the methods have been developed, and the precisions have been compared. In addition to the data presented in the reports, this evaluation provides a good indication of methods that were used routinely to analyze water samples during the 18 years of study.

  4. Volatile organic compound matrix spike recoveries for ground- and surface-water samples, 1997-2001

    USGS Publications Warehouse

    Rowe, Barbara L.; Delzer, Gregory C.; Bender, David A.; Zogorski, John S.

    2005-01-01

    The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program used field matrix spikes (FMSs), field matrix spike replicates (FMSRs), laboratory matrix spikes (LMSs), and laboratory reagent spikes (LRSs), in part, to assess the quality of volatile organic compound (VOC) data from water samples collected and analyzed in more than 50 of the Nation's largest river basins and aquifers (Study Units). The data-quality objectives of the NAWQA Program include estimating the extent to which variability, degradation, and matrix effects, if any, may affect the interpretation of chemical analyses of ground- and surface-water samples. In order to help meet these objectives, a known mass of VOCs was added (spiked) to water samples collected in 25 Study Units. Data within this report include recoveries from 276 ground- and surface-water samples spiked with a 25-microliter syringe with a spike solution containing 85 VOCs to achieve a concentration of 0.5 microgram per liter. Combined recoveries for 85 VOCs from spiked ground- and surface-water samples and reagent water were used to broadly characterize the overall recovery of VOCs. Median recoveries for 149 FMSs, 107 FMSRs, 20 LMSs, and 152 LRSs were 79.9, 83.3, 113.1, and 103.5 percent, respectively. Spike recoveries for 85 VOCs also were calculated individually. With the exception of a few VOCs, the median percent recoveries determined from each spike type for individual VOCs followed the same pattern as for all VOC recoveries combined, that is, listed from least to greatest recovery-FMSs, FMSRs, LRSs, and LMSs. The median recoveries for individual VOCs ranged from 63.7 percent to 101.5 percent in FMSs; 63.1 percent to 101.4 percent in FMSRs; 101.7 percent to 135.0 percent in LMSs; and 91.0 percent to 118.7 percent in LRSs. Additionally, individual VOC recoveries were compared among paired spike types, and these recoveries were used to evaluate potential bias in the method. Variability associated with field

  5. 40 CFR 257.23 - Ground-water sampling and analysis requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Ground-water sampling and analysis...-Hazardous Waste Disposal Units Ground-Water Monitoring and Corrective Action § 257.23 Ground-water sampling and analysis requirements. (a) The ground-water monitoring program must include consistent...

  6. 40 CFR 258.53 - Ground-water sampling and analysis requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Ground-water sampling and analysis... WASTES CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Ground-Water Monitoring and Corrective Action § 258.53 Ground-water sampling and analysis requirements. (a) The ground-water monitoring program...

  7. 40 CFR 258.53 - Ground-water sampling and analysis requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Ground-water sampling and analysis... WASTES CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Ground-Water Monitoring and Corrective Action § 258.53 Ground-water sampling and analysis requirements. (a) The ground-water monitoring program...

  8. 40 CFR 258.53 - Ground-water sampling and analysis requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Ground-water sampling and analysis... WASTES CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS Ground-Water Monitoring and Corrective Action § 258.53 Ground-water sampling and analysis requirements. (a) The ground-water monitoring program...

  9. 40 CFR 257.23 - Ground-water sampling and analysis requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Ground-water sampling and analysis...-Hazardous Waste Disposal Units Ground-Water Monitoring and Corrective Action § 257.23 Ground-water sampling and analysis requirements. (a) The ground-water monitoring program must include consistent...

  10. 40 CFR 257.23 - Ground-water sampling and analysis requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Ground-water sampling and analysis...-Hazardous Waste Disposal Units Ground-Water Monitoring and Corrective Action § 257.23 Ground-water sampling and analysis requirements. (a) The ground-water monitoring program must include consistent...

  11. Recovery of several volatile organic compounds from simulated water samples: Effect of transport and storage

    USGS Publications Warehouse

    Friedman, L.C.; Schroder, L.J.; Brooks, M.G.

    1986-01-01

    Solutions containing volatile organic compounds were prepared in organic-free water and 2% methanol and submitted to two U.S. Geological Survey laboratories. Data from the determination of volatile compounds in these samples were compared to analytical data for the same volatile compounds that had been kept in solutions 100 times more concentrated until immediately before analysis; there was no statistically significant difference in the analytical recoveries. Addition of 2% methanol to the storage containers hindered the recovery of bromomethane and vinyl chloride. Methanol addition did not enhance sample stability. Further, there was no statistically significant difference in results from the two laboratories, and the recovery efficiency was more than 80% in more than half of the determinations made. In a subsequent study, six of eight volatile compounds showed no significant loss of recovery after 34 days.

  12. The Use of Additional GPS Frequencies to Independently Determine Tropospheric Water Vapor Profiles

    NASA Technical Reports Server (NTRS)

    Herman, B.M.; Feng, D.; Flittner, D. E.; Kursinski, E. R.

    2000-01-01

    It is well known that the currently employed L1 and L2 GPS/MET frequencies (1.2 - 1.6) Ghz) do not allow for the separation of water vapor and density (or temperature) from active microwave occultation measurements in regions of the troposphere warmer than 240 K Therefore, additional information must be used, from other types of measurements and weather analyses, to recover water vapor (and temperature) profiles. Thus in data sparse regions, these inferred profiles can be subject to larger errors than would result in data rich regions. The use of properly selected additional GPS frequencies enables a direct, independent measurement of the absorption associated with the water vapor profile, which may then be used in the standard GPS/MET retrievals to obtain a more accurate determination of atmospheric temperature throughout the water vapor layer. This study looks at the use of microwave crosslinks in the region of the 22 Ghz water vapor absorption line for this purpose. An added advantage of using 22 Ghz frequencies is that they are only negligibly affected by the ionosphere in contrast to the large effect at the GPS frequencies. The retrieval algorithm uses both amplitude and phase measurements to obtain profiles of atmospheric pressure, temperature and water water vapor pressure with a vertical resolution of 1 km or better. This technique also provides the cloud liquid water content along the ray path, which is in itself an important element in climate monitoring. Advantages of this method include the ability to make measurements in the presence of clouds and the use of techniques and technology proven through the GPS/MET experiment and several of NASA's planetary exploration missions. Simulations demonstrating this method will be presented for both clear and cloudy sky conditions.

  13. Gasbuggy, New Mexico, Natural Gas and Produced Water Sampling and Analysis Results for 2011

    SciTech Connect

    2011-09-01

    The U.S. Department of Energy (DOE) Office of Legacy Management conducted natural gas sampling for the Gasbuggy, New Mexico, site on June 7 and 8, 2011. Natural gas sampling consists of collecting both gas samples and samples of produced water from gas production wells. Water samples from gas production wells were analyzed for gamma-emitting radionuclides, gross alpha, gross beta, and tritium. Natural gas samples were analyzed for tritium and carbon-14. ALS Laboratory Group in Fort Collins, Colorado, analyzed water samples. Isotech Laboratories in Champaign, Illinois, analyzed natural gas samples.

  14. Sampling and Analysis for Lead in Water and Soil Samples on a University Campus: A Student Research Project.

    ERIC Educational Resources Information Center

    Butala, Steven J.; Zarrabi, Kaveh

    1995-01-01

    Describes a student research project that determined concentrations of lead in water drawn from selected drinking fountains and in selected soil samples on the campus of the University of Nevada, Las Vegas. (18 references) (DDR)

  15. SAMPLING OIL-WATER MIXTURES AT OHMSETT (OIL AND HAZARDOUS MATERIALS SIMULATED ENVIRONMENTAL TEST TANK)

    EPA Science Inventory

    The report describes procedures developed at the Oil and Hazardous Material Simulated Environmental Test Tank (OHMSETT) for sampling oil and water mixtures. Two procedures for sampling in containers are discussed: grab and stratified sampling. Both of these techniques require str...

  16. TRITIUM UNCERTAINTY ANALYSIS FOR SURFACE WATER SAMPLES AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Atkinson, R.

    2012-07-31

    Radiochemical analyses of surface water samples, in the framework of Environmental Monitoring, have associated uncertainties for the radioisotopic results reported. These uncertainty analyses pertain to the tritium results from surface water samples collected at five locations on the Savannah River near the U.S. Department of Energy's Savannah River Site (SRS). Uncertainties can result from the field-sampling routine, can be incurred during transport due to the physical properties of the sample, from equipment limitations, and from the measurement instrumentation used. The uncertainty reported by the SRS in their Annual Site Environmental Report currently considers only the counting uncertainty in the measurements, which is the standard reporting protocol for radioanalytical chemistry results. The focus of this work is to provide an overview of all uncertainty components associated with SRS tritium measurements, estimate the total uncertainty according to ISO 17025, and to propose additional experiments to verify some of the estimated uncertainties. The main uncertainty components discovered and investigated in this paper are tritium absorption or desorption in the sample container, HTO/H{sub 2}O isotopic effect during distillation, pipette volume, and tritium standard uncertainty. The goal is to quantify these uncertainties and to establish a combined uncertainty in order to increase the scientific depth of the SRS Annual Site Environmental Report.

  17. Sample data processing in an additive and reproducible taxonomic workflow by using character data persistently linked to preserved individual specimens

    PubMed Central

    Kilian, Norbert; Henning, Tilo; Plitzner, Patrick; Müller, Andreas; Güntsch, Anton; Stöver, Ben C.; Müller, Kai F.; Berendsohn, Walter G.; Borsch, Thomas

    2015-01-01

    We present the model and implementation of a workflow that blazes a trail in systematic biology for the re-usability of character data (data on any kind of characters of pheno- and genotypes of organisms) and their additivity from specimen to taxon level. We take into account that any taxon characterization is based on a limited set of sampled individuals and characters, and that consequently any new individual and any new character may affect the recognition of biological entities and/or the subsequent delimitation and characterization of a taxon. Taxon concepts thus frequently change during the knowledge generation process in systematic biology. Structured character data are therefore not only needed for the knowledge generation process but also for easily adapting characterizations of taxa. We aim to facilitate the construction and reproducibility of taxon characterizations from structured character data of changing sample sets by establishing a stable and unambiguous association between each sampled individual and the data processed from it. Our workflow implementation uses the European Distributed Institute of Taxonomy Platform, a comprehensive taxonomic data management and publication environment to: (i) establish a reproducible connection between sampled individuals and all samples derived from them; (ii) stably link sample-based character data with the metadata of the respective samples; (iii) record and store structured specimen-based character data in formats allowing data exchange; (iv) reversibly assign sample metadata and character datasets to taxa in an editable classification and display them and (v) organize data exchange via standard exchange formats and enable the link between the character datasets and samples in research collections, ensuring high visibility and instant re-usability of the data. The workflow implemented will contribute to organizing the interface between phylogenetic analysis and revisionary taxonomic or monographic work

  18. The origin of water in the primitive Moon as revealed by the lunar highlands samples

    NASA Astrophysics Data System (ADS)

    Barnes, Jessica J.; Tartèse, Romain; Anand, Mahesh; McCubbin, Francis M.; Franchi, Ian A.; Starkey, Natalie A.; Russell, Sara S.

    2014-03-01

    The recent discoveries of hydrogen (H) bearing species on the lunar surface and in samples derived from the lunar interior have necessitated a paradigm shift in our understanding of the water inventory of the Moon, which was previously considered to be a ‘bone-dry’ planetary body. Most sample-based studies have focused on assessing the water contents of the younger mare basalts and pyroclastic glasses, which are partial-melting products of the lunar mantle. In contrast, little attention has been paid to the inventory and source(s) of water in the lunar highlands rocks which are some of the oldest and most pristine materials available for laboratory investigations, and that have the potential to reveal the original history of water in the Earth-Moon system. Here, we report in-situ measurements of hydroxyl (OH) content and H isotopic composition of the mineral apatite from four lunar highlands samples (two norites, a troctolite, and a granite clast) collected during the Apollo missions. Apart from troctolite in which the measured OH contents in apatite are close to our analytical detection limit and its H isotopic composition appears to be severely compromised by secondary processes, we have measured up to ˜2200 ppm OH in the granite clast with a weighted average δD of ˜ -105±130‰, and up to ˜3400 ppm OH in the two norites (77215 and 78235) with weighted average δD values of -281±49‰ and -27±98‰, respectively. The apatites in the granite clast and the norites are characterised by higher OH contents than have been reported so far for highlands samples, and have H isotopic compositions similar to those of terrestrial materials and some carbonaceous chondrites, providing one of the strongest pieces of evidence yet for a common origin for water in the Earth-Moon system. In addition, the presence of water, of terrestrial affinity, in some samples of the earliest-formed lunar crust suggests that either primordial terrestrial water survived the aftermath

  19. Lithium Bromide/Water as Additives in Dearomatizing Samarium-Ketyl (Hetero)Arene Cyclizations.

    PubMed

    Rao, Chintada Nageswara; Bentz, Christoph; Reissig, Hans-Ulrich

    2015-11-01

    New conditions for dearomatizing samarium-ketyl (hetero)arene cyclizations are reported. In many examples of these samarium diiodide-mediated reactions, lithium bromide and water can be used as additives instead of the carcinogenic and mutagenic hexamethylphosphoramide (HMPA). The best results were obtained for the cyclizations of N-acylated indole derivatives delivering the expected indolines in good yields and excellent diastereoselectivities. A new type of cyclization delivering indolyl-substituted allene derivatives is also described. The scope and limitations of the lithium bromide/water system are discussed. PMID:26368916

  20. Occurrence and genotype of Giardia cysts isolated from faecal samples of children and dogs and from drinking water samples in an aboriginal area of central Taiwan.

    PubMed

    Liang, Chao-hua; Tsaihong, John Chin; Cheng, Ya-yin; Peng, Shih-yi

    2012-06-01

    To investigate some aspects of Giardia infection, we performed a cross-sectional study on schoolchildren from an aboriginal area of Nantou County in central Taiwan. Faecal samples from 209 participants and samples of dog faeces and of water from mountain springs found in the area were collected. The participants also filled a questionnaire pertaining to demographic data. Giardia duodenalis was detected in eight of the 209 participants, and all positive isolates belonged to assemblage A. In addition, assemblage A isolates were obtained from four of the 22 water samples, and assemblage C or D isolates were obtained from four of the 42 canine faecal samples. Our results suggest that the risk of Giardia transmission is greater from waterborne than canine transmission in this study area. PMID:22542987

  1. Assessing Model Structural Uncertainty Using a Split Sample Approach for a Distributed Water Quality Model

    NASA Astrophysics Data System (ADS)

    Meixner, T.; van Griensven, A.

    2003-12-01

    A method for assessing model structural uncertainty as opposed to the more commonly investigated parameter uncertainty is presented that should aid in the development of improved water quality models. Elsewhere (see van Griensven and Meixner abstract, this session) we have developed a methodology (ParaSol) to estimate model parameter uncertainty. Uncertainty is typically estimated with a specific time period of data. However from experience with model calibration problems we know that we need to employ split sample and other evaluation tests to estimate the confidence we should have in our models and our methods. Evaluation tests generally give us qualitative data about confidence in our models. Here we propose a method that uses the split sample approach to generate a quantitative estimate of model structural uncertainty. The Sources of Uncertainty Global Assessment using Split SamplES (SUNGLASSES) method is designed to assess predictive uncertainty that is not captured by parameter or physical input uncertainty. We assume that this additional uncertainty represents model structural error in how the model represents the physical, chemical, and biological processes incorporated into water quality models. This method operates by selecting a threshold for a sample statistic (bias in our case), when the sample statistic for a model simulation is below the threshold the simulation is acceptable. Where this methodology differs from others is that the threshold is determined by evaluating whether the chosen threshold will capture simulations during an evaluation time period (hence split sample) that was not used to initially calibrate the model and generate parameter estimates. Most existing methods rely solely on sample statistics during a calibration period. The new method thus captures an element of predictive error that originates in the structural conception of the processes controlling water quality. The described method is applied on a Soil Water Assessment Tool

  2. The effect of sampling strategies on assessment of water quality criteria attainment.

    PubMed

    Wang, Yuxin; Wilson, Jessica M; VanBriesen, Jeanne M

    2015-05-01

    Sample locations for large river studies affect the representativeness of data, and thus can alter decisions made regarding river conditions and the need for interventions to improve water quality. The present study evaluated three water-quality sampling programs for Total Dissolved Solid (TDS) assessment in the Monongahela River from 2008 to 2012. The sampling plans cover the same 145 km of river but differ in frequency, sample location and type (e.g., river water sample vs drinking water plant intake sample). Differences resulting from temporal and spatial variability in sampling lead to different conclusions regarding water quality in the river (including regulatory listing decisions), especially when low flow leads to concentrations at or near the water quality criteria (500mg/L TDS). Drinking water samples exceeded the criteria 82 out of 650 samples (12.6%), while river water samples exceeded the criteria 47 out of 464 samples (10.1%). Different water sample types could provide different pictures of water quality in the river and lead to different regulatory listing decisions. PMID:25704747

  3. Acidification of East Siberian Arctic Shelf waters through addition of freshwater and terrestrial carbon

    NASA Astrophysics Data System (ADS)

    Semiletov, Igor; Pipko, Irina; Gustafsson, Örjan; Anderson, Leif G.; Sergienko, Valentin; Pugach, Svetlana; Dudarev, Oleg; Charkin, Alexander; Gukov, Alexander; Bröder, Lisa; Andersson, August; Spivak, Eduard; Shakhova, Natalia

    2016-05-01

    Ocean acidification affects marine ecosystems and carbon cycling, and is considered a direct effect of anthropogenic carbon dioxide uptake from the atmosphere. Accumulation of atmospheric CO2 in ocean surface waters is predicted to make the ocean twice as acidic by the end of this century. The Arctic Ocean is particularly sensitive to ocean acidification because more CO2 can dissolve in cold water. Here we present observations of the chemical and physical characteristics of East Siberian Arctic Shelf waters from 1999, 2000-2005, 2008 and 2011, and find extreme aragonite undersaturation that reflects acidity levels in excess of those projected in this region for 2100. Dissolved inorganic carbon isotopic data and Markov chain Monte Carlo simulations of water sources using salinity and δ18O data suggest that the persistent acidification is driven by the degradation of terrestrial organic matter and discharge of Arctic river water with elevated CO2 concentrations, rather than by uptake of atmospheric CO2. We suggest that East Siberian Arctic Shelf waters may become more acidic if thawing permafrost leads to enhanced terrestrial organic carbon inputs and if freshwater additions continue to increase, which may affect their efficiency as a source of CO2.

  4. Effect of Isopropyl Alcohol Addition in Ozonated Water on the Corrosion of Tungsten Film

    NASA Astrophysics Data System (ADS)

    Lee, Younghwan; Lee, June Young; Im, Kyung Taek; Lim, Sangwoo

    2009-05-01

    Acetic acid (HAc) or 2-propanol (IPA) was added to ozonated water vapor, and its ability to clean corroded Al and W surfaces was studied. No changes to the surface morphology or film thickness were observed on any of the Al films to which the ozonated water vapor cleaning process was applied, either with or without the addition of HAc and IPA. No change in the W surface was observed when it was exposed to either pure ozonated water vapor or that which had HAc-added. However, the surface morphology of the W film changed, and its thickness decreased, when it was exposed to the ozonated water vapor with added IPA. It was also noted that no corrosion occurred on the surface of W when only IPA and the water mixture vapor were injected. Given that the pH of the water with added IPA was unchanged, regardless of whether ozone feeding had occurred, it can be concluded that the main reason for the corrosion of the W film is the accelerated oxidation of W. This accelerated oxidation is a byproduct of ozone decomposition in the presence of a radical promoter, rather than the enhanced dissolution of oxidized W.

  5. Effect of AN Additive on Thermal Output during Electrolysis of Heavy Water with a Palladium Cathode

    NASA Astrophysics Data System (ADS)

    Wang, Q.; Dash, J.

    A titanium additive to a heavy water-sulfuric acid electrolyte has been found to increase the thermal output during electrolysis with a palladium foil cathode. Eight runs, about 6 h each, over a period of 16 days, gave an average of 1.8 W excess thermal power output compared with a light water control cell. This is about twice the excess obtained in co-deposition experiments. The excess thermal power output ranged from 0.5 ± 0.1 to 2.6 ± 0.1 W, which was an average of about 17% more than the input power. The additive apparently catalyzes heat-producing reactions on the surface of the palladium. After electrolysis, the Pd cathode contained localized surface concentrations of Ag, Ni, Fe, Ti, S, and Pt.

  6. Standard addition method for the determination of pharmaceutical residues in drinking water by SPE-LC-MS/MS.

    PubMed

    Cimetiere, Nicolas; Soutrel, Isabelle; Lemasle, Marguerite; Laplanche, Alain; Crocq, André

    2013-01-01

    The study of the occurrence and fate of pharmaceutical compounds in drinking or waste water processes has become very popular in recent years. Liquid chromatography with tandem mass spectrometry is a powerful analytical tool often used to determine pharmaceutical residues at trace level in water. However, many steps may disrupt the analytical procedure and bias the results. A list of 27 environmentally relevant molecules, including various therapeutic classes and (cardiovascular, veterinary and human antibiotics, neuroleptics, non-steroidal anti-inflammatory drugs, hormones and other miscellaneous pharmaceutical compounds), was selected. In this work, a method was developed using ultra performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) and solid-phase extraction to determine the concentration of the 27 targeted pharmaceutical compounds at the nanogram per litre level. The matrix effect was evaluated from water sampled at different treatment stages. Conventional methods with external calibration and internal standard correction were compared with the standard addition method (SAM). An accurate determination of pharmaceutical compounds in drinking water was obtained by the SAM associated with UPLC-MS/MS. The developed method was used to evaluate the occurrence and fate of pharmaceutical compounds in some drinking water treatment plants in the west of France. PMID:24617062

  7. Additional capabilities and benchmarking with the SPERT transients for heavy water application of the PARET code

    SciTech Connect

    Woodruff, W.L.

    1989-01-01

    The capabilities of the PARET code have been expanded to include the ability to compute steady-state and transient results for heavy water reactors. A comparison is provided between PARET and the SPERT II series of transients. Another significant improvement in the code is the addition of a restart capability. The current capabilities of the code are summarized. 7 refs., 12 figs., 3 tabs.

  8. [Clinical evaluation of an oxygen concentrator and humidifier that does not require additional reservoir water].

    PubMed

    Burioka, Naoto; Nakamoto, Sachiko; Fukuoka, Yasushi; Shimizu, Eiji

    2011-02-01

    A conventional humidifier with a reservoir of water for humidification can produce micro-aerosols contaminated with bacteria. The present study was undertaken to determine the clinical efficiency of a membrane humidifier that does not require additional reservoir water. We analyzed relative room air humidity and oxygen levels obtained from 2 pressure-swing adsorption (PSA)-type oxygen concentrators with membrane humidifiers. A significant correlation was found between relative room air humidity and that of oxygen moistened by a membrane humidifier. Several patients with chronic respiratory failure experienced improvements in subjectively reported nasal dryness using an oxygen concentrator with a membrane humidifier. This device avoids the need to change reservoir water, and may improve patient quality of life in the home. PMID:21400902

  9. Innovative additives can increase the drilling rates of water-based muds

    SciTech Connect

    Growcock, F.B.; Sinor, L.A.; Reece, A.R.; Powers, J.R.

    1994-12-31

    Several types of organic compounds were tested as rate of penetration (ROP) enhancers for a simple gel/water mud. Experiments conducted in a full-size drilling apparatus with both rollercone and PDC bits at wellbore pressures of 1,100 and 2,000 psi indicate that a paraffin/ester mixture, several terpenes and a mixture of insoluble poly(propylene glycols), or PPGs, can all increase the ROP by 5 to 20% when added at levels of 2--4% by volume. Complementary lubricity and shale recovery studies suggest that the paraffin and terpenes function by making the steel surfaces less water-wetting, thereby reducing the tendency of partially hydrated sticky shales to adhere. The PPG mixture, on the other hand, may function primarily by interacting directly with the shales to reduce their tendency to form a sticky mass. In either case, the additives increased ROP to levels comparable to the ROP observed with pure water.

  10. Effect of addition of water-soluble chitin on amylose film.

    PubMed

    Suzuki, Shiho; Shimahashi, Katsumasa; Takahara, Junichi; Sunako, Michihiro; Takaha, Takeshi; Ogawa, Kozo; Kitamura, Shinichi

    2005-01-01

    Amylose films blended with chitosan, which were free from additives such as acid, salt, and plasticizer, were prepared by casting mixtures of an aqueous solution of an enzymatically synthesized amylose and that of water-soluble chitin (44.1% deacetylated). The presence of a small amount of chitin (less than 10%) increased significantly the permeability of gases (N2, O2, CO2, C2H4) and improved the mechanical parameters of amylose film; particularly, the elastic modulus and elongation of the blend films were larger than those of amylose or chitin films. No antibacterial activity was observed with either amylose or water-soluble chitin films. But amylose films having a small amount of chitin showed strong antibacterial action, suggesting a morphological change in water-soluble chitin on the film surface by blending with amylose molecule. These facts suggested the presence of a molecular complex of amylose and chitosan. PMID:16283751

  11. Stacking and simultaneous determination of estrogens in water samples by CE with electrochemical detection.

    PubMed

    Li, Ping; Zhao, Wenjie; Wang, Xiaoning; Shi, Guoyue; Zhou, Tianshu

    2013-01-01

    A rapid and sensitive method based on transient ITP and field enhancement in CE with electrochemical detection at copper disk electrode was developed for the simultaneous separation and determination of three estrogens: estrone, 17β-estradiol, and estriol. The effects of several important factors that influence the separation and detection were investigated. Under the optimum conditions, the estrogens could be separated in 0.06 mol/L sodium hydroxide solution within 14 min. With transient ITP by addition of 0.5% NaCl, a good linear response was obtained for three estrogens from 0.2 to 10 μmol/L, with correlation coefficients higher than 0.9993. The detection limits were 8.9 × 10(-8) , 6.7 × 10(-8) , and 1.1 × 10(-7) mol/L (S/N = 3) for estriol, 17β-estradiol, and estrone, respectively. This method was successfully employed to analyze different water samples from waterworks, tap water, fishpond, and river samples with recoveries in the range of 90.8-108.9%, and RSDs < 4.69%. The satisfied results demonstrated that this method was of convenient preparation, high sensitivity, and good repeatability, which could be applied to the rapid determination of environmental water samples. PMID:23255353

  12. Determination of uranium, iron, copper, and nickel in rock and water samples by MEKC.

    PubMed

    Mirza, Muhammad Aslam; Khuhawar, Muhammad Yar; Arain, Rafee

    2008-09-01

    A micellar electrokinetic capillary chromatographic (MEKC) procedure has been developed for the separation and determination of dioxouranium (VI), iron(III), copper(II), and nickel(II) using bis(salicylaldehyde)propylenediimine (H2SA2Pn) as chelating reagent with a total run time of <3 min. Sodium dodecyl sulphate (SDS) was used as micellar medium at pH 8.1 with sodium tetraborate buffer (0.1 M). Uncoated fused silica capillary with effective length 38.8 cmx75 microm id was used with an applied voltage of 30 kV and photo-diode array detection at 228 nm. Linear calibrations were established within 0.045-1000 microg/mL of each element with detection limit within 15-122 ng/mL. The method was applied to the analysis of spring water and rock samples. The presence of uranium in rock and spring water samples was established within 1.58-1739.3 microg/g and 0.047-0.712 microg/mL with relative standard deviation within 0.9-2.1% and 1.3-2.6% respectively. Uranium ore and water samples were also assayed by the standard addition technique. Recovery of uranium was >98% with RSD up to 2.7%. Copper, nickel, and iron in their combined matrix were concurrently determined within RSD 0.6-3.6% (n=5) and the results obtained were compared with those of flame AAS. PMID:18785150

  13. Graphene-coated fiber for solid-phase microextraction of triazine herbicides in water samples.

    PubMed

    Wu, Qiuhua; Feng, Cheng; Zhao, Guangying; Wang, Chun; Wang, Zhi

    2012-01-01

    Graphene is a novel and interesting carbon material that could be used for the separation and purification of some chemical compounds. In this investigation, graphene was used as a novel fiber-coating material for the solid-phase microextraction (SPME) of four triazine herbicides (atrazine, prometon, ametryn and prometryn) in water samples. The main parameters that affect the extraction and desorption efficiencies, such as the extraction time, stirring rate, salt addition, desorption solvent and desorption time, were investigated and optimized. The optimized SPME by graphene-coated fiber coupled with high-performance liquid chromatography-diode array detection (HPLC-DAD) was successfully applied for the determination of the four triazine herbicides in water samples. The linearity of the method was in the range from 0.5 to 200 ng/mL, with the correlation coefficients (r) ranging from 0.9989 to 0.9998. The limits of detection of the method were 0.05-0.2 ng/mL. The relative standard deviations varied from 3.5 to 4.9% (n=5). The recoveries of the triazine herbicides from water samples at spiking levels of 20.0 and 50.0  ng/mL were in the range between 86.0 and 94.6%. Compared with two commercial fibers (CW/TPR, 50 μm; PDMS/DVB, 60 μm), the graphene-coated fiber showed higher extraction efficiency. PMID:22162195

  14. Data for periphyton and water samples collected from the south Florida ecosystem, 1995 and 1996

    USGS Publications Warehouse

    Simon, N.S.; Cox, T.; Spencer, R.

    1998-01-01

    This report presents data for samples of periphyton and water collected in 1995 and 1996 from Water Conservation Areas, the Big Cypress National Preserve, and the Everglades National Park in south Florida. Periphyton samples were analyzed for concentrations of total mercury, methyl mercury, nitrogen, phosphorus, organic carbon, and inorganic carbon . Water-column samples collected on the same dates as the periphyton samples were analyzed for concentrations of major ions.

  15. Rapid recovery of cyanobacterial pigments in desiccated biological soil crusts following addition of water.

    PubMed

    Abed, Raeid M M; Polerecky, Lubos; Al-Habsi, Amal; Oetjen, Janina; Strous, Marc; de Beer, Dirk

    2014-01-01

    We examined soil surface colour change to green and hydrotaxis following addition of water to biological soil crusts using pigment extraction, hyperspectral imaging, microsensors and 13C labeling experiments coupled to matrix-assisted laser desorption and ionization time of flight-mass spectrometry (MALD-TOF MS). The topsoil colour turned green in less than 5 minutes following water addition. The concentrations of chlorophyll a (Chl a), scytonemin and echinenon rapidly increased in the top <1 mm layer while in the deeper layer, their concentrations remained low. Hyperspectral imaging showed that, in both wet and dehydrated crusts, cyanobacteria formed a layer at a depth of 0.2-0.4 mm and this layer did not move upward after wetting. 13C labeling experiments and MALDI TOF analysis showed that Chl a was already present in the desiccated crusts and de novo synthesis of this molecule started only after 2 days of wetting due to growth of cyanobacteria. Microsensor measurements showed that photosynthetic activity increased concomitantly with the increase of Chl a, and reached a maximum net rate of 92 µmol m-2 h-1 approximately 2 hours after wetting. We conclude that the colour change of soil crusts to green upon water addition was not due to hydrotaxis but rather to the quick recovery and reassembly of pigments. Cyanobacteria in crusts can maintain their photosynthetic apparatus intact even under prolonged periods of desiccation with the ability to resume their photosynthetic activities within minutes after wetting. PMID:25375172

  16. Growth control of nonionic reverse micelles by surfactant and solvent molecular architecture and water addition.

    PubMed

    Shrestha, Lok Kumar; Shrestha, Rekha Goswami; Aramaki, Kenji

    2011-06-01

    This paper describes a facile route to the shape, size, and structure control of reversed micelles by surfactant and solvent molecular architecture and water addition. Nonionic reverse micellar size is found to increase with increase in hydrophilic headgroup size of surfactant, whose scheme is understood in terms of decrease in the critical packing parameter (cpp). On the other hand, an opposite trend is observed with increase in lipophilicity of the surfactant. This is caused by the repulsive excluded volume interactions, which increases with the volume of lipophilic moiety of surfactant; as a result, the micelle interface tends to become more curved and micelles shrink. Solvent molecular structure has played a crucial role; increasing hydrocarbon chain length of alkanes favored one dimensional micellar growth. We note that long chain oil has a poor penetration tendency to lipophilic tail of surfactant and decreases the cpp. Solvent polarity is also crucial; globular micelles are formed in short chain oil cyclohexane. We note that decreasing chain length of oil mimic the decrease in the headgroup size of surfactant; rod-to-sphere type transition in the micellar structure. Addition of trace water favors micellar growth; maximum dimension and micellar cross section increases with increase in water concentration. The sizes of the water incorporated reverse micelles (or w/o microemulsion) are much bigger than the empty micelles. Micellar structure was confirmed by small angle X-ray scattering (SAXS) and supported by rheology. PMID:21770115

  17. Phthalate esters detected in various water samples and biodegradation of the phthalates by microbes isolated from river water.

    PubMed

    Hashizume, Kiyomatsu; Nanya, Jo; Toda, Chitose; Yasui, Teruyo; Nagano, Hideo; Kojima, Nakao

    2002-02-01

    Phthalate esters (PEs), especially di-n-butyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP) were detected in various water samples such as river water, well water and tap water. On degradation tests of PEs, Tempaku River water degraded almost 100% of diethyl phthalate (DEP), di-isobutyl phthalate and DBP, and approximately 70% of DEHP. All eight isolates from Tempaku River water (R1-R7, D1) did not degrade dimethyl phthalate (DMP), but showed biodegrading ability for the other PEs. The DBP-degrading ability was particularly high for the isolates R1-R3 and D1 of Acinetobacter iwoffii. Crude enzyme solutions prepared from bacterial cells of these isolates showed a higher degrading activity for DEHP compared with that for microbially-degradable DBP. Particularly high DEHP-degrading activity was found for crude enzyme solutions of the isolate D1. As metabolites from the river water and bacterial isolates, DMP and an unknown diester were produced from DEP. DMP, DEP, monomethyl phthalate, monobutyl phthalate (MBP) and an unknown diester were produced from DBP. DBP, DEP, DMP and an unknown diester were produced from DEHP. As metabolites by the crude enzyme solutions, DMP, MBP and an unknown diester derivative were produced from DBP. DBP, mono-(2-ethylhexyl) phthalate and an unknown diester derivative were produced from DEHP. Diesters with shortened alkyl carbon chains were also found as metabolites by the isolates and their crude enzyme solutions. The results suggest that the alkyl chains in the diesters are also decomposed in addition to monoester formation from DBP or DEHP at the first step reported for animals and some types of bacteria. PMID:11853168

  18. Water adsorption at high temperature on core samples from The Geysers geothermal field

    SciTech Connect

    Gruszkiewicz, M.S.; Horita, J.; Simonson, J.M.; Mesmer, R.E.

    1998-06-01

    The quantity of water retained by rock samples taken from three wells located in The Geysers geothermal field, California, was measured at 150, 200, and 250 C as a function of steam pressure in the range 0.00 {le} p/p{sub 0} {le} 0.98, where p{sub 0} is the saturated water vapor pressure. Both adsorption and desorption runs were made in order to investigate the extent of the hysteresis. Additionally, low temperature gas adsorption analyses were made on the same rock samples. Mercury intrusion porosimetry was also used to obtain similar information extending to very large pores (macropores). A qualitative correlation was found between the surface properties obtained from nitrogen adsorption and the mineralogical and petrological characteristics of the solids. However, there was no direct correlation between BET specific surface areas and the capacity of the rocks for water adsorption at high temperatures. The hysteresis decreased significantly at 250 C. The results indicate that multilayer adsorption, rather than capillary condensation, is the dominant water storage mechanism at high temperatures.

  19. Water adsorption at high temperature on core samples from The Geysers geothermal field

    SciTech Connect

    Gruszkiewicz, M.S.; Horita, J.; Simonson, J.M.; Mesmer, R.E.

    1998-06-01

    The quantity of water retained by rock samples taken from three wells located in The Geysers geothermal reservoir, California, was measured at 150, 200, and 250 C as a function of pressure in the range 0.00 {le} p/p{sub 0} {le} 0.98, where p{sub 0} is the saturated water vapor pressure. Both adsorption (increasing pressure) and desorption (decreasing pressure) runs were made in order to investigate the nature and the extent of the hysteresis. Additionally, low temperature gas adsorption analyses were performed on the same rock samples. Nitrogen or krypton adsorption and desorption isotherms at 77 K were used to obtain BET specific surface areas, pore volumes and their distributions with respect to pore sizes. Mercury intrusion porosimetry was also used to obtain similar information extending to very large pores (macropores). A qualitative correlation was found between the surface properties obtained from nitrogen adsorption and the mineralogical and petrological characteristics of the solids. However, there is in general no proportionality between BET specific surface areas and the capacity of the rocks for water adsorption at high temperatures. The results indicate that multilayer adsorption rather than capillary condensation is the dominant water storage mechanism at high temperatures.

  20. Detection of triazole deicing additives in soil samples from airports with low, mid, and large volume aircraft deicing activities.

    PubMed

    McNeill, K S; Cancilla, D A

    2009-03-01

    Soil samples from three USA airports representing low, mid, and large volume users of aircraft deicing fluids (ADAFs) were analyzed by LC/MS/MS for the presence of triazoles, a class of corrosion inhibitors historically used in ADAFs. Triazoles, specifically the 4-methyl-1H-benzotriazole and the 5-methyl-1H-benzotriazole, were detected in a majority of samples and ranged from 2.35 to 424.19 microg/kg. Previous studies have focused primarily on ground and surface water impacts of larger volume ADAF users. The detection of triazoles in soils at low volume ADAF use airports suggests that deicing activities may have a broader environmental impact than previously considered. PMID:19082516

  1. LABORATORY ANALYSIS FOR ARSENIC IN DRINKING WATER SAMPLES

    EPA Science Inventory

    The U.S. Environmental Protection Agency (USEPA) has established maximum contaminant levels ( MCLs ), for many inorganic contaminants found in drinking water, to protect the health of consumers. Some of these chemicals occur naturally in source waters while some are the result o...

  2. Precision of a splitting device for water samples

    USGS Publications Warehouse

    Capel, Paul D.; Nacionales, Fernando C.; Larson, Steven J.

    1995-01-01

    Two identical cone splitters, devices designed to split water and its suspended solids into equal aliquots for semi-volatile organic chemical and trace element analyses, were evaluated for their precision. The water-splitting evaluations consisted of experiments to test the effect of water volume, the effect of combining outlet ports, and the effect of different techniques of water introduction. The solids-splitting evaluations consisted of experi- ments to test the effect of particle size (nine different particle diameters ranging from very coarse sand to clay) and suspended-solids concentration. In general, water was equally split with a precision of less than 5 percent relative standard deviation. The accuracy of splitting the solids was a function of particle size. Clay, silt, and fine and medium sand were split with a precision relative standard deviation of less than 7 percent, and coarse sand was split with a relative standard deviation between 12 and 45 percent.

  3. Preparation and tribological properties of water-soluble copper/silica nanocomposite as a water-based lubricant additive

    NASA Astrophysics Data System (ADS)

    Zhang, Chunli; Zhang, Shengmao; Yu, Laigui; Zhang, Zhijun; Wu, Zhishen; Zhang, Pingyu

    2012-10-01

    Cu/SiO2 nanocomposite was synthesized by sol-gel method. The size, morphology and phase structure of as-prepared Cu/SiO2 nanocomposite were analyzed by means of X-ray diffraction and transmission electron microscopy, and its ultraviolet-visible light spectrum was measured in relation to surface plasmon excitation of Cu particles. The tribological properties of as-synthesized Cu/SiO2 nanocomposite as an additive in distilled water were investigated with a four-ball machine, and the morphology and elemental composition of worn steel surfaces were examined with a scanning electron microscope and an X-ray photoelectron spectroscope. Results show that as-synthesized Cu/SiO2 nanocomposite as a lubricant additive is able to significantly improve the tribological properties of distilled water. A protective and lubricious film composed of Cu and a small amount of FeS, FeSO4 and SiO2 is formed on steel sliding surfaces lubricated by distilled water containing Cu/SiO2 nanocomposite. During friction process Cu nanoparticles can be released from Cu/SiO2 nanocomposite to fill up micro-pits and grooves of steel sliding surfaces, resulting in greatly reduced friction and wear of steel frictional pair via self-repairing. The state and thickness of the film formed on the worn surface is closely related to applied load; and Cu/SiO2 nanocomposite might be a promising water-based lubricant additive for steel-steel contact subjected to moderate load.

  4. Suppression of methane/air explosion by ultrafine water mist containing sodium chloride additive.

    PubMed

    Cao, Xingyan; Ren, Jingjie; Zhou, Yihui; Wang, Qiuju; Gao, Xuliang; Bi, Mingshu

    2015-03-21

    The suppression effect of ultrafine mists on methane/air explosions with methane concentrations of 6.5%, 8%, 9.5%, 11%, and 13.5% were experimentally studied in a closed visual vessel. Ultrafine water/NaCl solution mist as well as pure water mist was adopted and the droplet sizes of mists were measured by phase doppler particle analyzer (PDPA). A high speed camera was used to record the flame evolution processes. In contrast to pure water mist, the flame propagation speed, the maximum explosion overpressure (ΔP(max)), and the maximum pressure rising rate ((dP/dt)max) decreased significantly, with the "tulip" flame disappearing and the flame getting brighter. The results show that the suppressing effect on methane explosion by ultrafine water/NaCl solution mist is influenced by the mist amount and methane concentration. With the increase of the mist amount, the pressure, and the flame speed both descended significantly. And when the mist amount reached 74.08 g/m(3) and 37.04 g/m(3), the flames of 6.5% and 13.5% methane explosions can be absolutely suppressed, respectively. All of results indicate that addition of NaCl can improve the suppression effect of ultrafine pure water mist on the methane explosions, and the suppression effect is considered due to the combination effect of physical and chemical inhibitions. PMID:25528229

  5. Autotrophic nitrogen removal from black water: calcium addition as a requirement for settleability.

    PubMed

    de Graaff, M S; Temmink, H; Zeeman, G; van Loosdrecht, M C M; Buisman, C J N

    2011-01-01

    Black (toilet) water contains half of the organic load in the domestic wastewater, as well as the major fraction of the nutrients nitrogen and phosphorus. When collected with vacuum toilets, the black water is 25 times more concentrated than the total domestic wastewater stream, i.e. including grey water produced by laundry, showers etc. A two-stage nitritation-anammox process was successfully employed and removed 85%-89% of total nitrogen in anaerobically treated black water. The (free) calcium concentration in black water was too low (42 mg/L) to obtain sufficient granulation of anammox biomass. The granulation and retention of the biomass was improved considerably by the addition of 39 mg/L of extra calcium. This resulted in a volumetric nitrogen removal rate of 0.5 gN/L/d, irrespective of the two temperatures of 35 °C and 25 °C at which the anammox reactors were operated. Nitrous oxide, a very strong global warming gas, was produced in situations of an incomplete anammox conversion accompanied by elevated levels of nitrite. PMID:20822793

  6. Numerical study of the effect of water addition on gas explosion.

    PubMed

    Liang, Yuntao; Zeng, Wen

    2010-02-15

    Through amending the SENKIN code of CHEMKIN III chemical kinetics package, a computational model of gas explosion in a constant volume bomb was built, and the detailed reaction mechanism (GRI-Mech 3.0) was adopted. The mole fraction profiles of reactants, some selected free radicals and catastrophic gases in the process of gas explosion were analyzed by this model. Furthermore, through the sensitivity analysis of the reaction mechanism of gas explosion, the dominant reactions that affect gas explosion and the formation of catastrophic gases were found out. At the same time, the inhibition mechanisms of water on gas explosion and the formation of catastrophic gases were analyzed. The results show that the induced explosion time is prolonged, and the mole fractions of reactant species such as CH(4), O(2) and catastrophic gases such as CO, CO(2) and NO are decreased as water is added to the mixed gas. With the water fraction in the mixed gas increasing, the sensitivities of the dominant reactions contributing to CH(4), CO(2) are decreased and the sensitivity coefficients of CH(4), CO and NO mole fractions are also decreased. The inhibition of gas explosion with water addition can be ascribed to the significant decrease of H, O and OH in the process of gas explosion due to the water presence. PMID:19811873

  7. Statistical analysis of stream water-quality data and sampling network design near Oklahoma City, central Oklahoma, 1977-1999

    USGS Publications Warehouse

    Brigham, Mark E.; Payne, Gregory A.; Andrews, William J.; Abbott, Marvin M.

    2002-01-01

    The sampling network was evaluated with respect to areal coverage, sampling frequency, and analytical schedules. Areal coverage could be expanded to include one additional watershed that is not part of the current network. A new sampling site on the North Canadian River might be useful because of expanding urbanization west of the city, but sampling at some other sites could be discontinued or reduced based on comparisons of data between the sites. Additional real-time or periodic monitoring for dissolved oxygen may be useful to prevent anoxic conditions in pools behind new low-water dams. The sampling schedules, both monthly and quarterly, are adequate to evaluate trends, but additional sampling during flow extremes may be needed to quantify loads and evaluate water-quality during flow extremes. Emerging water-quality issues may require sampling for volatile organic compounds, sulfide, total phosphorus, chlorophyll-a, Esherichia coli, and enterococci, as well as use of more sensitive laboratory analytical methods for determination of cadmium, mercury, lead, and silver.

  8. 40 CFR 258.53 - Ground-water sampling and analysis requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... mean levels for each constituent. (2) An analysis of variance (ANOVA) based on ranks followed by... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Ground-water sampling and analysis....53 Ground-water sampling and analysis requirements. (a) The ground-water monitoring program...

  9. 40 CFR 258.53 - Ground-water sampling and analysis requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... mean levels for each constituent. (2) An analysis of variance (ANOVA) based on ranks followed by... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Ground-water sampling and analysis....53 Ground-water sampling and analysis requirements. (a) The ground-water monitoring program...

  10. Transgenic nematodes as biosensors for metal stress in soil pore water samples.

    PubMed

    Anbalagan, Charumathi; Lafayette, Ivan; Antoniou-Kourounioti, Melissa; Haque, Mainul; King, John; Johnsen, Bob; Baillie, David; Gutierrez, Carmen; Martin, Jose A Rodriguez; de Pomerai, David

    2012-03-01

    Caenorhabditis elegans strains carrying stress-reporter green fluorescent protein transgenes were used to explore patterns of response to metals. Multiple stress pathways were induced at high doses by most metals tested, including members of the heat shock, oxidative stress, metallothionein (mtl) and xenobiotic response gene families. A mathematical model (to be published separately) of the gene regulatory circuit controlling mtl production predicted that chemically similar divalent metals (classic inducers) should show additive effects on mtl gene induction, whereas chemically dissimilar metals should show interference. These predictions were verified experimentally; thus cadmium and mercury showed additive effects, whereas ferric iron (a weak inducer) significantly reduced the effect of mercury. We applied a similar battery of tests to diluted samples of soil pore water extracted centrifugally after mixing 20% w/w ultrapure water with air-dried soil from an abandoned lead/zinc mine in the Murcia region of Spain. In addition, metal contents of both soil and soil pore water were determined by ICP-MS, and simplified mixtures of soluble metal salts were tested at equivalent final concentrations. The effects of extracted soil pore water (after tenfold dilution) were closely mimicked by mixtures of its principal component ions, and even by the single most prevalent contaminant (zinc) alone, though other metals modulated its effects both positively and negatively. In general, mixtures containing similar (divalent) metal ions exhibited mainly additive effects, whereas admixture of dissimilar (e.g. trivalent) ions often resulted in interference, reducing overall levels of stress-gene induction. These findings were also consistent with model predictions. PMID:22037694

  11. UMTRA project water sampling and analysis plan, Spook, Wyoming

    SciTech Connect

    Not Available

    1994-03-01

    Surface remedial action is complete at the Spook Uranium Mill Tailings Remedial Action Project site in Wyoming. Based on an evaluation of site characterization data, the US Nuclear Regulatory Commission, US Department of Energy, and state of Wyoming have concurred in the determination that a program to monitor ground water is not required because ground water in the uppermost aquifer is Class 3 (limited use) (40 CFR 192.21(g)(1993)).

  12. Improvement of pattern collapse issue by additive-added D.I. water rinse process

    NASA Astrophysics Data System (ADS)

    Tanaka, Keiichi; Naito, Ryoichiro; Kitada, Tomohiro; Kiba, Yukio; Yamada, Yoshiaki; Kobayashi, Masakazu; Ichikawa, Hiroyuki

    2003-06-01

    Reduction of critical dimension in lithography technology is aggressively promoted. At the same time, further resist thickness reduction is being pursued to increase the resolution capabilities of resist. However, thin film has its limitation because of etch requirements etc. As that result, the promotion of reduction results in increasing the aspect ratio, which leads to pattern collapse. It is well known that at drying step in developing process the capillary effect operates the photoresist pattern. If the force of the capillary effect is greater than the aggregation force of the resist pattern, the pattern collapse is generated. And the key parameters of the capillary effect are the space width between patterns, the aspect ratio, the contact angle of the D.I water rinse and the surface tension of rinse solution. Among these parameters the surface tension of rinse solution can be controlled by us. On the other hand, we've already reported that the penetration of TMAH and D.I water into the resist plays an important role on the lithographic latitude. For example, when we use the resist which TMA ion can be easily diffuse into, D.I water and TMA ion which are penetrated in the resist decreases the aggregation force of resist pattern and causes the pattern collapse even by the weak force against resist pattern. These results indicate that the swelling of photoresist by TMA ion and water is very important factor for controlling the pattern collapse. Currently, two methods are mainly tried to reduce the surface tension of rinse solution: SCF (Super Critical Fluid) and addition of additive to D.I water rinse. We used the latter method this time, because this technique has retrofittability and not special tool. And in this evaluation, we found that the degree of suppressing pattern collapse depends on the additive chemistry or formulation. With consideration given to process factors such as above, we investigated what factors contribute to suppressing pattern collapse

  13. Gasbuggy, New Mexico, Natural Gas and Produced Water Sampling Results for 2012

    SciTech Connect

    2012-12-01

    The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual natural gas sampling for the Gasbuggy, New Mexico, Site on June 20 and 21, 2012. This long-term monitoring of natural gas includes samples of produced water from gas production wells that are located near the site. Water samples from gas production wells were analyzed for gamma-emitting radionuclides, gross alpha, gross beta, and tritium. Natural gas samples were analyzed for tritium and carbon-14. ALS Laboratory Group in Fort Collins, Colorado, analyzed water samples. Isotech Laboratories in Champaign, Illinois, analyzed natural gas samples.

  14. Enhancement of nitrate removal at the sediment-water interface by carbon addition plus vertical mixing.

    PubMed

    Chen, Xuechu; He, Shengbing; Zhang, Yueping; Huang, Xiaobo; Huang, Yingying; Chen, Danyue; Huang, Xiaochen; Tang, Jianwu

    2015-10-01

    Wetlands and ponds are frequently used to remove nitrate from effluents or runoffs. However, the efficiency of this approach is limited. Based on the assumption that introducing vertical mixing to water column plus carbon addition would benefit the diffusion across the sediment-water interface, we conducted simulation experiments to identify a method for enhancing nitrate removal. The results suggested that the sediment-water interface has a great potential for nitrate removal, and the potential can be activated after several days of acclimation. Adding additional carbon plus mixing significantly increases the nitrate removal capacity, and the removal of total nitrogen (TN) and nitrate-nitrogen (NO3(-)-N) is well fitted to a first-order reaction model. Adding Hydrilla verticillata debris as a carbon source increased nitrate removal, whereas adding Eichhornia crassipe decreased it. Adding ethanol plus mixing greatly improved the removal performance, with the removal rate of NO3(-)-N and TN reaching 15.0-16.5 g m(-2) d(-1). The feasibility of this enhancement method was further confirmed with a wetland microcosm, and the NO3(-)-N removal rate maintained at 10.0-12.0 g m(-2) d(-1) at a hydraulic loading rate of 0.5 m d(-1). PMID:25556005

  15. Comparative study of pre-treatment procedures for (3)H monitoring in water samples from environmental protection programs.

    PubMed

    Tarancón, A; Bagán, H; Rauret, G; García, J F

    2010-04-15

    The determination of tritium activity in water samples is included in most environmental protection programs, and the recommended procedure consists of sample distillation and further measurement by liquid scintillation. Distillation is a simple but time consuming pre-treatment, especially in routine analysis. Here we evaluate alternative pre-treatments for tritium activity determination, such as filtration or the use of multiple selective ion exchange columns. 52 samples from different water sources (rain, surface, underground, sea and drinking water) in Spanish environmental protection programs, together with an IAEA reference material were analyzed. Results show that both pre-treatments can be applied as a preliminary tool to discriminate between tritium active and non active waters in environmental monitoring programs. In addition, filtration and multiple selective ion exchange column pre-treatments can be used as alternative procedures for tritium activity determination in the routine analyses of water samples with known and reproducible chemical and isotopic composition. Both methods are less time consuming than distillation and, in the case of filtration, extremely cheap. For waters with complex matrices, especially sea water, distillation is the recommended procedure due to the interference from salts contained in the sample. PMID:20167352

  16. Dendrite-Free Li Deposition Using Trace-Amounts of Water as an Electrolyte Additive

    SciTech Connect

    Qian, Jiangfeng; Xu, Wu; Bhattacharya, Priyanka; Engelhard, Mark H.; Henderson, Wesley A.; Zhang, Yaohui; Zhang, Jiguang

    2015-07-01

    Residual water presents in nonaqueous electrolytes has been widely regarded as a detrimental factor for lithium (Li) batteries. This is because water is highly reactive with the commonly used LiPF6 salt and leads to the formation of HF that corrodes battery materials. In this work, we demonstrate that a controlled trace-amount of water (25-100 ppm) can be an effective electrolyte additive for achieving dendrite-free Li metal deposition in LiPF6-based electrolytes and avoid its detrimental effect at the same time. Detailed analyses reveal that the trace amount of HF formed by the decomposition reaction of LiPF6 with water will be electrochemically reduced during initial Li deposition process to form a uniform and dense LiF-rich SEI layer on the surface of the substrate. This LiF-rich SEI layer leads to a uniform distribution of the electric field on the substrate surface and enables uniform and dendrite-free Li deposition. Meanwhile the detrimental effect of HF is diminished due to the consumption of HF in the LiF formation process. Microscopic analysis reveals that the as-deposited dendrite-free Li films exhibit a self-aligned and highly-compacted Li nanorods structure which is consistent with their charming blue color or known as structure color. These findings clearly demonstrate a novel approach to control the nucleation and grow process of Li metal films using well-controlled trace-amount of water. They also shine the light on the effect of water on other electrodeposition processes.

  17. CRITICAL EVALUATION OF DIFFERENTIAL PULSE POLAROGRAPHY FOR DETERMINING CHROMIUM(III) AND CHROMIUM(VI) IN WATER SAMPLES

    EPA Science Inventory

    The Tennessee Valley Authority critically evaluated differential pulse polarography for determining chromium(VI) and chromium(III) in water samples from coal-fired steam-electric generating stations. After addition of reagents to overcome interference, the peak currents for chrom...

  18. METALS IN GROUND WATER: SAMPLING ARTIFACTS AND REPRODUCIBILITY

    EPA Science Inventory

    Field studies evaluated sampling procedures for determination of aqueous inorganic geochemistry and assessment of contaminant transport by colloidal mobility. esearch at three different metal-contaminated sites has shown that 0.45 tm filtration has not removed potentially mobile ...

  19. WELL CONSTRUCTION AND PURGING EFFECTS ON GROUND-WATER SAMPLES

    EPA Science Inventory

    Multiple well installations of selected casing materials (i.e., polytetrafluoroethylene (PTFE), 304 stainless steel (SS), and polyvinyl chloride (PVC)) were constructed and sampled to determine if well purging and construction procedures would significantly bias chemical constitu...

  20. EVALUATING THE SAMPLING FREQUENCIES OF WATER QUALITY MONITORING NETWORKS

    EPA Science Inventory

    Sampling frequency evaluation procedures presented use a number of simplifying assumptions and basic statistical methods. Employing such an approach will facilitate use of these procedures and, therefore, set the stage for wider understanding and use of more sophisticated approac...

  1. EVALUATION OF FISH SAMPLING DESIGNS FOR COASTAL WATERS

    EPA Science Inventory

    Because no objective assessment of fish sampling methodologies has been completed for Great Lakes coastal wetlands we evaluated catches from several techniques and studies to determine the most effective combinations for these habitats. Data from six underdeveloped sites in Green...

  2. Characterization of paint samples used in drinking water reservoirs: identification of endocrine disruptor compounds.

    PubMed

    Romero, J; Ventura, F; Gomez, M

    2002-04-01

    Several migration tests are performed from various epoxy paint samples that, according to the regulation, can be used in food reservoirs such as drinking water reservoirs. The level of the organic compounds capable of producing migrations to water with special attention to endocrine disruptor compounds (EDCs) are identified and estimated by closed loop-stripping analysis (CLSA) and liquid-liquid extraction (LLE) methods coupled with gas chromatography (GC)-mass spectrometry (MS). Bisphenol A, a strong endocrine disruptor, is found in all migration experiments. Its concentration level reaches between 0.02 and 0.03 mg/cm2. The higher concentration corresponds with benzylic alcohol, which is used as a solvent and curing agent in epoxy paint. Other EDCs identified in the migration tests are phthalates, 4-nonylphenol, and t-butylphenol. The main non-EDCs identified are solvents, antioxidants, and rubber-like compounds. No great differences are found in the use of metallic plates or concrete slabs for migration experiments; only additional compounds related with the pretreatment of the concrete wall have been identified, too. In the study of a drinking water sample the same organic compounds identified in the migration test is not seen. This is probably because of the dynamic situation in a drinking water reservoir. Finally, a GC profile of a direct epoxy paint analysis is shown. The main peak identified is bisphenol A diglycidyl ether, monomer, and an active principle of the polymerization of epoxy resins based on bisphenol A. In addition, we report the recoveries of a selected group of EDCs using CLSA and LLE methods coupled with GC-MS. PMID:12004937

  3. Linkages Between Biotic and Abiotic Belowground Processes in a Mojave Desert Ecosystem: Responses to Experimental Nitrogen and Water Additions

    NASA Astrophysics Data System (ADS)

    Verburg, P. S.; Marion, G. M.; Young, A. C.; Glanzmann, I.; Stevenson, B.; Arnone, J. A.; Nowak, R. S.

    2007-05-01

    Fine roots play a critical role in nutrient acquisition and water uptake. Yet it is unclear how fine roots in arid environments respond to increased nitrogen deposition and rainfall, two important global change factors in arid lands in the southwestern United States. In addition it is unclear how changes in root activity may impact soil CO2 concentrations, an important parameter affecting carbonate dynamics. We measured fine root length density (RLD) and soil CO2 concentrations for two years in experimentally manipulated plots in a Mojave Desert ecosystem. The study was conducted at the Mojave Global Change Facility located at the Nevada Test Site 60 miles northwest of Las Vegas. The treatments included: 1) three 25 mm water additions during the summer, 2) one nitrogen addition in the fall equivalent to 40 kg per hectare per year, 3) a combined water and nitrogen addition and, 4) untreated controls. Root data were collected using minirhizotron imaging approximately every 90 days underneath shrubs and intershrub areas. Soil CO2 concentrations were collected at the same sampling times and locations at 10, 40 and 90 cm depth using gas wells. The RLD showed clear seasonal patterns with the fastest increase in RLD occurring between February and April. During the winter the increase in RLD was higher underneath shrubs than in intershrub areas but during the summer months increases in RLD were similar under shrubs and in intershrub areas. Water additions slightly increased root mortality during the summer but this increase in mortality was not large enough to cause consistent differences in RLD between control and irrigated plots. Nitrogen addition had no effect on root dynamics in any of the plots. In contrast to RLD, irrigation consistently increased soil CO2 concentrations at all depths during the summer even when roots were not actively growing anymore. We speculate that the increased mortality under irrigation causes increased heterotrophic respiration which may

  4. Detection of Escherichia coli in Biofilms from Pipe Samples and Coupons in Drinking Water Distribution Networks▿

    PubMed Central

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

    2007-01-01

    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 β-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

  5. UMTRA Project water sampling and analysis plan: Canonsburg and Burrell, Pennsylvania

    SciTech Connect

    Not Available

    1994-03-01

    Surface remedial action was completed at the Canonsburg and Burrell UMTRA Project sites in southwestern Pennsylvania in 1985 and 1987, respectively. Results of 1993 water sampling indicate ground water flow conditions and ground water quality at both sites have remained relatively consistent with time. Uranium concentrations in ground water continue to exceed the maximum concentration limit (MCL) at the Canonsburg site; no MCLs are exceeded in ground water at the Burrell site. Surface water quality shows no evidence of impact from the sites.

  6. Reconnaissance water sampling for radium-226 in central and northern Florida, December 1974-March 1976

    USGS Publications Warehouse

    Irwin, G.A.; Hutchinson, C.B.

    1976-01-01

    Analyses of 115 water samples collected from December 1974 through March 1976 in eight Florida Counties indicated that 22 samples (19 percent) had radium-226 activities equal to or in excess of 3 piC/liter (picocuries per liter), the concentration limit recommended for drinking water by the U.S. Public Health Service. The maximum radium-226 activity was 90 piC/liter in water from a shallow well in Polk County. The sampling reconnaissance was generally limited to areas of active phosphate mining and areas of undisturbed phosphate deposits. Most of the sampling was from water wells. Thirteen surface-water samples were collected in the Peace River drainage basin. The maximum radium-226 detected in surface-water samples was 3.6 piC/liter in Little Charlie Creek at State Road 664A in Hardee County. (Woodard-USGS)

  7. UMTRA Project water sampling and analysis plan, Grand Junction, Colorado. Revision 1, Version 6

    SciTech Connect

    1995-09-01

    This water sampling and analysis plan describes the planned, routine ground water sampling activities at the Grand Junction US DOE Uranium Mill Tailings Remedial Action (UMTRA) Project site (GRJ-01) in Grand Junction, Colorado, and at the Cheney Disposal Site (GRJ-03) near Grand Junction. The plan identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequencies for the routine monitoring stations at the sites. Regulatory basis is in the US EPA regulations in 40 CFR Part 192 (1994) and EPA ground water quality standards of 1995 (60 FR 2854). This plan summarizes results of past water sampling activities, details water sampling activities planned for the next 2 years, and projects sampling activities for the next 5 years.

  8. June 2011 Natural Gas and Produced Water Sampling at the Gasbuggy, New Mexico, Site

    SciTech Connect

    2011-10-01

    Annual natural gas and produced water monitoring was conducted for gas wells adjacent to Section 36, where the Gasbuggy test was conducted, in accordance with the draft Long-Term Surveillance and Maintenance Plan for the Gasbuggy Site, Rio Arriba County, New Mexico. Sampling and analysis were conducted as specified in the Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PLN/S04351, continually updated). Natural gas samples were collected for tritium and carbon-14 analyses. Produced water samples were collected and analyzed for tritium, gamma-emitting radionuclides (by high-resolution gamma spectrometry), gross alpha, and gross beta. A duplicate produced water sample was collected from well 30-039-21743. Produced water samples were not collected at locations 30-039-30161 and 30-039-21744 because of the lack of water. Samples were not collected from location 30-039-29988 because the well was shut-in.

  9. MICROBIOLOGICAL FIELD SAMPLING AND INSTRUMENTATION IN THE ASSESSMENT OF SOIL AND GROUND-WATER POLLUTION

    EPA Science Inventory

    This chapter emphasizes the importance of microbiological sampling of soil and ground water with respect to human heath risks, laws and regulations dealing with safe drinking water, and more prevalent subsurface monitoring activities associated with chlorinated organic compounds,...

  10. High-frequency isotopic analysis of liquid water samples in the field - initial results from continuous water sampling and cavity ring-down spectroscopy

    NASA Astrophysics Data System (ADS)

    von Freyberg, Jana; Studer, Bjørn; Kirchner, James

    2016-04-01

    Studying rapidly changing hydrochemical signals in catchments can help to improve our mechanistic understanding of their water flow pathways and travel times. For these purposes, stable water isotopes (18O and 2H) are commonly used as natural tracers. However, high-frequency isotopic analyses of liquid water samples are challenging. One must capture highly dynamic behavior with high precision and accuracy, but the lab workload (and sample storage artifacts) involved in collecting and analyzing thousands of bottled samples should also be avoided. Therefore, we have tested Picarro, Inc.'s newly developed Continuous Water Sampler Module (CoWS), which is coupled to their L2130-i Cavity Ring-Down Spectrometer to enable real-time on-line measurements of 18O and 2H in liquid water samples. We coupled this isotope analysis system to a dual-channel ion chomatograph (Metrohm AG, Herisau, Switzerland) for analysis of major cations and anions, as well as a UV-Vis spectroscopy system (s::can Messtechnik GmbH, Vienna, Austria) and electrochemical probes for characterization of basic water quality parameters. The system was run unattended for up to a week at a time in the laboratory and at a small catchment. At the field site, stream-water and precipitation samples were analyzed, alternating at sub-hourly intervals. We observed that measured isotope ratios were highly sensitive to the liquid water flow rate in the CoWS, and thus to the hydraulic head difference between the CoWS and the samples from which water was drawn. We used a programmable high-precision dosing pump to control the injection flow rate and eliminate this flow-rate artifact. Our experiments showed that the precision of the CoWS-L2130-i-system for 2-minute average values was typically better than 0.06‰ for δ18O and 0.16‰ for δ2H. Carryover effects were 1% or less between isotopically contrasting water samples for 30-minute sampling intervals. Instrument drift could be minimized through periodic analysis of

  11. Radiological sampling and analytical methods for National Primary Drinking Water Regulations.

    PubMed

    Blanchard, R L; Hahne, R M; Kahn, B; McCurdy, D; Mellor, R A; Moore, W S; Sedlet, J; Whittaker, E

    1985-05-01

    Radiological sampling and analysis performed under the National Interim Primary Drinking Water Regulations were evaluated for the U.S. Environmental Protection Agency (EPA) Office of Drinking Water to consider whether any changes should be recommended. The authors reviewed the analytical screening scheme; sample collection, storage and analysis procedures; selection of analytical methods; reliability of results; and possible future needs. The main problem in the program has been dependence on a screening scheme of gross alpha-particle activity measurement and 226Ra analysis for predicting elevated 228Ra levels to determine compliance with the maximum contaminant level (MCL) for Ra. In some aquifers, 228Ra levels have been found to be unrelated to 226Ra levels. Several alternatives are discussed to eliminate this problem. A secondary problem is that the measurement for assuring compliance with the MCL for gross alpha-particle activity minus Ra, Rn and U uses chemical U analysis and assumes equilibrium of 238U and 234U. Because some ground waters are known to be at disequilibrium, radiometric U analysis is needed for those gross alpha-particle activities and chemical U values that could result in an erroneous conclusion relative to the MCL. In addition, studies were recommended for determining analytical uncertainties and assuring reliable sampling and sample maintenance; improvements in the system for accepting methods were suggested; and methods were identified for several radionuclides not currently in the analytical program that may be needed to assure absence of elevated radiation doses and could be useful for identifying trace contaminants. PMID:3988523

  12. Quality-control design for surface-water sampling in the National Water-Quality Assessment Program

    USGS Publications Warehouse

    Mueller, David K.; Martin, Jeffrey D.; Lopes, Thomas J.

    1997-01-01

    The data-quality objectives of the National Water-Quality Assessment Program include estimating the extent to which contamination, matrix effects, and measurement variability affect interpretation of chemical analyses of surface-water samples. The quality-control samples used to make these estimates include field blanks, field matrix spikes, and replicates. This report describes the design for collection of these quality-control samples in National Water-Quality Assessment Program studies and the data management needed to properly identify these samples in the U.S. Geological Survey's national data base.

  13. Improving the performance of ammonia-water absorption cycles using salt additives and membranes

    SciTech Connect

    Ibrahim, O.M.; Barnett, S.M.; Balamuru, V.G.

    1997-12-31

    This paper proposes a new design of an ammonia-water absorption refrigeration cycle for low-temperature heat sources such as solar energy and waste heat. The proposed cycle uses a salt additive to shift the chemical equilibrium toward more effective separation of ammonia molecules from aqueous solution (i.e., salting out). Since salt additives can affect all aspects of the absorption cycle, membranes have been chosen to control the flow of ions in the cycle and limit their effects to the generation side. This paper describes an absorption cycle that uses membrane separation processes, such as reverse osmosis, dialysis, and electrodialysis. To optimize the performance of the cycle, however, the membranes and salts must be carefully chosen.

  14. Estimation of the hydrophobic fraction of dissolved organic matter in water samples using UV photometry.

    PubMed

    Dilling, Jörg; Kaiser, Klaus

    2002-12-01

    In this study, we tested a simple and rapid method for the estimation of carbon in the hydrophobic fraction of dissolved organic matter (DOM) of different origin (spruce, pine, and beech litter) in soil water. The method is based on the fact that the hydrophobic fraction of DOM contains almost entirely the aromatic moieties of DOM. Thus, it showed a clearly distinct light absorption at 260 nm compared to the hydrophilic fraction. This light absorption was directly proportional to the concentration of the hydrophobic fraction. Moreover, it was independent of the concentration of the hydrophilic fraction. We compared the concentrations of hydrophobic DOM estimated by the UV method with those of the conventional fractionation using chromatographic columns of XAD-8 macroporous resin and found an excellent agreement between the two methods for both solutions from laboratory sorption experiments and field samples of forest floor leachates and subsoil porewaters. In addition, the absorption at 260 nm of hydrophobic DOM proved to be independent of pH values ranging from 2.0 to 6.5. Compared to the conventional chromatographic fractionation, the method using the UV absorption at 260 nm is less time consuming, needs a much smaller sample volume, and showed a better reproducibility. However, its use is restricted to water samples of low nitrate (< 25 mg L(-1)) and Fe (< 5 mg L(-1)) concentrations and, probably, with the hydrophobic fraction dominated by aromatic compounds deriving from degradation of lignin. PMID:12448552

  15. Luminex detection of fecal indicators in river samples, marine recreational water, and beach sand.

    PubMed

    Baums, Iliana B; Goodwin, Kelly D; Kiesling, Traci; Wanless, David; Diaz, Mara R; Fell, Jack W

    2007-05-01

    Research to understand and remediate coastal pollution is moving toward a multitiered approach in which traditional enumeration of fecal indicators is accompanied by molecular analysis of a variety of targets. Technology that rapidly detects multiple microbial contaminants would benefit from such an approach. The Luminex 100 system is a suspension array that assays multiple analytes rapidly in a single well of a microtiter plate. The ability of the system to simultaneously detect multiple fecal indicating bacteria in environmental samples was tested. Primer/probe sets were designed to simultaneously detect the following fecal indicators: the Bacteroides fragilis group, Enterococcus spp., Escherichia coli and Shigella spp., Bacteroides distasonis, and Ent. faecalis. Specificity and sensitivity of the Luminex probes was tested against laboratory cultures. In addition, sequencing, culture plate testing, and specificity testing with environmental isolates were steps taken to validate the function of the assay with environmental samples. Luminex response to cultures and to environmental samples was consistent with sequencing results, suggesting that the technology has the potential to simultaneously detect multiple targets for coastal water quality applications, particularly as progress is made to efficiently extract DNA from water and sediment matrices. PMID:17350051

  16. The representativeness of pore water samples collected from the unsaturated zone using pressure-vacuum lysimeters

    USGS Publications Warehouse

    Peters, C.A.; Healy, R.W.

    1988-01-01

    Studies have indicated that the chemistry of water samples may be altered by the collection technique, creating concern about the representativeness of the pore water samples obtained. A study using soil water pressure-vacuum lysimeters in outwash sand and glacial till deposits demonstrates that for non-dilute-solution samples the effect of pH of sampling with lysimeters is minimal, and that measured major cation and anion concentrations are representative of the natural pore water; trace-metal concentrations can be significantly altered by collection procedures at low concentrations. -from Authors

  17. IMPROVED METHOD FOR THE STORAGE OF GROUND WATER SAMPLES CONTAINING VOLATILE ORGANIC ANALYTES

    EPA Science Inventory

    The sorption of volatile organic analytes from water samples by the Teflon septum surface used with standard glass 40-ml sample collection vials was investigated. Analytes tested included alkanes, isoalkanes, olefins, cycloalkanes, a cycloalkene, monoaromatics, a polynuclear arom...

  18. UMTRA Project water sampling and analysis plan, Gunnison, Colorado: Revision 1

    SciTech Connect

    Not Available

    1994-11-01

    This water sampling and analysis plan summarizes the results of previous water sampling activities and the plan for future water sampling activities, in accordance with the Guidance Document for Preparing Sampling and Analysis Plans for UMTRA Sites. A buffer zone monitoring plan for the Dos Rios Subdivision is included as an appendix. The buffer zone monitoring plan was developed to ensure continued protection to the public from residual contamination. The buffer zone is beyond the area depicted as contaminated ground water due to former milling operations. Surface remedial action at the Gunnison Uranium Mill Tailings Remedial Action Project site began in 1992; completion is expected in 1995. Ground water and surface water will be sampled semiannually at the Gunnison processing site and disposal site. Results of previous water sampling at the Gunnison processing site indicate that ground water in the alluvium is contaminated by the former uranium processing activities. Background ground water conditions have been established in the uppermost aquifer at the Gunnison disposal site. The monitor well locations provide a representative distribution of sampling points to characterize ground water quality and ground water flow conditions in the vicinity of the sites. The list of analytes has been modified with time to reflect constituents that are related to uranium processing activities and the parameters needed for geochemical evaluation.

  19. Water stable isotope measurements of Antarctic samples by means of IRMS and WS-CRDS techniques

    NASA Astrophysics Data System (ADS)

    Michelini, Marzia; Bonazza, Mattia; Braida, Martina; Flora, Onelio; Dreossi, Giuliano; Stenni, Barbara

    2010-05-01

    of the sample in the box. In the WS-CRDS the path of laser is longer, producing higher-sensitivity measurements. The instrument is paired with an autosampler and can be used without it and the vaporizer to analyze directly the isotopic composition of the water vapour in the atmosphere. In addition, the instrument can be moved from the laboratory and also used for outdoor measurements. The more important improvements over traditional IRMS techniques are that WS-CRDS needs less sample in order to perform the analysis (<2 ul vs. 3/5 ml); that it doesn't need manipulation of the sample (like the gas/water equilibration techniques) and the analyses are faster. Coversely, memory effects may affect the measurements so there is the need to increase the number of injection to have a high precision measurement. The laboratory of Isotope Geochemistry of the Department of Geosciences has recently acquired a WS-CRDS system from PICARRO. The isotopic data obtained with this new method have been compared with the ones obtained by means of IRMS methods. An HDO device coupled with a Thermo Finnigan Delta Plus Advantage mass spectrometer has been used, using the well know CO2 and H2/water equilibration technique. At the moment of the writing of the abstract the mean difference between the values obtained using PICARRO and using the traditional IRMS method is of the order of 0.1 per mil for the ratio 18O/16O and 1.00 per mil for the ratio D/H, but further measurements are currently underway. O'Keef A., Deacon D.A.G., 1988. Cavity ring-down optical spectrometer for absorption measurements using pulsed laser sources, Rev. Sci. Instrum., 59, 2544.

  20. 400 area secondary cooling water sampling and analysis plan

    SciTech Connect

    Penn, L.L.

    1996-10-29

    This is a total rewrite of the Sampling and Analysis Plan in response to, and to ensure compliance with, the State Waste Discharge Permit ST 4501 issued on July 31, 1996. This revision describes changes in facility status and implements requirements of the permit.

  1. Effect of water treatment additives on lime softening residual trace chemical composition--implications for disposal and reuse.

    PubMed

    Cheng, Weizhi; Roessler, Justin; Blaisi, Nawaf I; Townsend, Timothy G

    2014-12-01

    Drinking water treatment residues (WTR) offer potential benefits when recycled through land application. The current guidance in Florida, US allows for unrestricted land application of lime softening WTR; alum and ferric WTR require additional evaluation of total and leachable concentrations of select trace metals prior to land application. In some cases a mixed WTR is produced when lime softening is accompanied by the addition of a coagulant or other treatment chemical; applicability of the current guidance is unclear. The objective of this research was to characterize the total and leachable chemical content of WTR from Florida facilities that utilize multiple treatment chemicals. Lime and mixed lime WTR samples were collected from 18 water treatment facilities in Florida. Total and leachable concentrations of the WTR were measured. To assess the potential for disposal of mixed WTR as clean fill below the water table, leaching tests were conducted at multiple liquid to solid ratios and under reducing conditions. The results were compared to risk-based soil and groundwater contamination thresholds. Total metal concentrations of WTR were found to be below Florida soil contaminant thresholds with Fe found in the highest abundance at a concentration of 3600 mg/kg-dry. Aluminum was the only element that exceeded the Florida groundwater contaminant thresholds using SPLP (95% UCL = 0.23 mg/L; risk threshold = 0.2 mg/L). Tests under reducing conditions showed elevated concentrations of Fe and Mn, ranging from 1 to 3 orders of magnitude higher than SPLP leachates. Mixed lime WTR concentrations (total and leachable) were lower than the ferric and alum WTR concentrations, supporting that mixed WTR are appropriately represented as lime WTR. Testing of WTR under reducing conditions demonstrated the potential for release of certain trace metals (Fe, Al, Mn) above applicable regulatory thresholds; additional evaluation is needed to assess management options where

  2. The Influence of Pumping on Observed Bacterial Counts in Groundwater Samples: Implications for Sampling Protocol and Water Quality Interpretation

    NASA Astrophysics Data System (ADS)

    Kozuskanich, J.; Novakowski, K.; Anderson, B.

    2008-12-01

    Drinking water quality has become an important issue in Ontario following the events in Walkerton in 2000. Many rural communities are reliant on private groundwater wells for drinking water, and it is the responsibility of the owner to have the water tested to make sure it is safe for human consumption. Homeowners can usually take a sample to the local health unit for total coliform and E. Coli analysis at no charge to determine if the water supply is being tainted by surface water or fecal matter, both of which could indicate the potential for negative impacts on human health. However, is the sample coming out of the tap representative of what is going on the aquifer? The goal of this study is to observe how bacterial counts may vary during the course of well pumping, and how those changing results influence the assessment of water quality. Multiple tests were conducted in bedrock monitoring wells to examine the influence of pumping rate and pumped volume on observed counts of total coliform, E. Coli, fecal streptococcus, fecal coliform and heterotrophic plate count. Bacterial samples were collected frequently during the course of continuous purging events lasting up to 8 hours. Typical field parameters (temperature, salinity, pH, dissolved oxygen and ORP) were also continuously monitored during the course of each test. Common practice in groundwater studies is to wait until these parameters have stabilized or three well volumes have been removed prior to sampling, to ensure the sample is taken from new water entering the well from the aquifer, rather than the original water stored in the borehole prior to the test. In general, most bacterial counts were low, but did go above the drinking water standard of 0 counts/100mL (total coliform and E. Coli) at times during the tests. Results show the greatest variability in the observed bacterial counts at the onset of pumping prior to the removal of three well volumes. Samples taken after the removal of three well

  3. Effect of PAC addition on immersed ultrafiltration for the treatment of algal-rich water.

    PubMed

    Zhang, Yan; Tian, Jiayu; Nan, Jun; Gao, ShanShan; Liang, Heng; Wang, Meilian; Li, Guibai

    2011-02-28

    The aim of this study was to evaluate the effect of powdered activated carbon (PAC) addition on the treatment of algal-rich water by immersed ultrafiltration (UF), in terms of permeate quality and membrane fouling. Experiments were performed with a hollow-fiber polyvinyl chloride ultrafiltration membrane at a laboratory scale, 20-25°C and 10 L/(m(2) h) constant permeate flux. UF could achieve an absolute removal of Microcystis aeruginosa cells, but a poor removal of algogenic organic matter (AOM) released into water, contaminants responsible for severe membrane fouling. The addition of 4 g/L PAC to the immersed UF reactor significantly alleviated the development of trans-membrane pressure and enhanced the removal of dissovled organic carbon (by 10.9±1.7%), UV(254) (by 27.1±1.7%), and microcystins (expressed as MC-LR(eq), by 40.8±4.2%). However, PAC had little effect on the rejection of hydrophilic high molecular weight AOM such as carbohydrates and proteins. It was also identified that PAC reduced the concentrations of carbohydrates and proteins in the reactor due to decreased light intensity, as well as the MC-LR(eq) concentration by PAC adsorption. PMID:21216530

  4. Detection of Catabacter hongkongensis in polluted European water samples *

    PubMed Central

    Codony, Francesc; Adrados, Bárbara; Pérez, Leonardo Martín; Fittipaldi, Mariana; Morató, Jordi

    2009-01-01

    The Catabacteriaceae is a new bacterial family with a unique member: Catabacter hongkongensis is a strictly anaerobic, non-sporulating, Gram-positive coccobacillus that is phylogenetically related to some clostridial clusters. Little is known of its epidemiology and environmental distribution, but the inclusion of its 16S rRNA gene sequence in GenBank has allowed it to be detected qualitatively. As a first approach for prospective surveys, a real-time polymerase chain reaction (PCR) procedure to identify C. hongkongensis has been developed. The presence of Catabacteriaceae in 29 water bodies subjected to possible human or animal impact has been investigated. Four of them were positive. The results confirm that highly polluted water can contain C. hongkongensis. PMID:19946949

  5. Using Lagrangian sampling to study water quality during downstream transport in the San Luis Drain, California, USA

    USGS Publications Warehouse

    Volkmar, E.C.; Dahlgren, R.A.; Stringfellow, W.T.; Henson, S.S.; Borglin, S.E.; Kendall, C.; Van Nieuwenhuyse, E. E.

    2011-01-01

    To investigate the mechanism for diel (24h) changes commonly observed at fixed sampling locations and how these diel changes relate to downstream transport in hypereutrophic surface waters, we studied a parcel of agricultural drainage water as it traveled for 84h in a concrete-lined channel having no additional water inputs or outputs. Algal fluorescence, dissolved oxygen, temperature, pH, conductivity, and turbidity were measured every 30min. Grab samples were collected every 2h for water quality analyses, including nutrients, suspended sediment, and chlorophyll/pheophytin. Strong diel patterns were observed for dissolved oxygen, pH, and temperature within the parcel of water. In contrast, algal pigments and nitrate did not exhibit diel patterns within the parcel of water, but did exhibit strong diel patterns for samples collected at a fixed sampling location. The diel patterns observed at fixed sampling locations for these constituents can be attributed to algal growth during the day and downstream transport (washout) of algae at night. Algal pigments showed a rapid daytime increase during the first 48h followed by a general decrease for the remainder of the study, possibly due to sedimentation and photobleaching. Algal growth (primarily diatoms) was apparent each day during the study, as measured by increasing dissolved oxygen concentrations, despite low phosphate concentrations (<0.01mgL-1). ?? 2011 Elsevier B.V.

  6. Diesel engine experiments with oxygen enrichment, water addition and lower-grade fuel

    SciTech Connect

    Sekar, R.R.; Marr, W.W.; Cole, R.L.; Marciniak, T.J. ); Schaus, J.E. )

    1990-01-01

    The concept of oxygen enriched air applied to reciprocating engines is getting renewed attention in the context of the progress made in the enrichment methods and the tougher emissions regulations imposed on diesel and gasoline engines. An experimental project was completed in which a direct injection diesel engine was tested with intake oxygen levels of 21% -- 35%. Since an earlier study indicated that it is necessary to use a cheaper fuel to make the concept economically attractive, a less refined fuel was included in the test series. Since a major objection to the use of oxygen enriched combustion air had been the increase in NO{sub x} emissions, a method must be found to reduce NO{sub x}. Introduction of water into the engine combustion process was included in the tests for this purpose. Fuel emulsification with water was the means used here even though other methods could also be used. The teat data indicated a large increase in engine power density, slight improvement in thermal efficiency, significant reductions in smoke and particulate emissions and NO{sub x} emissions controllable with the addition of water. 15 refs., 10 figs., 2 tabs.

  7. GROUND-WATER SAMPLING BIAS OBSERVED IN SHALLOW, CONVENTIONAL WELLS

    EPA Science Inventory

    A previous field demonstration project on nitrate-based bioremediation of a fuel-contaminated aquifer used short-screened clustered well points in addition to shallow (10 foot), conventional monitoring wells to monitor the progress of remediation during surface application of rec...

  8. UMTRA Project water sampling and analysis plan, Belfield and Bowman, North Dakota

    SciTech Connect

    Not Available

    1994-08-01

    Surface remedial action is scheduled to begin at the Belfield and Bowman Uranium Mill Tailings Remedial Action (UMTRA) Project sites in the spring of 1996. Water sampling was conducted in 1993 at both the Belfield processing site and the Bowman processing/disposal site. Results of the sampling at both sites indicate that ground water conditions have remained relatively stable over time. Water sampling activities are not scheduled for 1994 because ground water conditions at the two sites are relatively stable, the 1993 sampling was comprehensive, and surface remediation activities are not scheduled to start until 1996. The next water sampling event is scheduled before the start of remedial activities and will include sampling selected monitor wells at both sites and several domestic wells in the vicinity.

  9. Analysis of pharmaceutical and other organic wastewater compounds in filtered and unfiltered water samples by gas chromatography/mass spectrometry

    USGS Publications Warehouse

    Zaugg, Steven D.; Phillips, Patrick J.; Smith, Steven G.

    2014-01-01

    Research on the effects of exposure of stream biota to complex mixtures of pharmaceuticals and other organic compounds associated with wastewater requires the development of additional analytical capabilities for these compounds in water samples. Two gas chromatography/mass spectrometry (GC/MS) analytical methods used at the U.S. Geological Survey National Water Quality Laboratory (NWQL) to analyze organic compounds associated with wastewater were adapted to include additional pharmaceutical and other organic compounds beginning in 2009. This report includes a description of method performance for 42 additional compounds for the filtered-water method (hereafter referred to as the filtered method) and 46 additional compounds for the unfiltered-water method (hereafter referred to as the unfiltered method). The method performance for the filtered method described in this report has been published for seven of these compounds; however, the addition of several other compounds to the filtered method and the addition of the compounds to the unfiltered method resulted in the need to document method performance for both of the modified methods. Most of these added compounds are pharmaceuticals or pharmaceutical degradates, although two nonpharmaceutical compounds are included in each method. The main pharmaceutical compound classes added to the two modified methods include muscle relaxants, opiates, analgesics, and sedatives. These types of compounds were added to the original filtered and unfiltered methods largely in response to the tentative identification of a wide range of pharmaceutical and other organic compounds in samples collected from wastewater-treatment plants. Filtered water samples are extracted by vacuum through disposable solid-phase cartridges that contain modified polystyrene-divinylbenzene resin. Unfiltered samples are extracted by using continuous liquid-liquid extraction with dichloromethane. The compounds of interest for filtered and unfiltered sample

  10. Additions of nutrients and major ions by the atmosphere and tributaries to nearshore waters of northwestern Lake Huron

    USGS Publications Warehouse

    Manny, Bruce A.; Owens, R.W.

    1983-01-01

    Nutrient additions by the atmosphere and six tributaries to nearshore waters of northwestern Lake Huron were measured at weekly intervals from August 1975 to July 1976. The atmosphere contributed 43% of the nitrogen (N) and 10% of the phosphorus (P) that was added during the year. The 1975–76 atmospheric loading rate of total N to this area (11 kg/ha/yr) was one of the highest found to date in the United States. N was conserved more efficiently than P in the tributary drainage basins. Of the N and P that fell annually on the watersheds under study, 2 to 37% of the N and 31 to 84% of the P was carried with runoff to the lake. From a basin where ditching and clear-cutting occurred, water, P, silica (SiO2), N, and sodium were lost at higher rates than from five other basins. Most of the N in bulk atmospheric samples (23%) and tributary waters (56%) was dissolved organic N, a form of N not often measured.

  11. Heat transfer characteristics for some coolant additives used for water cooled engines

    SciTech Connect

    Abou-Ziyan, H.Z.; Helali, A.H.B.

    1996-12-31

    Engine coolants contain certain additives to prevent engine overheating or coolant freezing in cold environments. Coolants, also, contain corrosion and rust inhibitors, among other additives. As most engines are using engine cooling solutions, it is of interest to evaluate the effect of engine coolants on the boiling heat transfer coefficient. This has its direct impact on radiator size and environment. This paper describes the apparatus and the measurement techniques. Also, it presents the obtained boiling heat transfer results at different parameters. Three types of engine coolants and their mixtures in distilled water are evaluated, under sub-cooled and saturated boiling conditions. A profound effect of the presence of additives in the coolant, on heat transfer, was clear since changes of heat transfer for different coolants were likely to occur. The results showed that up to 180% improvement of boiling heat transfer coefficient is experienced with some types of coolants. However, at certain concentrations other coolants provide deterioration or not enhancement in the boiling heat transfer characteristics. This investigation proved that there are limitations, which are to be taken into consideration, for the composition of engine coolants in different environments. In warm climates, ethylene glycol should be kept at the minimum concentration required for dissolving other components, whereas borax is beneficial to the enhancement of the heat transfer characteristics.

  12. Adsorption of peptides at the sample drying step: influence of solvent evaporation technique, vial material and solution additive.

    PubMed

    Pezeshki, Adel; Vergote, Valentijn; Van Dorpe, Sylvia; Baert, Bram; Burvenich, Christian; Popkov, Alexander; De Spiegeleer, Bart

    2009-04-01

    Although the efficient and careful removal of solvent from samples by centrifugal evaporation or freeze-drying methods is an important step in peptidomics, the recovery of peptides has not yet been fully investigated with these sample drying methods. Moreover, the surface adsorption of the peptides by the container and efforts to reduce this adsorption by organic additives is only scarcely elaborated until now. In this experiment, the recovery of five model peptides, i.e. bovine insulin, mouse obestatin, goserelin, buserelin and leucine-enkephalin was investigated applying dimethylsulfoxide (DMSO), dimethylformamide (DMF), polyethylene glycol 400 (PEG 400), mannitol and n-nonyl-beta-d-glucopyranoside (C(9)-Glu) in function of the two applied solvent evaporation processes (freeze-drying vs. centrifugal evaporation) and vial types, i.e. polypropylene (PP) and glass. Under our experimental conditions, drying resulted in a decreased recovery of the model peptides by 10% on average. Insulin showed the lowest recovery value relative to the other model peptides. For both drying methods, recovery of the model peptides was increased when C(9)-Glu was present. Overall, the use of PP vials is proposed for freeze-drying, while glass vials are found to be more suitable for centrifugal evaporation. The presence of PEG 400 in PP vials caused significantly reduced recoveries for all model peptides using centrifugal evaporation, although this was not observed in glass vials. As a general conclusion, applying C(9)-Glu as an additive along with choosing appropriate vial type (i.e. PP for lyophilization and glass for centrifugal evaporation) can avoid or diminish peptide loss during the evaporation procedure. PMID:19150589

  13. Towards a phylogenetic generic classification of Thelypteridaceae: Additional sampling suggests alterations of neotropical taxa and further study of paleotropical genera.

    PubMed

    Almeida, Thaís Elias; Hennequin, Sabine; Schneider, Harald; Smith, Alan R; Batista, João Aguiar Nogueira; Ramalho, Aline Joseph; Proite, Karina; Salino, Alexandre

    2016-01-01

    Thelypteridaceae is one of the largest fern families, having about 950 species and a cosmopolitan distribution but with most species occurring in tropical and subtropical regions. Its generic classification remains controversial, with different authors recognizing from one up to 32 genera. Phylogenetic relationships within the family have not been exhaustively studied, but previous studies have confirmed the monophyly of the lineage. Thus far, sampling has been inadequate for establishing a robust hypothesis of infrafamilial relationships within the family. In order to understand phylogenetic relationships within Thelypteridaceae and thus to improve generic reclassification, we expand the molecular sampling, including new samples of Old World taxa and, especially, many additional neotropical representatives. We also explore the monophyly of exclusively or mostly neotropical genera Amauropelta, Goniopteris, Meniscium, and Steiropteris. Our sampling includes 68 taxa and 134 newly generated sequences from two plastid genomic regions (rps4-trnS and trnL-trnF), plus 73 rps4 and 72 trnL-trnF sequences from GenBank. These data resulted in a concatenated matrix of 1980 molecular characters for 149 taxa. The combined data set was analyzed using maximum parsimony and bayesian inference of phylogeny. Our results are consistent with the general topological structure found in previous studies, including two main lineages within the family: phegopteroid and thelypteroid. The thelypteroid lineage comprises two clades; one of these included the segregates Metathelypteris, Coryphopteris, and Amauropelta (including part of Parathelypteris), whereas the other comprises all segregates of Cyclosorus s.l., such as Goniopteris, Meniscium, and Steiropteris (including Thelypteris polypodioides, previously incertae sedis). The three mainly neotropical segregates were found to be monophyletic but nested in a broadly defined Cyclosorus. The fourth mainly neotropical segregate, Amauropelta

  14. {sup 222}Rn in water: A comparison of two sample collection methods and two sample transport methods, and the determination of temporal variation in North Carolina ground water

    SciTech Connect

    Hightower, J.H. III

    1994-12-31

    Objectives of this field experiment were: (1) determine whether there was a statistically significant difference between the radon concentrations of samples collected by EPA`s standard method, using a syringe, and an alternative, slow-flow method; (2) determine whether there was a statistically significant difference between the measured radon concentrations of samples mailed vs samples not mailed; and (3) determine whether there was a temporal variation of water radon concentration over a 7-month period. The field experiment was conducted at 9 sites, 5 private wells, and 4 public wells, at various locations in North Carolina. Results showed that a syringe is not necessary for sample collection, there was generally no significant radon loss due to mailing samples, and there was statistically significant evidence of temporal variations in water radon concentrations.

  15. Estimation of uranium and radon concentration in some drinking water samples of Upper Siwaliks, India.

    PubMed

    Singh, Joga; Singh, Harmanjit; Singh, Surinder; Bajwa, B S

    2009-07-01

    Uranium and radon concentration was assessed in water samples taken from hand pumps, natural sources and wells collected from some areas of Upper Siwaliks, Northern India. Fission track registration technique was used to estimate the uranium content of water samples. The uranium concentration in water samples was found to vary from 1.08 +/- 0.03 to 19.68 +/- 0.12 microg l(-1). These values were compared with safe limit values recommended for drinking water. Most of the water samples were found to have uranium concentration below the safe limit of 15 microg l(-1) (WHO, World Health Organization, Guidelines for drinking-water quality (3rd ed.). Geneva, Switzerland: WHO, 2004). The radon estimation in these water samples was made using alpha-scintillometry to study its correlation with uranium. The radon concentration in these samples was found to vary from 0.87 +/- 0.29 to 32.10 +/- 1.79 Bq l(-1). The recorded values of radon concentration were within the recommended safe limit of 4 to 40 Bq l(-1) (UNSCEAR, United Nations Scientific Committee on the Effects of Atomic Radiations, Sources and effects of ionizing radiation. New York: United Nations, 1993). No direct correlation was found between uranium concentration and radon concentration in water samples belonging to Upper Siwaliks. The values of uranium and radon concentration in water were compared with that from the adjoining areas of Punjab state, India. PMID:18566903

  16. Automated syringe sampler. [remote sampling of air and water

    NASA Technical Reports Server (NTRS)

    Purgold, G. C. (Inventor)

    1981-01-01

    A number of sampling services are disposed in a rack which slides into a housing. In response to a signal from an antenna, the circutry elements are activated which provide power individually, collectively, or selectively to a servomechanism thereby moving an actuator arm and the attached jawed bracket supporting an evaculated tube towards a stationary needle. One open end of the needle extends through the side wall of a conduit to the interior and the other open end is maintained within the protective sleeve, supported by a bifurcated bracket. A septum in punctured by the end of the needle within the sleeve and a sample of the fluid medium in the conduit flows through the needle and is transferred to a tube. The signal to the servo is then reversed and the actuator arm moves the tube back to its original position permitting the septum to expand and seal the hole made by the needle. The jawed bracket is attached by pivot to the actuator to facilitate tube replacement.

  17. UMTRA Project water sampling and analysis plan, Gunnison, Colorado. Revision 2

    SciTech Connect

    1995-09-01

    Surface remedial action at the Gunnison Uranium Mill Tailings Remedial Action Project site began in 1992; completion is expected in 1995. Ground water and surface water will be sampled semiannually at the Gunnison processing site (GUN-01) and disposal site (GUN-08). Results of previous water sampling at the Gunnison processing site indicate that ground water in the alluvium is contaminated by the former uranium processing activities. Background ground water conditions have been established in the uppermost aquifer (Tertiary gravels) at the Gunnison disposal site. Semiannual water sampling is scheduled for the spring and fall. Water quality sampling is conducted at the processing site (1) to ensure protection of human health and the environment, (2) for ground water compliance monitoring during remedial action construction, and (3) to define the extent of contamination. At the processing site, the frequency and duration of sampling will be dependent upon the nature and extent of residual contamination and the compliance strategy chosen. The monitor well locations provide a representative distribution of sampling points to characterize ground water quality and ground water flow conditions in the vicinity of the sites. The list of analytes has been modified with time to reflect constituents that are related to uranium processing activities and the parameters needed for geochemical evaluation.

  18. Non-additive response of blends of rice and potato starch during heating at intermediate water contents: A differential scanning calorimetry and proton nuclear magnetic resonance study.

    PubMed

    Bosmans, Geertrui M; Pareyt, Bram; Delcour, Jan A

    2016-02-01

    The impact of different hydration levels, on gelatinization of potato starch (PS), rice starch (RS) and a 1:1 blend thereof, was investigated by differential scanning calorimetry and related to nuclear magnetic resonance proton distributions of hydrated samples, before and after heating. At 20% or 30% hydration, the visual appearance of all samples was that of a wet powder, and limited, if any, gelatinization occurred upon heating. At 30% hydration, changes in proton distributions were observed and related to plasticization of amorphous regions in the granules. At 50% hydration, the PS-RS blend appeared more liquid-like than other hydrated samples and showed more pronounced gelatinization than expected based on additive behavior of pure starches. This was due to an additional mobile water fraction in the unheated PS-RS blend, originating from differences in water distribution due to altered stacking of granules and/or altered hydration of PS due to presence of cations in RS. PMID:26304387

  19. H02 WETLAND TREATMENT SYSTEM WATER CHEMISTRY SAMPLING AND RESULTS REPORT

    SciTech Connect

    Bach, M; Michael Serrato, M; Eric Nelson, E

    2008-02-15

    inorganic chemistry influence on pH. In addition, alternative methods to alleviate or mitigate the pH increase were evaluated. This study documents the results of sampling activities undertaken and conveys the analytical results along with suggestions for operation of the H-02 Wetland Treatment System. The water samples collected and the water quality data generated from this activity are for analytical purposes only, and as such, were not collected in support of compliance activities.

  20. Analyses of water, core material, and elutriate samples collected near Yazoo City, Mississippi (Yazoo Headwater Project)

    USGS Publications Warehouse

    Leone, Harold L.; Dupuy, Alton J.

    1978-01-01

    Five core-material-sampling sites near Yazoo City, Miss., were chosen by the U.S. Army Corps of Engineers to represent areas of proposed dredging activity. Four receiving-water sites also were selected to represent the water that will contact the proposed dredged material. Chemical and physical analyses were performed upon core material and native-water samples from these sites as well as upon elutriate samples of specific sediment-receiving water systems. The results of these analyses are presented without interpretation. (Woodard-USGS)

  1. Chemical analyses of water samples from the Picher mining area, northeast Oklahoma and southeast Kansas

    USGS Publications Warehouse

    Parkhurst, David L.

    1987-01-01

    Chemical analyses are presented for 169 water samples from Tar Creek drainage and the Picher lead-zinc mining area of northeast Oklahoma and southeast Kansas. Water samples were taken from November 1983 through February 1986 from the abandoned mines, from points of mine-water discharge, and from surface-water locations upstream and downstream from mine discharge area. The pH, temperature, alkalinity, dissolved oxygen, and specific conductance were measured in the field. Laboratory analyses routinely included the major ions plus aluminum, cadmium, copper, iron, lead, manganese, nickel, and zinc. Non-routine analyses of dissolved gases and tritium are presented. Stable carbon-isotope ratios for 11 mine-water samples and three carbonate-rock samples are reported. Miscellaneous stream-discharge measurements made at the time of sampling or taken from gaging-station records are included in the report.

  2. Considerations for sampling inorganic constituents in ground water using diffusion samplers

    USGS Publications Warehouse

    Vroblesky, D.A.; Petkewich, M.D.; Campbell, T.R.

    2002-01-01

    Data indicate that nylon-screen and dialysis diffusion samplers are capable of obtaining concentrations of inorganic solutes in ground water from wells that closely correspond to concentrations obtained by low-flow sampling. Conservative solutes, such as chloride, can be sampled by filling the diffusion samplers with oxygenated water. The samplers should be filled with anaerobic water for sampling redoxsensitive solutes. Oxidation of iron within the samplers, either by using aerobic fill water or by in-well oxygenation events, can lead to erroneous iron concentrations. Lithologic and chemical heterogeneity and sampler placement depth can lead to differences between concentrations from diffusion samples and low-flow samples because of mixing during pumping. A disadvantage of regenerated cellulose dialysis samplers is that they can begin to biodegrade within the two weeks of deployment. Nylon-screen samplers buried beneath streambed sediment along the unnamed tributary in a discharge zone of arseniccontaminated ground water were useful in locating the specific discharge zone.

  3. UMTRA Project water sampling and analysis plan, Durango, Colorado. Revision 1

    SciTech Connect

    1995-09-01

    Planned, routine ground water sampling activities at the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project site in Durango, Colorado, are described in this water sampling and analysis plan. The plan identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequency for the routine monitoring stations at the site. The ground water data are used to characterize the site ground water compliance strategies and to monitor contaminants of potential concern identified in the baseline risk assessment (DOE, 1995a). Regulatory basis for routine ground water monitoring at UMTRA Project sites is derived from the US EPA regulations in 40 CFR Part 192 (1994) and EPA standards of 1995 (60 FR 2854). Sampling procedures are guided by the UMTRA Project standard operating procedures (SOP) (JEG, n.d.), the Technical Approach Document (TAD) (DOE, 1989), and the most effective technical approach for the site.

  4. Filtration of water-sediment samples for the determination of organic compounds

    USGS Publications Warehouse

    Sandstrom, Mark W.

    1995-01-01

    This report describes the equipment and procedures used for on-site filtration of surface-water and ground-water samples for determination of organic compounds. Glass-fiber filters and a positive displacement pumping system are suitable for processing most samples for organic analyses. An optional system that uses disposable in-line membrane filters is suitable for a specific gas chromatography/mass spectrometry, selected-ion monitoring analytical method for determination of organonitrogen herbicides. General procedures to minimize contamination of the samples include preparing a clean workspace at the site, selecting appropriate sample-collection materials, and cleaning of the equipment with detergent, tap water, and methanol.

  5. Stabilized liquid membrane device (SLMD) for the passive, integrative sampling of labile metals in water

    USGS Publications Warehouse

    Brumbaugh, W.G.; Petty, J.D.; Huckins, J.N.; Manahan, S.E.

    2002-01-01

    A stabilized liquid membrane device (SLMD) is described for potential use as an in situ, passive, integrative sampler for cadmium (Cd), cobalt (Co), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) in natural waters. The SLMD (patent pending) consists of a 2.5-cm-wide by 15-cm-long strip of low-density polyethylene (LDPE) layflat tubing containing 1 mL of an equal mixture (v/v) of oleic acid (cis-9-octadecenoic acid) and EMO-8Q (7-[4-ethyl-1-methyloctyl]-8-quinolinol). The reagent mixture continuously diffuses to the exterior surface of the LDPE membrane, and provides for sequestration of several divalent metals for up to several weeks. Depending on sampler configuration, concentration factors of several thousand can be realized for these metal ions after just a few days. In addition to in situ deployment, the SLMD may be useful for laboratory determination of labile metal species in grab samples. Methods for minimizing the effects of water flow on the sampling rate are currently under investigation.

  6. Polymer growth rate in a wire chamber with oxygen, water, or alcohol gas additives

    NASA Astrophysics Data System (ADS)

    Boyarski, Adam M.

    2009-06-01

    The rate of polymer growth on wires was measured in a wire chamber while the chamber was aged initially with helium:isobutane (80:20) gas, and then with either oxygen, water, or alcohol added to the gas. At the completion of the aging process for each gas mixture, the carbon content on the wires was measured in a scanning electron microscope/energy dispersive X-ray (SEM/EDX) instrument. The same physical wires were used in all the gas mixtures, allowing measurement of polymer build-up or polymer depletion by each gas additive. It is found that the rate of polymer growth is not changed by the presence of oxygen, water, or alcohol. Conjecture that oxygen reduces breakdown by removing polymer deposits on field wires is negated by these measurements. Instead, it appears that the reduced breakdown is due to lower resistance in the polymer from oxygen ions being transported into the polymer. It is also observed that field wires bombarded by the electrons in the SEM and then placed back into the chamber show an abundance of single electrons being emitted, indicating that electron charge is trapped in the polymer layer and that a high electric field is necessary to remove the charge.

  7. Polymer Growth Rate in a Wire Chamber with Oxygen,Water, or Alcohol Gas Additives

    SciTech Connect

    Boyarski, Adam; /SLAC

    2008-07-02

    The rate of polymer growth on wires was measured in a wire chamber while the chamber was aged initially with helium-isobutane (80:20) gas, and then with either oxygen, water, or alcohol added to the gas. At the completion of the aging process for each gas mixture, the carbon content on the wires was measured in a SEM/EDX instrument. The same physical wires were used in all the gas mixtures, allowing measurement of polymer build up or polymer depletion by each gas additive. It is found that the rate of polymer growth is not changed by the presence of oxygen, water or alcohol. Conjecture that oxygen reduces breakdown by removing polymer deposits on field wires is negated by these measurements. Instead, it appears that the reduced breakdown is due to lower resistance in the polymer from oxygen ions being transported into the polymer. It is also observed that field wires bombarded by the electrons in the SEM and then placed back into the chamber show an abundance of single electrons being emitted, indicating that electron charge is stored in the polymer layer and that a high electric field is necessary to remove the charge.

  8. Vigorous Mold Growth in Soils After Addition of Water-Insoluble Fatty Substances

    PubMed Central

    Krause, Frank P.; Lange, Willy

    1965-01-01

    Various water-insoluble fatty compounds, when added to soil in finely divided form, will support as high-caloric nutrients a visible, vigorous growth of the molds, Fusarium solani Mart., F. diversisporum Sherb., and F. equiseti. n-Paraffins and olefins are most effective, because the effect of additives is reduced to the extent that oxygen atoms are introduced into the molecule. n-Fatty alcohols support growth in soil almost as well as the paraffins; however, growth is reduced when branched-chain compounds are added as nutrients. Compounds that will support mold growth when added to air-dried soil as finely powdered solids will not do so when incorporated at temperatures above their melting point, but will produce dense growth when applied to wet soil in this form. Mold growth is correlated with degradation of fatty matter. The rate of degradation is controlled by the availability of water, oxygen, and the basic inorganic nutrients. Images Fig. 1 Fig. 2 PMID:14325872

  9. AUTOMATED SYSTEM FOR COLLECTING MULTIPLE, SEQUENTIAL SAMPLES FROM SOIL WATER SAMPLERS UNDER CONTINUOUS VACUUM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Manually collecting a series of sequential, discrete water samples from soil water percolation samplers, or similar devices, that withdraw water from unsaturated porous media under continuous vacuum is a logistical challenge, though the resulting collection can provide valuable information on the dy...

  10. [Distribution of Phosphorus Forms in the Overlying Water Under Disturbance with the Addition of Algae].

    PubMed

    Chen, Jun; Li, Yong; Li, Da-peng; Huang, Yong; Zhu, Pei-ying

    2016-04-15

    Distribution of different phosphorus (P) forms in the overlying water and the contribution of different algae to the P disappearance were investigated under disturbance with the addition of algae (Microcystis aeruginosa and Selenastrum capricornutum, respectively). The sediments and overlying water were taken from Meiliang Bay in Taihu Lake. The results showed that the concentrations of total P (TP), dissolved total P (DTP), dissolved inorganic P (DIP) and biavailable P (BAP) decreased with and without disturbance. The uptake of DTP and DIP by Microcystis aeruginosa was better than that of Selenastrum capricornutum under the disturbance, but it was the opposite without the disturbance. The disappearance of P in the overlying water was attributed completely to the physico-chemical adsorption of the suspended solids and the uptake of algae. But the contribution of suspended solids and algae depended on the disturbance. The contribution of Microcystis aeruginosa and Selenastrum capricornutum to DTP and DIP absorption was about 60% without disturbance. However, the value was reduced to 40% (Microcystis aeruginosa) and 25% ( Selenastrum capricornutum) under the disturbance. Under the disturbance and the action of algae, the distribution of sedimentary P forms changed. NH4 Cl-P and Ca-P release and Fe/Al-P increase were observed with and without disturbance. The decrease of NH4 Cl-P and Ca-P and the increase of Fe/Al-P were more obvious with disturbance than without disturbance. Selenastrum capricornutum was favor of the release of Ca-P and the formation of Fe/Al-P. PMID:27548963

  11. Assessment of PDMS-water partition coefficients: implications for passive environmental sampling of hydrophobic organic compounds

    USGS Publications Warehouse

    DiFilippo, Erica L.; Eganhouse, Robert P.

    2010-01-01

    Solid-phase microextraction (SPME) has shown potential as an in situ passive-sampling technique in aquatic environments. The reliability of this method depends upon accurate determination of the partition coefficient between the fiber coating and water (Kf). For some hydrophobic organic compounds (HOCs), Kf values spanning 4 orders of magnitude have been reported for polydimethylsiloxane (PDMS) and water. However, 24% of the published data examined in this review did not pass the criterion for negligible depletion, resulting in questionable Kf values. The range in reported Kf is reduced to just over 2 orders of magnitude for some polychlorinated biphenyls (PCBs) when these questionable values are removed. Other factors that could account for the range in reported Kf, such as fiber-coating thickness and fiber manufacturer, were evaluated and found to be insignificant. In addition to accurate measurement of Kf, an understanding of the impact of environmental variables, such as temperature and ionic strength, on partitioning is essential for application of laboratory-measured Kf values to field samples. To date, few studies have measured Kf for HOCs at conditions other than at 20 degrees or 25 degrees C in distilled water. The available data indicate measurable variations in Kf at different temperatures and different ionic strengths. Therefore, if the appropriate environmental variables are not taken into account, significant error will be introduced into calculated aqueous concentrations using this passive sampling technique. A multiparameter linear solvation energy relationship (LSER) was developed to estimate log Kf in distilled water at 25 degrees C based on published physicochemical parameters. This method provided a good correlation (R2 = 0.94) between measured and predicted log Kf values for several compound classes. Thus, an LSER approach may offer a reliable means of predicting log Kf for HOCs whose experimental log Kf values are presently unavailable. Future

  12. Physicochemical Characterization of Lake Spray Aerosol Generated from Great Lakes Water Samples

    NASA Astrophysics Data System (ADS)

    Ault, A. P.; Axson, J. L.; May, N.; Pratt, K.

    2014-12-01

    Wave breaking across bodies of water releases particles into the air which can impact climate and human health. Similar to sea spray aerosols formed through marine wave breaking, freshwater lakes generate lake spray aerosol (LSA). LSA can impact climate directly through scattering/absorption and indirectly through cloud nucleation. In addition, these LSA are suggested to impact human health through inhalation of these particles during algal bloom periods characterized by toxic cyanobacteria. Few studies have been conducted to assess the physical and chemical properties of freshwater LSA. Herein, we discuss constructing a LSA generation system and preliminary physical and chemical characterization of aerosol generated from water samples collected at various sites across Lake Erie, Lake Huron, Lake Superior, and Lake Michigan. Information on aerosol size distributions, number concentrations, and chemical composition will be discussed as a function of lake water blue-green algae concentration, dissolved organic carbon concentration, temperature, conductivity, and dissolved oxygen concentration. These studies represent a first step towards evaluating the potential for LSA to impact climate and health in the Great Lakes region.

  13. Miniaturised enzymatic conductometric biosensor with Nafion membrane for the direct determination of formaldehyde in water samples.

    PubMed

    Nguyen-Boisse, Thanh-Thuy; Saulnier, Joëlle; Jaffrezic-Renault, Nicole; Lagarde, Florence

    2014-02-01

    A new conductometric enzyme-based biosensor was developed for the determination of formaldehyde (FA) in aqueous solutions. The biosensor was prepared by cross-linking formaldehyde dehydrogenase from Pseudomonas putida with bovine serum albumin in saturated glutaraldehyde vapours (GA) at the surface of interdigitated gold microelectrodes. Nicotinamide adenine dinucleotide cofactor (NAD(+)) was added in solution at each measurement to maintain enzyme activity. Addition of a Nafion layer over the enzyme modified electrode resulted in a significant increase of biosensor signal due to enhanced accumulation of protons generated by enzymatic reaction at the electrode surface. Different parameters affecting enzyme activity or playing a role in ionic transfer through the Nafion membrane were optimised. In optimal conditions (0.045 mg enzyme, 30 min exposure to GA, 0.3 μL of a 1% (v/v) Nafion solution deposit, measurement in 5 mM phosphate buffer pH 7 containing 20 μM NAD(+)), the biosensor signal was linear up to 10 mM FA, and the detection limit was 18 μM. Relative standard deviations calculated from five consecutive replicates of FA solutions were lower than 5% in the 1-10 mM range. The biosensor was successfully applied to the determination of FA in spiked water samples (tap water and Rhone river water), with recoveries in the 95-110% range. PMID:23907681

  14. Screening of ground water samples for volatile organic compounds using a portable gas chromatograph

    USGS Publications Warehouse

    Buchmiller, R.C.

    1989-01-01

    A portable gas chromatograph was used to screen 32 ground water samples for volatile organic compounds. Seven screened samples were positive; four of the seven samples had volatile organic substances identified by second-column confirmation. Four of the seven positive, screened samples also tested positive in laboratory analyses of duplicate samples. No volatile organic compounds were detected in laboratory analyses of samples that headspace screening indicated to be negative. Samples that contained volatile organic compounds, as identified by laboratory analysis, and that contained a volatile organic compound present in a standard of selected compounds were correctly identified by using the portable gas chromatography. Comparisons of screened-sample data with laboratory data indicate the ability to detect selected volatile organic compounds at concentrations of about 1 microgram per liter in the headspace of water samples by use of a portable gas chromatography. -Author

  15. Change Of Electrical Resistivity Depending On Water Saturation Of The Concrete Samples

    NASA Astrophysics Data System (ADS)

    Sabbaǧ, Nevbahar; Uyanık, Osman

    2016-04-01

    In this study, the changes of electrical apparent resistivity values depending on the water saturation of cubic concrete samples which designed according to different strength were investigated. For this purpose, 3 different concrete design as poor, middle and good strength 150x150x150mm dimensions 9 for each design cubic samples were prepared. After measuring the weight of the prepared samples, in oven were dried at 105 ° C for 24 hours and then the dry weights were measured. Then the samples were placed into the curing pool and saturated weight of the samples were measured in specific time periods during the 90 day take out from the curing pool and the water content were calculated at each stage of these processes. The water content of the samples were obtained during 90 days specific points in time and as well as electrical apparent resistivity method of the different surfaces of the samples the potential difference measurements made by electrical resistivity method and electrical apparent resistivity values of the samples were calculated. Depending on time obtained from this study with respect to time curves of the water content and the apparent resistivity values were constructed. Results showed that the electrical apparent resistivity values increased depends on the water content. This study was supported with OYP05277-DR-14 Project No. by SDU and State Hydraulic Works 13th Regional/2012-01 Project No. Keywords: Concrete, cubic sample, Resistivity, water content, time

  16. Role of immunoassay in the analysis of microcontaminants in water samples

    SciTech Connect

    Aherne, G.W.; English, J.; Marks, V.

    1985-02-01

    Concentrations of natural and synthetic steroids and an anticancer drug (methotrexate) have been determined in water by adapting established immunoassay procedures. The limits of detection for the assays used were 10 ng/liter for norethisterone, 5 ng/liter for ethinyl estradiol and progesterone, and 6.25 ng/liter for methotrexate. Results below the level of detection were obtained in all the samples examined (8 river samples and 6 potable supply samples) except for 2 river samples (17 ng/liter) for norethisterone, and 1 river sample and 1 potable water sample for progesterone (6 ng/liter). A concentration of 1 microgram/liter of methotrexate was found in a sample of hospital effluent. There appears to be no evidence of adverse effects from reused water resources which may be contaminated from the normal use of such highly active therapeutic agents.

  17. A probe for sampling interstitial waters of stream sediments and bog soils

    USGS Publications Warehouse

    Nowlan, G.A.; Carollo, C.

    1974-01-01

    A probe for sampling interstitial waters of stream sediments and bog soils is described. Samples can be obtained within a stratigraphic interval of 2-3 cm, to a depth of 60-80 cm, and with little or no contamination of the samples by sediment or air. ?? 1974.

  18. Occurrence of microbial indicators and Clostridium perfringens in wastewater, water column samples, sediments, drinking water, and Weddell seal feces collected at McMurdo Station, Antarctica

    USGS Publications Warehouse

    Lisle, J.T.; Smith, J.J.; Edwards, D.D.; McFeters, G.A.

    2004-01-01

    McMurdo Station, Antarctica, has discharged untreated sewage into McMurdo Sound for decades. Previous studies delineated the impacted area, which included the drinking water intake, by using total coliform and Clostridium perfringens concentrations. The estimation of risk to humans in contact with the impacted and potable waters may be greater than presumed, as these microbial indicators may not be the most appropriate for this environment. To address these concerns, concentrations of these and additional indicators (fecal coliforms, Escherichia coli, enterococci, coliphage, and enteroviruses) in the untreated wastewater, water column, and sediments of the impacted area and drinking water treatment facility and distribution system at McMurdo Station were determined. Fecal samples from Weddell seals in this area were also collected and analyzed for indicators. All drinking water samples were negative for indicators except for a single total coliform-positive sample. Total coliforms were present in water column samples at higher concentrations than other indicators. Fecal coliform and enterococcus concentrations were similar to each other and greater than those of other indicators in sediment samples closer to the discharge site. C. perfringens concentrations were higher in sediments at greater distances from the discharge site. Seal fecal samples contained concentrations of fecal coliforms, E. coli, enterococci, and C. perfringens similar to those found in untreated sewage. All samples were negative for enteroviruses. A wastewater treatment facility at McMurdo Station has started operation, and these data provide a baseline data set for monitoring the recovery of the impacted area. The contribution of seal feces to indicator concentrations in this area should be considered.

  19. Occurrence of microbial indicators and Clostridium perfringens in wastewater, water column samples, sediments, drinking water, and Weddell seal feces collected at McMurdo Station, Antarctica.

    PubMed

    Lisle, John T; Smith, James J; Edwards, Diane D; McFeters, Gordon A

    2004-12-01

    McMurdo Station, Antarctica, has discharged untreated sewage into McMurdo Sound for decades. Previous studies delineated the impacted area, which included the drinking water intake, by using total coliform and Clostridium perfringens concentrations. The estimation of risk to humans in contact with the impacted and potable waters may be greater than presumed, as these microbial indicators may not be the most appropriate for this environment. To address these concerns, concentrations of these and additional indicators (fecal coliforms, Escherichia coli, enterococci, coliphage, and enteroviruses) in the untreated wastewater, water column, and sediments of the impacted area and drinking water treatment facility and distribution system at McMurdo Station were determined. Fecal samples from Weddell seals in this area were also collected and analyzed for indicators. All drinking water samples were negative for indicators except for a single total coliform-positive sample. Total coliforms were present in water column samples at higher concentrations than other indicators. Fecal coliform and enterococcus concentrations were similar to each other and greater than those of other indicators in sediment samples closer to the discharge site. C. perfringens concentrations were higher in sediments at greater distances from the discharge site. Seal fecal samples contained concentrations of fecal coliforms, E. coli, enterococci, and C. perfringens similar to those found in untreated sewage. All samples were negative for enteroviruses. A wastewater treatment facility at McMurdo Station has started operation, and these data provide a baseline data set for monitoring the recovery of the impacted area. The contribution of seal feces to indicator concentrations in this area should be considered. PMID:15574926

  20. The effects of water sample treatment, preparation, and storage prior to cyanotoxin analysis for cylindrospermopsin, microcystin and saxitoxin.

    PubMed

    Kamp, Lisa; Church, Jennifer L; Carpino, Justin; Faltin-Mara, Erin; Rubio, Fernando

    2016-02-25

    Cyanobacterial harmful algal blooms occur in freshwater lakes, ponds, rivers, and reservoirs, and in brackish waters throughout the world. The wide variety of cyanotoxins and their congeners can lead to frequent exposure of humans through consumption of meat, fish, seafood, blue-green algal products and water, accidental ingestion of contaminated water and cyanobacterial scum during recreational activities, and inhalation of cyanobacterial aerosols. Cyanotoxins can also occur in the drinking water supply. In order to monitor human exposure, sensitive analytical methods such as enzyme linked immunosorbent assay and liquid chromatography-mass spectrometry are often used. Regardless of the analytical method of choice, some problems regularly occur during sample collection, treatment, storage, and preparation which cause toxin loss and therefore underestimation of the true concentration. To evaluate the potential influence of sample treatment, storage and preparation materials on surface and drinking water samples, the effects of different types of materials on toxin recovery were compared. Collection and storage materials included glass and various types of plastics. It was found that microcystin congeners LA and LF adsorbed to polystyrene, polypropylene, high density polyethylene and polycarbonate storage containers, leading to low recoveries (<70%), cylindrospermopsin and saxitoxin did not adsorb to the containers tested. Therefore, this study shows that glass or polyethylene terephthalate glycol containers are the materials of choice for collection and storage of samples containing the cyanotoxins cylindrospermopsin, microcystins, and saxitoxin. This study also demonstrated that after 15 min chlorine decreased the concentration of microcystin LR to <40%, microcystin LA and saxitoxin to <15%, therefore quenching of drinking water samples immediately upon sample collection is critical for accurate analysis. In addition, the effect of various drinking water treatment

  1. Using orthogonal array sampling to cope with uncertainty in ground water problems.

    PubMed

    Baalousha, Husam

    2009-01-01

    Uncertainty in ground water hydrology originates from different sources. Neglecting uncertainty in ground water problems can lead to incorrect results and misleading output. Several approaches have been developed to cope with uncertainty in ground water problems. The most widely used methods in uncertainty analysis are Monte Carlo simulation (MCS) and Latin hypercube sampling (LHS), developed from MCS. Despite the simplicity of MCS, many runs are required to achieve a reliable result. This paper presents orthogonal array (OA) sampling as a means to cope with uncertainty in ground water problems. The method was applied to an analytical stream depletion problem. To examine the convergence rate of the OA sampling, the results were compared to MCS and LHS. This study shows that OA can be applied to ground water problems. Results reveal that the convergence rate of the OA sampling is faster than MCS and LHS, with a smaller error of estimate when applied to a stream depletion problem. PMID:19735309

  2. Measurement of radon concentration in some water samples belonging to some adjoining areas of Pathankot, Punjab

    SciTech Connect

    Kumar, Ajay Sharma, Sumit

    2015-08-28

    The study of radon concentration was measured in some areas of Pathankot district, Punjab, India, from the health hazard point of view due to radon. The exposure to radon through drinking water is largely by inhalation and ingestion. RAD 7, an electronic solid state silicon detector (Durridgeco., USA) was used to measure the radon concentration in drinking water samples of the study area. The recorded values of radon concentration in these water samples are below the recommended limit by UNSCEAR and European commission. The recommended limit of radon concentration in water samples is 4 to 40 Bq/l given by UNSCEAR [1] and European commission has recommended the safe limit for radon concentration in water sample is 100 Bq/l [2].

  3. Predictors of victim disclosure in child sexual abuse: Additional evidence from a sample of incarcerated adult sex offenders.

    PubMed

    Leclerc, Benoit; Wortley, Richard

    2015-05-01

    The under-reporting of child sexual abuse by victims is a serious problem that may prolong the suffering of victims and leave perpetrators free to continue offending. Yet empirical evidence indicates that victim disclosure rates are low. In this study, we perform regression analysis with a sample of 369 adult child sexual offenders to examine potential predictors of victim disclosure. Specifically, we extend the range of previously examined potential predictors of victim disclosure and investigate interaction effects in order to better capture under which circumstances victim disclosure is more likely. The current study differs from previous studies in that it examines the impact of victim and offense variables on victim disclosure from the perspective of the offender. In line with previous studies, we found that disclosure increased with the age of the victim and if penetration had occurred. In addition, we found that disclosure increased when the victim came from a non-dysfunctional family and resisted the abuse. The presence of an interaction effect highlighted the impact of the situation on victim disclosure. This effect indicated that as victims get older, they are more likely to disclose the abuse when they are not living with the offender at the time of abuse, but less likely to do so when they are living with the offender at the time of abuse. These findings are discussed in relation to previous studies and the need to facilitate victim disclosure. PMID:25812798

  4. Water quality monitoring: A comparative case study of municipal and Curtin Sarawak's lake samples

    NASA Astrophysics Data System (ADS)

    Anand Kumar, A.; Jaison, J.; Prabakaran, K.; Nagarajan, R.; Chan, Y. S.

    2016-03-01

    In this study, particle size distribution and zeta potential of the suspended particles in municipal water and lake surface water of Curtin Sarawak's lake were compared and the samples were analysed using dynamic light scattering method. High concentration of suspended particles affects the water quality as well as suppresses the aquatic photosynthetic systems. A new approach has been carried out in the current work to determine the particle size distribution and zeta potential of the suspended particles present in the water samples. The results for the lake samples showed that the particle size ranges from 180nm to 1345nm and the zeta potential values ranges from -8.58 mV to -26.1 mV. High zeta potential value was observed in the surface water samples of Curtin Sarawak's lake compared to the municipal water. The zeta potential values represent that the suspended particles are stable and chances of agglomeration is lower in lake water samples. Moreover, the effects of physico-chemical parameters on zeta potential of the water samples were also discussed.

  5. Photothermal device for water dynamics measurement and thermophysical characterization: Application on textile samples

    NASA Astrophysics Data System (ADS)

    Duvaut, T.; Limare, A.; Bachmann, J. M.

    2002-03-01

    The photopyroelectric method in a noncontact configuration (excitation source: diode laser at 1.94 μm) is capable of yielding information on the water content of a textile sample and on its influence on the thermal properties. A one-dimensional theoretical model was developed assuming the sample thermally homogeneous and taking into account the optical absorption and scattering. The experimental setup designed for this purpose included an excitation source resonant with water absorption, signal and data processing units and cells for conditioning the samples. We optimized the experimental conditions in order to identify the parameters related to the water content in the sample, and to monitor the dynamics of the process. The effective thermal conductivity and the volume specific heat were determined at different moments of time while the sample was taking up water. Two thermal parameters related to the comfort of a fabric were also calculated: the thermal effusivity and the thermal resistance.

  6. Fabric phase sorptive extraction: Two practical sample pretreatment techniques for brominated flame retardants in water.

    PubMed

    Huang, Guiqi; Dong, Sheying; Zhang, Mengfei; Zhang, Haihan; Huang, Tinglin

    2016-09-15

    Sample pretreatment is the critical section for residue monitoring of hazardous pollutants. In this paper, using the cellulose fabric as host matrix, three extraction sorbents such as poly (tetrahydrofuran) (PTHF), poly (ethylene glycol) (PEG) and poly (dimethyldiphenylsiloxane) (PDMDPS), were prepared on the surface of the cellulose fabric. Two practical extraction techniques including stir bar fabric phase sorptive extraction (stir bar-FPSE) and magnetic stir fabric phase sorptive extraction (magnetic stir-FPSE) have been designed, which allow stirring of fabric phase sorbent during the whole extraction process. In the meantime, three brominated flame retardants (BFRs) [tetrabromobisphenol A (TBBPA), tetrabromobisphenol A bisallylether (TBBPA-BAE), tetrabromobisphenol A bis(2,3-dibromopropyl)ether (TBBPA-BDBPE)] in the water sample were selected as model analytes for the practical evaluation of the proposed two techniques using high-performance liquid chromatography (HPLC). Moreover, various experimental conditions affecting extraction process such as the type of fabric phase, extraction time, the amount of salt and elution conditions were also investigated. Due to the large sorbent loading capacity and unique stirring performance, both techniques possessed high extraction capability and fast extraction equilibrium. Under the optimized conditions, high recoveries (90-99%) and low limits of detection (LODs) (0.01-0.05 μg L(-1)) were achieved. In addition, the reproducibility was obtained by evaluating the intraday and interday precisions with relative standard deviations (RSDs) less than 5.1% and 6.8%, respectively. The results indicated that two pretreatment techniques were promising and practical for monitoring of hazardous pollutants in the water sample. Due to low solvent consumption and high repeated use performance, proposed techniques also could meet green analytical criteria. PMID:27300591

  7. Laboratory Investigation into the Contribution of Contaminants to Ground Water from Equipment Materials Used in Sampling

    SciTech Connect

    Gilmore, Tyler J.; Mitroshkov, Alexandre V.; Dresel, P Evan; Sklarew, Debbie S.

    2004-08-30

    Benzene contamination was detected in well water samples from the Ogallala Aquifer beneath and adjacent to the Department of Energy's Pantex Plant near Amarillo, Texas. This study assessed whether or not the materials used in multilevel sampling equipment at this site could have contributed to the contaminants found in well water samples. As part of this investigation, laboratory testing of the sample equipment material was conducted. Results from the laboratory test indicated three different materials from two types of multilevel samplers did, in fact, contribute volatile and semivolatile organic compounds to the ground water samples from static leach tests that were conducted during an eight week period. The nylon-11 tubing contributed trace concentrations of benzene (1.37 ?g/L) and relatively high concentrations of the plasticizer N-butylbenzenesulfonamide (NBSA) (764 mg/L) to the water; a urethane-coated nylon well liner contributed relatively high concentrations of toluene (278 ?g/L) and trace amounts of NBSA; and a sampling port spacer material made of nylon/polypropylene/polyester-composite contributed trace amounts of toluene and NBSA. While the concentrations of benzene and toluene measured in the laboratory tests were below the concentrations measured in actual ground water samples, the concentrations of organics from these equipment materials were sufficient to render the results reported for the ground water samples suspect.

  8. Multiport well design for sampling of ground water at closely spaced vertical intervals

    SciTech Connect

    Delin, G.N.; Landon, M.K.

    1996-11-01

    Detailed vertical sampling is useful in aquifers where vertical mixing is limited and steep vertical gradients in chemical concentrations are expected. Samples can be collected at closely spaced vertical intervals from nested wells with short screened intervals. However, this approach may not be appropriate in all situations. An easy-to-construct and easy-to-install multiport sampling well to collect ground-water samples from closely spaced vertical intervals was developed and tested. The multiport sampling well was designed to sample ground water from surficial sand-and-gravel aquifers. The device consists of multiple stainless-steel tubes within a polyvinyl chloride (PVC) protective casing. The tubes protrude through the wall of the PVC casing at the desired sampling depths. A peristaltic pump is used to collect ground-water samples form the sampling ports. The difference in hydraulic head between any two sampling ports can be measured with a vacuum pump and a modified manometer. The usefulness and versatility of this multiport well design was demonstrated at an agricultural research site near Princeton, Minnesota where sampling ports were installed to a maximum depth of about 12 m below land surface. Trace experiments were conducted using potassium bromide to document the degree to which short-circuiting occurred between sampling ports. Samples were successfully collected for analysis of major cations and anions, nutrients, selected herbicides, isotopes, dissolved gases, and chlorofluorocarbon concentrations.

  9. Multiport well design for sampling of ground water at closely spaced vertical intervals

    USGS Publications Warehouse

    Delin, G.N.; Landon, M.K.

    1996-01-01

    Detailed vertical sampling is useful in aquifers where vertical mixing is limited and steep vertical gradients in chemical concentrations are expected. Samples can be collected at closely spaced vertical intervals from nested wells with short screened intervals. However, this approach may not be appropriate in all situations. An easy-to-construct and easy-to-install multiport sampling well to collect ground-water samples from closely spaced vertical intervals was developed and tested. The multiport sampling well was designed to sample ground water from surficial sand-and-gravel aquifers. The device consists of multiple stainless-steel tubes within a polyvinyl chloride (PVC) protective casing. The tubes protrude through the wall of the PVC casing at the desired sampling depths. A peristaltic pump is used to collect ground-water samples from the sampling ports. The difference in hydraulic head between any two sampling ports can be measured with a vacuum pump and a modified manometer. The usefulness and versatility of this multiport well design was demonstrated at an agricultural research site near Princeton, Minnesota where sampling ports were installed to a maximum depth of about 12 m below land surface. Tracer experiments were conducted using potassium bromide to document the degree to which short-circuiting occurred between sampling ports. Samples were successfully collected for analysis of major cations and anions, nutrients, selected herbicides, isotopes, dissolved gases, and chlorofluorcarbon concentrations.

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

    PubMed Central

    Didugu, Hareesh; Thirtham, Madhavarao; Nelapati, Krishnaiah; Reddy, K Kondal; Kumbhar, Baba Saheb; Poluru, Anusha; Pothanaboyina, Guruvishnu

    2015-01-01

    Aim: The aim of this work was to study the prevalence of Aeromonas spp. and its enterotoxin genes in various water sources. Materials and Methods: 125 samples (50 from well water, 50 from tap water, and 25 from bottled water) were collected from various sources in and around Greater Hyderabad Municipal Corporation and examined for the presence of aeromonads by both cultural and polymerase chain reaction (PCR) assay. Alkaline peptone water with ampicillin was used as enrichment. Aeromonas isolation medium and ampicillin dextrin agar were used as selective media. The boiling and snap chilling method was used for DNA extraction. Primers targeted against 16S rRNA, aer, and ast were used to identify aeromonads and its enterotoxins. Results: 48%, 18%, and 12% of well water, tap water, and bottled water samples were found positive by cultural assay with an overall prevalence of 28.8%. Aeromonads were detected in 32 % (52% in well water, 20% in tap water, and 16% in bottled water) of samples by PCR assay. Aerolysin (aer) gene was noticed in 34.6%, 20%, and 0% of well water, tap water, and bottled water samples, respectively, with an overall prevalence of 27.5%. Thermostable cytotonic enterotoxin (ast) was observed in 37.5% (42.3% in well water, 30% in tap water, and 25% in bottled mineral water) of samples. Conclusions: Presence of aeromonads and its toxin genes in various sources of water is of public health concern and emphasizes the need for necessary preventive measures to tackle the problem. PMID:27047024

  11. Fermentation Quality of Ensiled Water Hyacinth (Eichhornia crassipes) as Affected by Additives

    PubMed Central

    Tham, Ho Thanh; Van Man, Ngo; Pauly, Thomas

    2013-01-01

    A lab-scale ensiling study was carried out to investigate the fermentation quality of water hyacinth (WH) supplemented with molasses, rice bran, as an absorbent, and an inoculant in the form of fermented vegetable juice and their combinations. After wilting the water hyacinths for 7 h to a dry matter (DM) content of 240 to 250 g/kg, the following treatments were applied: i) Control (C), WH only; ii) WH with sugarcane molasses at 40 g/kg WH (CM); iii) WH inoculated with fermented vegetable juice at 10 ml/kg WH (CI); iv) CM and CI (CMI) combined; v) WH with 150 g rice bran/kg WH (CA); vi) CA and CI combined (CAI); vii) CA and CM combined (CAM); and viii) CA, CM and CI combined (CAMI). After application of additives, the differently treated forages were mixed and ensiled in triplicates in 1,500-ml polyethylene jars. After ensiling for 3 d, pH values in all treatments, except C and CI, had decreased to approximately 4.0 and remained low till 14 d. After 56 d, pH had increased between 0.4 to 0.9 pH-units compared to those at 14 d. The ammonia nitrogen (NH3-N) concentration ranged from an acceptable level in treatment CM (8 g/kg N) to a high NH3-N value in treatment CMI (16 g/kg N). Lactic acid formation was higher in CI than in all other treatments. Butyric acid contents, which indicate badly fermented silages, were low in all silages (<2 g/kg DM). There were two-way interactions (p-values from <0.001 to 0.045) for almost all fermentation end-products and pH, except for the molasses×inoculant interaction on NH3-N (p = 0.26). Significant 3-way interactions were found on all observed variables except for weight losses of silages. It is concluded that conserving wilted WH as silage for ruminants may be improved by the addition of molasses or rice bran. PMID:25049776

  12. ADDITIONAL STRESS AND FRACTURE MECHANICS ANALYSES OF PRESSURIZED WATER REACTOR PRESSURE VESSEL NOZZLES

    SciTech Connect

    Walter, Matthew; Yin, Shengjun; Stevens, Gary; Sommerville, Daniel; Palm, Nathan; Heinecke, Carol

    2012-01-01

    In past years, the authors have undertaken various studies of nozzles in both boiling water reactors (BWRs) and pressurized water reactors (PWRs) located in the reactor pressure vessel (RPV) adjacent to the core beltline region. Those studies described stress and fracture mechanics analyses performed to assess various RPV nozzle geometries, which were selected based on their proximity to the core beltline region, i.e., those nozzle configurations that are located close enough to the core region such that they may receive sufficient fluence prior to end-of-life (EOL) to require evaluation of embrittlement as part of the RPV analyses associated with pressure-temperature (P-T) limits. In this paper, additional stress and fracture analyses are summarized that were performed for additional PWR nozzles with the following objectives: To expand the population of PWR nozzle configurations evaluated, which was limited in the previous work to just two nozzles (one inlet and one outlet nozzle). To model and understand differences in stress results obtained for an internal pressure load case using a two-dimensional (2-D) axi-symmetric finite element model (FEM) vs. a three-dimensional (3-D) FEM for these PWR nozzles. In particular, the ovalization (stress concentration) effect of two intersecting cylinders, which is typical of RPV nozzle configurations, was investigated. To investigate the applicability of previously recommended linear elastic fracture mechanics (LEFM) hand solutions for calculating the Mode I stress intensity factor for a postulated nozzle corner crack for pressure loading for these PWR nozzles. These analyses were performed to further expand earlier work completed to support potential revision and refinement of Title 10 to the U.S. Code of Federal Regulations (CFR), Part 50, Appendix G, Fracture Toughness Requirements, and are intended to supplement similar evaluation of nozzles presented at the 2008, 2009, and 2011 Pressure Vessels and Piping (PVP

  13. Estimating an appropriate sampling frequency for monitoring ground water well contamination

    SciTech Connect

    Tuckfield, R.C.

    1994-09-01

    Nearly 1,500 ground water wells at the Savannah River Site (SRS) are sampled quarterly to monitor contamination by radionuclides and other hazardous constituents from nearby waste sites. Some 10,000 water samples were collected in 1993 at a laboratory analysis cost of $10,000,000. No widely accepted statistical method has been developed, to date, for estimating a technically defensible ground water sampling frequency consistent and compliant with federal regulations. Such a method is presented here based on the concept of statistical independence among successively measured contaminant concentrations in time.

  14. Effects of water sample preservation and storage conditions on nitrate concentrations

    SciTech Connect

    Li, Y.C.; Alva, A.K.; Calvert, D.V.; Zhang, M. |

    1995-12-31

    USEPA method 300 requires water samples should be stored at 4 C immediately after collection and NO{sub 3}-N concentration analyzed within 48 hr of sample collection. Many research and commercial laboratories find it is difficult to meet this holding time. Water samples are often stored for several days at 4 C or {minus}20 C until analysis. The objective of this study was to evaluate effects of groundwater sample pretreatment, storage temperatures, and holding times on concentrations of NO{sub 3}-N. The storage of samples at 25 C decreased concentrations of NO{sub 3}-N by 1.7% and 12.5% for 48 hr and 50 days, respectively. No significant changes were observed during the 50 days storage at 4 C or {minus}20 C. Acidification of water samples at 4 C had no significant effect on NO{sub 3}-N concentration up to 50-day holding time.

  15. Errors in Measuring Water Potentials of Small Samples Resulting from Water Adsorption by Thermocouple Psychrometer Chambers 1

    PubMed Central

    Bennett, Jerry M.; Cortes, Peter M.

    1985-01-01

    The adsorption of water by thermocouple psychrometer assemblies is known to cause errors in the determination of water potential. Experiments were conducted to evaluate the effect of sample size and psychrometer chamber volume on measured water potentials of leaf discs, leaf segments, and sodium chloride solutions. Reasonable agreement was found between soybean (Glycine max L. Merr.) leaf water potentials measured on 5-millimeter radius leaf discs and large leaf segments. Results indicated that while errors due to adsorption may be significant when using small volumes of tissue, if sufficient tissue is used the errors are negligible. Because of the relationship between water potential and volume in plant tissue, the errors due to adsorption were larger with turgid tissue. Large psychrometers which were sealed into the sample chamber with latex tubing appeared to adsorb more water than those sealed with flexible plastic tubing. Estimates are provided of the amounts of water adsorbed by two different psychrometer assemblies and the amount of tissue sufficient for accurate measurements of leaf water potential with these assemblies. It is also demonstrated that water adsorption problems may have generated low water potential values which in prior studies have been attributed to large cut surface area to volume ratios. PMID:16664367

  16. A Novel Lipase as Aquafeed Additive for Warm-Water Aquaculture

    PubMed Central

    Yang, Yalin; Huang, Lu; Zhou, Zhigang

    2015-01-01

    A novel Acinetobacter lipase gene lipG1was cloned from DNA extracted from intestinal sample of common carp (Cyprinus carpio), and expressed in E. coli BL21. The encoded protein was 406 amino acids in length. Phylogenetic analysis indicated that LipG1 and its relatives comprised a novel group of true lipases produced by Gram-negative bacteria. LipG1 showed maximal activity at 40℃ and pH 8.0 when pNP decanoate (C10) was used as the substrate, and remained high activity between 20℃ and 35℃. Activity of the lipase was promoted by Ca2+ and Mg2+, and inhibited by Zn2+ and Cu2+. Moreover, LipG1 is stable with proteases, most commercial detergents and organic solvents. Substrate specificity test indicated that LipG1can hydrolyse pNP esters with acyl chain length from C2 to C16, with preference for medium-chain pNP esters (C8, C10). Lastly, LipG1was evaluated as an aquafeed additive for juvenile common carp (Cyprinus carpio). Results showed that supplementation of LipG1significantly improved the gut and heptaopancreas lipase activity of fish fed with palm oil diet. Consistently, improved feed conversion ratio and growth performance were recorded in the LipG1 feeding group, to levels comparable to the group of fish fed with soybean oil diet. Collectively, LipG1 exhibited good potential as an aquafeed additive enzyme, and deserves further characterization as the representative of a novel group of lipases. PMID:26147311

  17. Detection of Acanthamoeba and Toxoplasma in River Water Samples by Molecular Methods in Iran

    PubMed Central

    MAHMOUDI, Mohammad Reza; KAZEMI, Bahram; HAGHIGHI, Ali; KARANIS, Panagiotis

    2015-01-01

    Background: Free-living amoebae such as Acanthamoeba species may act as carriers of Cryptosporidium and Toxoplasma oocysts, thus, may play an important role in the water-borne transmission of these parasites. In the present study, a loop mediated isothermal amplification (LAMP) method for detection of Toxoplasma and a PCR assay were developed for investigation of Acanthamoeba in environmental water samples. Methods: A total of 34 samples were collected from the surface water in Guilan Province. Water samples were filtrated with membrane filters and followed by DNA extraction. PCR and LAMP methods used for detection of the protozoan parasites Acanthamoeba and Toxoplasma respectively. Results: Totally 30 and 2 of 34 samples were positive for Acanthamoeba and Toxoplasma oocysts respectively. Two samples were positive for both investigated parasites. Conclusion: The investigated water supplies, are contaminated by Toxoplasma and Acanthamoeba (oo)cystes. Acanthamoeba may play an important role in water-borne transmission of Toxoplasma in the study area. For the first time in Iran, protocol of LAMP method was used effectively for the detection of Toxoplasma in surface water samples in Iran. PMID:26246823

  18. Soy Protein Isolate As Fluid Loss Additive in Bentonite-Water-Based Drilling Fluids.

    PubMed

    Li, Mei-Chun; Wu, Qinglin; Song, Kunlin; Lee, Sunyoung; Jin, Chunde; Ren, Suxia; Lei, Tingzhou

    2015-11-11

    Wellbore instability and formation collapse caused by lost circulation are vital issues during well excavation in the oil industry. This study reports the novel utilization of soy protein isolate (SPI) as fluid loss additive in bentonite-water based drilling fluids (BT-WDFs) and describes how its particle size and concentration influence on the filtration property of SPI/BT-WDFs. It was found that high pressure homogenization (HPH)-treated SPI had superior filtration property over that of native SPI due to the improved ability for the plugging pore throat. HPH treatment also caused a significant change in the surface characteristic of SPI, leading to a considerable surface interaction with BT in aqueous solution. The concentration of SPI had a significant impact on the dispersion state of SPI/BT mixtures in aquesous solution. At low SPI concentrations, strong aggregations were created, resulting in the formation of thick, loose, high-porosity and high-permeability filter cakes and high fluid loss. At high SPI concentrations, intercatlated/exfoliated structures were generated, resulting in the formation of thin, compact, low-porosity and low-permeability filter cakes and low fluid loss. The SPI/BT-WDFs exhibited superior filtration property than pure BT-WDFs at the same solid concentraion, demonstrating the potential utilization of SPI as an effective, renewable, and biodegradable fluid loss reducer in well excavation applications. PMID:26492498

  19. Genotypic Characterization of Cryptosporidium hominis from Water Samples in São Paulo, Brazil

    PubMed Central

    Araújo, Ronalda S.; Dropa, Milena; Fernandes, Licia N.; Carvalho, Terezinha T.; Sato, Maria Inês Z.; Soares, Rodrigo M.; Matté, Glavur R.; Matté, Maria Helena

    2011-01-01

    The protozoan parasite Cryptosporidium has emerged as one of the most important water contaminants, causing waterborne outbreaks of diarrheal diseases worldwide. The small size of oocysts under the microscope and the possibility of changes in characteristics of oocysts, mainly in environmental samples, make the taxonomy of the genus difficult if morphologic characteristics are considered. This limitation encouraged the application of molecular methods to identify this microorganism. The aim of this study was to detect and identify by nested-polymerase chain reaction oocysts of Cryptosporidium present in water samples in the state of São Paulo, Brazil. Water samples were concentrated through a membrane filter, DNA was extracted by using a standard technique, and both amplification reactions used forward and reverse oligonucleotides that were complementary to Cryptosporidium 18S ribosomal RNA gene sequences. Thirty water samples from different sites of collection in the state of São Paulo were evaluated. Cryptosporidium oocysts were detected in 30% of the samples. By genoptyping, C. hominis and Cryptosporidium sp. were identified in recreational water and C. meleagridis was identified in surface water samples. This is the first report of C. hominis in environmental samples in Brazil. Although identification of Cryptosporidium is still a difficult task, molecular methods are essential for specific identification and are a helpful tool to aid to understand the epidemiology of this parasite in Brazil. PMID:22049036

  20. Methods for collecting algal samples as part of the National Water-Quality Assessment Program

    USGS Publications Warehouse

    Porter, Stephen D.; Cuffney, Thomas F.; Gurtz, Martin E.; Meador, Michael R.

    1993-01-01

    Benthic algae (periphyton) and phytoplankton communities are characterized in the U.S. Geological Survey's National Water-Quality Assessment Program as part of an integrated physical, chemical, and biological assessment of the Nation's water quality. This multidisciplinary approach provides multiple lines of evidence for evaluating water-quality status and trends, and for refining an understanding of the factors that affect water-quality conditions locally, regionally, and nationally. Water quality can be characterized by evaluating the results of qualitative and quantitative measurements of the algal community. Qualitative periphyton samples are collected to develop of list of taxa present in the sampling reach. Quantitative periphyton samples are collected to measure algal community structure within selected habitats. These samples of benthic algal communities are collected from natural substrates, using the sampling methods that are most appropriate for the habitat conditions. Phytoplankton samples may be collected in large nonwadeable streams and rivers to meet specific program objectives. Estimates of algal biomass (chlorophyll content and ash-free dry mass) also are optional measures that may be useful for interpreting water-quality conditions. A nationally consistent approach provides guidance on site, reach, and habitat selection, as well as information on methods and equipment for qualitative and quantitative sampling. Appropriate quality-assurance and quality-control guidelines are used to maximize the ability to analyze data locally, regionally, and nationally.

  1. Understanding the origin and evolution of water in the Moon through lunar sample studies

    PubMed Central

    Anand, Mahesh; Tartèse, Romain; Barnes, Jessica J.

    2014-01-01

    A paradigm shift has recently occurred in our knowledge and understanding of water in the lunar interior. This has transpired principally through continued analysis of returned lunar samples using modern analytical instrumentation. While these recent studies have undoubtedly measured indigenous water in lunar samples they have also highlighted our current limitations and some future challenges that need to be overcome in order to fully understand the origin, distribution and evolution of water in the lunar interior. Another exciting recent development in the field of lunar science has been the unambiguous detection of water or water ice on the surface of the Moon through instruments flown on a number of orbiting spacecraft missions. Considered together, sample-based studies and those from orbit strongly suggest that the Moon is not an anhydrous planetary body, as previously believed. New observations and measurements support the possibility of a wet lunar interior and the presence of distinct reservoirs of water on the lunar surface. Furthermore, an approach combining measurements of water abundance in lunar samples and its hydrogen isotopic composition has proved to be of vital importance to fingerprint and elucidate processes and source(s) involved in giving rise to the lunar water inventory. A number of sources are likely to have contributed to the water inventory of the Moon ranging from primordial water to meteorite-derived water ice through to the water formed during the reaction of solar wind hydrogen with the lunar soil. Perhaps two of the most striking findings from these recent studies are the revelation that at least some portions of the lunar interior are as water-rich as some Mid-Ocean Ridge Basalt source regions on Earth and that the water in the Earth and the Moon probably share a common origin. PMID:25114308

  2. Understanding the origin and evolution of water in the Moon through lunar sample studies.

    PubMed

    Anand, Mahesh; Tartèse, Romain; Barnes, Jessica J

    2014-09-13

    A paradigm shift has recently occurred in our knowledge and understanding of water in the lunar interior. This has transpired principally through continued analysis of returned lunar samples using modern analytical instrumentation. While these recent studies have undoubtedly measured indigenous water in lunar samples they have also highlighted our current limitations and some future challenges that need to be overcome in order to fully understand the origin, distribution and evolution of water in the lunar interior. Another exciting recent development in the field of lunar science has been the unambiguous detection of water or water ice on the surface of the Moon through instruments flown on a number of orbiting spacecraft missions. Considered together, sample-based studies and those from orbit strongly suggest that the Moon is not an anhydrous planetary body, as previously believed. New observations and measurements support the possibility of a wet lunar interior and the presence of distinct reservoirs of water on the lunar surface. Furthermore, an approach combining measurements of water abundance in lunar samples and its hydrogen isotopic composition has proved to be of vital importance to fingerprint and elucidate processes and source(s) involved in giving rise to the lunar water inventory. A number of sources are likely to have contributed to the water inventory of the Moon ranging from primordial water to meteorite-derived water ice through to the water formed during the reaction of solar wind hydrogen with the lunar soil. Perhaps two of the most striking findings from these recent studies are the revelation that at least some portions of the lunar interior are as water-rich as some Mid-Ocean Ridge Basalt source regions on Earth and that the water in the Earth and the Moon probably share a common origin. PMID:25114308

  3. Ground-Water Data-Collection Protocols and Procedures for the National Water-Quality Assessment Program: Collection and Documentation of Water-Quality Samples and Related Data

    USGS Publications Warehouse

    Koterba, Michael T.; Wilde, Franceska D.; Lapham, Wayne W.

    1995-01-01

    Protocols for ground-water sampling are described in a report written in 1989 as part of the pilot program for the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS). These protocols have been reviewed and revised to address the needs of the full-scale implementation of the NAWQA Program that began in 1991. This report, which is a collaborative effort between the NAWQA Program and the USGS Office of Water Quality, is the result of that review and revision. This report describes protocols and recommended procedures for the collection of water-quality samples and related data from wells for the NAWQA Program. Protocols and recommended procedures discussed include (1) equipment setup and other preparations for data collection; (2) well purging and field measurements; (3) collecting and processing ground-water-quality samples; (4) equipment decontamination; (5) quality-control sampling; and (6) sample handling and shipping.

  4. Analysis of water-quality data and sampling programs at selected sites in north-central Colorado. Water Resources Investigation

    SciTech Connect

    Mueller, D.K.

    1990-01-01

    The report provides an analysis of the water-quality data at selected sites and provides an evaluation of the suitability of the current (1987) sampling programs at each site for meeting future needs of defining water quality within the area affected by CBT Project operations. Specific objectives of the report are to: provide summary statistics of water-quality data at each site for the period of record; identify significant trends for water-quality constituents or properties at each site; determine whether certain stations could be discontinued without substantial loss of information; determine whether the frequency of sampling for any individual constituent or groups of constituents at any of the sites could be decreased without substantial loss of information; and evaluate which water-quality constituents and properties need to be measured in order to meet the water-quality-data needs at each site. Fourteen streamflow and reservoir stations were selected for the analysis. These sites represent a network of water-quality sampling stations that can be used to evaluate the effects of CBT Project water transfers on both sides of the Continental Divide.

  5. High frequency sampling of stable water isotopes for assessing runoff generation processes in a mesoscale urbanized catchment

    NASA Astrophysics Data System (ADS)

    Wrede, Sebastian; Fenicia, Fabrizio; Kurtenbach, Andreas; Keßler, Sabine; Bierl, Reinhard

    2013-04-01

    Experimental hydrology critically relies on tracer techniques to decipher and uncover runoff generation processes. Although tracer measurements contributed significantly to a better understanding of catchment functioning, their potential is not yet fully exploited. The temporal resolution of tracer measurements is typically relatively coarse, and applications are confined to a few locations. Additionally, experimental hydrology has focused primarily on pristine catchments, and the influence of anthropogenic effects remains largely unexplored. High frequency sampling of multiple tracers may therefore substantially enhance our understanding of hydrological processes and the impact of anthropogenic effects and enable a better protection and management of water resources and water quality. In this preliminary study we aim to assess runoff generation processes using geochemical and isotopic tracer techniques in the mesoscale Olewiger Bach catchment (24 km²) that is located in the low mountain ranges of the city of Trier, southwest Germany. The catchment is mainly characterized by quartzite and Devonian schist, overlain by fluvial sediments. Mixed land use prevails in the southern part of the basin, while the northern lower reaches are mainly urbanized. Several waste water treatment plants, separate sewer and stormwater management systems are present in parts of the catchment and contribute to the discharge of the main river. Tracer techniques employed in this ongoing study are twofold. A long term sampling of stable water isotopes (oxygen-18 and deuterium) was initiated in order to allow inferences about mean residence times of water in different catchment compartments, while event-based sampling using a multi-tracer approach was used to identify different runoff components and associated water pathways. Special attention is given to the observation of in-channel processes by assessing the dynamics of dissolved and particulate geochemical tracers and stable water

  6. Preparations and properties of anti-corrosion additives of water-soluble metal working fluids for aluminum alloy materials.

    PubMed

    Watanabe, Shoji

    2008-01-01

    This short review describes various types of anti-corrosion additives of water-soluble metal working fluids for aluminum alloy materials. It is concerned with synthetic additives classified according to their functional groups; silicone compounds, carboxylic acids and dibasic acids, esters, Diels-Alder adducts, various polymers, nitrogen compounds, phosphoric esters, phosphonic acids, and others. Testing methods for water-soluble metal working fluids for aluminum alloy materials are described for a practical application in a laboratory. PMID:18075217

  7. “Nanofiltration” Enabled by Super-Absorbent Polymer Beads for Concentrating Microorganisms in Water Samples

    PubMed Central

    Xie, Xing; Bahnemann, Janina; Wang, Siwen; Yang, Yang; Hoffmann, Michael R.

    2016-01-01

    Detection and quantification of pathogens in water is critical for the protection of human health and for drinking water safety and security. When the pathogen concentrations are low, large sample volumes (several liters) are needed to achieve reliable quantitative results. However, most microbial identification methods utilize relatively small sample volumes. As a consequence, a concentration step is often required to detect pathogens in natural waters. Herein, we introduce a novel water sample concentration method based on superabsorbent polymer (SAP) beads. When SAP beads swell with water, small molecules can be sorbed within the beads, but larger particles are excluded and, thus, concentrated in the residual non-sorbed water. To illustrate this approach, millimeter-sized poly(acrylamide-co-itaconic acid) (P(AM-co-IA)) beads are synthesized and successfully applied to concentrate water samples containing two model microorganisms: Escherichia coli and bacteriophage MS2. Experimental results indicate that the size of the water channel within water swollen P(AM-co-IA) hydrogel beads is on the order of several nanometers. The millimeter size coupled with a negative surface charge of the beads are shown to be critical in order to achieve high levels of concentration. This new concentration procedure is very fast, effective, scalable, and low-cost with no need for complex instrumentation. PMID:26876979

  8. "Nanofiltration" Enabled by Super-Absorbent Polymer Beads for Concentrating Microorganisms in Water Samples.

    PubMed

    Xie, Xing; Bahnemann, Janina; Wang, Siwen; Yang, Yang; Hoffmann, Michael R

    2016-01-01

    Detection and quantification of pathogens in water is critical for the protection of human health and for drinking water safety and security. When the pathogen concentrations are low, large sample volumes (several liters) are needed to achieve reliable quantitative results. However, most microbial identification methods utilize relatively small sample volumes. As a consequence, a concentration step is often required to detect pathogens in natural waters. Herein, we introduce a novel water sample concentration method based on superabsorbent polymer (SAP) beads. When SAP beads swell with water, small molecules can be sorbed within the beads, but larger particles are excluded and, thus, concentrated in the residual non-sorbed water. To illustrate this approach, millimeter-sized poly(acrylamide-co-itaconic acid) (P(AM-co-IA)) beads are synthesized and successfully applied to concentrate water samples containing two model microorganisms: Escherichia coli and bacteriophage MS2. Experimental results indicate that the size of the water channel within water swollen P(AM-co-IA) hydrogel beads is on the order of several nanometers. The millimeter size coupled with a negative surface charge of the beads are shown to be critical in order to achieve high levels of concentration. This new concentration procedure is very fast, effective, scalable, and low-cost with no need for complex instrumentation. PMID:26876979

  9. “Nanofiltration” Enabled by Super-Absorbent Polymer Beads for Concentrating Microorganisms in Water Samples

    NASA Astrophysics Data System (ADS)

    Xie, Xing; Bahnemann, Janina; Wang, Siwen; Yang, Yang; Hoffmann, Michael R.

    2016-02-01

    Detection and quantification of pathogens in water is critical for the protection of human health and for drinking water safety and security. When the pathogen concentrations are low, large sample volumes (several liters) are needed to achieve reliable quantitative results. However, most microbial identification methods utilize relatively small sample volumes. As a consequence, a concentration step is often required to detect pathogens in natural waters. Herein, we introduce a novel water sample concentration method based on superabsorbent polymer (SAP) beads. When SAP beads swell with water, small molecules can be sorbed within the beads, but larger particles are excluded and, thus, concentrated in the residual non-sorbed water. To illustrate this approach, millimeter-sized poly(acrylamide-co-itaconic acid) (P(AM-co-IA)) beads are synthesized and successfully applied to concentrate water samples containing two model microorganisms: Escherichia coli and bacteriophage MS2. Experimental results indicate that the size of the water channel within water swollen P(AM-co-IA) hydrogel beads is on the order of several nanometers. The millimeter size coupled with a negative surface charge of the beads are shown to be critical in order to achieve high levels of concentration. This new concentration procedure is very fast, effective, scalable, and low-cost with no need for complex instrumentation.

  10. 78 FR 35929 - Proposed Listing of Additional Waters To Be Included on Indiana's 2010 List of Impaired Waters...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-14

    ... decision identifying water quality limited segments and associated pollutants in Indiana to be listed... pollution controls are not stringent enough to attain or maintain state water quality standards and for... certain water quality limited segments and associated pollutants (Table 1 in Appendix A1 of EPA's...

  11. 78 FR 56695 - Proposed Listing of Additional Waters To Be Included on Indiana's 2010 List of Impaired Waters...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-13

    ... EPA's proposed decision identifying water quality limited segments and associated pollutants in Indiana to be listed pursuant to the Clean Water Act Section 303(d)(2), and requests public comment. For... Under the Clean Water Act AGENCY: Environmental Protection Agency (EPA). ACTION: Reopening of...

  12. GROUND WATER ISSUE: LOW-FLOW (MINIMAL DRAWDOWN) GROUND-WATER SAMPLING PROCEDURES

    EPA Science Inventory

    This paper is intended to provide background information on the development of low-flow sampling procedures and its application under a variety of hydrogeologic settings. The sampling methodology described in this paper assumes that the monitoring goal is to sample monitoring wel...

  13. THE COMBINED CARCINOGENIC RISK FOR EXPOSURE TO MIXTURES OF DRINKING WATER DISINFECTION BY-PRODUCTS MAY BE LESS THAN ADDITIVE

    EPA Science Inventory

    The Combined Carcinogenic Risk for Exposure to Mixtures of Drinking Water Disinfection By-Products May be Less Than Additive

    Risk assessment methods for chemical mixtures in drinking water are not well defined. Current default risk assessments for chemical mixtures assume...

  14. Vacuum hand pump apparatus for collecting water samples from a horizontal intragravel pipe

    USGS Publications Warehouse

    Saiki, Michael K.; Martin, Barbara A.

    1996-01-01

    We describe a lightweight, portable vacuum hand pump apparatus for use in collecting water samples from horizontal intragravel pipe samplers buried in the stream bottom. The apparatus is easily fabricated from relatively inexpensive materials available at many laboratory supply houses.

  15. Instrumental neutron activation analysis data for cloud-water particulate samples, Mount Bamboo, Taiwan

    USGS Publications Warehouse

    Lin, Neng-Huei; Sheu, Guey-Rong; Wetherbee, Gregory A.; Debey, Timothy M.

    2013-01-01

    Cloud water was sampled on Mount Bamboo in northern Taiwan during March 22-24, 2002. Cloud-water samples were filtered using 0.45-micron filters to remove particulate material from the water samples. Filtered particulates were analyzed by instrumental neutron activation analysis (INAA) at the U.S. Geological Survey National Reactor Facility in Denver, Colorado, in February 2012. INAA elemental composition data for the particulate materials are presented. These data complement analyses of the aqueous portion of the cloud-water samples, which were performed earlier by the Department of Atmospheric Sciences, National Central University, Taiwan. The data are intended for evaluation of atmospheric transport processes and air-pollution sources in Southeast Asia.

  16. Monitoring-well network and sampling design for ground-water quality, Wind River Indian Reservation, Wyoming

    USGS Publications Warehouse

    Mason, Jon P.; Sebree, Sonja K.; Quinn, Thomas L.

    2005-01-01

    The Wind River Indian Reservation, located in parts of Fremont and Hot Springs Counties, Wyoming, has a total land area of more than 3,500 square miles. Ground water on the Wind River Indian Reservation is a valuable resource for Shoshone and Northern Arapahoe tribal members and others who live on the Reservation. There are many types of land uses on the Reservation that have the potential to affect the quality of ground-water resources. Urban areas, rural housing developments, agricultural lands, landfills, oil and natural gas fields, mining, and pipeline utility corridors all have the potential to affect ground-water quality. A cooperative study was developed between the U.S. Geological Survey and the Wind River Environmental Quality Commission to identify areas of the Reservation that have the highest potential for ground-water contamination and develop a comprehensive plan to monitor these areas. An arithmetic overlay model for the Wind River Indian Reservation was created using seven geographic information system data layers representing factors with varying potential to affect ground-water quality. The data layers used were: the National Land Cover Dataset, water well density, aquifer sensitivity, oil and natural gas fields and petroleum pipelines, sites with potential contaminant sources, sites that are known to have ground-water contamination, and National Pollutant Discharge Elimination System sites. A prioritization map for monitoring ground-water quality on the Reservation was created using the model. The prioritization map ranks the priority for monitoring ground-water quality in different areas of the Reservation as low, medium, or high. To help minimize bias in selecting sites for a monitoring well network, an automated stratified random site-selection approach was used to select 30 sites for ground-water quality monitoring within the high priority areas. In addition, the study also provided a sampling design for constituents to be monitored, sampling

  17. UMTRA project water sampling and analysis plan, Naturita, Colorado. Revision 1

    SciTech Connect

    1995-09-01

    Planned, routine ground water sampling activities for calendar year 1995 to 1997 at the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project site near Naturita, Colorado, are described in this water sampling and analysis plan. The following plan identifies and justifies the sampling locations, analytical parameters, detection limits, sampling frequency, and specific rationale for each routine monitoring station at the site. The regulatory basis for routine ground water monitoring at UMTRA Project sites is derived from the US Environmental Protection Agency (EPA) regulations in 40 CFR Part 192. Sampling procedures are guided by the UMTRA Project standard operating procedures (SOP) (JEG, n.d.), the Technical Approach Document (TAD) (DOE, 1989), and the most effective technical approach for the site.

  18. Alteration of an annealed and irradiated lunar fines sample by adsorbed water

    NASA Technical Reports Server (NTRS)

    Holmes, H. F.; Agron, P. A.; Eichler, E.; Fuller, E. L., Jr.; Okelley, G. D.; Gammage, R. B.

    1975-01-01

    Apollo 12 lunar fines sample 12070,403 was annealed at 1000 C and subsequently irradiated with a beam of 130 MeV Fe(9+) ions. Adsorptions of nitrogen and water were measured before and after the irradiation. Prior to the irradiation, the fines were nonporous and water had no effect on the physical characteristics of the lunar fines. In contrast, after the irradiation, the interaction with water caused an increase in the specific surface area and created a pore system. These results are definitive evidence that the interaction of water with damage tracks is the prime factor involved in the alteration of lunar fines by adsorbed water.

  19. Geophysical methods to support correct water sampling locations for salt dilution gauging

    NASA Astrophysics Data System (ADS)

    Comina, C.; Lasagna, M.; De Luca, D. A.; Sambuelli, L.

    2014-05-01

    To improve water management design, particularly in irrigation areas, it is important to evaluate the baseline state of the water resources, including canal discharge. Discharge measurements, using salt dilution gauging, are a traditional and well-documented technique. The complete mixing of salt used for dilution gauging is required for reliable measurements; this condition is difficult to test or verify and, if not fulfilled, is the largest source of uncertainty in the discharge calculation. In this paper, a geophysical technique (FERT, Fast Electrical Resistivity Tomography) is proposed for imaging the distribution of the salt plume used for dilution gauging at every point along a sampling cross-section. In this way, it is possible to check whether complete mixing has occurred. If the mixing is not complete, the image created by FERT can also provide guidance for selecting water-sampling locations in the sampling cross-section. A water multi-sampling system prototype for the simultaneous sampling of canal water at different points within the cross-section, aimed to potentially take into account concentration variability, is also proposed and tested. Preliminary results of a single test with salt dilution gauging and FERT in a real case are reported. The results show that imaging the passage of the salt plume is possible by means of geophysical controls and that this can potentially help in the selection of water sampling points.

  20. THE CARCINOGENIC RESPONSE TO A MIXTURE OF DRINKING WATER DISINFECTION BY-PRODUCTS (DBP) WAS LESS THAN ADDITIVE

    EPA Science Inventory

    THE CARCINOGENIC RESPONSE TO A MIXTURE OF DRINKING WATER DISINFECTION BY -PRODUCTS (DBP) W AS LESS THAN ADDITIVE.

    Current default risk assessments for chemical mixtures assume additivity of carcinogenic effects but this may under or over represent the actual biological res...

  1. Comparison of water-quality samples collected by siphon samplers and automatic samplers in Wisconsin

    USGS Publications Warehouse

    Graczyk, David J.; Robertson, Dale M.; Rose, William J.; Steur, Jeffrey J.

    2000-01-01

    In small streams, flow and water-quality concentrations often change quickly in response to meteorological events. Hydrologists, field technicians, or locally hired stream ob- servers involved in water-data collection are often unable to reach streams quickly enough to observe or measure these rapid changes. Therefore, in hydrologic studies designed to describe changes in water quality, a combination of manual and automated sampling methods have commonly been used manual methods when flow is relatively stable and automated methods when flow is rapidly changing. Auto- mated sampling, which makes use of equipment programmed to collect samples in response to changes in stage and flow of a stream, has been shown to be an effective method of sampling to describe the rapid changes in water quality (Graczyk and others, 1993). Because of the high cost of automated sampling, however, especially for studies examining a large number of sites, alternative methods have been considered for collecting samples during rapidly changing stream conditions. One such method employs the siphon sampler (fig. 1). also referred to as the "single-stage sampler." Siphon samplers are inexpensive to build (about $25- $50 per sampler), operate, and maintain, so they are cost effective to use at a large number of sites. Their ability to collect samples representing the average quality of water passing though the entire cross section of a stream, however, has not been fully demonstrated for many types of stream sites.

  2. Soil and Water – What is Detectable through Microbiological Sample Preparation Techniques

    EPA Science Inventory

    The concerns of a potential terrorist’s use of biological agents in soil and ground water are articulated by comparisons to major illnesses in this Country involving contaminated drinking water sources. Objectives are focused on the importance of sample preparation in the rapid, ...

  3. 40 CFR 257.23 - Ground-water sampling and analysis requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... mean and the background mean levels for each constituent. (2) An analysis of variance (ANOVA) based on... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Ground-water sampling and analysis... and analysis requirements. (a) The ground-water monitoring program must include consistent...

  4. 40 CFR 257.23 - Ground-water sampling and analysis requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... mean and the background mean levels for each constituent. (2) An analysis of variance (ANOVA) based on... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Ground-water sampling and analysis... and analysis requirements. (a) The ground-water monitoring program must include consistent...

  5. Water soluble graphene as electrolyte additive in magnesium-air battery system

    NASA Astrophysics Data System (ADS)

    Mayilvel Dinesh, M.; Saminathan, K.; Selvam, M.; Srither, S. R.; Rajendran, V.; Kaler, Karan V. I. S.

    2015-02-01

    Magnesium-air (Mg-air) batteries are an important energy source used to power electronic equipment and automobiles. Metal-air batteries give more energy density due to surplus air involved in reduction reaction at air cathode. In this study, the scope of improvements in the efficiency of Metal-air batteries is investigated through addition of water soluble graphene (WSG) as inhibitor in NaCl electrolyte. The discharge performance, corrosion behaviour and electrochemical impedance are studied for (i) the conventional Mg-air battery using 3.5% NaCl and (ii) Mg-air battery with WSG-based 3.5% NaCl electrolyte. X-ray diffraction analysis for WSG is carried out and it shows the crystalline nature of WSG by an intense sharp peak at 26.3°. Scanning electron microscope study is also performed and shows the flake-like structure of WSG denoted by thin layers of carbon. The immersion of WSG in 3.5% NaCl electrolyte increased the current density from 13.24 to 19.33 mA cm-2. Meanwhile, the WSG-based Mg-air battery was found to hold specific discharge capacity of 1030.71 mAh g-1, which was higher than that obtained in 3.5% NaCl electrolyte (i.e., 822.85 mAh g-1). The WSG-based Mg-air battery shows good self-discharge capacity and higher electrochemical activity during discharge.

  6. Water soluble graphene as electrolyte additive in magnesium-air battery system

    NASA Astrophysics Data System (ADS)

    Saminathan, K.; Mayilvel Dinesh, M.; Selvam, M.; Srither, S. R.; Rajendran, V.; Kaler, Karan V. I. S.

    2015-02-01

    Magnesium-air (Mg-air) batteries are an important energy source used to power electronic equipment and automobiles. Metal-air batteries give more energy density due to surplus air involved in reduction reaction at air cathode. In this study, the scope of improvements in the efficiency of Metal-air batteries is investigated through addition of water soluble graphene (WSG) as inhibitor in NaCl electrolyte. The discharge performance, corrosion behaviour and electrochemical impedance are studied for (i) the conventional Mg-air battery using 3.5% NaCl and (ii) Mg-air battery with WSG-based 3.5% NaCl electrolyte. X-ray diffraction analysis for WSG is carried out and it shows the crystalline nature of WSG by an intense sharp peak at 26.3°. Scanning electron microscope study is also performed and shows the flake-like structure of WSG denoted by thin layers of carbon. The immersion of WSG in 3.5% NaCl electrolyte increased the current density from 13.24 to 19.33 mA cm-2. Meanwhile, the WSG-based Mg-air battery was found to hold specific discharge capacity of 1030.71 mAh g-1, which was higher than that obtained in 3.5% NaCl electrolyte (i.e., 822.85 mAh g-1). The WSG-based Mg-air battery shows good self-discharge capacity and higher electrochemical activity during discharge.

  7. A solid phase extraction-ion chromatography with conductivity detection procedure for determining cationic surfactants in surface water samples.

    PubMed

    Olkowska, Ewa; Polkowska, Żaneta; Namieśnik, Jacek

    2013-11-15

    A new analytical procedure for the simultaneous determination of individual cationic surfactants (alkyl benzyl dimethyl ammonium chlorides) in surface water samples has been developed. We describe this methodology for the first time: it involves the application of solid phase extraction (SPE-for sample preparation) coupled with ion chromatography-conductivity detection (IC-CD-for the final determination). Mean recoveries of analytes between 79% and 93%, and overall method quantification limits in the range from 0.0018 to 0.038 μg/mL for surface water and CRM samples were achieved. The methodology was applied to the determination of individual alkyl benzyl quaternary ammonium compounds in environmental samples (reservoir water) and enables their presence in such types of waters to be confirmed. In addition, it is a simpler, less time-consuming, labour-intensive, avoiding use of toxic chloroform and significantly less expensive methodology than previously described approaches (liquid-liquid extraction coupled with liquid chromatography-mass spectrometry). PMID:24148395

  8. Energy and water additions give rise to simple responses in plant canopy and soil microclimates of a high arctic ecosystem

    NASA Astrophysics Data System (ADS)

    Sullivan, Patrick F.; Welker, Jeffrey M.; Steltzer, Heidi; Sletten, Ronald S.; Hagedorn, Birgit; Arens, Seth J. T.; Horwath, Jennifer L.

    2008-09-01

    Energy and water inputs were increased during the snow-free season to test the sensitivity of a cold, dry ecosystem to climate change. Infrared radiators were used to provide two levels of supplemental radiation (T1 and T2) to prostrate dwarf-shrub, herb tundra in northwest Greenland. The higher radiation addition was combined with supplemental water in a factorial design. Radiation additions increased midday canopy temperatures by up to 4.0°C and 6.0°C and growing season mean shallow soil temperatures by 1.3°C and 2.4°C in T1 and T2 plots, respectively. Soil warming was measured at and probably exceeded 10 cm in depth. There was no evidence of soil drying in plots that received additional radiation, in contrast with other studies, nor was there evidence that supplemental water interacted with radiation additions to affect soil temperatures. Water additions were generally undetectable against a background of large seasonal changes in soil water content. We suggest that well-drained soils and strong seasonal controls on soil water contents (e.g., soil thaw and evapotranspiration) limit the system's sensitivity to changes in precipitation during the brief growing season. In general, multifactor changes in climate gave rise to simple changes in the vegetation microclimate of this cold, dry ecosystem.

  9. Iodine speciation in coastal and inland bathing waters and seaweeds extracts using a sequential injection standard addition flow-batch method.

    PubMed

    Santos, Inês C; Mesquita, Raquel B R; Bordalo, Adriano A; Rangel, António O S S

    2015-02-01

    The present work describes the development of a sequential injection standard addition method for iodine speciation in bathing waters and seaweeds extracts without prior sample treatment. Iodine speciation was obtained by assessing the iodide and iodate content, the two inorganic forms of iodine in waters. For the determination of iodide, an iodide ion selective electrode (ISE) was used. The indirect determination of iodate was based on the spectrophotometric determination of nitrite (Griess reaction). For the iodate measurement, a mixing chamber was employed (flow batch approach) to explore the inherent efficient mixing, essential for the indirect determination of iodate. The application of the standard addition method enabled detection limits of 0.14 µM for iodide and 0.02 µM for iodate, together with the direct introduction of the target water samples, coastal and inland bathing waters. The results obtained were in agreement with those obtained by ICP-MS and a colorimetric reference procedure. Recovery tests also confirmed the accuracy of the developed method which was effectively applied to bathing waters and seaweed extracts. PMID:25435219

  10. Experimental evaluation of water mist with metal chloride additives for suppressing CH4/air cup-burner flames

    NASA Astrophysics Data System (ADS)

    Liu, Jianghong; Cong, Beihua

    2013-06-01

    In order to investigate the fire suppression effectiveness of water mist with metal chloride additives, ultrafine water mists of these salts with diameters about 10μm were introduced into CH4/air non-premixed flame in the cup burner. Results showed that these droplets hard to make itself to the flame front under the cup burner flow conditions functioned as a carrier of the vaporized solid particles or its decomposed materials. The metal chloride improved fire suppression efficacy of water mist which were affected by the type and concentration of metal chloride. On a mass basis, there is a fire suppression effectiveness relationship of MgCl2water solution/metal chlorides improves as the concentration of metal chlorides increase. However, upper additive limits exist due to the associated limiting vapour pressure of the additive.

  11. HYDROLYSIS OF MTBE IN GROUND WATER SAMPLES PRESERVED WITIH HYDROCHLORIC ACID

    EPA Science Inventory

    Conventional sampling and analytical protocols have poor sensitivity for fuel oxygenates that are alcohols, such as TBA. Because alcohols tend to stay with the water samples, they are not efficiently transferred to the gas chromatograph for separation and analysis. A common tec...

  12. GROUND WATER MONITORING AND SAMPLING: MULTI-LEVEL VERSUS TRADITIONAL METHODS WHATS WHAT?

    EPA Science Inventory

    After years of research and many publications, the question still remains: What is the best method to collect representative ground water samples from monitoring wells? Numerous systems and devices are currently available for obtaining both multi-level samples as well as traditi...

  13. PASSIVE SAMPLING OF GROUND WATER MONITORING WELLS WITHOUT PURGING MULTILEVEL WELL CHEMISTRY AND TRACER DISAPPEARANCE

    EPA Science Inventory

    It is essential that the sampling techniques utilized in groundwater monitoring provide data that accurately depicts the water quality of the sampled aquifer in the vicinity of the well. Due to the large amount of monitoring activity currently underway in the U.S.A. it is also im...

  14. Quantitative Real-Time Legionella PCR for Environmental Water Samples: Data Interpretation

    PubMed Central

    Joly, Philippe; Falconnet, Pierre-Alain; André, Janine; Weill, Nicole; Reyrolle, Monique; Vandenesch, François; Maurin, Max; Etienne, Jerome; Jarraud, Sophie

    2006-01-01

    Quantitative Legionella PCRs targeting the 16S rRNA gene (specific for the genus Legionella) and the mip gene (specific for the species Legionella pneumophila) were applied to a total of 223 hot water system samples (131 in one laboratory and 92 in another laboratory) and 37 cooling tower samples (all in the same laboratory). The PCR results were compared with those of conventional culture. 16S rRNA gene PCR results were nonquantifiable for 2.8% of cooling tower samples and up to 39.1% of hot water system samples, and this was highly predictive of Legionella CFU counts below 250/liter. PCR cutoff values for identifying hot water system samples containing >103 CFU/liter legionellae were determined separately in each laboratory. The cutoffs differed widely between the laboratories and had sensitivities from 87.7 to 92.9% and specificities from 77.3 to 96.5%. The best specificity was obtained with mip PCR. PCR cutoffs could not be determined for cooling tower samples, as the results were highly variable and often high for culture-negative samples. Thus, quantitative Legionella PCR appears to be applicable to samples from hot water systems, but the positivity cutoff has to be determined in each laboratory. PMID:16597985

  15. Assessment of water quality index of bore well water samples from some selected locations of South Gujarat, India.

    PubMed

    Tripathi, S; Patel, H M; Srivastava, P K; Bafna, A M

    2013-10-01

    The present study calculates the water quality index (WQI) of some selected sites from South Gujarat (India) and assesses the impact of industries, agriculture and human activities. Chemical parameters were monitored for the calculation of WQI of some selected bore well samples. The results revealed that the WQI of the some bore well samples exceeded acceptable levels due to the dumping of wastes from municipal, industrial and domestic sources and agricultural runoff as well. Inverse Distance Weighting (IDW) was implemented for interpolation of each water quality parameter (pH, EC, alkalinity, total hardness, chloride, nitrate and sulphate) for the entire sampled area. The bore water is unsuitable for drinking and if the present state of affairs continues for long, it may soon become an ecologically dead bore. PMID:25906591

  16. An Optimized Method for Quantification of Pathogenic Leptospira in Environmental Water Samples.

    PubMed

    Riediger, Irina N; Hoffmaster, Alex R; Casanovas-Massana, Arnau; Biondo, Alexander W; Ko, Albert I; Stoddard, Robyn A

    2016-01-01

    Leptospirosis is a zoonotic disease usually acquired by contact with water contaminated with urine of infected animals. However, few molecular methods have been used to monitor or quantify pathogenic Leptospira in environmental water samples. Here we optimized a DNA extraction method for the quantification of leptospires using a previously described Taqman-based qPCR method targeting lipL32, a gene unique to and highly conserved in pathogenic Leptospira. QIAamp DNA mini, MO BIO PowerWater DNA and PowerSoil DNA Isolation kits were evaluated to extract DNA from sewage, pond, river and ultrapure water samples spiked with leptospires. Performance of each kit varied with sample type. Sample processing methods were further evaluated and optimized using the PowerSoil DNA kit due to its performance on turbid water samples and reproducibility. Centrifugation speeds, water volumes and use of Escherichia coli as a carrier were compared to improve DNA recovery. All matrices showed a strong linearity in a range of concentrations from 106 to 10° leptospires/mL and lower limits of detection ranging from <1 cell /ml for river water to 36 cells/mL for ultrapure water with E. coli as a carrier. In conclusion, we optimized a method to quantify pathogenic Leptospira in environmental waters (river, pond and sewage) which consists of the concentration of 40 mL samples by centrifugation at 15,000×g for 20 minutes at 4°C, followed by DNA extraction with the PowerSoil DNA Isolation kit. Although the method described herein needs to be validated in environmental studies, it potentially provides the opportunity for effective, timely and sensitive assessment of environmental leptospiral burden. PMID:27487084

  17. An Optimized Method for Quantification of Pathogenic Leptospira in Environmental Water Samples

    PubMed Central

    Riediger, Irina N.; Hoffmaster, Alex R.; Biondo, Alexander W.; Ko, Albert I.; Stoddard, Robyn A.

    2016-01-01

    Leptospirosis is a zoonotic disease usually acquired by contact with water contaminated with urine of infected animals. However, few molecular methods have been used to monitor or quantify pathogenic Leptospira in environmental water samples. Here we optimized a DNA extraction method for the quantification of leptospires using a previously described Taqman-based qPCR method targeting lipL32, a gene unique to and highly conserved in pathogenic Leptospira. QIAamp DNA mini, MO BIO PowerWater DNA and PowerSoil DNA Isolation kits were evaluated to extract DNA from sewage, pond, river and ultrapure water samples spiked with leptospires. Performance of each kit varied with sample type. Sample processing methods were further evaluated and optimized using the PowerSoil DNA kit due to its performance on turbid water samples and reproducibility. Centrifugation speeds, water volumes and use of Escherichia coli as a carrier were compared to improve DNA recovery. All matrices showed a strong linearity in a range of concentrations from 106 to 10° leptospires/mL and lower limits of detection ranging from <1 cell /ml for river water to 36 cells/mL for ultrapure water with E. coli as a carrier. In conclusion, we optimized a method to quantify pathogenic Leptospira in environmental waters (river, pond and sewage) which consists of the concentration of 40 mL samples by centrifugation at 15,000×g for 20 minutes at 4°C, followed by DNA extraction with the PowerSoil DNA Isolation kit. Although the method described herein needs to be validated in environmental studies, it potentially provides the opportunity for effective, timely and sensitive assessment of environmental leptospiral burden. PMID:27487084

  18. Classification of Water Masses and Targeted Sampling of Ocean Plankton Populations by an Autonomous Underwater Vehicle

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Ryan, J. P.; Bellingham, J. G.; Harvey, J.; McEwen, R.; Chavez, F.; Scholin, C.

    2011-12-01

    Autonomous underwater vehicles (AUVs) are playing an increasingly active role in oceanographic surveys due to their mobility, efficiency, and growing intelligence. The Dorado AUV is equipped with a comprehensive suite of in situ sensors and ten 1.8-liter water samplers (called "gulpers"). During an October 2010 experiment in Monterey Bay, the AUV ran our autonomous peak-capture algorithm to acquire chlorophyll/backscatter peak samples from a phytoplankton bloom, allowing biologists to successfully monitor fluctuations in harmful microalgae (Psuedo-nitzschia spp.), the toxin they produce (domoic acid), and co-occurring zooplankton (invertebrate larvae and copepods) over space and time. For further investigations of the complex marine ecosystem in northern Monterey Bay, we set a more challenging goal: when the AUV flies from an upwelling shadow region (stratified water column) through an upwelling front into newly upwelled water, can it autonomously distinguish among water columns with different vertical structures and accordingly sample plankton populations on either side of, as well as within, the upwelling front? To achieve this goal, we have developed two new algorithms, one for distinguishing upwelling water columns from stratified water columns based on the vertical homogeneity of temperature, and the other for detecting an upwelling front based on the horizontal gradient of temperature. For acquiring targeted water samples, the 10 gulpers are appropriately allocated to the two distinct water columns and the front. Lockout time intervals between triggerings are set to prevent "dense triggerings". During our June 2011 experiment, the Dorado AUV flew westward from an upwelling shadow region (stratified water column) through an upwelling front, and into an upwelling water column. Three gulpers were allocated to the stratified water column, four to the front, and the remaining three to the upwelling water column. The AUV successfully detected and acquired targeted

  19. May 2013 Groundwater and Surface Water Sampling at the Rio Blanco, Colorado, Site (Data Validation Package)

    SciTech Connect

    2013-10-01

    Annual sampling was conducted at the Rio Blanco, Colorado, site for the Long-Term Hydrologic Monitoring Program May 14-16, 2013, to monitor groundwater and surface water for potential radionuclide contamination. Sampling and analyses were conducted as specified in Sampling and Analysis Plan for the U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated). A duplicate sample was collected from location CER #1 Black Sulphur. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectrometry and for tritium using the conventional and enrichment methods.

  20. May 2011 Groundwater and Surface Water Sampling at the Rio Blanco, Colorado, Site (Data Validation Package)

    SciTech Connect

    2011-12-01

    Annual sampling was conducted at the Rio Blanco, Colorado, site for the Long-Term Hydrologic Monitoring Program May 16-17, 2011, to monitor groundwater and surface water for potential radionuclide contamination. Sampling and analyses were conducted as specified in Sampling and Analysis Plan for the U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated). A duplicate sample was collected from location Johnson Artesian WL. Samples were analyzed by the U.S. Environmental Protection Agency (EPA) Radiation&Indoor Environments National Laboratory in Las Vegas, Nevada. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectrometry, and for tritium using the conventional method. Tritium was not measured using the enrichment method because the EPA laboratory no longer offers that service. Results of this monitoring at the Rio Blanco site demonstrate that groundwater and surface water outside the boundaries have not been affected by project-related contaminants.

  1. Burning of suspended coal-water slurry droplet with oil as combustion additive

    SciTech Connect

    Yao, S.C.; Manwani, P.

    1986-10-01

    Coal-water slurries have been regarded as a potential substitute for heavy fuel oil. Various demonstrations of coal-water slurry combustion have been performed; however, a fundamental understanding of how the combustion process of a slurry fuel is enhanced is still not adequate. The combustion of coal-water mixture droplets suspended on microthermocouples has been investigated. It was found that droplets of lignite coal (which is a noncaking coal) burn effectively; however, droplets of bituminous coal (which is a caking coal) are relatively difficult to burn. During the heat-up of bituminous coal-water slurry droplets may turn to ''popcorn'' and show significant agglomeration. The incomplete combustion of coal-water slurry droplets in furnaces has been reported, and this is a drawback of this process. The objective of the present study is to explore the possibility of enhancing the combustion of coal-water slurry droplets with the use of a combustible emulsified oil.

  2. Comparison of sampling strategies for monitoring water quality in mesoscale Canadian Prairie watersheds.

    PubMed

    Ross, Cody; Petzold, Halya; Penner, Amber; Ali, Genevieve

    2015-07-01

    The Canadian Prairies are subject to cold winter dynamics, spring snowmelt runoff, and summer storms; a process variability that makes it difficult to identify an adequate sampling strategy for capturing representative water quality data. Hence, our research objective was to compare multiple water quality sampling strategies for Prairie watersheds and rank them based on operational and statistical criteria. The focus was on the Catfish Creek Watershed (Manitoba, Canada), which drains into the hypereutrophic Lake Winnipeg. Water samples were collected every 7 h during the 2013 open-water season and notably analyzed for nitrate and orthophosphate. The original high-frequency dataset (7 h) was then deconstructed into lower-frequency datasets to mimic strategies involving sample collection on a daily, weekly, bi-weekly, monthly, and seasonal basis. A comparison and decision matrix was also built to assess the ability of the lower-frequency datasets to retain the statistical properties of the original (7 h) dataset. Results indicate that nutrient concentrations vary significantly over short timescales and are affected by both sampling time (day versus night) and water level fluctuations. The decision matrix revealed that seasonal sampling is sufficient when the goal is only to capture mean water quality conditions; however, sub-daily to daily sampling is required for accurate process signal representation. While we acknowledge that sampling programs designed by researchers and public agencies are often driven by different goals, we found daily sampling to be the most parsimonious strategy for the study watershed and suggest that it would help to better quantify nutrient loads to Lake Winnipeg. PMID:26038319

  3. Proton transfer pathways in an aspartate-water cluster sampled by a network of discrete states

    NASA Astrophysics Data System (ADS)

    Reidelbach, Marco; Betz, Fridtjof; Mäusle, Raquel Maya; Imhof, Petra

    2016-08-01

    Proton transfer reactions are complex transitions due to the size and flexibility of the hydrogen-bonded networks along which the protons may "hop". The combination of molecular dynamics based sampling of water positions and orientations with direct sampling of proton positions is an efficient way to capture the interplay of these degrees of freedom in a transition network. The energetically most favourable pathway in the proton transfer network computed for an aspartate-water cluster shows the pre-orientation of water molecules and aspartate side chains to be a pre-requisite for the subsequent concerted proton transfer to the product state.

  4. Analytical results for 89 water samples from the Papago Indian Reservation, Arizona

    USGS Publications Warehouse

    Ficklin, Walter H.; Ashton, Wheeler; Preston, D.J.; Nowlan, G.A.

    1978-01-01

    Eighty-nine water samples were collected from the Papago Indian Reservation during 1977 and 1978 as a part of a mineral resource study. Each sample was analyzed for copper, zinc, molybdenum, arsenic, uranium, sodium, potassium, calcium, magnesium, bicarbonate, sulfate, chloride, fluoride, and silica. Temperature, pH, and specific conductance were also measured. The data are presented in accompanying tables. Also, included are the location and a description of each sample site.

  5. Analysis of core soil and water samples from the Cactus Crater Disposal Site at Enewetak atoll

    SciTech Connect

    Robison, W.L.; Noshkin, V.E.

    1981-02-18

    Core soil samples and water samples were collected from the Cactus Crater Disposal Site at Enewetak for analysis of /sup 137/Cs, /sup 90/Sr, /sup 239 +240/Pu and /sup 241/Am by both gamma spectroscopy and, through a contractor laboratory, by wet chemistry procedures. The samples processing methods, the analytical methods and the analytical quality control are all procedures developed for the continuing Marshall Island radioecology and dose assessment work.

  6. Magnetic nanoparticles with hydrophobicity and hydrophilicity for solid-phase extraction of polycyclic aromatic hydrocarbons from environmental water samples.

    PubMed

    Xue, Shu-Wen; Tang, Min-Qiong; Xu, Li; Shi, Zhi-guo

    2015-09-11

    Magnetic nanoparticles (MNPs) featured with divinylbenzene (DVB) and sulfonate functionalities (Fe3O4-DVB-SO3(-)) were prepared via "thiol-ene" click chemistry. The hydrophobic DVB moieties were dedicated for extraction while the hydrophilic sulfonate groups were designed for dispersing the MNPs in aqueous sample solution. Thus, the specially designed material could ensure operational convenience and improve reproducibility during extraction. The application of the material was demonstrated by the extraction of polycyclic aromatic hydrocarbons (PAHs) from environmental water samples followed by gas chromatography-mass spectrometric analysis. The main factors influencing the extraction, including the type of the desorption solvent, the agitation mode, the amount of MNPs, extraction and desorption time and salt addition in sample solution, were investigated in detail. Under the optimized conditions, the proposed method showed satisfactory reproducibility with intra-day and inter-day relative standard deviations less than 16.5% and 21.2%, and low limits of detection of 1.1pgmL(-1), 0.8pgmL(-1), 1.1pgmL(-1), 1.4pgmL(-1), 0.6pgmL(-1), 2.1pgmL(-1) and 0.7pgmL(-1) for naphthalene, acenaphthene, fluorine, phenanthrene, anthracene, fluoranthene and pyrene, respectively. The developed method was also successfully used for determination of the PAHs in genuine lake and river environmental water samples by standard addition method. All the studied PAHs were detected in these waters with comparable results by the standard liquid-liquid extraction method. The developed MNPs with dual property of hydrophobicity and hydrophilicity were suitable for the treatment of water samples. The magnetic solid phase extraction based on this material was reliable and convenient. It has great potential in the preconcentration of trace analytes in complex matrix. PMID:26260841

  7. Backflushing Filters for Field Processing of Water Samples Prior to Trace-Element Analyses

    USGS Publications Warehouse

    Kennedy, V.C.; Jenne, E.A.; Burchard, J.M.

    1976-01-01

    A portable unit is described for filtering water samples at field sites in such a manner that the filtrate is suitable for analysis not only of major constituents but also of trace elments at the mocrogram-per-liter level. A battery-operated peristaltic pump forces the water sample through medical-grade silicone tubing into and through an all-plastic in-line filter which can be backflushed when sediment clogs the filter membrane. Initial filtration rate exceeds 500 milliliter/minute and, because of the backflushing feature, a total time for filtering high-sediment-bearing waster samples is greatly reduced. (Woodard-USGS)

  8. Ground-water quality in east-central New Jersey, and a plan for sampling networks

    USGS Publications Warehouse

    Harriman, D.A.; Sargent, B.P.

    1985-01-01

    Groundwater quality was evaluated in seven confined aquifers and the water table aquifer in east-central New Jersey based on 237 analyses of samples collected in 1981-82, and 225 older analyses. Investigation of the effect of land use on water quality and several sampling network proposals for the region are reported. Generally, water in the confined aquifers is of satisfactory quality for human consumption and most other uses. Iron (Fe) and manganese (Mn) concentrations exceed U.S. EPA drinking water standards in some wells screened in the Potomac-Raritan-Magothy aquifer system. Sodium (Na) concentrations in samples from three wells more than 800 ft deep in the Englishtown aquifer exceed the standard. Iron and Mn concentrations in this aquifer may also exceed the standards. Iron concentrations in the Wenonah-Mount Laurel aquifer exceed the standard. Based on 15 analyses of water from the Vincetown aquifer, Mn is the only constituent that exceeds the drinking water standard. In the Manasquan aquifer, 4 of the 16 Na determinations exceed the standard, and 8 of 16 Fe determinations exceed the standard. Water quality in the Atlantic City 800-ft sand is generally satisfactory. However, 12 Fe and 1 of 12 Mn determinations exceed the standards. For the Rio Grande water-bearing zone, 1 of 3 Fe determinations exceed the standard. The Kirkwood-Cohansey aquifer system (the water table aquifer) was the most thoroughly sampled (249 chemical analyses from 209 wells). Dissolved solids, chloride, Fe, nitrate, and Mn concentrations exceed drinking water standards in some areas. The results of chi-square tests of constituent distributions based on analyses from 158 wells in the water table aquifer indicate that calcium is higher in industrial and commercial areas; and Mg, chloride, and nitrate-plus-nitrite is higher in residential areas. (Author 's abstract)

  9. Concentration of ions in selected bottled water samples sold in Malaysia

    NASA Astrophysics Data System (ADS)

    Aris, Ahmad Zaharin; Kam, Ryan Chuan Yang; Lim, Ai Phing; Praveena, Sarva Mangala

    2013-03-01

    Many consumers around the world, including Malaysians, have turned to bottled water as their main source of drinking water. The aim of this study is to determine the physical and chemical properties of bottled water samples sold in Selangor, Malaysia. A total of 20 bottled water brands consisting of `natural mineral (NM)' and `packaged drinking (PD)' types were randomly collected and analyzed for their physical-chemical characteristics: hydrogen ion concentration (pH), electrical conductivity (EC) and total dissolved solids (TDS), selected major ions: calcium (Ca), potassium (K), magnesium (Mg) and sodium (Na), and minor trace constituents: copper (Cu) and zinc (Zn) to ascertain their suitability for human consumption. The results obtained were compared with guideline values recommended by World Health Organization (WHO) and Malaysian Ministry of Health (MMOH), respectively. It was found that all bottled water samples were in accordance with the guidelines set by WHO and MMOH except for one sample (D3) which was below the pH limit of 6.5. Both NM and PD bottled water were dominated by Na + K > Ca > Mg. Low values for EC and TDS in the bottled water samples showed that water was deficient in essential elements, likely an indication that these were removed by water treatment. Minerals like major ions were present in very low concentrations which could pose a risk to individuals who consume this water on a regular basis. Generally, the overall quality of the supplied bottled water was in accordance to standards and guidelines set by WHO and MMOH and safe for consumption.

  10. Spatio-temporal representativeness of euphotic depth in situ sampling in transitional coastal waters

    NASA Astrophysics Data System (ADS)

    Luhtala, Hanna; Tolvanen, Harri

    2016-06-01

    In dynamic coastal waters, the representativeness of spot sampling is limited to the measurement time and place due to local heterogeneity and irregular water property fluctuations. We assessed the representativeness of in situ sampling by analysing spot-sampled depth profiles of photosynthetically active radiation (PAR) in dynamic coastal archipelago waters in the south-western Finnish coast of the Baltic Sea. First, we assessed the role of spatio-temporality within the underwater light dynamics. As a part of this approach, an anomaly detection procedure was tested on a dataset including a large archipelago area and extensive temporal coverage throughout the ice-free season. The results suggest that euphotic depth variability should be treated as a spatio-temporal process rather than considering spatial and temporal dimensions separately. Second, we assessed the representativeness of spot sampling through statistical analysis of comparative data from spatially denser sampling on three test sites on two optically different occasions. The datasets revealed variability in different dimensions and scales. The suitability of a dataset to reveal wanted phenomena can usually be improved by careful planning and by clearly defining the data sampling objectives beforehand. Nonetheless, conducting a sufficient in situ sampling in dynamic coastal area is still challenging: detecting the general patterns at all the relevant dimensions is complicated by the randomness effect, which reduces the reliability of spot samples on a more detailed scale. Our results indicate that good representativeness of a euphotic depth sampling location is not a stable feature in a highly dynamic environment.

  11. Temperature programmed desorption studies of water interactions with Apollo lunar samples 12001 and 72501

    NASA Astrophysics Data System (ADS)

    Poston, Michael J.; Grieves, Gregory A.; Aleksandrov, Alexandr B.; Hibbitts, Charles A.; Dyar, M. Darby; Orlando, Thomas M.

    2015-07-01

    The desorption activation energies for water molecules chemisorbed on Apollo lunar samples 72501 (highlands soil) and 12001 (mare soil) were determined by temperature programmed desorption experiments in ultra-high vacuum. A significant difference in both the energies and abundance of chemisorption sites was observed, with 72501 retaining up to 40 times more water (by mass) and with much stronger adsorption interactions, possibly approaching 1.5 eV. The dramatic difference between the samples may be due to differences in mineralogy and surface exposure age. The distribution function of water desorption activation energies for sample 72501 was used as an initial condition to simulate water persistence through a temperature profile matching the lunar day.

  12. Regression modeling of particle size distributions in urban storm water: advancements through improved sample collection methods

    USGS Publications Warehouse

    Fienen, Michael N.; Selbig, William R.

    2012-01-01

    A new sample collection system was developed to improve the representation of sediment entrained in urban storm water by integrating water quality samples from the entire water column. The depth-integrated sampler arm (DISA) was able to mitigate sediment stratification bias in storm water, thereby improving the characterization of suspended-sediment concentration and particle size distribution at three independent study locations. Use of the DISA decreased variability, which improved statistical regression to predict particle size distribution using surrogate environmental parameters, such as precipitation depth and intensity. The performance of this statistical modeling technique was compared to results using traditional fixed-point sampling methods and was found to perform better. When environmental parameters can be used to predict particle size distributions, environmental managers have more options when characterizing concentrations, loads, and particle size distributions in urban runoff.

  13. Organic Substances Interfere with Reverse Transcription-Quantitative PCR-Based Virus Detection in Water Samples

    PubMed Central

    Katayama, Hiroyuki; Furumai, Hiroaki

    2014-01-01

    Reverse transcription (RT)-PCR-based virus detection from water samples is occasionally hampered by organic substances that are coconcentrated during virus concentration procedures. To characterize these organic substances, samples containing commercially available humic acid, which is known to inhibit RT-PCR, and river water samples were subjected to adsorption-elution-based virus concentration using an electronegative membrane. In this study, the samples before, during, and after the concentration were analyzed in terms of organic properties and virus detection efficiencies. Two out of the three humic acid solutions resulted in RT-quantitative PCR (qPCR) inhibition that caused >3-log10-unit underestimation of spiked poliovirus. Over 60% of the organics contained in the two solutions were recovered in the concentrate, while over 60% of the organics in the uninhibited solution were lost during the concentration process. River water concentrates also caused inhibition of RT-qPCR. Organic concentrations in the river water samples increased by 2.3 to 3.9 times after the virus concentration procedure. The inhibitory samples contained organic fractions in the 10- to 100-kDa size range, which are suspected to be RT-PCR inhibitors. According to excitation-emission matrices, humic acid-like and protein-like fractions were also recovered from river water concentrates, but these fractions did not seem to affect virus detection. Our findings reveal that detailed organic analyses are effective in characterizing inhibitory substances. PMID:25527552

  14. Aqueous Processing of Atmospheric Organic Particles in Cloud Water Collected via Aircraft Sampling

    SciTech Connect

    Boone, Eric J.; Laskin, Alexander; Laskin, Julia; Wirth, Christopher; Shepson, Paul B.; Stirm, Brian H.; Pratt, Kerri A.

    2015-07-21

    Cloud water and below-cloud atmospheric particle samples were collected onboard a research aircraft during the Southern Oxidant and Aerosol Study (SOAS) over a forested region of Alabama in June 2013. The organic molecular composition of the samples was studied to gain insights into the aqueous-phase processing of organic compounds within cloud droplets. High resolution mass spectrometry with nanospray desorption electrospray ionization and direct infusion electrospray ionization were utilized to compare the organic composition of the particle and cloud water samples, respectively. Isoprene and monoterpene-derived organosulfates and oligomers were identified in both the particles and cloud water, showing the significant influence of biogenic volatile organic compound oxidation above the forested region. While the average O:C ratios of the organic compounds were similar between the atmospheric particle and cloud water samples, the chemical composition of these samples was quite different. Specifically, hydrolysis of organosulfates and formation of nitrogen-containing compounds were observed for the cloud water when compared to the atmospheric particle samples, demonstrating that cloud processing changes the composition of organic aerosol.

  15. Set Up of an Automatic Water Quality Sampling System in Irrigation Agriculture

    PubMed Central

    Heinz, Emanuel; Kraft, Philipp; Buchen, Caroline; Frede, Hans-Georg; Aquino, Eugenio; Breuer, Lutz

    2014-01-01

    We have developed a high-resolution automatic sampling system for continuous in situ measurements of stable water isotopic composition and nitrogen solutes along with hydrological information. The system facilitates concurrent monitoring of a large number of water and nutrient fluxes (ground, surface, irrigation and rain water) in irrigated agriculture. For this purpose we couple an automatic sampling system with a Wavelength-Scanned Cavity Ring Down Spectrometry System (WS-CRDS) for stable water isotope analysis (δ2H and δ18O), a reagentless hyperspectral UV photometer (ProPS) for monitoring nitrate content and various water level sensors for hydrometric information. The automatic sampling system consists of different sampling stations equipped with pumps, a switch cabinet for valve and pump control and a computer operating the system. The complete system is operated via internet-based control software, allowing supervision from nearly anywhere. The system is currently set up at the International Rice Research Institute (Los Baños, The Philippines) in a diversified rice growing system to continuously monitor water and nutrient fluxes. Here we present the system's technical set-up and provide initial proof-of-concept with results for the isotopic composition of different water sources and nitrate values from the 2012 dry season. PMID:24366178

  16. Set up of an automatic water quality sampling system in irrigation agriculture.

    PubMed

    Heinz, Emanuel; Kraft, Philipp; Buchen, Caroline; Frede, Hans-Georg; Aquino, Eugenio; Breuer, Lutz

    2013-01-01

    We have developed a high-resolution automatic sampling system for continuous in situ measurements of stable water isotopic composition and nitrogen solutes along with hydrological information. The system facilitates concurrent monitoring of a large number of water and nutrient fluxes (ground, surface, irrigation and rain water) in irrigated agriculture. For this purpose we couple an automatic sampling system with a Wavelength-Scanned Cavity Ring Down Spectrometry System (WS-CRDS) for stable water isotope analysis (δ2H and δ18O), a reagentless hyperspectral UV photometer (ProPS) for monitoring nitrate content and various water level sensors for hydrometric information. The automatic sampling system consists of different sampling stations equipped with pumps, a switch cabinet for valve and pump control and a computer operating the system. The complete system is operated via internet-based control software, allowing supervision from nearly anywhere. The system is currently set up at the International Rice Research Institute (Los Baños, The Philippines) in a diversified rice growing system to continuously monitor water and nutrient fluxes. Here we present the system's technical set-up and provide initial proof-of-concept with results for the isotopic composition of different water sources and nitrate values from the 2012 dry season. PMID:24366178

  17. Exploring water cycle dynamics through sampling multitude stable water isotope pools in a small developed landscape of Germany

    NASA Astrophysics Data System (ADS)

    Orlowski, N.; Kraft, P.; Breuer, L.

    2015-02-01

    Conducting a dual stable water isotope (δ2H and δ18O) study in the developed landscape of the Schwingbach catchment (Germany) helped to unravel connectivity and disconnectivity between the different water cycle components. The two-year weekly to biweekly measurements of precipitation, stream, and groundwater isotopes revealed that surface and groundwater are decoupled from the annual precipitation cycle but showed bidirectional interactions between each other. Seasonal variations based on temperature effects were observed in the precipitation signal but neither reflected in stream nor in groundwater isotopic signatures. Apparently, snowmelt played a fundamental role for groundwater recharge explaining the observed differences to precipitation δ-values. A spatially distributed snapshot sampling of soil water isotopes in two soil depths at 52 sampling points across different land uses (arable land, forest, and grassland) revealed that top soil isotopic signatures were similar to the precipitation input signal. Preferential water flow paths occurred under forested soils explaining the isotopic similarities between top and subsoil isotopic signatures. Due to human-impacted agricultural land use (tilling and compression) of arable and grassland soils, water delivery to the deeper soil layers was reduced, resulting in significant different isotopic signatures. However, the land use influence smoothed out with depth and soil water approached groundwater δ-values. Seasonally tracing stable water isotopes through soil profiles showed that the influence of new percolating soil water decreased with depth as no remarkable seasonality in soil isotopic signatures was obvious at depth > 0.9 m and constant values were observed through space and time. Little variation in individual isotope time series of stream and groundwater restricted the use of classical isotope hydrology techniques e.g. mean transit time estimation or hydrograph separation. Still, tracing stable water

  18. Crystallization of thin water films on graphite: Effects of n-hexane, formaldehyde, acetone, and methanol additives

    NASA Astrophysics Data System (ADS)

    Souda, Ryutaro

    2015-12-01

    Interactions of molecular additives with amorphous solid water have been investigated using time-of-flight secondary ion mass spectrometry and temperature programmed desorption. The crystallization temperature of water on a clean graphite substrate decreases from the bulk value of 160 K to 150 K when water deposition temperature increases from 20 K to 100 K. This phenomenon is induced by the formation of a specifically oriented water layer at the interface, as evidenced by that a submonolayer of n-hexane adspecies on graphite quenches this behavior. Thermal desorption spectra of additives reflect their hydration forms. The n-hexane molecules are trapped in the interior of a porous water film via hydrophobic hydration and released explosively during crystallization. The thermal desorption spectra of methanol resemble those of water from multilayer films because methanol can enter the hydrogen-bond network of water via hydrophilic hydration. The hydration of formaldehyde is hydrophobic in nature despite the presence of the polar carbonyl group. Features of both hydrophilic and hydrophobic hydrations are identifiable in acetone-water interactions; the branching ratio depends on the water preparation method and substrate.

  19. Using high-frequency water quality data to assess sampling strategies for the EU Water Framework Directive

    NASA Astrophysics Data System (ADS)

    Skeffington, R. A.; Halliday, S. J.; Wade, A. J.; Bowes, M. J.; Loewenthal, M.

    2015-05-01

    The EU Water Framework Directive (WFD) requires that the ecological and chemical status of water bodies in Europe should be assessed, and action taken where possible to ensure that at least "good" quality is attained in each case by 2015. This paper is concerned with the accuracy and precision with which chemical status in rivers can be measured given certain sampling strategies, and how this can be improved. High-frequency (hourly) chemical data from four rivers in southern England were subsampled to simulate different sampling strategies for four parameters used for WFD classification: dissolved phosphorus, dissolved oxygen, pH and water temperature. These data sub-sets were then used to calculate the WFD classification for each site. Monthly sampling was less precise than weekly sampling, but the effect on WFD classification depended on the closeness of the range of concentrations to the class boundaries. In some cases, monthly sampling for a year could result in the same water body being assigned to three or four of the WFD classes with 95% confidence, due to random sampling effects, whereas with weekly sampling this was one or two classes for the same cases. In the most extreme case, the same water body could have been assigned to any of the five WFD quality classes. Weekly sampling considerably reduces the uncertainties compared to monthly sampling. The width of the weekly sampled confidence intervals was about 33% that of the monthly for P species and pH, about 50% for dissolved oxygen, and about 67% for water temperature. For water temperature, which is assessed as the 98th percentile in the UK, monthly sampling biases the mean downwards by about 1 °C compared to the true value, due to problems of assessing high percentiles with limited data. Low-frequency measurements will generally be unsuitable for assessing standards expressed as high percentiles. Confining sampling to the working week compared to all 7 days made little difference, but a modest

  20. Interim results of quality-control sampling of surface water for the Upper Colorado River National Water-Quality Assessment Study Unit, water years 1995-96

    USGS Publications Warehouse

    Spahr, N.E.; Boulger, R.W.

    1997-01-01

    Quality-control samples provide part of the information needed to estimate the bias and variability that result from sample collection, processing, and analysis. Quality-control samples of surface water collected for the Upper Colorado River National Water-Quality Assessment study unit for water years 1995?96 are presented and analyzed in this report. The types of quality-control samples collected include pre-processing split replicates, concurrent replicates, sequential replicates, post-processing split replicates, and field blanks. Analysis of the pre-processing split replicates, concurrent replicates, sequential replicates, and post-processing split replicates is based on differences between analytical results of the environmental samples and analytical results of the quality-control samples. Results of these comparisons indicate that variability introduced by sample collection, processing, and handling is low and will not affect interpretation of the environmental data. The differences for most water-quality constituents is on the order of plus or minus 1 or 2 lowest rounding units. A lowest rounding unit is equivalent to the magnitude of the least significant figure reported for analytical results. The use of lowest rounding units avoids some of the difficulty in comparing differences between pairs of samples when concentrations span orders of magnitude and provides a measure of the practical significance of the effect of variability. Analysis of field-blank quality-control samples indicates that with the exception of chloride and silica, no systematic contamination of samples is apparent. Chloride contamination probably was the result of incomplete rinsing of the dilute cleaning solution from the outlet ports of the decaport sample splitter. Silica contamination seems to have been introduced by the blank water. Sampling and processing procedures for water year 1997 have been modified as a result of these analyses.

  1. Detection of protozoa in water samples by formalin/ether concentration method.

    PubMed

    Lora-Suarez, Fabiana; Rivera, Raul; Triviño-Valencia, Jessica; Gomez-Marin, Jorge E

    2016-09-01

    Methods to detect protozoa in water samples are expensive and laborious. We evaluated the formalin/ether concentration method to detect Giardia sp., Cryptosporidium sp. and Toxoplasma in water. In order to test the properties of the method, we spiked water samples with different amounts of each protozoa (0, 10 and 50 cysts or oocysts) in a volume of 10 L of water. Immunofluorescence assay was used for detection of Giardia and Cryptosporidium. Toxoplasma oocysts were identified by morphology. The mean percent of recovery in 10 repetitions of the entire method, in 10 samples spiked with ten parasites and read by three different observers, were for Cryptosporidium 71.3 ± 12, for Giardia 63 ± 10 and for Toxoplasma 91.6 ± 9 and the relative standard deviation of the method was of 17.5, 17.2 and 9.8, respectively. Intraobserver variation as measured by intraclass correlation coefficient, was fair for Toxoplasma, moderate for Cryptosporidium and almost perfect for Giardia. The method was then applied in 77 samples of raw and drinkable water in three different plant of water treatment. Cryptosporidium was found in 28 of 77 samples (36%) and Giardia in 31 of 77 samples (40%). Theses results identified significant differences in treatment process to reduce the presence of Giardia and Cryptosporidium. In conclusion, the formalin ether method to concentrate protozoa in water is a new alternative for low resources countries, where is urgently need to monitor and follow the presence of theses protozoa in drinkable water. PMID:27219047

  2. Identification and Genotyping of Mycobacterium tuberculosis Isolated From Water and Soil Samples of a Metropolitan City

    PubMed Central

    Velayati, Ali Akbar; Farnia, Parissa; Mozafari, Mohadese; Malekshahian, Donya; Farahbod, Amir Masoud; Seif, Shima; Rahideh, Snaz

    2015-01-01

    BACKGROUND: The potential role of environmental Mycobacterium tuberculosis in the epidemiology of TB remains unknown. We investigated the transmission of M tuberculosis from humans to the environment and the possible transmission of M tuberculosis from the environment to humans. METHODS: A total of 1,500 samples were collected from three counties of the Tehran, Iran metropolitan area from February 2012 to January 2014. A total of 700 water samples (47%) and 800 soil samples (53%) were collected. Spoligotyping and the mycobacterial interspersed repetitive units-variable number of tandem repeats typing method were performed on DNA extracted from single colonies. Genotypes of M tuberculosis strains isolated from the environment were compared with the genotypes obtained from 55 patients with confirmed pulmonary TB diagnosed during the study period in the same three counties. RESULTS: M tuberculosis was isolated from 11 of 800 soil samples (1%) and 71 of 700 water samples (10%). T family (56 of 82, 68%) followed by Delhi/CAS (11 of 82, 13.4%) were the most frequent M tuberculosis superfamilies in both water and soil samples. Overall, 27.7% of isolates in clusters were related. No related typing patterns were detected between soil, water, and clinical isolates. The most frequent superfamily of M tuberculosis in clinical isolates was Delhi/CAS (142, 30.3%) followed by NEW-1 (127, 27%). The bacilli in contaminated soil (36%) and damp water (8.4%) remained reculturable in some samples up to 9 months. CONCLUSIONS: Although the dominant M tuberculosis superfamilies in soil and water did not correspond to the dominant M tuberculosis family in patients, the presence of circulating genotypes of M tuberculosis in soil and water highlight the risk of transmission. PMID:25340935

  3. Preserving ground water samples with hydrochloric acid does not result in the formation of chloroform

    USGS Publications Warehouse

    Squillace, Paul J.; Pankow, James F.; Barbash, Jack E.; Price, Curtis V.; Zogorski, John S.

    1999-01-01

    Water samples collected for the determination of volatile organic compounds (VOCs) are often preserved with hydrochloric acid (HCl) to inhibit the biotransformation of the analytes of interest until the chemical analyses can he performed. However, it is theoretically possible that residual free chlorine in the HCl can react with dissolved organic carbon (DOC) to form chloroform via the haloform reaction. Analyses of 1501 ground water samples preserved with HCl from the U.S. Geological Survey's National Water-Quality Assessment Program indicate that chloroform was the most commonly detected VOC among 60 VOCs monitored. The DOC concentrations were not significantly larger in samples with detectable chloroform than in those with no delectable chloroform, nor was there any correlation between the concentrations of chloroform and DOC. Furthermore, chloroform was detected more frequently in shallow ground water in urban areas (28.5% of the wells sampled) than in agricultural areas (1.6% of the wells sampled), which indicates that its detection was more related to urban land-use activities than to sample acidification. These data provide strong evidence that acidification with HCl does not lead to the production of significant amounts of chloroform in ground water samples. To verify these results, an acidification study was designed to measure the concentrations of all trihalomethanes (THMs) that can form as a result of HCl preservation in ground water samples and to determine if ascorbic acid (C6H8O6) could inhibit this reaction if it did occur. This study showed that no THMs were formed as a result of HCl acidification, and that ascorbic acid had no discernible effect on the concentrations of THMs measured.

  4. Concentration and characteristics of depleted uranium in biological and water samples collected in Bosnia and Herzegovina.

    PubMed

    Jia, Guogang; Belli, Maria; Sansone, Umberto; Rosamilia, Silvia; Gaudino, Stefania

    2006-01-01

    During Balkan conflicts in 1994-1995, depleted uranium (DU) ordnance was employed and was left in the battlefield. Health concern is related to the risk arising from contamination of the environment with DU penetrators and dust. In order to evaluate the impact of DU on the environment and population in Bosnia and Herzegovina, radiological survey of DU in biological and water samples were carried out over the period 12-24 October 2002. The uranium isotopic concentrations in biological samples collected in Bosnia and Herzegovina, mainly lichens, mosses and barks, were found to be in the range of 0.27-35.7 Bq kg(-1) for (238)U, 0.24-16.8 Bq kg(-1) for (234)U, and 0.02-1.11 Bq kg(-1) for (235)U, showing uranium levels to be higher than in the samples collected at the control site. Moreover, the (236)U in some of the samples was detectable. The isotopic ratios of (234)U/(238)U showed DU to be detectable in many biological samples at most sites examined, but in very low levels. The presence of DU in the biological samples was as a result of DU contamination in air. The uranium concentrations in water samples collected in Bosnia and Herzegovina were found to be in the range of 0.27-16.2 m Bq l(-1) for (238)U, 0.41-15.6 m Bq l(-1) for (234)U and 0.012-0.695 m Bq l(-1) for (235)U, and two water samples were observed to be DU positive; these values are much lower than those in mineral water found in central Italy and below the WHO guideline for public drinking water. From radiotoxicological point of view, at this moment there is no significant radiological risk related to these investigated sites in terms of possible DU contamination of water and/or plants. PMID:16806612

  5. The Salmonella mutagenicity of industrial, surface and ground water samples of Aligarh region of India.

    PubMed

    Siddiqui, Athar Habib; Ahmad, Masood

    2003-11-10

    The genotoxicity of three water bodies, viz. industrial waste water of Aligarh city, ground water pumped out from the industrial area of Aligarh, and river water of Yamuna, downstream of Agra, was carried out by means of Ames plate incorporation test and the Ames fluctuation test. All the test samples were significantly mutagenic in both the testing systems. The ground water and river water samples were subjected to XAD concentration prior to the mutagenicity/genotoxicity testing, while the industrial waste water was used directly. Whereas TA98, TA102 and TA104 strains have been found to be maximally sensitive in the Ames plate incorporation assay conducted for various water samples, TA98 and TA100 strains were the most responsive strains in the Ames fluctuation test. The apparent disparity in the sensitivity patterns of various Ames strains by plate incorporation and fluctuation assays could be attributed to a large extent to the different conventional ways of interpretation of the data in these systems. PMID:14568291

  6. Addition of a Magnetite Layer onto a Polysulfone Water Treatment Membrane to Enhance Virus Removal

    NASA Astrophysics Data System (ADS)

    Raciny, Isabel

    The applicability of low-pressure membranes systems in distributed (point of use) water treatment is hindered by, among other things, their inability to remove potentially harmful viruses and ions via size exclusion. According to the USEPA and the Safe Drinking Water Act, drinking water treatment processes must be designed for 4-log virus removal. Batch experiments using magnetite nanoparticle (nano-Fe3O4) suspensions and water filtration experiments with Polysulfone (PSf) membranes coated with nano-Fe3O 4 were conducted to assess the removal of a model virus (bacteriophage MS2). The membranes were coated via a simple filtration protocol. Unmodified membranes were a poor adsorbent for MS2 bacteriophage with less than 0.5-log removal, whereas membranes coated with magnetite nanoparticles exhibited a removal efficiency exceeding 99.99% (4-log). Thus, a cartridge of PSf membranes coated with nano-Fe3O4 particles could be used to remove viruses from water. Such membranes showed negligible iron leaching into the filtrate, thus obviating concern about colored water. Further research is needed to reduce the loss of water flux caused by coating.

  7. Hydrogen isotopes from source water to leaf lipid in a continental-scale sample network

    NASA Astrophysics Data System (ADS)

    Nelson, Daniel; Kahmen, Ansgar

    2015-04-01

    Sedimentary plant waxes are useful paleoclimate proxies because they are preserved in depositional settings on geologic timescales and the isotopic composition of the hydrogen in these molecules reflects that of the source water available during biosynthesis. This application is based largely on empirical calibrations that have demonstrated continental-scale correlations between source water and lipid hydrogen isotope values. However, the importance of variable net isotopic fractionation between source water and lipid for different species and environmental conditions is increasingly recognized. Isotopic enrichment of leaf water during transpiration is key among these secondary factors, and is itself sensitive to changes in hydroclimate. Leaf water enrichment also occurs prior to photosynthetic water uptake, and is therefore independent from cellular-level biomarker synthesis. Mechanistic models can predict the mean leaf water hydrogen isotope composition from readily available meteorological variables. This permits global-scale isoscape maps of leaf water isotopic composition and enrichment above source water to be generated, but these models have not been widely validated at continental spatial scales. We have established a network of twenty-one sites across Europe where we are sampling for leaf-, xylem-, and soil-water isotopes (H and O) at approximately 5-week intervals over the summer growing season. We augment the sample set with weekly to monthly precipitation samples and early- and late-season plant wax lipid samples. Collaborators at each site are conducting the sampling, and most sites are members of the FLUXNET tower network that also record high-resolution meteorological data. We present information on the implementation of the network and preliminary results from the 2014 summer season. The complete dataset will be used to track the evolution of water isotopes from source to leaf water and from leaf water to lipid hydrogen across diverse environments

  8. Determination of (210)Po in drinking water and urine samples using copper sulfide microprecipitation.

    PubMed

    Guérin, Nicolas; Dai, Xiongxin

    2014-06-17

    Polonium-210 ((210)Po) can be rapidly determined in drinking water and urine samples by alpha spectrometry using copper sulfide (CuS) microprecipitation. For drinking water, Po in 10 mL samples was directly coprecipitated onto the filter for alpha counting without any purification. For urine, 10 mL of sample was heated, oxidized with KBrO3 for a short time (∼5 min), and subsequently centrifuged to remove the suspended organic matter. The CuS microprecipitation was then applied to the supernatant. Large batches of samples can be prepared using this technique with high recoveries (∼85%). The figures of merit of the methods were determined, and the developed methods fulfill the requirements for emergency and routine radioassays. The efficiency and reliability of the procedures were confirmed using spiked samples. PMID:24906041

  9. May 2012 Groundwater and Surface Water Sampling at the Rio Blanco, Colorado, Site (Data Validation Package)

    SciTech Connect

    2012-12-01

    Annual sampling was conducted at the Rio Blanco, Colorado, site for the Long-Term Hydrologic Monitoring Program May 9-10, 2012, to monitor groundwater and surface water for potential radionuclide contamination. Sampling and analyses were conducted as specified in Sampling and Analysis Plan for the U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated). A duplicate sample was collected from location Johnson Artesian WL. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectrometry and for tritium using the conventional and enrichment methods. Results of this monitoring at the Rio Blanco site demonstrate that groundwater and surface water outside the site boundaries have not been affected by project-related contaminants.

  10. Field guidelines for collection, treatment, and analysis of water samples, Montana district

    USGS Publications Warehouse

    Knapton, J.R.

    1985-01-01

    This manual provides a set of standardized guidelines and quality-control procedures for the collection and preservation of water samples and defines procedures for field analyses of unstable constituents or properties. Seldom is the water being samples of such uniformity that a single grab sample is representative of the whole. For this reason a variety of sampler types and sampling methods have been devised. Descriptions and procedures for field use are given for a number of sampler types. Several methods of sampling are described for which these samplers can be used. Sample-processing devices such as sample splitters and filtration apparatus are discussed along with methods of cleaning. Depending on the type of analysis to be performed in the laboratory, samples may need to be preserved shortly after collection. Various types of preservation are described in detail. Analyses for unstable constituents or properties are of necessity accomplished in the field. This manual addresses analytical techniques and quality assurance for: (1) Water temperature, (2) specific conductance, (3) pH, (4) alkalinity, (5) dissolved oxygen, and (6) bacteria. Examples of field report forms are given as attachments. Information pertinent to certain field calculations is also presented. (USGS)

  11. Laboratory investigation into the contribution of contaminants to ground water from equipment materials used in sampling

    SciTech Connect

    Gilmore, Tyler J.; Mitroshkov, Alexandre V.; Dresel, P. Evan; Sklarew, Deborah S.

    2004-07-31

    Benzene contamination was detected in water samples from the Ogallala aquifer beneath and adjacent to the Department of Energy's (DOE) Pantex Plant near Amarillo, Texas. DOE assembled a Technical Assistance Team to evaluate the source of benzene. One of the team's recommendations was to assess whether the sampling equipment material could be a source of benzene and other volatile organic compounds. As part of this investigation, laboratory testing of the sample equipment material was conducted. Results from the laboratory tests indicated that the equipment material did, in fact, contribute volatile and semi-volatile organic compounds to the groundwater samples. Specifically, three materials were identified as contributing contaminants to water samples. The nylon-11 tubing used contributed benzene and the plasticizer N-butylbenzenesulfonamide (NBSA), the urethane-coated nylon well liner contributed toluene and trace amounts of NBSA, while the sampling port "spacer" material made of nylon/polypropylene/polyester-composite contributed trace amounts of toluene and NBSA. While the concentrations of benzene and toluene measured in the laboratory tests are below the concentrations measured in actual groundwater samples, the equipment material was found to contribute organics to the test water rendering the results reported for the groundwater samples highly suspect.

  12. Hydrogeologic framework and sampling design for an assessment of agricultural pesticides in ground water in Pennsylvania

    USGS Publications Warehouse

    Lindsey, Bruce D.; Bickford, Tammy M.

    1999-01-01

    State agencies responsible for regulating pesticides are required by the U.S. Environmental Protection Agency to develop state management plans for specific pesticides. A key part of these management plans includes assessing the potential for contamination of ground water by pesticides throughout the state. As an example of how a statewide assessment could be implemented, a plan is presented for the Commonwealth of Pennsylvania to illustrate how a hydrogeologic framework can be used as a basis for sampling areas within a state with the highest likelihood of having elevated pesticide concentrations in ground water. The framework was created by subdividing the state into 20 areas on the basis of physiography and aquifer type. Each of these 20 hydrogeologic settings is relatively homogeneous with respect to aquifer susceptibility and pesticide use?factors that would be likely to affect pesticide concentrations in ground water. Existing data on atrazine occurrence in ground water was analyzed to determine (1) which areas of the state already have suffi- cient samples collected to make statistical comparisons among hydrogeologic settings, and (2) the effect of factors such as land use and aquifer characteristics on pesticide occurrence. The theoretical vulnerability and the results of the data analysis were used to rank each of the 20 hydrogeologic settings on the basis of vulnerability of ground water to contamination by pesticides. Example sampling plans are presented for nine of the hydrogeologic settings that lack sufficient data to assess vulnerability to contamination. Of the highest priority areas of the state, two out of four have been adequately sampled, one of the three areas of moderate to high priority has been adequately sampled, four of the nine areas of moderate to low priority have been adequately sampled, and none of the three low priority areas have been sampled. Sampling to date has shown that, even in the most vulnerable hydrogeologic settings

  13. Factors controlling elevated lead concentrations in water samples from aquifer systems in Florida

    USGS Publications Warehouse

    Katz, B.G.; Bullen, M.P.; Bullen, T.D.; Hansard, Paul

    1999-01-01

    Concentrations of total lead (Pb) and dissolved Pb exceeded the U.S. Environmental Protection Agency action level of 15 micrograms per liter (mg/L) in approximately 19 percent and 1.3 percent, respectively, of ground-water samples collected during 1991-96 from a statewide network of monitoring wells designed to delineate background water quality of Florida's major aquifer systems. Differences in total Pb concentrations among aquifer systems reflect the combined influence of anthropogenic sources and chemical conditions in each system. A highly significant (p<0.001) difference in median total Pb concentrations was found for water samples from wells with water-level recording devices that contain Pb-counterweights (14 mg/L) compared to non-recorder wells (2 mg/L). Differences between total Pb concentrations for recorder and non-recorder wells are even more pronounced when compared for each aquifer system. The largest differences for recorder status are found for the surficial aquifer system, where median total Pb concentrations are 44 and 2.4 mg/L for recorder wells and non-recorder wells, respectively. Leaching of Pb from metal casing materials is another potential source of Pb in ground water samples. Median total Pb concentrations in water samples from the surficial, intermediate, and Floridan aquifer systems are higher from recorder wells cased with black iron than for recorder wells with steel and PVC casing material. Stable isotopes of Pb were used in this study to distinguish between anthropogenic and natural sources of Pb in ground water, as Pb retains the isotopic signature of the source from which it is derived. Based on similarities between slopes and intercepts of trend lines for various sample types (plots of 206Pb/204Pb versus 208Pb/204Pb and 207Pb/204Pb versus 208Pb/204Pb) the predominant source of total Pb in water samples from the surficial aquifer system is corrosion of Pb counterweights. It is likely that only ground-water samples, not the aquifer

  14. Water Column Sampling Capabilities of the NEPTUNE Canada Regional Cabled Observatory

    NASA Astrophysics Data System (ADS)

    Mihaly, S. F.; Neptune Canada Science

    2010-12-01

    The NEPTUNE Canada Regional Observatory affords a wide range of opportunities to conduct adaptive and high-temporal resolution water column property studies. Intensive sites are located in a shallow near-shore environment (Folger Passage), a shelf-slope-break region (Barkley Upper Slope) and a deep offshore mid-ocean spreading centre (Endeavour Ridge). The Folger Passage site has instrument platforms at 100 m and 23 m which are located near the mouth of Barkley Sound on the west coast of Vancouver Island. Instruments include upward-looking surface-wave resolving Acoustic Doppler Current Profilers (ADCPs), multi-frequency echo-sounders to measure backscatter from zooplankton and bottom pressure recorders to assess long-wave variability (e.g. tsunami, shelf waves, tidal). The near-bottom water column is sampled for salinity, temperature, oxygen, chlorophyll, turbidity, photosynthetically active light and, in addition, there are fine scale measurements of the velocity structure of the bottom-boundary layer. Water column measurements at the 400 metre deep Barkley Upper Slope site are facilitated by a world leading Vertical Profiling System (VPS). This winch operated system will profile a suite of instruments through the water column at up to 4 cycles per day. Optical measurements consist of a pair of hyperspectral radiometers to characterise downwelling irradiation and upwelling radiance, backscatter fluorescence for chlorophyll, and an optode to determine oxygen levels. A pumped CTD will provide salinity, temperature, depth as well as plumbing for a nitrate sensor, a coloured dissolved organic matter sensor and a pCO2 sensor. Acoustic instruments on the profiler consist of a 400 kHz ADCP, 200 kHz echosounder and a broad band hydrophone. With these instruments we expect to be able to explore the covariation of physical and chemical parameters with impact at a range of trophic levels, up to and including marine mammals. At the base of the VPS there is a long range ADCP

  15. Determination of boron contents in water samples collected from the Neelum valley, Azad Kashmir, Pakistan.

    PubMed

    Akram, Muhammad; Matiullah; Iqbal, Arshid; Husaini, S N; Malik, Fariha

    2011-03-01

    Intake of boron from food and drinking water may pose a risk to the public health above a certain concentration level. Therefore, knowledge of boron concentration in drinking water and food items is essential. In this context, samples of drinking water were collected from natural springs of the Neelum valley, Azad Kashmir, hit by devastating earthquake in 2005. In these samples, boron concentration was determined using neutron-induced radiography technique. To do so, unknown water samples, along with standard of known boron dried on CR-39 detectors, were irradiated with thermal neutrons. After exposure, CR-39 detectors were etched in 6 M NaOH at 70°C. The tracks produced due to the alpha particles and (7)Li ions as a result of (10)B(n,α)(7)Li reaction were counted under an optical microscope. The tracks produced in theses samples were then related to the boron contents. The measured boron concentration in water samples was found to vary from 0.105 ± 0.005 to 0.247 ± 0.013 mg/l with an average value of 0.17 ± 0.04 mg/l, which are within the acceptable limits. PMID:20306233

  16. Organochlorine insecticide residues are found in surface, irrigated water samples from several districts in Bangladesh.

    PubMed

    Chowdhury, Alamgir Zaman; Islam, Mohammad Nazrul; Moniruzzaman, Mohammed; Gan, Siew Hua; Alam, Md Khorshed

    2013-02-01

    The purpose of this study was to investigate the occurrence and distribution of organochlorines such as aldrin, dieldrin, dichlorodiphenyldichloroethylene (DDE), dichlorodiphenyldichloroethane (DDD), dichlorodiphenyltrichloroethane (DDT), endrin, lindane and heptachlor insecticide residues in irrigated surface water samples collected from 22 districts in Bangladesh. The concentrations of the pesticides were determined using gas chromatography mass spectrophotometry. Water samples from five locations (Feni, Nawabganj, Putia, Burichang and Chatak) were contaminated with DDT; the highest DDT concentration detected was 8.29 μg/L, and its metabolite, DDE, was detected at 4.06 μg/L. Water samples from four other locations (Natore, Sikderpara, Chatak and Rajoir) were contaminated with heptachlor residues, and the highest level detected was 5.24 μg/L, which is the above the maximum contaminant level recommended by the World Health Organisation. A water sample collected from Chatak, Sunamganj, was contaminated with both DDT and heptachlor pesticide residues. None of the water samples were contaminated with aldrin, DDD, dieldrin, endrin or lindane. It is concluded that continuous, long-term monitoring and essential steps to limit the use of the pesticides in Bangladesh are needed. PMID:23212886

  17. Transcriptomic profiling permits the identification of pollutant sources and effects in ambient water samples.

    PubMed

    Hasenbein, Matthias; Werner, Inge; Deanovic, Linda A; Geist, Juergen; Fritsch, Erika B; Javidmehr, Alireza; Foe, Chris; Fangue, Nann A; Connon, Richard E

    2014-01-15

    Contaminant exposure is one possible contributor to population declines of endangered fish species in the Sacramento-San Joaquin Estuary, California, including the endangered delta smelt (Hypomesus transpacificus). Herein we investigated transcriptional responses in larval delta smelt resulting from exposure to water samples collected at the Department of Water Resources Field Station at Hood, a site of concern, situated upstream of known delta smelt habitat and spawning sites and downstream of the Sacramento Regional Wastewater Treatment Plant (SRWTP). Microarray assessments indicate impacts on energy metabolism, DNA repair mechanisms and RNA processing, the immune system, development and muscle function. Transcription responses of fish exposed to water samples from Hood were compared with exposures to 9% effluent samples from SRWTP, water from the Sacramento River at Garcia Bend (SRGB), upstream of the effluent discharge, and SRGB water spiked with 2mg/L total ammonium (9% effluent equivalent). Results indicate that transcriptomic profiles from Hood are similar to 9% SRWTP effluent and ammonium spiked SRGB water, but significantly different from SRGB. SRGB samples however were also significantly different from laboratory controls, suggesting that SRWTP effluent is not solely responsible for the responses determined at Hood, that ammonium exposure likely enhances the effect of multiple-contaminant exposures, and that the observed mortality at Hood is due to the combination of both effluent discharge and contaminants arising from upstream of the tested sites. PMID:24061060

  18. Microbial profiling of South African acid mine water samples using next generation sequencing platform.

    PubMed

    Kamika, I; Azizi, S; Tekere, M

    2016-07-01

    This study monitored changes in bacterial and fungal structure in a mine water in a monthly basis over 4 months. Over the 4-month study period, mine water samples contained more bacteria (91.06 %) compared to fungi (8.94 %). For bacteria, mine water samples were dominated by Proteobacteria (39.14 to 65.06 %) followed by Firmicutes (26.34 to 28.9 %) in summer, and Cyanobacteria (27.05 %) in winter. In the collected samples, 18 % of bacteria could not be assigned to a phylum and remained unclassified suggesting hitherto vast untapped microbial diversity especially during winter. The fungal domain was the sole eukaryotic microorganism found in the mine water samples with unclassified fungi (68.2 to 91 %) as the predominant group, followed by Basidiomycota (6.9 to 27.8 %). The time of collection, which was linked to the weather, had higher impact on bacterial community than fungal community. The bacterial operational taxonomic units (OTUs) ranged from 865 to 4052 over the 4-month sampling period, while fungal OTUs varied from 73 to 249. The diversity indices suggested that the bacterial community inhabiting the mine water samples were more diverse than the fungal community. The canonical correspondence analysis (CCA) results highlighted that the bacterial community variance had the strongest relationship with water temperature, conductivity, pH, and dissolved oxygen (DO) content, as compared to fungi and water characteristics, had the greatest contribution to both bacterial and fungal community variance. The results provided the relationships between microbial community and environmental variables in the studied mining sites. PMID:26980100

  19. Electrothermal Vaporization Sample Introduction for Spaceflight Water Quality Monitoring via Gas Chromatography-Differential Mobility Spectrometry.

    PubMed

    Wallace, William T; Gazda, Daniel B; Limero, Thomas F; Minton, John M; Macatangay, Ariel V; Dwivedi, Prabha; Fernández, Facundo M

    2015-06-16

    In the history of manned spaceflight, environmental monitoring has relied heavily on archival sampling. However, with the construction of the International Space Station (ISS) and the subsequent extension in mission duration up to one year, an enhanced, real-time method for environmental monitoring is necessary. The station air is currently monitored for trace volatile organic compounds (VOCs) using gas chromatography-differential mobility spectrometry (GC-DMS) via the Air Quality Monitor (AQM), while water is analyzed to measure total organic carbon and biocide concentrations using the Total Organic Carbon Analyzer (TOCA) and the Colorimetric Water Quality Monitoring Kit (CWQMK), respectively. As mission scenarios extend beyond low Earth orbit, a convergence in analytical instrumentation to analyze both air and water samples is highly desirable. Since the AQM currently provides quantitative, compound-specific information for air samples and many of the targets in air are also common to water, this platform is a logical starting point for developing a multimatrix monitor. Here, we report on the interfacing of an electrothermal vaporization (ETV) sample introduction unit with a ground-based AQM for monitoring target analytes in water. The results show that each of the compounds tested from water have similar GC-DMS parameters as the compounds tested in air. Moreover, the ETV enabled AQM detection of dimethlsilanediol (DMSD), a compound whose analysis had proven challenging using other sample introduction methods. Analysis of authentic ISS water samples using the ETV-AQM showed that DMSD could be successfully quantified, while the concentrations obtained for the other compounds also agreed well with laboratory results. PMID:25971650

  20. 9 CFR 318.9 - Samples of products, water, dyes, chemicals, etc., to be taken for examination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Samples of products, water, dyes... ESTABLISHMENTS; REINSPECTION AND PREPARATION OF PRODUCTS General § 318.9 Samples of products, water, dyes, chemicals, etc., to be taken for examination. Samples of products, water, dyes, chemicals,...

  1. 9 CFR 318.9 - Samples of products, water, dyes, chemicals, etc., to be taken for examination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Samples of products, water, dyes... ESTABLISHMENTS; REINSPECTION AND PREPARATION OF PRODUCTS General § 318.9 Samples of products, water, dyes, chemicals, etc., to be taken for examination. Samples of products, water, dyes, chemicals,...

  2. 9 CFR 318.9 - Samples of products, water, dyes, chemicals, etc., to be taken for examination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Samples of products, water, dyes... ESTABLISHMENTS; REINSPECTION AND PREPARATION OF PRODUCTS General § 318.9 Samples of products, water, dyes, chemicals, etc., to be taken for examination. Samples of products, water, dyes, chemicals,...

  3. 9 CFR 318.9 - Samples of products, water, dyes, chemicals, etc., to be taken for examination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Samples of products, water, dyes... ESTABLISHMENTS; REINSPECTION AND PREPARATION OF PRODUCTS General § 318.9 Samples of products, water, dyes, chemicals, etc., to be taken for examination. Samples of products, water, dyes, chemicals,...

  4. Pilot study for U.S. Geological Survey Standard Reference Water Samples for pesticides

    USGS Publications Warehouse

    Friedman, L.C.; Fishman, M. J.; Boyle, D.K.

    1984-01-01

    The U. S. Geological Survey has been preparing and maintaining a library of standard reference water samples for inorganic constituents for 19 years. Recently, a pilot study was conducted to see if the reference-sample program could be expanded to include pesticides and other organic materials. Two samples containing organochlorine and organophosphorus insecticides, and chlorophenoxy acid herbicides were distributed to a number of laboratories in the United States. One of the samples also contained polychlorinated biphenyls. Interlaboratory data obtained from these round robin studies are presented with intralaboratory information on long-term stability.

  5. Proficiency test sample media for single and mixed pure cultures of water pollution indicator bacteria.

    PubMed Central

    Toombs, R W; Connor, D A

    1980-01-01

    Two transport media, NYSDH-1 and NYSDH-2, were developed for use in a split bacteriological water sample program. The media maintained 88% viability of inoculated organisms for at least 48 h, and the samples do not require special handling or reconstitution. Procedures for preparing and shipping the samples to participating laboratories were developed. A reference set of samples was analyzed in laboratories certified by either New York State or the Environmental Protection Agency. A statistical analysis was performed, and the results indicate that the media are suitable for integration into a laboratory quality control program. PMID:6778391

  6. Contactless conductometric determination of methanol and ethanol in samples containing water after their electrophoretic desalination.

    PubMed

    Tůma, Petr; Opekar, František

    2015-08-01

    Determination of the contents of methanol and ethanol in aqueous solutions was performed by measuring the permittivity of solutions using a contactless conductivity detector (C(4) D) normally used for detection in capillary electrophoresis. The detection cell is a section of a fused silica capillary with an internal diameter of 50 μm with a pair of conductivity electrodes on the external walls. The C(4) D response to samples of methanol/water and ethanol/water mixtures is linear in the concentration interval of approx. 40-100% v/v alcohol content. In the analysis of technical samples of methanol and ethanol, the determination is disturbed by the presence of even trace amounts of salts. This interference can be effectively eliminated by integrated electrophoretic desalination of the sample by the application of a direct current electric voltage with a magnitude of 10 kV to the capillary with the injected sample zone. Under these conditions, the ions migrate out of the sample zone and the detector response is controlled purely by the permittivity of the solvent/water zone. Desalinating is effective for NaCl contents in the range from 0 to 5 mmol/L NaCl. The effectiveness of the desalinating process has been verified on MeOH/water samples and in determination of the ethanol content in distilled beverages normally available in the retail network. PMID:26031907

  7. Leaf water and plant wax hydrogen isotopes in a European sample network

    NASA Astrophysics Data System (ADS)

    Nelson, D. B.; Kahmen, A.

    2014-12-01

    The hydrogen isotopic composition of plant waxes in sediments is now routinely used as a hydroclimate proxy. This application is based largely on empirical calibrations that have demonstrated continental-scale correlations between source water and lipid hydrogen isotope values. But at smaller spatial scales and for individual locations it is increasingly recognized that factors that modify apparent fractionation between source water and leaf lipid hydrogen isotope values must also be considered. Isotopic enrichment of leaf water during transpiration is key among these secondary factors, and is itself sensitive to changes in hydroclimate. Leaf water enrichment also occurs prior to photosynthetic water uptake, and is therefore independent from cellular-level biomarker synthesis. Recent advances in theory have permitted mechanistic models to be developed that can be used to predict the mean leaf water hydrogen and oxygen isotope composition from readily available meteorological variables. This permits global-scale isoscape maps of leaf water isotopic composition and enrichment above source water to be generated, but these models have not been widely validated at continental spatial scales. We have established a network of twenty-one sites across Europe where we are sampling for leaf-, xylem-, and soil-water isotopes (H and O) at approximately 5-week intervals over the summer growing season. We augment the sample set with weekly to monthly precipitation samples and early- and late-season plant wax lipid samples. Collaborators at each site are conducting the sampling, and most sites are members of the FLUXNET tower network that also record high-resolution meteorological data. We present information on the implementation of the network and preliminary results from the 2014 summer season. The complete dataset will be used to track the evolution of water isotopes from source to leaf water and from leaf water to lipid hydrogen across diverse environments. This will provide

  8. 75 FR 41725 - Food Additives Permitted in Feed and Drinking Water of Animals; Ammonium Formate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-19

    .... Background In a notice published in the Federal Register of January 11, 2008 (73 FR 2055), FDA announced that... ammonium formate as an acidifying agent in swine feed. This action is in response to a food additive... exceed 1.2 percent in swine feed. Subsequently, it was determined that the food additive is...

  9. Synthesis of DHA/EPA-rich phosphatidylcholine by immobilized phospholipase A1: effect of water addition and vacuum condition.

    PubMed

    Li, Daoming; Qin, Xiaoli; Wang, Weifei; Li, Zhigang; Yang, Bo; Wang, Yonghua

    2016-08-01

    DHA/EPA-rich phosphatidylcholine (PC) was successfully synthesized by immobilized phospholipase A1 (PLA1)-catalyzed transesterification of PC and DHA/EPA-rich ethyl esters in a solvent-free system. Effects of reaction temperature, water addition and substrate mass ratio on the incorporation of DHA/EPA were evaluated using response surface methods (RSM). Water addition had most significant effect on the incorporation. Reaction temperature and substrate mass ratio, however, had no significant effect on the incorporation. The maximal incorporation was 19.09 % (24 h) under the following conditions: temperature 55.7 °C, water addition 1.1 wt % and substrate mass ratio (ethyl esters/PC) 6.8:1. Furthermore, effects of water addition (from 0 to 1.25 wt %) on DHA/EPA incorporation and the composition of products were further investigated. The immobilized PLA1 was more active when water addition was above 0.5 wt %. By monitoring the reaction processes with different water addition, a possible reaction scheme was proposed for transesterification of PC with DHA/EPA-rich ethyl esters. In summary, PC and sn2-lysophosphatidylocholine (LPC) were predominant in the mixtures at early stages of reaction, whereas sn1-LPC and glycerophosphocholine (GPC) predominant at later stages. The vacuum employed after 24 h significantly increased the incorporation of DHA/EPA and the composition of PC, and the highest incorporation (30.31 %) of DHA/EPA was obtained at 72 h and the yield of PC was 47.2 %. PMID:27108109

  10. Cyto- and genotoxic potential of water samples from polluted areas in Kosovo.

    PubMed

    Alija, Avdulla J; Bajraktari, Ismet D; Bresgen, Nikolaus; Bojaxhi, Ekramije; Krenn, Margit; Asllani, Fisnik; Eckl, Peter M

    2016-09-01

    Reports on the state of the environment in Kosovo have emphasized that river and ground water quality is affected by pollution from untreated urban water as well as the waste water from the industry. One of the main contributors to this pollution is located in Obiliq (coal power plants). Prishtina-the capital city of Kosovo-is heavily influenced too. Furthermore, the pollutants combined together with those from heavy traffic are dissolved in Prishtina runoff water, which is discharged into the creek entering the river Sitnica together with urban waste water. The available data show the complex pollution with excessive quantities of nitrites, suspended materials, organic compounds, detergents, heavy metals, polychlorinated biphenyls, etc. In this study, the cytotoxic and genotoxic potential of water samples taken at these sites was tested in primary rat hepatocytes. The results obtained indicate that water samples collected in Prishtina and Obiliq had a significant cytotoxic potential in primary rat hepatocyte cultures even when diluted to 1 %. The increased cytotoxicity, however, was not accompanied by an increased genotoxicity as measured by the percentage of micronucleated cells. Further investigations addressing the chemical composition of the samples and the identification of the toxicants responsible for the cytotoxic effects found will be carried out in a next step. PMID:27488194

  11. Relationship of land use to water quality in the Chesapeake Bay region. [water sampling and photomapping river basins

    NASA Technical Reports Server (NTRS)

    Correll, D. L.

    1978-01-01

    Both the proportions of the various land use categories present on each watershed and the specific management practices in use in each category affect the quality of runoff waters, and the water quality of the Bay. Several permanent and portable stations on various Maryland Rivers collect volume-integrated water samples. All samples are analyzed for a series of nutrient, particulate, bacterial, herbicide, and heavy metal parameters. Each basin is mapped with respect to land use by the analysis of low-elevation aerial photos. Analyses are verified and adjusted by ground truth surveys. Data are processed and stored in the Smithsonian Institution data bank. Land use categories being investigated include forests/old fields, pastureland, row crops, residential areas, upland swamps, and tidal marshes.

  12. Effect of enzyme concentration, addition of water and incubation time on increase in yield of starch from potato.

    PubMed

    Sit, Nandan; Agrawal, U S; Deka, Sankar C

    2014-05-01

    Enzymatic treatment process for starch extraction from potato was investigated using cellulase enzyme and compared with conventional process. The effects of three parameters, cellulase enzyme concentration, incubation time and addition of water were evaluated for increase in starch yield as compared to the conventional process i.e., without using enzyme. A two-level full factorial design was used to study the process. The results indicated that all the main parameters and their interactions are statistically significant. Enzyme concentration and incubation time had a positive effect on the increase in starch yield while addition of water had a negative effect. The increase in starch yield ranged from 1.9% at low enzyme concentration and incubation time and high addition of water to a maximum of 70% increase from conventional process in starch yield was achieved when enzyme concentration and incubation time were high and addition of water was low suggesting water present in the ground potato meal is sufficient for access to the enzyme with in the slurry ensuring adequate contact with the substrate. PMID:24803713

  13. Using SPMDs for monitoring hydrophobic organic compounds in urban river water in Korea compared with using conventional water grab samples

    USGS Publications Warehouse

    Kim, Un-Jung; Kim, Hee Young; Alvarez, David A.; Lee, In-Seok; Oh, Jeong-Eun

    2014-01-01

    We aimed to verify the effectiveness of semi-permeablemembrane devices (SPMDs) formonitoring hydrophobic organic compounds, such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), that are not easy to detect using conventional grab samples (because of their low concentrations), in water.We used SPMDs and grab samples to monitor PCBs and PBDEs upstream and downstream of a sewage treatment plant (STP) in the Suyeong River in Busan, Korea. Concentrations in three different phases (freely dissolved, apparently dissolved, and particulate) were measured, to investigate the aquatic fate of PCBs and PBDEs. The freely dissolved (SPMD) concentrations were 2–3 times higher than the apparently dissolved and particulate phase (grab sample) concentrations. No meaningful relationships were found between the total PCB and PBDE concentrations of the grab sample and SPMD sample because of the different partitioning behaviors and detection frequencies of the individual chemicals. However, the summed concentrations of specific PCB and PBDE congeners (that were abundant in all samples) in the grab and SPMD samples correlated well (r2 = 0.7451 for PCBs 28 + 52 + 153, r2 = 0.9987 for PBDEs 28 + 47 + 99). The PBDE concentrations measured using SPMDs decreased with increasing distance from the STP, but no apparent dilution effect was found in the grab samples. Our results show that SPMDs could be used to support grab sampling for specific chemicals, or to trace chemical sources (such as STPs) to the aquatic environment.

  14. Using SPMDs for monitoring hydrophobic organic compounds in urban river water in Korea compared with using conventional water grab samples.

    PubMed

    Kim, Un-Jung; Kim, Hee Young; Alvarez, David; Lee, In-Seok; Oh, Jeong-Eun

    2014-02-01

    We aimed to verify the effectiveness of semi-permeable membrane devices (SPMDs) for monitoring hydrophobic organic compounds, such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), that are not easy to detect using conventional grab samples (because of their low concentrations), in water. We used SPMDs and grab samples to monitor PCBs and PBDEs upstream and downstream of a sewage treatment plant (STP) in the Suyeong River in Busan, Korea. Concentrations in three different phases (freely dissolved, apparently dissolved, and particulate) were measured, to investigate the aquatic fate of PCBs and PBDEs. The freely dissolved (SPMD) concentrations were 2-3 times higher than the apparently dissolved and particulate phase (grab sample) concentrations. No meaningful relationships were found between the total PCB and PBDE concentrations of the grab sample and SPMD sample because of the different partitioning behaviors and detection frequencies of the individual chemicals. However, the summed concentrations of specific PCB and PBDE congeners (that were abundant in all samples) in the grab and SPMD samples correlated well (r(2)=0.7451 for PCBs 28+52+153, r(2)=0.9987 for PBDEs 28+47+99). The PBDE concentrations measured using SPMDs decreased with increasing distance from the STP, but no apparent dilution effect was found in the grab samples. Our results show that SPMDs could be used to support grab sampling for specific chemicals, or to trace chemical sources (such as STPs) to the aquatic environment. PMID:23845507

  15. Field guide for collecting and processing stream-water samples for the National Water-Quality Assessment Program

    USGS Publications Warehouse

    Shelton, Larry R.

    1994-01-01

    The U.S. Geological Survey's National Water-Quality Assessment program includes extensive data- collection efforts to assess the quality of the Nations's streams. These studies require analyses of stream samples for major ions, nutrients, sediments, and organic contaminants. For the information to be comparable among studies in different parts of the Nation, consistent procedures specifically designed to produce uncontaminated samples for trace analysis in the laboratory are critical. This field guide describes the standard procedures for collecting and processing samples for major ions, nutrients, organic contaminants, sediment, and field analyses of conductivity, pH, alkalinity, and dissolved oxygen. Samples are collected and processed using modified and newly designed equipment made of Teflon to avoid contamination, including nonmetallic samplers (D-77 and DH-81) and a Teflon sample splitter. Field solid-phase extraction procedures developed to process samples for organic constituent analyses produce an extracted sample with stabilized compounds for more accurate results. Improvements to standard operational procedures include the use of processing chambers and capsule filtering systems. A modified collecting and processing procedure for organic carbon is designed to avoid contamination from equipment cleaned with methanol. Quality assurance is maintained by strict collecting and processing procedures, replicate sampling, equipment blank samples, and a rigid cleaning procedure using detergent, hydrochloric acid, and methanol.

  16. Solid sampling determination of lithium and sodium additives in microsamples of yttrium oxyorthosilicate by high-resolution continuum source graphite furnace atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Laczai, Nikoletta; Kovács, László; Péter, Ágnes; Bencs, László

    2016-03-01

    Solid sampling high resolution continuum source graphite furnace atomic absorption spectrometry (SS-HR-CS-GFAAS) methods were developed and studied for the fast and sensitive quantitation of Li and Na additives in microsamples of cerium-doped yttrium oxyorthosilicate (Y2SiO5:Ce) scintillator materials. The methods were optimized for solid samples by studying a set of GFAAS conditions (i.e., the sample mass, sensitivity of the analytical lines, and graphite furnace heating programs). Powdered samples in the mass range of 0.099-0.422 mg were dispensed onto graphite sample insertion boats, weighed and analyzed. Pyrolysis and atomization temperatures were optimized by the use of single-element standard solutions of Li and Na (acidified with 0.144 mol/L HNO3) at the Li I 610.353 nm and Na I 285.3013 nm analytical lines. For calibration purposes, the method of standard addition with Li and Na solutions was applied. The correlation coefficients (R values) of the calibration graphs were not worse than 0.9678. The limit of detection for oxyorthosilicate samples was 20 μg/g and 80 μg/g for Li and Na, respectively. The alkaline content of the solid samples were found to be in the range of 0.89 and 8.4 mg/g, respectively. The accuracy of the results was verified by means of analyzing certified reference samples, using methods of standard (solution) addition calibration.

  17. Layered Double Hydroxide Nanoplatelets with Excellent Tribological Properties under High Contact Pressure as Water-Based Lubricant Additives

    PubMed Central

    Wang, Hongdong; Liu, Yuhong; Chen, Zhe; Wu, Bibo; Xu, Sailong; Luo, Jianbin

    2016-01-01

    High efficient and sustainable utilization of water-based lubricant is essential for saving energy. In this paper, a kind of layered double hydroxide (LDH) nanoplatelets is synthesized and well dispersed in water due to the surface modification with oleylamine. The excellent tribological properties of the oleylamine-modified Ni-Al LDH (NiAl-LDH/OAm) nanoplatelets as water-based lubricant additives are evaluated by the tribological tests in an aqueous environment. The modified LDH nanoplatelets are found to not only reduce the friction but also enhance the wear resistance, compared with the water-based cutting fluid and lubricants containing other particle additives. By adding 0.5 wt% LDH nanoplatelets, under 1.5 GPa initial contact pressure, the friction coefficient, scar diameter, depth and width of the wear track dramatically decrease by 83.1%, 43.2%, 88.5% and 59.5%, respectively. It is considered that the sufficiently small size and the excellent dispersion of NiAl-LDH/OAm nanoplatelets in water are the key factors, so as to make them enter the contact area, form a lubricating film and prevent direct collision of asperity peaks. Our investigations demonstrate that the LDH nanoplatelet as a water-based lubricant additive has a great potential value in industrial application. PMID:26951794

  18. Effect of water and nitrogen additions on free-living nitrogen fixer populations in desert grass root zones.

    PubMed Central

    Herman, R P; Provencio, K R; Torrez, R J; Seager, G M

    1993-01-01

    In this study we measured changes in population levels of free-living N2-fixing bacteria in the root zones of potted Bouteloua eriopoda and Sporobolus flexuosus plants as well as the photosynthetic indices of the plants in response to added nitrogen, added water, and added water plus nitrogen treatments. In addition, N2 fixer population changes in response to added carbon source and nitrogen were measured in plant-free soil columns. There were significant increases in the numbers of N2 fixers associated with both plant species in the water and the water plus nitrogen treatments. Both treatments increased the photosynthetic index, suggesting that plant exudates were driving N2 fixer population changes. Population increases were greatest in the water plus nitrogen treatments, indicating that added nitrogen was synergistic with added water and suggesting that nitrogen addition spared bacteria the metabolic cost of N2 fixation, allowing greater reproduction. Plant-free column studies demonstrated a synergistic carbon-nitrogen effect when carbon levels were limiting (low malate addition) but not when carbon was abundant (high malate), further supporting this hypothesis. The results of this study indicate the presence of N2 fixer populations which interact with plants and which may play a role in the nitrogen balance of desert grasslands. PMID:8215373

  19. Numerical study of water entry supercavitating flow around a vertical circular cylinder influenced by turbulent drag-reducing additives

    NASA Astrophysics Data System (ADS)

    Jiang, C. X.; Cheng, J. P.; Li, F. C.

    2015-01-01

    This paper attempts to introduce a numerical simulation procedure to simulate water-entry problems influenced by turbulent drag-reducing additives in a viscous incompressible medium. Firstly we performed a numerical investigation on water-entry supercavities in water and turbulent drag-reducing solution at the impact velocity of 28.4 m/s to confirm the accuracy of the numerical method. Based on the verification, projectile entering water and turbulent drag-reducing solution at relatively high velocity of 142.7 m/s (phase transition is considered) is simulated. The cross viscosity equation was adopted to represent the shear-thinning characteristic of aqueous solution of drag-reducing additives. The configuration and dynamic characteristics of water entry supercavity, flow resistance were discussed respectively. It was obtained that the numerical simulation results are in consistence with experimental data. Numerical results show that the supercavity length in drag-reducing solution is larger than one in water and the velocity attenuates faster at high velocity than at low velocity; the influence of drag-reducing solution is more obvious at high impact velocity. Turbulent drag-reducing additives have the great potential for enhancement of supercavity.

  20. Layered Double Hydroxide Nanoplatelets with Excellent Tribological Properties under High Contact Pressure as Water-Based Lubricant Additives.

    PubMed

    Wang, Hongdong; Liu, Yuhong; Chen, Zhe; Wu, Bibo; Xu, Sailong; Luo, Jianbin

    2016-01-01

    High efficient and sustainable utilization of water-based lubricant is essential for saving energy. In this paper, a kind of layered double hydroxide (LDH) nanoplatelets is synthesized and well dispersed in water due to the surface modification with oleylamine. The excellent tribological properties of the oleylamine-modified Ni-Al LDH (NiAl-LDH/OAm) nanoplatelets as water-based lubricant additives are evaluated by the tribological tests in an aqueous environment. The modified LDH nanoplatelets are found to not only reduce the friction but also enhance the wear resistance, compared with the water-based cutting fluid and lubricants containing other particle additives. By adding 0.5 wt% LDH nanoplatelets, under 1.5 GPa initial contact pressure, the friction coefficient, scar diameter, depth and width of the wear track dramatically decrease by 83.1%, 43.2%, 88.5% and 59.5%, respectively. It is considered that the sufficiently small size and the excellent dispersion of NiAl-LDH/OAm nanoplatelets in water are the key factors, so as to make them enter the contact area, form a lubricating film and prevent direct collision of asperity peaks. Our investigations demonstrate that the LDH nanoplatelet as a water-based lubricant additive has a great potential value in industrial application. PMID:26951794

  1. Layered Double Hydroxide Nanoplatelets with Excellent Tribological Properties under High Contact Pressure as Water-Based Lubricant Additives

    NASA Astrophysics Data System (ADS)

    Wang, Hongdong; Liu, Yuhong; Chen, Zhe; Wu, Bibo; Xu, Sailong; Luo, Jianbin

    2016-03-01

    High efficient and sustainable utilization of water-based lubricant is essential for saving energy. In this paper, a kind of layered double hydroxide (LDH) nanoplatelets is synthesized and well dispersed in water due to the surface modification with oleylamine. The excellent tribological properties of the oleylamine-modified Ni-Al LDH (NiAl-LDH/OAm) nanoplatelets as water-based lubricant additives are evaluated by the tribological tests in an aqueous environment. The modified LDH nanoplatelets are found to not only reduce the friction but also enhance the wear resistance, compared with the water-based cutting fluid and lubricants containing other particle additives. By adding 0.5 wt% LDH nanoplatelets, under 1.5 GPa initial contact pressure, the friction coefficient, scar diameter, depth and width of the wear track dramatically decrease by 83.1%, 43.2%, 88.5% and 59.5%, respectively. It is considered that the sufficiently small size and the excellent dispersion of NiAl-LDH/OAm nanoplatelets in water are the key factors, so as to make them enter the contact area, form a lubricating film and prevent direct collision of asperity peaks. Our investigations demonstrate that the LDH nanoplatelet as a water-based lubricant additive has a great potential value in industrial application.

  2. Geohydrology of the Central Oahu, Hawaii, Ground-Water Flow System and Numerical Simulation of the Effects of Additional Pumping

    USGS Publications Warehouse

    Oki, Delwyn S.

    1998-01-01

    -calculated freshwater-saltwater interface location for the future recharge and pumping conditions. Model results indicate that an additional 10 million gallons per day (beyond the 1995-allocated rates) of freshwater can potentially be developed from northern Oahu. Various distributions of pumping can be used to obtain the additional 10 million gallons per day of water. The quality of the water pumped will be dependent on site-specific factors and cannot be predicted on the basis of model results. If the additional 10 million gallons per day pumpage is restricted to the Kawailoa and Waialua areas, model results indicate that a regional drawdown (relative to the water-level distribution associated with the 1995-allocated pumping rates) of less than 0.6 foot can be maintained in these two areas. The additional pumping, however, would cause salinity increases in water pumped by existing deep wells. In addition, increases in salinity may occur at other wells in areas where the model indicates no significant problem with upconing.

  3. Water reuse: >90% water yield in MBR/RO through concentrate recycling and CO2 addition as scaling control.

    PubMed

    Joss, Adriano; Baenninger, Claudia; Foa, Paolo; Koepke, Stephan; Krauss, Martin; McArdell, Christa S; Rottermann, Karin; Wei, Yuansong; Zapata, Ana; Siegrist, Hansruedi

    2011-11-15

    Over 1.5 years continuous piloting of a municipal wastewater plant upgraded with a double membrane system (ca. 0.6 m(3) d(-1) of product water produced) have demonstrated the feasibility of achieving high water quality with a water yield of 90% by combining a membrane bioreactor (MBR) with a submerged ultrafiltration membrane followed by a reverse osmosis membrane (RO). The novelty of the proposed treatment scheme consists of the appropriate conditioning of MBR effluent prior to the RO and in recycling the RO concentrates back to the biological unit. All the 15 pharmaceuticals measured in the influent municipal sewage were retained below 100 ng L(-1), a proposed quality parameter, and mostly below detection limits of 10 ng L(-1). The mass balance of the micropollutants shows that these are either degraded or discharged with the excess concentrate, while only minor quantities were found in the excess sludge. The micropollutant load in the concentrate can be significantly reduced by ozonation. A low treated water salinity (<10 mM inorganic salts; 280 ± 70 μS cm(-1)) also confirms that the resulting product has a high water quality. Solids precipitation and inorganic scaling are effectively mitigated by lowering the pH in the RO feed water with CO(2) conditioning, while the concentrate from the RO is recycled to the biological unit where CO(2) is stripped by aeration. This causes precipitation to occur in the bioreactor bulk, where it is much less of a process issue. SiO(2) is the sole exception. Equilibrium modeling of precipitation reactions confirms the effectiveness of this scaling-mitigation approach for CaCO(3) precipitation, calcium phosphate and sulfate minerals. PMID:21959090

  4. Evaluation of water sampling methodologies for amplicon-based characterization of bacterial community structure.

    PubMed

    Staley, Christopher; Gould, Trevor J; Wang, Ping; Phillips, Jane; Cotner, James B; Sadowsky, Michael J

    2015-07-01

    Reduction in costs of next-generation sequencing technologies has allowed unprecedented characterization of bacterial communities from environmental samples including aquatic ecosystems. However, the extent to which extrinsic factors including sampling volume, sample replication, DNA extraction kits, and sequencing target affect the community structure inferred are poorly explored. Here, triplicate 1, 2, and 6L volume water samples from the Upper Mississippi River were processed to determine variation among replicates and sample volumes. Replicate variability significantly influenced differences in the community α-diversity (P=0.046), while volume significantly changed β-diversity (P=0.037). Differences in phylogenetic and taxonomic community structure differed both among triplicate samples and among the volumes filtered. Communities from 2L and 6L water samples showed similar clustering via discriminant analysis. To assess variation due to DNA extraction method, DNA was extracted from triplicate cell pellets from four sites along the Upper Mississippi River using the Epicentre Metagenomic DNA Isolation Kit for Water and MoBio PowerSoil kit. Operational taxonomic units representing ≤14% of sequence reads differed significantly among all sites and extraction kits used, although differences in diversity and community coverage were not significant (P≥0.057). Samples characterized using only the V6 region had significantly higher coverage and lower richness and α-diversity than those characterized using V4-V6 regions (P<0.001). Triplicate sampling of at least 2L of water provides robust representation of community variability, and these results indicate that DNA extraction kit and sequencing target displayed taxonomic biases that did not affect the overall biological conclusions drawn. PMID:25956022

  5. Passive nutrient addition for the biodegradation of ethylene glycol in storm water.

    PubMed

    Safferman, Steven I; Azar, Roger A; Sigler, Stephanie

    2002-01-01

    This laboratory proof-of-concept research examined the feasibility of adding solid, slow-release macronutrients to a biofilm reactor system to achieve the effective biodegradation of a predominately organic polluted storm water. The target scenario was treating ethylene glycol in storm water, representing the runoff of airport deicing and anti-icing fluids. However, the results can also be generalized for any water polluted with a predominately carbonaceous material. The use of a solid, slow-release nutrient source, compared to amending with a soluble solution in proportion to influent flow, would be ideal for storm water applications and other specialized wastewater flows when maintenance requirements and operational support must be minimized. Several commercially available fertilizers were preliminarily examined to determine which had the best potential to provide the required amount of nutrients. A time-released, polymer-coated granular fertilizer was ultimately selected. Based on laboratory studies, it was found that this fertilizer could provide a controllable source of macronutrients that enabled treatment to a similar degree as if the macronutrients had been dissolved in the influent. The only major operational problem was reduced nutrient delivery from the fertilizer after it became coated with a thick biofilm. However, the inherent intermittent nature of storm water production resulting in wet/dry cycles may minimize the development of a thick biofilm. PMID:12049128

  6. Atmospheric transport and deposition, an additional input pathway for triazine herbicides to surface waters

    SciTech Connect

    Muir, D.C.G.; Rawn, D.F.

    1996-10-01

    Although surface runoff from treated fields is regarded as the major route of entry of triazine herbicides to surface waters, other pathways such as deposition via precipitation, gas absorption and dryfall may also be important. Triazine herbicides have been detected in precipitation but there has been only a very limited amount of work on gas phase and aerosols. To examine the importance of atmospheric inputs concentrations of atrazine, cyanazine and terbuthylazine in gas phase/aerosols, precipitation, and surface waters were determined (along with other herbicides) using selected ion GC-MS. Atrazine was detected at low ng/L concentrations in surface waters (<0.04-5.3 ng/L) and precipitation (0.1-53 ng/L), and at 0.02-0.1 ng/m{sup 3} in air. Cyanazine and terbuthylazine were detected in air and infrequently in water. Highest atrazine concentrations in air were found during June each year on both gas phase and particles. Concentrations of atrazine in surface waters at both locations increased during June, even in the absence of precipitation or overland flow, presumably due to inputs from dryfall and to gas areas and boreal forest lakes due to transport and deposition. Ecological risk assessment of triazines, especially for pristine aquatic environments should include consideration of this atmospheric pathway.

  7. Direct determination of ammoniacal nitrogen in water samples using corona discharge ion mobility spectrometry.

    PubMed

    Jafari, M T; Khayamian, T

    2008-09-15

    In this study, direct determination of ammoniacal nitrogen residues in water samples using corona discharge ion mobility spectrometry (CD-IMS) was investigated. Pyridine was used as an alternate reagent gas to enhance selectivity and sensitivity of the method. The results indicate that the limit of detection (LOD) was about 9.2x10(-3)mugmL(-1) and the linear dynamic range was obtained from 0.03 to 2.00mugmL(-1). The relative standard deviation was about 11%. Furthermore, this method was successfully applied to the direct determination of ammoniacal nitrogen in river and tap water samples and the results were compared with the Nessler method. The comparison of the results validates the potential of the proposed method as an alternative technique for the analysis of the ammoniacal nitrogen in water samples. PMID:18761176

  8. A continuous water sampling and multi-parameter measurement system for estuaries

    USGS Publications Warehouse

    Schemel, Laurence E.; Dedini, Lee A.

    1979-01-01

    Salinity, temperature, light transmissivity, oxygen saturation, turbidity, pH, pCO2, and chlorophyll a fluorescence of a pumped water sample are continuously measured with a system designed primarily for estuarine studies. Near-surface water from a depth of 2 m is sampled continuously while the vessel is underway or water at depths to 100 m can be collected with an in situ pump, in which case the sampling depth and temperature are measured by an in situ probe. The system is comprised of commercially available instruments, equipment, and components, and of specialized items designed and fabricated by the authors. Data can be read from digital displays and analog strip-chart recorders. Tables and figures describing specialized items are included.

  9. Active Sampling Device for Determining Pollutants in Surface and Pore Water - the In Situ Sampler for Biphasic Water Monitoring.

    PubMed

    Supowit, Samuel D; Roll, Isaac B; Dang, Viet D; Kroll, Kevin J; Denslow, Nancy D; Halden, Rolf U

    2016-01-01

    We designed and evaluated an active sampling device, using as analytical targets a family of pesticides purported to contribute to honeybee colony collapse disorder. Simultaneous sampling of bulk water and pore water was accomplished using a low-flow, multi-channel pump to deliver water to an array of solid-phase extraction cartridges. Analytes were separated using either liquid or gas chromatography, and analysis was performed using tandem mass spectrometry (MS/MS). Achieved recoveries of fipronil and degradates in water spiked to nominal concentrations of 0.1, 1, and 10 ng/L ranged from 77 ± 12 to 110 ± 18%. Method detection limits (MDLs) were as low as 0.040-0.8 ng/L. Extraction and quantitation of total fiproles at a wastewater-receiving wetland yielded concentrations in surface water and pore water ranging from 9.9 ± 4.6 to 18.1 ± 4.6 ng/L and 9.1 ± 3.0 to 12.6 ± 2.1 ng/L, respectively. Detected concentrations were statistically indistinguishable from those determined by conventional, more laborious techniques (p > 0.2 for the three most abundant fiproles). Aside from offering time-averaged sampling capabilities for two phases simultaneously with picogram-per-liter MDLs, the novel methodology eliminates the need for water and sediment transport via in situ solid phase extraction. PMID:26905924

  10. Active Sampling Device for Determining Pollutants in Surface and Pore Water - the In Situ Sampler for Biphasic Water Monitoring

    NASA Astrophysics Data System (ADS)

    Supowit, Samuel D.; Roll, Isaac B.; Dang, Viet D.; Kroll, Kevin J.; Denslow, Nancy D.; Halden, Rolf U.

    2016-02-01

    We designed and evaluated an active sampling device, using as analytical targets a family of pesticides purported to contribute to honeybee colony collapse disorder. Simultaneous sampling of bulk water and pore water was accomplished using a low-flow, multi-channel pump to deliver water to an array of solid-phase extraction cartridges. Analytes were separated using either liquid or gas chromatography, and analysis was performed using tandem mass spectrometry (MS/MS). Achieved recoveries of fipronil and degradates in water spiked to nominal concentrations of 0.1, 1, and 10 ng/L ranged from 77 ± 12 to 110 ± 18%. Method detection limits (MDLs) were as low as 0.040-0.8 ng/L. Extraction and quantitation of total fiproles at a wastewater-receiving wetland yielded concentrations in surface water and pore water ranging from 9.9 ± 4.6 to 18.1 ± 4.6 ng/L and 9.1 ± 3.0 to 12.6 ± 2.1 ng/L, respectively. Detected concentrations were statistically indistinguishable from those determined by conventional, more laborious techniques (p > 0.2 for the three most abundant fiproles). Aside from offering time-averaged sampling capabilities for two phases simultaneously with picogram-per-liter MDLs, the novel methodology eliminates the need for water and sediment transport via in situ solid phase extraction.

  11. Active Sampling Device for Determining Pollutants in Surface and Pore Water – the In Situ Sampler for Biphasic Water Monitoring

    PubMed Central

    Supowit, Samuel D.; Roll, Isaac B.; Dang, Viet D.; Kroll, Kevin J.; Denslow, Nancy D.; Halden, Rolf U.

    2016-01-01

    We designed and evaluated an active sampling device, using as analytical targets a family of pesticides purported to contribute to honeybee colony collapse disorder. Simultaneous sampling of bulk water and pore water was accomplished using a low-flow, multi-channel pump to deliver water to an array of solid-phase extraction cartridges. Analytes were separated using either liquid or gas chromatography, and analysis was performed using tandem mass spectrometry (MS/MS). Achieved recoveries of fipronil and degradates in water spiked to nominal concentrations of 0.1, 1, and 10 ng/L ranged from 77 ± 12 to 110 ± 18%. Method detection limits (MDLs) were as low as 0.040–0.8 ng/L. Extraction and quantitation of total fiproles at a wastewater-receiving wetland yielded concentrations in surface water and pore water ranging from 9.9 ± 4.6 to 18.1 ± 4.6 ng/L and 9.1 ± 3.0 to 12.6 ± 2.1 ng/L, respectively. Detected concentrations were statistically indistinguishable from those determined by conventional, more laborious techniques (p > 0.2 for the three most abundant fiproles). Aside from offering time-averaged sampling capabilities for two phases simultaneously with picogram-per-liter MDLs, the novel methodology eliminates the need for water and sediment transport via in situ solid phase extraction. PMID:26905924

  12. Differential responses of short-term soil respiration dynamics to the experimental addition of nitrogen and water in the temperate semi-arid steppe of Inner Mongolia, China.

    PubMed

    Qi, Yuchun; Liu, Xinchao; Dong, Yunshe; Peng, Qin; He, Yating; Sun, Liangjie; Jia, Junqiang; Cao, Congcong

    2014-04-01

    We examined the effects of simulated rainfall and increasing N supply of different levels on CO2 pulse emission from typical Inner Mongolian steppe soil using the static opaque chamber technique, respectively in a dry June and a rainy August. The treatments included NH4NO3 additions at rates of 0, 5, 10, and 20 g N/(m(2)·year) with or without water. Immediately after the experimental simulated rainfall events, the CO2 effluxes in the watering plots without N addition (WCK) increased greatly and reached the maximum value at 2 hr. However, the efflux level reverted to the background level within 48 hr. The cumulative CO2 effluxes in the soil rang ed from 5.60 to 6.49 g C/m(2) over 48 hr after a single water application, thus showing an increase of approximately 148.64% and 48.36% in the effluxes during both observation periods. By contrast, the addition of different N levels without water addition did not result in a significant change in soil respiration in the short term. Two-way ANOVA showed that the effects of the interaction between water and N addition were insignificant in short-term soil CO2 effluxes in the soil. The cumulative soil CO2 fluxes of different treatments over 48 hr accounted for approximately 5.34% to 6.91% and 2.36% to 2.93% of annual C emission in both experimental periods. These results stress the need for improving the sampling frequency after rainfall in future studies to ensure more accurate evaluation of the grassland C emission contribution. PMID:25079414

  13. An Insoluble Copper(II) Acetylacetonate-Chiral Bipyridine Complex that Catalyzes Asymmetric Silyl Conjugate Addition in Water.

    PubMed

    Kitanosono, Taku; Zhu, Lei; Liu, Chang; Xu, Pengyu; Kobayashi, Shū

    2015-12-16

    Acicular purplish crystals were obtained from Cu(acac)2 and a chiral bipyridine ligand. Although the crystals were not soluble, they nevertheless catalyzed asymmetric silyl conjugate addition of lipophilic substrates in water. Indeed, the reactions proceeded efficiently only in water; they did not proceed well either in organic solvents or in mixed water/organic solvents in which the catalyst/substrates were soluble. This is in pronounced contrast to conventional organic reactions wherein the catalyst/substrates tend to be in solution. Several advantages of the chiral Cu(II) catalysis in water over previously reported catalyst systems have been demonstrated. Water is expected to play a prominent role in constructing and stabilizing sterically confined transition states and accelerating subsequent protonation to achieve high yields and enantioselectivities. PMID:26646601

  14. Electrofishing and the effects of depletion sampling on fish health: A review and recommendations for additional study

    USGS Publications Warehouse

    Panek, F.M.; Densmore, Christine L.

    2011-01-01

    Depletion sampling in combination with multiple-pass electrofishing is an important fisheries management tool for wadeable streams. This combination of techniques has been used routinely by federal and state fishery management agencies for several decades as a reliable means to obtain quantitative data on trout populations or to describe fish community structure. In this paper we review the effects of electrofishing on fish and discuss this within the context of depletion sampling and multiple exposures of fishes to electric fields. The multiple wave forms most commonly used in sampling (alternating current, direct current, and pulsed direct current) are discussed as well as electrofishing induced response, injury and physiological stress. Fish that survive electrofishing injuries are more likely to suffer short and long-term adverse effects to their behavior, health, growth, or reproduction. Of greatest concern are the native, non-target species that may be subjected to multiple electrical shocks during the course of a 3-pass depletion survey. These exposures and their effects on the non-target species warrant further study as do the overall effects of electrofishing on populations and community structure. 

  15. Trace analysis of semivolatile organic compounds in large volume samples of snow, lake water, and groundwater.

    PubMed

    Usenko, Sascha; Hageman, Kimberly J; Schmedding, Dave W; Wilson, Glenn R; Simonich, Staci L

    2005-08-15

    An analytical method was developed for the trace analysis of a wide range of semivolatile organic compounds (SOCs) in 50-L high-elevation snow and lake water samples. The method was validated for 75 SOCs from seven different chemical classes (polycyclic aromatic hydrocarbons, organochlorine pesticides, amides, triazines, polychlorinated biphenyls, thiocarbamates, and phosphorothioates) that covered a wide range of physical-chemical properties including 7 orders of magnitude of octanol-water partition coefficient (log K(ow) = 1.4-8.3). The SOCs were extracted using a hydrophobically and hydrophilically modified divinylbenzene solid-phase extraction device (modified Speedisk). The average analyte recovery from 50 L of reverse osmosis water, using the modified Speedisk, was 99% with an average relative standard deviation of 4.8%. Snow samples were collected from the field, melted, and extracted using the modified Speedisk and a poly(tetrafluoroethylene) remote sample adapter in the laboratory. Lake water was sampled, filtered, and extracted in situ using an Infiltrex 100 fitted with a 1-microm glass fiber filter to trap particulate matter and the modified Speedisk to trap dissolved SOCs. The extracts were analyzed by gas chromatographic mass spectrometry with electron impact ionization and electron capture negative ionization using isotope dilution and selective ion monitoring. Estimated method detection limits for snow and lake water ranged from 0.2 to 125 pg/L and 0.5-400 pg/L, respectively. U.S. historic and current-use pesticides were identified and quantified in snow and lake water samples collected from Rocky Mountain National Park, CO. The application of the analytical method to the analysis of SOCs in large-volume groundwater samples is also shown. PMID:16173557

  16. Field portable mobile phone based fluorescence microscopy for detection of Giardia lamblia cysts in water samples

    NASA Astrophysics Data System (ADS)

    Ceylan Koydemir, Hatice; Gorocs, Zoltan; McLeod, Euan; Tseng, Derek; Ozcan, Aydogan

    2015-03-01

    Giardia lamblia is a waterborne parasite that causes an intestinal infection, known as giardiasis, and it is found not only in countries with inadequate sanitation and unsafe water but also streams and lakes of developed countries. Simple, sensitive, and rapid detection of this pathogen is important for monitoring of drinking water. Here we present a cost-effective and field portable mobile-phone based fluorescence microscopy platform designed for automated detection of Giardia lamblia cysts in large volume water samples (i.e., 10 ml) to be used in low-resource field settings. This fluorescence microscope is integrated with a disposable water-sampling cassette, which is based on a flow-through porous polycarbonate membrane and provides a wide surface area for fluorescence imaging and enumeration of the captured Giardia cysts on the membrane. Water sample of interest, containing fluorescently labeled Giardia cysts, is introduced into the absorbent pads that are in contact with the membrane in the cassette by capillary action, which eliminates the need for electrically driven flow for sample processing. Our fluorescence microscope weighs ~170 grams in total and has all the components of a regular microscope, capable of detecting individual fluorescently labeled cysts under light-emitting-diode (LED) based excitation. Including all the sample preparation, labeling and imaging steps, the entire measurement takes less than one hour for a sample volume of 10 ml. This mobile phone based compact and cost-effective fluorescent imaging platform together with its machine learning based cyst counting interface is easy to use and can even work in resource limited and field settings for spatio-temporal monitoring of water quality.

  17. Detection by PCR of pathogenic protozoa in raw and drinkable water samples in Colombia.

    PubMed

    Triviño-Valencia, Jessica; Lora, Fabiana; Zuluaga, Juan David; Gomez-Marin, Jorge E

    2016-05-01

    We evaluated the presence of DNA of Giardia, Toxoplasma, and Cryptosporidium by PCR, and of Giardia and Cryptosporidium genera by immunofluorescence antibody test (IFAT), in water samples, before, during, and after plant treatment for drinkable water. We applied this method in 38 samples of 10 l of water taken from each of the water treatment steps and in 8 samples taken at home (only for Toxoplasma PCR) in Quindio region in Colombia. There were 8 positive samples for Cryptosporidium parvum (21 %), 4 for Cryptosporidium hominis (10.5 %), 27 for Toxoplasma gondii (58.6 %), 2 for Giardia duodenalis assemblage A (5.2 %), and 5 for G. duodenalis assemblage B (13.1 %). By IFAT, 23 % were positive for Giardia and 21 % for Cryptosporidium. An almost perfect agreement was found between IFAT and combined results of PCR, by Kappa composite proportion analysis. PCR positive samples were significantly more frequent in untreated raw water for C. parvum (p = 0.02). High mean of fecal coliforms, high pH values, and low mean of chlorine residuals were strongly correlated with PCR positivity for G. duodenalis assemblage B. High pH value was correlated with PCR positivity for C. parvum. Phylogenetic analysis of DNA sequences was possible, showing water and human clinical sequences for Toxoplasma within the same phylogenetic group for B1 repeated sequence. PCR assay is complementary to IFAT assay for monitoring of protozoa in raw and drinkable water, enabling species identification and to look for phylogenetic analysis in protozoa from human and environmental sources. PMID:26779921

  18. Classification and authentication of unknown water samples using machine learning algorithms.

    PubMed

    Kundu, Palash K; Panchariya, P C; Kundu, Madhusree

    2011-07-01

    This paper proposes the development of water sample classification and authentication, in real life which is based on machine learning algorithms. The proposed techniques used experimental measurements from a pulse voltametry method which is based on an electronic tongue (E-tongue) instrumentation system with silver and platinum electrodes. E-tongue include arrays of solid state ion sensors, transducers even of different types, data collectors and data analysis tools, all oriented to the classification of liquid samples and authentication of unknown liquid samples. The time series signal and the corresponding raw data represent the measurement from a multi-sensor system. The E-tongue system, implemented in a laboratory environment for 6 numbers of different ISI (Bureau of Indian standard) certified water samples (Aquafina, Bisleri, Kingfisher, Oasis, Dolphin, and McDowell) was the data source for developing two types of machine learning algorithms like classification and regression. A water data set consisting of 6 numbers of sample classes containing 4402 numbers of features were considered. A PCA (principal component analysis) based classification and authentication tool was developed in this study as the machine learning component of the E-tongue system. A proposed partial least squares (PLS) based classifier, which was dedicated as well; to authenticate a specific category of water sample evolved out as an integral part of the E-tongue instrumentation system. The developed PCA and PLS based E-tongue system emancipated an overall encouraging authentication percentage accuracy with their excellent performances for the aforesaid categories of water samples. PMID:21507400

  19. Quantitative Detection of Trace Malachite Green in Aquiculture Water Samples by Extractive Electrospray Ionization Mass Spectrometry

    PubMed Central

    Fang, Xiaowei; Yang, Shuiping; Chingin, Konstantin; Zhu, Liang; Zhang, Xinglei; Zhou, Zhiquan; Zhao, Zhanfeng

    2016-01-01

    Exposure to malachite green (MG) may pose great health risks to humans; thus, it is of prime importance to develop fast and robust methods to quantitatively screen the presence of malachite green in water. Herein the application of extractive electrospray ionization mass spectrometry (EESI-MS) has been extended to the trace detection of MG within lake water and aquiculture water, due to the intensive use of MG as a biocide in fisheries. This method has the advantage of obviating offline liquid-liquid extraction or tedious matrix separation prior to the measurement of malachite green in native aqueous medium. The experimental results indicate that the extrapolated detection limit for MG was ~3.8 μg·L−1 (S/N = 3) in lake water samples and ~0.5 μg·L−1 in ultrapure water under optimized experimental conditions. The signal intensity of MG showed good linearity over the concentration range of 10–1000 μg·L−1. Measurement of practical water samples fortified with MG at 0.01, 0.1 and 1.0 mg·L−1 gave a good validation of the established calibration curve. The average recoveries and relative standard deviation (RSD) of malachite green in lake water and Carassius carassius fish farm effluent water were 115% (6.64% RSD), 85.4% (9.17% RSD) and 96.0% (7.44% RSD), respectively. Overall, the established EESI-MS/MS method has been demonstrated suitable for sensitive and rapid (<2 min per sample) quantitative detection of malachite green in various aqueous media, indicating its potential for online real-time monitoring of real life samples. PMID:27529262

  20. Quantitative Detection of Trace Malachite Green in Aquiculture Water Samples by Extractive Electrospray Ionization Mass Spectrometry.

    PubMed

    Fang, Xiaowei; Yang, Shuiping; Chingin, Konstantin; Zhu, Liang; Zhang, Xinglei; Zhou, Zhiquan; Zhao, Zhanfeng

    2016-01-01

    Exposure to malachite green (MG) may pose great health risks to humans; thus, it is of prime importance to develop fast and robust methods to quantitatively screen the presence of malachite green in water. Herein the application of extractive electrospray ionization mass spectrometry (EESI-MS) has been extended to the trace detection of MG within lake water and aquiculture water, due to the intensive use of MG as a biocide in fisheries. This method has the advantage of obviating offline liquid-liquid extraction or tedious matrix separation prior to the measurement of malachite green in native aqueous medium. The experimental results indicate that the extrapolated detection limit for MG was ~3.8 μg·L(-1) (S/N = 3) in lake water samples and ~0.5 μg·L(-1) in ultrapure water under optimized experimental conditions. The signal intensity of MG showed good linearity over the concentration range of 10-1000 μg·L(-1). Measurement of practical water samples fortified with MG at 0.01, 0.1 and 1.0 mg·L(-1) gave a good validation of the established calibration curve. The average recoveries and relative standard deviation (RSD) of malachite green in lake water and Carassius carassius fish farm effluent water were 115% (6.64% RSD), 85.4% (9.17% RSD) and 96.0% (7.44% RSD), respectively. Overall, the established EESI-MS/MS method has been demonstrated suitable for sensitive and rapid (<2 min per sample) quantitative detection of malachite green in various aqueous media, indicating its potential for online real-time monitoring of real life samples. PMID:27529262

  1. Speciation analysis of mercury in water samples using dispersive liquid-liquid microextraction combined with high-performance liquid chromatography.

    PubMed

    Gao, Zhongben; Ma, Xiaoguo

    2011-09-19

    A novel approach for preconcentration and speciation analysis of trace amount of mercury from water samples was proposed by dispersive liquid-liquid microextraction (DLLME) coupled to high performance liquid chromatography with diode array detection (HPLC-DAD). Mercury species (Hg(2+), methylmercury (MeHg(+)) and phenylmercury (PhHg(+))) were complexed with dithizone (DZ) to form hydrophobic chelates and then extracted into the fine drops of extraction solvent dispersed in the aqueous sample by dispersive solvent. After extraction, the sedimented phase was analyzed by HPLC-DAD. Some important parameters affecting the DLLME such as extraction solvent and dispersive solvent type and volume, concentration of dithizone solution, sample pH, extraction time and salt effect were investigated. Ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMIM][PF(6)]) was found to be a suitable extractant for the chelates. Under the optimized conditions (extraction solvent: 70 μL of ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMIM][PF(6)]); dispersive solvent: 0.75 mL of methanol containing dithizone (0.02%, m/v); pH: 4; extraction time: 5 min; and without salt addition), the limits of detection for Hg(2+), MeHg(+) and PhHg(+) were 0.32, 0.96 and 1.91 μg L(-1) (SN(-1)=3) respectively, and the relative standard deviation (RSD) was between 4.1 and 7.3% (n=5). Three real water samples (tap water, river water and lake water) spiked with mercury species were detected by the developed method, and the relative recoveries obtained for Hg(2+), MeHg(+) and PhHg(+) were 89.6-101.3%, 85.6-102.0% and 81.3-97.6%, respectively. PMID:21819859

  2. Radon levels in drinking water and soil samples of Jodhpur and Nagaur districts of Rajasthan, India.

    PubMed

    Mittal, Sudhir; Rani, Asha; Mehra, Rohit

    2016-07-01

    Radon causes lung cancer when it is trapped inside the lungs. Therefore it is very important to analyze the radon concentration in water and soil samples. In the present investigation, water and soil samples collected from 20 different locations of Jodhpur and Nagaur districts of Northern Rajasthan, India have been studied by using RAD7. The measured radon concentration in water samples varies from 0.5 to 15Bql(-1). The observed values lie within the safe limit as set by UNSCEAR, 2008. The total annual effective dose due to radon in water corresponding to all studied locations has been found to be well within the safe limit of 0.1mSvy(-1) as recommended by World Health Organization (WHO, 2004) and European Council (EU, 1998). The measurements carried out on radon concentration in soil samples reveal a variation from 1750 to 9850Bqm(-3). These results explore that the water of Jodhpur and Nagaur districts is suitable for drinking purpose without posing any health hazard but soil hazards depend upon its permeability and radon concentration. PMID:27135605

  3. Rapid and specific SPRi detection of L. pneumophila in complex environmental water samples.

    PubMed

    Foudeh, Amir M; Trigui, Hana; Mendis, Nilmini; Faucher, Sebastien P; Veres, Teodor; Tabrizian, Maryam

    2015-07-01

    Legionellosis is a very devastating disease worldwide mainly due to unpredictable outbreaks in man-made water systems. Developing a highly specific and sensitive rapid detection system that detects only metabolically active bacteria is a main priority for water quality assessment. We previously developed a versatile technique for sensitive and specific detection of synthetic RNA. In the present work, we further investigated the performance of the developed biosensor for detection of Legionella pneumophila in complex environmental samples, particularly those containing protozoa. The specificity and sensitivity of the detection system were verified using total RNA extracted from L. pneumophila in spiked water co-cultured with amoebae. We demonstrated that the expression level of ribosomal RNA (rRNA) is extremely dependent on the environmental conditions. The presence of amoebae with L. pneumophila, especially in nutrition-deprived samples, increased the amount of L. pneumophila 15-fold after 1 week as measured through the expression of 16s rRNA. Using the developed surface plasmon resonance imaging (SPRi) detection method, we were also able to successfully detect L. pneumophila within 3 h, both in the presence and absence of amoebae in the complex environmental samples obtained from a cooling water tower. These findings suggest that the developed biosensing system is a viable method for rapid, real-time and effective detection not only for L. pneumophila in environmental samples but also to assess the risk associated with the use of water contaminated with other pathogens. PMID:25935681

  4. A Study of the Variability of Water Maser Emission in a Sample of Young Stellar Objects

    NASA Astrophysics Data System (ADS)

    Trinidad, M. A.; Rojas, V.; Plascencia, J. C.; Ricalde, A.; Curiel, S.; Rodríguez, L. F.

    We present results of water maser observations in a sample of young stellar objects. The observations were made using the Haystack 37 m antenna during a span of time of about eight months. The sample was selected to study the variability of the water maser emission in young sources with far-infrared luminosities between 260 and 2.5×10^4 L[sun]. The results are shown in a series of plots that allow the analysis of the variation of the maser emission and to discuss the global properties of the sample. The results show that in all the observed sources the water maser emission varies with time. Based on the observed variability, the sample shows two kinds of behavior. About half of the sources show large variations in the peak flux density of at least one feature (by more than an order of magnitude) in time spans between one and several months, while in all the sources there is more than one feature where the changes in peak flux density are smaller (by less than a factor of 10) but in similar time scales. Finally, the variability of the observed water maser emission does not show a clear periodicity pattern in time and we do not find a clear relationship between the luminosity of the sources and the water maser variability. >From a statistical point of view, the H[2]O maser variability can be described as due to small (10%) Gaussian fluctuations in the line opacity.

  5. Quantifying water and air redistribution in heterogeneous sand sample by neutron imaging

    NASA Astrophysics Data System (ADS)

    Šácha, Jan; Sobotková, Martina; Jelínková, Vladimíra; Sněhota, Michal; Vontobel, Peter; Hovind, Jan

    2014-05-01

    Significant temporal variation of quasi saturated hydraulic conductivity (Kqs) has been observed to date in number of infiltration experiments conducted mainly on heterogeneous soil of Cambisol. The change of quasi-saturated hydraulic conductivity cannot be precisely described by existing models. The Kqs variations has been recently attributed to a changing distribution of the entrapped air and water within the sample. It is expected that air is moved to the preferential pathway and acts as a barrier there. To support this assumption a ponded infiltration experiment was conducted on a soil sample packed into the quartz glass column of inner diameter of 34 mm. The sample composition represents simplified heterogeneity of the natural soil but also allow the easy quantitative water content determination in individual subdomains of the sample. The matrix formed by a fine sand was surrounded with regions of coarse sand representing preferential flow pathways. The Kqs was determined from the known hydraulic gradient and measured volume flux. The experiment was monitored by neutron radiography. Volume of water in the sample calculated from neutron projections matched very well with actually infiltrated volume in the sample during first 40 second after beginning of infiltration. From the acquired radiographic images the 3D tomography images were reconstructed to obtain the spatial distribution of the water content within the sample. Difference between water volume calculated from radiography and tomography images was no more than 5%. While the total amount of water determined by NR within the sample during the quasi steady state flow remains practically constant (27.9 cm3 at the beginning and 28.6 cm3 on the end of infiltration) the water content in the coarse fraction decreases (from 0.333 to 0.324) and the water content in the fine fraction increases (from 0.414 to 0.436) in 5 hours. Similarly to previous experiments performed on natural Cambisols, the results support

  6. Assessing the effects of sampling design on water quality status classification

    NASA Astrophysics Data System (ADS)

    Lloyd, Charlotte; Freer, Jim; Johnes, Penny; Collins, Adrian

    2013-04-01

    The Water Framework Directive (WFD) requires continued reporting of the water quality status of all European waterbodies, with this status partly determined by the time a waterbody exceeds different pollution concentration thresholds. Routine water quality monitoring most commonly takes place at weekly to monthly time steps meaning that potentially important pollution events can be missed. This has the potential to result in the misclassification of water quality status. Against this context, this paper investigates the implications of sampling design on a range of existing water quality status metrics routinely applied to WFD compliance assessments. Previous research has investigated the effect of sampling design on the calculation of annual nutrient and sediment loads using a variety of different interpolation and extrapolation models. This work builds on this foundation, extending the analysis to include the effects of sampling regime on flow- and concentration-duration curves as well as threshold-exceedance statistics, which form an essential part of WFD reporting. The effects of sampling regime on both the magnitude of the summary metrics and their corresponding uncertainties are investigated. This analysis is being undertaken on data collected as part of the Hampshire Avon Demonstration Test Catchment (DTC) project; a DEFRA funded initiative investigating cost-effective solutions for reducing diffuse pollution from agriculture. The DTC monitoring platform is collecting water quality data at a variety of temporal resolutions and using differing collection methods, including weekly grab samples, daily ISCO autosamples and high resolution samples (15-30 min time step) using analysers in situ on the river bank. Datasets collected during 2011-2013 were used to construct flow- and concentration-duration curves. A bootstrapping methodology was employed to resample randomly the individual datasets and produce distributions of the curves in order to quantify the

  7. Development of an electrolysis system for tritium enrichment in superficial water samples.

    PubMed

    Garbarino, G; Magnoni, M; Bertino, S; Losana, M C

    2009-12-01

    Tritium present in the environment gradually decreased in the last decades and nowadays it has reached extremely low activity concentrations. The purpose of the present work is the implementation of a tritium enrichment system in water samples using electrolytic techniques and pure nickel and iron electrodes. In the present work a mean tritium enrichment factor of 13.0 +/- 3.2 was obtained. This result should allow to reach a minimum detectable activity of tritium in water samples of about 1 tritium unit (TU) or less. The present enrichment system necessitates further adjustments and improvements, such as a cooling system in order to reduce the tritium losses due to evaporation. PMID:19864330

  8. Glufosinate ammonium clean-up procedure from water samples using SPE

    NASA Astrophysics Data System (ADS)

    Tayeb M., A.; Ismail B., S.; Mardiana-Jansar, K.; Ta, Goh Choo; Agustar, Hani Kartini

    2015-09-01

    For the determination of glufosinate ammonium residue in soil and water samples, different solid phase extraction (SPE) sorbent efficiency was studied. Four different SPE sorbents i.e.: CROMABOND PS-H+, CROMABOND PS-OH-, ISOLUTE ENV+, Water Sep-Pak and OASIS HLB were used. Sample clean-up performance was evaluated using high performance liquid chromatography (Agilent 1220 infinity LC) with fluorescence detector. Detection of FMO-derivatives was done at λ ex = 260 nm and λ em= 310 nm. OASIS HLB column was the most suitable for the clean-up in view of the overall feasibility of the analysis.

  9. A chemodynamic approach for estimating losses of target organic chemicals from water during sample holding time

    USGS Publications Warehouse

    Capel, P.D.; Larson, S.J.

    1995-01-01

    Minimizing the loss of target organic chemicals from environmental water samples between the time of sample collection and isolation is important to the integrity of an investigation. During this sample holding time, there is a potential for analyte loss through volatilization from the water to the headspace, sorption to the walls and cap of the sample bottle; and transformation through biotic and/or abiotic reactions. This paper presents a chemodynamic-based, generalized approach to estimate the most probable loss processes for individual target organic chemicals. The basic premise is that the investigator must know which loss process(es) are important for a particular analyte, based on its chemodynamic properties, when choosing the appropriate method(s) to prevent loss.

  10. UMTRA project water sampling and analysis plan, Falls City, Texas. Revision 1

    SciTech Connect

    1995-09-01

    Planned, routine ground water sampling activities at the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project site near Falls City, Texas, are described in this water sampling and analysis plan (WSAP). The following plan identifies and justifies the sampling locations, analytical parameters, and sampling frequency for the routine monitoring stations at the site. The ground water data are used for site characterization and risk assessment. The regulatory basis for routine ground water monitoring at UMTRA Project sites is derived from the US Environmental Protection Agency (EPA) regulations in 40 CFR Part 192. Sampling procedures are guided by the UMTRA Project standard operating procedures (SOP) (JEG, n.d.), the Technical Approach Document (TAD) (DOE, 1989), and the most effective technical approach for the site. The Falls City site is in Karnes County, Texas, approximately 8 miles [13 kilometers southwest of the town of Falls City and 46 mi (74 km) southeast of San Antonio, Texas. Before surface remedial action, the tailings site consisted of two parcels. Parcel A consisted of the mill site, one mill building, five tailings piles, and one tailings pond south of Farm-to-Market (FM) Road 1344 and west of FM 791. A sixth tailings pile designated Parcel B was north of FM 791 and east of FM 1344.

  11. Analyses of native water, bottom material, and elutriate samples of southern Louisiana waterways, 1977-78

    USGS Publications Warehouse

    Dupuy, Alton J.; Couvillion, Nolan P.

    1979-01-01

    From March 1977 to July 1978 the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers conducted a series of elutriate studies to determine water quality in selected reaches of major navigable waterways of southern Louisiana. Sample were collected from the Mississippi River-Gulf Outlet areas; Mississippi River, South Pass; Baptiste Collette Bayou; Tiger Pass area; Baou Long; Bayou Barataria and Barataria Bay Waterway area (gulf section); Bayou Segnette Waterway, Lake Pontchartrain near Tangipahoa River mouth; Bayou Grand Caillou; Bayou la Carpe at Homa; Houma Navigation Canal and Terrebonne Bay; Bayou Boeuf, Bayou Chene, and Baou Black, Atchafalaya River Channel, Atchafalaya Bay; Old River Lock tailbay; Red River below mouth of Black River; Freshwaer Canal; Mermentau River and Lake Arthur Mermentau River outlet; and Calcasieu Ship Channel. The studies were initiated at the request of the U.S. Army Corps of Engineers to evaluate possible environmental effects of proposed dredging activities in those waterways. The U.S. Army Corps of Engineers and U.S. Geological Survey collected 189 samples of native water and 172 samples of bottom (bed) material from 163 different sites. A total of 117 elutriates (Mixtures of native water and bottom material) were prepared. The native water and elutriate samples were analyzed for selected metals, pesticides, nutrients organics, and pysical constituents. Particle-size determinations were made on bottom-material samples. (Kosco-USGS)

  12. Set Up of an Automatic Water Quality Sampling System in Irrigation Agriculture

    NASA Astrophysics Data System (ADS)

    Heinz, Emanuel; Kraft, Philipp; Buchen, Caroline; Frede, Hans-Georg; Aquino, Eugenio; Breuer, Lutz

    2014-05-01

    Climate change has already a large impact on the availability of water resources. Many regions in South-East Asia are assumed to receive less water in the future, dramatically impacting the production of the most important staple food: rice (Oryza sativa L.). Rice is the primary food source for nearly half of the World's population, and is the only cereal that can grow under wetland conditions. Especially anaerobic (flooded) rice fields require high amounts of water but also have higher yields than aerobic produced rice. In the past different methods were developed to reduce the water use in rice paddies, like alternative wetting and drying or the use of mixed cropping systems with aerobic (non-flooded) rice and alternative crops such as maize. A more detailed understanding of water and nutrient cycling in rice-based cropping systems is needed to reduce water use, and requires the investigation of hydrological and biochemical processes as well as transport dynamics at the field scale. New developments in analytical devices permit monitoring parameters at high temporal resolutions and at acceptable costs without much necessary maintenance or analysis over longer periods. Here we present a new type of automatic sampling set-up that facilitates in situ analysis of hydrometric information, stable water isotopes and nitrate concentrations in spatially differentiated agricultural fields. The system facilitates concurrent monitoring of a large number of water and nutrient fluxes (ground, surface, irrigation and rain water) in irrigated agriculture. For this purpose we couple an automatic sampling system with a Wavelength-Scanned Cavity Ring Down Spectrometry System (WS-CRDS) for stable water isotope analysis (δ2H and δ18O), a reagentless hyperspectral UV photometer for monitoring nitrate content and various water level sensors for hydrometric information. The whole system is maintained with special developed software for remote control of the system via internet. We

  13. Hydrochemical reactions and origin of offshore relatively fresh pore water from core samples in Hong Kong

    NASA Astrophysics Data System (ADS)

    Kwong, Hiu Tung; Jiao, Jiu Jimmy

    2016-06-01

    The existence of relatively fresh pore water offshore has been well recognised over the globe but studies on the chemistry of the pore water from offshore geological formations are extremely limited. This study aims to characterize the hydrochemistry of the submarine groundwater body in Hong Kong. It looks into the major ion concentrations and the stable isotopic compositions of pore water extracted from core samples from an offshore 42.30-m vibrocore in the southwestern Hong Kong waters. A minimum Cl- level of about one-third of that in typical seawater was noted in the terrestrial sediments, suggesting the presence of offshore relatively fresh water. Unexpectedly high NH4+ levels are attributed to organic matter decomposition in the terrestrial sediments. The leaching of shells due to exposure of marine sediments at sea-level low stands raises the Mg2+ and Ca2+ concentrations. Base Exchange Indices show weak cation exchange reactions in which Na+ and K+ are released while Mg2+ and Ca2+ are adsorbed. Isotopic compositions of pore water reveal that the low-salinity water is probably the relic water sequestered in fluvial systems during relative sea-level low stands. Cores properly stored in a freezer for a long time has been used to study the pore water chemistry. For the first time, this study introduces an approach to correct the measured data by considering the possible evaporation effect during the transportation and storage of the samples. Corrections for evaporation were applied to the major ion concentrations and the stable isotopic compositions of pore water measured. It is found that the corrections determined by the Cl- mass balance approach are more reliable. The corrected measurements give more reasonable observations and hence allow sensible conclusions on the hydrochemical reactions and the origin of pore water.

  14. Optimizing stream water mercury sampling for calculation of fish bioaccumulation factors.

    PubMed

    Riva-Murray, Karen; Bradley, Paul M; Scudder Eikenberry, Barbara C; Knightes, Christopher D; Journey, Celeste A; Brigham, Mark E; Button, Daniel T

    2013-06-01

    Mercury (Hg) bioaccumulation factors (BAFs) for game fishes are widely employed for monitoring, assessment, and regulatory purposes. Mercury BAFs are calculated as the fish Hg concentration (Hg(fish)) divided by the water Hg concentration (Hg(water)) and, consequently, are sensitive to sampling and analysis artifacts for fish and water. We evaluated the influence of water sample timing, filtration, and mercury species on the modeled relation between game fish and water mercury concentrations across 11 streams and rivers in five states in order to identify optimum Hg(water) sampling approaches. Each model included fish trophic position, to account for a wide range of species collected among sites, and flow-weighted Hg(water) estimates. Models were evaluated for parsimony, using Akaike's Information Criterion. Better models included filtered water methylmercury (FMeHg) or unfiltered water methylmercury (UMeHg), whereas filtered total mercury did not meet parsimony requirements. Models including mean annual FMeHg were superior to those with mean FMeHg calculated over shorter time periods throughout the year. FMeHg models including metrics of high concentrations (80th percentile and above) observed during the year performed better, in general. These higher concentrations occurred most often during the growing season at all sites. Streamflow was significantly related to the probability of achieving higher concentrations during the growing season at six sites, but the direction of influence varied among sites. These findings indicate that streamwater Hg collection can be optimized by evaluating site-specific FMeHg-UMeHg relations, intra-annual temporal variation in their concentrations, and streamflow-Hg dynamics. PMID:23668662

  15. Physicochemical transformation and algal toxicity of engineered nanoparticles in surface water samples.

    PubMed

    Zhang, Luqing; Li, Jingyi; Yang, Kun; Liu, Jingfu; Lin, Daohui

    2016-04-01

    Most studies on the behavior and toxicity of engineered nanoparticles (NPs) have been conducted in artificial water with well-controlled conditions, which are dramatically different from natural waters with complex compositions. To better understand the fate and toxicity of NPs in the natural water environment, physicochemical transformations of four NPs (TiO2, ZnO, Ag, and carbon nanotubes (CNTs)) and their toxicities towards a unicellular green alga (Chlorella pyrenoidosa) in four fresh water and one seawater sample were investigated. Results indicated that water chemistry had profound effects on aggregation, dissolution, and algal toxicity of the NPs. The strongest homoaggregation of the NPs was associated with the highest ionic strength, but no obvious correlation was observed between the homoaggregation of NPs and pH or dissolved organic matter content of the water samples. The greatest dissolution of ZnO NPs also occurred in seawater with the highest ionic strength, while the dissolution of Ag NPs varied differently from ZnO NPs. The released Zn(2+) and especially Ag(+) mainly accounted for the algal toxicity of ZnO and Ag NPs, respectively. The NP-cell heteroagglomeration occurred generally for CNTs and Ag NPs, which contributed to the observed nanotoxicity. However, there was no significant correlation between the observed nanotoxicity and the type of NP or the water chemistry. It was thus concluded that the physicochemical transformations and algal toxicities of NPs in the natural water samples were caused by the combined effects of complex water quality parameters rather than any single influencing factor alone. These results will increase our knowledge on the fate and effects of NPs in the aquatic environment. PMID:26745398

  16. Quantitative analysis of fuel-related hydrocarbons in surface water and wastewater samples by solid-phase microextraction.

    PubMed

    Langenfeld, J J; Hawthorne, S B; Miller, D J

    1996-01-01

    Solid-phase microextraction (SPME) parameters were examined on water contaminated with hydrocarbons including benzene and alkylbenzenes, n-alkanes, and polycyclic aromatic hydrocarbons (PAHs). Absorption equilibration times ranged from several minutes for low molecular weight compounds such as benzene to 5 h for high molecular weight compounds such as benzo[a]pyrene. Under equilibrium conditions, SPME analysis with GC/FID was linear over 3-6 orders of magnitude, with linear correlation coefficients (r(2)) greater than 0.96. Experimentally determined FID detection limits ranged from ∼30 ppt (w/w hydrocarbon/sample water) for high molecular weight PAHs (e.g., MW > 202) to ∼1 ppb for low molecular weight aromatic hydrocarbons. Experimental distribution constants (K) were different with 100- and 7-μm poly(dimethylsiloxane) fibers, and poor correlations with previously published values suggest that K depends on the fiber coating thickness and the sorbent preparation method. The sensitivity of SPME analysis is not significantly enhanced by larger sample volumes, since increasing the water volume (e.g., from 1 to 100 mL) has little effect on the number of analyte molecules absorbed by the fiber, especially for compounds with K < 500. Water sample storage should utilize silanized glassware, since hydrocarbon losses up to 70% could be attributed to unsilanized glassware walls when samples were stored for 48 h. Hydrocarbon losses at part-per-billion concentrations also occurred with surface waters due to partitioning onto part-per-thousand concentrations of suspended solids. Quantitative determinations of aromatic and aliphatic hydrocarbons (e.g., in gasoline-contaminated water) can be performed using GC/MS with deuterated internal standard or standard addition calibration as long as the target components or standards had unique ions for quantitation or sufficient chromatographic resolution from interferences. SPME analysis gave good quantitative performance with

  17. Triangle area water supply monitoring project, October 1988 through September 2001, North Carolina -- description of the water-quality network, sampling and analysis methods, and quality-assurance practices

    USGS Publications Warehouse

    Oblinger, Carolyn J.

    2004-01-01

    The Triangle Area Water Supply Monitoring Project was initiated in October 1988 to provide long-term water-quality data for six area water-supply reservoirs and their tributaries. In addition, the project provides data that can be used to determine the effectiveness of large-scale changes in water-resource management practices, document differences in water quality among water-supply types (large multiuse reservoir, small reservoir, run-of-river), and tributary-loading and in-lake data for water-quality modeling of Falls and Jordan Lakes. By September 2001, the project had progressed in four phases and included as many as 34 sites (in 1991). Most sites were sampled and analyzed by the U.S. Geological Survey. Some sites were already a part of the North Carolina Division of Water Quality statewide ambient water-quality monitoring network and were sampled by the Division of Water Quality. The network has provided data on streamflow, physical properties, and concentrations of nutrients, major ions, metals, trace elements, chlorophyll, total organic carbon, suspended sediment, and selected synthetic organic compounds. Project quality-assurance activities include written procedures for sample collection, record management and archive, collection of field quality-control samples (blank samples and replicate samples), and monitoring the quality of field supplies. In addition to project quality-assurance activities, the quality of laboratory analyses was assessed through laboratory quality-assurance practices and an independent laboratory quality-control assessment provided by the U.S. Geological Survey Branch of Quality Systems through the Blind Inorganic Sample Project and the Organic Blind Sample Project.

  18. Field determination of trace iron in fresh water samples by visual and spectrophotometric methods.

    PubMed

    Kawakubo, Susumu; Naito, Ayako; Fujihara, Asuka; Iwatsuki, Masaki

    2004-08-01

    Sensitive visual and micro spectrophotometric methods have been developed for field determination of trace iron in fresh water samples. For the visual method, a water sample (0.45-microm filtrate acidified to 0.1 M HCl) was placed in a glass vial and mixed with a reagent solution containing 1,10-phenanthroline, sodium thiocyanate and 0.1 M HCl. Iron was extracted as pink ferroin thiocyanate with 1 ml of 4-methy-2-pentanone. The sample up to 20 ml was added step-by-step, until the color of the extract was detected visually. Without any special instrument or color standard, iron down to 0.001 mg 1(-1) (0.025 microg) in a sample can be determined with an error of 20% in the field. For the micro spectrophotometric method, the extract for 20 ml of sample was separated by capillary suction in a column (micro pipette chip) with acrylic fibers. A part of the extract was pushed out into a micro cell for the absorbance measurement at 525 nm. The column was re-usable after washing with ethanol. This method had a detection limit of 0.001 mg 1(-1) and allowed determinations within an error of 5%. The proposed methods were applied to deionized-, tap-, river-, lake- and reservoir-water samples. PMID:15352504

  19. Solvent-assisted dispersive solid-phase extraction: A sample preparation method for trace detection of diazinon in urine and environmental water samples.

    PubMed

    Aladaghlo, Zolfaghar; Fakhari, Alireza; Behbahani, Mohammad

    2016-09-01

    In this research, a sample preparation method termed solvent-assisted dispersive solid-phase extraction (SA-DSPE) was applied. The used sample preparation method was based on the dispersion of the sorbent into the aqueous sample to maximize the interaction surface. In this approach, the dispersion of the sorbent at a very low milligram level was received by inserting a solution of the sorbent and disperser solvent into the aqueous sample. The cloudy solution created from the dispersion of the sorbent in the bulk aqueous sample. After pre-concentration of the diazinon, the cloudy solution was centrifuged and diazinon in the sediment phase dissolved in ethanol and determined by gas chromatography-flame ionization detector. Under the optimized conditions (pH of solution=7.0, Sorbent: benzophenone, 2%, Disperser solvent: ethanol, 500μL, Centrifuge: centrifuged at 4000rpm for 3min), the method detection limit for diazinon was 0.2, 0.3, 0.3 and 0.3μgL(-1) for distilled water, lake water, waste water and urine sample, respectively. Furthermore, the pre-concentration factor was 363.8, 356.1, 360.7 and 353.38 in distilled water, waste water, lake water and urine sample, respectively. SA-DSPE was successfully used for trace monitoring of diazinon in urine, lake and waste water samples. PMID:27495366

  20. Umbrella sampling of proton transfer in a creatine-water system

    NASA Astrophysics Data System (ADS)

    Ivchenko, Olga; Bachert, Peter; Imhof, Petra

    2014-04-01

    Proton transfer reactions are among the most common processes in chemistry and biology. Proton transfer between creatine and surrounding solvent water is underlying the chemical exchange saturation transfer used as a contrast in magnetic resonance imaging. The free energy barrier, determined by first-principles umbrella sampling simulations (EaDFT 3 kcal/mol) is in the same order of magnitude as the experimentally obtained activation energy. The underlying mechanism is a first proton transfer from the guanidinium group to the water pool, followed by a second transition where a proton is "transferred back" from the nearest water molecule to the deprotonated nitrogen atom of creatine.

  1. Nonylphenol ethoxylates and other additives in aircraft deicers, antiicers, and waters receiving airport runoff.

    PubMed

    Corsi, Steven R; Zitomer, Daniel H; Field, Jennifer A; Cancilla, Devon A

    2003-09-15

    Samples of nine different formulations of aircraft deicer and antiicer fluids (ADAF) were screened for the presence of selected surfactants. Nonylphenol ethoxylates (NPnEO) were identified in three ADAF formulations, octylphenol ethoxylates were identified in two formulations, and six formulations contained alcohol ethoxylates. A preliminary field study was conducted at General Mitchell International Airport, Milwaukee, WI, to quantify NPnEO (n = 1-15) and one of its byproducts, nonylphenol (NP), in airport runoff. Samples were collected from two airport outfalls, from the receiving stream, and from an upstream reference site during intensive ADAF application events. NPnEO was measured at concentrations up to 1190microg/L in airport outfall samples, up to 77 ug/L in samples from the receiving stream and less than 5.0 microg/L from the upstream reference. Concentrations of glycol and other ADAF-related constituents, including NPnEO, were reduced by approximately 1 order of magnitude between the outfall sites and the receiving stream site; however, concentrations of NP in the receiving stream remained similar to those from the outfalls (< 0.04 microg/L at the upstream reference, 0.98 and 7.67 microg/L at outfalls, and 3.89 microg/L in the receiving stream). The field data suggest that NP is generated through degradation of NPnEO from airport runoff. PMID:14524432

  2. Nonylphenol ethoxylates and other additives in aircraft deicers, antiicers, and waters receiving airport runoff

    USGS Publications Warehouse

    Corsi, Steven R.; Zitomer, Daniel H.; Field, Jennifer A.; Cancilla, Devon A.

    2003-01-01

    Samples of nine different formulations of aircraft deicer and antiicer fluids (ADAF) were screened for the presence of selected surfactants. Nonylphenol ethoxylates (NPnEO) were identified in three ADAF formulations, octylphenol ethoxylates were identified in two formulations, and six formulations contained alcohol ethoxylates. A preliminary field study was conducted at General Mitchell International Airport, Milwaukee, WI, to quantify NPnEO (n = 1-15) and one of its byproducts, nonylphenol (NP), in airport runoff. Samples were collected from two airport outfalls, from the receiving stream, and from an upstream reference site during intensive ADAF application events. NPnEO was measured at concentrations up to 1190microg/L in airport outfall samples, up to 77 ug/L in samples from the receiving stream and less than 5.0 microg/L from the upstream reference. Concentrations of glycol and other ADAF-related constituents, including NPnEO, were reduced by approximately 1 order of magnitude between the outfall sites and the receiving stream site; however, concentrations of NP in the receiving stream remained similar to those from the outfalls (< 0.04 microg/L at the upstream reference, 0.98 and 7.67 microg/L at outfalls, and 3.89 microg/L in the receiving stream). The field data suggest that NP is generated through degradation of NPnEO from airport runoff.

  3. The impact of sampling regime on the accuracy of water quality status classifications under the Water Framework Directive

    NASA Astrophysics Data System (ADS)

    Halliday, Sarah; Wade, Andrew; Skeffington, Richard; Bowes, Mike; Gozzard, Emma; Palmer-Felgate, Elizabeth; Newman, Johnathan; Jarvie, Helen; Loewenthal, Matt

    2014-05-01

    By 2015, EU regulatory agencies have a statutory obligation to meet the EU Water Framework Directive (WFD) target of "good ecological status" in all relevant inland and coastal waters. A significant amount of work is being undertaken to refine and improve the UK WFD water quality targets so that they better relate to the ecological status of a system. In 2013 new phosphorus (P) targets have been set, stipulating required lower mean annual "reactive" P concentrations, and recommendations published for more stringent pH, dissolved oxygen and ammonia targets. Despite this work, there are no guidelines on the sampling regime which should be employed to ensure compliance as part of the WFD classification system. Without guidance on how WFD water quality assessments should be done, regulatory agencies are at risk of misclassifying a system and of failing to identify systems which are ecologically at risk. Water quality is normally evaluated using routine monitoring programmes which use water samples collected, typically, at monthly intervals. However, new technologies are now allowing the collection of high-frequency (sub-daily) measurements of a range of water quality parameters which are revolutionising our understanding of freshwater nutrient cycling dynamics and the processes which control them. High-frequency and weekly water quality datasets for two lowland UK catchments, the River Enborne and The Cut, have been analysed to assess the impact of sampling frequency on the accuracy of WFD status classification. The Enborne is a rural catchment, impacted by agricultural runoff and sewage treatment works (STWs) discharges, and The Cut is a highly urbanised system significantly affected by STW discharges. On the Enborne, total reactive P (TRP) was measured hourly and soluble reactive P (SRP) measured weekly. Under the new WFD targets, although the mean annual P concentrations were similar, 0.173 and 0.136 mg/l-P for TRP and SRP respectively, the two "reactive" P

  4. Robowell: An automated process for monitoring ground water quality using established sampling protocols

    USGS Publications Warehouse

    Granato, G.E.; Smith, K.P.

    1999-01-01

    Robowell is an automated process for monitoring selected ground water quality properties and constituents by pumping a well or multilevel sampler. Robowell was developed and tested to provide a cost-effective monitoring system that meets protocols expected for manual sampling. The process uses commercially available electronics, instrumentation, and hardware, so it can be configured to monitor ground water quality using the equipment, purge protocol, and monitoring well design most appropriate for the monitoring site and the contaminants of interest. A Robowell prototype was installed on a sewage treatment plant infiltration bed that overlies a well-studied unconfined sand and gravel aquifer at the Massachusetts Military Reservation, Cape Cod, Massachusetts, during a time when two distinct plumes of constituents were released. The prototype was operated from May 10 to November 13, 1996, and quality-assurance/quality-control measurements demonstrated that the data obtained by the automated method was equivalent to data obtained by manual sampling methods using the same sampling protocols. Water level, specific conductance, pH, water temperature, dissolved oxygen, and dissolved ammonium were monitored by the prototype as the wells were purged according to U.S Geological Survey (USGS) ground water sampling protocols. Remote access to the data record, via phone modem communications, indicated the arrival of each plume over a few days and the subsequent geochemical reactions over the following weeks. Real-time availability of the monitoring record provided the information needed to initiate manual sampling efforts in response to changes in measured ground water quality, which proved the method and characterized the screened portion of the plume in detail through time. The methods and the case study described are presented to document the process for future use.

  5. Physiological response of wild dugongs (Dugong dugon) to out-of-water sampling for health assessment

    USGS Publications Warehouse

    Lanyon, Janet M.; Sneath, Helen L.; Long, Trevor; Bonde, Robert K.

    2010-01-01

    The dugong (Dugong dugon) is a vulnerable marine mammal with large populations living in urban Queensland waters. A mark-recapture program for wild dugongs has been ongoing in southern Queensland since 2001. This program has involved capture and in-water sampling of more than 700 dugongs where animals have been held at the water surface for 5 min to be gene-tagged, measured, and biopsied. In 2008, this program expanded to examine more comprehensively body condition, reproductive status, and the health of wild dugongs in Moreton Bay. Using Sea World's research vessel, captured dugongs were lifted onto a boat and sampled out-of-water to obtain accurate body weights and morphometrics, collect blood and urine samples for baseline health parameters and hormone profiles, and ultrasound females for pregnancy status. In all, 30 dugongs, including two pregnant females, were sampled over 10 d and restrained on deck for up to 55 min each while biological data were collected. Each of the dugongs had their basic temperature-heart rate-respiration (THR) monitored throughout their period of handling, following protocols developed for the West Indian manatee (Trichechus manatus). This paper reports on the physiological response of captured dugongs during this out-of-water operation as indicated by their vital signs and the suitability of the manatee monitoring protocols to this related sirenian species. A recommendation is made that the range of vital signs of these wild dugongs be used as benchmark criteria of normal parameters for other studies that intend to sample dugongs out-of-water.

  6. Water-quality sampling by the U.S. Geological Survey-Standard protocols and procedures

    USGS Publications Warehouse

    Wilde, Franceska D.

    2010-01-01

    Thumbnail of and link to report PDF (1.0 MB) The U.S. Geological Survey (USGS) develops the sampling procedures and collects the data necessary for the accurate assessment and wise management of our Nation's surface-water and groundwater resources. Federal and State agencies, water-resource regulators and managers, and many organizations and interested parties in the public and private sectors depend on the reliability, timeliness, and integrity of the data we collect and the scientific soundness and impartiality of our data assessments and analysis. The standard data-collection methods uniformly used by USGS water-quality personnel are peer reviewed, kept up-to-date, and published in the National Field Manual for the Collection of Water-Quality Data (http://pubs.water.usgs.gov/twri9A/).

  7. [CCA of water beetles' distribution and environmental factors in lentic samples of north Changbai Mountain].

    PubMed

    We, Yulian; Ji, Lanzhu; Wang, Miao; Zhao, Min

    2002-01-01

    The relationship between 28 species water beetles in 12 lentic samples and environmental factors of North Chang-bai Mountain was studied by Cononical Correspondence Analysis (CCA). The results showed that degree of underwater humus and altitude are the major factors correlated with beetles distribution, and the correlation coefficients of environmental factors and axes of CCA were 0.8371 and 0.7206 respectively, while water temperature and plant density also had certain effects. Under the influence of environmental factors, the water beetles' populations were different in different habitat. Coelambus impressopunctatus, Colymbetes magnus, Helophorus browni, Haliplus spp. distributed in deep water pool. Water temperature was not important for those beetles. Ilybius sp. and Limnebius glabriventris correlated with altitude and humus. PMID:11962329

  8. Assessment of total PPCP Pollution in Water Samples Using a New Contamination Index

    NASA Astrophysics Data System (ADS)

    Conkle, J. L.; Huang, W.; Sickman, J. O.; Gan, J.

    2012-12-01

    Numerous studies document the presence of pharmaceutical and personal care products (PPCPs) in the environment, specifically near treated wastewater effluent, septic discharge and large-scale agricultural operations. Additionally, managed aquifer recharge may be a source of these contaminants. Groundwater quality is a major concern in California, as ~40% of residents consume it domestically and some communities such as Beaumont, depend on it entirely. Groundwater in Beaumont is influenced by all of the PPCP sources mentioned above. In the Beaumont Groundwater Management Zone we observed four distinct regions of groundwater that could be described according to their levels of anthropogenic impacts. The groundwater regions heavily influenced by wastewater effluent, high densities of septic systems and managed aquifer recharge had the highest concentrations and detections of PPCPs. To better describe the total levels of pollution and place our findings in the context of the greater body of data on PPCPs in the aquatic environment, a PPCP contamination index was developed from the peer-reviewed literature. The index equation was developed and validated using 21 previously published studies (285 total samples) on PPCPs in the aquatic environment as well as through sensitivity analysis. From the published literature we determined index values that fall into three classes: light (<1.8), moderate (1.8 - 4.1) and heavy (>4.1). PPCP contamination in Coopers Creek near the Beaumont WWTP discharge was at the upper end of the moderate range (3.6 to 3.8). The groundwater wells along the flow path of Coopers Creek were lightly contaminated (1.3 to 1.8) and groundwater wells influenced by septic waste and managed aquifer recharge were all <1. These values are typical for groundwater and wastewater effluent mixed with surface water found in the literature at PPCP contaminated sites. In addition to describing total PPCP contamination within a study, this index will also allow for

  9. Water Quality Sampling Locations Along the Shoreline of the Columbia River, Hanford Site, Washington

    SciTech Connect

    Peterson, Robert E.; Patton, Gregory W.

    2009-12-14

    As environmental monitoring evolved on the Hanford Site, several different conventions were used to name or describe location information for various sampling sites along the Hanford Reach of the Columbia River. These methods range from handwritten descriptions in field notebooks to the use of modern electronic surveying equipment, such as Global Positioning System receivers. These diverse methods resulted in inconsistent archiving of analytical results in various electronic databases and published reports because of multiple names being used for the same site and inaccurate position data. This document provides listings of sampling sites that are associated with groundwater and river water sampling. The report identifies names and locations for sites associated with sampling: (a) near-river groundwater using aquifer sampling tubes; (b) riverbank springs and springs areas; (c) pore water collected from riverbed sediment; and (d) Columbia River water. Included in the listings are historical names used for a particular site and the best available geographic coordinates for the site, as of 2009. In an effort to create more consistency in the descriptive names used for water quality sampling sites, a naming convention is proposed in this document. The convention assumes that a unique identifier is assigned to each site that is monitored and that this identifier serves electronic database management requirements. The descriptive name is assigned for the convenience of the subsequent data user. As the historical database is used more intensively, this document may be revised as a consequence of discovering potential errors and also because of a need to gain consensus on the proposed naming convention for some water quality monitoring sites.

  10. Membrane solid-phase extraction: Field application for isolation of polycyclic aromatic hydrocarbons from water samples

    SciTech Connect

    Furlong, E.T.; Koleis, J.C.; Gates, P.M.

    1995-12-31

    Solid-phase extraction (SPE) membranes (M-SPE) were used to isolate microgram-per-liter to nanogram-per-liter quantities of polycyclic aromatic hydrocarbons (PAH) in 4- to 8-liter ground-water samples from a crude-oil-contaminated ground-water site near Bemidji, Minnesota. The M-SPE method was evaluated (1) under laboratory conditions using reagent water fortified with individual PAH at 1.23 micrograms per liter, and (2) at the Bemidji site. At the site, ground-water samples were processed and PAH isolated using a M-SPE system connected directly to the well pump. Following sample isolation, all M-SPE samples were extracted using dichloromethane and analyzed by gas chromatography-mass spectrometry with selected-ion monitoring. Operationally, the M-SPE method provided a simple means to isolate PAH on site at the wellhead, particularly for anoxic water samples. Acceptable recoveries, ranging from 56 to over 100 percent, were observed for lower molecular weight PAH (naphthalene to pyrene) using the M-SPE method. Recoveries using M-SPE were somewhat lower, but reproducible, for higher molecular weight PAH (chrysene to benzo[ghi]perylene), ranging from 18 to 56 percent. M-SPE provides the capability to collect and field isolate PAH from a sufficiently large number of samples to identify environmental chemical processes occurring at individual compound concentrations of 50 to 1,200 nanograms per liter. Using M-SPE, the potential for facilitated transport of PAH by in situ-derived dissolved organic carbon (DOC) was evaluated at the site. Plots comparing DOC and PAH concentrations indicate that PAH concentrations increase exponentially with linear increases in DOC concentrations.

  11. Availability of Additional Water for Chiricahua National Monument, Cochise County, Arizona

    USGS Publications Warehouse

    Johnson, Phillip W.

    1962-01-01

    The Chiricahua National Monument is in the eastern part of Cochise County, Ariz. The monument is about 35 miles southeast of Wilicox in the north end of the Chiricahua Mountains which border Sulphur Springs Valley on the west. The area is drained by two intermittent washes, one in Bonita and the other in Rhyolite Canyons. Shake Spring is the present source of water for the monument. It ranges in rate of flow from 2 to 12 gpm (gallons per minute) and during dry periods It is not adequate to support the requirements of the monument. Ample water to meet the present and future needs of the Chiricahua National Monument is available from a combination of several sources - undeveloped springs or seeps, capture of runoff out of the canyons, and wells drilled in the alluvium.

  12. Corrosion and Heat Transfer Characteristics of Water Dispersed with Carboxylate Additives and Multi Walled Carbon Nano Tubes

    NASA Astrophysics Data System (ADS)

    Moorthy, Chellapilla V. K. N. S. N.; Srinivas, Vadapalli

    2016-02-01

    This paper summarizes a recent work on anti-corrosive properties and enhanced heat transfer properties of carboxylated water based nanofluids. Water mixed with sebacic acid as carboxylate additive found to be resistant to corrosion and suitable for automotive environment. The carboxylated water is dispersed with very low mass concentration of carbon nano tubes at 0.025, 0.05 and 0.1 %. The stability of nanofluids in terms of zeta potential is found to be good with carboxylated water compared to normal water. The heat transfer performance of nanofluids is carried out on an air cooled heat exchanger similar to an automotive radiator with incoming air velocities across radiator at 5, 10 and 15 m/s. The flow Reynolds number of water is in the range of 2500-6000 indicating developing flow regime. The corrosion resistance of nanofluids is found to be good indicating its suitability to automotive environment. There is a slight increase in viscosity and marginal decrease in the specific heat of nanofluids with addition of carboxylate as well as CNTs. Significant improvement is observed in the thermal conductivity of nanofluids dispersed with CNTs. During heat transfer experimentation, the inside heat transfer coefficient and overall heat transfer coefficient has also improved markedly. It is also found that the velocity of air and flow rate of coolant plays an important role in enhancement of the heat transfer coefficient and overall heat transfer coefficient.

  13. Performance of a novel high throughput method for the determination of VX in drinking water samples.

    PubMed

    Knaack, Jennifer S; Zhou, Yingtao; Magnuson, Matthew; Silvestri, Erin; Johnson, Rudolph C

    2013-03-01

    VX (O-ethyl-S-(2-diisopropylaminoethyl) methylphosphonothioate) is a highly toxic organophosphorus nerve agent, and even low levels of contamination in water can be harmful. Measurement of low concentrations of VX in aqueous matrixes is possible using an immunomagnetic scavenging technique and detection using liquid chromatography/tandem-mass spectrometry. Performance of the method was characterized in high-performance liquid chromatography (HPLC)-grade water preserved with sodium omadine, an antimicrobial agent, and sodium thiosulfate, a dechlorinating agent, over eight analytical batches with quality control samples analyzed over 10 days. The minimum reportable level was 25 ng/L with a linear dynamic range up to 4.0 μg/L. The mean accuracies for two quality control samples containing VX at concentrations of 0.250 and 2.00 μg/L were 102 ± 3% and 103 ± 6%, respectively. The stability of VX was determined in five tap water samples representing a range of water quality parameters and disinfection practices over a 91 day period. In preserved tap water samples, VX recovery was between 81 and 92% of the fortified amount, 2.0 μg/L, when analyzed immediately after preparation. Recovery of VX decreased to between 31 and 45% of the fortified amount after 91 days, indicating hydrolysis of VX. However, the preservatives minimized the hydrolysis rate to close to the theoretical limit. The ability to detect low concentrations of VX in preserved tap water 91 days after spiking suggests applicability of this method for determining water contamination with VX and utility during environmental remediation. PMID:23402290

  14. Addition of a Worm Leachate as Source of Humic Substances in the Drinking Water of Broiler Chickens

    PubMed Central

    Gomez-Rosales, S.; de L. Angeles, M.

    2015-01-01

    The objective of this research was to evaluate the growth performance, the apparent ileal digestibility of nitrogen and energy, the retention of nutrients and the apparent metabolizable energy corrected to zero nitrogen retention (AMEn) in broiler chickens supplemented with increasing doses of a worm leachate (WL) as a source of humic substances (HS) in the drinking water. In Exp. 1, 140 male broilers were penned individually and assigned to four WL levels (0%, 10%, 20%, and 30%) mixed in the drinking water from 21 to 49 days of age. Water was offered in plastic bottles tied to the cage. In Exp. 2, 600 male broilers from 21 to 49 days of age housed in floor pens were assigned to three levels of WL (0%, 10%, and 20%) mixed in the drinking water. The WL was mixed with tap water in plastic containers connected by plastic tubing to bell drinkers. The results of both experiments were subjected to analysis of variance and polynomial contrasts. In Exp. 1, the daily water consumption was similar among treatments but the consumption of humic, fulvic, and total humic acids increased linearly (p<0.01) as the WL increased in the drinking water. The feed conversion (p<0.01) and the ileal digestibility of energy, the excretion of dry matter and energy, the retention of dry matter, ash and nitrogen and the AMEn showed quadratic responses (p<0.05) relative to the WL levels in drinking water. In Exp. 2, the increasing level of WL in the drinking water had quadratic effects on the final body weight, daily weight gain and feed conversion ratio (p<0.05). The addition of WL as a source of HS in the drinking water had beneficial effects on the growth performance, ileal digestibility of energy, the retention of nutrients as well on the AMEn in broiler chickens; the best results were observed when the WL was mixed at levels of 20% to 30% in the drinking water. PMID:25557817

  15. Hydrogeology and Physical Characteristics of Water Samples at the Red River Aluminum Site, Stamps, Arkansas

    NASA Astrophysics Data System (ADS)

    Czarnecki, J. B.; Stanton, G. P.; Freiwald, D. A.

    2001-12-01

    The Red River Aluminum site near Stamps, Arkansas, contains waste piles of salt cake and metal byproducts from the smelting of aluminum. The waste piles are subjected to about 50 inches of rainfall a year, resulting in the dissolution of the salts and metal. To assess the potential threat to underlying ground-water resources at the site, its hydrogeology was characterized by measuring water levels and field parameters of water quality in 23 wells and at 2 surface-water sites. Seventeen of these monitor wells were constructed at various depths for this study to allow for the separate characterization of the shallow and deep ground-water systems, the calculation of vertical gradients, and the collection of water samples at different depths within the flow system. Lithologic descriptions from drill-hole cuttings and geophysical logs indicate the presence of interbedded sands, gravels, silts, and clays to depths of 65 feet. The regionally important Sparta aquifer underlies the site. Water levels in shallow wells indicate radial flow away from the salt-cake pile located near the center of the site. Flow in the deep system is to the west and southwest toward Bodcau Creek. Water-level data from eight piezometer nests indicate a downward hydraulic gradient from the shallow to deep systems across the site. Values of specific conductance (an indicator of dissolved salts) ranged from 215 to 196,200 microsiemens per centimeter and indicate that saline waters are being transported horizontally and vertically downward away from the site.

  16. Free water 3H concentrations in serum samples collected during 1969-1992 in Akita, Japan.

    PubMed

    Hisamatsu, Shun'ichi; Inoue, Yoshikazu; Hachiya, Noriyuki; Katoh, Kiyoshi; Nakagomi, Toyoko; Nakagomi, Osamu; Motohashi, Yutaka; Takizawa, Yukio

    2003-08-01

    The measurements for human and environmental samples from the 1960's and 1970's are important to understand the long-term transfer of 3H from the environment to the human body. The authors have previously reported 3H concentrations in diet samples collected in Akita Prefecture during 1969-1988. Serum samples from persons living in Akita Prefecture during 1969-1992 were recently obtained. The samples were originally gathered for medical examinations and stored in freezers at -20 degrees C. Composite samples from 100 persons on average were made for analysis. The free water 3H (FWT) concentrations in those samples were determined and compared with 3H concentrations in diet samples and precipitation. The long-term variation pattern of the FWT concentrations in the serum samples was similar to patterns in the diet samples and precipitation, but the FWT concentrations in the serum samples were slightly higher than those in the latter two. A single compartment model calculation showed that the apparent mean residence time of serum FWT was 1.4 y using precipitation as an input to the compartment. PMID:12938967

  17. Measuring pesticides in surface waters - continuous versus event-based sampling design

    NASA Astrophysics Data System (ADS)

    Eyring, J.; Bach, M.; Frede, H.-G.

    2009-04-01

    Monitoring pesticides in surface waters is still a work- and cost-intensive procedure. Therefore, studies are normally carried out with a low monitoring frequency or with only a small selection of substances to be analyzed. In this case, it is not possible to picture the high temporal variability of pesticide concentrations, depending on application dates, weather conditions, cropping seasons and other factors. In 2007 the Institute of Landscape Ecology and Resource Management at Giessen University implemented a monitoring program during two pesticide application periods aiming to produce a detailed dataset of pesticide concentration for a wide range of substances, and which would also be suitable for the evaluation of catchment-scale pesticide exposure models. The Weida catchment in Thuringia (Eastern Germany) was selected as study area due to the availability of detailed pesticide application data for this region. The samples were taken from the river Weida at the gauge Zeulenroda, where it flows into a drinking water reservoir. The catchment area is 102 km². 67% of the area are in agricultural use, the main crops being winter wheat, maize, winter barley and winter rape. Dominant soil texture classes are loamy sand and loamy silt. About one third of the agricultural area is drained. The sampling was carried out in cooperation with the water supply agency of Thuringia (Fernwasserversorgung Thueringen). The sample analysis was done by the Institute of Environmental Research at Dortmund University. Two sampling schemes were carried out using two automatic samplers: continuous sampling with composite samples bottled two times per week and event-based sampling triggered by a discharge threshold. 53 samples from continuous sampling were collected. 19 discharge events were sampled with 45 individual samples (one to six per event). 34 pesticides and two metabolites were analyzed. 21 compounds were detected, nine of which having concentrations above the drinking water

  18. Interactions between organic additives and active powders in water-based lithium iron phosphate electrode slurries

    NASA Astrophysics Data System (ADS)

    Li, Chia-Chen; Lin, Yu-Sheng

    2012-12-01

    The interactions of organic additives with active powders are investigated and are found to have great influence on the determination of the mixing process for preparing electrode slurries with good dispersion and electrochemical properties of lithium iron phosphate (LiFePO4) electrodes. Based on the analyses of zeta potential, sedimentation, and rheology, it is shown that LiFePO4 prefers to interact with styrene-butadiene rubber (SBR) relative to other organic additives such as sodium carboxymethyl cellulose (SCMC), and thus shows preferential adsorption by SBR, whereas SBR has much lower efficiency than SCMC in dispersing LiFePO4. Therefore, for SCMC to interact with and disperse LiFePO4 before the interaction of LiFePO4 with SBR, it is suggested to mix SCMC with LiFePO4 prior to the addition of SBR during the slurry preparation process. For the electrode prepared via the suggested process, i.e., the sequenced adding process in which SCMC is mixed with active powders prior to the addition of SBR, a much better electrochemical performance is obtained than that of the one prepared via the process referred as the simultaneous adding process, in which mixing of SCMC and SBR with active powders in simultaneous.

  19. Additive Effects on Si3n4 Oxidation/Volatilization in Water Vapor

    NASA Technical Reports Server (NTRS)

    Opila, Elizabeth J.; Robinson, R. Craig; Fox, Dennis S.; Wenglarz, Richard A.; Ferber, Mattison K.

    2002-01-01

    Two commercially available additive-containing silicon nitride materials were exposed in four environments which range in severity from dry oxygen at 1 atm pressure, and low gas velocity to an actual turbine engine. Oxidation and volatilization kinetics were monitored at temperatures ranging from 1066 to 1400 C. The main purpose of this paper is to examine the surface oxide morphology resulting from the exposures. It was found that the material surface was enriched in rare earth silicate phases in combustion environments when compared to the oxides formed on materials exposed in dry oxygen. However, the in situ formation of rare earth disilicate phases offered little additional protection from the volatilization of silica observed in combustion environments. It was concluded that externally applied environmental barrier coatings are needed to protect additive-containing silicon nitride materials from volatilization reactions in combustion environments. Introduction Si3N4 is proposed for use as components, such as vanes, in turbine applications. Tens of thousands of hours of life are needed for both land-based turbines and aeropropulsion applications. Additive-containing SisN4 materials are

  20. 76 FR 7106 - Food Additives Permitted in Feed and Drinking Water of Animals; Formic Acid

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-09

    ... notice published in the Federal Register of December 7, 2009 (74 FR 64091), FDA announced that a food... agent in swine feed. This action is in response to a food additive petition filed by Kemira Oyj of... safe use of formic acid as an acidifying agent at levels not to exceed 1.2 percent in swine feed....