27 CFR 24.243 - Filtering aids.

Code of Federal Regulations, 2014 CFR

2014-04-01

... fibers, pulps, earths, or similar materials, may be used as filtering aids in the cellar treatment and finishing of wine. Agar-agar, carrageenan, cellulose, and diatomaceous earth are commonly employed inert... records need be maintained concerning their use. However, if the inert material is dissolved in water...

Extended Kalman filter for attitude estimation of the earth radiation budget satellite

NASA Technical Reports Server (NTRS)

Deutschmann, Julie; Bar-Itzhack, Itzhack Y.

1989-01-01

The design and testing of an Extended Kalman Filter (EKF) for ground attitude determination, misalignment estimation and sensor calibration of the Earth Radiation Budget Satellite (ERBS) are described. Attitude is represented by the quaternion of rotation and the attitude estimation error is defined as an additive error. Quaternion normalization is used for increasing the convergence rate and for minimizing the need for filter tuning. The development of the filter dynamic model, the gyro error model and the measurement models of the Sun sensors, the IR horizon scanner and the magnetometers which are used to generate vector measurements are also presented. The filter is applied to real data transmitted by ERBS sensors. Results are presented and analyzed and the EKF advantages as well as sensitivities are discussed. On the whole the filter meets the expected synergism, accuracy and robustness.

Bacterial treatment effectiveness of point-of-use ceramic water filters.

PubMed

Bielefeldt, Angela R; Kowalski, Kate; Summers, R Scott

2009-08-01

Laboratory experiments were conducted on six point-of-use (POU) ceramic water filters that were manufactured in Nicaragua; two filters were used by families for ca. 4 years and the other filters had limited prior use in our lab. Water spiked with ca. 10(6)CFU/mL of Escherichia coli was dosed to the filters. Initial disinfection efficiencies ranged from 3 - 4.5 log, but the treatment efficiency decreased with subsequent batches of spiked water. Silver concentrations in the effluent water ranged from 0.04 - 1.75 ppb. Subsequent experiments that utilized feed water without a bacterial spike yielded 10(3)-10(5)CFU/mL bacteria in the effluent. Immediately after recoating four of the filters with a colloidal silver solution, the effluent silver concentrations increased to 36 - 45 ppb and bacterial disinfection efficiencies were 3.8-4.5 log. The treatment effectiveness decreased to 0.2 - 2.5 log after loading multiple batches of highly contaminated water. In subsequent loading of clean water, the effluent water contained <20-41 CFU/mL in two of the filters. This indicates that the silver had some benefit to reducing bacterial contamination by the filter. In general these POU filters were found to be effective, but showed loss of effectiveness with time and indicated a release of microbes into subsequent volumes of water passed through the system.

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

PubMed

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

2015-01-01

Household sand filters are applied to treat arsenic- and iron-containing anoxic groundwater that is used as drinking water in rural areas of North Vietnam. These filters immobilize poisonous arsenic (As) via co-oxidation with Fe(II) and sorption to or co-precipitation with the formed Fe(III) (oxyhydr)oxides. However, information is lacking regarding the effect of the frequency and duration of filter use as well as of filter sand replacement on the residual As concentrations in the filtered water and on the presence of potentially pathogenic bacteria in the filtered and stored water. We therefore scrutinized a household sand filter with respect to As removal efficiency and the presence of fecal indicator bacteria in treated water as a function of filter operation before and after sand replacement. Quantification of As in the filtered water showed that periods of intense daily use followed by periods of non-use and even sand replacement did not significantly (p<0.05) affect As removal efficiency. The As concentration was reduced during filtration from 115.1 ± 3.4 μg L(-1) in the groundwater to 5.3 ± 0.7 μg L(-1) in the filtered water (95% removal). The first flush of water from the filter contained As concentrations below the drinking water limit and suggests that this water can be used without risk for human health. Colony forming units (CFUs) of coliform bacteria increased during filtration and storage from 5 ± 4 per 100mL in the groundwater to 5.1 ± 1.5 × 10(3) and 15 ± 1.4 × 10(3) per 100mL in the filtered water and in the water from the storage tank, respectively. After filter sand replacement, CFUs of Escherichia coli of <100 per 100mL were quantified. None of the samples contained CFUs of Enterococcus spp. No critical enrichment of fecal indicator bacteria belonging to E. coli or Enterococcus spp. was observed in the treated drinking water by qPCR targeting the 23S rRNA gene. The results demonstrate the efficient and reliable performance of household

Predicting water filter and bottled water use in Appalachia: a community-scale case study.

PubMed

Levêque, Jonas G; Burns, Robert C

2017-06-01

A questionnaire survey was conducted in order to assess residents' perceptions of water quality for drinking and recreational purposes in a mid-sized city in northcentral West Virginia. Two logistic regression analyses were conducted in order to investigate the factors that influence bottle use and filter use. Results show that 37% of respondents primarily use bottled water and that 58% use a household filter when drinking from the tap. Respondents with lower levels of environmental concern, education levels, and lower organoleptic perceptions were most likely to perceive health risks from tap water consumption, and were most likely to use bottled water. Income, age, and organoleptic perceptions were predictors of water filter use among respondents. Clean water for recreational purposes was not found to be significant with either of these models. Our results demonstrate that bottle use and filter use are explained differently. We argue that more education and better communication about local tap water quality would decrease the use of bottled water. We demonstrate that household filters could be used as an alternative to bottled water.

Standard reference water samples for rare earth element determinations

USGS Publications Warehouse

Verplanck, P.L.; Antweiler, Ronald C.; Nordstrom, D. Kirk; Taylor, Howard 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.

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

PubMed

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

2017-10-01

Arsenic contamination of drinking water is a serious threat to the health of hundreds of millions of people worldwide. In the United States ~3 million individuals drink well water that contains arsenic levels above the Environmental Protection Agency (EPA) maximum contaminant level (MCL) of 10μg/L. Several technologies are available to remove arsenic from well water including anion exchange, adsorptive media and reverse osmosis. In addition, bottled water is an alternative to drinking well water contaminated with arsenic. However, there are several drawbacks associated with these approaches including relatively high cost and, in the case of bottled water, the generation of plastic waste. In this study, we tested the ability of five tabletop water pitcher filters to remove arsenic from drinking water. We report that only one tabletop water pitcher filter tested, ZeroWater®, reduced the arsenic concentration, both As 3+ and As 5+ , from 1000μg/L to < 3μg/L, well below the MCL. Moreover, the amount of total dissolved solids or competing ions did not affect the ability of the ZeroWater® filter to remove arsenic below the MCL. Thus, the ZeroWater® pitcher filter is a cost effective and short-term solution to remove arsenic from drinking water and its use reduces plastic waste associated with bottled water. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Effectiveness of Table Top Water Pitcher Filters to Remove Arsenic from Drinking Water

PubMed Central

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

2017-01-01

Arsenic contamination of drinking water is a serious threat to the health of hundreds of millions of people worldwide. In the United States ~3 million individuals drink well water that contains arsenic levels above the Environmental Protection Agency (EPA) maximum contaminant level (MCL) of 10 μg/L. Several technologies are available to remove arsenic from well water including anion exchange, adsorptive media and reverse osmosis. In addition, bottled water is an alternative to drinking well water contaminated with arsenic. However, there are several drawbacks associated with these approaches including relatively high cost and, in the case of bottled water, the generation of plastic waste. In this study, we tested the ability of five tabletop water pitcher filters to remove arsenic from drinking water. We report that only one tabletop water pitcher filter tested, ZeroWater®, reduced the arsenic concentration, both As3+ and As5+, from 1,000 μg/L to < 3 μg/L, well below the MCL. Moreover, the amount of total dissolved solids or competing ions did not affect the ability of the ZeroWater® filter to remove arsenic below the MCL. Thus, the ZeroWater® pitcher filter is a cost effective and short-term solution to remove arsenic from drinking water and its use reduces plastic waste associated with bottled water. PMID:28719869

Replicating the microbial community and water quality performance of full-scale slow sand filters in laboratory-scale filters.

PubMed

Haig, Sarah-Jane; Quince, Christopher; Davies, Robert L; Dorea, Caetano C; Collins, Gavin

2014-09-15

Previous laboratory-scale studies to characterise the functional microbial ecology of slow sand filters have suffered from methodological limitations that could compromise their relevance to full-scale systems. Therefore, to ascertain if laboratory-scale slow sand filters (L-SSFs) can replicate the microbial community and water quality production of industrially operated full-scale slow sand filters (I-SSFs), eight cylindrical L-SSFs were constructed and were used to treat water from the same source as the I-SSFs. Half of the L-SSFs sand beds were composed of sterilized sand (sterile) from the industrial filters and the other half with sand taken directly from the same industrial filter (non-sterile). All filters were operated for 10 weeks, with the microbial community and water quality parameters sampled and analysed weekly. To characterize the microbial community phyla-specific qPCR assays and 454 pyrosequencing of the 16S rRNA gene were used in conjunction with an array of statistical techniques. The results demonstrate that it is possible to mimic both the water quality production and the structure of the microbial community of full-scale filters in the laboratory - at all levels of taxonomic classification except OTU - thus allowing comparison of LSSF experiments with full-scale units. Further, it was found that the sand type composing the filter bed (non-sterile or sterile), the water quality produced, the age of the filters and the depth of sand samples were all significant factors in explaining observed differences in the structure of the microbial consortia. This study is the first to the authors' knowledge that demonstrates that scaled-down slow sand filters can accurately reproduce the water quality and microbial consortia of full-scale slow sand filters. Copyright © 2014 Elsevier Ltd. All rights reserved.

Global-scale water circulation in the Earth's mantle: Implications for the mantle water budget in the early Earth

NASA Astrophysics Data System (ADS)

Nakagawa, Takashi; Spiegelman, Marc W.

2017-04-01

We investigate the influence of the mantle water content in the early Earth on that in the present mantle using numerical convection simulations that include three processes for redistribution of water: dehydration, partitioning of water into partially molten mantle, and regassing assuming an infinite water reservoir at the surface. These models suggest that the water content of the present mantle is insensitive to that of the early Earth. The initial water stored during planetary formation is regulated up to 1.2 OMs (OM = Ocean Mass; 1.4 ×1021 kg), which is reasonable for early Earth. However, the mantle water content is sensitive to the rheological dependence on the water content and can range from 1.2 to 3 OMs at the present day. To explain the evolution of mantle water content, we computed water fluxes due to subducting plates (regassing), degassing and dehydration. For weakly water dependent viscosity, the net water flux is almost balanced with those three fluxes but, for strongly water dependent viscosity, the regassing dominates the water cycle system because the surface plate activity is more vigorous. The increased convection is due to enhanced lubrication of the plates caused by a weak hydrous crust for strongly water dependent viscosity. The degassing history is insensitive to the initial water content of the early Earth as well as rheological strength. The degassing flux from Earth's surface is calculated to be approximately O (1013) kg /yr, consistent with a coupled model of climate evolution and mantle thermal evolution.

Silver Dissolution and Release from Ceramic Water Filters.

PubMed

Mittelman, Anjuliee M; Lantagne, Daniele S; Rayner, Justine; Pennell, Kurt D

2015-07-21

Application of silver nanoparticles (nAg) or silver nitrate (AgNO3) has been shown to improve the microbiological efficacy of ceramic water filters used for household water treatment. Silver release, however, can lead to undesirable health effects and reduced filter effectiveness over time. The objectives of this study were to evaluate the contribution of nanoparticle detachment, dissolution, and cation exchange to silver elution, and to estimate silver retention under different influent water chemistries. Dissolved silver (Ag(+)) and nAg release from filter disks painted with 0.03 mg/g casein-coated nAg or AgNO3 were measured as a function of pH (5-9), ionic strength (1-50 mM), and cation species (Na(+), Ca(2+), Mg(2+)). Silver elution was controlled by dissolution as Ag(+) and subsequent cation exchange reactions regardless of the applied silver form. Effluent silver levels fell below the drinking water standard (0.1 mg/L) after flushing with 30-42 pore volumes of pH 7, 10 mM NaNO3 at pH 7. When the influent water was at pH 5, contained divalent cations or 50 mM NaNO3, silver concentrations were 5-10 times above the standard. Our findings support regular filter replacement and indicate that saline, hard, or acidic waters should be avoided to minimize effluent silver concentrations and preserve silver treatment integrity.

NASA-Enhanced Water Bottles Filter Water on the Go

NASA Technical Reports Server (NTRS)

2014-01-01

Complex systems on the ISS collect and recycle moisture from every possible source-including sweat and urine-to be filtered for recycled use. Greenbrae, California-based ÖKO now sells a water bottle that employs NASA filtration media to purify water as the user squeezes it through the device.

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

PubMed

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

2017-06-01

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

Desorption of micropollutant from spent carbon filters used for water purifier.

PubMed

Kwon, Da-Sol; Tak, So-Yeon; Lee, Jung-Eun; Kim, Moon-Kyung; Lee, Young Hwa; Han, Doo Won; Kang, Sanghyeon; Zoh, Kyung-Duk

2017-07-01

In this study, to examine the accumulated micropollutants in the spent carbon filter used in the water purifier, first, the method to desorb micropollutant from the activated carbon was developed and optimized. Then, using this optimized desorption conditions, we examined which micropollutants exist in spent carbon filters collected from houses in different regions in Korea where water purifiers were used. A total of 11 micropollutants (caffeine (CFF), acetaminophen (ACT), sulfamethazine (SMA), sulfamethoxazole (SMZ), metoprolol (MTP), carbamazepine (CBM), naproxen (NPX), bisphenol-A (BPA), ibuprofen (IBU), diclofenac (DCF), and triclocarban (TCB)) were analyzed using LC/MS-MS from the spent carbon filters. CFF, NPX, and DCF had the highest detection frequencies (>60%) in the carbon filters (n = 100), whereas SMA, SMZ, and MTP were only detected in the carbon filters, but not in the tap waters (n = 25), indicating that these micropollutants, which exist less than the detection limit in tap water, were accumulated in the carbon filters. The regional micropollutant detection patterns in the carbon filters showed higher levels of micropollutants, especially NPX, BPA, IBU, and DCF, in carbon filters collected in the Han River and Nakdong River basins where large cities exist. The levels of micropollutants in the carbon filter were generally lower in the regions where advanced oxidation processes (AOPs) were employed at nearby water treatment plants (WTPs), indicating that AOP process in WTP is quite effective in removing micropollutant. Our results suggest that desorption of micropollutant from the carbon filter used can be a tool to identify micropollutants present in tap water with trace amounts or below the detection limit.

Accretion disc origin of the Earth's water.

PubMed

Vattuone, Luca; Smerieri, Marco; Savio, Letizia; Asaduzzaman, Abu Md; Muralidharan, Krishna; Drake, Michael J; Rocca, Mario

2013-07-13

Earth's water is conventionally believed to be delivered by comets or wet asteroids after the Earth formed. However, their elemental and isotopic properties are inconsistent with those of the Earth. It was thus proposed that water was introduced by adsorption onto grains in the accretion disc prior to planetary growth, with bonding energies so high as to be stable under high-temperature conditions. Here, we show both by laboratory experiments and numerical simulations that water adsorbs dissociatively on the olivine {100} surface at the temperature (approx. 500-1500 K) and water pressure (approx. 10⁻⁸ bar) expected for the accretion disc, leaving an OH adlayer that is stable at least up to 900 K. This may result in the formation of many Earth oceans, provided that a viable mechanism to produce water from hydroxyl exists. This adsorption process must occur in all disc environments around young stars. The inevitable conclusion is that water should be prevalent on terrestrial planets in the habitable zone around other stars.

Field investigation of arsenic in ceramic pot filter-treated drinking water.

PubMed

Archer, A R; Elmore, A C; Bell, E; Rozycki, C

2011-01-01

Ceramic pot filters (CPFs) is one of several household water treatment technologies that is used to treat drinking water in developing areas. The filters have the advantage of being able to be manufactured using primarily locally available materials and local labor. However, naturally-occurring arsenic present in the clay used to make the filters has the potential to contaminate the water in excess of the World Health Organization drinking water standard of 0.01 mg/L. A manufacturing facility in Guatemala routinely rinses filters to reduce arsenic concentrations prior to distribution to consumers. A systemic study was performed to evaluate the change in arsenic concentrations with increasing volumes of rinse water. Arsenic field kit results were compared to standard method laboratory results, and dissolved versus suspended arsenic concentrations in CPF-treated water were evaluated. The results of the study suggest that rinsing is an effective means of mitigating arsenic leached from the filters, and that even in the absence of a formal rinsing program, routine consumer use may result in the rapid decline of arsenic concentrations. More importantly, the results indicate that filter manufacturers should give strong consideration to implementing an arsenic testing program.

Impact of chlorination on silver elution from ceramic water filters.

PubMed

Lyon-Marion, Bonnie A; Mittelman, Anjuliee M; Rayner, Justine; Lantagne, Daniele S; Pennell, Kurt D

2018-06-05

Applying silver nanoparticles (nAg) or silver nitrate (AgNO 3 ) to ceramic water filters improves microbiological efficacy, reduces biofilm formation, and protects stored water from recontamination. A challenge in ceramic filter production is adding sufficient silver to achieve these goals without exceeding the maximum recommended silver concentration in drinking water. Silver release is affected by silver type, application method, and influent water chemistry. Despite a lack of data, there is an assumption that chlorinated water should not be used as influent water because it may increase silver elution. Thus, the objective of this work was to systematically evaluate the impact of chlorinated water (0-4 mg/L free chlorine residual, FCR) on silver release from ceramic filter disks painted with casein-coated nAg, painted with AgNO 3 , or containing fired-in nAg over a range of ionic strength (IS = 0-10 mM as NaNO 3 ) in the presence or absence of natural organic matter (NOM). Influent deionized water containing chlorine increased silver release 2-5-fold compared to controls. However, this effect of chlorine was mitigated at higher IS (≥1 mM) or in the presence of NOM (3 mg C/L). For filter disks painted with nAg or AgNO 3 , silver release increased with increasing IS (with or without chlorine), and effluent concentrations remained above the World Health Organization (WHO) guideline of 0.1 mg/L even after 30 h (80 pore volumes, PVs) of flow with a background solution of 10 mM NaNO 3 . Silver speciation (nAg vs. Ag + ) was monitored in effluent samples from painted or fired-in nAg filter disks. Results indicated that in general, greater than 90% of the eluted silver was due to Ag + dissolution rather than nAg release. Additionally, a filter disk prepared with fired-in nAg exhibited a lower % released in the nanoparticle form (nAg = 5% of total Ag in effluent) compared to painted on nAg (nAg = 14% of total Ag in effluent). The findings of

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

NASA Astrophysics Data System (ADS)

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

2018-01-01

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

Assessment of a membrane drinking water filter in an emergency setting.

PubMed

Ensink, Jeroen H J; Bastable, Andy; Cairncross, Sandy

2015-06-01

The performance and acceptability of the Nerox(TM) membrane drinking water filter were evaluated among an internally displaced population in Pakistan. The membrane filter and a control ceramic candle filter were distributed to over 3,000 households. Following a 6-month period, 230 households were visited and filter performance and use were assessed. Only 6% of the visited households still had a functioning filter, and the removal performance ranged from 80 to 93%. High turbidity in source water (irrigation canals), together with high temperatures and large family size were likely to have contributed to poor performance and uptake of the filters.

Attitude estimation of earth orbiting satellites by decomposed linear recursive filters

NASA Technical Reports Server (NTRS)

Kou, S. R.

1975-01-01

Attitude estimation of earth orbiting satellites (including Large Space Telescope) subjected to environmental disturbances and noises was investigated. Modern control and estimation theory is used as a tool to design an efficient estimator for attitude estimation. Decomposed linear recursive filters for both continuous-time systems and discrete-time systems are derived. By using this accurate estimation of the attitude of spacecrafts, state variable feedback controller may be designed to achieve (or satisfy) high requirements of system performance.

Water in the Earth's Interior: Distribution and Origin

NASA Astrophysics Data System (ADS)

Peslier, Anne H.; Schönbächler, Maria; Busemann, Henner; Karato, Shun-Ichiro

2017-10-01

The concentration and distribution of water in the Earth has influenced its evolution throughout its history. Even at the trace levels contained in the planet's deep interior (mantle and core), water affects Earth's thermal, deformational, melting, electrical and seismic properties, that control differentiation, plate tectonics and volcanism. These in turn influenced the development of Earth's atmosphere, oceans, and life. In addition to the ubiquitous presence of water in the hydrosphere, most of Earth's "water" actually occurs as trace amounts of hydrogen incorporated in the rock-forming silicate minerals that constitute the planet's crust and mantle, and may also be stored in the metallic core. The heterogeneous distribution of water in the Earth is the result of early planetary differentiation into crust, mantle and core, followed by remixing of lithosphere into the mantle after plate-tectonics started. The Earth's total water content is estimated at 18_{-15}^{+81} times the equivalent mass of the oceans (or a concentration of 3900_{-3300}^{+32700} ppm weight H2O). Uncertainties in this estimate arise primarily from the less-well-known concentrations for the lower mantle and core, since samples for water analyses are only available from the crust, the upper mantle and very rarely from the mantle transition zone (410-670 km depth). For the lower mantle (670-2900 km) and core (2900-4500 km), the estimates rely on laboratory experiments and indirect geophysical techniques (electrical conductivity and seismology). The Earth's accretion likely started relatively dry because it mainly acquired material from the inner part of the proto-planetary disk, where temperatures were too high for the formation and accretion of water ice. Combined evidence from several radionuclide systems (Pd-Ag, Mn-Cr, Rb-Sr, U-Pb) suggests that water was not incorporated in the Earth in significant quantities until the planet had grown to ˜60-90% of its current size, while core formation

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

NASA Astrophysics Data System (ADS)

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

2014-09-01

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

Sustainable colloidal-silver-impregnated ceramic filter for point-of-use water treatment.

PubMed

Oyanedel-Craver, Vinka A; Smith, James A

2008-02-01

Cylindrical colloidal-silver-impregnated ceramic filters for household (point-of-use) water treatment were manufactured and tested for performance in the laboratory with respect to flow rate and bacteria transport. Filters were manufactured by combining clay-rich soil with water, grog (previously fired clay), and flour, pressing them into cylinders, and firing them at 900 degrees C for 8 h. The pore-size distribution of the resulting ceramic filters was quantified by mercury porosimetry. Colloidal silver was applied to filters in different quantities and ways (dipping and painting). Filters were also tested without any colloidal-silver application. Hydraulic conductivity of the filters was quantified using changing-head permeability tests. [3H]H2O water was used as a conservative tracer to quantify advection velocities and the coefficient of hydrodynamic dispersion. Escherichia coli (E. coli) was used to quantify bacterial transport through the filters. Hydraulic conductivity and pore-size distribution varied with filter composition; hydraulic conductivities were on the order of 10(-5) cm/s and more than 50% of the pores for each filter had diameters ranging from 0.02 to 15 microm. The filters removed between 97.8% and 100% of the applied bacteria; colloidal-silver treatments improved filter performance, presumably by deactivation of bacteria. The quantity of colloidal silver applied per filter was more important to bacteria removal than the method of application. Silver concentrations in effluent filter water were initially greater than 0.1 mg/L, but dropped below this value after 200 min of continuous operation. These results indicate that colloidal-silver-impregnated ceramic filters, which can be made using primarily local materials and labor, show promise as an effective and sustainable point-of-use water treatment technology for the world's poorest communities.

Purification of arsenic-contaminated water with K-jarosite filters.

PubMed

Hott, Rodrigo C; Maia, Luiz F O; Santos, Mayra S; Faria, Márcia C; Oliveira, Luiz C A; Pereira, Márcio C; Bomfeti, Cleide A; Rodrigues, Jairo L

2018-05-01

The high toxicity and potential arsenic accumulation in several environments have encouraged the development of technologies for its removal from contaminated waters. However, the arsenic released into aquatic environment comes mainly from extremely acidic mining effluents, making harder to find stable adsorbents to be used in these conditions. In this work, K-jarosite particles were synthesized as a stable adsorbent in acidic medium for eliminating arsenic from contaminated water. The adsorption capacities of K-jarosite for As 3+ , As 5+ , and monomethylarsonic acid were 9.45, 12.36, and 8.21 mg g -1 , respectively. Most arsenic in water was adsorbed within the first 10 min, suggesting the fast arsenic adsorption kinetics of K-jarosite particles. Because of that, a K-jarosite filter was constructed for purifying water at a constant flow. The K-jarosite filter was highly efficient to treat arsenic-contaminated water from a Brazilian river, reducing the concentration of arsenic in water to near zero. These data suggest the K-jarosite filter can be used as a low-cost technology for purifying arsenic-contaminated water in acidic medium.

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

PubMed

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

2012-03-01

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

Assessment of polycarbonate filter in a molecular analytical system for the microbiological quality monitoring of recycled waters onboard ISS.

PubMed

Bechy-Loizeau, Anne-Laure; Flandrois, Jean-Pierre; Abaibou, Hafid

2015-07-01

On the ISS, as on Earth, water is an essential element for life and its quality control on a regular basis allows to ensure the health of the crew and the integrity of equipment. Currently, microbial water analysis onboard ISS still relies on the traditional culture-based microbiology methods. Molecular methods based on the amplification of nucleic acids for microbiological analysis of water quality show enormous potential and are considered as the best alternative to culture-based methods. For this reason, the Midass, a fully integrated and automated prototype was designed conjointly by ESA and bioMérieux for a rapid monitoring of the microbiological quality of air. The prototype allows air sampling, sample processing and the amplification/detection of nucleic acids. We describe herein the proof of principle of an analytical approach based on molecular biology that could fulfill the ESA's need for a rapid monitoring of the microbiological quality of recycled water onboard ISS. Both concentration and recovery of microorganisms are the main critical steps when the microfiltration technology is used for water analysis. Among filters recommended standards for monitoring the microbiological quality of the water, the polycarbonate filter was fully in line with the requirements of the ISO 7704-1985 standard in terms of efficacy of capture and recovery of bacteria. Moreover, this filter does not retain nucleic acids on the surface and has no inhibitory effect on their downstream processing steps such as purification and amplification/detection. Although the Midass system was designed for the treatment of air samples, the first results on the integration of PC filters were encouraging. Nevertheless, system modifications are needed to better adapt the Midass system for the monitoring of the microbiological water quality. Copyright © 2015 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

Modeling the Sustainability of a Ceramic Water Filter Intervention

PubMed Central

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

2014-01-01

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

Modeling the sustainability of a ceramic water filter intervention.

PubMed

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

2014-02-01

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

Microbiological effectiveness of locally produced ceramic filters for drinking water treatment in Cambodia.

PubMed

Brown, Joe; Sobsey, Mark D

2010-03-01

Low-cost options for the treatment of drinking water at the household level are being explored by the Cambodian government and non-governmental organizations (NGOs) working in Cambodia, where many lack access to improved drinking water sources and diarrhoeal diseases are the most prevalent cause of death in children under 5 years of age. The ceramic water purifier (CWP), a locally produced, low-cost ceramic filter, is now being implemented by several NGOs, and an estimated 100,000+households in the country now use them for drinking water treatment. Two candidate filters were tested for the reduction of bacterial and viral surrogates for waterborne pathogens using representative Cambodian drinking water sources (rainwater and surface water) spiked with Escherichia coli and bacteriophage MS2. Results indicate that filters were capable of reducing key microbes in the laboratory with mean reductions of E. coli of approximately 99% and mean reduction of bacteriophages of 90-99% over >600 litres throughput. Increased effectiveness was not observed in filters with an AgNO3 amendment. At under US$10 per filter, locally produced ceramic filters may be a promising option for drinking water treatment and safe storage at the household level.

Water and hydrogen are immiscible in Earth's mantle.

PubMed

Bali, Enikő; Audétat, Andreas; Keppler, Hans

2013-03-14

In the deep, chemically reducing parts of Earth's mantle, hydrous fluids contain significant amounts of molecular hydrogen (H2). Thermodynamic models of fluids in Earth's mantle so far have always assumed that molecular hydrogen and water are completely miscible. Here we show experimental evidence that water and hydrogen can coexist as two separate, immiscible phases. Immiscibility between water and hydrogen may be the cause of the formation of enigmatic, ultra-reducing domains in the mantle that contain moissanite (SiC) and other phases indicative of extremely reducing conditions. Moreover, the immiscibility between water and hydrogen may provide a mechanism for the rapid oxidation of Earth's upper mantle immediately following core formation.

A Compound Model for the Origin of Earth's Water

NASA Astrophysics Data System (ADS)

Izidoro, A.; de Souza Torres, K.; Winter, O. C.; Haghighipour, N.

2013-04-01

One of the most important subjects of debate in the formation of the solar system is the origin of Earth's water. Comets have long been considered as the most likely source of the delivery of water to Earth. However, elemental and isotopic arguments suggest a very small contribution from these objects. Other sources have also been proposed, among which local adsorption of water vapor onto dust grains in the primordial nebula and delivery through planetesimals and planetary embryos have become more prominent. However, no sole source of water provides a satisfactory explanation for Earth's water as a whole. In view of that, using numerical simulations, we have developed a compound model incorporating both the principal endogenous and exogenous theories, and investigating their implications for terrestrial planet formation and water delivery. Comets are also considered in the final analysis, as it is likely that at least some of Earth's water has cometary origin. We analyze our results comparing two different water distribution models, and complement our study using the D/H ratio, finding possible relative contributions from each source and focusing on planets formed in the habitable zone. We find that the compound model plays an important role by showing greater advantage in the amount and time of water delivery in Earth-like planets.

Dynamic water patterns change the stability of the collapsed filter conformation of the KcsA K+ channel

PubMed Central

2017-01-01

The selectivity filter of the KcsA K+ channel has two typical conformations—the conductive and the collapsed conformations, respectively. The transition from the conductive to the collapsed filter conformation can represent the process of inactivation that depends on many environmental factors. Water molecules permeating behind the filter can influence the collapsed filter stability. Here we perform the molecular dynamics simulations to study the stability of the collapsed filter of the KcsA K+ channel under the different water patterns. We find that the water patterns are dynamic behind the collapsed filter and the filter stability increases with the increasing number of water molecules. In addition, the stability increases significantly when water molecules distribute uniformly behind the four monomeric filter chains, and the stability is compromised if water molecules only cluster behind one or two adjacent filter chains. The altered filter stabilities thus suggest that the collapsed filter can inactivate gradually under the dynamic water patterns. We also demonstrate how the different water patterns affect the filter recovery from the collapsed conformation. PMID:29049423

Dynamic water patterns change the stability of the collapsed filter conformation of the KcsA K+ channel.

PubMed

Wu, Di

2017-01-01

The selectivity filter of the KcsA K+ channel has two typical conformations-the conductive and the collapsed conformations, respectively. The transition from the conductive to the collapsed filter conformation can represent the process of inactivation that depends on many environmental factors. Water molecules permeating behind the filter can influence the collapsed filter stability. Here we perform the molecular dynamics simulations to study the stability of the collapsed filter of the KcsA K+ channel under the different water patterns. We find that the water patterns are dynamic behind the collapsed filter and the filter stability increases with the increasing number of water molecules. In addition, the stability increases significantly when water molecules distribute uniformly behind the four monomeric filter chains, and the stability is compromised if water molecules only cluster behind one or two adjacent filter chains. The altered filter stabilities thus suggest that the collapsed filter can inactivate gradually under the dynamic water patterns. We also demonstrate how the different water patterns affect the filter recovery from the collapsed conformation.

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

PubMed

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

2017-01-01

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

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

PubMed

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

2013-10-01

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

A COMPOUND MODEL FOR THE ORIGIN OF EARTH'S WATER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Izidoro, A.; Winter, O. C.; De Souza Torres, K.

2013-04-10

One of the most important subjects of debate in the formation of the solar system is the origin of Earth's water. Comets have long been considered as the most likely source of the delivery of water to Earth. However, elemental and isotopic arguments suggest a very small contribution from these objects. Other sources have also been proposed, among which local adsorption of water vapor onto dust grains in the primordial nebula and delivery through planetesimals and planetary embryos have become more prominent. However, no sole source of water provides a satisfactory explanation for Earth's water as a whole. In viewmore » of that, using numerical simulations, we have developed a compound model incorporating both the principal endogenous and exogenous theories, and investigating their implications for terrestrial planet formation and water delivery. Comets are also considered in the final analysis, as it is likely that at least some of Earth's water has cometary origin. We analyze our results comparing two different water distribution models, and complement our study using the D/H ratio, finding possible relative contributions from each source and focusing on planets formed in the habitable zone. We find that the compound model plays an important role by showing greater advantage in the amount and time of water delivery in Earth-like planets.« less

Efficiency of Silver Impregnated Porous Pot (SIPP) Filters for Production of Clean Potable Water

PubMed Central

Mahlangu, Oranso; Mamba, Bhekie; Momba, Maggie

2012-01-01

The Silver Impregnated Porous Pot (SIPP) filter is a product of the Tshwane University of Technology manufactured for the production of safe drinking water at a household (home) level. Two SIPP devices were assessed for the reduction efficiency of chemical contaminants such as calcium, magnesium, iron, arsenic, fluorides and total organic carbon (TOC) as well as microbial contaminants from environmental samples. Turbidity change after filtration, together with correlation between chlorophyll a in the feed water and SIPP’s flow rates were also evaluated in order to give comprehensive guidelines on the quality of intake water that could be filtered through the filter without causing a significant decrease in flow rate. The SIPP filters removed contaminants from environmental water samples as follows: 70% to 92% iron, 36% to 68% calcium, 42% to 82% arsenic, 39% to 98% magnesium, 39% to 95% fluorides, 12% to 35% TOC and 45% to 82% turbidity. The SIPP filters had initial flow rates of 1 L/h to 4 L/h but the flow rates dropped to 0.5 L/h with an increase in cumulative volume of intake water as the filter was used. Turbidity and chemical contaminant reduction rates decreased with accumulating volume of intake water but the filter removed Ca, Fe and Mg to levels that comply with the South African National Standards (SANS 241) and the World Health Organization (WHO) guideline values. However, the SIPP filters cannot produce enough water to satisfy the daily drinking water requirement of a typical household (25 L/p·d). Chlorophyll a was associated with a decrease in the flow rate through the SIPP filters. PMID:23202668

Efficiency of Silver Impregnated Porous Pot (SIPP) filters for production of clean potable water.

PubMed

Mahlangu, Oranso; Mamba, Bhekie; Momba, Maggie

2012-08-24

The Silver Impregnated Porous Pot (SIPP) filter is a product of the Tshwane University of Technology manufactured for the production of safe drinking water at a household (home) level. Two SIPP devices were assessed for the reduction efficiency of chemical contaminants such as calcium, magnesium, iron, arsenic, fluorides and total organic carbon (TOC) as well as microbial contaminants from environmental samples. Turbidity change after filtration, together with correlation between chlorophyll a in the feed water and SIPP's flow rates were also evaluated in order to give comprehensive guidelines on the quality of intake water that could be filtered through the filter without causing a significant decrease in flow rate. The SIPP filters removed contaminants from environmental water samples as follows: 70% to 92% iron, 36% to 68% calcium, 42% to 82% arsenic, 39% to 98% magnesium, 39% to 95% fluorides, 12% to 35% TOC and 45% to 82% turbidity. The SIPP filters had initial flow rates of 1 L/h to 4 L/h but the flow rates dropped to 0.5 L/h with an increase in cumulative volume of intake water as the filter was used. Turbidity and chemical contaminant reduction rates decreased with accumulating volume of intake water but the filter removed Ca, Fe and Mg to levels that comply with the South African National Standards (SANS 241) and the World Health Organization (WHO) guideline values. However, the SIPP filters cannot produce enough water to satisfy the daily drinking water requirement of a typical household (25 L/p·d). Chlorophyll a was associated with a decrease in the flow rate through the SIPP filters.

Near-Earth water sources: Ethics and fairness

NASA Astrophysics Data System (ADS)

Schwartz, James S. J.

2016-08-01

There is a small finite upper bound on the amount of easily accessible water in near-Earth space, including water from C-type NEAs and permanently shadowed lunar craters. Recent estimates put this total at about 3.7 ×1012kg . Given the non-renewable nature of this resource, we should begin thinking carefully about the regulation of near-Earth water sources (NEWS). This paper discusses this issue from an ethical vantage point, and argues that for the foreseeable future, the scientific use of NEWS should be prioritized over other potential uses of NEWS.

Limited effectiveness of household sand filters for removal of arsenic from well water in North Vietnam.

PubMed

Ilmiawati, Cimi; Thang, Nguyen Dinh; Iida, Machiko; Maeda, Masao; Ohnuma, Shoko; Yajima, Ichiro; Ohgami, Nobutaka; Oshino, Reina; Al Hossain, M M Aeorangajeb; Ninomiya, Hiromasa; Kato, Masashi

2016-12-01

Since well water utilized for domestic purposes in the Red River Delta of North Vietnam has been reported to be polluted by arsenic, barium, iron, and manganese, household sand filters consisting of various components are used. Information regarding the effectiveness of various sand filters for removal of the four toxic elements in well water is limited. In this study, arsenic levels in 13/20 of well water samples and 1/7 of tap water samples exceeded World Health Organization (WHO) health-based guideline value for drinking water. Moreover, 2/20, 6/20, and 4/20 of well water samples had levels exceeding the present and previous guideline levels for barium, iron, and manganese, respectively. Levels of iron and manganese, but not arsenic, in well water treated by sand filters were lower than those in untreated water, although previous studies showed that sand filters removed all of those elements from water. A low ratio of iron/arsenic in well water may not be sufficient for efficient removal of arsenic from household sand filters. The levels of barium in well water treated by sand filters, especially a filter composed of sand and charcoal, were significantly lower than those in untreated water. Thus, we demonstrated characteristics of sand filters in North Vietnam.

Detecting Water on Super-Earths Using JAVST

NASA Technical Reports Server (NTRS)

Deming, D.

2010-01-01

Nearby lower train sequence stars host a class of planets known as Super-Earths, that have no analog in our own solar system. Super-Earths are rocky and/or icy planets with masses up to about 10 Earth masses, They are expected to host atmospheres generated by a number of processes including accretion of chondritic material. Water vapor should be a common constituent of super-Earth atmospheres, and may be detectable in transiting super-Earths using transmission spectroscopy during primar y eclipse, and emission spectroscopy at secondary eclipse. I will discuss the prospects for super-Earth atmospheric measurements using JWST.

Galileo multispectral imaging of Earth.

PubMed

Geissler, P; Thompson, W R; Greenberg, R; Moersch, J; McEwen, A; Sagan, C

1995-08-25

Nearly 6000 multispectral images of Earth were acquired by the Galileo spacecraft during its two flybys. The Galileo images offer a unique perspective on our home planet through the spectral capability made possible by four narrowband near-infrared filters, intended for observations of methane in Jupiter's atmosphere, which are not incorporated in any of the currently operating Earth orbital remote sensing systems. Spectral variations due to mineralogy, vegetative cover, and condensed water are effectively mapped by the visible and near-infrared multispectral imagery, showing a wide variety of biological, meteorological, and geological phenomena. Global tectonic and volcanic processes are clearly illustrated by these images, providing a useful basis for comparative planetary geology. Differences between plant species are detected through the narrowband IR filters on Galileo, allowing regional measurements of variation in the "red edge" of chlorophyll and the depth of the 1-micrometer water band, which is diagnostic of leaf moisture content. Although evidence of life is widespread in the Galileo data set, only a single image (at approximately 2 km/pixel) shows geometrization plausibly attributable to our technical civilization. Water vapor can be uniquely imaged in the Galileo 0.73-micrometer band, permitting spectral discrimination of moist and dry clouds with otherwise similar albedo. Surface snow and ice can be readily distinguished from cloud cover by narrowband imaging within the sensitivity range of Galileo's silicon CCD camera. Ice grain size variations can be mapped using the weak H2O absorption at 1 micrometer, a technique which may find important applications in the exploration of the moons of Jupiter. The Galileo images have the potential to make unique contributions to Earth science in the areas of geological, meteorological and biological remote sensing, due to the inclusion of previously untried narrowband IR filters. The vast scale and near global

A post-implementation evaluation of ceramic water filters distributed to tsunami-affected communities in Sri Lanka.

PubMed

Casanova, Lisa M; Walters, Adam; Naghawatte, Ajith; Sobsey, Mark D

2012-06-01

Sri Lanka was devastated by the 2004 Indian Ocean tsunami. During recovery, the Red Cross distributed approximately 12,000 free ceramic water filters. This cross-sectional study was an independent post-implementation assessment of 452 households that received filters, to determine the proportion still using filters, household characteristics associated with use, and quality of household drinking water. The proportion of continued users was high (76%). The most common household water sources were taps or shallow wells. The majority (82%) of users used filtered water for drinking only. Mean filter flow rate was 1.12 L/hr (0.80 L/hr for households with taps and 0.71 for those with wells). Water quality varied by source; households using tap water had source water of high microbial quality. Filters improved water quality, reducing Escherichia coli for households (largely well users) with high levels in their source water. Households were satisfied with filters and are potentially long-term users. To promote sustained use, recovery filter distribution efforts should try to identify households at greatest long-term risk, particularly those who have not moved to safer water sources during recovery. They should be joined with long-term commitment to building supply chains and local production capacity to ensure safe water access.

Characterization of the relationship between ceramic pot filter water production and turbidity in source water.

PubMed

Salvinelli, Carlo; Elmore, A Curt; Reidmeyer, Mary R; Drake, K David; Ahmad, Khaldoun I

2016-11-01

Ceramic pot filters represent a common and effective household water treatment technology in developing countries, but factors impacting water production rate are not well-known. Turbidity of source water may be principal indicator in characterizing the filter's lifetime in terms of water production capacity. A flow rate study was conducted by creating four controlled scenarios with different turbidities, and influent and effluent water samples were tested for total suspended solids and particle size distribution. A relationship between average flow rate and turbidity was identified with a negative linear trend of 50 mLh -1 /NTU. Also, a positive linear relationship was found between the initial flow rate of the filters and average flow rate calculated over the 23 day life of the experiment. Therefore, it was possible to establish a method to estimate the average flow rate given the initial flow rate and the turbidity in the influent water source, and to back calculate the maximum average turbidity that would need to be maintained in order to achieve a specific average flow rate. However, long-term investigations should be conducted to assess how these relationships change over the expected CPF lifetime. CPFs rejected fine suspended particles (below 75 μm), especially particles with diameters between 0.375 μm and 10 μm. The results confirmed that ceramic pot filters are able to effectively reduce turbidity, but pretreatment of influent water should be performed to avoid premature failure. Copyright © 2016 Elsevier Ltd. All rights reserved.

Transport of nanoparticles with dispersant through biofilm coated drinking water sand filters.

PubMed

Li, Zhen; Aly Hassan, Ashraf; Sahle-Demessie, Endalkachew; Sorial, George A

2013-11-01

This article characterizes, experimentally and theoretically, the transport and retention of engineered nanoparticles (NP) through sand filters at drinking water treatment plants (DWTPs) under realistic conditions. The transport of four commonly used NPs (ZnO, CeO2, TiO2, and Ag, with bare surfaces and coating agents) through filter beds filled with sands from either acid washed and calcined, freshly acquired filter media, and used filter media from active filter media, were investigated. The study was conducted using water obtained upstream of the sand filter at DWTP. The results have shown that capping agents have a determinant importance in the colloidal stability and transport of NPs through the different filter media. The presence of the biofilm in used filter media increased adsorption of NPs but its effects in retaining capped NPs was less significant. The data was used to build a mathematical model based on the advection-dispersion equation. The model was used to simulate the performance of a scale-up sand filter and the effects on filtration cycle of traditional sand filtration system used in DWTPs. Published by Elsevier Ltd.

On-farm treatment of dairy soiled water using aerobic woodchip filters.

PubMed

Ruane, Eimear M; Murphy, Paul N C; Healy, Mark G; French, Padraig; Rodgers, Michael

2011-12-15

Dairy soiled water (DSW) is produced on dairy farms through the washing-down of milking parlours and holding areas, and is generally applied to land. However, there is a risk of nutrient loss to surface and ground waters from land application. The aim of this study was to use aerobic woodchip filters to remove organic matter, suspended solids (SS) and nutrients from DSW. This novel treatment method would allow the re-use of the final effluent from the woodchip filters to wash down yards, thereby reducing water usage and environmental risks associated with land spreading. Three replicate 100 m(2) farm-scale woodchip filters, each 1 m deep, were constructed and operated to treat DSW from 300 cows over an 11-month study duration. The filters were loaded at a hydraulic loading rate of 30 L m(-2) d(-1), applied in four doses through a network of pipes on the filter surface. Average influent concentrations of chemical oxygen demand (COD), SS and total nitrogen (TN) of 5750 ± 1441 mg L(-1), 602 ± 303 mg L(-1) and 357 ± 100 mg L(-1), respectively, were reduced by 66, 86 and 57% in the filters. Effluent nutrient concentrations remained relatively stable over the study period, indicating the effectiveness of the filter despite increasing and/or fluctuating influent concentrations. Woodchip filters are a low cost, minimal maintenance treatment system, using a renewable resource that can be easily integrated into existing farm infrastructure. Copyright © 2011 Elsevier Ltd. All rights reserved.

Water inventories on Earth and Mars: Clues to atmosphere formation

NASA Technical Reports Server (NTRS)

Carr, M. H.

1992-01-01

Water is distributed differently on Earth and on Mars and the differences may have implications for the accretion of the two planets and the formation of their atmospheres. The Earth's mantle appears to contain at least several times the water content of the Martian mantle even accounting for differences in plate tectonics. One explanation is that the Earth's surface melted during accretion, as a result of development of a steam atmosphere, thereby allowing impact-devolitalized water at the surface to dissolve into the Earth's interior. In contrast, because of Mars' smaller size and greater distance from the Sun, the Martian surface may not have melted, so that the devolatilized water could not dissolve into the surface. A second possibility is suggested by the siderophile elements in the Earth's mantle, which indicates the Earth acquired a volatile-rich veneer after the core formed. Mars may have acquired a late volatile-rich veneer, but it did not get folded into the interior as with the Earth, but instead remained as a water rich veneer. This perception of Mars with a wet surface but dry interior is consistent with our knowledge of Mars' geologic history.

Rare Earth Element Concentration of Wyoming Thermal Waters Update

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quillinan, Scott; Nye, Charles; Neupane, Hari

Updated version of data generated from rare earth element investigation of produced waters. These data represent major, minor, trace, isotopes, and rare earth element concentrations in geologic formations and water associated with oil and gas production.

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

PubMed

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

2014-01-01

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

Dishwasher For Earth Or Outer Space

NASA Technical Reports Server (NTRS)

Tromble, Jon D.

1991-01-01

Dishwashing machine cleans eating utensils in either Earth gravity or zero gravity of outer space. Cycle consists of three phases: filling, washing, and draining. Rotation of tub creates artificial gravity aiding recirculation of water during washing phase in absence of true gravity. Centrifugal air/water separator helps system function in zero gravity. Self-cleaning filter contains interdigitating blades catching solid debris when water flows between them. Later, blades moved back and forth in scissor-like manner to dislodge debris, removed by backflow of water.

Facile Preparation of Nanostructured, Superhydrophobic Filter Paper for Efficient Water/Oil Separation

PubMed Central

Wang, Jianhua; Wong, Jessica X. H.; Kwok, Honoria; Li, Xiaochun; Yu, Hua-Zhong

2016-01-01

In this paper, we present a facile and cost-effective method to obtain superhydrophobic filter paper and demonstrate its application for efficient water/oil separation. By coupling structurally distinct organosilane precursors (e.g., octadecyltrichlorosilane and methyltrichlorosilane) to paper fibers under controlled reaction conditions, we have formulated a simple, inexpensive, and efficient protocol to achieve a desirable superhydrophobic and superoleophilic surface on conventional filter paper. The silanized superhydrophobic filter paper showed nanostructured morphology and demonstrated great separation efficiency (up to 99.4%) for water/oil mixtures. The modified filter paper is stable in both aqueous solutions and organic solvents, and can be reused multiple times. The present study shows that our newly developed binary silanization is a promising method of modifying cellulose-based materials for practical applications, in particular the treatment of industrial waste water and ecosystem recovery. PMID:26982055

METHOD FOR THE ANALYSIS OF ASBESTOS IN WATER USING MCE FILTERS

EPA Science Inventory

The current Federal Drinking Water Standard makes possible the use of methyl cellulose ester filters rather than the previously proposed Nuclepore™ filter. Updating of the previous counting rules brings them closer to AHERA specifications.

Ranking filter methods for concentrating pathogens in lake water

USDA-ARS?s Scientific Manuscript database

Accurately comparing filtration methods for concentrating waterborne pathogens is difficult because of two important water matrix effects on recovery measurements, the effect on PCR quantification and the effect on filter performance. Regarding the first effect, we show how to create a control water...

Do low-cost ceramic water filters improve water security in rural South Africa?

NASA Astrophysics Data System (ADS)

Lange, Jens; Materne, Tineke; Grüner, Jörg

2016-10-01

This study examined the performance of a low-cost ceramic candle filter system (CCFS) for point of use (POU) drinking water treatment in the village of Hobeni, Eastern Cape Province, South Africa. CCFSs were distributed in Hobeni and a survey was carried out among their users. The performance of 51 CCFSs was evaluated by dip slides and related to human factors. Already after two-thirds of their specified lifetime, none of the distributed CCFSs produced water without distinct contamination, and more than one-third even deteriorated in hygienic water quality. Besides the water source (springs were preferable compared to river or rain water), a high water throughput was the dominant reason for poor CCFS performance. A stepwise laboratory test documented the negative effects of repeated loading and ambient field temperatures. These findings suggest that not every CCFS type per se guarantees improved drinking water security and that the efficiency of low-cost systems should continuously be monitored. For this purpose, dip slides were found to be a cost-efficient alternative to standard laboratory tests. They consistently underestimated microbial counts but can be used by laypersons and hence by the users themselves to assess critical contamination of their filter systems.

Preventing diarrhoea with household ceramic water filters: assessment of a pilot project in Bolivia.

PubMed

Clasen, Thomas F; Brown, Joseph; Collin, Simon M

2006-06-01

In an attempt to prevent diarrhoea in a rural community in central Bolivia, an international non-governmental organization implemented a pilot project to improve drinking water quality using gravity-fed, household-based, ceramic water filters. We assessed the performance of the filters by conducting a five-month randomized controlled trial among all 60 households in the pilot community. Water filters eliminated thermotolerant (faecal) coliforms from almost all intervention households and significantly reduced turbidity, thereby improving water aesthetics. Most importantly, the filters were associated with a 45.3% reduction in prevalence of diarrhoea among the study population (p = 0.02). After adjustment for household clustering and repeated episodes in individuals and controlling for age and baseline diarrhoea, prevalence of diarrhoea among the intervention group was 51% lower than controls, though the protective effect was only borderline significant (OR 0.49, 95% CI: 0.24, 1.01; p = 0.05). A follow-up survey conducted approximately 9 months after deployment of the filters found 67% being used regularly, 13% being used intermittently, and 21% not in use. Water samples from all regularly used filters were free of thermotolerant coliforms.

Local drinking water filters reduce diarrheal disease in Cambodia: a randomized, controlled trial of the ceramic water purifier.

PubMed

Brown, Joe; Sobsey, Mark D; Loomis, Dana

2008-09-01

A randomized, controlled intervention trial of two household-scale drinking water filters was conducted in a rural village in Cambodia. After collecting four weeks of baseline data on household water quality, diarrheal disease, and other data related to water use and handling practices, households were randomly assigned to one of three groups of 60 households: those receiving a ceramic water purifier (CWP), those receiving a second filter employing an iron-rich ceramic (CWP-Fe), and a control group receiving no intervention. Households were followed for 18 weeks post-baseline with biweekly follow-up. Households using either filter reported significantly less diarrheal disease during the study compared with a control group of households without filters as indicated by longitudinal prevalence ratios CWP: 0.51 (95% confidence interval [CI]: 0.41-0.63); CWP-Fe: 0.58 (95% CI: 0.47-0.71), an effect that was observed in all age groups and both sexes after controlling for clustering within households and within individuals over time.

Influence of Household Water Filters on Bacteria Growth and Trace Metals in Tap Water of Doha, Qatar.

PubMed

Nriagu, Jerome; Xi, Chuanwu; Siddique, Azhar; Vincent, Annette; Shomar, Basem

2018-05-29

Deteriorating water quality from aging infrastructure, growing threat of pollution from industrialization and urbanization, and increasing awareness about waterborne diseases are among the factors driving the surge in worldwide use of point-of-entry (POE) and point-of-use (POU) filters. Any adverse influence of such consumer point-of-use systems on quality of water at the tap remains poorly understood, however. We determined the chemical and microbiological changes in municipal water from the point of entry into the household plumbing system until it leaves from the tap in houses equipped with filters. We show that POE/POU devices can induce significant deterioration of the quality of tap water by functioning as traps and reservoirs for sludge, scale, rust, algae or slime deposits which promote microbial growth and biofilm formation in the household water distribution system. With changes in water pressure and physical or chemical disturbance of the plumbing system, the microorganisms and contaminants may be flushed into the tap water. Such changes in quality of household water carry a potential health risk which calls for some introspection in widespread deployment of POE/POU filters in water distribution systems.

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

PubMed

Wagner, Florian B; Nielsen, Peter Borch; Boe-Hansen, Rasmus; Albrechtsen, Hans-Jørgen

2016-05-15

Incomplete nitrification in biological filters during drinking water treatment is problematic, as it compromises drinking water quality. Nitrification problems can be caused by a lack of nutrients for the nitrifying microorganisms. Since copper is an important element in one of the essential enzymes in nitrification, we investigated the effect of copper dosing on nitrification in different biological rapid sand filters treating groundwater. A lab-scale column assay with filter material from a water works demonstrated that addition of a trace metal mixture, including copper, increased ammonium removal compared to a control without addition. Subsequently, another water works was investigated in full-scale, where copper influent concentrations were below 0.05 μg Cu L(-1) and nitrification was incomplete. Copper dosing of less than 5 μg Cu L(-1) to a full-scale filter stimulated ammonium removal within one day, and doubled the filter's removal from 0.22 to 0.46 g NH4-N m(-3) filter material h(-1) within 20 days. The location of ammonium and nitrite oxidation shifted upwards in the filter, with an almost 14-fold increase in ammonium removal rate in the filter's top 10 cm, within 57 days of dosing. To study the persistence of the stimulation, copper was dosed to another filter at the water works for 42 days. After dosing was stopped, nitrification remained complete for at least 238 days. Filter effluent concentrations of up to 1.3 μg Cu L(-1) confirmed that copper fully penetrated the filters, and determination of copper content on filter media revealed a buildup of copper during dosing. The amount of copper stored on filter material gradually decreased after dosing stopped; however at a slower rate than it accumulated. Continuous detection of copper in the filter effluent confirmed a release of copper to the bulk phase. Overall, copper dosing to poorly performing biological rapid sand filters increased ammonium removal rates significantly, achieving effluent

Evidence for primordial water in Earth's deep mantle.

PubMed

Hallis, Lydia J; Huss, Gary R; Nagashima, Kazuhide; Taylor, G Jeffrey; Halldórsson, Sæmundur A; Hilton, David R; Mottl, Michael J; Meech, Karen J

2015-11-13

The hydrogen-isotope [deuterium/hydrogen (D/H)] ratio of Earth can be used to constrain the origin of its water. However, the most accessible reservoir, Earth's oceans, may no longer represent the original (primordial) D/H ratio, owing to changes caused by water cycling between the surface and the interior. Thus, a reservoir completely isolated from surface processes is required to define Earth's original D/H signature. Here we present data for Baffin Island and Icelandic lavas, which suggest that the deep mantle has a low D/H ratio (δD more negative than -218 per mil). Such strongly negative values indicate the existence of a component within Earth's interior that inherited its D/H ratio directly from the protosolar nebula. Copyright © 2015, American Association for the Advancement of Science.

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

PubMed

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

2007-05-01

To describe bottled, filtered, and tap water consumption and fluoride use among pediatric patients; to analyze differences between ethnic and socioeconomic groups; and to describe the frequency of physician-parent discussions regarding water consumption. Convenience sample survey. An urban public health clinic. Parents attending a public health clinic. The primary outcome measure was the prevalence of tap, filtered, and bottled water use. The secondary outcome measures were supplemental fluoride use and the percentage of patients reporting discussions of water consumption with their physician. A total of 216 parents (80.5% Latino and 19.5% non-Latino) completed the survey. Of the parents, 30.1% never drank tap water and 41.2% never gave it to their children. Latino parents were less likely than non-Latino parents to drink tap water (odds ratio, 0.26; 95% confidence interval, 0.10-0.67) and less likely to give tap water to their children (odds ratio, 0.32; 95% confidence interval, 0.15-0.70). More Latinos believed that tap water would make them sick (odds ratio, 5.63; 95% confidence interval, 2.17-14.54). Approximately 40% of children who never drank tap water were not receiving fluoride supplements. Of the lowest-income families (filtered (32.0%) water to their children. Of the parents surveyed, 82.5% reported that their child's physician had never discussed the type of water they should use. Many Latino families avoid drinking tap water because they fear it causes illness. Unnecessary use of bottled and filtered water is costly and may result in adverse dental health outcomes. Physicians should provide guidance to families regarding the safety, low cost, and dental health benefits of drinking tap water.

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - PHYSICAL REMOVAL OF MICROBIOLOGICAL AND PARTICULATE CONTAMINANTS IN DRINKING WATER : SEPARMATIC™ FLUID SYSTEMS DIATOMACEOUS EARTH PRESSURE TYPE FILTER SYSTEM MODEL 12P-2

EPA Science Inventory

The verification test of the SeparmaticTM DE Pressure Type Filter System Model 12P-2 was conducted at the UNH Water Treatment Technology Assistance Center (WTTAC) in Durham, New Hampshire. The source water was finished water from the Arthur Rollins Treatment Plant that was pretr...

Improved virus removal in ceramic depth filters modified with MgO.

PubMed

Michen, Benjamin; Fritsch, Johannes; Aneziris, Christos; Graule, Thomas

2013-02-05

Ceramic filters, working on the depth filtration principle, are known to improve drinking water quality by removing human pathogenic microorganisms from contaminated water. However, these microfilters show no sufficient barrier for viruses having diameters down to 20 nm. Recently, it was shown that the addition of positively charged materials, for example, iron oxyhydroxide, can improve virus removal by adsorption mechanisms. In this work, we modified a common ceramic filter based on diatomaceous earth by introducing a novel virus adsorbent material, magnesium oxyhydroxide, into the filter matrix. Such filters showed an improved removal of about 4-log in regard to bacteriophages MS2 and PhiX174. This is explained with the electrostatic enhanced adsorption approach that is the favorable adsorption of negatively charged viruses onto positively charged patches in an otherwise negatively charged filter matrix. Furthermore, we provide theoretical evidence applying calculations according to Derjaguin-Landau-Verwey-Overbeek theory to strengthen our experimental results. However, modified filters showed a significant variance in virus removal efficiency over the course of long-term filtration experiments with virus removal increasing with filter operation time (or filter aging). This is explained by transformational changes of MgO in the filter upon contact with water. It also demonstrates that filter history is of great concern when filters working on the adsorption principles are evaluated in regard to their retention performance as their surface characteristics may alter with use.

Change in Water Cycle- Important Issue on Climate Earth System

NASA Astrophysics Data System (ADS)

Singh, Pratik

Change in Water Cycle- Important Issue on Climate Earth System PRATIK KUMAR SINGH1 1BALDEVRAM MIRDHA INSTITUTE OF TECHNOLOGY,JAIPUR (RAJASTHAN) ,INDIA Water is everywhere on Earth and is the only known substance that can naturally exist as a gas, liquid, and solid within the relatively small range of air temperatures and pressures found at the Earth's surface.Changes in the hydrological cycle as a consequence of climate and land use drivers are expected to play a central role in governing a vast range of environmental impacts.Earth's climate will undergo changes in response to natural variability, including solar variability, and to increasing concentrations of green house gases and aerosols.Further more, agreement is widespread that these changes may profoundly affect atmospheric water vapor concentrations, clouds and precipitation patterns.As we know that ,a warmer climate, directly leading to increased evaporation, may well accelerate the hydrological cycle, resulting in an increase in the amount of moisture circulating through the atmosphere.The Changing Water Cycle programmer will develop an integrated, quantitative understanding of the changes taking place in the global water cycle, involving all components of the earth system, improving predictions for the next few decades of regional precipitation, evapotranspiration, soil moisture, hydrological storage and fluxes.The hydrological cycle involves evaporation, transpiration, condensation, precipitation, and runoff. NASA's Aqua satellite will monitor many aspects of the role of water in the Earth's systems, and will do so at spatial and temporal scales appropriate to foster a more detailed understanding of each of the processes that contribute to the hydrological cycle. These data and the analyses of them will nurture the development and refinement of hydrological process models and a corresponding improvement in regional and global climate models, with a direct anticipated benefit of more accurate weather and

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

NASA Astrophysics Data System (ADS)

Allred, B. J.

2007-12-01

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

Microbial community in a full-scale drinking water biosand filter.

PubMed

Feng, Shuo; Chen, Chao; Wang, Qingfeng; Yang, Zhiyu; Zhang, Xiaojian; Xie, Shuguang

2013-04-01

To remove turbidity and minimize microbiological risks, rapid sand filtration is one of main drinking water treatment processes in the world. However, after a long-term operation, sand particles will be colonized by microorganisms which can remove biodegradable organic matters and nitrogen compounds. In this study, 16S rRNA gene clone library analysis was applied to characterize the microbial community in a full-scale biosand filter used for drinking water treatment. The results indicate that phylum Nitrospirae and class Alphaproteobacteria were the dominant bacterial groups in the biosand sample collected from the upper filter layer. The dominance of Sphingomonas species might pose a microbiological risk. This work could provide some new insights into microbial community in drinking water biofilter.

A New Electropositive Filter for Concentrating Enterovirus and Norovirus from Large Volumes of Water - MCEARD

EPA Science Inventory

The detection of enteric viruses in environmental water usually requires the concentration of viruses from large volumes of water. The 1MDS electropositive filter is commonly used for concentrating enteric viruses from water but unfortunately these filters are not cost-effective...

Efficiency of several micro-fiber glass filters for recovery of poliovirus from tape water.

PubMed Central

Payment, P; Trudel, M

1979-01-01

Micro-fiber glass filters from Gelman, Filterite, Johns-Manville, and Whatman were compared with Millipore membrane filters on the basis of their virus adsorbancy, flow rate, clogging resistance, and virus concentration efficiency by using tap water at 2 nephelometric turbidity units. As virus adsorbants the Johns-Manville D39, Filterite 0.25-micron, Filterite 0.45-micron, and Millipore 0.45-micron filters were the most efficient, retaining more than 99% of the added virus in water at pH 3.5 and 0.0005 M aluminum chloride. The Johns-Manville D79 and D49 filters retained 92 and 96% of the virus, respectively, whereas the Whatman GF-D, Whatman GF-F, Gelman A-E, and Millipore AP-20 filters retained only 28, 78, 56, and 34% of the virus, respectively. The best flow rate and clogging resistance were obtained with the Johns-Manville D79 filter or with this filter acting as a prefilter to the Johns-Manville D49, Johns-Manville D39, or Filterite 0.45-micron filter. Finally, poliovirus experimentally seeded in 20 liters of tape water was recovered from Johns-Manville D79-Johns-Manville D39 or Johns-Manville D79-Filterite 0.45 micron 142-mm filter combinations was a efficiencies of 86 and 85%, respectively. PMID:231414

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

PubMed

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

2017-06-01

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

The Military Efficacy of Individual Water Purification Filters.

DTIC Science & Technology

1990-12-01

criteria. ’t *.;as a.Lso serv ea that the KPF units grew opportunistic Pseudomonas sp . on the oroduct water side of the filters, which could have a...small pathogenic protozoan cysts such as Cryptospor-dium parvum, Giardia lamblia, and Entamoeba coli, from water over the effective use life of the...of heterotrophic bacteria such as Pseudoronas sP , Flavobacterium Sp , and other potentially harmfui organisms inside of the units. Enteric viruses are

Slow-sand water filter: Design, implementation, accessibility and sustainability in developing countries

PubMed Central

Clark, Peter A.; Pinedo, Catalina Arango; Fadus, Matthew; Capuzzi, Stephen

2012-01-01

Summary The need for clean water has risen exponentially over the globe. Millions of people are affected daily by a lack of clean water, especially women and children, as much of their day is dedicated to collecting water. The global water crisis not only has severe medical implications, but social, political, and economic consequences as well. The Institute of Catholic Bioethics at Saint Joseph’s University has recognized this, and has designed a slow-sand water filter that is accessible, cost-effective, and sustainable. Through the implementation of the Institute’s slow-sand water filter and the utilization of microfinancing services, developing countries will not only have access to clean, drinkable water, but will also have the opportunity to break out of a devastating cycle of poverty. PMID:22739748

Mars residual north polar cap - Earth-based spectroscopic confirmation of water ice as a major constituent and evidence for hydrated minerals

NASA Technical Reports Server (NTRS)

Clark, R. N.; Mccord, T. B.

1982-01-01

A description is presented of new earth-based reflectance spectra of the Martian north residual polar cap. The spectra indicate that the composition is at least mostly water ice plus another component with a 'gray' reflectance. The other minerals in the ice cap appear to be hydrated. The data were obtained with a cooled circular variable filter spectrometer on February 20, 1978, using the 2.2-m telescope on Mauna Kea, Hawaii. It is pointed out that the identification of water ice in the north polar cap alone does not indicate that water makes up all or even most of the bulk of the cap. Kieffer (1970) has shown that a small amount of water will mask the spectral features of CO2.

Metal oxide/hydroxide-coated dual-media filter for simultaneous removal of bacteria and heavy metals from natural waters.

PubMed

Ahammed, M Mansoor; Meera, V

2010-09-15

The present study was conducted to compare the performance of a dual-media filter consisting of manganese oxide-coated (MOCS) and iron hydroxide-coated sand (IOCS) with that of IOCS filter and uncoated sand filter in treating water contaminated by microorganisms, heavy metals and turbidity with a view to its use in simple household water purification devices in developing countries. Long-duration column tests were conducted using two natural waters namely, roof-harvested rainwater and canal water. Performance of the filters showed that dual-media filter was more efficient in removing bacteria and heavy metals compared to IOCS filter, while uncoated sand filter showed very poor performance. The average effluent levels for dual-media filter when tested with rainwater were: turbidity 1.0+/-0.1 NTU; total coliforms 3+/-2 MPN/100 mL; heterotrophic plate count 170+/-20 CFU/mL; zinc 0.06+/-0.01 mg/L, while that for IOCS filter were: turbidity 1.0+/-0.1 NTU; total coliforms 4+/-2 MPN/100 mL; heterotrophic plate count 181+/-37 CFU/mL; zinc 0.20+/-0.07 mg/L. Similar results were obtained for canal water also. Up to 900 bed volumes (BV) could be treated without affecting the efficiency in the case of rainwater, while the filter operation had to be terminated after 500 BV due to excessive headloss in the case of canal water. The study thus showed the potential of the dual-media for use in low-cost household water filters for purification of natural waters. Copyright 2010 Elsevier B.V. All rights reserved.

Filter Membrane Effects on Water-Extractable Phosphorus Concentrations from Soil.

PubMed

Norby, Jessica; Strawn, Daniel; Brooks, Erin

2018-03-01

To accurately assess P concentrations in soil extracts, standard laboratory practices for monitoring P concentrations are needed. Water-extractable P is a common analytical test to determine P availability for leaching from soils, and it is used to determine best management practices. Most P analytical tests require filtration through a filter membrane with 0.45-μm pore size to distinguish between particulate and dissolved P species. However, filter membrane type is rarely specified in method protocols, and many different types of membranes are available. In this study, three common filter membrane materials (polyether sulfone, nylon, and nitrocellulose), all with 0.45-μm pore sizes, were tested for analytical differences in total P concentrations and dissolved reactive P (DRP) concentrations in water extracts from six soils sampled from two regions. Three of the extracts from the six soil samples had different total P concentrations for all three membrane types. The other three soil extracts had significantly different total P results from at least one filter membrane type. Total P concentration differences were as great as 35%. The DRP concentrations in the extracts were dependent on filter type in five of the six soil types. Results from this research show that filter membrane type is an important parameter that affects concentrations of total P and DRP from soil extracts. Thus, membrane type should be specified in soil extraction protocols. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Earth-Science Research for Addressing the Water-Energy Nexus

NASA Astrophysics Data System (ADS)

Healy, R. W.; Alley, W. M.; Engle, M.; McMahon, P. B.; Bales, J. D.

2013-12-01

In the coming decades, the United States will face two significant and sometimes competing challenges: preserving sustainable supplies of fresh water for humans and ecosystems, and ensuring available sources of energy. This presentation provides an overview of the earth-science data collection and research needed to address these challenges. Uncertainty limits our understanding of many aspects of the water-energy nexus. These aspects include availability of water, water requirements for energy development, energy requirements for treating and delivering fresh water, effects of emerging energy development technologies on water quality and quantity, and effects of future climates and land use on water and energy needs. Uncertainties can be reduced with an integrated approach that includes assessments of water availability and energy resources; monitoring of surface water and groundwater quantity and quality, water use, and energy use; research on impacts of energy waste streams, hydraulic fracturing, and other fuel-extraction processes on water quality; and research on the viability and environmental footprint of new technologies such as carbon capture and sequestration and conversion of cellulosic material to ethanol. Planning for water and energy development requires consideration of factors such as economics, population trends, human health, and societal values; however, sound resource management must be grounded on a clear understanding of the earth-science aspects of the water-energy nexus. Information gained from an earth-science data-collection and research program can improve our understanding of water and energy issues and lay the ground work for informed resource management.

Novel approach for modifying microporous filters for virus concentration from water.

PubMed Central

Preston, D R; Vasudevan, T V; Bitton, G; Farrah, S R; Morel, J L

1988-01-01

Electronegative microporous filters composed of epoxyfiberglass (Filterite) were treated with cationic polymers to enhance their virus-adsorbing properties. This novel and inexpensive approach to microporous filter modification entails soaking filters in an aqueous solution of a cationic polymer such as polyethyleneimine (PEI) for 2 h at room temperature and then allowing the filters to air dry overnight on absorbent paper towels. PEI-treated filters were evaluated for coliphage (MS2, T2, and phi X174) and enterovirus (poliovirus type 1 and coxsackievirus type B5) adsorption from buffer at pH 3.5 to 9.0 and for indigenous coliphages from unchlorinated secondary effluent at ambient pH. Adsorbed viruses were recovered with 3% beef extract (pH 9). Several other cationic polymers were used to modify epoxyfiberglass filters and were evaluated for their ability to concentrate viruses from water. Zeta potentials of disrupted filter material indicated that electronegative epoxyfiberglass filters were made more electropositive when treated with cationic polymers. In general, epoxyfiberglass filters treated with cationic polymers were found to adsorb a greater percentage of coliphages and enteroviruses than were untreated filters. PMID:2843091

Estimating the water budget for a peat filter treating septic tank effluent in the field

NASA Astrophysics Data System (ADS)

Van Geel, Paul J.; Parker, Wayne J.

2003-02-01

The use of peat as a filter medium for the treatment of a variety of liquid and gas waste streams has increased over the past decade. Peat has been used as an alternate treatment medium to treat septic tank effluent (STE) from domestic and small communal systems. Very little research has been completed to study the hydraulics and water budget of a peat filter operating in the field. This study evaluated the water budget of a peat filter operating at an elementary school near Ottawa, Canada. The peat filter was instrumented with tensiometers to measure the pore water pressures within the filter and a weather station to collect weather data required to estimate potential evapotranspiration. A one-dimensional unsaturated flow model, SoilCover, was calibrated using the pressure data and weather data collected in the field. The calibrated model was use to estimate the water budget for the filter operating with and without STE loading. The calibrated model predicted that the annual precipitation exceeded evapotranspiration for both scenarios. For the filter treating 50 mm/day of STE, there was a slight dilution due to the infiltration resulting in a net dilution factor of 0.97 (loading divided by the loading plus infiltration). The largest rainfall event of 49.9 mm resulted in a dilution factor of approximately 0.87, which corresponded to an approximate decrease in the hydraulic retention time (HRT) of between 12 and 33% depending on the calculation used to determine the HRT. When the filter does not receive STE, the precipitation exceeds evapotranspiration and hence the filter should not dry out when the filter is not in use.

Water: Communicator In Moon-Earth Relationships

NASA Astrophysics Data System (ADS)

Davis, Joan S.

The Moon's myriad effects upon Earth have been objects of fascination, and subjects for literary works and scientific speculation throughout history. Although many of Moon's influences upon Earth involve water, tidal movement is clearly the most readily associated effect. While very obvious, it however represents only one of a multitude of ways in which lunar forces effect this planet, and all life upon it. Much less apparent, though essential for all of life, is the wide spectrum of subtle fluctuating influences upon the water in the cells of living systems. Water's capacity to respond to extremely subtle changes in physical influences (such as gravitational fields), as associated with Moon phases (N.B. also with planetary constellations and sunspot activity), enables it to communicate such inputs to living systems. The periodicity of changes in natural systems has been of interest to man throughout history. However, only in more recent times has insight into water's behaviour led to its being recognised as a link between the periodicities seen in abiotic (Moon and other planetary) systems and biotic systems. Particular attention has long been paid to systematic fluctuations in agriculture and forestry: Different growth patterns are observed in connection with the Moon phases (and zodiac constellations) at planting time; different characteristics (e.g., fire resistance, pliability, firmness, etc.) of wood are seen in trees harvested at different phases and constellations. . The usefulness of such correlations has influenced planting and harvesting patterns in more traditional-oriented agriculture and forestry. Its acceptance by science has, however, been long in coming. The case similar, as regards physiological fluctuations observed in the medical field. A documented case in point is the correlation between the Moon-phase and risk of hemorrhage during surgery: This is one of many observations on periodicity in body functions, which deserve more research attention

Global water cycle and Earth's thermal evolution

NASA Astrophysics Data System (ADS)

Franck, Siegfried; Bounama, Christine

2001-09-01

Convergent margin processes play an important role in the distribution of terrestrial volatile species. During subduction processes volatiles are filtered from the subducting package and are restricted to return to the mantle. Water is the most abundant volatile and plays an important role in these processes. There is a number of geochemical investigations to determine the subduction, regassing, and recycling fluxes as well as the regassing ratio of water. The latter describes the partition of subducting water by water that is regassed into the mantle and water that is returned to the surface in arc magmas. Here we present a geophysical-based modelling approach for the calculation of such fluxes and ratios in order to compare them with the geochemical data. In order to assess the recent values and the evolution of the subduction, regassing, and the recycling flux a simple parameterized thermal convection model with a water-dependent rheology and a constant continental growth model is applied. To test the sensitivity of the results different continental growth models were applied and the total amount of water in the system was varied as well as the initial distribution of water in the reservoirs. According to our estimations a value of 0.31 for the time independent regassing ratio of water, RH 2O , is an acceptable upper bound. Lower values of RH 2O give larger water reservoirs on the surface compared to the recent situation. Larger values of RH 2O suggest smaller surface reservoirs of water and, therefore, seem to be unlikely. The model results show a relatively stable value for the regassing ratio of 0.31 by varying the initial conditions of the water distribution in the reservoirs (which are pretty much unknown at the present moment). But RH 2O is very sensitive towards the total amount of water in the system. Altering the value of four ocean masses to ten we get values for the regassing ratio from 0.31 to 0.89. Nevertheless, as a result of all numerical

Rotating carbon nanotube membrane filter for water desalination

NASA Astrophysics Data System (ADS)

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

2016-05-01

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

Rotating carbon nanotube membrane filter for water desalination

PubMed Central

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

2016-01-01

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

Microbial survey of a full-scale, biologically active filter for treatment of drinking water.

PubMed

White, Colin P; Debry, Ronald W; Lytle, Darren A

2012-09-01

The microbial community of a full-scale, biologically active drinking water filter was surveyed using molecular techniques. Nitrosomonas, Nitrospira, Sphingomonadales, and Rhizobiales dominated the clone libraries. The results elucidate the microbial ecology of biological filters and demonstrate that biological treatment of drinking water should be considered a viable alternative to physicochemical methods.

Microbiological Characterization of the International Space Station Water Processor Assembly External Filter Assembly S/N 01

NASA Technical Reports Server (NTRS)

Weir, Natalee; Wilson, Mark; Yoets, Airan; Yoets, Airan; Molina, Thomas; Bruce, Rebekah; Sitler, Glenn; Carter, Layne

2012-01-01

The External Filter Assembly (EFA) S/N 01 is a mesh screen filter with a pore size of approximately 300 micron that was installed in the International Space Station (ISS) Water Processor Assembly (WPA) between the Waste Tank and the Mostly Liquid Separator (MLS) on February 11, 2010 to protect clearances in the MLS solenoid valve SV_1121_3. A removal & replacement of the EFA Filter was performed on March 22, 2011 in response to increasing pressure across the Waste Tank solenoid valve SV_1121_1 and the EFA Filter. The EFA Filter was returned on ULF6 and received in the Boeing Huntsville Laboratory on June 13, 2011. The filter was aseptically removed from the housing, and the residual water was collected for enumeration and identification of bacteria and fungi. Swab samples of the filter surface were also collected for microbiological enumeration and identification. Sample analyses were performed by Boeing Huntsville Laboratory and NASA Johnson Space Center Microbiology for comparison. Photographic documentation of the EFA filter was performed using a stereo microscope and environmental scanning electron microscope. This paper characterizes the amount and types of microorganisms on the filter surface and in the residual water from the filter housing following 1 year of utilization in the ISS WPA.

Microbial Survey of a Full-Scale, Biologically Active Filter for Treatment of Drinking Water

PubMed Central

DeBry, Ronald W.; Lytle, Darren A.

2012-01-01

The microbial community of a full-scale, biologically active drinking water filter was surveyed using molecular techniques. Nitrosomonas, Nitrospira, Sphingomonadales, and Rhizobiales dominated the clone libraries. The results elucidate the microbial ecology of biological filters and demonstrate that biological treatment of drinking water should be considered a viable alternative to physicochemical methods. PMID:22752177

Recovery and separation of rare earth elements using columns loaded with DNA-filter hybrid.

PubMed

Takahashi, Yoshio; Kondo, Kazuhiro; Miyaji, Asami; Umeo, Miyuki; Honma, Tetsuo; Asaoka, Satoshi

2012-01-01

Given that the supply of several rare earth elements (REEs) is sometimes limited, recycling REEs used in various advanced materials, such as Nd magnets, is important for realizing efficient use of REE resources. In the present work, the feasibility of using DNA for REE recovery and separation was examined, along with the identification of the binding site of REEs in DNA. In particular, a DNA-cellulose filter paper hybrid was prepared so that DNA-based materials can be used for the separation of REEs using columns loaded with DNA. N,N'-Disuccinimidyl was used as a cross-linker reagent for the fixation of DNA onto a fibrous cellulose filter. The results showed that (i) the DNA-filter hybrid has a sufficiently high affinity to adsorb REEs; (ii) the adsorption capacity was 0.182 mg/g for Nd; and (iii) the affinity of REEs for DNA was stronger for REEs with larger atomic numbers. The difference of the affinity among REEs in the third result was compared with the adsorption patterns of REEs discussed in the literature. The comparison suggests that phosphate in the DNA-filter paper hybrid was responsible for REE adsorption onto the hybrid. The results were supported by the Nd, Dy, and Lu L(III)-edge EXAFS; the REE-P shell was identified for the second neighboring atom, showing the importance of the phosphate site as REE binding sites. The difference in the affinity among REEs suggest that group separation of REEs (such as La, Ce, (Pr and Nd), (Ho, Dy, and Er), (Tb and Gd), (Sm, Eu), Tm, Yb, and Lu) is possible, although complete isolation of each REE from a solution containing all REEs may be difficult. For practical applications, Nd and Fe(III) were successfully separated from a synthetic solution of Nd magnet waste using columns loaded with the DNA-filter hybrid.

The Use of Daily Geodetic UT1 and LOD Data in the Optimal Estimation of UT1 and LOD With the JPL Kalman Earth Orientation Filter

NASA Technical Reports Server (NTRS)

Freedman, A. P.; Steppe, J. A.

1995-01-01

The Jet Propulsion Laboratory Kalman Earth Orientation Filter (KEOF) uses several of the Earth rotation data sets available to generate optimally interpolated UT1 and LOD series to support spacecraft navigation. This paper compares use of various data sets within KEOF.

A Kalman filter for a two-dimensional shallow-water model

NASA Technical Reports Server (NTRS)

Parrish, D. F.; Cohn, S. E.

1985-01-01

A two-dimensional Kalman filter is described for data assimilation for making weather forecasts. The filter is regarded as superior to the optimal interpolation method because the filter determines the forecast error covariance matrix exactly instead of using an approximation. A generalized time step is defined which includes expressions for one time step of the forecast model, the error covariance matrix, the gain matrix, and the evolution of the covariance matrix. Subsequent time steps are achieved by quantifying the forecast variables or employing a linear extrapolation from a current variable set, assuming the forecast dynamics are linear. Calculations for the evolution of the error covariance matrix are banded, i.e., are performed only with the elements significantly different from zero. Experimental results are provided from an application of the filter to a shallow-water simulation covering a 6000 x 6000 km grid.

Water Filter Provision and Home-Based Filter Reinforcement Reduce Diarrhea in Kenyan HIV-Infected Adults and Their Household Members

PubMed Central

Pavlinac, Patricia B.; Naulikha, Jaqueline M.; Chaba, Linda; Kimani, Naomi; Sangaré, Laura R.; Yuhas, Krista; Singa, Benson O.; John-Stewart, Grace; Walson, Judd L.

2014-01-01

Among human immunodeficiency virus (HIV) -infected adults and children in Africa, diarrheal disease remains a major cause of morbidity and mortality. We evaluated the effectiveness of provision and home-based reinforcement of a point-of-use water filtration device to reduce diarrhea among 361 HIV-infected adults in western Kenya by comparing prevalence of self-reported diarrhea before and after these interventions. After provision of the filter, 8.7% of participants reported diarrhea compared with 17.2% in the 3 months before filter provision (odds ratio [OR] = 0.39, 95% confidence interval [95% CI] = 0.23–0.66, P < 0.001). The association was similar among 231 participants who were already taking daily cotrimoxazole prophylaxis before being given a filter (OR = 0.47, 95% CI = 0.25–0.88, P = 0.019). Educational reinforcement was also associated with a modest reduction in self-reported diarrhea (OR = 0.50, 95% CI = 0.20–0.99, P = 0.047). Provision and reinforcement of water filters may confer significant benefit in reducing diarrhea among HIV-infected persons, even when cotrimoxazole prophylaxis is already being used. PMID:24842881

Transforming Water Management: an Emerging Promise of Integrated Earth Observations

NASA Astrophysics Data System (ADS)

Lawford, R. G.

2011-12-01

Throughout its history, civilization has relied on technology to facilitate many of its advances. New innovations and technologies have often provided strategic advantages that have led to transformations in institutions, economies and ultimately societies. Observational and information technologies are leading to significant developments in the water sector. After a brief introduction tracing the role of observational technologies in the areas of hydrology and water cycle science, this talk explores the existing and potential contributions of remote sensing data in water resource management around the world. In particular, it outlines the steps being undertaken by the Group on Earth Observations (GEO) and its Water Task to facilitate capacity building efforts in water management using Earth Observations in Asia, Africa and Latin and Caribbean America. Success stories on the benefits of using Earth Observations and applying GEO principles are provided. While GEO and its capacity building efforts are contributing to the transformation of water management through interoperability, data sharing, and capacity building, the full potential of these contributions has not been fully realized because impediments and challenges still remain.

Iron-Anode Enhanced Sand Filter for Arsenic Removal from Tube Well Water.

PubMed

Xie, Shiwei; Yuan, Songhu; Liao, Peng; Tong, Man; Gan, Yiqun; Wang, Yanxin

2017-01-17

Sand filters are widely used for well water purification in endemic arsenicosis areas, but arsenic (As) removal is difficult at low intrinsic iron concentrations. This work developed an enhanced sand filter by electrochemically generated Fe(II) from an iron anode. The efficiency of As removal was tested in an arsenic burdened region in the Jianghan Plain, central China. By controlling a current of 0.6 A and a flow rate of about 12 L/h, the filter removed total As in the tube well water from 196 to 472 μg/L to below 10 μg/L, whereas the residual As was about 110 μg/L without electricity. Adsorption and subsequent oxidation on the surface of Fe(III) precipitates are the main processes controlling the removals of As and Fe. During a 30-day intermittent operation, both effluent As concentration and electrical energy consumption decreased progressively. Although filter clogging was observed, it can be alleviated by replacing the top layer of sand. Our findings suggest that dosing Fe(II) by an iron anode is an effective means to enhance As removal in a sand filter.

Micron-pore-sized metallic filter tube membranes for filtration of particulates and water purification.

PubMed

Phelps, T J; Palumbo, A V; Bischoff, B L; Miller, C J; Fagan, L A; McNeilly, M S; Judkins, R R

2008-07-01

Robust filtering techniques capable of efficiently removing particulates and biological agents from water or air suffer from plugging, poor rejuvenation, low permeance, and high backpressure. Operational characteristics of pressure-driven separations are in part controlled by the membrane pore size, charge of particulates, transmembrane pressure and the requirement for sufficient water flux to overcome fouling. With long term use filters decline in permeance due to filter-cake plugging of pores, fouling, or filter deterioration. Though metallic filter tube development at ORNL has focused almost exclusively on gas separations, a small study examined the applicability of these membranes for tangential filtering of aqueous suspensions of bacterial-sized particles. A mixture of fluorescent polystyrene microspheres ranging in size from 0.5 to 6 microm in diameter simulated microorganisms in filtration studies. Compared to a commercial filter, the ORNL 0.6 microm filter averaged approximately 10-fold greater filtration efficiency of the small particles, several-fold greater permeance after considerable use and it returned to approximately 85% of the initial flow upon backflushing versus 30% for the commercial filter. After filtering several liters of the particle-containing suspension, the ORNL composite filter still exhibited greater than 50% of its initial permeance while the commercial filter had decreased to less than 20%. When considering a greater filtration efficiency, greater permeance per unit mass, greater percentage of rejuvenation upon backflushing (up to 3-fold), and likely greater performance with extended use, the ORNL 0.6 microm filters can potentially outperform the commercial filter by factors of 100-1,000 fold.

Use of a Filter Cartridge for Filtration of Water Samples and Extraction of Environmental DNA.

PubMed

Miya, Masaki; Minamoto, Toshifumi; Yamanaka, Hiroki; Oka, Shin-Ichiro; Sato, Keiichi; Yamamoto, Satoshi; Sado, Tetsuya; Doi, Hideyuki

2016-11-25

Recent studies demonstrated the use of environmental DNA (eDNA) from fishes to be appropriate as a non-invasive monitoring tool. Most of these studies employed disk fiber filters to collect eDNA from water samples, although a number of microbial studies in aquatic environments have employed filter cartridges, because the cartridge has the advantage of accommodating large water volumes and of overall ease of use. Here we provide a protocol for filtration of water samples using the filter cartridge and extraction of eDNA from the filter without having to cut open the housing. The main portions of this protocol consists of 1) filtration of water samples (water volumes ≤4 L or >4 L); (2) extraction of DNA on the filter using a roller shaker placed in a preheated incubator; and (3) purification of DNA using a commercial kit. With the use of this and previously-used protocols, we perform metabarcoding analysis of eDNA taken from a huge aquarium tank (7,500 m 3 ) with known species composition, and show the number of detected species per library from the two protocols as the representative results. This protocol has been developed for metabarcoding eDNA from fishes, but is also applicable to eDNA from other organisms.

The fate of water within Earth and super-Earths and implications for plate tectonics

PubMed Central

2017-01-01

The Earth is likely to have acquired most of its water during accretion. Internal heat of planetesimals by short-lived radioisotopes would have caused some water loss, but impacts into planetesimals were insufficiently energetic to produce further drying. Water is thought to be critical for the development of plate tectonics, because it lowers viscosities in the asthenosphere, enabling subduction. The following issue persists: if water is necessary for plate tectonics, but subduction itself hydrates the upper mantle, how is the upper mantle initially hydrated? The giant impacts of late accretion created magma lakes and oceans, which degassed during solidification to produce a heavy atmosphere. However, some water would have remained in the mantle, trapped within crystallographic defects in nominally anhydrous minerals. In this paper, we present models demonstrating that processes associated with magma ocean solidification and overturn may segregate sufficient quantities of water within the upper mantle to induce partial melting and produce a damp asthenosphere, thereby facilitating plate tectonics and, in turn, the habitability of Earth-like extrasolar planets. This article is part of the themed issue ‘The origin, history and role of water in the evolution of the inner Solar System’. PMID:28416729

The fate of water within Earth and super-Earths and implications for plate tectonics.

PubMed

Tikoo, Sonia M; Elkins-Tanton, Linda T

2017-05-28

The Earth is likely to have acquired most of its water during accretion. Internal heat of planetesimals by short-lived radioisotopes would have caused some water loss, but impacts into planetesimals were insufficiently energetic to produce further drying. Water is thought to be critical for the development of plate tectonics, because it lowers viscosities in the asthenosphere, enabling subduction. The following issue persists: if water is necessary for plate tectonics, but subduction itself hydrates the upper mantle, how is the upper mantle initially hydrated? The giant impacts of late accretion created magma lakes and oceans, which degassed during solidification to produce a heavy atmosphere. However, some water would have remained in the mantle, trapped within crystallographic defects in nominally anhydrous minerals. In this paper, we present models demonstrating that processes associated with magma ocean solidification and overturn may segregate sufficient quantities of water within the upper mantle to induce partial melting and produce a damp asthenosphere, thereby facilitating plate tectonics and, in turn, the habitability of Earth-like extrasolar planets.This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'. © 2017 The Authors.

Reducing diarrhea through the use of household-based ceramic water filters: a randomized, controlled trial in rural Bolivia.

PubMed

Clasen, Thomas F; Brown, Joseph; Collin, Simon; Suntura, Oscar; Cairncross, Sandy

2004-06-01

Ceramic water filters have been identified as one of the most promising and accessible technologies for treating water at the household level. In a six-month trial, water filters were distributed randomly to half of the 50 participating households in a rural community in Bolivia; the remaining households continued to use customary water handling practices and served as controls. In four rounds of sampling following distribution of the filters, 100% of the 96 water samples from the filter households were free of thermotolerant coliforms compared with 15.5% of the control household samples. Diarrheal disease risk for individuals in intervention households was 70% lower than for controls (95% confidence interval [CI] = 53-80%; P < 0.001). For children less than five years old, the reduction in risk was 83% (95% CI = 51-94%; P < 0.001). These results show that affordable ceramic water filters enable low-income households to treat and maintain the microbiologic quality of their drinking water.

Assessment of nitrification in groundwater filters for drinking water production by qPCR and activity measurement.

PubMed

de Vet, W W J M; Kleerebezem, R; van der Wielen, P W J J; Rietveld, L C; van Loosdrecht, M C M

2011-07-01

In groundwater treatment for drinking water production, the causes of nitrification problems and the effectiveness of process optimization in rapid sand filters are often not clear. To assess both issues, the performance of a full-scale groundwater filter with nitrification problems and another filter with complete nitrification and pretreatment by subsurface aeration was monitored over nine months. Quantitative real-time polymerase chain reaction (qPCR) targeting the amoA gene of bacteria and archaea and activity measurements of ammonia oxidation were used to regularly evaluate water and filter sand samples. Results demonstrated that subsurface aeration stimulated the growth of ammonia-oxidizing prokaryotes (AOP) in the aquifer. Cell balances, using qPCR counts of AOP for each filter, showed that the inoculated AOP numbers from the aquifer were marginal compared with AOP numbers detected in the filter. Excessive washout of AOP was not observed and did not cause the nitrification problems. Ammonia-oxidizing archaea grew in both filters, but only in low numbers compared to bacteria. The cell-specific nitrification rate in the sand and backwash water samples was high for the subsurface aerated filter, but systematically much lower for the filter with nitrification problems. From this, we conclude that incomplete nitrification was caused by nutrient limitation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Safe household water treatment and storage using ceramic drip filters: a randomised controlled trial in Bolivia.

PubMed

Clasen, T; Brown, J; Suntura, O; Collin, S

2004-01-01

A randomised controlled field trial was conducted to evaluate the effectiveness of ceramic drip filters to improve the microbiological quality of drinking water in a low-income community in rural Bolivia. In four rounds of water sampling over five months, 100% of the samples were free of thermotolerant (faecal) coliforms (TTC) compared to an arithmetic mean TTC count of 1517, 406, 167 and 245 among control households which continued to use their customary sources of drinking water. The filter systems produced water that consistently met WHO drinking-water standards despite levels of turbidity that presented a challenge to other low-cost POU treatment methods. The filter systems also demonstrated an ability to maintain the high quality of the treated water against subsequent re-contamination in the home.

Water cycling between ocean and mantle: Super-earths need not be waterworlds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cowan, Nicolas B.; Abbot, Dorian S., E-mail: n-cowan@northwestern.edu

2014-01-20

Large terrestrial planets are expected to have muted topography and deep oceans, implying that most super-Earths should be entirely covered in water, so-called waterworlds. This is important because waterworlds lack a silicate weathering thermostat so their climate is predicted to be less stable than that of planets with exposed continents. In other words, the continuously habitable zone for waterworlds is much narrower than for Earth-like planets. A planet's water is partitioned, however, between a surface reservoir, the ocean, and an interior reservoir, the mantle. Plate tectonics transports water between these reservoirs on geological timescales. Degassing of melt at mid-ocean ridgesmore » and serpentinization of oceanic crust depend negatively and positively on seafloor pressure, respectively, providing a stabilizing feedback on long-term ocean volume. Motivated by Earth's approximately steady-state deep water cycle, we develop a two-box model of the hydrosphere and derive steady-state solutions to the water partitioning on terrestrial planets. Critically, hydrostatic seafloor pressure is proportional to surface gravity, so super-Earths with a deep water cycle will tend to store more water in the mantle. We conclude that a tectonically active terrestrial planet of any mass can maintain exposed continents if its water mass fraction is less than ∼0.2%, dramatically increasing the odds that super-Earths are habitable. The greatest source of uncertainty in our study is Earth's current mantle water inventory: the greater its value, the more robust planets are to inundation. Lastly, we discuss how future missions can test our hypothesis by mapping the oceans and continents of massive terrestrial planets.« less

Solar system ice: Source of Earth's water

NASA Astrophysics Data System (ADS)

Beckwith, Andrew

2012-06-01

The contribution of carbanaceous chondrites in the water providing of the Earth has been discussed. It could be much more important than previously assumed. A comparison is made with the contribution by Comets.

Enhanced orbit determination filter: Inclusion of ground system errors as filter parameters

NASA Technical Reports Server (NTRS)

Masters, W. C.; Scheeres, D. J.; Thurman, S. W.

1994-01-01

The theoretical aspects of an orbit determination filter that incorporates ground-system error sources as model parameters for use in interplanetary navigation are presented in this article. This filter, which is derived from sequential filtering theory, allows a systematic treatment of errors in calibrations of transmission media, station locations, and earth orientation models associated with ground-based radio metric data, in addition to the modeling of the spacecraft dynamics. The discussion includes a mathematical description of the filter and an analytical comparison of its characteristics with more traditional filtering techniques used in this application. The analysis in this article shows that this filter has the potential to generate navigation products of substantially greater accuracy than more traditional filtering procedures.

FILTERED WATER RESERVOIR, LOOKING NORTHWEST. A CORNER OF THE NEW ...

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

FILTERED WATER RESERVOIR, LOOKING NORTHWEST. A CORNER OF THE NEW PUMPING STATION IS VISIBLE AT RIGHT. - Division Avenue Pumping Station & Filtration Plant, West 45th Street and Division Avenue, Cleveland, Cuyahoga County, OH

The Ins and Outs of Water in the Earth's Mantle

NASA Astrophysics Data System (ADS)

Hauri, E. H.; Gaetani, G. A.; Shaw, A. M.; Kelley, K. A.; Saal, A. E.

2005-12-01

Most of the hydrogen in the Earth's upper mantle is dissolved in nominally anhydrous minerals such as olivine, orthopyroxene, clinopyroxene and garnet as structural OH [e.g. 1 ]. Considering the significant influence of hydrogen on mantle properties such as solidus temperature, rheology, conductivity and seismic velocity, it is important to understand both the distribution of water among mantle phases and the mass transfer processes that influence water distribution in the Earth's mantle. Despite the important role of water in the mantle, experimental determinations of the equilibrium distribution of trace amounts of hydrogen among coexisting silicate phases remain extremely limited. Improved analytical techniques have recently paved the way for quantitative investigations of water partitioning and abundances in nominally anhydrous mantle minerals [e.g. 2]. Several studies of submarine glasses have revealed correlated increases in incompatible elements and water contents along segments of mid-ocean ridges approaching hotspots [e.g. 3,4]. A source-related increase in the water content of the mantle is typically postulated to explain such observations, but elevated hotspot H2O contents may also relate to pressure differences in partitioning of water, analogous to the case for rare-earth elements (e.g. the "garnet signature"). New experimental water partitioning data illuminate these differences. Hydrogen isotope ratios vary in submarine glasses from ocean ridges, back-arc basins and hotspots, and in hydrous phases from arcs and hotspots, suggesting significant hydrogen isotopic variability in the mantle, which may be related to the subduction of water. Water clearly enters the upper mantle at subduction zones, however the full water budget for any single subduction zone is highly uncertain [e.g. 5]. This uncertainty in the water budget at convergent margins indicates that we do not even know whether the present-day net flux of water is into or out of the Earth. This

The water-energy nexus: an earth science perspective

USGS Publications Warehouse

Healy, Richard W.; Alley, William M.; Engle, Mark A.; McMahon, Peter B.; Bales, Jerad D.

2015-01-01

Relevant earth science issues analyzed and discussed herein include freshwater availability; water use; ecosystems health; assessment of saline water resources; assessment of fossil-fuel, uranium, and geothermal resources; subsurface injection of wastewater and carbon dioxide and related induced seismicity; climate change and its effect on water availability and energy production; byproducts and waste streams of energy development; emerging energy-development technologies; and energy for water treatment and delivery.

Influence of PPCPs on the performance of intermittently operated slow sand filters for household water purification.

PubMed

Pompei, Caroline M E; Ciric, Lena; Canales, Melisa; Karu, Kersti; Vieira, Eny M; Campos, Luiza C

2017-03-01

Removal of pharmaceuticals and personal care products (PPCPs) from drinking water is usually enhanced by advanced oxidation which is not affordable in low income countries. Slow sand filtration has been found to be capable of removing anti-inflammatory compounds, and its low maintenance costs and easy operation make it an attractive technology for treating drinking water in many parts of the world. In addition, slow sand filters can be used at both large and household scales. The biofilm (i.e. schmutzdecke) developed on the top of the sand and within the upper layers of the sand is acknowledged to be responsible for the water purification. However, it is possible that the PPCPs may affect the schmutzdecke development and microbial community within the filters, and consequently the performance of the filter. This study investigated two household slow sand filters (for water purification) operated intermittently with and without contamination by six PPCPs. Eleven parameters were monitored in the affluent and effluent water, including bacterial species present and schmutzdecke biomass development. Results demonstrated that the household slow sand filter performance was not affected by the 2μgL -1 of PPCPs in the water. There was no significant difference between filters for total coliforms and E. coli removal, but there was considerable difference between sampling times. Biomass considerably increased with the number of filtrations in both filters and there was no significant difference between filter biomass. However, it was found that more bacterial species were present in the period with no contamination than during the contamination period. Bacillus anthracis and Exiguobacterium sp. showed to be resistant to the effects of the PPCPs. These suggest there are effects of PPCPs on bacterial species within the filter. However, the effect of the PPCPs on biomass was not conclusive in this study and needs to be further investigated. Copyright © 2016 Elsevier B.V. All

A Carbon Free Filter for Collection of Large Volume Samples of Cellular Biomass from Oligotrophic Waters

PubMed Central

Mailloux, Brian J.; Dochenetz, Audra; Bishop, Michael; Dong, Hailiang; Ziolkowski, Lori A.; Wommack, K. Eric; Sakowski, Eric G.; Onstott, Tullis C.; Slater, Greg F.

2018-01-01

Isotopic analysis of cellular biomass has greatly improved our understanding of carbon cycling in the environment. Compound specific radiocarbon analysis (CSRA) of cellular biomass is being increasingly applied in a number of fields. However, it is often difficult to collect sufficient cellular biomass for analysis from oligotrophic waters because easy-to-use filtering methods that are free of carbon contaminants do not exist. The goal of this work was to develop a new column based filter to autonomously collect high volume samples of biomass from oligotrophic waters for CSRA using material that can be baked at 450°C to remove potential organic contaminants. A series of filter materials were tested, including uncoated sand, ferrihydrite-coated sand, goethite-coated sand, aluminum-coated sand, uncoated glass wool, ferrihydrite-coated glass wool, and aluminum-coated glass wool, in the lab with 0.1 and 1.0 µm microspheres and E. coli. Results indicated that aluminum-coated glass wool was the most efficient filter and that the retention capacity of the filter far exceeded the biomass requirements for CSRA. Results from laboratory tests indicate that for oligotrophic waters with 1×105 cells ml−1, 117 L of water would need to be filtered to collect 100 µg of PLFA for bulk PLFA analysis and 2000 L for analysis of individual PLFAs. For field sampling, filtration tests on South African mine water indicated that after filtering 5955 liters, 450 µg of total PLFAs were present, ample biomass for radiocarbon analysis. In summary, we have developed a filter that is easy to use and deploy for collection of biomass for CSRA including total and individual PLFAs. PMID:22561839

Long-term evaluation of the performance of four point-of-use water filters.

PubMed

Pérez-Vidal, Andrea; Diaz-Gómez, Jaime; Castellanos-Rozo, Jose; Usaquen-Perilla, Olga Lucía

2016-07-01

Despite technological advances water supply quality and poor access to safe water remain a major problem in developing countries, especially in rural areas. Point-of-use (POU) water treatment has been shown to be a viable option to produce safe drinking water quality. The aim of this study was to evaluate, under laboratory conditions over 14 months, the performance of four household filtration systems: membrane filter (MF), one-candle ceramic filter (1CCF), two-candle ceramic filter (2CCF) and pot ceramic filter (PCF). The evaluation was made using spiked water having the required concentrations of turbidity, Escherichia coli and Total Dissolved Solids (TDS). The results show that all systems have high removal efficiencies for turbidity (98-99%), and E. coli 4-5 Log Reduction Value (LRV). The poorest efficiency was for TDS (9-18%). The MF and the CCF displayed no significant difference in efficiencies for these parameters. The PCF had less significant differences for turbidity removal than the other systems. The average filtration rate for all systems decreased during the operation time. The CPF showed the major potential to be used in rural communities mainly for its low operational level and maintenance requirements as well as its local craftsmanship. It was observed that the efficiency of the systems is highly sensitive to cleaning and maintenance activities and therefore, the system sustainability will depend considerably on the training and education of the potential users. Copyright © 2016 Elsevier Ltd. All rights reserved.

WATER FORMATION IN THE UPPER ATMOSPHERE OF THE EARLY EARTH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fleury, Benjamin; Carrasco, Nathalie; Marcq, Emmanuel

2015-07-10

The water concentration and distribution in the early Earth's atmosphere are important parameters that contribute to the chemistry and the radiative budget of the atmosphere. If the atmosphere above the troposphere is generally considered as dry, photochemistry is known to be responsible for the production of numerous minor species. Here we used an experimental setup to study the production of water in conditions simulating the chemistry above the troposphere of the early Earth with an atmospheric composition based on three major molecules: N{sub 2}, CO{sub 2}, and H{sub 2}. The formation of gaseous products was monitored using infrared spectroscopy. Watermore » was found as the major product, with approximately 10% of the gas products detected. This important water formation is discussed in the context of the early Earth.« less

Microbial pesticide removal in rapid sand filters for drinking water treatment--potential and kinetics.

PubMed

Hedegaard, Mathilde J; Albrechtsen, Hans-Jørgen

2014-01-01

Filter sand samples, taken from aerobic rapid sand filters used for treating groundwater at three Danish waterworks, were investigated for their pesticide removal potential and to assess the kinetics of the removal process. Microcosms were set up with filter sand, treated water, and the pesticides or metabolites mecoprop (MCPP), bentazone, glyphosate and p-nitrophenol were applied in initial concentrations of 0.03-2.4 μg/L. In all the investigated waterworks the concentration of pesticides in the water decreased - MCPP decreased to 42-85%, bentazone to 15-35%, glyphosate to 7-14% and p-nitrophenol 1-3% - from the initial concentration over a period of 6-13 days. Mineralisation of three out of four investigated pesticides was observed at Sjælsø waterworks Plant II - up to 43% of the initial glyphosate was mineralised within six days. At Sjælsø waterworks Plant II the removal kinetics of bentazone revealed that less than 30 min was needed to remove 50% of the bentazone at all the tested initial concentrations (0.1-2.4 μg/L). Increased oxygen availability led to greater and faster removal of bentazone in the microcosms. After 1 h, bentazone removal (an initial bentazone concentration of 0.1 μg/L) increased from 0.21%/g filter sand to 0.75%/g filter sand, when oxygen availability was increased from 0.28 mg O2/g filter sand to 1.09 mg O2/g filter sand. Bentazone was initially cleaved in the removal process. A metabolite, which contained the carbonyl group, was removed rapidly from the water phase and slowly mineralised after 24 h, while a metabolite which contained the benzene-ring was still present in the water phase. However, the microbial removal of this metabolite was initiated over seven days. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

USDA-ARS?s Scientific Manuscript database

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

2. EXTERIOR VIEW TO THE NORTH OF WATER FILTERING EQUIPMENT ...

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

2. EXTERIOR VIEW TO THE NORTH OF WATER FILTERING EQUIPMENT AND BROCK HOUSES ALONG THE EAST SIDE OF THE COMPOUND. - Nevada Test Site, Pluto Facility, Area 26, Wahmonie Flats, Cane Spring Road, Mercury, Nye County, NV

Comparison and testing of extended Kalman filters for attitude estimation of the Earth radiation budget satellite

NASA Technical Reports Server (NTRS)

Deutschmann, Julie; Bar-Itzhack, Itzhack Y.; Rokni, Mohammad

1990-01-01

The testing and comparison of two Extended Kalman Filters (EKFs) developed for the Earth Radiation Budget Satellite (ERBS) is described. One EKF updates the attitude quaternion using a four component additive error quaternion. This technique is compared to that of a second EKF, which uses a multiplicative error quaternion. A brief development of the multiplicative algorithm is included. The mathematical development of the additive EKF was presented in the 1989 Flight Mechanics/Estimation Theory Symposium along with some preliminary testing results using real spacecraft data. A summary of the additive EKF algorithm is included. The convergence properties, singularity problems, and normalization techniques of the two filters are addressed. Both filters are also compared to those from the ERBS operational ground support software, which uses a batch differential correction algorithm to estimate attitude and gyro biases. Sensitivity studies are performed on the estimation of sensor calibration states. The potential application of the EKF for real time and non-real time ground attitude determination and sensor calibration for future missions such as the Gamma Ray Observatory (GRO) and the Small Explorer Mission (SMEX) is also presented.

Potential of silver nanoparticle-coated polyurethane foam as an antibacterial water filter.

PubMed

Jain, Prashant; Pradeep, T

2005-04-05

Silver nanoparticles can be coated on common polyurethane (PU) foams by overnight exposure of the foams to nanoparticle solutions. Repeated washing and air-drying yields uniformly coated PU foam, which can be used as a drinking water filter where bacterial contamination of the surface water is a health risk. Nanoparticles are stable on the foam and are not washed away by water. Morphology of the foam was retained after coating. The nanoparticle binding is due to its interaction with the nitrogen atom of the PU. Online tests were conducted with a prototypical water filter. At a flow rate of 0.5 L/min, in which contact time was of the order of a second, the output count of Escherichia coli was nil when the input water had a bacterial load of 10(5) colony-forming units (CFU) per mL. Combined with the low cost and effectiveness in its applications, the technology may have large implications to developing countries. Copyright (c) 2005 Wiley Periodicals, Inc.

Treatment of table olive washing water using trickling filters, constructed wetlands and electrooxidation.

PubMed

Tatoulis, Triantafyllos; Stefanakis, Alexandros; Frontistis, Zacharias; Akratos, Christos S; Tekerlekopoulou, Athanasia G; Mantzavinos, Dionissios; Vayenas, Dimitrios V

2017-01-01

The production of table olives is a significant economic activity in Mediterranean countries. Table olive processing generates large volumes of rinsing water that are characterized by high organic matter and phenol contents. Due to these characteristics, a combination of more than one technology is imperative to ensure efficient treatment with low operational cost. Previously, biological filters were combined with electrooxidation to treat table olive washing water. Although this combination was successful in reducing pollutant loads, its cost could be further reduced. Constructed wetlands could be an eligible treatment method for integrated table olive washing water treatment as they have proved tolerant to high organic matter and phenol loads. Two pilot-scale horizontal subsurface constructed wetlands, one planted and one unplanted, were combined with a biological filter and electrooxidation over a boron-doped diamond anode to treat table olive washing water. In the biological filter inlet, chemical oxygen demand (COD) concentrations ranged from 5500 to 15,000 mg/L, while mean COD influent concentration in the constructed wetlands was 2800 mg/L. The wetlands proved to be an efficient intermediate treatment stage, since COD removal levels for the planted unit reached 99 % (mean 70 %), while the unplanted unit presented removal rates of around 65 %. Moreover, the concentration of phenols in the effluent was typically below 100 mg/L. The integrated trickling filter-constructed wetland-electrooxidation treatment system examined here could mineralize and decolorize table olive washing water and fully remove its phenolic content.

Properties of an Earth-like planet orbiting a Sun-like star: Earth observed by the EPOXI mission.

PubMed

Livengood, Timothy A; Deming, L Drake; A'hearn, Michael F; Charbonneau, David; Hewagama, Tilak; Lisse, Carey M; McFadden, Lucy A; Meadows, Victoria S; Robinson, Tyler D; Seager, Sara; Wellnitz, Dennis D

2011-11-01

NASA's EPOXI mission observed the disc-integrated Earth and Moon to test techniques for reconnoitering extrasolar terrestrial planets, using the Deep Impact flyby spacecraft to observe Earth at the beginning and end of Northern Hemisphere spring, 2008, from a range of ∼1/6 to 1/3 AU. These observations furnish high-precision and high-cadence empirical photometry and spectroscopy of Earth, suitable as "ground truth" for numerically simulating realistic observational scenarios for an Earth-like exoplanet with finite signal-to-noise ratio. Earth was observed at near-equatorial sub-spacecraft latitude on 18-19 March, 28-29 May, and 4-5 June (UT), in the range of 372-4540 nm wavelength with low visible resolving power (λ/Δλ=5-13) and moderate IR resolving power (λ/Δλ=215-730). Spectrophotometry in seven filters yields light curves at ∼372-948 nm filter-averaged wavelength, modulated by Earth's rotation with peak-to-peak amplitude of ≤20%. The spatially resolved Sun glint is a minor contributor to disc-integrated reflectance. Spectroscopy at 1100-4540 nm reveals gaseous water and carbon dioxide, with minor features of molecular oxygen, methane, and nitrous oxide. One-day changes in global cloud cover resulted in differences between the light curve beginning and end of ≤5%. The light curve of a lunar transit of Earth on 29 May is color-dependent due to the Moon's red spectrum partially occulting Earth's relatively blue spectrum. The "vegetation red edge" spectral contrast observed between two long-wavelength visible/near-IR bands is ambiguous, not clearly distinguishing between the verdant Earth diluted by cloud cover versus the desolate mineral regolith of the Moon. Spectrophotometry in at least one other comparison band at short wavelength is required to distinguish between Earth-like and Moon-like surfaces in reconnaissance observations. However, measurements at 850 nm alone, the high-reflectance side of the red edge, could be sufficient to

Pollution patterns and underlying relationships of benzophenone-type UV-filters in wastewater treatment plants and their receiving surface water.

PubMed

Wu, Ming-Hong; Li, Jian; Xu, Gang; Ma, Luo-Dan; Li, Jia-Jun; Li, Jin-Song; Tang, Liang

2018-05-15

The environmental behaviors of emerging pollutants, benzophenone-type UV filters (BP-UV filters) and their derivatives were investigated in four wastewater treatment plants (WWTPs), and their receiving surface waters in Shanghai. The concentration level of selected BP-UV filters in the WWTPs was detected from ngL -1 to μgL -1 . BP (621-951ngL -1 ) and BP-3 (841-1.32 × 10 3 ngL -1 ) were the most abundant and highest detection frequency individuals among the target BP-UV filters in influents, whereas BP (198-400ngL -1 ), BP-4 (93.3-288ngL -1 ) and BP-3 (146-258ngL -1 ) were predominant in effluents. BP-UV filters cannot be completely removed and the total removal efficiency varied widely (-456% to 100%) during the treatment process. It can be inferred that the usage of BP and BP-3 are higher than other BP-UV filters in the study area. The lowest and highest levels were BP-2 (ND-7.66ngL -1 ) and BP-3 (68.5-5.01 × 10 3 ng L -1 ) in the receiving surface water, respectively. Interestingly, the seasonal variation of BP-3 is larger than those of other BP-UV filters in surface water from Shanghai. There is no obvious pollution pattern of BP-UV filters in the surface water from the cosmetic factory area. The correlation analysis of BP-UV filters between WWTPs effluents and nearby downstream water samples suggested that BP-UV filters emitted from some WWTPs might be the main source of receiving surface water. Preliminary risk assessment indicated that the levels of BP-UV filters detected by the effluent posed medium to high risk to fish as well as other aquatic organisms. Copyright © 2018 Elsevier Inc. All rights reserved.

Design for sustainable development--household drinking water filter for arsenic and pathogen treatment in Nepal.

PubMed

Ngai, Tommy K K; Shrestha, Roshan R; Dangol, Bipin; Maharjan, Makhan; Murcott, Susan E

2007-10-01

In the last 20 years, the widespread adoption of shallow tubewells in Nepal Terai region enabled substantial improvement in access to water, but recent national water quality testing showed that 3% of these sources contain arsenic above the Nepali interim guideline of 50 microg/L, and up to 60% contain unsafe microbial contamination. To combat this crisis, MIT, ENPHO and CAWST together researched, developed and implemented a household water treatment technology by applying an iterative, learning development framework. A pilot study comparing 3 technologies against technical, social, and economic criteria showed that the Kanchan Arsenic Filter (KAF) is the most promising technology for Nepal. A two-year technical and social evaluation of over 1000 KAFs deployed in rural villages of Nepal determined that the KAF typically removes 85-90% arsenic, 90-95% iron, 80-95% turbidity, and 85-99% total coliforms. Then 83% of the households continued to use the filter after 1 year, mainly motivated by the clean appearance, improved taste, and reduced odour of the filtered water, as compared to the original water source. Although over 5,000 filters have been implemented in Nepal by January 2007, further research rooted in sustainable development is necessary to understand the technology diffusion and scale-up process, in order to expand access to safe water in the country and beyond.

Explaining low rates of sustained use of siphon water filter: evidence from follow-up of a randomised controlled trial in Bangladesh.

PubMed

Najnin, Nusrat; Arman, Shaila; Abedin, Jaynal; Unicomb, Leanne; Levine, David I; Mahmud, Minhaj; Leder, Karin; Yeasmin, Farzana; Luoto, Jill E; Albert, Jeff; Luby, Stephen P

2015-04-01

To assess sustained siphon filter usage among a low-income population in Bangladesh and study relevant motivators and barriers. After a randomised control trial in Bangladesh during 2009, 191 households received a siphon water filter along with educational messages. Researchers revisited households after 3 and 6 months to assess filter usage and determine relevant motivators and barriers. Regular users were defined as those who reported using the filter most of the time and were observed to be using the filter at follow-up visits. Integrated behavioural model for water, sanitation and hygiene (IBM-WASH) was used to explain factors associated with regular filter use. Regular filter usage was 28% at the 3-month follow-up and 21% at the 6-month follow-up. Regular filter users had better quality water at the 6-month, but not at the 3-month visit. Positive predictors of regular filter usage explained through IBM-WASH at both times were willingness to pay >US$1 for filters, and positive attitude towards filter use (technology dimension at individual level); reporting boiling drinking water at baseline (psychosocial dimension at habitual level); and Bengali ethnicity (contextual dimension at individual level). Frequently reported barriers to regular filter use were as follows: considering filter use an additional task, filter breakage and time required for water filtering (technology dimension at individual level). The technological, psychosocial and contextual dimensions of IBM-WASH contributed to understanding the factors related to sustained use of siphon filter. Given the low regular usage rate and the hardware-related problems reported, the contribution of siphon filters to improving water quality in low-income urban communities in Bangladesh is likely to be minimal. © 2014 John Wiley & Sons Ltd.

27 CFR 24.243 - Filtering aids.

Code of Federal Regulations, 2010 CFR

2010-04-01

... fibers, pulps, earths, or similar materials, may be used as filtering aids in the cellar treatment and finishing of wine. Agar-agar, carrageenan, cellulose, and diatomaceous earth are commonly employed inert...

27 CFR 24.243 - Filtering aids.

Code of Federal Regulations, 2011 CFR

2011-04-01

... fibers, pulps, earths, or similar materials, may be used as filtering aids in the cellar treatment and finishing of wine. Agar-agar, carrageenan, cellulose, and diatomaceous earth are commonly employed inert...

Earth Observations for Global Water Security

NASA Technical Reports Server (NTRS)

Lawford, Richard; Strauch, Adrian; Toll, David; Fekete, Balazs; Cripe, Douglas

2013-01-01

The combined effects of population growth, increasing demands for water to support agriculture, energy security, and industrial expansion, and the challenges of climate change give rise to an urgent need to carefully monitor and assess trends and variations in water resources. Doing so will ensure that sustainable access to adequate quantities of safe and useable water will serve as a foundation for water security. Both satellite and in situ observations combined with data assimilation and models are needed for effective, integrated monitoring of the water cycle's trends and variability in terms of both quantity and quality. On the basis of a review of existing observational systems, we argue that a new integrated monitoring capability for water security purposes is urgently needed. Furthermore, the components for this capability exist and could be integrated through the cooperation of national observational programmes. The Group on Earth Observations should play a central role in the design, implementation, management and analysis of this system and its products.

Earth Glint Observations Conducted During the Deep Impact Spacecraft Flyby

NASA Technical Reports Server (NTRS)

Barry, R. K.; Deming, L. D.; Robinson, T.; Hewagama, T.

2010-01-01

We describe observations of Earth conducted using the High Resolution Instrument (HRI) - a 0.3 m f/35 telescope - on the Deep Impact (DI) spacecraft during its recent flybys. Earth was observed on five occasions: 2008-Mar-18 18:18 UT, 2008-May-28 20:05 UT, 2008-Jun-4 16:57 UT, 2009-Mar-27 16:19 and 2009-Oct-4 09:37 UT. Each set of observations was conducted over a full 24-hour rotation of Earth and a total of thirteen NIR spectra were taken on two-hour intervals during each observing period. Photometry in the 450, SSO, 650 and 8S0 nm filters was taken every fifteen minutes and every hour for the 350, 750 and 950 nm filters. The spacecraft was located over the equator for the three sets of observations in 2008, while the 2009- Mar and 2009-Oct were taken over the north and south Polar Regions, respectively. Observations of calibrator stars Canopus and Achernar were conducted on multiple occasions through all filters. The observations detected a strong specular glint not necessarily associated with a body of water. We describe spectroscopic characterization of the glint and evidence for the possibility of detection of reflection from high cirrus clouds. We describe implications for observations of extrasolar planets.

[Denitrification water treatment with zeolite composite filter by intermittent operation].

PubMed

Qing, Cheng-Song; Bao, Tao; Chen, Tian-Hu; Chen, Dong; Xie, Jing-Jing

2012-12-01

The zeolite composite filters (ZCF) with the size of4-8 mm were prepared using raw zeolite (0.15-0.18 mm) as the main material and the cement as binder. After a combination of material characterizations, such as the void fraction, apparent density, compression strength and surface area, the optimal prepared conditions of composite filters were obtained as follow: weight ratio of m (zeolite): m (cement) = 7 : 3, curing for 15 d under the moisture condition and ambient temperature. Through upflow low-concentration ammonia nitrogen wastewater, ZCF filled in the experimental column was hung with the biological membrane. Thus, intermittent dynamic experiments were conducted, the intermittent operation cycle included adsorption, biological regeneration and drip washing. Until concentration of ammonia nitrogen was more than 2 mg x L(-1) of effluent standards, water in experiment column was firstly emptied, and then blast biological regeneration was conducted. After the filters were bathed with water, the zeolite adsorption-biological regeneration cycle was performed repeatedly. The experimental results show that under conditions of 24 h blast and 5 d of continuous operation period, ammonia nitrogen removal rate is up to 87.6% on average, total nitrogen removal rate reaches 51.2% on average.

Water Processing Assembly Particulate Filter Remove and Replace (R&R)

NASA Image and Video Library

2013-07-12

ISS036-E-018008 (12 July 2013) --- European Space Agency astronaut Luca Parmitano, Expedition 36 flight engineer, removes and replaces the particulate filter for the Water Pump Assembly 2 (WPA2) in Tranquility (also called Node 3) on the International Space Station.

Water Processing Assembly Particulate Filter Remove and Replace (R&R)

NASA Image and Video Library

2013-07-12

ISS036-E-018007 (12 July 2013) --- European Space Agency astronaut Luca Parmitano, Expedition 36 flight engineer, removes and replaces the particulate filter for the Water Pump Assembly 2 (WPA2) in Tranquility (also called Node 3) on the International Space Station.

[Water-filtered infrared-A (wIRA) promotes wound healing].

PubMed

Winkel, R; Hoffmann, G; Hoffmann, R

2014-11-01

Water-filtered infrared-A (wIRA) is a special form of heat radiation with high tissue penetration and low thermal load to the skin surface which promotes the healing of acute and chronic wounds both by thermal and thermic as well as by non-thermal and non-thermic effects. Water-filtered infrared-A increases tissue temperature (+ 2.7 °C at a tissue depth of 2 cm), tissue oxygen partial pressure (+ 32 % at a tissue depth of 2 cm) and tissue perfusion. These three factors are decisive for a sufficient supply of tissue with energy and oxygen and consequently also for wound healing and infection defense. Water-filtered infrared-A promotes normal as well as disturbed wound healing by diminishing inflammation and exudation, by promotion of infection defense and regeneration, and by alleviation of pain. These effects have been proven in a total of seven prospective studies (of these six randomized controlled studies) with most of the effects having an evidence level of Ia or Ib. The additional cases of complicated courses of wound healing presented in this article illustrate the proven effects of wIRA. Not only in the 6 presented cases wIRA turned the complicated courses of wound healing for the better and facilitated the healing of the wounds after varying total times of irradiation (in the 6 cases 51-550 h) and after variable times of wound care and mostly after transplantation of split skin grafts. In complicated courses of wound healing wIRA does not replace consultation and, when indicated, treatment by an experienced plastic surgeon and by a surgeon specialized in septic surgery. With these limitations wIRA can be recommended as a valuable complement for the treatment of acute as well as of chronic wounds.

Portable Nanomesh Creates Safer Drinking Water

NASA Technical Reports Server (NTRS)

2008-01-01

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

MANUFACTURING FACILITY FOR ACTIVATED CARBON AND CERAMIC WATER FILTERS AT THE SONGHAI CENTER, BENIN

EPA Science Inventory

Ceramic filters will be manufactured at the Songhai Center in Porto-Novo, Benin for cost-effective drinking water treatment. The efficiency of the ceramic filters will be improved by adding activated carbon cartridges to remove organic and inorganic impurities. The activate...

R2 Water Quality Portal Monitoring Stations

EPA Pesticide Factsheets

The Water Quality Data Portal (WQP) provides an easy way to access data stored in various large water quality databases. The WQP provides various input parameters on the form including location, site, sampling, and date parameters to filter and customize the returned results. The The Water Quality Portal (WQP) is a cooperative service sponsored by the United States Geological Survey (USGS), the Environmental Protection Agency (EPA) and the National Water Quality Monitoring Council (NWQMC) that integrates publicly available water quality data from the USGS National Water Information System (NWIS) the EPA STOrage and RETrieval (STORET) Data Warehouse, and the USDA ARS Sustaining The Earth??s Watersheds - Agricultural Research Database System (STEWARDS).

Water washable stainless steel HEPA filter

DOEpatents

Phillips, Terrance D.

2001-01-01

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

Dataset on the cost estimation for spent filter backwash water (SFBW) treatment.

PubMed

Ebrahimi, Afshin; Mahdavi, Mokhtar; Pirsaheb, Meghdad; Alimohammadi, Fariborz; Mahvi, Amir Hossein

2017-12-01

The dataset presented in this article are related to the research article entitled "Hybrid coagulation-UF processes for spent filter backwash water treatment: a comparison studies for PAFCl and FeCl 3 as a pre-treatment" (Ebrahimi et al., 2017) [1]. This article reports the cost estimation for treating produced spent filter backwash water (SFBW) during water treatment in Isfahan- Iran by various methods including primary sedimentation, coagulation & flocculation, second clarification, ultra filtration (UF) and recirculation of settled SFBW to water treatment plant (WTP) entrance. Coagulation conducted by PAFCl and FeCl 3 as pre polymerized and traditional coagulants. Cost estimation showed that contrary to expectations, the recirculation of settled SFBW to WTP entrance is more expensive than other method and it costs about $ 37,814,817.6. Versus the cheapest option related to separate primary sedimentation, coagulation & flocculation in WTP. This option cost about $ 4,757,200 and $ 950,213 when FeCl3 and PAFCl used as coagulant, respectively.

Removal of virus to protozoan sized particles in point-of-use ceramic water filters.

PubMed

Bielefeldt, Angela R; Kowalski, Kate; Schilling, Cherylynn; Schreier, Simon; Kohler, Amanda; Scott Summers, R

2010-03-01

The particle removal performance of point-of-use ceramic water filters (CWFs) was characterized in the size range of 0.02-100 microm using carboxylate-coated polystyrene fluorescent microspheres, natural particles and clay. Particles were spiked into dechlorinated tap water, and three successive water batches treated in each of six different CWFs. Particle removal generally increased with increasing size. The removal of virus-sized 0.02 and 0.1 microm spheres were highly variable between the six filters, ranging from 63 to 99.6%. For the 0.5 microm spheres removal was less variable and in the range of 95.1-99.6%, while for the 1, 2, 4.5, and 10 microm spheres removal was >99.6%. Recoating four of the CWFs with colloidal silver solution improved removal of the 0.02 microm spheres, but had no significant effects on the other particle sizes. Log removals of 1.8-3.2 were found for natural turbidity and spiked kaolin clay particles; however, particles as large as 95 microm were detected in filtered water. Copyright 2009 Elsevier Ltd. All rights reserved.

Nanofiber Filters Eliminate Contaminants

NASA Technical Reports Server (NTRS)

2009-01-01

With support from Phase I and II SBIR funding from Johnson Space Center, Argonide Corporation of Sanford, Florida tested and developed its proprietary nanofiber water filter media. Capable of removing more than 99.99 percent of dangerous particles like bacteria, viruses, and parasites, the media was incorporated into the company's commercial NanoCeram water filter, an inductee into the Space Foundation's Space Technology Hall of Fame. In addition to its drinking water filters, Argonide now produces large-scale nanofiber filters used as part of the reverse osmosis process for industrial water purification.

Searching for Water Earths in the Near-infrared

NASA Astrophysics Data System (ADS)

Zugger, M. E.; Kasting, J. F.; Williams, D. M.; Kane, T. J.; Philbrick, C. R.

2011-09-01

Over 500 extrasolar planets (exoplanets) have now been discovered, but only a handful are small enough that they might be rocky terrestrial planets like Venus, Earth, and Mars. Recently, it has been proposed that observations of variability in scattered light (both polarized and total flux) from such terrestrial-sized exoplanets could be used to determine if they possess large surface oceans, an important indicator of potential habitability. Observing such oceans at visible wavelengths would be difficult, however, in part because of obscuration by atmospheric scattering. Here, we investigate whether observations performed in the near-infrared (NIR), where Rayleigh scattering is reduced, could improve the detectability of exoplanet oceans. We model two wavebands of the NIR which are "window regions" for an Earth-like atmosphere: 1.55-1.75 μm and 2.1-2.3 μm. Our model confirms that obscuration in these bands from Rayleigh scattering is very low, but aerosols are generally the limiting factor throughout the wavelength range for Earth-like atmospheres. As a result, observations at NIR wavelengths are significantly better at detecting oceans than those at visible wavelengths only when aerosols are very thin by Earth standards. Clouds further dilute the ocean reflection signature. Hence, other techniques, e.g., time-resolved color photometry, may be more effective in the search for liquid water on exoplanet surfaces. Observing an exo-Earth at NIR wavelengths does open the possibility of detecting water vapor or other absorbers in the atmosphere, by comparing scattered light in window regions to that in absorption bands.

Principles and working mechanisms of water-filtered infrared-A (wIRA) in relation to wound healing

PubMed Central

Hoffmann, Gerd

2007-01-01

The experience of the pleasant heat of the sun in moderate climatic zones arises from the filtering of the heat radiation of the sun by water vapor in the atmosphere of the earth. The filter effect of water decreases those parts of infrared radiation (most parts of infrared-B and -C and the absorption bands of water within infrared-A), which would cause – by reacting with water molecules in the skin – only an undesired thermal load to the surface of the skin. Technically water-filtered infrared-A (wIRA) is produced in special radiators, whose full spectrum of radiation of a halogen bulb is passed through a cuvette, containing water, which absorbs or decreases the described undesired wavelengths of the infrared radiation. Within infrared the remaining wIRA (within 780-1400 nm) mainly consists of radiation with good penetration properties into tissue and therefore allows – compared to unfiltered heat radiation – a multiple energy transfer into tissue without irritating the skin, similar to the sun’s heat radiation in moderate climatic zones. Typical wIRA radiators emit no ultraviolet (UV) radiation and nearly no infrared-B and -C radiation and the amount of infrared-A radiation in relation to the amount of visible light (380-780 nm) is emphasized. Water-filtered infrared-A as a special form of heat radiation with a high tissue penetration and with a low thermal load to the skin surface acts both by thermal (related to heat energy transfer) and thermic (temperature depending, with a relevant change of temperature) as well as by non-thermal (without a relevant transfer of heat energy) and non-thermic (not depending on temperature, without a relevant change of temperature) effects. wIRA produces a therapeutically usable field of heat in the tissue and increases tissue temperature, tissue oxygen partial pressure, and tissue perfusion. These three factors are vital for a sufficient tissue supply with energy and oxygen. As wound healing and infection defense (e

Use of remotely reporting electronic sensors for assessing use of water filters and cookstoves in Rwanda.

PubMed

Thomas, Evan A; Barstow, Christina K; Rosa, Ghislaine; Majorin, Fiona; Clasen, Thomas

2013-01-01

Remotely reporting electronic sensors offer the potential to reduce bias in monitoring use of environmental health interventions. In the context of a five-month randomized controlled trial of household water filters and improved cookstoves in rural Rwanda, we collected data from intervention households on product compliance using (i) monthly surveys and direct observations by community health workers and environmental health officers, and (ii) sensor-equipped filters and cookstoves deployed for about two weeks in each household. The adoption rate interpreted by the sensors varied from the household reporting: 90.5% of households reported primarily using the intervention stove, while the sensors interpreted 73.2% use, and 96.5% of households reported using the intervention filter regularly, while the sensors interpreted no more than 90.2%. The sensor-collected data estimated use to be lower than conventionally collected data both for water filters (approximately 36% less water volume per day) and cookstoves (approximately 40% fewer uses per week). An evaluation of intrahousehold consistency in use suggests that households are not using their filters or stoves on an exclusive basis, and may be both drinking untreated water at times and using other stoves ("stove-stacking"). These results provide additional evidence that surveys and direct observation may exaggerate compliance with household-based environmental interventions.

Removal of organic micropollutants from drinking water by a novel electro-Fenton filter: Pilot-scale studies.

PubMed

Plakas, Konstantinos V; Sklari, Stella D; Yiankakis, Dimitrios A; Sideropoulos, Georgios Th; Zaspalis, Vassilis T; Karabelas, Anastasios J

2016-03-15

To assess the performance of a novel 'filter'-type electro-Fenton (EF) device, results are reported from pilot-scale studies of continuous water treatment, to degrade diclofenac (DCF), a typical organic micro-pollutant, with no addition of oxidants. The novel 'filter' consisted of three pairs of anode/cathode electrodes made of carbon felt, with cathodes impregnated with iron nanoparticles (γ-Fe2O3/F3O4 oxides). The best 'filter' performance was obtained at applied potential of 2 V and low water superficial velocities (∼0.09 cm/s), i.e., the mineralization current efficiency (MCE) was >20%, during continuous steady state treatment of tap water with low DCF concentrations (16 μg/L). The EF 'filter' exhibited satisfactory stability regarding both electrode integrity (no iron leaching) and removal efficiency, even after multiple filtration/oxidation treatment cycles, achieving (under steady conditions) DCF and TOC removal 85% and 36%, respectively. This performance is considered satisfactory because the EF process took place under rather unfavorable conditions, such as neutral pH, low dissolved O2 concentration, low electrical conductivity, and presence of natural organic matter and inorganic ions in tap water. Ongoing R&D is aimed at 'filter' development and optimization for practical applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Method for Salmonella concentration from water at pH 3.5, using micro-fiber glass filters.

PubMed Central

Block, J C; Rolland, D

1979-01-01

A method is described for the concentration of Salmonella from water. As is done with enterovirus, Salmonella bacteria were concentrated from water in two steps: by pH 3.5 adsorption on and pH 9.5 elution from 8-micron porosity micro-fiber glass filter tubes. This method worked in less than 30 min, and Salmonella typhimurium was inactivated only slightly in spite of rapid pH variations (pH 3.5 to 9.5). It was demonstrated that the retention by the filters stems from two phenomena: a low retention in the micro-fiber glass labyrinth for small filtered volumes, and a high retention by adsorption at pH 3.5 for any filtered volume (experiments done with 15- and 80-liter samples). Addition in tap water of trivalent ions like Al3+ did not increase Salmonella adsorption. In most of the trials, Salmonella recovery varied from 42 to 93%. Preliminary field investigations indicate that enterovirus and Salmonella may both be concentrated from the same water sample by this procedure. PMID:39501

Organic/inorganic hybrid filters based on dendritic and cyclodextrin "nanosponges" for the removal of organic pollutants from water.

PubMed

Arkas, Michael; Allabashi, Roza; Tsiourvas, Dimitris; Mattausch, Eva-Maria; Perfler, Reinhard

2006-04-15

Long-alkyl chain functionalized poly(propylene imine) dendrimer, poly(ethylene imine) hyperbranched polymer, and beta-cyclodextrin derivatives, which are completely insoluble in water, have the property of encapsulating organic pollutants from water. Ceramic porous filters can be impregnated with these compounds resulting in hybrid organic/ inorganic filter modules. These hybrid filter modules were tested for the effective purification of water, by continuous filtration experiments, employing a variety of water pollutants. It has been established that polycyclic aromatic hydrocarbons (PAHs) can be removed very efficiently (more than 95%), and final concentrations of several ppb (microg/ L) are easily obtained. Representatives of the pollutant group of trihalogen methanes (THMs), monoaromatic hydrocarbons (BTX), and pesticides (simazine) can also be removed (>80%), although the filters are saturated considerably faster in these cases.

Maps showing water-level declines, land subsidence, and earth fissures in south-central Arizona

USGS Publications Warehouse

Laney, R.L.; Raymond, R.H.; Winikka, C.C.

1978-01-01

From 1915 to 1975, more than 109 million acre-feet of ground water was withdrawn from about 4,500 square miles in Pinal and Maricopa Counties in south-central Arizona. The volume of water withdrawn greatly exceeds the volume of natural recharge, and water levels have been declining since 1923. As a result of the water-level declines, the land surface has subsided, the alluvial deposits have been subjected to stress, and earth fissures have developed. Land subsidence and earth fissures have damaged public and private properties. Subsidence and fissures will continue to occur as long as ground water is being mined and water levels continue to decline. As urban development expands, land subsidence and earth fissures will have an increasing socioeconomic impact. Information on maps includes change in water levels, measurements of land subsidence, and location of earth fissures. A section showing land subsidence between Casa Grande and the Picacho Peak Interchange also is included. Scale 1:250,000. (Woodard-USGS)

Rare Earth Element Geochemistry for Produced Waters, WY

DOE Data Explorer

Quillinan, Scott; Nye, Charles; McLing, Travis; Neupane, Hari

2016-06-30

These data represent major, minor, trace, isotopes, and rare earth element concentrations in geologic formations and water associated with oil and gas production. *Note - Link below contains updated version of spreadsheet (6/14/2017)

The effect of using different 0.45 μm filter membranes on 'dissolved' element concentrations in natural waters

USGS Publications Warehouse

Hall, G.E.M.; Bonham-Carter, G. F.; Horowitz, A.J.; Lum, K.; Lemieux, C.; Quemerais, B.; Garbarino, J.R.

1996-01-01

The effect of 4 different 0.45 ??m pore size filter membrane systems on the 'dissolved' concentration of 28 elements in 5 natural water samples of varying matrix is reported. In 3 of the 5 waters, consistently higher concentrations of most elements (minor and trace) are obtained using Nucleopore 47 mm filter and the cellulose acetate/nitrate 47 mm filter than those measured using the 142 mm cellulose nitrate MFS filter or the Gelman capsule 47 mm filter. These distinct and coherent patterns in elemental behaviour disappear for the other 2 samples, an organic-rich peat water of high suspended load and a mineralised sample high in Si and Ca. Thus the nature and degree of filtration artifacts is matrix-dependent. These trends are evident in both data sets produced by 2 independent laboratories using different instrumentation, techniques and calibrating procedures. The average relative standard deviation in elemental concentration across the 4 filter types is in the range 9-21%. The presence of such filtration artifacts must be considered in projects where, for example, seasonal variability of water composition is under examination, data from various sources are being merged or hydrogeochemical surveys are being conducted.

Synthetic ultraviolet light filtering chemical contamination of coastal waters of Virgin Islands National Park, St. John, U.S. Virgin Islands

USGS Publications Warehouse

Bargar, Timothy A.; Alvarez, David; Garrison, Virginia H.

2015-01-01

Contamination of surface waters by synthetic ultraviolet light (UV) filtering chemicals is a concern for the Virgin Islands National Park (VINP). Discrete water samples were collected from VINP bays to determine UV filter chemical presence in the coastal waters. Spatial distribution and the potential for partitioning between subsurface waters and the sea surface microlayer (SML) were also examined. The UV filter chemicals 4-methylbenzylidene camphor, benzophenone-3, octinoxate, homosalate, and octocrylene were detected at concentrations up to 6073 ng/L (benzophenone-3). Concentrations for benzophenone-3 and homosalate declined exponentially (r2 = 0.86 to 0.98) with distance from the beach. Limited data indicate that some UV filter chemicals may partition to the SML relative to the subsurface waters. Contamination of VINP coastal waters by UV filter chemicals may be a significant issue, but an improved understanding of the temporal and spatial variability of their concentrations would be necessary to better understand the risk they present.

The effect of the earth's rotation on ground water motion.

PubMed

Loáiciga, Hugo A

2007-01-01

The average pore velocity of ground water according to Darcy's law is a function of the fluid pressure gradient and the gravitational force (per unit volume of ground water) and of aquifer properties. There is also an acceleration exerted on ground water that arises from the Earth's rotation. The magnitude and direction of this rotation-induced force are determined in exact mathematical form in this article. It is calculated that the gravitational force is at least 300 times larger than the largest rotation-induced force anywhere on Earth, the latter force being maximal along the equator and approximately equal to 34 N/m(3) there. This compares with a gravitational force of approximately 10(4) N/m(3).

Understanding Water-Energy-Ecology Nexus from an Integrated Earth-Human System Perspective

NASA Astrophysics Data System (ADS)

Li, H. Y.; Zhang, X.; Wan, W.; Zhuang, Y.; Hejazi, M. I.; Leung, L. R.

2017-12-01

Both Earth and human systems exert notable controls on streamflow and stream temperature that influence energy production and ecosystem health. An integrated water model representing river processes and reservoir regulations has been developed and coupled to a land surface model and an integrated assessment model of energy, land, water, and socioeconomics to investigate the energy-water-ecology nexus in the context of climate change and water management. Simulations driven by two climate change projections following the RCP 4.5 and RCP 8.5 radiative forcing scenarios, with and without water management, are analyzed to evaluate the individual and combined effects of climate change and water management on streamflow and stream temperature in the U.S. The simulations revealed important impacts of climate change and water management on hydrological droughts. The simulations also revealed the dynamics of competition between changes in water demand and water availability in the RCP 4.5 and RCP 8.5 scenarios that influence streamflow and stream temperature, with important consequences to thermoelectricity production and future survival of juvenile Salmon. The integrated water model is being implemented to the Accelerated Climate Modeling for Energy (ACME), a coupled Earth System Model, to enable future investigations of the energy-water-ecology nexus in the integrated Earth-Human system.

Preparation of affordable and multifunctional clay-based ceramic filter matrix for treatment of drinking water.

PubMed

Shivaraju, H Puttaiah; Egumbo, Henok; Madhusudan, P; Anil Kumar, K M; Midhun, G

2018-02-01

Affordable clay-based ceramic filters with multifunctional properties were prepared using low-cost and active ingredients. The characterization results clearly revealed well crystallinity, structural elucidation, extensive porosity, higher surface area, higher stability, and durability which apparently enhance the treatment efficiency. The filtration rates of ceramic filter were evaluated under gravity and the results obtained were compared with a typical gravity slow sand filter (GSSF). All ceramic filters showed significant filtration rates of about 50-180 m/h, which is comparatively higher than the typical GSSF. Further, purification efficiency of clay-based ceramic filters was evaluated by considering important drinking water parameters and contaminants. A significant removal potential was achieved by the clay-based ceramic filter with 25% and 30% activated carbon along with active agents. Desired drinking water quality parameters were achieved by potential removal of nitrite (98.5%), nitrate (80.5%), total dissolved solids (62%), total hardness (55%), total organic pollutants (89%), and pathogenic microorganisms (100%) using ceramic filters within a short duration. The remarkable purification and disinfection efficiencies were attributed to the extensive porosity (0.202 cm 3  g -1 ), surface area (124.61 m 2  g -1 ), stability, and presence of active nanoparticles such as Cu, TiO 2 , and Ag within the porous matrix of the ceramic filter.

Accuracy comparison in mapping water bodies using Landsat images and Google Earth Images

NASA Astrophysics Data System (ADS)

Zhou, Z.; Zhou, X.

2016-12-01

A lot of research has been done for the extraction of water bodies with multiple satellite images. The Water Indexes with the use of multi-spectral images are the mostly used methods for the water bodies' extraction. In order to extract area of water bodies from satellite images, accuracy may depend on the spatial resolution of images and relative size of the water bodies. To quantify the impact of spatial resolution and size (major and minor lengths) of the water bodies on the accuracy of water area extraction, we use Georgetown Lake, Montana and coalbed methane (CBM) water retention ponds in the Montana Powder River Basin as test sites to evaluate the impact of spatial resolution and the size of water bodies on water area extraction. Data sources used include Landsat images and Google Earth images covering both large water bodies and small ponds. Firstly we used water indices to extract water coverage from Landsat images for both large lake and small ponds. Secondly we used a newly developed visible-index method to extract water coverage from Google Earth images covering both large lake and small ponds. Thirdly, we used the image fusion method in which the Google Earth Images are fused with multi-spectral Landsat images to obtain multi-spectral images of the same high spatial resolution as the Google earth images. The actual area of the lake and ponds are measured using GPS surveys. Results will be compared and the optimal method will be selected for water body extraction.

DEMONSTRATION BULLETIN: COLLOID POLISHING FILTER METHOD - FILTER FLOW TECHNOLOGY, INC.

EPA Science Inventory

The Filter Flow Technology, Inc. (FFT) Colloid Polishing Filter Method (CPFM) was tested as a transportable, trailer mounted, system that uses sorption and chemical complexing phenomena to remove heavy metals and nontritium radionuclides from water. Contaminated waters can be pro...

Multilevel modeling of retention and disinfection efficacy of silver nanoparticles on ceramic water filters.

PubMed

Mikelonis, Anne M; Lawler, Desmond F; Passalacqua, Paola

2016-10-01

This research examined how variations in synthesis methods of silver nanoparticles affect both the release of silver from ceramic water filters (CWFs) and disinfection efficacy. The silver nanoparticles used were stabilized by four different molecules: citrate, polyvinylpyrrolidone, branched polyethylenimine, and casein. A multilevel statistical model was built to quantify if there was a significant difference in: a) extent of silver lost, b) initial amount of silver lost, c) silver lost for water of different quality, and d) total coliform removal. Experiments were performed on location at Pure Home Water, a CWF factory in Tamale, Ghana using stored rainwater and dugout water (a local surface water). The results indicated that using dugout vs. rainwater significantly affects the initial (p-value 0.0015) and sustained (p-value 0.0124) loss of silver, but that silver type does not have a significant effect. On average, dugout water removed 37.5μg/L more initial silver and had 1.1μg/L more silver in the filtrate than rainwater. Initially, filters achieved 1.9 log reduction values (LRVs) on average, but among different silver and water types this varied by as much as 2.5 LRV units. Overall, bacterial removal effectiveness was more challenging to evaluate, but some data suggest that the branched polyethylenimine silver nanoparticles provided improved initial bacterial removal over filters which were not painted with silver nanoparticles (p-value 0.038). Copyright © 2016 Elsevier B.V. All rights reserved.

Creating high-resolution bare-earth digital elevation models (DEMs) from stereo imagery in an area of densely vegetated deciduous forest using combinations of procedures designed for lidar point cloud filtering

USGS Publications Warehouse

DeWitt, Jessica D.; Warner, Timothy A.; Chirico, Peter G.; Bergstresser, Sarah E.

2017-01-01

For areas of the world that do not have access to lidar, fine-scale digital elevation models (DEMs) can be photogrammetrically created using globally available high-spatial resolution stereo satellite imagery. The resultant DEM is best termed a digital surface model (DSM) because it includes heights of surface features. In densely vegetated conditions, this inclusion can limit its usefulness in applications requiring a bare-earth DEM. This study explores the use of techniques designed for filtering lidar point clouds to mitigate the elevation artifacts caused by above ground features, within the context of a case study of Prince William Forest Park, Virginia, USA. The influences of land cover and leaf-on vs. leaf-off conditions are investigated, and the accuracy of the raw photogrammetric DSM extracted from leaf-on imagery was between that of a lidar bare-earth DEM and the Shuttle Radar Topography Mission DEM. Although the filtered leaf-on photogrammetric DEM retains some artifacts of the vegetation canopy and may not be useful for some applications, filtering procedures significantly improved the accuracy of the modeled terrain. The accuracy of the DSM extracted in leaf-off conditions was comparable in most areas to the lidar bare-earth DEM and filtering procedures resulted in accuracy comparable of that to the lidar DEM.

Global water cycle and the coevolution of the Earth's interior and surface environment.

PubMed

Korenaga, Jun; Planavsky, Noah J; Evans, David A D

2017-05-28

The bulk Earth composition contains probably less than 0.3% of water, but this trace amount of water can affect the long-term evolution of the Earth in a number of different ways. The foremost issue is the occurrence of plate tectonics, which governs almost all aspects of the Earth system, and the presence of water could either promote or hinder the operation of plate tectonics, depending on where water resides. The global water cycle, which circulates surface water into the deep mantle and back to the surface again, could thus have played a critical role in the Earth's history. In this contribution, we first review the present-day water cycle and discuss its uncertainty as well as its secular variation. If the continental freeboard has been roughly constant since the Early Proterozoic, model results suggest long-term net water influx from the surface to the mantle, which is estimated to be 3-4.5×10 14  g yr -1 on the billion years time scale. We survey geological and geochemical observations relevant to the emergence of continents above the sea level as well as the nature of Precambrian plate tectonics. The global water cycle is suggested to have been dominated by regassing, and its implications for geochemical cycles and atmospheric evolution are also discussed.This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'. © 2017 The Author(s).

Development of nitrocellulose membrane filters impregnated with different biosynthesized silver nanoparticles applied to water purification.

PubMed

Fernández, Jorge G; Almeida, César A; Fernández-Baldo, Martín A; Felici, Emiliano; Raba, Julio; Sanz, María I

2016-01-01

Bactericidal water filters were developed. For this purpose, nitrocellulose membrane filters were impregnated with different biosynthesized silver nanoparticles. Silver nanoparticles (AgNPs) from Aspergillus niger (AgNPs-Asp), Cryptococcus laurentii (AgNPs-Cry) and Rhodotorula glutinis (AgNPs-Rho) were used for impregnating nitrocellulose filters. The bactericidal properties of these nanoparticles against Escherichia coli, Enterococcus faecalis and Pseudomona aeruginosa were successfully demonstrated. The higher antimicrobial effect was observed for AgNPs-Rho. This fact would be related not only to the smallest particles, but also to polysaccharides groups that surrounding these particles. Moreover, in this study, complete inhibition of bacterial growth was observed on nitrocellulose membrane filters impregnated with 1 mg L(-1) of biosynthesized AgNPs. This concentration was able to reduce the bacteria colony count by over 5 orders of magnitude, doing suitable for a water purification device. Copyright © 2015 Elsevier B.V. All rights reserved.

Prospects for detecting oxygen, water, and chlorophyll on an exo-Earth

PubMed Central

Brandt, Timothy D.; Spiegel, David S.

2014-01-01

The goal of finding and characterizing nearby Earth-like planets is driving many NASA high-contrast flagship mission concepts, the latest of which is known as the Advanced Technology Large-Aperture Space Telescope (ATLAST). In this article, we calculate the optimal spectral resolution R = λ/δλ and minimum signal-to-noise ratio per spectral bin (SNR), two central design requirements for a high-contrast space mission, to detect signatures of water, oxygen, and chlorophyll on an Earth twin. We first develop a minimally parametric model and demonstrate its ability to fit synthetic and observed Earth spectra; this allows us to measure the statistical evidence for each component’s presence. We find that water is the easiest to detect, requiring a resolution R ≳ 20, while the optimal resolution for oxygen is likely to be closer to R = 150, somewhat higher than the canonical value in the literature. At these resolutions, detecting oxygen will require approximately two times the SNR as water. Chlorophyll requires approximately six times the SNR as oxygen for an Earth twin, only falling to oxygen-like levels of detectability for a low cloud cover and/or a large vegetation covering fraction. This suggests designing a mission for sensitivity to oxygen and adopting a multitiered observing strategy, first targeting water, then oxygen on the more favorable planets, and finally chlorophyll on only the most promising worlds. PMID:25197095

Prospects for detecting oxygen, water, and chlorophyll on an exo-Earth.

PubMed

Brandt, Timothy D; Spiegel, David S

2014-09-16

The goal of finding and characterizing nearby Earth-like planets is driving many NASA high-contrast flagship mission concepts, the latest of which is known as the Advanced Technology Large-Aperture Space Telescope (ATLAST). In this article, we calculate the optimal spectral resolution R = λ/δλ and minimum signal-to-noise ratio per spectral bin (SNR), two central design requirements for a high-contrast space mission, to detect signatures of water, oxygen, and chlorophyll on an Earth twin. We first develop a minimally parametric model and demonstrate its ability to fit synthetic and observed Earth spectra; this allows us to measure the statistical evidence for each component's presence. We find that water is the easiest to detect, requiring a resolution R ≳ 20, while the optimal resolution for oxygen is likely to be closer to R = 150, somewhat higher than the canonical value in the literature. At these resolutions, detecting oxygen will require approximately two times the SNR as water. Chlorophyll requires approximately six times the SNR as oxygen for an Earth twin, only falling to oxygen-like levels of detectability for a low cloud cover and/or a large vegetation covering fraction. This suggests designing a mission for sensitivity to oxygen and adopting a multitiered observing strategy, first targeting water, then oxygen on the more favorable planets, and finally chlorophyll on only the most promising worlds.

Endocrine disruptors in water filters used in the Rio dos Sinos Basin region, Southern Brazil.

PubMed

Furtado, C M; von Mühlen, C

2015-05-01

The activated carbon filter is used in residences as another step in the treatment of drinking water, based on a physical-chemical process to absorb pollutants that are not removed in conventional treatment. Endocrine disruptors (EDCs) are exogenous substances or mixtures of substances that acts on the endocrine system similarly to the endogenously produced hormones, triggering malfunctions and harmful changes to human and animal health. The objective of the present work was to study EDCs through semi-quantitative analysis of residential water filters collected in the region of Rio dos Sinos basin, focusing on two specific classes: hormones and phenols. The solid phase extraction principle was used for the extraction of compounds and gas chromatography coupled with mass spectrometry for the separation and characterization of EDCs. Four samples of residential filters collected from public water distribution and artesian wells, from the cities of Novo Hamburgo and São Leopoldo were analysed. Using the developed methodology, it was possible to detect and comparatively quantify selected EDCs in all studied samples, which indicates the presence of these contaminants in drinking water from different sources.

Tunable filters for multispectral imaging of aeronomical features

NASA Astrophysics Data System (ADS)

Goenka, C.; Semeter, J. L.; Noto, J.; Dahlgren, H.; Marshall, R.; Baumgardner, J.; Riccobono, J.; Migliozzi, M.

2013-10-01

Multispectral imaging of optical emissions in the Earth's upper atmosphere unravels vital information about dynamic phenomena in the Earth-space environment. Wavelength tunable filters allow us to accomplish this without using filter wheels or multiple imaging setups, but with identifiable caveats and trade-offs. We evaluate one such filter, a liquid crystal Fabry-Perot etalon, as a potential candidate for the next generation of imagers for aeronomy. The tunability of such a filter can be exploited in imaging features such as the 6300-6364 Å oxygen emission doublet, or studying the rotational temperature of N2+ in the 4200-4300 Å range, observations which typically require multiple instruments. We further discuss the use of this filter in an optical instrument, called the Liquid Crystal Hyperspectral Imager (LiCHI), which will be developed to make simultaneous measurements in various wavelength ranges.

Laboratory comparison of four iron-based filter materials for water treatment of trace element contaminants

USDA-ARS?s Scientific Manuscript database

A laboratory investigation was conducted to evaluate four iron-based filter materials for trace element contaminant water treatment. The iron-based filter materials evaluated were zero valent iron (ZVI), porous iron composite (PIC), sulfur modified iron (SMI), and iron oxide/hydroxide (IOH). Only fi...

Estimating Attitude, Trajectory, and Gyro Biases in an Extended Kalman Filter using Earth Magnetic Field Data from the Rossi X-Ray Timing Explorer

NASA Technical Reports Server (NTRS)

Deutschmann, Julie; Bar-Itzhack, Itzhack

1997-01-01

Traditionally satellite attitude and trajectory have been estimated with completely separate systems, using different measurement data. The estimation of both trajectory and attitude for low earth orbit satellites has been successfully demonstrated in ground software using magnetometer and gyroscope data. Since the earth's magnetic field is a function of time and position, and since time is known quite precisely, the differences between the computed and measured magnetic field components, as measured by the magnetometers throughout the entire spacecraft orbit, are a function of both the spacecraft trajectory and attitude errors. Therefore, these errors can be used to estimate both trajectory and attitude. This work further tests the single augmented Extended Kalman Filter (EKF) which simultaneously and autonomously estimates spacecraft trajectory and attitude with data from the Rossi X-Ray Timing Explorer (RXTE) magnetometer and gyro-measured body rates. In addition, gyro biases are added to the state and the filter's ability to estimate them is presented.

Catalysts Based on Earth-Abundant Metals for Visible Light-Driven Water Oxidation Reaction.

PubMed

Lin, Junqi; Han, Qing; Ding, Yong

2018-06-04

Exploration of water oxidation catalyst (WOC) with excellent performance is the key for the overall water splitting reaction, which is a feasible strategy to convert solar energy to chemical energy. Although some compounds composed of noble metals, mainly Ru and Ir, have been reported to catalyze water oxidation with high efficiency, catalysts based on low-cost and earth-abundant transition metals are essential for realizing economical and large-scale light-driven water splitting. Various WOCs containing earth-abundant metals (mainly Mn, Fe, Co, Ni, Cu) have been utilized for visible light-driven water oxidation in recent years. In this Personal Account, we summarize our recent developments in WOCs based on earth-abundant transition metals including polyoxometalates (POMs), metal oxides or bimetal oxides, and metal complexes containing multidentate ligand scaffolds for visible light-driven water oxidation reaction. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Water-rich planets: How habitable is a water layer deeper than on Earth?

NASA Astrophysics Data System (ADS)

Noack, L.; Höning, D.; Rivoldini, A.; Heistracher, C.; Zimov, N.; Journaux, B.; Lammer, H.; Van Hoolst, T.; Bredehöft, J. H.

2016-10-01

Water is necessary for the origin and survival of life as we know it. In the search for life-friendly worlds, water-rich planets therefore are obvious candidates and have attracted increasing attention in recent years. The surface H2O layer on such planets (containing a liquid water ocean and possibly high-pressure ice below a specific depth) could potentially be hundreds of kilometres deep depending on the water content and the evolution of the proto-atmosphere. We study possible constraints for the habitability of deep water layers and introduce a new habitability classification relevant for water-rich planets (from Mars-size to super-Earth-size planets). A new ocean model has been developed that is coupled to a thermal evolution model of the mantle and core. Our interior structure model takes into account depth-dependent thermodynamic properties and the possible formation of high-pressure ice. We find that heat flowing out of the silicate mantle can melt an ice layer from below (in some cases episodically), depending mainly on the thickness of the ocean-ice shell, the mass of the planet, the surface temperature and the interior parameters (e.g. radioactive mantle heat sources). The high pressure at the bottom of deep water-ice layers could also impede volcanism at the water-mantle boundary for both stagnant lid and plate tectonics silicate shells. We conclude that water-rich planets with a deep ocean, a large planet mass, a high average density or a low surface temperature are likely less habitable than planets with an Earth-like ocean.

On inclusion of water resource management in Earth system models - Part 1: Problem definition and representation of water demand

NASA Astrophysics Data System (ADS)

Nazemi, A.; Wheater, H. S.

2015-01-01

Human activities have caused various changes to the Earth system, and hence the interconnections between human activities and the Earth system should be recognized and reflected in models that simulate Earth system processes. One key anthropogenic activity is water resource management, which determines the dynamics of human-water interactions in time and space and controls human livelihoods and economy, including energy and food production. There are immediate needs to include water resource management in Earth system models. First, the extent of human water requirements is increasing rapidly at the global scale and it is crucial to analyze the possible imbalance between water demands and supply under various scenarios of climate change and across various temporal and spatial scales. Second, recent observations show that human-water interactions, manifested through water resource management, can substantially alter the terrestrial water cycle, affect land-atmospheric feedbacks and may further interact with climate and contribute to sea-level change. Due to the importance of water resource management in determining the future of the global water and climate cycles, the World Climate Research Program's Global Energy and Water Exchanges project (WRCP-GEWEX) has recently identified gaps in describing human-water interactions as one of the grand challenges in Earth system modeling (GEWEX, 2012). Here, we divide water resource management into two interdependent elements, related firstly to water demand and secondly to water supply and allocation. In this paper, we survey the current literature on how various components of water demand have been included in large-scale models, in particular land surface and global hydrological models. Issues of water supply and allocation are addressed in a companion paper. The available algorithms to represent the dominant demands are classified based on the demand type, mode of simulation and underlying modeling assumptions. We discuss

Sub-micron filter

DOEpatents

Tepper, Frederick [Sanford, FL; Kaledin, Leonid [Port Orange, FL

2009-10-13

Aluminum hydroxide fibers approximately 2 nanometers in diameter and with surface areas ranging from 200 to 650 m.sup.2/g have been found to be highly electropositive. When dispersed in water they are able to attach to and retain electronegative particles. When combined into a composite filter with other fibers or particles they can filter bacteria and nano size particulates such as viruses and colloidal particles at high flux through the filter. Such filters can be used for purification and sterilization of water, biological, medical and pharmaceutical fluids, and as a collector/concentrator for detection and assay of microbes and viruses. The alumina fibers are also capable of filtering sub-micron inorganic and metallic particles to produce ultra pure water. The fibers are suitable as a substrate for growth of cells. Macromolecules such as proteins may be separated from each other based on their electronegative charges.

Design, construction and operation of a new filter approach for treatment of surface waters in Southeast Asia

NASA Astrophysics Data System (ADS)

Frankel, R. J.

1981-05-01

A simple, inexpensive, and efficient method of water treatment for rural communities in Southeast Asia was developed using local materials as filter media. The filter utilizes coconut fiber and burnt rice husks in a two-stage filtering process designed as a gravityfed system without the need for backwashing, and eliminates in most cases the need of any chemicals. The first-stage filter with coconut fiber acts essentially as a substitute for the coagulation and sedimentation phases of conventional water-treatment plants. The second-stage filter, using burnt rice husks, is similar to slow sand filtration with the additional benefits of taste, color and odor removals through the absorption properties of the activated carbon in the medium. This paper reports on the design, construction costs, and operating results of several village size units in Thailand and in the Philippines.

Field application of farmstead runoff to vegetated filter strips: surface and subsurface water quality assessment.

PubMed

Larson, Rebecca A; Safferman, Steven I

2012-01-01

Farmstead runoff poses significant environmental impacts to ground and surface waters. Three vegetated filter strips were assessed for the treatment of dairy farmstead runoff at the soil surface and subsurface at 0.3- or 0. 46-m and 0. 76-m depths for numerous storm events. A medium-sized Michigan dairy was retrofitted with two filter strips on sandy loam soil and a third filter strip was implemented on a small Michigan dairy with sandy soil to collect and treat runoff from feed storage, manure storage, and other impervious farmstead areas. All filter strips were able to eliminate surface runoff via infiltration for all storm events over the duration of the study, eliminating pollutant contributions to surface water. Subsurface effluent was monitored to determine the contributing groundwater concentrations of numerous pollutants including chemical oxygen demand (COD), metals, and nitrates. Subsurface samples have an average reduction of COD concentrations of 20, 11, and 85% for the medium dairy Filter Strip 1 (FS1), medium dairy Filter Strip 2 (FS2), and the small Michigan dairy respectively, resulting in average subsurface concentrations of 355, 3960, and 718 mg L COD. Similar reductions were noted for ammonia and total Kjeldahl nitrogen (TKN) in the subsurface effluent. The small Michigan dairy was able to reduce the pollutant leachate concentrations of COD, TKN, and ammonia over a range of influent concentrations. Increased influent concentrations in the medium Michigan dairy filter strips resulted in an increase in COD, TKN, and ammonia concentrations in the leachate. Manganese was leached from the native soils at all filter strips as evidenced by the increase in manganese concentrations in the leachate. Nitrate concentrations were above standard drinking water limits (10 mg L), averaging subsurface concentrations of 11, 45, and 25 mg L NO-N for FS1, FS2, and the small Michigan dairy, respectively. Copyright © by the American Society of Agronomy, Crop Science

Optimization of adenovirus 40 and 41 recovery from tap water using small disk filters.

PubMed

McMinn, Brian R

2013-11-01

Currently, the U.S. Environmental Protection Agency's Information Collection Rule (ICR) for the primary concentration of viruses from drinking and surface waters uses the 1MDS filter, but a more cost effective option, the NanoCeram® filter, has been shown to recover comparable levels of enterovirus and norovirus from both matrices. In order to achieve the highest viral recoveries, filtration methods require the identification of optimal concentration conditions that are unique for each virus type. This study evaluated the effectiveness of 1MDS and NanoCeram filters in recovering adenovirus (AdV) 40 and 41 from tap water, and optimized two secondary concentration procedures the celite and organic flocculation method. Adjustments in pH were made to both virus elution solutions and sample matrices to determine which resulted in higher virus recovery. Samples were analyzed by quantitative PCR (qPCR) and Most Probable Number (MPN) techniques and AdV recoveries were determined by comparing levels of virus in sample concentrates to that in the initial input. The recovery of adenovirus was highest for samples in unconditioned tap water (pH 8) using the 1MDS filter and celite for secondary concentration. Elution buffer containing 0.1% sodium polyphosphate at pH 10.0 was determined to be most effective overall for both AdV types. Under these conditions, the average recovery for AdV40 and 41 was 49% and 60%, respectively. By optimizing secondary elution steps, AdV recovery from tap water could be improved at least two-fold compared to the currently used methodology. Identification of the optimal concentration conditions for human AdV (HAdV) is important for timely and sensitive detection of these viruses from both surface and drinking waters. Published by Elsevier B.V.

The Potential Benefits of Earth Observations for the Water-Energy-Food Nexus and Beyond

NASA Astrophysics Data System (ADS)

Lawford, R. G.

2016-12-01

Earth Observations have been shown to have the potential to play an important role in the management of the Water-Energy-Food (W-E-F) Nexus. To date, their primary application has come through support to decisions related to the better use of water in the production of food and in the extraction of energy. However, to be fully effective, the uses of Earth observations should be coordinated across the sectors and appropriately applied at multiple levels of the governance process. This observation argues for a new approach to governance and management of the W-E-F Nexus that implements collaborative planning based on broader usage of Earth observations. The Future Earth W-E-F Nexus Cluster project has documented a number of ways in which Earth observations can support decision-making that benefits the management of these sectors and has identified gaps in the data and information systems needed for this purpose. This presentation will summarize those findings and discuss how the role of Earth observations could be strengthened and expanded to the Sustainable Development Goals and Integrated Water Resources Management.

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

USDA-ARS?s Scientific Manuscript database

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

A comparison study of the start-up of a MnOx filter for catalytic oxidative removal of ammonium from groundwater and surface water.

PubMed

Cheng, Ya; Li, Ye; Huang, Tinglin; Sun, Yuankui; Shi, Xinxin; Shao, Yuezong

2018-03-01

As an efficient method for ammonium (NH 4 + ) removal, contact catalytic oxidation technology has drawn much attention recently, due to its good low temperature resistance and short start-up period. Two identical filters were employed to compare the process for ammonium removal during the start-up period for ammonium removal in groundwater (Filter-N) and surface water (Filter-S) treatment. Two types of source water (groundwater and surface water) were used as the feed waters for the filtration trials. Although the same initiating method was used, Filter-N exhibited much better ammonium removal performance than Filter-S. The differences in catalytic activity among these two filters were probed using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and compositional analysis. XRD results indicated that different manganese oxide species were formed in Filter-N and Filter-S. Furthermore, the Mn3p XPS spectra taken on the surface of the filter films revealed that the average manganese valence of the inactive manganese oxide film collected from Filter-S (FS-MnO x ) was higher than in the film collected from Filter-N (FN-MnO x ). Mn(IV) was identified as the predominant oxidation state in FS-MnO x and Mn(III) was identified as the predominant oxidation state in FN-MnO x . The results of compositional analyses suggested that polyaluminum ferric chloride (PAFC) used during the surface water treatment was an important factor in the mineralogy and reactivity of MnO x . This study provides the theoretical basis for promoting the wide application of the technology and has great practical significance. Copyright © 2017. Published by Elsevier B.V.

An impact-induced terrestrial atmosphere and iron-water reactions during accretion of the Earth

NASA Technical Reports Server (NTRS)

Lange, M. A.; Ahrens, T. J.

1985-01-01

Shock wave data and theoretical calculations were used to derive models of an impact-generated terrestrial atmosphere during accretion of the Earth. The models showed that impacts of infalling planetesimals not only provided the entire budget of terrestrial water but also led to a continuous depletion of near-surface layers of water-bearing minerals of their structural water. This resulted in a final atmospheric water reservoir comparable to the present day total water budget of the Earth. The interaction of metallic iron with free water at the surface of the accreting Earth is considered. We carried out model calcualtions simulating these processes during accretion. It is assumed that these processes are the prime source of the terrestrial FeO component of silicates and oxides. It is demonstrated that the iron-water reaction would result in the absence of atmospheric/hydrospheric water, if homogeneous accretion is assumed. In order to obtain the necessary amount of terrestrial water, slightly heterogeneous accretion with initially 36 wt% iron planetesimals, as compared with a homogeneous value of 34 wt% is required.

The use of nutshell carbons in drinking water filters for removal of trace metals.

PubMed

Ahmedna, Mohamed; Marshall, Wayne E; Husseiny, Abdo A; Rao, Ramu M; Goktepe, Ipek

2004-02-01

Filtration of drinking water by point-of-use (POU) or point-of-entry (POE) systems is becoming increasingly popular in the United States. Drinking water is filtered to remove both organic and inorganic contaminants. The objective of this study was to evaluate the use of granular activated carbon from nutshells (almond, English walnut, pecan) in a POU water filtration system to determine its effectiveness in removing select, potentially toxic metal ions, namely, copper (Cu2+), lead (Pb2+) or zinc (Zn2+) found in drinking water. The nutshell-based carbon system was designated "Envirofilter" and was compared to four commercial POU systems with brand names of BRITA, Omni Filter, PUR and Teledyne Water Pik. Eight prototype "Envirofilters", consisting of individual or binary mixtures of carbons made from acid-activated almond or pecan shells and steam-activated pecan or walnut shells were constructed and evaluated for adsorption of the three metal ions. The results indicated that a binary mixture of carbons from acid-activated almond and either steam-activated pecan or walnut shells were the most effective in removing these metals from drinking water of all the POU systems evaluated. Binary mixtures of acid-activated almond shell-based carbon with either steam-activated pecan shell- or walnut shell-based carbon removed nearly 100% of lead ion, 90-95% of copper ion and 80-90% of zinc ion. Overall the performance data on the "Envirofilters" suggest that these prototypes require less carbon than commercial filters to achieve the same metal adsorption efficiency and may also be a less expensive product.

Mode and Intermediate Waters in Earth System Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gnanadesikan, Anand; Sarmiento, Jorge L.

This report describes work done as part of a joint Princeton-Johns Hopkins project to look at the impact of mode and intermediate waters in Earth System Models. The Johns Hopkins portion of this work focussed on the role of lateral mixing in ventilating such waters, with important implications for hypoxia, the uptake of anthropogenic carbon, the dynamics of El Nino and carbon pumps. The Johns Hopkins group also collaborated with the Princeton Group to help develop a watermass diagnostics framework.

Use, microbiological effectiveness and health impact of a household water filter intervention in rural Rwanda-A matched cohort study.

PubMed

Kirby, Miles A; Nagel, Corey L; Rosa, Ghislaine; Umupfasoni, Marie Mediatrice; Iyakaremye, Laurien; Thomas, Evan A; Clasen, Thomas F

2017-08-01

Unsafe drinking water is a substantial health risk contributing to child diarrhoea. We investigated impacts of a program that provided a water filter to households in rural Rwandan villages. We assessed drinking water quality and reported diarrhoea 12-24 months after intervention delivery among 269 households in the poorest tertile with a child under 5 from 9 intervention villages and 9 matched control villages. We also documented filter coverage and use. In Round 1 (12-18 months after delivery), 97.4% of intervention households reported receiving the filter, 84.5% were working, and 86.0% of working filters contained water. Sensors confirmed half of households with working filters filled them at least once every other day on average. Coverage and usage was similar in Round 2 (19-24 months after delivery). The odds of detecting faecal indicator bacteria in drinking water were 78% lower in the intervention arm than the control arm (odds ratio (OR) 0.22, 95% credible interval (CrI) 0.10-0.39, p<0.001). The intervention arm also had 50% lower odds of reported diarrhoea among children <5 than the control arm (OR=0.50, 95% CrI 0.23-0.90, p=0.03). The protective effect of the filter is also suggested by reduced odds of reported diarrhoea-related visits to community health workers or clinics, although these did not reach statistical significance. Copyright © 2017 Elsevier GmbH. All rights reserved.

Impact of temperature on nitrification in biological activated carbon (BAC) filters used for drinking water treatment.

PubMed

Andersson, A; Laurent, P; Kihn, A; Prévost, M; Servais, P

2001-08-01

The impact of temperature on nitrification in biological granular activated carbon (GAC) filters was evaluated in order to improve the understanding of the nitrification process in drinking water treatment. The study was conducted in a northern climate where very cold water temperatures (below 2 degrees C) prevail for extended periods and rapid shifts of temperature are frequent in the spring and fall. Ammonia removals were monitored and the fixed nitrifying biomass was measured using a method of potential nitrifying activity. The impact of temperature was evaluated on two different filter media: an opened superstructure wood-based activated carbon and a closed superstructure activated carbon-based on bituminous coal. The study was conducted at two levels: pilot scale (first-stage filters) and full-scale (second-stage filters) and the results indicate a strong temperature impact on nitrification activity. Ammonia removal capacities ranged from 40 to 90% in pilot filters, at temperatures above 10 degrees C, while more than 90% ammonia was removed in the full-scale filters for the same temperature range. At moderate temperatures (4-10 degrees C), the first stage pilot filters removed 10-40% of incoming ammonia for both media (opened and closed superstructure). In the full-scale filters, a difference between the two media in nitrification performances was observed at moderate temperatures: the ammonia removal rate in the opened superstructure support (more than 90%) was higher than in the closed superstructure support (45%). At low temperatures (below 4 degrees C) both media performed poorly. Ammonia removal capacities were below 30% in both pilot- and full-scale filters.

Why Isn't the Earth Completely Covered in Water?

NASA Technical Reports Server (NTRS)

Nuth, Joseph A., III; Rietmeijer, Frans J. M.; Marnocha, Cassandra L.

2012-01-01

If protoplanets formed from 10 to 20 kilometer diameter planetesimals in a runaway accretion process prior to their oligarchic growth into the terrestrial planets, it is only logical to ask where these planetesimals may have formed in order to assess the initial composition of the Earth. We have used Weidenschilling's model for the formation of comets (1997) to calculate an efficiency factor for the formation of planetesimals from the solar nebula, then used this factor to calculate the feeding zones that contribute to material contained within 10, 15 and 20 kilometer diameter planetesimals at 1 A.U. as a function of nebular mass. We find that for all reasonable nebular masses, these planetesimals contain a minimum of 3% water as ice by mass. The fraction of ice increases as the planetesimals increase in size and as the nebular mass decreases, since both factors increase the feeding zones from which solids in the final planetesimals are drawn. Is there really a problem with the current accretion scenario that makes the Earth too dry, or is it possible that the nascent Earth lost significant quantities of water in the final stages of accretion?

Study of slow sand filtration with backwash and the influence of the filter media on the filter recovery and cleaning.

PubMed

de Souza, Fernando Hymnô; Pizzolatti, Bruno Segalla; Schöntag, Juliana Marques; Sens, Maurício Luiz

2016-01-01

Slow sand filters are considered as a great alternative for supplying drinking water in rural and/or isolated areas where raw water that is treatable with this technique is available. Some studies used backwashing as an alternative for cleaning the slow sand filter with the goal of applying the technology in small communities, since filters that supply water to a small number of people do not require much space. In this study the influence of the effective diameter on water quality in the filters and cleaning system was evaluated. A pilot system with six filters was built: three filters were conventionally cleaned by scraping and the other three were cleaned by backwashing, each with a different effective diameter of filter medium. Most filters had an average turbidity of less than 1.0 NTU, the turbidity required at the output of the filters by the Brazilian Ministry of Health Ordinance. In the study, the filters cleaned by scraping with smaller-diameter filter beds effectively filtered water better but had worse effective production. The opposite occurs in the case of backwashed filters.

Anthropogenic gadolinium anomalies and rare earth elements in the water of Atibaia River and Anhumas Creek, Southeast Brazil.

PubMed

de Campos, Francisco Ferreira; Enzweiler, Jacinta

2016-05-01

The concentrations of rare earth elements (REE), measured in water samples from Atibaia River and its tributary Anhumas Creek, Brazil, present excess of dissolved gadolinium. Such anthropogenic anomalies of Gd in water, already described in other parts of the world, result from the use of stable and soluble Gd chelates as contrast agents in magnetic resonance imaging. Atibaia River constitutes the main water supply of Campinas Metropolitan area, and its basin receives wastewater effluents. The REE concentrations in water samples were determined in 0.22-μm pore size filtered samples, without and after preconcentration by solid-phase extraction with bis-(2-ethyl-hexyl)-phosphate. This preconcentration method was unable to retain the anthropogenic Gd quantitatively. The probable reason is that the Gd chelates dissociate slowly in acidic media to produce the free ion that is retained by the phosphate ester. Strong correlations between Gd and constituents or parameters associated with effluents confirmed the source of most Gd in water samples as anthropogenic. The shale-normalized REE patterns of Atibaia River and Anhumas Creek water samples showed light and heavy REE enrichment trends, respectively. Also, positive Ce anomalies in many Atibaia River samples, as well as the strong correlations of the REE (except Gd) with terrigenous elements, imply that inorganic colloidal particles contributed to the REE measured values.

Comparison of sand-based water filters for point-of-use arsenic removal in China.

PubMed

Smith, Kate; Li, Zhenyu; Chen, Bohan; Liang, Honggang; Zhang, Xinyi; Xu, Ruifei; Li, Zhilin; Dai, Huanfang; Wei, Caijie; Liu, Shuming

2017-02-01

Contamination of groundwater wells by arsenic is a major problem in China. This study compared arsenic removal efficiency of five sand-based point-of-use filters with the aim of selecting the most effective filter for use in a village in Shanxi province, where the main groundwater source had arsenic concentration >200 μg/L. A biosand filter, two arsenic biosand filters, a SONO-style filter and a version of the biosand filter with nails embedded in the sand were tested. The biosand filter with embedded nails was the most consistent and effective under the study conditions, likely due to increased contact time between water and nails and sustained corrosion. Effluent arsenic was below China's standard of 50 μg/L for more than six months after construction. The removal rate averaged 92% and was never below 86%. In comparison, arsenic removal for the nail-free biosand filter was never higher than 53% and declined with time. The arsenic biosand filter, in which nails sit in a diffuser basin above the sand, performed better but effluent arsenic almost always exceeded the standard. This highlights the positive impact on arsenic removal of embedding nails within the top layer of biosand filter sand and the promise of this low-cost filtration method for rural areas affected by arsenic contamination. Copyright © 2016 Elsevier Ltd. All rights reserved.

Earth's field NMR detection of oil under arctic ice-water suppression

NASA Astrophysics Data System (ADS)

Conradi, Mark S.; Altobelli, Stephen A.; Sowko, Nicholas J.; Conradi, Susan H.; Fukushima, Eiichi

2018-03-01

Earth's field NMR has been developed to detect oil trapped under or in Arctic sea-ice. A large challenge, addressed here, is the suppression of the water signal that dominates the oil signal. Selective suppression of water is based on relaxation time T1 because of the negligible chemical shifts in the weak earth's magnetic field, making all proton signals overlap spectroscopically. The first approach is inversion-null recovery, modified for use with pre-polarization. The requirements for efficient inversion over a wide range of B1 and subsequent adiabatic reorientation of the magnetization to align with the static field are stressed. The second method acquires FIDs at two durations of pre-polarization and cancels the water component of the signal after the data are acquired. While less elegant, this technique imposes no stringent requirements. Similar water suppression is found in simulations for the two methods. Oil detection in the presence of water is demonstrated experimentally with both techniques.

Earth's field NMR detection of oil under arctic ice-water suppression.

PubMed

Conradi, Mark S; Altobelli, Stephen A; Sowko, Nicholas J; Conradi, Susan H; Fukushima, Eiichi

2018-03-01

Earth's field NMR has been developed to detect oil trapped under or in Arctic sea-ice. A large challenge, addressed here, is the suppression of the water signal that dominates the oil signal. Selective suppression of water is based on relaxation time T 1 because of the negligible chemical shifts in the weak earth's magnetic field, making all proton signals overlap spectroscopically. The first approach is inversion-null recovery, modified for use with pre-polarization. The requirements for efficient inversion over a wide range of B 1 and subsequent adiabatic reorientation of the magnetization to align with the static field are stressed. The second method acquires FIDs at two durations of pre-polarization and cancels the water component of the signal after the data are acquired. While less elegant, this technique imposes no stringent requirements. Similar water suppression is found in simulations for the two methods. Oil detection in the presence of water is demonstrated experimentally with both techniques. Copyright © 2018 Elsevier Inc. All rights reserved.

Removal of fluoride, arsenic and coliform bacteria by modified homemade filter media from drinking water.

PubMed

Devi, Rani; Alemayehu, Esayas; Singh, Vijender; Kumar, Ashok; Mengistie, Embialle

2008-05-01

An attempt was made to investigate the removal of fluoride, arsenic and coliform bacteria from drinking water using modified homemade filter media. Batch mode experimental study was conducted to test the efficiency of modified homemade filter for reduction of impurities under the operating condition of treatment time. The physico-chemical and biological analysis of water samples had been done before and after the treatment with filter media, using standard methods. Optimum operating treatment time was determined for maximum removal of these impurities by running the experiment for 2, 4, 6, 8, 10 and 12h, respectively. The maximum reduction of fluoride, arsenic and coliform bacteria in percentage was 85.60%, 93.07% and 100% and their residual values were 0.72 mg/l, 0.009 mg/l and 0 coliform cells/100ml, respectively after a treatment time of 10h. These residual values were under the permissible limits prescribed by WHO. Hence this could be a cheap, easy and an efficient technique for removal of fluoride, arsenic and coliform bacteria from drinking water.

Activated charcoal filters: Water treatment, pollution control, and industrial applications. (Latest citations from the Patent Bibliographic database with exemplary claims. ) Published Search

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The bibliography contains citations of selected patents concerning activated charcoal filters and their applications in water treatment, pollution control, and industrial processes. Filtering methods and equipment for air and water purification, industrial distillation and extraction, industrial leaching, and filtration of toxic materials and contaminants are described. Applications include drinking water purification, filtering beverages, production of polymer materials, solvent and metal recovery, waste conversion, automotive fuel and exhaust systems, swimming pool filtration, tobacco smoke filters, kitchen ventilators, medical filtration treatment, and odor absorbing materials. (Contains 250 citations and includes a subject term index and title list.)

Effect of production variables on microbiological removal in locally-produced ceramic filters for household water treatment.

PubMed

Lantagne, Daniele; Klarman, Molly; Mayer, Ally; Preston, Kelsey; Napotnik, Julie; Jellison, Kristen

2010-06-01

Diarrhoeal diseases cause an estimated 1.87 million child deaths per year. Point-of-use filtration using locally made ceramic filters improves microbiological quality of stored drinking water and prevents diarrhoeal disease. Scaling-up ceramic filtration is inhibited by lack of universal quality control standards. We investigated filter production variables to determine their affect on microbiological removal during 5-6 weeks of simulated normal use. Decreases in the clay:sawdust ratio and changes in the burnable decreased effectiveness of the filter. Method of silver application and shape of filter did not impact filter effectiveness. A maximum flow rate of 1.7 l(-hr) was established as a potential quality control measure for one particular filter to ensure 99% (2- log(10)) removal of total coliforms. Further research is indicated to determine additional production variables associated with filter effectiveness and develop standardized filter production procedures prior to scaling-up.

Dielectric properties of water under extreme conditions and transport of carbonates in the deep Earth.

PubMed

Pan, Ding; Spanu, Leonardo; Harrison, Brandon; Sverjensky, Dimitri A; Galli, Giulia

2013-04-23

Water is a major component of fluids in the Earth's mantle, where its properties are substantially different from those at ambient conditions. At the pressures and temperatures of the mantle, experiments on aqueous fluids are challenging, and several fundamental properties of water are poorly known; e.g., its dielectric constant has not been measured. This lack of knowledge of water dielectric properties greatly limits our ability to model water-rock interactions and, in general, our understanding of aqueous fluids below the Earth's crust. Using ab initio molecular dynamics, we computed the dielectric constant of water under the conditions of the Earth's upper mantle, and we predicted the solubility products of carbonate minerals. We found that MgCO3 (magnesite)--insoluble in water under ambient conditions--becomes at least slightly soluble at the bottom of the upper mantle, suggesting that water may transport significant quantities of oxidized carbon. Our results suggest that aqueous carbonates could leave the subducting lithosphere during dehydration reactions and could be injected into the overlying lithosphere. The Earth's deep carbon could possibly be recycled through aqueous transport on a large scale through subduction zones.

CYANOBACTERIA PASSAGE THROUGH DRINKING WATER FILTERS DURING PERTURBATION EPISODES AS A FUNCTION OF CELL MORPHOLOGY, COAGULANT AND INITIAL FILTER LOADING RATE

EPA Science Inventory

Eight pilot-scale in-line filtration trials were performed to evaluate the passage of cyanobacterial cells through drinking water filters after sudden increases in hydraulic loading rates. Trials were performed at 30 degrees C using two coagulant combinations (aluminum sulfate a...

NASA's Earth Science Enterprise's Water and Energy Cycle Focus Area

NASA Astrophysics Data System (ADS)

Entin, J. K.

2004-05-01

Understanding the Water and Energy cycles is critical towards improving our understanding of climate change, as well as the consequences of climate change. In addition, using results from water and energy cycle research can help improve water resource management, agricultural efficiency, disaster management, and public health. To address this, NASA's Earth Science Enterprise (ESE) has an end-to-end Water and Energy Cycle Focus Area, which along with the ESE's other five focus areas will help NASA answer key Earth Science questions. In an effort to build upon the pre-existing discipline programs, which focus on precipitation, radiation sciences, and terrestrial hydrology, NASA has begun planning efforts to create an implementation plan for integrative research to improve our understanding of the water and energy cycles. The basics of this planning process and the core aspects of the implementation plan will be discussed. Roadmaps will also be used to show the future direction for the entire focus area. Included in the discussion, will be aspects of the end-to-end nature of the Focus Area that encompass current and potential actives to extend research results to operational agencies to enable improved performance of policy and management decision support systems.

Bacterial diversity and active biomass in full-scale granular activated carbon filters operated at low water temperatures.

PubMed

Kaarela, Outi E; Härkki, Heli A; Palmroth, Marja R T; Tuhkanen, Tuula A

2015-01-01

Granular activated carbon (GAC) filtration enhances the removal of natural organic matter and micropollutants in drinking water treatment. Microbial communities in GAC filters contribute to the removal of the biodegradable part of organic matter, and thus help to control microbial regrowth in the distribution system. Our objectives were to investigate bacterial community dynamics, identify the major bacterial groups, and determine the concentration of active bacterial biomass in full-scale GAC filters treating cold (3.7-9.5°C), physicochemically pretreated, and ozonated lake water. Three sampling rounds were conducted to study six GAC filters of different operation times and flow modes in winter, spring, and summer. Total organic carbon results indicated that both the first-step and second-step filters contributed to the removal of organic matter. Length heterogeneity analysis of amplified 16S rRNA genes illustrated that bacterial communities were diverse and considerably stable over time. α-Proteobacteria, β-Proteobacteria, and Nitrospira dominated in all of the GAC filters, although the relative proportion of dominant phylogenetic groups in individual filters differed. The active bacterial biomass accumulation, measured as adenosine triphosphate, was limited due to low temperature, low flux of nutrients, and frequent backwashing. The concentration of active bacterial biomass was not affected by the moderate seasonal temperature variation. In summary, the results provided an insight into the biological component of GAC filtration in cold water temperatures and the operational parameters affecting it.

Earth - South America (first frame of Earth Spin Movie)

NASA Technical Reports Server (NTRS)

1990-01-01

This color image of the Earth was obtained by Galileo at about 6:10 a.m. Pacific Standard Time on Dec. 11, 1990, when the spacecraft was about 1.3 million miles from the planet during the first of two Earth flybys on its way to Jupiter. The color composite used images taken through the red, green and violet filters. South America is near the center of the picture, and the white, sunlit continent of Antarctica is below. Picturesque weather fronts are visible in the South Atlantic, lower right. This is the first frame of the Galileo Earth spin movie, a 500- frame time-lapse motion picture showing a 25-hour period of Earth's rotation and atmospheric dynamics.

Assessment of intermittently loaded woodchip and sand filters to treat dairy soiled water.

PubMed

Murnane, J G; Brennan, R B; Healy, M G; Fenton, O

2016-10-15

Land application of dairy soiled water (DSW) is expensive relative to its nutrient replacement value. The use of aerobic filters is an effective alternative method of treatment and potentially allows the final effluent to be reused on the farm. Knowledge gaps exist concerning the optimal design and operation of filters for the treatment of DSW. To address this, 18 laboratory-scale filters, with depths of either 0.6 m or 1 m, were intermittently loaded with DSW over periods of up to 220 days to evaluate the impacts of depth (0.6 m versus 1 m), organic loading rates (OLRs) (50 versus 155 g COD m(-2) d(-1)), and media type (woodchip versus sand) on organic, nutrient and suspended solids (SS) removals. The study found that media depth was important in contaminant removal in woodchip filters. Reductions of 78% chemical oxygen demand (COD), 95% SS, 85% total nitrogen (TN), 82% ammonium-nitrogen (NH4N), 50% total phosphorus (TP), and 54% dissolved reactive phosphorus (DRP) were measured in 1 m deep woodchip filters, which was greater than the reductions in 0.6 m deep woodchip filters. Woodchip filters also performed optimally when loaded at a high OLR (155 g COD m(-2) d(-1)), although the removal mechanism was primarily physical (i.e. straining) as opposed to biological. When operated at the same OLR and when of the same depth, the sand filters had better COD removals (96%) than woodchip (74%), but there was no significant difference between them in the removal of SS and NH4N. However, the likelihood of clogging makes sand filters less desirable than woodchip filters. Using the optimal designs of both configurations, the filter area required per cow for a woodchip filter is more than four times less than for a sand filter. Therefore, this study found that woodchip filters are more economically and environmentally effective in the treatment of DSW than sand filters, and optimal performance may be achieved using woodchip filters with a depth of at least 1�

A magma ocean and the Earth's internal water budget

NASA Technical Reports Server (NTRS)

Ahrens, Thomas J.

1992-01-01

There are lines of evidence which relate bounds on the primordial water content of the Earth's mantle to a magma ocean and the accompanying Earth accretion process. We assume initially (before a magma ocean could form) that as the Earth accreted, it grew from volatile- (H2O, CO2, NH3, CH4, SO2, plus noble) gas-rich planetesimals, which accreted to form an initial 'primitive accretion core' (PAC). The PAC retained the initial complement of planetesimal gaseous components. Shock wave experiments in which both solid, and more recently, the gaseous components of materials such as serpentine and the Murchison meteorite have demonstrated that planetesimal infall velocities of less than 0.5 km/sec, induce shock pressures of less than 0.5 GPa and result in virtually complete retention of planetary gases.

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

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

PubMed Central

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

2013-01-01

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

Earth, Air, Fire and Water in Our Elements

ERIC Educational Resources Information Center

Lievesley, Tara

2007-01-01

The idea that everything is made of the four "elements", earth, air, fire and water, goes back to the ancient Greeks. In this article, the author talks about the origins of ideas about the elements. The author provides an account that attempts to summarise thousands of years of theoretical development of the elements in a thousand words or so.

A new methodology for quantifying the impact of water repellency on the filtering function of soils

NASA Astrophysics Data System (ADS)

Müller, Karin; Deurer, Markus; Kawamoto, Ken; Hiradate, Syuntaro; Komatsu, Toshiko; Clothier, Brent

2014-05-01

Soils deliver a range of ecosystem services, and some of the most valuable relate to the regulating services resulting from the buffering and filtering of solutes by soil. However, it is commonly accepted that soil water repellency (SWR) can lead to finger flow and preferential flow. Yet, there have been few attempts to quantify the impact of such flow phenomena on the buffering and filtering of solutes. No method is available to quantify directly how SWR affects the transport of reactive solutes. We have closed this gap and developed a new method for quantifying solute transport by novel experiments with water-repellent soils. It involves sequentially applying two liquids, one water, and the other a reference fully wetting liquid, namely, aqueous ethanol, to the same intact soil core with air-drying between the application of the two liquids. Our results highlight that sorption experiments are necessary to complement our new method to ascertain directly the impact of SWR on the filtering of a solute. We conducted transport and sorption experiments, by applying our new method, with the herbicide 2,4-Dichlorophenoxyacetic acid and two Andosol top-soils; one from Japan and the other one from New Zealand. Breakthrough curves from the water experiments were characterized by preferential flow with high initial concentrations, tailing and a long prevalence of solutes remaining in the soil. Our results clearly demonstrate and quantify the impact of SWR on the leaching of this herbicide. This technique for quantifying the reduction of the soil's filtering efficiency by SWR enables assessment of the increased risk of groundwater contamination by solutes exogenously applied to water-repellent soils.

Development of biomass in a drinking water granular active carbon (GAC) filter.

PubMed

Velten, Silvana; Boller, Markus; Köster, Oliver; Helbing, Jakob; Weilenmann, Hans-Ulrich; Hammes, Frederik

2011-12-01

Indigenous bacteria are essential for the performance of drinking water biofilters, yet this biological component remains poorly characterized. In the present study we followed biofilm formation and development in a granular activated carbon (GAC) filter on pilot-scale during the first six months of operation. GAC particles were sampled from four different depths (10, 45, 80 and 115 cm) and attached biomass was measured with adenosine tri-phosphate (ATP) analysis. The attached biomass accumulated rapidly on the GAC particles throughout all levels in the filter during the first 90 days of operation and maintained a steady state afterward. Vertical gradients of biomass density and growth rates were observed during start-up and also in steady state. During steady state, biomass concentrations ranged between 0.8-1.83 x 10(-6) g ATP/g GAC in the filter, and 22% of the influent dissolved organic carbon (DOC) was removed. Concomitant biomass production was about 1.8 × 10(12) cells/m(2)h, which represents a yield of 1.26 × 10(6) cells/μg. The bacteria assimilated only about 3% of the removed carbon as biomass. At one point during the operational period, a natural 5-fold increase in the influent phytoplankton concentration occurred. As a result, influent assimilable organic carbon concentrations increased and suspended bacteria in the filter effluent increased 3-fold as the direct consequence of increased growth in the biofilter. This study shows that the combination of different analytical methods allows detailed quantification of the microbiological activity in drinking water biofilters. Copyright © 2011 Elsevier Ltd. All rights reserved.

Predation and transport of persistent pathogens in GAC and slow sand filters: a threat to drinking water safety?

PubMed

Bichai, Françoise; Dullemont, Yolanda; Hijnen, Wim; Barbeau, Benoit

2014-11-01

Zooplankton has been shown to transport internalized pathogens throughout engineered drinking water systems. In this study, experimental measurements from GAC and SSF filtration tests using high influent concentrations of Cryptosporidium (1.3 × 10(6) and 3.3 × 10(4) oocysts L(-1)) and Giardia (4.8 × 10(4) cysts L(-1)) are presented and compared. A predation and transport conceptual model was developed to extrapolate these results to environmental conditions of typical (oo)cyst concentrations in surface water in order to predict concentrations of internalized (oo)cysts in filtered water. Pilot test results were used to estimate transport and survival ratios of internalized (oo)cysts following predation by rotifers in the filter beds. Preliminary indications of lower transport and survival ratios in SSF were found as compared with GAC filters. A probability of infection due to internalized (oo)cysts in filtered water was calculated under likeliest environmental conditions and under a worst-case scenario. Estimated risks under the likeliest environmental scenario were found to fall below the tolerable risk target of 10(-4) infections per person per year. A discussion is presented on the health significance of persistent pathogens that are internalized by zooplankton during granular filtration processes and released into treated water. Copyright © 2014 Elsevier Ltd. All rights reserved.

Modal Filters for Infrared Interferometry

NASA Technical Reports Server (NTRS)

Ksendzov, Alexander; MacDonald, Daniel R.; Soibel, Alexander

2009-01-01

Modal filters in the approximately equal to 10-micrometer spectral range have been implemented as planar dielectric waveguides in infrared interferometric applications such as searching for Earth-like planets. When looking for a small, dim object ("Earth") in close proximity to a large, bright object ("Sun"), the interferometric technique uses beams from two telescopes combined with a 180 phase shift in order to cancel the light from a brighter object. The interferometer baseline can be adjusted so that, at the same time, the light from the dimmer object arrives at the combiner in phase. This light can be detected and its infrared (IR) optical spectra can be studied. The cancellation of light from the "Sun" to approximately equal to 10(exp 6) is required; this is not possible without special devices-modal filters- that equalize the wavefronts arriving from the two telescopes. Currently, modal filters in the approximately equal to 10-micrometer spectral range are implemented as single- mode fibers. Using semiconductor technology, single-mode waveguides for use as modal filters were fabricated. Two designs were implemented: one using an InGaAs waveguide layer matched to an InP substrate, and one using InAlAs matched to an InP substrate. Photon Design software was used to design the waveguides, with the main feature all designs being single-mode operation in the 10.5- to 17-micrometer spectral range. Preliminary results show that the filter's rejection ratio is 26 dB.

A NASA Space Sleuth Hunts the Trail of Earth Water

NASA Image and Video Library

2009-08-13

This vertical profile view from the Tropospheric Emission Spectrometer TES instrument on NASA Aura satellite depicts the distribution of water vapor molecules over Earth tropics across one transect of the satellite orbit on January 6, 2006.

The occurrence of UV filters in natural and drinking water in São Paulo State (Brazil).

PubMed

da Silva, Claudia Pereira; Emídio, Elissandro Soares; de Marchi, Mary Rosa Rodrigues

2015-12-01

Ultraviolet (UV) filters are widely used in the formulation of personal care products (PCPs) to prevent damage to the skin, lips, and hair caused by excessive UV radiation. Therefore, large amounts of these substances are released daily into the aquatic environment through either recreational activities or the release of domestic sewage. The concern regarding the presence of such substances in the environment and the exposure of aquatic organisms is based on their potential for bioaccumulation and their potential as endocrine disruptors. Although there are several reports regarding the occurrence and fate of UV filters in the aquatic environment, these compounds are still overlooked in tropical areas. In this study, we investigated the occurrence of the organic UV filters benzophenone-3 (BP-3), ethylhexyl salicylate (ES), ethylhexyl methoxycinnamate (EHMC), and octocrylene (OC) in six water treatment plants in various cities in Southeast Brazil over a period of 6 months to 1 year. All of the UV filters studied were detected at some time during the sampling period; however, only EHMC and BP-3 were found in quantifiable concentrations, ranging from 55 to 101 and 18 to 115 ng L(-1), respectively. Seasonal variation of BP-3 was most clearly noticed in the water treatment plant in Araraquara, São Paulo, where sampling was performed for 12 months. BP-3 was not quantifiable in winter but was quantifiable in summer. The levels of BP-3 were in the same range in raw, treated and chlorinated water, indicating that the compound was not removed by the water treatment process.

Water Content of Earth's Continental Mantle Is Controlled by the Circulation of Fluids or Melts

NASA Technical Reports Server (NTRS)

Peslier, Anne; Woodland, Alan B.; Bell, David R.; Lazarov, Marina; Lapen, Thomas J.

2014-01-01

A key mission of the ARES Directorate at JSC is to constrain models of the formation and geological history of terrestrial planets. Water is a crucial parameter to be measured with the aim to determine its amount and distribution in the interior of Earth, Mars, and the Moon. Most of that "water" is not liquid water per se, but rather hydrogen dissolved as a trace element in the minerals of the rocks at depth. Even so, the middle layer of differentiated planets, the mantle, occupies such a large volume and mass of each planet that when it is added at the planetary scale, oceans worth of water could be stored in its interior. The mantle is where magmas originate. Moreover, on Earth, the mantle is where the boundary between tectonic plates and the underlying asthenosphere is located. Even if mantle rocks in Earth typically contain less than 200 ppm H2O, such small quantities have tremendous influence on how easily they melt (i.e., the more water there is, the more magma is produced) and deform (the more water there is, the less viscous they are). These two properties alone emphasize that to understand the distribution of volcanism and the mechanism of plate tectonics, the water content of the mantle must be determined - Earth being a template to which all other terrestrial planets can be compared.

High flow ceramic pot filters.

PubMed

van Halem, D; van der Laan, H; Soppe, A I A; Heijman, S G J

2017-11-01

Ceramic pot filters are considered safe, robust and appropriate technologies, but there is a general consensus that water revenues are limited due to clogging of the ceramic element. The objective of this study was to investigate the potential of high flow ceramic pot filters to produce more water without sacrificing their microbial removal efficacy. High flow pot filters, produced by increasing the rice husk content, had a higher initial flow rate (6-19 L h -1 ), but initial LRVs for E. coli of high flow filters was slightly lower than for regular ceramic pot filters. This disadvantage was, however, only temporarily as the clogging in high flow filters had a positive effect on the LRV for E. coli (from below 1 to 2-3 after clogging). Therefore, it can be carefully concluded that regular ceramic pot filters perform better initially, but after clogging, the high flow filters have a higher flow rate as well as a higher LRV for E. coli. To improve the initial performance of new high flow filters, it is recommended to further utilize residence time of the water in the receptacle, since additional E. coli inactivation was observed during overnight storage. Although a relationship was observed between flow rate and LRV of MS2 bacteriophages, both regular and high flow filters were unable to reach over 2 LRV. Copyright © 2017 Elsevier Ltd. All rights reserved.

The use of filter media to determine filter cleanliness

NASA Astrophysics Data System (ADS)

Van Staden, S. J.; Haarhoff, J.

It is general believed that a sand filter starts its life with new, perfectly clean media, which becomes gradually clogged with each filtration cycle, eventually getting to a point where either head loss or filtrate quality starts to deteriorate. At this point the backwash cycle is initiated and, through the combined action of air and water, returns the media to its original perfectly clean state. Reality, however, dictates otherwise. Many treatment plants visited a decade or more after commissioning are found to have unacceptably dirty filter sand and backwash systems incapable of returning the filter media to a desired state of cleanliness. In some cases, these problems are common ones encountered in filtration plants but many reasons for media deterioration remain elusive, falling outside of these common problems. The South African conditions of highly eutrophic surface waters at high temperatures, however, exacerbate the problems with dirty filter media. Such conditions often lead to the formation of biofilm in the filter media, which is shown to inhibit the effective backwashing of sand and carbon filters. A systematic investigation into filter media cleanliness was therefore started in 2002, ending in 2005, at the University of Johannesburg (the then Rand Afrikaans University). This involved media from eight South African Water Treatment Plants, varying between sand and sand-anthracite combinations and raw water types from eutrophic through turbid to low-turbidity waters. Five states of cleanliness and four fractions of specific deposit were identified relating to in situ washing, column washing, cylinder inversion and acid-immersion techniques. These were measured and the results compared to acceptable limits for specific deposit, as determined in previous studies, though expressed in kg/m 3. These values were used to determine the state of the filters. In order to gain greater insight into the composition of the specific deposits stripped from the media, a

Effect of water-to-cement ratio and curing method on the strength, shrinkage and slump of the biosand filter concrete body.

PubMed

Chan, Nicole; Young-Rojanschi, Candice; Li, Simon

2018-03-01

The biosand filter is a household-level water treatment technology used globally in low-resource settings. As of December 2016, over 900,000 biosand filters had been implemented in 60 countries around the world. Local, decentralized production is one of the main advantages of this technology, but it also creates challenges, especially in regards to quality control. Using the current recommended proportions for the biosand filter concrete mix, slump was measured at water-to-cement ratios of 0.51, 0.64 and 0.76, with two replicates for each level. Twenty-eight-day strength was tested on four replicate cylinders, each at water-to-cement ratios of 0.51, 0.59, 0.67 and 0.76. Wet curing and dry curing were compared for 28-day strength and for their effect on shrinkage. Maximum strength occurred at water-to-cement ratios of 0.51-0.59, equivalent to 8-9.3 L water for a full-scale filter assuming saturated media, corresponding to a slump class of S1 (10-40 mm). Wet curing significantly improved strength of the concrete mix and reduced shrinkage. Quality control measures such as the slump test can significantly improve the quality within decentralized production of biosand filters, despite localized differences in production conditions.

Methane gas seepage - Disregard of significant water column filter processes?

NASA Astrophysics Data System (ADS)

Schneider von Deimling, Jens; Schmale, Oliver

2016-04-01

Marine methane seepage represents a potential contributor for greenhouse gas in the atmosphere and is discussed as a driver for climate change. The ultimate question is how much methane is released from the seafloor on a global scale and what fraction may reach the atmosphere? Dissolved fluxes from methane seepage sites on the seabed were found to be very efficiently reduced by benthic microbial oxidation, whereas transport of free gas bubbles from the seabed is considered to bypass the effective benthic methane filter. Numerical models are available today to predict the fate of such methane gas bubble release to the water column in regard to gas exchange with the ambient water column, respective bubble lifetime and rise height. However, the fate of rising gas bubbles and dissolved methane in the water column is not only governed by dissolution, but is also affected by lateral oceanographic currents and vertical bubble-induced upwelling, microbial oxidation, and physico-chemical processes that remain poorly understood so far. According to this gap of knowledge we present data from two study sites - the anthropogenic North Sea 22/4b Blowout and the natural Coal Oil point seeps - to shed light into two new processes gathered with hydro-acoustic multibeam water column imaging and microbial investigations. The newly discovered processes are hereafter termed Spiral Vortex and Bubble Transport Mechanism. Spiral Vortex describes the evolution of a complex vortical fluid motion of a bubble plume in the wake of an intense gas release site (Blowout, North Sea). It appears very likely that it dramatically changes the dissolution kinetics of the seep gas bubbles. Bubble Transport Mechanism prescribes the transport of sediment-hosted bacteria into the water column via rising gas bubbles. Both processes act as filter mechanisms in regard to vertical transport of seep related methane, but have not been considered before. Spiral Vortex and Bubble Transport Mechanism represent the

A highly efficient, stable, durable, and recyclable filter fabricated by femtosecond laser drilling of a titanium foil for oil-water separation.

PubMed

Ye, Sen; Cao, Qiang; Wang, Qingsong; Wang, Tianyuan; Peng, Qing

2016-11-21

It has been a long standing challenge to efficiently separate oil and water since prehistoric times, and now it has become even more desirable in oily wastewater purification and oil spill cleanup. Here we introduce a super oil-water separation filter with superhydrophilicity and underwater superoleophobicity, fabricated using femtosecond laser micro-hole drilling of a titanium foil. Such a simply-made filter, without any modification, can achieve a separation efficiency exceeding 99% in eight typical oil-water mixtures. It remains highly efficient after 40 cycles of recycling and after suffering erosion by corrosive media. Furthermore, the used filter, polluted with oil, could be recovered by ultraviolet illumination. The flux of filtered water is tunable by simply selecting the aperture of the microhole or the spacing between adjacent microholes. Such advanced functionality is due to roughness and the TiO 2 layers on the ablated surface during fabrication. With superhydrophilic and superoleophobic surfaces, this oil-water filer is also suitable for applications in anti-fouling, anti-smudge, anti-fog, and self-cleaning.

A highly efficient, stable, durable, and recyclable filter fabricated by femtosecond laser drilling of a titanium foil for oil-water separation

PubMed Central

Ye, Sen; Cao, Qiang; Wang, Qingsong; Wang, Tianyuan; Peng, Qing

2016-01-01

It has been a long standing challenge to efficiently separate oil and water since prehistoric times, and now it has become even more desirable in oily wastewater purification and oil spill cleanup. Here we introduce a super oil–water separation filter with superhydrophilicity and underwater superoleophobicity, fabricated using femtosecond laser micro-hole drilling of a titanium foil. Such a simply-made filter, without any modification, can achieve a separation efficiency exceeding 99% in eight typical oil–water mixtures. It remains highly efficient after 40 cycles of recycling and after suffering erosion by corrosive media. Furthermore, the used filter, polluted with oil, could be recovered by ultraviolet illumination. The flux of filtered water is tunable by simply selecting the aperture of the microhole or the spacing between adjacent microholes. Such advanced functionality is due to roughness and the TiO2 layers on the ablated surface during fabrication. With superhydrophilic and superoleophobic surfaces, this oil-water filer is also suitable for applications in anti-fouling, anti-smudge, anti-fog, and self-cleaning. PMID:27869194

Simultaneous concentration of bovine viruses and agricultural zoonotic bacteria from water using sodocalcic glass wool filters

USDA-ARS?s Scientific Manuscript database

Infiltration and runoff from manured agricultural fields can result in livestock pathogens reaching groundwater and surface waters. Here, we measured the effectiveness of glass wool filters to simultaneously concentrate enteric viruses and bacteria of bovine origin from water. The recovery efficienc...

Earth - South America First Frame of Earth Spin Movie

NASA Image and Video Library

1996-01-29

This color image of the Earth was obtained by NASA's Galileo at about 6:10 a.m. Pacific Standard Time on Dec. 11, 1990, when the spacecraft was about 1.3 million miles from the planet during the first of two Earth flybys on its way to Jupiter. The color composite used images taken through the red, green and violet filters. South America is near the center of the picture, and the white, sunlit continent of Antarctica is below. Picturesque weather fronts are visible in the South Atlantic, lower right. This is the first frame of the Galileo Earth spin movie, a 500- frame time-lapse motion picture showing a 25-hour period of Earth's rotation and atmospheric dynamics. A movie is availalble at http://photojournal.jpl.nasa.gov/catalog/PIA00114

[Evaluation of drinking-water treatment by Lifestraw® and Ceramic-pot filters].

PubMed

Pérez-Vidal, Andrea; Díaz-Gómez, Jaime; Salamanca-Rojas, Karen L; Rojas-Torres, Leidy Y

2016-04-01

Objective To evaluate under laboratory conditions, the removal efficiency of turbidity and E. coli of two household water filters: LifeStraw® family (MF) and ceramic pot filter (CPF). Methods The two systems were operated over 6 months using two identical control units per system, treating 7.5 L/d of a synthetic substrate used as raw water. The turbidity of the substrate was adjusted with Kaolinite and the E. coli concentration, with a replica of the ATCC 95922 strain. The differences of effluent quality of the systems, in terms of turbidity and E. coli, were evaluated with Analysis of Variance (ANOVA). Operative and maintenance aspects, that could limit or enhance the use of the systems, were also considered in the evaluation. Results The water synthetic substrate quality had an average of 32.2 ± 2.8 NTU for turbidity and 3,9x105 UFC/100 mL for E. coli. Both systems reduce the turbidity to values below 2 NTU with an inactivation of 100 % of E. coli. Statistical differences were found between the systems in terms of turbidity removal, MF being more efficient than the CPF (99,2 ± 0.4 % and 97.6 % ± 1.14, respectively). Conclusions Both systems are suitable for household water supply treatment, acheiving the water quality standards established by Colombian regulations. The MF was more efficient for suspended solids removal and filtration rate, but when economic, operative, and maintenance aspects along with social acceptability and lifespan are considered, the CPF seems more suitable, especially in rural areas.

Removal of microcystin-LR from spiked water using either activated carbon or anthracite as filter material.

PubMed

Drogui, Patrick; Daghrir, Rimeh; Simard, Marie-Christine; Sauvageau, Christine; Blais, Jean François

2012-01-01

The occurrence of cyanobacterial toxins (blue-green algae) in drinking water sources is a big concern for human health. Removal of microcystin-LR (MC-LR) from drinking water was evaluated at the laboratory pilot scale using either granular activated carbon (GAC) or powdered activated carbon (PAC) and compared with the treatment using anthracite as filter material. Virgin GAC was more effective at removing MC-LR (initial concentration ranging from 9 to 47 microg L(-1)) to reach the World Health Organization recommended level (1.0 microg L(-1)). When the GAC filter was colonized by bacteria, the filter became less effective at removing MC-LR owing to competitive reactions occurring between protein adsorption (released by bacteria) and MC-LR adsorption. Using PAC, the concentration of MC-LR decreased from 22 to 3 microg L(-1) (removal of 86% of MC-LR) by the addition of 100 mg PAC L(-1).

Application of design for six sigma methodology on portable water filter that uses membrane filtration system: A preliminary study

NASA Astrophysics Data System (ADS)

Fahrul Hassan, Mohd; Jusoh, Suhada; Zaini Yunos, Muhamad; Arifin, A. M. T.; Ismail, A. E.; Rasidi Ibrahim, M.; Zulafif Rahim, M.

2017-09-01

Portable water filter has grown significantly in recent years. The use of water bottles as a water drink stuff using hand pump water filtration unit has been suggested to replace water bottled during outdoor recreational activities and for emergency supplies. However, quality of water still the issue related to contaminated water due to the residual waste plants, bacteria, and so on. Based on these issues, the study was carried out to design a portable water filter that uses membrane filtration system by applying Design for Six Sigma. Design for Six Sigma methodology consists of five stages which is Define, Measure, Analyze, Design and Verify. There were several tools have been used in each stage in order to come out with a specific objective. In the Define stage, questionnaire approach was used to identify the needs of portable water filter in the future from potential users. Next, Quality Function Deployment (QFD) tool was used in the Measure stage to measure the users’ needs into engineering characteristics. Based on the information in the Measure stage, morphological chart and weighted decision matrix tools were used in the Analyze stage. This stage performed several activities including concept generation and selection. Once the selection of the final concept completed, detail drawing was made in the Design stage. Then, prototype was developed in the Verify stage to conduct proof-of-concept testing. The results that obtained from each stage have been reported in this paper. From this study, it can be concluded that the application of Design for Six Sigma in designing a future portable water filter that uses membrane filtration system is a good start in looking for a new alternative concept with a completed supporting document.

Earth observation based assessment of the water production and water consumption of Nile Basin agro-ecosystems

USGS Publications Warehouse

Bastiaanssen, Wim G.M.; Karimi, Poolad; Rebelo, Lisa-Maria; Duan, Zheng; Senay, Gabriel; Muthuwatte, Lal; Smakhtin, Vladimir

2014-01-01

The increasing competition for water resources requires a better understanding of flows, fluxes, stocks, and the services and benefits related to water consumption. This paper explains how public domain Earth Observation data based on Moderate Resolution Imaging Spectroradiometer (MODIS), Second Generation Meteosat (MSG), Tropical Rainfall Measurement Mission (TRMM) and various altimeter measurements can be used to estimate net water production (rainfall (P) > evapotranspiration (ET)) and net water consumption (ET > P) of Nile Basin agro-ecosystems. Rainfall data from TRMM and the Famine Early Warning System Network (FEWS-NET) RainFall Estimates (RFE) products were used in conjunction with actual evapotranspiration from the Operational Simplified Surface Energy Balance (SSEBop) and ETLook models. Water flows laterally between net water production and net water consumption areas as a result of runoff and withdrawals. This lateral flow between the 15 sub-basins of the Nile was estimated, and partitioned into stream flow and non-stream flow using the discharge data. A series of essential water metrics necessary for successful integrated water management are explained and computed. Net water withdrawal estimates (natural and humanly instigated) were assumed to be the difference between net rainfall (Pnet) and actual evapotranspiration (ET) and some first estimates of withdrawals—without flow meters—are provided. Groundwater-dependent ecosystems withdraw large volumes of groundwater, which exceed water withdrawals for the irrigation sector. There is a strong need for the development of more open-access Earth Observation databases, especially for information related to actual ET. The fluxes, flows and storage changes presented form the basis for a global framework to describe monthly and annual water accounts in ungauged river basins.

Volatile elements - water, carbon, nitrogen, noble gases - on Earth

NASA Astrophysics Data System (ADS)

Marty, B.

2017-12-01

Understanding the origin and evolution of life-bearing volatile elements (water, carbon, nitrogen) on Earth is a fruitful and debated area of research. In his pioneering work, W.W. Rubey inferred that the terrestrial atmosphere and the oceans formed from degassing of the mantle through geological periods of time. Early works on noble gas isotopes were consistent with this view and proposed a catastrophic event of mantle degassing early in Earth's history. We now have evidence, mainly from noble gas isotopes, that several cosmochemical sources contributed water and other volatiles at different stages of Earth's accretion. Potential contributors include the protosolar nebula gas that equilibrated with magma oceans, inner solar system bodies now represented by chondrites, and comets. Stable isotope ratios suggest volatiles where primarily sourced by planetary bodies from the inner solar system. However, recent measurements by the European Space Agency Rosetta probe on the coma of Comet 67P/Churyumov-Gerasimenko permit to set quantitative constraints on the cometary contribution to the surface of our planet. The surface and mantle reservoirs volatile elements exchanged volatile elements through time, with rates that are still uncertain. Some mantle regions remained isolated from whole mantle convection within the first tens to hundreds million years after start of solar system formation. These regions, now sampled by some mantle plumes (e.g., Iceland, Eifel) preserved their volatile load, as indicated by extinct and extant radioactivity systems. The abundance of volatile elements in the mantle is still not well known. Different approaches, such as high pressure experimental petrology, noble gas geochemistry, modelling, resulted in somewhat contrasted estimates, varying over one order of magnitude for water. Comparative planetology, that is, the study of volatiles on the Moon, Venus, Mars, Vesta, will shed light on the sources and strengths of these elements in the

Oxygen isotopic evidence for accretion of Earth's water before a high-energy Moon-forming giant impact.

PubMed

Greenwood, Richard C; Barrat, Jean-Alix; Miller, Martin F; Anand, Mahesh; Dauphas, Nicolas; Franchi, Ian A; Sillard, Patrick; Starkey, Natalie A

2018-03-01

The Earth-Moon system likely formed as a result of a collision between two large planetary objects. Debate about their relative masses, the impact energy involved, and the extent of isotopic homogenization continues. We present the results of a high-precision oxygen isotope study of an extensive suite of lunar and terrestrial samples. We demonstrate that lunar rocks and terrestrial basalts show a 3 to 4 ppm (parts per million), statistically resolvable, difference in Δ 17 O. Taking aubrite meteorites as a candidate impactor material, we show that the giant impact scenario involved nearly complete mixing between the target and impactor. Alternatively, the degree of similarity between the Δ 17 O values of the impactor and the proto-Earth must have been significantly closer than that between Earth and aubrites. If the Earth-Moon system evolved from an initially highly vaporized and isotopically homogenized state, as indicated by recent dynamical models, then the terrestrial basalt-lunar oxygen isotope difference detected by our study may be a reflection of post-giant impact additions to Earth. On the basis of this assumption, our data indicate that post-giant impact additions to Earth could have contributed between 5 and 30% of Earth's water, depending on global water estimates. Consequently, our data indicate that the bulk of Earth's water was accreted before the giant impact and not later, as often proposed.

The divergent fates of primitive hydrospheric water on Earth and Mars.

PubMed

Wade, Jon; Dyck, Brendan; Palin, Richard M; Moore, James D P; Smye, Andrew J

2017-12-20

Despite active transport into Earth's mantle, water has been present on our planet's surface for most of geological time. Yet water disappeared from the Martian surface soon after its formation. Although some of the water on Mars was lost to space via photolysis following the collapse of the planet's magnetic field, the widespread serpentinization of Martian crust suggests that metamorphic hydration reactions played a critical part in the sequestration of the crust. Here we quantify the relative volumes of water that could be removed from each planet's surface via the burial and metamorphism of hydrated mafic crusts, and calculate mineral transition-induced bulk-density changes at conditions of elevated pressure and temperature for each. The metamorphic mineral assemblages in relatively FeO-rich Martian lavas can hold about 25 per cent more structurally bound water than those in metamorphosed terrestrial basalts, and can retain it at greater depths within Mars. Our calculations suggest that in excess of 9 per cent by volume of the Martian mantle may contain hydrous mineral species as a consequence of surface reactions, compared to about 4 per cent by volume of Earth's mantle. Furthermore, neither primitive nor evolved hydrated Martian crust show noticeably different bulk densities compared to their anhydrous equivalents, in contrast to hydrous mafic terrestrial crust, which transforms to denser eclogite upon dehydration. This would have allowed efficient overplating and burial of early Martian crust in a stagnant-lid tectonic regime, in which the lithosphere comprised a single tectonic plate, with only the warmer, lower crust involved in mantle convection. This provided an important sink for hydrospheric water and a mechanism for oxidizing the Martian mantle. Conversely, relatively buoyant mafic crust and hotter geothermal gradients on Earth reduced the potential for upper-mantle hydration early in its geological history, leading to water being retained close to

Drawer compacted sand filter: a new and innovative method for on-site grey water treatment.

PubMed

Assayed, Almoayied; Chenoweth, Jonathan; Pedley, Steven

2014-01-01

In this paper, results ofa new sand filter design were presented. The drawer compacted sand filter (DCSF) is a modified design for a sand filter in which the sand layer is broken down into several layers, each of which is 10 cm high and placed in a movable drawer separated by a 10 cm space. A lab-scale DCSF was designed and operated for 330 days fed by synthetic grey water. The response of drawer sand filters to variable hydraulic and organic loading rates (HLR and OLR) in terms of biological oxygen demand (BODs), chemical oxygen demand (COD), total suspended solids (TSS), pH, electrical conductivity and Escherichia coli reductions were evaluated. The HLR was studied by increasing from 72 to 142 L m(-2) day(-1) and OLR was studied by increasing it from 23 to 30 g BOD5 m(-2) day(-1) while keeping the HLR constant at 142 L m(-2) day(-1). Each loading regime was applied for 110 days. Results showed that DCSF was able to remove >90% of organic matter and total suspended solids for all doses. No significant difference was noticed in terms of overall filter efficiency between different loads for all parameters. Significant reduction in BOD5 and COD (P < .05) was noticed after water was drained through the third drawer in all tested loads. The paper concludes that DCSF would be appropriate for use in dense urban areas as its footprint is small and is appropriate for a wide range of users because of its convenience and low maintenance requirements.

Benzophenone-type UV filters in surface waters: An assessment of profiles and ecological risks in Shanghai, China.

PubMed

Wu, Ming-Hong; Xie, Deng-Guo; Xu, Gang; Sun, Rui; Xia, Xiao-Yu; Liu, Wen-Long; Tang, Liang

2017-07-01

Benzophenone-type UV filters (BP-UV filters) are frequently introduced into aquatic environment from several sources. The occurrence and fate of select BP-UV filters and their metabolites were investigated in this study. All target compounds were detected in water samples, except for 2, 3, 4-trihydroxybenzophenone (2, 3, 4-OH-BP). The concentration reached up 131ngL -1 for 5-benzoyl-4-hydroxy-2-ethoxybenzenesulfonic acid (BP-4), 30.0ngL -1 for 2-hydroxy-4-methoxybenzophenone (BP-3), and mean value of 158ngL -1 for benzophenone (BP). Concentrations of BP-UV filters were not related to recreational waters but with high population frequencies. In addition, five BP-UV filters, namely 2,2',4,4'-tetrahydroxybenzophenone (BP-2), 2,3,4-OH-BP, 2,4-dihydroxybenzophenone (BP-1), 4-hydroxybenzophenone (4-OH-BP) and BP were investigated for probable sources, and found that they originate from BP-3 metabolism. There is a similar source for BP-3, BP-4, BP-1, 4-OH-BP and BP. Environmental risk assessment (ERA) showed that risk quotients (RQs) of BP-4, BP-3 and BP were 2.7, 0.8 and 0.5, respectively. Copyright © 2017 Elsevier Inc. All rights reserved.

Modeling Adsorption Based Filters (Bio-remediation of Heavy Metal Contaminated Water)

NASA Astrophysics Data System (ADS)

McCarthy, Chris

I will discuss kinetic models of adsorption, as well as models of filters based on those mechanisms. These mathematical models have been developed in support of our interdisciplinary lab group, which is centered at BMCC/CUNY (City University of New York). Our group conducts research into bio-remediation of heavy metal contaminated water via filtration. The filters are constructed out of biomass, such as spent tea leaves. The spent tea leaves are available in large quantities as a result of the industrial production of tea beverages. The heavy metals bond with the surfaces of the tea leaves (adsorption). The models involve differential equations, stochastic methods, and recursive functions. I will compare the models' predictions to data obtained from computer simulations and experimentally by our lab group. Funding: CUNY Collaborative Incentive Research Grant (Round 12); CUNY Research Scholars Program.

[Determination of five representative ultraviolet filters in water by gas chromatography-mass spectrometry].

PubMed

Ding, Yiran; Huang, Yun; Zhao, Tingting; Cai, Qian; Luo, Yu; Huang, Bin; Zhang, Yuxia; Pan, Xuejun

2014-06-01

A method for the determination of five representative organic UV filters: ethylhexyl methoxycinnamate (EHMC), benzophenone-3 (BP-3), 4-methylbenzylidene camphor (4-MBC), octocrylene (OC), homosalate (HMS) in water was investigated. The method was ased on derivatization, solid phase extraction (SPE), followed by determination with gas chromatography-mass spectrometry (GC-MS). The variables involved in the derivatization of BP-3 and HMS were optimized, and SPE conditions were studied. For derivatization, 100 microL N,O-bis(trimethylsilyl) trifluoroacetamide (BSTFA) was used as derivatization reagent and reacted with BP-3 and HMS at 100 degrees C for 100 min. For SPE, the pH value of water sample was adjusted to 3-5. The Oasis HLB cartridges were employed and the solution of ethyl acetate and dichloromethane (1 : 1, v/v) was used as the eluting solvent, and good recoveries of the target compounds were obtained. The limits of detection (LODs) and the limits of quantification (LOQs) for the five target compounds in water samples were 0.5-1.2 ng/L and 1.4-4.0 ng/L, respectively. The recoveries of spiked water samples were 87.85%-102.34% with good repeatability and reproducibility (RSD < 5%, n = 3) for all the target compounds. Finally, the validated method was applied to analysis the representative UV filters in water samples collected from a wastewater treatment plant in Kunming city of Yunnan province.

Sorption and degradation of selected organic UV filters (BM-DBM, 4-MBC, and OD-PABA) in laboratory water-sediment systems.

PubMed

Li, Sheng; Lu, Guanghua; Xie, Zhengxin; Ding, Jiannan; Liu, Jianchao; Li, Yi

2016-05-01

Organic UV filters that have been widely used in sunscreens and other personal care products have drawn much public concern because of their widespread contamination in the environment and their potential ecological risks to ecosystems. We selected three UV filters with high frequency of detection in the environment, namely butyl methoxy dibenzoylmethane (BM-DBM), ethylhexyl dimethyl p-aminobenzoate (OD-PABA), and 4-methylbenzylidene camphor (4-MBC), to investigate the sorption and degradation behaviors of these compounds in lab-scale water-sediment systems set up with natural water and sediment samples collected from different rivers and lakes (i.e., Yangtze River, Qinhuai River, Xuanwu Lake, and Mochou Lake) in Nanjing, East China. The sorption isotherms of these UV filters were well described by the Freundlich equation (C s   = K f  × C w (n) ). The sorption of three UV filters in four sediments was all linear or close to it, with n values between 0.92 and 1.13. A moderate to strong sorption affinity was observed for these compounds, and the sorption appears to be irreversible. For the combined sorption and degradation studies, sorption was found to be a primary mechanism for the disappearance of these UV filters from the water phase, and biotransformation appears to be the predominant factor for the degradation of the target compounds in the water-sediment systems. All three UV filters were found to be slightly resistant to the microbes in these systems, with DT50total and DT90total values-the disappearance time (DT) describes the time in which the initial total mass of the UV filters in the whole system is reduced by 50 and 90 %-ranging between 18 and 31 days and 68 and 101 days, respectively.

Glass cylindrical filter for electrolysis cell

NASA Astrophysics Data System (ADS)

Abe, Shinichi; Akiyama, Fuminori

1992-09-01

Some electrolysis requires separation of electrolytic solution by a filter between two electrodes in order to prevent products from reacting secondarily at another electrode. These filters are usually made of a glass filter or ion exchanger membrane, and they are fixed at the electrolysis cell or cover one electrode. This report presents a detachable glass cylindrical filter for electrolytic reaction. The glass cylindrical filter was made from glass filter powder placed in a mold and heated at 800 C for 18 minutes. Using this filter, electrolytic reduction of carbon dioxide was performed in 0 C hot water with benzoin. This reaction produces aqueous oil from carbon dioxide and water. The products were compared with and without the filter and, although the yield did not differ between the two reaction systems, products without the filter contained highly polymerized oil compared to those with the filter. This suggests that the aqueous oil was produced at the cathode and polymerized at the anode.

Heat for wounds - water-filtered infrared-A (wIRA) for wound healing - a review.

PubMed

Hoffmann, Gerd; Hartel, Mark; Mercer, James B

2016-01-01

Water-filtered infrared-A (wIRA) is a special form of heat radiation with high tissue penetration and a low thermal load to the skin surface. wIRA corresponds to the major part of the sun's heat radiation, which reaches the surface of the Earth in moderate climatic zones filtered by water and water vapour of the atmosphere. wIRA promotes healing of acute and chronic wounds both by thermal and thermic as well as by non-thermal and non-thermic cellular effects. This publication includes a literature review with search in PubMed/Medline for "water-filtered infrared-A" and "wound"/"ulcus" or "wassergefiltertes Infrarot A" and "Wunde"/"Ulkus", respectively (publications in English and German), and additional analysis of study data. Seven prospective clinical studies (of these six randomized controlled trials (RCT), the largest study with n=400 patients) were identified and included. All randomized controlled clinical trials compare a combination of high standard care plus wIRA treatment vs. high standard care alone. The results below marked with "vs." present these comparisons. wIRA increases tissue temperature (+2.7°C at a tissue depth of 2 cm), tissue oxygen partial pressure (+32% at a tissue depth of 2 cm) and tissue perfusion (effect sizes within the wIRA group). wIRA promotes normal as well as disturbed wound healing by diminishing inflammation and exudation, by promotion of infection defense and regeneration, and by alleviation of pain (with respect to alleviation of pain, without any exception during 230 irradiations, 13.4 vs. 0.0 on a visual analogue scale (VAS 0-100), median difference between groups 13.8, 95% confidence interval (CI) 12.3/16.7, p<0.000001) with a substantially reduced need for analgesics (52-69% less in the three groups with wIRA compared to the three control groups in visceral surgery, p=0.000020 and 0.00037 and 0.0045, respectively; total of 6 vs. 14.5 analgesic tablets on 6 surveyed days (of weeks 1-6) in chronic venous stasis ulcers

Sphagnum can 'filter' N deposition, but effects on the plant and pore water depend on the N form.

PubMed

Chiwa, Masaaki; Sheppard, Lucy J; Leith, Ian D; Leeson, Sarah R; Tang, Y Sim; Cape, J Neil

2016-07-15

The ability of Sphagnum moss to efficiently intercept atmospheric nitrogen (N) has been assumed to be vulnerable to increased N deposition. However, the proposed critical load (20kgNha(-1)yr(-1)) to exceed the capacity of the Sphagnum N filter has not been confirmed. A long-term (11years) and realistic N manipulation on Whim bog was used to study the N filter function of Sphagnum (Sphagnum capillifolium) in response to increased wet N deposition. On this ombrotrophic peatland where ambient deposition was 8kgNha(-1)yr(-1), an additional 8, 24, and 56kgNha(-1)yr(-1) of either ammonium (NH4(+)) or nitrate (NO3(-)) has been applied for 11years. Nutrient status of Sphagnum and pore water quality from the Sphagnum layer were assessed. The N filter function of Sphagnum was still active up to 32kgNha(-1)yr(-1) even after 11years. N saturation of Sphagnum and subsequent increases in dissolved inorganic N (DIN) concentration in pore water occurred only for 56kgNha(-1)yr(-1) of NH4(+) addition. These results indicate that the Sphagnum N filter is more resilient to wet N deposition than previously inferred. However, functionality will be more compromised when NH4(+) dominates wet deposition for high inputs (56kgNha(-1)yr(-1)). The N filter function in response to NO3(-) uptake increased the concentration of dissolved organic N (DON) and associated organic anions in pore water. NH4(+) uptake increased the concentration of base cations and hydrogen ions in pore water though ion exchange. The resilience of the Sphagnum N filter can explain the reported small magnitude of species change in the Whim bog ecosystem exposed to wet N deposition. However, changes in the leaching substances, arising from the assimilation of NO3(-) and NH4(+), may lead to species change. Copyright © 2016 Elsevier B.V. All rights reserved.

Extremophiles in Household Water Heaters

NASA Astrophysics Data System (ADS)

Wilpiszeski, R.; House, C. H.

2016-12-01

A significant fraction of Earth's microbial diversity comes from species living in extreme environments, but natural extreme environments can be difficult to access. Manmade systems like household water heaters serve as an effective proxy for thermophilic environments that are otherwise difficult to sample directly. As such, we are investigating the biogeography, taxonomic distribution, and evolution of thermophiles growing in domestic water heaters. Citizen scientists collected hot tap water culture- and filter- samples from 101 homes across the United States. We recovered a single species of thermophilic heterotroph from culture samples inoculated from water heaters across the United States, Thermus scotoductus. Whole-genome sequencing was conducted to better understand the distribution and evolution of this single species. We have also sequenced hyper-variable regions of the 16S rRNA gene from whole-community filter samples to identify the broad diversity and distribution of microbial cells captured from each water heater. These results shed light on the processes that shape thermophilic populations and genomes at a spatial resolution that is difficult to access in naturally occurring extreme ecosystems.

Integrated Metagenomic and Physiochemical Analyses to Evaluate the Potential Role of Microbes in the Sand Filter of a Drinking Water Treatment System

PubMed Central

Bai, Yaohui; Liu, Ruiping; Liang, Jinsong; Qu, Jiuhui

2013-01-01

While sand filters are widely used to treat drinking water, the role of sand filter associated microorganisms in water purification has not been extensively studied. In the current investigation, we integrated molecular (based on metagenomic) and physicochemical analyses to elucidate microbial community composition and function in a common sand filter used to treat groundwater for potable consumption. The results revealed that the biofilm developed rapidly within 2 days (reaching ∼1011 prokaryotes per gram) in the sand filter along with abiotic and biotic particulates accumulated in the interstitial spaces. Bacteria (up to 90%) dominated the biofilm microbial community, with Alphaproteobacteria being the most common class. Thaumarchaeota was the sole phylum of Archaea, which might be involved in ammonia oxidation. Function annotation of metagenomic datasets revealed a number of aromatic degradation pathway genes, such as aromatic oxygenase and dehydrogenase genes, in the biofilm, suggesting a significant role for microbes in the breakdown of aromatic compounds in groundwater. Simultaneous nitrification and denitrification pathways were confirmed as the primary routes of nitrogen removal. Dissolved heavy metals in groundwater, e.g. Mn2+ and As3+, might be biologically oxidized to insoluble or easily adsorbed compounds and deposited in the sand filter. Our study demonstrated that the role of the microbial community in the sand filter treatment system are critical to effective water purification in drinking water. PMID:23593378

Integrated metagenomic and physiochemical analyses to evaluate the potential role of microbes in the sand filter of a drinking water treatment system.

PubMed

Bai, Yaohui; Liu, Ruiping; Liang, Jinsong; Qu, Jiuhui

2013-01-01

While sand filters are widely used to treat drinking water, the role of sand filter associated microorganisms in water purification has not been extensively studied. In the current investigation, we integrated molecular (based on metagenomic) and physicochemical analyses to elucidate microbial community composition and function in a common sand filter used to treat groundwater for potable consumption. The results revealed that the biofilm developed rapidly within 2 days (reaching ≈ 10(11) prokaryotes per gram) in the sand filter along with abiotic and biotic particulates accumulated in the interstitial spaces. Bacteria (up to 90%) dominated the biofilm microbial community, with Alphaproteobacteria being the most common class. Thaumarchaeota was the sole phylum of Archaea, which might be involved in ammonia oxidation. Function annotation of metagenomic datasets revealed a number of aromatic degradation pathway genes, such as aromatic oxygenase and dehydrogenase genes, in the biofilm, suggesting a significant role for microbes in the breakdown of aromatic compounds in groundwater. Simultaneous nitrification and denitrification pathways were confirmed as the primary routes of nitrogen removal. Dissolved heavy metals in groundwater, e.g. Mn(2+) and As(3+), might be biologically oxidized to insoluble or easily adsorbed compounds and deposited in the sand filter. Our study demonstrated that the role of the microbial community in the sand filter treatment system are critical to effective water purification in drinking water.

Biomethanation of Harmful Macroalgal Biomass in Leach-Bed Reactor Coupled to Anaerobic Filter: Effect of Water Regime and Filter Media

PubMed Central

Jung, Heejung; Kim, Jaai; Lee, Changsoo

2018-01-01

Ulva is a marine macroalgal genus which causes serious green tides in coastal areas worldwide. This study investigated anaerobic digestion as a way to manage Ulva waste in a leach-bed reactor coupled to an anaerobic filter (LBR-AF). Two LBR-AF systems with different filter media, blast furnace slag grains for R1, and polyvinyl chloride rings for R2, were run at increasing water replacement rates (WRRs). Both achieved efficient volatile solids reduction (68.4–87.1%) and methane yield (148–309 mL/g VS fed) at all WRRs, with the optimal WRR for maximum methane production being 100 mL/d. R1 maintained more stable methanation performance than R2, possibly due to the different surface properties (i.e., biomass retention capacity) of the filter media. Such an effect was also noted in the different behaviors of the LBR and AF between R1 and R2. The molecular analysis results revealed that the development of the microbial community structure in the reactors was primarily determined by the fermentation type, i.e., dry (LBR) or wet (AF). PMID:29701670

Removal of atrazine and four organophosphorus pesticides from environmental waters by diatomaceous earth-remediation method.

PubMed

Agdi, K; Bouaid, A; Esteban, A M; Hernando, P F; Azmani, A; Camara, C

2000-10-01

A new viable remediation technique based on the use of diatomaceous earth is proposed to improve the ecological system. Its ability to remove atrazine and the four organophosphorus pesticides parathion-methyl, chlorpyriphos, fenamiphos and methidathion from river and waste waters has been proven. A series of experiments including variable conditions, such as temperature, pH, contact time, pesticide concentration and adsorbent quantity, were performed to demonstrate the efficiency of pesticide removal from three different water samples. The batch experiments showed that diatomaceous earth was able to remove 95% of chlorpyriphos, 75% of methidathion and parathion-methyl and 55% of atrazine and fenamiphos from all types of waters tested. The individual adsorption of each pesticide on diatomaceous earth could be described by the Freundlich isotherm and a tentative adsorption mechanism was proposed. The Freundlich coefficient (Kf) and Freundlich constant (1/n) appeared to be closely related to the physicochemical properties (Kow, solubility) of the compounds. The actual results support the conclusion that diatomaceous earth has the potential to serve as an extractant in remediation techniques.

Ensemble kalman filtering to perform data assimilation with soil water content probes and pedotransfer functions in modeling water flow in variably saturated soils

USDA-ARS?s Scientific Manuscript database

Data from modern soil water contents probes can be used for data assimilation in soil water flow modeling, i.e. continual correction of the flow model performance based on observations. The ensemble Kalman filter appears to be an appropriate method for that. The method requires estimates of the unce...

The Nano-filters as the tools for the management of the water imbalance in the human society

NASA Astrophysics Data System (ADS)

Singh, R. P.; Kontar, V.

2011-12-01

ultra-thin nanoscale fibers, which filter out contaminants, plus active carbon granules, which kill bacteria. The carbon nano-tube as filters exhibit chemical-species selectivity with higher physical strength and higher temperature tolerance, more rugged process, more rapid filtration, regeneration via thermal means rather than physical removal and lowers costs. The nano-filters remove the toxic or unwanted bivalent ions (ions with 2 or more charges), such as lead, iron, nickel, mercury, etc. The nano-materials and nano-filters will help solve the problems of the water imbalance management in the human society. Therefore we are talking about some nano-applications on the session H138 "Imbalance of Water in Nature".

Earth Science (A Process Approach), Section 1: The Water Cycle.

ERIC Educational Resources Information Center

Campbell, K. C.; And Others

Included is a collection of earth science laboratory activities, which may provide the junior or senior high school science teacher with ideas for activities in his program. The included 48 experiments are grouped into these areas: properties of matter; evaporation; atmospheric moisture and condensation; precipitation; moving water, subsurface…

Ammonium removal of drinking water at low temperature by activated carbon filter biologically enhanced with heterotrophic nitrifying bacteria.

PubMed

Qin, Wen; Li, Wei-Guang; Zhang, Duo-Ying; Huang, Xiao-Fei; Song, Yang

2016-03-01

We sought to confirm whether use of Acinetobacter strains Y7 and Y16, both strains of heterotrophic nitrifying bacteria, was practical for removing ammonium (NH4 (+)-N) from drinking water at low temperatures. To test this, ammonium-containing drinking water was treated with strains Y7 and Y16 at 8 and 2 °C. Continuous ammonium treatment was conducted in order to evaluate the performance of three biologically enhanced activated carbon (BEAC) filters in removing ammonium. The three BEAC filters were inoculated with strain Y7, strain Y16, and a mixture of strains Y7 and Y16, respectively. A granular activated carbon (GAC) filter, without inoculation by any strains, was tested in parallel with the BEAC filters as control. The results indicated that NH4 (+)-N removal was significant when a BEAC filter was inoculated with the mixture of strains Y7 and Y16 (BEAC-III filter). Amounts of 0.44 ± 0.05 and 0.25 ± 0.05 mg L(-1) NH4 (+)-N were removed using the BEAC-III filter at 8 and 2 °C, respectively. These values were 2.8-4.0-fold higher than the values of ammonium removal acquired using the GAC filter. The synergistic effect of using strains Y7 and Y16 in concert was the cause of the high-ammonium removal efficiency achieved by using the BEAC-III filter at low temperatures. In addition, a high C/N ratio may promote NH4 (+)-N removal efficiency by improving biomass and microbial activity. This study provides new insight into the use of biofilters to achieve biological removal of ammonium at low temperature.

Non-porous membrane-assisted liquid-liquid extraction of UV filter compounds from water samples.

PubMed

Rodil, Rosario; Schrader, Steffi; Moeder, Monika

2009-06-12

A method for the determination of nine UV filter compounds [benzophenone-3 (BP-3), isoamyl methoxycinnamate, 4-methylbenzylidene camphor, octocrylene (OC), butyl methoxydibenzoylmethane, ethylhexyl dimethyl p-aminobenzoate (OD-PABA), ethylhexyl methoxycinnamate (EHMC), ethylhexyl salicylate and homosalate] in water samples was developed and evaluated. The procedure includes non-porous membrane-assisted liquid-liquid extraction (MALLE) and LC-atmospheric pressure photoionization (APPI)-MS/MS. Membrane bags made of different polymeric materials were examined to enable a fast and simple extraction of the target analytes. Among the polymeric materials tested, low- and high-density polyethylene membranes proved to be well suited to adsorb the analytes from water samples. Finally, 2 cm length tailor-made membrane bags were prepared from low-density polyethylene in order to accommodate 100 microL of propanol. The fully optimised protocol provides recoveries from 76% to 101% and limits of detection (LOD) between 0.4 ng L(-1) (OD-PABA) and 16 ng L(-1) (EHMC). The interday repeatability of the whole protocol was below 18%. The effective separation of matrix molecules was proved by only marginal matrix influence during the APPI-MS analysis since no ion suppression effects were observed. During the extraction step, the influence of the matrix was only significant when non-treated wastewater was analysed. The analysis of lake water indicated the presence of seven UV filter compounds included in this study at concentrations between 40 ng L(-1) (BP-3) and 4381 ng L(-1) (OC). In non-treated wastewater several UV filters were also detected at concentration levels as high as 5322 ng L(-1) (OC).

A rapid two dot filter assay for the detection of E. coli O157 in water samples.

PubMed

Kamma, Sujatha; Tang, Lily; Leung, Kelvin; Ashton, Edie; Newman, Norman; Suresh, Mavanur R

2008-07-31

E. coli O157:H7 is an enterohemorrhagic bacteria that cause deadly water-borne infections implicated in outbreaks of a wide spectrum of human gastrointestinal diseases. It is therefore important to have a rapid convenient, simple and sensitive range of detection of E. coli O157:H7. A new E. coli O157 MAb designated P124 was developed for ultrasensitive detection of E. coli O157 in water, apple juice and beef for routine use. A prototype filter dot assay was designed with anti-E. coli O157 MAb bound to 0.2 microm nitrocellulose filter disk as the capture antibody. A 100 ml water sample spiked with 1-50 CFU of E. coli O157 either in the presence or absence of other non-specific bacteria were filtered for capture of the pathogen on the antibody coated nitrocellulose disk. The detection of the pathogen was successfully accomplished by the same antibody both as a capture and detecting antibody as a homosandwich. In a non-enriched format, detection of E. coli was possible with a sensitivity of 2500 CFU/100 ml. Ultrasensitive detection of ~1 CFU/100 ml sample could be achieved by a prior pathogen enrichment step before the addition of the labeled antibody. The design of this diagnostic test is based on the common architecture of all bacteria, viruses and spores, namely the manifestation of repeat lipopolysaccharide epitopes on the surface. We have developed an easy-to-use two dot visual filter assay for translation into current water testing in public health laboratories to detect E. coli O157:H7. In a 5 h assay approximately 1 CFU and approximately 5 CFU of E. coli O157 could be detected in 100 ml of water or juice and lake samples respectively. This simple homosandwich enrichment strategy can also be used to detect low levels of other water-borne pathogens.

Rare earth element analysis indicates micropollutants in an urban estuary

NASA Astrophysics Data System (ADS)

Mohajerin, T. J.; Johannesson, K. H.; Kolker, A.; Burdige, D. J.; Chevis, D.

2011-12-01

Rare earth element analysis of Bayou Bienvenue waters shows anomalously high gadolinium, Gd, concentrations relative to its nearest neighbors in the REE series, europium and terbium. The anomalously high Gd concentrations indicate anthropogenic input from waste-water treatment plants in the area as anthropogenic Gd input can be traced back to its use as a contrast agent in magnetic resonance imaging in hospitals. Others have shown that anomalously high levels of Gd in natural waters are likely to be associated with other micropollutants that also occur in hospital effluent and that are not removed in the wastewater treatment process, including pharmaceuticals in the form of steroids, antihistamines, and antibiotics. Estuaries serve as many important ecological roles and have been shown to act as a filter for pollutants. To better understand the transport, biogeochemical cycling, and ultimate fate of trace elements in estuaries, I collected surface water samples from Bayou Bienvenue, a wetland triangle that covers an area of 427 acres directly adjacent to New Orleans, Louisiana. Water samples from Bayou Bienvenue were collected along the salinity gradient and subsequently filtered through progressively smaller pore-size filters. The resulting fractions were analyzed for trace element concentions, including the REEs, by magnetic sector ICP-MS. The attached figure shows the Gd anomaly present in the particulate (>0.45μm) fraction. Upper continental crust (UCC)-normalized plots of colloidal REEs (0.02μm - 0.45μm) fraction is lacking this anomaly indicating anthropogenic Gd is found chiefly in the particulate fraction in Bayou Bienvenue. No clear relationship between Gd concentration and salinity was apparent.

Continental-scale water fluxes from continuous GPS observations of Earth surface loading

NASA Astrophysics Data System (ADS)

Borsa, A. A.; Agnew, D. C.; Cayan, D. R.

2015-12-01

After more than a decade of observing annual oscillations of Earth's surface from seasonal snow and water loading, continuous GPS is now being used to model time-varying terrestrial water fluxes on the local and regional scale. Although the largest signal is typically due to the seasonal hydrological cycle, GPS can also measure subtle surface deformation caused by sustained wet and dry periods, and to estimate the spatial distribution of the underlying terrestrial water storage changes. The next frontier is expanding this analysis to the continental scale and paving the way for incorporating GPS models into the National Climate Assessment and into the observational infrastructure for national water resource management. This will require reconciling GPS observations with predictions from hydrological models and with remote sensing observations from a suite of satellite instruments (e.g. GRACE, SMAP, SWOT). The elastic Earth response which transforms surface loads into vertical and horizontal displacements is also responsible for the contamination of loading observations by tectonic and anthropogenic transients, and we discuss these and other challenges to this new application of GPS.

Earth Control and Investigations: Training Course 1974.

ERIC Educational Resources Information Center

Department of the Interior, Denver, CO. Engineering and Research Center.

This document contains the outlines of each of 34 lectures given in the Earth Control and Investigations course sponsored by the Denver Laboratories. Topics covered include construction control of earth dams, canals, and filters; field and laboratory test procedures; soil classification and logging; and field investigations. (DT)

Estimation and filtering techniques for high-accuracy GPS applications

NASA Technical Reports Server (NTRS)

Lichten, S. M.

1989-01-01

Techniques for determination of very precise orbits for satellites of the Global Positioning System (GPS) are currently being studied and demonstrated. These techniques can be used to make cm-accurate measurements of station locations relative to the geocenter, monitor earth orientation over timescales of hours, and provide tropospheric and clock delay calibrations during observations made with deep space radio antennas at sites where the GPS receivers have been collocated. For high-earth orbiters, meter-level knowledge of position will be available from GPS, while at low altitudes, sub-decimeter accuracy will be possible. Estimation of satellite orbits and other parameters such as ground station positions is carried out with a multi-satellite batch sequential pseudo-epoch state process noise filter. Both square-root information filtering (SRIF) and UD-factorized covariance filtering formulations are implemented in the software.

Short-period variability in terrestrial water storage from GNSS observations of Earth surface deformation

NASA Astrophysics Data System (ADS)

Borsa, A. A.; Adusumilli, S.; Agnew, D. C.; Silverii, F.; Small, E. E.

2017-12-01

Modern geodetic observations of Earth surface deformation, initially targeted at processes such as tectonics and volcanism, also record the subtle signature of mass movements within Earth's atmosphere and hydrosphere. These observations, which track the elastic response of the solid earth to changing surface mass loads, are clearly evident in position time series from permanent Global Navigation Satellite System (GNSS) stations, which recent work has used to recover changes in terrestrial water storage (TWS) over seasonal and multi-annual time scales. Earth's elastic reponse is nearly instantaneous, which suggests the possibility of observing TWS changes at much shorter periods, limited only by the 24 hour resolution of standard GNSS data products and noise in the GNSS position estimates. We present results showing that TWS increases from individual storms can be recovered using the GNSS network in the United States, and that the water mass changes are similar to gridded precipitation estimates from the National Centers for Environmental Prediction (NCEP). The gradual decline we observe in TWS following each storm is diagnostic of runoff and local evapotranspiration, and varies by location. By greatly increasing the temporal resolution of GNSS-derived estimates of TWS, we hope to provide constraints on integrated water fluxes from hydrological models on all relevant timescales.

Optimum constrained image restoration filters

NASA Technical Reports Server (NTRS)

Riemer, T. E.; Mcgillem, C. D.

1974-01-01

The filter was developed in Hilbert space by minimizing the radius of gyration of the overall or composite system point-spread function subject to constraints on the radius of gyration of the restoration filter point-spread function, the total noise power in the restored image, and the shape of the composite system frequency spectrum. An iterative technique is introduced which alters the shape of the optimum composite system point-spread function, producing a suboptimal restoration filter which suppresses undesirable secondary oscillations. Finally this technique is applied to multispectral scanner data obtained from the Earth Resources Technology Satellite to provide resolution enhancement. An experimental approach to the problems involving estimation of the effective scanner aperture and matching the ERTS data to available restoration functions is presented.

Noble Gases Trace Earth's Subducted Water Flux

NASA Astrophysics Data System (ADS)

Smye, A.; Jackson, C.; Konrad-Schmolke, M.; Parman, S. W.; Ballentine, C. J.

2016-12-01

Volatile elements are transported from Earth's surface reservoirs back into the mantle during subduction of oceanic lithosphere [e.g. 1]. Here, we investigate the degree to which the fate of slab-bound noble gases and water are linked through the subduction process. Both water and noble gases are soluble in ring-structured minerals, such as amphibole, that are common constituents of subducted oceanic lithosphere. Heating and burial during subduction liberates noble gases and water from minerals through a combination of diffusion and dissolution. Combining a kinetic model, parameterized for noble gas fractionation in amphibole [2], with thermodynamic phase equilibria calculations, we quantify the effect of subduction dehydration on the elemental composition of slab-bound noble gases. Results show that post-arc slab water and noble gas fluxes are highly correlated. Hot subduction zones, which likely dominate over geologic history, efficiently remove noble gases and water from the down-going slab; furthermore, kinetic fractionation of noble gases is predicted to occur beneath the forearc. Conversely, hydrated portions of slab mantle in cold subduction zones transport noble gases and water to depths exceeding 200 km. Preservation of seawater-like abundances of Ar, Kr and Xe in the convecting mantle [1] implies that recycling of noble gases and water occurred during cold subduction and that the subduction efficiency of these volatile elements has increased over geological time, driven by secular cooling of the mantle. [1] Holland, G. and Ballentine, C. (2006). Nature 441, 186-191. [2] Jackson et al. (2013). Nat.Geosci. 6, 562-565.

Quick-Change Optical-Filter Holder

NASA Technical Reports Server (NTRS)

Leone, Peter

1988-01-01

Dark slide and interlock protect against ambient light. Quick-change filter holder contains interlocking mechanism preventing simultaneous removal of both dark slide and filter drawer. Designed for use with Band pass optical filters in 10 channels leading to photomultiplier tubes in water-vapor lidar/ozone instrument, mechanism can be modified to operate in other optical systems requiring optical change in filters.

Biological sand filters: low-cost bioremediation technique for production of clean drinking water.

PubMed

Lea, Michael

2014-05-01

Approximately 1.1 billion people in rural and peri-urban communities of developing countries do not have access to safe drinking water. The mortality from diarrheal-related diseases amounts to ∼2.2 million people each year from the consumption of unsafe water. Most of them are children under 5 years of age--250 deaths an hour from microbiologically contaminated water. There is conclusive evidence that one low-cost household bioremediation intervention, use of biological sand filters, is capable of dramatically improving the microbiological quality of drinking water. This unit will describe this relatively new and proven bioremediation technology's ability to empower at-risk populations to use naturally occurring biological principles and readily available materials as a sustainable way to achieve the health benefits of safe drinking water. Copyright © 2014 John Wiley & Sons, Inc.

Biological sand filters: low-cost bioremediation technique for production of clean drinking water.

PubMed

Lea, Michael

2008-05-01

Approximately 1.1 billion people in rural and peri-urban communities of developing countries do not have access to safe drinking water. The mortality from diarrheal-related diseases amounts to approximately 2.2 million people each year from the consumption of unsafe water. Most of them are children under 5 years of age-250 deaths an hour from microbiologically contaminated water. There is conclusive evidence that one low-cost household bioremediation intervention, biological sand filters, are capable of dramatically improving the microbiological quality of drinking water. This unit will describe this relatively new and proven bioremediation technology's ability to empower at-risk populations to use naturally occurring biology and readily available materials as a sustainable way to achieve the health benefits of safe drinking water. Copyright 2008 by John Wiley & Sons, Inc.

Getting Out of Orbit: Water Recycling Requirements and Technology Needs for Long Duration Missions Away from Earth

NASA Technical Reports Server (NTRS)

Barta, Daniel J.

2017-01-01

Deep-space crewed missions will not have regular access to the Earth's resources or the ability to rapidly return to Earth if a system fails. As crewed missions extend farther from Earth for longer periods, habitation systems must become more self-sufficient and reliable for safe, healthy, and sustainable human exploration. For human missions to Mars, Environmental Control and Life Support Systems (ECLSS) must be able operate for up to 1,100 days with minimal spares and consumables. These missions will require capabilities to more fully recycle atmospheric gases and wastewater to substantially reduce mission costs. Even with relatively austere requirements for use, water represents one of the largest consumables by mass. Systems must be available to extract and recycle water from all sources of waste. And given that there will be no opportunity to send samples back to Earth for analysis, analytical measurements will be limited to monitoring hardware brought on board the spacecraft. The Earth Reliant phase of NASA's exploration strategy includes leveraging the International Space Station (ISS) to demonstrate advanced capabilities for a robust and reliable ECLSS. The ISS Water Recovery System (WRS) includes a Urine Processor Assembly (UPA) for distillation and recovery of water from urine and a Water Processor Assembly (WPA) to process humidity condensate and urine distillate into potable water. Possible enhancements to more fully "close the water loop" include recovery of water from waste brines and solid wastes. A possible game changer is the recovery of water from local planetary resources through use of In Situ Resource Utilization (ISRU) technologies. As part of the development and demonstration sequence, NASA intends to utilize cis-Lunar space as a Proving Ground to verify systems for deep space habitation by conducting extended duration missions to validate our readiness for Mars.

Ammonium removal pathways and microbial community in GAC-sand dual media filter in drinking water treatment.

PubMed

Feng, Shuo; Xie, Shuguang; Zhang, Xiaojian; Yang, Zhiyu; Ding, Wei; Liao, Xiaobin; Liu, Yuanyuan; Chen, Chao

2012-01-01

A GAC-sand dual media filter (GSF) was devised as an alternative solution for drinking water treatment plant to tackle the raw water polluted by ammonium in place of expensive ozone-GAC processes or bio-pretreatments. The ammonium removal pathways and microbial community in the GSFs were investigated. The concentrations of ammonium, nitrite and nitrate nitrogen were monitored along the filter. Total inorganic nitrogen (TIN) loss occurred during the filtration. For 1 mg ammonium removal, the TIN loss was as high as 0.35 mg, DO consumption was 3.06 mg, and alkalinity consumption was 5.55 mg. It was assumed that both nitrification and denitrification processes occur in the filters to fit the TIN loss and low DO consumption. During the filtration, nitritation, nitrification and nitritation-anaerobic ammonium oxidation processes probably occur, while traditional nitrification and denitrification and simultaneous nitrification and denitrification processes may occur. In the GSFs, Nitrosomonas and Nitrospira are likely to be involved in nitrification processes, while Novosphingobium, Comamonadaceae and Oxalobacteraceae may be involved in denitrification processes.

Earth observation (Australia) taken by Galileo spacecraft

NASA Technical Reports Server (NTRS)

1990-01-01

Earth observation of Australia was taken by Galileo Spacecraft after completing its first Earth Gravity Assist. Color image of the Simpson Desert in Australia was obtained by Galileo at about 2:30 pm Pacific Standard Time (PST), 12-08-90, at a range of more than 35,000 miles. The color composite was made from images taken through the red, green, and violet filters. The area shown, about 280 miles wide by about 340 miles north-to-south, is southeast of Alice Springs. At lower left is Lake Eyre, a salt lake below sea level, subject to seasonal water-level fluctuations; when this image was acquired the lake was nearly dry. At lower right is the greenish Lake Blanche. Fields of linear sand dunes stretch north and east of Lake Eyre, shaped by prevailing winds from the south and showing, in different colors, the various sources and/or ages of their sands. Photo provided by Jet Propulsion Laboratory (JPL) with alternate number P-37331, 12-19-90.

A role for subducted super-hydrated kaolinite in Earth's deep water cycle

NASA Astrophysics Data System (ADS)

Hwang, Huijeong; Seoung, Donghoon; Lee, Yongjae; Liu, Zhenxian; Liermann, Hanns-Peter; Cynn, Hyunchae; Vogt, Thomas; Kao, Chi-Chang; Mao, Ho-Kwang

2017-12-01

Water is the most abundant volatile component in the Earth. It continuously enters the mantle through subduction zones, where it reduces the melting temperature of rocks to generate magmas. The dehydration process in subduction zones, which determines whether water is released from the slab or transported into the deeper mantle, is an essential component of the deep water cycle. Here we use in situ and time-resolved high-pressure/high-temperature synchrotron X-ray diffraction and infrared spectra to characterize the structural and chemical changes of the clay mineral kaolinite. At conditions corresponding to a depth of about 75 km in a cold subducting slab (2.7 GPa and 200 °C), and in the presence of water, we observe the pressure-induced insertion of water into kaolinite. This super-hydrated phase has a unit cell volume that is about 31% larger, a density that is about 8.4% lower than the original kaolinite and, with 29 wt% H2O, the highest water content of any known aluminosilicate mineral in the Earth. As pressure and temperature approach 19 GPa and about 800 °C, we observe the sequential breakdown of super-hydrated kaolinite. The formation and subsequent breakdown of super-hydrated kaolinite in cold slabs subducted below 200 km leads to the release of water that may affect seismicity and help fuel arc volcanism at the surface.

JPL-20180430-GRACFOf-0001-Twin Satellites to Weigh in on Earths Changing Water

NASA Image and Video Library

2018-04-30

GRACE Follow-On (GRACE-FO), successor to the 15-year GRACE mission (Gravity Recovery and Climate Experiment), will map the mass of water as it moves around Earth from month to month and measure the changing amount of water in the atmosphere. This is a video file.

Composition and stability of bacterial communities associated with granular activated carbon and anthracite filters in a pilot scale municipal drinking water treatment facility.

PubMed

Shirey, T B; Thacker, R W; Olson, J B

2012-06-01

Granular activated carbon (GAC) is an alternative filter substrate for municipal water treatment as it provides a high surface area suitable for microbial colonization. The resulting microbial growth promotes biodegradation of organic materials and other contaminants from influent waters. Here, the community structure of the bacteria associated with three GAC and two anthracite filters was examined over 12 months to monitor changes in community composition. Nearly complete 16S rRNA genes were polymerase chain reaction amplified for terminal restriction fragment length polymorphism (T-RFLP) analyses. The identity of commonly occurring peaks was determined through the construction of five representative 16S rRNA clone libraries. Based on sequence analysis, the bacterial communities associated with both anthracite and GAC filters appear to be composed of environmentally derived bacteria, with no known human pathogens. Analysis of similarity tests revealed that significant differences in bacterial community structure occurred over time, with filter substrate playing an important role in determining community composition. GAC filters exhibited the greatest degree of bacterial community variability over the sampling period, while anthracite filters showed a lower degree of variability and less change in community composition. Thus, GAC may be a suitable biologically active filter substrate for the treatment of municipal drinking water.

MATLAB algorithm to implement soil water data assimilation with the Ensemble Kalman Filter using HYDRUS.

PubMed

Valdes-Abellan, Javier; Pachepsky, Yakov; Martinez, Gonzalo

2018-01-01

Data assimilation is becoming a promising technique in hydrologic modelling to update not only model states but also to infer model parameters, specifically to infer soil hydraulic properties in Richard-equation-based soil water models. The Ensemble Kalman Filter method is one of the most widely employed method among the different data assimilation alternatives. In this study the complete Matlab© code used to study soil data assimilation efficiency under different soil and climatic conditions is shown. The code shows the method how data assimilation through EnKF was implemented. Richards equation was solved by the used of Hydrus-1D software which was run from Matlab. •MATLAB routines are released to be used/modified without restrictions for other researchers•Data assimilation Ensemble Kalman Filter method code.•Soil water Richard equation flow solved by Hydrus-1D.

Through-the-earth radio

DOEpatents

Reagor, David; Vasquez-Dominguez, Jose

2006-12-12

A through-the-earth communication system that includes a digital signal input device; a transmitter operating at a predetermined frequency sufficiently low to effectively penetrate useful distances through-the earth; a data compression circuit that is connected to an encoding processor; an amplifier that receives encoded output from the encoding processor for amplifying the output and transmitting the data to an antenna; and a receiver with an antenna, a band pass filter, a decoding processor, and a data decompressor.

Influence of Coliform Source on Evaluation of Membrane Filters

PubMed Central

Brodsky, M. H.; Schiemann, D. A.

1975-01-01

Four brands of membrane filters were examined for total and fecal coliform recovery performance by two experimental approaches. Using diluted EC broth cultures of water samples, Johns-Manville filters were superior to Sartorius filters for fecal coliform but equivalent for total coliform recovery. Using river water samples, Johns-Manville filters were superior to Sartorius filters for total coliform but equivalent for fecal coliform recovery. No differences were observed between Johns-Manville and Millipore or Millipore and Sartorius filters for total or fecal coliform recoveries using either approach, nor was any difference observed between Millipore and Gelman filters for fecal coliform recovery from river water samples. These results indicate that the source of the coliform bacteria has an important influence on the conclusions of membrane filter evaluation studies. PMID:1106318

Development assessment of wash water reclamation

NASA Technical Reports Server (NTRS)

Putnam, D. F.

1976-01-01

An analytical study assessment of state-of-the-art wash water reclamation technology is presented. It covers all non-phase-change unit operations, unit processes and subsystems currently under development by NASA. Each approach to wash water reclamation is described in detail. Performance data are given together with the projected weights and sizes of key components and subsystems. It is concluded that a simple multifiltration subsystem composed of surface-type cartridge filters, carbon adsorption and ion exchange resins is the most attractive approach for spacecraft wash water reclamation in earth orbital missions of up to 10 years in duration.

Comparison of Various Brands of Membrane Filters for Their Ability to Recover Fungi from Water

PubMed Central

Qureshi, A. A.; Dutka, B. J.

1976-01-01

Five brands of ethylene oxide- and autoclave-sterilized membrane filters were examined for their ability to recover fungi from natural waters. Results showed that the recovery on Gelman membranes was consistently higher than on the other brands tested. PMID:984821

Household-based ceramic water filters for the prevention of diarrhea: a randomized, controlled trial of a pilot program in Colombia.

PubMed

Clasen, Thomas; Garcia Parra, Gloria; Boisson, Sophie; Collin, Simon

2005-10-01

Household water treatment is increasingly recognized as an effective means of reducing the burden of diarrheal disease among low-income populations without access to safe water. Oxfam GB undertook a pilot project to explore the use of household-based ceramic water filters in three remote communities in Colombia. In a randomized, controlled trial over a period of six months, the filters were associated with a 75.3% reduction in arithmetic mean thermotolerant coliforms (TTCs) (P < 0.0001). A total of 47.7% and 24.2% of the samples from the intervention group had no detectible TTCs/100 mL or conformed to World Health Organization limits for low risk (1-10 TTCs/100 mL), respectively, compared with 0.9% and 7.3% for control group samples. Overall, prevalence of diarrhea was 60% less among households using filters than among control households (odds ratio = 0.40, 95% confidence interval = 0.25, 0.63, P < 0.0001). However, the microbiologic performance and protective effect of the filters was not uniform throughout the study communities, suggesting the need to consider the circumstances of the particular setting before implementing this intervention.

Comparison of the bacterial removal performance of silver nanoparticles and a polymer based quaternary amine functiaonalized silsesquioxane coated point-of-use ceramic water filters.

PubMed

Zhang, Hongyin; Oyanedel-Craver, Vinka

2013-09-15

This study compares the disinfection performance of ceramic water filters impregnated with two antibacterial compounds: silver nanoparticles and a polymer based quaternary amine functiaonalized silsesquioxane (poly(trihydroxysilyl) propyldimethyloctadecyl ammonium chloride (TPA)). This study evaluated these compounds using ceramic disks manufactures with clay obtained from a ceramic filter factory located in San Mateo Ixtatan, Guatemala. Instead of using full size ceramic water filters, manufactured 6.5 cm diameter ceramic water filter disks were used. Results showed that TPA can achieve a log bacterial reduction value of 10 while silver nanoparticles reached up to 2 log reduction using a initial concentration of bacteria of 10(10)-10(11)CFU/ml. Similarly, bacterial transport demonstrated that ceramic filter disks painted with TPA achieved a bacterial log reduction value of 6.24, which is about 2 log higher than the values obtained for disks painted with silver nanoparticles (bacterial log reduction value: 4.42). The release of both disinfectants from the ceramic materials to the treated water was determined measuring the effluent concentrations in each test performed. Regarding TPA, about 3% of the total mass applied to the ceramic disks was released in the effluent over 300 min, which is slightly lower than the release percentage for silver nanoparticles (4%). This study showed that TPA provides a comparable disinfection performance than silver nanoparticles in ceramic water filter. Another advantage of using TPA is the cost as the price of TPA is considerable lower than silver nanoparticles. In spite of the use of TPA in several medical related products, there is only partial information regarding the health risk associated with the ingestion of this compound. Additional long-term toxicological information for TPA should be evaluated before its future application in ceramic water filters. Copyright © 2013 Elsevier B.V. All rights reserved.

Water absorption characteristic of interlocking compressed earth brick units

NASA Astrophysics Data System (ADS)

Bakar, B. H. Abu; Saari, S.; Surip, N. A.

2017-10-01

This study aims to investigate the water absorption characteristic of interlocking compressed earth brick (ICEB) units. Apart from compressive strength, water absorption is an important property in masonry. This property can affect the quality of the brick itself and the bond strength between the brick and mortar in masonry structures and can result in reducing its strength properties. The units were tested for 24 h water absorption and 5 h boiling water absorption. A total of 170 ICEB units from four ICEB types underwent both tests. For the 24 h water absorption, the ICEB units were dried in the oven for 24 h and then cooled before being weighed. Thereafter, each brick was immersed in water for 24 h and weighed. The same specimens used for the 24 h water absorption test were re-used for the 5 h boiling water absorption test. After completing the 24 h water absorption test, the brick was boiled for 5-hours and weighed. The highest water absorption for the ICEBs in the 24-hour water absorption and 5 h boiling water absorption tests are 15.09% and 17.18%, respectively. The half brick has the highest water absorption (15.87%), whereas the beam brick has the lowest (13.20%). The water absorption of an ICEB unit is higher than that of normal bricks, although the water absorption of the former remains below the maximum rate of the brick water absorption (21%).

Analyzers Provide Water Security in Space and on Earth

NASA Technical Reports Server (NTRS)

2012-01-01

Resourcefulness is a key quality for living in space, and on the International Space Station (ISS), that means making the most of water supplies. In 2008, the installation of the Water Processing Assembly (WPA) onboard the ISS allowed the space station s crew to do just that. The WPA purifies moisture from nearly every possible source - sweat, water vapor, wastewater, and even urine - for drinking and oxygen generation. Capable of producing 35 gallons of potable, recycled water a day, the system has reduced the need for water delivered to the ISS by over 1,000 gallons a year, saving significant payload costs in the process. As with any drinking water, quality is a concern, particularly when that water has been recycled. This is an issue of particular interest in space, where ISS crewmembers would have to deal with any illness far from the nearest medical personnel and facilities. The WPA employs sensors that monitor water quality by measuring its conductivity, and rounding out the system s quality assurance methods is a device developed for NASA by a private industry partner. That company has now made the technology available for ensuring the purity of water for consumption and industrial uses on Earth.

Arsenic in drinking water wells on the Bolivian high plain: Field monitoring and effect of salinity on removal efficiency of iron-oxides-containing filters.

PubMed

Van Den Bergh, K; Du Laing, G; Montoya, Juan Carlos; De Deckere, E; Tack, F M G

2010-11-01

In the rural areas around Oruro (Bolivia), untreated groundwater is used directly as drinking water. This research aimed to evaluate the general drinking water quality, with focus on arsenic (As) concentrations, based on analysis of 67 samples from about 16 communities of the Oruro district. Subsequently a filter using Iron Oxide Coated Sand (IOCS) and a filter using a Composite Iron Matrix (CIM) were tested for their arsenic removal capacity using synthetic water mimicking real groundwater. Heavy metal concentrations in the sampled drinking water barely exceeded WHO guidelines. Arsenic concentrations reached values up to 964 μ g L⁻¹ and exceeded the current WHO provisional guideline value of 10 μ g L⁻¹ in more than 50% of the sampled wells. The WHO guideline of 250 mg L⁻¹ for chloride and sulphate was also exceeded in more than a third of the samples, indicating high salinity in the drinking waters. Synthetic drinking water could be treated effectively by the IOCS- and CIM-based filters reducing As to concentrations lower than 10 μ g L⁻¹. High levels of chloride and sulphate did not influence As removal efficiency. However, phosphate concentrations in the range from 4 to 24 mg L⁻¹ drastically decreased removal efficiency of the IOCS-based filter but had no effects on removal efficiency of the CIM-based filter. Results of this study can be used as a base for further testing and practical implementation of drinking water purification in the Oruro region.

Preliminary findings on water quality of ricing lakes on White Earth Reservation, MN

USDA-ARS?s Scientific Manuscript database

Wild rice is a cultural and economic staple of the Anishinaabe People of White Earth. Changes in land use within the watershed may impact the water quality of ricing lakes on the reservation. The purpose of this discussion is to report the preliminary findings of water quality analysis of samples ta...

Process evaluation and assessment of use of a large scale water filter and cookstove program in Rwanda.

PubMed

Barstow, Christina K; Nagel, Corey L; Clasen, Thomas F; Thomas, Evan A

2016-07-16

In an effort to reduce the disease burden in rural Rwanda, decrease poverty associated with expenditures for fuel, and minimize the environmental impact on forests and greenhouse gases from inefficient combustion of biomass, the Rwanda Ministry of Health (MOH) partnered with DelAgua Health (DelAgua), a private social enterprise, to distribute and promote the use of improved cookstoves and advanced water filters to the poorest quarter of households (Ubudehe 1 and 2) nationally, beginning in Western Province under a program branded Tubeho Neza ("Live Well"). The project is privately financed and earns revenue from carbon credits under the United Nations Clean Development Mechanism. During a 3-month period in late 2014, over 470,000 people living in over 101,000 households were provided free water filters and cookstoves. Following the distribution, community health workers visited nearly 98 % of households to perform household level education and training activities. Over 87 % of households were visited again within 6 months with a basic survey conducted. Detailed adoption surveys were conducted among a sample of households, 1000 in the first round, 187 in the second. Approximately a year after distribution, reported water filter use was above 90 % (+/-4 % CI) and water present in filter was observed in over 76 % (+/-6 % CI) of households, while the reported primary stove was nearly 90 % (+/-4.4 % CI) and of households cooking at the time of the visit, over 83 % (+/-5.3 % CI) were on the improved stove. There was no observed association between household size and stove stacking behavior. This program suggests that free distribution is not a determinant of low adoption. It is plausible that continued engagement in households, enabled by Ministry of Health support and carbon financed revenue, contributed to high adoption rates. Overall, the program was able to demonstrate a privately financed, public health intervention can achieve high levels of initial

Developing an Earth system Inverse model for the Earth's energy and water budgets.

NASA Astrophysics Data System (ADS)

Haines, K.; Thomas, C.; Liu, C.; Allan, R. P.; Carneiro, D. M.

2017-12-01

The CONCEPT-Heat project aims at developing a consistent energy budget for the Earth system in order to better understand and quantify global change. We advocate a variational "Earth system inverse" solution as the best methodology to bring the necessary expertise from different disciplines together. L'Ecuyer et al (2015) and Rodell et al (2015) first used a variational approach to adjust multiple satellite data products for air-sea-land vertical fluxes of heat and freshwater, achieving closed budgets on a regional and global scale. However their treatment of horizontal energy and water redistribution and its uncertainties was limited. Following the recent work of Liu et al (2015, 2017) which used atmospheric reanalysis convergences to derive a new total surface heat flux product from top of atmosphere fluxes, we have revisited the variational budget approach introducing a more extensive analysis of the role of horizontal transports of heat and freshwater, using multiple atmospheric and ocean reanalysis products. We find considerable improvements in fluxes in regions such as the North Atlantic and Arctic, for example requiring higher atmospheric heat and water convergences over the Arctic than given by ERA-Interim, thereby allowing lower and more realistic oceanic transports. We explore using the variational uncertainty analysis to produce lower resolution corrections to higher resolution flux products and test these against in situ flux data. We also explore the covariance errors implied between component fluxes that are imposed by the regional budget constraints. Finally we propose this as a valuable methodology for developing consistent observational constraints on the energy and water budgets in climate models. We take a first look at the same regional budget quantities in CMIP5 models and consider the implications of the differences for the processes and biases active in the models. Many further avenues of investigation are possible focused on better valuing

33 CFR 183.534 - Fuel filters and strainers.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Fuel filters and strainers. 183.534 Section 183.534 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... filters and strainers. If tested under § 183.590, each fuel filter and strainer, as installed in the boat...

33 CFR 183.534 - Fuel filters and strainers.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Fuel filters and strainers. 183.534 Section 183.534 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... filters and strainers. If tested under § 183.590, each fuel filter and strainer, as installed in the boat...

33 CFR 183.534 - Fuel filters and strainers.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Fuel filters and strainers. 183.534 Section 183.534 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... filters and strainers. If tested under § 183.590, each fuel filter and strainer, as installed in the boat...

33 CFR 183.534 - Fuel filters and strainers.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Fuel filters and strainers. 183.534 Section 183.534 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... filters and strainers. If tested under § 183.590, each fuel filter and strainer, as installed in the boat...

33 CFR 183.534 - Fuel filters and strainers.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Fuel filters and strainers. 183.534 Section 183.534 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... filters and strainers. If tested under § 183.590, each fuel filter and strainer, as installed in the boat...

Hydrodynamics of microbial filter feeding

PubMed Central

Asadzadeh, Seyed Saeed; Dölger, Julia; Walther, Jens H.; Andersen, Anders

2017-01-01

Microbial filter feeders are an important group of grazers, significant to the microbial loop, aquatic food webs, and biogeochemical cycling. Our understanding of microbial filter feeding is poor, and, importantly, it is unknown what force microbial filter feeders must generate to process adequate amounts of water. Also, the trade-off in the filter spacing remains unexplored, despite its simple formulation: A filter too coarse will allow suitably sized prey to pass unintercepted, whereas a filter too fine will cause strong flow resistance. We quantify the feeding flow of the filter-feeding choanoflagellate Diaphanoeca grandis using particle tracking, and demonstrate that the current understanding of microbial filter feeding is inconsistent with computational fluid dynamics (CFD) and analytical estimates. Both approaches underestimate observed filtration rates by more than an order of magnitude; the beating flagellum is simply unable to draw enough water through the fine filter. We find similar discrepancies for other choanoflagellate species, highlighting an apparent paradox. Our observations motivate us to suggest a radically different filtration mechanism that requires a flagellar vane (sheet), something notoriously difficult to visualize but sporadically observed in the related choanocytes (sponges). A CFD model with a flagellar vane correctly predicts the filtration rate of D. grandis, and using a simple model we can account for the filtration rates of other microbial filter feeders. We finally predict how optimum filter mesh size increases with cell size in microbial filter feeders, a prediction that accords very well with observations. We expect our results to be of significance for small-scale biophysics and trait-based ecological modeling. PMID:28808016

Hydrodynamics of microbial filter feeding.

PubMed

Nielsen, Lasse Tor; Asadzadeh, Seyed Saeed; Dölger, Julia; Walther, Jens H; Kiørboe, Thomas; Andersen, Anders

2017-08-29

Microbial filter feeders are an important group of grazers, significant to the microbial loop, aquatic food webs, and biogeochemical cycling. Our understanding of microbial filter feeding is poor, and, importantly, it is unknown what force microbial filter feeders must generate to process adequate amounts of water. Also, the trade-off in the filter spacing remains unexplored, despite its simple formulation: A filter too coarse will allow suitably sized prey to pass unintercepted, whereas a filter too fine will cause strong flow resistance. We quantify the feeding flow of the filter-feeding choanoflagellate Diaphanoeca grandis using particle tracking, and demonstrate that the current understanding of microbial filter feeding is inconsistent with computational fluid dynamics (CFD) and analytical estimates. Both approaches underestimate observed filtration rates by more than an order of magnitude; the beating flagellum is simply unable to draw enough water through the fine filter. We find similar discrepancies for other choanoflagellate species, highlighting an apparent paradox. Our observations motivate us to suggest a radically different filtration mechanism that requires a flagellar vane (sheet), something notoriously difficult to visualize but sporadically observed in the related choanocytes (sponges). A CFD model with a flagellar vane correctly predicts the filtration rate of D. grandis , and using a simple model we can account for the filtration rates of other microbial filter feeders. We finally predict how optimum filter mesh size increases with cell size in microbial filter feeders, a prediction that accords very well with observations. We expect our results to be of significance for small-scale biophysics and trait-based ecological modeling.

Performance of ceramic disk filter coated with nano ZnO for removing Escherichia coli from water in small rural and remote communities of developing regions.

PubMed

Huang, Jing; Huang, Guohe; An, Chunjiang; He, Yuan; Yao, Yao; Zhang, Peng; Shen, Jian

2018-07-01

Global water safety is facing great challenges due to increased population and demand. There is an urgent need to develop suitable water treatment strategy for small rural and remote communities in low-income developing countries. In order to find a low-cost solution, the reduction of E. coli using ceramic water disk coated with nano ZnO was investigated in this study. The performance of modified ceramic disk filters was influenced by several factors in the filter production process. Based on the factorial analysis, the pore size of the disk filters was the most significant factor for influencing E. coli removal efficiency and the clay content was the most significant one for influencing flow rate of modified disk filters. The coating of nano ZnO led to the change of disk filter surface and porosity. The reduction of E. coli could be attributed to both filter retention and photocatalytic antibacterial activity of nano ZnO. The effects of filter operation factors including initial E. coli concentration, illumination time and lamp power on E. coli removal effectiveness were also revealed. The results can help find a safe and cost-effective approach to solve drinking water problems in small rural and remote communities of developing regions. Copyright © 2018 Elsevier Ltd. All rights reserved.

DSCOVR/EPIC Images and Science: A New Way to View the Entire Sunlit Earth From A Sun-Earth Lagrange-1 Orbit

NASA Astrophysics Data System (ADS)

Herman, J. R.; Marshak, A.; Szabo, A.

2015-12-01

The DSCOVR mission was launched into a Sun-Earth Lagrange-1 orbit 1.5 million kilometers from earth in February 2015 onboard a SpaceX Falcon-9 rocket. The solar wind and earth science instruments were tested during the 4.5 month journey to L-1. The first data were obtained during the June-July commissioning phase, which included the first moderate resolution (10 km) color images of the entire sunlit earth, color images of the Moon, and scientific data from 10 narrow band filters (317.5, 325, 340, 388, 443, 551, 680, 687.75, 764, and 779.5 nm). Three of these filters were used to construct the color images (443, 551, 680 nm) based on the average eye response histogram of the sunlit earth. This talk will discuss some of the issues involved in deriving science quality data for global ozone, the aerosol index (dust, smoke, and volcanic ash), cloud amounts and reflectivity, and cloud height (measured from the O2 A- and B-bands). As with most new satellites, the science data are preliminary.

Activated charcoal filters: Water treatment, pollution control, and industrial applications. October 1970-October 1989 (Citations from the US Patent data base). Report for October 1970-October 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This bibliography contains citations of selected patents concerning activated charcoal filters and their applications in water treatment, pollution control, and industrial processes. Filtering methods and equipment for air and water purification, industrial distillation and extraction, industrial leaching, and filtration of toxic materials and contaminants are described. Applications include drinking water purification, filtering beverages, production of polymer materials, solvent and metal recovery, waste conversion, automotive fuel and exhaust systems, swimming-pool filtration, tobacco-smoke filters, kitchen ventilators, medical filtration treatment, and odor-absorbing materials. (This updated bibliography contains 173 citations, 12 of which are new entries to the previous edition.)

Activated-charcoal filters: Water treatment, pollution control, and industrial applications. January 1970-August 1989 (Citations from the US Patent data base). Report for January 1970-August 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This bibliography contains citations of selected patents concerning activated charcoal filters and their applications in water treatment, pollution control, and industrial processes. Filtering methods and equipment for air and water purification, industrial distillation and extraction, industrial leaching, and filtration of toxic materials and contaminants are described. Applications include drinking-water purification, filtering beverages, production of polymer materials, solvent and metal recovery, waste conversion, automotive fuel and exhaust systems, swimming-pool filtration, tobacco-smoke filters, kitchen ventilators, medical-filtration treatment, and odor absorbing materials. (This updated bibliography contains 161 citations, 32 of which are new entries to the previous edition.)

Aquatic Plants Aid Sewage Filter

NASA Technical Reports Server (NTRS)

Wolverton, B. C.

1985-01-01

Method of wastewater treatment combines micro-organisms and aquatic plant roots in filter bed. Treatment occurs as liquid flows up through system. Micro-organisms, attached themselves to rocky base material of filter, act in several steps to decompose organic matter in wastewater. Vascular aquatic plants (typically, reeds, rushes, cattails, or water hyacinths) absorb nitrogen, phosphorus, other nutrients, and heavy metals from water through finely divided roots.

Galileo's Earth-Moon portrait

NASA Astrophysics Data System (ADS)

Simarski, Lynn Teo

Research reported at an AGU session on Galileo's Earth/Moon flyby refined the spacecraft's distinctive portrait of the Earth-Moon system. The Galileo team presented dramatic new views of the Earth and Moon taken last December. Andrew P. Ingersoll showed a color movie of the rotating Earth, made through spectral filters with which Galileo viewed the Earth almost continuously for 25 hours.Galileo also made finely tuned observations of vegetation and clouds, using three very closely spaced spectral wavelengths in the near-infrared, explained W. Reid Thompson. In the resulting images, Argentinian grassland and Brazilian rain forest are clearly distinguished, demonstrating the applicability of this technique for routine monitoring of deforestation, shifts in vegetation due to climate, and other phenomena. Thompson suggested that this capability could be used on the Earth Observing System. One of the spectral bands may also have potential for monitoring cloud condensation, as it appears to differentiate actively condensing, vapor-heavy clouds from higher and drier clouds.

Two drastically different climate states on an Earth-like land planet with overland water recycling

NASA Astrophysics Data System (ADS)

Kalidindi, S.; Reick, C. H.; Raddatz, T.; Claussen, M.

2017-12-01

Prior studies have demonstrated that habitable areas on low-obliquity land planets are confined to the edges of frozen ice caps. Whether such dry planets can maintain long-lived liquid water is unclear. Leconte et al. 2013 argue that on such planets mechanisms like gravity driven ice flows and geothermal flux can maintain liquid water at the edges of thick ice caps and this water may flow back to the lower latitudes through rivers. However, there exists no modelling study which investigates the climate of an Earth-like land planet with an overland recycling mechanism bringing fresh water back from higher to lower latitudes. In our study, by using a comprehensive climate model ICON, we find that an Earth-like land planet with an overland recycling mechanism can exist in two drastically different climate states for the same set of boundary conditions and parameter values: A Cold and Wet (CW) state with dominant low-latitude precipitation and, a Hot and Dry (HD) state with only high-latitude precipitation. For perpetual equinox conditions, both climate states are stable below a certain threshold value of background soil albedo (α) while above that only the CW state is stable. Starting from the HD state and increasing α above the threshold causes an abrupt shift from the HD state to the CW state resulting in a sudden cooling of about 35°C globally which is of the order of the temperature difference between the present-day and the Snowball Earth state. In contrast to the Snowball Earth instability, we find that the sudden cooling in our study is driven by the cloud albedo feedback rather than the snow-albedo feedback. Also, when α in the CW state is reduced back to zero the land planet does not display a closed hysteresis. Our study also has implications for the habitability of Earth-like land planets. At the inner edge of the habitable zone, the higher cloud cover in the CW state cools the planet and may prevent the onset of a runaway greenhouse state. At the outer

The effects of the Asselin time filter on numerical solutions to the linearized shallow-water wave equations

NASA Technical Reports Server (NTRS)

Schlesinger, R. E.; Johnson, D. R.; Uccellini, L. W.

1983-01-01

In the present investigation, a one-dimensional linearized analysis is used to determine the effect of Asselin's (1972) time filter on both the computational stability and phase error of numerical solutions for the shallow water wave equations, in cases with diffusion but without rotation. An attempt has been made to establish the approximate optimal values of the filtering parameter nu for each of the 'lagged', Dufort-Frankel, and Crank-Nicholson diffusion schemes, suppressing the computational wave mode without materially altering the physical wave mode. It is determined that in the presence of diffusion, the optimum filter length depends on whether waves are undergoing significant propagation. When moderate propagation is present, with or without diffusion, the Asselin filter has little effect on the spatial phase lag of the physical mode for the leapfrog advection scheme of the three diffusion schemes considered.

Process for treating earth formations to be relatively inpermeable to formation water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peacock, D.W.

1966-12-13

In a method for treatment of earth formations to make them relatively impermeable to formation water, high pH water is introduced through the bore into the formation under sufficient pressure to force the formation water out of the formation being treated. Thereafter, a high pH additive solution is introduced into the formation through the well bore. The pH of the additive solution is lowered in situ to precipitate the additive in the formation, thus shutting off the flow of water from the formation into the well. The additive is a tannin obtained from flavotannins, gallotannins, and mixed tannins. (7 claims)

A Circum-terrestrial Compositional Filter

NASA Technical Reports Server (NTRS)

Chapman, C. R.; Greenberg, R.

1985-01-01

A major question about the moon is its under abundance of iron. It is the purpose of this research to understand whether a metal-silicate fractionation of heliocentrically orbiting bodies can be achieved through collisional interactions with a circum-terrestrial swarm. Rates of diffusion are investigated and the mutual collisional destruction within the population is examined. The interactions of these differentiated planetesimals and their collisional products (both silicate mantle fragments and iron cores) with a swarm of Earth orbiting lunesimals (perhaps ejecta from the Earth) of km scale, totaling a mass of order 0.1 lunar mass, extending out 10 or 20 Earth radii are considered. It is found that such a small near Earth population of lunesimals can filter out silicate rich material, while passing iron cores, and form a moon composed partly of terrestrial material, but more substantially of the captured silicate rich portions of the planetesimals.

COMPARISON OF MEMBRANE FILTER, MULTIPLE-FERMENTATION-TUBE, AND PRESENCE-ABSENCE TECHNIQUES FOR DETECTING TOTAL COLIFORMS IN SMALL COMMUNITY WATER SYSTEMS

EPA Science Inventory

Methods for detecting total coliform bacteria in drinking water were compared using 1483 different drinking water samples from 15 small community water systems in Vermont and New Hampshire. The methods included the membrane filter (MF) technique, a ten tube fermentation tube tech...

Effects of dynamic operating conditions on nitrification in biological rapid sand filters for drinking water treatment.

PubMed

Lee, Carson O; Boe-Hansen, Rasmus; Musovic, Sanin; Smets, Barth; Albrechtsen, Hans-Jørgen; Binning, Philip

2014-11-01

Biological rapid sand filters are often used to remove ammonium from groundwater for drinking water supply. They often operate under dynamic substrate and hydraulic loading conditions, which can lead to increased levels of ammonium and nitrite in the effluent. To determine the maximum nitrification rates and safe operating windows of rapid sand filters, a pilot scale rapid sand filter was used to test short-term increased ammonium loads, set by varying either influent ammonium concentrations or hydraulic loading rates. Ammonium and iron (flock) removal were consistent between the pilot and the full-scale filter. Nitrification rates and ammonia-oxidizing bacteria and archaea were quantified throughout the depth of the filter. The ammonium removal capacity of the filter was determined to be 3.4 g NH4-N m(-3) h(-1), which was 5 times greater than the average ammonium loading rate under reference operating conditions. The ammonium removal rate of the filter was determined by the ammonium loading rate, but was independent of both the flow and influent ammonium concentration individually. Ammonia-oxidizing bacteria and archaea were almost equally abundant in the filter. Both ammonium removal and ammonia-oxidizing bacteria density were strongly stratified, with the highest removal and ammonia-oxidizing bacteria densities at the top of the filter. Cell specific ammonium oxidation rates were on average 0.6 × 10(2) ± 0.2 × 10(2) fg NH4-N h(-1) cell(-1). Our findings indicate that these rapid sand filters can safely remove both nitrite and ammonium over a larger range of loading rates than previously assumed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Response of the water level in a well to Earth tides and atmospheric loading under unconfined conditions

USGS Publications Warehouse

Rojstaczer, Stuart; Riley, Francis S.

1990-01-01

The response of the water level in a well to Earth tides and atmospheric loading under unconfined conditions can be explained if the water level is controlled by the aquifer response averaged over the saturated depth of the well. Because vertical averaging tends to diminish the influence of the water table, the response is qualitatively similar to the response of a well under partially confined conditions. When the influence of well bore storage can be ignored, the response to Earth tides is strongly governed by a dimensionless aquifer frequency Q′u. The response to atmospheric loading is strongly governed by two dimensionless vertical fluid flow parameters: a dimensionless unsaturated zone frequency, R, and a dimensionless aquifer frequency Qu. The differences between Q′u and Qu are generally small for aquifers which are highly sensitive to Earth tides. When Q′u and Qu are large, the response of the well to Earth tides and atmospheric loading approaches the static response of the aquifer under confined conditions. At small values of Q′u and Qu, well response to Earth tides and atmospheric loading is strongly influenced by water table drainage. When R is large relative to Qu, the response to atmospheric loading is strongly influenced by attenuation and phase shift of the pneumatic pressure signal in the unsaturated zone. The presence of partial penetration retards phase advance in well response to Earth tides and atmospheric loading. When the theoretical response of a phreatic well to Earth tides and atmospheric loading is fit to the well response inferred from cross-spectral estimation, it is possible to obtain estimates of the pneumatic diffusivity of the unsaturated zone and the vertical hydraulic conductivity of the aquifer.

Response of the Water Level in a Well to Earth Tides and Atmospheric Loading Under Unconfined Conditions

NASA Astrophysics Data System (ADS)

Rojstaczer, Stuart; Riley, Francis S.

1990-08-01

The response of the water level in a well to Earth tides and atmospheric loading under unconfined conditions can be explained if the water level is controlled by the aquifer response averaged over the saturated depth of the well. Because vertical averaging tends to diminish the influence of the water table, the response is qualitatively similar to the response of a well under partially confined conditions. When the influence of well bore storage can be ignored, the response to Earth tides is strongly governed by a dimensionless aquifer frequency Q'u. The response to atmospheric loading is strongly governed by two dimensionless vertical fluid flow parameters: a dimensionless unsaturated zone frequency, R, and a dimensionless aquifer frequency Qu. The differences between Q'u and Qu are generally small for aquifers which are highly sensitive to Earth tides. When Q'u and Qu are large, the response of the well to Earth tides and atmospheric loading approaches the static response of the aquifer under confined conditions. At small values of Q'u and Qu, well response to Earth tides and atmospheric loading is strongly influenced by water table drainage. When R is large relative to Qu, the response to atmospheric loading is strongly influenced by attenuation and phase shift of the pneumatic pressure signal in the unsaturated zone. The presence of partial penetration retards phase advance in well response to Earth tides and atmospheric loading. When the theoretical response of a phreatic well to Earth tides and atmospheric loading is fit to the well response inferred from cross-spectral estimation, it is possible to obtain estimates of the pneumatic diffusivity of the unsaturated zone and the vertical hydraulic conductivity of the aquifer.

Capsule- and disk-filter procedure

USGS Publications Warehouse

Skrobialowski, Stanley C.

2016-01-01

Capsule and disk filters are disposable, self-contained units composed of a pleated or woven filter medium encased in a polypropylene or other plastic housing that can be connected inline to a sample-delivery system (such as a submersible or peristaltic pump) that generates sufficient pressure (positive or negative) to force water through the filter. Filter media are available in several pore sizes, but 0.45 µm is the pore size used routinely for most studies at this time. Capsule or disk filters (table 5.2.1.A.1) are required routinely for most studies when filtering samples for trace-element analyses and are recommended when filtering samples for major-ion or other inorganic-constituent analyses.

Biological filters and their use in potable water filtration systems in spaceflight conditions

NASA Astrophysics Data System (ADS)

Thornhill, Starla G.; Kumar, Manish

2018-05-01

Providing drinking water to space missions such as the International Space Station (ISS) is a costly requirement for human habitation. To limit the costs of water transport, wastewater is collected and purified using a variety of physical and chemical means. To date, sand-based biofilters have been designed to function against gravity, and biofilms have been shown to form in microgravity conditions. Development of a universal silver-recycling biological filter system that is able to function in both microgravity and full gravity conditions would reduce the costs incurred in removing organic contaminants from wastewater by limiting the energy and chemical inputs required. This paper aims to propose the use of a sand-substrate biofilter to replace chemical means of water purification on manned spaceflights.

Water depth penetration film test

NASA Technical Reports Server (NTRS)

Lockwood, H. E.; Perry, L.; Sauer, G. E.; Lamar, N. T.

1974-01-01

As part of the National Aeronautics and Space Administration Earth Resources Program, a comparative and controlled evaluation of nine film-filter combinations was completed to establish the relative effectiveness in recording water subsurface detail if exposed from an aerial platform over a typical water body. The films tested, with one exception, were those which prior was suggested had potential. These included an experimental 2-layer positive color film, a 2-layer (minus blue layer) film, a normal 3-layer color film, a panchromatic black-and-white film, and a black-and-white infrared film. Selective filtration was used with all films.

Thermal control design of the Lightning Mapper Sensor narrow-band spectral filter

NASA Technical Reports Server (NTRS)

Flannery, Martin R.; Potter, John; Raab, Jeff R.; Manlief, Scott K.

1992-01-01

The performance of the Lightning Mapper Sensor is dependent on the temperature shifts of its narrowband spectral filter. To perform over a 10 degree FOV with an 0.8 nm bandwidth, the filter must be 15 cm in diameter and mounted externally to the telescope optics. The filter thermal control required a filter design optimized for minimum bandpass shift with temperature, a thermal analysis of substrate materials for maximum temperature uniformity, and a thermal radiation analysis to determine the parameter sensitivity of the radiation shield for the filter, the filter thermal recovery time after occultation, and heater power to maintain filter performance in the earth-staring geosynchronous environment.

Monitoring of coalbed water retention ponds in the Powder River Basin using Google Earth images and an Unmanned Aircraft System

NASA Astrophysics Data System (ADS)

Zhou, X.; Zhou, Z.; Apple, M. E.; Spangler, L.

2016-12-01

To extract methane from unminable seams of coal in the Powder River Basin of Montana and Wyoming, coalbed methane (CBM) water has to be pumped and kept in retention ponds rather than discharged to the vadose zone to mix with the ground water. The water areal coverage of these ponds changes due to evaporation and repetitive refilling. The water quality also changes due to growing of microalgae (unicellular or filamentous including green algae and diatoms), evaporation, and refilling. To estimate the water coverage changes and monitor water quality becomes important for monitoring the CBM water retention ponds to provide timely management plan for the newly pumped CBM water. Conventional methods such as various water indices based on multi-spectral satellite data such as Landsat because of the small pond size ( 100mx100m scale) and low spatial resolution ( 30m scale) of the satellite data. In this study we will present new methods to estimate water coverage and water quality changes using Google Earth images and images collected from an unmanned aircraft system (UAS) (Phantom 2 plus). Because these images have only visible bands (red, green, and blue bands), the conventional water index methods that involve near-infrared bands do not work. We design a new method just based on the visible bands to automatically extract water pixels and the intensity of the water pixel as a proxy for water quality after a series of image processing such as georeferencing, resampling, filtering, etc. Differential GPS positions along the water edges were collected the same day as the images collected from the UAS. Area of the water area was calculated from the GPS positions and used for the validation of the method. Because of the very high resolution ( 10-30 cm scale), the water areal coverage and water quality distribution can be accurately estimated. Since the UAS can be flied any time, water area and quality information can be collected timely.

Fabrication of highly hydrophilic filter using natural and hydrothermally treated mica nanoparticles for efficient waste oil-water separation.

PubMed

Gunatilake, Udara Bimendra; Bandara, Jayasundera

2017-04-15

For the effective oil/water separation, a novel superhydrophilic (underwater superoleophobic) filter is fabricated with the naturally and hydrothermally treated mica particles. To fabricate a double layered filter, hydrothermally treated mica particles were initially electrodeposited on a stainless steel mesh and a natural mica particles were sprayed on the first hydrothermally deposited mica layer. The double layered mica coated membrane showed superamphiphilic and superhydrophilic/superoleophobic (contact angle >159°) characteristics in air and underwater respectively. The membrane can separate range of oil-water mixtures with oil/water separation efficiency over ∼99%. Properties of double layered mica membrane were investigated and noted that the surface adhesion properties of mica is enhanced by the hydrothermal treatment of mica and the higher roughness of the mica layer is maintained by the natural mica. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dataset on the spent filter backwash water treatment by sedimentation, coagulation and ultra filtration.

PubMed

Mahdavi, Mokhtar; Ebrahimi, Afshin; Azarpira, Hossein; Tashauoei, Hamid Reza; Mahvi, Amir Hossein

2017-12-01

During operation of most water treatment plants, spent filter backwash water (SFBW) is generated, which accounts about 2-10% of the total plant production. By increasing world population and water shortage in many countries, SFBW can be used as a permanent water source until the water treatment plant is working. This data article reports the practical method being used for water reuse from SFBW through different method including pre-sedimentation, coagulation and flocculation, second clarification, ultra filtration (UF) and returned settled SFBW to the beginning of water treatment plant (WTP). Also, two coagulants of polyaluminum ferric chloride (PAFCl) and ferric chloride (FeCl 3 ) were investigated with respect to their performance on treated SFBW quality. Samples were collected from Isfahan's WTP in Iran during spring and summer season. The acquired data indicated that drinkable water can be produced form SFBW by applying hybrid coagulation-UF process (especially when PAFCl used as coagulant).

A Randomized Controlled Trial to Assess the Impact of Ceramic Water Filters on Prevention of Diarrhea and Cryptosporidiosis in Infants and Young Children-Western Kenya, 2013.

PubMed

Morris, Jamae Fontain; Murphy, Jennifer; Fagerli, Kirsten; Schneeberger, Chandra; Jaron, Peter; Moke, Fenny; Juma, Jane; Ochieng, J Ben; Omore, Richard; Roellig, Dawn; Xiao, Lihua; Priest, Jeffrey W; Narayanan, Jothikumar; Montgomery, Joel; Hill, Vince; Mintz, Eric; Ayers, Tracy L; O'Reilly, Ciara E

2018-04-02

Cryptosporidium is a leading cause of diarrhea among Kenyan infants. Ceramic water filters (CWFs) are used for household water treatment. We assessed the impact of CWFs on diarrhea, cryptosporidiosis prevention, and water quality in rural western Kenya. A randomized, controlled intervention trial was conducted in 240 households with infants 4-10 months old. Twenty-six weekly household surveys assessed infant diarrhea and health facility visits. Stool specimens from infants with diarrhea were examined for Cryptosporidium . Source water, filtered water, and filter retentate were tested for Cryptosporidium and/or microbial indicators. To estimate the effect of CWFs on health outcomes, logistic regression models using generalized estimating equations were performed; odds ratios (ORs) and 95% confidence intervals (CIs) are reported. Households reported using surface water (36%), public taps (29%), or rainwater (17%) as their primary drinking water sources, with no differences in treatment groups. Intervention households reported less diarrhea (7.6% versus 8.9%; OR: 0.86 [0.64-1.16]) and significantly fewer health facility visits for diarrhea (1.0% versus 1.9%; OR: 0.50 [0.30-0.83]). In total, 15% of intervention and 12% of control stools yielded Cryptosporidium ( P = 0.26). Escherichia coli was detected in 93% of source water samples; 71% of filtered water samples met World Health Organization recommendations of < 1 E. coli /100 mL. Cryptosporidium was not detected in source water and was detected in just 2% of filter rinses following passage of large volumes of source water. Water quality was improved among CWF users; however, the short study duration and small sample size limited our ability to observe reductions in cryptosporidiosis.

Pilot study on control of phytoplankton by zooplankton coupling with filter-feeding fish in surface water.

PubMed

Ma, Hua; Cui, Fuyi; Liu, Zhiquan; Fan, Zhenqiang

2009-01-01

A pilot-scale facility was originally designed to control phytoplankton in algae-laden reservoir water characterized by summer cyanobacteria blooms (mainly Microcystis flos-aquae). The system made good use of the different food habits of Daphnia magna and silver carp. Zooplankton (Daphnia magna), filter-feeding fish (silver carp), and zooplankton (Daphnia magna) were stocked in three separated tanks in sequence, respectively. Thus, single-cell phytoplankton and some Microcystis flos-aquae in small size were first grazed by Daphnia magna in the first tank, and in the second tank phytoplankton larger than 10 microm were filtered by silver carp, and the concentration of the remaining phytoplankton was further reduced to a rather low level by Daphnia magna in the third tank. The results showed that the system had good removal efficiencies of phytoplankton and chlorophyll a, 86.85% and 59.41%, respectively, and permanganate consumption (COD(Mn)) and turbidity were lowered as well. A high phytoplankton removal efficiency and low cost indicated that the system had a good advantage in pre-treating algae-laden source water in drinking water works.

Fremont Tree-Well Filter

EPA Pesticide Factsheets

Information about the SFBWQP Fremont Tree-Well Filter Spine project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

The ability to use remote polarization studies of Earth from space in the national economy (Project of the onboard filter panoramic polarimeter)

NASA Astrophysics Data System (ADS)

Nevodovskyi, P. V.; Vidmachenko, A. P.; Geraimchuk, M. D.; Ivahiv, O. V.

2016-10-01

Remote polarization studies are a very powerful method of solving of astronomical tasks with the study of the physical properties of the planets and their atmospheres. It allows research of objects as in situ, so in vitro, and has many other advantages. To use this method has already been developed and are continuing the development of many various special instruments called polarimeters. The essence of the space experiment consists in the fact to using the polarimeter installed on board a micro satellite, systematically, during each of its revolutions around the Earth, to monitor a polarization components of a diffusely reflected by atmosphere solar radiation in different, previously stipulated wavelengths. There are a lot of the optical schemes, which are used in devices of measuring and monitoring of parameters of polarized radiation, including those into space experiments of probing of the Earth's atmosphere from orbit of satellites. In this paper we analyze the potential for use of filter-polarimeter to measure the Stokes vector components.

Comparison of filters for concentrating microbial indicators and pathogens in lake-water samples

USGS Publications Warehouse

Francy, Donna S.; Stelzer, Erin A.; Brady, Amie M.G.; Huitger, Carrie; Bushon, Rebecca N.; Ip, Hon S.; Ware, Michael W.; Villegas, Eric N.; Gallardo, Vincent; Lindquist, H.D. Alan

2013-01-01

Bacterial indicators are used to indicate increased health risk from pathogens and to make beach closure and advisory decisions; however, beaches are seldom monitored for the pathogens themselves. Studies of sources and types of pathogens at beaches are needed to improve estimates of swimming-associated health risks. It would be advantageous and cost-effective, especially for studies conducted on a regional scale, to use a method that can simultaneously filter and concentrate all classes of pathogens from the large volumes of water needed to detect pathogens. In seven recovery experiments, stock cultures of viruses and protozoa were seeded into 10-liter lake water samples, and concentrations of naturally occurring bacterial indicators were used to determine recoveries. For the five filtration methods tested, the highest median recoveries were as follows: glass wool for adenovirus (4.7%); NanoCeram for enterovirus (14.5%) and MS2 coliphage (84%); continuous-flow centrifugation (CFC) plus Virocap (CFC+ViroCap) for Escherichia coli (68.3%) and Cryptosporidium (54%); automatic ultrafiltration (UF) for norovirus GII (2.4%); and dead-end UF for Enterococcus faecalis (80.5%), avian influenza virus (0.02%), and Giardia (57%). In evaluating filter performance in terms of both recovery and variability, the automatic UF resulted in the highest recovery while maintaining low variability for all nine microorganisms. The automatic UF was used to demonstrate that filtration can be scaled up to field deployment and the collection of 200-liter lake water samples.

Assessment of addition of biochar to filtering mixtures for potential water pollutant removal.

PubMed

Piscitelli, Lea; Rivier, Pierre-Adrien; Mondelli, Donato; Miano, Teodoro; Joner, Erik J

2018-01-01

Green roofs are used increasingly to alleviate peaks of water discharge into the sewage systems in urban areas. Surface runoff from roofs contain pollutants from dry and wet deposition, and green roofs offer a possibility to reduce the amounts of pollutants in the water discharged from roofs by degradation and filtering. These pollutants would otherwise enter wastewater treatments plants and ultimately end up in sewage sludge that is spread on agricultural soils. The most common substrates used in green roofs have limited capacity for filtration and sorption. Also, more sustainable alternatives are sought, due to the high carbon footprint of these materials. Biochar is a carbon-rich material produced by pyrolysis of biomass, and several types of biochar have been described as good sorbents and filter materials. Biochar is also a light and carbon negative material, which may fulfill other desired criteria for new green roof substrates. We here report on an experiment where two types of biochar, produced from olive husks at 450 °C or from forest waste at 850 ° C were mixed with volcanic rock or peat, and tested for retention capacity of phenanthrene and six heavy metals in a column experiment with unsaturated gravimetric water flow lasting for 3 weeks. The results suggest that biochar as a component in green roof substrates perform better than traditional materials, concerning retention of the tested pollutants, and that different types of biochar have different properties in this respect.

Comparison of Filters for Concentrating Microbial Indicators and Pathogens in Lake Water Samples

PubMed Central

Stelzer, Erin A.; Brady, Amie M. G.; Huitger, Carrie; Bushon, Rebecca N.; Ip, Hon S.; Ware, Michael W.; Villegas, Eric N.; Gallardo, Vicente; Lindquist, H. D. Alan

2013-01-01

Bacterial indicators are used to indicate increased health risk from pathogens and to make beach closure and advisory decisions; however, beaches are seldom monitored for the pathogens themselves. Studies of sources and types of pathogens at beaches are needed to improve estimates of swimming-associated health risks. It would be advantageous and cost-effective, especially for studies conducted on a regional scale, to use a method that can simultaneously filter and concentrate all classes of pathogens from the large volumes of water needed to detect pathogens. In seven recovery experiments, stock cultures of viruses and protozoa were seeded into 10-liter lake water samples, and concentrations of naturally occurring bacterial indicators were used to determine recoveries. For the five filtration methods tested, the highest median recoveries were as follows: glass wool for adenovirus (4.7%); NanoCeram for enterovirus (14.5%) and MS2 coliphage (84%); continuous-flow centrifugation (CFC) plus Virocap (CFC+ViroCap) for Escherichia coli (68.3%) and Cryptosporidium (54%); automatic ultrafiltration (UF) for norovirus GII (2.4%); and dead-end UF for Enterococcus faecalis (80.5%), avian influenza virus (0.02%), and Giardia (57%). In evaluating filter performance in terms of both recovery and variability, the automatic UF resulted in the highest recovery while maintaining low variability for all nine microorganisms. The automatic UF was used to demonstrate that filtration can be scaled up to field deployment and the collection of 200-liter lake water samples. PMID:23263948

Rare earth elements in river waters

NASA Technical Reports Server (NTRS)

Goldstein, Steven J.; Jacobsen, Stein B.

1988-01-01

To characterize the input to the oceans of rare earth elements (REE) in the dissolved and the suspended loads of rivers, the REE concentrations were measured in samples of Amazon, Indus, Mississippi, Murray-Darling, and Ohio rivers and in samples of smaller rivers that had more distinct drainage basin lithology and water chemistry. It was found that, in the suspended loads of small rivers, the REE pattern was dependent on drainage basin geology, whereas the suspended loads in major rivers had relatively uniform REE patterns and were heavy-REE depleted relative to the North American Shale composite (NASC). The dissolved loads in the five major rivers had marked relative heavy-REE enrichments, relative to the NASC and the suspended material, with the (La/Yb)N ratio of about 0.4 (as compared with the ratio of about 1.9 in suspended loads).

Earth - Moon Conjunction

NASA Technical Reports Server (NTRS)

1992-01-01

On December 16, 1992, 8 days after its encounter with Earth, the Galileo spacecraft looked back from a distance of about 6.2 million kilometers (3.9 million miles) to capture this remarkable view of the Moon in orbit about Earth. The composite photograph was constructed from images taken through visible (violet, red) and near-infrared (1.0-micron) filters. The Moon is in the foreground; its orbital path is from left to right. Brightly colored Earth contrasts strongly with the Moon, which reacts only about one-third as much sunlight as our world. To improve the visibility of both bodies, contrast and color have been computer enhanced. At the bottom of Earth's disk, Antarctica is visible through clouds. The Moon's far side can also be seen. The shadowy indentation in the Moon's dawn terminator--the boundary between its dark and lit sides--is the South Pole-Aitken Basin, one of the largest and oldest lunar impact features. This feature was studied extensively by Galileo during the first Earth flyby in December 1990.

Silver migration from silver-modified activated carbon applied as a water filtration medium in classic cartridges of jug filter systems.

PubMed

Garboś, S; Swięcicka, D

2012-01-01

A comprehensive study was undertaken in order to examine the possible adverse effect of jug filter systems (JFSs) on the quality of filtered water taking into account the released amounts of silver (Ag) into the filtered test water. Nine brands of JFSs (A-I) were investigated according to BS 8427:2004 using a validated ICP/MS method. Essential modification of BS 8427:2004 within the domain of the composite sample preparation was proposed and applied during the tests. The established grand mean concentrations of released Ag from A-H classic cartridges (containing Ag-modified activated carbon and ion exchange resins) and I classic cartridge (containing non-modified activated carbon and ion exchange resin) installed in corresponding JFSs were in the range of 2.6-13.1 µg l⁻¹ and lower than 0.014 µg l⁻¹, respectively. These values were applied for the estimation of the daily intakes of Ag connected with the consumption of water filtered using JFSs (ranging from < 0.0004 to 0.374 µg kg⁻¹ day⁻¹). After taking into account the grand mean concentrations of Ag established during the whole cycle of exploitation for nine JFSs and on the basis of available toxicological data for this element, no long-term risk for human health with respect to appearance of argyria (a condition caused by improper exposure to the Ag or Ag compounds) could be expected (the Hazard Quotient indices estimated as ratios of the daily intakes to the reference dose of Ag were equal or lower than 0.075). Ag-modified activated carbon is not included in the positive list of the authorised substances of the European Commission Regulation (EU) No. 10/2011. Additionally, this material has not been approved by European Food Safety Authority (EFSA). A part of water filtered by JFSs can be directly consumed as drinking water and additionally the remaining water can be applied for the preparation of food products (drinks, soups, etc.). In both cases the quality of water has to fulfil

Evaluation of the impact of the plastic BioSand filter on health and drinking water quality in rural Tamale, Ghana.

PubMed

Stauber, Christine E; Kominek, Byron; Liang, Kaida R; Osman, Mumuni K; Sobsey, Mark D

2012-10-24

A randomized controlled trial of the plastic BioSand filter (BSF) was performed in rural communities in Tamale (Ghana) to assess reductions in diarrheal disease and improvements in household drinking water quality. Few studies of household water filters have been performed in this region, where high drinking water turbidity can be a challenge for other household water treatment technologies. During the study, the longitudinal prevalence ratio for diarrhea comparing households that received the plastic BSF to households that did not receive it was 0.41 (95% confidence interval: 0.18, 0.92), suggesting an overall diarrheal disease reduction of 59% [corrected]. The plastic BSF achieved a geometric mean reduction of 97% and 67% for E. coli and turbidity, respectively. These results suggest the plastic BSF significantly improved drinking water quality and reduced diarrheal disease during the short trial in rural Tamale, Ghana. The results are similar to other trials of household drinking water treatment technologies.

Evaluation of the Impact of the Plastic BioSand Filter on Health and Drinking Water Quality in Rural Tamale, Ghana

PubMed Central

Stauber, Christine E.; Kominek, Byron; Liang, Kaida R.; Osman, Mumuni K.; Sobsey, Mark D.

2012-01-01

A randomized controlled trial of the plastic BioSand filter (BSF) was performed in rural communities in Tamale (Ghana) to assess reductions in diarrheal disease and improvements in household drinking water quality. Few studies of household water filters have been performed in this region, where high drinking water turbidity can be a challenge for other household water treatment technologies. During the study, the longitudinal prevalence ratio for diarrhea comparing households that received the plastic BSF to households that did not receive it was 0.40 (95% confidence interval: 0.05, 0.80), suggesting an overall diarrheal disease reduction of 60%. The plastic BSF achieved a geometric mean reduction of 97% and 67% for E. coli and turbidity, respectively. These results suggest the plastic BSF significantly improved drinking water quality and reduced diarrheal disease during the short trial in rural Tamale, Ghana. The results are similar to other trials of household drinking water treatment technologies. PMID:23202818

Space-Confined Earth-Abundant Bifunctional Electrocatalyst for High-Efficiency Water Splitting.

PubMed

Tang, Yanqun; Fang, Xiaoyu; Zhang, Xin; Fernandes, Gina; Yan, Yong; Yan, Dongpeng; Xiang, Xu; He, Jing

2017-10-25

Hydrogen generation from water splitting could be an alternative way to meet increasing energy demands while also balancing the impact of energy being supplied by fossil-based fuels. The efficacy of water splitting strongly depends on the performance of electrocatalysts. Herein, we report a unique space-confined earth-abundant electrocatalyst having the bifunctionality of simultaneous hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), leading to high-efficiency water splitting. Outperforming Pt/C or RuO 2 catalysts, this mesoscopic, space-confined, bifunctional configuration is constructed from a monolithic zeolitic imidazolate framework@layered double hydroxide (ZIF@LDH) precursor on Ni foam. Such a confinement leads to a high dispersion of ultrafine Co 3 O 4 nanoparticles within the N-doped carbon matrix by temperature-dependent calcination of the ZIF@LDH. We demonstrate that the OER has an overpotential of 318 mV at a current density of 10 mA cm -2 , while that of HER is -106 mV @ -10 mA cm -2 . The voltage applied to a two-electrode cell for overall water splitting is 1.59 V to achieve a stable current density of 10 mA cm -2 while using the monolithic catalyst as both the anode and the cathode. It is anticipated that our space-confined method, which focuses on earth-abundant elements with structural integrity, may provide a novel and economically sound strategy for practical energy conversion applications.

A cluster randomized controlled trial to reduce childhood diarrhea using hollow fiber water filter and/or hygiene-sanitation educational interventions.

PubMed

Lindquist, Erik D; George, C M; Perin, Jamie; Neiswender de Calani, Karen J; Norman, W Ray; Davis, Thomas P; Perry, Henry

2014-07-01

Safe domestic potable water supplies are urgently needed to reduce childhood diarrheal disease. In periurban neighborhoods in Cochabamba, Bolivia, we conducted a cluster randomized controlled trial to evaluate the efficacy of a household-level hollow fiber filter and/or behavior change communication (BCC) on water, sanitation, and hygiene (WASH) to reduce the diarrheal disease in children less than 5 years of age. In total, 952 households were followed for a period of 12 weeks post-distribution of the study interventions. Households using Sawyer PointONE filters had significantly less diarrheal disease compared with the control arm during the intervention period, which was shown by diarrheal prevalence ratios of 0.21 (95% confidence interval [95% CI] = 0.15-0.30) for the filter arm and 0.27 (95% CI = 0.22-0.34) for the filter and WASH BCC arm. A non-significant reduction in diarrhea prevalence was reported in the WASH BCC study arm households (0.71, 95% CI = 0.59-0.86). © The American Society of Tropical Medicine and Hygiene.

A Cluster Randomized Controlled Trial to Reduce Childhood Diarrhea Using Hollow Fiber Water Filter and/or Hygiene–Sanitation Educational Interventions

PubMed Central

Lindquist, Erik D.; George, C. M.; Perin, Jamie; Neiswender de Calani, Karen J.; Norman, W. Ray; Davis, Thomas P.; Perry, Henry

2014-01-01

Safe domestic potable water supplies are urgently needed to reduce childhood diarrheal disease. In periurban neighborhoods in Cochabamba, Bolivia, we conducted a cluster randomized controlled trial to evaluate the efficacy of a household-level hollow fiber filter and/or behavior change communication (BCC) on water, sanitation, and hygiene (WASH) to reduce the diarrheal disease in children less than 5 years of age. In total, 952 households were followed for a period of 12 weeks post-distribution of the study interventions. Households using Sawyer PointONE filters had significantly less diarrheal disease compared with the control arm during the intervention period, which was shown by diarrheal prevalence ratios of 0.21 (95% confidence interval [95% CI] = 0.15–0.30) for the filter arm and 0.27 (95% CI = 0.22–0.34) for the filter and WASH BCC arm. A non-significant reduction in diarrhea prevalence was reported in the WASH BCC study arm households (0.71, 95% CI = 0.59–0.86). PMID:24865680

Academic Interface at the New University of Florida Water Reclamation Facility

DTIC Science & Technology

1992-05-01

of polymer solutions at viscosities up to carbon, 1.1 lb per gallon of water, diatomaceous earth , 5500 cp at 195 spin. or to 10.000 cps at 114 spin...does not contain this upper sand distribution cone. The physical process of the DynaSand® filter of adsorbing suspended solids onto a granular medium

Activated-charcoal filters: water treatment, pollution control, and industrial applications. January 1970-July 1988 (citations from the US Patent data base). Report for January 1970-July 1988

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This bibliography contains citations of selected patents concerning activated-charcoal filters and their applications in water treatment, pollution control, and industrial processes. Filtering methods and equipment for air and water purification, industrial distillation and extraction, industrial leaching, and filtration of toxic gases and pollutants are described. Applications include drinking water purification, filtering beverages, production of polymer materials, solvent and metal recovery, swimming pool filtration, waste conversion, automobile fuel and exhaust systems, and footwear deodorizing. (Contains 129 citations fully indexed and including a title list.)

The magnetodynamic filters in monitoring the contaminants from polluted water systems (abstract)

NASA Astrophysics Data System (ADS)

Swarup, R.; Singh, Bharat

1994-05-01

The magnetic interaction seems to influence the ``structural memory'' of water systems which is quenched in ideally pure water. The sedentary lifetime of each water molecule is extremely short (10-10 s) and its molecular structures may be influenced by some physical effect like magnetic field treatment, it's space time gradients, water velocity, pressure drop, etc. in the interpolar space, so as to yield a noticeable temporal magnetopotential development characterizing the properties of homogeneous and heterogeneous water systems. This principle is also extended to prevailing water systems which always contain various impurities, gas, molecules, ions, microscopic particles in random order. Still the existence of structural memory may be verified by reliable experimental data. The magnetopotential curves of different water systems depict the design and develop-software package for constructing the magnetodynamic-filters superior to the existing techniques on pollution studies like remote sensing, muon spin resonance, laser spectroscopy, nuclear techniques, the gamma ray peak efficiency method, trace elemental characterization due to NBS, neutron activation analysis, and graphite furnance atomic absorption spectrometer. The physiochemical characteristics of water calibrated in terms of magnetopotential curves change with the removal of dissolved gasses, impurities, thermal activation, etc. and the algae, bacteria, phosphates, etc. have been removed at a rapid rate. The magnetodynamic study of ganga water proves it to be an extremely pure and highly resourced fluid.

International Space Station (ISS) Bacterial Filter Elements (BFEs): Filter Efficiency and Pressure Testing of Returned Units

NASA Technical Reports Server (NTRS)

Green, Robert D.; Agui, Juan H.; Vijayakumar, R.

2017-01-01

The air revitalization system aboard the International Space Station (ISS) provides the vital function of maintaining a clean cabin environment for the crew and the hardware. This becomes a serious challenge in pressurized space compartments since no outside air ventilation is possible, and a larger particulate load is imposed on the filtration system due to lack of sedimentation due to the microgravity environment in Low Earth Orbit (LEO). The ISS Environmental Control and Life Support (ECLS) system architecture in the U.S. Segment uses a distributed particulate filtration approach consisting of traditional High-Efficiency Particulate Adsorption (HEPA) media filters deployed at multiple locations in each U.S. Segment module; these filters are referred to as Bacterial Filter Elements, or BFEs. These filters see a replacement interval, as part of maintenance, of 2-5 years dependent on location in the ISS. In this work, we present particulate removal efficiency, pressure drop, and leak test results for a sample set of 8 BFEs returned from the ISS after filter replacement. The results can potentially be utilized by the ISS Program to ascertain whether the present replacement interval can be maintained or extended to balance the on-ground filter inventory with extension of the lifetime of ISS beyond 2024. These results can also provide meaningful guidance for particulate filter designs under consideration for future deep space exploration missions.

Rare Earth Optical Temperature Sensor

NASA Technical Reports Server (NTRS)

Chubb, Donald L. (Inventor); Jenkins, Phillip (Inventor)

2004-01-01

A rare earth optical temperature sensor is disclosed for measuring high temperatures. Optical temperature sensors exist that channel emissions from a sensor to a detector using a light pipe. The invention uses a rare earth emitter to transform the sensed thermal energy into a narrow band width optical signal that travels to a detector using a light pipe. An optical bandpass filter at the detector removes any noise signal outside of the band width of the signal from the emitter.

RADIUM REMOVAL FROM WATER MANGANESE DIOXIDE ADSORP- TION AND DIATOMACEOUS EARTH FILTRATION

EPA Science Inventory

The study reveals that radium adsorption onto precipitated MnO2 followed by diatomaceous earth (DE) filtration is a very effective treatment process for radium-contaminated water. Radium removals in the range of 80% to 97% were observed for performed MnO2 feed concentrations of 0...

Near real-time qualitative monitoring of lake water chlorophyll globally using GoogleEarth Engine

NASA Astrophysics Data System (ADS)

Zlinszky, András; Supan, Peter; Koma, Zsófia

2017-04-01

Monitoring ocean chlorophyll and suspended sediment has been made possible using optical satellite imaging, and has contributed immensely to our understanding of the Earth and its climate. However, lake water quality monitoring has limitations due to the optical complexity of shallow, sediment- and organic matter-laden waters. Meanwhile, timely and detailed information on basic lake water quality parameters would be essential for sustainable management of inland waters. Satellite-based remote sensing can deliver area-covering, high resolution maps of basic lake water quality parameters, but scientific application of these datasets for lake monitoring has been hindered by limitations to calibration and accuracy evaluation, and therefore access to such data has been the privilege of scientific users. Nevertheless, since for many inland waters satellite imaging is the only source of monitoring data, we believe it is urgent to make map products of chlorophyll and suspended sediment concentrations available to a wide range of users. Even if absolute accuracy can not be validated, patterns, processes and qualitative information delivered by such datasets in near-real time can act as an early warning system, raise awareness to water quality processes and serve education, in addition to complementing local monitoring activities. By making these datasets openly available on the internet through an easy to use framework, dialogue between stakeholders, management and governance authorities can be facilitated. We use GoogleEarthEngine to access and process archive and current satellite data. GoogleEarth Engine is a development and visualization framework that provides access to satellite datasets and processing capacity for analysis at the Petabyte scale. Based on earlier investigations, we chose the fluorescence line height index to represent water chlorophyll concentration. This index relies on the chlorophyll fluorescence peak at 680 nm, and has been tested for open ocean

Global Temperature Measurement of Supercooled Water under Icing Conditions using Two-Color Luminescent Images and Multi-Band Filter

NASA Astrophysics Data System (ADS)

Tanaka, Mio; Morita, Katsuaki; Kimura, Shigeo; Sakaue, Hirotaka

2012-11-01

Icing occurs by a collision of a supercooled-water droplet on a surface. It can be seen in any cold area. A great attention is paid in an aircraft icing. To understand the icing process on an aircraft, it is necessary to give the temperature information of the supercooled water. A conventional technique, such as a thermocouple, is not valid, because it becomes a collision surface that accumulates ice. We introduce a dual-luminescent imaging to capture a global temperature distribution of supercooled water under the icing conditions. It consists of two-color luminescent probes and a multi-band filter. One of the probes is sensitive to the temperature and the other is independent of the temperature. The latter is used to cancel the temperature-independent luminescence of a temperature-dependent image caused by an uneven illumination and a camera location. The multi-band filter only selects the luminescent peaks of the probes to enhance the temperature sensitivity of the imaging system. By applying the system, the time-resolved temperature information of a supercooled-water droplet is captured.

Controlled laboratory experiments and modeling of vegetative filter strips with shallow water tables

NASA Astrophysics Data System (ADS)

Fox, Garey A.; Muñoz-Carpena, Rafael; Purvis, Rebecca A.

2018-01-01

Natural or planted vegetation at the edge of fields or adjacent to streams, also known as vegetative filter strips (VFS), are commonly used as an environmental mitigation practice for runoff pollution and agrochemical spray drift. The VFS position in lowlands near water bodies often implies the presence of a seasonal shallow water table (WT). In spite of its potential importance, there is limited experimental work that systematically studies the effect of shallow WTs on VFS efficacy. Previous research recently coupled a new physically based algorithm describing infiltration into soils bounded by a water table into the VFS numerical overland flow and transport model, VFSMOD, to simulate VFS dynamics under shallow WT conditions. In this study, we tested the performance of the model against laboratory mesoscale data under controlled conditions. A laboratory soil box (1.0 m wide, 2.0 m long, and 0.7 m deep) was used to simulate a VFS and quantify the influence of shallow WTs on runoff. Experiments included planted Bermuda grass on repacked silt loam and sandy loam soils. A series of experiments were performed including a free drainage case (no WT) and a static shallow water table (0.3-0.4 m below ground surface). For each soil type, this research first calibrated VFSMOD to the observed outflow hydrograph for the free drainage experiments to parameterize the soil hydraulic and vegetation parameters, and then evaluated the model based on outflow hydrographs for the shallow WT experiments. This research used several statistical metrics and a new approach based on hypothesis testing of the Nash-Sutcliffe model efficiency coefficient (NSE) to evaluate model performance. The new VFSMOD routines successfully simulated the outflow hydrographs under both free drainage and shallow WT conditions. Statistical metrics considered the model performance valid with greater than 99.5% probability across all scenarios. This research also simulated the shallow water table experiments with

Electrocatalytic water treatment using carbon nanotube filters modified with metal oxides.

PubMed

Yang, So Young; Vecitis, Chad D; Park, Hyunwoong

2017-01-28

This study examined the electrocatalytic activity of multi-walled carbon nanotube (CNT) filters for remediation of aqueous phenol in a sodium sulfate electrolyte. CNT filters were loaded with antimony-doped tin oxide (Sb-SnO 2 ; SS) and bismuth- and antimony-codoped tin oxide (Bi-Sb-SnO 2 ; BSS) via electrosorption at 2 V for 1 h and then assembled into a flow-through batch reactor as anode-cathode couples with perforated titanium foils. The as-synthesized pristine CNT filters were composed of 50-60-nm-thick tubular carbons with smooth surfaces, whereas the tubes composing the SS-CNT and BSS-CNT filters were slightly thicker and bumpy, because they were coated with SS and BSS particles ~50 nm in size. Electrochemical characterization of the samples indicated a positive shift in the onset potential and a decrease in the current magnitude in the modified CNT filters due to passivation and oxidation inhibition of the bare CNT filters. These filters exhibited a similar adsorption capacity for phenol (5-8%), whereas loadings of SS and BSS enhanced the degradation rate of phenol by ~1.5 and 2.1 times, respectively. In particular, the total organic carbon removal performance and mineralization efficiency of the BSS-CNT filters were approximately twice those of the bare CNT filters. The BSS-CNT filters also exhibited an enhanced oxidation of ferrocyanide [Fe II (CN) 6 4- ], which was not adsorbed onto the CNT filters. The enhanced electrocatalytic performance of the modified CNT filters was attributed to an effective generation of OH radicals. The surfaces of the filters were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy.

Reverse Osmosis Filter Use and High Arsenic Levels in Private Well Water

PubMed Central

George, Christine M.; Smith, Allan H.; Kalman, David A.; Steinmaus, Craig M.

2013-01-01

Inorganic arsenic causes cancer, and millions of people worldwide are exposed to arsenic-contaminated water. Regulatory standards for arsenic levels in drinking water generally do not apply to private domestic wells. Reverse osmosis (RO) units commonly are used by well owners to reduce arsenic concentrations, but may not always be effective. In a survey of 102 homes in Nevada, 19 used RO devices. Pre- and post-RO filtration arsenic concentrations averaged 443 μg/l and 87 μg/l, respectively. The average absolute and percent reductions in arsenic concentrations after filtration were 356 μg/l and 79%, respectively. Postfiltration concentrations were higher than 10 μg/l in 10 homes and higher than 100 μg/l in 4 homes. These findings provide evidence that RO filters do not guarantee safe drinking water and, despite regulatory standards, some people continue to be exposed to very high arsenic concentrations. PMID:17867571

Method validation using weighted linear regression models for quantification of UV filters in water samples.

PubMed

da Silva, Claudia Pereira; Emídio, Elissandro Soares; de Marchi, Mary Rosa Rodrigues

2015-01-01

This paper describes the validation of a method consisting of solid-phase extraction followed by gas chromatography-tandem mass spectrometry for the analysis of the ultraviolet (UV) filters benzophenone-3, ethylhexyl salicylate, ethylhexyl methoxycinnamate and octocrylene. The method validation criteria included evaluation of selectivity, analytical curve, trueness, precision, limits of detection and limits of quantification. The non-weighted linear regression model has traditionally been used for calibration, but it is not necessarily the optimal model in all cases. Because the assumption of homoscedasticity was not met for the analytical data in this work, a weighted least squares linear regression was used for the calibration method. The evaluated analytical parameters were satisfactory for the analytes and showed recoveries at four fortification levels between 62% and 107%, with relative standard deviations less than 14%. The detection limits ranged from 7.6 to 24.1 ng L(-1). The proposed method was used to determine the amount of UV filters in water samples from water treatment plants in Araraquara and Jau in São Paulo, Brazil. Copyright © 2014 Elsevier B.V. All rights reserved.

Biological filters and their use in potable water filtration systems in spaceflight conditions.

PubMed

Thornhill, Starla G; Kumar, Manish

2018-05-01

Providing drinking water to space missions such as the International Space Station (ISS) is a costly requirement for human habitation. To limit the costs of water transport, wastewater is collected and purified using a variety of physical and chemical means. To date, sand-based biofilters have been designed to function against gravity, and biofilms have been shown to form in microgravity conditions. Development of a universal silver-recycling biological filter system that is able to function in both microgravity and full gravity conditions would reduce the costs incurred in removing organic contaminants from wastewater by limiting the energy and chemical inputs required. This paper aims to propose the use of a sand-substrate biofilter to replace chemical means of water purification on manned spaceflights. Copyright © 2018 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

In situ fabrication of depth-type hierarchical CNT/quartz fiber filters for high efficiency filtration of sub-micron aerosols and high water repellency

NASA Astrophysics Data System (ADS)

Li, Peng; Zong, Yichen; Zhang, Yingying; Yang, Mengmeng; Zhang, Rufan; Li, Shuiqing; Wei, Fei

2013-03-01

We fabricated depth-type hierarchical CNT/quartz fiber (QF) filters through in situ growth of CNTs upon quartz fiber (QF) filters using a floating catalyst chemical vapor deposition (CVD) method. The filter specific area of the CNT/QF filters is more than 12 times higher than that of the pristine QF filters. As a result, the penetration of sub-micron aerosols for CNT/QF filters is reduced by two orders of magnitude, which reaches the standard of high-efficiency particulate air (HEPA) filters. Simultaneously, due to the fluffy brush-like hierarchical structure of CNTs on QFs, the pore size of the hybrid filters only has a small increment. The pressure drop across the CNT/QF filters only increases about 50% with respect to that of the pristine QF filters, leading to an obvious increased quality factor of the CNT/QF filters. Scanning electron microscope images reveal that CNTs are very efficient in capturing sub-micron aerosols. Moreover, the CNT/QF filters show high water repellency, implying their superiority for applications in humid conditions.We fabricated depth-type hierarchical CNT/quartz fiber (QF) filters through in situ growth of CNTs upon quartz fiber (QF) filters using a floating catalyst chemical vapor deposition (CVD) method. The filter specific area of the CNT/QF filters is more than 12 times higher than that of the pristine QF filters. As a result, the penetration of sub-micron aerosols for CNT/QF filters is reduced by two orders of magnitude, which reaches the standard of high-efficiency particulate air (HEPA) filters. Simultaneously, due to the fluffy brush-like hierarchical structure of CNTs on QFs, the pore size of the hybrid filters only has a small increment. The pressure drop across the CNT/QF filters only increases about 50% with respect to that of the pristine QF filters, leading to an obvious increased quality factor of the CNT/QF filters. Scanning electron microscope images reveal that CNTs are very efficient in capturing sub-micron aerosols

Computer simulation results of attitude estimation of earth orbiting satellites

NASA Technical Reports Server (NTRS)

Kou, S. R.

1976-01-01

Computer simulation results of attitude estimation of Earth-orbiting satellites (including Space Telescope) subjected to environmental disturbances and noises are presented. Decomposed linear recursive filter and Kalman filter were used as estimation tools. Six programs were developed for this simulation, and all were written in the basic language and were run on HP 9830A and HP 9866A computers. Simulation results show that a decomposed linear recursive filter is accurate in estimation and fast in response time. Furthermore, for higher order systems, this filter has computational advantages (i.e., less integration errors and roundoff errors) over a Kalman filter.

Monitoring of the Earth's surface deformation in the area of water dam Zarnowiec

NASA Astrophysics Data System (ADS)

Mojzes, Marcel; Wozniak, Marek; Habel, Branislav; Macak, Marek

2017-04-01

Mathematical and physical research directly motivates geodetic community which can provide very accurate measurements for testing of the proposed models Earth's surface motion near the water dams should be monitored due to the security of the area. This is a process which includes testing of existing models and their physical parameters. Change of the models can improve the practical results for analyzing the trends of motion in the area of upper reservoir of water dam Zarnowiec. Since 1998 Warsaw University of Technology realized a research focused on the horizontal displacements of the upper reservoir of water dam Zarnowiec. The 15 selected control points located on the upper reservoir crown of the water dam were monitored by classical distance measurements. It was found out that changes in the object's geometry occur due to the variation of the water level. The control measurements of the changes in the object's geometry occurring during the process of emptying and filling of the upper reservoir of water dam were compared with the deformations computed using improved Boussinesqués method programmed in the software MATLAB and ANSYS for elastic and isotropic half space as derivation of suitable potentials extended to the loaded region. The details and numerical results of this process are presented This presentation was prepared within the project "National Centre for Diagnostic of the Earth's Surface Deformations in the Area of Slovakia", ITMS code: 26220220108.

Coliform species recovered from untreated surface water and drinking water by the membrane filter, standard, and modified most-probable-number techniques.

PubMed Central

Evans, T M; LeChevallier, M W; Waarvick, C E; Seidler, R J

1981-01-01

The species of total coliform bacteria isolated from drinking water and untreated surface water by the membrane filter (MF), the standard most-probable-number (S-MPN), and modified most-probable-number (M-MPN) techniques were compared. Each coliform detection technique selected for a different profile of coliform species from both types of water samples. The MF technique indicated that Citrobacter freundii was the most common coliform species in water samples. However, the fermentation tube techniques displayed selectivity towards the isolation of Escherichia coli and Klebsiella. The M-MPN technique selected for more C. freundii and Enterobacter spp. from untreated surface water samples and for more Enterobacter and Klebsiella spp. from drinking water samples than did the S-MPN technique. The lack of agreement between the number of coliforms detected in a water sample by the S-MPN, M-MPN, and MF techniques was a result of the selection for different coliform species by the various techniques. PMID:7013706

SPE (tm) water electrolyzers in support of mission from planet Earth

NASA Technical Reports Server (NTRS)

Mcelroy, J. F.

1991-01-01

During the 1970's, the Solid Polymer Electrolyte (SPE) water electrolyzer, which uses ion exchange membranes as its sole electrolyte, was developed for nuclear submarine metabolic oxygen production. SPE water electrolyzer developments included operation at up to 3,000 psia and at current densities in excess of 1,000 amps per square foot. The SPE water electrolyzer system has accumulated tens of thousands of system hours with the Navies of both the United States and the United Kingdom. During the 1980's, the basic SPE water electrolyzer cell structure developed for the Navies was incorporated into several demonstrators for NASA's Space Station Program. Among these were: (1) the SPE regenerative fuel cell for electrical energy storage; (2) the SPE water electrolyzer for metabolic oxygen production; and (3) the high pressure SPE water electrolyzer for reboost propellant production. In the 1990's, emphasis will be the development of SPE water electrolyzers for Mission from Planet Earth. Currently defined potential applications for the SPE water electrolyzer include: (1) SPE water electrolyzers operating at high pressure as part of a regenerative fuel cell extraterrestrial surface energy storage system; (2) SPE water electrolyzers for propellant production from extraterrestrial indigenous materials; and (3) SPE water electrolyzers for metabolic oxygen and potable water production from reclaimed water.

BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING SOUTH. THE ...

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

BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING SOUTH. THE OUTSIDE FACE OF THE NORTH WALL OF SETTLING RESERVOIR NO. 3 IS SEEN AT THE RIGHT. THE SETTLING RESERVOIR IS ELEVATED ABOVE THE FILTERING RESERVOIR TO ACHIEVE GRAVITY WATER FLOW FROM THE SETTLING RESERVOIR INTO THE FILTERING RESERVOIR. - Yuma Main Street Water Treatment Plant, Blaisdell Slow Sand Filter Washing Machine, Jones Street at foot of Main Street, Yuma, Yuma County, AZ

NASA's mission to planet Earth: Earth observing system

NASA Technical Reports Server (NTRS)

1993-01-01

The topics covered include the following: global climate change; radiation, clouds, and atmospheric water; the ocean; the troposphere - greenhouse gases; land cover and the water cycle; polar ice sheets and sea level; the stratosphere - ozone chemistry; volcanoes; the Earth Observing System (EOS) - how NASA will support studies of global climate change?; research and assessment - EOS Science Investigations; EOS Data and Information System (EOSDIS); EOS observations - instruments and spacecraft; a national international effort; and understanding the Earth System.

Characterization of soluble microbial products in a drinking water biological aerated filter.

PubMed

Kang, Jia; Ma, Teng-Fei; Zhang, Peng; Gao, Xu; Chen, You-Peng

2016-05-01

Utilization-associated products (UAPs) and biomass-associated products (BAPs) were quantified separately in this study to characterize soluble microbial products (SMPs) in a drinking water lab-scale biological aerated filter (BAF), and their basic characteristics were explored using gel filtration chromatography and three-dimensional excitation-emission matrix (3D-EEM) spectrophotometry with fluorescence regional integration analysis and parallel factor model. UAPs were observed increased with the increase of filter media depth and accumulated after BAF treatment, whereas BAPs were basically constant. 3D-EEM spectroscopy analysis result showed that tryptophan and protein-like compounds were the main components of UAPs and BAPs, and fulvic-acid-like substance was a major component of BAPs, rather than UAPs. In terms of molecular weight (MW) distribution, UAP MW presented a bimodal distribution in the range of 1-5 and >10 kDa, while BAP MW exhibited unimodal distribution with MW >20 kDa fraction accounting for more than 90 %. The macromolecules of UAPs accumulated after BAF treatment. This study provides theoretical support for in-depth study of SMP characteristics.

Storm Water Pollution Removal Performance of Compost Filter Socks

USDA-ARS?s Scientific Manuscript database

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

Media filter drain : modified design evaluation.

DOT National Transportation Integrated Search

2014-09-01

The media filter drain (MFD), a stormwater water quality treatment best management practice, consists of media made up of : aggregate, perlite, gypsum and dolomite in a trench located along roadway shoulders with gravel and vegetative pre-filtering f...

Modeling of two-dimensional overland flow in a vegetative filter

Treesearch

Matthew J. Helmers; Dean E. Eisenhauer; Thomas G. Franti; Michael G. Dosskey

2002-01-01

Water transports sediment and other pollutants through vegetative filters. It is often assumed that the overland flow is uniformly distributed across the vegetative filter, but this research indicates otherwise. The objective of this study was to model the two-dimensional overland water flow through a vegetative filter, accounting for variation in microtopography,...

Removals of cryptosporidium parvum oocysts and cryptosporidium-sized polystyrene microspheres from swimming pool water by diatomaceous earth filtration and perlite-sand filtration.

PubMed

Lu, Ping; Amburgey, James E; Hill, Vincent R; Murphy, Jennifer L; Schneeberger, Chandra L; Arrowood, Michael J; Yuan, Tao

2017-06-01

Removal of Cryptosporidium-sized microspheres and Cryptosporidium parvum oocysts from swimming pools was investigated using diatomaceous earth (DE) precoat filtration and perlite-sand filtration. In pilot-scale experiments, microsphere removals of up to 2 log were obtained with 0.7 kg·DE/m 2 at a filtration rate of 5 m/h. A slightly higher microsphere removal (2.3 log) was obtained for these DE-precoated filters when the filtration rate was 3.6 m/h. Additionally, pilot-scale perlite-sand filters achieved greater than 2 log removal when at least 0.37 kg/m 2 of perlite was used compared to 0.1-0.4 log removal without perlite both at a surface loading rate of 37 m/h. Full-scale testing achieved 2.7 log of microspheres and oocysts removal when 0.7 kg·DE/m 2 was used at 3.6 m/h. Removals were significantly decreased by a 15-minute interruption of the flow (without any mechanical agitation) to the DE filter in pilot-scale studies, which was not observed in full-scale filters. Microsphere removals were 2.7 log by perlite-sand filtration in a full-scale swimming pool filter operated at 34 m/h with 0.5 kg/m 2 of perlite. The results demonstrate that either a DE precoat filter or a perlite-sand filter can improve the efficiency of removal of microspheres and oocysts from swimming pools over a standard sand filter under the conditions studied.

Water-induced convection in the Earth's mantle transition zone

NASA Astrophysics Data System (ADS)

Richard, Guillaume C.; Bercovici, David

2009-01-01

Water enters the Earth's mantle by subduction of oceanic lithosphere. Most of this water immediately returns to the atmosphere through arc volcanism, but a part of it is expected as deep as the mantle transition zone (410-660 km depth). There, slabs can be deflected and linger before sinking into the lower mantle. Because it lowers the density and viscosity of the transition zone minerals (i.e., wadsleyite and ringwoodite), water is likely to affect the dynamics of the transition zone mantle overlying stagnant slabs. The consequences of water exchange between a floating slab and the transition zone are investigated. In particular, we focus on the possible onset of small-scale convection despite the adverse thermal gradient (i.e., mantle is cooled from below by the slab). The competition between thermal and hydrous effects on the density and thus on the convective stability of the top layer of the slab is examined numerically, including water-dependent density and viscosity and temperature-dependent water solubility. For plausible initial water content in a slab (≥0.5 wt %), an episode of convection is likely to occur after a relatively short time delay (5-20 Ma) after the slab enters the transition zone. However, water induced rheological weakening is seen to be a controlling parameter for the onset time of convection. Moreover, small-scale convection above a stagnant slab greatly enhances the rate of slab dehydration. Small-scale convection also facilitates heating of the slab, which in itself may prolong the residence time of the slab in the transition zone.

Wavelet Filter Banks for Super-Resolution SAR Imaging

NASA Technical Reports Server (NTRS)

Sheybani, Ehsan O.; Deshpande, Manohar; Memarsadeghi, Nargess

2011-01-01

This paper discusses Innovative wavelet-based filter banks designed to enhance the analysis of super resolution Synthetic Aperture Radar (SAR) images using parametric spectral methods and signal classification algorithms, SAR finds applications In many of NASA's earth science fields such as deformation, ecosystem structure, and dynamics of Ice, snow and cold land processes, and surface water and ocean topography. Traditionally, standard methods such as Fast-Fourier Transform (FFT) and Inverse Fast-Fourier Transform (IFFT) have been used to extract Images from SAR radar data, Due to non-parametric features of these methods and their resolution limitations and observation time dependence, use of spectral estimation and signal pre- and post-processing techniques based on wavelets to process SAR radar data has been proposed. Multi-resolution wavelet transforms and advanced spectral estimation techniques have proven to offer efficient solutions to this problem.

Initial flight results of the TRMM Kalman filter

NASA Technical Reports Server (NTRS)

Andrews, Stephen F.; Morgenstern, Wendy M.

1998-01-01

The Tropical Rainfall Measuring Mission (TRMM) spacecraft is a nadir pointing spacecraft that nominally controls attitude based on the Earth Sensor Assembly (ESA) output. After a potential single point failure in the ESA was identified, the contingency attitude determination method chosen to backup the ESA-based system was a sixth-order extended Kalman filter that uses magnetometer and digital sun sensor measurements. A brief description of the TRMM Kalman filter will be given, including some implementation issues and algorithm heritage. Operational aspects of the Kalman filter and some failure detection and correction will be described. The Kalman filter was tested in a sun pointing attitude and in a nadir pointing attitude during the in-orbit checkout period, and results from those tests will be presented. This paper will describe some lessons learned from the experience of the TRMM team.

Initial Flight Results of the TRMM Kalman Filter

NASA Technical Reports Server (NTRS)

Andrews, Stephen F.; Morgenstern, Wendy M.

1998-01-01

The Tropical Rainfall Measuring Mission (TRMM) spacecraft is a nadir pointing spacecraft that nominally controls attitude based on the Earth Sensor Assembly (ESA) output. After a potential single point failure in the ESA was identified, the contingency attitude determination method chosen to backup the ESA-based system was a sixth-order extended Kalman filter that uses magnetometer and digital sun sensor measurements. A brief description of the TRMM Kalman filter will be given, including some implementation issues and algorithm heritage. Operational aspects of the Kalman filter and some failure detection and correction will be described. The Kalman filter was tested in a sun pointing attitude and in a nadir pointing attitude during the in-orbit checkout period, and results from those tests will be presented. This paper will describe some lessons learned from the experience of the TRMM team.

Technological development of spectral filters for Sentinel-2

NASA Astrophysics Data System (ADS)

Schröter, Karin; Schallenberg, Uwe; Mohaupt, Matthias

2017-11-01

In the frame of the initiative for Global Monitoring for Environment and Security (GMES), jointly undertaken by the European Commission and the European Space Agency a technological development of two filter assemblies was performed for the Multi- Spectral Instrument (MSI) for Sentinel-2. The multispectral pushbroom imaging of the Earth will be performed in 10 VNIR bands (from 443 nm to 945nm) and 3 SWIR bands (from 1375 nm to 2190 nm). Possible filter coating techniques and masking concepts were considered in the frame of trade-off studies. The selected deposition concept is based on self-blocked all-dielectric multilayer band pass filter. Band pass and blocking characteristic is deposited on the space side of a single filter substrate whereas the detector side of the substrate has an antireflective coating. The space- and detector side masking design is realized by blades integrated in the mechanical parts including the mechanical interface to the filter assembly support on the MSI focal plane. The feasibility and required performance of the VNIR Filter Assembly and SWIR Filter Assembly were successfully demonstrated by breadboarding. Extensive performance tests of spectral and optical parameters and environmental tests (radiation, vibration, shock, thermal vacuum cycling, humidity) were performed on filter stripe- and filter assembly level. The presentation will contain a detailed description of the filter assembly design and the results of the performance and environmental tests.

A Method of Effective Quarry Water Purifying Using Artificial Filtering Arrays

NASA Astrophysics Data System (ADS)

Tyulenev, M.; Garina, E.; Khoreshok, A.; Litvin, O.; Litvin, Y.; Maliukhina, E.

2017-01-01

The development of open pit mining in the large coal basins of Russia and other countries increases their negative impact on the environment. Along with the damage of land and air pollution by dust and combustion gases of blasting, coal pits have a significant negative impact on water resources. Polluted quarry water worsens the ecological situation on a much larger area than covered by air pollution and land damage. This significantly worsens the conditions of people living in cities and towns located near the coal pits, and complicates the subsequent restoration of the environment, irreversibly destroying the nature. Therefore, the research of quarry wastewater purifying is becoming an important mater for scholars of technical colleges and universities in the regions with developing open-pit mining. This paper describes the method of determining the basic parameters of the artificial filtering arrays formed on coal pits of Kuzbass (Western Siberia, Russia), and gives recommendations on its application.

Sorption and desorption of arsenic to ferrihydrite in a sand filter.

PubMed

Jessen, Soren; Larsen, Flemming; Koch, Christian Bender; Arvin, Erik

2005-10-15

Elevated arsenic concentrations in drinking water occur in many places around the world. Arsenic is deleterious to humans, and consequently, As water treatment techniques are sought. To optimize arsenic removal, sorption and desorption processes were studied at a drinking water treatment plant with aeration and sand filtration of ferrous iron rich groundwater at Elmevej Water Works, Fensmark, Denmark. Filter sand and pore water were sampled along depth profiles in the filters. The sand was coated with a 100-300 microm thick layer of porous Si-Ca-As-contaning iron oxide (As/Fe = 0.17) with locally some manganese oxide. The iron oxide was identified as a Si-stabilized abiotically formed two-line ferrihydrite with a magnetic hyperfine field of 45.8 T at 5 K. The raw water has an As concentration of 25 microg/L, predominantly as As(II). As the water passes through the filters, As(III) is oxidized to As(V) and the total concentrations drop asymptotically to a approximately 15 microg/L equilibrium concentration. Mn is released to the pore water, indicating the existence of reactive manganese oxides within the oxide coating, which probably play a role for the rapid As(III) oxidation. The As removal in the sand filters appears controlled by sorption equilibrium onto the ferrihydrite. By addition of ferrous chloride (3.65 mg of Fe(II)/L) to the water stream between two serially connected filters, a 3 microg/L As concentration is created in the water that infiltrates into the second sand filter. However, as water flow is reestablished through the second filter, As desorbs from the ferrihydrite and increases until the 15 microg/L equilibrium concentration. Sequential chemical extractions and geometrical estimates of the fraction of surface-associated As suggest that up to 40% of the total As can be remobilized in response to changes in the water chemistry in the sand filter.

Earth as Seen from Mars

NASA Technical Reports Server (NTRS)

2005-01-01

On its 449th martian day, or sol (April 29, 2005), NASA's Mars rover Opportunity woke up approximately an hour after sunset and took this picture of the fading twilight as the stars began to come out. Set against the fading red glow of the sky, the pale dot near the center of the picture is not a star, but a planet -- Earth.

Earth appears elongated because it moved slightly during the 15-second exposures. The faintly blue light from the Earth combines with the reddish sky glow to give the pale white appearance.

The images were taken with Opportunity's panoramic camera, using 440-nanometer, 530-nanometer, and 750-nanometer color filters. In processing on the ground, the images were shifted slightly to compensate for Earth's motion between one image and the next.

Retention of titanium dioxide nanoparticles in biological activated carbon filters for drinking water and the impact on ammonia reduction.

PubMed

Liu, Zhiyuan; Yu, Shuili; Park, Heedeung; Liu, Guicai; Yuan, Qingbin

2016-06-01

Given the increasing discoveries related to the eco-toxicity of titanium dioxide (TiO2) nanoparticles (NPs) in different ecosystems and with respect to public health, it is important to understand their potential effects in drinking water treatment (DWT). The effects of TiO2 NPs on ammonia reduction, ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in biological activated carbon (BAC) filters for drinking water were investigated in static and dynamic states. In the static state, both the nitrification potential and AOB were significantly inhibited by 100 μg L(-1) TiO2 NPs after 12 h (p < 0.05), and the threshold decreased to 10 μg L(-1) with prolonged exposure (36 h, p < 0.05). However, AOA were not considerably affected in any of the tested conditions (p > 0.05). In the dynamic state, different amounts of TiO2 NP pulses were injected into three pilot-scale BAC filters. The decay of TiO2 NPs in the BAC filters was very slow. Both titanium quantification and scanning electron microscope analysis confirmed the retention of TiO2 NPs in the BAC filters after 134 days of operation. Furthermore, the TiO2 NP pulses considerably reduced the performance of ammonia reduction. This study identified the retention of TiO2 NPs in BAC filters and the negative effect on the ammonia reduction, suggesting a potential threat to DWT by TiO2 NPs.

Evaluation of drinking water treatment combined filter backwash water recycling technology based on comet and micronucleus assay.

PubMed

Chen, Ting; Xu, Yongpeng; Liu, Zhiquan; Zhu, Shijun; Shi, Wenxin; Cui, Fuyi

2016-04-01

Based on the fact that recycling of combined filter backwash water (CFBW) directly to drinking water treatment plants (WTP) is considered to be a feasible method to enhance pollutant removal efficiency, we were motivated to evaluate the genotoxicity of water samples from two pilot-scale drinking water treatment systems, one with recycling of combined backwash water, the other one with a conventional process. An integrated approach of the comet and micronucleus (MN) assays was used with zebrafish (Danio rerio) to investigate the water genotoxicity in this study. The total organic carbon (TOC), dissolved organic carbon (DOC), and trihalomethane formation potential (THMFP), of the recycling process were lower than that of the conventional process. All the results showed that there was no statistically significant difference (P>0.05) between the conventional and recycling processes, and indicated that the genotoxicity of water samples from the recycling process did not accumulate in 15 day continuous recycling trial. It was worth noting that there was correlation between the concentrations of TOC, DOC, UV254, and THMFPs in water and the DNA damage score, with corresponding R(2) values of 0.68, 0.63, 0.28, and 0.64. Nevertheless, both DNA strand breaks and MN frequency of all water samples after disinfection were higher than that of water samples from the two treatment units, which meant that the disinfection by-products (DBPs) formed by disinfection could increase the DNA damage. Both the comet and MN tests suggest that the recycling process did not increase the genotoxicity risk, compared to the traditional process. Copyright © 2015. Published by Elsevier B.V.

Climate and Health Co-Benefits in Low-Income Countries: A Case Study of Carbon Financed Water Filters in Kenya and a Call for Independent Monitoring

PubMed Central

Pickering, Amy J.; Arnold, Benjamin F.; Dentz, Holly N.; Colford, John M.; Null, Clair

2016-01-01

Background: The recent global climate agreement in Paris aims to mitigate greenhouse gas emissions while fostering sustainable development and establishes an international trading mechanism to meet this goal. Currently, carbon offset program implementers are allowed to collect their own monitoring data to determine the number of carbon credits to be awarded. Objectives: We summarize reasons for mandating independent monitoring of greenhouse gas emission reduction projects. In support of our policy recommendations, we describe a case study of a program designed to earn carbon credits by distributing almost one million drinking water filters in rural Kenya to avert the use of fuel for boiling water. We compare results from an assessment conducted by our research team in the program area among households with pregnant women or caregivers in rural villages with low piped water access with the reported program monitoring data and discuss the implications. Discussion: Our assessment in Kenya found lower levels of household water filter usage than the internal program monitoring reported estimates used to determine carbon credits; we found 19% (n = 4,041) of households reported filter usage 2–3 years after filter distribution compared to the program stated usage rate of 81% (n = 14,988) 2.7 years after filter distribution. Although carbon financing could be a financially sustainable approach to scale up water treatment and improve health in low-income settings, these results suggest program effectiveness will remain uncertain in the absence of requiring monitoring data be collected by third-party organizations. Conclusion: Independent monitoring should be a key requirement for carbon credit verification in future international carbon trading mechanisms to ensure programs achieve benefits in line with sustainable development goals. Citation: Pickering AJ, Arnold BF, Dentz HN, Colford JM Jr., Null C. 2017. Climate and health co-benefits in low-income countries: a case

Climate and Health Co-Benefits in Low-Income Countries: A Case Study of Carbon Financed Water Filters in Kenya and a Call for Independent Monitoring.

PubMed

Pickering, Amy J; Arnold, Benjamin F; Dentz, Holly N; Colford, John M; Null, Clair

2017-03-01

The recent global climate agreement in Paris aims to mitigate greenhouse gas emissions while fostering sustainable development and establishes an international trading mechanism to meet this goal. Currently, carbon offset program implementers are allowed to collect their own monitoring data to determine the number of carbon credits to be awarded. We summarize reasons for mandating independent monitoring of greenhouse gas emission reduction projects. In support of our policy recommendations, we describe a case study of a program designed to earn carbon credits by distributing almost one million drinking water filters in rural Kenya to avert the use of fuel for boiling water. We compare results from an assessment conducted by our research team in the program area among households with pregnant women or caregivers in rural villages with low piped water access with the reported program monitoring data and discuss the implications. Our assessment in Kenya found lower levels of household water filter usage than the internal program monitoring reported estimates used to determine carbon credits; we found 19% ( n = 4,041) of households reported filter usage 2-3 years after filter distribution compared to the program stated usage rate of 81% ( n = 14,988) 2.7 years after filter distribution. Although carbon financing could be a financially sustainable approach to scale up water treatment and improve health in low-income settings, these results suggest program effectiveness will remain uncertain in the absence of requiring monitoring data be collected by third-party organizations. Independent monitoring should be a key requirement for carbon credit verification in future international carbon trading mechanisms to ensure programs achieve benefits in line with sustainable development goals. Citation: Pickering AJ, Arnold BF, Dentz HN, Colford JM Jr., Null C. 2017. Climate and health co-benefits in low-income countries: a case study of carbon financed water filters in Kenya and

Water-filtered infrared-A (wIRA) can act as a penetration enhancer for topically applied substances

PubMed Central

Otberg, Nina; Grone, Diego; Meyer, Lars; Schanzer, Sabine; Hoffmann, Gerd; Ackermann, Hanns; Sterry, Wolfram; Lademann, Jürgen

2008-01-01

Background: Water-filtered infrared-A (wIRA) irradiation has been shown to enhance penetration of clinically used topically applied substances in humans through investigation of functional effects of penetrated substances like vasoconstriction by cortisone. Aim of the study: Investigation of the influence of wIRA irradiation on the dermatopharmacokinetics of topically applied substances by use of optical methods, especially to localize penetrating substances, in a prospective randomised controlled study in humans. Methods: The penetration profiles of the hydrophilic dye fluorescein and the lipophilic dye curcumin in separate standard water-in-oil emulsions were determined on the inner forearm of test persons by tape stripping in combination with spectroscopic measurements. Additionally, the penetration was investigated in vivo by laser scanning microscopy. Transepidermal water loss, hydration of the epidermis, and surface temperature were determined. Three different procedures (modes A, B, C) were used in a randomised order on three separate days of investigation in each of 12 test persons. In mode A, the two dyes were applied on different skin areas without water-filtered infrared-A (wIRA) irradiation. In mode B, the skin surface was irradiated with wIRA over 30 min before application of the two dyes (Hydrosun® radiator type 501, 10 mm water cuvette, orange filter OG590, water-filtered spectrum: 590–1400 nm with dominant amount of wIRA). In mode C, the two dyes were applied and immediately afterwards the skin was irradiated with wIRA over 30 min. In all modes, tape stripping started 30 min after application of the formulations. Main variable of interest was the ratio of the amount of the dye in the deeper (second) 10% of the stratum corneum to the amount of the dye in the upper 10% of the stratum corneum. Results: The penetration profiles of the hydrophilic fluorescein showed in case of pretreatment or treatment with wIRA (modes B and C) an increased

Exposure to space radiation of high-performance infrared multilayer filters and materials technology experiment (A0056)

NASA Technical Reports Server (NTRS)

Hawkins, Gary J.; Seeley, John S.; Hunneman, Roger

1992-01-01

Infrared optical multilayer filters and materials were exposed to the space environment of low Earth orbit on LDEF. The effects are summarized of that environment on the physical and optical properties of the filters and materials flown.

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

PubMed

Tatari, K; Smets, B F; Albrechtsen, H-J

2016-09-15

The biokinetic behavior of NH4(+) removal was investigated at different depths of a rapid sand filter treating groundwater for drinking water preparation. Filter materials from the top, middle and bottom layers of a full-scale filter were exposed to various controlled NH4(+) loadings in a continuous-flow lab-scale assay. NH4(+) removal capacity, estimated from short term loading up-shifts, was at least 10 times higher in the top than in the middle and bottom filter layers, consistent with the stratification of Ammonium Oxidizing Bacteria (AOB). AOB density increased consistently with the NH4(+) removal rate, indicating their primarily role in nitrification under the imposed experimental conditions. The maximum AOB cell specific NH4(+) removal rate observed at the bottom was at least 3 times lower compared to the top and middle layers. Additionally, a significant up-shift capacity (4.6 and 3.5 times) was displayed from the top and middle layers, but not from the bottom layer at increased loading conditions. Hence, AOB with different physiological responses were active at the different depths. The biokinetic analysis predicted that despite the low NH4(+) removal capacity at the bottom layer, the entire filter is able to cope with a 4-fold instantaneous loading increase without compromising the effluent NH4(+). Ultimately, this filter up-shift capacity was limited by the density of AOB and their biokinetic behavior, both of which were strongly stratified. Copyright © 2016 Elsevier Ltd. All rights reserved.

Estimation of water level and steam temperature using ensemble Kalman filter square root (EnKF-SR)

NASA Astrophysics Data System (ADS)

Herlambang, T.; Mufarrikoh, Z.; Karya, D. F.; Rahmalia, D.

2018-04-01

The equipment unit which has the most vital role in the steam-powered electric power plant is boiler. Steam drum boiler is a tank functioning to separate fluida into has phase and liquid phase. The existence in boiler system has a vital role. The controlled variables in the steam drum boiler are water level and the steam temperature. If the water level is higher than the determined level, then the gas phase resulted will contain steam endangering the following process and making the resulted steam going to turbine get less, and the by causing damages to pipes in the boiler. On the contrary, if less than the height of determined water level, the resulted height will result in dry steam likely to endanger steam drum. Thus an error was observed between the determined. This paper studied the implementation of the Ensemble Kalman Filter Square Root (EnKF-SR) method in nonlinear model of the steam drum boiler equation. The computation to estimate the height of water level and the temperature of steam was by simulation using Matlab software. Thus an error was observed between the determined water level and the steam temperature, and that of estimated water level and steam temperature. The result of simulation by Ensemble Kalman Filter Square Root (EnKF-SR) on the nonlinear model of steam drum boiler showed that the error was less than 2%. The implementation of EnKF-SR on the steam drum boiler r model comprises of three simulations, each of which generates 200, 300 and 400 ensembles. The best simulation exhibited the error between the real condition and the estimated result, by generating 400 ensemble. The simulation in water level in order of 0.00002145 m, whereas in the steam temperature was some 0.00002121 kelvin.

Reducing and verifying haloacetic acids in treated drinking water using a biological filter system.

PubMed

Lou, Jie C; Chan, Hung Y; Yang, Chih Y; Tseng, Wei B; Han, Jia Y

2014-01-01

This study focused on reducing the haloacetic acid (HAA) concentrations in treated drinking water. HAA has been thought to be one possible nutrient supporting heterotrophic bacteria regrowth in drinking water. In this study, experiments were conducted using a pilot-scale system to evaluate the efficiency of biological filters (BF) for reducing excess HAA concentrations in water. The BF system reduced the total HAA concentration and the concentrations of five HAA species in the water. Dichloroacetic acid (DCAA), monobromoacetic acid (MBAA) and dibromoacetic acid (DBAA) were the three main HAA5 species that were present in the treated drinking water in this investigation. Combined, these three species represent approximately 77% of the HAA5 in the finished water after BF. The verification of the empirical HAA equation for the outlet in the BF system indicated linear relationships with high correlation coefficients. The empirical equation for the HAA5 concentrations in the finished water was established by examining other nutrients (e.g., dissolved organic carbon (DOC), ultraviolet absorbance at 254 nm wavelength (UV254), and ammonia nitrogen) that can reduce pathogenic contamination. These findings may be useful for designing advanced processes for conventional water treatment plants or for managing water treatment and distribution systems for providing high-quality drinking water.

Heat for wounds – water-filtered infrared-A (wIRA) for wound healing – a review

PubMed Central

Hoffmann, Gerd; Hartel, Mark; Mercer, James B.

2016-01-01

Background: Water-filtered infrared-A (wIRA) is a special form of heat radiation with high tissue penetration and a low thermal load to the skin surface. wIRA corresponds to the major part of the sun’s heat radiation, which reaches the surface of the Earth in moderate climatic zones filtered by water and water vapour of the atmosphere. wIRA promotes healing of acute and chronic wounds both by thermal and thermic as well as by non-thermal and non-thermic cellular effects. Methods: This publication includes a literature review with search in PubMed/Medline for “water-filtered infrared-A” and “wound”/”ulcus” or “wassergefiltertes Infrarot A” and “Wunde”/”Ulkus”, respectively (publications in English and German), and additional analysis of study data. Seven prospective clinical studies (of these six randomized controlled trials (RCT), the largest study with n=400 patients) were identified and included. All randomized controlled clinical trials compare a combination of high standard care plus wIRA treatment vs. high standard care alone. The results below marked with “vs.” present these comparisons. Results: wIRA increases tissue temperature (+2.7°C at a tissue depth of 2 cm), tissue oxygen partial pressure (+32% at a tissue depth of 2 cm) and tissue perfusion (effect sizes within the wIRA group). wIRA promotes normal as well as disturbed wound healing by diminishing inflammation and exudation, by promotion of infection defense and regeneration, and by alleviation of pain (with respect to alleviation of pain, without any exception during 230 irradiations, 13.4 vs. 0.0 on a visual analogue scale (VAS 0–100), median difference between groups 13.8, 95% confidence interval (CI) 12.3/16.7, p<0.000001) with a substantially reduced need for analgesics (52–69% less in the three groups with wIRA compared to the three control groups in visceral surgery, p=0.000020 and 0.00037 and 0.0045, respectively; total of 6 vs. 14.5 analgesic tablets on 6

Laser-induced breakdown spectroscopy (LIBS) analysis of calcium ions dissolved in water using filter paper substrates: an ideal internal standard for precision improvement.

PubMed

Choi, Daewoong; Gong, Yongdeuk; Nam, Sang-Ho; Han, Song-Hee; Yoo, Jonghyun; Lee, Yonghoon

2014-01-01

We report an approach for selecting an internal standard to improve the precision of laser-induced breakdown spectroscopy (LIBS) analysis for determining calcium (Ca) concentration in water. The dissolved Ca(2+) ions were pre-concentrated on filter paper by evaporating water. The filter paper was dried and analyzed using LIBS. By adding strontium chloride to sample solutions and using a Sr II line at 407.771 nm for the intensity normalization of Ca II lines at 393.366 or 396.847 nm, the analysis precision could be significantly improved. The Ca II and Sr II line intensities were mapped across the filter paper, and they showed a strong positive shot-to-shot correlation with the same spatial distribution on the filter paper surface. We applied this analysis approach for the measurement of Ca(2+) in tap, bottled, and ground water samples. The Ca(2+) concentrations determined using LIBS are in good agreement with those obtained from flame atomic absorption spectrometry. Finally, we suggest a homologous relation of the strongest emission lines of period 4 and 5 elements in groups IA and IIA based on their similar electronic structures. Our results indicate that the LIBS can be effectively applied for liquid analysis at the sub-parts per million level with high precision using a simple drying of liquid solutions on filter paper and the use of the correct internal standard elements with the similar valence electronic structure with respect to the analytes of interest.

A Search for Water in a Super-Earth Atmosphere: High-resolution Optical Spectroscopy of 55Cancri e

DOE Office of Scientific and Technical Information (OSTI.GOV)

Esteves, Lisa J.; De Mooij, Ernst J. W.; Watson, Chris

We present the analysis of high-resolution optical spectra of four transits of 55Cnc e, a low-density super-Earth that orbits a nearby Sun-like star in under 18 hr. The inferred bulk density of the planet implies a substantial envelope, which, according to mass–radius relationships, could be either a low-mass extended or a high-mass compact atmosphere. Our observations investigate the latter scenario, with water as the dominant species. We take advantage of the Doppler cross-correlation technique, high-spectral resolution, and the large wavelength coverage of our observations to search for the signature of thousands of optical water absorption lines. Using our observations with HDSmore » on the Subaru telescope and ESPaDOnS on the Canada–France–Hawaii Telescope, we are able to place a 3 σ lower limit of 10 g mol{sup −1} on the mean-molecular weight of 55Cnc e’s water-rich (volume mixing ratio >10%), optically thin atmosphere, which corresponds to an atmospheric scale-height of ∼80 km. Our study marks the first high-spectral resolution search for water in a super-Earth atmosphere, and demonstrates that it is possible to recover known water-vapor absorption signals in a nearby super-Earth atmosphere, using high-resolution transit spectroscopy with current ground-based instruments.« less

Water in Earth's mantle: Hydrogen analysis of mantle olivine, pyroxenes and garnet using the SIMS

NASA Technical Reports Server (NTRS)

Kurosawa, Masanori; Yurimoto, Hisayoshi; Sueno, Shigeho

1993-01-01

Hydrogen (or water) in the Earth's interior plays a key role in the evolution and dynamics of the planet. However, the abundance and the existence form of the hydrogen have scarcely been clear in practice. Hydrogen in the mantle was incorporated in the interior during the formation of the Earth. The incorporated hydrogen was hardly possible to concentrate locally inside the Earth considering its high mobility and high reactivity. The hydrogen, preferably, could be distributed homogeneously over the mantle and the core by the subsequent physical and chemical processes. Therefore, hydrogen in the mantle could be present in the form of trace hydrogen in nominally anhydrous mantle minerals. The hydrogen and the other trace elements in mantle olivines, orthopyroxenes, clinopyroxenes, and garnets were determined using secondary ion mass spectrometry (SIMS) for elucidating (1) the exact hydrogen contents, (2) the correlation between the hydrogen and the other trace elements, (3) the dependence of the hydrogen contents on the depth, and (4) the dependence of the whole rock water contents on the depth.

Removal of trace organic micropollutants by drinking water biological filters.

PubMed

Zearley, Thomas L; Summers, R Scott

2012-09-04