Precipitation-adsorption process for the decontamination of nuclear waste supernates

DOEpatents

Lee, Lien-Mow; Kilpatrick, Lester L.

1984-01-01

High-level nuclear waste supernate is decontaminated of cesium by precipitation of the cesium and potassium with sodium tetraphenyl boron. Simultaneously, strontium-90 is removed from the waste supernate sorption of insoluble sodium titanate. The waste solution is then filtered to separate the solution decontaminated of cesium and strontium.

Precipitation-adsorption process for the decontamination of nuclear waste supernates

DOEpatents

Lee, L.M.; Kilpatrick, L.L.

1982-05-19

High-level nuclear waste supernate is decontaminated of cesium by precipitation of the cesium and potassium with sodium tetraphenyl boron. Simultaneously, strontium-90 is removed from the waste supernate sorption of insoluble sodium titanate. The waste solution is then filtered to separate the solution decontaminated of cesium and strontium.

INTERIOR OF SHT (ROTARY DRYER FOR SODA) BUILDING OR DRYSIDE ...

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

INTERIOR OF SHT (ROTARY DRYER FOR SODA) BUILDING OR DRYSIDE DRYERS WHICH REMOVED TRACES OF LIQUID FROM STD FILTRATE. HEAT CONVERTED SODIUM BICARBONATE TO SODIUM CARBONATE OR SODA ASH, THE PRINCIPAL PRODUCT OF THE WORKS. - Solvay Process Company, SHT Building, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

Study on treatment technology of wastewater from hydrolysis of acid oil

NASA Astrophysics Data System (ADS)

Li, Yuejin; Lin, Zhiyong; Han, Yali

2017-06-01

In this paper, the degumming of ferric chloride, calcium hydroxide after the removal of acid acidification hydrolysis of waste oil as raw material, through the treatment process to purify the wastewater. Choose different chemical additives, investigation of different temperature, pH value and other factors, find the best extraction condition. Through the orthogonal test of sodium carbonate, sodium oxalate, barium carbonate, compared with three kinds of chemical additives. The best chemical assistant is sodium carbonate, the best treatment temperature is 80 degrees Celsius, pH value is 8.0. After the reaction, the content of calcium and iron ions were determined by suitable methods. The removal rate of calcium ion is 98%, the removal rate of iron ion is 99%, and the effect of calcium and iron ion precipitation on the subsequent evaporation operation is reduced. Finally, the comparison is made to clarify the Dilute Glycerol water solution.

Factors affecting sodium hypochlorite extraction of CCA from treated wood.

PubMed

Gezer, E D; Cooper, P A

2009-12-01

Significant amounts of chromated copper arsenate (CCA) treated wood products, such as utility poles and residential construction wood, remain in service. There is increasing public concern about environmental contamination from CCA-treated wood when it is removed from service for reuse or recycling, placed in landfills or burned in commercial incinerators. In this paper, we investigated the effects of time, temperature and sodium hypochlorite concentration on chromium oxidation and extraction of chromated copper arsenate from CCA-treated wood (Type C) removed from service. Of the conditions evaluated, reaction of milled wood with sodium hypochlorite for one hour at room temperature followed by heating at 75 degrees C for two hours gave the highest extraction efficiency. An average of 95% Cr, 99% Cu and 96% As could be removed from CCA-treated, milled wood by this process. Most of the extracted chromium was oxidized to the hexavalent state and could therefore be recycled in a CCA treating solution. Sodium hypochlorite extracting solutions could be reused several times to extract CCA components from additional treated wood samples.

Removal of brownish-black tarnish on silver-copper alloy objects with sodium glycinate

NASA Astrophysics Data System (ADS)

de Figueiredo, João Cura D.'Ars; Asevedo, Samara Santos; Barbosa, João Henrique Ribeiro

2014-10-01

This article has the principal aim of presenting a new method of chemical cleaning of tarnished silver-copper alloy objects. The chemical cleaning must be harmless to the health, selective to tarnish removal, and easy to use. Sodium glycinate was selected for the study. The reactions of sodium glycinate with tarnish and the silver-copper alloy were evaluated. Products of the reaction, the lixiviated material, and the esthetics of silver-copper alloy coins (used as prototypes) were studied to evaluate if the proposed method can be applied to the cleaning of silver objects. Silver-copper alloys can be deteriorated through a uniform and superficial corrosion process that produces brownish-black tarnish. This tarnish alters the esthetic of the object. The cleaning of artistic and archeological objects requires more caution than regular cleaning, and it must take into account the procedures for the conservation and restoration of cultural heritage. There are different methods for cleaning silver-copper alloy objects, chemical cleaning is one of them. We studied two chemical cleaning methods that use sodium glycinate and sodium acetylglycinate solutions. Silver-copper alloy coins were artificially corroded in a basic thiourea solution and immersed in solutions of sodium glycinate and sodium acetylglycinate. After immersion, optical microscopy and scanning electron microscopy of the surfaces were studied. The sodium glycinate solution was shown to be very efficient in removing the brownish-black tarnish. Absorption spectroscopy measured the percentage of silver and copper lixiviated in immersion baths, and very small quantities of these metals were detected. Infrared absorption spectroscopy and X-ray fluorescence characterized the obtained products. The greater efficiency of the sodium glycinate solution compared to the sodium acetylglycinate solution was explained by chelation and Hard-Soft Acid-Base Theory with the aid of quantum chemical calculations.

Electrolytic decontamination of conductive materials for hazardous waste management

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

Wedman, D.E.; Martinez, H.E.; Nelson, T.O.

1996-12-31

Electrolytic removal of plutonium and americium from stainless steel and uranium surfaces has been demonstrated. Preliminary experiments were performed on the electrochemically based decontamination of type 304L stainless steel in sodium nitrate solutions to better understand the metal removal effects of varying cur-rent density, pH, and nitrate concentration parameters. Material removal rates and changes in surface morphology under these varying conditions are reported. Experimental results indicate that an electropolishing step before contamination removes surface roughness, thereby simplifying later electrolytic decontamination. Sodium nitrate based electrolytic decontamination produced the most uniform stripping of material at low to intermediate pH and at sodiummore » nitrate concentrations of 200 g L{sup -1} and higher. Stirring was also observed to increase the uniformity of the stripping process.« less

The role of sodium pump in the inhibition of smooth muscle responsiveness to agonists during potassium restoration

PubMed Central

Bose, D.; Innes, I. R.

1973-01-01

1. Isometric contractions of cat splenic capsular smooth muscle in response to noradrenaline and histamine were recorded. 2. Removal of potassium from the bathing medium did not change the resting tension or the responsiveness to noradrenaline. Restoration of potassium inhibited responses to noradrenaline or histamine only if the muscles were stimulated with an agonist while in the K-free medium. 3. This inhibition of responses to the agonists due to potassium was reversed rapidly by removing the ion or reversed slowly by prolonged exposure to the ion. The inhibition was also blocked by procedures or agents which block the sodium pump (ouabain, substitution of NaCl by LiCl), inhibit active processes (low ambient temperature) or prevent intracellular accumulation of sodium (substitution of choline for sodium). 4. It is proposed that under special circumstances such as when there is an increase in internal sodium concentration, the sodium pump is probably electrogenic and causes relaxation when activated by external potassium. In the normal muscle the pump is probably electrically neutral. PMID:4777707

Sodium balance in hemodialysis therapy.

PubMed

Kooman, Jeroen P; van der Sande, Frank; Leunissen, Karel; Locatelli, Francesco

2003-01-01

Water and sodium overload is the predominant factor in the pathogenesis of hypertension in dialysis patients. In many dialysis patients, dry weight is not reached because of an imbalance between the interdialytic accumulation of water and sodium and the brief and discontinuous nature of routine dialysis therapy. During dialysis, sodium is removed by convection and to a lesser degree by diffusion. However, with supraphysiologic dialysate sodium concentrations, diffusive influx from dialysate may occur, especially in patients with low predialytic plasma sodium concentrations. Measuring sodium removal during dialysis is difficult and hampered by the variability in conventional sodium measurements. Ionic mass removal by continuous measurement of conductivity in the dialysate ports appears to be a promising tool for the approximation of sodium removal during dialysis. While the beneficial effects of concomitant water and sodium removal on blood pressure control in dialysis patients are undisputed, it is less well known whether a change in hydrosodium balance solely by reducing dialysate sodium is beneficial. Considering the inherent dangers of such an approach (intradialytic hemodynamic instability), the beneficial effects of strict dietary sodium restriction appear to be of much larger clinical benefit. It has become possible to individualize dialysate sodium concentration by means of online measurements of plasma conductivity and adjustment of dialysate conductivity by feedback technologies. The clinical benefits of this approach deserve further study. Still, reducing dietary sodium intake remains the most important tool in improving blood control in dialysis patients.

Vanadium Recovery from Oil Fly Ash by Carbon Removal and Roast-Leach Process

NASA Astrophysics Data System (ADS)

Jung, Myungwon; Mishra, Brajendra

2018-02-01

This research mainly focuses on the recovery of vanadium from oil fly ash by carbon removal and the roast-leach process. The oil fly ash contained about 85% unburned carbon and 2.2% vanadium by weight. A vanadium-enriched product was obtained after carbon removal, and the vanadium content of this product was 19% by weight. Next, the vanadium-enriched product was roasted with sodium carbonate to convert vanadium oxides to water-soluble sodium metavanadate. The roasted sample was leached with water at 60°C, and the extraction percentage of vanadium was about 92% by weight. Several analytical techniques, such as inductively coupled plasma atomic emission spectroscopy (ICP-AES), x-ray fluorescence (XRF), and thermogravimetric and differential thermal analysis (TG-DTA), were utilized for sample analyses. Thermodynamic modeling was also conducted with HSC chemistry software to explain the experimental results.

PROCESS OF DECONTAMINATING MATERIAL CONTAMINATED WITH RADIOACTIVITY

DOEpatents

Overholt, D.C.; Peterson, M.D.; Acken, M.F.

1958-09-16

A process is described for decontaminating metallic objects, such as stainless steel equipment, which consists in contacting such objects with nltric acid in a concentration of 35 to 60% to remove the major portion of the contamination; and thereafter contacting the partially decontaminated object with a second solution containing up to 20% of alkali metal hydroxide and up to 20% sodium tartrate to remove the remaining radioactive contaminats.

METHOD FOR REMOVING SODIUM OXIDE FROM LIQUID SODIUM

DOEpatents

Bruggeman, W.H.; Voorhees, B.G.

1957-12-01

A method is described for removing sodium oxide from a fluent stream of liquid sodium by coldtrapping the sodium oxide. Apparatus utilizing this method is disclosed in United States Patent No. 2,745,552. Sodium will remain in a molten state at temperatures below that at which sodium oxide will crystallize out and form solid deposits, therefore, the contaminated stream of sodium is cooled to a temperature at which the solubility of sodium oxide in sodium is substantially decreased. Thereafter the stream of sodium is passed through a bed of stainless steel wool maintained at a temperature below that of the stream. The stream is kept in contact with the wool until the sodium oxide is removed by crystal growth on the wool, then the stream is reheated and returned to the system. This method is useful in purifying reactor coolants where the sodium oxide would otherwise deposit out on the walls and eventually plug the coolant tubes.

Selecting an appropriate method to remove cyanide from the wastewater of Moteh gold mine using a mathematical approach.

PubMed

Seyyed Alizadeh Ganji, Seyyed Mohammad; Hayati, Mohammad

2018-06-05

The presence of cyanide ions in wastewater is dangerous to the health and life of living creatures, especially humans. Cyanide concentration should not exceed the acceptable limit in wastewaters to avoid their adverse effects to the environment. In this paper, in order to select the most appropriate method to remove cyanide from the wastewater of the Moteh gold mine, based on the experts' opinions, the use of calcium hypochlorite, sodium hypochlorite, and hydrogen peroxide was chosen as forerunning alternative in the form of a multi-stage model. Then, seven criteria including the amount of material consumed, ease of implementation, safety, ability to remove cyanide, pH, time, and cost of the process to assess the considered methods were determined. Afterwards, seven experts conducted numerous experiments to examine the conditions of each of these criteria. Then, by employing a mathematical method called "numerical taxonomy," the use of sodium hypochlorite was suggested as the best method to remove cyanide from the wastewater of the Moteh gold mine. Finally, the TOPSIS model was used to validate the proposed model, which led to the same results of the suggested method. Also, the results of employing taxonomic analysis and TOPSIS method suggested the use of sodium hypochlorite as the best method for cyanide removal from wastewater. In addition, according to the analysis of various experiments, conditions for complete removal of cyanide using sodium hypochlorite included concentration (8.64 g/L), pH (12.3), and temperature (12 °C).

Develop Recovery Systems for Separations of Salts from Process Streams for use in Advanced Life Support System

NASA Technical Reports Server (NTRS)

Colon, Guillermo

1998-01-01

The main objectives of this project were the development of a four-compartment electrolytic cell using high selective membranes to remove nitrate from crop residue leachate and convert it to nitric acid, and the development of an six compartment electrodialysis cell to remove selectively sodium from urine wastes. The recovery of both plant inedible biomass and human wastes nutrients to sustain a biomass production system are important aspects in the development of a controlled ecological life support system (CELSS) to provide the basic human needs required for life support during long term space missions. A four-compartment electrolytic cell has been proposed to remove selectively nitrate from crop residue and to convert it to nitric acid, which is actually used in the NASA-KSC Controlled Ecological Life Support System to control the pH of the aerobic bioreactors and biomass production chamber. Human activities in a closed system require large amount of air, water and minerals to sustain life and also generate wastes. Before using human wastes as nutrients, these must be treated to reduce organic content and to remove some minerals which have adverse effects on plant growth. Of all the minerals present in human urine, sodium chloride (NACl) is the only one that can not be used as nutrient for most plants. Human activities also requires sodium chloride as part of the diet. Therefore, technology to remove and recover sodium chloride from wastes is highly desirable. A six-compartment electrodialysis cell using high selective membranes has been proposed to remove and recover NaCl from human urine.

Effects of Whole-Body VX Vapor Exposure on Lethality in Rats

DTIC Science & Technology

2007-01-01

J. "New Method for Hemoglobin Determination by Using Sodium Lauryl Sulfate (SLS)." Clin. Biochem. 15(1) 83-88 (1982). Prins, J, "Product and Process...regenerated VX-G and deuterated internal standard VX-G were eluted with I mL ethyl acetate that was collected and dried over anhydrous sodium sulfate ...anhydrous sodium sulfate . The ethyl acetate was removed from the collection tube and filtered through a 0.2 lim nylon Acrodisc syringe filter (Pall Gelman

Method for aqueous radioactive waste treatment

DOEpatents

Bray, L.A.; Burger, L.L.

1994-03-29

Plutonium, strontium, and cesium found in aqueous waste solutions resulting from nuclear fuel processing are removed by contacting the waste solutions with synthetic zeolite incorporating up to about 5 wt % titanium as sodium titanate in an ion exchange system. More than 99.9% of the plutonium, strontium, and cesium are removed from the waste solutions. 3 figures.

Method for aqueous radioactive waste treatment

DOEpatents

Bray, Lane A.; Burger, Leland L.

1994-01-01

Plutonium, strontium, and cesium found in aqueous waste solutions resulting from nuclear fuel processing are removed by contacting the waste solutions with synthetic zeolite incorporating up to about 5 wt % titanium as sodium titanate in an ion exchange system. More than 99.9% of the plutonium, strontium, and cesium are removed from the waste solutions.

More Efficient Sodium Removal by Ultrafiltration Compared to Diuretics in Acute Heart Failure; Underexplored and Overstated.

PubMed

Kazory, Amir

2016-01-01

Enhanced removal of sodium has often been cited as an advantage of ultrafiltration (UF) therapy over diuretic-based medical treatment in the management of acute decompensated heart failure. However, so far clinical studies have rarely evaluated the precise magnitude of sodium removal, and this assumption is largely based on the physiologic mechanisms and anecdotal observations that predate the contemporary management of heart failure. Recent data suggest that patients treated with UF experience substantial reduction in urinary sodium excretion possibly due to prolonged intravascular volume contraction. Consequently, the efficient sodium extraction through production of isotonic ultrafiltrate can be offset by urine hypotonicity. Based on the limited currently available data, it seems unlikely that the persistent benefits of UF could be solely explained by its greater efficiency in sodium removal. The design of the future studies should include frequent measurements of urine sodium to precisely compare the impact of UF and diuretics on sodium balance. © 2016 S. Karger AG, Basel.

CALANDRIA TYPE SODIUM GRAPHITE REACTOR

DOEpatents

Peterson, R.M.; Mahlmeister, J.E.; Vaughn, N.E.; Sanders, W.J.; Williams, A.C.

1964-02-11

A sodium graphite power reactor in which the unclad graphite moderator and fuel elements are contained within a core tank is described. The core tank is submersed in sodium within the reactor vessel. Extending longitudinally through the core thnk are process tubes with fuel elements positioned therein. A bellows sealing means allows axial expansion and construction of the tubes. Within the core tank, a leakage plenum is located below the graphite, and above the graphite is a gas space. A vent line regulates the gas pressure in the space, and another line removes sodium from the plenum. The sodium coolant flows from the lower reactor vessel through the annular space between the fuel elements and process tubes and out into the reactor vessel space above the core tank. From there, the heated coolant is drawn off through an outlet line and sent to the heat exchange. (AEC)

Irreversible modification of sodium channel inactivation in toad myelinated nerve fibres by the oxidant chloramine-T.

PubMed Central

Wang, G K

1984-01-01

The effects of externally applied chloramine-T on the excitability of single toad myelinated nerve fibres were studied. Chloramine-T is a mild oxidant which reacts specifically with the cysteine and methionine residues of proteins. Chloramine-T prolongs the action potential of a single myelinated fibre by more than 1000-fold. This effect is concentration- and time-dependent; higher concentrations and longer incubation times increase prolongation. Under voltage-clamp conditions, sodium channel inactivation is markedly inhibited by chloramine-T while sodium channel activation remains normal. Prolonged depolarization of the membrane leads to a maintained sodium current. The maintained sodium currents show activation kinetics, dependence on membrane potential, and reversal potentials which are similar to those of normal, inactivating sodium currents in untreated fibres. Both the maintained and the peak sodium currents are equally inhibited by tetrodotoxin. After partial removal of sodium inactivation by brief exposures to chloramine-T, the voltage dependence of the steady-state sodium current inactivation (h infinity) is shifted in the depolarized direction by about 20 mV, even after correction for the non-inactivating component contributed by the maintained current. The phenomena described here imply that cysteine or methionine residues are critical for the sodium channel inactivation processes. The two different modifications of inactivation, its removal shown by the maintained current, and the shift in the voltage-dependence of the remaining inactivatable channels, reveal that at least two separate residues are modified by chloramine-T. PMID:6321714

Removal of sodium lauryl sulphate by coagulation/flocculation with Moringa oleifera seed extract.

PubMed

Beltrán-Heredia, J; Sánchez-Martín, J

2009-05-30

Among other natural flocculant/coagulant agents, Moringa oleifera seed extract ability to remove an anionic surfactant has been evaluated and it has been found to be very interesting. Sodium lauryl sulphate was removed from aqueous solutions up to 80% through coagulation/flocculation process. pH and temperature were found to be not very important factors in removal efficiency. Freundlich (F), Frumkin-Fowler-Guggenheim (FFG) and Gu-Zhu (GZ) models were used to adjust experimental data in a solid-liquid adsorption hypothesis. Last one resulted to be the most accurate one. Several data fit parameters were determined, as Freundlich order, which was found to be 1.66, Flory-Huggins interaction parameter from FFG model, which was found to be 4.87; and limiting Moringa surfactant adsorption capacity from GZ model, which was found to be 2.13 x 10(-3)mol/g.

Characterization and evaluation of amorphous carbon thin film (ACTF) for sodium ion adsorption

NASA Astrophysics Data System (ADS)

Fathy, Mahmoud; Mousa, Mahmoud Ahmed; Moghny, Th. Abdel; Awadallah, Ahmed E.

2017-12-01

The removal of sodium ions from aqueous solutions by adsorption onto amorphous carbon thin film (ACTF) has been studied in batch mode. In this work, the ACTF as new adsorbent was synthesized based on rice straw, then its structure and properties were taken into consideration to study its ability to adsorb sodium ions from synthetic water. The influence of pH, contact time, and temperature of the ion adsorption on ACTF was also studied using batch tests. We found that the contact time of sodium adsorption and its isothermal adsorption studied were described by pseudo-second-order kinetic model and Langmuir isotherm, respectively. Our results indicated that the adsorption of sodium ions on ACTF become be stronger and depends on pH, furthermore, the maximum adsorption capacities of sodium on ACTF recorded 107, 120 and 135 mg g-1 at 35, 45, and 65 °C. The thermodynamic parameters explain that the adsorption of sodium ions on ACTF is a spontaneous process and endothermic reaction. According to adsorption studies, we found that the ACTF can be used effectively for ion chromatography or desalinate sodium ion using ion exchange process in the hybrid desalination process with insignificant loss of adsorption capacity. However, the ACTF has better properties than any other carbon materials obtained from an agricultural byproduct.

Kinetic and thermodynamic studies on the adsorption of anionic surfactant on quaternary ammonium cationic cellulose.

PubMed

Zhang, Yuanzhang; Shi, Wenjian; Zhou, Hualan; Fu, Xing; Chen, Xuan

2010-06-01

Removal of anionic surfactants from aqueous solutions by adsorption onto quaternary ammonium cationic cellulose (QACC) was investigated. The effects of solution acidity, initial concentration, adsorption time, and temperature on the adsorption of sodium dodecyl-benzene sulfonate (SDBS), sodium lauryl sulfate (SLS), and sodium dodecyl sulfonate (SDS) were studied. The kinetic experimental data fit well with the pseudo-second-order model; the rate constant of the adsorption increased with temperature. The values of apparent activation energy for the adsorption were calculated as ranging from 10.2 to 17.4 kJ/ mol. The adsorption isotherm can be described by the Langmuir isotherm. The values of thermodynamic parameters (deltaH0, deltaS0, and deltaG0) for the adsorption indicated that this process was spontaneous and endothermic. At 318 K, the saturated adsorption capacities of QACC for SDBS, SLS, and SDS were 1.75, 1.53, and 1.39 mmol/g, respectively. The adsorption process was mainly chemisorption and partially physisorption. The results show that QACC is effective for the removal of anionic surfactants.

PRECIPITATION OF ZIRCONIUM AND FLUORIDE IONS FROM SOLUTIONS

DOEpatents

Newby, B.J.

1963-06-11

A process is given for removing zirconium and fluorine ions from aqueous solutions also containing uranium(VI). The precipitation is carried out with sodium formate, and the uranium remains in solution. (AEC)

Water-dissolvable sodium sulfate nanowires as a versatile template for the fabrication of polyelectrolyte- and metal-based nanotubes.

PubMed

Pu, Ying-Chih; Hwu, Jih Ru; Su, Wu-Chou; Shieh, Dar-Bin; Tzeng, Yonhua; Yeh, Chen-Sheng

2006-09-06

This study presents the synthesis of water-dissolvable sodium sulfate nanowires, where Na(2)SO(4) nanowires were produced by an easy reflux process in an organic solvent, N,N-dimethylformamide (DMF) and formed from the coexistence of AgNO(3), SnCl(2), dodecylsodium sulfate (SDS), and cetyltrimethylammonium bromide (CTAB). Na(2)SO(4) nanowires were derived from SDS, and the morphology control of the Na(2)SO(4) nanowires was established by the cooperative effects of Sn and NO(3)(-), while CTAB served as the template and led to homogeneous nanowires with a smooth surface. Since the as-synthesized sodium sulfate nanowires are readily dissolved in water, these nanowires can be treated as soft templates for the fabrication of nanotubes by removing the Na(2)SO(4) core. This process is therefore significantly better than other reported methodologies to remove the templates under harsh condition. We have demonstrated the preparation of biocompatible polyelectrolyte (PE) nanotubes using a layer-by-layer (LbL) method on the Na(2)SO(4) nanowires and the formation of Au nanotubes by the self-assembly of Au nanoparticles. In both nanotube synthesis processes, PEI (polyethylenimine), PAA (poly(acrylic acid)), and Au nanoparticles served as the building blocks on the Na(2)SO(4) templates, which were then rinsed with water to remove the core templates. This unique water-dissolvable template is anticipated to bring about versatile and flexible downstream applications.

Efficient Pb(II) removal using sodium alginate-carboxymethyl cellulose gel beads: Preparation, characterization, and adsorption mechanism.

PubMed

Ren, Huixue; Gao, Zhimin; Wu, Daoji; Jiang, Jiahui; Sun, Youmin; Luo, Congwei

2016-02-10

Alginate-carboxymethyl cellulose (CMC) gel beads were prepared in this study using sodium alginate (SA) and sodium CMC through blending and cross-linking. The specific surface area and aperture of the prepared SA-CMC gel beads were tested. The SA-CMC structure was characterized and analyzed via infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Static adsorption experiment demonstrated that Pb(II) adsorption of SA-CMC exceeded 99% under the optimized conditions. In addition, experiments conducted under the same experimental conditions showed that the lead ion removal efficiency of SA-CMC was significantly higher than that of conventional adsorbents. The Pb(II) adsorption process of SA-CMC followed the Langmuir adsorption isotherm, and the dynamic adsorption model could be described through a pseudo-second-order rate equation. Pb(II) removal mechanisms of SA-CMC, including physical, chemical, and electrostatic adsorptions, were discussed based on microstructure analysis and adsorption kinetics. Chemical adsorption was the main adsorption method among these mechanisms. Copyright © 2015 Elsevier Ltd. All rights reserved.

Method of and apparatus for removing silicon from a high temperature sodium coolant

DOEpatents

Yunker, W.H.; Christiansen, D.W.

1983-11-25

This patent discloses a method of and system for removing silicon from a high temperature liquid sodium coolant system for a nuclear reactor. The sodium is cooled to a temperature below the silicon saturation temperature and retained at such reduced temperature while inducing high turbulence into the sodium flow for promoting precipitation of silicon compounds and ultimate separation of silicon compound particles from the liquid sodium.

Method of and apparatus for removing silicon from a high temperature sodium coolant

DOEpatents

Yunker, Wayne H.; Christiansen, David W.

1987-05-05

A method of and system for removing silicon from a high temperature liquid sodium coolant system for a nuclear reactor. The sodium is cooled to a temperature below the silicon saturation temperature and retained at such reduced temperature while inducing high turbulence into the sodium flow for promoting precipitation of silicon compounds and ultimate separation of silicon compound particles from the liquid sodium.

Method of and apparatus for removing silicon from a high temperature sodium coolant

DOEpatents

Yunker, Wayne H.; Christiansen, David W.

1987-01-01

A method of and system for removing silicon from a high temperature liquid sodium coolant system for a nuclear reactor. The sodium is cooled to a temperature below the silicon saturation temperature and retained at such reduced temperature while inducing high turbulence into the sodium flow for promoting precipitation of silicon compounds and ultimate separation of silicon compound particles from the liquid sodium.

Pilot scale-SO{sub 2} control by dry sodium bicarbonate injection and an electrostatic precipitator

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

Pliat, M.J.; Wilder, J.M.

2007-10-15

A 500 actual cubic feet gas per minute (acfm) pilot-scale SO{sub 2} control study was undertaken to investigate flue gas desulfurization (FGD) by dry sodium sorbents in 400{sup o}F (204.5{sup o}C) flue gases emitted from a coal fired boiler with flue gas concentrations between 350 and 2500 ppm SO{sub 2}. Powdered sodium alkaline reagents were injected into the hot flue gas downstream of the air preheater and the spent reagents were collected using an electrostatic precipitator. Three different sorbents were used: processed sodium bicarbonate of two particle sizes; solution mined sodium bicarbonate, and processed sodium sesquicarbonate. SO{sub 2} concentrations weremore » measured upstream of the reagent injection, 25-ft (7.62 m) downstream of the injection point, and downstream of the electrostatic precipitator. SO{sub 2} collection efficiencies ranged from 40 to 80% using sodium bicarbonate stoichiometric ratios from 0.5 to 3.0. Much of the in-duct SO{sub 2} removal occurred during the first second of reagent reaction time, indicating that the sulfur dioxide-sodium reaction rates may be faster than have been measured for fixed bed measurements reported in the literature.« less

Removal of metals from aqueous solution and sea water by functionalized graphite nanoplatelets based electrodes.

PubMed

Mishra, Ashish Kumar; Ramaprabhu, S

2011-01-15

In the present wok, we have demonstrated the simultaneous removal of sodium and arsenic (pentavalent and trivalent) from aqueous solution using functionalized graphite nanoplatelets (f-GNP) based electrodes. In addition, these electrodes based water filter was used for multiple metals removal from sea water. Graphite nanoplatelets (GNP) were prepared by acid intercalation and thermal exfoliation. Functionalization of GNP was done by further acid treatment. Material was characterized by different characterization techniques. Performance of supercapacitor based water filter was analyzed for the removal of high concentration of arsenic (trivalent and pentavalent) and sodium as well as for desalination of sea water, using cyclic voltametry (CV) and inductive coupled plasma-optical emission spectroscopy (ICP-OES) techniques. Adsorption isotherms and kinetic characteristics were studied for the simultaneous removal of sodium and arsenic (both trivalent and pentavalent). Maximum adsorption capacities of 27, 29 and 32 mg/g for arsenate, arsenite and sodium were achieved in addition to good removal efficiency for sodium, magnesium, calcium and potassium from sea water. Copyright © 2010 Elsevier B.V. All rights reserved.

7 CFR 301.87-10 - Treatments.

Code of Federal Regulations, 2010 CFR

2010-01-01

... germinated may be damaged by this procedure. (b) True seed (fuzz): Immerse in 0.525 percent sodium... dry heat at 70 °C (158 °F) for 2 hours. (d) Sugarcane harvesting and processing equipment: Remove all...

METHOD OF PROCESSING MONAZITE SAND

DOEpatents

Calkins, G.D.

1957-10-29

A method is given for the pretreatment of monazite sand with sodium hydroxide. When momazite sand is reacted with sodium hydroxide, the thorium, uranium, and rare earths are converted to water-insoluble hydrous oxides; but in the case of uranium, the precipitate compound may at least partly consist of a slightly soluble uranate. According to the patent, monazite sand is treated with an excess of aqueous sodium hydroxide solution, and the insoluble compounds of thorium, uranium, and the rare earths are separated from the aqueous solution. This solution is then concentrated causing sodium phosphate to crystallize out. The crystals are removed from the remaining solution, and the solution is recycled for reaction with a mew supply of momazite sand.

Iron and boron removal from sodium silicate using complexation methods

NASA Astrophysics Data System (ADS)

Wahyuningsih, S.; Suharty, N. S.; Pramono, E.; Ramelan, A. H.; Sasongko, B.; Dewi, A. O. T.; Hidayat, R.; Sulistyono, E.; Handayani, M.; Firdiyono, F.

2018-05-01

Silica purification of other materials is needed to improve the purity of silica that suitable for solar cells requirement. The silica is obtained from roasting of sand minerals in sodium silicate form. Iron (Fe) and boron (B) are an impurity that must be separated to obtain high pure silica. Separation of Fe and B used complexation methods. Chitosan-EDTA is used to remove Fe component and curcumin is used to remove B component. The elemental analysis with Atomic Absorption Spectrophotometer (AAS) showed the amount of Fe in sodium silicate decreased after binding to Chitosan EDTA. The contact duration between sodium silicate and chitosan-EDTA at baseline did not affect the results. Then the removal of B from sodium silicate using curcumin was done under basic conditions. B-Curcumin complexes were known from the wavelength number shifts of O-H, C-O, and C = O vibrational in the IR spectrum. The results showed that the optimum concentration of curcumin for removal B was 2 × 10-7 M.

Drowning-out crystallisation of sodium sulphate using aqueous two-phase systems.

PubMed

Taboada, M E; Graber, T A; Asenjo, J A; Andrews, B A

2000-06-23

A novel method to obtain crystals of pure, anhydrous salt, using aqueous two-phase systems was studied. A concentrated salt solution is mixed with polyethylene glycol (PEG), upon which three phases are formed: salt crystals, a PEG-rich liquid and a salt-rich liquid. After removal of the solid salt, a two-phase system is obtained. Both liquid phases are recycled, allowing the design of a continuous process, which could be exploited industrially. The phase diagram of the system water-Na2SO4-PEG 3350 at 28 degrees C was used. Several process alternatives are proposed and their economic potential is discussed. The process steps needed to produce sodium sulphate crystals include mixing, crystallisation, settling and, optionally, evaporation of water. The yield of sodium sulphate increases dramatically if an evaporation step is used.

Low-Level Effects of VX Vapor Exposure on Pupil Size and Cholinesterase Levels in Rats

DTIC Science & Technology

2005-03-01

Longwood, FL) along with 25 tL of 2.08 mM sodium lauryl sulfate in a pH 7.2 phosphate buffer (30 mM). The plate was read at 536 nm and 37°C using a...Hemoglobin Determination by Using Sodium Lauryl Sulfate (SLS). Clin. Biochem. 15(1) 83-88 (1982). Prins, J., "Product and Process Comparison," Chapter 7...standard VX-G were eluted with I mL ethyl acetate that was collected and dried over anhydrous sodium sulfate . The ethyl acetate was removed from the

Polyhydroxyalkanoate recovery and effect of in situ extracellular polymeric substances removal from aerobic granules.

PubMed

Gobi, K; Vadivelu, V M

2015-01-01

Polyhydroxyalkanoate (PHA) recovery from aerobic granules was investigated using four cell digestion agents, namely, sodium hypochlorite, sodium hydroxide, acetone and sodium chloride. Simultaneously, the removal of extracellular polymeric substances (EPS) and its effect on PHA yield were investigated. The highest PHA recovery yield was obtained using sodium hypochlorite, accounting for 89% cell dry weight (CDW). The highest PHA was recovered after the sodium hypochlorite completely removed the EPS from the aerobic granules. The average molecular weight (Mw) of the PHA recovered using sodium hypochlorite was 5.31 × 10(5)g/mol with only 1.8% molecular weight degradation. The energy and duration analysis for PHA recovery revealed that the sodium hypochlorite method required the least amount of energy and time at 0.0561 MJ/g PHA and 26 h, respectively. The PHA that was recovered was a P3(HB-co-HV) co-polymer. Copyright © 2015 Elsevier Ltd. All rights reserved.

Carbon protrusions on PTFE surface prepared by ion irradiation and chemical defluorination

NASA Astrophysics Data System (ADS)

Kobayashi, T.; Iwaki, M.

2006-01-01

A surface of PTFE was covered with small protrusions by ion-beam irradiation. In this study, we converted PTFE protrusions into carbon protrusions by a defluorination (carbonization) process using sodium vapor. The morphology, composition and structure were analyzed by SEM-EDX, Raman spectroscopy and TEM. The irradiated PTFE sheets were packed in evacuated glass tubes with a sodium block and kept at 473 K for 2-48 h. The samples were then rinsed in HCl and distilled water to remove NaF precipitates. The EDX measurement showed that the NaF precipitates were completely removed by washing, and the percentage of carbon atoms was controlled from 60% to 99% by the treatment. Raman spectra showed that graphite structures grow during the defluorination process. TEM micrographs showed that the protrusions have a bubble structure and are covered with a thin wall. The carbonized protrusions were conductive and grew perpendicular to the substrate.

Dietary sodium reduction in New Zealand: influence of the Tick label.

PubMed

Ning, Sherry X; Mainvil, Louise A; Thomson, Rachel K; McLean, Rachel M

2017-01-01

The Tick programme of the National Heart Foundation (NHF) is the longest standing voluntary front of pack signpost nutrition logo in New Zealand. It provides a platform for collaboration with the food industry to encourage development of healthier products. This study evaluated the impact of the Tick programme on sodium in processed food. Fifty-two Tick programme products from food categories known to contribute substantially to sodium intake were identified. Sales volumes (kg) from January 2011 to December 2013 were multiplied by changes in sodium content over that time, producing an estimate of programme impact. Five semi-structured interviews with industry representatives were conducted, to look at other influences for sodium reduction, and themes identified through methods of thematic analysis. Over the period, the Tick programme influenced food companies to remove approximately 16 tonnes of salt through the reformulation and formulation of 52 Tick-approved breakfast cereals, edible oil spreads, cooking sauces and processed poultry products. Other factors influencing sodium reduction reported by company representatives included increased consumer and industry interest in healthier product nutrition profiles and other sodium reduction programmes targeting reformulation/formulation. The Tick remains a credible and well-recognized brand and may provide a competitive edge for participating food manufacturers in the current market. The Tick programme is effective in influencing industry to reduce sodium in processed foods in New Zealand. The combined impact of the Tick and other NHF programmes has the potential to reduce population sodium intake and improve health outcomes.

Reduction of nitrous oxide emissions from partial nitrification process by using innovative carbon source (mannitol).

PubMed

Zhang, Xinwen; Wang, Xiaoqing; Zhang, Jian; Huang, Xiaoyu; Wei, Dong; Lan, Wei; Hu, Zhen

2016-10-01

The purpose of this study was to evaluate the effect of mannitol as carbon source on nitrogen removal and nitrous oxide (N2O) emission during partial nitrification (PN) process. Laboratory-scale PN sequencing batch reactors (SBRs) were operated with mannitol and sodium acetate as carbon sources, respectively. Results showed that mannitol could remarkably reduce N2O-N emission by 41.03%, without influencing the removal efficiency of NH4(+)-N. However, it has a significant influence on nitrite accumulation ratio (NAR) and TN removal, which were 19.97% and 13.59% lower than that in PN with sodium acetate, respectively. Microbial analysis showed that the introduction of mannitol could increase the abundance of bacteria encoding nosZ genes. In addition, anti-oxidant enzymes (T-SOD, POD and CAT) activities were significantly reduced and the dehydrogenase activity had an obvious increase in mannitol system, indicating that mannitol could alleviate the inhibition of N2O reductase (N2OR) activities caused by high NO2(-)-N concentration. Copyright © 2016 Elsevier Ltd. All rights reserved.

Caustic Recycling Pilot Unit to Separate Sodium from LLW at Hanford Site - 12279

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

Pendleton, Justin; Bhavaraju, Sai; Priday, George

As part of the Department of Energy (DOE) sponsored Advanced Remediation Technologies initiative, a scheme was developed to combine Continuous Sludge Leaching (CSL), Near-Tank Cesium Removal (NTCR), and Caustic Recycling Unit (CRU) using Ceramatec technology, into a single system known as the Pilot Near-Tank Treatment System (PNTTS). The Cesium (Cs) decontaminated effluent from the NTCR process will be sent to the caustic recycle process for recovery of the caustic which will be reused in another cycle of caustic leaching in the CSL process. Such an integrated mobile technology demonstration will give DOE the option to insert this process for sodiummore » management at various sites in Hanford, and will minimize the addition of further sodium into the waste tanks. This allows for recycling of the caustic used to remove aluminum during sludge washing as a pretreatment step in the vitrification of radioactive waste which will decrease the Low Level Waste (LLW) volume by as much as 39%. The CRU pilot process was designed to recycle sodium in the form of pure sodium hydroxide. The basis for the design of the 1/4 scale pilot caustic recycling unit was to demonstrate the efficient operation of a larger scale system to recycle caustic from the NTCR effluent stream from the Parsons process. The CRU was designed to process 0.28 liter/minute of NTCR effluent, and generate 10 M concentration of 'usable' sodium hydroxide. The proposed process operates at 40 deg. C to provide additional aluminum solubility and then recover the sodium hydroxide to the point where the aluminum is saturated at 40 deg. C. A system was developed to safely separate and vent the gases generated during operation of the CRU with the production of 10 M sodium hydroxide. Caustic was produced at a rate between 1.9 to 9.3 kg/hr. The CRU was located inside an ISO container to allow for moving of the unit close to tank locations to process the LLW stream. Actual tests were conducted with the NTCR effluent simulant from the Parsons process in the CRU. The modular CRU is easily scalable as a standalone system for caustic recycling, or for NTTS integration or for use as an In-Tank Treatment System to process sodium bearing waste to meet LLW processing needs at the Hanford site. The standalone pilot operation of the CRU to recycle sodium from NTCR effluent places the technology demonstration at TRL level 6. Multiple operations were performed with the CRU to process up to 500 gallons of the NTCR effluent and demonstrate an efficient separation of up to 70 % of the sodium without solids precipitation while producing 10 M caustic. Batch mode operation was conducted to study the effects of chemistry variation, establish the processing rate, and optimize the process operating conditions to recycle caustic from the NTCR effluent. The performance of the CRU was monitored by tracking the density parameter to control the concentration of caustic produced. Different levels of sodium were separated in tests from the effluent at a fixed operating current density and temperature. The voltage of the modules remained stable during the unit operation which demonstrated steady operation to separate sodium from the NTCR effluent. The sodium transfer current efficiency was measured in testing based on the concentration of caustic produced. Measurements showed a current efficiency of 99.8% for sodium transfer from the NTCR effluent to make sodium hydroxide. The sodium and hydroxide contents of the anolyte (NTCR feed) and catholyte (caustic product) were measured before and after each batch test. In two separate batch tests, samples were taken at different levels of sodium separation and analyzed to determine the stability of the NTCR effluent after sodium separation. The stability characteristics and changes in physical and chemical properties of the NTCR effluent chemistry after separation of sodium hydroxide as a function of storage time were evaluated. Parameters such as level of precipitated alumina, total alkalinity, analysis of Al, Na, K, Cs, Fe, OH, nitrate, nitrite, total dissolved and undissolved solids, viscosity, density, and other parameters of the NTCR effluent were measured. Changes in rheology and properties of NTCR stream to support downstream handling of the effluent after sodium separation was the basis for the analysis. The results show that the NTCR effluent is stable without the precipitation of aluminum hydroxide after 70% of the sodium was separated from the effluent. (authors)« less

Bicarbonate secretion and chloride absorption by rabbit cortical collecting ducts. Role of chloride/bicarbonate exchange.

PubMed Central

Star, R A; Burg, M B; Knepper, M A

1985-01-01

Cortical collecting ducts (CCD) from rabbits treated with deoxycorticosterone (DOC) actively secrete bicarbonate at high rates. To investigate the mechanism of bicarbonate secretion, we measured bicarbonate and chloride transport in CCD from rabbits treated with DOC for 9-24 d. Removal of chloride (replaced with gluconate) from both perfusate and bath inhibited bicarbonate secretion without changing transepithelial voltage. Removal of chloride only from the bath increased bicarbonate secretion, while removal of chloride only from the perfusate inhibited secretion. In contrast to the effect of removing chloride, removal of sodium from both the perfusate and bath (replacement with N-methyl-D-glucamine) did not change the rate of bicarbonate secretion. The rate of bicarbonate secretion equaled the rate of chloride absorption in tubules bathed with 0.1 mM ouabain to inhibit any cation-dependent chloride transport. Under these conditions, chloride absorption occurred against an electrochemical gradient. Removal of bicarbonate from both the perfusate and bath inhibited chloride absorption. Removal of bicarbonate only from the bath inhibited chloride absorption, while removal of bicarbonate from the lumen stimulated chloride absorption. We conclude that CCD from DOC-treated rabbits actively secrete bicarbonate and actively absorb chloride by an electroneutral mechanism involving 1:1 chloride/bicarbonate exchange. The process is independent of sodium. PMID:3930570

Silicate enhanced enzymatic dehairing: a new lime-sulfide-free process for cowhides.

PubMed

Saravanabhavan, Subramani; Thanikaivelan, Palanisamy; Rao, Jonnalagadda Raghava; Nair, Balachandran Unni

2005-05-15

A conventional dehairing process with sodium sulfide and lime is a major source of the pollution from the tanning industry. In other words, conventional dehairing processes degrade the hair to the extent that it cannot be recovered; thus, these processes become a major contributor to wastewater pollution. In this study, an attempt has been made to develop a lime and sulfide-free dehairing process using a commercial enzyme formulation with the activation of a silicate salt. A dip and pile method of application has been standardized. The amount of enzyme and sodium metasilicate has also been optimized based on complete removal of hair. Enhancement of enzyme activity by the addition of silicate has been demonstrated through activity measurements. Hair removal is found to be complete using scanning electron microscope analysis. Strength and bulk properties of the experimental leathers are comparable to that of control leathers. The process enjoys a significant reduction in chemical oxygen demand (COD) and total solids (TS) by 53 and 26%, respectively. More importantly, the application of enzyme for dehairing results in an 8% area increase in the final leather. Also, the process is proven to be techno-economically feasible.

Mechanistic investigation of industrial wastewater naphthenic acids removal using granular activated carbon (GAC) biofilm based processes.

PubMed

Islam, Md Shahinoor; Zhang, Yanyan; McPhedran, Kerry N; Liu, Yang; Gamal El-Din, Mohamed

2016-01-15

Naphthenic acids (NAs) found in oil sands process-affected waters (OSPW) have known environmental toxicity and are resistant to conventional wastewater treatments. The granular activated carbon (GAC) biofilm treatment process has been shown to effectively treat OSPW NAs via combined adsorption/biodegradation processes despite the lack of research investigating their individual contributions. Presently, the NAs removals due to the individual processes of adsorption and biodegradation in OSPW bioreactors were determined using sodium azide to inhibit biodegradation. For raw OSPW, after 28 days biodegradation and adsorption contributed 14% and 63% of NA removal, respectively. For ozonated OSPW, biodegradation removed 18% of NAs while adsorption reduced NAs by 73%. Microbial community 454-pyrosequencing of bioreactor matrices indicated the importance of biodegradation given the diverse carbon degrading families including Acidobacteriaceae, Ectothiorhodospiraceae, and Comamonadaceae. Overall, results highlight the ability to determine specific processes of NAs removals in the combined treatment process in the presence of diverse bacteria metabolic groups found in GAC bioreactors. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparison of amine-selective properties of weak and strong cation-exchangers.

PubMed

Stenholm, Ake; Lindgren, Helena; Shaffie, Juliana

2006-09-22

The capacity of several weak and strong cation-exchangers to adsorb 2-diethylaminoethanol (DEAE) and (2,3-hydroxypropyl) trimethylammonium chloride (HPMAC) from sodium-containing process water streams, and the ease of subsequently eluting the amines and regenerating the exchangers, were investigated. (2,3-hydroxypropyl) trimethylammonium chloride was enriched 40-fold compared with the initial amine/sodium-ratio in the bulk fluid by Amberlite IRC-50. The highest selectivity for 2-diethylaminoethanol (26-fold) was provided by Imac HP336. Neither of the selected strong cation-exchangers showed any selectivity towards 2-diethylaminoethanol, but they enriched (2,3-hydroxypropyl) trimethylammonium chloride approximately three to four fold. These findings suggest that weak cation-exchangers (WCX) could be readily used for the selective removal of these or similar amines from sodium-containing process waters.

Sulphate removal from sodium sulphate-rich brine and recovery of barium as a barium salt mixture.

PubMed

Vadapalli, Viswanath R K; Zvimba, John N; Mulopo, Jean; Motaung, Solly

2013-01-01

Sulphate removal from sodium sulphate-rich brine using barium hydroxide and recovery of the barium salts has been investigated. The sodium sulphate-rich brine treated with different dosages of barium hydroxide to precipitate barium sulphate showed sulphate removal from 13.5 g/L to less than 400 mg/L over 60 min using a barium to sulphate molar ratio of 1.1. The thermal conversion of precipitated barium sulphate to barium sulphide achieved a conversion yield of 85% using coal as both a reducing agent and an energy source. The recovery of a pure mixture of barium salts from barium sulphide, which involved dissolution of barium sulphide and reaction with ammonium hydroxide resulted in recovery of a mixture of barium carbonate (62%) and barium hydroxide (38%), which is a critical input raw material for barium salts based acid mine drainage (AMD) desalination technologies. Under alkaline conditions of this barium salt mixture recovery process, ammonia gas is given off, while hydrogen sulfide is retained in solution as bisulfide species, and this provides basis for ammonium hydroxide separation and recovery for reuse, with hydrogen sulfide also recoverable for further industrial applications such as sulfur production by subsequent stripping.

The Removal of Cu (II) from Aqueous Solution using Sodium Borohydride as a Reducing Agent

NASA Astrophysics Data System (ADS)

Sithole, N. T.; Ntuli, F.; Mashifana, T.

2018-03-01

The removal and recovery of metals from wastewater has been a subject of significant importance due the negative impact these toxic metals have on human health and the environment as a result of water and soil pollution. Increased use of the metals and chemicals in the process industries has resulted in generation of large quantity of effluents that contains high level of toxic metals and other pollutants. The objective of this work was to recover of Cu in its elemental form as metallic powder from aqueous solution using NaBH4 as a reducing agent. Reductive precipitation was achieved in a batch reactor at 65°C using Cu powder as a seeding material. This study also investigated the effect of concentration of sodium borohydride (NaBH4) as a reducing agent. The amount of NaBH4 was varied based on mole ratios which are 1:1, 1:0.25 and 1:0.1 to recover Cu from synthetic wastewater. The results obtained showed that sodium borohydride is an effective reducing agent to recover Cu from wastewater. The optimum concentration of NaBH4 that gives the best results the 1:1 molar ratio with over 99% Cu removal.

Removal of uranium and fluorine from wastewater by double-functional microsphere adsorbent of SA/CMC loaded with calcium and aluminum

NASA Astrophysics Data System (ADS)

Wu, Liping; Lin, Xiaoyan; Zhou, Xingbao; Luo, Xuegang

2016-10-01

A novel dual functional microsphere adsorbent of alginate/carboxymethyl cellulose sodium composite loaded with calcium and aluminum (SA/CMC-Ca-Al) is prepared by an injection device to remove fluoride and uranium, respectively, from fluoro-uranium mixed aqueous solution. Batch experiments are performed at different conditions: pH, temperature, initial concentration and contact time. The results show that the maximum adsorption amount for fluoride is 35.98 mg/g at pH 2.0, 298.15 K concentration 100 mg/L, while that for uranium is 101.76 mg/g at pH 4.0, 298.15 K concentration 100 mg/L. Both of the adsorption process could be well described by Langmuir model. The adsorption kinetic data is fitted well with pseudo-first-order model for uranium and pseudo-second-order model for fluoride. Thermodynamic parameters are also evaluated, indicating that the adsorption of uranium on SA/CMC-Ca-Al is a spontaneous and exothermic process, while the removal of fluoride is non-spontaneous and endothermic process. The mechanism of modification and adsorption process on SA/CMC-Ca-Al is characterized by FT-IR, SEM, EDX and XPS. The results show that Ca (II) and Al (III) are loaded on SA/CMC through ion-exchange of sodium of SA/CMC. The coordination reaction and ion-exchange happen during the adsorption process between SA/CMC-Ca-Al and uranium, fluoride. Results suggest that the SA/CMC-Ca-Al adsorbent has a great potential in removing uranium and fluoride from aqueous solution.

SIMPLIFIED SODIUM GRAPHITE REACTOR SYSTEM

DOEpatents

Dickinson, R.W.

1963-03-01

This patent relates to a nuclear power reactor comprising a reactor vessel, shielding means positioned at the top of said vessel, means sealing said reactor vessel to said shielding means, said vessel containing a quantity of sodium, a core tank, unclad graphite moderator disposed in said tank, means including a plurality of process tubes traversing said tank for isolating said graphite from said sodium, fuel elements positioned in said process tubes, said core tank being supported in spaced relation to the walls and bottom of said reactor vessel and below the level of said sodium, neutron shielding means positioned adjacent said core tank between said core tank and the walls of said vessel, said neutron shielding means defining an annuiar volume adjacent the inside wall of said reactor vessel, inlet plenum means below said core tank for providing a passage between said annular volume and said process tubes, heat exchanger means removably supported from the first-named shielding means and positioned in said annular volume, and means for circulating said sodium over said neutron shielding means down through said heat exchanger, across said inlet plenum and upward through said process tubes, said last-named means including electromagnetic pumps located outside said vessel and supported on said vessel wall between said heat exchanger means and said inlet plenum means. (AEC)

Techniques of Celloidin Removal From Temporal Bone Sections

PubMed Central

O’Malley, Jennifer T.; Burgess, Barbara J.; Jones, Diane D.; Adams, Joe C.; Merchant, Saumil N.

2009-01-01

Objectives We sought to determine whether the technique of celloidin removal influences the results of immunostaining in celloidin-embedded cochleae. Methods We compared four protocols of celloidin removal, including those using clove oil, acetone, ether-alcohol, and methanol saturated with sodium hydroxide. By optimally fixing our tissue (perfused mice), and keeping constant the fixative type (formalin plus acetic acid), fixation time (25 hours), and decalcification time (ethylenediaminetetraacetic acid for 7 days), we determined whether the technique of celloidin removal influenced the immunostaining results. Six antibodies were used with each removal method: prostaglandin D synthase, sodium, potassium adenosine triphosphatase (Na+,K+-ATPase), aquaporin 1, connective tissue growth factor, tubulin, and 200 kd neurofilament. Results Clove oil, acetone, and ether-alcohol resulted in incomplete removal of the celloidin, thereby negatively affecting the results of immunostaining. The methanol–sodium hydroxide method was effective in completely removing the celloidin; it produced the cleanest and most reproducible immunostaining for all six antibodies. Conclusions Freshly prepared methanol saturated with sodium hydroxide and diluted 1:2 with methanol was the best solvent for removing celloidin from mouse temporal bone sections, resulting in consistent and reproducible immunostaining with the six antibodies tested. PMID:19663375

Synthesis and Biological Evaluation of Brain-Specific Anti-RNA Viral Agents

DTIC Science & Technology

1990-03-31

water (200 iL). It was dried over sodium sulfate and the solvent was removed under reduced pressure. The resulting oil was dissolved in a minimum...The organic extracts were washed with NaHCO3 (2 x 200 mL), water (200 mL) and dried over sodium sulfate . The solvent was removed in vacuo and the...chloroform. The combined organic extracts were washed with 2 x 250 mL cold deionised water, dried ( sodium sulfate ) and removed under reduced pressure to

PROCESS FOR TREATING VOLATILE METAL FLUORIDES

DOEpatents

Rudge, A.J.; Lowe, A.J.

1957-10-01

This patent relates to the purification of uranium hexafluoride, made by reacting the metal or its tetrafluoride with fluorine, from the frequently contained traces of hydrofluoric acid. According to the present process, UF/sub 6/ containing as an impurity a small amount of hydrofluoric acid, is treated to remove such impurity by contact with an anhydrous alkali metal fluoride such as sodium fluoride. In this way a non-volatile complex containing hydrofluoric acid and the alkali metal fluoride is formed, and the volatile UF /sub 6/ may then be removed by distillation.

Numerical simulation of submicron particles formation by condensation at coals burning

NASA Astrophysics Data System (ADS)

Kortsenshteyn, N. M.; Petrov, L. V.

2017-11-01

The thermodynamic analysis of the composition of the combustion products of 15 types of coals was carried out with consideration for the formation of potassium and sodium aluminosilicates and solid and liquid slag removal. Based on the results of the analysis, the approximating temperature dependences of the concentrations of condensed components (potassium and sodium sulfates) were obtained for the cases of two-phase and single-phase equilibriums; conclusions on the comparative influence of solid and liquid slag removal on the probability of the formation of submicron particles on the combustion of coals were made. The found dependences was make it possible to perform a numerical simulation of the bulk condensation of potassium and sodium sulfate vapors upon the cooling of coal combustion products in a process flow. The number concentration and size distribution of the formed particles have been determined. Agreement with experimental data on the fraction composition of particles has been reached at a reasonable value of a free parameter of the model.

Cassava stillage and its anaerobic fermentation liquid as external carbon sources in biological nutrient removal.

PubMed

Bu, Fan; Hu, Xiang; Xie, Li; Zhou, Qi

2015-04-01

The aim of this study was to investigate the effects of one kind of food industry effluent, cassava stillage and its anaerobic fermentation liquid, on biological nutrient removal (BNR) from municipal wastewater in anaerobic-anoxic-aerobic sequencing batch reactors (SBRs). Experiments were carried out with cassava stillage supernatant and its anaerobic fermentation liquid, and one pure compound (sodium acetate) served as an external carbon source. Cyclic studies indicated that the cassava by-products not only affected the transformation of nitrogen, phosphorus, poly-β-hydroxyalkanoates (PHAs), and glycogen in the BNR process, but also resulted in higher removal efficiencies for phosphorus and nitrogen compared with sodium acetate. Furthermore, assays for phosphorus accumulating organisms (PAOs) and denitrifying phosphorus accumulating organisms (DPAOs) demonstrated that the proportion of DPAOs to PAOs reached 62.6% (Day 86) and 61.8% (Day 65) when using cassava stillage and its anaerobic fermentation liquid, respectively, as the external carbon source. In addition, the nitrate utilization rates (NURs) of the cassava by-products were in the range of 5.49-5.99 g N/(kg MLVSS⋅h) (MLVSS is mixed liquor volatile suspended solids) and 6.63-6.81 g N/(kg MLVSS⋅h), respectively. The improvement in BNR performance and the reduction in the amount of cassava stillage to be treated in-situ make cassava stillage and its anaerobic fermentation liquid attractive alternatives to sodium acetate as external carbon sources for BNR processes.

Cassava stillage and its anaerobic fermentation liquid as external carbon sources in biological nutrient removal*

PubMed Central

Bu, Fan; Hu, Xiang; Xie, Li; Zhou, Qi

2015-01-01

The aim of this study was to investigate the effects of one kind of food industry effluent, cassava stillage and its anaerobic fermentation liquid, on biological nutrient removal (BNR) from municipal wastewater in anaerobic-anoxic-aerobic sequencing batch reactors (SBRs). Experiments were carried out with cassava stillage supernatant and its anaerobic fermentation liquid, and one pure compound (sodium acetate) served as an external carbon source. Cyclic studies indicated that the cassava by-products not only affected the transformation of nitrogen, phosphorus, poly-β-hydroxyalkanoates (PHAs), and glycogen in the BNR process, but also resulted in higher removal efficiencies for phosphorus and nitrogen compared with sodium acetate. Furthermore, assays for phosphorus accumulating organisms (PAOs) and denitrifying phosphorus accumulating organisms (DPAOs) demonstrated that the proportion of DPAOs to PAOs reached 62.6% (Day 86) and 61.8% (Day 65) when using cassava stillage and its anaerobic fermentation liquid, respectively, as the external carbon source. In addition, the nitrate utilization rates (NURs) of the cassava by-products were in the range of 5.49–5.99 g N/(kg MLVSS∙h) (MLVSS is mixed liquor volatile suspended solids) and 6.63–6.81 g N/(kg MLVSS∙h), respectively. The improvement in BNR performance and the reduction in the amount of cassava stillage to be treated in-situ make cassava stillage and its anaerobic fermentation liquid attractive alternatives to sodium acetate as external carbon sources for BNR processes. PMID:25845364

Improvements to in-line desalting of oligosaccharides separated by high-pH anion exchange chromatography with pulsed amperometric detection.

PubMed

Thayer, J R; Rohrer, J S; Avdalovic, N; Gearing, R P

1998-02-15

High-pH anion exchange chromatography with pulsed amperometric detection (HPAEC/PAD) (1) is routinely used to separate neutral and charged oligosaccharides differing by branch, linkage, and positional isomerism. Oligosaccharides are eluted in 0.1 M NaOH with gradients of sodium acetate (up to 0.25 M). Analyses of HPAEC/PAD-purified oligosaccharides generally require neutralization and removal of eluent salts. To facilitate the process, we designed and produced a cation-exchange system to remove sodium ions (Na+) from the eluent after oligosaccharide detection [the Carbohydrate Membrane Desalter (CMD), with a volatile regenerant]. Exchange of >99.5% of eluent Na+ for hydronium ions (H3O+) within the CMD generates dilute acetic acid (removable by vacuum evaporation). The exchange process desalts up to 0.35 M Na+ at 1.0 ml/min. Oligosaccharides collected after on-line desalting, evaporated and resuspended in their original volume of deionized water contained < or = 350 muM residual Na+ when the eluting sodium concentration was 300 mM. This represents a desalting efficiency of >99.8%. Recovery of neutral and sialylated oligosaccharides under these conditions ranged from 75 to 100%. With the CMD system and postcollection evaporation, HPAEC/PAD can purify oligosaccharides ready for further characterization. As a proof test, oligosaccharides from a human monoclonal antibody were separated by HPAEC/PAD, desalted with the CMD system, dried, and analyzed by matrix-assisted laser desorption-ionization, time-of-flight mass spectrometry. Copyright 1998 Academic Press.

Scanning Electron Microscopic Evaluation of Root Canal Irrigation with Saline, Sodium Hypochlorite, and Citric Acid,

DTIC Science & Technology

1983-12-01

with six different irrigation regimens. Sodium hypochlorite (NaOCl) was significantly more effective than citric acid in "* removing superficial...EVALUATION OF ROOT CANAL IRRIGATION WITH SALINE, SODIUM HYPOCHLORITE , AND CITRIC ACID 4 *J. Craig Baumgartner, D.D.S., M.S. • **Carolyn M. Brown, D.D.S., M.S...preparation with six different irrigation regimens. Sodium hypochlorite (NaOCl) was significantly more effective than citric acid in removing superficial

MSG test report: removal of residual sodium. [LMFBR

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

Harty, R.B.

1974-03-08

This report presents the results of cleaning activities performed to remove residual sodium from the AI Modular Steam Generator. A description of the cleaning loop, cleaning procedure, results, and visual inspection are included.

Preliminary Design of Critical Function Monitoring System of PGSFR

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

NONE

2015-07-01

A PGSFR (Prototype Gen-IV Sodium-cooled Fast Reactor) is under development at Korea Atomic Energy Research Institute. A critical function monitoring system of the PGSFR is preliminarily studied. The functions of CFMS are to display critical plant variables related to the safety of the plant during normal and accident conditions and guide the operators corrective actions to keep the plant in a safe condition and mitigate the consequences of accidents. The minimal critical functions of the PGSFR are composed of reactivity control, reactor core cooling, reactor coolant system integrity, primary heat transfer system(PHTS) heat removal, sodium water reaction mitigation, radiation controlmore » and containment conditions. The variables and alarm legs of each critical function of the PGSFR are as follows; - Reactivity control: The variables of reactivity control function are power range neutron flux instrumentation, intermediate range neutron flux instrumentation, source range neutron flux instrumentation, and control rod bottom contacts. The alarm leg to display the reactivity controls consists of status of control drop malfunction, high post trip power and thermal reactivity addition. - Reactor core cooling: The variables are PHTS sodium level, hot pool temperature of PHTS, subassembly exit temperature, cold pool temperature of the PHTS, PHTS pump current, and PHTS pump breaker status. The alarm leg consists of high core delta temperature, low sodium level of the PHTS, high subassembly exit temperature, and low PHTS pump load. - Reactor coolant system integrity: The variables are PHTS sodium level, cover gas pressure, and safeguard vessel sodium level. The alarm leg is composed of low sodium level of PHTS, high cover gas pressure and high sodium level of the safety guard vessel. - PHTS heat removal: The variables are PHTS sodium level, hot pool temperature of PHTS, core exit temperature, cold pool temperature of the PHTS, flow rate of passive residual heat removal system, flow rate of active residual heat removal system, and temperatures of air heat exchanger temperature of residual heat removal systems. The alarm legs are composed of two legs of a 'passive residual heat removal system not cooling' and 'active residual heat removal system not cooling'. - Sodium water reaction mitigation: The variables are intermediate heat transfer system(IHTS) pressure, pressure and temperature and level of sodium dump tank, the status of rupture disk, hydrogen concentration in IHTS and direct variable of sodium-water-reaction measure. The alarm leg consists of high IHTS pressure, the status of sodium water reaction mitigation system and the indication of direct measure. - Radiation control: The variables are radiation of PHTS, radiation of IHTS, and radiation of containment purge. The alarm leg is composed of high radiation of PHTS and IHTS, and containment purge system. - Containment condition: The variables are containment pressure, containment isolation status, and sodium fire. The alarm leg consists of high containment pressure, status of containment isolation and status of sodium fire. (authors)« less

METHOD OF SEPARATING FISSION PRODUCTS FROM FUSED BISMUTH-CONTAINING URANIUM

DOEpatents

Wiswall, R.H.

1958-06-24

A process is described for removing metal selectively from liquid metal compositions. The method effects separation of flssion product metals selectively from dilute solution in fused bismuth, which contains uraniunn in solution without removal of more than 1% of the uranium. The process comprises contacting the fused bismuth with a fused salt composition consisting of sodium, potassium and lithium chlorides, adding to fused bismuth and molten salt a quantity of bismuth chloride which is stoichiometrically required to convert the flssion product metals to be removed to their chlorides which are more stable in the fused salt than in the molten metal and are, therefore, preferentially taken up in the fused salt phase.

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

Chassery, A.; Universite de Toulouse, Laboratoire de Genie Chimique, Toulouse; CNRS, Laboratoire de Genie Chimique, Toulouse

Within the framework of the dismantling of fast breeder reactors in France several processes are under investigation regarding sodium disposal. One of them, called ELA (radioactive sodium waste treatment process), is based on the implementation of the sodium-water reaction, in a controlled and progressive way, to remove residual sodium. This sodium contains impurities such as sodium hydride, sodium oxide and tritiated sodium hydride. The hydrolysis of these various chemical species leads to the production of a liquid effluent, mainly composed of an aqueous solution of sodium hydroxide, and a gaseous effluent, mainly composed of nitrogen (inert gas), hydrogen and steam.more » The tritium is distributed between these effluents, and, within the gaseous effluent, according to its forms HT and HTO (tritiated water). HTO being 10,000 times more radio-toxic than HT, a precise knowledge of the mechanisms governing the phase distribution of tritium is necessary. This paper presents the first experimental results from a parametric study on the tritium distribution between the various effluents generated during hydrolysis operations. A series of experiments have been performed in order to study the influence of water flow rate, argon flow rate, initial mass and specific activity of the hydrolyzed sodium sample. An important influence of the total tritium concentration in the hydrolyzed sample has been highlighted. As for the phenomena suspected to be responsible for the phase change of tritiated water, in the studied range of parameters, vaporization induced by the heat of reactions seems to be dominant over the evaporation induced by the inert gas flow rate.« less

Sodium Heat Pipe Module Processing For the SAFE-100 Reactor Concept

NASA Technical Reports Server (NTRS)

Martin, James; Salvail, Pat

2003-01-01

To support development and hardware-based testing of various space reactor concepts, the Early Flight Fission-Test Facility (EFF-TF) team established a specialized glove box unit with ancillary systems to handle/process alkali metals. Recently, these systems have been commissioned with sodium supporting the fill of stainless steel heat pipe modules for use with a 100 kW thermal heat pipe reactor design. As part of this effort, procedures were developed and refined to govern each segment of the process covering: fill, leak check, vacuum processing, weld closeout, and final "wet in". A series of 316 stainless steel modules, used as precursors to the actual 321 stainless steel modules, were filled with 35 +/- 1 grams of sodium using a known volume canister to control the dispensed mass. Each module was leak checked to less than10(exp -10) std cc/sec helium and vacuum conditioned at 250 C to assist in the removal of trapped gases. A welding procedure was developed to close out the fill stem preventing external gases from entering the evacuated module. Finally the completed modules were vacuum fired at 750 C allowing the sodium to fully wet the internal surface and wick structure of the heat pipe module.

Sodium Heat Pipe Module Processing For the SAFE-100 Reactor Concept

NASA Astrophysics Data System (ADS)

Martin, James; Salvail, Pat

2004-02-01

To support development and hardware-based testing of various space reactor concepts, the Early Flight Fission-Test Facility (EFF-TF) team established a specialized glove box unit with ancillary systems to handle/process alkali metals. Recently, these systems have been commissioned with sodium supporting the fill of stainless steel heat pipe modules for use with a 100 kW thermal heat pipe reactor design. As part of this effort, procedures were developed and refined to govern each segment of the process covering: fill, leak check, vacuum processing, weld closeout, and final ``wet in''. A series of 316 stainless steel modules, used as precursors to the actual 321 stainless steel modules, were filled with 35 +/-1 grams of sodium using a known volume canister to control the dispensed mass. Each module was leak checked to <10-10 std cc/sec helium and vacuum conditioned at 250 °C to assist in the removal of trapped gases. A welding procedure was developed to close out the fill stem preventing external gases from entering the evacuated module. Finally the completed modules were vacuum fired at 750 °C allowing the sodium to fully wet the internal surface and wick structure of the heat pipe module.

Sodium metasilicate based fiber opening for greener leather processing.

PubMed

Saravanabhavan, Subramani; Thanikaivelan, Palanisamy; Rao, Jonnalagadda Raghava; Nair, Balachandran Unni; Ramasamit, Thirumalachari

2008-03-01

Growing environmental regulations propound the need for a transformation in the current practice of leather making. The conventional dehairing and fiber opening process results in high negative impact on the environment because of its uncleanliness. This process accounts for most of the biochemical oxygen demand and chemical oxygen demand in tannery wastewater and generation of H2S gas. Hence, this study explores the use of a biological material and a nontoxic chemical for performing the above process more cleanly. In this study, the dehairing and fiber opening processes has been designed using enzyme and sodium metasilicate. The amount of sodium metasilicate required for fiber opening is standardized through the removal of proteoglycan, increase in weight, and bulk properties of leathers. It has been found that the extent of opening up of fiber bundles is comparable to that of conventionally processed leathers using a 2% sodium metasilicate solution. This has been substantiated through scanning electron microscopic analysis and softness measurements. The presence of silica in the crust leather enhances the bulk properties of the leather. This has been confirmed from the energy dispersive X-ray analysis. Performance of the leathers is shown to be on par with conventionally processed leathers through physical and hand evaluation. The process also exhibits significant reduction in chemical oxygen demand and total solid loads by 55 and 24%, respectively. Further, this newly developed process seems to be economically beneficial.

Removal of caffeine from industrial wastewater using Trichosporon asahii.

PubMed

Lakshmi, V; Das, Nilanjana

2013-07-01

Caffeine (1,3,7-trimethylxanthine), a natural alkaloid present mainly in tea and coffee products has been suggested as an environmental pollutant. Decaffeination is an important process for the removal of caffeine from coffee industrial wastes. In the present study, caffeine removal (through degradation) by yeast isolate, Trichosporon asahii immobilized on various conventional matrices (sodium alginate, carboxymethyl cellulose, chitosan, agar and agarose) was investigated using the method of entrapment. The biofilm forming ability of T. asahii was monitored by atomic force microscopy and scanning electron microscopy. Exopolysaccharide produced by T asahii biofilm was characterized by FT-IR spectroscopy and HPLC analysis. Caffeine removal from coffee processing industrial effluent was found to be 75 and 80 % by alginate immobilized yeast and yeast biofilm formed on gravels over a period of 48 hr in batch mode. Effectiveness of the process was also tested involving the continuous--flow column studies.

Use of amphiphilic triblock copolymers for enhancing removal efficiency of organic pollutant from contaminated media

NASA Astrophysics Data System (ADS)

Lee, Jun Hyup; Lee, Byungsun; Son, Intae; Kim, Jae Hong; Kim, Chunho; Yoo, Ji Yong; Wu, Jong-Pyo; Kim, Younguk

2015-11-01

We have studied amphiphilic triblock copolymers poly(ethylene glycol)- b-poly(propylene glycol)- b-poly(ethylene glycol) (PEG- b-PPG- b-PEG) and poly(propylene glycol)- b-poly(ethylene glycol)- b-poly(propylene glycol) (PPG- b-PEG- b-PPG) as possible substitutes for sodium dodecyl sulfate as anionic surfactants for the removal of hydrophobic contaminants. The triblock copolymers were compared with sodium dodecyl sulfate in terms of their abilities to remove toluene as hydrophobic contaminant in fuel, and the effects of polymer structure, PEG content, and concentration were studied. The PEG- b-PPG- b-PEG copolymer containing two hydrophilic PEG blocks was more effective for the removal of hydrophobic contaminant at extremely high concentration. We also measured the removal capabilities of the triblock copolymers having various PEG contents and confirmed that removal capability was greatest at 10% PEG content regardless of polymer structure. As with sodium dodecyl sulfate, the removal efficiency of a copolymer has a positive correlation with its concentration. Finally, we proposed the amphiphilic triblock copolymer of PPG- b-PEG- b-PPG bearing 10% PEG content that proved to be the most effective substitute for sodium dodecyl sulfate.

Removal of Sulfur Dioxide from Flue Gas Using the Sludge Sodium Humate

PubMed Central

Hu, Guoxin

2013-01-01

This study shows the ability of sodium humate from alkaline treatment sludge on removing sulfur dioxide (SO2) in the simulated flue gas. Experiments were conducted to examine the effect of various operating parameters, like the inlet SO2 concentration or temperature or O2, on the SO2 absorption efficiency and desulfurization time in a lab-scale bubbling reactor. The sludge sodium humate in the supernatant after alkaline sludge treatment shows great performance in SO2 absorption, and such efficiency can be maintained above 98% with 100 mL of this absorption solution at 298 K (flue gas rate of 0.12 m3/h). The highest SO2 absorption by 1.63 g SHA-Na is 0.946 mmol in the process, which is translated to 0.037 g SO2 g−1 SHA-Na. The experimental results indicate that the inlet SO2 concentration slightly influences the SO2 absorption efficiency and significantly influences the desulfurization time. The pH of the absorption solution should be above 3.5 in this process in order to make an effective desulfurization. The products of this process were characterized by Fourier transform infrared spectroscopy and X-ray diffraction. It can be seen that the desulfurization products mainly contain sludge humic acid sediment, which can be used as fertilizer components. PMID:24453875

Effect of time on dyeing wastewater treatment

NASA Astrophysics Data System (ADS)

Ye, Tingjin; Chen, Xin; Xu, Zizhen; Chen, Xiaogang; Shi, Liang; He, Lingfeng; Zhang, Yongli

2018-03-01

The preparation of carboxymethylchitosan wrapping fly-ash adsorbent using high temperature activated fly ash and sodium carboxymethyl chitosan (CWF), as with the iron-carbon micro-electrolysis process simulation and actual printing and dyeing wastewater. The effects of mixing time and static time on decolorization ratio, COD removing rate and turbidness removing rate were investigated. The experimental results show that the wastewater stirring times on the decolorization rate and COD removal rate and turbidity removal rate influence, with increasing of the stirring time, three showed a downward trend, and reached the peak at 10 min time; wastewater time on the decolorization ratio and COD removing efficiency and turbidness removing rate influence, along with standing time increase, three who declined and reached the maximum in 30min time.

REMOVAL OF SYNTHETIC ORGANIC CHEMICAL CONTAMINANTS IN DRINKING WATER: RASCO, INC. ADVANCED SIMULTANEOUS OXIDATION PROCESS (ASOP)

EPA Science Inventory

The RASco, Inc. ASOP Drinking Water Treatment Module was tested at NSF’s Laboratory for the reduction of the following chemicals of concern: aldicarb, benzene, carbofuran, chloroform, dichlorvos, dicrotophos, methomyl, mevinphos, nicotine, oxamyl, paraquat, phorate, sodium fluor...

Advanced treatment of sodium dithionite wastewater using the combination of coagulation, catalytic ozonation, and SBR.

PubMed

Zou, Xiao-Ling

2017-10-01

A combined process of coagulation-catalytic ozonation-anaerobic sequencing batch reactor (ASBR)-SBR was developed at lab scale for treating a real sodium dithionite wastewater with an initial chemical oxygen demand (COD) of 21,760-22,450 mg/L. Catalytic ozonation with the prepared cerium oxide (CeO 2 )/granular activated carbon catalyst significantly enhances wastewater biodegradability and reduces wastewater microtoxicity. The results show that, under the optimum conditions, the removal efficiencies of COD and suspended solids are averagely 99.3% and 95.6%, respectively, and the quality of final effluent can meet the national discharge standard of China. The coagulation and ASBR processes remove a considerable proportion of organic matter, while the SBR plays an important role in post-polish of final effluent. The ecotoxicity of the wastewater is greatly reduced after undergoing the hybrid treatment. This work demonstrates that the hybrid system has the potential to be applied for the advanced treatment of high-strength industrial wastewater.

Investigation of the chemical pathway of gaseous nitrogen dioxide formation during flue gas desulfurization with dry sodium bicarbonate injection

NASA Astrophysics Data System (ADS)

Stein, Antoinette Weil

The chemical reaction pathway for the viable flue gas desulfurization process, dry sodium bicarbonate injection, was investigated to mitigate undesirable plume discoloration. Based on a foundation of past findings, a simplified three-step reaction pathway was hypothesized for the formation of the plume-discoloring constituent, NO2. As the first step, it was hypothesized that sodium sulfite formed by sodium bicarbonate reaction with flue gas SO 2. As the second step, it was hypothesized that sodium nitrate formed by sodium sulfite reaction with flue gas NO. And as the third step, it was hypothesized that NO2 and sodium sulfate formed by sodium nitrate reaction with SO2. The second and third hypothesized steps were experimentally investigated using an isothermal fixed bed reactor. As reported in the past, technical grade sodium sulfite was found to be un-reactive with NO and O2. Freshly prepared sodium sulfite, maintained unexposed to moist air, was shown to react with NO and O2 resulting in a mixture of sodium nitrite and sodium nitrate together with a significant temperature rise. This reaction was found to proceed only when oxygen was present in the flue gas. As reported in the past, technical grade sodium nitrate was shown to be un-reactive with SO2. But freshly formed sodium nitrate kept unexposed to humidity was found to be reactive with SO2 and O 2 resulting in the formation of NO2 and sodium sulfate polymorphic Form I. The NO2 formation by this reaction was shown to be temperature dependent with maximum formation at 175°C. Plume mitigation methods were studied based on the validated three-step reaction pathway. Mitigation of NO2 was exhibited by limiting oxygen concentration in the flue gas to a level below 5%. It was also shown that significant NO2 mitigation was achieved by operating below 110°C or above 250°C. An innovative NO2 mitigation method was patented as a result of the findings of this study. The patented process incorporated a process step of sodium sulfite injection to remove flue gas NO prior to sodium bicarbonate injection.

Method and apparatus for removing iodine from a nuclear reactor coolant

DOEpatents

Cooper, Martin H.

1980-01-01

A method and apparatus for removing iodine-131 and iodine-125 from a liquid sodium reactor coolant. Non-radioactive iodine is dissolved in hot liquid sodium to increase the total iodine concentration. Subsequent precipitation of the iodine in a cold trap removes both the radioactive iodine isotopes as well as the non-radioactive iodine.

Diatomite Modified Immobilized Delftia sp. for the Bio-Abiotic Removal of Antibiotics Amoxicillin in the Aqueous System

NASA Astrophysics Data System (ADS)

Gao, Lijuan; Sun, Jing; Guan, Kai; Shen, Tingting; Wang, Xikui

2017-05-01

Diatomite modified sodium alginate (Si/SA) immobilized Delftia sp. A2(2011) (STT01) was applied to degrade amoxicillin. The immobilized pellets provided a direct and visual probe for the degradation process due to their intrinsic bright colour. The results demonstrated that 100% of amoxicillin and 68.5% of CODcr removal were achieved after 72 h, comparing with the cases of sodium alginate (SA) system (81.2%, 46.9%) and the free cells system (60.5%, 35.5%). The degradation kinetics was in good agreement with Michaelis-Menten equation. The maximum rate (Vm ) and Michaelis constant (Km ) were calculated as 9.09 mg L-1 h-1 and 228 mg L-1, respectively. The results further revealed that diatomite not only acted as immobilization support to improve the mechanical strength and lifetime of the pellets but also as absorbent to promote the treatment efficiency. Therefore, both enzymatic catalysis and chemisorption were responsible for the removal of amoxicillin.

What can we do with sodium retention in peritoneal dialysis patients?

PubMed

Lichodziejewska-Niemierko, M

2008-01-01

Salt intake in XXI century in an average person exceeds 10-15 grams per day. The key organ responsible for sodium regulation is kidney and renal failure patients present with positive sodium balance. In peritoneal dialysis (PD) patients rising hypertension is often connected with volume overload and sodium retention. The reasons for inadequate sodium removal in PD patients are: too small gradient between standard 134 mmol/l sodium PD solutions, sodium seiving effect and lack of residual renal function. APD patients are at higher risk of sodium overload in comparison to CAPD ones. As it has been shown that a degree of sodium removal correlates with survival, sodium management appears to be crucial in these patients. The concept of low sodium solutions has been developed over the years with single-dwell ultra-low solutions and recently with low sodium balance solution given as a continuous treatment in CAPD patients. Preliminary results show that low sodium solutions may be a safe and viable option of treatment of PD patients with sodium and fluid overload.

Coupling biofiltration process and electrocoagulation using magnesium-based anode for the treatment of landfill leachate.

PubMed

Oumar, Dia; Patrick, Drogui; Gerardo, Buelna; Rino, Dubé; Ihsen, Ben Salah

2016-10-01

In this research paper, a combination of biofiltration (BF) and electrocoagulation (EC) processes was used for the treatment of sanitary landfill leachate. Landfill leachate is often characterized by the presence of refractory organic compounds (BOD/COD < 0.13). BF process was used as secondary treatment to remove effectively ammonia nitrogen (N-NH4 removal of 94%), BOD (94% removed), turbidity (95% removed) and phosphorus (more than 98% removed). Subsequently, EC process using magnesium-based anode was used as tertiary treatment. The best performances of COD and color removal from landfill leachate were obtained by applying a current density of 10 mA/cm(2) through 30 min of treatment. The COD removal reached 53%, whereas 85% of color removal was recorded. It has been proved that the alkalinity had a negative effect on COD removal during EC treatment. COD removal efficiencies of 52%, 41% and 27% were recorded in the presence of 1.0, 2.0 and 3.0 g/L of sodium bicarbonate (NaHCO3), respectively. Hydroxide ions produced at the cathode electrode reacted with the bicarbonate ions to form carbonates. The presence of bicarbonates in solution hampered the increase in pH, so that the precipitation of magnesium hydroxides could not take place to effectively remove organic pollutants. Copyright © 2016 Elsevier Ltd. All rights reserved.

DELAYED TOOTH REPLANTATION AFTER ROOT SURFACE TREATMENT WITH SODIUM HYPOCHLORITE AND SODIUM FLUORIDE: HISTOMORPHOMETRIC ANALYSIS IN RATS

PubMed Central

Sottovia, André Dotto; Sonoda, Celso Koogi; Poi, Wilson Roberto; Panzarini, Sônia Regina; Lauris, José Roberto Pereira

2006-01-01

In cases of delayed tooth replantation, non-vital periodontal ligament remnants have been removed with sodium hypochlorite in an attempt to control root resorption. Nevertheless, reports of its irritating potential in contact with the alveolar connective tissue have been described. Therefore, this study evaluated the healing process on delayed replantation of rat teeth, after periodontal ligament removal by different treatment modalities. Twenty-four rats, assigned to 3 groups (n=8), had their upper right incisor extracted and left on the workbench for desiccation during 60 min. Afterwards, the teeth in group I were immersed in saline for 2 min. In group II, root surfaces were scrubbed with gauze soaked in saline for 2 min; and in group III, scrubbing was done with gauze soaked in 1% sodium hypochlorite solution. Thereafter, root surfaces were etched with 37% phosphoric acid and immersed in 2% acidulate-phosphate sodium fluoride solution, at pH 5.5. Root canals were filled with a calcium hydroxide-based paste and the teeth were replanted. The animals were sacrificed 60 days postoperatively and the pieces containing the replanted teeth were processed and paraffin-embedded. Semi-serial transversally sections were obtained from the middle third of the root and stained with hematoxylin and eosin for histomorphometric analysis. Data were analyzed statistically using Kruskal-Wallis and Dunn's tests. The results showed that root structure and cementum extension were more affected by resorption in group III (p<0.05). All groups were affected by root resorption but the treatment performed in group III was the least effective for its control. The treatment accomplished in groups I and II yielded similar results to each other. PMID:19089038

Delayed tooth replantation after root surface treatment with sodium hypochlorite and sodium fluoride: histomorphometric analysis in rats.

PubMed

Sottovia, André Dotto; Sonoda, Celso Koogi; Poi, Wilson Roberto; Panzarini, Sônia Regina; Lauris, José Roberto Pereira

2006-04-01

In cases of delayed tooth replantation, non-vital periodontal ligament remnants have been removed with sodium hypochlorite in an attempt to control root resorption. Nevertheless, reports of its irritating potential in contact with the alveolar connective tissue have been described. Therefore, this study evaluated the healing process on delayed replantation of rat teeth, after periodontal ligament removal by different treatment modalities. Twenty-four rats, assigned to 3 groups (n=8), had their upper right incisor extracted and left on the workbench for desiccation during 60 min. Afterwards, the teeth in group I were immersed in saline for 2 min. In group II, root surfaces were scrubbed with gauze soaked in saline for 2 min; and in group III, scrubbing was done with gauze soaked in 1% sodium hypochlorite solution. Thereafter, root surfaces were etched with 37% phosphoric acid and immersed in 2% acidulate-phosphate sodium fluoride solution, at pH 5.5. Root canals were filled with a calcium hydroxide-based paste and the teeth were replanted. The animals were sacrificed 60 days postoperatively and the pieces containing the replanted teeth were processed and paraffin- embedded. Semi-serial transversally sections were obtained from the middle third of the root and stained with hematoxylin and eosin for histomorphometric analysis. Data were analyzed statistically using Kruskal-Wallis and Dunn's tests. The results showed that root structure and cementum extension were more affected by resorption in group III (p<0.05). All groups were affected by root resorption but the treatment performed in group III was the least effective for its control. The treatment accomplished in groups I and II yielded similar results to each other.

Process for preparing chemically modified micas for removal of cesium salts from aqueous solution

DOEpatents

Yates, Stephen Frederic; DeFilippi, Irene; Gaita, Romulus; Clearfield, Abraham; Bortun, Lyudmila; Bortun, Anatoly

2000-09-05

A chemically modified mica composite formed by heating a trioctahedral mica in an aqueous solution of sodium chloride having a concentration of at least 1 mole/liter at a temperature greater than 180 degrees Centigrade for at least 20 hours, thereby replacing exchangeable ions in the mica with sodium. Formation is accomplished at temperatures and pressures which are easily accessed by industrial equipment. The reagent employed is inexpensive and non-hazardous, and generates a precipitate which is readily separated from the modified mica.

Mildew remover poisoning

MedlinePlus

Poisonous ingredients include: Detergents Hydrogen peroxide Sodium hypochlorite Sodium perborate Sodium percarbonate ... for recovery. Swallowing such poisons can have severe effects on many parts of the body. The ultimate ...

ELECTRODIALYSIS AS A TECHNIQUE FOR EXTENDING ELECTROLESS NICKEL BATH LIFE-IMPROVING SELECTIVITY AND REDUCING LOSSES OF VALUABLE BATH COMPONENTS

EPA Science Inventory

Over the last decade electrodialysis has emerged as an effective technique for removing accumulated reactant counterions (sodium and sulfate) and reaction products (orthophosphite) that interfere with the electroless nickel plating process, thus extending bath life by up to 50 me...

POST-OPERATIONAL TREATMENT OF RESIDUAL NA COOLLANT IN EBR-2 USING CARBONATION

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

Sherman, S.; Knight, C.

2011-03-08

At the end of 2002, the Experimental Breeder Reactor Two (EBR-II) facility became a U.S. Resource Conservation and Recovery Act (RCRA) permitted site, and the RCRA permit1 compelled further treatment of the residual sodium in order to convert it into a less reactive chemical form and remove the by-products from the facility, so that a state of RCRA 'closure' for the facility may be achieved (42 U.S.C. 6901-6992k, 2002). In response to this regulatory driver, and in recognition of project budgetary and safety constraints, it was decided to treat the residual sodium in the EBR-II primary and secondary sodium systemsmore » using a process known as 'carbonation.' In early EBR-II post-operation documentation, this process is also called 'passivation.' In the carbonation process (Sherman and Henslee, 2005), the system containing residual sodium is flushed with humidified carbon dioxide (CO{sub 2}). The water vapor in the flush gas reacts with residual sodium to form sodium hydroxide (NaOH), and the CO{sub 2} in the flush gas reacts with the newly formed NaOH to make sodium bicarbonate (NaHCO{sub 3}). Hydrogen gas (H{sub 2}) is produced as a by-product. The chemical reactions occur at the exposed surface of the residual sodium. The NaHCO{sub 3} layer that forms is porous, and humidified carbon dioxide can penetrate the NaHCO{sub 3} layer to continue reacting residual sodium underneath. The rate of reaction is controlled by the thickness of the NaHCO{sub 3} surface layer, the moisture input rate, and the residual sodium exposed surface area. At the end of carbonation, approximately 780 liters of residual sodium in the EBR-II primary tank ({approx}70% of original inventory), and just under 190 liters of residual sodium in the EBR-II secondary sodium system ({approx}50% of original inventory), were converted into NaHCO{sub 3}. No bare surfaces of residual sodium remained after treatment, and all remaining residual sodium deposits are covered by a layer of NaHCO{sub 3}. From a safety standpoint, the inventory of residual sodium in these systems was greatly reduced by using the carbonation process. From a regulatory standpoint, the process was not able to achieve deactivation of all residual sodium, and other more aggressive measures will be needed if the remaining residual sodium must also be deactivated to meet the requirements of the existing environmental permit. This chapter provides a project history and technical summary of the carbonation of EBR-II residual sodium. Options for future treatment are also discussed.« less

Sodium Polystyrene Sulfonate

MedlinePlus

Sodium polystyrene sulfonate is used to treat hyperkalemia (increased amounts of potassium in the body). Sodium polystyrene sulfonate is in a class of medications called potassium-removing agents. It works by ...

Development of cost-effective noncarbon sorbents for Hg(0) removal from coal-fired power plants.

PubMed

Lee, Joo-Youp; Ju, Yuhong; Keener, Tim C; Varma, Rajender S

2006-04-15

Noncarbonaceous materials or mineral oxides (silica gel, alumina, molecular sieves, zeolites, and montmorillonite) were modified with various functional groups such as amine, amide, thiol, urea, and active additives such as elemental sulfur, sodium sulfide, and sodium polysulfide to examine their potential as sorbents for the removal of elemental mercury (Hg(0)) vapor at coal-fired utility power plants. A number of sorbent candidates such as amine- silica gel, urea- silica gel, thiol- silica gel, amide-silica gel, sulfur-alumina, sulfur-molecular sieve, sulfur-montmorillonite, sodium sulfide-montmorillonite, and sodium polysulfide-montmorillonite, were synthesized and tested in a lab-scale fixed-bed system under an argon flow for screening purposes at 70 degrees C and/or 140 degrees C. Several functionalized silica materials reported in previous studies to effectively control heavy metals in the aqueous phase showed insignificant adsorption capacities for Hg(0) control in the gas phase, suggesting that mercury removal mechanisms in both phases are different. Among elemental sulfur-, sodium sulfide-, and sodium polysulfide-impregnated inorganic samples, sodium polysulfide-impregnated montmorillonite K 10 showed a moderate adsorption capacity at 70 degrees C, which can be used for sorbent injection prior to the wet FGD system.

Elucidation of the naproxen sodium adsorption onto activated carbon prepared from waste apricot: kinetic, equilibrium and thermodynamic characterization.

PubMed

Onal, Y; Akmil-Başar, C; Sarici-Ozdemir, C

2007-09-30

In this study, activated carbon (WA11Zn5) was prepared from waste apricot, which is waste in apricot plants in Malatya, by chemical activation with ZnCl(2). BET surface area of activated carbon is determined as 1060 m(2)/g. The ability of WA11Zn5, to remove naproxen sodium from effluent solutions by adsorption has been studied. Equilibrium isotherms for the adsorption of naproxen sodium on activated carbon were measured experimentally. Results were analyzed by the Langmiur, Freundlich equation using linearized correlation coefficient at 298 K. The characteristic parameters for each isotherm have been determined. Langmiur equation is found to best represent the equilibrium data for naproxen sodium-WA11Zn5 systems. The monolayer adsorption capacity of WA11Zn5 for naproxen sodium was found to be 106.38 mg/g at 298 K. The process was favorable and spontaneous. The kinetics of adsorption of naproxen sodium have been discussed using three kinetic models, i.e., the pseudo first-order model, the pseudo second-order model, the intraparticle diffusion model. Kinetic parameters and correlation coefficients were determined. It was shown that the pseudo second-order kinetic equation could describe the adsorption kinetics for naproxen sodium onto WA11Zn5. The thermodynamic parameters, such as DeltaG degrees , DeltaS degrees and DeltaH degrees, were calculated. The thermodynamics of naproxen sodium-WA11Zn5 system indicates endothermic process.

VOC removal and deodorization of effluent gases from an industrial plant by photo-oxidation, chemical oxidation, and ozonization.

PubMed

Domeño, Celia; Rodríguez-Lafuente, Angel; Martos, J M; Bilbao, Rafael; Nerín, Cristina

2010-04-01

The efficiency of photo-oxidation, chemical oxidation by sodium hypochlorite, and ozonization for the industrial-scale removal of volatile organic compounds (VOCs) and odors from gaseous emissions was studied by applying these treatments (in an experimental system) to substances passing through an emission stack of a factory producing maize derivatives. Absorption and ozonization were the most efficient treatment, removing 75% and 98% of VOCs, respectively, while photo-oxidation only removed about 59%. The emitted chemical compounds and odors were identified and quantified by gas chromatography-mass spectrometry (in full-scan mode). In addition to presenting the results, their implications for selecting optimal processes for treating volatile emissions are discussed.

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

Poirier, M.; Burket, P.

The Savannah River Site (SRS) is currently treating radioactive liquid waste with the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). Recently, the low filter flux through the ARP of approximately 5 gallons per minute has limited the rate at which radioactive liquid waste can be treated. Salt Batch 6 had a lower processing rate and required frequent filter cleaning. Savannah River Remediation (SRR) has a desire to understand the causes of the low filter flux and to increase ARP/MCU throughput. SRR requested SRNL to conduct bench-scale filter tests to evaluate whether sodium oxalate, sodiummore » aluminosilicate, or aluminum solids (i.e., gibbsite and boehmite) could be the cause of excessive fouling of the crossflow or secondary filter at ARP. The authors conducted the tests by preparing slurries containing 6.6 M sodium Salt Batch 6 supernate, 2.5 g MST/L slurry, and varying concentrations of sodium oxalate, sodium aluminosilicate, and aluminum solids, processing the slurry through a bench-scale filter unit that contains a crossflow primary filter and a dead-end secondary filter, and measuring filter flux and transmembrane pressure as a function of time. Among the conclusions drwn from this work are the following: (1) All of the tests showed some evidence of fouling the secondary filter. This fouling could be from fine particles passing through the crossflow filter. (2) The sodium oxalate-containing feeds behaved differently from the sodium aluminosilicate- and gibbsite/boehmite-containing feeds.« less

Improved Nitrogen Removal Effect In Continuous Flow A2/O Process Using Typical Extra Carbon Source

NASA Astrophysics Data System (ADS)

Wu, Haiyan; Gao, Junyan; Yang, Dianhai; Zhou, Qi; Cai, Bijing

2010-11-01

In order to provide a basis for optimal selection of carbon source, three typical external carbon sources (i.e. methanol, sodium acetate and leachate) were applied to examine nitrogen removal efficiency of continuous flow A2/O system with the influent from the effluent of grit chamber in the second Kunming wastewater treatment plant. The best dosage was determined, and the specific nitrogen removal rate and carbon consumption rate were calculated with regard to individual external carbon source in A2/O system. Economy and technology analysis was also conducted to select the suitable carbon source with a low operation cost. Experimental results showed that the external typical carbon source caused a remarkable enhancement of system nitrate degradation ability. In comparison with the blank test, the average TN and NH3-N removal efficiency of system with different dosing quantities of external carbon source was improved by 15.2% and 34.2%, respectively. The optimal dosage of methanol, sodium acetate and leachate was respectively up to 30 mg/L, 40 mg/L and 100 mg COD/L in terms of a high nitrogen degradation effect. The highest removal efficiency of COD, TN and NH3-N reached respectively 92.3%, 73.9% and 100% with methanol with a dosage of 30 mg/L. The kinetic analysis and calculation revealed that the greatest denitrification rate was 0.0107 mg TN/mg MLVSSṡd with sodium acetate of 60 mg/L. As to carbon consumption rate, however, the highest value occurred in the blank test with a rate of 0.1955 mg COD/mg MLVSSṡd. Also, further economic analysis proved leachate to be pragmatic external carbon source whose cost was far cheaper than methanol.

Technical Information on the Carbonation of the EBR-II Reactor, Summary Report Part 1: Laboratory Experiments and Application to EBR-II Secondary Sodium System

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

Steven R. Sherman

Residual sodium is defined as sodium metal that remains behind in pipes, vessels, and tanks after the bulk sodium metal has been melted and drained from such components. The residual sodium has the same chemical properties as bulk sodium, and differs from bulk sodium only in the thickness of the sodium deposit. Typically, sodium is considered residual when the thickness of the deposit is less than 5-6 cm. This residual sodium must be removed or deactivated when a pipe, vessel, system, or entire reactor is permanently taken out of service, in order to make the component or system safer and/ormore » to comply with decommissioning regulations. As an alternative to the established residual sodium deactivation techniques (steam-and-nitrogen, wet vapor nitrogen, etc.), a technique involving the use of moisture and carbon dioxide has been developed. With this technique, sodium metal is converted into sodium bicarbonate by reacting it with humid carbon dioxide. Hydrogen is emitted as a by-product. This technique was first developed in the laboratory by exposing sodium samples to humidified carbon dioxide under controlled conditions, and then demonstrated on a larger scale by treating residual sodium within the Experimental Breeder Reactor II (EBR-II) secondary cooling system, followed by the primary cooling system, respectively. The EBR-II facility is located at the Idaho National Laboratory (INL) in southeastern Idaho, U.S.A. This report is Part 1 of a two-part report. It is divided into three sections. The first section describes the chemistry of carbon dioxide-water-sodium reactions. The second section covers the laboratory experiments that were conducted in order to develop the residual sodium deactivation process. The third section discusses the application of the deactivation process to the treatment of residual sodium within the EBR-II secondary sodium cooling system. Part 2 of the report, under separate cover, describes the application of the technique to residual sodium treatment within the EBR-II primary sodium cooling system and related systems.« less

Removal of chloride from MSWI fly ash.

PubMed

Chen, Wei-Sheng; Chang, Fang-Chih; Shen, Yun-Hwei; Tsai, Min-Shing; Ko, Chun-Han

2012-10-30

The high levels of alkali chloride and soluble metal salts present in MSWI fly ash is worth noting for their impact on the environment. In addition, the recycling or reuse of fly ash has become an issue because of limited landfill space. The chloride content in fly ash limits its application as basis for construction materials. Water-soluble chlorides such as potassium chloride (KCl), sodium chloride (NaCl), and calcium chloride hydrate (CaCl(2) · 2H(2)O) in fly ash are easily washed away. However, calcium chloride hydroxide (Ca(OH)Cl) might not be easy to leach away at room temperature. The roasting and washing-flushing processes were applied to remove chloride content in this study. Additionally, air and CO(2) were introduced into the washing process to neutralize the hazardous nature of chlorides. In comparison with the water flushing process, the roasting process is more efficient in reducing the process of solid-liquid separation and drying for the reuse of Cl-removed fly ash particles. In several roasting experiments, the removal of chloride content from fly ash at 1050°C for 3h showed the best results (83% chloride removal efficiency). At a solid to liquid ratio of 1:10 the water-flushing process can almost totally remove water-soluble chloride (97% chloride removal efficiency). Analyses of mineralogical change also prove the efficiency of the fly ash roasting and washing mechanisms for chloride removal. Copyright © 2012 Elsevier B.V. All rights reserved.

Removal of cadmium (II) from simulated wastewater by ion flotation technique

PubMed Central

2013-01-01

A separation technique which has recently received a sharp increase in research activities is “ion flotation”. This technique has four important advantages for treating wastewaters: low energy consumption, small space requirements, small volume of sludge and acting selectively. The present study aims to optimize parameters of ion flotation for cadmium removal in simulated wastewater at laboratory scale. It was obtained on the reaction between Cd2+ and sodium dodecylesulfate (SDS) collector followed by flotation with ethanol as frother. Test solution was prepared by combining the required amount of cadmium ion, SDS and necessary frother or sodium sulfate solution. All experiments were carried out in a flotation column at laboratory temperature (27°C), adjusted pH = 4 and 120 minutes. The different parameters (namely: flow rate, cadmium, SDS and frother concentrations and ionic strength) influencing the flotation process were examined. The best removal efficiency obtained at a collector-metal ratio of 3:1 in 60 min with flow rate of 150 mL/min was 84%. The maximum cadmium removal was 92.1% where ethanol was introduced at a concentration 0.4% to flotation column with above conditions. The obtained results were promising, as both cadmium and collector were effectively removed from wastewater. Hence, the application of ion flotation for metal ions removal from effluents seems to be efficient. PMID:23388386

Method of purifying isosaccharinate

DOEpatents

Rai, Dhanpat; Moore, Robert C.; Tucker, Mark D.

2010-09-07

A method of purifying isosaccharinate by mixing sodium carbonate, potassium carbonate, sodium hydroxide or potassium hydroxide with calcium isosaccharinate, removing the precipitated calcium carbonate and adjusting the pH to between approximately 4.5 to 5.0 thereby removing excess carbonate and hydroxide to provide an acidic solution containing isosaccharinate.

Fractionation of Sodium Efflux in Frog Sartorius Muscles by Strophanthidin and Removal of External Sodium

PubMed Central

Horowicz, P.; Taylor, J. W.; Waggoner, D. M.

1970-01-01

The influence of strophanthidin, ouabain, and the removal of external sodium on the sodium efflux from frog sartorius muscle was measured. In freshly dissected muscles strophanthidin and ouabain in maximally effective concentrations reduced the efflux of sodium by about 50%. Of the sodium efflux which is strophanthidin-insensitive about 75% is inhibited after complete replacement of external sodium by lithium. In the absence of strophanthidin replacement of external sodium by lithium, calcium, or magnesium produces an initial rise in the sodium efflux, followed by a fall in the efflux as the exposure of the muscles to sodium-free media is continued. When the muscles are exposed for prolonged periods in sodium-free media, the fraction of internal sodium lost per minute is higher when returned to normal Ringer fluid than it was initially. The activation of sodium efflux by external sodium after long periods in sodium-free solutions is partly strophanthidin-sensitive and partly strophanthidin-insensitive. The internal sodium concentration is an important factor in these effects. The effects of temperature on the sodium efflux were also measured. Above 7°C the Q 10 of both the strophanthidin-sensitive and strophanthidin-insensitive sodium efflux is about 2.0. Below 7°C the strophanthidin-insensitive sodium efflux has a Q 10 of about 7.4. PMID:5315424

Inhibiting localized corrosion during storage of dilute SRP wastes

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

Oblath, S.B.; Congdon, J.W.

1986-01-01

High-level radioactive waste will be incorporated in borosilicate glass in the Defense Waste Processing Facility (DWPF) at the Savannah River Plant (SRP). As part of this process, large volumes of inorganic salt wastes will be decontaminated for disposal as low-level waste. The principal contaminants, /sup 137/Cs and /sup 90/Sr, are removed by treatment with sodium tetraphenylborate and sodium titanate. The resulting solids will be slurried with a dilute salt solution and stored in existing carbon steel tanks for several years prior to processing and disposal. Initial tests indicated a tendency for localized corrosion of the tanks. An investigation, using nonradioactivemore » simulants for the expected solution compositions, identified inhibitors which would protect the steel. Changes in solution compositions over time, due to radiolytic effects, were also accounted for by the simulants. Six inhibitors were identified which would protect the steel tanks. The effects these inhibitors would have on later processing steps in the DWPF were then evaluated. After this process, only sodium nitrite remained as an inhibitor that was both effective and compatible with the DWPF. The use of this inhibitor has been demonstrated on a real waste slurry.« less

An Improvement to Low-Level Radioactive Waste Vitrification Processes.

DTIC Science & Technology

1986-05-01

waste stream. 3 9 Sodium and Potassium tetraphenyl borates are both cited in the literature as having high cesium selectivity. 23󈧝󈧫 The thermal... Ferrate (II) Impregnated Zeolite for Cesium Removal from Radioactive Waste," Nuc. Tech., 58, p.242, ANS, La Grange Park, Illinois, (1982T. 29. F.V

Removal of six pesticide residues in cowpea with alkaline electrolysed water.

PubMed

Han, Yongtao; Song, Le; An, Quanshun; Pan, Canping

2017-06-01

Reduction of six pesticide residues (isoprocarb, chlorpyrifos, bifenthrin, beta-cypermethrin, difenoconazole and azoxystrobin) in cowpea by alkaline electrolysed water (AlEW) solutions with different pH was investigated. The commonly used washing treatments in household processing were used for comparison. The residue magnitudes were determined by gas chromatography coupled with tandem mass spectrometry (GC-MS/MS). Results showed that the removal effect of AlEW solution on the six pesticides was superior to tap water, 5% sodium chloride, 5% sodium carbonate and 5% acetic acid solution. AlEW with pH 12.2 had more potential to eliminate the six pesticides in cowpeas. Moreover, the reduction of pesticide residues gradually increased with the increase of washing time. This study demonstrated that AlEW solution with pH of 12.2 could be used to reduce pesticide residues on fresh cowpea samples. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Effect of Sodium Hydroxide Pretreatment of UOP IONSIV IE-911 Crystalline Silicotitanate Sorbent

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

Wilmarth, W.R.

2000-08-29

Use of crystalline silicotitanate (CST) to remove cesium represents one of the alternatives identified for High Level Waste pretreatment at the Savannah River Site (SRS). Previous deployment of CST in the Department of Energy complex subjected the material to mildly caustic environments. Processing of SRS waste will expose CST to very alkaline solutions for extended period of time (typically 12 months in the proposed design). Results of elevated temperature stability tests showed that silicon and one of the proprietary materials leached from the CST. UOP personnel indicated to SRS personnel that these materials exist in the sorbent in excess ofmore » required stoichiometry. The authors examined the pretreatment of CST with sodium hydroxide to remove these components prior to placing the CST in radioactive service. Additionally, researchers analyzed solids discovered in the feed line during a test by non-destructive techniques.« less

Effects of ammonium on uranium partitioning and kaolinite mineral dissolution.

PubMed

Emerson, Hilary P; Di Pietro, Silvina; Katsenovich, Yelena; Szecsody, Jim

2017-02-01

Ammonia gas injection is a promising technique for the remediation of uranium within the vadose zone. It can be used to manipulate the pH of a system and cause co-precipitation processes that are expected to remove uranium from the aqueous phase and decrease leaching from the solid phase. The work presented in this paper explores the effects of ammonium and sodium hydroxide on the partitioning of uranium and dissolution of the kaolinite mineral in simplified synthetic groundwaters using equilibrium batch sorption and sequential extraction experiments. It shows that there is a significant increase in uranium removal in systems with divalent cations present in the aqueous phase but not in sodium chloride synthetic groundwaters. Further, the initial conditions of the aqueous phase do not affect the dissolution of kaolinite. However, the type of base treatment does have an effect on mineral dissolution. Published by Elsevier Ltd.

Design and scale-up of an oxidative scrubbing process for the selective removal of hydrogen sulfide from biogas.

PubMed

Krischan, J; Makaruk, A; Harasek, M

2012-05-15

Reliable and selective removal of hydrogen sulfide (H(2)S) is an essential part of the biogas upgrading procedure in order to obtain a marketable and competitive natural gas substitute for flexible utilization. A promising biogas desulfurization technology has to ensure high separation efficiency regardless of process conditions or H(2)S load without the use or production of toxic or ecologically harmful substances. Alkaline oxidative scrubbing is an interesting alternative to existing desulfurization technologies and is investigated in this work. In experiments on a stirred tank reactor and a continuous scrubbing column in laboratory-scale, H(2)S was absorbed from a gas stream containing large amounts of carbon dioxide (CO(2)) into an aqueous solution prepared from sodium hydroxide (NaOH), sodium bicarbonate (NaHCO(3)) and hydrogen peroxide (H(2)O(2)). The influence of pH, redox potential and solution aging on the absorption efficiency and the consumption of chemicals was investigated. Because of the irreversible oxidation reactions of dissolved H(2)S with H(2)O(2), high H(2)S removal efficiencies were achieved while the CO(2) absorption was kept low. At an existing biogas upgrading plant an industrial-scale pilot scrubber was constructed, which efficiently desulfurizes 180m(3)/h of raw biogas with an average removal efficiency of 97%, even at relatively high and strongly fluctuating H(2)S contents in the crude gas. Copyright © 2012 Elsevier B.V. All rights reserved.

Impurities Removal in Seawater to Optimize the Magnesium Extraction

NASA Astrophysics Data System (ADS)

Natasha, N. C.; Firdiyono, F.; Sulistiyono, E.

2017-02-01

Magnesium extraction from seawater is promising way because magnesium is the second abundant element in seawater and Indonesia has the second longest coastline in the world. To optimize the magnesium extraction, the impurities in seawater need to be eliminated. Evaporation and dissolving process were used in this research to remove the impurities especially calcium in seawater. Seawater which has been evaporated from 100 ml to 50 ml was dissolved with variations solution such as oxalic acid and ammonium bicarbonate. The solution concentration is 100 g/l and it variations are 2 ml, 4 ml, 6 ml, 8 ml, 10 ml, 20 ml, 30 ml, 40 ml and 50 ml. This step will produce precipitate and filtrate then it will be analysed to find out the result of this process. The precipitate was analysed by X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) but the filtrate was analysed by Inductively Coupled Plasma (ICP). XRD analysis shows that calcium oxalate and calcium carbonate were formed and ICP analysis shows that the remaining calcium in seawater using oxalic acid is about 0.01% and sodium 0.14% but when using ammonium bicarbonate the remaining calcium is 2.5% and sodium still more than 90%. The results show that both oxalic acid and ammonium bicarbonate can remove the impurities but when using oxalic acid, not only the impurities but also magnesium was precipitated. The conclusion of this research is the best solution to remove the impurities in seawater without precipitate the magnesium is using ammonium bicarbonate.

Recovery process for electroless plating baths

DOEpatents

Anderson, Roger W.; Neff, Wayne A.

1992-01-01

A process for removing, from spent electroless metal plating bath solutions, accumulated byproducts and counter-ions that have deleterious effects on plating. The solution, or a portion thereof, is passed through a selected cation exchange resin bed in hydrogen form, the resin selected from strong acid cation exchangers and combinations of intermediate acid cation exchangers with strong acid cation exchangers. Sodium and nickel ions are sorbed in the selected cation exchanger, with little removal of other constituents. The remaining solution is subjected to sulfate removal through precipitation of calcium sulfate hemihydrate using, sequentially, CaO and then CaCO.sub.3. Phosphite removal from the solution is accomplished by the addition of MgO to form magnesium phosphite trihydrate. The washed precipitates of these steps can be safely discarded in nontoxic land fills, or used in various chemical industries. Finally, any remaining solution can be concentrated, adjusted for pH, and be ready for reuse. The plating metal can be removed from the exchanger with sulfuric acid or with the filtrate from the magnesium phosphite precipitation forming a sulfate of the plating metal for reuse. The process is illustrated as applied to processing electroless nickel plating baths.

Recovery process for electroless plating baths

DOEpatents

Anderson, R.W.; Neff, W.A.

1992-05-12

A process is described for removing, from spent electroless metal plating bath solutions, accumulated byproducts and counter-ions that have deleterious effects on plating. The solution, or a portion thereof, is passed through a selected cation exchange resin bed in hydrogen form, the resin selected from strong acid cation exchangers and combinations of intermediate acid cation exchangers with strong acid cation exchangers. Sodium and nickel ions are sorbed in the selected cation exchanger, with little removal of other constituents. The remaining solution is subjected to sulfate removal through precipitation of calcium sulfate hemihydrate using, sequentially, CaO and then CaCO[sub 3]. Phosphite removal from the solution is accomplished by the addition of MgO to form magnesium phosphite trihydrate. The washed precipitates of these steps can be safely discarded in nontoxic land fills, or used in various chemical industries. Finally, any remaining solution can be concentrated, adjusted for pH, and be ready for reuse. The plating metal can be removed from the exchanger with sulfuric acid or with the filtrate from the magnesium phosphite precipitation forming a sulfate of the plating metal for reuse. The process is illustrated as applied to processing electroless nickel plating baths. 18 figs.

Thermal desorption of PCB-contaminated soil with sodium hydroxide.

PubMed

Liu, Jie; Qi, Zhifu; Zhao, Zhonghua; Li, Xiaodong; Buekens, Alfons; Yan, Jianhua; Ni, Mingjiang

2015-12-01

The thermal desorption was combined with sodium hydroxide to remediate polychlorinated biphenyl (PCB)-contaminated soil. The experiments were conducted at different temperatures ranging from 300 to 600 °C with three NaOH contents of 0.1, 0.5, and 1 %. The results showed that thermal desorption was effective for PCB removal, destruction, and detoxication, and the presence of NaOH enhanced the process by significant dechlorination. After treatment with 0.1 % NaOH, the removal efficiency (RE) increased from 84.8 % at 300 °C to 98.0 % at 600 °C, corresponding to 72.7 and 91.7 % of destruction efficiency (DE). With 1 % NaOH content treated at 600 °C, the RE and DE were 99.0 and 93.6 %, respectively. The effect of NaOH content on PCB removal was significant, especially at lower temperature, yet it weakened under higher temperature. The interaction between NaOH content and temperature influenced the PCB composition. The higher temperature with the help of NaOH effectively increased the RE and DE of 12 dioxin-like PCBs (based on WHO-TEQ).

A Review Over Benefits and Drawbacks of Combining Sodium Hypochlorite with Other Endodontic Materials.

PubMed

Mohammadi, Zahed; Shalavi, Sousan; Moeintaghavi, Amir; Jafarzadeh, Hamid

2017-01-01

As the root canal system considered to be complex and unpredictable, using root canal irrigants and medicaments are essential in order to enhance the disinfection of the canal. Sodium hypochlorite is the most common irrigant in endodontics. Despite its excellent antimicrobial activity and tissue solubility, sodium hypochlorite lacks some important properties such as substantivity and smear layer removing ability. The aim of this review was to address benefits and drawbacks of combining sodium hypochlorite with other root canal irrigants and medicaments. According to the reviewed articles, NaOCl is the most common irrigation solution in endodontics. However, it has some drawbacks such as inability to remove smear layer. One of the drawbacks of NaOCl is its inability to remove the smear layer and lack of substantivity. The adjunctive use of other materials has been suggested to improve NaOCl efficacy. Nevertheless, further studies are required in this field.

Removal of plutonium and americium from alkaline waste solutions

DOEpatents

Schulz, Wallace W.

1979-01-01

High salt content, alkaline waste solutions containing plutonium and americium are contacted with a sodium titanate compound to effect removal of the plutonium and americium from the alkaline waste solution onto the sodium titanate and provide an effluent having a radiation level of less than 10 nCi per gram alpha emitters.

Bi2WO6 nanoflowers: An efficient visible light photocatalytic activity for ceftriaxone sodium degradation

NASA Astrophysics Data System (ADS)

Zhao, Yanyan; Wang, Yongbo; Liu, Enzhou; Fan, Jun; Hu, Xiaoyun

2018-04-01

The morphology-controlled synthesis of nano-structure photocatalyst have leaded a new possibility to improve their physical and chemical properties. Herein, Bi2WO6 nanocrystals (BWO) with nano-flower, nano plates, knot shape, rod like and irregular morphologies have been successfully synthesized through a highly facile hydrothermal process by simply adjusting pH values, reactive solvents and temperature. Photocatalytic activity of the as-prepared samples were evaluated by degradation of Ceftriaxone sodium under visible light irradiation (λ > 420 nm), the results indicated that all the BWO samples exhibit morphology-associated photocatalytic activity, and the 3D flowerlike-structure of BWO composed of well-ordered nano plates (BWO-D-5) displayed the outstanding photocatalytic activity. Through getting insight into the mechanism, h+ and rad O2- play major roles compared with rad OH in photocatalytic degradation process. The possible pathway of Ceftriaxone sodium and the intermediates were proposed to better understand the reaction process. Moreover, this work not only provides an example of morphology-dependent photocatalytic activity of BWO but also provides an illustrative example for removing organic pollutant molecules according to practical requirements.

Isolation of nonvolatile, organic solutes from natural waters by zeotrophic distillation of water from N,N-dimethylformamide

USGS Publications Warehouse

Leenheer, J.A.; Brown, P.A.; Stiles, E.A.

1987-01-01

Nonvolatile, organic solutes that comprise the dissolved organic carbon (DOC) in saline waters were isolated by removal of the water by distillation from a N,N-dimethylformamideformic acid-acetonitrile mixture. Salts isolated with the DOC were removed by crystallization of sodium chloride and sodium sulfate from the solvent mixture, removal of silicic acid by acidification and precipitation, removal of boric acid by methylation and volatilization, and removal of phosphate by zinc acetate precipitation. Chemical alteration of the organic solutes was minimized during evaporative concentration steps by careful control of acid concentrations in the solvent mixture and was minimized during drying by conversion of the samples to pyridinium and sodium salts. Recoveries of various hydrophilic organic standards from aqueous salt solutions and recoveries of natural organic solutes from various water samples varied from 60 to 100%. Losses of organic solutes during the isolation procedure were nonselective and related to the number of salt- and precipitate-washing cycles in the procedure.

Desalination of fish sauce by electrodialysis: effect on selected aroma compounds and amino acid compositions.

PubMed

Chindapan, Nathamol; Devahastin, Sakamon; Chiewchan, Naphaporn; Sablani, Shyam S

2011-09-01

Fish sauce is an ingredient that exhibits unique flavor and is widely used by people in Southeast Asia. Fish sauce, however, contains a significant amount of salt (sodium chloride). Recently, electrodialysis (ED) has been successfully applied to reduce salt in fish sauce; however, no information is available on the effect of ED on changes in compounds providing aroma and taste of ED-treated fish sauce. The selected aroma compounds, amino acids, and sensory quality of the ED-treated fish sauce with various salt concentrations were then analyzed. The amounts of trimethylamine, 2,6-dimethylpyrazine, phenols, and all carboxylic acids except for hexanoic acid significantly decreased, whereas benzaldehyde increased significantly when the salt removal level was higher. The amounts of all amino acids decreased with the increased salt removal level. Significant difference in flavor and saltiness intensity among ED-treated fish sauce with various salt concentrations, as assessed by a discriminative test, were observed. Information obtained in this work can serve as a guideline for optimization of a process to produce low-sodium fish sauce by ED. It also forms a basis for further in-depth sensory analysis of low-sodium fish sauce. © 2011 Institute of Food Technologists®

Comparison of magnesium sulfate and sodium sulfate for removal of water from pesticide extracts of foods.

PubMed

Schenck, Frank J; Callery, Patrick; Gannett, Peter M; Daft, Jonathan R; Lehotay, Steven J

2002-01-01

Water-miscible solvents, such as acetone and acetonitrile, effectively extract both polar and nonpolar pesticide residues from nonfatty foods. The addition of sodium chloride to the resulting acetonitrile-water or acetone-water extract (salting out) results in the separation of the water from the organic solvent. However, the organic solvent layer (pesticide extract) still contains some residual water, which can adversely affect separation procedures that follow, such as solid-phase extraction and/or gas chromatography. Drying agents, such as sodium sulfate or magnesium sulfate, are used to remove the water from the organic extracts. In the present study, we used nuclear magnetic resonance spectroscopy to study the composition of the phases resulting from salting out and to compare the effectiveness of sodium sulfate and magnesium sulfate as drying agents. The study showed that considerable amounts of water remained in the organic phase after phase separation. Sodium sulfate was a relatively ineffective drying agent, removing little or no residual water from the organic solvent. Magnesium sulfate proved to be a much more effective drying agent.

Performance of combined sodium persulfate/H2O2 based advanced oxidation process in stabilized landfill leachate treatment.

PubMed

Hilles, Ahmed H; Abu Amr, Salem S; Hussein, Rim A; El-Sebaie, Olfat D; Arafa, Anwaar I

2016-01-15

A combination of persulfate and hydrogen peroxide (S2O8(2-)/H2O2) was used to oxidizelandfill leachate. The reaction was performed under varying S2O8(2-)/H2O2 ratio (g/g), S2O8(2-)/H2O2 dosages (g/g), pH, and reaction time (minutes), so as to determine the optimum operational conditions. Results indicated that under optimum operational conditions (i.e. 120 min of oxidation using a S2O8(2-)/H2O2 ratio of 1 g/1.47 g at a persulfate and hydrogen peroxide dosage of 5.88 g/50 ml and8.63 g/50 ml respectively, at pH 11) removal of 81% COD and 83% NH3-N was achieved. In addition, the biodegradability (BOD5/COD ratio) of the leachate was improved from 0.09 to 0.17. The results obtained from the combined use of (S2O8(2-)/H2O2) were compared with those obtained with sodium persulfate only, hydrogen peroxide only and sodium persulfate followed by hydrogen peroxide. The combined method (S2O8(2-)/H2O2) achieved higher removal efficiencies for COD and NH3-N compared with the other methods using a single oxidizing agent. Additionally, the study has proved that the combination of S2O8(2-)/H2O2 is more efficient than the sequential use of sodium persulfate followed by hydrogen peroxide in advanced oxidation processes aiming at treatingstabilizedlandfill leachate. Copyright © 2015 Elsevier Ltd. All rights reserved.

Removal of insoluble heavy metal sulfides from water.

PubMed

Banfalvi, Gaspar

2006-05-01

The necessity of heavy metal removal from wastewater has led to increasing interest in absorbents. We have developed a new approach to obtain high metal adsorption capacity by precipitating metal sulfides with sodium sulfide on the surface of bentonite and adhere them to the absorbent. This method allowed to remove approximately 90% of cadmium as CdS from 10(-4)-10(-6) M CdCl2 solutions. Additional reactions are related to the removal of excess sodium sulfide by the release of hydrogen sulfide and oxidation to sulfur using carbogen gas (5% CO2, 95% O2) followed by aeration.

Effects of water vapor pretreatment time and reaction temperature on CO(2) capture characteristics of a sodium-based solid sorbent in a bubbling fluidized-bed reactor.

PubMed

Seo, Yongwon; Jo, Sung-Ho; Ryu, Chong Kul; Yi, Chang-Keun

2007-10-01

CO(2) capture from flue gas using a sodium-based solid sorbent was investigated in a bubbling fluidized-bed reactor. Carbonation and regeneration temperature on CO(2) removal was determined. The extent of the chemical reactivity after carbonation or regeneration was characterized via (13)C NMR. In addition, the physical properties of the sorbent such as pore size, pore volume, and surface area after carbonation or regeneration were measured by gas adsorption method (BET). With water vapor pretreatment, near complete CO(2) removal was initially achieved and maintained for about 1-2min at 50 degrees C with 2s gas residence time, while without proper water vapor pretreatment CO(2) removal abruptly decreased from the beginning. Carbonation was effective at the lower temperature over the 50-70 degrees C temperature range, while regeneration more effective at the higher temperature over the 135-300 degrees C temperature range. To maintain the initial 90% CO(2) removal, it would be necessary to keep the regeneration temperature higher than about 135 degrees C. The results obtained in this study can be used as basic data for designing and operating a large scale CO(2) capture process with two fluidized-bed reactors.

Removal of chromium (VI) from aqueous solution using walnut hull.

PubMed

Wang, Xue Song; Li, Zhi Zhong; Tao, Sheng Rong

2009-02-01

In this study, removal of chromium (VI) from aqueous solution by walnut hull (a local low-cost adsorbent) was studied. The extent of adsorption was investigated as a function of solution pH, contact time, adsorbent and adsorbate concentration, reaction temperature and supporting electrolyte (sodium chloride). The Cr (VI) removal was pH-dependent, reaching a maximum (97.3%) at pH 1.0. The kinetic experimental data were fitted to the first-order, modified Freundlich, intraparticle diffusion and Elovich models and the corresponding parameters were obtained. A 102.78 kJ/mol Ea (activation energy) for the reaction of chromium (VI) adsorption onto walnut indicated that the rate-limiting step in this case might be a chemically controlled process. Both the Langmuir and Freundlich isotherms were suitable for describing the biosorption of chromium (VI) onto walnut hull. The uptake of chromium (VI) per weight of adsorbent increased with increasing initial chromium (VI) concentration up to 240-480 mg/L, and decreased sharply with increasing adsorbent concentration ranging from 1.0 to 5.0 g/L. An increase in sodium chloride (as supporting electrolyte) concentration was found to induce a negative effect while an increase in temperature was found to give rise to a positive effect on the chromium (VI) adsorption process. Compared to the various other adsorbents reported in the literature, the walnut hull in this study shows very good promise for practical applicability.

Filter vapor trap

DOEpatents

Guon, Jerold

1976-04-13

A sintered filter trap is adapted for insertion in a gas stream of sodium vapor to condense and deposit sodium thereon. The filter is heated and operated above the melting temperature of sodium, resulting in a more efficient means to remove sodium particulates from the effluent inert gas emanating from the surface of a liquid sodium pool. Preferably the filter leaves are precoated with a natrophobic coating such as tetracosane.

Electrochemical Dissolution of Tungsten Carbide in NaCl-KCl-Na2WO4 Molten Salt

NASA Astrophysics Data System (ADS)

Zhang, Liwen; Nie, Zuoren; Xi, Xiaoli; Ma, Liwen; Xiao, Xiangjun; Li, Ming

2018-02-01

Tungsten carbide was utilized as anode to extract tungsten in a NaCl-KCl-Na2WO4 molten salt, and the electrochemical dissolution was investigated. Although the molten salt electrochemical method is a short process method of tungsten extraction from tungsten carbide in one step, the dissolution efficiency and current efficiency are quite low. In order to improve the dissolution rate and current efficiency, the sodium tungstate was added as the active substance. The dissolution rate, the anode current efficiency, and the cathode current efficiency were calculated with different contents of sodium tungstate addition. The anodes prior to and following the reaction, as well as the product, were analyzed through X-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry. The results demonstrated that the sodium tungstate could improve the dissolution rate and the current efficiency, due to the addition of sodium tungstate decreasing the charge transfer resistance in the electrolysis system. Due to the fact that the addition of sodium tungstate could remove the carbon during electrolysis, pure tungsten powders with 100 nm diameter were obtained when the content of sodium tungstate was 1.0 pct.

TREATMENT FOR IMPROVING THE OPERATION OF STRONG BASE ANION EXCHANGE RESINS

DOEpatents

Stevenson, P.C.

1960-11-29

A process is offered for improving quaternary ammonium type strongly basic anion exchange resins so that centain zinc and cadmium residues, which normally stick to and "poison" this type of resin, can be removed by elution. Specifically, the resin as obtained commercially is treated with an aqueous solution of sodium hydroxide of about 1 to 4 M concentration by heating therein and periodically adding small amounts of oxidizing agent selected from hydrogen peroxide, sodium peroxide and hypochlorite. Zinc and cadmium values may then be adsorbed onto the resin from a 0.1 to 3 M HCl and thereafter eluted therefrom with very dilute HCl solutions.

Managing Hyperkalemia: Stepping Into a New Frontier.

PubMed

Pham, Antony Q; Sexton, Jessica; Wimer, Dexter; Rana, Isha; Nguyen, Timothy

2017-10-01

Maintaining potassium balance in the body is essential for cellular function. Even a slight increase in normal serum potassium levels (3.5-5.0 mEq/L) can interfere with metabolism, electrical action potentials, and cellular processes. Hyperkalemia is commonly seen in patients with chronic kidney disease (CKD) and in patients on renin-angiotensin-aldosterone system (RAAS) inhibitors. Sodium polystyrene sulfonate (SPS), diuretics, and hemodialysis are currently available methods for removing potassium from the body; however, these options have their limitations. Patiromer (Veltassa) and sodium zirconium cyclosilicate are 2 new therapeutic options that can potentially lead a new frontier in the management of hyperkalemia. This article will review these novel treatments.

Organic contaminant removal efficiency of sodium bentonite/clay (BC) mixtures in high permeability regions utilizing reclaimed wastewater: A meso-scale study

NASA Astrophysics Data System (ADS)

Xiao, Yang; Li, Yunkai; Ning, Zigong; Li, Pengxiang; Yang, Peiling; Liu, Chengcheng; Liu, Zhongwei; Xu, Feipeng; Hynds, Paul Dylan

2018-03-01

Wastewater reclamation now represents an effective measure for sustainable water resource management in arid regions, however wastewater components (organic micropollutants) may potentially impact local ecological and/or human health. Previous studies have shown that sodium bentonite/natural clay (BC) mixes may be used to effectively reduce riverbed infiltration in regions characterized by excessively high hydraulic conductivity. Accordingly, the current study sought to investigate the contaminant removal efficiency (Re) of several BC mass ratios in simulated dry riverbeds. Results indicate that the measured Re of NH4+-N, CODcr and BOD5 increased in concurrence with an increasing sodium bentonite ratio, up to a maximum Re of 97.4% (NH4+-N), 55.2% (CODcr), and 51.5% (BOD5). The primary contaminant removal site was shown to be the infiltration-reducing (BC) layer, accounting for approximately 40%, 60%, and 70% of NH4+-N, CODcr and BOD5 removal, respectively. Conversely, the removal efficiency of NO3-N was found to be low (<15%), while total phosphorous (TP) was found to actively leach from the infiltration-reduction layer, resulting in measured TP discharges 2.4-4.8 times those of initial infiltration values. The current study provides a technical baseline for the efficacy of sodium bentonite as an effective bi-functional material in areas utilizing reclaimed water i.e. concurrent reduction of infiltration rates (Function 1) and decontamination of reclaimed wastewater infiltration/recharge (Function 2). Findings indicate that sodium bentonite-clay mixes may represent a feasible alternative for managing recharge of non-potable aquifers with reclaimed wastewater.

Polyurethane foam loaded with sodium dodecylsulfate for the extraction of 'quat' pesticides from aqueous medium: Optimization of loading conditions.

PubMed

Vinhal, Jonas O; Lima, Claudio F; Cassella, Ricardo J

2016-09-01

The cationic herbicides paraquat, diquat and difenzoquat are largely used in different cultures worldwide. With this, there is an intrinsic risk of environmental contamination when these herbicides achieve natural waters. The goal of this work was to propose a novel and low-cost sorbent for the removal of the cited herbicides from aqueous medium. The proposed sorbent was prepared by loading polyurethane foam with sodium dodecylsulfate. The influence of several parameters (SDS concentration, HCl concentration and shaking time) on the loading process was investigated. The results obtained in this work demonstrated that all studied variables influenced the loading process, having significant effect on the extraction efficiency of the resulted PUF-SDS. At optimized conditions, the PUF was loaded by shaking 200mg of crushed foam with 200mL of a solution containing 5.0×10(-3)molL(-1) SDS and 0.25molL(-1) HCl, for 30min. The obtained PUF-SDS was efficient for removing the three herbicides from aqueous medium, achieving extraction percentages higher than 90%. The sorption process followed a pseudo second-order kinetics, which presented excellent predictive capacity of the amount of herbicide retained with time. Copyright © 2016 Elsevier Inc. All rights reserved.

Cyanide and Copper Recovery from Barren Solution of the Merrill Crowe Process

NASA Astrophysics Data System (ADS)

Parga, José R.; Valenzuela, Jesús L.; Díaz, J. A.

This paper is a brief overview of the role of inducing the nucleated precipitation of copper and cyanide in a flashtube serpentine reactor, using sodium sulfide as the precipitate and sulfuric acid as pH control. The results showed that pH had a great effect on copper cyanide removal efficiency and the optimum pH was about 3 to 3.5. At this pH value copper cyanide removal efficiency could be achieved above 97 and 99 %, when influent copper concentration ions were 650 and 900 ppm respectively. In this process the cyanide associated with the copper, zinc, iron cyanide complexes are released as HCN gas under strong acidic conditions, allowing it to be recycled back to the cyanidation process as free cyanide.

Cold Trap Dismantling and Sodium Removal at a Fast Breeder Reactor - 12327

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

Graf, A.; Petrick, H.; Stutz, U.

2012-07-01

The first German prototype Fast Breeder Nuclear Reactor (KNK) is currently being dismantled after being the only operating Fast Breeder-type reactor in Germany. As this reactor type used sodium as a coolant in its primary and secondary circuit, seven cold traps containing various amounts of partially activated sodium needed to be disposed of as part of the dismantling. The resulting combined difficulties of radioactive contamination and high chemical reactivity were handled by treating the cold traps differently depending on their size and the amount of sodium contained inside. Six small cold traps were processed onsite by cutting them up intomore » small parts using a band saw under a protective atmosphere. The sodium was then converted to sodium hydroxide by using water. The remaining large cold trap could not be handled in the same way due to its dimensions (2.9 m x 1.1 m) and the declared amount of sodium inside (1,700 kg). It was therefore manually dismantled inside a large box filled with a protective atmosphere, while the resulting pieces were packaged for later burning in a special facility. The experiences gained by KNK during this process may be advantageous for future dismantling projects in similar sodium-cooled reactors worldwide. The dismantling of a prototype fast breeder reactor provides the challenge not only to dismantle radioactive materials but also to handle sodium-contaminated or sodium-containing components. The treatment of sodium requires additional equipment and installations to ensure a safe handling. Since it is not permitted to bring sodium into a repository, all sodium has to be neutralized either through a controlled reaction with water or by incinerating. The resulting components can be disposed of as normal radioactive waste with no further conditions. The handling of sodium needs skilled and experienced workers to minimize the inherent risks. And the example of the disposal of the large KNK cold trap shows the interaction with others and also foreign decommissioning projects can provide solutions with were unknown before. (authors)« less

Evaluation of ethylenediaminetetraacetic acid (EDTA) solution and gel for smear layer removal.

PubMed

Dotto, Sidney Ricardo; Travassos, Rosana Maria Coelho; de Oliveira, Elias Pandonor Motcy; Machado, Manoel Eduardo de Lima; Martins, José Luiz

2007-08-01

The purpose of this in vitro study was to compare the efficacy of 24% ethylenediaminetetraacetic acid (EDTA) gel and 17% EDTA solution in cleaning dentine walls after root canal instrumentation. Thirty human canine teeth were divided into three groups of 10 teeth each. In Group 1, 1% sodium hypochlorite was used as the irrigating solution; in Group 2, 1% sodium hypochlorite was used with 17% EDTA solution; and in Group 3, 1% sodium hypochlorite was used with 24% EDTA gel. The presence of a smear layer was analysed after instrumentation using scanning electron microscopy. The Kruskal-Wallis test revealed a statistical difference (P < 0.05) between Groups 1 and 2, and also between Groups 1 and 3. No difference was observed between Groups 2 and 3 (P > 0.05). The results indicate that 1% sodium hypochlorite alone does not remove the smear layer and that there was no statistical difference between EDTA gel and EDTA solution in smear layer removal.

A Review Over Benefits and Drawbacks of Combining Sodium Hypochlorite with Other Endodontic Materials

PubMed Central

Mohammadi, Zahed; Shalavi, Sousan; Moeintaghavi, Amir

2017-01-01

Introduction: As the root canal system considered to be complex and unpredictable, using root canal irrigants and medicaments are essential in order to enhance the disinfection of the canal. Sodium hypochlorite is the most common irrigant in endodontics. Despite its excellent antimicrobial activity and tissue solubility, sodium hypochlorite lacks some important properties such as substantivity and smear layer removing ability. Objective: The aim of this review was to address benefits and drawbacks of combining sodium hypochlorite with other root canal irrigants and medicaments. Discussion: According to the reviewed articles, NaOCl is the most common irrigation solution in endodontics. However, it has some drawbacks such as inability to remove smear layer. One of the drawbacks of NaOCl is its inability to remove the smear layer and lack of substantivity. Conclusion: The adjunctive use of other materials has been suggested to improve NaOCl efficacy. Nevertheless, further studies are required in this field. PMID:29387282

Enhancing total nitrogen removal from wastewater of a science and industrial park using entrapped biomass.

PubMed

Chao, Yeong-Nan; Ng, Kok-Kwang; Wu, Chung-Hsin; Hong, Pui-Kwan Andy; Lin, Cheng-Fang

2014-01-01

This study employed entrapped biomass technology to augment the conventional activated sludge process with anoxic-oxic (AO)/anaerobic-anoxic-oxic (A20) functions for the removal of total nitrogen (TN) from wastewater of a science and industrial park in Taiwan. The entrapped biomass unit was fabricated in the format of carrier plates on which microbial cells were entrapped. Due to mass transport limitations, anoxic and anaerobic conditions were created within the bioplates that enabled denitrification to occur. The treatment basin incorporated an equivalent amount of 1300-2400mg MLSS/L of activated sludge on the bioplates at packing ratios of 10-30% (volume ratio ofbioplates to basin) operating with the addition of sodium carbonate for alkalinity and methanol for the electron donor. The results showed nearly 90% of ammonia nitrogen being converted to nitrate and 63% of TN removal, in comparison with typically 10% of TN removal in traditional activated sludge process of domestic wastewater plants.

Demonstration of the efficiency and robustness of an acid leaching process to remove metals from various CCA-treated wood samples.

PubMed

Coudert, Lucie; Blais, Jean-François; Mercier, Guy; Cooper, Paul; Janin, Amélie; Gastonguay, Louis

2014-01-01

In recent years, an efficient and economically attractive leaching process has been developed to remove metals from copper-based treated wood wastes. This study explored the applicability of this leaching process using chromated copper arsenate (CCA) treated wood samples with different initial metal loading and elapsed time between wood preservation treatment and remediation. The sulfuric acid leaching process resulted in the solubilization of more than 87% of the As, 70% of the Cr, and 76% of the Cu from CCA-chips and in the solubilization of more than 96% of the As, 78% of the Cr and 91% of the Cu from CCA-sawdust. The results showed that the performance of this leaching process might be influenced by the initial metal loading of the treated wood wastes and the elapsed time between preservation treatment and remediation. The effluents generated during the leaching steps were treated by precipitation-coagulation to satisfy the regulations for effluent discharge in municipal sewers. Precipitation using ferric chloride and sodium hydroxide was highly efficient, removing more than 99% of the As, Cr, and Cu. It appears that this leaching process can be successfully applied to remove metals from different CCA-treated wood samples and then from the effluents. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ion-Selective Deposition of Manganese Sulphate Solution from Trenggalek Manganese Ore by Active Carbon and Sodium Hydroxide

NASA Astrophysics Data System (ADS)

Andriyah, L.; Sulistiyono, E.

2017-02-01

One of the step in manganese dioxide manufacturing process for battery industry is a purification process of lithium manganese sulphate solution. The elimination of impurities such as iron removal is important in hydrometallurgical processes. Therefore, this paper present the purification results of manganese sulphate solution by removing impurities using a selective deposition method, namely activated carbon adsorption and NaOH. The experimental results showed that the optimum condition of adsorption process occurs on the addition of 5 g adsorbent and the addition of 10 ml NaOH 1 N, processing time of 30 minutes and the best is the activated carbon adsorption of Japan. Because the absolute requirement of the cathode material of lithium ion manganese are free of titanium then of local wood charcoal is good enough in terms of eliminating ions Ti is equal to 70.88%.

Evaluation of continuous oxydesulfurization processes. Final technical report, September 1979-July 1981

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

Jones, J.F.; Wever, D.M.

1981-07-01

Three processes developed by Pittsburgh Energy Technology Center (PETC), Ledgemont Laboratories, and Ames Laboratories for the oxydesulfurization of coal were evaluated in continuous processing equipment designed, built, and/or adapted for the purpose at the DOE-owned Multi-Use Fuels and Energy Processes Test Plant (MEP) located at TRW's Capistrano Test Site in California. The three processes differed primarily in the chemical additives (none, sodium carbonate, or ammonia), fed to the 20% to 40% coal/water slurries, and in the oxygen content of the feed gas stream. Temperature, pressure, residence time, flow rates, slurry concentration and stirrer speed were the other primary independent variables.more » The amount of organic sulfur removed, total sulfur removed and the Btu recovery were the primary dependent variables. Evaluation of the data presented was not part of the test effort.« less

Method for mobilization of hazardous metal ions in soils

DOEpatents

Dugan, Patrick R.; Pfister, Robert M.

1995-01-01

A microbial process for removing heavy metals such as bismuth, cadmium, lead, thorium, uranium and other transuranics from soils and sediments, utilizing indigenous, or isolates of indigenous, microorganisms and reducing agents, such as cysteine or sodium thioglycollate, or complexing agents such as the amino acid glycine, to effect the mobilization or release of the metals from the soil particles.

Alternaria and Cladosporium Fungal Allergen Epitopes are Denatured by Sodium Hypochlorite

PubMed Central

2009-01-01

Background Fungal allergens are ubiquitous; however, little progress has been made understanding fungal allergenic material removal from indoor environments. Purpose We investigated removal of environmental allergenic material derived from Alternaria and Cladosporium using sodium hypochlorite in vivo and in vitro. Methods Freeze dried allergen extract from Alternaria alternata and Cladosporium herbarum was treated with hypochlorite concentrations of 322, 88, 38, 16, 3, 0.3, and 0 mM, respectively. Remaining native allergenic material was quantified using enzyme immunoassay and remaining viable fungal material was evaluated. Results The results of treating Alternaria or Cladosporium extract with sodium hypochlorite are immediate and obvious. Concentrations greater than 100 mM remove color and concentrations between 100 and 38 mM partially uncolored the extract. Immunoassay for total antigenic and allergenic material remaining after treatment with sodium hypochlorite including 2 concentrations recommended for killing fungus confirmed a general destruction of antigenic and allergenic material at concentrations of 38 mM or greater. Conclusions This work confirms the ability of solutions of sodium hypochlorite to denature fungal allergenic material from common outdoor and indoor fungi A. alternata and C. herbarum. Destruction of recognized antigenic and allergenic epitopes occurs at hypochlorite concentrations commonly used for household cleaning. PMID:23282316

Removal of cadmium from contaminated Lentinula edodes by optimized complexation and coagulation.

PubMed

Wang, Yi; Wang, Chen; Cheng, Wei; Bian, Yinbing; Guo, Peng

2017-03-01

Heavy metal pollution is a serious problem for Lentinula edodes ; however, the treatment of contaminated L. edodes has seldom been studied. This study investigated the removal of cadmium (Cd) from contaminated L. edodes and its lentinan by complexation and coagulation. Some influencing factors, such as pH, medical dosage, and preoxidation were examined. Cd complexation from contaminated L .  edodes was shown to be more efficient under acidic conditions (pH 5.0), with a clearance rate of 80.47% in 25 mmol/L EDTA and 78.45% in 25 mmol/L sodium citrate. The Cd content in the lentinan of the contaminated L. edodes was markedly lower than that in the powdered mushroom (2.77 mg/kg vs. 19.49 mg/kg) and was easier to remove. The maximum Cd clearance rate (96.3%) for lentinan was obtained using an optimized process that involved preoxidation with 0.5 mg/L KMnO 4 , complexing with 25 mmol/L EDTA and 25 mmol/L sodium citrate, and coagulation with 50 mg/L activated carbon (AC) at pH 10.0.

The impact of detergents on the tissue decellularization process: a ToF-SIMS study

PubMed Central

White, Lisa J; Taylor, Adam J; Faulk, Denver M; Keane, Tim J; Saldin, Lindsey T; Reing, Janet E; Swinehart, Ilea T; Turner, Neill J; Ratner, Buddy D

2017-01-01

Biologic scaffolds are derived from mammalian tissues, which must be decellularized to remove cellular antigens that would otherwise incite an adverse immune response. Although widely used clinically, the optimum balance between cell removal and the disruption of matrix architecture and surface ligand landscape remains a considerable challenge. Here we describe the use of time of flight secondary ion mass spectroscopy (ToF-SIMS) to provide sensitive, molecular specific, localized analysis of detergent decellularized biologic scaffolds. We detected residual detergent fragments, specifically from Triton X-100, sodium deoxycholate and sodium dodecyl sulphate (SDS) in decellularized scaffolds; increased SDS concentrations from 0.1% to 1.0% increased both the intensity of SDS fragments and adverse cell outcomes. We also identified cellular remnants, by detecting phosphate and phosphocholine ions in PAA and CHAPS decellularized scaffolds. The present study demonstrates ToF-SIMS is not only a powerful tool for characterization of biologic scaffold surface molecular functionality, but also enables sensitive assessment of decellularization efficacy. PMID:27993639

Test Report for Permanganate and Cold Strontium Strike for Tank 241-AN-102

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

Duncan, James B.; Huber, Heinz J.; Smalley, Colleen S.

Tanks 241-AN-102 and 241-AN-107 supernatants contain soluble Sr-90 and transuranic elements that require removal prior to vitrification to comply with the Waste Treatment and Immobilization Plant immobilized low-activity waste specification (WTP Contract, DE-AC27-01RV 14136, Specification 2.2.2.8, "Radionuclide Concentration Limitations") and the U.S. Nuclear Regulatory Commission provisional agreement on waste incidental to reprocessing (letter, Paperiello, C. J., "Classification of Hanford Low-Activity Tank Waste Fraction"). These two tanks have high concentrations of organics and organic complexants and are referred to as complexant concentrate tanks. A precipitation process using sodium permanganate (NaMnO{sub 4}) and strontium nitrate (Sr(NO{sub 3}){sub 2}) was developed and testedmore » with tank waste samples to precipitate Sr-90 and transuranic elements from the supernate (PNWD-3141, Optimization of Sr/TRU Removal Conditions with Samples of AN-102 Tank Waste). Testing documented in this report was conducted to further evaluate the use of the strontium nitrate/sodium permanganate process in tank farms with a retention time of up to 12 months. Previous testing was focused on developing a process for deployment in the ultrafiltration vessels in the Waste Treatment and Immobilization Plant. This environment is different from tank farms in two important ways: the waste is diluted in the Waste Treatment and Immobilization Plant to ~5.5 M sodium, whereas the supernate in the tank farms is ~9 M Na. Secondly, while the Waste Treatment and Immobilization Plant allows for a maximum treatment time of hours to days, the in-tank farms treatment of tanks 241-AN102 and 241-AN-107 will result in a retention time of months (perhaps up to12 months) before processing. A comparative compilation of separation processes for Sr/transuranics has been published as RPP-RPT-48340, Evaluation of Alternative Strontium and Transuranic Separation Processes. This report also listed the testing needs for the permanganate precipitation process to be field-deployable. A more comprehensive listing of future testing needs to allow the process to be field deployable are contained in RPP-PLAN-51288, Development Test Plan for Sr/TRU Precipitation Process.« less

76 FR 17026 - New Animal Drugs; Arsanilate Sodium; Sulfaethoxypyridazine

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-28

... [Docket No. FDA-2011-N-0003] New Animal Drugs; Arsanilate Sodium; Sulfaethoxypyridazine AGENCY: Food and... Administration (FDA) is amending the animal drug regulations to remove sections pertaining to use of arsanilate sodium and sulfaethoxypyridazine in medicated feed because there are no currently approved new animal...

The Effect of Carbonate, Oxalate and Peroxide on the Cesium Loading of Ionsiv IE-910 and IE-911

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

Fondeur, F.F.

2000-12-19

The Savannah River Site (SRS) continues to examine three processes for the removal of radiocesium from high-level waste. One option involves the use of crystalline silicotitanate (CST) as a non-elutable ion exchange medium. The process uses CST in its engineered form - IONSIV IE-911 made by UOP, LLC. - in a column to contact the liquid waste. Cesium exchanges with sodium ions residing inside the CST particles. The design disposes of the cesium-loaded CST by vitrification within the Defense Waste Processing Facility.

Pozzolanic filtration/solidification of radionuclides in nuclear reactor cooling water

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

Englehardt, J.D.; Peng, C.

1995-12-31

Laboratory studies to investigate the feasibility of one- and two-step processes for precipitation/coprecipitating radionuclides from nuclear reactor cooling water, filtering with pozzolanic filter aid, and solidifying, are reported in this paper. In the one-step process, ferrocyanide salt and excess lime are added ahead of the filter, and the resulting filter cake solidifies by a pozzolanic reaction. The two-step process involves addition of solidifying agents subsequent to filtration. It was found that high surface area diatomaceous synthetic calcium silicate powders, sold commercially as functional fillers and carriers, adsorb nickel isotopes from solution at neutral and slightly basic pH. Addition of themore » silicates to cooling water allowed removal of the tested metal isotopes (nickel, iron, manganese, cobalt, and cesium) simultaneously at neutral to slightly basic pH. Lime to diatomite ratio was the most influential characteristic of composition on final strength tested, with higher lime ratios giving higher strength. Diatomaceous earth filter aids manufactured without sodium fluxes exhibited higher pozzolanic activity. Pozzolanic filter cake solidified with sodium silicate and a ratio of 0.45 parts lime to 1 part diatomite had compressive strength ranging from 470 to 595 psi at a 90% confidence level. Leachability indices of all tested metals in the solidified waste were acceptable. In light of the typical requirement of removing iron and desirability of control over process pH, a two-step process involving addition of Portland cement to the filter cake may be most generally applicable.« less

Effects of cell volume changes on membrane ionic permeabilities and sodium transport in frog skin (Rana ridibunda).

PubMed

Costa, P M; Fernandes, P L; Ferreira, H G; Ferreira, K T; Giraldez, F

1987-12-01

1. Membrane potential and conductances and short-circuit current were continuously measured with microelectrodes and conventional electrophysiological techniques in a stripped preparation of frog skin epithelium. The effects of the removal of chloride or sodium ions and the concentration or dilution of the serosal (inner) bathing solution were studied. 2. Chloride- or sodium-free solutions produced a cell depolarization of about 30 mV in parallel with a fall in the short-circuit current. Mucosal and serosal membrane conductances both decreased and the sodium permeability of the mucosal barrier was calculated to fall to about one-half its value in standard Ringer solution. The observed decrease in the short-circuit current is probably related to the combined effect of the decrease in sodium permeability and the decrease in the driving force across the mucosal membrane. 3. The removal of chloride or sodium ions reduced the depolarization caused by serosal perfusion with high-potassium solutions (50 mM-KCl). The ratio of the change in cell membrane potential under short-circuit conditions to the change in the potassium equilibrium potential (delta Ec(s.c.)/delta EK), was 0.59 in standard Ringer solution and 0.26 and 0.24 after the removal of chloride or sodium respectively. The depolarizing effect of barium-containing solutions (2 mM-BaCl2) was also markedly reduced in chloride- or sodium-free solutions, suggesting a decrease of the potassium selectivity of the serosal membrane in these conditions. 4. Increasing the osmolality of the serosal bathing solution produced similar effects, i.e. cell depolarization, fall in the short-circuit current and membrane conductances and reduction of the depolarizing effect of high-potassium and barium solutions. On the contrary, dilution of the serosal bath produced the opposite effects, consistent with an increase in the serosal permeability to potassium. 5. The effects of chloride- or sodium-free solutions were reversed by the dilution of the serosal bath. Cells repolarized when exposed to low-osmolality solutions after being in the absence of serosal chloride or sodium. The repolarization ran in parallel with the restoration of the short-circuit current and the potassium selectivity of the serosal membrane. 6. The results show that the effects produced by the removal of sodium or chloride ions from the serosal bathing solution are most probably mediated by a reduction in cell volume. Cell volume changes would lead to changes in the serosal membrane selectivity to potassium and thus to changes in cell membrane potential and sodium transport.(ABSTRACT TRUNCATED AT 400 WORDS)

One-step selective electrokinetic removal of inorganic anions from small volumes and its application as sample clean-up for mass spectrometric techniques.

PubMed

Tubaon, Ria Marni; Haddad, Paul R; Quirino, Joselito P

2017-03-10

The presence of inorganic anions in a sample interferes with mass spectrometric (MS) analysis. Here, a simple method to remove these ions from a liquid sample in one-step is described. The inorganic anions present in a 50μL sample were extracted into a low pH solution inside a 200μm i.d.×33cm long capillary by the use of an electric field. The selective removal of unwanted anions and retention of target analytes was accomplished by control of the apparent electrophoretic velocities of anions and analytes at a boundary that separated the sample and extraction solution. No physical barrier (e.g., membrane) was required and with the boundary situated at the tip of the capillary, efficient removal of inorganic anions (e.g., >80% removal) and good recovery of target analytes (e.g., >80% recovery) were achieved. The time required for removal of the inorganic anions was found to depend on their initial concentrations. The removal process was investigated using different concentrations of bromide and nitrate (as potassium salts) and negatively chargeable drugs as target analytes. This micro-sample clean-up technique used no organic solvents and little consumables and was studied to the determination of 0.6μg/L arsenic and 8.3μg/L vanadium in 500mg/L sodium chloride using inductively coupled plasma MS and 50μM angiotensin I in 1000mg/L sodium chloride using electrospray ionisation MS. Micro-sample clean-up was performed for 45min at 3kV in both demonstrations. The calculated recoveries for the metals at trace levels were 110-130%, and for the peptide was 103.8%. Copyright © 2017 Elsevier B.V. All rights reserved.

EVALUATION OF ALTERNATIVE STRONIUM AND TRANSURANIC SEPARATION PROCESSES

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

SMALLEY CS

2011-04-25

In order to meet contract requirements on the concentrations of strontium-90 and transuranic isotopes in the immobilized low-activity waste, strontium-90 and transuranics must be removed from the supernate of tanks 241-AN-102 and 241-AN-107. The process currently proposed for this application is an in-tank precipitation process using strontium nitrate and sodium permanganate. Development work on the process has not proceeded since 2005. The purpose of the evaluation is to identify whether any promising alternative processes have been developed since this issue was last examined, evaluate the alternatives and the baseline process, and recommend which process should be carried forward.

Carbon Nanotubes Produced from Ambient Carbon Dioxide for Environmentally Sustainable Lithium-Ion and Sodium-Ion Battery Anodes

PubMed Central

2016-01-01

The cost and practicality of greenhouse gas removal processes, which are critical for environmental sustainability, pivot on high-value secondary applications derived from carbon capture and conversion techniques. Using the solar thermal electrochemical process (STEP), ambient CO2 captured in molten lithiated carbonates leads to the production of carbon nanofibers (CNFs) and carbon nanotubes (CNTs) at high yield through electrolysis using inexpensive steel electrodes. These low-cost CO2-derived CNTs and CNFs are demonstrated as high performance energy storage materials in both lithium-ion and sodium-ion batteries. Owing to synthetic control of sp3 content in the synthesized nanostructures, optimized storage capacities are measured over 370 mAh g–1 (lithium) and 130 mAh g–1 (sodium) with no capacity fade under durability tests up to 200 and 600 cycles, respectively. This work demonstrates that ambient CO2, considered as an environmental pollutant, can be attributed economic value in grid-scale and portable energy storage systems with STEP scale-up practicality in the context of combined cycle natural gas electric power generation. PMID:27163042

Removal of bromates from water

NASA Astrophysics Data System (ADS)

Barlokova, D.; Ilavsky, J.; Marko, I.; Tkacova, J.

2017-10-01

Bromates are substances that are usually not present in drinking water. They are obtained by ozone disinfection in the presence of bromine ions in water, as an impurity of sodium hypochlorite, respectively. Because of their specific properties, bromates are classified as vary dangers substances, that can cause serious illnesses in humans. There are several technological processes that have been used to the removal of bromates from water at present. In this article, the removal of the bromates from water by the adsorption using various sorbent materials (activated carbon, zeolite, Klinopur-Mn, Bayoxide E33, GEH, Read-As and Activated alumina) are presented. The effectiveness of selected sorbent materials in the removal of bromates from drinking water moves in the interval from 10 to 40%. Based on laboratory results, the zeolite can be used to reduce the concentration of bromates in water.

Performing Isoelectric Focusing and Simultaneous Fractionation of Proteins on A Rotary Valve Followed by Sodium Dodecyl – Polyacrylamide Gel Electrophoresis

PubMed Central

Wang, Wei; Lu, Joann J.; Gu, Congying; Zhou, Lei; Liu, Shaorong

2013-01-01

In this technical note, we design and fabricate a novel rotary valve and demonstrate its feasibility for performing isoelectric focusing and simultaneous fractionation of proteins, followed by sodium dodecyl – polyacrylamide gel electrophoresis. The valve has two positions. In one position, the valve routes a series of capillary loops together into a single capillary tube where capillary isoelectric focusing (CIEF) is performed. By switching the valve to another position, the CIEF-resolved proteins in all capillary loops are isolated simultaneously, and samples in the loops are removed and collected in vials. After the collected samples are briefly processed, they are separated via sodium dodecyl – polyacrylamide gel electrophoresis (SDS-PAGE, the 2nd-D separation) on either a capillary gel electrophoresis instrument or a slab-gel system. The detailed valve configuration is illustrated, and the experimental conditions and operation protocols are discussed. PMID:23819755

Sodium hypochlorite as an alternative to hydrogen peroxide in Fenton process for industrial scale.

PubMed

Behin, Jamshid; Akbari, Abbas; Mahmoudi, Mohsen; Khajeh, Mehdi

2017-09-15

In present work, the treatment of aromatic compounds of simulated wastewater was performed by Fenton and NaOCl/Fe 2+ processes. The model solution was prepared based on the wastewater composition of Diisocyanate unit of Karoon Petrochemical Company/Iran containing Diamino-toluenes, Nitro-phenol, Mononitro-toluene, Nitro-cresol, and Dinitro-toluene. Experiments were conducted in a batch mode to examine the effects of operating variables such as pH, oxidant dosages, ferrous ion concentration and numbers of feeding on COD removal. Taguchi experimental design was used to determine the optimum conditions. The COD removal efficiency under optimum conditions (suggested by Taguchi design) in Fenton and NaOCl/Fe 2+ processes was 88.7% and 83.4%, respectively. The highest contribution factor in Fenton process belongs to pH (47.47%) and in NaOCl/Fe 2+ process belongs to NaOCl/pollutants (50.26%). High regression coefficient (R 2 : 0.98) obtained for Taguchi method, indicates that models are statistically significant and are in well agreement with each other. The NaOCl/Fe 2+ process utilizing a conventional oxidant, in comparison to hydrogen peroxide, is an efficient cost effective process for COD removal from real wastewater, although the removal efficiency is not as high as in Fenton process; however it is a suitable process to replace Fenton process in industrial scale for wastewater involved aromatic compounds with high COD. This process was successfully applied in Karoon Petrochemical Company/Iran. Copyright © 2017 Elsevier Ltd. All rights reserved.

Formulation of an alginate-vineyard pruning waste composite as a new eco-friendly adsorbent to remove micronutrients from agroindustrial effluents.

PubMed

Vecino, X; Devesa-Rey, R; Moldes, A B; Cruz, J M

2014-09-01

The cellulosic fraction of vineyard pruning waste (free of hemicellulosic sugars) was entrapped in calcium alginate beads and evaluated as an eco-friendly adsorbent for the removal of different nutrients and micronutrients (Mg, P, Zn, K, N-NH4, SO4, TN, TC and PO4) from an agroindustrial effluent (winery wastewater). Batch adsorption studies were performed by varying the amounts of cellulosic adsorbent (0.5-2%), sodium alginate (1-5%) and calcium chloride (0.05-0.9M) included in the biocomposite. The optimal formulation of the adsorbent composite varied depending on the target contaminant. Thus, for the adsorption of cationic contaminants (Mg, Zn, K, N-NH4 and TN), the best mixture comprised 5% sodium alginate, 0.05M calcium chloride and 0.5% cellulosic vineyard pruning waste, whereas for removal of anionic compounds (P, SO4 and PO4), the optimal mixture comprised 1% sodium alginate, 0.9M calcium chloride and 0.5% cellulosic vineyard pruning waste. To remove TC from the winery wastewater, the optimal mixture comprised 3% of sodium alginate, 0.475M calcium chloride and 0.5% cellulosic vineyard pruning waste. Copyright © 2014 Elsevier Ltd. All rights reserved.

Inhibition of boric acid and sodium borate on the biological activity of microorganisms in an aerobic biofilter.

PubMed

Güneş, Y

2013-01-01

The aim of this work was to study the inhibition effect of boric acid and sodium borate on the treatment of boron containing synthetic wastewater by a down flow aerobic fixed bed biofilm reactor at various chemical oxygen demand (COD)/boron ratios (0.47-20.54). The inhibitory effect of boron on activated sludge was evaluated on the basis of COD removal during the experimental period. The biofilter (effective volume = 2.5 L) was filled with a ring of plastic material inoculated with acclimated activated sludge. The synthetic wastewater composed of glucose, urea, KH2PO4, MgSO4, Fe2 SO4, ZnSO4 x 7H20, KCl, CaCl2, and di-sodium tetraborate decahydrate or boric acid (B = 100-2000 mg L(-1)). The biological treatment of boron containing wastewater resulted in a low treatment removal rate due to the reduced microbial activity as a result of toxic effects of high boron concentrations. The decrease in the COD removal rate by the presence of either boric acid or sodium borate was practically indistinguishable. It was observed from the experiments that about 90-95% of COD removal was possible at high COD/boron ratios.

SOLIDIFICATION OF THE HANFORD LAW WASTE STREAM PRODUCED AS A RESULT OF NEAR-TANK CONTINUOUS SLUDGE LEACHING AND SODIUM HYDROXIDE RECOVERY

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

Reigel, M.; Johnson, F.; Crawford, C.

2011-09-20

The U.S. Department of Energy (DOE), Office of River Protection (ORP), is responsible for the remediation and stabilization of the Hanford Site tank farms, including 53 million gallons of highly radioactive mixed wasted waste contained in 177 underground tanks. The plan calls for all waste retrieved from the tanks to be transferred to the Waste Treatment Plant (WTP). The WTP will consist of three primary facilities including pretreatment facilities for Low Activity Waste (LAW) to remove aluminum, chromium and other solids and radioisotopes that are undesirable in the High Level Waste (HLW) stream. Removal of aluminum from HLW sludge canmore » be accomplished through continuous sludge leaching of the aluminum from the HLW sludge as sodium aluminate; however, this process will introduce a significant amount of sodium hydroxide into the waste stream and consequently will increase the volume of waste to be dispositioned. A sodium recovery process is needed to remove the sodium hydroxide and recycle it back to the aluminum dissolution process. The resulting LAW waste stream has a high concentration of aluminum and sodium and will require alternative immobilization methods. Five waste forms were evaluated for immobilization of LAW at Hanford after the sodium recovery process. The waste forms considered for these two waste streams include low temperature processes (Saltstone/Cast stone and geopolymers), intermediate temperature processes (steam reforming and phosphate glasses) and high temperature processes (vitrification). These immobilization methods and the waste forms produced were evaluated for (1) compliance with the Performance Assessment (PA) requirements for disposal at the IDF, (2) waste form volume (waste loading), and (3) compatibility with the tank farms and systems. The iron phosphate glasses tested using the product consistency test had normalized release rates lower than the waste form requirements although the CCC glasses had higher release rates than the quenched glasses. However, the waste form failed to meet the vapor hydration test criteria listed in the WTP contract. In addition, the waste loading in the phosphate glasses were not as high as other candidate waste forms. Vitrification of HLW waste as borosilicate glass is a proven process; however the HLW and LAW streams at Hanford can vary significantly from waste currently being immobilized. The ccc glasses show lower release rates for B and Na than the quenched glasses and all glasses meet the acceptance criterion of < 4 g/L. Glass samples spiked with Re{sub 2}O{sub 7} also passed the PCT test. However, further vapor hydration testing must be performed since all the samples cracked and the test could not be performed. The waste loading of the iron phosphate and borosilicate glasses are approximately 20 and 25% respectively. The steam reforming process produced the predicted waste form for both the high and low aluminate waste streams. The predicted waste loadings for the monolithic samples is approximately 39%, which is higher than the glass waste forms; however, at the time of this report, no monolithic samples were made and therefore compliance with the PA cannot be determined. The waste loading in the geopolymer is approximately 40% but can vary with the sodium hydroxide content in the waste stream. Initial geopolymer mixes revealed compressive strengths that are greater than 500 psi for the low aluminate mixes and less than 500 psi for the high aluminate mixes. Further work testing needs to be performed to formulate a geopolymer waste form made using a high aluminate salt solution. A cementitious waste form has the advantage that the process is performed at ambient conditions and is a proven process currently in use for LAW disposal. The Saltstone/Cast Stone formulated using low and high aluminate salt solutions retained at least 97% of the Re that was added to the mix as a dopant. While this data is promising, additional leaching testing must be performed to show compliance with the PA. Compressive strength tests must also be performed on the Cast Stone monoliths to verify PA compliance. Based on testing performed for this report, the borosilicate glass and Cast Stone are the recommended waste forms for further testing. Both are proven technologies for radioactive waste disposal and the initial testing using simulated Hanford LAW waste shows compliance with the PA. Both are resistant to leaching and have greater than 25% waste loading.« less

PROCESS FOR SEPARATION OF HEAVY METALS

DOEpatents

Duffield, R.B.

1958-04-29

A method is described for separating plutonium from aqueous acidic solutions of neutron-irradiated uranium and the impurities associated therewith. The separation is effected by adding, to the solution containing hexavalent uranium and plutonium, acetate ions and the ions of an alkali metal and those of a divalent metal and thus forming a complex plutonium acetate salt which is carried by the corresponding complex of uranium, such as sodium magnesium uranyl acetate. The plutonium may be separated from the precipitated salt by taking the same back into solution, reducing the plutonium to a lower valent state on reprecipitating the sodium magnesium uranyl salt, removing the latter, and then carrying the plutonium from ihe solution by means of lanthanum fluoride.

Method for mobilization of hazardous metal ions in soils

DOEpatents

Dugan, P.R.; Pfister, R.M.

1995-06-27

A microbial process is revealed for removing heavy metals such as bismuth, cadmium, lead, thorium, uranium and other transuranics from soils and sediments. The method utilizes indigenous, or isolates of indigenous, microorganisms and reducing agents, such as cysteine or sodium thioglycollate, or complexing agents such as the amino acid glycine, to effect the mobilization or release of the metals from the soil particles. 5 figs.

Experiment on the treatment of waste extraction solvent from the molybdenum-99 process

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

Hsien-Ming Hsiao; Chang-Liang Hu; Kuang-Li Chien

2013-07-01

In the Mo-99 (Molybdenum-99) isotope extraction test process for radiopharmaceutical applications, organic solvent is used to extract Mo-99 from an irradiated UO{sub 2} dissolution. The extraction solvent was stored when the test work was stopped. A total of about 120 liters of waste solvent was stored at INER (Institute of Nuclear Energy Research, Taiwan). The extraction solvent consisted of 5% di-(2-ethylhexyl)-phosphoric acid (D2EHPA) and kerosene. The radionuclides found in the waste solvent include Cs-137, Am-241, Tc-99, and Sr-90, which give off gross alpha and beta radioactivity of 1898 and 471 Bq/ml, respectively. This study aims to remove radionuclides from themore » waste solvent using sodium carbonate and sodium hydroxide solutions in different concentrations. After mixing the waste solvent with the alkaline solution followed by settling, a third phase other than organic and aqueous phase appeared which is expected due to the saponification reaction. The experimental results showed that increasing the number of washing and the alkaline solution concentration could enhance the radionuclides removal rate. An optimal removal method was proposed using 2 M Na{sub 2}CO{sub 3} solution twice followed by 1 M NaOH solution one time for the third phase generated early in the mixing stages. The remaining gross alpha and beta radioactivity of the treated organic solvent was 2 and 3 Bq/ml, respectively. The treated solvent could be stabilized by ashing at 500 deg. C and then immobilized. The alkaline solution would be neutralized by hydrochloric or nitric acid and then treated using a variety of adsorbents or bone char via adsorption to remove nuclides to meet the wastewater discharge limitation. (authors)« less

LOW ACTIVITY WASTE FEED SOLIDS CARACTERIZATION AND FILTERABILITY TESTS

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

McCabe, D.; Crawford, C.; Duignan, M.

The primary treatment of the tank waste at the DOE Hanford site will be done in the Waste Treatment and Immobilization Plant (WTP) that is currently under construction. The baseline plan for the WTP Pretreatment facility is to treat the waste, splitting it into High Level Waste (HLW) feed and Low Activity Waste (LAW) feed. Both waste streams are then separately vitrified as glass and sealed in canisters. The LAW glass will be disposed onsite in the Integrated Disposal Facility (IDF). There are currently no plans to treat the waste to remove technetium in the WTP Pretreatment facility, so itsmore » disposition path is the LAW glass. Options are being explored to immobilize the LAW portion of the tank waste, i.e., the LAW feed from the WTP Pretreatment facility. Removal of {sup 99}Tc from the LAW Feed, followed by off-site disposal of the {sup 99}Tc, would eliminate a key risk contributor for the IDF Performance Assessment (PA) for supplemental waste forms, and has potential to reduce treatment and disposal costs. Washington River Protection Solutions (WRPS) is developing some conceptual flow sheets for LAW treatment and disposal that could benefit from technetium removal. One of these flowsheets will specifically examine removing {sup 99}Tc from the LAW feed stream to supplemental immobilization. The conceptual flow sheet of the {sup 99}Tc removal process includes a filter to remove insoluble solids prior to processing the stream in an ion exchange column, but the characteristics and behavior of the liquid and solid phases has not previously been investigated. This report contains results of testing of a simulant that represents the projected composition of the feed to the Supplemental LAW process. This feed composition is not identical to the aqueous tank waste fed to the Waste Treatment Plant because it has been processed through WTP Pretreatment facility and therefore contains internal changes and recycle streams that will be generated within the WTP process. Although a Supplemental LAW feed simulant has previously been prepared, this feed composition differs from that simulant because those tests examined only the fully soluble aqueous solution at room temperature, not the composition formed after evaporation, including the insoluble solids that precipitate after it cools. The conceptual flow sheet for Supplemental LAW immobilization has an option for removal of {sup 99}Tc from the feed stream, if needed. Elutable ion exchange has been selected for that process. If implemented, the stream would need filtration to remove the insoluble solids prior to processing in an ion exchange column. The characteristics, chemical speciation, physical properties, and filterability of the solids are important to judge the feasibility of the concept, and to estimate the size and cost of a facility. The insoluble solids formed during these tests were primarily natrophosphate, natroxalate, and a sodium aluminosilicate compound. At the elevated temperature and 8 M [Na+], appreciable insoluble solids (1.39 wt%) were present. Cooling to room temperature and dilution of the slurry from 8 M to 5 M [Na+] resulted in a slurry containing 0.8 wt% insoluble solids. The solids (natrophosphate, natroxalate, sodium aluminum silicate, and a hydrated sodium phosphate) were relatively stable and settled quickly. Filtration rates were in the range of those observed with iron-based simulated Hanford tank sludge simulants, e.g., 6 M [Na+] Hanford tank 241-AN-102, even though their chemical speciation is considerably different. Chemical cleaning of the crossflow filter was readily accomplished with acid. As this simulant formulation was based on an average composition of a wide range of feeds using an integrated computer model, this exact composition may never be observed. But the test conditions were selected to enable comparison to the model to enable improving its chemical prediction capability.« less

Fluorescein sodium-guided surgery of a brain abscess: A case report

PubMed Central

Höhne, Julius; Brawanski, Alexander; Schebesch, Karl-Michael

2016-01-01

Background: Up to now, the feasibility and benefit of using fluorescein sodium under a dedicated surgical microscope filter (YE560, YELLOW 560 nm filter, Carl Zeiss Meditec, Germany) has never been clinically evaluated in infectious disorders of the brain. Case Description: Here, we report the case of a male patient with a brain abscess in the right parietal lobe that was removed under fluorescence-guidance (intravenous administration of fluorescein sodium 10%, 5 mg/kg bodyweight). The abscess capsule showed intensive yellow fluorescent staining, while − under white light − the cortex appeared normal. Conclusion: This technique may improve the identification and surgical removal of brain abscesses. PMID:28031990

Treatment of oily wastewater of a gas refinery by electrocoagulation using aluminum electrodes.

PubMed

Saeedi, Mohesn; Khalvati-Fahlyani, Amin

2011-03-01

Oily wastewaters are the most important discharges of gas refineries from an environmental point-of-view. In the present study, treatment of gas refinery oily wastewater by electrocoagulation using aluminum electrodes was investigated. The effects of electrode distance, initial pH, sodium sulfate (Na2SO4) as a supporting electrolyte, polyaluminum chloride dosage as a coagulant aid, and current density on the efficiency of chemical oxygen demand (COD) removal were examined. The results revealed that the COD removal rate increases by applying more current density and polyaluminum chloride and, to a lesser extent, Na2SO4 dosage. The results also showed that 97% COD can be removed at optimum operational conditions. Specific electrical energy consumption could be reduced from 19.48 kWh (kg COD removal)(-1) to 11.057 kWh (kg COD removal)(-1) using Na2SO4 as a supporting electrolyte. Gas chromatographic analysis of raw and treated wastewater also revealed that most normal hydrocarbons (nearly 99%) were removed during the electrocoagulation process.

Efficacy of Sodium Hypochlorite Activated With Laser in Intracanal Smear Layer Removal: An SEM Study

PubMed Central

Shahriari, Shahriar; Kasraei, Shahin; Roshanaei, Ghodratollah; Karkeabadi, Hamed; Davanloo, Hossein

2017-01-01

Introduction: The purpose of the present study was to evaluate the different concentrations of sodium hypochlorite activated with laser in removing of the smear layer in the apical, middle, and coronal segments of root canal walls by scanning electron microscopy analysis. Methods: Sixty single-rooted human mandibular teeth were decoronated to a standardized length. The samples were prepared by using Race rotary system to size 40, 0.04 taper and divided into 4 equal groups (n = 15). Group 1, irrigated with EDTA 17% and 5.25% NaOCl, groups 2, 3 and 4, 1%, 2.5%, and 5% NaOCl activated with Nd:YAG laser, respectively. Teeth were split longitudinally and subjected to scanning electron microscope (SEM). Data were analyzed by Kruskal-Wallis, Mann-Whitney tests. P value of <0.05 was considered statistically significant. Results: Five percent NaOCl LAI (laser-activated irrigation) showed best smear layer removal in test groups and the difference was statistically significant (P < 0.001). Control group (EDTA 17% and 5.25% NaOCl irrigation) showed significantly better outcomes in comparative with test groups (P < 0.001). In the apical third, compared to coronal and middle third, the canal walls were often contaminated by inorganic debris and smear layer. Conclusion: All different concentrations of sodium hypochlorite activated with laser have a positive effect on removing of smear layer. Sodium hypochlorite activated with laser removed smear layer more effectively at the coronal and middle third compared to the apical third. PMID:28912942

The problems of using a high-temperature sodium coolant in nuclear power plants for the production of hydrogen and other innovative applications

NASA Astrophysics Data System (ADS)

Sorokin, A. P.; Alexeev, V. V.; Kuzina, Ju. A.; Konovalov, M. A.

2017-11-01

The intensity of the hydrogen sources arriving from the third contour of installation in second in comparison with the hydrogen sources on NPP BN-600 increases by two - three order at using of high-temperature nuclear power plants with the sodium coolant (HT-NPP) for drawing of hydrogen and other innovative applications (gasification and a liquefaction of coal, profound oil refining, transformation of biomass to liquid fuel, in the chemical industry, metallurgy, the food-processing industry etc.). For these conditions basic new technological solutions are offered. The main condition of their implementation is raise of hydrogen concentration in the sodium coolant on two - three order in comparison with the modern NPP, in a combination to hydrogen removal from sodium and its pumping out through membranes from vanadium or niobium. The researches with use diffusive model have shown possibility to expel a casium inflow in sodium through a leakproof shell of fuel rods if vary such parameters as a material of fuel rods shell, its thickness and maintenance time at design of fuel rods for high-temperature NPP. However maintenance of high-temperature NPP in the presence of casium in sodium is inevitable at loss of leakproof of a fuel rods shell. In these conditions for minimisation of casium diffusion in structural materials it is necessary to provide deep clearing of sodium from cesium.

Removal of Salmonella Enteritidis from commercial unpasteurized liquid egg white using pilot scale cross flow tangential microfiltration.

PubMed

Mukhopadhyay, Sudarsan; Tomasula, Peggy M; Luchansky, John B; Porto-Fett, Anna; Call, Jeffrey E

2010-09-01

Effectiveness of a cross flow microfiltration (MF) process for removal of a cocktail of Salmonella enterica serovar Enteritidis species from commercial unpasteurized liquid egg white (LEW) from a local egg breaking plant, while maintaining its functional properties was evaluated. To facilitate MF, LEW was wedge screened, homogenized and then diluted (1:2 w/w) with distilled water containing 0.5% sodium chloride. Diluted unpasteurized LEW was inoculated with five strains of S. Enteritidis (ATCC 4931, ATCC BAA-708, ATCC 49215, ATCC 49218, and ATCC BAA-1045) to a level of approximately 10(7)CFU/mL of LEW and microfiltered using a ceramic membrane. Process parameters influencing egg white functional properties and pathogen removal efficiency were evaluated. Average permeates flux increased by almost 126% when pH of LEW was adjusted from pH 8 to pH 7 at 25 degrees C. Microbial removal efficiency was at least, on average, 6.8Log(10)CFU/mL (limit of detection < or =0.5Log(10)CFU/mL). Functional property analysis indicated that the MF process did not alter the foaming power of LEW. Published by Elsevier B.V.

Chloride removal from recycled cooling water using ultra-high lime with aluminum process.

PubMed

Abdel-Wahab, Ahmed; Batchelor, Bill

2002-01-01

Chloride is a deleterious ionic species in cooling water systems because it promotes corrosion, and most of the scale and corrosion inhibitors are sensitive to chloride concentration in the water. Chloride can be removed from cooling water by precipitation as calcium chloroaluminate [Ca4Al2Cl2(OH)12]. A set of equilibrium experiments and one kinetic experiment were conducted to evaluate chloride removal using the ultra-high lime with aluminum (UHLA) process and to characterize the equilibrium conditions of calcium chloroaluminate precipitation. A total of 48 batch-equilibrium experiments were conducted on a 30 mM NaCl solution over a range of values for lime dose (0 to 200 mM) and sodium aluminate dose (0 to 100 mM). Experimental results showed that the UHLA process can remove chloride and that the formation of a calcium chloroaluminate solid phase is a reasonable mechanism that is able to adequately describe experimental results. An average value of the ion activity product of 10(-94.75) was obtained and can be used as an estimate of the solubility product for Ca4Al2Cl2(OH)12.

Development and Characterization of a High-Solids Deacetylation Process

DOE PAGES

Shekiro, III, Joseph; Chen, Xiaowen; Smith, Holly; ...

2016-05-20

Dilute-acid pretreatment has proven to be a robust means of converting herbaceous feedstock to fermentable sugars. However, it also releases acetic acid, a known fermentation inhibitor, from acetyl groups present in the biomass. A mild, dilute alkaline extraction stage was implemented prior to acid pretreatment to separate acetic acid from the hydrolysate sugar stream. This step, termed deacetylation, improved the glucose and xylose yields from enzymatic hydrolysis and ethanol yields from fermentation of the sugars relative to the control experiments using dilute-acid pretreatment of native corn stover without deacetylation. While promising, deacetylation as it was historically practiced is conducted atmore » low solids loadings, and at fixed conditions. Thus, many questions have been left unanswered, including the relationship between sodium hydroxide and solids loading, and acetate and xylan solubilization, as well as the impact of temperature and residence time on the process efficacy. A central composite experiment was designed to evaluate the impact of solids loading, sodium hydroxide loading, reaction time and temperature during deacetylation on the acetate and xylan solubilization of corn stover. Using the ANOVA test, it became apparent that neither of the responses was significantly impacted by the solids loading, while the reaction time was a minor factor - the responses were largely driven by reaction temperature and the sodium hydroxide loading. Based on the results, we successfully demonstrated the ability to transition the low-solids (10 % w/w) deacetylation process to a higher-solids process (30 % w/w) with minimal impact on the ability to extract acetate from biomass. Conditions were selected to minimize xylose loss during deacetylation, while also removing 70 % of acetyl groups. The impact of selected conditions on the enzymatic hydrolysis and fermentation was further investigated. In conclusion, evaluation of the whole-process impact demonstrated that despite the upfront reduction in carbohydrate loss during deacetylation, the overall process sugar yields were depressed by the high-solids, low alkali process relative to the historical control. Consequently, ethanol titers were reduced, though strong fermentation performance was still observed, indicating that 70 % acetate removal is sufficient to depress acetic acid concentrations to a level that does not substantially inhibit ethanol fermentation by rZymomo nas.« less

Aqueous sodium borohydride induced thermally stable porous zirconium oxide for quick removal of lead ions

PubMed Central

Nayak, Nadiya B.; Nayak, Bibhuti B.

2016-01-01

Aqueous sodium borohydride (NaBH4) is well known for its reducing property and well-established for the development of metal nanoparticles through reduction method. In contrary, this research paper discloses the importance of aqueous NaBH4 as a precipitating agent towards development of porous zirconium oxide. The boron species present in aqueous NaBH4 play an active role during gelation as well as phase separated out in the form of boron complex during precipitation, which helps to form boron free zirconium hydroxide [Zr(OH)4] in the as-synthesized condition. Evolved in-situ hydrogen (H2) gas-bubbles also play an important role to develop as-synthesized loose zirconium hydroxide and the presence of intra-particle voids in the loose zirconium hydroxide help to develop porous zirconium oxide during calcination process. Without any surface modification, this porous zirconium oxide quickly adsorbs almost hundred percentages of toxic lead ions from water solution within 15 minutes at normal pH condition. Adsorption kinetic models suggest that the adsorption process was surface reaction controlled chemisorption. Quick adsorption was governed by surface diffusion process and the adsorption kinetic was limited by pore diffusion. Five cycles of adsorption-desorption result suggests that the porous zirconium oxide can be reused efficiently for removal of Pb (II) ions from aqueous solution. PMID:26980545

Radiochemical micro assays for the determination of choline acetyltransferase and acetylcholinesterase activities

PubMed Central

Fonnum, F.

1969-01-01

1. The methods for the assay of choline acetyltransferase were based on the reaction between labelled acetyl-CoA and unlabelled choline to give labelled acetylcholine. 2. Both synthetic acetyl-CoA and acetyl-CoA formed from sodium [1-14C]acetate or sodium [3H]acetate by incubation with CoA, ATP, Mg2+ and extract from acetone-dried pigeon liver were used. 3. [1-14C]Acetylcholine was isolated by extraction with ketonic sodium tetraphenylboron. 4. [3H]Acetylcholine was precipitated with sodium tetraphenylboron to remove a ketone-soluble contaminant in sodium [3H]acetate and then extracted with ketonic sodium tetraphenylboron. 5. The values of choline acetyltransferase activity obtained in the presence of sodium cyanide or EDTA and synthetic acetyl-CoA were similar to those obtained with acetyl-CoA synthesized in situ. 6. The assay of acetylcholinesterase was based on the formation of labelled acetate from labelled acetylcholine. The labelled acetylcholine could be quantitatively removed from the acetate by extraction with ketonic sodium tetraphenylboron. 7. The methods were tested with samples from central and peripheral nervous tissues and purified enzymes. 8. The blank values for choline acetyltransferase and acetylcholinesterase corresponded to the activities in 20ng. and 5ng. of brain tissue respectively. PMID:4982085

Analysis of metal Bioleaching from thermal power plant fly ash by Aspergillus niger 34770 culture supernatant and reduction of phytotoxicity during the process.

PubMed

Jadhav, Umesh U; Hocheng, Hong

2015-01-01

Aspergillus niger culture supernatant is used for bioleaching process. Before starting bioleaching process, fly ash was washed with distilled water. This removed 100 % sodium, 47 % (±0.45) boron, 38.07 % (±0.12) calcium, 29.89 % (±0.78) magnesium, and 11.8 % (±0.05) potassium. The pH was reduced from 10.5 to 8.5 after water washing. During bioleaching process, around 100 % metal removal was achieved in 4 h for all metals except chromium 93 % (±1.18), nickel 83 % (±0.32), arsenic 78 % (±0.52), and lead 70 % (±0.20). The process parameters including temperature, shaking speed, and solid/liquid ratio were optimized for bioleaching process. Experiments were conducted to evaluate effect of fly ash on growth of mung bean (Vigna radiata). At 20 g/100 ml fly ash concentration no germination of V. radiata seeds was observed. With an increasing concentration of untreated fly ash, a gradual decrease in root/shoot length was observed. After bioleaching process 78 % (±0.19) germination of V. radiata was observed with 20 g/100 ml fly ash. This study will help to develop an efficient process to remove the toxic metals from fly ash.

Impacts of sodium hydroxide and sodium hypochlorite aging on polyvinylidene fluoride membranes fabricated with different methods.

PubMed

Wu, Qilong; Zhang, Xihui; Cao, Guodong

2018-05-01

This study compared the effects of chemical aging on the polyvinylidene fluoride (PVDF) membranes fabricated with the methods of non-solvent induced phase separation (NIPS) (named NIPS-PVDF) and thermally induced phase separation (TIPS) (named TIPS-PVDF). The chemical solutions of sodium hypochlorite (NaClO) and sodium hydroxide (NaOH) were chosen at the concentration of 5000mg/L. The equivalence of 5 and 10years was respectively selected as the time of aging. The physicochemical evolutions of membrane aging are characterized on the base of morphology analysis, chemical components, permeation ability and mechanical properties. The aging of NIPS-PVDF membrane led to the elimination of surface hydrophilic additives, while NaOH focused on the dehydrofluorination process resulting in the formation of conjugated chains of polyene on the skeleton structure. The chemical components of the surface of TIPS-PVDF membrane were removed continuously during the aging processes of both NaClO and NaOH, which was caused by the saponification of surface additives and the chain scissions of skeleton structure, but without producing any obvious conjugated chains of polyene. All the aging processes led to the increase of contact angle and the decrease of mechanical properties, and the permeability was reduced first and increased later due to the enlargement of surface membrane pores and membrane block. With the influence of membrane aging, selectivity of membrane was decreased (except coliform bacteria). At the beginning of filtration, the turbidity and particle count were at relatively high levels and declined with the filtration process. Copyright © 2017. Published by Elsevier B.V.

Using GC-FID to Quantify the Removal of 4-sec-Butylphenol from NGS Solvent by NaOH

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

Sloop, Jr., Frederick V.; Moyer, Bruce A.

2014-12-01

A caustic wash of the solvent used in the Next-Generation Caustic-Side Solvent Extraction (NG-CSSX) process was found to remove the modifier breakdown product 4-sec-butylphenol (SBP) with varying efficiency depending on the aqueous NaOH concentration. Recent efforts at ORNL have aimed at characterizing the flowsheet chemistry and reducing the technical uncertainties of the NG-CSSX process. One technical uncertainty has been the efficacy of caustic washing of the solvent for the removal of lipophilic anions, in particular, the efficient removal of SBP, an important degradation product of the solvent modifier, Cs-7SB. In order to make this determination, it was necessary to developmore » a sensitive and reliable analytical technique for the detection and quantitation of SBP. This report recounts the development of a GC-FID-based (Gas Chromatography Flame Ionization Detection) technique for analyzing SBP and the utilization of the technique to subsequently confirm the ability of the caustic wash to efficiently remove SBP from the Next Generation Solvent (NGS) used in NG-CSSX. In particular, the developed technique was used to monitor the amount of SBP removed from a simple solvent and the full NGS by contact with sodium hydroxide wash solutions over a range of concentrations. The results show that caustic washing removes SBP with effectively the same efficiency as it did in the original Caustic-Side Solvent Extraction (CSSX) process.« less

APPLICATION OF VACUUM SALT DISTILLATION TECHNOLOGY FOR THE REMOVAL OF FLUORIDE AND CHLORIDE FROM LEGACY FISSILE MATERIALS

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

Pierce, R.; Peters, T.

2011-11-01

Between September 2009 and January 2011, the Savannah River National Laboratory (SRNL) and the Savannah River Site (SRS) HB-Line Facility designed, developed, tested, and successfully deployed a production-scale system for the distillation of sodium chloride (NaCl) and potassium chloride (KCl) from plutonium oxide (PuO{sub 2}). Subsequent efforts adapted the vacuum salt distillation (VSD) technology for the removal of chloride and fluoride from less-volatile halide salts at the same process temperature and vacuum. Calcium chloride (CaCl{sub 2}), calcium fluoride (CaF{sub 2}), and plutonium fluoride (PuF{sub 3}) were of particular concern. To enable the use of the same operating conditions for themore » distillation process, SRNL employed in situ exchange reactions to convert the less-volatile halide salts to compounds that facilitated the distillation of halide without removal of plutonium. SRNL demonstrated the removal of halide from CaCl{sub 2}, CaF{sub 2} and PuF{sub 3} below 1000 C using VSD technology.« less

Removal of sodium chloride from human urine via batch recirculation electrodialysis at constant applied voltage

NASA Technical Reports Server (NTRS)

Gordils-Striker, Nilda E.; Colon, Guillermo

2003-01-01

The removal of sodium chloride (NaCl) from human urine using a six-compartment electrodialysis cell with batch recirculation mode of operation for use in advanced life support systems (ALSS) was studied. From the results obtained, batch recirculation at constant applied voltage yields high values (approximately 94% of NaCl removal. Based on the results, the initial rate of NaCl removal was correlated to a power function of the applied voltage: -r=2.0 x 10(-4)E(3.8). With impedance spectroscopy methods, it was also found that the anion membranes were more affected by fouling with an increase of the ohmic resistance of almost 11% compared with 7.4% for the cationic ones.

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

Muth, Thomas R; Yamamoto, Yukinori; Frederick, David Alan

ORNL undertook an investigation using gas tungsten arc (GTA) welding on consolidated powder metallurgy (PM) titanium (Ti) plate, to identify the causal factors behind observed porosity in fusion welding. Tramp element compounds of sodium and magnesium, residual from the metallothermic reduction of titanium chloride used to produce the titanium, were remnant in the starting powder and were identified as gas forming species. PM-titanium made from revert scrap where sodium and magnesium were absent, showed fusion weld porosity, although to a lesser degree. We show that porosity was attributable to hydrogen from adsorbed water on the surface of the powders priormore » to consolidation. The removal / minimization of both adsorbed water on the surface of titanium powder and the residues from the reduction process prior to consolidation of titanium powders, are critical to achieve equivalent fusion welding success similar to that seen in wrought titanium produced via the Kroll process.« less

Causal Factors of Weld Porosity in Gas Tungsten Arc Welding of Powder-Metallurgy-Produced Titanium Alloys

NASA Astrophysics Data System (ADS)

Muth, T. R.; Yamamoto, Y.; Frederick, D. A.; Contescu, C. I.; Chen, W.; Lim, Y. C.; Peter, W. H.; Feng, Z.

2013-05-01

An investigation was undertaken using gas tungsten arc (GTA) welding on consolidated powder metallurgy (PM) titanium (Ti) plate to identify the causal factors behind observed porosity in fusion welding. Tramp element compounds of sodium and magnesium, residual from the metallothermic reduction of titanium chloride used to produce the titanium, were remnant in the starting powder and were identified as gas-forming species. PM-titanium made from revert scrap, where sodium and magnesium were absent, showed fusion weld porosity, although to a lesser degree. We show that porosity was attributable to hydrogen from adsorbed water on the surface of the powders prior to consolidation. The removal and minimization of both adsorbed water on the surface of titanium powder and the residues from the reduction process prior to consolidation of titanium powders are critical for achieving equivalent fusion welding success similar to that seen in wrought titanium produced via the Kroll process.

Toxicity of naproxen sodium and its mixture with tramadol hydrochloride on fish early life stages.

PubMed

Sehonova, Pavla; Plhalova, Lucie; Blahova, Jana; Doubkova, Veronika; Prokes, Miroslav; Tichy, Frantisek; Fiorino, Emma; Faggio, Caterina; Svobodova, Zdenka

2017-12-01

Pharmaceuticals occur in water bodies as a consequence of their incomplete removal during waste water treatment processes. The occurence of pharmaceuticals in surface waters as well as their possible impact on aquatic vertebrates have received considerable attention in recent years. However, there is still a lack of informations on the chronic effects of widely used drugs as well as their possible mixture toxicity on non-target aquatic vertebrates as well as their possible mixture toxicity. The aim of this study was to assess the effects of naproxen sodium on early life stages of fish and evaluate its mixture toxicity with tramadol hydrochloride, which was assessed in our earlier study as a single substance. Two embryo-larval toxicity tests with common carp (Cyprinus carpio) were performed according to the OECD guideline 210 (Fish, Early-life Stage Toxicity Test) in order to assess the subchronic toxicity of naproxen sodium and tramadol hydrochlorid-naproxen sodium mixture at the concentrations of 10; 50; 100 and 200 μg/L. These experiments were conducted for 32 days. The subchronic exposure to naproxen sodium and naproxen sodium and tramadol hydrochloride mixture had a strong effect on the early life stages of common carp. Hatching, developmental rate, morphology, histopathology and, in the case of the naproxen sodium and tramadol hydrochloride mixture, mortality were influenced. The bioindicators of oxidative stress were also influenced. The LOEC was determined at 10 μg/L for both naproxen sodium and naproxen sodium and tramadol hydrochloride mixture. Copyright © 2017 Elsevier Ltd. All rights reserved.

CHARACTERIZATION OF TANK 16H ANNULUS SAMPLES PART II: LEACHING RESULTS

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

Hay, M.; Reboul, S.

2012-06-19

The closure of Tank 16H will require removal of material from the annulus of the tank. Samples from Tank 16H annulus were characterized and tested to provide information to evaluate various alternatives for removing the annulus waste. The analysis found all four annulus samples to be composed mainly of Si, Na, and Al and lesser amounts of other elements. The XRD data indicate quartz (SiO{sub 2}) and sodium aluminum nitrate silicate hydrate (Na{sub 8}(Al{sub 6}Si{sub 6}O{sub 24})(NO{sub 3}){sub 2}.4H{sub 2}O) as the predominant crystalline mineral phases in the samples. The XRD data also indicate the presence of crystalline sodium nitratemore » (NaNO{sub 3}), sodium nitrite (NaNO{sub 2}), gibbsite (Al(OH){sub 3}), hydrated sodium bicarbonate (Na{sub 3}H(CO{sub 3}){sub 2}.2H{sub 2}O), and muscovite (KAl{sub 2}(AlSi{sub 3}O{sub 10})(OH){sub 2}). Based on the weight of solids remaining at the end of the test, the water leaching test results indicate 20-35% of the solids dissolved after three contacts with an approximately 3:1 volume of water at 45 C. The chemical analysis of the leachates and the XRD results of the remaining solids indicate sodium salts of nitrate, nitrite, sulfate, and possibly carbonate/bicarbonate make up the majority of the dissolved material. The majority of these salts were dissolved in the first water contact and simply diluted with each subsequent water contact. The water leaching removed large amounts of the uranium in two of the samples and approximately 1/3 of the {sup 99}Tc from all four samples. Most of the other radionuclides analyzed showed low solubility in the water leaching test. The oxalic acid leaching test result indicate approximately 34-47% of the solids in the four annulus samples will dissolve after three contacts with an approximately 3:1 volume of acid to solids at 45 C. The same sodium salts found in the water leaching test comprise the majority of dissolved material in the oxalic acid leaching test. However, the oxalic acid was somewhat more effective in dissolving radionuclides than the water leach. In contrast to the water leaching results, most constituents continued to dissolve during subsequent cycles of oxalic acid leaching. The somewhat higher dissolution found in the oxalic acid leaching test versus the water leaching test might be offset by the tendency of the oxalic acid solutions to take on a gel-like consistency. The filtered solids left behind after three oxalic acid contacts were sticky and formed large clumps after drying. These two observations could indicate potential processing difficulties with solutions and solids from oxalic acid leaching. The gel formation might be avoided by using larger volumes of the acid. Further testing would be recommended before using oxalic acid to dissolve the Tank 16H annulus waste to ensure no processing difficulties are encountered in the full scale process.« less

PROCESS OF PURIFYING URANIUM

DOEpatents

Seaborg, G.T.; Orlemann, E.F.; Jensen, L.H.

1958-12-23

A method of obtaining substantially pure uranium from a uranium composition contaminated with light element impurities such as sodium, magnesium, beryllium, and the like is described. An acidic aqueous solution containing tetravalent uranium is treated with a soluble molybdate to form insoluble uranous molybdate which is removed. This material after washing is dissolved in concentrated nitric acid to obtaln a uranyl nitrate solution from which highly purified uranium is obtained by extraction with ether.

Removing Al and regenerating caustic soda from the spent washing liquor of Al etching

NASA Astrophysics Data System (ADS)

Barakat, M. A.; El-Sheikh, S. M.; Farghly, F. E.

2005-08-01

Spent liquor from washing of aluminum section materials after etching with caustic soda (NaOH) has been treated. Aluminum was removed from the liquor and caustic soda was regenerated by adding precipitating agents to hydrolyze sodium aluminate (Na2AlO2), separating the aluminumprecipitate, and concentrating free NaOH in the resulting solution for reuse in the etching process. Four systems were investigated: hydrated lime [Ca(OH)2], hydrogen peroxide (H2O2), H2O2/Ca(OH)2 mixture, and dry lime (CaO). Results revealed that CaO was more efficient in the removal of aluminum from the spent liquor with a higher hydrolyzing rate of Na2AlO2 than Ca(OH)2, H2O2, or their mixture.

Method for removing elemental sulfur in sour gas wells

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

Sample, T.E. Jr.

1975-09-30

A process is described for removing sulfur deposits from sour gas wells. The formation, well, and surface equipment are contacted with a chemical composition whose aqueous solution will solubilize the sulfur by primary chemical reaction and contains a wetting agent to facilitate and accelerate the sulfur dissolution and removal. The wetting agent or surfactant may be any of a wide variety of surface-active substances such as soaps, sodium or ammonium salts of alkyl or alkyl-aryl sulfates and sulfonates. Nonionic surfactants are preferred, such as ethoxylated substituted phenols. The aqueous solvents are capable of chemically reacting with sulfur to form water-solublemore » sulfur derivatives and include aqueous solutions of alkalies, bases (both inorganic and organic), ammonia, sulfites, bisulfites, etc. (6 claims)« less

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

Shekiro, III, Joseph; Chen, Xiaowen; Smith, Holly

Dilute-acid pretreatment has proven to be a robust means of converting herbaceous feedstock to fermentable sugars. However, it also releases acetic acid, a known fermentation inhibitor, from acetyl groups present in the biomass. A mild, dilute alkaline extraction stage was implemented prior to acid pretreatment to separate acetic acid from the hydrolysate sugar stream. This step, termed deacetylation, improved the glucose and xylose yields from enzymatic hydrolysis and ethanol yields from fermentation of the sugars relative to the control experiments using dilute-acid pretreatment of native corn stover without deacetylation. While promising, deacetylation as it was historically practiced is conducted atmore » low solids loadings, and at fixed conditions. Thus, many questions have been left unanswered, including the relationship between sodium hydroxide and solids loading, and acetate and xylan solubilization, as well as the impact of temperature and residence time on the process efficacy. A central composite experiment was designed to evaluate the impact of solids loading, sodium hydroxide loading, reaction time and temperature during deacetylation on the acetate and xylan solubilization of corn stover. Using the ANOVA test, it became apparent that neither of the responses was significantly impacted by the solids loading, while the reaction time was a minor factor - the responses were largely driven by reaction temperature and the sodium hydroxide loading. Based on the results, we successfully demonstrated the ability to transition the low-solids (10 % w/w) deacetylation process to a higher-solids process (30 % w/w) with minimal impact on the ability to extract acetate from biomass. Conditions were selected to minimize xylose loss during deacetylation, while also removing 70 % of acetyl groups. The impact of selected conditions on the enzymatic hydrolysis and fermentation was further investigated. In conclusion, evaluation of the whole-process impact demonstrated that despite the upfront reduction in carbohydrate loss during deacetylation, the overall process sugar yields were depressed by the high-solids, low alkali process relative to the historical control. Consequently, ethanol titers were reduced, though strong fermentation performance was still observed, indicating that 70 % acetate removal is sufficient to depress acetic acid concentrations to a level that does not substantially inhibit ethanol fermentation by rZymomo nas.« less

Demonstration and Validation of a Regenerated Cellulose Dialysis Membrane Diffusion Sampler for Monitoring Groundwater Quality and Remediation Progress at DoD Sites

DTIC Science & Technology

2007-02-01

years if kept refrigerated in its preservative solution of ethanol, sodium benzoate , and ethylene diamine tetra-acetic acid (EDTA). Alternatively... sodium bicarbonate solution, EDTA, and sodium azide solution to remove residual gylcerol, sulfide, cadmium, chromium, copper, iron, nickel, zinc, and lead...Magnesium Cadmium Nickel Potassium Chromium Selenium Sodium Copper Vanadium Aluminum Iron Zinc Arsenic Lead Antimony Manganese Anions (1-3 days

Separating and stabilizing phosphate from high-level radioactive waste: process development and spectroscopic monitoring.

PubMed

Lumetta, Gregg J; Braley, Jenifer C; Peterson, James M; Bryan, Samuel A; Levitskaia, Tatiana G

2012-06-05

Removing phosphate from alkaline high-level waste sludges at the Department of Energy's Hanford Site in Washington State is necessary to increase the waste loading in the borosilicate glass waste form that will be used to immobilize the highly radioactive fraction of these wastes. We are developing a process which first leaches phosphate from the high-level waste solids with aqueous sodium hydroxide, and then isolates the phosphate by precipitation with calcium oxide. Tests with actual tank waste confirmed that this process is an effective method of phosphate removal from the sludge and offers an additional option for managing the phosphorus in the Hanford tank waste solids. The presence of vibrationally active species, such as nitrate and phosphate ions, in the tank waste processing streams makes the phosphate removal process an ideal candidate for monitoring by Raman or infrared spectroscopic means. As a proof-of-principle demonstration, Raman and Fourier transform infrared (FTIR) spectra were acquired for all phases during a test of the process with actual tank waste. Quantitative determination of phosphate, nitrate, and sulfate in the liquid phases was achieved by Raman spectroscopy, demonstrating the applicability of Raman spectroscopy for the monitoring of these species in the tank waste process streams.

Migration and distribution of sodium ions and organic matters during electro-dewatering of waste activated sludge at different dosages of sodium sulfate.

PubMed

Xiao, Jun; Wu, Xu; Yu, Wenbo; Liang, Sha; Yu, Jiangwei; Gu, Yueyuan; Deng, Huali; Hu, Jiukun; Xiao, Keke; Yang, Jiakuan

2017-12-01

In this study, the influence of Na 2 SO 4 on electro-dewatering (EDW) of waste activated sludge (WAS) was investigated. The highest water removal efficiency of 42.5% was achieved at the optimum Na 2 SO 4 dosage of 12.5 g kg -1 DS during EDW process at a constant voltage of 20 V. The migration and distribution of water, organic matters and Na + at different Na 2 SO 4 dosages were investigated through layered experiments. The results indicated the entire EDW process followed the S curve model, and it can be divided into three stages: (1) initial desalination stage: at the initial few min of EDW process, the rate of electroosmosis was extremely slow while electromigration of ions like Na + was intense, and the electromigration was more obvious with increased Na 2 SO 4 dosage; (2) dewatering stage: the dewatering efficiency increased dramatically via electroosmosis; (3) the dewaterability limit stage: the maximum value of dewatering efficiency has been achieved, while the water removal efficiency and dry solids content remained constant. During the EDW process, the possible electrolysis resulted in a pH gradient in the sludge cake. With the addition of Na 2 SO 4 in the EDW, the pH gradient was intensified, and the migration rate of organic matters moving from cathode to anode increased while compared with the raw WAS. This study provided insights into the mechanism of EDW process at different dosages of Na 2 SO 4 . Copyright © 2017 Elsevier Ltd. All rights reserved.

Flue gas desulfurization

DOEpatents

Im, K.H.; Ahluwalia, R.K.

1984-05-01

The invention involves a combustion process in which combustion gas containing sulfur oxide is directed past a series of heat exchangers to a stack and in which a sodium compound is added to the combustion gas in a temparature zone of above about 1400 K to form Na/sub 2/SO/sub 4/. Preferably, the temperature is above about 1800 K and the sodium compound is present as a vapor to provide a gas-gas reaction to form Na/sub 2/SO/sub 4/ as a liquid. Since liquid Na/sub 2/SO/sub 4/ may cause fouling of heat exchanger surfaces downstream from the combustion zone, the process advantageously includes the step of injecting a cooling gas downstream of the injection of the sodium compound yet upstream of one or more heat exchangers to cool the combustion gas to below about 1150 K and form solid Na/sub 2/SO/sub 4/. The cooling gas is preferably a portion of the combustion gas downstream which may be recycled for cooling. It is further advantageous to utilize an electrostatic precipitator downstream of the heat exchangers to recover the Na/sub 2/SO/sub 4/. It is also advantageous in the process to remove a portion of the combustion gas cleaned in the electrostatic precipitator and recycle that portion upstream to use as the cooling gas. 3 figures.

Effect of the cathode material on the removal of nitrates by electrolysis in non-chloride media.

PubMed

Lacasa, Engracia; Cañizares, Pablo; Llanos, Javier; Rodrigo, Manuel A

2012-04-30

In this work, the effect of the cathode material (conductive diamond, stainless steel, silicon carbide, graphite or lead) and the current density (150-1400 A m(-2)) on the removal of nitrates from aqueous solutions is studied by electrolysis in non-divided electrochemical cells equipped with conductive diamond anodes, using sodium sulphate as the electrolyte. The results show that the cathode material very strongly influences both the process performance and the product distribution. The main products obtained are gaseous nitrogen (NO, N(2)O and NO(2)) and ammonium ions. Nitrate removal follows first order kinetics, which indicates that the electrolysis process is controlled by mass transfer. Furthermore, the stainless steel and graphite cathodes show a great selectivity towards the production of ammonium ions, whereas the silicon carbide cathode leads to the highest formation of gaseous nitrogen, which production is promoted at low current densities. Copyright © 2012 Elsevier B.V. All rights reserved.

Combined electrochemical, sunlight-induced oxidation and biological process for the treatment of chloride containing textile effluent.

PubMed

Santhanam, Manikandan; Selvaraj, Rajeswari; Annamalai, Sivasankar; Sundaram, Maruthamuthu

2017-11-01

This study presents a combined electrochemical, sunlight-induced oxidation and biological process for the treatment of textile effluent. In the first step, RuO 2 -TiO 2 /Ti and Titanium were used as the electrodes in EO process and color removal was achieved in 40 min at an applied current density of 20 mA cm -2 . The EO process generated about 250 mg L -1 of active chlorine which hampered the subsequent biological treatment process. Thus, in the second step, sun light-induced photolysis (SLIP) is explored to remove hypochlorite present in the EO treated effluent. In the third step, the SLIP treated effluent was fed to laccase positive bacterial consortium for biological process. To assess the effect of SLIP in the overall process, experiments were carried out with and without SLIP process. In experiments without SLIP, sodium thiosulfate was used to remove active chlorine. HPLC analysis showed that SLIP integrated experiments achieved an overall dye component degradation of 71%, where as only 22% degradation was achieved in the absence of SLIP process. The improvement in degradation with SLIP process is attributed to the presence of ClO radicals which detected by EPR analysis. The oxidation of organic molecules during process was confirmed by FT-IR and GC-MS analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Efficiency of a cleaning protocol for the removal of enterotoxigenic Staphylococcus aureus strains in dairy plants.

PubMed

Martin, José Guilherme Prado; de Oliveira E Silva, Gabriela; da Fonseca, Carolina Rodrigues; Morales, Caio Baptista; Souza Pamplona Silva, Caroline; Miquelluti, Daniel Lima; Porto, Ernani

2016-12-05

Staphylococci are considered a major concern in dairy plants mainly due to the intensive production flow, automation of processing plants and increased demand in the microbiological quality of dairy products. This study aimed to identify S. aureus strains isolated from three Brazilian dairy plants, evaluate the influence of time, temperature and contact surface on the bacterial adhesion process, as well as the efficiency of simulated hygiene and sanitation protocol in removing adhered cells. For genotypic analyses, the presence of icaA and icaD in strains was evaluated. Adherence assays were performed in biofilm reactor, comparing the influence of 2 temperatures (5°C and 35°C), 2 surfaces (stainless steel and polypropylene) and 4 contact times (3, 6, 12h and post-sanitization). To evaluate the process effectiveness in removing adhered cells, neutral detergent and sanitizing agent based on sodium hypochlorite were used in order to simulate the situation observed in one of the dairy plants analyzed. The presence of icaA and icaD genes was determined in 75.3% and 77.6% of strains, respectively; 70.6% of isolates showed both genes, whereas 17.6% showed no genes. Genes for enterotoxin production were found in all samples, relating to SEG and SEH toxins. The number of cells adhered on both surfaces was about 3 and 6 log 10 CFU/cm 2 at temperatures of 5°C and 35°C, respectively, for most situations evaluated, with significant increase over the evaluation period. In general, the temperature of 35°C favored greater adherence of S. aureus. At 5°C, there was a considerable number of adhered cells, but in populations significantly lower than those observed at 35°C. The cleaning and sanitizing protocol was ineffective in removing adhered cells; better performance of sodium hypochlorite was observed at 5°C, which should be related to lower adherence observed at this temperature. Thus, the process was not able to reduce the number of S. aureus bacteria adhered on both surfaces to safe levels under the conditions evaluated. Copyright © 2016 Elsevier B.V. All rights reserved.

9 CFR 96.13 - Uncertified casings; disinfection with hydrochloric acid.

Code of Federal Regulations, 2014 CFR

2014-01-01

... solution, rinse them with water, and place them in a solution containing 81/2 pounds of sodium bicarbonate... from the sodium bicarbonate solution and wash them to remove the excess of bicarbonate. (Approved by...

9 CFR 96.13 - Uncertified casings; disinfection with hydrochloric acid.

Code of Federal Regulations, 2013 CFR

2013-01-01

... solution, rinse them with water, and place them in a solution containing 81/2 pounds of sodium bicarbonate... from the sodium bicarbonate solution and wash them to remove the excess of bicarbonate. (Approved by...

9 CFR 96.13 - Uncertified casings; disinfection with hydrochloric acid.

Code of Federal Regulations, 2012 CFR

2012-01-01

... solution, rinse them with water, and place them in a solution containing 81/2 pounds of sodium bicarbonate... from the sodium bicarbonate solution and wash them to remove the excess of bicarbonate. (Approved by...

9 CFR 96.13 - Uncertified casings; disinfection with hydrochloric acid.

Code of Federal Regulations, 2011 CFR

2011-01-01

... solution, rinse them with water, and place them in a solution containing 81/2 pounds of sodium bicarbonate... from the sodium bicarbonate solution and wash them to remove the excess of bicarbonate. (Approved by...

Efficacy of passive ultrasonic irrigation with natural irrigants (Morinda citrifolia juice, Aloe Vera and Propolis) in comparison with 1% sodium hypochlorite for removal of E. faecalis biofilm: an in vitro study.

PubMed

Bhardwaj, Anuj; Velmurugan, Natanasabapathy; Ballal, Suma

2013-01-01

Present study evaluated the efficacy of natural derivative irrigants, Morinda citrifolia juice (MCJ), Aloe Vera and Propolis in comparison to 1% sodium hypochlorite with passive ultrasonic irrigation for removal of the intraradicular E. faecalis biofilms in extracted single rooted human permanent teeth. Biofilms of E. faecalis were grown on the prepared root canal walls of 60 standardized root halves which were longitudinally sectioned. These root halves were re-approximated and the samples were divided into five groups of twelve each. The groups were, Group A (1% NaOCl), Group B (MCJ), Group C (Aloe vera), Group D (Propolis) and Group E (Saline). These groups were treated with passive ultrasonic irrigation (PUI) along with the respective irrigants. The root halves were processed for scanning electron microscopy. Three images (X2.5), coronal, middle and apical, were taken for the twelve root halves in each of the five groups. The images were randomized and biofilm coverage assessed independently by three calibrated examiners, using a four-point scoring system. 1% NaOCl with passive ultrasonic irrigation (PUI) was effective in completely removing E. faecalis biofilm and was superior to the natural irrigants like MCJ, Aloe vera and Propolis tested in this study. 1% NaOCl used along with passive ultrasonic irrigation was effective in completely removing E. faecalis biofilm when compared to natural irrigants (MCJ, Aloe Vera and Propolis).

Microwave-assisted activated carbon from cocoa shell as adsorbent for removal of sodium diclofenac and nimesulide from aqueous effluents.

PubMed

Saucier, Caroline; Adebayo, Matthew A; Lima, Eder C; Cataluña, Renato; Thue, Pascal S; Prola, Lizie D T; Puchana-Rosero, M J; Machado, Fernando M; Pavan, Flavio A; Dotto, G L

2015-05-30

Microwave-induced chemical activation process was used to prepare an activated carbon from cocoa shell for efficient removal of two anti-inflammatories, sodium diclofenac (DFC) and nimesulide (NM), from aqueous solutions. A paste was obtained from a mixture of cocoa shell and inorganic components; with a ratio of inorganic: organic of 1 (CSC-1.0). The mixture was pyrolyzed in a microwave oven in less than 10 min. The CSC-1.0 was acidified with a 6 mol L(-1) HCl under reflux to produce MWCS-1.0. The CSC-1.0 and MWCS-1.0 were characterized using FTIR, SEM, N2 adsorption/desorption curves, X-ray diffraction, and point of zero charge (pHpzc). Experimental variables such as initial pH of the adsorbate solutions and contact time were optimized for adsorptive characteristics of MWCS-1.0. The optimum pH for removal of anti-inflammatories ranged between 7.0 and 8.0. The kinetic of adsorption was investigated using general order, pseudo first-order and pseu do-second order kinetic models. The maximum amounts of DCF and NM adsorbed onto MWCS-1.0 at 25 °C are 63.47 and 74.81 mg g(-1), respectively. The adsorbent was tested on two simulated hospital effluents. MWCS-1.0 is capable of efficient removal of DCF and NM from a medium that contains high sugar and salt concentrations. Copyright © 2015 Elsevier B.V. All rights reserved.

Role of Bladder Hydrodistention and Intravesical Sodium Hyaluronate in the Treatment of Interstitial Cystitis.

PubMed

Yang, Jin-Yi; Wei, Wei; Lan, Yu-Long; Liu, Jun-Qiang; Wang, Hai-Bo; Li, Shao

2015-12-23

To evaluate the clinical efficacy of bladder hydrodistention and intravesical sodium hyaluronate in the treatment of interstitial cystitis (IC). Twenty-one patients with IC received intravesical sodium hyaluronate therapy under nerve block or intravenous anesthesia. Bladders were perfused with 100 cmH2O perfusion pressure and expanded for 10 min and were later injected with 40 mg/50 mL sodium hyaluronate through the catheter. After 1 h, the perfusion fluid was released. Perfusion was applied once per week, 4 to 6 times as a course of treatment. Under anesthesia, the average bladder capacity was 191.62 ± 88.67 mL, and after bladder expansion, the bladder capacity reached 425.33 ± 79.83 mL (P = .000). There were 2 suspected bladder ruptures after bladder expansion at 6.5 min and 7.2 min. After 10 min of bladder expansion, there were 19 cases of significantly gross hematuria. After treatment, the catheters of 17 patients were removed at 24 h; for the 2 cases of hematuria, catheters were removed at 72 h and for the 2 cases of suspected bladder rupture, catheters were removed after 4 days. After catheter removal, the pain threshold significantly decreased, and the maximum urinary output increased slightly. Compared with values before treatment, the day before the second injection of sodium hyaluronate, the frequency of urination decreased significantly (32.8 vs. 18.5 times/24 h), the maximum urinary output increased significantly (86.7 vs. 151.9 mL), the pain decreased significantly (8.7 vs. 3.0), and the O'Leary-Sant IC score and quality of life score were significantly decreased (30.0 vs. 17.0 and 5.9 vs. 2.4, respectively) (P = .000). Bladder hydrodistention under anesthesia for patients with severe intractable IC produces immediate effectiveness; sodium hyaluronic infusion can alleviate frequent urination and pain, and the efficacy was positively correlated with the duration of treatment.

Degradation and removal of Ceftriaxone sodium in aquatic environment with Bi2WO6/g-C3N4 photocatalyst.

PubMed

Zhao, Yanyan; Liang, Xuhua; Wang, Yongbo; Shi, Huanxian; Liu, Enzhou; Fan, Jun; Hu, Xiaoyun

2018-08-01

Modern chemistry aims to identify outstanding photocatalytic materials for antibiotic degradation given the overuse and misuse of antibiotics. Herein, highly efficient heterojunction photocatalysts composed of Bi 2 WO 6 nanoflowers (BW) and g-C 3 N 4 nanosheets (CNNs) were successfully synthesized. The Bi 2 WO 6 /g-C 3 N 4 (BW/CNNs) were presented for Ceftriaxone sodium degradation in the aquatic environment at low concentrations under visible light irradiation. The 40%-BW/CNNs showed excellent photocatalytic activity, and approximately 94.50% Ceftriaxone sodium was degraded under visible lightirradiation for 120 min. h + and O 2 - played major roles compared with ·OH in the photocatalytic process. The degradation mechanism and the intermediate products were proposed to better understand the reaction process. Moreover, the as-prepared photocatalysts were highly stable in recycling photocatalytic experiments. Therefore, the photocatalysts prepared in the study showed outstanding photocatalytic activity and potential applications in inhibiting environmental pollution. In addition, this work provides a new insight for constructing other high-performance, low-cost photocatalysts for wastewater treatment. Copyright © 2018 Elsevier Inc. All rights reserved.

Thermodynamic criteria for the removal of impurities from end-of-life magnesium alloys by evaporation and flux treatment

NASA Astrophysics Data System (ADS)

Hiraki, Takehito; Takeda, Osamu; Nakajima, Kenichi; Matsubae, Kazuyo; Nakamura, Shinichiro; Nagasaka, Tetsuya

2011-06-01

In this paper, the possibility of removing impurities during magnesium recycling with pyrometallurgical techniques has been evaluated by using a thermodynamic analysis. For 25 different elements that are likely to be contained in industrial magnesium alloys, the equilibrium distribution ratios between the metal, slag and gas phases in the magnesium remelting process were calculated assuming binary systems of magnesium and an impurity element. It was found that calcium, gadolinium, lithium, ytterbium and yttrium can be removed from the remelted end-of-life (EoL) magnesium products by oxidization. Calcium, cerium, gadolinium, lanthanum, lithium, plutonium, sodium, strontium and yttrium can be removed by chlorination with a salt flux. However, the other elements contained in magnesium alloy scrap are scarcely removed and this may contribute toward future contamination problems. The third technological option for the recycling of EoL magnesium products is magnesium recovery by a distillation process. Based on thermodynamic considerations, it is predicted that high-purity magnesium can be recovered through distillation because of its high vapor pressure, yet there is a limit on recoverability that depends on the equilibrium vapor pressure of the alloying elements and the large energy consumption. Therefore, the sustainable recycling of EoL magnesium products should be an important consideration in the design of advanced magnesium alloys or the development of new refining processes.

Thermodynamic criteria for the removal of impurities from end-of-life magnesium alloys by evaporation and flux treatment

PubMed Central

Hiraki, Takehito; Takeda, Osamu; Nakajima, Kenichi; Matsubae, Kazuyo; Nakamura, Shinichiro; Nagasaka, Tetsuya

2011-01-01

In this paper, the possibility of removing impurities during magnesium recycling with pyrometallurgical techniques has been evaluated by using a thermodynamic analysis. For 25 different elements that are likely to be contained in industrial magnesium alloys, the equilibrium distribution ratios between the metal, slag and gas phases in the magnesium remelting process were calculated assuming binary systems of magnesium and an impurity element. It was found that calcium, gadolinium, lithium, ytterbium and yttrium can be removed from the remelted end-of-life (EoL) magnesium products by oxidization. Calcium, cerium, gadolinium, lanthanum, lithium, plutonium, sodium, strontium and yttrium can be removed by chlorination with a salt flux. However, the other elements contained in magnesium alloy scrap are scarcely removed and this may contribute toward future contamination problems. The third technological option for the recycling of EoL magnesium products is magnesium recovery by a distillation process. Based on thermodynamic considerations, it is predicted that high-purity magnesium can be recovered through distillation because of its high vapor pressure, yet there is a limit on recoverability that depends on the equilibrium vapor pressure of the alloying elements and the large energy consumption. Therefore, the sustainable recycling of EoL magnesium products should be an important consideration in the design of advanced magnesium alloys or the development of new refining processes. PMID:27877407

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

SAMS TL; GUILLOT S

Scoping laboratory scale tests were performed at the Chemical Engineering Department of the Georgia Institute of Technology (Georgia Tech), and the Hanford 222-S Laboratory, involving double-shell tank (DST) and single-shell tank (SST) Hanford waste simulants. These tests established the viability of the Lithium Hydrotalcite precipitation process as a solution to remove aluminum and recycle sodium hydroxide from the Hanford tank waste, and set the basis of a validation test campaign to demonstrate a Technology Readiness Level of 3.

Aqueous Dispersions of Silica Stabilized with Oleic Acid Obtained by Green Chemistry.

PubMed

Nistor, Cristina Lavinia; Ianchis, Raluca; Ghiurea, Marius; Nicolae, Cristian-Andi; Spataru, Catalin-Ilie; Culita, Daniela Cristina; Pandele Cusu, Jeanina; Fruth, Victor; Oancea, Florin; Donescu, Dan

2016-01-05

The present study describes for the first time the synthesis of silica nanoparticles starting from sodium silicate and oleic acid (OLA). The interactions between OLA and sodium silicate require an optimal OLA/OLANa molar ratio able to generate vesicles that can stabilize silica particles obtained by the sol-gel process of sodium silicate. The optimal molar ratio of OLA/OLANa can be ensured by a proper selection of OLA and respectively of sodium silicate concentration. The titration of sodium silicate with OLA revealed a stabilization phenomenon of silica/OLA vesicles and the dependence between their average size and reagent's molar ratio. Dynamic light scattering (DLS) and scanning electron microscopy (SEM) measurements emphasized the successful synthesis of silica nanoparticles starting from renewable materials, in mild condition of green chemistry. By grafting octadecyltrimethoxysilane on the initial silica particles, an increased interaction between silica particles and the OLA/OLANa complex was achieved. This interaction between the oleyl and octadecyl chains resulted in the formation of stable gel-like aqueous systems. Subsequently, olive oil and an oleophylic red dye were solubilized in these stable aqueous systems. This great dispersing capacity of oleosoluble compounds opens new perspectives for future green chemistry applications. After the removal of water and of the organic chains by thermal treatment, mesoporous silica was obtained.

Effect of different irrigation on smear layer removal after post space preparation.

PubMed

Gu, Xin-Hua; Mao, Cai-Yun; Kern, Matthias

2009-04-01

The purpose of this study was to evaluate the effect of different irrigating solutions on smear layer removal and dentinal tubule opening on root canal surfaces after post space preparation and to study whether additional ultrasonic irrigation has any effect on smear layer removal. Forty-eight anterior teeth were treated endodontically. After post space preparation, they were assigned to six groups: group 1, EDTA; group 2, EDTA with ultrasonic activation; group 3, sodium hypochlorite (NaOCl); group 4, NaOCl with ultrasonic activation; group 5, sodium chloride (NaCl); and group 6, NaCl with ultrasonic activation. Specimens were examined under a field-emission scanning electron microscope and scored for debris removal and dentinal tubule opening at the coronal, middle, and apical thirds of the root canal. The results showed that EDTA performed significantly better than NaCl and NaOCl in smear layer removal and dentinal tubule opening. Additional ultrasonic irrigation did not improve smear layer removal significantly.

PROCESS USING BISMUTH PHOSPHATE AS A CARRIER PRECIPITATE FOR FISSION PRODUCTS AND PLUTONIUM VALUES

DOEpatents

Finzel, T.G.

1959-03-10

A process is described for separating plutonium from fission products carried therewith when plutonium in the reduced oxidation state is removed from a nitric acid solution of irradiated uranium by means of bismuth phosphate as a carrier precipitate. The bismuth phosphate carrier precipitate is dissolved by treatment with nitric acid and the plutonium therein is oxidized to the hexavalent oxidation state by means of potassium dichromate. Separation of the plutonium from the fission products is accomplished by again precipitating bismuth phosphate and removing the precipitate which now carries the fission products and a small percentage of the plutonium present. The amount of plutonium carried in this last step may be minimized by addition of sodium fluoride, so as to make the solution 0.03N in NaF, prior to the oxidation and prccipitation step.

Lessons learned in acquiring new regulations for shipping advanced electric vehicle batteries

NASA Astrophysics Data System (ADS)

Henriksen, Gary; Hammel, Carol; Altemos, Edward A.

1994-12-01

In 1990, the Electric and Hybrid Propulsion Division of the US Department of Energy established its ad hoc EV Battery Readiness Working Group to identify regulatory barriers to the commercialization of advanced EV battery technologies and facilitate the removal of these barriers. A Shipping Sub-Working Group (SSWG) was formed to address the regulatory issues associated with the domestic and international shipment of these new battery technologies. The SSWG invites major industrial developers of advanced battery technologies to join as members and work closely with appropriate domestic and international regulatory authorities to develop suitable regulations and procedures for the safe transport of these new battery technologies. This paper describes the domestic and international regulatory processes for the transport of dangerous goods; reviews the status of shipping regulations for sodium-beta and lithium batteries; and delineates the lessons learned to date in this process. The sodium-beta battery family was the first category of advanced EV batteries to be addressed by the SSWG. It includes both sodium/sulfur and sodium/metal chloride batteries. Their efforts led to the establishment of a UN number (UN 3292) in the UN Recommendations, for cold cells and batteries, and establishment of a US Department of Transportation general exemption (DOT-E-10917) covering cold and hot batteries, as well as cold cells. The lessons learned for sodium-beta batteries, over the period of 1990--94, are now being applied to the development of regulations for shipping a new generation of lithium battery technologies (lithium-polymer and lithium-aluminum/iron sulfide batteries).

UV/TiO₂ photocatalytic oxidation of recalcitrant organic matter: effect of salinity and pH.

PubMed

Muthukumaran, Shobha; Song, Lili; Zhu, Bo; Myat, Darli; Chen, Jin-Yuan; Gray, Stephen; Duke, Mikel

2014-01-01

Photocatalytic oxidation processes have interest for water treatment since these processes can remove recalcitrant organic compounds and operate at mild conditions of temperature and pressure. However, performance under saline conditions present in many water resources is not well known. This study aims to explore the basic effects of photocatalysis on the removal of organic matter in the presence of salt. A laboratory-scale photocatalytic reactor system, employing ultraviolet (UV)/titanium dioxide (TiO₂) photocatalysis was evaluated for its ability to remove the humic acid (HA) from saline water. The particle size and zeta potential of TiO₂ under different conditions including solution pH and sodium chloride (NaCl) concentrations were characterized. The overall degradation of organics over the NaCl concentration range of 500-2,000 mg/L was found to be 80% of the non-saline equivalent after 180 min of the treatment. The results demonstrated that the adsorption of HA onto the TiO₂ particles was dependent on both the pH and salinity due to electrostatic interaction and highly unstable agglomerated dispersion. This result supports UV/TiO₂ as a viable means to remove organic compounds, but the presence of salt in waters to be treated will influence the performance of the photocatalytic oxidation process.

Processing Plan for Potentially Reactive/Ignitable Remote Handled Transuranic Waste at the Idaho Cleanup Project - 12090

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

Troescher, Patrick D.; Hobbes, Tammy L.; Anderson, Scott A.

Remote Handle Transuranic (RH-TRU) Waste generated at Argonne National Laboratory - East, from the examination of irradiated and un-irradiated fuel pins and other reactor materials requires a detailed processing plan to ensure reactive/ignitable material is absent to meet WIPP Waste Acceptance Criteria prior to shipping and disposal. The Idaho Cleanup Project (ICP) approach to repackaging Lot 2 waste and how we ensure prohibited materials are not present in waste intended for disposal at Waste Isolation Pilot Plant 'WIPP' uses an Argon Repackaging Station (ARS), which provides an inert gas blanket. Opening of the Lot 2 containers under an argon gasmore » blanket is proposed to be completed in the ARS. The ARS is an interim transition repackaging station that provides a mitigation technique to reduce the chances of a reoccurrence of a thermal event prior to rendering the waste 'Safe'. The consequences, should another thermal event be encountered, (which is likely) is to package the waste, apply the reactive and or ignitable codes to the container, and store until the future treatment permit and process are available. This is the same disposition that the two earlier containers in the 'Thermal Events' were assigned. By performing the initial handling under an inert gas blanket, the waste can sorted and segregate the fines and add the Met-L-X to minimize risk before it is exposed to air. The 1-gal cans that are inside the ANL-E canister will be removed and each can is moved to the ARS for repackaging. In the ARS, the 1-gal can is opened in the inerted environment. The contained waste is sorted, weighed, and visually examined for non compliant items such as unvented aerosol cans and liquids. The contents of the paint cans are transferred into a sieve and manipulated to allow the fines, if any, to be separated into the tray below. The fines are weighed and then blended with a minimum 5:1 mix of Met-L-X. Other debris materials found are segregated from the cans into containers for later packaging. Recoverable fissile waste material (Fuel and fuel-like pieces) suspected of containing sodium bonded pieces) are segregated and will remain in the sieve or transferred to a similar immersion basket in the ARS. The fuel like pieces will be placed into a container with sufficient water to cover the recoverable fissile waste. If a 'reactive characteristic' is present the operator will be able to observe the formation of 'violent' hydrogen gas bubbles. When sodium bonded fuel-like pieces are placed in water the expected reaction is a non-violent reaction that does not meet the definition of reactivity. It is expected that there will be a visible small stream of bubbles present if there is any sodium-bonded fuel-like piece placed in the water. The test will be completed when there is no reaction or the expected reaction is observed..At that point, the fuel like pieces complete the processing cycle in preparation for characterization and shipment to WIPP. If a violent reaction occurs, the fuel-like pieces will be removed from the water, split into the required fissile material content, placed into a screened basket in a 1 gallon drum and drummed out of the hot cell with appropriate RCRA codes applied and placed into storage until sodium treatment is available. These 'violent' reactions will be evidenced by gas bubbles being evolved at the specimen surface where sodium metal is present. The operators will be trained to determine if the reaction is 'violent' or 'mild'. If a 'violent' reaction occurs, the sieve will be immediately removed from the water, placed in a 1 gallon paint can, canned in the argon cover gas and removed from the hot cell to await a future treatment. If the reaction is 'mild', the sieve will then be removed from the water; the material weighed for final packaging and allowed to dry by air exposure. Lot 2 waste cans can be opened, sorted, processed, and weighed while mitigating the potential of thermal events that could occur prior to exposing to air. Exposure to air is a WIPP compliance step demonstrating the absence of reactive or ignitable characteristics. (authors)« less

Reactivity of clay minerals with acids and alkalies

USGS Publications Warehouse

Carroll, Dorothy; Starkey, Harry C.

1971-01-01

One-g samples of a montmorillonite, a metabentonite, an illite, two kaolinites, and three halloysites were treated with 50 ml of hydrochloric acid (6⋅45 N, 1:1), acetic acid (4⋅5 N, 1:3), sodium hydroxide (2⋅8 N), sodium chloride solution (pH 6⋅10; Na = 35‰; Cl = 21⋅5‰), and natural sea water (pH 7⋅85; Na = 35⋅5‰; Cl = 21⋅ 5‰) for a 10-day period in stoppered plastic vials. The supernatant solutions were removed from the clay minerals and analyzed for SiO2, Al2O3, CaO, MgO, Na2O, and K2O. All the solutions removed some SiO2, Al2O3, and Fe2O3 from the samples, but the quantities were small. Sodium hydroxide attacked the kaolin group minerals more strongly than it did montmorillonite, metabentonite, or illite. Halloysite was more strongly attacked by hydrochloric acid than was any of the other experimental minerals. Hydrochloric acid removed iron oxide coatings from soil clay minerals, but acetic acid did not remove them completely. The samples most strongly attacked by HCl and NaOH were examined by X-ray diffraction. Acid treatment did not destroy the structure of the clays, but the halloysite structure was partially destroyed. Sodium hydroxide attacked the halloysite structure, as shown by chemical analysis and X-ray diffraction. These experiments show that treatment in dilute acids has no harmful effect in the preparation of clays for X-ray diffraction. Acetic acid is preferred to hydrochloric acid for this purpose. Hydrochloric acid cleans clay minerals by removing free iron oxide from the surface; acetic acid is less effective.

Low-Sodium Versus Standard-Sodium Peritoneal Dialysis Solution in Hypertensive Patients: A Randomized Controlled Trial.

PubMed

Rutkowski, Bolesław; Tam, Paul; van der Sande, Frank M; Vychytil, Andreas; Schwenger, Vedat; Himmele, Rainer; Gauly, Adelheid

2016-05-01

Peritoneal dialysis (PD) solutions with reduced sodium content may have advantages for hypertensive patients; however, they have lower osmolarity and solvent drag, so the achieved Kt/Vurea may be lower. Furthermore, the increased transperitoneal membrane sodium gradient can influence sodium balance with consequences for blood pressure (BP) control. Prospective, randomized, double-blind clinical trial to prove the noninferiority of total weekly Kt/Vurea with low-sodium versus standard-sodium PD solution, with the lower confidence limit above the clinically accepted difference of -0.5. Hypertensive patients (≥ 1 antihypertensive drug, including diuretics, or office systolic BP ≥ 130 mmHg) on continuous ambulatory PD therapy from 17 sites. 108 patients were randomly assigned (1:1) to 6-month treatments with either low-sodium (125 mmol/L of sodium; 1.5%, 2.3%, or 4.25% glucose; osmolarity, 338-491 mOsm/L) or standard-sodium (134 mmol/L of sodium; 1.5%, 2.3%, or 4.25% glucose; osmolarity, 356-509 mOsm/L) PD solution. Primary end point: weekly total Kt/Vurea; secondary outcomes: BP control, safety, and tolerability. Total Kt/Vurea was determined from 24-hour dialysate and urine collection; BP, by office measurement. Total Kt/Vurea after 12 weeks was 2.53 ± 0.89 in the low-sodium group (n = 40) and 2.97 ± 1.58 in the control group (n = 42). The noninferiority of total Kt/Vurea could not be confirmed. There was no difference for peritoneal Kt/Vurea (1.70 ± 0.38 with low sodium, 1.77 ± 0.44 with standard sodium), but there was a difference in renal Kt/Vurea (0.83 ± 0.80 with low sodium, 1.20 ± 1.54 with standard sodium). Mean daily sodium removal with dialysate at week 12 was 1.188 g higher in the low-sodium group (P < 0.001). BP changed marginally with standard-sodium solution, but decreased with low-sodium PD solution, resulting in less antihypertensive medication. Broader variability of study population than anticipated, particularly regarding residual kidney function. The noninferiority of the low-sodium PD solution for total Kt/Vurea could not be proved; however, it showed beneficial clinical effects on sodium removal and BP. Copyright © 2016 Fresenius Medical Care. Published by Elsevier Inc. All rights reserved.

Effective removal of hazardous trace metals from recovery boiler fly ashes.

PubMed

Kinnarinen, Teemu; Golmaei, Mohammad; Jernström, Eeva; Häkkinen, Antti

2018-02-15

The objective of this study is to introduce a treatment sequence enabling straightforward and effective recovery of hazardous trace elements from recovery boiler fly ash (RBFA) by a novel method, and to demonstrate the subsequent removal of Cl and K with the existing crystallization technology. The treatment sequence comprises two stages: dissolution of most other RBFA components than the hazardous trace elements in water in Step 1 of the treatment, and crystallization of the process chemicals in Step 2. Solid-liquid separation has an important role in the treatment, due to the need to separate first the small solid residue containing the trace elements, and to separate the valuable crystals, containing Na and S, from the liquid rich in Cl and K. According to the results, nearly complete recovery of cadmium, lead and zinc can be reached even without pH adjustment. Some other metals, such as Mg and Mn, are removed together with the hazardous metals. Regarding the removal of Cl and K from the process, in this non-optimized case the removal efficiency was satisfactory: 60-70% for K when 80% of sodium was recovered, and close to 70% for Cl when 80% of sulfate was recovered. Copyright © 2017 Elsevier B.V. All rights reserved.

DEVELOPMENT OF NONCARBON SORBENTS FOR HG0 REMOVAL FROM COAL-FIRED POWER PLANTS

EPA Science Inventory

Noncarbon materials or mineral oxides (silica gel, alumina, molecular sieves, zeolites, and montmorillonite) were modified with various functional groups, such as amine, amide, thiol, and urea; and active additives, such as elemental sulfur, sodium sulfide, and sodium polysulfide...

LITERATURE REVIEWS TO SUPPORT ION EXCHANGE TECHNOLOGY SELECTION FOR MODULAR SALT PROCESSING

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

King, W

2007-11-30

This report summarizes the results of literature reviews conducted to support the selection of a cesium removal technology for application in a small column ion exchange (SCIX) unit supported within a high level waste tank. SCIX is being considered as a technology for the treatment of radioactive salt solutions in order to accelerate closure of waste tanks at the Savannah River Site (SRS) as part of the Modular Salt Processing (MSP) technology development program. Two ion exchange materials, spherical Resorcinol-Formaldehyde (RF) and engineered Crystalline Silicotitanate (CST), are being considered for use within the SCIX unit. Both ion exchange materials havemore » been studied extensively and are known to have high affinities for cesium ions in caustic tank waste supernates. RF is an elutable organic resin and CST is a non-elutable inorganic material. Waste treatment processes developed for the two technologies will differ with regard to solutions processed, secondary waste streams generated, optimum column size, and waste throughput. Pertinent references, anticipated processing sequences for utilization in waste treatment, gaps in the available data, and technical comparisons will be provided for the two ion exchange materials to assist in technology selection for SCIX. The engineered, granular form of CST (UOP IE-911) was the baseline ion exchange material used for the initial development and design of the SRS SCIX process (McCabe, 2005). To date, in-tank SCIX has not been implemented for treatment of radioactive waste solutions at SRS. Since initial development and consideration of SCIX for SRS waste treatment an alternative technology has been developed as part of the River Protection Project Waste Treatment Plant (RPP-WTP) Research and Technology program (Thorson, 2006). Spherical RF resin is the baseline media for cesium removal in the RPP-WTP, which was designed for the treatment of radioactive waste supernates and is currently under construction in Hanford, WA. Application of RF for cesium removal in the Hanford WTP does not involve in-riser columns but does utilize the resin in large scale column configurations in a waste treatment facility. The basic conceptual design for SCIX involves the dissolution of saltcake in SRS Tanks 1-3 to give approximately 6 M sodium solutions and the treatment of these solutions for cesium removal using one or two columns supported within a high level waste tank. Prior to ion exchange treatment, the solutions will be filtered for removal of entrained solids. In addition to Tanks 1-3, solutions in two other tanks (37 and 41) will require treatment for cesium removal in the SCIX unit. The previous SCIX design (McCabe, 2005) utilized CST for cesium removal with downflow supernate processing and included a CST grinder following cesium loading. Grinding of CST was necessary to make the cesium-loaded material suitable for vitrification in the SRS Defense Waste Processing Facility (DWPF). Because RF resin is elutable (and reusable) and processing requires conversion between sodium and hydrogen forms using caustic and acidic solutions more liquid processing steps are involved. The WTP baseline process involves a series of caustic and acidic solutions (downflow processing) with water washes between pH transitions across neutral. In addition, due to resin swelling during conversion from hydrogen to sodium form an upflow caustic regeneration step is required. Presumably, one of these basic processes (or some variation) will be utilized for MSP for the appropriate ion exchange technology selected. CST processing involves two primary waste products: loaded CST and decontaminated salt solution (DSS). RF processing involves three primary waste products: spent RF resin, DSS, and acidic cesium eluate, although the resin is reusable and typically does not require replacement until completion of multiple treatment cycles. CST processing requires grinding of the ion exchange media, handling of solids with high cesium loading, and handling of liquid wash and conditioning solutions. RF processing requires handling and evaporation of cesium eluates, disposal of spent organic resin, and handling of the various liquid wash and regenerate solutions used. In both cases, the DSS will be immobilized in a low activity waste form. It appears that both technologies are mature, well studied, and generally suitable for this application. Technology selection will likely be based on downstream impacts or preferences between the various processing options for the two materials rather than on some unacceptable performance property identified for one material. As a result, the following detailed technical review and summary of the two technologies should be useful to assist in technology selection for SCIX.« less

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

Edwin S. Olson; Kurt E. Eylands; Daniel J. Stepan

New federal drinking water regulations have been promulgated to restrict the levels of disinfection by-products (DBPs) in finished public water supplies. DBPs are suspected carcinogens and are formed when organic material is partially oxidized by disinfectants commonly used in the water treatment industry. Additional federal mandates are expected in the near future that will also affect public water suppliers with respect to DBPs. These new federal drinking water regulations may require public water suppliers to adjust treatment practices or incorporate additional treatment operations into their existing treatment trains. Many options have been identified, including membrane processes, granular activated carbon, poweredmore » activated carbon (PAC), enhanced coagulation and/or softening, and alternative disinfectants (e.g., chlorine dioxide, ozone, and chloramines). Of the processes being considered, PAC appears to offer an attractive benefit-to-cost advantage for many water treatment plants, particularly small systems (those serving fewer than 10,000 customers). PAC has traditionally been used by the water treatment industry for the removal of compounds contributing to taste and odor problems. PAC also has the potential to remove naturally occurring organic matter (NOM) from raw waters prior to disinfection, thus controlling the formation of regulated DBPs. Many small water systems are currently using PAC for taste and odor control and have the potential to use PAC for controlling DBPs. Activated carbons can be produced from a variety of raw materials, including wood, peat, coconut husks, and numerous types of coal. The Energy & Environmental Research Center (EERC) has been working on the development of a PAC product to remove NOM from surface water supplies to prevent the formation of carcinogenic DBPs during chlorination. During that study, the sodium and calcium content of the lignites showed a significant effect on the sorption capacity of the activated carbon product. As much as a 130% increase in the humic acid sorption capacity of a PAC produced from a high-sodium-content lignite was observed. We hypothesize that the sodium and calcium content of the coal plays a significant role in the development of pore structures and pore-size distribution, ultimately producing activated carbon products that have greater sorption capacity for specific contaminants, depending on molecular size.« less

Decontamination of soil washing wastewater using solar driven advanced oxidation processes.

PubMed

Bandala, Erick R; Velasco, Yuridia; Torres, Luis G

2008-12-30

Decontamination of soil washing wastewater was performed using two different solar driven advanced oxidation processes (AOPs): the photo-Fenton reaction and the cobalt/peroxymonosulfate/ultraviolet (Co/PMS/UV) process. Complete sodium dodecyl sulphate (SDS), the surfactant agent used to enhance soil washing process, degradation was achieved when the Co/PMS/UV process was used. In the case of photo-Fenton reaction, almost complete SDS degradation was achieved after the use of almost four times the actual energy amount required by the Co/PMS/UV process. Initial reaction rate in the first 15min (IR15) was determined for each process in order to compare them. Highest IR15 value was determined for the Co/PMS/UV process (0.011mmol/min) followed by the photo-Fenton reaction (0.0072mmol/min) and the dark Co/PMS and Fenton processes (IR15=0.002mmol/min in both cases). Organic matter depletion in the wastewater, as the sum of surfactant and total petroleum hydrocarbons present (measured as chemical oxygen demand, COD), was also determined for both solar driven processes. It was found that, for the case of COD, the highest removal (69%) was achieved when photo-Fenton reaction was used whereas Co/PMS/UV process yielded a slightly lower removal (51%). In both cases, organic matter removal achieved was over 50%, which can be consider proper for the coupling of the tested AOPs with conventional wastewater treatment processes such as biodegradation.

Removal of sodium inactivation and block of sodium channels by chloramine-T in crayfish and squid giant axons.

PubMed Central

Huang, J. M.; Tanguy, J.; Yeh, J. Z.

1987-01-01

Modification of sodium channels by chloramine-T was examined in voltage clamped internally perfused crayfish and squid giant axons using the double sucrose gap and axial wire technique, respectively. Freshly prepared chloramine-T solution exerted two major actions on sodium channels: (a) an irreversible removal of the fast Na inactivation, and (b) a reversible block of the Na current. Both effects were observed when chloramine-T was applied internally or externally (5-10 mM) to axons. The first effect was studied in crayfish axons. We found that the removal of the fast Na inactivation did not depend on the states of the channel since the channel could be modified by chloramine-T at holding potential (from -80 to -100 mV) or at depolarized potential of -30 mV. After removal of fast Na inactivation, the slow inactivation mechanism was still present, and more channels could undergo slow inactivation. This result indicates that in crayfish axons the transition through the fast inactivated state is not a prerequisite for the slow inactivation to occur. During chloramine-T treatment, a distinct blocking phase occurred, which recovered upon washing out the drug. This second effect of chloramine-T was studied in detail in squid axons. After 24 h, chloramine-T solution lost its ability to remove fast inactivation but retained its blocking action. After removal of the fast Na inactivation, both fresh and aged chloramine-T solutions blocked the Na currents with a similar potency and in a voltage-dependent manner, being more pronounced at lower depolarizing potentials. A similar voltage-dependent block was observed with aged chloramine-T solution in an axon with intact inactivation. In contrast to the action of the fresh solution, the aged chloramine-T solution was found to accelerate the decay of Na currents.These results suggest that chloramine-T solution contains at least two active molecular forms that act at different sites in the Na channel. PMID:2444276

Lactate rescues neuronal sodium homeostasis during impaired energy metabolism.

PubMed

Karus, Claudia; Ziemens, Daniel; Rose, Christine R

2015-01-01

Recently, we established that recurrent activity evokes network sodium oscillations in neurons and astrocytes in hippocampal tissue slices. Interestingly, metabolic integrity of astrocytes was essential for the neurons' capacity to maintain low sodium and to recover from sodium loads, indicating an intimate metabolic coupling between the 2 cell types. Here, we studied if lactate can support neuronal sodium homeostasis during impaired energy metabolism by analyzing whether glucose removal, pharmacological inhibition of glycolysis and/or addition of lactate affect cellular sodium regulation. Furthermore, we studied the effect of lactate on sodium regulation during recurrent network activity and upon inhibition of the glial Krebs cycle by sodium-fluoroacetate. Our results indicate that lactate is preferentially used by neurons. They demonstrate that lactate supports neuronal sodium homeostasis and rescues the effects of glial poisoning by sodium-fluoroacetate. Altogether, they are in line with the proposed transfer of lactate from astrocytes to neurons, the so-called astrocyte-neuron-lactate shuttle.

Lactate rescues neuronal sodium homeostasis during impaired energy metabolism

PubMed Central

Karus, Claudia; Ziemens, Daniel; Rose, Christine R

2015-01-01

Recently, we established that recurrent activity evokes network sodium oscillations in neurons and astrocytes in hippocampal tissue slices. Interestingly, metabolic integrity of astrocytes was essential for the neurons' capacity to maintain low sodium and to recover from sodium loads, indicating an intimate metabolic coupling between the 2 cell types. Here, we studied if lactate can support neuronal sodium homeostasis during impaired energy metabolism by analyzing whether glucose removal, pharmacological inhibition of glycolysis and/or addition of lactate affect cellular sodium regulation. Furthermore, we studied the effect of lactate on sodium regulation during recurrent network activity and upon inhibition of the glial Krebs cycle by sodium-fluoroacetate. Our results indicate that lactate is preferentially used by neurons. They demonstrate that lactate supports neuronal sodium homeostasis and rescues the effects of glial poisoning by sodium-fluoroacetate. Altogether, they are in line with the proposed transfer of lactate from astrocytes to neurons, the so-called astrocyte-neuron-lactate shuttle. PMID:26039160

Study of the factors influencing the metals solubilisation from a mixture of waste batteries by response surface methodology.

PubMed

Tanong, Kulchaya; Coudert, Lucie; Chartier, Myriam; Mercier, Guy; Blais, Jean-François

2017-12-01

This paper presents an innovative process for the recovery of valuable metals from a mixture of spent batteries. Different types of batteries, including alkaline, zinc-carbon (Zn-C), nickel cadmium (Ni-Cd), nickel metal hydride (Ni-MH), lithium ion (Li-ion) and lithium metallic (Li-M) batteries, were mixed according to the proportion of the Canadian sales of batteries. A Box-Behnken design was applied to find the optimum leaching conditions allowing a maximum of valuable metal removals from a mixture of spent batteries in the presence of an inorganic acid and a reducing agent. The results highlighted the positive effect of sodium metabisulfite on the performance of metals removal, especially for Mn. The solid/liquid ratio and the concentration of H 2 SO 4 were the main factors affecting the leaching behavior of valuable metals (Zn, Mn, Cd, Ni) present in spent batteries. Finally, the optimum leaching conditions were found as follows: one leaching step, solid/liquid ratio = 10.9%, [H 2 SO 4 ] = 1.34 M, sodium metabisulfite (Na 2 S 2 O 5 ) = 0.45 g/g of battery powder and retention time = 45 min. Under such conditions, the removal yields achieved were 94% for Mn, 81% for Cd, 99% for Zn, 96% for Co and 68% for Ni.

Removal of indicator organisms by chemical treatment of wastewater.

PubMed

De Zutter, L; van Hoof, J

1981-01-01

Recently a new chemical wastewater treatment process based upon precipitation of proteins by sodium lignosulphonate under acid conditions is used to purify the wastewater from slaughterhouses and poultry processing plants. In order to determine the reduction of indicator organisms due to this treatment process, influent and effluent samples from two of such plants (plant A in a pig slaughterhouse and plant B in a poultry processing plant) were examined. The results demonstrated that the pH used in the process, has a considerable influence on the reduction of the indicator organisms. On the first sampling day in plant A the initial working-pH was 4 and the corresponding reduction of the different microorganisms varied from 0.7 to 1.5 log. According to the decrease of the pH to 2.3, the reduction increased to a minimum of at least 1.9 and a maximum of at least 4.5 log. In the other samples from this plant (working-pH 2.4) the elimination ranged from 1.8 to 4.0 log. In plant B, the removal of the indicator organisms brought about by a working-pH of 3.0 ranged from 2.1 to 3.1 log. The results showed that in comparison with the biological treatment processes this chemical wastewater treatment process realized a significant greater removal of indicator organisms.

Investigation of the Effectiveness of Polymers in the Treatment of Nitrocellulose-Manufacturing Wastewater

DTIC Science & Technology

1976-03-01

Nonionic polyacryl - aaide was the most effective for the purification and up to 80% removal of pulp fiber was obtained In a wide range of pH tested...Anionic polyolectrolyte. such as 3odium alginate and sodium polyacrylate , however, dispersed the suspension of pulp fiber instead of coagulating it. The...This process is called filter conditioning. They have observed that the continuous application of a polyacryl - amide solution (5-50 ppb) improved the

Start-up of simultaneous removal of ammonium and sulfate from an anaerobic ammonium oxidation (anammox) process in an anaerobic up-flow bioreactor.

PubMed

Yang, Zhiquan; Zhou, Shaoqi; Sun, Yanbo

2009-09-30

A laboratory testing of simultaneous removal of ammonium and sulfate (SRAS) was studied from an anammox process in an anaerobic bioreactor filled with granular activated carbon. Two different phases of experiment were investigated to start up the SRAS process, and final batch tests were performed to analyze the SRAS process. The experiment included an anammox process and an SRAS process. During the anammox process, the highest removal efficiency of ammonium and nitrite was up to 97 and 98%, respectively. After 160 days in the stationary phase of anammox process, the ratio of ammonium to nitrite consumption was approximately 1:1.15, which is much higher than 1:1.32 in the traditional anammox process. The extra electron acceptor, such as sulfate, was thought to react with ammonium by bacteria. Synthetic wastewater containing ammonium chlorine and sodium sulfate was used as the feed for the bioreactor in the second phase of experiment. During the SRAS process, the influent concentrations of ammonium and sulfate were controlled to be 50-60 and 210-240 mg L(-1) respectively. After start-up and acclimatization of this process for 60 days, the average effluent concentrations of ammonium and sulfate were 30 and 160 mg L(-1), respectively. The simultaneous ammonium and sulfate removal was detected in the reactor. In order to further validate the biochemical interaction between ammonium and sulfate, batch tests was carried out. Abiotic tests were carried out to demonstrate that the pure chemical action between ammonium and sulfate without microorganism was not possible. Biotic assays with different ammonium and sulfate concentrations were further investigated that high concentrations of ammonium and sulfate could promote simultaneous removal of ammonium and sulfate. And elemental sulfur and nitrogen gas as the products measured in the SRAS process helped to demonstrate the occurrence of new interaction between nitrogen and sulfur. The new process of SRAS in the inorganic condition, including simultaneous removal of ammonium and sulfate, and the appearance of elemental sulfur and nitrogen gas as the terminal products, widened the cycle approach between nitrogen and sulfur.

Bidentate organophosphorus solvent extraction process for actinide recovery and partition

DOEpatents

Schulz, Wallace W.

1976-01-01

A liquid-liquid extraction process for the recovery and partitioning of actinide values from acidic nuclear waste aqueous solutions, the actinide values including trivalent, tetravalent and hexavalent oxidation states is provided and includes the steps of contacting the aqueous solution with a bidentate organophosphorous extractant to extract essentially all of the actinide values into the organic phase. Thereafter the respective actinide fractions are selectively partitioned into separate aqueous solutions by contact with dilute nitric or nitric-hydrofluoric acid solutions. The hexavalent uranium is finally removed from the organic phase by contact with a dilute sodium carbonate solution.

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

Not Available

The NOXSO Process uses a regenerable sorbent that removes SO{sub 2} and NO{sub x} simultaneously from flue gas. The sorbent is a stabilized {gamma}-alumina bed impregnated with sodium carbonate. The process was successfully tested at three different scales, equivalent to 0.017, 0.06 and 0.75 MW of flue gas generated from a coal-fired power plant. The Proof-of-Concept (POC) Test is the last test prior to a full-scale demonstration. A slip stream of flue gas equivalent to a 5 MW coal-fired power plant was used for the POC test. This paper summarizes the NOXSO POC plant and its test results.

Pretreatment of Hanford medium-curie wastes by fractional crystallization.

PubMed

Nassif, Laurent; Dumont, George; Alysouri, Hatem; Rousseau, Ronald W

2008-07-01

Acceleration of the schedule for decontamination of the Hanford site using bulk vitrification requires implementation of a pretreatment operation. Medium-curie waste must be separated into two fractions: one is to go to a waste treatment and immobilization plant and a second, which is low-activity waste, is to be processed by bulk vitrification. The work described here reports research on using fractional crystallization for that pretreatment. Sodium salts are crystallized by evaporation of water from solutions simulating those removed from single-shell tanks, while leaving cesium in solution. The crystalline products are then recovered and qualified as low-activity waste, which is suitable upon redissolution for processing by bulk vitrification. The experimental program used semibatch operation in which a feed solution was continuously added to maintain a constant level in the crystallizer while evaporating water. The slurry recovered at the end of a run was filtered to recover product crystals, which were then analyzed to determine their composition. The results demonstrated that targets on cesium separation from the solids, fractional recovery of sodium salts, and sulfate content of the recovered salts can be achieved by the process tested.

Passive air cooling of liquid metal-cooled reactor with double vessel leak accommodation capability

DOEpatents

Hunsbedt, A.; Boardman, C.E.

1995-04-11

A passive and inherent shutdown heat removal method with a backup air flow path which allows decay heat removal following a postulated double vessel leak event in a liquid metal-cooled nuclear reactor is disclosed. The improved reactor design incorporates the following features: (1) isolation capability of the reactor cavity environment in the event that simultaneous leaks develop in both the reactor and containment vessels; (2) a reactor silo liner tank which insulates the concrete silo from the leaked sodium, thereby preserving the silo`s structural integrity; and (3) a second, independent air cooling flow path via tubes submerged in the leaked sodium which will maintain shutdown heat removal after the normal flow path has been isolated. 5 figures.

Passive air cooling of liquid metal-cooled reactor with double vessel leak accommodation capability

DOEpatents

Hunsbedt, Anstein; Boardman, Charles E.

1995-01-01

A passive and inherent shutdown heat removal method with a backup air flow path which allows decay heat removal following a postulated double vessel leak event in a liquid metal-cooled nuclear reactor. The improved reactor design incorporates the following features: (1) isolation capability of the reactor cavity environment in the event that simultaneous leaks develop in both the reactor and containment vessels; (2) a reactor silo liner tank which insulates the concrete silo from the leaked sodium, thereby preserving the silo's structural integrity; and (3) a second, independent air cooling flow path via tubes submerged in the leaked sodium which will maintain shutdown heat removal after the normal flow path has been isolated.

Effect of Aquatine Endodontic Cleanser on smear layer removal in the root canals of ex vivo human teeth.

PubMed

Garcia, Faustino; Murray, Peter E; Garcia-Godoy, Franklin; Namerow, Kenneth N

2010-01-01

The purpose of this study was to measure and compare the root canal cleanliness and smear layer removal effectiveness of Aquatine Endodontic Cleanser (Aquatine EC) when used as an endodontic irrigating solution in comparison with 6% sodium hypochlorite (NaOCl). Forty-five human teeth were randomly allocated to five treatment groups; the pulp chamber was accessed, cleaned, and shaped by using ProTaper and ProFile rotary instrumentation to an ISO size #40. The teeth were then processed for scanning electron microscopy, and the root canal cleanliness and removal of smear layer were examined. The most effective removal of smear layer occurred with Aquatine EC and NaOCl, both with a rinse of EDTA. Aquatine EC appears to be the first hypochlorous acid approved by the FDA to be a possible alternative to the use of NaOCl as an intracanal irrigant. Further research is needed to identify safer and more effective alternatives to the use of NaOCl irrigation in endodontics.

Oil removal of spent hydrotreating catalyst CoMo/Al2O3 via a facile method with enhanced metal recovery.

PubMed

Yang, Yue; Xu, Shengming; Li, Zhen; Wang, Jianlong; Zhao, Zhongwei; Xu, Zhenghe

2016-11-15

Deoiling process is a key issue for recovering metal values from spent hydrotreating catalysts. The oils can be removed with organic solvents, but the industrialized application of this method is greatly hampered by the high cost and complex processes. Despite the roasting method is simple and low-cost, it generates hardest-to-recycle impurities (CoMoO4 or NiMoO4) and enormous toxic gases. In this study, a novel and facile approach to remove oils from the spent hydrotreating catalysts is developed. Firstly, surface properties of spent catalysts are characterized to reveal the possibility of oil removal. And then, oils are removed with water solution under the conditions of 90°C, 0.1wt% SDS, 2.0wt% NaOH and 10ml/gL/S ratio for 4h. Finally, thermal treatment and leaching tests are carried out to further explore the advantages of oil removal. The results show that no hardest-to-recycle impurity CoMoO4 is found in XPS spectra of thermally treated samples after deoiling and molybdenum is leached completely with sodium carbonate solution. It means that the proposed deoiling method can not only remove oils simply and without enormous harmful gases generating, but also avoid the generation of detrimental impurity and promote recycling of valuable metals from spent hydrotreating catalysts. Copyright © 2016 Elsevier B.V. All rights reserved.

Treatment of vinasse from tequila production using polyglutamic acid.

PubMed

Carvajal-Zarrabal, Octavio; Nolasco-Hipólito, Cirilo; Barradas-Dermitz, Dulce Ma; Hayward-Jones, Patricia M; Aguilar-Uscanga, Ma Guadalupe; Bujang, Kopli

2012-03-01

Vinasse, the wastewater from ethanol distillation, is characterised by high levels of organic and inorganic matter, high exit process temperature (ca. 90°C) and low pH (3.0-4.5). In this study, the treatment of tequila vinasse was achieved by a flocculation-coagulation process using poly-γ-glutamic acid (PGA). Results showed that the use of PGA (250-300 ppm) combined with sodium hypochlorite and sand filtration managed to remove about 70% of the turbidity and reduced chemical oxygen demand (COD) by 79.5% with the extra benefit of colour removal. PGA showed its best flocculating activity at pH 2.5-3.5 and a temperature of 30-55°C. Such a treatment may be a solution for small tequila companies for which other solutions to deal with their vinasse may not be economically affordable. Copyright © 2011 Elsevier Ltd. All rights reserved.

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

Russell, Renee L.; Fiskum, Sandra K.; Smoot, Margaret R.

Washington River Protection Solutions (WRPS) is developing a Low-Activity Waste Pretreatment System (LAWPS) to provide low-activity waste (LAW) directly to the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Low-Activity Waste Facility for immobilization. The pretreatment that will be conducted on tank waste supernate at the LAWPS facility entails filtration to remove entrained solids and cesium (Cs) ion exchange to remove Cs from the product sent to the WTP. Currently, spherical resorcinol-formaldehyde (sRF) resin (Microbeads AS, Skedsmokorset, Norway) is the Cs ion exchange resin of choice. Most work on Cs ion exchange efficacy in Hanford tank waste has been conductedmore » at nominally 5 M sodium (Na). WRPS is examining the possibility of processing supernatant at high Na concentrations—up to 8 M Na—to maximize processing efficiency through the LAWPS. Minimal Cs ion exchange work has been conducted at 6 M and 8 M Na concentrations..« less

Properties of an intermediate-duration inactivation process of the voltage-gated sodium conductance in rat hippocampal CA1 neurons.

PubMed

French, Christopher R; Zeng, Zhen; Williams, David A; Hill-Yardin, Elisa L; O'Brien, Terence J

2016-02-01

Rapid transmembrane flow of sodium ions produces the depolarizing phase of action potentials (APs) in most excitable tissue through voltage-gated sodium channels (NaV). Macroscopic currents display rapid activation followed by fast inactivation (IF) within milliseconds. Slow inactivation (IS) has been subsequently observed in several preparations including neuronal tissues. IS serves important physiological functions, but the kinetic properties are incompletely characterized, especially the operative timescales. Here we present evidence for an "intermediate inactivation" (II) process in rat hippocampal CA1 neurons with time constants of the order of 100 ms. The half-inactivation potentials (V0.5) of steady-state inactivation curves were hyperpolarized by increasing conditioning pulse duration from 50 to 500 ms and could be described by a sum of Boltzmann relations. II state transitions were observed after opening as well as subthreshold potentials. Entry into II after opening was relatively insensitive to membrane potential, and recovery of II became more rapid at hyperpolarized potentials. Removal of fast inactivation with cytoplasmic papaine revealed time constants of INa decay corresponding to II and IS with long depolarizations. Dynamic clamp revealed attenuation of trains of APs over the 10(2)-ms timescale, suggesting a functional role of II in repetitive firing accommodation. These experimental findings could be reproduced with a five-state Markov model. It is likely that II affects important aspects of hippocampal neuron response and may provide a drug target for sodium channel modulation. Copyright © 2016 the American Physiological Society.

Sodium hypochlorite (dilute chlorine bleach) oral rinse in patient self-care.

PubMed

Rich, Sandra K; Slots, Jørgen

2015-01-01

Sodium hypochlorite (NaOCl), commonly known as "bleach," is widely accepted as being a safe and effective antiseptic against bacteria, fungi, and viruses. For over a century, bleach has been used to control or overcome infection in homes, hospitals, and even on battlefields, and in endodontics for disinfection of root canals. This paper reviews clinical studies on the efficacy of sodium hypochlorite oral rinse to combat dental plaque and gingival inflammation. Sodium hypochlorite is readily available as inexpensive household bleach, and we suggest that oral rinsing twice weekly with dilute bleach (0.25% sodium hypochlorite) constitutes a valuable adjunct to current methods of plaque removal.

Micellar casein concentrate production with a 3X, 3-stage, uniform transmembrane pressure ceramic membrane process at 50°C.

PubMed

Hurt, E; Zulewska, J; Newbold, M; Barbano, D M

2010-12-01

The production of serum protein (SP) and micellar casein from skim milk can be accomplished using microfiltration (MF). Potential commercial applications exist for both SP and micellar casein. Our research objective was to determine the total SP removal and SP removal for each stage, and the composition of retentates and permeates, for a 3×, continuous bleed-and-feed, 3-stage, uniform transmembrane pressure (UTP) system with 0.1-μm ceramic membranes, when processing pasteurized skim milk at 50°C with 2 stages of water diafiltration. For each of 4 replicates, about 1,100 kg of skim milk was pasteurized (72°C, 16s) and processed at 3× through the UTP MF system. Retentate from stage 1 was cooled to <4°C and stored until the next processing day, when it was diluted with reverse osmosis water back to a 1× concentration and again processed through the MF system (stage 2) to a 3× concentration. The retentate from stage 2 was stored at <4°C, and, on the next processing day, was diluted with reverse osmosis water back to a 1× concentration, before running through the MF system at 3× for a total of 3 stages. The retentate and permeate from each stage were analyzed for total nitrogen, noncasein nitrogen, and nonprotein nitrogen using Kjeldahl methods; sodium dodecyl sulfate-PAGE analysis was also performed on the retentates from each stage. Theoretically, a 3-stage, 3× MF process could remove 97% of the SP from skim milk, with a cumulative SP removal of 68 and 90% after the first and second stages, respectively. The cumulative SP removal using a 3-stage, 3× MF process with a UTP system with 0.01-μm ceramic membranes in this experiment was 64.8 ± 0.8, 87.8 ± 1.6, and 98.3 ± 2.3% for the first, second, and third stages, respectively, when calculated using the mass of SP removed in the permeate of each stage. Various methods of calculation of SP removal were evaluated. Given the analytical limitations in the various methods for measuring SP removal, calculation of SP removal based on the mass of SP in the skim milk (determined by Kjeldahl) and the mass SP present in all of the permeate produced by the process (determined by Kjeldahl) provided the best estimate of SP removal for an MF process. Copyright © 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Zero Liquid Discharge (ZLD) System for Flue-Gas Derived Water From Oxy-Combustion Process

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

Sivaram Harendra; Danylo Oryshchyn; Thomas Ochs

2011-10-16

Researchers at the National Energy Technology Laboratory (NETL) located in Albany, Oregon, have patented a process - Integrated Pollutant Removal (IPR) that uses off-the-shelf technology to produce a sequestration ready CO{sub 2} stream from an oxy-combustion power plant. Capturing CO{sub 2} from fossil-fuel combustion generates a significant water product which can be tapped for use in the power plant and its peripherals. Water condensed in the IPR{reg_sign} process may contain fly ash particles, sodium (from pH control), and sulfur species, as well as heavy metals, cations and anions. NETL is developing a treatment approach for zero liquid discharge while maximizingmore » available heat from IPR. Current treatment-process steps being studied are flocculation/coagulation, for removal of cations and fine particles, and reverse osmosis, for anion removal as well as for scavenging the remaining cations. After reverse osmosis process steps, thermal evaporation and crystallization steps will be carried out in order to build the whole zero liquid discharge (ZLD) system for flue-gas condensed wastewater. Gypsum is the major product from crystallization process. Fast, in-line treatment of water for re-use in IPR seems to be one practical step for minimizing water treatment requirements for CO{sub 2} capture. The results obtained from above experiments are being used to build water treatment models.« less

Removal of heavy metals from waste streams

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

Spence, M.D.; Kozaruk, J.M.; Melvin, M.

1988-07-19

A method for removing heavy metals from effluent water is described comprising performing sequentially the following steps: (a) adding from 7-333 ppm of an anionic surfactant to the effluent water to provide coagulatable heavy metal ion; (b) adjusting the effluent water pH to within the range of 8 to 10, (c) providing from 10-200 ppm of a cationic coagulant to coagulate the heavy metal ion, (d) providing from 0.3 to 5.0 ppm of a polymeric flocculant whereby a heavy metal containing floc is formed for removal from the effluent water, and, (e) then removing the floc from the effluent water,more » wherein the anionic surfactant is sodium lauryl ether sulfate. The cationic coagulant is selected from the group consisting of diallyl dimethylammonium chloride polymer, epichlorohydrin dimethylamine polymer, ethylene amine polymer, polyaluminum chloride, and alum; and the flocculant is an acrylamide/sodium acrylate copolymer having an RSV greater than 23.« less

Hair decontamination procedure prior to multi-class pesticide analysis.

PubMed

Duca, Radu-Corneliu; Hardy, Emilie; Salquèbre, Guillaume; Appenzeller, Brice M R

2014-06-01

Although increasing interest is being observed in hair analysis for the biomonitoring of human exposure to pesticides, some limitations still have to be addressed for optimum use of this matrix in that specific context. One main possible issue concerns the need to differentiate chemicals biologically incorporated into hair from those externally deposited on hair surface from contaminated air or dust. The present study focuses on the development of a washing procedure for the decontamination of hair before analysis of pesticides from different chemical classes. For this purpose, three different procedures of artificial contamination (with silica, cellulose, and aqueous solution) were used to simulate pesticides deposition on hair surface. Several washing solvents (four organic: acetone, dichloromethane, methanol, acetonitrile; and four aqueous: water, phosphate buffer, shampoo, sodium dodecylsulfate) were evaluated for their capacity to remove artificially deposited pesticides from hair surface. The most effective washing solvents were sodium dodecylsulfate and methanol for aqueous and organic solvents, respectively. Moreover, after a first washing with sodium dodecylsulfate or methanol, the majority of externally deposited pesticides was removed and a steady-state was reached since significantly lower amounts were removed by additional second and third washings. Finally, the effectiveness of a decontamination procedure comprising washing with sodium dodecylsulfate and methanol was successively demonstrated. In parallel, it was determined that the final procedure did not affect the chemicals biologically incorporated, as hair strands naturally containing pesticides were used. Such a procedure appears to remove in one-shot the fraction of chemicals located on hair surface and does not require repeated washing steps. Copyright © 2014 John Wiley & Sons, Ltd.

Comparative stain removal properties of four commercially available denture cleaning products: an in vitro study.

PubMed

Alam, M; Jagger, R; Vowles, R; Moran, J

2011-02-01

Formulations of commercially available denture cleaners vary widely. Unfortunately, comparative data to suggest which products are the most effective can become invalid as newer products are introduced or formulations are changed. The aim of this in vitro study was to measure the stain removal properties of four currently available denture cleaners. Stain was deposited on multi-well polystyrene saliva coated microplates using multiple chlorhexidine and tea solutions. Following drying, each stained well was exposed to a solution of denture cleaner, dried again and the amount of stain remaining measured using a microplate reader. The cleaning procedure was repeated with further multiple exposures of the wells to solutions of the denture cleaners. All denture cleaners removed stain better than water used as a control. At five cleaning cycles only one of the cleaners (Superdrug Cleaning Powder) had removed 100% of the stain. At 30 cycles three of the cleaners had removed 100% of the stain. All the commercial denture cleaners removed stain. Superdrug Cleaning Powder, which contains sodium percarbonate and sodium lauryl sulphate, was particularly effective. © 2010 John Wiley & Sons A/S.

Removal of Cu(II) in water by polymer enhanced ultrafiltration: Influence of polymer nature and pH.

PubMed

Kochkodan, Olga D; Kochkodan, Viktor M; Sharma, Virender K

2018-01-02

This study presents an efficient removal of Cu(II) in water using the polymer enhanced ultrafiltration (PEUF) method. Polymer of different molecular weight (MW) (polyethyleneimine (PEI), sodium lignosulfonates (SLS) and dextrans) were investigated to evaluate efficiency in removal of Cu(II) in water by the PEUF method. The decomposition of Cu(II)-polymer complex was also evaluated in order to reuse polymers. Cu(II) complexation depends on the MW of chelating polymer and the pH of feed solution. It was found that the Cu(II) rejection increased with the polymer dosage with high removal of Cu(II) when using PEI and SLS at a 10:20 (mg/mg) ratio ([Cu(II)]:[polymer]). It was found that the maximum chelating capacity was 15 mg of Cu(II) per 20 mg of PEI. The Cu(II)-PEI complex could be decomposed by acid addition and the polymer could be efficiently reused with multiple complexation-decomplexation cycles. A conceptual flow chart of the integrated process of efficient removal of Cu(II) by PEUF method is suggested.

Color removal from distillery spent wash through coagulation using Moringa oleifera seeds: use of optimum response surface methodology.

PubMed

Prasad, R Krishna

2009-06-15

The effects of dosage, pH and concentration of salts were investigated for an optimized condition of color removal from the distillery spent wash. The optimization process was analyzed using custom response surface methodology (RSM). The design was employed to derive a statistical model for the effect of parameters studied on removal of color using Moringa oleifera coagulant (MOC). The dosage (20 and 60 ml), pH (7 and 8.5) and concentration of 0.25 M had been found to be the optimum conditions for maximum 56% and 67% color removal using sodium chloride (NaCl) and potassium chloride (KCl) salts respectively. The actual color removal at optimal conditions was found to be 53% and 64% respectively for NaCl and KCl salts which confirms close to RSM results. The effects of storage duration and temperature on MOC studied reveal that coagulation efficiency of MOC kept at room temperature was effective for 3 days and at 4 degrees C it performed coagulation up to 5 days.

Development of novel nanocomposite adsorbent based on potassium nickel hexacyanoferrate-loaded polypropylene fabric.

PubMed

Bondar, Yuliia; Kuzenko, Svetlana; Han, Do-Hung; Cho, Hyun-Kug

2014-01-01

A nanocomposite adsorbent based on potassium nickel hexacyanoferrate-loaded polypropylene fabric was synthesized for selective removal of Cs ions from contaminated waters by a two-stage synthesis: radiation-induced graft polymerization of acrylic acid monomer onto the nonwoven polypropylene fabric surface with subsequent in situ formation of potassium nickel hexacyanoferrate (KNiHCF) nanoparticles within the grafted chains. Data of scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy confirmed the formation of KNiHCF homogeneous phase on the fabric surface, which consisted of crystalline cubic-shaped nanoparticles (70 to 100 nm). The efficiency of the synthesized adsorbent for removal of cesium ions was evaluated under various experimental conditions. It has demonstrated a rapid adsorption process, high adsorption capacity over a wide pH range, and selectivity in Cs ion removal from model solutions with high concentration of sodium ions.

Effective removal of coordinated copper from wastewater using a new dithiocarbamate-type supramolecular heavy metal precipitant.

PubMed

Fu, Fenglian; Zeng, Haiyan; Cai, Qinhong; Qiu, Rongliang; Yu, Jimmy; Xiong, Ya

2007-11-01

A new dithiocarbamate-type heavy metal precipitant, sodium 1,3,5-hexahydrotriazinedithiocarbamate (HTDC), was prepared and used to remove coordinated copper from wastewater. In the reported dithiocarbamate-type precipitants, HTDC possesses the highest percentage of the effective functional groups. It could effectively precipitate copper to less than 0.5mgl(-1) from both synthetic and actual industrial wastewater containing CuEDTA in the range of pH 3-9. UV-vis spectral investigation and elemental analysis suggested that the precipitate was a kind of coordination supramolecular compound, [Cu(3)(HTDC)(2)](n). The toxicity characteristic leaching procedure (TCLP) and semi-dynamic leaching test (SDLT) indicated that the supramolecular precipitate was non-hazardous and stable in weak acid and alkaline conditions. Tests of an anion exchange resin D231 provided a clue to simultaneously remove excess HTDC and residual CuEDTA in practical process of wastewater treatment.

Development of novel nanocomposite adsorbent based on potassium nickel hexacyanoferrate-loaded polypropylene fabric

PubMed Central

2014-01-01

A nanocomposite adsorbent based on potassium nickel hexacyanoferrate-loaded polypropylene fabric was synthesized for selective removal of Cs ions from contaminated waters by a two-stage synthesis: radiation-induced graft polymerization of acrylic acid monomer onto the nonwoven polypropylene fabric surface with subsequent in situ formation of potassium nickel hexacyanoferrate (KNiHCF) nanoparticles within the grafted chains. Data of scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy confirmed the formation of KNiHCF homogeneous phase on the fabric surface, which consisted of crystalline cubic-shaped nanoparticles (70 to 100 nm). The efficiency of the synthesized adsorbent for removal of cesium ions was evaluated under various experimental conditions. It has demonstrated a rapid adsorption process, high adsorption capacity over a wide pH range, and selectivity in Cs ion removal from model solutions with high concentration of sodium ions. PMID:24725367

Comparison of adsorption equilibrium models and error functions for the study of sulfate removal by calcium hydroxyapatite microfibrillated cellulose composite.

PubMed

Hokkanen, Sanna; Bhatnagar, Amit; Koistinen, Ari; Kangas, Teija; Lassi, Ulla; Sillanpää, Mika

2018-04-01

In the present study, the adsorption of sulfates of sodium sulfate (Na 2 SO 4 ) and sodium lauryl sulfate (SLS) by calcium hydroxyapatite-modified microfibrillated cellulose was studied in the aqueous solution. The adsorbent was characterized using elemental analysis, Fourier transform infrared, scanning electron microscope and elemental analysis in order to gain the information on its structure and physico-chemical properties. The adsorption studies were conducted in batch mode. The effects of solution pH, contact time, the initial concentration of sulfate and the effect of competing anions were studied on the performance of synthesized adsorbent for sulfate removal. Adsorption kinetics indicated very fast adsorption rate for sulfate of both sources (Na 2 SO 4 and SLS) and the adsorption process was well described by the pseudo-second-order kinetic model. Experimental maximum adsorption capacities were found to be 34.53 mg g -1 for sulfates of SLS and 7.35 mg g -1 for sulfates of Na 2 SO 4. The equilibrium data were described by the Langmuir, Sips, Freundlich, Toth and Redlich-Peterson isotherm models using five different error functions.

Waste separation and pretreatment using crystalline silicotitanate ion exchangers

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

Tadros, M.E.; Miller, J.E.; Anthony, R.G.

1997-10-01

A new class of inorganic ion exchangers called crystalline silicotitanates (CSTs) has been developed jointly by Sandia National Laboratories and Texas A&M University to selectively remove Cs and other radionuclides from a wide spectrum of radioactive defense wastes. The CST exhibits high selectivity and affinity for Cs and Sr under a wide range of conditions. Tests show it can remove part-per-million concentrations of Cs{sup +} from highly alkaline, high-sodium simulated radioactive waste solutions modeled after those at Hanford, Oak Ridge, and Savannah River. The materials exhibit ion exchange properties based on ionic size selectivity. Specifically, crystalline lattice spacing is controlledmore » to be highly selective for Cs ions even in waste streams containing very high (5 to 10 M) concentrations of sodium. The CST technology is being demonstrated with actual waste at several DOE facilities. The use of inorganic ion exchangers. The inorganics are more resistant to chemical, thermal, and radiation degradation. Their high selectivities result in more efficient operations offering the possibility of a simple single-pass operation. In contrast, regenerable organic ion exchangers require additional processing equipment to handle the regeneration liquids and the eluant with the dissolved Cs.« less

Biosorption of trivalent chromium by free and immobilized blue green algae: kinetics and equilibrium studies.

PubMed

Shashirekha, V; Sridharan, M R; Swamy, Mahadeswara

2008-03-01

The process of biosorption of trivalent chromium (Cr(3+)) by live culture of Spirulina platensis and the sorption potential by the dried biomass, in both free and immobilized states have been investigated for a simulated chrome liquor in the concentration range of 100-4500 ppm. Both live and dried biomass were very good biosorbents as they could remove high amounts of chromium from tannery wastewater. Polyurethane foam and sodium alginate were used as immobilizing agents and their performances compared. Biosorption kinetic data on Cr(3+) sorption onto dried biomass were analyzed using pseudo-first-and pseudo-second-order kinetic models in batch column experiments. The second-order equation was more appropriate to predict the rate of biosorption. Subsequently, the effects of height of packing & diameter of the column, concentration of blue-green algae (BGA) in varying amounts of sodium alginate, chromium concentration were studied. The results fit into both Langmuir & Freundlich isotherm models with very high regression coefficients. Furthermore, equilibrium studies using retan chrome liquor (RCL), with a chromium concentration of 1660 ppm, obtained from a tannery also showed promising results. In general, our studies indicate the efficacy of the algal species in removal of chromium from tannery wastewater.

Simple Sodium Dodecyl Sulfate-Assisted Sample Preparation Method for LC-MS-based Proteomic Applications

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

Zhou, Jianying; Dann, Geoffrey P.; Shi, Tujin

2012-03-10

Sodium dodecyl sulfate (SDS) is one of the most popular laboratory reagents used for highly efficient biological sample extraction; however, SDS presents a significant challenge to LC-MS-based proteomic analyses due to its severe interference with reversed-phase LC separations and electrospray ionization interfaces. This study reports a simple SDS-assisted proteomic sample preparation method facilitated by a novel peptide-level SDS removal protocol. After SDS-assisted protein extraction and digestion, SDS was effectively (>99.9%) removed from peptides through ion substitution-mediated DS- precipitation with potassium chloride (KCl) followed by {approx}10 min centrifugation. Excellent peptide recovery (>95%) was observed for less than 20 {mu}g of peptides.more » Further experiments demonstrated the compatibility of this protocol with LC-MS/MS analyses. The resulting proteome coverage from this SDS-assisted protocol was comparable to or better than those obtained from other standard proteomic preparation methods in both mammalian tissues and bacterial samples. These results suggest that this SDS-assisted protocol is a practical, simple, and broadly applicable proteomic sample processing method, which can be particularly useful when dealing with samples difficult to solubilize by other methods.« less

Efficacy of sodium hypochlorite, ethylenediaminetetraacetic acid, citric acid and phosphoric acid in calcium hydroxide removal from the root canal: a microscopic cleanliness evaluation.

PubMed

da Silva, Juliana Melo; Silveira, Amanda; Santos, Elizandra; Prado, Laiìs; Pessoa, Oscar F

2011-12-01

Rooted molars were subjected to standardized canal instrumentation to a master apical file (MAF). The samples were dressed with Ca(OH)(2), and after 7 days, teeth were reopened and Ca(OH)(2) medication was removed by 1 of 4 different experimental procedures: 2.5% sodium hypochlorite (NaOCl) (n = 10); 17% EDTA-T (n = 10); 10% citric acid (n = 10); or 37% phosphoric acid (n = 10). This was followed by reinstrumentation with MAF plus 15 mL saline solution. The roots were prepared for scanning electron microscopic analysis of the cervical, middle, and apical thirds. Statistical analysis was performed with the Kruskal-Wallis test. EDTA-T and phosphoric acid gave the best results in the apical third, with significant statistical differences compared with other groups. NaOCl gave the worst results. Irrigation with 17% EDTA-T and 37% phosphoric acid is more effective than sodium hypochlorite and citric acid in the removal of calcium hydroxide from the apical third. Copyright © 2011 Mosby, Inc. All rights reserved.

Alkaline Peroxides Versus Sodium Hypochlorite for Removing Denture Biofilm: a Crossover Randomized Trial.

PubMed

Peracini, Amanda; Regis, Rômulo Rocha; Souza, Raphael Freitas de; Pagnano, Valéria Oliveira; Silva, Cláudia Helena Lovato da; Paranhos, Helena de Freitas Oliveira

2016-01-01

This study evaluated the efficacy of cleanser solutions on denture biofilm removal by a crossover randomized clinical trial. Thirty two edentulous patients were instructed to brush their dentures (specific brush and liquid soap) three times a day (after breakfast, lunch and dinner) and to soak them (≥ 8 h) in: (C) control -water; (AP): alkaline peroxide; or (SH) 0.5% sodium hypochlorite. Each solution was used for 21 days (three cycles of 7 days). At the end of each cycle, the inner surfaces of maxillary dentures were disclosed (1% neutral red) and photographed (HX1 - Sony). Areas (total and stained biofilm) were measured (Image Tool software) and the percentage of biofilm calculated as the ratio between the area of the biofilm multiplied by 100 and total surface area of the internal base of the denture. Data were compared by means of generalized estimating equation (α=5%) and multiple comparisons (Bonferroni; α=1.67%). Immersion in SH reduced biofilm (%) (8.3 ± 13.3B) compared to C (18.2 ± 14.9A) and AP (18.2 ± 16.6A). The 0.5% sodium hypochlorite solution was the most efficacious for biofilm removal. Alkaline peroxides may not lead to further biofilm removal in patients with adequate denture maintenance habits.

Determination of Arsenical Herbicide Residues in Plant Tissues

Treesearch

R.M. Sachs; J.L. Michael; F.B. Anastasia; W.A. Wells

1971-01-01

Paper chromatographic separation of hydroxydimethylarsine oxide (cacodylic acid), monosodium methanearsonate (MSMA), sodium arsenate, and sodium arsenite was achieved with the aid of four solvent systems. Aqueous extracts of plant tissues removed essentially all the arscnicals applied, but mechanoiic fractionation was required before the extracts could be analyzed by...

Effect of phenytoin on sodium conductances in rat hippocampal CA1 pyramidal neurons

PubMed Central

Zeng, Zhen; Hill-Yardin, Elisa L.; Williams, David; O'Brien, Terence; Serelis, Andris

2016-01-01

The antiepileptic drug phenytoin (PHT) is thought to reduce the excitability of neural tissue by stabilizing sodium channels (NaV) in inactivated states. It has been suggested the fast-inactivated state (IF) is the main target, although slow inactivation (IS) has also been implicated. Other studies on local anesthetics with similar effects on sodium channels have implicated the NaV voltage sensor interactions. In this study, we reexamined the effect of PHT in both equilibrium and dynamic transitions between fast and slower forms of inactivation in rat hippocampal CA1 pyramidal neurons. The effects of PHT were observed on fast and slow inactivation processes, as well as on another identified “intermediate” inactivation process. The effect of enzymatic removal of IF was also studied, as well as effects on the residual persistent sodium current (INaP). A computational model based on a gating charge interaction was derived that reproduced a range of PHT effects on NaV equilibrium and state transitions. No effect of PHT on IF was observed; rather, PHT appeared to facilitate the occupancy of other closed states, either through enhancement of slow inactivation or through formation of analogous drug-bound states. The overall significance of these observations is that our data are inconsistent with the commonly held view that the archetypal NaV channel inhibitor PHT stabilizes fast inactivation states, and we demonstrate that conventional slow activation “IS” and the more recently identified intermediate-duration inactivation process “II” are the primary functional targets of PHT. In addition, we show that the traditional explanatory frameworks based on the “modulated receptor hypothesis” can be substituted by simple, physiologically plausible interactions with voltage sensors. Additionally, INaP was not preferentially inhibited compared with peak INa at short latencies (50 ms) by PHT. PMID:27489371

Sodium and Potassium Fluxes in Isolated Barnacle Muscle Fibers

PubMed Central

Brinley, F. J.

1968-01-01

Sodium and potassium influxes and outfluxes have been studied in single isolated muscle fibers from the giant barnacle both by microinjection and by external loading. The sodium influxes and outfluxes were 49 and 39 pmoles /cm2-sec (temperature = 15–16°C) respectively. The potassium influxes and outfluxes were 28 and 60 pmoles/cm2-sec (temperature = 13–16°C) respectively. Replacement of external sodium by lithium reduced sodium outflux by 67% but had no effect on potassium outflux. Removal of external potassum reduced the sodium outflux by 51% but had no effect on potassium outflux. External strophanthidin (10–30 µM) reduced sodium outflux by 80–90% and increased potassium outflux by 40% in normal fibers. The time constant for sodium exchange increased linearly with internal sodium concentration, as did the fraction of sodium outflux insensitive to a maximally inhibitory concentration of external strophanthidin in the range of 10 tO 80 mM internal sodium. The strophanthidin-sensitive component of sodium outflux could be related to the internal sodium concentration by the following empirical formula: See PDF for Equation PMID:5651768

Regeneration of pilot-scale ion exchange columns for hexavalent chromium removal.

PubMed

Korak, Julie A; Huggins, Richard; Arias-Paic, Miguel

2017-07-01

Due to stricter regulations, some drinking water utilities must implement additional treatment processes to meet potable water standards for hexavalent chromium (Cr(VI)), such as the California limit of 10 μg/L. Strong base anion exchange is effective for Cr(VI) removal, but efficient resin regeneration and waste minimization are important for operational, economic and environmental considerations. This study compared multiple regeneration methods on pilot-scale columns on the basis of regeneration efficiency, waste production and salt usage. A conventional 1-Stage regeneration using 2 N sodium chloride (NaCl) was compared to 1) a 2-Stage process with 0.2 N NaCl followed by 2 N NaCl and 2) a mixed regenerant solution with 2 N NaCl and 0.2 N sodium bicarbonate. All methods eluted similar cumulative amounts of chromium with 2 N NaCl. The 2-Stage process eluted an additional 20-30% of chromium in the 0.2 N fraction, but total resin capacity is unaffected if this fraction is recycled to the ion exchange headworks. The 2-Stage approach selectively eluted bicarbonate and sulfate with 0.2 N NaCl before regeneration using 2 N NaCl. Regeneration approach impacted the elution efficiency of both uranium and vanadium. Regeneration without co-eluting sulfate and bicarbonate led to incomplete uranium elution and potential formation of insoluble uranium hydroxides that could lead to long-term resin fouling, decreased capacity and render the resin a low-level radioactive solid waste. Partial vanadium elution occurred during regeneration due to co-eluting sulfate suppressing vanadium release. Waste production and salt usage were comparable for the 1- and 2-Stage regeneration processes with similar operational setpoints with respect to chromium or nitrate elution. Published by Elsevier Ltd.

Manipulation of the sodium-potassium ratio as a lever for controlling cell growth and improving cell specific productivity in perfusion CHO cell cultures.

PubMed

Wang, Samantha B; Lee-Goldman, Alexandria; Ravikrishnan, Janani; Zheng, Lili; Lin, Henry

2018-04-01

Perfusion processes typically require removal of a continuous or semi-continuous volume of cell culture in order to maintain a desired target cell density. For fast growing cell lines, the product loss from this stream can be upwards of 35%, significantly reducing the overall process yield. As volume removed is directly proportional to cell growth, the ability to modulate growth during perfusion cell culture production thus becomes crucial. Leveraging existing media components to achieve such control without introducing additional supplements is most desirable because it decreases process complexity and eliminates safety and clearance concerns. Here, the impact of extracellular concentrations of sodium (Na) and potassium (K) on cell growth and productivity is explored. High throughput small-scale models of perfusion revealed Na:K ratios below 1 can significantly suppress cell growth by inducing cell cycle arrest in the G0/1 phase. A concomitant increase in cell specific productivity was also observed, reaching as high as 115 pg/cell/day for one cell line studied. Multiple recombinant Chinese hamster ovary (CHO) cell lines demonstrated similar responses to lower Na:K media, indicating the universal applicability of such an approach. Product quality attributes were also assessed and revealed that effects were cell line specific, and can be acceptable or manageable depending on the phase of the drug development. Drastically altering Na and K levels in perfusion media as a lever to impact cell growth and productivity is proposed. © 2017 Wiley Periodicals, Inc.

Synthesis of sodium lauryl sulphate (SLS)-modified activated carbon from risk husk for waste lead (Pb) removal

NASA Astrophysics Data System (ADS)

Al-Latief, D. N.; Arnelli, Astuti, Y.

2015-12-01

Surfactant-modified active carbon (SMAC) has been successfully synthesized from waste rice husk using a series of treatments i.e. carbonization, activation with H3PO4 and surface modification using sodium lauryl sulfate (SLS). The synthesized SMAC was characterized using SEM-EDX and FTIR. The adsorption results show that the SMAC synthesized using H3PO4 treatment for 8 hours followed with SLS treatment for 5 hours had efficiency and capacity of the waste lead removal of 99.965% and 0.499825 mg.g-1, respectively.

The simultaneous removal of calcium, magnesium and chloride ions from industrial wastewater using magnesium-aluminum oxide.

PubMed

Hamidi, Roya; Kahforoushan, Davood; Fatehifar, Esmaeil

2013-01-01

In this article, a method for simultaneous removal of calcium, magnesium and chloride by using Mg0.80Al0.20O1.10 as a Magnesium-Aluminum oxide (Mg‒Al oxide) was investigated. Mg‒Al oxide obtained by thermal decomposition of the Mg-Al layered double hydroxide (Mg-Al LDH). The synthesized Mg‒Al oxide were characterized with respect to nitrogen physicosorption, X-ray diffraction (XRD) and field emission scan electron microscopy (FESEM) morphology. Due to high anion-exchange capacity of Mg‒Al oxide, it was employed in simultaneously removal of Cl(-), Mg(+2) and Ca(+2) from distiller waste of a sodium carbonate production factory. For this purpose, experiments were designed to evaluate the effects of quantity of Mg‒Al oxide, temperature and time on the removal process. The removal of Cl(-), Mg(+2) and Ca(+2) from wastewater was found 93.9%, 93.74% and 93.25% at 60°C after 0.5 h, respectively. Results showed that the removal of Cl(-), Mg(+2) and Ca(+2) by Mg‒Al oxide increased with increasing temperature, time and Mg‒Al oxide quantity.

PROCESS FOR THE RECOVERY OF PLUTONIUM

DOEpatents

Ritter, D.M.

1959-01-13

An improvement is presented in the process for recovery and decontamination of plutonium. The carrier precipitate containing plutonium is dissolved and treated with an oxidizing agent to place the plutonium in a hexavalent oxidation state. A lanthanum fluoride precipitate is then formed in and removed from the solution to carry undesired fission products. The fluoride ions in the reniaining solution are complexed by addition of a borate sueh as boric acid, sodium metaborate or the like. The plutonium is then reduced and carried from the solution by the formation of a bismuth phosphate precipitate. This process effects a better separation from unwanted flssion products along with conccntration of the plutonium by using a smaller amount of carrier.

Inactivation of enveloped and non-enveloped viruses in the process of chemical treatment and gamma irradiation of bovine-derived grafting materials.

PubMed

Lee, Kwang-Il; Lee, Jung-Soo; Jung, Hong-Hee; Lee, Hwa-Yong; Moon, Seong-Hwan; Kang, Kyoung-Tak; Shim, Young-Bock; Jang, Ju-Woong

2012-01-01

Xenografts, unlike other grafting products, cannot be commercialized unless they conform to stringent safety regulations. Particularly with bovine-derived materials, it is essential to remove viruses and inactivate infectious factors because of the possibility that raw materials are imbrued with infectious viruses. The removal of the characteristics of infectious viruses from the bovine bone grafting materials need to be proved and inactivation process should satisfy the management provision of the Food and Drug Administration (FDA). To date, while most virus inactivation studies were performed in human allograft tissues, there have been almost no studies on bovine bone. To evaluate the efficacy of virus inactivation after treatment of bovine bone with 70% ethanol, 4% sodium hydroxide, and gamma irradiation, we selected a variety of experimental model viruses that are known to be associated with bone pathogenesis, including bovine parvovirus (BPV), bovine herpes virus (BHV), bovine viral diarrhea virus (BVDV), and bovine parainfluenza-3 virus (BPIV-3). The cumulative virus log clearance factor or cumulative virus log reduction factor for the manufacturing process was obtained by calculating the sum of the individual virus log clearance factors or log reduction factors determined for individual process steps with different physicochemical methods. The cumulative log clearance factors achieved by three different virus inactivation processes were as follows: BPV ≥ 17.73, BHV ≥ 20.53, BVDV ≥ 19.00, and BPIV-3 ≥ 16.27. On the other hand, the cumulative log reduction factors achieved were as follows: BPV ≥ 16.95, BHV ≥ 20.22, BVDV ≥ 19.27, and BPIV-3 ≥ 15.58. Treatment with 70% ethanol, 4% sodium hydroxide, or gamma irradiation was found to be very effective in virus inactivation, since all viruses were at undetectable levels during each process. We have no doubt that application of this established process to bovine bone graft manufacture will be effective and essential. © 2012 John Wiley & Sons A/S.

Characterization of sophorolipid biosurfactant produced by Cryptococcus sp. VITGBN2 and its application on Zn(II) removal from electroplating wastewater.

PubMed

Basak, Geetanjali; Das, Nilanjana

2014-11-01

The present study aimed at elucidating the role of biosurfactant produced by yeast for the removal of Zn(II) ions from electroplating wastewater. The yeast species isolated from CETP, Vellore, Tamilnadu was identified as Cryptococcus sp.VITGBN2, based on molecular techniques, and was found to be potent producer of biosurfactant in mineral salt media containing vegetable oil as additional carbon source. Chemical structure of the purified biosurfactant was identified as acidic diacetate sophorolipid through GC-MS analysis. Interaction of Zn(II) ions with biosurfactant was monitored using FT-IR, SEM and EDS analysis. Zn (II) removal at 100 mg l(-1) concentration was 84.8% compared were other synthetic surfactants (Tween 80 and sodium dodecyl sulphate), yeast mediated biosurfactant showed enhanced Zn (II) removal in batch mode. The role of biosurfactant on Zn(II) removal was evaluated in column mode packed with biosurfactant entrapped in sodium alginate beads. At a flow rate of 1 ml min(-1) and bed height of 12 cm, immobilized biosurfactant showed 94.34% Zn(II) removal from electroplating wastewater. The present study confirmed that Zn(II) removal was biosurfactant mediated. This is the first report establishing the involvement of yeast mediated biosurfactant in Zn(II) removal from wastewater.

A Core Facility for the Study of Neurotoxins of Biological Origin

DTIC Science & Technology

1987-06-15

the animals were sacrificed with an intravenous overdose of sodium pentobarbital. The spilnal cords were removed rapidly and frozen in isopentane...control muscle receives no drug during 45Ca washout. Results: Ryanodine contracture 1. The effect of replacement of sodium by choline to block Na+ for...sodium by choline lowers the concentra- tion of ryanodine to cause a contracture from 10-4 M to 10- 6M and reduces the half time to peak tension from

Io, the closest Galileo's Medicean Moon: Changes in its Sodium Cloud Caused by Jupiter Eclipse

NASA Astrophysics Data System (ADS)

Grava, Cesare; Schneider, Nicholas M.; Barbieri, Cesare

2010-01-01

We report results of a study of true temporal variations in Io's sodium cloud before and after eclipse by Jupiter. The eclipse geometry is important because there is a hypothesis that the atmosphere partially condenses when the satellite enters the Jupiter's shadow, preventing sodium from being released to the cloud in the hours immediately after the reappearance. The challenge lies in disentangling true variations in sodium content from the changing strength of resonant scattering due Io's changing Doppler shift in the solar sodium absorption line. We undertook some observing runs at Telescopio Nazionale Galileo (TNG) at La Palma Canary Island with the high resolution spectrograph SARG in order to observe Io entering into Jupiter's shadow and coming out from it. The particular configuration chosen for the observations allowed us to observe Io far enough from Jupiter and to disentangle line-of-sight effects looking perpendicularly at the sodium cloud. We will present results which took advantage of a very careful reduction strategy. We remove the dependence from γ-factor, which is the fraction of solar light available for resonant scattering, in order to remove the dependence on the radial velocity of Io with respect to the Sun. This work has been supported by NSF's Planetary Astronomy Program, INAF/TNG and the Department of Astronomy and Cisas of University of Padova, through a contract by the Italian Space Agency ASI.

Nitrogen removal from digested slurries using a simplified ammonia stripping technique.

PubMed

Provolo, Giorgio; Perazzolo, Francesca; Mattachini, Gabriele; Finzi, Alberto; Naldi, Ezio; Riva, Elisabetta

2017-11-01

This study assessed a novel technique for removing nitrogen from digested organic waste based on a slow release of ammonia that was promoted by continuous mixing of the digestate and delivering a continuous air stream across the surface of the liquid. Three 10-day experiments were conducted using two 50-L reactors. In the first two, nitrogen removal efficiencies were evaluated from identical digestates maintained at different temperatures (30°C and 40°C). At the start of the first experiment, the digestates were adjusted to pH 9 using sodium hydroxide, while in the second experiment pH was not adjusted. The highest ammonia removal efficiency (87%) was obtained at 40°C with pH adjustment. However at 40°C without pH adjustment, removal efficiencies of 69% for ammonia and 47% for total nitrogen were obtained. In the third experiment two different digestates were tested at 50°C without pH adjustment. Although the initial chemical characteristics of the digestates were different in this experiment, the ammonia removal efficiencies were very similar (approximately 85%). Despite ammonia removal, the pH increased in all experiments, most likely due to carbon dioxide stripping that was promoted by temperature and mixing. The technique proved to be suitable for removing nitrogen following anaerobic digestion of livestock manure because effective removal was obtained at natural pH (≈8) and 40°C, common operating conditions at typical biogas plants that process manure. Furthermore, the electrical energy requirement to operate the process is limited (estimated to be 3.8kWhm -3 digestate). Further improvements may increase the efficiency and reduce the processing time of this treatment technique. Even without these advances slow-rate air stripping of ammonia is a viable option for reducing the environmental impact associated with animal manure management. Copyright © 2017 Elsevier Ltd. All rights reserved.

High sodium coal-firing experiences at Basin Electric Power Cooperative's Leland Olds Station

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

Laning, V.R.; Bartle, M.L.

1982-12-01

This paper describes some of the efforts made at the Leland Olds Station to cope with the problems created from high sodium content coals. Such coals have historically presented superheater fouling problems for utilities; ash deposits from high sodium coals have a very high sintering strength and are very difficult to remove by conventional methods. It is reported that the addition of limestone in the pulverizer unit at Leland Olds and vermiculite ore in the cyclone unit has helped reduce the fouling characteristics of high sodium lignites in North Dakota at an affordable cost.

Occurrence and distribution of selected pharmaceuticals and personal care products in aquatic environments: a comparative study of regions in China with different urbanization levels.

PubMed

Chen, Hong; Li, Xiaojuan; Zhu, Saichang

2012-07-01

We analyzed and compared the distributions of 13 target pharmaceuticals in different water samples from the Hangzhou metropolitan area and Linan County, Southeast China. Sampling was conducted in five hospitals, two wastewater treatment plants (WWTPs), and Qiantang River. Samples were concentrated by solid-phase extraction and PPCP concentrations were determined by UPLC-MS/MS. Trimethoprim, erythromycin A dihydrate, norfloxacin, ofloxacin, diclofenac sodium, and atenolol were the most frequently detected pharmaceuticals in hospital effluents. Most of the pharmaceutical concentrations in hospital effluents were higher than those in the WWTP influents. Although both WWTPs adopt the anaerobic-aerobic-anoxic treatment process, the removal rates for pharmaceuticals, such as trimethoprim and diclofenac sodium, were completely different. Meanwhile, erythromycin A dihydrate, ofloxacin, penicillin-G, cephalexin, cefazolin, ibuprofen, and diclofenac sodium were detected in Qiantang River. These results indicate that hospitals are more concentrated sources of pharmaceuticals than WWTPs, and the WWTPs are not the only route of entry of pharmaceuticals into aquatic environments in these two regions.

Ion transport mechanisms in cultured bovine corneal endothelial cells.

PubMed

Jentsch, T J; Keller, S K; Wiederholt, M

1985-04-01

Intracellular potential measurements of confluent monolayers of cultured bovine corneal endothelial cells were used to define passive ion transport processes in these cells. Previous studies (Jentsch et al., J. Membr. Biol. 78:103 (1984); Jentsch et al., J. Membr. Biol. 81:189 (1984] have provided the experimental basis for a cellular model, in which bicarbonate entry across the basolateral membrane is indirectly driven by a Na+/H+-exchanger, which is inhibitable by amiloride (1mM). Bicarbonate and sodium should leave the cell via an electrogenic bicarbonate sodium cotransport, which is inhibitable by the disulfonic stilbene derivates SITS or DIDS. This model is also consistent with results from transendothelial studies. In this paper, we briefly review the evidence we have obtained for this model and demonstrate, that the electrical response to sodium (depolarization upon Na+-removal) is neither due to an inhibition of Na+/K+-ATPase nor explainable in terms of changes in K+-conductance. This is concluded from the observation of these responses in the presence of ouabain (10(-4)M) or barium (1mM).

Removal of anionic surfactant sodium dodecyl benzene sulfonate (SDBS) from wastewaters by zero-valent iron (ZVI): predominant removal mechanism for effective SDBS removal.

PubMed

Takayanagi, Akari; Kobayashi, Maki; Kawase, Yoshinori

2017-03-01

Mechanisms for removal of anionic surfactant sodium dodecyl benzene sulfonate (SDBS) in wastewaters by zero-valent iron (ZVI) were systematically examined. The contributions of four removal mechanisms, i.e., reductive degradation, oxidative degradation, adsorption, and precipitation, changed significantly with solution pH were quantified and the effective removal of SDBS by ZVI was found to be attributed to the adsorption capability of iron oxides/hydroxides on ZVI surface at nearly neutral pH instead of the degradation at acidic condition. The fastest SDBS removal rate and the maximum TOC (total organic carbon) removal efficiency were obtained at pH 6.0. The maximum TOC removal at pH 6.0 was 77.8%, and the contributions of degradation, precipitation, and adsorption to TOC removal were 4.6, 14.9, and 58.3%, respectively. At pH 3.0, which is an optimal pH for oxidative degradation by the Fenton reaction, the TOC removal was only 9.8% and the contributions of degradation, precipitation, and adsorption to TOC removal were 2.3, 4.6, and 2.9%, respectively. The electrostatic attraction between dodecyl benzene sulfate anion and the iron oxide/hydroxide layer controlled the TOC removal of SDBS. The kinetic model based on the Langmuir-Hinshelwood/Eley-Rideal approach could successfully describe the experimental results for SDBS removal by ZVI with the averaged correlation coefficient of 0.994. ZVI was found to be an efficient material toward the removal of anionic surfactant at nearly neutral pH under the oxic condition.

FT–Raman investigation of bleaching of spruce thermomechanical pulp

Treesearch

U.P. Agarwal; L.L. Landucci

2004-01-01

Spruce thermomechanical pulp was bleached initially by alkaline hydrogen peroxide and then by sodium dithionite and sodium borohydride. Near-infrared Fourier-transform–Raman spectroscopy revealed that spectral differences were due primarily to coniferaldehyde and p-quinone structures in lignin, new direct evidence that bleaching removes p-quinone structures. In...

Evaluation of Military Field-Water Quality. Volume 3. Opportunity Poisons

DTIC Science & Technology

1987-12-01

Acidic chemical cleaners fluoric acid, nitric acid, perchloric Spent acid acid, sulfuric acid Alkalies Miscellaneous caustic products Ammonia, lime...calcium oxide), potassium Alkaline battery fluid hydroxide, sodium hydroxide, sodium Caustic wastewater silicate Cleaning solutions Lye Nonhalogenated...Laboratory chemicals chloride, polychlorinated biphenyls, zinc Paint and varnish removers naphthenate , copper naphthenate , dichloro- Capacitors and

Monitoring sodium removal and delivered dialysis by conductivity.

PubMed

Locatelli, F; Di Filippo, S; Manzoni, C; Corti, M; Andrulli, S; Pontoriero, G

1995-11-01

As cardiovascular stability and the delivery of the prescribed dialysis "dose" seem to be the main factors in determining the morbidity and mortality of hemodialyzer patients today, it is of paramount importance to match hydro-sodium removal with interdialytic load and to verify the delivered dialysis at each session. A specially designed Biofeedback Module (BM--COT Hospal) allows the automatic determination of plasma water conductivity and effective ionic dialysance with no need for blood samples. Using BM, we evaluated the validity of "conductivity kinetic modelling" (CKM) and the possibility that this may substitute "sodium kinetic modelling". Moreover, we evaluated the "in vivo" relationship between ionic dialysance and effective urea clearance. Our results demonstrate that: 1) CKM makes it possible to obtain programmed end-dialysis plasma water conductivity with an error of less than +/- 0.14 mS/cm, roughly equivalent to a sodium concentration of +/- 1.4 mEq/L. 2). Ionic dialysance and effective urea clearance are not equivalent but, as the interrelationship between these is known, the BM allows the routine monitoring of delivered dialysis.

Removal of fluoride, SDS, ammonia and turbidity from semiconductor wastewater by combined electrocoagulation-electroflotation.

PubMed

Aoudj, S; Khelifa, A; Drouiche, N

2017-08-01

Semiconductor industry effluents contain organic and inorganic pollutants, such as sodium dodecyl sulfate (SDS), fluoride and ammonia, at high levels which consists a major environmental issue. A combined EC-EF process is proposed as a post-treatment after precipitation for simultaneous clarification and removal of pollutants. In EC step, a hybrid Fe-Al was used as the soluble anode in order to avoid supplementary EC step. EC-Fe is more suitable for SDS removal; EC-Al is more suitable for fluoride removal, while EC with hybrid Al-Fe makes a good compromise. Clarification and ammonia oxidation were achieved in the EF step. Effects of anodic material, initial pH, current, anion nature, chloride concentration and initial pollutant concentration were studied. The final concentrations may reach 0.27, 6.23 and 0.22 mg L -1 for SDS, fluoride and ammonia respectively. These concentrations are far lower than the correspondent discharge limits. Similarly, the final turbidity was found 4.35 NTU which is lower than 5NTU and the treated water does not need further filtration before discharge. Furthermore, the EC-EF process proves to be sufficiently energy-efficient with less soluble electrode consumption. Copyright © 2017 Elsevier Ltd. All rights reserved.

SIMULANT DEVELOPMENT FOR SAVANNAH RIVER SITE HIGH LEVEL WASTE

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

Stone, M; Russell Eibling, R; David Koopman, D

2007-09-04

The Defense Waste Processing Facility (DWPF) at the Savannah River Site vitrifies High Level Waste (HLW) for repository internment. The process consists of three major steps: waste pretreatment, vitrification, and canister decontamination/sealing. The HLW consists of insoluble metal hydroxides (primarily iron, aluminum, magnesium, manganese, and uranium) and soluble sodium salts (carbonate, hydroxide, nitrite, nitrate, and sulfate). The HLW is processed in large batches through DWPF; DWPF has recently completed processing Sludge Batch 3 (SB3) and is currently processing Sludge Batch 4 (SB4). The composition of metal species in SB4 is shown in Table 1 as a function of the ratiomore » of a metal to iron. Simulants remove radioactive species and renormalize the remaining species. Supernate composition is shown in Table 2.« less

Effect of transient sodium chloride shock loads on the performance of submerged membrane bioreactor.

PubMed

Yogalakshmi, K N; Joseph, Kurian

2010-09-01

Membrane bioreactor (MBR) is a promising technological option to meet water reuse demands. Though MBR provides effluent quality of reusable standard, its versatility to shock loads remains unexplored. The present study investigates the robustness of MBR under sodium chloride shock load (5-60 g/L) conditions. A bench scale aerobic submerged MBR (6L working volume) with polyethylene hollow fiber membrane module (pore size 0.4 microm) was operated with synthetic wastewater at steady state OLR of 3.6g COD/L/d and HRT of 8h. This resulted in 99% TSS removal and 95% COD and TKN removal. The COD removal during the salt shock load was in the range of 84-64%. The TSS removal showed maximum disturbance (88%) with a corresponding decrease in biomass MLVSS by 8% at 60 g/L shock. TKN removal was reduced due to inhibition of nitrification with increasing shock loads. It took about 4-9 days for the MBR to regain its steady state performance. Copyright 2010 Elsevier Ltd. All rights reserved.

Phosphorus Elimination at Sodium Silicate from Quartz Sand Roasted with Complexation using Chitosan-EDTA

NASA Astrophysics Data System (ADS)

Wahyuningsih, S.; Ramelan, A. H.; Suharty, N. S.; Handayani, M.; Firdiyono, F.; Sulistiyono, E.; Munawaroh, H.; Sari, P. P.; Kristiawan, Y. R.

2018-03-01

A phosphorus elimination from sodium silicate solution has been studied. Phosphorus elimination was performed by adding chitosan-EDTA to remove cation phosphorus. Characterization of chitosan-EDTA material was performed using FT-IR, while the decreasing level of phosphorus content was analyzed by quantitative analysis using spectrophotometer UV-Vis refers to SNI 06-6989-2004. The results showed that the content of the sodium silicate can be reduced up to 67.1% through Chitosan-EDTA complexation with phosphorus.

Comparison of the Relative Risk of Molar Root Perforations Using Various Endodontic Instrumentation Techniques.

DTIC Science & Technology

1983-03-01

sodium hypochlorite using a standard endodontic irrigating syringe (Monoject Endodontic Syringe, Sherwood Medical Co., St. Louis, MO), and the...the sample. The Joel R. Kessler 8 teeth were placed in a 5.25% sodium hypochlorite solution for 30 minutes in order to remove soft tissue on the root...molars. J Endodon 1975;1:211-14. 7. Senia ES, Marshall FJ, Rosen S. The solvent action of sodium hypochlorite on pulp tissue of extracted teeth. Oral

Interaction of chloride and bicarbonate transport across the basolateral membrane of rabbit proximal straight tubule. Evidence for sodium coupled chloride/bicarbonate exchange.

PubMed Central

Sasaki, S; Yoshiyama, N

1988-01-01

The existence of chloride/bicarbonate exchange across the basolateral membrane and its physiologic significance were examined in rabbit proximal tubules. S2 segments of the proximal straight tubule were perfused in vitro and changes in intracellular pH (pHi) and chloride activity (aCli) were monitored by double-barreled microelectrodes. Total peritubular chloride replacement with gluconate increased pHi by 0.8, and this change was inhibited by a pretreatment with an anion transport inhibitor, SITS. Peritubular bicarbonate reduction increased aCli, and most of this increase was lost when ambient sodium was totally removed. The reduction rates of pHi induced by a peritubular bicarbonate reduction or sodium removal were attenuated by 20% by withdrawal of ambient chloride. SITS application to the bath in the control condition quickly increased pHi, but did not change aCli. However, the aCli slightly decreased in response to SITS when the basolateral bicarbonate efflux was increased by reducing peritubular bicarbonate concentration. It is concluded that sodium coupled chloride/bicarbonate exchange is present in parallel with sodium-bicarbonate cotransport in the basolateral membrane of the rabbit proximal tubule, and it contributes to the basolateral bicarbonate and chloride transport. PMID:2450891

THE MOVEMENT OF WATER IN TISSUES REMOVED FROM THE BODY AND ITS RELATION TO MOVEMENT OF WATER DURING LIFE

PubMed Central

Opie, Eugene L.

1949-01-01

During the initial period following immersion of parenchymatous cells of liver, kidney, or pancreas in various fluids immediately after their removal from the body water exchange is like that which occurs when water passes by osmosis through a semipermeable membrane; intake of water is proportional to the square root of the elapsed time and when liver tissue is immersed in solutions of sodium chloride movement of water is approximately proportional to the concentration of the solution. Solutions of sodium chloride isotonic for parenchymatous cells of liver have twice the molar concentration of sodium chloride in the blood serum; for those of the kidney slightly less than twice and for those of the pancreas three times this concentration. When interstitial tissue of thymus, omentum, or pancreas is immersed in water, it undergoes edema-like swelling caused by hydration of the colloids of the fibrous tissue; quantitative water exchange in an initial period accords with water movement by osmosis and is proportional to the square root of the elapsed time. Solutions of sodium chloride isotonic for fibrous tissue of the omentum have slightly greater molar concentration than the sodium chloride in the blood serum and for that of the thymus approximately the same as that of blood serum. Sodium chloride produces changes in fibrous tissue which increase with increasing concentration its power to hold water; the dense fibrous tissue of the corium of the skin and of the wall of the aorta takes up water in both weak an strong solutions of sodium chloride. The initial movement of water induced in tissues in the period immediately following removal from the body is dependent upon forces which are active during life but soon impaired by injury to the tissues. The molar concentration of the contents of secreting cells is greater than that of the blood serum and of the fluid surrounding them. These conditions are favorable to the passage of water from the tissue spaces to the cells. PMID:18107971

Passive shut-down heat removal system

DOEpatents

Hundal, Rolv; Sharbaugh, John E.

1988-01-01

An improved shut-down heat removal system for a liquid metal nuclear reactor of the type having a vessel for holding hot and cold pools of liquid sodium is disclosed herein. Generally, the improved system comprises a redan or barrier within the reactor vessel which allows an auxiliary heat exchanger to become immersed in liquid sodium from the hot pool whenever the reactor pump fails to generate a metal-circulating pressure differential between the hot and cold pools of sodium. This redan also defines an alternative circulation path between the hot and cold pools of sodium in order to equilibrate the distribution of the decay heat from the reactor core. The invention may take the form of a redan or barrier that circumscribes the inner wall of the reactor vessel, thereby defining an annular space therebetween. In this embodiment, the bottom of the annular space communicates with the cold pool of sodium, and the auxiliary heat exchanger is placed in this annular space just above the drawn-down level that the liquid sodium assumes during normal operating conditions. Alternatively, the redan of the invention may include a pair of vertically oriented, concentrically disposed standpipes having a piston member disposed between them that operates somewhat like a pressure-sensitive valve. In both embodiments, the cessation of the pressure differential that is normally created by the reactor pump causes the auxiliary heat exchanger to be immersed in liquid sodium from the hot pool. Additionally, the redan in both embodiments forms a circulation flow path between the hot and cold pools so that the decay heat from the nuclear core is uniformly distributed within the vessel.

Performance of ceramic ultrafiltration membranes and fouling behavior of a dye-polysaccharide binary system.

PubMed

Zuriaga-Agustí, E; Alventosa-deLara, E; Barredo-Damas, S; Alcaina-Miranda, M I; Iborra-Clar, M I; Mendoza-Roca, J A

2014-05-01

Ultrafiltration membrane processes have become an established technology in the treatment and reuse of secondary effluents. Nevertheless, membrane fouling arises as a major obstacle in the efficient operation of these systems. In the current study, the performance of tubular ultrafiltration ceramic membranes was evaluated according to the roles exerted by membrane pore size, transmembrane pressure and feed concentration on a binary foulant system simulating textile wastewater. For that purpose, carboxymethyl cellulose sodium salt (CMC) and an azo dye were used as colloidal and organic foulants, respectively. Results showed that a larger pore size enabled more solutes to get adsorbed into the pores, producing a sharp permeate flux decline attributed to the rapid pore blockage. Besides, an increase in CMC concentration enhanced severe fouling in the case of the tighter membrane. Concerning separation efficiency, organic matter was almost completely removed with removal efficiency above 98.5%. Regarding the dye, 93% of rejection was achieved. Comparable removal efficiencies were attributed to the dynamic membrane formed by the cake layer, which governed process performance in terms of rejection and selectivity. As a result, none of the evaluated parameters showed significant influence on separation efficiency, supporting the significant role of cake layer on filtration process. Copyright © 2014 Elsevier Ltd. All rights reserved.

Pretest predictions for degraded shutdown heat-removal tests in THORS-SHRS Assembly 1. [LMFBR

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

Rose, S.D.; Carbajo, J.J.

The recent modification of the Thermal-Hydraulic Out-of-Reactor Safety (THORS) facility at ORNL will allow testing of parallel simulated fuel assemblies under natural-convection and low-flow forced-convection conditions similar to those that might occur during a partial failure of the Shutdown Heat Removal System (SHRS) of an LMFBR. An extensive test program has been prepared and testing will be started in September 1983. THORS-SHRS Assembly 1 consists of two 19-pin bundles in parallel with a third leg serving as a bypass line and containing a sodium-to-sodium intermediate heat exchanger. Testing at low powers wil help indicate the maximum amount of heat thatmore » can be removed from the reactor core during conditions of degraded shutdown heat removal. The thermal-hydraulic behavior of the test bundles will be characterized for single-phase and two-phase conditions up to dryout. The influence of interassembly flow redistribution including transients from forced- to natural-convection conditions will be investigated during testing.« less

Mesoporous aluminosilicate glasses: Potential materials for dye removal from wastewater effluents

NASA Astrophysics Data System (ADS)

Almeida, Flavio P.; Botelho, Moema B. S.; Doerenkamp, Carsten; Kessler, Elizaveta; Ferrari, Cynthia R.; Eckert, Hellmut; de Camargo, Andrea S. S.

2017-09-01

Mesoporous amorphous sodium-aluminosilicate host matrices of composition Si1-xAlxNaxO2, 0.1 ≤ x ≤ 0.33, obtained by sol-gel methodology, have been used as sequestrating agents for the cationic dye Rhodamine 6 G (Rh6G) in solution. Favorable adsorption kinetics and a wide pH working range (4-10) as well as high sorption capacities for Rh6G render these materials potentially useful reagents for effective dye removal from wastewaters. While the experimentally realized sorption capacities fall significantly below the theoretical limits, used materials can be thermally re-cycled by pyrolizing the sequestrated dye molecules. Solid state NMR and BET measurements show that this process occurs under preservation of the materials' structural integrity, allowing it to be re-used multiple times.

Determination of residual cell culture media components by MEKC.

PubMed

Zhang, Junge; Chakraborty, Utpal; Foley, Joe P

2009-11-01

Folic acid, hypoxanthine, mycophenolic acid, nicotinic acid, riboflavin, and xanthine are widely used as cell culture media components in monoclonal antibody manufacturing. These components are subsequently removed during the downstream purification processes. This article describes a single MEKC method that can simultaneously determine all the listed compounds with acceptable LOD and LOQ. All the analytes were successfully separated by MEKC using running buffer containing 40 mM SDS, 20 mM sodium phosphate, and 20 mM sodium borate at pH 9.0. The MEKC method was compared to the corresponding CZE method using the same running buffer containing no SDS. The effect of SDS concentration on separation, the pH of the running buffer, and the detection wavelength were studied and optimal MEKC conditions were established. Good linearity was obtained with correlation coefficients of more than 0.99 for all analytes. Specificity, accuracy, and precision were also evaluated. The recovery was in the range of 89-112%. The precision results were in the range of 1.7-4.8%. The experimentally determined data demonstrated that the MEKC method is applicable to the determination of the six analytes in in-process samples from monoclonal antibody manufacturing processes.

Anammox moving bed biofilm reactor pilot at the 26th Ward wastewater treatment plants in Brooklyn, New York: start-up, biofilm population diversity and performance optimization.

PubMed

Mehrdad, M; Park, H; Ramalingam, K; Fillos, J; Beckmann, K; Deur, A; Chandran, K

2014-01-01

New York City Environmental Protection in conjunction with City College of New York assessed the application of the anammox process in the reject water treatment using a moving bed biofilm reactor (MBBR) located at the 26th Ward wastewater treatment plant, in Brooklyn, NY. The single-stage nitritation/anammox MBBR was seeded with activated sludge and consequently was enriched with its own 'homegrown' anammox bacteria (AMX). Objectives of this study included collection of additional process kinetic and operating data and assessment of the effect of nitrogen loading rates on process performance. The initial target total inorganic nitrogen removal of 70% was limited by the low alkalinity concentration available in the influent reject water. Higher removals were achieved after supplementing the alkalinity by adding sodium hydroxide. Throughout startup and process optimization, quantitative real-time polymerase chain reaction (qPCR) analyses were used for monitoring the relevant species enriched in the biofilm and in the suspension. Maximum nitrogen removal rate was achieved by stimulating the growth of a thick biofilm on the carriers, and controlling the concentration of dissolved oxygen in the bulk flow and the nitrogen loading rates per surface area; all three appear to have contributed in suppressing nitrite-oxidizing bacteria activity while enriching AMX density within the biofilm.

Richter and Sodium Appetite: from adrenalectomy to molecular biology

PubMed Central

Krause, Eric G.; Sakai, Randall R.

2007-01-01

Nearly three-quarters of a century ago, Curt Richter removed the adrenal glands from rats and noted that the animal's vitality was dependent on its increased consumption of sodium chloride. In doing so, Richter revealed an innate behavioral mechanism that serves to maintain the hydromineral balance of an animal faced with sodium deficit. This experiment and others like it, led to the development of a field of research devoted to the investigation of salt appetite. The following is a discussion of how Richter's initial observations gave birth to an evolving field that incorporates multiple approaches to examine the drive to consume sodium. PMID:17561308

Research on dispose of wastewater from printing and dyeing by CWF combined with Iron-carbon Microelectrolysis

NASA Astrophysics Data System (ADS)

Chen, Xin; Ye, Tingjin; Xu, Zizhen; Chen, Xiaogang; Shi, Liang; He, Lingfeng; Zhang, Yongli

2018-03-01

The carboxymethylchitosan cladding coal ash (CWF) was oxidized by the high temperature using coal ash and sodium carboxymethyl chitosan as raw and processed material for treatment of simulated and actual printing and dyeing wastewater over iron-carbon micro-electrolysis. The results on pH and CWF dosage for effluent dispose were evaluated by the decolorization rate, COD removal efficiency and turbidity removal rate. The experimental results indicated that the decolorization rate was first augmented and then declined with the increase of pH, and attained a peak value when pH was at 5-6. The COD removal efficiency augmented with the augmented of pH, and attained a peak value when pH was 6-7. The turbidity removal rate was first increases and afterwards decreases with the augment of pH, and attained a peak value when pH was at 5-6. Furthermore, the optimum pH for the treatment of simulated dyeing wastewater was 6 over iron-carbon micro-electrolysis, which indicated that the appropriate pH can promote the degradation of wastewater.

Effect of aquatine endodontic cleanser on smear layer removal in the root canals of ex vivo human teeth

PubMed Central

GARCIA, Faustino; MURRAY, Peter E.; GARCIA-GODOY, Franklin; NAMEROW, Kenneth N.

2010-01-01

Objectives The purpose of this study was to measure and compare the root canal cleanliness and smear layer removal effectiveness of Aquatine Endodontic Cleanser (Aquatine EC) when used as an endodontic irrigating solution in comparison with 6% sodium hypochlorite (NaOCl). Material and Methods Forty-five human teeth were randomly allocated to five treatment groups; the pulp chamber was accessed, cleaned, and shaped by using ProTaper and ProFile rotary instrumentation to an ISO size #40. The teeth were then processed for scanning electron microscopy, and the root canal cleanliness and removal of smear layer were examined. Results The most effective removal of smear layer occurred with Aquatine EC and NaOCl, both with a rinse of EDTA. Conclusions Aquatine EC appears to be the first hypochlorous acid approved by the FDA to be a possible alternative to the use of NaOCl as an intracanal irrigant. Further research is needed to identify safer and more effective alternatives to the use of NaOCl irrigation in endodontics. PMID:20835577

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

Rajamani, S.

The leather industry is an important export-oriented industry in India, with more than 3,000 tanneries located in different clusters. Sodium sulfide, a toxic chemical, is used in large quantities to remove hair and excess flesh from hides and skins. Most of the sodium sulfide used in the process is discharged as waste in the effluent, which causes serious environmental problems. Reduction of sulfide in the effluent is generally achieved by means of chemicals in the pretreatment system, which involves aerobic mixing using large amounts of chemicals and high energy, and generating large volumes of sludge. A simple biotechnological system thatmore » uses the residual biosludge from the secondary settling tank was developed, and the commercial-scale application established that more than 90% of the sulfide could be reduced in the primary treatment system. In addition to the reduction of sulfide, foul smells, BOD and COD are reduced to a considerable level. 3 refs., 2 figs., 1 tab.« less

Mechanisms for sodium insertion in carbon materials

NASA Astrophysics Data System (ADS)

Stevens, David Andrew

2000-12-01

This thesis details the mechanisms for sodium insertion into different carbons using both electrochemical and vapour techniques. Room temperature electrochemical measurements were completed to examine the insertion and removal of sodium from soft (graphitizable) and nanoporous hard (non-graphitizable) carbons prepared by the heat treatment of organic precursors to a range of temperatures. The mechanisms identified from these studies were further investigated through a series of in situ x-ray scattering studies on operating electrochemical cells. The results obtained were then compared with x-ray scattering measurements on carbons after exposure to sodium vapour at 890C. This work is primarily driven by the aluminium industry's need to understand how sodium insertion causes carbon cathode blocks in aluminium reduction cells to swell. The results obtained are also of relevance to the lithium-ion battery field as they help to verify mechanisms proposed in the literature for lithium insertion into carbon hosts. Some carbons were also identified that could accommodate large amounts of sodium, making them attractive candidates for anodes in rechargeable sodium ion batteries. For soft carbons, the results showed that both sodium and lithium insert between approximately parallel carbon layers along the sloping voltage region of the electrochemical curves, increasing the average interlayer spacing. The sodium and lithium capacities decreased with increasing carbon heat treatment temperature. For the soft carbons studied, the sodium capacity was found to be consistently lower than the lithium capacity, implying that some lithium-accessible sites were unavailable for sodium insertion. The electrochemical profiles for the hard carbons also contained capacity along a sloping voltage region and, as with the soft carbons, this was shown to result from the insertion of sodium and lithium between approximately parallel carbon layers. In contrast to the soft carbons, however, the electrochemical profiles for the hard carbons also exhibited significant capacity along low voltage plateaus at chemical potentials close to the chemical potential of the metal. An in situ small angle x-ray scattering experimental method was therefore developed to examine changes in scattering from the nanopores during sodium and lithium insertion/removal. The results from this technique clearly showed that the low voltage plateau capacity resulted from the insertion of sodium and lithium into nanopores in the carbon.

Removal of oxyfluorfen from ex-situ soil washing fluids using electrolysis with diamond anodes.

PubMed

dos Santos, Elisama Vieira; Sáez, Cristina; Martínez-Huitle, Carlos Alberto; Cañizares, Pablo; Rodrigo, Manuel Andres

2016-04-15

In this research, firstly, the treatment of soil spiked with oxyfluorfen was studied using a surfactant-aided soil-washing (SASW) process. After that, the electrochemical treatment of the washing liquid using boron doped diamond (BDD) anodes was performed. Results clearly demonstrate that SASW is a very efficient approach in the treatment of soil, removing the pesticide completely by using dosages below 5 g of sodium dodecyl sulfate (SDS) per Kg of soil. After that, complete mineralization of organic matter (oxyflourfen, SDS and by-products) was attained (100% of total organic carbon and chemical oxygen demand removals) when the washing liquids were electrolyzed using BDD anodes, but the removal rate depends on the size of the particles in solution. Electrolysis of soil washing fluids occurs via the reduction in size of micelles until their complete depletion. Lower concentrations of intermediates are produced (sulfate, chlorine, 4-(trifluoromethyl)-phenol and ortho-nitrophenol) during BDD-electrolyzes. Finally, it is important to indicate that, sulfate (coming from SDS) and chlorine (coming from oxyfluorfen) ions play an important role during the electrochemical organic matter removal. Copyright © 2016 Elsevier Ltd. All rights reserved.

An evaluation of the use of liquid calcium chloride to improve deicing and snow removal.

DOT National Transportation Integrated Search

1978-01-01

The Iowa method of spraying liquid calcium chloride onto sodium chloride applied in snow and ice removal operations was evaluated On four sections of highway in the Staunton District. From the relatively sparse data accumulated over three winters, it...

Simultaneous removal of nitrogen oxide/nitrogen dioxide/sulfur dioxide from gas streams by combined plasma scrubbing technology.

PubMed

Chang, Moo Been; Lee, How Ming; Wu, Feeling; Lai, Chi Ren

2004-08-01

Oxides of nitrogen (NOx) [nitrogen oxide (NO) + nitrogen dioxide (NO2)] and sulfur dioxide (SO2) are removed individually in traditional air pollution control technologies. This study proposes a combined plasma scrubbing (CPS) system for simultaneous removal of SO2 and NOx. CPS consists of a dielectric barrier discharge (DBD) and wet scrubbing in series. DBD is used to generate nonthermal plasmas for converting NO to NO2. The water-soluble NO2 then can be removed by wet scrubbing accompanied with SO2 removal. In this work, CPS was tested with simulated exhausts in the laboratory and with diesel-generator exhausts in the field. Experimental results indicate that DBD is very efficient in converting NO to NO2. More than 90% removal of NO, NOx, and SO2 can be simultaneously achieved with CPS. Both sodium sulfide (Na2S) and sodium sulfite (Na2SO3) scrubbing solutions are good for NO2 and SO2 absorption. Energy efficiencies for NOx and SO2 removal are 17 and 18 g/kWh, respectively. The technical feasibility of CPS for simultaneous removal of NO, NO2, and SO2 from gas streams is successfully demonstrated in this study. However, production of carbon monoxide as a side-product (approximately 100 ppm) is found and should be considered.

A comparative study of sodium dodecyl sulfate and freezing/thawing treatment on wheat starch: The role of water absorption.

PubMed

Tao, Han; Wang, Pei; Zhang, Bao; Wu, Fengfeng; Jin, Zhengyu; Xu, Xueming

2016-06-05

The effect of freezing on functionality of native and sodium dodecyl sulfate (SDS)-treated wheat starches was investigated, with the aim of understanding the role of water absorption during freezing process. SDS is one of most efficient detergents to remove non-starch components (such as proteins and lipids) for starches but does not cause any apparent damage on granular structure. Slow swelling could be converted to rapid swelling by SDS washing, indicating higher water absorption. Freezing process induced slight roughness on starch granules but the non-starch components content was little affected. Combined SDS+freezing treatment significantly decreased both amylose and proteins non-starch components contents, which was accompanied with high gelatinization temperatures, melting enthalpy, and pasting viscosities. A smaller bread specific volume was obtained from SDS+freezing-treated starches while the crumb firmness significantly increased (p<0.05). SDS mainly extracted the surface components from starch granules, leading to high water absorption and making granules sensitive to the freezing treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Selective oxidation of bromide in wastewater brines from hydraulic fracturing.

PubMed

Sun, Mei; Lowry, Gregory V; Gregory, Kelvin B

2013-07-01

Brines generated from oil and natural gas production, including flowback water and produced water from hydraulic fracturing of shale gas, may contain elevated concentrations of bromide (~1 g/L). Bromide is a broad concern due to the potential for forming brominated disinfection byproducts (DBPs) during drinking water treatment. Conventional treatment processes for bromide removal is costly and not specific. Selective bromide removal is technically challenging due to the presence of other ions in the brine, especially chloride as high as 30-200 g/L. This study evaluates the ability of solid graphite electrodes to selectively oxidize bromide to bromine in flowback water and produced water from a shale gas operation in Southwestern PA. The bromine can then be outgassed from the solution and recovered, as a process well understood in the bromine industry. This study revealed that bromide may be selectively and rapidly removed from oil and gas brines (~10 h(-1) m(-2) for produced water and ~60 h(-1) m(-2) for flowback water). The electrolysis occurs with a current efficiency between 60 and 90%, and the estimated energy cost is ~6 kJ/g Br. These data are similar to those for the chlor-alkali process that is commonly used for chlorine gas and sodium hydroxide production. The results demonstrate that bromide may be selectively removed from oil and gas brines to create an opportunity for environmental protection and resource recovery. Copyright © 2013 Elsevier Ltd. All rights reserved.

Laboratory scale studies on removal of chromium from industrial wastes.

PubMed

Baig, M A; Mir, Mohsin; Murtaza, Shazad; Bhatti, Zafar I

2003-05-01

Chromium being one of the major toxic pollutants is discharged from electroplating and chrome tanning processes and is also found in the effluents of dyes, paint pigments, manufacturing units etc. Chromium exists in aqueous systems in both trivalent (Cr(3+)) and hexavalent (Cr(6+)) forms. The hexavalent form is carcinogenic and toxic to aquatic life, whereas Cr(3+) is however comparatively less toxic. This study was undertaken to investigate the total chromium removal from industrial effluents by chemical means in order to achieve the Pakistan NEQS level of 1 mg/L by the methods of reduction and precipitation. The study was conducted in four phases. In phase I, the optimum pH and cost effective reducing agent among the four popular commercial chemicals was selected. As a result, pH of 2 was found to be most suitable and sodium meta bisulfate was found to be the most cost effective reducing agent respectively. Phase II showed that lower dose of sodium meta bisulfate was sufficient to obtain 100% efficiency in reducing Cr(6+) to Cr(3+), and it was noted that reaction time had no significance in the whole process. A design curve for reduction process was established which can act as a tool for treatment of industrial effluents. Phase III studies indicated the best pH was 8.5 for precipitation of Cr(3+) to chromium hydroxide by using lime. An efficiency of 100% was achievable and a settling time of 30 minutes produced clear effluent. Finally in Phase IV actual waste samples from chrome tanning and electroplating industries, when precipitated at pH of 12 gave 100% efficiency at a settling time of 30 minutes and confined that chemical means of reduction and precipitation is a feasible and viable solution for treating chromium wastes from industries.

Electrolytic process to produce sodium hypochlorite using sodium ion conductive ceramic membranes

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

Balagopal, Shekar; Malhotra, Vinod; Pendleton, Justin

An electrochemical process for the production of sodium hypochlorite is disclosed. The process may potentially be used to produce sodium hypochlorite from seawater or low purity un-softened or NaCl-based salt solutions. The process utilizes a sodium ion conductive ceramic membrane, such as membranes based on NASICON-type materials, in an electrolytic cell. In the process, water is reduced at a cathode to form hydroxyl ions and hydrogen gas. Chloride ions from a sodium chloride solution are oxidized in the anolyte compartment to produce chlorine gas which reacts with water to produce hypochlorous and hydrochloric acid. Sodium ions are transported from themore » anolyte compartment to the catholyte compartment across the sodium ion conductive ceramic membrane. Sodium hydroxide is transported from the catholyte compartment to the anolyte compartment to produce sodium hypochlorite within the anolyte compartment.« less

Adsorption isotherm, kinetic and mechanism of expanded graphite for sulfadiazine antibiotics removal from aqueous solutions.

PubMed

Zhang, Ling; Wang, Yong; Jin, SuWan; Lu, QunZan; Ji, Jiang

2017-10-01

The adsorption of sulfadiazine from water by expanded graphite (EG), a low cost and environmental-friendly adsorbent, was investigated. Several adsorption parameters (including the initial sulfadiazine concentration, contact time, pH of solution, ionic strength and temperature) were studied. Results of equilibrium experiments indicated that adsorption of sulfadiazine onto EG were better described by the Langmuir and Tempkin models than by the Freundlich model. The maximum adsorption capacity is calculated to be 16.586 mg/g at 298 K. The kinetic data were analyzed by pseudo-first-order, pseudo-second-order and intraparticle models. The results indicated that the adsorption process followed pseudo-second-order kinetics and may be controlled by two steps. Moreover, the pH significantly influenced the adsorption process, with the relatively high adsorption capacity at pH 2-10. The electrostatic and hydrophobic interactions are manifested to be two main mechanisms for sulfadiazine adsorption of EG. Meanwhile, the ionic concentration of Cl - slightly impacted the removal of sulfadiazine. Results of thermodynamics analysis showed spontaneous and exothermic nature of sulfadiazine adsorption on EG. In addition, regeneration experiments imply that the saturated EG could be reused for sulfadiazine removal by immersing sodium hydroxide.

Surface sodium lignosulphonate-immobilized sawdust particle as an efficient adsorbent for capturing Hg2+ from aqueous solution.

PubMed

Gao, Shan; Luo, Tiantian; Zhou, Qi; Luo, Wenjun; Li, Haifeng; Jing, Luru

2018-05-01

In this work, the soluble sodium lignosulphonate (LS Na ) molecules were successfully grafted onto the surface of pine sawdust (PSD) particles to obtain an efficient adsorbent (PSD-LS) for removing Hg 2+ from wastewater. In advance, the surface of sawdust particles were carboxymethylated by chloroacetic acid, the LS Na would be anchored on the surface by a heterogeneous esterification reaction occurred between the hydroxyl of LS Na and carboxyl on PSD surface. The resultant product (PSD-LS) exhibited a good adsorption performance for Hg 2+ with adsorption capacity up to 164.77 mg/g and it was characterized by scanning electron microscope (SEM), energy dispersive X-ray diffraction (EDX), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The effects of pH, contact time, adsorption temperature and initial concentration on the adsorption of Hg 2+ were investigated. Results showed that the pseudo-second-order kinetics and Langmuir isotherm model could describe the adsorption process better. In addition, the composite adsorbent has outstanding reusability with high and stable desorption rates under several continuous cycle. These findings suggested that PSD-LS was a potential adsorbent to remove hazardous metal ions from wastewater. Copyright © 2018 Elsevier Inc. All rights reserved.

Novel highly porous magnetic hydrogel beads composed of chitosan and sodium citrate: an effective adsorbent for the removal of heavy metals from aqueous solutions.

PubMed

Pu, Shengyan; Ma, Hui; Zinchenko, Anatoly; Chu, Wei

2017-07-01

This research focuses on the removal of heavy metal ions from aqueous solutions using magnetic chitosan hydrogel beads as a potential sorbent. Highly porous magnetic chitosan hydrogel (PMCH) beads were prepared by a combination of in situ co-precipitation and sodium citrate cross-linking. Fourier transform infrared spectroscopy indicated that the high sorption efficiency of metal cations is attributable to the hydroxyl, amino, and carboxyl groups in PMCH beads. Thermogravimetric analysis demonstrated that introducing Fe 3 O 4 nanoparticles increases the thermal stability of the adsorbent. Laser confocal microscopy revealed highly uniform porous structure of the resultant PMCH beads, which contained a high moisture content (93%). Transmission electron microscopy micrographs showed that the Fe 3 O 4 nanoparticles, with a mean diameter of 5 ± 2 nm, were well dispersed inside the chitosan beads. Batch adsorption experiments and adsorption kinetic analysis revealed that the adsorption process obeys a pseudo-second-order model. Isotherm data were satisfactorily described by the Langmuir equation, and the maximum adsorption capacity of the adsorbent was 84.02 mg/g. Energy-dispersive X-ray spectroscopy and X-ray photoelectron spectra analyses were performed to confirm the adsorption of Pb 2+ and to identify the adsorption mechanism.

The importance of the location of sodium chlorite application in a multipollutant flue gas cleaning system.

PubMed

Krzyzynska, Renata; Hutson, Nick D

2012-06-01

In this study, removing sulfur dioxide (SO2), nitrogen oxides (NO(x)), and mercury (Hg) from simulated flue gas was investigated in two laboratory-sized bubbling reactors that simulated an oxidizing reactor (where the NO and Hg(0) oxidation reactions are expected to occur) and a wet limestone scrubber, respectively. A sodium chlorite solution was used as the oxidizing agent. The sodium chlorite solution was an effective additive that enhanced the NO(x), Hg, and SO2 capture from the flue gas. Furthermore, it was discovered that the location of the sodium chlorite application (before, in, or after the wet scrubber) greatly influences which pollutants are removed and the amount removed. This effect is related to the chemical conditions (pH, absence/presence of particular gases) that are present at different positions throughout the flue gas cleaning system profile. The research results indicated that there is a potential to achieve nearly zero SO2, NO(x), and Hg emissions (complete SO2, NO, and Hg removals and -90% of NO(x) absorption from initial values of 1500 ppmv of SO2, 200 ppmv of NO(x), and 206 microg/m3 of Hg(0)) from the flue gas when sodium chlorite was applied before the wet limestone scrubber. However applying the oxidizer after the wet limestone scrubber was the most effective configuration for Hg and NO(x) control for extremely low chlorite concentrations (below 0.002 M) and therefore appears to be the best configuration for Hg control or as an additional step in NO(x) recleaning (after other NO(x) control facilities). The multipollutant scrubber, into which the chlorite was injected simultaneously with the calcium carbonate slurry, appeared to be the least expensive solution (when consider only capital cost), but exhibited the lowest NO(x) absorption at -50%. The bench-scale test results presented can be used to develop performance predictions for a full- or pilot-scale multipollutant flue gas cleaning system equipped with wet flue gas desulfurization scrubber.

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

Soldaini, Michel

The first heading of your manuscript must be 'Introduction'. Phenix is the only remaining French fast breeder reactor after the shutdown of Superphenix (1999) and Rapsodie (1983). Phenix is located inside the Marcoule nuclear site along the Rhone river near Bagnols-sur-Ceze in southeastern France. Phenix is one of the facilities belonging the French Atomic Energy Commission (CEA) on the Marcoule site. It is a fast breeder reactor (FBR) developed at the end of the 1960's. that has been in operation since 1973 and was connected to the power grid in 1974. It is a second generation prototype developed while themore » first generation FBR, Rapsodie, was still in operation. Phenix is a 250 electrical MW power plant. During the first 20 years of operation, its main aim was to demonstrate the viability of sodium-cooled FBRs. Since the 1991 radioactive waste management act, Phenix has become an irradiation tool for the actinide transmutation program. To extend its operating life for 6 additional cycles, it was necessary to refurbish the plant; this involved major work performed from 1999 to 2003 at a total cost of about 250 M??. Today, with a realistic expectation, the final shutdown is planned for the beginning of 2009. The main objective of the Phenix dismantling project is to eliminate all the process equipment and clean all the building to remove all the radioactive zones. To reach this objective, three main hazards must be eliminated: Fuel (criticality hazard), Sodium, Radioactive equipment. The complexity of decommissioning a facility such as Phenix is increased by: - the lack of storage facility for high radioactive material, - the decision to treat all the radioactive sodium and sodium waste inside the plant, - the very high irradiation of the core structures due to the presence of cobalt alloys. On the other hand, Phenix plant is still under operating with a qualified staff and the radioactivity coming from structural activation is well known. After the final shutdown, the first operations will be conducted by the same staff under the same safety report. Another interesting fact is that the decommissioning funds project exist and are available. The CEA decided to begin the dismantling phase without waiting because after a period of decay it is not really cheaper or easier to work. This approach needs interim storage facilities not long after the final shutdown. For the low- and intermediate-level radioactive waste there are national storage centers but for the high-level wastes, each operator must manage its waste until a suitable disposal site is available. At Marcoule a new storage facility is now being designed and scheduled to begin operating after 2013-2014. After removal of the fuel and core elements, the primary sodium will be drained and eliminated by a carbonation process. To ensure biological shielding, the reference scenario calls for filling the primary vessel with water. The most radioactive structures (dia-grid and core support) will be cut up with remote tools, after which the rest of the structure will be cut up manually. Phenix contains about 1450 metric tons of sodium. The CEA initially planned to build ATENA, a new facility for all radioactive sodium waste from R and D and FBR facilities. For various reasons, but mainly to save money, the CEA decided to treat all radioactive sodium and sodium waste in the framework of the Phenix dismantling project. There are no real difficulties in the dismantling schedule because of the advanced state of development of the processes selected for the ATENA project. Because of the knowledge already obtained, the issues concern project management, waste management and human resources reduction more than technical 0014challe.« less

Precipitation of ammonium from concentrated industrial wastes as struvite: a search for the optimal reagents.

PubMed

Borojovich, Eitan J C; Münster, Meshulam; Rafailov, Gennady; Porat, Ze'ev

2010-07-01

Precipitation of struvite (MgNH4PO4) is a known process for purification of wastewater from high concentrations of ammonium. The optimal conditions for precipitation are basic pH (around 9) and sufficient concentrations of magnesium and phosphate ions. In this work, we accomplished efficient precipitation of ammonium from concentrated industrial waste stream by using magnesium oxide (MgO) both as a source of magnesium ions and as a base. Best results were obtained with technical-grade MgO, which provided 99% removal of ammonium. Moreover, ammonium removal occurred already at pH 7, and the residual ammonium concentration (50 mg/L) remained constant upon addition of more MgO without rising again, as occurs with sodium hydroxide (NaOH). This process may have two other advantages; it also can be relevant for the problem of uncontrolled precipitation of struvite in the supernatant of anaerobic sludge treatment plants, and the precipitate can be used as a fertilizer.

Feasibility study of NaOH regeneration in acid gas removal unit using membrane electrolysis

NASA Astrophysics Data System (ADS)

Taufany, Fadlilatul; Pratama, Alvian; Romzuddin, Muhammad

2017-05-01

The world's energy demand is increasing with the development of human civilization. Due to limited energy resource, after 2020 fossil fuels thus is predicted will be replaced by renewable resources. Taking an example, one of the potential renewable energy to be considered is biogas, as its high content of methane, which can be produced via the fermentation process of the organic compounds under controlled anaerobic environment by utilizing the methanogen bacteria. However, prior the further use, this biogas must be purified from its impurities contents, i.e. acid gas of CO2 and H2S, up to 4% and 16 ppmv, respectively, in the acid gas removal unit. This such of purification efforts, will significantly increase the higher heating value of biogas, approximately from 600 to 900 Btu/Scf. During the purification process in this acid gas removal unit, NaOH solution is used as a liquid absorbent to reduce those acid gases content, in which the by-product of alkali salt (brine) was produced as waste. Here we report the feasibility study of the NaOH regeneration process in acid gas removal unit via membrane electrolysis technology, in which both the technical and economic aspects are taken account. To be precise in procedure, the anode semi-cell was filled with the brine solution, while the cathode semi-cell was filled with demineralized water, and those electrodes were separated by the cation exchange membrane. Furthermore, the applied potential was varied ranging from 5, 10, 15 and to 20 V, while the concentration of KCl electrolyte solutions were varied ranging from 0.01, 0.05, 0.1, and to 0.03 M. This study was conducted under controlled temperatures of 30 and 50 °C. Here we found that the % sodium recovery was increased along with the applied potential, temperature, and the decrease in KCl electrolyte concentration. We found that the best results, by means of the highest % sodium recovery, i.e. 97.26 %, was achieved under the experimental condition of temperature at 30 °C, applied potential at 15 V, and KCl electrolyte concentration at 0.01 M. At such electrolysis condition, the energy efficiency was calculated to be 0,009 M-NaOH/Wh, or was equal to operating cost at 0.04/kg-NaOH.

Removal of phenol by activated alumina bed in pulsed high-voltage electric field.

PubMed

Zhu, Li-nan; Ma, Jun; Yang, Shi-dong

2007-01-01

A new process for removing the pollutants in aqueous solution-activated alumina bed in pulsed high-voltage electric field was investigated for the removal of phenol under different conditions. The experimental results indicated the increase in removal rate with increasing applied voltage, increasing pH value of the solution, aeration, and adding Fe2+. The removal rate of phenol could reach 72.1% when air aeration flow rate was 1200 ml/min, and 88.2% when 0.05 mmol/L Fe2+ was added into the solution under the conditions of applied voltage 25 kV, initial phenol concentration of 5 mg/L, and initial pH value 5.5. The addition of sodium carbonate reduced the phenol removal rate. In the pulsed high-voltage electric field, local discharge occurred at the surface of activated alumina, which promoted phenol degradation in the thin water film. At the same time, the space-time distribution of gas-liquid phases was more uniform and the contact areas of the activated species generated from the discharge and the pollutant molecules were much wider due to the effect of the activated alumina bed. The synthetical effects of the pulsed high-voltage electric field and the activated alumina particles accelerated phenol degradation.

The secretion of alkali metal ions by the perfused cat pancreas as influenced by the composition and osmolality of the external environment and by inhibitors of metabolism and Na+, K+-ATPase activity

PubMed Central

Case, R. M.; Scratcherd, T.

1974-01-01

1. The secretion of sodium, potassium and lithium has been studied in the isolated cat pancreas, perfused with bicarbonate buffered saline solutions of varying composition and osmolality, and stimulated maximally with secretin. 2. Under isosmolal conditions, when perfusate sodium chloride was replaced by sucrose, sodium secretion and potassium secretion were directly related to perfusate sodium concentration, [Na]p. 3. When osmolality was varied by increasing or decreasing perfusate sodium chloride concentration, the secretion of sodium and of potassium were maximal at [Na]p of about 120 and 80 mM respectively. 4. At a given [Na]p, sodium secretion was greater under hypo-osmolal conditions than under isosmolal conditions. 5. When potassium concentration was varied over the range 0-130 mM under isosmolal conditions, by adjusting perfusate NaCl concentration, the secretion of potassium and of sodium were maximal at [K]p of about 50 and 10 mM respectively. Water flux was maximal at a [K]p of 10-15 mM. The concentration of potassium in the secretion was almost identical with that in the perfusate over the whole concentration range. 6. Replacement of perfusate sodium by lithium reduced the volume of secretion, though a small secretion was maintained even in the complete absence of sodium. The concentration of lithium in the secretion was generally slightly greater than that in the perfusate. 7. Omission of potassium from the perfusate reduced secretion by about 65%. Rubidium was a complete substitute for potassium; caesium was not. 8. Energy for secretion is derived largely from oxidative phosphorylation. Secretion was reduced by more than 90% under anaerobic conditions and in the presence of dinitrophenol or cyanide. Removal of glucose from the perfusate reduced secretion by more than 50% within 30 min; lactate was a complete substitute for glucose. 9. Ouabain, ethacrinic acid and frusimide, known inhibitors of Na+, K+-ATPase activity, all inhibited pancreatic electrolyte secretion. 10. The observations are interpreted with reference to the nature of active transport processes involved in pancreatic electrolyte secretion. PMID:4281836

Elimination of Isoxazolyl-Penicillins antibiotics in waters by the ligninolytic native Colombian strain Leptosphaerulina sp. considerations on biodegradation process and antimicrobial activity removal.

PubMed

Copete-Pertuz, Ledys S; Plácido, Jersson; Serna-Galvis, Efraím A; Torres-Palma, Ricardo A; Mora, Amanda

2018-07-15

In this work, Leptosphaerulina sp. (a Colombian native fungus) significantly removed three Isoxazolyl-Penicillin antibiotics (IP): oxacillin (OXA, 16000 μg L -1 ), cloxacillin (CLX, 17500 μg L -1 ) and dicloxacillin (DCX, 19000 μg L -1 ) from water. The biological treatment was performed at pH 5.6, 28 °C, and 160 rpm for 15 days. The biotransformation process and lack of toxicity of the final solutions (antibacterial activity (AA) and cytotoxicity) were tested. The role of enzymes in IP removal was analysed through in vitro studies with enzymatic extracts (crude and pre-purified) from Leptosphaerulina sp., commercial enzymes and enzymatic inhibitors. Furthermore, the applicability of mycoremediation process to a complex matrix (simulated hospital wastewater) was evaluated. IP were considerably abated by the fungus, OXA was the fastest degraded (day 6), followed by CLX (day 7) and DCX (day 8). Antibiotics biodegradation was associated to laccase and versatile peroxidase action. Assays using commercial enzymes (i.e. laccase from Trametes versicolor and horseradish peroxidase) and inhibitors (EDTA, NaCl, sodium acetate, manganese (II) ions) confirmed the significant role of enzymatic transformation. Whereas, biomass sorption was not an important process in the antibiotics elimination. Evaluation of AA against Staphylococcus aureus ATCC 6538 revealed that Leptosphaerulina sp. also eliminated the AA. In addition, the cytotoxicity assay (MTT) on the HepG2 cell line demonstrated that the IP final solutions were non-toxic. Finally, Leptosphaerulina sp. eliminated OXA and its AA from synthetic hospital wastewater at 6 days. All these results evidenced the potential of Leptosphaerulina sp. mycoremediation as a novel environmentally friendly process for the removal of IP from aqueous systems. Copyright © 2018 Elsevier B.V. All rights reserved.

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

Not Available

This volume contains the interim change notice for physical testing. Covered are: properties of solutions, slurries, and sludges; rheological measurement with cone/plate viscometer; % solids determination; particle size distribution by laser scanning; penetration resistance of radioactive waste; operation of differential scanning calorimeter, thermogravimetric analyzer, and high temperature DTA and DSC; sodium rod for sodium bonded fuel; filling SP-100 fuel capsules; sodium filling of BEATRIX-II type capsules; removal of alkali metals with ammonia; specific gravity of highly radioactive solutions; bulk density of radioactive granular solids; purification of Li by hot gettering/filtration; and Li filling of MOTA capsules.

A cluster ion chemistry for the mesospheric sodium layer

NASA Technical Reports Server (NTRS)

Richter, E. S.; Sechrist, C. F., Jr.

1979-01-01

A cluster ion chemistry for sodium is developed which relates the Na(+) profile to the Na profile using reactions involving Na(+).N2, Na(+).CO2, and Na(+).H2O. Removal of sodium from the mesosphere is accomplished by the formation of higher order clusters of the form Na(+).(H2O)n which presumably precipitate to the lower atmosphere. This sink is most effective in the 80-85 km altitude range. The chemical equilibrium model is applied to experimental observations of the Na and Na(+) layers.

Fast reactor safety and related physics. Volume IV. Phenomenology

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

Not Available

1976-01-01

Separate abstracts are included for 58 papers concerning single-phase flow and sodium boiling; sodium boiling and subassembly flow blockages; transient-overpower and loss-of-flow experiments; fuel and cladding behavior and relocation; fuel and cladding freezing; molten-fuel-coolant interaction; aerosols and fission product release, and post-accident heat removal. Thirteen papers have been perivously abstracted and included in ERA.

Comparison of sodium carbonate-oxygen and sodium hydroxide-oxygen pretreatments on the chemical composition and enzymatic saccharification of wheat straw.

PubMed

Geng, Wenhui; Huang, Ting; Jin, Yongcan; Song, Junlong; Chang, Hou-Min; Jameel, Hasan

2014-06-01

Pretreatment of wheat straw with a combination of sodium carbonate (Na2CO3) or sodium hydroxide (NaOH) with oxygen (O2) 0.5MPa was evaluated for its delignification ability at relatively low temperature 110°C and for its effect on enzymatic hydrolysis efficiency. In the pretreatment, the increase of alkali charge (as Na2O) up to 12% for Na2CO3 and 6% for NaOH, respectively, resulted in enhancement of lignin removal, but did not significantly degrade cellulose and hemicellulose. When the pretreated solid was hydrolyzed with a mixture of cellulases and hemicellulases, the sugar yield increased rapidly with the lignin removal during the pretreatment. A total sugar yield based on dry matter of raw material, 63.8% for Na2CO3-O2 and 71.9% for NaOH-O2 was achieved under a cellulase loading of 20FPU/g-cellulose. The delignification efficiency and total sugar yield from enzymatic hydrolysis were comparable to the previously reported results at much higher temperature without oxygen. Copyright © 2014 Elsevier Ltd. All rights reserved.

Tetrapentylammonium block of chloramine-T and veratridine modified rat brain type IIA sodium channels

PubMed Central

Ghatpande, A S; Rao, S; Sikdar, S K

2001-01-01

Tetrapentylammonium (TPeA) block of rat brain type IIA sodium channel α subunit was studied using whole cell patch clamp. Results indicate that TPeA blocks the inactivating brain sodium channel in a potential and use-dependent manner similar to that of the cardiac sodium channel. Removal of inactivation using chloramine-T (CT) unmasks a time-dependent block by TPeA consistent with slow blocking kinetics. On the other hand, no time dependence is observed when inactivation is abolished by modification with veratridine. TPeA does not bind in a potential-dependent fashion to veratridine-modified channels and does not significantly affect gating of veratridine-modified channels suggesting that high affinity binding of TPeA to the brain sodium channel is lost after veratridine modification. PMID:11309247

Sodium, phosphate, glucose, bicarbonate, and alanine interactions in the isolated proximal convoluted tubule of the rabbit kidney.

PubMed

Dennis, V W; Brazy, P C

1978-08-01

Interactions among the transport systems involved with sodium, bicarbonate, glucose, phosphate, and alanine absorption in isolated segments of the rabbit proximal convoluted tubule were examined with radioisotopic techniques to measure glucose, phosphate, and fluid absorption rates. The composition of the perfusate and bath varied from normal, physiological fluids to fluids deficient in a single solute. The deletion of glucose from the perfusate increased the lumen-to-bath flux of phosphate from 5.51 +/- 1.15 to 8.32 +/- 1.34 pmol/mm-min (P less than 0.01). Similar changes occurred when glucose transport was inhibited by phlorizin 10 micron in the perfusate, The deletion of alanine from the perfusate increased the lumen-to-bath flux of phosphate from 6.55 +/- 1.08 to 9.00 +/- 1.30 pmol/mm-min (P less than 0.01) but did not affect glucose transport significantly, 80.1 +/- 10.1 vs. 72.5 +/- 5.4 pmol/mm-min. Replacement of intraluminal sodium with choline, elimination of potassium from the bath, and removal of bicarbonate from the lumen and bath each reduced glucose, phosphate, and fluid absorption. These data indicate that the proximal absorptive processes for glucose and for phosphate include elements that are dependent upon some function of sodium transport. Additionally, the effects on phosphate transport of deleting glucose or alanine occur independent of any changes in net sodium transport and are opposite the effects of deleting bicarbonate. These differences may relate to the observations that the transport of glucose and alanine is electrogenic while that of bicarbonate is not. Regardless of possible mechanisms, the data demonstrate that important changes in the absorption rates of different solutes handled significantly by the proximal convoluted tubule may occur in response to changes in specific components of proximal sodium transport.

Cardiac basal metabolism: energetic cost of calcium withdrawal in the adult rat heart.

PubMed

Bonazzola, P; Takara, D

2010-07-01

Cardiac basal metabolism upon extracellular calcium removal and its relationship with intracellular sodium and calcium homeostasis was evaluated. A mechano-calorimetric technique was used that allowed the simultaneous and continuous measurement of both heat rate and resting pressure in arterially perfused quiescent adult rat hearts. Using pharmacological tools, the possible underlying mechanisms related to sodium and calcium movements were investigated. Resting heat rate (expressed in mW g(-1)(dry wt)) increased upon calcium withdrawal (+4.4 +/- 0.2). This response was: (1) unaffected by the presence of tetrodotoxin (+4.3 +/- 0.6), (2) fully blocked by both, the decrease in extracellular sodium concentration and the increase in extracellular magnesium concentration, (3) partially blocked by the presence of either nifedipine (+2.8 +/- 0.4), KB-R7943 (KBR; +2.5 +/- 0.2), clonazepam (CLO; +3.1 +/- 0.3) or EGTA (+1.9 +/- 0.3). The steady heat rate under Ca(2+)-free conditions was partially reduced by the addition of Ru360 (-1.1 +/- 0.2) but not CLO in the presence of EGTA, KBR or Ru360. Energy expenditure for resting state maintenance upon calcium withdrawal depends on the intracellular rise in both sodium and calcium. Our data are consistent with a mitochondrial Ca(2+) cycling, not detectable under normal calcium diastolic levels. The experimental condition here analysed, partially simulates findings reported under certain pathological situations including heart failure in which mildly increased levels of both diastolic sodium and calcium have also been found. Therefore, under such pathological conditions, hearts should distract chemical energy to fuel processes associated with sodium and calcium handling, making more expensive the maintenance of their functions.

Sodium accumulation at potential-induced degradation shunted areas in polycrystalline silicon modules

DOE PAGES

Harvey, Steven P.; Aguiar, Jeffery A.; Hacke, Peter; ...

2016-09-19

Here, we investigated potential-induced degradation (PID) in silicon mini-modules that were subjected to accelerated stressing to induce PID conditions. Shunted areas on the cells were identified with photoluminescence and dark lock-in thermography (DLIT) imaging. The identical shunted areas were then analyzed via time-of-flight secondary-ion mass spectrometry (TOFSIMS) imaging, 3-D tomography, and high-resolution transmission electron microscopy. The TOF-SIMS imaging indicates a high concentration of sodium in the shunted areas, and 3-D tomography reveals that the sodium extends more than 2 um from the surface below shunted regions. Transmission electron microscopy investigation reveals that a stacking fault is present at an areamore » identified as shunted by DLIT imaging. After the removal of surface sodium, tomography reveals persistent sodium present around the junction depth of 300 nm and a drastic difference in sodium content at the junction when comparing shunted and nonshunted regions.« less

Safe disposal of radioactive iodide ions from solutions by Ag2O grafted sodium niobate nanofibers.

PubMed

Mu, Wanjun; Li, Xingliang; Liu, Guoping; Yu, Qianhong; Xie, Xiang; Wei, Hongyuan; Jian, Yuan

2016-01-14

Radioactive iodine isotopes are released into the environment by the nuclear industry and medical research institutions using radioactive materials, and have negative effects on organisms living within the ecosystem. Thus, safe disposal of radioactive iodine is necessary and crucial. For this reason, the uptake of iodide ions was investigated in Ag2O nanocrystal grafted sodium niobate nanofibers, which were prepared by forming a well-matched phase coherent interface between them. The resulting composite was applied as an efficient adsorbent for I(-) anions by forming an AgI precipitate, which also remained firmly attached to the substrates. Due to their one-dimensional morphology, the new adsorbents can be easily dispersed in liquids and readily separated after purification. This significantly enhances the adsorption efficiency and reduces the separation costs. The change in structure from the pristine sodium niobate to Ag2O anchored sodium niobate and to the used adsorbent was examined by using various characterization techniques. The effects of Ag(+) concentration, pH, equilibration time, ionic strength and competing ions on the iodide ion removal ability of the composite were studied. The Ag2O nanocrystal grafted sodium niobate adsorbent showed a high adsorption capacity and excellent selectivity for I(-) anions in basic solutions. Our results are useful for the further development of improved adsorbents for removing I(-) anions from basic wastewater.

Concentration and time-dependent effect of initial sodium hypochlorite on the ability of QMix and ethylenediaminetetraacetic acid to remove smear layer.

PubMed

Aksel, Hacer; Serper, Ahmet

2017-01-01

The aim of this study was to compare the ability of 17% ethylenediaminetetraacetic acid (EDTA) and QMix with different concentrations and time exposures of initial sodium hypochlorite (NaOCl) to remove the smear layer from the root canals. Eighty maxillary central incisors were used. After instrumentation, the teeth were divided into eight experimental groups according to the initial and final rinse. About 2.5% and 5% NaOCl were used during instrumentation and for 1 or 3 min was used as postinstrumentation initial irrigants, and 17% EDTA and QMix used as final irrigants. The apical and middle parts of the specimens were observed by scanning electron microscope. Data were analyzed using the Kruskal-Wallis, Mann-Whitney, and Friedman's test. Regardless of the type of final irrigant, QMix allowed more smear layer removal than EDTA after using 5% initial NaOCl for 3 min. In the apical part of the root canal walls, the smear layer was not completely removed. QMix and EDTA were similarly effective in smear layer removal at the middle parts of the root canal regardless of the concentration and time exposure of initial NaOCl, while none of the irrigation protocols was able to remove smear layer at the apical parts.

Evaluation of photosynthetic efficacy and CO2 removal of microalgae grown in an enriched bicarbonate medium.

PubMed

Abinandan, S; Shanthakumar, S

2016-06-01

Bicarbonate species in the aqueous phase is the primary source for CO 2 for the growth of microalgae. The potential of carbon dioxide (CO 2 ) fixation by Chlorella pyrenoidosa in enriched bicarbonate medium was evaluated. In the present study, effects of parameters such as pH, sodium bicarbonate concentration and inoculum size were assessed for the removal of CO 2 by C. pyrenoidosa under mixotrophic condition. Central composite design tool from response surface methodology was used to validate statistical methods in order to study the influence of these parameters. The obtained results reveal that the maximum removal of CO 2 was attained at pH 8 with sodium bicarbonate concentration of 3.33 g/l, and inoculum size of 30 %. The experimental results were statistically significant with R 2 value of 0.9527 and 0.960 for CO 2 removal and accumulation of chlorophyll content, respectively. Among the various interactions, interactive effects between the parameters pH and inoculum size was statistically significant (P < 0.05) for CO 2 removal and chlorophyll accumulation. Based on the studies, the application of C. pyrenoidosa as a potential source for carbon dioxide removal at alkaline pH from bicarbonate source is highlighted.

Integration of chemical scrubber with sodium hypochlorite and surfactant for removal of hydrocarbons in cooking oil fume.

PubMed

Cheng, Hsin-Han; Hsieh, Chu-Chin

2010-10-15

There are many types of technologies to control cooking oil fumes (COFs), but current typical technologies, such as electrostatic precipitator, conventional scrubber, catalyst, or condenser, are unable to efficiently remove the odorous materials present in COFs which are the primary cause of odor-complaint cases. There is also a lack of information about using sodium hypochlorite (NaOCl) and surfactants to remove contaminants in COFs, and previous studies lack on-site investigations in restaurants. This study presents a chemical scrubber integrated with an automatic control system (ACS) to treat hydrocarbons (HCs) in COFs, and to monitor non-methane HCs (NMHC) and odor as indicators for its efficiency evaluation. The chemical scrubber effectively treats hydrophobic substances in COFs by combining surfactant and NaOCl under optimal operational conditions with NHMC removal efficiency as high as 85%. The mass transfer coefficient (K(L)a) of NMHC was enhanced by 50% under the NaOCl and surfactant conditions, as compared to typical wet scrubber. Further, this study establishes the fuzzy equations of the ACS, including the relationship between the removal efficiency and K(L)a, liquid/gas ratio, pH and C(NaOCl). 2010 Elsevier B.V. All rights reserved.

Improvement of organoleptic quality of retted cassava products by alkali pretreatment of roots and addition of sodium nitrate during retting.

PubMed

Ogbo, Frank C

2003-12-15

Alkali pretreatment of cassava roots before retting and addition of sodium nitrate during retting were used to manipulate the metabolism of microorganisms involved in cassava (Manihot esculenta Crantz) retting, as a method for removing the characteristic offensive odour of retted cassava products. Odour was assessed by organoleptic methods. The characteristics of fermentation of cassava by the traditional method (control) were as follows; aerobic mesophilic count (APC) on nutrient agar (NA) at 30 degrees C/48 h, attained a maximum of 2.3 x 10(7)/ml retting juice while counts on de Man Rogosa and Sharpe agar (MRS) at 30 degrees C/48 h were 1.6 x 10(8)/ml. Maximum titrable acidity was 0.062% lactic acid by weight of retting juice. Cassava was retted in 3 days and the product exhibited characteristic offensive odour. Addition of NaNO3 into retting water effectively removed odour at a concentration of 0.3 g/l. Maximum APC on NA/30 degrees C/48 h was 6.8 x 10(6)/ml. Counts on MRS/30 degrees C/48 h exceeded 2.4 x 10(9)/ml. Retting was complete in 3 days with a final titrable acidity of 0.068% of retting juice. Removal of odour likely resulted from selection of homo-fermentative lactic acid bacteria, thus producing mostly odourless lactic acid. Alkali pretreatment of roots before retting was efficacious in removing odour at a concentration of 10 g/l for 30 min. This fermentation was characterized by APC on NA/30 degrees C/48 h of 5.4 x 10(6)/ml; MRS/30 degrees C/48 h reached a maximum of only 10 x 10(4)/ml and correspondingly low titrable acidity of 0.003%. Low counts of lactic acid bacteria correlate well with the absence of odour in this sample. Both treatments did not adversely affect the detoxification process, yielding "foo-foo" with HCN levels lower than 10 mg/kg. Residual nitrates and nitrites of 30 mg/kg in the sodium nitrate-treated sample were also within the safe limits of 156 mg/kg allowed in many countries. Organoleptically improved samples were acceptable to the public.

In-situ biogas upgrading during anaerobic digestion of food waste amended with walnut shell biochar at bench scale

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

Linville, Jessica L.; Shen, Yanwen; Ignacio-de Leon, Patricia A.

Here, a modified version of an in-situ CO 2 removal process was applied during AD of food waste with two types of walnut shell biochar (WSB) at bench-scale under batch operating mode. Compared to the coarse WSB, the fine WSB has a higher ash content (43 vs. 36 wt%) and higher concentrations of calcium (31 vs. 19 wt% of ash), magnesium (8.4 vs. 5.6 wt% of ash) and sodium (23.4 vs. 0.3 wt% of ash), but a lower potassium concentration (0.2 vs. 40% wt% of ash). The 0.96 - 3.83 g biochar (g VS added) -1 fine WSB amended digestersmore » produced biogas with 77.5-98.1% CH 4 content by removing 40-96% of the CO 2 compared to the control digesters at mesophilic and thermophilic temperature conditions. In a direct comparison at 1.83 g biochar (g VS added) -1, the fine WSB amended digesters (85.7% CH 4 content and 61% CO 2 removal) outperformed the coarse WSB amended digesters (78.9% CH 4 content and 51% CO 2 removal). Biochar addition also increased alkalinity as CaCO3 from 2,800 mg L -1 in the control digesters to 4,800-6,800 mg L -1 providing process stability for food waste AD.« less

In-situ biogas upgrading during anaerobic digestion of food waste amended with walnut shell biochar at bench scale.

PubMed

Linville, Jessica L; Shen, Yanwen; Ignacio-de Leon, Patricia A; Schoene, Robin P; Urgun-Demirtas, Meltem

2017-06-01

A modified version of an in-situ CO 2 removal process was applied during anaerobic digestion of food waste with two types of walnut shell biochar at bench scale under batch operating mode. Compared with the coarse walnut shell biochar, the fine walnut shell biochar has a higher ash content (43 vs. 36 wt%) and higher concentrations of calcium (31 vs. 19 wt% of ash), magnesium (8.4 vs. 5.6 wt% of ash) and sodium (23.4 vs. 0.3 wt% of ash), but a lower potassium concentration (0.2 vs. 40% wt% of ash). The 0.96-3.83 g biochar (g VS added ) -1 fine walnut shell biochar amended digesters produced biogas with 77.5%-98.1% CH 4 content by removing 40%-96% of the CO 2 compared with the control digesters at mesophilic and thermophilic temperature conditions. In a direct comparison at 1.83 g biochar (g VS added ) -1 , the fine walnut shell biochar amended digesters (85.7% CH 4 content and 61% CO 2 removal) outperformed the coarse walnut shell biochar amended digesters (78.9% CH 4 content and 51% CO 2 removal). Biochar addition also increased alkalinity as CaCO 3 from 2800 mg L -1 in the control digesters to 4800-6800 mg L -1 , providing process stability for food waste anaerobic digestion.

In-situ biogas upgrading during anaerobic digestion of food waste amended with walnut shell biochar at bench scale

DOE PAGES

Linville, Jessica L.; Shen, Yanwen; Ignacio-de Leon, Patricia A.; ...

2017-05-10

Here, a modified version of an in-situ CO 2 removal process was applied during AD of food waste with two types of walnut shell biochar (WSB) at bench-scale under batch operating mode. Compared to the coarse WSB, the fine WSB has a higher ash content (43 vs. 36 wt%) and higher concentrations of calcium (31 vs. 19 wt% of ash), magnesium (8.4 vs. 5.6 wt% of ash) and sodium (23.4 vs. 0.3 wt% of ash), but a lower potassium concentration (0.2 vs. 40% wt% of ash). The 0.96 - 3.83 g biochar (g VS added) -1 fine WSB amended digestersmore » produced biogas with 77.5-98.1% CH 4 content by removing 40-96% of the CO 2 compared to the control digesters at mesophilic and thermophilic temperature conditions. In a direct comparison at 1.83 g biochar (g VS added) -1, the fine WSB amended digesters (85.7% CH 4 content and 61% CO 2 removal) outperformed the coarse WSB amended digesters (78.9% CH 4 content and 51% CO 2 removal). Biochar addition also increased alkalinity as CaCO3 from 2,800 mg L -1 in the control digesters to 4,800-6,800 mg L -1 providing process stability for food waste AD.« less

Remediation of electronic waste polluted soil using a combination of persulfate oxidation and chemical washing.

PubMed

Chen, Fu; Luo, Zhanbin; Liu, Gangjun; Yang, Yongjun; Zhang, Shaoliang; Ma, Jing

2017-12-15

Laboratory experiments were conducted to investigate the efficiency of a simultaneous chemical extraction and oxidation for removing persistent organic pollutants (POPs) and toxic metals from an actual soil polluted by the recycling activity of electronic waste. Various chemicals, including hydroxypropyl-β-cyclodextrin (HPCD), citric acid (CA) and sodium persulfate (SP) were applied synchronously with Fe 2+ activated oxidation to enhance the co-removal of both types of pollutants. It is found that the addition of HPCD can enhance POPs removal through solubilization of POPs and iron chelation; while the CA-chelated Fe 2+ activation process is effective for extracting metals and degrading residual POPs. Under the optimized reagent conditions, 69.4% Cu, 78.1% Pb, 74.6% Ni, 97.1% polychlorinated biphenyls, 93.8% polycyclic aromatic hydrocarbons, and 96.4% polybrominated diphenylethers were removed after the sequential application of SP-HPCD-Fe 2+ and SP-CA-Fe 2+ processes with a duration of 180 and 240 min, respectively. A high dehalogenation efficiency (84.8% bromine and 86.2% chlorine) is observed, suggesting the low accumulation of halogen-containing organic intermediates. The remediated soil can satisfy the national soil quality standard of China. Collectively, co-contaminated soil can be remediated with reasonable time and capital costs through simultaneous application of persulfate oxidation and chemical extraction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Extracting Silicon From Sodium-Process Products

NASA Technical Reports Server (NTRS)

Kapur, V.; Sanjurjo, A.; Sancier, K. M.; Nanis, L.

1982-01-01

New acid leaching process purifies silicon produced in reaction between silicon fluoride and sodium. Concentration of sodium fluoride and other impurities and byproducts remaining in silicon are within acceptable ranges for semi-conductor devices. Leaching process makes sodium reduction process more attractive for making large quantities of silicon for solar cells.

A liquid-metal filling system for pumped primary loop space reactors

NASA Astrophysics Data System (ADS)

Crandall, D. L.; Reed, W. C.

Some concepts for the SP-100 space nuclear power reactor use liquid metal as the primary coolant in a pumped loop. Prior to filling ground engineering test articles or reactor systems, the liquid metal must be purified and circulated through the reactor primary system to remove contaminants. If not removed, these contaminants enhance corrosion and reduce reliability. A facility was designed and built to support Department of Energy Liquid Metal Fast Breeder Reactor tests conducted at the Idaho National Engineering Laboratory. This test program used liquid sodium to cool nuclear fuel in in-pile experiments; thus, a system was needed to store and purify sodium inventories and fill the experiment assemblies. This same system, with modifications and potential changeover to lithium or sodium-potassium (NaK), can be used in the Space Nuclear Power Reactor Program. This paper addresses the requirements, description, modifications, operation, and appropriateness of using this liquid-metal system to support the SP-100 space reactor program.

Interagency Depainting Study Status

NASA Technical Reports Server (NTRS)

Clark-Ingram, Marceia; Cook, Beth

1999-01-01

This document discusses coating removal in general. Sections of this presentation include: regulatory background, the initial parameters of the study, the current parameters of the study, stages in each sequence, preparation of the test specimen, material evaluation testing, chemical stripping, CO2 blasting, Flashjet coating removal, plastic media blasting, sodium bicarbonate wet stripping, water stripping, and wheat starch stripping.

Removal of acetaminophen in water by laccase immobilized in barium alginate.

PubMed

Ratanapongleka, Karnika; Punbut, Supot

2018-02-01

This research has focused on the optimization of immobilized laccase condition and utilization in degradation of acetaminophen contaminated in aqueous solution. Laccase from Lentinus polychrous was immobilized in barium alginate. The effects of laccase immobilization such as sodium alginate concentration, barium chloride concentration and gelation time were studied. The optimal conditions for immobilization were sodium alginate 5% (w/v), barium chloride 5% (w/v) and gelation time of 60 min. Immobilized laccase was then used for acetaminophen removal. Acetaminophen was removed quickly in the first 50 min. The degradation rate and percentage of removal increased when the enzyme concentration increased. Immobilized laccase at 0.57 U/g-alginate showed the maximum removal at 94% in 240 min. The removal efficiency decreased with increasing initial acetaminophen concentration. The K m value for immobilized laccase (98.86 µM) was lower than that of free laccase (203.56 µM), indicating that substrate affinity was probably enhanced by immobilization. The immobilized enzyme exhibited high activity and good acetaminophen removal at pH 7 and temperature of 35°C. The activation energies of free and immobilized laccase for degradation of acetaminophen were 8.08 and 17.70 kJ/mol, respectively. It was also found that laccase stability to pH and temperature increased after immobilization. Furthermore, immobilized laccase could be reused for five cycles. The capability of removal and enzyme activity were retained above 70%.

Different effects of sodium chloride preincubation on cadmium tolerance of Pichia kudriavzevii and Saccharomyces cerevisiae.

PubMed

Ma, Ning; Li, Chunsheng; Dong, Xiaoyan; Wang, Dongfeng; Xu, Ying

2015-08-01

Application of growing microorganisms for cadmium removal is restricted by high cadmium toxicity. The effects of sodium chloride (NaCl) preincubation on the cadmium tolerance and removal ability of Pichia kudriavzevii and Saccharomyces cerevisiae were investigated in this study. NaCl preincubation improved the biomass of P. kudriavzevii under cadmium stress, while no obvious effect was observed in S. cerevisiae. The improved activities of peroxidase (POD) and catalase (CAT) after NaCl preincubation might be an important reason for the decrease of the reactive oxygen species (ROS) accumulation, cell death, and oxidative damage of proteins and lipids induced by cadmium, contributing to the improvement of the yeast growth. The cadmium bioaccumulation capacity of P. kudriavzevii decreased significantly after NaCl preincubation, which played an important role in mitigating the cadmium toxicity to the yeast. The cadmium removal rate of P. kudriavzevii was obviously higher than S. cerevisiae and was significantly enhanced after NaCl preincubation. The results suggested that NaCl preincubation improved the cadmium tolerance and removal ability of P. kudriavzevii. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preliminary Evaluation of the Control of Microbial Fouling by Laboratory and Pilot-Scale Air-Stripping Columns

DTIC Science & Technology

1985-03-01

used to remove trichloroethylene (TCE) from contaminated well water. 7 MATERIALS Chemicals: Trichloroethylene (Aldrich chemical, Milwaukee, WI), sodium ...Cleveland, OH), sodium hydrcxide (J.T. Baker, Phillipsburg, NJ), potassium dichloroisocyanurate (Dorex Inc., Frankfort, IL), potassium iodide starch...NJ). Media and Reagents: Plate count agar (Difco Laboratories, Detroit, MI), lauryl tryptose broth (Difco Laboratories, Detroit, MI), motility medium

Rubidium, sodium and ouabain interactions on the influx of rubidium in rat red blood cells

PubMed Central

Beaugé, L. A.; Ortíz, Olga

1970-01-01

1. The activation curve of rubidium influx by external rubidium in rat red cells showed an inflexion at a concentration around 0·2 mM. This inflexion point was displaced to the right by ouabain. 2. The removal of sodium from the external solution changed the characteristics of the activation curve of rubidium influx. At external rubidium below 0·5 mM the uptake increased whereas above that concentration there was marked reduction. Thus the sodium-free effect on rubidium uptake is dependent on the external rubidium concentration. 3. With 0·25 mM rubidium, the relationship between increase of rubidium influx and reduction of external sodium followed a more or less exponential function. All the increment was ouabain-sensitive. 4. With a rubidium concentration above 0·5 mM the reduction of the rubidium uptake, as sodium was removed, followed curves of complex shape. With 10 mM rubidium, when sodium was reduced from 5 mM to zero, there was an increase instead of a further reduction. These results suggest interactions of several effects. 5. The ouabain sensitivity of the rubidium influx in rat red cells is smaller than in other systems studied up to now. The dose—response curve was shifted to the right as the rubidium concentration increased and a plateau was obtained with rubidium only below 1 mM at 10-5 M ouabain. When plotted as a percentage of the maximal inhibition the points fell into the theoretical curve following a simple one reactant/one site reaction. 6. Ouabain inhibition seems to be a complex function of at least three variables: the concentration of the glycoside, the concentration of sodium and the concentration of rubidium. When sodium was absent, 10 μM rubidium was able to prevent, to a great extent, the inhibition produced by 10-5 and 10-4 M ouabain. PMID:5499809

Disinfection of Contaminated Canals by Different Laser Wavelengths, while Performing Root Canal Therapy

PubMed Central

Asnaashari, Mohammad; Safavi, Nassimeh

2013-01-01

Removal of smear layer and disinfection of canals are important objectives of teeth root canal cleaning. In order to achieve this purpose, rinsing substances, intra canal drugs as well as ultrasound are used. Today, use of laser to remove smear layer and to disinfect root canals has increasingly attracted the attentions. Till now different lasers such as CO2, Nd:YAG, Er:YAG, Er,Cr:YSGG have been used for debris and smear removal from the canals. Numerous studies have shown that Er:YAG is the most appropriate laser for intra canal debris and smear removal. In addition different laser wavelengths have been used directly or as an adjunctive to disinfect canals. Laser light can penetrate areas of canals where irrigating and disinfecting solutions cannot reach, like secondary canals and deep dentinal tubules and also can eliminate microorganisms. Different studies have confirmed the penetration of Nd:YAG laser in deep dentin and reduction of microorganisms penetration. But studies on comparison of antibacterial effects of Nd:YAG laser with sodium hypochlorite showed effectiveness of both, with a better effect for sodium hypochlorite. Studies performed in relation with anti-microbial effects of Diode laser with various parameters show that this laser can be effective in reducing intra canal bacterial count and penetration in the depth of 500 microns in dentin. In studies performed on Diode laser in combination with canal irrigating solutions such as sodium hypochlorite and oxygenated water better results were obtained. Although studies on disinfection by the Erbium laser family show that use of this laser alone can be effective in disinfecting canals, studies evaluating the disinfecting effects of this laser and different concentrations of sodium hypochlorite show that the latter alone is more effective in disinfecting canals. And better results were obtained when Erbium laser was used in combination with sodium hypochlorite irrigating solution in canals. Results of the aforementioned articles indicate that this laser is effective in combination with a rinsing solution such as sodium hypochlorite. Results from studies including several types of the different Er:YAG, Ho:YAG, Nd:YAG, Er,Cr:YSGG lasers in disinfecting canals showed that all wavelengths used in disinfection for different thicknesses of dentin were efficacious without damaging thermal effect. Considering that use of different lasers in canals can be accompanied with temperature increase which can sometimes lead to damages to teeth and surrounding tissues, thus the use of photochemical phenomenon for elimination of microorganisms have attracted attention of many researchers. Studies in this field imply the efficacy of this method in reducing canal bacterial count and recommend its use as an adjunctive after biomechanical preparation of canals. Results from performed studies show removal of intra canal debris and smear layer by different lasers and particularly the Erbium laser family. Furthermore various laser wavelengths, particularly of Diode and Nd:YAG lasers can be effective in reducing intra canal microbial count. Maximum effect is obtained when laser light is used in canals in combination with sodium hypochlorite irrigating substance in appropriate concentration. Therefore use of laser energy can improve success rate of root canal treatments. PMID:25606301

Degradation of microcystin-RR using boron-doped diamond electrode.

PubMed

Zhang, Chunyong; Fu, Degang; Gu, Zhongze

2009-12-30

Microcystins (MCs), produced by blue-green algae, are one of the most common naturally occurring toxins found in natural environment. The presence of MCs in drinking water sources poses a great threat to people's health. In this study, the degradation behavior of microcystin-RR on boron-doped diamond (BDD) electrode was investigated under galvanostatic conditions. Such parameters as reaction time, supporting electrolyte and applied current density were varied in order to determine their effects on this oxidation process. The experimental results revealed the suitability of electrochemical processes employing BDD electrode for removing MC-RR from the solution. However, the efficient removal of MC-RR only occurred in the presence of sodium chloride that acted as redox mediators and the reaction was mainly affected by the chloride concentration (c(NaCl)) and applied current density (I(appl)). Full and quick removal of 0.50 microg/ml MC-RR in solution was achieved when the operating conditions of c(NaCl) and I(appl) were 20mM and 46.3 mA/cm(2), or 35 mM and 18.2 mA/cm(2) respectively. The kinetics for MC-RR degradation followed a pesudo-first order reaction in most cases, indicating the process was under mass transfer control. As a result of its excellent performance, the BDD technology could be considered as a promising alternative to promote the degradation of MC-RR than chlorination in drinking water supplies.

Measurement of plasma decay processes in mixture of sodium and argon by coherent microwave scattering

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

Zhang Zhili; Shneider, Mikhail N.

2010-03-15

This paper presents the experimental measurement and computational model of sodium plasma decay processes in mixture of sodium and argon by using radar resonance-enhanced multiphoton ionization (REMPI), coherent microwave Rayleigh scattering of REMPI. A single laser beam resonantly ionizes the sodium atoms by means of 2+1 REMPI process. The laser beam can only generate the ionization of the sodium atoms and have negligible ionization of argon. Coherent microwave scattering in situ measures the total electron number in the laser-induced plasma. Since the sodium ions decay by recombination with electrons, microwave scattering directly measures the plasma decay processes of the sodiummore » ions. A theoretical plasma dynamic model, including REMPI of the sodium and electron avalanche ionization (EAI) of sodium and argon in the gas mixture, has been developed. It confirms that the EAI of argon is several orders of magnitude lower than the REMPI of sodium. The theoretical prediction made for the plasma decay process of sodium plasma in the mixture matches the experimental measurement.« less

Removal of antibiotic cloxacillin by means of electrochemical oxidation, TiO2 photocatalysis, and photo-Fenton processes: analysis of degradation pathways and effect of the water matrix on the elimination of antimicrobial activity.

PubMed

Serna-Galvis, Efraim A; Giraldo-Aguirre, Ana L; Silva-Agredo, Javier; Flórez-Acosta, Oscar A; Torres-Palma, Ricardo A

2017-03-01

This study evaluates the treatment of the antibiotic cloxacillin (CLX) in water by means of electrochemical oxidation, TiO 2 photocatalysis, and the photo-Fenton system. The three treatments completely removed cloxacillin and eliminated the residual antimicrobial activity from synthetic pharmaceutical wastewater containing the antibiotic, commercial excipients, and inorganic ions. However, significant differences in the degradation routes were found. In the photo-Fenton process, the hydroxyl radical was involved in the antibiotic removal, while in the TiO 2 photocatalysis process, the action of both the holes and the adsorbed hydroxyl radicals degraded the pollutant. In the electrochemical treatment (using a Ti/IrO 2 anode in sodium chloride as supporting electrolyte), oxidation via HClO played the main role in the removal of CLX. The analysis of initial by-products showed five different mechanistic pathways: oxidation of the thioether group, opening of the central β-lactam ring, breakdown of the secondary amide, hydroxylation of the aromatic ring, and decarboxylation. All the oxidation processes exhibited the three first pathways. Moreover, the aromatic ring hydroxylation was found in both photochemical treatments, while the decarboxylation of the pollutant was only observed in the TiO 2 photocatalysis process. As a consequence of the degradation routes and mechanistic pathways, the elimination of organic carbon was different. After 480 and 240 min, the TiO 2 photocatalysis and photo-Fenton processes achieved ∼45 and ∼15 % of mineralization, respectively. During the electrochemical treatment, 100 % of the organic carbon remained even after the antibiotic was treated four times the time needed to degrade it. In contrast, in all processes, a natural matrix (mineral water) did not considerably inhibit pollutant elimination. However, the presence of glucose in the water significantly affected the degradation of CLX by means of TiO 2 photocatalysis.

Polyurethane foam loaded with SDS for the adsorption of cationic dyes from aqueous medium: Multivariate optimization of the loading process.

PubMed

Robaina, Nicolle F; Soriano, Silvio; Cassella, Ricardo J

2009-08-15

This paper reports the development of a new procedure for the adsorption of four cationic dyes (Rhodamine B, Methylene Blue, Crystal Violet and Malachite Green) from aqueous medium employing polyurethane foam (PUF) loaded with sodium dodecylsulfate (SDS) as solid phase. PUF loading process was based on the stirring of 200mg PUF cylinders with acidic solutions containing SDS. The conditions for loading were optimized by response surface methodology (RSM) using a Doehlert design with three variables that were SDS and HCl concentrations and stirring time. Results obtained in the optimization process showed that the stirring time is not a relevant parameter in the PUF loading, evidencing that the transport of SDS from solution to PUF surface is fast. On the other hand, both SDS and HCl concentrations were important parameters causing significant variation in the efficiency of the resulting solid phase for the removal of dyes from solution. At optimized conditions, SDS and HCl concentrations were 4.0 x 10(-4) and 0.90 mol L(-1), respectively. The influence of stirring time was evaluated by univariate methodology. A 20 min stirring time was established in order to make the PUF loading process fast and robust without losing efficiency. The procedure was tested for the removal of the four cationic dyes from aqueous solutions and removal efficiencies always better than 90% were achieved for the two concentrations tested (2.0 x 10(-5) and 1.0 x 10(-4)mol L(-1)).

Mechanism of basolateral membrane H+/OH-/HCO-3 transport in the rat proximal convoluted tubule. A sodium-coupled electrogenic process

PubMed Central

1985-01-01

In order to examine the mechanism of basolateral membrane H+/OH-/HCO-3 transport, a method was developed for the measurement of cell pH in the vivo doubly microperfused rat proximal convoluted tubule. A pH- sensitive fluorescein derivative, (2',7')-bis(carboxyethyl)-(5,6)- carboxyfluorescein, was loaded into cells and relative changes in fluorescence at two excitation wavelengths were followed. Calibration was accomplished using nigericin with high extracellular potassium concentrations. When luminal and peritubular fluids were pH 7.32, cell pH was 7.14 +/- 0.01. Decreasing peritubular pH from 7.32 to 6.63 caused cell pH to decrease from 7.16 +/- 0.02 to 6.90 +/- 0.03. This effect occurred at an initial rate of 2.4 +/- 0.3 pH units/min, and was inhibited by 0.5 mM SITS. Lowering the peritubular sodium concentration from 147 to 25 meq/liter caused cell pH to decrease from 7.20 +/- 0.03 to 6.99 +/- 0.01. The effect of peritubular sodium concentration on cell pH was inhibited by 0.5 mM SITS, but was unaffected by 1 mM amiloride. In addition, when peritubular pH was decreased in the total absence of luminal and peritubular sodium, the rate of cell acidification was 0.2 +/- 0.1 pH units/min, a greater than 90% decrease from that in the presence of sodium. Cell depolarization achieved by increasing the peritubular potassium concentration caused cell pH to increase, an effect that was blocked by peritubular barium or luminal and peritubular sodium removal. Lowering the peritubular chloride concentration from 128 to 0 meq/liter did not affect cell pH. These results suggest the existence of an electrogenic, sodium-coupled H+/OH- /HCO-3 transport mechanism on the basolateral membrane of the rat proximal convoluted tubule. PMID:2999293

Application of the base catalyzed decomposition process to treatment of PCB-contaminated insulation and other materials associated with US Navy vessels. Final report

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

Schmidt, A.J.; Zacher, A.H.; Gano, S.R.

1996-09-01

The BCD process was applied to dechlorination of two types of PCB-contaminated materials generated from Navy vessel decommissioning activities at Puget Sound Naval Shipyard: insulation of wool felt impregnated with PCB, and PCB-containing paint chips/debris from removal of paint from metal surfaces. The BCD process is a two-stage, low-temperature chemical dehalogenation process. In Stage 1, the materials are mixed with sodium bicarbonate and heated to 350 C. The volatilized halogenated contaminants (eg, PCBs, dioxins, furans), which are collected in a small volume of particulates and granular activated carbon, are decomposed by the liquid-phase reaction (Stage 2) in a stirred-tank reactor,more » using a high-boiling-point hydrocarbon oil as the reaction medium, with addition of a hydrogen donor, a base (NaOH), and a catalyst. The tests showed that treating wool felt insulation and paint chip wastes with Stage 2 on a large scale is feasible, but compared with current disposal costs for PCB-contaminated materials, using Stage 2 would not be economical at this time. For paint chips generated from shot/sand blasting, the solid-phase BCD process (Stage 1) should be considered, if paint removal activities are accelerated in the future.« less

Comparative investigation of X-ray contrast medium degradation by UV/chlorine and UV/H2O2.

PubMed

Kong, Xiujuan; Jiang, Jin; Ma, Jun; Yang, Yi; Pang, Suyan

2018-02-01

The degradation of iopamidol and diatrizoate sodium (DTZ) by UV/chlorine was carried out according to efficiency, mechanism, and oxidation products, and compared to that by UV/H 2 O 2 . The pseudo-first order rate (k') of iopamidol and DTZ was accelerated by UV/chlorine compared to that by UV and chlorine alone. k' of iopamidol and DTZ by UV/chlorine increased with increasing chlorine dosage. Both of iopamidol and DTZ could not be effectively removed by UV/H 2 O 2 compared to that by UV/chlorine. Secondary radicals (Cl 2 - and ClO) rather than primary radicals (HO and Cl) were demonstrated to be mainly responsible for the enhanced removal of iopamidol and DTZ by UV/chlorine. The oxidation products of iopamidol and DTZ resulting from UV/chlorine and UV/H 2 O 2 process were identified, and differences existed in the two systems. IO 3 - (the desired sink of I - ) was the major inorganic product in the UV/chlorine process whereas I - was the predominant inorganic product in the UV/H 2 O 2 process. The formation of chlorine-containing products during the degradation of iopamidol and DTZ by UV/chlorine was also observed. H-abstraction, additions, de-iodination were shared during the degradation of iopamidol by UV/chlorine and UV/H 2 O 2 . Neutral pH condition was preferred for the removal of iopamidol and DTZ by UV/chlorine. UV/chlorine could also be applied in real waters for the removal of iopamidol and DTZ. Copyright © 2017 Elsevier Ltd. All rights reserved.

PROCESSING ALTERNATIVES FOR DESTRUCTION OF TETRAPHENYLBORATE

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

Lambert, D; Thomas Peters, T; Samuel Fink, S

Two processes were chosen in the 1980's at the Savannah River Site (SRS) to decontaminate the soluble High Level Waste (HLW). The In Tank Precipitation (ITP) process (1,2) was developed at SRS for the removal of radioactive cesium and actinides from the soluble HLW. Sodium tetraphenylborate was added to the waste to precipitate cesium and monosodium titanate (MST) was added to adsorb actinides, primarily uranium and plutonium. Two products of this process were a low activity waste stream and a concentrated organic stream containing cesium tetraphenylborate and actinides adsorbed on monosodium titanate (MST). A copper catalyzed acid hydrolysis process wasmore » built to process (3, 4) the Tank 48H cesium tetraphenylborate waste in the SRS's Defense Waste Processing Facility (DWPF). Operation of the DWPF would have resulted in the production of benzene for incineration in SRS's Consolidated Incineration Facility. This process was abandoned together with the ITP process in 1998 due to high benzene in ITP caused by decomposition of excess sodium tetraphenylborate. Processing in ITP resulted in the production of approximately 1.0 million liters of HLW. SRS has chosen a solvent extraction process combined with adsorption of the actinides to decontaminate the soluble HLW stream (5). However, the waste in Tank 48H is incompatible with existing waste processing facilities. As a result, a processing facility is needed to disposition the HLW in Tank 48H. This paper will describe the process for searching for processing options by SRS task teams for the disposition of the waste in Tank 48H. In addition, attempts to develop a caustic hydrolysis process for in tank destruction of tetraphenylborate will be presented. Lastly, the development of both a caustic and acidic copper catalyzed peroxide oxidation process will be discussed.« less

Automobile shredded residue valorisation by hydrometallurgical metal recovery.

PubMed

Granata, Giuseppe; Moscardini, Emanuela; Furlani, Giuliana; Pagnanelli, Francesca; Toro, Luigi

2011-01-15

The aim of this work was developing a hydrometallurgical process to recover metals from automobile shredded residue (or car fluff). Automobile shredded residue (ASR) was characterised by particle size distribution, total metal content and metal speciation in order to guide the choice of target metals and the operating conditions of leaching. Characterisation results showed that Fe is the most abundant metal in the waste, while Zn was the second abundant metal in the fraction with diameter lower than 500 μm. Sequential extractions denoted that Zn was easily extractable by weak acid attack, while Fe and Al required a strong acid attack to be removed. In order to recover zinc from <500 μm fraction leaching tests were operated using acetic acid, sulphuric acid and sodium hydroxide at different concentrations. Sulphuric acid determined the highest zinc extraction yield, while acetic acid determined the highest zinc extractive selectivity. Sodium hydroxide promoted an intermediate situation between sulphuric and acetic acid. Zn recovery by electro winning using acetic leach liquor determined 95% of Zn electro deposition yield in 1h, while using sulphuric leach liquor 40% yield in 1h and 50% yield in 2h were obtained. Simulation results showed that the sulphuric leaching process was more attractive than acetic leaching process. Copyright © 2010 Elsevier B.V. All rights reserved.

Effect of various types of thermochemical processing of sewage sludges on phosphorus speciation, solubility, and fertilization performance.

PubMed

Steckenmesser, Daniel; Vogel, Christian; Adam, Christian; Steffens, Diedrich

2017-04-01

Sewage sludge has one of the highest phosphorus (P) recovery potentials of all waste materials. Therefore, P-recycling from sewage sludge could contribute to closing the P-cycle. Recently, various thermal processes for P-recovery have been developed, but there is still a demand for information on the effect of different process parameters (e.g. additives and temperature) on P-speciation and especially on the fertilization performance. In the present study, two common methods (low-temperature conversion at 400-500°C and thermochemical treatment at 950°C) were investigated and combined to produce highly bioavailable P-fertilizers from two different types of sewage sludge based on chemical phosphorus precipitation (Chem-P) and enhanced biological phosphorus removal (Bio-P). The results of P-fractionation, X-ray diffraction analysis, and pot experiments with maize showed that Bio-P sludges attain high P-plant-availability after treatment at low temperatures (400°C). In contrast, Chem-P sludges can adequately be treated at higher temperatures under reductive conditions with sodium additives to form highly bioavailable calcium-sodium-phosphate. Additionally, also highly heavy-metal contaminated sludges can be thermochemically treated at high temperatures to achieve the legal requirements for fertilizers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of probiotics on patulin removal from synbiotic apple juice.

PubMed

Zoghi, Alaleh; Khosravi-Darani, Kianoush; Sohrabvandi, Sara; Attar, Hosein; Alavi, Sayed Abolhasan

2017-06-01

Studies have reported the occurrence of the mycotoxin patulin in apple products. The aim of this study was to produce synbiotic apple juice and investigate the detoxification of patulin by Lactobacillus acidophilus and Lactobacillus plantarum as probiotic strains. The impact of seven process variables on efficiency of toxin removal was investigated using Plackett-Burman design and presence of the surface-layer proteins as binding site of probiotics to patulin was confirmed during 6 weeks of cold storage. Results showed that the removal of patulin by probiotic bacteria from apple juice depends significantly (P < 0.05) on the fructooligosaccharide content (as a prebiotic), concentration of patulin and the addition of ascorbic acid. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of cell surface proteins of probiotic strains revealed that surface layer proteins have an important role in patulin removal from apple juice. In the best conditions, 91.23% of initial patulin concentration was removed from juice during 6 weeks refrigerated storage. No significant difference was observed in organoleptic properties of the synbiotic apple juice and raw sample. In the best condition reported in this study, contaminated synbiotic apple juice by patulin will be safe for consumers after the first day of probiotic inoculation. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Biofilm regeneration on carriers in MBBR used for vitamin C wastewater treatment.

PubMed

Hu, X B; Wang, Zh; Xu, K; Ren, H Q

2013-01-01

Methods were investigated for biofilm regeneration on carriers in a moving bed biofilm reactor used for vitamin C production wastewater treatment. Three ordinary chemical cleaning agents (hydrochloric acid, sodium hydroxide, and sodium hypochlorite) and physical drying were chosen for evaluation as methods for biofilm detachment. The results showed that these methods all had some degree of biofilm removal effectiveness. Treatment with 3% hydrochloric acid (w/w) achieved the maximum degree of biofilm detachment, at 75.2%. Biofilm biomass re-formed on carriers, from the maximum degree of biofilm detachment, quickly by an increase of 76.17 g m(-2) month(-1). It was concluded that treatment with 3% acid was the best choice for biofilm removal and regeneration.

Treatability assessment of polycyclic aromatic hydrocarbons contaminated marine sediments using permanganate, persulfate and Fenton oxidation processes.

PubMed

Shih, Yu-Jen; Binh, Nguyen Thanh; Chen, Chiu-Wen; Chen, Chih-Feng; Dong, Cheng-Di

2016-05-01

Various chemical oxidation techniques, such as potassium permanganate (KMnO4), sodium persulfate (Na2S2O8), Fenton (H2O2/Fe(2+)), and the modified persulfate and Fenton reagents (activated by ferrous complexes), were carried out to treat marine sediments that were contaminated with polycyclic aromatic hydrocarbons (PAHs) and dredged from Kaohsiung Harbor in Taiwan. Experimental results revealed that KMnO4 was the most effective of the tested oxidants in PAH degradation. Owing to the high organic matter content in the sediment that reduced the efficiencies of Na2S2O8 and regular Fenton reactions, a large excess of oxidant was required. Nevertheless, KH2PO4, Na4P2O7 and four chelating agents (EDTA, sodium citrate, oxalic acid, and sodium oxalate) were utilized to stabilize Fe(II) in activating the Na2S2O8 and Fenton oxidations, while Fe(II)-citrate remarkably promoted the PAH degradation. Increasing the molecular weight and number of rings of PAH did not affect the overall removal efficiencies. The correlation between the effectiveness of the oxidation processes and the physicochemical properties of individual PAH was statistically analyzed. The data implied that the reactivity of PAH (electron affinity and ionization potential) affected its treatability more than did its hydrophobicity (Kow, Koc and Sw), particularly using experimental conditions under which PAHs could be effectively oxidized. Copyright © 2016 Elsevier Ltd. All rights reserved.

Stabilities of nitrogen containing heterocyclic radicals and geometrical influences on non-radiative processes in organic molecules

NASA Technical Reports Server (NTRS)

Evleth, E. M.

1971-01-01

Theoretical and experimental work on generating radicals by removal of a hydrogen atom from pyrrole, imidazole, indole, and carbazole is reported. Photophysical studies on indolizine and related aza-derivatives show that materials having large S2-S1 energy gaps might exhibit upper state fluorescence. Photodecomposition quantum yields of a series of sterically hindered p-aminobenzene diazonium cations in water were found structurally and wavelength dependent and unquenched in aqueous sodium bromide solutions. Photodecomposition of diazonium materials did not produce a metastable species with a longer lifetime than 1 msec.

Cadmium-109 Radioisotope Adsorption onto Polypyrrole Coated Sawdust of Dryobalanops aromatic: Kinetics and Adsorption Isotherms Modelling

PubMed Central

Olatunji, Michael Adekunle; Khandaker, Mayeen Uddin; Amin, Yusoff Mohd; Mahmud, Habibun Nabi Muhammad Ekramul

2016-01-01

A radiotracer study was conducted to investigate the removal characteristics of cadmium (109Cd) from aqueous solution by polypyrrole/ sawdust composite. Several factors such as solution pH, sorbent dosage, initial concentration, contact time, temperature and interfering metal ions were found to have influence on the adsorption process. The kinetics of adsorption was relatively fast, reaching equilibrium within 3 hours. A lowering of the solution pH reduced the removal efficiency from 99.3 to ~ 46.7% and an ambient temperature of 25°C was found to be optimum for maximum adsorption. The presence of sodium and potassium ions inhibited 109Cd removal from its aqueous solution. The experimental data for 109Cd adsorption showed a very good agreement with the Langmuir isotherm and a pseudo-first order kinetic model. The surface condition of the adsorbent before and after cadmium loading was investigated using BET, FESEM and FTIR. Considering the low cost of the precursor’s materials and the toxicity of 109Cd radioactive metal, polypyrrole synthesized on the sawdust of Dryobalanops aromatic could be used as an efficient adsorbent for the removal of 109Cd radioisotope from radionuclide-containing effluents. PMID:27706232

Chemical and morphological characterization of sugarcane bagasse submitted to a delignification process for enhanced enzymatic digestibility

PubMed Central

2011-01-01

Background In recent years, biorefining of lignocellulosic biomass to produce multi-products such as ethanol and other biomaterials has become a dynamic research area. Pretreatment technologies that fractionate sugarcane bagasse are essential for the successful use of this feedstock in ethanol production. In this paper, we investigate modifications in the morphology and chemical composition of sugarcane bagasse submitted to a two-step treatment, using diluted acid followed by a delignification process with increasing sodium hydroxide concentrations. Detailed chemical and morphological characterization of the samples after each pretreatment condition, studied by high performance liquid chromatography, solid-state nuclear magnetic resonance, diffuse reflectance Fourier transformed infrared spectroscopy and scanning electron microscopy, is reported, together with sample crystallinity and enzymatic digestibility. Results Chemical composition analysis performed on samples obtained after different pretreatment conditions showed that up to 96% and 85% of hemicellulose and lignin fractions, respectively, were removed by this two-step method when sodium hydroxide concentrations of 1% (m/v) or higher were used. The efficient lignin removal resulted in an enhanced hydrolysis yield reaching values around 100%. Considering the cellulose loss due to the pretreatment (maximum of 30%, depending on the process), the total cellulose conversion increases significantly from 22.0% (value for the untreated bagasse) to 72.4%. The delignification process, with consequent increase in the cellulose to lignin ratio, is also clearly observed by nuclear magnetic resonance and diffuse reflectance Fourier transformed infrared spectroscopy experiments. We also demonstrated that the morphological changes contributing to this remarkable improvement occur as a consequence of lignin removal from the sample. Bagasse unstructuring is favored by the loss of cohesion between neighboring cell walls, as well as by changes in the inner cell wall structure, such as damaging, hole formation and loss of mechanical resistance, facilitating liquid and enzyme access to crystalline cellulose. Conclusions The results presented herewith show the efficiency of the proposed method for improving the enzymatic digestibility of sugarcane bagasse and provide understanding of the pretreatment action mechanism. Combining the different techniques applied in this work warranted thorough information about the undergoing morphological and chemical changes and was an efficient approach to understand the morphological effects resulting from sample delignification and its influence on the enhanced hydrolysis results. PMID:22122978

Calcium transport in turtle bladder

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

Sabatini, S.; Kurtzman, N.A.

1987-12-01

Unidirectional {sup 45}Ca fluxes were measured in the turtle bladder under open-circuit and short-circuit conditions. In the open-circuited state net calcium flux (J{sup net}{sub Ca}) was secretory (serosa to mucosa). Ouabain reversed J{sup net}{sub Ca} to an absorptive flux. Amiloride reduced both fluxes such that J{sup net}{sub Ca} was not significantly different from zero. Removal of mucosal sodium caused net calcium absorption; removal of serosal sodium caused calcium secretion. When bladders were short circuited, J{sup net}{sub Ca} decreased to approximately one-third of control value but remained secretory. When ouabain was added under short-circuit conditions, J{sup net}{sub Ca} was similar inmore » magnitude and direction to ouabain under open-circuited conditions (i.e., absorptive). Tissue {sup 45}Ca content was {approx equal}30-fold lower when the isotope was placed in the mucosal bath, suggesting that the apical membrane is the resistance barrier to calcium transport. The results obtained in this study are best explained by postulating a Ca{sup 2+}-ATPase on the serosa of the turtle bladder epithelium and a sodium-calcium antiporter on the mucosa. In this model, the energy for calcium movement would be supplied, in large part, by the Na{sup +}-K{sup +}-ATPase. By increasing cell sodium, ouabain would decrease the activity of the mucosal sodium-calcium exchanger (or reverse it), uncovering active calcium transport across the serosa.« less

Core filaments of the nuclear matrix

PubMed Central

1990-01-01

The nuclear matrix is concealed by a much larger mass of chromatin, which can be removed selectively by digesting nuclei with DNase I followed by elution of chromatin with 0.25 M ammonium sulfate. This mild procedure removes chromatin almost completely and preserves nuclear matrix morphology. The complete nuclear matrix consists of a nuclear lamina with an interior matrix composed of thick, polymorphic fibers and large masses that resemble remnant nucleoli. Further extraction of the nuclear matrices of HeLa or MCF-7 cells with 2 M sodium chloride uncovered a network of core filaments. A few dark masses remained enmeshed in the filament network and may be remnants of the nuclear matrix thick fibers and nucleoli. The highly branched core filaments had diameters of 9 and 13 nm measured relative to the intermediate filaments. They may serve as the core structure around which the matrix is constructed. The core filaments retained 70% of nuclear RNA. This RNA consisted both of ribosomal RNA precursors and of very high molecular weight hnRNA with a modal size of 20 kb. Treatment with RNase A removed the core filaments. When 2 M sodium chloride was used directly to remove chromatin after DNase I digestion without a preceding 0.25 M ammonium sulfate extraction, the core filaments were not revealed. Instead, the nuclear interior was filled with amorphous masses that may cover the filaments. This reflected a requirement for a stepwise increase in ionic strength because gradual addition of sodium chloride to a final concentration of 2 M without an 0.25 M ammonium sulfate extraction uncovered core filaments. PMID:2307700

Changes in the energy and sodium content of main entrées in US chain restaurants from 2010 to 2011.

PubMed

Wu, Helen W; Sturm, Roland

2014-02-01

The food environment shapes individual diets, and as food options change, energy and sodium intake may also shift. Understanding whether and how restaurant menus evolve in response to labeling laws and public health pressures could inform future efforts to improve the food environment. To track changes in the energy and sodium content of US chain restaurant main entrées between spring 2010 (when the Affordable Care Act was passed, which included a federal menu labeling requirement) and spring 2011. Nutrition information was collected from top US chain restaurants' websites, comprising 213 unique brands. Descriptive statistics and regression analysis evaluated change across main entrées overall and compared entrées that were added, removed, and unchanged. Tests of means and proportions were conducted for individual restaurant brands to see how many made significant changes. Separate analyses were conducted for children's menus. Mean energy and sodium did not change significantly overall, although mean sodium was 70 mg lower across all restaurants in added vs removed menu items at the 75th percentile. Changes were specific to restaurant brands or service model: family-style restaurants reduced sodium among higher-sodium entrées at the 75th percentile, but not on average, and entrées still far exceeded recommended limits. Fast-food restaurants decreased mean energy in children's menu entrées by 40 kcal. A few individual restaurant brands made significant changes in energy or sodium, but the vast majority did not, and not all changes were in the healthier direction. Among those brands that did change, there were slightly more brands that reduced energy and sodium compared with those that increased it. Industry marketing and pledges may create a misleading perception that restaurant menus are becoming substantially healthier, but both healthy and unhealthy menu changes can occur simultaneously. Our study found no meaningful changes overall across a 1-year time period. Longer-term studies are needed to track changes over time, particularly after the federal menu labeling law is implemented. Copyright © 2014 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Efficient removal of atrazine from aqueous solutions using magnetic Saccharomyces cerevisiae bionanomaterial.

PubMed

Wu, Xin; He, Huijun; Yang, William L; Yu, Jiaping; Yang, Chunping

2018-06-17

A novel bionanomaterial comprising Saccharomyces cerevisiae (S. cerevisiae) and Fe 3 O 4 nanoparticles encapsulated in a sodium alginate-polyvinyl alcohol (SA-PVA) matrix was synthesized for the efficient removal of atrazine from aqueous solutions. The effects of the operating parameters, nitrogen source, and glucose and Fe 3+ contents on atrazine removal were investigated, and the intermediates were detected by gas chromatography-mass spectrometry (GC-MS). In addition, the synthesized Fe 3 O 4 particles were characterized by XRD, EDX, HR-TEM, FTIR, and hysteresis loops, and the bionanomaterial was characterized by SEM. The results showed that the maximum removal efficiency of 100% was achieved at 28 °C, a pH of 7.0, and 150 rpm with an initial atrazine concentration of 2.0 mg L -1 and that the removal efficiency was still higher than 95.53% even when the initial atrazine concentration was 50 mg L -1 . Biodegradation was demonstrated to be the dominant removal mechanism for atrazine because atrazine was consumed as the sole carbon source for S. cerevisiae. The results of GC-MS showed that dechlorination, dealkylation, deamination, isomerization, and mineralization occurred in the process of atrazine degradation, and thus, a new degradation pathway was proposed. These results indicated that this bionanomaterial has great potential for the bioremediation of atrazine-contaminated water.

Removal of Ca2+ and Zn2+ from aqueous solutions by zeolites NaP and KP.

PubMed

Yusof, Alias Mohd; Malek, Nik Ahmad Nizam Nik; Kamaruzaman, Nurul Asyikin; Adil, Muhammad

2010-01-01

Zeolites P in sodium (NaP) and potassium (KP) forms were used as adsorbents for the removal of calcium (Ca2+) and zinc (Zn2+) cations from aqueous solutions. Zeolite KP was prepared by ion exchange of K+ with Na+ which neutralizes the negative charge of the zeolite P framework structure. The ion exchange capacity of K+ on zeolite NaP was determined through the Freundlich isotherm equilibrium study. Characterization of zeolite KP was determined using infrared spectroscopy and X-ray diffraction (XRD) techniques. From the characterization, the structure of zeolite KP was found to remain stable after the ion exchange process. Zeolites KP and NaP were used for the removal of Ca and Zn from solution. The amount of Ca2+ and Zn2+ in aqueous solution before and after the adsorption by zeolites was analysed using the flame atomic absorption spectroscopy method. The removal of Ca2+ and Zn2+ followed the Freundlich isotherm rather than the Langmuir isotherm model. This result also revealed that zeolite KP adsorbs Ca2+ and Zn2+ more than zeolite NaP and proved that modification of zeolite NaP with potassium leads to an increase in the adsorption efficiency of the zeolite. Therefore, the zeolites NaP and KP can be used for water softening (Ca removal) and reducing water pollution/toxicity (Zn removal).

Process for combined control of mercury and nitric oxide.

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

Livengood, C. D.; Mendelsohn, M. H.

Continuing concern about the effects of mercury in the environment may lead to requirements for the control of mercury emissions from coal-fired power plants. If such controls are mandated, the use of existing flue-gas cleanup systems, such as wet scrubbers currently employed for flue-gas desulfurization, would be desirable, Such scrubbers have been shown to be effective for capturing oxidized forms of mercury, but cannot capture the very insoluble elemental mercury (Hg{sup 0}) that can form a significant fraction of the total emissions. At Argonne National Laboratory, we have proposed and tested a concept for enhancing removal of Hg{sup 0}, as well as nitric oxide, through introduction of an oxidizing agent into the flue gas upstream of a scrubber, which readily absorbs the soluble reaction products. Recently, we developed a new method for introducing the oxidizing agent into the flue-gas stream that dramatically improved reactant utilization. The oxidizing agent employed was NOXSORB{trademark}, which is a commercial product containing chloric acid and sodium chlorate. When a dilute solution of this agent was introduced into a gas stream containing Hg{sup 0} and other typical flue-gas species at 300 F, we found that about 100% of the mercury was removed from the gas phase and recovered in process liquids. At the same time, approximately 80% of the nitric oxide was removed. The effect of sulfur dioxide on this process was also investigated and the results showed that it slightly decreased the amount of Hg{sup 0} oxidized while appearing to increase the removal of nitric oxide from the gas phase. We are currently testing the effects of variations in NOXSORB{trademark} concentration, sulfur dioxide concentration, nitric oxide concentration, and reaction time (residence time). Preliminary economic projections based on the results to date indicate that the chemical cost for nitric oxide oxidation could be less thanmore » $$5,000/ton removed, while for Hg{sup 0} oxidation it would be about $$20,000/lb removed.« less

Metabolic Implications of Peritoneal Dialysis in Patients with Acute Kidney Injury

PubMed Central

Góes, Cassiana Regina; Berbel, Marina Nogueira; Balbi, Andre Luis; Ponce, Daniela

2013-01-01

♦ Background: Peritoneal dialysis (PD) is a treatment for selected acute kidney injury patients (AKI), but little is known about its metabolic implications. The aim of the present study was to evaluate the metabolic implications of glucose absorption, sodium removal, protein loss into the dialysate, and catabolism in AKI patients undergoing high-volume PD and to identify risk factors associated with those metabolic effects. ♦ Methods: A prospective cohort study over 18 consecutive months evaluated 208 sessions of high-volume PD performed in 31 AKI patients. One session of high-volume PD lasted 24 hours. Repeated-measures analysis was performed, and correlations were calculated using the Spearman test for continuous variables and generalized linear models for categorical variables. ♦ Results: Glucose absorption remained at approximately 35.3% ± 10.5% per session. Protein loss measured 4.2 ± 6.1 g daily, with higher values initially, which declined significantly after 2 sessions. Nitrogen balance (NB) was initially negative, but stabilized at approximately zero after 3 sessions. Glucose uptake was positively correlated with the Acute Tubular Necrosis Individual Severity Score [ATNISS (r = 0.21, p = 0.0036)], C-reactive protein (r = 0.26, p = 0.0167), protein loss (r = 0.36, p < 0.0001), and sodium removal (r = 0.24, p = 0.002). Protein loss was positively correlated with sodium removal (r = 0.22, p = 0.0085) and gastrointestinal disease (p = 0.0004). Sodium removal was positively correlated with serum sodium (r = 0.21, p = 0.0064), ATNISS (r = 0.15, p = 0.0411), urea nitrogen appearance [UNA (r = 0.24, p = 0.0019)], and fluid overload as an indication for dialysis (p < 0.0001). Urea nitrogen appearance was positively correlated with the indication for dialysis (electrolyte disturbances: p = 0.0287) and negatively correlated with nephrotoxic AKI (p < 0.0001). Nitrogen balance was negatively correlated with UNA (r = -0.389, p < 0.0001) and ischemic AKI (p = 0.0047). ♦ Conclusions: High-volume PD did not increase hypercatabolism in AKI patients, and protein loss and glucose uptake remained constant during treatment. Those parameters were influenced by the clinical condition of the patients, including the cause of AKI, inflammation, and comorbidities—factors that should be known before the prescription of dialysis and nutrition, thus avoiding metabolic complications such as hyperglycemia, hypernatremia, and worsening catabolism. PMID:24335124

3D printed glass: surface finish and bulk properties as a function of the printing process

NASA Astrophysics Data System (ADS)

Klein, Susanne; Avery, Michael P.; Richardson, Robert; Bartlett, Paul; Frei, Regina; Simske, Steven

2015-03-01

It is impossible to print glass directly from a melt, layer by layer. Glass is not only very sensitive to temperature gradients between different layers but also to the cooling process. To achieve a glass state the melt, has to be cooled rapidly to avoid crystallization of the material and then annealed to remove cooling induced stress. In 3D-printing of glass the objects are shaped at room temperature and then fired. The material properties of the final objects are crucially dependent on the frit size of the glass powder used during shaping, the chemical formula of the binder and the firing procedure. For frit sizes below 250 μm, we seem to find a constant volume of pores of less than 5%. Decreasing frit size leads to an increase in the number of pores which then leads to an increase of opacity. The two different binders, 2- hydroxyethyl cellulose and carboxymethylcellulose sodium salt, generate very different porosities. The porosity of samples with 2-hydroxyethyl cellulose is similar to frit-only samples, whereas carboxymethylcellulose sodium salt creates a glass foam. The surface finish is determined by the material the glass comes into contact with during firing.

PROCESSING OF NEUTRON-IRRADIATED URANIUM

DOEpatents

Hopkins, H.H. Jr.

1960-09-01

An improved "Purex" process for separating uranium, plutonium, and fission products from nitric acid solutions of neutron-irradiated uranium is offered. Uranium is first extracted into tributyl phosphate (TBP) away from plutonium and fission products after adjustment of the acidity from 0.3 to 0.5 M and heating from 60 to 70 deg C. Coextracted plutonium, ruthenium, and fission products are fractionally removed from the TBP by three scrubbing steps with a 0.5 M nitric acid solution of ferrous sulfamate (FSA), from 3.5 to 5 M nitric acid, and water, respectively, and the purified uranium is finally recovered from the TBP by precipitation with an aqueous solution of oxalic acid. The plutonium in the 0.3 to 0.5 M acid solution is oxidized to the tetravalent state with sodium nitrite and extracted into TBP containing a small amount of dibutyl phosphate (DBP). Plutonium is then back-extracted from the TBP-DBP mixture with a nitric acid solution of FSA, reoxidized with sodium nitrite in the aqueous strip solution obtained, and once more extracted with TBP alone. Finally the plutonium is stripped from the TBP with dilute acid, and a portion of the strip solution thus obtained is recycled into the TBPDBP for further purification.

Active control of nanolitre droplet contents with convective concentration gradients across permeable walls.

PubMed

Zeitoun, Ramsey I; Goudie, Marcus J; Zwier, Jacob; Mahawilli, David; Burns, Mark A

2011-12-07

Nanolitre droplets in microfluidic devices can be used to perform thousands of independent chemical and biological experiments while minimizing reagents, cost and time. However, the absence of simple and versatile methods capable of controlling the contents of these nanolitre chemical systems limits their scientific potential. To address this, we have developed a method that is simple to fabricate and can continuously control nanolitre chemical systems by integrating a time-resolved convective flow signal across a permeable membrane wall. With this method, we can independently control the volume and concentration of nanolitre-sized drops without ever directly contacting the fluid. Transport occurring in these systems was also analyzed and thoroughly characterized. We achieved volumetric fluid introduction and removal rates ranging from 0.23 to 4.0 pL s(-1). Furthermore, we expanded this method to perform chemical processes. We precipitated silver chloride using a flow signal of sodium chloride and silver nitrate droplets. From there, we were able to separate sodium chloride reactants with a water flow signal, and dissolve silver chloride solids with an ammonia hydroxide flow signal. Finally, we demonstrate the potential to deliver large molecules and perform physical processes like crystallization and particle packing.

Interaction between the Pore and a Fast Gate of the Cardiac Sodium Channel

PubMed Central

Townsend, Claire; Horn, Richard

1999-01-01

Permeant ions affect a fast gating process observed in human cardiac sodium channels (Townsend, C., H.A. Hartmann, and R. Horn. 1997. J. Gen. Physiol. 110:11–21). Removal of extracellular permeant ions causes a reduction of open probability at positive membrane potentials. These results suggest an intimate relationship between the ion-conducting pore and the gates of the channel. We tested this hypothesis by three sets of manipulations designed to affect the binding of cations within the pore: application of intracellular pore blockers, mutagenesis of residues known to contribute to permeation, and chemical modification of a native cysteine residue (C373) near the extracellular mouth of the pore. The coupling between extracellular permeant ions and this fast gating process is abolished both by pore blockers and by a mutation that severely affects selectivity. A more superficial pore mutation or chemical modification of C373 reduces single channel conductance while preserving both selectivity of the pore and the modulatory effects of extracellular cations. Our results demonstrate a modulatory gating role for a region deep within the pore and suggest that the structure of the permeation pathway is largely preserved when a channel is closed. PMID:9925827

Does endodontic post space irrigation affect smear layer removal and bonding effectiveness?

PubMed

Gu, Xin-Hua; Mao, Cai-Yun; Liang, Cong; Wang, Hui-Ming; Kern, Matthias

2009-10-01

The effect of different post space irrigants on smear layer removal and dentin bond strength was evaluated. Sixty-six extracted sound maxillary central incisors were endodontically treated. After post space preparation, the teeth were assigned to three groups of 22 teeth each. The teeth of these three groups were irrigated for 1 min with 17% ethylenediaminetetracetic acid (EDTA) (group 1), 5.25% sodium hypochlorite (NaOCl) (group 2), or 0.9% sodium chloride (NaCl) (group 3). In each group, eight specimens were split longitudinally for smear layer evaluation, and the other fourteen specimens were filled with a self-etching adhesive system (Panavia F). Four of 14 specimens of each group were prepared for evaluation of the resin-dentin interdiffusion zone (RDIZ) and resin tags, and the other 10 specimens were serially sectioned for push-out test analysis. Smear layer removal and bond strength were affected by different post space irrigants. EDTA removed the smear layer extremely effectively and, as a result, improved the bond strength at each region (apical, middle, and coronal) of the roots. Resin tag formation and the RDIZ were also affected by different irrigants and in accordance with bond strength. Therefore, removal of the smear layer use a self-etching luting system plays an important role in bonding effectiveness.

SOXAL{trademark} pilot plant demonstration at Niagara Mohawk`s Dunkirk Station

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

Strangway, P.K.

This paper describes a six-month, nominal three megawatt (3 MW) pilot plant demonstration of the SOXAL{trademark} regenerative flue gas desulfurization (FGD) process at Niagara Mohawk Power Corporation`s Dunkirk, NY coal-fired power station. Using a slip-stream of flue gas from an actual coal-fired boiler, the pilot plant successfully demonstrated the absorption of sulfur dioxide and the simultaneous regeneration of sodium-based scrubbing liquor via bipolar membrane electrodialysis. Sulfur dioxide removal efficiency of greater than 98% was routinely achieved. The absorption and regeneration stages were both proven reliable and controllable. The pilot plant was successfully operated in both continuous and decoupled modes ofmore » operation, thus demonstrating the flexibility of this process.« less

Bicarbonate absorption by rabbit cortical collecting tubules in vitro.

PubMed

McKinney, T D; Burg, M B

1978-02-01

The rate of transport of bicarbonate was studied in isolated perfused rabbit cortical collecting tubules that were absorbing bicarbonate in vitro. Acetazolamide completely inhibited bicarbonate absorption, as was previously observed with isolated proximal tubules. Therefore, carbonic anhydrase probably is important for bicarbonate absorption in both the proximal tubules and collecting tubules. Inhibition of sodium transport by ouabain or elimination of its transport by completely removing the sodium did not cause a decrease in bicarbonate absorption by the collecting tubules. We previously found that inhibition of sodium transport caused a great decrease in bicarbonate absorption by proximal tubules. Therefore, absorption of bicarbonate is not directly related to sodium transport in collecting tubules, but it probably is related to sodium transport in isolated perfused rabbit proximal tubules. Amiloride inhibited bicarbonate absorption by the collecting tubules consistent with previous observations that the drug inhibits urinary acidification. Although amiloride also inhibits sodium transport and reduces the transepithelial voltage across the collecting tubules, the effect of the drug on bicarbonate transport apparently is independent of the other effects.

Synthesis, characterization, swelling and dye adsorption properties of starch incorporated acrylic gels.

PubMed

Mandal, Bidyadhar; Ray, Samit Kumar

2015-11-01

Several hydrogels were prepared by a free radical polymerization of acrylic acid (AA), sodium acrylate (SA) and AA/hydroxy ethyl methacrylate (HEMA) in the presence of starch in water. These starch incorporated acrylic gels were prepared by varying the concentration of the initiator, monomer, crosslinker and the starch. The resulting gels were characterized by FTIR, SEM, XRD, DTA-TGA, pH at point zero charge (PZC), swelling and the diffusion in water. The gels showed high adsorption and removal% of Safranine T (ST) and Brilliant Cresyl Blue (BCB) dyes from water. The swelling and the adsorption data were fitted to different kinetic models and isotherms. Amongst the three kinds of gels, the starch incorporated sodium polyacrylate gel showed the highest adsorption of 9.7-85.3mg/L (97-61% removal) of BCB dye and 9.1-83mg/L (91-60% removal) of ST dye for a feed dye concentration of 10-140mg/L. Copyright © 2015 Elsevier B.V. All rights reserved.

Immobilization of ammonia-oxidizing bacteria by polyvinyl alcohol and sodium alginate.

PubMed

Dong, Yuwei; Zhang, Yanqiu; Tu, Baojun

Ammonia-oxidizing bacteria were immobilized by polyvinyl alcohol (PVA) and sodium alginate. The immobilization conditions and ammonia oxidation ability of the immobilized bacteria were investigated. The following immobilization conditions were observed to be optimal: PVA, 12%; sodium alginate, 1.1%; calcium chloride, 1.0%; inoculum concentration, 1.3 immobilized balls/mL of immobilized medium; pH, 10; and temperature, 30°C. The immobilized ammonia-oxidizing bacteria exhibited strong ammonia oxidation ability even after being recycled four times. The ammonia nitrogen removal rate of the immobilized ammonia-oxidizing bacteria reached 90.30% under the optimal immobilization conditions. When compared with ammonia-oxidizing bacteria immobilized by sodium alginate alone, the bacteria immobilized by PVA and sodium alginate were superior with respect to pH resistance, the number of reuses, material cost, heat resistance, and ammonia oxidation ability. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

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

Harvey, Steven P.; Aguiar, Jeffery A.; Hacke, Peter

Here, we investigated potential-induced degradation (PID) in silicon mini-modules that were subjected to accelerated stressing to induce PID conditions. Shunted areas on the cells were identified with photoluminescence and dark lock-in thermography (DLIT) imaging. The identical shunted areas were then analyzed via time-of-flight secondary-ion mass spectrometry (TOFSIMS) imaging, 3-D tomography, and high-resolution transmission electron microscopy. The TOF-SIMS imaging indicates a high concentration of sodium in the shunted areas, and 3-D tomography reveals that the sodium extends more than 2 um from the surface below shunted regions. Transmission electron microscopy investigation reveals that a stacking fault is present at an areamore » identified as shunted by DLIT imaging. After the removal of surface sodium, tomography reveals persistent sodium present around the junction depth of 300 nm and a drastic difference in sodium content at the junction when comparing shunted and nonshunted regions.« less

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

Richard D. Boardman; B. H. O'Brien; N. R. Soelberg

About one million gallons of acidic, hazardous, and radioactive sodium-bearing waste are stored in stainless steel tanks at the Idaho Nuclear Technology and Engineering Center (INTEC), which is a major operating facility of the Idaho National Engineering and Environmental Laboratory. Calcination at high-temperature conditions (600 C, with alumina nitrate and calcium nitrate chemical addition to the feed) is one of four options currently being considered by the Department of Energy for treatment of the remaining tank wastes. If calcination is selected for future processing of the sodium-bearing waste, it will be necessary to install new off-gas control equipment in themore » New Waste Calcining Facility (NWCF) to comply with the Maximum Achievable Control Technology (MACT) standards for hazardous waste combustors and incinerators. This will require, as a minimum, installing a carbon bed to reduce mercury emissions from their current level of up to 7,500 to <45 {micro}g/dscm, and a staged combustor to reduce unburned kerosene fuel in the off-gas discharge to <100 ppm CO and <10 ppm hydrocarbons. The staged combustor will also reduce NOx concentrations of about 35,000 ppm by 90-95%. A pilot-plant calcination test was completed in a newly constructed 15-cm diameter calciner vessel. The pilot-plant facility was equipped with a prototype MACT off-gas control system, including a highly efficient cyclone separator and off-gas quench/venturi scrubber for particulate removal, a staged combustor for unburned hydrocarbon and NOx destruction, and a packed activated carbon bed for mercury removal and residual chloride capture. Pilot-plant testing was performed during a 50-hour system operability test January 14-16, followed by a 100-hour high-temperature calcination pilot-plant calcination run January 19-23. Two flowsheet blends were tested: a 50-hour test with an aluminum-to-alkali metal molar ratio (AAR) of 2.25, and a 50-hour test with an AAR of 1.75. Results of the testing indicate that sodium-bearing waste can be successfully calcined at 600 C with an AAR of 1.75. Unburned hydrocarbons are reduced to less than 10 ppm (7% O2, dry basis), with >90% reduction of NOx emissions. Mercury removal by the carbon bed reached 99.99%, surpassing the control efficiency needed to meet MACT emissions standards. No deleterious impacts on the carbon bed were observed during the tests. The test results imply that upgrading the NWCF calciner with a more efficient cyclone separator and the proposed MACT equipment can process the remaining tanks wastes in 3 years or less, and comply with the MACT standards.« less

Frequency-dependent reliability of spike propagation is function of axonal voltage-gated sodium channels in cerebellar Purkinje cells.

PubMed

Yang, Zhilai; Wang, Jin-Hui

2013-12-01

The spike propagation on nerve axons, like synaptic transmission, is essential to ensure neuronal communication. The secure propagation of sequential spikes toward axonal terminals has been challenged in the neurons with a high firing rate, such as cerebellar Purkinje cells. The shortfall of spike propagation makes some digital spikes disappearing at axonal terminals, such that the elucidation of the mechanisms underlying spike propagation reliability is crucial to find the strategy of preventing loss of neuronal codes. As the spike propagation failure is influenced by the membrane potentials, this process is likely caused by altering the functional status of voltage-gated sodium channels (VGSC). We examined this hypothesis in Purkinje cells by using pair-recordings at their somata and axonal blebs in cerebellar slices. The reliability of spike propagation was deteriorated by elevating spike frequency. The frequency-dependent reliability of spike propagation was attenuated by inactivating VGSCs and improved by removing their inactivation. Thus, the functional status of axonal VGSCs influences the reliability of spike propagation.

Novelties of combustion synthesized titania ultrafiltration membrane in efficient removal of methylene blue dye from aqueous effluent.

PubMed

Doke, Suresh M; Yadav, Ganapati D

2014-12-01

In this study, titania nanoparticles were synthesized by combustion and used to make ultrafiltration membrane. Characteristics of titania membranes such as textural evaluation, surface morphology, pure water permeability and protein rejection were investigated. Titania membrane sintered at 450 °C showed pure water permeability 11 × 10−2 L h−1 m−2 kPa−1 and 76% protein rejection. The membrane presented good water flux and retention properties with regards to protein and methylene blue dye. Ultrafiltration process was operated at lower pressure (100 kPa) and showed 99% removal of methylene blue using adsorptive micellar flocculation at sodium dodecyl sulfate concentration below its critical micellar concentration. Ferric chloride was used as the coagulant. The method of making titania membrane and its use are new. These studies can be extended to other dyes and pollutants.

[Determination of Butroxydim in Agricultural Products by LC-MS].

PubMed

Minatani, Tomiaki; Nagai, Hiroyuki; Tada, Hiroyuki; Goto, Kotaro; Nemoto, Satoru

2015-01-01

An analytical method for the determination of butroxydim in agricultural products by LC-MS was developed. Butroxydim was extracted with acetonitrile and an aliquot of the crude extract was cleaned up on an octadecyl silanized silica gel (C18) cartridge column (1,000 mg), followed by a salting-out step to remove water. Before purification on a silica gel (SI) cartridge column (690 mg), polar matrices were precipitated by adding ethyl acetate, n-hexane and anhydrous sodium sulfate successively. This process effectively removed caffeine and catechins and improved recovery when analyzing residual butroxydim in tea leaves. Recovery and repeatability were good; the relative standard deviations were less than 5% for all 12 tested agricultural products (brown rice, soybean, potato, spinach, cabbage, apple, orange, grapefruit, lemon, tomato, peas with pods, and tea). Average recoveries for 11 agricultural products, except for lemon, were 74-92%.

Changes in the Sodium Content of Australian Processed Foods between 1980 and 2013 Using Analytical Data

PubMed Central

Zganiacz, Felicity; Wills, Ron B. H.; Mukhopadhyay, Soumi Paul; Arcot, Jayashree; Greenfield, Heather

2017-01-01

The objective of this study was to obtain analytical data on the sodium content of a range of processed foods and compare the levels obtained with their label claims and with published data of the same or equivalent processed foods in the 1980s and 1990s to investigate the extent of any change in sodium content in relation to reformulation targets. The sodium contents of 130 Australian processed foods were obtained by inductively coupled plasma optical emission spectrometry (ICP-OES) analysis and compared with previously published data. The sodium content between 1980 and 2013 across all products and by each product category were compared. There was a significant overall sodium reduction of 23%, 181 mg/100 g (p <0.001, 95% CI (Confidence Interval), 90 to 272 mg/100 g), in Australian processed foods since 1980, with a 12% (83 mg/100 g) reduction over the last 18 years. The sodium content of convenience foods (p < 0.001, 95% CI, 94 to 291 mg/100 g) and snack foods (p = 0.017, 95% CI, 44 to 398 mg/100 g) had declined significantly since 1980. Meanwhile, the sodium contents of processed meats (p = 0.655, 95% CI, −121 to 190) and bread and other bakery products (p = 0.115, 95% CI, −22 to 192) had decreased, though not significantly. Conversely, the sodium content of cheese (p = 0.781, 95% CI, −484 to 369 mg/100 g) had increased but also not significantly. Of the 130 products analysed, 62% met Australian reformulation targets. Sodium contents of the processed foods and the overall changes in comparison with previous data indicate a decrease over the 33 years period and suggest that the Australian recommended reformulation targets have been effective. Further sodium reduction of processed foods is still required and continuous monitoring of the reduction of sodium levels in processed foods is needed. PMID:28505147

Changes in the Sodium Content of Australian Processed Foods between 1980 and 2013 Using Analytical Data.

PubMed

Zganiacz, Felicity; Wills, Ron B H; Mukhopadhyay, Soumi Paul; Arcot, Jayashree; Greenfield, Heather

2017-05-15

The objective of this study was to obtain analytical data on the sodium content of a range of processed foods and compare the levels obtained with their label claims and with published data of the same or equivalent processed foods in the 1980s and 1990s to investigate the extent of any change in sodium content in relation to reformulation targets. The sodium contents of 130 Australian processed foods were obtained by inductively coupled plasma optical emission spectrometry (ICP-OES) analysis and compared with previously published data. The sodium content between 1980 and 2013 across all products and by each product category were compared. There was a significant overall sodium reduction of 23%, 181 mg/100 g ( p <0.001, 95% CI (Confidence Interval), 90 to 272 mg/100 g), in Australian processed foods since 1980, with a 12% (83 mg/100 g) reduction over the last 18 years. The sodium content of convenience foods ( p < 0.001, 95% CI, 94 to 291 mg/100 g) and snack foods ( p = 0.017, 95% CI, 44 to 398 mg/100 g) had declined significantly since 1980. Meanwhile, the sodium contents of processed meats ( p = 0.655, 95% CI, -121 to 190) and bread and other bakery products ( p = 0.115, 95% CI, -22 to 192) had decreased, though not significantly. Conversely, the sodium content of cheese ( p = 0.781, 95% CI, -484 to 369 mg/100 g) had increased but also not significantly. Of the 130 products analysed, 62% met Australian reformulation targets. Sodium contents of the processed foods and the overall changes in comparison with previous data indicate a decrease over the 33 years period and suggest that the Australian recommended reformulation targets have been effective. Further sodium reduction of processed foods is still required and continuous monitoring of the reduction of sodium levels in processed foods is needed.

Changes in sodium levels in processed and restaurant foods, 2005 to 2011.

PubMed

Jacobson, Michael F; Havas, Stephen; McCarter, Robert

2013-07-22

Excess consumption of sodium is an important cause of hypertension, a major risk factor for heart disease and stroke. The higher the level of consumption, the greater is a person's likelihood of developing hypertension. Numerous organizations have recommended reductions in sodium intake in the United States. Roughly 80% of the sodium consumed by Americans has been added by food manufacturers and restaurants. To compare the mean (SD) levels of sodium for identical products ascertained in 2005, 2008, and 2011. Comparison study in an academic research setting. Center for Science in the Public Interest staff have monitored sodium levels in selected processed foods and fast-food restaurant foods for many years. The sodium content in identical foods, as measured in 2005, 2008, and 2011. Between 2005 and 2011, the sodium content in 402 processed foods declined by approximately 3.5%, while the sodium content in 78 fast-food restaurant products increased by 2.6%. Although some products showed decreases of at least 30%, a greater number of products showed increases of at least 30%. The predominant finding is the absence of any appreciable or statistically significant changes in sodium content during 6 years. Based on our sample, reductions in sodium levels in processed and restaurant foods are inconsistent and slow. These findings are in accord with other data indicating the slow pace of voluntary reductions in sodium levels in processed and restaurant foods. Stronger action (eg, phased-in limits on sodium levels set by the federal government) is needed to lower sodium levels and reduce the prevalence of hypertension and cardiovascular diseases.

N2O production in the Fe(II)(EDTA)-NO reduction process: the effects of carbon source and pH.

PubMed

Chen, Jun; Wang, Lei; Zheng, Ji; Chen, Jianmeng

2015-07-01

Chemical absorption-biological reduction (BioDeNOx), which uses Fe(II)(EDTA) as a complexing agent for promoting the mass transfer efficiency of NO from gas to water, is a promising technology for removing nitric oxide (NO) from flue gases. The carbon source and pH are important parameters for Fe(II)(EDTA)-NO (the production of absorption) reduction and N2O emissions from BioDeNOx systems. Batch tests were performed to evaluate the effects of four different carbon sources (i.e., methanol, ethanol, sodium acetate, and glucose) on Fe(II)(EDTA)-NO reduction and N2O emissions at an initial pH of 7.2 ± 0.2. The removal efficiency of Fe(II)(EDTA)-NO was 93.9%, with a theoretical rate of 0.77 mmol L(-1) h(-1) after 24 h of operation. The highest N2O production was 0.025 mmol L(-1) after 3 h when glucose was used as the carbon source. The capacities of the carbon sources to enhance the activity of the Fe(II)(EDTA)-NO reductase enzyme decreased in the following order based on the C/N ratio: glucose > ethanol > sodium acetate > methanol. Over the investigated pH range of 5.5-8.5, the Fe(II)(EDTA)-NO removal efficiency was highest at a pH of 7.5, with a theoretical rate of 0.88 mmol L(-1) h(-1). However, the N2O production was lowest at a pH of 8.5. The primary effect of pH on denitrification resulted from the inhibition of nosZ in acidic conditions.

The impact of detergents on the tissue decellularization process: A ToF-SIMS study.

PubMed

White, Lisa J; Taylor, Adam J; Faulk, Denver M; Keane, Timothy J; Saldin, Lindsey T; Reing, Janet E; Swinehart, Ilea T; Turner, Neill J; Ratner, Buddy D; Badylak, Stephen F

2017-03-01

Biologic scaffolds are derived from mammalian tissues, which must be decellularized to remove cellular antigens that would otherwise incite an adverse immune response. Although widely used clinically, the optimum balance between cell removal and the disruption of matrix architecture and surface ligand landscape remains a considerable challenge. Here we describe the use of time of flight secondary ion mass spectroscopy (ToF-SIMS) to provide sensitive, molecular specific, localized analysis of detergent decellularized biologic scaffolds. We detected residual detergent fragments, specifically from Triton X-100, sodium deoxycholate and sodium dodecyl sulphate (SDS) in decellularized scaffolds; increased SDS concentrations from 0.1% to 1.0% increased both the intensity of SDS fragments and adverse cell outcomes. We also identified cellular remnants, by detecting phosphate and phosphocholine ions in PAA and CHAPS decellularized scaffolds. The present study demonstrates ToF-SIMS is not only a powerful tool for characterization of biologic scaffold surface molecular functionality, but also enables sensitive assessment of decellularization efficacy. We report here on the use of a highly sensitive analytical technique, time of flight secondary ion mass spectroscopy (ToF-SIMS) to characterize detergent decellularized scaffolds. ToF-SIMS detected cellular remnants and residual detergent fragments; increased intensity of the detergent fragments correlated with adverse cell matrix interactions. This study demonstrates the importance of maintaining a balance between cell removal and detergent disruption of matrix architecture and matrix surface ligand landscape. This study also demonstrates the power of ToF-SIMS for the characterization of decellularized scaffolds and capability for assessment of decellularization efficacy. Future use of biologic scaffolds in clinical tissue reconstruction will benefit from the fundamental results described in this work. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Effectiveness of root canal debris removal using passive ultrasound irrigation with chlorhexidine digluconate or sodium hypochlorite individually or in combination as irrigants.

PubMed

Ferreira, Rafael Brandao; Marchesan, Melissa Andreia; Silva-Sousa, Yara Teresinha; Sousa-Neto, Manoel

2008-07-01

The aim of this in vitro study was to evaluate the cleaning capacity of different auxiliary chemical substances energized with ultrasound in radicular dentin using morphologic analysis. Twenty-eight single-canal, mandibular incisors were prepared with the Hero 642 canal preparation system following the sequence: 25/12, 30/06, 35/02, and 40/02, 1 mm from the apex. The specimens were then divided into four groups of seven teeth. During biomechanical preparation the teeth were irrigated with 2 ml of distilled water between files. Each group of specimens (n=7) received a final irrigation with 100 ml of the following irrigants that were activated with ultrasound for 3 minutes: Group 1- distilled water; Group 2- 0.2% chlorhexidine digluconate (CHX); Group 3- 2.5% sodium hypochlorite (NaOCl); and Group 4-the filtrate obtained after combining 0.2% CHX and 2.5% NaOCl. The apical portions of the root canals from each group were then submitted to histological processing and analyzed using optical microscopy. Results showed statistical differences between the groups (p<0.01). Groups 1 and 2 (distilled water and 0.2% CHX respectively) were statistically similar in terms of a greater amount of debris, whereas 2.5% NaOCl and the filtrate were more efficient in removal of debris. There is no additional benefit in terms of debris removal from root canal walls by irrigating with the filtrate obtained from the combination of NaOCl and CHX when compared to using NaOCl alone. The findings of this study suggest the time and expense of preparing and using a combination of NaOCl and CHX is not warranted compared to using NaOCl alone for root canal irrigation.

Three years experience of operating and selling recovered struvite from full-scale plant.

PubMed

Ueno, Y; Fujii, M

2001-11-01

The adoption of phosphorus removal at sewage treatment works (STW) creates two main problems. Firstly large amounts of sludge are produced and secondly the quantity of the effluent deteriorates due to the increase in the phosphorus load of the sidestream. Furthermore, these processes do not remove phosphorus in a form that would enable it to be recycled. Therefore in order to control these process difficulties and produce a recyclable phosphorus product a sidestream struvite crystallisation reactor was developed. The struvite was produced in a fluidised bed reactor using dewatered filtrate from anaerobic sludge digestion. Magnesium hydroxide was added in a magnesium to phosphate ratio of 1:1 and the pH was adjusted to between 8.2-8.8 with the addition of sodium hydroxide. A retention time of 10 days alowed the growth of pellets between 0.5-1.0 mm in size. The recovered struvite contained only minute traces of toxic substances and was sold to fertiliser companies for 27,000 yen tonne(-1). It is used to enhance existing fertilisers, which are widely used on paddy rice, vegetables and flowers.

Contribution of a Sodium Ion Gradient to Energy Conservation during Fermentation in the Cyanobacterium Arthrospira (Spirulina) maxima CS-328 ▿ †

PubMed Central

Carrieri, Damian; Ananyev, Gennady; Lenz, Oliver; Bryant, Donald A.; Dismukes, G. Charles

2011-01-01

Sodium gradients in cyanobacteria play an important role in energy storage under photoautotrophic conditions but have not been well studied during autofermentative metabolism under the dark, anoxic conditions widely used to produce precursors to fuels. Here we demonstrate significant stress-induced acceleration of autofermentation of photosynthetically generated carbohydrates (glycogen and sugars) to form excreted organic acids, alcohols, and hydrogen gas by the halophilic, alkalophilic cyanobacterium Arthrospira (Spirulina) maxima CS-328. When suspended in potassium versus sodium phosphate buffers at the start of autofermentation to remove the sodium ion gradient, photoautotrophically grown cells catabolized more intracellular carbohydrates while producing 67% higher yields of hydrogen, acetate, and ethanol (and significant amounts of lactate) as fermentative products. A comparable acceleration of fermentative carbohydrate catabolism occurred upon dissipating the sodium gradient via addition of the sodium-channel blocker quinidine or the sodium-ionophore monensin but not upon dissipating the proton gradient with the proton-ionophore dinitrophenol (DNP). The data demonstrate that intracellular energy is stored via a sodium gradient during autofermentative metabolism and that, when this gradient is blocked, the blockage is compensated by increased energy conversion via carbohydrate catabolism. PMID:21890670

0.9% sodium chloride injection with and without heparin for maintaining peripheral indwelling intermittent-infusion devices in infants.

PubMed

Nelson, T J; Graves, S M

1998-03-15

The use of 0.9% sodium chloride injection with and without heparin sodium for maintaining peripheral indwelling intermittent-infusion devices (PIIIDs) in infants was studied. In this double-blind study, children up to one year of age who had a 24-gauge PIIID through which a continuous i.v. infusion was no longer running were randomly assigned to have their PIIID capped with 0.9% sodium chloride injection with or without heparin sodium 10 units/mL. PIIIDs were capped every eight hours if no medications were administered; otherwise, they were capped after each dose of an i.v. drug. The heparin group had 26 patients with 28 evaluable PIIIDs, and the 0.9% sodium chloride injection group had 32 patients with 46 evaluable PIIIDs. The two groups did not differ significantly in variables assessing the duration of PIIID use, reasons for removal of PIIIDs, mean number of cappings, irritant potential of administered drugs, or severity of medication-related irritation. There was no significant difference between 0.9% sodium chloride injection with and without heparin sodium 10 units/mL in maintaining 24-gauge PIIIDs in children younger than one year.

Veratric acid removal from water by electrochemical oxidation on BDD anode

NASA Astrophysics Data System (ADS)

Jum'h, Inshad; Abdelhay, Arwa; Telfah, Ahmad; Al-Akhras, M.-Ali; Al-Kazwini, Akeel; Rosiwal, Stefan

2018-02-01

The efficiency of boron doped diamond (BDD) in the electrochemical treatment of synthetically contaminated water with veratric acid (VA), one kind of polyphenolic type compounds, is investigated in this work. A BDD electrode was practically fabricated using hot filament chemical vapor deposition (HFCVD). Later on, the BDD electrode was implemented as an anode in a batch electrolytic reactor. The effect of operating factors such as the initial concentration of VA, NaCl addition, and supporting electrolyte type (H2SO4, H3PO4 and Na2SO4) was studied. The chemical oxygen demand (COD) measurements were conducted to study the VA electrolysis kinetics. The experimental data suggested that sodium sulfate was the best supporting electrolyte as the COD removal reached a percentage of 100% using 1 mmol/dm3 as VA concentration. The kinetics of the COD decay of the VA electrolysis were found to obey the pseudo-first order model. Remarkably, the electrolysis process is significantly speeded up once chloride is added to the reaction. The complete COD removal was achieved in 60 minutes of treatment.

Evaluating the effect of different draw solutes in a baffled osmotic membrane bioreactor-microfiltration using optical coherence tomography with real wastewater.

PubMed

Pathak, Nirenkumar; Fortunato, Luca; Li, Sheng; Chekli, Laura; Phuntsho, Sherub; Ghaffour, Noreddine; Leiknes, TorOve; Shon, Ho Kyong

2018-05-02

This study investigated the performance of an integrated osmotic and microfiltration membrane bioreactor for real sewage employing baffles in the reactor. To study the biofouling development on forward osmosis membranes optical coherence tomography (OCT) technique was employed. On-line monitoring of biofilm growth on a flat sheet cellulose triacetate forward osmosis (CTA-FO) membrane was conducted for 21 days. Further, the process performance was evaluated in terms of water flux, organic and nutrient removal, microbial activity in terms of soluble microbial products (SMP) and extracellular polymeric substance (EPS), and floc size. The measured biofouling layer thickness was in the order sodium chloride (NaCl) > ammonium sulfate (SOA) > potassium dihydrogen phosphate (KH 2 PO 4 ). Very high organic removal (96.9 ± 0.8%) and reasonably good nutrient removal efficiency (85.2 ± 1.6% TN) was achieved. The sludge characteristics and biofouling layer thickness suggest that less EPS and higher floc size were the governing factors for less fouling. Copyright © 2018 Elsevier Ltd. All rights reserved.

Biofilm characteristics and evaluation of the sanitation procedures of thermophilic Aeribacillus pallidus E334 biofilms.

PubMed

Kilic, Tugba; Karaca, Basar; Ozel, Beste Piril; Ozcan, Birgul; Cokmus, Cumhur; Coleri Cihan, Arzu

2017-04-01

The ability of Aeribacillus pallidus E334 to produce pellicle and form a biofilm was studied. Optimal biofilm formation occurred at 60 °C, pH 7.5 and 1.5% NaCl. Extra polymeric substances (EPS) were composed of proteins and eDNA (21.4 kb). E334 formed biofilm on many surfaces, but mostly preferred polypropylene and glass. Using CLSM analysis, the network-like structure of the EPS was observed. The A. pallidus biofilm had a novel eDNA content. DNaseI susceptibility (86.8% removal) of eDNA revealed its importance in mature biofilms, but the purified eDNA was resistant to DNaseI, probably due to its extended folding outside the matrix. Among 15 cleaning agents, biofilms could be removed with alkaline protease and sodium dodecyl sulphate (SDS). The removal of cells from polypropylene and biomass on glass was achieved with combined SDS/alkaline protease treatment. Strong A. pallidus biofilms could cause risks for industrial processes and abiotic surfaces must be taken into consideration in terms of sanitation procedures.

Nuclear criticality safety bounding analysis for the in-tank-precipitation (ITP) process, impacted by fissile isotopic weight fractions

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

Bess, C.E.

The In-Tank Precipitation process (ITP) receives High Level Waste (HLW) supernatant liquid containing radionuclides in waste processing tank 48H. Sodium tetraphenylborate, NaTPB, and monosodium titanate (MST), NaTi{sub 2}O{sub 5}H, are added for removal of radioactive Cs and Sr, respectively. In addition to removal of radio-strontium, MST will also remove plutonium and uranium. The majority of the feed solutions to ITP will come from the dissolution of supernate that had been concentrated by evaporation to a crystallized salt form, commonly referred to as saltcake. The concern for criticality safety arises from the adsorption of U and Pt onto MST. If sufficientmore » mass and optimum conditions are achieved then criticality is credible. The concentration of u and Pt from solution into the smaller volume of precipitate represents a concern for criticality. This report supplements WSRC-TR-93-171, Nuclear Criticality Safety Bounding Analysis For The In-Tank-Precipitation (ITP) Process. Criticality safety in ITP can be analyzed by two bounding conditions: (1) the minimum safe ratio of MST to fissionable material and (2) the maximum fissionable material adsorption capacity of the MST. Calculations have provided the first bounding condition and experimental analysis has established the second. This report combines these conditions with canyon facility data to evaluate the potential for criticality in the ITP process due to the adsorption of the fissionable material from solution. In addition, this report analyzes the potential impact of increased U loading onto MST. Results of this analysis demonstrate a greater safety margin for ITP operations than the previous analysis. This report further demonstrates that the potential for criticality in the ITP process due to adsorption of fissionable material by MST is not credible.« less

Removal of metal ions from aqueous solutions using carboxymethyl cellulose/sodium styrene sulfonate gels prepared by radiation grafting.

PubMed

Tran, Thu Hong; Okabe, Hirotaka; Hidaka, Yoshiki; Hara, Kazuhiro

2017-02-10

Sodium Carboxymethyl Cellulose (CMCNa)/Sodium Styrene Sulfonate (SSS) hydrogels with grafted and crosslinked polymeric networks were prepared by γ-radiation at atmosphere condition. The obtained hydrogels were characterized by gel fraction, swelling ratio, TGA and FTIR spectroscopy. The results showed the ratio of CMC and SSS 1:0 gave the highest gel fraction, compared with other ratios. The swelling capacity increased by increasing SSS content due to the presence of SO 3 Na, OH groups in gel structure. The FTIR spectrum of CMC/SSS gel showed the new absorption peaks at 1034 and 1012cm -1 corresponds to SO 3 Na group. The metal ion adsorption capacity of CMC/SSS gel was investigated. The grafted gel effectively removed metal ions, especially Cr and Pb. The effects of hydrogel composition, contact time, and initial concentration on the adsorption capacity of the grafted hydrogels were studied. The adsorption kinetics and equilibrium isotherms were investigated using pseudo-second-order model and Langmuir model. Copyright © 2016. Published by Elsevier Ltd.

Studies Conducted of Sodium Carbonate Contaminant Found on the Wing Leading Edge and the Nose Cap of the Space Shuttle Orbiter

NASA Technical Reports Server (NTRS)

Jacobson, Nathan S.; Palou, Jaime J.

2003-01-01

In early 2001, three of the space shuttle orbiters were found to have a sodium carbonate contaminant on the wing leading edge and nose cap. These parts are made of a reinforced carbon/carbon material protected by silicon carbide (SiC) and a glass coating. The glass coating is known as Type A and is primarily sodium silicate with particles of SiC. NASA Glenn Research Center's Environmental Durability Branch was asked to determine the chemistry of this deposit formation and assess any possible detrimental effects. At low temperatures, the reverse reaction is favorable. Previous studies of the corrosion of glass show that carbon dioxide in the presence of water does form sodium carbonate on sodium silicate glass (ref. 1). It is quite likely that a similar scenario exists for the orbiter wing leading edge. All three orbiters that formed sodium carbonate were exposed to rain. This formation of sodium carbonate was duplicated in the laboratory. The Type A glass, which coats the wing leading edge and nose cap, was made in a freestanding form and exposed to water in two separate experiments. In one set of experiments, the coating was placed in a petri dish filled with water. As the water evaporated, sodium carbonate formed. In another case, water was slowly dripped on the coating and sodium carbonate formed. The sodium carbonate was detected by chemical analysis and, in some cases, xray diffraction showed a hydrated sodium carbonate. The next step was to examine possible detrimental effects of this sodium carbonate. There are three likely scenarios for the sodium carbonate deposit: (1) it may be removed with a simple rinse, (2) it may remain and flow back into the Type A glass after heating during reentry, or (3) it may remain and flow onto unprotected SiC and/or other parts after heating during reentry. The effect of case 1 is to remove the Na2O constituent from the Type A glass, thus decreasing its effectiveness as a sealant. Even so, overall, it is probably the best approach and was used by the NASA Kennedy Space Center when the deposits were first observed. The effect of case 2 is minimal and would actually restore the the Type A glass to its composition before carbonate formation. However, the problem with allowing the carbonate to remain leads to the third scenario, the deposit flowing onto other parts. A series of tests were conducted on unprotected SiC, and minimal effects were found in the short-term, but other ceramic and metal parts could be damaged by the molten sodium carbonate and would require close monitoring.

Comparison of Decontamination Efficacy of Cleaning Solutions on a Biological Safety Cabinet Workbench Contaminated by Cyclophosphamide

PubMed Central

Adé, Apolline; Chauchat, Laure; Frève, Johann-François Ouellette; Gagné, Sébastien; Caron, Nicolas; Bussières, Jean-François

2017-01-01

Background Several studies have compared cleaning procedures for decontaminating surfaces exposed to antineoplastic drugs. All of the cleaning products tested were successful in reducing most of the antineoplastic drug quantities spilled on surfaces, but none of them completely removed residual traces. Objective To assess the efficacy of various cleaning solutions for decontaminating a biological safety cabinet workbench exposed to a defined amount of cyclophosphamide. Methods In this pilot study, specific areas of 2 biological safety cabinets (class II, type B2) were deliberately contaminated with a defined quantity of cyclophosphamide (10 μg or 107 pg). Three cleaning solutions were tested: quaternary ammonium, sodium hypochlorite 0.02%, and sodium hypochlorite 2%. After cleaning, the cyclophosphamide remaining on the areas was quantified by wipe sampling. Each cleaning solution was tested 3 times, with cleaning and wipe sampling being performed 5 times for each test. Results A total of 57 wipe samples were collected and analyzed. The average recovery efficiency was 121.690% (standard deviation 5.058%). The decontamination efficacy increased with the number of successive cleaning sessions: from 98.710% after session 1 to 99.997% after session 5 for quaternary ammonium; from 97.027% to 99.997% for sodium hypochlorite 0.02%; and from 98.008% to 100% for sodium hypochlorite 2%. Five additional cleaning sessions performed after the main study (with detergent and sodium hypochlorite 2%) were effective to complete the decontamination, leaving no detectable traces of the drug. Conclusions All of the cleaning solutions reduced contamination of biological safety cabinet workbenches exposed to a defined amount of cyclophosphamide. Quaternary ammonium and sodium hypochlorite (0.02% and 2%) had mean efficacy greater than 97% for removal of the initial quantity of the drug (107 pg) after the first cleaning session. When sodium hypochlorite 2% was used, fewer cleaning sessions were required to complete decontamination. Further studies should be conducted to identify optimal cleaning strategies to fully eliminate traces of hazardous drugs. PMID:29298999

Control of reactor coolant flow path during reactor decay heat removal

DOEpatents

Hunsbedt, Anstein N.

1988-01-01

An improved reactor vessel auxiliary cooling system for a sodium cooled nuclear reactor is disclosed. The sodium cooled nuclear reactor is of the type having a reactor vessel liner separating the reactor hot pool on the upstream side of an intermediate heat exchanger and the reactor cold pool on the downstream side of the intermediate heat exchanger. The improvement includes a flow path across the reactor vessel liner flow gap which dissipates core heat across the reactor vessel and containment vessel responsive to a casualty including the loss of normal heat removal paths and associated shutdown of the main coolant liquid sodium pumps. In normal operation, the reactor vessel cold pool is inlet to the suction side of coolant liquid sodium pumps, these pumps being of the electromagnetic variety. The pumps discharge through the core into the reactor hot pool and then through an intermediate heat exchanger where the heat generated in the reactor core is discharged. Upon outlet from the heat exchanger, the sodium is returned to the reactor cold pool. The improvement includes placing a jet pump across the reactor vessel liner flow gap, pumping a small flow of liquid sodium from the lower pressure cold pool into the hot pool. The jet pump has a small high pressure driving stream diverted from the high pressure side of the reactor pumps. During normal operation, the jet pumps supplement the normal reactor pressure differential from the lower pressure cold pool to the hot pool. Upon the occurrence of a casualty involving loss of coolant pump pressure, and immediate cooling circuit is established by the back flow of sodium through the jet pumps from the reactor vessel hot pool to the reactor vessel cold pool. The cooling circuit includes flow into the reactor vessel liner flow gap immediate the reactor vessel wall and containment vessel where optimum and immediate discharge of residual reactor heat occurs.

Laboratory-scale integrated ARP filter test

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

Poirier, M.; Burket, P.

2016-03-01

The Savannah River Site (SRS) is currently treating radioactive liquid waste with the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). Recently, the low filter flux through the ARP of approximately 5 gallons per minute has limited the rate at which radioactive liquid waste can be treated. Salt Batch 6 had a lower processing rate and required frequent filter cleaning. There is a desire to understand the causes of the low filter flux and to increase ARP/MCU throughput. This task attempted to simulate the entire ARP process, including multiple batches (5), washing, chemical cleaning, andmore » blending the feed with heels and recycle streams. The objective of the tests was to determine whether one of these processes is causing excessive fouling of the crossflow or secondary filter. The authors conducted the tests with feed solutions containing 6.6 M sodium Salt Batch 6 simulant supernate with no MST.« less

Removal of heavy metal ions from aqueous solutions using lignocellulosic fibers

Treesearch

Beom-Goo Lee; Roger M. Rowell

2004-01-01

Spruce, coconut coir, sugarcane bagasse, kenaf bast, kenaf core, and cotton were tested for their ability to remove copper, nickel and zinc ions from aqueous-solutions as a function of their lignin content. The fibers were analyzed for sugar and lignin content and extracted with diethyl ether, ethyl alcohol. hot water, or 1% sodium hydroxide. The order of lignin...

Effective removal of hydrogen sulfide using 4A molecular sieve zeolite synthesized from attapulgite.

PubMed

Liu, Xinpeng; Wang, Rui

2017-03-15

In this work, 4A molecular sieve zeolite was synthesized from attapulgite (ATP) in different conditions and was applied initially for H 2 S removal. The sorbent was characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectra and N 2 adsorption/desorption. The effects of the synthesis condition and adsorption temperature were studied by dynamic adsorption experiment. The optimal adsorption temperature is 50°C. The H 2 S adsorption results have showed that the optimal synthesis conditions are as follows: the ratio of silicon to aluminum and ratio of sodium to silicon are both 1.5, the ratio of water to sodium is 30, crystallization temperature and crystallization time is 90°C, 4h, respectively. The breakthrough and saturation sulfur sorption capacities of zeolite synthesized under optimum conditions are up to nearly 10 and 15mg/g-sorbent, respectively, and the H 2 S removal rate is nearly 100%. The adsorption kinetics nonlinear fitting results show that the adsorption system follows Bingham model. These results indicate that 4A molecular sieve zeolite synthesized from attapulgite can be used for H 2 S removal promisingly. Copyright © 2016 Elsevier B.V. All rights reserved.

Cyanide oxidation by singlet oxygen generated via reaction between H2O2 from cathodic reduction and OCl(-) from anodic oxidation.

PubMed

Tian, Shichao; Li, Yibing; Zeng, Huabin; Guan, Wei; Wang, Yan; Zhao, Xu

2016-11-15

Cyanide is widely present in electroplating wastewater or metallurgical effluents. In the present study, the electrochemical destruction of cyanide with various anode and cathode compositions under alkaline conditions was investigated. The results indicated that the electrochemical system using RuO2/Ti as anode and activated carbon fiber (ACF) as cathode in the presence of sodium chloride was efficient for the cyanide removal. In this system, in situ generation of HClO by anodic oxidation of Cl(-) at RuO2/Ti anode occurred with the H2O2 generation by O2 reduction at ACF cathode. As confirmed by the electron spin resonance technique, the reaction between HClO and H2O2 led to the generation of singlet oxygen, which was responsible for the cyanide removal. Further experiment indicated that the cyanide removal efficiency increased with the increase of the current density or the sodium chloride concentration. Cyanate was identified as main product in the system. Besides, the system exhibited good stability for the cyanide removal, which was beneficial to its practical application. Copyright © 2016. Published by Elsevier Inc.

Potassium hydroxide poisoning

MedlinePlus

... effectively treat (adsorb) sodium hydroxide. For skin exposure, treatment may include: Surgical removal of burned skin (debridement) Transfer to a hospital that specializes in burn care Washing of the skin (irrigation), possibly every ...

Sodium Phosphate

MedlinePlus

... doctor if you have ever had a biopsy (removal of a piece of tissue for examination in ... room temperature and away from excess heat and moisture (not in the bathroom).Unneeded medications should be ...

Single molecule imaging of conformational dynamics in sodium-coupled transporters

NASA Astrophysics Data System (ADS)

Terry, Daniel S.

Neurotransmitter:sodium symporter (NSS) proteins remove neurotransmitters released into the synapse through a transport process driven by the physiological sodium ion (Na+) gradient. NSSs for dopamine, noradrenaline, and serotonin are targeted by the psychostimulants cocaine and amphetamines, as well as by antidepressants. The crystal structure of LeuT, a prokaryotic NSS homologue, revealed the NSS molecular architecture and has been the basis for extensive structural, biochemical, and computational investigations of the mechanism of transporter proteins with a LeuT-like fold. In this dissertation, the conformational states sampled by LeuT are explored using single-molecule fluorescence resonance energy transfer imaging methods, with special focus on the motions of transmembrane helix 1a that lead to inward release of substrate. We also explored how dynamics are modulated by substrate, Na+, and protons to produce efficient transport. These advances represent a first of a kind study of the dynamics of an integral membrane protein at a truly single-molecule scale. Advances in instrumentation, analysis tools, and organic fluorophores were all required to achieve these goals, and such advances are also described. While these experiments were performed with detergent-solubilized protein, preliminary work suggests that imaging of LeuT in proteoliposomes is feasible and a fluorescence sensor assay could be used to simultaneously detect conformational dynamics and transport function.

[Effect of Membrane Wettability on Membrane Fouling and Chemical Durability of SPG Membranes].

PubMed

Zhang, Jing; Xiao, Tai-min; Zhang, Jing; Cao, Li-ya; Du, Ya-wei; Liu, Chun; Zhang, Lei

2015-05-01

Shirasu porous glass (SPG) membranes have been applied for microbubble aeration in aerobic wastewater treatment. In the present study, both hydrophilic and hydrophobic SPG membranes were used in a microbubble-aerated biofilm reactor with online chemical cleaning, and their membrane fouling and chemical durability were determined to be strongly dependent on the membrane wettability. The fouling layer formed on the surface of both membranes was confirmed to be mainly organic fouling, and the hydrophobic membrane showed a relatively stronger resistance to the organic fouling. The severe chemical corrosion of the hydrophilic membrane was observed due to exposure to the alkaline sodium hypochlorite solution used for chemical cleaning, which resulted in significant increases in the median pore diameter and the porosity. On the other hand, the pore structure of the hydrophobic membrane changed slightly when exposed to the alkaline sodium hypochlorite solution, suggesting its strong alkali-resistance due to the non-wetting surface. However, the surface hydrophobic groups of hydrophobic membrane could be oxidized by sodium hypochlorite solution, resulting in more wettable membrane surface. The hydrophobic membrane also showed better performance in the respects of oxygen transfer, contaminant removal and energy-saving. Therefore, the hydrophobic membrane seemed more appropriate to be applied for microbubble aeration in aerobic wastewater treatment process.

Is it safe to re-access sodium bicarbonate bottles for use in minor surgery?

PubMed

Bjornson, Lindsay; Bucevska, Marija; Tilley, Peter; Verchere, Cynthia

2018-04-06

Sodium bicarbonate is added to lidocaine to reduce injection pain. In Canada, it is available in vials exceeding the injection volume 100-fold. These are single-use vials that should be disposed of after one access. Some surgeons re-use vials to reduce waste, potentially causing contamination. This study aims to review the safety of sodium bicarbonate and assess alternatives to current practice. Strains of Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Burkholderia cepacia were used to assess bacterial growth in vials of sodium bicarbonate. Each pathogen was inoculated into a vial for 14 days at room temperature. At several time points, 1 mL of solution was removed and diluted. One hundred microliters were transferred to blood agar plates and incubated at 35 °C. Colony counts were calculated, averaged and plotted onto a logarithmic graph. Colony counts of all strains fell below observational threshold after 7 days in sodium bicarbonate. Although all strains were reduced, bacteria can survive in sodium bicarbonate for several days, during which transmission may occur. Sodium bicarbonate vials should be treated as single-dose, as indicated by the manufacturers. To reduce waste, hospital pharmacies can repackage sodium bicarbonate into smaller vials or pre-alkalize lidocaine with sodium bicarbonate. Copyright © 2018 Elsevier Inc. All rights reserved.

Ethanol-assisted gel chromatography for single-chirality separation of carbon nanotubes

NASA Astrophysics Data System (ADS)

Zeng, Xiang; Hu, Jinwen; Zhang, Xiao; Zhou, Naigen; Zhou, Weiya; Liu, Huaping; Xie, Sishen

2015-10-01

Surfactants or polymers are usually used for the liquid processing of carbon nanotubes for their structure separation. However, they are difficult to remove after separation, affecting the intrinsic properties and applications of the separated species. Here, we report an ethanol-assisted gel chromatography for the chirality separation of single-walled carbon nanotubes (SWCNTs), in which ethanol is employed to finely tune the density/coverage of sodium dodecyl sulfate (SDS) on nanotubes, and thus the interactions between SWCNTs and an allyl dextran-based gel. Incrementally increasing the ethanol content in a low-concentration SDS eluent leads to successive desorption of the different structure SWCNTs adsorbed on the gel, and to achieve multiple distinct (n, m) single-chirality species. The use of ethanol enables the working concentration of SDS to be reduced dramatically and also avoids the introduction of other surfactants or chemical reagents. More importantly, ethanol can be easily removed after separation. The ability of ethanol to tune the interactions between SWCNTs and the gel also gives a deeper insight into the separation mechanism of SWCNTs using gel chromatography.Surfactants or polymers are usually used for the liquid processing of carbon nanotubes for their structure separation. However, they are difficult to remove after separation, affecting the intrinsic properties and applications of the separated species. Here, we report an ethanol-assisted gel chromatography for the chirality separation of single-walled carbon nanotubes (SWCNTs), in which ethanol is employed to finely tune the density/coverage of sodium dodecyl sulfate (SDS) on nanotubes, and thus the interactions between SWCNTs and an allyl dextran-based gel. Incrementally increasing the ethanol content in a low-concentration SDS eluent leads to successive desorption of the different structure SWCNTs adsorbed on the gel, and to achieve multiple distinct (n, m) single-chirality species. The use of ethanol enables the working concentration of SDS to be reduced dramatically and also avoids the introduction of other surfactants or chemical reagents. More importantly, ethanol can be easily removed after separation. The ability of ethanol to tune the interactions between SWCNTs and the gel also gives a deeper insight into the separation mechanism of SWCNTs using gel chromatography. Electronic supplementary information (ESI) available: Fig. S1-S13, additional discussion and experimental details. See DOI: 10.1039/c5nr04116c

Fast removal of malachite green dye using novel superparamagnetic sodium alginate-coated Fe3O4 nanoparticles.

PubMed

Mohammadi, Abbas; Daemi, Hamed; Barikani, Mehdi

2014-08-01

In this study, superparamagnetic sodium alginate-coated Fe3O4 nanoparticles (Alg-Fe3O4) as a novel magnetic adsorbent were prepared by in situ coprecipitation method, in which Fe3O4 nanoparticles were precipitated from FeCl3 and FeCl2 under alkaline medium in the presence of sodium alginate. The Alg-Fe3O4 nanoparticles were used for removal of malachite green (MG) from aqueous solutions using batch adsorption technique. The characterization of synthesized nanoparticles was performed using XRD, FTIR, TEM, TGA and vibrating sample magnetometer (VSM) techniques. FTIR analysis of synthesized nanoparticles provided the evidence that sodium alginate was successfully coated on the surface of Fe3O4 nanoparticles. The FT-IR and TGA characterization showed that the Alg-Fe3O4 nanoparticles contained about 14% (w/w) of sodium alginate. Moreover, TEM analysis indicated that the average diameter of the Alg-Fe3O4 nanoparticles was about 12nm. The effects of adsorbent dosage, pH and temperature were investigated on the adsorption properties of MG onto Alg-Fe3O4 nanoparticles. The equilibrium adsorption data were modeled using the Langmuir and Freundlich isotherms. The maximum adsorption capacity obtained from Langmuir isotherm equation was 47.84mg/g. The kinetics of adsorption of MG onto Alg-Fe3O4 nanoparticles were investigated using the pseudo-first-order and pseudo-second-order kinetic models. The results showed that the adsorption of MG onto nanoparticles followed pseudo-second-order kinetic model. Copyright © 2014 Elsevier B.V. All rights reserved.

Nitrogen transformation under different dissolved oxygen levels by the anoxygenic phototrophic bacterium Marichromatium gracile.

PubMed

Hong, Xuan; Chen, Zhongwei; Zhao, Chungui; Yang, Suping

2017-06-01

Marichromatium gracile: YL28 (M. gracile YL28) is an anoxygenic phototrophic bacterial strain that utilizes ammonia, nitrate, or nitrite as its sole nitrogen source during growth. In this study, we investigated the removal and transformation of ammonium, nitrate, and nitrite by M. gracile YL28 grown in a combinatorial culture system of sodium acetate-ammonium, sodium acetate-nitrate and sodium acetate-nitrite in response to different initial dissolved oxygen (DO) levels. In the sodium acetate-ammonium system under aerobic conditions (initial DO = 7.20-7.25 mg/L), we detected a continuous accumulation of nitrate and nitrite. However, under semi-anaerobic conditions (initial DO = 4.08-4.26 mg/L), we observed a temporary accumulation of nitrate and nitrite. Interestingly, under anaerobic conditions (initial DO = 0.36-0.67 mg/L), there was little accumulation of nitrate and nitrite, but an increase in nitrous oxide production. In the sodium acetate-nitrite system, nitrite levels declined slightly under aerobic conditions, and nitrite was completely removed under semi-anaerobic and anaerobic conditions. In addition, M. gracile YL28 was able to grow using nitrite as the sole nitrogen source in situations when nitrogen gas produced by denitrification was eliminated. Taken together, the data indicate that M. gracile YL28 performs simultaneous heterotrophic nitrification and denitrification at low-DO levels and uses nitrite as the sole nitrogen source for growth. Our study is the first to demonstrate that anoxygenic phototrophic bacteria perform heterotrophic ammonia-oxidization and denitrification under anaerobic conditions.

Evaluation of the effect of formic acid and sodium formate on hair reduction in rat

PubMed Central

Banihashemi, Mahnaz; Rad, Abolfazl Khajavi; Yazdi, Seyed Abbas Tabatabaee; Rakhshande, Hasan; Ghoyonlo, Vahid Mashayekhi; Zabihi, Zahra; Yousefzadeh, Hadis

2011-01-01

Hirsutism is a common problem in dermatology that imposes high socioeconomical costs on medical care. Consequently, researchers are actively searching for cheaper and safer methods for therapeutic treatment. The objective of the present study is to evaluate formic oil, enriched from formic acid, for the removal of unwanted hair. In this study, 32 female rats (150–200 g) were randomly divided into four groups and maintained with normal water and food availability. A patch of skin was shaved on each rat for application of test solutions. The control group was treated with local once-daily applications of normal saline. The formic acid, acetic acid, and sodium formate groups were treated with once-daily applications of formic acid (pH 5.5), acetic acid (pH 5.5), or sodium formate, respectively. After 2 weeks, horizontally cut sample biopsies were removed, and the numbers of hair follicles were counted under high field microscopy by a specialist blinded to the treatments. Kolmogorov–Smirnov test results indicated a nonparametric distribution for the rat groups. ANOVA analysis indicated no statistically significant differences between groups (P < 0.05). There weren’t any side effects or evidence for toxicity during the study period. However, hair follicle counts showed a descending order of control, acetic acid, formic acid, and sodium formate. Although the sodium formate group had the lowest hair follicle numbers, the difference was not statistically significant (P > 0.05). Formic acid was not effective in reducing hair follicle numbers in rats. PMID:21760741

Comparative Evaluation of Two Final Irrigation Techniques for the Removal of Precipitate Formed by the Interaction between Sodium Hypochlorite and Chlorhexidine.

PubMed

Metri, Malasiddappa; Hegde, Swaroop; Dinesh, K; Indiresha, H N; Nagaraj, Shruthi; Bhandi, Shilpa H

2015-11-01

To evaluate the effectiveness of two final irrigation techniques for the removal of precipitate formed by the interaction between sodium hypochlorite (NaOCl) and chlorhexidine (CHX). Sixty freshly extracted human maxillary incisor teeth were taken and randomly divided into three groups, containing 20 teeth each. Group 1 (control group), were irrigated with 5 ml of 2.5% NaOCl and a final flush with 5 ml of 2% chlorhexidine. Group 2 were irrigated with 5 ml of 2.5% NaOCl and 5 ml of 2% chlorhexidine followed by 5 ml of saline and agitated with F-files. Group 3 were irrigated with 5 ml of 2.5% NaOCl and 5 ml of 2% chlorhexidine followed by 5 ml of 15% citric acid and passively agitated with ultrasonics. A thin longitudinal groove was made along the buccal and lingual aspect of the root using diamond disks and split with chisel and mallet. Both halves of the split tooth will be examined under stereomicroscope. Results were tabulated and analyzed statistically using analysis of variance (ANOVA) and Mann-Whitney U test. There was a significant difference between the mean values (p < 0.05) in groups 2 and 3 compared to group 1 at each level. Passive ultrasonic irrigation is more effective than the F-file agitation technique to remove the precipitate at all three levels measured. Combination of sodium hypochlorite and chlorhexidine irrigation protocol has been practiced since from many years to achieve good results. However, it has adverse effect in the form of precipitate and which is considered to be a carcinogenic in nature, hence this precipitate should be removed.

Assessing the average sodium content of prepacked foods with nutrition declarations: the importance of sales data.

PubMed

Korošec, Živa; Pravst, Igor

2014-09-04

Processed foods are recognized as a major contributor to high dietary sodium intake, associated with increased risk of cardiovascular disease. Different public health actions are being introduced to reduce sodium content in processed foods and sodium intake in general. A gradual reduction of sodium content in processed foods was proposed in Slovenia, but monitoring sodium content in the food supply is essential to evaluate the progress. Our primary objective was to test a new approach for assessing the sales-weighted average sodium content of prepacked foods on the market. We show that a combination of 12-month food sales data provided by food retailers covering the majority of the national market and a comprehensive food composition database compiled using food labelling data represent a robust and cost-effective approach to assessing the sales-weighted average sodium content of prepacked foods. Food categories with the highest sodium content were processed meats (particularly dry cured meat), ready meals (especially frozen pizza) and cheese. The reported results show that in most investigated food categories, market leaders in the Slovenian market have lower sodium contents than the category average. The proposed method represents an excellent tool for monitoring sodium content in the food supply.

Assessing the Average Sodium Content of Prepacked Foods with Nutrition Declarations: The Importance of Sales Data

PubMed Central

Korošec, Živa; Pravst, Igor

2014-01-01

Processed foods are recognized as a major contributor to high dietary sodium intake, associated with increased risk of cardiovascular disease. Different public health actions are being introduced to reduce sodium content in processed foods and sodium intake in general. A gradual reduction of sodium content in processed foods was proposed in Slovenia, but monitoring sodium content in the food supply is essential to evaluate the progress. Our primary objective was to test a new approach for assessing the sales-weighted average sodium content of prepacked foods on the market. We show that a combination of 12-month food sales data provided by food retailers covering the majority of the national market and a comprehensive food composition database compiled using food labelling data represent a robust and cost-effective approach to assessing the sales-weighted average sodium content of prepacked foods. Food categories with the highest sodium content were processed meats (particularly dry cured meat), ready meals (especially frozen pizza) and cheese. The reported results show that in most investigated food categories, market leaders in the Slovenian market have lower sodium contents than the category average. The proposed method represents an excellent tool for monitoring sodium content in the food supply. PMID:25192028

Effectiveness of cross-flow microfiltration for removal of microorganisms associated with unpasteurized liquid egg white from process plant.

PubMed

Mukhopadhyay, S; Tomasula, P M; Van Hekken, D; Luchansky, J B; Call, J E; Porto-Fett, A

2009-08-01

Thermal preservation is used by the egg industry to ensure the microbiological safety of liquid egg white (LEW); however, it does not eliminate all microorganisms and impairs some of the delicate functional properties of LEW. In this study, a pilot-scale cross-flow microfiltration (MF) process was designed to remove the natural microflora present in commercial LEW, obtained from a local egg-breaking plant, while maintaining the nutritional and functional properties of the LEW. LEW, containing approximately 10(6 +/- 1.7) colony forming units (CFU) per milliliter of total aerobic bacteria, was microfiltered using a ceramic membrane with a nominal pore size of 1.4 microm, at a cross-flow velocity of 6 m/s. To facilitate MF, LEW was screened, homogenized, and then diluted (1 : 2, w/w) with distilled water containing 0.5% sodium chloride. Homogenized LEW was found to have a threefold lower viscosity than unhomogenized LEW. Influence of MF temperature (25 and 40 degrees C) and pH (6 and 9) on permeate flux, transmission of egg white nutrients across the membrane, and microbial removal efficiency were evaluated. The pH had a significantly greater influence on permeate flux than temperature. Permeate flux increased by almost 148% when pH of LEW was adjusted from pH 9 to pH 6 at 40 degrees C. Influence of temperature on permeate flux, at a constant pH, however, was found to be inconclusive. Microbial removal efficiency was at least 5 log(10) CFU/mL. Total protein and SDS-PAGE analysis indicated that this MF process did not alter the protein composition of the permeate, compared to that of the feed LEW, and that the foaming properties of LEW were retained in the postfiltered samples.

Sodium, phosphate, glucose, bicarbonate, and alanine interactions in the isolated proximal convoluted tubule of the rabbit kidney.

PubMed Central

Dennis, V W; Brazy, P C

1978-01-01

Interactions among the transport systems involved with sodium, bicarbonate, glucose, phosphate, and alanine absorption in isolated segments of the rabbit proximal convoluted tubule were examined with radioisotopic techniques to measure glucose, phosphate, and fluid absorption rates. The composition of the perfusate and bath varied from normal, physiological fluids to fluids deficient in a single solute. The deletion of glucose from the perfusate increased the lumen-to-bath flux of phosphate from 5.51 +/- 1.15 to 8.32 +/- 1.34 pmol/mm-min (P less than 0.01). Similar changes occurred when glucose transport was inhibited by phlorizin 10 micron in the perfusate, The deletion of alanine from the perfusate increased the lumen-to-bath flux of phosphate from 6.55 +/- 1.08 to 9.00 +/- 1.30 pmol/mm-min (P less than 0.01) but did not affect glucose transport significantly, 80.1 +/- 10.1 vs. 72.5 +/- 5.4 pmol/mm-min. Replacement of intraluminal sodium with choline, elimination of potassium from the bath, and removal of bicarbonate from the lumen and bath each reduced glucose, phosphate, and fluid absorption. These data indicate that the proximal absorptive processes for glucose and for phosphate include elements that are dependent upon some function of sodium transport. Additionally, the effects on phosphate transport of deleting glucose or alanine occur independent of any changes in net sodium transport and are opposite the effects of deleting bicarbonate. These differences may relate to the observations that the transport of glucose and alanine is electrogenic while that of bicarbonate is not. Regardless of possible mechanisms, the data demonstrate that important changes in the absorption rates of different solutes handled significantly by the proximal convoluted tubule may occur in response to changes in specific components of proximal sodium transport. PMID:670399

Ammonium nitrogen removal from coking wastewater by chemical precipitation recycle technology.

PubMed

Zhang, Tao; Ding, Lili; Ren, Hongqiang; Xiong, Xiang

2009-12-01

Ammonium nitrogen removal from wastewater has been of considerable concern for several decades. In the present research, we examined chemical precipitation recycle technology (CPRT) for ammonium nitrogen removal from coking wastewater. The pyrolysate resulting from magnesium ammonium phosphate (MAP) pyrogenation in sodium hydroxide (NaOH) solution was recycled for ammonium nitrogen removal from coking wastewater. The objective of this study was to investigate the conditions for MAP pyrogenation and to characterize of MAP pyrolysate for its feasibility in recycling. Furthermore, MAP pyrolysate was characterized by scanning electron microscope (FESEM), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR) as well as X-ray diffraction (XRD). The MAP pyrolysate could be produced at the optimal condition of a hydroxyl (OH(-)) to ammonium molar ratio of 2:1, a heating temperature of 110 degrees C, and a heating time of 3h. Surface characterization analysis indicated that the main component of the pyrolysate was amorphous magnesium sodium phosphate (MgNaPO(4)). The pyrolysate could be recycled as a magnesium and phosphate source at an optimum pH of 9.5. When the recycle times were increased, the ammonium nitrogen removal ratio gradually decreased if the pyrolysate was used without supplementation. When the recycle times were increased, the ammonium nitrogen removal efficiency was not decreased if the added pyrolysate was supplemented with MgCl(2).6H(2)O plus Na(2)HPO(4).12H(2)O during treatment. A high ammonium nitrogen removal ratio was obtained by using pre-formed MAP as seeding material.

Sodium content of processed foods in the United Kingdom: analysis of 44,000 foods purchased by 21,000 households123

PubMed Central

Capelin, Cathy; Dunford, Elizabeth K; Webster, Jacqueline L; Neal, Bruce C; Jebb, Susan A

2011-01-01

Background: In the United Kingdom, sodium reduction targets have been set for a large number of processed food categories. Assessment and monitoring are essential to evaluate progress. Objectives: Our aim was to determine whether household consumer panel food-purchasing data could be used to assess the sodium content of processed foods. Our further objectives were to estimate the mean sodium content of UK foods by category and undertake analyses weighted by food-purchasing volumes. Design: Data were obtained for 21,108 British households between October 2008 and September 2009. Purchasing data (product description, product weight, annual purchases) and sodium values (mg/100 g) were collated for all food categories known to be major contributors to sodium intake. Unweighted and weighted mean sodium values were calculated. Results: Data were available for 44,372 food products. The largest contributors to sodium purchases were table salt (23%), processed meat (18%), bread and bakery products (13%), dairy products (12%), and sauces and spreads (11%). More than one-third of sodium purchased (37%) was accounted for by 5 food categories: bacon, bread, milk, cheese, and sauces. For some food groups (bread and bakery, cereals and cereal products, processed meat), purchase-weighted means were 18–35% higher than unweighted means, suggesting that market leaders have higher sodium contents than the category mean. Conclusion: The targeting of sodium reduction in a small number of food categories and focusing on products sold in the highest volumes could lead to large decreases in sodium available for consumption and therefore to gains in public health. PMID:21191142

Sodium content of processed foods in the United Kingdom: analysis of 44,000 foods purchased by 21,000 households.

PubMed

Ni Mhurchu, Cliona; Capelin, Cathy; Dunford, Elizabeth K; Webster, Jacqueline L; Neal, Bruce C; Jebb, Susan A

2011-03-01

In the United Kingdom, sodium reduction targets have been set for a large number of processed food categories. Assessment and monitoring are essential to evaluate progress. Our aim was to determine whether household consumer panel food-purchasing data could be used to assess the sodium content of processed foods. Our further objectives were to estimate the mean sodium content of UK foods by category and undertake analyses weighted by food-purchasing volumes. Data were obtained for 21,108 British households between October 2008 and September 2009. Purchasing data (product description, product weight, annual purchases) and sodium values (mg/100 g) were collated for all food categories known to be major contributors to sodium intake. Unweighted and weighted mean sodium values were calculated. Data were available for 44,372 food products. The largest contributors to sodium purchases were table salt (23%), processed meat (18%), bread and bakery products (13%), dairy products (12%), and sauces and spreads (11%). More than one-third of sodium purchased (37%) was accounted for by 5 food categories: bacon, bread, milk, cheese, and sauces. For some food groups (bread and bakery, cereals and cereal products, processed meat), purchase-weighted means were 18-35% higher than unweighted means, suggesting that market leaders have higher sodium contents than the category mean. The targeting of sodium reduction in a small number of food categories and focusing on products sold in the highest volumes could lead to large decreases in sodium available for consumption and therefore to gains in public health.

Evidence for coupled transport of bicarbonate and sodium in cultured bovine corneal endothelial cells.

PubMed

Jentsch, T J; Keller, S K; Koch, M; Wiederholt, M

1984-01-01

Using intracellular microelectrode technique, the response of the voltage V across the plasma membrane of cultured bovine corneal endothelial cells to changes in sodium and bicarbonate concentrations was investigated. (1) The electrical response to changes in [HCO3-]o (depolarization upon lowering and hyperpolarization upon raising [HCO3-]o) was dependent on sodium. Lithium could fairly well be substituted for sodium, whereas potassium or choline were much less effective. (2) Removal of external sodium caused a depolarization, while a readdition led to a hyperpolarization, which increased with time of preincubation in the sodium-depleted medium. (3) The response to changes in [Na+]o was dependent on bicarbonate. In a nominally bicarbonate-free medium, its amplitude was decreased or even reversed in sign. (4) Application of SITS or DIDS (10(-3) M) had a similar effect on the response to sodium as bicarbonate-depleted medium. (5) At [Na+]o = 151 mM and [HCO3-]o = 46 mM, the transients of V depended, with 39.0 +/- 9.0 (SD) mV/decade, on bicarbonate and, with 15.3 +/- 5.8 (SD) mV/decade, on sodium. (6) After the preincubation of cells with lithium, replacement of Li by choline led to similar effects as the replacement of sodium by choline, though the response of V was smaller with Li. This response could be reduced or reversed by the removal of bicarbonate or by the application of SITS. (7) Amiloride (10(-3) M) caused a reversible hyperpolarization of the steady-state potential by 8.5 +/- 2.6 mV (SD). It did not affect the immediate response to changes in [Na+]o or [HCO3-]o, but reduced the speed of regaining the steady-state potential after a change in [HCO3-]o. (8) Ouabain (10(-4) M) caused a fast depolarization of -6.8 +/- 1.1 (SD) mV, which was followed by a continuing slower depolarization. The effect was almost identical at 10(-5) M. (9) It is suggested, that corneal endothelial cells possess a cotransport for sodium and bicarbonate, which transports net negative charge with these ions. It is inhibitable by stilbenes, but not directly affected by amiloride or ouabain. Lithium is a good substitute for sodium with respect to bicarbonate transport and is transported itself. In addition, the effect of amiloride provides indirect evidence for the existence of a Na+/H+-antiport. A model for the transepithelial transport of bicarbonate across the corneal endothelium is proposed.

Improved Synthesis Of Potassium Beta' '-Alumina

NASA Technical Reports Server (NTRS)

Williams, Roger M.; Jeffries-Nakamura, Barbara; Ryan, Margaret A.; O'Connor, Dennis E.; Kisor, Adam; Underwood, Mark

1996-01-01

Improved formulations of precursor materials synthesize nearly-phase-pure potassium beta' '-alumina solid electrolyte (K-BASE) powder. Materials are microhomogeneous powders (or, alternatively, gels) containing K(+,) Mg(2+), and Al(3+). K-BASE powder produced used in potassium-working-fluid alkali-metal thermal-to-electric conversion (K-AMTEC), in which heat-input and heat-rejection temperatures lower than sodium-working-fluid AMTEC (Na-AMTEC). Additional potential use lies in purification of pottassium by removal of sodium and calcium.

Technical Information on the Carbonation of the EBR-II Reactor, Summary Report Part 2: Application to EBR-II Primary Sodium System and Related Systems

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

Steven R. Sherman; Collin J. Knight

Residual sodium is defined as sodium metal that remains behind in pipes, vessels, and tanks after the bulk sodium metal has been melted and drained from such components. The residual sodium has the same chemical properties as bulk sodium, and differs from bulk sodium only in the thickness of the sodium deposit. Typically, sodium is considered residual when the thickness of the deposit is less than 5-6 cm. This residual sodium must be removed or deactivated when a pipe, vessel, system, or entire reactor is permanently taken out of service, in order to make the component or system safer and/ormore » to comply with decontamination and decomissioning regulations. As an alternative to the established residual sodium deactivation techniques (steam-and-nitrogen, wet vapor nitrogen, etc.), a technique involving the use of moisture and carbon dioxide has been developed. With this technique, sodium metal is converted into sodium bicarbonate by reacting it with humid carbon dioxide. Hydrogen is emitted as a by-product. This technique was first developed in the laboratory by exposing sodium samples to humidifed carbon dioxide under controlled conditions, and then demonstrated on a larger scale by treating residual sodium within the Experimental Breeder Reactor II (EBR-II) secondary cooling system, followed by the primary cooling system, respectively. The EBR-II facility is located at the Idaho National Laboratory (INL) in southeastern Idaho, USA. This report is Part 2 of a two-part report. This second report provides a supplement to the first report and describes the application of the humdidified carbon dioxide technique ("carbonation") to the EBR-II primary tank, primary cover gas systems, and the intermediate heat exchanger. Future treatment plans are also provided.« less

Pilot scale treatment of chromite ore processing residue using sodium sulfide in single reduction and coupled reduction/stabilization processes.

PubMed

Velasco, Antonio; Ramírez, Martha; Hernández, Sergio; Schmidt, Winfried; Revah, Sergio

2012-03-15

Single Cr(VI) reduction and coupled reduction/stabilization (R/S) processes were evaluated at pilot scale to determine their effectiveness to treat chromite ore processing residue (COPR). Sodium sulfide was used as the reducing agent and cement, gypsum and lime were tested as the stabilizing agents. The pilot experiments were performed in a helical ribbon blender mixer with batches of 250 kg of COPR and mixing time up to 30 min. Na2S/Cr(VI) mass ratios of 4.6, 5.7 and 6.8 were evaluated in the single reduction process to treat COPR with Cr(VI) concentration of ≈4.2 g/kg. The R/S process was tested with a Na2S/Cr(VI) mass ratio of 5.7 and including stabilizing agents not exceeding 5% (w/w(COPR)), to treat COPR with a Cr(VI) content of ≈5.1g/kg. The single reduction process with a ratio of 6.8, reached Cr(VI) reduction efficiencies up to 97.6% in the first days, however these values decreased to around 93% after 380 days of storage. At this point the total Cr level was around 12.5 mg/L. Cr(VI) removal efficiencies exceeding 96.5% were reached and maintained during 380 days when the coupled R/S process was evaluated. Total Cr levels lower than 5 mg/l were attained at the initials days in all R/S batch tested, however after 380 days, concentrations below the regulatory limit were only found with gypsum (2%) as single agent and with a blend of cement (4%) and lime (1%). These results indicated that the coupled R/S process is an excellent alternative to stabilize COPR. Copyright © 2011 Elsevier B.V. All rights reserved.

Biofilm formation and granule properties in anaerobic digestion at high salinity.

PubMed

Gagliano, M C; Ismail, S B; Stams, A J M; Plugge, C M; Temmink, H; Van Lier, J B

2017-09-15

For the anaerobic biological treatment of saline wastewater, Anaerobic Digestion (AD) is currently a possibility, even though elevated salt concentrations can be a major obstacle. Anaerobic consortia and especially methanogenic archaea are very sensitive to fluctuations in salinity. When working with Upflow Sludge Blanket Reactor (UASB) technology, in which the microorganisms are aggregated and retained in the system as a granular biofilm, high sodium concentration negatively affects aggregation and consequently process performances. In this research, we analysed the structure of the biofilm and granules formed during the anaerobic treatment of high salinity (at 10 and 20 g/L of sodium) synthetic wastewater at lab scale. The acclimated inoculum was able to accomplish high rates of organics removal at all the salinity levels tested. 16S rRNA gene clonal analysis and Fluorescence In Situ Hybridization (FISH) analyses identified the acetoclastic Methanosaeta harundinacea as the key player involved acetate degradation and microbial attachment/granulation. When additional calcium (1 g/L) was added to overcome the negative effect of sodium on microbial aggregation, during the biofilm formation process microbial attachment and acetate degradation decreased. The same result was observed on granules formation: while calcium had a positive effect on granules strength when added to UASB reactors, Methanosaeta filaments were not present and the degradation of the partially acidified substrate was negatively influenced. This research demonstrated the possibility to get granulation at high salinity, bringing to the forefront the importance of a selection towards Methanosaeta cells growing in filamentous form to obtain strong and healthy granules. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Color and Surface Chemistry Changes of Pine Wood Flour after Extraction and Delignification

Treesearch

Yao Chen; Mandla A. Tshabalala; Jianmin Gao; Nicole M. Stark; Yongming Fan

2014-01-01

A detailed study was undertaken to examine the color and chemistry changes of pine wood flour when its extractives are removed and when it is delignified. The solvent systems employed were toluene/ethanol (TE), acetone/water (AW), and hot-water (HW), while sodium chlorite/acetic acid were used for delignification (i.e., lignin removal (LR)). Samples were analyzed by...

Nonaqueous purification of mixed nitrate heat transfer media

DOEpatents

Fiorucci, Louis C.; Morgan, Michael J.

1983-12-20

A nonaqueous, in-line method for removing carbonate and hydroxide contamination from a molten mixed sodium nitrate/potassium nitrate heat transfer salt. The method comprises dissolving a stoichiometric quantity of anhydrous Ca(NO.sub.3).sub.2 in the melt whereby an insoluble CaCO.sub.3 and Ca(OH).sub.2 precipitate is formed. The precipitate can be removed by settling, filtration or floatation techniques.

ANALYSIS OF SAMPLES FROM TANK 5F CHEMICAL CLEANING

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

Poirier, M.; Fink, S.

2011-03-07

The Savannah River Site (SRS) is preparing Tank 5F for closure. The first step in preparing the tank for closure is mechanical sludge removal. Following mechanical sludge removal, SRS performed chemical cleaning with oxalic acid to remove the sludge heel. Personnel are currently assessing the effectiveness of the chemical cleaning. SRS personnel collected liquid samples during chemical cleaning and submitted them to Savannah River National Laboratory (SRNL) for analysis. Following chemical cleaning, they collected a solid sample (also known as 'process sample') and submitted it to SRNL for analysis. The authors analyzed these samples to assess the effectiveness of themore » chemical cleaning process. The conclusions from this work are: (1) With the exception of iron, the dissolution of sludge components from Tank 5F agreed with results from the actual waste demonstration performed in 2007. The fraction of iron removed from Tank 5F by chemical cleaning was significantly less than the fraction removed in the SRNL demonstrations. The likely cause of this difference is the high pH following the first oxalic acid strike. (2) Most of the sludge mass remaining in the tank is iron and nickel. (3) The remaining sludge contains approximately 26 kg of barium, 37 kg of chromium, and 37 kg of mercury. (4) Most of the radioactivity remaining in the residual material is beta emitters and {sup 90}Sr. (5) The chemical cleaning removed more than {approx} 90% of the uranium isotopes and {sup 137}Cs. (6) The chemical cleaning removed {approx} 70% of the neptunium, {approx} 83% of the {sup 90}Sr, and {approx} 21% of the {sup 60}Co. (7) The chemical cleaning removed less than 10% of the plutonium, americium, and curium isotopes. (8) The chemical cleaning removed more than 90% of the aluminium, calcium, and sodium from the tank. (9) The cleaning operations removed 61% of lithium, 88% of non-radioactive strontium, and 65% of zirconium. The {sup 90}Sr and non-radioactive strontium were measured by different methods, and the differences in the fraction removed are not statistically significant. (10) Chemical cleaning removed 10-50% of the barium, chromium, iron, magnesium, manganese, and silicon. (11) Chemical cleaning removed only {approx}1% of the nickel.« less

Influence of seasonal climate differences on the pharmaceutical, hormone and personal care product removal efficiency of a drinking water treatment plant.

PubMed

Azzouz, Abdelmonaim; Ballesteros, Evaristo

2013-11-01

The potential presence of pharmaceuticals, hormones and personal care products in drinking water supplies has raised concerned over the efficiency with which these substances are removed by water treatment processes. In this work, we analyzed samples of raw, unprocessed water collected in different periods and found them to contain higher levels of these contaminants in the colder periods (viz. 12-314 ng L(-1) in autumn and winter as compared to 8-127 ng L(-1) in spring and summer) as a result of their biodegradation being favoured by high temperatures and solar irradiance. We also assessed the efficiency with which these contaminants are removed from drinking water by a water treatment plant operating in south-eastern Spain. Preoxidation with potassium permanganate and chloramination with sodium hypochlorite in the presence of highly concentrated ammonia were found to be the treatment steps most markedly contributing to the removal of pharmaceuticals, hormones and personal care products from drinking water (especially in the warmer periods, where these contaminants were completely removed from the water). By contrast, water treated in the colder periods (autumn and winter) still contained small amounts of ibuprofen and carbamazepine (0.09-0.5 ng L(-1)) which, however, accounted for less than 0.2% of their original concentrations in the water prior to treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sequential use of bentonites and solar photocatalysis to treat winery wastewater.

PubMed

Rodríguez, Eva; Márquez, Gracia; Carpintero, Juan Carlos; Beltrán, Fernando J; Alvarez, Pedro

2008-12-24

The sequential use of low-cost adsorbent bentonites and solar photocatalysis to treat winery wastewater has been studied. Three commercial sodium-bentonites (MB-M, MB-G, and MB-P) and one calcium-bentonite (Bengel) were characterized and used in this study. These clay materials were useful to totally remove turbidity (90-100%) and, to a lesser extent, color, polyphenols (PPh), and soluble chemical oxygen demand (CODS) from winery wastewater. Both surface area and cation exchange capacity (CEC) of bentonite had a positive impact on treatment efficiency. The effect of pH on turbidity removal by bentonites was studied in the 3.5-12 pH range. The bentonites were capable of greatly removing turbidity from winery wastewater at pH 3.5-5.5, but removal efficiency decreased with pH increase beyond this range. Settling characteristics (i.e., sludge volume index (SVI) and settling rate) of bentonites were also studied. Best settling properties were observed for bentonite doses around 0.5 g/L. The reuse of bentonite for winery wastewater treatment was found not to be advisable as the turbidity and PPh removal efficiencies decreased with successive uses. The resulting wastewater after bentonite treatment was exposed to solar radiation at oxic conditions in the presence of Fe(III) and Fe(III)/H2O2 catalysts. Significant reductions of COD, total organic carbon (TOC), and PPh were achieved by these solar photocatalytic processes.

Titanate-based adsorbents for radioactive ions entrapment from water.

PubMed

Yang, Dongjiang; Liu, Hongwei; Zheng, Zhanfeng; Sarina, Sarina; Zhu, Huaiyong

2013-03-21

This feature article reviews some titanate-based adsorbents for the removal of radioactive wastes (cations and anions) from water. At the beginning, we discuss the development of the conventional ion-exchangeable titanate powders for the entrapment of radioactive cations, such as crystalline silicotitanate (CST), monosodium titanate (MST), peroxotitanate (PT). Then, we specially emphasize the recent progress in the uptake of radioactive ions by one-dimensional (1D) sodium titanate nanofibers and nanotubes, which includes the synthesis and phase transformation of the 1D nanomaterials, adsorption ability (capacity, selectivity, kinetics, etc.) of radioactive cations and anions, and the structural evolution during the adsorption process.

URANIUM DECONTAMINATION

DOEpatents

Buckingham, J.S.; Carroll, J.L.

1959-12-22

A process is described for reducing the extractability of ruthenium, zirconium, and niobium values into hexone contained in an aqueous nitric acid uranium-containing solution. The solution is made acid-deficient, heated to between 55 and 70 deg C, and at that temperature a water-soluble inorganic thiosulfate is added. By this, a precipitate is formed which carries the bulk of the ruthenium, and the remainder of the ruthenium as well as the zirconium and niobium are converted to a hexone-nonextractable form. The rutheniumcontaining precipitate can either be removed from the solu tion or it can be dissolved as a hexone-non-extractable compound by the addition of sodium dichromate prior to hexone extraction.

Monitoring sodium in commercially processed foods from stores and restaurants

USDA-ARS?s Scientific Manuscript database

Most of the sodium we eat comes from commercially processed foods from stores and restaurants. Sodium reduction in these foods is a key component of several recent public health efforts. Agricultural Research Service (ARS) of USDA, CDC and FDA have launched a collaborative program to monitor sodium ...

An in vitro evaluation of passive ultrasonic agitation of different irrigants on smear layer removal after post space preparation: a scanning electron microscopic study.

PubMed

Srirekha, A; Rashmi, K; Hegde, Jayshree; Lekha, S; Rupali, K; Reshmi, George

2013-09-01

This study evaluated the removal of debris and smear layer after post space preparation using different irrigations and passive ultrasonic agitation. Sixty human premolars were decoronated and post space prepared after endodontic therapy. The samples were then randomly divided into three experimental groups (Groups A, B, C) and one control group (Group D) with fifteen samples in each group. Groups A and B samples were treated with 10 % citric acid and 17 % ethylenediamintetraacetic acid (EDTA), respectively and passive ultrasonic agitation was done, rinsed with sodium hypochlorite and finally flushed with saline. Group C samples were conditioned with 36 % phosphoric acid and then rinsed with saline. The control group was treated with 3 % sodium hypochlorite, passive ultrasonic agitation done and flushed with saline. The samples were sectioned and evaluated for debris and smear layer removal under scanning electron microscope. 10 % citric acid showed the best removal of smear layer when compared with 17 % EDTA and 36 % phosphoric acid, but was not statistically significant (p > 0.05). The difference in scoring for debris and smear layer removal in the coronal, middle and apical third of post space of experimental groups in comparison with control group was statistically significant (p < 0.001).

Fe(0)-Fe3O4 nanocomposites embedded polyvinyl alcohol/sodium alginate beads for chromium (VI) removal.

PubMed

Lv, Xiaoshu; Jiang, Guangming; Xue, Xiaoqin; Wu, Donglei; Sheng, Tiantian; Sun, Chen; Xu, Xinhua

2013-11-15

In this study, Fe(0)-Fe3O4 nanocomposites embedded polyvinyl alcohol (PVA)/sodium alginate (SA) beads were synthesized, which exhibited an excellent physical properties and catalytic reactivity, and a robust performance of post-separation (complete separation using a simple grille) and reusability (efficiency of 69.8% after four runs) in Cr(VI) removal. 5.0 wt% PVA with 1.5 wt% SA was the optimal proportion for beads molding, and the followed acidification and reduction treatments were critical to ensure high mechanical strength and high Cr(VI) removal ability of beads. Effects of Fe(0) and Fe3O4 mass fraction, initial pH and Cr(VI) concentration on final removal efficiency were also evaluated. Merely 0.075 wt% Fe(0) together with 0.30 wt% Fe3O4 was sufficient to deal with 20 mg L(-1) Cr(VI) solution. The efficiency decreased from 100 to 79.5% as initial Cr(VI) increased from 5 to 40 mg L(-1), while from 99.3 to 76.3% with increasing pH from 3.0 to 11.0. This work provides a practical and high-efficient method for heavy metal removal from water body, and simultaneously solves the problems in stabilization, separation and regeneration of Fe(0) nanoparticles. Copyright © 2013 Elsevier B.V. All rights reserved.

[Isolation, Identification and Nitrogen Removal Characteristics of a Heterotrophic Nitrification-Aerobic Denitrification Strain y3 Isolated from Marine Environment].

PubMed

Sun, Qing-hua; Yu, De-shuang; Zhang, Pei-yu; Lin, Xue-zheng; Xu, Guang-yao; Li, Jin

2016-03-15

A heterotrophic nitrification--aerobic denitrification bacterium named y3 was isolated from the sludge of Jiaozhou Bay using the enrichment medium with seawater as the matrix. It was identified as Pseudomonas sp. based on the morphological observation, physiological experiments and sequence analysis of 16S rRNA. The experiment results showed that the optimal carbon resource was sodium citrate, the optimal pH was 7.0, and the optimal C/N was 13. The strain could use NH₄Cl, NaNO₂ and KNO₃ as sole nitrogen source, and the removal efficiencies were 98.69%, 78.38% and 72.95% within 20 hours, respectively. There was no nitrate and nitrite accumulation during the heterotrophic nitrification process. Within 20 hours, the nitrogen removal efficiencies were 99.56%, 99.75% and 99.41%, respectively, in the mixed system with NO₃⁻-N: NO²⁻-N of 2:1, 1:1 and 1:2. When the NH₄⁺-N: NO₃⁻-N ratios were 2: 1 , 1: 1 , 1: 2, the nitrogen removal efficiencies were all 100% . When the NH₄⁺-N:NO₂⁻-N ratios were 2:1,1:1,1:2, the nitrogen removal efficiencies were 90.43%, 92.79% and 99.96%, respectively. They were higher than those with single nitrogen source. As a result, strain y3 had good nitrogen removal performance in high saline wastewater treatment.

Removal of herbicide paraquat from an aqueous solution by adsorption onto spent and treated diatomaceous earth.

PubMed

Tsai, W T; Hsien, K J; Chang, Y M; Lo, C C

2005-04-01

A spent diatomaceous earth from the beer brewery has been tentatively activated by sodium hydroxide at about 100 degrees C. The resulting product was used as a novel adsorbent for the adsorption of herbicide paraquat from an aqueous solution in a continuously stirred adsorber and batch flasks, respectively. The results showed that the adsorption process could be well described by the pseudo-second-order reaction model. From the view of the negatively charged surface of diatomaceous earth and cationic property of paraquat, the results were also reasonable to be explained by physical adsorption in the ion-exchange process under the effects of pH and temperature. Further, it was found that the Freundlich model appeared to fit the isotherm data better than the Langmuir model.

Impact of hydration state and molecular oxygen on the chemical stability of levothyroxine sodium.

PubMed

Hamad, Mazen Lee; Engen, William; Morris, Kenneth R

2015-05-01

Levothyroxine sodium is an important medication used primarily for treating patients with hypothyroidism. Levothyroxine sodium tablets have been recalled many times since their 1955 introduction to the US market. These recalls resulted from the failure of lots to meet their content uniformity and potency specifications. The purpose of this study is to test the hypothesis that the chemical stability of levothyroxine sodium pentahydrate is compromised upon exposing the dehydrated substance to molecular oxygen. The impact of temperature, oxygen and humidity storage conditions on the stability of solid-state levothyroxine sodium was examined. After exposure to these storage conditions for selected periods of time, high performance liquid chromatography (HPLC) was used to quantify the formation of impurities. The results showed that levothyroxine sodium samples degraded significantly over a 32-day test period when subjected to dry conditions in the presence of molecular oxygen. However, dehydrated samples remained stable when oxygen was removed from the storage chamber. Furthermore, hydrated samples were stable in the presence of oxygen and in the absence of oxygen. These results reveal conditions that will degrade levothyroxine sodium pentahydrate and elucidate measures that can be taken to stabilize the drug substance.

The effect of zeolite treatment by acids on sodium adsorption ratio of coal seam gas water.

PubMed

Wang, Xiaoyu; Ozdemir, Orhan; Hampton, Marc A; Nguyen, Anh V; Do, Duong D

2012-10-15

Many coal seam gas (CSG) waters contain a sodium ion concentration which is too high relative to calcium and magnesium ions for environment acceptance. Natural zeolites can be used as a cheap and effective method to control sodium adsorption ratio (SAR, which is a measure of the relative preponderance of sodium to calcium and magnesium) due to its high cation exchange capacity. In this study, a natural zeolite from Queensland was examined for its potential to treat CSG water to remove sodium ions to lower SAR and reduce the pH value. The results demonstrate that acid activated zeolite at 30%wt solid ratio can reduce the sodium content from 563.0 to 182.7 ppm; the pH from 8.74 to 6.95; and SAR from 70.3 to 18.5. Based on the results of the batch experiments, the sodium adsorption capacity of the acid-treated zeolite is three times greater than that of the untreated zeolite. Both the untreated and acid-treated zeolite samples were characterized using zeta potential, surface characterization, DTA/TG and particle size distribution in order to explain their adsorption behaviours. Copyright © 2012 Elsevier Ltd. All rights reserved.

The biopsychology of salt hunger and sodium deficiency

PubMed Central

Hurley, Seth W.; Johnson, Alan Kim

2015-01-01

Sodium is a necessary dietary macromineral that tended to be sparsely distributed in mankind’s environment in the past. Evolutionary selection pressure shaped physiological mechanisms including hormonal systems and neural circuits that serve to promote sodium ingestion. Sodium deficiency triggers the activation of these hormonal systems and neural circuits to engage motivational processes that elicit a craving for salty substances and a state of reward when salty foods are consumed. Sodium deficiency also appears to be associated with aversive psychological states including anhedonia, impaired cognition, and fatigue. Under certain circumstances the psychological processes that promote salt intake can become powerful enough to cause “salt gluttony,” or salt intake far in excess of physiological need. The present review discusses three aspects of the biopsychology of salt hunger and sodium deficiency: 1) the psychological processes that promote salt intake during sodium deficiency, 2) the effects of sodium deficiency on mood and cognition, and 3) the sensitization of sodium appetite as a possible cause of salt gluttony. PMID:25572931

Sodium: How to Tame Your Salt Habit

MedlinePlus

... soups, fast foods, and prepared dinners, such as pasta, meat and egg dishes. Natural sources. Some foods ... Better yet, buy plain whole-grain rice and pasta instead of products that have added seasonings. Remove ...

Role of U(VI) Reduction by Geobacter species

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

Lovely, Derrick

2008-12-23

Previous work had suggested that Acholeplasma palmae has a higher capacity for uranium sorption than other bacteria studied. Sorption studies were performed with cells in suspension in various solutions containing uranium, and results were used to generate uranium-biosorption isotherms. Results from this study showed that the U(VI) sorption capacity of G. uraniireducens was relatively similar in simple solutions, such as sodium chloride or bicarbonate. However, this ability to sorb uranium significantly decreased in groundwater. This suggested that certain chemicals present in the groundwater were inhibiting the ability of cell components of Geobacter to adsorb uranium. It was hypothesized that uraniummore » removal would also be diminished in the bicarbonate solution. However, this did not seem to be the case, as uranium was as easily removed in the bicarbonate solution as in the sodium chloride solution.« less

Biofilm removal by 6% sodium hypochlorite activated by different irrigation techniques.

PubMed

Ordinola-Zapata, R; Bramante, C M; Aprecio, R M; Handysides, R; Jaramillo, D E

2014-07-01

To compare the removal of biofilm utilizing four irrigation techniques on a bovine root canal model. Fifty dentine specimens (2 × 2 mm) were infected with biofilm. The samples were then adapted to previously created cavities in the bovine model. The root canals were irrigated twice with 2 mL of 6% sodium hypochlorite for 2 min (4 min total). Following initial irrigation, the different treatment modalities were introduced for 60 s (3 × 20 s intervals). The evaluated techniques were needle irrigation, Endoactivator (Dentsply Tulsa Dental, Tulsa, OK, USA), passive ultrasonic irrigation and laser-activated irrigation (photon-induced photoacoustic streaming). The controls were irrigated with distilled water and conventional needle irrigation. Subsequently, the dentine samples were separated from the model and analysed using a scanning electron microscope (SEM). Fifteen operative fields were scanned per block, and SEM pictures were captured. Two calibrated evaluators examined the images and collected data using a four-degree scale. Nonparametric tests were used to evaluate for statistical significance amongst the groups. The group undergoing laser-activated irrigation using photon-induced photoacoustic streaming exhibited the most favourable results in the removal of biofilm. Passive ultrasonic irrigation scores were significantly lower than both the Endoactivator and needle irrigation scores. Sonic and needle irrigation were not significantly different. The least favourable results were found in the control group. Laser activation of 6% sodium hypochlorite significantly improved the cleaning of biofilm-infected dentine followed by passive ultrasonic irrigation. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Adsorption of sodium dodecylbenzenesulfonate on activated carbons: effects of solution chemistry and presence of bacteria.

PubMed

Bautista-Toledo, M I; Méndez-Díaz, J D; Sánchez-Polo, M; Rivera-Utrilla, J; Ferro-García, M A

2008-01-01

The objective of the present investigation was to determine the effectiveness of activated carbon in removing sodium dodecylbenzenesulfonate (SDBS) and to analyze the chemical and textural characteristics of the activated carbons that are involved in the adsorption process. Studies were also performed on the influence of operational variables (pH, ionic strength, and presence of microorganisms) and on the kinetics and interactions involved in the adsorption of this pollutant on activated carbon. The kinetics study of SDBS adsorption revealed no problems in its diffusion on any of the activated carbons studied, and Weisz-Prater coefficient (C WP) values were considerably lower than unity for all activated carbons studied. SDBS adsorption isotherms on these activated carbons showed that: (i) adsorption capacity of activated carbons was very high (260-470 mg/g) and increased with larger surface area; and (ii) dispersive interactions between SDBS and carbon surface were largely responsible for the adsorption of this pollutant. SDBS adsorption was not significantly affected by the solution pH, indicating that electrostatic adsorbent-adsorbate interactions do not play an important role in this process. The presence of electrolytes (NaCl) in the medium favors SDBS adsorption, accelerating the process and increasing adsorption capacity. Under the working conditions used, SDBS is not degraded by bacteria; however, the presence of bacteria during the process accelerates and increases SDBS adsorption on the activated carbon. Microorganism adsorption on the activated carbon surface increases its hydrophobicity, explaining the results observed.

Molecular mass determination and assay of venom hyaluronidases by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

PubMed

Cevallos, M A; Navarro-Duque, C; Varela-Julia, M; Alagon, A C

1992-08-01

We describe a procedure for molecular mass determination of hyaluronidases present in animal venoms from different families. Hyaluronidases can be revealed, following their electrophoretic separation in sodium dodecyl sulfate-polyacrylamide gel containing hyaluronic acid, by incubating the gel in Triton X-100 to remove sodium dodecyl sulfate and restore in situ enzyme activity. This method allows the detection of as little as 0.025 turbidity-reducing units after 2 hr incubation. All the hyaluronidases from the analyzed invertebrate venoms had a mass below 50,000 and showed only one component, while those from vertebrate venoms were more than 60,000 and in many instances contained more than one form.

Permeabilization and recovery of the stratum corneum in vivo: the synergy of photomechanical waves and sodium lauryl sulfate.

PubMed

Lee, S; McAuliffe, D J; Kollias, N; Flotte, T J; Doukas, A G

2001-01-01

Photomechanical waves render the stratum corneum permeable and allow macromolecules to diffuse into the epidermis and dermis. The aim of this study was to investigate the combined action of photomechanical waves and sodium lauryl sulfate, an anionic surfactant, for transdermal delivery. A single photomechanical wave was applied to the skin of rats in the presence of sodium lauryl sulfate. The sodium lauryl sulfate solution was removed and aqueous solutions of rhodamine-B dextran (40 kDa molecular weight) were applied to the skin at time points 2, 30, and 60 minutes post-exposure. The presence of rhodamine-B dextran in the skin was measured by fluorescence emission spectroscopy in vivo and fluorescence microscopy of frozen biopsies. The use of sodium lauryl sulfate delayed the recovery of the stratum corneum barrier and extended the time available for the diffusion of dextran through it. The combination of photomechanical waves and surfactants can enhance transdermal drug delivery. Copyright 2001 Wiley-Liss, Inc.

Qualitative comparison of sonic or laser energisation of 4% sodium hypochlorite on an Enterococcus faecalis biofilm grown in vitro.

PubMed

Seet, Aaron N; Zilm, Peter S; Gully, Neville J; Cathro, Peter R

2012-12-01

The effectiveness of sonic activation, laser activation and syringe irrigation of 4% sodium hypochlorite in removing an Enterococcus faecalis biofilm was compared. Biofilms were grown in extracted human single rooted teeth using a flow cell apparatus. After 4 weeks' growth, teeth were subjected to each treatment using 4% sodium hypochlorite and radicular dentinal surfaces of the root canals were analysed by scanning electron microscopy. Results showed that sonic activation and syringe irrigation with sodium hypochlorite showed reduced numbers of bacterial cells on the radicular dentine but were not effective in eliminating E. faecalis in the dentinal tubules. Laser activation of sodium hypochlorite resulted in clean dentine walls and undetectable levels of bacteria within dentinal tubules. Qualitatively, sonic or laser activation of 4% NaOCl resulted in greater bacterial reduction compared with syringe irrigation, with laser activation producing the greatest overall reduction. © 2012 The Authors. Australian Endodontic Journal © 2012 Australian Society of Endodontology.

pH-adjustment strategy for volatile fatty acid production from high-strength wastewater for biological nutrient removal.

PubMed

Xie, Li; Liu, Hui; Chen, Yin-Guang; Zhou, Qi

2014-01-01

Volatile fatty acid (VFA) production from three types of high-strength organic wastewater (cassava thin stillage, starch wastewater and yellow-wine processing wastewater) were compared. The results showed that cassava thin stillage was the most suitable substrate, based on its high specific VFA production (0.68 g chemical oxygen demand (COD)/g initial soluble chemical oxygen demand (SCOD)) and yield (0.72 g COD/g SCOD) as well as low nutrient content in the substrate and fermented liquid. The acid fermented cassava thin stillage was evaluated and compared with sodium acetate in a sequencing batch reactor system. Total nitrogen removal efficiency was higher with fermented cassava thin stillage than with the sodium acetate. The effects of pH and a pH-adjustment strategy on VFA production and composition were determined using cassava thin stillage. At an initial pH range of 7-11, a relatively high VFA concentration of about 9 g COD/L was obtained. The specific VFA production (g COD/g initial SCOD) increased from 0.27 to 0.47 to 0.67 at pH 8 and from 0.26 to 0.68 to 0.81 at pH 9 (initial pH, interval pH, and constant pH adjustment, respectively). The dominant VFA species changed significantly with the increasing frequency of the pH adjustment. Further studies will examine the metabolic pathways responsible for VFA composition.

Comparison between electrocoagulation and chemical precipitation for metals removal from acidic soil leachate.

PubMed

Meunier, Nathalie; Drogui, Patrick; Montané, Camille; Hausler, Robert; Mercier, Guy; Blais, Jean-François

2006-09-01

This paper provides a quantitative comparison between electrocoagulation and chemical precipitation based on heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) removal from acidic soil leachate (ASL) at the laboratory pilot scale. Chemical precipitation was evaluated using either calcium hydroxide or sodium hydroxide, whereas electrocoagulation was evaluated via an electrolytic cell using mild steel electrodes. Chemical precipitation was as effective as electrocoagulation in removing metals from ASL having low contamination levels (30 mg Pbl(-1) and 18 mg Znl(-1)). For ASL enriched with different metals (each concentration of metals was initially adjusted to 100 mg l(-1)), the residual Cr, Cu, Pb and Zn concentrations at the end of the experiments were below the acceptable level recommended for discharge in sewage urban works (more than 99.8% of metal was removed) using either electrocoagulation or chemical precipitation. Cd was more effectively removed by electrochemical treatment, whereas Ni was easily removed by chemical treatment. The cost for energy, chemicals and disposal of metallic residue of electrocoagulation process ranged from USD 8.83 to 13.95 tds(-1), which was up to five times lower than that recorded using chemical precipitation. Highly effective electrocoagulation was observed as the ASL was specifically enriched with high concentration of Pb (250-2000 mg Pbl(-1)). More than 99.5% of Pb was removed regardless of the initial Pb concentration imposed in ASL and, in all cases, the residual Pb concentrations (0.0-1.44 mg l(-1)) were below the limiting value (2.0 mg l(-1)) for effluent discharge in sewage works.

Biochemical analysis of human milk treated with sodium dodecyl sulfate, an alkyl sulfate microbicide that inactivates human immunodeficiency virus type 1.

PubMed

Hartmann, Sandra Urdaneta; Wigdahl, Brian; Neely, Elizabeth B; Berlin, Cheston M; Schengrund, Cara-Lynne; Lin, Hung-Mo; Howett, Mary K

2006-02-01

Reduction of transmission of human immunodeficiency virus type 1 (HIV-1) through human milk is needed. Alkyl sulfates such as sodium dodecyl sulfate (SDS) are microbicidal against HIV-1 at low concentrations, have little to no toxicity, and are inexpensive. The authors have reported that treatment of HIV-1-infected human milk with < or = 1% (10 mg/mL) SDS for 10 minutes inactivates cell-free and cell-associated virus. The SDS can be removed with a commercially available resin after treatment without recovery of viral infectivity. In this article, the authors report results of selective biochemical analyses (ie, protein, immunoglobulins, lipids, cells, and electrolytes) of human milk subjected to SDS treatment and removal. The SDS treatment or removal had no significant effects on the milk components studied. Therefore, the use of alkyl sulfate microbicides to treat milk from HIV-1-positive women may be a simple, practical, and nutritionally sound way to prevent or reduce transmission of HIV-1 while still feeding with mother's own milk.

2,4-Dinitrophenylhydrazine functionalized sodium dodecyl sulfate-coated magnetite nanoparticles for effective removal of Cd(II) and Ni(II) ions from water samples.

PubMed

Sobhanardakani, Soheil; Zandipak, Raziyeh

2015-07-01

2,4-Dinitrophenylhydrazine immobilized on sodium dodecyl sulfate (SDS)-coated magnetite and was used for removal of Cd(II) and Ni(II) ions from aqueous solution. The prepared product was characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The size of the nanoparticles according to SEM was obtained around 20-35 nm. In batch tests, the effects of pH, contact time, initial metal concentration, and temperature were studied. The kinetic and equilibrium data were modeled with recently developed models. The adsorption kinetics and isotherms were well fitted by the fractal-like pseudo-second-order model and Langmuir-Freundlich model, respectively. Maximum adsorption capacity by this adsorbent is 255.1 mg g(-1) for Cd(II) ion and 319.6 mg g(-1) for Ni(II) ion at pH 7.0 and 25 °C. The method was successfully applied to the removal of metal cations in real samples (tap water, river water, and petrochemical wastewater).

Sodium monitoring in commercially processed and restaurant foods.

PubMed

Ahuja, Jaspreet K C; Pehrsson, Pamela R; Haytowitz, David B; Wasswa-Kintu, Shirley; Nickle, Melissa; Showell, Bethany; Thomas, Robin; Roseland, Janet; Williams, Juhi; Khan, Mona; Nguyen, Quynhanh; Hoy, Kathy; Martin, Carrie; Rhodes, Donna; Moshfegh, Alanna; Gillespie, Cathleen; Gunn, Janelle; Merritt, Robert; Cogswell, Mary

2015-03-01

Most sodium in the US diet comes from commercially processed and restaurant foods. Sodium reduction in these foods is key to several recent public health efforts. The objective was to provide an overview of a program led by the USDA, in partnership with other government agencies, to monitor sodium contents in commercially processed and restaurant foods in the United States. We also present comparisons of nutrients generated under the program to older data. We track ∼125 commercially processed and restaurant food items ("sentinel foods") annually using information from food manufacturers and periodically by nationwide sampling and laboratory analyses. In addition, we monitor >1100 other commercially processed and restaurant food items, termed "priority-2 foods" (P2Fs) biennially by using information from food manufacturers. These foods serve as indicators for assessing changes in the sodium content of commercially processed and restaurant foods in the United States. We sampled all sentinel foods nationwide and reviewed all P2Fs in 2010-2013 to determine baseline sodium concentrations. We updated sodium values for 73 sentinel foods and 551 P2Fs in the USDA's National Nutrient Database for Standard Reference (releases 23-26). Sodium values changed by at least 10% for 43 of the sentinel foods, which, for 31 foods, including commonly consumed foods such as bread, tomato catsup, and potato chips, the newer sodium values were lower. Changes in the concentrations of related nutrients (total and saturated fat, total sugar, potassium, or dietary fiber) that were recommended by the 2010 Dietary Guidelines for Americans for reduced or increased consumption accompanied sodium reduction. The results of sodium reduction efforts, based on resampling of the sentinel foods or re-review of P2Fs, will become available beginning in 2015. This monitoring program tracks sodium reduction efforts, improves food composition databases, and strengthens national nutrition monitoring. © 2015 American Society for Nutrition.

Sodium monitoring in commercially processed and restaurant foods

PubMed Central

Ahuja, Jaspreet KC; Pehrsson, Pamela R; Haytowitz, David B; Wasswa-Kintu, Shirley; Nickle, Melissa; Showell, Bethany; Thomas, Robin; Roseland, Janet; Williams, Juhi; Khan, Mona; Nguyen, Quynhanh; Hoy, Kathy; Martin, Carrie; Rhodes, Donna; Moshfegh, Alanna; Gillespie, Cathleen; Gunn, Janelle; Merritt, Robert; Cogswell, Mary

2015-01-01

Background Most sodium in the US diet comes from commercially processed and restaurant foods. Sodium reduction in these foods is key to several recent public health efforts. Objective The objective was to provide an overview of a program led by the USDA, in partnership with other government agencies, to monitor sodium contents in commercially processed and restaurant foods in the United States. We also present comparisons of nutrients generated under the program to older data. Design We track ∼125 commercially processed and restaurant food items (“sentinel foods”) annually using information from food manufacturers and periodically by nationwide sampling and laboratory analyses. In addition, we monitor >1100 other commercially processed and restaurant food items, termed “priority-2 foods” (P2Fs) biennially by using information from food manufacturers. These foods serve as indicators for assessing changes in the sodium content of commercially processed and restaurant foods in the United States. We sampled all sentinel foods nationwide and reviewed all P2Fs in 2010–2013 to determine baseline sodium concentrations. Results We updated sodium values for 73 sentinel foods and 551 P2Fs in the USDA’s National Nutrient Database for Standard Reference (releases 23–26). Sodium values changed by at least 10% for 43 of the sentinel foods, which, for 31 foods, including commonly consumed foods such as bread, tomato catsup, and potato chips, the newer sodium values were lower. Changes in the concentrations of related nutrients (total and saturated fat, total sugar, potassium, or dietary fiber) that were recommended by the 2010 Dietary Guidelines for Americans for reduced or increased consumption accompanied sodium reduction. The results of sodium reduction efforts, based on resampling of the sentinel foods or re-review of P2Fs, will become available beginning in 2015. Conclusion This monitoring program tracks sodium reduction efforts, improves food composition databases, and strengthens national nutrition monitoring. PMID:25733648

Living with a leaky skin: upregulation of ion transport proteins during sloughing.

PubMed

Wu, Nicholas C; Cramp, Rebecca L; Franklin, Craig E

2017-06-01

Amphibian skin is a multifunctional organ providing protection from the external environment and facilitating the physiological exchange of gases, water and salts with the environment. In order to maintain these functions, the outer layer of skin is regularly replaced in a process called sloughing. During sloughing, the outermost layer of the skin is removed in its entirety, which has the potential to interfere with skin permeability and ion transport, disrupting homeostasis. In this study, we measured, in vivo , the effects of sloughing on the cutaneous efflux of ions in toads Rhinella marina kept in freshwater conditions. We also measured transepithelial potential, cutaneous resistance, active ion transport and the distribution, abundance and gene expression of the key ion transport proteins sodium-potassium ATPase (NKA) and epithelial sodium channel (ENaC) during sloughing. We hypothesised that the increase in transepithelial efflux of ions during sloughing is a consequence of increased permeability and/or a reduction in the abundance or expression of cutaneous ion transport proteins, resulting in disruption of internal ion homeostasis. There was a significant increase in sodium and chloride efflux during sloughing in R. marina However, although in vitro skin resistance decreased after sloughing, active sodium transport increased commensurate with an increase in NKA and ENaC protein abundance in the skin. These changes in skin function associated with sloughing did not affect the maintenance of internal electrolyte homeostasis. These results suggest that during sloughing, amphibians actively maintain internal homeostasis by increasing cutaneous rates of ion uptake. © 2017. Published by The Company of Biologists Ltd.

Evaluation of the topical effect of alendronate on the root surface of extracted and replanted teeth. Microscopic analysis on rats' teeth.

PubMed

Lustosa-Pereira, Adriana; Garcia, Roberto Brandão; de Moraes, Ivaldo Gomes; Bernardineli, Norberti; Bramante, Clovis Monteiro; Bortoluzzi, Eduardo Antunes

2006-02-01

The treatment of choice for tooth avulsion is replantation. The ideal replantation should be realized as quickly as possible, or at least, the avulsed tooth should be kept in an adequate solution to preserve the periodontal ligament attached to the root. If that is not possible, treatment of the radicular surface should be done in order to prevent radicular resorption. The purpose of this study was to test sodium alendronate as a substance for topical treatment of the radicular surface of avulsed teeth in an attempt to prevent the occurrence of dental resorptions. Fifty-four rat maxillary right central incisors were extracted and replanted. Group I--extra-alveolar dry period of 15 min, intracanal dressing with calcium hydroxide (CALEN, S.S. White, Artigos Dentários LTDA, Rio de Janeiro, Brazil) and replantation; Groups II and III - extra-alveolar dry periods of 30 and 60 min, respectively, immersion in 1% sodium hypochlorite for 30 min for removal of the periodontal ligament, washing in saline solution for 5 min, and treatment of the radicular surface with 3.2 mg/l sodium alendronate solution for 10 min. Intracanal dressing with calcium hydroxide and replantation followed. At 15, 60, and 90 days post-reimplantation, the animals were killed and the samples obtained and processed for microscopic analysis. The results indicated that sodium alendronate was able to reduce the incidence of radicular resorption, but not of dental ankylosis. No significant differences were observed regarding variations in the extra-alveolar periods among the groups.

In vitro Comparison of Debris Removal Using Various Adjunct Irrigation Devices

DTIC Science & Technology

2016-06-09

either by activating standing irrigant or by concurrently activating and delivering a volume of irrigant. The amount of residual bacteria is a...Thus, adjuncts which deliver irrigants as they are ultrasonically activated may be more effective at removing debris and bacteria than those which...do not. Two systems which activate standing sodium hypochlorite are the EndoActivator system (Dentsply, Tulsa, OK) and the EndoUltra system (Vista

RARE-EARTH METAL FISSION PRODUCTS FROM LIQUID U-Bi

DOEpatents

Wiswall, R.H.

1960-05-10

Fission product metals can be removed from solution in liquid bismuth without removal of an appreciable quantity of uranium by contacting the liquid metal solution with fused halides, as for example, the halides of sodium, potassium, and lithium and by adding to the contacted phases a quantity of a halide which is unstable relative to the halides of the fission products, a specific unstable halide being MgCl/sub 3/.

Design and fabrication of an innovative and environmental friendly adsorbent for boron removal.

PubMed

Wei, Yu-Ting; Zheng, Yu-Ming; Chen, J Paul

2011-03-01

Boron can pose adverse effects on human beings and plants species. It exists in various water environments and is difficult to be removed by conventional technologies. In this study, an efficient and environmental friendly sorbent was fabricated by the functionalization of a natural biopolymer, chitosan, with N-methylglucamine through atom transfer radical polymerization. The SEM and BET studies revealed that the sorbent had a rougher surface and a more porous structure than the chitosan. At the optimum neutral pH, the maximum sorption capacity was as high as 3.25 mmol/g, much higher than the commercial boron selective resins (e.g., Amberlite IRA-743) and many other synthesized sorbents. Almost 90% of boron sorption occurred within 8 h and the equilibrium was established in 12 h, which was well described by an intraparticle surface diffusion model. The presence of sodium chloride and sodium nitrate had no effect on the boron removal. The boron concentration in seawater could be reduced to less than 0.5 mg/L from 4.8 mg/L when a sorbent dosage of 1.2 g/L was used. It was therefore concluded that the sorption technology from this study could be promising for boron removal from aqueous solutions. Copyright © 2011 Elsevier Ltd. All rights reserved.

Energy and material balance of CO2 capture from ambient air.

PubMed

Zeman, Frank

2007-11-01

Current Carbon Capture and Storage (CCS) technologies focus on large, stationary sources that produce approximately 50% of global CO2 emissions. We propose an industrial technology that captures CO2 directly from ambient air to target the remaining emissions. First, a wet scrubbing technique absorbs CO2 into a sodium hydroxide solution. The resultant carbonate is transferred from sodium ions to calcium ions via causticization. The captured CO2 is released from the calcium carbonate through thermal calcination in a modified kiln. The energy consumption is calculated as 350 kJ/mol of CO2 captured. It is dominated by the thermal energy demand of the kiln and the mechanical power required for air movement. The low concentration of CO2 in air requires a throughput of 3 million cubic meters of air per ton of CO2 removed, which could result in significant water losses. Electricity consumption in the process results in CO2 emissions and the use of coal power would significantly reduce to net amount captured. The thermodynamic efficiency of this process is low but comparable to other "end of pipe" capture technologies. As another carbon mitigation technology, air capture could allow for the continued use of liquid hydrocarbon fuels in the transportation sector.

Quantitative PCR and disaccharide profiling to characterize the animal origin of low-molecular-weight heparins.

PubMed

Houiste, Céline; Auguste, Cécile; Macrez, Céline; Dereux, Stéphanie; Derouet, Angélique; Anger, Pascal

2009-02-01

Low-molecular-weight heparins (LMWHs) are widely used in the management of thrombosis and acute coronary syndromes. They are obtained by the enzymatic or chemical depolymerization of porcine intestinal heparin. Enoxaparin sodium, a widely used LMWH, has a unique and reproducible oligosaccharide profile which is determined by the origin of the starting material and a tightly controlled manufacturing process. Although other enoxaparin-like LMWHs do exist, specific release criteria including the origin of the crude heparin utilized for their production, have not been established. A quantitative polymerase chain reaction method has been developed to ensure the purity of the porcine origin of crude heparin, with a DNA detection limit as low as 1 ppm for bovine, or 10 ppm for ovine contaminants. This method is routinely used as the release acceptance criterion during enoxaparin sodium manufacturing. Furthermore, when the process removes DNA, other analytical techniques can be used to assess any contamination. Disaccharide profiling after exhaustive depolymerization can determine the presence of at least 10% bovine or 20% ovine material; multivariate analysis is useful to perform the data analysis. Consistent with the availability of newer technology, these methods should be required as acceptance criteria for crude heparins used in the manufacture of LMWHs to ensure their safety, quality, and immunologic profile.

Application of three tailing-based composites in treating comprehensive electroplating wastewater.

PubMed

Liu, Hongbo; Zhu, Mengling; Gao, Saisai

2014-01-01

Heavy metals and chemical oxygen demand (COD) are major challenging pollutants for most electroplating wastewater treatment plants. A novel composite material, prepared with a mixture of calcium and sodium compounds and tailings, was simply mixed by ratios and used to treat a comprehensive electroplating wastewater with influent COD, total copper (T-Cu), and total nickel (T-Ni) respectively as 690, 4.01, and 20.60 mg/L on average. Operational parameters, i.e. the contact time, pH, mass ratio of calcium and sodium compounds and tailings, were optimized as 30 min, 10.0, and 4:2:1. Removal rates for COD, T-Cu, and T-Ni could reach 71.8, 90.5, and 98.1%, respectively. No significant effect of initial concentrations on removal of T-Cu and T-Ni was observed for the composite material. The adsorption of Cu(II) and Ni(II) on the material fitted Langmuir and Freundlich isotherms respectively. Weight of waste sludge from the calcium/sodium-tailing system after reaction was 10% less than that from the calcium-tailing system. The tailing-based composite is cost-effective in combating comprehensive electroplating pollution, which shows a possibility of applying the tailings in treating electroplating wastewater.

An Interagency Study of Depainting Techniques

NASA Technical Reports Server (NTRS)

Cook, B.

1997-01-01

Many popular and widely used paint stripping products now contain methylene chloride as their active ingredient. However, the Environmental Protection Agency (EPA) will critically curb the use of methylene chloride under an aerospace national emission standard for hazardous air pollutants (NESHAP) within the next 2-1/2 years. An effort is underway to identify and evaluate alternative depainting technologies emphasizing those believed to be both effective and environmentally benign. On behalf of the EPA and in cooperation with the U. S. Air Force (USAF), the National Aeronautics and Space Administration (NASA) is conducting a technical assessment of nine alternative technologies (i.e.: chemical stripping, two CO2 blasting processes, FLASHJET(TM) coating removal, laser stripping, plastic media blasting, sodium bicarbonate wet stripping, high-pressure water stripping, and wheat starch blasting). These depainting processes represent five removal method categories, namely abrasive, impact, cryogenic, thermal, and/or molecular bonding dissociation. This paper discusses the test plan and parameters for this interagency study. Several thicknesses of clad and non-clad aluminum substrates were used to prepare test specimens, which have been cut, cleaned, painted, and environmentally aged. Each depainting process has been assigned a specimen lot, which is now undergoing an initial strip cycle. Metallurgical impacts will be determined after these specimens complete five cycles of preparation and stripping.

Reducing Sodium in Foods: The Effect on Flavor

PubMed Central

Liem, Djin Gie; Miremadi, Fatemeh; Keast, Russell S. J.

2011-01-01

Sodium is an essential micronutrient and, via salt taste, appetitive. High consumption of sodium is, however, related to negative health effects such as hypertension, cardiovascular diseases and stroke. In industrialized countries, about 75% of sodium in the diet comes from manufactured foods and foods eaten away from home. Reducing sodium in processed foods will be, however, challenging due to sodium’s specific functionality in terms of flavor and associated palatability of foods (i.e., increase of saltiness, reduction of bitterness, enhancement of sweetness and other congruent flavors). The current review discusses the sensory role of sodium in food, determinants of salt taste perception and a variety of strategies, such as sodium replacers (i.e., potassium salts) and gradual reduction of sodium, to decrease sodium in processed foods while maintaining palatability. PMID:22254117

Effect of air polishing with glycine powder on titanium abutment surfaces.

PubMed

Cochis, Andrea; Fini, Milena; Carrassi, Antonio; Migliario, Mario; Visai, Livia; Rimondini, Lia

2013-08-01

The aim of the present study was to evaluate morphological changes induced by glycine powder air polishing on titanium surfaces and its effect on bacteria recolonization in comparison with sodium bicarbonate powder. 5 mm wide and 1 mm thick titanium grade II disks were divided into three groups of treatments: (i) no treatment; (ii) air polishing with glycine powder; (iii) air polishing with sodium bicarbonate powder. Specimens were characterized by laser profilometry, scanning electron microscopy (SEM) and then installed onto removable appliances worn for 24 h by healthy volunteers. Surface contamination was evaluated using SEM and counting the number of colony forming units (CFU). SEM observation revealed an increased roughness with the formation of craters on samples treated with sodium bicarbonate powder, while not in glycine ones. Statistical analysis failed to show significant differences of both Ra and Rmax parameters in treated groups. SEM observation of specimens surfaces, after 24 h of permanence in the oral cavity, showed a higher contamination of the disks treated with sodium bicarbonate compared with those not treated (P < 0.05). Conversely, the group treated with glycine showed the lower contamination if compared with bicarbonate-treated group (P < 0.05). Air polishing with glycine powder may be considered as a better method to remove plaque from dental implant because glycine is less aggressive than sodium bicarbonate powder. Moreover, the use of glycine powder seems to have an active role on the inhibition of bacterial recolonization of implants in a short test period (24 h). Further studies are needed to demonstrate the bacteriostatic properties of glycine, envisaged on the basis of reduced contamination of the disks polished with glycine compared with those not treated. © 2012 John Wiley & Sons A/S.

Research on the effect of alkali roasting of copper dross on leaching rate of indium

NASA Astrophysics Data System (ADS)

Dafang, Liu; Fan, Xingxiang; Shi, Yifeng; Yang, Kunbin

2017-11-01

The byproduct copper dross produced during refining crude lead was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and fluorescence spectrometer (XRF), which showed that copper dross mainly contained lead, copper, zinc, arsenic, antimony, bismuth, sulfur and a small amount of indium and silver etc. The mineralogical phase change of oxidation roasting of copper dross by adding sodium hydroxide was analyzed with the help of XRD and SEM. The effects of water leaching, ratio of sodium hydroxide, roasting time, and roasting temperature on leaching rate of indium were investigated mainly. The experimental results showed that phase of lead metal and sulfides of lead, copper and zinc disappeared after oxidation roasting of copper dross by adding sodium hydroxide, new phase of oxides of lead, copper, zinc and sodium salt of arsenic and antimony appeared. Water leaching could remove arsenic, and acid leaching residue obtained was then leached with acid. The leaching rate of indium was higher 6.98% compared with alkali roasting of copper dross-acid leaching. It showed that removing arsenic by water leaching and acid leaching could increase the leaching rate of indium and be beneficial to reducing subsequent acid consumption of extracting indium by acid leaching. The roasting temperature had a significant effect on the leaching rate of indium, and leaching rate of indium increased with the rise of roasting temperature. When roasting temperature ranged from 450°C to 600°C, leaching rate of indium increased significantly with the rise of roasting temperature. When roasting temperature rose from 450°C to 600°C, leaching rate of indium increased by 60.29%. The amount of sodium hydroxide had an significant effect on the leaching rate of indium, and the leaching of indium increased with the increase of the amount of sodium hydroxide, and the leaching rate of indium was obviously higher than that of copper dross blank roasting and acid leaching.

The Sodium Content of Processed Foods in South Africa during the Introduction of Mandatory Sodium Limits.

PubMed

Peters, Sanne A E; Dunford, Elizabeth; Ware, Lisa J; Harris, Teresa; Walker, Adele; Wicks, Mariaan; van Zyl, Tertia; Swanepoel, Bianca; Charlton, Karen E; Woodward, Mark; Webster, Jacqui; Neal, Bruce

2017-04-20

In June 2016, the Republic of South Africa introduced legislation for mandatory limits for the upper sodium content permitted in a wide range of processed foods. We assessed the sodium levels of packaged foods in South Africa during the one-year period leading up to the mandatory implementation date of the legislation. Data on the nutritional composition of packaged foods was obtained from nutrition information panels on food labels through both in-store surveys and crowdsourcing by users of the HealthyFood Switch mobile phone app between June 2015 and August 2016. Summary sodium levels were calculated for 15 food categories, including the 13 categories covered by the sodium legislation. The percentage of foods that met the government's 2016 sodium limits was also calculated. 11,065 processed food items were included in the analyses; 1851 of these were subject to the sodium legislation. Overall, 67% of targeted foods had a sodium level at or below the legislated limit. Categories with the lowest percentage of foods that met legislated limits were bread (27%), potato crisps (41%), salt and vinegar flavoured snacks (42%), and raw processed sausages (45%). About half (49%) of targeted foods not meeting the legislated limits were less than 25% above the maximum sodium level. Sodium levels in two-thirds of foods covered by the South African sodium legislation were at or below the permitted upper levels at the mandatory implementation date of the legislation and many more were close to the limit. The South African food industry has an excellent opportunity to rapidly meet the legislated requirements.

Evolutionarily conserved intracellular gate of voltage-dependent sodium channels

NASA Astrophysics Data System (ADS)

Oelstrom, Kevin; Goldschen-Ohm, Marcel P.; Holmgren, Miguel; Chanda, Baron

2014-03-01

Members of the voltage-gated ion channel superfamily (VGIC) regulate ion flux and generate electrical signals in excitable cells by opening and closing pore gates. The location of the gate in voltage-gated sodium channels, a founding member of this superfamily, remains unresolved. Here we explore the chemical modification rates of introduced cysteines along the S6 helix of domain IV in an inactivation-removed background. We find that state-dependent accessibility is demarcated by an S6 hydrophobic residue; substituted cysteines above this site are not modified by charged thiol reagents when the channel is closed. These accessibilities are consistent with those inferred from open- and closed-state structures of prokaryotic sodium channels. Our findings suggest that an intracellular gate composed of a ring of hydrophobic residues is not only responsible for regulating access to the pore of sodium channels, but is also a conserved feature within canonical members of the VGIC superfamily.

Hydrogen generation systems utilizing sodium silicide and sodium silica gel materials

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

Wallace, Andrew P.; Melack, John M.; Lefenfeld, Michael

Systems, devices, and methods combine reactant materials and aqueous solutions to generate hydrogen. The reactant materials can sodium silicide or sodium silica gel. The hydrogen generation devices are used in fuels cells and other industrial applications. One system combines cooling, pumping, water storage, and other devices to sense and control reactions between reactant materials and aqueous solutions to generate hydrogen. Multiple inlets of varied placement geometries deliver aqueous solution to the reaction. The reactant materials and aqueous solution are churned to control the state of the reaction. The aqueous solution can be recycled and returned to the reaction. One systemmore » operates over a range of temperatures and pressures and includes a hydrogen separator, a heat removal mechanism, and state of reaction control devices. The systems, devices, and methods of generating hydrogen provide thermally stable solids, near-instant reaction with the aqueous solutions, and a non-toxic liquid by-product.« less

Rupture disc

DOEpatents

Newton, Robert G.

1977-01-01

The intermediate heat transport system for a sodium-cooled fast breeder reactor includes a device for rapidly draining the sodium therefrom should a sodium-water reaction occur within the system. This device includes a rupturable member in a drain line in the system and means for cutting a large opening therein and for positively removing the sheared-out portion from the opening cut in the rupturable member. According to the preferred embodiment of the invention the rupturable member includes a solid head seated in the end of the drain line having a rim extending peripherally therearound, the rim being clamped against the end of the drain line by a clamp ring having an interior shearing edge, the bottom of the rupturable member being convex and extending into the drain line. Means are provided to draw the rupturable member away from the drain line against the shearing edge to clear the drain line for outflow of sodium therethrough.

Hydrogen generation systems utilizing sodium silicide and sodium silica gel materials

DOEpatents

Wallace, Andrew P.; Melack, John M.; Lefenfeld, Michael

2015-07-14

Systems, devices, and methods combine reactant materials and aqueous solutions to generate hydrogen. The reactant materials can sodium silicide or sodium silica gel. The hydrogen generation devices are used in fuels cells and other industrial applications. One system combines cooling, pumping, water storage, and other devices to sense and control reactions between reactant materials and aqueous solutions to generate hydrogen. Multiple inlets of varied placement geometries deliver aqueous solution to the reaction. The reactant materials and aqueous solution are churned to control the state of the reaction. The aqueous solution can be recycled and returned to the reaction. One system operates over a range of temperatures and pressures and includes a hydrogen separator, a heat removal mechanism, and state of reaction control devices. The systems, devices, and methods of generating hydrogen provide thermally stable solids, near-instant reaction with the aqueous solutions, and a non-toxic liquid by-product.

Removal of excess nutrients by Australian zeolite during anaerobic digestion of swine manure.

PubMed

Wijesinghe, D Thushari N; Dassanayake, Kithsiri B; Scales, Peter; Sommer, Sven G; Chen, Deli

2018-03-21

The objective of this study was to investigate the feasibility of using natural and NaCl-treated Australian zeolites to simultaneously remove excess nutrients from anaerobically digested swine manure. Ion adsorption and desorption properties of Australian zeolite during the anaerobic digestion of swine manure were investigated. Two experiments were conducted: the first was an adsorption experiment with multi-component solutions that corresponded with the ionic composition of swine manure digestates. The second experiment determined the effects of zeolite dose rates during anaerobic digestion of swine manure on the removal of N, P and K from solution. Adsorption isotherms confirmed selectivity for K + over NH 4 + by Australian natural and sodium zeolites. Therefore, NH 4 + removal was considerably reduced when there was simultaneous K + uptake. Natural zeolite desorbed more Ca 2+ during K + and NH 4 + adsorption than sodium zeolite. The ion exchange reaction was independent of the presence of P. P removal was very dependent on the pH of the medium. Natural Australian zeolite was shown to be a potential sorbent for the removal of NH 4 + , K + and P during the anaerobic digestion of swine manure. However, the application of high concentrations of zeolite at higher pH values (> 7.5) might not be appropriate for anaerobic digestion, because zeolite desorbed more Ca 2+ ions into the solution at the higher doses of zeolite and then availability of P for microbial growth might be reduced as a result of PO 4 3- precipitation with Ca 2+ at the higher pH.

Potential and tension changes induced by sodium removal in dog Purkinje fibres: role of an electrogenic sodium-calcium exchange.

PubMed Central

Croaboeuf, E; Gautier, P; Giuraudou, P

1981-01-01

1. Isolated dog Purkinje fibres were bathed in K-free media or in the presence of ouabain 10(-4) M in order to depress the electrogenic sodium pump activity. Membrane potential and mechanical tension were recorded in the presence of normal external sodium concentration and during lowering or removal of external Na. 2. Lowering or removal of external Na (Na being replaced by choline, Tris, sucrose or Li) induced a hyperpolarization and a contracture which reached a maximum after 1 or 2 min and then decreased progressively. Using Tris, Em increased from -40 +/- 3 to -72 +/- 10 mV (n = 39). The Na-free contracture and hyperpolarization did not occur in the absence of Na pump depression. 3. Tetrodotoxin (1.2 x 10(-5)M), Mn (4 mM), verapamil (1-4 x 10(-5) M) tetraethylammonium (5 mM), 4-aminopyridine (5 mM) and Cs (20 mM, in the presence of ouabain) did not alter the Na-free contracture and hyperpolarization. On the other hand Mn (20 mM), acid media (external pH less than 6.0) and low temperatures depressed or suppressed both the hyperpolarization and contracture. Lanthanum (0.4 mM) did not suppress the hyperpolarization and the contracture. On the contrary the Na-free contracture was generally increased in the presence of La. 4. Caffeine (10 mM) induced strong contractures with no changes in Em, thus demonstrating the possibility for the Purkinje fibers of developing contractures without concomitant hyperpolarizations. 5. It can be concluded that the Na-free contracture and hyperpolarization are not due to changes in passive conductances but are related to the functioning of an electrogenic Na-Ca exchange mechanism which carries inwardly 1 Ca and outwardly 3 or more Na. Images Fig. 1 PMID:7264984

NASA/Air Force/Environmental Protection Agency Interagency Depainting Study

NASA Technical Reports Server (NTRS)

Clark-Ingram, Marceia

1998-01-01

Many popular and widely used paint stripping products have traditionally contained methylene chloride as their main active ingredient. However, the Environmental Protection Agency (EPA) has critically curved the allowable use of methylene chloride under the National Emission Standard for Hazardous Air Pollutants regulating Aerospace Manufacturing and Rework Facilities . Compliance with this rule was mandatory by September 1998 for affected facilities. An effort is underway to identify and evaluate alternative depainting technologies emphasizing those believed both effective and environmentally benign. On behalf of the EPA and in cooperation with the United States Air Force, the National Aeronautics and Space Administration is conducting a technical assessment of several alternative technologies ( i.e. : chemical stripping, two CO2 blasting processes, CO2 xenon lamp coating removal, CO2 Laser stripping, plastic media blasting, sodium bicarbonate wet stripping, high pressure water stripping, and wheat starch blasting). These depainting processes represent five removal method categories, namely abrasive, impact, cryogenic, thermal, and/or molecular bonding dissociation. This paper discusses the test plan and parameters for this interagency study. Several thicknesses of clad and non-clad aluminum substrates were used to prepare test specimens. Each depainting process has been assigned a specimen lot, all of which have completed three to five stripping cycles. Numerous metallurgical evaluations are underway to assess the impact of these alternative depainting processes upon the structural integrity of the substrate.

Changes in Serving Size, Calories, and Sodium Content in Processed Foods From 2009 to 2015.

PubMed

Clapp, Jenifer E; Niederman, Sarah A; Leonard, Elizabeth; Curtis, Christine J

2018-03-15

Approximately 60% of the American diet comes from processed foods, which makes improving their nutritional quality important for Americans' health. The objective of this study was to measure changes in serving sizes, calories, and sodium in top-selling processed foods that were on the market in 2009 and 2015. We analyzed products in the top 80% of sales in the 54 processed food categories with consistent serving sizes and sales metrics that were on the market in both 2009 and 2015. Mean serving size, calories (per serving and density), sodium (per serving and density), and sales were calculated for 2,979 branded processed food products. For each stratification of calorie density and sodium density (decreased, increased, or did not change), we calculated the mean serving size, calorie density, sodium density, and sales for each year. From 2009 to 2015, we found decreases in serving size (-2.3%, P < .001), calories per serving (-2.0%, P < .001), calorie density (-1.1%, P < .001), sodium per serving (-7.6%, P < .001), and sodium density (-6.0%, P < .001). A decrease in calorie density did not correspond to an increase in sodium density or vice versa. A decline in sales was observed regardless of whether calorie density or sodium density decreased, increased, or did not change. Reductions in calorie and sodium density occurred in tandem, suggesting that manufacturers reformulated for more than one health goal at the same time. Instead of unintended negative consequences of encouraging companies to reformulate for one nutrient, an overall net nutritional benefit occurred.

Effect of Agitation in Alkalization Process on the Characteristics of Sodium Carboxymethyl Sago and Cassava Starches

NASA Astrophysics Data System (ADS)

Titi, C. S.; Fachrudin, R.; Ruriani, E.; Yuliasih, I.

2018-05-01

Sodium carboxymethyl starch (Sodium CMS) is a modified starch prepared by two successive processes, alkalization and etherification. Alkalization will change the activated hydroxyl group of starch to more reactive alkoxide (St-O-), and then carboxymethyl group will substitute the hydroxyl group into sodium CMS. This research investigated the effect of agitation (1000 rpm of stirring and 4000 rpm of homogenization) in alkalization process to the modification of native starch into sodium CMS. Cassava and sago starches were mixed with sodium hydroxide (1.8 and 1.9 moles per mole anhydrous glucose units). The combination of NaOH and homogenizing gave the highest degrees of substitution for cassava (DS 0.73) and sago (DS 0.55) starches. The sodium CMS characteristics (paste clarity, water and oil absorption capacities, solubility, swelling power) were a function of mixing method but not on the amount of NaOH used.

Extraction behavior of metallic contaminants and soil constituents from contaminated soils.

PubMed

Tokunaga, S; Park, S W; Ulmanu, M

2005-06-01

With an aim of developing an effective remediation technology for soils contaminated by heavy metals and metalloids, the extraction behavior of metallic contaminants as well as those of soil constituents was studied on a laboratory scale. Three contaminated soils collected from a former metal recycling plant were examined. These three soils were found to be contaminated by As, Cu, Pb, Sb, Se and Zn as compared to the non-contaminated soil. The pH-dependent extraction behavior of various elements from the soils was measured in a wide pH range and categorized into three groups. Hydrochloric acid (HCl), H2SO4, H3PO4, HNO3, sodium citrate, sodium tartrate, disodium dihydrogen ethylenediaminetetraacetate and diethylenetriaminepentaacetic acid were evaluated as extractants for removing contaminants from the soils. Extraction behavior of the soil constituents was also studied. The efficiency of the extraction was evaluated by the Japanese content and leaching tests. The stabilization of Pb remaining in the soil after the extraction process was conducted by the addition of iron(III) and calcium chloride.

Synthesis of zeolite/nickel ferrite/sodium alginate bionanocomposite via a co-precipitation technique for efficient removal of water-soluble methylene blue dye.

PubMed

Bayat, Mahsa; Javanbakht, Vahid; Esmaili, Javad

2018-05-05

In this study, we sought to synthesize magnetic nanocomposite of zeolite/nickel ferrite through co-precipitation method and modify its surface by sodium alginate to enhance its methylene blue adsorption capacity and to prevent its oxidation. Nanocomposite characteristics were investigated by SEM, VSM, XRD and FTIR analyses. The results indicate that nanocomposite synthesis and modification has been completely successful. Adsorption thermodynamics, kinetics, and isotherms were examined and parameters were optimized by Minitab software using experimental design method, response surface methodology and Box-Behnken design. The highest capacity of methylene blue adsorption from the aqueous solution obtained at optimal pH of 5, the initial dye concentration of 10 mg/L and an adsorbent amount of 0.03 g was about 54.05 mg/g. Analyzing kinetic data of adsorption experiments confirmed that adsorption process complies with the pseudo-second-order kinetic model. Assessing equilibrium isotherm data at different temperatures showed that these data are in good agreement with Langmuir isotherm model. Copyright © 2018 Elsevier B.V. All rights reserved.

Treatment of winery wastewater by anodic oxidation using BDD electrode.

PubMed

Candia-Onfray, Christian; Espinoza, Nicole; Sabino da Silva, Evanimek B; Toledo-Neira, Carla; Espinoza, L Carolina; Santander, Rocío; García, Verónica; Salazar, Ricardo

2018-05-04

The effective removal of organics from winery wastewater was obtained in real residual effluents from the wine industry using anodic oxidation (AO). The effluent had an initial organic load of [COD] 0 of 3490 mg L -1 equal to [TOC] 0 of 1320 mg L -1 . In addition, more than 40 organic compounds were identified by means of GC-MS. Different density currents as well as the addition of electrolytes were tested during electrolysis. The results show the decay of [COD] t by 63.6% when no support electrolyte was added, whereas almost total mineralization and disinfection was reached after adding of 50 mM of sodium sulfate and sodium chloride and applying higher density currents. The presence of sulfate and chloride in large concentration favors the production of oxidants such as hydroxyl radicals and active chlorine species that react with organics in solution. Moreover, the addition of a supporting electrolyte to industrial wastewater increases conductivity, reduces cell potential and therefore, decreases the energy consumption of the AO process. Copyright © 2018 Elsevier Ltd. All rights reserved.

Treatment of simulated wastewater containing Reactive Red 195 by zero-valent iron/activated carbon combined with microwave discharge electrodeless lamp/sodium hypochlorite.

PubMed

Fu, Jie; Xu, Zhen; Li, Qing-Shan; Chen, Song; An, Shu-Qing; Zeng, Qing-Fu; Zhu, Hai-Liang

2010-01-01

A comparative study of treatment of simulated wastewater containing Reactive Red 195 using zero-valent iron/activated carbon (ZVI/AC), microwave discharge electrodeless lamp/sodium hypochlorite (MDEL/NaClO) and the combination of ZVI/AC-MDEL/NaClO was conducted. The preliminary results showed the two steps method of ZVI/AC-MDEL/NaClO had much higher degradation efficiency than both single steps. The final color removal percentage was nearly up to 100% and the chemical oxygen demand reduction percentage was up to approximately 82%. The effects of operational parameters, including initial pH value of simulated wastewater, ZVI/AC ratio and particle size of ZVI were also investigated. In addition, from the discussion of synergistic effect between ZVI/AC and MEDL/NaClO, we found that in the ZVI/AC-MEDL/NaClO process, ZVI/AC could break the azo bond firstly and then MEDL/NaClO degraded the aromatic amine products effectively. Reversing the order would reduce the degradation efficiency.

Enhanced decolorization of methyl orange in aqueous solution using iron-carbon micro-electrolysis activation of sodium persulfate.

PubMed

Li, Peng; Liu, Zhipeng; Wang, Xuegang; Guo, Yadan; Wang, Lizhang

2017-08-01

Reactivity of sodium persulfate (PS) in the decolorization of methyl orange (MO) in aqueous solution using an iron-carbon micro-electrolysis (ICE) method was investigated. The effects of sodium persulfate doses, pH, Fe-to-C mass ratios, initial MO concentration as well as the reaction temperature were comprehensively studied in batch experiments. The ICE-PS coupled process was more suitable for wide ranges of pH, initial MO concentration and reaction temperature, accompanied by the reduction of Fe compared ICE. The MO removal efficiency improved substantially by ICE-PS technique, 76.03% for ICE and 91.27% for ICE-PS at experimental conditions of pH 3.0, Fe-to-C mass ratio 3:1, PS addition 10 mM and initial MO concentration 0.61 mM. Furthermore, the biodegradability index (BI) dramatically increased from 0.26 to 0.65. The binary hydroxyl and sulfate radicals that non-selectively degrade MO to the derivatives with small molecules are ascribed to ICE-PS method as detected by the UV-vis spectra. The PS activation resource was Fe 2+ through the hydroxyl radical quenching reaction by the additive tert-butanol (TBA). This study provides an in-depth theoretical understanding of the development and wide commercial application of the ICE technology to refractory industrial dye wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

40 CFR 436.150 - Applicability; description of the sodium sulfate subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... sodium sulfate subcategory. 436.150 Section 436.150 Protection of Environment ENVIRONMENTAL PROTECTION... SOURCE CATEGORY Sodium Sulfate Subcategory § 436.150 Applicability; description of the sodium sulfate subcategory. The provisions of this subpart are applicable to the processing of sodium sulfate. Sodium sulfate...

40 CFR 436.150 - Applicability; description of the sodium sulfate subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... sodium sulfate subcategory. 436.150 Section 436.150 Protection of Environment ENVIRONMENTAL PROTECTION... Sodium Sulfate Subcategory § 436.150 Applicability; description of the sodium sulfate subcategory. The provisions of this subpart are applicable to the processing of sodium sulfate. Sodium sulfate obtained from...

40 CFR 436.150 - Applicability; description of the sodium sulfate subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... sodium sulfate subcategory. 436.150 Section 436.150 Protection of Environment ENVIRONMENTAL PROTECTION... SOURCE CATEGORY Sodium Sulfate Subcategory § 436.150 Applicability; description of the sodium sulfate subcategory. The provisions of this subpart are applicable to the processing of sodium sulfate. Sodium sulfate...

40 CFR 436.150 - Applicability; description of the sodium sulfate subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... sodium sulfate subcategory. 436.150 Section 436.150 Protection of Environment ENVIRONMENTAL PROTECTION... SOURCE CATEGORY Sodium Sulfate Subcategory § 436.150 Applicability; description of the sodium sulfate subcategory. The provisions of this subpart are applicable to the processing of sodium sulfate. Sodium sulfate...

40 CFR 436.150 - Applicability; description of the sodium sulfate subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... sodium sulfate subcategory. 436.150 Section 436.150 Protection of Environment ENVIRONMENTAL PROTECTION... Sodium Sulfate Subcategory § 436.150 Applicability; description of the sodium sulfate subcategory. The provisions of this subpart are applicable to the processing of sodium sulfate. Sodium sulfate obtained from...

Efficacy of disinfecting solutions in removing biofilms from polyvinyl chloride tracheostomy tubes.

PubMed

Silva, Rodrigo C; Carver, Ryan A; Ojano-Dirain, Carolyn P; Antonelli, Patrick J

2013-01-01

Bacterial biofilms are prevalent in pediatric tracheostomy tubes (TTs) and are not completely cleared by standard cleaning with gauze and household detergents. We aimed to examine the effectiveness of different disinfecting solutions to remove Staphylococcus aureus (SA) and Pseudomonas aerginosa (PA) biofilms from TTs. Prospective, controlled, in vitro microbiologic study. Uniform coupons obtained from polyvinyl chloride (PVC) pediatric TTs were briefly exposed to human plasma. The samples were incubated in growth media with either PA or SA for 7 days, and total bacterial growth was monitored by media turbidity. Five sets of 18 coupons each were exposed for 5 minutes to one of five different solutions: 2% aqueous chlorhexidine gluconate solution, 0.3% aqueous sodium hypochlorite, Polident denture cleanser, 3% hydrogen peroxide, or preservative-free phosphate-buffered saline (PBS) as a negative control. Biofilm presence was measured with bacterial counts, and surface integrity was assessed with scanning electron microscopy (SEM). All treatments significantly reduced mean SA counts (P = <.001). Sodium hypochlorite and chlorhexidine were more effective than peroxide and Polident. Chlorhexidine, sodium hypochlorite, and peroxide reduced PA counts (P = .001, .001, and .002, respectively), but Polident tabs had no significant effect. SEM revealed preserved TT surface integrity after exposure to all solutions. Disinfection with sodium hypochlorite or chlorhexidine solutions significantly reduces SA and PA biofilms on PVC TTs. Standard home care of reusable pediatric TTs may be improved by use of these readily available solutions. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

Removal of organic dyes by magnetic alginate beads.

PubMed

Rocher, Vincent; Siaugue, Jean-Michel; Cabuil, Valérie; Bee, Agnès

2008-02-01

This study deals with the development of a clean and safe process for water pollution remediation. We have synthesized a magnetic adsorbent in order to develop a solid-phase extraction process assisted by a magnetic field. To follow an 'ecoconception' approach, magnetic beads containing magnetic nanoparticles and activated carbon are prepared with a biopolymer extracted from algae, sodium alginate. The use of renewable bioresources of low cost and those disposable in large amount allows the development of a product with a low impact on the environment. The adsorption properties of activated carbon and magnetic properties of iron oxide nanoparticles are combined to produce an interesting magnetic composite. Synthesis and characterization of the magnetic beads have been reported. Their adsorption capacity was investigated by measuring the removal of two dyes (methylene blue and methyl orange) of different charges from aqueous solutions. The efficiency of the beads has been compared with that of non-encapsulated activated carbon. The effects of initial dye concentration, pH and calcium content of the beads have been studied. Adsorption kinetics experiments have been carried out and the data have been well fitted by a pseudo-second-order equation.

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

Josephson, Gary B.; Geeting, John GH; Bredt, Ofelia P.

Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Waste Treatment Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed, and operated as part of a plan to respond to issue M12, "Undemonstrated Leaching Processes." The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEPmore » also includes non-prototypic ancillary equipment to support the core processing. Two operating scenarios are currently being evaluated for the ultrafiltration process (UFP) and leaching operations. The first scenario has caustic leaching performed in the UFP-2 ultrafiltration feed vessels (i.e., vessel UFP-VSL-T02A in the PEP; and vessels UFP-VSL-00002A and B in the WTP PTF). The second scenario has caustic leaching conducted in the UFP-1 ultrafiltration feed preparation vessels (i.e., vessels UFP-VSL-T01A and B in the PEP; vessels UFP-VSL-00001A and B in the WTP PTF). In both scenarios, 19-M sodium hydroxide solution (NaOH, caustic) is added to the waste slurry in the vessels to leach solid aluminum compounds (e.g., gibbsite, boehmite). Caustic addition is followed by a heating step that uses direct injection of steam to accelerate the leach process. Following the caustic leach, the vessel contents are cooled using vessel cooling jackets and/or external heat exchangers. The main difference between the two scenarios is that for leaching in UFP-1, the 19-M NaOH is added to un-concentrated waste slurry (3-8 wt% solids), while for leaching in UFP-2, the slurry is concentrated to nominally 20 wt% solids using cross-flow ultrafiltration before the addition of caustic. In both scenarios, following the caustic leach, the slurry was then concentrated to 17 wt% and washed with inhibited water to remove NaOH and other soluble salts. Next, the slurry was oxidatively leached using sodium permanganate to solubilize chrome. The slurry was then washed to remove the dissolved chrome and concentrated.« less

Application of edible paraffin oil for cationic dye removal from water using emulsion liquid membrane.

PubMed

Zereshki, Sina; Daraei, Parisa; Shokri, Amin

2018-05-18

Using an emulsion liquid membrane based on edible oils is investigated for removing cationic dyes from aqueous solutions. There is a great potential for using edible oils in food industry extraction processes. The parameters affecting the stability of the emulsion and the extraction rate were studied. These parameters were the emulsification time, the stirring speed, the surfactant concentration, the internal phase concentration, the feed phase concentration, the volume ratio of internal phase to organic phase and the treat ratio. In order to stabilize the emulsion without using a carrier, edible paraffin oil and heptane are used at an 80:20 ratio. The optimum conditions for the extraction of methylene blue (MB), crystal violet and methyl violet (CV and MV) cationic dyes using edible paraffin oil as an environment friendly solvent are represented. A removal percentage of 95% was achieved for a mixture of dyes. The optimum concentration of sodium hydroxide in the internal phase, which results a stabile emulsion with a high stripping efficiency of 96%, was 0.04 M. An excellent membrane recovery was observed and the extraction of dyes did not decrease up to seven run cycles. Copyright © 2018 Elsevier B.V. All rights reserved.

The effects of non-ionic polymeric surfactants on the cleaning of biofouled hydrogel materials.

PubMed

Guan, Allan; Li, Zhenyu; Phillips, K Scott

2015-01-01

Block co-polymer surfactants have been used for cleaning hydrogel medical devices that contact the body (e.g., contact lenses) because of their biocompatibility. This work examined the relationship between concentration and detergency of two non-ionic polymeric surfactants (Pluronic F127 and Triton X-100) for cleaning protein soil, with anionic surfactants (sodium dodecyl sulfate and sodium laureth sulfate) as positive controls. Surface plasmon resonance was used to quantify removal of simulated tear soil from self-assembled monolayer surfaces, and a microplate format was used to study the removal of fluorescently labeled soil proteins from contact lenses. While detergency increased as a function of concentration for anionic surfactants, it decreased with concentration for the two polymeric surfactants. The fact that the protein detergency of some non-ionic polymeric surfactants did not increase with concentration above the critical micelle concentration could have implications for optimizing the tradeoff between detergency and biocompatibility.

Can nutrient status of four woody plant species be predicted using field spectrometry?

NASA Astrophysics Data System (ADS)

Ferwerda, Jelle G.; Skidmore, Andrew K.

This paper demonstrates the potential of hyperspectral remote sensing to predict the chemical composition (i.e., nitrogen, phosphorous, calcium, potassium, sodium, and magnesium) of three tree species (i.e., willow, mopane and olive) and one shrub species (i.e., heather). Reflectance spectra, derivative spectra and continuum-removed spectra were compared in terms of predictive power. Results showed that the best predictions for nitrogen, phosphorous, and magnesium occur when using derivative spectra, and the best predictions for sodium, potassium, and calcium occur when using continuum-removed data. To test whether a general model for multiple species is also valid for individual species, a bootstrapping routine was applied. Prediction accuracies for the individual species were lower then prediction accuracies obtained for the combined dataset for all except one element/species combination, indicating that indices with high prediction accuracies at the landscape scale are less appropriate to detect the chemical content of individual species.

Degradation of Penicillin G by heat activated persulfate in aqueous solution.

PubMed

Norzaee, Samira; Taghavi, Mahmoud; Djahed, Babak; Kord Mostafapour, Ferdos

2018-06-01

We used Heat Activated of Persulfate (HAP) to decompose Penicillin G (PEN G) in aqueous solution. The effect of pH (3-11), temperature (313-353 K), and initial concentration of Sodium Persulfate (SPS) (0.05-0.5 mM) on the decomposition level of PEN G were investigated. The residue of PEN G was determined by spectrophotometry at the wavelength of 290 nm. Also, the Chemical Oxygen Demand (COD) was measured in each experiment. The Total Organic Carbon (TOC) analysis was utilized for surveying the mineralization of PEN G. In addition, based on Arrhenius equation, the activation energy of PEN G decomposition was calculated. The results indicated that the maximum PEN G removal rate was obtained at pH 5 and by increasing the doses of SPS from 0.05 to 0.5 mM, the PEN G decomposition was enhanced. It was found that an increase in temperature is accompanied by an increase in removal efficiency of PEN G. The activation energy of the studied process was determined to be 94.8 kJ mol -1 , suggesting that a moderate activation energy is required for PEN G decomposition. The TOC measurements indicate that the HAP can efficiently mineralize PEN G. Besides, the presence of the scavengers significantly suppressed the HAP process to remove the PEN G. Overall, the results of this study demonstrate that using HAP process can be a suitable method for decomposing of PEN G in aqueous solutions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Separation and purification of γ-aminobutyric acid from fermentation broth by flocculation and chromatographic methodologies.

PubMed

Gao, Qiang; Duan, Qiang; Wang, Depei; Zhang, Yunze; Zheng, Chunyang

2013-02-27

To date, the multifunctional γ-aminobutyric acid (GABA) is mainly produced by microbial fermentation in industry. The purpose of this study was to find an effective method for separation and purification of 31.2 g/L initial GABA from the fermentation broth of Enterococcus raffinosus TCCC11660. To remove the impurities from fermentation broth, flocculation pretreatment using chitosan and sodium alginate was first implemented to facilitate subsequent filtration. Ultrafiltration followed two discontinuous diafiltration steps to effectively remove proteins and macromolecular pigments, and the resulting permeate was further decolored by DA201-CII resin at a high decoloration ratio and GABA recovery. Subsequently, ion exchange chromatography (IEC) with Amberlite 200C resin and gradient elution were applied for GABA separation from glutamate and arginine. Finally, GABA crystals of 99.1% purity were prepared via warm ethanol precipitation twice. Overall, our results reveal that the successive process including flocculation, filtration, ultrafiltration, decoloration, IEC, and crystallization is promising for scale-up GABA extraction from fermentation broth.

Removal of Cd (II) from synthetic wastewater by alginate-Ayous wood sawdust (Triplochiton scleroxylon) composite material.

PubMed

Njimou, Jacques Romain; Măicăneanu, Andrada; Indolean, Cerasella; Nanseu-Njiki, Charles Péguy; Ngameni, Emmanuel

2016-01-01

The biosorption characteristics of Cd (II) ions from synthetic wastewater using raw Ayous wood sawdust (Triplochiton scleroxylon), r-AS, immobilized by sodium alginate were investigated with respect to pH, biomass quantity, contact time, initial concentration of heavy metal, temperature and stirring rate. The experimental data fitted well with the Langmuir isotherm, suggesting that monolayer adsorption of the cadmium ions onto alginate-Ayous sawdust composite (a-ASC). The obtained monolayer adsorption capacity of a-ASC for Cd (II) was 6.21 mg/g. From the Dubinin-Radushkevich isotherm model, a 5.39 kJ/mol value for the mean free energy was calculated, indicating that Cd (II) biosorption could include an important physisorption stage. Thermodynamic calculations showed that the Cd (II) biosorption process was feasible, endothermic and spontaneous in nature under examined conditions. The results indicated that a-ASC could be an alternative material replacing more costly adsorbents used for the removal of heavy metals.

Short-term cross-sensitizion of need-free sugar intake by combining sodium depletion and hypertonic NaCl intake.

PubMed

Santos, Bruna M; de Andrade, Carina A F; Menani, José V; De Luca, Laurival A

2016-12-01

History of sodium depletion cross-sensitizes the effects of drugs of abuse. The objective of the present study was to find out if history of sodium depletion also cross-sensitizes a natural reward such as sugar intake in the rat. Sodium depletion was induced by furosemide combined with removal of ambient sodium for 24 h; it was repeated seven days later. The depletion was immediately followed by 0.3 M NaCl intake in a sodium appetite test (active sodium repletion). Seven days after the last depletion, hydrated and fed (need-free) sucrose-naïve animals were offered 10% sucrose in a first 2-h sucrose test. The sucrose test was repeated once a day in a series of five consecutive days. History of sodium depletion enhanced sucrose intake in the first and second tests; it had no effect from the third to fifth sucrose test. The effect on the initial sucrose intake tests disappeared if the rats did not ingest 0.3 M NaCl in the sodium appetite test. Prior experience with sucrose intake in need-free conditions had no effect on sodium appetite. History of intracellular dehydration transiently influenced sucrose intake in the first sucrose test. We found no evidence for thirst sensitization. We conclude that history of dehydration, particularly that resulting from sodium depletion, combined to active sodium repletion, produced short-term cross-sensitization of sucrose intake in sucrose-naïve rats. The results suggest that the cross-sensitization of sucrose intake related with acquisition of sugar as a novel nutrient rather than production of lasting effects on sugar rewarding properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

The calcium content of human erythrocytes

PubMed Central

Harrison, D. G.; Long, C.

1968-01-01

1. The calcium content of human erythrocytes, after removal of the buffy coat and washing free from plasma with isotonic sodium chloride, has been determined by atomic absorption spectrophotometry. The mean value found for normal subjects was 0·634 μg/ml. of packed erythrocytes (0·0158 μg-atom/ml.). The corresponding values for magnesium and zinc were 79·7 and 20·1 μg/ml., respectively. 2. The calcium is considered to be mostly and perhaps exclusively located in the erythrocyte membrane, since, after osmotic haemolysis, the same amount was found in the ghost cells as was present in the erythrocytes from which they were prepared. By contrast, magnesium and zinc, which are essentially intracellular, were lost to the extent of about 96 and 92%, respectively. 3. About 90% of the calcium was removed from erythrocytes by washing with isotonic sodium chloride containing 5 mM ethylenediaminetetraacetate (EDTA), or other complexing agents of high stability constant for calcium. A small fraction of the magnesium but none of the zinc was removed by this treatment. 4. Other complexing agents of lower stability constant removed somewhat less calcium from the erythrocytes. Citrate was totally ineffective. 5. The buffy coat had a high calcium content, but this could not be removed by washing with EDTA. 6. Calcium was also determined in trichloroacetic acid extracts of ghost cells after ashing and treatment with bis-(o-hydroxyphenylimino)-ethane and measuring the red complex spectrophotometrically. The values obtained confirmed the atomic absorption measurements. PMID:4972779

Sodium metasomatism along the Melones fault zone, Sierra Nevada foothills, California, USA

USGS Publications Warehouse

Albino, G.V.

1995-01-01

Albitite, locally aegirine- and riebeckite-bearing, formed as a result of sodium metasomatism of felsic dykes and argillites along the Melones Fault Zone near Jamestown, California. Pyrite, magnetite, hematite and titanite are common in small amounts in altered dykes. The dykes were originally plagioclase-hornblende porphyritic, and had major and trace element abundances typical of calc-alkaline rocks, whereas they now have Na2O contents as high as 11.40%. Mass balance calculations indicate that alteration involved addition of large amounts of sodium, and the removal of SiO2 and K2O. Textural preservation, combined with volume factors calculated from specific gravity and whole rock analytical data, indicate that Na-metasomatism was essentially isovolumetric. -from Author

Development of Systems for Delivery of Antiviral Drugs.

DTIC Science & Technology

1986-10-31

in an ice bath under a nitrogen atmosphere. Sodium dithionite (820 mg of Aldrich 85% technical grade; 4.0 mmol) was added; after 1 min a precipitate ...extracted with cold 0.5N perchloric acid (PCA) and the precipitated proteins were removed by centrifugation. The pH of the supernatnant was adjusted...four volumes of acetonitrile. The precipitated proteins were removed by centrifugation and the clear supernatant was evaporated to dryness under N2

Stability studies for titanium dioxide nanoparticles upon adsorption of Suwannee River humic and fulvic acids and natural organic matter.

PubMed

Erhayem, Mohamed; Sohn, Mary

2014-01-15

In many studies humic acid, fulvic acid, or natural organic matter is used interchangeably to model the effect of naturally derived organic matter on geochemical processes in the environment. In this study, the term NOOM (naturally occurring organic matter) is used to include both humic and fulvic acids as well as natural organic matter and compares the effect of NOOM type on NOOM removal onto nano-TiO2. In general, regardless of variations in solution chemistry, the order of the percentage of removal of NOOM onto nano-TiO2 was humic acid>natural organic matter>fulvic acid. The order of adsorption constant values of NOOM onto nano-TiO2 was also found to be humic acid>natural organic matter>fulvic acid under all conditions studied. The extent of NOOM removal by nano-TiO2 was enhanced in the presence of the divalent ions, magnesium and calcium, at pH7.8 when compared to the presence of the monovalent ions, sodium and potassium. Also, lower NOOM removal by nano-TiO2 in the presence of sodium salts of dihydrogen phosphate, bicarbonate and nitrate relative to chloride was observed and was likely due to the competition between polyatomic anions and NOOM adsorption onto the surface of nano-TiO2 indicating an anionic effect. Low concentrations of NOOM (10-20 mg L(-1)) destabilized nano-TiO2 in solution, however, the stability of nano-TiO2 increased as the amount of NOOM adsorbed onto nano-TiO2 increased at higher dissolved NOOM concentrations and significant stabilization was seen at 25 mg L(-1) NOOM. Thus, the three fractions of NOOM, humic and fulvic acids and natural organic matter and their concentrations were found to affect nano-TiO2 stability to different degrees although pH dependent trends in cation and anion effects had similar patterns. While the effects of adsorption of these three commonly used types of NOOM onto nanoparticles are similar, there are important differences that can be related to structural differences. © 2013.

Maintenance of Mouse Gustatory Terminal Field Organization Is Disrupted following Selective Removal of Peripheral Sodium Salt Taste Activity at Adulthood

PubMed Central

Sun, Chengsan

2017-01-01

Neural activity plays a critical role in the development of central circuits in sensory systems. However, the maintenance of these circuits at adulthood is usually not dependent on sensory-elicited neural activity. Recent work in the mouse gustatory system showed that selectively deleting the primary transduction channel for sodium taste, the epithelial sodium channel (ENaC), throughout development dramatically impacted the organization of the central terminal fields of three nerves that carry taste information to the nucleus of the solitary tract. More specifically, deleting ENaCs during development prevented the normal maturation of the fields. The present study was designed to extend these findings by testing the hypothesis that the loss of sodium taste activity impacts the maintenance of the normal adult terminal field organization in male and female mice. To do this, we used an inducible Cre-dependent genetic recombination strategy to delete ENaC function after terminal field maturation occurred. We found that removal of sodium taste neural activity at adulthood resulted in significant reorganization of mature gustatory afferent terminal fields in the nucleus of the solitary tract. Specifically, the chorda tympani and greater superficial petrosal nerve terminal fields were 1.4× and 1.6× larger than age-matched controls, respectively. By contrast, the glossopharyngeal nerve, which is not highly sensitive to sodium taste stimulation, did not undergo terminal field reorganization. These surprising results suggest that gustatory nerve terminal fields remain plastic well into adulthood, which likely impacts central coding of taste information and taste-related behaviors with altered taste experience. SIGNIFICANCE STATEMENT Neural activity plays a major role in the development of sensory circuits in the mammalian brain. However, the importance of sensory-driven activity in maintaining these circuits at adulthood, especially in subcortical structures, appears to be much less. Here, we tested whether the loss of sodium taste activity in adult mice impacts the maintenance of how taste nerves project to the first central relay. We found that specific loss of sodium-elicited taste activity at adulthood produced dramatic and selective reorganization of terminal fields in the brainstem. This demonstrates, for the first time, that taste-elicited activity is necessary for the normal maintenance of central gustatory circuits at adulthood and highlights a level of plasticity not seen in other sensory system subcortical circuits. PMID:28676575

Downregulation of surface sodium pumps by endocytosis during meiotic maturation of Xenopus laevis oocytes

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

Schmalzing, G.; Eckard, P.; Kroener, S.P.

1990-01-01

During meiotic maturation, plasma membranes of Xenopus laevis oocytes completely lose the capacity to transport Na and K and to bind ouabain. To explore whether the downregulation might be due to an internalization of the sodium pump molecules, the intracellular binding of ouabain was determined. Selective permeabilization of the plasma membrane of mature oocytes (eggs) by digitonin almost failed to disclose ouabain binding sites. However, when the eggs were additionally treated with 0.02% sodium dodecyl sulfate (SDS) to permeabilize inner membranes, all sodium pumps present before maturation were recovered. Phosphorylation by (gamma-32P)ATP combined with SDS-polyacrylamide gel electrophoresis (PAGE) and autoradiographymore » showed that sodium pumps were greatly reduced in isolated plasma membranes of eggs. According to sucrose gradient fractionation, maturation induced a shift of sodium pumps from the plasma membrane fraction to membranes of lower buoyant density with a protein composition different from that of the plasma membrane. Endocytosed sodium pumps identified on the sucrose gradient from (3H)ouabain bound to the cell surface before maturation could be phosphorylated with inorganic (32P)phosphate. The findings suggest that downregulation of sodium pumps during maturation is brought about by translocation of surface sodium pumps to an intracellular compartment, presumably endosomes. This contrasts the mechanism of downregulation of Na-dependent cotransport systems, the activities of which are reduced as a consequence of a maturation-induced depolarization of the membrane without a removal of the corresponding transporter from the plasma membrane.« less

Urinary Sodium and Potassium Excretion and Dietary Sources of Sodium in Maputo, Mozambique.

PubMed

Queiroz, Ana; Damasceno, Albertino; Jessen, Neusa; Novela, Célia; Moreira, Pedro; Lunet, Nuno; Padrão, Patrícia

2017-08-03

This study aimed to evaluate the urinary excretion of sodium and potassium, and to estimate the main food sources of sodium in Maputo dwellers. A cross-sectional evaluation of a sample of 100 hospital workers was conducted between October 2012 and May 2013. Sodium and potassium urinary excretion was assessed in a 24-h urine sample; creatinine excretion was used to exclude unlikely urine values. Food intake in the same period of urine collection was assessed using a 24-h dietary recall. The Food Processor Plus ® was used to estimate sodium intake corresponding to naturally occurring sodium and sodium added to processed foods (non-discretionary sodium). Salt added during culinary preparations (discretionary sodium) was computed as the difference between urinary sodium excretion and non-discretionary sodium. The mean (standard deviation) urinary sodium excretion was 4220 (1830) mg/day, and 92% of the participants were above the World Health Organization (WHO) recommendations. Discretionary sodium contributed 60.1% of total dietary sodium intake, followed by sodium from processed foods (29.0%) and naturally occurring sodium (10.9%). The mean (standard deviation) urinary potassium excretion was 1909 (778) mg/day, and 96% of the participants were below the WHO potassium intake recommendation. The mean (standard deviation) sodium to potassium molar ratio was 4.2 (2.4). Interventions to decrease sodium and increase potassium intake are needed in Mozambique.

Urinary Sodium and Potassium Excretion and Dietary Sources of Sodium in Maputo, Mozambique

PubMed Central

Queiroz, Ana; Damasceno, Albertino; Jessen, Neusa; Novela, Célia; Moreira, Pedro; Lunet, Nuno

2017-01-01

This study aimed to evaluate the urinary excretion of sodium and potassium, and to estimate the main food sources of sodium in Maputo dwellers. A cross-sectional evaluation of a sample of 100 hospital workers was conducted between October 2012 and May 2013. Sodium and potassium urinary excretion was assessed in a 24-h urine sample; creatinine excretion was used to exclude unlikely urine values. Food intake in the same period of urine collection was assessed using a 24-h dietary recall. The Food Processor Plus® was used to estimate sodium intake corresponding to naturally occurring sodium and sodium added to processed foods (non-discretionary sodium). Salt added during culinary preparations (discretionary sodium) was computed as the difference between urinary sodium excretion and non-discretionary sodium. The mean (standard deviation) urinary sodium excretion was 4220 (1830) mg/day, and 92% of the participants were above the World Health Organization (WHO) recommendations. Discretionary sodium contributed 60.1% of total dietary sodium intake, followed by sodium from processed foods (29.0%) and naturally occurring sodium (10.9%). The mean (standard deviation) urinary potassium excretion was 1909 (778) mg/day, and 96% of the participants were below the WHO potassium intake recommendation. The mean (standard deviation) sodium to potassium molar ratio was 4.2 (2.4). Interventions to decrease sodium and increase potassium intake are needed in Mozambique. PMID:28771193

The Sodium Content of Processed Foods in South Africa during the Introduction of Mandatory Sodium Limits

PubMed Central

Peters, Sanne A. E.; Dunford, Elizabeth; Ware, Lisa J.; Harris, Teresa; Walker, Adele; Wicks, Mariaan; van Zyl, Tertia; Swanepoel, Bianca; Charlton, Karen E.; Woodward, Mark; Webster, Jacqui; Neal, Bruce

2017-01-01

Background: In June 2016, the Republic of South Africa introduced legislation for mandatory limits for the upper sodium content permitted in a wide range of processed foods. We assessed the sodium levels of packaged foods in South Africa during the one-year period leading up to the mandatory implementation date of the legislation. Methods: Data on the nutritional composition of packaged foods was obtained from nutrition information panels on food labels through both in-store surveys and crowdsourcing by users of the HealthyFood Switch mobile phone app between June 2015 and August 2016. Summary sodium levels were calculated for 15 food categories, including the 13 categories covered by the sodium legislation. The percentage of foods that met the government’s 2016 sodium limits was also calculated. Results: 11,065 processed food items were included in the analyses; 1851 of these were subject to the sodium legislation. Overall, 67% of targeted foods had a sodium level at or below the legislated limit. Categories with the lowest percentage of foods that met legislated limits were bread (27%), potato crisps (41%), salt and vinegar flavoured snacks (42%), and raw processed sausages (45%). About half (49%) of targeted foods not meeting the legislated limits were less than 25% above the maximum sodium level. Conclusion: Sodium levels in two-thirds of foods covered by the South African sodium legislation were at or below the permitted upper levels at the mandatory implementation date of the legislation and many more were close to the limit. The South African food industry has an excellent opportunity to rapidly meet the legislated requirements. PMID:28425938

A practical approach to the degradation of polychlorinated biphenyls in transformer oil.

PubMed

Wu, Wenhai; Xu, Jie; Zhao, Hongmei; Zhang, Qing; Liao, Shijian

2005-08-01

A practical and efficient disposal method for hydrodechlorination of polychlorinated biphenyls (PCBs) in transformer oil is reported. Transformer oil containing PCBs was treated by nanometric sodium hydride (nano-NaH) and transition metal catalysts. High destruction and removal efficiency (89.8%) can be attained by nano-NaH alone under mild conditions. The process exhibits apparent characteristics of a first order reaction. The reductive ability of nano-NaH was enhanced by the addition of transition metal catalysts. In the presence of TiCl4, 99.9% PCBs was hydrodechlorinated. The complex reducing reagents, Ni(OAc)2+i-PrONa, show extra hydrodechlorinating activity for di-chlorinated biphenyls.

Flue gas desulfurization

DOEpatents

Im, Kwan H.; Ahluwalia, Rajesh K.

1985-01-01

A process and apparatus for removing sulfur oxide from combustion gas to form Na.sub.2 SO.sub.4 and for reducing the harmful effects of Na.sub.2 SO.sub.4 on auxiliary heat exchangers in which a sodium compound is injected into the hot combustion gas forming liquid Na.sub.2 SO.sub.4 in a gas-gas reaction and the resultant gas containing Na.sub.2 SO.sub.4 is cooled to below about 1150.degree. K. to form particles of Na.sub.2 SO.sub.4 prior to contact with at least one heat exchanger with the cooling being provided by the recycling of combustion gas from a cooled zone downstream from the introduction of the cooling gas.

Heavy metal removal from waste waters by ion flotation.

PubMed

Polat, H; Erdogan, D

2007-09-05

Flotation studies were carried out to investigate the removal of heavy metals such as copper (II), zinc (II), chromium (III) and silver (I) from waste waters. Various parameters such as pH, collector and frother concentrations and airflow rate were tested to determine the optimum flotation conditions. Sodium dodecyl sulfate and hexadecyltrimethyl ammonium bromide were used as collectors. Ethanol and methyl isobutyl carbinol (MIBC) were used as frothers. Metal removal reached about 74% under optimum conditions at low pH. At basic pH it became as high as 90%, probably due to the contribution from the flotation of metal precipitates.

Advantages of using microbial technology over traditional chemical technology in removal of black crusts from stone surfaces of historical monuments.

PubMed

Cappitelli, Francesca; Toniolo, Lucia; Sansonetti, Antonio; Gulotta, Davide; Ranalli, Giancarlo; Zanardini, Elisabetta; Sorlini, Claudia

2007-09-01

This study compares two cleaning methods, one involving an ammonium carbonate-EDTA mixture and the other involving the sulfate-reducing bacterium Desulfovibrio vulgaris subsp. vulgaris ATCC 29579, for the removal of black crust (containing gypsum) on marble of the Milan Cathedral (Italy). In contrast to the chemical cleaning method, the biological procedure resulted in more homogeneous removal of the surface deposits and preserved the patina noble under the black crust. Whereas both of the treatments converted gypsum to calcite, allowing consolidation, the chemical treatment also formed undesirable sodium sulfate.

Advantages of Using Microbial Technology over Traditional Chemical Technology in Removal of Black Crusts from Stone Surfaces of Historical Monuments▿

PubMed Central

Cappitelli, Francesca; Toniolo, Lucia; Sansonetti, Antonio; Gulotta, Davide; Ranalli, Giancarlo; Zanardini, Elisabetta; Sorlini, Claudia

2007-01-01

This study compares two cleaning methods, one involving an ammonium carbonate-EDTA mixture and the other involving the sulfate-reducing bacterium Desulfovibrio vulgaris subsp. vulgaris ATCC 29579, for the removal of black crust (containing gypsum) on marble of the Milan Cathedral (Italy). In contrast to the chemical cleaning method, the biological procedure resulted in more homogeneous removal of the surface deposits and preserved the patina noble under the black crust. Whereas both of the treatments converted gypsum to calcite, allowing consolidation, the chemical treatment also formed undesirable sodium sulfate. PMID:17601804

Performance evaluation of household water treatment systems used in Kerman for removal of cations and anions from drinking water

NASA Astrophysics Data System (ADS)

Malakootian, Mohammad; Amirmahani, Najmeh; Yazdanpanah, Ghazal; Nasiri, Alireza; Asadipour, Ali; Ebrahimi, Ahmad; Darvish Moghaddam, Sodaif

2017-12-01

Increased awareness in society of the consequences of contaminants in drinking water has created a demand for household water treatment systems, which provide higher quality water, to spread. The aim of this study was to evaluate the performance of household water treatment systems used in Kerman for the removal of cations and anions. Various brands of home water treatment devices commonly used in Kerman were selected, with one device chosen from each brand for study. In cases in which the devices were used extensively, samples were selected with filters that had been changed in proper time, based on the device's operational instructions. The samples were selected from homes in the center and four geographical directions of Kerman. Then, sampling was conducted in three stages of input and output water of each device. For each of the samples, parameters were measured, such as chloride, sulfate, bicarbonate, calcium, magnesium, hardness, sodium, nitrate and nitrite (mg/L), temperature (°C), and pH. The average removal efficiency of different parameters by 14 brands in Kerman, which include chloride ions, sulfate, bicarbonate, calcium, magnesium, sodium, nitrites, nitrates, and total hardness, was obtained at 68.48, 85, 67, 61.21, 78.97, 80.24, 32.59, 66.83, and 69.38%, respectively. The amount of sulfate, bicarbonate, chloride, calcium, magnesium, hardness, sodium, and nitrate in the output water of household water treatment systems was less than the input water of these devices, but nitrite concentration in the output of some devices was more than the input water and showed a significant difference ( p > 0.05).