Results Of Routine Strip Effluent Hold Tank, Decontaminated Salt Solution Hold Tank, Caustic Wash Tank And Caustic Storage Tank Samples From Modular Caustic-Side Solvent Extraction Unit During Macrobatch 6 Operations

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

Peters, T. B.

Strip Effluent Hold Tank (SEHT), Decontaminated Salt Solution Hold Tank (DSSHT), Caustic Wash Tank (CWT) and Caustic Storage Tank (CST) samples from the Interim Salt Disposition Project (ISDP) Salt Batch (“Macrobatch”) 6 have been analyzed for 238Pu, 90Sr, 137Cs, and by Inductively Coupled Plasma Emission Spectroscopy (ICPES). The Pu, Sr, and Cs results from the current Macrobatch 6 samples are similar to those from comparable samples in previous Macrobatch 5. In addition the SEHT and DSSHT heel samples (i.e. ‘preliminary’) have been analyzed and reported to meet NGS Demonstration Plan requirements. From a bulk chemical point of view, the ICPESmore » results do not vary considerably between this and the previous samples. The titanium results in the DSSHT samples continue to indicate the presence of Ti, when the feed material does not have detectable levels. This most likely indicates that leaching of Ti from MST has increased in ARP at the higher free hydroxide concentrations in the current feed.« less

LEACHING OF TITANIUM FROM MONOSODIUM TITANATE AND MODIFIED MST

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

Taylor-Pashow, K.; Fondeur, F.; Fink, S.

2012-08-01

Analysis of a fouled coalescer and pre-filters from Actinide Removal Process/Modular Caustic Side Solvent Extraction Unit (ARP/MCU) operations showed evidence of Ti containing solids. Based on these results a series of tests were planned to examine the extent of Ti leaching from monosodium titanate (MST) and modified monosodium titanate (mMST) in various solutions. The solutions tested included a series of salt solutions with varying free hydroxide concentrations, two sodium hydroxide concentrations, 9 wt % and 15 wt %, nitric and oxalic acid solutions. Overall, the amount of Ti leached from the MST and mMST was much greater in the acidmore » solutions compared to the sodium hydroxide or salt solutions, which is consistent with the expected trend. The leaching data also showed that increasing hydroxide concentration, whether pure NaOH solution used for filter cleaning in ARP or the waste salt solution, increased the amount of Ti leached from both the MST and mMST. For the respective nominal contact times with the MST solids - for filter cleaning or the normal filter operation, the dissolved Ti concentrations are comparable suggesting either cause may contribute to the increased Ti fouling on the MCU coalescers. Tests showed that Ti containing solids could be precipitated from solution after the addition of scrub acid and a decrease in temperature similar to expected in MCU operations. FTIR analysis of these solids showed some similarity to the solids observed on the fouled coalescer and pre-filters. Although only a cursory study, this information suggests that the practice of increasing free hydroxide in feed solutions to MCU as a mitigation to aluminosilicate formation may be offset by the impact of formation of Ti solids in the overall process. Additional consideration of this finding from MCU and SWPF operation is warranted.« less

CHARACTERIZATION OF ACTINIDES IN SIMULATED ALKALINE TANK WASTE SLUDGES AND LEACHATES

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

Nash, Kenneth L.

In this project, both the fundamental chemistry of actinides in alkaline solutions (relevant to those present in Hanford-style waste storage tanks), and their dissolution from sludge simulants (and interactions with supernatants) have been investigated under representative sludge leaching procedures. The leaching protocols were designed to go beyond conventional alkaline sludge leaching limits, including the application of acidic leachants, oxidants and complexing agents. The simulant leaching studies confirm in most cases the basic premise that actinides will remain in the sludge during leaching with 2-3 M NaOH caustic leach solutions. However, they also confirm significant chances for increased mobility of actinidesmore » under oxidative leaching conditions. Thermodynamic data generated improves the general level of experiemental information available to predict actinide speciation in leach solutions. Additional information indicates that improved Al removal can be achieved with even dilute acid leaching and that acidic Al(NO3)3 solutions can be decontaminated of co-mobilized actinides using conventional separations methods. Both complexing agents and acidic leaching solutions have significant potential to improve the effectiveness of conventional alkaline leaching protocols. The prime objective of this program was to provide adequate insight into actinide behavior under these conditions to enable prudent decision making as tank waste treatment protocols develop.« less

Results Of Routine Strip Effluent Hold Tank, Decontaminated Salt Solution Hold Tank, Caustic Wash Tank And Caustic Storage Tank Samples From Modular Caustic-Side Solvent Extraction Unit During Macrobatch 6 Operations

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

Peters, T. B.

Strip Effluent Hold Tank (SEHT), Decontaminated Salt Solution Hold Tank (DSSHT), Caustic Wash Tank (CWT) and Caustic Storage Tank (CST) samples from several of the ''microbatches'' of Integrated Salt Disposition Project (ISDP) Salt Batch (''Macrobatch'') 6 have been analyzed for {sup 238}Pu, {sup 90}Sr, {sup 137}Cs, and by Inductively Coupled Plasma Emission Spectroscopy (ICPES). The results from the current microbatch samples are similar to those from comparable samples in Macrobatch 5. From a bulk chemical point of view, the ICPES results do not vary considerably between this and the previous macrobatch. The titanium results in the DSSHT samples continue tomore » indicate the presence of Ti, when the feed material does not have detectable levels. This most likely indicates that leaching of Ti from MST in ARP continues to occur. Both the CST and CWT samples indicate that the target Free OH value of 0.03 has been surpassed. While at this time there is no indication that this has caused an operational problem, the CST should be adjusted into specification. The {sup 137}Cs results from the SRNL as well as F/H lab data indicate a potential decline in cesium decontamination factor. Further samples will be carefully monitored to investigate this.« less

Effect of Antifoam Agent on Oxidative Leaching of Hanford Tank Sludge Simulants

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

Rapko, Brian M.; Jones, Susan A.; Lumetta, Gregg J.

2010-02-26

Oxidative leaching of simulant tank waste containing an antifoam agent (AFA) to reduce the chromium content of the sludge was tested using permanganate as the oxidant in 0.25 M NaOH solutions. AFA is added to the waste treatment process to prevent foaming. The AFA, Dow Corning Q2-3183A, is a surface-active polymer that consists of polypropylene glycol, polydimethylsiloxane, octylphenoxy polyethoxy ethanol, treated silica, and polyether polyol. Some of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) waste slurries contain high concentrations of undissolved solids that would exhibit undesirable behavior without AFA addition. These tests were conducted to determine the effectmore » of the AFA on oxidative leaching of Cr(III) in waste by permanganate. It has not previously been determined what effect AFA has on the permanganate reaction. This study was conducted to determine the effect AFA has on the oxidation of the chromium, plus plutonium and other criticality-related elements, specifically Fe, Ni and Mn. During the oxidative leaching process, Mn is added as liquid permanganate solution and is converted to an insoluble solid that precipitates as MnO2 and becomes part of the solid waste. Caustic leaching was performed followed by an oxidative leach at either 25°C or 45°C. Samples of the leachate and solids were collected at each step of the process. Initially, Battelle-Pacific Northwest Division (PNWD) was contracted by Bechtel National, Inc. to perform these further scoping studies on oxidative alkaline leaching. The data obtained from the testing will be used by the WTP operations to develop procedures for permanganate dosing of Hanford tank sludge solids during oxidative leaching. Work was initially conducted under contract number 24590-101-TSA-W000-00004. In February 2007, the contract mechanism was switched to Pacific Northwest National Laboratory (PNNL) operating Contract DE-AC05-76RL01830. In summary, this report describes work focused on determining the effect of AFA on chromium oxidation by permanganate with Hanford sludge simulant.« less

ATLAS 60’ Fording Study

DTIC Science & Technology

1992-03-03

crack. Carbon steel stress cracks in the presence of sodium hydroxide (" caustic embrittlement"), whereas austenitic stainless steels stress crack in...transmission life. - Outboard planetary axle design reduces stresses on differential, drive shafts and axle shaft U-joints. . Enclosed oil disc brakes on... Stress Corrosion Crevice Pitting Erosion Corrosion Uniform Corrosion Intergranular Selective Leaching Page 19 Caterpflar Inc. ATLAS Fording Study Q The

Alkali activated solidification/stabilisation of air pollution control residues and co-fired pulverised fuel ash.

PubMed

Shirley, Robin; Black, Leon

2011-10-30

This paper examines the potential treatment by solidification/stabilisation (S/S) of air pollution control (APC) residues using only waste materials otherwise bound for disposal, namely a pulverised fuel ash (PFA) from a co-fired power station and a waste caustic solution. The use of waste materials to stabilise hazardous wastes in order to meet waste acceptance criteria (WAC) would offer an economical and efficient method for reducing the environmental impact of the hazardous waste. The potential is examined against leach limits for chlorides, sulphates and total dissolved solids, and compressive strength performance described in the WAC for stable non-reactive (SNR) hazardous waste landfill cells in England and Wales. The work demonstrates some potential for the treatment, including suitable compressive strengths to meet regulatory limits. Monolithic leach results showed good encapsulation compared to previous work using a more traditional cement binder. However, consistent with previous work, SNR WAC for chlorides was not met, suggesting the need for a washing stage. The potential problems of using a non-EN450 PFA for S/S applications were also highlighted, as well as experimental results which demonstrate the effect of ionic interactions on the mobility of phases during regulatory leach testing. Copyright © 2011 Elsevier B.V. All rights reserved.

Electrochemical characteristics of needle coke refined by molten caustic leaching as an anode material for a lithium-ion battery

NASA Astrophysics Data System (ADS)

Kang, Hyeong-Gon; Park, Jong-Kwang; Han, Byoung-Sung; Lee, Haeseong

Needle coke, the remaining material after refining petroleum, is used as an anode of a lithium-ion secondary battery. Sulfur is separated from the needle coke to below 0.1 wt.% using the molten caustic leaching (MCL) method developed at the Korea Institute of Energy Research. The needle coke with high-purity is carbonized at various temperatures, namely 0, 500, 700 and 900 °C. The coke treated at 700 °C gives a first and second discharge capacity of more than 560 and 460 mAh g -1, respectively, between 0 and 2.0 V. By contrast, the first and second discharge capacity of untreated coke is over 420 and 340 mAh g -1, respectively, between 0.05 and 2.0 V.The first discharge capacity of 560 mAh g -1 is beyond the theoretical maximum capacity of 372 mAh g -1 for LiC 6. Though the cycle efficiency is not consistent, the needle coke heat-treated at 700 °C persistently maintains an efficiency of over 90% until the 50th cycle, except on the first cycle. This study demonstrates that the needle coke with high-purity could be a good candidate for an anode material in fabricating high-capacity lithium-ion secondary batteries.

Characterization of solids deposited on the modular caustic-side solvent extraction unit (MCU) coalescer media removed in May and October 2014

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

Fondeur, F. F.

During routine maintenance, the coalescers utilized in the Modular Caustic-Side Solvent Extraction Unit (MCU) processing of Salt Batch 6 and a portion of Salt Batch 7 were sampled and submitted to the Savannah River National Laboratory (SRNL) for characterization, for the purpose of identifying solid phase constituents that may be accumulating in these coalescers. Specifically, two samples were received and characterized: A decontaminated salt solution (DSS) coalescer sample and a strip effluent (SE) coalescer sample. Aliquots of the samples were analyzed by XRD, Fourier Transform Infrared (FTIR) Spectroscopy, SEM, and EDS. Other aliquots of the samples were leached in acidmore » solution, and the leachates were analyzed by ICP-AES. In addition, modeling was performed to provide a basis for comparison of the analytical results.« less

Results Of Routine Strip Effluent Hold Tank, Decontaminated Salt Solution Hold Tank, And Caustic Wash Tank Samples From Modular Caustic-Side Solvent Extraction Unit During Macrobatch 4 Operations

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

Peters, T. B.; Fink, S. D.

Strip Effluent Hold Tank (SEHT), Decontaminated Salt Solution Hold Tank (DSSHT), and Caustic Wash Tank (CWT) samples from several of the ?microbatches? of Integrated Salt Disposition Project (ISDP) Salt Batch (?Macrobatch?) 4 have been analyzed for {sup 238}Pu, {sup 90}Sr, {sup 137}Cs, and by inductively-coupled plasma emission spectroscopy (ICPES). Furthermore, samples from the CWT have been analyzed by a variety of methods to investigate a decline in the decontamination factor (DF) of the cesium observed at MCU. The results indicate good decontamination performance within process design expectations. While the data set is sparse, the results of this set and themore » previous set of results for Macrobatch 3 samples indicate generally consistent operations. There is no indication of a disruption in plutonium and strontium removal. The average cesium DF and concentration factor (CF) for samples obtained from Macrobatch 4 are slightly lower than for Macrobatch 3, but still well within operating parameters. The DSSHT samples show continued presence of titanium, likely from leaching of the monosodium titanate in Actinide Removal Process (ARP).« less

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

Test Results for Caustic Demand Measurements on Tank 241-AX-101 and Tank 241-AX-103 Archive Samples

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

Doll, Stephanie R.; Bolling, Stacie D.

Caustic demand testing is used to determine the necessary amount of caustic required to neutralize species present in the Hanford tank waste and obtain a target molarity of free hydroxide for tank corrosion control. The presence and quantity of hydroxide-consuming analytes are just as important in determining the caustic demand as is the amount of free hydroxide present. No single data point can accurately predict whether a satisfactory hydroxide level is being met, as it is dependent on multiple factors (e.g., free hydroxide, buffers, amphoteric metal hydroxides, bicarbonate, etc.). This enclosure contains the caustic demand, scanning electron microscopy (SEM), polarizedmore » light microscopy (PLM), and X-ray diffraction (XRD) analysis for the tank 241-AX-101 (AX-101) and 241-AX-103 (AX-103) samples. The work was completed to fulfill a customer request outlined in the test plan, WRPS-1505529, “Test Plan and Procedure for Caustic Demand Testing on Tank 241-AX-101 and Tank 241-AX-103 Archive Samples.” The work results will provide a baseline to support planned retrieval of AX-101 and AX-103.« less

The wire optical test: a thorough analytical study in and out of caustic surface, and advantages of a dynamical adaptation

NASA Astrophysics Data System (ADS)

Alejandro Juárez-Reyes, Salvador; Sosa-Sánchez, Citlalli Teresa; Silva-Ortigoza, Gilberto; de Jesús Cabrera-Rosas, Omar; Espíndola-Ramos, Ernesto; Ortega-Vidals, Paula

2018-03-01

Among the best known non-interferometric optical tests are the wire test, the Foucault test and Ronchi test with a low frequency grating. Since the wire test is the seed to understand the other ones, the aim of the present work is to do a thorough study of this test for a lens with symmetry of revolution and to do this study for any configuration of the object and detection planes where both planes could intersect: two, one or no branches of the caustic region (including the marginal and paraxial foci). To this end, we calculated the vectorial representation for the caustic region, and we found the analytical expression for the pattern; we report that the analytical pattern explicitly depends on the magnitude of a branch of the caustic. With the analytical pattern we computed a set of simulations of a dynamical adaptation of the optical wire test. From those simulations, we have done a thorough analysis of the topological structure of the pattern; so we explain how the multiple image formation process and the image collapse process take place for each configuration, in particular, when both the wire and the detection planes are placed inside the caustic region, which has not been studied before. For the first time, we remark that not only the intersections of the object and detection planes with the caustic are important in the change of pattern topology; but also the projection of the intersection between the caustic and the object plane mapped onto the detection plane; and the virtual projection of the intersection between the caustic and the detection plane mapped onto the object plane. We present that for the new configurations of the optical system, the wire image is curves of the Tschirnhausen’s cubic, the piriform and the deformed eight-curve types.

Process for converting sodium nitrate-containing, caustic liquid radioactive wastes to solid insoluble products

DOEpatents

Barney, Gary S.; Brownell, Lloyd E.

1977-01-01

A method for converting sodium nitrate-containing, caustic, radioactive wastes to a solid, relatively insoluble, thermally stable form is provided and comprises the steps of reacting powdered aluminum silicate clay, e.g., kaolin, bentonite, dickite, halloysite, pyrophyllite, etc., with the sodium nitrate-containing radioactive wastes which have a caustic concentration of about 3 to 7 M at a temperature of 30.degree. C to 100.degree. C to thereby entrap the dissolved radioactive salts in the aluminosilicate matrix. In one embodiment the sodium nitrate-containing, caustic, radioactive liquid waste, such as neutralized Purex-type waste, or salts or oxide produced by evaporation or calcination of these liquid wastes (e.g., anhydrous salt cake) is converted at a temperature within the range of 30.degree. C to 100.degree. C to the solid mineral form-cancrinite having an approximate chemical formula 2(NaAlSiO.sub.4) .sup.. xSalt.sup.. y H.sub.2 O with x = 0.52 and y = 0.68 when the entrapped salt is NaNO.sub.3. In another embodiment the sodium nitrate-containing, caustic, radioactive liquid is reacted with the powdered aluminum silicate clay at a temperature within the range of 30.degree. C to 100.degree. C, the resulting reaction product is air dried eitheras loose powder or molded shapes (e.g., bricks) and then fired at a temperature of at least 600.degree. C to form the solid mineral form-nepheline which has the approximate chemical formula of NaAlSiO.sub.4. The leach rate of the entrapped radioactive salts with distilled water is reduced essentially to that of the aluminosilicate lattice which is very low, e.g., in the range of 10.sup.-.sup.2 to 10.sup.-.sup.4 g/cm.sup.2 -- day for cancrinite and 10.sup.-.sup.3 to 10.sup.-.sup.5 g/cm.sup.2 -- day for nepheline.

Caustic stress corrosion tests for the LLTR

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

Indig, M.E.

1976-05-01

A series of tests have been performed in order to determine the effects of the caustic resulting from the Na/H/sub 2/O reaction on the materials used in the LLTR-MSG series of testing. Stainless steel, 2 /sup 1///sub 4/ Cr--1 Mo and carbon steel have been evaluated. Stress corrosion cracking susceptibility and general corrosion are reported. Over the range of temperature, caustic concentration and heating rate tested the stainless steel stressed to 90% of yield or above suffered cracking. Whereas, the 2-/sup 1///sub 4/ Cr--1 Mo and carbon steel were not cracked.

Biogenic catalysis in sulphide minerals' weathering processes and acid mine drainage genesis.

PubMed

Kušnierová, Mária; Praščáková, Mária; Nowak, Anna K; Gorazda, Katarzyna; Wzorek, Zbigniew

2014-01-01

Bioleaching and biogenesis are the main outputs from a large group of environmental processes participating in the natural material cycle, used in raw materials processing. Bio-oxidation reactions are the main basis for bioleaching procedures, often participating in parallel leaching processes. During the leaching processes of polycomponent sulphide substrates, the factor of process selection also plays an important role, being in direct relation to the electric properties and galvanic effect occurring between the individual components of the leaching substrate. This work gives a summary of the results of a research focused on the possibilities of using biotechnological procedures for treatment of Slovak sulphide ores. The object of the research is extraction of valuable metals, undesirable admixtures and degradation of crystal lattice of sulphides for subsequent chemical leaching processing of precious metals. The results of experiments on the existence of biogenic processes in situ on waste dumps from exploitation containing residual sulphides are also presented. The processes result in acid mine drainage water generation. These waters are strongly mineralised (over 48 g/L) and of low pH; that is why they are very caustic. The arsenic content (2.558 mg/L) in outflowing waters from old mines is high and over the limits set by the law.

Dezincing Technology

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

Dudek, F.J.; Daniels, E.J.; Morgan, W.A.

1997-08-01

Half of the steel produced in the US is derived from scrap. With zinc-coated prompt scrap increasing fivefold since 1980, steel-makers are feeling the effect of increased contaminant loads on their operations. The greatest concern is the cost of treatment before disposal of waste dusts and water that arise from remelting zinc-coated scrap. An economic process is needed to strip and recover the zinc from scrap to provide a low residual scrap for steel- and iron-making. Metal Recovery Technologies, Inc., with the assistance of Argonne National Laboratory, have been developing a caustic leach dezincing process for upgrading galvanized stamping plantmore » scrap into clean scrap with recovery of the zinc. With further development the technology could also process galvanized scrap from obsolete automobiles. This paper will review: (1) the status of recent pilot plant operations and plans for a commercial demonstration facility with a dezincing capacity of up to 250,000 tons/year, (2) the economics of caustic dezincing, and (3) benefits of decreased cost of environmental compliance, raw material savings, and improved operations with use of dezinced scrap.« less

Flight test measurements and analysis of sonic boom phenomena near the shock wave extremity

NASA Technical Reports Server (NTRS)

Haglund, G. T.; Kane, E. J.

1973-01-01

The sonic boom flight test program conducted at Jackass Flats, Nevada, during the summer and fall of 1970 consisted of 121 sonic-boom-generating flights over the 1500 ft instrumented BREN tower. This test program was designed to provide information on several aspects of sonic boom, including caustics produced by longitudinal accelerations, caustics produced by steady flight near the threshold Mach number, sonic boom characteristics near lateral cutoff, and the vertical extent of shock waves attached to near-sonic airplanes. The measured test data, except for the near-sonic flight data, were analyzed in detail to determine sonic boom characteristics for these flight conditions and to determine the accuracy and the range of validity of linear sonic boom theory. The caustic phenomena observed during the threshold Mach number flights and during the transonic acceleration flights are documented and analyzed in detail. The theory of geometric acoustics is shown to be capable of predicting shock wave-ground intersections, and current methods for calculating sonic boom pressure signature away from caustics are shown to be reasonably accurate.

Optical method of caustics applied in viscoelastic fracture analysis

NASA Astrophysics Data System (ADS)

Gao, Guiyun; Li, Zheng; Xu, Jie

2011-05-01

The optical method of caustics is developed here to study the fracture of viscoelastic materials. By adopting a distribution of viscoelastic stress fields near the crack tip, the method of caustics is used to determine the viscoelastic fracture parameters from the caustic patterns near the crack tip. Two viscoelastic materials are studied. These are PMMA and ternary composites of HDPE/POE-g-MA/CaCO 3. The transmitted and reflective methods of caustics are performed separately to investigate viscoelastic fracture behaviors. The stress intensity factors (SIFs) versus time is determined by a series of shadow spot patterns combined with viscoelastic parameters evaluated by creep tests. In order to understand the viscoelastic fracture mechanisms of HDPE/POE-g-MA/CaCO 3 composites, their fracture surfaces are observed by a Scanning Electron Microscope (SEM). The results indicate that the method of caustics can be used to characterize the fracture behaviors of viscoelastic materials and further to optimize the design of polymer composites.

Archeological Survey and Testing Along Boone Creek, Louisiana Army Ammunition Plant, Webster Parish, Louisiana

DTIC Science & Technology

1989-01-01

ducks, partridges, cranes , quail, snakes, and fish. 8 CHAPTER 2: ENVIRONMENTAL SETTING Climate The modern climate of the project area is classified as... caustic materials. Large openings in their sides were cut by oil field workers, who then added water to the dry caustic material to make a caustic ...whiffletree hook and a harness ring were recovered, indicating that horses were used here. No automotive artifacts were recovered. This again reinforces the

Testing the Caustic Ring Dark Matter Halo Model Against Observations in the Milky Way

NASA Astrophysics Data System (ADS)

Dumas, Julie; Newberg, Heidi Jo; Niedzielski, Bethany; Susser, Adam; Thompson, Jeffery M.; Weiss, Jake; Lewis, Kim M.

2016-06-01

One prediction of axion dark matter models is they can form Bose-Einstein condensates and rigid caustic rings as a halo collapses in the non-linear regime. In this thesis, we undertake the first study of a caustic ring model for the Milky Way halo (Duffy & Sikivie 2008), paying particular attention to observational consequences. We first present the formalism for calculating the gravitational acceleration of a caustic ring halo. The caustic ring dark matter theory reproduces a roughly logarithmic halo, with large perturbations near the rings. We show that this halo can reasonably match the known Galactic rotation curve. We are not able to confirm or rule out an association between the positions of the caustic rings and oscillations in the observed rotation curve, due to insufficient rotation curve data. We explore the effects of dark matter caustic rings on dwarf galaxy tidal disruption with N-body simulations. Simulations of the Sagittarius (Sgr) dwarf galaxy in a caustic ring halo potential, with disk and bulge parameters that are tuned to match the Galactic rotation curve, match observations of the Sgr trailing tidal tails as far as 90 kpc from the Galactic center. Like the Navarro-Frenk-White (NFW) halo, they are, however, unable to match the leading tidal tail. None of the caustic, NFW, or triaxial logarithmic halos are able to simultaneously match observations of the leading and trailing arms of the Sagittarius stream. We further show that simulations of dwarf galaxies that move through caustic rings are qualitatively similar to those moving in a logarithmic halo. This research was funded by NSF grant AST 10-09670, the NASA-NY Space Grant, and the American Fellowship from AAUW.

21 CFR 1230.35 - Hearings.

Code of Federal Regulations, 2013 CFR

2013-04-01

... POISON ACT Administrative Procedures § 1230.35 Hearings. Whenever it appears from the inspection, analysis, or test of any container that the provisions of section 3 or 6 of the Federal Caustic Poison Act... prosecution as a violation of the Federal Caustic Poison Act. ...

21 CFR 1230.35 - Hearings.

Code of Federal Regulations, 2012 CFR

2012-04-01

... POISON ACT Administrative Procedures § 1230.35 Hearings. Whenever it appears from the inspection, analysis, or test of any container that the provisions of section 3 or 6 of the Federal Caustic Poison Act... prosecution as a violation of the Federal Caustic Poison Act. ...

21 CFR 1230.35 - Hearings.

Code of Federal Regulations, 2010 CFR

2010-04-01

... POISON ACT Administrative Procedures § 1230.35 Hearings. Whenever it appears from the inspection, analysis, or test of any container that the provisions of section 3 or 6 of the Federal Caustic Poison Act... prosecution as a violation of the Federal Caustic Poison Act. ...

Causticizing for Black Liquor Gasifiers

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

Scott Sinquefeld; James Cantrell; Xiaoyan Zeng

2009-01-07

The cost-benefit outlook of black liquor gasification (BLG) could be greatly improved if the smelt causticization step could be achieved in situ during the gasification step. Or, at a minimum, the increase in causticizing load associated with BLG could be mitigated. A number of chemistries have been proven successful during black liquor combustion. In this project, three in situ causticizing processes (titanate, manganate, and borate) were evaluated under conditions suitable for high temperature entrained flow BLG, and low temperature steam reforming of black liquor. The evaluation included both thermodynamic modeling and lab experimentation. Titanate and manganate were tested for completemore » direct causticizing (to thus eliminate the lime cycle), and borates were evaluated for partial causticizing (to mitigate the load increase associated with BLG). Criteria included high carbonate conversion, corresponding hydroxide recovery upon hydrolysis, non process element (NPE) removal, and economics. Of the six cases (three chemistries at two BLG conditions), only two were found to be industrially viable: titanates for complete causticizing during high temperature BLG, and borates for partial causticizing during high temperature BLG. These two cases were evaluated for integration into a gasification-based recovery island. The Larsen [28] BLG cost-benefit study was used as a reference case for economic forecasting (i.e. a 1500 tpd pulp mill using BLG and upgrading the lime cycle). By comparison, using the titanate direct causticizing process yielded a net present value (NPV) of $25M over the NPV of BLG with conventional lime cycle. Using the existing lime cycle plus borate autocausticizing for extra capacity yielded a NPV of $16M.« less

PROGRESS REPORT ON RAW MATERIALS FOR MAY 1957. Chemical Technology Div.

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

Brown, K.B.; Coleman, C.F.; Crouse, D.J.

1957-09-27

Systematic Studies. A mixed n-octyl-n-decyl tertiary amine, commercially available in development quantities, appeared promising for process use. Its U extraction power was similar to that of tri-n-octylamine, and loss by distribution to a sulfate liquor was lower. A corresponding secondary amine was similar in extraction behavior to di-n-decylamine, but loss by distribution was higher. Screening tests of U extraction power from diluteacid test solutions are summarized for various organophosphoras compounds, with principal attention to dialkylphosphinic acids, monoalkylphosphonic acids, and some polymeric compounds. Unusually high U extraction power was shown by in alpha -hydroxy phosphinic acid, phenyl(1hydroxy-2-ethylhexyl)phosphinic acid. Uranium(IV) was extractedmore » strongly from dilute icidic sulfate solution by a primary and s secondaryamine, but not bya tertiary amine. It was extracted more strongly than U/sup 6+/ from hydrochloric acid solutions by di(2-ethylhexyl)phosphoric acid (D2EHPA). In contrast to U/sup 6+/, U/sup 4+/ extraction by D2EHPA was enhanced little if any by the presence of TBP. Process Development. In tests with tri-iso-octylamine, a number of diluent additives were tested for ability to prevent separation of amine heteropolymolybdate precipitates from the usual kerosene-alcohol diluent during the chloride stripping cycle. Addition of nitrobenzeneat 100 g/liter was effective for this purpose. In other tests, several of the Mo precipitates were separated and analyzed for amine, Mo, phosphate,and V content. The amount of Mo reporting to U products from the Dapex process varied with the method and conditions by which uranium was precipitated from the sodium carbonate strip solution. Direct caustic precipitation of the U gave products essentially free of Mo although filtration characteristics of the precipitate were poor. When the U was recovered by first acidifying with H/sub 2/SO/sub 4/ and then precipitating with NH/sub 3/, most of the Mo remained in the product even when an excess of ammonia was used. Recovery by acidification and precipitation with caustic resulted in better Mo decontamination, particularly when an appreciable excess of caustic was added. Engineering Studies. The rate of U extraction from a synthetic H/sub 2/SO/sub 4/ leach liquor by a Dapex-tyne organic was proportional to the cube root of power input and was slightly faster in a 12-in. than in a 6- in. mixer at the same power input per unit volume. At a given power input the rate increased with decreased turbine diameter. Location of the turbine at one diameter from the bottom of the mixer tank provided only slightly faster extraction than at a center location. (For preceding period see ORNL-2346.) (auth)« less

Feasibility Study of an Optical Caustic Plasmonic Light Scattering Sensor for Human Serum Anti-Dengue Protein E Antibody Detection

PubMed Central

García, Antonio A.; Pirez-Gomez, Miguel A.; Pech-Pacheco, José L.; Mendez-Galvan, Jorge F.; Machain-Williams, Carlos; Talavera-Aguilar, Lourdes; Espinosa-Carrillo, José H.; Duarte-Villaseñor, Miriam M.; Be-Ortiz, Christian; Espinosa-de los Monteros, Luz E.; Castillo-Pacheco, Ariel; Garcia-Rejon, Julian E.

2017-01-01

Antibody detection and accurate diagnosis of tropical diseases is essential to help prevent the spread of disease. However, most detection methods lack cost-effectiveness and field portability, which are essential features for achieving diagnosis in a timely manner. To address this, 3D-printed oblate spheroid sample chambers were fabricated to measure green light scattering of gold nanoparticles using an optical caustic focus to detect antibodies. Scattering signals of 20–200 nm gold nanoparticles using a green laser were compared to green light emitting diode (LED) light source signals and to Mie theory. The change in signal from 60 to 120 nm decreased in the order of Mie Theory > optical caustic scattering > 90° scattering. These results suggested that conjugating 60 nm gold nanoparticles and using an optical caustic system to detect plasmonic light scattering, would result in a sensitive test for detecting human antibodies in serum. Therefore, we studied the light scattering response of conjugated gold nanoparticles exposed to different concentrations of anti-protein E antibody, and a feasibility study of 10 human serum samples using dot blot and a handheld optical caustic-based sensor device. The overall agreement between detection methods suggests that the new sensor concept shows promise to detect gold nanoparticle aggregation in a homogeneous assay. Further testing and protocol optimization is needed to draw conclusions on the positive and negative predictive values for this new testing system. PMID:28817080

Caustic stress corrosion cracking of alloys 600 and 690 with NaOH concentrations

NASA Astrophysics Data System (ADS)

Park, In-Gyu; Lee, Chang-Soon; Hwang, Seong-Sik; Kim, Hong-Pyo; Kim, Joung-Soo

2005-10-01

In order to evaluate the stress corrosion cracking resistance for commercial alloys (C600MA, C600TT, C690TT) and Korean-made alloys (K600MA, K690TT), C-ring tests were performed in a caustic environment of 4, 10, 20, 30, and 50% NaOH solution at 315°C, for 480 h with an applied potential of 125 mV vs. OCP. Different stress corrosion cracking phenomena were observed according to the NaOH concentration. The rate of caustic IGSCC attack did not appear to increase monotonically with caustic concentrations, but peaked at a concentration between 4 and 50% caustic, or approximately 30% NaOH. Intergranular stress corrosion cracking was found for C600MA in 10, 20, and 30% NaOH solutions, while no cracking was observed in the 4 and 50% NaOH solutions. In 30% NaOH solution, transgrnular stress corrosion cracking was detected in C690TT, which may be related with the large amount of plastic strain (150% yield) and the applied potential (125 mV vs. OCP). The overall data clearly indicate that C600MA has the worst SCC resistance while K690TT offers the best resistance. There is also fairly good correlation between the caustic SCC susceptibility and some metallurgical parameters, particularly the grain size and the yield strength at room temperature. Specifically, materials having larger grain size and lower yield strength exhibited higher caustic SCC resistance.

Sonic boom measurements from accelerating supersonic tracked sleds

NASA Technical Reports Server (NTRS)

Reed, J. W.

1974-01-01

Supersonic sled tests on the Sandia 1524-m (5000-ft) track generate sonic booms of sufficient intensity to allow some airblast measurements at distance scales not obtained from wind tunnel or flight tests. During acceleration, an emitted curved boom wave propagates to a caustic, or focus. Detailed measurements around these caustics may help to clarify the overpressure magnification which can occur from real aircraft operations. Six fixed pressure gages have been operated to document the general noise field, and a mobile array of twelve gages.

Alkaline flooding for enhanced oil recovery

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

Gittler, W.E.

1983-09-01

There are over 12 active projects of varying size using one of 3 major types of alkaline agents. These include sodium silicate, caustic soda, and soda ash. Among the largest pilots currently is the THUMS project in the Wilmington field, California. Plans called for the injection of a 4% weight concentration of sodium orthosilicate over a 60% PV. Through the first 3 yr, over 27 million bbl of chemicals have been injected. Gulf Oil is operating several alkaline floods, one of which is located off shore in the Quarantine Bay field, Louisiana. In this pilot, sodium hydroxide in a weightmore » concentration of 5 to 12% is being injected. Belco Petroleum Corp. has reported that their pilot operating in the Isenhour Unit in Wyoming is using a .5% weight concentration of soda ash in conjunction with a polymer. Other uses for alkaline agents in chemical flooding include the use of silicate as a preflush or sacrificial agent in micellar/polymer and surfactant recovery systems. In addition, caustic has been tested in the surface-mixed caustic emulsion process while orthosilicate has been tested in a recovery method known as mobility-controlled caustic floods.« less

Regeneration of iron-based adsorptive media used for removing arsenic from groundwater.

PubMed

Chen, Abraham S C; Sorg, Thomas J; Wang, Lili

2015-06-15

Adsorptive media technology is regarded as a simple, low cost method of removing arsenic from drinking water particularly for small systems. Currently, when the effluent of a treatment system reaches the USEPA maximum contaminant level (MCL) of 10 ug/L, the exhausted media is removed and replaced by new virgin media. Although the commonly used iron-based media products are reasonable in price, the replacement cost accounts for around 80% of the systems total operational costs. One option to media replacement is on-site regeneration and reuse of the exhausted media. To determine whether an iron based media can be successfully regenerated and reused, laboratory batch and column regeneration tests were conducted on six exhausted iron-based media products obtained from six full scale arsenic removal treatment systems. Batch tests conducted on three of the media products to evaluate the effectiveness of 1-6% caustic regenerant solutions found that arsenic desorption increased until around 4%. Using 4% caustic solutions, the columns tests on the six exhausted media products showed arsenic removals ranged from 25 to 90% with the best results obtained with the Severn Trent E33 media. Exposing the media to caustic (pH ≥ 13) and acid (pH ≤ 2) solutions found minimal media loss with the caustic solution, but significant media dissolution with a pH 2 acid solution. A six column pilot plant test at an Ohio test site with the lab regenerated media products found that the regenerated media could achieve arsenic removals somewhat similar to virgin media. Copyright © 2015 Elsevier Ltd. All rights reserved.

Speciation of arsenic, selenium, and chromium in wildfire impacted soils and ashes

USGS Publications Warehouse

Wolf, Ruth E.; Hoefen, Todd M.; Hageman, Philip L.; Morman, Suzette A.; Plumlee, Geoffrey S.

2010-01-01

In 2007-09, California experienced several large wildfires that damaged large areas of forest and destroyed many homes and buildings. The U.S. Geological Survey collected samples from the Harris, Witch, Grass Valley, Ammo, Santiago, Canyon, Jesusita, and Station fires for testing to identify any possible characteristics of the ashes and soils from burned areas that may be of concern for their impact on water quality, human health, and endangered species. The samples were subjected to analysis for bulk chemical composition for 44 elements by inductively coupled plasma mass spectrometry (ICP-MS) after acid digestion and de-ionized water leach tests for pH, alkalinity, conductivity, and anions. Water leach tests generated solutions ranging from pH 10-12, suggesting that ashes can generate caustic alkalinity in contact with rainwater or body fluids (for example, sweat and fluids in the respiratory tract). Samples from burned residential areas in the 2007 fires had elevated levels for several metals, including: As, Pb, Sb, Cu, Zn, and Cr. In some cases, the levels found were above the U.S. Environmental Protection Agency (USEPA) preliminary remediation goals (PRG) for soils. Speciation analyses were conducted on de-ionized water and simulated lung fluid leachates for As(III), As(V), Se(IV), Se(VI), Cr(III), and Cr(VI). All species were determined in the same analytical run using an ion-pairing HPLC-ICP-MS method. For leachates containing high levels of total Cr, the majority of the chromium was present in the hexavalent, Cr(VI), form. Higher total and hexavalent chromium levels were observed for samples collected from burned residential areas. Arsenic was also generally present in the more oxidized, As(V), form. Selenium (IV) and (VI) were present, but typically at levels below 2 ppb for most samples. Stability studies of leachate solutions under different storage conditions were performed and the suitability of different sample preservation methods for speciation analysis will be discussed.

Oil refinery hazardous effluents minimization by membrane filtration: An on-site pilot plant study.

PubMed

Santos, Bruno; Crespo, João G; Santos, Maria António; Velizarov, Svetlozar

2016-10-01

Experiments for treating two different types of hazardous oil refinery effluents were performed in order to avoid/minimize their adverse impacts on the environment. First, refinery wastewater was subjected to ultrafiltration using a ceramic membrane, treatment, which did not provide an adequate reduction of the polar oil and grease content below the maximal contaminant level allowed. Therefore the option of reducing the polar oil and grease contamination at its main emission source point in the refinery - the spent caustic originating from the refinery kerosene caustic washing unit - using an alkaline-resistant nanofiltration polymeric membrane treatment was tested. It was found that at a constant operating pressure and temperature, 99.9% of the oil and grease and 97.7% of the COD content were rejected at this emission point. Moreover, no noticeable membrane fouling or permeate flux decrease were registered until a spent caustic volume concentration factor of 3. These results allow for a reuse of the purified permeate in the refinery operations, instead of a fresh caustic solution, which besides the improved safety and environmentally related benefits, can result in significant savings of 1.5 M€ per year at the current prices for the biggest Portuguese oil refinery. The capital investment needed for nanofiltration treatment of the spent caustic is estimated to be less than 10% of that associated with the conventional wet air oxidation treatment of the spent caustic that is greater than 9 M€. The payback period was estimated to be 1.1 years. The operating costs for the two treatment options are similar, but the reuse of the nanofiltration spent caustic concentrate for refinery pH control applications can further reduce the operating expenditures. Overall, the pilot plant results obtained and the process economics evaluation data indicate a safer, environmentally friendly and highly competitive solution offered by the proposed nanofiltration treatment, thus representing a promising alternative to the use of conventional spent caustic treatment units. Copyright © 2016 Elsevier Ltd. All rights reserved.

POTENTIAL IMPACT OF BLENDING RESIDUAL SOLIDS FROM TANKS 18/19 MOUNDS WITH TANK 7 OPERATIONS

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

Eibling, R; Erich Hansen, E; Bradley Pickenheim, B

2007-03-29

High level waste tanks 18F and 19F have residual mounds of waste which may require removal before the tanks can be closed. Conventional slurry pump technology, previously used for waste removal and tank cleaning, has been incapable of removing theses mounds from tanks 18F and 19F. A mechanical cleaning method has been identified that is potentially capable of removing and transferring the mound material to tank 7F for incorporation in a sludge batch for eventual disposal in high level waste glass by the Defense Waste Processing Facility. The Savannah River National Laboratory has been requested to evaluate whether the materialmore » transferred from tanks 18F/19F by the mechanical cleaning technology can later be suspended in Tank 7F by conventional slurry pumps after mixing with high level waste sludge. The proposed mechanical cleaning process for removing the waste mounds from tanks 18 and 19 may utilize a high pressure water jet-eductor that creates a vacuum to mobilize solids. The high pressure jet is also used to transport the suspended solids. The jet-eductor system will be mounted on a mechanical crawler for movement around the bottom of tanks 18 and 19. Based on physical chemical property testing of the jet-eductor system processed IE-95 zeolite and size-reduced IE-95 zeolite, the following conclusions were made: (1) The jet-eductor system processed zeolite has a mean and median particle size (volume basis) of 115.4 and 43.3 microns in water. Preferential settling of these large particles is likely. (2) The jet-eductor system processed zeolite rapidly generates settled solid yield stresses in excess of 11,000 Pascals in caustic supernates and will not be easily retrieved from Tank 7 with the existing slurry pump technology. (3) Settled size-reduced IE-95 zeolite (less than 38 microns) in caustic supernate does not generate yield stresses in excess of 600 Pascals in less than 30 days. (4) Preferential settling of size-reduced zeolite is a function of the amount of sludge and the level of dilution for the mixture. (5) Blending the size-reduced zeolite into larger quantities of sludge can reduce the amount of preferential settling. (6) Periodic dilution or resuspension due to sludge washing or other mixing requirements will increase the chances of preferential settling of the zeolite solids. (7) Mixtures of Purex sludge and size-reduced zeolite did not produce yield stresses greater than 200 Pascals for settling times less than thirty days. Most of the sludge-zeolite blends did not exceed 50 Pascals. These mixtures should be removable by current pump technology if sufficient velocities can be obtained. (8) The settling rate of the sludge-zeolite mixtures is a function of the ionic strength (or supernate density) and the zeolite- sludge mixing ratio. (9) Simulant tests indicate that leaching of Si may be an issue for the processed Tank 19 mound material. (10) Floating zeolite fines observed in water for the jet-eductor system and size-reduced zeolite were not observed when the size-reduced zeolite was blended with caustic solutions, indicating that the caustic solutions cause the fines to agglomerate. Based on the test programs described in this report, the potential for successfully removing Tank 18/19 mound material from Tank 7 with the current slurry pump technology requires the reduction of the particle size of the Tank 18/19 mound material.« less

Results of Characterization and Retrieval Testing on Tank 241-C-109 Heel Solids

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

Callaway, William S.

Eight samples of heel solids from tank 241-C-109 were delivered to the 222-S Laboratory for characterization and dissolution testing. After being drained thoroughly, one-half to two-thirds of the solids were off-white to tan solids that, visually, were fairly evenly graded in size from coarse silt (30-60 μm) to medium pebbles (8-16 mm). The remaining solids were mostly strongly cemented aggregates ranging from coarse pebbles (16-32 mm) to fine cobbles (6-15 cm) in size. Solid phase characterization and chemical analysis indicated that the air-dry heel solids contained ≈58 wt% gibbsite [Al(OH){sub 3}] and ≈37 wt% natrophosphate [Na{sub 7}F(PO{sub 4}){sub 2}·19H{sub 2}O].more » The strongly cemented aggregates were mostly fine-grained gibbsite cemented with additional gibbsite. Dissolution testing was performed on two test samples. One set of tests was performed on large pieces of aggregate solids removed from the heel solids samples. The other set of dissolution tests was performed on a composite sample prepared from well-drained, air-dry heel solids that were crushed to pass a 1/4-in. sieve. The bulk density of the composite sample was 2.04 g/mL. The dissolution tests included water dissolution followed by caustic dissolution testing. In each step of the three-step water dissolution tests, a volume of water approximately equal to 3 times the initial volume of the test solids was added. In each step, the test samples were gently but thoroughly mixed for approximately 2 days at an average ambient temperature of 25 °C. The caustic dissolution tests began with the addition of sufficient 49.6 wt% NaOH to the water dissolution residues to provide ≈3.1 moles of OH for each mole of Al estimated to have been present in the starting composite sample and ≈2.6 moles of OH for each mole of Al potentially present in the starting aggregate sample. Metathesis of gibbsite to sodium aluminate was then allowed to proceed over 10 days of gentle mixing of the test samples at temperatures ranging from 26-30 °C. The metathesized sodium aluminate was then dissolved by addition of volumes of water approximately equal to 1.3 times the volumes of caustic added to the test slurries. Aluminate dissolution was allowed to proceed for 2 days at ambient temperatures of ≈29 °C. Overall, the sequential water and caustic dissolution tests dissolved and removed 80.0 wt% of the tank 241-C-109 crushed heel solids composite test sample. The 20 wt% of solids remaining after the dissolution tests were 85-88 wt% gibbsite. If the density of the residual solids was approximately equal to that of gibbsite, they represented ≈17 vol% of the initial crushed solids composite test sample. In the water dissolution tests, addition of a volume of water ≈6.9 times the initial volume of the crushed solids composite was sufficient to dissolve and recover essentially all of the natrophosphate present. The ratio of the weight of water required to dissolve the natrophosphate solids to the estimated weight of natrophosphate present was 8.51. The Environmental Simulation Program (OLI Systems, Inc., Morris Plains, New Jersey) predicts that an 8.36 w/w ratio would be required to dissolve the estimated weight of natrophosphate present in the absence of other components of the heel solids. Only minor amounts of Al-bearing solids were removed from the composite solids in the water dissolution tests. The caustic metathesis/aluminate dissolution test sequence, executed at temperatures ranging from 27-30 °C, dissolved and recovered ≈69 wt% of the gibbsite estimated to have been present in the initial crushed heel solids composite. This level of gibbsite recovery is consistent with that measured in previous scoping tests on the dissolution of gibbsite in strong caustic solutions. Overall, the sequential water and caustic dissolution tests dissolved and removed 80.3 wt% of the tank 241-C-109 aggregate solids test sample. The residual solids were 92-95 wt% gibbsite. Only a minor portion (≈4.5 wt%) of the aggregate solids was dissolved and recovered in the water dissolution test. Other than some smoothing caused by continuous mixing, the aggregates were essentially unaffected by the water dissolution tests. During the caustic metathesis/aluminate dissolution test sequence, ≈81 wt% of the gibbsite estimated to have been present in the aggregate solids was dissolved and recovered. The pieces of aggregate were significantly reduced in size but persisted as distinct pieces of solids. The increased level of gibbsite recovery, as compared to that for the crushed heel solids composite, suggests that the way the gibbsite solids and caustic solution are mixed is a key determinant of the overall efficiency of gibbsite dissolution and recovery. The liquids recovered after the caustic dissolution tests on the crushed solids composite and the aggregate solids were observed for 170 days. No precipitation of gibbsite was observed. The distribution of particle sizes in the residual solids recovered following the dissolution tests on the crushed heel solids composite was characterized. Wet sieving indicated that 21.4 wt% of the residual solids were >710 μm in size, and laser light scattering indicated that the median equivalent spherical diameter in the <710-μm solids was 35 μm. The settling behavior of the residual solids following the large-scale dissolution tests was also studied. When dispersed at a concentration of ≈1 vol% in water, ≈24 wt% of the residual solids settled at a rate >0.43 in./s; ≈68 wt% settled at rates between 0.02 and 0.43 in./s; and ≈7 wt% settled slower than 0.02 in./s.« less

In-situ caustic generation from sewage: the impact of caustic strength and sewage composition.

PubMed

Pikaar, Ilje; Rozendal, René A; Rabaey, Korneel; Yuan, Zhiguo

2013-10-01

Periodic caustic dosage is a commonly used method by the water industry to elevate pH levels and deactivate sewer biofilms responsible for hydrogen sulfide generation. Caustic (NaOH) can be generated in-situ from sewage using a divided electrochemical cell, which avoids the need for transport, handling and storage of concentrated caustic solutions. In this study, we investigated the impact of caustic strength in the cathode compartment and the impact of sodium concentration in sewage on the Coulombic efficiency (CE) for caustic generation. The CE was found to be independent of the caustic strength produced in the range of up to ~3 wt%. Results showed that a caustic solution of ~3 wt% could be produced directly from sewage at a CE of up to 75 ± 0.5%. The sodium concentration in sewage had a significant impact on the CE for caustic generation as well as on the energy requirements of the system, with a higher sodium concentration leading to a higher CE and lower energy consumption. The proton, calcium, magnesium and ammonium concentrations in sewage affected the CE for caustic generation, especially at low sodium concentrations. Economical assessment based on the experimental results indicated that sulfide control in sewers using electrochemically-generated caustic from sewage is an economically attractive strategy. Copyright © 2013 Elsevier Ltd. All rights reserved.

CHARACTERIZATION OF THE RESONANT CAUSTIC PERTURBATION

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

Chung, Sun-Ju, E-mail: sjchung@kasi.re.k

Four of nine exoplanets found by microlensing were detected by the resonant caustic, which represents the merging of the planetary and central caustics at the position when the projected separation of a host star and a bounded planet is s approx 1. One of the resonant caustic lensing events, OGLE-2005-BLG-169, was a caustic-crossing high-magnification event with A {sub max}approx 800 and the source star was much smaller than the caustic, nevertheless the perturbation was not obviously apparent on the light curve of the event. In this paper, we investigate the perturbation pattern of the resonant caustic to understand why themore » perturbations induced by the caustic do not leave strong traces on the light curves of high-magnification events despite a small source/caustic size ratio. From this study, we find that the regions with small magnification excess around the center of the resonant caustic are rather widely formed, and the event passing the small-excess region produces a high-magnification event with a weak perturbation that is small relative to the amplification caused by the star and thus does not noticeably appear on the light curve of the event. We also find that the positive excess of the inside edge of the resonant caustic and the negative excess inside the caustic become stronger and wider as q increases, and thus the resonant caustic-crossing high-magnification events with the weak perturbation occur in the range of q <= 10{sup -4}. We determine the probability of the occurrence of events with the small excess |epsilon| <= 3% in high-magnification events induced by a resonant caustic. As a result, we find that for Earth-mass planets with a separation of approx2.5 AU the resonant caustic high-magnification events with the weak perturbation can occur with a significant frequency.« less

Role of microstructure in caustic stress corrosion cracking of Alloy 690

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

Mertz, D.A.; Duda, P.T.; Pica, P.N.

1995-12-31

Alloy 690 has been selected for nuclear heat transport system tubing application in recent commercial reactor plants due to its resistance to multiple types of corrosion attack. Typical corn final heat treatments for this material are a mill-anneal (MA, approximately 1,070 C) to completely dissolve the carbides and develop the final grain structure plus a thermal treatment (TT, approximately 700 C) to precipitate carbides at the grain boundaries. Tubing with grain boundary carbides and no or few intragranular carbides has been found resistant to intergranular stress corrosion cracking (IGSCC) in caustic environments. In this work, first, Alloy 690 plate wasmore » subjected to a variety of MA and MA-TT heat treatments to create microstructures of carbide-decorated grain boundaries and undecorated boundaries. Caustic IGSCC test results were consistent with tubing data. Second, experiments were conducted to understand the mechanism by which caustic-corrosion resistance is imparted to Alloy 690 by grain boundary carbides. Tubing with a fully-developed MA-TT carbide microstructure was strained and heat-treated to create a mixed microstructure of new grain boundaries with no carbide precipitate decoration, intermixed with intragranular carbide strings from prior grain boundaries. Caustic SCC performance of this material was identical to that of material with the MA-TT carbide-decorated grain boundaries. This work suggests that the fundamental cause of good IGSCC resistance of MA-TT Alloy 690 in caustic does not derive solely from grain boundary carbides. It is suggested that matrix strength, as measured by yield stress, could be a controlling factor.« less

Laboratory scale Clean-In-Place (CIP) studies on the effectiveness of different caustic and acid wash steps on the removal of dairy biofilms.

PubMed

Bremer, Philip J; Fillery, Suzanne; McQuillan, A James

2006-02-15

A laboratory scale, bench top flow system was used to partially reproduce dairy plant conditions under which biofilms form and to quantify the effectiveness of caustic and acid wash steps in reducing the number of viable bacteria attached to stainless steel (SS) surfaces. Once bacteria attached to surfaces, a standard clean-in-place (CIP) regime (water rinse, 1% sodium hydroxide at 65 degrees C for 10 min, water rinse, 1.0% nitric acid at 65 degrees C for 10 min, water rinse) did not reproducibly ensure their removal. Standard CIP effectiveness was compared to alternative cleaning chemicals such as: caustic blends (Alkazolv 48, Ultrazolv 700, Concept C20, and Reflex B165); a caustic additive (Eliminator); acid blends (Nitroplus and Nitrobrite); and sanitizer (Perform). The addition of a caustic additive, Eliminator, enhanced biofilm removal compared to the standard CIP regime and further increases in cleaning efficiency occurred when nitric acid was substituted with Nitroplus. The combination of NaOH plus Eliminator and Nitroplus achieved a 3.8 log reduction in the number of cells recovered from the stainless steel surface. The incorporation of a sanitizer step into the CIP did not appear to enhance biofilm removal. This study has shown that the effectiveness of a "standard" CIP can possibly be enhanced through the testing and use of caustic and acid blends. There are many implications of these findings, including: the development of improved cleaning regimes and improved product quality, plant performance, and economic returns.

Duality of caustics in Minkowski billiards

NASA Astrophysics Data System (ADS)

Artstein-Avidan, S.; Florentin, D. I.; Ostrover, Y.; Rosen, D.

2018-04-01

In this paper we study convex caustics in Minkowski billiards. We show that for the Euclidean billiard dynamics in a planar smooth, centrally symmetric, strictly convex body K, for every convex caustic which K possesses, the ‘dual’ billiard dynamics in which the table is the Euclidean unit ball and the geometry that governs the motion is induced by the body K, possesses a dual convex caustic. Such a pair of caustics are dual in a strong sense, and in particular they have the same perimeter, Lazutkin parameter (both measured with respect to the corresponding geometries), and rotation number. We show moreover that for general Minkowski billiards this phenomenon fails, and one can construct a smooth caustic in a Minkowski billiard table which possesses no dual convex caustic.

Leaching Test Relationships, Laboratory-to-Field Comparisons and Recommendations for Leaching Evaluation using the Leaching Environmental Assessment Framework (LEAF)

EPA Science Inventory

This report presents examples of the relationships between the results of laboratory leaching tests, as defined by the Leaching Environmental Assessment Framework (LEAF) or analogous international test methods, and leaching of constituents from a broad range of materials under di...

Electrochemical sulfide removal and caustic recovery from spent caustic streams.

PubMed

Vaiopoulou, Eleni; Provijn, Thomas; Prévoteau, Antonin; Pikaar, Ilje; Rabaey, Korneel

2016-04-01

Spent caustic streams (SCS) are produced during alkaline scrubbing of sulfide containing sour gases. Conventional methods mainly involve considerable chemical dosing or energy expenditures entailing high cost but limited benefits. Here we propose an electrochemical treatment approach involving anodic sulfide oxidation preferentially to sulfur coupled to cathodic caustic recovery using a two-compartment electrochemical system. Batch experiments showed sulfide removal efficiencies of 84 ± 4% with concomitant 57 ± 4% efficient caustic production in the catholyte at a final concentration of 6.4 ± 0.1 wt% NaOH (1.6 M) at an applied current density of 100 A m(-2). Subsequent long-term continuous experiments showed that stable cell voltages (i.e. 2.7 ± 0.1 V) as well as constant sulfide removal efficiencies of 67 ± 5% at a loading rate of 47 g(S) L(-1) h(-1) were achieved over a period of 77 days. Caustic was produced at industrially relevant strengths for scrubbing (i.e. 5.1 ± 0.9 wt% NaOH) at current efficiencies of 96 ± 2%. Current density between 0 and 200 A m(-2) and sulfide loading rates of 50-200 g(S) L(-1) d(-1) were tested. The higher the current density the more oxidized the sulfur species produced and the higher the sulfide oxidation. On the contrary, high loading rate resulted in a reduction of sulfide oxidation efficiency. The results obtained in this study together with engineering calculations show that the proposed process could represent a cost-effective approach for sodium and sulfur recovery from SCS. Copyright © 2016 Elsevier Ltd. All rights reserved.

Identification And Characterization Of The Solids Found In Extraction Contactor SEP-401 In June 2012

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

Fondeur, F. F.; Fink, S. D.

2012-12-10

The Modular Caustic-Side Solvent Extraction Unit (MCU) recently conducted an outage that included maintenance on the centrifugal contactors. Operations personnel observed solids or deposits in two contactors and attempted to collect samples for analyses by Savannah River National Laboratory (SRNL). The residues found in Extraction Contactor SEP-401 are a mixture of amorphous silica, aluminosilicate, titanium, and debris from low alloy steel. The solids contain low concentrations of plutonium and strontium. These isotopes are associated with the titanium that came from the monosodium titanate (MST) added in the Actinide Removal Process (ARP) most likely as leached Ti from the MST thatmore » precipitated subsequently in MCU. An attempt was also made to obtain samples from the contents of Wash Contactor SEP-702. However, sampling provide ineffective.« less

Conformal chemically resistant coatings for microflow devices

DOEpatents

Folta, James A.; Zdeblick, Mark

2003-05-13

A process for coating the inside surfaces of silicon microflow devices, such as electrophoresis microchannels, with a low-stress, conformal (uniform) silicon nitride film which has the ability to uniformly coat deeply-recessed cavities with, for example, aspect ratios of up to 40:1 or higher. The silicon nitride coating allows extended exposure to caustic solutions. The coating enables a microflow device fabricated in silicon to be resistant to all classes of chemicals: acids, bases, and solvents. The process involves low-pressure (vacuum) chemical vapor deposition. The ultra-low-stress silicon nitride deposition process allows 1-2 .mu.m thick films without cracks, and so enables extended chemical protection of a silicon microflow device against caustics for up to 1 year. Tests have demonstrated the resistance of the films to caustic solutions at both ambient and elevated temperatures to 65.degree. C.

Caustics and Caustic-Interference in Measurements of Contact Angle and Flow Visualization Through Laser Shadowgraphy

NASA Technical Reports Server (NTRS)

Chao, David F.; Zhang, Neng-Li

2002-01-01

As one of the basic elements of the shadowgraphy optical system, the image of the far field from the droplet implicates plentiful information on the droplet profile. An analysis of caustics by wave theory shows that a droplet with a cylindrically symmetric Gaussian-hill-type profile produces a circular directional caustic in far field, which arises from the singularities (inflection line on the surface). The sessile liquid droplets, which profiles are restricted by surface tension, usually have a 'protruding foot' where the surface inflects. Simple geometrical optics indicates that the circular caustic stemming from the surface inflection at the protruding-foot takes the shape of the outmost ring on the image of the far field. It is the diameter of the outmost ring that is used as one of the key parameters in the measurements of contact angle through the laser shadowgraphic method. Different surface characteristics of the droplets produce different type of caustics, and therefore, the shape of the caustics can be used to determine the surface property of the sessile droplets. The present paper describes the measurement method of contact angIe using the circular caustics and the estimation of the protruding-foot height through the caustic interference.

Novel Use of Ophthalmic pH Paper to Diagnose Malicious Caustic Ingestion in a Pediatric Patient

PubMed Central

Bruno, Eric C.

2018-01-01

Occult caustic ingestion in the pediatric population is a challenging diagnosis to make in the emergency department. Failure to suspect and diagnose a caustic ingestion can lead to potentially life-changing comorbidities. Historically, the diagnosis of caustic ingestion has been clinical without any suitable diagnostic tools to aid in the suspicion of occult cases. In this case, we describe a novel use of ophthalmic pH paper to diagnose caustic ingestion in a three-year-old.

Caustics and the growth of droplets

NASA Astrophysics Data System (ADS)

Govindarajan, Rama; Ravichandran, S.; Ray, Samriddhi; Deepu, P.

Caustics are formed when inertial particles of very different velocities collide in a flow, and are a consequence of the dissipative nature of particle motion in a suspension. Using a model vortex-dominated flow with heavy droplets in a saturated environment, we suggest that sling caustics form only within a neighbourhood around a vortex, the square of whose radius is proportional to the product of circulation and particle inertia. Droplets starting close to this critical radius congregate very close together, resulting in large spikes in (Lagrangian) number density. Allowing for merger when droplets collide, we show that droplets starting out close to the critical radius display a much more rapid growth in size than those starting elsewhere, and a large fraction of the large droplets are those that originate within the caustics-forming region. We test these predictions in a two-dimensional simulation of turbulent flow. We hope that our study will be of interest in long-standing problems of physical interest such as the mechanism of broadening of droplet spectra in a turbulent flow. Support from the Ministry of Earth Sciences, Government of India for the project Coupled physical processes in the Bay of Bengal and monsoon air-sea interaction under OMM is gratefully acknowledged.

21 CFR 2.110 - Definition of ammonia under Federal Caustic Poison Act.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Definition of ammonia under Federal Caustic Poison... SERVICES GENERAL GENERAL ADMINISTRATIVE RULINGS AND DECISIONS Caustic Poisons § 2.110 Definition of ammonia under Federal Caustic Poison Act. For the purpose of determining whether an article containing ammonia...

21 CFR 2.110 - Definition of ammonia under Federal Caustic Poison Act.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Definition of ammonia under Federal Caustic Poison... SERVICES GENERAL GENERAL ADMINISTRATIVE RULINGS AND DECISIONS Caustic Poisons § 2.110 Definition of ammonia under Federal Caustic Poison Act. For the purpose of determining whether an article containing ammonia...

21 CFR 2.110 - Definition of ammonia under Federal Caustic Poison Act.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Definition of ammonia under Federal Caustic Poison... SERVICES GENERAL GENERAL ADMINISTRATIVE RULINGS AND DECISIONS Caustic Poisons § 2.110 Definition of ammonia under Federal Caustic Poison Act. For the purpose of determining whether an article containing ammonia...

21 CFR 2.110 - Definition of ammonia under Federal Caustic Poison Act.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Definition of ammonia under Federal Caustic Poison... SERVICES GENERAL GENERAL ADMINISTRATIVE RULINGS AND DECISIONS Caustic Poisons § 2.110 Definition of ammonia under Federal Caustic Poison Act. For the purpose of determining whether an article containing ammonia...

21 CFR 2.110 - Definition of ammonia under Federal Caustic Poison Act.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Definition of ammonia under Federal Caustic Poison... SERVICES GENERAL GENERAL ADMINISTRATIVE RULINGS AND DECISIONS Caustic Poisons § 2.110 Definition of ammonia under Federal Caustic Poison Act. For the purpose of determining whether an article containing ammonia...

Extraction, scrub, and strip test results for the salt waste processing facility caustic side solvent extraction solvent example

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

Peters, T. B.

An Extraction, Scrub, and Strip (ESS) test was performed on a sample of Salt Waste Processing Facility (SWPF) Caustic-Side Solvent Extraction (CSSX) solvent and salt simulant to determine cesium distribution ratios (D(Cs)), and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams; this data will be used by Parsons to help determine if the solvent is qualified for use at the SWPF. The ESS test showed acceptable performance of the solvent for extraction, scrub, and strip operations. The extraction D(Cs) measured 12.9, exceeding the required value of 8. This value is consistent with results from previousmore » ESS tests using similar solvent formulations. Similarly, scrub and strip cesium distribution ratios fell within acceptable ranges.« less

Reducing operating costs for struvite formation with a carbon dioxide stripper.

PubMed

Fattah, K P; Sabrina, N; Mavinic, D S; Koch, F A

2008-01-01

One of the major operational costs of phosphorus recovery as struvite is the cost of caustic chemical that is added to maintain a desired level of operative pH. A study was conducted at the Lulu Island Wastewater Treatment Plant (LIWWTP), Richmond, BC, using a struvite crystallizer and a cascade stripper designed at the University of British Columbia (UBC). The stripper was tested under different operating conditions to determine the effectiveness of CO(2) stripping in increasing the pH of the water matrix and thereby reducing caustic chemical use. This reduction is expected to reduce the operational costs of struvite production. Throughout the project, a high percentage (90%) of phosphorus removal was achieved under each condition. The cascade stripper was very effective in saving caustic usage, ranging from 35% to 86%, depending on the operating conditions. However, the stripper showed relatively poor performance regarding ammonia stripping. Copyright IWA Publishing 2008.

Hazardous Waste Minimization Assessment: Fort Campbell, Kentucky

DTIC Science & Technology

1991-03-01

Used Oii - Better Operating Practices . Selective Segregation 97 Used Oil - Process Change - Fast Lube Oil Change System (FLOCS) 98 Caustic Wastes...Product Substitution 98 Caustic Wastes - Process Change - Hot Tank (Equipment) Modifications 98 Aqueous or Caustic Wastes - Process Change - Dry Ovens...Aqueous or Caustic Wastes - Equipment Leasiag 102 Dirty Rags/Uniforms • Onsite/Offsite Recycling - Laundry Service 103 Treatment 103 Used Oil - Onsite

Generation of Caustics and Rogue Waves from Nonlinear Instability.

PubMed

Safari, Akbar; Fickler, Robert; Padgett, Miles J; Boyd, Robert W

2017-11-17

Caustics are phenomena in which nature concentrates the energy of waves and may exhibit rogue-type behavior. Although they are known mostly in optics, caustics are intrinsic to all wave phenomena. As we demonstrate in this Letter, the formation of caustics and consequently rogue events in linear systems requires strong phase fluctuations. We show that nonlinear phase shifts can generate sharp caustics from even small fluctuations. Moreover, in that the wave amplitude increases dramatically in caustics, nonlinearity is usually inevitable. We perform an experiment in an optical system with Kerr nonlinearity, simulate the results based on the nonlinear Schrödinger equation, and achieve perfect agreement. As the same theoretical framework is used to describe other wave systems such as large-scale water waves, our results may also aid the understanding of ocean phenomena.

Generation of Caustics and Rogue Waves from Nonlinear Instability

NASA Astrophysics Data System (ADS)

Safari, Akbar; Fickler, Robert; Padgett, Miles J.; Boyd, Robert W.

2017-11-01

Caustics are phenomena in which nature concentrates the energy of waves and may exhibit rogue-type behavior. Although they are known mostly in optics, caustics are intrinsic to all wave phenomena. As we demonstrate in this Letter, the formation of caustics and consequently rogue events in linear systems requires strong phase fluctuations. We show that nonlinear phase shifts can generate sharp caustics from even small fluctuations. Moreover, in that the wave amplitude increases dramatically in caustics, nonlinearity is usually inevitable. We perform an experiment in an optical system with Kerr nonlinearity, simulate the results based on the nonlinear Schrödinger equation, and achieve perfect agreement. As the same theoretical framework is used to describe other wave systems such as large-scale water waves, our results may also aid the understanding of ocean phenomena.

A preliminary cost analysis of the biotreatment of refinery spent-sulfidic caustic.

PubMed

Sublette, K L

1997-01-01

Caustics are used in petroleum refining to remove hydrogen sulfide from various hydrocarbon streams. Spent-sulfidic caustics from three refineries have been successfully biotreated on the bench and pilot scale, resulting in neutralization and removal of active Sulfides. Sulfides were completely oxidized to sulfate by Thiobacillus denitrificans strain F. Microbial oxidation of sulfide produced acid, which at least partially neutralized the caustic. A commercial-scale treatment system has been designed that features a bioreactor with a suspended culture of flocculated T. denitrificans, a settler and acid and nutrient storage and delivery systems. A cost analysis has been performed for nine cases representing a range of spent caustic sulfide and hydroxide concentrations at a base treatment rate of 10 gpm. This analysis shows that refinery spent-sulfidic caustic can be biotreated for 4-8.3 cent/gal.

The economic pre-treatment of coal mine drainage water with caustic and ozone.

PubMed

Boyden, B H; Nador, L; Addleman, S; Jeston, L

2017-09-01

Coal mine drainage waters are low in pH with varying amounts of iron and manganese and are generally brackish. The Austar Coal Mine in NSW, Australia, sought alternatives to their current lime dosing as the pre-treatment before the downstream reverse osmosis plant. Undesirable operating aspects of the current system include manganese and gypsum scaling/fouling, the need for anti-scalants and reduced water recovery. Thirteen processes for acid mine drainage were initially considered. The preferred process of caustic and ozone for Mn(II) oxidation was pilot tested at up to 0.74 kL/hr at the mine site. Under proper conditions and no aeration, about 81 per cent of the Fe could be removed (initially at 156 mg/L) as green rust. Supplemental aeration followed first-order kinetics and allowed 99.9 per cent Fe(II) oxidation and removal but only with a hydraulic residence time of about 47 minutes. The addition of supplemental Cu catalyst improved Fe removal. Ozone applied after caustic was effective in stoichiometrically oxidising recalcitrant Mn(II) and any remaining Fe(II). Control of the ozonation was achieved using the oxidation reduction potential during oxidation of the Mn(II) species. The use of caustic, followed by ozone, proved economically comparable to the current lime pre-treatment.

Gravitational lensing by ring-like structures

NASA Astrophysics Data System (ADS)

Lake, Ethan; Zheng, Zheng

2017-02-01

We study a class of gravitational lensing systems consisting of an inclined ring/belt, with and without an added point mass at the centre. We show that a common feature of such systems are so-called pseudo-caustics, across which the magnification of a point source changes discontinuously and yet remains finite. Such a magnification change can be associated with either a change in image multiplicity or a sudden change in the size of a lensed image. The existence of pseudo-caustics and the complex interplay between them and the formal caustics (which correspond to points of infinite magnification) can lead to interesting consequences, such as truncated or open caustics and a non-conservation of total image parity. The origin of the pseudo-caustics is found to be the non-differentiability of the solutions to the lens equation across the ring/belt boundaries, with the pseudo-caustics corresponding to ring/belt boundaries mapped into the source plane. We provide a few illustrative examples to understand the pseudo-caustic features, and in a separate paper consider a specific astronomical application of our results to study microlensing by extrasolar asteroid belts.

Structured caustic vector vortex optical field: manipulating optical angular momentum flux and polarization rotation.

PubMed

Chen, Rui-Pin; Chen, Zhaozhong; Chew, Khian-Hooi; Li, Pei-Gang; Yu, Zhongliang; Ding, Jianping; He, Sailing

2015-05-29

A caustic vector vortex optical field is experimentally generated and demonstrated by a caustic-based approach. The desired caustic with arbitrary acceleration trajectories, as well as the structured states of polarization (SoP) and vortex orders located in different positions in the field cross-section, is generated by imposing the corresponding spatial phase function in a vector vortex optical field. Our study reveals that different spin and orbital angular momentum flux distributions (including opposite directions) in different positions in the cross-section of a caustic vector vortex optical field can be dynamically managed during propagation by intentionally choosing the initial polarization and vortex topological charges, as a result of the modulation of the caustic phase. We find that the SoP in the field cross-section rotates during propagation due to the existence of the vortex. The unique structured feature of the caustic vector vortex optical field opens the possibility of multi-manipulation of optical angular momentum fluxes and SoP, leading to more complex manipulation of the optical field scenarios. Thus this approach further expands the functionality of an optical system.

IMPROVED ANTIFOAM AGENT STUDY END OF YEAR REPORT, EM PROJECT 3.2.3

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

Lambert, D.; Koopman, D.; Newell, J.

2011-09-30

Antifoam 747 is added to minimize foam produced by process gases and water vapor during chemical processing of sludge in the Defense Waste Processing Facility (DWPF). This allows DWPF to maximize acid addition and evaporation rates to minimize the cycle time in the Chemical Processing Cell (CPC). Improvements in DWPF melt rate due to the addition of bubblers in the melter have resulted in the need for further reductions in cycle time in the CPC. This can only be accomplished with an effective antifoam agent. DWPF production was suspended on March 22, 2011 as the result of a Flammable Gasmore » New Information/(NI) Potential Inadequacy in the Safety Analysis (PISA). The issue was that the DWPF melter offgas flammability strategy did not take into account the H and C in the antifoam, potentially flammable components, in the melter feed. It was also determined the DWPF was using much more antifoam than anticipated due to a combination of longer processing in the CPC due to high Hg, longer processing due to Actinide Removal Process (ARP)/Modular Caustic Side Solvent Extraction Unit (MCU) additions, and adding more antifoam than recommended. The resolution to the PISA involved and assessment of the impact of the antifoam on melter flammability and the implementation of a strategy to control additions within acceptable levels. This led to the need to minimize the use of Antifoam 747 in processing beginning in May 2011. DWPF has had limited success in using Antifoam 747 in caustic processing. Since starting up the ARP facility, the ARP product (similar chemically to caustic sludge) is added to the Sludge Receipt and Adjustment Tank (SRAT) at boiling and evaporated to maintain a constant SRAT volume. Although there is very little offgas generated during caustic boiling, there is a large volume of water vapor produced which can lead to foaming. High additions and more frequent use of antifoam are used to mitigate the foaming during caustic boiling. The result of these three issues above is that DWPF had three antifoam needs in FY2011: (1) Determine the cause of the poor Antifoam 747 performance during caustic boiling; (2) Determine the decomposition products of Antifoam 747 during CPC processing; and (3) Improve the effectiveness of Antifoam 747, in order to minimize the amount used. Testing was completed by Illinois Institute of Technology (IIT) and Savannah River National Laboratory (SRNL) researchers to address these questions. The testing results reported were funded by both DWPF and DOE/EM 31. Both sets of results are reported in this document for completeness. The results of this research are summarized: (1) The cause for the poor Antifoam 747 performance during caustic boiling was the high hydrolysis rate, cleaving the antifoam molecule in two, leading to poor antifoam performance. In testing with pH solutions from 1 to 13, the antifoam degraded quickly at a pH < 4 and pH > 10. As the antifoam decomposed it lost its spreading ability (wetting agent performance), which is crucial to its antifoaming performance. During testing of a caustic sludge simulants, there was more foam in tests with added Antifoam 747 than in tests without added antifoam. (2) Analyses were completed to determine the composition of the two antifoam components and Antifoam 747. In addition, the decomposition products of Antifoam 747 were determined during CPC processing of sludge simulants. The main decomposition products were identified primarily as Long Chain Siloxanes, boiling point > 400 C. Total antifoam recovery was 33% by mass. In a subsequent study, various compounds potentially related to antifoam were found using semi-volatile organic analysis and volatile organic analysis on the hexane extractions and hexane rinses. These included siloxanes, trimethyl silanol, methoxy trimethyl silane, hexamethyl disiloxane, aliphatic hydrocarbons, dioctyl phthalate, and emulsifiers. Cumulatively, these species amounted to less than 3% of the antifoam mass. The majority of the antifoam was identified using carbon analysis of the SRAT product (40-80% by mass) and silicon analysis (23-83% by mass) of the condensate. Both studies recommended a better solvent for antifoam and more specific tests for antifoam degradation products than the Si and C analyses used. (3) The DWPF Antifoam 747 Purchase Specification was revised in Month, 2011 with a goal of increasing the quality of Antifoam 747. The purchase specification was changed to specify the manufacturer and product for both components that are blended by Siovation to produce Antifoam 747 for DWPF. Testing of Antifoam produced using both the old and new antifoam specifications perform very similarly in testing. Since the change in purchase specification has not improved antifoam performance, an improved antifoam agent is required.« less

68. INTERIOR VIEW LOOKING OF THE CAUSTIC SODA (SODIUM HYDROXIDE) ...

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

68. INTERIOR VIEW LOOKING OF THE CAUSTIC SODA (SODIUM HYDROXIDE) BUILDING, LOOKING AT CAUSTIC SODA MEASURING TANKS. (DATE UNKNOWN). - United States Nitrate Plant No. 2, Reservation Road, Muscle Shoals, Muscle Shoals, Colbert County, AL

Analytical caustic surfaces

NASA Technical Reports Server (NTRS)

Schmidt, R. F.

1987-01-01

This document discusses the determination of caustic surfaces in terms of rays, reflectors, and wavefronts. Analytical caustics are obtained as a family of lines, a set of points, and several types of equations for geometries encountered in optics and microwave applications. Standard methods of differential geometry are applied under different approaches: directly to reflector surfaces, and alternatively, to wavefronts, to obtain analytical caustics of two sheets or branches. Gauss/Seidel aberrations are introduced into the wavefront approach, forcing the retention of all three coefficients of both the first- and the second-fundamental forms of differential geometry. An existing method for obtaining caustic surfaces through exploitation of the singularities in flux density is examined, and several constant-intensity contour maps are developed using only the intrinsic Gaussian, mean, and normal curvatures of the reflector. Numerous references are provided for extending the material of the present document to the morphologies of caustics and their associated diffraction patterns.

Stress corrosion cracking of duplex stainless steels in caustic solutions

NASA Astrophysics Data System (ADS)

Bhattacharya, Ananya

Duplex stainless steels (DSS) with roughly equal amount of austenite and ferrite phases are being used in industries such as petrochemical, nuclear, pulp and paper mills, de-salination plants, marine environments, and others. However, many DSS grades have been reported to undergo corrosion and stress corrosion cracking in some aggressive environments such as chlorides and sulfide-containing caustic solutions. Although stress corrosion cracking of duplex stainless steels in chloride solution has been investigated and well documented in the literature but the SCC mechanisms for DSS in caustic solutions were not known. Microstructural changes during fabrication processes affect the overall SCC susceptibility of these steels in caustic solutions. Other environmental factors, like pH of the solution, temperature, and resulting electrochemical potential also influence the SCC susceptibility of duplex stainless steels. In this study, the role of material and environmental parameters on corrosion and stress corrosion cracking of duplex stainless steels in caustic solutions were investigated. Changes in the DSS microstructure by different annealing and aging treatments were characterized in terms of changes in the ratio of austenite and ferrite phases, phase morphology and intermetallic precipitation using optical micrography, SEM, EDS, XRD, nano-indentation and microhardness methods. These samples were then tested for general and localized corrosion susceptibility and SCC to understand the underlying mechanisms of crack initiation and propagation in DSS in the above-mentioned environments. Results showed that the austenite phase in the DSS is more susceptible to crack initiation and propagation in caustic solutions, which is different from that in the low pH chloride environment where the ferrite phase is the more susceptible phase. This study also showed that microstructural changes in duplex stainless steels due to different heat treatments could affect their SCC susceptibility. Annealed and water quenched specimens were found to be immune to SCC in caustic environment. Aging treatment at 800°C gave rise to sigma and chi precipitates in the DSS. However, these sigma and chi precipitates, known to initiate cracking in DSS in chloride environment did not cause any cracking of DSS in caustic solutions. Aging of DSS at 475°C had resulted in '475°C embrittlement' and caused cracks to initiate in the ferrite phase. This was in contrast to the cracks initiating in the austenite phase in the as-received DSS. Alloy composition and microstructure of DSS as well as solution composition (dissolved ionic species) was also found to affect the electrochemical behavior and passivation of DSS which in turn plays a major role in stress corrosion crack initiation and propagation. Corrosion rates and SCC susceptibility of DSS was found to increase with addition of sulfide to caustic solutions. Corrosion films on DSS, characterized using XRD and X-ray photoelectron spectroscopy, indicated that the metal sulfide compounds were formed along with oxides at the metal surface in the presence of sulfide containing caustic environments. These metal sulfide containing passive films are unstable and hence breaks down under mechanical straining, leading to SCC initiations. The overall results from this study helped in understanding the mechanism of SCC in caustic solutions. Favorable slip systems in the austenite phase of DSS favors slip-induced local film damage thereby initiating a stress corrosion crack. Repeated film repassivation and breaking, followed by crack tip dissolution results in crack propagation in the austenite phase of DSS alloys. Result from this study will have a significant impact in terms of identifying the alloy compositions, fabrication processes, microstructures, and environmental conditions that may be avoided to mitigate corrosion and stress corrosion cracking of DSS in caustic solutions.

Evaluation and Management of Caustic Injuries from Ingestion of Acid or Alkaline Substances

PubMed Central

2014-01-01

Although the numbers have decreased compared with in the past, cases of patients who ingest caustic substances and visit the emergency room are not rare. However, well-summarized data about caustic injuries are insufficient. Therefore, in this article, I will discuss the etiologic causative agents, injury mechanism, and clinical characteristics, as well as the endoscopic evaluation of the degree of injury and proper management of the patient, in gastrointestinal caustic injury. PMID:25133115

Mid-Frequency Reverberation Measurements with Full Companion Environmental Support

DTIC Science & Technology

2014-12-30

it reaches a caustic . Beyond the caustic , it is only a saddle point [12]; there are distortions of the ray that give shorter travel times. Each of the...rays TBT, TB, and BT has at least one caustic . Thus, the argument must be modified. The following modified argument also uses Fermat’s prin- ciple...travel time decreased by about 1 ms. The presence of caustics invalidates a straightforward Fermat’s principle in- terpretation with a minimum travel

Optical caustics associated with the primary and the secondary rainbows of oblate droplets

NASA Astrophysics Data System (ADS)

Yu, Haitao; Shen, Jianqi; Tropea, Cameron

2014-08-01

The vector ray tracing (VRT) model is used to simulate the optical caustic structures near the primary and the secondary rainbow angles of oblate water droplets. The evolution process of the optical caustic structures in response to shape deformation of the water droplet is discussed. The dependence of the caustic structures on equatorial radius, refractive index and aspect ratio of the droplet are studied and the curvatures of the two rainbow fringes are calculated.

Dual behavior of caustic optical beams facing obstacles

NASA Astrophysics Data System (ADS)

Vaveliuk, Pablo; Martínez-Matos, Óscar; Ren, Yu-Xuan; Lu, Rong-De

2017-06-01

A full propagation analysis on both fold-type and cusp-type caustic optical beams under various setups of obstructions is theoretically and experimentally performed. It is demonstrated that the self-healing property of caustic optical beams that include the famous Airy beam is a quite relative property. In fact, fold-type and cusp-type beams cannot only behave as self-healing beams by blocking the main intensity peak, but also behave as self-breaking ones in a nonintuitive manner: by blocking a lateral side of the beam without touching the central intensity peak. The regeneration and rupture processes of caustic beams follow a nonlocal propagation dynamic unlike the other conventional beams. Moreover, deep differences between fold and cusp caustic beams are pointed out once facing certain obstructions. The cusp-caustic beam can be broken down by the obstacle placed in a dark zone outside the caustic region, while the fold-type one remains unaltered. This beam rupture confirms the key role of a hidden propagating field in the shadow region for cusp beams that coexist with the evanescent one. The obtained results cast down the established idea that the Airy beam is a robust self-healing beam since any caustic beam can behave in a dual manner depending on the obstruction location. These facts open up different perspectives for the applications in which the self-healing properties of the beam are relevant.

Effect of magnetic starch on the clarification of hematite tailings wastewater

NASA Astrophysics Data System (ADS)

Yue, Tao; Wu, Xiqing

2018-02-01

The magnetic starch solution, synthesized by mixing the caustic starch, the Fe2+ solution (in some cases containing the Zn2+, Cu2+, Mn2+ or Mg2+ ions) and H2O2 solution, was used as the flocculant to investigate its clarification effect on hematite tailings wastewater. Based on the clarification tests and adsorption analysis it was demonstrated that the magnetic starch produced better clarification effect than the caustic starch, and the adsorption of magnetic starch onto hematite tailings particles was also stronger than the caustic starch. AFM found that the magnetic interaction between magnetic seeds and hematite is characteristic of long range force and greatly strengthens the adsorption of magnetic seeds onto fine hematite for agglomeration. FTIR indicates the starch adsorbed onto the surfaces of hematite and magnetic seeds, thus acting as the bridging between hematite particles and magnetic seeds, resulting in an intensified coverage of the starch onto hematite and positive action in the clarification.

Caustics for spherical waves

DOE PAGES

de Rham, Claudia; Motohashi, Hayato

2017-03-07

We study the development of caustics in shift-symmetric scalar field theories by focusing on simple waves with an S O ( p ) -symmetry in an arbitrary number of space dimensions. We show that the pure Galileon, the DBI–Galileon, and the extreme-relativistic Galileon naturally emerge as the unique set of caustic-free theories, highlighting a link between the caustic-free condition for simple S O ( p ) -waves and the existence of either a global Galilean symmetry or a global (extreme-)relativistic Galilean symmetry.

Comparison of mine waste assessment methods at the Rattler mine site, Virginia Canyon, Colorado

USGS Publications Warehouse

Hageman, Phil L.; Smith, Kathleen S.; Wildeman, Thomas R.; Ranville, James F.

2005-01-01

In a joint project, the mine waste-piles at the Rattler Mine near Idaho Springs, Colorado, were sampled and analyzed by scientists from the U.S. Geological Survey (USGS) and the Colorado School of Mines (CSM). Separate sample collection, sample leaching, and leachate analyses were performed by both groups and the results were compared. For the study, both groups used the USGS sampling procedure and the USGS Field Leach Test (FLT). The leachates generated from these tests were analyzed for a suite of elements using ICP-AES (CSM) and ICP-MS (USGS). Leachate geochemical fingerprints produced by the two groups for composites collected from the same mine waste showed good agreement. In another set of tests, CSM collected another set of Rattler mine waste composite samples using the USGS sampling procedure. This set of composite samples was leached using the Colorado Division of Minerals and Geology (CDMG) leach test, and a modified Toxicity Characteristic Leaching Procedure (TCLP) leach test. Leachate geochemical fingerprints produced using these tests showed a variation of more than a factor of two from the geochemical fingerprints produced using the USGS FLT leach test. We have concluded that the variation in the results is due to the different parameters of the leaching tests and not due to the sampling or analytical methods.

A New Generation of Leaching Tests – The Leaching Environmental Assessment Framework

EPA Science Inventory

Provides an overview of newly released leaching tests that provide a more accurate source term when estimating environmental release of metals and other constituents of potential concern (COPCs). The Leaching Environmental Assessment Framework (LEAF) methods have been (1) develo...

Analysis of sonic boom measurements near shock wave extremities for flight near Mach 1.0 and for airplane accelerations

NASA Technical Reports Server (NTRS)

Haglund, G. T.; Kane, E. J.

1974-01-01

The analysis of the 14 low-altitude transonic flights showed that the prevailing meteorological consideration of the acoustic disturbances below the cutoff altitude during threshold Mach number flight has shown that a theoretical safe altitude appears to be valid over a wide range of meteorological conditions and provides a reasonable estimate of the airplane ground speed reduction to avoid sonic boom noise during threshold Mach number flight. Recent theoretical results for the acoustic pressure waves below the threshold Mach number caustic showed excellent agreement with observations near the caustic, but the predicted overpressure levels were significantly lower than those observed far from the caustic. The analysis of caustics produced by inadvertent low-magnitude accelerations during flight at Mach numbers slightly greater than the threshold Mach number showed that folds and associated caustics were produced by slight changes in the airplane ground speed. These caustic intensities ranged from 1 to 3 time the nominal steady, level flight intensity.

RELATIVE LEACHING AND AQUATIC TOXICITY OF PRESSURE-TREATED WOOD PRODUCTS USING BATCH LEACHING TESTS

EPA Science Inventory

Samples of southern yellow pine dimensional lumber, each treated with one of five different waterborne chemical preservatives, were leached using 18-hour batch leaching tests. The wood preservatives included chromated copper arsenate (CCA), alkaline copper quaternary (ACQ), coppe...

U.S. Geological Survey Field Leach Test for Assessing Water Reactivity and Leaching Potential of Mine Wastes, Soils, and Other Geologic and Environmental Materials

USGS Publications Warehouse

Hageman, Philip L.

2007-01-01

The U. S. Geological Survey (USGS) has developed a fast (5-minute), effective, simple, and cost-effective leach test that can be used to simulate the reactions that occur when materials are leached by water. The USGS Field Leach Test has been used to predict, assess, and characterize the geochemical interactions between water and a broad variety of geologic and environmental matrices. Examples of some of the samples leached include metal mine wastes, various types of dusts, biosolids (processed sewage sludge), flood and wetland sediments, volcanic ash, forest-fire burned soils, and many other diverse matrices. The Field Leach Test has been an integral part of these investigations and has demonstrated its value as a geochemical characterization tool. It has enabled investigators to identify which constituents are water reactive, soluble, mobilized, and made bioaccessible because of leaching by water, and to understand potential impacts of these interactions on the surrounding environment.

Upscaling the pollutant emission from mixed recycled aggregates under compaction for civil applications.

PubMed

Galvín, Adela P; Ayuso, Jesús; Barbudo, Auxi; Cabrera, Manuel; López-Uceda, Antonio; Rosales, Julia

2017-12-27

In general terms, plant managers of sites producing construction wastes assess materials according to concise, legally recommended leaching tests that do not consider the compaction stage of the materials when they are applied on-site. Thus, the tests do not account for the real on-site physical conditions of the recycled aggregates used in civil works (e.g., roads or embankments). This leads to errors in estimating the pollutant potential of these materials. For that reason, in the present research, an experimental procedure is designed as a leaching test for construction materials under compaction. The aim of this laboratory test (designed specifically for the granular materials used in civil engineering infrastructures) is to evaluate the release of pollutant elements when the recycled aggregate is tested at its commercial grain-size distribution and when the material is compacted under on-site conditions. Two recycled aggregates with different gypsum contents (0.95 and 2.57%) were used in this study. In addition to the designed leaching laboratory test, the conventional compliance leaching test and the Dutch percolation test were performed. The results of the new leaching method were compared with the conventional leaching test results. After analysis, the chromium and sulphate levels obtained from the newly designed test were lower than those obtained from the conventional leaching test, and these were considered more seriously pollutant elements. This result confirms that when the leaching behaviour is evaluated for construction aggregates without density alteration, crushing the aggregate and using only the finest fraction, as is done in the conventional test (which is an unrealistic situation for aggregates that are applied under on-site conditions), the leaching behaviour is not accurately assessed.

CHARACTERIZATION AND EVALUATION OF CAUSTIC WASH TANK AND SOLVENT HOLD TANK SAMPLES FROM MCU FROM AUGUST TO SEPTEMBER 2011

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

Fondeur, F.; Fink, S.

2012-08-01

During processing of Salt Batches 3 and 4 in the Modular Caustic-Side Solvent Extraction Unit (MCU), the decontamination efficiency for cesium declined from historical values and from expectations based on laboratory testing. This report documents efforts to analyze samples of solvent and process solutions from MCU in an attempt to understand the cause of the reduced performance and to recommend mitigations. CWT Solutions from MCU from the time period of variable decontamination factor (DF) performance which covers from April 2011 to September 2011 (during processing of Salt Batch 4) were examined for impurities using chromatography and spectroscopy. The results indicatemore » that impurities were found to be of two types: aromatic containing impurities most likely from Modifier degradation and aliphatic type impurities most likely from Isopar{reg_sign} L and tri-n-octylamine (TOA) degradation. Caustic washing the Solvent Hold Tank (SHT) solution with 1M NaOH improved its extraction ability as determined from {sup 22}Na uptake tests. Evidence from this work showed that pH variance in the aqueous solutions within the range of 1M nitric acid to 1.91M NaOH that contacted the solvent samples does not influence the analytical determination of the TOA concentration by GC-MS.« less

Hydraulic and environmental behavior of recycled asphalt pavement in highway shoulder applications

DOT National Transportation Integrated Search

2017-10-01

Hydraulic conductivity of seven recycled asphalt pavement materials (RAPs) was evaluated through a series of constant-head tests, while their leaching potential was determined through batch leach tests and column leach tests. The contaminant transpor...

IDENTIFICATION OF MEMBERS IN THE CENTRAL AND OUTER REGIONS OF GALAXY CLUSTERS

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

Serra, Ana Laura; Diaferio, Antonaldo, E-mail: serra@ph.unito.it

2013-05-10

The caustic technique measures the mass of galaxy clusters in both their virial and infall regions and, as a byproduct, yields the list of cluster galaxy members. Here we use 100 galaxy clusters with mass M{sub 200} {>=} 10{sup 14} h {sup -1} M{sub Sun} extracted from a cosmological N-body simulation of a {Lambda}CDM universe to test the ability of the caustic technique to identify the cluster galaxy members. We identify the true three-dimensional members as the gravitationally bound galaxies. The caustic technique uses the caustic location in the redshift diagram to separate the cluster members from the interlopers. Wemore » apply the technique to mock catalogs containing 1000 galaxies in the field of view of 12 h {sup -1} Mpc on a side at the cluster location. On average, this sample size roughly corresponds to 180 real galaxy members within 3r{sub 200}, similar to recent redshift surveys of cluster regions. The caustic technique yields a completeness, the fraction of identified true members, f{sub c} = 0.95 {+-} 0.03, within 3r{sub 200}. The contamination, the fraction of interlopers in the observed catalog of members, increases from f{sub i}=0.020{sup +0.046}{sub -0.015} at r{sub 200} to f{sub i}=0.08{sup +0.11}{sub -0.05} at 3r{sub 200}. No other technique for the identification of the members of a galaxy cluster provides such large completeness and small contamination at these large radii. The caustic technique assumes spherical symmetry and the asphericity of the cluster is responsible for most of the spread of the completeness and the contamination. By applying the technique to an approximately spherical system obtained by stacking the individual clusters, the spreads decrease by at least a factor of two. We finally estimate the cluster mass within 3r{sub 200} after removing the interlopers: for individual clusters, the mass estimated with the virial theorem is unbiased and within 30% of the actual mass; this spread decreases to less than 10% for the spherically symmetric stacked cluster.« less

Underwater Rays

ERIC Educational Resources Information Center

Cepic, Mojca

2008-01-01

Light beams in wavy unclear water, also called underwater rays, and caustic networks of light formed at the bottom of shallow water are two faces of a single phenomenon. Derivation of the caustic using only simple geometry, Snell's law and simple derivatives accounts for observations such as the existence of the caustic network on vertical walls,…

21 CFR 1230.43 - Enforcement.

Code of Federal Regulations, 2011 CFR

2011-04-01

... CAUSTIC POISON ACT Imports § 1230.43 Enforcement. (a) Enforcement agency. The Federal Caustic Poison Act...) Enforcement of provisions. The enforcement of the provisions of the Federal Caustic Poison Act as they relate... Poison Act. (c) Chief of district as customs officer. The chief of district shall be deemed a customs...

21 CFR 1230.43 - Enforcement.

Code of Federal Regulations, 2014 CFR

2014-04-01

... CAUSTIC POISON ACT Imports § 1230.43 Enforcement. (a) Enforcement agency. The Federal Caustic Poison Act...) Enforcement of provisions. The enforcement of the provisions of the Federal Caustic Poison Act as they relate... Poison Act. (c) Chief of district as customs officer. The chief of district shall be deemed a customs...

21 CFR 1230.21 - Specific guaranty.

Code of Federal Regulations, 2012 CFR

2012-04-01

... FEDERAL CAUSTIC POISON ACT Guaranty § 1230.21 Specific guaranty. If a guaranty in respect to any specific... Caustic Poison Act. (Signature and address of guarantor) (b) Substances for other than household use (this... be misbranded within the meaning of the Federal Caustic Poison Act. (Name and address of manufacturer...

21 CFR 1230.21 - Specific guaranty.

Code of Federal Regulations, 2014 CFR

2014-04-01

... FEDERAL CAUSTIC POISON ACT Guaranty § 1230.21 Specific guaranty. If a guaranty in respect to any specific... Caustic Poison Act. (Signature and address of guarantor) (b) Substances for other than household use (this... be misbranded within the meaning of the Federal Caustic Poison Act. (Name and address of manufacturer...

21 CFR 1230.21 - Specific guaranty.

Code of Federal Regulations, 2010 CFR

2010-04-01

... FEDERAL CAUSTIC POISON ACT Guaranty § 1230.21 Specific guaranty. If a guaranty in respect to any specific... Caustic Poison Act. (Signature and address of guarantor) (b) Substances for other than household use (this... be misbranded within the meaning of the Federal Caustic Poison Act. (Name and address of manufacturer...

21 CFR 1230.43 - Enforcement.

Code of Federal Regulations, 2013 CFR

2013-04-01

... CAUSTIC POISON ACT Imports § 1230.43 Enforcement. (a) Enforcement agency. The Federal Caustic Poison Act...) Enforcement of provisions. The enforcement of the provisions of the Federal Caustic Poison Act as they relate... Poison Act. (c) Chief of district as customs officer. The chief of district shall be deemed a customs...

21 CFR 1230.21 - Specific guaranty.

Code of Federal Regulations, 2013 CFR

2013-04-01

... FEDERAL CAUSTIC POISON ACT Guaranty § 1230.21 Specific guaranty. If a guaranty in respect to any specific... Caustic Poison Act. (Signature and address of guarantor) (b) Substances for other than household use (this... be misbranded within the meaning of the Federal Caustic Poison Act. (Name and address of manufacturer...

21 CFR 1230.21 - Specific guaranty.

Code of Federal Regulations, 2011 CFR

2011-04-01

... FEDERAL CAUSTIC POISON ACT Guaranty § 1230.21 Specific guaranty. If a guaranty in respect to any specific... Caustic Poison Act. (Signature and address of guarantor) (b) Substances for other than household use (this... be misbranded within the meaning of the Federal Caustic Poison Act. (Name and address of manufacturer...

21 CFR 1230.43 - Enforcement.

Code of Federal Regulations, 2012 CFR

2012-04-01

... CAUSTIC POISON ACT Imports § 1230.43 Enforcement. (a) Enforcement agency. The Federal Caustic Poison Act...) Enforcement of provisions. The enforcement of the provisions of the Federal Caustic Poison Act as they relate... Poison Act. (c) Chief of district as customs officer. The chief of district shall be deemed a customs...

21 CFR 1230.43 - Enforcement.

Code of Federal Regulations, 2010 CFR

2010-04-01

... CAUSTIC POISON ACT Imports § 1230.43 Enforcement. (a) Enforcement agency. The Federal Caustic Poison Act...) Enforcement of provisions. The enforcement of the provisions of the Federal Caustic Poison Act as they relate... Poison Act. (c) Chief of district as customs officer. The chief of district shall be deemed a customs...

The internal caustic structure of illuminated liquid droplets

NASA Technical Reports Server (NTRS)

Lock, James A.; Hovenac, Edward A.

1991-01-01

The internal electric field of an illuminated liquid droplet is studied in detail using both wave theory and ray theory. The internal field obtains its maximum values on the caustics within the droplet. Ray theory is used to determine the equations of these caustics and the density of rays on them. The Debye series expansion of the interior field Mie amplitudes is used to calculate the wave theory version of these caustics. The physical interpretation of the sources of stimulated Raman scattering and fluorescence emission within a liquid droplet is then given.

COMPARATIVE EVALUATION OF SHORT-TERM LEACH TESTS FOR HEAVY METAL RELEASE FROM MINERAL PROCESSING WASTE

EPA Science Inventory

Evaluation of metal leaching using a single leach test such as the Toxicity Characteristic Leaching Procedure (TCLP) is often questionable. The pH, redox potential (E_h), particle size and contact time are critical variables in controlling metal stability, not accounted...

Extraction, Scrub, and Strip Test Results for the Salt Waste Processing Facility Caustic Side Solvent Extraction Solvent Sample

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

Peters, T. B.

An Extraction, Scrub, and Strip (ESS) test was performed on a sample of Salt Waste Processing Facility (SWPF) Caustic-Side Solvent Extraction (CSSX) solvent and salt simulant to determine cesium distribution ratios (D( Cs)), and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams; this data will be used by Parsons to help determine if the solvent is qualified for use at the SWPF. The ESS test showed acceptable performance of the solvent for extraction, scrub, and strip operations. The extraction D( Cs) measured 12.5, exceeding the required value of 8. This value is consistent with resultsmore » from previous ESS tests using similar solvent formulations. Similarly, scrub and strip cesium distribution ratios fell within acceptable ranges. This revision was created to correct an error. The previous revision used an incorrect set of temperature correction coefficients which resulted in slight deviations from the correct D( Cs) results.« less

Ranking Coal Ash Materials for Their Potential to Leach Arsenic and Selenium: Relative Importance of Ash Chemistry and Site Biogeochemistry

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

Schwartz, Grace E.; Hower, James C.; Phillips, Allison L.

The chemical composition of coal ash is highly heterogeneous and dependent on the origin of the source coal, combustion parameters, and type and configuration of air pollution control devices. This heterogeneity results in uncertainty in the evaluation of leaching potential of contaminants from coal ash. The goal of this work was to identify whether a single leaching protocol could roughly group high-leaching potential coal ash from low-leaching potential coal ash, with respect to arsenic (As) and selenium (Se). We used four different leaching tests, including the Toxicity Characteristic Leaching Protocol (TCLP), natural pH, aerobic sediment microcosms, and anaerobic sediment microcosmsmore » on 10 different coal ash materials, including fly ash, lime-treated ash, and flue gas desulfurization materials. Leaching tests showed promise in categorizing high and low-leaching potential ash materials, indicating that a single point test could act as a first screening measure to identify high-risk ash materials. However, the amount of contaminant leached varied widely across tests, reflecting the importance of ambient conditions (pH, redox state) on leaching. These results demonstrate that on-site geochemical conditions play a critical role in As and Se mobilization from coal ash, underscoring the need to develop a situation-based risk assessment framework for contamination by coal ash pollutants.« less

Ranking Coal Ash Materials for Their Potential to Leach Arsenic and Selenium: Relative Importance of Ash Chemistry and Site Biogeochemistry

DOE PAGES

Schwartz, Grace E.; Hower, James C.; Phillips, Allison L.; ...

2018-01-23

The chemical composition of coal ash is highly heterogeneous and dependent on the origin of the source coal, combustion parameters, and type and configuration of air pollution control devices. This heterogeneity results in uncertainty in the evaluation of leaching potential of contaminants from coal ash. The goal of this work was to identify whether a single leaching protocol could roughly group high-leaching potential coal ash from low-leaching potential coal ash, with respect to arsenic (As) and selenium (Se). We used four different leaching tests, including the Toxicity Characteristic Leaching Protocol (TCLP), natural pH, aerobic sediment microcosms, and anaerobic sediment microcosmsmore » on 10 different coal ash materials, including fly ash, lime-treated ash, and flue gas desulfurization materials. Leaching tests showed promise in categorizing high and low-leaching potential ash materials, indicating that a single point test could act as a first screening measure to identify high-risk ash materials. However, the amount of contaminant leached varied widely across tests, reflecting the importance of ambient conditions (pH, redox state) on leaching. These results demonstrate that on-site geochemical conditions play a critical role in As and Se mobilization from coal ash, underscoring the need to develop a situation-based risk assessment framework for contamination by coal ash pollutants.« less

Experimental and numerical analysis of metal leaching from fly ash-amended highway bases

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

Cetin, Bora; Aydilek, Ahmet H., E-mail: aydilek@umd.edu; Li, Lin

2012-05-15

Highlights: Black-Right-Pointing-Pointer This study is the evaluation of leaching potential of fly ash-lime mixed soils. Black-Right-Pointing-Pointer This objective is met with experimental and numerical analysis. Black-Right-Pointing-Pointer Zn leaching decreases with increase in fly ash content while Ba, B, Cu increases. Black-Right-Pointing-Pointer Decrease in lime content promoted leaching of Ba, B and Cu while Zn increases. Black-Right-Pointing-Pointer Numerical analysis predicted lower field metal concentrations. - Abstract: A study was conducted to evaluate the leaching potential of unpaved road materials (URM) mixed with lime activated high carbon fly ashes and to evaluate groundwater impacts of barium, boron, copper, and zinc leaching. Thismore » objective was met by a combination of batch water leach tests, column leach tests, and computer modeling. The laboratory tests were conducted on soil alone, fly ash alone, and URM-fly ash-lime kiln dust mixtures. The results indicated that an increase in fly ash and lime content has significant effects on leaching behavior of heavy metals from URM-fly ash mixture. An increase in fly ash content and a decrease in lime content promoted leaching of Ba, B and Cu whereas Zn leaching was primarily affected by the fly ash content. Numerically predicted field metal concentrations were significantly lower than the peak metal concentrations obtained in laboratory column leach tests, and field concentrations decreased with time and distance due to dispersion in soil vadose zone.« less

Evaluation of the impact of lime softening waste disposal in natural environments

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

Blaisi, Nawaf I.; Roessler, Justin; Cheng, Weizhi

2015-09-15

Highlights: • Leaching tests conducted on WTR to assess potential for trace element release. • Aluminum leaching found to be elevated with respect to risk threshold. • Release in anaerobic conditions evaluated with column test run in nitrogen chamber. • Increased release of certain elements seen from residues under anaerobic conditions. • Different leaching tests produced results on two sides of regulatory threshold. - Abstract: Drinking water treatment residues (WTR), generated from the lime softening processes, are commonly reused or disposed of in a number of applications; these include use as a soil amendment or a subsurface fill. Recently questionsmore » were posed by the Florida regulatory community on whether lime WTR that contained a small percentage of other treatment additives could appropriately be characterized as lime WTR, in terms of total element content and leachability. A study was done using a broad range of leaching tests, including a framework of tests recently adopted by the United States-Environmental Protection Agency (EPA) and tests that were modified to account for scenario specific conditions, such as the presence of natural organic matter (NOM). The results of these additional leaching tests demonstrated that certain applications, including disposal in a water body with NOM or in placement anaerobic environment, did result in increased leaching of elements such as Fe, and that a site specific assessment should be conducted prior to using WTR in these types of applications. This study illustrates the importance of leaching test selection when attempting to provide an estimation of release in practice. Although leaching tests are just one component in a beneficial use assessment and other factors including aquifer and soil properties play a significant role in the outcome, leaching tests should be tailored to most appropriately represent the scenario or reuse application being evaluated.« less

CRITICAL CURVES AND CAUSTICS OF TRIPLE-LENS MODELS

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

Daněk, Kamil; Heyrovský, David, E-mail: kamil.danek@utf.mff.cuni.cz, E-mail: heyrovsky@utf.mff.cuni.cz

2015-06-10

Among the 25 planetary systems detected up to now by gravitational microlensing, there are two cases of a star with two planets, and two cases of a binary star with a planet. Other, yet undetected types of triple lenses include triple stars or stars with a planet with a moon. The analysis and interpretation of such events is hindered by the lack of understanding of essential characteristics of triple lenses, such as their critical curves and caustics. We present here analytical and numerical methods for mapping the critical-curve topology and caustic cusp number in the parameter space of n-point-mass lenses.more » We apply the methods to the analysis of four symmetric triple-lens models, and obtain altogether 9 different critical-curve topologies and 32 caustic structures. While these results include various generic types, they represent just a subset of all possible triple-lens critical curves and caustics. Using the analyzed models, we demonstrate interesting features of triple lenses that do not occur in two-point-mass lenses. We show an example of a lens that cannot be described by the Chang–Refsdal model in the wide limit. In the close limit we demonstrate unusual structures of primary and secondary caustic loops, and explain the conditions for their occurrence. In the planetary limit we find that the presence of a planet may lead to a whole sequence of additional caustic metamorphoses. We show that a pair of planets may change the structure of the primary caustic even when placed far from their resonant position at the Einstein radius.« less

Influence of solid-liquid separation method parameters employed in soil leaching tests on apparent metal concentration.

PubMed

Imoto, Yukari; Yasutaka, Tetsuo; Someya, Masayuki; Higashino, Kazuo

2018-05-15

Soil leaching tests are commonly used to evaluate the leachability of hazardous materials, such as heavy metals, from the soil. Batch leaching tests often enhance soil colloidal mobility and may require solid-liquid separation procedures to remove excess soil particles. However, batch leaching test results depend on particles that can pass through a 0.45μm membrane filter and are influenced by test parameters such as centrifugal intensity and filtration volume per filter. To evaluate these parameters, we conducted batch leaching experiments using metal-contaminated soils and focused on the centrifugal intensity and filtration volume per filter used in solid-liquid separation methods currently employed in standard leaching tests. Our experiments showed that both centrifugal intensity and filtration volume per filter affected the reproducibility of batch leaching tests for some soil types. The results demonstrated that metal concentrations in the filtrates significantly differed according to the centrifugal intensity when it was 3000 g for 2h or less. Increased filtration volume per filter led to significant decreases in filtrate metal concentrations when filter cakes formed during filtration. Comparison of the filtration tests using 0.10 and 0.45μm membrane filters showed statistically significant differences in turbidity and metal concentration. These findings suggest that colloidal particles were not adequately removed from the extract and contributed substantially to the apparent metal concentrations in the leaching test of soil containing colloidal metals. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

46 CFR Appendix I to Part 150 - Exceptions to the Chart

Code of Federal Regulations, 2013 CFR

2013-10-01

...). Triethylenetetramine (7). Sodium cresylate as Cresylate spent caustic (5) Methyl alcohol (20). Sodium dichromate, 70... (0) N-Methyl-2-pyrrolidone (9) Caustic potash, 50% or less (5) Isobutyl alcohol (20)Ethyl alcohol (20) Ethylene glycol (20) Isopropyl alcohol (20) Methyl alcohol (20) iso-Octyl alcohol (20) Caustic soda, 50% or...

46 CFR Appendix I to Part 150 - Exceptions to the Chart

Code of Federal Regulations, 2014 CFR

2014-10-01

...). Triethylenetetramine (7). Sodium cresylate as Cresylate spent caustic (5) Methyl alcohol (20). Sodium dichromate, 70...-pyrrolidone (9) Caustic potash, 50% or less (5) Isobutyl alcohol (20)Ethyl alcohol (20) Ethylene glycol (20) Isopropyl alcohol (20) Methyl alcohol (20) iso-Octyl alcohol (20) Caustic soda, 50% or less (5) Butyl...

16 CFR 1500.129 - Substances named in the Federal Caustic Poison Act.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Poison Act. 1500.129 Section 1500.129 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL... REGULATIONS § 1500.129 Substances named in the Federal Caustic Poison Act. The Commission finds that for those substances covered by the Federal Caustic Poison Act (44 Stat. 1406), the requirements of section 2(p)(1) of...

16 CFR 1500.129 - Substances named in the Federal Caustic Poison Act.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Poison Act. 1500.129 Section 1500.129 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL... REGULATIONS § 1500.129 Substances named in the Federal Caustic Poison Act. The Commission finds that for those substances covered by the Federal Caustic Poison Act (44 Stat. 1406), the requirements of section 2(p)(1) of...

16 CFR 1500.129 - Substances named in the Federal Caustic Poison Act.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Poison Act. 1500.129 Section 1500.129 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL... REGULATIONS § 1500.129 Substances named in the Federal Caustic Poison Act. The Commission finds that for those substances covered by the Federal Caustic Poison Act (44 Stat. 1406), the requirements of section 2(p)(1) of...

16 CFR § 1500.129 - Substances named in the Federal Caustic Poison Act.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Poison Act. § 1500.129 Section § 1500.129 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION... ENFORCEMENT REGULATIONS § 1500.129 Substances named in the Federal Caustic Poison Act. The Commission finds that for those substances covered by the Federal Caustic Poison Act (44 Stat. 1406), the requirements...

Leaching assessment of road materials containing primary lead and zinc slags.

PubMed

Barna, R; Moszkowicz, P; Gervais, C

2004-01-01

Characterisation of the leaching behaviour of waste-containing materials is a crucial step in the environmental assessment for reuse scenarios. In our research we applied the multi-step European methodology ENV 12-920 to the leaching assessment of road materials containing metallurgical slag. A Zn slag from an imperial smelting furnace (ISF) and a Pb slag from a lead blast furnace (LBF) are investigated. The two slags contain up to 11.2 wt% of lead and 3.5 wt% of zinc and were introduced as a partial substitute for sand in two road materials, namely sand-cement and sand-bitumen. At the laboratory scale, a leaching assessment was performed first through batch equilibrium leaching tests. Second, the release rate of the contaminants was evaluated using saturated leaching tests on monolithic material. Third, laboratory tests were conducted on monolithic samples under intermittent wetting conditions. Pilot-scale tests were conducted for field testing of intermittent wetting conditions. The results show that the release of Pb and Zn from the materials in a saturated scenario was controlled by the pH of the leachates. For the intermittent wetting conditions, an additional factor, blocking of the pores by precipitation during the drying phase is proposed. Pilot-scale leaching behaviour only partially matched with the laboratory-scale test results: new mass transfer mechanisms and adapted laboratory leaching tests are discussed.

Semi-dynamic leaching tests of nickel containing wastes stabilized/solidified with magnesium potassium phosphate cements.

PubMed

Torras, Josep; Buj, Irene; Rovira, Miquel; de Pablo, Joan

2011-02-28

Herein is presented a study on the long-term leaching behaviour of nickel containing wastes stabilized/solidified with magnesium potassium phosphate cements. Two different semi-dynamic leaching tests were carried out on monolithic materials: ANS 16.1 test with liquid-to-solid ratio (L/S) of 10 dm(3) kg(-1) and increasing renewal times, and ASTM C1308 test with liquid-to-solid ratio (L/S) of 100 dm(3) kg(-1) and constant renewal time of 1 day. ASTM C1308 provides a lower degree of saturation of the leachant with respect to the leached material. The effectiveness of magnesium potassium phosphate cements for the inertization of nickel was proved. XRD analyses showed the presence of bobierrite on the monolith's surface after the leaching test, which had not been detected prior to the leaching test. In addition, the calculated cumulative release of the main components of the stabilization matrix (Mg(2+), total P and K(+)) was represented versus time in logarithmic scale and it was determined if the leaching mechanism corresponds to diffusion. Potassium is released by diffusion, while total phosphorous and magnesium show dissolution. Magnesium release in ANS 16.1 is slowed down because of saturation of the leachant. Experimental results demonstrate the importance of L/S ratio and renewal times in semi-dynamic leaching tests. Copyright © 2010 Elsevier B.V. All rights reserved.

Microbial oxidation of mixtures of methylmercaptan and hydrogen sulfide.

PubMed

Subramaniyan, A; Kolhatkar, R; Sublette, K L; Beitle, R

1998-01-01

Refinery spent-sulfidic caustic, containing only inorganic sulfides, has previously been shown to be amenable to biotreatment with Thiobacillus denitrificans strain F with complete oxidation of sulfides to sulfate. However, many spent caustics contain mercaptans that cannot be metabolized by this strict autotroph. An aerobic enrichment culture was developed from mixed Thiobacilli and activated sludge that was capable of simultaneous oxidation of inorganic sulfide and mercaptans using hydrogen sulfide (H2S) and methylmercaptan (MeSH) gas feeds used to simulate the inorganic and organic sulfur of a spent-sulfidic caustic. The enrichment culture was also capable of biotreatment of an actual mercaptan-containing, spent-sulfidic caustic but at lower rates than predicted by operation on MeSH and H2S fed to the culture in the gas phase, indicating that the caustic contained other inhibitory components.

Spent caustic oxidation using electro-generated Fenton's reagent in a batch reactor.

PubMed

Rodriguez, Nicolas; Hansen, Henrik K; Nunez, Patricio; Guzman, Jaime

2008-07-01

This work shows the results of four Electro-Fenton laboratory tests to reduce the chemical oxygen demand (COD) in spent caustic solutions. The treatment consisted of (i) a pH reduction followed by (ii) an Electro-Fenton process, which was analyzed in this work. The Fenton's reagent was produced in a specially designed reactor, where the waste stream flowed through a labyrinth made by ferrous plates. These plates acted as sacrificial anodes-releasing Fe(2 +) cations to the solution, where H(2)O(2) was also added. The Electro-Fenton process was analyzed varying the ferrous ion concentration ([Fe(+ 2)]), the spent caustic's initial temperature and the initial pH. Close to 95% removal of COD (from 8800 mg L(- 1)) was achieved at a pH of 4, a temperature of 40 degrees C and 100 mg L(- 1) of Fe(+ 2) (applying 1 A). Two models were considered to simulate the behavior of the reactor considering (i) axial dispersion and (ii) kinetic rate, respectively. The model that was based on kinetics, proved to be the slightly closest fit to the experimental values.

Impacts of road salts on leaching behavior of lead contaminated soil.

PubMed

Wu, Jingjing; Kim, Hwidong

2017-02-15

Research was conducted to explore the effects of road salts on lead leaching from lead contaminated soil samples that were collected in an old residence area in Erie, PA. The synthetic precipitate leaching procedure (SPLP) test was employed to evaluate lead leaching from one of the lead contaminated soils in the presence of various levels of road salts (5%, 10%, 20%, 30% and 40%). The results of the leaching test showed that lead leaching dramatically increased as the road salt content increased as a result of the formation of lead-chloride complexes, but different lead leaching patterns were observed in the presence of NaCl- and CaCl 2 -based road salts at a high content of road salts (>20%). Additional leaching tests that include 30% road salts and different soil samples showed a variety of leaching patterns by soil samples. The sequential extraction of each soil sample showed that a high fraction of organic matter bound lead was associated with lead contamination. The higher the fraction of organic matter bound lead contained in soil, the greater the effects of calcium on reducing lead leaching, observations showed. Copyright © 2016 Elsevier B.V. All rights reserved.

Implementation of the Leaching Environmental Assessment ...

EPA Pesticide Factsheets

New leaching tests are available in the U.S. for developing more accurate source terms for use in fate and transport models. For beneficial use or disposal, the use of the leaching environmental assessment framework (LEAF) will provide leaching results that reflect field conditions reflecting either use of disposal of the material or waste. To provide overview of the implementation of new leaching tests for presentation at the MEGA symposium which is for the coal-fired power industry

Leach test of cladding removal waste grout using Hanford groundwater

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

Serne, R.J.; Martin, W.J.; Legore, V.L.

1995-09-01

This report describes laboratory experiments performed during 1986-1990 designed to produce empirical leach rate data for cladding removal waste (CRW) grout. At the completion of the laboratory work, funding was not available for report completion, and only now during final grout closeout activities is the report published. The leach rates serve as inputs to computer codes used in assessing the potential risk from the migration of waste species from disposed grout. This report discusses chemical analyses conducted on samples of CRW grout, and the results of geochemical computer code calculations that help identify mechanisms involved in the leaching process. Themore » semi-infinite solid diffusion model was selected as the most representative model for describing leaching of grouts. The use of this model with empirically derived leach constants yields conservative predictions of waste release rates, provided no significant changes occur in the grout leach processes over long time periods. The test methods included three types of leach tests--the American Nuclear Society (ANS) 16.1 intermittent solution exchange test, a static leach test, and a once-through flow column test. The synthetic CRW used in the tests was prepared in five batches using simulated liquid waste spiked with several radionuclides: iodine ({sup 125}I), carbon ({sup 14}C), technetium ({sup 99}Tc), cesium ({sup 137}Cs), strontium ({sup 85}Sr), americium ({sup 241}Am), and plutonium ({sup 238}Pu). The grout was formed by mixing the simulated liquid waste with dry blend containing Type I and Type II Portland cement, class F fly ash, Indian Red Pottery clay, and calcium hydroxide. The mixture was allowed to set and cure at room temperature in closed containers for at least 46 days before it was tested.« less

Hydrogen peroxide and caustic soda: Dancing with a dragon while bleaching

Treesearch

Peter W. Hart; Carl Houtman; Kolby Hirth

2013-01-01

When hydrogen peroxide is mixed with caustic soda, an auto-accelerating reaction can lead to generation of significant amounts of heat and oxygen. On the basis of experiments using typical pulp mill process concentration and temperatures, a relatively simple kinetic model has been developed. Evaluation of these model results reveals that hydrogen peroxide-caustic soda...

16 CFR 1500.129 - Substances named in the Federal Caustic Poison Act.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Commission therefore finds that for the following substances, and at the following concentrations, the word... REGULATIONS § 1500.129 Substances named in the Federal Caustic Poison Act. The Commission finds that for those... Caustic Poison Act, were required to bear the signal word “poison.” The Commission concludes that the lack...

The leaching of lead from lead-based paint in landfill environments.

PubMed

Wadanambi, Lakmini; Dubey, Brajesh; Townsend, Timothy

2008-08-30

Lead leaching from lead-based paint (LBP) was examined using standardized laboratory protocols and tests with leachate from actual and simulated landfill environments. Two different LBP samples were tested; leaching solutions included leachates from three municipal solid waste (MSW) landfills and three construction and demolition (C&D) debris landfills. The toxicity characteristic leaching procedure (TCLP) and the synthetic precipitation leaching procedure (SPLP) were also performed. Lead concentrations were many times higher using the TCLP compared to the SPLP and the landfill leachates. No significant difference (alpha=0.05) was observed in leached lead concentrations from the MSW landfill and C&D debris landfill leachates. The impact of other building materials present in LBP debris on lead leaching was examined by testing mixtures of LBP (2%) and different building materials (98%; steel, wood, drywall, concrete). The type of substrate present impacted lead leaching results, with concrete demonstrating the most dramatic impact; the lowest lead concentrations were measured in the presence of concrete under both TCLP and SPLP extractions.

Hazardous properties of paint residues from the furniture industry.

PubMed

Vaajasaari, Kati; Kulovaara, Maaret; Joutti, Anneli; Schultz, Eija; Soljamo, Kari

2004-01-30

The objective of this study was to screen nine excess paint residues for environmental hazard and to evaluate their disposability in a non-hazardous or hazardous-waste landfill. These residues were produced in the process of spray-painting furniture. Residues were classified according to their leaching and ecotoxicological properties. Leaching properties were determined with the European standard SFS-EN 12457-2 leaching-test. The toxicity of the leaching-test eluates was measured with plant-, bacteria- and enzyme-inhibition bioassays. Total organic carbon, formaldehyde and solvent concentrations in the solid wastes and in the leaching-test eluates were analysed. It seemed likely that leached formaldehyde caused very high acute toxicity in leaching-test eluates of the dry-booth residues. This hypothesis was based on the fact that the formaldehyde concentrations in the leaching-test eluates of the dry-booth residues were 62-75 times higher than the EC50 value reported in the literature for formaldehyde. The results of the water-curtain booth residues showed that the samples with the highest TOC and aromatic solvent concentrations were also the most toxic. The studied excess paint residues were complex organic mixtures and contained large amounts of compounds not identifiable from chemical data. Therefore, the evaluation of the hazard based solely on available chemical data is unlikely to be sufficient, as evidenced by our study. Our results show that harmful compounds remain in the solid waste and the toxicity results of their leaching-test eluates show that toxicity may leach from residues in contact with water at landfill sites. They also confirm the benefit of combining chemical and ecotoxicological assays in assessing the potential environmental hazard of complex organic mixtures found in wastes. Copyright 2003 Elsevier B.V.

Small-scale and large-scale testing of photo-electrochemically activated leaching technology in Aprelkovo and Delmachik Mines

NASA Astrophysics Data System (ADS)

Sekisov, AG; Lavrov, AYu; Rubtsov, YuI

2017-02-01

The paper gives a description of tests and trials of the technology of heap gold leaching from rebellious ore in Aprelkovo and Delmachik Mines. Efficiency of leaching flowsheets with the stage-wise use of activated solutions of different reagents, including active forms of oxygen, is evaluated. Carbonate-peroxide solutions are used at the first stage of leaching to oxidize sulfide and sulfide-arsenide ore minerals to recover iron and copper from them. The second stage leaching uses active cyanide solutions to leach encapsulated and disperse gold and silver.

OGLE-2016-BLG-1003: First Resolved Caustic-crossing Binary-source Event Discovered by Second-generation Microlensing Surveys

NASA Astrophysics Data System (ADS)

Jung, Y. K.; Udalski, A.; Bond, I. A.; Yee, J. C.; Gould, A.; Han, C.; Albrow, M. D.; Lee, C.-U.; Kim, S.-L.; Hwang, K.-H.; Chung, S.-J.; Ryu, Y.-H.; Shin, I.-G.; Zhu, W.; Cha, S.-M.; Kim, D.-J.; Lee, Y.; Park, B.-G.; Kim, H.-W.; Pogge, R. W.; KMTNet Collaboration; Skowron, J.; Szymański, M. K.; Poleski, R.; Mróz, P.; Kozłowski, S.; Pietrukowicz, P.; Soszyński, I.; Ulaczyk, K.; Pawlak, M.; OGLE Collaboration; Abe, F.; Bennett, D. P.; Barry, R.; Sumi, T.; Asakura, Y.; Bhattacharya, A.; Donachie, M.; Fukui, A.; Hirao, Y.; Itow, Y.; Koshimoto, N.; Li, M. C. A.; Ling, C. H.; Masuda, K.; Matsubara, Y.; Muraki, Y.; Nagakane, M.; Rattenbury, N. J.; Evans, P.; Sharan, A.; Sullivan, D. J.; Suzuki, D.; Tristram, P. J.; Yamada, T.; Yamada, T.; Yonehara, A.; MOA Collaboration

2017-06-01

We report the analysis of the first resolved caustic-crossing binary-source microlensing event OGLE-2016-BLG-1003. The event is densely covered by round-the-clock observations of three surveys. The light curve is characterized by two nested caustic-crossing features, which is unusual for typical caustic-crossing perturbations. From the modeling of the light curve, we find that the anomaly is produced by a binary source passing over a caustic formed by a binary lens. The result proves the importance of high-cadence and continuous observations, and the capability of second-generation microlensing experiments to identify such complex perturbations that are previously unknown. However, the result also raises the issues of the limitations of current analysis techniques for understanding lens systems beyond two masses and of determining the appropriate multiband observing strategy of survey experiments.

NEXT GENERATION LEACHING TESTS FOR EVALUATING ...

EPA Pesticide Factsheets

In the U.S. as in other countries, there is increased interest in using industrial by-products as alternative or secondary materials, helping to conserve virgin or raw materials. The LEAF and associated test methods are being used to develop the source term for leaching or any inorganic constituents of potential concern (COPC) in determining what is environmentally acceptable. The leaching test methods include batch equilibrium, percolation column and semi-dynamic mass transport tests for monolithic and compacted granular materials. By testing over a range of values for pH, liquid/solid ratio, and physical form of the material, this approach allows one data set to be used to evaluate a range of management scenarios for a material, representing different environmental conditions (e.g., disposal or beneficial use). The results from these tests may be interpreted individually or integrated to identify a solid material’s characteristic leaching behavior. Furthermore the LEAF approach provides the ability to make meaningful comparisons of leaching between similar and dissimilar materials from national and worldwide origins. To present EPA's research under SHC to implement validated leaching tests referred to as the Leaching Environmental Assessment Framework (LEAF). The primary focus will be on the guidance for implementation of LEAF describing three case studies for developing source terms for evaluating inorganic constituents.

Chemical Discovery as Belief Revision.

DTIC Science & Technology

1986-09-30

in order to explain conflicting experimental results. For example, Gay- Lussac and Thenard claimed that potassium con- sisted of caustic-potash and...hydrogen, while Davy observed that caustic-potash decomposed into potassium and oxygen. To support their view, Gay- Lussac and Thenard proposed that...Potash and Potassium We touched earlier on the disagreement between Davy and fellow chemists Gay- Lussac and Thenard concerning caustic-potash and

Evaluation of the leaching behavior of incineration bottom ash using seawater: A comparison with standard leaching tests.

PubMed

Lin, Wenlin Yvonne; Heng, Kim Soon; Nguyen, Minh Quan; Ho, Jin Rui Ivan; Mohamed Noh, Omar Ahmad Bin; Zhou, Xue Dong; Liu, Alec; Ren, Fei; Wang, Jing-Yuan

2017-04-01

Batch and column tests were conducted on untreated incineration bottom ash (IBA) samples from two incineration plants in Singapore, using seawater as the leachant. The main objective of this study was to investigate the change in the leaching behavior of certain elements (i.e. As, Cd, Cr, Cu, Ni, Pb, Sb, Se and Zn) when IBA comes into contact with seawater. Such an investigation using seawater as leachant was not commonly carried out when investigating leaching behavior in IBA. The leaching tests were then carried out on the same IBA samples using DI water, as a comparison. Lower level of leaching was observed for Pb and Zn when seawater was used as the leachant. Cr and Sb showed significant cumulative release at Liquid-to-Solids (L/S) ratio 5 in the seawater column leaching. The influence of Dissolved Organic Carbon (DOC) on Cu leaching seems to decrease after L/S 2 when using seawater in the column test. Although the leaching behavior of IBA was affected when seawater was used, for the column test, there was no significant difference during the initial release when compared to DI water. The initial L/S fractions collected were important as the low L/S ratios represent the pore water concentration and the maximum output in an actual application. The results from this study would be useful for the future study on using IBA in marine applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biological treatment of toxic petroleum spent caustic in fluidized bed bioreactor using immobilized cells of Thiobacillus RAI01.

PubMed

Potumarthi, Ravichandra; Mugeraya, Gopal; Jetty, Annapurna

2008-12-01

In the present studies, newly isolated Thiobacillus sp was used for the treatment of synthetic spent sulfide caustic in a laboratory-scale fluidized bed bioreactor. The sulfide oxidation was tested using Ca-alginate immobilized Thiobacillus sp. Initially, response surface methodology was applied for the optimization of four parameters to check the sulfide oxidation efficiency in batch mode. Further, reactor was operated in continuous mode for 51 days at different sulfide loading rates and retention times to test the sulfide oxidation and sulfate and thiosulfate formation. Sulfide conversions in the range of 90-98% were obtained at almost all sulfide loading rates and hydraulic retention times. However, increased loading rates resulted in lower sulfide oxidation capacity. All the experiments were conducted at constant pH of around 6 and temperature of 30 +/- 5 degrees C.

Microlensing of Extremely Magnified Stars near Caustics of Galaxy Clusters

NASA Astrophysics Data System (ADS)

Venumadhav, Tejaswi; Dai, Liang; Miralda-Escudé, Jordi

2017-11-01

Recent observations of lensed galaxies at cosmological distances have detected individual stars that are extremely magnified when crossing the caustics of lensing clusters. In idealized cluster lenses with smooth mass distributions, two images of a star of radius R approaching a caustic brighten as {t}-1/2 and reach a peak magnification ˜ {10}6{(10{R}⊙ /R)}1/2 before merging on the critical curve. We show that a mass fraction ({κ }\\star ≳ {10}-4.5) in microlenses inevitably disrupts the smooth caustic into a network of corrugated microcaustics and produces light curves with numerous peaks. Using analytical calculations and numerical simulations, we derive the characteristic width of the network, caustic-crossing frequencies, and peak magnifications. For the lens parameters of a recent detection and a population of intracluster stars with {κ }\\star ˜ 0.01, we find a source-plane width of ˜ 20 {pc} for the caustic network, which spans 0.2 {arcsec} on the image plane. A source star takes ˜ 2× {10}4 years to cross this width, with a total of ˜ 6× {10}4 crossings, each one lasting for ˜ 5 {hr} (R/10 {R}⊙ ) with typical peak magnifications of ˜ {10}4 {(R/10{R}⊙ )}-1/2. The exquisite sensitivity of caustic-crossing events to the granularity of the lens-mass distribution makes them ideal probes of dark matter components, such as compact halo objects and ultralight axion dark matter.

Adsorptive conversion of nitrogen dioxide from etching vent gases over activated carbon.

PubMed

Fang, Mei-Ling; Wu, Ching-Yi; Chou, Ming-Shean

2018-04-13

Some metal etching operations emit limited flow rates of waste gases with reddish-brown NO 2 fume, which may cause visual and acidic-odor complaints, as well as negative health effects. In this study, tests were performed by passing caustic-treated waste gases vented from Al-etching operations through columns packed either with virgin or regenerated granular activated carbon (GAC) to test their adsorptive conversion performance of NO 2 in the gases. The gases contained 5-55 ppm NO 2 and acetic and nitric acids of below 3 ppm. Exhausted carbon was regenerated by scrubbing it with caustic solution and water, and dried for further adsorption tests. Results indicate that with an (empty bed residence time (EBRT) of 0.15 sec for the gas through the GAC-packed space, around 60% of the influent NO 2 of 54 ppm could be removed, and 47% of the removed NO 2 was converted by and desorbed from the carbon as NO. GAC used in the present study could be regenerated at least twice to restore its capacity for NO 2 adsorption. Within EBRTs of 0.076-0.18 sec, the adsorptive conversion capacity was linearly varied with EBRT. In practice, with an EBRT of 0.20 sec, a conversion capacity of 0.80 kg NO 2 (kg GAC) -1 with an influent NO 2 of 40 ppm can be used as a basis for system design. Some metal etching operations emit waste gases with reddish-brown (yellow when diluted) NO 2 fume which may cause visual and acidic-odor complaints, as well as negative health effects. This study provides a simple process for the adsorptive conversion of NO 2 in caustic-treated waste gases vented from metal-etching operations through a GAC column. With an EBRT of 0.20 sec, a conversion capacity of 0.80 kg NO 2 (kg GAC) -1 with an influent NO 2 of 40 ppm can be used as a basis for system design. Saturated GAC can be regenerated at least twice by simply scrubbing it with aqueous caustic solution.

Polymer Claw: Instant Underwater Adhesive

DTIC Science & Technology

2012-03-23

technology is the use of pressure sensitive microcapsules , which release reactive amine crosslinkers into an adhesive putty when pressed against the...PROIECT GOALS AND OBIECTIVES 2 2 KEY ACCOMPLISHMENTS 2 3.1 KICKOFF MEETING 3 3.2 AMINE MICROENCAPSULATION 3 3.3 CAUSTIC CLEANING AGENT 5 3.4...caustic, and the abrasive brush. We successfully synthesized amine-filled microcapsules and a dry mixture of caustic ingredients that only activate when

LEACHING OF METALS FROM MINERAL PROCESSING WASTE

EPA Science Inventory

The purpose of this project is to test the leaching of Mineral processing Waste (MPW) contaminated with heavy metals using scientifically defendable leaching tests other than TCLP. Past experience and literature have shown that TCLP underestiates the levels of metals such as oxoa...

LEACHING OF METALS FROM MINERAL PROCESSING WASTE

EPA Science Inventory

The purpose of this project is to test the leaching of Mineral Processing Waste (MPW) contaminated with heavy metals using scientifically defendable leaching tests other than TCLP. Past experience and literature have shown that TCLP underestimates the levels of metals such as oxo...

Final Work Plan for CO2 Sparging Proof of Concept Test, LCP Chemical Site

EPA Pesticide Factsheets

September 11, 2012 plan to address concerns on a pilot test of carbon dioxide sparging to neutralize pH and reduce the density of the Caustic Brine Pool (CBP) at the LCP Chemicals Superfund Site, GA. Region ID: 04 DocID: 10903388, DocDate: 09-11-2012

Results from Alloy 600 And Alloy 690 Caustic SCC Model Boiler Tests

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

Miller, Frederick D.; Thomas, Larry E.

2009-08-03

A versatile model boiler test methodology was developed and used to compare caustic stress corrosion cracking (SCC) of mill annealed Alloy 600 and thermally treated Alloy 690. The model boiler included simulated crevice devices that efficiently and consistently concentrated Na2CO3, resulting in volatilization of CO2 with the steam and concentration of NaOH at the tube surfaces. The test methodology also included variation in tube stress, either produced by the primary to secondary side pressure differential, or by a novel method that reproducibly yields a higher stress condition on the tube. The significant effect of residual stress on tube SCC wasmore » also considered. SCC of both Alloy 600 and Alloy 690 were evaluated as a function of temperature and stress. Analytical transmission electron microscopy (ATEM) evaluations of the cracks and the grain boundaries ahead of the cracks were performed, providing insight into the SCC mechanism. This model boiler test methodology may be applicable to a range of bulkwater secondary chemistries that concentrate to produce aggressive crevice environments.« less

Comparison of leaching characteristics of heavy metals in APC residue from an MSW incinerator using various extraction methods.

PubMed

Chiang, Kung-Yuh; Tsai, Chen-Chiu; Wang, Kuen-Sheng

2009-01-01

This study investigates four extraction methods (water extraction, toxicity characteristics leaching procedure (TCLP), modified TCLP with pH control, and sequential chemical extraction (SCE)), each representing different liquid-to-solid (L/S) ratios, pH controls, and types of leachant, and their effects on the leaching concentration of heavy metals in municipal solid waste (MSW) incinerator air pollution control (APC) residue. The results indicated that for extraction with distilled water, the heavy metal leaching concentration (mg/l) decreased with L/S ratio, but the amount of heavy metal released (AHMR), defined as the leached amount of heavy metals to the weight of the tested sample (mg/kg), increased with an increase in L/S ratio, in the range of 2-100. The results also showed that both the leaching concentration and the amount of released metals were strongly pH-dependent in the TCLP and modified TCLP tests. In the case of pHs lower than 6.5, the leaching concentrations of Cd, Pb, Cu, Zn, and Cr decreased with an increase in pH. As pH increased higher than 6.5, Cr and Zn were almost insoluble. Meanwhile, Cd and Cu also showed a similar trend but at pHs of 8.5 and 7.5, respectively. Due to the nature of amphoteric elements, in the case of pHs higher than 7, the Pb leaching concentration increased with increasing pH. In modified TCLP tests with the pH value controlled at the same level as in the SCE test, the heavy metal speciation approached the extractable carbonate bound fraction by the SCE. Both amounts of targeted metals leached from the SCE and modified TCLP tests were much higher than those for the regular TCLP and water extraction tests.

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

Serne, R. Jeffrey; Westsik, Joseph H.; Williams, Benjamin D.

This report describes the results from long-term laboratory leach tests performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate the release of key constituents from monoliths of Cast Stone prepared with four simulated low-activity waste (LAW) liquid waste streams. Specific objectives of the Cast Stone long-term leach tests described in this report focused on four activities: 1. Extending the leaching times for selected ongoing EPA-1315 tests on monoliths made with LAW simulants beyond the conventional 63-day time period up to 609 days reported herein (with some tests continuing that will be documented later) inmore » an effort to evaluate long-term leaching properties of Cast Stone to support future performance assessment activities. 2. Starting new EPA-1315 leach tests on archived Cast Stone monoliths made with four LAW simulants using two leachants (deionized water [DIW] and simulated Hanford Integrated Disposal Facility (IDF) Site vadose zone pore water [VZP]). 3. Evaluating the impacts of varying the iodide loading (starting iodide concentrations) in one LAW simulant (7.8 M Na Hanford Tank Waste Operations Simulator (HTWOS) Average) by manufacturing new Cast Stone monoliths and repeating the EPA-1315 leach tests using DIW and the VZP leachants. 4. Evaluating the impacts of using a non-pertechnetate form of Tc that is present in some Hanford tanks. In this activity one LAW simulant (7.8 M Na HTWOS Average) was spiked with a Tc(I)-tricarbonyl gluconate species and then solidified into Cast Stone monoliths. Cured monoliths were leached using the EPA-1315 leach protocol with DIW and VZP. The leach results for the Tc-Gluconate Cast Stone monoliths were compared to Cast Stone monoliths pertechnetate.« less

The point-characteristic function, wavefronts, and caustic of a spherical wave refracted by an arbitrary smooth surface.

PubMed

Marciano-Melchor, Magdalena; Navarro-Morales, Esperanza; Román-Hernández, Edwin; Santiago-Santiago, José Guadalupe; Silva-Ortigoza, Gilberto; Silva-Ortigoza, Ramón; Suárez-Xique, Román

2012-06-01

The aim of this paper is to obtain expressions for the k-function, the wavefront train, and the caustic associated with the light rays refracted by an arbitrary smooth surface after being emitted by a point light source located at an arbitrary position in a three-dimensional homogeneous optical medium. The general results are applied to a parabolic refracting surface. For this case, we find that when the point light source is off the optical axis, the caustic locally has singularities of the hyperbolic umbilic type, while the refracted wavefront, at the caustic region, locally has singularities of the cusp ridge and swallowtail types.

Direct Causticizing for Black Liquor Gasification in a Circulating Fluidized Bed

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

Scott Sinquefield; Xiaoyan Zeng, Alan Ball

2010-03-02

Gasification of black liquor (BLG) has distinct advantages over direct combustion in Tomlinson recovery boilers. In this project we seek to resolve causticizing issues in order to make pressurized BLG even more efficient and cost-effective. One advantage of BLG is that the inherent partial separation of sulfur and sodium during gasification lends itself to the use of proven high yield variants to conventional kraft pulping which require just such a separation. Processes such as polysulfide, split sulfidity, ASAQ, and MSSAQ can increase pulp yield from 1% to 10% over conventional kraft but require varying degrees of sulfur/sodium separation, which requiresmore » additional [and costly] processing in a conventional Tomlinson recovery process. However during gasification, the sulfur is partitioned between the gas and smelt phases, while the sodium all leaves in the smelt; thus creating the opportunity to produce sulfur-rich and sulfur-lean white liquors for specialty pulping processes. A second major incentive of BLG is the production of a combustible product gas, rich in H2 and CO. This product gas (a.k.a. “syngas”) can be used in gas turbines for combined cycle power generation (which is twice as efficient as the steam cycle alone), or it can be used as a precursor to form liquid fuels, such as dimethyl ether or Fischer Tropsh diesel. There is drawback to BLG, which has the potential to become a third major incentive if this work is successful. The causticizing load is greater for gasification of black liquor than for combustion in a Tomlinson boiler. So implementing BLG in an existing mill would require costly increases to the causticizing capacity. In situ causticizing [within the gasifier] would handle the entire causticizing load and therefore eliminate the lime cycle entirely. Previous work by the author and others has shown that titanate direct causticizing (i.e. in situ) works quite well for high-temperature BLG (950°C), but was limited to pressures below about 5 bar. It is desirable however to operate BLG at 20-30 bar for efficiency reasons related to either firing the syngas in a turbine, or catalytically forming liquid fuels. This work focused on achieving high direct causticizing yields at 20 bars pressure. The titanate direct causticizing reactions are inhibited by CO2. Previous work has shown that the partial pressure of CO2 should be kept below about 0.5 bar in order for the process to work. This translates to a total reactor pressure limit of about 5 bar for airblown BLG, and only 2 bar for O2-blown BLG. In this work a process was developed in which the CO2 partial pressure could be manipulated to a level under 0.5 bar with the total system pressure at 10 bar during O2-blown BLG. This fell short of our 20 bar goal but still represents a substantial increase in the pressure limit. A material and energy balance was performed, as well as first-pass economics based on capital and utilities costs. Compared to a reference case of using BLG with a conventional lime cycle [Larson, 2003], the IRR and NVP were estimated for further replacing the lime kiln with direct causticizing. The economics are strongly dependent on the price of lime kiln fuel. At $6/mmBTU the lime cycle is the clear choice. At $8/mmBTU the NPV is $10M with IRR of 17%. At $12/mmBTU the NPV is $45M with IRR of 36%. To further increase the total allowable pressure, the CO2 could be further decreased by further decreasing the temperature. Testing should be done at 750C. Also a small pilot should be built.« less

Evaluation of selected static methods used to estimate element mobility, acid-generating and acid-neutralizing potentials associated with geologically diverse mining wastes

USGS Publications Warehouse

Hageman, Philip L.; Seal, Robert R.; Diehl, Sharon F.; Piatak, Nadine M.; Lowers, Heather

2015-01-01

A comparison study of selected static leaching and acid–base accounting (ABA) methods using a mineralogically diverse set of 12 modern-style, metal mine waste samples was undertaken to understand the relative performance of the various tests. To complement this study, in-depth mineralogical studies were conducted in order to elucidate the relationships between sample mineralogy, weathering features, and leachate and ABA characteristics. In part one of the study, splits of the samples were leached using six commonly used leaching tests including paste pH, the U.S. Geological Survey (USGS) Field Leach Test (FLT) (both 5-min and 18-h agitation), the U.S. Environmental Protection Agency (USEPA) Method 1312 SPLP (both leachate pH 4.2 and leachate pH 5.0), and the USEPA Method 1311 TCLP (leachate pH 4.9). Leachate geochemical trends were compared in order to assess differences, if any, produced by the various leaching procedures. Results showed that the FLT (5-min agitation) was just as effective as the 18-h leaching tests in revealing the leachate geochemical characteristics of the samples. Leaching results also showed that the TCLP leaching test produces inconsistent results when compared to results produced from the other leaching tests. In part two of the study, the ABA was determined on splits of the samples using both well-established traditional static testing methods and a relatively quick, simplified net acid–base accounting (NABA) procedure. Results showed that the traditional methods, while time consuming, provide the most in-depth data on both the acid generating, and acid neutralizing tendencies of the samples. However, the simplified NABA method provided a relatively fast, effective estimation of the net acid–base account of the samples. Overall, this study showed that while most of the well-established methods are useful and effective, the use of a simplified leaching test and the NABA acid–base accounting method provide investigators fast, quantitative tools that can be used to provide rapid, reliable information about the leachability of metals and other constituents of concern, and the acid-generating potential of metal mining waste.

46 CFR Table 151.05 to Subpart 151... - Summary of Minimum Requirements

Code of Federal Regulations, 2011 CFR

2011-10-01

...% or more Phenol, see Phenol Cresylate spent caustic Atmos. Amb. III 1 i i 2 i Integral Gravity Open... spent caustic Crotonaldehyde Atmos. Amb. II 1 i i 2 i i Integral Gravity PV Restr. II G-1 NR Vent F Yes.... II G-2 NR Vent N Yes .50-73 NA NA G Caustic potash solution Atmos. Amb.Elev. III 1 i 2 i Integral...

46 CFR Table 151.05 to Subpart 151... - Summary of Minimum Requirements

Code of Federal Regulations, 2014 CFR

2014-10-01

...% or more Phenol, see Phenol Cresylate spent caustic Atmos. Amb. III 1 i i 2 i Integral Gravity Open... spent caustic Crotonaldehyde Atmos. Amb. II 1 i i 2 i i Integral Gravity PV Restr. II G-1 NR Vent F Yes.... II G-2 NR Vent N Yes .50-73 NA NA G Caustic potash solution Atmos. Amb.Elev. III 1 i 2 i Integral...

46 CFR Table 151.05 to Subpart 151... - Summary of Minimum Requirements

Code of Federal Regulations, 2013 CFR

2013-10-01

...% or more Phenol, see Phenol Cresylate spent caustic Atmos. Amb. III 1 i i 2 i Integral Gravity Open... spent caustic Crotonaldehyde Atmos. Amb. II 1 i i 2 i i Integral Gravity PV Restr. II G-1 NR Vent F Yes.... II G-2 NR Vent N Yes .50-73 NA NA G Caustic potash solution Atmos. Amb.Elev. III 1 i 2 i Integral...

46 CFR Table 151.05 to Subpart 151... - Summary of Minimum Requirements

Code of Federal Regulations, 2010 CFR

2010-10-01

..., see Phenol Cresylate spent caustic Atmos. Amb. III 1 i i 2 i Integral Gravity Open Open II G-1 NR Vent N No .50-73.55-1(b) NA NA G Cresylic acid, sodium salt solution, see Cresylate spent caustic.... II G-2 NR Vent N Yes .50-73 NA NA G Caustic potash solution Atmos. Amb.Elev. III 1 i 2 i Integral...

46 CFR Table 151.05 to Subpart 151... - Summary of Minimum Requirements

Code of Federal Regulations, 2012 CFR

2012-10-01

...% or more Phenol, see Phenol Cresylate spent caustic Atmos. Amb. III 1 i i 2 i Integral Gravity Open... spent caustic Crotonaldehyde Atmos. Amb. II 1 i i 2 i i Integral Gravity PV Restr. II G-1 NR Vent F Yes... G-2 NR Vent N Yes .50-73 NA NA G Caustic potash solution Atmos. Amb.Elev. III 1 i 2 i Integral...

Thermal treatment of stabilized air pollution control residues in a waste incinerator pilot plant. Part 2: Leaching characteristics of bottom ashes.

PubMed

Baun, Dorthe L; Christensen, Thomas H; Bergfeldt, Brita; Vehlow, Jürgen; Mogensen, Erhardt P B

2004-02-01

With the perspective of generating only one solid residue from waste incineration, co-feeding of municipal solid waste and air pollution control residues stabilized by the Ferrox process was investigated in the TAMARA pilot plant incinerator as described in Bergfeldt et al. (Waste Management Research, 22, 49-57, 2004). This paper reports on leaching from the combined bottom ashes. Batch leaching test, pH-static leaching tests, availability tests and column leaching tests were used to characterize the leaching properties. The leaching properties are key information in the context of reuse in construction or in landfilling of the combined residue. In general, the combined bottom ashes had leaching characteristics similar to the reference bottom ash, which contained no APC residue. However, As and Pb showed slightly elevated leaching from the combined bottom ashes, while Cr showed less leaching. The investigated combined bottom ashes had contents of metals comparable to what is expected at steady state after continuous co-feeding of APC residues. Only Cd and Pb were partly volatilized (30-40%) during the incineration process and thus the combined bottom ashes had lower contents of Cd and Pb than expected at steady state. Furthermore, a major loss of Hg was, not surprisingly, seen and co-feeding of Ferrox-products together with municipal solid waste will require dedicated removal of Hg in the flue gas to prevent a build up of Hg in the system. In spite of this, a combined single solid residue from waste incineration seems to be a significant environmental improvement to current technology.

Protective effects of dexpanthenol and y-27632 on stricture formation in a rat model of caustic esophageal injury.

PubMed

Ceylan, Haluk; Yapici, Sefa; Tutar, Ediz; Ceylan, Nurdan Ozlu; Tarakçıoğlu, Mehmet; Demiryurek, A Tuncay

2011-12-01

This experimental study was conducted to investigate the effect of dexpanthenol (converted in the body to pantothenic acid) and Y-27632 (a selective Rho-kinase inhibitor) on stricture formation after caustic (alkaline) esophageal injury in rats. Sixty male Wistar albino rats were randomly allocated into six groups. In group 1 (sham) the distal esophagus was isolated and cannulated but no caustic injury was induced. In all remaining groups, a caustic esophageal burn was induced with 50% sodium hydroxide solution for 90 s and drug treatment was given by daily intraperitoneal injection, beginning 24 h after injury and continuing for 21 d. In group 2 (controls), animals were treated with 0.9% saline; in groups 3 and 4, with 50 and 500 mg/kg/d of dexpanthenol, respectively; and in groups 5 and 6, with 0.3 and 3 mg/kg/d of Y-27632, respectively. Rats were sacrificed 22 d after caustic injury and the distal esophagus was isolated for histopathology and biochemical investigation. Stenosis index and collagen deposition scores were significantly lower in both the dexpanthenol and Y-27632 treated groups (P<0.05). Dexpanthenol and Y-27632 treatment markedly depressed esophageal tissue malondialdehyde and hydroxyproline levels. In this experimental model of caustic esophageal stricture, dexpanthenol and Y-27632 significantly attenuated esophageal stricture formation. These findings indicate that inhibition of Rho-kinase or dexpanthenol administration may offer novel therapeutic approaches in the treatment of caustic esophageal injury. Copyright © 2011 Elsevier Inc. All rights reserved.

A PLANETARY LENSING FEATURE IN CAUSTIC-CROSSING HIGH-MAGNIFICATION MICROLENSING EVENTS

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

Chung, Sun-Ju; Hwang, Kyu-Ha; Ryu, Yoon-Hyun

Current microlensing follow-up observations focus on high-magnification events because of the high efficiency of planet detection. However, central perturbations of high-magnification events caused by a planet can also be produced by a very close or a very wide binary companion, and the two kinds of central perturbations are not generally distinguished without time consuming detailed modeling (a planet-binary degeneracy). Hence, it is important to resolve the planet-binary degeneracy that occurs in high-magnification events. In this paper, we investigate caustic-crossing high-magnification events caused by a planet and a wide binary companion. From this investigation, we find that because of the differentmore » magnification excess patterns inside the central caustics induced by the planet and the binary companion, the light curves of the caustic-crossing planetary-lensing events exhibit a feature that is discriminated from those of the caustic-crossing binary-lensing events, and the feature can be used to immediately distinguish between the planetary and binary companions. The planetary-lensing feature appears in the interpeak region between the two peaks of the caustic-crossings. The structure of the interpeak region for the planetary-lensing events is smooth and convex or boxy, whereas the structure for the binary-lensing events is smooth and concave. We also investigate the effect of a finite background source star on the planetary-lensing feature in the caustic-crossing high-magnification events. From this, we find that the convex-shaped interpeak structure appears in a certain range that changes with the mass ratio of the planet to the planet-hosting star.« less

Speciation analysis and leaching behaviors of selected trace elements in spent SCR catalyst.

PubMed

Dai, Zejun; Wang, Lele; Tang, Hao; Sun, Zhijun; Liu, Wei; Sun, Yi; Su, Sheng; Hu, Song; Wang, Yi; Xu, Kai; Liu, Liang; Ling, Peng; Xiang, Jun

2018-09-01

This study investigated heavy metal chemical speciation and leaching behavior from a board-type spent selective catalytic reduction (SCR) catalyst containing high concentrations of vanadium, chromium, nickel, copper, zinc, and lead. A three-step sequential extraction method, standard toxicity characteristic leaching procedure (TCLP), and leaching characteristic tests have been performed. It was found that the mobility of six heavy metals in the spent SCR catalyst was significantly different. The mobility of the six heavy metals exhibited the following order: Ni > Zn > V > Cr > As > Cu. Meanwhile, TCLP test results revealed relatively high Zn and Cr leaching rate of 83.20% and 10.35%, respectively. It was found that leaching rate was positively correlated with available contents (sum of acid soluble, reducible and oxidizable fractions). Leaching characteristics tests indicated that pH substantially affected the leaching of these heavy metals. In particular, the leaching of Cr, Ni, Cu, and Zn was positively influenced by strong acid, while V and As were easily released in the presence of strong acid and strong alkali (pH < 3 or pH > 11). In terms of kinetics, the leaching of Cr, Ni, Cu, Zn, and As within the spent catalyst was dominated by erosion and dissolution processes, which were rapid reaction processes. V was released in large amounts within 1 h, but its leaching amount sharply decreased with time due to readsorption. Copyright © 2018 Elsevier Ltd. All rights reserved.

Long-term environmental impacts of building composites containing waste materials: Evaluation of the leaching protocols.

PubMed

Drinčić, Ana; Nikolić, Irena; Zuliani, Tea; Milačič, Radmila; Ščančar, Janez

2017-01-01

The NEN 7375 test has been proposed for evaluating the long-term environmental impacts caused by the release of contaminants from monolithic building and waste materials. Over a period of 64days, at specific points in time, the leaching solution (demineralised water) is replenished. By applying the NEN 7375 test, leaching of contaminants that is based mainly on diffusion is followed. In the present work, the results from modified leaching protocols were evaluated against those obtained by NEN 7375 test. In modified protocols, synthetic sea, surface and MilliQ water were used for the leaching of selected elements and chromate, molybdate and vanadate from compact and ground building composites (98% mixture of fly ash (80%) and cement (20%), and 2% of electric arc furnace (EAF) dust) over 6months. The leaching solutions were not replenished, imitating both the diffusion and the dissolution of contaminants. The data revealed larger extent of leaching when the leaching solution was not replenished. More extensive was also leaching from ground composites, which simulated the disintegration of the material over time. The composition of the leaching solution influenced the release of the matrix constituents from the composites and, consequently, the amount of elements and their chemical species. Synthetic sea and surface water used as leaching solutions, without replenishing, were found to be suitable to simulate the conditions when the building material is immersed in stagnant environmental waters. Copyright © 2016 Elsevier Ltd. All rights reserved.

TOXIC EXPOSURES IN CHILDREN INVOLVING LEGALLY AND ILLEGALLY COMMERCIALIZED HOUSEHOLD SANITIZERS

PubMed Central

Campos, Alessandra Marcuz de Souza; Bucaretchi, Fábio; Fernandes, Luciane Cristina Rodrigues; Fernandes, Carla Borrasca; de Capitani, Eduardo Mello; Beck, Ana Raquel Medeiros

2017-01-01

ABSTRACT Objectives: To analyze and to compare clinical repercussions of accidents involving legally and illegally commercialized household sanitizers in children under 7 years of age. Methods: A descriptive cross-sectional design was used to collect data from electronic database of a regional Poison Control Center during one year. Data were analyzed by means of descriptive non-parametric statistics and association tests. Results: The sample had 737 reported cases. Most of the accidents occurred with children under 3 years of age (median: 1 year of age; interquartile interval: 1-3 years of age), at home (92.9%), by ingestion (97.2%). Products involved were cleaning products with low toxicity and no caustic effects (38.9%); caustics (24.1%); hydrocarbons (19.3%); pesticides/rodenticides (16.6%), and other products (1.1%). Seventy accidents were due to exposures to illegal products, mainly caustics (n=47) and rodenticides (n=15). Among the 337 children presenting post-exposure clinical manifestations, the most frequent were vomiting (n=125), oral burns (n=74), cough (n=35), drooling (n=26), and abdominal pain (n=25). Clinical manifestations were significantly more frequent after illegal products exposure (55/70 versus 282/667, p<0.01). Nineteen children had to be hospitalized (caustics, n=17; illegal products, n=12; median time of hospitalization: 2 days), 22 were submitted to esophagogastroduodenoscopy (sodium hydroxide, n=14; illegal products, n=14); and 12 cases had endoscopic alterations (severe in 2). No deaths occurred. Conclusion: Toxic exposures owing to illegal household sanitizer products are associated with greater morbidity when compared with legal ones. PMID:28977311

Patients Admitted to Three Spanish Intensive Care Units for Poisoning: Type of Poisoning, Mortality, and Functioning of Prognostic Scores Commonly Used

PubMed Central

Banderas-Bravo, María Esther; Arias-Verdú, Maria Dolores; Macías-Guarasa, Ines; Castillo-Lorente, Encarnación; Pérez-Costillas, Lucia; Gutierrez-Rodriguez, Raquel; Quesada-García, Guillermo; Rivera-Fernández, Ricardo

2017-01-01

Objectives. To evaluate the gravity and mortality of those patients admitted to the intensive care unit for poisoning. Also, the applicability and predicted capacity of prognostic scales most frequently used in ICU must be evaluated. Methods. Multicentre study between 2008 and 2013 on all patients admitted for poisoning. Results. The results are from 119 patients. The causes of poisoning were medication, 92 patients (77.3%), caustics, 11 (9.2%), and alcohol, 20 (16,8%). 78.3% attempted suicides. Mean age was 44.42 ± 13.85 years. 72.5% had a Glasgow Coma Scale (GCS) ≤8 points. The ICU mortality was 5.9% and the hospital mortality was 6.7%. The mortality from caustic poisoning was 54.5%, and it was 1.9% for noncaustic poisoning (p < 0.001). After adjusting for SAPS-3 (OR: 1.19 (1.02–1.39)) the mortality of patients who had ingested caustics was far higher than the rest (OR: 560.34 (11.64–26973.83)). There was considerable discrepancy between mortality predicted by SAPS-3 (26.8%) and observed (6.7%) (Hosmer-Lemeshow test: H = 35.10; p < 0.001). The APACHE-II (7,57%) and APACHE-III (8,15%) were no discrepancies. Conclusions. Admission to ICU for poisoning is rare in our country. Medication is the most frequent cause, but mortality of caustic poisoning is higher. APACHE-II and APACHE-III provide adequate predictions about mortality, while SAPS-3 tends to overestimate. PMID:28459061

Inhibition of the acetoclastic methanogenic activity by phenol and alkyl phenols.

PubMed

Olguin-Lora, P; Puig-Grajales, L; Razo-Flores, E

2003-08-01

Chemical and petrochemical industries are important sources of aromatic pollutants. Petrochemical processes like caustic washing of middle distillates produce the spent caustic liquors highly concentrated in phenol and alkyl phenols. The anaerobic technology is considered a feasible strategy for petrochemical wastewater pre-treatment although high concentrations of phenol could limit its efficiency. The goal of this work was to determine the toxicity of both selected alkyl phenols and a synthetic "spent-caustic phenols mixture" on the acetoclastic Specific Methanogenic Activity (SMA) of unadapted and phenol-adapted granular sludge. Alkyl phenols were responsible for 50% (IC50) and 100% (IC100) inhibition of the SMA at concentrations ranging from 1.6 to 5.0 mM and from 4.1 to 27.5 mM, respectively, for un-adapted granular sludge. In the case of phenol-adapted granular sludge, the inhibitory concentrations ranged from 1.7 to 14.9 mM and from 4.0 to 83.0 for IC50 and IC100, respectively, highlighting the impact of sludge acclimation. The inhibition produced by 2-ethylphenol was more acute compared to phenol and was not reduced by the phenol acclimation process. The IC50 and IC100 values obtained for the synthetic "spent-caustic phenols mixture" were 9.5 mM and 88.4 mM, respectively. The inhibitory concentrations of phenol compounds were closely correlated with compound apolarity (log P), indicating that the lipophilic character of the tested compounds was responsible for their methanogenic toxicity. An inhibition model is confirmed to estimate the IC50 and IC100.

Assessing Metal Mobilization from Industrially Lead-Contaminated Soils Located at an Urban Site

EPA Science Inventory

A series of leaching and partitioning tests (Toxicity Characteristic Leaching Procedure (TCLP), Synthetic Precipitation Leaching Procedure (SPLP), Controlled Acidity Leaching Protocol (CALP), Acid Neutralization Capacity (ANC), and sequential extraction) were applied to three dif...

Radiolytic Treatment of the Next-Generation Caustic-Side Solvent Extraction (NGS) Solvent and its Effect on the NGS Process

DOE PAGES

Roach, Benjamin D.; Williams, Neil J.; Duncan, Nathan C.; ...

2014-12-01

We show in this work that the solvent used in the Next Generation Caustic-Side Solvent Extraction (NGS) process can withstand a radiation dose well in excess of the dose it would receive in multiple years of treating legacy salt waste at the US Department of Energy Savannah River Site. The solvent was subjected to a maximum of 50 kGy of gamma radiation while in dynamic contact with each of the aqueous phases of the current NGS process, namely SRS-15 (a highly caustic waste simulant), sodium hydroxide scrub solution (0.025 M), and boric acid strip solution (0.01 M). Bench-top testing ofmore » irradiated solvent confirmed that irradiation has inconsequential impact on the extraction, scrubbing, and stripping performance of the solvent up to 13 times the estimated 0.73 kGy/y annual absorbed dose. Lastly, stripping performance is the most sensitive step to radiation, deteriorating more due to buildup of p-sec-butylphenol (SBP) and possibly other proton-ionizable products than to degradation of the guanidine suppressor, as shown by chemical analyses.« less

Radiolytic Treatment of the Next-Generation Caustic-Side Solvent Extraction (NGS) Solvent and its Effect on the NGS Process

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

Roach, Benjamin D.; Williams, Neil J.; Duncan, Nathan C.

We show in this work that the solvent used in the Next Generation Caustic-Side Solvent Extraction (NGS) process can withstand a radiation dose well in excess of the dose it would receive in multiple years of treating legacy salt waste at the US Department of Energy Savannah River Site. The solvent was subjected to a maximum of 50 kGy of gamma radiation while in dynamic contact with each of the aqueous phases of the current NGS process, namely SRS-15 (a highly caustic waste simulant), sodium hydroxide scrub solution (0.025 M), and boric acid strip solution (0.01 M). Bench-top testing ofmore » irradiated solvent confirmed that irradiation has inconsequential impact on the extraction, scrubbing, and stripping performance of the solvent up to 13 times the estimated 0.73 kGy/y annual absorbed dose. Lastly, stripping performance is the most sensitive step to radiation, deteriorating more due to buildup of p-sec-butylphenol (SBP) and possibly other proton-ionizable products than to degradation of the guanidine suppressor, as shown by chemical analyses.« less

Leaching of Conductive Species: Implications to Measurements of Electrical Resistivity

PubMed Central

Spragg, R; Jones, S; Bu, Y; Lu, Y; Bentz, D; Snyder, K; Weiss, J

2017-01-01

Electrical tests have been used to characterize the microstructure of porous materials, the measured electrical response being determined by the contribution of the microstructure (porosity and tortuosity) and the electrical properties of the solution (conductivity of the pore solution) inside the pores of the material. This study has shown how differences in concentration between the pore solution (i.e., the solution in the pores) and the storage solution surrounding the test specimen leads to significant transport (leaching) of the conductive ionic species between the pore solution and the storage solution. Leaching influences the resistivity of the pore solution, thereby influencing electrical measurements on the bulk material from either a surface or uniaxial bulk resistance test. This paper has three main conclusions: 1.) Leaching of conductive species does occur with concentration gradients and that a diffusion based approach can be used to estimate the time scale associated with this change. 2.) Leaching of ions in the pore solution can influence resistivity measurements, and the ratio of surface to uniaxial resistivity can be used as a method to assess the presence of leaching and 3.) An estimation of the magnitude of leaching for standardized tests of cementitious materials. PMID:28584407

Leaching of Conductive Species: Implications to Measurements of Electrical Resistivity.

PubMed

Spragg, R; Jones, S; Bu, Y; Lu, Y; Bentz, D; Snyder, K; Weiss, J

2017-05-01

Electrical tests have been used to characterize the microstructure of porous materials, the measured electrical response being determined by the contribution of the microstructure (porosity and tortuosity) and the electrical properties of the solution (conductivity of the pore solution) inside the pores of the material. This study has shown how differences in concentration between the pore solution (i.e., the solution in the pores) and the storage solution surrounding the test specimen leads to significant transport (leaching) of the conductive ionic species between the pore solution and the storage solution. Leaching influences the resistivity of the pore solution, thereby influencing electrical measurements on the bulk material from either a surface or uniaxial bulk resistance test. This paper has three main conclusions: 1.) Leaching of conductive species does occur with concentration gradients and that a diffusion based approach can be used to estimate the time scale associated with this change. 2.) Leaching of ions in the pore solution can influence resistivity measurements, and the ratio of surface to uniaxial resistivity can be used as a method to assess the presence of leaching and 3.) An estimation of the magnitude of leaching for standardized tests of cementitious materials.

Geochemical modeling of leaching of Ca, Mg, Al, and Pb from cementitious waste forms

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

Martens, E., E-mail: evelien.martens@csiro.a; Jacques, D.; Van Gerven, T.

2010-08-15

Results from extraction tests on cement-waste samples were simulated with a thermodynamic equilibrium model using a consistent database, to which lead data were added. Subsequent diffusion tests were modeled by means of a 3D diffusive transport model combined with the geochemical model derived from the extraction tests. Modeling results of the leached major element concentrations for both uncarbonated and (partially) carbonated samples agreed well with the extraction test using the set of pure minerals and solid solutions present in the database. The observed decrease in Ca leaching with increasing carbonation level was qualitatively predicted. Simulations also revealed that Pb leachingmore » is not controlled by dissolution/precipitation only. The addition of the calcite-cerrusite solid solution and adsorption reactions on amorphous Fe- and Al-oxides improved the predictions and are considered to control the Pb leaching during the extractions tests. The dynamic diffusive leaching tests were appropriately modeled for Na, K, Ca and Pb.« less

Investigation of the leaching behavior of lead in stabilized/solidified waste using a two-year semi-dynamic leaching test.

PubMed

Xue, Qiang; Wang, Ping; Li, Jiang-Shan; Zhang, Ting-Ting; Wang, Shan-Yong

2017-01-01

Long-term leaching behavior of contaminant from stabilization/solidification (S/S) treated waste stays unclear. For the purpose of studying long-term leaching behavior and leaching mechanism of lead from cement stabilized soil under different pH environment, semi-dynamic leaching test was extended to two years to investigate leaching behaviors of S/S treated lead contaminated soil. Effectiveness of S/S treatment in different scenarios was evaluated by leachability index (LX) and effective diffusion coefficient (D e ). In addition, the long-term leaching mechanism was investigated at different leaching periods. Results showed that no significant difference was observed among the values of the cumulative release of Pb, D e and LX in weakly alkaline and weakly acidic environment (pH value varied from 5.00 to 10.00), and all the controlling leaching mechanisms of the samples immersed in weakly alkaline and weakly acidic environments turned out to be diffusion. Strong acid environment would significantly affect the leaching behavior and leaching mechanism of lead from S/S monolith. The two-year variation of D e appeared to be time dependent, and D e values increased after the 210 th day in weakly alkaline and weakly acidic environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

ION EXCHANGE TESTS ON LIQUOR AND PULPS PRODUCED FROM UTEX ORES. Topical Report

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

Hollis, E.T.; Pickwick, F.J. Jr.; Kazanjian, A.R.

1954-07-30

Uranium leach liquors produced from Utex ore by cold leaching, hot leaching, and pugging proved amenable to the lon exchange process, Higher resin loadings were obtained rom the cold leach liquors than from the hot leach and pug liquors. In general, the less vigorous leaching conditions produced liquors which gave the highest resin loadings. In addition, a resin-in-pulp system was operated using the lucite Winchester cells on Utex pulp produced by cold leaching. Satisfactory loadings were obtained. (auth)

Leaching Environmental Assessment Framework to Evaluate Beneficial Use and Disposal Decisions

EPA Science Inventory

LEAF test methods are available for use to characterize the leaching potential over a range of conditions (i.e., pH, liquid-to-solid ratio, and waste form). LEAF characterization tests can be used to evaluate a range of materials to identify leaching behavior across a range of ...

NEXT GENERATION LEACHING TESTS FOR EVALUATING LEACHING OF INORGANIC CONSTITUENTS

EPA Science Inventory

In the U.S. as in other countries, there is increased interest in using industrial by-products as alternative or secondary materials, helping to conserve virgin or raw materials. The LEAF and associated test methods are being used to develop the source term for leaching or any i...

Extreme Wave Statistics within the Mouth of the Columbia River

DTIC Science & Technology

2014-12-01

nearshore coastal environment. Because of his guidance, I was able to make the most of this challenging learning experience. I spent countless hours...the current field induces a refractive caustic along the principal current axis. Caustic focusing causes an increase of wave height to its maximum...the largest waves are found upstream of the caustic area (around x/Lo=25 in Figure 6). 10 Figure 6. Transformation of 0.1-Hz swell

Hazardous Waste Minimization Guide for Shipyards

DTIC Science & Technology

1994-01-01

any waste generation associated with spent sol- vent. Elimination can be achieved by utiliza- tion of non-solvent cleaning agents or elimi- nating the...alkali, citric, and caustic base, are often useful substitutes for solvents. There are many for- mulations that are suited for a variety of clean- ing...agents, such as caustic soda (NaOH), are often employed in place of meth- ylene chloride based strippers. Caustic solu- tions have the advantage of

Leachate Testing of Hamlet City Lake, North Carolina, Sediment

DTIC Science & Technology

1992-11-01

release; distribution is unlimited. 13. ABSTRACT (Maximum 200 words) Sediment leaching studies of Hamlet City Lake, Hamlet, NC, were conducted in...laboratories at the U.S. Army Engineer Waterways Experiment Station. The pur- pose of these studies was to provide quantitative information on the...conditions similar to landfarming. The study involved three elements: batch leach tests, column leach tests, and simulations using the Hydrologic

Implementation of the Leaching Environmental Assessment Framework

EPA Science Inventory

New leaching tests are available in the U.S. for developing more accurate source terms for use in fate and transport models. For beneficial use or disposal, the use of the leaching environmental assessment framework (LEAF) will provide leaching results that reflect field condit...

Antimony smelting process generating solid wastes and dust: characterization and leaching behaviors.

PubMed

Guo, Xuejun; Wang, Kunpeng; He, Mengchang; Liu, Ziwei; Yang, Hailin; Li, Sisi

2014-07-01

A large amount of solid waste has been produced by the antimony smelting process in the "World Capital of Antimony", Xikuangshan area in China. This study comprehensively investigated the physical and chemical characteristics of the various solid wastes, as well as the leaching behavior of the solid wastes, which included water-quenched slag, arsenic-alkali residue, desulfurized slag and blast furnace dust. These four types of waste were enriched in a variety of heavy metals and metalloids and more specifically with As and Sb levels up to 8.6 × 10⁴ and 3.16×10⁵ mg/kg, respectively, in arsenic-alkali residue. For desulfurized slag and water-quenched slag, the leaching concentration of Sb significantly exceeded the acceptable limits during the leaching tests using the toxicity characteristic leaching procedure and the synthetic precipitation leaching procedure. In addition, As leaching in arsenic-alkali residue was extraordinarily hazardous, being three orders of magnitude higher than the regulatory level of As. According to the results of the extraction tests, all the tested wastes were classified as hazardous waste. Copyright © 2014. Published by Elsevier B.V.

Diffraction and Dissipation of Atmospheric Waves in the Vicinity of Caustics

NASA Astrophysics Data System (ADS)

Godin, O. A.

2015-12-01

A large and increasing number of ground-based and satellite-borne instruments has been demonstrated to reliably reveal ionospheric manifestations of natural hazards such as large earthquakes, strong tsunamis, and powerful tornadoes. To transition from detection of ionospheric manifestations of natural hazards to characterization of the hazards for the purposes of improving early warning systems and contributing to disaster recovery, it is necessary to relate quantitatively characteristics of the observed ionospheric disturbances and the underlying natural hazard and, in particular, accurately model propagation of atmospheric waves from the ground or ocean surface to the ionosphere. The ray theory has been used extensively to model propagation of atmospheric waves and proved to be very efficient in elucidating the effects of atmospheric variability on ionospheric signatures of natural hazards. However, the ray theory predicts unphysical, divergent values of the wave amplitude and needs to be modified in the vicinity of caustics. This paper presents an asymptotic theory that describes diffraction, focusing and increased dissipation of acoustic-gravity waves in the vicinity of caustics and turning points. Air temperature, viscosity, thermal conductivity, and wind velocity are assumed to vary gradually with height and horizontal coordinates, and slowness of these variations determines the large parameter of the problem. Uniform asymptotics of the wave field are expressed in terms of Airy functions and their derivatives. The geometrical, or Berry, phase, which arises in the consistent WKB approximation for acoustic-gravity waves, plays an important role in the caustic asymptotics. In addition to the wave field in the vicinity of the caustic, these asymptotics describe wave reflection from the caustic and the evanescent wave field beyond the caustic. The evanescent wave field is found to play an important role in ionospheric manifestations of tsunamis.

Environmental Review Guide for Operations (ERGO) - A Compliance Assessment Manual for Use at All USACE Civil-Funded Projects and Facilities

DTIC Science & Technology

1994-03-01

other Pickling liquor and other corrosive alkalies corrosive acids Lime wastewater Spent acid Lime and water Spent mixed acid Spent caustic Spent ...acid Spent caustic Spent sulfuric acid Potential Consequences: heat generation; violent reaction. 4 - 161 Appendix 4-6 (continued) Group 2-A Group 2-B1...topical bleach (STB) Ordnance, ammunition, explosives & residues Battery acid & caustics (in unserviceable batteries) Some pharmaceuticals Petroleum, oil

United States Air Force Shale Oil to Fuels. Phase II.

DTIC Science & Technology

1981-11-01

and modified so that any off-gas from the LPS, stripper column, product drums, spent caustic drums, and sample ports would be sent to the caustic ...product, or in the spent caustic . After the desalted Paraho shale oil was processed in Production Run No. 2, the catalyst bed was flushed with light cycle...58 20 First-Stage Hydrotreating of Occidental Shale Oil -- Spent Catalyst Analysis - Run 1 ....... 59 21 First-Stage Hydrotreating of Occidental

Quantification of the effects of environmental leaching factors on emissions from bottom ash in road construction.

PubMed

Ecke, Holger; Aberg, Annika

2006-06-01

The re-use of bottom ash in road construction necessitates a tool to predict the impact of trace metals on the surroundings over the lifetime of the road. The aim of this work was to quantify the effect of environmental factors that are supposed to influence leaching, so as to suggest guidelines in developing a leaching procedure for the testing of incineration residues re-used in road constructions. The effects of pH, L/S (liquid-to-solid ratio), leaching time, and leaching atmosphere on the leachate concentrations of Cd, Cr, Cu, Ni, Pb, and Zn were studied using a two-level full factorial design. The most significant factor for all responses was the pH, followed by L/S, though the importance of pH and L/S is often ignored in leaching tests. Multiple linear regression models describing the variation in leaching data had R(2) values ranging from 61-97%. A two-step pH-stat leaching procedure that considers pH as well as L/S and leaching time was suggested.

Geochemical anomalies from bottom ash in a road construction--comparison of the leaching potential between an ash road and the surroundings.

PubMed

Lind, Bo B; Norrman, Jenny; Larsson, Lennart B; Ohlsson, Sten-Ake; Bristav, Henrik

2008-01-01

A study was performed between June 2001 and December 2004 with the primary objective of assessing long-term leaching from municipal solid waste incineration bottom ash in a test road construction in relation to a reference road made up of conventional materials and the natural geochemical conditions in the surroundings. The metal leaching from the test road and the reference road was compared with the natural weathering in the regional surroundings for three time scales: 16, 80 and 1000 years. The results show that Cu and Zn cause a geochemical anomaly from the test road compared with the surroundings. The leaching of Cu from the test road is initially high but will decline with time and will in the long term be exceeded by natural weathering. Zn on the other hand has low initial leaching, which will increase with time and will in the long term exceed that of the test road and the surroundings by a factor of 100-300. For the other metals studied, Al, Na, K and Mg, there is only very limited leaching over time and the potential accumulation will not exceed the background values in a 1000 years.

Leaching behaviour of hazardous waste under the impact of different ambient conditions.

PubMed

Pecorini, Isabella; Baldi, Francesco; Bacchi, Donata; Carnevale, Ennio Antonio; Corti, Andrea

2017-05-01

The overall objective of this study is to provide an improved basis for the assessment of the leaching behaviour of waste marked as hazardous partly stabilised (European waste catalogue code 19 03 04 ∗ ). Four samples of hazardous partly stabilised waste were subjected to two leaching tests: up-flow column tests and batch equilibrium tests. The research was carried out in two directions: the first aims at comparing the results of the two experimental setups while the second aims at assessing the impact of different ambient conditions on the leaching behaviour of waste. Concerning this latter objective the effect of mesophilic temperature, mechanical constraints and acid environment were tested through column percolation tests. Results showed no significant differences between batch and column leaching test outcomes when comparing average concentrations calculated at a liquid to solid ratio of 10:1 l kg -1  TS. Among the tested ambient conditions, the presence of an acid environment (pH=4.5) accelerated the leaching process resulting in a higher cumulative released quantity measured on the majority of the investigated polluting substances. On the contrary, the effect of temperature and mechanical constraints seemed to not affect the process showing final contents even lower than values found for the standard test. This result was furthermore confirmed by the application of the principal component analysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Caustics of 1/r{sup n} binary gravitational lenses: from galactic haloes to exotic matter

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

Bozza, V.; Melchiorre, C., E-mail: valboz@physics.unisa.it, E-mail: cmelchiorre@unisa.it

2016-03-01

We investigate the caustic topologies for binary gravitational lenses made up of two objects whose gravitational potential declines as 1/r{sup n}. With n<1 this corresponds to power-law dust distributions like the singular isothermal sphere. The n>1 regime can be obtained with some violations of the energy conditions, one famous example being the Ellis wormhole. Gravitational lensing provides a natural arena to distinguish and identify such exotic objects in our Universe. We find that there are still three topologies for caustics as in the standard Schwarzschild binary lens, with the main novelty coming from the secondary caustics of the close topology,more » which become huge at higher n. After drawing caustics by numerical methods, we derive a large amount of analytical formulae in all limits that are useful to provide deeper insight in the mathematics of the problem. Our study is useful to better understand the phenomenology of galaxy lensing in clusters as well as the distinct signatures of exotic matter in complex systems.« less

Leaching of PFC from soils contaminated with PFC of different origin

NASA Astrophysics Data System (ADS)

Kalbe, Ute; Piechotta, Christian; Rothe, Robert

2017-04-01

Leaching tests are fundamental tools for the assessment of groundwater impact by contaminated soils concerning the soil-groundwater pathway. Such procedures are supposed to serve as the basis for a reliable leachate prognosis. They can be applied to determine the short and long term leaching behaviour as well as the source term of contaminated soils. For this purpose two types of leaching procedures have been validated in Germany for the examination of the leaching behaviour of frequently occurring organic substances (DIN 19528 - column test and DIN 19529 - batch test). A liquid-to-solid ratio (L/S) of 2 L/kg and 10 L/kg) is the basis for the risk assessment which is implemented in different German regulations. The equivalence of test results for both tests for the same material under investigation has been investigated for a variety of pollutants in order to assess their reliability in compliance testing. However, for emerging pollutants there is hardly data available on this issue. Leaching tests on soils contaminated with emerging pollutants such as PFC (Perfluorinated Surfactants) are currently coming more into consideration due to the increasing detection of contaminated sites. Therefore, two soils were investigated in this study from different contamination source (paper sludge containing compost and fire distinguishing foam) using both leaching tests and both liquid-to-solid ratios. The leachability of the various perfluorinated compounds in relation to their content in solid matter was considered. Furthermore the eluate pre-treatment prior analysis (in particular liquid/solid separation step needed for batch tests) has been taken into account. The comparability of the results from batch and column is dependent on the solubility of the various compounds, on the L/S and on the turbidity in the eluates.

Fractionation of iron isotopes during leaching of natural particles by acidic and circumneutral leaches and development of an optimal leach for marine particulate iron isotopes

NASA Astrophysics Data System (ADS)

Revels, Brandi N.; Zhang, Ruifeng; Adkins, Jess F.; John, Seth G.

2015-10-01

Iron (Fe) is an essential nutrient for life on land and in the oceans. Iron stable isotope ratios (δ56Fe) can be used to study the biogeochemical cycling of Fe between particulate and dissolved phases in terrestrial and marine environments. We have investigated the dissolution of Fe from natural particles both to understand the mechanisms of Fe dissolution, and to choose a leach appropriate for extracting labile Fe phases of marine particles. With a goal of finding leaches which would be appropriate for studying dissolved-particle interactions in an oxic water column, three particle types were chosen including oxic seafloor sediments (MESS-3), terrestrial dust (Arizona Test Dust - A2 Fine), and ocean sediment trap material from the Cariaco basin. Four leaches were tested, including three acidic leaches similar to leaches previously applied to marine particles and sediments (25% acetic acid, 0.01 N HCl, and 0.5 N HCl) and a pH 8 oxalate-EDTA leach meant to mimic the dissolution of particles by organic complexation, as occurs in natural seawater. Each leach was applied for three different times (10 min, 2 h, 24 h) at three different temperatures (25 °C, 60 °C, 90 °C). MESS-3 was also leached under various redox conditions (0.02 M hydroxylamine hydrochloride or 0.02 M hydrogen peroxide). For all three sample types tested, we find a consistent relationship between the amount of Fe leached and leachate δ56Fe for all of the acidic leaches, and a different relationship between the amount of Fe leached and leachate δ56Fe for the oxalate-EDTA leach, suggesting that Fe was released through proton-promoted dissolution for all acidic leaches and by ligand-promoted dissolution for the oxalate-EDTA leach. Fe isotope fractionations of up to 2‰ were observed during acidic leaching of MESS-3 and Cariaco sediment trap material, but not for Arizona Test Dust, suggesting that sample composition influences fractionation, perhaps because Fe isotopes are greatly fractionated during leaching of silicates and clays but only minimally fractionated during dissolution of Fe oxyhydroxides. Two different analytical models were developed to explain the relationship between amount of Fe leached and δ56Fe, one of which assumes mixing between two Fe phases with different δ56Fe and different dissolution rates, and the other of which assumes dissolution of a single phase with a kinetic isotope effect. We apply both models to fit results from the acidic leaches of MESS-3 and find that the fit for both models is very similar, suggesting that isotope data will never be sufficient to distinguish between these two processes for natural materials. Next, we utilize our data to choose an optimal leach for application to marine particles. The oxalate-EDTA leach is well-suited to this purpose because it does not greatly fractionate Fe isotopes for a diversity of particle types over a wide variety of leaching conditions, and because it approximates the conditions by which particulate Fe dissolves in the oceans. We recommend a 2 h leach at 90 °C with 0.1 M oxalate and 0.05 M EDTA at pH 8 to measure labile ;ligand-leachable; particulate δ56Fe on natural marine materials with a range of compositions.

Next Generation Solvent (NGS): Development for Caustic-Side Solvent Extraction of Cesium

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

Moyer, Bruce A.; Birdwell, Jr, Joseph F.; Bonnesen, Peter V.

This report summarizes the FY 2010 and 2011 accomplishments at Oak Ridge National Laboratory (ORNL) in developing the Next Generation Caustic-Side Solvent Extraction (NG-CSSX) process, referred to commonly as the Next Generation Solvent (NGS), under funding from the U.S. Department of Energy, Office of Environmental Management (DOE-EM), Office of Technology Innovation and Development. The primary product of this effort is a process solvent and preliminary flowsheet capable of meeting a target decontamination factor (DF) of 40,000 for worst-case Savannah River Site (SRS) waste with a concentration factor of 15 or higher in the 18-stage equipment configuration of the SRS Modularmore » Caustic-Side Solvent Extraction Unit (MCU). In addition, the NG-CSSX process may be readily adapted for use in the SRS Salt Waste Processing Facility (SWPF) or in supplemental tank-waste treatment at Hanford upon appropriate solvent or flowsheet modifications. Efforts in FY 2010 focused on developing a solvent composition and process flowsheet for MCU implementation. In FY 2011 accomplishments at ORNL involved a wide array of chemical-development activities and testing up through single-stage hydraulic and mass-transfer tests in 5-cm centrifugal contactors. Under subcontract from ORNL, Argonne National Laboratory (ANL) designed a preliminary flowsheet using ORNL cesium distribution data, and Tennessee Technological University confirmed a chemical model for cesium distribution ratios (DCs) as a function of feed composition. Interlaboratory efforts were coordinated with complementary engineering tests carried out (and reported separately) by personnel at Savannah River National Laboratory (SRNL) and Savannah River Remediation (SRR) with helpful advice by Parsons Engineering and General Atomics on aspects of possible SWPF implementation.« less

Next Generation Solvent Development for Caustic-Side Solvent Extraction of Cesium

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

Moyer, Bruce A.; Birdwell, Joseph F.; Bonnesen, Peter V.

This report summarizes the FY 2010 and 2011 accomplishments at Oak Ridge National Laboratory (ORNL) in developing the Next Generation Caustic-Side Solvent Extraction (NG-CSSX) process, referred to commonly as the Next Generation Solvent (NGS), under funding from the U.S. Department of Energy, Office of Environmental Management (DOE-EM), Office of Technology Innovation and Development. The primary product of this effort is a process solvent and preliminary flowsheet capable of meeting a target decontamination factor (DF) of 40,000 for worst-case Savannah River Site (SRS) waste with a concentration factor of 15 or higher in the 18-stage equipment configuration of the SRS Modularmore » Caustic-Side Solvent Extraction Unit (MCU). In addition, the NG-CSSX process may be readily adapted for use in the SRS Salt Waste Processing Facility (SWPF) or in supplemental tank-waste treatment at Hanford upon appropriate solvent or flowsheet modifications. Efforts in FY 2010 focused on developing a solvent composition and process flowsheet for MCU implementation. In FY 2011 accomplishments at ORNL involved a wide array of chemical-development activities and testing up through single-stage hydraulic and mass-transfer tests in 5-cm centrifugal contactors. Under subcontract from ORNL, Argonne National Laboratory (ANL) designed a preliminary flowsheet using ORNL cesium distribution data, and Tennessee Technological University confirmed a chemical model for cesium distribution ratios (DCs) as a function of feed composition. Inter laboratory efforts were coordinated with complementary engineering tests carried out (and reported separately) by personnel at Savannah River National Laboratory (SRNL) and Savannah River Remediation (SRR) with helpful advice by Parsons Engineering and General Atomics on aspects of possible SWPF implementation.« less

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

Caustic Skeleton & Cosmic Web

NASA Astrophysics Data System (ADS)

Feldbrugge, Job; van de Weygaert, Rien; Hidding, Johan; Feldbrugge, Joost

2018-05-01

We present a general formalism for identifying the caustic structure of a dynamically evolving mass distribution, in an arbitrary dimensional space. The identification of caustics in fluids with Hamiltonian dynamics, viewed in Lagrangian space, corresponds to the classification of singularities in Lagrangian catastrophe theory. On the basis of this formalism we develop a theoretical framework for the dynamics of the formation of the cosmic web, and specifically those aspects that characterize its unique nature: its complex topological connectivity and multiscale spinal structure of sheetlike membranes, elongated filaments and compact cluster nodes. Given the collisionless nature of the gravitationally dominant dark matter component in the universe, the presented formalism entails an accurate description of the spatial organization of matter resulting from the gravitationally driven formation of cosmic structure. The present work represents a significant extension of the work by Arnol'd et al. [1], who classified the caustics that develop in one- and two-dimensional systems that evolve according to the Zel'dovich approximation. His seminal work established the defining role of emerging singularities in the formation of nonlinear structures in the universe. At the transition from the linear to nonlinear structure evolution, the first complex features emerge at locations where different fluid elements cross to establish multistream regions. Involving a complex folding of the 6-D sheetlike phase-space distribution, it manifests itself in the appearance of infinite density caustic features. The classification and characterization of these mass element foldings can be encapsulated in caustic conditions on the eigenvalue and eigenvector fields of the deformation tensor field. In this study we introduce an alternative and transparent proof for Lagrangian catastrophe theory. This facilitates the derivation of the caustic conditions for general Lagrangian fluids, with arbitrary dynamics. Most important in the present context is that it allows us to follow and describe the full three-dimensional geometric and topological complexity of the purely gravitationally evolving nonlinear cosmic matter field. While generic and statistical results can be based on the eigenvalue characteristics, one of our key findings is that of the significance of the eigenvector field of the deformation field for outlining the entire spatial structure of the caustic skeleton emerging from a primordial density field. In this paper we explicitly consider the caustic conditions for the three-dimensional Zel'dovich approximation, extending earlier work on those for one- and two-dimensional fluids towards the full spatial richness of the cosmic web. In an accompanying publication, we apply this towards a full three-dimensional study of caustics in the formation of the cosmic web and evaluate in how far it manages to outline and identify the intricate skeletal features in the corresponding N-body simulations.

Proceedings of the DICE THROW Symposium 21-23 June 1977. Volume 2

DTIC Science & Technology

1977-07-01

structure between 2.7 km and 4.3 km MSL that could cause distant blast focusing. Detailed acoustic ray calculations showed a caustic ring about 10 km...depending on just wheie the focus or caustic wave might strike. Propagation toward Truth or Consequences, MM, shown by Figure 14, was slightly ducted...layer. Thus there probably was no focus or caustic that struck any part of that small town. The recorded signal with 370-Pa amplitude was noisy

U S Navy Diving Manual. Volume 2. Mixed-Gas Diving. Revision 1.

DTIC Science & Technology

1981-07-01

has been soaked in a solution of portant aspects of underwater physics and physiology caustic potash. This chemical absorbed the carbon as they...between the diver’s breathing passages and the circuit must be of minimum volume minimum of caustic fumes. Water produced by the to preclude deadspace and...strongly react with water to pro- space around the absorbent bed to reduce the gas duce caustic fumes and cannot be used in UBA’s. flow distance. The

Modelling Bathymetric Control of Near Coastal Wave Climate. Report 2

DTIC Science & Technology

1990-04-01

given in Sub (1989), showing that the nonlinearity is important at the transects 4 and 5 where the wave has passed through the caustic cusp. Here we...pronounced, especially 22 I 3 on the right side of the caustic cusp. The overall shapes of the results of the parabolic model for 0, = 450 and 600 are...the positive z direction. The shift becomes severe with increasing angle of incidence, and it is more prominent on the right side of the caustic cusp

A Review of the Pollution Abatement Programs Relating to the Petroleum Refinery Industry in the Great Lakes Basin

DTIC Science & Technology

1982-11-01

of spent acids and caustics . The oil content of disposed wastes is 6,200 metric tons per year or approximately .01% of the average crude refinery rate...ALKYLATION "The major discharge from sulfuric acid alkylation are the spent caustics from the neutralization of hydrocarbon streams leaving the sulfuric... spent caustic waste stream. Any leaks or spills that involve loss of fluorides constitute a serious and difficult pollution problem. Formation of

Effect of heat stable salts on MDEA solution corrosivity: Part 2

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

Rooney, P.C.; DuPart, M.S.; Bacon, T.R.

1997-04-01

A comprehensive coupon corrosion testing program was undertaken to address the effect of various heat stable salts on methyldiethanolamine (MDEA) corrosivity to carbon steel and various stainless steels. Corrosion rates of carbon steel, 304SS, 316SS and 410SS liquid and vapor coupons towards MDEA, and MDEA containing various anions, at 180 F and 250 F, were measured in a reactor. Corrosion results of two refinery plant solutions before and after caustic neutralization were also performed. Based on these results, guidelines were determined for heat stable amine salt (HSAS) levels of oxalates, sulfates, formates, acetates and thiosulfates. In addition, caustic neutralization guidelinesmore » for MDEA heat stable salts were determined. Ongoing results include MDEA corrosivity with succinates, and malonates, glycolates, SO{sub 2} and ammonia.« less

Evaluation of the impact of lime softening waste disposal in ...

EPA Pesticide Factsheets

Drinking water treatment residues (WTR), generated from the lime softening processes, are commonly reused or disposed of in a number of applications; these include use as a soil amendment or a subsurface fill. Recently questions were posed by the Florida regulatory community on whether lime WTR that contained a small percentage of other treatment additives could appropriately be characterized as lime WTR, in terms of its total element content and leachability. A study was done using a broad range of leaching tests, including a framework of tests recently adopted by the United States-Environmental Protection Agency (EPA) and tests that were modified to account for scenario specific conditions, such as the presence of natural organic matter (NOM). The results of these additional leaching tests demonstrated that certain applications, including disposal in a water body with NOM or in placement anaerobic environment, did result in increased leaching of elements such as Fe, and that a site specific assessment should be conducted prior to using WTR in these types of applications. This study illustrates the importance of leaching test selection when attempting to provide an estimation of release in practice. Although leaching tests are just one component in a beneficial use assessment and other factors including aquifer and soil properties play a significant role in the outcome, leaching tests should be tailored to most appropriately represent the scenario or reuse ap

CO2 Sparging Proof of Concept Test Report, Revision 1, LCP Chemicals Site, Brunswick, Georgia

EPA Pesticide Factsheets

April 2013 report to evaluate the feasibility of CO2 sparging to remediate a sub-surface caustic brine pool (CBP) at the LCP Chemicals Superfund Site, GA. Region ID : 04, DocID: 10940639 , DocDate: 2013-04-01

APL - North Pacific Acoustic Laboratory

DTIC Science & Technology

2015-03-04

PhilSea10 cruise were spent in a series of upgrades and associated tests of the TCTD system. Electronic upgrades in conjunction with the manufacturers, ADM...amplitude at positions sufficiently removed from caustics . Mr. White computed eigenrays to all tracked upper array hydrophone positions relative to each

Thermal stability study of a new guanidine suppressor for the next-generation caustic-side solvent extraction process

DOE PAGES

Hill, Talon G.; Ensor, Dale D.; Delmau, Lætitia Helene; ...

2016-02-06

Cesium stripping performance of thermally stressed solvent degrades slowly over time in batch tests of the Next Generation Caustic-Side Solvent Extraction (NGS) process. NGS is currently used at pilot scale at the Savannah River Site for the selective removal of cesium from high-level salt waste. Recently a new guanidine, N,N',N" -tris(3,7-dimethyloctyl)guanidine (TiDG), was chosen for use as the suppressor, a lipophilic organic base needed for stripping, and the present study was undertaken to address the question of its stability. The NGS process solvent was evaluated for a period of three months under a variety of temperature and storage conditions. Themore » performance of the solvent was tested at 30-day increments using a standard extraction, scrub, strip, and extraction (ES 2S 3E) sequence. Lastly, the results provide insight on the effects of storage and process conditions, the stripping behavior of TiDG, and the stability of the new solvent composition.« less

Thermal stability study of a new guanidine suppressor for the next-generation caustic-side solvent extraction process

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

Hill, Talon G.; Ensor, Dale D.; Delmau, Lætitia Helene

Cesium stripping performance of thermally stressed solvent degrades slowly over time in batch tests of the Next Generation Caustic-Side Solvent Extraction (NGS) process. NGS is currently used at pilot scale at the Savannah River Site for the selective removal of cesium from high-level salt waste. Recently a new guanidine, N,N',N" -tris(3,7-dimethyloctyl)guanidine (TiDG), was chosen for use as the suppressor, a lipophilic organic base needed for stripping, and the present study was undertaken to address the question of its stability. The NGS process solvent was evaluated for a period of three months under a variety of temperature and storage conditions. Themore » performance of the solvent was tested at 30-day increments using a standard extraction, scrub, strip, and extraction (ES 2S 3E) sequence. Lastly, the results provide insight on the effects of storage and process conditions, the stripping behavior of TiDG, and the stability of the new solvent composition.« less

21 CFR 1230.37 - Publication.

Code of Federal Regulations, 2010 CFR

2010-04-01

... CAUSTIC POISON ACT Administrative Procedures § 1230.37 Publication. (a) After judgment of the court in any proceeding under the Federal Caustic Poison Act, notice shall be given by publication. Such notice shall...

21 CFR 1230.37 - Publication.

Code of Federal Regulations, 2014 CFR

2014-04-01

... CAUSTIC POISON ACT Administrative Procedures § 1230.37 Publication. (a) After judgment of the court in any proceeding under the Federal Caustic Poison Act, notice shall be given by publication. Such notice shall...

21 CFR 1230.37 - Publication.

Code of Federal Regulations, 2012 CFR

2012-04-01

... CAUSTIC POISON ACT Administrative Procedures § 1230.37 Publication. (a) After judgment of the court in any proceeding under the Federal Caustic Poison Act, notice shall be given by publication. Such notice shall...

21 CFR 1230.37 - Publication.

Code of Federal Regulations, 2013 CFR

2013-04-01

... CAUSTIC POISON ACT Administrative Procedures § 1230.37 Publication. (a) After judgment of the court in any proceeding under the Federal Caustic Poison Act, notice shall be given by publication. Such notice shall...

21 CFR 1230.37 - Publication.

Code of Federal Regulations, 2011 CFR

2011-04-01

... CAUSTIC POISON ACT Administrative Procedures § 1230.37 Publication. (a) After judgment of the court in any proceeding under the Federal Caustic Poison Act, notice shall be given by publication. Such notice shall...

21 CFR 1230.48 - Relabeling of containers.

Code of Federal Regulations, 2012 CFR

2012-04-01

... FEDERAL CAUSTIC POISON ACT Imports § 1230.48 Relabeling of containers. (a) If containers are to be... requirements of the Federal Caustic Poison Act and all regulations and instructions issued thereunder. The...

21 CFR 1230.48 - Relabeling of containers.

Code of Federal Regulations, 2011 CFR

2011-04-01

... FEDERAL CAUSTIC POISON ACT Imports § 1230.48 Relabeling of containers. (a) If containers are to be... requirements of the Federal Caustic Poison Act and all regulations and instructions issued thereunder. The...

21 CFR 1230.48 - Relabeling of containers.

Code of Federal Regulations, 2013 CFR

2013-04-01

... FEDERAL CAUSTIC POISON ACT Imports § 1230.48 Relabeling of containers. (a) If containers are to be... requirements of the Federal Caustic Poison Act and all regulations and instructions issued thereunder. The...

21 CFR 1230.48 - Relabeling of containers.

Code of Federal Regulations, 2010 CFR

2010-04-01

... FEDERAL CAUSTIC POISON ACT Imports § 1230.48 Relabeling of containers. (a) If containers are to be... requirements of the Federal Caustic Poison Act and all regulations and instructions issued thereunder. The...

21 CFR 1230.48 - Relabeling of containers.

Code of Federal Regulations, 2014 CFR

2014-04-01

... FEDERAL CAUSTIC POISON ACT Imports § 1230.48 Relabeling of containers. (a) If containers are to be... requirements of the Federal Caustic Poison Act and all regulations and instructions issued thereunder. The...

27 CFR 21.63 - Formula No. 36.

Code of Federal Regulations, 2012 CFR

2012-04-01

... pounds of caustic soda, liquid grade, containing 50 percent sodium hydroxide by weight; or 12.0 pounds of caustic soda, liquid grade, containing 73 percent sodium hydroxide by weight. (b) Authorized uses. (1) As...

27 CFR 21.63 - Formula No. 36.

Code of Federal Regulations, 2014 CFR

2014-04-01

... pounds of caustic soda, liquid grade, containing 50 percent sodium hydroxide by weight; or 12.0 pounds of caustic soda, liquid grade, containing 73 percent sodium hydroxide by weight. (b) Authorized uses. (1) As...

27 CFR 21.63 - Formula No. 36.

Code of Federal Regulations, 2013 CFR

2013-04-01

... pounds of caustic soda, liquid grade, containing 50 percent sodium hydroxide by weight; or 12.0 pounds of caustic soda, liquid grade, containing 73 percent sodium hydroxide by weight. (b) Authorized uses. (1) As...

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

Solidified structure and leaching properties of metallurgical wastewater treatment sludge after solidification/stabilization process.

PubMed

Radovanović, Dragana Đ; Kamberović, Željko J; Korać, Marija S; Rogan, Jelena R

2016-01-01

The presented study investigates solidification/stabilization process of hazardous heavy metals/arsenic sludge, generated after the treatment of the wastewater from a primary copper smelter. Fly ash and fly ash with addition of hydrated lime and Portland composite cement were studied as potential binders. The effectiveness of the process was evaluated by unconfined compressive strength (UCS) testing, leaching tests (EN 12457-4 and TCLP) and acid neutralization capacity (ANC) test. It was found that introduction of cement into the systems increased the UCS, led to reduced leaching of Cu, Ni and Zn, but had a negative effect on the ANC. Gradual addition of lime resulted in decreased UCS, significant reduction of metals leaching and high ANC, due to the excess of lime that remained unreacted in pozzolanic reaction. Stabilization of more than 99% of heavy metals and 90% of arsenic has been achieved. All the samples had UCS above required value for safe disposal. In addition to standard leaching tests, solidificates were exposed to atmospheric conditions during one year in order to determine the actual leaching level of metals in real environment. It can be concluded that the EN 12457-4 test is more similar to the real environmental conditions, while the TCLP test highly exaggerates the leaching of metals. The paper also presents results of differential acid neutralization (d-AN) analysis compared with mineralogical study done by scanning electron microscopy and X-ray diffraction analysis. The d-AN coupled with Eh-pH (Pourbaix) diagrams were proven to be a new effective method for analysis of amorphous solidified structure.

Effect of precipitation pattern on leaching of preservative from treated wood and implications for accelerated testing

Treesearch

Stan Lebow

2014-01-01

There is a need to develop improved accelerated test methods for evaluating the leaching of wood preservatives from treated wood exposed to precipitation. In this study the effects of rate of rainfall and length of intervals between rainfall events on leaching was evaluated by exposing specimens to varying patterns of simulated rainfall under controlled laboratory...

40 CFR 63.9020 - What performance tests and other procedures must I use?

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Hydrochloric Acid Production...) If you use a caustic scrubber control device or a water scrubber control device, the design...

The effect of lizardite surface characteristics on pyrite flotation

NASA Astrophysics Data System (ADS)

Feng, Bo; Feng, Qiming; Lu, Yiping

2012-10-01

The effect of lizardite surface characteristics on pyrite flotation has been investigated through flotation tests, adsorption tests, zeta potential measurements, FTIR study, X-ray photoelectron spectroscopy (XPS) and sedimentation tests. The flotation results show that at pH value 9, where flotation of nickel sulfide ores is routinely performed, two kinds of lizardite samples (native lizardite and leached lizardite) have different effects on the flotation of pyrite. The native lizardite adheres to the surface of pyrite and reduces pyrite flotation recovery while the leached lizardite does not interfere with pyrite flotation. Infrared analyses and XPS tests illustrate that acid leaching changed the surface characteristics of lizardite mineral and the leached lizardite has less magnesium on its surface. It has been determined that the electro-kinetic behavior of lizardite aqueous suspensions is mainly a function of the Mg/Si atomic ratio on lizardite surface. So, the low isoelectric point observed in the leached sample has been linked to values of this ratio lower than that of the native lizardite.

Organic compounds in concrete from demolition works.

PubMed

Van Praagh, M; Modin, H; Trygg, J

2015-11-01

This study aims to verify the effect of physically removing the outer surface of contaminated concrete on total contents and on potential mobility of pollutants by means of leaching tests. Reclaimed concrete from 3 industrial sites in Sweden were included: A tar impregnated military storage, a military tar track-depot, as well as concrete constructions used for disposing of pesticide production surplus and residues. Solid materials and leachates from batch and column leaching tests were analysed for metals, Cl, F, SO4, DOC and contents of suspected organic compounds (polycyclic aromatic hydrocarbons, PAH, and pesticides/substances for pesticide production such as phenoxy acids, chlorophenols and chlorocresols, respectively). In case of PAH contaminated concrete, results indicate that removing 1 or 5 mm of the surface lead to total concentrations below the Swedish guidelines for recycling of aggregates and soil in groundwork constructions. 3 out of 4 concrete samples contaminated with pesticides fulfilled Swedish guidelines for contaminated soil. Results from batch and column leaching tests indicated, however, that concentrations above environmental quality standards for certain PAH and phenoxy acids, respectively, might occur at site when the crushed concrete is recycled in groundwork constructions. As leaching tests engaged in the study deviated from leaching test standards with a limited number of samples, the potential impact of the leaching tests' equipment on measured PAH and pesticide leachate concentrations has to be evaluated in future work. Copyright © 2015. Published by Elsevier Ltd.

Leaching Properties of Naturally Occurring Heavy Metals from Soils

NASA Astrophysics Data System (ADS)

Zhang, M.; Hoshino, M.; Yoshikawa, M.; Hara, J.; Sugita, H.

2014-12-01

The major threats to human health from heavy metals are associated with exposure to arsenic, lead, cadmium, chromium, mercury, as well as some other elements. The effects of such heavy metals on human health have been extensively studied and reviewed by international organizations such as WHO. Due to their toxicity, heavy metal contaminations have been regulated by national environmental standards in many countries, and/or laws such as the Soil Contamination Countermeasures Act in Japan. Leaching of naturally occurring heavy metals from the soils, especially those around abandoned metal mines into surrounding water systems, either groundwater or surface water systems, is one of the major pathways of exposure. Therefore, understanding the leaching properties of toxic heavy metals from naturally polluted soils is of fundamentally importance for effectively managing abandoned metal mines, excavated rocks discharged from infrastructure constructions such as tunneling, and/or selecting a pertinent countermeasure against pollution when it is necessary. In this study, soil samples taken from the surroundings of abandoned metal mines in different regions in Japan were collected and analyzed. The samples contained multiple heavy metals such as lead, arsenic and chromium. Standard leaching test and sequential leaching test considering different forms of contaminants, such as trivalent and pentavalent arsenics, and trivalent and hexavalent chromiums, together with standard test for evaluating total concentration, X-ray Fluorescence Analysis (XRF), X-ray diffraction analysis (XRD) and Cation Exchange Capacity (CEC) tests were performed. In addition, sequential leaching tests were performed to evaluate long-term leaching properties of lead from representative samples. This presentation introduces the details of the above experimental study, discusses the relationships among leaching properties and chemical and mineral compositions, indicates the difficulties associated with remediation of naturally polluted sites, and emphasizes the importance of risk-based countermeasures against naturally occurring heavy metals. Keywords: Leaching properties, Control Factor, Naturally Occurring Heavy Metals, Lead, Arsenic, Chromium

Potentials of biological oxidation processes for the treatment of spent sulfidic caustics containing thiols.

PubMed

Sipma, Jan; Svitelskaya, Anna; van der Mark, Bart; Pol, Look W Hulshoff; Lettinga, Gatze; Buisman, Cees J N; Janssen, Albert J H

2004-12-01

This research focused on the biological treatment of sulfidic spent caustics from refineries, which contain mainly hydrogen sulfide, methanethiol (MT) and ethanethiol (ET). Also various organic compounds can be present such as BTEX. Biological oxidation of 2.5 mM MT in batch experiments occurred after MT was first auto-oxidized into dimethyldisulfide (DMDS) whereafter oxidation into sulfate was completed in 350 h. DMDS as sole substrate was completely oxidized within 40 h. Therefore, DMDS formation seems to play an important role in detoxification of MT. Biological oxidation of ET and buthanethiol was not successful in batch experiments. Complete oxidation of MT and ET was observed in flow-through reactor experiments. Simultaneous oxidation of sulfide and MT was achieved when treating a synthetic spent caustic, containing 10 mM sulfide and 2.5 mM MT, in a bubble column reactor with carrier material at a hydraulic retention time of 6 h. Addition of 7.5 mM phenol, a common pollutant of spent caustics, did not adversely affect the biological oxidation process and phenol was completely removed from the effluent. Finally, three different spent caustics solutions from refineries were successfully treated.

Geopolymerisation of fly ashes with waste aluminium anodising etching solutions.

PubMed

Ogundiran, M B; Nugteren, H W; Witkamp, G J

2016-10-01

Combined management of coal combustion fly ash and waste aluminium anodising etching solutions using geopolymerisation presents economic and environmental benefits. The possibility of using waste aluminium anodising etching solution (AES) as activator to produce fly ash geopolymers in place of the commonly used silicate solutions was explored in this study. Geopolymerisation capacities of five European fly ashes with AES and the leaching of elements from their corresponding geopolymers were studied. Conventional commercial potassium silicate activator-based geopolymers were used as a reference. The geopolymers produced were subjected to physical, mechanical and leaching tests. The leaching of elements was tested on 28 days cured and crushed geopolymers using NEN 12457-4, NEN 7375, SPLP and TCLP leaching tests. After 28 days ambient curing, the geopolymers based on the etching solution activator showed compressive strength values between 51 and 84 MPa, whereas the commercial potassium silicate based geopolymers gave compressive strength values between 89 and 115 MPa. Based on the regulatory limits currently associated with the used leaching tests, all except one of the produced geopolymers (with above threshold leaching of As and Se) passed the recommended limits. The AES-geopolymer geopolymers demonstrated excellent compressive strength, although less than geopolymers made from commercial activator. Additionally, they demonstrated low element leaching potentials and therefore can be suitable for use in construction works. Copyright © 2016. Published by Elsevier Ltd.

21 CFR 1230.40 - Required label information.

Code of Federal Regulations, 2010 CFR

2010-04-01

... FEDERAL CAUSTIC POISON ACT Imports § 1230.40 Required label information. Containers which are offered for...) (1), (2), and (3) of the Federal Caustic Poison Act and the directions for treatment in the case of...

21 CFR 1230.40 - Required label information.

Code of Federal Regulations, 2012 CFR

2012-04-01

... FEDERAL CAUSTIC POISON ACT Imports § 1230.40 Required label information. Containers which are offered for...) (1), (2), and (3) of the Federal Caustic Poison Act and the directions for treatment in the case of...

21 CFR 1230.40 - Required label information.

Code of Federal Regulations, 2014 CFR

2014-04-01

... FEDERAL CAUSTIC POISON ACT Imports § 1230.40 Required label information. Containers which are offered for...) (1), (2), and (3) of the Federal Caustic Poison Act and the directions for treatment in the case of...

21 CFR 1230.40 - Required label information.

Code of Federal Regulations, 2011 CFR

2011-04-01

... FEDERAL CAUSTIC POISON ACT Imports § 1230.40 Required label information. Containers which are offered for...) (1), (2), and (3) of the Federal Caustic Poison Act and the directions for treatment in the case of...

21 CFR 1230.40 - Required label information.

Code of Federal Regulations, 2013 CFR

2013-04-01

... FEDERAL CAUSTIC POISON ACT Imports § 1230.40 Required label information. Containers which are offered for...) (1), (2), and (3) of the Federal Caustic Poison Act and the directions for treatment in the case of...

Observation of the enhanced backscattering of light by the end of a tilted dielectric cylinder owing to the caustic merging transition

NASA Astrophysics Data System (ADS)

Marston, Philip L.; Zhang, Yibing; Thiessen, David B.

2003-01-01

The scattering of light by obliquely illuminated circular dielectric cylinders was previously demonstrated to be enhanced by a merger of Airy caustics at a critical tilt angle. [Appl. Opt. 37, 1534 (1998)]. A related enhancement is demonstrated here for backward and near-backward scattering for cylinders cut with a flat end perpendicular to the cylinder's axis. It is expected that merged caustics will enhance the backscattering by clouds of randomly oriented circular cylinders that have appropriately flat ends.

A Technique for Evaluating the Uncertainties in Path Loss Predictions Caused by Sparsely Sampled Terrain Data

DTIC Science & Technology

2013-06-26

Diomedi, thank you for providing support in getting through the writing. To my parents and Suzanne’s, thank you for tolerating the time we’ve spent here...the caustic distance idea from geometric optics, and will be shown to slightly improve the results. Following those results, antenna patterns will be...change in the caustic in the 3rd dimension, while MOMI has already accounted for it in the x-z plane. In geometric optics, the caustic is the point of

Evaluation of the impact of lime softening waste disposal in natural environments.

PubMed

Blaisi, Nawaf I; Roessler, Justin; Cheng, Weizhi; Townsend, Timothy; Al-Abed, Souhail R

2015-09-01

Drinking water treatment residues (WTR), generated from the lime softening processes, are commonly reused or disposed of in a number of applications; these include use as a soil amendment or a subsurface fill. Recently questions were posed by the Florida regulatory community on whether lime WTR that contained a small percentage of other treatment additives could appropriately be characterized as lime WTR, in terms of total element content and leachability. A study was done using a broad range of leaching tests, including a framework of tests recently adopted by the United States-Environmental Protection Agency (EPA) and tests that were modified to account for scenario specific conditions, such as the presence of natural organic matter (NOM). The results of these additional leaching tests demonstrated that certain applications, including disposal in a water body with NOM or in placement anaerobic environment, did result in increased leaching of elements such as Fe, and that a site specific assessment should be conducted prior to using WTR in these types of applications. This study illustrates the importance of leaching test selection when attempting to provide an estimation of release in practice. Although leaching tests are just one component in a beneficial use assessment and other factors including aquifer and soil properties play a significant role in the outcome, leaching tests should be tailored to most appropriately represent the scenario or reuse application being evaluated. Copyright © 2015 Elsevier Ltd. All rights reserved.

Potential for leaching of arsenic from excavated rock after different drying treatments.

PubMed

Li, Jining; Kosugi, Tomoya; Riya, Shohei; Hashimoto, Yohey; Hou, Hong; Terada, Akihiko; Hosomi, Masaaki

2016-07-01

Leaching of arsenic (As) from excavated rock subjected to different drying methods is compared using sequential leaching tests and rapid small-scale column tests combined with a sequential extraction procedure. Although the total As content in the rock was low (8.81 mg kg(-1)), its resulting concentration in the leachate when leached at a liquid-to-solid ratio of 10 L kg(-1) exceeded the environmental standard (10 μg L(-1)). As existed mainly in dissolved forms in the leachates. All of the drying procedures applied in this study increased the leaching of As, with freeze-drying leading to the largest increase. Water extraction of As using the two tests showed different leaching behaviors as a function of the liquid-to-solid ratio, and achieved average extractions of up to 35.7% and 25.8% total As, respectively. Dissolution of As from the mineral surfaces and subsequent re-adsorption controlled the short-term release of As; dissolution of Fe, Al, and dissolved organic carbon played important roles in long-term As leaching. Results of the sequential extraction procedure showed that use of 0.05 M (NH4)2SO4 underestimates the readily soluble As. Long-term water extraction removed almost all of the non-specifically sorbed As and most of the specifically sorbed As. The concept of pollution potential indices, which are easily determined by the sequential leaching test, is proposed in this study and is considered for possible use in assessing efficacy of treatment of excavated rocks. Copyright © 2016 Elsevier Ltd. All rights reserved.

Study of leaching mechanisms of caesium ions incorporated in Ordinary Portland Cement.

PubMed

Papadokostaki, Kyriaki G; Savidou, Anastasia

2009-11-15

In this work, a study of the leaching kinetics of Cs(+) ions from cement paste solids, containing inactive Cs(2)SO(4), is presented, involving (i) the parallel performance of leaching experiments at two temperatures (30 degrees C and 70 degrees C); (ii) the performance of leaching tests with intermediate changes in temperature between 30 degrees C and 70 degrees C; (iii) the use of specimens of two different thicknesses and (iv) the determination of the distribution of Cs(+) in the cement specimen at various stages of the leaching test. The results of leaching studies at 30 degrees C with cement solids simulating the composition of real radioactive wastes, containing NaNO(3), small amounts of inactive CsNO(3) and traces of (137)Cs(+) are also reported. Concentration profiles of Cs(+) in inactive specimens showed that part of the Cs(+) (20-30%) tends to be immobilized in the matrix, while elution of the readily leachable portion follows Fick's law reasonably well. No immobilized Cs(+) was detected in the samples containing considerable amounts of NaNO(3). Long-term leaching experiments (up to 8 years) revealed acceleration of the elution process (not detectable in short-term tests), attributable to increase in porosity caused by erosion of the cement matrix. Sorption experiments of Cs(+) ions by cement granules indicated that adsorption on cement pore surfaces is not significant. On the other hand, the leaching tests at two different temperatures or with intermediate changes in temperature between 30 degrees C and 70 degrees C, yielded activation energies that indicated a more complicated kinetic behavior.

Monitoring caustic injuries from emergency department databases using automatic keyword recognition software.

PubMed

Vignally, P; Fondi, G; Taggi, F; Pitidis, A

2011-03-31

In Italy the European Union Injury Database reports the involvement of chemical products in 0.9% of home and leisure accidents. The Emergency Department registry on domestic accidents in Italy and the Poison Control Centres record that 90% of cases of exposure to toxic substances occur in the home. It is not rare for the effects of chemical agents to be observed in hospitals, with a high potential risk of damage - the rate of this cause of hospital admission is double the domestic injury average. The aim of this study was to monitor the effects of injuries caused by caustic agents in Italy using automatic free-text recognition in Emergency Department medical databases. We created a Stata software program to automatically identify caustic or corrosive injury cases using an agent-specific list of keywords. We focused attention on the procedure's sensitivity and specificity. Ten hospitals in six regions of Italy participated in the study. The program identified 112 cases of injury by caustic or corrosive agents. Checking the cases by quality controls (based on manual reading of ED reports), we assessed 99 cases as true positive, i.e. 88.4% of the patients were automatically recognized by the software as being affected by caustic substances (99% CI: 80.6%- 96.2%), that is to say 0.59% (99% CI: 0.45%-0.76%) of the whole sample of home injuries, a value almost three times as high as that expected (p < 0.0001) from European codified information. False positives were 11.6% of the recognized cases (99% CI: 5.1%- 21.5%). Our automatic procedure for caustic agent identification proved to have excellent product recognition capacity with an acceptable level of excess sensitivity. Contrary to our a priori hypothesis, the automatic recognition system provided a level of identification of agents possessing caustic effects that was significantly much greater than was predictable on the basis of the values from current codifications reported in the European Database.

Leaching of CCA-treated wood: implications for waste disposal.

PubMed

Townsend, Timothy; Tolaymat, Thabet; Solo-Gabriele, Helena; Dubey, Brajesh; Stook, Kristin; Wadanambi, Lakmini

2004-10-18

Leaching of arsenic, chromium, and copper from chromated copper arsenate (CCA)-treated wood poses possible environmental risk when disposed. Samples of un-weathered CCA-treated wood were tested using a variety of the US regulatory leaching procedures, including the toxicity characteristic leaching procedure (TCLP), synthetic precipitation leaching procedure (SPLP), extraction procedure toxicity method (EPTOX), waste extraction test (WET), multiple extraction procedure (MEP), and modifications of these procedures which utilized actual MSW landfill leachates, a construction and demolition (C and D) debris leachate, and a concrete enhanced leachate. Additional experiments were conducted to assess factors affecting leaching, such as particle size, pH, and leaching contact time. Results from the regulatory leaching tests provided similar results with the exception of the WET, which extracted greater quantities of metals. Experiments conducted using actual MSW leachate, C and D debris leachate, and concrete enhanced leachate provided results that were within the same order of magnitude as results obtained from TCLP, SPLP, and EPTOX. Eleven of 13 samples of CCA-treated dimensional lumber exceeded the US EPA's toxicity characteristic (TC) threshold for arsenic (5 mg/L). If un-weathered arsenic-treated wood were not otherwise excluded from the definition of hazardous waste, it frequently would require management as such. When extracted with simulated rainwater (SPLP), 9 of the 13 samples leached arsenic at concentrations above 5 mg/L. Metal leachability tended to increase with decreasing particle size and at pH extremes. All three metals leached above the drinking water standards thus possibly posing a potential risk to groundwater. Arsenic is a major concern from a disposal point of view with respect to ground water quality.

21 CFR 1230.36 - Hearings; when not provided for.

Code of Federal Regulations, 2011 CFR

2011-04-01

... FEDERAL CAUSTIC POISON ACT Administrative Procedures § 1230.36 Hearings; when not provided for. No hearing... Caustic Poison Act (44 Stat. 1409; 15 U.S.C. 408) in reporting a violation direct to the United States...

21 CFR 1230.36 - Hearings; when not provided for.

Code of Federal Regulations, 2013 CFR

2013-04-01

... FEDERAL CAUSTIC POISON ACT Administrative Procedures § 1230.36 Hearings; when not provided for. No hearing... Caustic Poison Act (44 Stat. 1409; 15 U.S.C. 408) in reporting a violation direct to the United States...

21 CFR 1230.36 - Hearings; when not provided for.

Code of Federal Regulations, 2010 CFR

2010-04-01

... FEDERAL CAUSTIC POISON ACT Administrative Procedures § 1230.36 Hearings; when not provided for. No hearing... Caustic Poison Act (44 Stat. 1409; 15 U.S.C. 408) in reporting a violation direct to the United States...

21 CFR 1230.36 - Hearings; when not provided for.

Code of Federal Regulations, 2014 CFR

2014-04-01

... FEDERAL CAUSTIC POISON ACT Administrative Procedures § 1230.36 Hearings; when not provided for. No hearing... Caustic Poison Act (44 Stat. 1409; 15 U.S.C. 408) in reporting a violation direct to the United States...

21 CFR 1230.36 - Hearings; when not provided for.

Code of Federal Regulations, 2012 CFR

2012-04-01

... FEDERAL CAUSTIC POISON ACT Administrative Procedures § 1230.36 Hearings; when not provided for. No hearing... Caustic Poison Act (44 Stat. 1409; 15 U.S.C. 408) in reporting a violation direct to the United States...

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

Serne, R. Jeffrey; Lanigan, David C.; Westsik, Joseph H.

This revision to the original report adds two longer term leach sets of data to the report and provides more discussion and graphics on how to interpret the results from long-term laboratory leach tests. The leach tests were performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate the release of key constituents from monoliths of Cast Stone prepared with four simulated low-activity waste (LAW) liquid waste streams.

Microlensing as a possible probe of event-horizon structure in quasars

NASA Astrophysics Data System (ADS)

Tomozeiu, Mihai; Mohammed, Irshad; Rabold, Manuel; Saha, Prasenjit; Wambsganss, Joachim

2018-04-01

In quasars which are lensed by galaxies, the point-like images sometimes show sharp and uncorrelated brightness variations (microlensing). These brightness changes are associated with the innermost region of the quasar passing through a complicated pattern of caustics produced by the stars in the lensing galaxy. In this paper, we study whether the universal properties of optical caustics could enable extraction of shape information about the central engine of quasars. We present a toy model with a crescent-shaped source crossing a fold caustic. The silhouette of a black hole over an accretion disc tends to produce roughly crescent sources. When a crescent-shaped source crosses a fold caustic, the resulting light curve is noticeably different from the case of a circular luminosity profile or Gaussian source. With good enough monitoring data, the crescent parameters, apart from one degeneracy, can be recovered.

Microlensing as a Possible Probe of Event-Horizon Structure in Quasars

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

Tomozeiu, Mihai; Mohammed, Irshad; Rabold, Manuel

In quasars which are lensed by galaxies, the point-like images sometimes show sharp and uncorrelated brightness variations (microlensing). These brightness changes are associated with the innermost region of the quasar passing through a complicated pattern of caustics produced by the stars in the lensing galaxy. In this paper, we study whether the universal properties of optical caustics could enable extraction of shape information about the central engine of quasars. We present a toy model with a crescent-shaped source crossing a fold caustic. The silhouette of a black hole over an accretion disk tends to produce roughly crescent sources. When amore » crescent-shaped source crosses a fold caustic, the resulting light curve is noticeably different from the case of a circular luminosity profile or Gaussian source. With good enough monitoring data, the crescent parameters, apart from one degeneracy, can be recovered.« less

Microlensing as a Possible Probe of Event-Horizon Structure in Quasars

DOE PAGES

Tomozeiu, Mihai; Mohammed, Irshad; Rabold, Manuel; ...

2017-12-08

In quasars which are lensed by galaxies, the point-like images sometimes show sharp and uncorrelated brightness variations (microlensing). These brightness changes are associated with the innermost region of the quasar passing through a complicated pattern of caustics produced by the stars in the lensing galaxy. In this paper, we study whether the universal properties of optical caustics could enable extraction of shape information about the central engine of quasars. We present a toy model with a crescent-shaped source crossing a fold caustic. The silhouette of a black hole over an accretion disk tends to produce roughly crescent sources. When amore » crescent-shaped source crosses a fold caustic, the resulting light curve is noticeably different from the case of a circular luminosity profile or Gaussian source. With good enough monitoring data, the crescent parameters, apart from one degeneracy, can be recovered.« less

Heavy metal removal by caustic-treated yeast immobilized in alginate

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

Lu, Y.; Wilkins, E.

1995-12-31

Saccharomyces cerevisiae yeast biomass was treated with hot alkali to increase its biosorption capacity for heavy metals and then was immobilized in alginate gel. Biosorption capacities for Cu{sup 2+}, Cd{sup 2+}, and Zn{sup 2+} on alginate gel, native yeast, native yeast immobilized in alginate gel, and caustic-treated yeast immobilized in alginate gel were all compared. Immobilized yeasts could be reactivated and reused in a manner similar to the ion exchange resins. Immobilized caustic-treated yeast has high heavy metal biosorption capacity and high metal removal efficiency in a rather wide acidic pH region. The biosorption isotherm of immobilized caustic-treated yeast wasmore » studied, and empirical equations were obtained. The initial pH of polluted water affected the metal removal efficiency significantly, and the equilibrium biosorption capacity seemed to be temperature independent at lower initial metal concentrations.« less

Prediction of sonic boom at a focus

NASA Technical Reports Server (NTRS)

Plotkin, K. J.; Cantril, J. M.

1976-01-01

The behavior of sonic boom at a focus has been reviewed for the purpose of extending present sonic boom computational methods to include focal zones. The geometry of a focal zone - whether a smooth caustic, a cusped caustic, or a perfect focus to a point - determines the character of focused signatures. The seeming contradiction of various experimental data can be resolved by noting these differences. A ray acoustic analysis has been developed for quantitative determination of caustic geometry. The only reliable theory presently available for signatures at a focus is for a smooth caustic. There has been some controversy between theoretical and experimental values of a constant in the scaling law for this case. It has been found that this discrepancy can be resolved by accounting for the finite thickness of real sonic boom shock waves. These findings have been incorporated into an existing sonic boom computer program.

Leaching characteristics of selected South African fly ashes: Effect of pH on the release of major and trace species

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

Gitari, W.M.; Fatoba, O.O.; Petrik, L.F.

2009-07-01

Fly ash samples from two South African coal-fired power stations were subjected to different leaching tests under alkaline and acidic conditions in an attempt to assess the effect of pH on the leachability of species from the fly ashes and also assess the potential impact of the fly ashes disposal on groundwater and the receiving environment. To achieve this, German Standard leaching (DIN-S4) and Acid Neutralization Capacity (ANC) tests were employed. Ca, Mg, Na, K and SO{sub 4} were significantly leached into solution under the two leaching conditions with the total amounts in ANC leachates higher than that of DIN-S4.more » This indicates that a large fraction of the soluble salts in unweathered fly ash are easily leached. These species represents the fraction that can be flushed off initially from the surface of ash particles on contacting the ash with water. The amounts of toxic trace elements such as As, Se, Cd, Cr and Pb leached out of the fly ashes when in contact with de-mineralized water (DIN-S4 test) were low and below the Target Water Quality Range (TWQR) of South Africa. This is explained by their low concentrations in the fly ashes and their solubility dependence on the pH of the leaching solution. However the amounts of some minor elements such as B, Mn, Fe, As and Se leached out at lower pH ranging between 10 to 4 (ANC test) were slightly higher than the TWQR, an indication that the pH of the leaching solution plays a significant role on the leaching of species in fly ash. The high concentrations of the toxic elements released from the fly ashes at lower pH gives an indication that the disposal of the fly ash could have adverse effects on the receiving environment if the pH of the solution contacting the ashes is not properly monitored.« less

The Evolution of Current Command Relationships in Amphibious Operations Doctrine

DTIC Science & Technology

2013-04-08

post World War I British Empire. They pressed on, however, despite extremely limited funding and inability to test their doctrine, and spent much...The levels of cooperation that exist are now firmly cemented in the minds of those in uniform today and the caustic service in-fighting for

Improvement of nuclide leaching resistance of paraffin waste form with low density polyethylene.

PubMed

Kim, Chang Lak; Park, Joo Wan; Kim, Ju Youl; Chung, Chang Hyun

2002-01-01

Low-level liquid borate wastes have been immobilized with paraffin wax using a concentrate waste drying system (CWDS) in Korean nuclear power plants. The possibility for improving chemical durability of paraffin waste form was suggested in this study. A small amount of low density polyethylene (LDPE) was added to increase the leaching resistance of the existing paraffin waste form. The influence of LDPE on the leaching behavior of waste form was investigated by performing leaching test according to ANSI/ANS-16.1 procedure during 325 days. It was observed that the leaching of nuclides immobilized within paraffin waste form made a marked reduction although little content of LDPE was added to waste form. The acceptance criteria of paraffin waste form associated with leachability index (LI) and compressive strength after the leaching test were fully satisfied with the help of LDPE.

Comparison of leaching characteristics of heavy metals from bottom and fly ashes in Korea and Japan.

PubMed

Shim, Young-Sook; Rhee, Seung-Whee; Lee, Woo-Keun

2005-01-01

The objective of this research was to compare the leaching characteristics of heavy metals such as cadmium, chromium, copper, nickel, lead, etc., in Korean and Japanese municipal solid waste incineration (MSWI) ash. The rate of leaching of heavy metal was measured by KSLT and JTL-13, and the amount of heavy metals leached was compared with the metal content in each waste component. Finally, bio-availability testing was performed to assess the risks associated with heavy metals leached from bottom ash and fly ash. From the results, the value of neutralization ability in Japanese fly ash was four times higher than that in Korean fly ash. The reason was the difference in the content of Ca(OH)(2) in fly ash. The amount of lead leached exceeded the regulatory level in both Japanese and Korean fly ash. The rate of leaching was relatively low in ash with a pH in the range of 6-10. The bio-availability test in fly ash demonstrated that the amount of heavy metals leached was Pb>Cd>Cr, but the order was changed to Pb>Cr>Cd in the bottom ash. The leaching concentration of lead exceeded the Japanese risk level in all fly ashes from the two countries, but the leaching concentration of cadmium exceeded the regulatory level in Korean fly ash only.

Assessment risk of phosphorus leaching from calcareous soils using soil test phosphorus.

PubMed

Jalali, Mohsen; Jalali, Mahdi

2017-03-01

Accurate estimation of phosphorus (P) leaching is important because excess P may reduce surface and ground water quality. Little attention has been paid to estimate P leaching from soil tests in calcareous soils. The relation between different soil tests P (STP), P sorption index (PSI) and degree of P saturation (DPS) and leaching of P were examined for assessing the risk of P loss from calcareous soils. Columns leaching repacked with native soils were leached with either distilled water or 10 mM CaCl 2 solutions, separately. Four leaching events were performed at four days, and 28.7 mm of distilled water or 10 mM CaCl 2 solutions was applied at each leaching events. Compared with distilled water, CaCl 2 had a small ability to solubilize P from soils. Concentration of P in leachate in both leaching solutions was exceeding 0.1 mg l -1 associated with eutrophication. Cumulative P leached P was ranged from 0.17 to 18.59 mg P kg -1 and 0.21-8.16 mg P kg -1 , when distilled water and 10 mM CaCl 2 solutions were applied, respectively and it was higher in sandy clay loam soils compared with clay soils. Among evaluated environmental soil P tests, P CaCl2-3h (P extracted by 10 mM CaCl 2 for 3 h), P CaCl2-1h (P extracted by 10 mM CaCl 2 for 1 h) were more accurate than other soil P tests for predicting P concentration in the leachates in both leaching solutions and accounting for 83% and 72% of variation of P concentration, respectively. The water extractable P (WEP) (r = 0.771) and Olsen-P (P Ols )(r = 0.739) were significantly related to the leached P concentration using distilled water solution in a split line model, with a change point of 27.4 mg P kg -1 and 61.5 mg P kg -1 , respectively. Various DPS were calculated and related to the leached P concentration. Based on P extracted by Mehlich-3 (P M3 ) and HCl (P HCl ) and PSI, the change point of the relationship between leached P concentration and DPS M3-3 (P M3 (P M3 +PSI)×100) and DPS HCl-2 (P HCl (P HCl +PSI)×100) for both leaching solutions was approximately the same, thus a mean value of 49% for DPS M3-3 and 73% for DPS HCl-2 was obtained. Soils were grouped into four categories of increasing P leaching potential based on WEP, P Ols , and DPS M3-3 . The results indicated that 8.00%-25.50% of the soil grouped in no risk category whereas 8.00%-13.70% of the soils fell into the high risk category. Copyright © 2016 Elsevier Ltd. All rights reserved.

Intrinsic scatter of caustic masses and hydrostatic bias: An observational study

NASA Astrophysics Data System (ADS)

Andreon, S.; Trinchieri, G.; Moretti, A.; Wang, J.

2017-10-01

All estimates of cluster mass have some intrinsic scatter and perhaps some bias with true mass even in the absence of measurement errors for example caused by cluster triaxiality and large scale structure. Knowledge of the bias and scatter values is fundamental for both cluster cosmology and astrophysics. In this paper we show that the intrinsic scatter of a mass proxy can be constrained by measurements of the gas fraction because masses with higher values of intrinsic scatter with true mass produce more scattered gas fractions. Moreover, the relative bias of two mass estimates can be constrained by comparing the mean gas fraction at the same (nominal) cluster mass. Our observational study addresses the scatter between caustic (I.e., dynamically estimated) and true masses, and the relative bias of caustic and hydrostatic masses. For these purposes, we used the X-ray Unbiased Cluster Sample, a cluster sample selected independently from the intracluster medium content with reliable masses: 34 galaxy clusters in the nearby (0.050 < z < 0.135) Universe, mostly with 14 < log M500/M⊙ ≲ 14.5, and with caustic masses. We found a 35% scatter between caustic and true masses. Furthermore, we found that the relative bias between caustic and hydrostatic masses is small, 0.06 ± 0.05 dex, improving upon past measurements. The small scatter found confirms our previous measurements of a highly variable amount of feedback from cluster to cluster, which is the cause of the observed large variety of core-excised X-ray luminosities and gas masses.

UTEX LEACHING, THICKENING AND FILTRATION TESTS. Topical Report

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

Stanley, A.; George, D.R.; Thomas, P.N.

1954-03-15

A series of leaching, thickening, and filtration tests was undertaken to determine minimum conditions for high uranium extractions and obtain thickening and filtration data. The ore represented by the sample responded to cold and hot leaching with the minimum condition for uranium extraction being 500 pounds of H/ sub 2/SO/sub 4/ per ton and five pounds NaClO/sub 3/ per ton leached at room temperature for l6 hours with uranium extraction of over 95%. Thickening and filtration were economical if a reagent such as S-3000 or Guar gum was used. (auth)

Leaching behavior and chemical stability of copper butyl xanthate complex under acidic conditions.

PubMed

Chang, Yi Kuo; Chang, Juu En; Chiang, Li Choung

2003-08-01

Although xanthate addition can be used for treating copper-containing wastewater, a better understanding of the leaching toxicity and the stability characteristics of the copper xanthate complexes formed is essential. This work was undertaken to evaluate the leaching behavior of copper xanthate complex precipitates by means of toxicity characteristics leaching procedure (TCLP) and semi-dynamic leaching test (SDLT) using 1 N acetic acid solution as the leachant. Also, the chemical stability of the copper xanthate complex during extraction has been examined with the studying of variation of chemical structure using UV-vis, Fourier transform infrared and X-ray photoelectron spectroscopies (XPS). Both TCLP and SDLT results showed that a negligible amount of copper ion was leached out from the copper xanthate complex precipitate, indicating that the complex exhibited a high degree of copper leaching stability under acidic conditions. Nevertheless, chemical structure of the copper xanthate complex precipitate varied during the leaching tests. XPS data suggested that the copper xanthate complex initially contained both cupric and cuprous xanthate, but the unstable cupric xanthate change to the cuprous form after acid extraction, indicating the cuprous xanthate to be the final stabilizing structure. Despite that, the changes of chemical structure did not induce the rapid leaching of copper from the copper xanthate complex.

LEACHING OF CCA-TREATED WOOD: IMPLICATIONS FOR WASTE DISPOSAL

EPA Science Inventory

Leaching of arsenic, chromium, and copper from chromated copper arsenate (CCA)-treated wood poses possible environmental risk when disposed. Samples of un-weathered CCA-treated wood were tested using a variety of US regulatory leaching procedures, including the toxicity character...

Leaching characteristics of copper flotation waste before and after vitrification.

PubMed

Coruh, Semra; Ergun, Osman Nuri

2006-12-01

Copper flotation waste from copper production using a pyrometallurgical process contains toxic metals such as Cu, Zn, Co and Pb. Because of the presence of trace amounts of these highly toxic metals, copper flotation waste contributes to environmental pollution. In this study, the leaching characteristics of copper flotation waste from the Black Sea Copper Works in Samsun, Turkey have been investigated before and after vitrification. Samples obtained from the factory were subjected to toxicity tests such as the extraction procedure toxicity test (EP Tox), the toxicity characteristic leaching procedure (TCLP) and the "method A" extraction procedure of the American Society of Testing and Materials. The leaching tests showed that the content of some elements in the waste before vitrification exceed the regulatory limits and cannot be disposed of in the present form. Therefore, a stabilization or inertization treatment is necessary prior to disposal. Vitrification was found to stabilize heavy metals in the copper flotation waste successfully and leaching of these metals was largely reduced. Therefore, vitrification can be an acceptable method for disposal of copper flotation waste.

Study on the leaching behavior of actinides from nuclear fuel debris

NASA Astrophysics Data System (ADS)

Kirishima, Akira; Hirano, Masahiko; Akiyama, Daisuke; Sasaki, Takayuki; Sato, Nobuaki

2018-04-01

For the prediction of the leaching behavior of actinides contained in the nuclear fuel debris generated by the Fukushima Daiichi nuclear power plant accident in Japan, simulated fuel debris consisting of a UO2-ZrO2 solid solution doped with 137Cs, 237Np, 236Pu, and 241Am tracers was synthesized and investigated. The synthesis of the debris was carried out by heat treatment at 1200 °C at different oxygen partial pressures, and the samples were subsequently used for leaching tests with Milli-Q water and seawater. The results of the leaching tests indicate that the leaching of actinides depends on the redox conditions under which the debris was generated; for example, debris generated under oxidative conditions releases more actinide nuclides to water than that generated under reductive conditions. Furthermore, we found that, as Zr(IV) increasingly substituted U(IV) in the fluorite crystal structure of the debris, the actinide leaching from the debris decreased. In addition, we found that seawater leached more actinides from the debris than pure water, which seems to be caused by the complexation of actinides by carbonate ions in seawater.

Investigations of metal leaching from mobile phone parts using TCLP and WET methods.

PubMed

Yadav, Satyamanyu; Yadav, Sudesh

2014-11-01

Metal leaching from landfills containing end-of-life or otherwise discarded mobile phones poses a threat to the environment as well as public health. In the present study, the metal toxicity of printed wire boards (PWBs), plastics, liquid crystal displays (LCDs) and batteries of mobile phones was assessed using the Toxicity Characteristics Leaching Procedures (TCLP) and the Waste Extraction Test (WET). The PWBs failed TCLP for Pb and Se, and WET for Pb and Zn. In WET, the two PWB samples for Pb and Zn and the battery samples for Co and Cu failed the test. Furthermore, the PWBS for Ni and the battery samples for Ni and Co failed the WET in their TCLP leachates. Both, Ni and Co are the regulatory metals in only WET and not covered under TCLP. These observations indicate that the TCLP seems to be a more aggressive test than the WET for the metal leaching from the mobile phone parts. The compositional variations, nature of leaching solution (acetate in TCLP and citrate in WET) and the redox conditions in the leaching solution of the PWBs resulted in different order of metals with respect to their amounts of leaching from PWBs in TCLP (Fe > Pb > Zn > Ni > Co > Cu) and WET (Zn > Fe > Ni > Pb > Cu). The metal leaching also varied with the make, manufacturing year and part of the mobile phone tested. PWBs, plastics and batteries should be treated as hazardous waste. Metal leaching, particularly of Se and Pb, from mobile phones can be harmful to the environment and human health. Therefore, a scientifically sound and environmentally safe handling and disposal management system needs to be evolved for the mobile phone disposal. Copyright © 2014 Elsevier Ltd. All rights reserved.

Weatherability and leach resistance of wood impregnated with nano-zinc oxide

Treesearch

Carol A. Clausen; Frederick Green; S. Nami Kartal

2010-01-01

Southern pine specimens vacuum-treated with nano-zinc oxide (nano-ZnO) dispersions were evaluated for leach resistance and UV protection. Virtually, no leaching occurred in any of the nano-ZnO–treated specimens in a laboratory leach test, even at the highest retention of 13 kg/m3. However, specimens treated with high concentrations of nano-ZnO...

METAL RECOVERY/REMOVAL USING NON-ELECTROLYTIC METAL RECOVERY

EPA Science Inventory

Radiator repair shops most commonly use hot caustic solutions to clean radiator sections prior to resoldering. he hot caustic, or "boil-out" solutions as they are cabled in the trade, become contaminated with dirt, rust flakes, paint flakes and miscellaneous particulate debris. n...

21 CFR 1230.20 - General guaranty.

Code of Federal Regulations, 2011 CFR

2011-04-01

... CAUSTIC POISON ACT Guaranty § 1230.20 General guaranty. In lieu of a particular guaranty for each lot of... to _____ are not misbranded within the meaning of the Federal Caustic Poison Act. (Date) (Signature... Poison Act. (Date) (Signature and address of manufacturer or wholesaler) ...

21 CFR 1230.20 - General guaranty.

Code of Federal Regulations, 2010 CFR

2010-04-01

... CAUSTIC POISON ACT Guaranty § 1230.20 General guaranty. In lieu of a particular guaranty for each lot of... to _____ are not misbranded within the meaning of the Federal Caustic Poison Act. (Date) (Signature... Poison Act. (Date) (Signature and address of manufacturer or wholesaler) ...

21 CFR 1230.20 - General guaranty.

Code of Federal Regulations, 2012 CFR

2012-04-01

... CAUSTIC POISON ACT Guaranty § 1230.20 General guaranty. In lieu of a particular guaranty for each lot of... to _____ are not misbranded within the meaning of the Federal Caustic Poison Act. (Date) (Signature... Poison Act. (Date) (Signature and address of manufacturer or wholesaler) ...

21 CFR 1230.20 - General guaranty.

Code of Federal Regulations, 2013 CFR

2013-04-01

... CAUSTIC POISON ACT Guaranty § 1230.20 General guaranty. In lieu of a particular guaranty for each lot of... to _____ are not misbranded within the meaning of the Federal Caustic Poison Act. (Date) (Signature... Poison Act. (Date) (Signature and address of manufacturer or wholesaler) ...

21 CFR 1230.20 - General guaranty.

Code of Federal Regulations, 2014 CFR

2014-04-01

... CAUSTIC POISON ACT Guaranty § 1230.20 General guaranty. In lieu of a particular guaranty for each lot of... to _____ are not misbranded within the meaning of the Federal Caustic Poison Act. (Date) (Signature... Poison Act. (Date) (Signature and address of manufacturer or wholesaler) ...

Biocatalytic and chemical leaching of a low-grade nickel laterite ore

NASA Astrophysics Data System (ADS)

Ciftci, Hasan; Atik, Suleyman; Gurbuz, Fatma

2018-04-01

Nickel and cobalt recovery from a low-grade nickel laterite ore, supplied from Çaldağ deposit (Manisa, Turkey) were investigated by bio and chemical leaching processes. The fungus, Aspergillus niger was used for biocatalytic leaching experiments. The effects of parameters (solid ratio and sucrose concentration) on the biocatalytic leaching of the ore were initially tested in flasks to obtain the optimum conditions for the A. niger. Then chemical leaching was applied as a comparison to bioleaching, using organic acids (citric, oxalic, acetic and gluconic acids) as well as a mixture of acids. According the results, the maximum dissolution yield of nickel, cobalt and iron were detected respectively as 95.3%, 74.3% and 50.0% by biocatalytic processes which containing 25% (w/v) sucrose and 1% (w/v) solids. The increase in the solid ratio adversely influenced the biocatalytic activity of A. niger. Finally, further tests in reactors (v = 1 and 10 L) were performed using the optimum conditions from the flask tests. The difference in metals recovery between biocatalytic and chemical leaching was significantly important. Bioleaching produced higher Ni and Co extractions (34.3-75.6%) than chemical process.

The public health impact of pediatric caustic ingestion injuries.

PubMed

Johnson, Christopher M; Brigger, Matthew T

2012-12-01

To determine the current public health burden of injuries due to caustic ingestion in children. The 2009 Kids' Inpatient Database provides data on a sample of all pediatric hospital discharges in the United States during that year. Children with caustic ingestion injuries requiring hospitalization were identified by corresponding codes from the International Classification of Diseases, Ninth Revision. Database analysis generated national estimates of summary statistics. A national database. Representative sample of all hospital discharge data on patients 18 years or younger. Public health burden related to caustic injury, including potential factors related to admission outcome, the necessity of a procedure during the admission, admission length of stay, and total charges for the admission. We estimated the prevalence of pediatric caustic ingestion injuries requiring hospitalization in the United States in 2009 to be 807 (95% CI, 731-882) children. The annual economic burden was estimated at $22 900 000 (95% CI, $15 400 000-$30 400 000) in total hospital charges. The mean charge per patient was estimated at $28 860 (95% CI, $19 799-$37 922) with a median of $9848. The mean length of admission was 4.13 (95% CI, 3.22-5.03) days with a median of 2 days. Among the 807 patients, 45.3% underwent esophagoscopy, and those admitted to teaching hospitals were more likely to undergo a procedure during their stay (P = .02). Logistic regression models suggested significant median income (P < .001) and sex (P < .001) variations. The current public health burden of pediatric caustic ingestion injuries may be less than commonly cited. This finding supports the notion that legislative efforts have been successful. Despite these successes, these injuries continue to impose a significant burden on health care resources.

Statistics of Microlensing Caustic Crossings in Q 2237+0305: Peculiar Velocity of the Lens Galaxy and Accretion Disk Size

NASA Astrophysics Data System (ADS)

Mediavilla, E.; Jimenez-Vicente, J.; Muñoz, J. A.; Mediavilla, T.; Ariza, O.

2015-01-01

We use the statistics of caustic crossings induced by microlensing in the lens system Q 2237+0305 to study the lens galaxy peculiar velocity. We calculate the caustic crossing rates for a comprehensive family of stellar mass functions and find a dependence of the average number of caustic crossings with the effective transverse velocity and the average mass, < n > \\propto {veff / \\sqrt{< m > }}, equivalent to the theoretical prediction for the case of microlenses with identical masses. We explore the possibilities of the method to measure v eff using the ~12 yr of Optical Gravitational Lensing Experiment monitoring of the four images of Q 2237+0305. To determine a lower limit for v eff, we count, conservatively, a single caustic crossing for each one of the four high magnification events identified in the literature (plus one additional proposed by us) obtaining veff ≳ 240\\sqrt{< m > /0.17 M_⊙ } km s-1 at 68% of confidence. From this value and the average FWHM of the four high magnification events, we obtain a lower limit of rs ≳ 1.4 \\sqrt{< m > /0.17 M_⊙ } light-days for the radius of the source (rs = FWHM/2.35). Tentative identification of three additional caustic crossing events leads to estimates of veff≃ (493+/- 246)\\sqrt{< m > /0.17 M_⊙ } km s-1 for the effective transverse velocity and of rs ≃ (2.7+/- 1.3)\\sqrt{< m > /0.17 M_⊙ } light-days for the source size. The estimated transverse peculiar velocity of the galaxy is vt ≃ (429+/- 246)\\sqrt{< m > /0.17 M_⊙ } km s-1.

Wild capuchin monkeys adjust stone tools according to changing nut properties.

PubMed

Luncz, Lydia V; Falótico, Tiago; Pascual-Garrido, Alejandra; Corat, Clara; Mosley, Hannah; Haslam, Michael

2016-09-14

Animals foraging in their natural environments need to be proficient at recognizing and responding to changes in food targets that affect accessibility or pose a risk. Wild bearded capuchin monkeys (Sapajus libidinosus) use stone tools to access a variety of nut species, including otherwise inaccessible foods. This study tests whether wild capuchins from Serra da Capivara National Park in Brazil adjust their tool selection when processing cashew (Anacardium spp.) nuts. During the ripening process of cashew nuts, the amount of caustic defensive substance in the nut mesocarp decreases. We conducted field experiments to test whether capuchins adapt their stone hammer selection to changing properties of the target nut, using stones of different weights and two maturation stages of cashew nuts. The results show that although fresh nuts are easier to crack, capuchin monkeys used larger stone tools to open them, which may help the monkeys avoid contact with the caustic hazard in fresh nuts. We demonstrate that capuchin monkeys are actively able to distinguish between the maturation stages within one nut species, and to adapt their foraging behaviour accordingly.

Wild capuchin monkeys adjust stone tools according to changing nut properties

PubMed Central

Luncz, Lydia V.; Falótico, Tiago; Pascual-Garrido, Alejandra; Corat, Clara; Mosley, Hannah; Haslam, Michael

2016-01-01

Animals foraging in their natural environments need to be proficient at recognizing and responding to changes in food targets that affect accessibility or pose a risk. Wild bearded capuchin monkeys (Sapajus libidinosus) use stone tools to access a variety of nut species, including otherwise inaccessible foods. This study tests whether wild capuchins from Serra da Capivara National Park in Brazil adjust their tool selection when processing cashew (Anacardium spp.) nuts. During the ripening process of cashew nuts, the amount of caustic defensive substance in the nut mesocarp decreases. We conducted field experiments to test whether capuchins adapt their stone hammer selection to changing properties of the target nut, using stones of different weights and two maturation stages of cashew nuts. The results show that although fresh nuts are easier to crack, capuchin monkeys used larger stone tools to open them, which may help the monkeys avoid contact with the caustic hazard in fresh nuts. We demonstrate that capuchin monkeys are actively able to distinguish between the maturation stages within one nut species, and to adapt their foraging behaviour accordingly. PMID:27624672

Experimental investigation of influence of acid rain on leaching and hydraulic characteristics of cement-based solidified/stabilized lead contaminated clay.

PubMed

Du, Yan-Jun; Jiang, Ning-Jun; Shen, Shui-Long; Jin, Fei

2012-07-30

Remediation of contaminated lands in China urban areas is of great concern. Degradation of construction facilities caused by acid rain is a serious environmental pollution issue in China. This paper presents an investigation of the effects of acid rain on leaching and hydraulic properties of cement-based solidified/stabilized lead contaminated soil. Laboratory tests including infiltration test and soaking test are conducted. It is found that the soil hydraulic conductivity decreases with increase in the pore volume of flow of permeant liquids (acid rain and distilled water). The decreasing rate in the case of the acid rain is lower than that in the case of the distilled water. The soaking test results show that pH and the presence of sulfate ions of acid rain have considerable influence on the leached concentrations and leaching rate of calcium. Copyright © 2012 Elsevier B.V. All rights reserved.

Maximum availability and mineralogical control of chromium released from AOD slag.

PubMed

Li, Junguo; Liu, Bao; Zeng, Yanan; Wang, Ziming; Gao, Zhiyuan

2017-03-01

AOD (argon oxygen decarburization) slag is the by-product in the stainless steel refining process. Chromium existing in AOD slag can leach out and probably poses a serious threat to the environment. To assess the leaching toxicity of chromium released from AOD slag, the temperature-dependent maximum availability leaching test was performed. To determine the controlling mineralogical phases of chromium released from AOD slag, a Visual MINTEQ simulation was established based on Vminteq30 and the FactSage 7.0 database. The leaching tests indicated that the leaching availability of chromium was slight and mainly consisted of trivalent chromium. Aging of AOD slag under the atmosphere can oxidize trivalent chromium to hexavalent chromium, which could be leached out by rainwater. According to the simulation, the chromium concentration in leachates was controlled by the freely soluble pseudo-binary phases in the pH = 7.0 leaching process and controlled by the Cr 2 O 3 phase in the pH = 4.0 leaching process. Chromium concentrations were underestimated when the controlling phases were determined to be FeCr 2 O 4 and MgCr 2 O 4 . Facilitating the generation of the insoluble spinel-like phases during the cooling and disposal process of the molten slag could be an effective approach to decreasing the leaching concentration of chromium and its environmental risk.

Heavy metals in urban soils of East St. Louis, IL. Part II: Leaching characteristics and modeling.

PubMed

Kaminski, M D; Landsberger, S

2000-09-01

The city of East St. Louis, IL, has a history of abundant industrial activities including smelters of ferrous and non-ferrous metals, a coal-fired power plant, companies that produced organic and inorganic chemicals, and petroleum refineries. Following a gross assessment of heavy metals in the community soils (see Part I of this two-part series), leaching tests were performed on specific soils to elucidate heavy metal-associated mineral fractions and general leachability. Leaching experiments, including the Toxicity Characteristic Leaching Procedure (TLCP) and column tests, and sequential extractions, illustrated the low leachability of metals in East St. Louis soils. The column leachate results were modeled using a formulation developed for fly ash leaching. The importance of instantaneous dissolution was evident from the model. By incorporating desorption/adsorption terms into the source term, the model was adapted very well to the time-dependent heavy metal leachate concentrations. The results demonstrate the utility of a simple model to describe heavy metal leaching from contaminated soils.

Heavy Metals in Urban Soils of East St. Louis, IL Part II: Leaching Characteristics and Modeling.

PubMed

Kaminski, Michael D; Landsberger, Sheldon

2000-09-01

The city of East St. Louis, IL, has a history of abundant industrial activities including smelters of ferrous and non-ferrous metals, a coal-fired power plant, companies that produced organic and inorganic chemicals, and petroleum refineries. Following a gross assessment of heavy metals in the community soils (see Part I of this two-part series), leaching tests were performed on specific soils to elucidate heavy metal-associated mineral fractions and general leachability. Leaching experiments, including the Toxicity Characteristic Leaching Procedure (TLCP) and column tests, and sequential extractions, illustrated the low leachability of metals in East St. Louis soils. The column leachate results were modeled using a formulation developed for fly ash leaching. The importance of instantaneous dissolution was evident from the model. By incorporating desorption/adsorption terms into the source term, the model was adapted very well to the time-dependent heavy metal leachate concentrations. The results demonstrate the utility of a simple model to describe heavy metal leaching from contaminated soils.

Production report: enhanced recovery. [Combustion, steam, soak steam drive, polymer and caustic, micellar/surfactant miscible hydrocarbons and CO/sub 2/

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

Noran, D.

Schemes for producing additional oil using enhanced-recovery (ER) methods are under way throughout the world. The extent and intensity of ER activity is highest in the U.S. with 156 projects, about two-thirds of which are thermal. Venezuela has a strong ER commitment with at least 70 active projects, with a major thrust on steam soak. Significant projects, but limited in number, are under way in Canada, North Africa, Southeast Asia, and elsewhere in Latin America. A breakdown of active U.S. ER projects for 1970, 1973, and 1975 is tabulated for combustion, steam soak, steam drive, polymer and caustic, micellar/surfactant, misciblemore » hydrocarbon, and CO/sub 2/ methods. This Oil and Gas Journal Survey includes seven articles; the first six were prepared by David Noran, Journal Production Editor. The final article on Venezuelan activity was written by Alvaro Franco, Editor and Publisher, Petroleo Internacional. The articles are entitled: U.S. Thermal Recovery Activity Growing Steadily; Operators Accelerate Testing of Micellar/Surfactant Potential; Polymer and Caustic Methods on Rebound; Gas Miscible Projects Move at Slow Pace; Canadian Enhanced-Recovery Activity Moderate, Centers on Thermal Projects; Other Global Enhanced-Recovery Work Sparse; and Thermal Work Humming in Venezuela. Detailed information on each method is tabulated for each article. (MCW)« less

The influence of pH on the leaching behaviour of inorganic components from municipal solid waste APC residues

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

Quina, Margarida J.; Bordado, Joao C.M.; Quinta-Ferreira, Rosa M.

2009-09-15

The influence of pH on the leaching behaviour of air pollution control (APC) residues produced in municipal solid waste incineration (MSWI) is addressed in this study. The residue is considered hazardous waste, and in accordance with their chemical properties, the leaching of contaminants into the environment is the main concern. Several leaching tests can be used for research studies or regulatory purposes, where a wide variety of conditions may be tested. Our work deals mainly with the leaching behaviour of toxic heavy metals (Pb, Cd, Zn, Cr, Ni, Cu) and inorganics associated with soluble salts (Na, K, Ca, Cl). Themore » main goal is to obtain an overview of the leachability of APC residues produced in a Portuguese MSWI process. Among the different variables that may have influence on the leaching behaviour, pH of the leachant solution is the most important one, and was evaluated through pH static tests. The acid neutralization capacity (ANC) of the residue was also determined, which is in the range of 6.2-6.8 meq g{sup -1} (for pH = 7) and 10.1-11.6 meq g{sup -1} (for pH = 4). The analysis of the leaching behaviour is particularly important when the leaching is solubility controlled. The amphoteric behaviour of some elements was observed, namely for Pb and Zn, which is characterized through high solubilization at low and high pH and moderate or low solubility at neutral or moderate high pH. The solubility curves for Pb, Cd, Zn, Cr, Ni and Cu as a function of pH were obtained, which are very useful for predicting the leaching behaviour in different scenarios. The solubility of K and Na reveals to be nearly independent of the solution pH and the released amount is mainly availability-controlled. Moreover, the pH static test showed that Cl{sup -} is the most pH-independent species. The APC residue turns out to be a hazardous waste because of the high leaching of lead and chloride. On the other hand, leaching of elements like cadmium, nickel and copper is limited by the high pH of the residue, and as long as the waste keeps its ANC, the risk of mobilization of these elements is low.« less

Use of short-term (5-Minute) and long-term (18-Hour) leaching tests to characterize, fingerprint, and rank mine-waste material from historical mines in the Deer Creek, Snake River, and Clear Creek Watersheds in and around the Montezuma Mining District, Colorado

USGS Publications Warehouse

Hageman, Philip L.

2004-01-01

Precipitation-induced runoff from historical mine-waste located adjacent to the headwaters of the Snake River, Deer Creek, Saints John Creek, Grizzly Gulch, Stevens Gulch, and Leavenworth Creek contributes to the degradation of water quality in these streams. Because historical mine-waste piles have had long-term exposure to the atmosphere, it is surmised that runoff from these piles, induced by meteorological events such as cloudbursts and snowmelt, may cause mobility of acid and metals into a watershed due to dissolution of soluble minerals. For this study, 13 mine-waste composite samples from various mine-wastes in these drainage basins were leached using both a short-term and a long-term leach test. Analytical results from this combination of leach tests are tools that allow the investigator to quantify (fingerprint) which geochemical components could be expected in runoff from these piles if they were leached by a cloudburst (5-minute leach test), as well as what the ?worst-case? geochemical profile would look like if the material were subject to extended leaching and breakdown of the mine-waste material (18-hour leach test). Also, this combination of leach tests allows the geoscientist the ability to see geochemical changes in the mine-waste leachate over time. That is, does the leachate become more or less acidic over time; does the specific conductance increase or decrease; and are there changes in the concentrations of major or trace elements? Further, use of a ranking scheme described herein will aid in prediction of which historical mine-waste piles have the greatest potential for impact on a watershed should runoff occur. Because of long-term weathering of these historical mine-waste piles, geochemical profiles, leachate time-trends, and relative ranking of the mine-wastes produced from analysis of the leachates are Hageman_SIR_2508.doc 1 7/21/2004 2:50 PM indicative of how the mine-waste piles can be expected to act in the environment and may help to identify the ?bad actors??this may aid in understanding the reasons for water-quality differences between the drainages.

Aluminum Target Dissolution in Support of the Pu-238 Program

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

McFarlane, Joanna; Benker, Dennis; DePaoli, David W

2014-09-01

Selection of an aluminum alloy for target cladding affects post-irradiation target dissolution and separations. Recent tests with aluminum alloy 6061 yielded greater than expected precipitation in the caustic dissolution step, forming up to 10 wt.% solids of aluminum hydroxides and aluminosilicates. We present a study to maximize dissolution of aluminum metal alloy, along with silicon, magnesium, and copper impurities, through control of temperature, the rate of reagent addition, and incubation time. Aluminum phase transformations have been identified as a function of time and temperature, using X-ray diffraction. Solutions have been analyzed using wet chemical methods and X-ray fluorescence. These datamore » have been compared with published calculations of aluminum phase diagrams. Temperature logging during the transients has been investigated as a means to generate kinetic and mass transport data on the dissolution process. Approaches are given to enhance the dissolution of aluminum and aluminosilicate phases in caustic solution.« less

Alternative Sodium Recovery Technology—High Hydroxide Leaching: FY10 Status Report

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

Mahoney, Lenna A.; Neiner, Doinita; Peterson, Reid A.

2011-02-04

Boehmite leaching tests were carried out at NaOH concentrations of 10 M and 12 M, temperatures of 85°C and 60°C, and a range of initial aluminate concentrations. These data, and data obtained during earlier 100°C tests using 1 M and 5 M NaOH, were used to establish the dependence of the boehmite dissolution rate on hydroxide concentration, temperature, and initial aluminate concentration. A semi-empirical kinetic model for boehmite leaching was fitted to the data and used to calculate the NaOH additions required for leaching at different hydroxide concentrations. The optimal NaOH concentration for boehmite leaching at 85°C was estimated, basedmore » on minimizing the amount of Na that had to be added in NaOH to produce a given boehmite conversion.« less

Leaching of Arsenic from Granular Ferric Hydroxide Residuals under Mature Landfill Conditions

PubMed Central

Ghosh, Amlan; Mukiibi, Muhammed; Sáez, A. Eduardo; Ela, Wendell P.

2008-01-01

Most arsenic bearing solid residuals (ABSR) from water treatment will be disposed in non-hazardous landfills. The lack of an appropriate leaching test to predict arsenic mobilization from ABSR creates a need to evaluate the magnitude and mechanisms of arsenic release under landfill conditions. This work studies the leaching of arsenic and iron from a common ABSR, granular ferric hydroxide, in a laboratory-scale column that simulates the biological and physicochemical conditions of a mature, mixed solid waste landfill. The column operated for approximately 900 days and the mode of transport as well as chemical speciation of iron and arsenic changed with column age. Both iron and arsenic were readily mobilized under the anaerobic, reducing conditions. During the early stages of operation, most arsenic and iron leaching (80% and 65%, respectively) was associated with suspended particulate matter and iron was lost proportionately faster than arsenic. In later stages, while the rate of iron leaching declined, the arsenic leaching rate increased greater than 7-fold. The final phase was characterized by dissolved species leaching. Future work on the development of standard batch leaching tests should take into account the dominant mobilization mechanisms identified in this work: solid associated transport, reductive sorbent dissolution, and microbially mediated arsenic reduction. PMID:17051802

Leaching of arsenic from granular ferric hydroxide residuals under mature landfill conditions.

PubMed

Ghosh, Amlan; Mukiibi, Muhammed; Sáez, A Eduardo; Ela, Wendell P

2006-10-01

Most arsenic bearing solid residuals (ABSR) from water treatment will be disposed in nonhazardous landfills. The lack of an appropriate leaching test to predict arsenic mobilization from ABSR creates a need to evaluate the magnitude and mechanisms of arsenic release under landfill conditions. This work studies the leaching of arsenic and iron from a common ABSR, granular ferric hydroxide, in a laboratory-scale column that simulates the biological and physicochemical conditions of a mature, mixed solid waste landfill. The column operated for approximately 900 days and the mode of transport as well as chemical speciation of iron and arsenic changed with column age. Both iron and arsenic were readily mobilized under the anaerobic, reducing conditions. During the early stages of operation, most arsenic and iron leaching (80% and 65%, respectively) was associated with suspended particulate matter, and iron was lost proportionately faster than arsenic. In later stages, while the rate of iron leaching declined, the arsenic leaching rate increased greater than 7-fold. The final phase was characterized by dissolved species leaching. Future work on the development of standard batch leaching tests should take into account the dominant mobilization mechanisms identified in this work: solid associated transport, reductive sorbent dissolution, and microbially mediated arsenic reduction.

Reducing acid leaching of manganiferous ore: effect of the iron removal operation on solid waste disposal.

PubMed

De Michelis, Ida; Ferella, Francesco; Beolchini, Francesca; Vegliò, Francesco

2009-01-01

The process of reducing acid leaching of manganiferous ore is aimed at the extraction of manganese from low grade manganese ores. This work is focused on the iron removal operation. The following items have been considered in order to investigate the effect of the main operating conditions on solid waste disposal and on the process costs: (i) type and quantity of the base agent used for iron precipitation, (ii) effective need of leaching waste separation prior to the iron removal operation, (iii) presence of a second leaching stage with the roasted ore, which might also act as a preliminary iron removal step, and (iv) effect of tailings washing on the solid waste classification. Different base compounds have been tested, including CaO, CaCO3, NaOH, and Na2CO3. The latter gave the best results concerning both the precipitation process kinetics and the reagent consumption. The filtration of the liquor leach prior to iron removal was not necessary, implying significant savings in capital costs. A reduction of chemical consumption and an increase of manganese concentration in the solution were obtained by introducing secondary leaching tests with the previously roasted ore; this additional step was introduced without a significant decrease of global manganese extraction yield. Finally, toxicity characteristic leaching procedure (TCLP) tests carried out on the leaching solid waste showed: (i) a reduction of arsenic mobility in the presence of iron precipitates, and (ii) the need for a washing step in order to produce a waste that is classifiable as not dangerous, taking into consideration the existing Environmental National Laws.

Process for the disposal of alkali metals

DOEpatents

Lewis, Leroy C.

1977-01-01

Large quantities of alkali metals may be safely reacted for ultimate disposal by contact with a hot concentrated caustic solution. The alkali metals react with water in the caustic solution in a controlled reaction while steam dilutes the hydrogen formed by the reaction to a safe level.

Treatment of olefin plant spent caustic by combination of neutralization and Fenton reaction.

PubMed

Sheu, S H; Weng, H S

2001-06-01

Spent caustic from olefin plants contains much H2S and some mercaptans, phenols and oil. A new treatment process of spent caustic by neutralization followed by oxidation with Fenton's reagent (Fe2+/H2O2) was successfully developed. Over 90% of dissolved H2S were converted to gas phase by neutralization at pH = 5 and T = 70 degrees, and the vent gas stream could be introduced to sulfur recovery plant. The neutralized liquid was oxidized with OH. free radical, which was provided by a Fenton's reagent. The residual sulfides in the neutralized spent caustic were oxidized to less than 0.1 mg/L. The total COD removal of spent caustic is over 99.5% and the final COD value of the effluent can be lower than 100 mg/L under the following oxidation conditions: reaction time = 50 min, T = 90 degrees, Fe2+ = 100 mg/L, and a stoichiometric H2O2/COD = 1.1. The value is better than the 800 mg/L value obtained by common WAO process. The optimum pH of the Fenton reaction is around 2 for this process, and the oxidation step can maintain a pH value in the range of 1.8-2.4. Moreover, the iron catalyst can be recycled without affecting process effectiveness thus preventing secondary pollution.

Leaching of lead from computer printed wire boards and cathode ray tubes by municipal solid waste landfill leachates.

PubMed

Jang, Yong-Chul; Townsend, Timothy G

2003-10-15

The proper management of discarded electronic devices (E-waste) is an important issue for solid waste professionals because of the magnitude of the waste stream and because these devices often contain a variety of toxic metals (e.g., lead). While recycling of E-waste is developing, much of this waste stream is disposed in landfills. Leaching tests are frequently used to characterize the potential of a solid waste to leach when disposed in a landfill. In the United States, the Toxicity Characteristic Leaching Procedure (TCLP) is used to determine whether a solid waste is a hazardous waste by the toxicity characteristic. The TCLP is designed to simulate worse-case leaching in a landfill environment where the waste is co-disposed with municipal solid waste (MSW). While the TCLP is a required analysis from a regulatory perspective, the leachate concentrations measured may not accurately reflect the concentrations observed under typical landfill conditions. Another method that can be performed to assess the degree a pollutant might leach from a waste in a landfill is to use actual landfill leachate as the leaching solution. In this study, two lead-containing components found in electronic devices (printed wire boards from computers and cathode ray tubes from computers and televisions) were leached using the TCLP and leachates from 11 Florida landfills. California's Waste Extraction Test (WET) and the Synthetic Precipitation Leaching Procedure were also performed. The results indicated that the extractions using MSW landfill leachates resulted in lower lead concentrations than those by the TCLP. The pH of the leaching solution and the ability of the organic acids in the TCLP and WET to complex with the lead are factors that regulate the amount of lead leached.

Evaluation of environmental compatibility of EAFD using different leaching standards.

PubMed

Sebag, M G; Korzenowski, C; Bernardes, A M; Vilela, A C

2009-07-30

A study on laboratory scale to evaluate the environmental compatibility of electric arc furnace dust (EAFD) is reported in this article. EAFD, a waste by-product of the steel-making process, was generated on a steel plant located in Brazil. Different leaching tests, NBR10005 (Brazilian), AFNORX31-210 (French), JST-13 (Japanese), DIN38414-S4 (German), TCLP (American), and NEN 7343 (Netherland) were conducted. These leaching procedures are batch tests and are columns conducted in a way that an equilibrium condition should be achieved. The pH of the medium showed a crucial parameter governing the release of metals from the solid phase into solution. As the pH of the medium varies with the leachant used, this determines the dissolution of the elements. Zn, Pb, Mn, Cd, and Cu presented high leachability at NBR10005 procedures (acid pH). Except Pb and Cr, the leachability of all others metals in leaching tests with alkaline pH decreases with the increase of the pH. NBR10005 classifies the EAFD as a hazardous waste due to high concentration of Pb and Cd in leachate. The column tests are presented in the following order of leaching: Pb>Cr>Zn>Mn>Cu>Cd.

Presence and leaching of bisphenol a (BPA) from dental materials.

PubMed

Becher, Rune; Wellendorf, Hanne; Sakhi, Amrit Kaur; Samuelsen, Jan Tore; Thomsen, Cathrine; Bølling, Anette Kocbach; Kopperud, Hilde Molvig

2018-01-01

BPA has been reported to leach from some resin based dental restorative materials and materials used for orthodontic treatment. To confirm and update previous findings, especially in light of the new temporary lower threshold value for tolerable daily BPA intake, we have investigated the leaching of BPA from 4 composite filling materials, 3 sealants and 2 orthodontic bonding materials. The materials were either uncured and dissolved in methanol or cured. The cured materials were kept in deionized water for 24 hours or 2 weeks. Samples were subsequently analyzed by ultra-performance liquid chromatography coupled to mass spectrometry (UPLC-MS-MS). The composite filling material Tetric EvoFlow ® and the fissure sealant DELTON ® showed significantly higher levels of BPA leaching compared to control samples for all test conditions (uncured, 24 h leaching and 2 weeks leaching). There were no significant differences in amount of leached BPA for any of the tested materials after 24 hours compared to 2 weeks. These results show that BPA is still released from some dental materials despite the general concern about potential adverse effects of BPA. However, the amounts of BPA were relatively low and most likely represent a very small contribution to the total BPA exposure.

Leaching from solid waste incineration ashes used in cement-treated base layers for pavements.

PubMed

Cai, Z; Bager, Dirch H; Christensen, T H

2004-01-01

Waste incineration bottom ash and treated flue gas cleaning products mixed with 2.5% of cement (50 kg/m3) were tested in the laboratory in terms of compressive strength and tank leaching tests over a 64-day period. Although the material displayed lower mechanical strength than a reference concrete, the strength still was sufficient for use as a base layer for roads. The metal content in the incineration-residue-based specimens was up to 100 times higher than in the reference concrete, suggesting that the mixed waste incineration residue should be used only for dedicated purposes. The leaching of Cl and Na was increased by a factor of 20-100 from the incineration-residue-based specimens as compared to the reference, while the leaching of K, Ca and SO4 was increased by a factor of 2-10. The leaching of heavy metals was also higher from the incineration-residue-based specimens than from the reference with respect to Cu (50 times), Cd, Pb and Zn (5 times), but not with respect to Cr and Ni. The leaching curves did only allow for a closer evaluation of the leaching process in a few cases. The physical retention of the constituents seemed to be the same in the reference as in the incineration-residue-based specimens. Heavy metal leaching was limited by enhanced chemical retention in the incineration-residue-specimens as compared to the reference. Since no quality criteria in terms of leaching from a monolithic material are currently available, the leaching issue must be evaluated case by case.

40 CFR 63.8184 - What parts of my plant does this subpart cover?

Code of Federal Regulations, 2014 CFR

2014-07-01

... in the manufacture of product chlorine, product caustic, and by-product hydrogen at a plant site. This subpart covers mercury emissions from by-product hydrogen streams, end box ventilation system vents, and fugitive emission sources associated with cell rooms, hydrogen systems, caustic systems, and...

40 CFR 63.8184 - What parts of my plant does this subpart cover?

Code of Federal Regulations, 2011 CFR

2011-07-01

... in the manufacture of product chlorine, product caustic, and by-product hydrogen at a plant site. This subpart covers mercury emissions from by-product hydrogen streams, end box ventilation system vents, and fugitive emission sources associated with cell rooms, hydrogen systems, caustic systems, and...

40 CFR 63.8184 - What parts of my plant does this subpart cover?

Code of Federal Regulations, 2012 CFR

2012-07-01

... in the manufacture of product chlorine, product caustic, and by-product hydrogen at a plant site. This subpart covers mercury emissions from by-product hydrogen streams, end box ventilation system vents, and fugitive emission sources associated with cell rooms, hydrogen systems, caustic systems, and...

40 CFR 63.8184 - What parts of my plant does this subpart cover?

Code of Federal Regulations, 2013 CFR

2013-07-01

... in the manufacture of product chlorine, product caustic, and by-product hydrogen at a plant site. This subpart covers mercury emissions from by-product hydrogen streams, end box ventilation system vents, and fugitive emission sources associated with cell rooms, hydrogen systems, caustic systems, and...

Leaching and geochemical behavior of fired bricks containing coal wastes.

PubMed

Taha, Yassine; Benzaazoua, Mostafa; Edahbi, Mohamed; Mansori, Mohammed; Hakkou, Rachid

2018-03-01

High amounts of mine wastes are continuously produced by the mining industry all over the world. Recycling possibility of some wastes in fired brick making has been investigated and showed promising results. However, little attention is given to the leaching behavior of mine wastes based fired bricks. The objective of this paper is to evaluate the geochemical behavior of fired bricks containing different types of coal wastes. The leachates were analyzed for their concentration of As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Zn and sulfates using different leaching tests; namely Tank Leaching tests (NEN 7375), Toxicity Characteristic Leaching Procedure (TCLP) and pH dependence test (EPA, 1313). The results showed that the release of constituents of potential interest was highly reduced after thermal treatment and were immobilized within the glassy matrix of the fired bricks. Moreover, it was also highlighted that the final pH of all fired samples changed and stabilized around 8-8.5 when the initial pH of leaching solution was in the range 2.5-11.5. The release of heavy metals and metalloids (As) tended to decrease with the increase of pH from acidic to alkaline solutions while Mo displayed a different trend. Copyright © 2017 Elsevier Ltd. All rights reserved.

Leaching characteristics of polybrominated diphenyl ethers (PBDEs) from flame-retardant plastics.

PubMed

Kim, Yong-Jin; Osako, Masahiro; Sakai, Shin-ichi

2006-10-01

To investigate the effect of leachant on the leachability of polybrominated diphenyl ethers (PBDEs), we determined the leaching concentrations of PBDEs from flame-retardant plastic samples (TV housings and raw materials before molding processing) that are regarded as a source of PBDEs in landfill sites. The leachants used were distilled water, 20% methanol solution, and dissolved humic solution (DHS) of 1000 mg/l based on organic carbon. The leaching test conditions were a liquid-to-solid ratio of 100:1, and a contact period of five days, with twice-daily agitation in a temperature-controlled room of 30 degrees C without pH or ionic strength control. The leaching concentrations of PBDEs increased with increased content, and were found to be remarkably enhanced when methanol and DHS were used instead of distilled water. The enhancement of leachability in the presence of the latter was attributed to the cosolvency effect, and complex formations between the PBDEs and dissolved humic matter (DHM). PBDE concentrations in the leachate obtained from the leaching test and an actual landfill site revealed a significant presence of congeners below heptabromodiphenyl ethers (H7BDEs), detected in the leachate of the actual landfill, while significant amounts of nonabromodiphenyl ethers (N9BDEs) and decabromodiphenyl ether (D10BDE) were detected in the leachate of the leaching test.

FIELD QUALITY CONTROL STRATEGIES ASSESSING SOLIDIFICATION/STABILIZATION

EPA Science Inventory

Existing regulatory mobility reduction (leaching) tests are not amenable to real time quality control because of the time required to perform sample extraction and chemical analysis. This is of conccern because the leaching test is the most important parameter used to relate trea...

Implementation of the Leaching Environmental Assessment ...

EPA Pesticide Factsheets

LEAF provides a uniform and integrated approach for evaluating leaching from solid materials (e.g., waste, treated wastes such as by solidification/stabilization, secondary materials such as blast furnace slags, energy residuals such as coal fly ash, soil, sediments, mining and mineral processing wastes). Assessment using LEAF applies a stepwise approach that considers the leaching behavior of COPCs in response to chemical and physical factors that control and material properties across a range of plausible field conditions (US EPA, 2010). The framework provides the flexibility to tailor testing to site conditions and select the extent of testing based on assessment objectives and the level of detailed information needed to support decision-making. The main focus will be to discuss the implementation of LEAF in the US and the How to Guide that has recently been completed. To present the How To Guide for the implementation of the leaching environmental assessment framework to an international audience already familiar with comparable leaching tests in use in Europe. Will be meeting with European colleagues on their interest in expanding methods to include organics.

Cadmium telluride leaching behavior: Discussion of Zeng et al. (2015).

PubMed

Sinha, Parikhit

2015-11-01

Zeng et al. (2015) evaluate the leaching behavior and surface chemistry of II-VI semiconductor materials, CdTe and CdSe, in response to pH and O2. Under agitation in acidic and aerobic conditions, the authors found approximately 3.6%-6.4% (w/w) solubility of Cd content in CdTe in the Toxicity Characteristic Leaching Procedure (TCLP), Waste Extraction Test (WET), and dissolution test, with lower solubility (0.56-0.58%) under agitation in acidic and anoxic conditions. This range is comparable with prior long-term transformation and dissolution testing and bio-elution testing of CdTe (2.3%-4.1% w/w solubility of Cd content in CdTe). The implications for potential leaching behavior of CdTe-containing devices require further data. Since CdTe PV modules contain approximately 0.05% Cd content by mass, the starting Cd content in the evaluation of CdTe-containing devices would be lower by three orders of magnitude than the starting Cd content in the authors' study, and leaching potential would be further limited by the monolithic glass-adhesive laminate-glass structure of the device that encapsulates the semiconductor material. Experimental evaluation of leaching potential of CdTe PV modules crushed by landfill compactor has been conducted, with results of TCLP and WET tests on the crushed material below regulatory limits for Cd. CdTe PV recycling technology has been in commercial operation since 2005 with high yields for semiconductor (95%) and glass (90%) recovery. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparative evaluation of short-term leach tests for heavy metal release from mineral processing waste

USGS Publications Warehouse

Al-Abed, S. R.; Hageman, P.L.; Jegadeesan, G.; Madhavan, N.; Allen, D.

2006-01-01

Evaluation of metal leaching using a single leach test such as the Toxicity Characteristic Leaching Procedure (TCLP) is often questionable. The pH, redox potential (Eh), particle size and contact time are critical variables in controlling metal stability, not accounted for in the TCLP. This paper compares the leaching behavior of metals in mineral processing waste via short-term extraction tests such as TCLP, Field Leach Test (FLT) used by USGS and deionized water extraction tests. Variation in the extracted amounts was attributed to the use of different particle sizes, extraction fluid and contact time. In the controlled pH experiments, maximum metal extraction was obtained at acidic pH for cationic heavy metals such as Cu, Pb and Zn, while desorption of Se from the waste resulted in high extract concentrations in the alkaline region. Precipitation of iron, caused by a pH increase, probably resulted in co-precipitation and immobilization of Cu, Pb and Zn in the alkaline pH region. A sequential extraction procedure was performed on the original waste and the solid residue from the Eh-pH experiments to determine the chemical speciation and distribution of the heavy metals. In the as-received waste, Cu existed predominantly in water soluble or sulfidic phases, with no binding to carbonates or iron oxides. Similar characteristics were observed for Pb and Zn, while Se existed mostly associated with iron oxides or sulfides. Adsorption/co-precipitation of Cu, Se and Pb on precipitated iron hydroxides was observed in the experimental solid residues, resulting in metal immobilization above pH 7.

Environmental impact of ferrochrome slag in road construction.

PubMed

Lind, B B; Fällman, A M; Larsson, L B

2001-01-01

Vargon Alloys in Western Sweden is one of the largest producers of ferrochrome slag in Europe. Ferrochrome slag is a by-product from the production of ferrochrome, an essential component in stainless steel. Extensive tests have been carried out on the physical properties of the ferrochrome slag from Vargon Alloys and it was found to be highly suitable as road construction material. The composition and leaching tests of the ferrochrome slag show that the chromium content is high, 1-3%, although leaching under normal conditions is very low. With the exception of potassium (K), which had a potential leaching capacity (availability test) of around 16%, the leaching of chromium, nickel, zinc and other elements was just a few per cent. However, all these tests were conducted in the laboratory. What happens out in the field, under the influence of acid rain and biological activity, and how does this compare with the laboratory results? To answer this question an investigation was carried out to study the environmental impact of ferrochrome slag in roads that were built in 1994. The investigation includes soil sampling (total content and leachable amounts of metals) and groundwater analysis (filtered and non-filtered samples). In addition, a new method involving the bio-uptake of chromium and other metals by the roots of the dandelion (Taraxacum officinale) was tested. The results show that there was a low migration of particles from the slag to the underlying soil and that the leaching into the groundwater was also low for all the elements analysed. However, there seemed to be a significant uptake of Cr by plants growing with their roots in the slag. An investigation of plant uptake was an important complement to laboratory leaching tests on alternative materials.

Analysis of an MCU HEPA filter

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

Peters, T. B.; Fondeur, F. F.

A series of direct analyses on three portions (inlet, center, and outlet) of the High Efficiency Particulate Air (HEPA) filter material from the Modular Caustic-Side Solvent Extraction Unit (MCU) have been performed; this includes x-ray methods such as X-Ray Diffraction (XRD), Contained Scanning Electron Microscopy (CSEM) and X-Ray Fluorescence (XRF), as well as Fourier Transform InfraRed spectroscopy (FTIR). Additionally, two leaching studies (one with water, one with dichloromethane) have been performed on three portions (inlet, center, and outlet) of the HEPA filter material, with the leachates being analyzed by Inductively-coupled plasma emission spectroscopy (ICPES), Semi-Volatile Organic Analysis (SVOA) and gammascan.more » From the results of the analyses, SRNL feels that cesium-depleted solvent is being introduced into the HEPA filter. The most likely avenue for this is mechanical aerosolization of solvent, where the aerosol is then carried along an airstream into the HEPA filter. Once introduced into the HEPA filter media, the solvent wicks throughout the material, and migrates towards the outlet end. Once on the outlet end, continual drying could cause particulate flakes to exit the filter and travel farther down the airstream path.« less

Statistical comparison of leaching behavior of incineration bottom ash using seawater and deionized water: Significant findings based on several leaching methods.

PubMed

Yin, Ke; Dou, Xiaomin; Ren, Fei; Chan, Wei-Ping; Chang, Victor Wei-Chung

2018-02-15

Bottom ashes generated from municipal solid waste incineration have gained increasing popularity as alternative construction materials, however, they contains elevated heavy metals posing a challenge for its free usage. Different leaching methods are developed to quantify leaching potential of incineration bottom ashes meanwhile guide its environmentally friendly application. Yet, there are diverse IBA applications while the in situ environment is always complicated, challenging its legislation. In this study, leaching tests were conveyed using batch and column leaching methods with seawater as opposed to deionized water, to unveil the metal leaching potential of IBA subjected to salty environment, which is commonly encountered when using IBA in land reclamation yet not well understood. Statistical analysis for different leaching methods suggested disparate performance between seawater and deionized water primarily ascribed to ionic strength. Impacts of leachant are metal-specific dependent on leaching methods and have a function of intrinsic characteristics of incineration bottom ashes. Leaching performances were further compared on additional perspectives, e.g. leaching approach and liquid to solid ratio, indicating sophisticated leaching potentials dominated by combined geochemistry. It is necessary to develop application-oriented leaching methods with corresponding leaching criteria to preclude discriminations between different applications, e.g., terrestrial applications vs. land reclamation. Copyright © 2017 Elsevier B.V. All rights reserved.

The pH-dependent leaching behavior of slags from various stages of a copper smelting process: Environmental implications.

PubMed

Jarošíková, Alice; Ettler, Vojtěch; Mihaljevič, Martin; Kříbek, Bohdan; Mapani, Ben

2017-02-01

The leaching behaviors of primary copper (Cu) slags originating from Ausmelt, reverbatory, and converter furnaces operating under a single technological process were compared to a residual slag tailing obtained by slag re-processing via flotation and metal recovery. The EN 12457-2 leaching test, used for assessment of the hazardous properties, was followed by the CEN/TS 14997 pH-static leaching test (pH range 3-12). Both leaching experiments were coupled with a mineralogical investigation of the primary and secondary phases as well as geochemical modeling. Metals (Cd, Cu, Pb, Zn) exhibit the highest leaching at low pH. Under acidic conditions (pH 3-6), Ausmelt slag and slag tailing exhibited higher metal leaching compared to other slag types. Very low leaching of metals (far below EU limits for non-hazardous waste) was observed at natural pH (7.9-9.0) for all the studied slag samples. In contrast, relatively high leaching of As was observed over the entire pH range, especially for Ausmelt slag (exceeding the EU limit for hazardous waste by 1.7×). However, geochemical modeling and scanning electron microscopy indicated that formation of stable Ca-Cu-Pb arsenates and the binding of As to newly formed Fe (oxyhydr)oxides play an important role in efficient As immobilization at the slag-water interface. In contrast, no controls were predicted for Sb, whose leaching was almost pH-independent. Nevertheless Sb leached concentrations at natural pH were below EU limit for hazardous waste. Re-processing of primary Cu slags for metal recovery, and subsequent co-disposal of the resulting slag tailing with dolomite-rich mine tailing and local laterite is suitable for stabilizing the remaining contaminants (except Sb) and limiting their leaching into the environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reducing acid leaching of manganiferous ore: Effect of the iron removal operation on solid waste disposal

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

De Michelis, Ida; Ferella, Francesco; Beolchini, Francesca

2009-01-15

The process of reducing acid leaching of manganiferous ore is aimed at the extraction of manganese from low grade manganese ores. This work is focused on the iron removal operation. The following items have been considered in order to investigate the effect of the main operating conditions on solid waste disposal and on the process costs: (i) type and quantity of the base agent used for iron precipitation, (ii) effective need of leaching waste separation prior to the iron removal operation, (iii) presence of a second leaching stage with the roasted ore, which might also act as a preliminary ironmore » removal step, and (iv) effect of tailings washing on the solid waste classification. Different base compounds have been tested, including CaO, CaCO{sub 3}, NaOH, and Na{sub 2}CO{sub 3}. The latter gave the best results concerning both the precipitation process kinetics and the reagent consumption. The filtration of the liquor leach prior to iron removal was not necessary, implying significant savings in capital costs. A reduction of chemical consumption and an increase of manganese concentration in the solution were obtained by introducing secondary leaching tests with the previously roasted ore; this additional step was introduced without a significant decrease of global manganese extraction yield. Finally, toxicity characteristic leaching procedure (TCLP) tests carried out on the leaching solid waste showed: (i) a reduction of arsenic mobility in the presence of iron precipitates, and (ii) the need for a washing step in order to produce a waste that is classifiable as not dangerous, taking into consideration the existing Environmental National Laws.« less

Time delay of critical images of a point source near the gravitational lens fold-caustic

NASA Astrophysics Data System (ADS)

Alexandrov, A.; Zhdanov, V.

2016-06-01

Within the framework of the analytical theory of the gravitational lensing we derive asymptotic formula for the time delay of critical images of apoint source, which is situated near a fold-caustic. We found corrections of the first and second order in powers of a parameter, which describescloseness of the source to the caustic. Our formula modifies earlier result by Congdon, Keeton &Nordgren (MNRAS, 2008) obtained in zero-orderapproximation. We have proved the hypothesis put forward by these authors that the first-order correction to the relative time delay of two criticalmages is identically zero. The contribution of the corrections is illustrated in model example by comparison with exact expression.

A Medical Monitoring Program for the Marine Hazardous Chemical Worker. Volume 1

DTIC Science & Technology

1985-12-01

ri-CR ESOL CRL 0 O-CRESOL CSL 0 P-CRESOL CSO 0 C RE SOL S CRS 0 CRESYLATE SPENT CAUSTIC CSC 0 CROTONALDEH’YDE CTA -0 C UPINE cuml 0 CYCLOHEXANE CHX 0...BLACk BASE 0 CARBON DISULIFIDE CBS 0 CARBON MONOG IDE CARBON TETRACHLORIDE CST 0 CAUSTIC POTASH SOLUTION CPS a CAUSTIC SODA SOLUTION CSS 0 CETYL ALCOHOL...HXN D 1 -𔃾.AENE HXE Ci HEXYLENE *;i -COL HX(G 0 H, TrClCHL0 . ACID 14CL 13 H’vDPC-wLO’.. ACID. SPENT (15%. OP LESS) Hcs C) HYSý90F! tOJCQ AC 10 HFA 0 H

49 CFR 173.469 - Tests for special form Class 7 (radioactive) materials.

Code of Federal Regulations, 2013 CFR

2013-10-01

... be determined by— (i) A method no less sensitive than the leaching assessment prescribed in paragraph... volume greater than 0.1 milliliter, an alternative to the leaching assessment is a demonstration of... contained in a sealed capsule need not be subjected to the leaching assessment specified in paragraph (c) of...

49 CFR 173.469 - Tests for special form Class 7 (radioactive) materials.

Code of Federal Regulations, 2012 CFR

2012-10-01

... be determined by— (i) A method no less sensitive than the leaching assessment prescribed in paragraph... volume greater than 0.1 milliliter, an alternative to the leaching assessment is a demonstration of... contained in a sealed capsule need not be subjected to the leaching assessment specified in paragraph (c) of...

49 CFR 173.469 - Tests for special form Class 7 (radioactive) materials.

Code of Federal Regulations, 2014 CFR

2014-10-01

... be determined by— (i) A method no less sensitive than the leaching assessment prescribed in paragraph... volume greater than 0.1 milliliter, an alternative to the leaching assessment is a demonstration of... contained in a sealed capsule need not be subjected to the leaching assessment specified in paragraph (c) of...

49 CFR 173.469 - Tests for special form Class 7 (radioactive) materials.

Code of Federal Regulations, 2011 CFR

2011-10-01

... be determined by— (i) A method no less sensitive than the leaching assessment prescribed in paragraph... volume greater than 0.1 milliliter, an alternative to the leaching assessment is a demonstration of... contained in a sealed capsule need not be subjected to the leaching assessment specified in paragraph (c) of...

Leaching behaviour of incineration bottom ash in a reuse scenario: 12years-field data vs. lab test results.

PubMed

Di Gianfilippo, Martina; Hyks, Jiri; Verginelli, Iason; Costa, Giulia; Hjelmar, Ole; Lombardi, Francesco

2018-03-01

Several types of standardized laboratory leaching tests have been developed during the past few decades to evaluate the leaching behaviour of waste materials as a function of different parameters, such as the pH of the eluate and the liquid to solid ratio. However, the link between the results of these tests and leaching data collected from the field (e.g. in disposal or reuse scenarios) is not always straightforward. In this work, we compare data obtained from an on-going large scale field trial, in which municipal solid waste incineration bottom ash is being tested as road sub-base material, with the results obtained from percolation column and pH-dependence laboratory leaching tests carried out on the bottom ash at the beginning of the test. The comparisons reported in this paper show that for soluble substances (e.g. Cl, K and SO 4 ), percolation column tests can provide a good indication of the release expected in the field with deviations usually within a factor of 3. For metals characterized by a solubility-controlled release, i.e. that depends more on eluate pH than the liquid to solid ratio applied, the results of pH-dependence tests describe more accurately the eluate concentration trends observed in the field with deviations that in most cases (around 80%) are within one order of magnitude (see e.g. Al and Cd). The differences between field and lab-scale data might be in part ascribed to the occurrence in the field of weathering reactions (e.g. carbonation) but also to microbial decomposition of organic matter that modifying leachate pH affect the solubility of several constituents (e.g. Ca, Ba and Cr). Besides, weathering reactions can result in enhanced adsorption of fulvic acids to iron/aluminum (hydr)oxides, leading to a decrease in the leaching of fulvic acids and hence of elements such as Cu, Ni and Pb that strongly depend on DOC leaching. Overall, this comparison shows that percolation column tests and pH-dependence tests can represent a reliable screening tool to derive data that could be employed in risk-based analysis or life cycle assessment (LCA) frameworks for evaluating potential environmental impacts deriving from specific disposal/reuse options for waste materials. Copyright © 2017 Elsevier Ltd. All rights reserved.

40 CFR 63.1082 - What definitions do I need to know?

Code of Federal Regulations, 2011 CFR

2011-07-01

... includes direct-contact cooling water. Spent caustic waste stream means the continuously flowing process... compounds from process streams, typically cracked gas. The spent caustic waste stream does not include spent..., and the C4 butadiene storage equipment; and spent wash water from the C4 crude butadiene carbonyl wash...

40 CFR 63.1082 - What definitions do I need to know?

Code of Federal Regulations, 2012 CFR

2012-07-01

... includes direct-contact cooling water. Spent caustic waste stream means the continuously flowing process... compounds from process streams, typically cracked gas. The spent caustic waste stream does not include spent..., and the C4 butadiene storage equipment; and spent wash water from the C4 crude butadiene carbonyl wash...

40 CFR 63.1082 - What definitions do I need to know?

Code of Federal Regulations, 2014 CFR

2014-07-01

... includes direct-contact cooling water. Spent caustic waste stream means the continuously flowing process... compounds from process streams, typically cracked gas. The spent caustic waste stream does not include spent..., and the C4 butadiene storage equipment; and spent wash water from the C4 crude butadiene carbonyl wash...

40 CFR 63.1082 - What definitions do I need to know?

Code of Federal Regulations, 2013 CFR

2013-07-01

... includes direct-contact cooling water. Spent caustic waste stream means the continuously flowing process... compounds from process streams, typically cracked gas. The spent caustic waste stream does not include spent..., and the C4 butadiene storage equipment; and spent wash water from the C4 crude butadiene carbonyl wash...

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

21 CFR 184.1763 - Sodium hydroxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium hydroxide. 184.1763 Section 184.1763 Food... Specific Substances Affirmed as GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg. No. 1310-73-2) is also known as sodium hydrate, soda lye, caustic soda, white caustic, and lye. The...

21 CFR 184.1763 - Sodium hydroxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium hydroxide. 184.1763 Section 184.1763 Food... Specific Substances Affirmed as GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg. No. 1310-73-2) is also known as sodium hydrate, soda lye, caustic soda, white caustic, and lye. The...

21 CFR 184.1763 - Sodium hydroxide.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium hydroxide. 184.1763 Section 184.1763 Food... Specific Substances Affirmed as GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg. No. 1310-73-2) is also known as sodium hydrate, soda lye, caustic soda, white caustic, and lye. The...

21 CFR 184.1763 - Sodium hydroxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium hydroxide. 184.1763 Section 184.1763 Food... Specific Substances Affirmed as GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg. No. 1310-73-2) is also known as sodium hydrate, soda lye, caustic soda, white caustic, and lye. The...

Letter from Galo Jackson, USEPA to Prashant Gupta, Honeywell, Inc. Subject: Caustic Brine Offsite Shipments: LCP Chemical National Priorities List Site, Brunswick, Glynn County, GA

EPA Pesticide Factsheets

Feb. 17, 2012 letter about suspending all shipments of caustic brine from the LCP Chemicals site to the Water Recovery, Inc. facility in Jacksonville, FL. Region ID: 04 DocID: 10843423, DocDate: 02-17-2012

Background information for the Leaching environmental Assessment Framework (LEAF) test methods

EPA Science Inventory

The U.S. Environmental Protection Agency Office of Resource Conservation and Recovery has initiated the review and validation process for four leaching tests under consideration for inclusion into SW-846: Method 1313 "Liquid-Solid Partitioning as a Function of Extract pH for Co...

Leaching behavior of microtektite glass compositions in sea water and the effect of precipitation on glass leaching

NASA Technical Reports Server (NTRS)

1991-01-01

The present study attempts to account for the slow corrosion rates of microtektite glass in nature by comparing the leach rates of synthetic microtektite glass samples in deionized water and in sea-water, respectively. In order to obtain systematic data about leachant composition effects, leach tests were also carried out with synthetic leachant compositions enriched with respect to silica or depleted with respect to certain major components of sea-water (Mg, Ca).

Decay resistance of wood treated with boric acid and tall oil derivates.

PubMed

Temiz, Ali; Alfredsen, Gry; Eikenes, Morten; Terziev, Nasko

2008-05-01

In this study, the effect of two boric acid concentrations (1% and 2%) and four derivates of tall oil with varying chemical composition were tested separately and in combination. The tall oil derivates were chosen in a way that they consist of different amounts of free fatty, resin acids and neutral compounds. Decay tests using two brown rot fungi (Postia placenta and Coniophora puteana) were performed on both unleached and leached test samples. Boric acid showed a low weight loss in test samples when exposed to fungal decay before leaching, but no effect after leaching. The tall oil derivates gave better efficacy against decay fungi compared to control, but are not within the range of the efficacy needed for a wood preservative. Double impregnation with boric acid and tall oil derivates gave synergistic effects for several of the double treatments both in unleached and leached samples. In the unleached samples the double treatment gave a better efficacy against decay fungi than tall oil alone. In leached samples a better efficacy against brown rot fungi were achieved than in samples with boron alone and a nearly similar or better efficacy than for tall oil alone. Boric acid at 2% concentration combined with the tall oil derivate consisting of 90% free resin acids (TO-III) showed the best performance against the two decay fungi with a weight loss less than 3% after a modified pure culture test.

Risk factors associated with refractoriness to esophageal dilatation for benign dysphagia.

PubMed

Rodrigues-Pinto, Eduardo; Pereira, Pedro; Ribeiro, Armando; Lopes, Susana; Moutinho-Ribeiro, Pedro; Silva, Marco; Peixoto, Armando; Gaspar, Rui; Macedo, Guilherme

2016-06-01

Benign esophageal strictures need repeated dilatations to relieve dysphagia. Literature is scarce on the risk factors for refractoriness of these strictures. This study aimed to assess the risk factors associated with refractory strictures. This is a retrospective study of patients with benign esophageal strictures who were referred for esophageal dilatation over a period of 3 years. A total of 327 esophageal dilatations were performed in 103 patients; 53% of the patients reported dysphagia for liquids. Clinical success was achieved in 77% of the patients. There was a need for further dilatations in 54% of patients, being more frequent in patients with dysphagia for liquids [78 vs. 64%, P=0.008, odds ratio (OR) 1.930], in those with caustic strictures (89 vs. 70%, P=0.007, OR 3.487), and in those with complex strictures (83 vs. 70%, P=0.047, OR 2.132). Caustic strictures, peptic strictures, and complex strictures showed statistical significance in the multivariate analysis. Time until subsequent dilatations was less in patients with dysphagia for liquids (49 vs. 182 days, P<0.001), in those with peptic strictures (49 vs. 98 days, P=0.004), in those with caustic strictures (49 vs. 78 days, P=0.005), and in patients with complex strictures (47 vs. 80 days P=0.009). In multivariate analysis, further dilatations occurred earlier in patients with dysphagia for liquids [hazard ratio (HR) 1.506, P=0.004], in those with peptic strictures (HR 1.644, P=0.002), in those with caustic strictures (HR 1.581, P=0.016), and in patients with complex strictures (HR 1.408, P=0.046). Caustic, peptic, and complex strictures were associated with a greater need for subsequent dilatations. Time until subsequent dilatations was less in patients with dysphagia for liquids and in those with caustic, peptic, and complex strictures.

A geochemical module for "AMDTreat" to compute caustic quantity, effluent quantity, and sludge volume

USGS Publications Warehouse

Cravotta, Charles A.; Parkhurst, David L.; Means, Brent P; McKenzie, Bob; Morris, Harry; Arthur, Bill

2010-01-01

Treatment with caustic chemicals typically is used to increase pH and decrease concentrations of dissolved aluminum, iron, and/or manganese in largevolume, metal-laden discharges from active coal mines. Generally, aluminum and iron can be removed effectively at near-neutral pH (6 to 8), whereas active manganese removal requires treatment to alkaline pH (~10). The treatment cost depends on the specific chemical used (NaOH, CaO, Ca(OH)2, Na2CO3, or NH3) and increases with the quantities of chemical added and sludge produced. The pH and metals concentrations do not change linearly with the amount of chemical added. Consequently, the amount of caustic chemical needed to achieve a target pH and the corresponding effluent composition and sludge volume can not be accurately determined without empirical titration data or the application of geochemical models to simulate the titration of the discharge water with caustic chemical(s). The AMDTreat computer program (http://amd.osmre.gov/ ) is widely used to compute costs for treatment of coal-mine drainage. Although AMDTreat can use results of empirical titration with industrial grade caustic chemicals to compute chemical costs for treatment of net-acidic or net-alkaline mine drainage, such data are rarely available. To improve the capability of AMDTreat to estimate (1) the quantity and cost of caustic chemicals to attain a target pH, (2) the concentrations of dissolved metals in treated effluent, and (3) the volume of sludge produced by the treatment, a titration simulation is being developed using the geochemical program PHREEQC (wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc/) that will be coupled as a module to AMDTreat. The simulated titration results can be compared with or used in place of empirical titration data to estimate chemical quantities and costs. This paper describes the development, evaluation, and potential utilization of the PHREEQC titration module for AMDTreat.

STATISTICS OF MICROLENSING CAUSTIC CROSSINGS IN Q 2237+0305: PECULIAR VELOCITY OF THE LENS GALAXY AND ACCRETION DISK SIZE

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

Mediavilla, E.; Jimenez-Vicente, J.; Muñoz, J. A.

We use the statistics of caustic crossings induced by microlensing in the lens system Q 2237+0305 to study the lens galaxy peculiar velocity. We calculate the caustic crossing rates for a comprehensive family of stellar mass functions and find a dependence of the average number of caustic crossings with the effective transverse velocity and the average mass, 〈n〉∝v{sub eff}/√(〈m〉), equivalent to the theoretical prediction for the case of microlenses with identical masses. We explore the possibilities of the method to measure v {sub eff} using the ∼12 yr of Optical Gravitational Lensing Experiment monitoring of the four images of Qmore » 2237+0305. To determine a lower limit for v {sub eff}, we count, conservatively, a single caustic crossing for each one of the four high magnification events identified in the literature (plus one additional proposed by us) obtaining v{sub eff}≳240√(〈m〉/0.17 M{sub ⊙}) km s{sup −1} at 68% of confidence. From this value and the average FWHM of the four high magnification events, we obtain a lower limit of r{sub s}≳1.4√(〈m〉/0.17 M{sub ⊙}) light-days for the radius of the source (r{sub s} = FWHM/2.35). Tentative identification of three additional caustic crossing events leads to estimates of v{sub eff}≃(493±246)√(〈m〉/0.17 M{sub ⊙}) km s{sup −1} for the effective transverse velocity and of r{sub s}≃(2.7±1.3)√(〈m〉/0.17 M{sub ⊙}) light-days for the source size. The estimated transverse peculiar velocity of the galaxy is v{sub t}≃(429±246)√(〈m〉/0.17 M{sub ⊙}) km s{sup −1}.« less

Backscattering of sound from targets in an Airy caustic formed by a curved reflecting surface

NASA Astrophysics Data System (ADS)

Dzikowicz, Benjamin Robert

The focusing of a caustic associated with the reflection of a locally curved sea floor or surface affects the scattering of sound by underwater targets. The most elementary caustic formed when sound reflects off a naturally curved surface is an Airy caustic. The case of a spherical target is examined here. With a point source acting also as a receiver, a point target lying in a shadow region returns only one echo directly from the target. When the target is on the Airy caustic, there are two echoes: one path is directly to the target and the other focuses off the curved surface. Echoes may be focused in both directions, the doubly focused case being the largest and the latest echo. With the target in the lit region, these different paths produce multiple echoes. For a finite sized sphere near an Airy caustic, all these echoes are manifest, but they occur at shifted target positions. Echoes of tone bursts reflecting only once overlap and interfere with each other, as do those reflecting twice. Catastrophe theory is used to analyze the echo amplitudes arising from these overlaps. The echo pressure for single reflections is shown to have a dependence on target position described by an Airy function for both a point and a finite target. With double focusing, this dependence is the square of an Airy function for a point target. With a finite sized target, (as in the experiment) this becomes a hyperbolic umbilic catastrophe integral with symmetric arguments. The arguments of each of these functions are derived from only the relative echo times of a transient pulse. Transient echo times are calculated using a numerical ray finding technique. Experiment confirms the predicted merging of transient echoes in the time domain, as well as the Airy and hyperbolic umbilic diffraction integral amplitudes for a tone burst. This method allows targets to be observed at greater distances in the presence of a focusing surface.

Presence and leaching of bisphenol a (BPA) from dental materials

PubMed Central

Becher, Rune; Wellendorf, Hanne; Sakhi, Amrit Kaur; Samuelsen, Jan Tore; Thomsen, Cathrine; Bølling, Anette Kocbach; Kopperud, Hilde Molvig

2018-01-01

Abstract BPA has been reported to leach from some resin based dental restorative materials and materials used for orthodontic treatment. To confirm and update previous findings, especially in light of the new temporary lower threshold value for tolerable daily BPA intake, we have investigated the leaching of BPA from 4 composite filling materials, 3 sealants and 2 orthodontic bonding materials. The materials were either uncured and dissolved in methanol or cured. The cured materials were kept in deionized water for 24 hours or 2 weeks. Samples were subsequently analyzed by ultra-performance liquid chromatography coupled to mass spectrometry (UPLC-MS-MS). The composite filling material Tetric EvoFlow® and the fissure sealant DELTON® showed significantly higher levels of BPA leaching compared to control samples for all test conditions (uncured, 24 h leaching and 2 weeks leaching). There were no significant differences in amount of leached BPA for any of the tested materials after 24 hours compared to 2 weeks. These results show that BPA is still released from some dental materials despite the general concern about potential adverse effects of BPA. However, the amounts of BPA were relatively low and most likely represent a very small contribution to the total BPA exposure. PMID:29868625

A uniform geometrical optics and an extended uniform geometrical theory of diffraction for evaluating high frequency EM fields near smooth caustics and composite shadow boundaries

NASA Technical Reports Server (NTRS)

Constantinides, E. D.; Marhefka, R. J.

1994-01-01

A uniform geometrical optics (UGO) and an extended uniform geometrical theory of diffraction (EUTD) are developed for evaluating high frequency electromagnetic (EM) fields within transition regions associated with a two and three dimensional smooth caustic of reflected rays and a composite shadow boundary formed by the caustic termination or the confluence of the caustic with the reflection shadow boundary (RSB). The UGO is a uniform version of the classic geometrical optics (GO). It retains the simple ray optical expressions of classic GO and employs a new set of uniform reflection coefficients. The UGO also includes a uniform version of the complex GO ray field that exists on the dark side of the smooth caustic. The EUTD is an extension of the classic uniform geometrical theory of diffraction (UTD) and accounts for the non-ray optical behavior of the UGO reflected field near caustics by using a two-variable transition function in the expressions for the edge diffraction coefficients. It also uniformly recovers the classic UTD behavior of the edge diffracted field outside the composite shadow boundary transition region. The approach employed for constructing the UGO/EUTD solution is based on a spatial domain physical optics (PO) radiation integral representation for the fields which is then reduced using uniform asymptotic procedures. The UGO/EUTD analysis is also employed to investigate the far-zone RCS problem of plane wave scattering from two and three dimensional polynomial defined surfaces, and uniform reflection, zero-curvature, and edge diffraction coefficients are derived. Numerical results for the scattering and diffraction from cubic and fourth order polynomial strips are also shown and the UGO/EUTD solution is validated by comparison to an independent moment method (MM) solution. The UGO/EUTD solution is also compared with the classic GO/UTD solution. The failure of the classic techniques near caustics and composite shadow boundaries is clearly demonstrated and it is shown that the UGO/EUTD results remain valid and uniformly reduce to the classic results away from the transition regions. Mathematical details on the asymptotic properties and efficient numerical evaluation of the canonical functions involved in the UGO/EUTD expressions are also provided.

Multiple heavy metals extraction and recovery from hazardous electroplating sludge waste via ultrasonically enhanced two-stage acid leaching.

PubMed

Li, Chuncheng; Xie, Fengchun; Ma, Yang; Cai, Tingting; Li, Haiying; Huang, Zhiyuan; Yuan, Gaoqing

2010-06-15

An ultrasonically enhanced two-stage acid leaching process on extracting and recovering multiple heavy metals from actual electroplating sludge was studied in lab tests. It provided an effective technique for separation of valuable metals (Cu, Ni and Zn) from less valuable metals (Fe and Cr) in electroplating sludge. The efficiency of the process had been measured with the leaching efficiencies and recovery rates of the metals. Enhanced by ultrasonic power, the first-stage acid leaching demonstrated leaching rates of 96.72%, 97.77%, 98.00%, 53.03%, and 0.44% for Cu, Ni, Zn, Cr, and Fe respectively, effectively separated half of Cr and almost all of Fe from mixed metals. The subsequent second-stage leaching achieved leaching rates of 75.03%, 81.05%, 81.39%, 1.02%, and 0% for Cu, Ni, Zn, Cr, and Fe that further separated Cu, Ni, and Zn from mixed metals. With the stabilized two-stage ultrasonically enhanced leaching, the resulting over all recovery rates of Cu, Ni, Zn, Cr and Fe from electroplating sludge could be achieved at 97.42%, 98.46%, 98.63%, 98.32% and 100% respectively, with Cr and Fe in solids and the rest of the metals in an aqueous solution discharged from the leaching system. The process performance parameters studied were pH, ultrasonic power, and contact time. The results were also confirmed in an industrial pilot-scale test, and same high metal recoveries were performed. Copyright 2010 Elsevier B.V. All rights reserved.

Total gastrectomy due to ferric chloride intoxication.

PubMed

Menéndez, A Mesut; Abramson, Leonardo; Vera, Raúl A; Duza, Guillermo E; Palermo, Mariano

2015-09-01

The ferric chloride intoxication is frequently caused by accident. Its toxicity is generally underrated, which can lead to fatal evolution or irreversible consequences. In this case, the caustic condition of the substance is related to the toxic properties of iron. A 36-year-old male patient arrives by ambulance indicating sensory deterioration. He presents erosive injuries in the buccal cavity and in the oropharynx, brownish teeth and metabolic acidosis. Toxicology tests and ferritin blood dosage are requested, which show a result from 1400 mg/dl. The symptoms are interpreted as acute iron intoxication. Due to the unfavorable evolution of his condition, an abdominal and pelvic CT scan are performed, which show extensive pneumoperitoneum and free fluid in the abdominal cavity. An exploratory laparotomy, a total gastrectomy with esophagostomy and feeding jejunostomy, washing and drainage due to perforated gastric necrosis caused by caustic ingestion are performed. In our country, there is a high rate of intoxication caused by iron compounds, although it is not statistically measured. Nevertheless, the ferric chloride intoxication is extremely infrequent. The ingestion of this product leads to complications, which are associated with the iron concentration and its condition as a caustic agent. The surgical indications in the presence of intoxication caused by iron compounds are: stomach evacuation of iron, gastric necrosis, perforation or peritonitis and stenosis. Early or prophylactic gastrectomy is contraindicated. However, if complications that require immediate surgical intervention arise, there should be no hesitation and the corresponding procedure should be performed.

Leaching characteristics of toxic constituents from coal fly ash mixed soils under the influence of pH

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

Komonweeraket, Kanokwan; Cetin, Bora, E-mail: bora.cetin@sdsmt.edu; Benson, Craig H., E-mail: chbenson@wisc.edu

Highlights: • The impact of pH on the leaching of elements and metals from fly ash mixed soils. • Generally Ca, Cd, Mg, and Sr follows a cationic leaching pattern. • The leaching of As and Se shows an oxyanionic leaching pattern. • The leaching behavior of elements does not change based on material type. • Different fly ash types show different abilities in immobilizing trace elements. - Abstract: Leaching behaviors of Arsenic (As), Barium (Ba), Calcium (Ca), Cadmium (Cd), Magnesium (Mg), Selenium (Se), and Strontium (Sr) from soil alone, coal fly ash alone, and soil-coal fly ash mixtures, weremore » studied at a pH range of 2–14 via pH-dependent leaching tests. Seven different types of soils and coal fly ashes were tested. Results of this study indicated that Ca, Cd, Mg, and Sr showed cationic leaching pattern while As and Se generally follows an oxyanionic leaching pattern. On the other hand, leaching of Ba presented amphoteric-like leaching pattern but less pH-dependent. In spite of different types and composition of soil and coal fly ash investigated, the study reveals the similarity in leaching behavior as a function of pH for a given element from soil, coal fly ash, and soil-coal fly ash mixtures. The similarity is most likely due to similar controlling mechanisms (e.g., solubility, sorption, and solid-solution formation) and similar controlling factors (e.g., leachate pH and redox conditions). This offers the opportunity to transfer knowledge of coal fly ash that has been extensively characterized and studied to soil stabilized with coal fly ash. It is speculated that unburned carbon in off-specification coal fly ashes may provide sorption sites for Cd resulting in a reduction in concentration of these elements in leachate from soil-coal fly ash mixture. Class C fly ash provides sufficient CaO to initiate the pozzolanic reaction yielding hydrated cement products that oxyanions, including As and Se, can be incorporated into.« less

Sustainable materials management using the Leaching Environmental Assessment Framework test methods

EPA Science Inventory

The need for improved leach tests became a priority due to adoption of more stringent air pollution control at U.S. coal-fired power plants resulting in the preferential partitioning of mercury (Hg) and other pollutants to fly ash and other air pollution control residues. Fly ash...

Durability test on irradiated rock-like oxide fuels

NASA Astrophysics Data System (ADS)

Kuramoto, K.; Nitani, N.; Yamashita, T.

2003-06-01

For a profitable use of Pu, Japan Atomic Energy Research Institute has been promoting researches for once-through type fuels. The strategy consists of stable rock-like oxide fuel fabrication in conventional fuel facilities followed by almost complete Pu burning in LWR and disposal of chemically stable spent fuel without further processing. Because leach rates of hazardous nuclides, such as TRU and β-emitters, that have long half-lives, are very important for the evaluation of geological safety, leaching tests in deionized water at 363 K were performed with reference to the MCC-1 method. Five irradiated fuel pellets, a single phase fuel of a yttria-stabilized zirconia (YSZ) containing UO 2 (U-YSZ), two fuels of U-YSZ particle dispersed in MgAl 2O 4 (SPI) or Al 2O 3 (COR) matrix, two homogeneous-blended fuels of U-YSZ and SPI or COR powders, were submitted to the tests. Stainless steel containers with Au coating and ethylene propylene diene monomer were used as leaching vessels and packing, respectively. The evaluated normalized leach rates of Zr, U and Pu were obviously lower than those of the other important elements and nuclides. Americium, Np and especially Y showed unexpectedly high evaluated normalized leach rates. The volatile elements, Cs and I, showed enhanced leaching within particle-dispersed type fuels because of crack formation around the particle.

Assessment of Pb, Cd, Cr and Ag leaching from electronics waste using four extraction methods.

PubMed

Keith, Ashley; Keesling, Kara; Fitzwater, Kendra K; Pichtel, John; Houy, Denise

2008-12-01

Heavy metals present in electronic components may leach upon disposal and therefore pose significant environmental hazards. The potential leaching of Pb, Cd, Cr and Ag from PC cathode ray tubes, printed circuit boards (PCBs), PC mice, TV remote controls, and mobile phones was assessed. After controlled crushing, each component was extracted using the Toxicity Characteristic Leaching Procedure (TCLP), EPA Method 1312 (SPLP), NEN 7371 (Dutch Environmental Agency), and DIN S4 (Germany). The TCLP consistently leached the greatest amounts of Pb from all components. The SPLP, NEN 7371 and DIN S4 extracted relatively small amounts of metals compared with the TCLP and were not considered effective as leaching tests for e-waste. The smallest size fraction (< 2 mm) of CRT glass and PCBs leached significantly (p < 0.05) highest Pb via the TCLP. A modified TCLP removed 50.9% more extractable Pb compared with the conventional procedure.

4. Photocopy of photograph, U.S. Army, ca. 1943 (original print ...

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

4. Photocopy of photograph, U.S. Army, ca. 1943 (original print located at Rocky Mountain Arsenal, Commerce City, Colorado). R.M.A. - 254 - CAUSTIC FUSION BLDG. LOOKING WEST. NORTH SIDE. - Rocky Mountain Arsenal, Caustic Fusion Building, 450 feet South of December Seventh Avenue; 900 feet West of D Street, Commerce City, Adams County, CO

3. Photocopy of photograph, U.S. Army, ca. 1943 (original print ...

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

3. Photocopy of photograph, U.S. Army, ca. 1943 (original print located at Rocky Mountain Arsenal, Commerce City, Colorado). R.M.A. - 254 - CAUSTIC FUSION BLDG. LOOKING N.W. - Rocky Mountain Arsenal, Caustic Fusion Building, 450 feet South of December Seventh Avenue; 900 feet West of D Street, Commerce City, Adams County, CO

21 CFR 184.1763 - Sodium hydroxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium hydroxide. 184.1763 Section 184.1763 Food... GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg. No. 1310-73-2) is also known as sodium hydrate, soda lye, caustic soda, white caustic, and lye. The empirical formula is NaOH. Sodium...

Regional assessment of NLEAP NO3-N leaching indices

USGS Publications Warehouse

Wylie, B.K.; Shaffer, M.J.; Hall, M.D.

1995-01-01

Nonpoint source ground water contamination by nitrate nitrogen (NO3-N) leached from agricultural lands can be substantial and increase health risks to humans and animals. Accurate and rapid methods are needed to identify and map localities that have a high potential for contamination of shallow aquifers with NO3-N leached from agriculture. Evaluation of Nitrate Leaching and Economic Analysis Package (NLEAP) indices and input variables across an irrigated agricultural area on an alluvial aquifer in Colorado indicated that all leaching indices tested were more strongly correlated with aquifer NO3-N concentration than with aquifer N mass. Of the indices and variables tested, the NO3-N Leached (NL) index was the NLEAP index most strongly associated with groundwater NO3-N concentration (r2 values from 0.37 to 0.39). NO3-N concentration of the leachate was less well correlated with ground water NO3-N concentration (r2values from 0.21 to 0.22). Stepwise regression analysis indicated that, although inorganic and organic/inorganic fertilizer scenarios had similar r2 values, the Feedlot Indicator (proximity) variable was significant over and above the NO3-N Leached index for the inorganic scenario. The analysis also showed that combination of either Movement Risk Index (MIRI) or NO3-N concentration of the leachate with the NO3-N Leached index leads to an improved regression, which provides insight into area-wide associations between agricultural activities and ground water NO3-N concentration.

Effect of acid rain pH on leaching behavior of cement stabilized lead-contaminated soil.

PubMed

Du, Yan-Jun; Wei, Ming-Li; Reddy, Krishna R; Liu, Zhao-Peng; Jin, Fei

2014-04-30

Cement stabilization is a practical approach to remediate soils contaminated with high levels of lead. However, the potential for leaching of lead out of these stabilized soils under variable acid rain pH conditions is a major environmental concern. This study investigates the effects of acid rain on the leaching characteristics of cement stabilized lead contaminated soil under different pH conditions. Clean kaolin clay and the same soil spiked with 2% lead contamination are stabilized with cement contents of 12 and 18% and then cured for 28 days. The soil samples are then subjected to a series of accelerated leaching tests (or semi-dynamic leaching tests) using a simulated acid rain leachant prepared at pH 2.0, 4.0 or 7.0. The results show that the strongly acidic leachant (pH ∼2.0) significantly altered the leaching behavior of lead as well as calcium present in the soil. However, the differences in the leaching behavior of the soil when the leachant was mildly acidic (pH ∼4.0) and neutral (pH ∼7.0) prove to be minor. In addition, it is observed that the lead contamination and cement content levels can have a considerable impact on the leaching behavior of the soils. Overall, the leachability of lead and calcium is attributed to the stability of the hydration products and their consequent influence on the soil buffering capacity and structure. Copyright © 2014 Elsevier B.V. All rights reserved.

Immobilization of copper flotation waste using red mud and clinoptilolite.

PubMed

Coruh, Semra

2008-10-01

The flash smelting process has been used in the copper industry for a number of years and has replaced most of the reverberatory applications, known as conventional copper smelting processes. Copper smelters produce large amounts of copper slag or copper flotation waste and the dumping of these quantities of copper slag causes economic, environmental and space problems. The aim of this study was to perform a laboratory investigation to assess the feasibility of immobilizing the heavy metals contained in copper flotation waste. For this purpose, samples of copper flotation waste were immobilized with relatively small proportions of red mud and large proportions of clinoptilolite. The results of laboratory leaching demonstrate that addition of red mud and clinoptilolite to the copper flotation waste drastically reduced the heavy metal content in the effluent and the red mud performed better than clinoptilolite. This study also compared the leaching behaviour of metals in copper flotation waste by short-time extraction tests such as the toxicity characteristic leaching procedure (TCLP), deionized water (DI) and field leach test (FLT). The results of leach tests showed that the results of the FLT and DI methods were close and generally lower than those of the TCLP methods.

Scoping Candidate Minerals for Stabilization of Arsenic-Bearing Solid Residuals

PubMed Central

Raghav, Madhumitha; Shan, Jilei; Sáez, A. Eduardo; Ela, Wendell P.

2014-01-01

Arsenic Crystallization Technology (ACT) is a potentially eco-friendly, effective technology for stabilization of arsenic-bearing solid residuals (ABSRs). The strategy is to convert ABSRs generated by water treatment facilities into minerals with a high arsenic capacity and long-term stability in mature, municipal solid waste landfills. Candidate minerals considered in this study include scorodite, arsenate hydroxyapatites, ferrous arsenates (symplesite-type minerals), tooeleite, and arsenated-schwertmannite. These minerals were evaluated as to ease of synthesis, applicability to use of iron-based ABSRs as a starting material, and arsenic leachability. The Toxicity Characteristic Leaching Procedure (TCLP) was used for preliminary assessment of candidate mineral leaching. Minerals that passed the TCLP and whose synthesis route was promising were subjected to a more aggressive leaching test using a simulated landfill leachate (SLL) solution. Scorodite and arsenate hydroxyapatites were not considered further because their synthesis conditions were not found to be favorable for general application. Tooeleite and silica-amended tooeleite showed high TCLP arsenic leaching and were also not investigated further. The synthesis process and leaching of ferrous arsenate and arsenated-schwertmannite were promising and of these, arsenated-schwertmannite was most stable during SLL testing. The latter two candidate minerals warrant synthesis optimization and more extensive testing. PMID:24231323

Treatment of waste printed wire boards in electronic waste for safe disposal.

PubMed

Niu, Xiaojun; Li, Yadong

2007-07-16

The printed wire boards (PWBs) in electronic waste (E-waste) have been found to contain large amounts of toxic substances. Studies have concluded that the waste PWBs are hazardous wastes because they fails the toxicity characteristic leaching procedure (TCLP) test with high level of lead (Pb) leaching out. In this study, two treatment methods - high-pressure compaction and cement solidification - were explored for rendering the PWBs into non-hazardous forms so that they may be safely disposed or used. The high-pressure compaction method could turn the PWBs into high-density compacts with significant volume reduction, but the impact resistance of the compacts was too low to keep them intact in the environment for a long run. In contrast, the cement solidification could turn the PWBs into strong monoliths with high impact resistance and relatively high compressive strength. The leaching of the toxic heavy metal Pb from the solidified samples was evaluated by both a dynamic leaching test and the TCLP test. The dynamic leaching results revealed that Pb could be effectively confined in the solidified products under very harsh environmental conditions. The TCLP test results showed that the leaching level of Pb was far below the regulatory level of 5mg/L, suggesting that the solidified PWBs are no longer hazardous. It was concluded that the cement solidification is an effective way to render the waste PWBs into environmentally benign forms so that they can be disposed of as ordinary solid wastes or beneficially used in the place of concrete in some applications.

Toxic metal immobilization in contaminated sediment using bentonite- and kaolinite-supported nano zero-valent iron

NASA Astrophysics Data System (ADS)

Tomašević, D. D.; Kozma, G.; Kerkez, Dj. V.; Dalmacija, B. D.; Dalmacija, M. B.; Bečelić-Tomin, M. R.; Kukovecz, Á.; Kónya, Z.; Rončević, S.

2014-08-01

The objective of this study was to investigate the possibility of using supported nanoscale zero-valent iron with bentonite and kaolinite for immobilization of As, Pb and Zn in contaminated sediment from the Nadela river basin (Serbia). Assessment of the sediment quality based on the pseudo-total metal content (As, Pb and Zn) according to the corresponding Serbian standards shows its severe contamination, such that it requires disposal in special reservoirs and, if possible, remediation. A microwave-assisted sequential extraction procedure was employed to assess potential metal mobility and risk to the aquatic environment. According to these results, As showed lower risk to the environment than Pb and Zn, which both represent higher risk to the environment. The contaminated sediment, irrespective of the different speciation of the treated metals, was subjected to the same treatment. Semi-dynamic leaching test, based on leachability index and effective diffusion coefficients, was conducted for As-, Pb- and Zn-contaminated sediments in order to assess the long-term leaching behaviour. In order to simulate "worst case" leaching conditions, the test was modified using acetic and humic acid solution as leachants instead of deionized water. A diffusion-based model was used to elucidate the controlling leaching mechanisms; in the majority of samples, the controlling leaching mechanism appeared to be diffusion. Three different single-step leaching tests were applied to evaluate the extraction potential of examined metals. Generally, the test results indicated that the treated sediment is safe for disposal and could even be considered for "controlled utilization".

Refining of Military Jet Fuels from Shale Oil. Volume I. Part II. Preparation of Laboratory-Scale Fuel Samples.

DTIC Science & Technology

1982-03-01

ON SPEC Meeting Specifications *1 OXY Test Series on In Situ Shale Oil P Pressure (P + N) Paraffins and Naphthenes PHO Test Series on Above-Ground...material, the crude shale is heated and processed through caustic desalt- ing similar to conventional technology. The desalted oil is mixed with recycle...with hot regenerated catalyst. Spent catalyst and oil vapors are disengaqed by -.eans of high temperature cyclones. The spent catalyst first passes

LEAD LEACHING FROM IN-LINE BRASS DEVICES: A CRITICAL EVALUATION OF THE EXISTING STANDARD

EPA Science Inventory

The ANSI/NSF 61, Section 8 standard is intended to protect the public from in-line brass plumbing products that might leach excessive levels of lead to potable water. Experiments were conducted to examine the practical rigor of this test. Contrary to expectations, the test was no...

Long-term high-level waste technology. Composite report

NASA Astrophysics Data System (ADS)

Cornman, W. R.

1981-12-01

Research and development studies on the immobilization of high-level wastes from the chemical reprocessing of nuclear reactor fuels are summarized. The reports are grouped under the following tasks: (1) program management and support; (2) waste preparation; (3) waste fixation; and (4) final handling. Some of the highlights are: leaching properties were obtained for titanate and tailored ceramic materials being developed at ICPP to immobilize zirconia calcine; comparative leach tests, hot-cell tests, and process evaluations were conducted of waste form alternatives to borosilicate glass for the immobilization of SRP high-level wastes, experiments were run at ANL to qualify neutron activation analysis and radioactive tracers for measuring leach rates from simulated waste glasses; comparative leach test samples of SYNROC D were prepared, characterized, and tested at LLNL; encapsulation of glass marbles with lead or lead alloys was demonstrated on an engineering scale at PNL; a canister for reference Commercial HLW was designed at PNL; a study of the optimization of salt-crete was completed at SRL; a risk assessment showed that an investment for tornado dampers in the interim storage building of the DWPF is unjustified.

Leaching of biocides used in façade coatings under laboratory test conditions.

PubMed

Schoknecht, Ute; Gruycheva, Jana; Mathies, Helena; Bergmann, Hannelore; Burkhardt, Michael

2009-12-15

The European Biocidal Products Directive 98/8/EC requires a risk assessment concerning possible effects of active ingredients on the environment. Biocides can be leached from treated materials exposed to outdoor use. These emissions have to be estimated and evaluated during the authorization procedure. Different immersion and irrigation tests were performed to investigate leaching of biocides from façade coatings. Several marketed formulations of textured coatings and paints spiked with a mixture of commonly used active ingredients (OIT, DCOIT, IPBC, carbendazim, isoproturon, diuron, terbutryn, and Irgarol 1051) were investigated. The emission process can be described by time-dependent functions that depend on the test conditions. The results of all test procedures confirm that leachability is related to water solubility and n-octanol-water partition coefficient of the active ingredients and that leaching of biocides from façade coatings is mainly a diffusion controlled process. Other factors like the composition of the product, availability and transport of water, concentration of active ingredients in the coatings, as well as UV-exposure of the coatings influence biocide emissions.

Interpretation of leaching data for cementitious waste forms using analytical solutions based on mass transport theory and empiricism

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

Spence, R.D.; Godbee, H.W.; Tallent, O.K.

1989-01-01

The analysis of leaching data using analytical solutions based on mass transport theory and empiricism is presented. The waste forms leached to generate the data used in this analysis were prepared with a simulated radioactive waste slurry with traces of potassium ion, manganese ions, carbonate ions, phosphate ions, and sulfate ions solidified with several blends of cementitious materials. Diffusion coefficients were estimated from the results of ANS - 16.1 tests. Data of fraction leached versus time is presented and discussed.

Frequency of use controls chemical leaching from drinking-water containers subject to disinfection.

PubMed

Andra, Syam S; Makris, Konstantinos C; Shine, James P

2011-12-15

Microbial-, and chemical-based burden of disease associated with lack of access to safe water continues to primarily impact developing countries. Cost-effective health risk-mitigating measures, such as of solar disinfection applied to microbial-contaminated water stored in plastic bottles have been increasingly tested in developing countries adversely impacted by epidemic water-borne diseases. Public health concerns associated with chemical leaching from water packaging materials led us to investigate the magnitude and variability of antimony (Sb) and bromine (Br) leaching from reused plastic containers (polyethylene terephthalate, PET; and polycarbonate, PC) subject to UV and/or temperature-driven disinfection. The overall objective of this study was to determine the main and interactive effects of temperature, UV exposure duration, and frequency of bottle reuse on the extent of leaching of Sb and Br from plastic bottles into water. Regardless of UV exposure duration, frequency of reuse (up to 27 times) was the major factor that linearly increased Sb leaching from PET bottles at all temperatures tested (13-47 °C). Leached Sb concentrations (∼360 ng L(-1)) from the highly reused (27 times) PET bottles (minimal Sb leaching from PC bottles, <15 ng L(-1)) did not pose a serious risk to human health according to current daily Sb acceptable intake estimates. Leached Br concentrations from both PET and PC containers (up to ∼15 μg L(-1)) did not pose a consumer health risk either, however, no acceptable daily dose estimates exist for oral ingestion of organo-brominated, or other plasticizers/additives compounds if they were to be found in bottled water at much lower concentrations. Additional research on potential leaching of organic chemicals from water packaging materials is deemed necessary under relevant environmental conditions. Copyright © 2011 Elsevier Ltd. All rights reserved.

On the Observability of Individual Population III Stars and Their Stellar-mass Black Hole Accretion Disks through Cluster Caustic Transits

NASA Astrophysics Data System (ADS)

Windhorst, Rogier A.; Timmes, F. X.; Wyithe, J. Stuart B.; Alpaslan, Mehmet; Andrews, Stephen K.; Coe, Daniel; Diego, Jose M.; Dijkstra, Mark; Driver, Simon P.; Kelly, Patrick L.; Kim, Duho

2018-02-01

We summarize panchromatic Extragalactic Background Light data to place upper limits on the integrated near-infrared surface brightness (SB) that may come from Population III stars and possible accretion disks around their stellar-mass black holes (BHs) in the epoch of First Light, broadly taken from z ≃ 7–17. Theoretical predictions and recent near-infrared power spectra provide tighter constraints on their sky signal. We outline the physical properties of zero-metallicity Population III stars from MESA stellar evolution models through helium depletion and of BH accretion disks at z≳ 7. We assume that second-generation non-zero-metallicity stars can form at higher multiplicity, so that BH accretion disks may be fed by Roche-lobe overflow from lower-mass companions. We use these near-infrared SB constraints to calculate the number of caustic transits behind lensing clusters that the James Webb Space Telescope and the next-generation ground-based telescopes may observe for both Population III stars and their BH accretion disks. Typical caustic magnifications can be μ ≃ {10}4{--}{10}5, with rise times of hours and decline times of ≲ 1 year for cluster transverse velocities of {v}T≲ 1000 km s‑1. Microlensing by intracluster-medium objects can modify transit magnifications but lengthen visibility times. Depending on BH masses, accretion-disk radii, and feeding efficiencies, stellar-mass BH accretion-disk caustic transits could outnumber those from Population III stars. To observe Population III caustic transits directly may require monitoring 3–30 lensing clusters to {AB}≲ 29 mag over a decade.

Preliminary study of efficacy of hyaluronic acid on caustic esophageal burns in an experimental rat model.

PubMed

Cevik, Muazez; Demir, Tuncer; Karadag, Cetin Ali; Ketani, Muzaffer Aydin; Celik, Hakim; Kaplan, Davut Sinan; Boleken, Mehmet Emin

2013-04-01

The aim of this study was to investigate the effectiveness of hyaluronic acid on the prevention of esophageal damage and stricture formation after experimental caustic (alkaline) esophageal injury in rats. Twenty-one Wistar albino rats were randomly divided into three groups. A caustic esophageal burn was created following the Gehanno model: Group l (n=7) underwent operation, but no injury; Group 2 (n=7) was injured and left untreated; and Group 3 (n=7) was injured and treated with hyaluronic acid, first topically and then orally by gavage (2×0.3mL; 12.5mg/mL for 7days). The caustic esophageal burn was created by instilling 25% NaOH into the distal esophagus. All rats were euthanized on day 22 for evaluation. The efficacy of hyaluronic acid treatment was assessed histopathologically and biochemically via blood determination of the total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), and sulfhydryl group (SH) and lipid hydroperoxidase (LOOH) levels. Statistical analyses were performed. Weight gain was significantly lower in Group 2 than in the other two groups (P<0.05). The mean stenosis index, histopathologic damage score, TAS, TOS, OSI, and SH and LOOH levels were higher in Group 2 than in the other two groups. The mean stenosis index, inflammation, TAS, SH and OSI in Group 2 were significantly different than those in the other two groups (P<0.05). Hyaluronic acid treatment is effective in treating damage and preventing strictures after caustic esophageal burn in rats. Copyright © 2013 Elsevier Inc. All rights reserved.

Revealing stellar brightness profiles by means of microlensing fold caustics

NASA Astrophysics Data System (ADS)

Dominik, M.

2004-09-01

With a handful of measurements of limb-darkening coefficients, galactic microlensing has already proven to be a powerful technique for studying atmospheres of distant stars. Survey campaigns such as OGLE-III are capable of providing ~10 suitable target stars per year that undergo microlensing events involving passages over the caustic created by a binary lens, which last from a few hours to a few days and allow us to resolve the stellar atmosphere by frequent broad-band photometry. For a caustic exit lasting 12 h and a photometric precision of 1.5 per cent, a moderate sampling interval of 30 min (corresponding to ~25-30 data points) is sufficient for providing a reliable measurement of the linear limb-darkening coefficient Γ with an uncertainty of ~8 per cent, which reduces to ~3 per cent for a reduced sampling interval of 6 min for the surroundings of the end of the caustic exit. While some additional points over the remaining parts of the light curve are highly valuable, a denser sampling in these regions provides little improvement. Unless an accuracy of less than 5 per cent is desired, limb-darkening coefficients for several filters can be obtained or observing time can be spent on other targets during the same night. The adoption of an inappropriate stellar brightness profile as well as the effect of acceleration between source and caustic yield distinguishable characteristic systematics in the model residuals. Acceleration effects are unlikely to affect the light curve significantly for most events, although a free acceleration parameter blurs the limb-darkening measurement if the passage duration cannot be accurately determined.

Improvement of Leaching Resistance of Low-level Waste Form in Korea

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

Kim, J.Y.; Lee, B.C.; Kim, C.L.

2006-07-01

Low-level liquid concentrate wastes including boric acid have been immobilized with paraffin wax using concentrate waste drying system in Korean nuclear power plants since 1995. Small amount of low density polyethylene (LDPE) was added to increase the leaching resistance of the existing paraffin waste form and the influence of LDPE on the leaching behavior of waste form was investigated. It was observed that the leaching of nuclides immobilized within paraffin waste form remarkably reduced as the content of LDPE increased. The acceptance criteria of paraffin waste form associated with leachability index and compressive strength after the leaching test were successfullymore » satisfied with the help of LDPE. (authors)« less

Zinc Leaching from Tire Crumb Rubber

NASA Astrophysics Data System (ADS)

Rhodes, E. P.; Ren, J.; Mays, D. C.

2010-12-01

Recent estimates indicate that more than 2 billion scrap tires are currently stockpiled in the United States and approximately 280 million more tires are added annually. Various engineering applications utilize recycled tires in the form of shredded tire crumb rubber. However, the use of tire crumb rubber may have negative environmental impacts, especially when the rubber comes into contact with water. A review of the literature indicates that leaching of zinc from tire crumb rubber is the most significant water quality concern associated with using this material. Zinc is generally used in tire manufacturing, representing approximately 1.3% of the final product by mass. This study will report results from the U.S. Environmental Protection Agency’s (EPA’s) Synthetic Precipitation Leaching Procedure, batch leaching tests, and column leaching tests performed to quantify the process by which zinc leaches from tire crumb rubber into water. Results are interpreted with a first-order kinetic attachment/detachment model, implemented with the U.S. Agricultural Research Service software HYDRUS-1D, in order to determine the circumstances when zinc leaching from tire crumb rubber would be expected to comply with the applicable discharge limits. One potential application for recycled tires is replacing sand with tire crumb rubber in granular media filters used for stormwater pollution control. For this to be a viable application, the total zinc in the stormwater discharge must be below the EPA’s benchmark value of 0.117 mg/L.

Worldwide Environmental Compliance Assessment System (ECAS)

DTIC Science & Technology

1993-03-01

and other Pickling liquor and other corrosive alkalies corrosive acids Lime wastewater Spent acid Lime and water Spent mixed acid Spent caustic Spent ...labeling. packag- ing. and spill response for hazardous materials? 4. Does the installation store: * a. acids? b. caustics ? c. flammables? d. combustibles...USEPA Hazardous Waste Hazard Waste Code No. FOOl The following spent halokenated solvents used in degreasing: tetra- (T) chloroethylene, trichloroethylene

Simulations of sonic boom ray tube area fluctuations for propagation through atmospheric turbulence including caustics via a Monte Carlo method

NASA Technical Reports Server (NTRS)

Sparrow, Victor W.; Pierce, Allan D.

1992-01-01

A theory which gives statistical predictions for how often sonic booms propagating through the earth's turbulent boundary layer will encounter caustics, given the spectral properties of the atmospheric turbulence, is outlined. The theory is simple but approximately accounts for the variation of ray tube areas along ray paths. This theory predicts that the variation of ray tube areas is determined by the product of two similar area factors, psi (x) and phi (x), each satisfying a generic harmonic oscillator equation. If an area factor increases the peak acoustic pressure decreases, and if the factor decreases the peak acoustic pressure increases. Additionally, if an area factor decreases to zero and becomes negative, the ray has propagated through a caustic, which contributes a phase change of 90 degrees to the wave. Thus, it is clear that the number of times that a sonic boom wave passes through a caustic should be related to the distorted boom waveform received on the ground. Examples are given based on a characterization of atmospheric turbulence due to the structure function of Tatarski as modified by Crow.

Caustics and Rogue Waves in an Optical Sea.

PubMed

Mathis, Amaury; Froehly, Luc; Toenger, Shanti; Dias, Frédéric; Genty, Goëry; Dudley, John M

2015-08-06

There are many examples in physics of systems showing rogue wave behaviour, the generation of high amplitude events at low probability. Although initially studied in oceanography, rogue waves have now been seen in many other domains, with particular recent interest in optics. Although most studies in optics have focussed on how nonlinearity can drive rogue wave emergence, purely linear effects have also been shown to induce extreme wave amplitudes. In this paper, we report a detailed experimental study of linear rogue waves in an optical system, using a spatial light modulator to impose random phase structure on a coherent optical field. After free space propagation, different random intensity patterns are generated, including partially-developed speckle, a broadband caustic network, and an intermediate pattern with characteristics of both speckle and caustic structures. Intensity peaks satisfying statistical criteria for rogue waves are seen especially in the case of the caustic network, and are associated with broader spatial spectra. In addition, the electric field statistics of the intermediate pattern shows properties of an "optical sea" with near-Gaussian statistics in elevation amplitude, and trough-to-crest statistics that are near-Rayleigh distributed but with an extended tail where a number of rogue wave events are observed.

Caustics and Rogue Waves in an Optical Sea

PubMed Central

Mathis, Amaury; Froehly, Luc; Toenger, Shanti; Dias, Frédéric; Genty, Goëry; Dudley, John M.

2015-01-01

There are many examples in physics of systems showing rogue wave behaviour, the generation of high amplitude events at low probability. Although initially studied in oceanography, rogue waves have now been seen in many other domains, with particular recent interest in optics. Although most studies in optics have focussed on how nonlinearity can drive rogue wave emergence, purely linear effects have also been shown to induce extreme wave amplitudes. In this paper, we report a detailed experimental study of linear rogue waves in an optical system, using a spatial light modulator to impose random phase structure on a coherent optical field. After free space propagation, different random intensity patterns are generated, including partially-developed speckle, a broadband caustic network, and an intermediate pattern with characteristics of both speckle and caustic structures. Intensity peaks satisfying statistical criteria for rogue waves are seen especially in the case of the caustic network, and are associated with broader spatial spectra. In addition, the electric field statistics of the intermediate pattern shows properties of an “optical sea” with near-Gaussian statistics in elevation amplitude, and trough-to-crest statistics that are near-Rayleigh distributed but with an extended tail where a number of rogue wave events are observed. PMID:26245864

Thermal degradation of the solvent employed in the next-generation caustic-side solvent extraction process and its effect on the extraction, scrubbing, and stripping of cesium

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

Roach, Benjamin D.; Williams, Neil J.; Moyer, Bruce A.

As part of the ongoing development of the Next-Generation Caustic-Side Solvent Extraction (NGS) process, the thermal stability of the process solvent was investigated and shown to be adequate for industrial application. The solvent was thermally treated at 35 C over a period of 13 months whilst in dynamic contact with each of the aqueous phases of the current NGS process, namely SRS 15 (a highly caustic waste simulant), sodium hydroxide scrub solution (0.025 M), and boric acid strip solution (0.01 M). The effect of thermal treatment was evaluated by assessing batch extract/scrub/strip performance as a function of time, by monitoringmore » the sodium extraction capacity of the solvent, and by analysis of the solvent using electrospray mass spectrometry. Current studies indicate that the NGS solvent should be thermally robust for a period of XXX months at the Modular Caustic-Side Solvent Extraction Unit (MCU) pilot plant located at Savannah River Site. Furthermore, the guanidine suppressor appears to be the solvent component most significantly impacted by thermal treatment of the solvent, showing significant degradation over time.« less

Thermal degradation of the solvent employed in the next-generation caustic-side solvent extraction process and its effect on the extraction, scrubbing, and stripping of cesium

DOE PAGES

Roach, Benjamin D.; Williams, Neil J.; Moyer, Bruce A.

2015-09-02

As part of the ongoing development of the Next-Generation Caustic-Side Solvent Extraction (NGS) process, the thermal stability of the process solvent was investigated and shown to be adequate for industrial application. The solvent was thermally treated at 35 C over a period of 13 months whilst in dynamic contact with each of the aqueous phases of the current NGS process, namely SRS 15 (a highly caustic waste simulant), sodium hydroxide scrub solution (0.025 M), and boric acid strip solution (0.01 M). The effect of thermal treatment was evaluated by assessing batch extract/scrub/strip performance as a function of time, by monitoringmore » the sodium extraction capacity of the solvent, and by analysis of the solvent using electrospray mass spectrometry. Current studies indicate that the NGS solvent should be thermally robust for a period of XXX months at the Modular Caustic-Side Solvent Extraction Unit (MCU) pilot plant located at Savannah River Site. Furthermore, the guanidine suppressor appears to be the solvent component most significantly impacted by thermal treatment of the solvent, showing significant degradation over time.« less

Backscattering from targets residing in caustics resulting from ocean boundary interactions

NASA Astrophysics Data System (ADS)

Dzikowicz, Benjamin R.; Marston, Philip L.

2005-04-01

Detection of targets by backscatter in shallow water can be enhanced by interactions with ocean boundaries. A laboratory experiment is performed where a spherical target passes through an Airy caustic formed by a curved surface. When the target resides in the insonified region of the caustic there are two sets of multi-path rays: two pairs reflecting once off the surface (either to or from the target), and three reflecting twice off the surface (to and from the target). When a target moves across the caustic the singly reflected rays merge, as do the doubly reflected. With a longer tone burst the rays in each set overlap and the backscatter is greatly enhanced as the target moves into the insonified region. For a point target the singly reflected backscatter scales as an Airy function [B. R. Dzikowicz and P. L. Marston, J. Acoust. Soc. Am. 116, 2751-2757 (2004)], and the doubly reflected as the square of an Airy function. For a finite target the doubly reflected backscatter unfolds into a hyperbolic umbilic function. The arguments of the Airy and Hyperbolic Umbilic functions are calculated using the relative echo times of transient pulses. [Work supported by ONR.

[Acquired caustic vagina stenosis: Surgical outcomes of 21 cases].

PubMed

Séni, K; Horo, A G; Koffi, A; Aka, K E; Fomba, M; Koné, M

2016-03-01

To document epidemiology, causes, anatomical varieties and surgical management outcomes of caustic acquired vagina stenosis. Retrospective study of 21 patients involved from 1996 to 2012 at the department of obstetrics and gynecology of Yopougon's teaching hospital in Abidjan, Côte d'Ivoire. Vaginal stenosis due to genital malformation, vaginal irradiation of pelvic tumours, repair of bladder and vaginal fistulae or intersexual disorders were excluded. The prevalence was 0.14/1000 admissions, mean age was 32.1 years, mean gravidity was 1.76 and mean parity was 1.1. Vaginal stenosis seat and extent were variable and 100 % had a caustic origin by use of traditional medicine vaginal pessaire. Of the patients, 95.2 % underwent surgical treatment followed by several dilations sessions with glass dilators. Successful surgical outcome allowing coitus was achieved in 47.6 % of cases with 52.4 % failure. Acquired caustic vagina stenosis are frequently occurring and are a public health problem related to ignorance. Health education and establishment of expert centers with exchange of experiences in West Africa should be able to improve surgical outcomes. Copyright © 2016. Published by Elsevier SAS.

Leaching of cadmium and tellurium from cadmium telluride (CdTe) thin-film solar panels under simulated landfill conditions

PubMed Central

Ramos-Ruiz, Adriana; Wilkening, Jean V.; Field, James A.; Sierra-Alvarez, Reyes

2017-01-01

A crushed non-encapsulated CdTe thin-film solar cell was subjected to two standardized batch leaching tests (i.e., Toxicity Characteristic Leaching Procedure (TCLP) and California Waste Extraction Test (WET)) and to a continuous-flow column test to assess cadmium (Cd) and tellurium (Te) dissolution under conditions simulating the acidic- and the methanogenic phases of municipal solid waste landfills. Low levels of Cd and Te were solubilized in both batch leaching tests (<8.2% and <3.6% of added Cd and Te, respectively). On the other hand, over the course of 30 days, 73% of the Cd and 21% of the Te were released to the synthetic leachate of a continuous-flow column simulating the acidic landfill phase. The dissolved Cd concentration was 3.24-fold higher than the TCLP limit (1 mg L-1), and 650-fold higher than the maximum contaminant level established by the US-EPA for this metal in drinking water (0.005 mg L-1). In contrast, the release of Cd and Te to the effluent of the continuous-flow column simulating the methanogenic phase of a landfill was negligible. The remarkable difference in the leaching behavior of CdTe in the columns is related to different aqueous pH and redox conditions promoted by the microbial communities in the columns, and is in agreement with thermodynamic predictions. PMID:28472709

Impact assessment of fly ash on ground water quality: An experimental study using batch leaching tests.

PubMed

Dandautiya, Rahul; Singh, Ajit Pratap; Kundu, Sanghamitra

2018-05-01

The fly ash, generated at the coal-based thermal power plant, is always a cause of concern to environmentalists owing to its adverse impact on air, water and land. There exists a high environmental risk when it is disposed to the environment. Thus, two different type of fly ash samples (FA-1 and FA-2) have been considered in this study to examine the leaching potential of the elements magnesium, aluminium, silicon, calcium, titanium, vanadium, chromium, manganese, iron, nickel, cobalt, copper, zinc, arsenic, selenium, strontium, cadmium, barium and lead for different types of leachant. Toxicity characteristics leaching procedure and ASTM tests have been performed in the laboratory to simulate different natural leaching scenarios. Characterisation of samples have been done through X-ray diffraction and field emission gun scanning electron microscope. The effect of different liquid to solid ratios (i.e. 5, 10, 20 and 50) on the mobilisation of elements has been analysed. The results indicated that the maximum leaching of all elements occurred at a liquid to solid ratio of 5 except for arsenic, barium and silicon. The groundwater analysis has also been done to understand the actual effects of leachate. The elements presenting the highest leachability in the two fly ash samples under all tested conditions were magnesium, aluminium, silicon and calcium. It has been observed that calcium exhibits greater leaching effects than all other constituents. The study presented here has been found very useful for assessing contamination levels in groundwater owing to leaching effects of fly ash under different scenarios, which can be helpful to prevent spreading of the contaminants by efficient management of fly ash.

Arsenic-containing soil from geogenic source in Hong Kong: Leaching characteristics and stabilization/solidification.

PubMed

Li, Jiang-Shan; Beiyuan, Jingzi; Tsang, Daniel C W; Wang, Lei; Poon, Chi Sun; Li, Xiang-Dong; Fendorf, Scott

2017-09-01

Geogenic sources of arsenic (As) have aroused extensive environmental concerns in many countries. This study evaluated the vertical profiles, leaching characteristics, and surface characteristics of As-containing soils in Hong Kong. The results indicated that elevated levels of As (486-1985 mg kg -1 ) were mostly encountered in deeper layer (15-20 m below ground). Despite high concentrations, geogenic As displayed a high degree of chemical stability in the natural geochemical conditions, and there was minimal leaching of As in various leaching tests representing leachability, mobility, phytoavailability, and bioaccessibility. Microscopic/spectroscopic investigations suggested that As in the soils was predominantly present as As(V) in a coordination environment with Fe oxides. Sequential extraction indicated that the majority of As were strongly bound with crystalline Fe/Al oxides and residual phase. Yet, uncertainties may remain with potential As exposure through accidental ingestion and abiotic/biotic transformation due to changes in geochemical conditions. Hence, the effectiveness of stabilization/solidification (S/S) treatment was evaluated. Although the leached concentrations of As from the S/S treated soils increased to varying extent in different batch leaching tests due to the increase in alkalinity, the mobility of As was considered very low based on semi-dynamic leaching test. This suggested that As immobilization in the S/S treated soils was predominantly dependent on physical encapsulation by interlocking framework of hydration products, which could also prevent potential exposure and allow controlled utilization of S/S treated soils as monolithic materials. These results illustrate the importance of holistic assessment and treatment/management of As-containing soils for enabling flexible future land use. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Leaching characteristics of heavy metals and utilization of filter media in BAF].

PubMed

Zou, Jin-long; Dai, Ying

2007-10-01

A series of leaching tests were conducted to study the solidification of heavy metals in biological filter media made with dried sludge as an additive. The maximum leaching contents of Cd, Cr, Cu and Pb are obtained when pH is 1; leaching contents of heavy metals have an obvious decrease as pH is greater than or equal to 3; and it can be concluded from the results that pH has a significant influence on the leaching characteristic of heavy metals at leaching time of either 24 h or 30 d. X-ray diffraction analysis performed on filter media reveal the main compounds of the 4 heavy metals are Pb2O(CrO4), CdSiO3 and CuO, and the heavy metals are solidified in the mesh structure of Si--O. Heavy metals (such as Cd, Cr, Cu and Pb) can be solidified in filter media through a series of crystalline phase changes and chemical reaction after high temperature sintering. The new filter media (obtained in test) were used in biological aerated filter (BAF) to treat wastewater (C/N about 11.5 and 25.5) in a simultaneous nitrification and denitrification (SND) system. Based on the mechanism of SND, the average removal efficienciesof NH4(+)-N and TN filled with the new filter media (obtained in test) are about 85.5%, 90.3%, 46.6% and 49.6%, respectively, and it is higher than those of other 3 medias (Jiangxi ceramsite, Guangzhou ceramsite and Shanxi activated carbon). The results provide a better understanding of factors that may affect the immobilization and leaching characteristics of heavy metals in ceramsite, which promotes the extensive use of filter media in BAF.

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.

Coatings to reduce wood preservative leaching.

PubMed

Nejad, Mojgan; Cooper, Paul

2010-08-15

The efficiency of semitransparent penetrating stains to reduce leaching of wood preservative components was evaluated. Five commercial wood deck finishes were applied to untreated and chromated copper arsenate (CCA), alkaline copper quat (ACQ), and copper azole (CA) treated wood, and leachates were collected and analyzed during 3 years of natural weathering exposure in Toronto, Canada. All stains evaluated effectively reduced the cumulative leaching of all inorganic preservative components by about 60% on average. Although most coatings showed significant film degradation starting around 12 months, the reduced leaching persisted even after 3 years. This suggests that temporary protection of wood with a coating during the early stages of use resulted in long-term reduction in preservative leaching potential. A two-week screening leaching test was able to predict the long-term leaching performance of different coatings reasonably well. Cured coating glass transition temperature (Tg) and liquid coating viscosity were the most important variables affecting a leaching prediction model. To effectively reduce leaching of preservative components from treated wood, coatings should have Tg low enough to withstand stresses caused by freezing in winter and have adequate viscosity to form a barrier film layer on the wood surface.

Miscibility Evaluation Of The Next Generation Solvent With Polymers Currently Used At DWPF, MCU, And Saltstone

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

Fondeur, F. F.

The Office of Waste Processing, within the Office of Technology Innovation and Development, funded the development of an enhanced Caustic-Side Solvent Extraction (CSSX) solvent for deployment at the Savannah River Site for removal of cesium from High Level Waste. This effort lead to the development of the Next Generation Solvent (NGS) with Tris (3,7-dimethyl octyl) guanidine (TiDG). The first deployment target for the NGS solvent is within the Modular CSSX Unit (MCU). Deployment of a new chemical within an existing facility requires verification that the new chemical components are compatible with the installed equipment. In the instance of a newmore » organic solvent, the primary focus is on compatibility of the solvent with organic polymers used in the affected facility. This report provides the calculated data from exposing these polymers to the Next Generation Solvent. An assessment of the dimensional stability of polymers known to be used or present in the MCU, Defense Waste Processing Facility (DWPF), and Saltstone facilities that will be exposed to the NGS showed that TiDG could selectively affect the elastomers and some thermoplastics to varying extents, but the typical use of these polymers in a confined geometry will likely prevent the NGS from impacting component performance. The polymers identified as of primary concern include Grafoil® (flexible graphite), Tefzel®, Isolast®, ethylene-propylene-diene monomer (EPDM) rubber, nitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), ultra high molecular weight polyethylene (UHMWPE), and fluorocarbon rubber (FKM). Certain polymers like NBR and EPDM were found to interact mildly with NGS but their calculated swelling and the confined geometry will impede interaction with NGS. In addition, it was found that Vellumoid (cellulose fibers-reinforced glycerin and protein) may leach protein and Polyvinyl Chloride (PVC) may leach plasticizer (such as Bis-Ethylhexyl-Phthalates) into the NGS solvent. Either case will not impact decontamination or immobilization operations at Savannah River Site (SRS). Some applications have zero tolerance for dimensional changes such as the operation of valves while other applications a finite dimensional change improves the function of the application such as seals and gaskets. Additional considerations are required before using the conclusions from this work to judge outcomes in field applications. Decane, a component of Isopar L that is most likely to interact with the polymers, mildly interacted with the elastomers and the propylene based polymers but their degree of swelling is at most 10% and the confined geometry that they are typically placed in indicate this is not significant. In addition, it was found that Vellumoid may leach protein into the NGS solvent. Since Vellumoid is used at the mixer in Saltstone where it sees minimum quantities of solvent, this leaching has no effect on the extraction process at MCU or the immobilization process at saltstone. No significant interaction is expected between MaxCalix and the polymers and elastomers used at MCU, DWPF, and Saltstone. Overall, minimal and insignificant interactions are expected on extraction and immobilization operations when MCU switches from CSSX to NGS solvent. It is expected that contacting NGS will not accelerate the aging rate of polymers and elastomers under radiation and heat. This is due to the minimal interaction between NGS and the polymers and the confined geometries for these polymers. SRNL recommends the use of the HSP method (for screening) and some testing to evaluate the impact of other organic such as alcohols, glycolate, and their byproducts on the polymers used throughout the site.« less

Thermodynamic model for uranium release from hanford site tank residual waste.

PubMed

Cantrell, Kirk J; Deutsch, William J; Lindberg, Mike J

2011-02-15

A thermodynamic model of U solid-phase solubility and paragenesis was developed for Hanford Site tank residual waste that will remain in place after tank closure. The model was developed using a combination of waste composition data, waste leach test data, and thermodynamic modeling of the leach test data. The testing and analyses were conducted using actual Hanford Site tank residual waste. Positive identification of U phases by X-ray diffraction was generally not possible either because solids in the waste were amorphous or their concentrations were not detectable by XRD for both as-received and leached residual waste. Three leachant solutions were used in the studies: deionized water, CaCO3 saturated solution, and Ca(OH)2 saturated solution. Analysis of calculated saturation indices indicate that NaUO2PO4·xH2O and Na2U2O7(am) are present in the residual wastes initially. Leaching of the residual wastes with deionized water or CaCO3 saturated solution results in preferential dissolution Na2U2O7(am) and formation of schoepite. Leaching of the residual wastes with Ca(OH)2 saturated solution appears to result in transformation of both NaUO2PO4·xH2O and Na2U2O7(am) to CaUO4. Upon the basis of these results, the paragenetic sequence of secondary phases expected to occur as leaching of residual waste progresses for two tank closure scenarios was identified.

Non-combustible waste vitrification with plasma torch melter.

PubMed

Park, J K; Moon, Y P; Park, B C; Song, M J; Ko, K S; Cho, J M

2001-05-01

Non-combustible radioactive wastes generated from Nuclear Power Plants (NPPs) are composed of concrete, glass, asbestos, metal, sand, soil, spent filters, etc. The melting tests for concrete, glass, sand, and spent filters were carried out using a 60 kW plasma torch system. The surrogate wastes were prepared for the tests. Non-radioactive Co and Cs were added to the surrogates in order to simulate the radioactive waste. Several kinds of surrogate prepared by their own mixture or by single waste were melted with the plasma torch system to produce glassy waste forms. The characteristics of glassy waste forms were examined for the volume reduction factor (VRF) and the leach rate. The VRFs were estimated through the density measurement of the surrogates and the glassy waste forms, and were turned out to be 1.2-2.4. The EPA (Environmental Protection Agency) Toxicity Characteristic Leaching Procedure (TCLP) was used to determine the leach resistance for As, Ba, Hg, Pb, Cd, Cr, Se, Co, and Cs. The leaching index was calculated using the total content of each element in both the waste forms and the leachant. The TCLP tests resulted in that the leach rates for all elements except Co and Cs were lower than those of the Universal Treatment Standard (UTS) limits. There were no UTS limits for Co and Cs, and their leach rate & index from the experiments were resulted in around 10 times higher than those of other elements.

Bioleaching of rare earth elements from waste phosphors and cracking catalysts

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

Reed, David W.; Fujita, Yoshiko; Daubaras, Dayna L.

Four microbial cultures were evaluated for organic acid production and their potential utility for leaching of rare earth elements (REE) from retorted phosphor powder (RPP) and spent fluidized cracking catalyst (FCC). Three of the cultures (2 bacterial, 1 fungal) were isolated from environmental and industrial materials known to contain rare earth elements. The other was the well-known and industrially important bacterium Gluconobacter oxydans. Gluconic acid was the predominant identified organic acid produced by all of the cultures; citric and acetic acid were among the other acids detected. There was also maximum REE leaching by cell free culture supernatants obtained withmore » Gluconobacter and the FCC; 49% of total REE was recovered, with preferential recovery of lanthanum over cerium. The phosphor powder was more difficult to leach; only ~2 % total REE was leached from RPP with Gluconobacter. Tests with the RPP indicated that the extent of REE solubilization was similar whether whole cell cultures or cell-free supernatants were used. However, Gluconobacter cell-free culture supernatants with 10-15 mM gluconic acid outperformed abiotically prepared leaching solutions with 30 mM gluconic acid concentrations. Abiotic tests showed that increasing gluconic acid concentrations increased leaching efficiency; for example, total REE leaching from FCC increased from 24 to 36 to 45% when gluconic acid was increased from 10 to 30 to 90 mM. Our research shows that utilizing microorganisms that produce gluconic acid can result in effective leaching of REE from waste materials, and optimizing gluconic acid production will improve recovery.« less

Bioleaching of rare earth elements from waste phosphors and cracking catalysts

DOE PAGES

Reed, David W.; Fujita, Yoshiko; Daubaras, Dayna L.; ...

2016-08-22

Four microbial cultures were evaluated for organic acid production and their potential utility for leaching of rare earth elements (REE) from retorted phosphor powder (RPP) and spent fluidized cracking catalyst (FCC). Three of the cultures (2 bacterial, 1 fungal) were isolated from environmental and industrial materials known to contain rare earth elements. The other was the well-known and industrially important bacterium Gluconobacter oxydans. Gluconic acid was the predominant identified organic acid produced by all of the cultures; citric and acetic acid were among the other acids detected. There was also maximum REE leaching by cell free culture supernatants obtained withmore » Gluconobacter and the FCC; 49% of total REE was recovered, with preferential recovery of lanthanum over cerium. The phosphor powder was more difficult to leach; only ~2 % total REE was leached from RPP with Gluconobacter. Tests with the RPP indicated that the extent of REE solubilization was similar whether whole cell cultures or cell-free supernatants were used. However, Gluconobacter cell-free culture supernatants with 10-15 mM gluconic acid outperformed abiotically prepared leaching solutions with 30 mM gluconic acid concentrations. Abiotic tests showed that increasing gluconic acid concentrations increased leaching efficiency; for example, total REE leaching from FCC increased from 24 to 36 to 45% when gluconic acid was increased from 10 to 30 to 90 mM. Our research shows that utilizing microorganisms that produce gluconic acid can result in effective leaching of REE from waste materials, and optimizing gluconic acid production will improve recovery.« less

Estimation of Cadmium uptake by tobacco plants from laboratory leaching tests.

PubMed

Marković, Jelena P; Jović, Mihajlo D; Smičiklas, Ivana D; Šljivić-Ivanović, Marija Z; Smiljanić, Slavko N; Onjia, Antonije E; Popović, Aleksandar R

2018-03-21

The objective of the present study was to determine the impact of cadmium (Cd) concentration in the soil on its uptake by tobacco plants, and to compare the ability of diverse extraction procedures for determining Cd bioavailability and predicting soil-to-plant transfer and Cd plant concentrations. The pseudo-total digestion procedure, modified Tessier sequential extraction and six standard single-extraction tests for estimation of metal mobility and bioavailability were used for the leaching of Cd from a native soil, as well as samples artificially contaminated over a wide range of Cd concentrations. The results of various leaching tests were compared between each other, as well as with the amounts of Cd taken up by tobacco plants in pot experiments. In the native soil sample, most of the Cd was found in fractions not readily available under natural conditions, but with increasing pollution level, Cd amounts in readily available forms increased. With increasing concentrations of Cd in the soil, the quantity of pollutant taken up in tobacco also increased, while the transfer factor (TF) decreased. Linear and non-linear empirical models were developed for predicting the uptake of Cd by tobacco plants based on the results of selected leaching tests. The non-linear equations for ISO 14870 (diethylenetriaminepentaacetic acid extraction - DTPA), ISO/TS 21268-2 (CaCl 2 leaching procedure), US EPA 1311 (toxicity characteristic leaching procedure - TCLP) single step extractions, and the sum of the first two fractions of the sequential extraction, exhibited the best correlation with the experimentally determined concentrations of Cd in plants over the entire range of pollutant concentrations. This approach can improve and facilitate the assessment of human exposure to Cd by tobacco smoking, but may also have wider applicability in predicting soil-to-plant transfer.

Leachability of Cr(VI) and other metals from asphalt composites with addition of filter dust.

PubMed

Vahcic, Mitja; Milacic, Radmila; Mladenovic, Ana; Murko, Simona; Zuliani, Tea; Zupancic, Marija; Scancar, Janez

2008-12-01

The potential use of filter dust in asphalt composites for road construction was investigated. Filter dust contains high concentrations of metals, of which Cr(VI) and Pb are leached with water. Compact and ground asphalt composites with addition of 2% of filter dust by mass were studied. In order to evaluate their environmental impact, leachability tests were performed using water and salt water as leaching agents. The concentrations of Cr(VI) and Pb were determined in leachates over a time period of 182 days. The results indicated that Pb was not leached with leaching agents from asphalt composites. Cr(VI) was also not leached with leaching agents from compact asphalt composites. However, in ground asphalt composites, Cr(VI) was leached with water in concentrations up to 220 microg L(-1) and in salt water up to 150 microg L(-1). From the physico-mechanical and environmental aspects, filter dust can be used as a component in asphalt mixtures.

Study on Cr(VI) Leaching from Cement and Cement Composites

PubMed Central

Palascakova, Lenka; Kanuchova, Maria

2018-01-01

This paper reports an experimental study on hexavalent chromium leaching from cement samples and cement composites containing silica fume and zeolite additions that were subjected to various leaching agents. The water-soluble Cr(VI) concentrations in cements ranged from 0.2 to 3.2 mg/kg and represented only 1.8% of the total chromium content. The presence of chromium compounds with both chromium oxidation states of III and VI was detected in the cement samples by X-ray photoelectron spectroscopy (XPS). Leaching tests were performed in a Britton-Robinson buffer to simulate natural conditions and showed increased dissolution of Cr(VI) up to 6 mg/kg. The highest amount of leached hexavalent chromium was detected after leaching in HCl. The findings revealed that the leaching of chromium from cements was higher by 55–80% than that from the cement composites. A minimum concentration was observed for all cement samples when studying the relationship between the soluble Cr(VI) and the cement storage time. PMID:29690550

Study on Cr(VI) Leaching from Cement and Cement Composites.

PubMed

Estokova, Adriana; Palascakova, Lenka; Kanuchova, Maria

2018-04-22

This paper reports an experimental study on hexavalent chromium leaching from cement samples and cement composites containing silica fume and zeolite additions that were subjected to various leaching agents. The water-soluble Cr(VI) concentrations in cements ranged from 0.2 to 3.2 mg/kg and represented only 1.8% of the total chromium content. The presence of chromium compounds with both chromium oxidation states of III and VI was detected in the cement samples by X-ray photoelectron spectroscopy (XPS). Leaching tests were performed in a Britton-Robinson buffer to simulate natural conditions and showed increased dissolution of Cr(VI) up to 6 mg/kg. The highest amount of leached hexavalent chromium was detected after leaching in HCl. The findings revealed that the leaching of chromium from cements was higher by 55⁻80% than that from the cement composites. A minimum concentration was observed for all cement samples when studying the relationship between the soluble Cr(VI) and the cement storage time.

Scoping candidate minerals for stabilization of arsenic-bearing solid residuals.

PubMed

Raghav, Madhumitha; Shan, Jilei; Sáez, A Eduardo; Ela, Wendell P

2013-12-15

Arsenic Crystallization Technology (ACT) is a potentially eco-friendly, effective technology for stabilization of arsenic-bearing solid residuals (ABSRs). The strategy is to convert ABSRs generated by water treatment facilities into minerals with a high arsenic capacity and long-term stability in mature, municipal solid waste landfills. Candidate minerals considered in this study include scorodite, arsenate hydroxyapatites, ferrous arsenates (symplesite-type minerals), tooeleite, and arsenated-schwertmannite. These minerals were evaluated as to ease of synthesis, applicability to use of iron-based ABSRs as a starting material, and arsenic leachability. The Toxicity Characteristic Leaching Procedure (TCLP) was used for preliminary assessment of candidate mineral leaching. Minerals that passed the TCLP and whose synthesis route was promising were subjected to a more aggressive leaching test using a simulated landfill leachate (SLL) solution. Scorodite and arsenate hydroxyapatites were not considered further because their synthesis conditions were not found to be favorable for general application. Tooeleite and silica-amended tooeleite showed high TCLP arsenic leaching and were also not investigated further. The synthesis process and leaching of ferrous arsenate and arsenated-schwertmannite were promising and of these, arsenated-schwertmannite was most stable during SLL testing. The latter two candidate minerals warrant synthesis optimization and more extensive testing. Copyright © 2013 Elsevier B.V. All rights reserved.

When an Elected Official Fails to Play Nice: The Legal Implications and Lessons Learned from Associations with a Caustic School Board Member

ERIC Educational Resources Information Center

Weiler, Spencer C.

2015-01-01

In November of 2009 Mr. Sean Lyndon was elected to the Verde Mountain School Board and by February 2012 he resigned from this position. During his tumultuous tenure, Mr. Lyndon's antics proved divisive, caustic, and disruptive to the governance process. These actions included belittling and intimidating fellow school board members and school…

Mineralogical determination and geo-chemical modeling of chromium release from AOD slag: Distribution and leachability aspects.

PubMed

Li, Junguo; Liu, Bao; Zeng, Yanan; Wang, Ziming

2017-01-01

AOD (argon oxygen decarburization) slag, which is the by-product of the stainless steel refining process, is a recyclable slag because of its high content of calcium and silicon. The leaching toxicity cannot be ignored in the recycling process because the slag contains a certain amount of Cr. In this study, the mineral analysis, batch leaching tests and thermodynamic and kinetic modeling by PHREEQC combined with FactSage software were performed to explore the influence of the dissolution of primary minerals and the precipitation of secondary minerals on the elution of Cr from AOD slag. The results indicated that the main minerals in the original AOD slag are larnite, merwinite, pyroxene and periclase. Cr was dispersed in the mineral phases mentioned above. The simulation of Cr leaching controlled by Cr(III)-hydroxide corresponded better to the batch leaching tests, while the Cr leaching controlled by chromite or double control was underestimated. Increasing the L/S ratio enhances the pH of the leachate and restrains the elution of Cr from the AOD slag. Copyright © 2016 Elsevier Ltd. All rights reserved.

Batch leaching tests of motherboards to assess environmental contamination by bromine, platinum group elements and other selected heavy metals.

PubMed

Almeida, César; Grosselli, Melina; González, Patricia; Martínez, Dante; Gil, Raúl

2016-02-01

In this study, a batch leaching test was executed to evaluate the toxicity associated with chemicals contained in motherboards. The leaching solutions used were distilled water, nitric acid, acetic acid and synthetic acid rain solution. A total of 21 elements including Ag, As, Au, Br, Cd, Co, Cr, Cu, Hf, Ir, Mn, Ni, Os, Pb, Pd, Pt, Rd, Rh, Se, U and Zn were analyzed. In this study, the pH values of all the leachates fell within the range of 2.33-4.88. The highest concentrations of metals were obtained from the acid rain solution, whilst the maximum value of bromine was achieved with solution of acetic acid. Appreciable concentrations of platinum group elements were detected with concentrations around 3.45, 1.43, 1.21 and 22.19 µg L(-1) for Ir, Pd, Pt and Rh, respectively. The different leaching of the motherboards revealed the predominant presence of the toxic substances in the leached from the e-waste. Copyright © 2015 Elsevier Ltd. All rights reserved.

Solid State Characterizations of Long-Term Leached Cast Stone Monoliths

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

Asmussen, Robert M.; Pearce, Carolyn I.; Parker, Kent E.

This report describes the results from the solid phase characterization of six Cast Stone monoliths from the extended leach tests recently reported on (Serne et al. 2016),that were selected for characterization using multiple state-of-the-art approaches. The Cast Stone samples investigated were leached for > 590 d in the EPA Method 1315 test then archived for > 390 d in their final leachate. After reporting the long term leach behavior of the monoliths (containing radioactive 99Tc and stable 127I spikes and for original Westsik et al. 2013 fabricated monoliths, 238U), it was suggested that physical changes to the waste forms andmore » a depleting inventory of contaminants of potential concern may mean that effective diffusivity calculations past 63 d should not be used to accurately represent long-term waste form behavior. These novel investigations, in both length of leaching time and application of solid state techniques, provide an initial arsenal of techniques which can be utilized to perform such Cast Stone solid phase characterization work, which in turn can support upcoming performance assessment maintenance. The work was performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to characterize several properties of the long- term leached Cast Stone monolith samples.« less

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

Not Available

This volume contains the interim change notice for sample preparation methods. Covered are: acid digestion for metals analysis, fusion of Hanford tank waste solids, water leach of sludges/soils/other solids, extraction procedure toxicity (simulate leach in landfill), sample preparation for gamma spectroscopy, acid digestion for radiochemical analysis, leach preparation of solids for free cyanide analysis, aqueous leach of solids for anion analysis, microwave digestion of glasses and slurries for ICP/MS, toxicity characteristic leaching extraction for inorganics, leach/dissolution of activated metal for radiochemical analysis, extraction of single-shell tank (SST) samples for semi-VOC analysis, preparation and cleanup of hydrocarbon- containing samples for VOCmore » and semi-VOC analysis, receiving of waste tank samples in onsite transfer cask, receipt and inspection of SST samples, receipt and extrusion of core samples at 325A shielded facility, cleaning and shipping of waste tank samplers, homogenization of solutions/slurries/sludges, and test sample preparation for bioassay quality control program.« less

Biodegradable Stents for Caustic Esophageal Strictures: Do They Work?

PubMed

Kochhar, Rakesh; Samanta, Jayanta; Basha, Jahangeer; Verma, Abhai; Choudhuri, Gourdas; Lakhtakia, Sundeep; Reddy, D Nageshwar

2017-08-01

Biodegradable (BD) stents have been used for the management of various esophageal strictures (ES) but the experience of its use in caustic strictures is limited. The present study, aimed at evaluating efficacy of BD stents for the treatment of refractory caustic-induced ES, was a retrospective multi-center study conducted at three tertiary care centers in India wherein adult patients with refractory caustic induced strictures underwent placement of a BD stent. Patients were followed up for immediate complications and long term outcome. All 13 patients (39.3 ± 15.1 years) underwent successful BD stent placement. Retrosternal chest pain occurred in 2 patients and stent migration in 1 (7.6%) patient. At 3 months, restenosis with recurrence of dysphagia was seen in nine (69.2%) patients, at 6 months, 10 (77%) patients had dysphagia of whom three underwent surgery and the remaining seven patients required dilatations. At 1 year, one patient remained asymptomatic while nine had dysphagia. The requirement for dilatation was once in 3 months in seven patients & once in a month in two patients. At 2 years, the requirement of dilatations was further reduced to once in 4-6 months in all patients. Over a 3 year follow up three (23%) patients had undergone surgery, one was free of symptoms while nine patients continued to be on periodic dilatation although the requirement had reduced to once in 4-6 months. Efficacy of BD stents in patients with caustic-induced ES is limited and the short term radial force applied by the currently available BD stents is inadequate to provide long term relief in such patients.

Early endoscopic balloon dilation in caustic-induced gastric injury.

PubMed

Kochhar, Rakesh; Poornachandra, Kuchhangi Sureshchandra; Dutta, Usha; Agrawal, Amit; Singh, Kartar

2010-04-01

There are no reports on endoscopic balloon dilation (EBD) for caustic-induced gastric outlet obstruction (GOO) in the acute or subacute phase. To study the efficacy of early EBD in patients with caustic-induced gastric injury. Tertiary care center in India. Retrospective analysis of data. Out of 41 patients with caustic-induced GOO who reported to us in the subacute phase between January 2001 and December 2008, 31 were treated by EBD. All 31 had ingested an acid 14.39 +/- 4.65 days earlier. EBD was achieved by using wire-guided balloons under endoscopic guidance. The balloon was negotiated across the narrowed segment and inflated for 60 seconds using a pressure gun. Balloons of incremental diameter, up to a maximum of 3 sizes, were used in each sitting. Procedural success was defined as reaching the end point of dilation (15 mm) and absence of symptoms. All 31 patients (18 male, mean age 32.06 +/- 11.04 years) could be successfully dilated. All but 1 underwent successful dilations to achieve the end point of 15 mm, requiring a median of 9 (range 3-18) dilations over a period of 7 (range 1.5-16) weeks. Complications included self-limiting pain (n = 10), bleeding at the time of the procedure (n = 9), and perforation in 1 patient (3.2%) who required surgery. Thirty patients were followed up for a median of 21 (range 3-72) months with no recurrence. Early EBD by an expert endoscopist is a safe and effective treatment modality in the management of caustic-induced GOO. Copyright 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

Two-Pole Caustic Model for High-Energy Lightcurves of Pulsars

NASA Technical Reports Server (NTRS)

Dyks, J.; Rudak, B.

2003-01-01

We present a new model of high-energy lightcurves from rotation powered pulsars. The key ingredient of the model is the gap region (i.e. the region where particle acceleration is taking place and high-energy photons originate) which satisfies the following assumptions: i) the gap region extends from each polar cap to the light cylinder; ii) the gap is thin and confined to the surface of last open magnetic-field lines; iii) photon emissivity is uniform within the gap region. The model lightcurves are dominated by strong peaks (either double or single) of caustic origin. Unlike in other pulsar models with caustic effects, the double peaks arise due to crossing two caustics, each of which is associated with a different magnetic pole. The generic features of the lightcurves are consistent with the observed characteristics of pulsar lightcurves: 1) the most natural (in terms of probability) shape consists of two peaks (separated by 0.4 to 0.5 in phase for large viewing angles); 2) the peaks possess well developed wings; 3) there is a bridge (inter-peak) emission component; 4) there is a non-vanishing off-pulse emission level; 5) the radio pulse occurs before the leading high-energy peak. The model is well suited for four gamma-ray pulsars - Crab, Vela, Geminga and B1951+32 - with double-peak lightcurves exhibiting the peak separation of 0.4 to 0.5 in phase. Hereby, we apply the model to the Vela pulsar. Moreover, we indicate the limitation of the model in accurate reproducing of the lightcurves with single pulses and narrowly separated (about 0.2 in phase) pulse peaks. We also discuss the optical polarization properties for the Crab pulsar in the context of the two-pole caustic model.

[Mixture Leaching Remediation Technology of Arsenic Contaminated Soil].

PubMed

Chen, Xun-feng; Li, Xiao-ming; Chen, Can; Yang, Qi; Deng, Lin-jing; Xie, Wei-qiang; Zhong, Yui; Huang, Bin; Yang, Wei-qiang; Zhang, Zhi-bei

2016-03-15

Soil contamination of arsenic pollution has become a severely environmental issue, while soil leaching is an efficient method for remediation of arsenic-contaminated soil. In this study, batch tests were primarily conducted to select optimal mixture leaching combination. Firstly, five conventional reagents were selected and combined with each other. Secondly, the fractions were analyzed before and after the tests. Finally, to explore the feasibility of mixed leaching, three soils with different arsenic pollution levels were used to compare the leaching effect. Comparing with one-step washing, the two-step sequential washing with different reagents increased the arsenic removal efficiency. These results showed that the mixture of 4 h 0.5 mol · L⁻¹ NaOH + 4 h 0.1 mol · L⁻¹ EDTA was found to be practicable, which could enhance the removal rate of arsenic from 66.67% to 91.83%, and the concentration of arsenic in soil was decreased from 186 mg · kg⁻¹ to 15.2 mg · kg⁻¹. Furthermore, the results indicated that the distribution of fractions of arsenic in soil changed apparently after mixture leaching. Leaching process could significantly reduce the available contents of arsenic in soil. Moreover, the mixture of 0.5 mol · L⁻¹ NaOH + 0.1 mol L⁻¹ EDTA could well decrease the arsenic concentration in aluminum-type soils, while the mixture of 0.5 mol · L⁻¹ OX + 0.5 mol · L⁻¹ NaOH could well decrease the arsenic concentration in iron-type soils.

Next Generation of Leaching Tests

EPA Science Inventory

A corresponding abstract has been cleared for this presentation. The four methods comprising the Leaching Environmental Assessment Framework are described along with the tools to support implementation of the more rigorous and accurate source terms that are developed using LEAF ...

Evolution of velocity dispersion along cold collisionless flows

DOE PAGES

Banik, Nilanjan; Sikivie, Pierre

2016-05-01

We found that the infall of cold dark matter onto a galaxy produces cold collisionless flows and caustics in its halo. If a signal is found in the cavity detector of dark matter axions, the flows will be readily apparent as peaks in the energy spectrum of photons from axion conversion, allowing the densities, velocity vectors and velocity dispersions of the flows to be determined. We also discuss the evolution of velocity dispersion along cold collisionless flows in one and two dimensions. A technique is presented for obtaining the leading behaviour of the velocity dispersion near caustics. The results aremore » used to derive an upper limit on the energy dispersion of the Big Flow from the sharpness of its nearby caustic, and a prediction for the dispersions in its velocity components.« less

Leaching of cadmium and tellurium from cadmium telluride (CdTe) thin-film solar panels under simulated landfill conditions.

PubMed

Ramos-Ruiz, Adriana; Wilkening, Jean V; Field, James A; Sierra-Alvarez, Reyes

2017-08-15

A crushed non-encapsulated CdTe thin-film solar cell was subjected to two standardized batch leaching tests (i.e., Toxicity Characteristic Leaching Procedure (TCLP) and California Waste Extraction Test (WET)) and to a continuous-flow column test to assess cadmium (Cd) and tellurium (Te) dissolution under conditions simulating the acidic- and the methanogenic phases of municipal solid waste landfills. Low levels of Cd and Te were solubilized in both batch leaching tests (<8.2% and <3.6% of added Cd and Te, respectively). On the other hand, over the course of 30days, 73% of the Cd and 21% of the Te were released to the synthetic leachate of a continuous-flow column simulating the acidic landfill phase. The dissolved Cd concentration was 3.24-fold higher than the TCLP limit (1mgL -1 ), and 650-fold higher than the maximum contaminant level established by the US-EPA for this metal in drinking water (0.005mgL -1 ). In contrast, the release of Cd and Te to the effluent of the continuous-flow column simulating the methanogenic phase of a landfill was negligible. The remarkable difference in the leaching behavior of CdTe in the columns is related to different aqueous pH and redox conditions promoted by the microbial communities in the columns, and is in agreement with thermodynamic predictions. Copyright © 2017 Elsevier B.V. All rights reserved.

Dissolution Behaviour of Metal Elements from Several Types of E-waste Using Leaching Test

NASA Astrophysics Data System (ADS)

Nor, Nik Hisyamudin Muhd; Amira Nordin, Nurul; Mohamad, Fariza; Jaibee, Shafizan; Ismail, Al Emran; Omar, Badrul; Fauzi Ahmad, Mohd; Rahim, Abd Khalil Abd; Kamaruddin, Muhamad Khalif Ikhwan Mohd; Turan, Faiz Mohd; Abu Bakar, Elmi; Yokoyama, Seiji

2017-08-01

Rapid development of the electrical and electronic was increasing annually due to the demand by the human being. Increasing production of electrical and electronic product led to the increasing of electric and electronic waste or can be called as the e-waste. The UN Environment Programme estimates that the world generates 20-50 million tons of the e-waste each year and the amount is raising three times faster than other forms of municipal waste. This study is focusing on the investigation of the dissolution behaviour of metal element from several types of e-waste by hydrometallurgical process. Leaching test was conducted on the e-waste by using acid as the reagent solution. Prior to the leaching test, manual dismantling, separation, and crushing process were carried out to the e-waste. The e-waste were characterized by Scanning Electron Microcopy (SEM) and the Energy Dispersive X-ray Spectroscopy (EDX) to define the elements inside the sample of e-waste. While the liquid residue from leaching test was analyzed by using Inductively Couple Plasma-Mass Spectrometer (ICP-MS) to define the dissolution behaviour of the metal element that contain in the e-waste. It was found that the longest time for dismantling process was the dismantling of laptop. The dissolution behaviour of Fe, Al, Zn and Pb elements in the e-waste has affected to the increase of pH. The increasing pH led to the reduction of the metals element during leaching process.

Rare earths recovery and gypsum upgrade from Florida phosphogypsum

DOE PAGES

Liang, Haijun; Zhang, Patrick; Jin, Zhen; ...

2017-11-01

Phosphogypsum is a byproduct created during the production of industrial wet-process phosphoric acid. This study focused on recovering rare earth elements (REEs) from a Florida phosphogypsum sample and investigated the effects of removing detrimental impurities such as phosphorus pentoxide (P 2O 5), uranium (U) and fluorine (F) during the leaching process. Experimental results indicated that REE leaching efficiency increased rapidly, reached a maximum and then began to decrease with sulfuric acid concentrations ranging from 0 to 10 percent and temperatures ranging from 20 to 70 °C. At a sulfuric acid concentration of 5 percent and leaching temperature of 50 °C,more » REE leaching efficiency obtained a maximum value of approximately 43 percent. Increasing the leaching time or liquid/solid ratio increased the leaching efficiency. The leaching efficiencies of P 2O 5, U and F consistently increased with sulfuric acid concentration, temperature, leaching time and liquid/solid ratio within the testing ranges. A fine-grain gypsum concentrate, sized smaller than 40 μm, was separated from leached phosphogypsum through elutriation, in which the P 2O 5, U and F content levels were reduced by 99, 70 and 83 percent, respectively, from their content levels in fresh phosphogypsum.« less

Rare earths recovery and gypsum upgrade from Florida phosphogypsum

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

Liang, Haijun; Zhang, Patrick; Jin, Zhen

Phosphogypsum is a byproduct created during the production of industrial wet-process phosphoric acid. This study focused on recovering rare earth elements (REEs) from a Florida phosphogypsum sample and investigated the effects of removing detrimental impurities such as phosphorus pentoxide (P 2O 5), uranium (U) and fluorine (F) during the leaching process. Experimental results indicated that REE leaching efficiency increased rapidly, reached a maximum and then began to decrease with sulfuric acid concentrations ranging from 0 to 10 percent and temperatures ranging from 20 to 70 °C. At a sulfuric acid concentration of 5 percent and leaching temperature of 50 °C,more » REE leaching efficiency obtained a maximum value of approximately 43 percent. Increasing the leaching time or liquid/solid ratio increased the leaching efficiency. The leaching efficiencies of P 2O 5, U and F consistently increased with sulfuric acid concentration, temperature, leaching time and liquid/solid ratio within the testing ranges. A fine-grain gypsum concentrate, sized smaller than 40 μm, was separated from leached phosphogypsum through elutriation, in which the P 2O 5, U and F content levels were reduced by 99, 70 and 83 percent, respectively, from their content levels in fresh phosphogypsum.« less

Development of an accelerated leaching method for incineration bottom ash correlated to toxicity characteristic leaching protocol.

PubMed

Lin, Shengxuan; Zhou, Xuedong; Ge, Liya; Ng, Sum Huan; Zhou, Xiaodong; Chang, Victor Wei-Chung

2016-10-01

Heavy metals and some metalloids are the most significant inorganic contaminants specified in toxicity characteristic leaching procedure (TCLP) in determining the safety of landfills or further utilization. As a consequence, a great deal of efforts had been made on the development of miniaturized analytical devices, such as Microchip Electrophoresis (ME) and μTAS for on-site testing of heavy metals and metalloids to prevent spreading of those pollutants or decrease the reutilization period of waste materials such as incineration bottom ash. However, the bottleneck lied in the long and tedious conventional TCLP that requires 18 h of leaching. Without accelerating the TCLP process, the on-site testing of the waste material leachates was impossible. In this study, therefore, a new accelerated leaching method (ALM) combining ultrasonic assisted leaching with tumbling was developed to reduce the total leaching time from 18 h to 30 min. After leaching, the concentrations of heavy metals and metalloids were determined with ICP-MS or ICP-optical emission spectroscopy. No statistical significance between ALM and TCLP was observed for most heavy metals (i.e., cobalt, manganese, mercury, molybdenum, nickel, silver, strontium, and tin) and metalloids (i.e., arsenic and selenium). For the heavy metals with statistical significance, correlation factors derived between ALM and TCLP were 0.56, 0.20, 0.037, and 0.019 for barium, cadmium, chromium, and lead, respectively. Combined with appropriate analytical techniques (e.g., ME), the ALM can be applied to rapidly prepare the incineration bottom ash samples as well as other environmental samples for on-site determination of heavy metals and metalloids. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Leaching characteristics of toxic constituents from coal fly ash mixed soils under the influence of pH.

PubMed

Komonweeraket, Kanokwan; Cetin, Bora; Benson, Craig H; Aydilek, Ahmet H; Edil, Tuncer B

2015-04-01

Leaching behaviors of Arsenic (As), Barium (Ba), Calcium (Ca), Cadmium (Cd), Magnesium (Mg), Selenium (Se), and Strontium (Sr) from soil alone, coal fly ash alone, and soil-coal fly ash mixtures, were studied at a pH range of 2-14 via pH-dependent leaching tests. Seven different types of soils and coal fly ashes were tested. Results of this study indicated that Ca, Cd, Mg, and Sr showed cationic leaching pattern while As and Se generally follows an oxyanionic leaching pattern. On the other hand, leaching of Ba presented amphoteric-like leaching pattern but less pH-dependent. In spite of different types and composition of soil and coal fly ash investigated, the study reveals the similarity in leaching behavior as a function of pH for a given element from soil, coal fly ash, and soil-coal fly ash mixtures. The similarity is most likely due to similar controlling mechanisms (e.g., solubility, sorption, and solid-solution formation) and similar controlling factors (e.g., leachate pH and redox conditions). This offers the opportunity to transfer knowledge of coal fly ash that has been extensively characterized and studied to soil stabilized with coal fly ash. It is speculated that unburned carbon in off-specification coal fly ashes may provide sorption sites for Cd resulting in a reduction in concentration of these elements in leachate from soil-coal fly ash mixture. Class C fly ash provides sufficient CaO to initiate the pozzolanic reaction yielding hydrated cement products that oxyanions, including As and Se, can be incorporated into. Copyright © 2014 Elsevier Ltd. All rights reserved.

Reflective and refractive objects for mixed reality.

PubMed

Knecht, Martin; Traxler, Christoph; Winklhofer, Christoph; Wimmer, Michael

2013-04-01

In this paper, we present a novel rendering method which integrates reflective or refractive objects into a differential instant radiosity (DIR) framework usable for mixed-reality (MR) applications. This kind of objects are very special from the light interaction point of view, as they reflect and refract incident rays. Therefore they may cause high-frequency lighting effects known as caustics. Using instant-radiosity (IR) methods to approximate these high-frequency lighting effects would require a large amount of virtual point lights (VPLs) and is therefore not desirable due to real-time constraints. Instead, our approach combines differential instant radiosity with three other methods. One method handles more accurate reflections compared to simple cubemaps by using impostors. Another method is able to calculate two refractions in real-time, and the third method uses small quads to create caustic effects. Our proposed method replaces parts in light paths that belong to reflective or refractive objects using these three methods and thus tightly integrates into DIR. In contrast to previous methods which introduce reflective or refractive objects into MR scenarios, our method produces caustics that also emit additional indirect light. The method runs at real-time frame rates, and the results show that reflective and refractive objects with caustics improve the overall impression for MR scenarios.

Wavefronts, actions and caustics determined by the probability density of an Airy beam

NASA Astrophysics Data System (ADS)

Espíndola-Ramos, Ernesto; Silva-Ortigoza, Gilberto; Sosa-Sánchez, Citlalli Teresa; Julián-Macías, Israel; de Jesús Cabrera-Rosas, Omar; Ortega-Vidals, Paula; Alejandro Juárez-Reyes, Salvador; González-Juárez, Adriana; Silva-Ortigoza, Ramón

2018-07-01

The main contribution of the present work is to use the probability density of an Airy beam to identify its maxima with the family of caustics associated with the wavefronts determined by the level curves of a one-parameter family of solutions to the Hamilton–Jacobi equation with a given potential. To this end, we give a classical mechanics characterization of a solution of the one-dimensional Schrödinger equation in free space determined by a complete integral of the Hamilton–Jacobi and Laplace equations in free space. That is, with this type of solution, we associate a two-parameter family of wavefronts in the spacetime, which are the level curves of a one-parameter family of solutions to the Hamilton–Jacobi equation with a determined potential, and a one-parameter family of caustics. The general results are applied to an Airy beam to show that the maxima of its probability density provide a discrete set of: caustics, wavefronts and potentials. The results presented here are a natural generalization of those obtained by Berry and Balazs in 1979 for an Airy beam. Finally, we remark that, in a natural manner, each maxima of the probability density of an Airy beam determines a Hamiltonian system.

An unconventional method for the recovery of caustic soda from spent Al-rich pickling solutions.

PubMed

Aprea, Paolo; de Gennaro, Bruno; Colella, Carmine

2011-07-01

This work presents an unconventional procedure for the recovery of spent Al-rich caustic soda solutions from the pickling of dies for the production of aluminium extrusions. Caustic soda was regenerated at roughly 70%, by precipitating aluminate, after addition of a silica source, in the form of zeolite A, a microporous material that is widely used in many technological sectors. It was shown that the process is reliable and can be repeated for several cycles, provided the concentration of the caustic soda solution is suitably restored. The by-product obtained, zeolite A, proved to be a high-grade material with performance as a cation exchanger and physical sorbent that is certainly comparable to that reported in literature (e.g., cation exchange capacity equal to 5.14 meq g(-1) vs. 5.48 meq g(-1) and water vapour adsorption capacity of 26.5% vs. 27.6% at 16 torr and 298 K). The economics of the process, although not examined yet, would appear generally favourable, considering that zeolite A is a valuable by-product which widely covers the costs for the recovery of the spent solutions. There are, therefore, significant prospects for the use of zeolite A, particularly as a builder in detergent formulation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Mobility of as, Cu, Cr, and Zn from tailings covered with sealing materials using alkaline industrial residues: a comparison between two leaching methods.

PubMed

Jia, Yu; Maurice, Christian; Öhlander, Björn

2016-01-01

Different alkaline residue materials (fly ash, green liquor dregs, and lime mud) generated from the pulp and paper industry as sealing materials were evaluated to cover aged mine waste tailings (<1% sulfur content, primarily pyrite). The mobility of four selected trace elements (Cr, Cu, Zn, and As) was compared based on batch and column leaching studies to assess the effectiveness of these alkaline materials as sealing agents. Based on the leaching results, Cr, Cu, and Zn were immobilized by the alkaline amendments. In the amended tailings in the batch system only As dramatically exceeded the limit values at L/S 10 L/kg. The leaching results showed similar patterns to the batch results, though leached Cr, Cu, and Zn showed higher levels in the column tests than in the batch tests. However, when the columns were compared with the batches, the trend for Cu was opposite for the unamended tailings. By contrast, both batch and column results showed that the amendment caused mobilization of As compared with the unamended tailings in the ash-amended tailings. The amount of As released was greatest in the ash column and decreased from the dregs to the lime columns. The leaching of As at high levels can be a potential problem whenever alkaline materials (especially for fly ash) are used as sealing materials over tailings. The column test was considered by the authors to be a more informative method in remediation of the aged tailings with low sulfur content, since it mimics better actual situation in a field.

Treatment of Petroleum Sludge By Using Solidification/Stabilization (S/S) Method : Effect of Hydration Days to Heavy Metals Leaching and Strength

NASA Astrophysics Data System (ADS)

Murshid, N.; Kamil, N. A. F. M.; Kadir, A. A.

2018-04-01

Petroleum sludge is one of the major solid wastes generated in the petroleum industry. Generally, there are numbers of heavy metals in petroleum sludge and one treatment that is gaining prominence to treat a variety of mixed organic and inorganic waste is solidification/stabilization (S/S) method. The treatment protects human health and the environment by immobilizing contaminants within the treated material and prevents migration of the contaminants. In this study, solidification/stabilization (S/S) method has been used to treat the petroleum sludge. The comparison of hydration days, namely, 7th and 28th days in these cement-based waste materials were studied by using Synthetic Precipitate Leaching Procedure (SPLP). The results were compared to the United States Environmental Protection Agency (USEPA) standards. The results for leaching test concluded that less percentage OPC gave maximum concentration of heavy metals leaching due to deficient in Calcium Oxide (CaO), which is can caused weak solidification in the mixture. Physical and mechanical properties conducted such as compressive strength and density test. From the results, it shows addition up to of 30percentage PS give results which comply with minimum landfill dispose limit. The results shows correlation between strength and density are strong regression coefficient of 82.7%. In conclusion, S/S method can be alternative disposal method for PS in the same time complies with standard for minimum landfill disposal limit. The results for leaching test concluded the less OPC percentage gave maximum concentration of heavy metals leaching.

Two-way Valorization of Blast Furnace Slag: Synthesis of Precipitated Calcium Carbonate and Zeolitic Heavy Metal Adsorbent.

PubMed

Georgakopoulos, Evangelos; Santos, Rafael M; Chiang, Yi Wai; Manovic, Vasilije

2017-02-21

The aim of this work is to present a zero-waste process for storing CO2 in a stable and benign mineral form while producing zeolitic minerals with sufficient heavy metal adsorption capacity. To this end, blast furnace slag, a residue from iron-making, is utilized as the starting material. Calcium is selectively extracted from the slag by leaching with acetic acid (2 M CH3COOH) as the extraction agent. The filtered leachate is subsequently physico-chemically purified and then carbonated to form precipitated calcium carbonate (PCC) of high purity (<2 wt% non-calcium impurities, according to ICP-MS analysis). Sodium hydroxide is added to neutralize the regenerated acetate. The morphological properties of the resulting calcitic PCC are tuned for its potential application as a filler in papermaking. In parallel, the residual solids from the extraction stage are subjected to hydrothermal conversion in a caustic solution (2 M NaOH) that leads to the predominant formation of a particular zeolitic mineral phase (detected by XRD), namely analcime (NaAlSi2O6∙H2O). Based on its ability to adsorb Ni 2+ , as reported from batch adsorption experiments and ICP-OES analysis, this product can potentially be used in wastewater treatment or for environmental remediation applications.

Two-way Valorization of Blast Furnace Slag: Synthesis of Precipitated Calcium Carbonate and Zeolitic Heavy Metal Adsorbent

PubMed Central

Georgakopoulos, Evangelos; Santos, Rafael M.; Chiang, Yi Wai; Manovic, Vasilije

2017-01-01

The aim of this work is to present a zero-waste process for storing CO2 in a stable and benign mineral form while producing zeolitic minerals with sufficient heavy metal adsorption capacity. To this end, blast furnace slag, a residue from iron-making, is utilized as the starting material. Calcium is selectively extracted from the slag by leaching with acetic acid (2 M CH3COOH) as the extraction agent. The filtered leachate is subsequently physico-chemically purified and then carbonated to form precipitated calcium carbonate (PCC) of high purity (<2 wt% non-calcium impurities, according to ICP-MS analysis). Sodium hydroxide is added to neutralize the regenerated acetate. The morphological properties of the resulting calcitic PCC are tuned for its potential application as a filler in papermaking. In parallel, the residual solids from the extraction stage are subjected to hydrothermal conversion in a caustic solution (2 M NaOH) that leads to the predominant formation of a particular zeolitic mineral phase (detected by XRD), namely analcime (NaAlSi2O6∙H2O). Based on its ability to adsorb Ni2+, as reported from batch adsorption experiments and ICP-OES analysis, this product can potentially be used in wastewater treatment or for environmental remediation applications. PMID:28287605

Lignor process for acidic rock drainage treatment.

PubMed

Zhuang, J M; Walsh, T

2004-09-01

The process using lignosulfonates for acidic rock drainage (ARD) treatment is referred to as the Lignor process. Lignosulfonates are waste by-products produced in the sulfite pulping process. The present study has shown lignosulfonates are able to protect lime from developing an external surface coating, and hence to favor its dissociation. Further, the addition of lignosulfonates to ARD solutions increased the dotting and settling rate of the formed sludge. The capability of lignosulfonates to form stable metal-lignin complexes makes them very useful in retaining metal ions and thus improving the long-term stability of the sludge against leaching. The Lignor process involves metal sorption with lignosulfonates, ARD neutralization by lime to about pH 7, pH adjustment with caustic soda to 9.4 - 9.6, air oxidation to lower the pH to a desired level, and addition of a minimum amount of FeCl3 for further removal of dissolved metals. The Lignor process removes all concerned metals (especially Al and Mn) from the ARD of the Britannia Mine (located at Britannia Beach, British Columbia, Canada) to a level lower than the limits of the B.C. Regulations. Compared with the high-density sludge (HDS) process, the Lignor process has many advantages, such as considerable savings in lime consumption, greatly reduced sludge volume, and improved sludge stability.

Implementation Guidance for the Next Generation Leaching Tests

EPA Science Inventory

Poster provides an overview of the purpose and utility of this research, highlights of the research to support the Leaching Environmental Assessment Framework (LEAF), application and translation (including data management and analysis software), intended end users, and lessons le...

Understanding how brass ball valves passing certification testing can cause elevated lead in water when installed.

PubMed

Triantafyllidou, Simoni; Raetz, Meredith; Parks, Jeffrey; Edwards, Marc

2012-06-15

The lead leaching potential of new brass plumbing devices has come under scrutiny as a significant source of lead in drinking water (>300 μg/L) of new buildings around the world. Experiments were conducted using ball valves that were sold as certified and known to have caused problems in practice, in order to better understand how installed products could create such problems, even if they passed "leaching tests" such as National Sanitation Foundation (NSF) Standard 61 Section 8. Diffusion of lead from within the device into water when installed can increase lead leaching by orders of magnitude relative to results of NSF testing, which once only required exposure of very small volumes of water within the device. "Normalization" of the lead-in-water result tended to produce estimates of lead concentration that were much lower than actual lead measured at the tap. Finally, the presence of flux could also dramatically increase lead leaching, whereas high water velocity had relatively little effect. Copyright © 2012. Published by Elsevier Ltd.

The leaching of vanadium(V) in soil due to the presence of atmospheric carbon dioxide and ammonia.

PubMed

Mandiwana, Khakhathi L; Panichev, Nikolay

2009-10-30

The natural leaching of vanadium(V) with CO2 from soil-water in the presence of ammonia, a known precursor to atmospheric aerosols, has been tested by bubbling carbon dioxide through soil suspension with varying amount of ammonia. It was found that the leaching of V(V) is enhanced in the presence of ammonia. From the results of the investigation, it could be concluded that atmospheric CO2 in the presence of ammonia (the only atmospheric gas that increases the pH of soil-water) could naturally leach V(V) from soil. Furthermore, it was also shown that the presence of (NH4)2CO3 in soil could enhance the leaching of toxic V(V) species thereby making it bioavailable for both plants and animals.

Synopsis of research needs workshop: Development of leach tests for contaminated dredged material held in Baton Rouge, Louisiana on 23-24 June 1988. Final report

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

Not Available

1990-02-01

This report presents the findings of a research needs workshop on the development of leach tests for contaminated dredged material, held 23-24 June 1988 in Baton Rouge, LA. The workshop was hosted by the Louisiana Water Resources Research Institute and the US Army Engineer Waterways Experiment Station (WES). The workshop participants reviewed results of research on test procedures developed by the WES and provided eight recommendations for directing future research in this area. Workshop panelists were of the opinion that research conducted to date was good and generally validated the basic technical approaches suggested by the 1984 Corps leachate qualitymore » working group. However, the consensus was that much research remains to be done before a leach test (s) will be available for routine use.« less

The combined effects of urea application and simulated acid rain on soil acidification and microbial community structure.

PubMed

Liu, Xingmei; Zhou, Jian; Li, Wanlu; Xu, Jianming; Brookes, Philip C

2014-05-01

Our aim was to test the effects of simulated acid rain (SAR) at different pHs, when applied to fertilized and unfertilized soils, on the leaching of soil cations (K, Ca, Mg, Na) and Al. Their effects on soil pH, exchangeable H(+) and Al(3+) and microbial community structure were also determined. A Paleudalfs soil was incubated for 30 days, with and without an initial application of urea (200 mg N kg(-1)soil) as nitrogen (N) fertilizer. The soil was held in columns and leached with SAR at three pH levels. Six treatments were tested: SAR of pH 2.5, 4.0 and 5.6 leaching on unfertilized soil (T1, T2 and T3), and on soils fertilized with urea (T4, T5 and T6). Increasing acid inputs proportionally increased cation leaching in both unfertilized and fertilized soils. Urea application increased the initial Ca and Mg leaching, but had no effect on the total concentrations of Ca, Mg and K leached. There was no significant difference for the amount of Na leached between the different treatments. The SAR pH and urea application had significant effects on soil pH, exchangeable H(+) and Al(3+). Urea application, SAR treated with various pH, and the interactions between them all had significant impacts on total phospholipid fatty acids (PLFAs). The highest concentration of total PLFAs occurred in fertilized soils with SAR pH5.6 and the lowest in soils leached with the lowest SAR pH. Soils pretreated with urea then leached with SARs of pH 4.0 and 5.6 had larger total PLFA concentrations than soil without urea. Bacterial, fungal, actinomycete, Gram-negative and Gram-positive bacterial PLFAs had generally similar trends to total PLFAs.

Design and testing of an electromagnetic coupling

NASA Technical Reports Server (NTRS)

Anderson, William J.

1986-01-01

Hostile environments such as the hard vacuum of space, and exposure to water or caustic fluids have fostered the development of devices which allow mechanical rotary feed throughs with positive sealing without the use of conventional dynamic seals. One such device is an electromagnetic coupling which transfers motion across a hermetic seal by means of a rotating magnetic field. Static pull-out torque and dynamic heat build-up and pull-out torque tests of a synchronous reluctance homopolar coupling are reported herein. Coupling efficiencies are estimated for a range of speeds and torques.

How the origin of fresh household waste affects its ability to be biodegraded: an assessment using basic tools and its application to the city of Kara in Togo.

PubMed

Segbeaya, K N; Feuillade-Cathalifaud, G; Baba, G; Koledzi, E K; Pallier, V; Tchangbedji, G; Matejka, G

2012-12-01

Waste biodegradation has been largely investigated in the literature by using conventional tests like the BMP test and the respirometric test, whereas only few studies deal with the use of leaching tests in combination with biological activity measurements. Consequently, this study used an improved leaching test to evaluate the biodegradability of two deposits of fresh household waste from the city of Kara in Togo. The first deposit came from households in neighborhoods located in the outskirts of the city and the second consisted of fresh waste, mainly composed of business waste and household waste, collected in the urban center and aimed at being deposited in the landfill. A physicochemical characterization of the two deposits completed the leaching test. The biological activity was monitored by measuring O(2) consumption and CO(2) production. pH, DOC/OM, VFA/DOC ratios and the SUVA index was measured in the leaching juice to assess both the state of degradation of the waste in the deposits and the ability of the organic matter to be mobilized quickly and to be easily assimilated by microorganisms. The biodegradability of waste from the city of Kara correlated with their origin even though the physical characteristics of the two deposits studied differed greatly. Copyright © 2012 Elsevier Ltd. All rights reserved.

Leaching Behavior of Selected Trace and Toxic Metals in Coal Fly Ash Samples Collected from Two Thermal Power Plants, India.

PubMed

Sandeep, P; Sahu, S K; Kothai, P; Pandit, G G

2016-09-01

Studies on leaching behavior of metals associated with coal fly ash (FA) are of great concern because of possible contamination of the aquatic environment. In the present study, leaching behavior of metals (As, Se, Cr, Pb, V, Zn, etc.) in two different FA samples (FA1 and FA2) was investigated at various pH (2-12), temperatures of leachate solution and using TCLP. At pH 2, the highest leaching was observed for Fe (21.6 and 32.8 µg/g), whereas at pH 12, Arsenic was found to have the highest leaching (1.5 and 2.4 µg/g) in FA1 and FA2. Leachate solution temperature showed a positive effect on the metal's leachability. In TCLP, most of the metal's leachability was observed to be higher than that of batch leaching tests. The present study suggests that, leaching of As and Se from FA samples can moderately affect ground/surface water quality at the study locations.

Handbook of Thermal Insulation Applications.

DTIC Science & Technology

1983-01-01

today. Every $10 spent on conservation would save at least I barrel of oil - equivalent * to buying oil at $10 a barrel. In recent years, energy...there exists some point at which’more would be spent for an increment of insulation than could ever be saved by that increment. By adding the...TO ACIDS, CAUSTICS , AND SOLVENTS: The property of a material to resist decomposition by various acids, caustics and solvents to which it may be

Polymer Claw: Instant Underwater Adhesive

DTIC Science & Technology

2012-10-23

April to October. The biofilms included mostly algae with patches of barnacles. 3.1.1 Removal of Biofilm with Caustic Paste The caustic paste was...when the brush was rotated 360° while it was pressed downwards. Figure 3 shows that the thick algae biofilm was completely removed under these...413 TABLE OF CONTENTS 1 SUMMARY 1 2 PROIECT GOALS AND OBJECTIVES 3. 1 KEY ACCOMPLISHMENTS 3 3.1 BIOFILM REMOVAL 3 3.1.1 REMOVAL OF BIOFILM

First Responders Immersive Training Simulation Environment (FRITSE): Scenario Development and Support

DTIC Science & Technology

2014-07-30

consisted of three stages: a deliberate derailment of a train containing either methanol (flammable) or ammonia (caustic) cars at an overpass where...event would be the deliberate release of chemical agent from a van parked near the train derailment and the tertiary event would be a giant fertilizer ...political targets is highest. The derailment would cause a major leak of either caustic ( ammonia ) or highly flammable (methanol) material from derailed

A new approach on Brewer's spent grains treatment and potential use as lignocellulosic yeast cells carriers.

PubMed

Pires, Eduardo J; Ruiz, Héctor A; Teixeira, José A; Vicente, António A

2012-06-13

The major objective of this work is to improve the pretreatments of brewer's spent grains (BSG) aiming at their use as a source for lignocellulosic yeast carriers (LCYC) production. Therefore, several pretreatments of BSG have been designed aiming at obtaining various yeast carriers, differing on their physicochemical composition. Cellulose, hemicellulose, lignin, fat, protein, and ash content were determined for crude BSG and the LCYCs. The long chain fatty acids profile for the crude BSG was also analyzed. Chemical treatments successfully produced several different LCYC based on BSG. The highest cellulose content in LCYC was achieved upon application of caustic (NaOH) treatment during 40 min. Either caustic or combined acid-caustic treatments predominately generated hydrophobic, negatively charged LCYC. The feasibility of using BSG for LCYC production is strengthened by the fact that added-value byproduct can be extracted before the chemical treatments are applied.

Sodium to sodium carbonate conversion process

DOEpatents

Herrmann, Steven D.

1997-01-01

A method of converting radioactive alkali metal into a low level disposable solid waste material. The radioactive alkali metal is atomized and introduced into an aqueous caustic solution having caustic present in the range of from about 20 wt % to about 70 wt % to convert the radioactive alkali metal to a radioactive alkali metal hydroxide. The aqueous caustic containing radioactive alkali metal hydroxide and CO.sub.2 are introduced into a thin film evaporator with the CO.sub.2 present in an amount greater than required to convert the alkali metal hydroxide to a radioactive alkali metal carbonate, and thereafter the radioactive alkali metal carbonate is separated from the thin film evaporator as a dry powder. Hydroxide solutions containing toxic metal hydroxide including one or more metal ions of Sb, As, Ba, Be, Cd, Cr, Pb, Hg, Ni, Se, Ag and T1 can be converted into a low level non-hazardous waste using the thin film evaporator of the invention.

[Leaching Remediation of Copper and Lead Contaminated Lou Soil by Saponin Under Different Conditions].

PubMed

Deng, Hong-xia; Yang, Ya-li; Li, Zhen; Xu, Yan; Li, Rong-hua; Meng, Zhao-fu; Yang, Ya-ti

2015-04-01

In order to investigate the leaching remediation effect of the eco-friendly biosurfactant saponin for Cu and Pb in contaminated Lou soil, batch tests method was used to study the leaching effect of saponin solution on single Cu, Pb contaminated Lou soil and mixed Cu and Pb contaminated Lou soil under different conditions such as reaction time, mass concentration of saponin, pH, concentration of background electrolyte and leaching times. The results showed that the maximum leaching removal effect of Cu and Pb in contaminated Lou soil was achieved by complexation of the heavy metals with saponin micelle, when the mass concentration of saponin solution was 50 g x L(-1), pH was 5.0, the reaction time was 240 min, and there was no background electrolyte. In single and mixed contaminated Lou soil, the leaching percentages of Cu were 29.02% and 25.09% after a single leaching with 50 g x L(-1) saponin under optimal condition, while the single leaching percentages of Pb were 31.56% and 28.03%, respectively. The result indicated the removal efficiency of Pb was more significant than that of Cu. After 4 times of leaching, the cumulative leaching percentages of Cu reached 58.92% and 53.11%, while the cumulative leaching percentages of Pb reached 77.69% and 65.32% for single and mixed contaminated Lou soil, respectively. The fractionation results of heavy metals in soil before and after a single leaching showed that the contents of adsorbed and exchangeable Cu and Pb increased in the contaminated soil, while the carbonate-bound, organic bound and sulfide residual Cu and Pb in the contaminated Lou soil could be effectively removed by saponin.

Model-based coefficient method for calculation of N leaching from agricultural fields applied to small catchments and the effects of leaching reducing measures

NASA Astrophysics Data System (ADS)

Kyllmar, K.; Mårtensson, K.; Johnsson, H.

2005-03-01

A method to calculate N leaching from arable fields using model-calculated N leaching coefficients (NLCs) was developed. Using the process-based modelling system SOILNDB, leaching of N was simulated for four leaching regions in southern Sweden with 20-year climate series and a large number of randomised crop sequences based on regional agricultural statistics. To obtain N leaching coefficients, mean values of annual N leaching were calculated for each combination of main crop, following crop and fertilisation regime for each leaching region and soil type. The field-NLC method developed could be useful for following up water quality goals in e.g. small monitoring catchments, since it allows normal leaching from actual crop rotations and fertilisation to be determined regardless of the weather. The method was tested using field data from nine small intensively monitored agricultural catchments. The agreement between calculated field N leaching and measured N transport in catchment stream outlets, 19-47 and 8-38 kg ha -1 yr -1, respectively, was satisfactory in most catchments when contributions from land uses other than arable land and uncertainties in groundwater flows were considered. The possibility of calculating effects of crop combinations (crop and following crop) is of considerable value since changes in crop rotation constitute a large potential for reducing N leaching. When the effect of a number of potential measures to reduce N leaching (i.e. applying manure in spring instead of autumn; postponing ploughing-in of ley and green fallow in autumn; undersowing a catch crop in cereals and oilseeds; and increasing the area of catch crops by substituting winter cereals and winter oilseeds with corresponding spring crops) was calculated for the arable fields in the catchments using field-NLCs, N leaching was reduced by between 34 and 54% for the separate catchments when the best possible effect on the entire potential area was assumed.

Evaluating the cement stabilization of arsenic-bearing iron wastes from drinking water treatment.

PubMed

Clancy, Tara M; Snyder, Kathryn V; Reddy, Raghav; Lanzirotti, Antonio; Amrose, Susan E; Raskin, Lutgarde; Hayes, Kim F

2015-12-30

Cement stabilization of arsenic-bearing wastes is recommended to limit arsenic release from wastes following disposal. Such stabilization has been demonstrated to reduce the arsenic concentration in the Toxicity Characteristic Leaching Procedure (TCLP), which regulates landfill disposal of arsenic waste. However, few studies have evaluated leaching from actual wastes under conditions similar to ultimate disposal environments. In this study, land disposal in areas where flooding is likely was simulated to test arsenic release from cement stabilized arsenic-bearing iron oxide wastes. After 406 days submersed in chemically simulated rainwater, <0.4% of total arsenic was leached, which was comparable to the amount leached during the TCLP (<0.3%). Short-term (18 h) modified TCLP tests (pH 3-12) found that cement stabilization lowered arsenic leaching at high pH, but increased leaching at pH<4.2 compared to non-stabilized wastes. Presenting the first characterization of cement stabilized waste using μXRF, these results revealed the majority of arsenic in cement stabilized waste remained associated with iron. This distribution of arsenic differed from previous observations of calcium-arsenic solid phases when arsenic salts were stabilized with cement, illustrating that the initial waste form influences the stabilized form. Overall, cement stabilization is effective for arsenic-bearing wastes when acidic conditions can be avoided. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of preconditioning on silver leaching and bromide removal properties of silver-impregnated activated carbon (SIAC).

PubMed

Rajaeian, Babak; Allard, Sébastien; Joll, Cynthia; Heitz, Anna

2018-07-01

Silver impregnated activated carbon (SIAC) has been found to be effective in mitigating the formation of brominated-disinfection by products during drinking water treatment. However, there are still uncertainties regarding its silver leaching properties, and strategies for the prevention of silver leaching have remained elusive. This study focused on the evaluation of one type of commercially available SIAC for its ability to remove bromide while minimising silver leaching from the material. Both synthetic and real water matrices were tested. Depending on solution pH, it was found that changing the surface charge properties of SIAC, as measured by the point of zero charge pH, can result in additional bromide removal while minimising the extent of silver leaching. To better understand the mechanism of silver leaching from the SIAC, eight preconditioning environments, i.e. variable pH and ionic strength were tested for a fixed amount of SIAC and two preconditioning environments were selected for a more detailed investigation. Experiments carried out in synthetic water showed that preconditioning at pH 10.4 did not deteriorate the capacity of SIAC to remove bromide, but significantly decreased the release of silver in the form of ionic silver (Ag + ), silver bromide (AgBr) and silver chloride (AgCl) from 40% for the pristine to 3% for the treated SIAC. This was confirmed using a groundwater sample. These results suggest that preconditioned SIAC has the potential to be an effective method for bromide removal with minimised silver leaching in a long-term field application for drinking water production. Copyright © 2018 Elsevier Ltd. All rights reserved.

Release of heavy metals during long-term land application of sewage sludge compost: Percolation leaching tests with repeated additions of compost.

PubMed

Fang, Wen; Delapp, Rossane C; Kosson, David S; van der Sloot, Hans A; Liu, Jianguo

2017-02-01

Leaching assessment procedures have been used to determine the leachability of heavy metals as input for evaluating the risk from sewage sludge compost land application. However, relatively little attention has been paid to understanding leaching from soils with repeated application of sewage sludge compost with elevated levels of heavy metals. In this paper, leaching assessment is extended to evaluate the potential leaching of heavy metals during repetitive application of composted sewage sludge to soils. Four cycling of compost additions and percolation leaching were conducted to investigate how leaching behavior of heavy metals changed with repeated additions of compost. Results showed that repetitive additions of compost to soil significantly increased the content of organic matter, which favored the formation of reducing condition due to improved microbial activities and oxygen consumption. Establishment of reducing conditions can enhance the leaching concentrations of As by approximately 1 order of magnitude, especially for the soil rich in organic matter. For Cd, Cr, Cu, and Pb, repeated additions of compost will cause accumulation in total contents but not enhancement in leaching concentrations. The infiltration following compost additions will leach out the mobile fraction and the residual fraction might not release in the next cycling of compost addition and infiltration. The cumulative release of Cd, Cr, Cu, and Pb accounted for less than 5% of the total contents during four times of compost applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Kinetics of steel slag leaching: Batch tests and modeling

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

De Windt, Laurent, E-mail: laurent.dewindt@mines-paristech.fr; Chaurand, Perrine; Rose, Jerome

2011-02-15

Reusing steel slag as an aggregate for road construction requires to characterize the leaching kinetics and metal releases. In this study, basic oxygen furnace (BOF) steel slag were subjected to batch leaching tests at liquid to solid ratios (L/S) of 10 and 100 over 30 days; the leachate chemistry being regularly sampled in time. A geochemical model of the steel slag is developed and validated from experimental data, particularly the evolution with leaching of mineralogical composition of the slag and trace element speciation. Kinetics is necessary for modeling the primary phase leaching, whereas a simple thermodynamic equilibrium approach can bemore » used for secondary phase precipitation. The proposed model simulates the kinetically-controlled dissolution (hydrolysis) of primary phases, the precipitation of secondary phases (C-S-H, hydroxide and spinel), the pH and redox conditions, and the progressive release of major elements as well as the metals Cr and V. Modeling indicates that the dilution effect of the L/S ratio is often coupled to solubility-controlled processes, which are sensitive to both the pH and the redox potential. A sensitivity analysis of kinetic uncertainties on the modeling of element releases is performed.« less

Leaching behaviour of bottom ash from RDF high-temperature gasification plants

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

Gori, M., E-mail: manuela.gori@dicea.unifi.it; Pifferi, L.; Sirini, P.

2011-07-15

This study investigated the physical properties, the chemical composition and the leaching behaviour of two bottom ash (BA) samples from two different refuse derived fuel high-temperature gasification plants, as a function of particle size. The X-ray diffraction patterns showed that the materials contained large amounts of glass. This aspect was also confirmed by the results of availability and ANC leaching tests. Chemical composition indicated that Fe, Mn, Cu and Cr were the most abundant metals, with a slight enrichment in the finest fractions. Suitability of samples for inert waste landfilling and reuse was evaluated through the leaching test EN 12457-2.more » In one sample the concentration of all metals was below the limit set by law, while limits were exceeded for Cu, Cr and Ni in the other sample, where the finest fraction showed to give the main contribution to leaching of Cu and Ni. Preliminary results of physical and geotechnical characterisation indicated the suitability of vitrified BA for reuse in the field of civil engineering. The possible application of a size separation pre-treatment in order to improve the chemical characteristics of the materials was also discussed.« less

Pitting Behavior of L415 Pipeline Steel in Simulated Leaching Liquid Environment

NASA Astrophysics Data System (ADS)

Wan, H. X.; Yang, X. J.; Liu, Z. Y.; Song, D. D.; Du, C. W.; Li, X. G.

2017-02-01

The corrosion behavior and laws of the west-east gas pressure pipeline of L415 steel were studied in simulated leaching liquid. The failure of the L415 steel during the pressure testing process was investigated using electrochemical polarization, electrochemical impedance spectroscopy, and immersion test. The corrosion rate of the L415 steel increased with ion concentration in the leaching liquid. This rate reached about 0.8 mm a-1 and belonged to the severe corrosion grade. Pitting corrosion was observed in various simulated solutions with different aggressive species concentrations. The original ion concentration in the leaching liquid (1×) is the key factor influencing pitting initiation and development. Pitting showed easy nucleation, and its growth rate was relatively slow, in the basic simulating solution of the leach liquid (i.e., the ion content is compactable to the real condition in the rust on the inner steel pipe surface). Pitting was also highly sensitive and easily grew in the solution with doubled ion concentration in the basic simulating solution (2×). A uniform corrosion, instead of pitting, mainly occurred when the ion concentration was up to 10× of the basic solution.

Residual organic matter and microbial respiration in bottom ash: Effects on metal leaching and eco-toxicity.

PubMed

Ilyas, A; Persson, K M; Persson, M

2015-09-01

A common assumption regarding the residual organic matter, in bottom ash, is that it does not represent a significant pool of organic carbon and, beyond metal-ion complexation process, it is of little consequence to evolution of ash/leachate chemistry. This article evaluates the effect of residual organic matter and associated microbial respiratory processes on leaching of toxic metals (i.e. arsenic, copper, chromium, molybdenum, nickel, lead, antimony and zinc), eco-toxicity of ash leachates. Microbial respiration was quantified with help of a respirometric test equipment OXITOP control system. The effect of microbial respiration on metal/residual organic matter leaching and eco-toxicity was quantified with the help of batch leaching tests and an eco-toxicity assay - Daphnia magna. In general, the microbial respiration process decreased the leachate pH and eco-toxicity, indicating modification of bioavailability of metal species. Furthermore, the leaching of critical metals, such as copper and chromium, decreased after the respiration in both ash types (fresh and weathered). It was concluded that microbial respiration, if harnessed properly, could enhance the stability of fresh bottom ash and may promote its reuse. © The Author(s) 2015.

PRELIMINARY RESULTS OF A PESTICIDE LEACHING STUDY AT PLAINS, GA

EPA Science Inventory

A comprehensive field data base is being developed for testing various chemical transport models of pesticide leaching. hree Federal agencies (U.S. Environmental Protection Agency, U.S. Department of Agriculture, and U.S. Geological Survey) and the University of Georgia's Agricul...

Construction and demolition waste: Comparison of standard up-flow column and down-flow lysimeter leaching tests.

PubMed

Butera, Stefania; Hyks, Jiri; Christensen, Thomas H; Astrup, Thomas F

2015-09-01

Five samples of construction and demolition waste (C&DW) were investigated in order to quantify leaching of inorganic elements under percolation conditions according to two different experimental setups: standardised up-flow saturated columns (<4mm particle size) and unsaturated, intermittent down-flow lysimeters (<40mm particle size). While standardised column tests are meant primarily to provide basic information on characteristic leaching properties and mechanisms and not to reproduce field conditions, the lysimeters were intended to mimic the actual leaching conditions when C&DW is used in unbound geotechnical layers. In practice, results from standardised percolation tests are often interpreted as estimations of actual release from solid materials in percolation scenarios. In general, the two tests yielded fairly similar results in terms of cumulative release at liquid-to-solid ratio (L/S) 10l·kgTS; however, significant differences were observed for P, Pb, Ba, Mg and Zn. Further differences emerged in terms of concentration in the early eluates (L/S<5l·kg(-1)TS) for Al, As, Ba, Cd, Cu, DOC, Mg, Mn, Ni, P, Pb, Sb, Se, Si, Zn. Observed differences between tests are likely to be due to differences in pH related to crushing and exposure of fresh particle surfaces, as well as in equilibrium conditions. In the case of C&DW, the standardised column tests, which are more practical, are considered to acceptably describe cumulative releases at L/S 10l·kg(-1)TS in percolation scenarios. However, when the focus is on estimation of initial concentrations for (for example) risk assessment, data from standardised column tests may not be fully applicable, and data from lysimeters may be used for validation purposes. Se, Cr and, to a lesser extent, SO4 and Sb were leaching from C&DW in critical amounts compared with existing limit values. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Ingestion of caustic substances: An analysis of the safety and benefit of a less aggressive protocol].

PubMed

Ripoll Trujillo, Noelia; Martínez Sánchez, Lidia; Habimana Jordana, Anna; Trenchs Sainz de La Maza, Victoria; Vila Miravet, Víctor; Luaces Cubells, Carles

2018-04-14

The ingestion of a caustic agent is the most common cause of admission after being in contact with a domestic product. A group of patients could be considered low risk and not require aggressive procedures such a corticosteroid administration and endoscopy, especially in the paediatric population. To evaluate the safety and benefit of a less aggressive protocol for patients defined as low risk. An analytical-observational study conducted on patients who consulted for caustic ingestion between January 2011 and December 2015. Two periods were differentiated according to the current protocol. Period-1: usual protocol (which included admission and parenteral corticosteroid and antibiotic administration) and Period-2: less aggressive protocol for the low risk patients (oral intake test after 6hours and discharged if they remained asymptomatic). Low risk patients were considered as those who met the following criteria: unintentional intake, absence of symptoms and oral lesions. In the rest of the patients the usual protocol was performed. Re-admission with a diagnosis of digestive lesions was considered as a complication. Forty-eight patients were included in period 1, and 35 in period 2. In period 2, thirteen patients met low risk criteria. The adherence to the less aggressive protocol was 100%. None of the low risk patients required admission or endoscopy after discharge. In period 1 the adherence to the usual protocol was 60.4%. Six patients would have benefited from the application of the less aggressive protocol. Adopting a more conservative attitude in low risk patients is safe. These patients benefit from clinical observation, without performing more aggressive measures with their possible iatrogenic adverse effects. Copyright © 2018. Publicado por Elsevier España, S.L.U.

Leaching assessments of toxic metals in waste plasma display panel glass.

PubMed

Chen, Mengjun; Jiang, Pengfei; Chen, Haiyan; Ogunseitan, Oladele A; Li, Yungui

2015-06-01

The plasma display panel (PDP) is rapidly becoming obsolete, contributing in large amounts to the electronic waste stream. In order to assess the potential for environmental pollution due to hazardous metals leached from PDP glass, standardized leaching procedures, chemical speciation assessments, and bioavailability tests were conducted. According to the Toxicity Characteristic Leaching Procedure (TCLP), arsenic in back glass was present at 4.46 ± 0.22 mg/L, close to its regulation limit of 5 mg/L. Zn is not available in the TCLP, but its TCLP leaching concentration in back glass is 102.96 ± 5.34 mg/L. This is because more than 90% of Zn is in the soluble and exchangeable and carbonate fraction. We did not detect significant levels of Ag, Ba, or Cu in the TCLP leachate, and the main fraction of Ag and Ba is residual, more than 95%, while the fraction distribution of Cu changes SEP by SEP. Ethylenediamine tetraacetic acid (EDTA)- and diethylenetriamine pentaacetic acid (DTPA)-extractable Ag, As, Ba, Cu, Zn, and Ni indicate a lower biohazards potential. These results show that, according to the EPA regulations, PDP glass may not be classified as hazardous waste because none of the metals exceeded their thresholds in PDP leachate. However, the concentrations of As and Zn should be lowered in the manufacturing process and finished product to avoid potential pollution problems. The plasma display panel is rapidly becoming obsolete because of the liquid crystal display. In this study, the leachability of heavy metals contained in the waste plasma display panel glass was first examined by standardized leaching tests, typical chemical speciation assessments, and bioavailability tests, providing fundamental data for waste PDP glass recovery, recycling, and reuse.

The Use of EMS Personnel as Intelligence Sensors: Critical Issues and Recommended Practices

DTIC Science & Technology

2007-09-01

caustic chemical with intent to injure, child abuse or endangerment , abuse of spouse, lewd acts with a child , and elder abuse.) The content of the...technicians and paramedics must report child abuse and dependent elder abuse.46 However, within the performance of their pre-hospital duties, this... child abuse, or public health surveillance, investigation or intervention.48 This preemption test creates a floor or minimum standard for protection

Performance assessment of nitrate leaching models for highly vulnerable soils used in low-input farming based on lysimeter data.

PubMed

Groenendijk, Piet; Heinen, Marius; Klammler, Gernot; Fank, Johann; Kupfersberger, Hans; Pisinaras, Vassilios; Gemitzi, Alexandra; Peña-Haro, Salvador; García-Prats, Alberto; Pulido-Velazquez, Manuel; Perego, Alessia; Acutis, Marco; Trevisan, Marco

2014-11-15

The agricultural sector faces the challenge of ensuring food security without an excessive burden on the environment. Simulation models provide excellent instruments for researchers to gain more insight into relevant processes and best agricultural practices and provide tools for planners for decision making support. The extent to which models are capable of reliable extrapolation and prediction is important for exploring new farming systems or assessing the impacts of future land and climate changes. A performance assessment was conducted by testing six detailed state-of-the-art models for simulation of nitrate leaching (ARMOSA, COUPMODEL, DAISY, EPIC, SIMWASER/STOTRASIM, SWAP/ANIMO) for lysimeter data of the Wagna experimental field station in Eastern Austria, where the soil is highly vulnerable to nitrate leaching. Three consecutive phases were distinguished to gain insight in the predictive power of the models: 1) a blind test for 2005-2008 in which only soil hydraulic characteristics, meteorological data and information about the agricultural management were accessible; 2) a calibration for the same period in which essential information on field observations was additionally available to the modellers; and 3) a validation for 2009-2011 with the corresponding type of data available as for the blind test. A set of statistical metrics (mean absolute error, root mean squared error, index of agreement, model efficiency, root relative squared error, Pearson's linear correlation coefficient) was applied for testing the results and comparing the models. None of the models performed good for all of the statistical metrics. Models designed for nitrate leaching in high-input farming systems had difficulties in accurately predicting leaching in low-input farming systems that are strongly influenced by the retention of nitrogen in catch crops and nitrogen fixation by legumes. An accurate calibration does not guarantee a good predictive power of the model. Nevertheless all models were able to identify years and crops with high- and low-leaching rates. Copyright © 2014 Elsevier B.V. All rights reserved.

Proceedings of the Technology Transfer Seminar/Workshop on the Application of Pollution Abatement Technology to Local Governments

DTIC Science & Technology

1975-05-01

civil agencies through interage..:y agreements. One of the Navy field activities, the Naval Ammunition Depot at Crane , Indiana, has developed rather...chemical mixing compartment and chem- ical dosing tank assures adequate contact time. Solids and organics are hydrolyzed by the caustic , while the...The high caustic level of the treated waste water resulted in corrosion to various points in the system. Pumps required extensive weekly maintenance

Analysis of Deep Seafloor Arrivals Observed on NPAL04

DTIC Science & Technology

2012-12-03

transmission station to the scattering point (black line) to compute the time spent on the PE-predicted path to the scattering point. This time would...arrives at the OBSs at times corresponding to caustics of the PE predicted time fronts, there are large amplitude, late arrivals that occur between... caustics and even after the PE predicted coda. Similar analysis was done for T500 to T2300 with similar results and is discussed in Section 4 of

The Effects of Internal Tides on Acoustic Propagation in the Philippine Sea

DTIC Science & Technology

2013-09-01

understanding during the long days spent away from home while working on this thesis xvi THIS PAGE INTENTIONALLY LEFT BLANK 1 I. INTRODUCTION...sweeping by a vertical set of receivers at a fixed range. Each wavefront branch is seen as the line between caustics (acoustic focusing points where...the ray folds), and is composed of eigenrays with the same ID. The caustics farthest to the left of the timefront plot represent the rays with large

Hazardous Waste Minimization Initiation Decision Report. Volume 1

DTIC Science & Technology

1988-06-01

different treatment and disposal practices for spent caustic materials. In some cases, the material is placed in drums and sent to DRMO for disposal or to a...often available. As at some Navy facilities, waste caustic may be neutralized with spent acid at the process line with the effluent sent to the IWTP...3-111 PART II - Spent Battery Electrolyte .... 3-112 PART III- Battery Acid Sludges ........ 3-113 3.13.3 Disposal of Wastes from Battery Repair and

Commandant’s International Technical Series. Volume 9. International Regulations on the Prevention of Pollution from Ships Carrying Hazardous Chemicals in Bulk.

DTIC Science & Technology

1985-12-01

Styrene monomer 2055 B Sulphuric acid 1830 C " Sulphuric acid, spent 1832 C - Sulphurous acid 1633 (C) Sunflover oil D...anhydrides (e.g. formic, acetic); .3 halogenated carboxylic acids (e.g. chloracetic); .4 sulpnonic acids (e.g. benzene sulphonic); .5 caustic alkalis...acetic); (iii) halogenated carboxylic acids (e.g. cbloracetic); (iv) sulphonic acids (e.g. benzene sulphonic);II (v) caustic alkalis (e.g. sodium

Left colonic graft in esophageal reconstruction for caustic stricture: mortality and morbidity.

PubMed

Boukerrouche, A

2013-01-01

The adequacy of the blood supply to the left colon graft and its ability to transport food effectively from pharynx to stomach made it an esophageal substitute of choice, particularly in esophageal caustic stricture. From 1999 to 2009, 60 patients underwent colon interposition for esophageal caustic stricture (n= 57) and cancer (n= 3). An isoperistaltic colonic graft based on the left colonic artery could be used in all of these patients. The substernal route was used exclusively, and upper thoracic inlet was opened when necessary. The isoperistaltic left colonic graft interposed by substernal route represents the surgical procedure of choice in all operations performed for esophageal substitution during the study period. The operative mortality rate was 3.3%. A cervical fistula occurred in 10 patients (16.6%) and cervical anastomotic stricture in five patients (8.3%). Dilation was required in all the stricture of the esophageal colonic anastomosis with good response. The isoperistaltic left colic transplant supplied by the left colic pedicle is an excellent long-term replacement organ for the esophageal caustic stenosis. When performed by experienced surgeons, the left isoperistaltic esophagocoloplasty is a satisfactory surgical method for esophageal reconstruction with acceptable early morbidity and good long-term functional results. © 2012 Copyright the Authors. Journal compilation © 2012, Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus.

Chromium behavior during thermal treatment of MSW fly ash.

PubMed

Kirk, Donald W; Chan, Chris C Y; Marsh, Hilary

2002-02-14

Energy-from-waste incineration has been promoted as an environmentally responsible method for handling non-recyclable waste from households. Despite the benefits of energy production, elimination of organic residues and reduction of volume of waste to be landfilled, there is concern about fly ash disposal. Fly ash from an incinerator contains toxic species such as Pb, Zn, Cd and Cr which may leach into soil and ground water if landfilled. Thermal treatment of the fly ash from municipal solid waste has been tested and proposed as a treatment option for removal of metal species such as Pb, Cd and Zn, via thermal re-volatilization. However, Cr is an element that remains in the residue of the heat treated fly ash and appears to become more soluble. This Cr solubilization is of concern if it exceeds the regulatory limit for hazardous waste. Hence, this unexpected behavior of Cr was investigated. The initial work involved microscopic characterization of Cr in untreated and thermally-treated MSW fly ash. This was followed by determining leaching characteristics using standard protocol leaching tests and characterization leaching methods (sequential extraction). Finally, a mechanism explaining the increased solubilization was proposed and tested by reactions of synthetic chemicals.

Analysis and interpretation of the leaching behaviour of waste thermal treatment bottom ash by batch and column tests.

PubMed

Di Gianfilippo, Martina; Costa, Giulia; Verginelli, Iason; Gavasci, Renato; Lombardi, Francesco

2016-10-01

This paper investigates the leaching behaviour of specific types of waste thermal treatment bottom ash (BA) as a function of both pH and the liquid-to-solid ratio (L/S). Specifically, column percolation tests and different types of batch tests (including pH-dependence) were applied to BA produced by hospital waste incineration (HW-I), Refuse Derived Fuel (RDF) gasification (RDF-G) and RDF incineration (RDF-I). The results of these tests were interpreted applying an integrated graphical and modelling approach aimed at identifying the main mechanisms (solubility, availability or time-controlled dissolution and diffusion) governing the release of specific constituents from each type of BA. The final aim of this work was in fact to gain insight on the information that can be provided by the leaching tests applied, and hence on which ones may be more suitable to apply for assessing the leaching concentrations expected in the field. The results of the leaching tests showed that the three samples of analysed BA presented differences of orders of magnitude in their leaching behaviour, especially as a function of pH, but also in terms of the L/S. These were mainly related to the differences in mineralogy of the samples. In addition, for the same type of bottom ash, the comparison between the results of batch and percolation column tests, expressed in terms of cumulative release, showed that for some constituents (e.g. Mg for HW-I BA and Cu for RDF-G BA) differences of over one order of magnitude were obtained due to variations in pH and DOC release. Similarly, the eluate concentrations observed in the percolation tests, for most of the investigated elements, were not directly comparable with the results of the pH-dependence tests. In particular, in some cases the percolation test results showed eluate concentrations of some constituents (e.g. K and Ca in HW-I BA) of up to one order of magnitude higher than the values obtained from the pH-dependence experiments at the same pH value. This was attributed to a rapid washout from the column of the soluble phases present in the BA. In contrast, for other constituents (e.g. Mg and Ba for the RDF-G BA), especially at high L/S ratios, the concentrations in the column tests were of up to one order of magnitude lower than the solubility value, indicating release under non-equilibrium conditions. In these cases, batch pH-dependence tests should be preferred, since column tests results could underestimate the concentrations expected in the field. Copyright © 2016 Elsevier Ltd. All rights reserved.

CHARACTERIZATION AND PH/EH-BASED LEACHING TESTS OF MINING WASTES CONTAINING MERCURY

EPA Science Inventory

This study was undertaken as a part of developing treatment alternatives for waste materials, primarily waste rock and roaster tailings, from sites contaminated with mercury (Hg) mining wastes. Leaching profiles of waste rock over a range of different pH and oxidation-reduction (...

CHARACTERIZATION AND PH/EH-BASED LEACHING TESTS OF MINING WASTES CONTAINING MERCURY

EPA Science Inventory

This study was undertaken as a part of developing treatment alternatives for waste materials, primarily waste rock and roaster tailings, from sites contaminated with Mercury (Hg) mining wastes. Leaching profiles of waste rock over a range of different pH and oxidation-reduction ...

Leaching Behavior Of Mineral Processing Waste: Comparison Of Batch And Column Investigations

EPA Science Inventory

In this study, a comparison of laboratory batch and column experiments on metal release profile from a mineral processing waste (MPW) is presented. Batch (equilibrium) and column (dynamic) leaching tests were conducted on ground MPW at different liquid–solid ratios (LS) to determ...

Alterations of lead speciation by sulfate from addition of flue ...

EPA Pesticide Factsheets

This is the first study to evaluate the potential application of FGDG as an in situ Pb stabilizer in contaminated soils with two different compositions and to explain the underlying mechanisms. A smelter Pb contaminated soil (SM-soil), rich in ferrihydrite bound Pb (FH-Pb), cerussite and litharge with a total Pb content of 65,123 mg/kg and an organic matter rich orchard soil (BO-soil), rich in FH-Pb and humic acid bound Pb with a total Pb content of 1532 mg/kg were amended with 5% FGDG (w/w). We subjected the two soils to three leaching tests; toxicity characteristic leaching protocol (TCLP), synthetic precipitation leaching protocol (SPLP), kinetic batch leaching test (KBLT) and in-vitro bioaccessibility assay (IVBA) in order to evaluate the FGDG amendment on Pb stabilization. Solid residues of original and FGDG amended soil were analyzed using X-ray absorption spectroscopy (XAS) to identify changes in Pb speciation after each leaching test. The leachate Pb concentrations of FGDG amended soil were lowered compared to those of in non-amended soil. The linear combination fitting analysis of XAS confirmed the formation of anglesite and leadhillite in FGDG amended in soil. FGDG reduced the Pb desorption from ferrihydrite (FH), by forming FH-Pb-SO4 ternary complexes. FGDG decreased the Pb adsorption onto humic acid (HA) possibly due to the release of divalent cations such as Ca and Mg, which can compete with Pb to get adsorbed onto HA. The FGDG can successful

Comparison of Hexavalent Chromium Leaching Levels of Zeoliteand Slag-based Concretes

NASA Astrophysics Data System (ADS)

Oravec, Jozef; Eštoková, Adriana

2017-06-01

In this experiment, the reference concrete samples containing Portland cement as binder and the concrete samples with the addition of ground granulated blast furnace slag (85% and 95%, respectively as replacement of Portland cement) and other samples containing ground zeolite (8% and 13%, respectively as replacement of Portland cement) were analyzed regarding the leachability of chromium. The prepared concrete samples were subjected to long-term leaching test for 300 days in three different leaching agents (distilled water, rainwater and Britton-Robinson buffer). Subsequently, the concentration of hexavalent chromium in the various leachates spectrophotometrically was measured. The leaching parameters as values of the pH and the conductivity were also studied. This experiment clearly shows the need for the regulation and control of the waste addition to the construction materials and the need for long-term study in relation to the leaching of heavy metals into the environment.

Effect of temperature on copper, iron and lead leaching from e-waste using citrate solutions.

PubMed

Torres, Robinson; Segura-Bailón, Brenda; Lapidus, Gretchen T

2018-01-01

E-waste is a potential source of large quantities of metals. The ability of citrate solutions to recover base metals from these materials has been demonstrated. In the present study, the effect of the temperature on base metal leaching capacity by the citrate solutions is determined. The material employed consisted of a mechanically prepared, gravity concentrated e-waste, with a metallic content greater than 90%. The leaching conditions were selected based on previous research performed by the authors (0.5 M sodium citrate, pH 4.5 and 20 g per liter e-waste concentrate). Leaching tests were performed at temperatures between 0° and 70 °C. The initial leaching rates for the three metals increased with temperature. However, these tapered off with time for temperatures above 30 °C, which can be associated to citrate destruction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Leaching behaviour of low level organic pollutants contained in cement-based materials: experimental methodology and modelling approach.

PubMed

Tiruta-Barna, Ligia; Fantozzi-Merle, Catherine; de Brauer, Christine; Barna, Radu

2006-11-16

The aim of this paper is the investigation of the leaching behaviour of different porous materials containing organic pollutants (PAH: naphthalene and phenanthrene). The assessment methodology of long term leaching behaviour of inorganic materials was extended to cement solidified organic pollutants. Based on a scenario-approach considering environmental factors, matrix and pollutants specificities, the applied methodology is composed of adapted equilibrium and dynamic leaching tests. The contributions of different physical and chemical mechanisms were identified and the leaching behaviour was modelled. The physical parameters of the analysed reference and polluted materials are similar. A difference in the pore size distribution appears for higher naphthalene content. The solubility of the PAH contained in the material is affected by the ionic strength and by the presence of a co-solvent; the solution pH does not influence PAH solubility. The solubility of the major mineral species is not influenced by the presence of the two PAH nor by the presence of the methanol as co-solvent in the range of the tested material compositions. In the case of the leaching of a monolith material the main transport mechanism is the diffusion in the porous system. For both mineral and organic species we observed at least two dynamic domains. At the beginning of the leaching process the released flux is due to the surface dissolution and to the diffusion of the main quantity dissolved in the initial pore solution. The second period is governed by a stationary regime between dissolution in pore water and diffusion. The model, coupling transport and chemical phenomena in the pore solution, at the monolith surface and in the leachate simulates satisfactory the release for both mineral and organic species.

Bubbles and Dust: Dissolution Rates of Unhydrated Volcanic Ash as a Function of Morphology, Composition, and Particle Size

NASA Astrophysics Data System (ADS)

Wygel, C. M.; Sahagian, D. L.

2017-12-01

Volcanic eruptions are natural hazards due to their explosive nature and widespread transportation and deposition of ash particles. After deposition and subsequent leaching in soils or water bodies, ash deposition positively (nutrients) and negatively (contaminants) impacts the health of flora and fauna, including humans. The effects of ash leachates have been difficult to replicate in field and laboratory studies due to the many complexities and differences between ash particles. Ash morphology is characteristic for each eruption, dependent upon eruption energy, and should play a critical role in determining leaching rates. Morphology reflects overall particle surface area, which is strongly influenced by the presence of surface dust. In addition, ash composition, which in part controls morphology and particle size, may also affect leaching rates. This study determines the extent to which ash morphology, surface area, composition, and particle size control ash dissolution rates. Further, it is necessary to determine whether compound vesicular ash particles permit water into their interior structures to understand if both the internal and external surface areas are available for leaching. To address this, six fresh, unhydrated ash samples from diverse volcanic environments and a large range in morphology, from Pele's spheres to vesicular compound ash, are tested in the laboratory. Ash morphology was characterized on the Scanning Electron Microscope (SEM) before and after leaching and surface area was quantified by Brunauer Emmett Teller (BET) analysis and with geometric calculations. Column Leachate Tests (CLT) were conducted to compare leaching rates over a range of basaltic to silicic ashes as a function of time and surface area, to recreate the effects of ash deposition in diverse volcanic environments. After the CLT, post-leaching water analyses were conducted by Ion Coupled Plasma-Mass Spectrometry (ICP-MS) and Ion Chromatography (IC). We find that leaching rates are correlated to characteristic surface area of ash particles.

SANSMIC Validation.

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

Weber, Paula D.; Rudeen, David Keith; Lord, David L.

2014-08-01

SANSMIC is solution mining software that was developed and utilized by SNL in its role as geotechnical advisor to the US DOE SPR for planning purposes. Three SANSMIC leach modes - withdrawal, direct, and reverse leach - have been revalidated with multiple test cases for each mode. The withdrawal mode was validated using high quality data from recent leach activity while the direct and reverse modes utilized data from historical cavern completion reports. Withdrawal results compared very well with observed data, including the location and size of shelves due to string breaks with relative leached volume differences ranging from 6more » - 10% and relative radius differences from 1.5 - 3%. Profile comparisons for the direct mode were very good with relative leached volume differences ranging from 6 - 12% and relative radius differences from 5 - 7%. First, second, and third reverse configurations were simulated in order to validate SANSMIC over a range of relative hanging string and OBI locations. The first-reverse was simulated reasonably well with relative leached volume differences ranging from 1 - 9% and relative radius differences from 5 - 12%. The second-reverse mode showed the largest discrepancies in leach profile. Leached volume differences ranged from 8 - 12% and relative radius differences from 1 - 10%. In the third-reverse, relative leached volume differences ranged from 10 - 13% and relative radius differences were %7E4 %. Comparisons to historical reports were quite good, indicating that SANSMIC is essentially the same as documented and validated in the early 1980's.« less

Copper leaching of MSWI bottom ash co-disposed with refuse: effect of short-term accelerated weathering.

PubMed

Su, Lianghu; Guo, Guangzhai; Shi, Xinlong; Zuo, Minyu; Niu, Dongjie; Zhao, Aihua; Zhao, Youcai

2013-06-01

Co-disposal of refuse with municipal solid waste incinerator (MSWI) bottom ash (IBA) either multi-layered as landfill cover or mixed with refuse could pose additional risk to the environment because of enhanced leaching of heavy metals, especially Cu. This study applied short-term accelerated weathering to IBA, and monitored the mineralogical and chemical properties of IBA during the weathering process. Cu extractability of the weathered IBA was then evaluated using standard leaching protocols (i.e. SPLP and TCLP) and co-disposal leaching procedure. The results showed that weathering had little or no beneficial effect on Cu leaching in SPLP and TCLP, which can be explained by the adsorption and complexation of Cu with DOM. However, the Cu leaching of weathered IBA was reduced significantly when situated in fresh simulated landfill leachate. This was attributed to weakening Cu complexation with fulvic acid or hydrophilic fractions and/or intensifying Cu absorption to neoformed hydr(oxide) minerals in weathered IBA. The amount of total leaching Cu and Cu in free or labile complex fraction (the fraction with the highest mobility and bio-toxicity) of the 408-h weathered IBA were remarkably decreased by 86.3% and 97.6% in the 15-day co-disposal leaching test. Accelerated weathering of IBA may be an effective pretreatment method to decrease Cu leaching prior to its co-disposal with refuse. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Poisoning by household products].

PubMed

Lambert, H; Manel, J; Gabrion, I

2000-02-15

Caustic products are responsible for the most serious cases of poisoning, which are always emergency cases. Application of current intervention procedures has decreased both morbidity and mortality. Water-diluted bleach, the ingestion of which remains extremely frequent, is a moderate irritant rather than a caustic product. Emission of gas produced when mixing bleach with other agents can be responsible for choking gas poisoning. Anionic and nonionic detergents are mostly dangerous because of their foam-producing properties. Mercury vapours and methanol are other potentially hazardous products.

Wave Chaos and HPM Effects on Electronic Systems

DTIC Science & Technology

2013-08-13

if one examines these pas- sages, one will find that, as the orbit length approaches infinity, (i) the fraction of time spent by the orbit in the...as the orbits in a complete quarter circle billiard having the same radius R (see Fig. 3.2(a)). These orbits are tangent to a circular caustic 62 with...a radius Cr. If the caustic radius Cr > ρ0, (see Fig. 3.1) this orbit is trapped in the cap, and is integrable. There are also chaotic orbits that

Minutes of the Explosives Safety Seminar (25th) Held in Anaheim, California on 18-20 August 1992. Volume 1

DTIC Science & Technology

1992-08-20

project. There is no doubt that we would have otherwise spent many years in proving project feasibility and trialing the specific demilitarisation...SUCH ROCKET MOTORS AS THE ONE USED IN THE BULLPUP SYSTEM WERE CONSIDERED. A. DRAINING AND NEUTRALIZING THE OXIDIZER BY CAUSTIC SODA AND THEN SIMPLE...INHIBITED RED FUMING NITRIC ACID WAS DETECTED IN SMALL AMOUNTS. 482 CONSEQUENTLY. THE "EMPTY" CASES WERE PLACED INTO A TANK CONTAINING WATER AND CAUSTIC

Leaching Environmental Assessment Framework (LEAF) How-To Guide - Understanding the LEAF Approach and How and When to Use It

EPA Science Inventory

This document is intended to present the reader with important technical and decision-making information in a user-friendly format for implementation of the Leaching Environmental Assessment Framework (LEAF)test methods 1313, 1314, 1315, and 1316 for inorganic constituents. The ...

A LABORATORY STUDY OF LEAD LEACHING FROM DRINKING WATER FAUCETS

EPA Science Inventory

A test pilot system was constructed to evaluate lead leaching from 12 different kitchen faucets. torage tank, pressure pump, and manifold System was operated to simulate, as closely as possible, the use of the faucets In a household plumbing system. eaching of lead from the fauce...

Workshop Report: Considerations for Developing Leaching Test Methods for Semi- and Non-Volatile Organic Compounds

EPA Pesticide Factsheets

Documents a September 2015 workshop on how to evaluate the potential for leaching of semi- or non-volatile organic constituents at contaminated sites where in place treatment has been used to control migration, and from waste that is disposed or re-used.

Development and Use of the Leaching Environmental Assessment Framework in the United States

EPA Science Inventory

The purpose of this presentation is to provide technical expertise at an upcoming workshop to discuss the use of EPA’s new leaching tests at a workshop on “Risk Informed Approaches and Regulations for Reclamation, Treatment, Use orDisposal”. This presentation has been requested b...

Combining SBR systems for chemical and biological treatment: the destruction of the nerve agent VX.

PubMed

Irvine, R L; Haraburda, S S; Galbis-Reig, C

2004-01-01

The US Army is pilot testing the neutralization of VX nerve agent stockpiled at Newport, Indiana using caustic hydrolysis in a Sequencing Batch Reactor (SBR). The resulting hydrolysate was tested at the bench-scale for treatment with activated sludge biodegradation in two distinct studies, one in the SBR and another, in the PACT process. The feed to both biological systems was pretreated to enhance the biodegradability of the hydrolysis products. Both biodegradation studies demonstrated that the hydrolysate could easily meet the Chemical Weapons Convention treaty and US environmental regulations following pretreatment.

Inhibition of nuclear waste solutions containing multiple aggressive anions

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

Congdon, J.W.

1988-01-01

The inhibition of localized corrosion of carbon steel in caustic, high-level radioactive waste solutions was studied using cyclic potentiodynamic polarization scans, supplemented by partially immersed coupon tests. The electrochemical tests provided a rapid and accurate means of determining the relationship between the minimum inhibitor requirements and the concentration of the aggressive anions in this system. Nitrate, sulfate, chloride, and fluoride were identified as aggressive anions, however, no synergistic effects were observed between these anions. This observation may have important theoretical implications because it tends to contradict the behavior of aggressive anions as predicted by existing theories for localized corrosion.

Inhibition of nuclear waste solutions containing multiple aggressive anions

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

Congdon, J.W.

1988-05-01

The inhibition of localized corrosion of carbon steel in caustic, high-level radioactive waste solutions was studied using cyclic potentiodynamic polarization scans supplemented by partially immersed coupon tests. The electrochemical tests provided a rapid and accurate means of determining the relationship between the minimum inhibitor requirements and the concentration of the aggressive anions in this system. Nitrate, sulfate, chloride, and fluoride were identified as aggressive anions; however, no synergistic effects were observed between these anions. This observation may have important theoretical implications because it tends to contradict the behavior of aggressive anions as predicted by existing theories for localized corrosion.

Characterization and metal availability of copper, lead, antimony and zinc contamination at four Canadian small arms firing ranges.

PubMed

Laporte-Saumure, Mathieu; Martel, Richard; Mercier, Guy

2011-01-01

Backstop soils of four small-arms firing ranges (SAFRs) of the Canadian Force Bases (CFBs) were characterized in terms of their total soil Cu, Pb, Sb and Zn concentrations, grain size distribution, mineralogy, chemical properties, vertical in-depth contamination distribution (for one CFB), and scanning electron microscope (SEM-EDS) characterization. Metal availability from the soils was evaluated with three leaching tests: the toxicity characteristics leaching procedure (TCLP), representing a landfill leachate; the synthetic precipitation leaching procedure (SPLP), representing field conditions; and the gastric juice simulation test (GJST), representing the leachate of the human stomach during the digestive process and, therefore, the potential metal transfer to humans in the case of soil ingestion. Metal analyses of soils and leaching test extracts were conducted with an Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) instrument. Total soil results showed maximal concentrations of 27,100 mg/kg for Pb, 7720 mg/kg for Cu, 1080 mg/kg for Zn, and 570 mg/kg for Sb. The SEM-EDS analysis showed significant amounts of lead carbonates, which resulted from the alteration of the initial metallic Pb particles. Metal availability evaluation with the leaching tests showed that TCLP Pb and Sb thresholds were exceeded. For the SPLP and the GJST, the drinking water thresholds of the Ministère du Développement Durable, de l'Environnement et des Pares (MDDEP) of Quebec were exceeded by Pb and Sb. The metal availability assessment showed that SAFR backstop soils may pose a potential risk to the environment, groundwater and humans, and affect the management of such soils in order to minimize potential metal dispersion in the environment.

Leachate concentrations from water leach and column leach tests on fly ash-stabilized soils

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

Bin-Shafique, S.; Benson, C.H.; Edil, T.B.

2006-01-15

Batch water leaching tests (WLTs) and column leaching tests (CLTs) were conducted on coal-combustion fly ashes, soil, and soil-fly ash mixtures to characterize leaching of Cd, Cr, Se, and Ag. The concentrations of these metals were also measured in the field at two sites where soft fine-grained soils were mechanically stabilized with fly ash. Concentrations in leachate from the WLTs on soil-fly ash mixtures are different from those on fly ash alone and cannot be accurately estimated based on linear dilution calculations using concentrations from WLTs on fly ash alone. The concentration varies nonlinearly with fly ash content due tomore » the variation in pH with fly ash content. Leachate concentrations are low when the pH of the leachate or the cation exchange capacity (CEC) of the soil is high. Initial concentrations from CLTs are higher than concentrations from WLTs due to differences in solid-liquid ratio, pH, and solid-liquid contact. However, both exhibit similar trends with fly ash content, leachate pH, and soil properties. Scaling factors can be applied to WLT concentrations (50 for Ag and Cd, 10 for Cr and Se) to estimate initial concentrations for CLTs. Concentrations in leachate collected from the field sites were generally similar or slightly lower than concentrations measured in CLTs on the same materials. Thus, CLTs appear to provide a good indication of conditions that occur in the field provided that the test conditions mimic the field conditions. In addition, initial concentrations in the field can be conservatively estimated from WLT concentrations using the aforementioned scaling factors provided that the pH of the infiltrating water is near neutral.« less

Fatigue Testing of AA7050-T7451 with Various Corrosion Prevention Surface Treatments

DTIC Science & Technology

2013-06-01

UNCLASSIFIED Authors Marcus McDonald Air Vehicles Division Marcus McDonald initially spent 3 years working in the oil & gas, steel and...treatments: caustic degreasing, de-oxidising or anodising. The pits in the anodised coupons were larger than the pits caused by the pre-IVD etching...those fatigue cracks that grew from them spent less time in growing whilst they were small, because the crack started at what was a larger effective

Fire and explosion hazards related to the industrial use of potassium and sodium methoxides.

PubMed

Kwok, Q; Acheson, B; Turcotte, R; Janès, A; Marlair, G

2013-04-15

Sodium and potassium methoxides are used as an intermediary for a variety of products in several industrial applications. For example, current production of so called "1G-biodiesel" relies on processing a catalytic reaction called "transesterification". This reaction transforms lipid resources from biomass materials into fatty acid methyl and ethyl esters. 1-G biodiesel processes imply the use of methanol, caustic potash (KOH), and caustic soda (NaOH) for which the hazards are well characterized. The more recent introduction of the direct catalysts CH3OK and CH3ONa may potentially introduce new process hazards. From an examination of existing MSDSs concerning these products, it appears that no consensus currently exists on their intrinsic hazardous properties. Recently, l'Institut National de l'Environnement Industriel et des Risques (France) and the Canadian Explosives Research Laboratory (Canada) have embarked upon a joint effort to better characterize the thermal hazards associated with these catalysts. This work employs the more conventional tests for water reactivity as an ignition source, fire and dust explosion hazards, using isothermal nano-calorimetry, isothermal basket tests, the Fire Propagation Apparatus and a standard 20 L sphere, respectively. It was found that these chemicals can become self-reactive close to room temperature under specific conditions and can generate explosible dusts. Copyright © 2013 Crown. Published by Elsevier B.V. All rights reserved.

Effect of Harsh or Mild Extraction of Soil on Pesticide Leaching to Groundwater.

PubMed

Boesten, Jos J T I

2016-07-01

Assessment of leaching to groundwater is an important aspect of pesticide risk assessment. The first leaching tier usually consists of simulations with leaching scenarios based on pesticide-soil properties derived from laboratory studies. Because the extractability of pesticide residues in such studies decreases with time, the harshness of the extraction method influences these pesticide-soil properties. This study investigates the effect of using a mild or harsh extraction method on simulated leaching to groundwater with consideration of substances with a range of half-lives and organic matter sorption coefficient values for selected leaching scenarios. The model for linking the concentrations of the mild and the harsh systems was based on laboratory studies with two pesticides and a Dutch sandy soil and was tested against Canadian field studies with atrazine (6-chloro-2-ethyl-4-isopropyl-1,3,5-triazine-2,4-diamine). The degradation rate and the aged-sorption parameters of each "mild" soil-substance system were derived from a hypothetical laboratory incubation study using prescribed parameter values for the corresponding "harsh" soil-substance system. Simulations were performed for three European leaching scenarios (United Kingdom, France, Portugal). For the best-guess parameter set, the leaching concentrations of the harsh system were approximately equal to those of the mild system at leaching concentrations greater than 1 μg L and were at most approximately a factor of two higher than those of the mild systems at mild leaching concentrations between 0.01 and 0.1 μg L. However, an extreme parameter set led to harsh leaching concentrations that were at most approximately 10 times higher than the mild leaching concentrations at levels between 0.01 and 0.1 μg L. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Recovery of valuable metals from spent lithium-ion batteries by ultrasonic-assisted leaching process

NASA Astrophysics Data System (ADS)

Li, Li; Zhai, Longyu; Zhang, Xiaoxiao; Lu, Jun; Chen, Renjie; Wu, Feng; Amine, Khalil

2014-09-01

The anticipated significant use of lithium-ion batteries (LIBs) for energy storage applications in electric grid modernization and vehicle electrification shall generate a large quantity of solid waste that could become potential environmental hazards and waste natural resources. Recycling of the major components from spent LIBs is, therefore, considered desirable to prevent environmental pollution and to recycle valuable metals. This study reports on the application of ultrasonic-assisted technology to the leaching of cobalt and lithium from the cathode active materials of spent LIBs. Three acids were tested for the leaching process: two inorganic acids (H2SO4 and HCl) and one organic acid (citric acid, C6H8O7·H2O). The results show that the leaching of Co and Li is more efficient with citric acid than with the two inorganic acids. More than 96% Co and nearly 100% Li were recovered from spent LIBs. The optimal leaching conditions were 0.5 M citric acid with 0.55 M H2O2, a solid-to-liquid ratio of 25 g L-1, a temperature of 60 °C, leaching time of 5 h, and ultrasonic power of 90 W. The high leaching efficiency is mainly ascribed to the unique cavitation action of the ultrasonic waves. This ultrasonic-assisted leaching process with organic acid is not only effective but also environmentally friendly.

Reuse of steel slag in bituminous paving mixtures.

PubMed

Sorlini, Sabrina; Sanzeni, Alex; Rondi, Luca

2012-03-30

This paper presents a comprehensive study to evaluate the mechanical properties and environmental suitability of electric arc furnace (EAF) steel slag in bituminous paving mixtures. A variety of tests were executed on samples of EAF slag to characterize the physical, geometrical, mechanical and chemical properties as required by UNI EN specifications, focusing additionally on the volumetric expansion associated with hydration of free CaO and MgO. Five bituminous mixtures of aggregates for flexible road pavement were designed containing up to 40% of EAF slag and were tested to determine Marshall stability and indirect tensile strength. The leaching behaviour of slag samples and bituminous mixtures was evaluated according to the UNI EN leaching test. The tested slag showed satisfactory physical and mechanical properties and a release of pollutants generally below the limits set by the Italian code. Tests on volume stability of fresh materials confirmed that a period of 2-3 months is necessary to reduce effects of oxides hydration. The results of tests performed on bituminous mixtures with EAF slag were comparable with the performance of mixtures containing natural aggregates and the leaching tests provided satisfactory results. Copyright © 2012 Elsevier B.V. All rights reserved.

Anaerobic degradation of renewable biomass for production of methane

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

Rajoka, M.I.; Tabassum, R.; Malik, K.A.

1996-12-31

Anaerobic degradation of renewable biomass namely kallar grass (KG) (Leptochloafusca L. Kunth), Atriplex sp, wheat straw, cotton stalk, cotton lint and molasses was carried out at 37{degrees}C in a 15 litre fermentor, using laboratory enriched co-culture of fermentative, acetogenic and methanogenic organisms. Maximum reduction of volatile solids (VS) was from causticized KG, and cotton lint, followed by causticized wheat straw and Atriplex sp. followed by causticized wheat straw and Atriplex sp. Maximum production of methane was obtained from NaOH-pretreated KG with a process product yield (Y{sub p/s}) of 0.9 m{sup 3}/kg VS with a volumetric productivity (Q{sub p}) of 4.24more » L/day after 19 days of fermentation. Maximum methane content in the gas mixture was 96% with average of 78.6{+-}21.6. The Y{sub p/s} in 1000 litre digestor was 0.7 m{sup 3}/kg VS from a 3% suspension of uncaustisized kallar grass.« less

Microbial Fuel Cell-driven caustic potash production from wastewater for carbon sequestration.

PubMed

Gajda, Iwona; Greenman, John; Melhuish, Chris; Santoro, Carlo; Ieropoulos, Ioannis

2016-09-01

This work reports on the novel formation of caustic potash (KOH) directly on the MFC cathode locking carbon dioxide into potassium bicarbonate salt (kalicinite) while producing, instead of consuming electrical power. Using potassium-rich wastewater as a fuel for microorganisms to generate electricity in the anode chamber, has resulted in the formation of caustic catholyte directly on the surface of the cathode electrode. Analysis of this liquid has shown to be highly alkaline (pH>13) and act as a CO2 sorbent. It has been later mineralised to kalicinite thus locking carbon dioxide into potassium bicarbonate salt. This work demonstrates an electricity generation method as a simple, cost-effective and environmentally friendly route towards CO2 sequestration that perhaps leads to a carbon negative economy. Moreover, it shows a potential application for both electricity production and nutrient recovery in the form of minerals from nutrient-rich wastewater streams such as urine for use as fertiliser in the future. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Sodium to sodium carbonate conversion process

DOEpatents

Herrmann, S.D.

1997-10-14

A method is described for converting radioactive alkali metal into a low level disposable solid waste material. The radioactive alkali metal is atomized and introduced into an aqueous caustic solution having caustic present in the range of from about 20 wt % to about 70 wt % to convert the radioactive alkali metal to a radioactive alkali metal hydroxide. The aqueous caustic containing radioactive alkali metal hydroxide and CO{sub 2} are introduced into a thin film evaporator with the CO{sub 2} present in an amount greater than required to convert the alkali metal hydroxide to a radioactive alkali metal carbonate, and thereafter the radioactive alkali metal carbonate is separated from the thin film evaporator as a dry powder. Hydroxide solutions containing toxic metal hydroxide including one or more metal ions of Sb, As, Ba, Be, Cd, Cr, Pb, Hg, Ni, Se, Ag and Tl can be converted into a low level non-hazardous waste using the thin film evaporator of the invention. 3 figs.

Effect of solvent addition sequence on lycopene extraction efficiency from membrane neutralized caustic peeled tomato waste.

PubMed

Phinney, David M; Frelka, John C; Cooperstone, Jessica L; Schwartz, Steven J; Heldman, Dennis R

2017-01-15

Lycopene is a high value nutraceutical and its isolation from waste streams is often desirable to maximize profits. This research investigated solvent addition order and composition on lycopene extraction efficiency from a commercial tomato waste stream (pH 12.5, solids ∼5%) that was neutralized using membrane filtration. Constant volume dilution (CVD) was used to desalinate the caustic salt to neutralize the waste. Acetone, ethanol and hexane were used as direct or blended additions. Extraction efficiency was defined as the amount of lycopene extracted divided by the total lycopene in the sample. The CVD operation reduced the active alkali of the waste from 0.66 to <0.01M and the moisture content of the pulp increased from 93% to 97% (wet basis), showing the removal of caustic salts from the waste. Extraction efficiency varied from 32.5% to 94.5%. This study demonstrates a lab scale feasibility to extract lycopene efficiently from tomato processing byproducts. Published by Elsevier Ltd.

Mineral transformation controls speciation and pore-fluid transmission of contaminants in waste-weathered Hanford sediments

NASA Astrophysics Data System (ADS)

Perdrial, Nicolas; Thompson, Aaron; O'Day, Peggy A.; Steefel, Carl I.; Chorover, Jon

2014-09-01

Portions of the Hanford Site (WA, USA) vadose zone were subjected to weathering by caustic solutions during documented releases of high level radioactive waste (containing Sr, Cs and I) from leaking underground storage tanks. Previous studies have shown that waste-sediment interactions can promote variable incorporation of contaminants into neo-formed mineral products (including feldspathoids and zeolites), but processes regulating the subsequent contaminant release from these phases into infiltrating background pore waters remain poorly known. In this paper, reactive transport experiments were conducted with Hanford sediments previously weathered for one year in simulated hyper-alkaline waste solutions containing high or low 88Sr, 127I, and 133Cs concentrations, with or without CO2(aq). These waste-weathered sediments were leached in flow-through column experiments with simulated background pore water (characteristic of meteoric recharge) to measure contaminant release from solids formed during waste-sediment interaction. Contaminant sorption-desorption kinetics and mineral transformation reactions were both monitored using continuous-flow and wet-dry cycling regimes for ca. 300 pore volumes. Less than 20% of contaminant 133Cs and 88Sr mass and less than 40% 127I mass were released over the course of the experiment. To elucidate molecular processes limiting contaminant release, reacted sediments were studied with micro- (TEM and XRD) and molecular- (Sr K-edge EXAFS) scale methods. Contaminant dynamics in column experiments were principally controlled by rapid dissolution of labile solids and competitive exchange reactions. In initially feldspathoidic systems, time-dependent changes in the local zeolitic bonding environment observed with X-ray diffraction and EXAFS are responsible for limiting contaminant release. Linear combination fits and shell-by-shell analysis of Sr K-edge EXAFS data revealed modification in Sr-Si/Al distances within the zeolite cage. Wet-dry cycling did not affect significantly molecular-scale transformations relative to continuous-flow controls. Results indicate that contaminants bound to the solid phase in distinct micro- and molecular-scale coordinative environments can generate similar macro-scale release behaviors, highlighting the need for multi-scale interrogations to constrain mechanisms of reactive transport. Data also indicate that weathering-induced change in ion exchange selectivity coefficients should be incorporated in simulations of contaminant release from caustic high-level radioactive waste impacted sediments.

Relativistic Effects and Polarization in Three High-Energy Pulsar Models

NASA Technical Reports Server (NTRS)

Dyks, J.; Harding, Alice K.; Rudak, B.

2004-01-01

We present the influence of the special relativistic effects of aberration and light travel time delay on pulsar high-energy lightcurves and polarization characteristics predicted by three models: the two-pole caustic model, the outer gap model, and the polar cap model. Position angle curves and degree of polarization are calculated for the models and compared with the optical data on the Crab pulsar. The relative positions of peaks in gamma-ray and radio lightcurves are discussed in detail for the models. We find that the two-pole caustic model can reproduce qualitatively the optical polarization characteristics of the Crab pulsar - fast swings of the position angle and minima in polarization degree associated with both peaks. The anticorrelation between the observed flux and the polarization degree (observed in the optical band also for B0656+14) naturally results from the caustic nature of the peaks which are produced in the model due to the superposition of radiation from many different altitudes, ie. polarized at different angles. The two-pole caustic model also provides an acceptable interpretation of the main features in the Crab's radio profile. Neither the outer gap model nor the polar cap model are able to reproduce the optical polarization data on the Crab. Although the outer gap model is very successful in reproducing the relative positions of gamma-ray and radio peaks in pulse profiles, it can reproduce the high-energy lightcurves only when photon emission from regions very close to the light cylinder is included.

Computed Tomography Evaluation of Esophagogastric Necrosis After Caustic Ingestion.

PubMed

Chirica, Mircea; Resche-Rigon, Matthieu; Zagdanski, Anne Marie; Bruzzi, Matthieu; Bouda, Damien; Roland, Eric; Sabatier, François; Bouhidel, Fatiha; Bonnet, Francine; Munoz-Bongrand, Nicolas; Marc Gornet, Jean; Sarfati, Emile; Cattan, Pierre

2016-07-01

Endoscopy is the standard of care for emergency patient evaluation after caustic ingestion. However, the inaccuracy of endoscopy in determining the depth of intramural necrosis may lead to inappropriate decision-making with devastating consequences. Our aim was to evaluate the use of computed tomography (CT) for the emergency diagnostic workup of patients with caustic injuries. In a prospective study, we used a combined endoscopy-CT decision-making algorithm. The primary outcome was pathology-confirmed digestive necrosis. The respective utility of CT and endoscopy in the decision-making process were compared. Transmural endoscopic necrosis was defined as grade 3b injuries; signs of transmural CT necrosis included absence of postcontrast gastric/ esophageal-wall enhancement, esophageal-wall blurring, and periesophageal-fat blurring. We included 120 patients (59 men, median age 44 years). Emergency surgery was performed in 24 patients (20%) and digestive resection was completed in 16. Three patients (3%) died and 28 patients (23%) experienced complications. Pathology revealed transmural necrosis in 9/11 esophagectomy and 16/16 gastrectomy specimens. Severe oropharyngeal injuries (P = 0.015), increased levels of blood lactate (P = 0.007), alanine aminotransferase (P = 0.027), bilirubin (P = 0.005), and low platelet counts (P > 0.0001) were predictive of digestive necrosis. Decision-making relying on CT alone or on a combined CT-endoscopy algorithm was similar and would have spared 19 unnecessary esophagectomies and 16 explorative laparotomies compared with an endoscopy-alone algorithm. Endoscopy did never rectify a wrong CT decision. Emergency decision-making after caustic injuries can rely on CT alone.

Comparative leaching of six toxic metals from raw and chemically stabilized MSWI fly ash using citric acid.

PubMed

Wang, Huawei; Fan, Xinxiu; Wang, Ya-Nan; Li, Weihua; Sun, Yingjie; Zhan, Meili; Wu, Guizhi

2018-02-15

The leaching behavior of six typical toxic metals (Pb, Zn, Cr, Cd, Cu and Ni) from raw and chemically stabilized (phosphate and chelating agent) municipal solid waste incineration (MSWI) fly ash were investigated using citric acid. Leaching tests indicated that phosphate stabilization can effectively decrease the leaching of Zn, Cd and Cr; whereas chelating agent stabilization shows a strong ability to lower the release of Pb, Cd and Cu, but instead increases the solubility of Zn and Cr at low pH conditions. Sequential extraction results suggested that the leaching of Pb, Zn and Cd in both the stabilized MSWI fly ash samples led to the decrease in Fe/Mn oxide fraction and the increase in exchangeable and carbonate fractions. The leaching of Cr was due to the decrease in exchangeable, carbonate and Fe/Mn oxide fractions in phosphate-stabilized and chelating agent-stabilized MSWI fly ash. The leaching of Cu in both stabilized MSWI fly ash was greatly ascribed to the decrease in Fe/Mn oxide and oxidisable fractions. Moreover, predicted curves by geochemical model indicated that both stabilized MSWI fly ash have the risk of releasing toxic metals under strong acid environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dynamic leaching behavior of geogenic As in soils after cement-based stabilization/solidification.

PubMed

Li, Jiang-Shan; Wang, Lei; Tsang, Daniel C W; Beiyuan, Jingzi; Poon, Chi Sun

2017-12-01

Cement-based stabilization/solidification (S/S) is a practical treatment approach for hazardous waste with anthropogenic As sources; however, its applicability for geogenic As-containing soil and the long-term leaching potential remain uncertain. In this study, semi-dynamic leaching test was performed to investigate the influence of S/S binders (cement blended with fuel ash (FA), furnace bottom ash (FBA), or ground granulated blast furnace slag (GGBS)) on the long-term leaching characteristics of geogenic As. The results showed that mineral admixtures with higher Ca content and pozzolanic activity were more effective in reducing the leached As concentrations. Thus, cement blended with FBA was inferior to other binders in suppressing the As leaching, while 20% replacement of ordinary Portland cement by GGBS was considered most feasible for the S/S treatment of As-containing soils. The leachability of geogenic As was suppressed by the encapsulation effect of solidified matrix and interlocking network of hydration products that were supported by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) results. The long-term leaching of geogenic As from the monolithic samples was diffusion-controlled. Increasing the Ca content in the samples led to a decrease in diffusion coefficient and an increase in feasibility for "controlled utilization" of the S/S-treated soils.

Antimony leaching in plastics from waste electrical and electronic equipment (WEEE) with various acids and gamma irradiation.

PubMed

Tostar, Sandra; Stenvall, Erik; Boldizar, Antal; Foreman, Mark R St J

2013-06-01

There has been a recent interest in antimony since the availability in readily mined areas is decreasing compared to the amounts used. It is important in many applications such as flame retardants and in the production of polyester, which can trigger an investigation of the leachability of antimony from plastics using different acids. In this paper, different types of acids are tested for their ability to leach antimony from a discarded computer housing, made of poly(acrylonitrile butadiene styrene), which is a common plastic type used in electrical and electronic equipment. The acid solutions included sodium hydrogen tartrate (0.5M) dissolved in either dimethyl sulfoxide or water (at ca. 23°C and heated to ca. 105°C). The metal content after leaching was determined by inductively coupled plasma optical emission spectroscopy. The most efficient leaching medium was the heated solution of sodium hydrogen tartrate in dimethyl sulfoxide, which leached almost half of the antimony from the poly(acrylonitrile butadiene styrene). Gamma irradiation, which is proposed to improve the mechanical properties in plastics, was used here to investigate the influence of antimony leaching ability. No significant change in the amount of leached antimony could be observed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Leaching mechanisms of constituents from fly ash under the influence of humic acid.

PubMed

Zhao, Shengxin; Chen, Zhonglin; Shen, Jimin; Kang, Jing; Zhang, Jin; Shen, Yanqing

2017-01-05

As a low-cost material for adsorption, FA is one of the most efficient adsorbents of HA. However, the leaching of elements from FA is problematic during utilization in water treatment. In this investigation, the potential leaching behaviors of Calcium, Arsenic, Born, Chromium, and other elements from FA in HA solution were studied via batch test. The data show that HA had an effect on the leaching of each element of FA, depending on the pH, the initial concentration of HA and the addition of calcium oxide (CaO). The Langmuir isotherm could better fit the equilibrium data in different initial concentrations of HA from 10 to 100mg/L. Because of the interaction between HA and the FA leaching elements, multi-layer adsorption occurred when the initial concentration of HA was more than 100mg/L. The pH and free CaO content played major roles in HA adsorption and FA leaching. Using SEM and XRD to characterize the solid of FA being mixed with CaO treated in solution, the results demonstrated that the reaction between FA and CaO could generate crystal minerals, such as portlandite, gismondine, ettringite (AFt) and calcite, which effectively restrained the leaching of elements, reduced secondary pollution. Copyright © 2016 Elsevier B.V. All rights reserved.

Seismic structures in the inner and outer core constrained by the PKP observations near the caustic distance range

NASA Astrophysics Data System (ADS)

Yu, W.; Wen, L.; Niu, F.

2002-05-01

We have extensively collected PKP waveforms around the PKP caustic distance range (141o - 147o) recorded in several dense regional arrays and the Global Seismic Network covering from 1990 to 2000. PKP observations at this distance range (141o - 147o) are usually purposely avoided in travel time analyses, because of the interference of various PKP branches. The observations there, however, will be extremely useful for constraining the seismic structures at both the top of the inner core and the bottom of the outer core. Moreover, because PKIKP phases sample a depth range of 100 km - 170 km below the inner-core boundary at this distant range, their observations fill the sampling depth gap between the PKiKP-PKIKP observations at the smaller distances and the PKPbc-PKIKP phases at the larger distances. Before the PKP caustics (141o - 145o), the diffracted PKP phases near the B caustics (PKPBdiff) and PKiKP phases are discernible in the long-period seismograms, and their differential travel times and waveforms could be used to constrain seismic structures at the bottom of the outer core and/or at the base of the mantle. The observed long-period PKiKP-PKPBdiff waveforms exhibit a hemispheric difference between those sampling the "eastern" and "western" hemispheres, with those sampling the "western" hemisphere showing larger time separations between the two phases. These observations can be explained by models with P velocity gradients of 0.0806 (km/s)/ 200 km for the "western" hemisphere and 0.114 (km/s)/200 km for the "eastern" hemisphere at the bottom of the outer core. Alternatively, these observations can also be explained by models with different velocity structures at the bottom 200 km of the mantle with P velocity variations in an order of 3 percent with respect to PREM. Broadband PKP observations after the PKP caustics (145o - 147o), on the other hand, provide high-quality constraints on the seismic structures at both the top of the inner core and the bottom of the outer core, as PKPbc phases can be used as excellent reference phases. We explore seismic models in both the bottom of the outer core and the top of the inner core, which can consistently explain the seismic observations at the caustic distance range (141o - 147o) and the PKiKP-PKIKP observations at the closer distances (Niu and Wen, Nature, 410, 1081-1084, 2001, Wen and Niu, JGR, submitted).

Modeling and mitigation of denitrification 'woodchip' bioreactor phosphorus releases during treatment of aquaculture wastewater

USDA-ARS?s Scientific Manuscript database

Denitrification 'woodchip' bioreactors designed to remove nitrate from agricultural waters may either be phosphorus sources or sinks. A 24 d batch test showed woodchip leaching is an important source of phosphorus during bioreactor start-up with a leaching potential of approximately 20 -30 mg P per ...

CHARACTERIZATION AND EH/PH-BASED LEACHING TESTS OF MERCURY-CONTAINING MINING WASTES FROM THE SULFUR BANK MERCURY MINE, LAKE COUNTY, CALIFORNIA

EPA Science Inventory

Mine waste rock and roaster tailings were collected from the Sulfur Bank Mercury Mine (SBMM) located in Clearlake Oaks, California. The site has been under investigation as a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) site. Leaching profiles o...

Leach and mold resistance of essential oil metabolites

Treesearch

Carol A. Clausen; Vina W. Yang

2011-01-01

Purified primary metabolites from essential oils were previously shown to be bioactive inhibitors of mold fungi on unleached Southern pine sapwood, either alone or in synergy with a second metabolite. This study evaluated the leachability of these compounds in Southern pine that was either dip- or vacuum-treated. Following laboratory leach tests, specimens were...

Leaching, geochemical modelling and field verification of a municipal solid waste and a predominantly non-degradable waste landfill.

PubMed

van der Sloot, H A; Kosson, D S; van Zomeren, A

2017-05-01

In spite of the known heterogeneity, wastes destined for landfilling can be characterised for their leaching behaviour by the same protocols as soil, contaminated soil, sediments, sludge, compost, wood, waste and construction products. Characterisation leaching tests used in conjunction with chemical speciation modelling results in much more detailed insights into release controlling processes and factors than single step batch leaching tests like TCLP (USEPA) and EN12457 (EU Landfill Directive). Characterisation testing also can provide the potential for mechanistic impact assessments by making use of a chemical speciation fingerprint (CSF) derived from pH dependence leaching test results. This CSF then forms the basis for subsequent chemical equilibrium and reactive transport modelling to assess environmental impact in a landfill scenario under relevant exposure conditions, including conditions not readily evaluated through direct laboratory testing. This approach has been applied to municipal solid waste (MSW) and predominantly non-degradable waste (PNW) that is representative of a significant part of waste currently being landfilled. This work has shown that a multi-element modelling approach provides a useful description of the release from each of these matrices because relevant release controlling properties and parameters (mineral dissolution/precipitation, sorption on Fe and Al oxides, clay interaction, interaction with dissolved and particulate organic carbon and incorporation in solid solutions) are taken into consideration. Inclusion of dissolved and particulate organic matter in the model is important to properly describe release of the low concentration trace constituents observed in the leachate. The CSF allows the prediction of release under different redox and degradation conditions in the landfill by modifying the redox status and level of dissolved and particulate organic matter in the model runs. The CSF for MSW provides a useful starting point for comparing leachate data from other MSW landfills. Copyright © 2016 Elsevier Ltd. All rights reserved.

A risk-based approach for assessing the recycling potential of an alkaline waste material as road sub-base filler material.

PubMed

Di Gianfilippo, Martina; Verginelli, Iason; Costa, Giulia; Spagnuolo, Riccardo; Gavasci, Renato; Lombardi, Francesco

2018-01-01

In this work we present an integrated risk-based approach that can be used to evaluate the recycling potential of an alkaline waste material such as incineration bottom ash (BA) as unbound material for road sub-base construction. This approach, which is aimed at assessing potential risks to the groundwater resource (in terms of drinking water quality) and human health associated to the leaching of contaminants from the BA, couples the results of leaching tests for the estimation of source concentrations with the fate and transport models usually adopted in risk assessment procedures. The effects of weathering and of the type of leaching test employed to evaluate eluate concentrations were assessed by carrying out different simulations using the results of laboratory leaching tests. Specifically, pH-dependence and column percolation leaching tests were performed on freshly collected and 1-year naturally weathered BA samples produced from a grate-fired incineration plant treating Refuse Derived Fuel (RDF). To evaluate a broad span of possible scenario conditions, a Monte Carlo analysis was performed running 5000 simulations, randomly varying the input parameters within the ranges expected in the field. In nearly all the simulated conditions, the concentrations of contaminants in the groundwater for the specific type of BA tested in this work were well below EU and WHO drinking water quality criteria. Nevertheless, some caution should be paid in the case of the establishment of acidic conditions in the field since in this case the concentration of some elements (i.e. Al, Pb and Zn) is expected to exceed threshold values. In terms of risks to human health, for the considered utilization scenario the probability of exceeding the acceptable reference dose for water ingestion was usually less than 1% (except for Cr and Pb for which the probability was lower than 3.5% and 7%, respectively). Copyright © 2017 Elsevier Ltd. All rights reserved.

Leaching behavior of rare earth elements in fort union lignite coals of North America

DOE PAGES

Laudal, Daniel A.; Benson, Steven A.; Addleman, Raymond Shane; ...

2018-03-30

Fort Union lignite coal samples were subjected to a series of aqueous leaching experiments to understand the extraction behavior of the rare earth elements (REE). This testing was aimed at understanding the modes of occurrence of the REE in the lignite coals, as well as to provide foundational data for development of rare earth extraction processes. In a first series of tests, a sequential leaching process was used to investigate modes of occurrence of the REE of select lignite coals. The tests involved sequential exposure to solvents consisting of water, ammonium acetate and dilute hydrochloric acid (HCl). The results indicatedmore » that water and ammonium acetate extracted very little of the REE, indicating the REE are not present as water soluble or ion-exchangeable forms. However, the data shows that a large percentage of the REE were extracted with the hydrochloric acid (80–95 wt%), suggesting presence in HCl-soluble mineral forms such as carbonates, and/or presence as organic complexes. A second series of tests was performed involving single-step leaching with dilute acids and various operating parameters, including acid type, acid concentration, acid/coal contact time and coal particle size. For select samples, additional tests were performed to understand the results of leaching, including float-sink density separations and humic acid extraction. The results have shown that the majority of REE in Fort Union lignites appear to be associated weakly with the organic matrix of the coals, most likely as coordination complexes of carboxylic acid groups. The light REE and heavy REE exhibit different behaviors, however. The extractable light REE appear to have association both in acid-soluble mineral forms and as organic complexes, whereas the extractable heavy REE appear to be almost solely associated with the organics. In conclusion, scandium behavior was notably different than yttrium and the lanthanides, and the data suggests the extractable content is primarily associated as acid-soluble mineral forms.« less

Leaching behavior of rare earth elements in fort union lignite coals of North America

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

Laudal, Daniel A.; Benson, Steven A.; Addleman, Raymond Shane

Fort Union lignite coal samples were subjected to a series of aqueous leaching experiments to understand the extraction behavior of the rare earth elements (REE). This testing was aimed at understanding the modes of occurrence of the REE in the lignite coals, as well as to provide foundational data for development of rare earth extraction processes. In a first series of tests, a sequential leaching process was used to investigate modes of occurrence of the REE of select lignite coals. The tests involved sequential exposure to solvents consisting of water, ammonium acetate and dilute hydrochloric acid (HCl). The results indicatedmore » that water and ammonium acetate extracted very little of the REE, indicating the REE are not present as water soluble or ion-exchangeable forms. However, the data shows that a large percentage of the REE were extracted with the hydrochloric acid (80–95 wt%), suggesting presence in HCl-soluble mineral forms such as carbonates, and/or presence as organic complexes. A second series of tests was performed involving single-step leaching with dilute acids and various operating parameters, including acid type, acid concentration, acid/coal contact time and coal particle size. For select samples, additional tests were performed to understand the results of leaching, including float-sink density separations and humic acid extraction. The results have shown that the majority of REE in Fort Union lignites appear to be associated weakly with the organic matrix of the coals, most likely as coordination complexes of carboxylic acid groups. The light REE and heavy REE exhibit different behaviors, however. The extractable light REE appear to have association both in acid-soluble mineral forms and as organic complexes, whereas the extractable heavy REE appear to be almost solely associated with the organics. In conclusion, scandium behavior was notably different than yttrium and the lanthanides, and the data suggests the extractable content is primarily associated as acid-soluble mineral forms.« less

Microbial communities from different subsystems in biological heap leaching system play different roles in iron and sulfur metabolisms.

PubMed

Xiao, Yunhua; Liu, Xueduan; Ma, Liyuan; Liang, Yili; Niu, Jiaojiao; Gu, Yabing; Zhang, Xian; Hao, Xiaodong; Dong, Weiling; She, Siyuan; Yin, Huaqun

2016-08-01

The microbial communities are important for minerals decomposition in biological heap leaching system. However, the differentiation and relationship of composition and function of microbial communities between leaching heap (LH) and leaching solution (LS) are still unclear. In this study, 16S rRNA gene sequencing was used to assess the microbial communities from the two subsystems in ZiJinShan copper mine (Fujian province, China). Results of PCoA and dissimilarity test showed that microbial communities in LH samples were significantly different from those in LS samples. The dominant genera of LH was Acidithiobacillus (57.2 ∼ 87.9 %), while Leptospirillum (48.6 ∼ 73.7 %) was predominant in LS. Environmental parameters (especially pH) were the major factors to influence the composition and structure of microbial community by analysis of Mantel tests. Results of functional test showed that microbial communities in LH utilized sodium thiosulfate more quickly and utilized ferrous sulfate more slowly than those in LS, which further indicated that the most sulfur-oxidizing processes of bioleaching took place in LH and the most iron-oxidizing processes were in LS. Further study found that microbial communities in LH had stronger pyrite leaching ability, and iron extraction efficiency was significantly positively correlated with Acidithiobacillus (dominated in LH), which suggested that higher abundance ratio of sulfur-oxidizing microbes might in favor of minerals decomposition. Finally, a conceptual model was designed through the above results to better exhibit the sulfur and iron metabolism in bioleaching systems.

Immobilization of antimony in waste-to-energy bottom ash by addition of calcium and iron containing additives.

PubMed

Van Caneghem, Jo; Verbinnen, Bram; Cornelis, Geert; de Wijs, Joost; Mulder, Rob; Billen, Pieter; Vandecasteele, Carlo

2016-08-01

The leaching of Sb from waste-to-energy (WtE) bottom ash (BA) often exceeds the Dutch limit value of 0.32mgkg(-1) for recycling of BA in open construction applications. From the immobilization mechanisms described in the literature, it could be concluded that both Ca and Fe play an important role in the immobilization of Sb in WtE BA. Therefore, Ca and Fe containing compounds were added to the samples of the sand fraction of WtE BA, which in contrast to the granulate fraction is not recyclable to date, and the effect on the Sb leaching was studied by means of batch leaching tests. Results showed that addition of 0.5 and 2.5% CaO, 5% CaCl2, 2.5% Fe2(SO4)3 and 1% FeCl3 decreased the Sb leaching from 0.62±0.02mgkgDM(-1) to 0.20±0.02, 0.083±0.044, 0.25±0.01, 0.27±0.002 and 0.29±0.02mgkgDM(-1), respectively. Due to the increase in pH from 11.41 to 12.53 when 2.5% CaO was added, Pb and Zn leaching increased and exceeded the respective leaching limits. Addition of 5% CaCO3 had almost no effect on the Sb leaching, as evidenced by the resulting 0.53mgkgDM(-1) leaching concentration. This paper shows a complementary enhancement of the effect of Ca and Fe, by comparing the aforementioned Sb leaching results with those of WtE BA with combined addition of 2.5% CaO or 5% CaCl2 with 2.5% Fe2(SO4)3 or 1% FeCl3. These lab scale results suggest that formation of romeites with a high Ca content and formation of iron antimonate (tripuhyite) with a very low solubility are the main immobilization mechanisms of Sb in WtE BA. Besides the pure compounds and their mixtures, also addition of 10% of two Ca and Fe containing residues of the steel industry, hereafter referred to as R1 and R2, was effective in decreasing the Sb leaching from WtE BA below the Dutch limit value for reuse in open construction applications. To evaluate the long term effect of the additives, pilot plots of WtE BA with 10% of R1 and 5% and 10% of R2 were built and samples were submitted to leaching tests at regular intervals over time. The Sb leaching from untreated WtE BA was just below or above the Dutch limit value. The Sb leaching from the pilot plots of BA with additives first remained stable around 0.13mgkg(-1) but had a tendency to slightly increase after 6months, indicating the need for further research on the effect of weathering, and more specifically of carbonation, on Sb leaching from WtE BA. Copyright © 2016 Elsevier Ltd. All rights reserved.

In Situ Determination of Butyltin Release Rates from Antifouling Coatings on Navy Test Ships

DTIC Science & Technology

1985-07-01

formulations of antifouling paints containing tributyltin oxide. RESULTS 2Measured leach rates ranged from a high of 3.2 pg TBT /cm /days The SPC- 254... tributyltin in leachate determined by the hydride-AAS technique. DBT Total Sn Paint System/Ship or Panel MBT (percent) TBT (pg/L) ABC-2/MEYERKORD (Aug 84) NH...DDFR 43 4JNMwQWSfPM EXECUTIVE SUMMARY OBJECTIVE Determine in situ leach rates of tributyltin on the hulls of three Navy test ships coated with different

Catastrophe optics of sharp-edge diffraction.

PubMed

Borghi, Riccardo

2016-07-01

A classical problem of diffraction theory, namely plane wave diffraction by sharp-edge apertures, is here reformulated from the viewpoint of the fairly new subject of catastrophe optics. On using purely geometrical arguments, properly embedded into a wave optics context, uniform analytical estimates of the diffracted wavefield at points close to fold caustics are obtained, within paraxial approximation, in terms of the Airy function and its first derivative. Diffraction from parabolic apertures is proposed to test reliability and accuracy of our theoretical predictions.

Electrochemical thinning of silicon

DOEpatents

Medernach, John W.

1994-01-01

Porous semiconducting material, e.g. silicon, is formed by electrochemical treatment of a specimen in hydrofluoric acid, using the specimen as anode. Before the treatment, the specimen can be masked. The porous material is then etched with a caustic solution or is oxidized, depending of the kind of structure desired, e.g. a thinned specimen, a specimen, a patterned thinned specimen, a specimen with insulated electrical conduits, and so on. Thinned silicon specimen can be subjected to tests, such as measurement of interstitial oxygen by Fourier transform infra-red spectroscopy (FTIR).

Composition of CBRN Decontamination Effluent and Development of Surrogate Mixtures for Testing Effluent Treatment Technologies

DTIC Science & Technology

2016-07-01

possible, the site around the wash stations is graded to allow the wash water to run off to a pit, where it can seep into the earth or be collected...Caustic soda solution Radioisotopes /Nuclear Residuals Soap with warm water DS2 = Decontamination Solution 2 STB = Super Tropical bleach HTH = High... DATE (DD-MM-YYYY) 2. REPORT TYPE 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER

Tooele Army Depot - South Area Suspected Release Units. RCRA Facility Investigation - Phase 2, for SWMUs 1, 25, and 27

DTIC Science & Technology

1995-11-01

Thickener (25% naphthenic acids) (25% oleic acid) Source: NUS 1987, Departments of the Army and Air Force 1963 2-8 TOO/TBL0025 07/21/94 11:45 am bpw S-60...Assessment does not state whether incineration occurred at SWMU 1 or elsewhere. The AC containers were decontaminated at SWMU 1 by rinsing with caustic ... caustic decontaminating agents that may have been applied during disposal. Decontaminating agents used include DANC (a mixture of sodium hydroxide and

Comparative study on the selective chalcopyrite bioleaching of a molybdenite concentrate with mesophilic and thermophilic bacteria.

PubMed

Romano, P; Blázquez, M L; Alguacil, F J; Muñoz, J A; Ballester, A; González, F

2001-03-01

This study evaluates different bioleaching treatments of a molybdenite concentrate using mesophilic and thermophilic bacterial cultures. Further studies on the chemical leaching and the electrochemical behavior of the MoS(2) concentrate were carried out. Bioleaching tests showed a progressive removal of chalcopyrite from the molybdenite concentrate with an increase in temperature. Chemical leaching tests support the idea of an indirect attack of the concentrate. Electrochemical tests indicate that chalcopyrite dissolution is favored when molybdenite is present. Therefore, this type of bioleaching treatment could be applied to purify molybdenite flotation concentrates by selectively dissolving chalcopyrite.

Weatherability and Leach Resistance of Wood Impregnated with Nano-Zinc Oxide

NASA Astrophysics Data System (ADS)

Clausen, Carol A.; Green, Frederick; Nami Kartal, S.

2010-09-01

Southern pine specimens vacuum-treated with nano-zinc oxide (nano-ZnO) dispersions were evaluated for leach resistance and UV protection. Virtually, no leaching occurred in any of the nano-ZnO-treated specimens in a laboratory leach test, even at the highest retention of 13 kg/m3. However, specimens treated with high concentrations of nano-ZnO showed 58-65% chemical depletion after 12 months of outdoor exposure. Protection from UV damage after 12 months exposure is visibly obvious on both exposed and unexposed surfaces compared to untreated controls. Graying was markedly diminished, although checking occurred in all specimens. Nano-zinc oxide treatment at a concentration of 2.5% or greater provided substantial resistance to water absorption following 12 months of outdoor exposure compared to untreated and unweathered southern pine. We conclude that nano-zinc oxide can be utilized in new wood preservative formulations to impart resistance to leaching, water absorption and UV damage of wood.