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Sample records for metal hydroxide waste

  1. Characteristics of Cement Solidification of Metal Hydroxide Waste

    Directory of Open Access Journals (Sweden)

    Dae-Seo Koo

    2017-02-01

    Full Text Available To perform the permanent disposal of metal hydroxide waste from electro-kinetic decontamination, it is necessary to secure the technology for its solidification. The integrity tests on the fabricated solidification should also meet the criteria of the Korea Radioactive Waste Agency. We carried out the solidification of metal hydroxide waste using cement solidification. The integrity tests such as the compressive strength, immersion, leach, and irradiation tests on the fabricated cement solidifications were performed. It was also confirmed that these requirements of the criteria of Korea Radioactive Waste Agency on these cement solidifications were met. The microstructures of all the cement solidifications were analyzed and discussed.

  2. Characteristics of cement solidification of metal hydroxide waste

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Dae Seo; Sung, Hyun Hee; Kim, Seung Soo; Kim, Gye Nam; Choi, Jong Won [Dept. of Decontemination Decommission Technology Development, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-02-15

    To perform the permanent disposal of metal hydroxide waste from electro-kinetic decontamination, it is necessary to secure the technology for its solidification. The integrity tests on the fabricated solidification should also meet the criteria of the Korea Radioactive Waste Agency. We carried out the solidification of metal hydroxide waste using cement solidification. The integrity tests such as the compressive strength, immersion, leach, and irradiation tests on the fabricated cement solidifications were performed. It was also confirmed that these requirements of the criteria of Korea Radioactive Waste Agency on these cement solidifications were met. The microstructures of all the cement solidifications were analyzed and discussed.

  3. Pore size distribution, strength, and microstructure of portland cement paste containing metal hydroxide waste

    Energy Technology Data Exchange (ETDEWEB)

    Majid, Z.A.; Mahmud, H.; Shaaban, M.G.

    1996-12-31

    Stabilization/solidification of hazardous wastes is used to convert hazardous metal hydroxide waste sludge into a solid mass with better handling properties. This study investigated the pore size development of ordinary portland cement pastes containing metal hydroxide waste sludge and rice husk ash using mercury intrusion porosimetry. The effects of acre and the addition of rice husk ash on pore size development and strength were studied. It was found that the pore structures of mixes changed significantly with curing acre. The pore size shifted from 1,204 to 324 {angstrom} for 3-day old cement paste, and from 956 to 263 {angstrom} for a 7-day old sample. A reduction in pore size distribution for different curing ages was also observed in the other mixtures. From this limited study, no conclusion could be made as to any correlation between strength development and porosity. 10 refs., 6 figs., 3 tabs.

  4. Waste metal hydroxide sludge as adsorbent for a reactive dye.

    Science.gov (United States)

    Santos, Sílvia C R; Vílar, Vítor J P; Boaventura, Rui A R

    2008-05-30

    An industrial waste sludge mainly composed by metal hydroxides was used as a low-cost adsorbent for removing a reactive textile dye (Remazol Brilliant Blue) in solution. Characterization of this waste material included chemical composition, pH(ZPC) determination, particle size distribution, physical textural properties and metals mobility under different pH conditions. Dye adsorption equilibrium isotherms were determined at 25 and 35 degrees C and pH of 4, 7 and 10 revealing reasonably fits to Langmuir and Freundlich models. At 25 degrees C and pH 7, Langmuir fit indicates a maximum adsorption capacity of 91.0mg/g. An adsorptive ion-exchange mechanism was identified from desorption studies. Batch kinetic experiments were also conducted at different initial dye concentration, temperature, adsorbent dosage and pH. A pseudo-second-order model showed good agreement with experimental data. LDF approximation model was used to estimate homogeneous solid diffusion coefficients and the effective pore diffusivities. Additionally, a simulated real effluent containing the selected dye, salts and dyeing auxiliary chemicals, was also used in equilibrium and kinetic experiments and the adsorption performance was compared with aqueous dye solutions.

  5. Alkali metal and alkali metal hydroxide intercalates of the layered transition metal disulfides

    International Nuclear Information System (INIS)

    Kanzaki, Y.; Konuma, M.; Matsumoto, O.

    1981-01-01

    The intercalation reaction of some layered transition metal disulfides with alkali metals, alkali metal hydroxides, and tetraalkylammonium hydroxides were investigated. The alkali metal intercalates were prepared in the respective metal-hexamethylphosphoric triamide solutions in vaccuo, and the hydroxide intercalates in aqueous hydroxide solutions. According to the intercalation reaction, the c-lattice parameter was increased, and the increase indicated the expansion of the interlayer distance. In the case of alkali metal intercalates, the expansion of the interlayer distance increased continuously, corresponding to the atomic radius of the alkali metal. On the other hand, the hydroxide intercalates showed discrete expansion corresponding to the effective ionic radius of the intercalated cation. All intercalates of TaS 2 amd NbS 2 were superconductors. The expansion of the interlayer distance tended to increase the superconducting transition temperature in the intercalates of TaS 2 and vice versa in those of NbS 2 . (orig.)

  6. Polysulfide intercalated layered double hydroxides for metal capture applications

    Energy Technology Data Exchange (ETDEWEB)

    Kanatzidis, Mercouri G.; Ma, Shulan

    2017-04-04

    Polysulfide intercalated layered double hydroxides and methods for their use in vapor and liquid-phase metal capture applications are provided. The layered double hydroxides comprise a plurality of positively charged host layers of mixed metal hydroxides separated by interlayer spaces. Polysulfide anions are intercalated in the interlayer spaces.

  7. Synthesis of hydroxide type sorbents from industry high-iron wastes

    International Nuclear Information System (INIS)

    Stepanenko, E.K.; Smirnov, A.L.

    1986-01-01

    Article presents the results of studies on possibility of using of technological iron containing wastes for the obtaining of hydroxide type sorbents in granular form. The scheme of technology of synthesis of hydroxide type sorbents from high-iron wastes is elaborated.

  8. Analysis of Heavy Metal in Electrocoagulated Metal Hydroxide Sludge (EMHS from the Textile Industry by Energy Dispersive X-Ray Fluorescence (EDXRF

    Directory of Open Access Journals (Sweden)

    Tanveer Mehedi Adyel

    2012-12-01

    Full Text Available Environmental pollution due to discharges of heavy metal containing sludge from textile industries is a common nuisance in Bangladesh, where no treatment of sludge is carried out before final disposals. Energy Dispersive X-ray Fluorescence (EDXRF was employed in the present study to analyze the heavy metal content of Electrocoagulated Metal Hydroxide Sludge (EMHS collected from a composite textile industry. Thirteen heavy metals, viz., Mn, Ti, Cu, Zn, Ni, Sr, V, Cr, Zr, Hg, Cd, Nb and Ga, were detected. Mn, Ni, Cu, Zn and Cd exceeded the permissible limit to apply the EMHS in agricultural land. Cr, Ni, Cu and Zn were compared to the values of the European legislation to evaluate the environmental risk and to classify the wastes as inert wastes or as wastes that have to be control landfilled. EMHS was categorized as class I and needs to be deposited in controlled landfills.

  9. Method of electrolytically decontaminating of radioactive metal wastes

    International Nuclear Information System (INIS)

    Oonuma, Tsutomu; Tanaka, Akio; Yamadera, Toshio.

    1985-01-01

    Purpose: To significantly reduce the volume of secondary wastes by separating from electrolytes metal ions containing radioactive metal ions dissolved therein in the form of elemental metals of a reduced volume with ease, as well as regenerating the electrolytes for re-use. Method: Contaminated portions at the surface of the radioactive metal wastes are dissolved in electrolytes and, when the metal ion concentration in the electrolytes reaches a predetermined level, the electrolytes are introduced to an acid recovery step and an electrodeposition step. The recovered acid is re-used as the electrolytes, while dissolved metal ions containing radioactive metal ions are deposited as elemental metals in the electrodeposition step. The electrolytes usable herein include those acids easily forming stable complex compounds with the metals or those not forming hydroxides of the contaminated metals. Combination of sodium sulfate and sulfuric acid, sodium chloride and hydrochloride or the like is preferred. (Kamimura, M.)

  10. Heavy metals in municipal solid waste deposits

    Energy Technology Data Exchange (ETDEWEB)

    Flyhammar, P.

    1997-12-01

    Extensive use of heavy metals in modern society influences routes followed by fluxes on the surface of the Earth. The changed flow paths may be harmful for the balance of biological systems at different levels, micro-organisms, human beings and whole ecosystems, since the toxicity of heavy metals is determined by their concentrations and chemical forms. Despite the low mobility of heavy metals (Zn, Cu, Pb, Cr, Ni and Cd) in municipal landfills, it was found that extensive transformations of the binding forms of heavy metal take place within the waste mass during the degradation of the waste. These changes appear to be closely related to the development of early diagenetic solid phases, i.e. new secondary solid phases formed in the waste. The heavy metals often constitute a minor part of these phases and the bindings include several forms such as adsorption, complexation, coprecipitation, precipitation, etc. It was also found that the associations between heavy metals and solid phases are dominated by several binding forms to one specific substrate rather than bindings to various solid phases. The mobility of iron and manganese seems to increase during the processes involved in waste degradation due to the solution of oxide/hydroxide phases, while the heavy metals appear to become less mobile due to their binding to organic compounds and sulphides. However, one exception in this case may be nickel. Another aspect of the transformation of heavy metals is the accumulation of pools of heavy metals which can become susceptible to environmental changes, such as oxidation or acidification. However, the risk of increased mobilization caused by lower pH values seem to be limited since municipal solid waste has a large buffer capacity. 66 refs, 9 figs, 3 tabs 66 refs, 9 figs, 3 tabs

  11. Management of metal-bearing industrial solid waste by stabilization/solidification process

    Energy Technology Data Exchange (ETDEWEB)

    Sunitha, C.; Palanivelu, K. [Anna University, Chennai (India). Centre for Environmental Studies

    2005-07-01

    Metal-bearing sludge from an electroplating industry was immobilised by the solidification stabilisation treatment method. Reduction of the leachability of metals from the waste was studied in different combinations of waste and additives - cement, lime and fly ash. The study revealed that the optimum proportion for cement: metal hydroxide sludge: fly ash as 1:2:2 is the best. The encapsulation efficiency calculated for the metals such as Cu, Cr, Ni, Pb, and Zn was above 92%. The unconfined compressive strength (UCS) for the developed block was found to be 11.5 kg/cm{sup 2} after curing. The toxicity characteristic leach test (TCLP) test reveals that the heavy metal content in the leachate was well below the maximum permissible limit of WHO drinking water standard. 10 refs., 6 tabs.

  12. Process for the disposal of alkali metals

    International Nuclear Information System (INIS)

    Lewis, L.C.

    1979-01-01

    The invention describes a method of disposing of alkali metals by forming a solid waste for storage. The method comprises preparing an aqueous disposal solution of at least 55 weight percent alkali metal hydroxide, heating the alkali metal to melting temperature to form a feed solution, and spraying the molten feed solution into the disposal solution. The alkali metal reacts with the water in the disposal solution in a controlled reaction which produces alkali metal hydroxide, hydrogen and heat and thereby forms a solution of alkali metal hydroxides. Water is added to the solution in amounts sufficient to maintain the concentration of alkali metal hydroxides in the solution at 70 to 90 weight percent, and to maintain the temperature of the solution at about the boiling point. Removing and cooling the alkali metal hydroxide solution thereby forms a solid waste for storage. The method is particularly applicable to radioactive alkali metal reactor coolant. (auth)

  13. Ion Recognition Approach to Volume Reduction of Alkaline Tank Waste by Separation and Recycle of Sodium Hydroxide and Sodium Nitrate

    International Nuclear Information System (INIS)

    Moyer, Bruce A.; Marchand, Alan P.; Bonnesen, Peter V.; Bryan, Jeffrey C.; Haverlock, Tamara J.

    2004-01-01

    This research was intended to provide the scientific foundation upon which the feasibility of liquid-liquid extraction chemistry for bulk reduction of the volume of high-activity tank waste can be evaluated. Primary focus has been on sodium hydroxide separation, with potential Hanford application. Value in sodium hydroxide separation can potentially be found in alternative flowsheets for treatment and disposal of low-activity salt waste. Additional value can be expected in recycle of sodium hydroxide for use in waste retrieval and sludge washing, whereupon additions of fresh sodium hydroxide to the waste can be avoided. Potential savings are large both because of the huge cost of vitrification of the low-activity waste stream and because volume reduction of high-activity wastes could obviate construction of costly new tanks. Toward these ends, the conceptual development begun in the original proposal was extended with the formulation of eight fundamental approaches that could be undertaken for extraction of sodium hydroxide

  14. Structural Differentiation between Layered Single (Ni) and Double Metal Hydroxides (Ni–Al LDHs) Using Wavelet Transformation

    Energy Technology Data Exchange (ETDEWEB)

    Siebecker, Matthew G. [University of Delaware, Delaware Environmental Institute; Sparks, Donald L. [University of Delaware, Delaware Environmental Institute

    2017-09-07

    Layered double hydroxides (LDHs) are anionic clays important in disciplines such as environmental chemistry, geochemistry, and materials science. Developments in signal processing of extended X-ray absorption fine structure (EXAFS) data, such as wavelet transformation (WT), have been used to identify transition metals and Al present in the hydroxide sheets of LDHs. The WT plots of LDHs should be distinct from those of isostructural single metal hydroxides. However, no direct comparison of these minerals appears in the literature using WT. This work systematically analyzes a suite of Ni-rich mineral standards, including Ni–Al LDHs, single metal Ni hydroxides, and Ni-rich silicates using WT. The results illustrate that the WT plots for α-Ni(OH)2 and Ni–Al LDHs are often indistinguishable from each other, with similar two-component plots for the different mineral types. This demonstrates that the WT of the first metal shell often cannot be used to differentiate an LDH from a single metal hydroxide. Interlayer anions adsorbed to the hydroxide sheet of α-Ni(OH)2 affect the EXAFS spectra and are not visible in the FT but are clearly resolved and discrete in the WT.

  15. Production of calcium hydroxide from the waste of Cariri stone

    International Nuclear Information System (INIS)

    Alves, T.M.E.; Santos, A.M.M.; Brasileiro, M.I.; Pinheiro, S.F.L.; Prado, A.C.A.

    2016-01-01

    The extraction of Cariri stone in the northeast is a frequent activity because of its ornamental application as well as for the construction sector. However, by this extraction, untapped waste formation grows and becomes a problem for the environment. The objective of this work is to produce calcium hydroxide, from this limestone residue, with controlled porosity, solubility and particle size. The waste was characterized with X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF) and thermal analysis (TGA). The limestone was calcined at 850°C and 950°C for 45 minutes and three hours, being characterized by XRD, XRF and TGA. Once calcined, it was hydrated with 17,5g and 22g oxide to 100mL water and manually mixed for 15 and 25 minutes. The calcium hydroxides have been submitted for tests in vivo in rats and will be characterized by XRD, Scanning Electron Microscopy (SEM) and Infrared. (author)

  16. Microwave-assisted synthesis of metal oxide/hydroxide composite electrodes for high power supercapacitors - A review

    Science.gov (United States)

    Faraji, Soheila; Ani, Farid Nasir

    2014-10-01

    Electrochemical capacitors (ECs), also known as pseudocapacitors or supercapacitors (SCs), is receiving great attention for its potential applications in electric and hybrid electric vehicles because of their ability to store energy, alongside with the advantage of delivering the stored energy much more rapidly than batteries, namely power density. To become primary devices for power supply, supercapacitors must be developed further to improve their ability to deliver high energy and power simultaneously. In this concern, a lot of effort is devoted to the investigation of pseudocapacitive transition-metal-based oxides/hydroxides such as ruthenium oxide, manganese oxide, cobalt oxide, nickel oxide, cobalt hydroxide, nickel hydroxide, and mixed metal oxides/hydroxides such as nickel cobaltite and nickel-cobalt oxy-hydroxides. This is mainly due to the fact that they can produce much higher specific capacitances than typical carbon-based electric double-layer capacitors and electronically conducting polymers. This review presents supercapacitor performance data of metal oxide thin film electrodes by microwave-assisted as an inexpensive, quick and versatile technique. Supercapacitors have established the specific capacitance (Cs) principles, therefore, it is likely that metal oxide films will continue to play a major role in supercapacitor technology and are expected to considerably increase the capabilities of these devices in near future.

  17. Application of magnesium hydroxide and barium hydroxide for the ...

    African Journals Online (AJOL)

    Application of magnesium hydroxide and barium hydroxide for the removal of metals and sulphate from mine water. ... equivalent to the Ba(OH)2 dosage. During CO2-dosing, CaCO3 is precipitated to the saturation level of CaCO3. Keywords: Magnesium hydroxide; barium hydroxide; sulphate removal; water treatment ...

  18. Method of disposing radioactive wastes

    International Nuclear Information System (INIS)

    Isozaki, Kei.

    1983-01-01

    Purpose : To enable safety ocean disposal of radioactive wastes by decreasing the leaching rate of radioactive nucleides, improving the quick-curing nature and increasing the durability. Method : A mixture comprising 2 - 20 parts by weight of alkali metal hydroxide and 100 parts by weight of finely powdered aqueous slags from a blast furnace is added to radioactive wastes to solidify them. In the case of medium or low level radioactive wastes, the solidification agent is added by 200 parts by weight to 100 parts by weight of the wastes and, in the case of high level wastes, the solidification agent is added in such an amount that the wastes occupy about 20% by weight in the total of the wastes and the solidification agent. Sodium hydroxide used as the alkali metal hydroxide is partially replaced with sodium carbonate, a water-reducing agent such as lignin sulfonate is added to improve the fluidity and suppress the leaching rate and the wastes are solidified in a drum can. In this way, corrosions of the vessel can be suppressed by the alkaline nature and the compression strength, heat stability and the like of the product also become excellent. (Sekiya, K.)

  19. Effect of uniaxially pressing ordinary Portland cement pastes containing metal hydroxides on porosity, density, and leaching

    International Nuclear Information System (INIS)

    Cheeseman, C.R.; Asavapisit, S.; Knight, J.

    1998-01-01

    Synthetic metal hydroxide wastes containing Zn and Pb have been mixed with partially hydrated cement and uniaxially pressed. The effect on porosity, pore size distribution, and bulk and skeletal densities has been characterized using mercury intrusion porosimetry. Ca(OH) 2 formation has been determined using differential thermal analysis and metal leaching has been assessed in a series of static leach tests completed on monolithic samples. Pressed solidified materials have increased density, reduced porosity, and reduced Ca(OH) 2 . They exhibit increased resistance to acid attack in terms of sample weight loss during leaching due to reduced release of alkalis. Leaching of Zn and Pb is primarily determined by pH. A peak observed in Zn leaching from pressed samples is due to the effect of changing leachate pH on the dominant Zn species present

  20. Technical basis for a minimum hydroxide concentration in tanks containing dilute waste

    International Nuclear Information System (INIS)

    Zapp, P.E.

    1995-05-01

    Laboratory tests were performed to address the protection of waste tank steel from corrosion in situations of elevated temperatures up to 75 C (hot spots) in the sludge layer of Extended Sludge Processing (ESP) tanks. Coupon immersion tests were conducted at 75 C in two ESP simulants at four hydroxide (or pH) levels. The nitrite concentrations of the simulants were calculated from the ESP technical standards based on a temperature of 40 C. The results showed that a hydroxide concentration of at least 0.01 M prevented significant corrosion of the steel at the elevated temperature. This conclusion provides the technical basis for the revised minimum hydroxide concentration of 0.01 M in the draft WSRC 241-82H Control Room Process Requirements, for the ESP tanks

  1. Layered Metal Hydroxides Containing Calcium and Their Structural Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Hyun; Heo, Il; Lee, Sung Han; Oh, Jae Min [College of Science and Technology, Yonsei University, Wonju (Korea, Republic of); Paek, Seung Min [Kyungpook National University, Daegu (Korea, Republic of); Park, Chung Berm; Choi, Ae Jin [National Institute of Horticultural and Herbal Science of R and D Eumseong (Korea, Republic of); Choy, Jin Ho [Ewha Womans University, Seoul (Korea, Republic of)

    2012-06-15

    Layered metal hydroxides (LMHs) containing calcium were synthesized by coprecipitation in solution having two different trivalent metal ions, iron and aluminum. Two mixed metal solutions (Ca{sup 2+}/Al{sup 3+} and Ca{sup 2+}/Fe{sup 3+} = 2/1) were added to sodium hydroxide solution and the final pH was adjusted to {approx}11.5 and {approx}13 for CaAl-and CaFe-LMHs. Powder X-ray diffraction (XRD) for the two LMH samples showed well developed (00l) diffractions indicating 2-dimensional crystal structure of the synthesized LMHs. Rietveld refinement of the X-ray diffraction pattern, the local structure analysis through X-ray absorption spectroscopy, and thermal analysis also confirmed that the synthesized precipitates show typical structure of LMHs. The chemical formulae, Ca{sub 2.04}Al{sub 1}(OH){sub 6}(NO{sub 3}){center_dot}5.25H{sub 2}O and Ca{sub 2.01}Fe{sub 1}(OH){sub 6}(NO{sub 3}){center_dot}4.75H{sub 2}O were determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Particle morphology and thermal behavior for the synthesized LMHs were examined by field emission scanning electron microscopy and thermogravimetric differential scanning calorimetry

  2. Study of sorption of platinum metals, gold and silver by phosphonium hydroxide antonite

    International Nuclear Information System (INIS)

    Khudaybergenov, U.; Tajibaev, D.; Yuldasheva, K.T.

    2002-01-01

    The aim of the work was to study and to use a phosphonium hydroxide anionite for concentrating of trace amounts of platinum metals, gold and silver from the mixed solutions composed of copper, nickel, cobalt, iron and zinc. The experiments were done using radionuclides of determined and interfered elements. Conditions for sorption concentrating of the noble metals by phosphonium hydroxide were determined by the selectivity of the phosphonium hydroxide to the noble metals from acid solutions. A noble metal sorption degree was observed from the experiments to be rather high at the acid concentration level of 0.1-0.5 M. At higher than 0.5 M acid concentration sorption activity decreased. With increase of chlorine acid-concentration sorption of palladium was observed to considerably decrease, while iridium sorption was increased. The latter fact can be caused by lowering of hydration of iridium ions. A considerable decrease of capability of the noble metal sorption from nitric acid solutions was observed. It is possible that HNO 3 anions are strongly bound with the anionite functional group. Thus, nitric acid reduces sorption of the noble metals in the following order: Ir>Ru>Pd>Pt>Os, and it does not have effect on the sorption activity of Au and Ag. Increase of H 2 SO 4 concentration in the solution has slightly reduced noble metal sorption activity. Copper, nickel, iron and other metals accompanying the noble metals, at concentration ratio of 1:1000 have resulted in decrease of sorption activity of the noble metals, although sorption of iridium was increased in the presence of copper, silver and nickel. We suggest that copper, silver and nickel have formed the complex functional compounds, which can probably undergo an anion exchange

  3. Sulfide oxidation and the natural attenuation of arsenic and trace metals in the waste rocks of the abandoned Seobo tungsten mine, Korea

    International Nuclear Information System (INIS)

    Lee, Pyeong-koo; Kang, Min-Ju; Choi, Sang-Hoon; Touray, Jean-Claude

    2005-01-01

    Mineralogical examinations were performed to characterize the formation of secondary minerals and natural removal process of dissolved As and trace metals (Pb, Zn and Cu) from sulfide oxidation. Laboratory-based leaching tests were also conducted to determine whether the concentrations of As and trace metals in the leachates from waste-rock materials and contaminated soil could be affected by the presence acids such as acid rainwater or acid mine drainage. Waste-rock materials and contaminated soil were compared by 4-day leaching tests using HNO 3 solutions of increasing acidity (0.00001-0.1mole/L). Mineralogical studies of the waste rocks confirmed the presence of Fe-(oxy)hydroxides (e.g. goethite), jarosite, elemental S, Fe-sulfates, amorphous Fe-As phases, anglesite and covellite as secondary minerals. These secondary minerals act as mineralogical scavengers of dissolved trace metals, SO 4 2- and acidity released by sulfide oxidation. Arsenic was attenuated by the adsorption on Fe-(oxy)hydroxides and/or the formation of an amorphous Fe-As phase, with a Fe/As ratio=1 (maybe scorodite: FeAsO 4 .2H 2 O). Electron probe microanalyses data showed that the Fe-(oxy)hydroxides had high concentrations of Pb (up to 21wt%), with appreciable amounts of As (up to 7.7wt%), Zn (up to 4.6wt%) and Cu (up to 2.5wt%) indicating that dissolved metals were co-precipitated and adsorbed onto Fe-(oxy)hydroxides, Fe(Mn)-hydroxides and Fe-sulfates. The results of the leaching experiments within the pH-range 3.5-5.0 indicated that acidic rainstorms may leach minor amounts of Pb (ca. 1.7-4.0% of total), Zn (ca. 0.8-2.2% of total), Cu (ca. 0.0-0.2% of total) and As (ca. 0.02-0.1% of total) from waste rocks, including the dissolution of soluble secondary minerals previously formed during prolonged dry periods, while dissolution of these elements was negligible from the contaminated soil. In the pH-range 1.0-3.0, the leaching of Pb (ca. 2.4-31% of total) and As (ca. 0.1-5.8% of total) from

  4. Two-dimensional metal oxide and metal hydroxide nanosheets: synthesis, controlled assembly and applications in energy conversion and storage

    NARCIS (Netherlands)

    ten Elshof, Johan E.; Yuan, H.; Gonzalez Rodriguez, P.

    2016-01-01

    The developments and state of the art in the research on two-dimensional nanosheets derived from layered metal oxides and layered metal hydroxides are reviewed in this paper, with emphasis on their promising applications in various new energy technologies, i.e., as supercapacitor electrodes, lithium

  5. Isotope exchange between alkaline earth metal hydroxide and HTO water in the equilibrium state

    International Nuclear Information System (INIS)

    Imaizumi, H.; Gounome, J.; Kano, N.

    1997-01-01

    In order reveal to what extent tritium ( 3 H or T) can be incorporated into hydroxides, the isotope exchange reaction (OT-for-OH exchange reaction) between each alkaline earth metal hydroxide (M(OH) 2 ), where M means alkaline earth metal (M=Ca, Sr or Ba) and HTO water was observed homogeneously at 30 deg C under equilibrium after mixing. Consequently, the followings were obtained: a quantitative relation between the electronegativity of each M ion and the ability (of the M ion) incorporating OT - into the M hydroxide can be found and the ability is small when the temperature is high, the exchange rate for the OT-for-OH exchange reaction is small when the electronegativity of the M ion in the M hydroxide is great, as for the dissociation of HTO water, it seems that formula (HTO ↔ T + + OH - ) is more predominant than the formula (HTO ↔H + + OT - ) when the temperature is high and the method used in this work is useful to estimate the reactivity of a certain alkaline material. (author)

  6. Quantitative chemical state XPS analysis of first row transition metals, oxides and hydroxides

    International Nuclear Information System (INIS)

    Biesinger, M C; Payne, B P; McIntryre, N S; Hart, B R; Lau, L Wm; Grosvenor, A P; Smart, R StC

    2008-01-01

    Practical quantitative chemical state X-ray photoelectron spectroscopy (XPS) analysis of first row transition metals, oxides and hydroxides is challenging due to the complexity of their M 2p spectra. Complex multiplet splitting, shake-up and plasmon loss structure can play a role in the interpretation of the chemical states present. This paper will show practical curve fitting procedures for the quantitative measurement of different chemical states for metal oxides and hydroxides from a survey of transition metals. It will also discuss some of the limitations and pitfalls present as well as give practical examples of their successful use. These curve-fitting procedures are based on 1) standard spectra from quality reference samples, 2) a survey of appropriate literature databases and/or a compilation of literature references, 3) fitting of multiplet split spectra based on spectra of numerous reference materials and theoretical modelling, 4) spectral subtractions routines, again using reference spectra, and 5) specific literature references where fitting procedures are available

  7. Quantitative chemical state XPS analysis of first row transition metals, oxides and hydroxides

    Energy Technology Data Exchange (ETDEWEB)

    Biesinger, M C; Payne, B P; McIntryre, N S [Department of Chemistry, University of Western Ontario, London, Ontario, N6A 5B7 (Canada); Hart, B R; Lau, L Wm [Surface Science Western, Room G1, Western Science Centre, University of Western Ontario, London, Ontario, N6A 5B7 (Canada); Grosvenor, A P [Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, T6G 2G2 (Canada); Smart, R StC [ACeSSS, Applied Centre for Structural and Synchrotron Studies, University of South Australia, Mawson Lakes, SA 5095 (Australia)], E-mail: biesingr@uwo.ca

    2008-03-15

    Practical quantitative chemical state X-ray photoelectron spectroscopy (XPS) analysis of first row transition metals, oxides and hydroxides is challenging due to the complexity of their M 2p spectra. Complex multiplet splitting, shake-up and plasmon loss structure can play a role in the interpretation of the chemical states present. This paper will show practical curve fitting procedures for the quantitative measurement of different chemical states for metal oxides and hydroxides from a survey of transition metals. It will also discuss some of the limitations and pitfalls present as well as give practical examples of their successful use. These curve-fitting procedures are based on 1) standard spectra from quality reference samples, 2) a survey of appropriate literature databases and/or a compilation of literature references, 3) fitting of multiplet split spectra based on spectra of numerous reference materials and theoretical modelling, 4) spectral subtractions routines, again using reference spectra, and 5) specific literature references where fitting procedures are available.

  8. Plasma methods for metals recovery from metal-containing waste.

    Science.gov (United States)

    Changming, Du; Chao, Shang; Gong, Xiangjie; Ting, Wang; Xiange, Wei

    2018-04-27

    Metal-containing waste, a kind of new wastes, has a great potential for recycling and is also difficult to deal with. Many countries pay more and more attention to develop the metal recovery process and equipment of this kind of waste as raw material, so as to solve the environmental pollution and comprehensively utilize the discarded metal resources. Plasma processing is an efficient and environmentally friendly way for metal-containing waste. This review mainly discuss various metal-containing waste types, such as printed circuit boards (PCBs), red mud, galvanic sludge, Zircon, aluminium dross and incinerated ash, and the corresponding plasma methods, which include DC extended transferred arc plasma reactor, DC non-transferred arc plasma torch, RF thermal plasma reactor and argon and argon-hydrogen plasma jets. In addition, the plasma arc melting technology has a better purification effect on the extraction of useful metals from metal-containing wastes, a great capacity of volume reduction of waste materials, and a low leaching toxicity of solid slag, which can also be used to deal with all kinds of metal waste materials, having a wide range of applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Literature survey on metal waste form for metallic waste from electrorefiners for the electrometallurgical treatment of spent metallic fuels

    International Nuclear Information System (INIS)

    Nishimura, Tomohiro

    2003-01-01

    This report summarizes the recent results of the metal waste form development activities at the Argonne National Laboratory in the USA for high-level radioactive metallic waste (stainless-steel (SS) cladding hulls, zirconium (Zr), noble-metal fission products (NMFPs), etc.) from electrorefiners for the electrometallurgical treatment of spent metallic fuels. Their main results are as follows: (1) SS- 15 wt.% Zr- ∼4 wt.% NMFPs alloy was selected as the metal waste form, (2) metallurgical data, properties, long-term corrosion data, etc. of the alloy have been collected, (3) 10-kg ingots have been produced in hot tests and a 60-kg production machine is under development. The following research should be made to show the feasibility of the metal waste form in Japan: (1) degradation assessment of the metal waste form in Japanese geological repository environments, and (2) clarification of the maximum allowable contents of NMFPs. (author)

  10. Method of processing nitrate-containing radioactive liquid wastes

    International Nuclear Information System (INIS)

    Ogawa, Norito; Nagase, Kiyoharu; Otsuka, Katsuyuki; Ouchi, Jin.

    1983-01-01

    Purpose: To efficiently concentrate nitrate-containing low level radioactive liquid wastes by electrolytically dialyzing radioactive liquid wastes to decompose the nitrate salt by using an electrolytic cell comprising three chambers having ion exchange membranes and anodes made of special materials. Method: Nitrate-containing low level radioactive liquid wastes are supplied to and electrolytically dialyzed in a central chamber of an electrolytic cell comprising three chambers having cationic exchange membranes and anionic exchange membranes made of flouro-polymer as partition membranes, whereby the nitrate is decomposed to form nitric acid in the anode chamber and alkali hydroxide compound or ammonium hydroxide in the cathode chamber, as well as concentrate the radioactive substance in the central chamber. Coated metals of at least one type of platinum metal is used as the anode for the electrolytic cell. This enables efficient industrial concentration of nitrate-containing low level radioactive liquid wastes. (Yoshihara, H.)

  11. One step bioconversion of waste precious metals into Serratia biofilm-immobilized catalyst for Cr(VI) reduction.

    Science.gov (United States)

    Yong, P; Liu, W; Zhang, Z; Beauregard, D; Johns, M L; Macaskie, L E

    2015-11-01

    For reduction of Cr(VI) the Pd-catalyst is excellent but costly. The objectives were to prove the robustness of a Serratia biofilm as a support for biogenic Pd-nanoparticles and to fabricate effective catalyst from precious metal waste. Nanoparticles (NPs) of palladium were immobilized on polyurethane reticulated foam and polypropylene supports via adhesive biofilm of a Serratia sp. The biofilm adhesion and cohesion strength were unaffected by palladization and catalytic biofilm integrity was also shown by magnetic resonance imaging. Biofilm-Pd and mixed precious metals on biofilm (biofilm-PM) reduced 5 mM Cr(VI) to Cr(III) when immobilized in a flow-through column reactor, at respective flow rates of 9 and 6 ml/h. The lower activity of the latter was attributed to fewer, larger, metal deposits on the bacteria. Activity was lost in each case at pH 7 but was restored by washing with 5 mM citrate solution or by exposure of columns to solution at pH 2, suggesting fouling by Cr(III) hydroxide product at neutral pH. A 'one pot' conversion of precious metal waste into new catalyst for waste decontamination was shown in a continuous flow system based on the use of Serratia biofilm to manufacture and support catalytic Pd-nanoparticles.

  12. Defining a metal-based waste form for IFR pyroprocessing wastes

    International Nuclear Information System (INIS)

    McDeavitt, S.M.; Park, J.Y.; Ackerman, J.P.

    1994-01-01

    Pyrochemical electrorefining to recover actinides from metal nuclear fuel is a key element of the Integral Fast Reactor (IFR) fuel cycle. The process separates the radioactive fission products from the long-lived actinides in a molten LiCl-KCl salt, and it generates a lower waste volume with significantly less long-term toxicity as compared to spent nuclear fuel. The process waste forms include a mineral-based waste form that will contain fission products removed from an electrolyte salt and a metal-based waste form that will contain metallic fission products and the fuel cladding and process materials. Two concepts for the metal-based waste form are being investigated: (1) encapsulating the metal constituents in a Cu-Al alloy and (2) alloying the metal constituents into a uniform stainless steel-based waste form. Results are given from our recent studies of these two concepts

  13. Tank waste chemistry: A new understanding of waste aging

    International Nuclear Information System (INIS)

    Babad, H.; Camaioni, D.M.; Lilga, M.A.; Samuels, W.D.; Strachan, D.M.

    1993-02-01

    There is concern about the risk of uncontrolled exothermic reactions(s) in Hanford Site waste tanks containing NO 3 minus /NO 2 minus based salts and/or metal hydroxide sludges in combination with organics or ferrocyanides. However, gradual oxidation of the waste in the tanks to less reactive species appears to have reduced the risk. In addition, wastes sampled to date contain sufficiently large quantities of water so that propagation reactions are highly unlikely. This report details an investigation into the risk of an uncontrolled exothermic reaction in Hanford Site high-activity water tanks

  14. Sorption of uranium by clinoptilolite modified by a some metals hydroxides

    International Nuclear Information System (INIS)

    Plotnikov, V.I.; Medvedeva, Z.V.; Zhabykbaev, G.T.

    2005-01-01

    In the present report the sorption character of uranium (IV) in the static conditions on the thin layer sorbents with application of the clinoptilolite of the Chankan deposit of the Republic of Kazakhstan is shown. A wide circle of metal hydroxides - in both the individual form and in the their mixture - is used. It is shown that the most sorptive capacity against the uranium (IV) has the modified clinoptilolite of MnO 2

  15. The metal-organic framework MIL-53(Al) constructed from multiple metal sources: alumina, aluminum hydroxide, and boehmite.

    Science.gov (United States)

    Li, Zehua; Wu, Yi-nan; Li, Jie; Zhang, Yiming; Zou, Xin; Li, Fengting

    2015-04-27

    Three aluminum compounds, namely alumina, aluminum hydroxide, and boehmite, are probed as the metal sources for the hydrothermal synthesis of a typical metal-organic framework MIL-53(Al). The process exhibits enhanced synthetic efficiency without the generation of strongly acidic byproducts. The time-course monitoring of conversion from different aluminum sources into MIL-53(Al) is achieved by multiple characterization that reveals a similar but differentiated crystallinity, porosity, and morphology relative to typical MIL-53(Al) prepared from water-soluble aluminum salts. Moreover, the prepared MIL-53(Al) constructed with the three insoluble aluminum sources exhibit an improved thermal stability of up to nearly 600 °C and enhanced yields. Alumina and boehmite are more preferable than aluminum hydroxide in terms of product porosity, yield, and reaction time. The adsorption performances of a typical environmental endocrine disruptor, dimethyl phthalate, on the prepared MIL-53(Al) samples are also investigated. The improved structural stability of MIL-53(Al) prepared from these alternative aluminum sources enables double-enhanced adsorption performance (up to 206 mg g(-1)) relative to the conventionally obtained MIL-53(Al). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Volumetric determination of hydroxide, aluminate, and carbonate in alkaline solutions of nuclear waste

    International Nuclear Information System (INIS)

    Baumann, E.W.

    1975-06-01

    An integrated procedure was developed for determining OH - , Al(OH) 4 - , and CO 3 2- in alkaline nuclear waste. The free alkali, the hydroxide released when Al(OH) 3 is complexed with oxalate, and the precipitated BaCO 3 were determined by acidimetric titration. With a 50-μl sample, the relative standard deviations were 1 to 2 percent for nonradioactive test solutions and 2 to 5 percent for radioactive process solutions. (U.S.)

  17. Single sheet metal oxides and hydroxides

    DEFF Research Database (Denmark)

    Huang, Lizhi

    The synthesis of layered double hydroxides (LDHs) provides a relatively easy and traditional way to build versatile chemical compounds with a rough control of the bulk structure. The delamination of LDHs to form their single host layers (2D nanosheets) and the capability to reassemble them offer......) Delamination of the LDHs structure (oxGRC12) with the formation of single sheet iron (hydr)oxide (SSI). (3) Assembly of the new 2D nanosheets layer by layer to achieve desired functionalities....

  18. Nuclear fuel cycle waste recycling technology deverlopment - Radioactive metal waste recycling technology development

    International Nuclear Information System (INIS)

    Oh, Won Zin; Moon, Jei Kwon; Jung, Chong Hun; Park, Sang Yoon

    1998-08-01

    With relation to recycling of the radioactive metal wastes which are generated during operation and decommissioning of nuclear facilities, the following were described in this report. 1. Analysis of the state of the art on the radioactive metal waste recycling technologies. 2. Economical assessment on the radioactive metal waste recycling. 3. Process development for radioactive metal waste recycling, A. Decontamination technologies for radioactive metal waste recycling. B. Decontamination waste treatment technologies, C. Residual radioactivity evaluation technologies. (author). 238 refs., 60 tabs., 79 figs

  19. Biodegradation of metal citrate complexes and implications for toxic-metal mobility

    International Nuclear Information System (INIS)

    Francis, A.J.; Dodge, C.J.; Gillow, J.B.

    1992-01-01

    The presence of synthetic and naturally occurring chelating agents in nuclear and toxic-metal wastes is a major concern because of their potential to enhance mobilization of metal ions away from the disposal sites. Of particular interest is citric acid, which is present in low-level and transuranic radioactive wastes and in domestic and industrial wastes (as washing fluids, for instance), as well as being found naturally. Citrate ions form multidentate, stable complexes with a variety of toxic metals and radionuclides; but biodegradation of these complexes, precipitating the metal ions as insoluble hydroxides, oxides or other salts, may retard migration. Here we report a study of the biodegradation of citrate complexes of Ca, Fe(II), Fe(III), Cd, Cu, Ni, Pb and U. Several of these complexes were not readily degraded by bacteria, and the biodegradability depended on the chemical nature of the complex, not on the toxicity of the metal to the bacteria. This resistance to biodegradation implies that citrate complexation may play an important part in migration of these hazardous wastes. (author)

  20. Influence of alkali metal hydroxides on corrosion of Zr-base alloys

    International Nuclear Information System (INIS)

    Jeong, Yong Hwan

    1996-01-01

    The influence of group-1 alkali hydroxides on different Zr-based alloys have been carried out in static autoclaves at 350 deg C in pressurized water, conditioned in low(0.32 mmol), medium(4.3 mmol) and high(31.5 mmol) equimolar concentration of Li-, Na-, K-, Rb- and Cs-hydroxide. Two types of alloys have been investigated: Zr-Sn-(TRM, Transition metal) and Zr-Sn-Nb-(TRM, Transition metal). From the experiments the cation could be identified as the responsible species for corrosion of Zr alloy in alkalized water. The radius of the cation governs the accelerated corrosion in the pre-transition region of Zr alloy. Incorporation of alkali cation into the zirconium oxide lattice is probably the mechanism which allows the corrosion enhancement for Li and Na and the significant lower effect for the other bases. Nb containing alloys showed lower corrosion resistance than Zr-Sn-TRM alloys in all alkali solutions. Both types of alloys were corroded significantly more in LiOH and NaOH than in the other alkali environments. Lowest corrosive aggressiveness has been found for CsOH followed by KOH. Concluding from the corrosion behavior in the different alkali environments and taking into account the tendency to accelerate the corrosion of Zr alloys, CsOH and KOH are possible alternate alkali for PWR (Pressurized Water Reactor) application. (author)

  1. Methods in the treatment of sodium wastes

    International Nuclear Information System (INIS)

    Rodriguez, G.

    1997-01-01

    In the domain of sodium waste processing, we have followed a logical route that has enabled us to propose a global method with respect to sodium wastes. This approach has led to: The choice of only those sodium processes using water; The development of sodium purification methods; The development of methods for cutting metallic wastes soiled by or filled with sodium; The transformation of the resulting sodium hydroxide into ultimate solid wastes for surface storage. (author)

  2. Chemical decontamination method for radioactive metal waste

    International Nuclear Information System (INIS)

    Onuma, Tsutomu; Akimoto, Hidetoshi

    1991-01-01

    The invention relates to a decontamination method for radioactive metal waste products derived from equipment that handles radioactive materials whose surfaces have been contaminated; in particular it concerns a decontamination method that reduces the amount of radioactive waste by decontaminating radioactive waste substances to a level of radioactivity in line with normal waste products. In order to apply chemical decontamination to metal waste products whose surfaces are divided into carbon steel waste and stainless steel waste; the carbon steel waste is treated using only a primary process in which the waste is immersed in a sulfuric acid solution, while the stainless steel waste must be treated with both the primary process and then electrolytically reduces it for a specific length of time and a secondary process that uses a solution of sulfuric acid mixed with oxidizing metal salts. The method used to categorize metal waste into carbon steel waste and stainless steel waste involves determining the presence, or absence, of magnetism. Voltage is applied for a fixed duration; once that has stopped, electrolytic reduction repeats the operative cycle of applying, then stopping voltage until the potential of the radioactive metal waste is retained in the active region. 1 fig. 2 tabs

  3. [Determination of total mass and morphology analysis of heavy metal in soil with potassium biphthalate-sodium hydroxide by ICP-AES].

    Science.gov (United States)

    Qu, Jiao; Yuan, Xing; Cong, Qiao; Wang, Shuang

    2008-11-01

    Blank soil was used as quality controlling samples, soil sample dealt by potassium biphthalate-sodium hydroxide buffer solution was used as check sample, mixed acid HNO3-HF-HClO4 was chosen to nitrify soil samples, and plasma emission spectrometer (ICP-AES) was used as detecting method. The authors determined the total metal mass of Mo, Pb, As, Hg, Cr, Cd, Zn, Cu and Ni in the extracted and dealt soil samples, and determined the mass of Mo, Pb, As, Hg, Cr, Cd, Zn, Cu and Ni in the three chemical morphologies, including acid extractable morphology, oxide associated morphology, and organics associated modality. The experimental results indicated that the different pH of potassium biphthalate-sodium hydroxide buffer solution had obvious influence on the total mass of heavy metal and morphology transformation. Except for metal element Pb and Zn, the addition of different pH potassium dihydrogen phosphate-sodium hydroxide buffer solution could accelerate the soil samples nitrification and the total mass determination of heavy metal in the soil samples. The potassium biphthalate-sodium hydroxide buffer solution could facilitate the acid extractable morphology of Cr, Cu, Hg and Pb, oxidation associated morphology of As, Hg, Pb and Zn and the organic associated morphology transforming of As and Hg. At pH 5.8, the maximum acid extractable morphology contents of Cu and Hg were 2.180 and 0.632 mg x kg(-1), respectively; at pH 6.2, the maximal oxidation associated morphology content of Pb could achieve 27.792 mg x kg(-1); at pH 6.0, the maximum organic associated morphology content of heavy metal Hg was 4.715 mg x kg(-1).

  4. Scandium, yttrium and the lanthanide metals

    International Nuclear Information System (INIS)

    Brown, Paul L.; Ekberg, Christian

    2016-01-01

    The hydroxide and oxide phases that exist for scandium(III) include scandium hydroxide, which likely has both amorphous and crystalline forms, ScOOH(s), and scandium oxide. This chapter presents the data selected for the stability constants of the polymeric hydrolysis species of scandium at zero ionic strength. The behaviour of yttrium, and the lanthanide metals, in the environment is largely dependent on their solution equilibria. Hydrolysis and other complexation reactions of yttrium and the lanthanide metals are important in the disposal of nuclear waste. The trivalent lanthanide metals include lanthanum(III) through lutetium(III). A number of studies have reported a tetrad effect for the geochemical behaviour of the lanthanide series, including stability constants and distribution coefficients. The solubility of many of the lanthanide hydroxide phases has been studied at fixed ionic strength. In studying the hydrolysis of cerium(IV), a number of studies have utilised oxidation-reduction reactions in determining the relevant stability constants.

  5. Attenuation of heavy metal leaching from hazardous wastes by co-disposal of wastes

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Wookeun; Shin, Eung Bai [Hanyang Univ., Ansan (Korea, Republic of); Lee, Kil Chul; Kim, Jae Hyung [National Institute of Environmental Research, Seoul (Korea, Republic of)] [and others

    1996-12-31

    The potential hazard of landfill wastes was previously evaluated by examining the extraction procedures for individual waste, although various wastes were co-disposed of in actual landfills. This paper investigates the reduction of extraction-procedure toxicity by co-disposing various combinations of two wastes. When two wastes are mixed homogeneously, the extraction of heavy metals from the waste mixture is critically affected by the extract pH. Thus, co-disposal wastes will have a resultant pH between the pH values of its constituent. The lower the resultant pH, the lower the concentrations of heavy metals in the extract. When these wastes are extracted sequentially, the latter extracted waste has a stronger influence on the final concentration of heavy metals in the extract. Small-scale lysimeter experiments confirm that when heavy-metal-bearing leachates Generated from hazardous-waste lysimeters are passed through a nonhazardous-waste lysimeter filled with compost, briquette ash, or refuse-incineration ashes, the heavy-metal concentration in the final leachates decreases significantly. Thus, the heavy-metal leaching could be attenuated if a less extraction-procedure-toxic waste were placed at the bottom of a landfill. 3 refs., 4 figs., 5 tabs.

  6. Process for cleaning radioactively contaminated metal surfaces

    International Nuclear Information System (INIS)

    Mihram, R.G.; Snyder, G.A.

    1975-01-01

    A process is described for removing radioactive scale from a ferrous metal surface, including the steps of initially preconditioning the surface by contacting it with an oxidizing solution (such as an aqueous solution of an alkali metal permanganate or hydrogen peroxide), then, after removal or decomposition of the oxidizing solution, the metallic surface is contacted with a cleaning solution which is a mixture of a mineral acid and a complexing agent (such as sulfuric acid and oxalic acid), and which preferably contains a corrosion inhibitor. A final step in the process is the treatment of the spent cleaning solution containing radioactive waste materials in solution by adding a reagent selected from the group consisting of calcium hydroxide or potassium permanganate and an alkali metal hydroxide to thereby form easily recovered metallic compounds containing substantially all of the dissolved metals and radioactivity. (auth)

  7. Influence of alkali metal hydroxides on corrosion of Zr-based alloys

    International Nuclear Information System (INIS)

    Jeong, Y.H.; Ruhmann, H.; Garzarolli, F.

    1997-01-01

    In this study the influence of group-1 alkali hydroxides on different zirconium based alloys has been evaluated. The experiments have been carried out in small stainless steel autoclaves at 350 deg. C in pressurized 17 MPa water, with in low (0.32 mmol), medium (4.3 mmol) and high (31.5 mmol) equimolar concentrations of Li-, Na-, K-, Rb- and Cs-Hydroxides. Two types of alloys have been investigated: Zr-Sn-(Transition metal) and Zr-Sn-Nb-(Transition metal). The corrosion behaviour was evaluated from weight gain measurements. From the experiments the cation could be identified as the responsible species for zirconium alloy corrosion in alkalized water. The radius of the cation governs the corrosion behaviour in the pre accelerated region of zircaloy corrosion. Incorporating of alkali cations into the zirconium oxide lattice is probably the mechanism which allows the corrosion enhancement for Li and Na and the significantly lower effect for the other bases. Nb containing alloys show lower corrosion resistance than alloys from the Zr-Sn-TRM system in all alkali solutions. Both types of alloys corrode significantly more in LiOH and NaOH than in the other alkali environments. Lowest corrosive aggressiveness has been found for CsOH followed by KOH. Concluding from the corrosion behaviour in the different alkali environments and taking into account the tendency to promote accelerate corrosion, CsOH and KOH are possible alternate alkalis for PWR application. (author). 17 refs, 15 figs, 5 tabs

  8. Influence of alkali metal hydroxides on corrosion of Zr-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Y H [Korea Atomic Energy Research Inst., Dae Jun (Korea, Republic of); Ruhmann, H; Garzarolli, F [Siemens-KWU, Power Generation Group, Erlangen (Germany)

    1997-02-01

    In this study the influence of group-1 alkali hydroxides on different zirconium based alloys has been evaluated. The experiments have been carried out in small stainless steel autoclaves at 350 deg. C in pressurized 17 MPa water, with in low (0.32 mmol), medium (4.3 mmol) and high (31.5 mmol) equimolar concentrations of Li-, Na-, K-, Rb- and Cs-Hydroxides. Two types of alloys have been investigated: Zr-Sn-(Transition metal) and Zr-Sn-Nb-(Transition metal). The corrosion behaviour was evaluated from weight gain measurements. From the experiments the cation could be identified as the responsible species for zirconium alloy corrosion in alkalized water. The radius of the cation governs the corrosion behaviour in the pre accelerated region of zircaloy corrosion. Incorporating of alkali cations into the zirconium oxide lattice is probably the mechanism which allows the corrosion enhancement for Li and Na and the significantly lower effect for the other bases. Nb containing alloys show lower corrosion resistance than alloys from the Zr-Sn-TRM system in all alkali solutions. Both types of alloys corrode significantly more in LiOH and NaOH than in the other alkali environments. Lowest corrosive aggressiveness has been found for CsOH followed by KOH. Concluding from the corrosion behaviour in the different alkali environments and taking into account the tendency to promote accelerate corrosion, CsOH and KOH are possible alternate alkalis for PWR application. (author). 17 refs, 15 figs, 5 tabs.

  9. Biohydrometallurgical methods for metals recovery from waste materials

    OpenAIRE

    J. Willner; J. Kadukova; A. Fornalczyk; M. Saternus

    2015-01-01

    The article draws attention to recently conducted research of bacterial leaching of metals from various polymetallic waste. These wastes are the carriers of valuable metals: base metals, precious and platinum group metals (e.g. electronic waste, spent catalysts) or rare earth elements.

  10. Biohydrometallurgical methods for metals recovery from waste materials

    Directory of Open Access Journals (Sweden)

    J. Willner

    2015-01-01

    Full Text Available The article draws attention to recently conducted research of bacterial leaching of metals from various polymetallic waste. These wastes are the carriers of valuable metals: base metals, precious and platinum group metals (e.g. electronic waste, spent catalysts or rare earth elements.

  11. Study of the leaching of heavy metals from waste water sludge and incinerator's ash, using coupled thermostated columns and DTPA as complex agent

    International Nuclear Information System (INIS)

    Vite T, J.; Vite T, M.; Guerrero D, J.; Carreno de Leon, M.C.

    2000-01-01

    We studied the metallic composition from waste water sludge and incinerators ashes of an incinerator located in Toluca, Mexico, the qualitative studies were made using the Activation Analysis technique, and fluorescence X-ray techniques. The quantitative analysis of heavy metals in the wastes were made using Inductively coupled plasma atomic emission spectrometry (Icp-Aes). For leaching the samples, we used four coupled thermostated columns, each one had a p H of 2,5, 7 and 10. The flux of the air was of 1600 cc/min. The temperature was maintain constant in 60 Centigrade using a thermostated system. For this study we used 100 g of wastes mixed with mineral acid or sodium hydroxide to reach p H 2,5,7 and 10. We added a reducing and tensoactive agents and finally DTPA as complex agent. With this method, we obtain a better leaching efficiency using a complex agent. However the high DTPA cost, make this process expansive that is why we recommend to work with another classes of complex agents, that be cheaper to leach metals of different chemistry matrix. (Author)

  12. Chemical decontamination method for radioactive metal waste

    International Nuclear Information System (INIS)

    Tanaka, Akio; Onuma, Tsutomu; Yamazaki, Sei; Miura, Haruki.

    1993-01-01

    The present invention provides a chemical decontamination method for radioactive metal wastes, which are generated from radioactive material handling facilities and the surfaces of which are contaminated by radioactive materials. That is, it has a feature of applying acid dissolution simultaneously with mechanical grinding. The radioactive metal wastes are contained in a vessel such as a barrel together with abrasives in a sulfuric acid solution and rotated at several tens rotation per minute. By such procedures for the radioactive metal wastes, (1) cruds and passive membranes are mechanically removed, (2) exposed mother metal materials are uniformly brought into contact with sulfuric acid and further (3) the mother metal materials dissolve the cruds and the passive membranes also chemically by a reducing dissolution (so-called local cell effect). According to the method of the present invention, stainless steel metal wastes having cruds and passive membranes can rapidly and efficiently be decontaminated to a radiation level equal with that of ordinary wastes. (I.S.)

  13. Lixiviation of heavy metals of hazardous industrial wastes by means of thermostatized columns and design of a pilot plant

    International Nuclear Information System (INIS)

    Vite T, J.; Leon, C.C. de; Vite T, M.; Soto T, J.L.

    2006-01-01

    The purpose of this work was to evaluate the efficiency of lixiviation of heavy metals, using thermostatized columns and hazardous industrial residual wastes: those by the volume with which are generated and its high toxicity, its represent a great problem for it treatment and disposition, in this work a diagram of a pilot plant for extraction of heavy metals is included. The process and equipment were patented in United States and in Mexico. For the development of this study four thermostated columns were used that were coupled. The waste were finely milled and suspended in an aqueous pulp adding of 10 - 40gL -1 of mineral acid or sodium hydroxide until reaching an interval of pH of 2,5,7 and 10. Its were used of 4-10 gL -1 of a reducer agent and of 0.3-1.5 g of a surfactant agent. In some cases with this method was possible to remove until 100% of heavy metals. It was used Plasma Emission Spectroscopy to determine the concentrations of the cations in the lixiviation liquors. For studying the metallic alloys the X-ray diffraction technique was used. (Author)

  14. Production of metal waste forms from spent fuel treatment

    International Nuclear Information System (INIS)

    Westphal, B.R.; Keiser, D.D.; Rigg, R.H.; Laug, D.V.

    1995-01-01

    Treatment of spent nuclear fuel at Argonne National Laboratory consists of a pyroprocessing scheme in which the development of suitable waste forms is being advanced. Of the two waste forms being proposed, metal and mineral, the production of the metal waste form utilizes induction melting to stabilize the waste product. Alloying of metallic nuclear materials by induction melting has long been an Argonne strength and thus, the transition to metallic waste processing seems compatible. A test program is being initiated to coalesce the production of the metal waste forms with current induction melting capabilities

  15. Performance modeling of concrete/metal barriers used in low-level waste disposal

    International Nuclear Information System (INIS)

    Shuman, R.; Chau, Nam; Icenhour, A.S.; Godbee, H.W.; Tharp, M.L.

    1993-01-01

    Low-Level radioactive wastes generated in government and commercial operations involving nuclear materials need to be isolated from the environment almost in perpetuity. An increasing number of disposal sites are using concrete/metal barriers (so called ''engineered'' barriers) to isolate these wastes from the environment. Two major concerns hamper the use of engineered barriers; namely, the lack of ability to reliably predict the service life of these barriers and to estimate the confidence level of the service life predicted. Computer codes (SOURCE1 and SOURCE2) for estimating the long-term (centuries to millennia) service life of these barriers are presented. These codes use mathematical models (based on past observations, currently accepted data, and established theories) to predict behavior into the future. Processes modeled for concrete degradation include sulfate attack, calcium hydroxide leaching, and reinforcement corrosion. The loss of structural integrity due to cracking is also modeled. Mechanisms modeled for nuclide leaching include advection and diffusion. The coupled or linked effects of these models are addressed in the codes. Outputs from the codes are presented and analyzed

  16. Magnesium hydroxide as the neutralizing agent for radioactive hydrochloric acid solutions

    International Nuclear Information System (INIS)

    Palmer, M.J.; Fife, K.W.

    1995-10-01

    The current technology at Los Alamos for removing actinides from acidic chloride waste streams is precipitation with approximately 10 M potassium hydroxide. Although successful, there are many inherent drawbacks to this precipitation technique which will be detailed in this paper. Magnesium hydroxide (K sp = 1.3 x 10 -11 ) has limited solubility in water and as a result of the common ion effect, cannot generate a filtrate with a pH greater than 9. At a pH of 9, calcium (K sp = 5.5 x 10 -6 ) will not coprecipitate as the hydroxide. This is an important factor since many acidic chloride feeds to hydroxide precipitation contain significant amounts of calcium. In addition, neutralization with Mg(OH) 2 produces a more filterable precipitate because neutralization occurs as the Mg(OH) 2 is dissolved by the acid rather than as a result of the much faster liquid/liquid reaction of KOH with the waste acid. This slower solid/liquid reaction allows time for crystal growth to occur and produces more easily filterable precipitates. On the other hand, neutralization of spent acid with strong KOH that yields numerous hydroxide ions in solution almost instantaneously forming a much larger volume of small crystallites that result in gelatinous, slow-filtering precipitates. Magnesium hydroxide also offers a safety advantage. Although mildly irritating, it is a weak base and safe and easy to handle. From a waste minimization perspective, Mg(OH) 2 offers many advantages. First, the magnesium hydroxide is added as a solid. This step eliminates the diluent water used in KOH neutralizations. Secondly, because the particle size of the precipitate is larger, more actinides are caught on the filter paper resulting in a smaller amount of actinide being transferred to the TA-50 Liquid Waste Treatment Facility. Third, the amount of solids that must be reprocessed is significantly smaller resulting in less waste generation from the downstream processes

  17. In-situ nitrite analysis in high level waste tanks

    International Nuclear Information System (INIS)

    O'Rourke, P.E.; Prather, W.S.; Livingston, R.R.

    1992-01-01

    The Savannah River Site produces special nuclear materials used in the defense of the United States. Most of the processes at SRS are primarily chemical separations and purifications. In-situ chemical analyses help improve the safety, efficiency and quality of these operations. One area where in situ fiberoptic spectroscopy can have a great impact is the management of high level radioactive waste. High level radioactive waste at SRS is stored in more than 50 large waste tanks. The waste exists as a slurry of nitrate salts and metal hydroxides at pH's higher than 10. Sodium Nitrite is added to the tanks as a corrosion inhibitor. In-situ fiberoptic probes are being developed to measure the nitrate, nitrite and hydroxide concentrations in both liquid and solid fractions. Nitrite levels can be measured between 0.01M and 1M in a 1mm pathlength optical cell

  18. Growth of PbTe nanorods controlled by polymerized tellurium anions and metal(II) amides via composite-hydroxide-mediated approach

    International Nuclear Information System (INIS)

    Wan Buyong; Hu Chenguo; Liu Hong; Xiong Yufeng; Li Feiyun; Xi Yi; He Xiaoshan

    2009-01-01

    The pure face-centered-cubic PbTe nanorods have been synthesized by the composite-hydroxide-mediated approach using hydrazine as a reducing agent. The method is based on reaction among reactants in the melts of potassium hydroxide and sodium hydroxide eutectic at 170-220 deg. C and normal atmosphere without using any organic dispersant or surface-capping agent. Scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and energy dispersive X-ray spectroscopy were used to characterize the structure, morphology and composition of the samples. The diameters of nanorods are almost fixed, while the lengths can be tunable under different growth time and temperatures. The growth mechanism of PbTe nanorods is investigated via UV-vis absorption, demonstrating that polymerized tellurium anions and metal(II) amides in the hydrazine hydroxide melts could control the crystallization and growth process of PbTe nanostructures. The band gap of as-synthesized PbTe nanorods has been calculated based on UV-vis-NIR optical diffuse reflectance spectra data.

  19. Growth of PbTe nanorods controlled by polymerized tellurium anions and metal(II) amides via composite-hydroxide-mediated approach

    Energy Technology Data Exchange (ETDEWEB)

    Wan Buyong [Department of Applied Physics, Chongqing University, 174 Shapingba Street, Chongqing 400044 (China); College of Physics and Information Technology, Chongqing Normal University, Chongqing 400047 (China); Hu Chenguo, E-mail: hucg@cqu.edu.cn [Department of Applied Physics, Chongqing University, 174 Shapingba Street, Chongqing 400044 (China); Liu Hong [State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Xiong Yufeng [National Center for Nanoscience and Technology, Beijing 100080 (China); Li Feiyun; Xi Yi; He Xiaoshan [Department of Applied Physics, Chongqing University, 174 Shapingba Street, Chongqing 400044 (China)

    2009-09-15

    The pure face-centered-cubic PbTe nanorods have been synthesized by the composite-hydroxide-mediated approach using hydrazine as a reducing agent. The method is based on reaction among reactants in the melts of potassium hydroxide and sodium hydroxide eutectic at 170-220 deg. C and normal atmosphere without using any organic dispersant or surface-capping agent. Scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and energy dispersive X-ray spectroscopy were used to characterize the structure, morphology and composition of the samples. The diameters of nanorods are almost fixed, while the lengths can be tunable under different growth time and temperatures. The growth mechanism of PbTe nanorods is investigated via UV-vis absorption, demonstrating that polymerized tellurium anions and metal(II) amides in the hydrazine hydroxide melts could control the crystallization and growth process of PbTe nanostructures. The band gap of as-synthesized PbTe nanorods has been calculated based on UV-vis-NIR optical diffuse reflectance spectra data.

  20. studies of action of heavy metals on caffeine degradation

    African Journals Online (AJOL)

    User

    2015-12-02

    Dec 2, 2015 ... Sungai Berembang (Perlis), Pantai Teluk Air Tawar and. Sungai Layar ... (0.75% w/v) was added to 100 mL deionised water and heated to 75 °C. Then, .... derived from 36 waste generators and comprised of metal hydroxide ...

  1. Metal decontamination for waste minimization using liquid metal refining technology

    International Nuclear Information System (INIS)

    Joyce, E.L. Jr.; Lally, B.; Ozturk, B.; Fruehan, R.J.

    1993-01-01

    The current Department of Energy Mixed Waste Treatment Project flowsheet indicates that no conventional technology, other than surface decontamination, exists for metal processing. Current Department of Energy guidelines require retrievable storage of all metallic wastes containing transuranic elements above a certain concentration. This project is in support of the National Mixed Low Level Waste Treatment Program. Because of the high cost of disposal, it is important to develop an effective decontamination and volume reduction method for low-level contaminated metals. It is important to be able to decontaminate complex shapes where surfaces are hidden or inaccessible to surface decontamination processes and destruction of organic contamination. These goals can be achieved by adapting commercial metal refining processes to handle radioactive and organic contaminated metal. The radioactive components are concentrated in the slag, which is subsequently vitrified; hazardous organics are destroyed by the intense heat of the bath. The metal, after having been melted and purified, could be recycled for use within the DOE complex. In this project, we evaluated current state-of-the-art technologies for metal refining, with special reference to the removal of radioactive contaminants and the destruction of hazardous organics. This evaluation was based on literature reports, industrial experience, plant visits, thermodynamic calculations, and engineering aspects of the various processes. The key issues addressed included radioactive partitioning between the metal and slag phases, minimization of secondary wastes, operability of the process subject to widely varying feed chemistry, and the ability to seal the candidate process to prevent the release of hazardous species

  2. Perspective of metal encapsulation of waste

    International Nuclear Information System (INIS)

    Jardine, L.J.; Steindler, M.J.

    1978-01-01

    A conceptual flow sheet is presented for encapsulating solid, stabilized calcine (e.g., supercalcine) in a solid lead alloy, using existing or developing technologies. Unresolved and potential problem areas of the flow sheet are outlined and suggestions are made as how metal encapsulation might be applied to other solid wastes from the fuel cycle. It is concluded that metal encapsulation is a technique applicable to many forms of solid wastes and is likely to meet future waste isolation criteria and regulations

  3. Metallurgical recovery of metals from electronic waste: A review

    International Nuclear Information System (INIS)

    Cui Jirang; Zhang Lifeng

    2008-01-01

    Waste electric and electronic equipment, or electronic waste, has been taken into consideration not only by the government but also by the public due to their hazardous material contents. In the detailed literature survey, value distributions for different electronic waste samples were calculated. It is showed that the major economic driver for recycling of electronic waste is from the recovery of precious metals. The state of the art in recovery of precious metals from electronic waste by pyrometallurgical processing, hydrometallurgical processing, and biometallurgical processing are highlighted in the paper. Pyrometallurgical processing has been a traditional technology for recovery of precious metals from waste electronic equipment. However, state-of-the-art smelters are highly depended on investments. Recent research on recovery of energy from PC waste gives an example for using plastics in this waste stream. It indicates that thermal processing provides a feasible approach for recovery of energy from electronic waste if a comprehensive emission control system is installed. In the last decade, attentions have been removed from pyrometallurgical process to hydrometallurgical process for recovery of metals from electronic waste. In the paper, hydrometallurgical processing techniques including cyanide leaching, halide leaching, thiourea leaching, and thiosulfate leaching of precious metals are detailed. In order to develop an environmentally friendly technique for recovery of precious metals from electronic scrap, a critical comparison of main leaching methods is analyzed for both economic feasibility and environmental impact. It is believed that biotechnology has been one of the most promising technologies in metallurgical processing. Bioleaching has been used for recovery of precious metals and copper from ores for many years. However, limited research was carried out on the bioleaching of metals from electronic waste. In the review, initial researches on the

  4. Metallurgical recovery of metals from electronic waste: A review

    Energy Technology Data Exchange (ETDEWEB)

    Cui Jirang [Department of Materials Science and Engineering, Norwegian University of Science and Technology (NTNU), Alfred Getz vei 2, N-7491 Trondheim (Norway)], E-mail: Jirang.Cui@material.ntnu.no; Zhang Lifeng [Department of Materials Science and Engineering, Norwegian University of Science and Technology (NTNU), Alfred Getz vei 2, N-7491 Trondheim (Norway)], E-mail: zhanglife@mst.edu

    2008-10-30

    Waste electric and electronic equipment, or electronic waste, has been taken into consideration not only by the government but also by the public due to their hazardous material contents. In the detailed literature survey, value distributions for different electronic waste samples were calculated. It is showed that the major economic driver for recycling of electronic waste is from the recovery of precious metals. The state of the art in recovery of precious metals from electronic waste by pyrometallurgical processing, hydrometallurgical processing, and biometallurgical processing are highlighted in the paper. Pyrometallurgical processing has been a traditional technology for recovery of precious metals from waste electronic equipment. However, state-of-the-art smelters are highly depended on investments. Recent research on recovery of energy from PC waste gives an example for using plastics in this waste stream. It indicates that thermal processing provides a feasible approach for recovery of energy from electronic waste if a comprehensive emission control system is installed. In the last decade, attentions have been removed from pyrometallurgical process to hydrometallurgical process for recovery of metals from electronic waste. In the paper, hydrometallurgical processing techniques including cyanide leaching, halide leaching, thiourea leaching, and thiosulfate leaching of precious metals are detailed. In order to develop an environmentally friendly technique for recovery of precious metals from electronic scrap, a critical comparison of main leaching methods is analyzed for both economic feasibility and environmental impact. It is believed that biotechnology has been one of the most promising technologies in metallurgical processing. Bioleaching has been used for recovery of precious metals and copper from ores for many years. However, limited research was carried out on the bioleaching of metals from electronic waste. In the review, initial researches on the

  5. Recycling of waste printed circuit boards with simultaneous enrichment of special metals by using alkaline melts: A green and strategically advantageous solution

    Energy Technology Data Exchange (ETDEWEB)

    Stuhlpfarrer, Philipp, E-mail: philipp-johannes.stuhlpfarrer@stud.unileoben.ac.at; Luidold, Stefan; Antrekowitsch, Helmut

    2016-04-15

    Highlights: • Removal of plastics. • Enrichment of In, Ga and Ge. • Low temperature. • No dioxines. - Abstract: The increasing consumption of electric and electronic equipment has led to a rise in toxic waste. To recover the metal fraction, a separation of the organic components is necessary because harmful substances such as chlorine, fluorine and bromine cause ecological damage, for example in the form of dioxins and furans at temperature above 400 °C. Hence, an alternative, environmentally friendly approach was investigated exploiting that a mixture of caustic soda and potassium hydroxide in eutectic composition melts below 200 °C, enabling a fast cracking of the long hydrocarbon chains. The trials demonstrate the removal of organic compounds without a loss of copper and precious metals, as well as a suppressed formation of hazardous off-gases. In order to avoid an input of alkaline elements into the furnace and ensuing problems with refractory materials, a washing step generates a sodium and potassium hydroxide solution, in which special metals like indium, gallium and germanium are enriched. Their concentrations facilitate the recovery of these elements, because otherwise they become lost in the typical recycling processes. The aim of this work was to find an environmental solution for the separation of plastics and metals as well as a strategically important answer for the recycling of printed circuit boards and mobile phones.

  6. Recycling of waste printed circuit boards with simultaneous enrichment of special metals by using alkaline melts: A green and strategically advantageous solution.

    Science.gov (United States)

    Stuhlpfarrer, Philipp; Luidold, Stefan; Antrekowitsch, Helmut

    2016-04-15

    The increasing consumption of electric and electronic equipment has led to a rise in toxic waste. To recover the metal fraction, a separation of the organic components is necessary because harmful substances such as chlorine, fluorine and bromine cause ecological damage, for example in the form of dioxins and furans at temperature above 400°C. Hence, an alternative, environmentally friendly approach was investigated exploiting that a mixture of caustic soda and potassium hydroxide in eutectic composition melts below 200°C, enabling a fast cracking of the long hydrocarbon chains. The trials demonstrate the removal of organic compounds without a loss of copper and precious metals, as well as a suppressed formation of hazardous off-gases. In order to avoid an input of alkaline elements into the furnace and ensuing problems with refractory materials, a washing step generates a sodium and potassium hydroxide solution, in which special metals like indium, gallium and germanium are enriched. Their concentrations facilitate the recovery of these elements, because otherwise they become lost in the typical recycling processes. The aim of this work was to find an environmental solution for the separation of plastics and metals as well as a strategically important answer for the recycling of printed circuit boards and mobile phones. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Recycling of waste printed circuit boards with simultaneous enrichment of special metals by using alkaline melts: A green and strategically advantageous solution

    International Nuclear Information System (INIS)

    Stuhlpfarrer, Philipp; Luidold, Stefan; Antrekowitsch, Helmut

    2016-01-01

    Highlights: • Removal of plastics. • Enrichment of In, Ga and Ge. • Low temperature. • No dioxines. - Abstract: The increasing consumption of electric and electronic equipment has led to a rise in toxic waste. To recover the metal fraction, a separation of the organic components is necessary because harmful substances such as chlorine, fluorine and bromine cause ecological damage, for example in the form of dioxins and furans at temperature above 400 °C. Hence, an alternative, environmentally friendly approach was investigated exploiting that a mixture of caustic soda and potassium hydroxide in eutectic composition melts below 200 °C, enabling a fast cracking of the long hydrocarbon chains. The trials demonstrate the removal of organic compounds without a loss of copper and precious metals, as well as a suppressed formation of hazardous off-gases. In order to avoid an input of alkaline elements into the furnace and ensuing problems with refractory materials, a washing step generates a sodium and potassium hydroxide solution, in which special metals like indium, gallium and germanium are enriched. Their concentrations facilitate the recovery of these elements, because otherwise they become lost in the typical recycling processes. The aim of this work was to find an environmental solution for the separation of plastics and metals as well as a strategically important answer for the recycling of printed circuit boards and mobile phones.

  8. Treatment of wastes arising from decontamination process using citric acid as a decontaminate agent

    International Nuclear Information System (INIS)

    Mierzwa, J.C.; Riella, H.G.; Carvalho, E.U. de

    1993-01-01

    Wastes arising from equipment decontamination processes from nuclear fuel cycle facilities at Coordenacao de Projetos Especiais - Comissao Nacional de Energia Nuclear, Sao Paulo (COPESP-CNEN/SP) has been studied after using citric acid as a decontaminate agent. Precipitation of uranium and metallic impurities resulted from use of sodium hydroxide or calcium oxide plus a flocculation agent. The removal efficient of uranium was 95% and 99% for sodium hydroxide and calcium oxide respectively. The results shows that this process can be used to test wastes from decontamination processes which use citric acid. (B.C.A.). 03 refs, 08 figs, 04 tabs

  9. Glassy slags as novel waste forms for remediating mixed wastes with high metal contents

    International Nuclear Information System (INIS)

    Feng, X.; Wronkiewicz, D.J.; Bates, J.K.; Brown, N.R.; Buck, E.C.; Gong, M.; Ebert, W.L.

    1994-01-01

    Argonne National Laboratory (ANL) is developing a glassy slag final waste form for the remediation of low-level radioactive and mixed wastes with high metal contents. This waste form is composed of various crystalline and metal oxide phases embedded in a silicate glass phase. This work indicates that glassy slag shows promise as final waste form because (1) it has similar or better chemical durability than high-level nuclear waste (HLW) glasses, (2) it can incorporate large amounts of metal wastes, (3) it can incorporate waste streams having low contents of flux components (boron and alkalis), (4) it has less stringent processing requirements (e.g., viscosity and electric conductivity) than glass waste forms, (5) its production can require little or no purchased additives, which can result in greater reduction in waste volume and overall treatment costs. By using glassy slag waste forms, minimum additive waste stabilization approach can be applied to a much wider range of waste streams than those amenable only to glass waste forms

  10. Synthesis, characterization and application of two-dimensional layered metal hydroxides for environmental remediation purposes

    Science.gov (United States)

    Machingauta, Cleopas

    Two-dimensional layered nano composites, which include layered double hydroxides (LDHs), hydroxy double salts (HDSs) and layered hydroxide salts (LHSs) are able to intercalate different molecular species within their gallery space. These materials have a tunable structural composition which has made them applicable as fire retardants, adsorbents, catalysts, catalyst support materials, and ion exchangers. Thermal treatment of these materials results in destruction of the layers and formation of mixed metal oxides (MMOs) and spinels. MMOs have the ability to adsorb anions from solution and may also regenerate layered structures through a phenomenon known as memory effect. Zinc-nickel hydroxy nitrate was used for the uptake of a series of halogenated acetates (HAs). HAs are pollutants introduced into water systems as by-products of water chlorination and pesticide degradation; their sequestration from water is thus crucial. Optimization of layered materials for controlled uptake requires an understanding of their ion-exchange kinetics and thermodynamics. Exchange kinetics of these anions was monitored using ex-situ PXRD, UV-vis, HPLC and FTIR. It was revealed that exchange rates and uptake efficiencies are related to electronic spatial extents and the charge on carboxyl-oxygen atoms. In addition, acetate and nitrate-based HDSs were used to explore how altering the hydroxide layer affects uptake of acetate/nitrate ions. Changing the metal identities affects the interaction of the anions with the layers. From FTIR, we observed that nitrates coordinate in a D3h and Cs/C 2v symmetry; the nitrates in D3h symmetry were easily exchangeable. Interlayer hydrogen bonding was also revealed to be dependent on metal identity. Substituting divalent cations with trivalent cations produces materials with a higher charge density than HDSs and LHSs. A comparison of the uptake efficiency of zinc-aluminum, zinc-gallium and zinc-nickel hydroxy nitrates was performed using trichloroacetic

  11. Hydrogen production coupled to nuclear waste treatment: the safe treatment of alkali metals through a well-demonstrated process

    International Nuclear Information System (INIS)

    Rahier, A.; Mesrobian, G.

    2006-01-01

    In 1992, the United Nations emphasised the urgent need to act against the perpetuation of disparities between and within nations, the worsening of poverty, hunger, ill health and illiteracy and the continuing deterioration of ecosystems on which we depend for our well-being. In this framework, taking into account the preservation of both worldwide energy resources and ecosystems, the use of nuclear energy to produce clean energy carriers, such as hydrogen, is undoubtedly advisable. However, coping fully with the Agenda 21 statements requires defining adequate treatment processes for nuclear wastes. This paper discusses the possible use of a well-demonstrated process to convert radioactively contaminated alkali metals into sodium hydroxide while producing hydrogen. We conclude that a synergy between Chlor-Alkali specialists and nuclear specialists may help find an acceptable solution for radioactively contaminated sodium waste. (author)

  12. Method of dissolving metal ruthenium

    International Nuclear Information System (INIS)

    Tsuno, Masao; Soda, Yasuhiko; Kuroda, Sadaomi; Koga, Tadaaki.

    1988-01-01

    Purpose: To dissolve and clean metal ruthenium deposited to the inner surface of a dissolving vessel for spent fuel rods. Method: Metal ruthenium is dissolved in a solution of an alkali metal hydroxide to which potassium permanganate is added. As the alkali metal hydroxide used herein there can be mentioned potassium hydroxide, sodium hydroxide and lithium hydroxide can be mentioned, which is used as an aqueous solution from 5 to 20 % concentration in view of the solubility of metal ruthenium and economical merit. Further, potassium permanganate is used by adding to the solution of alkali metal hydroxide at a concentration of 1 to 5 %. (Yoshihara, H.)

  13. Magnesium alloys and graphite wastes encapsulated in cementitious materials: Reduction of galvanic corrosion using alkali hydroxide activated blast furnace slag

    Energy Technology Data Exchange (ETDEWEB)

    Chartier, D., E-mail: david.chartier@cea.fr [Commissariat à l' Energie Atomique et aux Energies Alternatives, CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze (France); Muzeau, B. [DEN-Service d’Etude du Comportement des Radionucléides (SECR), CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Stefan, L. [AREVA NC/D& S - France/Technical Department, 1 place Jean Millier 92084 Paris La Défense (France); Sanchez-Canet, J. [Commissariat à l' Energie Atomique et aux Energies Alternatives, CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze (France); Monguillon, C. [DEN-Service d’Etude du Comportement des Radionucléides (SECR), CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France)

    2017-03-15

    Highlights: • Embedded in cement, magnesium is corroded by residual water present in porosity of the matrix. • Corrosion is enhanced by galvanic phenomenon when magnesium is in contact with graphite. • Galvanic corrosion of magnesium in contact with graphite debris is shown to be severe with ordinary Portland cement. • Galvanic corrosion is significantly lowered in high alkali medium such as sodium hydroxide. • Sodium hydroxide activated blast furnace slag is a convenient binder to embed magnesium. - Abstract: Magnesium alloys and graphite from spent nuclear fuel have been stored together in La Hague plant. The packaging of these wastes is under consideration. These wastes could be mixed in a grout composed of industrially available cement (Portland, calcium aluminate…). Within the alkaline pore solution of these matrixes, magnesium alloys are imperfectly protected by a layer of Brucite resulting in a slow corrosion releasing hydrogen. As the production of this gas must be considered for the storage safety, and the quality of wasteform, it is important to select a cement matrix capable of lowering the corrosion kinetics. Many types of calcium based cements have been tested and most of them have caused strong hydrogen production when magnesium alloys and graphite are conditioned together because of galvanic corrosion. Exceptions are binders based on alkali hydroxide activated ground granulated blast furnace slag (BFS) which are presented in this article.

  14. Magnesium alloys and graphite wastes encapsulated in cementitious materials: Reduction of galvanic corrosion using alkali hydroxide activated blast furnace slag

    International Nuclear Information System (INIS)

    Chartier, D.; Muzeau, B.; Stefan, L.; Sanchez-Canet, J.; Monguillon, C.

    2017-01-01

    Highlights: • Embedded in cement, magnesium is corroded by residual water present in porosity of the matrix. • Corrosion is enhanced by galvanic phenomenon when magnesium is in contact with graphite. • Galvanic corrosion of magnesium in contact with graphite debris is shown to be severe with ordinary Portland cement. • Galvanic corrosion is significantly lowered in high alkali medium such as sodium hydroxide. • Sodium hydroxide activated blast furnace slag is a convenient binder to embed magnesium. - Abstract: Magnesium alloys and graphite from spent nuclear fuel have been stored together in La Hague plant. The packaging of these wastes is under consideration. These wastes could be mixed in a grout composed of industrially available cement (Portland, calcium aluminate…). Within the alkaline pore solution of these matrixes, magnesium alloys are imperfectly protected by a layer of Brucite resulting in a slow corrosion releasing hydrogen. As the production of this gas must be considered for the storage safety, and the quality of wasteform, it is important to select a cement matrix capable of lowering the corrosion kinetics. Many types of calcium based cements have been tested and most of them have caused strong hydrogen production when magnesium alloys and graphite are conditioned together because of galvanic corrosion. Exceptions are binders based on alkali hydroxide activated ground granulated blast furnace slag (BFS) which are presented in this article.

  15. Aluminum Removal And Sodium Hydroxide Regeneration From Hanford Tank Waste By Lithium Hydrotalcite Precipitation Summary Of Prior Lab-Scale Testing

    International Nuclear Information System (INIS)

    Sams, T.L.; Guillot, S.

    2011-01-01

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

  16. Efficient removal of dyes by a novel magnetic Fe{sub 3}O{sub 4}/ZnCr-layered double hydroxide adsorbent from heavy metal wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Dan; Li, Yang; Zhang, Jia [School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444 (China); Li, Wenhui [Department of Chemistry, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China); Zhou, Jizhi; Shao, Li [School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444 (China); Qian, Guangren, E-mail: grqian@shu.edu.cn [School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444 (China)

    2012-12-15

    Graphical abstract: To purify heavy metal wastewater (pickling waste liquor (PWL{sub A} and PWL{sub B}) and electroplating wastewater (EPW{sub C} and EPW{sub D})), a novel magnetic Fe{sub 3}O{sub 4}/ZnCr-LDH material was formed via two-step microwave hydrothermal method (Step 1 and Step 2) and applicable for organic dyes wastewater treatment. Highlights: Black-Right-Pointing-Pointer Fe{sub 3}O{sub 4}/ZnCr-layered double hydroxide adsorbent was produced from wastewater. Black-Right-Pointing-Pointer RSM was successfully applied to the optimization of the preparation conditions. Black-Right-Pointing-Pointer The maximum adsorption capacity of MO was found to be 240.16 mg/g. Black-Right-Pointing-Pointer The MO adsorption mechanism on MFLA was certified. Black-Right-Pointing-Pointer MFLA could be recycled after catalytic regeneration by the oxidation technology. - Abstract: A novel magnetic Fe{sub 3}O{sub 4}/ZnCr-layered double hydroxide adsorbent was produced from electroplating wastewater and pickling waste liquor via a two-step microwave hydrothermal method. Adsorption of methyl orange (MO) from water was studied using this material. The effects of three variables have been investigated by a single-factor method. The response surface methodology (RSM) based on Box-Behnken design was successfully applied to the optimization of the preparation conditions. The maximum adsorption capacity of MO was found to be 240.16 mg/g, indicating that this material may be an effective adsorbent. It was shown that 99% of heavy metal ions (Fe{sup 2+}, Fe{sup 3+}, Cr{sup 3+}, and Zn{sup 2+}) can be effectively removed into precipitates and released far less in the adsorption process. In addition, this material with adsorbed dye can be easily separated by a magnetic field and recycled after catalytic regeneration with advanced oxidation technology. Meanwhile, kinetic models, FTIR spectra and X-ray diffraction pattern were applied to the experimental data to examine uptake mechanism. The

  17. Promotion Effect of Alkali Metal Hydroxides on Polymer-Stabilized Pd Nanoparticles for Selective Hydrogenation of C–C Triple Bonds in Alkynols

    OpenAIRE

    Nikoshvili, Linda Zh.; Bykov, Alexey V.; Khudyakova, Tatiana E.; Lagrange, Thomas; Héroguel, Florent; Luterbacher, Jeremy S.; Matveeva, Valentina G.; Sulman, Esther M.; Dyson, Paul J.; Kiwi-Minsker, Lioubov

    2017-01-01

    Postimpregnation of Pd nanoparticles (NPs) stabilized within hyper-cross-linked polystyrene with sodium or potassium hydroxides of optimal concentration was found to significantly increase the catalytic activity for the partial hydrogenation of the C–C triple bond in 2-methyl-3-butyn-2-ol at ambient hydrogen pressure. The alkali metal hydroxide accelerates the transformation of the residual Pd(II) salt into Pd(0) NPs and diminishes the reaction induction period. In addition, the selectivity t...

  18. Aluminum Hydroxide and Magnesium Hydroxide

    Science.gov (United States)

    Aluminum Hydroxide, Magnesium Hydroxide are antacids used together to relieve heartburn, acid indigestion, and upset stomach. They ... They combine with stomach acid and neutralize it. Aluminum Hydroxide, Magnesium Hydroxide are available without a prescription. ...

  19. Regeneration of Waste Edible Oil by the Use of Virgin and Calcined Magnesium Hydroxide as Adsorbents.

    Science.gov (United States)

    Ogata, Fumihiko; Kawasaki, Naohito

    2016-01-01

    In this study, we prepared virgin (S, L) and calcined (S-380, S-1000, L-380, L-1000) magnesium hydroxide for regeneration of waste edible oil. Deterioration of soybean oil, rapeseed oil, and olive oil was achieved by heat and aeration treatment. The properties of the different adsorbents were investigated using specific surface area measurements, scanning electron microscopy, X-ray diffraction analysis, thermogravimetric-differential thermal analysis, and surface pH measurement. Moreover, the relationship between the changes in acid value (AV) and carbonyl value (CV) and the adsorbent properties were evaluated. The specific surface areas of S-380 and L-380 were greater than that of other adsorbents. In addition, the XRD results show that S-380 and L-380 contain both magnesium hydroxide and magnesium oxide structures. The decreases in AV and CV using S-380 and L-380 were greater than achieved using other adsorbents. The correlation coefficients between the decrease in AV and CV and specific surface area were 0.947 for soybean oil, 0.649 for rapeseed oil, and 0.773 for olive oil, respectively. The results obtained in this study suggest that a physical property of the adsorbent, namely specific surface area, was primarily responsible for the observed decreases in AV and CV. Overall, the results suggest that S-380 and L-380 are useful for the regeneration of waste edible oil.

  20. PERSPECTIVE SOURCES OF METALS RESOURCES (CU, NI FOR CAST IRON ALLOYING, ARISING ON THE TERRITORY OF THE REPUBLIC OF BELARUS

    Directory of Open Access Journals (Sweden)

    V. L. Tribushevski

    2005-01-01

    Full Text Available The article is dedicated to the practical foundation of combined resources-economy technologies of the alloyed cast iron melting using wastes of galvanic productions, containing sulfates and hydroxides of these metals, instead of metallic nickel and copper.

  1. Method and apparatus for treatment of animal waste products

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, R R

    1977-12-15

    Animal wastes (fresh manure and urine) are converted to products useful on farmland or in animal feed by treating them with alkali metal hydroxides or carbonates and/or alkaline earth hydroxides to give slurries with pH 9.0 to 12.0, thus deactivating urease. Thus, a slurry of swine manure and urine adjusted with CaO to pH 11 has urea content 27.0 and 26.5 mg/L after 0 and 10 days, respectively, at 20/sup 0/, compared with 22.0 and 0, respectively, in the absence of base.

  2. Accumulation of heavy metals by vegetables grown in mine wastes

    Energy Technology Data Exchange (ETDEWEB)

    Cobb, G.P.; Sands, K.; Waters, M.; Wixson, B.G.; Dorward-King, E.

    2000-03-01

    Lead, cadmium, arsenic, and zinc were quantified in mine wastes and in soils mixed with mine wastes. Metal concentrations were found to be heterogeneous in the wastes. Iceberg lettuce, Cherry Belle radishes, Roma bush beans, and Better Boy tomatoes were cultivated in mine wastes and in waste-amended soils. Lettuce and radishes had 100% survival in the 100% mine waste treatments compared to 0% and 25% survival for tomatoes and beans, respectively. Metal concentrations were determined in plant tissues to determine uptake and distribution of metals in the edible plant parts. Individual soil samples were collected beneath each plant to assess metal content in the immediate plant environment. This analysis verified heterogeneous metal content of the mine wastes. The four plant species effectively accumulated and translocated lead, cadmium, arsenic, and zinc. Tomato and bean plants contained the four metals mainly in the roots and little was translocated to the fruits. Radish roots accumulated less metals compared to the leaves, whereas lettuce roots and leaves accumulated similar concentrations of the four metals. Lettuce leaves and radish roots accumulated significantly more metals than bean and tomato fruits. This accumulation pattern suggests that consumption of lettuce leaves or radish roots from plants grown in mine wastes would pose greater risks to humans and wildlife than would consumption of beans or tomatoes grown in the same area. The potential risk may be mitigated somewhat in humans, as vegetables grown in mine wastes exhibited stunted growth and chlorosis.

  3. The potential for using slags activated with near neutral salts as immobilisation matrices for nuclear wastes containing reactive metals

    Science.gov (United States)

    Bai, Y.; Collier, N. C.; Milestone, N. B.; Yang, C. H.

    2011-06-01

    The UK currently uses composite blends of Portland cement and other inorganic cementitious material such as blastfurnace slag and pulverised fuel ash to encapsulate or immobilise intermediate and low level radioactive wastes. Typically levels up 9:1 blast furnace slag:Portland cement or 4:1 pulverised fuel ash:Portland cement are used. Whilst these systems offer many advantages, their high pH causes corrosion of various metallic intermediate level radioactive wastes. To address this issue, lower pH/weakly alkaline cementitious systems have to be explored. While the blast furnace slag:Portland cement system is referred to as a composite cement system, the underlying reaction is actually an indirect activation of the slag hydration by the calcium hydroxide generated by the cement hydration, and by the alkali ions and gypsum present in the cement. However, the slag also can be activated directly with activators, creating a system known as alkali-activated slag. Whilst these activators used are usually strongly alkaline, weakly alkaline and near neutral salts can also be used. In this paper, the potential for using weakly alkaline and near neutral salts to activate slag in this manner is reviewed and discussed, with particular emphasis placed on the immobilisation of reactive metallic nuclear wastes.

  4. Layered Double Hydroxides as Effective Adsorbents for U(VI and Toxic Heavy Metals Removal from Aqueous Media

    Directory of Open Access Journals (Sweden)

    G. N. Pshinko

    2013-01-01

    Full Text Available Capacities of different synthesized Zn,Al-hydrotalcite-like adsorbents, including the initial carbonate [Zn4Al2(OH12]·CO3·8H2O and its forms intercalated with chelating agents (ethylenediaminetetraacetic acid (EDTA, diethylenetriaminepentaacetic acid (DTPA, and hexamethylenediaminetetraacetic acid (HMDTA and heat-treated form Zn4Al2O7, to adsorb uranium(VI and ions of toxic heavy metals have been compared. Metal sorption capacities of hydrotalcite-like adsorbents have been shown to correlate with the stability of their complexes with the mentioned chelating agents in a solution. The synthesized layered double hydroxides (LDHs containing chelating agents in the interlayer space are rather efficient for sorption purification of aqueous media free from U(VI irrespective of its forms of natural abundance (including water-soluble bi- and tricarbonate forms and from heavy metal ions. [Zn4Al2(OH12]·EDTA·nH2O is recommended for practical application as one of the most efficient and inexpensive synthetic adsorbents designed for recovery of both cationic and particularly important anionic forms of U(VI and other heavy metals from aqueous media. Carbonate forms of LDHs turned out to be most efficient for recovery of Cu(II from aqueous media with pH0≥7 owing to precipitation of Cu(II basic carbonates and Cu(II hydroxides. Chromate ions are efficiently adsorbed from water only by calcinated forms of LDHs.

  5. Process for reclaiming tungsten from a hazardous waste

    International Nuclear Information System (INIS)

    Scheithauer, R.A.; MacInnis, M.B.; Miller, M.J.; Vanderpool, C.D.

    1984-01-01

    A process is disclosed wherein tungsten is recovered from hazardous waste material containing said tungsten, arsenic, and other impurities which can consist of magnesium, phosphorus, and silicon and the resulting waste is treated to render it nonhazardous according to EPA standards for arsenic. Said process involves digesting said hazardous waste material in an aqueous solution of an alkali metal hydroxide, adjusting the pH of the resulting solution to about 11.0 to about 13.0 with NaOH to precipitate essentially all of the magnesium and silicon species, filtering the digestion mix to remove the solids from said resulting solution which contains about 80 to about 100% of said tungsten and essentially none of said magnesium and said silicon, slurrying the hazardous solids in hot water, and adding to the slurry a ferric salt solution to precipitate ferric hydroxide, filtering this mixture to give a solid which passes the EPA standard test for solids with respect to arsenic

  6. Methods for recovering precious metals from industrial waste

    Science.gov (United States)

    Canda, L.; Heput, T.; Ardelean, E.

    2016-02-01

    The accelerated rate of industrialization increases the demand for precious metals, while high quality natural resources are diminished quantitatively, with significant operating costs. Precious metals recovery can be successfully made from waste, considered to be secondary sources of raw material. In recent years, concerns and interest of researchers for more increasing efficient methods to recover these metals, taking into account the more severe environmental protection legislation. Precious metals are used in a wide range of applications, both in electronic and communications equipment, spacecraft and jet aircraft engines and for mobile phones or catalytic converters. The most commonly recovered precious metals are: gold from jewellery and electronics, silver from X- ray films and photographic emulsions, industrial applications (catalysts, batteries, glass/mirrors), jewellery; platinum group metals from catalytic converters, catalysts for the refining of crude oil, industrial catalysts, nitric acid manufacturing plant, the carbon-based catalyst, e-waste. An important aspect is the economic viability of recycling processes related to complex waste flows. Hydrometallurgical and pyrometallurgical routes are the most important ways of processing electrical and electronic equipment waste. The necessity of recovering precious metals has opened new opportunities for future research.

  7. Nuclear waste storage container with metal matrix

    Science.gov (United States)

    Sump, Kenneth R.

    1978-01-01

    The invention relates to a storage container for high-level waste having a metal matrix for the high-level waste, thereby providing greater impact strength for the waste container and increasing heat transfer properties.

  8. Nuclear waste storage container with metal matrix

    International Nuclear Information System (INIS)

    Sump, K.R.

    1978-01-01

    The invention relates to a storage container for high-level waste having a metal matrix for the high-level waste, thereby providing greater impact strength for the waste container and increasing heat transfer properties

  9. Nickel-cobalt hydroxide nanosheets: Synthesis, morphology and electrochemical properties.

    Science.gov (United States)

    Schneiderová, Barbora; Demel, Jan; Zhigunov, Alexander; Bohuslav, Jan; Tarábková, Hana; Janda, Pavel; Lang, Kamil

    2017-08-01

    This paper reports the synthesis, characterization, and electrochemical performance of nickel-cobalt hydroxide nanosheets. The hydroxide nanosheets of approximately 0.7nm thickness were prepared by delamination of layered nickel-cobalt hydroxide lactate in water and formed transparent colloids that were stable for months. The nanosheets were deposited on highly oriented pyrolytic graphite by spin coating, and their electrochemical behavior was investigated by cyclic voltammetry in potassium hydroxide electrolyte. Our method of electrode preparation allows for studying the electrochemistry of nanosheets where the majority of the active centers can participate in the charge transfer reaction. The observed electrochemical response was ascribed to mutual compensation of the cobalt and nickel response via electron sharing between these metals in the hydroxide nanosheets, a process that differentiates the behavior of nickel-cobalt hydroxide nanosheets from single nickel hydroxide or cobalt hydroxide nanosheets or their physical mixture. The presence of cobalt in the nickel-cobalt hydroxide nanosheets apparently decreases the time of electrochemical activation of the nanosheet layer, which for the nickel hydroxide nanosheets alone requires more potential sweeps. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Production of calcium hydroxide from the waste of Cariri stone; Producao de hidroxido de calcio a partir de residuo da pedra Cariri

    Energy Technology Data Exchange (ETDEWEB)

    Alves, T.M.E.; Santos, A.M.M.; Brasileiro, M.I.; Pinheiro, S.F.L.; Prado, A.C.A., E-mail: tiagomaiaea@gmail.com [Universidade Federal do Cariri (UFCA), Juazeiro do Norte, CE (Brazil)

    2016-07-01

    The extraction of Cariri stone in the northeast is a frequent activity because of its ornamental application as well as for the construction sector. However, by this extraction, untapped waste formation grows and becomes a problem for the environment. The objective of this work is to produce calcium hydroxide, from this limestone residue, with controlled porosity, solubility and particle size. The waste was characterized with X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF) and thermal analysis (TGA). The limestone was calcined at 850°C and 950°C for 45 minutes and three hours, being characterized by XRD, XRF and TGA. Once calcined, it was hydrated with 17,5g and 22g oxide to 100mL water and manually mixed for 15 and 25 minutes. The calcium hydroxides have been submitted for tests in vivo in rats and will be characterized by XRD, Scanning Electron Microscopy (SEM) and Infrared. (author)

  11. Chemical decontamination method for radioactive metal waste

    International Nuclear Information System (INIS)

    Onuma, Tsutomu; Tanaka, Akio; Shibuya, Sadao.

    1991-01-01

    When contaminants mainly composed of copper remained on the surface of stainless steel wastes sent from an electrolytic reduction as a first step are chemically decontaminated, metal wastes are discriminated to carbon steel wastes and stainless steel wastes. Then, the carbon steel wastes are applied only with the first step of immersing in a sulfuric acid solution, and stainless steel wastes are applied with a first step of immersing into a sulfuric acid solution for electrolytic reduction for a predetermined period of time and a second step of immersing into a liquid in which an oxidative metal salt is added to sulfuric acid. The decontamination liquid which is used for immersing the stainless steel wastes in the second step and the oxidation force of which is lowered is used as the sulfuric acid solution in the first step for the carbon steel wastes. In view of the above, the decontamination liquid of the second step can be utilized most effectively, enabling to greatly decrease the secondary wastes and to improve decontamination efficiency. (T.M.)

  12. Lixiviation of heavy metals of hazardous industrial wastes by means of thermostatized columns and design of a pilot plant; Lixiviacion de metales pesados de residuos industriales peligrosos por medio de columnas termostatizadas y diseno de una planta piloto

    Energy Technology Data Exchange (ETDEWEB)

    Vite T, J.; Leon, C.C. de [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Vite T, M.; Soto T, J.L. [IPN, SEPI, ESIME 07738 Mexico D.F. (Mexico)]. e-mail: jvite@nuclear.inin.mx

    2006-07-01

    purpose of this work was to evaluate the efficiency of lixiviation of heavy metals, using thermostatized columns and hazardous industrial residual wastes: those by the volume with which are generated and its high toxicity, its represent a great problem for it treatment and disposition, in this work a diagram of a pilot plant for extraction of heavy metals is included. The process and equipment were patented in United States and in Mexico. For the development of this study four thermostated columns were used that were coupled. The waste were finely milled and suspended in an aqueous pulp adding of 10 - 40gL{sup -1} of mineral acid or sodium hydroxide until reaching an interval of pH of 2,5,7 and 10. Its were used of 4-10 gL{sup -1} of a reducer agent and of 0.3-1.5 g of a surfactant agent. In some cases with this method was possible to remove until 100% of heavy metals. It was used Plasma Emission Spectroscopy to determine the concentrations of the cations in the lixiviation liquors. For studying the metallic alloys the X-ray diffraction technique was used. (Author)

  13. Method for decontaminating radiation metal waste

    International Nuclear Information System (INIS)

    Onuma, Tsutomu; Tanaka, Akio; Akimoto, Hidetoshi

    1991-01-01

    This report describes a method for decontaminating radiation metal waste characterized by the following properties: in order to decontaminate radiation metal waste of various shapes produced by facilities involved with radioactive substances, non-complex shapes are decontaminated by electropolishing the materials in a neutral saline solution. Complex shapes are chemically decontaminated by means of an acid solution containing permanganic acid or an alkaline solution and a mineral acid solution. After neutralizing the solutions used for chemical decontamination, the radioactive material is separated and removed. Further, in the decontamination method for radioactive metal waste, a supernatant liquid is reused as the electrolyte in electropolishing decontamination. Permanganic ions (MnO 4 - ) are reduced to manganese dioxide (MnO 2 ) and deposited prior to neutralizing the solution used for chemical decontamination. Once manganese dioxide (MnO 2 ) has been separated and removed, it is re-used as the electrolyte in electropolishing decontamination by means of a process identical to the separation process for radioactive substances. 3 figs

  14. Studies on MgNi-Based Metal Hydride Electrode with Aqueous Electrolytes Composed of Various Hydroxides

    Directory of Open Access Journals (Sweden)

    Jean Nei

    2016-08-01

    Full Text Available Compositions of MgNi-based amorphous-monocrystalline thin films produced by radio frequency (RF sputtering with a varying composition target have been optimized. The composition Mg52Ni39Co3Mn6 is identified to possess the highest initial discharge capacity of 640 mAh·g−1 with a 50 mA·g−1 discharge current density. Reproduction in bulk form of Mg52Ni39Co3Mn6 alloy composition was prepared through a combination of melt spinning (MS and mechanical alloying (MA, shows a sponge-like microstructure with >95% amorphous content, and is chosen as the metal hydride (MH alloy for a sequence of electrolyte experiments with various hydroxides including LiOH, NaOH, KOH, RbOH, CsOH, and (C2H54N(OH. The electrolyte conductivity is found to be closely related to cation size in the hydroxide compound used as 1 M additive to the 4 M KOH aqueous solution. The degradation performance of Mg52Ni39Co3Mn6 alloy through cycling demonstrates a strong correlation with the redox potential of the cation in the alkali hydroxide compound used as 1 M additive to the 5 M KOH aqueous solution. NaOH, CsOH, and (C2H54N(OH additions are found to achieve a good balance between corrosion and conductivity performances.

  15. Recycling of metals from metal containing industrial wastes by means of plasma

    International Nuclear Information System (INIS)

    Burkhard, R.

    1995-01-01

    Recovery of metals from complex mixed wastes is a challenging task of modern material and waste management strategies. Thermal methods are an important tool in this respect. Plasma turned out to be particularly useful for treatment of complex or toxic wastes and residuals. In order to study the recycling parameters and behaviour of different metal containing wastes at reasonable costs, two pilot plasma plants have been used and metal containing, industrial wastes like spent Raney-Nickel catalysts, copper and aluminium drosses, MMC's, scrap, and others were investigated. The heart of the plasma equipment used is the Rotating Hearth (PRH) with a central base orifice. The hearth of the furnace rotates with a speed which prevents the melt from dripping. For pouring, the rotational speed is lowered, which allows the melt to be dripped into a mould. The RIF2 is equipped with a transferred plasma torch which can be operated up to 200 kW. The furnace is equipped with a secondary combustion chamber (SCC). The gases leaving the SCC go through a quench/scrubber. A powerful fan maintains underpressure in the whole system. Waste and additives can be fed through a nitrogen-purged port batchwise or with a screw feeder. The main components of the waste material investigated are nickel and aluminium in Raney-Nickel. The goal to recycle it is to produce NiFe-alloys for further use in the steel industry, or even NiAl-alloy for new catalyst production by using aluminium scrap as reducing and alloying element respectively. Aluminium dross occurs as an unavoidable by-product of all aluminium melting operations. It consists of metallic aluminium, oxides, nitrides, and salts. The separation of the aluminium phase from the oxides is the main task for recycling the aluminium. The general result is: recovery of metals out of complex mixed waste by using plasma rotating hearth technology and appropriate furnace modifications is feasible and ecological-economically interesting. (author) 147

  16. The Recovery of Zinc Heavy Metal from Industrial Liquid Waste

    International Nuclear Information System (INIS)

    Panggabean, Sahat M.

    2000-01-01

    It had been studied the recovery of zinc heavy metal from liquid waste of electroplating industry located at East Jakarta. The aim of this study was to minimize the waste arisen from industrial activities by taking out zinc metal in order to reused on-site. The method of recovery was two steps precipitation using NaOH reagent and pH variation. The first step of precipitation at pH optimum around 6 yielded iron metal. The second step at pH optimum around 10 yielded zinc metal. The zinc metal was taken out assessed to the possibility of reused at that fabric. By applying its, it will yield the volume reduction of sludge waste about 36.1% or 53.2% of zinc metal containing in the waste. It means the cost of waste treatment will be lower. Beside its, the effluent arisen from the method had fulfill the maximum limit and it allowed to release to the environment. (author)

  17. Separation of Metals From Spent Catalysts Waste by Bioleaching Process

    OpenAIRE

    Sirin Fairus, Tria Liliandini, M.Febrian, Ronny Kurniawan

    2010-01-01

    A kind of waste that hard to be treated is a metal containing solid waste. Leaching method is one thealternative waste treatment. But there still left an obstacle on this method, it is the difficulty to find theselective solvent for the type of certain metal that will separated. Bioleaching is one of the carry ablealternative waste treatments to overcome that obstacle. Bioleaching is a metal dissolving process orextraction from a sediment become dissolve form using microorganisms. On this met...

  18. Thermodynamic Properties of Alkali Metal Hydroxides. Part II. Potassium, Rubidium, and Cesium Hydroxides

    International Nuclear Information System (INIS)

    Gurvich, L.V.; Bergman, G.A.; Gorokhov, L.N.; Iorish, V.S.; Leonidov, V.Y.; Yungman, V.S.

    1997-01-01

    The data on thermodynamic and molecular properties of the potassium, rubidium and cesium hydroxides have been collected, critically reviewed, analyzed, and evaluated. Tables of the thermodynamic properties [C p circ , Φ=-(G -H(0)/T, S, H -H(0), Δ f H, Δ f G)] of these hydroxides in the condensed and gaseous states have been calculated using the results of the analysis and some estimated values. The recommendations are compared with earlier evaluations given in the JANAF Thermochemical Tables and Thermodynamic Properties of Individual Substances. The properties considered are: the temperature and enthalpy of phase transitions and fusion, heat capacities, spectroscopic data, structures, bond energies, and enthalpies of formation at 298.15 K. The thermodynamic functions in solid, liquid, and gaseous states are calculated from T=0 to 2000 K for substances in condensed phase and up to 6000 K for gases. copyright 1997 American Institute of Physics and American Chemical Society

  19. Method of processing radioactive liquid wastes

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Y; Kikuchi, M; Funabashi, K; Yusa, H; Horiuchi, S

    1978-12-21

    Purpose: To decrease the volume of radioactive liquid wastes essentially consisting of sodium hydroxide and boric acid. Method: The concentration ratio of sodium hydroxide to boric acid by weight in radioactive liquid wastes essentially consisting of sodium hydroxide and boric acid is adjusted in the range of 0.28 - 0.4 by means of a pH detector and a sodium concentration detector. Thereafter, the radioactive liquid wastes are dried into powder and then discharged.

  20. Flow analysis of metals in a municipal solid waste management system

    International Nuclear Information System (INIS)

    Jung, C.H.; Matsuto, T.; Tanaka, N.

    2006-01-01

    This study aimed to identify the metal flow in a municipal solid waste (MSW) management system. Outputs of a resource recovery facility, refuse derived fuel (RDF) production facility, carbonization facility, plastics liquefaction facility, composting facility, and bio-gasification facility were analyzed for metal content and leaching concentration. In terms of metal content, bulky and incombustible waste had the highest values. Char from a carbonization facility, which treats household waste, had a higher metal content than MSW incinerator bottom ash. A leaching test revealed that Cd and Pb in char and Pb in RDF production residue exceeded the Japanese regulatory criteria for landfilling, so special attention should be paid to final disposal of these substances. By multiplying metal content and the generation rate of outputs, the metal content of input waste to each facility was estimated. For most metals except Cr, the total contribution ratio of paper/textile/plastics, bulky waste, and incombustible waste was over 80%. Approximately 30% of Cr originated from plastic packaging. Finally, several MSW management scenarios showed that most metals are transferred to landfills and the leaching potential of metals to the environment is quite small

  1. Textural and chemical characterizations of adsorbent prepared from palm shell by potassium hydroxide impregnation at different stages.

    Science.gov (United States)

    Guo, Jia; Lua, Aik Chong

    2002-10-15

    Preparation and characterization of activated carbon from palm shell, a carbonaceous agricultural solid waste, by potassium hydroxide treatment at different stages were studied. The effects of activation temperature and chemical to sample ratio on the characteristics of the activated carbon were investigated. Fixed-bed adsorption of sulfur dioxide (SO(2)) gas was carried out to evaluate the adsorptive capacity of the samples. Desorption tests were conducted to verify the occurrence of chemisorption due to some surface functional groups or of chemical reaction between SO(2) and KOH. It was found that pre-impregnation of raw palm shell was involved in replacement of some hydrogen ions with potassium ions to form cross-linked complexes, which retarded the tar formation during carbonization, resulting in a relatively high yield. Moreover, these potassium ions accelerated the reaction as catalysts during gasification of chars by carbon dioxide. For chars with mid-impregnation, potassium hydroxide acted in two ways: (i) formation of metallic potassium by dehydration and (ii) conversion into potassium carbonate. Metallic potassium intercalated to the carbon matrix accounted for pore development and potassium carbonate layer prevented the sample from over burn-off. Post-impregnation of final products modified the textural characteristics of the sample as some pore entrances were blocked by chemicals. However, potassium hydroxide enhanced the amount of SO(2) uptaken via formation of potassium sulfite.

  2. Chemical stabilization of metals in mine wastes by transformed red mud and other iron compounds: laboratory tests.

    Science.gov (United States)

    Ardau, C; Lattanzi, P; Peretti, R; Zucca, A

    2014-01-01

    A series of static and kinetic laboratory-scale tests were designed in order to evaluate the efficacy of transformed red mud (TRM) from bauxite refining residues, commercial zero-valent iron, and synthetic iron (III) hydroxides as sorbents/reagents to minimize the generation of acid drainage and the release of toxic elements from multi-contaminant-laden mine wastes. In particular, in some column experiments the percolation of meteoric water through a waste pile, alternated with periods of dryness, was simulated. Wastes were placed in columns together with sorbents/reagents in three different set-ups: as blended amendment (mixing method), as a bed at the bottom of the column (filtration method), or as a combination of the two previous methods. The filtration methods, which simulate the creation of a permeable reactive barrier downstream of a waste pile, are the most effective, while the use of sorbents/reagents as amendments leads to unsatisfactory results, because of the selective removal of only some contaminants. The efficacy of the filtration method is not significantly affected by the periods of dryness, except for a temporary rise of metal contents in the leachates due to dissolution of soluble salts formed upon evaporation in the dry periods. These results offer original information on advantages/limits in the use of TRM for the treatment of multi-contaminant-laden mine wastes, and represent the starting point for experimentation at larger scale.

  3. Melting decontamination and free release of metal waste at Studsvik RadWaste Co. in Sweden

    International Nuclear Information System (INIS)

    Kawatsuma, Shinji; Ishikawa, Keiji; Matsubara, Tatsuo; Donomae, Yasushi; Imagawa, Yasuhiro

    2006-01-01

    The Studsvik RadWaste Co. in Sweden was visited on August 29, 2005 by members of radioactive waste and decommissioning subgroup of central safety task force in old Japan Nuclear Cycle Development Institute as 'Overseas investigation'. The visit afforded us the chance to survey melting and decontaminating of metallic waste in this company and the status of free release. Domestic and foreign radioactive metallic waste is accepted in this company after 1987, and the majority of the decontaminated waste have been released freely. In the background of the big effort of this company and the strong leadership of the regulator (SSI: Swedish radiation protection Authority), prosperous operation was able to have been achieved. This survey was done based on 'Free release of radioactive metallic waste in Europe: the free release experience for 17 years at Studsvik RadWaste Co. in Sweden' by Dr. J. Lorenzen. (author)

  4. Study of the leaching of heavy metals from waste water sludge and incinerator's ash, using coupled thermostated columns and DTPA as complex agent; Estudio de la extraccion de metales pesados de lodos y cenizas de aguas residuales usando columnas termostatizadas acopladas y DTPA como agente complejante

    Energy Technology Data Exchange (ETDEWEB)

    Vite T, J.; Vite T, M.; Guerrero D, J.; Carreno de Leon, M.C. [Departamento de Estudios del Ambiente, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    We studied the metallic composition from waste water sludge and incinerators ashes of an incinerator located in Toluca, Mexico, the qualitative studies were made using the Activation Analysis technique, and fluorescence X-ray techniques. The quantitative analysis of heavy metals in the wastes were made using Inductively coupled plasma atomic emission spectrometry (Icp-Aes). For leaching the samples, we used four coupled thermostated columns, each one had a p H of 2,5, 7 and 10. The flux of the air was of 1600 cc/min. The temperature was maintain constant in 60 Centigrade using a thermostated system. For this study we used 100 g of wastes mixed with mineral acid or sodium hydroxide to reach p H 2,5,7 and 10. We added a reducing and tensoactive agents and finally DTPA as complex agent. With this method, we obtain a better leaching efficiency using a complex agent. However the high DTPA cost, make this process expansive that is why we recommend to work with another classes of complex agents, that be cheaper to leach metals of different chemistry matrix. (Author)

  5. Method of processing decontaminating liquid waste

    International Nuclear Information System (INIS)

    Kusaka, Ken-ichi

    1989-01-01

    When decontaminating liquid wastes are processed by ion exchange resins, radioactive nuclides, metals, decontaminating agents in the liquid wastes are captured in the ion exchange resins. When the exchange resins are oxidatively deomposed, most of the ingredients are decomposed into water and gaseous carbonic acid and discharged, while sulfur ingredient in the resins is converted into sulfuric acid. In this case, even less oxidizable ingredients in the decontaminating agent made easily decomposable by oxidative decomposition together with the resins. The radioactive nuclides and a great amount of iron dissolved upon decontamination in the liquid wastes are dissolved in sulfuric acid formed. When the sulfuric acid wastes are nuetralized with sodium hydroxide, since they are formed into sodium sulfate, which is most popular as wastes from nuclear facilities, they can be condensated and solidified by existent waste processing systms to thereby facilitate the waste processing. (K.M.)

  6. Luminescent materials based on Tb, Eu-containing layered double hydroxides

    International Nuclear Information System (INIS)

    Zhuravleva, N.G.; Eliseev, A.A.; Lukashin, A.V.; Kinast, U.; Tret'yakov, Yu.D.

    2004-01-01

    Luminescent materials on the basis of magnesium-aluminium layered double hydroxides with intercalated anionic complexes of terbium and europium picolinates were synthesized. Relying on data of spectroscopy, elementary and X-ray phase analyses, the change in the rare earth complex structure and metal/ligand ratio, depending on the hydroxide layer charge, determined by Mg/Al ratio in the double hydroxide, were ascertained. The values of quantum yields of luminescence for terbium-containing samples amounted to 30-50% [ru

  7. Iodine Sequestration Using Delafossites and Layered Hydroxides

    International Nuclear Information System (INIS)

    J.D. Pless; J.B. Chwirka; J.L. Krumhansl

    2006-01-01

    The objective of this document is to report on early success for sequestering 129 I. Sorption coefficients (K d ) for I - and IO 3 - onto delafossites, spinels and layered metal hydroxides were measured in order to compare their applicability for sequestering 129 I. The studies were performed using a dilute fluid composition representative of groundwater indigenous to the Yucca mountain area. Delafossites generally exhibited relatively poor sorption coefficients ( 1.7 mL/g). In contrast, the composition of the layered hydroxides significantly affects their ability to sorb I. Cu/Al and Cu/Cr layered hydroxide samples exhibit K d 's greater than 10 3 mL/g for both I - and IO 3 -

  8. Mining Waste Classification and Quantity of Non-Metal Minesin Slovenia

    Directory of Open Access Journals (Sweden)

    Ana Burger

    2007-06-01

    Full Text Available Mining is an important human activity that creates wealth and supplies materials for maintaining standard of living and further human development. However, mining has also negative impacts on the environment and society. One of them is the production of mining waste throughout the entire mining cycle, in particular in the mine development and operation /production stage.Due to the EU Directive 2006/21/EC on the management of waste from the extractive industries and its implementation in Member state, estimation on quality and quantity of mining waste from active non-metal mines in Slovenia was carried out. In the selected mines mining and processing was closely examined. With material flow analysis quantity and characteristics of mining waste were defined for several mines of different commodities.Data on mining waste were afterwards generalized in order to get an overall country evaluation on mining waste “production” of non-metal mines.Mining waste as a result of mining and beneficiation processes in non-metal mines of Slovenia is either inert or non-hazardous. Most of the mining waste is used for mine reclamation running simultaneously with the production phase. The largest amounts of mining waste per unit produced are created in dimension stone industry. Since the dimensionstone production is small, the waste amount is negligible. Large quantities of mining waste are produced in crushed stone and, sand and gravel operations, because aggregate production is pretty large with regard to other non-metals production in Slovenia. We can therefore conclude that large quantities of mining waste from non-metal mines, which are mostly used in reclamation and for side products, do not represent danger to the environment.

  9. Processing method of radioactive metal wastes

    International Nuclear Information System (INIS)

    Uetake, Naoto; Urata, Megumu; Sato, Masao.

    1985-01-01

    Purpose: To reduce the volume and increase the density of radioactive metal wastes easily while preventing scattering of radioactivity and process them into suitable form to storage and treatment. Method: Metal wastes mainly composed of zirconium are discharged from nuclear power plants or fuel re-processing plants, and these metals such as zirconium and titanium vigorously react with hydrogen and rapidly diffuse as hydrides. Since the hydrides are extremely brittle and can be pulverized easily, they can be volume-reduced. However, since metal hydrides have no ductility, dehydrogenation is applied for the molding fabrication in view of the subsequent storage and processing. The dehydrogenation is easy like the hydrogenation and fine metal pieces can be molded in a small compression device. For the dehydrogenation, a temperature is slightly increased as compared with that in the hydrogenation, pressure is reduced through the vacuum evacuation system and the removed hydrogen is purified for reuse. The upper limit for the temperature of the hydrogenation is 680 0 C in order to prevent the scttering of radioactivity. (Kamimura, M.)

  10. DOE mixed waste metals partition in a rotary kiln wet off-gas system

    International Nuclear Information System (INIS)

    Burns, D.B.; Looper, M.G.

    1994-01-01

    In 1996, the Savannah River Site plans to begin operation of the Consolidated Incineration Facility (CIF) to treat solid and liquid RCRA hazardous and mixed wastes. Test burns were conducted using surrogate CIF wastes spiked with hazardous metals and organics. The partition of metals between the kiln bottom ash, scrubber blowdown solution, and stack gas was measured as a function of kiln temperature, waste chloride content, and waste form (liquid or solid). Three waste simulants were used in these tests, a high and low chloride solid waste mix (paper, plastic, latex, PVC), and a liquid waste mix (benzene and chlorobenzene). An aqueous solution containing: antimony, arsenic, barium, cadmium, chromium, lead, mercury, nickel, silver, and thallium was added to the waste to determine metals fate under various combustion conditions. Test results were used to divide the metals into three general groups, volatile, semi-volatile, and nonvolatile metals. Mercury was the only volatile metal. No mercury remained in the kiln bottom ash under any incineration condition. Lead, cadmium, thallium, and silver exhibited semi-volatile behavior. The partition between the kiln ash, blowdown, and stack gas depended on incineration conditions. Chromium, nickel, barium, antimony, and arsenic exhibited nonvolatile behavior, with greater than 90 wt % of the metal remaining in the kiln bottom ash. Incineration temperature had a significant effect on the partition of volatile and semi-volatile metals, and no effect on nonvolatile metal partition. As incineration temperatures were increased, the fraction of metal leaving the kiln increased. Three metals, lead, cadmium, and mercury showed a relationship between chloride concentration in the waste and metals partition. Increasing the concentration of chlorides in the waste or burning liquid waste versus solid waste resulted in a larger fraction of metal exiting the kiln

  11. Heavy metal vaporization and abatement during thermal treatment of modified wastes

    International Nuclear Information System (INIS)

    Rio, S.; Verwilghen, C.; Ramaroson, J.; Nzihou, A.; Sharrock, P.

    2007-01-01

    This study examines the vaporization percentage and partitioning of heavy metals Cd, Pb and Zn during thermal treatment of wastes with added PVC, heavy metals or phosphate, and the efficiency of sorbents for removal of these metallic compounds in flue gas of an industrial solid waste incinerator. Firstly, vaporization experiments were carried out to determine the behavior of heavy metals during combustion under various conditions (type of waste, temperature, presence of chloride or phosphate ...). The experimental results show relatively high vaporization percentage of metallic compounds within fly ash and limestone matrix while heavy metals within sediments treated with phosphoric acid are less volatile. Vaporization of metals increases with increasing temperature and with chloride addition. The thermal behavior of the selected heavy metals and their removal by sorbents (sodium bicarbonate, activated carbon) was also studied in an industrial solid waste incinerator. These pilot scale experiments confirm that heavy metals are concentrated in fly ashes and cyclone residues, thus effectively controlling their release to the atmosphere

  12. Interfacial engineering of renewable metal organic framework derived honeycomb-like nanoporous aluminum hydroxide with tunable porosity.

    Science.gov (United States)

    Pan, Ye-Tang; Zhang, Lu; Zhao, Xiaomin; Wang, De-Yi

    2017-05-01

    Novel honeycomb-like mesoporous aluminum hydroxide (pATH) was synthesized via a facile one-step reaction by employing ZIF-8 as a template. This self-decomposing template was removed automatically under acidic conditions without the need for any tedious or hazardous procedures. Meanwhile, the pore size of pATH was easily modulated by tuning the dimensions of the ZIF-8 polyhedrons. Of paramount importance was the fact that the dissolved ZIF-8 in solution was regenerated upon deprotonation of the ligand under mild alkali conditions, and was reused in the preparation of pATH, thus forming a delicate synthesis cycle. The renewable template conferred cost-effective and sustainable features to the as-synthesized product. As a proof-of-concept application, the fascinating nanoporous structure enabled pATH to load more phosphorous-containing flame retardant and endowed better interaction with epoxy resin over that of commercial aluminum hydroxide. The limiting oxygen index, UL-94 vertical burning test and cone calorimeter test showed that the results of epoxy with the modified pATH rivalled those of epoxy with two times the loading amount of the commercial counterpart, while the former presented better mechanical properties. The proposed "amorphous replica method" used in this work will advance the potential for launching a vast area of research and technology development for the preparation of porous metal hydroxides for use in practical applications.

  13. Structural transformation of nickel hydroxide films during anodic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Crocker, Robert W. [Univ. of California, Berkeley, CA (United States); Muller, Rolf H. [Univ. of California, Berkeley, CA (United States)

    1992-05-01

    The transformation of anodically formed nickel hydroxide/oxy-hydroxide electrodes has been investigated. A mechanism is proposed for the anodic oxidation reaction, in which the reaction interface between the reduced and oxidized phases of the electrode evolves in a nodular topography that leads to inefficient utilization of the active electrode material. In the proposed nodular transformation model for the anodic oxidation reaction, nickel hydroxide is oxidized to nickel oxy-hydroxide in the region near the metal substrate. Since the nickel oxy-hydroxide is considerably more conductive than the surrounding nickel hydroxide, as further oxidation occurs, nodular features grow rapidly to the film/electrolyte interface. Upon emerging at the electrolyte interface, the reaction boundary between the nickel hydroxide and oxy-hydroxide phases spreads laterally across the film/electrolyte interface, creating an overlayer of nickel oxy-hydroxide and trapping uncharged regions of nickel hydroxide within the film. The nickel oxy-hydroxide overlayer surface facilitates the oxygen evolution side reaction. Scanning tunneling microscopy of the electrode in its charged state revealed evidence of 80 - 100 Angstrom nickel oxy-hydroxide nodules in the nickel hydroxide film. In situ spectroscopic ellipsometer measurements of films held at various constant potentials agree quantitatively with optical models appropriate to the nodular growth and subsequent overgrowth of the nickel oxy-hydroxide phase. A two-dimensional, numerical finite difference model was developed to simulate the current distribution along the phase boundary between the charged and uncharged material. The model was used to explore the effects of the physical parameters that govern the electrode behavior. The ratio of the conductivities of the nickel hydroxide and oxy-hydroxide phases was found to be the dominant parameter in the system.

  14. Structural transformation of nickel hydroxide films during anodic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Crocker, R.W.; Muller, R.H.

    1992-05-01

    The transformation of anodically formed nickel hydroxide/oxy-hydroxide electrodes has been investigated. A mechanism is proposed for the anodic oxidation reaction, in which the reaction interface between the reduced and oxidized phases of the electrode evolves in a nodular topography that leads to inefficient utilization of the active electrode material. In the proposed nodular transformation model for the anodic oxidation reaction, nickel hydroxide is oxidized to nickel oxy-hydroxide in the region near the metal substrate. Since the nickel oxy-hydroxide is considerably more conductive than the surrounding nickel hydroxide, as further oxidation occurs, nodular features grow rapidly to the film/electrolyte interface. Upon emerging at the electrolyte interface, the reaction boundary between the nickel hydroxide and oxy-hydroxide phases spreads laterally across the film/electrolyte interface, creating an overlayer of nickel oxy-hydroxide and trapping uncharged regions of nickel hydroxide within the film. The nickel oxy-hydroxide overlayer surface facilitates the oxygen evolution side reaction. Scanning tunneling microscopy of the electrode in its charged state revealed evidence of 80 {endash} 100 Angstrom nickel oxy-hydroxide nodules in the nickel hydroxide film. In situ spectroscopic ellipsometer measurements of films held at various constant potentials agree quantitatively with optical models appropriate to the nodular growth and subsequent overgrowth of the nickel oxy-hydroxide phase. A two-dimensional, numerical finite difference model was developed to simulate the current distribution along the phase boundary between the charged and uncharged material. The model was used to explore the effects of the physical parameters that govern the electrode behavior. The ratio of the conductivities of the nickel hydroxide and oxy-hydroxide phases was found to be the dominant parameter in the system.

  15. Anaerobic bioleaching of metals from waste activated sludge

    International Nuclear Information System (INIS)

    Meulepas, Roel J.W.; Gonzalez-Gil, Graciela; Teshager, Fitfety Melese; Witharana, Ayoma; Saikaly, Pascal E.; Lens, Piet N.L.

    2015-01-01

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342 μg g −1 of copper, 487 μg g −1 of lead, 793 μg g −1 of zinc, 27 μg g −1 of nickel and 2.3 μg g −1 of cadmium. During the anaerobic acidification of 3 g dry weight L −1 waste activated sludge, 80–85% of the copper, 66–69% of the lead, 87% of the zinc, 94–99% of the nickel and 73–83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead. - Highlights: • Heavy metals were leached during anaerobic acidification of waste activated sludge. • The process does not require the addition of chelating or oxidizing agents. • The metal leaching efficiencies (66 to 99%) were comparable to chemical leaching. • The produced leachate may be used for metal recovery and biogas production. • The produced digested sludge may be used as soil conditioner

  16. Effective self-purification of polynary metal electroplating wastewaters through formation of layered double hydroxides.

    Science.gov (United States)

    Zhou, Ji Zhi; Wu, Yue Ying; Liu, Chong; Orpe, Ajay; Liu, Qiang; Xu, Zhi Ping; Qian, Guang Ren; Qiao, Shi Zhang

    2010-12-01

    Heavy metal ions (Ni(2+), Zn(2+), and Cr(3+)) can be effectively removed from real polynary metal ions-bearing electroplating wastewaters by a carbonation process, with ∼99% of metal ions removed in most cases. The synchronous formation of layered double hydroxide (LDH) precipitates containing these metal ions was responsible for the self-purification of wastewaters. The constituents of formed polynary metals-LDHs mainly depended on the Ni(2+):Zn(2+):Cr(3+) molar ratio in wastewaters. LDH was formed at pH of 6.0-8.0 when the Ni(2+)/Zn(2+) molar ratio ≥ 1 where molar fraction of trivalent metal in the wastewaters was 0.2-0.4, otherwise ZnO, hydrozincite, or amorphous precipitate was observed. In the case of LDH formation, the residual concentration of Ni(2+), Zn(2+), and Cr(3+) in the treated wastewaters was very low, about 2-3, ∼2, and ∼1 mg/L, respectively, at 20-80 °C and pH of 6.0-8.0, indicating the effective incorporation of heavy metal ions into the LDH matrix. Furthermore, the obtained LDH materials were used to adsorb azoic dye GR, with the maximum adsorption amount of 129-134 mg/g. We also found that the obtained LDHs catalyzed more than 65% toluene to decompose at 350 °C under ambient pressure. Thus the current research has not only shown effective recovery of heavy metal ions from the electroplating wastewaters in an environmentally friendly process but also demonstrated the potential utilization of recovered materials.

  17. Gold Nanoparticles on Layered Double Hydroxide Nanosheets and Its Electrocatalysis for Glucose Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Hye Ran; Lee, Jong Hyeon [The Catholic University of Korea, Bucheon (Korea, Republic of); Cho, Se Hee; Ji, Hong Geun [H and A PharmaChem, Bucheon (Korea, Republic of)

    2016-03-15

    We developed a new way to form the well-defined nanocomposite of Au NPs and exfoliated LDH nanosheet by in situ chemical reduction with NaBH{sub 4}. The optical and structural studies indicate that the Au NPs are highly dispersed and immobilized on the surface of LDH nanosheets. The Au/LDH nanosheet exhibited an excellent electrocatalysis toward glucose oxidation reaction. The results strongly demonstrate that the nanoscopic natures and dense positive charges of LDH nanosheet effectively stabilized the Au NPs to maintain their inherent properties during the synthesis and the electrocatalysis. The use of the double hydroxide nanosheets as nanoscopic support materials for the transition-metal NPs will dramatically improve their functionalities in heterogeneous catalysis. Recently, two-dimensional nanosheet of exfoliated layered double hydroxide (LDH) has emerged as a new type of solid support to immobilize the diverse metal NPs because of the large metal hydroxide area, good biochemical stability, and highly charged positive potential of 1- to 2-nm thick LDH layers. LDHs consist of a continuous stack of positively charged metal hydroxide layers with counter anions and water molecules placed in interlayer spaces.

  18. Aluminium hydroxide-the carrier for catalysts coating

    International Nuclear Information System (INIS)

    Normatov, I.Sh.; Mirsaidov, U.M.

    2003-01-01

    At present time several methods of receiving aluminium hydroxide are exist. But all they differ by much staging of process connected with preliminary receiving of intermediate compounds, with application of expensive metallic aluminium

  19. Biosorbents for Removing Hazardous Metals and Metalloids

    Directory of Open Access Journals (Sweden)

    Katsutoshi Inoue

    2017-07-01

    Full Text Available Biosorbents for remediating aquatic environmental media polluted with hazardous heavy metals and metalloids such as Pb(II, Cr(VI, Sb(III and V, and As(III and V were prepared from lignin waste, orange and apple juice residues, seaweed and persimmon and grape wastes using simple and cheap methods. A lignophenol gel such as lignocatechol gel was prepared by immobilizing the catechol functional groups onto lignin from sawdust, while lignosulfonate gel was prepared directly from waste liquor generated during pulp production. These gels effectively removed Pb(II. Orange and apple juice residues, which are rich in pectic acid, were easily converted using alkali (e.g., calcium hydroxide into biosorbents that effectively removed Pb(II. These materials also effectively removed Sb(III and V and As(III and V when these were preloaded with multi-valent metal ions such as Zr(IV and Fe(III. Similar biosorbents were prepared from seaweed waste, which is rich in alginic acid. Other biosorbents, which effectively removed Cr(VI, were prepared by simply treating persimmon and grape wastes with concentrated sulfuric acid.

  20. Review of metal-matrix encapsulation of solidified radioactive high-level waste

    International Nuclear Information System (INIS)

    Jardine, L.J.; Steindler, M.J.

    1978-05-01

    Literature describing previous and current work on the encapsulation of solidified high-level waste forms in a metal matrix was reviewed. Encapsulation of either stabilized calcine pellets or glass beads in alloys by casting techniques was concluded to be the most developed and direct approach to fabricating solid metal-matrix waste forms. Further characterizations of the physical and chemical properties of metal-matrix waste forms are still needed to assess the net attributes of metal-encapsulation alternatives. Steady-state heat transfer properties of waste canisters in air and water environments were calculated for four reference waste forms: (1) calcine, (2) glass monoliths, (3) metal-encapsulated calcine, and (4) metal-encapsulated glass beads. A set of criteria for the maximum allowable canister centerline and surface temperatures and heat generation rates per canister at the time of shipment to a Federal repository was assumed, and comparisons were made between canisters of these reference waste forms of the shortest time after reactor discharge that canisters could be filled and the subsequent ''interim'' storage times prior to shipment to a Federal repository for various canister diameters and waste ages. A reference conceptual flowsheet based on existing or developing technology for encapsulation of stabilized calcine pellets is discussed. Conclusions and recommendations are presented

  1. Development of technique for quantifying gamma emitters in metal waste. New technique of precise and automatic measurements for confirmation of clearance level of metal waste

    International Nuclear Information System (INIS)

    Hattori, Takatoshi

    2002-01-01

    A New technique of precise and automatic measurements of gamma emitters in metal waste has been developed using 3D non-contact shape measurement and monte-carlo calculation techniques in order to confirm that specific radioactivity level of metal waste satisfies the clearance level and furthermore the surface contamination level of the metal waste is below the legal standard level. The technique can give a calibration factor every measurement target automatically and realize an automatic correction for reduction of background count rate in gamma measurements due to self-shield effect of the measurement target. The accuracy of the present method has been made clear using mock-metal wastes with various types of shape, number and size. Assuming the goal of the detection limit for practical use is 25OBq in radioactivity, a concept of the practical gamma monitor has been designed so as to be able to confirm both the clearance level and surface contamination level simultaneously and to cope with the metal waste at a speed of 2-10 ton a day. (author)

  2. Solid-state chelation of metal ions by ethylenediaminetetraacetate intercalated in a layered double hydroxide.

    Science.gov (United States)

    Tarasov, Konstantin A; O'Hare, Dermot; Isupov, Vitaly P

    2003-03-24

    The solid-state chelation of transition metal ions (Co(2+), Ni(2+), and Cu(2+)) from aqueous solutions into the lithium aluminum layered double hydroxide ([LiAl(2)(OH)(6)]Cl x 0.5H(2)O or LDH) which has been pre-intercalated with EDTA (ethylenediaminetetraacetate) ligand has been investigated. The intercalated metal cations form [M(edta)](2)(-) complexes between the LDH layers as indicated by elemental analysis, powder X-ray diffraction, and IR and UV-vis spectroscopies. If metal chloride or nitrate salts are used in the reaction with the LDH then co-intercalation of either the Cl(-) or NO(3)(-) anions is observed. In the case of metal acetate salts the cations intercalate without the accompanying anion. This can be explained by the different intercalation selectivity of the anions in relation to the LDH. In the latter case the introduction of the positive charge into LDH structure was compensated for by the release from the solid of the equivalent quantity of lithium and hydrogen cations. Time-resolved in-situ X-ray diffraction measurements have revealed that the chelation/intercalation reactions proceed very quickly. The rate of the reaction found for nickel acetate depends on concentration as approximately k[Ni(Ac)(2)](3).

  3. Anaerobic bioleaching of metals from waste activated sludge

    Energy Technology Data Exchange (ETDEWEB)

    Meulepas, Roel J.W., E-mail: roel.meulepas@wetsus.nl [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); Gonzalez-Gil, Graciela [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); King Abdullah University of Science and Technology, Water Desalination and Reuse Center, Thuwal 13955-69000 (Saudi Arabia); Teshager, Fitfety Melese; Witharana, Ayoma [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); Saikaly, Pascal E. [King Abdullah University of Science and Technology, Water Desalination and Reuse Center, Thuwal 13955-69000 (Saudi Arabia); Lens, Piet N.L. [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands)

    2015-05-01

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342 μg g{sup −1} of copper, 487 μg g{sup −1} of lead, 793 μg g{sup −1} of zinc, 27 μg g{sup −1} of nickel and 2.3 μg g{sup −1} of cadmium. During the anaerobic acidification of 3 g{sub dry} {sub weight} L{sup −1} waste activated sludge, 80–85% of the copper, 66–69% of the lead, 87% of the zinc, 94–99% of the nickel and 73–83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead. - Highlights: • Heavy metals were leached during anaerobic acidification of waste activated sludge. • The process does not require the addition of chelating or oxidizing agents. • The metal leaching efficiencies (66 to 99%) were comparable to chemical leaching. • The produced leachate may be used for metal recovery and biogas production. • The produced digested sludge may be used as soil conditioner.

  4. Decomposition of vegetation growing on metal mine waste

    Energy Technology Data Exchange (ETDEWEB)

    Williams, S T; McNeilly, T; Wellington, E M.H.

    1977-01-01

    Aspects of the decomposition of metal tolerant vegetation growing on mine waste containing high concentrations of lead and zinc were studied and compared with those on an adjacent uncontaminated site. High concentrations of Pb and, to a lesser extent, Zn, accumulated in metal-tolerant grass. Retarded decomposition of this vegetation as compared with that on the uncontaminated site was indicated by a greater accumulation of litter, less humus formation, reduced soil urease activity and smaller microbial and microfaunal populations. Some evidence for increased metal tolerance in microbes from the mine waste was obtained. Concentrations of lead tolerated under laboratory conditions were much lower than those extracted from the mine waste and its vegetation, probably due to the lack of an accurate method for assessing the availability of lead in soil and vegetation.

  5. BPEO/BPM in recycling of low level waste metal in the UK - 16210

    International Nuclear Information System (INIS)

    Dodd, Kevin; Robinson, Joe; Lindberg, Maria

    2009-01-01

    Best Practicable Environmental Option (BPEO) and Best Practicable Means (BPM) are concepts well established in the nuclear industry to help guide and inform waste management decision making. The recycling of contaminated metal waste in the UK is not well established, with the majority of waste disposed of at the Low Level Waste Repository (LLWR) at Drigg. This paper presents an overview of the Strategic BPEO study completed by Studsvik examining the options for low level metal waste management and a subsequent BPM study completed in support of a proposed metals recycling service. The environmental benefits of recycling metals overseas is further examined through the application of life cycle analysis to the metals recycling process. The methodologies used for both studies are discussed and the findings of these studies presented. These indicate that recycling contaminated metal is the preferred option, using overseas facilities until UK facilities are available. The BPM for metals recycling is discussed in detail and indicates that a tool box for processing metal waste is required to ensure BPM is applied on a case by case basis. This is supported by effective management of waste transport and waste acceptance criteria. Whilst the transport of contaminated metal overseas for treatment adds to the environmental burden of metals recycling, this when compared with the production of virgin metal, is shown to remain beneficial. The results of the Studsvik studies demonstrate the benefits of recycling metals, the options available for such a service and challenges that remain. (authors)

  6. Characterizing the environmental impact of metals in construction and demolition waste.

    Science.gov (United States)

    Yu, Danfeng; Duan, Huabo; Song, Qingbin; Li, Xiaoyue; Zhang, Hao; Zhang, Hui; Liu, Yicheng; Shen, Weijun; Wang, Jinben

    2018-05-01

    Large quantities of construction and demolition (C&D) waste are generated in China every year, but their potential environmental impacts on the surrounding areas are rarely assessed. This study focuses on metals contained in C&D waste, characterizing the metal concentrations and their related environmental risks. C&D waste samples were collected in Shenzhen City, China, from building demolition sites, renovation areas undergoing refurbishment, landfill sites, and recycling companies (all located in Shenzhen city) that produce recycled aggregate, in order to identify pollution levels of the metals As, Cd, Cr, Cu, Pb, Ni, and Zn. The results showed that (1) the metal concentrations in most demolition and renovation waste samples were below the soil environmental quality standard for agricultural purposes (SQ-Agr.) in China; (2) Cd, Cu, and Zn led to relatively higher environmental risks than other metals, especially for Zn (DM5 tile sample, 360 mg/kg; R4 tile sample, 281 mg/kg); (3) non-inert C&D waste such as wall insulation and foamed plastic had high concentrations of As and Cd, so that these materials required special attention for sound waste management; and (4) C&D waste collected from landfill sites had higher concentrations of Cd and Cu than did waste collected from demolition and refurbishment sites.

  7. Methods for recovering metals from electronic waste, and related systems

    Science.gov (United States)

    Lister, Tedd E; Parkman, Jacob A; Diaz Aldana, Luis A; Clark, Gemma; Dufek, Eric J; Keller, Philip

    2017-10-03

    A method of recovering metals from electronic waste comprises providing a powder comprising electronic waste in at least a first reactor and a second reactor and providing an electrolyte comprising at least ferric ions in an electrochemical cell in fluid communication with the first reactor and the second reactor. The method further includes contacting the powders within the first reactor and the second reactor with the electrolyte to dissolve at least one base metal from each reactor into the electrolyte and reduce at least some of the ferric ions to ferrous ions. The ferrous ions are oxidized at an anode of the electrochemical cell to regenerate the ferric ions. The powder within the second reactor comprises a higher weight percent of the at least one base metal than the powder in the first reactor. Additional methods of recovering metals from electronic waste are also described, as well as an apparatus of recovering metals from electronic waste.

  8. Bio-extraction of precious metals from urban solid waste

    Science.gov (United States)

    Das, Subhabrata; Natarajan, Gayathri; Ting, Yen-Peng

    2017-01-01

    Reduced product lifecycle and increasing demand for electronic devices have resulted in the generation of huge volumes of electronic waste (e-waste). E-wastes contain high concentrations of toxic heavy metals, which have detrimental effects on health and the environment. However, e-wastes also contain significant concentrations of precious metals such as gold, silver and palladium, which can be a major driving force for recycling of urban waste. Cyanogenic bacteria such as Chromobacterium violaceum generate cyanide as a secondary metabolite which mobilizes gold into solution via a soluble gold-cyanide complex. However, compared to conventional technology for metal recovery, this approach is not effective, owing largely to the low concentration of lixiviants produced by the bacteria. To overcome the challenges of bioleaching of gold from e-waste, several strategies were adopted to enhance gold recovery rates. These included (i) pretreatment of e-waste to remove competing metal ions, (ii) mutation to adapt the bacteria to high pH environment, (iii) metabolic engineering to produce higher cyanide lixiviant, and (iv) spent medium leaching with adjusted initial pH. Compared to 7.1 % recovery by the wild type bacteria, these strategies achieved gold recoveries of 11.3%, 22.5%, 30% and 30% respectively at 0.5% w/v pulp density respectively. Bioleached gold was finally mineralized and precipitated as gold nanoparticles using the bacterium Delftia acidovorans. This study demonstrates the potential for enhancement of biocyanide production and gold recovery from electronic waste through different strategies, and extraction of solid gold from bioleached leachate.

  9. Recovery of sodium hydroxide and silica from zirconium oxide plant effluent of Nuclear Fuel Complex

    International Nuclear Information System (INIS)

    Bajpai, M.B.; Shenoi, M.R.K.; Keni, V.S.

    1994-01-01

    Sodium hydroxide (lye) and silica can be recovered in pure form from the alkaline sodium silicate waste of Nuclear Fuel Complex, Hyderabad. Electrolytic method was used to amalgamate the sodium present in an electrolyser with flowing mercury as cathode and nickel as anode. The amalgam is then denuded with water in a graphite packed tower to recover mercury for recycling to the electrolyser and sodium hydroxide lye. Sodium hydroxide lye can be recycled in the zirconium oxide plant. Silica is recovered from the spent electrolyte by ion exchange method using cation exchange resin. Both the process details are described in this paper, with experimental data useful for the scale up. The process converts waste to value products. (author)

  10. Geopolymers with a high percentage of bottom ash for solidification/immobilization of different toxic metals

    International Nuclear Information System (INIS)

    Boca Santa, Rozineide A. Antunes; Soares, Cíntia; Riella, Humberto Gracher

    2016-01-01

    Highlights: • Geopolymers from bottom ash and metakaolin (BA/M). • Solidification/immobilization (S/I) waste of heavy metals. • Activators: Sodium hydroxide (NaOH), potassium hydroxide (KOH) and sodium silicate (Na 2 SiO 3 ). - Abstract: Geopolymers are produced using alkali-activated aluminosilicates, either as waste or natural material obtained from various sources. This study synthesized geopolymers from bottom ash and metakaolin (BA/M) in a 2:1 wt ratio to test the solidification/immobilization (S/I) properties of heavy metals in geopolymer matrices, since there is very little research using BA in this type of matrices. Therefore, a decision was made to use more than 65% of BA in geopolymer synthesis with and without the addition of heavy metals. The S/I tests with metals used 10, 15 and 30 ml of a waste solution after pickling of printed circuit boards containing metals, including Pb, Cr, Cu, Fe, Sn, As and Ni, in different proportions. As alkali activator, the NaOH and KOH were used in the concentrations of 8 and 12 M in the composition of Na 2 SiO 3 in 1:2 vol ratios. To test S/I efficiency, tests were conducted to obtain the leached and solubilized extract. The analysis was carried out through X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Scanning Electron Microscope (SEM), Energy-Dispersive X-Ray Spectroscopy (EDS) and compressive strength tests. The geopolymer showed a high degree of S/I of the metals; in some samples, the results reached nearly 100%.

  11. Geopolymers with a high percentage of bottom ash for solidification/immobilization of different toxic metals

    Energy Technology Data Exchange (ETDEWEB)

    Boca Santa, Rozineide A. Antunes, E-mail: roosebs@gmail.com; Soares, Cíntia; Riella, Humberto Gracher

    2016-11-15

    Highlights: • Geopolymers from bottom ash and metakaolin (BA/M). • Solidification/immobilization (S/I) waste of heavy metals. • Activators: Sodium hydroxide (NaOH), potassium hydroxide (KOH) and sodium silicate (Na{sub 2}SiO{sub 3}). - Abstract: Geopolymers are produced using alkali-activated aluminosilicates, either as waste or natural material obtained from various sources. This study synthesized geopolymers from bottom ash and metakaolin (BA/M) in a 2:1 wt ratio to test the solidification/immobilization (S/I) properties of heavy metals in geopolymer matrices, since there is very little research using BA in this type of matrices. Therefore, a decision was made to use more than 65% of BA in geopolymer synthesis with and without the addition of heavy metals. The S/I tests with metals used 10, 15 and 30 ml of a waste solution after pickling of printed circuit boards containing metals, including Pb, Cr, Cu, Fe, Sn, As and Ni, in different proportions. As alkali activator, the NaOH and KOH were used in the concentrations of 8 and 12 M in the composition of Na{sub 2}SiO{sub 3} in 1:2 vol ratios. To test S/I efficiency, tests were conducted to obtain the leached and solubilized extract. The analysis was carried out through X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Scanning Electron Microscope (SEM), Energy-Dispersive X-Ray Spectroscopy (EDS) and compressive strength tests. The geopolymer showed a high degree of S/I of the metals; in some samples, the results reached nearly 100%.

  12. Mixed waste treatment with a mediated electrochemical process

    International Nuclear Information System (INIS)

    Hickman, R.G.; Gray, L.W.; Chiba, Z.

    1991-01-01

    The process described in this paper is intended to convert mixed waste containing toxic organic compounds (not heavy metals) to ordinary radioactive waste, which is treatable. The process achieves its goal by oxidizing hydrocarbons to CO 2 and H 2 O. Other atoms that may be present in the toxic organic generally are converted to nonhazardous anions such as sulfate and phosphate. This electro chemical conversion is performed at conditions of temperature and pressure that are just moderately above ambient conditions. Gaseous hydroxides and oxyhydroxides that are formed by many radionuclides during incineration cannot form in this process. 1 ref., 3 figs

  13. Review and evaluation of metallic TRU nuclear waste consolidation methods

    International Nuclear Information System (INIS)

    Montgomery, D.R.; Nesbitt, J.F.

    1983-08-01

    The US Department of Energy established the Commercial Waste Treatment Program to develop, demonstrate, and deploy waste treatment technology. In this report, viable methods are identified that could consolidate the volume of metallic wastes generated in a fuel reprocessing facility. The purpose of this study is to identify, evaluate, and rate processes that have been or could be used to reduce the volume of contaminated/irradiated metallic waste streams and to produce an acceptable waste form in a safe and cost-effective process. A technical comparative evaluation of various consolidation processes was conducted, and these processes were rated as to the feasibility and cost of producing a viable product from a remotely operated radioactive process facility. Out of the wide variety of melting concepts and consolidation systems that might be applicable for consolidating metallic nuclear wastes, the following processes were selected for evaluation: inductoslay melting, rotating nonconsumable electrode melting, plasma arc melting, electroslag melting with two nonconsumable electrodes, vacuum coreless induction melting, and cold compaction. Each process was evaluated and rated on the criteria of complexity of process, state and type of development required, safety, process requirements, and facility requirements. It was concluded that the vacuum coreless induction melting process is the most viable process to consolidate nuclear metallic wastes. 11 references

  14. Method of solidifying radioactive wastes

    International Nuclear Information System (INIS)

    Tomita, Toshihide; Minami, Yuji; Matsuura, Hiroyuki; Kageyama, Hisashi; Kobori, Junzo.

    1984-01-01

    Purpose: To perform the curing sufficiently even when copper hydroxide that interferes the curing reaction is contained in radioactive wastes. Method: Solidification of radioactive wastes containing copper hydroxide using thermoset resins is carried out under the presence of an alkaline material. The thermoset resin used herein is an polyester resin comprising unsaturated polyester and a polymerizable monomer. The alkaline substance usable herein can include powder or an aqueous solution of hydroxides or oxides of sodium, magnesium, calcium or the like. (Yoshino, Y.)

  15. Biosorbents for Removing Hazardous Metals and Metalloids †

    Science.gov (United States)

    Inoue, Katsutoshi; Parajuli, Durga; Ghimire, Kedar Nath; Biswas, Biplob Kumar; Kawakita, Hidetaka; Oshima, Tatsuya; Ohto, Keisuke

    2017-01-01

    Biosorbents for remediating aquatic environmental media polluted with hazardous heavy metals and metalloids such as Pb(II), Cr(VI), Sb(III and V), and As(III and V) were prepared from lignin waste, orange and apple juice residues, seaweed and persimmon and grape wastes using simple and cheap methods. A lignophenol gel such as lignocatechol gel was prepared by immobilizing the catechol functional groups onto lignin from sawdust, while lignosulfonate gel was prepared directly from waste liquor generated during pulp production. These gels effectively removed Pb(II). Orange and apple juice residues, which are rich in pectic acid, were easily converted using alkali (e.g., calcium hydroxide) into biosorbents that effectively removed Pb(II). These materials also effectively removed Sb(III and V) and As(III and V) when these were preloaded with multi-valent metal ions such as Zr(IV) and Fe(III). Similar biosorbents were prepared from seaweed waste, which is rich in alginic acid. Other biosorbents, which effectively removed Cr(VI), were prepared by simply treating persimmon and grape wastes with concentrated sulfuric acid. PMID:28773217

  16. Method of processing radioactive metal wastes

    International Nuclear Information System (INIS)

    Inoue, Yoichi; Kitagawa, Kazuo; Tsuzura, Katsuhiko.

    1980-01-01

    Purpose: To enable long and safety storage for radioactive metal wastes such as used fuel cans after the procession or used pipe, instruments and the likes polluted with various radioactive substances, by compacting them to solidify. Method: Metal wastes such as used fuel cans, which have been cut shorter and reprocessed, are pressed into generally hexagonal blocks. The block is charged in a capsule of a hexagonal cross section made of non-gas permeable materials such as soft steels, stainless steels and the likes. Then, the capsule is subjected to static hydraulic hot pressing as it is or after deaeration and sealing. While various combinations are possible for temperature, pressure and time as the conditions for the static hydraulic hot pressing, dense block with no residual gas pores can be obtained, for example, under the conditions of 900 0 C, 1000 Kg/cm 2 and one hour where the wastes are composed of zircaloy. (Kawakami, Y.)

  17. Option managing for radioactive metallic waste from the decommissioning of Kori Unit 1

    Energy Technology Data Exchange (ETDEWEB)

    Kessel, David S.; Kim, Chagn Lak [KEPCO International Nuclear Graduate School (KINGS), Ulsan (Korea, Republic of)

    2017-06-15

    The purpose of this paper is to evaluate several leading options for the management of radioactive metallic waste against a set of general criteria including safety, cost effectiveness, radiological dose to workers and volume reduction. Several options for managing metallic waste generated from decommissioning are evaluated in this paper. These options include free release, controlled reuse, and direct disposal of radioactive metallic waste. Each of these options may involve treatment of the metal waste for volume reduction by physical cutting or melting. A multi-criteria decision analysis was performed using the Analytic Hierarchy Process (AHP) to rank the options. Melting radioactive metallic waste to produce metal ingots with controlled reuse or free release is found to be the most effective option.

  18. Technology Readiness Evaluation For Aluminum Removal And Sodium Hydroxide Regenration From Hanford Tank Waste By Lithium Hydrotalcite Precipitation

    International Nuclear Information System (INIS)

    Sams, T.L.; Massie, H.L.

    2011-01-01

    A Technology Readiness Evaluation (TRE) performed by AREV A Federal Services, LLC (AFS) for Washington River Protection Solutions, LLC (WRPS) shows the lithium hydrotalcite (LiHT) process invented and patented (pending) by AFS has reached an overall Technology Readiness Level (TRL) of 3. The LiHT process removes aluminum and regenerates sodium hydroxide. The evaluation used test results obtained with a 2-L laboratory-scale system to validate the process and its critical technology elements (CTEs) on Hanford tank waste simulants. The testing included detailed definition and evaluation for parameters of interest and validation by comparison to analytical predictions and data quality objectives for critical subsystems. The results of the TRE would support the development of strategies to further mature the design and implementation of the LiHT process as a supplemental pretreatment option for Hanford tank waste.

  19. Decontamination of alpha contaminated metallic waste by cerium IV redox process

    International Nuclear Information System (INIS)

    Shah, J.G.; Dhami, P.S.; Gandhi, P.M.; Wattal, P.K.

    2012-01-01

    Decontamination of alpha contaminated metallic waste is an important aspect in the management of waste generated during dismantling and decommissioning of nuclear facilities. Present work on cerium redox process targets decontamination of alpha contaminated metallic waste till it qualifies for the non alpha waste category for disposal in near surface disposal facility. Recovery of the alpha radio nuclides and cerium from aqueous secondary waste streams was also studied deploying solvent extraction process and established. The alpha-lean secondary waste stream has been immobilised in cement based matrix for final disposal. (author)

  20. Recovery of sodium hydroxide and silica from zirconium oxide plant effluent of Nuclear Fuel Complex

    Energy Technology Data Exchange (ETDEWEB)

    Bajpai, M B; Shenoi, M R.K.; Keni, V S [Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    Sodium hydroxide (lye) and silica can be recovered in pure form from the alkaline sodium silicate waste of Nuclear Fuel Complex, Hyderabad. Electrolytic method was used to amalgamate the sodium present in an electrolyser with flowing mercury as cathode and nickel as anode. The amalgam is then denuded with water in a graphite packed tower to recover mercury for recycling to the electrolyser and sodium hydroxide lye. Sodium hydroxide lye can be recycled in the zirconium oxide plant. Silica is recovered from the spent electrolyte by ion exchange method using cation exchange resin. Both the process details are described in this paper, with experimental data useful for the scale up. The process converts waste to value products. (author). 3 figs., 2 tabs.

  1. Anaerobic bioleaching of metals from waste activated sludge

    KAUST Repository

    Meulepas, Roel J W; Gonzalez-Gil, Graciela; Teshager, Fitfety Melese; Witharana, Ayoma; Saikaly, Pascal; Lens, Piet Nl L

    2015-01-01

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether

  2. Sodium to sodium carbonate conversion process

    Science.gov (United States)

    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.

  3. Anaerobic bioleaching of metals from waste activated sludge

    KAUST Repository

    Meulepas, Roel J W

    2015-05-01

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342μgg-1 of copper, 487μgg-1 of lead, 793μgg-1 of zinc, 27μgg-1 of nickel and 2.3μgg-1 of cadmium. During the anaerobic acidification of 3gdry weightL-1 waste activated sludge, 80-85% of the copper, 66-69% of the lead, 87% of the zinc, 94-99% of the nickel and 73-83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead.

  4. Recovery of technetium from nuclear fuel wastes

    International Nuclear Information System (INIS)

    Carlin, W.W.

    1975-01-01

    Technetium is removed from aqueous, acidic waste solutions. The acidic waste solution is mixed with a flocculant, e.g., an alkaline earth metal hydroxide or oxide, to precipitate certain fission products. Technetium remains in solution and in the resulting supernatant alkaline aqueous phase. The supernatant alkaline aqueous phase is made acidic and electrolyzed in an electrolytic cell under controlled cathodic potential conditions to deposit technetium on the cathode. Elemental technetium is removed from the cathode. Technetium is separated from other plated fission product metals by extraction from an alkaline solution with an organic extractant, such as pyridine, having affinity for technetium. Technetium is separated from the organic extractant by steam distillation and the resulting aqueous phase treated with ammoniacal reagent to precipitate technetium as ammonium pertechnetate. The precipitate may be acidified to form an aqueous acidic solution of fission product metal values and the solution electrolyzed in an electrolytic cell under controlled cathodic potential conditions and at a potential sufficiently negative to plate out from the solution those fission product metals desired. The metal deposit is stripped from the cathode and stored until its radioactivity has diminished. (U.S.)

  5. Metallic elements occurrences within metallic fragments in the municipal waste incineration bottom ash

    Science.gov (United States)

    Kowalski, Piotr; Kasina, Monika; Michalik, Marek

    2017-04-01

    Bottom ash (BA) from municipal solid waste incineration (MSWI) is composed of grainy ash material, residual components and metallic fragments (from few µm up to 3-5 cm). Its mineral and chemical composition is related to the composition of the waste stream in the incinerator operational area. Wide use of thermal techniques in management of solid waste makes important the studies on valuable components and their distribution within the material in terms of their further processing. By using various valorization or extraction techniques it is possible to extend the range of its possible further application. To investigate metallic elements distribution within metallic fragments of the MSWI BA material produced in municipal waste incineration plant in Poland were collected in 2015 and 2016. BA and its components were investigated using spectroscopic methods of chemical analysis: ICP-OES, ICP-MS, LECO and EDS (used for microanalysis during SEM observations). BA is a material rich in Si (22.5 wt%), Ca (13.4 wt%), Fe (4 wt%), Al (5.2 wt%) and Na (3.5 wt%), composed of equal part of amorphous (silicate glass dominated) and crystalline phase (rich in silicates, aluminosilicates, oxides of non- and metallic elements and sulphates). The content of metallic elements (Al, Fe, Mg, Ti, Mn, Cr, Ni, Sc, Mo, Cu, Pb, Zn, Sn) is 11.5 wt% with domination of Al (5.2 wt%) and Fe (4 wt%) and elevated values of Mg (1 wt%), Ti (0.54 wt%), Cu (0.26 wt%) and Zn (0.27 wt%) (Kowalski et al., 2016). They were mostly concentrated in the form of metallic fragments, mainly as metallic inclusions in the size of 1-20 µm and separated metallic grains in the size of 50-300 µm. Metallic fragments present in the BA are characterized by their composition heterogeneity and various oxygen content. Fragments are rarely composed of single metallic element and usually in their composition up to few main elements dominated over others. The most common were Fe-, Al- and Zn-rich fragments forming respectively

  6. Sodium Hydroxide and Calcium Hydroxide Hybrid Oxygen Bleaching with System

    Science.gov (United States)

    Doelle, K.; Bajrami, B.

    2018-01-01

    This study investigates the replacement of sodium hydroxide in the oxygen bleaching stage using a hybrid system consisting of sodium hydroxide calcium hydroxide. Commercial Kraft pulping was studied using yellow pine Kraft pulp obtained from a company in the US. The impact of sodium hydroxide, calcium hydroxide hybrid system in regard to concentration, reaction time and temperature for Kraft pulp was evaluated. The sodium hydroxide and calcium hydroxide dosage was varied between 0% and 15% based on oven dry fiber content. The bleaching reaction time was varied between 0 and 180 minutes whereas the bleaching temperature ranged between 70 °C and 110 °C. The ability to bleach pulp was measured by determining the Kappa number. Optimum bleaching results for the hybrid system were achieved with 4% sodium hydroxide and 2% calcium hydroxide content. Beyond this, the ability to bleach pulp decreased.

  7. Solidifications/stabilization treatability study of a mixed waste sludge

    International Nuclear Information System (INIS)

    Spence, R.D.; Stine, E.F.

    1996-01-01

    The Department of Energy Oak Ridge Operations Office signed a Federal Facility Compliance Agreement with the US Environmental Protection Agency Region IV regarding mixed wastes from the Oak Ridge Reservation (ORR) subject to the land disposal restriction provisions of the Resource Conservation and Recovery Act (RCRA). This agreement required treatability studies of solidification/stabilization (S/S) on mixed wastes from the ORR. This paper reports the results of the cementitious S/S studies conducted on a waste water treatment sludge generated from biodenitrification and heavy metals precipitation. For the cementitious waste forms, the additives tested were Portland cement, ground granulated blast furnace slag, Class F fly ash, and perlite. The properties measured on the treated waste were density, free-standing liquid, unconfined compressive strength, and TCLP performance. Spiking up to 10,000, 10,000, and 4,400 mg/kg of nickel, lead, and cadmium, respectively, was conducted to test waste composition variability and the stabilization limitations of the binding agents. The results indicated that nickel, lead and cadmium were stabilized fairly well in the high pH hydroxide-carbonate- ''bug bones'' sludge, but also clearly confirmed the established stabilization potential of cementitious S/S for these RCRA metals

  8. Metals partitioning resulting from rotary kiln incineration of hazardous waste

    International Nuclear Information System (INIS)

    Richards, M.K.; Fournier, D.J. Jr.

    1992-01-01

    In response to the need for date on the partitioning of trace metals from hazardous waste incinerators, an extensive series of test was conducted in the summer of 1991 at the USEPA Incineration Research Facility (IRF) in Jefferson, Arkansas. These tests were conducted in the IRF's rotary kiln incinerator system (RKS) equipped with a pilot-scale Calvert Flux-Force/Condensation scrubber as the primary air pollution control system (APCS). The purpose of this test series was to extend the data base on trace metal partitioning and to investigate the effects of variations in incinerator operation on metal partitioning. Another objective was to evaluate the effectiveness of the scrubber for collecting flue gas metals. This series is a continuation of an ongoing IRF research program investigating trace metal partitioning and APCS collection efficiencies. Two previous test series were conducted using the RKS equipped with a venturi/packed-column scrubber and a single-state ionizing wet scrubber. The primary objective of this test series was to determine the fate of six hazardous and four nonhazardous trace metals fed to the RKS in a synthetic, organic-contaminated solid waste matrix. The six hazardous trace metals used were arsenic, barium, cadmium, chromium, mercury, and lead. The four nonhazardous trace metals--bismuth, copper, magnesium, and strontium--were included primarily to supply data to evaluate their potential for use as surrogates. The temperature, waste feed chlorine content, and scrubber pressure drop. The test program objectives were to identify. The partitioning of metals among kiln ash, scrubber liquor, and flue gas. Changes in metal partitioning related to variations in kiln exit gas temperature and waste feed chlorine content. The efficiency of the Calvert scrubber for collecting flue gas metals. The effects of scrubber pressure drop on metal collection efficiencies. 2 figs., 2 tabs

  9. Fire testing of 55 gallon metal waste drums for dry waste storage

    International Nuclear Information System (INIS)

    Hasegawa, H.K.; Staggs, K.J.; Doughty, S.M.

    1993-07-01

    The primary goal of this test program was to conduct a series of fire test to provide information on the fire performance of 55 gallon metal waste drums used for solid waste disposal at Department Of Energy (DOE) facilities. This program was limited in focus to three different types of 55 gallon drums, one radiant heat source, and one specific fire size. The initial test was a single empty 55 gallon drum exposed to a standard ASTME-119 time temperature curve for over 10 minutes. The full scale tests involved metal drums exposed to a 6' diameter flammable liquid fire for a prescribed period of time. The drums contained simulated dry waste materials of primarily class A combustibles. The test results showed that a conventional 55 gallon drum with a 1in. bung would blow its lid consistently

  10. Heavy metal content of combustible municipal solid waste in Denmark.

    Science.gov (United States)

    Riber, Christian; Fredriksen, Gry S; Christensen, Thomas H

    2005-04-01

    Data on the heavy metal composition of outlets from Danish incinerators was used to estimate the concentration of Zn, Cu, Pb, Cr, Ni, Cd, As and Hg in combustible waste (wet as received) at 14 Danish incinerators, representing about 80% of the waste incinerated in Denmark. Zn (1020 mg kg(-1)), Cu (620 mg kg(-1)) and Pb (370 mg kg(-1)) showed the highest concentration, whereas Hg (0.6 mg kg(-1)) showed the lowest concentration. The variation among the incinerators was in most cases within a factor of two to three, except for Cr that in two cases showed unexplained high concentrations. The fact that the data represent many incinerators and, in several cases, observations from a period of 4 to 5 years provides a good statistical basis for evaluating the content of heavy metals in combustible Danish waste. Such data may be used for identifying incinerators receiving waste with high concentrations of heavy metals suggesting the introduction of source control, or, if repeated in time, the data must also be used for monitoring the impacts of national regulation controlling heavy metals. It is recommended that future investigations consider the use of sample digestion methods that ensure complete digestion in order to use the data for determining the total heavy metal content of waste.

  11. The suitability of a supersulfated cement for nuclear waste immobilisation

    International Nuclear Information System (INIS)

    Collier, N.C.; Milestone, N.B.; Gordon, L.E.; Ko, S.-C.

    2014-01-01

    Highlights: • We investigate a supersulfated cement for use as a nuclear waste encapsulant. • High powder fineness requires a high water content to satisfy flow requirements. • Heat generation during hydration is similar to a control cement paste. • Typical hydration products are formed resulting in a high potential for waste ion immobilisation. • Paste pH and aluminium corrosion is less than in a control cement paste. - Abstract: Composite cements based on ordinary Portland cement are used in the UK as immobilisation matrices for low and intermediate level nuclear wastes. However, the high pore solution pH causes corrosion of some metallic wastes and undesirable expansive reactions, which has led to alternative cementing systems being examined. We have investigated the physical, chemical and microstructural properties of a supersulfated cement in order to determine its applicability for use in nuclear waste encapsulation. The hardened supersulfated cement paste appeared to have properties desirable for use in producing encapsulation matrices, but the high powder specific surface resulted in a matrix with high porosity. Ettringite and calcium silicate hydrate were the main phases formed in the hardened cement paste and anhydrite was present in excess. The maximum rate of heat output during hydration of the supersulfated cement paste was slightly higher than that of a 9:1 blastfurnace slag:ordinary Portland cement paste commonly used by the UK nuclear waste processing industry, although the total heat output of the supersulfated cement paste was lower. The pH was also significantly lower in the supersulfated cement paste. Aluminium hydroxide was formed on the surface of aluminium metal encapsulated in the cement paste and ettringite was detected between the aluminium hydroxide and the hardened cement paste

  12. The suitability of a supersulfated cement for nuclear waste immobilisation

    Energy Technology Data Exchange (ETDEWEB)

    Collier, N.C., E-mail: nick.collier@sheffield.ac.uk [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom); Milestone, N.B. [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom); Callaghan Innovation, 69 Gracefield Road, PO Box 31310, Lower Hutt 5040 (New Zealand); Gordon, L.E. [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom); Geopolymer and Minerals Processing Group, Department of Chemical and Biomolecular Engineering, University of Melbourne, Parkville, Victoria 3010 (Australia); Ko, S.-C. [Holcim Technology Ltd, Hagenholzstrasse 85, CH-8050 Zurich (Switzerland)

    2014-09-15

    Highlights: • We investigate a supersulfated cement for use as a nuclear waste encapsulant. • High powder fineness requires a high water content to satisfy flow requirements. • Heat generation during hydration is similar to a control cement paste. • Typical hydration products are formed resulting in a high potential for waste ion immobilisation. • Paste pH and aluminium corrosion is less than in a control cement paste. - Abstract: Composite cements based on ordinary Portland cement are used in the UK as immobilisation matrices for low and intermediate level nuclear wastes. However, the high pore solution pH causes corrosion of some metallic wastes and undesirable expansive reactions, which has led to alternative cementing systems being examined. We have investigated the physical, chemical and microstructural properties of a supersulfated cement in order to determine its applicability for use in nuclear waste encapsulation. The hardened supersulfated cement paste appeared to have properties desirable for use in producing encapsulation matrices, but the high powder specific surface resulted in a matrix with high porosity. Ettringite and calcium silicate hydrate were the main phases formed in the hardened cement paste and anhydrite was present in excess. The maximum rate of heat output during hydration of the supersulfated cement paste was slightly higher than that of a 9:1 blastfurnace slag:ordinary Portland cement paste commonly used by the UK nuclear waste processing industry, although the total heat output of the supersulfated cement paste was lower. The pH was also significantly lower in the supersulfated cement paste. Aluminium hydroxide was formed on the surface of aluminium metal encapsulated in the cement paste and ettringite was detected between the aluminium hydroxide and the hardened cement paste.

  13. Isolation of Metals from Liquid Wastes: Reactive in Turbulent Thermal Reactors

    International Nuclear Information System (INIS)

    Wendt, Jost O.L.

    2001-01-01

    A Generic Technology for treatment of DOE Metal-Bearing Liquid Waste The DOE metal-bearing liquid waste inventory is large and diverse, both with respect to the metals (heavy metals, transuranics, radionuclides) themselves, and the nature of the other species (annions, organics, etc.) present. Separation and concentration of metals is of interest from the standpoint of reducing the volume of waste that will require special treatment or isolation, as well as, potentially, from the standpoint of returning some materials to commerce by recycling. The variety of metal-bearing liquid waste in the DOE complex is so great that it is unlikely that any one process (or class of processes) will be suitable for all material. However, processes capable of dealing with a wide variety of wastes will have major advantages in terms of process development, capital, and operating costs, as well as in environmental and safety permitting. Moreover, to the extent that a process operates well with a variety of metal-bearing liquid feedwastes, its performance is likely to be relatively robust with respect to the inevitable composition variations in each waste feed. One such class of processes involves high-temperature treatment of atomized liquid waste to promote reactive capture of volatile metallic species on collectible particulate substrates injected downstream of a flame zone. Compared to low-temperature processes that remove metals from the original liquid phase by extraction, precipitation, ion exchange, etc., some of the attractive features of high-temperature reactive scavenging are: The organic constituents of some metal-bearing liquid wastes (in particular, some low-level mixed wastes) must be treated thermally in order to meet the requirements of the Resource Conservation and Recovery Act (RCRA) and Toxic Substances Control Act (TSCA), and the laws of various states. No species need be added to an already complex liquid system. This is especially important in light of the fact

  14. Immobilization with Metal Hydroxides as a Means To Concentrate Food-Borne Bacteria for Detection by Cultural and Molecular Methods†

    OpenAIRE

    Lucore, Lisa A.; Cullison, Mark A.; Jaykus, Lee-Ann

    2000-01-01

    The application of nucleic acid amplification methods to the detection of food-borne pathogens could be facilitated by concentrating the organisms from the food matrix before detection. This study evaluated the utility of metal hydroxide immobilization for the concentration of bacterial cells from dairy foods prior to detection by cultural and molecular methods. Using reconstituted nonfat dry milk (NFDM) as a model, two food-borne pathogens (Listeria monocytogenes and Salmonella enterica sero...

  15. Treatment and minimization of heavy metal-containing wastes 1995

    International Nuclear Information System (INIS)

    Hager, J.P.; Mishra, B.; Litz, J.L.

    1995-01-01

    This symposium was held in conjunction with the 1995 Annual Meeting of the Minerals, Metals and Materials Society in Las Vegas, Nevada, February 12--16, 1995. The purpose of this meeting was to provide a forum for exchange of state-of-the-art information on treating and minimizing heavy metal-containing wastes. Papers were categorized under the following broad headings: aqueous processing; waste water treatment; thermal processing and stabilization; processing of fly ash, flue dusts, and slags; and processing of lead, mercury, and battery wastes. Individual papers have been processed separately for inclusion in the appropriate data bases

  16. Induction melting for volume reduction of metallic TRU wastes

    International Nuclear Information System (INIS)

    Westsik, J.H. Jr.; Montgomery, D.R.; Katayama, Y.B.; Ross, W.A.

    1986-01-01

    Volume reduction of metallic transuranic wastes offers economic and safety incentives for treatment of wastes generated at a hypothetical commercial fuel reprocessing facility. Induction melting has been identified as the preferred process for volume reduction of spent fuel hulls, fuel assembly hardware, and failed equipment from a reprocessing plant. Bench-scale melting of Zircaloy and stainless steel mixtures has been successfully conducted in a graphite crucible inside a large vacuum chamber. A low-melting-temperature alloy forms that has demonstrated excellent leach resistance. The alloy can be used to encapsulate other metallic wastes that cannot be melted using the existing equipment design

  17. Electrochemical Corrosion Studies for Modeling Metallic Waste Form Release Rates

    International Nuclear Information System (INIS)

    Poineau, Frederic; Tamalis, Dimitri

    2016-01-01

    The isotope 99 Tc is an important fission product generated from nuclear power production. Because of its long half-life (t 1/2 = 2.13 ∙ 105 years) and beta-radiotoxicity (β - = 292 keV), it is a major concern in the long-term management of spent nuclear fuel. In the spent nuclear fuel, Tc is present as an alloy with Mo, Ru, Rh, and Pd called the epsilon-phase, the relative amount of which increases with fuel burn-up. In some separation schemes for spent nuclear fuel, Tc would be separated from the spent fuel and disposed of in a durable waste form. Technetium waste forms under consideration include metallic alloys, oxide ceramics and borosilicate glass. In the development of a metallic waste form, after separation from the spent fuel, Tc would be converted to the metal, incorporated into an alloy and the resulting waste form stored in a repository. Metallic alloys under consideration include Tc–Zr alloys, Tc–stainless steel alloys and Tc–Inconel alloys (Inconel is an alloy of Ni, Cr and iron which is resistant to corrosion). To predict the long-term behavior of the metallic Tc waste form, understanding the corrosion properties of Tc metal and Tc alloys in various chemical environments is needed, but efforts to model the behavior of Tc metallic alloys are limited. One parameter that should also be considered in predicting the long-term behavior of the Tc waste form is the ingrowth of stable Ru that occurs from the radioactive decay of 99 Tc ( 99 Tc → 99 Ru + β - ). After a geological period of time, significant amounts of Ru will be present in the Tc and may affect its corrosion properties. Studying the effect of Ru on the corrosion behavior of Tc is also of importance. In this context, we studied the electrochemical behavior of Tc metal, Tc-Ni alloys (to model Tc-Inconel alloy) and Tc-Ru alloys in acidic media. The study of Tc-U alloys has also been performed in order to better understand the nature of Tc in metallic spent fuel. Computational modeling

  18. Adsorption of tetracycline on Fe (hydr)oxides: effects of pH and metal cation (Cu2+, Zn2+ and Al3+) addition in various molar ratios

    Science.gov (United States)

    Hsu, Liang-Ching; Liu, Yu-Ting; Syu, Chien-Hui; Huang, Mei-Hsia; Teah, Heng Yi

    2018-01-01

    Iron (Fe) (hydr)oxides control the mobility and bioavailability of tetracycline (TC) in waters and soils. Adsorption of TC on Fe (hydr)oxides is greatly affected by polyvalent metals; however, impacts of molar metal/TC ratios on TC adsorptive behaviours on Fe (hydr)oxides remain unclear. Results showed that maximum TC adsorption on ferrihydrite and goethite occurred at pH 5–6. Such TC adsorption was generally promoted by the addition of Cu2+, Zn2+ and Al3+. The greatest increase in TC adsorption was found in the system with molar Cu/TC ratio of 3 due to the formation of Fe hydr(oxide)–Cu–TC ternary complexes. Functional groups on TC that were responsible for the complexation with Cu2+shifted from phenolic diketone groups at Cu/TC molar ratio adsorption at a molar Al/TC ratio of 1. However, TC adsorption decreased for Al/TC molar ratio > 1 as excess Al3+ led to the competitive adsorption with Al/TC complexes. For the Zn2+ addition, no significant correlation was found between TC adsorption capacity and molar Zn/TC ratios. PMID:29657795

  19. The role of electrolyte anions (ClO4-, NO3-, and Cl-) in divalent metal (M2+) adsorption on oxide and hydroxide surfaces in salt solutions

    International Nuclear Information System (INIS)

    Criscenti, L.J.; Sverjensky, D.A.

    1999-01-01

    Adsorption of divalent metal ions (M 2+ ) onto oxide and hydroxide surfaces from solutions of strong electrolytes has typically been inferred to take place without the involvement of the electrolyte anion. Only in situations where M 2+ forms a strong enough aqueous complex with the electrolyte anion (for example, CdCl + or PbCl + ) has it been frequently suggested that the metal and the electrolyte anion adsorb simultaneously. A review of experimental data for the adsorption of Cd 2+ , Pb 2+ , Co 2+ , UO 2 2+ , Zn 2+ , Cu 2+ , Ba 2+ , Sr 2+ , and Ca 2+ onto quartz, silica, goethite, hydrous ferric oxide, corundum, γ-alumina, anatase, birnessite, and magnetite, from NaNO 3 , KNO 3 , NaCl, and NaClO 4 solutions over a wide range of ionic strengths (0.0001 M-1.0 M), reveals that transition and heavy metal adsorption behavior with ionic strength is a function of the type of electrolyte. In NaNO 3 solutions, metal adsorption exhibits little or no dependence on the ionic strength of the solution. However, in NaCl solutions, transition and heavy metal adsorption decreases strongly with increasing ionic strength. In NaClO 4 solutions, metal adsorption decreases strongly with increasing ionic strength. In NaClO 4 solutions, metal adsorption exhibits little dependence on ionic strength but is often suggestive of an increase in metal adsorption with increasing ionic strength. Analysis of selected adsorption edges was carried out using the extended triple-layer model and aqueous speciation models that included metal-nitrate, metal-chloride, and metal-hydroxide complexes

  20. Process for treating waste water having low concentrations of metallic contaminants

    Science.gov (United States)

    Looney, Brian B; Millings, Margaret R; Nichols, Ralph L; Payne, William L

    2014-12-16

    A process for treating waste water having a low level of metallic contaminants by reducing the toxicity level of metallic contaminants to an acceptable level and subsequently discharging the treated waste water into the environment without removing the treated contaminants.

  1. Metal Recovery from Industrial Solid Waste — Contribution to Resource Sustainability

    Science.gov (United States)

    Yang, Yongxiang

    Increased demand of metals has driven the accelerated mining and metallurgical production in recent years, causing fast depletion of primary metals resources. On the contrary, the mining and metallurgical industry generates large amount of solid residues and waste such as tailings, slags, flue dust and leach residues, with relative low valuable metal contents. On the other hand, end-of-life (EoL) consumer products form another significant resources. The current technology and processes for primary metals production are not readily applicable for direct metals extraction from these waste materials, and special adaptation and tailor-made processes are required. In the present paper, various solid waste resources are reviewed, and current technologies and R&D trends are discussed. The recent research at author's group is illustrated for providing potential solutions to future resource problems, including metal recovery from MSW incinerator bottom ashes, zinc recovery from industrial ashes and residues, and rare earth metals recovery from EoL permanent magnets.

  2. Competitive metal sorption and desorption onto Kappaphycus alvarezii, seaweed waste biomass

    International Nuclear Information System (INIS)

    Lee, K.O.; Nazaruddin Ramli; Mamot Said; Musa Ahmad; Suhaimi Mohd Yasir; Arbakariya Ariff

    2011-01-01

    Competitive metal sorption and desorption onto Kappaphycus alvarezii waste biomass were investigated. Metal sorption capacities were 0.82 mg Cr (III)/ g, 0.73 mg Ni (II)/ g, 0.67 mg Cd (II)/ g, 0.65 mg Cu( II)/ g and 0.64 mg Zn (II)/ g in multi metal system. Whereas, desorption efficiencies were 66.08 %, 71.50 % and 80.44 % using 0.1 M HNO 3 , 0.1 M HCl and 0.1 M H 2 SO 4 , respectively. The metal sorption sequence were Cr(III) > Ni(II) > Cd(II) > Cu(II) > Zn(II), while metal desorption sequence were Cd(II) > Zn(II) > Cu(II) > Ni(II) > Cr(III). Fourier transformed infrared spectroscopy (FTIR) technique was used to characterize the seaweed waste biomass. FTIR analysis shown that carbonyl (-C-O) and nitrile (-C≡N) groups interact with the metal ions. The experiments result revealed that Kappaphycus alvarezii waste biomass represent an attractive candidate to remove multi metal ions. (author)

  3. Competitive metal sorption and desorption onto Kappaphycus alvarezii, seaweed waste biomass

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K O; Ramli, Nazaruddin; Said, Mamot; Ahmad, Musa [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), Bangi, selangor (Malaysia); Yasir, Suhaimi Mohd [School of Sciences and Technology, Universiti Malaysia Sabah (UMS), Sabah (Malaysia); Arbakariya Ariff, E-mail: naza@ukm.my [Faculty of Biotechnology and Biomolecular science, Universiti Putra Malaysia (UPM), Serdang, Selangor (Malaysia)

    2011-07-15

    Competitive metal sorption and desorption onto Kappaphycus alvarezii waste biomass were investigated. Metal sorption capacities were 0.82 mg Cr (III)/ g, 0.73 mg Ni (II)/ g, 0.67 mg Cd (II)/ g, 0.65 mg Cu( II)/ g and 0.64 mg Zn (II)/ g in multi metal system. Whereas, desorption efficiencies were 66.08 %, 71.50 % and 80.44 % using 0.1 M HNO{sub 3}, 0.1 M HCl and 0.1 M H{sub 2}SO{sub 4}, respectively. The metal sorption sequence were Cr(III) > Ni(II) > Cd(II) > Cu(II) > Zn(II), while metal desorption sequence were Cd(II) > Zn(II) > Cu(II) > Ni(II) > Cr(III). Fourier transformed infrared spectroscopy (FTIR) technique was used to characterize the seaweed waste biomass. FTIR analysis shown that carbonyl (-C-O) and nitrile (-C{identical_to}N) groups interact with the metal ions. The experiments result revealed that Kappaphycus alvarezii waste biomass represent an attractive candidate to remove multi metal ions. (author)

  4. Bio-processing of solid wastes and secondary resources for metal extraction - A review.

    Science.gov (United States)

    Lee, Jae-Chun; Pandey, Banshi Dhar

    2012-01-01

    Metal containing wastes/byproducts of various industries, used consumer goods, and municipal waste are potential pollutants, if not treated properly. They may also be important secondary resources if processed in eco-friendly manner for secured supply of contained metals/materials. Bio-extraction of metals from such resources with microbes such as bacteria, fungi and archaea is being increasingly explored to meet the twin objectives of resource recycling and pollution mitigation. This review focuses on the bio-processing of solid wastes/byproducts of metallurgical and manufacturing industries, chemical/petrochemical plants, electroplating and tanning units, besides sewage sludge and fly ash of municipal incinerators, electronic wastes (e-wastes/PCBs), used batteries, etc. An assessment has been made to quantify the wastes generated and its compositions, microbes used, metal leaching efficiency etc. Processing of certain effluents and wastewaters comprising of metals is also included in brief. Future directions of research are highlighted. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Carbonation of metal silicates for long-term CO2 sequestration

    Science.gov (United States)

    Blencoe, James G; Palmer, Donald A; Anovitz, Lawrence M; Beard, James S

    2014-03-18

    In a preferred embodiment, the invention relates to a process of sequestering carbon dioxide. The process comprises the steps of: (a) reacting a metal silicate with a caustic alkali-metal hydroxide to produce a hydroxide of the metal formerly contained in the silicate; (b) reacting carbon dioxide with at least one of a caustic alkali-metal hydroxide and an alkali-metal silicate to produce at least one of an alkali-metal carbonate and an alkali-metal bicarbonate; and (c) reacting the metal hydroxide product of step (a) with at least one of the alkali-metal carbonate and the alkali-metal bicarbonate produced in step (b) to produce a carbonate of the metal formerly contained in the metal silicate of step (a).

  6. Characterization of a Fe-based alloy system for an AFCI metallic waste form - 16134

    International Nuclear Information System (INIS)

    Williamson, Mark J.; Sindelar, Robert L.

    2009-01-01

    The AFCI waste management program aims to provide a minimum volume stable waste form for high level radioactive waste from the various process streams. The AFCI Integrated Waste Management Strategy document has identified a Fe-Zr metallic waste form (MWF) as the baseline alloy for disposal of Tc metal, undissolved solids, and TRUEX fission product wastes. Several candidate alloys have been fabricated using vacuum induction melting to investigate the limits of waste loading as a function of Fe and Zr content. Additional melts have been produced to investigate source material composition. These alloys have been characterized using SEM/EDS and XRD. Phase assemblage and specie partitioning of Re metal (surrogate for Tc) and noble metal FP elements into the phases is reported. (authors)

  7. The state of the art on the radioactive metal waste recycling technologies

    International Nuclear Information System (INIS)

    Oh, Won Jin; Moon, Jei Kwon; Jung, Chong Hun; Park, Sang Yoon

    1997-09-01

    As the best strategy to manage the radioactive metal wastes which are generated during operation and decommissioning of nuclear facilities, the following recycling technologies are investigated. 1. decontamination technologies for radioactive metal waste recycling 2. decontamination waste treatment technologies. 3. residual radioactivity evaluation technologies. (author). 260 refs., 26 tabs., 31 figs

  8. Volume Reduction of Decommissioning Radioactive Burnable and Metal Wastes

    Energy Technology Data Exchange (ETDEWEB)

    Min, B. Y.; Lee, Y. J.; Yun, G. S.; Lee, K. W.; Moon, J. K. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Choi, Y. K.; Cho, J. H. [SunKwang Atomic Energy Safety Co., Seoul (Korea, Republic of)

    2014-10-15

    A large quantity of radioactive waste was generated during the decommissioning projects. For the purpose of the volume reduction and clearance for decommissioning wastes from decommissioning projects, the incineration and high melting technology has been selected for the decommissioning wastes treatment. The volume reduction of the combustible wastes through the incineration technologies has merits from the view point of a decrease in the amount of waste to be disposed of resulting in a reduction of the disposal cost. Incineration is generally accepted as a method of reducing the volume of radioactive waste. The incineration technology is an effective treatment method that contains hazardous chemicals as well as radioactive contamination. Incinerator burns waste at high temperature. Incineration of a mixture of chemically hazardous and radioactive materials, known as 'mixed waste,' has two principal goals: to reduce the volume and total chemical toxicity of the waste. Incineration itself does not destroy the metals or reduce the radioactivity of the waste. A proven melting technology is currently used for low-level waste (LLW) at several facilities worldwide. These facilities use melting as a means of processing LLW for unrestricted release of the metal or for recycling within the nuclear sector. About 16.4 tons of decommissioning combustible waste has been treated using Oxygen Enriched incineration. The incineration facility operated quite smoothly through the analysis major critical parameters of off-gas.

  9. Volume Reduction of Decommissioning Radioactive Burnable and Metal Wastes

    International Nuclear Information System (INIS)

    Min, B. Y.; Lee, Y. J.; Yun, G. S.; Lee, K. W.; Moon, J. K.; Choi, Y. K.; Cho, J. H.

    2014-01-01

    A large quantity of radioactive waste was generated during the decommissioning projects. For the purpose of the volume reduction and clearance for decommissioning wastes from decommissioning projects, the incineration and high melting technology has been selected for the decommissioning wastes treatment. The volume reduction of the combustible wastes through the incineration technologies has merits from the view point of a decrease in the amount of waste to be disposed of resulting in a reduction of the disposal cost. Incineration is generally accepted as a method of reducing the volume of radioactive waste. The incineration technology is an effective treatment method that contains hazardous chemicals as well as radioactive contamination. Incinerator burns waste at high temperature. Incineration of a mixture of chemically hazardous and radioactive materials, known as 'mixed waste,' has two principal goals: to reduce the volume and total chemical toxicity of the waste. Incineration itself does not destroy the metals or reduce the radioactivity of the waste. A proven melting technology is currently used for low-level waste (LLW) at several facilities worldwide. These facilities use melting as a means of processing LLW for unrestricted release of the metal or for recycling within the nuclear sector. About 16.4 tons of decommissioning combustible waste has been treated using Oxygen Enriched incineration. The incineration facility operated quite smoothly through the analysis major critical parameters of off-gas

  10. Comparative assessment of metallurgical recovery of metals from electronic waste with special emphasis on bioleaching.

    Science.gov (United States)

    Priya, Anshu; Hait, Subrata

    2017-03-01

    Waste electrical and electronic equipment (WEEE) or electronic waste (e-waste) is one of the fastest growing waste streams in the urban environment worldwide. The core component of printed circuit board (PCB) in e-waste contains a complex array of metals in rich quantity, some of which are toxic to the environment and all of which are valuable resources. Therefore, the recycling of e-waste is an important aspect not only from the point of waste treatment but also from the recovery of metals for economic growth. Conventional approaches for recovery of metals from e-waste, viz. pyrometallurgical and hydrometallurgical techniques, are rapid and efficient, but cause secondary pollution and economically unviable. Limitations of the conventional techniques have led to a shift towards biometallurgical technique involving microbiological leaching of metals from e-waste in eco-friendly manner. However, optimization of certain biotic and abiotic factors such as microbial species, pH, temperature, nutrients, and aeration rate affect the bioleaching process and can lead to profitable recovery of metals from e-waste. The present review provides a comprehensive assessment on the metallurgical techniques for recovery of metals from e-waste with special emphasis on bioleaching process and the associated factors.

  11. Chemical Decontamination of Metallic Waste from Uranium Conversion Plant Dismantling

    International Nuclear Information System (INIS)

    Hwang, D. S.; Choi, Y. D.; Hwang, S. T.; Park, J. H.; Byun, J. I.; Jang, N. S.

    2005-01-01

    Korea Atomic Energy Research Institute (KAERI) started a decommissioning program of the uranium conversion plant. Pre-work was carried as follows; installation of the access control facility, installation of a changing room and shower room, designation of an emergency exit way and indicating signs, installation of a radiation management facility, preparation of a storage area for tools and equipments, inspection and load test of crane, distribution and packaging of existing waste, and pre-decontamination of the equipment surface and the interior. First, decommissioning work was performed in kiln room, which will be used for temporary radioactive waste storage room. Kiln room housed hydro fluorination rotary kiln for production of uranium tetra-fluoride. The kiln is about 0.8 m in diameter and 5.5 m long. The total dismantled waste was 6,690 kg, 73 % of which was metallic waste and 27 % the others such as cable, asbestos, concrete, secondary waste, etc. And effluent treatment room and filtration room were dismantled for installation of decontamination equipment and lagoon sludge treatment equipment. There were tanks and square mixer in these rooms. The total dismantled waste was 17,250 kg, 67% of which was metallic waste and 33% the others. These dismantled metallic wastes consist of stainless and carbon steel. In this paper, the stainless steel plate and pipe were decontaminated by the chemical decontamination with ultrasonic

  12. Induction melting for volume reduction of metallic TRU wastes

    International Nuclear Information System (INIS)

    Westsik, J.H. Jr.; Montgomery, D.R.; Katayama, Y.B.; Ross, W.A.

    1986-02-01

    Volume reduction of metallic transuranic wastes offers economic and safety incentives for treatment of wastes generated at a hypothetical commercial fuel reprocessing facility. Induction melting has been identified as the preferred process for volume reduction of spent fuel hulls, fuel assembly hardware, and failed equipment from a reprocessing plant. Bench-scale melting of Zircaloy and stainless steel mixtures has been successfully conducted in a graphite crucible inside a large vacuum chamber. A low-melting-temperature alloy forms that has demonstrated excellent leach resistance. The alloy can be used to encapsulate other metallic wastes that cannot be melted using the existing equipment design. 18 refs., 4 figs., 3 tabs

  13. MINE WASTE TECHNOLOGY PROGRAM; PHOSPHATE STABILIZATION OF HEAVY METALS CONTAMINATED MINE WASTE YARD SOILS, JOPLIN, MISSOURI NPL SITE

    Science.gov (United States)

    This document summarizes the results of Mine Waste Technology Project 22-Phosphate Stabilization of Heavy Metals-Contaminated Mine Waste Yard Soils. Mining, milling, and smelting of ores near Joplin, Missouri, have resulted in heavy metal contamination of the area. The Joplin s...

  14. Application of hydrothermally crystallized coal ashes for waste water treatment, 2

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Yasuhiko; Kakimoto, Kohji; Ogawa, Hiroaki; Tomari, Masao; Sakamoto, Eiji; Asahara, Teruzo

    1986-11-01

    To provide an application of combustion coal ash, hydrothermal reaction of fly ash (FA) and clinker ash (CA) is performed and an investigation is carried out to determine the capability of the P type zeolite produced from these ashes to adsorb heavy metal ions. Hydrothermal reaction of FA and CA at 95 - 100 deg C is conducted with various concentrations of sodium hydroxide for various reaction times. Both types of ash are found to easily undergo crystallization to form P type zeolite (PZ) and hydroxy sodalite (HS) when treated with a sodium hydroxide solution (sodium hydroxide/coal ash = 10 v/w) for 18 hours. The FA-PZ and CA-PZ produced by the hydrothermal treatment have degrees of crystallinity in the range of 40 - 60 percent. It is seen that the degree of crystallinity gradually increases with increasing treatment time. The crystallinity of hydrothermally treated coal ash is also shown to have good correlation with the base substitution capacity and the maximum adsorption of ammonium ion. Furthermore, they are shown to effectively adsorb metal ions, in particular those of lead, cadmium and strontium. It is suggested that they may serve as an enrichment agent for low-level radioactive nuclides produced in nuclear power plants. They also seem to have the possibility of serving as a metal elution preventive for industrial wastes of some special types. (Nogami, K.).

  15. Some thermal analysis aspects of metal encapsulated waste

    International Nuclear Information System (INIS)

    Jardine, L.J.; Steindler, M.J.

    1978-01-01

    This paper is to summarize two waste management schemes: (1) packaging for extended storage of LWR spent fuel assemblies, with the capability for simple conversion either to terminal storage if a ''throwaway'' fuel cycle is ultimately adopted or to a form that can be reprocessed and (2) packaging for the terminal storage of solidified high-level wastes when the reprocessing of spent fuel is initiated. Only concepts utilizing metals or metal alloys to encapsulate either spent fuel or solidified high-level waste forms have been considered. Conceptual process flow sheets have been constructed to allow potential advantages and disadvantages of encapsulation alternatives to be identified in comparison with more conventional reference processes. Identification is also made of uncertainties of the analysis due to a lack of fundamental data required to perform evaluations. 3 tables

  16. Thermal treatment of toxic metals of industrial hazardous wastes with fly ash and clay

    Energy Technology Data Exchange (ETDEWEB)

    Singh, I.B. [Regional Research Laboratory, Council of Scientific and Industrial Research, Hoshangabad Road, Bhopal 462026 (India)]. E-mail: ibsingh58@yahoo.com; Chaturvedi, K. [Regional Research Laboratory, Council of Scientific and Industrial Research, Hoshangabad Road, Bhopal 462026 (India); Morchhale, R.K. [Regional Research Laboratory, Council of Scientific and Industrial Research, Hoshangabad Road, Bhopal 462026 (India); Yegneswaran, A.H. [Regional Research Laboratory, Council of Scientific and Industrial Research, Hoshangabad Road, Bhopal 462026 (India)

    2007-03-06

    Waste generated from galvanizing and metal finishing processes is considered to be a hazardous due to the presence of toxic metals like Pb, Cu, Cr, Zn, etc. Thermal treatment of such types of wastes in the presence of clay and fly ash can immobilizes their toxic metals to a maximum level. After treatment solidified mass can be utilized in construction or disposed off through land fillings without susceptibility of re-mobilization of toxic metals. In the present investigation locally available clay and fly ash of particular thermal power plant were used as additives for thermal treatment of both of the wastes in their different proportions at 850, 900 and 950 deg. C. Observed results indicated that heating temperature to be a key factor in the immobilization of toxic metals of the waste. It was noticed that the leachability of metals of the waste reduces to a negligible level after heating at 950 deg. C. Thermally treated solidified specimen of 10% waste and remaining clay have shown comparatively a higher compressive strength than clay fired bricks used in building construction. Though, thermally heated specimens made of galvanizing waste have shown much better strength than specimen made of metal finishing waste. The lechability of toxic metals like Cr, Cu, Pb and Zn became far below from their regulatory threshold after heating at 950 deg. C. Addition of fly ash did not show any improvement either in engineering property or in leachability of metals from the solidified mass. X-ray diffraction (XRD) analysis of the solidified product confirmed the presence of mixed phases of oxides of metals.

  17. Bio-processing of solid wastes and secondary resources for metal extraction – A review

    International Nuclear Information System (INIS)

    Lee, Jae-chun; Pandey, Banshi Dhar

    2012-01-01

    Highlights: ► Review focuses on bio-extraction of metals from solid wastes of industries and consumer goods. ► Bio-processing of certain effluents/wastewaters with metals is also included in brief. ► Quantity/composition of wastes are assessed, and microbes used and leaching conditions included. ► Bio-recovery using bacteria, fungi and archaea is highlighted for resource recycling. ► Process methodology/mechanism, R and D direction and scope of large scale use are briefly included. - Abstract: Metal containing wastes/byproducts of various industries, used consumer goods, and municipal waste are potential pollutants, if not treated properly. They may also be important secondary resources if processed in eco-friendly manner for secured supply of contained metals/materials. Bio-extraction of metals from such resources with microbes such as bacteria, fungi and archaea is being increasingly explored to meet the twin objectives of resource recycling and pollution mitigation. This review focuses on the bio-processing of solid wastes/byproducts of metallurgical and manufacturing industries, chemical/petrochemical plants, electroplating and tanning units, besides sewage sludge and fly ash of municipal incinerators, electronic wastes (e-wastes/PCBs), used batteries, etc. An assessment has been made to quantify the wastes generated and its compositions, microbes used, metal leaching efficiency etc. Processing of certain effluents and wastewaters comprising of metals is also included in brief. Future directions of research are highlighted.

  18. Treatment of radioactive metallic waste by the electro-slag melting method

    International Nuclear Information System (INIS)

    Ochiai, Atsuhiro; Nagura, Kanetake; Noura, Tsuyoshi

    1983-01-01

    The applicability of the electro-slag melting method for treating plutonuim contaminated metallic waste was studied. A 100kg test furnace was built and simulated metallic waste was melted and solidified in this furnace. Waste volume was reduced to 1/25 with a decontamination factor of 25 and the slag and the copper mold are repeatedly usable. The process is expected to be employed in the project of PWTF (Plutonium contaminated Wate Treatment Facilities). (author)

  19. Metal waste forms from treatment of EBR-II spent fuel

    International Nuclear Information System (INIS)

    Abraham, D. P.

    1998-01-01

    Demonstration of Argonne National Laboratory's electrometallurgical treatment of spent nuclear fuel is currently being conducted on irradiated, metallic driver fuel and blanket fuel elements from the Experimental Breeder Reactor-II (EBR-II) in Idaho. The residual metallic material from the electrometallurgical treatment process is consolidated into an ingot, the metal waste form (MWF), by employing an induction furnace in a hot cell. Scanning electron microscopy (SEM) and chemical analyses have been performed on irradiated cladding hulls from the driver fuel, and on samples from the alloy ingots. This paper presents the microstructures of the radioactive ingots and compares them with observations on simulated waste forms prepared using non-irradiated material. These simulated waste forms have the baseline composition of stainless steel - 15 wt % zirconium (SS-15Zr). Additions of noble metal elements, which serve as surrogates for fission products, and actinides are made to that baseline composition. The partitioning of noble metal and actinide elements into alloy phases and the role of zirconium for incorporating these elements is discussed in this paper

  20. Decontamination method for radiation-contaminated metal waste

    International Nuclear Information System (INIS)

    Suwa, Takeshi; Kuribayashi, Nobuhide; Yasumune, Taketoshi.

    1991-01-01

    In immersing radiation-contaminated metal wastes into a sulfuric acid solution thereby peeling and removing radioactive deposition cruds and dissolving the surface of the matrix metals to eliminate radioactive contaminants, when the potential of the sulfuric acid solution is shifted to a higher direction by more than a certain level due to the increase of the amount of metal ions leached from the cruds and the matrix material, the leached metal ions are electrolytically reduced to control the potential of the sulfuric acid solution to less than a predetermined potential level. Although the dissolving rate is increased as the concentration of the sulfuric acid solution is higher, it is preferably from 0.5 to 2 mol/l, since higher concentration increases the load on the waste liquid processing. Further, the temperature for solution is set to higher than a room temperature and, preferably from 50 to 90degC. Further, the potential level of the solution, although varies somewhat depending on the concentration of the leached metal ions and the temperature, is preferably controlled to less than 0.1 to 0.2 V. This can attain high decontaminating effect in a short period of time by using a sulfuric acid solution alone. (T.M.)

  1. Electrochemical Corrosion Studies for Modeling Metallic Waste Form Release Rates

    Energy Technology Data Exchange (ETDEWEB)

    Poineau, Frederic [Univ. of Nevada, Las Vegas, NV (United States); Tamalis, Dimitri [Florida Memorial Univ., Miami Gardens, FL (United States)

    2016-08-01

    The isotope 99Tc is an important fission product generated from nuclear power production. Because of its long half-life (t1/2 = 2.13 ∙ 105 years) and beta-radiotoxicity (β⁻ = 292 keV), it is a major concern in the long-term management of spent nuclear fuel. In the spent nuclear fuel, Tc is present as an alloy with Mo, Ru, Rh, and Pd called the epsilon-phase, the relative amount of which increases with fuel burn-up. In some separation schemes for spent nuclear fuel, Tc would be separated from the spent fuel and disposed of in a durable waste form. Technetium waste forms under consideration include metallic alloys, oxide ceramics and borosilicate glass. In the development of a metallic waste form, after separation from the spent fuel, Tc would be converted to the metal, incorporated into an alloy and the resulting waste form stored in a repository. Metallic alloys under consideration include Tc–Zr alloys, Tc–stainless steel alloys and Tc–Inconel alloys (Inconel is an alloy of Ni, Cr and iron which is resistant to corrosion). To predict the long-term behavior of the metallic Tc waste form, understanding the corrosion properties of Tc metal and Tc alloys in various chemical environments is needed, but efforts to model the behavior of Tc metallic alloys are limited. One parameter that should also be considered in predicting the long-term behavior of the Tc waste form is the ingrowth of stable Ru that occurs from the radioactive decay of 99Tc (99Tc → 99Ru + β⁻). After a geological period of time, significant amounts of Ru will be present in the Tc and may affect its corrosion properties. Studying the effect of Ru on the corrosion behavior of Tc is also of importance. In this context, we studied the electrochemical behavior of Tc metal, Tc-Ni alloys (to model Tc-Inconel alloy) and Tc-Ru alloys in acidic media. The study of Tc-U alloys has also been performed in order to better understand the

  2. Carbonation of metal silicates for long-term CO.sub.2 sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Blencoe, James G.; Palmer, Donald A.; Anovitz, Lawrence M.; Beard, James S.

    2017-08-01

    In a preferred embodiment, the invention relates to a process of sequestering carbon dioxide. The process comprises the steps of: (a) reacting a metal silicate with a caustic alkali-metal hydroxide to produce a hydroxide of the metal formerly contained in the silicate; (b) reacting carbon dioxide with at least one of a caustic alkali-metal hydroxide and an alkali-metal silicate to produce at least one of an alkali-metal carbonate and an alkali-metal bicarbonate; and (c) reacting the metal hydroxide product of step (a) with at least one of the alkali-metal carbonate and the alkali-metal bicarbonate produced in step (b) to produce a carbonate of the metal formerly contained in the metal silicate of step (a).

  3. Carbonation of metal silicates for long-term CO.sub.2 sequestration

    Science.gov (United States)

    Blencoe, James G [Harriman, TN; Palmer, Donald A [Oliver Springs, TN; Anovitz, Lawrence M [Knoxville, TN; Beard, James S [Martinsville, VA

    2012-02-14

    In a preferred embodiment, the invention relates to a process of sequestering carbon dioxide. The process comprises the steps of: (a) reacting a metal silicate with a caustic alkali-metal hydroxide to produce a hydroxide of the metal formerly contained in the silicate; (b) reacting carbon dioxide with at least one of a caustic alkali-metal hydroxide and an alkali-metal silicate to produce at least one of an alkali-metal carbonate and an alkali-metal bicarbonate; and (c) reacting the metal hydroxide product of step (a) with at least one of the alkali-metal carbonate and the alkali-metal bicarbonate produced in step (b) to produce a carbonate of the metal formerly contained in the metal silicate of step (a).

  4. Mass-spectrometric study of ion clustering in alkali-metal hydroxide vapor: cluster-ion energy and structural characteristics

    International Nuclear Information System (INIS)

    Kudin, L.S.; Butman, M.F.; Krasnov, K.S.

    1986-01-01

    Various positive and negative ions have been recorded in the equilibrium vapors from alkali-metal hydroxides: M/sup +/-/, OH - , O - , MO - , MOH - , and X/sup +/-/ (MOH)/sub n/, where X = M/sup +/-/, OH - , n = 1-6. The equilibrium constants have been measured for X/sup +/-/(MOH)/sub n/ = x/sup +/-/ + nMOH(k), n = 1-3, and the enthalpies of reaction have been determined, from which the enthalpies of formation and dissociation energies of X/sup +/-/ (MOH)/sub n/ have been calculated. The relative stabilities of the ions in the series from Na to Cs are examined

  5. Nickel hydroxide electrode. 3: Thermogravimetric investigations of nickel (II) hydroxides

    Science.gov (United States)

    Dennstedt, W.; Loeser, W.

    1982-01-01

    Water contained in Ni hydroxide influences its electrochemical reactivity. The water content of alpha and beta Ni hydroxides is different with respect to the amount and bond strength. Thermogravimetric experiments show that the water of the beta Ni hydroxides exceeding the stoichiometric composition is completely removed at 160 deg. The water contained in the interlayers of the beta hydroxide, however, is removed only at higher temperatures, together with the water originating from the decomposition of the hydroxide. These differences are attributed to the formation of II bonds within the interlayers and between interlayers and adjacent main layers. An attempt is made to explain the relations between water content and the oxidizability of the Ni hydroxides.

  6. Sol-Gel Stabilization of Heavy Metal Waste

    National Research Council Canada - National Science Library

    Cropek, Donald

    2000-01-01

    .... The types of media are varied and include soils, ashes, and sludges. Waste having a leachable metal concentration above the Toxicity Characteristic Leaching Procedure limit established by the U.S...

  7. Development on inspection and recognition procedure of clearance level of radioactivity in metal wastes, to secure social safety for reused metals

    International Nuclear Information System (INIS)

    Hattori, Takatoshi

    2002-01-01

    The Central Research Institute of Electric Power Industry developed a new procedure automatically measurable on radioactivity level in metal wastes in high precision by using the newest three-dimensional (3D) shape measuring technology and 3D Monte-Carlo computing technology (a code to probabilistically compute formation and movement of gamma-ray from metal wastes to detectors) to contribute to inspection and recognition of clearance level of radioactivity. This procedure can prove no super micro amount of radioactivity of 250 Bq in metal wastes of testing objects. As this proof is an evaluation of conservative safety side showing no pollution at any 100 sq cm of surface of the metal wastes on considering for taking-out reference on matters, for its price, the procedure cancelled all of labors to test all of metal wastes surfaces by survey meter, and so on, and feasibility of overlook of pollution at places difficult to measure by using survey meters can perfectly excluded. Its practical tester is planned to produce at 2002 fiscal year, and testing performance against actual metal wastes is planned to confirm by its proof-test on 2003 to 2004 fiscal years. (G.K.)

  8. Application of a modified electrochemical system for surface decontamination of radioactive metal waste

    International Nuclear Information System (INIS)

    Lee, J.H.; Lim, Y.K.; Yang, H.Y.; Shin, S.W.; Song, M.J.

    2003-01-01

    Conventional and modified electrolytic decontamination experiments were performed in a solution of sodium sulfate for the decontamination of carbon steel as the simulated metal wastes which are generated in large amounts from nuclear power plants. The effect of reaction time, current density and concentration of electrolytes in the modified electrolytic decontamination system were examined to remove the surface contamination of the simulated radioactive metal wastes. As for the results of this research, the modified electrochemical decontamination process can decontaminate more effectively than the conventional decontamination process by applying different anode material which causes higher induced electro-motive forces. When 0.5 M sodium sulfate, 0.4 A/cm 2 current density and 30 minutes reaction time were applied in the modified process, a 16 μm thickness change that is expected to remove most surface contamination in radioactive metal wastes was achieved on carbon steel which is the main material of radioactive metal waste in nuclear power plants. The decontamination efficiency of metal waste showed similar results with the small and large lab-scale modified electrochemical system. The application of this modified electrolytic decontamination system is expected to play a considerable role for decontamination of radioactive metal waste in nuclear power plants in the near future. (author)

  9. Biosorption of heavy metals under anaerobic conditions. Final report; Biosorption von Schwermetallen unter anaeroben Bedingungen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Kreikenbohm, R.

    1996-12-31

    The precipitation of heavy metals as hydroxides is the standard technique for the decontamination of waste water streams polluted by these elements. On the other side, progress in research has been made concerning the biosorption onto dead biomass and bioprecipitation supported by physiologically active bacteria. As the aim of this study, a flexible strategy has been envisaged cleaning a waste water with definite heavy metal load underlying the process mentioned above. Suitable bacteria were enriched and the process was tested in a technical plant. As result, a very high efficiency of heavy metal elimination has been found. The field of application covered by the acquired process is identical with the whole range of the waste water streams polluted by heavy metals. In addition, a second stage may be necessary if there are any further contaminants to be removed. (orig.) [Deutsch] Bei der Reinigung von schwermetallhaltigen Abwaessern ist der derzeitige Stand der Technik gegeben durch die Neutralisationsfaellung als Hydroxide, waehrend in der Forschung damit begonnen wurde, Biosorption an devitaler Biomasse oder Biopraezipitation durch physiologisch aktive Bakterien zu untersuchen. Ziel des Vorhabens war die Ermittlung einer flexiblen Strategie fuer die Prozessfuehrung zur Abwasserreinigung bei vorgegebener Schadstoffbelastung auf der Basis des zuletzt genannten Prozesses. Dazu wurden geeignete Bakterien angereichert und das Verfahren in einer Technikumsanlage erprobt. Als Ergebnis wurde bei Zufuhr verschiedener Industrieabwaesser eine sehr hohe Effizienz in der Schwermetallelimination gefunden. Das Anwendungsgebiet des erarbeiteten Verfahrens erstreckt sich auf eine Vielzahl schwermetallbelasteter Abwaesser, wobei - je nach Art der weiteren Inhaltsstoffe - eine zusaetzliche Reinigungsstufe vor- oder nachgeschaltet werden muss. (orig.)

  10. Metallic elements fractionation in municipal solid waste incineration residues

    Science.gov (United States)

    Kowalski, Piotr R.; Kasina, Monika; Michalik, Marek

    2016-04-01

    Municipal solid waste incineration (MSWI) residues are represented by three main materials: bottom ash, fly ash and air pollution control (APC) residues. Among them ˜80 wt% is bottom ash. All of that materials are products of high temperature (>1000° C) treatment of waste. Incineration process allows to obtain significant reduction of waste mass (up to 70%) and volume (up to 90%) what is commonly used in waste management to reduce the amount need to be landfilled or managed in other way. Incineration promote accumulation non-combustible fraction of waste, which part are metallic elements. That type of concentration is object of concerns about the incineration residues impact on the environment and also gives the possibility of attempts to recover them. Metallic elements are not equally distributed among the materials. Several factors influence the process: melting points, volatility and place and forms of metallic occurrence in the incinerated waste. To investigate metallic elements distribution in MSWI residues samples from one of the biggest MSW incineration plant in Poland were collected in 2015. Chemical analysis with emphasis on the metallic elements content were performed using inductively coupled plasma optical emission (ICP-OES) and mass spectrometry (ICP-MS). The bottom ash was a SiO2-CaO-Al2O3-Fe2O3-Na2O rich material, whereas fly ash and APC residues were mostly composed of CaO and SiO2. All of the materials were rich in amorphous phase occurring together with various, mostly silicate crystalline phases. In a mass of bottom ash 11 wt% were metallic elements but also in ashes 8.5 wt% (fly ash) and ˜4.5 wt% (APC residues) of them were present. Among the metallic elements equal distribution between bottom and fly ash was observed for Al (˜3.85 wt%), Mn (770 ppm) and Ni (˜65 ppm). In bottom ash Fe (5.5 wt%), Cr (590 ppm) and Cu (1250 ppm) were concentrated. These values in comparison to fly ash were 5-fold higher for Fe, 3-fold for Cu and 1.5-fold for

  11. Process and equipment qualification of the ceramic and metal waste forms for spent fuel treatment

    International Nuclear Information System (INIS)

    Marsden, Ken; Knight, Collin; Bateman, Kenneth; Westphal, Brian; Lind, Paul

    2005-01-01

    The electrometallurgical process for treating sodium-bonded spent metallic fuel at the Materials and Fuels Complex of the Idaho National Laboratory separates actinides and partitions fission products into two waste forms. The first is the metal waste form, which is primarily composed of stainless steel from the fuel cladding. This stainless steel is alloyed with 15w% zirconium to produce a very corrosion-resistant metal which binds noble metal fission products and residual actinides. The second is the ceramic waste form which stabilizes fission product-loaded chloride salts in a sodalite and glass composite. These two waste forms will be packaged together for disposal at the Yucca Mountain repository. Two production-scale metal waste furnaces have been constructed. The first is in a large argon-atmosphere glovebox and has been used for equipment qualification, process development, and process qualification - the demonstration of process reliability for production of the DOE-qualified metal waste form. The second furnace will be transferred into a hot cell for production of metal waste. Prototype production-scale ceramic waste equipment has been constructed or procured; some equipment has been qualified with fission product-loaded salt in the hot cell. Qualification of the remaining equipment with surrogate materials is underway. (author)

  12. Metal leaching from refinery waste hydroprocessing catalyst.

    Science.gov (United States)

    Marafi, Meena; Rana, Mohan S

    2018-05-18

    The present study aims to develop an eco-friendly methodology for the recovery of nickel (Ni), molybdenum (Mo), and vanadium (V) from the refinery waste spent hydroprocessing catalyst. The proposed process has two stages: the first stage is to separate alumina, while the second stage involves the separation of metal compounds. The effectiveness of leaching agents, such as NH 4 OH, (NH 4 ) 2 CO 3 , and (NH 4 ) 2 S 2 O 8 , for the extraction of Mo, V, Ni, and Al from the refinery spent catalyst has been reported as a function of reagent concentration (0.5 to 2.0 molar), leaching time (1 to 6 h), and temperature (35 to 60°C). The optimal leaching conditions were achieved to obtain the maximum recovery of Mo, Ni, and V metals. The effect of the mixture of multi-ammonium salts on the metal extraction was also studied, which showed an adverse effect for Ni and V, while marginal improvement was observed for Mo leaching. The ammonium salts can form soluble metal complexes, in which stability or solubility depends on the nature of ammonium salt and the reaction conditions. The extracted metals and support can be reused to synthesize a fresh hydroprocessing catalyst. The process will reduce the refinery waste and recover the expensive metals. Therefore, the process is not only important from an environmental point of view but also vital from an economic perspective.

  13. Effects of Sodium Hydroxide and Sodium Aluminate on the Precipitation of Aluminum Containing Species in Tank Wastes

    International Nuclear Information System (INIS)

    Mattigod, Shas V.; Hobbs, David T.; Parker, Kent E.; McCready, David E.; Wang, Li Q.

    2006-01-01

    Aluminisilicate deposit buildup experienced during the tank waste volume-reduction process at the Savannah River Site (SRS) required an evaporator to be shut down. Studies were conducted at 80 C to identify the insoluble aluminosilicate phase(s) and to determine the kinetics of their formation and transformation. These tests were carried out under conditions more similar to those that occur in HLW tanks and evaporators. Comparison of our results with those reported from the site show very similar trends. Initially, an amorphous phase precipitates followed by a zeolite phase that transforms to sodalite and which finally converts to cancrinite. Our results also show the expected trend of an increased rate of transformation into denser aluminosilicate phases (sodalite and cancrinite) with time and increasing hydroxide concentrations

  14. Method of decontaminating radioactive metal wastes

    International Nuclear Information System (INIS)

    Miyaji, Nobuyoshi.

    1985-01-01

    Purpose: To completely prevent the surface contamination of an equipment and decrease the amount of radioactive wastes to be resulted. Method: The surfaces of vessels, pipeways or the likes of nuclear reactor facilities to be contaminated with radioactive materials are appended with thin plates of metals identical or different from the constituents of the surfaces so as to be releasable after use. The material and the thickness of the plates and the method of appending then are determined depending on the state of use of the appended portions. Since only the stripped plates have to be processed as radioactive wastes, the amount of wastes can be decreased and, since the scrap materials can be reused, it is advantageous in view of the resource-saving. (Sekiya, K.)

  15. Interaction of pristine hydrotalcite-like layered double hydroxides ...

    Indian Academy of Sciences (India)

    Metal oxides in general have surface acidic sites, but for exceptional circumstances, are not expected to mineralize CO2. Given their intrinsic basicity and an expandable interlayer gallery, the hydrotalcite-like layered double hydroxides (LDHs) are expected to be superior candidate materials for CO2 mineralization.

  16. Reducing the leachability of nitrate, phosphorus and heavy metals from soil using waste material

    Directory of Open Access Journals (Sweden)

    Faridullah

    Full Text Available Abstract Contaminants like nitrate (NO3, phosphorus (P and heavy metals in water are often associated with agricultural activities. Various soil and water remediation techniques have been employed to reduce the risk associated with these contaminants. A study was conducted to examine the extent of leaching of heavy metals (Cd, Ni, Pb and Cr, NO3 and P. For this purpose sandy and silt loam soils were amended with different waste materials, namely wood ash, solid waste ash, vegetable waste, charcoal, and sawdust. The soils were saturated with wastewater. Irrespective of the waste applied, the pH and EC of the amended soils were found to be greater than the control. Charcoal, sawdust and wood ash significantly decreased heavy metals, nitrate and phosphorus concentrations in the leachate. Treatments were more efficient for reducing Ni than other heavy metals concentrations. Waste amendments differed for heavy metals during the process of leaching. Heavy metals in the soil were progressively depleted due to the successive leaching stages. This research suggests that waste material may act as an adsorbent for the above contaminants and can reduce their leachability in soils.

  17. CJSC ECOMET-S facility for reprocessing and utilisation of radioactive metal waste: operating experience

    International Nuclear Information System (INIS)

    Gelbutovsky, A.B.; Kishkin, S.A.; Mochenov, M.I.; Troshev, A.V.; Cheremisin, P.I.; Chernichenko, A.A.

    2006-01-01

    The principal objective of the paper is to present operating experience in management of radioactive metal waste, originating at nuclear power facilities of the Russian Federation. Issues of radioactive metal waste recycling by melting, with the purpose of unrestricted re-use in industry, or restricted re-use within the nuclear industry, have been considered. The necessity for using a method of melting at the final stage of radioactive metal waste recycling has been proved. Priority measures to be taken and results achieved in the implementation of the Governmental purpose-oriented programme 'Radioactive Metal Waste Reprocessing and Utilization' have been considered, the CJSC ECOMET-S being the main contractor on the Programme. Main specifications and results of operating a commercial melting facility, owned by CJSC 'ECOMET-S' and used to recycle low-level radioactive metal waste originated at the Leningrad Nuclear Power Plant, have been presented. (author)

  18. Electronic spectra of anions intercalated in layered double hydroxides

    Indian Academy of Sciences (India)

    groups of the layers and interlayer water through the termi- nal atom symmetry ... results in a reaction with the metal hydroxide layers lead- ing to the ..... List of band positions observed for potassium salts of anion and LDH samples. Salts.

  19. Test plan for immobilization of salt-containing surrogate mixed wastes using polyester resins

    International Nuclear Information System (INIS)

    Biyani, R.K.; Douglas, J.C.; Hendrickson, D.W.

    1997-01-01

    Past operations at many Department of Energy (DOE) sites have resulted in the generation of several waste streams with high salt content. These wastes contain listed and characteristic hazardous constituents and are radioactive. The salts contained in the wastes are primarily chloride, sulfate, nitrate, metal oxides, and hydroxides. DOE has placed these types of wastes under the purview of the Mixed Waste Focus Area (MWFA). The MWFA has been tasked with developing and facilitating the implementation of technologies to treat these wastes in support of customer needs and requirements. The MWFA has developed a Technology Development Requirements Document (TDRD), which specifies performance requirements for technology owners and developers to use as a framework in developing effective waste treatment solutions. This project will demonstrate the use of polyester resins in encapsulating and solidifying DOE's mixed wastes containing salts, as an alternative to conventional and other emerging immobilization technologies

  20. Test plan for immobilization of salt-containing surrogate mixed wastes using polyester resins

    Energy Technology Data Exchange (ETDEWEB)

    Biyani, R.K.; Douglas, J.C.; Hendrickson, D.W.

    1997-07-07

    Past operations at many Department of Energy (DOE) sites have resulted in the generation of several waste streams with high salt content. These wastes contain listed and characteristic hazardous constituents and are radioactive. The salts contained in the wastes are primarily chloride, sulfate, nitrate, metal oxides, and hydroxides. DOE has placed these types of wastes under the purview of the Mixed Waste Focus Area (MWFA). The MWFA has been tasked with developing and facilitating the implementation of technologies to treat these wastes in support of customer needs and requirements. The MWFA has developed a Technology Development Requirements Document (TDRD), which specifies performance requirements for technology owners and developers to use as a framework in developing effective waste treatment solutions. This project will demonstrate the use of polyester resins in encapsulating and solidifying DOE`s mixed wastes containing salts, as an alternative to conventional and other emerging immobilization technologies.

  1. Metal Poisons for Criticality in Waste Streams

    International Nuclear Information System (INIS)

    Williamson, T.G.; Goslen, A.Q.

    1996-01-01

    Many of the wastes from processing fissile materials contain metals which may serve as nuclear criticality poisons. It would be advantageous to the criticality evaluation of these wastes to demonstrate that the poisons remain with the fissile materials and to demonstrate an always safe poison-to-fissile ratio. The first task, demonstrating that the materials stay together, is the job of the chemist, the second, calculating an always safe ratio, is an object of this paper

  2. The study of heavy metals leaching from waste foundry sands using a one-step extraction

    Science.gov (United States)

    Bożym, Marta

    2017-10-01

    There are a number of leaching test which are used to evaluate the effect of foundry waste disposal on the environment (TCLP, SPLP, ASTM at al.). Because the spent foundry sand are usually deposited at the ground level and they have a similar structure to the soil, survey mobility of metals using the same methods seems appropriate. One-step extraction allows for the evaluation of the mobility and bioavailability of metals in soil and waste. Waste foundry sands have been successfully used as a component in manufactured soils in U.S., but concern over metal contamination must be eliminated before considering this direction of use. The study evaluated the leaching of heavy metals (Cd, Pb, Cu, Zn, Cr, Ni) from deposited waste foundry sands. The overall, as well as heavy metals were extracted by different type of extractants: H2O, CH3COOH, HCl, EDTA, MgCl2 and NaCOOH. These extractants are most commonly used to study the mobility and bioavailability of metals in soil and waste. In the present study applicable standards and methodology described in the literature in analysis were used. The results allowed to evaluate the bioavailability of metals leached from those wastes.

  3. Treatment of EBR-I NaK mixed waste at Argonne National Laboratory and subsequent land disposal at the Idaho National Engineering and Environmental Laboratory

    International Nuclear Information System (INIS)

    Herrmann, S. D.; Buzzell, J. A.; Holzemer, M. J.

    1998-01-01

    Sodium/potassium (NaK) liquid metal coolant, contaminated with fission products from the core meltdown of Experimental Breeder Reactor I (EBR-I) and classified as a mixed waste, has been deactivated and converted to a contact-handled, low-level waste at Argonne's Sodium Component Maintenance Shop and land disposed at the Radioactive Waste Management Complex. Treatment of the EBR-I NaK involved converting the sodium and potassium to its respective hydroxide via reaction with air and water, followed by conversion to its respective carbonate via reaction with carbon dioxide. The resultant aqueous carbonate solution was solidified in 55-gallon drums. Challenges in the NaK treatment involved processing a mixed waste which was incompletely characterized and difficult to handle. The NaK was highly radioactive, i.e. up to 4.5 R/hr on contact with the mixed waste drums. In addition, the potential existed for plutonium and toxic characteristic metals to be present in the NaK, resultant from the location of the partial core meltdown of EBR-I in 1955. Moreover, the NaK was susceptible to degradation after more than 40 years of storage in unmonitored conditions. Such degradation raised the possibility of energetic exothermic reactions between the liquid NaK and its crust, which could have consisted of potassium superoxide as well as hydrated sodium/potassium hydroxides

  4. Treatment of EBR-I NaK mixed waste at Argonne National Laboratory and subsequent land disposal at the Idaho National Engineering and Environmental Laboratory.

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, S. D.; Buzzell, J. A.; Holzemer, M. J.

    1998-02-03

    Sodium/potassium (NaK) liquid metal coolant, contaminated with fission products from the core meltdown of Experimental Breeder Reactor I (EBR-I) and classified as a mixed waste, has been deactivated and converted to a contact-handled, low-level waste at Argonne's Sodium Component Maintenance Shop and land disposed at the Radioactive Waste Management Complex. Treatment of the EBR-I NaK involved converting the sodium and potassium to its respective hydroxide via reaction with air and water, followed by conversion to its respective carbonate via reaction with carbon dioxide. The resultant aqueous carbonate solution was solidified in 55-gallon drums. Challenges in the NaK treatment involved processing a mixed waste which was incompletely characterized and difficult to handle. The NaK was highly radioactive, i.e. up to 4.5 R/hr on contact with the mixed waste drums. In addition, the potential existed for plutonium and toxic characteristic metals to be present in the NaK, resultant from the location of the partial core meltdown of EBR-I in 1955. Moreover, the NaK was susceptible to degradation after more than 40 years of storage in unmonitored conditions. Such degradation raised the possibility of energetic exothermic reactions between the liquid NaK and its crust, which could have consisted of potassium superoxide as well as hydrated sodium/potassium hydroxides.

  5. Method for the safe disposal of alkali metal

    International Nuclear Information System (INIS)

    Johnson, T.R.

    1977-01-01

    Alkali metals such as those employed in liquid metal coolant systems can be safely reacted to form hydroxides by first dissolving the alkali metal in relatively inert metals such as lead or bismuth. The alloy thus formed is contacted with a molten salt including the alkali metal hydroxide and possibly the alkali metal carbonate in the presence of oxygen. This oxidizes the alkali metal to an oxide which is soluble within the molten salt. The salt is separated and contacted with steam or steam--CO 2 mixture to convert the alkali metal oxide to the hydroxide. These reactions can be conducted with minimal hydrogen evolution and with the heat of reaction distributed between the several reaction steps. 5 claims, 1 figure

  6. Devoluming method and device for radioactive metal wastes containing zirconium alloy

    International Nuclear Information System (INIS)

    Komatsu, Masahiko; Wada, Ryutaro.

    1996-01-01

    The present invention concerns a method of sealing radioactive metal wastes in a capsule and compressing the capsule for devoluming treatment. The method comprises a step of carrying radioactive metal wastes into a sealed chamber having a capacity somewhat greater than that of the capsule, a deaerating step of sucking the air in the sealed chamber to attain a substantially vacuum state, a compression-devoluming step of compression-devoluming the capsule by reducing the volume of the sealed chamber and a transporting step of transporting the devolumed capsule from the sealed chamber. The sealed chamber to which the capsule incorporated with radioactive metal wastes containing a zirconium alloy is carried is then deaerated into a substantially vacuum state. Even if ignitable powdery dusts are generated from the radioactive metal wastes crushed by compression-devoluming of the capsule in the succeeding compression-devoluming step, since the air necessary for ignition is not present, ignition of the powdery dusts is prevented. Alternatively, since the inside of the sealed chamber is filled with an inert gas, ignition of the powdery dusts can effectively be prevented. (N.H.)

  7. Radioactive waste processing method

    International Nuclear Information System (INIS)

    Sakuramoto, Naohiko.

    1992-01-01

    When granular materials comprising radioactive wastes containing phosphorus are processed at first in a fluidized bed type furnace, if the granular materials are phosphorus-containing activated carbon, granular materials comprising alkali compound such as calcium hydroxide and barium hydroxide are used as fluidizing media. Even granular materials of slow burning speed can be burnt stably in a fluidizing state by high temperature heat of the fluidizing media, thereby enabling to take a long burning processing time. Accordingly, radioactive activated carbon wastes can be processed by burning treatment. (T.M.)

  8. Waste printing paper as analogous adsorbents for heavy metals in ...

    African Journals Online (AJOL)

    user

    heavy metals uptake from aqueous solutions but the recovery efficacy as economic and environmental ... system. 1 . Wastes containing metals are directly or indirectly discharge into the environment ... According to World health Organization. 5.

  9. Utilization of fly ash for stabilization/solidification of heavy metal contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Dermatas, D.; Meng, X. [Stevens Inst. of Technology, Hoboken, NJ (United States)

    1995-12-01

    Pozzolanic-based stabilization/solidification (S/S) is an effective, yet economic technological alternative to immobilize heavy metals in contaminated soils and sludges. Fly ash waste materials were used along with quicklime (CaO) to immobilize lead, trivalent and hexavalent chromium present in contaminated clayey sand soils. The degree of heavy metal immobilization was evaluated using the Toxicity Characteristic Leaching Procedure (TCLP) as well as controlled extraction experiments. These leaching test results along with X-ray diffraction (XRD), scanning electron microscope and energy dispersive x-ray (SEM-EDX) analyses were also implemented to elucidate the mechanisms responsible for immobilization of the heavy metals under study. Finally, the reusability of the stabilized waste forms in construction applications was also investigated by performing unconfined compressive strength and swell tests. Results suggest that the controlling mechanism for both lead and hexavalent chromium immobilization is surface adsorption, whereas for trivalent chromium it is hydroxide precipitation. Addition of fly ash to the contaminated soils effectively reduced heavy metal leachability well below the non-hazardous regulatory limits. However, quicklime addition was necessary in order to attain satisfactory immobilization levels. Overall, fly ash addition increases the immobilization pH region for all heavy metals tested, and significantly improves the stress-strain properties of the treated solids, thus allowing their reuse as readily available construction materials. The only potential problem associated with this quicklime/fly ash treatment is the excessive formation of the pozzolanic product ettringite in the presence of sulfates. Ettringite, when brought in contact with water, may cause significant swelling and subsequent deterioration of the stabilized matrix. Addition of minimum amounts of barium hydroxide was shown to effectively eliminate ettringite formation.

  10. Electrochemical formation of hydroxide for enhancing carbon dioxide and acid gas uptake by a solution

    Science.gov (United States)

    Rau, Gregory Hudson

    2014-07-01

    A system for forming metal hydroxide from a metal carbonate utilizes a water electrolysis cell having an acid-producing anode and a hydroxyl-producing cathode immersed in a water solution of sufficient ionic content to allow an electric current to pass between the hydroxyl-producing cathode and the acid-producing anode. A metal carbonate is placed in close proximity to the acid-producing anode. A direct current electrical voltage is provided across the acid-producing anode and the hydroxyl-producing cathode sufficient to generate acid at the acid-producing anode and hydroxyl ions at the hydroxyl-producing cathode. The acid dissolves at least part of the metal carbonate into metal and carbonate ions allowing the metal ions to travel toward the hydroxyl-producing cathode and to combine with the hydroxyl ions to form the metal hydroxide. The carbonate ions travel toward the acid-producing anode and form carbonic acid and/or water and carbon dioxide.

  11. Removal of nitrate from ammonium hydroxide solution containing organics by ion exchange method

    International Nuclear Information System (INIS)

    Venugopal Chetty, K.; Gamare, Jayashree S.; Vaidya, V.N.

    2004-01-01

    Removal of nitrate from ammonium hydroxide solution containing HMTA (hexamethyltetramine) and Urea was studied using indigenously available anion exchange resins. This type of waste is produced during nuclear fuel preparation by internal gelation process. The resins used are Tulsion A-27(MP) and Duolite A. 102D. The time of equilibration and capacity of the resins were determined from distribution ratios obtained by equilibrating resin with nitrate solution. The loading, washing and elution behavior of nitrate on these resins were studied using synthetic mixture having similar composition of the waste produced. Elution studies were carried out using sodium hydroxide, hydrochloric acid and ammonium chloride. The studies were also carried out at higher temperature of around 60 degC. The data was compared with that obtained using Dowex 1x4 for the same purpose. (author)

  12. Water Mock-up for the Sodium Waste Treatment Process

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Ho Yun; Kim, Jong Man; Kim, Byung Ho; Lee, Yong Bum [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-05-15

    It is important to safely treat the waste sodium which was produced from the sodium cooled fast reactors and the sodium facilities. About 1.3 tons of sodium waste has accumulated at KAERI from the sodium experiments which have been carried out since 1990. Also, large scaled sodium experiments are scheduled to verify the design of the sodium cooled fast reactor. As a treatment method for the waste sodium produced at the sodium facility, an investigation of the reaction procedure of the waste sodium with the sodium hydroxide aqueous has been developed. The NOAH process was developed in France for the treatment of waste sodium produced from sodium facilities and reactors. In the NOAH process, a small amount of sodium waste is continuously injected into the upper space which is formed on the free surface of the aqueous and slowly reacted with sodium hydroxide aqueous. Since the density of the sodium is lower than that of the aqueous, the injected sodium waste sometimes accumulates above the free surface of the sodium hydroxide aqueous, and its reaction rate becomes slow or suddenly increases. In the improved process, the sodium was injected into a reaction vessel filled with a sodium hydroxide aqueous through an atomizing nozzle installed on a lower level than that of the aqueous to maintain the reaction uniformly. Fig.1 shows the sodium waste process which was proposed in KAERI. The aqueous is composed of 60% sodium hydroxide, and its temperature is about 60 .deg. C. The process is an exothermic reaction. The hydrogen gas is generated, and the concentration of the sodium hydroxide increases in this process. It needs several systems for the process, i.e. a waste sodium injection, a cooling of the aqueous, hydrogen ventilation, and neutralization with nitric acid. The atomizing nozzle was designed to inject the sodium with the nitrogen gas which supplies a heat to the sodium to prevent its solidification and to uniformly mix the sodium with the aqueous. There are

  13. Embedding methods of solidified waste in metal matrices

    International Nuclear Information System (INIS)

    Neumann, W.

    1979-01-01

    The embedding of simulated waste calcines by three different methods (vacuum-pressure casting, centrifugal casting, and metal stirred with the calcines) was investigated. The experimental performance is described and advantages and disadvantages noted. The feasibility of embedding fines by stirring in metal was shown. In addition, an estimation of the influence of porosity on the properties of composites was carried out

  14. Solidification/stabilization of ash from medical waste incineration into geopolymers.

    Science.gov (United States)

    Tzanakos, Konstantinos; Mimilidou, Aliki; Anastasiadou, Kalliopi; Stratakis, Antonis; Gidarakos, Evangelos

    2014-10-01

    In the present work, bottom and fly ash, generated from incinerated medical waste, was used as a raw material for the production of geopolymers. The stabilization (S/S) process studied in this paper has been evaluated by means of the leaching and mechanical properties of the S/S solids obtained. Hospital waste ash, sodium hydroxide, sodium silicate solution and metakaolin were mixed. Geopolymers were cured at 50°C for 24h. After a certain aging time of 7 and 28 days, the strength of the geopolymer specimens, the leachability of heavy metals and the mineralogical phase of the produced geopolymers were studied. The effects of the additions of fly ash and calcium compounds were also investigated. The results showed that hospital waste ash can be utilized as source material for the production of geopolymers. The addition of fly ash and calcium compounds considerably improves the strength of the geopolymer specimens (2-8 MPa). Finally, the solidified matrices indicated that geopolymerization process is able to reduce the amount of the heavy metals found in the leachate of the hospital waste ash. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. THE INFLUENCE OF SELECTED FACTORS ON THE LEACHING OF HEAVY METALS FROM SMELTER WASTE

    Directory of Open Access Journals (Sweden)

    Kamila Mizerna

    2015-07-01

    Full Text Available The paper presents the results of leaching research of selected heavy metals (Pb, Cu, Zn, Ni, Cd, Cr from industrial waste. The impact of waste fragmentation on the level of heavy metals leaching was analyzed. The decrease of copper and zinc release and the increase of nickel leaching were observed with increasing grain size fraction of waste. Furthermore, release of contaminants in different ratio of liquid to solid (L/S = 10 dm3/kg and 2 dm3/kg was studied. Higher concentrations of heavy metals were determined in ratio of L/S = 10 dm3/kg. In order to determine the risk of tested waste to the environment, the results were compared with the current law. This allowed the classification of the waste to hazardous waste.

  16. The study on recycle scheme of the metallic radioactive wastes (II)

    International Nuclear Information System (INIS)

    Shin, J. I.; Park, J. H.; Jung, K. J.

    2003-01-01

    It was understood that regulation criteria for material release varied with countries and that international standards were not setup. But, most advanced countries are continuously studying on the recycling of metallic wastes for the purpose of the reuse of resources and disposal cost reduction. Practically, the advanced countries make a lot of cost profits compared with disposal as their metallic wastes are recycled and reused through technology like melting. The reasonable international standards are also expected to be set in the near future because of the aggressive cooperation between international agencies such as IAEA and NEA toward recycling these wastes. In our case, the recycle criteria for radioactive waste containing radioactive nuclide with long half-life such as Cs-137(half-life: 30y) and Co-60(half-life: 5.26y) including others, which are generated from the nuclear fission or dismantling of nuclear facilities, are not yet established. Therefore, it is required that the recommendation and legalization of the regulatory criteria be carried out for the recycle and reuse of metallic wastes to be generated from the dismantling of domestic nuclear facilities in the future

  17. Analysis of the application of decontamination technologies to radioactive metal waste minimization using expert systems

    Energy Technology Data Exchange (ETDEWEB)

    Bayrakal, Suna [Iowa State Univ., Ames, IA (United States)

    1993-09-30

    Radioactive metal waste makes up a significant portion of the waste currently being sent for disposal. Recovery of this metal as a valuable resource is possible through the use of decontamination technologies. Through the development and use of expert systems a comparison can be made of laser decontamination, a technology currently under development at Ames Laboratory, with currently available decontamination technologies for applicability to the types of metal waste being generated and the effectiveness of these versus simply disposing of the waste. These technologies can be technically and economically evaluated by the use of expert systems techniques to provide a waste management decision making tool that generates, given an identified metal waste, waste management recommendations. The user enters waste characteristic information as input and the system then recommends decontamination technologies, determines residual contamination levels and possible waste management strategies, carries out a cost analysis and then ranks, according to cost, the possibilities for management of the waste. The expert system was developed using information from literature and personnel experienced in the use of decontamination technologies and requires validation by human experts and assignment of confidence factors to the knowledge represented within.

  18. Analysis of the application of decontamination technologies to radioactive metal waste minimization using expert systems

    International Nuclear Information System (INIS)

    Bayrakal, S.

    1993-01-01

    Radioactive metal waste makes up a significant portion of the waste currently being sent for disposal. Recovery of this metal as a valuable resource is possible through the use of decontamination technologies. Through the development and use of expert systems a comparison can be made of laser decontamination, a technology currently under development at Ames Laboratory, with currently available decontamination technologies for applicability to the types of metal waste being generated and the effectiveness of these versus simply disposing of the waste. These technologies can be technically and economically evaluated by the use of expert systems techniques to provide a waste management decision making tool that generates, given an identified metal waste, waste management recommendations. The user enters waste characteristic information as input and the system then recommends decontamination technologies, determines residual contamination levels and possible waste management strategies, carries out a cost analysis and then ranks, according to cost, the possibilities for management of the waste. The expert system was developed using information from literature and personnel experienced in the use of decontamination technologies and requires validation by human experts and assignment of confidence factors to the knowledge represented within

  19. The study of heavy metals leaching from waste foundry sands using a one-step extraction

    Directory of Open Access Journals (Sweden)

    Bożym Marta

    2017-01-01

    Full Text Available There are a number of leaching test which are used to evaluate the effect of foundry waste disposal on the environment (TCLP, SPLP, ASTM at al.. Because the spent foundry sand are usually deposited at the ground level and they have a similar structure to the soil, survey mobility of metals using the same methods seems appropriate. One-step extraction allows for the evaluation of the mobility and bioavailability of metals in soil and waste. Waste foundry sands have been successfully used as a component in manufactured soils in U.S., but concern over metal contamination must be eliminated before considering this direction of use. The study evaluated the leaching of heavy metals (Cd, Pb, Cu, Zn, Cr, Ni from deposited waste foundry sands. The overall, as well as heavy metals were extracted by different type of extractants: H2O, CH3COOH, HCl, EDTA, MgCl2 and NaCOOH. These extractants are most commonly used to study the mobility and bioavailability of metals in soil and waste. In the present study applicable standards and methodology described in the literature in analysis were used. The results allowed to evaluate the bioavailability of metals leached from those wastes.

  20. Preliminary study on recycling of metallic waste from decommissioning of nuclear power plant for cask

    International Nuclear Information System (INIS)

    Ohe, Koichiro; Kato, Osamu; Saegusa, Toshiari

    1999-01-01

    Preliminary study was made on technology required to recycle of metallic waste from decommissioning for spent fuel storage cask and on quantity of the cask which can be produced by the metallic waste. The technical and institutional issues for the recycling were studied. The metallic waste from decommissioning may be technically used to a certain degree for manufacturing the casks. However, there were some technical issues to be solved. For example, the manufacturing factories should be established. The radioactive waste from the factories with radiation control should be handled and treated carefully. Quality of the cask should be properly controlled. The 'Clearance Levels' which allows to recycle decommissioning waste have been hardly enacted in Japan. Technical and economic evaluation on recycling of metallic waste from decommissioning for spent fuel storage cask should be conducted again after progress in recycling of radioactive waste of which radioactivity is below the 'Clearance Levels' in Japan. (author)

  1. Selection of barrier metals for a waste package in tuff

    International Nuclear Information System (INIS)

    Russell, E.W.; McCright, R.D.; O'Neal, W.C.

    1983-09-01

    The Nevada Nuclear Waste Storage Investigation (NNWSI) project under the Civilian Radioactive Waste Management Program is planning a repository at Yucca Mountain at the Nevada Test Site for isolation of high-level nuclear waste. LLNL is developing designs for an engineered barrier system containing several barriers such as the waste form, a canister and/or an overpack, packing, and near field host rock. The selection of metal containment barriers is addressed. 13 references

  2. Children with health impairments by heavy metals in an e-waste recycling area

    NARCIS (Netherlands)

    Zeng, Xiang; Xu, Xijin; Boezen, H. Marike; Huo, Xia

    E-waste recycling has become a global environmental health issue. Pernicious chemicals escape into the environment due to informal and nonstandard e-waste recycling activities involving manual dismantling, open burning to recover heavy metals and open dumping of residual fractions. Heavy metals

  3. Sizing and melting development activities using noncontaminated metal at the Waste Experimental Reduction Facility

    International Nuclear Information System (INIS)

    Larsen, M.M.; Logan, J.A.

    1984-05-01

    EG and G Idaho, Inc., has established the Waste Experimental Reduction Facility (WERF) at the Idaho National Engineering Laboratory (INEL) to develop the capability to reduce the volume that low-level beta/gamma wastes occupy at the disposal site. The work effort at WERF includes a waste sizing development activity (WSDA), a waste melting development activity (WMDA), and a waste incineration development activity (WIDA). This report describes work and developments to date in the WSDA and WMDA with noncontaminated metallic waste in preparation for operations at WERF involving beta/gamma-contaminated metal

  4. TREATMENT OF METAL-LADEN HAZARDOUS WASTES WITH ADVANCED CLEAN COAL TECHNOLOGY BY-PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    James T. Cobb, Jr.

    2003-09-12

    Metal-laden wastes can be stabilized and solidified using advanced clean coal technology by-products (CCTBs)--fluid bed combustor ash and spray drier solids. These utility-generated treatment chemicals are available for purchase through brokers, and commercial applications of this process are being practiced by treaters of metal-laden hazardous waste. A complex of regulations governs this industry, and sensitivities to this complex has discouraged public documentation of treatment of metal-laden hazardous wastes with CCTBs. This report provides a comprehensive public documentation of laboratory studies that show the efficacy of the stabilization and solidification of metal-laden hazardous wastes--such as lead-contaminated soils and sandblast residues--through treatment with CCTBs. It then describes the extensive efforts that were made to obtain the permits allowing a commercial hazardous waste treater to utilize CCTBs as treatment chemicals and to install the equipment required to do so. It concludes with the effect of this lengthy process on the ability of the treatment company to realize the practical, physical outcome of this effort, leading to premature termination of the project.

  5. Development for recycle of dismantled metal wastes by decommissioning of NPP

    International Nuclear Information System (INIS)

    Asami, Tomohiro; Sato, Hiroshi; Hatakeyama, Mutsuo

    2007-01-01

    For recycle of dismantled metal wastes generated by the decommissioning of nuclear power plant, we examined a melting test for melting characterization of stainless steel scrap, designed the conceptual process to produce the recycle products, and developed a recycle cost evaluation code which is useful to make a rational planning for the waste management program (cost, determination of process, etc.) of these metal wastes. This report gives the summary of these development carried out from 2001 to 2005. This work was performed under the sponsorship of Ministry of Education, Culture, Sports, Science and Technology of Japan. (author)

  6. Nickel hydroxide positive electrode for alkaline rechargeable battery

    Science.gov (United States)

    Young, Kwo; Wang, Lixin; Mays, William; Reichman, Benjamin; Chao-Ian, Hu; Wong, Diana; Nei, Jean

    2018-02-20

    Certain nickel hydroxide active cathode materials for use in alkaline rechargeable batteries are capable of transferring >1.3 electrons per Ni atom under reversible electrochemical conditions. The specific capacity of the nickel hydroxide active materials is for example .gtoreq.325 mAh/g. The cathode active materials exhibit an additional discharge plateau near 0.8 V vs. a metal hydride (MH) anode. Ni in an oxidation state of less than 2, such as Ni.sup.1+, is able to participate in electrochemical reactions when using the present cathode active materials. It is possible that up to 2.3 electrons, up to 2.5 electrons or more may be transferred per Ni atom under electrochemical conditions.

  7. Nickel hydroxide positive electrode for alkaline rechargeable battery

    Science.gov (United States)

    Young, Kwo; Wang, Lixin; Mays, William; Reichman, Benjamin; Chao-Ian, Hu; Wong, Diana; Nei, Jean

    2018-04-03

    Certain nickel hydroxide active cathode materials for use in alkaline rechargeable batteries are capable of transferring >1.3 electrons per Ni atom under reversible electrochemical conditions. The specific capacity of the nickel hydroxide active materials is for example .gtoreq.325 mAh/g. The cathode active materials exhibit an additional discharge plateau near 0.8 V vs. a metal hydride (MH) anode. Ni in an oxidation state of less than 2, such as Ni.sup.1+, is able to participate in electrochemical reactions when using the present cathode active materials. It is possible that up to 2.3 electrons, up to 2.5 electrons or more may be transferred per Ni atom under electrochemical conditions.

  8. Heavy metal contamination of surface soil in electronic waste dismantling area: site investigation and source-apportionment analysis.

    Science.gov (United States)

    Jinhui Li; Huabo Duan; Pixing Shi

    2011-07-01

    The dismantling and disposal of electronic waste (e-waste) in developing countries is causing increasing concern because of its impacts on the environment and risks to human health. Heavy-metal concentrations in the surface soils of Guiyu (Guangdong Province, China) were monitored to determine the status of heavy-metal contamination on e-waste dismantling area with a more than 20 years history. Two metalloids and nine metals were selected for investigation. This paper also attempts to compare the data among a variety of e-waste dismantling areas, after reviewing a number of heavy-metal contamination-related studies in such areas in China over the past decade. In addition, source apportionment of heavy metal in the surface soil of these areas has been analysed. Both the MSW open-burning sites probably contained invaluable e-waste and abandoned sites formerly involved in informal recycling activities are the new sources of soil-based environmental pollution in Guiyu. Although printed circuit board waste is thought to be the main source of heavy-metal emissions during e-waste processing, requirement is necessary to soundly manage the plastic separated from e-waste, which mostly contains heavy metals and other toxic substances.

  9. Assessment of toxic metals in waste personal computers

    International Nuclear Information System (INIS)

    Kolias, Konstantinos; Hahladakis, John N.; Gidarakos, Evangelos

    2014-01-01

    Highlights: • Waste personal computers were collected and dismantled in their main parts. • Motherboards, monitors and plastic housing were examined in their metal content. • Concentrations measured were compared to the RoHS Directive, 2002/95/EC. • Pb in motherboards and funnel glass of devices released <2006 was above the limit. • Waste personal computers need to be recycled and environmentally sound managed. - Abstract: Considering the enormous production of waste personal computers nowadays, it is obvious that the study of their composition is necessary in order to regulate their management and prevent any environmental contamination caused by their inappropriate disposal. This study aimed at determining the toxic metals content of motherboards (printed circuit boards), monitor glass and monitor plastic housing of two Cathode Ray Tube (CRT) monitors, three Liquid Crystal Display (LCD) monitors, one LCD touch screen monitor and six motherboards, all of which were discarded. In addition, concentrations of chromium (Cr), cadmium (Cd), lead (Pb) and mercury (Hg) were compared with the respective limits set by the RoHS 2002/95/EC Directive, that was recently renewed by the 2012/19/EU recast, in order to verify manufacturers’ compliance with the regulation. The research included disassembly, pulverization, digestion and chemical analyses of all the aforementioned devices. The toxic metals content of all samples was determined using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The results demonstrated that concentrations of Pb in motherboards and funnel glass of devices with release dates before 2006, that is when the RoHS Directive came into force, exceeded the permissible limit. In general, except from Pb, higher metal concentrations were detected in motherboards in comparison with plastic housing and glass samples. Finally, the results of this work were encouraging, since concentrations of metals referred in the RoHS Directive were found in

  10. Assessment of toxic metals in waste personal computers

    Energy Technology Data Exchange (ETDEWEB)

    Kolias, Konstantinos; Hahladakis, John N., E-mail: john_chach@yahoo.gr; Gidarakos, Evangelos, E-mail: gidarako@mred.tuc.gr

    2014-08-15

    Highlights: • Waste personal computers were collected and dismantled in their main parts. • Motherboards, monitors and plastic housing were examined in their metal content. • Concentrations measured were compared to the RoHS Directive, 2002/95/EC. • Pb in motherboards and funnel glass of devices released <2006 was above the limit. • Waste personal computers need to be recycled and environmentally sound managed. - Abstract: Considering the enormous production of waste personal computers nowadays, it is obvious that the study of their composition is necessary in order to regulate their management and prevent any environmental contamination caused by their inappropriate disposal. This study aimed at determining the toxic metals content of motherboards (printed circuit boards), monitor glass and monitor plastic housing of two Cathode Ray Tube (CRT) monitors, three Liquid Crystal Display (LCD) monitors, one LCD touch screen monitor and six motherboards, all of which were discarded. In addition, concentrations of chromium (Cr), cadmium (Cd), lead (Pb) and mercury (Hg) were compared with the respective limits set by the RoHS 2002/95/EC Directive, that was recently renewed by the 2012/19/EU recast, in order to verify manufacturers’ compliance with the regulation. The research included disassembly, pulverization, digestion and chemical analyses of all the aforementioned devices. The toxic metals content of all samples was determined using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The results demonstrated that concentrations of Pb in motherboards and funnel glass of devices with release dates before 2006, that is when the RoHS Directive came into force, exceeded the permissible limit. In general, except from Pb, higher metal concentrations were detected in motherboards in comparison with plastic housing and glass samples. Finally, the results of this work were encouraging, since concentrations of metals referred in the RoHS Directive were found in

  11. Differential potentiometric titration: development of a methodology for determining the point of zero charge of metal (hydr)oxides by one titration curve.

    Science.gov (United States)

    Bourikas, Kyriakos; Kordulis, Christos; Lycourghiotis, Alexis

    2005-06-01

    A new methodology is presented, called differential potentiometric titration (DPT), which allows the determination of the point of zero charge (pzc) of metal (hydr)oxides using only one potentiometric curve. By performing extensive simulations of potentiometric titrations for various model (hydr)oxides, we found that an inflection point in a H+(cons,surf) versus pH potentiometric curve (H+(cons,surf): hydrogen ions consumed on the surface of the (hydr)oxide) and a peak in the corresponding differential curve, dH+(cons,surf)/dpH versus pH, appear at a pH equal to the pzc assumed for a model (hydr)oxide. This distinguishable peak appears at the same position irrespective of the surface ionization and the interfacial model adopted as well as the assumed ionic strength. It was found that the aforementioned peak also appears in the high-resolution differential potentiometric curves experimentally determined for four oxides (SiO2, TiO2, gamma-Al2O3, and MgO) that are widely used in various environmental and other technological applications. The application of DPT to the above-mentioned oxides provided practically the same pzc values as the corresponding ones achieved by using four different techniques as well as the corresponding isoelectric point (iep) values determined by microelectrophoresis. Differences between the pzc and iep values determined using various techniques in the case of MgO were attributed to the increasing dissolution of this oxide as pH decreases and the adsorption of cations (Mg2+, Na+) on the MgO/electrolytic solution interface.

  12. 40 CFR Appendix B to Part 414 - Complexed Metal-Bearing Waste Streams

    Science.gov (United States)

    2010-07-01

    ... 414—Complexed Metal-Bearing Waste Streams Chromium Azo dye intermediates/Substituted diazonium salts + coupling compounds Vat dyes Acid dyes Azo dyes, metallized/Azo dye + metal acetate Acid dyes, Azo...

  13. Treatment and conditioning of metallic intermediate level waste

    International Nuclear Information System (INIS)

    Lidar, Per; Larsson, Arne; Huutoniemi, Tommi; Blank, Eva; Elfwing, Mattias

    2014-01-01

    In 2011 SKB started an R and D program for evaluating different disposal concepts for LL-LILW. The purpose was to develop alternative repository concepts and conditioning methods for LL-LILW and to evaluate and compare them from a range of parameters. The goal is to present a comparison between identified repository concepts by 2013. The material should be of such a quality that SKB can make decisions of which concepts that are to be further investigated in a safety analysis. As a part of the R and D program for the LL-LILW disposal facility, Studsvik was assigned to investigate whether melting of metallic LL-LILW is technically feasible and, if so, what the requirements are to build and operate such a facility. Specific concern was given to the following metallic components: - Core components and reactor internals from both boiling water reactors (BWRs) and pressurized water reactors (PWRs). - Reactor pressure vessels from PWRs. The paper presents a feasibility study of a melting facility for core components and reactor internals. An overview is given of how such a facility for treatment of intermediate level waste might be designed, constructed and operated and highlights both the possibilities and challenges. A cost estimate and a risk analysis are presented in order to make a conclusion of the technical feasibility of such a facility. Based on the Studsvik authors' experience in operating a low level waste melting facility, their conclusion is presented in the paper, considering cost of constructing and operating such a facility, in conjunction with the radio-logical risks associated with operation and the benefits to disposal and long term safety. Studsvik also investigated alternative techniques for embedding of metallic ILW components. Embedding of radioactive metallic ILW components protects the component from corrosion and leakage of radionuclides from repository to biosphere can thereby be both delayed and decreased. Conditioning by embedding has

  14. Radioactive waste solidification material

    International Nuclear Information System (INIS)

    Nishihara, Yukio; Wakuta, Kuniharu; Ishizaki, Kanjiro; Koyanagi, Naoaki; Sakamoto, Hiroyuki; Uchida, Ikuo.

    1992-01-01

    The present invention concerns a radioactive waste solidification material containing vermiculite cement used for a vacuum packing type waste processing device, which contains no residue of calcium hydroxide in cement solidification products. No residue of calcium hydroxide means, for example, that peak of Ca(OH) 2 is not recognized in an X ray diffraction device. With such procedures, since calcium sulfoaluminate clinker and Portland cement themselves exhibit water hardening property, and slugs exhibit hydration activity from the early stage, the cement exhibits quick-hardening property, has great extension of long term strength, further, has no shrinking property, less dry- shrinkage, excellent durability, less causing damages such as cracks and peeling as processing products of radioactive wastes, enabling to attain highly safe solidification product. (T.M.)

  15. Initial Evaluation of Processing Methods for an Epsilon Metal Waste Form

    International Nuclear Information System (INIS)

    Crum, Jarrod V.; Strachan, Denis M.; Zumhoff, Mac R.

    2012-01-01

    During irradiation of nuclear fuel in a reactor, the five metals, Mo, Pd, Rh, Ru, and Tc, migrate to the fuel grain boundaries and form small metal particles of an alloy known as epsilon metal ((var e psilon)-metal). When the fuel is dissolved in a reprocessing plant, these metal particles remain behind with a residue - the undissolved solids (UDS). Some of these same metals that comprise this alloy that have not formed the alloy are dissolved into the aqueous stream. These metals limit the waste loading for a borosilicate glass that is being developed for the reprocessing wastes. Epsilon metal is being developed as a waste form for the noble metals from a number of waste streams in the aqueous reprocessing of used nuclear fuel (UNF) - (1) the (var e psilon)-metal from the UDS, (2) soluble Tc (ion-exchanged), and (3) soluble noble metals (TRUEX raffinate). Separate immobilization of these metals has benefits other than allowing an increase in the glass waste loading. These materials are quite resistant to dissolution (corrosion) as evidenced by the fact that they survive the chemically aggressive conditions in the fuel dissolver. Remnants of (var e psilon)-metal particles have survived in the geologically natural reactors found in Gabon, Africa, indicating that they have sufficient durability to survive for ∼ 2.5 billion years in a reducing geologic environment. Additionally, the (var e psilon)-metal can be made without additives and incorporate sufficient foreign material (oxides) that are also present in the UDS. Although (var e psilon)-metal is found in fuel and Gabon as small particles (∼10 (micro)m in diameter) and has survived intact, an ideal waste form is one in which the surface area is minimized. Therefore, the main effort in developing (var e psilon)-metal as a waste form is to develop a process to consolidate the particles into a monolith. Individually, these metals have high melting points (2617 C for Mo to 1552 C for Pd) and the alloy is expected

  16. Melting of contaminated metallic waste

    International Nuclear Information System (INIS)

    Lee, Y.-S.; Cheng, S.-Y.; Kung, H.-T.; Lin, L.-F.

    2004-01-01

    Approximately 100 tons of contaminated metallic wastes were produced each year due to maintenance for each TPC's nuclear power reactor and it was roughly estimated that there will be 10,000 tons of metallic scraps resulted from decommissioning of each reactor in the future. One means of handling the contaminated metal is to melt it. Melting process owns not only volume reduction which saves the high cost of final disposal but also resource conservation and recycling benefits. Melting contaminated copper and aluminum scraps in the laboratory scale have been conducted at INER. A total of 546 kg copper condenser tubes with a specific activity of about 2.7 Bq/g was melted in a vacuum induction melting facility. Three types of products, ingot, slag and dust were derived from the melting process, with average activities of 0.10 Bq/g, 2.33 Bq/g and 84.3 Bq/g respectively. After the laboratory melting stage, a pilot plant with a 500 kg induction furnace is being designed to melt the increasingly produced contaminated metallic scraps from nuclear facilities and to investigate the behavior of different radionuclides during melting. (author)

  17. Magnesium Hydroxide

    Science.gov (United States)

    Magnesium hydroxide is used on a short-term basis to treat constipation.This medication is sometimes prescribed ... Magnesium hydroxide come as a tablet and liquid to take by mouth. It usually is taken as ...

  18. Aluminum Hydroxide

    Science.gov (United States)

    Aluminum hydroxide is used for the relief of heartburn, sour stomach, and peptic ulcer pain and to ... Aluminum hydroxide comes as a capsule, a tablet, and an oral liquid and suspension. The dose and ...

  19. Measurement of total alpha activity of neptunium, plutonium, and americium in highly radioactive Hanford waste by iron hydroxide precipitation and 2-heptanone solvent extraction

    International Nuclear Information System (INIS)

    Maiti, T.C.; Kaye, J.H.

    1992-06-01

    An improved method has been developed to concentrate the major alpha-emitting actinide elements neptunium, plutonium, and americium from samples with high salt content such as those resulting from efforts to characterize Hanford storage tank waste. Actinide elements are concentrated by coprecipitation of their hydroxides using iron carrier. The iron is removed by extraction from 8M HCI with 2-heptanone. The actinide elements remain in the aqueous phase free from salts, iron, and long-lived fission products. Recoveries averaged 98 percent

  20. Study of the migration of toxic metals in steelmaking waste using radioactive tracing

    International Nuclear Information System (INIS)

    Andre, C.; Jauzein, M.; Charentus, T.; Margrita, R.; Dechelette, O.

    1991-01-01

    The danger presented by toxic metals contained in steelmaking wastes put into slag piles may be neutralized by suitably chosen alternation of these wastes when they are deposited. Presentation of a study method using radioactive tracing of the migration of toxic metal (cadmium, zinc, chromium) in steelmaking wastes (slag, blast furnace sludge). This non destructive method was used in columns in the laboratory, but may be used in on-site slag piles [fr

  1. Heavy metal removal and recovery using microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Wilde, E.W. (Westinghouse Savannah River Co., Aiken, SC (United States)); Benemann, J.R. (Benemann (J.R.), Pinole, CA (United States))

    1991-02-01

    Microorganisms -- bacteria, fungi, and microalgae -- can accumulate relatively large amounts of toxic heavy metals and radionuclides from the environment. These organisms often exhibit specificity for particular metals. The metal content of microbial biomass can be a substantial fraction of total dry weight with concentration factors (metal in dry biomass to metal in solution) exceeding one million in some cases. Both living and inert (dead) microbial biomass can be used to reduce heavy metal concentrations in contaminated waters to very low levels -- parts per billion and even lower. In many respects (e.g. specificity, residual metal concentrations, accumulation factors, and economics) microbial bioremoval processes can be superior to conventional processes, such as ion exchange and caustic (lime or hydroxide) precipitation for heavy metals removal from waste and contaminated waters. Thus, bioremoval could be developed to contribute to the clean-up of wastes at the Savannah River Site (SRS) and other DOE facilities. However, the potential advantages of bioremoval processes must still be developed into practical operating systems. A detailed review of the literature suggests that appropriate bioremoval processes could be developed for the SRS. There is great variability from one biomass source to another in bioremoval capabilities. Bioremoval is affected by pH, other ions, temperature, and many other factors. The biological (living vs. dead) and physical (immobilized vs. dispersed) characteristics of the biomass also greatly affect metal binding. Even subtle differences in the microbial biomass, such as the conditions under which it was cultivated, can have major effects on heavy metal binding.

  2. Heavy metal removal and recovery using microorganisms

    International Nuclear Information System (INIS)

    Wilde, E.W.; Benemann, J.R.

    1991-02-01

    Microorganisms -- bacteria, fungi, and microalgae -- can accumulate relatively large amounts of toxic heavy metals and radionuclides from the environment. These organisms often exhibit specificity for particular metals. The metal content of microbial biomass can be a substantial fraction of total dry weight with concentration factors (metal in dry biomass to metal in solution) exceeding one million in some cases. Both living and inert (dead) microbial biomass can be used to reduce heavy metal concentrations in contaminated waters to very low levels -- parts per billion and even lower. In many respects (e.g. specificity, residual metal concentrations, accumulation factors, and economics) microbial bioremoval processes can be superior to conventional processes, such as ion exchange and caustic (lime or hydroxide) precipitation for heavy metals removal from waste and contaminated waters. Thus, bioremoval could be developed to contribute to the clean-up of wastes at the Savannah River Site (SRS) and other DOE facilities. However, the potential advantages of bioremoval processes must still be developed into practical operating systems. A detailed review of the literature suggests that appropriate bioremoval processes could be developed for the SRS. There is great variability from one biomass source to another in bioremoval capabilities. Bioremoval is affected by pH, other ions, temperature, and many other factors. The biological (living vs. dead) and physical (immobilized vs. dispersed) characteristics of the biomass also greatly affect metal binding. Even subtle differences in the microbial biomass, such as the conditions under which it was cultivated, can have major effects on heavy metal binding

  3. Interaction of pristine hydrotalcite-like layered double hydroxides ...

    Indian Academy of Sciences (India)

    1783–1790. c Indian Academy of Sciences. ... adversely impacts the ability of the metal hydroxide layer to interact with CO2 in the gas ... CO2 is a greenhouse gas and the bulk of anthropogenic CO2 ... decomposes by the release of gaseous CO2 and water in ... systems such as [Co–Al] LDH the decomposition tempera-.

  4. Growth and metal bioconcentration by conspecific freshwater macroalgae cultured in industrial waste water.

    Science.gov (United States)

    Ellison, Michael B; de Nys, Rocky; Paul, Nicholas A; Roberts, David A

    2014-01-01

    The bioremediation of industrial waste water by macroalgae is a sustainable and renewable approach to the treatment of waste water produced by multiple industries. However, few studies have tested the bioremediation of complex multi-element waste streams from coal-fired power stations by live algae. This study compares the ability of three species of green freshwater macroalgae from the genus Oedogonium, isolated from different geographic regions, to grow in waste water for the bioremediation of metals. The experiments used Ash Dam water from Tarong power station in Queensland, which is contaminated by multiple metals (Al, Cd, Ni and Zn) and metalloids (As and Se) in excess of Australian water quality guidelines. All species had consistent growth rates in Ash Dam water, despite significant differences in their growth rates in "clean" water. A species isolated from the Ash Dam water itself was not better suited to the bioremediation of that waste water. While there were differences in the temporal pattern of the bioconcentration of metals by the three species, over the course of the experiment, all three species bioconcentrated the same elements preferentially and to a similar extent. All species bioconcentrated metals (Cu, Mn, Ni, Cd and Zn) more rapidly than metalloids (As, Mo and Se). Therefore, bioremediation in situ will be most rapid and complete for metals. Overall, all three species of freshwater macroalgae had the ability to grow in waste water and bioconcentrate elements, with a consistent affinity for the key metals that are regulated by Australian and international water quality guidelines. Together, these characteristics make Oedogonium a clear target for scaled bioremediation programs across a range of geographic regions.

  5. Growth and metal bioconcentration by conspecific freshwater macroalgae cultured in industrial waste water

    Directory of Open Access Journals (Sweden)

    Michael B. Ellison

    2014-05-01

    Full Text Available The bioremediation of industrial waste water by macroalgae is a sustainable and renewable approach to the treatment of waste water produced by multiple industries. However, few studies have tested the bioremediation of complex multi-element waste streams from coal-fired power stations by live algae. This study compares the ability of three species of green freshwater macroalgae from the genus Oedogonium, isolated from different geographic regions, to grow in waste water for the bioremediation of metals. The experiments used Ash Dam water from Tarong power station in Queensland, which is contaminated by multiple metals (Al, Cd, Ni and Zn and metalloids (As and Se in excess of Australian water quality guidelines. All species had consistent growth rates in Ash Dam water, despite significant differences in their growth rates in “clean” water. A species isolated from the Ash Dam water itself was not better suited to the bioremediation of that waste water. While there were differences in the temporal pattern of the bioconcentration of metals by the three species, over the course of the experiment, all three species bioconcentrated the same elements preferentially and to a similar extent. All species bioconcentrated metals (Cu, Mn, Ni, Cd and Zn more rapidly than metalloids (As, Mo and Se. Therefore, bioremediation in situ will be most rapid and complete for metals. Overall, all three species of freshwater macroalgae had the ability to grow in waste water and bioconcentrate elements, with a consistent affinity for the key metals that are regulated by Australian and international water quality guidelines. Together, these characteristics make Oedogonium a clear target for scaled bioremediation programs across a range of geographic regions.

  6. Selection of barrier metals for a waste package in tuff

    International Nuclear Information System (INIS)

    Russell, E.W.; McCright, R.D.; O'Neal, W.C.

    1983-10-01

    The Nevada Nuclear Waste Storage Investigations (NNWSI) project under the Civilian Radioactive Waste Management Program is planning a repository at Yucca Mountain at the Nevada Test Site for isolation of high-level nuclear waste. Lawrence Livermore National Laboratory is developing designs for an engineered barrier system containing several barriers such as the waste form, a canister and/or an overpack, packing, and near field host rock. In this paper we address the selection of metal containment barriers. 13 references, 4 tables

  7. Corrosion of Metal Inclusions In Bulk Vitrification Waste Packages

    Energy Technology Data Exchange (ETDEWEB)

    Bacon, Diana H.; Pierce, Eric M.; Wellman, Dawn M.; Strachan, Denis M.; Josephson, Gary B.

    2006-07-31

    The primary purpose of the work reported here is to analyze the potential effect of the release of technetium (Tc) from metal inclusions in bulk vitrification waste packages once they are placed in the Integrated Disposal Facility (IDF). As part of the strategy for immobilizing waste from the underground tanks at Hanford, selected wastes will be immobilized using bulk vitrification. During analyses of the glass produced in engineering-scale tests, metal inclusions were found in the glass product. This report contains the results from experiments designed to quantify the corrosion rates of metal inclusions found in the glass product from AMEC Test ES-32B and simulations designed to compare the rate of Tc release from the metal inclusions to the release of Tc from glass produced with the bulk vitrification process. In the simulations, the Tc in the metal inclusions was assumed to be released congruently during metal corrosion as soluble TcO4-. The experimental results and modeling calculations show that the metal corrosion rate will, under all conceivable conditions at the IDF, be dominated by the presence of the passivating layer and corrosion products on the metal particles. As a result, the release of Tc from the metal particles at the surfaces of fractures in the glass releases at a rate similar to the Tc present as a soluble salt. The release of the remaining Tc in the metal is controlled by the dissolution of the glass matrix. To summarize, the release of 99Tc from the BV glass within precipitated Fe is directly proportional to the diameter of the Fe particles and to the amount of precipitated Fe. However, the main contribution to the Tc release from the iron particles is over the same time period as the release of the soluble Tc salt. For the base case used in this study (0.48 mass% of 0.5 mm diameter metal particles homogeneously distributed in the BV glass), the release of 99Tc from the metal is approximately the same as the release from 0.3 mass% soluble Tc

  8. Immobilization of metal wastes by reaction with H2S in anoxic basins: concept and elaboration.

    Science.gov (United States)

    Schuiling, R D

    2013-10-01

    Metal wastes are produced in large quantities by a number of industries. Their disposal in isolated waste deposits is certain to cause many subsequent problems, because every material will sooner or later return to the geochemical cycle. The sealing of disposal sites usually starts to leak, often within a short time after the disposal site has been filled. The contained heavy metals are leached from the waste deposit and will contaminate the soil and the groundwater. It is evident that storage as metal sulfides in a permanently anoxic environment is the only safe way to handle metal wastes. The world's largest anoxic basin, the Black Sea, can serve as a georeactor. The metal wastes are sustainably transformed into harmless and immobile solids. These are incorporated in the lifeless bottom muds, where they are stored for millions of years.

  9. Solidification of metal chloride waste from pyrochemical process via dechlorination-chlorination reaction system

    Energy Technology Data Exchange (ETDEWEB)

    Park, H.S.; Cho, I.H.; Lee, K.R.; Choi, J.H.; Eun, H.C.; Kim, I.T.; Park, G.I. [Korea Atomic Energy Research Inst., Deajeon (Korea, Republic of)

    2014-07-01

    The metal chloride wastes generated from the pyro-chemical process to recover uranium and TRUs has been considered as a problematic waste due to the high volatility and low compatibility with conventional silicate glass. Our research group has suggested the dechlorination approach for the solidification of this kind of waste by using a synthetic composite, SAP (SiO{sub 2}-Al{sub 2}O{sub 3}-P{sub 2}O{sub 5}). During the dechlorination, metal elements are chemically interacted with the inorganic composite, SAP, while chlorine is vaporized as gaseous chlorine. Metal elements in the salt were immobilized into phosphate and silicate glass which are uniformly distributed in tens of nm scale. During the dechlorination, gaseous chlorine is captured by Li{sub 2}O-Li{sub 2}O{sub 2} composite that can be converted into metal chloride (LiCl). About 98wt% of oxide composite was converted into LiCl that can be used as an electrolyte in the electrochemical process. The method suggested in this study can provide a chance to minimize the waste volume for the final disposal of salt wastes from a pyro-chemical process. (author)

  10. The study on the overseas recycling technology of the radioactive metallic wastes

    International Nuclear Information System (INIS)

    Kim, H. R.; Jung, Y. S.; Sin, J. I.

    2002-01-01

    It was understood that regulation criteria for material release varied with countries and that international standards were not setup. But, most advanced countries are continuously studying on the recycling of metallic wastes for the purpose of the reuse of resources and disposal cost reduction. Practically, the advanced countries make a lot of cost profits compared with disposal as their metallic wastes are recycled and reused through technology like melting. In our case, the recycle criteria for radioactive waste containing radioactive nuclide with long half-life such as Cs-137(half-life: 30y) and Co-60(half-life: 5.26y) including others, which are generated from the nuclear fission or dismantling of nuclear facilities, are not yet established. Therefore, it is required that the recommendation and legalization of the regulatory criteria be carried out for the recycle and reuse of metallic wastes to be generated from the dismantling of domestic nuclear facilities in the future

  11. Comparative studies on acid leaching of zinc waste materials

    Science.gov (United States)

    Rudnik, Ewa; Włoch, Grzegorz; Szatan, Leszek

    2017-11-01

    Three industrial waste materials were characterized in terms of their elemental and phase compositions, leaching behaviour in 10% sulfuric acid solution as well as leaching thermal effects. Slag from melting of mixed metallic scrap contained about 50% Zn and 10% Pb. It consisted mainly of various oxides and oxy-chlorides of metals. Zinc spray metallizing dust contained about 77% Zn in form of zinc and/or zinc-iron oxides, zinc metal and Zn-Fe intermetallic. Zinc ash from hot dip galvanizing was a mixture of zinc oxide, metallic zinc and zinc hydroxide chloride and contained about 80% Zn. Dissolution efficiency of zinc from the first material was 80% (independently on the solid to liquid ratio, 50-150 kg/m3), while decrease of the efficacy from 80% to 60% with increased solid to liquid ratio for the two remaining materials was observed. Both increase in the temperature (20 °C to 35 °C) and agitation rate (300 rpm to 900 rpm) did not improve seriously the leaching results. In all cases, transfer of zinc ions to the leachate was accompanied by different levels of solution contamination, depending on the type of the waste. Leaching of the materials was exothermic with the similar reaction heats for two high oxide-type products (slag, zinc ash) and higher values for the spray metallizing dust.

  12. Radiochemical investigation of the coprecipitation of microamounts of some hydrolyzable elements with metal hydroxides and metal oxides. Pt. 5

    International Nuclear Information System (INIS)

    Plotnikov, V.I.; Safonov, I.I.

    1979-12-01

    Investigation of the coprecipitation of various amounts of iron (III) (between 1 μg and 3.5 mg) with hydroxides of Sn(IV), Ga, Th, Sc, Be, Cd, and Mg as a function of the pH value of the solution. It is shown that the precipitation of the iron (III) with the precipitates of the hydroxides of Be, Cd, Ga, and Sc, which are of lower acidity compared with the microcomponent, is preceded by an acido-basic reaction of Fe(III) with the ions of the macrocomponent. The beginning of this reaction has been observed to coincide with the occurrence of its primary hydrolytical forms in the solution. It is furthermore intensified with decreasing difference in the acidic properties of iron (III) and the other element taking part in the reaction. The neutral hydroxide complex Fe(OH) 0 3 is shown to be the principal coprecipitated form of the iron (III). The coprecipitation of microquantities of iron (III) with tin (IV) hydroxide has been chosen as an example to illustrate the effect of additions of Th, Sc, and Be ions equimolar to the collector. The observed quantitative increase of the microcomponent in the solution is suggested to mainly result from the decrease of the hydrolytical degree of precipitation of tin (IV) due to the interaction of the latter with the ions of impurities. (orig.) 891 RSH/orig. 892 HIS [de

  13. Children with health impairments by heavy metals in an e-waste recycling area.

    Science.gov (United States)

    Zeng, Xiang; Xu, Xijin; Boezen, H Marike; Huo, Xia

    2016-04-01

    E-waste recycling has become a global environmental health issue. Pernicious chemicals escape into the environment due to informal and nonstandard e-waste recycling activities involving manual dismantling, open burning to recover heavy metals and open dumping of residual fractions. Heavy metals derived from electronic waste (e-waste), such as, lead (Pb), cadmium (Cd), chromium (Cr), manganese (Mn), nickel (Ni), mercury (Hg), arsenic (As), copper (Cu), zinc (Zn), aluminum (Al) and cobalt (Co), differ in their chemical composition, reaction properties, distribution, metabolism, excretion and biological transmission. Our previous studies showed that heavy metal exposure have adverse effects on children's health including lower birth weight, lower anogenital distance, lower Apgar scores, lower current weight, lower lung function, lower hepatitis B surface antibody levels, higher prevalence of attention-deficit/hyperactivity disorder, and higher DNA and chromosome damage. Heavy metals influence a number of diverse systems and organs, resulting in both acute and chronic effects on children's health, ranging from minor upper respiratory irritation to chronic respiratory, cardiovascular, nervous, urinary and reproductive disease, as well as aggravation of pre-existing symptoms and disease. These effects of heavy metals on children's health are briefly discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Calcination/dissolution testing for Hanford Site tank wastes

    International Nuclear Information System (INIS)

    Colby, S.A.; Delegard, C.H.; McLaughlin, D.F.; Danielson, M.J.

    1994-07-01

    Thermal treatment by calcination offers several benefits for the treatment of Hanford Site tank wastes, including the destruction of organics and ferrocyanides and an hydroxide fusion that permits the bulk of the mostly soluble nonradioactive constituents to be easily separated from the insoluble transuranic residue. Critical design parameters were tested, including: (1) calciner equipment design, (2) hydroxide fusion chemistry, and (3) equipment corrosion. A 2 gal/minute pilot plant processed a simulated Tank 101-SY waste and produced a free flowing 700 C molten calcine with an average calciner retention time of 20 minutes and >95% organic, nitrate, and nitrite destruction. Laboratory experiments using actual radioactive tank waste and the simulated waste pilot experiments indicate that 98 wt% of the calcine produced is soluble in water, leaving an insoluble transuranic fraction. All of the Hanford Site tank wastes can benefit from calcination/dissolution processing, contingent upon blending various tank waste types to ensure a target of 70 wt% sodium hydroxide/nitrate/nitrite fluxing agent. Finally, corrosion testing indicates that a jacketed nickel liner cooled to below 400 C would corrode <2 mil/year (0.05 mm/year) from molten calcine attack

  15. Lauryl Amine as heavy metal collector of boiler ash from pulp and paper mill waste

    Science.gov (United States)

    Sembiring, M. P.; Kaban, J.; Bangun, N.; Saputra, E.

    2018-04-01

    Theincreasing of demand of pulp and paper products, will following with the growing the pulp and paper industryand generate significant mill waste. The total waste reached 1/3 of the amount raw materials used and ash boiler is the waste with the largest percentage of 52%. For that it takes effort to manage the existing waste. The boiler ash contained the chemical elements, it can be utilized such as fertilizer, because it also contains transition metals in form of heavy metal such as Cadmium (Cd), Cobalt (Co), Chrome (Cr), Cupprum (Cu), Ferrum (Fe), Nickel (Ni), and Zinc (Zn), the use of boiler ash must follow the threshold specified by the Government. Several studies have been undertaken to reduce and extract heavy metals from ash and sand of the boiler by using carbon dioxide as its ligand. Eelectrochemical method was used to remove and recovery of heavy metals from the incenerator. This study focused on removal of heavy metals using Lauryl Amine as collector and three solvents namely Dichloromethane, Ethanol and n-Hexane. The treatmentswas able to extract the heavy metal and generally reduce the heavy metal content of ash boiler pulp and paper mill waste. The combination treatment used toreduce the heavy metal content of 5 gram Lauryl Amine collector in Dichloromethane solvent for 4 hours process time.

  16. An assessment on the recycling opportunities of wastes emanating from scrap metal processing in Mauritius

    Energy Technology Data Exchange (ETDEWEB)

    Mauthoor, Sumayya, E-mail: sumayya.mauthoor@umail.uom.ac.mu [Department of Chemical and Environmental Engineering, University of Mauritius, Réduit (Mauritius); Mohee, Romeela [Professor of Chemical and Environmental Engineering, National Research Chair in Solid Waste Management, Mauritius Research Council (Mauritius); Kowlesser, Prakash [Solid Waste/Beach Management Unit, Ministry of Local Government and Outer Islands (Mauritius)

    2014-10-15

    Highlights: • Scrap metal processing wastes. • Areas of applications for slag, electric arc furnace dust, mill scale and wastewater sludge. • Waste generation factor of 349.3 kg per ton of steel produced. • Waste management model. - Abstract: This paper presents an assessment on the wastes namely slag, dust, mill scale and sludge resulting from scrap metal processing. The aim of this study is to demonstrate that there are various ways via which scrap metal processing wastes can be reused or recycled in other applications instead of simply diverting them to the landfill. These wastes are briefly described and an overview on the different areas of applications is presented. Based on the results obtained, the waste generation factor developed was 349.3 kg per ton of steel produced and it was reported that slag represents 72% of the total wastes emanating from the iron and steel industry in Mauritius. Finally the suitability of the different treatment and valorisation options in the context of Mauritius is examined.

  17. Leaching characteristics of the metal waste form from the electrometallurgical treatment process: Product consistency testing

    International Nuclear Information System (INIS)

    Johnson, S. G.; Keiser, D. D.; Frank, S. M.; DiSanto, T.; Noy, M.

    1999-01-01

    Argonne National Laboratory is developing an electrometallurgical treatment for spent fuel from the experimental breeder reactor II. A product of this treatment process is a metal waste form that incorporates the stainless steel cladding hulls, zirconium from the fuel and the fission products that are noble to the process, i.e., Tc, Ru, Nb, Pd, Rh, Ag. The nominal composition of this waste form is stainless steel/15 wt% zirconium/1--4 wt% noble metal fission products/1--2 wt % U. Leaching results are presented from several tests and sample types: (1) 2 week monolithic immersion tests on actual metal waste forms produced from irradiated cladding hulls, (2) long term (>2 years) pulsed flow tests on samples containing technetium and uranium and (3) crushed sample immersion tests on cold simulated metal waste form samples. The test results will be compared and their relevance for waste form product consistency testing discussed

  18. System for processing ion exchange resin regeneration waste liquid in atomic power plant

    International Nuclear Information System (INIS)

    Onaka, Noriyuki; Tanno, Kazuo; Shoji, Saburo.

    1976-01-01

    Object: To reduce the quantity of radioactive waste to be solidified by recovering and repeatedly using sulfuric acid and sodium hydroxide which constitute the ion exchange resin regeneration waste liquid. Structure: Cation exchange resin regeneration waste liquid is supplied to an anion exchange film electrolytic dialyzer for recovering sulfuric acid through separation from impurity cations, while at the same time anion exchange resin regeneration waste liquid is supplied to a cation exchange film electrolytic dialyzer for recovering sodium hydroxide through separation from impurity anions. The sulfuric acid and sodium hydroxide thus recovered are condensed by a thermal condenser and then, after density adjustment, repeatedly used for the regeneration of the ion exchange resin. (Aizawa, K.)

  19. Metal waste forms from the electrometallurgical treatment of spent nuclear fuel

    International Nuclear Information System (INIS)

    Abraham, D.P.; McDeavitt, S.M.; Park, J.

    1996-01-01

    Stainless steel-zirconium alloys are being developed for the disposal of radioactive metal isotopes isolated using an electrometallurgical treatment technique to treat spent nuclear fuel. The nominal waste forms are stainless steel-15 wt% zirconium alloy and zirconium-8 wt% stainless steel alloy. These alloys are generated in yttria crucibles by melting the starting materials at 1,600 C under an argon atmosphere. This paper discusses the microstructures, corrosion and mechanical test results, and thermophysical properties of the metal waste form alloys

  20. Structure of bayerite-based lithium-aluminum layered double hydroxides (LDHs): observation of monoclinic symmetry.

    Science.gov (United States)

    Britto, Sylvia; Kamath, P Vishnu

    2009-12-21

    The double hydroxides of Li with Al, obtained by the imbibition of Li salts into bayerite and gibbsite-Al(OH)(3), are not different polytypes of the same symmetry but actually crystallize in two different symmetries. The bayerite-derived double hydroxides crystallize with monoclinic symmetry, while the gibbsite-derived hydroxides crystallize with hexagonal symmetry. Successive metal hydroxide layers in the bayerite-derived LDHs are translated by the vector ( approximately -1/3, 0, 1) with respect to each other. The exigency of hydrogen bonding drives the intercalated Cl(-) ion to a site with 2-fold coordination, whereas the intercalated water occupies a site with 6-fold coordination having a pseudotrigonal prismatic symmetry. The nonideal nature of the interlayer sites has implications for the observed selectivity of Li-Al LDHs toward anions of different symmetries.

  1. Novel recycle technology for recovering rare metals (Ga, In) from waste light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Zhan, Lu; Xia, Fafa; Ye, Qiuyu; Xiang, Xishu; Xie, Bing, E-mail: bxie@des.ecnu.edu.cn

    2015-12-15

    Highlights: • Rare metals (Ga, In) are separated and recycled from waste light-emitting diodes. • Pyrolysis, physical disaggregation and vacuum metallurgy separation are proposed. • There is no hazardous materials produced in this process. - Abstract: This work develops a novel process of recycling rare metals (Ga, In) from waste light-emitting diodes using the combination of pyrolysis, physical disaggregation methods and vacuum metallurgy separation. Firstly, the pure chips containing InGaN/GaN are adopted to study the vacuum separation behavior of rare metals, which aims to provide the theoretical foundation for recycling gallium and indium from waste light-emitting diodes. In order to extract the rare-metal-rich particles from waste light-emitting diodes, pyrolysis and physical disaggregation methods (crushing, screening, grinding and secondly screening) are studied respectively, and the operating parameters are optimized. With low boiling points and high saturation vapor pressures under vacuum, gallium and indium are separated from rare-metal-rich particles by the process of evaporation and condensation. By reference to the separating parameters of pure chips, gallium and indium in waste light-emitting diodes are recycled with the recovery efficiencies of 93.48% and 95.67% under the conditions as follows: heating temperature of 1373 K, vacuum pressure of 0.01–0.1 Pa, and holding time of 60 min. There are no secondary hazardous materials generated in the whole processes. This work provides an efficient and environmentally friendly process for recycling rare metals from waste light-emitting diodes.

  2. Separating and recycling metals from mixed metallic particles of crushed electronic wastes by vacuum metallurgy.

    Science.gov (United States)

    Zhan, Lu; Xu, Zhenming

    2009-09-15

    During the treatment of electronic wastes, a crushing process is usually used to strip metals from various base plates. Several methods have been applied to separate metals from nonmetals. However, mixed metallic particles obtained from these processes are still a mixture of various metals, including some toxic heavy metals such as lead and cadmium. With emphasis on recovering copper and other precious metals, there have hitherto been no satisfactory methods to recover these toxic metals. In this paper, the criterion of separating metals from mixed metallic particles by vacuum metallurgy is built. The results show that the metals with high vapor pressure have been almost recovered completely, leading to a considerable reduction of environmental pollution. In addition, the purity of copper in mixed particles has been improved from about 80 wt % to over 98 wt %.

  3. Implication of heavy metals distribution for a municipal solid waste management system - a case study in Shanghai

    International Nuclear Information System (INIS)

    Zhang Hua; He Pinjing; Shao Liming

    2008-01-01

    Heavy metal contamination in municipal solid waste (MSW) is of increasing concern. The occurrence and distribution of heavy metals in MSW and their implications for the integrated MSW management system in mega-cities have been investigated by means of material flow analysis based on a case study of Shanghai in China. A good statistical basis was provided through a one-year monitoring program on the mass and metals composition of the waste from three MSW treatment facilities. The results showed that the main heavy metals in the MSW were Zn, Cr, Cu, and Pb (on average > 100 mg kg -1 ), followed by Ni, Cd, and Hg. The MSW contained higher levels of Cu and Ni in metals, Cr and Pb in plastics, and Pb and Zn in the inorganic fractions. Regardless of the sources, the statistically similar heavy metal contents in the organic fractions indicated that effective blending and diffusion of heavy metals had taken place throughout the MSW collection, transfer, transportation, and storage, leading to cross-contamination of the waste fractions. PU (composed of putrescible waste and miscellaneous indistinguishable particles) contributed the majority of the heavy metals to the MSW, followed by plastics, as a result of the predominance in the overall composition of PU and plastics rather than from differences in their heavy metal contents. Therefore, manual or mechanical separation of some significantly heavy metal-rich fractions alone is not sufficient to reduce the heavy metal contents in the MSW. Source separation of organic waste and the diversion of tailored inorganic waste such as hazardous components, construction and demolition waste, etc., are proposed to control the heavy metal contamination in MSW. For the mixed MSW management system, physicochemical fractionation to exclude particles containing high levels of heavy metals can be conducted

  4. Implication of heavy metals distribution for a municipal solid waste management system - a case study in Shanghai

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Hua [State Key Laboratory of Pollution Control and Resources Reuse, Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092 (China); He Pinjing [State Key Laboratory of Pollution Control and Resources Reuse, Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092 (China)], E-mail: solidwaste@mail.tongji.edu.cn; Shao Liming [State Key Laboratory of Pollution Control and Resources Reuse, Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092 (China)

    2008-09-01

    Heavy metal contamination in municipal solid waste (MSW) is of increasing concern. The occurrence and distribution of heavy metals in MSW and their implications for the integrated MSW management system in mega-cities have been investigated by means of material flow analysis based on a case study of Shanghai in China. A good statistical basis was provided through a one-year monitoring program on the mass and metals composition of the waste from three MSW treatment facilities. The results showed that the main heavy metals in the MSW were Zn, Cr, Cu, and Pb (on average > 100 mg kg{sup -1}), followed by Ni, Cd, and Hg. The MSW contained higher levels of Cu and Ni in metals, Cr and Pb in plastics, and Pb and Zn in the inorganic fractions. Regardless of the sources, the statistically similar heavy metal contents in the organic fractions indicated that effective blending and diffusion of heavy metals had taken place throughout the MSW collection, transfer, transportation, and storage, leading to cross-contamination of the waste fractions. PU (composed of putrescible waste and miscellaneous indistinguishable particles) contributed the majority of the heavy metals to the MSW, followed by plastics, as a result of the predominance in the overall composition of PU and plastics rather than from differences in their heavy metal contents. Therefore, manual or mechanical separation of some significantly heavy metal-rich fractions alone is not sufficient to reduce the heavy metal contents in the MSW. Source separation of organic waste and the diversion of tailored inorganic waste such as hazardous components, construction and demolition waste, etc., are proposed to control the heavy metal contamination in MSW. For the mixed MSW management system, physicochemical fractionation to exclude particles containing high levels of heavy metals can be conducted.

  5. Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Sc, Ti, V, Cu and Zn

    International Nuclear Information System (INIS)

    Biesinger, Mark C.; Lau, Leo W.M.; Gerson, Andrea R.; Smart, Roger St.C.

    2010-01-01

    Chemical state X-ray photoelectron spectroscopic analysis of first row transition metals and their oxides and hydroxides is challenging due to the complexity of the 2p spectra resulting from peak asymmetries, complex multiplet splitting, shake-up and plasmon loss structure, and uncertain, overlapping binding energies. A review of current literature shows that all values necessary for reproducible, quantitative chemical state analysis are usually not provided. This paper reports a more consistent, practical and effective approach to curve-fitting the various chemical states in a variety of Sc, Ti, V, Cu and Zn metals, oxides and hydroxides. The curve-fitting procedures proposed are based on a combination of (1) standard spectra from quality reference samples, (2) a survey of appropriate literature databases and/or a compilation of the literature references, and (3) specific literature references where fitting procedures are available. Binding energies, full-width at half maximum (FWHM) values, spin-orbit splitting values, asymmetric peak-shape fitting parameters, and, for Cu and Zn, Auger parameters values are presented. The quantification procedure for Cu species details the use of the shake-up satellites for Cu(II)-containing compounds and the exact binding energies of the Cu(0) and Cu(I) peaks. The use of the modified Auger parameter for Cu and Zn species allows for corroborating evidence when there is uncertainty in the binding energy assignment. These procedures can remove uncertainties in analysis of surface states in nano-particles, corrosion, catalysis and surface-engineered materials.

  6. Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Sc, Ti, V, Cu and Zn

    Energy Technology Data Exchange (ETDEWEB)

    Biesinger, Mark C., E-mail: biesingr@uwo.ca [Surface Science Western, University of Western Ontario, University of Western Ontario Research Park, Room LL31, 999 Collip Circle, London, Ontario, N6G 0J3 (Canada); ACeSSS (Applied Centre for Structural and Synchrotron Studies), University of South Australia, Mawson Lakes, SA 5095 (Australia); Lau, Leo W.M. [Surface Science Western, University of Western Ontario, University of Western Ontario Research Park, Room LL31, 999 Collip Circle, London, Ontario, N6G 0J3 (Canada); Department of Chemistry, University of Western Ontario, London, Ontario, N6A 5B7 (Canada); Gerson, Andrea R.; Smart, Roger St.C. [ACeSSS (Applied Centre for Structural and Synchrotron Studies), University of South Australia, Mawson Lakes, SA 5095 (Australia)

    2010-11-15

    Chemical state X-ray photoelectron spectroscopic analysis of first row transition metals and their oxides and hydroxides is challenging due to the complexity of the 2p spectra resulting from peak asymmetries, complex multiplet splitting, shake-up and plasmon loss structure, and uncertain, overlapping binding energies. A review of current literature shows that all values necessary for reproducible, quantitative chemical state analysis are usually not provided. This paper reports a more consistent, practical and effective approach to curve-fitting the various chemical states in a variety of Sc, Ti, V, Cu and Zn metals, oxides and hydroxides. The curve-fitting procedures proposed are based on a combination of (1) standard spectra from quality reference samples, (2) a survey of appropriate literature databases and/or a compilation of the literature references, and (3) specific literature references where fitting procedures are available. Binding energies, full-width at half maximum (FWHM) values, spin-orbit splitting values, asymmetric peak-shape fitting parameters, and, for Cu and Zn, Auger parameters values are presented. The quantification procedure for Cu species details the use of the shake-up satellites for Cu(II)-containing compounds and the exact binding energies of the Cu(0) and Cu(I) peaks. The use of the modified Auger parameter for Cu and Zn species allows for corroborating evidence when there is uncertainty in the binding energy assignment. These procedures can remove uncertainties in analysis of surface states in nano-particles, corrosion, catalysis and surface-engineered materials.

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

    Science.gov (United States)

    Ahammed, M Mansoor; Meera, V

    2010-09-15

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

  8. Direct conversion of radioactive and chemical waste containing metals, ceramics, amorphous solids, and organics to glass

    International Nuclear Information System (INIS)

    Forsberg, C.W.; Beahm, E.C.; Parker, G.W.

    1994-01-01

    The Glass Material Oxidation and Dissolution System (CMODS) is a new process for direct conversion of radioactive, mixed, and chemical wastes to glass. The wastes can be in the chemical forms of metals, ceramics, amorphous solids, and organics. GMODS destroys organics and it incorporates heavy metals and radionuclides into a glass. Processable wastes may include miscellaneous spent fuels (SF), SF hulls and hardware, plutonium wastes in different forms, high-efficiency particulate air (HEPA) filters, ion-exchange resins, failed equipment, and laboratory wastes. Thermodynamic calculations indicate theoretical feasibility. Small-scale laboratory experiments (< 100 g per test) have demonstrated chemical laboratory feasibility for several metals. Additional work is needed to demonstrate engineering feasibility

  9. Method of processing radioactive wastes

    International Nuclear Information System (INIS)

    Takahashi, Toshihiko; Maruko, Morihisa; Takamura, Yoshiyuki.

    1981-01-01

    Purpose: To effectively separate radioactive claddings from the slurry of wasted ion exchange resins containing radioactive claddings. Method: Wasted ion exchange resins having radioactive claddings (fine particles of iron oxides or hydroxide adhered with radioactive cobalt) are introduced into a clad separation tank. Sulfuric acid or sodium hydroxide is introduced to the separation tank to adjust the pH value to 3 - 6. Then, sodium lauryl sulfate is added for capturing claddings and airs are blown from an air supply nozzle to generate air bubbles. The claddings are detached from the ion exchange resins and adhered to the air bubbles. The air bubbles adhered with the claddings float up to the surface of the liquid wastes and then forced out of the separation tank. (Ikeda, J.)

  10. Method of solidifying radioactive wastes

    International Nuclear Information System (INIS)

    Tomita, Toshihide; Minami, Yuji; Matsuura, Hiroyuki

    1984-01-01

    Purpose: To enable complete curing even when radioactive wastes contain those materials hindering the curing reaction, for example, copper hydroxide. Method: After admixing an alkaline substance to radioactive concentrated liquid wastes containing copper hydroxide or other amphoteric substances, they are dried, powderized and then cured with thermosetting resins. The thermosetting resins usable herein include, for example, those prepared by mixing an unsaturated polyester with a monomer such as styrene. When a polymerization initiator such as methyl ethyl ketone peroxide and a polymerization promotor are added to the mixture, it takes places curing reaction at normal temperature. Suitable alkaline substances usable herein are those which are insoluble to the liquid wastes and do not change the chemical form under heating and drying. (Yoshihara, H.)

  11. Chemical species of plutonium in Hanford radioactive tank waste

    International Nuclear Information System (INIS)

    Barney, G.S.

    1997-01-01

    Large quantities of radioactive wastes have been generated at the Hanford Site over its operating life. The wastes with the highest activities are stored underground in 177 large (mostly one million gallon volume) concrete tanks with steel liners. The wastes contain processing chemicals, cladding chemicals, fission products, and actinides that were neutralized to a basic pH before addition to the tanks to prevent corrosion of the steel liners. Because the mission of the Hanford Site was to provide plutonium for defense purposes, the amount of plutonium lost to the wastes was relatively small. The best estimate of the amount of plutonium lost to all the waste tanks is about 500 kg. Given uncertainties in the measurements, some estimates are as high as 1,000 kg (Roetman et al. 1994). The wastes generally consist of (1) a sludge layer generated by precipitation of dissolved metals from aqueous wastes solutions during neutralization with sodium hydroxide, (2) a salt cake layer formed by crystallization of salts after evaporation of the supernate solution, and (3) an aqueous supernate solution that exists as a separate layer or as liquid contained in cavities between sludge or salt cake particles. The identity of chemical species of plutonium in these wastes will allow a better understanding of the behavior of the plutonium during storage in tanks, retrieval of the wastes, and processing of the wastes. Plutonium chemistry in the wastes is important to criticality and environmental concerns, and in processing the wastes for final disposal. Plutonium has been found to exist mainly in the sludge layers of the tanks along with other precipitated metal hydrous oxides. This is expected due to its low solubility in basic aqueous solutions. Tank supernate solutions do not contain high concentrations of plutonium even though some tanks contain high concentrations of complexing agents. The solutions also contain significant concentrations of hydroxide which competes with other

  12. Lime treatment of liquid waste containing heavy metals, radionuclides and organics

    International Nuclear Information System (INIS)

    DuPont, A.

    1990-01-01

    This paper reports on lime treatment of liquid waste containing heavy metals, radio nuclides and organics. Lime is wellknown for its use in softening drinking water the treatment of municipal wastewaters. It is becoming important in the treatment of industrial wastewater and liquid inorganic hazardous waste; however, there are many questions regarding the use of lime for the treatment of liquid hazardous waste

  13. Mechanistic investigation of internal corrosion in nuclear waste containers over extended time periods

    International Nuclear Information System (INIS)

    Onumonu, E.; Stevens, D. N. P. C.

    2008-01-01

    Storage of the UK's Intermediate Level Wastes (ILW), which comprises Magnox fuel cladding, uranium and small items of equipment exposed to radiation, is currently achieved via encapsulation within cementitious grout housed in 500 litre 316L stainless steel drums. The cements used display a high pH; in such an environment many metals form surface hydroxides or oxides. Magnox reacts with free water at high pH with the liberation of hydrogen whilst undergoing corrosion to form hydroxide species. Corrosion of Magnox cladding has previously been monitored by measuring the rate of hydrogen evolution and/or weight loss. Recent work by our group has shown impedance techniques may also be useful in monitoring early corrosion behaviour. In this project electrochemical polarisation techniques will be employed to examine the corrosion behaviour of Magnox fuel in situations where it is in electrical contact with other metals, including uranium, and hence determine how galvanic effects influence corrosion behaviour. In this paper we describe the background to such experiments along with some preliminary results. (authors)

  14. Hanford Waste Physical and Rheological Properties: Data and Gaps

    Energy Technology Data Exchange (ETDEWEB)

    Wells, Beric E.; Kurath, Dean E.; Mahoney, Lenna A.; Onishi, Yasuo; Huckaby, James L.; Cooley, Scott K.; Burns, Carolyn A.; Buck, Edgar C.; Tingey, Joel M.; Daniel, Richard C.; Anderson, K. K.

    2011-08-01

    The Hanford Site in Washington State manages 177 underground storage tanks containing approximately 250,000 m3 of waste generated during past defense reprocessing and waste management operations. These tanks contain a mixture of sludge, saltcake and supernatant liquids. The insoluble sludge fraction of the waste consists of metal oxides and hydroxides and contains the bulk of many radionuclides such as the transuranic components and 90Sr. The saltcake, generated by extensive evaporation of aqueous solutions, consists primarily of dried sodium salts. The supernates consist of concentrated (5-15 M) aqueous solutions of sodium and potassium salts. The 177 storage tanks include 149 single-shell tanks (SSTs) and 28 double -hell tanks (DSTs). Ultimately the wastes need to be retrieved from the tanks for treatment and disposal. The SSTs contain minimal amounts of liquid wastes, and the Tank Operations Contractor is continuing a program of moving solid wastes from SSTs to interim storage in the DSTs. The Hanford DST system provides the staging location for waste feed delivery to the Department of Energy (DOE) Office of River Protection’s (ORP) Hanford Tank Waste Treatment and Immobilization Plant (WTP). The WTP is being designed and constructed to pretreat and then vitrify a large portion of the wastes in Hanford’s 177 underground waste storage tanks.

  15. Leaching of gold, silver and accompanying metals from circuit boards (PCBs waste

    Directory of Open Access Journals (Sweden)

    Jana Ficeriová

    2011-12-01

    Full Text Available Au-Ag noble metal wastes represent a wide range of waste types and forms, with various accompanying metallic elements.The presented leaching strategy for Au-Ag contained in circuit boards (PCBs aims at gaining gold and silver in the metallic form.Application of the proposed ammonium thiosulphate leaching process for the treatment of the above mentioned Au-Ag containing wastesrepresents a practical, economic and at the same time an ecological solution. The ammonium thiosulphate based leaching of gold and silverfrom PCBs waste, using crushing as a pretreatment, was investigated. It was possible to achieve 98 % gold and 93 % silver recovery within48 hours of ammonium thiosulphate leaching. This type of leaching is a better leaching procedure for recovery of gold and silver from PCBwaste than the classical toxic cyanide leaching. 84 % Cu, 82 % Fe, 77 % Al, 76 % Zn, 70 % Ni, 90 % Pd, 88 % Pb and 83 % Sn recovery ofthe accompanying metals was achieved, using sulphuric acid with hydrogen peroxide, sodium chloride and aqua regia. A four steps leachingprocess gave a very satisfactory yield and a more rapid kinetics for all observed metals solubilization than other technologies.

  16. Direct conversion of plutonium metal, scrap, residue, and transuranic waste to glass

    International Nuclear Information System (INIS)

    Forsberg, C.W.; Beahm, E.C.; Parker, G.W.; Malling, J.F.; Rudolph, J.

    1995-01-01

    A method for the direct conversion of metals, ceramics, organics, and amorphous solids to borosilicate glass has been invented. The process is called the Glass Material Oxidation and Dissolution System (GMODS). Traditional glass-making processes can convert only oxide materials to glass. However, many wastes contain complex mixtures of metals, ceramics, organics, and amorphous solids. Conversion of such mixtures to oxides followed by their conversion to glass is often impractical. GMODS may create a practical method to convert such mixtures to glass. Plutonium-containing materials (PCMS) exist in many forms, including metals, ceramics, organics, amorphous solids, and mixtures thereof. These PCMs vary from plutonium metal to filters made of metal, organic binders, and glass fibers. For storage and/or disposal of PCMS, it is desirable to convert PCMs to borosilicate glass. Borosilicate glass is the preferred repository waste form for high-level waste (HLW) because of its properties. PCMs converted to a transuranic borosilicate homogeneous glass would easily pass all waste acceptance and storage criteria. Conversion of PCMs to a glass would also simplify safeguards by conversion of heterogeneous PCMs to homogeneous glass. Thermodynamic calculations and proof-of-principle experiments on the GMODS process with cerium (plutonium surrogate), uranium, stainless steel, aluminum, Zircaloy-2, and carbon were successfully conducted. Initial analysis has identified potential flowsheets and equipment. Major unknowns remain, but the preliminary data suggests that GMODS may be a major new treatment option for PCMs

  17. Behavior of radioactive metal surrogates under various waste combustion conditions

    International Nuclear Information System (INIS)

    Yang, Hee Chul; Lee, Jae Hee; Kim, Jung Guk; Yoo, Jae Hyung; Kim, Joon Hyung

    2002-01-01

    A laboratory investigation of the behavior of radioactive metals under the various waste combustion atmospheres was conducted to predict the parameters that influence their partitioning behavior during waste incineration. Neodymium, samarium, cerium, gadolinium, cesium and cobalt were used as non-radioactive surrogate metals that are representative of uranium, plutonium, americium, curium, radioactive cesium, and radioactive cobalt, respectively. Except for cesium, all of the investigated surrogate metal compounds converted into each of their stable oxides at medium temperatures from 400 to 900 .deg. C, under oxygen-deficient and oxygen-sufficient atmospheres (0.001-atm and 0.21-atm O 2 ). At high temperatures above 1,400 .deg. C, cerium, neodymium and samarium in the form of their oxides started to vaporize but the vaporization rates were very slow up to 1500 .deg. C. Inorganic chlorine (NaCl) as well as organic chlorine (PVC) did not impact the volatility of investigated Nd 2 O 3 , CoO and Cs 2 O. The results of laboratory investigations suggested that the combustion chamber operating parameters affecting the entrainment of particulate and filtration equipment operating parameters affecting particle collection efficiency be the governing parameters of alpha radionuclides partitioning during waste incineration

  18. Obtaining low temperature catalysts for methanol synthesis by no-waste process

    Energy Technology Data Exchange (ETDEWEB)

    Il' ko, E G; Sushchaya, L E; Bondar' , P G

    1982-11-01

    Low temperature production of catalysts for methanol synthesis involves considerable pollution of the environment as well as formation of side products. The authors propose producing such catalysts from joint precipitates of copper and zinc carbonates includiing stabilizers produced by decomposing solvents, then drying, aging and shaping. This method avoids waste water usually formed in scrubbing to remove ions of alkaline metals. Aluminum hydroxide is suggested as a stabilizer. The catalyst tablets prepared in this way were found to have activity like those produced by other methods, and were suitable for industrial use.

  19. Heavy Metal Contamination of Soils around a Hospital Waste Incinerator Bottom Ash Dumps Site.

    Science.gov (United States)

    Adama, M; Esena, R; Fosu-Mensah, B; Yirenya-Tawiah, D

    2016-01-01

    Waste incineration is the main waste management strategy used in treating hospital waste in many developing countries. However, the release of dioxins, POPs, and heavy metals in fly and bottom ash poses environmental and public health concerns. To determine heavy metal (Hg, Pb, Cd, Cr, and Ag) in levels in incinerator bottom ash and soils 100 m around the incinerator bottom ash dump site, ash samples and surrounding soil samples were collected at 20 m, 40 m, 60 m, 80 m, 100 m, and 1,200 m from incinerator. These were analyzed using the absorption spectrophotometer method. The geoaccumulation (I geo) and pollution load indices (PLI) were used to assess the level of heavy metal contamination of surrounding soils. The study revealed high concentrations in mg/kg for, Zn (16417.69), Pb (143.80), Cr (99.30), and Cd (7.54) in bottom ash and these were above allowable limits for disposal in landfill. The study also found soils within 60 m radius of the incinerator to be polluted with the metals. It is recommended that health care waste managers be educated on the implication of improper management of incinerator bottom ash and regulators monitor hospital waste incinerator sites.

  20. Modeling the degradation of a metallic waste form intended for geologic disposal

    International Nuclear Information System (INIS)

    Bauer, T.H.; Morris, E.E.

    2007-01-01

    Nuclear reactors operating with metallic fuels have led to development of robust metallic waste forms intended to immobilize hazardous constituents in oxidizing environments. Release data from a wide range of tests where small waste form samples have been immersed in a variety of oxidizing solutions have been analyzed and fit to a mechanistically-derived 'logarithmic growth' form for waste form degradation. A bounding model is described which plausibly extrapolates these fits to long-term degradation in a geologic repository. The resulting empirically-fit degradation model includes dependence on solution pH, temperature, and chloride concentration as well as plausible estimates of statistical uncertainty. (authors)

  1. Estimation of Pb from metal and electroplating industrial waste by ...

    African Journals Online (AJOL)

    The concentration of lead in sediment and liquid waste samples of selected metal electroplating industries was measured by atomic absorption spectrophotometer. The data obtained revealed that lead content in liquid wastes varies in the range of 0.582-14.97 mg L-1 and 1.300-757.8 mg Kg-1 in sediments. Removal of ...

  2. Production of zeolite A come from rio Capim Kaolin: Study on recycle of sodium hydroxide solution

    International Nuclear Information System (INIS)

    Moraes, C.G.; Rodrigues, E.C.; Rocha Junior, C.A.F.; Macedo, E.N.; Neves, R.F.

    2011-01-01

    The kaolin processing industry is an important economic sector in the State of Para, but produces huge amounts of wastes composed essentially of kaolinite. The production processes of zeolites typically use sodium hydroxide in excess, are discarded. So the objective is the development process for production of zeolite A which allows the reuse of the solution of sodium hydroxide used in excess through your recycling. Presents the results of XRD, SEM of the zeolites produced in five consecutive cycles performed at a temperature of 110°C/24h as a source of sodium hydroxide solution of sodium 5 M, using a molar ratio of Si/Al = 1 and Na/Al = 1,26. (author)

  3. Pollution distribution of heavy metals in surface soil at an informal electronic-waste recycling site.

    Science.gov (United States)

    Fujimori, Takashi; Takigami, Hidetaka

    2014-02-01

    We studied distribution of heavy metals [lead (Pb), copper (Cu) and zinc (Zn)] in surface soil at an electronic-waste (e-waste) recycling workshop near Metro Manila in the Philippines to evaluate the pollution size (spot size, small area or the entire workshop), as well as to assess heavy metal transport into the surrounding soil environment. On-site length-of-stride-scale (~70 cm) measurements were performed at each surface soil point using field-portable X-ray fluorescence (FP-XRF). The surface soil at the e-waste recycling workshop was polluted with Cu, Zn and Pb, which were distributed discretely in surface soil. The site was divided into five areas based on the distance from an entrance gate (y-axis) of the e-waste recycling workshop. The three heavy metals showed similar concentration gradients in the y-axis direction. Zn, Pb and Cu concentrations were estimated to decrease to half of their maximum concentrations at ~3, 7 and 7 m from the pollution spot, respectively, inside the informal e-waste recycling workshop. Distance from an entrance may play an important role in heavy metal transport at the soil surface. Using on-site FP-XRF, we evaluated the metal ratio to characterise pollution features of the solid surface. Variability analysis of heavy metals revealed vanishing surficial autocorrelation over metre ranges. Also, the possibility of concentration prediction at unmeasured points using geostatistical kriging was evaluated, and heavy metals had a relative "small" pollution scales and remained inside the original workshop compared with toxic organohalogen compounds. Thus, exposure to heavy metals may directly influence the health of e-waste workers at the original site rather than the surrounding habitat and environmental media.

  4. Application of biotechnology in management of industrial wastes containing toxic metals

    Energy Technology Data Exchange (ETDEWEB)

    Barton, L L; Fekete, F A; Huybrechts, M M.E. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Biology; Sillerud, L O [Los Alamos National Lab., NM (United States); Blacke, II, R C [Meharry Medical Coll., Nashville, TN (United States); Pigg, C J [Sandia National Labs., Albuquerque, NM (United States)

    1994-01-01

    The role of microorganisms in transformation and absorption of metals in the environment is examined in this article. Understanding the metabolic processes by which microorganisms interact with toxic metals is paramount for any bioremediation process dealing with restoration of toxic waste site. Bacteria, fungi, and yeast that displayed resistance to lead, mercury, or chromium were isolated from the environment. Cotolerance studies revealed that many of these organisms could grow in high concentrations of several different toxic elements. Transformation of chromium, mercury, and lead was displayed by means of the isolated bacterial strains. Data regarding the activities of these organisms can provide a basis for use of metal/tolerant organisms in bioremediation of toxic wastes containing mercury, chromium, and lead. (author) 1 fig., 7 tabs., 28 refs.

  5. Reactions between rocks and the hydroxides of calcium, sodium and potassium: progress report no. 1

    International Nuclear Information System (INIS)

    Van Aardt, J.H.P.; Visser, S.

    1982-01-01

    The reaction between the hydroxides of calcium, sodium and potassium, and clay minerals, feldspars, and some rocks (aggregates for use in concrete) was investigated. The reaction products were examined by means of x-ray diffraction and chemical analysis. The solid reaction products identified were hydrated calcium silicates,hydrated calcium aluminates, and hydrated calcium alumina silicates. It was found that, in the presence of water, calcium hydroxide liberated alkali into solution if the rocks and minerals contained alkali metals in their structure. Two crystalline hydrated sodium calcium silicates (12A and 16A) were prepared in the system Na 2 O-CaO-SiO 2 -H 2 O at 80 degrees Celsius. The one compound (12A) was also observed when sodium hydroxide plus calcium hydroxide and water reacted with silica- or silicate-containing rocks

  6. Immobilization technologies for the management of hazardous industrial waste using granite waste (case study)

    Energy Technology Data Exchange (ETDEWEB)

    Lasheen, Mohamed R.; Ashmawy, Azza M.; Ibrahim, Hanan S.; Moniem, Shimaa M. Abdel [National Research Centre, Giza (Egypt)

    2016-03-15

    Full characterization of granite waste sludge (GWS) was accomplished by X-ray diffraction (XRD) and Xray fluorescence (XRF) for identification of its phase and chemical composition. Different leaching tests were conducted to determine the efficiency of the GWS for metal stabilization in hazardous sludge. The leaching of the metals from stabilized contaminated sludge was decreased as the GWS amount increased. Only 15% of GWS was sufficient for stabilization of all metal ions under investigation. The main reason for metal immobilization was attributed to the aluminosilicates or silicates matrix within the GWS, which can transform the metals in the form of their insoluble hydroxides or absorbed in the stabilized matrix. Also, solidification/stabilization technique was used for remediation of contaminated sludge. Compressive strength test after curing for 28 days was used for measuring the effectiveness of remediation technique; it was found to be 1.88MPa. This indicated that the remediated sludge was well solidified and safe to be used as a raw substance for roadway blocks. Therefore, this huge amount of by-product sludge derived from the granite cutting industry, which has a negative environmental impact due to its disposal, can be utilized as a binder material for solidification/stabilization of hazardous sludge.

  7. Low temperature incineration of mixed wastes using bulk metal oxide catalysts

    International Nuclear Information System (INIS)

    Gordon, M.J.; Gaur, S.; Kelkar, S.; Baldwin, R.M.

    1996-01-01

    Volume reduction of low-level mixed wastes from former nuclear weapons facilities is a significant environmental problem. Processing of these materials presents unique scientific and engineering problems due to the presence of minute quantities of radionuclides which must be contained and concentrated for later safe disposal. Low-temperature catalytic incineration is one option that has been utilized at the Rocky Flats facility for this purpose. This paper presents results of research regarding evaluation of bulk metal oxides as catalysts for low-temperature incineration of carbonaceous residues which are typical by-products of fluidized bed combustion of mixed wastes under oxygen-lean conditions. A series of 14 metal oxides were screened in a thermogravimetric analyzer, using on-line mass spectrometry for speciation of reaction product gases. Catalyst evaluation criteria focused on the thermal-redox activity of the metals using both carbon black and PVC char as surrogate waste materials. Results indicated that metal oxides which were P-type semiconductor materials were suitable as catalysts for this application. Oxides of cobalt, molybdenum, vanadium, and manganese were found to be particularly stable and active catalysts under conditions specific to this process (T<650C, low oxygen partial pressures). Bench-scale evaluation of these metal oxides with respect to stability to chlorine (HCl) attack was carried out at 550C using a TG/MS system. Cobalt oxide was found to be resistant to metal loss in a HCl/He gaseous environment while metal loss from Mo, Mn, and V-based catalysts was moderate to severe. XRD and SEM/EDX analysis of spent Co catalysts indicated the formation of non-stoichiometric cobalt chlorides. Regeneration of chlorinated cobalt was found to successfully restore the low-temperature combustion activity to that of the fresh metal oxide

  8. Informal e-waste recycling: environmental risk assessment of heavy metal contamination in Mandoli industrial area, Delhi, India.

    Science.gov (United States)

    Pradhan, Jatindra Kumar; Kumar, Sudhir

    2014-01-01

    Nowadays, e-waste is a major source of environmental problems and opportunities due to presence of hazardous elements and precious metals. This study was aimed to evaluate the pollution risk of heavy metal contamination by informal recycling of e-waste. Environmental risk assessment was determined using multivariate statistical analysis, index of geoaccumulation, enrichment factor, contamination factor, degree of contamination and pollution load index by analysing heavy metals in surface soils, plants and groundwater samples collected from and around informal recycling workshops in Mandoli industrial area, Delhi, India. Concentrations of heavy metals like As (17.08 mg/kg), Cd (1.29 mg/kg), Cu (115.50 mg/kg), Pb (2,645.31 mg/kg), Se (12.67 mg/kg) and Zn (776.84 mg/kg) were higher in surface soils of e-waste recycling areas compared to those in reference site. Level exceeded the values suggested by the US Environmental Protection Agency (EPA). High accumulations of heavy metals were also observed in the native plant samples (Cynodon dactylon) of e-waste recycling areas. The groundwater samples collected form recycling area had high heavy metal concentrations as compared to permissible limit of Indian Standards and maximum allowable limit of WHO guidelines for drinking water. Multivariate analysis and risk assessment studies based on total metal content explains the clear-cut differences among sampling sites and a strong evidence of heavy metal pollution because of informal recycling of e-waste. This study put forward that prolonged informal recycling of e-waste may accumulate high concentration of heavy metals in surface soils, plants and groundwater, which will be a matter of concern for both environmental and occupational hazards. This warrants an immediate need of remedial measures to reduce the heavy metal contamination of e-waste recycling sites.

  9. Calcium hydroxide poisoning

    Science.gov (United States)

    Hydrate - calcium; Lime milk; Slaked lime ... Calcium hydroxide ... These products contain calcium hydroxide: Cement Limewater Many industrial solvents and cleaners (hundreds to thousands of construction products, flooring strippers, brick cleaners, cement ...

  10. Application of nanodimensional particles and aluminum hydroxide nanostructures for cancer diagnosis and therapy

    Science.gov (United States)

    Korovin, M. S.; Fomenko, A. N.

    2017-09-01

    Nanoparticles and nanostructured materials are one of the most promising developments for cancer therapy. Gold nanoparticles, magnetic nanoparticles based on iron and its oxides and other metal oxides have been widely used in diagnosis and treatment of cancer. Much less researchers' attention has been paid to nanoparticles and nanostructures based on aluminum oxides and hydroxides as materials for cancer diagnosis and treatment. However, recent investigations have shown promising results regarding these objects. Here, we review the antitumor results obtained with different aluminum oxide/hydroxide nanoparticles and nanostructures.

  11. The corrosion properties of Zr-Cr-NM alloy metallic waste form for longterm disposal

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seung Youb; Jang, Seon Ah; Eun, Hee Chul; Choi, Jung Hoon; Lee, Ki Rak; Park, Hwan Seo; Ahn, Do Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-06-15

    KAERI is conducting research on spent cladding hulls and additive metals to generate a solidifcation host matrix for the noble metal fssion product waste in anode sludge from the electro-refning process to minimize the volume of waste that needs to be disposed of. In this study, alloy compositions Zr-17Cr, Zr-22Cr, and Zr-27Cr were prepared with or without eight noble metals representing fuel waste using induction melting. The microstructures of the resulting alloys were characterized and electrochemical corrosion tests were conducted to evaluate their corrosion characteristics. All the compositions had better corrosion characteristics than other Zr-based alloys that were evaluated for comparison. Analysis of the leach solution after the corrosion test of the Zr-22Cr-8NM specimen indicated that the noble metals were not leached during corrosion under 500 mV imposed voltage, which simulates a highly oxidizing disposal environment. The results of this study confrm that Zr-Cr based compositions will likely serve as chemically stable waste forms.

  12. Treatment of complex electroplating waste by 'zero discharge' technique

    International Nuclear Information System (INIS)

    Khattak, B.Q.; Ram Sankar, P.; Jain, A.K.

    2009-01-01

    Surface treatment processes generate lot of liquid waste, which contains toxic substances and are potentially harmful to the living beings. It is extremely difficult to treat the pollutants where processes and frequencies are not fixed. In Chemical Treatment Facility of RRCAT, surface treatment processes are user dependent and makes the electroplating waste very complicated. Initially the waste was treated by simple chemical transformation technique in which heavy metal ions are converted to hydroxide precipitates. Non metallic ions that contribute much to the plating waste could not be treated by this process. To remove maximum possible pollutants, many experiments were conducted on the laboratory scale. Based on those results, a pilot ion exchange plant of various resins was introduced in the process to achieve disposal quality effluent. Anionic load of Phosphate, Nitrate and fluoride caused frequent anionic bed exhaustions and polymeric network damaging. To avoid this phenomenon a new setup was designed. This pre treatment has the capacity to treat 500 litres per hour connected to a platter with clarifier followed by high pressure carbon and pebbles filters. Analysis of these ions was carried out on the advanced ion chromatography system and is found free of toxic metals, phosphate and fluoride. This effluent can be reused by adding a reverse osmosis system followed by ion exchange system to produce good quality de mineralized water needed for surface treatment activities. In this paper we describe the existing status of effluent treatment facility and future plans for achieving 'zero discharge'. (author)

  13. Development of Simulants to Support Mixing Tests for High Level Waste and Low Activity Waste

    International Nuclear Information System (INIS)

    EIBLING, RUSSELLE.

    2004-01-01

    The objectives of this study were to develop two different types of simulants to support vendor agitator design studies and mixing studies. The initial simulant development task was to develop rheologically-bounding physical simulants and the final portion was to develop a nominal chemical simulant which is designed to match, as closely as possible, the actual sludge from a tank. The physical simulants to be developed included a lower and upper rheologically bounded: pretreated low activity waste (LAW) physical simulant; LAW melter feed physical simulant; pretreated high level waste (HLW) physical simulant; HLW melter feed physical simulant. The nominal chemical simulant, hereafter referred to as the HLW Precipitated Hydroxide simulant, is designed to represent the chemical/physical composition of the actual washed and leached sludge sample. The objective was to produce a simulant which matches not only the chemical composition but also the physical properties of the actual waste sample. The HLW Precipitated Hydroxide simulant could then be used for mixing tests to validate mixing, homogeneity and representative sampling and transferring issues. The HLW Precipitated Hydroxide simulant may also be used for integrated nonradioactive testing of the WTP prior to radioactive operation

  14. Mitigation of Hydrogen Gas Generation from the Reaction of Uranium Metal with Water in K Basin Sludge and Sludge Waste Forms

    Energy Technology Data Exchange (ETDEWEB)

    Sinkov, Sergey I.; Delegard, Calvin H.; Schmidt, Andrew J.

    2011-06-08

    Prior laboratory testing identified sodium nitrate and nitrite to be the most promising agents to minimize hydrogen generation from uranium metal aqueous corrosion in Hanford Site K Basin sludge. Of the two, nitrate was determined to be better because of higher chemical capacity, lower toxicity, more reliable efficacy, and fewer side reactions than nitrite. The present lab tests were run to determine if nitrate’s beneficial effects to lower H2 generation in simulated and genuine sludge continued for simulated sludge mixed with agents to immobilize water to help meet the Waste Isolation Pilot Plant (WIPP) waste acceptance drainable liquid criterion. Tests were run at ~60°C, 80°C, and 95°C using near spherical high-purity uranium metal beads and simulated sludge to emulate uranium-rich KW containerized sludge currently residing in engineered containers KW-210 and KW-220. Immobilization agents tested were Portland cement (PC), a commercial blend of PC with sepiolite clay (Aquaset II H), granulated sepiolite clay (Aquaset II G), and sepiolite clay powder (Aquaset II). In all cases except tests with Aquaset II G, the simulated sludge was mixed intimately with the immobilization agent before testing commenced. For the granulated Aquaset II G clay was added to the top of the settled sludge/solution mixture according to manufacturer application directions. The gas volumes and compositions, uranium metal corrosion mass losses, and nitrite, ammonia, and hydroxide concentrations in the interstitial solutions were measured. Uranium metal corrosion rates were compared with rates forecast from the known uranium metal anoxic water corrosion rate law. The ratios of the forecast to the observed rates were calculated to find the corrosion rate attenuation factors. Hydrogen quantities also were measured and compared with quantities expected based on non-attenuated H2 generation at the full forecast anoxic corrosion rate to arrive at H2 attenuation factors. The uranium metal

  15. Mitigation of Hydrogen Gas Generation from the Reaction of Uranium Metal with Water in K Basin Sludge and Sludge Waste Forms

    International Nuclear Information System (INIS)

    Sinkov, Sergey I.; Delegard, Calvin H.; Schmidt, Andrew J.

    2011-01-01

    Prior laboratory testing identified sodium nitrate and nitrite to be the most promising agents to minimize hydrogen generation from uranium metal aqueous corrosion in Hanford Site K Basin sludge. Of the two, nitrate was determined to be better because of higher chemical capacity, lower toxicity, more reliable efficacy, and fewer side reactions than nitrite. The present lab tests were run to determine if nitrate's beneficial effects to lower H2 generation in simulated and genuine sludge continued for simulated sludge mixed with agents to immobilize water to help meet the Waste Isolation Pilot Plant (WIPP) waste acceptance drainable liquid criterion. Tests were run at ∼60 C, 80 C, and 95 C using near spherical high-purity uranium metal beads and simulated sludge to emulate uranium-rich KW containerized sludge currently residing in engineered containers KW-210 and KW-220. Immobilization agents tested were Portland cement (PC), a commercial blend of PC with sepiolite clay (Aquaset II H), granulated sepiolite clay (Aquaset II G), and sepiolite clay powder (Aquaset II). In all cases except tests with Aquaset II G, the simulated sludge was mixed intimately with the immobilization agent before testing commenced. For the granulated Aquaset II G clay was added to the top of the settled sludge/solution mixture according to manufacturer application directions. The gas volumes and compositions, uranium metal corrosion mass losses, and nitrite, ammonia, and hydroxide concentrations in the interstitial solutions were measured. Uranium metal corrosion rates were compared with rates forecast from the known uranium metal anoxic water corrosion rate law. The ratios of the forecast to the observed rates were calculated to find the corrosion rate attenuation factors. Hydrogen quantities also were measured and compared with quantities expected based on non-attenuated H2 generation at the full forecast anoxic corrosion rate to arrive at H2 attenuation factors. The uranium metal

  16. Informal E-waste recycling in developing countries: review of metal(loid)s pollution, environmental impacts and transport pathways.

    Science.gov (United States)

    Ackah, Michael

    2017-11-01

    Crude or primitive recycling practices are often adopted in material resource recovery from E-waste in developing nations. Significant human health and environmental impacts may occur because of such practices. Literature on metal(loid)s pollution during E-waste processing is fragmented. Here, I review the health and environmental impacts of E-waste recycling operations and transport pathways of metal(loid)s, dispersed during operations. This paper is organised into five sections. Section 1 relates to the background of global E-waste generation and legal/illegal trade, citing specific cases from Ghana and other developing nations. Section 2 provides a brief information on sources of metal(loid)s in E-waste. Section 3 describes characteristics of informal E-waste recycling operations in developing nations. Section 4 examines the health and environmental impacts in E-waste recycling while section 5 evaluates major transport pathways of metal(loid)s contaminants.

  17. Sodium hydroxide poisoning

    Science.gov (United States)

    Sodium hydroxide is a very strong chemical. It is also known as lye and caustic soda. This ... poisoning from touching, breathing in (inhaling), or swallowing sodium hydroxide. This article is for information only. Do ...

  18. Insights into metals in individual fine particles from municipal solid waste using synchrotron radiation-based micro-analytical techniques.

    Science.gov (United States)

    Zhu, Yumin; Zhang, Hua; Shao, Liming; He, Pinjing

    2015-01-01

    Excessive inter-contamination with heavy metals hampers the application of biological treatment products derived from mixed or mechanically-sorted municipal solid waste (MSW). In this study, we investigated fine particles of heavy metal content, using bulk detection techniques. A total of 17 individual fine particles were evaluated using synchrotron radiation-based micro-X-ray fluorescence and micro-X-ray diffraction. We also discussed the association, speciation and source apportionment of heavy metals. Metals were found to exist in a diffuse distribution with heterogeneous intensities and intense hot-spots of metals revealed the potential sources of fine particles from size-reduced waste fractions (such as scraps of organic wastes or ceramics) or from the importation of other particles. The diverse sources of heavy metal pollutants within the fine particles suggested that separate collection and treatment of the biodegradable waste fraction (such as food waste) is a preferable means of facilitating the beneficial utilization of the stabilized products. Copyright © 2014. Published by Elsevier B.V.

  19. Heavy Metal Contamination of Soils around a Hospital Waste Incinerator Bottom Ash Dumps Site

    Directory of Open Access Journals (Sweden)

    M. Adama

    2016-01-01

    Full Text Available Waste incineration is the main waste management strategy used in treating hospital waste in many developing countries. However, the release of dioxins, POPs, and heavy metals in fly and bottom ash poses environmental and public health concerns. To determine heavy metal (Hg, Pb, Cd, Cr, and Ag in levels in incinerator bottom ash and soils 100 m around the incinerator bottom ash dump site, ash samples and surrounding soil samples were collected at 20 m, 40 m, 60 m, 80 m, 100 m, and 1,200 m from incinerator. These were analyzed using the absorption spectrophotometer method. The geoaccumulation (Igeo and pollution load indices (PLI were used to assess the level of heavy metal contamination of surrounding soils. The study revealed high concentrations in mg/kg for, Zn (16417.69, Pb (143.80, Cr (99.30, and Cd (7.54 in bottom ash and these were above allowable limits for disposal in landfill. The study also found soils within 60 m radius of the incinerator to be polluted with the metals. It is recommended that health care waste managers be educated on the implication of improper management of incinerator bottom ash and regulators monitor hospital waste incinerator sites.

  20. Heavy Metal Contamination of Soils around a Hospital Waste Incinerator Bottom Ash Dumps Site

    Science.gov (United States)

    Adama, M.; Esena, R.; Fosu-Mensah, B.; Yirenya-Tawiah, D.

    2016-01-01

    Waste incineration is the main waste management strategy used in treating hospital waste in many developing countries. However, the release of dioxins, POPs, and heavy metals in fly and bottom ash poses environmental and public health concerns. To determine heavy metal (Hg, Pb, Cd, Cr, and Ag) in levels in incinerator bottom ash and soils 100 m around the incinerator bottom ash dump site, ash samples and surrounding soil samples were collected at 20 m, 40 m, 60 m, 80 m, 100 m, and 1,200 m from incinerator. These were analyzed using the absorption spectrophotometer method. The geoaccumulation (I geo) and pollution load indices (PLI) were used to assess the level of heavy metal contamination of surrounding soils. The study revealed high concentrations in mg/kg for, Zn (16417.69), Pb (143.80), Cr (99.30), and Cd (7.54) in bottom ash and these were above allowable limits for disposal in landfill. The study also found soils within 60 m radius of the incinerator to be polluted with the metals. It is recommended that health care waste managers be educated on the implication of improper management of incinerator bottom ash and regulators monitor hospital waste incinerator sites. PMID:27034685

  1. The effect of waste water treatment on river metal concentrations: removal or enrichment?

    NARCIS (Netherlands)

    Teuchies, J.; Bervoets, L.; Cox, T.J.S.; Meire, P.; de Deckere, E.

    2011-01-01

    Purpose Discharge of untreated domestic and industrial waste in many European rivers resulted in low oxygen concentrations and contamination with trace metals, often concentrated in sediments. Under these anoxic conditions, the formation of insoluble metal sulfides is known to reduce metal

  2. Topotactic Consolidation of Monocrystalline CoZn Hydroxides for Advanced Oxygen Evolution Electrodes.

    Science.gov (United States)

    Wang, Jing; Tan, Chuan Fu; Zhu, Ting; Ho, Ghim Wei

    2016-08-22

    We present a room temperature topotactic consolidation of cobalt and zinc constituents into monocrystalline CoZn hydroxide nanosheets, by a localized corrosion of zinc foils with cobalt precursors. By virtue of similar lattice orientation and structure coordination, the hybrid hydroxides amalgamate atomically without phase separation. Importantly, this in situ growth strategy, in combination with configurable percolated nanosheets, renders a high areal density of catalytic sites, immobilized structures, and conductive pathways between the nanosheets and underlying foils-all of which allow monocrystalline CoZn hydroxide nanosheet materials to function as effective electrodes for electrochemical oxygen evolution reactions. This convenient and eco-friendly topotactical transformation approach facilitates high-quality single crystal growth with improved multiphase purity and homogeneity, which can be extended to other transition metals for the fabrication of advanced functional nanocomposites. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Removal and recovery of radionuclides and toxic metals from wastes, soils and materials

    International Nuclear Information System (INIS)

    Francis, A.J.

    1993-07-01

    A process has been developed at Brookhaven National Laboratory (BNL) for the removal of metals and radionuclides from contaminated materials, soils, and waste sites (Figure 1). In this process, citric acid, a naturally occurring organic complexing agent, is used to extract metals such as Ba, Cd, Cr, Ni, Zn, and radionuclides Co, Sr, Th, and U from solid wastes by formation of water soluble, metal-citrate complexes. Citric acid forms different types of complexes with the transition metals and actinides, and may involve formation of a bidentate, tridentate, binuclear, or polynuclear complex species. The extract containing radionuclide/metal complex is then subjected to microbiological degradation followed by photochemical degradation under aerobic conditions. Several metal citrate complexes are biodegraded and the metals are recovered in a concentrated form with the bacterial biomass. Uranium forms binuclear complex with citric acid and is not biodegraded. The supernatant containing uranium citrate complex is separated and upon exposure to light, undergoes rapid degradation resulting in the formation of an insoluble, stable polymeric form of uranium. Uranium is recovered as a precipitate (uranium trioxide) in a concentrated form for recycling or for appropriate disposal. This treatment process, unlike others which use caustic reagents, does not create additional hazardous wastes for disposal and causes little damage to soil which can then be returned to normal use

  4. THE INFLUENCE OF SELECTED FACTORS ON THE LEACHING OF HEAVY METALS FROM SMELTER WASTE

    OpenAIRE

    Kamila Mizerna; Anna Król

    2015-01-01

    The paper presents the results of leaching research of selected heavy metals (Pb, Cu, Zn, Ni, Cd, Cr) from industrial waste. The impact of waste fragmentation on the level of heavy metals leaching was analyzed. The decrease of copper and zinc release and the increase of nickel leaching were observed with increasing grain size fraction of waste. Furthermore, release of contaminants in different ratio of liquid to solid (L/S = 10 dm3/kg and 2 dm3/kg) was studied. Higher concentrations of heavy ...

  5. Hydrophilic block copolymer-directed growth of lanthanum hydroxide nano-particles

    Energy Technology Data Exchange (ETDEWEB)

    Bouyer, F.; Sanson, N.; Gerardin, C. [Laboratoire de Materiaux Catalytiques et Catalyse en Chimie Organique, UMR 5618 CNRS-ENSCM-UM1, FR 1878, Institut Gerhardt, 34 - Montpellier (France); Destarac, M. [Centre de Recherches Rhodia Aubervilliers, 93 - Aubervilliers (France)

    2006-03-15

    Stable hairy lanthanum hydroxide nano-particles were synthesized in water by performing hydrolysis and condensation reactions of lanthanum cations in the presence of double hydrophilic poly-acrylic acid-b-polyacrylamide block copolymers (PAA-b-PAM). In the first step, the addition of asymmetric PAA-b-PAM copolymers (M{sub w,PAA} {<=} M{sub w,PAM}) to lanthanum salt solutions, both at pH = 5.5, induces the formation of monodispersed micellar aggregates, which are predominantly isotropic. The core of the hybrid aggregates is constituted of a lanthanum polyacrylate complex whose formation is due to bidentate coordination bonding between La{sup 3+} and acrylate groups, as shown by ATR-FTIR experiments and pH measurements. The size of the micellar aggregates depends on the molecular weight of the copolymer but is independent of the copolymer to metal ratio in solution. In the second step, the hydrolysis of lanthanum ions is induced by addition of a strong base such as sodium hydroxide. Either flocculated suspensions or stable anisotropic or spherical nano-particles of lanthanum hydrolysis products were obtained depending on the metal complexation ratio [acrylate]/[La]. The variation of that parameter also enables the control of the size of the core-corona nano-particles obtained by lanthanum hydroxylation. The asymmetry degree of the copolymer was shown to influence both the size and the shape of the particles. Elongated particles with a high aspect ratio, up to 10, were obtained with very asymmetric copolymers (M{sub w,PAM}/M{sub w,PAA}{>=}10) while shorter rice grain-like particles were obtained with a less asymmetric copolymer. The asymmetry degree also influences the value of the critical metal complexation degree required to obtain stable colloidal suspensions of polymer-stabilized lanthanum hydroxide. (authors)

  6. Electrochemical treatment of liquid wastes

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D.T. [Savannah River Technology Center, Aiken, SC (United States)

    1997-10-01

    Under this task, electrochemical treatment processes are being evaluated and developed for the destruction of organic compounds and nitrates/nitrites and the removal of other hazardous species from liquid wastes stored throughout the DOE complex. This technology targets the (1) destruction of nitrates, nitrites and organic compounds; (2) removal of radionuclides; and (3) removal of RCRA metals. The development program consists of five major tasks: (1) evaluation of electrochemical reactors for the destruction and removal of hazardous waste components, (2) development and validation of engineering process models, (3) radioactive laboratory-scale tests, (4) demonstration of the technology in an engineering-scale reactor, and (5) analysis and evaluation of test data. The development program team is comprised of individuals from national laboratories, academic institutions, and private industry. Possible benefits of this technology include: (1) improved radionuclide separation as a result of the removal of organic complexants, (2) reduction in the concentrations of hazardous and radioactive species in the waste (e.g., removal of nitrate, mercury, chromium, cadmium, {sup 99}Tc, and {sup 106}Ru), (3) reduction in the size of the off-gas handling equipment for the vitrification of low-level waste (LLW) by reducing the source of NO{sub x} emissions, (4) recovery of chemicals of value (e.g. sodium hydroxide), and (5) reduction in the volume of waste requiring disposal.

  7. Heavy metal removal from waste waters by ion flotation

    OpenAIRE

    Polat, Hürriyet; Erdoğan, D.

    2007-01-01

    Flotation studies were carried out to investigate the removal of heavy metals such as copper (II), zinc (II), chromium (III) and silver (I) from waste waters. Various parameters such as pH, collector and frother concentrations and airflow rate were tested to determine the optimum flotation conditions. Sodium dodecyl sulfate and hexadecyltrimethyl ammonium bromide were used as collectors. Ethanol and methyl isobutyl carbinol (MIBC) were used as frothers. Metal removal reached about 74% under o...

  8. Towards zero waste production in the minerals and metals sector

    Science.gov (United States)

    Rankin, William J.

    The production of mineral and metal commodities results in large quantities of wastes (solid, liquid and gaseous) at each stage of value-adding — from mining to manufacturing. Waste production (both consumer and non-consumer) is a major contributor to environmental degradation. Approaches to waste management in the minerals industry are largely `after the event'. These have moved progressively from foul-and-flee to dilute-and-disperse to end end-of-pipe treatments. There is now a need to move to approaches which aim to reduce or eliminate waste production at source. Modern waste management strategies include the application of cleaner production principles, the use of wastes as raw materials, the reengineering of process flowsheets to minimise waste production, and use of industrial symbioses through industrial ecology to convert wastes into useful by-products. This paper examines how these can be adopted by the minerals industry, with some recent examples. The financial, technical, systemic and regulatory drivers and barriers are also examined.

  9. Electrochemical corrosion testing of metal waste forms

    International Nuclear Information System (INIS)

    Abraham, D. P.; Peterson, J. J.; Katyal, H. K.; Keiser, D. D.; Hilton, B. A.

    1999-01-01

    Electrochemical corrosion tests have been conducted on simulated stainless steel-zirconium (SS-Zr) metal waste form (MWF) samples. The uniform aqueous corrosion behavior of the samples in various test solutions was measured by the polarization resistance technique. The data show that the MWF corrosion rates are very low in groundwaters representative of the proposed Yucca Mountain repository. Galvanic corrosion measurements were also conducted on MWF samples that were coupled to an alloy that has been proposed for the inner lining of the high-level nuclear waste container. The experiments show that the steady-state galvanic corrosion currents are small. Galvanic corrosion will, hence, not be an important mechanism of radionuclide release from the MWF alloys

  10. Valorization of titanium metal wastes as tanning agent used in leather industry

    Energy Technology Data Exchange (ETDEWEB)

    Crudu, Marian, E-mail: mariancrudu@yahoo.com [The National Research and Development Institute for Textiles and Leather – Division Leather and Footwear Research Institute, 93 Ion Minulescu Str., Bucharest (Romania); Deselnicu, Viorica, E-mail: viorica.deselnicu@icpi.ro [The National Research and Development Institute for Textiles and Leather – Division Leather and Footwear Research Institute, 93 Ion Minulescu Str., Bucharest (Romania); Deselnicu, Dana Corina, E-mail: d_deselnicu@yahoo.com [University Politehnica Bucharest, Splaiul Independentei Nr. 313, Sector 6, RO-060042 Bucharest (Romania); Albu, Luminita, E-mail: luminita.albu@gmail.com [The National Research and Development Institute for Textiles and Leather – Division Leather and Footwear Research Institute, 93 Ion Minulescu Str., Bucharest (Romania)

    2014-10-15

    Highlights: • Valorization of titanium wastes which cannot be recycled in metallurgical industry. • Transferring Ti waste into raw materials for obtaining Ti based tanning agent. • Characterization of new Ti based tanning agents and leather tanned with them. • Characterization of sewage waste water and sludge resulted from leather manufacture. • Analysis of the impact of main metal component of Ti waste. - Abstract: The development of new tanning agents and new technologies in the leather sector is required to cope with the increasingly higher environmental pressure on the current tanning materials and processes such as tanning with chromium salts. In this paper, the use of titanium wastes (cuttings) resulting from the process of obtaining highly pure titanium (ingots), for the synthesis of new tanning agent and tanning bovine hides with new tanning agent, as alternative to tanning with chromium salts are investigated. For this purpose, Ti waste and Ti-based tanning agent were characterized for metal content by inductively coupled plasma mass spectrometry (ICP-MS) and chemical analysis; the tanned leather (wet white leather) was characterized by Scanning Electron Microscope/Energy Dispersive Using X-ray (Analysis). SEM/EDX analysis for metal content; Differential scanning calorimetric (DSC), Micro-Hot-Table and standard shrinkage temperature showing a hydrothermal stability (ranged from 75.3 to 77 °C) and chemical analysis showing the leather is tanned and can be processed through the subsequent mechanical operations (splitting, shaving). On the other hand, an analysis of major minor trace substances from Ti-end waste (especially vanadium content) in new tanning agent and wet white leather (not detected) and residue stream was performed and showed that leachability of vanadium is acceptable. The results obtained show that new tanning agent obtained from Ti end waste can be used for tanning bovine hides, as eco-friendly alternative for chrome tanning.

  11. Valorization of titanium metal wastes as tanning agent used in leather industry

    International Nuclear Information System (INIS)

    Crudu, Marian; Deselnicu, Viorica; Deselnicu, Dana Corina; Albu, Luminita

    2014-01-01

    Highlights: • Valorization of titanium wastes which cannot be recycled in metallurgical industry. • Transferring Ti waste into raw materials for obtaining Ti based tanning agent. • Characterization of new Ti based tanning agents and leather tanned with them. • Characterization of sewage waste water and sludge resulted from leather manufacture. • Analysis of the impact of main metal component of Ti waste. - Abstract: The development of new tanning agents and new technologies in the leather sector is required to cope with the increasingly higher environmental pressure on the current tanning materials and processes such as tanning with chromium salts. In this paper, the use of titanium wastes (cuttings) resulting from the process of obtaining highly pure titanium (ingots), for the synthesis of new tanning agent and tanning bovine hides with new tanning agent, as alternative to tanning with chromium salts are investigated. For this purpose, Ti waste and Ti-based tanning agent were characterized for metal content by inductively coupled plasma mass spectrometry (ICP-MS) and chemical analysis; the tanned leather (wet white leather) was characterized by Scanning Electron Microscope/Energy Dispersive Using X-ray (Analysis). SEM/EDX analysis for metal content; Differential scanning calorimetric (DSC), Micro-Hot-Table and standard shrinkage temperature showing a hydrothermal stability (ranged from 75.3 to 77 °C) and chemical analysis showing the leather is tanned and can be processed through the subsequent mechanical operations (splitting, shaving). On the other hand, an analysis of major minor trace substances from Ti-end waste (especially vanadium content) in new tanning agent and wet white leather (not detected) and residue stream was performed and showed that leachability of vanadium is acceptable. The results obtained show that new tanning agent obtained from Ti end waste can be used for tanning bovine hides, as eco-friendly alternative for chrome tanning

  12. Effective Recovery of Vanadium from Oil Refinery Waste into Vanadium-Based Metal-Organic Frameworks.

    Science.gov (United States)

    Zhan, Guowu; Ng, Wei Cheng; Lin, Wenlin Yvonne; Koh, Shin Nuo; Wang, Chi-Hwa

    2018-03-06

    Carbon black waste, an oil refinery waste, contains a high concentration of vanadium(V) leftover from the processing of crude oil. For the sake of environmental sustainability, it is therefore of interest to recover the vanadium as useful products instead of disposing of it. In this work, V was recovered in the form of vanadium-based metal-organic frameworks (V-MOFs) via a novel pathway by using the leaching solution of carbon black waste instead of commercially available vanadium chemicals. Two different types of V-MOFs with high levels of crystallinity and phase purity were fabricated in very high yields (>98%) based on a coordination modulation method. The V-MOFs exhibited well-defined and controlled shapes such as nanofibers (length: > 10 μm) and nanorods (length: ∼270 nm). Furthermore, the V-MOFs showed high catalytic activities for the oxidation of benzyl alcohol to benzaldehyde, indicating the strong potential of the waste-derived V-MOFs in catalysis applications. Overall, our work offers a green synthesis pathway for the preparation of V-MOFs by using heavy metals of industrial waste as the metal source.

  13. Noble metal behavior during melting of simulated high-level nuclear waste glass feeds

    International Nuclear Information System (INIS)

    Anderson, L.D.; Dennis, T.; Elliott, M.L.; Hrma, P.

    1993-04-01

    Noble metals and their oxides can settle in waste glass melters and cause electrical shorting. Simulated waste feeds from Hanford, Savannah River, and Germany were heat treated for 1 hour in a gradient furnace at temperatures ranging from approximately 600 degrees C--1000 degrees C and examined by electron microscopy to determine shapes, sizes, and distribution of noble metal particles as a function of temperature. Individual noble metal particles and agglomerates of rhodium (Rh), ruthenium (RuO 2 ), and palladium (Pd), as well as their alloys, were seen. the majority of particles and agglomerates were generally less than 10 microns; however, large agglomerations (up to 1 mm) were found in the German feed. Detailed particle distribution and characterization was performed for a Hanford waste to provide input to computer modeling of particle settling in the melter

  14. Heavy Metal Leaching as Affected by Long-Time Organic Waste Fertilizer Application.

    Science.gov (United States)

    Lekfeldt, Jonas Duus Stevens; Holm, Peter E; Kjærgaard, Charlotte; Magid, Jakob

    2017-07-01

    The recycling of urban waste products as fertilizers in agriculture may introduce contaminants such as heavy metals into soil that may leach and contaminate groundwater. In the present study, we investigated the leaching of heavy metals from intact soil cores collected in the long-term agricultural field trial CRUCIAL. At the time of sampling, the equivalent of >100 yr of urban waste fertilizers following Danish legislation had been applied. The leaching of Cu was significantly increased in the treatments receiving organic waste products compared with the unfertilized control but remained below the permissible level following Danish drinking water guidelines. The leaching of Cu was controlled primarily by the topsoil Cu content and by the leaching of dissolved organic carbon (DOC) but at the same time significantly correlated with leaching of colloids in soils that had not received fertilizer or had received an organic fertilizer with a low concentration of Cu. The leaching of Zn, Cd, and Co was not significantly increased in urban waste-fertilized treatments. The leaching of Mo was elevated in accelerated waste treatments (both agricultural and urban), and the leaching of Mo was linked to the leaching of DOC. Since leaching of Cr and Pb was strongly linked to the level of colloid leaching, leaching of these metals was reduced in the urban waste treatments. Overall, the results presented should not raise concern regarding the agricultural use of urban waste products in agriculture as long as the relevant guidelines are followed. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  15. Heavy metal removal from waste waters by ion flotation.

    Science.gov (United States)

    Polat, H; Erdogan, D

    2007-09-05

    Flotation studies were carried out to investigate the removal of heavy metals such as copper (II), zinc (II), chromium (III) and silver (I) from waste waters. Various parameters such as pH, collector and frother concentrations and airflow rate were tested to determine the optimum flotation conditions. Sodium dodecyl sulfate and hexadecyltrimethyl ammonium bromide were used as collectors. Ethanol and methyl isobutyl carbinol (MIBC) were used as frothers. Metal removal reached about 74% under optimum conditions at low pH. At basic pH it became as high as 90%, probably due to the contribution from the flotation of metal precipitates.

  16. Comparison of soil heavy metal pollution caused by e-waste recycling activities and traditional industrial operations.

    Science.gov (United States)

    He, Kailing; Sun, Zehang; Hu, Yuanan; Zeng, Xiangying; Yu, Zhiqiang; Cheng, Hefa

    2017-04-01

    The traditional industrial operations are well recognized as an important source of heavy metal pollution, while that caused by the e-waste recycling activities, which have sprouted in some developing countries, is often overlooked. This study was carried out to compare the status of soil heavy metal pollution caused by the traditional industrial operations and the e-waste recycling activities in the Pearl River Delta, and assess whether greater attention should be paid to control the pollution arising from e-waste recycling activities. Both the total contents and the chemical fractionation of major heavy metals (As, Cr, Cd, Ni, Pb, Cu, and Zn) in 50 surface soil samples collected from the e-waste recycling areas and 20 soil samples from the traditional industrial zones were determined. The results show that the soils in the e-waste recycling areas were mainly polluted by Cu, Zn, As, and Cd, while Cu, Zn, As, Cd, and Pb were the major heavy metals in the soils from the traditional industrial zones. Statistical analyses consistently show that Cu, Cd, Pb, and Zn in the surface soils from both types of sites were contributed mostly by human activities, while As, Cr, and Ni in the soils were dominated by natural background. No clear distinction was found on the pollution characteristic of heavy metals in the surface soils between the e-waste recycling areas and traditional industrial zones. The potential ecological risk posed by heavy metals in the surface soils from both types of sites, which was dominated by that from Cd, ranged from low to moderate. Given the much shorter development history of e-waste recycling and its largely unregulated nature, significant efforts should be made to crack down on illegal e-waste recycling and strengthen pollution control for related activities.

  17. Physical, Chemical and Structural Evolution of Zeolite-Containing Waste Forms Produced from Metakaolinite and Calcined HLW

    International Nuclear Information System (INIS)

    Grutzeck, Michael; Jantzen, Carol M.

    1999-01-01

    Natural and synthetic zeolites are extremely versatile materials. They can adsorb a variety of liquids and gases, and also take part in cation exchange reactions. Zeolites are easy to synthesize from a wide variety of natural and man made materials. One combination of starting materials that exhibits a great deal of promise is a mixture of metakaolinite and/or Class F fly ash and concentrated sodium hydroxide solution. Once these ingredients are mixed and cured at elevated temperatures, they react to form a hard, dense, ceramic-like material that contains significant amounts of crystalline tectosilicates (zeolites and feldspathoids). Zeolites have the ability to sequester ions in lattice positions or within their networks of channels and voids. As such they are nearly perfect waste forms, the zeolites can host alkali, alkaline earth and a variety of higher valance cations. In addition to zeolites, it has been found that the zeolites are accompanied by an alkali aluminosilicate hydrate matrix that is a host, not only to the zeolites, but to residual amounts of insoluble hydroxide phases as well. A previous publication has established the fact that a mixture of a calcined equivalent ICPP waste (sodium aluminate/hydroxide solution containing ∼3:1 Na:Al) and fly ash and/or metakaolinite could be cured at various temperatures to produce a monolith containing Zeolite A (80 C) or Na-P1 plus hydroxy sodalite (130 C) crystals dispersed in an alkali aluminosilicate hydrate matrix. Dissolution tests have shown these materials (so-called hydroceramics) to have superior retention for alkali, alkaline earth and heavy metal ions. The zeolitization process is a simple one. Metakaolinite and/or Class F fly ash is mixed with a caustic sodium-bearing calcine and enough water to make a thick paste. The paste is transferred to a metal canister and ''soaked'' for a few hours at 70-80 C prior to steam autoclaving the sample at ∼200 C for 6-8 hours. The waste form produced in this

  18. The Effect of Pretreatment on the Cesium Adsorption Ability of IONSIV(C)IE-911

    International Nuclear Information System (INIS)

    Fondeur, F.F.

    1999-01-01

    The recovery of plutonium from reactor fuel elements at the Savannah River Site generated nearly 34 million gallons of high level waste. The Site stores the waste as a mixture of precipitated metal hydroxides and associated supernatant liquid with elevated concentrations of free hydroxide. The liquid fraction contains the majority of the radioactive cesium

  19. Release to the gas phase of metals, S and Cl during combustion of dedicated waste fractions

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; van Lith, Simone Cornelia; Frandsen, Flemming

    2010-01-01

    The release to the gas phase of inorganic elements such as alkali metals. Cl, S, and heavy metals in Waste-to-Energy (WtE) boilers is a challenge. Besides the risk of harmful emissions to the environment, inorganic elements released from the grate may cause severe ash deposition and corrosion...... and the link to the formation of fly ash and aerosols in full-scale waste incinerators. The release of metals, S and Cl from four dedicated waste fractions was quantified as a function of temperature in a lab-scale fixed-bed reactor. The waste fractions comprised chromated copper arsenate (CCA) impregnated....... The lab-scale release results were then compared with results from a related, full-scale partitioning study, in which test runs with the addition of similar, dedicated waste fractions to a base-load waste had been performed in a grate-fired WtE boiler. In general, the elements Al, Ca, Cr, Cu, Fe, Mg, Si...

  20. NiMn layered double hydroxide nanosheets/NiCo2O4 nanowires with surface rich high valence state metal oxide as an efficient electrocatalyst for oxygen evolution reaction

    Science.gov (United States)

    Yang, Liting; Chen, Lin; Yang, Dawen; Yu, Xu; Xue, Huaiguo; Feng, Ligang

    2018-07-01

    High valence transition metal oxide is significant for anode catalyst of proton membrane water electrolysis technique. Herein, we demonstrate NiMn layered double hydroxide nanosheets/NiCo2O4 nanowires hierarchical nanocomposite catalyst with surface rich high valence metal oxide as an efficient catalyst for oxygen evolution reaction. A low overpotential of 310 mV is needed to drive a 10 mA cm-2 with a Tafel slope of 99 mV dec-1, and a remarkable stability during 8 h is demonstrated in a chronoamperometry test. Theoretical calculation displays the change in the rate-determining step on the nanocomposite electrode in comparison to NiCo2O4 nanowires alone. It is found high valence Ni and Mn oxide in the catalyst system can efficiently facilitate the charge transport across the electrode/electrolyte interface. The enhanced electrical conductivity, more accessible active sites and synergistic effects between NiMn layered double hydroxide nanosheets and NiCo2O4 nanowires can account for the excellent oxygen evolution reaction. The catalytic performance is comparable to most of the best non-noble catalysts and IrO2 noble catalyst, indicating the promising applications in water-splitting technology. It is an important step in the development of hierarchical nanocomposites by surface valence state tuning as an alternative to noble metals for oxygen evolution reaction.

  1. Preferential growth of short aligned, metallic-rich single-walled carbon nanotubes from perpendicular layered double hydroxide film.

    Science.gov (United States)

    Zhao, Meng-Qiang; Tian, Gui-Li; Zhang, Qiang; Huang, Jia-Qi; Nie, Jing-Qi; Wei, Fei

    2012-04-07

    Direct bulk growth of single-walled carbon nanotubes (SWCNTs) with required properties, such as diameter, length, and chirality, is the first step to realize their advanced applications in electrical and optical devices, transparent conductive films, and high-performance field-effect transistors. Preferential growth of short aligned, metallic-rich SWCNTs is a great challenge to the carbon nanotube community. We report the bulk preferential growth of short aligned SWCNTs from perpendicular Mo-containing FeMgAl layered double hydroxide (LDH) film by a facile thermal chemical vapor deposition with CH(4) as carbon source. The growth of the short aligned SWCNTs showed a decreased growth velocity with an initial value of 1.9 nm s(-1). Such a low growth velocity made it possible to get aligned SWCNTs shorter than 1 μm with a growth duration less than 15 min. Raman spectra with different excitation wavelengths indicated that the as-grown short aligned SWCNTs showed high selectivity of metallic SWCNTs. Various kinds of materials, such as mica, quartz, Cu foil, and carbon fiber, can serve as the substrates for the growth of perpendicular FeMoMgAl LDH films and also the growth of the short aligned SWCNTs subsequently. These findings highlight the easy route for bulk preferential growth of aligned metallic-rich SWCNTs with well defined length for further bulk characterization and applications. This journal is © The Royal Society of Chemistry 2012

  2. Evaluation of heavy metals in the process of composting organic waste of coca leaves

    Directory of Open Access Journals (Sweden)

    Apaza-Condori Emma Eva

    2015-11-01

    Full Text Available The present study is to evaluate the total concentrations of the heavy metals in waste compost samples from coca leaf. This work was carried out Kallutaca Experimental Center, Biofertilizers module Career Agricultural Engineering at the Public University of El Alto, La Paz municipality of Laja. Posed treatments were: T1 (+ Yogurt Coca wastes; T2 (Coca wastes + whey; T3 (Coca wastes + yeast and T4 (Control. The design was completely randomized with 4 treatments and 3 repetitions. The concentration of heavy metals (cadmium, copper, nickel, lead, mercury and chromium; they were categorized into Class A, for the four treatments according to the classifications established by Moreno & Moral (2008.

  3. Selective dissolution followed by EDDS washing of an e-waste contaminated soil: Extraction efficiency, fate of residual metals, and impact on soil environment.

    Science.gov (United States)

    Beiyuan, Jingzi; Tsang, Daniel C W; Valix, Marjorie; Zhang, Weihua; Yang, Xin; Ok, Yong Sik; Li, Xiang-Dong

    2017-01-01

    To enhance extraction of strongly bound metals from oxide minerals and organic matter, this study examined the sequential use of reductants, oxidants, alkaline solvents and organic acids followed by a biodegradable chelating agent (EDDS, [S,S]-ethylene-diamine-disuccinic-acid) in a two-stage soil washing. The soil was contaminated by Cu, Zn, and Pb at an e-waste recycling site in Qingyuan city, China. In addition to extraction efficiency, this study also examined the fate of residual metals (e.g., leachability, bioaccessibility, and distribution) and the soil quality parameters (i.e., cytotoxicity, enzyme activities, and available nutrients). The reductants (dithionite-citrate-bicarbonate and hydroxylamine hydrochloride) effectively extracted metals by mineral dissolution, but elevated the leachability and bioaccessibility of metals due to the transformation from Fe/Mn oxides to labile fractions. Subsequent EDDS washing was found necessary to mitigate the residual risks. In comparison, prior washing by oxidants (persulphate, hypochlorite, and hydrogen peroxide) was marginally useful because of limited amount of soil organic matter. Prior washing by alkaline solvents (sodium hydroxide and sodium bicarbonate) was also ineffective due to metal precipitation. In contrast, prior washing by low-molecular-weight organic acids (citrate and oxalate) improved the extraction efficiency. Compared to hydroxylamine hydrochloride, citrate and oxalate induced lower cytotoxicity (Microtox) and allowed higher enzyme activities (dehydrogenase, acid phosphatase, and urease) and soil nutrients (available nitrogen and phosphorus), which would facilitate reuse of the treated soil. Therefore, while sequential washing proved to enhance extraction efficacy, the selection of chemical agents besides EDDS should also include the consideration of effects on metal leachability/bioaccessibility and soil quality. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Separation of palladium from high-level waste using metal ferro cyanide loaded resins

    International Nuclear Information System (INIS)

    Valsala, T.P.; Joseph, Annie; Yeotikar, R.G.

    2005-01-01

    High-level waste (HLW) is generated during reprocessing of spent fuel. HLW contains corrosion products, unextracted actinides, process chemicals and fission products. A recent trend is there to consider waste as a source of wealth. Among the fission products separation and recovery of platinum group metals have gained great attention. HLW is a good source of palladium of the platinum group metal. The present study shows the feasibility of ion exchange separation of Pd from HLW. (author)

  5. [Correlation of Persistent Free Radicals, PCDD/Fs and Metals in Waste Incineration Fly Ash].

    Science.gov (United States)

    Wang, Tian-jiao; Chen, Tong; Zhan, Ming-xiu; Guo, Ying; Li, Xiao-dong

    2016-03-15

    Environmentally persistent free radicals (EPFRs) are relatively highly stable and found in the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Recent studies have concentrated on model dioxin formation reactions and there are few studies on actual waste incineration fly ash. In order to study EPFRs and the correlation with dioxins and heavy metals in waste incineration fly ash, the spins of EPFRs, concentration of PCDD/Fs and metals in samples from 6 different waste incinerators were detected. The medical waste incineration fly ash from Tianjin, municipal solid waste incineration fly ash from Jiangxi Province, black carbon and slag from municipal solid waste incinerator in Lanxi, Zhejiang Province, all contained EPFRs. Above all the signal in Tianjin sample was the strongest. Hydroxyl radicals, carbon-center radicals and semiquinone radicals were detected. Compared with other samples, Jiangxi fly ash had the highest toxic equivalent quantity (TEQ) of dioxins, up to 7.229 4 ng · g⁻¹. However, the dioxin concentration in the Tianjin sample containing the strongest EPFR signals was only 0.092 8 ng · g⁻¹. There was perhaps little direct numeric link between EPFRs and PCDD/Fs. But the spins of EPFRs in samples presented an increasing trend as the metal contents increased, especially with Al, Fe, Zn. The signal strength of radicals was purposed to be related to the metal contents. The concentration of Zn (0.813 7% ) in the Tianjin sample was the highest and this sample contained much more spins of oxygen-center radicals. We could presume the metal Zn had a greater effect on the formation of EPFRs, and was easier to induce the formation of radicals with a longer half-life period.

  6. Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Cr, Mn, Fe, Co and Ni

    Energy Technology Data Exchange (ETDEWEB)

    Biesinger, Mark C., E-mail: biesingr@uwo.ca [Surface Science Western, University of Western Ontario, University of Western Ontario Research Park, Room LL31, 999 Collip Circle, London, Ontario, N6G 0J3 (Canada); ACeSSS (Applied Centre for Structural and Synchrotron Studies), University of South Australia, Mawson Lakes, SA 5095 (Australia); Payne, Brad P. [Department of Chemistry, University of Western Ontario, London, Ontario, N6A 5B7 (Canada); Grosvenor, Andrew P. [Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5C9 (Canada); Lau, Leo W.M. [Surface Science Western, University of Western Ontario, University of Western Ontario Research Park, Room LL31, 999 Collip Circle, London, Ontario, N6G 0J3 (Canada); Department of Chemistry, University of Western Ontario, London, Ontario, N6A 5B7 (Canada); Gerson, Andrea R.; Smart, Roger St.C. [ACeSSS (Applied Centre for Structural and Synchrotron Studies), University of South Australia, Mawson Lakes, SA 5095 (Australia)

    2011-01-15

    Chemical state X-ray photoelectron spectroscopic analysis of first row transition metals and their oxides and hydroxides is challenging due to the complexity of their 2p spectra resulting from peak asymmetries, complex multiplet splitting, shake-up and plasmon loss structure, and uncertain, overlapping binding energies. Our previous paper [M.C. Biesinger et al., Appl. Surf. Sci. 257 (2010) 887-898.] in which we examined Sc, Ti, V, Cu and Zn species, has shown that all the values of the spectral fitting parameters for each specific species, i.e. binding energy (eV), full wide at half maximum (FWHM) value (eV) for each pass energy, spin-orbit splitting values and asymmetric peak shape fitting parameters, are not all normally provided in the literature and data bases, and are necessary for reproducible, quantitative chemical state analysis. A more consistent, practical and effective approach to curve fitting was developed based on a combination of (1) standard spectra from quality reference samples, (2) a survey of appropriate literature databases and/or a compilation of literature references and (3) specific literature references where fitting procedures are available. This paper extends this approach to the chemical states of Cr, Mn, Fe, Co and Ni metals, and various oxides and hydroxides where intense, complex multiplet splitting in many of the chemical states of these elements poses unique difficulties for chemical state analysis. The curve fitting procedures proposed use the same criteria as proposed previously but with the additional complexity of fitting of multiplet split spectra which has been done based on spectra of numerous reference materials and theoretical XPS modeling of these transition metal species. Binding energies, FWHM values, asymmetric peak shape fitting parameters, multiplet peak separation and peak area percentages are presented. The procedures developed can be utilized to remove uncertainties in the analysis of surface states in nano

  7. The use of sugar and alcohol industry waste in the adsorption of potentially toxic metals.

    Science.gov (United States)

    Santos, Oseas Silva; Mendonça, André Gustavo Ribeiro; Santos, Josué Carinhanha Caldas; Silva, Amanda Paulina Bezerra; Costa, Silvanio Silverio Lopes; Oliveira, Luciana Camargo; Carmo, Janaina Braga; Botero, Wander Gustavo

    2016-01-01

    One of the waste products of the industrial process of the sugar and alcohol agribusiness is filter cake (FC). This waste product has high levels of organic matter, mainly proteins and lipids, and is rich in calcium, nitrogen, potassium and phosphorous. In this work we characterized samples of FC from sugar and alcohol industries located in sugarcane-producing regions in Brazil and assessed the adsorption of potentially toxic metals (Cu(II), Cd(II), Pb(II), Ni(II) and Cr(III)) by this waste in mono- and multi-elemental systems, seeking to use FC as an adsorbent in contaminated environments. The characterization of FCs showed significant differences between the samples and the adsorption studies showed retention of over 90% of potentially toxic metals. In a competitive environment (multi-metallic solution), the FC was effective in adsorbing all metals except lead, but less effective compared to the mono-metallic solution. These results show the potential for use of this residue as an adsorbent in contaminated environments.

  8. Magnesium stearine production via direct reaction of palm stearine and magnesium hydroxide

    Science.gov (United States)

    Pratiwi, M.; Ylitervo, P.; Pettersson, A.; Prakoso, T.; Soerawidjaja, T. H.

    2017-06-01

    The fossil oil production could not compensate with the increase of its consumption, because of this reason the renewable alternative energy source is needed to meet this requirement of this fuel. One of the methods to produce hydrocarbon is by decarboxylation of fatty acids. Vegetable oil and fats are the greatest source of fatty acids, so these can be used as raw material for biohydrocarbon production. From other researchers on their past researchs, by heating base soap from divalent metal, those metal salts will decarboxylate and produce hydrocarbon. This study investigate the process and characterization of magnesium soaps from palm stearine by Blachford method. The metal soaps are synthesized by direct reaction of palm stearine and magnesium hydroxide to produce magnesium stearine and magnesium stearine base soaps at 140-180°C and 6-10 bar for 3-6 hours. The operation process which succeed to gain metal soaps is 180°C, 10 bar, for 3-6 hours. These metal soaps are then compared with commercial magnesium stearate. Based on Thermogravimetry Analysis (TGA) results, the decomposition temperature of all the metal soaps were 250°C. Scanning Electron Microscope with Energy Dispersive X-ray (SEM-EDX) analysis have shown the traces of sodium sulphate for magnesium stearate commercial and magnesium hydroxide for both type of magnesium stearine soaps. The analysis results from Microwave Plasma-Atomic Emission Spectrometry (MP-AES) have shown that the magnesium content of magnesium stearine approximate with magnesium stearate commercial and lower compare with magnesium stearine base soaps. These experiments suggest that the presented saponification process method could produced metal soaps comparable with the commercial metal soaps.

  9. Cobalt hydroxide nanoflakes and their application as supercapacitors and oxygen evolution catalysts

    Science.gov (United States)

    Rovetta, A. A. S.; Browne, M. P.; Harvey, A.; Godwin, I. J.; Coleman, J. N.; Lyons, M. E. G.

    2017-09-01

    Finding alternative routes to access and store energy has become a major issue recently. Transition metal oxides have shown promising behaviour as catalysts and supercapacitors. Recently, liquid exfoliation of bulk metal oxides appears to be an effective route which provides access to two-dimensional (2D) nano-flakes, the size of which can be easily selected. These 2D materials exhibit excellent electrochemical charge storage and catalytic activity for the oxygen evolution reaction. In this study, various sized selected cobalt hydroxide nano-flake materials are fabricated by this time efficient and highly reproducible process. Subsquently, the electrochemical properties of the standard size Co(OH)2 nanoflakes were investigated. The oxide modified electrodes were prepared by spraying the metal oxide flake suspension onto a porous conductive support electrode foam, either glassy carbon or nickel. The cobalt hydroxide/nickel foam system was found to have an overpotential value at 10 mA cm-2 in 1 M NaOH as low as 280 mV and an associated redox capacitance exhibiting numerical values up to 1500 F g-1, thereby making it a viable dual use electrode.

  10. Different Heavy Metal Accumulation Strategies of Epilithic Lichens Colonising Artificial Post-Smelting Wastes.

    Science.gov (United States)

    Rola, Kaja; Osyczka, Piotr; Kafel, Alina

    2016-02-01

    Lichens appear to be essential and effective colonisers of bare substrates including the extremely contaminated wastes of slag dumps. This study examines the metal accumulation capacity of epilithic lichens growing directly on the surface of artificial slag sinters. Four species representing different growth forms, i.e., crustose Candelariella aurella, Lecanora muralis, and Lecidea fuscoatra and fruticose Stereocaulon nanodes, were selected to evaluate the relationships between zinc, lead, cadmium, and nickel contents in their thalli and host substrates. Bioaccumulation factors of examined crustose lichens showed their propensity to hyperaccumulate heavy metals. Contrarily, concentrations of metals in fruticose thalli of S. nanodes were, as a rule, lower than in the corresponding substrates. This indicates that the growth form of thalli and degree of thallus adhesion to the substrate has a significant impact on metal concentrations in lichens colonising post-smelting wastes. Nonlinear regression models described by power functions show that at greater levels of Pb concentration in the substrate, the ability of C. aurella, L. muralis and L. fuscoatra to accumulate the metal experiences a relative decrease, whereas hyperbolic function describes a similar trend in relation to Ni content in S. nanodes. This phenomenon may be an important attribute of lichens that facilitates their colonisation of the surface of slag wastes.

  11. Directions of development of research methods in the assessment of leaching of heavy metals from mineral waste

    Directory of Open Access Journals (Sweden)

    Król Anna

    2016-01-01

    Full Text Available There are many test methods to assess the level of the release of heavy metals into the environment from mineral waste materials. Leaching methods can be different depending on the leaching time periods, leaching dynamics, sample preparation method or the pH of the elution medium. In Poland, little attention is paid to the research on the relationship between the leaching of particular heavy metals from mineral wastes and changes in environmental conditions, including the pH of the environment. Tests being carried out abroad have started to pay great attention to the pH-dependent impact of the environment and the liquid being in contact with the material on the degree of leaching contaminants from wastes. The solubility of all metals depends on the value of the pH. Authors of the paper will try to prove that Polish methods of waste characterization is incomplete and inconsistent with opinions prevailing in the global literature. The procedure described in the Polish standards are insufficient to determine the actual level of leaching of heavy metals having regard to the impact of multiple external conditions on the level of leaching of heavy metals. Paper will present a directions of development of research methods in the assessment of leaching of heavy metals from mineral waste.

  12. Immobilisation of heavy metal in cement-based solidification/stabilisation: A review

    International Nuclear Information System (INIS)

    Chen, Q.Y.; Tyrer, M.; Hills, C.D.; Yang, X.M.; Carey, P.

    2009-01-01

    Heavy metal-bearing waste usually needs solidification/stabilization (s/s) prior to landfill to lower the leaching rate. Cement is the most adaptable binder currently available for the immobilisation of heavy metals. The selection of cements and operating parameters depends upon an understanding of chemistry of the system. This paper discusses interactions of heavy metals and cement phases in the solidification/stabilisation process. It provides a clarification of heavy metal effects on cement hydration. According to the decomposition rate of minerals, heavy metals accelerate the hydration of tricalcium silicate (C 3 S) and Portland cement, although they retard the precipitation of portlandite due to the reduction of pH resulted from hydrolyses of heavy metal ions. The chemical mechanism relevant to the accelerating effect of heavy metals is considered to be H + attacks on cement phases and the precipitation of calcium heavy metal double hydroxides, which consumes calcium ions and then promotes the decomposition of C 3 S. In this work, molecular models of calcium silicate hydrate gel are presented based on the examination of 29 Si solid-state magic angle spinning/nuclear magnetic resonance (MAS/NMR). This paper also reviews immobilisation mechanisms of heavy metals in hydrated cement matrices, focusing on the sorption, precipitation and chemical incorporation of cement hydration products. It is concluded that further research on the phase development during cement hydration in the presence of heavy metals and thermodynamic modelling is needed to improve effectiveness of cement-based s/s and extend this waste management technique

  13. Mesoporous mixed metal oxides derived from P123-templated Mg-Al layered double hydroxides

    International Nuclear Information System (INIS)

    Wang Jun; Zhou Jideng; Li Zhanshuang; He Yang; Lin Shuangshuang; Liu Qi; Zhang Milin; Jiang Zhaohua

    2010-01-01

    We report the preparation of mesoporous mixed metal oxides (MMOs) through a soft template method. Different amounts of P123 were used as structure directing agent to synthesize P123-templated Mg-Al layered double hydroxides (LDHs). After calcination of as-synthesized LDHs at 500 o C, the ordered mesopores were obtained by removal of P123. The mesoporous Mg-Al MMOs fabricated by using 2 wt% P123 exhibited a high specific surface area of 108.1 m 2 /g, and wide distribution of pore size (2-18 nm). An investigation of the 'memory effect' of the mesoporous MMOs revealed that they were successfully reconstructed to ibuprofen intercalated LDHs having different gallery heights, which indicated different intercalation capacities. Due to their mesoporosity these unique MMOs have particular potential as drug or catalyst carriers. - Graphical abstract: Ordered mesoporous Mg-Al MMOs can be obtained through the calcination of P123-templated Mg-Al-CO 3 LDHs. The pore diameter is 2.2 nm. At the presence of ibuprofen, the Mg-Al MMOs can recover to Mg-Al-IBU LDHs, based on its 'remember effect'. Display Omitted

  14. Toxic metals in WEEE: Characterization and substance flow analysis in waste treatment processes

    Energy Technology Data Exchange (ETDEWEB)

    Oguchi, Masahiro, E-mail: oguchi.masahiro@nies.go.jp; Sakanakura, Hirofumi; Terazono, Atsushi

    2013-10-01

    Waste electrical and electronic equipment (WEEE) has received extensive attention as a secondary source of metals. Because WEEE also contains toxic substances such as heavy metals, appropriate management of these substances is important in the recycling and treatment of WEEE. As a basis for discussion toward better management of WEEE, this study characterizes various types of WEEE in terms of toxic metal contents. The fate of various metals contained in WEEE, including toxic metals, was also investigated in actual waste treatment processes. Cathode-ray tube televisions showed the highest concentration and the largest total amount of toxic metals such as Ba, Pb, and Sb, so appropriate recycling and disposal of these televisions would greatly contribute to better management of toxic metals in WEEE. A future challenge is the management of toxic metals in mid-sized items such as audio/visual and ICT equipment because even though the concentrations were not high in these items, the total amount of toxic metals contained in them is not negligible. In the case of Japan, such mid-sized WEEE items as well as small electronic items are subject to municipal solid waste treatment. A case study showed that a landfill was the main destination of toxic metals contained in those items in the current treatment systems. The case study also showed that changes in the flows of toxic metals will occur when treatment processes are modified to emphasize resource recovery. Because the flow changes might lead to an increase in the amount of toxic metals released to the environment, the flows of toxic metals and the materials targeted for resource recovery should be considered simultaneously. - Highlights: ► Appropriate management of toxic metals contained in WEEE is important during recycling and treatment of WEEE. ► CRT TVs contain large amount of toxic metals with high concentration and thus appropriate management is highly important. ► Mid-sized equipment is a future target for

  15. 21 CFR 184.1631 - Potassium hydroxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium hydroxide. 184.1631 Section 184.1631 Food... Specific Substances Affirmed as GRAS § 184.1631 Potassium hydroxide. (a) Potassium hydroxide (KOH, CAS Reg... pellets, flakes, sticks, lumps, and powders. Potassium hydroxide is obtained commercially from the...

  16. Metals and polybrominated diphenyl ethers leaching from electronic waste in simulated landfills

    Energy Technology Data Exchange (ETDEWEB)

    Kiddee, Peeranart [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, Adelaide, 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Mawson Lakes Campus, Adelaide, 5095 (Australia); Naidu, Ravi, E-mail: ravi.naidu@crccare.com [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, Adelaide, 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Mawson Lakes Campus, Adelaide, 5095 (Australia); Wong, Ming H. [Croucher Institute for Environmental Sciences, and Department of Biology, Hong Kong Baptist University, Kowloon Tong (China)

    2013-05-15

    Highlights: • Simulated landfill columns provided realistic results than lab based column study. • Column leachates showed significant seasonal effect on toxic substances. • Toxic substances in the landfill leachates pose environmental and health hazards. • A better management of e-waste is urgently needed. -- Abstract: Landfills established prior to the recognition of potential impacts from the leaching of heavy metals and toxic organic compounds often lack appropriate barriers and pose significant risks of contamination of groundwater. In this study, bioavailable metal(oids) and polybrominated diphenyl ethers (PBDEs) in leachates from landfill columns that contained intact or broken e-waste were studied under conditions that simulate landfills in terms of waste components and methods of disposal of e-wastes, and with realistic rainfall. Fourteen elements and PBDEs were analysed in leachates over a period of 21 months. The results demonstrate that the average concentrations of Al, Ba, Be, Cd, Co, Cr, Cu, Ni, Pb, Sb and V in leachates from the column that contained broken e-waste items were significantly higher than the column without e-waste. BDE-153 was the highest average PBDEs congener in all columns but the average of ∑PBDEs levels in columns that contained intact e-waste were (3.7 ng/l) and were not significantly higher than that in the leachates from the control column.

  17. Characterization of Solids in Residual Wastes from Single-Shell Tanks at the Hanford Site, Washington, USA - 9277

    International Nuclear Information System (INIS)

    Krupka, Kenneth M.; Cantrell, Kirk J.; Schaef, Herbert T.; Arey, Bruce W.; Heald, Steve M.; Deutsch, William J.; Lindberg, Michael J.

    2009-01-01

    Solid-phase characterization methods have been used in an ongoing study of residual wastes (i.e., waste remaining after final retrieval operations) from the underground single-shell storage tanks 241-C-103, 241-C-106, 241-C-202, 241-C-203, and 241-S-112 at the U.S. Department of Energy's Hanford Site in Washington State. The results of studies completed to date show significant variability in the compositions of those residual wastes and the compositions, morphologies, and crystallinities of the individual phases that make up these wastes. These differences undoubtedly result from the various waste types stored and transferred in and out each tank and the sluicing and retrieval operations used for waste retrieval. Our studies indicate that these residual wastes are chemically-complex assemblages of crystalline and amorphous solids that contain contaminants as discrete phases and/or co-precipitated within oxide phases. Depending on the specific tank, various solids (e.g., gibbsite; boehmite; dawsonite; cancrinite; Fe oxides such as hematite, goethite, and maghemite; rhodochrosite; lindbergite; whewellite; nitratine; and numerous amorphous or poorly crystalline phases) have been identified by X-ray diffraction and scanning electron microscopy/energy dispersive X-ray spectroscopy in residual wastes studied to date. Our studies also show that contact of residual wastes with Ca(OH)2- and CaCO3-saturated aqueous solutions, which were used as surrogates for the compositions of pore-fluid leachants derived from young and aged cements respectively, may alter the compositions of solid phases present in the contacted wastes. Fe oxides/hydroxides have been identified in all residual wastes studied to date. They occur in these wastes as discrete particles, particles intergrown within a matrix of other phases, and surface coatings on other particles or particle aggregates. These Fe oxides/hydroxides typically contain trace concentrations of other transition metals, such Cr, Mn

  18. Municipal compost-based mixture for acid mine drainage bioremediation: Metal retention mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Oriol Gibert; Joan de Pablo; Jose Luis Cortina; Carlos Ayora [Universitat Politecnica de Catalunya, Barcelona (Spain). Departament d' Enginyeria Qumica

    2005-09-15

    An upflow packed column was operated to evaluate the potential of a mixture of municipal compost and calcite to promote sulphidogenesis in the remediation of a simulated mine water at high flows (>0.1 m d{sup -1}). Results showed that the pH was neutralised and metals (Fe, Al, Zn, Cu) were significantly removed. Metal removal was attributed to the combined result of precipitation as metal (oxy)hydroxides and carbonates, co-precipitation with these (oxy)hydroxides and sorption onto the compost surface rather than to precipitation as metal sulphides. The two last mechanisms are especially significant for Zn, whose hydroxide is not expected to precipitate at pH 6-7. Before the saturation of compost sorption sites, 60% of the influent Zn was estimated to have been removed by co-precipitation with Fe- and Al-(oxy)hydroxide and 40% by sorption onto the municipal compost.

  19. Waste Derived Sorbents and Their Potential Roles in Heavy Metal Remediation Applications

    Directory of Open Access Journals (Sweden)

    Chiang Y. W.

    2013-04-01

    Full Text Available Inorganic waste materials that have the suitable inherent characteristics could be used as precursors for the synthesis of micro- and mesoporous materials, which present great potential to be re-utilized as sorbent materials for heavy metal remediation. Three inorganic waste materials were studied in the present work: water treatment residuals (WTRs from an integrated drinking water/wastewater treatment plant, and fly ash and bottom ash samples from a municipal solid waste incinerator (MSWI. These wastes were converted into three sorbent materials: ferrihydrite-like materials derived from drying of WTRs, hydroxyapatite-like material derived from ultrasound assisted synthesis of MSWI fly ash with phosphoric acid solution, and a zeolitic material derived from alkaline hydrothermal conversion of MSWI bottom ash. The performance of these materials, as well as their equivalent commercially available counterparts, was assessed for the adsorption of multiple heavy metals (As, Cd, Co, Ni, Pb, Zn from synthetic solutions, contaminated sediments and surface waters; and satisfactory results were obtained. In addition, it was observed that the combination of sorbents into sorbent mixtures enhanced the performance levels and, where applicable, stabilized inherently mobile contaminants from the waste derived sorbents.

  20. Slag-based materials for toxic metal and radioactive waste stabilization

    International Nuclear Information System (INIS)

    Langton, C.A.

    1989-01-01

    This paper discusses a salt solution that is a hazardous waste and has both corrosive and metal toxicity characteristics. Objectives of a wasteform designed to stabilize this solution are presented. Disposal site characterization studies are examined

  1. High-sensitive detection by direct interrogation of 14 MeV Acc neutrons, (1). Uranium-contained metal matrix in a waste dram

    International Nuclear Information System (INIS)

    Haruyama, Mitsuo; Takase, Misao; Tobita, Hiroshi; Mori, Takamasa

    2004-01-01

    Previously, authors reported that the 14 MeV-neutron direct interrogation method has made possible measure for the discrimination of clearance levels of concrete solidification uranium waste. In this paper, applicability of the method to metal waste matrix is discussed based on the results of simulation experiments by the continuation energy Monte Carlo calculation code (MVP). The problem is that self-neutron moderation effect in a waste cannot be expected when a waste matrix is metal. To solve this, a moderator is adopted so as to surround a metal waste drum and to slow down suitably a 14 MeV neutrons. The simulation calculation showed that this effect is satisfactorily large. The detection limit of radioactivity concentration to 4.5% enriched uranium has been found to be 0.0973 Bq/g in the metal waste model of 215.59 kg gross weight, in which 61 pipes are stuffed into its drum. Moreover, the position-dependent sensitivity difference in a metal waste drum can be settled as small as to ±13.5%. In conclusion, it can be said that 14 MeV-neutron direct interrogation method can be applied to the waste of a metal system: the detection sensitivity is high enough and the position-dependent sensitivity difference is small admittedly. Hence the method can be applied also to discrimination measurement of the clearance level of metal uranium waste. (author)

  2. Development of simulated tank wastes for the US Department of Energy's Underground Storage Tank Integrated Demonstration

    International Nuclear Information System (INIS)

    Elmore, M.R.; Colton, N.G.; Jones, E.O.

    1992-08-01

    The purpose of the Underground Storage Tank Integrated Demonstration (USTID) is to identify and evaluate technologies that may be used to characterize, retrieve, treat, and dispose of hazardous and radioactive wastes contained in tanks on US Department of Energy sites. Simulated wastes are an essential component of the evaluation process because they provide controlled samples for technology assessment, and minimize costs and risks involved when working with radioactive wastes. Pacific Northwest Laboratory has developed a recipe to simulate Hanford single-shell tank, (SST) waste. The recipe is derived from existing process recipes, and elemental concentrations are based on characterization data from 18 SSTs. In this procedure, salt cake and metal oxide/hydroxide sludge are prepared individually, and mixed together at varying ratios depending on the specific tank, waste to be simulated or the test being conducted. Elemental and physical properties of the stimulant are comparable with analyzed tank samples, and chemical speciation in the simulant is being improved as speciation data for actual wastes become available. The nonradioactive chemical waste simulant described here is useful for testing technologies on a small scale

  3. Heavy metal contamination of soil and water in the vicinity of an abandoned e-waste recycling site: implications for dissemination of heavy metals.

    Science.gov (United States)

    Wu, Qihang; Leung, Jonathan Y S; Geng, Xinhua; Chen, Shejun; Huang, Xuexia; Li, Haiyan; Huang, Zhuying; Zhu, Libin; Chen, Jiahao; Lu, Yayin

    2015-02-15

    Illegal e-waste recycling activity has caused heavy metal pollution in many developing countries, including China. In recent years, the Chinese government has strengthened enforcement to impede such activity; however, the heavy metals remaining in the abandoned e-waste recycling site can still pose ecological risk. The present study aimed to investigate the concentrations of heavy metals in soil and water in the vicinity of an abandoned e-waste recycling site in Longtang, South China. Results showed that the surface soil of the former burning and acid-leaching sites was still heavily contaminated with Cd (>0.39 mg kg(-1)) and Cu (>1981 mg kg(-1)), which exceeded their respective guideline levels. The concentration of heavy metals generally decreased with depth in both burning site and paddy field, which is related to the elevated pH and reduced TOM along the depth gradient. The pond water was seriously acidified and contaminated with heavy metals, while the well water was slightly contaminated since heavy metals were mostly retained in the surface soil. The use of pond water for irrigation resulted in considerable heavy metal contamination in the paddy soil. Compared with previous studies, the reduced heavy metal concentrations in the surface soil imply that heavy metals were transported to the other areas, such as pond. Therefore, immediate remediation of the contaminated soil and water is necessary to prevent dissemination of heavy metals and potential ecological disaster. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. 40 CFR 60.33b - Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Science.gov (United States)

    2010-07-01

    ... combustor metals, acid gases, organics, and nitrogen oxides. 60.33b Section 60.33b Protection of Environment... Constructed on or Before September 20, 1994 § 60.33b Emission guidelines for municipal waste combustor metals, acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals...

  5. Corrosion of metal containers containing cemented radioactive wastes

    International Nuclear Information System (INIS)

    Duffo, G.S.; Farina, S.B.; Schulz, F.M.; Marotta, F

    2010-01-01

    Nuclear activities generate different kinds of radioactive wastes. In the case of Argentina, wastes classified as low and medium level are conditioned in metal drums for final disposal in a repository whose design is based on the use of multiple and independent barriers. Nuclear energy plants generate a large volume of mid-level radioactive wastes, consisting mainly of ion-exchange resins contaminated by fission products. Other contaminated products such as gloves, papers, clothing, rubber and plastic tubing, can be incinerated and the ashes from the combustion also constitute wastes that must be disposed of. These wastes (resins and ashes) must be immobilized in order to avoid the release of radionuclides into the environment. The wastes usually undergo a process of cementing to immobilize them. This work aims to systematically study the process of degradation by corrosion of the steel drums in contact with the cemented resins and with the ashes cemented with the addition of different types and concentrations of aggressive compounds (chloride and sulfate). The specimens are configured so that the parameters of interest for the steel in contact with the cemented materials can be measured. The variables of corrosion potential, electric resistivity of the matrix and polarization resistance (PR) were monitored and show that the presence of chloride increases the susceptibility to corrosion of the drum steel that is in contact with the cement resin matrix

  6. Perovskite-Ni composite: a potential route for management of radioactive metallic waste.

    Science.gov (United States)

    Mahadik, Pooja Sawant; Sengupta, Pranesh; Halder, Rumu; Abraham, G; Dey, G K

    2015-04-28

    Management of nickel - based radioactive metallic wastes is a difficult issue. To arrest the release of hazardous material to the environment it is proposed to develop perovskite coating for the metallic wastes. Polycrystalline BaCe0.8Y0.2O3-δ perovskite with orthorhombic structure has been synthesized by sol-gel route. Crystallographic analyses show, the perovskite belong to orthorhombic Pmcn space group at room temperature, and gets converted to orthorhombic Incn space group at 623K, cubic Pm3m space group (with a=4.434Å) at 1173K and again orthorhombic Pmcn space group at room temperature after cooling. Similar observations have been made from micro-Raman study as well. Microstructural studies of BaCe0.8Y0.2O3-δ-NiO/Ni composites showed absence of any reaction product at the interface. This suggests that both the components (i.e. perovskite and NiO/Ni) of the composite are compatible to each other. Interaction of BaCe0.8Y0.2O3-δ-NiO/Ni composites with simulated barium borosilicate waste glass melt also did not reveal any reaction product at the interfaces. Importantly, uranium from the waste glass melt was found to be partitioned within BaCe0.8Y0.2O3-δ perovskite structure. It is therefore concluded that BaCe0.8Y0.2O3-δ can be considered as a good coating material for management of radioactive Ni based metallic wastes. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Microbial Precipitation of Cr(III)-Hydroxide and Se(0) Nanoparticles During Anoxic Bioreduction of Cr(VI)- and Se(VI)-Contaminated Water.

    Science.gov (United States)

    Kim, Yumi; Oh, Jong-Min; Roh, Yul

    2017-04-01

    This study examined the microbial precipitations of Cr(III)-hydroxide and Se(0) nanoparticles during anoxic bioreductions of Cr(VI) and Se(VI) using metal-reducing bacteria enriched from groundwater. Metal-reducing bacteria enriched from groundwater at the Korea Atomic Energy Research Institute (KAERI) Underground Research Tunnel (KURT), Daejeon, S. Korea were used. Metal reduction and precipitation experiments with the metal-reducing bacteria were conducted using Cr(VI)- and Se(VI)-contaminated water and glucose as a carbon source under an anaerobic environment at room temperature. XRD, SEM-EDX, and TEM-EDX analyses were used to characterize the mineralogy, crystal structure, chemistry, shape, and size distribution of the precipitates. The metal-reducing bacteria reduced Cr(VI) of potassium chromate (K₂CrO₄) to Cr(III) of chromium hydroxide [Cr(OH)3], and Se(VI) of sodium selenate (Na₂SeO₄) to selenium Se(0), with changes of color and turbidity. XRD, SEM-EDX, and TEM-EDX analyses revealed that the chromium hydroxide [Cr(OH)₃] was formed extracellularly with nanoparticles of 20–30 nm in size, and elemental selenium Se(0) nanoparticles had a sphere shape of 50–250 nm in size. These results show that metal-reducing bacteria in groundwater can aid or accelerate precipitation of heavy metals such as Cr(VI) and Se(VI) via bioreduction processes under anoxic environments. These results may also be useful for the recovery of Cr and Se nanoparticles in natural environments.

  8. X-ray diffraction of the diminution in the concentration of heavy metals from industrial waste water sludge

    International Nuclear Information System (INIS)

    Carreno de Leon, M.C.

    1996-01-01

    We worked with an apparatus and process patented for Jaime Vite Torres, in the United States of America, for extracting simultaneously toxic and value metals from foundry sands. In this research, we used similar devices to remove toxic metals of waste water sludge. Generation of solid wastes including dangerous in 1992 in Mexico were 450,000 ton/day in accordance with the National Institut of Ecology (INE-SEDESOL 1992). With the apparatus and process of the present work we obtained two important points, whic are: a) the recovery of metals in solution which can be recycled and, b) an important reduction in the toxic of the wastes which one treated can be handled as normal waste with important savings. From among the metals which it is possible to recover one can mention among others: Au, Pt, Ag, Cr, Mn, Co, Pb, Al, Ni and others. (Author)

  9. Estimated inventory of chemicals added to underground waste tanks, 1944--1975

    International Nuclear Information System (INIS)

    Allen, G.K.

    1976-03-01

    The five major chemical processes, the Bismuth Phosphate process, the Uranium Recovery process, the Redox process, the Purex process, and the Waste Fractionization process have each contributed to give the total Hanford waste chemicals. Each of these processes is studied to determine the total estimated chemicals stored in underground waste tanks. The chemical contents are derived mainly from flowsheet compositions and recorded waste volumes sent to underground storage. The major components and amounts of Hanford waste are sodium hydroxide, 230 million gram-moles (20 million pounds), sodium nitrate, 1400 million gram-moles (270 million pounds), sodium nitrite, 220 million gram-moles (34 million pounds), sodium aluminate, 400 million gram-moles (72 million pounds), and sodium phosphate, 87 million gram-moles (31 million pounds). Chemical analyses of the sludge and salt cake samples are tabulated to determine the chemical characteristics of the solids. A relative chemical toxicity of the Hanford underground waste tank chemicals is developed from maximum permissible chemical concentrations in air and water. The most toxic chemicals are assumed to be sodium phosphate--35%, sodium aluminate--28%, and chromium hydroxide--19%. If air standards set toxicity limits, the most toxic chemicals are bismuth--41%, chromium hydroxide--23%, and fluoride--10%

  10. Formation of mixed hydroxides in the thorium chloride-iron chloride-sodium hydroxide system

    International Nuclear Information System (INIS)

    Krivokhatskij, A.S.; Prokudina, A.F.; Sapozhnikova, T.V.

    1976-01-01

    The process of formation of mixed hydroxides in the system thorium chloride-iron chloride-NaOH was studied at commensurate concentrations of Th and Fe in solution (1:1 and 1:10 mole fractions, respectively) with ionic strength 0.3, 2.1, and 4.1, created with the electrolyte NaCl, at room temperature 22+-1degC. By the methods of chemical, potentiometric, thermographic, and IR-spectrometric analyses, it was shown that all the synthesized precipitates are mechanical mixtures of two phases - thorium hydroxide and iron hydroxide - and not a new hydrated compound. The formal solubility of the precipitates of mixed hydroxides was determined. It was shown that the numerical value of the formal solubility depends on the conditions of formation and age of the precipitates

  11. Embedding of solid high-level wastes into metal and non-metal matrices

    International Nuclear Information System (INIS)

    Geel, J. van; Eschrich, H.; Dobbels, F.; Favre, P.; Sterner, H.

    1980-03-01

    The primary objective of embedding solidification high-level waste forms of high specific activity into a matrix material is to obtain final waste composites with moderate inner temperatures, even at large waste loadings per meter cylinder length. Secondary objectives are to produce a non-porous, crack-free composite product with a durability superior to that of the embedded waste form itself. The temperature distribution in composite material composed of vitreous beads embedded into a metal matrix (vitromets) are compared with that in a vitreous block, of equal heat generation per meter height, during short- and long-term storage. It was found that for storage under water, inner temperatures below 100 0 C are assured in vitromets, produced from short-cooled high-level wastes, and containing high waste loadings per metercanister height. The chemical and mechanical stability, as well as the thermal conductivity have been examined for vitromets containing various matrix materials whereby emphasis is imparted to lead- and aluminum alloys. The corrosion of lead- and aluminum alloys in distilled water, brine solution and dry salt has been examined at temperatures up to 230 0 C and pressures up to 3.5 MPa. Some lead alloys were found to exhibit superior corrosion resistance in these chemical environments than certain reference borosilicate glasses. The deformation behavior of vitromets under axial compression has been investigated at different temperatures and varying height diameter ratios. The maturity of the vitromet production is finally demonstrated by presenting process data from hot-laboratory scale and cold semi-industrial scale production units. (author)

  12. Production of magnesium metal

    Science.gov (United States)

    Blencoe, James G [Harriman, TN; Anovitz, Lawrence M [Knoxville, TN; Palmer, Donald A [Oliver Springs, TN; Beard, James S [Martinsville, VA

    2010-02-23

    A process of producing magnesium metal includes providing magnesium carbonate, and reacting the magnesium carbonate to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The carbon dioxide is used as a reactant in a second process. In another embodiment of the process, a magnesium silicate is reacted with a caustic material to produce magnesium hydroxide. The magnesium hydroxide is reacted with a source of carbon dioxide to produce magnesium carbonate. The magnesium carbonate is reacted to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The invention further relates to a process for production of magnesium metal or a magnesium compound where an external source of carbon dioxide is not used in any of the reactions of the process. The invention also relates to the magnesium metal produced by the processes described herein.

  13. Savannah River Site chemical, metal, and pesticide (CMP) waste vitrification treatability studies

    International Nuclear Information System (INIS)

    Cicero, C.A.

    1997-01-01

    Numerous Department of Energy (DOE) facilities, as well as Department of Defense (DOD) and commercial facilities, have used earthen pits for disposal of chemicals, organic contaminants, and other waste materials. Although this was an acceptable means of disposal in the past, direct disposal into earthen pits without liners or barriers is no longer a standard practice. At the Savannah River Site (SRS), approximately three million pounds of such material was removed from seven chemical, metal, and pesticide disposal pits. This material is known as the Chemical, Metal, and Pesticide (CMP) Pit waste and carries several different listed waste codes depending on the contaminants in the respective storage container. The waste is not classified as a mixed waste because it is believed to be non-radioactive; however, in order to treat the material in a non-radioactive facility, the waste would first have to be screened for radioactivity. The Defense Waste Processing Technology (DWPT) Section of the Savannah River Technology Center (SRTC) was requested by the DOE-Savannah River (SR) office to determine the viability of vitrification of the CMP Pit wastes. Radioactive vitrification facilities exist which would be able to process this waste, so the material would not have to be analyzed for radioactive content. Bench-scale treatability studies were performed by the DWPT to determine whether a homogeneous and durable glass could be produced from the CMP Pit wastes. Homogeneous and durable glasses were produced from the six pits sampled. The optimum composition was determined to be 68.5 wt% CMP waste, 7.2 wt% Na 2 O, 9 wt% CaO, 7.2 wt% Li 2 O and 8.1 wt% Fe 2 O 3 . This glass melted at 1,150 C and represented a two fold volume reduction

  14. Thermochemical treatment of radioactive waste by using powder metal fuels

    International Nuclear Information System (INIS)

    Dmitriev, S.A.; Ojovan, M.I.; Karlina, O.K.

    2001-01-01

    Full text: A thermochemical approach was suggested for treating and conditioning specific streams of radioactive wastes for example spent ion exchange resins, mixed, organic or chlorine-containing radioactive waste as well as in order to decontaminate heavily contaminated surfaces. Conventional treatment methods of such waste encounters serious problems concerning complete destruction of organic molecules and possible emissions of radionuclides, heavy metals and chemically hazardous species or in case of contaminated materials - complete removal of contamination from surface. The thermochemical treatment of radioactive waste uses powdered metal fuels (PMF) that are specifically formulated for the waste composition and react chemically with the waste components. Thermochemical treatment technologies use the energy of chemical reactions in the mixture of waste with PMF to sustain both decomposition and synthesis processes as well as processes of isomorphic substitutions of hazardous elements into stable mineral forms. The composition of the PMF is designed in such a way as to minimise the release of hazardous components and radionuclides in the off gas and to confine the contaminants in the mineral or glass like final products. The thermochemical procedures allow decomposition of organic matter and capturing hazardous radionuclides and chemical species simultaneously. Thermochemical treatment technologies are very efficient, easy to apply, they have low capital investment and can be used both at large and small facilities. An advantage of thermochemical technologies is their autonomy. Thus these technologies can be successfully applied in order to treat small amount of waste without usage of complex and expensive equipment. They can be used also in emergency situations. Currently the thermochemical treatment technologies were developed and demonstrated to be feasible as follows: 1. Decontamination of surfaces; 2. Processing of organic waste; 3. Vitrification of dusty

  15. Nanostructures based on alumina hydroxides inhibit tumor growth

    Science.gov (United States)

    Fomenko, A. N.; Korovin, M. S.

    2017-09-01

    Nanoparticles and nanostructured materials are one of the most promising developments for cancer therapy. Gold nanoparticles, magnetic nanoparticles based on iron and its oxides and other metal oxides have been widely used in diagnosis and treatment of cancer. Much less research attention has been payed to nanoparticles and nanostructures based on aluminum oxides and hydroxides as materials for cancer diagnosis and treatment. However recent investigations have shown promising results regarding these objects. Here, we review the antitumor results obtained with AlOOH nanoparticles.

  16. Effects of adhesions of amorphous Fe and Al hydroxides on surface charge and adsorption of K+ and Cd2+ on rice roots.

    Science.gov (United States)

    Liu, Zhao-Dong; Wang, Hai-Cui; Zhou, Qin; Xu, Ren-Kou

    2017-11-01

    Iron (Fe) and aluminum (Al) hydroxides in variable charge soils attached to rice roots may affect surface-charge properties and subsequently the adsorption and uptake of nutrients and toxic metals by the roots. Adhesion of amorphous Fe and Al hydroxides onto rice roots and their effects on zeta potential of roots and adsorption of potassium (K + ) and cadmium (Cd 2+ ) by roots were investigated. Rice roots adsorbed more Al hydroxide than Fe hydroxide because of the greater positive charge on Al hydroxide. Adhesion of Fe and Al hydroxides decreased the negative charge on rice roots, and a greater effect of the Al hydroxide. Consequently, adhesion of Fe and Al hydroxides reduced the K + and Cd 2+ adsorption by rice roots. The results of attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and desorption of K + and Cd 2+ from rice roots indicated that physical masking by Fe and Al hydroxides and diffuse-layer overlapping between the positively-charged hydroxides and negatively-charged roots were responsible for the reduction of negative charge on roots induced by adhesion of the hydroxides. Therefore, the interaction between Fe and Al hydroxides and rice roots reduced negative charge on roots and thus inhibited their adsorption of nutrient and toxic cations. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Insights into metals in individual fine particles from municipal solid waste using synchrotron radiation-based micro-analytical techniques

    Institute of Scientific and Technical Information of China (English)

    Yumin Zhu; Hua Zhang; Liming Shao; Pinjing He

    2015-01-01

    Excessive inter-contamination with heavy metals hampers the application of biological treatment products derived from mixed or mechanically-sorted municipal solid waste (MSW).In this study,we investigated fine particles of <2 mm,which are small fractions in MSW but constitute a significant component of the total heavy metal content,using bulk detection techniques.A total of 17 individual fine particles were evaluated using synchrotron radiation-based micro-X-ray fluorescence and micro-X-ray diffraction.We also discussed the association,speciation and source apportionment of heavy metals.Metals were found to exist in a diffuse distribution with heterogeneous intensities and intense hot-spots of <10 μm within the fine particles.Zn-Cu,Pb-Fe and Fe-Mn-Cr had significant correlations in terms of spatial distribution.The overlapped enrichment,spatial association,and the mineral phases of metals revealed the potential sources of fine particles from size-reduced waste fractions (such as scraps of organic wastes or ceramics) or from the importation of other particles.The diverse sources of heavy metal pollutants within the fine particles suggested that separate collection and treatment of the biodegradable waste fraction (such as food waste) is a preferable means of facilitating the beneficial utilization of the stabilized products.

  18. Mechanism of removal and retention of heavy metals from the acid mine drainage to coastal wetland in the Patagonian marsh.

    Science.gov (United States)

    Idaszkin, Yanina L; Carol, Eleonora; María Del Pilar, Alvarez

    2017-09-01

    The attenuation of the acid mine drainage is one of the most important environmental challenges facing the mining industry worldwide. Mining waste deposits from an ancient metallurgical extraction of heavy metals were found near to the San Antonio marsh in Patagonia. The aim of this work was to determinate which mechanisms regulate the mobilization and retention of metals by acid drainage. A geological and geomorphological survey was carried out and samples from the mining waste deposits and the marsh were collected to determine soil texture, Eh pH, organic matter, Cu, Pb, Zn and Fe content, and soil mineralogical composition. Metals in marsh plants were determined in above- and below-ground structures. In the mining waste deposits polymetallic sulphides were recognized where the oxidation and formation of oxy-hydroxides and sulphates of Fe, Cu, Pb and Zn occurs. Then, by the alteration of those minerals, the metals enter in solution and are mobilized with the surface drainage towards the marsh where adsorption in the soils fine fraction and organic matter and/or by plants occurs. Locally, in the mining waste deposits, the precipitation/dissolution of Cu, Pb, and Zn sulphates take place in small centripetal drainage basins. In topographically lower portions of the marsh desorption and removal of metals by tidal flow could also be happen. The results allow to concluding that the marsh adjacent to the mining waste deposits is a geochemically active environment that naturally mitigates the contamination caused by acid drainage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Noble metal behavior during melting of simulated high-level nuclear waste glass feeds

    International Nuclear Information System (INIS)

    Anderson, L.D.; Dennis, T.; Elliott, M.L.; Hrma, P.

    1994-01-01

    Noble metals and their oxides can settle in waste glass melters and cause electrical shorting. Simulate waste feeds from Hanford, Savannah River, and Kernforschungszentrum Karlsruhe were heat treated for 1 hour in a gradient furnace at temperatures ranging from approximately 600 degrees C to 1000 degrees C and examined by electron microscopy to determine shapes, sizes, and distribution of noble metal particles as a function of temperature. Individual noble metal particles and agglomerates of rhodium (Rh), ruthenium (RuO 2 ), and palladium (Pd), as well as their alloys, were seen. The majority of particles and agglomerates were generally less than 10 μm; however, large agglomerations (up to 1 mm) were found in the German feed. 5 refs., 6 figs., 2 tabs

  20. Accurate determination of non-metallic impurities in high purity tetramethylammonium hydroxide using inductively coupled plasma tandem mass spectrometry

    Science.gov (United States)

    Fu, Liang; Xie, Hualin; Shi, Shuyun; Chen, Xiaoqing

    2018-06-01

    The content of non-metallic impurities in high-purity tetramethylammonium hydroxide (HPTMAH) aqueous solution has an important influence on the yield, electrical properties and reliability of the integrated circuit during the process of chip etching and cleaning. Therefore, an efficient analytical method to directly quantify the content of non-metallic impurities in HPTMAH aqueous solutions is necessary. The present study was aimed to develop a novel method that can accurately determine seven non-metallic impurities (B, Si, P, S, Cl, As, and Se) in an aqueous solution of HPTMAH by inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). The samples were measured using a direct injection method. In the MS/MS mode, oxygen and hydrogen were used as reaction gases in the octopole reaction system (ORS) to eliminate mass spectral interferences during the analytical process. The detection limits of B, Si, P, S, Cl, As, and Se were 0.31, 0.48, 0.051, 0.27, 3.10, 0.008, and 0.005 μg L-1, respectively. The samples were analyzed by the developed method and the sector field inductively coupled plasma mass spectrometry (SF-ICP-MS) was used for contrastive analysis. The values of these seven elements measured using ICP-MS/MS were consistent with those measured by SF-ICP-MS. The proposed method can be utilized to analyze non-metallic impurities in HPTMAH aqueous solution. Table S2 Multiple potential interferences on the analytes. Table S3 Parameters of calibration curve and the detection limit (DL). Table S4 Results obtained for 25% concentration high-purity grade TMAH aqueous solution samples (μg L-1, mean ± standard deviation, n = 10).

  1. Metal uptake by native plants and revegetation potential of mining sulfide-rich waste-dumps.

    Science.gov (United States)

    Gomes, Patrícia; Valente, Teresa; Pamplona, Jorge; Braga, Maria Amália Sequeira; Pissarra, José; Gil, José António Grande; de la Torre, Maria Luisa

    2014-01-01

    Waste dumps resulting from metal exploitation create serious environmental damage, providing soil and water degradation over long distances. Phytostabilization can be used to remediate these mining sites. The present study aims to evaluate the behavior of selected plant species (Erica arborea, Ulex europaeus, Agrostis delicatula, and Cytisus multiflorus) that grow spontaneously in three sulfide-rich waste-dumps (Lapa Grande, Cerdeirinha, and Penedono, Portugal). These sites represent different geological, climatic and floristic settings. The results indicate distinctive levels and types of metal contamination: Penedono presents highest sulfate and metal contents, especially As, with low levels of Fe. In contrast, at Lapa Grande and Cerdeirinha Fe, Mn, and Zn are the dominant metals. In accordance, each waste dump develops a typical plant community, providing a specific vegetation inventory. At Penedono, Agrostis delicatula accumulates As, Pb, Cu, Mn, and Zn, showing higher bioaccumulation factors (BF) for Mn (32.1) and As (24.4). At Cerdeirinha, Ulex europaeus has the highest BF for Pb (984), while at Lapa Grande, Erica arborea presents high BF for Mn (9.8) and Pb (8.1). Regarding TF, low values were obtained for most of the metals, especially As (TF < 1). Therefore, the results obtained from representative plant species suggest appropriate behavior for phytostabilization measures.

  2. Treatment of heterogeneous mixed wastes: Enzyme degradation of cellulosic materials contaminated with hazardous organics and toxic and radioactive metals

    International Nuclear Information System (INIS)

    Vanderberg, L.A.; Foreman, T.M.; Attrep, M. Jr.; Brainard, J.R.; Sauer, N.

    1999-01-01

    The redirection and downsizing of the US Department of Energy's nuclear weapons complex requires that many facilities be decontaminated and decommissioned (D and D). At Los Alamos National Laboratory, much of the low-level radioactive, mixed, and hazardous/chemical waste volume handled by waste management operations was produced by D and D and environmental restoration activities. A combination of technologies--air stripping and biodegradation of volatile organics, enzymatic digestion of cellulosics, and metal ion extraction--was effective in treating a radiologically contaminated heterogeneous paint-stripping waste. Treatment of VOCs using a modified bioreactor avoided radioactive contamination of byproduct biomass and inhibition of biodegradation by toxic metal ions in the waste. Cellulase digestion of bulk cellulose minimized the final solid waste volume by 80%. Moreover, the residue passed TCLP for RCRA metals. Hazardous metals and radioactivity in byproduct sugar solutions were removed using polymer filtration, which employs a combination of water-soluble chelating polymers and ultrafiltration to separate and concentrate metal contaminants. Polymer filtration was used to concentrate RCRA metals and radioactivity into <5% of the original wastewater volume. Permeate solutions had no detectable radioactivity and were below RCRA-allowable discharge limits for Pb and Cr

  3. Synthesis of submicron silver powder from scrap low-temperature co-fired ceramic an e-waste: Understanding the leaching kinetics and wet chemistry.

    Science.gov (United States)

    Swain, Basudev; Shin, Dongyoon; Joo, So Yeong; Ahn, Nak Kyoon; Lee, Chan Gi; Yoon, Jin-Ho

    2018-03-01

    The current study focuses on the understanding of leaching kinetics of metal in the LTCC in general and silver leaching in particular along with wet chemical reduction involving silver nanoparticle synthesis. Followed by metal leaching, the silver was selectively precipitated using HCl as AgCl. The precipitated AgCl was dissolved in ammonium hydroxide and reduced to pure silver metal nanopowder (NPs) using hydrazine as a reductant. Polyvinylpyrrolidone (PVP) used as a stabilizer and Polyethylene glycol (PEG) used as reducing reagent as well as stabilizing reagent to control size and shape of the Ag NPs. An in-depth investigation indicated a first-order kinetics model fits well with high accuracy among all possible models. Activation energy required for the first order reaction was 21.242 kJ mol -1 for Silver. PVP and PEG 1% each together provide better size control over silver nanoparticle synthesis using 0.4 M hydrazine as reductant, which provides relatively regular morphology in comparison to their individual application. The investigation revealed that the waste LTCC (an industrial e-waste) can be recycled through the reported process even in industrial scale. The novelty of reported recycling process is simplicity, versatile and eco-efficiency through which waste LTCC recycling can address various issues like; (i) industrial waste disposal (ii) synthesis of silver nanoparticles from waste LTCC (iii) circulate metal economy within a closed loop cycle in the industrial economies where resources are scarce, altogether. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Radioactive waste management at a Liquid Metal Fast Breeder Reactor

    International Nuclear Information System (INIS)

    Abrams, C.S.; Fryer, R.H.; Witbeck, L.C.

    1979-01-01

    This paper presents the radioactive waste production and management at a Liquid Metal Fast Breeder Reactor-II (EBR-II), which is operated for the US Department of Energy by the Argonne National Laboratory at the Idaho National Engineering Laboratory (INEL). Since this facility, in addition to supplying power has been used to demonstrate the breeder, fuel cycling, and recently operations with defective fuel elements, various categories of waste have been handled safely over some 14 years of operation. Liquid wastes are processed such that the resulting effluent can be discharged to an uncontrolled area. Solid wastes up to 10,000 R/hr are packaged and shipped contamination-free to a disposal site or interim storage with exposures to personnel approximately 10 mrem. Gaseous waste discharges are low such as 143 Ci of noble gases in 1978 and do not have a significant effect on the environment even with operations with breached fuel

  5. PNGMDR 2013-2015. ANDRA's opinion on the development of sector of recycling of VLA ferrous metallic waste

    International Nuclear Information System (INIS)

    2014-01-01

    The scope of this report is to state the ANDRA's opinion on the recycling of very-low-level metallic wastes, and mainly ferrous metallic wastes which are the main stream of them. After having evoked a study jointly performed by EDF, AREVA, the CEA and the ANDRA to assess the technical and economic feasibility of a valorisation of very-low-level metallic wastes in the nuclear sector, this study proposes an assessment of ferrous metals which might be recycled over about thirty years. After having outlined the strong motivation of the ANDRA for such a recycling, the report proposes an overview of the heterogeneous stream of metallic wastes, by distinguishing scrap materials from very heterogeneous origins like those brought to the Cires storage centre, and those with more homogeneous origins (for example, from dismantling activities). The next part proposes an overview of various non coordinated initiatives, notably by the ANDRA, on different storage sites. The report identifies the keys for a successful recycling of contaminated metals in Europe, and the main challenges for the recycling of very-low-level ferrous metal in France (in competition with direct storage, and with the application of the risk-related regulation for some metallic wastes). Some proposals made by the ANDRA are then stated: a reference industrial scheme, and a coordination of actors under the auspices of the State

  6. Examinations of content of heavy metals in municipal solid waste and produced compost

    International Nuclear Information System (INIS)

    Golimowski, J.; Tykarska, A.; Orzechowska, K.

    1993-01-01

    The basic methods of utilization of municipal solid waste are biothermic and aerobic methods to compost. The content of heavy metals in composts depends on the initial their content in wastes as well as on the compost process. The voltammetric method has been applied for measurement of concentration of Zn, Cd, Pb, Cu, Cr, Ni and Hg in the waste and composts samples. (author). 24 refs, 2 figs, 3 tabs

  7. Waste acid/metal solution reduction and recovery by vacuum distillation

    International Nuclear Information System (INIS)

    Jones, E.O.; Wilcox, W.A.; Johnson, N.T.; Bowdish, F.W.

    1995-01-01

    Processes involving distillation under reduced pressure were developed at the Pacific Northwest Laboratory several years ago to recover spent acid solutions generated during the manufacture of nuclear fuel for the N-Reactor at the Hanford site. Following construction and testing of a pilot-plant, the technology was licensed to Viatec Recovery Systems, Inc. for commercialization. The technology developed included specialized distillation and rectification of volatile acids, removal of water and/or volatile acid from sulfuric acid, and precipitation of salts. A key feature of the Waste Acid Detoxification and Reclamation (WADR) technology is the development and use of advanced thermoplastic and fluoropolymer materials of construction in all critical process equipment. The technology was then expanded to include crystallization to recover metal salts for possible reuse. Economic and environmental advantages of the procedures include recovery of acids for reuse, simplification or elimination of the disposal of waste solutions, and possible recovery of metals. Industries expected to benefit from such applications include galvanizing, electroplating, sand leaching and any where metals are cleaned in acid solutions. Currently a modular system has been assembled for recovery of several different spent acid solutions

  8. Cementation and solidification of miscellaneous mixed wastes at the Rocky Flats Environmental Technology Site

    International Nuclear Information System (INIS)

    Phillips, J.A.; Semones, G.B.

    1995-01-01

    The Rocky Flats Environmental Technology Site produces a variety of wastes which are amenable to micro-encapsulation in cement Portland cement is an inexpensive and readily available material for this application. The Waste Projects (WP) group at Rocky Flats evaluated cementation to determine its effectiveness in encapsulating several wastes. These included waste analytical laboratory solutions, incinerator ash, hydroxide precipitation sludge, and an acidic solution from the Delphi process (a chemical oxidation technology being evaluated as an alternative to incineration). WP prepared surrogate wastes and conducted designed experiments to optimize the cement formulation for the waste streams. These experiments used a Taguchi or factorial experimental design, interactions between the variables were also considered in the testing. Surrogate waste samples were spiked with various levels of each of six Resource Conservation and Recovery Act (RCRA) listed metals (Cd, Cr, Ba, Pb, Ni, and Ag), cemented using the optimized formulation, and analyzed for leach resistance using the Toxicity Characteristic Leaching Procedure (TCLP). The metal spike levels chosen were based on characterization data, and also based on an estimate of the highest levels of contaminants suspected in the waste. This paper includes laboratory test results for each waste studied. These include qualitative observations as well as quantitative data from TCLP analyses and environmental cycling studies. The results from these experiments show that cement stabilization of the different wastes can produce final waste forms which meet the current RCRA Land Disposal Restriction (LDR) requirements. Formulations that resulted in LDR compliant waste forms are provided. The volume increases associated with cementation are also lower than anticipated. Future work will include verification studies with actual mixed radioactive waste as well as additional formulation development studies on other waste streams

  9. Automated solid-phase extraction of phenolic acids using layered double hydroxide-alumina-polymer disks.

    Science.gov (United States)

    Ghani, Milad; Palomino Cabello, Carlos; Saraji, Mohammad; Manuel Estela, Jose; Cerdà, Víctor; Turnes Palomino, Gemma; Maya, Fernando

    2018-01-26

    The application of layered double hydroxide-Al 2 O 3 -polymer mixed-matrix disks for solid-phase extraction is reported for the first time. Al 2 O 3 is embedded in a polymer matrix followed by an in situ metal-exchange process to obtain a layered double hydroxide-Al 2 O 3 -polymer mixed-matrix disk with excellent flow-through properties. The extraction performance of the prepared disks is evaluated as a proof of concept for the automated extraction using sequential injection analysis of organic acids (p-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid, gallic acid) following an anion-exchange mechanism. After the solid-phase extraction, phenolic acids were quantified by reversed-phase high-performance liquid chromatography with diode-array detection using a core-shell silica-C18 stationary phase and isocratic elution (acetonitrile/0.5% acetic acid in pure water, 5:95, v/v). High sensitivity and reproducibility were obtained with limits of detection in the range of 0.12-0.25 μg/L (sample volume, 4 mL), and relative standard deviations between 2.9 and 3.4% (10 μg/L, n = 6). Enrichment factors of 34-39 were obtained. Layered double hydroxide-Al 2 O 3 -polymer mixed-matrix disks had an average lifetime of 50 extractions. Analyte recoveries ranged from 93 to 96% for grape juice and nonalcoholic beer samples. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Recovery of uranium and accompanying metals from various types of industrial wastes

    International Nuclear Information System (INIS)

    Chajduk, E.; Danko, B.; Gajda, D.; Zakrzewska, G.; Harasimowicz, M.; Bieluszka, P.

    2014-01-01

    On January 28"t"h 2014 the Program of Polish Nuclear Energy was signed by Polish Government. According to this program Poland has to secure a constant supply of uranium for Polish NPPs in the future. Uranium in Poland occurs in Vistula Spit area in sandstone rocks and Podlasie Depression area in black dictyonema shales, which are low grade ores. Scarce uranium resources stimulate interest in its recovery from secondary resources as potential raw materials. Industrial wastes and by-products were considered as a source of uranium in this studies. Apart from uranium other valuable metals (e.g. vanadium, molybdenum or lanthanides) were recovered to improve the economy of the process. Three types of industrial wastes were examined: flotation tailings from the copper industry, phosphoric acid from the fertilizer industry and fracturing fluid from shale gas exploitation. Metals from flotation tailings were separated in two steps: 1) acidic leaching of the flotation waste using sulfuric acid solution and 2) separation of metals by ion-exchange chromatography. All the liquid samples were analyzed by ICP-MS method to determine the separation efficiency of the process. Uranium was recovered from phosphoric acid by high-pressure membrane filtration or by extraction/stripping integrated processes applying membrane modules Liquid-Cel® Extra-Flow (Celgard). Aqueous solutions after hydraulic fracturing are very diverse in terms of chemical composition, depending on borehole and fracturing technology applied. The content of various substances in backflow fluid depends on mechanical behavior and chemical composition of shale. Organic matter content in this type of waste did not exceed 1% usually, but the salinity is high. Initially, organic pollutants were removed and next the fluid was purified by combined various ion-exchangers. Individual metals were selectively eluted from ion-exchanger by combination of different eluents. The content of metals in samples was analyzed by ICP

  11. Production of free fatty acids from waste oil by application of ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Larissa P.; Santos, Francisco F.P.; Costa, Enio; Fernandes, Fabiano A.N. [Universidade Federal do Ceara, Departamento de Engenharia Quimica, Fortaleza, CE (Brazil)

    2012-12-15

    This paper evaluates the production of free fatty acids (FFAs) from waste oil by means of low-frequency high-intensity ultrasound application under atmospheric pressure. To evaluate the potential of this technology, the reaction between waste palm oil and ethanol was carried out. Response surface methodology (RSM) was used to evaluate the influence of alcohol-to-oil weight ratio, potassium hydroxide-to-oil weight ratio, and temperature on the yield of waste oil into FFA. Analysis of the operating conditions by RSM showed that the most important operating conditions affecting the reaction were ethanol-to-oil weight ratio and potassium hydroxide-to-oil weight ratio. The highest yield observed was of 97.3 % after 45 min of reaction. The best operating condition was obtained by applying an ethanol-to-oil weight ratio of 2.4, a potassium hydroxide-to-oil weight ratio of 0.3, and temperature of 60 C. (orig.)

  12. Assessment of biotechnological strategies for the valorization of metal bearing wastes

    International Nuclear Information System (INIS)

    Beolchini, Francesca; Fonti, Viviana; Dell’Anno, Antonio; Rocchetti, Laura; Vegliò, Francesco

    2012-01-01

    Highlights: ► We examine biological strategies to valorize different metal rich solid waste. ► Bacteria play a key role in the mobilization of Zn and Y from fluorescent powders. ► Ferrous iron is crucial for the bioleaching of Ni, V, Mo from spent catalysts. ► No biological effect is observed for Ni, Zn, As, Cr mobilisation from sediments. - Abstract: The present work deals with the application of biotechnology for the mobilization of metals from different solid wastes: end of life industrial catalysts, heavy metal contaminated marine sediments and fluorescent powders coming from a cathode ray tube glass recycling process. Performed experiments were aimed at assessing the performance of acidophilic chemoautotrophic Fe/S-oxidizing bacteria for such different solid matrices, also focusing on the effect of solid concentration and of different substrata. The achieved results have evidenced that metal solubilization seems to be strongly influenced by the metal speciation and partitioning in the solid matrix. No biological effect was observed for Ni, Zn, As, Cr mobilization from marine sediments (34%, 44%, 15%, 10% yields, respectively) due to metal partitioning. On the other hand, for spent refinery catalysts (Ni, V, Mo extractions of 83%, 90% and 40%, respectively) and fluorescent powders (Zn and Y extraction of 55% and 70%, respectively), the improvement in metal extraction observed in the presence of a microbial activity confirms the key role of Fe/S oxidizing bacteria and ferrous iron. A negative effect of solid concentration was in general observed on bioleaching performances, due to the toxicity of dissolved metals and/or to the solid organic component.

  13. Impact of metals in surface matrices from formal and informal electronic-waste recycling around Metro Manila, the Philippines, and intra-Asian comparison

    International Nuclear Information System (INIS)

    Fujimori, Takashi; Takigami, Hidetaka; Agusa, Tetsuro; Eguchi, Akifumi; Bekki, Kanae; Yoshida, Aya; Terazono, Atsushi; Ballesteros, Florencio C.

    2012-01-01

    Highlights: ► We quantified 11 metals in surface matrices from e-waste recycling sites at the Philippines. ► Dust had statistical higher levels of metal contamination and health risk compared to soil. ► Formal and informal sites had different metal contaminations. ► Intra-Asian comparison provided common insight on metal contamination from e-waste recycling. - Abstract: We report concentrations, enrichment factors, and hazard indicators of 11 metals (Ag, As, Cd, Co, Cu, Fe, In, Mn, Ni, Pb, and Zn) in soil and dust surface matrices from formal and informal electronic waste (e-waste) recycling sites around Metro Manila, the Philippines, referring to soil guidelines and previous data from various e-waste recycling sites in Asia. Surface dust from e-waste recycling sites had higher levels of metal contamination than surface soil. Comparison of formal and informal e-waste recycling sites (hereafter, “formal” and “informal”) revealed differences in specific contaminants. Formal dust contained a mixture of serious pollutant metals (Ni, Cu, Pb, and Zn) and Cd (polluted modestly), quite high enrichment metals (Ag and In), and crust-derived metals (As, Co, Fe, and Mn). For informal soil, concentration levels of specific metals (Cd, Co, Cu, Mn, Ni, Pb, and Zn) were similar among Asian recycling sites. Formal dust had significantly higher hazardous risk than the other matrices (p < 0.005), excluding informal dust (p = 0.059, almost significant difference). Thus, workers exposed to formal dust should protect themselves from hazardous toxic metals (Pb and Cu). There is also a high health risk for children ingesting surface matrices from informal e-waste recycling sites.

  14. Study on waste waters of metal finishing industries around Lahore metropolitan area

    International Nuclear Information System (INIS)

    Khan, Izhar-ul-Haq; Mahmood, F.; Tufail, S.; Naeem, M.

    2002-01-01

    Study was undertaken on the waste water samples from metal finishing industries of Lahore metropolitan area for the evaluation of metallic impurities. The metal finishing industry was classified into three categories i. e. medium scale, small scale and cottage scale industry. About 93 wastewater samples were collected from various metal finishing industries around Lahore metropolitan area. In addition to toxic elements like cadmium, nickel and zinc the other parameters such as hydrogen ion concentration (pH), Electrical conductivity (EC) and Total Dissolved Salts (TDS) were also determined. (author)

  15. Formal recycling of e-waste leads to increased exposure to toxic metals: an occupational exposure study from Sweden.

    Science.gov (United States)

    Julander, Anneli; Lundgren, Lennart; Skare, Lizbet; Grandér, Margaretha; Palm, Brita; Vahter, Marie; Lidén, Carola

    2014-12-01

    Electrical and electronic waste (e-waste) contains multiple toxic metals. However, there is currently a lack of exposure data for metals on workers in formal recycling plants. The objective of this study was to evaluate workers' exposure to metals, using biomarkers of exposure in combination with monitoring of personal air exposure. We assessed exposure to 20 potentially toxic metals among 55 recycling workers and 10 office workers at three formal e-waste recycling plants in Sweden. Workers at two of the plants were followed-up after 6 months. We collected the inhalable fraction and OFC (37-mm) fraction of particles, using personal samplers, as well as spot samples of blood and urine. We measured metal concentrations in whole blood, plasma, urine, and air filters using inductively coupled plasma-mass spectrometry following acid digestion. The air sampling indicated greater airborne exposure, 10 to 30 times higher, to most metals among the recycling workers handling e-waste than among the office workers. The exposure biomarkers showed significantly higher concentrations of chromium, cobalt, indium, lead, and mercury in blood, urine, and/or plasma of the recycling workers, compared with the office workers. Concentrations of antimony, indium, lead, mercury, and vanadium showed close to linear associations between the inhalable particle fraction and blood, plasma, or urine. In conclusion, our study of formal e-waste recycling shows that workers performing recycling tasks are exposed to multiple toxic metals. Copyright © 2014. Published by Elsevier Ltd.

  16. A study of the metal content of municipal solid waste. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Churney, K.L.; Domalski, E.S.

    1998-01-01

    Knowledge of the content of toxic components, so called pollutant precursors, in the municipal solid waste (MSW) stream is essential to development of the strategies for source reduction and reuse, recycling, composting and disposal. Data are scarce; trends in composition for any locality even more so. In a previous study the total and water soluble chlorine content of the components of municipal solid waste were determined from sampling studies at two sites, Baltimore County, MD, and Brooklyn, NY, each for a five day period. The total sulfur content of the combined combustible components was also determined. Because of the scarcity of data and synergistic effects, it seemed appropriate to determine the heavy metal content of the preceding material prior to its disposal. The metals chosen were the so-called priority pollutant metals (PPM): antimony, arsenic, beryllium, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, thallium, and zinc.

  17. Investigation of the possibility of using hydrogranulation in reprocessing radioactive wastes of radiochemical production facilities

    Energy Technology Data Exchange (ETDEWEB)

    Revyakin, V.; Borisov, L.M. [All Russian Scientific and Research Institute of Non-Organic Materials, Moscow (Russian Federation)

    1996-05-01

    Radio-chemical production facilities are constantly accumulating liquid radioactive wastes (still residues as the result of evaporation of extraction and adsorption solutions etc.) which are a complex multicomponent mixtures. The wastes are frequently stored for extended periods of time while awaiting disposition and in some cases, and this is much worse, they are released into the environment. In this report, I would like to draw your attention to some results we have obtained from investigations aimed at simplifying handing of such wastes by the precipitation of hard to dissolve metal hydroxides, the flocculation of the above into granules with the help of surface-active agents (in this case a polyacrylamide - PAA), quickly precipitated and easily filtered. The precipitate may be quickly dried and calcinated, if necessary, and transformed into a dense oxide sinter. In other words it may be transformed into a material convenient for storage or burial.

  18. Studies of corrosion in metallic container for storage of high level radioactive wastes

    International Nuclear Information System (INIS)

    Azkarate, I.; Madina, V.; Insausti, M.

    1999-01-01

    The metallic container is one of the most important barriers that, along with engineered and natural barriers, will isolate high level nuclear waste in saline and granite geological formations from the geosphere. However, general and localized corrosion modes such as stress corrosion cracking (SCC), pitting, crevice corrosion and hydrogen damage can be active under disposal conditions, so the corrosion behaviour of the metal container material must be carefully studied. Several metals and their alloys have been proposed for the fabrication of nuclear waste containers including carbon steels, stainless steels, titanium and titanium alloys and copper and copper-base alloys. Carbon steels and copper alloys are considered for the two rock formations, titanium is considered for salt environments and the stainless steel only in the case of a granite formation. (Author)

  19. Spatial distribution of heavy metal contamination in soils near a primitive e-waste recycling site.

    Science.gov (United States)

    Quan, Sheng-Xiang; Yan, Bo; Yang, Fan; Li, Ning; Xiao, Xian-Ming; Fu, Jia-Mo

    2015-01-01

    The total concentrations of 12 heavy metals in surface soils (SS, 0-20 cm), middle soils (MS, 30-50 cm) and deep soils (DS, 60-80 cm) from an acid-leaching area, a deserted paddy field and a deserted area of Guiyu were measured. The results showed that the acid-leaching area was heavily contaminated with heavy metals, especially in SS. The mean concentrations of Ni, Cu, Zn, Cd, Sn, Sb and Pb in SS from the acid-leaching area were 278.4, 684.1, 572.8, 1.36, 3,472, 1,706 and 222.8 mg/kg, respectively. Heavy metal pollution in the deserted paddy field was mainly concentrated in SS and MS. The average values of Sb in SS and MS from the deserted paddy field were 16.3 and 20.2 mg/kg, respectively. However, heavy metal contamination of the deserted area was principally found in the DS. Extremely high concentrations of heavy metals were also observed at some special research sites, further confirming that the level of heavy metal pollution was very serious. The geoaccumulation index (Igeo) values revealed that the acid-leaching area was severely polluted with heavy metals in the order of Sb > Sn > Cu > Cd > Ni > Zn > Pb, while deserted paddy field was contaminated predominately by metals in the order of Sb > Sn > Cu. It was obvious that the concentrations of some uncommon contaminants, such as Sb and Sn, were higher than principal contaminants, such as Ni, Cu, Zn and Pb, suggesting that particular attention should be directed to Sn and Sb contamination in the future research of heavy metals in soils from e-waste-processing areas. Correlation analysis suggested that Li and Be in soils from the acid-leaching area and its surrounding environment might have originated from other industrial activities and from batteries, whereas Ni, Cu, Zn, Cd, Pb, Sn and Sb contamination was most likely caused by uncontrolled electronic waste (e-waste) processing. These results indicate the significant need for optimisation of e-waste-dismantling technologies and remediation of polluted soil

  20. Study on the behavior of heavy metals during thermal treatment of municipal solid waste (MSW) components.

    Science.gov (United States)

    Yu, Jie; Sun, Lushi; Wang, Ben; Qiao, Yu; Xiang, Jun; Hu, Song; Yao, Hong

    2016-01-01

    Laboratory experiments were conducted to investigate the volatilization behavior of heavy metals during pyrolysis and combustion of municipal solid waste (MSW) components at different heating rates and temperatures. The waste fractions comprised waste paper (Paper), disposable chopstick (DC), garbage bag (GB), PVC plastic (PVC), and waste tire (Tire). Generally, the release trend of heavy metals from all MSW fractions in rapid-heating combustion was superior to that in low-heating combustion. Due to the different characteristics of MSW fractions, the behavior of heavy metals varied. Cd exhibited higher volatility than the rest of heavy metals. For Paper, DC, and PVC, the vaporization of Cd can reach as high as 75% at 500 °C in the rapid-heating combustion due to violent combustion, whereas a gradual increase was observed for Tire and GB. Zn and Pb showed a moderate volatilization in rapid-heating combustion, but their volatilities were depressed in slow-heating combustion. During thermal treatment, the additives such as kaolin and calcium can react or adsorb Pb and Zn forming stable metal compounds, thus decreasing their volatilities. The formation of stable compounds can be strengthened in slow-heating combustion. The volatility of Cu was comparatively low in both high and slow-heating combustion partially due to the existence of Al, Si, or Fe in residuals. Generally, in the reducing atmosphere, the volatility of Cd, Pb, and Zn was accelerated for Paper, DC, GB, and Tire due to the formation of elemental metal vapor. TG analysis also showed the reduction of metal oxides by chars forming elemental metal vapor. Cu2S was the dominant Cu species in reducing atmosphere below 900 °C, which was responsible for the low volatility of Cu. The addition of PVC in wastes may enhance the release of heavy metals, while GB and Tire may play an opposite effect. In controlling heavy metal emission, aluminosilicate- and calcium-based sorbents can be co-treated with fuels. Moreover

  1. Development of engineering parameters for the design of metal biosorption waste treatment systems

    Energy Technology Data Exchange (ETDEWEB)

    Graham, W.S.

    1991-12-03

    Untreated landfill leachates and wastes from metal plating and mining operations are sources of environmental contamination by heavy metals. Because of their toxicity and potential for accumulation, the discharge of heavy metals must be controlled. Standard physical and chemical treatments used to remove metals from wastes such as concentration by electro-precipitation, ion exchange, solvent extraction, evaporative recovery, and conventional precipitation, are usually expensive and produce high quantities of sludge. Biosorption is the removal of metals from aqueous solutions by microorganisms. It is called biosorption rather than bioadsorption or bioaccumulation because the mechanisms of removal are not restricted to adsorption or metabolic uptake and so the more general term is preferable and has come to be accepted. In this thesis the focus is one two microorganisms and two metals. However, the possible combinations of conditions such as pH, relative metal molarities, time of contact, and organism are numerous. These experiments are designed to provide optimized parameters to facilitate the design of a functioning biosorption system. The two metals chosen for study are copper and lead in aqueous solution. The two types of microorganisms chosen for testing include an actinomycete and a fungus. The purpose of this research is to identify the significant engineering parameters to be evaluated include reaction rates, equilibrium partitioning of metal ions between those in solution and those removed to the cells, optimum pH for achieving the removal or recovery goal, and biosorption selectivity for one metal over another.

  2. Persimmon leaf bio-waste for adsorptive removal of heavy metals from aqueous solution.

    Science.gov (United States)

    Lee, Seo-Yun; Choi, Hee-Jeong

    2018-03-01

    The aim of this study was to investigate heavy metal removal using waste biomass adsorbent, persimmon leaves, in an aqueous solution. Persimmon leaves, which are biomaterials, have a large number of hydroxyl groups and are highly suitable for removal of heavy metals. Therefore, in this study, we investigated the possibility of removal of Cu, Pb, and Cd in aqueous solution by using raw persimmon leaves (RPL) and dried persimmon leaves (DPL). Removal of heavy metals by RPL and DPL showed that DPL had a 10%-15% higher removal than RPL, and the order of removal efficiency was found to be Pb > Cu > Cd. The pseudo-second order model was a better fit to the heavy metal adsorption experiments using RPL and DPL than the pseudo-first order model. The adsorption of Cu, Pb, and Cd by DPL was more suitable with the Freundlich isothermal adsorption and showed an ion exchange reaction which occurred in the uneven adsorption surface layer. The maximum adsorption capacity of Cu, Pb, and Cd was determined to be 19.42 mg/g, 22.59 mg/g, and 18.26 mg/g, respectively. The result of the adsorption experiments showed that the n value was higher than 2 regardless of the dose, indicating that the heavy metal adsorption on DPL was easy. In the thermodynamic experiment, ΔG° was a negative value, and ΔH° and ΔS° were positive values. It can be seen that the heavy metal adsorption process using DPL was spontaneous in nature and was an endothermic process. Moreover, as the temperature increased, the adsorption increased, and the affinity of heavy metal adsorption to DPL was very good. This experiment, in which heavy metals are removed using the waste biomass of persimmon leaves is an eco-friendly new bioadsorbent method because it can remove heavy metals without using chemicals while utilizing waste recycling. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Closing the Loop: Key Role of Iron in Metal-Bearing Waste Recycling

    Directory of Open Access Journals (Sweden)

    Sedlakova-Kadukova J.

    2017-09-01

    Full Text Available The role of iron in metal-bearing waste bioleaching was studied. Four various types of waste (printed circuit boards (PCBs, Ni-Cd batteries, alkaline batteries and Li-ion batteries were treated by bioleaching using the acidophilic bacteria A. ferrooxidans and A. thiooxidans (separately or in mixture. Role of main leaching agents (Fe3+ ions or sulphuric acid was simulated in abiotic experiments. Results showed that oxidation abilities of Fe3+ ions were crucial for recovery of Cu and Zn from PCBs, with the efficiencies of 88% and 100%, respectively. To recover 68% of Ni from PCBs, and 55% and 100% of Ni and Cd, respectively, from Ni-Cd batteries both oxidation action and hydrolysis of Fe3+ were required. The importance of Fe2+ ions as a reducing agent was showed in bioleaching of Co from Li-ion batteries and Mn from alkaline batteries. The efficiency of the processes has increased by 70% and 40% in Co and Mn bioleaching, respectively, in the presence of Fe2+ ions. Based on the results we suggest the integrated biometallurgical model of metal-bearing waste recycling in the effort to develop zero-waste and less energy-dependent technologies.

  4. Heavy metal removal from municipal solid waste fly ash by chlorination and thermal treatment

    International Nuclear Information System (INIS)

    Nowak, B.; Pessl, A.; Aschenbrenner, P.; Szentannai, P.; Mattenberger, H.; Rechberger, H.; Hermann, L.; Winter, F.

    2010-01-01

    Municipal solid waste (MSW) fly ash is classified as a hazardous material because it contains high amounts of heavy metals. For decontamination, MSW fly ash is first mixed with alkali or alkaline earth metal chlorides (e.g. calcium chloride) and water, and then the mixture is pelletized and treated in a rotary reactor at about 1000deg. C. Volatile heavy metal compounds are formed and evaporate. In this paper, the effect of calcium chloride addition, gas velocity, temperature and residence time on the separation of heavy metals are studied. The fly ash was sampled at the waste-to-energy plant Fernwaerme Wien/Spittelau (Vienna, Austria). The results were obtained from batch tests performed in an indirectly heated laboratory-scale rotary reactor. More than 90% of Cd and Pb and about 60% of Cu and 80% of Zn could be removed in the experiments.

  5. Preparation and Heat-Treatment of DWPF Simulants With and Without Co-Precipitated Noble Metals

    International Nuclear Information System (INIS)

    Koopman, David C.:Eibling, Russel E

    2005-01-01

    The Savannah River National Laboratory is in the process of investigating factors suspected of impacting catalytic hydrogen generation in the Chemical Process Cell of the Defense Waste Processing Facility, DWPF. Noble metal catalyzed hydrogen generation in simulation work constrains the allowable acid addition operating window in DWPF. This constraint potentially impacts washing strategies during sludge batch preparation. It can also influence decisions related to the addition of secondary waste streams to a sludge batch. Noble metals have historically been added as trim chemicals to process simulations. The present study investigated the potential conservatism that might be present from adding the catalytic species as trim chemicals to the final sludge simulant versus co-precipitating the noble metals into the insoluble sludge solids matrix. Parallel preparations of two sludge simulants targeting the composition of Sludge Batch 3 were performed in order to evaluate the impact of the form of noble metals. Identical steps were used except that one simulant had dissolved palladium, rhodium, and ruthenium present during the precipitation of the insoluble solids. Noble metals were trimmed into the other stimulant prior to process tests. Portions of both sludge simulants were held at 97 C for about eight hours to qualitatively simulate the effects of long term storage on particle morphology and speciation. The simulants were used as feeds for Sludge Receipt and Adjustment Tank, SRAT, process simulations. The following conclusions were drawn from the simulant preparation work: (1) The first preparation of a waste slurry simulant with co-precipitated noble metals was successful, based on the data obtained. It appears that 99+% of the noble metals were retained in the simulant. (2) Better control of carbonate, hydroxide, and post-wash trim chemical additions is needed before the new method of simulant preparation will be as reproducible as the old method. (3) The two new

  6. PHYSICAL CHARACTERIZATION OF VITREOUS STATE LABORATORY AY102/C106 AND AZ102 HIGH LEVEL WASTE MELTER FEED SIMULANTS (U)

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, E

    2005-03-31

    The objective of this task is to characterize and report specified physical properties and pH of simulant high level waste (HLW) melter feeds (MF) processed through the scaled melters at Vitreous State Laboratories (VSL). The HLW MF simulants characterized are VSL AZ102 straight hydroxide melter feed, VSL AZ102 straight hydroxide rheology adjusted melter feed, VSL AY102/C106 straight hydroxide melter feed, VSL AY102/C106 straight hydroxide rheology adjusted melter feed, and Savannah River National Laboratory (SRNL) AY102/C106 precipitated hydroxide processed sludge blended with glass former chemicals at VSL to make melter feed. The physical properties and pH were characterized using the methods stated in the Waste Treatment Plant (WTP) characterization procedure (Ref. 7).

  7. Enhancement of the coercivity in Co-Ni layered double hydroxides by increasing basal spacing.

    Science.gov (United States)

    Zhang, Cuijuan; Tsuboi, Tomoya; Namba, Hiroaki; Einaga, Yasuaki; Yamamoto, Takashi

    2016-09-14

    The magnetic properties of layered double hydroxides (LDH) containing transition metal ions can still develop, compared with layered metal hydroxide salts which exhibit structure-dependent magnetism. In this article, we report the preparation of a hybrid magnet composed of Co-Ni LDH and n-alkylsulfonate anions (Co-Ni-CnSO3 LDH). As Co-Ni LDH is anion-exchangeable, we can systematically control the interlayer spacing by intercalating n-alkylsulfonates with different carbon numbers. The magnetic properties were examined with temperature- and field-dependent magnetization measurements. As a result, we have revealed that the coercive field depends on the basal spacing. It is suggested that increasing the basal spacing varies the competition between the in-plane superexchange interactions and long-range out-of-plane dipolar interactions. Moreover, a jump in the coercive field at around 20 Å of the basal spacing is assumed to be the modification of the magnetic ordering in Co-Ni-CnSO3 LDH.

  8. A practical approach to proving waste metals suitable for consignment as radiologically exempt materials - 59266

    International Nuclear Information System (INIS)

    Carvel, Iain; Gunn, Richard D.; Orr, Christopher H.; Strange, Robin

    2012-01-01

    Building 220 at Harwell was built by the Ministry of Works as a Radiochemical Research and Development facility in the latter part of the 1940's. The facility has been operational since 1949 and has been extended several times, most notably the Plutonium Glove Box Wing in the 1950's and the Remote Handling Wing in the 1980's. Only the Remote Handling wing remains operational, processing Historic Waste which is being recovered from storage holes elsewhere on site. The remainder of the facility is undergoing progressive strip out and decommissioning. In the Plutonium Wing and associated areas the waste 'fingerprint' (nuclide vector) consists predominately of alpha emitting radionuclides. Decommissioning and Decontamination (D and D) operations often result in the production of large volumes of scrap metal waste with little or no radioactive contamination. Proving that the waste is clean can be costly and time consuming, as the shape and size of the metallic waste items often means that it is difficult or impossible to monitor all surfaces using conventional hand-held survey meters. This is a particular problem for alpha contamination measurement. Traditional radiological surveying techniques are very labour intensive and involve surveyors checking every surface using hand held instruments and smear sampling the hard to access areas. Even then 100% monitoring cannot be guaranteed. An alternative to traditional methods is the Long Range Alpha Detection (LRAD) technique which remotely detects and measures secondary ionization created in air by alpha particle interactions, allowing extremely low levels of alpha contamination to be measured. A survey system, IonSens R , using the LRAD technique, was developed by BNFL Instruments Ltd (now Babcock Nuclear) which allows rapid surveying of scrap metal for alpha contamination at very low levels. Two versions of this system exist but both essentially comprise a measurement chamber into which scrap metal is placed and sealed

  9. Separation of heavy metals: Removal from industrial wastewaters and contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Peters, R.W.; Shem, L.

    1993-03-01

    This paper reviews the applicable separation technologies relating to removal of heavy metals from solution and from soils in order to present the state-of-the-art in the field. Each technology is briefly described and typical operating conditions and technology performance are presented. Technologies described include chemical precipitation (including hydroxide, carbonate, or sulfide reagents), coagulation/flocculation, ion exchange, solvent extraction, extraction with chelating agents, complexation, electrochemical operation, cementation, membrane operations, evaporation, adsorption, solidification/stabilization, and vitrification. Several case histories are described, with a focus on waste reduction techniques and remediation of lead-contaminated soils. The paper concludes with a short discussion of important research needs in the field.

  10. Separation of heavy metals: Removal from industrial wastewaters and contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Peters, R.W.; Shem, L.

    1993-01-01

    This paper reviews the applicable separation technologies relating to removal of heavy metals from solution and from soils in order to present the state-of-the-art in the field. Each technology is briefly described and typical operating conditions and technology performance are presented. Technologies described include chemical precipitation (including hydroxide, carbonate, or sulfide reagents), coagulation/flocculation, ion exchange, solvent extraction, extraction with chelating agents, complexation, electrochemical operation, cementation, membrane operations, evaporation, adsorption, solidification/stabilization, and vitrification. Several case histories are described, with a focus on waste reduction techniques and remediation of lead-contaminated soils. The paper concludes with a short discussion of important research needs in the field.

  11. Biodiesel from waste cooking oil via base-catalytic and supercritical methanol transesterification

    International Nuclear Information System (INIS)

    Demirbas, Ayhan

    2009-01-01

    In this study, waste cooking oil has subjected to transesterification reaction by potassium hydroxide (KOH) catalytic and supercritical methanol methods obtaining for biodiesel. In catalyzed methods, the presence of water has negative effects on the yields of methyl esters. In the catalytic transesterification free fatty acids and water always produce negative effects since the presence of free fatty acids and water causes soap formation, consumes catalyst, and reduces catalyst effectiveness. Free fatty acids in the waste cooking oil are transesterified simultaneously in supercritical methanol method. Since waste cooking oil contains water and free fatty acids, supercritical transesterification offers great advantage to eliminate the pre-treatment and operating costs. The effects of methanol/waste cooking oils ratio, potassium hydroxide concentration and temperature on the biodiesel conversion were investigated

  12. Method and apparatus for the production of metal oxide powder

    Science.gov (United States)

    Harris, Michael T.; Scott, Timothy C.; Byers, Charles H.

    1992-01-01

    The present invention provides a method for preparing metal oxide powder. A first solution, which is substantially organic, is prepared. A second solution, which is an aqueous solution substantially immiscible in the first solution, is prepared and delivered as drops to the first solution. The drops of the second solution are atomized by a pulsed electric field forming micro-drops of the second solution. Reagents in the first solution diffuse into and react with reactants in the micro-drops of the second solution forming metal hydroxide or oxalate particles. The metal hydroxide or metal oxalate particles are then recovered and dried to produce the metal oxide powder. An apparatus for preparing a metal oxide powder is also disclosed.

  13. New Engineering Solutions in Creation of Mini-BOF for Metallic Waste Recycling

    Science.gov (United States)

    Eronko, S. P.; Gorbatyuk, S. M.; Oshovskaya, E. V.; Starodubtsev, B. I.

    2017-12-01

    New engineering solutions used in design of the mini melting unit capable of recycling industrial and domestic metallic waste with high content of harmful impurities are provided. High efficiency of the process technology implemented with its use is achieved due to the possibility of the heat and mass transfer intensification in the molten metal bath, controlled charge into it of large amounts of reagents in lumps and in fines, and cut-off of remaining process slag during metal tapping into the teeming ladle.

  14. Strategy for synthesizing quantum dot-layered double hydroxide nanocomposites and their enhanced photoluminescence and photostability.

    Science.gov (United States)

    Cho, Seungho; Jung, Sungwook; Jeong, Sanghwa; Bang, Jiwon; Park, Joonhyuck; Park, Youngrong; Kim, Sungjee

    2013-01-08

    Layered double hydroxide-quantum dot (LDH-QD) composites are synthesized via a room temperature LDH formation reaction in the presence of QDs. InP/ZnS (core/shell) QD, a heavy metal free QD, is used as a model constituent. Interactions between QDs (with negative zeta potentials), decorated with dihydrolipoic acids, and inherently positively charged metal hydroxide layers of LDH during the LDH formations are induced to form the LDH-QD composites. The formation of the LDH-QD composites affords significantly enhanced photoluminescence quantum yields and thermal- and photostabilities compared to their QD counterparts. In addition, the fluorescence from the solid LDH-QD composite preserved the initial optical properties of the QD colloid solution without noticeable deteriorations such as red-shift or deep trap emission. Based on their advantageous optical properties, we also demonstrate the pseudo white light emitting diode, down-converted by the LDH-QD composites.

  15. 21 CFR 582.1631 - Potassium hydroxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium hydroxide. 582.1631 Section 582.1631 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1631 Potassium hydroxide. (a) Product. Potassium hydroxide. (b) Conditions of use. This...

  16. Ettringite and C-S-H Portland cement phases for waste ion immobilization: A review

    International Nuclear Information System (INIS)

    Gougar, M.L.D.; Scheetz, B.E.; Roy, D.M.

    1996-01-01

    The formation, structure and chemistry of the ettringite and C-S-H phases of Portland cement have been reviewed as they relate to waste ion immobilization. The purpose of this review was to investigate the use of Portland cement as a host for priority metallic pollutants as identified by the Environmental Protection Agency and as a host for radioactive waste ions as identified in 40 CFR 191. Ettringite acts as host to a number of these ions in both the columnar and channel sections of the crystal structure. Substitutions have been made at the calcium, aluminum, hydroxide and sulfate sites. C-S-H also hosts a number of the waste species in both ionic and salt form. Immobilization mechanisms for C-S-H include sorption, phase mixing and substitution. The following ions have not apparently been reported as specifically immobilized by one of these phases: Ag, Am, Np, Pu, Ra, Tc, Th and Sn; however, some of these ions are immobilized by Portland cement

  17. The analysis on the current status of the overseas recycle technology of the metallic radioactive wastes

    International Nuclear Information System (INIS)

    Shin, Jae In; Kim, Hee Reyoung; Jung, Kee Jung

    2002-05-01

    It was understood that regulation criteria for material release varied with countries and that international standards were not setup. But, most advanced countries are continuously studying on the recycling of metallic wastes for the purpose of the reuse of resources and disposal cost reduction. Practically, the advanced countries make a lot of cost profits compared with disposal as their metallic wastes are recycled and reused through technology like melting. The reasonable international standards are also expected to be set in the near future because of the aggressive cooperation between international agencies such as IAEA and NEA toward recycling these wastes. In our case, the recycle criteria for radioactive waste containing radioactive nuclide with long half-life such as Cs-137(half-life: 30y) and Co-60(half-life: 5.26y) including others, which are generated from the nuclear fission or dismantling of nuclear facilities, are not yet established. Therefore, it is required that the recommendation and legalization of the regulatory criteria be carried out for the recycle and reuse of metallic wastes to be generated from the dismantling of domestic nuclear facilities in the future

  18. Enhanced bioleaching efficiency of metals from E-wastes driven by biochar

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuhua; Zheng, Yue; Yan, Weifu; Chen, Lixiang [CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021 (China); University of Chinese Academy of Sciences, Beijing, 100049 (China); Dummi Mahadevan, Gurumurthy [CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021 (China); Zhao, Feng, E-mail: fzhao@iue.ac.cn [CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021 (China)

    2016-12-15

    Electronic wastes (E-wastes) contain a huge amount of valuable metals that are worth recovering. Bioleaching has attracted widespread attention as an environment-friendly and low-cost technology for the recycling of E-wastes. To avoid the disadvantages of being time-consuming or having a relatively low efficiency, biochar with redox activity was used to enhance bioleaching efficiency of metals from a basic E-waste (i.e., printed circuit boards in this study). The role of biochar was examined through three basic processes: Carbon-mediated, Sulfur-mediated and Iron-mediated bioleaching pathways. Although no obvious enhancement of bioleaching performance was observed in the C-mediated and S-mediated systems, Fe-mediated bioleaching was significantly promoted by the participation of biochar, and its leaching time was decreased by one-third compared with that of a biochar-free system. By mapping the dynamic concentration of Fe(II) and Cu(II), biochar was proved to facilitate the redox action between Fe(II) to Fe(III), which resulted in effective leaching of Cu. Two dominant functional species consisting of Alicyclobacillus spp. and Sulfobacillus spp. may cooperate in the Fe-mediated bioleaching system, and the ratio of these two species was regulated by biochar for enhancing the efficiency of bioleaching. Hence, this work provides a method to improve bioleaching efficiency with low-cost solid redox media.

  19. Enhanced bioleaching efficiency of metals from E-wastes driven by biochar

    International Nuclear Information System (INIS)

    Wang, Shuhua; Zheng, Yue; Yan, Weifu; Chen, Lixiang; Dummi Mahadevan, Gurumurthy; Zhao, Feng

    2016-01-01

    Electronic wastes (E-wastes) contain a huge amount of valuable metals that are worth recovering. Bioleaching has attracted widespread attention as an environment-friendly and low-cost technology for the recycling of E-wastes. To avoid the disadvantages of being time-consuming or having a relatively low efficiency, biochar with redox activity was used to enhance bioleaching efficiency of metals from a basic E-waste (i.e., printed circuit boards in this study). The role of biochar was examined through three basic processes: Carbon-mediated, Sulfur-mediated and Iron-mediated bioleaching pathways. Although no obvious enhancement of bioleaching performance was observed in the C-mediated and S-mediated systems, Fe-mediated bioleaching was significantly promoted by the participation of biochar, and its leaching time was decreased by one-third compared with that of a biochar-free system. By mapping the dynamic concentration of Fe(II) and Cu(II), biochar was proved to facilitate the redox action between Fe(II) to Fe(III), which resulted in effective leaching of Cu. Two dominant functional species consisting of Alicyclobacillus spp. and Sulfobacillus spp. may cooperate in the Fe-mediated bioleaching system, and the ratio of these two species was regulated by biochar for enhancing the efficiency of bioleaching. Hence, this work provides a method to improve bioleaching efficiency with low-cost solid redox media.

  20. Enhanced bioleaching efficiency of metals from E-wastes driven by biochar.

    Science.gov (United States)

    Wang, Shuhua; Zheng, Yue; Yan, Weifu; Chen, Lixiang; Dummi Mahadevan, Gurumurthy; Zhao, Feng

    2016-12-15

    Electronic wastes (E-wastes) contain a huge amount of valuable metals that are worth recovering. Bioleaching has attracted widespread attention as an environment-friendly and low-cost technology for the recycling of E-wastes. To avoid the disadvantages of being time-consuming or having a relatively low efficiency, biochar with redox activity was used to enhance bioleaching efficiency of metals from a basic E-waste (i.e., printed circuit boards in this study). The role of biochar was examined through three basic processes: Carbon-mediated, Sulfur-mediated and Iron-mediated bioleaching pathways. Although no obvious enhancement of bioleaching performance was observed in the C-mediated and S-mediated systems, Fe-mediated bioleaching was significantly promoted by the participation of biochar, and its leaching time was decreased by one-third compared with that of a biochar-free system. By mapping the dynamic concentration of Fe(II) and Cu(II), biochar was proved to facilitate the redox action between Fe(II) to Fe(III), which resulted in effective leaching of Cu. Two dominant functional species consisting of Alicyclobacillus spp. and Sulfobacillus spp. may cooperate in the Fe-mediated bioleaching system, and the ratio of these two species was regulated by biochar for enhancing the efficiency of bioleaching. Hence, this work provides a method to improve bioleaching efficiency with low-cost solid redox media. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Metal Distribution and Mobility under alkaline conditions

    International Nuclear Information System (INIS)

    Dario, Maarten

    2004-01-01

    The adsorption of an element, expressed as its distribution between liquid (aquatic) and solid phases in the bio geosphere, largely determines its mobility and transport properties. This is of fundamental importance in the assessment of the performance of e.g. geologic repositories for hazardous elements like radionuclides. Geologic repositories for low and intermediate level nuclear waste will most likely be based on concrete constructions in a suitable bedrock, leading to a local chemical environment with pH well above 12. At this pH metal adsorption is very high, and thus the mobility is hindered. Organic complexing agents, such as natural humic matter from the ground and in the groundwater, as well as components in the waste (cleaning agents, degradation products from ion exchange resins and cellulose, cement additives etc.) would affect the sorption properties of the various elements in the waste. Trace element migration from a cementitious repository through the pH- and salinity gradient created around the repository would be affected by the presence and creation of particulate matter (colloids) that may serve as carriers that enhance the mobility. The objective of this thesis was to describe and quantify the sorption of some selected elements representative of spent nuclear fuel (Eu, Am) and other heavy metals (Zn, Cd, Hg) in a clay/cement environment (pH 10-13) and in the pH-gradient outside this environment. The potential of organic complexing agents and colloids to enhance metal migration was also investigated. It was shown that many organic ligands are able to reduce trace metal sorption under these conditions. It was not possible to calculate the effect of well-defined organic ligands on the metal sorption in a cement environment by using stability constants from the literature. A simple method for comparing the effect of different complexing agents on metal sorption is, however, suggested. The stability in terms of the particle size of suspended

  2. [Determination of metals in waste bag filter of steel works by microwave digestion-flame atomic absorption spectrometry].

    Science.gov (United States)

    Ning, Xun-An; Zhou, Yun; Liu, Jing-Yong; Wang, Jiang-Hui; Li, Lei; Ma, Xiao-Guo

    2011-09-01

    A method of microwave digestion technique-flame atomic absorption spectrometry was proposed to determine the total contents of Cu, Zn, Pb, Cd, Cr and Ni in five different kinds of waste bag filters from a steel plant. The digestion effects of the six acid systems on the heavy metals digestion were studied for the first time. The relative standard deviation (RSD) of the method was between 1.02% and 9.35%, and the recovery rates obtained by standard addition method ranged from 87.7% to 105.6%. The results indicated that the proposed method exhibited the advantages of simplicity, speediness, accuracy and repeatability, and it was suitable for determining the metal elements of the waste bag filter. The results also showed that different digestion systems should be used according to different waste bag filters. The waste bag filter samples from different production processes had different metal elements content. The Pb and Zn were the highest in the waste bag filters, while the Cu, Ni, Cd and Cr were relatively lower. These determination results provided the scientific data for further treatment and disposal of the waste bag filter.

  3. Function of all-metal separators for waste fuels. Phase 1; Funktion av allmetallseparatorer foer avfallsbraenslen. Etapp 1

    Energy Technology Data Exchange (ETDEWEB)

    Jacoby, Juergen; Wrangensten, Lars

    2004-08-01

    Various waste incineration facilities, which use different types of waste fuels, have difficulties with a high content of non-magnetic metal, especially aluminum in their fuels. Aluminum may melt on the grate and can lead to corrosion or fouling in the furnace. Additionally, a high content of aluminum in the flyash may cause difficulties in terms of storage or further use of the ash as e.g. construction material. The industrial demand for efficient separators for non-magnetic metals from a fuel stream is rather large. There is however some uncertainty in the performance and efficiency of metal separators. Two types of separators can be found, the first type is called eddy current separator, the other type is based upon a metal detector with a sorting unit in the form of a chute or similar afterwards. An eddy current separator consists of a fast rotating drum containing several permanent magnets with alternating polarity. Due to the rotation, the change in the magnetic field induces eddy currents in conducting materials. The eddy currents cause a force in non-magnetic metal, the Lorentz force, which repels the material away from the rotating drum while all other material follows the systems flow direction. Systems equipped with a metal detector activate a mechanical sorting device, separate chute or air nozzles, when a metal particle is detected. In contrast to eddy current separators all types of metals can be detected and sorted out by systems based on metal detector. Several technical solutions for metal separation supplied by various manufacturers are described in the report. The companies have been asked to supply product information on the working principle, technical data, efficiency and limits for different types of metals. Two reference power plants have been visited and their experiences with all-metal separators are described. Haendeloeverket in Norrkoeping uses eddy current separators for separation of non-magnetic metals from household waste

  4. INAA of toxic heavy metals in solid wastes from Indian cities

    International Nuclear Information System (INIS)

    Garg, A.N.; Ramakrishna, V.V.S.; Singh, V.

    1997-01-01

    Solid wastes and sewage sludges in metropolitan cities are potential health hazards due to toxic heavy metal pollutants. Sewage sludges from six Indian cities viz., Ahmedabad, Bikaner, Bombay, Calcutta, Jaipur, Kanpur and solid wastes from six different disposal sites of the capital city of Delhi have been analyzed for 26 elements (As, Au, Ba, Br, Co, Cr, Cs, Cu, Eu, Fe, Hg, Hf, K, La, Mg, Mn, Mo, Na, P, Rb, Sb, Sc, Se, Sr, Th and Zn) by employing instrumental neutron activation analysis (INAA). Sewage sludges from Bombay after different treatments (settled, digested, aerobic, anaerobic) along with several environmental SRMs were also analyzed. An attempt has been made to attribute the pollutant sources to the degree of urbanisation and industrialization of the city. Role of treatment processes in the removal/retention of heavy metals is discussed. (author)

  5. Precipitation of Aluminum Containing Species in Tank Wastes

    International Nuclear Information System (INIS)

    Mattigod, Shas V.; Hobbs, David; Parker, Kent E.; McCready, David E.

    2001-01-01

    Aluminisilicate deposit buildup experienced during the tank waste volume-reduction process at the Savannah River Site (SRS) required an evaporator to be shut down in October 1999. The Waste Processing Technology Section (WPTS) of Westinghouse Savannah River Company at SRS is now collaborating with team members from Pacific Northwest National Laboratory (PNNL) to verify the steady-state thermodynamic stability of aluminosilicate compounds under waste tank conditions in an attempt to eliminate the deposition and clogging problems. The data obtained at 40?C showed that formation and persistence of crystalline phases was dependent on the initial hydroxide concentrations. The formation and persistence of zeolite A occurred only at lower hydroxide concentrations, whereas increasing hydroxide concentrations appeared to promote the formation of sodalite and cancrinite. The data also showed that although zeolite A forms initially, it is a metastable phase that converts to more stable crystalline materials such as sodalite and cancrinite. Additionally, the rate of transformation of zeolite A appeared to increase with increasing hydroxide concentration. The data from tests conducted at 80?C revealed relatively rapid formation of sodalite and cancrinite. Although minor amounts of zeolite A were initially detected in some cases, the higher reaction temperatures seemed to promote very rapid transformation of this phase into more stable phases. Also, the higher temperature and hydroxide concentrations appeared to initiate kinetically fast crystallization of sodalite and cancrinite. More recent testing at SRS in support of the HLW evaporator plugging issue has shown similar trends in the formation of aluminosilicate phases. These tests were carried out under conditions more similar to those that occur in HLW tanks and evaporators. Comparison of our results with those reported above show very similar trends

  6. Sources of heavy metal contamination in Swedish wood waste used for combustion

    International Nuclear Information System (INIS)

    Krook, J.; Martensson, A.; Eklund, M.

    2006-01-01

    In this paper, wood waste (RWW) recovered for heat production in Sweden was studied. Previous research has concluded that RWW contains elevated amounts of heavy metals, causing environmental problems during waste management. This study extends previous work on RWW by analysing which pollution sources cause this contamination. Using existing data on the metal contents in various materials, and the amounts of these materials in RWW, the share of the elevated amounts of metals in RWW that these materials explain was quantified. Six different materials occurring in RWW were studied and the results show that they explain from 70% to 100% of the amounts of arsenic, chromium, lead, copper and zinc in RWW. The most important materials contributing to contamination of RWW are surface-treated wood, industrial preservative-treated wood, plastic and galvanised fastening systems. These findings enable the development and evaluation of strategies aiming to decrease pollution and resource loss from handling RWW. It is argued that source separation and measures taken further downstream from the generation site, such as treatment, need to be combined to substantially decrease the amount of heavy metals in RWW

  7. The role of noble metals in electric melting of nuclear waste glass

    International Nuclear Information System (INIS)

    Roth, G.; Weisenburger, S.

    1990-01-01

    Electrical melting of nuclear waste glass in ceramic melters applies Joule heating, with the molten glass acting as the conductive medium. The local energy release inside the melt relieves from the restriction of external heat addition, allowing to scale up the melter to industrial units. Certainly, that principle makes the melter operation susceptible for changes of the electrical properties of the glass melt. Hence, the melt properties are required to be locally uniform and constant with time. Temporary fluctuations in the feed composition, however, are usually attenuated by the high retention times being in the order of a day and more. More essential for the melter operation are segregation effects occurring systematically. This behaviour can be observed in the case of the so-called noble metal elements Ruthenium, Palladium and Rhodium, belonging to the Platinum metal group. The subject of this paper is to describe the behaviour of the noble metals in electric melting and the problems they can contribute to. The discussion is based on detailed knowledge gained from PAMELA's LEWC processing and from large-scale vitrification of commercial-like waste simulate at INE/KfK. Finally, ways are indicated to solve the noble metal problem technically

  8. Removal of heavy metals from aqueous phases using chemically modified waste Lyocell fiber

    Energy Technology Data Exchange (ETDEWEB)

    Bediako, John Kwame; Wei, Wei; Kim, Sok; Yun, Yeoung-Sang, E-mail: ysyun@jbnu.ac.kr

    2015-12-15

    Highlights: • Waste Lyocell fiber was chemically modified into cellulose xanthate. • The sorbent showed high affinity for Pb(II), Cd(II) and Cu(II) ions. • The sorbent also showed strong Cu(II) selectivity in Pb(II)–Cd(II)–Cu(II) ternary metal solutions. - Abstract: In this study, an outstanding performance of chemically modified waste Lyocell for heavy metals treatment is reported. The sorbent, which was prepared by a simple and concise method, was able to bind heavy metals such as Pb(II), Cu(II) and Cd(II), with very high efficiencies. The binding mechanisms were studied through adsorption and standard characterization tests such as scanning electron microscopy, energy-dispersive spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analyses. Adsorption kinetics was very fast and attained equilibrium within 5 min in all metals studied. The maximum single metal uptakes were 531.29 ± 0.28 mg/g, 505.64 ± 0.21 mg/g, and 123.08 ± 0.26 mg/g for Pb(II), Cd(II) and Cu(II), respectively. In ternary metal systems, Cu(II) selectivity was observed and the underlying factors were discussed. The sorbent by its nature, could be very effective in treating large volumes of wastewater with the contact of very little amount.

  9. Analysis of physical composition and heavy metals pollution of municipal solid waste (MSW) in Beijing

    Science.gov (United States)

    Zhang, H. B.; Zhang, H. Y.; Wang, G. Q.; Bai, X. J.

    2018-03-01

    By using on-site sampling and physical-chemical analysis, the physical composition and the contents of heavy metals in Beijing MSW were researched. The result showed that the main components of MSW in Beijing are mainly kitchen waste, the average content of kitchen waste are more than 60% and 50% in summer and in winter, respectively. The pollution of Cu, Hg and Cr are all more serious for MSW in Haidian and Dongcheng district. The heavy metal pollution of MSW in summer is higher than that in winter in Beijing. Seasonal impacts should be taken into consideration when dealing with MSW. The content of heavy metals in MSW exceeded the background value of soil in Haidian and Dongcheng districts. In order to reduce heavy metal pollution, the MSW should be separated collection and treated.

  10. Scoping evaluation of the technical capabilities of DOE sites for disposal of hazardous metals in mixed low-level waste

    International Nuclear Information System (INIS)

    Gruebel, M.M.; Waters, R.D.; Langkopf, B.S.

    1997-05-01

    A team of analysts designed and conducted a scoping evaluation to estimate the technical capabilities of fifteen Department of Energy sites for disposal of the hazardous metals in mixed low-level waste (i.e., waste that contains both low-level radioactive materials and hazardous constituents). Eight hazardous metals were evaluated: arsenic, barium, cadmium, chromium, lead, mercury, selenium, and silver. The analysis considered transport only through the groundwater pathway. The results are reported as site-specific estimates of maximum concentrations of each hazardous metal in treated mixed low-level waste that do not exceed the performance measures established for the analysis. Also reported are site-specific estimates of travel times of each hazardous metal to the point of compliance

  11. Aluminum Removal From Hanford Waste By Lithium Hydrotalcite Precipitation - Laboratory Scale Validation On Waste Simulants Test Report

    International Nuclear Information System (INIS)

    Sams, T.; Hagerty, K.

    2011-01-01

    To reduce the additional sodium hydroxide and ease processing of aluminum bearing sludge, the lithium hydrotalcite (LiHT) process has been invented by AREV A and demonstrated on a laboratory scale to remove alumina and regenerate/recycle sodium hydroxide prior to processing in the WTP. The method uses lithium hydroxide (LiOH) to precipitate sodium aluminate (NaAI(OH) 4 ) as lithium hydrotalcite (Li 2 CO 3 .4Al(OH) 3 .3H 2 O) while generating sodium hydroxide (NaOH). In addition, phosphate substitutes in the reaction to a high degree, also as a filterable solid. The sodium hydroxide enriched leachate is depleted in aluminum and phosphate, and is recycled to double-shell tanks (DSTs) to leach aluminum bearing sludges. This method eliminates importing sodium hydroxide to leach alumina sludge and eliminates a large fraction of the total sludge mass to be treated by the WTP. Plugging of process equipment is reduced by removal of both aluminum and phosphate in the tank wastes. Laboratory tests were conducted to verify the efficacy of the process and confirm the results of previous tests. These tests used both single-shell tank (SST) and DST simulants.

  12. Precious metal recovery from waste printed circuit boards using cyanide and non-cyanide lixiviants--A review.

    Science.gov (United States)

    Akcil, Ata; Erust, Ceren; Gahan, Chandra Sekhar; Ozgun, Mehmet; Sahin, Merve; Tuncuk, Aysenur

    2015-11-01

    Waste generated by the electrical and electronic devices is huge concern worldwide. With decreasing life cycle of most electronic devices and unavailability of the suitable recycling technologies it is expected to have huge electronic and electrical wastes to be generated in the coming years. The environmental threats caused by the disposal and incineration of electronic waste starting from the atmosphere to the aquatic and terrestrial living system have raised high alerts and concerns on the gases produced (dioxins, furans, polybrominated organic pollutants, and polycyclic aromatic hydrocarbons) by thermal treatments and can cause serious health problems if the flue gas cleaning systems are not developed and implemented. Apart from that there can be also dissolution of heavy metals released to the ground water from the landfill sites. As all these electronic and electrical waste do posses richness in the metal values it would be worth recovering the metal content and protect the environmental from the pollution. Cyanide leaching has been a successful technology worldwide for the recovery of precious metals (especially Au and Ag) from ores/concentrates/waste materials. Nevertheless, cyanide is always preferred over others because of its potential to deliver high recovery with a cheaper cost. Cyanidation process also increases the additional work of effluent treatment prior to disposal. Several non-cyanide leaching processes have been developed considering toxic nature and handling problems of cyanide with non-toxic lixiviants such as thiourea, thiosulphate, aqua regia and iodine. Therefore, several recycling technologies have been developed using cyanide or non-cyanide leaching methods to recover precious and valuable metals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Determination of Heavy Metal Levels in Various Industrial Waste Waters

    Directory of Open Access Journals (Sweden)

    Mustafa Şahin Dündar

    2012-06-01

    Full Text Available Important part of the environmetal pollution consists of waste water and water pollution. The water polluted by anthropogenical, industrial, and agricultural originated sources are defined as waste waters which are the main pollution sources for reservoirs, rivers, lakes, and seas. In this work, waste waters of leather, textile, automotive side, and metal plating industries were used to determine the levels of Cu, Zn, Cr, Pb and Ni by using Flame Atomic Absorption Spectrometer. As a result, highest mean levels of copper in supernatants of plating and textile industries were observed as 377,18 ng ml-1, respectively 103 ng ml-1 lead and 963,6 ng ml-1 nickel in plating industry, 1068,2 ng ml-1 zinc and 14557,1 ng ml-1 chromium in plating and leather industries were determined.

  14. Species redistribution during solidification of nuclear fuel waste metal castings

    Energy Technology Data Exchange (ETDEWEB)

    Naterer, G F; Schneider, G E [Waterloo Univ., ON (Canada)

    1994-12-31

    An enthalpy-based finite element model and a binary system species redistribution model are developed and applied to problems associated with solidification of nuclear fuel waste metal castings. Minimal casting defects such as inhomogeneous solute segregation and cracks are required to prevent container corrosion and radionuclide release. The control-volume-based model accounts for equilibrium solidification for low cooling rates and negligible solid state diffusion for high cooling rates as well as intermediate conditions. Test problems involving nuclear fuel waste castings are investigated and correct limiting cases of species redistribution are observed. (author). 11 refs., 1 tab., 13 figs.

  15. Selective removal/recovery of RCRA metals from waste and process solutions using polymer filtration trademark technology

    International Nuclear Information System (INIS)

    Smith, B.F.

    1997-01-01

    Resource Conservation and Recovery Act (RCRA) metals are found in a number of process and waste streams at many DOE, U.S. Department of Defense, and industrial facilities. RCRA metals consist principally of chromium, mercury, cadmium, lead, and silver. Arsenic and selenium, which form oxyanions, are also considered RCRA elements. Discharge limits for each of these metals are based on toxicity and dictated by state and federal regulations (e.g., drinking water, RCRA, etc.). RCRA metals are used in many current operations, are generated in decontamination and decommissioning (D ampersand D) operations, and are also present in old process wastes that require treatment and stabilization. These metals can exist in solutions, as part of sludges, or as contaminants on soils or solid surfaces, as individual metals or as mixtures with other metals, mixtures with radioactive metals such as actinides (defined as mixed waste), or as mixtures with a variety of inert metals such as calcium and sodium. The authors have successfully completed a preliminary proof-of-principle evaluation of Polymer Filtration trademark (PF) technology for the dissolution of metallic mercury and have also shown that they can remove and concentrate RCRA metals from dilute solutions for a variety of aqueous solution types using PF technology. Another application successfully demonstrated is the dilute metal removal of americium and plutonium from process streams. This application was used to remove the total alpha contamination to below 30 pCi/L for the wastewater treatment plant at TA-50 at Los Alamos National Laboratory (LANL) and from nitric acid distillate in the acid recovery process at TA-55, the Plutonium Facility at LANL (ESP-CP TTP AL16C322). This project will develop and optimize the PF technology for specific DOE process streams containing RCRA metals and coordinate it with the needs of the commercial sector to ensure that technology transfer occurs

  16. Selective removal/recovery of RCRA metals from waste and process solutions using polymer filtration{trademark} technology

    Energy Technology Data Exchange (ETDEWEB)

    Smith, B.F. [Los Alamos National Lab., NM (United States)

    1997-10-01

    Resource Conservation and Recovery Act (RCRA) metals are found in a number of process and waste streams at many DOE, U.S. Department of Defense, and industrial facilities. RCRA metals consist principally of chromium, mercury, cadmium, lead, and silver. Arsenic and selenium, which form oxyanions, are also considered RCRA elements. Discharge limits for each of these metals are based on toxicity and dictated by state and federal regulations (e.g., drinking water, RCRA, etc.). RCRA metals are used in many current operations, are generated in decontamination and decommissioning (D&D) operations, and are also present in old process wastes that require treatment and stabilization. These metals can exist in solutions, as part of sludges, or as contaminants on soils or solid surfaces, as individual metals or as mixtures with other metals, mixtures with radioactive metals such as actinides (defined as mixed waste), or as mixtures with a variety of inert metals such as calcium and sodium. The authors have successfully completed a preliminary proof-of-principle evaluation of Polymer Filtration{trademark} (PF) technology for the dissolution of metallic mercury and have also shown that they can remove and concentrate RCRA metals from dilute solutions for a variety of aqueous solution types using PF technology. Another application successfully demonstrated is the dilute metal removal of americium and plutonium from process streams. This application was used to remove the total alpha contamination to below 30 pCi/L for the wastewater treatment plant at TA-50 at Los Alamos National Laboratory (LANL) and from nitric acid distillate in the acid recovery process at TA-55, the Plutonium Facility at LANL (ESP-CP TTP AL16C322). This project will develop and optimize the PF technology for specific DOE process streams containing RCRA metals and coordinate it with the needs of the commercial sector to ensure that technology transfer occurs.

  17. Fluidized-bed-combustion ash for the solidification and stabilization of a metal-hydroxide sludge.

    Science.gov (United States)

    Knoll, K L; Behr-Andres, C

    1998-01-01

    Fluidized-bed-combustion (FBC) ash is a by-product from a developing technology for coal-fired power plants that will economically reduce air emissions to meet requirements of the Clean Air Act. FBC ash has physical and chemical properties similar to Portland cement, but only has moderate success as a pozzolan in concrete applications due to low compressive strengths. However, FBC ash has proven effective for use as a binder for the solidification and stabilization (S/S) of metal-bearing sludges. Physical and chemical characterization procedures were used to analyze FBC ash and a metal-bearing sludge obtained from a hazardous waste treatment facility to develop 12 different S/S mix designs. The mix designs consist of four binder designs to evaluate sludge-to-binder ratios of approximately 0, 0.5, and 1. Portland cement is used as a control binder to compare unconfined compressive strengths and Toxicity Characteristic Leaching Procedure (TCLP) analyses from different ratios of the FBC ash streams: fly ash, char, and spent bed material (SBM). Compressive strengths ranging from 84 lbs per square inch (psi) to 298 psi were obtained from various mix designs containing different sludge-to-ash ratios cured for 28 days. All the mix designs passed the TCLP. Recoveries from leaching for each metal were less than 5% for most mix designs. Results of unconfined compressive strengths, TCLP, and percent recovery calculations indicate that the mix design containing approximately a 1:1 ratio of fly ash to char-and-sludge is the best mix design for the S/S of the metal-bearing sludge.

  18. Selective chelation-supercritical fluid extraction of metal ions from waste materials

    International Nuclear Information System (INIS)

    Wai, C.N.; Laintz, K.E.; Yonker, C.R.

    1993-01-01

    The removal of toxic organics, metals, and radioisotopes from solids or liquids is a major concern in the treatment of industrial and nuclear wastes. For this reason, developing methods for selective separation of toxic metals and radioactive materials from solutions of complex matrix is an important problem in environmental research. Recent developments indicate supercritical fluids are good solvents for organic compounds. Many gases become supercritical fluids under moderate temperatures and pressures. For example, the critical temperature and pressure of carbon dioxide are 31 degrees C and 73 atm, respectively. The high diffusivity, low viscosity, and T-P dependence of solvent strength are some attractive properties of supercritical fluid extraction (SFE). Since CO 2 offers the additional benefits of stability and non-toxicity, the SFE technique avoids generation of organic liquid waste and exposure of personnel to toxic solvents. While direct extraction of metal ions by supercritical fluids is highly inefficient, these ions when complexed with organic ligands become quite soluble in supercritical fluids. Specific ligands can be used to achieve selective extraction of metal ions in this process. After SFE, the fluid phase can be depressurized for precipitation of the metal chelates and recycled. The ligand can also be regenerated for repeated use. The success of this selective chelation-supercritical fluid extraction (SC-SFE) process depends on a number of factors including the efficiencies of the selective chelating agents, solubilities of metal chelates in supercritical fluids, rate of extraction, ease of regeneration of the ligands, etc. In this report, the authors present recent results on the studies of the solubilities of metal chelates in supercritical CO 2 , experimental ions from aqueous solution, and the development of selective chelating agents (ionizable crown ethers) for the extraction of lanthanides and actinides

  19. Evaluation of physical, chemical and heavy metal concentration of food waste composting

    Directory of Open Access Journals (Sweden)

    Abdul Kadir Aeslina

    2017-01-01

    Full Text Available In this study, food waste composting with rice husk and coconut fibre as compost medium were carried out. Two types of different fermentation liquids were prepared which were fermented liquid (banana peel and fermented liquid from fermented soybeans. During the composting process, a compost samples for a twenty week duration at an interval time of two weeks. Among the physico-chemical parameters that were tested were temperature, moisture content, pH value, Total Nitrogen, Total Phosphorous, Potassium and Total Organic Carbon and Carbon Nitrogen ratio. Heavy metals such as copper, cadmium, lead, nickel and arsenic were observed and analysed. From this study, it was found that, the temperature increased during the thermophilic phase while there was gradually increase of Total Nitrogen, Total Phosphorous and Potassium from the beginning till the end of the composting process. It was also found that the total organic carbon (TOC and the carbon nitrogen ratio decreased significantly during the decomposition process. Traces amounts of heavy metals were also detected and remains below the standard Malaysian Environmental regulations. It was concluded that, the composting process was faster with processed food waste followed by combination of processed food waste and raw. Raw food waste were demonstrated the lowest degradation rate.

  20. Effect of calcium hydroxide application to feedlot pen surface material on ammonia, odor, and greenhouse gas emissions

    Science.gov (United States)

    Calcium hydroxide (lime) is used to reduce microorganisms and odors in human biosolids, animal and poultry manures, and abattoir wastes. In the cattle industry, lime has been used as a disinfectant and is spread on the pen surface to control infections such as diarrhea and foot rot. The increase in ...

  1. Method and apparatus for the production of metal oxide powder

    Science.gov (United States)

    Harris, M.T.; Scott, T.C.; Byers, C.H.

    1992-06-16

    The present invention provides a method for preparing metal oxide powder. A first solution, which is substantially organic, is prepared. A second solution, which is an aqueous solution substantially immiscible in the first solution, is prepared and delivered as drops to the first solution. The drops of the second solution are atomized by a pulsed electric field forming micro-drops of the second solution. Reagents in the first solution diffuse into and react with reactants in the micro-drops of the second solution forming metal hydroxide or oxalate particles. The metal hydroxide or metal oxalate particles are then recovered and dried to produce the metal oxide powder. An apparatus for preparing a metal oxide powder is also disclosed. 2 figs.

  2. Equilibrium leach tests with cobalt in the system cemented waste form/container material/aqueous solution

    International Nuclear Information System (INIS)

    Vejmelka, P.; Koester, R.; Lee, M. J.; Han, K. W.

    1991-01-01

    The equilibrium concentrations of Co in the system of cemented waste form/aqueous solutions were determined including the effect of the container material and its corrosion products under the respective conditions. The chemical conditions in the near field of the waste form were characterized by measurement of the pH and E h value. As disposal relevant solutions, saturated sodium chloride, Q-brine (main constituent MgCl 2 ) and a granitic type groundwater were used. For comparison, also experiments using deionized water were performed. In all systems investigated the cemented waste form itself has a strong influence on the chemical conditions in the near field. The pH and E h values are affected in all cases by the addition of the cemented waste form. There is no or only a slight difference between the E h values if iron powder or iron hydroxide is added to the cemented waste form/solution systems, but the E h is markedly decreased when iron powder is added to the solution free of cement. The Co concentration is decreased in all solutions by the addition of the cemented waste form, the largest effect is observed in Q-brine and this can be attributed either to the sorption of the Co-ions on the corrosion products of the cement or to the coprecipitation of Co-hydroxide and Mg-hydroxide. In the other solutions the Co concentration is decreased by precipitation of Co-hydroxide due to the high pH value of 12.5, and the concentrations are comparable for the different solutions

  3. Ionic Strength-Controlled Mn (Hydr)oxide Nanoparticle Nucleation on Quartz: Effect of Aqueous Mn(OH)2.

    Science.gov (United States)

    Jung, Haesung; Jun, Young-Shin

    2016-01-05

    The early formation of manganese (hydr)oxide nanoparticles at mineral-water interfaces is crucial in understanding how Mn oxides control the fate and transport of heavy metals and the cycling of nutrients. Using atomic force microscopy, we investigated the heterogeneous nucleation and growth of Mn (hydr)oxide under varied ionic strengths (IS; 1-100 mM NaNO3). Experimental conditions (i.e., 0.1 mM Mn(2+) (aq) concentration and pH 10.1) were chosen to be relevant to Mn remediation sites. We found that IS controls Mn(OH)2 (aq) formation, and that the controlled Mn(OH)2 (aq) formation can affect the system's saturation and subsequent Mn(OH)2 (s) and further Mn3O4 (s) nanoparticle formation. In 100 mM IS system, nucleated Mn (hydr)oxide particles had more coverage on the quartz substrate than those in 1 mM and 10 mM IS systems. This high IS also resulted in low supersaturation ratio and thus favor heterogeneous nucleation, having better structural matching between nucleating Mn (hydr)oxides and quartz. The unique information obtained in this work improves our understanding of Mn (hydr)oxide formation in natural as well as engineered aqueous environments, such as groundwater contaminated by natural leachate and acid mine drainage remediation.

  4. Preparation of magnesium hydroxide nanoflowers from boron mud via anti-drop precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Xi [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Blue Sky Technology Corporation, Beijing 100083 (China); Ma, Hongwen, E-mail: mahw@cugb.edu.cn [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Jiang, Xiaoqian [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Jiang, Zhouqing [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Blue Sky Technology Corporation, Beijing 100083 (China)

    2014-08-15

    Highlights: • We use the anti-drop precipitation method for synthesis of magnesium hydroxide. • Boron mud which is solid waste from a borax factory is used as the magnesium source. • The magnesium hydroxide nanoflowers are prepared in a short time. • The as-prepared magnesium hydroxide can be used as an effective flame retardant. - Abstract: Using boron mud as the starting material, the flower-like magnesium hydroxide (MH) has been successfully prepared via anti-drop precipitation method. The effect of NH{sub 3}·H{sub 2}O concentration, aging time, and surfactant on the morphology of MH was investigated. The optimum precipitation conditions are dropping MgSO{sub 4} solution in 5% NH{sub 3}·H{sub 2}O solution, with 3% polyethylene glycol as surfactant, aging for 30 min. XRD, SEM, FI-IR, and TG/DTA have been employed to characterize the as-prepared samples. XRD reveals that MH with high purity has the brucite structure. SEM images show that the flower-like MH exists in the form of mono-disperse well uniform spherical aggregation with diameter of 3–5 μm. TG/DTA shows a total percentage of weight loss 33.6% with a well-defined endothermic peak near 381.3 °C corresponding to the decomposition of MH. Furthermore, it reports that the extremely fast primary nucleation is of significance for crystal growth of MH.

  5. Inhibition of acid mine drainage and immobilization of heavy metals from copper flotation tailings using a marble cutting waste

    Science.gov (United States)

    Tozsin, Gulsen

    2016-01-01

    Acid mine drainage (AMD) with high concentrations of sulfates and metals is generated by the oxidation of sulfide bearing wastes. CaCO3-rich marble cutting waste is a residual material produced by the cutting and polishing of marble stone. In this study, the feasibility of using the marble cutting waste as an acid-neutralizing agent to inhibit AMD and immobilize heavy metals from copper flotation tailings (sulfide- bearing wastes) was investigated. Continuous-stirring shake-flask tests were conducted for 40 d, and the pH value, sulfate content, and dissolved metal content of the leachate were analyzed every 10 d to determine the effectiveness of the marble cutting waste as an acid neutralizer. For comparison, CaCO3 was also used as a neutralizing agent. The average pH value of the leachate was 2.1 at the beginning of the experiment ( t = 0). In the experiment employing the marble cutting waste, the pH value of the leachate changed from 6.5 to 7.8, and the sulfate and iron concentrations decreased from 4558 to 838 mg/L and from 536 to 0.01 mg/L, respectively, after 40 d. The marble cutting waste also removed more than 80wt% of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) from AMD generated by copper flotation tailings.

  6. Review of the synthesis of layered double hydroxides: a thermodynamic approach

    Directory of Open Access Journals (Sweden)

    Bravo-Suárez Juan J.

    2004-01-01

    Full Text Available The synthesis of layered double hydroxides (LDHs by hydrothermal-LDH reconstruction and coprecipitation methods is reviewed using a thermodynamic approach. A mixture model was used for the estimation of the thermodynamics of formation of LDHs. The synthesis and solubility of LDHs are discussed in terms of standard molar Gibbs free energy change of reaction. Data for numerous divalent and trivalent metals as well as for some monovalent and tetravalent metals that may be part of the LDH structure have been compiled. Good agreement is found between theoretical and experimental data. Diagrams and tables for the prediction of possible new LDH materials are provided.

  7. DOUBLE SHELL TANK INTEGRITY PROJECT HIGH LEVEL WASTE CHEMISTRY OPTIMIZATION

    International Nuclear Information System (INIS)

    WASHENFELDER DJ

    2008-01-01

    The U.S. Department of Energy's Office (DOE) of River Protection (ORP) has a continuing program for chemical optimization to better characterize corrosion behavior of High-Level Waste (HLW). The DOE controls the chemistry in its HLW to minimize the propensity of localized corrosion, such as pitting, and stress corrosion cracking (SCC) in nitrate-containing solutions. By improving the control of localized corrosion and SCC, the ORP can increase the life of the Double-Shell Tank (DST) carbon steel structural components and reduce overall mission costs. The carbon steel tanks at the Hanford Site are critical to the mission of safely managing stored HLW until it can be treated for disposal. The DOE has historically used additions of sodium hydroxide to retard corrosion processes in HLW tanks. This also increases the amount of waste to be treated. The reactions with carbon dioxide from the air and solid chemical species in the tank continually deplete the hydroxide ion concentration, which then requires continued additions. The DOE can reduce overall costs for caustic addition and treatment of waste, and more effectively utilize waste storage capacity by minimizing these chemical additions. Hydroxide addition is a means to control localized and stress corrosion cracking in carbon steel by providing a passive environment. The exact mechanism that causes nitrate to drive the corrosion process is not yet clear. The SCC is less of a concern in the newer stress relieved double shell tanks due to reduced residual stress. The optimization of waste chemistry will further reduce the propensity for SCC. The corrosion testing performed to optimize waste chemistry included cyclic potentiodynamic volarization studies. slow strain rate tests. and stress intensity factor/crack growth rate determinations. Laboratory experimental evidence suggests that nitrite is a highly effective:inhibitor for pitting and SCC in alkaline nitrate environments. Revision of the corrosion control

  8. Assessing metal contamination from construction and demolition (C&D) waste used to infill wetlands: using Deroceras reticulatum (Mollusca: Gastropoda).

    Science.gov (United States)

    Staunton, John A; Mc Donnell, Rory J; Gormally, Michael J; Williams, Chris D; Henry, Tiernan; Morrison, Liam

    2014-11-01

    Large quantities of construction and demolition waste (C&D) are produced globally every year, with little known about potential environmental impacts. In the present study, the slug, Deroceras reticulatum (Mollusca: Gastropoda) was used as the first biomonitor of metals (Ag, As, Ba, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Se, Ti, Tl, V and Zn) on wetlands post infilling with construction and demolition (C&D) waste. The bioaccumulation of As, Ba, Cd, Co, Sb, Se and Tl were found to be significantly elevated in slugs collected on C&D waste when compared to unimproved pastures (control sites), while Mo, Se and Sr had significantly higher concentrations in slugs collected on C&D waste when compared to known contaminated sites (mining locations), indicating the potential hazardous nature of C&D waste to biota. Identifying exact sources for these metals within the waste can be problematic, due to its heterogenic nature. Biomonitors are a useful tool for future monitoring and impact studies, facilitating policy makers and regulations in other countries regarding C&D waste infill. In addition, improving separation of C&D waste to allow increased reuse and recycling is likely to be effective in reducing the volume of waste being used as infill, subsequently decreasing potential metal contamination.

  9. Development of Ceramic Coating on Metal Substrate using Industrial Waste and Ore Minerals

    Science.gov (United States)

    Bhuyan, S. K.; Thiyagarajan, T. K.; Mishra, S. C.

    2017-02-01

    The technological advancement in modern era has a boon for enlightening human life; but also is a bane to produce a huge amount of (industrial) wastes, which is of great concern for utilization and not to create environmental threats viz. polution etc. In the present piece of research work, attempts have been made to utilize fly ash (wastes of thermal power plants) and along with alumina bearing ore i.e. bauxite, for developing plasma spray ceramic coatings on metals. Fly ash and with 10 and 20% bauxite addition is used to deposit plasma spray coatings on a metal substrate. The surface morphology of the coatings deposited at different power levels of plasma spraying investigated through SEM and EDS analysis. The coating thickness is measured. The porosity levels of the coatings are evaluated. The coating hardness isalso measured. This piece of research work will be beneficial for future development and use of industrial waste and ore minerals for high-valued applications.

  10. Radioactive waste processing device

    International Nuclear Information System (INIS)

    Ikeda, Takashi; Funabashi, Kiyomi; Chino, Koichi.

    1992-01-01

    In a waste processing device for solidifying, pellets formed by condensing radioactive liquid wastes generated from a nuclear power plant, by using a solidification agent, sodium chloride, sodium hydroxide or sodium nitrate is mixed upon solidification. In particular, since sodium sulfate in a resin regenerating liquid wastes absorbs water in the cement upon cement solidification, and increases the volume by expansion, there is a worry of breaking the cement solidification products. This reaction can be prevented by the addition of sodium chloride and the like. Accordingly, integrity of the solidification products can be maintained for a long period of time. (T.M.)

  11. Application of fuel cell for pyrite and heavy metal containing mining waste

    Science.gov (United States)

    Keum, H.; Ju, W. J.; Jho, E. H.; Nam, K.

    2015-12-01

    Once pyrite and heavy metal containing mining waste reacts with water and air it produces acid mine drainage (AMD) and leads to the other environmental problems such as contamination of surrounding soils. Pyrite is the major source of AMD and it can be controlled using a biological-electrochemical dissolution method. By enhancing the dissolution of pyrite using fuel cell technology, not only mining waste be beneficially utilized but also be treated at the same time by. As pyrite-containing mining waste is oxidized in the anode of the fuel cell, electrons and protons are generated, and electrons moves through an external load to cathode reducing oxygen to water while protons migrate to cathode through a proton exchange membrane. Iron-oxidizing bacteria such as Acidithiobacillus ferrooxidans, which can utilize Fe as an electron donor promotes pyrite dissolution and hence enhances electrochemical dissolution of pyrite from mining waste. In this study mining waste from a zinc mine in Korea containing 17 wt% pyrite and 9% As was utilized as a fuel for the fuel cell inoculated with A. ferrooxidans. Electrochemically dissolved As content and chemically dissolved As content was compared. With the initial pH of 3.5 at 23℃, the dissolved As concentration increased (from 4.0 to 13 mg/L after 20 d) in the fuel cell, while it kept decreased in the chemical reactor (from 12 to 0.43 mg/L after 20 d). The fuel cell produced 0.09 V of open circuit voltage with the maximum power density of 0.84 mW/m2. Dissolution of As from mining waste was enhanced through electrochemical reaction. Application of fuel cell technology is a novel treatment method for pyrite and heavy metals containing mining waste, and this method is beneficial for mining environment as well as local community of mining areas.

  12. Metal mobilization from metallurgical wastes by soil organic acids.

    Science.gov (United States)

    Potysz, Anna; Grybos, Malgorzata; Kierczak, Jakub; Guibaud, Gilles; Fondaneche, Patrice; Lens, Piet N L; van Hullebusch, Eric D

    2017-07-01

    Three types of Cu-slags differing in chemical and mineralogical composition (historical, shaft furnace, and granulated slags) and a matte from a lead recovery process were studied with respect to their susceptibility to release Cu, Zn and Pb upon exposure to organic acids commonly encountered in soil environments. Leaching experiments (24-960 h) were conducted with: i) humic acid (20 mg/L) at pH t 0  = 4.4, ii) fulvic acid (20 mg/L) at pH t 0  = 4.4, iii) an artificial root exudates (ARE) (17.4 g/L) solution at pH t 0  = 4.4, iv) ARE solution at pH t 0  = 2.9 and v) ultrapure water (pH t 0  = 5.6). The results demonstrated that the ARE contribute the most to the mobilization of metals from all the wastes analyzed, regardless of the initial pH of the solution. For example, up to 14%, 30%, 24% and 5% of Cu is released within 960 h from historical, shaft furnace, granulated slags and lead matte, respectively, when exposed to the artificial root exudates solution (pH 2.9). Humic and fulvic acids were found to have a higher impact on granulated and shaft furnace slags as compared to the ultrapure water control and increased the release of metals by a factor up to 37.5 (Pb) and 20.5 (Cu) for granulated and shaft furnace slags, respectively. Humic and fulvic acids amplified the mobilization of metals by a maximal factor of 13.6 (Pb) and 12.1 (Pb) for historical slag and lead matte, respectively. The studied organic compounds contributed to different release rates of metallic contaminants from individual metallurgical wastes under the conditions tested. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Activity targets for nanostructured platinum-group-metal-free catalysts in hydroxide exchange membrane fuel cells

    Science.gov (United States)

    Setzler, Brian P.; Zhuang, Zhongbin; Wittkopf, Jarrid A.; Yan, Yushan

    2016-12-01

    Fuel cells are the zero-emission automotive power source that best preserves the advantages of gasoline automobiles: low upfront cost, long driving range and fast refuelling. To make fuel-cell cars a reality, the US Department of Energy has set a fuel cell system cost target of US$30 kW-1 in the long-term, which equates to US$2,400 per vehicle, excluding several major powertrain components (in comparison, a basic, but complete, internal combustion engine system costs approximately US$3,000). To date, most research for automotive applications has focused on proton exchange membrane fuel cells (PEMFCs), because these systems have demonstrated the highest power density. Recently, however, an alternative technology, hydroxide exchange membrane fuel cells (HEMFCs), has gained significant attention, because of the possibility to use stable platinum-group-metal-free catalysts, with inherent, long-term cost advantages. In this Perspective, we discuss the cost profile of PEMFCs and the advantages offered by HEMFCs. In particular, we discuss catalyst development needs for HEMFCs and set catalyst activity targets to achieve performance parity with state-of-the-art automotive PEMFCs. Meeting these targets requires careful optimization of nanostructures to pack high surface areas into a small volume, while maintaining high area-specific activity and favourable pore-transport properties.

  14. Evaluation of permeability and swelling pressure of compacted bentonite using a calcium hydroxide solution

    International Nuclear Information System (INIS)

    Aoyagi, Takayoshi; Maeda, Munehiro; Mihara, Morihiro; Tanaka, Masuhiro

    1998-12-01

    Tests to determine the swelling pressure, permeability, compressive strength and elastic modulus of Ca-Na exchanged bentonite, Na-bentonite and Ca-bentonite at the Power Reactor and Nuclear Fuel Development Corporation have mainly used distilled water. However, disposal facilities for TRU waste will use cementateous material for packaging, backfill as well as structural support. In this case, a large amount of calcium will dissolve in groundwater flowing through the cementateous material. Therefore, it is important to investigate the mechanical properties of bentonite in calcium-rich water as part of the disposal research program for TRU waste. In order to understand the effect of the chemical composition of water on the basic mechanical properties of bentonite - part of evaluating the disposal concepts for TRU waste disposal - we tested the permeability of compacted bentonite under saturated conditions using a calcium hydroxide solution. The aqueous solution represents water dominated by the calcium component. Na-bentonite, Ca-Na exchanged bentonite and Ca-bentonite were used for swelling pressure measurement tests and permeability testing. Measures of the maximum and equilibrium swelling pressure as well as permeability we obtained. The dry density of bentonite was varied between tests. Results show that swelling pressure and permeability are dependent on dry density. In separate tests using Ca-bentonite, the bentonite-mixing rate was varied as an independent parameter. Results show that there is little change in the swelling pressure and permeability between tests using calcium hydroxide solution and distilled water for all bentonite types. (author)

  15. Design of an innovative, ecological portable waste compressor for in-house recycling of paper, plastic and metal packaging waste.

    Science.gov (United States)

    Xevgenos, D; Athanasopoulos, N; Kostazos, P K; Manolakos, D E; Moustakas, K; Malamis, D; Loizidou, M

    2015-05-01

    Waste management in Greece relies heavily on unsustainable waste practices (mainly landfills and in certain cases uncontrolled dumping of untreated waste). Even though major improvements have been achieved in the recycling of municipal solid waste during recent years, there are some barriers that hinder the achievement of high recycling rates. Source separation of municipal solid waste has been recognised as a promising solution to produce high-quality recycled materials that can be easily directed to secondary materials markets. This article presents an innovative miniature waste separator/compressor that has been designed and developed for the source separation of municipal solid waste at a household level. The design of the system is in line with the Waste Framework Directive (2008/98/EC), since it allows for the separate collection (and compression) of municipal solid waste, namely: plastic (polyethylene terephthalate and high-density polyethylene), paper (cardboard and Tetrapak) and metal (aluminium and tin cans). It has been designed through the use of suitable software tools (LS-DYNA, INVENTROR and COMSOL). The results from the simulations, as well as the whole design process and philosophy, are discussed in this article. © The Author(s) 2015.

  16. Poly I-lactide-layered double hydroxide nanocomposites via in situ polymerization of I-lactide

    DEFF Research Database (Denmark)

    Katiyar, Vimal; Gerds, N.; Koch, C.B.

    2010-01-01

    The use of clay nanofillers offers a potential route to improved barrier properties in polylactide films. Magnesium–aluminium layered double hydroxides (LDHs) are interesting in this respect and we therefore explored synthesis of PLA-LDH nanocomposites by ring-opening polymerization. This method ...... weight was significantly reduced when in-situ polymerization was conducted in the presence of the LDHs and we suggest that chain termination via LDH surface hydroxyl groups and/or metal-catalyzed degradation could be responsible.......The use of clay nanofillers offers a potential route to improved barrier properties in polylactide films. Magnesium–aluminium layered double hydroxides (LDHs) are interesting in this respect and we therefore explored synthesis of PLA-LDH nanocomposites by ring-opening polymerization. This method...

  17. Separation and Extraction of Some Heavy and Toxic Metal Ions from Their Wastes by Ionic Membranes

    International Nuclear Information System (INIS)

    El-Sayed Hegazy, A.; Kamal, H.; Mahmoud, Gh. A.; Khalifa, N.A.

    1999-01-01

    Preparation and characterisation of a series of ion-exchange membranes for the purpose of separation and extraction of some heavy and toxic metal ions from their wastes have been studied. Such ion exchange membranes prepared by γ-radiation grafting of acrylonitrile (AN) and vinyl acetate (VAc) in a binary monomers mixture onto low density polyethylene (LDPE) using direct technique of grafting. The reaction conditions at which grafting process proceeds successfully have been determined. Many modification treatments have been attempted for the prepared membranes to improve their ion-exchange properties. The possibility of their practical use in waste water treatment from some heavy and toxic metal ions such as Pb 2+ , Cd 2+ ,Cu 2+ ,Fe 3+ ,Sr 2+ and Li + have been investigated. These grafted membranes showed great promise for its use in the field of extraction and removal of some heavy and toxic metals from their wastes

  18. Change of heavy metal speciation, mobility, bioavailability, and ecological risk during potassium ferrate treatment of waste-activated sludge.

    Science.gov (United States)

    Yu, Ming; Zhang, Jian; Tian, Yu

    2018-05-01

    The effects of potassium ferrate treatment on the heavy metal concentrations, speciation, mobility, bioavailability, and environmental risk in waste-activated sludge (WAS) at various dosages of potassium ferrate and different treatment times were investigated. Results showed that the total concentrations of all metals (except Cd) were decreased slightly after treatment and the order of metal concentrations in WAS and treated waste-activated sludge (TWAS) was Mg > Zn > Cu > Cr > Pb > Ni > Cd. Most heavy metals in WAS remained in TWAS after potassium ferrate treatment with metal residual rates over 67.8% in TWAS. The distribution of metal speciation in WAS was affected by potassium ferrate treatment. The bioavailability and the mobility of heavy metals (except Mg) in TWAS were mitigated, compared to those in WAS. Meanwhile, the environmental risk of heavy metals (except Pb and Cu) was alleviated after potassium ferrate treatment.

  19. Enhanced selective metal adsorption on optimised agroforestry waste mixtures.

    Science.gov (United States)

    Rosales, Emilio; Ferreira, Laura; Sanromán, M Ángeles; Tavares, Teresa; Pazos, Marta

    2015-04-01

    The aim of this work is to ascertain the potentials of different agroforestry wastes to be used as biosorbents in the removal of a mixture of heavy metals. Fern (FE), rice husk (RI) and oak leaves (OA) presented the best removal percentages for Cu(II) and Ni(II), Mn(II) and Zn(II) and Cr(VI), respectively. The performance of a mixture of these three biosorbents was evaluated, and an improvement of 10% in the overall removal was obtained (19.25mg/g). The optimum mixture proportions were determined using simplex-centroid mixture design method (FE:OA:RI=50:13.7:36.3). The adsorption kinetics and isotherms of the optimised mixture were fit by the pseudo-first order kinetic model and Langmuir isotherm. The adsorption mechanism was studied, and the effects of the carboxylic, hydroxyl and phenolic groups on metal-biomass binding were demonstrated. Finally, the recoveries of the metals using biomass were investigated, and cationic metal recoveries of 100% were achieved when acidic solutions were used. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Variation and distribution of metals and metalloids in soil/ash mixtures from Agbogbloshie e-waste recycling site in Accra, Ghana.

    Science.gov (United States)

    Itai, Takaaki; Otsuka, Masanari; Asante, Kwadwo Ansong; Muto, Mamoru; Opoku-Ankomah, Yaw; Ansa-Asare, Osmund Duodu; Tanabe, Shinsuke

    2014-02-01

    Illegal import and improper recycling of electronic waste (e-waste) are an environmental issue in developing countries around the world. African countries are no exception to this problem and the Agbogbloshie market in Accra, Ghana is a well-known e-waste recycling site. We have studied the levels of metal(loid)s in the mixtures of residual ash, formed by the burning of e-waste, and the cover soil, obtained using a portable X-ray fluorescence spectrometer (P-XRF) coupled with determination of the 1M HCl-extractable fraction by an inductively coupled plasma mass spectrometer. The accuracy and precision of the P-XRF measurements were evaluated by measuring 18 standard reference materials; this indicated the acceptable but limited quality of this method as a screening tool. The HCl-extractable levels of Al, Co, Cu, Zn, Cd, In, Sb, Ba, and Pb in 10 soil/ash mixtures varied by more than one order of magnitude. The levels of these metal(loid)s were found to be correlated with the color (i.e., soil/ash ratio), suggesting that they are being released from disposed e-waste via open burning. The source of rare elements could be constrained using correlation to the predominant metals. Human hazard quotient values based on ingestion of soil/ash mixtures exceeded unity for Pb, As, Sb, and Cu in a high-exposure scenario. This study showed that along with common metals, rare metal(loid)s are also enriched in the e-waste burning site. We suggest that risk assessment considering exposure to multiple metal(loid)s should be addressed in studies of e-waste recycling sites. © 2013. Published by Elsevier B.V. All rights reserved.

  1. Volume reducing and modifying of neutralized sludge from acid waste water treatment of uranium ore heap leaching

    International Nuclear Information System (INIS)

    Zhong Pingru; Ding Tongsen; Gu Jianghan

    1997-01-01

    A process is worked out on the basis of traditional lime neutralization, viz. acid waste water from uranium ore heap leaching is treated by limestone and lime double neutralizing-sludge recycling. First, the waste water is reacted with cheaper limestone to precipitate some metal ions, such as Fe and Al, which form hydroxides at lower pH, and neutralize strong acid, then neutralized with lime to required pH value. The formed precipitate as sludge is steadily recycled in the process. The principal advantage of the process over lime neutralization process is that reagent cost saved by 1/3 and formed sludge volume decreased by 2/3. Besides, the performances of sludge filtrating and settling are improved. The mechanism of sludge volume reducing and modification is also investigated

  2. Dissolution mechanism of aluminum hydroxides in acid media

    Science.gov (United States)

    Lainer, Yu. A.; Gorichev, I. G.; Tuzhilin, A. S.; Gololobova, E. G.

    2008-08-01

    The effects of the concentration, temperature, and potential at the hydroxide/electrolyte interface on the aluminum hydroxide dissolution in sulfuric, hydrochloric, and perchloric acids are studied. The limiting stage of the aluminum hydroxide dissolution in the acids is found to be the transition of the complexes that form on the aluminum hydroxide surface from the solid phase into the solution. The results of the calculation of the acid-base equilibrium constants at the oxide (hydroxide)/solution interface using the experimental data on the potentiometric titration of Al2O3 and AlOOH suspensions are analyzed. A mechanism is proposed for the dissolution of aluminum hydroxides in acid media.

  3. Evaluation of extractant-coated magnetic microparticles for the recovery of hazardous metals from waste solution

    International Nuclear Information System (INIS)

    Kaminski, M. D.

    1998-01-01

    A magnetically assisted chemical separation (MACS) process was developed earlier at Argonne National Laboratory (ANL). This compact process was designed for the separation of transuranics (TRU) and radionuclides from the liquid waste streams that exist at many DOE sites, with an overall reduction in waste volume requiring disposal. The MACS process combines the selectivity afforded by solvent extractant/ion exchange materials with magnetic separation to provide an efficient chemical separation. Recently, the MACS process has been evaluated with acidic organophosphorus extractants for hazardous metal recovery from waste solutions. Moreover, process scale-up design issues have been addressed with respect to particle filtration and recovery. Two acidic organophosphorus compounds have been investigated for hazardous metal recovery, bis(2,4,4-trimethylpentyl) phosphinic acid (Cyanexreg-sign 272) and bis(2,4,4-trimethylpentyl) dithiophosphinic acid (Cyanexreg-sign 301). Coated onto magnetic microparticles, these extractants demonstrated superior recovery of hazardous metals from solution, relative to what was expected on the basis of results from solvent extraction experiments. The results illustrate the diverse applications of MACS technology for dilute waste streams. Preliminary process scale-up experiments with a high-gradient magnetic separator at Oak Ridge National Laboratory have revealed that very low microparticle loss rates are possible

  4. Heavy metal evaporation kinetics in thermal waste treatment processes

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, Ch; Stucki, S; Schuler, A J [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    To investigate the evaporation kinetics of heavy metals, experiments were performed by conventional thermogravimetry and a new method using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The new method allows online measurements in time intervals that are typically below one minute. The evaporation of Cd, Cu, Pb, and Zn from synthetic mixtures and filter ashes from municipal solid waste incineration (MSWI) was of major interest. (author) 2 figs., 4 refs.

  5. Recycling of Metal Containing Waste by Liquid-Liquid Extraction

    International Nuclear Information System (INIS)

    Reinhardt, H.

    1999-01-01

    Through the years, a large number of liquid-liquid extraction have been proposed for metal waste recovery and recycling(1,2). However, few of them have achieved commercial application. In fact, relatively little information is available on practical operation and economic feasibility. This presentation will give complementary information by describing and comparing three processes, based on the Am MAR hydrometallurgical concept and representing three different modes of operation

  6. Grout formulation for disposal of low-level and hazardous waste streams containing fluoride

    Science.gov (United States)

    McDaniel, E.W.; Sams, T.L.; Tallent, O.K.

    1987-06-02

    A composition and related process for disposal of hazardous waste streams containing fluoride in cement-based materials is disclosed. the presence of fluoride in cement-based materials is disclosed. The presence of fluoride in waste materials acts as a set retarder and as a result, prevents cement-based grouts from setting. This problem is overcome by the present invention wherein calcium hydroxide is incorporated into the dry-solid portion of the grout mix. The calcium hydroxide renders the fluoride insoluble, allowing the grout to set up and immobilize all hazardous constituents of concern. 4 tabs.

  7. Selective extraction and recovery of rare earth metals from phosphor powders in waste fluorescent lamps using an ionic liquid system

    International Nuclear Information System (INIS)

    Yang, Fan; Kubota, Fukiko; Baba, Yuzo; Kamiya, Noriho; Goto, Masahiro

    2013-01-01

    Highlights: • Recycling of rare earth metals from fluorescent lamps was conducted by ionic liquid-mediated extraction. • Acid leaching from a waste phosphor powder was carried out using sulfuric and nitric acids. • An ionic liquid was used as extracting solvent for the rare earth metals. • Selective extraction of rare earth metals from leach solutions was attained. •The extracting ionic liquid phase was recyclable in the recovery process. -- Abstract: The recycling of rare earth metals from phosphor powders in waste fluorescent lamps by solvent extraction using ionic liquids was studied. Acid leaching of rare earth metals from the waste phosphor powder was examined first. Yttrium (Y) and europium (Eu) dissolved readily in the acid solution; however, the leaching of other rare earth metals required substantial energy input. Ionization of target rare earth metals from the waste phosphor powders into the leach solution was critical for their successful recovery. As a high temperature was required for the complete leaching of all rare earth metals, ionic liquids, for which vapor pressure is negligible, were used as an alternative extracting phase to the conventional organic diluent. An extractant, N, N-dioctyldiglycol amic acid (DODGAA), which was recently developed, showed a high affinity for rare earth metal ions in liquid–liquid extraction although a conventional commercial phosphonic extractant did not. An effective recovery of the rare earth metals, Y, Eu, La and Ce, from the metal impurities, Fe, Al and Zn, was achieved from the acidic leach solution of phosphor powders using an ionic liquid containing DODGAA as novel extractant system

  8. Selective extraction and recovery of rare earth metals from phosphor powders in waste fluorescent lamps using an ionic liquid system

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Fan; Kubota, Fukiko; Baba, Yuzo [Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan); Kamiya, Noriho [Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan); Center for Future Chemistry, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan); Goto, Masahiro, E-mail: m-goto@mail.cstm.kyushu-u.ac.jp [Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan); Center for Future Chemistry, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan)

    2013-06-15

    Highlights: • Recycling of rare earth metals from fluorescent lamps was conducted by ionic liquid-mediated extraction. • Acid leaching from a waste phosphor powder was carried out using sulfuric and nitric acids. • An ionic liquid was used as extracting solvent for the rare earth metals. • Selective extraction of rare earth metals from leach solutions was attained. •The extracting ionic liquid phase was recyclable in the recovery process. -- Abstract: The recycling of rare earth metals from phosphor powders in waste fluorescent lamps by solvent extraction using ionic liquids was studied. Acid leaching of rare earth metals from the waste phosphor powder was examined first. Yttrium (Y) and europium (Eu) dissolved readily in the acid solution; however, the leaching of other rare earth metals required substantial energy input. Ionization of target rare earth metals from the waste phosphor powders into the leach solution was critical for their successful recovery. As a high temperature was required for the complete leaching of all rare earth metals, ionic liquids, for which vapor pressure is negligible, were used as an alternative extracting phase to the conventional organic diluent. An extractant, N, N-dioctyldiglycol amic acid (DODGAA), which was recently developed, showed a high affinity for rare earth metal ions in liquid–liquid extraction although a conventional commercial phosphonic extractant did not. An effective recovery of the rare earth metals, Y, Eu, La and Ce, from the metal impurities, Fe, Al and Zn, was achieved from the acidic leach solution of phosphor powders using an ionic liquid containing DODGAA as novel extractant system.

  9. Multistage leaching of metals from spent lithium ion battery waste using electrochemically generated acidic lixiviant.

    Science.gov (United States)

    Boxall, N J; Adamek, N; Cheng, K Y; Haque, N; Bruckard, W; Kaksonen, A H

    2018-04-01

    Lithium ion battery (LIB) waste contains significant valuable resources that could be recovered and reused to manufacture new products. This study aimed to develop an alternative process for extracting metals from LIB waste using acidic solutions generated by electrolysis for leaching. Results showed that solutions generated by electrolysis of 0.5 M NaCl at 8 V with graphite or mixed metal oxide (MMO) electrodes were weakly acidic and leach yields obtained under single stage (batch) leaching were poor (leaching with the graphite electrolyte solution improved leach yields overall, but the electrodes corroded over time. Though yields obtained with both electrolyte leach solutions were low when compared to the 4 M HCl control, there still remains potential to optimise the conditions for the generation of the acidic anolyte solution and the solubilisation of valuable metals from the LIB waste. A preliminary value proposition indicated that the process has the potential to be economically feasible if leach yields can be improved, especially based on the value of recoverable cobalt and lithium. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Removal and recovery of toxic metal ions from aqueous waste sites using polymer pendant ligands

    International Nuclear Information System (INIS)

    Fish, D.

    1996-01-01

    The purpose of this project is to investigate the use of polymer pendant ligand technology to remove and recover toxic metal ions from DOE aqueous waste sites. Polymer pendant lgiands are organic ligands, anchored to crosslinked, modified divinylbenzene-polystyrene beads, that can selectively complex metal ions. The metal ion removal step usually occurs through a complexation or ion exchange phenomena, thus recovery of the metal ions and reuse of the beads is readily accomplished

  11. Reduction of heavy metals in residues from the dismantling of waste electrical and electronic equipment before incineration

    International Nuclear Information System (INIS)

    Long, Yu-Yang; Feng, Yi-Jian; Cai, Si-Shi; Hu, Li-Fang; Shen, Dong-Sheng

    2014-01-01

    Highlights: • The highest metal reduction occurs at a 2.36 mm sieving size. • Washing promotes heavy metal recycling without secondary pollution. • Sieving and washing are environmentally friendly pretreatments for WEEE wastes. - Abstract: Residues disposal from the dismantling of waste electrical and electronic equipment are challenging because of the large waste volumes, degradation-resistance, low density and high heavy metal content. Incineration is advantageous for treating these residues but high heavy metal contents may exist in incinerator input and output streams. We have developed and studied a specialized heavy metal reduction process, which includes sieving and washing for treating residues before incineration. The preferable screen aperture for sieving was found to be 2.36 mm (8 meshes) in this study; using this screen aperture resulted in the removal of approximately 47.2% Cu, 65.9% Zn, 26.5% Pb, 55.4% Ni and 58.8% Cd from the residues. Subsequent washing further reduces the heavy metal content in the residues larger than 2.36 mm, with preferable conditions being 400 rpm rotation speed, 5 min washing duration and liquid-to-solid ratio of 25:1. The highest cumulative removal efficiencies of Cu, Zn, Pb, Ni and Cd after sieving and washing reached 81.1%, 61.4%, 75.8%, 97.2% and 72.7%, respectively. The combined sieving and washing process is environmentally friendly, can be used for the removal of heavy metals from the residues and has benefits in terms of heavy metal recycling

  12. Reduction of heavy metals in residues from the dismantling of waste electrical and electronic equipment before incineration

    Energy Technology Data Exchange (ETDEWEB)

    Long, Yu-Yang; Feng, Yi-Jian; Cai, Si-Shi [Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012 (China); Hu, Li-Fang [College of Quality and Safety Engineering, China Jiliang University, Hangzhou 310018 (China); Shen, Dong-Sheng, E-mail: shends@zju.edu.cn [Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012 (China)

    2014-05-01

    Highlights: • The highest metal reduction occurs at a 2.36 mm sieving size. • Washing promotes heavy metal recycling without secondary pollution. • Sieving and washing are environmentally friendly pretreatments for WEEE wastes. - Abstract: Residues disposal from the dismantling of waste electrical and electronic equipment are challenging because of the large waste volumes, degradation-resistance, low density and high heavy metal content. Incineration is advantageous for treating these residues but high heavy metal contents may exist in incinerator input and output streams. We have developed and studied a specialized heavy metal reduction process, which includes sieving and washing for treating residues before incineration. The preferable screen aperture for sieving was found to be 2.36 mm (8 meshes) in this study; using this screen aperture resulted in the removal of approximately 47.2% Cu, 65.9% Zn, 26.5% Pb, 55.4% Ni and 58.8% Cd from the residues. Subsequent washing further reduces the heavy metal content in the residues larger than 2.36 mm, with preferable conditions being 400 rpm rotation speed, 5 min washing duration and liquid-to-solid ratio of 25:1. The highest cumulative removal efficiencies of Cu, Zn, Pb, Ni and Cd after sieving and washing reached 81.1%, 61.4%, 75.8%, 97.2% and 72.7%, respectively. The combined sieving and washing process is environmentally friendly, can be used for the removal of heavy metals from the residues and has benefits in terms of heavy metal recycling.

  13. Reuse of waste water from high pressure water jet decontamination for reactor decommissioning scrap metal

    International Nuclear Information System (INIS)

    Deng Junxian; Li Xin; Hou Huijuan

    2011-01-01

    For recycle and reuse of reactor decommissioning scrap metal by high pressure water jet decontamination, large quantity of radioactive waste water will be generated. To save the cost of radioactive waste water treatment and to reduce the cost of the scrap decontamination, this part of radioactive waste water should be reused. Most of the radioactivities in the decontamination waste water come from the solid particle in the water. Thus to reuse the waste water, the solid particle in the waster should be removed. Different possible treatment technologies have been investigated. By cost benefit analysis the centrifugal separation technology is selected. (authors)

  14. 21 CFR 73.2326 - Chromium hydroxide green.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Chromium hydroxide green. 73.2326 Section 73.2326... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2326 Chromium hydroxide green. (a) Identity and specifications.The color additive chromium hydroxide green shall conform in identity and specifications to the...

  15. Comparison of Collection Schemes of Municipal Solid Waste Metallic Fraction: The Impacts on Global Warming Potential for the Case of the Helsinki Metropolitan Area, Finland

    Directory of Open Access Journals (Sweden)

    Kari Heiskanen

    2012-10-01

    Full Text Available In this research article the sustainability of different practices to collect the metal fraction of household waste in the Helsinki metropolitan area, Finland is examined. The study is carried out by calculating and comparing the greenhouse gas reduction potential of optional practices for collecting the metal fraction of household waste in the Helsinki metropolitan area, Finland. In order to locate the greenhouse gas reduction potential of the separate collection of the metallic fraction of municipal solid waste (MSW collected from residential sources, a comparative carbon footprint analysis using Life Cycle Assessment (LCA on six different waste management scenarios is carried out. The modeled system consisted of a waste collection system, transportation, and different waste management alternatives, including on-site separation, separation at the waste management facility as well as metallurgical recovery of separated scrap. The results show that, in terms of greenhouse gas emissions, separate collection and recycling of the metallic fraction of solid MSW at residential properties is the preferable option compared to a scenario with no source sorting and incineration of everything. According to this research scenario where the metal fraction of solid household waste was not source-separated or collected separately have clearly higher greenhouse gas emissions compared to all the other scenarios with separate collection for metals. In addition, metal recycling by regional collection points has considerably lower greenhouse gas emission potential than metal recycling by collection directly from residential properties.

  16. Adsorption behavior of calcined layered double hydroxides towards removal of iodide contaminants

    International Nuclear Information System (INIS)

    Lu Liang; He Jing; Wei Min; Evans, D.G.; Duan Xue

    2005-01-01

    Layered double hydroxides (LDHs), are a class of synthetic anionic clays whose structure can be described as containing brucite-like layers in which some of the divalent cations have been replaced by trivalent ions giving positively-charged sheets. This charge is balanced by intercalation of anions in the hydrated interlayer regions. The general formula is EM 2+ 1-x M 3+ x (OH) 2 ] x+ (A n- ) x/n · mH 2 O, where M 2+ and M 3+ are metal cations for example Mg 2+ and Al 3+ , that occupy octahedral sites in the hydroxide layers, A n- is an exchangeable anion, and x is the ratio M 3+ /(M 2+ + M 3+ ) and the layer charge will depend on the M 2+ /M 3+ ratio. LDHs act as sorbents of anionic species through two types of reactions, namely, anion exchange and reconstruction, which further adds the possibility of recycling and reuse. The sorption of anions from aqueous solutions by structural reconstruction of a calcined LDH is based on a very interesting property of these materials, the so-called memory effect: Calcination of LDHs produces intermediate non-stoichiometric oxides (CLDH) which undergo rehydration in aqueous medium and give back the hydroxide structure with different anions in the interlayers. Radioactive iodide is widely used in biological experiments, medical treatments and in diagnosis. During fission of uranium several iodine species are produced. All the short lived isotopes of iodine, including 1311 (half life 8.04 days), decay and only 127 I (stable) and 129 I (half life 1.59 x 10 7 years) remain as a problem. 129 I is especially considered as one of the key radionuclides that dominate the long-term radiation in underground radioactive waste stores. Iodine is one of the nuclides causing most concern among radioactive anions. Different adsorbents such as zeolites, silica gel, anion exchange paper membrane, activated carbon and activated carbon fibers, have been investigated as potential materials for elimination of iodide from liquid wastes. In this work

  17. Metal recovery by bioleaching of sulfidic mining wastes — Application to a European case study

    Science.gov (United States)

    Guézennec, A. G.; Jacob, J.; Joulian, C.; Dupraz, S.; Menard, Y.; d'Hugues, P.

    The non-energy extractive industry (NEEI) of the EU-25 generated a direct turnover of about €40 billion, and provided employment to about 250000 people in 16629 companies in 2004. The use of primary raw materials in the production of other branches of EU industry means they have a central role in guaranteeing industrial and economic sustainability. Nevertheless current demand exceeds production, and so the EU is heavily dependent on minerals and metals imports. In this context of securing access to metals, turning mining wastes into new resources of currently unexploited valuable metals is an important challenge. The mining wastes can contain base and precious metals, but also metalloids and rare earth elements that are nowadays considered as highly critical for the industrial development of the European Union. Nevertheless, the development of alternative routes to conventional processing is still required in order to decrease the cost associated to the treatment of these unconventional resources which are more complex in composition and with lower grades.

  18. Variation and distribution of metals and metalloids in soil/ash mixtures from Agbogbloshie e-waste recycling site in Accra, Ghana

    Energy Technology Data Exchange (ETDEWEB)

    Itai, Takaaki, E-mail: itai@sci.ehime-u.ac.jp [Center for Marine Environmental Studies, Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577 (Japan); Otsuka, Masanari [Center for Marine Environmental Studies, Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577 (Japan); Asante, Kwadwo Ansong [Center for Marine Environmental Studies, Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577 (Japan); CSIR Water Research Institute, P. O. Box AH 38, Achimota, Accra (Ghana); Muto, Mamoru [Center for Marine Environmental Studies, Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577 (Japan); Opoku-Ankomah, Yaw; Ansa-Asare, Osmund Duodu [CSIR Water Research Institute, P. O. Box AH 38, Achimota, Accra (Ghana); Tanabe, Shinsuke [Center for Marine Environmental Studies, Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577 (Japan)

    2014-02-01

    Illegal import and improper recycling of electronic waste (e-waste) are an environmental issue in developing countries around the world. African countries are no exception to this problem and the Agbogbloshie market in Accra, Ghana is a well-known e-waste recycling site. We have studied the levels of metal(loid)s in the mixtures of residual ash, formed by the burning of e-waste, and the cover soil, obtained using a portable X-ray fluorescence spectrometer (P-XRF) coupled with determination of the 1 M HCl-extractable fraction by an inductively coupled plasma mass spectrometer. The accuracy and precision of the P-XRF measurements were evaluated by measuring 18 standard reference materials; this indicated the acceptable but limited quality of this method as a screening tool. The HCl-extractable levels of Al, Co, Cu, Zn, Cd, In, Sb, Ba, and Pb in 10 soil/ash mixtures varied by more than one order of magnitude. The levels of these metal(loid)s were found to be correlated with the color (i.e., soil/ash ratio), suggesting that they are being released from disposed e-waste via open burning. The source of rare elements could be constrained using correlation to the predominant metals. Human hazard quotient values based on ingestion of soil/ash mixtures exceeded unity for Pb, As, Sb, and Cu in a high-exposure scenario. This study showed that along with common metals, rare metal(loid)s are also enriched in the e-waste burning site. We suggest that risk assessment considering exposure to multiple metal(loid)s should be addressed in studies of e-waste recycling sites. - Highlights: • Contamination on the largest e-waste recycling site in Africa was investigated. • Portable X-ray Fluorescence analyzer useful for first screening • High levels of Cu, Zn, Pb, and Al in soil/ash mixtures • Hazards for workers are significant.

  19. Variation and distribution of metals and metalloids in soil/ash mixtures from Agbogbloshie e-waste recycling site in Accra, Ghana

    International Nuclear Information System (INIS)

    Itai, Takaaki; Otsuka, Masanari; Asante, Kwadwo Ansong; Muto, Mamoru; Opoku-Ankomah, Yaw; Ansa-Asare, Osmund Duodu; Tanabe, Shinsuke

    2014-01-01

    Illegal import and improper recycling of electronic waste (e-waste) are an environmental issue in developing countries around the world. African countries are no exception to this problem and the Agbogbloshie market in Accra, Ghana is a well-known e-waste recycling site. We have studied the levels of metal(loid)s in the mixtures of residual ash, formed by the burning of e-waste, and the cover soil, obtained using a portable X-ray fluorescence spectrometer (P-XRF) coupled with determination of the 1 M HCl-extractable fraction by an inductively coupled plasma mass spectrometer. The accuracy and precision of the P-XRF measurements were evaluated by measuring 18 standard reference materials; this indicated the acceptable but limited quality of this method as a screening tool. The HCl-extractable levels of Al, Co, Cu, Zn, Cd, In, Sb, Ba, and Pb in 10 soil/ash mixtures varied by more than one order of magnitude. The levels of these metal(loid)s were found to be correlated with the color (i.e., soil/ash ratio), suggesting that they are being released from disposed e-waste via open burning. The source of rare elements could be constrained using correlation to the predominant metals. Human hazard quotient values based on ingestion of soil/ash mixtures exceeded unity for Pb, As, Sb, and Cu in a high-exposure scenario. This study showed that along with common metals, rare metal(loid)s are also enriched in the e-waste burning site. We suggest that risk assessment considering exposure to multiple metal(loid)s should be addressed in studies of e-waste recycling sites. - Highlights: • Contamination on the largest e-waste recycling site in Africa was investigated. • Portable X-ray Fluorescence analyzer useful for first screening • High levels of Cu, Zn, Pb, and Al in soil/ash mixtures • Hazards for workers are significant

  20. Electrochemical probing of high-level radioactive waste tanks containing washed sludge and precipitates

    International Nuclear Information System (INIS)

    Bickford, D.F.; Congdon, J.W.; Oblath, S.B.

    1986-12-01

    At the US Department of Energy's Savannah River Plant, corrosion of carbon steel storage tanks containing alkaline, high-level radioactive waste is controlled by specification of limits on waste composition and temperature. Processes for the preparation of waste for final disposal will result in waste with low corrosion inhibitor concentrations and, in some cases, high aromatic organic concentrations, neither of which are characteristic of previous operations. Laboratory tests, conducted to determine minimum corrosion inhibitor levels indicated pitting of carbon steel near the waterline for proposed storage conditions. In situ electrochemical measurements of full-scale radioactive process demonstrations have been conducted to assess the validity of laboratory tests. Probes included pH, Eh (potential relative to a standard hydrogen electrode), tank potential, and alloy coupons. In situ results are compared to those of the laboratory tests, with particular regard given to simulated solution composition. Transition metal hydroxide sludge contains strong passivating species for carbon steel. Washed precipitate contains organic species that lower solution pH and tend to reduce passivating films, requiring higher inhibitor concentrations than the 0.01 molar nitrite required for reactor fuel reprocessing wastes. Periodic agitation, to keep the organic phase suspended, or cathodic protection are possible alternatives to higher nitrite inhibitor concentrations

  1. 21 CFR 73.1326 - Chromium hydroxide green.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Chromium hydroxide green. 73.1326 Section 73.1326... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1326 Chromium hydroxide green. (a) Identity. (1) The color additive chromium hydroxide green is principally hydrated chromic sesquioxide (Cr2O3·XH2O...

  2. Survey the Effect of Pistachio Waste Composting Process with Different Treatments on Concentration of Heavy Metals

    Directory of Open Access Journals (Sweden)

    M Jalili

    2016-09-01

    Full Text Available Abstract Introduction: Composting is one of the pistachio wastes management methods. In the appropriate compost production nutrients and heavy metals are determinant. The aim of this study is survey the effect of pistachio wastes composting process with different treatments on the concentration of heavy metals. Methods: In this study, during the 60-day pistachio wastes composting process with two treatments of dewatered sewage sludge and cow manure, pH, EC, carbon to nitrogen ratio, Heavy metals and nutrients indicators were studied. The results were compared with WHO and Iranian National standard. Drawing the diagrams by Excel software (Version 2007 and Statistical analysis was performed by Spss Software (version 20 at a significance level of 0.005.  Results: During the 60-day composting pH initially had downward trend and then increased. The Cu, Zn, Fe, Mn and C/N ratio had downward trend and the EC, Na, K had increasing trend. Eventually, Iron, zinc, copper and manganese were less than the standard, Sodium was in Standard range and potassium was more than specified standards in the produced compost from pistachios waste with both treatments.  Conclusion: The results showed that the concentration of heavy metals and nutrients in the produced compost with both treatments were in the acceptable range. Eventually quality of produced compost with cow manure treatment due to better decomposition and greater stability was better than processed compost with dewatered sewage sludge treatment.

  3. Solidification of aqueous radioactive waste using insoluble compounds of magnesium oxide

    International Nuclear Information System (INIS)

    Carlson, J.E.

    1986-01-01

    A process is described for the treatment of radioactive waste which comprises: (a) first adding, under continuous agitation, a sufficient amount of a powdered magnesium oxide or magnesium hydroxide to an aqueous radioactive waste solution containing boric acid, the temperature of the water solution being 55-95 degrees C. to produce a magnesium borate derivative; (b) adding cement, under continuous agitation, to the magnesium borate derivative; and (c) then adding, under continuous agitation, after the cement has been dispersed, a sufficient amount of a compound selected from the group consisting of calcium oxide and calcium hydroxide to (b) to produce a gel matrix structure

  4. Chemical Remediation of Nickel(II) Waste: A Laboratory Experiment for General Chemistry Students

    Science.gov (United States)

    Corcoran, K. Blake; Rood, Brian E.; Trogden, Bridget G.

    2011-01-01

    This project involved developing a method to remediate large quantities of aqueous waste from a general chemistry laboratory experiment. Aqueous Ni(II) waste from a general chemistry laboratory experiment was converted into solid nickel hydroxide hydrate with a substantial decrease in waste volume. The remediation method was developed for a…

  5. Modelling of crevice corrosion induced failure of nuclear waste containers. Abstract 389

    Energy Technology Data Exchange (ETDEWEB)

    Heppner, K.L.; Evitts, R.W.; Postlethwaite, J. [Univ. of Saskatchewan, Dept. of Chemical Engineering, Saskatoon, Saskatchewan (Canada)]. E-mail: klh117@mail.usask.ca; rwe380@engr.usask.ca; jack@dvinci.usask.ca

    2004-07-01

    'Full text:' Alloys which are used for nuclear waste containment applications are selected based upon their mechanical properties and corrosion resistance. However, alloys which are resistant to uniform corrosion, such as titanium alloys, are susceptible to crevice corrosion when exposed to geochemical brines. Passive metals, such as Grade-2 titanium alloy, form a tenacious oxide surface film that protects the metal from corrosion. For a crevice with a very small opening, oxygen reduction inside the crevice may occur faster than oxygen diffusion into the crevice, a condition that leads to crevice solution deoxygenation. Crevice deoxygenation causes oxygen reduction to occur only outside the crevice. Thus, the anode and cathode are physically separated and this causes an acid chloride crevice solution to form by two mechanisms. First, the separated anode and cathode forms an electrical potential gradient. The potential gradient drives the migration of chloride ions into the crevice. Second, metal ions released by dissolution are hydrolyzed to produce metal hydroxides and hydrogen ions. The pH of the crevice solution drops because oxygen reduction, which produces hydroxide ions to neutralize the acidity, no longer occurs inside the crevice. If a solution of sufficiently low pH and sufficiently high chloride ion concentration develops, the protective passive film is dissolved. The time at which this occurs is the incubation period. In this work, a moderately dilute electrolyte mass transport model is coupled with Pitzer's Equations to predict the chemical composition of a Grade-2 titanium alloy crevice solution immersed in a Na-K-Cl brine. The results indicate that the incubation period is highly dependent upon the size of the crevice opening and the temperature of the brine. (author)

  6. Treatment of radioactive waste water by flocculation method, (1)

    International Nuclear Information System (INIS)

    Kimura, Syojiro; Tsutsui, Tenson.

    1976-01-01

    Coagulation property of particle on the treatment of radioactive waste water by floculation method is varied with its electrical potential and mixing condition. The surface state of the particle is influenced by contents of coexistent materials in the waste water and added materials at the treatment process. In the case of using ferric hydroxide as coagulant, assuming the ions which decide the potential of the particle surface are Fe(OH) 2 + and Fe(OH) 4 - , calculated values of the potential agree with zeta-potential of ferric hydroxide particle which is formed from FeCl 4 and NaOH in demineralized water. When Na 2 CO 3 is in the waste water as coexistent materials, anion HCO 3 - adsorbs on the particle surface in connection with pH variation and thus the surface charge is being minus. If Ca 2+ ion is present in the waste water, the surface charge plus. ABS acts as single molecule anion at low concentration, but it forms micell at high concentration and influences zeta-potential of the particle. The potential of the particle is correlated to the coprecipitation rate of 90 Sr in the waste water. (auth.)

  7. Use of scalp hair as indicator of human exposure to heavy metals in an electronic waste recycling area

    International Nuclear Information System (INIS)

    Wang Thanh; Fu Jianjie; Wang Yawei; Liao Chunyang; Tao Yongqing; Jiang Guibin

    2009-01-01

    Scalp hair samples were collected at an electronic waste (e-waste) recycling area and analyzed for trace elements and heavy metals. Elevated levels were found for Cu and Pb with geometric means (GMs) at 39.8 and 49.5 μg/g, and the levels of all elements were found in the rank order Pb > Cu >> Mn > Ba > Cr > Ni > Cd > As > V. Besides Cu and Pb, Cd (GM: 0.518 μg/g) was also found to be significantly higher compared to that in hair samples from control areas. Differences with age, gender, residence status and villages could be distinguished for most of the elements. The high levels of Cd, Cu and Pb were likely found to be originated from e-waste related activities, and specific sources were discussed. This study shows that human scalp hair could be a useful biomarker to assess the extent of heavy metal exposure to workers and residents in areas with intensive e-waste recycling activities. - Human scalp hair samples can be used to indicate environmental and occupational exposure of heavy metals due to intensive electronic waste recycling activities.

  8. Status and progress in sludge washing: A pivotal pretreatment method

    International Nuclear Information System (INIS)

    Barton, W.B.; MacLean, G.T.; Meng, C.D.; Winkler, C.M.

    1995-01-01

    Separation of the bulk soluble chemical salts from the insoluble metal hydroxides and radionuclides is central to the strategy of disposing Hanford tank waste. Sludge washing and caustic leaching have been selected as the primary methods for processing the 230 million L (61,000,000 gal) of Hanford tank waste. These processes are very similar to those selected for processing waste at the West Valley Site in New York and the Savannah River Site in South Carolina. The purpose of sludge washing is to dissolve and remove the soluble salts in the waste. Leaching of the insoluble solids with caustic will be used to dissolve aluminum hydroxide and chromium hydroxide, and convert insoluble bismuth phosphate to soluble phosphate. The waste will be separated into a high-level solids fraction and a liquid fraction that can be disposed of as low-level waste after cesium removal. The washing and leaching operations involve batchwise mixing, settling, and decanting within the existing underground storage tanks

  9. Technology for Treatment of Liquid Radioactive Waste Generated during Uranium and Plutonium Chemical and Metallurgical Manufacturing in FSUE PO Mayak - 13616

    Energy Technology Data Exchange (ETDEWEB)

    Adamovich, D. [SUE MosSIA Radon, 2/14 7th Rostovsky lane, Moscow, 119121 (Russian Federation); Batorshin, G.; Logunov, M.; Musalnikov, A. [FSUE ' PO Mayak' , 31 av. Lenin, Ozyorsk, Chelyabinsk region, 456780 (Russian Federation)

    2013-07-01

    Created technological scheme for treatment of liquid radioactive waste generated while uranium and plutonium chemical and metallurgical manufacturing consists of: - Liquid radioactive waste (LRW) purification from radionuclides and its transfer into category of manufacturing waste; - Concentration of suspensions containing alpha-nuclides and their further conversion to safe dry state (calcinate) and moving to long controlled storage. The following technologies are implemented in LRW treatment complex: - Settling and filtering technology for treatment of liquid intermediate-level waste (ILW) with volume about 1500m{sup 3}/year and alpha-activity from 10{sup 6} to 10{sup 8} Bq/dm{sup 3} - Membrane and sorption technology for processing of low-level waste (LLW) of radioactive drain waters with volume about 150 000 m{sup 3}/year and alpha-activity from 10{sup 3} to 10{sup 4} Bq/dm{sup 3}. Settling and filtering technology includes two stages of ILW immobilization accompanied with primary settling of radionuclides on transition metal hydroxides with the following flushing and drying of the pulp generated; secondary deep after settling of radionuclides on transition metal hydroxides with the following solid phase concentration by the method of tangential flow ultrafiltration. Besides, the installation capacity on permeate is not less than 3 m{sup 3}/h. Concentrates generated are sent to calcination on microwave drying (MW drying) unit. Membrane and sorption technology includes processing of averaged sewage flux by the method of tangential flow ultrafiltration with total capacity of installations on permeate not less than 18 m{sup 3}/h and sorption extraction of uranium from permeate on anionite. According to radionuclide contamination level purified solution refers to general industrial waste. Concentrates generated during suspension filtering are evaporated in rotary film evaporator (RFE) in order to remove excess water, thereafter they are dried on infrared heating

  10. A study of transformation water - soluble forms of hevy metals at waste incenerator for detoxicationof ash.

    Directory of Open Access Journals (Sweden)

    Bilets'ka V. А.

    2011-11-01

    Full Text Available The complex research processes of transformation of soluble forms of heavy metals in sediment interaction with ash. Proved that the adsorption processes of immobilization lead to a significant decrease of soluble forms of heavy metals in the waste.

  11. Immobilization of metal wastes by reaction with H2S in anoxic basins. Concept and Elaboration

    NARCIS (Netherlands)

    Schuiling, R.D.

    2013-01-01

    Metal wastes are produced in large quantities by a number of industries. Their disposal in isolated waste deposits is certain to cause many subsequent problems, because every material will sooner or later return to the geochemical cycle. The sealing of disposal sites usually starts to

  12. Selective extraction and recovery of rare earth metals from phosphor powders in waste fluorescent lamps using an ionic liquid system.

    Science.gov (United States)

    Yang, Fan; Kubota, Fukiko; Baba, Yuzo; Kamiya, Noriho; Goto, Masahiro

    2013-06-15

    The recycling of rare earth metals from phosphor powders in waste fluorescent lamps by solvent extraction using ionic liquids was studied. Acid leaching of rare earth metals from the waste phosphor powder was examined first. Yttrium (Y) and europium (Eu) dissolved readily in the acid solution; however, the leaching of other rare earth metals required substantial energy input. Ionization of target rare earth metals from the waste phosphor powders into the leach solution was critical for their successful recovery. As a high temperature was required for the complete leaching of all rare earth metals, ionic liquids, for which vapor pressure is negligible, were used as an alternative extracting phase to the conventional organic diluent. An extractant, N, N-dioctyldiglycol amic acid (DODGAA), which was recently developed, showed a high affinity for rare earth metal ions in liquid-liquid extraction although a conventional commercial phosphonic extractant did not. An effective recovery of the rare earth metals, Y, Eu, La and Ce, from the metal impurities, Fe, Al and Zn, was achieved from the acidic leach solution of phosphor powders using an ionic liquid containing DODGAA as novel extractant system. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Density-functional tight-binding investigation of the structure, stability and material properties of nickel hydroxide nanotubes

    Science.gov (United States)

    Jahangiri, Soran; Mosey, Nicholas J.

    2018-01-01

    Nickel hydroxide is a material composed of two-dimensional layers that can be rolled up to form cylindrical nanotubes belonging to a class of inorganic metal hydroxide nanotubes that are candidates for applications in catalysis, energy storage, and microelectronics. The stabilities and other properties of this class of inorganic nanotubes have not yet been investigated in detail. The present study uses self-consistent-charge density-functional tight-binding calculations to examine the stabilities, mechanical properties, and electronic properties of nickel hydroxide nanotubes along with the energetics associated with the adsorption of water by these systems. The tight-binding model was parametrized for this system based on the results of first-principles calculations. The stabilities of the nanotubes were examined by calculating strain energies and performing molecular dynamics simulations. The results indicate that single-walled nickel hydroxide nanotubes are stable at room temperature, which is consistent with experimental investigations. The nanotubes possess size-dependent mechanical properties that are similar in magnitude to those of other inorganic nanotubes. The electronic properties of the nanotubes were also found to be size-dependent and small nickel oxyhydroxide nanotubes are predicted to be semiconductors. Despite this size-dependence, both the mechanical and electronic properties were found to be almost independent of the helical structure of the nanotubes. The calculations also show that water molecules have higher adsorption energies when binding to the interior of the nickel hydroxide nanotubes when compared to adsorption in nanotubes formed from other two-dimensional materials such as graphene. The increased adsorption energy is due to the hydrophilic nature of nickel hydroxide. Due to the broad applications of nickel hydroxide, the nanotubes investigated here are also expected to be used in catalysis, electronics, and clean energy production.

  14. Capture of organic iodides from nuclear waste by metal-organic framework-based molecular traps.

    Science.gov (United States)

    Li, Baiyan; Dong, Xinglong; Wang, Hao; Ma, Dingxuan; Tan, Kui; Jensen, Stephanie; Deibert, Benjamin J; Butler, Joseph; Cure, Jeremy; Shi, Zhan; Thonhauser, Timo; Chabal, Yves J; Han, Yu; Li, Jing

    2017-09-07

    Effective capture of radioactive organic iodides from nuclear waste remains a significant challenge due to the drawbacks of current adsorbents such as low uptake capacity, high cost, and non-recyclability. We report here a general approach to overcome this challenge by creating radioactive organic iodide molecular traps through functionalization of metal-organic framework materials with tertiary amine-binding sites. The molecular trap exhibits a high CH 3 I saturation uptake capacity of 71 wt% at 150 °C, which is more than 340% higher than the industrial adsorbent Ag 0 @MOR under identical conditions. These functionalized metal-organic frameworks also serve as good adsorbents at low temperatures. Furthermore, the resulting adsorbent can be recycled multiple times without loss of capacity, making recyclability a reality. In combination with its chemical and thermal stability, high capture efficiency and low cost, the adsorbent demonstrates promise for industrial radioactive organic iodides capture from nuclear waste. The capture mechanism was investigated by experimental and theoretical methods.Capturing radioactive organic iodides from nuclear waste is important for safe nuclear energy usage, but remains a significant challenge. Here, Li and co-workers fabricate a stable metal-organic framework functionalized with tertiary amine groups that exhibits high capacities for radioactive organic iodides uptake.

  15. Capture of organic iodides from nuclear waste by metal-organic framework-based molecular traps

    KAUST Repository

    Li, Baiyan

    2017-09-01

    Effective capture of radioactive organic iodides from nuclear waste remains a significant challenge due to the drawbacks of current adsorbents such as low uptake capacity, high cost, and non-recyclability. We report here a general approach to overcome this challenge by creating radioactive organic iodide molecular traps through functionalization of metal-organic framework materials with tertiary amine-binding sites. The molecular trap exhibits a high CH3I saturation uptake capacity of 71 wt% at 150 °C, which is more than 340% higher than the industrial adsorbent Ag0@MOR under identical conditions. These functionalized metal-organic frameworks also serve as good adsorbents at low temperatures. Furthermore, the resulting adsorbent can be recycled multiple times without loss of capacity, making recyclability a reality. In combination with its chemical and thermal stability, high capture efficiency and low cost, the adsorbent demonstrates promise for industrial radioactive organic iodides capture from nuclear waste. The capture mechanism was investigated by experimental and theoretical methods.Capturing radioactive organic iodides from nuclear waste is important for safe nuclear energy usage, but remains a significant challenge. Here, Li and co-workers fabricate a stable metal-organic framework functionalized with tertiary amine groups that exhibits high capacities for radioactive organic iodides uptake.

  16. Synthesis of Platinum-Nickel Hydroxide Nanocomposites for Electrocatalytic Reduction of Water

    KAUST Repository

    Wang, Lei

    2016-11-25

    Water electrolysis represents a promising solution for storage of renewable but intermittent electrical energy in hydrogen molecules. This technology is however challenged by the lack of efficient electrocatalysts for the hydrogen and oxygen evolution reactions. Here we report on the synthesis of platinum-nickel hydroxide nanocomposites and their electrocatalytic applications for water reduction. An in situ reduction strategy taking advantage of the Ni(II)/Ni(III) redox has been developed to enable and regulate the epitaxial growth of Pt nanocrystals on single-layer Ni(OH)2 nanosheets. The obtained nanocomposites (denoted as Pt@2D-Ni(OH)2) exhibit an improvement factor of 5 in catalytic activity and a reduction of up to 130 mV in overpotential compared to Pt for the hydrogen evolution reaction (HER). A combination of electron microscopy/spectroscopy characterization, electrochemical studies and density functional calculations was employed to uncover the structures of the metal-hydroxide interface and understand the mechanisms of catalytic enhancement.

  17. Synthesis of Platinum-Nickel Hydroxide Nanocomposites for Electrocatalytic Reduction of Water

    KAUST Repository

    Wang, Lei; Zhu, Yihan; Zeng, Zhenhua; Lin, Chong; Giroux, Michael; Jiang, Lin; Han, Yu; Greeley, Jeffrey; Wang, Chao; Jin, Jian

    2016-01-01

    Water electrolysis represents a promising solution for storage of renewable but intermittent electrical energy in hydrogen molecules. This technology is however challenged by the lack of efficient electrocatalysts for the hydrogen and oxygen evolution reactions. Here we report on the synthesis of platinum-nickel hydroxide nanocomposites and their electrocatalytic applications for water reduction. An in situ reduction strategy taking advantage of the Ni(II)/Ni(III) redox has been developed to enable and regulate the epitaxial growth of Pt nanocrystals on single-layer Ni(OH)2 nanosheets. The obtained nanocomposites (denoted as Pt@2D-Ni(OH)2) exhibit an improvement factor of 5 in catalytic activity and a reduction of up to 130 mV in overpotential compared to Pt for the hydrogen evolution reaction (HER). A combination of electron microscopy/spectroscopy characterization, electrochemical studies and density functional calculations was employed to uncover the structures of the metal-hydroxide interface and understand the mechanisms of catalytic enhancement.

  18. 40 CFR 62.14103 - Emission limits for municipal waste combustor metals, acid gases, organics, and nitrogen oxides.

    Science.gov (United States)

    2010-07-01

    ... combustor metals, acid gases, organics, and nitrogen oxides. 62.14103 Section 62.14103 Protection of... combustor metals, acid gases, organics, and nitrogen oxides. (a) The emission limits for municipal waste combustor metals are specified in paragraphs (a)(1) through (a)(3) of this section. (1) The owner or...

  19. Effect of ammonium hydroxide on preparation process of YBa2Cu3O7-x superconductor by sol gel method

    Directory of Open Access Journals (Sweden)

    H Arabi

    2006-09-01

    Full Text Available  In this paper the effect of ammonium hydroxide addition to the solution of metallic oxide on sol gel preparation process of YBCO is studied with differential thermal analysis, thermal graviometry and X-ray diffraction. Two samples with and without ammonium hydroxide. Ammonium hydroxide prevents both barium nitrate precipitate during the gel preparation and also unwanted reaction as well as increasing homogeneous product. After drying the gel, the samples heated up to 1050°C in DTA apparatus in order to find more accurate the type and the temperature of reaction during the preparation process. After the initial reactions in the samples, Y2Cu2O5 and 123 phases are created in the range of 780-840°C and then the 123 phase is strengthened at 900-950°C. As shown in X-ray data, 123 was the only phase after this range. In addition ammonium hydroxide support and increase the creation of 123 phase at lower temperature.

  20. Sources of acid and metals from the weathering of the Dinero waste pile, Lake Fork watershed, Leadville, Colorado

    Science.gov (United States)

    Diehl, S.F.; Hageman, Phil L.; Smith, Kathleen S.; Herron, J.T.; Desborough, G.A.

    2005-01-01

    Two trenches were dug into the south Dinero mine-waste pile near Leadville, Colorado, to study the weathering of rock fragments and the mineralogic sources of metal contaminants in the surrounding wetland and Lake Fork Watershed. Water seeping from the base of the south Dinero waste-rock pile was pH 2.9, whereas leachate from a composite sample of the rock waste was pH 3.3. The waste pile was mostly devoid of vegetation, open to infiltration of precipitation, and saturated at the base because of placement in the wetland. The south mine-waste pile is composed of poorly sorted material, ranging from boulder-size to fine-grained rock fragments. The trenches showed both matrix-supported and clast-supported zones, with faint horizontal color banding, suggesting zonation of Fe oxides. Secondary minerals such as jarosite and gypsum occurred throughout the depth of the trenches. Infiltration of water and transport of dissolved material through the pile is evidenced by optically continuous secondary mineral deposits that fill or line voids. Iron-sulfate material exhibits microlaminations with shrinkage cracking and preferential dissolution of microlayers that evidence drying and wetting events. In addition to fluids, submicron-sized to very fine-grained particles such as jarosite are transported through channel ways in the pile. Rock fragments are coated with a mixture of clay, jarosite, and manganese oxides. Dissolution of minerals is a primary source of metals. Skeletal remnants of grains, outlined by Fe-oxide minerals, are common. Potassium jarosite is the most abundant jarosite phase, but Pb-and Ag-bearing jarosite are common. Grain-sized clusters of jarosite suggest that entire sulfide grains were replaced by very fine-grained jarosite crystals. The waste piles were removed from the wetland and reclaimed upslope in 2003. This was an opportunity to test methods to identify sources of acid and metals and metal transport processes within a waste pile. A series of

  1. Arsenic mineralogy and mobility in the arsenic-rich historical mine waste dump

    International Nuclear Information System (INIS)

    Filippi, Michal; Drahota, Petr; Machovič, Vladimír; Böhmová, Vlasta; Mihaljevič, Martin

    2015-01-01

    A more than 250 year-old mine dump was studied to document the products of long-term arsenopyrite oxidation under natural conditions in a coarse-grained mine waste dump and to evaluate the environmental hazards associated with this material. Using complementary mineralogical and chemical approaches (SEM/EDS/WDS, XRD, micro-Raman spectroscopy, pore water analysis, chemical extraction techniques and thermodynamic PHREEQC-2 modeling), we documented the mineralogical/geochemical characteristics of the dumped arsenopyrite-rich material and environmental stability of the newly formed secondary minerals. A distinct mineralogical zonation was found (listed based on the distance from the decomposed arsenopyrite): scorodite (locally associated with native sulfur pseudomorphs) plus amorphous ferric arsenate (AFA/pitticite), kaňkite, As-bearing ferric (hydr)oxides and jarosite. Ferric arsenates and ferric (hydr)oxides were found to dissolve and again precipitate from downward migrating As-rich solutions cementing rock fragments. Acidic pore water (pH 3.8) has elevated concentrations of As with an average value of about 2.9 mg L −1 . Aqueous As is highly correlated with pH (R 2 = 0.97, p < 0.001) indicating that incongruent dissolution of ferric arsenates controls dissolved As well as the pH of the percolating waste solution. Arsenic released from the dissolution of ferric arsenates into the pore water is, however, trapped by latter and lower-down precipitating jarosite and especially ferric (hydr)oxides. The efficiency of As sequestration by ferric (hydr)oxides in the waste dump and underlying soil has been found to be very effective, suggesting limited environmental impact of the mine waste dump on the surrounding soil ecosystems. - Highlights: • More than 250 year-old arsenopyrite-rich mine waste dump was studied. • Mineral transformation and the environmental stability of different secondary arsenic mineral phases were assessed. • High efficiency of As

  2. Valorization of titanium metal wastes as tanning agent used in leather industry.

    Science.gov (United States)

    Crudu, Marian; Deselnicu, Viorica; Deselnicu, Dana Corina; Albu, Luminita

    2014-10-01

    The development of new tanning agents and new technologies in the leather sector is required to cope with the increasingly higher environmental pressure on the current tanning materials and processes such as tanning with chromium salts. In this paper, the use of titanium wastes (cuttings) resulting from the process of obtaining highly pure titanium (ingots), for the synthesis of new tanning agent and tanning bovine hides with new tanning agent, as alternative to tanning with chromium salts are investigated. For this purpose, Ti waste and Ti-based tanning agent were characterized for metal content by inductively coupled plasma mass spectrometry (ICP-MS) and chemical analysis; the tanned leather (wet white leather) was characterized by Scanning Electron Microscope/Energy Dispersive Using X-ray (Analysis). SEM/EDX analysis for metal content; Differential scanning calorimetric (DSC), Micro-Hot-Table and standard shrinkage temperature showing a hydrothermal stability (ranged from 75.3 to 77°C) and chemical analysis showing the leather is tanned and can be processed through the subsequent mechanical operations (splitting, shaving). On the other hand, an analysis of major minor trace substances from Ti-end waste (especially vanadium content) in new tanning agent and wet white leather (not detected) and residue stream was performed and showed that leachability of vanadium is acceptable. The results obtained show that new tanning agent obtained from Ti end waste can be used for tanning bovine hides, as eco-friendly alternative for chrome tanning. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. A U-bearing composite waste form for electrochemical processing wastes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, X.; Ebert, W. L.; Indacochea, J. E.

    2018-04-01

    Metallic/ceramic composite waste forms are being developed to immobilize combined metallic and oxide waste streams generated during electrochemical recycling of used nuclear fuel. Composites were made for corrosion testing by reacting HT9 steel to represent fuel cladding, Zr and Mo to simulate metallic fuel waste, and a mixture of ZrO2, Nd2O3, and UO2 to represent oxide wastes. More than half of the added UO2 was reduced to metal and formed Fe-Zr-U intermetallics and most of the remaining UO2 and all of the Nd2O3 reacted to form zirconates. Fe-Cr-Mo intermetallics were also formed. Microstructure characterization of the intermetallic and ceramic phases that were generated and tests conducted to evaluate their corrosion behaviors indicate composite waste forms can accommodate both metallic and oxidized waste streams in durable host phases. (c) 2018 Elsevier B.V. All rights reserved.

  4. Sorption Potentials of Waste Tyre for Some Heavy Metals (Pb Cd in Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Austin Kanayo ASIAGWU

    2009-07-01

    Full Text Available An investigation into the adsorption potential of activated and inactivated waste tyre powders for some heavy metals (Pb2+ and Cd2+ in their aqueous solution has been studied. The result indicated that inactivated waste tyre is a good non-conventional adsorbent for the removal of Cd from aqueous solution. A total of 93.3% of Cadmium contents was removed. The inactivated waste type proved a good adsorbent for the removal of Pb2+ 5g of 500mm activated tyre removed over 86.66% of Pb2+ from solution.

  5. Iron and aluminium oxides containing industrial wastes as adsorbents of heavy metals: Application possibilities and limitations.

    Science.gov (United States)

    Jacukowicz-Sobala, Irena; Ociński, Daniel; Kociołek-Balawejder, Elżbieta

    2015-07-01

    Industrial wastes with a high iron or aluminium oxide content are produced in huge quantities as by-products of water treatment (water treatment residuals), bauxite processing (red mud) and hard and brown coal burning in power plants (fly ash). Although they vary in their composition, the wastes have one thing in common--a high content of amorphous iron and/or aluminium oxides with a large specific surface area, whereby this group of wastes shows very good adsorbability towards heavy metals, arsenates, selenates, etc. But their physical form makes their utilisation quite difficult, since it is not easy to separate the spent sorbent from the solution and high bed hydraulic resistances occur in dynamic regime processes. Nevertheless, because of the potential benefits of utilising the wastes in industrial effluent treatment, this issue attracts much attention today. This study describes in detail the waste generation processes, the chemical structure of the wastes, their physicochemical properties, and the mechanisms of fixing heavy metals and semimetals on the surface of iron and aluminium oxides. Typical compositions of wastes generated in selected industrial plants are given. A detailed survey of the literature on the adsorption applications of the wastes, including methods of their thermal and chemical activation, as well as regeneration of the spent sorbents, is presented. The existing and potential ways of modifying the physical form of the discussed group of wastes, making it possible to overcome the basic limitation on their practical use, are discussed. © The Author(s) 2015.

  6. Analysis of barium hydroxide and calcium hydroxide slurry carbonation reactors

    International Nuclear Information System (INIS)

    Patch, K.D.; Hart, R.P.; Schumacher, W.A.

    1980-05-01

    The removal of CO 2 from air was investigated by using a continuous-agitated-slurry carbonation reactor containing either barium hydroxide [Ba(OH) 2 ] or calcium hydroxide [Ca(OH) 2 ]. Such a process would be applied to scrub 14 CO 2 from stack gases at nuclear-fuel reprocessing plants. Decontamination factors were characterized for reactor conditions which could alter hydrodynamic behavior. An attempt was made to characterize reactor performance with models assuming both plug flow and various degrees of backmixing in the gas phase. The Ba(OH) 2 slurry enabled increased conversion, but apparently the process was controlled under some conditions by phenomena differing from those observed for carbonation by Ca(OH) 2 . Overall reaction mechanisms are postulated

  7. Heavy metal removal and recovery using microorganisms. Volume 1, State-of-the-art and potential applications at the SRS

    Energy Technology Data Exchange (ETDEWEB)

    Wilde, E.W. [Westinghouse Savannah River Co., Aiken, SC (United States); Benemann, J.R. [Benemann (J.R.), Pinole, CA (United States)

    1991-02-01

    Microorganisms -- bacteria, fungi, and microalgae -- can accumulate relatively large amounts of toxic heavy metals and radionuclides from the environment. These organisms often exhibit specificity for particular metals. The metal content of microbial biomass can be a substantial fraction of total dry weight with concentration factors (metal in dry biomass to metal in solution) exceeding one million in some cases. Both living and inert (dead) microbial biomass can be used to reduce heavy metal concentrations in contaminated waters to very low levels -- parts per billion and even lower. In many respects (e.g. specificity, residual metal concentrations, accumulation factors, and economics) microbial bioremoval processes can be superior to conventional processes, such as ion exchange and caustic (lime or hydroxide) precipitation for heavy metals removal from waste and contaminated waters. Thus, bioremoval could be developed to contribute to the clean-up of wastes at the Savannah River Site (SRS) and other DOE facilities. However, the potential advantages of bioremoval processes must still be developed into practical operating systems. A detailed review of the literature suggests that appropriate bioremoval processes could be developed for the SRS. There is great variability from one biomass source to another in bioremoval capabilities. Bioremoval is affected by pH, other ions, temperature, and many other factors. The biological (living vs. dead) and physical (immobilized vs. dispersed) characteristics of the biomass also greatly affect metal binding. Even subtle differences in the microbial biomass, such as the conditions under which it was cultivated, can have major effects on heavy metal binding.

  8. Preparation of value-added metal-organic frameworks (MOFs) using waste PET bottles as source of acid linker

    CSIR Research Space (South Africa)

    Dyosiba, Xoliswa

    2016-12-01

    Full Text Available of Value-added Metal-organic Frameworks (MOFs) Using Waste PET Bottles as Source of Acid Linker Xoliswa Dyosiba, Jianwei Ren, Nicholas M. Musyoka, Henrietta W. Langmi, Mkhulu Mathe, Maurice S. Onyango PII: S2214-9937(16)30053-7 DOI: doi:10.1016/j..., Hen- rietta W. Langmi, Mkhulu Mathe, Maurice S. Onyango, Preparation of Value-added Metal-organic Frameworks (MOFs) Using Waste PET Bottles as Source of Acid Linker, Sustainable Materials and Technologies (2016), doi:10.1016/j.susmat.2016...

  9. Recycling of non-metallic fractions from waste printed circuit boards: A review

    International Nuclear Information System (INIS)

    Guo Jiuyong; Guo Jie; Xu Zhenming

    2009-01-01

    The major economic driving force for recycling of waste printed circuit boards (PCBs) is the value of the metallic fractions (MFs) of PCBs. The non-metallic fractions (NMFs), which take up almost 70 wt% of waste PCBs, were treated by combustion or land filling in the past. However, combustion of the NMFs will cause the formation of highly toxic polybrominated dibenzodioxins and dibenzofurans (PBDD/Fs) while land filling of the NMFs will lead to secondary pollution caused by heavy metals and brominated flame retardants (BFRs) leaching to the groundwater. Therefore, recycling of the NMFs from waste PCBs is drawing more and more attention from the public and the governments. Currently, how to recycle the NMFs environmental soundly has become a significant topic in recycling of waste PCBs. In order to fulfill the better resource utilization of the NMFs, the compositions and characteristics of the NMFs, methods and outcomes of recycling the NMFs from waste PCBs and analysis and treatment for the hazardous substances contained in the NMFs were reviewed in this paper. Thermosetting resin matrix composites, thermoplastic matrix composites, concrete and viscoelastic materials are main applications for physical recycling of the NMFs. Chemical recycling methods consisting of pyrolysis, gasification, supercritical fluids depolymerization and hydrogenolytic degradation can be used to convert the NMFs to chemical feedstocks and fuels. The toxicity characteristic leaching procedure (TCLP) and synthetic precipitation leaching procedure (SPLP) can be used to determine the toxicity characteristic (TC) of the NMFs and to evaluate the environmental safety of products made from the recycled NMFs. It is believed that physical recycling of the NMFs has been a promising recycling method. Much more work should be done to develop comprehensive and industrialized usage of the NMFs recycled by physical methods. Chemical recycling methods have the advantages in eliminating hazardous substances

  10. Recycling of non-metallic fractions from waste printed circuit boards: A review

    Energy Technology Data Exchange (ETDEWEB)

    Guo Jiuyong; Guo Jie [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Xu Zhenming, E-mail: zmxu@sjtu.edu.cn [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)

    2009-09-15

    The major economic driving force for recycling of waste printed circuit boards (PCBs) is the value of the metallic fractions (MFs) of PCBs. The non-metallic fractions (NMFs), which take up almost 70 wt% of waste PCBs, were treated by combustion or land filling in the past. However, combustion of the NMFs will cause the formation of highly toxic polybrominated dibenzodioxins and dibenzofurans (PBDD/Fs) while land filling of the NMFs will lead to secondary pollution caused by heavy metals and brominated flame retardants (BFRs) leaching to the groundwater. Therefore, recycling of the NMFs from waste PCBs is drawing more and more attention from the public and the governments. Currently, how to recycle the NMFs environmental soundly has become a significant topic in recycling of waste PCBs. In order to fulfill the better resource utilization of the NMFs, the compositions and characteristics of the NMFs, methods and outcomes of recycling the NMFs from waste PCBs and analysis and treatment for the hazardous substances contained in the NMFs were reviewed in this paper. Thermosetting resin matrix composites, thermoplastic matrix composites, concrete and viscoelastic materials are main applications for physical recycling of the NMFs. Chemical recycling methods consisting of pyrolysis, gasification, supercritical fluids depolymerization and hydrogenolytic degradation can be used to convert the NMFs to chemical feedstocks and fuels. The toxicity characteristic leaching procedure (TCLP) and synthetic precipitation leaching procedure (SPLP) can be used to determine the toxicity characteristic (TC) of the NMFs and to evaluate the environmental safety of products made from the recycled NMFs. It is believed that physical recycling of the NMFs has been a promising recycling method. Much more work should be done to develop comprehensive and industrialized usage of the NMFs recycled by physical methods. Chemical recycling methods have the advantages in eliminating hazardous substances

  11. Generation of Hydrogen, Lignin and Sodium Hydroxide from Pulping Black Liquor by Electrolysis

    Directory of Open Access Journals (Sweden)

    Guangzai Nong

    2015-12-01

    Full Text Available Black liquor is generated in Kraft pulping of wood or non-wood raw material in pulp mills, and regarded as a renewable resource. The objective of this paper was to develop an effective means to remove the water pollutants by recovery of both lignin and sodium hydroxide from black liquor, based on electrolysis. The treatment of a 1000 mL of black liquor (122 g/L solid contents consumed 345.6 kJ of electric energy, and led to the generation of 30.7 g of sodium hydroxide, 0.82 g of hydrogen gas and 52.1 g of biomass solids. Therefore, the recovery ratios of elemental sodium and biomass solids are 80.4% and 76%, respectively. Treating black liquor by electrolysis is an environmentally friendly technology that can, in particular, be an alternative process in addressing the environmental issues of pulping waste liquor to the small-scale mills without black liquor recovery.

  12. STABILITY OF DOW CORNING Q2-3183A ANTIFOAM IN IRRADIATED HYDROXIDE SOLUTION

    International Nuclear Information System (INIS)

    White, T.; Crawford, C.; Burket, P.; Calloway, B.

    2009-01-01

    Researchers at the Savannah River National Laboratory (SRNL) examined the stability of Dow Corning Q2-3183A antifoam to radiation and aqueous hydroxide solutions. Initial foam control studies with Hanford tank waste showed the antifoam reduced foaming. The antifoam was further tested using simulated Hanford tank waste spiked with antifoam that was heated and irradiated (2.1 x 10 4 rad/h) at conditions (90 C, 3 M NaOH, 8 h) expected in the processing of radioactive waste through the Waste Treatment and Immobilization Plant (WTP) at Hanford. After irradiation, the concentration of the major polymer components polydimethylsiloxane (PDMS) and polypropylene glycol (PPG) in the antifoam was determined by gel permeation chromatography (GPC). No loss of the major polymer components was observed after 24 h and only 15 wt% loss of PDMS was reported after 48 h. The presence of degradation products were not observed by gas chromatography (GC), gas chromatography mass spectrometry (GCMS) or high performance liquid chromatography mass spectrometry (HPLC-MS). G values were calculated from the GPC analysis and tabulated. The findings indicate the antifoam is stable for 24 h after exposure to gamma radiation, heat, and alkaline simulated waste

  13. Interaction of radium with fresh water sediments and their mineral components Pt. 1. Ferris hydroxide and quartz

    Energy Technology Data Exchange (ETDEWEB)

    Benes, P; Strejc, P; Lukavec, Z [Ceske Vysoke Uceni Technicke, Prague (Czechoslovakia). Katedra Jaderne Chemie

    1984-05-01

    The radiotracer method has been used for investigation of the adsorption and desorption of radium traces on ferric hydroxide and quartz under conditions similar to those prevailing in waste and surface waters. The effects of pH, liquid to solid ratio, ionic strength and presence of Ca/sup 2 +/ or SO/sub 4//sup 2 -/ ions have been studied. It is concluded that at pH less than 7 and at concentration of suspended sediments of common composition less than 100 mg.1/sup -1/, ferric hydroxide and quartz have negligible effect on the state and migration of radium in surface waters. Radium adsorbed on quartz can be easily desorbed with dilute solutions of hydrochloric acid or sodium chloride. 14 refs.

  14. Yucca Mountain project canister material corrosion studies as applied to the electrometallurgical treatment metallic waste form

    International Nuclear Information System (INIS)

    Keiser, D.D.

    1996-11-01

    Yucca Mountain, Nevada is currently being evaluated as a potential site for a geologic repository. As part of the repository assessment activities, candidate materials are being tested for possible use as construction materials for waste package containers. A large portion of this testing effort is focused on determining the long range corrosion properties, in a Yucca Mountain environment, for those materials being considered. Along similar lines, Argonne National Laboratory is testing a metallic alloy waste form that also is scheduled for disposal in a geologic repository, like Yucca Mountain. Due to the fact that Argonne's waste form will require performance testing for an environment similar to what Yucca Mountain canister materials will require, this report was constructed to focus on the types of tests that have been conducted on candidate Yucca Mountain canister materials along with some of the results from these tests. Additionally, this report will discuss testing of Argonne's metal waste form in light of the Yucca Mountain activities

  15. Formation and filtration characteristics of solids generated in a high level liquid waste treatment process. Solids formation behavior from simulated high level liquid waste

    International Nuclear Information System (INIS)

    Kondo, Y.; Kubota, M.

    1997-01-01

    The solids formation behavior in a simulated high level liquid waste (HLLW) was experimentally examined, when the simulated HLLW was treated in the ordinary way of actual HLLW treatment process. Solids formation conditions and mechanism were closely discussed. The solids formation during a concentration step can be explained by considering the formation of zirconium phosphate, phosphomolybdic acid and precipitation of strontium and barium nitrates and their solubilities. For the solids formation during the denitration step, at least four courses were observed; formation of an undissolved material by a chemical reaction with each other of solute elements (zirconium, molybdenum, tellurium) precipitation by reduction (platinum group metals) formation of hydroxide or carbonate compounds (chromium, neodymium, iron, nickel, strontium, barium) and a physical adsorption to stable solid such as zirconium molybdate (nickel, strontium, barium). (author)

  16. Seiler Pollution Control Systems vitrification process for the treatment of hazardous waste streams

    International Nuclear Information System (INIS)

    Nuesch, P.C.; Sarko, A.B.

    1995-01-01

    Seiler Pollution Control Systems, Inc. (Seiler) applies an economical, transportable, compact high temperature vitrification process to recycle and/or stabilize mixed organic/inorganic waste streams. Organic components are gasified by the system and are used as an auxiliary energy source. The inorganic components are melted and bound up molecularly in a glass/ceramic matrix. These glass/ceramics are extremely stable and durable and will pass typical regulatory leachate tests. Waste types that can be processed through the Seiler vitrification system include incinerator flyash, paint sludges, plating wastes, metal hydroxide sludges, low level and mixed radioactive wastes, contaminated soils and sludges, asbestos, and various mixed organic/inorganic residues. For nonradioactive waste streams, a variety of commercially saleable glass/ceramic products can be produced. These materials are marketed either as architectural materials, abrasives, or insulating refractories. The glass/ceramics generated from radioactive waste streams can be formed in a shape that is easily handled, stored, and retrieved. The system, itself is modular and can either be used as a stand alone system or hooked-up in line to existing manufacturing and production facilities. It consists of four sections: feed preparation; preheater; vitrifier/converter, and air pollution control. The vitrification system can use oxygen enriched natural gas or fuel oil for both cost efficiency and to reduce air pollution emissions

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

    Science.gov (United States)

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

    2014-01-01

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

  18. Mineralogic sources of metals in leachates from the weathering of sedex, massive sulfide, and vein deposit mining wastes

    Science.gov (United States)

    Diehl, S.F.; Hageman, P.L.; Seal, R.R.; Piatak, N.M.; Lowers, H.

    2011-01-01

    Weathered mine waste consists of oxidized primary minerals and chemically unstable secondary phases that can be sources of readily soluble metals and acid rock drainage. Elevated concentrations of metals such as Cd, Cu, Fe, Mn, Ni, Pb, and Zn are observed in deionized water-based leachate solutions derived from complex sedex and Cu-Pb-Zn mine wastes. Leachate (USGS FLT) from the Elizabeth mine, a massive sulfide deposit, has a pH of 3.4 and high concentrations of Al (16700 ug/L), Cu (440 ug/L), and Zn (8620 ug/L). Leachate from the sedex Faro mine has a pH of 3.5 and high concentrations of Al (2040 ug/L), Cu (1930 ug/L), Pb (2080 ug/L), and Zn (52900 ug/L). In contrast, higher-pH leachates produced from tailings of polymetallic vein deposits have order of magnitude lower metal concentrations. These data indicate that highly soluble secondary mineral phases exist at the surface of waste material where the samples were collected. Sulfide minerals from all sites exhibit differential degrees of weathering, from dissolution etched grain rims, to rinds of secondary minerals, to skeletal remnants. These microscale mineral-dissolution textures enhance weathering and metal teachability of waste material. Besides the formation of secondary minerals, sulfide grains from dried tailings samples may be coated by amorphous Fe-Al-Si minerals that also adsorb metals such as Cu, Ni, and Zn.

  19. Thermal Analysis and Flame-Retarded Mechanism of Composites Composed of Ethylene Vinyl Acetate and Layered Double Hydroxides Containing Transition Metals (Mn, Co, Cu, Zn

    Directory of Open Access Journals (Sweden)

    Lili Wang

    2016-05-01

    Full Text Available The effects of transition metals on the hydrophobicity of nano–structured layered double hydroxides (LDHs and the compatibility of LDHs/ethylene vinyl acetate (EVA composites have seldom been reported. NiMgAl–LDHs slightly surface–modified with stearate and doped with transition metal cations (Mn2+, Co2+, Cu2+, Zn2+ are investigated. Compared to the pure EVA, not only were the maximal degradation–rate temperatures (Tmax of the ethylene–based chains enhanced, but also the smoke production rate (SPR and the production rate of CO (COP were sharply decreased for all the composites. Most importantly, a new flame retardant mechanism was found, namely the peak heat release rate (pk-HRR time, which directly depends on the peak production rate of CO2 (pk-CO2 time for EVA and all composites by cone calorimeter test. Moreover, the Mn–doped LDH S–NiMgAl–Mn shows more uniform dispersion and better interfacial compatibility in the EVA matrix. The cone calorimetric residue of S–NiMgAl–Mn/EVA has the intumescent char layer and the compact metal oxide layer. Therefore, S–NiMgAl–Mn/EVA shows the lowest pk-HRR and the longest pk-HRR time among all the composites.

  20. Development of a method employing chitosan to remove metallic ions from wastewater

    International Nuclear Information System (INIS)

    Janegitz, Bruno Campos; Lourencao, Bruna Claudia; Lupetti, Karina Omuro; Fatibello-Filho, Orlando

    2007-01-01

    In this work a method was developed for removing metallic ions from wastewaters by co-precipitation of Cu 2+ , Pb 2+ , Cd 2+ , Cr 3+ and Hg 2+ with chitosan and sodium hydroxide solution. Solutions of these metallic ions in the range from 0.55 to 2160 mg L -1 were added to chitosan dissolved in 0.05 mol L -1 HCl. For the co-precipitation of metal-chitosan-hydroxide a 0.17 mol L -1 NaOH solution was added until pH 8.5-9.5. A parallel study was carried out applying a 0.17 mol L -1 NaOH solution to precipitate those metallic ions. Also, a chitosan solid phase column was used for removing those metallic ions from wastewaters. (author)