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Sample records for metal removal final

  1. Enhanced NO{sub x} removal in wet scrubbers using metal chelates. Final report, Volume 1

    SciTech Connect

    Smith, K.; Lani, B.; Berisko, D.; Schultz, C.; Carlson, W.; Benson, L.B.

    1992-12-01

    Successful pilot plant tests of simultaneous removal of S0{sub 2} and NO{sub x} in a wet lime flue gas desulfurization system were concluded in December. The tests, at up to 1.5 MW(e) capacity, were conducted by the Cincinnati Gas and Electric Company and Dravo Lime Company for the US Department of Energy at a pilot facility at the Miami Fort station of CG&E near Cincinnati, Ohio. The pilot plant scrubbed a slipstream of flue gas from Unit 7, a 530 MW coal-fired electric generating unit. Tests were conducted in three phases between April and December. The technology tested was wet scrubbing with Thiosorbic{reg_sign} magnesium-enhanced lime for S0{sub 2} removal and simultaneous NO scrubbing with ferrous EDTA, a metal chelate. Magnesium-enhanced lime-based wet scrubbing is used at 20 full-scale high-sulfur coal-fired electric generating units with a combined capacity of 8500 NW. Ferrous EDTA reacts with nitric oxide, NO, which comprises about 95% of NO{sub x} from coal-fired boilers. In this report, although not precise, NO and NO{sub x} are used interchangably. A major objective of the tests was to combine NO{sub x} removal using ferrous EDTA, a developing technology, with SO{sub 2} removal using wet lime FGD, already in wide commercial use. If successful, this could allow wide application of this NO{sub x} removal technology.

  2. Enhanced NO{sub x} removal in wet scrubbers using metal chelates. Final report, Volume 2

    SciTech Connect

    1992-12-01

    Successful pilot plant tests of simultaneous removal of SO{sub 2} and NO{sub x} in a wet lime flue gas desulfurization system were concluded in December. The test, at up to 1.5 MW(e) capacity, were conducted by the Cincinnati Gas and Electric Company and Dravo Lime Company for the US Department of Energy at a pilot plant facility at the Miami Fort station of CG&E near Cincinnati, Ohio. The pilot plant scrubbed a slipstream of flue gas from Unit 7 a 530 MW coal-fired electric generating unit. Tests were conducted in three phases between April and December. The technology tested was wet scrubbing with Thiosorbic{reg_sign} magnesium-enhanced lime for SO{sub 2} removal and simultaneous NO scrubbing with ferrous EDTA, a metal chelate. Magnesium-enhanced lime-based wet scrubbing is used at 20 full-scale high-sulfur coal-fired electric generating units with a combined capacity of 8500 MW. Ferrous EDTA reacts with nitric oxide, NO, which comprises about 96% of NO{sub x} from coal-fired boilers. In this report, although not precise, NO and NO{sub x} are used interchangeably. A major objective of the tests was to combine NO{sub x} removal using ferrous EDTA, a developing technology, with SO{sub 2} removal using wet lime FGD, already in wide commercial use. If successful, this could allow wide application of this NO{sub x} removal technology. Volume 2 covers: description and results of NO{sub x} removal tests; and description and results of waste characterization studies.

  3. Removal of Technetium, Carbon Tetrachloride, and Metals from DOE Properties - Final Report

    SciTech Connect

    Mallouk, Thomas E.

    2000-09-01

    This research is a three year project involving close collaboration between chemists at Pennsylvania State University and materials scientists at Pacific Northwest National Laboratory (PNNL). The goal of the project is the development and characterization of supported reducing agents, and solid waste forms derived from them, which will be effective in remediation of aqueous wastes. The work follows the recent discovery that zero-valent metals, such as iron, are effective decontaminants for waste streams containing chlorinated hydrocarbons. Preliminary data, obtained at Penn State and elsewhere, have shown that the same strategy will be effective in reducing soluble compounds containing toxic metals (technetium, lead, mercury, and chromium) to insoluble forms. The Penn State group has prepared a new class of powerful reducing agents, called Ferragels, which consist of finely divided zero-valent metals on high surface area supports. Because the rate of the surface oxidation-reduction reaction depends on available surface area, Ferragels are more effective in every case tested to date than unsupported metals. The project will further develop and investigate the application of these composite materials to problems relevant to the DOE-EM mission, namely the detoxification of waste streams containing technetium, carbon tetrachloride, and toxic metal ions. The Penn State group will work closely with the PNNL group to prepare materials that are compatible with the highly corrosive liquid fraction of Hanford site tank waste, to conduct tests with waste simulants containing technetium, and to formulate and characterize vitrified waste forms derived from these materials.

  4. Photoactivated metal removal

    SciTech Connect

    Nimlos, M.R.; Filley, J.; Ibrahim, M.A.; Watt, A.S.; Blake, D.M.

    1999-07-01

    The authors propose the use of photochromic dyes as light activated switches to bind and release metal ions. This process, which can be driven by solar energy, can be used in environmental and industrial processes to remove metals from organic and aqueous solutions. Because the metals can be released from the ligands when irradiated with visible light, regeneration of the ligands and concentration of the metals may be easier than with conventional ion exchange resins. Thus, the process has the potential to be less expensive than currently used metal extraction techniques. In this paper, the authors report on their studies of the metal binding of spirogyran dyes and the hydrolytic stability of these dyes. They have prepared a number of spirogyrans and measured their binding constants for calcium and magnesium. They discuss the relationship of the structure of the dyes to their binding strengths. These studies are necessary towards determining the viability of this technique.

  5. Removal of heteroatoms and metals from heavy oils by bioconversion processes. CRADA final report

    SciTech Connect

    Kaufman, E N; Borole, A P

    1999-03-01

    The objective of this Cooperative research and Development Agreement project between Oak Ridge National Laboratory ( O W ) and Baker Performance Chemicals (BPC), Chevron, Energy BioSystems, Exxon, UNOCAL and Texaco is to investigate the biological desukrization of crude oil. Biological removal of organic s&%r fiom crude oil offers an attractive alternative to conventional thermochemical treatment due to the mild operating conditions afforded by the biocatalyst. In order for biodesulfbrization to realize commercial success, reactors must be designed which allow for sufficient liquid / liquid and gas / liquid mass transfer while simultaneously reducing operating costs. To this end we have been developing advanced bioreactors for biodesufirization and have been studying their performance using both actual crude oil as well as more easily characterized model systems.

  6. Modeling heavy-metal removal in wetlands (final report). Master's thesis

    SciTech Connect

    Light, R.N.

    1992-05-01

    A computer model has been developed to simulate the fate transport of heavy metals introduced to a wetland ecosystem. Modeled water quality variables include plankton biomass and productivity; macrophyte (Nuiumbo lutea) biomass; total phosphorus in the water column; dissolved copper in the water column and sediments; particulate copper in the water column and sediments; and suspended solids. These variables directly affect the modeled rate of copper uptake by macrophytes, and the rate of copper recycling as a function of the decomposition of copper-laden biomass litter. The model was calibrated using total phosphorus and chlorophyll-a data from the Old Woman Creek Wetland in Ohio. Verification of the model was achieved using data on the copper content of the macrophyte Nelumbo lutea. The effects of harvesting copper-laden biomass on the longevity of the wetland ecosystem were also evaluated.

  7. Metals removal from spent salts

    DOEpatents

    Hsu, Peter C.; Von Holtz, Erica H.; Hipple, David L.; Summers, Leslie J.; Brummond, William A.; Adamson, Martyn G.

    2002-01-01

    A method and apparatus for removing metal contaminants from the spent salt of a molten salt oxidation (MSO) reactor is described. Spent salt is removed from the reactor and analyzed to determine the contaminants present and the carbonate concentration. The salt is dissolved in water, and one or more reagents may be added to precipitate the metal oxide and/or the metal as either metal oxide, metal hydroxide, or as a salt. The precipitated materials are filtered, dried and packaged for disposal as waste or can be immobilized as ceramic pellets. More than about 90% of the metals and mineral residues (ashes) present are removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be spray-dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration <20% require further clean-up using an ion exchange column, which yields salt solutions that contain less than 1.0 ppm of contaminants.

  8. Metal removal by natural glauconite

    SciTech Connect

    Lu, W.; Smith, E.H.

    1995-12-31

    Removal of cadmium, lead, zinc copper, and chromium by a natural clay mineral, glauconite, was studied using potentiometric titrations, continuous flow-through column reactors, and batch adsorption-desorption experiments and successfully modeled by surface complexation models (SCM). Potentiometric titration data were modeled using a simple single-site non-electrostatic model and a multi-site constant capacitance model. Important model parameters, such as surface site density and surface protonation-deprotonation constants, were also derived by fitting the titration data to SCMs. The metals compete effectively with protons for the surface sites, and bind strongly onto the surface of the mineral as shown by the significant shift in the potentiometric titration curves with or without these metals in glauconite suspension. Metal removal is primarily controlled by pH and can be modeled successfully by a single-site triple layer model along with the pH speciation of the metals. The successful application of SCMs in modeling titration and adsorption data of glauconite indicates that surface complexation is the primary mechanism in metal removal. Therefore, the theory of surface complexation can be used in predicting metal removal under different conditions such as pH, ionic strength, sorbent/sorbate ratio, and surface site density. The high metal removal capacities of glauconite are considered to be promising in treating some waste water.

  9. REMOVAL OF METALS IN COMBINED TREATMENT SYSTEMS

    EPA Science Inventory

    This project assessed the variables influencing the removal of eight metals through combined industrial-municipal treatment plants. The eight metals investigated were: aluminum, cadmium, chromium, copper, iron, lead, nickel, and zinc. The metals were studied at subtoxic influent ...

  10. Development and evaluation of Mn oxide-coated composite adsorbent for the removal and recovery of heavy metals from coal processing wastewater. Final report, December 1995

    SciTech Connect

    Fan, Huan Jung; Anderson, P.R.

    1995-12-31

    The overall objective of this research was to evaluate a Mn oxide-coated granular activated carbon (MnGAC) for the removal and recovery of metals from wastewaters. The composite adsorbent was prepared by coating M-n-oxide onto granular activated carbon. Three coating methods (adsorption, precipitation, and dry oxidation) were developed and studied in this research. The adsorbent (MnTOG) prepared by a dry oxidation method had the highest Cu(II) adsorption capacity of the three synthesis methods. In multiple adsorption/regeneration cycle tests, MnTOG had better Cu(II) removal relative to those adsorbents prepared by other methods. MnTOG had the ability to remove Cu(II) and Cd(II) to trace level (< 4 ug/L) in a column process at least through 3000 and 1400 BV, respectively. Cd(II) removal was hindered by the presence of Cu(II). However, Cu(II) removal was only slightly reduced by the presence of Cd(II). Cu(II) adsorption in batch and fixed-bed processes onto MnTOG was successfully modeled with a homogeneous surface diffusion model (HSDM). However, the HSDM could only successfully describe the adsorption of Cd(II) onto MnTOG in the batch process, but not the fixed-bed process. M-n oxide can be deposited on GAC to create a composite adsorbent with an increased Cu(II) or Cd(II) adsorption capacity. Composite adsorbent (MnGAC) has the potential to become an efficient way to remove metals from metal contaminated wastewater.

  11. Removal of metal ions from aqueous solution

    SciTech Connect

    Jackson, P.J.; Delhaize, E.; Robinson, N.J.; Unkefer, C.J.; Furlong, C.

    1990-03-20

    This patent describes a method of removing heavy metals from aqueous solution, a composition of matter used in effecting the removal, and apparatus used in effecting the removal. One or more of the polypeptides, poly ({gamma}-glutamylcysteinyl)glycines, is immobilized on an inert material in particulate form. Upon contact with an aqueous solution containing heavy metals, the polypeptides sequester the metals, removing them from the solution. There is selectivity of poly ({gamma}-glutamylcysteinyl)glycines having a particular number of monomer repeat units for particular metals. The polypeptides are easily regenerated by contact with a small amount of an organic acid, so that they can be used again to remove heavy metals from solution. This also results in the removal of the metals from the column in a concentrated form.

  12. Removal of metal ions from aqueous solution

    DOEpatents

    Jackson, Paul J.; Delhaize, Emmanuel; Robinson, Nigel J.; Unkefer, Clifford J.; Furlong, Clement

    1990-01-01

    A method of removing heavy metals from aqueous solution, a composition of matter used in effecting said removal, and apparatus used in effecting said removal. One or more of the polypeptides, poly (.gamma.-glutamylcysteinyl)glycines, is immobilized on an inert material in particulate form. Upon contact with an aqueous solution containing heavy metals, the polypeptides sequester the metals, removing them from the solution. There is selectivity of poly (.gamma.-glutamylcysteinyl)glycines having a particular number of monomer repeat units for particular metals. The polypeptides are easily regenerated by contact with a small amount of an organic acid, so that they can be used again to remove heavy metals from solution. This also results in the removal of the metals from the column in a concentrated form.

  13. Removal of metal ions from aqueous solution

    SciTech Connect

    Jackson, P.J.; Delhaize, E.; Robinson, N.J.; Unkefer, C.J.; Furlong, C.

    1988-08-26

    A method of removing heavy metals from aqueous solution, a composition of matter used in effecting said removal, and apparatus used in effecting said removal. One or more of the polypeptides, poly ({gamma}-glutamylcysteinyl)glycines, is immobilized on an inert material in particulate form. Upon contact with an aqueous solution containing heavy metals, the polypeptides sequester the metals, removing them from the solution. There is selectivity of poly ({gamma}-glutamylcysteinyl)glycines having a particular number of monomer repeat units for particular metals. The polypeptides are easily regenerated by contact with a small amount of an organic acid, so that they can be used again to remove heavy metals from solution. This also results in the removal of the metals from the column in a concentrated form.

  14. Removal of metal ions from aqueous solution

    SciTech Connect

    Jackson, P.J.; Delhaize, E.; Robinson, N.J.; Unkefer, C.J.; Furlong, C.

    1990-11-13

    A method is disclosed of removing heavy metals from aqueous solution, a composition of matter used in effecting said removal, and apparatus used in effecting said removal. One or more of the polypeptides, poly ([gamma]glutamylcysteinyl)glycines, is immobilized on an inert material in particulate form. Upon contact with an aqueous solution containing heavy metals, the polypeptides sequester the metals, removing them from the solution. There is selectivity of poly ([gamma]glutamylcysteinyl)glycines having a particular number of monomer repeat unit for particular metals. The polypeptides are easily regenerated by contact with a small amount of an organic acid, so that they can be used again to remove heavy metals from solution. This also results in the removal of the metals from the column in a concentrated form. 1 fig.

  15. Removal of metal ions from aqueous solution

    SciTech Connect

    Jackson, Paul J.; Delhaize, Emmanuel; Robinson, Nigel J.; Unkefer, Clifford J.; Furlong, Clement

    1990-11-13

    A method of removing heavy metals from aqueous solution, a composition of matter used in effecting said removal, and apparatus used in effecting said removal. One or more of the polypeptides, poly (.gamma.-glutamylcysteinyl)glycines, is immobilized on an inert material in particulate form. Upon contact with an aqueous solution containing heavy metals, the polypeptides sequester the metals, removing them from the solution. There is selectivity of poly (.gamma.-glutamylcysteinyl)glycines having a particular number of monomer repeat unit for particular metals. The polypeptides are easily regenerated by contact with a small amount of an organic acid, so that they can be used again to remove heayv metals from solution. This also results in the removal of the metals from the column in a concentrated form.

  16. Metals removal and recovery from municipal sludge

    SciTech Connect

    Jenkins, R.L.; Scheybeler, B.J.; Smith, M.L.; Baird, R.; Lo, M.P.; Haug, R.T.

    1981-01-01

    The feasibility of metals removal from municipal sludges that may be disposed of on agricultural land was studied. Heavy metal accumulation in such vegetables as lettuce and heavy metal toxicity to such crops as oats, beans, corn, and radishes is of concern. The purpose of the study was to assess metal removal systems for sludges obtained from the Joint Water Pollution Control Plant, Carson, Calif. Primary sludge, waste activated sludge, and their anaerobically digested counterparts were dosed with sulfuric acid and the chelating agent, ethylenediaminetetraacetic acid (EDTA), to effect metal solubilization. Seven metals were examined for removal from sludge: Cd, Cr, Cu, Fe, Pb, Ni, and Zn. Recovery of metals from the sludges was also examined. Using an acid dosage to effect pH decrease to pH 2 and a-stirring time of 24 hours, the removal efficiencies for Fe, Zn, Ni, and Cr were found to be upwards of 75%. Removal efficiencies for Pb and Cd were less, at about 30 to 70%. At less than 10%, Cu was hardly removed. Metal extraction using EDTA gave slightly higher removal efficiencies for Cd, Pb, and Cu. The recovery of solubilized metals from solution with lime was very successful at greater than 90% efficiencies. Examination of the dewaterability of the acid-treated sludge found no significant difference between treated and untreated. Preliminary estimates indicated that about 0.5 metric ton of acid would be required for each dry metric ton of sludge solids to effect significant metal removal of better than 50% of the cadmium and 33% of the lead. To precipitate the metals from the acid filtrate, 1 metric ton of lime per dry metric ton of sludge would be needed. Considering the chemical costs and metal removal efficiency by sludge acidification, it would seem that industrial source control would be a more practical approach, although its full economic impact on the industries has not been estimated.

  17. Extraction process for removing metallic impurities from alkalide metals

    DOEpatents

    Royer, L.T.

    1987-03-20

    A development is described for removing metallic impurities from alkali metals by employing an extraction process wherein the metallic impurities are extracted from a molten alkali metal into molten lithium metal due to the immiscibility of the alkali metals in lithium and the miscibility of the metallic contaminants or impurities in the lithium. The purified alkali metal may be readily separated from the contaminant-containing lithium metal by simple decanting due to the differences in densities and melting temperatures of the alkali metals as compared to lithium.

  18. Extraction process for removing metallic impurities from alkalide metals

    DOEpatents

    Royer, Lamar T.

    1988-01-01

    A development is described for removing metallic impurities from alkali metals by employing an extraction process wherein the metallic impurities are extracted from a molten alkali metal into molten lithium metal due to the immiscibility of the alkali metals in lithium and the miscibility of the metallic contaminants or impurities in the lithium. The purified alkali metal may be readily separated from the contaminant-containing lithium metal by simple decanting due to the differences in densities and melting temperatures of the alkali metals as compared to lithium.

  19. Catalyst regeneration process including metal contaminants removal

    DOEpatents

    Ganguli, Partha S.

    1984-01-01

    Spent catalysts removed from a catalytic hydrogenation process for hydrocarbon feedstocks, and containing undesired metals contaminants deposits, are regenerated. Following solvent washing to remove process oils, the catalyst is treated either with chemicals which form sulfate or oxysulfate compounds with the metals contaminants, or with acids which remove the metal contaminants, such as 5-50 W % sulfuric acid in aqueous solution and 0-10 W % ammonium ion solutions to substantially remove the metals deposits. The acid treating occurs within the temperature range of 60.degree.-250.degree. F. for 5-120 minutes at substantially atmospheric pressure. Carbon deposits are removed from the treated catalyst by carbon burnoff at 800.degree.-900.degree. F. temperature, using 1-6 V % oxygen in an inert gas mixture, after which the regenerated catalyst can be effectively reused in the catalytic process.

  20. 8 CFR 241.1 - Final order of removal.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... OF ALIENS ORDERED REMOVED Post-hearing Detention and Removal § 241.1 Final order of removal. An order of removal becomes final in accordance with 8 CFR 1241.1. ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Final order of removal. 241.1 Section...

  1. 8 CFR 241.1 - Final order of removal.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... OF ALIENS ORDERED REMOVED Post-hearing Detention and Removal § 241.1 Final order of removal. An order of removal becomes final in accordance with 8 CFR 1241.1. ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Final order of removal. 241.1 Section...

  2. Removal of metals in constructed wetlands

    SciTech Connect

    Crites, R.W.; Watson, R.C.; Williams, C.R.

    1996-12-31

    Trace metals are difficult to remove from municipal wastewater by conventional wastewater treatment methods. Constructed wetlands have the potential to trap and remove metals from the water column. Long term removal is expected to occur by accumulation and burial in the plant detritus in a manner similar to the removal of phosphorus. Few data are available in the literature on removal of metals by constructed wetlands. A free water surface constructed wetland at Sacramento Regional Wastewater Treatment Plant treating secondary municipal effluent has been operating since the spring of 1994. Removal data for 13 metals are presented for the period from August 1994 to May 1995. About 3,785 m{sup 3}/d (1 mgd) of pure oxygen activated sludge effluent, disinfected using UV light, is further treated through a 8 ha (20 acre) constructed wetlands Ten separate, parallel treatment cells are available to demonstrate the effects of detention time, vegetation management, and application frequency on the removal of metals, organics and ammonia. Detention time can be varied from 3 to 13 days by varying the flow and the water depth. The vegetation, primarily bulrush with some cattails, will be managed by different techniques to minimize mosquito production. Application frequency varies from continuous flow to batch flow (1 to 2 days of loading with 1 day of discharge).

  3. Process for removing metals from water

    DOEpatents

    Napier, J.M.; Hancher, C.M.; Hackett, G.D.

    1987-06-29

    A process for removing metals from water including the steps of prefiltering solids from the water, adjusting the pH to between about 2 and 3, reducing the amount of dissolved oxygen in the water, increasing the pH to between about 6 and 8, adding water-soluble sulfide to precipitate insoluble sulfide- and hydroxide-forming metals, adding a containing floc, and postfiltering the resultant solution. The postfiltered solution may optionally be eluted through an ion exchange resin to remove residual metal ions. 2 tabs.

  4. Process for removing metals from water

    DOEpatents

    Napier, John M.; Hancher, Charles M.; Hackett, Gail D.

    1989-01-01

    A process for removing metals from water including the steps of prefiltering solids from the water, adjusting the pH to between about 2 and 3, reducing the amount of dissolved oxygen in the water, increasing the pH to between about 6 and 8, adding water-soluble sulfide to precipitate insoluble sulfide- and hydroxide-forming metals, adding a flocculating agent, separating precipitate-containing floc, and postfiltering the resultant solution. The postfiltered solution may optionally be eluted through an ion exchange resin to remove residual metal ions.

  5. Removal of heavy metals from waste streams

    SciTech Connect

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

    1988-07-19

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

  6. 8 CFR 1241.1 - Final order of removal.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Final order of removal. 1241.1 Section 1241... REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Post-hearing Detention and Removal § 1241.1 Final order of removal. An order of removal made by the immigration judge at the conclusion...

  7. Membranes Remove Metal Ions Fron Industrial Liquids

    NASA Technical Reports Server (NTRS)

    Hsu, W. P. L.; May, C.

    1983-01-01

    Use of membrane films affords convenient and economical alternative for removing and recovering metal cations present in low concentrations from large quantities of liquid solutions. Possible applications of membrane films include use in analytical chemistry for determination of small amounts of toxic metallic impurities in lakes, streams, and municipal effluents. Also suitable for use as absorber of certain pollutant gases and odors present in confined areas.

  8. Heavy metal removal and recovery using microorganisms

    SciTech Connect

    Wilde, E.W. ); Benemann, J.R. , Pinole, CA )

    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.

  9. 8 CFR 1241.1 - Final order of removal.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Final order of removal. 1241.1 Section 1241.1 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Post-hearing Detention and Removal § 1241.1 Final order of removal. An order...

  10. 8 CFR 1241.1 - Final order of removal.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Final order of removal. 1241.1 Section 1241... Final order of removal. An order of removal made by the immigration judge at the conclusion of... judge orders an alien removed in the alien's absence, immediately upon entry of such order; or (f) If...

  11. 8 CFR 1241.1 - Final order of removal.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Final order of removal. 1241.1 Section 1241... Final order of removal. An order of removal made by the immigration judge at the conclusion of... judge orders an alien removed in the alien's absence, immediately upon entry of such order; or (f) If...

  12. 8 CFR 1241.1 - Final order of removal.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Final order of removal. 1241.1 Section 1241... Final order of removal. An order of removal made by the immigration judge at the conclusion of... judge orders an alien removed in the alien's absence, immediately upon entry of such order; or (f) If...

  13. Removal of Retired Alkali Metal Test Systems

    SciTech Connect

    BREHM, W.F.

    2003-01-01

    This paper describes the successful effort to remove alkali metals, alkali metal residues, and piping and structures from retired non-radioactive test systems on the Hanford Site. These test systems were used between 1965 and 1982 to support the Fast Flux Test Facility and the Liquid Metal Fast Breeder Reactor Program. A considerable volume of sodium and sodium-potassium alloy (NaK) was successfully recycled to the commercial sector; structural material and electrical material such as wiring was also recycled. Innovative techniques were used to safely remove NaK and its residues from a test system that could not be gravity-drained. The work was done safely, with no environmental issues or significant schedule delays.

  14. Removal of Retired Alkali Metal Test Systems

    SciTech Connect

    Brehm, W. F.; Church, W. R.; Biglin, J. W.

    2003-02-26

    This paper describes the successful effort to remove alkali metals, alkali metal residues, and piping and structures from retired non-radioactive test systems on the Hanford Site. These test systems were used between 1965 and 1982 to support the Fast Flux Test Facility and the Liquid Metal Fast Breeder Reactor Program. A considerable volume of sodium and sodium-potassium alloy (NaK) was successfully recycled to the commercial sector; structural material and electrical material such as wiring was also recycled. Innovative techniques were used to safely remove NaK and its residues from a test system that could not be gravity-drained. The work was done safely, with no environmental issues or significant schedule delays.

  15. Material Removes Heavy Metal Ions From Water

    NASA Technical Reports Server (NTRS)

    Philipp, Warren H., Jr.; Street, Kenneth W.; Hill, Carol; Savino, Joseph M.

    1995-01-01

    New high capacity ion-exchange polymer material removes toxic metal cations from contaminated water. Offers several advantages. High sensitivities for such heavy metals as lead, cadmium, and copper and capable of reducing concentrations in aqueous solutions to parts-per-billion range. Removes cations even when calcium present. Material made into variety of forms, such as thin films, coatings, pellets, and fibers. As result, adapted to many applications to purify contaminated water, usually hard wherever found, whether in wastewater-treatment systems, lakes, ponds, industrial plants, or homes. Another important feature that adsorbed metals easily reclaimed by either destructive or nondestructive process. Other tests show ion-exchange polymer made inexpensively; easy to use; strong, flexible, not easily torn; and chemically stable in storage, in aqueous solutions, and in acidic or basic solution.

  16. Removal of Metallic Iron on Oxide Slags

    NASA Astrophysics Data System (ADS)

    Shannon, George N.; Fruehan, R. J.; Sridhar, Seetharaman

    2009-10-01

    It is possible, in some cases, for ground coal particles to react with gasifier gas during combustion, allowing the ash material in the coal to form phases besides the expected slag phase. One of these phases is metallic iron, because some gasifiers are designed to operate under a reducing atmosphere ({p_{O2}} of approximately 10-4 atm). Metallic iron can become entrained in the gas stream and deposit on, and foul, downstream equipment. To improve the understanding of the reaction between different metallic iron particles and gas, which eventually oxidizes them, and the slag that the resulting oxide dissolves in, the kinetics of iron reaction on slag were predicted using gas-phase mass-transfer limitations for the reaction and were compared with diffusion in the slag; the reaction itself was observed under confocal scanning laser microscopy. The expected rates for iron droplet removal are provided based on the size and effective partial pressure of oxygen, and it is found that decarburization occurs before iron reaction, leading to an extra 30- to 100-second delay for carbon-saturated particles vs pure iron particles. A pure metallic iron particle of 0.5 mg should be removed in about 220 seconds at 1400 °C and in 160 seconds at 1600 °C.

  17. Removal of metallic iron on oxide slags

    SciTech Connect

    Shannon, G.N.; Fruehan, R.J.; Sridhar, S.

    2009-10-15

    It is possible, in some cases, for ground coal particles to react with gasifier gas during combustion, allowing the ash material in the coal to form phases besides the expected slag phase. One of these phases is metallic iron, because some gasifiers are designed to operate under a reducing atmosphere (pO{sub 2}) of approximately 10{sup -4} atm). Metallic iron can become entrained in the gas stream and deposit on, and foul, downstream equipment. To improve the understanding of the reaction between different metallic iron particles and gas, which eventually oxidizes them, and the slag that the resulting oxide dissolves in, the kinetics of iron reaction on slag were predicted using gas-phase mass-transfer limitations for the reaction and were compared with diffusion in the slag; the reaction itself was observed under confocal scanning laser microscopy. The expected rates for iron droplet removal are provided based on the size and effective partial pressure of oxygen, and it is found that decarburization occurs before iron reaction, leading to an extra 30- to 100-second delay for carbon-saturated particles vs pure iron particles. A pure metallic iron particle of 0.5 mg should be removed in about 220 seconds at 1400{sup o}C and in 160 seconds at 1600{sup o}C.

  18. Aquatic macrophytes potential for the simultaneous removal of heavy metals (Buenos Aires, Argentina).

    PubMed

    Miretzky, Patricia; Saralegui, Andrea; Cirelli, Alicia Fernández

    2004-11-01

    Heavy metal removal from water has been approached by using different technologies. Phytotechnologies, with an increasing development during the last two decades, involve using plants for metal removal. Three autochthonous floating macrophytes, common in pampean shallow lakes (Argentina), Pista stratiotes, Spirodela intermedia and Lemna minor were used in laboratory experiences for the simultaneously removal of several heavy metals (Fe, Cu, Zn, Mn, Cr and Pb) resulting from anthropogenic activity, in order to simulate a naturally polluted environment. The experiences were performed for different concentrations of metals along 15 days. High metal removal percentages were obtained for the 3 species and metals. L. minor did not survive the conditions of the experiment. High correlation between the final water and the macrophytes metal concentration was obtained, deviations were due to PbCrO(4) precipitation. The rate of metal uptake was dependent on the metal concentration for the 3 species studied. PMID:15488590

  19. Process for removing technetium from iron and other metals

    DOEpatents

    Leitnaker, J.M.; Trowbridge, L.D.

    1999-03-23

    A process for removing technetium from iron and other metals comprises the steps of converting the molten, alloyed technetium to a sulfide dissolved in manganese sulfide, and removing the sulfide from the molten metal as a slag. 4 figs.

  20. Process for removing technetium from iron and other metals

    DOEpatents

    Leitnaker, James M.; Trowbridge, Lee D.

    1999-01-01

    A process for removing technetium from iron and other metals comprises the steps of converting the molten, alloyed technetium to a sulfide dissolved in manganese sulfide, and removing the sulfide from the molten metal as a slag.

  1. Separation and removal of metal cyanides

    SciTech Connect

    Hammen, R.F.; Van Der Sluys, W.G.

    1995-09-01

    Metal ion capture media have been developed which are capable of rapidly and effectively reducing metal cyanide concentrations to sub- part per million levels. These media were developed to meet the growing need for compliance with increasingly stringent disposal regulations and the need for cost-effective treatment of metal cyanide waste streams produced by the gold mining and electroplating industries. The extraction media are produced by modifying porous silica with covalently attached, long, and hydrophilic spacer molecules. The termini of the spacer molecules are activated and coupled with a variety of ion exchange and chelating reagents. By placing the functionality away from the surface of the solid support, a combination of the benefits of solution phase equilibration kinetics and heterogeneous support media is obtained. This paper describes column extraction tests performed with the media to remove iron, zinc, copper, and gold cyanide complexes from solution to levels below one part per million. Additional tests were performed with these columns to selectively extract these metal cyanides and/or selectively desorb the cyanide complexes from the media. One column was effective in extracting gold cyanide from solution and recovering the gold by elution with carbonate buffer. The other metal cyanides showed distinctively different adsorption isotherms. By using a combination of two extraction media chemistries, it is possible to separate gold cyanide from a complex solution of mixed metal cyanide species.

  2. Modeling heavy metal removal in wetlands

    SciTech Connect

    Lung, W.S.; Light, R.N.

    1994-12-31

    Although the use of wetland ecosystems to purify water has gained increased attention only recently, it has been recognized as a wastewater treatment technique for centuries. While considerable research has occurred to quantify the nutrient (nitrogen and phosphorus) removal mechanisms of wetlands, relatively few investigators have focused on the mechanisms of heavy metal removal and uptake by wetland sediments and plants. The quantification of the assimilative capacity of heavy metals by wetland ecosystems is a critical component in the design and use of wetlands for this purpose. A computer model has been developed to simulate the fate and transport of heavy metals introduced to a wetland ecosystem. Modeled water quality variables include phytoplankton biomass and productivity; macrophyte (Nulumbo lutea) biomass; total phosphorus in the water column; dissolved copper in the water column and sediments; particulate copper in the water column and sediments; and suspended solids. These variables directly affect the calculated rate of copper uptake by macrophytes, and the rate of copper recycling as a function of the decomposition of copper-laden biomass litter. The model was calibrated using total phosphorus and chlorophyll a data from the Old Woman Creek Wetland in Ohio. Verification of the model was achieved using data on the copper content of the macrophyte Nelumbo lutea.

  3. A process for containment removal and waste volume reduction to remediate groundwater containing certain radionuclides, toxic metals and organics. Final report

    SciTech Connect

    Buckley, L.P.; Killey, D.R.W.; Vijayan, S.; Wong, P.C.F.

    1992-09-01

    A project to remove groundwater contaminants by an improved treatment process was performed during 1990 October--1992 March by Atomic Energy of Canada Limited for the United States Department of Energy, managed by Argonne National Laboratory. The goal was to generate high-quality effluent while minimizing secondary waste volume. Two effluent target levels, within an order of magnitude, or less than the US Drinking Water Limit, were set to judge the process effectiveness. The program employed mixed waste feeds containing cadmium, uranium, lead, iron, calcium, strontium-85-90, cesium-137, benzene and trichlorethylene in simulated and actual groundwater and soil leachate solutions. A combination of process steps consisting of sequential chemical conditioning, cross-flow microfiltration and dewatering by low temperature-evaporation, or filter pressing were effective for the treatment of mixed waste having diverse physico-chemical properties. A simplified single-stage version of the process was implemented to treat ground and surface waters contaminated with strontium-90 at the Chalk River Laboratories site. Effluent targets and project goals were met successfully.

  4. Ionic liquid incorporating thiosalicylate for metal removal

    NASA Astrophysics Data System (ADS)

    Wilfred, Cecilia Devi; Mustafa, Fadwa Babiker; Romeli, Fatimah Julia

    2012-09-01

    Ionic liquids are a class of organic molten salts "designer solvents" that are composed totally of anions (inorganic and organic polyatomic) and organic cations. The replacement of volatile organic solvents from a separation process is of utmost importance since the use of a large excess of these solvents is hazardous and creates ecological problem. The new method for metal ion extraction is by using task-specific ionic liquids such as ionic liquids which incorporate thiosalicylate functionality. This paper looks at producing a new cluster of ionic liquids which incorporates thiosalicylate with pyridinium cation. Its thermophysical properties such as density and viscosity in single and binary mixtures are studied. The ionic liquids' capability in metal removal processes is evaluated.

  5. Compositions and methods for removal of toxic metals and radionuclides

    NASA Technical Reports Server (NTRS)

    Cuero, Raul G. (Inventor); McKay, David S. (Inventor)

    2007-01-01

    The present invention relates to compositions and methods for the removal of toxic metals or radionuclides from source materials. Toxic metals may be removed from source materials using a clay, such as attapulgite or highly cationic bentonite, and chitin or chitosan. Toxic metals may also be removed using volcanic ash alone or in combination with chitin or chitosan. Radionuclides may be removed using volcanic ash alone or in combination with chitin or chitosan.

  6. Genital incarceration with metal rings: their safe removal.

    PubMed

    Schuster, G; Stockmal, P

    1999-06-01

    Strangulation of the genitalia with constricting metal bands presents a difficult problem with removal. We report the easy and safe removal by cutting the metal bands in two places using a hand-held Dremel Moto-Tool [corrected] with a metal cutting disk. PMID:10458669

  7. Etchback smear removal process characterization. Final report

    SciTech Connect

    Richardson, J.H.

    1981-03-01

    A study evaluated variable limits for each chemical solution used in etchback smear removal on multilayer printed wiring boards (MLPWBs) to determine variables' influence on etchback behavior. Etchback smear removal is essential to fabricate about 40 different multilayer parts. However, erratic etchback behavior contributes to reduced yields among multilayer parts. The study, conducted on 172 multilayer printed wiring boards in 43 test runs, indicated that chemical interaction may not be a principal influence on etchback behavior. Study results also indicated that slight changes in process variables did not influence the presence of recessed conductors. The results verified the adequacy of existing tolerances on main process variables to produce uniformly etched holes.

  8. Tribological properties of silicon carbide in metal removal process

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Buckley, D. H.

    1980-01-01

    This paper reviews material properties of adhesion, friction and wear of single-crystal silicon carbide in contact with metals and alloys involved in a metal removal process such as grinding. The tribological properties in the metal removal processes are divided into properties which remove metal by adhesion between sliding surfaces, and metal removal by silicon carbide sliding against a metal, indenting it, and plowing a series of grooves or furrows. The paper also deals with fracture and deformation characteristics of the silicon carbide surface; the adhesion, friction and metal transfer to silicon carbide is related to the relative chemical activity of the metals. Atomic size and content of alloying elements play a dominant role in controlling adhesion and friction properties of alloys. The friction and abrasive wear decrease as the shear strength of the bulk metal increases.

  9. Metal Cutting for Large Component Removal

    SciTech Connect

    Hulick, Robert M.

    2008-01-15

    Decommissioning of commercial nuclear power plants presents technological challenges. One major challenge is the removal of large components mainly consisting of the reactor vessel, steam generators and pressurizer. In order to remove and package these large components nozzles must be cut from the reactor vessel to precise tolerances. In some cases steam generators must be segmented for size and weight reduction. One innovative technology that has been used successfully at several commercial nuclear plant decommissioning is diamond wire sawing. Diamond wire sawing is performed by rotating a cable with diamond segments attached using a flywheel approximately 24 inches in diameter driven remotely by a hydraulic pump. Tension is provided using a gear rack drive which also takes up the slack in the wire. The wire is guided through the use of pulleys keeps the wire in a precise location. The diamond wire consists of 1/4 inch aircraft cable with diamond beads strung over the cable separated by springs and brass crimps. Standard wire contains 40 diamond beads per meter and can be made to any length. Cooling the wire and controlling the spread of contamination presents significant challenges. Under normal circumstances the wire is cooled and the cutting kerf cleaned by using water. In some cases of reactor nozzle cuts the use of water is prohibited because it cannot be controlled. This challenge was solved by using liquid Carbon Dioxide as the cooling agent. The liquid CO{sub 2} is passed through a special nozzle which atomizes the liquid into snowflakes which is introduced under pressure to the wire. The snowflakes attach to the wire keeping it cool and to the metal shavings. As the CO{sub 2} and metal shavings are released from the wire due to its fast rotation, the snowflakes evaporate leaving only the fine metal shavings as waste. Secondary waste produced is simply the small volume of fine metal shavings removed from the cut surface. Diamond wire sawing using CO{sub 2

  10. Heavy metal removal using peat/wetland treatment

    SciTech Connect

    Murawski, S.

    1994-12-31

    The purpose of this paper is to present an overview of the mechanisms and application of a peat/wetland treatment system for heavy metal removal from wastewater. The mechanisms involved in the removal of heavy metals are complex and difficult to predict, however, peat has been proven to be an effective medium to remove metals. The successful design of a peat/wetland treatment system for acid mine drainage is presented to emphasize the low cost and minimal maintenance involved in this passive metal removal technique.

  11. Consequential species of heavy metals. Final report

    SciTech Connect

    Yousef, Y.A.; Harper, H.H.; Wiseman, L.; Bateman, M.

    1985-02-01

    Highway stormwater runoff contains significantly higher concentrations of trace metals, particularly Pb, Zn, Cd, Cu, Cr, Fe, and Ni than the water samples from adjacent receiving water bodies. The metals associated with highway runoff tend to be detoxified by the organic content and chemical conditions of natural waters and sediments. Most of the metals are retained by the bottom sediments on a permanent basis if aerobic conditions and high redax-potential (Eh) values are maintained. Retention/detention ponds similar to the Maitland Pond site are very effective in nutrient and heavy metal removal from highway runoff.

  12. Method for removing metals from a cleaning solution

    DOEpatents

    Deacon, Lewis E.

    2002-01-01

    A method for removing accumulated metals from a cleaning solution is provided. After removal of the metals, the cleaning solution can be discharged or recycled. The process manipulates the pH levels of the solution as a means of precipitating solids. Preferably a dual phase separation at two different pH levels is utilized.

  13. 7 CFR 3201.104 - Metal cleaners and corrosion removers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...) Definition. (1) Products that are designed to clean and remove grease, oil, dirt, stains, soils, and rust..., dirt, stains, and soils from stainless steel surfaces. (iii) Other metal cleaners. Products that are designed to clean and remove grease, oil, dirt, stains, and soils from metal surfaces other than...

  14. Precision metal occlusal surfaces for removable partial dentures.

    PubMed

    Barco, M T; Synnott, S A

    1989-01-01

    The prosthodontist is often limited in developing the desired occlusal pattern when integrating removable partial dentures with natural dentitions or fixed partial dentures. A technique that allows the development of an esthetic, accurate metal occlusal surface for a removable partial denture is described. The occlusion developed allows an occlusal harmony with the removable partial denture that is not possible with stock denture teeth or metal occlusal surfaces developed with stock denture teeth. PMID:2700630

  15. Concurrent removal and accumulation of heavy metals by the three aquatic macrophytes.

    PubMed

    Mishra, Virendra Kumar; Tripathi, B D

    2008-10-01

    Under the present investigation effectiveness of three aquatic macrophytes Pistia stratiotes L. (water lettuce), Spirodela polyrrhiza W. Koch (duckweed) and Eichhornia crassipes were tested for the removal of five heavy metals (Fe, Zn, Cu, Cr and Cd). These plants were grown at three different concentrations (1.0, 2.0 and 5.0mgl(-1)) of metals in laboratory experiment. Result revealed high removal (>90%) of different metals during 15 days experiment. Highest removal was observed on 12th day of experiment, thereafter it decreased. Results revealed E. crassipes as the most efficient for the removal of selected heavy metals followed by P. stratiotes and S. polyrrhiza. Results from analysis confirmed the accumulation of different metals within the plant and a corresponding decrease of metals in the water. Significant correlations between metal concentration in final water and macrophytes were obtained. Plants have accumulated heavy metals in its body without the production of any toxicity or reduction in growth. Selected plants shown a wide range of tolerance to all of the selected metals and therefore can be used for large scale removal of heavy metals from waste water. PMID:18296043

  16. Simultaneous heavy metal removal mechanism by dead macrophytes.

    PubMed

    Miretzky, Patricia; Saralegui, Andrea; Fernández Cirelli, Alicia

    2006-01-01

    The use of dead, dried aquatic plants, for water removal of metals derived from industrial activities as a simple biosorbent material has been increasing in the last years. The mechanism of simultaneous metal removal (Cd2+, Ni2+, Cu2+, Zn2+ and Pb2+) by 3 macrophytes biomass (Spirodela intermedia, Lemna minor and Pistia stratiotes) was investigated. L. minor biomass presented the highest mean removal percentage and P. stratiotes the lowest for all metals tested. Pb2+ and Cd2+ were more efficiently removed by the three of them. The simultaneous metal sorption data were analysed according to Langmuir and Freundlich isotherms. Data fitted the Langmuir model only for Ni and Cd, but Freundlich isotherm for all metals tested, as it was expected. The K(F) values showed that Pb was the metal more efficiently removed from water solution. The adsorption process for the three species studied followed first order kinetics. The mechanism involved in biosorption resulted ion exchange between monovalent metals as counter ions present in the macrophytes biomass and heavy metal ions and protons taken up from water. No significant differences were observed in the metal exchange amounts while using multi-metal or individual metal solutions. PMID:15990152

  17. Removal of trace metal contaminants from potable water by electrocoagulation.

    PubMed

    Heffron, Joe; Marhefke, Matt; Mayer, Brooke K

    2016-01-01

    This study investigated the effects of four operational and environmental variables on the removal of trace metal contaminants from drinking water by electrocoagulation (EC). Removal efficiencies for five metals (arsenic, cadmium, chromium, lead and nickel) were compared under varying combinations of electrode material, post-treatment, water composition and pH. Iron electrodes out-performed aluminum electrodes in removing chromium and arsenic. At pH 6.5, aluminum electrodes were slightly more effective at removing nickel and cadmium, while at pH 8.5, iron electrodes were more effective for these metals. Regardless of electrode, cadmium and nickel removal efficiencies were higher at pH 8.5 than at pH 6.5. Post-EC treatment using membrane filtration (0.45 μm) enhanced contaminant removal for all metals but nickel. With the exception of lead, all metals exhibited poorer removal efficiencies as the ionic strength of the background electrolyte increased, particularly in the very high-solids synthetic groundwaters. Residual aluminum concentrations were lowest at pH 6.5, while iron residuals were lowest in low ionic strength waters. Both aluminum and iron residuals required post-treatment filtration to meet drinking water standards. EC with post-treatment filtration appears to effectively remove trace metal contaminants to potable water standards, but both reactor and source water parameters critically impact removal efficiency. PMID:27324564

  18. Removal of trace metal contaminants from potable water by electrocoagulation

    NASA Astrophysics Data System (ADS)

    Heffron, Joe; Marhefke, Matt; Mayer, Brooke K.

    2016-06-01

    This study investigated the effects of four operational and environmental variables on the removal of trace metal contaminants from drinking water by electrocoagulation (EC). Removal efficiencies for five metals (arsenic, cadmium, chromium, lead and nickel) were compared under varying combinations of electrode material, post-treatment, water composition and pH. Iron electrodes out-performed aluminum electrodes in removing chromium and arsenic. At pH 6.5, aluminum electrodes were slightly more effective at removing nickel and cadmium, while at pH 8.5, iron electrodes were more effective for these metals. Regardless of electrode, cadmium and nickel removal efficiencies were higher at pH 8.5 than at pH 6.5. Post-EC treatment using membrane filtration (0.45 μm) enhanced contaminant removal for all metals but nickel. With the exception of lead, all metals exhibited poorer removal efficiencies as the ionic strength of the background electrolyte increased, particularly in the very high-solids synthetic groundwaters. Residual aluminum concentrations were lowest at pH 6.5, while iron residuals were lowest in low ionic strength waters. Both aluminum and iron residuals required post-treatment filtration to meet drinking water standards. EC with post-treatment filtration appears to effectively remove trace metal contaminants to potable water standards, but both reactor and source water parameters critically impact removal efficiency.

  19. Removal of trace metal contaminants from potable water by electrocoagulation

    PubMed Central

    Heffron, Joe; Marhefke, Matt; Mayer, Brooke K.

    2016-01-01

    This study investigated the effects of four operational and environmental variables on the removal of trace metal contaminants from drinking water by electrocoagulation (EC). Removal efficiencies for five metals (arsenic, cadmium, chromium, lead and nickel) were compared under varying combinations of electrode material, post-treatment, water composition and pH. Iron electrodes out-performed aluminum electrodes in removing chromium and arsenic. At pH 6.5, aluminum electrodes were slightly more effective at removing nickel and cadmium, while at pH 8.5, iron electrodes were more effective for these metals. Regardless of electrode, cadmium and nickel removal efficiencies were higher at pH 8.5 than at pH 6.5. Post-EC treatment using membrane filtration (0.45 μm) enhanced contaminant removal for all metals but nickel. With the exception of lead, all metals exhibited poorer removal efficiencies as the ionic strength of the background electrolyte increased, particularly in the very high-solids synthetic groundwaters. Residual aluminum concentrations were lowest at pH 6.5, while iron residuals were lowest in low ionic strength waters. Both aluminum and iron residuals required post-treatment filtration to meet drinking water standards. EC with post-treatment filtration appears to effectively remove trace metal contaminants to potable water standards, but both reactor and source water parameters critically impact removal efficiency. PMID:27324564

  20. Process for removing cadmium from scrap metal

    DOEpatents

    Kronberg, James W.

    1995-01-01

    A process for the recovery of a metal, in particular, cadmium contained in scrap, in a stable form. The process comprises the steps of mixing the cadmium-containing scrap with an ammonium carbonate solution, preferably at least a stoichiometric amount of ammonium carbonate, and/or free ammonia, and an oxidizing agent to form a first mixture so that the cadmium will react with the ammonium carbonate to form a water-soluble ammine complex; evaporating the first mixture so that ammine complex dissociates from the first mixture leaving carbonate ions to react with the cadmium and form a second mixture that includes cadmium carbonate; optionally adding water to the second mixture to form a third mixture; adjusting the pH of the third mixture to the acid range whereby the cadmium carbonate will dissolve; and adding at least a stoichiometric amount of sulfide, preferably in the form of hydrogen sulfide or an aqueous ammonium sulfide solution, to the third mixture to precipitate cadmium sulfide. This mixture of sulfide is then preferably digested by heating to facilitate precipitation of large particles of cadmium sulfide. The scrap may be divided by shredding or breaking up to expose additional surface area. Finally, the precipitated cadmium sulfide can be mixed with glass formers and vitrified for permanent disposal.

  1. Process for removing cadmium from scrap metal

    DOEpatents

    Kronberg, J.W.

    1994-01-01

    A process for the recovery of a metal, in particular, cadmium contained in scrap, in a stable form. The process comprises the steps of mixing the cadmium-containing scrap with an ammonium carbonate solution, preferably at least a stoichiometric amount of ammonium carbonate, and/or free ammonia, and an oxidizing agent to form a first mixture so that the cadmium will react with the ammonium carbonate to form a water-soluble ammine complex; evaporating the first mixture so that ammine complex dissociates from the first mixture leaving carbonate ions to react with the cadmium and form a second mixture that includes cadmium carbonate; optionally adding water to the second mixture to form a third mixture; adjusting the pH of the third mixture to the acid range whereby the cadmium carbonate will dissolve; and adding at least a stoichiometric amount of sulfide, preferably in the form of hydrogen sulfide or an aqueous ammonium sulfide solution, to the third mixture to precipitate cadmium sulfide. This mixture of sulfide is then preferably digested by heating to facilitate precipitation of large particles of cadmium sulfide. The scrap may be divided by shredding or breaking up to exposure additional surface area. Finally, the precipitated cadmium sulfide can be mixed with glass formers and vitrified for permanent disposal.

  2. Process for removing cadmium from scrap metal

    DOEpatents

    Kronberg, J.W.

    1995-04-11

    A process is described for the recovery of a metal, in particular, cadmium contained in scrap, in a stable form. The process comprises the steps of mixing the cadmium-containing scrap with an ammonium carbonate solution, preferably at least a stoichiometric amount of ammonium carbonate, and/or free ammonia, and an oxidizing agent to form a first mixture so that the cadmium will react with the ammonium carbonate to form a water-soluble ammine complex; evaporating the first mixture so that ammine complex dissociates from the first mixture leaving carbonate ions to react with the cadmium and form a second mixture that includes cadmium carbonate; optionally adding water to the second mixture to form a third mixture; adjusting the pH of the third mixture to the acid range whereby the cadmium carbonate will dissolve; and adding at least a stoichiometric amount of sulfide, preferably in the form of hydrogen sulfide or an aqueous ammonium sulfide solution, to the third mixture to precipitate cadmium sulfide. This mixture of sulfide is then preferably digested by heating to facilitate precipitation of large particles of cadmium sulfide. The scrap may be divided by shredding or breaking up to expose additional surface area. Finally, the precipitated cadmium sulfide can be mixed with glass formers and vitrified for permanent disposal. 2 figures.

  3. Multiple heavy metal removal using an entomopathogenic fungi Beauveria bassiana.

    PubMed

    Gola, Deepak; Dey, Priyadarshini; Bhattacharya, Arghya; Mishra, Abhishek; Malik, Anushree; Namburath, Maneesh; Ahammad, Shaikh Ziauddin

    2016-10-01

    Towards the development of a potential remediation technology for multiple heavy metals [Zn(II), Cu(II), Cd(II), Cr(VI) and Ni(II)] from contaminated water, present study examined the growth kinetics and heavy metal removal ability of Beauveria bassiana in individual and multi metals. The specific growth rate of B. bassiana varied from 0.025h(-1) to 0.039h(-1) in presence of individual/multi heavy metals. FTIR analysis indicated the involvement of different surface functional groups in biosorption of different metals, while cellular changes in fungus was reflected by various microscopic (SEM, AFM and TEM) analysis. TEM studies proved removal of heavy metals via sorption and accumulation processes, whereas AFM studies revealed increase in cell surface roughness in fungal cells exposed to heavy metals. Present study delivers first report on the mechanism of bioremediation of heavy metals when present individually as well as multi metal mixture by entomopathogenic fungi. PMID:27387415

  4. Tribological properties of silicon carbide in metal removal process

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Buckley, D. H.

    1980-01-01

    Material properties are considered as they relate to adhesion, friction, and wear of single crystal silicon carbide in contact with metals and alloys that are likely to be involved in a metal removal process such as grinding. Metal removal from adhesion between sliding surfaces in contact and metal removal as a result of the silicon carbide sliding against a metal, indenting into it, and plowing a series of grooves or furrows are discussed. Fracture and deformation characteristics of the silicon carbide surface are also covered. The adhesion, friction, and metal transfer to silicon carbide is related to the relative chemical activity of the metals. The more active the metal, the higher the adhesion and friction, and the greater the metal transfer to silicon carbide. Atomic size and content of alloying elements play a dominant role in controlling adhesion, friction, and abrasive wear properties of alloys. The friction and abrasive wear (metal removal) decrease linearly as the shear strength of the bulk metal increases. They decrease as the solute to solvent atomic radius ratio increases or decreases linearly from unity, and with an increase of solute content. The surface fracture of silicon carbide is due to cleavages of 0001, 10(-1)0, and/or 11(-2)0 planes.

  5. Predicting As removal during metal hydroxide precipitation

    SciTech Connect

    McNeill, L.S.; Edwards, M.

    1997-01-01

    A simplified isotherm is described that can predict the extent of arsenate removal at drinking water utilities practicing coagulation or iron-manganese (Fe-Mn) removal. If all possible sources of particulate iron and aluminum hydroxide present in the system are accounted for, the model predicts arsenic (As) removal to within {+-}13 percent (90 percent confidence) for Fe coagulation at pH 6.5--8 and alum coagulation at pH < 7.6. Analysis of full-scale treatment data suggests that colloidal aluminum (Al) flocs with sorbed arsenate [As(V)] may pass through filters, thereby decreasing overall As removal efficiency. Thus, Al solubility and particle stability must be minimized to improve As removal. If stability and solubility of aluminum hydroxide flocs are not a problem, alum and Fe coagulants have nearly equal capacity for sorbing As(V). Survey results also demonstrate the importance of particulate As.

  6. Metal removal from contaminated soil and sediments by the biosurfactant surfactin

    SciTech Connect

    Mulligan, C.N.; Yong, R.N.; Gibbs, B.F.; James, S.; Bennett, H.P.J.

    1999-11-01

    Batch soil washing experiments were performed to evaluate the feasibility of using surfactin from Bacillus subtilis, a lipopeptide biosurfactant, for the removal of heavy metals from a contaminated soil and sediments. The soil contained high levels of metals and hydrocarbons (890 mg/kg of zinc, 420 mg/kg of copper, and 12.6% oil and grease), and the sediments contained 110 mg/kg of copper and 3,300 mg/kg of zinc. The contaminated soil was spiked to increase the level of copper, zinc, and cadmium to 550, 1,200, and 2,000 mg/kg, respectively. Water alone removed minimal amounts of copper and zinc (less than 1%). Results showed that 0.25% surfactin/1% NaOH could remove 25% of the copper and 6% of the zinc from the soil and 15% of the copper and 6% of the zinc from the sediments. A series of five washings of the soil with 0.25% surfactin (1% NaOH) was able to remove 70% of the copper and 22% of the zinc. The technique of ultrafiltration and the measurement of octanol-water partitioning and {zeta}-potential were used to determine the mechanism of metal removal by surfactin. It was indicated that surfactin was able to remove the metals by sorption at the soil interphase and metal complexation, followed by desorption of the metal through interfacial tension lowering and fluid forces and finally complexation of the metal with the micelles.

  7. Mechanisms of bacterial metals removal from solids

    SciTech Connect

    Torma, A.E.; Pryfogle, P.A.

    1990-01-01

    The Great Lakes area sediments are contaminated with varying amounts of heavy metals and polychlorinated organic matter. With respect to the bioremediation of metallic contents of these sediments, it was shown that a number of microorganisms exist which can effectively solubilize heavy metals. The basic reaction mechanisms of bioleaching processes were discussed and the effects of semiconductor character of the sulfide substrate explained. A special emphasis was made to comment on INEL's bioremediation capability. 37 refs.

  8. Development of a regenerable metal oxide CO removal system

    NASA Technical Reports Server (NTRS)

    Cusick, Robert J.

    1990-01-01

    A regenerable metal oxide carbon dioxide (CO2) removal system was developed to replace the current means of a nonreusable chemical, lithium hydroxide, for removing the metabolic CO2 of an astronaut in a space suit. Testing indicates that a viable low-volume metal oxide concept can be used in the portable life support system for CO2 removal during Space Station extravehicular activity (EVA). A canister of nearly the same volume as that used for the Space Shuttle, containing 0.10 cu ft of silver-oxide-based pellets, was tested; test data analysis indicates that 0.18 cu ft of the metal oxide will result in an 8-hour EVA capability. The testing suggests that the metal oxide technology offers a low-volume approach for a reusable CO2 removal concept applicable for at least 40 EVA missions. The development and testing of the breadboard regeneration package is also described.

  9. WORKER REMOVING SLAG FROM THE MOLTEN METAL BATH IN THE ...

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

    WORKER REMOVING SLAG FROM THE MOLTEN METAL BATH IN THE ELECTRIC FURNACE AFTER ADDING A CHEMICAL COAGULANT TO FORCE IT TO THE SURFACE. - Southern Ductile Casting Company, Melting, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

  10. Removal of field and embedded metal by spin spray etching

    DOEpatents

    Contolini, R.J.; Mayer, S.T.; Tarte, L.A.

    1996-01-23

    A process of removing both the field metal, such as copper, and a metal, such as copper, embedded into a dielectric or substrate at substantially the same rate by dripping or spraying a suitable metal etchant onto a spinning wafer to etch the metal evenly on the entire surface of the wafer. By this process the field metal is etched away completely while etching of the metal inside patterned features in the dielectric at the same or a lesser rate. This process is dependent on the type of chemical etchant used, the concentration and the temperature of the solution, and also the rate of spin speed of the wafer during the etching. The process substantially reduces the metal removal time compared to mechanical polishing, for example, and can be carried out using significantly less expensive equipment. 6 figs.

  11. Removal of field and embedded metal by spin spray etching

    DOEpatents

    Contolini, Robert J.; Mayer, Steven T.; Tarte, Lisa A.

    1996-01-01

    A process of removing both the field metal, such as copper, and a metal, such as copper, embedded into a dielectric or substrate at substantially the same rate by dripping or spraying a suitable metal etchant onto a spinning wafer to etch the metal evenly on the entire surface of the wafer. By this process the field metal is etched away completely while etching of the metal inside patterned features in the dielectric at the same or a lesser rate. This process is dependent on the type of chemical etchant used, the concentration and the temperature of the solution, and also the rate of spin speed of the wafer during the etching. The process substantially reduces the metal removal time compared to mechanical polishing, for example, and can be carried out using significantly less expensive equipment.

  12. Individual and competitive removal of heavy metals using capacitive deionization.

    PubMed

    Huang, Zhe; Lu, Lu; Cai, Zhenxiao; Ren, Zhiyong Jason

    2016-01-25

    This study presents the viability and preference of capacitive deionization (CDI) for removing different heavy metal ions in various conditions. The removal performance and mechanisms of three ions, cadmium (Cd(2+)), lead (Pb(2+)) and chromium (Cr(3+)) were investigated individually and as a mixture under different applied voltages and ion concentrations. It was found that CDI could effectively remove these metals, and the performance was positively correlated with the applied voltage. When 1.2 V was applied into solution containing 0.5mM individual ions, the Cd(2+), Pb(2+), and Cr(3+) removal was 32%, 43%, and 52%, respectively, and the electrosorption played a bigger role in Cd(2+) removal than for the other two ions. Interestingly, while the removal of Pb(2+) and Cr(3+) remained at a similar level of 46% in the mixture of three ions, the Cd(2+) removal significantly decreased to 14%. Similar patterns were observed when 0.05 mM was used to simulate natural contaminated water condition, but the removal efficiencies were much higher, with the removal of Pb(2+), Cr(3+), and Cd(2+) increased to 81%, 78%, and 42%, respectively. The low valence charge and lack of physical sorption of Cd(2+) were believed to be the reason for the removal behavior, and advanced microscopic analysis showed clear deposits of metal ions on the cathode surface after operation. PMID:26476320

  13. Process for removing heavy metal compounds from heavy crude oil

    DOEpatents

    Cha, Chang Y.; Boysen, John E.; Branthaver, Jan F.

    1991-01-01

    A process is provided for removing heavy metal compounds from heavy crude oil by mixing the heavy crude oil with tar sand; preheating the mixture to a temperature of about 650.degree. F.; heating said mixture to up to 800.degree. F.; and separating tar sand from the light oils formed during said heating. The heavy metals removed from the heavy oils can be recovered from the spent sand for other uses.

  14. Metals removal and recovery in bioelectrochemical systems: A review.

    PubMed

    Nancharaiah, Y V; Venkata Mohan, S; Lens, P N L

    2015-11-01

    Metal laden wastes and contamination pose a threat to ecosystem well being and human health. Metal containing waste streams are also a valuable resource for recovery of precious and scarce elements. Although biological methods are inexpensive and effective for treating metal wastewaters and in situ bioremediation of metal(loid) contamination, little progress has been made towards metal(loid) recovery. Bioelectrochemical systems are emerging as a new technology platform for removal and recovery of metal ions from metallurgical wastes, process streams and wastewaters. Biodegradation of organic matter by electroactive biofilms at the anode has been successfully coupled to cathodic reduction of metal ions. Until now, leaching of Co(II) from LiCoO2 particles, and removal of metal ions i.e. Co(III/II), Cr(VI), Cu(II), Hg(II), Ag(I), Se(IV), and Cd(II) from aqueous solutions has been demonstrated. This article reviews the state of art research of bioelectrochemical systems for removal and recovery of metal(loid) ions and pertaining removal mechanisms. PMID:26116446

  15. Plasma polymer-functionalized silica particles for heavy metals removal.

    PubMed

    Akhavan, Behnam; Jarvis, Karyn; Majewski, Peter

    2015-02-25

    Highly negatively charged particles were fabricated via an innovative plasma-assisted approach for the removal of heavy metal ions. Thiophene plasma polymerization was used to deposit sulfur-rich films onto silica particles followed by the introduction of oxidized sulfur functionalities, such as sulfonate and sulfonic acid, via water-plasma treatments. Surface chemistry analyses were conducted by X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectroscopy. Electrokinetic measurements quantified the zeta potentials and isoelectric points (IEPs) of modified particles and indicated significant decreases of zeta potentials and IEPs upon plasma modification of particles. Plasma polymerized thiophene-coated particles treated with water plasma for 10 min exhibited an IEP of less than 3.5. The effectiveness of developed surfaces in the adsorption of heavy metal ions was demonstrated through copper (Cu) and zinc (Zn) removal experiments. The removal of metal ions was examined through changing initial pH of solution, removal time, and mass of particles. Increasing the water plasma treatment time to 20 min significantly increased the metal removal efficiency (MRE) of modified particles, whereas further increasing the plasma treatment time reduced the MRE due to the influence of an ablation mechanism. The developed particulate surfaces were capable of removing more than 96.7% of both Cu and Zn ions in 1 h. The combination of plasma polymerization and oxidative plasma treatment is an effective method for the fabrication of new adsorbents for the removal of heavy metals. PMID:25603034

  16. Enhancing toxic metal removal from acidified sludge with nitrite addition.

    PubMed

    Du, Fangzhou; Freguia, Stefano; Yuan, Zhiguo; Keller, Jürg; Pikaar, Ilje

    2015-05-19

    The production of sludge (biosolids) during wastewater treatment is a major issue for water utilities. A main issue limiting its beneficial reuse on agricultural lands is the presence of toxic metals. The currently used metal reduction technologies achieve insufficient removal of metals that are bound to the organic fraction of the sludge. In this study, we propose and demonstrate a novel method that involves the addition of nitrite during sludge acidification to enhance metal removal. Using waste activated sludge collected from three full-scale wastewater treatment plants, we found that acidification to pH 2.0 achieved good Zn solubilization of around 70%, but only 3-7% of Cu was being dissolved. Nitrite addition to the acidified sludge at a concentration of 20 mg NO2(-)-N/L (equals to 19.2 mg HNO2-N/L), substantially enhanced Cu removal to 45-64%, while Zn removal was also increased to over 81%. Metal distribution analysis using sequential chemical extraction revealed that the improvement of Cu and Zn removal was mainly due to the release of the organically bound metal fraction. We hypothesize that free nitrous acid (HNO2, FNA) may assist in the (partial) disruption of extracellular polymeric substances (EPS) and the subsequent release and solubilization of fixed metals. PMID:25872418

  17. Removal of Technetium, Carbon Tetrachloride, and Metals from DOE Properties

    SciTech Connect

    Mallouk, Thomas E.; Darab, John G.

    1999-06-01

    The objective of this research is to prepare, characterize, and evaluate new materials for the removal of technetium (Tc) compounds, halogenated organics, and other troublesome metals from DOE waste streams and contaminated areas. This work follows the discovery that a nanoscale form of zero-valent iron, dispersed on high surface area supports, reduces metal ions (Cr, Hg, Pb, Cd) and Re (as a surrogate for Tc) to insoluble forms much faster than does unsupported iron. The scientific goals of the project are to better understand the mechanism of the reduction process, to develop supports that are compatible with a variety of mixed waste compositions, and to develop surface modifiers for supported iron that will optimize selectivity for the contaminants of interest. The support composition is of particular interest in the case of Tc separation and stabilization in the Hanford tank wastes. While tests with tank waste simulants have shown that pertechnetate is reduced insoluble TcO2, the support material must be compatible with the vitrification process used in the final waste disposition. The surface modifications are also a focal point for Hanford applications because of the complex and variable makeup of the tank wastes.

  18. Pentek metal coating removal system: Baseline report

    SciTech Connect

    1997-07-31

    The Pentek coating removal technology was tested and is being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The Pentek coating removal system consisted of the ROTO-PEEN Scaler, CORNER-CUTTER{reg_sign}, and VAC-PAC{reg_sign}. They are designed to remove coatings from steel, concrete, brick, and wood. The Scaler uses 3M Roto Peen tungsten carbide cutters while the CORNER-CUTTER{reg_sign} uses solid needles for descaling activities. These hand tools are used with the VAC-PAC{reg_sign} vacuum system to capture dust and debris as removal of the coating takes place. The safety and health evaluation during the testing demonstration focused on two main areas of exposure: dust and noise. Dust exposure minimal, but noise exposure was significant. Further testing for each exposure is recommended because of the environment where the testing demonstration took place. It is feasible that the dust and noise levels will be higher in an enclosed operating environment of different construction. In addition, other areas of concern found were arm-hand vibration, whole-body, ergonomics, heat stress, tripping hazards, electrical hazards, machine guarding, and lockout/tagout.

  19. Solid materials for removing metals and fabrication method

    DOEpatents

    Coronado, Paul R.; Reynolds, John G.; Coleman, Sabre J.

    2004-10-19

    Solid materials have been developed to remove contaminating metals and organic compounds from aqueous media. The contaminants are removed by passing the aqueous phase through the solid materials which can be in molded, granular, or powder form. The solid materials adsorb the metals and the organics leaving a purified aqueous stream. The materials are sol-gel and or sol-gel and granulated activated carbon (GAC) mixtures. The species-specific adsorption occurs through specific chemical modifications of the solids tailored towards the contaminant(s). The contaminated solid materials can then be disposed of or the contaminant can be removed and the solids recycled.

  20. REMOVAL OF HEAVY METALS BY ARTIFICIAL WETLANDS

    EPA Science Inventory

    Artificial wetlands have been operated successfully for treatment of municipal wastewater for a number of years at several locations in this country. However, the capability of these systems to treat heavy metal laden municipal wastewater had not previously been investigated. The...

  1. Removal of dissolved metals by plant tissue

    SciTech Connect

    Scott, C.D. )

    1992-04-25

    Various types of microbial biomass have been shown to adsorb metals dissolved in aqueous media. It has now been demonstrated that certain plant tissues are also effective for this type of adsorption process. In particular, tomato and tobacco roots harvested from field-grown plants were shown to adsorb Sr from an aqueous solution of SrCl[sub 2]. Distribution coefficients in excess of 550 were measured and the adsorption isotherms at 25 C could be fitted to Langmuir-type expressions. The bioadsorbent could be regenerated and metals recovered by either a reduction in the pH to less than 2.0 or by use of a concentrated chloride salt solution.

  2. Magnetic process for removing heavy metals from water employing magnetites

    DOEpatents

    Prenger, F. Coyne; Hill, Dallas D.; Padilla, Dennis D.; Wingo, Robert M.; Worl, Laura A.; Johnson, Michael D.

    2003-07-22

    A process for removing heavy metals from water is provided. The process includes the steps of introducing magnetite to a quantity of water containing heavy metal. The magnetite is mixed with the water such that at least a portion of, and preferably the majority of, the heavy metal in the water is bound to the magnetite. Once this occurs the magnetite and absorbed metal is removed from the water by application of a magnetic field. In most applications the process is achieved by flowing the water through a solid magnetized matrix, such as steel wool, such that the magnetite magnetically binds to the solid matrix. The magnetized matrix preferably has remnant magnetism, but may also be subject to an externally applied magnetic field. Once the magnetite and associated heavy metal is bound to the matrix, it can be removed and disposed of, such as by reverse water or air and water flow through the matrix. The magnetite may be formed in-situ by the addition of the necessary quantities of Fe(II) and Fe(III) ions, or pre-formed magnetite may be added, or a combination of seed and in-situ formation may be used. The invention also relates to an apparatus for performing the removal of heavy metals from water using the process outlined above.

  3. Magnetic process for removing heavy metals from water employing magnetites

    DOEpatents

    Prenger, F. Coyne; Hill, Dallas D.

    2006-12-26

    A process for removing heavy metals from water is provided. The process includes the steps of introducing magnetite to a quantity of water containing heavy metal. The magnetite is mixed with the water such that at least a portion of, and preferably the majority of, the heavy metal in the water is bound to the magnetite. Once this occurs the magnetite and absorbed metal is removed from the water by application of a magnetic field. In most applications the process is achieved by flowing the water through a solid magnetized matrix, such as steel wool, such that the magnetite magnetically binds to the solid matrix. The magnetized matrix preferably has remnant magnetism, but may also be subject to an externally applied magnetic field. Once the magnetite and associated heavy metal is bound to the matrix, it can be removed and disposed of, such as by reverse water or air and water flow through the matrix. The magnetite may be formed in-situ by the addition of the necessary quantities of Fe(II) and Fe(III) ions, or pre-formed magnetite may be added, or a combination of seed and in-situ formation may be used. The invention also relates to an apparatus for performing the removal of heavy metals from water using the process outlined above.

  4. Electrochemical removal of material from metallic work

    DOEpatents

    Csakvary, Tibor; Fromson, Robert E.

    1980-05-13

    Deburring, polishing, surface forming and the like are carried out by electrochemical machining with conformable electrode means including an electrically conducting and an insulating web. The surface of the work to be processed is covered by a deformable electrically insulating web or cloth which is perforated and conforms with the work. The web is covered by a deformable perforated electrically conducting screen electrode which also conforms with, and is insulated from, the work by the insulating web. An electrolyte is conducted through the electrode and insulating web and along the work through a perforated elastic member which engages the electrode under pressure pressing the electrode and web against the work. High current under low voltage is conducted betwen the electrode and work through the insulator, removing material from the work. Under the pressure of the elastic member, the electrode and insulator continue to conform with the work and the spacing between the electrode and work is maintained constant.

  5. Removal of heavy metals by hybrid electrocoagulation and microfiltration processes.

    PubMed

    Keerthi; Vinduja, V; Balasubramanian, N

    2013-01-01

    This study is based on the investigation of the performance of electrocoagulation (EC), followed by the microfiltration process for heavy metal removal in synthetic model waste water containing Zn2+, Ni2+ and Cd2+ ions. Effects of initial concentration, current density and pH on metal removal were analysed to optimize the EC process. The optimized EC process was then integrated with dead-end microfiltration (MF) and was found that the hybrid process was capable of 99% removal of heavy metals. The cake layer formed over the membrane by the hybrid process was analysed through scanning electron microscope-energy-dispersive X-ray spectroscopy. The particle size analysis of the sludge formed during EC was done to investigate the fouling caused during the process. PMID:24527655

  6. Chitosan removes toxic heavy metal ions from cigarette mainstream smoke

    NASA Astrophysics Data System (ADS)

    Zhou, Wen; Xu, Ying; Wang, Dongfeng; Zhou, Shilu

    2013-09-01

    This study investigated the removal of heavy metal ions from cigarette mainstream smoke using chitosan. Chitosan of various deacetylation degrees and molecular weights were manually added to cigarette filters in different dosages. The mainstream smoke particulate matter was collected by a Cambridge filter pad, digested by a microwave digestor, and then analyzed for contents of heavy metal ions, including As(III/V), Pb(II), Cd(II), Cr(III/VI) and Ni(II), by graphite furnace atomic absorption spectrometry (GFAAS). The results showed that chitosan had a removal effect on Pb(II), Cd(II), Cr(III/VI) and Ni(II). Of these, the percent removal of Ni(II) was elevated with an increasing dosage of chitosan. Chitosan of a high deace tylation degree exhibited good binding performance toward Cd(II), Cr(III/VI) and Ni(II), though with poor efficiency for Pb(II). Except As(III/V), all the tested metal ions showed similar tendencies in the growing contents with an increasing chitosan molecular weight. Nonetheless, the percent removal of Cr(III/VI) peaked with a chitosan molecular weight of 200 kDa, followed by a dramatic decrease with an increasing chitosan molecular weight. Generally, chitosan had different removal effects on four out of five tested metal ions, and the percent removal of Cd(II), Pb(II), Cr(III/VI) and Ni(II) was approximately 55%, 45%, 50%, and 16%, respectively. In a word, chitosan used in cigarette filter can remove toxic heavy metal ions in the mainstream smoke, improve cigarette safety, and reduce the harm to smokers.

  7. Removal of heavy metal from industrial effluents using Baker's yeast

    NASA Astrophysics Data System (ADS)

    Ferdous, Anika; Maisha, Nuzhat; Sultana, Nayer; Ahmed, Shoeb

    2016-07-01

    Bioremediation of wastewater containing heavy metals is one of the major challenges in environmental biotechnology. Heavy metals are not degraded and as a result they remain in the ecosystem, and pose serious health hazards as it comes in contact with human due to anthropogenic activities. Biological treatment with various microorganisms has been practiced widely in recent past, however, accessing and maintaining the microorganisms have always been a challenge. Microorganisms like Baker's yeast can be very promising biosorbents as they offer high surface to volume ratio, large availability, rapid kinetics of adsorption and desorption and low cost. The main aim of this study is to evaluate the applicability of the biosorption process using baker's yeast. Here we present an experimental investigation of biosorption of Chromium (Cr) from water using commercial Baker's Yeast. It was envisaged that yeast, dead or alive, would adsorb heavy metals, however, operating parameters could play vital roles in determining the removal efficiency. Parameters, such as incubation time, pH, amount of biosorbent and heavy metal concentration were varied to investigate the impacts of those parameters on removal efficiency. Rate of removal was found to be inversely proportional to the initial Cr (+6) concentrations but the removal rate per unit biomass was a weakly dependent on initial Cr(+6) concentrations. Biosorption process was found to be more efficient at lower pH and it exhibited lower removal with the increase in solution pH. The optimum incubation time was found to be between 6-8 hours and optimum pH for the metal ion solution was 2. The effluents produced in leather industries are the major source of chromium pollution in Bangladesh and this study has presented a very cost effective yet efficient heavy metal removal approach that can be adopted for such kind of wastewater.

  8. Removal of Technetium, Carbon Tetrachloride, and Metals from DOE Properties.

    SciTech Connect

    Mallouk, Thomas E.; Ponder, Sherman M.; Darab, John

    2000-06-01

    The objective of this research is to prepare, characterize, and evaluate new materials for the removal of technetium (Tc) compounds, halogenated organics, and other troublesome metals from DOE waste streams and contaminated areas. This work follows the discovery that a nanoscale form of zero-valent iron, dispersed on high surface area supports, reduces metal ions (Cr, Hg, Pb, Cd) and Re (as a surrogate for Tc) to insoluble forms faster and with higher efficiency than does unsupported iron. Liquid-liquid extraction methods are also being developed for quantitative removal of Cs from tetraphenylborate salt mixtures, which are generated in waste processing at Savannah River, and conversion to vitrifiable inorganic Cs salts.

  9. Two-stage anaerobic digestion enables heavy metal removal.

    PubMed

    Selling, Robert; Håkansson, Torbjörn; Björnsson, Lovisa

    2008-01-01

    To fully exploit the environmental benefits of the biogas process, the digestate should be recycled as biofertiliser to agriculture. This practice can however be jeopardized by the presence of unwanted compounds such as heavy metals in the digestate. By using two-stage digestion, where the first stage includes hydrolysis/acidification and liquefaction of the substrate, heavy metals can be transferred to the leachate. From the leachate, metals can then be removed by adsorption. In this study, up to 70% of the Ni, 40% of the Zn and 25% of the Cd present in maize was removed when the leachate from hydrolysis was circulated over a macroporous polyacrylamide column for 6 days. For Cu and Pb, the mobilization in the hydrolytic stage was lower which resulted in a low removal. A more efficient two-stage process with improved substrate hydrolysis would give lower pH and/or longer periods with low pH in the hydrolytic stage. This is likely to increase metal mobilisation, and would open up for an excellent opportunity of heavy metal removal. PMID:18359995

  10. New trends in removing heavy metals from wastewater.

    PubMed

    Zhao, Meihua; Xu, Ying; Zhang, Chaosheng; Rong, Hongwei; Zeng, Guangming

    2016-08-01

    With the development of researches, the treatments of wastewater have reached a certain level. Whereas, heavy metals in wastewater cause special concern in recent times due to their recalcitrance and persistence in the environment. Therefore, it is important to get rid of the heavy metals in wastewater. The previous studies have provided many alternative processes in removing heavy metals from wastewater. This paper reviews the recent developments and various methods for the removal of heavy metals from wastewater. It also evaluates the advantages and limitations in application of these techniques. A particular focus is given to innovative removal processes including adsorption on abiological adsorbents, biosorption, and photocatalysis. Because these processes have leaded the new trends and attracted more and more researches in removing heavy metals from wastewater due to their high efficency, pluripotency and availability in a copious amount. In general, the applicability, characteristic of wastewater, cost-effectiveness, and plant simplicity are the key factors in selecting the most suitable method for the contaminated wastewater. PMID:27318819

  11. Targeted Removal of Bioavailable Metal as a Detoxification Strategy for Carbon Nanotubes

    PubMed Central

    Liu, Xinyuan; Guo, Lin; Morris, Daniel; Kane, Agnes B.; Hurt, Robert H.

    2008-01-01

    There is substantial evidence for toxicity and/or carcinogenicity upon inhalation of pure transition metals in fine particulate form. Carbon nanotube catalyst residues may trigger similar metal-mediated toxicity, but only if the metal is bioavailable and not fully encapsulated within fluid-protective carbon shells. Recent studies have documented the presence of bioavailable iron and nickel in a variety of commercial as-produced and vendor “purified” nanotubes, and the present article examines techniques to avoid or remove this bioavailable metal. First, data are presented on the mechanisms potentially responsible for free metal in “purified” samples, including kinetic limitations during metal dissolution, the re-deposition or adsorption of metal on nanotube outer surfaces, and carbon shell damage during last-step oxidation or one-pot purification. Optimized acid treatment protocols are presented for targeting the free metal, considering the effects of acid strength, composition, time, and conditions for post-treatment water washing. Finally, after optimized acid treatment, it is shown that the remaining, non-bioavailable (encapsulated) metal persists in a stable and biologically unavailable form up to two months in an in vitro biopersistence assay, suggesting that simple removal of bioavailable (free) metal is a promising strategy for reducing nanotube health risks. PMID:19255622

  12. Metal Removal Efficiency And Ecotoxicological Assessment Of Field-Scale Passive Treatment Biochemical Reactors

    EPA Science Inventory

    Anaerobic biochemical reactors (BCRs) are useful for removing metals from mining-impacted water at remote sites. Removal processes include sorption and precipitation of metal sulfides, carbonates, and hydroxides. A question of interest is whether BCRs remove aquatic toxicity. ...

  13. Metal removal efficiency and ecotoxicological assessment of field-scale passive treatment biochemical reactors

    EPA Science Inventory

    Anaerobic biochemical reactors (BCRs) are useful for removing metals from mining-impacted water (MIW) at remote sites. Removal processes include sorption and precipitation of metal sulfides, carbonates and hydroxides. A question of interest is whether BCRs remove aquatic toxicit...

  14. A biosystem for removal of metal ions from water

    SciTech Connect

    Kilbane, J.J. II.

    1990-01-01

    The presence of heavy metal ions in ground and surface waters constitutes a potential health risk and is an environmental concern. Moreover, processes for the recovery of valuable metal ions are of interest. Bioaccumulation or biosorption is not only a factor in assessing the environmental risk posed by metal ions; it can also be used as a means of decontamination. A biological system for the removal and recovery of metal ions from contaminated water is reported here. Exopolysaccharide-producing microorganisms, including a methanotrophic culture, are demonstrated to have superior metal binding ability, compared with other microbial cultures. This paper describes a biosorption process in which dried biomass obtained from exopolysaccharide-producing microorganisms is encapsulated in porous plastic beads and is used for metal ion binding and recovery. 22 refs., 13 figs.

  15. Removal of Selected Metals from Wastewater Using a Constructed Wetland.

    PubMed

    Šíma, Jan; Svoboda, Lubomír; Pomijová, Zuzana

    2016-05-01

    Removal of selected metals from municipal wastewater using a constructed wetland with a horizontal subsurface flow was studied. The objective of the work was to determine the efficiency of Cu, Zn, Ni, Co, Sr, Li, and Rb removal, and to describe the main removal mechanisms. The highest removal efficiencies were attained for zinc and copper (89.8 and 81.5%, respectively). It is apparently due to the precipitation of insoluble sulfides (ZnS, CuS) in the vegetation bed where the sulfate reduction takes place. Significantly lower removal efficiencies (43.9, 27.7, and 21.5%) were observed for Li, Sr, and Rb, respectively. Rather, low removal efficiencies were also attained for Ni and Co (39.8 and 20.9%). However, the concentrations of these metals in treated water were significantly lower compared to Cu and Zn (e.g., 2.8 ± 0.5 and 1.7 ± 0.3 μg/l for Ni at the inflow and outflow from the wetland compared to 27.6 ± 12.0 and 5.1 ± 4.7 μg/l obtained for Cu, respectively). The main perspective of the constructed wetland is the removal of toxic heavy metals forming insoluble compounds depositing in the wetland bed. Metal uptake occurs preferentially in wetland sediments and is closely associated with the chemism of sulfur and iron. PMID:27119624

  16. ULTRASONIC ENHANCEMENT OF THE REMOVAL OF HEAVY METALS

    EPA Science Inventory

    EPA GRANT NUMBER: R828598C020
    Title: Ultrasonic Enhancement of the Removal of Heavy Metals
    Investigators: Dennis Truax, Krishnan Balasubramaniam
    Institution: Mississippi State University
    EPA Project Officer: S. Bala Krishnan
    ...

  17. METALS REMOVALS AND PARTITIONING IN CONVENTIONAL WASTEWATER TREATMENT PLANTS

    EPA Science Inventory

    Metals removal and partitioning to primary and secondary sludge during treatment of domestic wastewater by conventional sewage treatment processes was studied. Raw wastewater entering the Mill Creek Sewage Treatment Plant, Cincinnati, Ohio, was fed to a 0.1 l/s (1.6 gpm) pilot tr...

  18. Enhanced metal removal from wastewater by coagulant addition

    SciTech Connect

    Karthikeyan, K.G.; Elliott, H.A.; Cannon, F.S.

    1996-11-01

    Besides metallurgical industries, metal-containing wastewaters are generated in the manufacturing/processing of batteries, petroleum, photographic materials, paints, inks, leather, and wood. The toxic nature of the heavy metals has resulted in the promulgation of standards requiring very low concentration of metals in the treated effluent. To comply with the strict regulatory requirements, it is necessary to treat the wastewaters (both industrial and municipal) before discharging them into natural water bodies. The objective of this study was to compare the pH-dependent Cu and Cd removal profiles for simple precipitation, adsorption, and coprecipitation in the presence of freshly-formed hydrous oxides of Fe and Al. Because of the significantly different pH at which hydrolysis/precipitation occurs, Cu and Cd were chosen as representative heavy metals. The results have been interpreted in the context of investing the use of coagulants to achieve low metal concentrations in wastewater effluents.

  19. Metal chelate process to remove pollutants from fluids

    DOEpatents

    Chang, S.G.T.

    1994-12-06

    The present invention relates to improved methods using an organic iron chelate to remove pollutants from fluids, such as flue gas. Specifically, the present invention relates to a process to remove NO[sub x] and optionally SO[sub 2] from a fluid using a metal ion (Fe[sup 2+]) chelate wherein the ligand is a dimercapto compound wherein the --SH groups are attached to adjacent carbon atoms (HS--C--C--SH) or (SH--C--CCSH) and contain a polar functional group so that the ligand of DMC chelate is water soluble. Alternatively, the DMC is covalently attached to a water insoluble substrate such as a polymer or resin, e.g., polystyrene. The chelate is regenerated using electroreduction or a chemical additive. The dimercapto compound bonded to a water insoluble substrate is also useful to lower the concentration or remove hazardous metal ions from an aqueous solution. 26 figures.

  20. Metal chelate process to remove pollutants from fluids

    DOEpatents

    Chang, Shih-Ger T.

    1994-01-01

    The present invention relates to improved methods using an organic iron chelate to remove pollutants from fluids, such as flue gas. Specifically, the present invention relates to a process to remove NO.sub.x and optionally SO.sub.2 from a fluid using a metal ion (Fe.sup.2+) chelate wherein the ligand is a dimercapto compound wherein the --SH groups are attached to adjacent carbon atoms (HS--C--C--SH) or (SH--C--CCSH) and contain a polar functional group so that the ligand of DMC chelate is water soluble. Alternatively, the DMC' is covalently attached to a water insoluble substrate such as a polymer or resin, e.g., polystyrene. The chelate is regenerated using electroreduction or a chemical additive. The dimercapto compound bonded to a water insoluble substrate is also useful to lower the concentration or remove hazardous metal ions from an aqueous solution.

  1. Removal of metals by sorghum plants from contaminated land.

    PubMed

    Zhuang, Ping; Shu, Wensheng; Li, Zhian; Liao, Bin; Li, Jintian; Shao, Jingsong

    2009-01-01

    The growth of high biomass crops facilitated by optimal of agronomic practices has been considered as an alternative to phytoremediation of soils contaminated by heavy metals. A field trial was carried out to evaluate the phytoextraction efficiency of heavy metals by three varieties of sweet sorghum (Sorghum biocolor L.), a high biomass energy plant. Ethylene diamine tetraacetate (EDTA), ammonium nitrate (NH4NO3) and ammonium sulphate ((NH4)2SO4) were tested for their abilities to enhance the removal of heavy metals Pb, Cd, Zn, and Cu by sweet sorghum from a contaminated agricultural soil. Sorghum plants always achieved the greatest removal of Pb by leaves and the greatest removal of Cd, Zn and Cu by stems. There was no significant difference among the Keller, Rio and Mray varieties of sweet sorghums in accumulating heavy metals. EDTA treatment was more efficient than ammonium nitrate and ammonium sulphate in promoting Pb accumulation in sweet sorghum from the contaminated agricultural soil. The application of ammonium nitrate and ammonium sulphate increased the accumulation of both Zn and Cd in roots of sorghum plants. Results from this study suggest that cropping of sorghum plants facilitated by agronomic practices may be a sustainable technique for partial decontamination of heavy metal contaminated soils. PMID:19999999

  2. Heavy metals removal from mine runoff using compost bioreactors.

    PubMed

    Christian, David; Wong, Edmund; Crawford, Ronald L; Cheng, I Francis; Hess, Thomas F

    2010-12-14

    Permeable bioreactors have gained both research and management attention as viable methods for treating mine runoff waters. We examined the operation of a field-scale bioreactor (containing mixed compost, straw and gravel) for treatment of runoff from the Mother Load (ML) mine in northern Idaho, U.S. and compared it to an experimental laboratory-scale reactor, containing a similar matrix and treating similar mine runoff water. In general both reactors were efficient in removing most of the metals assayed, Al, As, Cd, Fe, Ni, Pb and Zn, with the exception of Mn. Both systems showed evidence of bacterial-mediated sulphate reduction and concomitant metal sulphide complexes. However, the experimental laboratory bioreactor showed greater proportions of immobile metals reductions than did the ML bioreactor, presumably due to the greater action of sulphate-reducing bacteria. The major metal removal mechanism in the ML bioreactor was surmised to be adsorption. Differences in metal removal mechanisms between the reactors were hypothesized to be due to fluctuating hydraulic residence times at the ML site, in turn, due to unregulated runoff flow. PMID:21275250

  3. Method for removing metal ions from solution with titanate sorbents

    DOEpatents

    Lundquist, Susan H.; White, Lloyd R.

    1999-01-01

    A method for removing metal ions from solution comprises the steps of providing titanate particles by spray-drying a solution or slurry comprising sorbent titanates having a particle size up to 20 micrometers, optionally in the presence of polymer free of cellulose functionality as binder, said sorbent being active towards heavy metals from Periodic Table (CAS version) Groups IA, IIA, IB, IIB, IIIB, and VIII, to provide monodisperse, substantially spherical particles in a yield of at least 70 percent of theoretical yield and having a particle size distribution in the range of 1 to 500 micrometers. The particles can be used free flowing in columns or beds, or entrapped in a nonwoven, fibrous web or matrix or a cast porous membrane, to selectively remove metal ions from aqueous or organic liquid.

  4. Occurrence and removal of metals in urban wastewater treatment plants.

    PubMed

    Ustün, Gökhan Ekrem

    2009-12-30

    In this study, nine metals (Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) found in urban wastewater treatment plants (WTPs) in Bursa (Turkey) were monitored for 23 months in 2002 and 2007. Metal influent and effluent concentrations of wastewater stabilization ponds (WSPs) and the activated sludge process (ASP) measured via 24-h composite samples were used to determine removal efficiencies. Average influent concentrations ranged between 2 microg/L (Cd) and 1975 microg/L (Fe). In the stabilization ponds, the removal efficiency was 58% for Cr, while for Cd, Mn, and Pb, it was less than 20%. The activated sludge process yielded high removal efficiencies, ranging from 47% for Ni to 95% for Cr. The use of treated wastewaters for agricultural purposes was investigated, and it was determined that all metal concentrations met application limits, with the exception of Cr in wastewater stabilization pond effluent. Results showed that wastewater stabilization pond effluent reduced the receiving water quality with respect to Cr, Cu, Ni, and Pb. In addition, it was shown that effluent from the activated sludge process temporarily improved the receiving water quality with regard to the Cd, Cu, Mn, and Zn parameters. However, considering the periodic variations of the metals in both processes, water quality, and agricultural practices, it was determined that they should be monitored continuously. PMID:19683867

  5. Method for removal of furfural coke from metal surfaces

    SciTech Connect

    Turner, J.D.

    1990-02-27

    This patent describes a process for preparing furfural coke for removal from metallic surfaces. It comprises: heating ship furfural coke without causing an evolution of heat capable of undesirably altering metallurgical properties of the surfaces in the presence of a gas with a total pressure of less than 100 psig containing molecular oxygen. The gas being at a sufficient temperature below 800{degrees}F. (427{degrees}C.) for a sufficient time to change the crush strength of the coke so as to permit removal with a water jet at a pressure of about 5000 psi.

  6. Application of aragonite shells for the removal of aqueous metals in polluted soils and wastewaters.

    NASA Astrophysics Data System (ADS)

    Bucca, M.; Köhler, S. J.; Dietzel, M.

    2009-04-01

    In the present study the use of coupled precipitation/dissolution processes for metal (Me) removal from polluted soils and waters by biogenic carbonate (CaCO3) shell surfaces is proposed, according to the following overall reaction: CaCO3 + Me2+ = MeCO3 + Ca2+ This reaction has been investigated at fixed experimental conditions using synthetic model systems consisting in columns, batch, and reactors (e.g. lead, zinc, and cadmium artificial solutions mixed with aragonite shells) that allowed quantifying the kinetics of the process of metal carbonate formation. The above mentioned process has the potential of being used in three different areas of water treatment: a) use of shells as a cheap and effective geologic barrier for contaminated ground or surface waters, b) use as a material in filter beds or fluidized bed for selective cleaning of waste water with the potential of partial metal recovery and c) use as seed crystals during the elimination of metals through precipitation with soda (Na2CO3). Acidic wastewaters containing several pollutants, including heavy and trace metals, are created during production of pesticides, paper, lubricating oil, batteries, acid/alkali, or in ship repair manufacturing, mines drainage systems, metalworking and metal plating industries. Biogenic shells are a waste product in many coastal countries and may thus be more favorable than other solid phases such as clays or zeolithes from an economic viewpoint. Our metal elimination study aims at setting up a low-cost effective elimination system for various types of metal rich waste waters. A number of experimental techniques such as batch, column and flow through reactors were used to optimize the metal removal efficiency in both synthetic and waste waters from the metal finishing industry. Solid liquid ratio, initial and final pH, metal concentration and combination of metals have been varied. Measurements of pH, metal concentration, conductivity and alkalinity were recorded over the

  7. Bead and Process for Removing Dissolved Metal Contaminants

    SciTech Connect

    Summers, Bobby L., Jr.; Bennett, Karen L.; Foster, Scott A.

    2005-01-18

    A bead is provided which comprises or consists essentially of activated carbon immobilized by crosslinked poly (carboxylic acid) binder, sodium silicate binder, or polyamine binder. The bead is effective to remove metal and other ionic contaminants from dilute aqueous solutions. A method of making metal-ion sorbing beads is provided, comprising combining activated carbon, and binder solution (preferably in a pin mixer where it is whipped), forming wet beads, and heating and drying the beads. The binder solution is preferably poly(acrylic acid) and glycerol dissolved in water and the wet beads formed from such binder solution are preferably heated and crosslinked in a convection oven.

  8. Removal of Trichloroethylene and Heavy Metals by Zerovalent Iron Nanoparticles

    NASA Astrophysics Data System (ADS)

    Boparai, H. K.; O'Carroll, D. M.

    2009-05-01

    Heavy metals combined with chlorinated solvents are one class of mixed waste found at various hazardous waste sites in North America. Nano zerovalent iron (nZVI), an emerging technology, is being successfully used for treating chlorinated solvents and heavy metals independently, however comparatively little research has investigated the remediation of the wastes when they are present in the same mixture. The remediation of trichloroethylene (TCE)/heavy metal waste mixtures via nZVI has been investigated in the present study. Results suggest that some metals are reduced by nZVI to their zerovalent state and thus precipitate on nZVI particles. This improves the contaminant removal performance of nZVI by forming bimetallic iron nanoparticles. Other metals are directly precipitated or adsorbed on the nZVI particles in their original oxidation state and are rendered immobile. In some cases the presence of the heavy metals in the waste mixture enhanced the dechlorination of TCE while in other cases it did not. This study suggests that nano zerovalent iron particles can be effectively used for the remediation of mixed contamination of heavy metals and chlorinated solvents. Results have been supported by a variety of techniques including X-ray photoelectron spectroscopy (XPS) analysis.

  9. Graphene-Based Microbots for Toxic Heavy Metal Removal and Recovery from Water.

    PubMed

    Vilela, Diana; Parmar, Jemish; Zeng, Yongfei; Zhao, Yanli; Sánchez, Samuel

    2016-04-13

    Heavy metal contamination in water is a serious risk to the public health and other life forms on earth. Current research in nanotechnology is developing new nanosystems and nanomaterials for the fast and efficient removal of pollutants and heavy metals from water. Here, we report graphene oxide-based microbots (GOx-microbots) as active self-propelled systems for the capture, transfer, and removal of a heavy metal (i.e., lead) and its subsequent recovery for recycling purposes. Microbots' structure consists of nanosized multilayers of graphene oxide, nickel, and platinum, providing different functionalities. The outer layer of graphene oxide captures lead on the surface, and the inner layer of platinum functions as the engine decomposing hydrogen peroxide fuel for self-propulsion, while the middle layer of nickel enables external magnetic control of the microbots. Mobile GOx-microbots remove lead 10 times more efficiently than nonmotile GOx-microbots, cleaning water from 1000 ppb down to below 50 ppb in 60 min. Furthermore, after chemical detachment of lead from the surface of GOx-microbots, the microbots can be reused. Finally, we demonstrate the magnetic control of the GOx-microbots inside a microfluidic system as a proof-of-concept for automatic microbots-based system to remove and recover heavy metals. PMID:26998896

  10. Graphene-Based Microbots for Toxic Heavy Metal Removal and Recovery from Water

    PubMed Central

    2016-01-01

    Heavy metal contamination in water is a serious risk to the public health and other life forms on earth. Current research in nanotechnology is developing new nanosystems and nanomaterials for the fast and efficient removal of pollutants and heavy metals from water. Here, we report graphene oxide-based microbots (GOx-microbots) as active self-propelled systems for the capture, transfer, and removal of a heavy metal (i.e., lead) and its subsequent recovery for recycling purposes. Microbots’ structure consists of nanosized multilayers of graphene oxide, nickel, and platinum, providing different functionalities. The outer layer of graphene oxide captures lead on the surface, and the inner layer of platinum functions as the engine decomposing hydrogen peroxide fuel for self-propulsion, while the middle layer of nickel enables external magnetic control of the microbots. Mobile GOx-microbots remove lead 10 times more efficiently than nonmotile GOx-microbots, cleaning water from 1000 ppb down to below 50 ppb in 60 min. Furthermore, after chemical detachment of lead from the surface of GOx-microbots, the microbots can be reused. Finally, we demonstrate the magnetic control of the GOx-microbots inside a microfluidic system as a proof-of-concept for automatic microbots-based system to remove and recover heavy metals. PMID:26998896

  11. Removal Of Heavy Metals From Electroplating Wastewater By Anaerobic Bacteria

    NASA Astrophysics Data System (ADS)

    Ma, Wanggang; Sun, Peide; Song, Yingqi; Zhang, Yi; Yin, Jun

    2010-11-01

    Biosorption of heavy metals from simulated wastewater and the raw electroplating wastewater with "BM (Biosorption of Metals) bacteria" were investigated in this study. The influence of initial pH, biosorbents dose, concentration of ions, contact time and temperature on biosorption capacity of Cr(VI) and Ni(II) were studied. The optimum pH for biosorption of Cr(VI) was found to be low, and the removal efficiency of Cr(VI) was 98.60% with "BM bacteria" at pH 2. The removal efficiency of Ni(II) was increased with increasing the pH, and was enhanced up to 115% compared with the wastewater without BM bacteria. In this experiment, the "BM bacteria" efficiently removed Cu(II), Ni(II), Cr(VI), Zn(II) and COD from the raw electroplating wastewater, and the removal efficiencies were 98.92%, 99.92%, 99.86%, 99.93% and 45.20% respectively.

  12. Effective Removal of Heavy Metals from Wastewater Using Modified Clay.

    PubMed

    Song, Mun-Seon; Vijayarangamuthu, K; Han, EunJi; Jeon, Ki-Joon

    2016-05-01

    We report an economical and eco-friendly way to remove the heavy metal pollutant using modified clay. The modification of clay was done by calcining the natural clay from Kyushu region in Japan. Further, the removal efficiency for various pH and contact time was evaluated. The morphology of the clays was studied using the scanning electron microscopy (SEM). The structural and chemical analyses of modified clay were done by using X-ray diffraction (XRD), Raman spectroscopy, and Energy dispersion analysis (EDAX) to understand the properties related to the removal of heavy metal pollutant. Further, we studied the absorption efficiency of clay for various pH and contacting time using Ni polluted water. The modified clays show better removal efficiency for all pH with different saturation time. The adsorption follows pseudo-second order kinetics and the adsorption capacity of modified clay is 1.5 times larger than that of natural clay. The increase in the adsorption efficiency of modified clay was correlated to the increase in hematite phase along with increase in surface area due to surface morphological changes. PMID:27483775

  13. RETENTION TIME EFFECT ON METAL REMOVAL BY PEAT COLUMNS

    SciTech Connect

    Nelson, E

    2007-02-28

    The potential use of a peat bed to treat the H-12 Outfall discharge to bring it to new compliance limits was previously investigated and reported utilizing a 7 hour retention time. The influence of retention time (contact time) of water with peat moss on the removal of copper from the water was investigated under laboratory conditions using vertical flow peat moss columns. Reduction of the necessary retention time has a large influence on the design sizing of any peat bed that would be constructed to treat the H-12 discharge on a full scale basis. Retention times of 5 hours, 3 hours and 1 hour were tested to determine the copper removal by the peat columns using vertical flow. Water samples were collected after 4, 8, 12, and 16 water volumes had passed through the columns and analyzed for a suite of metals, with quantitative emphasis on copper. Laboratory results indicated that copper removal was very high at each of the 3 retention times tested, ranging from 99.6 % removal at 5 and 3 hours to 98.8% removal at 1 hour. All these values are much lower that the new compliance limit for the outfall. The results also indicated that most divalent metals were removed to their normal reporting detection limit for the analytical methods used, including zinc. Lead levels in the H-12 discharge used in this study were below PQL in all samples analyzed. While each of the retention times studied removed copper very well, there were indications that 1 hour is probably too short for an operational, long-term facility. At that retention time, there was about 6% compaction of the peat in the column due to the water velocity, and this may affect long term hydraulic conductivity of the peat bed. At that retention time, copper concentration in the effluent was higher than the other times tested, although still very low. Because of the potential compacting and somewhat reduced removal efficiency at a 1 hour retention time, it would be prudent to design to at least a 3 hour retention

  14. Removal of metal cations from water using zeolites

    SciTech Connect

    Zamzow, M.J.; Murphy, J.E. )

    1992-11-01

    Zeolites from abundant natural deposits were investigated by the Bureau of Mines for efficiently cleaning up mining industry wastewaters. Twenty-four zeolite samples were analyzed by x-ray diffraction and inductively coupled plasma. These included clinoptilolite, mordenite, chabazite, erionite, and phillipsite. Bulk densities of a sized fraction ([minus]40, +65 mesh) varied from 0.48 to 0.93 g/ml. Attrition losses ranged from 1 to 18% during an hour-long shake test. The 24 zeolites and an ion-exchange resin were tested for the uptake of Cd, Cu, and Zn. Of the natural zeolites, phillipsite proved to be the most efficient, while the mordenites had the lowest uptakes. Sodium was the most effective exchangeable ion for exchange of heavy metals. Wastewater from an abandoned copper mine in Nevada was used to test the effectiveness of clinoptilolite for treating a multi-ion wastewater. The metal ions Fe[sup 3+], Cu[sup 2+], and Zn[sup 2+] in the copper mine wastewater were removed to below drinking water standards, but Mn[sup 2+] and Ni[sup 2+] were not. Calcium and NH[sub 4][sup +] interfered with the uptake of heavy metals. Adsorbed heavy metals were eluted from zeolites with a 3% NaCl solution. Heavy metals were concentrated in the eluates up to 30-fold relative to the waste solution. Anions were not adsorbed by the zeolites.

  15. A new material for removing heavy metals from water

    NASA Technical Reports Server (NTRS)

    Philipp, Warren H., Jr.; Street, Kenneth W., Jr.

    1994-01-01

    The NASA Lewis Research Center developed and is patenting a new high capacity ion exchange material (IEM) that removes toxic metals from contaminated water in laboratory tests. The IEM can be made into many forms, such as thin films, coatings, pellets, and fibers. As a result, it can be adapted to many applications to purify contaminated water wherever it is found, be it in waste water treatment systems, lakes, ponds, industrial plants, or in homes. Laboratory tests have been conducted on aqueous solutions containing only one of the following metal cations: lead, copper, mercury, cadmium, silver, chromium (III), nickel, zinc, and yttrium. Tests were also conducted with: (1) calcium present to determine its effects on the uptake of cadmium and copper, and (2) uranium and lanthanides which are stand-ins for other radioactive elements, (3) drinking water for the removal of copper and lead, and (3) others compositions. The results revealed that the IEM removes all these cations, even in the presence of the calcium. Of particular interest are the results of the tests with the drinking water: the lead concentration was reduced from 142 ppb down to 2.8 ppb (well below the accepted EPA standard).

  16. Liquid metal Flow Meter - Final Report

    SciTech Connect

    Andersen, C.; Hoogendoom, S.; Hudson, B.; Prince, J.; Teichert, K.; Wood, J.; Chase, K.

    2007-01-30

    Measuring the flow of liquid metal presents serious challenges. Current commercially-available flow meters use ultrasonic, electromagnetic, and other technologies to measure flow, but are inadequate for liquid metal flow measurement because of the high temperatures required by most liquid metals. As a result of the reactivity and high temperatures of most liquid metals, corrosion and leakage become very serious safety concerns. The purpose of this project is to develop a flow meter for Lockheed Martin that measures the flow rate of molten metal in a conduit.

  17. Metal MEMS Tools for Beating-heart Tissue Removal

    PubMed Central

    Gosline, Andrew H.; Vasilyev, Nikolay V.; Veeramani, Arun; Wu, MingTing; Schmitz, Greg; Chen, Rich; Arabagi, Veaceslav; del Nido, Pedro J.; Dupont, Pierre E.

    2013-01-01

    A novel robotic tool is proposed to enable the surgical removal of tissue from inside the beating heart. The tool is manufactured using a unique metal MEMS process that provides the means to fabricate fully assembled devices that incorporate micron-scale features in a millimeter scale tool. The tool is integrated with a steerable curved concentric tube robot that can enter the heart through the vasculature. Incorporating both irrigation and aspiration, the tissue removal system is capable of extracting substantial amounts of tissue under teleoperated control by first morselizing it and then transporting the debris out of the heart through the lumen of the robot. Tool design and robotic integration are described and ex vivo experimental results are presented. PMID:24232076

  18. Metals Removed by Outflows from Milky Way Dwarf Spheroidal Galaxies

    NASA Astrophysics Data System (ADS)

    Kirby, Evan N.; Martin, Crystal L.; Finlator, Kristian

    2011-12-01

    The stars in the dwarf spheroidal satellite galaxies (dSphs) of the Milky Way are significantly more metal-poor than would be expected from a closed box model of chemical evolution. Gas outflows likely carried away most of the metals produced by the dSphs. Based on previous Keck/DEIMOS observations and models, we calculate the mass in Mg, Si, Ca, and Fe expelled from each of eight dSphs. Essentially, these masses are the differences between the observed amount of metals present in the dSphs' stars today and the inferred amount of metals produced by supernovae. We conclude that the dSphs lost 96% to >99% of the metals their stars manufactured. We apply the observed mass function of Milky Way dSphs to the ejected mass function to determine that a single large dSph, like Fornax, lost more metals over 10 Gyr than all smaller dSphs combined. Therefore, small galaxies like dSphs are not significant contributors to the metal content of the intergalactic medium. Finally, we compare our ejected mass function to previous X-ray measurements of the metal content of the winds from the post-starburst dwarf irregular galaxy NGC 1569. Remarkably, the most recent starburst in that galaxy falls exactly on the ejected-mass-stellar-mass relation defined by the Milky Way dSphs. The data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

  19. Removal of heavy metals from mine waters by natural zeolites

    SciTech Connect

    Ulla Wingenfelder; Carsten Hansen; Gerhard Furrer; Rainer Schulin

    2005-06-15

    The study investigated the removal of Fe, Pb, Cd, and Zn from synthetic mine waters by a natural zeolite. The emphasis was given to the zeolite's behavior toward a few cations in competition with each other. Pb was removed efficiently from neutral as well as from acidic solutions, whereas the uptake of Zn and Cd decreased with low pH and high iron concentrations. With increasing Ca concentrations in solution, elimination of Zn and Cd became poorer while removal of Pb remained virtually unchanged. The zeolite was stable in acidic solutions. Disintegration was only observed below pH 2.0. Forward- and back-titration of synthetic acidic mine water were carried out in the presence and absence of zeolite to simulate the effects of a pH increase by addition of neutralizing agents and a re-acidification which can be caused by subsequent mixing with acidic water. The pH increase during neutralization causes precipitation of hydrous ferric oxides and decreased dissolved metal concentrations. Zeolite addition further diminished Pb concentrations but did not have an effect on Zn and Cd concentrations in solution. During re-acidification of the solution, remobilization of Pb was weaker in the presence than in the absence of zeolite. No substantial differences were observed for Fe, Cd, and Zn immobilization. The immobilization of the metals during pH increase and the subsequent remobilization caused by re-acidification can be well described by a geochemical equilibrium speciation model that accounts for metal complexation at hydrous ferric oxides, for ion exchange on the zeolite surfaces, as well as for dissolution and precipitation processes. 42 refs., 5 figs., 3 tabs.

  20. Utilization of pulp and paper industrial wastes to remove heavy metals from metal finishing wastewater.

    PubMed

    Sthiannopkao, Suthipong; Sreesai, Siranee

    2009-08-01

    Two pulp and paper industrial wastes, lime mud (LM) and recovery boiler ash (RB), have low moisture contents, low heavy metal contaminations and contain various carbonate compounds which contribute to a high pH. Metal finishing wastewater (MF-WW) has a low pH, high levels of TDS and high contaminations from Cr, Cu, Pb and Zn. The heavy metals from MF-WW were removed by sorption and precipitation mechanisms. LM gave better results in removing heavy metals from MF-WW than RB. At a reaction time of 45min, the maximum removal efficiencies for Cr (93%) and Cu (99%) were obtained at 110gL(-1) of LM, but at 80gL(-1) for Pb (96%) and Zn (99%). Treatment with LM gives a higher sludge volume than with RB. However, the leachability of heavy metals from LM is lower. Leachability of heavy metals in the sediment for all selected treatment conditions is within government standards. PMID:19501952

  1. Heavy metal removal from water/wastewater by nanosized metal oxides: a review.

    PubMed

    Hua, Ming; Zhang, Shujuan; Pan, Bingcai; Zhang, Weiming; Lv, Lu; Zhang, Quanxing

    2012-04-15

    Nanosized metal oxides (NMOs), including nanosized ferric oxides, manganese oxides, aluminum oxides, titanium oxides, magnesium oxides and cerium oxides, provide high surface area and specific affinity for heavy metal adsorption from aqueous systems. To date, it has become a hot topic to develop new technologies to synthesize NMOs, to evaluate their removal of heavy metals under varying experimental conditions, to reveal the underlying mechanism responsible for metal removal based on modern analytical techniques (XAS, ATR-FT-IR, NMR, etc.) or mathematical models, and to develop metal oxide-based materials of better applicability for practical use (such as granular oxides or composite materials). The present review mainly focuses on NMOs' preparation, their physicochemical properties, adsorption characteristics and mechanism, as well as their application in heavy metal removal. In addition, porous host supported NMOs are particularly concerned because of their great advantages for practical application as compared to the original NMOs. Also, some magnetic NMOs were included due to their unique separation performance. PMID:22018872

  2. Mineral Adsorbents for Removal of Metals in Urban Runoff

    NASA Astrophysics Data System (ADS)

    Bjorklund, Karin; Li, Loretta

    2014-05-01

    The aim of this research was to determine the capacity of four different soil minerals to adsorb metals frequently detected in urban runoff. These are low-cost, natural and commercially available soil minerals. Contaminated surface runoff from urban areas is a major cause of concern for water quality and aquatic ecosystems worldwide. Pollution in urban areas is generated by a wide array of non-point sources, including vehicular transportation and building materials. Some of the most frequently detected pollutants in urban runoff are metals. Exhaust gases, tire wear and brake linings are major sources of such metals as Pb, Zn and Cu, while impregnated wood, plastics and galvanized surfaces may release As, Cd, Cr and Zn. Many metals have toxic effects on aquatic plants and animals, depending on metal speciation and bioavailability. The removal efficiency of pollutants in stormwater depends on treatment practices and on the properties the pollutant. The distribution of metals in urban runoff has shown, for example, that Pb is predominantly particle-associated, whereas Zn and Cd are present mainly in dissolved form. Many metals are also attached to colloids, which may act as carriers for contaminants, thereby facilitating their transport through conventional water treatment processes. Filtration of stormwater is one of the most promising techniques for removal of particulates, colloidal and truly dissolved pollutants, provided that effective filtration and adsorption media are used. Filtration and infiltration are used in a wide array of stormwater treatment methods e.g. porous paving, infiltration drains and rain gardens. Several soil minerals were investigated for their potential as stormwater filter materials. Laboratory batch tests were conducted to determine the adsorption capacity of these minerals. A synthetic stormwater was tested, with spiked concentrations corresponding to levels reported in urban runoff, ranging from 50-1,500 µg/L for Zn; 5-250 µg/L for Cu

  3. Nanomagnetic chelators for removal of toxic metal ions

    NASA Astrophysics Data System (ADS)

    Singh, Sarika; Barick, K. C.; Bahadur, D.

    2013-02-01

    Ethylenediamine trtraaceteic acid (EDTA) functionalized Fe3O4 nanomagnetic chelators (NMCs) were synthesized by co-precipitation method followed by in-situ grafting of EDTA. XRD and TEM analyses reveal the formation of highly crystalline single-phase Fe3O4 nanoparticles of size about 10 nm. Surface functionalization of Fe3O4 with EDTA was evident from FTIR spectroscopy, TGA analysis and zeta-potential measurement. These NMCs exhibit superparamagnetic behavior at room temperature with strong field dependent magnetic responsivity. It has been observed that NMCs have strong tendency for adsorption of various toxic metal ions (Ni2+, Cr3+, Cu2+, Cd2+, Co2+ and Pb2+) from waste-water. Furthermore, these magnetic chelators can be used as highly efficient separable and reusable material for removal of toxic metal ions.

  4. FINAL REPORT. HEAVY METAL PUMPS IN PLANTS

    EPA Science Inventory

    The long term goal of the funded research is to understand how heavy metals are taken up from the soil and translocated throughout the plant. The potential application of this research is to create plants with better heavy metal uptake systems and thereby improve the ability of t...

  5. Eggshell: A green adsorbent for heavy metal removal in an MBR system.

    PubMed

    Pettinato, M; Chakraborty, S; Arafat, Hassan A; Calabro', V

    2015-11-01

    Presence of heavy metals as well as different metal ions in treated wastewater is a problem for the environment as well as human health. This paper aims to investigate the possibility to combine an MBR (membrane biological reactor) with an adsorption process onto powdered eggshell and eggshell membrane in order to improve metal removal from wastewater. The first step of the experimental analysis consists of the evaluation of the compatibility between the two processes. Then, a study about sorbent concentration and size effect on fouling was conducted, because the use of this kind of sorbent could affect membrane performance. The second step of the work concerns the check up of eggshell removal capacity as a function of sorbent size, achieved treating an aqueous solution containing Al(3+), Fe(2+) and Zn(2+) as water pollutants. Finally, synthetic wastewater, containing the metal species, was treated by two alternative process schemes: one of them performs the metal uptake in a dedicated adsorption unit, before the MBR. In the second, the two processes take place in the same unit. Results demonstrate that the optimization of the first option could be a solution to MBR upgrading. PMID:26117278

  6. Pentek metal coating removal system: Baseline report; Summary

    SciTech Connect

    1997-07-31

    The Pentek metal coating removal system consists of the ROTO-PEEN Scaler, CORNER-CUTTER(R), and VAC-PAC(R). The system is designed to remove coatings from steel, concrete, brick, and wood. The Scaler uses 3M ROTO-PEEN tungsten carbide cutters, while the CORNER-CUTTER(R) uses solid needles for descaling activities. These are used with the VAC-PAC(R) vacuum system to capture dust and debris as removal of the coating takes place. The safety and health evaluation during the testing demonstration focused on two main areas of exposure: dust and noise. Dust exposure was minimal, but noise exposure was significant. Further testing for each exposure is recommended, since the outdoor environment where the testing demonstration took place may skew the results. It is feasible that dust and noise levels will be higher in an enclosed operating environment. Other areas of concern found were arm-hand vibration, whole-body vibration, ergonomics, heat stress, tripping hazards, electrical hazards, machine guarding, and lockout/tagout.

  7. A feasibility study on bioelectrokinetics for the removal of heavy metals from tailing soil.

    PubMed

    Lee, Keun-Young; Kim, Hyun-A; Lee, Byung-Tae; Kim, Soon-Oh; Kwon, Young-Ho; Kim, Kyoung-Woong

    2011-01-01

    The combination of bioremediation and electrokinetics, termed bioelectrokinetics, has been studied constantly to enhance the removal of organic and inorganic contaminants from soil. The use of the bioleaching process originating from Fe- and/or S-oxidizing bacteria may be a feasible technology for the remediation of heavy metal-contaminated soils. In this study, the bioleaching process driven by injection of S-oxidizing bacteria, Acidithiobacillus thiooxidans, was evaluated as a pre-treatment step. The bioleaching process was sequentially integrated with the electrokinetic soil process, and the final removal efficiency of the combined process was compared with those of individual processes. Tailing soil, heavily contaminated with Cd, Cu, Pb, Zn, Co, and As, was collected from an abandoned mine area in Korea. The results of geochemical studies supported that this tailing soil contains the reduced forms of sulfur that can be an energy source for A. thiooxidans. From the result of the combined process, we could conclude that the bioleaching process might be a good pre-treatment step to mobilize heavy metals in tailing soil. Additionally, the electrokinetic process can be an effective technology for the removal of heavy metals from tailing soil. For the sake of generalizing the proposed bioelectrokinetic process, however, the site-specific differences in soil should be taken into account in future studies. PMID:21046430

  8. Water treatment process and system for metals removal using Saccharomyces cerevisiae

    DOEpatents

    Krauter, Paula A. W.; Krauter, Gordon W.

    2002-01-01

    A process and a system for removal of metals from ground water or from soil by bioreducing or bioaccumulating the metals using metal tolerant microorganisms Saccharomyces cerevisiae. Saccharomyces cerevisiae is tolerant to the metals, able to bioreduce the metals to the less toxic state and to accumulate them. The process and the system is useful for removal or substantial reduction of levels of chromium, molybdenum, cobalt, zinc, nickel, calcium, strontium, mercury and copper in water.

  9. Biofilms Versus Activated Sludge: Considerations in Metal and Metal Oxide Nanoparticle Removal from Wastewater.

    PubMed

    Walden, Connie; Zhang, Wen

    2016-08-16

    The increasing application of metal and metal oxide nanoparticles [Me(O)NPs] in consumer products has led to a growth in concentration of these nanoparticles in wastewater as emerging contaminants. This may pose a threat to ecological communities (e.g., biological nutrient removal units) within treatment plants and those subject to wastewater effluents. Here, the toxicity, fate, and process implications of Me(O)NPs within wastewater treatment, specifically during activated sludge processing and biofilm systems are reviewed and compared. Research showed activated sludge achieves high removal rate of Me(O)NPs by the formation of aggregates through adsorption. However, recent literature reveals evidence that inhibition is likely for nutrient removal capabilities such as nitrification. Biofilm systems were much less studied, but show potential to resist Me(O)NP inhibition and achieve removal through possible retention by sorption. Implicating factors during bacteria-Me(O)NP interactions such as aggregation, surface functionalization, and the presence of organics are summarized. At current modeled levels, neither activated sludge nor biofilm systems can achieve complete removal of Me(O)NPs, thus allowing for long-term environmental exposure of diverse biological communities to Me(O)NPs in streams receiving wastewater effluents. Future research directions are identified throughout in order to minimize the impact of these nanoparticles released. PMID:27437755

  10. Economic feasibility of biochemical processes for the upgrading of crudes and the removal of sulfur, nitrogen, and trace metals from crude oil -- Benchmark cost establishment of biochemical processes on the basis of conventional downstream technologies. Final report FY95

    SciTech Connect

    Premuzic, E.T.

    1996-08-01

    During the past several years, a considerable amount of work has been carried out showing that microbially enhanced oil recovery (MEOR) is promising and the resulting biotechnology may be deliverable. At Brookhaven National Laboratory (BNL), systematic studies have been conducted which dealt with the effects of thermophilic and thermoadapted bacteria on the chemical and physical properties of selected types of crude oils at elevated temperatures and pressures. Current studies indicate that during the biotreatment several chemical and physical properties of crude oils are affected. The oils are (1) emulsified; (2) acidified; (3) there is a qualitative and quantitative change in light and heavy fractions of the crudes; (4) there are chemical changes in fractions containing sulfur compounds; (5) there is an apparent reduction in the concentration of trace metals; and (6) the qualitative and quantitative changes appear to be microbial species dependent; and (7) there is a distinction between biodegraded and biotreated oils. The downstream biotechnological crude oil processing research performed thus far is of laboratory scale and has focused on demonstrating the technical feasibility of downstream processing with different types of biocatalysts under a variety of processing conditions. Quantitative economic analysis is the topic of the present project which investigates the economic feasibility of the various biochemical downstream processes which hold promise in upgrading of heavy crudes, such as those found in California, e.g., Monterey-type, Midway Sunset, Honda crudes, and others.

  11. CPP-603 Chloride Removal System Decontamination and Decommissioning. Final report

    SciTech Connect

    Moser, C.L.

    1993-02-01

    The CPP-603 (annex) Chloride Removal System (CRS) Decontamination and Decommissioning (D&D) Project is described in this report. The CRS was used for removing Chloride ions and other contaminants that were suspended in the waters of the underwater fuel storage basins in the CPP-603 Fuel Receiving and Storage Facility (FRSF) from 1975 to 1981. The Environmental Checklist and related documents, facility characterization, decision analysis`, and D&D plans` were prepared in 1991. Physical D&D activities were begun in mid summer of 1992 and were completed by the end of November 1992. All process equipment and electrical equipment were removed from the annex following accepted asbestos and radiological contamination removal practices. The D&D activities were performed in a manner such that no radiological health or safety hazard to the public or to personnel at the Idaho National Engineering Laboratory (INEL) occurred.

  12. Removal mechanisms of heavy metal pollution from urban runoff in wetlands

    NASA Astrophysics Data System (ADS)

    Zhang, Zhiming; Cui, Baoshan; Fan, Xiaoyun

    2012-12-01

    Solid particles, particularly urban surface dust in urban environments contain large quantities of pollutants. It is considered that urban surface dust is a major pollution source of urban stormwater runoff. The stormwater runoff washes away urban surface dust and dissolves pollutants adsorbed onto the dust and finally discharges into receiving water bodies. The quality of receiving water bodies can be deteriorated by the dust and pollutants in it. Polluted waters can be purified by wetlands with various physical, chemical, and biologic processes. These processes have been employed to treat pollutants in urban stormwater runoff for many years because purification of treatment wetlands is a natural process and a low-cost method. In this paper, we reviewed the processes involved during pollutants transport in urban environments. Particularly, when the urban stormwater runoff enters into wetlands, their removal mechanisms involving various physical, chemical and biologic processes should been understood. Wetlands can remove heavy metals by absorbing and binding them and make them form a part of sediment. However, heavy metals can be released into water when the conditions changed. This information is important for the use of wetlands for removing of pollutants and reusing stormwater.

  13. Final Report: Metal Perhydrides for Hydrogen Storage

    SciTech Connect

    Hwang, J-Y.; Shi, S.; Hackney, S.; Swenson, D.; Hu, Y.

    2011-07-26

    Hydrogen is a promising energy source for the future economy due to its environmental friendliness. One of the important obstacles for the utilization of hydrogen as a fuel source for applications such as fuel cells is the storage of hydrogen. In the infrastructure of the expected hydrogen economy, hydrogen storage is one of the key enabling technologies. Although hydrogen possesses the highest gravimetric energy content (142 KJ/g) of all fuels, its volumetric energy density (8 MJ/L) is very low. It is desired to increase the volumetric energy density of hydrogen in a system to satisfy various applications. Research on hydrogen storage has been pursed for many years. Various storage technologies, including liquefaction, compression, metal hydride, chemical hydride, and adsorption, have been examined. Liquefaction and high pressure compression are not desired due to concerns related to complicated devices, high energy cost and safety. Metal hydrides and chemical hydrides have high gravimetric and volumetric energy densities but encounter issues because high temperature is required for the release of hydrogen, due to the strong bonding of hydrogen in the compounds. Reversibility of hydrogen loading and unloading is another concern. Adsorption of hydrogen on high surface area sorbents such as activated carbon and organic metal frameworks does not have the reversibility problem. But on the other hand, the weak force (primarily the van der Waals force) between hydrogen and the sorbent yields a very small amount of adsorption capacity at ambient temperature. Significant storage capacity can only be achieved at low temperatures such as 77K. The use of liquid nitrogen in a hydrogen storage system is not practical. Perhydrides are proposed as novel hydrogen storage materials that may overcome barriers slowing advances to a hydrogen fuel economy. In conventional hydrides, e.g. metal hydrides, the number of hydrogen atoms equals the total valence of the metal ions. One Li

  14. Biodegradable polymer based ternary blends for removal of trace metals from simulated industrial wastewater.

    PubMed

    Prakash, N; Arungalai Vendan, S

    2016-02-01

    The ternary blends consisting of Chitosan (CS), Nylon 6 (Ny 6) and Montmorillonite clay (MM clay) were prepared by the solution blending method with glutaraldehyde. The prepared ternary blends were characterization by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Thermo gravimetric analysis (TGA), Differential scanning calorimetry (DSC) and Scanning electron microscope (SEM). The FTIR results showed that the strong intermolecular hydrogen bondings were established between chitosan, nylon 6 and montmorillonite clay. TGA showed the thermal stability of the blend is enhanced by glutaraldehyde as Crosslink agent. Results of XRD indicated that the relative crystalline of the pure chitosan film was reduced when the polymeric network was reticulated by glutaraldehyde. Finally, the results of scanning electron microscopy (SEM) indicated that the morphology of the blend was rough and heterogenous. Further, it confirms the interaction between the functional groups of the blend components. The extent of removal of the trace metals was found to be almost the same. The removal of these metals at different pH was also done and the maximum removal of the metals was observed at pH 4.5 for both trace metals. Adsorption studies and kinetic analysis have also been made. Moreover, the protonation of amine groups is induced an electrostatic repulsion of cations. When the pH of the solution was more than 5.5, the sorption rate began to decrease. Besides, the quantity of adsorbate on absorbent was fitted as a function in Langmuir and Freundlich isotherm. The sorption kinetics was tested for pseudo first order and pseudo second order reaction. The kinetic experimental data correlated with the second order kinetic model and rate constants of sorption for kinetic models were calculated and accordingly, the correlation coefficients were obtained. PMID:26432371

  15. Removal and recovery of toxic metal ions from aqueous waste sites using polymer pendant ligands

    SciTech Connect

    Fish, D.

    1996-10-01

    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.

  16. Composites for removing metals and volatile organic compounds and method thereof

    DOEpatents

    Coronado, Paul R.; Coleman, Sabre J.; Reynolds, John G.

    2006-12-12

    Functionalized hydrophobic aerogel/solid support structure composites have been developed to remove metals and organic compounds from aqueous and vapor media. The targeted metals and organics are removed by passing the aqueous or vapor phase through the composite which can be in molded, granular, or powder form. The composites adsorb the metals and the organics leaving a purified aqueous or vapor stream. The species-specific adsorption occurs through specific functionalization of the aerogels tailored towards specific metals and/or organics. After adsorption, the composites can be disposed of or the targeted metals and/or organics can be reclaimed or removed and the composites recycled.

  17. Heavy metals removal from aqueous solutions and wastewaters by using various byproducts.

    PubMed

    Shaheen, Sabry M; Eissa, Fawzy I; Ghanem, Khaled M; Gamal El-Din, Hala M; Al Anany, Fathia S

    2013-10-15

    Water contamination with heavy metals (HM) represents a potential threat to humans, animals and plants, and thus removal of these metals from contaminated waters has received increasing attention. The present study aimed to assess the efficiency of some low cost sorbents i.e., chitosan (CH), egg shell (ES), humate potassium (HK), and sugar beet factory lime (SBFL) for removal of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) from wastewaters. For this purpose batch equilibrium experiments were conducted with aqueous solutions containing various concentrations of the metals and sorbents in a mono-metal and competitive sorption system. Sorption isotherms were developed, and sorption parameters were determined. The potential applicability of the tested sorbents in the removal of Cd, Cu, and Zn from contaminated wastewaters was also investigated by equilibrating different sorbents and water ratios. Chitosan expressed the highest affinity for the metals followed by SBFL, ES, and HK. Nearly 100% of the metals were removed from aqueous solutions with the lowest initial metal concentrations by the sorbents especially CH and SBFL. However, the sorption efficiency decreased as the initial metal concentrations increased. Competition among the four metals changed significantly their distribution coefficient (Kd) values with the sorbents. The selectivity sequence of the metals was: Pb > Cu > Zn > Cd. The metal removal from the wastewaters varied from 72, 69, and 60 to nearly 100% for Cd, Cu and Zn, respectively. The efficiency of the studied byproducts in removing metals from the wastewaters differed based on the source of contamination and metal concentrations. Cadmium removal percentages by HK and CH were higher than SBFL and ES. The HK and CH exhibited the highest removal percentage of Cu from water with high concentrations. The SBFL and ES revealed the highest removal percentage of Zn from water with high concentrations. The results, demonstrate a high potential

  18. Simultaneous removal of oil and grease, and heavy metals from artificial bilge water using electro-coagulation/flotation.

    PubMed

    Rincón, Guillermo J; La Motta, Enrique J

    2014-11-01

    US and international regulations pertaining to the control of bilge water discharges from ships have concentrated their attention to the levels of oil and grease rather than to the heavy metal concentrations. The consensus is that any discharge of bilge water (and oily water emulsion within 12 nautical miles from the nearest land cannot exceed 15 parts per million (ppm). Since there is no specific regulation for metal pollutants under the bilge water section, reference standards regulating heavy metal concentrations are taken from the ambient water quality criteria to protect aquatic life. The research herein presented discusses electro-coagulation (EC) as a method to treat bilge water, with a focus on oily emulsions and heavy metals (copper, nickel and zinc) removal efficiency. Experiments were run using a continuous flow reactor, manufactured by Ecolotron, Inc., and a synthetic emulsion as artificial bilge water. The synthetic emulsion contained 5000 mg/L of oil and grease, 5 mg/L of copper, 1.5 mg/L of nickel, and 2.5 mg/l of zinc. The experimental results demonstrate that EC is very efficient in removing oil and grease. For oil and grease removal, the best treatment and cost efficiency was obtained when using a combination of carbon steel and aluminum electrodes, at a detention time less than one minute, a flow rate of 1 L/min and 0.6 A/cm(2) of current density. The final effluent oil and grease concentration, before filtration, was always less than 10 mg/L. For heavy metal removal, the combination of aluminum and carbon steel electrodes, flow rate of 1 L/min, effluent recycling, and 7.5 amps produced 99% zinc removal efficiency. Copper and nickel are harder to remove, and a removal efficiency of 70% was achieved. PMID:24908614

  19. Final design of a space debris removal system

    NASA Technical Reports Server (NTRS)

    Carlson, Erika; Casali, Steve; Chambers, Don; Geissler, Garner; Lalich, Andrew; Leipold, Manfred; Mach, Richard; Parry, John; Weems, Foley

    1990-01-01

    The objective is the removal of medium sized orbital debris in low Earth orbits. The design incorporates a transfer vehicle and a netting vehicle to capture the medium size debris. The system is based near an operational space station located at 28.5 degrees inclination and 400 km altitude. The system uses ground based tracking to determine the location of a satellite breakup or debris cloud. This data is unloaded to the transfer vehicle, and the transfer vehicle proceeds to rendezvous with the debris at a lower altitude parking orbit. Next, the netting vehicle is deployed, tracks the targeted debris, and captures it. After expending the available nets, the netting vehicle returns to the transfer vehicle for a new netting module and continues to capture more debris in the target area. Once all the netting modules are expended, the transfer vehicle returns to the space station's orbit, where it is resupplied with new netting modules from a space shuttle load. The new modules are launched by the shuttle from the ground, and the expended modules are taken back to Earth for removal of the captured debris, refueling, and repacking of the nets. Once the netting modules are refurbished, they are taken back into orbit for reuse. In a typical mission, the system has the ability to capture 50 pieces of orbital debris. One mission will take about six months. The system is designed to allow for a 30 degree inclination change on the outgoing and incoming trips of the transfer vehicle.

  20. Removal of trabecular metal osteonecrosis intervention implant and conversion to primary total hip arthroplasty.

    PubMed

    Owens, Joshua B; Ely, Erin E; Guilliani, Nathania M Figueroa; Suarez, Juan C; Patel, Preetesh D

    2012-06-01

    Core decompression and placement of the Trabecular Metal Osteonecrosis Intervention Implant have shown to be initially successful in treating early osteonecrosis. When treatment fails, however, patients often undergo primary total hip arthroplasty (THA) requiring removal of a previously inserted trabecular metal implant. We describe a technical tip for removal of a well-ingrown trabecular metal screw. A metal-cutting trephine placed over the screw allows for removal in an efficient manner while minimizing additional dissection and bone loss during conversion to THA. PMID:22425306

  1. UTILITY OF ZEOLITES IN HAZARDOUS METAL REMOVAL FROM WATER

    EPA Science Inventory

    Zeolites are well known for their ion exchange, adsorption and acid catalysis properties. Different inorganic pollutants have been removed from water at room temperature by using synthetic zeolites. Zeolite Faujasite Y has been used to remove inorganic pollutants including arseni...

  2. In-situ electrochemical method for removing environmental pollutants. Final report on Phase 1

    SciTech Connect

    Walsh, F.W.; Morris, R.S.

    1983-04-01

    Research was undertaken to determine whether certain organometallics can be used as catalysts in the electrochemical hydroxylation of chlorinated organic pollutants such as polychlorinated biphenols (PCBs). The rate and extent of PCB homolog removal by catalyzed electrochemistry in aqueous solutions were studied. The effect of electrolyte pH, constituent ions, and oxygen content, as well as the metal center in the organometallic catalyst, on PCB removal was evaluated. Electrochemical removal of PCBs on catalyzed-carbon electrodes was found to be technically feasible with lower chlorination PCB homologs being rapidly removed by specific catalysts.

  3. To study the recovery of L-Cysteine using halloysite nanotubes after heavy metal removal

    NASA Astrophysics Data System (ADS)

    Thakur, Juhi

    2016-04-01

    Industrial wastes are a major source of soil and water pollution that originate from mining industries, chemical industries, metal processing industries, etc. These wastes consist of a variety of chemicals including phenolics, heavy metals, etc. Use of industrial effluent and sewage sludge on agricultural land has become a common practice in the world which results in these toxic metals being transferred and ultimately concentrate in plant tissues from water and the soil. The metals that get accumulated, prove detrimental to plants themselves and may also cause damage to the healths of animals as well as man. This is because the heavy metals become toxins above certain concentrations, over a narrow range. As a further matter, these metals negatively affect the natural microbial populations as well, that leads to the disruption of fundamental ecological processes. However, many techniques and methods have been advanced to clear the heavy metal polluted soils and waters. One important method is by removing heavy metals with the help of amino acids like L-Cysteine and L-Penicillamine. But also, economy of removal of pollutant heavy metals from soils and waters is a major concern. Present study helps in decreasing the cost for large-scale removal of heavy metals from polluted water by recovering the amino acid (L-Cysteine) after removal of nickel (Ni+2) at a fixed pH, by binding the Ni+2 with halloysite nanotubes(HNT), so that L-Cysteine can be reused again for removal of heavy metals.

  4. Triboelectrification-Enabled Self-Powered Detection and Removal of Heavy Metal Ions in Wastewater.

    PubMed

    Li, Zhaoling; Chen, Jun; Guo, Hengyu; Fan, Xing; Wen, Zhen; Yeh, Min-Hsin; Yu, Chongwen; Cao, Xia; Wang, Zhong Lin

    2016-04-01

    A fundamentally new working principle into the field of self-powered heavy-metal-ion detection and removal using the triboelectrification effect is introduced. The as-developed tribo-nanosensors can selectively detect common heavy metal ions. The water-driven triboelectric nanogenerator is taken as a sustainable power source for heavy-metal-ion removal by recycling the kinetic energy from flowing wastewater. PMID:26913810

  5. Final Removal Action Report of the CPP-603A Basin Facility

    SciTech Connect

    D. V. Croson

    2007-01-04

    This Final Removal Action Report describes the actions that were taken under the non-time-critical removal action recommended in the Action Memorandum for the Non-Time Critical Removal Action at the CPP-603A Basins, Idaho Nuclear Technology and Engineering Center, as evaluated in the Engineering Evaluation/Cost Analysis for the CPP-603A Bason Non-Time Critical Removal Action, Idaho Nuclear Technology and Engineering Center. The Removal Action implemented consolidation and recording the location of debris objects containing radioactive cobalt (cobalt-60), removal and management of a small high-activity debris object (SHADO 1), the removal, treatment, and disposal of the basin water at the Idaho CERCLA Disposal Facility (ICDF) evaporation ponds, and filling the basins with grout/controlled low strength material.

  6. Cyclic electrowinning/precipitation (CEP) system for the removal of heavy metal mixtures from aqueous solutions

    PubMed Central

    Grimshaw, Pengpeng; Calo, Joseph M.; Hradil, George

    2011-01-01

    The description and operation of a novel cyclic electrowinning/precipitation (CEP) system for the simultaneous removal of mixtures of heavy metals from aqueous solutions are presented. CEP combines the advantages of electrowinning in a spouted particulate electrode (SPE) with that of chemical precipitation and redissolution, to remove heavy metals at low concentrations as solid metal deposits on particulate cathode particles without exporting toxic metal precipitate sludges from the process. The overall result is very large volume reduction of the heavy metal contaminants as a solid metal deposit on particles that can either be safely discarded as such, or further processed to recover particular metals. The performance of this system is demonstrated with data on the removal of mixtures of copper, nickel, and cadmium from aqueous solutions. PMID:22102792

  7. Cyclic electrowinning/precipitation (CEP) system for the removal of heavy metal mixtures from aqueous solutions.

    PubMed

    Grimshaw, Pengpeng; Calo, Joseph M; Hradil, George

    2011-11-15

    The description and operation of a novel cyclic electrowinning/precipitation (CEP) system for the simultaneous removal of mixtures of heavy metals from aqueous solutions are presented. CEP combines the advantages of electrowinning in a spouted particulate electrode (SPE) with that of chemical precipitation and redissolution, to remove heavy metals at low concentrations as solid metal deposits on particulate cathode particles without exporting toxic metal precipitate sludges from the process. The overall result is very large volume reduction of the heavy metal contaminants as a solid metal deposit on particles that can either be safely discarded as such, or further processed to recover particular metals. The performance of this system is demonstrated with data on the removal of mixtures of copper, nickel, and cadmium from aqueous solutions. PMID:22102792

  8. Dynamic simulation of sulfur-removal systems. Final report

    SciTech Connect

    Alexander, J.H.; Blake, T.R.; Brownell, D.H. Jr.; Henline, W.D.; Wilkins, D.E.

    1982-01-01

    A generalized computer simulation has been developed to predict the dynamic response of alternate gas absorption systems for selective removal of sulfur compounds or ammonia from fuel gas or synthesis gas produced from coal or other fossil fuels. The models use numerical methods based upon finite difference techniques to determine the spatial distribution of process variables within both the absorption and regeneration columns of such gas cleanup processes. The simulator may be applied to systems for selective gas absorption based on either chemical or physical principles. Examples of such systems include the Benfield process based on absorption by chemical reaction with an activated alkali carbonate solvent, and the Allied SELEXOL Solvent Process based on physical absorption as a result of partial pressure differences of the gas components above an organic solvent system. Simulations of either individual process units or an entire integrated plant can be performed. This computer program has specifically been structured to permit convenient flow sheet modification, as well as addition of new units. This research has emphasized the development of a general theoretical structure which can be easily modified by substituting alternate sets of data on the physicochemical properties of the appropriate liquid solvent. This model has been applied to Selexol Solvent Processes using both published and proprietary data on solvent properties. Test calculations have been performed to simulate open loop response of individual scrubber towers, and the complete system, to input composition and flow rate transients.

  9. Biotechnology for removal of carbon disulfide emissions. Final report

    SciTech Connect

    McIntosh, M.J.

    1995-07-01

    Biological removal in a ``biofilter`` plant of carbon disulfide and hydrogen sulfide from the air effluent of a viscose plant at Teepak, Inc., is analyzed from process and economic standpoints by use of the Aspen Plus simulation program. The metabolic product from the biofilter, 3% sulfuric acid, must be transformed at the source into either a marketable or recyclable commodity (such as 95% sulfuric acid, high-quality sulfur, or high-quality gypsum) or a material with reasonable landfill costs (such as sulfur or gypsum). The simulations indicate that the total capital requirement for production of concentrated sulfuric acid is $48.9 million; for high-quality gypsum, $40.4 million; and for high-quality sulfur, $29.4 million. Production of concentrated sulfur for landfill is not economically practical. The process to neutralize the 3% acid effluent with limestone and landfill the resulting low-quality gypsum requires the lowest total investment of the processes simulated, $8.7 million, including the biofilter plant.

  10. Removal of metal and organic pollutants from wastewater by a sequential selective technique.

    PubMed

    Cobas, M; Danko, A S; Pazos, M; Sanromán, M A

    2016-08-01

    In this study the application of a sequential selective system that combined biosorption with biodegradation was evaluated as a feasible process for the removal of Cr(VI) and m-cresol from effluents. Cr(VI) biosorption on pretreated chestnut shells showed 100% metal removal and modelling efforts demonstrated that the pseudo-second order kinetic model and Langmuir isotherm fit well the process behaviour. Thus, the treated stream was an appropriate environment for the biodegradation of m-cresol using a laccase-producer fungus, Phlebia radiata. Two bioreactor configurations, rotating drum and modified-airlift, were studied using the fungus grown on chestnut shells, which act as support-substrate as well as oxidative enzyme inductor increasing the laccase activity up to 1000UL(-1). The best bioreactor, rotating drum, reached 100% removal in 7days. Finally, the best configuration for the sequential selective system was modelled operating in continuous mode by the breakthrough curves generated using FASTv2.0 and the design bioreactor flow model. PMID:26897470

  11. Comparative efficiency of final endodontic cleansing procedures in removing a radioactive albumin from root canal systems

    SciTech Connect

    Cecic, P.A.; Peters, D.D.; Grower, M.F.

    1984-09-01

    Fifty-six teeth were initially instrumented, with the use of seven irrigants or irrigant combinations, and filled with radioactive albumin. The study then showed the relative ability of three final endodontic procedures (copious reirrigation with saline solution, drying with paper points, and reassuring patency of the canal with the final instrument) to remove the albumin. Even after copious irrigation, each additional procedure removed statistically significant amounts of albumin. Alternating an organic solvent and an inorganic solvent did appear to leave the canal system in the optimal condition for final cleansing procedures. The study then correlated the relative efficiency of irrigation alone versus instrumentation plus irrigation in removing the remaining albumin from the canal systems. Reinstrumentation plus copious irrigation removed significantly more albumin than copious irrigation alone.

  12. New biosorbent in removing some metals from industrial wastewater in El Mex Bay, Egypt

    NASA Astrophysics Data System (ADS)

    Abdallah, Maha Ahmed Mohamed; Mahmoud, Mohamed E.; Osman, Maher M.; Ahmed, Somaia B.

    2015-12-01

    Biosorption is an extensive technology applied for the removal of heavy metal ions and other pollutants from aqueous solutions. In the present study, the biosorption of cadmium, lead, chromium and mercury ions from polluted surface seawater in El-Max Bay was determined using hybrid active carbon sorbents. These sorbents were treated chemically by acid, base and redox reaction followed by surface loading of baker's yeast biomass for increasing their biosorption capacity and the highest metal uptake values. The surface function and morphology of the hybrid immobilized sorbents were studied by Fourier Transform Infrared analysis and scanning electron microscope imaging. Metal removal values proved that the vital role of baker's yeast as a significant high removable due to functional groups at baker's yeast cell wall surface that have the ability to forming various coordination complexes with metal ions. A noticeable increase in the removal of all studied metals was observed and reached to 100 %.

  13. Removal of heavy metal ions by biogenic hydroxyapatite: Morphology influence and mechanism study

    NASA Astrophysics Data System (ADS)

    Wang, Dandan; Guan, Xiaomei; Huang, Fangzhi; Li, Shikuo; Shen, Yuhua; Chen, Jun; Long, Haibo

    2016-08-01

    Based on the synthesis of hydroxyapatite (HA) with different morphologies, such as nanorod-like, flower-like and sphere-like assembled HA nanorods, a new strategy has been developed for the removal of heavy metal ions such as Pb2+, Cu2+, Mn2+, Zn2+. The dependence of removal efficiency on the morphology and the suspended concentration of trapping agent, the removal time and selectivity were evaluated and discussed. The experimental results proved that the removal capacity of flower-like assembled HA nanorods (NAFL-HA) was the best, and the maximum removal ratio for Pb2+ ion was 99.97%. The mechanism of Pb2+ removal was studied in detail, noting that some metal ions were completely incorporated into hydroxyapatitie to produce Pb-HA. It reveals that the metal ions capture by HA is mainly controlled by sample surface adsorption and co-precipitation, which are directly controlled by sample morphology.

  14. On the mechanism of material removal in nanometric cutting of metallic glass

    NASA Astrophysics Data System (ADS)

    Zhu, Pengzhe; Fang, Fengzhou

    2014-08-01

    Metallic glasses find wide applications in nanotechnology and micro electro-mechanical systems because of their unique physical properties due to their amorphous structures. The material removal mechanism in nanometric cutting of Cu50Zr50, a typical metallic glass, is studied using molecular dynamics method. The chip formation, workpiece deformation and scratching forces under various scratching depths, scratching velocities and temperatures are investigated. The effect of void defect on the cutting behaviors of metallic glass is also explored. The results show that the material removal in nanometric cutting process is based on extrusion instead of shearing, achieving a good understanding of material removal at the nanoscale.

  15. Super-Absorbent polymer gels for oil and grease removal from metal and non-metal surfaces

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this research is to develop a new surface cleaning technology for removal of oil, grease and particulate matters from metal and non-metal surfaces. It is desired that the cleaner is in solid form and is VOC-exempt, HAP-free, non-toxic, non-corrosive, non-ozone depleting, recyclable...

  16. Consolidated Incineration Facility metals partitioning test. Final report

    SciTech Connect

    Burns, D.B.

    1993-08-31

    Test burns were conducted at Energy and Environmental Research Corporation`s rotary kiln simulator, the Solid Waste Incineration Test Facility, using surrogate CIF wastes spiked with hazardous metals and organics. The primary objective for this test program was measuring heavy metals partition between the kiln bottom ash, scrubber blowdown solution, and incinerator stack gas. Also, these secondary waste streams were characterized to determine waste treatment requirements prior to final disposal. These tests were designed to investigate the effect of several parameters on metals partitioning: incineration temperature; waste chloride concentration; waste form (solid or liquid); and chloride concentration in the scrubber water. Tests were conducted at three kiln operating temperatures. Three waste simulants were burned, two solid waste mixtures (paper, plastic, latex, and one with and one without PVC), and a liquid waste mixture (containing benzene and chlorobenzene). Toxic organic and metal compounds were spiked into the simulated wastes to evaluate their fate under various combustion conditions. Kiln offgases were sampled for volatile organic compounds (VOC), semi-volatile organic compounds (SVOC), polychlorinated dibenz[p]dioxins and polychlorinated dibenzofurans (PCDD/PCDF), metals, particulate loading and size distribution, HCl, and combustion products. Stack gas sampling was performed to determine additional treatment requirements prior to final waste disposal. Significant test results are summarized below.

  17. Successful removal of strangulating metal penile ring using a dental handpiece

    PubMed Central

    Etetafia, Mabel Okiemute; Nwajei, Charles Onochie

    2014-01-01

    Background Under emergency conditions, the dental handpiece can be a useful tool for removing a strangulating penile ring. Objective To report the successful use of a dental handpiece (dental drill) to remove a strangulating penile ring in an emergency. Method A case report of a strangulating metal penile ring in a psychiatric patient who presented at the accident and emergency unit of Delta State University Teaching Hospital. Result The metal ring was removed using a diamond bur in a dental handpiece. Conclusions In case of emergency, the dental handpiece is a useful tool for removing a strangulating penile ring. PMID:25015321

  18. Method for removal of metal atoms from aqueous solution using suspended plant cells

    DOEpatents

    Jackson, Paul J.; Torres, deceased, Agapito P.; Delhaize, Emmanuel

    1992-01-01

    The use of plant suspension cultures to remove ionic metallic species and TNT-based explosives and their oxidation products from aqueous solution is described. Several plant strains were investigated including D. innoxia, Citrus citrus, and Black Mexican Sweet Corn. All showed significant ability to remove metal ions. Ions removed to sub-ppm levels include barium, iron, and plutonium. D. innoxia cells growing in media containing weapons effluent contaminated with Ba.sup.2+ also remove TNT, other explosives and oxidation products thereof from solution. The use of dead, dehydrated cells were also found to be of use in treating waste directly.

  19. Removal of anionic metals by amino-organoclay for water treatment.

    PubMed

    Lee, Young-Chul; Park, Won-Kun; Yang, Ji-Won

    2011-06-15

    We describe a facile and simple one-pot synthesis of water-soluble amino-organoclay under ambient conditions. The clay was used to successfully remove environmentally toxic anionic metals, such as arsenate, chromate, and ferricyanide. The electrostatic interactions between the anionic metals and the protonated amino (ammonium) groups of the amino-organoclay resulted in rapid precipitation, within 3 min, with a high removal capacity. The maximum removal capacities (in units of mg metal per g organoclay) of the amino-organoclay clay toward HAsO(4)(2-), CrO(4)(2-), or Fe(CN)(6)(3-) were, 30.73 mg/g, 34.67 mg/g, or 218.88 mg/g in case of 0.02 g, 0.03 g, and 0.005 g of the amino-organoclay, respectively. The removal efficiencies of 0.07 g, 0.09 g, and 0.03 g of the amino-organoclay whose dosage of clay was at the highest removal efficiency (%) for arsenate, chromate, and ferricyanide, respectively, presented 59.79%, 89.54%, and 97.43%. Furthermore, humic acid that ubiquitous in the organic matter present in water or soil environments, inhibited the removal rate of anionic metals, and thus the removal efficiencies toward all anionic metals were markedly reduced. Humic acid preferentially precipitated with the interaction of amino-organoclay prior to the anionic metals. PMID:21514042

  20. Metal Ion Removal from Wastewaters by Sorption on Activated Carbon, Cement Kiln Dust, and Sawdust.

    PubMed

    Shaheen, Sabry M; Eissa, Fawzy I; Ghanem, Khaled M; El-Din, Hala M Gamal; Al Anany, Fathia S

    2015-06-01

    This study assessed the efficiency of activated carbon, cement kiln dust (CKD), and sawdust for the removal of cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) from aqueous solutions under mono-metal and competitive sorption systems and the removal of Cd, Cu, and Zn from different industrial wastewaters. Batch equilibrium experiments were conducted in a mono-metal and competitive sorption system. The efficiency of the sorbents in the removal of Cd, Cu, and Zn from industrial wastewaters was also investigated. Cement kiln dust expressed the highest affinity for the metals followed by activated carbon and sawdust. Competition among the metals changed their distribution coefficient (Kd) with the sorbents. Sorption of Pb and Cu was higher than Cd and Zn. The average metal removal from the wastewaters varied from 74, 61, and 60% for Cd, Cu, and Zn, respectively, to nearly 100%. The efficiencies of CKD and activated carbon in removing metals were higher than sawdust, suggesting their potential as low-cost sorbents for the removal of toxic metals from wastewaters. PMID:26459819

  1. pH, dissolved oxygen, and adsorption effects on metal removal in anaerobic bioreactors.

    PubMed

    Willow, Mark A; Cohen, Ronald R H

    2003-01-01

    Anaerobic bioreactors were used to test the effect of the pH of influent on the removal efficiency of heavy metals from acid-rock drainage. Two studies used a near-neutral-pH, metal-laden influent to examine the heavy metal removal efficiency and hydraulic residence time requirements of the reactors. Another study used the more typical low-pH mine drainage influent. Experiments also were done to (i) test the effects of oxygen content of feed water on metal removal and (ii) the adsorptive capacity of the reactor organic substrate. Analysis of the results indicates that bacterial sulfate reduction may be a zero-order kinetic reaction relative to sulfate concentrations used in the experiments, and may be the factor that controls the metal mass removal efficiency in the anaerobic treatment systems. The sorptive capacities of the organic substrate used in the experiments had not been exhausted during the experiments as indicated by the loading rates of removal of metals exceeding the mass production rates of sulfide. Microbial sulfate reduction was less in the reactors receiving low-pH influent during experiments with short residence times. Sulfate-reducing bacteria may have been inhibited by high flows of low-pH water. Dissolved oxygen content of the feed waters had little effect on sulfate reduction and metal removal capacity. PMID:12931874

  2. REMOVAL OF CERTAIN FISSION PRODUCT METALS FROM LIQUID BISMUTH COMPOSITIONS

    DOEpatents

    Dwyer, O.E.; Howe, H.E.; Avrutik, E.R.

    1959-11-24

    A method is described for purifying a solution of urarium in liquid bismuth containing at least one metal from the group consisting of selenium, tellurium, palladium, ruthenium, rhodium, niobium, and zirconium. The solution is contacted with zinc in an inert atmosphere to form a homogeneous melt, a solid zinc phase is formed, and the zinc phase containing the metal is separated from the melt.

  3. A porous metal-organic framework with -COOH groups for highly efficient pollutant removal.

    PubMed

    Zhang, Qi; Yu, Jiancan; Cai, Jianfeng; Song, Ruijing; Cui, Yuanjing; Yang, Yu; Chen, Banglin; Qian, Guodong

    2014-11-28

    A new metal-organic framework with -COOH groups has been realized and demonstrates strong interactions with methylene blue and thus the complete removal of methylene blue from aqueous solution. PMID:25303384

  4. Novel Strategies for the Removal of Toxic Metals from Soils and Waters

    ERIC Educational Resources Information Center

    Roundhill, D. Max

    2004-01-01

    The elimination of poisonous metals possessing chemical or radioactive substances, from soils and waters, and chemistry's contribution towards efficacious and environmentally suitable removal methods are discussed. Various original tactics are studied and compared.

  5. Simultaneous removal of heavy metals from aqueous solution by natural limestones

    NASA Astrophysics Data System (ADS)

    Sdiri, Ali; Higashi, Teruo

    2013-03-01

    Two natural limestone samples, collected from the Campanian-Maastrichtian limestones, Tunisia, were used as adsorbents for the removal of toxic metals in aqueous systems. The results indicated that high removal efficiency could be achieved by the present natural limestones. Among the metal ions studied, Pb2+ was the most preferably removed cation because of its high affinity to calcite surface. In binary system, the presence of Cu2+ effectively depressed the sorption of Cd2+ and Zn2+. Similarly Cu2+ strongly competed with Pb2+ to limestone surface. In ternary system, the removal further decreased, but considerable amount of Pb2+ and Cu2+ still occurred regardless of the limestone sample. The same behavior was observed in quadruple system, where the selectivity sequence was Pb2+ > Cu2+ > Cd2+ > Zn2+. From these results, it was concluded that the studied limestones have the required technical specifications to be used for the removal of toxic metals from wastewaters.

  6. Treatment of oil well "produced water" by waste stabilization ponds: removal of heavy metals.

    PubMed

    Shpiner, R; Vathi, S; Stuckey, D C

    2009-09-01

    Oil well produced water (PW) can serve as an alternative water resource for restricted halotolerant agricultural purposes if the main pollutants, hydrocarbons and heavy metals, can be removed to below the irrigation standards. In this work, the potential removal of cadmium(II), chromium(III) and nickel(II) from PW by chemical precipitation in biological treatment was evaluated. Precipitation as a sulphide salt was found to be a very effective mechanism, which together with biosorption, biological metal uptake, precipitation as hydroxides and carbonates could remove heavy metals down to below irrigation standards. The existence and capability of these various mechanisms was demonstrated in the performance of a continuous artificial pond followed by intermittent sand filter, achieving removals of around 95% for nickel(II) and even higher removal rates for cadmium(II), chromium(III) from artificial PW after the installation of an anaerobic stage. The treated effluent quality was higher than that required by current European standards. PMID:19580985

  7. Removal and recovery of heavy metals from wastewaters by supported liquid membranes.

    PubMed

    Yang, X J; Fane, A G; MacNaughton, S

    2001-01-01

    The removal and recovery of Cu, Cr and Zn from plating rinse wastewater using supported liquid membranes (SLM) are investigated. SLMs with specific organic extractants as the liquid membrane carriers in series are able to remove and concentrate heavy metals with very high purity, which is very promising for recycling of heavy metals in the electroplating industry. A technical comparison between the membrane process and the conventional chemical precipitation process was made. PMID:11380200

  8. Evaluation of Moringa oleifera Seed Lectin as a Metal Remover in Aqueous Solutions.

    PubMed

    Freitas, José H E S; de Santana, Keissy V; da Silva, Pollyanna M; de Moura, Maiara C; Coelho, Luana C B B; do Nascimento, Aline E; Paiva, Patrícia M G; Napoleao, Thiago H

    2016-01-01

    The efficacy of Moringa oleifera seed lectin (WSMoL) as a metal remover in water and the effects of metals on its hemagglutinating and antibacterial activities were determined. Aqueous metal solutions were incubated with WSMoL for 8 h at 4°C and the concentrations of metals were determined using atomic absorption spectroscopy. Hemagglutination and antibacterial assays were conducted with WSMoL and lectin exposed or not to the metals. The removal efficiency of WSMoL was 49.00%, 53.21%, 71.45%, 55.42%, 69.88%, 62.14%, and 49.36% for Cd+2, Pb+2, Cu+2, Zn+2, Mg+2, Mn+2, and Al+3, respectively. WSMoL showed bacteriostatic and bactericidal activities against Escherichia coli and Salmonella enterica serovar Enteritidis. However, hemagglutinating and antibacterial activities were impaired after exposure to metals. In conclusion, WSMoL efficiently removed metals present in water but the interaction with metals impaired lectin carbohydrate-binding ability and antibacterial activity. This should be considered when properties of WSMoL other than metal removal are desired. PMID:27184499

  9. Distribution and removal efficiency of heavy metals in two constructed wetlands treating landfill leachate.

    PubMed

    Wojciechowska, Ewa; Waara, Sylvia

    2011-01-01

    The results of heavy metals (Fe, Mn, Zn, Ni, Cu, Cr, Pb, Cd) removal and partitioning between aqueous and solid phases at two treatment wetlands (TWs) treating municipal landfill leachates are presented. One of the TWs is a surface flow facility consisting of 10 ponds. The other TW is a newly constructed pilot-scale facility consisting of three beds with alternately vertical and horizontal subsurface flow. The metals concentrations were analysed in leachate (both TWs) and bottom sediments (surface flow TW). Very high (90.9-99.9%) removal rates of metals were observed in a mature surface flow TW. The effectiveness of metals removal in a newly constructed pilot-scale sub-surface flow wetland were considerably lower (range 0-73%). This is attributed to young age of the TW, different hydraulic conditions (sub-surface flow system with much shorter retention time, unoxic conditions) and presence of metallic complexes with refractory organic matter. PMID:22335101

  10. Heavy metal removal from sewage sludge ash by thermochemical treatment with gaseous hydrochloric acid.

    PubMed

    Vogel, Christian; Adam, Christian

    2011-09-01

    Sewage sludge ash (SSA) is a suitable raw material for fertilizers due to its high phosphorus (P) content. However, heavy metals must be removed before agricultural application and P should be transferred into a bioavailable form. The utilization of gaseous hydrochloric acid for thermochemical heavy metal removal from SSA at approximately 1000 °C was investigated and compared to the utilization of alkaline earth metal chlorides. The heavy metal removal efficiency increased as expected with higher gas concentration, longer retention time and higher temperature. Equivalent heavy metal removal efficiency were achieved with these different Cl-donors under comparable conditions (150 g Cl/kg SSA, 1000 °C). In contrast, the bioavailability of the P-bearing compounds present in the SSA after thermal treatment with gaseous HCl was not as good as the bioavailability of the P-bearing compounds formed by the utilization of magnesium chloride. This disadvantage was overcome by mixing MgCO(3) as an Mg-donor to the SSA before thermochemical treatment with the gaseous Cl-donor. A test series under systematic variation of the operational parameters showed that copper removal is more depending on the retention time than the removal of zinc. Zn-removal was declined by a decreasing ratio of the partial pressures of ZnCl(2) and water. PMID:21819089

  11. Effects of activated carbon fibre-supported metal oxide characteristics on toluene removal.

    PubMed

    Liu, Zhen-Shu; Peng, Yu-Hui; Li, Wen-Kai

    2014-01-01

    Few studies have investigated the use of activated carbon fibres (ACFs) impregnated with metal oxides for the catalytic oxidation of volatile organic compounds (VOCs). Thus, the effects of the ACF-supported metal oxides on toluene removal are determined in this study. Three catalysts, namely, Ce, Mn, and Cu, two pretreatment solutions NaOH and H2O2, and three reaction temperatures of 250 degrees C, 300 degrees C, and 350 degrees C, were employed to determine toluene removal. The composition and morphology of the catalysts were analysed using Brunauer-Emmett-Teller (BET), transmission electron microscope (TEM), inductively coupled plasma (ICP), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectrometer (FTIR), and thermo-gravimetric analyser (TGA) to study the effects of the catalyst's characteristics on toluene removal. The results demonstrated that the metal catalysts supported on the ACFs could significantly increase toluene removal. The Mn/ACFs and Cu/ACFs were observed to be most active in toluene removal at a reaction temperature of 250 degrees C with 10% oxygen content. Moreover, the data also indicated that toluene removal was slightly improved after pretreating the ACFs with NaOH and H2O2. The results suggested that surface-metal loading and the surface characteristics of the ACFs were the determinant parameters for toluene removal. Furthermore, the removal of toluene over Mn/ACFs-H202 decreased when the reaction temperature considered was > 300 degrees C. PMID:24701949

  12. Enhanced removal of heavy metals in primary treatment using coagulation and flocculation.

    PubMed

    Johnson, Pauline D; Girinathannair, Padmanabhan; Ohlinger, Kurt N; Ritchie, Stephen; Teuber, Leah; Kirby, Jason

    2008-05-01

    The goal of this study was to determine the removal efficiencies of chromium, copper, lead, nickel, and zinc from raw wastewater by chemically enhanced primary treatment (CEPT) and to attain a total suspended solids removal goal of 80%. Operating parameters and chemical doses were optimized by bench-scale tests. Locally obtained raw wastewater samples were spiked with heavy metal solutions to obtain representative concentrations of metals in wastewater. Jar tests were conducted to compare the metals removal efficiencies of the chemical treatment options using ferric chloride, alum, and anionic polymer. The results obtained were compared with those from other studies. It was concluded that CEPT using ferric chloride and anionic polymer is more effective than CEPT using alum for metals removal. The CEPT dosing of 40 mg/L ferric chloride and 0.5 mg/L polymer enhanced heavy metals removal efficiencies by over 200% for chromium, copper, zinc, and nickel and 475% for lead, compared with traditional primary treatment. Efficient metals capture during CEPT can result in increased allowable headworks loadings or lower metal levels in the outfall. PMID:18605386

  13. Removal and recovery of heavy metals from incinerator ash residues

    SciTech Connect

    Forrester, K.E.

    1997-12-01

    This paper presents results of a novel and state-of-the-art patent-pending processes developed jointly by Forrester Environmental Services Inc. (FESI) and Brookhaven National Laboratories (BNL) for the extraction and recovery of lead (Pb), Cadmium (Cd), Copper (Cu), Zinc (Zn) and other heavy metals from heavy metal bearing wastes including but not limited to solid waste incinerator bottom ash, flyash and combined ash. The heavy metal extraction and recovery processes were found to be capable of high percentage of heavy metals extraction and recovery at a relatively low cost under bench scale and full-scale refuse incinerator facility conditions. This paper presents empirical data from bench scale studies only, as the full-scale data is currently under review. The ash product remaining after extraction passed all TCLP regulatory limits and retained only minimal Pb, Cd, Cu, and Zn content and other water insoluble heavy metal compounds. Results of heavy metals recovery and low cost from ongoing field applications of this technology are consistent with the bench scale data presented within this paper.

  14. Mechanisms of heavy metal removal using microorganisms as biosorbent.

    PubMed

    Javanbakht, Vahid; Alavi, Seyed Amir; Zilouei, Hamid

    2014-01-01

    Release and distribution of heavy metals through industrial wastewaters has adverse affects on the environment via contamination of surface- and ground-water resources. Biosorption of heavy metals from aqueous solutions has been proved to be very promising, offering significant advantages such as low cost, availability, profitability, ease of operation, and high efficiency, especially when dealing with low concentrations. Residual biomasses of industrial microorganisms including bacteria, algae, fungi, and yeast have been found to be capable of efficiently accumulating heavy metals as biosorbent. This paper presents and investigates major mechanisms of biosorption and most of the functional groups involved. The biosorption process includes the following mechanisms: transport across cell membrane, complexation, ion exchange, precipitation, and physical adsorption. In order to understand how metals bind to the biomass, it is essential to identify the functional groups responsible for metal binding. Most of these groups have been characterized on the cell walls. The biosorbent contains a variety of functional sites including carboxyl, imidazole, sulfydryl, amino, phosphate, sulfate, thioether, phenol, carbonyl, amide, and hydroxyl moieties that are responsible for metal adsorption. These could be helpful to improve biosorbents through modification of surface reactive sites via surface grafting and/or exchange of functional groups. PMID:24804650

  15. The removal of precious metals by conductive polymer filtration

    SciTech Connect

    Cournoyer, M.E.

    1996-10-01

    The growing demand for platinum-group metals (PGM) within the DOE complex and in industry, the need for modern and clean processes, and the increasing volume of low-grade material for secondary PGM recovery has a direct impact on the industrial practice of recovering and refining precious metals. There is a tremendous need for advanced metal ion recovery and waste minimization techniques, since the currently used method of precipitation-dissolution is inadequate. Los Alamos has an integrated program in ligand-design and separations chemistry which has developed and evaluated a series of water- soluble metal-binding polymers for recovering actinides and toxic metals from variety of process streams. A natural extension of this work is to fabricate these metal-selective polymers into membrane based separation unites, i.e., hollow-fiber membranes. In the present investigation, the material for a novel hollow-fiber membrane is characterized and its selectivity for PGM reported. Energy and waste savings and economic competitiveness are also described.

  16. Removal and selective recovery of heavy-metal ions from industrial waste waters. Technical completion report

    SciTech Connect

    Darnall, D.W.; Gardea-Torresdey, J.

    1989-02-01

    Accumulation of toxic metal ions in water supplies is a matter of increasingly grave concern. Primarily the undesirable by-products of mining and industrial activity, these ions can cause acute and chronic illnesses in humans and other animals. In an effort to limit further contamination, development of efficient, widely applicable, low-cost methods for removal of heavy-metal ions from waters deserves high priority. One new method that has allowed both the removal and recovery of metal ions from water has been the utilization of microorganisms such as algae. This metal-ion sorption process is based upon the natural, very strong affinity of the cell walls of algae for heavy metal ions. There appear to be distinct advantages of the immobilized algal system over other technology currently used for heavy-metal-ion cleanup from waste waters. The goals of the project were (1) to examine the effects of calcium(II) and magnesium(II) on transition metal binding to the algae, (2) to test the immobilized silica-algal polymers for removal of metal ions from electroplating plant waste waters, (3) to evaluate the effects of culturing conditions on the metal binding capacity of the resulting biomass, and (4) to investigate the mechanism of metal-ion binding to different algae.

  17. Removal of technetium, carbon tetrachloride, and metals from DOE properties. 1998 annual progress report

    SciTech Connect

    Mallouk, T.E.; Darab, J.G.; Ponder, S.M.

    1998-06-01

    'The objective of the project is to develop and characterize supported reducing agents, and solid waste forms derived from them, which will be effective in the removal of transition metal ions, chlorinated organic molecules, and technetium from aqueous mixed wastes. This work follows the discovery that a nanoscale form of zero-valent iron, dispersed on high surface area supports, reduces metal ions (chromium, mercury, and lead) and rhenium (as a surrogate for technetium) to insoluble forms much faster than does unsupported iron. The scientific goals of the project are to better understand the mechanism of the reduction process, to develop supports that are compatible with a variety of mixed waste compositions, and to develop surface modifiers for the supported iron aggregates that will optimize their selectivity for the contaminants of interest. The support composition is of particular interest in the case of technetium (Tc) separation and stabilization in the Hanford tank wastes. While it is expected that pertechnetate will be reduced insoluble TcO{sub 2} , the support material must be compatible with the vitrification process used in the final waste disposition. The surface modifications are also a focal point for Hanford applications because of the complex and variable makeup of the tank wastes. This report summarizes progress in the first 8 months of a 3-year collaborative project involving Penn State and Pacific Northwest National Laboratory (PNNL).'

  18. Multivariate methods for evaluating the efficiency of electrodialytic removal of heavy metals from polluted harbour sediments.

    PubMed

    Pedersen, Kristine Bondo; Kirkelund, Gunvor M; Ottosen, Lisbeth M; Jensen, Pernille E; Lejon, Tore

    2015-01-01

    Chemometrics was used to develop a multivariate model based on 46 previously reported electrodialytic remediation experiments (EDR) of five different harbour sediments. The model predicted final concentrations of Cd, Cu, Pb and Zn as a function of current density, remediation time, stirring rate, dry/wet sediment, cell set-up as well as sediment properties. Evaluation of the model showed that remediation time and current density had the highest comparative influence on the clean-up levels. Individual models for each heavy metal showed variance in the variable importance, indicating that the targeted heavy metals were bound to different sediment fractions. Based on the results, a PLS model was used to design five new EDR experiments of a sixth sediment to achieve specified clean-up levels of Cu and Pb. The removal efficiencies were up to 82% for Cu and 87% for Pb and the targeted clean-up levels were met in four out of five experiments. The clean-up levels were better than predicted by the model, which could hence be used for predicting an approximate remediation strategy; the modelling power will however improve with more data included. PMID:25464314

  19. ENGINEERING ASSESSMENT OF HOT-ACID TREATMENT OF MUNICIPAL SLUDGE FOR HEAVY METALS REMOVAL

    EPA Science Inventory

    The hot-acid method for treating sludge was developed by the Walden Division of Abcor, Inc., to remove heavy metals from municipal wastewater sludge. Investigations by Walden have demonstrated the degrees to which heavy metals are solubilized. Sulfuric acid dosage at about 20 to ...

  20. REMOVAL OF HEAVY METALS FROM INDUSTRIAL WASTEWATERS USING INSOLUBLE STARCH XANTHATE

    EPA Science Inventory

    The Northern Regional Research Center developed an effective process to remove heavy metals from wastewaters of two nonferrous metal industries and insoluble starch xanthate (ISX). The study included bench-scale evaluation of wastewaters from two lead battery and one brass mill w...

  1. Lithium-metal infused trenches (LiMIT) for heat removal in fusion devices

    NASA Astrophysics Data System (ADS)

    Ruzic, D. N.; Xu, W.; Andruczyk, D.; Jaworski, M. A.

    2011-10-01

    Observation of liquid lithium flow in metal trenches has been made using a lithium-metal infused trench (LiMIT) tile and is reported here. The flow is self-pumping and uses thermoelectric magnetohydrodynamics to remove heated lithium and replenish it at a lower temperature. Flow velocities have been measured and compared with theoretical predictions.

  2. Pentek metal coating removal system: Baseline report; Greenbook (chapter)

    SciTech Connect

    1997-07-31

    The Pentek coating removal technology was tested and is being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The Pentek coating removal system consisted of the ROTO-PEEN Scaler, CORNER-CUTTER{reg_sign}, and VAC-PAC{reg_sign}. They are designed to remove coatings from steel, concrete, brick, and wood. The Scaler uses 3M Roto Peen tungsten carbide cutters while the CORNER-CUTTER{reg_sign} uses solid needles for descaling activities. These hand tools are used with the VAC-PAC{reg_sign} vacuum system to capture dust and debris as removal of the coating takes place. The safety and health evaluation during the testing demonstration focused on two main areas of exposure: dust and noise. Dust exposure minimal, but noise exposure was significant. Further testing for each exposure is recommended because of the environment where the testing demonstration took place. It is feasible that the dust and noise levels will be higher in an enclosed operating environment of different construction. In addition, other areas of concern found were arm-hand vibration, whole-body, ergonomics, heat stress, tripping hazards, electrical hazards, machine guarding, and lockout/tagout.

  3. Method of removing bulk sodium from metallic surfaces

    DOEpatents

    Maffei, H.P.; Borisch, R.R.

    1975-11-11

    A process of removing sodium from an article, particularly one made of stainless steel, by treating it with a mixture of water vapor and a gas which is inert to sodium is described. By selecting combinations of temperature and water vapor-to-gas ratio, the reaction temperature is controlled to prevent damage to the articles.

  4. A new method for the removal of toxic metal ions from acid-sensitive biomaterial

    SciTech Connect

    Seki, Hideshi; Suzuki, Akira

    1997-06-01

    A new method (competitive adsorption method) for the removal of toxic heavy metals from acid-sensitive biomaterials was proposed and it was applied to the removal of cadmium from the midgut gland (MG) of scallop, Patinopecten yessoensis. Insolubilized humic acid, which has been developed in the laboratory, was used as a competitive adsorbent. A metal-complexation model was used to determine the adsorption characteristics of cadmium onto MG. Furthermore, the model was applied to the competitive adsorption system. The results showed that the competitive adsorption method enabled the simultaneous removal of toxic cadmium from both liquid and MG phase under mild acidic condition (pH 5).

  5. Literature review on the use of bioaccumulation for heavy metal removal and recovery

    SciTech Connect

    Benemann, J.R. , Pinole, CA ); Wilde, E.W. )

    1991-02-01

    Bioaccumulation of metals by microbes -- bioremoval'' -- is a powerful new technology for the concentration, recovery, and removal of toxic heavy metals and radionuclides from waste streams and contaminated environments. Algae are particularly well suited for metal bioremoval. A recent commercial application of bioremoval utilizes inert (dead) immobilized microalgae biomass as ion exchange materials for the removal of heavy metals from industrial waste waters. Also, living microalgal cultures have been used to remove metals from mine effluents. Microbial cells and biomass can bioaccumulate metals and radionuclides by a large variety of mechanisms, both dependent and independent of cell metabolism. Microbial cell walls can act as ion exchange and metal complexation agents. Heavy metals can precipitate and even crystallize on cell surfaces. Metabolically produced hydrogen sulfide or other metabolic products can bioprecipitate heavy metals. Many microbes produce both intra- and extracellular metal complexing agents which could be considered in practical metal removal processes. Bioremoval processes are greatly affected by the microbial species and even strain used, pH, redox potential, temperature, and other conditions under which the microbes are grown. Development of practical applications of bioremoval requires applies research using the particular waste solutions to be treated, or close simulations thereof. From a practical perspective, the selection of the microbial biomass and the process for contacting the microbial biomass with the metal containing solutions are the key issues. Much of the recent commercial R D has emphasized commercially available, inert, microbial biomass sources as these can be acquired in sufficient quantities at affordable costs. The fundamental research and practical applications of bioaccumulation by microalgae suggests these organisms warrant a high priority in the development of advanced bioremoval processes.

  6. Literature review on the use of bioaccumulation for heavy metal removal and recovery. Volume 2

    SciTech Connect

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

    1991-02-01

    Bioaccumulation of metals by microbes -- `` bioremoval`` -- is a powerful new technology for the concentration, recovery, and removal of toxic heavy metals and radionuclides from waste streams and contaminated environments. Algae are particularly well suited for metal bioremoval. A recent commercial application of bioremoval utilizes inert (dead) immobilized microalgae biomass as ion exchange materials for the removal of heavy metals from industrial waste waters. Also, living microalgal cultures have been used to remove metals from mine effluents. Microbial cells and biomass can bioaccumulate metals and radionuclides by a large variety of mechanisms, both dependent and independent of cell metabolism. Microbial cell walls can act as ion exchange and metal complexation agents. Heavy metals can precipitate and even crystallize on cell surfaces. Metabolically produced hydrogen sulfide or other metabolic products can bioprecipitate heavy metals. Many microbes produce both intra- and extracellular metal complexing agents which could be considered in practical metal removal processes. Bioremoval processes are greatly affected by the microbial species and even strain used, pH, redox potential, temperature, and other conditions under which the microbes are grown. Development of practical applications of bioremoval requires applies research using the particular waste solutions to be treated, or close simulations thereof. From a practical perspective, the selection of the microbial biomass and the process for contacting the microbial biomass with the metal containing solutions are the key issues. Much of the recent commercial R&D has emphasized commercially available, inert, microbial biomass sources as these can be acquired in sufficient quantities at affordable costs. The fundamental research and practical applications of bioaccumulation by microalgae suggests these organisms warrant a high priority in the development of advanced bioremoval processes.

  7. Immobilization of Thiadiazole Derivatives on Magnetite Mesoporous Silica Shell Nanoparticles in Application to Heavy Metal Removal from Biological Samples

    SciTech Connect

    Emadi, Masoomeh; Shams, Esmaeil

    2010-12-02

    In this report magnetite was synthesized by a coprecipitation method, then coated with a layer of silica. Another layer of mesoporous silica was added by a sol-gel method, then 5-amino-1,3,4-thiadiazole-thiol (ATT) was immobilized onto the synthesized nanoparticles with a simple procedure. This was followed by a series of characterizations, including transmission electron microscopy (TEM), FT-IR spectrum, elemental analysis and XRD. Heavy metal uptake of the modified nanoparticles was examined by atomic absorption spectroscopy. For further investigation we chose Cu{sup 2+} as the preferred heavy metal to evaluate the amount of adsorption, as well as the kinetics and mechanism of adsorption. Finally, the capacity of our nanoparticles for the heavy metal removal from blood was shown. We found that the kinetic rate of Cu{sup 2+} adsorption was 0.05 g/mg/min, and the best binding model was the Freundlich isotherm.

  8. REMOVAL OF HEAVY METALS BY BIOPOLYMERS. (R825549C018)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  9. Effective removal of heavy metal by biochar colloids under different pyrolysis temperatures.

    PubMed

    Qian, Linbo; Zhang, Wenying; Yan, Jingchun; Han, Lu; Gao, Weiguo; Liu, Rongqin; Chen, Mengfang

    2016-04-01

    Biochar colloids' association with heavy metal needs be studied to precisely evaluate the effectiveness of biochar as sorbents. The structure of biochar colloids and their roles in heavy metal removal were investigated by Fourier-Transform Infrared Spectroscopy, X-ray Diffraction and batch adsorption experiments, respectively. Due to the numerous oxygen function groups and mineral matters contained in biochar colloids, the removal capacity of chromium (Cr) and cadmium (Cd) to biochar colloids was much greater than that of biochar residues. The highest adsorption capacities of Cr(III) and Cd(II) under initial pH 3.5 were obtained by RS400, which were mainly attributed to the presence of oxygen function groups and mineral matters simultaneously. The highest removal capacity of Cr(VI) was observed by RS300 due to the additional reduction by phenolic functional groups of RS300C. Therefore, the functions of biochar colloids for heavy metal removal should be considered. PMID:26859330

  10. Removal of textile dyes and metallic ions using polyelectrolytes and macroelectrolytes containing sulfonic acid groups.

    PubMed

    Caldera Villalobos, M; Peláez Cid, A A; Herrera González, Ana M

    2016-07-15

    This work reports the removal of textile dyes and metallic ions by means of adsorption and coagulation-flocculation using two polyelectrolytes and two macroelectrolytes containing sulfonic acid groups. The adsorption of textile dyes was studied in aqueous solutions containing cationic dyes and in wastewater containing a vat dye. Also, removal of vat and naphthol dyes was studied using the process of coagulation-flocculation. The results show these materials possess elevated adsorption capacity, and they accomplished removal rates above 97% in aqueous solutions. The removal of the vat dye improved the quality of the wastewater notably, and an uncolored effluent was obtained at the end of the treatment. The treatment using adsorption decreased the values for coloration, conductivity, suspended solids, and pH. The removal of vat and naphthol dyes by means of coagulation-flocculation was studied as well, and removal rates of 90% were obtained. The polyelectrolytes and macroelectrolytes also proved effective in the adsorption of metallic ions in wastewater. The treatment using adsorption accomplished high removal rates of metallic ions, and it showed greater selectivity towards Cu(2+), Fe(3+) and Pb(2+). A decrease in the content of solids as well as the values for COD and conductivity was observed in the wastewater as well. The analyses of FT-IR indicated that cationic dyes and metallic ions were chemisorbed by means of ionic exchange. PMID:27082258

  11. Heavy metal removal from MSS fly ash by thermal and chlorination treatments.

    PubMed

    Liu, Jingyong; Chen, Jiacong; Huang, Limao

    2015-01-01

    The thermal behavior of heavy metals in the co-incineration of municipal solid waste-sludge incinerator fly ash (MSS fly ash) was studied using a laboratory-scale tube furnace. The results indicate that without the addition of chlorinating agents, temperature was an important parameter and had significantly influenced on heavy metal removal, whereas the residence time had a weak effect. Between 900 and 1000 °C for 60 to 300 min, heavy metals reacted with chloride-inherent in the fly ash, and approximately 80 to 89% of Pb, 48% to 56% of Cd, 27% to 36% of Zn and 6% to 24% of Cu were removed. After the adding chlorinating agents, the evaporation rate of the heavy metals improved dramatically, where the evaporation rates of Cu and Zn were larger than that of Pb and Cd. As the amount of added chlorinating agents increased, the removal rate of heavy metals increased. However, the effect of the type of chlorinating agent on the chlorination of heavy metals differed considerably, where NaCl had the weakest effect on the removal rate of Cu, Cd and Zn. In terms of resource recovery and decontamination, MgCl2 and CaCl2 are the best choices due to their efficient removal of Zn. PMID:26602592

  12. Immobilized materials for removal of toxic metal ions from surface/groundwaters and aqueous waste streams.

    PubMed

    Zawierucha, Iwona; Kozlowski, Cezary; Malina, Grzegorz

    2016-04-20

    Heavy metals from industrial processes are of special concern because they produce chronic poisoning in the aquatic environment. More strict environmental regulations on the discharge of toxic metals require the development of various technologies for their removal from polluted streams (i.e. industrial wastewater, mine waters, landfill leachate, and groundwater). The separation of toxic metal ions using immobilized materials (novel sorbents and membranes with doped ligands), due to their high selectivity and removal efficiency, increased stability, and low energy requirements, is promising for improving the environmental quality. This critical review is aimed at studying immobilized materials as potential remediation agents for the elimination of numerous toxic metal (e.g. Pb, Cd, Hg, and As) ions from polluted streams. This study covers the general characteristics of immobilized materials and separation processes, understanding of the metal ion removal mechanisms, a review of the application of immobilized materials for the removal of toxic metal ions, as well as the impacts of various parameters on the removal efficiency. In addition, emerging trends and opportunities in the field of remediation technologies using these materials are addressed. PMID:27044908

  13. Heavy metal removal from MSS fly ash by thermal and chlorination treatments

    PubMed Central

    Liu, Jingyong; Chen, Jiacong; Huang, Limao

    2015-01-01

    The thermal behavior of heavy metals in the co-incineration of municipal solid waste-sludge incinerator fly ash (MSS fly ash) was studied using a laboratory-scale tube furnace. The results indicate that without the addition of chlorinating agents, temperature was an important parameter and had significantly influenced on heavy metal removal, whereas the residence time had a weak effect. Between 900 and 1000 °C for 60 to 300 min, heavy metals reacted with chloride-inherent in the fly ash, and approximately 80 to 89% of Pb, 48% to 56% of Cd, 27% to 36% of Zn and 6% to 24% of Cu were removed. After the adding chlorinating agents, the evaporation rate of the heavy metals improved dramatically, where the evaporation rates of Cu and Zn were larger than that of Pb and Cd. As the amount of added chlorinating agents increased, the removal rate of heavy metals increased. However, the effect of the type of chlorinating agent on the chlorination of heavy metals differed considerably, where NaCl had the weakest effect on the removal rate of Cu, Cd and Zn. In terms of resource recovery and decontamination, MgCl2 and CaCl2 are the best choices due to their efficient removal of Zn. PMID:26602592

  14. Heavy metal removal from MSS fly ash by thermal and chlorination treatments

    NASA Astrophysics Data System (ADS)

    Liu, Jingyong; Chen, Jiacong; Huang, Limao

    2015-11-01

    The thermal behavior of heavy metals in the co-incineration of municipal solid waste-sludge incinerator fly ash (MSS fly ash) was studied using a laboratory-scale tube furnace. The results indicate that without the addition of chlorinating agents, temperature was an important parameter and had significantly influenced on heavy metal removal, whereas the residence time had a weak effect. Between 900 and 1000 °C for 60 to 300 min, heavy metals reacted with chloride-inherent in the fly ash, and approximately 80 to 89% of Pb, 48% to 56% of Cd, 27% to 36% of Zn and 6% to 24% of Cu were removed. After the adding chlorinating agents, the evaporation rate of the heavy metals improved dramatically, where the evaporation rates of Cu and Zn were larger than that of Pb and Cd. As the amount of added chlorinating agents increased, the removal rate of heavy metals increased. However, the effect of the type of chlorinating agent on the chlorination of heavy metals differed considerably, where NaCl had the weakest effect on the removal rate of Cu, Cd and Zn. In terms of resource recovery and decontamination, MgCl2 and CaCl2 are the best choices due to their efficient removal of Zn.

  15. Soil amendments for heavy metals removal from stormwater runoff discharging to environmentally sensitive areas

    NASA Astrophysics Data System (ADS)

    Trenouth, William R.; Gharabaghi, Bahram

    2015-10-01

    Concentrations of dissolved metals in stormwater runoff from urbanized watersheds are much higher than established guidelines for the protection of aquatic life. Five potential soil amendment materials derived from affordable, abundant sources have been tested as filter media using shaker tests and were found to remove dissolved metals in stormwater runoff. Blast furnace (BF) slag and basic oxygenated furnace (BOF) slag from a steel mill, a drinking water treatment residual (DWTR) from a surface water treatment plant, goethite-rich overburden (IRON) from a coal mine, and woodchips (WC) were tested. The IRON and BOF amendments were shown to remove 46-98% of dissolved metals (Cr, Co, Cu, Pb, Ni, Zn) in repacked soil columns. Freundlich adsorption isotherm constants for six metals across five materials were calculated. Breakthrough curves of dissolved metals and total metal accumulation within the filter media were measured in column tests using synthetic runoff. A reduction in system performance over time occurred due to progressive saturation of the treatment media. Despite this, the top 7 cm of each filter media removed up to 72% of the dissolved metals. A calibrated HYDRUS-1D model was used to simulate long-term metal accumulation in the filter media, and model results suggest that for these metals a BOF filter media thickness as low as 15 cm can be used to improve stormwater quality to meet standards for up to twenty years. The treatment media evaluated in this research can be used to improve urban stormwater runoff discharging to environmentally sensitive areas (ESAs).

  16. 42 CFR 493.575 - Removal of deeming authority or CLIA exemption and final determination review.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Removal of deeming authority or CLIA exemption and final determination review. 493.575 Section 493.575 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY REQUIREMENTS Accreditation by a Private,...

  17. Metal removal and sulfate reduction in low-sulfate mine drainage

    SciTech Connect

    Farmer, G.H.; Updegraff, D.M.; Radehaus, P.M.; Bates, E.R.

    1995-12-31

    A treatability study using two continuous upflow bioreactors was conducted to evaluate the potential removal of metal contamination, primarily zinc, from mine drainage with constructed wetlands that incorporate sulfate-reducing bacteria (SRB). The drainage from the Burleigh Tunnel in Silver Plume, Colorado, contains low levels of sulfate that may limit the production of hydrogen sulfide by sulfate-reducing bacteria, thus limiting metal removal by the system. Total metals, anions, and field parameters in the mine drainage and the bioreactor effluents were routinely analyzed over 8 weeks. In addition, the bioreactor compost packing was analyzed for metals and sulfate-reducing bacteria. Zinc removal in both reactors was in excess of 99% after 8 weeks of operation. Furthermore, sulfate-reducing bacteria in the bioreactor compost ranged from 10{sup 5} to 10{sup 6} colony-forming units per gram of compost.

  18. Using biopolymers to remove heavy metals from soil and water

    SciTech Connect

    Krishnamurthy, S.; Frederick, R.M.

    1993-11-19

    Chemical remediation of soil may involve the use of harsh chemicals that generate waste streams, which may adversely affect the soil's integrity and ability to support vegetation. This article reviews the potential use of benign reagents, such as biopolymers, to extract heavy metals. The biopolymers discussed are chitin and chitosan, modified starch, cellulose, and polymer-containing algae. (Copyright (c) Remediation 1994.)

  19. USING BIOPOLYMERS TO REMOVE HEAVY METALS FROM SOIL AND WATER

    EPA Science Inventory

    Chemical remediation of soils may involve the use of harsh chemicals that generate waste streams and may adversely affect the soil's integrity and ability to support vegetation. his paper reviews the promise of benign reagents such as biopolymers to extract metals. he biopolymers...

  20. Removal of 222Rn daughters from metal surfaces

    NASA Astrophysics Data System (ADS)

    Zuzel, G.; Wojcik, M.; Majorovits, B.; Lampert, M. O.; Wendling, P.

    2015-08-01

    Removal of the long-lived 222Rn daughters (210Pb, 210Bi and 210Po) from copper, stainless steel and germanium surfaces was investigated. As cleaning techniques etching and electro-polishing was applied to samples in a form of discs exposed earlier to a strong radon source. Reduction of the 210Pb activity was tested using a HPGe spectrometer, for 210Bi a beta spectrometer and for 210Po an alpha spectrometer was used. According to the conducted measurements electro-polishing was always more efficient compared to etching and in case of copper the activity reduction factors for 210Pb, 210Bi and 210Po were between 200 and 400. Etching does not remove 210Po from copper but works very efficiently from germanium. Results obtained for 210Pb and 210Bi for etched stainless steel were worse but still slightly better than those achieved for copper.

  1. Removal of {sup 222}Rn daughters from metal surfaces

    SciTech Connect

    Zuzel, G.; Wojcik, M.; Majorovits, B.; Lampert, M. O.; Wendling, P.

    2015-08-17

    Removal of the long-lived {sup 222}Rn daughters ({sup 210}Pb, {sup 210}Bi and {sup 210}Po) from copper, stainless steel and germanium surfaces was investigated. As cleaning techniques etching and electro-polishing was applied to samples in a form of discs exposed earlier to a strong radon source. Reduction of the {sup 210}Pb activity was tested using a HPGe spectrometer, for {sup 210}Bi a beta spectrometer and for {sup 210}Po an alpha spectrometer was used. According to the conducted measurements electro-polishing was always more efficient compared to etching and in case of copper the activity reduction factors for {sup 210}Pb, {sup 210}Bi and {sup 210}Po were between 200 and 400. Etching does not remove {sup 210}Po from copper but works very efficiently from germanium. Results obtained for {sup 210}Pb and {sup 210}Bi for etched stainless steel were worse but still slightly better than those achieved for copper.

  2. Silver-modified clinoptilolite for the removal of Escherichia coli and heavy metals from aqueous solutions.

    PubMed

    Akhigbe, Lulu; Ouki, Sabeha; Saroj, Devendra; Lim, Xiang Min

    2014-09-01

    This paper investigates the potential of using the silver antibacterial properties combined with the metal ion exchange characteristics of silver-modified clinoptilolite to produce a treatment system capable of removing both contaminants from aqueous streams. The results have shown that silver-modified clinoptilolite is capable of completely eliminating Escherichia coli after 30-min contact time demonstrating its effectiveness as a disinfectant. Systems containing both E. coli and metals exhibited 100 % E. coli reduction after 15-min contact time and maximum metal adsorption removal efficiencies of 97, 98, and 99 % for Pb(2+), Cd(2+), and Zn(2+) respectively after 60 min; 0.182-0.266 mg/g of metal ions were adsorbed by the zeolites in the single- and mixed-metal-containing solutions. Nonmodified clinoptilolite showed no antibacterial properties. This study demonstrated that silver-modified clinoptilolite exhibited high disinfection and heavy metal removal efficiencies and consequently could provide an effective combined treatment system for the removal of E. coli and metals from contaminated water streams. PMID:24756684

  3. Removal of metals in leachate from sewage sludge using electrochemical technology.

    PubMed

    Meunier, N; Drogui, P; Gourvenec, C; Mercier, G; Hausler, R; Blais, J F

    2004-02-01

    Heavy metals in acidic leachates from sewage sludge are usually removed by chemical precipitation, which often requires high concentration of chemicals and induces high metallic sludge production. Electrochemical technique has been explored as an alternative method in a laboratory pilot scale reactor for heavy metals (Cu and Zn) removal from sludge leachate. Three electrolytic cell arrangements using different electrodes materials were tested: mild steel or aluminium bipolar electrode (EC cell), Graphite/stainless steel monopolar electrodes (ER cell) and iron-monopolar electrodes (EC-ER cell). Results showed that the best performances of metal removal were obtained with EC and EC-ER cells using mild steel electrodes operated respectively at current intensities of 0.8 and 2.0 A through 30 and 60 min of treatment. The yields of Cu and Zn removal from leachate varied respectively from 92.4 to 98.9% and from 69.8 to 76.6%. The amounts of 55 and 44 kg tds(-1) of metallic sludge were respectively produced using EC and EC-ER cells. EC and EC-ER systems involved respectively a total cost of 21.2 and 13.1 CAN dollars per ton of dry sludge treated including only energy consumption and metallic sludge disposal. The treatment using EC-ER system was found to be effective and more economical than the traditional metal precipitation using either Ca(OH)2 and/or NaOH. PMID:15116882

  4. Efficiency of SPIONs functionalized with polyethylene glycol bis(amine) for heavy metal removal

    NASA Astrophysics Data System (ADS)

    Wanna, Yongyuth; Chindaduang, Anon; Tumcharern, Gamolwan; Phromyothin, Darinee; Porntheerapat, Supanit; Nukeaw, Jiti; Hofmann, Heirich; Pratontep, Sirapat

    2016-09-01

    Hybrid magnetic nanoparticles based on poly(methylmethacrylate) (PMMA) and super-paramagnetic iron oxide nanopaticles (SPIONs) with selective surface modification has been developed for heavy metal removal by applying external magnetic fields. The nanoparticles were prepared by the emulsion polymerization technique in an aqueous suspension of SPIONs. The hydrolysis of carboxyl functional group was then applied for grafting polyethylene glycol bis(amine)(PEG-bis(amine)) onto the PMMA-coated SPIONs. The morphology, the chemical structure and the magnetic properties of the grafted nanoparticles were investigated. The efficiency of the hybrid nanoparticles for heavy metal removal were conducted on Pb(II), Hg(II), Cu(II) and Co(II) in aqueous solutions.The metal concentration in the solutions after separation by the hybrid nanoparticles was determined by inductively coupled plasma optical emission spectrometer (ICP-OES). The results show the heavy metal uptake ratios of 0.08, 0.04, 0.03, and 0.01 mM per gramme of the grafted SPIONs for Pb(II), Hg(II), Cu(II), and Co(II), respectively. A competitive removal of Cu(II), Pb(II), Co(II) and Hg(II) ions in mixed metal salt solutions has also been studied.The heavy metal removal efficiency of the hybrid nanoparitcles was found to depend on the cation radius, in accordance with capture of metal ions by the amine group.

  5. Removing heavy metals from synthetic effluents using "kamikaze" Saccharomyces cerevisiae cells.

    PubMed

    Ruta, Lavinia; Paraschivescu, Codruta; Matache, Mihaela; Avramescu, Sorin; Farcasanu, Ileana Cornelia

    2010-01-01

    One key step of the bioremediation processes designed to clean up heavy metal contaminated environments is growing resistant cells that accumulate the heavy metals to ensure better removal through a combination of biosorption and continuous metabolic uptake after physical adsorption. Saccharomyces cerevisiae cells can easily act as cation biosorbents, but isolation of mutants that are both hyperaccumulating and tolerant to heavy metals proved extremely difficult. Instead, mutants that are hypersensitive to heavy metals due to increased and continuous uptake from the environment were considered, aiming to use such mutants to reduce the heavy metal content of contaminated waters. In this study, the heavy metal hypersensitive yeast strain pmr1Delta was investigated for the ability to remove Mn2+, Cu2+, Co2+, or Cd2+ from synthetic effluents. Due to increased metal accumulation, the mutant strain was more efficient than the wild-type in removing Mn2+, Cu2+, or Co2+ from synthetic effluents containing 1-2 mM cations, with a selectivity and also in removing Mn2+ and Cd2+ from synthetic effluents containing 20-50 microM cations, with a selectivity Mn2+ > Cd2+. PMID:19795117

  6. Identification of Bacillus megaterium and Microbacterium liquefaciens genes involved in metal resistance and metal removal.

    PubMed

    Fierros-Romero, Grisel; Gómez-Ramírez, Marlenne; Arenas-Isaac, Ginesa E; Pless, Reynaldo C; Rojas-Avelizapa, Norma G

    2016-06-01

    Bacillus megaterium MNSH1-9K-1 and Microbacterium liquefaciens MNSH2-PHGII-2, 2 nickel- and vanadium-resistant bacteria from mine tailings located in Guanajuato, Mexico, are shown to have the ability to remove 33.1% and 17.8% of Ni, respectively, and 50.8% and 14.0% of V, respectively, from spent petrochemical catalysts containing 428 ± 30 mg·kg(-1) Ni and 2165 ± 77 mg·kg(-1) V. In these strains, several Ni resistance determinants were detected by conventional PCR. The nccA (nickel-cobalt-cadmium resistance) was found for the first time in B. megaterium. In M. liquefaciens, the above gene as well as the czcD gene (cobalt-zinc-cadmium resistance) and a high-affinity nickel transporter were detected for the first time. This study characterizes the resistance of M. liquefaciens and B. megaterium to Ni through the expression of genes conferring metal resistance. PMID:27210016

  7. Removal of heavy metals from kaolin using an upward electrokinetic soil remedial (UESR) technology.

    PubMed

    Wang, Jing-Yuan; Huang, Xiang-Jun; Kao, Jimmy C M; Stabnikova, Olena

    2006-08-25

    An upward electrokinetic soil remedial (UESR) technology was proposed to remove heavy metals from contaminated kaolin. Unlike conventional electrokinetic treatment that uses boreholes or trenches for horizontal migration of heavy metals, the UESR technology, applying vertical non-uniform electric fields, caused upward transportation of heavy metals to the top surface of the treated soil. The effects of current density, treatment duration, cell diameter, and different cathode chamber influent (distilled water or 0.01 M nitric acid) were studied. The removal efficiencies of heavy metals positively correlated to current density and treatment duration. Higher heavy metals removal efficiency was observed for the reactor cell with smaller diameter. A substantial amount of heavy metals was accumulated in the nearest to cathode 2 cm layer of kaolin when distilled water was continuously supplied to the cathode chamber. Heavy metals accumulated in this layer of kaolin can be easily excavated and disposed off. The main part of the removed heavy metals was dissolved in cathode chamber influent and moved away with cathode chamber effluent when 0.01 M nitric acid was used, instead of distilled water. Energy saving treatment by UESR technology with highest metal removal efficiencies was provided by two regimes: (1) by application of 0.01 M nitric acid as cathode chamber influent, cell diameter of 100 mm, duration of 18 days, and constant voltage of 3.5 V (19.7 k Wh/m(3) of kaolin) and (2) by application of 0.01 M nitric acid as cathode chamber influent, cell diameter of 100 cm, duration of 6 days, and constant current density of 0.191 mA/cm(2) (19.1 k Wh/m(3) of kaolin). PMID:16504386

  8. Method for removing metal vapor from gas streams

    DOEpatents

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

    1996-01-01

    A process for cleaning an inert gas contaminated with a metallic vapor, such as cadmium, involves withdrawing gas containing the metallic contaminant from a gas atmosphere of high purity argon; passing the gas containing the metallic contaminant to a mass transfer unit having a plurality of hot gas channels separated by a plurality of coolant gas channels; cooling the contaminated gas as it flows upward through the mass transfer unit to cause contaminated gas vapor to condense on the gas channel walls; regenerating the gas channels of the mass transfer unit; and, returning the cleaned gas to the gas atmosphere of high purity argon. The condensing of the contaminant-containing vapor occurs while suppressing contaminant particulate formation, and is promoted by providing a sufficient amount of surface area in the mass transfer unit to cause the vapor to condense and relieve supersaturation buildup such that contaminant particulates are not formed. Condensation of the contaminant is prevented on supply and return lines in which the contaminant containing gas is withdrawn and returned from and to the electrorefiner and mass transfer unit by heating and insulating the supply and return lines.

  9. Method for removing metal vapor from gas streams

    DOEpatents

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

    1996-04-02

    A process for cleaning an inert gas contaminated with a metallic vapor, such as cadmium, involves withdrawing gas containing the metallic contaminant from a gas atmosphere of high purity argon; passing the gas containing the metallic contaminant to a mass transfer unit having a plurality of hot gas channels separated by a plurality of coolant gas channels; cooling the contaminated gas as it flows upward through the mass transfer unit to cause contaminated gas vapor to condense on the gas channel walls; regenerating the gas channels of the mass transfer unit; and, returning the cleaned gas to the gas atmosphere of high purity argon. The condensing of the contaminant-containing vapor occurs while suppressing contaminant particulate formation, and is promoted by providing a sufficient amount of surface area in the mass transfer unit to cause the vapor to condense and relieve supersaturation buildup such that contaminant particulates are not formed. Condensation of the contaminant is prevented on supply and return lines in which the contaminant containing gas is withdrawn and returned from and to the electrorefiner and mass transfer unit by heating and insulating the supply and return lines. 13 figs.

  10. Understanding the factors influencing the removal of heavy metals in urban stormwater runoff.

    PubMed

    Maniquiz-Redillas, Marla C; Kim, Lee-Hyung

    2016-01-01

    In this research, an infiltration trench equipped with an extensive pretreatment and filter bed consisting of woodchip, sand and gravel was utilized as a low impact development technique to manage stormwater runoff from a highly impervious road with particular emphasis on heavy metal removal. Findings revealed that the major factors influencing the removal of heavy metals were the concentration of the particulate matters and heavy metals in runoff, runoff volume and flow rates. The reduction of heavy metals was enhanced by sedimentation of particulates through pretreatment. Fine particles (<2 mm) had the most significant amount of heavy metals, thus, enhanced adsorption and filtration using various filter media were important design considerations. Sediment was most highly attached on the surface area of woodchip than to other filter media like sand, gravel and geotextile. It is suggested that maintenance must be performed after the end of the winter season wherein high sediment rate was observed to maintain the efficiency of the treatment system. PMID:27332837

  11. Application of lactic acid bacteria in removing heavy metals and aflatoxin B1 from contaminated water.

    PubMed

    Elsanhoty, Rafaat M; Al-Turki, I A; Ramadan, Mohamed Fawzy

    2016-01-01

    In this study selected lactic acid bacteria (LAB, Lactobacillus acidophilus, Lactobacillus rhamnosus, Lactobacillus plantrium and Streptococcus thermophiles) and probiotic bacteria (Bifidobacterium angulatum) were tested for their ability in removing heavy metals (HM) including cadmium (Cd), lead (Pb) and arsenic (As) as well as aflatoxin B1 (AFB1) from contaminated water. The biosorption parameters (pH, bacterial concentration, contact time and temperature) of removal using individual as well as mixed LAB and probiotic bacteria were studied. Removal of HM and AFB1 depended on the strain, wherein the process was strongly pH-dependent with high removal ability at a pH close to neutral. The increase in bacterial concentration enhanced the removal of Cd, Pb and As. Also, increasing of contact time and temperature increased the ability of LAB to remove HM. The effect of contact time on Cd removal was slightly different when freshly cultured cells were used. The removal of Cd, Pb and As decreased with the increase in the initial metal concentration. The most effective HM removers were Lactobacillus acidophilus and Bifidobacterium angulatum. The system was found to be adequate for concentrations of HM under investigation. At the end of the operation, the concentration of HM reached the level allowed by the World Health Organization regulations. PMID:27508367

  12. Anaerobic Biochemical Reactor (BCR) Treatment Of Mining-Influenced Water (MIW) - Investigation Of Metal Removal Efficiency and Ecotoxicity

    EPA Science Inventory

    BCR have been successful at removing a high percentage of metals from MIW, while BCR effluent toxicity has not been examined previously in the field. This study examined 4 active pilot BCR systems for removal of metals and toxicity. Removal efficiency for Al, As, Cd, Cu, Ni, Pb...

  13. Filter materials for metal removal from mine drainage--a review.

    PubMed

    Westholm, Lena Johansson; Repo, Eveliina; Sillanpää, Mika

    2014-01-01

    A large number of filter materials, organic and inorganic, for removal of heavy metals in mine drainage have been reviewed. Bark, chitin, chitosan, commercial ion exchangers, dairy manure compost, lignite, peat, rice husks, vegetal compost, and yeast are examples of organic materials, while bio-carbons, calcareous shale, dolomite, fly ash, limestone, olivine, steel slag materials and zeolites are examples of inorganic materials. The majority of these filter materials have been investigated in laboratory studies, based on various experimental set-ups (batch and/or column tests) and different conditions. A few materials, for instance steel slag materials, have also been subjects to field investigations under real-life conditions. The results from these investigations show that steel slag materials have the potential to remove heavy metals under different conditions. Ion exchange has been suggested as the major metal removal mechanisms not only for steel slag but also for lignite. Other suggested removal mechanisms have also been identified. Adsorption has been suggested important for activated carbon, precipitation for chitosan and sulphate reduction for olivine. General findings indicate that the results with regard to metal removal vary due to experimental set ups, composition of mine drainage and properties of filter materials and the discrepancies between studies renders normalisation of data difficult. However, the literature reveals that Fe, Zn, Pb, Hg and Al are removed to a large extent. Further investigations, especially under real-life conditions, are however necessary in order to find suitable filter materials for treatment of mine drainage. PMID:24781327

  14. Influent concentrations and removal performances of metals through municipal wastewater treatment processes.

    PubMed

    Choubert, J M; Pomiès, M; Ruel, S Martin; Coquery, M

    2011-01-01

    This extensive study aimed at quantifying the concentrations and removal efficiency of 23 metals and metalloids in domestic wastewater passing through full-scale plants. Nine facilities were equipped with secondary biological treatment and three facilities were equipped with a tertiary treatment stage. The metals investigated were Li, B, Al, Ti, V, Cr, Fe, Ni, Co, Cu, Zn, As, Se, Rb, Mo, Ag, Cd, Sn, Sb, Ba, TI, Pb and U. Particulate and dissolved metals were measured using 24 h composite samples at each treatment stage. In influents, total concentrations of Cd, Sb, Co, Se, U, Ag, V were below a few microg/L, whereas at the other extremity Zn, B, Fe, Ti, Al were in the range of 0.1 to > 1 mg/L. It was demonstrated that secondary treatment stage (activated sludge, biodisc and membrane bioreactor) were efficient to remove most metals (removal rate > 70%), with the exception of B, Li, Rb, Mo, Co, As, Sb and V due to their low adsorption capacities. With the tested tertiary stages (polishing pond, rapid chemical settler, ozonation), a removal efficiency was obtained for Ti, Cr, Cd, Cu, Zn, Sn, Pb, Fe, Ag and Al, whereas a little removal (< 30%) was obtained for other metals. PMID:21902037

  15. Remediation of heavy metal polluted sediment by suspension and solid-bed leaching: estimate of metal removal efficiency.

    PubMed

    Löser, Christian; Zehnsdorf, Andreas; Hoffmann, Petra; Seidel, Heinz

    2007-01-01

    Remediation of heavy metal polluted sediment by extracting the metals with sulfuric acid can be performed as follows: abiotic suspension leaching, microbial suspension leaching, abiotic solid-bed leaching, and microbial solid-bed leaching. Abiotic leaching means that the acid is directly added, while microbial leaching means that the acid is generated from sulfur by microbes (bioleaching). These four principles were compared to each other with special emphasis on the effectiveness of metal solubilization and metal removal by subsequent washing. Abiotic suspension leaching was fastest, but suspending the solids exhibits some disadvantages (low solid content, costly reactors, permanent input of energy, high water consumption, special equipment required for solid separation, large amounts of waste water, sediment properties hinder reuse), which prevent suspension leaching in practice. Abiotic solid-bed leaching implies the supply of acid by percolating water which proceeds slowly due to a limited bed permeability. Microbial solid-bed leaching means the generation of acid within the bed and has been proven to be the only principle applicable to practice. Metal removal from leached sediment requires washing with water. Washing of solid beds was much more effective than washing of suspended sediment. The kinetics of metal removal from solid beds 0.3, 0.6 or 1.2m in height were similar; when using a percolation flow of 20lm(-2)h(-1), the removal of 98% of the mobile metals lasted 57-61h and required 8.5, 4.2 or 2.3lkg(-1) water. This means, the higher the solid bed, the lower the sediment-mass-specific demand for time and water. PMID:16908047

  16. Heavy metal removal by GLDA washing: Optimization, redistribution, recycling, and changes in soil fertility.

    PubMed

    Wang, Guiyin; Zhang, Shirong; Xu, Xiaoxun; Zhong, Qinmei; Zhang, Chuer; Jia, Yongxia; Li, Ting; Deng, Ouping; Li, Yun

    2016-11-01

    Soil washing, an emerging method for treating soils contaminated by heavy metals, requires an evaluation of its efficiency in simultaneously removing different metals, the quality of the soil following remediation, and the reusability of the recycled washing agent. In this study, we employed N,N-bis (carboxymethyl)-l-glutamic acid (GLDA), a novel and readily biodegradable chelator to remove Cd, Pb, and Zn from polluted soils. We investigated the influence of washing conditions, including GLDA concentration, pH, and contact time on their removal efficiencies. The single factor experiments showed that Cd, Pb, and Zn removal efficiencies reached 70.62, 74.45, and 34.43% in mine soil at a GLDA concentration of 75mM, a pH of 4.0, and a contact time of 60min, and in polluted farmland soil, removal efficiencies were 69.12, 78.30, and 39.50%, respectively. We then employed response surface methodology to optimize the washing parameters. The optimization process showed that the removal efficiencies were 69.50, 88.09, and 40.45% in mine soil and 71.34, 81.02, and 50.95% in polluted farmland soil for Cd, Pb, and Zn, respectively. Moreover, the overall highly effective removal of Cd and Pb was connected mainly to their highly effective removal from the water-soluble, exchangeable, and carbonate fractions. GLDA-washing eliminated the same amount of metals as EDTA-washing, while simultaneously retaining most of the soil nutrients. Removal efficiencies of recycled GLDA were no >5% lower than those of the fresh GLDA. Therefore, GLDA could potentially be used for the rehabilitation of soil contaminated by heavy metals. PMID:27371771

  17. Organic matter and heavy metal removals from complexed metal plating effluent by the combined electrocoagulation/Fenton process.

    PubMed

    Kabdaşli, I; Arslan, T; Arslan-Alaton, I; Olmez-Hanci, T; Tünay, O

    2010-01-01

    In the present study, the treatment of metal plating wastewater containing complexed metals originating from the nickel and zinc plating process by electrocoagulation (EC) using stainless steel electrodes was explored. In order to improve the organic matter removal efficiency, the effect of H(2)O(2) addition to the electrocoagulation (the combined EC/Fenton process) application was investigated. For this purpose, a wide range of H(2)O(2) concentrations varying between 15 and 230 mM was tested. All EC and EC/Fenton processes were performed at an initial pH of 2.6 and at an optimized current density of 22 mA/cm(2). Although up to 30 mM H(2)O(2) addition improved the EC process performance in terms of organic matter abatement, the highest COD and TOC removal efficiencies were obtained for the combined EC/Fenton process in the presence of 20 mM H(2)O(2). Nickel and zinc were completely removed for all runs tested in the present study after pH adjustments. At the optimized operation conditions, the combined EC/Fenton process proved to be an alternative treatment method for the improvement of organic matter reduction as well as complexed metal removal from metal plating industry wastewater. PMID:20453336

  18. Metal-air battery with easily removable anodes

    SciTech Connect

    Niksa, A.J.; Nikasa, M.J.; Noscal, J.M.; Sovich, T.J.

    1990-08-21

    This patent describes a metal-air battery. It comprises: one or more cells. Each cell comprising;a frame having opposed faces; an air cathode sealed to each face of the frame; an access opening in the frame; an anode blank comprising a consumable end inserted through the access opening into the space between the air cathodes and an exposed end protruding from the opening for replacement of the anode blank through the opening; and a labyrinth seal molded directly onto the anode blank between the consumable end and the exposed end sealing the access opening.

  19. Comparison of filter media materials for heavy metal removal from urban stormwater runoff using biofiltration systems.

    PubMed

    Lim, H S; Lim, W; Hu, J Y; Ziegler, A; Ong, S L

    2015-01-01

    The filter media in biofiltration systems play an important role in removing potentially harmful pollutants from urban stormwater runoff. This study compares the heavy metal removal potential (Cu, Zn, Cd, Pb) of five materials (potting soil, compost, coconut coir, sludge and a commercial mix) using laboratory columns. Total/dissolved organic carbon (TOC/DOC) was also analysed because some of the test materials had high carbon content which affects heavy metal uptake/release. Potting soil and the commercial mix offered the best metal uptake when dosed with low (Cu: 44.78 μg/L, Zn: 436.4 μg/L, Cd, 1.82 μg/L, Pb: 51.32 μg/L) and high concentrations of heavy metals (Cu: 241 μg/L, Zn: 1127 μg/L, Cd: 4.57 μg/L, Pb: 90.25 μg/L). Compost and sludge also had high removal efficiencies (>90%). Heavy metal leaching from these materials was negligible. A one-month dry period between dosing experiments did not affect metal removal efficiencies. TOC concentrations from all materials increased after the dry period. Heavy metal removal was not affected by filter media depth (600 mm vs. 300 mm). Heavy metals tended to accumulate at the upper 5 cm of the filter media although potting soil showed bottom-enriched concentrations. We recommend using potting soil as the principal media mixed with compost or sludge since these materials perform well and are readily available. The use of renewable materials commonly found in Singapore supports a sustainable approach to urban water management. PMID:25261749

  20. Removal performance of heavy metals in MBR systems and their influence in water reuse.

    PubMed

    Arévalo, Juan; Ruiz, Luz Marina; Pérez, Jorge; Moreno, Begoña; Gómez, Miguel Ángel

    2013-01-01

    The removal performance of heavy metals by two experimental full-scale membrane bioreactors (microfiltration and ultrafiltration) and the influence of activated sludge total suspended solid (TSS) concentration were studied under real operational conditions. Influent and effluent Be, Sc, V, Cr, Mn, Co, Ni, Cu, Zn, As, Mo, Cd, Ba, Sn, Sb, Pb and U concentrations were analysed by inductively coupled plasma-mass spectrometry. An average contamination rate for most of the analysed heavy metals was observed in raw wastewater, resulting in effluents without limitation for reuse in agricultural destinations according to Spanish law. Removal efficiencies up to 80% were obtained regardless of whether microfiltration or ultrafiltration membranes were used, except for As, Mo and Sb. The removal yields of different heavy metals can be strengthened by increasing the activated sludge TSS concentration, mainly at concentrations above 10 g/L. PMID:23306270

  1. Removing Endotoxin from Metallic Biomaterials with Compressed Carbon Dioxide-Based Mixtures

    PubMed Central

    Tarafa, Pedro J.; Williams, Eve; Panvelker, Samir; Zhang, Jian; Matthews, Michael A.

    2010-01-01

    Bacterial endotoxins have strong affinity for metallic biomaterials because of surface energy effects. Conventional depyrogenation methods may not eradicate endotoxins and may compromise biological properties and functionality of metallic instruments and implants. We evaluated the solubilization and removal of E. coli endotoxin from smooth and porous titanium (Ti) surfaces and stainless steel lumens using compressed CO2-based mixtures having water and/or surfactant Ls-54. The CO2/water/Ls-54 ternary mixture in the liquid CO2 region (25 °C and 27.6 MPa) with strong mixing removed endotoxin below detection levels. This suggests that the ternary mixture penetrates and dissolves endotoxins from all the tested substrates. The successful removal of endotoxins from metallic biomaterials with compressed CO2 is a promising cleaning technology for biomaterials and reusable medical devices. PMID:21499532

  2. Reactivity of Metal Oxide Sorbents for Removal of H{sub 2}S

    SciTech Connect

    Kwon, K.C.; Crowe, E.R.

    1996-12-31

    Removal of hydrogen sulfide contained in hot coal gases produced from integrated gasification combined cycle power generation systems is required to protect downstream combustion turbines from being corroded with sulfur compounds. Removal of sulfur compounds from hot coal gas products is investigated by using various metal oxide sorbents and membrane separation methods. The main requirements of these metal oxide sorbents are durability and high sulfur loading capacity during absorption-regeneration cycles. In this research, durable metal oxide sorbents were formulated. Reactivity of the formulated metal oxide sorbents with simulated coal gas mixtures was examined to search for an ideal sorbent formulation with a high-sulfur loading capacity suitable for removal of hydrogen sulfide from coal gases. The main objectives of this research are to formulate durable metal oxide sorbents with high-sulfur loading capacity by a physical mixing method, to investigate reaction kinetics on the removal of sulfur compounds from coal gases at high temperature and pressure, to study reaction kinetics on the regeneration of sulfided sorbents, to identify effects of hydrogen partial pressures and moisture on equilibrium/dynamic absorption of hydrogen sulfide into formulated metal oxide sorbents as well as initial reaction rates of H{sub 2}S with formulated metal oxide sorbents, and to evaluate intraparticular diffusivity of H{sub 2}S into formulated sorbents at various reaction conditions. The metal oxide sorbents such as TU-1, TU-19, TU-24, TU-25 and TU-28 were formulated with zinc oxide powder as an active sorbent ingredient, bentonite as a binding material and titanium oxide as a supporting metal oxide.

  3. Performance evaluation of intermediate cover soil barrier for removal of heavy metals in landfill leachate.

    PubMed

    Suzuki, Kazuyuki; Anegawa, Aya; Endo, Kazuto; Yamada, Masato; Ono, Yusaku; Ono, Yoshiro

    2008-11-01

    This pilot-scale study evaluated the use of intermediate cover soil barriers for removing heavy metals in leachate generated from test cells for co-disposed fly ash from municipal solid waste incinerators, ash melting plants, and shredder residue. Cover soil barriers were mixtures of Andisol (volcanic ash soil), waste iron powder, (grinder dust waste from iron foundries), and slag fragments. The cover soil barriers were installed in the test cells' bottom layer. Sorption/desorption is an important process in cover soil bottom barrier for removal of heavy metals in landfill leachate. Salt concentrations such as those of Na, K, and Ca in leachate were extremely high (often greater than 30 gL(-1)) because of high salt content in fly ash from ash melting plants. Concentrations of all heavy metals (nickel, manganese, copper, zinc, lead, and cadmium) in test cell leachates with a cover soil barrier were lower than those of the test cell without a cover soil barrier and were mostly below the discharge limit, probably because of dilution caused by the amount of leachate and heavy metal removal by the cover soil barrier. The cover soil barriers' heavy metal removal efficiency was calculated. About 50% of copper, nickel, and manganese were removed. About 20% of the zinc and boron were removed, but lead and cadmium were removed only slightly. Based on results of calculation of the Langelier saturation index and analyses of core samples, the reactivity of the cover soil barrier apparently decreases because of calcium carbonate precipitation on the cover soil barriers' surfaces. PMID:18842283

  4. Microbial removal of toxic metals from a heavily polluted soil

    NASA Astrophysics Data System (ADS)

    Nicolova, Marina; Spasova, Irena; Georgiev, Plamen; Groudev, Stoyan

    2015-04-01

    Samples of a leached cinnamonic forest soil heavily polluted with uranium and some toxic heavy metals (mainly copper, zinc and cadmium) were subjected to cleaning by means of bioleaching with acidophilic chemolithotrophic bacteria. The treatment was carried out in a green house in which several plots containing 150 kg of soil each were constructed. The effect of some essential environmental factors such as pH, humidity, temperature and contents of nutrients on the cleaning process was studied. It was found that under optimal conditions the content of pollutants were decreased below the relevant permissible levels within a period of 170 days. The soil cleaned in this way was characterized by a much higher production of biomass of different plants (alfalfa, clover, red fescue, vetch) than the untreated polluted soil.

  5. WasteWater Treatment And Heavy Metals Removal In The A-01 Constructed Wetland 2003 Report

    SciTech Connect

    ANNA, KNOX

    2004-08-01

    The A-01 wetland treatment system (WTS) was designed to remove metals from the effluent at the A-01 NPDES outfall. The purpose of research conducted during 2003 was to evaluate (1) the ability of the A-01 wetland treatment system to remediate waste water, (2) retention of the removed contaminants in wetland sediment, and (3) the potential remobilization of these contaminants from the sediment into the water column. Surface water and sediment samples were collected and analyzed in this study.

  6. Removal Of Phenol From Wastewater By Using Low-Cost Catalyst From Metal Production

    NASA Astrophysics Data System (ADS)

    Galbičková, Blanka; Soldán, Maroš; Belčík, Michal; Balog, Karol

    2014-12-01

    Utilization of AOPs (Advanced oxidation processes) as an emerging technology for removing of pollutants from wastewater is developed. In this paper, UV photodegradation was used for removing of phenol from wastewater. As a source of UV radiation medium pressure mercury lamp with output 400W was used. The influence of low-cost catalysts on this process was also monitored. Wastes from metal production, red mud and black nickel mud, were used as catalysts.

  7. Removal of chlorine gas by an amine functionalized metal-organic framework via electrophilic aromatic substitution.

    PubMed

    DeCoste, Jared B; Browe, Matthew A; Wagner, George W; Rossin, Joseph A; Peterson, Gregory W

    2015-08-11

    Here we report the removal of chlorine gas from air via a reaction with an amine functionalized metal-organic framework (MOF). It is found that UiO-66-NH2 has the ability to remove 1.24 g of Cl2 per g of MOF via an electrophilic aromatic substitution reaction producing HCl, which is subsequently neutralized by the MOF. PMID:26146024

  8. Heavy metal removal by novel CBD-EC20 sorbents immobilized on cellulose.

    PubMed

    Xu, Zhaohui; Bae, Weon; Mulchandani, Ashok; Mehra, Rajesh K; Chen, Wilfred

    2002-01-01

    Heavy metals are major contributors to pollution of the biosphere, and their efficient removal from contaminated water is required. Biosorption is an emerging technology that has been shown to be effective in removing very low levels of heavy metal from wastewater. Although peptides such as metallothioneins or phytotchelatins are known to immobilize heavy metals, peptide-based biosorbents have not been extensively investigated. In this paper, we describe the construction and expression of bifunctional fusion proteins consisting of synthetic phytochelatin (EC20) linked to a Clostridium-derived cellulose-binding domain (CBD(clos)), enabling purification and immobilization of the fusions onto different cellulose materials in essentially a single step. The immobilized sorbents were shown to be highly effective in removing cadmium at parts per million levels. Repeated removal of cadmium was demonstrated in an immobilized column. The ability to genetically engineer biosorbents with precisely defined properties could provide an attractive strategy for developing high-affinity bioadsorbents suitable for heavy metal removal. PMID:12005515

  9. The Improved Transient Stabilities of HTS Coils by Removing the Insulation and Inserting the Metal Tapes

    NASA Astrophysics Data System (ADS)

    Kim, S. B.; Kajikawa, H.; Ikoma, H.; Joo, J. H.; Jo, J. M.; Han, Y. J.; Jeong, H. S.

    NMR/MRI magnets have a protection device to prevent the damages due to a quench. On the other hand, the protection device design of HTS coils or magnets are very difficult because it has a very low normal zone propagation velocity (NZPV) and complicate behaviors of quench. We have studied the methods to improve the self-protection ability of HTS coils by removing the turn-to-turn insulation and inserting the metal tape instead of insulation. In this paper, the improved transient stabilities and self- protection abilities of HTS coils by removing the insulation and inserting metal tapes will be presented by minimum quench energy (MQE).

  10. Composition, removal, redox, and metal complexation properties of dissolved organic nitrogen in composting leachates.

    PubMed

    He, Xiao-Song; Xi, Bei-Dou; Zhang, Zong-Yong; Gao, Ru-Tai; Tan, Wen-Bing; Cui, Dong-Yu; Yuan, Ying

    2015-01-01

    This study investigated the composition, removal, redox, and metal complexation characteristics of dissolved organic nitrogen (DON) in composting leachates. Results showed that the leachate-derived DON comprised proteinaceous compounds and amines, and most of them were integrated into the fulvic- and humic-like substances. Neutral, basic, acidic, hydroxylic, aromatic, and sulfuric amino acids all were detected in the influent leachates. However, most of them were removed by the biological and physical processes, and only neutral amino acids were detected in the effluent. The DON was not the main contributor to the redox capability of the leachate dissolved organic matter (DOM). However, it exhibited a strong capability for metal complexation. The amines formed strong complexes with the metals Mo, Co, Cr, and Ni, while the proteinaceous matter interacted with the metals Cr and Ni. PMID:25282175

  11. Sunflower stalks as adsorbents for the removal of metal ions from wastewater

    SciTech Connect

    Sun, G.; Shi, W.

    1998-04-01

    Sunflower stalks as adsorbents for the removal of metal ions such as copper, cadmium, zinc, and chromium ions in aqueous solutions were studied with equilibrium isotherms and kinetic adsorptions. The maximum adsorptions of four heavy metals are 29.3 mg/g (Cu{sup 2+}), 30.73 mg/g (Zn{sup 2+}), 42.18 mg/g (Cd{sup 2+}), and 25.07 mg/g (Cr{sup 3+}), respectively. Particle sizes of sunflower stalks affected the adsorption of metal ions; the finer size of particles showed better adsorption to the ions. Temperature also plays an interesting role in the adsorption of different metal ions. Copper, zinc, and cadmium exhibited lower adsorption on sunflower stalks at higher temperature, while chromium showed the opposite phenomenon. The adsorption rates of copper, cadmium, and chromium are quite rapid. Within 60 min of operation about 60--80% of these ions were removed from the solutions.

  12. Removal of heavy metals from wastewater with Bigadic (Tuerkiye) clinoptilolite

    SciTech Connect

    Kurama, Haldun; Kaya, Muammer

    1995-07-01

    In this study, Bigadic upper zone zeolitic tuff, which contains about 87% clinoptilolite was used as an ion exchanger for removal of Pb{sup ++}, Cu{sup ++}, Cd{sup ++} and Hg{sup ++}ions from wastewater. Bench scale experiments with two different glass columns, were carried out continuously under the closed/open circuit conditions. Before ion exchange tests, zeolite samples were treated with NaCl (6ml/min. and 42BV). The effects of particle size, bed volume, pH and flow rate on the ion exchange capacity were determined. Under the best operation conditions, the effect of initial influent solution concentration on ion exchange selectivity was tested. As a result, it was found that the Bigadic clinoptilolite had the following ion exchange capacities; Pb{sup ++}, 0.7540 meg/g; Cu{sup ++}, 0.6986 meg/g; Cd{sup ++}, 0.6580 meg/g; Hg{sup ++}, 0.5530 meg/g.

  13. Potential immobilized Saccharomyces cerevisiae as heavy metal removal

    NASA Astrophysics Data System (ADS)

    Raffar, Nur Izzati Abdul; Rahman, Nadhratul Nur Ain Abdul; Alrozi, Rasyidah; Senusi, Faraziehan; Chang, Siu Hua

    2015-05-01

    Biosorption of copper ion using treated and untreated immobilized Saccharomyces cerevisiae from aqueous solution was investigate in this study. S.cerevisiae has been choosing as biosorbent due to low cost, easy and continuously available from various industries. In this study, the ability of treated and untreated immobilized S.cerevisiae in removing copper ion influence by the effect of pH solution, and initial concentration of copper ion with contact time. Besides, adsorption isotherm and kinetic model also studied. The result indicated that the copper ion uptake on treated and untreated immobilized S.cerevisiae was increased with increasing of contact time and initial concentration of copper ion. The optimum pH for copper ion uptake on untreated and treated immobilized S.cerevisiae at 4 and 6. From the data obtained of copper ion uptake, the adsorption isotherm was fitted well by Freundlich model for treated immobilized S.cerevisiae and Langmuir model for untreated immobilized S.cerevisiae according to high correlation coefficient. Meanwhile, the pseudo second order was described as suitable model present according to high correlation coefficient. Since the application of biosorption process has been received more attention from numerous researchers as a potential process to be applied in the industry, future study will be conducted to investigate the potential of immobilized S.cerevisiae in continuous process.

  14. Colour removal from aqueous solutions of metal-complex azo dyes using bacterial cells of Shewanella strain J18 143.

    PubMed

    Li, Tie; Guthrie, James Thomas

    2010-06-01

    The decoloration treatment of textile dye effluents through biodegradation, using bacterial cells, has been studied as a possible means of solving some of the problems that are associated with the pollution of water sources by colorants. In this paper, the use of whole bacterial cells of Shewanella J18 143 for the reduction of aqueous solutions of selected mono-azo, metal-complex dyes, namely Irgalan Grey GLN, Irgalan Black RBLN and Irgalan Blue 3GL, was investigated. The effects of temperature, pH and dye concentration on colour removal were also investigated and shown to be important. The operative conditions for the removal of colour were 30 degrees C, at pH 6.8, with a final dye concentration of 0.12 g/L in the colour reduction system. This study provides an extension to the application of Shewanella strain J18 143 bacterial cells in the decoloration of textile wastewaters. PMID:20167478

  15. Equilibrium analysis for heavy metal cation removal using cement kiln dust.

    PubMed

    El Zayat, Mohamed; Elagroudy, Sherien; El Haggar, Salah

    2014-01-01

    Ion exchange, reverse osmosis, and chemical precipitation have been investigated extensively for heavy metal uptake. However, they are deemed too expensive to meet stringent effluent characteristics. In this study, cement kiln dust (CKD) was examined for the removal of target heavy metals. Adsorption studies in completely mixed batch reactors were used to generate equilibrium pH adsorption edges. Studies showed the ability of CKD to remove the target heavy metals in a pH range below that of precipitation after an equilibrium reaction time of 24 h. A surface titration experiment indicated negative surface charge of the CKD at pH below 10, meaning that electrostatic attraction of the divalent metals can occur below the pH required for precipitation. However, surface complexation was also important due to the substantive metal removal. Accordingly, a surface complexation model approach that utilizes an electrostatic term in the double-layer description was used to estimate equilibrium constants for the protolysis interactions of the CKD surface as well as equilibria between background ions and the sorbent surface. It was concluded that the removal strength of adsorption is in the order: Pb > Cu > Cd. The experiments were also supported by Fourier transform infrared spectroscopy (FTIR). PMID:25259489

  16. Magnetic sulfide-modified nanoscale zerovalent iron (S-nZVI) for dissolved metal ion removal.

    PubMed

    Su, Yiming; Adeleye, Adeyemi S; Keller, Arturo A; Huang, Yuxiong; Dai, Chaomeng; Zhou, Xuefei; Zhang, Yalei

    2015-05-01

    Sulfide-modified nanoscale zerovalent iron (S-nZVI) is attracting a lot of attention due to its ease of production and high reactivity with organic pollutants. However, its structure is still poorly understood and its potential application in heavy metal remediation has not been explored. Herein, the structure of S-nZVI and its cadmium (Cd) removal performance under different aqueous conditions were carefully investigated. Transmission electron microscopy (TEM) with an energy-dispersive X-ray spectroscopy (EDS) analysis suggested that sulfur was incorporated into the zerovalent iron core. Scanning electron microscopy (SEM) with EDS analysis demonstrated that sulfur was also homogeneously distributed within the nanoparticles. When the concentration of Na2S2O4 was increased during synthesis, a flake-like structure (FeSx) increased significantly. S-nZVI had an optimal Cd removal capacity of 85 mg/g, which was >100% higher than for pristine nZVI. Even at pH 5, over 95% removal efficiency was observed, indicating sulfide compounds played a crucial role in metal ion removal and particle chemical stability. Oxygen impaired the structure of S-nZVI but enhanced Cd removal capacity to about 120 mg/g. Particle aging had no negative effect on removal capacity of S-nZVI, and Cd-containing mixtures remained stable in a two months experiment. S-nZVI can efficiently sequester dissolved metal ions from different contaminated water matrices. PMID:25706223

  17. Fabrication of a new silicone auricular prosthesis without removing the existing metallic framework.

    PubMed

    Goveas, Reiyal; Shrestha, Binit; Srithavaj, M L Theerathavaj; Thaworanunta, Sita

    2014-12-01

    Silicone prostheses require constant repair and refabrication. Auricular prostheses retained with implants have better retention than adhesive-retained prostheses. However, refabrication is complicated if the patient is unwilling to surrender the metallic framework attached to the implants and revert to the use of adhesives. This article describes a technique by which the metal framework of the existing prosthesis need not be removed, thereby improving the patient's quality of life until the new prosthesis is delivered. PMID:24998323

  18. Facilitation Drives the Positive Effects of Plant Richness on Trace Metal Removal in a Biodiversity Experiment

    PubMed Central

    Wang, Jiang; Ge, Yuan; Chen, Tong; Bai, Yi; Qian, Bao Ying; Zhang, Chong Bang

    2014-01-01

    Background Phytoextraction is an environmentally acceptable and inexpensive technique for mine tailing rehabilitation that uses metallophyte plants. These plants reduce the soil trace metal contents to environmentally acceptable levels by accumulating trace metals. Recently, whether more trace metals can be removed by species-rich communities of these plants received great attention, as species richness has been reported having positive effects on ecosystem functions. However, how the species richness affects trace metals removal of plant communities of mine tailing is rarely known. Methodology/Principal Findings We examined the effects of species richness on soil trace metal removal in both natural and experimental plant communities. The root lengths and stem heights of each plant species were measured in order to calculate the functional diversity indices. Our results showed that trace metal (Cu, Cd, Pb and Zn) concentrations in mine tailing soil declined as species richness increased in both the natural and experimental plant communities. Species richness, rather than functional diversity, positively affected the mineralomass of the experimental plant communities. The intensity of plant-plant facilitation increased with the species richness of experimental communities. Due to the incremental role of plant-plant facilitation, most of the species had higher biomasses, higher trace metal concentrations in their plant tissues and lower malondialdehyde concentrations in their leaves. Consequently, the positive effects of species richness on mineralomass were mostly attributable to facilitation among plants. Conclusions/Significance Our results provide clear evidence that, due to plant-plant facilitation, species richness positively affects the removal of trace metals from mine tailing soil through phytoextraction and provides further information on diversity conservation and environmental remediation in a mine tailing environment. PMID:24695538

  19. Final report for the DOE Metal Hydride Center of Excellence.

    SciTech Connect

    Keller, Jay O.; Klebanoff, Leonard E.

    2012-01-01

    This report summarizes the R&D activities within the U.S. Department of Energy Metal Hydride Center of Excellence (MHCoE) from March 2005 to June 2010. The purpose of the MHCoE has been to conduct highly collaborative and multi-disciplinary applied R&D to develop new reversible hydrogen storage materials that meet or exceed DOE 2010 and 2015 system goals for hydrogen storage materials. The MHCoE combines three broad areas: mechanisms and modeling (which provide a theoretically driven basis for pursuing new materials), materials development (in which new materials are synthesized and characterized) and system design and engineering (which allow these new materials to be realized as practical automotive hydrogen storage systems). This Final Report summarizes the organization and execution of the 5-year research program to develop practical hydrogen storage materials for light duty vehicles. Major results from the MHCoE are summarized, along with suggestions for future research areas.

  20. Self-assembled monolayers on mosoporous supports (SAMMS) for RCRA metal removal

    SciTech Connect

    Feng, Xiangdong; Liu, Jun; Fryxell, G.

    1997-10-01

    The Mixed Waste Focus Area has declared mercury removal and stabilization as the first and fourth priorities among 30 prioritized deficiencies. Resource Conservation and Recovery Act (RCRA) metal and mercury removal has also been identified as a high priority at DOE sites such as Albuquerque, Idaho Falls, Oak Ridge, Hanford, Rocky Flats, and Savannah River. Under this task, a proprietary new technology, Self-Assembled Monolayers on Mesoporous Supports (SAMMS), for RCRA metal ion removal from aqueous wastewater and mercury removal from organic wastes such as vacuum pump oils is being developed at Pacific Northwest National Laboratory (PNNL). The six key features of the SAMMS technology are (1) large surface area (>900 m{sup 2}/g) of the mesoporous oxides (SiO{sub 2}, ZrO{sub 2}, TiO{sub 2}) ensures high capacity for metal loading (more than 1 g Hg/g SAMMS); (2) molecular recognition of the interfacial functional groups ensures the high affinity and selectivity for heavy metals without interference from other abundant cations (such as calcium and iron) in wastewater; (3) suitability for removal of mercury from both aqueous wastes and organic wastes; (4) the Hg-laden SAMMS not only pass TCLP tests, but also have good long-term durability as a waste form because the covalent binding between mercury and SAMMS has good resistance to ion exchange, oxidation, and hydrolysis; (5) the uniform and small pore size (2 to 40 nm) of the mesoporous silica prevents bacteria (>2000 nm) from solubilizing the bound mercury; and (6) SAMMS can also be used for RCRA metal removal from gaseous mercury waste, sludge, sediment, and soil.

  1. Characterization of metal removal by os sepiae of Sepiella maindroni Rochebrune from aqueous solutions.

    PubMed

    Li, You-Zhi; Pan, Hong; Xu, Jian; Fan, Xian-Wei; Song, Xian-Chong; Zhang, Qian; Xu, Jin; Liu, Yang

    2010-07-15

    To develop low cost metal adsorbents with less secondary pollution, metal adsorption from the aqueous solutions by the raw os sepiae (ROS) and alkali (NaOH)-pretreated OS (APOS) of the cuttlefish (Sepiella maindroni Rochebrune) was characterized. The capacities of adsorption of ROS and APOS were estimated to be 299.26 mg Cu g(-1) and 299.58 mg Cu g(-1), respectively. Metal adsorption by OS was significantly improved by appropriately increasing initial pH in the solution but hardly affected by temperature change within a wide range of 15-45 degrees C. Cu adsorption of both ROS and APOS was well described neither by Langmuir model nor by Freundlich model. Metal adsorption by OS fell in the order of Fe > Cu approximately = Cd > Zn in the solution with mixed metals, but followed the sequence of Cd > Cu > Fe approximately = Zn in the solutions respectively, with a single metal of Fe, Cu, Cd and Zn. The changes in Ca amounts in OS and solutions in adsorption strongly correlated with removal efficiencies of the metals. Obvious shifts of stretching bands of numbers of groups in OS after and before adsorption and the pretreatment occurred. It was concluded: (1) that metal adsorption by OS involves ion exchange, which occurred mainly between Ca rather than K and Na that OS itself contains and metals that were added in the solution, (2) that metal adsorption-promoting effects by NaOH pretreatment likely involve deprotonation of surface groups in OS, exposure of more functional groups, and increase in specific surface areas and (3) that related mechanisms for adsorption also likely include surface complexation, electrostatic adsorption and even micro-deposition. The results also indicated that OS is a very promising absorbent for metal removal from electroplating wastewater. PMID:20347221

  2. Use of electrocoagulation for removal of heavy metals in industrial wastewaters

    SciTech Connect

    Dalrymple, C.W.

    1995-07-01

    A wide variety of contaminants (heavy metals, suspended solids, colloids, oils, organics) have been successfully removed from wastewater using an electrocoagulation process. An innovative electrocoagulation system is described. This process involves a procedure which subjects dissolved and suspended wastewater contaminants to the simultaneous addition of metal ions in the presence of direct current. During the treatment process ionic and other charged particles in the wastewater are neutralized with oppositely charged ions generating the coagulation of contaminants: The process is called CURE, and presented here with application to wastewaters containing mainly heavy metals.

  3. THE REMOVAL OF METALS AND VIRUSES IN ADVANCED WASTEWATER TREATMENT SEQUENCES

    EPA Science Inventory

    An extensive study of metals and virus removals by advanced wastewater treatment processes was conducted in Dallas, Texas from June 1972 through December 1973. Processes applied to a biologically nitrified effluent included chemical coagulation with alum and/or lime, high-pH lime...

  4. Electrochemical Removal of Metal Cations from Wastewater Monitored by Differential Pulse Polarography

    ERIC Educational Resources Information Center

    Bruce, Delphine; Kuhn, Alexander; Sojic, Neso

    2004-01-01

    Electrodeposition eliminates wastewater pollutants such as electrochemically active metal cations, with different pulse polarography (DPP) scrutinizing the kinetics of the treatment process. These mechanisms produce qualitative and quantitative data about the removal process, while students appreciate the use of electrochemistry in resolving…

  5. Regenerable metallic oxide systems for removal of carbon dioxide: A concept

    NASA Technical Reports Server (NTRS)

    Sutton, J. G.; Heimlich, P. F.; Tepper, E. H.

    1972-01-01

    Design concepts for portable canisters for removal of carbon dioxide are described. One is screen pack configuration consisting of brazed rectangular canister with four metal oxide packs inserted. Other is radial flow canister with perforated central tube. Methods of production and operating principles are presented.

  6. Toxicity, accumulation, and removal of heavy metals by three aquatic macrophytes.

    PubMed

    Basile, A; Sorbo, S; Conte, B; Cobianchi, R Castaldo; Trinchella, F; Capasso, C; Carginale, V

    2012-04-01

    A comprehensive understanding of the uptake, tolerance, and transport of heavy metals by plants will be essential for the development of phytoremediation technologies. In the present paper, we investigated accumulation, tissue and intracellular localization, and toxic effects of cadmium (Cd), lead (Pb), zinc (Zn), and copper (Cu) in three aquatic macrophytes (the angiosperms Lemna minor and Elodea canadensis, and the moss Leptodictyum riparium). We also tested and compared their capacity to absorb heavy metal from water under laboratory conditions. Our data showed that all the three species examined could be considered good bioaccumulators for the heavy metals tested. L. riparium was the most resistant species and the most effective in accumulating Cu, Zn, and Pb, whereas L. minor was the most effective in accumulating Cd. Cd was the most toxic metal, followed by Pb, Cu, and Zn. At the ultrastructural level, sublethal concentrations of the heavy metals tested caused induced cell plasmolysis and alterations of the chloroplast arrangement. Heavy metal removal experiments revealed that the three macrophytes showed excellent performance in removing the selected metals from the solutions in which they are maintained, thus suggesting that they could be considered good candidates for wastewaters remediation purpose. PMID:22567718

  7. FINAL REPORT. REMOVAL OF RADIOACTIVE CATIONS AND ANIONS FROM POLLUTED WATER USING LIGAND-MODIFIED COLLOID-ENHANCED ULTRAFILTRATION

    EPA Science Inventory

    The purpose of this project was to develop, optimize, and evaluate new separation methods for removal of hazardous (radionuclides and toxic non-radioactive contaminants) metal ions from either ground water or aqueous waste solutions produced during Decontamination and Decommissio...

  8. Comparative performance evaluation of multi-metal resistant fungal strains for simultaneous removal of multiple hazardous metals.

    PubMed

    Dey, Priyadarshini; Gola, Deepak; Mishra, Abhishek; Malik, Anushree; Kumar, Peeyush; Singh, Dileep Kumar; Patel, Neelam; von Bergen, Martin; Jehmlich, Nico

    2016-11-15

    In the present study, five fungal strains viz., Aspergillus terreus AML02, Paecilomyces fumosoroseus 4099, Beauveria bassiana 4580, Aspergillus terreus PD-17, Aspergillus fumigatus PD-18, were screened for simultaneous multimetal removal. Highest metal tolerance index for each individual metal viz., Cd, Cr, Cu, Ni, Pb and Zn (500mg/L) was recorded for A. fumigatus for the metals (Cd, 0.72; Cu, 0.72; Pb, 1.02; Zn, 0.94) followed by B. bassiana for the metals (Cd, 0.56; Cu, 0.14; Ni, 0.29; Zn, 0.85). Next, the strains were exposed to multiple metal mixture (Cd, Cr, Cu, Ni, Pb and Zn) of various concentrations (6, 12, 18, 30mg/L). Compared to other strains, B. bassiana and A. fumigatus had higher cube root growth (k) constants indicating their better adaptability to multi metal stress. After 72h, multimetal accumulation potential of B. bassiana (26.94±0.07mg/L) and A. fumigatus (27.59±0.09mg/L) were higher than the other strains at initial multimetal concentration of 30mg/L. However, considering the post treatment concentrations of individual metals in multimetal mixture (at all the tested concentrations), A. fumigatus demonstrated exceptional performance and could bring down the concentrations of Cd, Cu, Ni, Pb and Zn below the threshold level for irrigation prescribed by Food and Agriculture Organization (FAO). PMID:27497228

  9. Heavy metal removal from acid mine drainage by calcined eggshell and microalgae hybrid system.

    PubMed

    Choi, Hee-Jeong; Lee, Seung-Mok

    2015-09-01

    This study investigates the use of calcined eggshells and microalgae for the removal of heavy metals from acid mine drainage (AMD) and the simultaneous enhancement of biomass productivity. The experiment was conducted over a period of 6 days in a hybrid system containing calcined eggshells and the microalgae Chlorella vulgaris. The results show that the biomass productivity increased to ~8.04 times its initial concentration of 0.367 g/L as measured by an optical panel photobioreactor (OPPBR) and had a light transmittance of 95 % at a depth of 305 mm. On the other hand, the simultaneous percent removal of Fe, Cu, Zn, Mn, As, and Cd from the AMD effluent was found to be 99.47 to 100 %. These results indicate that the hybrid system with calcined eggshells and microalgae was highly effective for heavy metal removal in the AMD. PMID:25940497

  10. SITE demonstration of the Dynaphore/Forager Sponge technology to remove dissolved metals from contaminated groundwater

    SciTech Connect

    Esposito, C.R.; Vaccaro, G.

    1995-10-01

    A Superfund Innovative Technology Evaluation (SITE) demonstration was conducted of the Dynaphore/Forager Sponge technology during the week of April 3, 1994 at the N.L. Industries Superfund Site in Pedricktown, New Jersey. The Forager Sponge is an open-celled cellulose sponge incorporating an amine-containing chelating polymer that selectively absorbs dissolved heavy metals in both cationic and anionic states. This technology is a volume reduction technology in which heavy metal contaminants from an aqueous medium are concentrated into a smaller volume for facilitated disposal. The developer states that the technology can be used to remove heavy metals from a wide variety of aqueous media, such as groundwater, surface waters and process waters. The sponge matrix can be directly disposed, or regenerated with chemical solutions. For this demonstration the sponge was set up as a mobile pump-and-treat system which treated groundwater contaminated with heavy metals. The demonstration focused on the system`s ability to remove lead, cadmium, chromium and copper from the contaminated groundwater over a continuous 72-hour test. The removal of heavy metals proceeded in the presence of significantly higher concentrations of innocuous cations such as calcium, magnesium, sodium, potassium and aluminum.