Westinghouse Electric Corporation

Other

The United States of America As Represented by the United States

The United States of America As Represented by the Secretary of

The Scientific Ecology Group. Inc.

David C Grant

Edward Jean Lahoda

Michael C Skriba

Edward F Sverdrup

John Bartko

Thomas V Congedo

Arthur L Wolfe

Steven H Peterson

Ching-Yu Lin

Herbert A Burgman

Robert E Witkowski

Albert J Dietrich

William D Partlow

Leland L Learn

James D Smith

Thomas S Snyder

William A Byers

Deborah P Partlow

Karl F Schoch, Jr

David F McLaughlin

John G Seidel

William M Alvino

Robert D Burack

Wen-Ching Yang

Frank H Ruddy

Ivan A Martorell

Dwight F Goad

Carol Lynn Kelly

Joseph L Gonzalez

Thomas Stephen Snyder

Arthur W Ott

Francis Talko

James T Hallman

Lori West

Anuj J Saha

Nicholas D'Amico

Carmine M Mancuso

C P Keegan

Martin Brownstein

The invention provides a method and processing system for removing both anionic and cationic technetium complexes from an aqueous solution by adjusting the pH of the solution to greater than approximately 2, and directing the solution into an integrated resin and electrochemical plating device. The integrated resin and plating device has a resin bed or resin membrane in which is disposed one or more cathodes, and one or more anodes. A potential generator produces at least a 1 volt potential between the cathodes and the anodes. As the solution passes through the resin, the technetium complexes are adsorbed onto it. When a sufficient concentration of technetium complexes is adsorbed, the plating process can atlernatively be driven to plate out the technetium onto the cathodes, or to collect various species in system anolytes/catholytes.

Robust technetium removal method and system

Soil comprising small soil particles, clay and silt particles, humus, fine vegetation, and contaminated with soluble or insoluble radioactive species is treated by first introducing an aqueous extracting solution comprising a mixture of sodium and potassium carbonate (or bicarbonate), or ammonium carbonate (or bicarbonate) into the soil to solubilize and disperse the radioactive species into solution. The extracting solution has a pH greater than or equal to about 7.5. Contaminated fine vegetation then is separated from the soil and extracting solution. Next, an acid like hydrochloric acid is introduced into the soil. The acid is added in an amount sufficient to lower the pH of the extracting solution at which point desirable organic material will substantially precipitate or coagulate from the extracting solution. The cleansed soil particles, including organic matter, is separated from the contaminated extracting solution. Radioactive species are then removed from the extracting solution, which then may be reused.

Method for remediating soil containing radioactive contaminants

The present invention provides methods and processes for immobilizing and solidifying harmful heavy metal and radioactive species within a waste material. The processes of the present invention are also particularly advantageous for immobilizing and solidifying nitrate compounds with a waste material. One embodiment of the present invention is a method that can be carried out by admixing the waste material with cement and a complexant compound to form a grout admixture. Preferably, the complexant compound is an iron compound that can form a hydrated iron oxide in the presence of an aqueous solution. This grout admixture is then allowed to cure and solidify. The grout admixture is placed within a suitable containment vessel for final storage and disposal.

Process for solidification and immobilization of harmful waste species

A borated aqueous solution from a nuclear reactor coolant system dilute chemical-decontamination process or from an equipment washing process which has been contaminated with radioactive metals or heavy metals including cobalt, nickel, chromium, iron, manganese, lead or mercury and with a chelating agent, detergent or soap is treated with an oxidizing agent to oxidize the chelating agent, detergent or soap and to precipitate the contaminant metals. The contaminant metals are then separated from the solution by centrifugal filtration, micromembrane belt filtration or magnetic separation. Advantageously, a very small volume of precipitate may then be buried and the decontaminated solution may be recycled or further treated and released for other uses.

Method of treating a contaminated aqueous solution

A system for determining depth profiles of concentrations of hazardous elements in soils comprises a neutron source for generating neutrons of a first energy level and irradiating a volume of soil with the neutrons. Nuclear reactions are effected within the soil and gamma radiation is emitted from the soil. The system also includes an array of gamma detectors for detecting gamma radiation emitted from the soil; source electronics for controlling the width of regularly repeated pulses of neutrons generated by the neutron source; detector electronics associated with the gamma detectors for amplifying and digitalizing signals generated by the gamma detectors and storing data representing the digitalized signals; spectral analysis software for analyzing the data and determining the concentrations of selected target elements in the soil; and an acquisition interface module (AIM). The AIM controls the timing of the source and detector electronics such that the neutron source generates neutrons in regularly repeated bursts of a prescribed pulse width and the detectors and detector electronics detect gamma rays during a plurality of time intervals associated with the burst and acquire groups of data. Each group is indicative of a number of gamma rays emitted and their energy levels during a corresponding time interval. The system also includes a mobile platform carrying the neutron source, array of gamma ray detectors and software for determining a depth profile of a target element. Trace elements can also be detected with the disclosed system.

Prompt gamma neutron activation analysis system

A method for segregating fines from the clean coarse fraction of the soil, preparing the contaminated fines for subsequent processing, and then separating the contaminants from the clean fines. The process produces a small, highly concentrated contaminanth fraction and a large fraction of clean soil. Metals, metallic compounds, and/or radioactive contaminants are removed from the fine fraction using either gravity separation, multistage gravity separation, a centrifugal jig, regular magnetic or paramagnetic separation using a high gradient magnetic separator, and/or a superconducting separator. Preparation of the fines requires selective segregation of the targeted particles size range and the removal of interfering soil fractions, and vegetation such as root hairs. This preparation is accomplished by a combination of attrition scrubbing, countercurrent jigging, and screening.

Process for the remediation of contaminated particulate material

The concentrations of residual heavy metal contaminants in the particulate material in a slurry produced in a particulate material washing process are monitored on-line and can be used to control the washing process. In alternative embodiments of the invention, x-rays, thermal neutrons or laser beams are directed at the slurry as it flows through a flow cell to induce emission of secondary x-rays, gamma rays or light, respectively, characteristic of the heavy metal contaminants and constituents representative of the solids contents of the slurry. These characteristic energies are measured and used to determine the concentration in ppm of the residual heavy metal contaminants in the particulate material within the slurry.

System and method for on-line monitoring and control of heavy metal

A process system is disclosed for the treatment of a waste sand material containing metal contaminants. The waste sand material is the product of sandblasting techniques used to remove paint. The metal contaminants generally include lead, copper, chromium, mercury and cadmium, among other heavy metals. The process particularly provides for the concentration of the lead contaminant in a waste sand that can be economically reclaimed or disposed in an environmentally safe manner. The process also produces a cleaned sand that contains only residual amounts of the metallic contaminants in environmentally acceptable levels. The process provides for the contacting of the waste sand material with a paint decomposer, attrition abrading this sand slurry, size separating the attrition abraded slurry to form a waste sand slurry and a cleaned sand, and removing a portion of the excess water content in the waste sand slurry.

Method for treatment of waste sand

Solutions such as for example drinking water, ground water and extracting solutions contaminated with heavy metals and radioactive species, singly or in combination, are treated by first treating the contaminated solution with silicate and ammonium hydroxide solution precipitants. Then the contaminated solution is separately treated with an acid which gels, polymerizes and/or precipitates the contaminant-containing silica matrix to form an easily dewaterable and separable solid. The solid contaminants are readily removed from the cleansed solution by filtration means. The process utilizes a novel combination of steps which maximizes contaminant removal, minimizes waste volume, and produces a treatable waste solid. The preferred precipitants are sodium silicate, and ammonium hydroxide. The preferred mineral acid is hydrochloric acid.

Solution decontamination method using precipitation techniques

The present invention provides an improved design for the hindered settling bed within a mineral jig. The hindered settling bed contains relatively low density materials that can be used in conjunction with high density materials to aid in the separation of particulate materials within the mineral jig. The presence of the relatively low density barrier materials in the settling bed allow for the separation to occur with less channelling of the separated material through the bed area.

Modified mineral jig

Solutions such as for example groundwater, drinking water, extracting solutions and effluents contaminated with metals, radioactive species and organics, singly or in combination, are treated by first removing undesirable oxidizing agents from the contaminated solution. Then the contaminated solution is separately treated with aqueous solutions of ferrous sulfate and hydroxide, which precipitate substantially all of the contaminants. Next, the precipitate is treated with a flocculant and/or a coagulant to form an easily dewaterable and separable solid. The solid contaminants are readily removed from the cleansed solution. The process utilizes a novel combination of steps which maximizes contaminant removal, minimizes waste volume, and produces a recyclable solution and a manageable waste stream. The preferred hydroxide solutions are sodium hydroxide, calcium hydroxide, and ammonium hydroxide.

Solution decontamination method using precipitation and flocculation

A method for removing and stabilizing in-situ soluble heavy metal contaminants in land formations which comprises introducing into said formation an aqueous remediation solution comprising naturally-occurring ions present in said formation and remediation ions. The remediation solution selectively solubilizes and mobilizes the heavy metal contaminants into solution while substantially suppressing the displacement of said naturally-occurring ions from said formation. The method is effective with heavy metals which exist in both anionic and cationic form, and may be used to treat land formations below the surface to reduce soluble heavy metal contamination to a few parts per billion.

In-situ restoration of contaminated soils and groundwater

Particulate material such as for example soil contaminated with heavy metals, radioactive species and organics, singly or in combination, is treated by first washing the contaminated material with a contaminant mobilizing solution comprising a leaching agent, a surfactant or a mixture thereof. Large particles, typically greater than 5 mm are mechanically separated, washed with water and returned to the site as recovered soil. Fines, along with contaminants dissolved or dispersed in the contaminant mobilizing solution are separated from intermediate sized particles by a countercurrent flow of the contaminant mobilizing solution, preferably in a mineral jig. The intermediate sized particles are then abraded in an attrition scrubber to dislodge attached mineral slimes or fines. These additional fines are separated from the intermediate sized particles with a countercurrent flow of wash water in a second mineral jig. For some applications, the intermediate sized particles can also be abraded in an attrition scrubber prior to size separation in the first mineral jig. The slurry of intermediate sized particles and wash water discharged from the second mineral jig is dewatered to produce additional recovered soil. If the contamination includes insoluble heavy metal particles, they are separated from the effluent discharged from the second mineral jig by density separation preferably in a cross-current flow jig, prior to dewatering. Various techniques can be used to separate the fines and the contaminants dissolved and dispersed in the waste slurries discharged by the two mineral jigs used for countercurrent flow size separation from the contaminant mobilizing solution which is recycled.

Method and apparatus for cleaning contaminated particulate material

A method for removing contaminated resin particles from soils. The method entrains the resin particles and fines from the soil, which, due to the difference in specific gravity between resin and soil particles, results in a significant disparity between particle size of the entrained resin and the entrained fines. This, in turn permits the fines to be screened from the resin and the larger soil particles, which have not been entrained, to settle out from the mixture.

Method for decontaminating soil containing resins

Surfactants in an aqueous solution is recovered from polychlorinated biphenyls and other aromatic organic compounds contaminating the solution. An electrical current is passed through a surfactant-containing aqueous solution contaminated with a colloidal dispersion of organic compounds at a voltage sufficient to electrochemically breakup the dispersion without polymerizing the surfactant. The contaminating aromatic organic compounds are then separated from the surfactant-containing aqueous solution. The separated surfactant-containing aqueous solution may be recirculated to a waste treatment process for cleaning additional organic compounds from contaminated equipment.

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Gibsonia, PA, United States of America

David C Grant