Abstract: The invention relates to an electrocatalytic or aero-electrocatalytic process for the reducing dissolving of a refractory compound of cerium such as CeO.sub.2. According to this process, the compound to be dissolved is introduced into an aqueous acid solution, e.g. a sulphuric solution, containing an electrochemical carrier constituted by one of the reducing or oxidizing species of a redox pair, whose redox potential is below +1.25 V/SHE, e.g. a ferric salt, a uranyl salt, molecular iodine or oxygen, and continuous generation and/or regeneration takes place by electrolysis of the reducing species of said redox pair.

Abstract: The present invention relates to a method for the decomposition of superalloys and subsequent recovery of the metallic constituents.

Abstract: An electrode for use in electrochemical ion exchange which includes a hydrolysable metal phosphate such as zirconium phosphate (Zr(HPO.sub.4).sub.2) which has been hydrolysed at least in part is regenerated. The electrode is made the anode of an electrochemical cell in which the electrolyte is an aqueous solution containing one or more phosphate ions provided, for example, by a dissolved salt (eg Na.sub.3 PO.sub.4, Na.sub.2 HPO.sub.4 or NaH.sub.2 PO.sub.4) or orthophosphoric acid, or both. Preferably, the electrolyte is acidic (eg pH 2). Operation of the cell reverses the hydrolysis reaction and enhances the performance of the electrode.

Abstract: This invention relates to a method for sterilizing microorganisms and/or decomposing organic and inorganic pollutants in ground soil and ground water by means of a specified direct current applied between at least one pair of electrodes incorporated into the ground soil. For decomposition of the organic and inorganic pollutants, soil particles of the contaminated ground soil are polarized by a voltage applied to the electrodes, or already polarized soil particles are additionally polarized by the applied artificial electric field. The applied electric field is preferably aligned with the natural electric field of the soil particles. The increased polarization of the soil particles causes processes of cathodic reduction at the negatively charged interfaces of the soil particles and simultaneously causes processes of anodic oxidation at the positively charged interfaces of the soil particles.

Abstract: An improvement is proposed in the cleaning treatment of semiconductor silicon wafers in which the conventional step of cleaning with an aqueous solution of an acid is replaced with a cleaning treatment with a temporarily acidic pure water which is produced electrolytically by the application of a DC voltage between an anode and a cathode bonded to the surfaces of a hydrogen-ion exchange membrane so that the acidic cleaning treatment can be performed under mild conditions so as to eliminate the troubles unavoidable in the conventional process. The apparatus used therefor comprises a rectangular vessel partitioned into a central anode compartment, in which the wafers are held in a vertical disposition within an upflow of pure water, and a pair of cathode compartments on both sides of the anode compartment by partitioning with a pair of hydrogen-ion exchange membranes, on both sides of which an anode plate and a cathode plate are bonded.

Abstract: An improvement is proposed in the cleaning treatment of semiconductor silicon wafers in which the conventional step of cleaning with an aqueous solution of an alkali is replaced with a cleaning treatment with a temporarily alkaline pure water which is produced electrolytically by the application of a DC voltage between a cathode and an anode bonded to the surfaces of a hydrogen-ion exchange membrane so that the alkaline cleaning treatment can be performed under mild conditions so as to eliminate the troubles due to formation of COPs unavoidable in the conventional process. In addition, the pure water rinse following the alkali cleaning of the wafers before transfer to the succeeding acidic cleaning step can be omitted to greatly contribute to the improvement of productivity.

Abstract: A method of electrochemically patterning a surface comprises providing an electrolyte overlying the surface and an array of electrodes adjacent the surface and in contact with the electrolyte, and altering the potential of one or more electrodes of the array so as to deposit or remove or chemically modify a substance on the surface adjacent the electrode. Several such treatments can be performed in sequence, using different electrodes of the array. The method is particularly suitable for step-wise chemical synthesis e.g. of oligonucleotides or other oligomers tethered to the surface. Electrode arrays for use in the method are also claimed.

Abstract: A method of purifying nonmetallic, crystalline semiconducting materials useful for room temperature radiation detecting devices by applying an electric field across the material. The present invention discloses a simple technology for producing purified ionic semiconducting materials, in particular PbI.sub.2 and preferably HgI.sub.2, which produces high yields of purified product, requires minimal handling of the material thereby reducing the possibility of introducing or reintroducing impurities into the material, is easy to control, is highly selective for impurities, retains the stoichiometry of the material and employs neither high temperatures nor hazardous materials such as solvents or liquid metals. An electric field is applied to a bulk sample of the material causing impurities present in the sample to drift in a preferred direction.

Abstract: A method and apparatus for ion analysis by ion chromatography uses periodic electrolytic regeneration of a packed bed suppressor. First and second sets of columns, suppressors and detectors connected in series are linked by appropriate valving so that the effluent from the second suppressor can be passed to the first suppressor to be used in the electrolytic regeneration of the first suppressor after detection of analyte in the second detector.

Abstract: Suitable electrolyte conditioning at the electrodes greatly facilitates the transport of desired ions through soil, enhancing the ability of electrokinetic processes to stabilize the soil through cementing reactions. Cationic species are injected at the anode, and anionic species at the cathode, with suitable electrolyte conditioning. For example, if acid or base formation negatively affects transport, chemical conditioning is used to neutralize the acid or base products of electrolysis. Ionic species can be transported through soil at rates of several centimeters a day, even in soils such as clays having a low hydraulic conductivity. Electroosmotic transport can be minimized by appropriate conditioning of the pore fluid chemistry. For example, placement of chemical conditioners with smaller cations at the anode compartment and larger anions at the cathode compartment, or increasing the ion content of the pore fluid (e.g.

Abstract: An electrokinetic system and method are provided for removing charged species from a sample in which said charged species is commingled with at least one radionuclide. The apparatus comprises an anode compartment comprising an anode, a cathode compartment comprising a cathode, and a treatment zone in fluid communication with the anode and cathode compartments for containing the sample. The anode compartment, cathode compartment, and treatment zone are arranged so that a voltage gradient applied between the anode and the cathode induces an electrical current flow through the sample in the treatment zone. The current causes migration of the positively charged species in the sample toward the cathode and the negatively charges species toward the anode. A pH controller is provided for monitoring and adjusting acidity and basicity to facilitate the removal of salts while maintaining contaminants within the sample.

Abstract: Methods for reversibly associating a substrate compound and a solid support are described. In general, the methods feature the use of selectively chargeable moieties. Apparatus for use with the methods of the invention is also described.

Abstract: A method of removing harmful substances, particularly in the region of the earth's surface, wherewith an electrical voltage is applied to electrodes introduced into the soil. To remove the harmful substances, an electric field is established in situ by the electrical voltage, the intensity of which field is so great that harmful substances which are not electrokinetically transportable are broken up and/or degraded in place.

Abstract: This invention relates to a process for electroreclamation of soil material. A plurality of electrodes is brought into current-conducting connection with the soil material to be reclaimed. One or more of the electrodes are brought into current-conducting connection with the positive or negative pole of a source of DC voltage, and the remaining electrodes are brought into contact with the other pole of the source of DC voltage. There are thus formed one or more anodes and one or more cathodes. An electric current is passed through the soil material to be reclaimed between the differently charged electrodes. According to the invention, the physico-chemical parameters of the medium of both the regions adjoining the anode(s) and the regions adjoining the cathode(s) are controlled.