Abstract: The invention provides an apparatus for electrokinetic transport through soil, comprising an electrode and a containment surrounding the electrode, the containment comprising a layer of a porous material and a rigid porous member disposed between the electrode and the porous material to support or secure the first material. The porous material and rigid porous member allow passage of water, hydrogen ions, hydroxyl ions and one or more target ions. A preferred porous material is clay or ceramic and a preferred rigid porous member is a perforated plastic tube.

Abstract: A method for treating a contaminated media. The method comprises disposing electrodes at the contaminated media, injecting a salt-containing solution into contaminated media, applying an electric voltage between electrodes imposed peripherally to the region, forming ions from the salt-containing solution, and migrating the ions between the electrodes across the contaminated media. The ions of the salt-containing solution migrate into at least a portion of the contaminated media to treat the contaminated media.

Abstract: Methods for controlling electroosmotic flow through a porous medium by applying an electric field between a plurality of electrodes positioned in a porous medium, supplying an acid solution to at least one of the electrodes and/or the soil, and supplying a zeta potential modifying compound to at least one of the electrodes is disclosed. The methods can be used to separate organic as well as inorganic contaminants from porous mediums.

Abstract: A process for the in situ remediation of soil comprising introducing at least one co-metabolite for treating contaminants in a contaminated soil region into the contaminated soil region wherein the source of the at least one co-metabolite is at least one root zone located within the contaminated soil region, wherein each root zone contains the root system of a plurality of plants capable of releasing the at least one co-metabolite, and transmitting direct electric current through the contaminated soil region between a first electrode and a second electrode having opposite charge, wherein the first electrode is located at a first end of the contaminated soil region and the second electrode is located at the opposite end of the contaminated soil region.

Abstract: In a method for regulating and optimizing transport of liquid in a porous structure by means of electroosmosis, a pulse pattern applied to one or more electrode pairs which are used during the electroosmosis is regulated by detecting a potential difference .increment.V.sub.p over the electrode pair or electrode pairs during the duration t.sub.3 of a neutral pulse which forms part of the pulse pattern and subsequently regulating either the duration t.sub.3 of the neutral pulse or the duration T.sub.p of the pulse pattern or both on the basis of the detected potential difference .increment.V.sub.p and any change therein from measuring cycle to measuring cycle.

Abstract: A method for dehydrating a porous material using electro-osmosis, includes applying a pattern of D.C. voltage pulses to an anode system embedded in the porous material, wherein the anode system is electrically interactive with a cathode structure embedded in earth, and wherein the pattern of D.C. voltage pulses, has a pulse period T in a range from about 3 to about 60 seconds, and each pulse period T includes a positive pulse duration of T+ from about 0.7 T to about 0.97 T, a negative pulse duration of T- from about 0.01 T to about 0.05 T, and a neutral pulse duration of T.sub.p from about 0.02 T to about 0.25 T. In another embodiment, each pulse period includes two or more positive pulses separated by at least one of either a negative pulse or a neutral pulse, with the positive pulse duration being the combined duration of the two positive pulses.

Abstract: Abrasive components and water are recovered from an aqueous chemical mechanical slurry used for planarization of semiconductor materials. The slurry effluent is preferably brought to a neutral pH, and cooled to a temperature between about 0.degree. C. and about 15.degree. C. An electrical potential can be applied to the slurry effluent to facilitate agglomeration and separation of particles of abrasive material in the slurry effluent. In one embodiment, the slurry effluent is introduced into a process chamber at ambient temperature and pressure, and supernatant liquid separated from the process chamber is then subjected to a reduction of pressure in a vacuum chamber to cause gas entrapped in the supernatant liquid to bubble to the surface of the supernatant liquid for further separation and collection of water and abrasive particles from the slurry effluent. In another embodiment, slurry effluent is filtered through one or more self-cleaning reversible gross particle filter assemblies.

Abstract: Methods for determining the parameters critical in designing an electrokinetic soil remediation process including electrode well spacing, operating current/voltage, electroosmotic flow rate, electrode well wall design, and amount of buffering or neutralizing solution needed in the electrode wells at operating conditions are disclosed These methods are preferably performed prior to initiating a full scale electrokinetic remediation process in order to obtain efficient remediation of the contaminants.

Abstract: The present invention discloses the doping of rare earth elements into porous silicon, resulting in enhancement of luminescence. The doping is an electro-chemical process using constant voltage bias across the two electrodes in which the anode is porous silicon and the cathode is platinum. The doping process involves a well-defined solution of electrolytes that controls the conductivity of the solution, and set values of constant voltages that selectively allow the desired rare earth elements being doped into porous silicon.

Abstract: A process directed to preparing surfactant-polycrystalline inorganic nanostructured materials having designed microscopic patterns. The process includes forming a polycrystalline inorganic substrate having a flat surface and placing in contact with the flat surface of the substrate a surface having a predetermined microscopic pattern. An acidified aqueous reacting solution is then placed in contact with an edge of the surface having the predetermined microscopic pattern. The solution wicks into the microscopic pattern by capillary action. The reacting solution has an effective amount of a silica source and an effective amount of a surfactant to produce a mesoscopic silica film upon contact of the reacting solution with the flat surface of the polycrystalline inorganic substrate and absorption of the surfactant into the surface. Subsequently an electric field is applied tangentially directed to the surface within the microscopic pattern.

Abstract: Halogenated organics contaminating soil formations are decomposed by an applied voltage-enhanced Grignard reaction with metallic magnesium, either pure or in alloy form, that has been lowered into the soil formation, in conjunction with hydrolysis of the resulting organomagnesium halide to release the halogen from the starting contaminant. Renewal of the magnesium surface to permit an enhanced decomposition is achieved by connection of the magnesium electrode to an electric potential generator and applying the potential either continuously or in pulse-wise manner, preferably repeatedly reversing the applied potential to electrochemically clean the magnesium-containing electrode surface. Dissolved Cr(VI) is likewise reduced to chromium of lower oxidation states and thus rendered less toxic.

Abstract: Soils are decontaminated in situ by transporting peroxysulfate ions through the soil under the influence of an electric field. The electric field is maintained between one or more anodes and one or more cathodes inserted directly into the contaminated soil and geometrically disposed relative one to the other to take full advantage of a positively biased DC voltage applied between said one or more anodes and one or more cathodes. An aqueous solution of a strong oxidant, either peroxymonosulfate or peroxydisulfate, is added to the contaminated soil. The electric field induces the movement of peroxysulfate ions principally by electromigration and to a lesser extent by electroosmosis. Organic contaminants in the soil are oxidized by the peroxysulfate ions. For very recalcitrant contaminants, electric field-induced heating of the soil produces sulfate radical anions. In most cases the peroxysulfate ions or sulfate radical anions oxidize the contaminants to carbon dioxide and mineral acids.

Abstract: To decontaminate soil, a generally thin porous medium is used. A cathode is applied to one face of the porous medium and an anode is spaced apart from the other face of that porous medium to define a generally thin spacing for receiving a generally thin layer of soil to be decontaminated. An electric potential is applied to the first and second electrodes in view of transferring the contaminants from the thin layer of soil to the porous medium. A porous membrane may be positioned between the thin layer of soil and the anode. The system may be of the conveyor type to enable displacement of the porous medium, the porous membrane, and the layer of soil between the anode and the cathode. Also, the system may comprises a series of at least two pairs of anode and cathode supplied with electric potentials of different amplitudes.

Abstract: Abrasive components and water are recovered from an aqueous chemical mechanical slurry used for planarization of semiconductor materials. The slurry effluent is preferably brought to a neutral pH, and cooled to a temperature between about 0.degree. C. and about 15.degree. C. An electrical potential can be applied to the slurry effluent to facilitate agglomeration and separation of particles of abrasive material in the slurry effluent. In one embodiment, the slurry effluent is introduced into a process chamber at ambient temperature and pressure, and supernatant liquid separated from the process chamber is then subjected to a reduction of pressure in a vacuum chamber to cause gas entrapped in the supernatant liquid to bubble to the surface of the supernatant liquid for further separation and collection of water and abrasive particles from the slurry effluent. In another embodiment, slurry effluent is filtered through one or more self-cleaning reversible gross particle filter assemblies.

Abstract: A method is described for the in-situ cleaning by means of microorganisms of a polluted soil portion which contains ground water. In this method, the soil portion to be cleaned is enclosed, and one or several electrodes which are permeable to liquid are placed in or adjacent the soil portion. A negative or positive voltage is applied to these electrodes. The enclosure of the polluted soil portion takes place in such a manner that the ground water present in the soil portion flows mainly through the one or several electrodes.

Abstract: Disclosed is an electrokinetic soil decontamination system that uses special electrode wall configurations, treatment wall configurations, and a combination electrode/treatment wall. A special emplacement method for all the flowable wall materials is used and special wall material compositions are disclosed.

Abstract: Disclosed are methods for electrochemically remediating soil, clay or other media contaminated with organic pollutants using Fenton's Reagent. In the methods, anodes and cathodes are provided in wells formed in the contaminated medium. Anolyte and catholyte solutions are circulated to deliver iron ions to anodes and to deliver peroxide ions to cathodes in the medium. A potential difference is applied across the medium to cause the peroxide ions and iron ions to migrate toward each other and through the medium. The organic contaminants are destroyed in the medium in reactions with the peroxide ions and iron ions. The physicochemical condition of the electrolyte(s) is monitored and adjusted as necessary to control pH and to permit recycling of the electrolyte to the electrodes. Alternatively, peroxide ion can be generated in situ using an air depolarized cathode.

Abstract: An integrated electrochemical soil remediation method and apparatus for treating contaminated soils, especially those contaminated with mixtures of nonvolatile organic contaminants, ionic contaminants and volatile organic compounds are disclosed. Remediation may be achieved by electrochemically enhancing biodigestion of organic contaminants (using microorganisms present in or added to soil), electrochemically removing ionic contaminants and electrochemically removing volatilized organic contaminants by applying a vacuum over the soil being treated, as dictated by the nature of contamination. Physicochemical conditions of the electrolyte and the soil are managed by monitoring and adjusting the electrolyte. Nutritional needs of microorganisms for biodigestion are adjusted as necessary through the electrolyte.

Abstract: A method for dehydrating capillary materials such as moist walls and/or floors of a building structure of masonry or concrete through the principle of electro-osmosis by applying pulsating DC voltage of a specific pulse pattern to primary electrode means embedded in said structure, said primary electrode means (4) forming anode means, and secondary electrode means (5) embedded in the ground outside the structure and forming cathode means to be interactive with said anode means, said pulsating voltage having a pulse pattern with a total pulse period T, comprised of a positive pulse of duration T+, a negative pulse of duration T-, and a neutral period or pause of duration Tp, wherein:0.8T<T+.ltoreq.0.98T;0.0T<T-.ltoreq.0.05T;0.02T<Tp.ltoreq.0.15T;and3 seconds<T.ltoreq.60 seconds.Suitably, T+=0.95 T; T-=0.01 T; and Tp=0.04 T.

Abstract: A method is provided for the electrokinetic decontamination of land or other material comprising soil in which a direct current is applied between at least one cathode (2) and at least one anode (4) positioned in or on said soil. The anode (4) is a carbon felt wrapped around current (10) and electrolyte feeders and the cathode (2) is contained in a porous housing (6) through which electrolyte is able to pass. On application of current there is electrokinetic movement of cations and other soil contaminants towards the cathode which pass through the porous housing and into the catholyte. The thus loaded catholyte is circulated through a treatment plant.

Abstract: A process of remediation of cationic heavy metal contamination from soil utilizes gas phase manipulation to inhibit biodegradation of a chelating agent that is used in an electrokinesis process to remove the contamination, and further gas phase manipulation to stimulate biodegradation of the chelating agent after the contamination has been removed. The process ensures that the chelating agent is not attacked by bioorganisms in the soil prior to removal of the contamination, and that the chelating agent does not remain as a new contaminant after the process is completed.

Abstract: An apparatus and method for soil remediation replaces specific ions in the soil electrochemically, using a DC voltage source and special multicompartment anodes and cathodes, each comprising an inner compartment containing electrolyte and a submerged electrode, a salt bridge connecting the electrolyte to an outer compartment containing a specific solution with replacement ions for soil remediation, and a membrane holding in the replacement solution. The membrane is put into contact with the soil, allowing electrical contact and ion migration while keeping the solution inside the anode or cathode. The multicompartment structure prevents the hydroxide and hydronium ion emplacement that causes acid and base fronts to form.

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: 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: 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.

Abstract: Disclosed is an electrokinetic soil decontamination method using closely spaced like electrode assemblies, special panel electrode configurations, an electrode emplacement process which leaves the soil in-situ, and a purge fluid conditioning and circulation process that results in reduced costs for soil decontamination. Panel electrode assemblies, tubular electrode assemblies and treatment panel assemblies are also disclosed.