Abstract:
The invention relates to a membrane assembly and processes for the utilization of the membrane assembly, or membrane assemblies having like properties. The membrane assembly comprises intermixed layers of capillary material and high dielectric constant impermeable material, forming capillary channels parallel to the direction of ion transport through the membrane. The membrane is anion permeable, does not have membrane potential and will not foul even over extended operation, allows cross-flow of anions and cations, and is highly efficient. It is possible to remove complex metals from any contaminated acid by electrodialysis, such as removing vanadium and uranium in recoverable form from contaminated phosphoric acid, while producing food grade phosphoric acid in the process. Additionally, simple metals may be removed from mine waste liquids (from leaching), chlorine can be produced from a chloride containing salt, and chromium can be removed from chromium contaminated water by electrolysis. Milling sludge can be treated to form water, caustic, and acid, and mineralized water can be treated to form de-mineralized water, by subjecting the feed liquids to electrodialysis.
Abstract:
A porous layer is provided on one or both surfaces of a mass-transfer membrane to enhance or modify the passage of ions. The membrane may be a film of any of a variety of polymeric materials, and the porous layer may be a surface layer on the membrane or a separate porous structure placed in contact therewith. The porous layer or layers render certain normally ion-impermeable polymeric films capable of passing ions in an electrodialysis-type system.
Abstract:
A method and device provide for the deionization and contaminants removal or degradation of aqueous liquids, particularly drinking water. The water is caused to flow in a first direction and while flowing it is treated so as to simultaneously effect deionization via electromigration and degradation or removal of the contaminants therein on particle surfaces. The water flows upwardly through a bed formed by a mixture of conductive and non-conductive particles, such as sand and graphite particles, with the particles of the bed being separated from an anode (mounted on one side of the bed) by an anionic membrane, and a cathode (mounted on the other side of the bed) by a non-ionic porous membrane. According to the invention the following ions and contaminants can be destroyed, or removed from, the water: calcium, magnesium, and other water hardening ions; sodium, iron, bacteria; chlorine, phenol, odor and color contaminants; and pesticides.
Abstract:
An electrochemical process for reducing the level of contaminants in an aqueous electrolyte containing the contaminants comprising: suspending particles in the electrolyte in a reaction zone defined by a pair of electrodes to obtain a suspension containing from 1 to 40% by volume of the particles, establishing high turbulence sufficient to maintain the particles in a state of violent agitation, and passing an electric current between the electrodes to generate an electric field in the turbulent electrolyte in the reaction zone. Advantageously the turbulence of the electrolyte corresponds to a Reynolds number above about 3,000 and preferably is in the range of about 10,000 to 50,000. Apparatus for carrying out the process is also disclosed.
Abstract:
Oxidizable contaminants in waters, such as feed waters and waste waters wherein they are present in relatively large or small proportions, are removed therefrom by alternating current electrolysis in an electrolytic cell containing catalyst-containing particles, the catalyst of which is an oxidation catalyst such as MnO.sub.2, Cr.sub.2 O.sub.3, Bi.sub.2 O.sub.3, or PbO.sub.2. The process and apparatus of the invention are especially useful for the removal of difficultly oxidizable impurities, such as phenol, from dilute aqueous solutions or dispersions. Included within the invention is the improved removal of such impurities by sequential treatments in accordance with the described processes. Also disclosed are the production of hydrogen peroxide by alternating current electrolysis of water; the oxidation of phenolic compounds; the reactivation of at least partially inactivated carbon adsorbents by subjection to alternating current; and the concentration of chemical impurities from activated carbon by adsorption on particles thereof, followed by desorption by application by alternating current.
Abstract:
A membrane assembly for electrochemical processes, and a method of constructing an electrochemical cell utilizing the membrane assembly, are provided. A self-supporting thick block consisting essentially of membrane material has an electrode chamber formed therein extending the length of the height thereof. The membrane assembly block comprises a plurality of layers of material contacting each other and forming the membrane with the chamber extending through the layers, perpendicular to them. An electrode and electrolyte are disposed in the electrode chamber.
Abstract:
The invention relates to a membrane assembly and processes for the utilization of the membrane assembly, or membrane assemblies having like properties. The membrane assembly comprises intermixed layers of capillary material and high dielectric constant impermeable material, forming capillary channels parallel to the direction of ion transport through the membrane. The membrane is anion permeable, does not have membrane potential and will not foul even over extended operation, allows cross-flow of anions and cations, and is highly efficient. It is possible to remove complex metals from any contaminated acid by electrodialysis, such as removing vanadium and uranium in recoverable form from contaminated phosphoric acid, while producing food grade phosphoric acid in the process. Additionally, simple metals may be removed from mine waste liquids (from leaching), chlorine can be produced from a chloride containing salt, and chromium can be removed from chromium contaminated water by electrolysis. Milling sludge can be treated to form water, caustic, and acid, and mineralized water can be treated to form de-mineralized water, by subjecting the feed liquids to electrodialysis.
Abstract:
A membrane assembly, useful as a membrane in electrodialytic and electrolytic cells, is made by holding together a plurality of thin layers of membrane material under pressure and with boundary layers of liquid covering their major surfaces. Such membrane assemblies allow the passage therethrough of ions when an electric potential difference is impressed across the membrane assembly but effectively bar the passage of water and gases. They also bar or limit ionic and salt mass transfer in the absence of such a potential difference (during non-use of the cell). They make excellent long lasting cell components, capable of being manufactured simply and economically from any of a variety of membrane materials to produce membranes of desired properties.
Abstract:
Apparatus and method for the dewatering of slimes and sludges. An anode and cathode are provided with the sludge disposed between the electrodes, and with a material for providing a continuation of the boundary layer of the sludge disposed in intimate contact with at least the cathode between the cathode and the sludge, the material allowing the passage of water therethrough, and the cathode being constructed to allow passage of water therethrough. The sludge to be treated is maintained between the electrodes during treatment, and structure is provided to ensure continuous contact between the electrodes and the sludge or the like during treatment even as the volume of the sludge decreases due to water removal. The treatment may be continuous or batch, and by practicing the invention it is possible to render sludge incapable of being dewatered by ambient evaporation so that it is capable of being dewatered by ambient evaporation, while applying only about 200 kwh or less of energy; and it is possible to produce a product sufficiently free of heavy metals to be safely used as a fertilizer from sewage sludge containing significant amounts of heavy metals since the heavy metals pass out of the sludge with the water removed therefrom.
Abstract:
An improved method and apparatus for continuously agglomerating solids of colloidal size or larger suspended in a liquid is disclosed. The process comprises passing the liquid between spaced electrode plates in the presence of a fluidized bed of conductive particles, and subjecting said liquid suspension to an electric field from alternating current applied across said electrodes through the conductive particles of said bed. The turbulence of the particles in said bed has been found to improve conductivity and current efficiency, minimize electrode erosion, and by a mechanical, scrubbing action of the bed particles, minimize fouling or scaling of the electrodes so that the suspending forces of said solids are rapidly and efficiently broken. The agglomerated solids may then be separated from the liquid by conventional means such as skimming, settling, flotation and the like.