Abstract:
A sorbent particulate material, such as a metal hydroxide-coated sawdust, is made by passing a direct electric current between an anode of a metal capable of forming a flocculent hydroxide and a cathode in a turbulent electrolyte containing the dispersed particulate material, so as to form a metal hydroxide and deposit it on such material. Also described are filters made from the sorbent particulate material and processes of filtering or otherwise removing undesired components from liquid media by means of such product.
Abstract:
The present invention relates to a method of electrochemically removing silver in the form of AgO from a photographic fixer solution containing silver ions without destroying the utility of the solution comprising the steps of applying alternating current having a frequency of between about 0.5 Hz and 800 Hz and a current density of between about 0.1 and 20 amperes per square inch across electrodes immersed in said solution to cause AgO to precipitate at the electrodes. The method can also be practiced above the range of about 20 amperes per square inch at the cost of destroying the utility of the solution. The method can also be used to remove silver in the form of AgO from other solutions.
Abstract:
The invention relates to an oxidation and coagulation apparatus and method especially suitable for use with aquariums (especially salt-water aquariums). Water is withdrawn from the aquarium by a pump, and is fed into the oxidizer and coagulator. The oxidizer and coagulator includes a chamber into which the pump discharges water under pressure, a plurality of electrodes disposed in the chamber and connected up to a source of e.m.f. (AC), a plurality of electrically conductive particles (e.g., graphite) disposed in the chamber, a structure for violently continuously circulating the particles within the chamber so that they continuously impact all of the electrodes, and structure for preventing movement of the electrically conductive particles out of the chamber. An outlet is provided from the chamber and a filter is provided for separating particles and coagulants from the water after discharge from the chamber, and then returning the now-purified water to the aquarium. The electrodes may be stainless steel, yet they will not rust even over extended operation in purifying salt water.
Abstract:
An improved method and apparatus for continuously agglomerating solids of colloidal size of 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.
Abstract:
A vessel is described for facilitating the removal of difficultly oxidizable impurities such as phenol and/or polychlorinated biphenyl from dilute aqueous solutions or dispersions. The vessel contains stacked, packed beds having characteristics of alternating high and low electrical conductivity with separately controlled pairs of electrodes for the two alternate types of beds. An aqueous solution containing contaminants is admitted to the vessel and passed through the successive beds wherein the solution or dispersion is subjected to an alternating current field for decomposition of the contaminants in the high resistivity beds and oxidization thereof in the lower resistivity beds by hydrogen peroxide produced by alternating current electrolysis of water. The preferred electrodes are hollow and water cooled. In addition, the bed is jacketed and cooling water is circulated through the jacket to maintain a more efficient, lower process temperature. The bed having lower resistivity includes conductive particles which may be graphite, and may include activated carbon or equivalent material. Said bed also contains non-conductive particles such particles being coated with catalysts. The catalyst may be an oxidation catalyst, such as the oxides of the metals of Groups IVa, Va, VIb, and VIIb, and specifically preferred are MnO.sub.2, Cr.sub. 2 O.sub.3, Bi.sub.2 O.sub.3 or PbO.sub.2. In the alternative, the catalyst may be a reduction catalyst such as oxides of nickel, iron and oxides of other Group VIII metals. The highly resistive bed is packed with said non-conductive particles only.
Abstract translation:描述了用于促进从稀水溶液或分散体除去难以可氧化的杂质如苯酚和/或多氯联苯的容器。 容器包含具有交替的高和低导电性的堆叠的填充床,具有用于两种替代类型的床的单独控制的电极对。 含有污染物的水溶液进入容器并通过连续的床,其中溶液或分散体经受交流电场,用于分解高电阻率床中的污染物,并且通过产生过氧化氢在较低电阻率床中的氧化 通过交流电解电解水。 优选的电极是中空的并且水冷却。 此外,床被夹套,并且冷却水循环通过护套以保持更有效,更低的工艺温度。 具有较低电阻率的床包括可以是石墨的导电颗粒,并且可以包括活性炭或等效材料。 所述床还包含非导电颗粒,这些颗粒被催化剂涂覆。 催化剂可以是氧化催化剂,例如IVa,Va,VIb和VIIb族金属的氧化物,特别优选的是MnO 2,Cr 2 O 3,Bi 2 O 3或PbO 2。 在替代方案中,催化剂可以是还原催化剂,例如镍,铁的氧化物和其它VIII族金属的氧化物。 高电阻床仅用所述非导电颗粒填充。
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.
Abstract:
A method of electrolytically removing silver from a photographic fixer solution comprising the steps of placing the photographic fixer solution in a cell having an anode chamber and a cathode chamber, with said chamber being separated by a diaphragm having a pore size of between about 1.0 microns to 500 microns and applying a direct current across the anode and cathode to create a current density of between about 0.001 and 5 amperes per square inch at the cathode to thereby cause argentic oxide to precipitate at the cathode and an equivalent amount of elemental sulfur to precipitate at the anode. The cell is preferably maintained at a temperature of between about 20.degree. C. and 60.degree. C. The cell can be operated as a flow cell by maintaining a hydraulic head between the chambers to determine the flow across the diaphragm. When the cell is operated as a flow cell, a minimum specific amount of photographic fixer must be conveyed to the cell to prevent oxidation of sulfur and escape of SO.sub.2 gas.