Abstract:
A process of demineralizing a liquid containing organic matter and inorganic salts in solution, in which the treatment of the liquid comprises the following steps: the liquid is percolated over a strong cationic ion exchange resin for monovalent ions; both a batch of liquid from the preceding step and a brine for receiving ions from that liquid are caused to circulate in loops through at least one "two-compartment" electrodialyzer comprising a plurality of anionic membranes interposed between a plurality of cationic membranes; and the brine whose salt concentration lies in the range 90 grams per liter (g/l) to 110 g/l is used to regenerate the ion exchange resin.
Abstract:
The present invention provides a system and a process for removing contaminants such as CO.sub.2 and mobile cations and anions from aqueous solutions. The system and the process contemplate the use of thermally sterilizable aqueous polishing agents such as thermally sterilizable ion exchange resins and as a result, the need for chemical and/or mechanical microbial control or inhibition techniques is obviated. Therefore, the present invention will be especially useful in submarine and spacecraft applications where the need exists for reduced weight and volume water processing systems.
Abstract:
A process is disclosed wherein arsenic dissolved in wastewater or groundwater is removed from solution by precipitation thereof as calcium arsenate formed by the reaction of the arsenic with lime or hydrated lime in a heated solution at a pH of about 11 to about 13. It is preferred that the arsenic is first converted by oxidation to its pentavalent form.
Abstract:
An absorption process of using polydivinylbenzene to remove nerve agents h as GD from a conventional solvent such as chlorofluorocarbon which itself is used to decontaminate a surface such as armament.
Abstract:
A new process for removal of a metal ion from an anionic complex, including a first chelating agent and a metal ion, such as copper, nickel or cobalt ion, in electroless plating bath rinse streams utilizes a cation exchange resin to extract the metal ion from the rinse stream after the metal ion has been removed from the anionic complex and complexed with a second chelating agent.In another embodiment, a competing chelating agent is not added to the electroless plating bath waste stream, but rather, another metal ion (B), which has a higher affinity for the chelating agent than the metal ion (A) of interest and which is nontoxic, is added to the waste stream. Metal ion B is selected so that under predetermined conditions, metal ion B forms a stronger complex with the chelating agent than does metal ion A. Also, the complex of the chelating agent and nontoxic metal ion B is anionic. A cation exchange resin is used to extract metal ion A from the treated waste stream.
Abstract:
An apparatus for purifying blood has a blood compartment and a clearance compartment separated by a semi-permeable membrane. The apparatus includes a device containing a cation exchange resin charged with metal ions whose phosphates are insoluble in water. Metal salts of iron, aluminum, zirconium, lanthanum, thorium and tin are deposited on a cation exchange material and the charged cation exchange resin is contacted with dialysis liquid. The process of treating blood with the dialysis liquid is also contemplated.
Abstract:
A method of removing chromium ion from an aqueous solution of an organic acid of an acid concentration of up to 95% which comprises treating the solution with a cation exchange resin at a temperature higher than 55.degree. C.
Abstract:
A process for removing an organic impurity from an aqueous solution is disclosed, said process comprising contacting the aqueous solution with an acid cation exchanger and subsequently with a polymer or polycondensate, which contains sulfur in the form of thiol groups bonded to carbon atoms.
Abstract:
A method for the recycle treatment of chromium plating waste water, in the process of treating chromium plating waste water obtained by washing the chromium plated products with ion exchange resins, wherein, for the purposes of improving the rate of recovery of chromic acid, of extending the life of the ion exchange resins, and of preventing the formation of sludge, the chromium plating waste water is adjusted almost to neutrality by the addition of an alkaline substance so as to precipitate the metal components contained therein in the form of hydroxides, which are then removed by filtration; the filtrate so obtained is kept neutral during the subsequent treatment for the removal of alkaline components by adsorption in a pretreatment tower packed with cation exchange resins; the dilute dichromic acid solution so obtained is similarly treated for concentration in an adsorption tower packed with anion exchange resins and a purification tower packed with cation exchange resins so as to recover pure dichromic acid solution, whereas the above pretreatment tower and purification tower are regenerated by treatment with sulfuric acid.
Abstract:
Ca ion is removed by a cation exchange resin and silica and corrosive ions are removed by an anion exchange resin. Even after the anion exchange resin reaches the silica break through point or after the cation exchange resin reaches the Ca ion break through point, the supply of water is continued until the average of silica concentration or Ca ion concentration reaches a predetermined value. By supplying both treated water before the break through point and treated water after the break through point, water containing silica or Ca ion of suitable concentration can be supplied to the water system with only one anion exchange column or cation exchange column.