Abstract:
The present invention relates to a process for producing pure water having a total organic carbon content of not more than 200 ppb instantly after start of the operation of a high purity water system, comprising using as an ion exchange resin a specific strongly basic anion exchange resin and passing raw water through the high purity water system at a space velocity of not less than 20. The produced pure water is capable of producing tasteless and odorless pure water instantly after start of the operation of the high purity water system.
Abstract:
Aqueous solutions of an amine N-oxide such as N-methyl morpholine N-oxide used in the manufacture of regenerated cellulose can be purified by passage through a strongly basic anion-exchange resin. The resin is regenerated by treatment with (1) an aqueous solution of a strong inorganic acid such as hydrochloric or sulphuric acid and (2) an aqueous solution of sodium hydroxide.
Abstract:
The invention provides a method for preparing polyhalide resin disinfectants. The step of the method involves circulating an effective amount of a polyhalide salt carrier solution between an effective amount of elemental halide and a strong base anion exchange resin until substantially all of the resin is converted to the polyhalide form. The elemental halide and the resin are separately disposed but connected so that the polyhalide salt carrier solution can be recirculated until all of the elemental halide is transferred to the resin. The method of the invention can be used to form a tri-iodide or penta-iodide resin, or mixed form of the resin including IBr.sub.2.sup.-/I.sub.2.sup.-.
Abstract:
The present invention provides a process for removing heat stable salts which accumulate in alkanolamine gas purification process units. Surprisingly, it has been found that weakly acidic cationic exchange resins are dramatically more effective for removing heat stable salts from alkanolamine solutions than strongly acidic cationic exchange resins.Specifically, it has been found in accordance with the invention that ion exchange resins are useful for purifying used aqueous alkanolamine solutions, in the following order of preference: Weak Acid IX>Weak Base IX>Strong Acid IX>Strong Base IX.
Abstract:
A method and apparatus are disclosed for maintaining continuous, long-term microbial control in the water supply for potable, hygiene, and experimental water for space activities, i.e., space shuttle, orbiter lab, Lunar base, Mars base, deep space missions, etc., as well as treatment of water supplies on earth. The water purification is accomplished by introduction of molecular iodine into the water supply to impart a desired iodine residual. The water is passed through an iodinated anion exchange resin bed. The iodine is bound as I.sup.-.sub.n at the anion exchange sites and releases I.sub.2 into the water stream flowing through the bed. Suitable anion exchange resins are Amberlite IRA 401S (Rohm & Haas); Dowex SBR (Dow Chemical); and Ionac ASB-1P (Sybron Corp.). The concentration of I.sub.2 in the flowing water gradually decreases and the ion-exchange bed has had to be replaced. In a preferred embodiment, a bed of iodine crystals is provided with connections for flowing water therethrough to produce a concentrated (substantially saturated) aqueous iodine solution which is passed through the iodinated resin bed to recharge the bed with bound iodine. The iodinated resin bed has been recharged up to eight times during continuous use to permit an extended life to the system. The bed of iodine crystals is connected in parallel with the iodinated resin bed and is activated periodically, e.g., by timer, by measured flow of water, or by iodine residual level, to recharge the bed.
Abstract:
The present invention relates to a method of reducing the concentration of contaminant ions, preferably nitrates ions, in impure water. The method comprises steps of: a) passing the impure water through an ion exchange resin to substitute regenerant ions from the resin for dissolved contaminant ions; b) passing a relatively dilute aqueous solution of wash-out ions through said resin to substitute wash-out ions for contaminant ions bound to the resin and; c) passing a relatively concentrated aqueous solution of regenerant ions through said resin to substitute regenerant ions for wash-out ions bound to the resin. The affinity of the resin to wash-out ions diminishes from being greater than that for contaminant and regenerant ions when exposed to a relatively dilute ionic solution to being less than that for said contaminant and regenerant ions when exposed to a relatively concentrated ionic solution. The method allows simplified ion exchange apparatus to be utilized, since the raw water, wash-out solution and regenerant solution may all be passed through the ion exchange resin in the same direction.
Abstract:
This invention relates to a process for treating waste solutions and rinse waters, especially those from electroless plating processes to remove organometallic complexes and complexing agents, particularly copper and copper-EDTA complexes by eluting the waste solutions through anionic exchange resins.
Abstract:
Novel strongly basic anion-exchange resins substantially loaded with controlled relative proportions of iodide-bromide polyhalides whereby, when water is passed therethrough which is contaminated with bacteria, potable drinkable water is obtained for safe and effective usage in public water supply systems for relatively prolonged periods of time.
Abstract:
Spent aqueous liquor containing cyanide, as from ore treatment, is passed through a bed of suitable anion-exchange resin to segregate the cyanide, which is subsequently recovered in regeneration of the resin by weak alkaline solution. Both the eluted cyanide and the alkaline regenerant are recycled, if desired, for further ore treatment. A most important benefit of such procedure is nearly complete elimination of cyanide as a component of the treatment effluent. Free cyanide may be separated from complexed cyanides when present by using weak alkaline regenerant to elute the free cyanide from the resin and stronger alkaline regenerant to elute the complexed cyanides.
Abstract:
Ozone is dispersed in river water to be purified and used in a high pressure boiler. The ozone selectively degrades large organic molecules, dissolved in the water, which ordinarily will irreversibly foul the strongly basic anion attracting resin used to adsorb silicious contaminants from the water. The degraded molecules are reduced in resin-fouling capability and are removed from the resin during regeneration.