Concentrated aqueous bromine solutions and their preparation and use

a technology of concentrated aqueous bromine and solution, applied in the direction of biocide, water/sewage treatment by oxidation, specific water treatment objectives, etc., can solve the problems of inability to meet the requirements of commercial acceptance, cumbersome feeding and metering of two liquids, and undesirable reddish-colored vapors, etc., to achieve the effect of reducing ph, increasing the ph of the product solution, and simplifying the operation

Inactive Publication Date: 2005-07-07
MOORE ROBERT M JR +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The resulting solutions provide stable, high-concentration bromine-based biocides that maintain effective biocidal activity for extended periods, are non-corrosive and non-acidic, and are devoid of detectable bromate, enabling efficient microbiological control and biofilm eradication in water treatment systems.

Problems solved by technology

The feeding of the two liquids in this fashion is necessary because the HOBr / OBr⊖ mixture is unstable and has to be generated on-site just prior to its introduction to the water.
Furthermore, the feeding, and metering of two liquids is cumbersome, especially as the system has to be designed to allow time for the activation of bromide ion to occur.
Nevertheless, the solutions still possessed measurable vapor pressures, and thus tended to produce undesirable reddish-colored vapors during storage and use.
Unfortunately, the relatively high acidity of these solutions and their tendency to be corrosive and fuming impose limitations on their commercial acceptance.
Many solid bromine derivatives such as BCDMH (1,3-bromochloro-5,5-dimethylhydantoin) are limited in the amount of material that can be dissolved in water and fed as a liquid to the water treatment system.
Another limitation of such derivatives is that at neutral pH, HOBr rapidly decomposes, eventually forming bromide ions.
Thus, the ability to store and transport these aqueous solutions is greatly limited and of questionable commercial feasibility.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

Bromine Chloride, Caustic and Sodium Sulfamate at Neutral pH

[0084] A 1 liter flask was charged with 52.0 g of sulfamic acid and 250 g of water. Sodium sulfamate was prepared by adding 60.0 g of 50% sodium hydroxide to the stirred slurry. Bromine chloride was prepared by adding 20 g of chlorine to 47.0 g of bromine. This bromine chloride was then co-fed with 210 g of 25% sodium hydroxide to maintain the pH between 6 and 8. 5 mL of 1 M hydrochloric acid were added to bring the final pH to approximately 7±0.5. The solution, which contained some solids, was transferred to an amber bottle for storage. Starch-iodine titration of a sample of the solution indicated that it had an active bromine concentration of 11.2%.

example 2

Bromine Chloride, Caustic and Sodium Sulfamate

[0085] A 1 liter flask was charged with 107 g of sulfamic acid and 200 g of water. Sodium sulfamate was prepared by adding 93.9 g of 50% sodium hydroxide to the stirred slurry. Bromine chloride was prepared by adding 39 g of chlorine to 96.0 g of bromine. This bromine chloride was the co-fed with 319 g of 50% sodium hydroxide to maintain the pH between 11 and 13. After stirring for an additional 30 minutes, the solution, which contained some solids, was transferred to an amber bottle for storage. Starch-iodine titration of a sample of the solution indicated that it had an active bromine concentration of 18.0%. Analysis of the solution after three weeks at ambient temperature indicated that the solution still contained more than 90% of its active bromine content.

example 3

Bromine Chloride, Caustic and Sodium Sulfamate; Larger Scale

[0086] A 5 liter flask was charged with 470 g of sulfamic acid and 900 g of water. Sodium sulfamate was prepared by adding 436 g of 50% sodium hydroxide to the stirred slurry. Bromine chloride was prepared by adding 120 g of chlorine to 276 g of bromine. This bromine chloride was then co-fed with 1723 g of 50% sodium hydroxide to maintain the pH between 12 and 13. After stirring for an additional 60 minutes, the orange, clear solution was transferred to an polyethylene bottle for storage. Starch-iodine titration of a sample of the solution indicated that it had an active bromine concentration of 17.6%.

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Abstract

Described is a process of producing a concentrated liquid biocide formulation. Mixed together are (a) bromine chloride or bromine and (b) an aqueous solution of alkali metal salt of sulfamic acid having a pH of at least about 7, in amounts such that (i) the active bromine content of the solution is at least about 100,000 ppm (wt / wt), and (ii) the atom ratio of nitrogen to active bromine from (a) and (b) is greater than 1 when bromine is used and is greater than 0.93 when bromine chloride is used. Use of bromine chloride as the source of the active bromine in the process is preferred because in the resulting aqueous compositions, all of the bromine of the bromine chloride is made available as active bromine in solution. In other words, the chlorine of the bromine chloride is converted in the process to dissolved alkali metal chloride salt, thereby liberating all of the bromine in the biocidal composition as active bromine capable of providing biocidal activity.

Description

REFERENCE TO RELATED APPLICATION [0001] This is a Division of U.S. application Ser. No. 09 / 974,622, filed Oct. 9, 2001, which is a continuation-in-part of commonly-owned U.S. application Ser. No. 09 / 404,184, filed Sep. 24, 1999, now U.S. Pat. No. 6,322,822, issued Nov. 27, 2001, and Ser. No. 09 / 506,911, filed Feb. 18, 2000, now U.S. Pat. No. 6,511,682, issued Jan. 28, 2003, both of which are continuations-in-part of commonly-owned U.S. application Ser. No. 09 / 088,300, filed Jun. 1, 1998, and its Continued Prosecution Application (CPA) No. 09 / 088,300, now U.S. Pat. No. 6,068,861, issued May 30, 2000. Said application Ser. No. 09 / 506,911, (now U.S. Pat. No. 6,511,682, issued Jan. 28, 2003) is also a continuation-in-part of said application Ser. No. 09 / 404,184 (now U.S. Pat. No. 6,322,822, issued Nov. 27, 2001). REFERENCE TO OTHER COMMONLY-OWNED APPLICATIONS [0002] Reference is also made to commonly-owned 09 / 442,025, filed Nov. 17, 1999, now U.S. Pat. No. 6,306,441, issued Oct. 23, 200...

Claims

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Application Information

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Patent Type & AuthorityApplications(United States)
IPC IPC(8): A01N59/00C02F1/76
CPCA01N59/00C02F1/766C02F2303/04A01N2300/00
InventorMOORE, ROBERT M. JR.NALEPA, CHRISTOPHER J.
OwnerMOORE ROBERT M JR