Claims
- 1. A composition for inhibiting the growth of microorganisms in aqueous systems comprising effective amounts of peracetic acid and a non-oxidizing biocide selected from the group consisting of: decylthioethylamine, orthophthaldehyde, dodecylguanidine hydrochloride, 1-(3-chloroallyl)-3,5,7-triaza-1-azoniaadamantane chloride, dibromo dicyanobutane and bis(trichloromethyl)sulfone, said amount of peracetic acid and non-oxidizing biocide being selected to result in a synergy index of less than 1 wherein said synergy index is calculated by determining a first ratio of the amount of peracetic acid required to produce a level of microorganism growth inhibition when added in combination with the amount of non-oxidizing biocide to the amount of peracetic acid required to produce the level of growth inhibition in the absence of the non-oxidizing biocide, and adding the first ratio to a second ratio of the amount of non-oxidizing biocide required to produce the level of growth inhibition when added in combination with the amount of peracetic acid to the amount of non-oxidizing biocide required to produce the level of growth inhibition in the absence of the peracetic acid.
- 2. The composition of claim 1 wherein the amount of peracetic acid ranges from approximately 5 to 250 ppm and the amount of non-oxidizing biocide ranges from approximately 10 to 250 ppm.
- 3. A method for controlling the growth of microorganisms in industrial process water including the step of administering a sufficient amount of a peracetic acid and a sufficient amount of a non-oxidizing biocide to the industrial process water to inhibit the growth of the microorganisms, said non-oxidizing biocide selected from the group consisting of decylthioethylamine, orthophthaldehyde, dodecylguanidine hydrochloride, 1-(3-chloroallyl)-3,5,7-triaza-1-azoniaadamantane chloride, dibromo dicyanobutane and bis(trichloromethyl)sulfone, said non-oxidizing biocide being selected to result in a synergy index of less than 1 wherein said synergy index is calculated by determining a first ratio of the amount of peracetic acid required to produce a level of microorganism growth inhibition when added in combination with the amount of non-oxidizing biocide to the amount of peracetic acid required to produce the level of growth inhibition in the absence of the non-oxidizing biocide, and adding the first ratio to a second ratio of the amount of non-oxidizing biocide required to produce the level of growth inhibition when added in combination with the amount of peracetic acid to the amount of non-oxidizing biocide required to produce the level of growth inhibition in the absence of the peracetic acid.
- 4. The method of claim 3 wherein the industrial process water is selected from the group consisting of water of a pulp and paper mill system, cooling water and mining.
- 5. The method of claim 3 wherein the peracetic acid and the non-oxidizing biocide are added in a ratio from about 10:1 to 1:25.
- 6. The method of claim 3 wherein the amount of peracetic acid added ranges from approximately 5 to 250 ppm and the non-oxidizing biocide ranges from approximately 10 to 250 ppm.
- 7. The method of claim 3 wherein the microorganisms contain bacteria.
- 8. The method of claim 3 wherein the microorganisms contain fungi.
- 9. The method of claim 3 wherein the peracetic acid is added to the industrial water prior to the addition of the non-oxidizing biocide.
BACKGROUND OF THE INVENTION
1. Reference to Related Patent
The present application is a continuation-in-part of application Ser. No.08/350,570, filed Dec. 7, 1994, by Judy G. LaZonby, entitled "Method and Composition For Inhibiting Growth of Microorganisms Including Peracetic Acid and a Non-Oxidizing Biocide", now U.S. Pat. No. 5,494,588, which is in turn a continuation-in-part of application Ser. No. 08/102,286, filed Aug. 5, 1993, by Judy G. LaZonby, entitled "Method and Composition for Inhibiting Growth of Microorganisms Including Peracetic Acid and a Non-Oxidizing Biocide", now abandoned, the disclosures of which are incorporated herein by reference.
US Referenced Citations (4)
Continuation in Parts (2)
|
Number |
Date |
Country |
Parent |
350570 |
Dec 1994 |
|
Parent |
102286 |
Aug 1993 |
|