MXPA00010495A - Stable oxidizing bromine formulations, methods of manufacture thereof and methods of use for microbiofouling control - Google Patents

Abstract

Stable oxidizing biocide formulations containing bromine are provided for biofouling control in industrial water systems. The formulations contain at least one stable oxidizing bromine compound that is prepared from at least one oxidizing chemical reagent, at least one bromine source and at least one bromine or halogen stabilizer. The resulting products are a mixture of stable oxidizing bromine compounds that can be used as a primary or secondary biocide in an industrial water system.

Description

STABLE FORMULATIONS OF OXIDIZING BROMO, METHODS FOR THE ELABORATION OF THESE, AND METHODS OF USE FOR THE CONTROL OF THE MICROBIOINCRUSTATION) BACKGROUND OF THE INVENTION The present invention relates to formulations for the control of biofouling in industrial water systems. More specifically, the present invention relates to methods for preparing stable oxidative bromine formulations and their use in the control of biofouling of industrial water systems. It is known that ozone is an effective biocide that is used to control biofouling in various industrial water applications. However, ozone is also very reactive with other chemicals for water treatment such as corrosion inhibitors and scale inhibitors. As a result, it is difficult to maintain a residual concentration of ozone in a system and therefore substantially reduce the effectiveness of ozone as a biocide. Ref: 124404 In an effort to overcome ozone deficiencies, the combination of ozone and bromine has been used. One method uses ozone-activated hypobromite to increase the initial concentration of the biocide in the system and reduce the reaction of ozone with other chemicals for water treatment. However, bromine types such as OBr ~, HOBr and Br2 are produced and all are unstable and aggressive against chemicals for water treatment as well. Methods for generating stabilized hypobromite to be used at levels below 100 ppm as a secondary disinfectant for water ozonation are also known. The ozonation processes are carried out at a pH of about 8.5. The compounds that are used to stabilize the hypobromite include 5, 5-dimethylidantoin and succinamide. Therefore, while bromine compounds such as hypobromite have been used as secondary disinfectants or have been generated for use in place without concern for bromine stabilization, to date, there has only been one successful method for provide bromine oxidant formulations that are stable and can be used for the control of biofouling. Therefore, methods to generate higher concentrations of stable oxidative bromine formulations in a more secure manner are needed so that these stable bromine oxidant formulations can be combined with ozone and can be an effective biofouling system.

Brief Description of the Invention The present invention meets the aforementioned needs by providing a method for generating a stable bromine oxidant compound and an aqueous biocidal solution containing a stable bromine oxidant formulation. The method of the present invention can be used to generate stable bromine oxidant compounds and aqueous solutions containing stable bromine oxidant compounds for use in the control of biofouling in industrial water systems. In one embodiment, the method of the present invention for generating at least one stable bromine oxidant compound in an aqueous solution includes the steps of providing a solution comprising a bromo alkali or alkaline earth metal and a halogen stabilizer selected from from the group consisting of R-NH2, R-NH-R1, R-S02-NH2 ,. R-S02-NHR1, R- = CO-NH2, R-CO-NH-R1 and R-CO-NH-CO-R1 wherein R is a hydroxyl group, an alkyl group or an aromatic group and R1 is a group alkyl or an aromatic group, followed by the step of adjusting the solution to a pH ranging from 4 to 8, followed by the step of adding an oxidizing agent to the solution. In one embodiment, the method further includes adjusting the solution to a temperature ranging from about 0 ° to about 60 ° C, preferably from about 4 ° C to about 21 ° C, after the oxidizing agent is added to the solution . In a modality, the method of the present invention further includes the step of adjusting the pH of the solution to a range of more than 13 after the oxidizing agent is added to the solution. In one embodiment, the oxidizing agent is ozone. In one embodiment, bromine alkali, the alkaline earth metal is NaBr. In one embodiment, the step of adjusting the pH of the solution before addition of the oxidizing agent further comprises adjusting the pH to a level of about 7. In one embodiment, the present invention is a method for treating an industrial water system with a stable bromine oxidant compound. The method includes the steps of providing a container, providing a solution comprising a bromo alkali or bromo of alkaline earth metal and a halogen stabilizer selected from the group consisting of R-NH2, R-NH-R1, R- S02-NH2, R-SO? -NHR1, R-CO-NH2, R-CO-NH-R1 and R-CO-NH-CO-R1 wherein R is a hydroxyl group, an alkyl group or an aromatic group and R1 is an alkyl group or an aromatic group, followed by the passage of the pH of a solution to a range of from 4 to about 8, followed by the step of injecting a gaseous oxidizing agent into the solution to produce the stable bromine-oxidizing compounds, followed by the step of adding the solution to an industrial water system for the control of biofouling. In one embodiment, the method of the present invention further includes the step of adding a gaseous oxidizing agent to the counter-current industrial water system at a point where the stable bromine-oxidizing compound is added to the system.

In one embodiment, the present invention provides a method for treating the industrial water system as a primary biocide and a secondary biocide for the control of biofouling. The method includes the steps of providing a solution in a first container, the solution comprising a bromoalkali or an alkaline earth metal bromine and a halogen stabilizer selected from the group consisting of R-NH2, R-NH-R1 , R-S02-NH2, R-S02-NHR1, R-CO-NH2, R-CO-NH-R1 and R-CO-NH-CO-R1 wherein R is a hydroxyl group, an alkyl group or a group aromatic and R1 is an alkyl group or an aromatic group, the solution further has a pH ranging from about 4 to about 8, followed by the step of adding a gaseous oxidizing agent to the solution in the first container, and at least one part of the gaseous oxidizing agent reacts with the bromoalkali or the alkaline earth metal bromine and wherein at least this gaseous oxidant has not reacted with the bromoalkali or the alkaline earth metal bromine and the halogen stabilizer to serve as a supply of an unreacted gaseous oxidizing agent, followed by the step of adding the unreacted gaseous oxidizing agent to the industrial water system as a primary biocide, followed by the step of adding the stable oxidizing bromine compounds to the industrial water system as the secondary biocide. In one embodiment, the method further comprises the steps of transferring the solution to a second container and then increasing the pH of the solution to a level greater than 13 in order to stabilize the hypobromite solution and thereby extend its shelf life and thus both allow the operator to add the solution to the industrial water system on a "needy basis." In one embodiment, the method of the present invention provides a method for generating at least one stable bromine oxidant compound, the method includes the steps of providing a solution comprising a bromoalkali or an alkaline earth metal bromine and a halogen stabilizer selected from the group consisting of at least one sulfanate and a sulfonamide, followed by the step of adjusting the pH of the solution to a range from 4 to 8, and followed by the step of adding an oxidizing agent to the solution selected from the group consisting of ozone, perox gone from hydrogen and peracetic acid.

Therefore, it is an advantage of the present invention to generate a stable solution of bromine oxidant in a safe and efficient manner where no bromine gas formations are generated. It is another advantage of the present invention to generate the stable bromine oxidant compounds in a limited number of steps without the need for a separate step for the generation of the hypobromite. Another advantage of the present invention is that it provides a stable bromine oxidant compound in a high concentration without the direct use of a concentrated form of unstabilized bromine. Yet another advantage of the present invention is that it provides a method for generating the stable bromine oxidant compounds without unwanted byproducts such as high levels of bromate. Yet another advantage of the present invention is that the method of the present invention does not generate chloride and therefore the method of the present invention generates the stable formulations of bromine oxidant which are less corrosive. Yet another advantage of the present invention is that it provides stable oxidizing bromine compounds that are safer to transport.

Even another advantage of the present invention is that it generates very little bromate. Yet another advantage of the present invention is that it generates stable oxidizing bromine compounds for the control of biofouling which are more compatible with other chemicals for water treatment. And yet another advantage of the present invention is that the stable compound The bromine oxidant provided can be used as either a single agent for biofouling control or as a secondary agent for the control of biofouling. Another advantage of the present invention is that it provides an improved method for the control of microbioincrustation in pulp and paper processing systems. Another advantage of the present invention is that it provides an improved method for controlling biofouling in a system for food processing. Yet another advantage of the present invention is that it provides improved control of the microbioincrustation of a system for the processing of beverages.

Yet another advantage of the present invention is that it provides improved control of microbioincrustation in a system for recreational waters. And another advantage of the present invention is that it provides an improved method for disinfecting a hard surface. Other objects and advantages of the present invention will be apparent upon review of the following detailed description and the following appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 schematically illustrates an apparatus for generating the stable oxidizing bromine compounds for use in an industrial water system.

Detailed Description of the Presently Preferred Modes The present invention provides a variety of formulations and methods for generating a broad concentration of stable bromine oxidant compounds which can be used as primary and secondary agents for the control of biofouling for the cooling of waters and other systems. industrial While ozone is discussed as an exemplary oxidizing agent for the methods described herein, it is noted that other oxidizing agents such as peroxides, peracetic acid and other peroxygen compounds can also be used as an oxidizing agent or as an oxidizing agent. primary. When ozone is used as an oxidizing agent, the products of the stable oxidizing bromine compounds are formed by directly ozonizing a mixture of a solution of sodium bromide, sodium sulfonate (or other primary or secondary amines, or amides that are stable). in an ozone environment) at an optimum pH range. In the formulation, ozone serves as the oxidizing agent, the bromide salts as the bromine source and the sulfanate as the oxidizing bromine stabilizer. In the pre-ozonation solution, bromide and sulfanate are added in equal equimolar amounts. The pH of the solution is adjusted by the addition of a caustic agent (sodium hydroxide) or acid. The optimum pH of the solution for the process ranges from 4 to 8.

Without being limited by theory, the reaction mechanism is believed to be the following sequential chemical reactions: Br "+ 03? BrO" (1) BrO "+ -S03NH2? -S03NHBr, -S03NBr2 and other bromine oxidant compounds (2) The second reaction begins as soon as the trace amounts of the hypobromite are generated in the first reaction. It is known that unstabilized hypobromite is very corrosive and more volatile than stable hypobromite. The stabilization process itself if described here minimizes the loss of the hypobromite through chemical decomposition and physical evaporation. In addition, one of the main byproducts of the decomposition of the hypobromite is bromate. It has been confirmed that the practices of the methods in accordance with the present invention do not produce a detectable bromate (or less than 50 ppm of bromate in 5.2% of the stable product of hypobromite). As a result, a greater ozonation efficiency is achieved when the stabilizer is added compared to the conventional conversion of the bromide ozone. In addition, no significant loss of bromine occurs with the addition of the stabilizer after long-term ozonization of up to 30 hours. In addition, sulfanate is not degraded by ozone. The step of lowering the pH to a range from 4 to 8 before oxidation is important. At pH levels of more than 8, the OH radicals that form are much more reactive and less discriminating than ozone. As a result, at pH levels greater than 8, the OH radicals that form from the ozonation process react with the sulfanate with the stable bromine oxidant compounds that result in the formation of non-stable bromine oxidant compounds. Table 1 illustrates the dependence of the stable bromine oxidant compounds and their formation on the reaction pH and the concentration of the product with the ozonation time. Table 2 illustrates the relationship between stable bromine oxidant formation and ozonation time. As shown in Table 1, no stable oxidizing compound is formed until the reaction pH decreases to less than 8. This phenomenon was not previously known.

Table 1. Activation by ozone and stabilization in itself of the oxidizing bromine Table 2. Formation of stable oxidizing bromine compounds by ozonation Time of Concentration of the Product Ozonization (hr) (% as Cl) 1 1.703a 2 2.912a Concentration quantified by the titration Kl-dpd. Concentration quantified by the titration of Kl-thiosulfate.

Although a low pH (4-8) is optimal for the formation of the product when ozone is used as the oxidizing agent, the thermal stability of the stable oxidizing bromines decreases while the pH also decreases. As a result, it is important to maintain a high reaction pH and a low reaction temperature (optimally 4 ° C to 21 ° C) and after that adjust the pH of the product to a level greater than 13 once the process has been completed. . These additional steps ensure the long-term stability of the product since it is believed that the product undergoes a decomposition at elevated temperatures and / a low pH according to the following reaction: HS03NH-Br, HS03NBr2, and other stable oxidant bromines - > N2 + S042"+ Br" (3) In one embodiment, a direct field of the process for the generation in si t u of stable oxidizing bromine compounds. Again, ozone is used as an oxidizing agent since it is used expressly in field operations. Ozonizers as shown in 11 in Figure 1 are found in many application sites. The ozone is supplied from the generator 11 through the reactor 12 and is injected into the system 13 through a conduit 14 as a primary biocide. The reaction container 12 already includes a solution of alkali metal bromo alkali or bromine, a halogen stabilizer which can be sulfamate and a pH ranging from 4 to 8. The ozone can be recycled back into the reactor 12 to through the return line 15. The ozonation time required for the total conversion can be predetermined or quantified by a color wheel since the available concentration of halogen is linearly correlated with the absorption of light from 400 to 600 nm, preference is quantified at 460 nm. The stable bromine oxidant compounds can then be transferred from the reactor 12 to the storage container 16 where it can be added to the water flow 13 via the valve 17 on a "while needed" basis.

Example I By way of example, a synthesis of the stable oxidizing bromide compound can be carried out as follows. 14.4 g of 50% aqueous NaOH, 17.47 g of sulfanic acid, 41.4 g of 45% aqueous sodium bromide and 26.99 g of water are mixed in a 250 ml graduated cylinder. The pH of the solution is approximately 7.0. Ozonation is carried out by passing ozone gas bubbles through a porous glass that extends to the bottom of the cylinder. A PCI ozonator (Model GL-1, maximum ozone output: 454 g / day) is used for the generation of ozone and operates at 75% of the output capacity with approximately half the gas flow going to the cylinder. After a period of 7 hours of ozonation, the pH of the solution is quantified at 5.6.

Then, sodium hydroxide is added slowly to the solution to raise the pH to 13.3. The final volume of the solution is approximately 60 ml. The available concentration of halogen is determined as 12.85% as Br2 by titration of potassium iodide thiosulfate.

Example II By way of another example, 7.24 g of 50% aqueous NaOH, 8.75 g of sulfanic acid, 20.68 g of 45% aqueous sodium bromide and 63.31 g of water are combined in a 250 ml graduated cylinder. The pH of the solution is adjusted to 7 by the dropwise addition of an additional solution of sodium hydroxide. Ozonation is carried out by passing ozone in bubbles through a porous glass that extends to the bottom of the cylinder using a PCI ozinizer that operates at 15% output capacity. After a period of 10 hours of ozonation, the total concentration of the residual oxidant of the resulting solution is determined by the titration of potassium iodide thiosulfate as 14.38% as Br2. It is estimated that more than 98% of the bromide is converted and the general ozonization requirement for the total time duration is estimated at 28.5%. Table 2 shows that the concentration of the product increases with the ozonation time.

Example III By way of another Example, by using the apparatus illustrated in Figure 1 for a 378,541.2 liter water cooling system, an ozonizer of 1.814 g / day is used. The ozone generated from the ozonator is introduced into the interior of a reactor 12 by means of a diffuser (not shown). The 5 liter reactor 12 is filled with a mixture of 389 g of NaBr, 440 g of sulfamic acid, 302 g of 50% aqueous NaOH and 2 liters of water. The pH of the mixture is adjusted to either NaOH or HCl. The unreacted ozone is collected in the upper part of the reactor 12 and introduced into the water flow 13 as the primary biocide. For a continuous period of 24 hours of ozonation and an ozonation efficiency of 10% and a bromine conversion of 100%, 268 g (as Cl2) of stable bromine oxidant is generated in reactor 12. The product generated is then it pumps into the flow of the water cooling system 13 either directly from the reactor 12 or in the manner of a storage container 16. The stable generated bromine oxidant compounds provide the water cooling system with a reasonable amount with a total residue of halogen (from 0.1 to 0.7 ppm as available chlorine) that serves as a secondary biocide. If continuous dosing of the stable bromine oxidant compounds is required, a second reactor 16 can be used for ozonation while the product of the first reactor is injected into the water flow 13 and via the valve 18. The method of the present invention invention can be used to provide improved control of microbioincrustation in pulp and paper processing systems, food and beverage processing system, recreational water systems, and the method of the present invention can be used in a manner of a method to disinfect a hard surface. Food processing includes, but is not limited to, adding the present invention to an aqueous medium that is used to transport the food through various processing steps and also in the equipment for the disinfection process and in water currents. residuals It is to be understood that various changes and modifications to the presently preferred embodiments described herein are apparent to those skilled in the art. These changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. It is therefore intended that these changes and modifications be covered by the appended claims.

It is noted that in relation to this date, the best known method for the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects or products to which it refers.

Claims (30)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. A method for generating at least one stable bromine oxidant compound, characterized in that the method comprises the following steps: providing a solution comprising a bromoalkali or an alkaline earth metal bromine and a halogen stabilizer selected from the group consists of R-NH2, R-NH-R1, R-S02-NH2, R-S02-NHR1, R-CO-NH2, R-CO-NH-R1 and R-CO-NH-CO-R1 wherein R is a hydroxyl group, an alkyl group or an aromatic group and R1 is an alkyl group or an aromatic group, adjust the solution to a pH ranging from about 4 to about 8, add an oxidizing agent to the solution.

2. The method according to claim 1, characterized in that the oxidizing agent is selected from the group consisting of ozone, peracetic acid, hydrogen peroxide and oxidizing bromine compounds.

3. The method according to claim 1, characterized in that the bromoalkali or the alkaline earth metal bromine is NaBr.

4. The method according to claim 1, characterized in that it further comprises the following step in addition to the step of adding an oxidizing agent: adjusting the solution to a temperature ranging from about 0 ° to about 60 ° C.

5. The method according to claim 1, characterized in that it also comprises the following step after adding the step of an oxidizing agent: adjust the pH of the solution to a range greater than 13.

6. The method according to claim 1, characterized in that the halogen stabilizer is sulfamate.

7. The method according to claim 1, characterized in that the step of adjusting the solution ^ Mltt further includes adjusting the pH to a level of approximately 7.

8. The method of treating an industrial water system with the stable oxidizing bromine compounds, characterized in that the method comprises the following steps: in a container, provide a solution comprising a bromo alkali or an alkaline earth metal bromine and a stabilizer halogen selected from the group consisting of R-NH2, R-NH-R1, R-S02-NH2, R-SO? -NHR1, R-CO-NH2, R-CO-NH-R1 and R-CO- NH-CO-R1 wherein R is a hydroxyl group, an alkyl group or an aromatic group and R1 is an alkyl group or an aromatic group, adjusting the solution to a pH ranging from about 4 to about 8, injecting an oxidizing agent gaseous in the solution to produce the stable compounds of bromine oxidant, add the solution to the system of industrial waters.

9. The method according to claim 8, characterized in that the bromoalkali or the alkaline earth metal bromine is NaBr.

10. The method according to claim 8, characterized in that the halogen stabilizer is sulfamate.

11. The method according to claim 8, characterized in that the step of adjusting the pH comprises adjusting the pH to a level of about 7.

12. The method according to claim 8, characterized in that it further comprises the following step before the step of adding the gaseous oxidizing agent: adjusting a temperature of the solution to a range from about 0 ° C to about 60 ° C.

13. The method according to claim 8, further comprising the step of adding a gaseous oxidizing agent to the counterflow industrial water system wherein the stable bromine-oxidizing compound is added to the system.

14. The method according to claim 8, characterized in that it further comprises the next step after the step of adding the gaseous oxidizing agent: increasing the pH of the solution to a level greater than 13.

15. A method to treat an industrial water system with a primary biocide and a secondary biocide, characterized in that the method comprises the following steps: in a first container, providing a solution comprising a bromoalkali or an alkaline earth metal bromine and a halogen stabilizer selected from the group consisting of R-NH2, R- NH-R1, R-S02-NH2, R-SO? -NHR1, R-CO-NH2, R-CO-NH-R1 and R-CO-NH-CO-R1 wherein R is a hydroxyl group, a group alkyl or an aromatic group and R 1 is an alkyl group or an aromatic group, the solution further has a pH ranging from about 4 to about 8, adding an oxidizing agent to the solution in the first container, at least a part of the agent gaseous oxidant reacts with the bromoalkali or the alkaline earth metal bromine and the halogen stabilizer to produce the stable bromine oxidant compounds and wherein at least a part of the gaseous oxidizing agent does not react with the bromoalkali or the bromo alkaline earth metal and halogen stabilizer and whereby a supply of the unreacted gaseous oxidant is provided, adding the unreacted gaseous oxidizing agent to the industrial water system as a primary biocide, adding the stable bromine oxidant compounds to the industrial water system as a secondary biocide.

16. The method according to claim 15, characterized in that the bromoalkali or the alkali earth metal bromine is NaBr.

17. The method according to claim 15, characterized in that the gaseous oxidizing agent is ozone.

18. The method according to claim 15, characterized in that the first container is maintained at a temperature ranging from about 0 ° C to about 60 ° C.

19. The method according to claim 15, characterized in that the pH of the solution is maintained at a level of about 7.

20. The method according to claim 15, characterized in that the halogen stabilizer is sulfamate.

21. The method according to claim 15, characterized in that it also comprises the following steps after the step of adding the unreacted gaseous oxidizing agent and before the step of applying the stable generated solution of the bromine oxidant to the industrial water system: adjusting the solution to a pH of more than 13.

22. The method according to claim 15, characterized in that it also comprises the following steps after the step of adding the unreacted gaseous oxidizing agent and before the step of applying the stable generated solution of bromine oxidant to the industrial water system: transfer the solution to a second container, increase the pH of the solution to a level higher than 13.

23. A method for generating at least one stable bromine oxidant compound, characterized in that the method comprises the following steps: providing a solution comprising a bromoalkali or an alkaline earth metal bromine and a halogen stabilizer selected from the group consists of at least one sulfamate and a sulfonamide, adjusting the solution to a pH ranging from about 4 to about 8, adding an oxidizing agent to the solution selected from the group consisting of ozone, hydrogen peroxide and peracetic acid, adjust the pH of the solution to a range greater than 13.

24. A stable bromine oxidant compound characterized in that it is prepared by the following steps: providing a solution comprising a bromoalkali or an alkaline earth metal bromine and a halogen stabilizer selected from the group consisting of R-NH2, R- NH-R1, R-S02-NH2, R-S02-NHR1, R-C0-NH2, R-CO-NH-R1 and R-CO-NH-CO-R1 wherein R is a hydroxyl group, an alkyl group or an aromatic group and R 1 is an alkyl group or an aromatic group, adjusting the solution to a pH ranging from about 4 to about 8, adding an oxidizing agent to the solution.

25. A method for controlling microbioincrustation in a wastewater system wherein an oxidizing agent is added to control the micro-fouling, characterized in that the method comprises using the oxidizing bromo stable compound according to claim 24 as the oxidizing agent.

26. A method for the control of the microbioincrustation in the pulp and the paper processing system in which an oxidizing agent is added to control the microbioincrustation, characterized in that the method comprises using the oxidizing agent as the oxidizing bromine compound in accordance with the with claim 24.

27. A method for the control of microbioincrustation in a food processing system wherein an oxidizing agent is added to control the microbioincrustation, characterized in that the method comprises using as an oxidizing agent the brominated oxidant stable compound, in accordance with the claim 24

28. A method for the control of microbioincrustation in a system for the processing of beverages wherein an oxidizing agent is added to control the microbioincrustation, characterized in that the method comprises using as an oxidizing agent the stable bromine oxidant compound, in accordance with claim 24.

29. A method for the control of microbioincrustation in a recreational water system wherein an oxidizing agent is added to control the microbioincrustation, characterized in that the method comprises using as an oxidizing agent the stable bromine oxidant compound, in accordance with the claim 24

30. A method for disinfecting a hard surface in which an oxidizing agent is added to disinfect the hard surface, characterized in that the method comprises using the stable oxidizing bromine compound in the manner of the oxidizing agent, according to claim 24.