System and method for generation of point of use reactive oxygen species
Systems and methods for generating reactive oxygen species formulations useful in various oxidation applications. Exemplary formulations include singlet oxygen or superoxide and can also contain hydroxyl radicals or hydroperoxy radicals, among others. Formulations can contain other reactive species, including other radicals. Exemplary formulations containing peracids are activated to generate singlet oxygen. Exemplary formulations include those containing a mixture of superoxide and hydrogen peroxide. Exemplary formulations include those in which one or more components of the formulation are generated electrochemically. Formulations of the invention containing reactive oxygen species can be further activated to generate reactive oxygen species using activation chosen from a Fenton or Fenton-like catalyst, ultrasound, ultraviolet radiation or thermal activation. Exemplary applications of the formulations of the invention among others include: cleaning in place applications, water treatment, soil decontamination and flushing of well casings and water distribution pipes.
1. A method for generating a reactive oxygen species formulation, comprising:
generating an alkaline hydrogen peroxide solution;
mixing the alkaline hydrogen peroxide solution with an acyl donor such that a peracid concentrate is produced, wherein when the alkaline hydrogen peroxide solution and the acyl donor are mixed, the peracid concentrate has a molar ratio of hydrogen peroxide to acyl donor reactive groups ranging from about 1:1.25 to about 1.4, and maintaining, thereafter, the peracid concentrate pH value in a range from about pH 9.5 to about pH 12.5 until distributing the reactive oxygen species, and wherein the peracid concentrate has minimal hydrogen peroxide residual to minimize quenching of singlet oxygen.
2. The method of claim 1 , wherein the alkaline hydrogen peroxide solution is generated from at least one of an alkali and a hydrogen peroxide concentrate or electrochemically.
3. The method of claim 1 , wherein the reactive oxygen species formulation is a singlet oxygen precursor formulation.
4. The method of claim 1 , wherein the acyl donor is an acetyl donor.
5. The method of claim 1 , further comprising activating the reactive oxygen species using at least one of a Fenton or a Fenton-like catalyst, an ultrasound, an ultraviolet radiation or a thermal activation.
6. The method of claim 5 , wherein the reactive oxygen species formed in the further activation step is a hydroxyl radical.
7. The method of claim 1 , further comprising storing the alkaline hydrogen peroxide solution in a holding tank for at least one of immediate or future use.
8. The method of claim 1 , further comprising distributing the reactive oxygen species to its point of use, wherein the reactive oxygen species is distributed in at least one form chosen from the group consisting of a liquid, an ice, a foam, an emulsion, a microemulsion and an aerosol.
9. The method of claim 1 , wherein the alkaline hydrogen peroxide solution is electrochemically generated, has a pH value in the range of about pH 12.0 to about pH 12.5, and has a percent weight of hydrogen peroxide in the range of 0.1 to 3 wt %.
10. The method of claim 1 , wherein the alkaline hydrogen peroxide solution is electrochemically generated, and wherein, during the step of electrochemically generating the alkaline hydrogen peroxide solution, an acid concentrate is co-generated.
11. The method of claim 1 , wherein the reactive oxygen species is applied to the point of use by an application chosen from the group consisting of injection, flooding, spraying, and circulation.
12. The method of claim 1 , wherein the peracid concentration undergoes the following chemical reaction:
AcOOH+AcOO − → 1 O 2 +AcOH+AcO − .
13. The method of claim 1 , wherein the acyl donor is one of an oxygen-acyl or oxygen-acetyl donor or a nitrogen-acyl or nitrogen-acetyl donor.
14. The method of claim 1 , wherein the peracid concentrate has a molar ratio of peracetic acid to hydrogen peroxide of at least about 32:1.