Method and apparatus for producing synergistic biocide
View Patent ↗An apparatus and methods to produce synergistic mixtures (or combinations) of haloamines to control growth of microorganisms in aqueous systems are disclosed. The apparatus and methods to produce synergistic mixtures entails producing a batch quantity of a haloamine and converting part of the haloamine to a second haloamine species to form the synergistic mixture.
1. A method for producing an aqueous solution containing a synergistic combination of monohaloamine and dihaloamine biocide to control growth of microorganisms in an aqueous system which comprises
a) contacting an ammonium or an amine source with a halogenated oxidant in water in amounts of each effective to produce monohaloamine, and
b) converting a portion of the monohaloamine to a desired amount of dihaloamine by reducing the pH to a desired value below 7.0 thereby converting a desired portion of the monohaloamine to dihaloamine.
2. The method of claim 1 , wherein the ammonium or amine source is ammonia, ammonium hydroxide or an ammonium salt.
3. The method of claim 2 wherein the ammonium salt is selected from the group consisting of aluminum ammonium sulfate, ammonium acetate, ammonium bicarbonate, ammonium bifluoride, ammonium bromide, ammonium carbonate, ammonium chloride, ammonium citrate, ammonium fluoride, ammonium iodide, ammonium molybdate, ammonium nitrate, ammonium oxalate, ammonium persulfate, ammonium phosphate, ammonium sulfate, ammonium sulfide, ferric ammonium sulfate, ferrous ammonium sulfate, and combinations thereof.
4. The method of claim 2 wherein the amine source is selected from the group consisting of polyamines, primary amines, secondary amines, cyclic amines, bicyclic amines, oligocyclic amines, aliphatic amines, aromatic amines, primary and secondary nitrogen containing polymers and combinations thereof.
5. The method of claim 4 wherein the amine source is selected from the group consisting of dimethylamine, ethanolamine, ethylenedlamine, diethanolamine, triethanolamine, dodecylethanalamine, hexdecylethanolamine, oleic acid ethanolamine, triethylenetetramine, dibutylamine, tributylamine, glutamine, dilaurylamine, distearylamine, tallow-methylamine, coco-methylamine, n-acetylglucosamine, diphenylamine, ethanolmethylamine, diisopropanolamine, n-methylamine, n-hexyl-n-methylamine, n-heptyl-n-methylamine; n-octyl-n-methylamine, n-nonyl-n-methylamine, n-decyl-n-methylamine, n-dodecyl-n-methylamine, n-tridecyl-n-methylamine, n-tetra-decyl-n-methylamine, n-benzyl-n-methylamine, n-phenylethyl-n-methylamine, n-phenylpropyl-n-methylamine, n-alkyl-n-ethylamines, n-alkyl-n-hydroxyethylamines, n-alkyl-n-propylamines, n-propylheptyl-n-methylamine, n-ethylhexyl-n-methylamine, n-ethylhexyl-n-butylamine, n-phenylethyl-n-methylamine, n-alkyl-n-hydroxypropylamines, n-alkyl-n-isopropylamines, n-alkyl-n-butylamines and n-alkyl-n-isobutylamines, n-alkyl-n-hydroxyalkylamines, hydrazine, urea, guanidines, biguanidines, and combinations thereof.
6. The method of claim 2 wherein the halogenated oxidant is selected from the claim consisting of chlorine, hypochlorite, hypochlorous acid, chlorinated isocyanurates, bromine, hypobromite, hypobromous acid, bromine chloride, halogenated hydantoins, and combinations thereof.
7. The method of claim 1 wherein the ammonium or amine source is ammonium sulfate and the halogenated oxidant is a hypochlorite salt.
8. The method of claim 1 wherein, the halogenated oxidant is a chlorinated oxidant and the pH in step b) is adjusted until the ratio of monochloramine to dichloramine is 200:1 to 1:100.