Removal and prevention of biofilm by nanoparticle chemistries
Methods and compositions for biofilm removal in industrial applications and systems with prevalent biofilm and/or slime are disclosed. Various industrial processing, such as food and beverage processing, mining pipelines, cooling towers, and energy services applications benefit from the biofilm removal disclosed herein. In particular, the methods and compositions employ alumina nanoparticles alone or in combination with conventional biocides to remove biofilm and/or slime.
1 . A method for removing a biofilm from a negatively charged surface comprising:
contacting a biofilm with a composition comprising (i) one or more positively charged aluminum chlorohydrate nanoparticles having an average particle size of from about 1 nm to about 110 nm and in the form of a colloid, and (ii) one or more of a biocide wherein the biocide is formaldehyde, glutaraldehyde, acrolein, a quaternary ammonium compound, a peroxycarboxylic acid, bronopol, isothiazolone, a carbamate, metronidazole, or a combination thereof, a scale inhibitor, corrosion inhibitor, anionic polymer, stabilizing agent, surfactant, hydrotrope, dispersant, solidification agent, aesthetic enhancing agent, wetting agent, defoaming agent, thickening agent, gelling agent, and solvent; and
removing the biofilm from the surface, wherein the removing occurs by the one or more positively charged aluminum chlorohydrate nanoparticles interacting with the negatively charged surface, thereby disrupting biofilm adsorption to the negatively charged surface;
wherein the surface is located within a water system or water source,
wherein the one or more positively charged aluminum chlorohydrate nanoparticles, when within the water system or water source have a concentration between about 0.1 ppm and about 2000 ppm and the biocide has a concentration of between about 0.1 wt-% to about 20 wt-%;
wherein the composition has a pH between about 6 and about 8; and
wherein the composition does not include silica nanoparticles.
2 . The method of claim 1 , wherein the aluminum chlorohydrate nanoparticles have an average particle size from about 2 nm to about 110 nm.
3 . The method of claim 1 , wherein the aluminum chlorohydrate nanoparticles are in an aqueous dispersion at a concentration between about 0.5 ppm and about 1000 ppm.
4 . The method of claim 1 , wherein the aluminum chlorohydrate nanoparticles are applied in an aqueous dispersion at a concentration between about 1 ppm and about 62.5 ppm.
5 . The method of claim 1 , wherein the composition comprises from about 0.1 wt-% to about 20 wt-% of the biocide, from about 0.1 wt-% to about 20 wt-% of the aluminum chlorohydrate nanoparticles, and water.
6 . The method of claim 1 , wherein the composition comprises from about 1 wt-% to about 15 wt-% of the biocide, from about 1 wt-% to about 15 wt-% of the aluminum chlorohydrate nanoparticles, and water.
7 . The method of claim 1 , wherein the composition comprises from about 5 wt-% to about 10 wt-% of the biocide, from about 5 wt-% to about 10 wt-% of the aluminum chlorohydrate nanoparticles, and water.
8 . The method of claim 1 , wherein the water system or water source is one or more of the following: oil field drilling fluids and muds; petroleum recovery processes; mining pipelines; pipelines containing water; fire water; industrial lubricants; cutting fluids; heat transfer systems; cooling towers; gas scrubber systems; latex systems; clay and pigment systems; cooling system; cooling towers; food, beverage and industrial process waters; pulp and paper mill systems; brewery pasteurizers; sweetwater systems; air washer systems; decorative fountains; water intake pipes; ballast water tanks; and ship reservoirs.
9 . The method of claim 8 , wherein the water system or water source is not a water system or water source in need of purification, wherein the water system or water source is not treated with a filter in addition to the aluminum chlorohydrate nanoparticles, or wherein the water system or water source is not a water system or water source in need of purification nor is it treated with a filter in addition to the aluminum chlorohydrate nanoparticles.
10 . The method of claim 1 , wherein the biofilm comprises one or more of Escherichia coli, Pseudomonas aeruginosa, Staphylococcal bacteria, Enterobacteriaceae bacteria , and Streptococcus bacteria.
11 . The method of claim 1 , wherein the aluminum chlorohydrate nanoparticles further comprise one or more organic materials, inorganic materials, or a combination thereof.
12 . The method of claim 11 , wherein the aluminum chlorohydrate nanoparticles are mixed with the biocide, an additional functional ingredient, or a combination thereof to provide a disruption and removal of the biofilm.