ENVIRONMENTALLY FRIENDLY HYBRID MICROBIOLOGICAL CONTROL TECHNOLOGIES FOR COOLING TOWERS
This is a method that is an environmentally friendly hybrid microbiological control compromising a physical method through fine filtration, which removes nutrients, bacteria and suspended solids from open recirculating cooling systems. The method for microbiological control in cooling systems wherein a recirculating fluid containing an oxidising or a non-oxidising biocide or a mixture of an oxidising and a non-oxidising biocide and is passed through a fine filtration system resulting in reduced microbiological matter, suspended solids and nutrients.
1 . A method for microbiological control in cooling systems where in a recirculating fluid containing a biocide and is passed through a fine filtration system.
2 . The method of claim 1 wherein the recirculating fluid is diverted to a side stream then passed through the fine filtration system.
3 . The method of claim 1 wherein the fine filtration system contain membranes that have a pore size at 5 or less μm.
4 . The method of claim 1 wherein the fine filtration system contain membranes that have a pore size from 0.01 to 0.10 μm.
5 . The method of claim 1 wherein the fine filtration system contain membranes that are micro ultra-filtration membranes.
6 . The method of claim 1 wherein the fine filtration system is back flushed to regenerate the membranes.
7 . The method of claim 1 wherein the fine filtration system is air scrubbed to regenerate the membranes.
8 . The method of claim 1 wherein the biocide is an oxidising biocide.
9 . The method of claim 6 wherein the oxidising biocide is one or more of the following: chlorine, hypochlorite, ClO2, bromine, ozone, hydrogen peroxide, peracetic acid and peroxysulphate.
10 . The method of claim 1 wherein the biocide is a non-oxidising biocide.
11 . The method of claim 10 wherein the non-oxidising biocide is one or more of the following: glutaraldehyde, dibromo-nitrilopropionamide, isothiazolone, quatemary ammonium, terbutylazine, polymeric biguanide, methylene bisthiocyanate and tetrakis hydroxymethyl phosphonium sulphate.
12 . The method of claim 1 wherein the biocide is a mixture of an oxidising biocide and a non-oxidising biocide.
13 . The method of claim 1 wherein the biocide is one or more of the following: chlorine, hypochlorite, ClO2, bromine, ozone, hydrogen peroxide, oxygen based biocides, peracetic acid, peroxysulphate, glutaraldehyde, dibromo-nitrilopropionamide, isothiazolone, quaternary ammonium, terbutylazine, polymeric biguanide, methylene bisthiocyanate and tetrakis hydroxymethyl phosphonium sulphate.
14 . A method for microbiological control in cooling systems where in a recirculating fluid containing an oxidising or a non-oxidising biocide or a mixture of an oxidising and a non-oxidising biocide and the recirculating fluid is passed through a fine filtration system contain membranes that have a pore size at 5 or less μm.
15 . The method of claim 14 wherein the fine filtration system contain membranes that are micro ultra-filtration membranes.
16 . The method of claim 14 wherein the fine filtration system is back flushed to regenerate the membranes.
17 . The method of claim 14 wherein the fine filtration system is air scrubbed to regenerate the membranes.