Sodium Hypochlorite for Cooling Water Disinfection
Disinfection by means of Sodium Hypochlorite (Chlorine bleach) is one kind of chlorination. Because many microorganisms build resistance against Chlorine, the disinfectant is not added continuously to the cooling water but shock-dosed with concentrations of up to 10 ppm. Periodic treatment with a second organic biocide is usual to avoid the creation of resistances. For an efficient disinfection of cooling water with Chlorine, a pH value of maximum 7.5 is necessary whereas, for corrosion protection reasons, higher pH values are often aimed for.
Using Chlorine, the creation of biofilm in the cooling water is minimized but not excluded. Especially in organically charged cooling water, numerous by-products are generated during chlorination, leading to high AOX values in the effluent water.
Advantages
- Easy storage of the disinfectant
- Good depot effect
- Proven metering technology
- Online-measurement possible
Disadvantages
- Efficiency dependent on pH value
- Creation of resistances possible
- Generation of chlorinated by-products
Together with the respective measuring and control technology, DULCOMETER® or DULCOTEST, ProMinent metering pumps enable ideally inter-adjusted disinfection systems for cooling water treatment.
