Cooling water, industrial, biocide

Uses Photography prep, of bromides biocide precursor for cooling water treatment biocide in pulp/paper industry oil-well drilling fluids pharmaceutical intermediate medicine (sedative)... 

Biocides are commonly used for many industrial applications, preferably in closed-circuit systems such as cooling water systems. Biocides may be divided into two main categories (a) oxidizing agents such as chlorine, ozone, and hypochlorite and (b) non-oxidizing agents such as isothiazoUnes, aldehydes, chlorophenols, and quaternary ammonium salts. 

The key markets for quaternaries are as swimming pool algaecides and in cooling water appHcations (see Water, treatment of swimming pools, spas, AND HOTTUBs), which further explains their importance as process biocides rather than preservatives. Some uses in latex films and plastics have been claimed (14,15). Primary quaternary ammonium industrial antimicrobial agents and their producers are presented in Table 4. 

Around the world, the most widely used biocide for industrial cooling systems is gaseous chlorine. Typically, it is a low-cost maintenance item and generally very effective, but may present specific cooling water chemistry limitations, plus possible handling, safety, and environmental problems. (The relatively high capital costs associated with a gaseous chlorine system may also be a problem.)... 

For some industrial cooling water applications, where process contamination is often an inherent problem, a high chlorine/low bromine ratio product may be preferable. This type of problem can happen, for example, where repeated hot/cold cycles are part of the process and some valve leakage and interchange of water between circuits may occur. Thus, the (lower cost) chlorine component is employed in satisfying the contaminant halogen demand and the bromine component (perhaps with some degree of Br recycle) subsequently acts as a biocide. 

There are almost countless combinations of biocide blends being used around the world, each product using two or three or possibly more of the primary products discussed in the previous section. Many combinations were originally designed for the pulp and paper industry and have been later adapted for cooling water and other applications. 

The choice of biocides from this list will depend on the application, e.g. cooling water or paper making or other industries using water, to combat the particular microbiological system. 

A number of papers have been published on the merits and application of ozone in industrial cooling water systems. Claims made in a patent [Humphrey et al 1979] are that ozone in concentrations of 2 - 20 mg/l prevents scale formation and removes existing scale, passivates metal surfaces to inhibit further corrosion and disinfects the water to prevent algae growth. Edwards [1983, 1987] and Edwards and Sellers [1991] have published valuable reviews of ozone technology and cooling water. As well as biocidal activity the benefits of using ozone include ... 

Kaur, K., Leadbeater, B.S.C. and Bott, T.R., 1988, Ozone as a biocide in industrial cooling water treatment. Proc. Int. Conf. Fouling in Process Plant, University of Oxford. 

Fig. 16.3 gives the flow sheet of a cooling water system commonly used in power generation that is also used in the process industries. Chemicals such as acids, biocides, scale and corrosion inhibitors and dispersants are added to control problems of fouling in the recirculating system (described elsewhere in this book). The technique is generally applicable where the make-up water is generally of low hardness and silica and low concentration factors are employed. 

Uses Biocide for metalworking fluids, latex paints, caulks, adhesives, oil field water systems, drilling muds, cooling water treatment industrial preservative crosslinking agent for polymers and resins corrosion inhibitor PU catalyst alkaline buffer... 

General information. Glutaraldehyde is a 5-carbon dialdehyde that has seen extensive use in industrial water treatment applications. In addition to its use as a biocide in oil and gas operations, it is also used in cooling water, paper making, and preservative applications, medical instrument sterilization, and as a non-biocidal crosslinker for leather. X-ray films, and enzyme immobilization. It is often used in oilfield applications in combination with other non-oxidizing biocides such as QAC s and formaldehyde and is compatible with the oxidizing biocides typically used in cooling water applications. 

Uses Surfactant biocide for Industrial water treatment, recirculating cooling water systems, swimming pool algicldes act. Ingred. for formulation of low-foam disinfectants and sanitizers Features Low-foaming Regulatory ERA reg. no. 6836-50... 

Uses Water treatment formula to prevent buildup of min. scale and to control corrosion in industrial water circuits mainly used in open cooling water systems incorporated additive controls growth of algae and slime bacteria contains no biocides dispersant and cleaning effects protection against corrosion of steel, copper, and copper alloys stabilization of hardness forming salts even at high water temps. 

---