Industrial applications surface disinfection

Cationic surfactants show a high affinity for negatively charged surfaces making them suitable for industrial applications and as components for consumer products where they are used as disinfectants, foam depressants, and first and foremost as textile softeners [23], Due to the possible formation of ion-pair associates they are usually not formulated together with anionic surfactants. 

The quaternary ammonium compounds (23) and (24) are most often used as disinfectants and sanitizers for hard surfaces. Other industrial applications are limited to slimicides for paper mills and cooling-water systems. 

Sodium hypochlorite (SO-dee-um hye-po-KLOR-ite) is the active ingredient in liquid chlorine bleaches, used in the home and many industries to whiten fabric and other materials and to disinfect surfaces and water. The anhydrous compound is very unstable and explodes readily. The pentahydrate is a pale-green crystalline solid that is relatively stable. The compound is usually made available as an aqueous solution that contains anywhere from 3 to 6 percent sodium hypochlorite (for household use) to as high as 30 percent (for industrial applications). In solution form, sodium hypochlorite is quite stable and can be stored for long periods of time out of sunlight. 

Future work in this area must focus on research on toxicity and may address environmental pollution materials and meta-materials in two- and three-dimensional objects. These same objects may be useful in disinfecting pathogens that can survive for long times in the form of surface biofihns. Biofilms are currently the most common and dangerous way to spread highly infectious pathogens into the environment in pubic places and health-care facilities. New products developed from research in this area could be of interest for industrial applications. 

The chemical reactivity of sodium hypochlorite has been used by scientists in order to benefit from its many possible chemical interactions with inorganic or organic entities. Sodium hypochlorite is used in very strong industrial oxidation processes and is also handled by consumers for household maintenance. This chapter will deal only with household applications and uses, which range from laundry whitening and destaining to surface disinfection and deodorization. From a commercial standpoint, aqueous solutions of sodium hypochlorite have been sold worldwide for many decades under a multitude of well-known brand names and is known generically, for instance, as bleach or eau de Javel. 

More than 80% of all sodium chlorite produced is used for the generation of chlorine dioxide. Sodium chlorite is also used in disinfectant formulations and sterilization. Like chlorine dioxide, it must be registered with EPA under FIFRA for each specific application use as a disinfection. Sodium chlorite is used in other industrial settings in NO and SO combustion flue gas scrubber systems in the treatment and removal of toxic and odorous gases such as hydrogen sulfide and mercaptans and as a solution formulation to oxidize copper surfaces in multilayer circuit boards (Kaczur and Cawlfield 1993). 

The photod)mamic approach has been applied for the cleaning and disinfection of artificial surfaces, especially for the destruction and inactivation of biofilms. In the majority of cases, it was proposed for the cleaning of surfaces in hospitals (Decraene et al., 2008a,b) and the disinfection of medical devices such as implants (Sharma et ah, 2008). Only a few papers on the application of PDT targeted to the needs of the food industry have been published. 

Alkylphenol ethoxylates are chemically stable and highly versatile surfactants that find application in a large variety of industrial products including acid and alkaline metal cleaning formulations, hospital cleaners, herbicides (qv) and insecticides, oil-well drilling fluids, synthetic latices, and many others (see Disinfectants and antiseptics Elastomers, synthetic Insect control technology Metal surface treatments Pesticides Petroleum, drilling fluids). 

Ozone is residue-free in water due to its self-decomposition into oxygen. As described above, ozone has been extensively used in water and wastewater treatment since its first full-scale application in drinking water treatment at Oudshoorn, Netherlands, in 1893. To date, ozone has been used full scale for disinfection and purification of ground and surface waters, treatment of municipal and industrial wastewater, and treatment of swimming pool and cooling tower waters.P 4 1 1... 

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 ... 

As clearly indicated by Dr. Kalvoda the application of electrochemical processes for the removal of pollutants is mainly concerned with the many sources of toxic heavy metals such as chemical manufactures, metal plating, surface treatment, mining and metallurgical operations. Electrodeposition, electroreduction to insoluble species and the use of sacrificial anodes are the techniques most widely used in this field. The production of chlorine from saline waters in urban or industrial wastewater treatments must also be quoted as a very interesting and practical example of an electrochemical application to the disinfection of different types of water. 

Calcium hypochlorite is a dry chlorine donor produced by the introduction of chlorine in aqueous suspensions of calcium oxide at 20° C. The product is suitable for use in applications where the disinfecting and oxidizing power of chlorine are needed e.g. in the beverage and food industry, and in hospitals for hard surface cleaning, for water treatment including waste water and sewage effluent, in pulp and paper mills, in taimeries. 

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