Ozone corrosion effects

Except for atmospheric ozone depletion potential of perfluorinated compounds. Except for corrosive effects and potential toxicity. 

Chapter 1 through Chapter 4 covers polymeric (plastic) materials, both thermoplastic and thermoset. An explanation is presented as to the t) e of corrosive effects of each polymer, its ability to withstand sun, weather, and ozone, along with compatibility tables. 

Ozone similar effect as chlorine, decomposes to O2, no residues, decomposes biofilms Corrosive, inactivated easily, reacts with organics, safety monitoring needed... 

Materials The damage that air pollutants can do to some materials is well known ozone in photochemical smog cracks rubber, weakens fabrics, and fades dyes hydrogen sulfide tarnishes silver smoke dirties laundry acid aerosols ruin nylon hose. Among the most important effects are discoloration, corrosion, the soiling of goods, and impairment of visibility. 

N02 plays a major role in the chemical reactions which generate photochemical smog and ground-level ozone, as well as contributes to the acid rain effect. Nitrogen dioxide is a strong oxidizing agent, which reacts in the air to form corrosive nitric acid, as well as... 

A number of rather tenuous arguments suggest ozone damage to such materials as recording tape, asphalt, and dried milk. However, studies on such subjects are scattered and generally uncorroborated. Some studies even discuss beneficial effects of ozone, such as reduction of corrosion rates in steel and improvement in adhesion of ink to polyethylene films. 

Minimum effect of the UV unit on machine parts (no excessive heating or ozone-induced corrosion)... 

For the experimenter in the laboratory, not only do materials have to be chosen on the basis of their corrosion-resistance, but also for their effect on ozone decay. Some metals (e. g. silver) or metal seals enhance ozone decay considerably. This can be especially detrimental in drinking water and high purity water (semiconductor) ozone applications, causing contamination of the water as well as additional ozone consumption. Moreover, the latter will cause trouble with a precise balance on the ozone consumption, especially in experiments on micropollutant removal during drinking water ozonation. With view to system cleanliness in laboratory experiments, use of PVC is only advisable in waste water treatment, whereas quartz glass is very appropriate for most laboratory purposes. 

The photochemical smog contains several oxygen species such as atomic oxygen (0), ozone (0 ) and singlet oxygen ( O2) which are highly reactive with several polymers. The concentration of 0 and 0 is low and their effect is considered to be less important in the total corrosion of polymers than the effects of ozone, nitric and sulfuric acids. 

Ozone appears to have no significant effect on the corrosion of weathering steel. 

It would appear that ozone has a significant potential as an additive to combat fouling, in particular as a biocide to reduce biofouling. More detailed work is required however to improve the technology and in particular, to optimise dosing requirements to improve cost effectiveness. Investigations of the use of ozone in relation to other additives, e.g. corrosion inhibitors are also necessaiy. 

Addition of oxalic acid to chromic acid for the anodizing of A1 alloy has been reported to modify the morphology and improve the corrosion performance of anodic films (Moutar-lier et al. 2004). Also, it is a very effective additive for the ozone treatment of cellulose. It prevents the degradation of cellulose from ozone bleaching. 

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