Ozone plants

Over 100 years ago it had been demonstrated that ozone (Oj). the unstable triatomic allotrope of oxygen, could destroy molds and bacteria and by 1892 several experimental ozone plants were in operation in Europe. In the 1920s, however, as a result of wartime research, during World War I, chlorine became readily... 

Coulson, C., and R. L. Heath. Inhibition of the photosynthetic capacity of isolated chloroplasts by ozone. Plant Physiol. 53 32-38, 1974. 

Rich, S., R. Ames, and J. W. Zukel. 1,4-Oxathin derivatives protect plants against ozone. Plant Dis. Rep. 58 162-164, 1974. 

One of the interesting effects of ozone is the 56% increase in the linolenic acid content of ASG from ozonated bean leaves ( ), This led us to explore the source of the additional linolenic acid, Ongun and Mudd ( ) had reported that SG and ASG normally formed at the expense of free sterols in non-ozonated plants. What happens in ozonated plants ... 

Table IV shows typical results of the pool overloading experiments in the soybean trifoliate leaf. Visible damage to ozonated plants after 24 hr incubation was, as usual, taken as necessary for an experiment to be valid. Clearly, incorporation of label into protein was reduced where casein hydrolysate had been used in control and treated discs to overload the soluble pools. Just as clearly, total counts present in the soluble pool of treated tissue were reduced by ozonation whatever the after-treatment. The reduction of label in the soluble pool in control and ozonated discs due to casein treatment was approximately 30% in each case the reduction of label incorporation due to ozone was about 36% in the case of water treatment and about 14% in the case of casein treatment.

As was shown previously in some examples [15-18] in a large ozonation plant for water treatment, residual ozone in the gas exiting the ozonation stages could be sent back to the head of the water plant where it is injected in another compartment to aid flocculation, remove iron and manganese, or reduce the trihalomethane formation potential (see Fig. 8). In these cases, it is not surprising that these plants could also have a final disinfection ozonation step. 

The Saint-Maur ozone plant at Paris, the purpose of which is to sterilize filtered Marne river water, was put into operation in February 1953. The design was based upon information derived from the operation of pilot plants dating from the beginning of the century as well as operation of a large plant at Saint-Maur, the construction of which was achieved in the period, 1914 to 1918. 

When the ozone plant first started up, a large number of fish died suddenly at the Aquarium of the France d Outremer Museum, which is served with water from Saint-Maur. The cause was eventually traced to gas embolism in the gills of the fish, which came about through the presence of air bubbles in the water. The pumped water is saturated after ozone treatment, and the bubbles were released as the head decreased and as the temperature of the water increased during the long run through the pipelines in the museum. 

Initially (1933), the maximum output of the filter plant and pumping station was only 200,000 cubic meters a day (53,000,000 gallons per day). The present output of the ozone plant is 300,000 cubic meters (79,000,000 gallons per day), which has already been reached and even exceeded for short periods. As head losses are lower than anticipated, it should be possible to double the design output to 600,000 cubic meters a day, if the ozone production could be suitably increased during peak demand periods. 

Table I. Belmont Ozonation Plant Operation Data, 1950 to 1955...

At the time of installation, on the basis of information from other ozone plants, it was estimated that the stainless steel tube surfaces would have to be cleaned every 6 months. Only 20 of the 50 units have ever been cleaned. Those uncleaned are not in bad condition. This is the finest evidence of the efficacy of the complete air cleaning and drying. 

In France. In 1938, the first silica gel dryer applied to the Otto process was put in operation. Since then, this method of drying has normally been used in all Otto ozonation plants, except the Saint-Maur plant, which alone uses coohng. 

Ozone plants established according to the van der Made processes use calcium chloride as a dehydration agent. Only recently has silica gel drying been adopted. 

Figures 1 and 2 give operating data for the Bon-Voyage and Rimiez plants which use water from the Vesubie River. As can be seen, the treated water from the two ozone plants is excellent from all points of view.

Up to now, ozonation of drinking water has been considered too difficult, especially in comparison with chlorination. The outlay for the relatively expensive installations and the high costs of operation were objectionable. In most cases the plants have seemed unprofitable. It appears, moreover, that all the European ozonation plants still employ water-treatment processes which do not permit proper utilization of all the ozone produced by the ozonators. Perhaps 40% of the ozone is lost because of the difficulty of dissolving the gas in the water with the available means. On the other hand, there is no doubt of the actual efficacy of the ozone water treatment in the French plants in operation. 

The full-scale Berne ozonation plant has been operating since the spring of 1955. Constructed to treat a maximum of 1000 cubic meters (264,000 gallons) of water per hour, it is divided into two installations able to function independently. The capacity of each is 500 cubic meters of water per hour. 

Figure 9. Berne ozonation plant treatment apparatus. Installation I...

Berne does have a very fine ozonation plant, in which the water can be treated effectively. On the other hand, many interested visitors get the impression that ozone purification of water is very expensive, which is not true. 

The city of Diisseldorf is at present constructing (before finally deciding upon a full-scale ozonation plant) preliminary installation to treat 400 cubic meters of water per hour. 

John H. C., Rmoval of dyewaste colour from sewage effluent — The use of a full scale ozone plant . Water Science Technology, vol. 30, 275-283. (1994)... 

The actual ozone dose utihzed at a water treatment plant is determined by the quaUty of the raw water (i.e., how much ozone demand will be exerted) and what is the ultimate objective for using ozone. Plants using ozone for iron and manganese oxidation will need to apply a different dose than plants using ozone as a disinfectant for inactivation of protozoans such as Cryptosporidium. 

Sakaki T, Tanaka K, Yamada M. General metabolic changes in leaf lipids in response to ozone. Plant Cell Physiol 1994 35 53-62. 

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