IDENTIFICATION AND DESTRUCTION BY OZONE OF ODORS IN SEWAGE-TREATMENT PLANTS

The sewage treatment plants, due to living space problems and the growth in the size of townships, find themselves more and more often close to housing estates. Evolution of the organic matter contained in waste waters gives rise, in certain circumstances, to the build up of reduced by-products that often give off an obnoxious smell. This situation may also be worsened by inadequate operation of the plant or modified by the application of new techniques that the designer is trying to work out. The identification of the main families of pollutants contained in the stale air pervading a sewage plant or sludge treatment units has made it possible to devise a deodorizing system in which water scrubbing and ozonization are associated. The results obtained both with pilot and industrial size plants show that by using 6 to 7 mg of ozone per m3 of air, acceptable elimination of the smell was obtained in the majority of cases. The cost of this process compared with a diversity of existing solutions is among the lowest. © 1979.