Toxic odour causes pollution to environment. Removal of odour from wet processing sections of leather tanneries is important to preserve safety and occupational health. Such odour causing gases are identified in nature and are identified mostly as Ammonia, Hydrogen sulfide and Volatile organic compounds. The main constituents of odorous gases in tanneries are VOC’s (evolved during the action of enzymes in the process of decomposition and oxidation of hides and skin), NH3 and H2S (evolved during the unhairing and deliming in the processing of leather). Out of these, NH3 (Ammonical Smell) and H2S (Rotten-Egg like smell); both are toxic gases which are responsible for causing malodor in tanneries. Ozone has a very high oxidation potential which means that it breaks down the molecular structures of such odor-causing compounds. Since, odors often originate from organic compounds; these can easily be broken down with ozone. Great results have been seen in removal of H2S (hydrogen sulfide) and other volatile organic compounds (VOC) in such scenarios.
Natural Rubber (NR) processing sector is an industry which produces raw materials used for the manufacture of rubber industrial products (conveyor belts, rubber rollers, etc.), automotive products (fan belts, radiator hoses, etc.), latex products (rubber gloves, toys hygienic products, etc.) and many kinds of adhesives .The major users of natural rubber are tire and footwear industries. The effluent from latex concentrate factories contains high level of sulfate which originated from sulfuric acid used in the coagulation of skim latex. The high level of sulfate in this process can cause problem in the biological anaerobic treatment system as high levels of H2S will be liberated to the environment and malodor problems shall be generated. The free H2S also inhibits the digestion process, which gives lower organic removal efficiency. Ozone has been an effective treatment method for the removal of H2S from such exhausts.
Volatile organic compounds (VOCs) are the primary air pollutants emitted from rendering operations. The major constituents that have been qualitatively identified as potential emissions include organic sulfides, disulfides, C-4 to C-7 aldehydes, trimethylamine, C-4 amines, quinoline, dimethyl pyrazine, other pyrazines, and C-3 to C-6 organic acids. Ozone’s job is to oxidize or disassemble compounds that have combined to create the penetrating or truly offensive odors. These odors are typically base substances that have combined to form long-chain molecules, usually through anaerobic processes. The long-chain bonds of these compounds are relatively weak and can be easily broken down in the presence of a strong oxidizer like ozone.
In the printing industry, ever higher demands on quality and productivity lead to more solvents and additives. As a result, volatile organic substances are released in the printing process in quantities which – depending on the percent coverage – exceed permitted limits by far. The process of solvent-based printing is simple: A solvent component mixes with the ink, carries the ink to the media and is printed on the same media. The solvent then evaporates, leaving the ink behind to produce a print. This is where the problem begins. The evaporated solvent product has been deemed hazardous to people when exposed to high-concentration levels. Ozone has a knack of oxidizing such VOCs and has proved to be quite effective in reducing its concentrations from the exhaust air. Even the possibility of recycling such air can be considered with proper treatment.