Odor control technology is a very difficult technique unlike a prevention of various operation and air pollution technology in the chemical industry.

This is because it must process a very low-concentrated blend shown by laws of Weber -Fefuner to a sense of smell level (the sense of smell threshold).

The technique to be related to odor measure was developed based on an existing technique about prevention of chemical industry and air pollution basically.

However, many researchers and deodorization equipment makers went ahead through the research and development competitively, and, as for Offensive Odor Control Law line enforced in 1972, it was with a driving force to send a superior Odor measures technology out in the world.

In this special feature, I had a process of the development and representative embodiment introduce to the engineers who was engaged in the development of the prevention of odor control technology for many years.

Combustible odorous compounds are decomposed releasing the heat in combustion chamber of Regenerative Thermal Oxidizer, which gas temperature is kept approximately over 800 degC. In addition, the honeycombs recover over 90% of heat from the treated gas and preheat the raw gas. Therefore, for example, a raw gas containing around 460ppm of toluene is decomposed without additional heating. Moreover, rotary concentrator is used in combination with RTO to treat the low concentration raw gas with less energy consumption.

The odor generated in the waste treatment facilities is a complex odor various components have been included. Countermeasures such as separating and sealed at the source of the odor is important before considering the deodorizing device as measures of odor removal. Deodorizing device can give full performance to its function this measure has been made. Here, the washing deodorization system (chemical washing deodorization) and biological deodorization system (soil deodorization, filling type biological deodorization) which has been adopted relatively more from a variety of deodorizing equipment, and the principle, the feature, structure, an important matter, etc. are described.

Because the active carbon has very high adsorption performance, it is being used now in public accommodation including sewerage treatment plant or manufacturing factory A lot of active carbons which I added a special function to were developed recently.

By one and the combination of other deodorization methods including the absorption method, the applied range of the active carbon became wide

On the other hand, the deodorant is used as a technique to deodorize a diffuse bad smell by the appropriate choice and compounding.

In this report, I speak the principle of the skill technique to deodorize with an active carbon and the deodorant and application example as a representative deodorization method.

Odorants generated in living spaces spread through air, but they do not spread evenly due to the influences of factors, such as furniture arrangements, and consequently shows odorant deflec-tions. Such odorants are major sources of orders we perceive in our daily lives. Unpleasant feelings caused by them may be particularly marked in places with a high odorant concentration. Deodorizer use is onesolution ; however, there have been no studies quantitatively examining its effects in consideration of the above-mentioned odorant deflections. Considering such a situation, in the present study, a method to evaluate the efficiency of deodorizers using an apparatus with a spatial volume of 2m³, simulating a counter-type kitchen unit, was developed. The study de-odorizers placed in an area of the apparatus with a high odorant concentration reduced the concentration by approximately 75% in their vicinity and 50% even in distant areas, suggesting that deodorizer use may reduce unpleasant feelings due to odors within an entire space. It is shown the possibility of building the deodorizer performance evaluation method in the life space.

Field investigations on wastewater quality and odor emissions at a potato starch factory were conducted from July 2007 to May 2008. Odor index of decanter effluent and separator effluent in penetration ponds ranged from 43 to 51, suggesting that anaerobic decomposition of wastewater with high concentration of organic matters especially in decanter effluent inflicted odor emissions with time. Intensive putrid odor like lower fatty acids with the highest odor index of 32 was perceived at the boundary downwind from the penetration ponds, and the highest odor index of 25 was obtained at the farmland after application of wastewater, indicating the concern about a wide-spread effect of odor. Among odorous substances emitted from wastewater, n-valeric acid, isovaleric acid and n-butyric acid were considered to be associated with perceived odors at the sites. It was suggested that odor index at the site could be evaluated relatively by using that estimated based on the concentrations of these acids in wastewater.