| 摘要 |
<p>PURPOSE:To sufficiently treat a harmful components-contg. gas despite the large change in the harmful component concentration and enable the chemicals concentration in the waste liquid to be controlled within a predetermined range by detecting the oxidizing or reducing agent concentration in the waste liquid of containing of respectively part of said gas and cleaning liquid at the time of contacting the circulatively used claening liquid with the gas. CONSTITUTION:The harmful components-contg. gas to be treated is fed by a blower 1 into a cleaning tower 2, where the cleaning liquid contg., for example, sodium hypochlorite of an oxidizing agent from a liquid reservoir 3 is sprayed from the tower 2 top by a pump 4, whereby the harmful components are removed. At this time, part of the gas to be treated and part of the cleaning liquid are drawn by a fixed amount respectively with a compressor 5 and a pump 6 and both thereof are led to a vapor-liquid contact reacting part 7 so that they are caused to react. The said oxidizing agent concentration in the waste liquid to be discharged from there is detected with a densitometer 10, and is compared with a preset value. When it is below the lower limit value thereof, the oxidizing agent is supplied to the cleaning liquid from its supply means 9 by a pump 8 and in this way, the oxidizing agent concentration is controlled to the preset value.</p> |
