| 摘要 |
PURPOSE:To enable to hold the decomposition ratio of cyanogen at a high level, by adding picric acid to gas liquor discharged from a coking factory to convert free cyanogen in the gas liquor into ammonium thiocyanate, and then treating said liquid with activated sludge. CONSTITUTION:After picric acid is added to gas liquor discharged from a coking factory to convert free cyanogen in said gas liquor into ammonium thiocyanate, said gas liquor is treated with activated sludge. As a result, the decomposition ratio of cyanogen is continually held at a high level of 75-85% as compared with 60-70% in a conventional method, even if the concentration of cyanogen in the gas liquor, the temp. of an aeration tank, etc. may be changed. In addition, picric acid used as a catalyst does not impede the activity of microbes in the sludge. Besides, formed ammonium thiocyanate does not impede the activity of microbes in the sludge, either. Picric acid and ammonium thiocyanate are easily decomposed by the microbes in the sludge. |
