| 摘要 |
<p>PURPOSE:To prevent the self digestion and extinction of activated sludge and to enable to start the contaminated water treatment immediately corresponding to the increase of contamination concentration, by decreasing or stopping the supply of gas containing oxygen automatically when the containation concentration is decreased, at the time of treating contaminated water by activated sludge method. CONSTITUTION:The outer cylinder 2 is arranged outside of the high inner cylinder 1 and the contaminated water 6 and the returning part 5 of activated sludge, are flowed from the upper part of the cylinder 1 and then, are descended in the cylinder 1. Moreover, the water 6 is ascended in the cylinder 2 and is circulated through the cylinder 1 again by the pump P. On this occasion, gas containing oxygen is dissolved in the water 6 sending in the above gas from the gas supply nozzle 7 and contamination index, such as COD etc., by the activated sludge, is improved. Contamination concentration of the water 6 is detected by the contamination concentration detector 14 in the cylinder 2 and when detected value is lowered lower than set point, supply of the gas containing oxygen is stopped or decreased by operating the valve 13 of the oxygen-contained gas supply tube 9 by the control unit 16 and self digestion and extinction of the activated sludge is prevented.</p> |
