| 摘要 |
<p>PURPOSE:To carry out the titled biological treatment efficiently in a low installation cost by controlling an air blow-in amount of an aeration tank according to a pH detection value of a sludge mixed liquid in an aeration tank or a supernatant liquid of a precipitation tank or a value obtained by adding a variable speed thereof to said detection value. CONSTITUTION:In treating a nitrogen containing org. waste water such as domestic waste water or excretion by a biological treatment method such as an activated sludge method or a catalytic oxidation method, a pH of a sludge mixed liquid in an aeration tank 1 or supernatant liquid of a precipatation tank is detected by a pH meter 3 and, moreover, dissolved oxygen in the aeration tank is detected by a DO meter 4. These detected values are sent to a control circuit 5 and subjected to the decision against set values of a pH value and a DO value by decision circuits 6,7 and the decided signals of the circuits 6,7 are sent to a comparison circuit 8. The circuit 8 adjusts both decision results and a signal for controlling a base air amount according to a pH decision result and a signal for controlling a residual air amount according to a DO decision result are applied to a blower 2 and an air amount blown into the aeration tank 1 is controlled.</p> |
