WATER TREATMENT SYSTEM AND METHOD FOR CONTROLLING AERATION AIR QUANTITY THEREOF

摘要

A water treatment system is provided with: a first ammonia meter for measuring the ammoniacal nitrogen concentration in an activated sludge mixture in an aerobic tank provided with an aeration device; a second ammonia meter for measuring the ammoniacal nitrogen concentration in raw water flowing into a series of biological reaction tanks; an aeration air quantity control device for controlling the aeration air quantity in the aeration device on the basis of a target operation amount which is a target value for aeration air quantity in the aeration device; and an aeration air quantity calculation device for generating the target operation amount. The aeration air quantity calculation device has: a feedback control system including a first operation amount calculation element for generating a return target operation amount signal; a feed-forward control system including a second operation amount calculation element for generating a preceding target operation amount signal in accordance with the change amount per unit of time of the ammoniacal nitrogen concentration in the raw water; and an addition calculation element for adding the return target operation amount signal and the preceding target operation amount signal.