| 摘要 |
<p>PURPOSE:To perform backwashing of contact filter media automatically and effectively at all times by automatically measuring the turbidity or solid concn. in the sewage to be circulated, emitting a signal when it attains more than a constant value, ejecting air from an air diffuser, and backwashing the contact filter media. CONSTITUTION:Air is injected from an air diffuser 5 for circulation to the sewage supplied 2 to a purification treatment tank 1 to induce water flow like arrows in the tank 1 and to circulate and flow the sewage in contact filter media 4, so that it is purifed by aerobic microorganisms. The purified treating water is flowed 3 out to the outside of the tank 1. During this purificatin treatment, the turbidity or solid concn. in the circulating sewage is measured with a sensor 10, and when the concn. thereof exceeds a constant value, a signal is transmitted 11, and this signal is received 12 to open a valve 7. As a result, the air from a fan 9 is fed via the valve 7 to an air diffuser 7 for washing, and is injected toward the filter media 4, whereby the propagated excessive biofilms are forcibly stripped off and are settled in a sludge storage part. After the sludge has accumulated in the sludge storage part upon lapse of a constant time, a valve 15 is opened to discharge the sludge.</p> |
