CONTROL PROCESS FOR INFLOW SEWAGE WATER LOAD OF SEWAGE DISPOSAL PLANT

摘要

PURPOSE:To avoid the heavy load for microorganism and to prevent the quality of already treated discharge water from worsening, by diluting by high-grade treating water discharged from the last precipitation pool in case inflow sewage is a little flowing amount and bad water, at the time of treating the sewage by activated sludge method. CONSTITUTION:Inflow sewage is purified and disharged by passing through the sand settling pool 1 and the first precipitation pool 2, the air exposure vessel 3, the last precipitation pool 4 and the sterilization pool 5. Heavy load is burdened on microorganism and treating efficiency is lowered when inflow sewage is in bad quality and its amount is small at fine weather etc. In shch a case, quality of sewage entered the first pool 2 is measured by the tubidimeter 8 and measured value is compared with set up turbidity by the turbidity regulator 10. Amount of dilution water is increased when the turbidity is made larger than the set point. On this occasion, the dilution water amount regulator 12 is controlled by the difference of the rated inflow amount Q0 corresponding to the most suitable treating water amount and the real inflow amount Q1 and a high grade treating water discharged from the pool 4 is sent to the pool 2 by operating the pump 7 and then, the sewage with a small amount and bad quality is diluted and moreover, sewage treatment is carried out smoothly by preventing burden of the heavy load on microorganism.