Abstract
The various organic matters of sewage are to be devided into dissolved matters and suspended matters. It is well-known that the dissolved organic matters can be removed by biological treatment within a short period of time, compared with suspended organic matters. Therefore, an advanced removal of suspended organic matters will contribute to the improvement of the biological treatment process.
An innovative sewage treatment with a Non-Coagulant Flotation-Filtration System followed by a biological treatment was studied in some pilot scale experiments.
The results of these experiments at the pilot plant obtained the following sufficient results ; for example the average SS and BOD removal at the pilot plants was 85% and 70%, respectively.
The effluent of this system was treated by biological treatment, these were the following results :
1) Almost equal BOD removal for the conventional activated sludge process was obtained within one to two hours retention time.
2) Nitrogen removal was obtained by the anaerobic-aerobic activated sludge process within six hours retention time.
