Abstract
A laboratory scale biofilter was operated with synthetic wastewater to study the mechanism of organic removal in high-loading wastewater treatment. A reactor consists of 4 short stages was used with a total working volume 8.0l. The process was operated at 25°C with organic loading rate of 4.1-12.3 kgBOD·m-3·d-1, and dissolved oxygen concentration was about 3 mg·l-1. With the result that 97% organics substrates was removed, MLSS was found being a low value about 950-1,830mg·l-1 in average, slightly lower than that as in conventional activated sludge processes, and SRT was 0.75 day with a responsive higher gross yield coefficient of 58%. By the organic degradation rate tests, the microorganisms showed a greater activity. As the conclusion, it was proposed that it is the greater activity microorganisms being always maintained in the reactor, resulted from the frequent back washings, that made the high-loading wastewater treatment possible in biofilter.
