Abstract:
This research work was studied on laboratory scale unit, It was found that the alternate feeding to six aeration tanks could be applied to control and solve the problem of filamentous bulking. Six experiment runs was conducted for 150 days, the results showed that the alternate feeding to six aeration tanks system at the organic loading of 0.36 gCOD/gMLSS-day had 95 percent COD removal, which was approximately to those of completely-mixed activated sludge system. When comparing between the alternate feeding and completely-mixed activated sludge system, it was found that the alternate feeding system had low SVI which varied between 40 to 80 ml/g, through 45 days of the experiment. While the completely-mixed activated sludge system showed the SVI value as high as 645 ml/g when the experiment had been performed for only 19 days. It was concluded that the alternate feeding system showed better results in controlling the filamentous bulking than completely-mixed activated sludge system. Further more, the alternate feeding system could solve the problem of filamentous bulking by bring the system back to normal condition within 20 days.