Effects of anaerobic conditions on biological phosphorus removal and sludge settleability
- Bangkok : Asian Institute of Technology, 1993
- 88 leaves + 1 online resource
- Thesis ; no. EV-93-20 .
- Asian Institute of Technology. Thesis ; no. EV-93-20 .
A thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering
Thesis (M.Eng.) - Asian Institute of Technology, 1993
The effects of anaerobic conditions on biological phosphorus removal and sludge settleability in anaerobic aerobic activated sludge process have been studied by both continuous flow and batch experiments. In the continuous flow experiments, ten systems with different anaerobic configurations and various anaerobic retention time were operated. It has been observed that the growth of some filamentous organisms was suppressed under three-compartment anaerobic cascades as results of more soluble COD reduction and substrate gradient in anaerobic zone. The systems with anaerobic cascades also showed good phosphorus removal. It has been observed that anaerobic retention time should long enough to reduce soluble COD to penetrate aerobic zone. Longer anaerobic retention time such as 3 and 5 hours resulted in better phosphorus removal. In those systems without anaerobic cascade, severe filamentous bulking took place, even though the anaerobic retention time were similar to those of cascade systems. In the batch experiment, effects of anaerobic retention time on phosphorus removal was confirmed, suitable anaerobic retention time could achieve a better performance of phosphorus removal.