Effect of a hydrolytic/acidogenic pre-stage on the organic matter content of wastewater treated in a sequencing batch reactor for biological phosphorous removal.
An increase of 52.7% in acetate concentration was observed when urban wastewater was used to feed a pilot-scale upflow-type, fixed-bed fermentor under a hydraulic retention time of 0.78 h. The fermentor influent and effluent were successively used to feed a laboratory-scale sequencing batch reactor (SBR) using similar operational variables of wastewater volume, sludge purging volume and retention times during the anaerobic and aerobic phase, giving a nominal 4 h hydraulic retention time. The fermentor effluent contained an organic substrate, with a volatile fatty acid content higher than 50mg L(-1), which was appropriate for the growth of the type of microorganisms characteristically found in biological phosphorous removal (BPR) systems, and showed the behaviour of an easily and rapidly biodegradable wastewater. The specific rate of phosphorous release at the anaerobic stage was found to be higher than 0.04mg Pr g VSS(-1) min(-1), when the fermentor effluent is used as feed of the SBR, which demonstrated its favourable conditions for an efficient processing in this type of systems.
Colmenarejo
M F
MF
Centro de Ciencias Medioambientales, CSIC, Madrid, Spain.
Bustos
A
A
Garcia
G
G
Borja
R
R
D000143:Acids / Q000737:chemistry; D001421:Bacteria, Anaerobic / Q000502:physiology; D019149:Bioreactors; D005227:Fatty Acids / Q000737:chemistry; D005285:Fermentation; D006868:Hydrolysis; D009930:Organic Chemicals; D010758:Phosphorus / Q000378:metabolism*; D014835:Volatilization; D014865:Waste Disposal, Fluid / Q000379:methods*; D014871:Water Microbiology; D014872:Water Movements
D000143:Acids; D005227:Fatty Acids; D009930:Organic Chemicals; D010758:Phosphorus