Organic Matter and Polyhydroxyalkanoates in Biological Phosphate Removal from211 Municipal Wastewater (Orgaaninen Aine ja Polyhydroksialkanoaatit Biologisessa 211 Fosforin Poistossa Yhdyskuntien Jaetevesistae)

摘要

This study presents the importance of polyhydroxyalkanoates (PHA) in biological211u001ephosphate removal (BPR) in a UCT-type process treating municipal wastewater at 211u001ethe Suomenoja technical scale wastewater treatment plant. The PHA (including 82% 211u001ePHB and 18% PHV on an average) content of the sludge was analyzed from freeze 211u001edried sludge samples collected from the anaerobic, anoxic and aerobic basin of 211u001ethe process. The method for PHA determination was verified in a ring test set up 211u001eby the COST 682 group between five European laboratories. The method appeared to 211u001ebe accurate in a wide concentration range. Overall, 63% of the phosphate 211u001emeasurements made during the 308 days of the study period were under the 0.5 mg 211u001eP/I effluent limit value given by the water authorites for the Suomenoja 211u001ewastewater treatment plant. Phosphorus could thus be removed biologically, but 211u001ethe possibility for a chemical precipitation is essential to guarantee that 211u001eeffluent limit value are met also during distrubances of the BPR process.