To investigate the removal efficiencies of LABs in STPs, influent and effluent samples taken from five STPs located in the Tokyo metropolitan area were analyzed. All STPs employed activated sludge treatment followed by physical treatment (settlement) in their treatment process. Concentrations of PLABs in the particulate phase of influent and effluent samples ranged from 5.70 to 12.5 mg/L and from 0.092 to 0.180 mg/L, respectively(Fig. 3), and the calculated removal rate was 97.0–99.2%. This was consistent with the previous reports. The present study also examined the LABs
partitioning in water by analysis of both dissolved and particulate phase of the STP influents and effluents, and confirmed that greater than 88.6–97.3% were present in
the particulate phase for both influent and effluent samples. This was consistent with physico-chemical nature of LABs, i.e. LogKow ranging from B7 for C10 homologs to B9 for C14 homologs.