Phosphorus release and uptake profile in the
modified OD system during four different operational
stages are shown in Fig. 2. 3
PO4− content in the influent
of all stage conditions was around 1.8 mg·L−1 except
that of run 3, which was 2.1 mg·L−1. However,
the effluent 3
PO4− content of 1.1 mg·L−1 in run 3 was
the lowest among the four stages.