The TP and STP removal efficiencies in four operational
stages are shown in Fig. 4. The TP and STP
contents in the effluent are 2.2 and 1.6 mg·L−1 for run
1, 1.7 and 1.4 mg·L−1 for run 2, 1.2 and 1.1 mg·L−1 for
run 3, and 1.9 and 1.8 mg·L−1 for run 4. The removal
efficiencies of TP and STP exhibit similar trends.
From run 1 to run 3, the TP and STP removal efficiencies
increases from 27.9% to 60.1% and from 20.4%
to 53.8%, respectively, whereas they decline to 13.6%
and 1.1% in run 4. Table 3 shows the phosphorus