Fig. 4 shows the comparison of the TP effluent concentration
between batch and continuous flow modes at the 4-day retention
time. For both planted and unplanted beds, there is significant
enhancement (p < 0.05) of TP removal in batch flow operation
(69.6% for planted beds; 39.1% for unplanted beds) as compared to
continuous flow operation (46.8% for planted beds; 25.5% for
unplanted beds). In addition, in both batch and continuous operation
modes, planted beds showed significantly better TP removal
efficiencies (p < 0.001) than that in unplanted beds