3.1. Physical and chemical parameters
The physical and chemical parameters of effluent in the planted
and unplanted beds for the two experiments are summarized in
Table 1.
3.2. COD removal
The effect of batch and continuous flow on the removal of COD,
ammonium (NH4-N), nitrate (NO3-N) and total phosphorus (TP)
were evaluated. Table 2 shows the overall average effluent
concentration and removal of the water quality parameter.
Fig. 2 presents the comparison of COD effluent concentrations
between batch and continuous flow at 4-day retention time. For the
test series of 4-day retention time, there were no significant
differences (p > 0.05) for COD removal between batch and
continuous flow modes for either the planted or unplanted treatments.
The statistical results were the same for the 2-day HRT:
there was no significant difference when the results for batch mode
were compared to that for continuous flow (Table 2). When effluent
Fig. 1. Layout of the horizontal subsurface flow constructed wetland. COD concentrations in planted versus unplanted beds were