drain and fill mode, as compared to continuous mode, and found
that while P removal efficiency was enhanced by batch-mode
operation, it had a surprisingly small effect on N removal effi-
ciency. Burgoon et al. (1995), evaluated both batch-loaded and
continuous flow SSF wetlands which received either primary or
secondary wastewater, and found that while the presence of plants
in these constructed wetlands had significant effects on C and N
oxidation (presumably due to oxygen transport by the plants),
periodic draining and filling of the wetlands did not have any
significant effect on biochemical oxygen demand (BOD5) or N
removal. More recently, Stein et al. (2003) compared the performance
of batch-loaded and continuous flow wetlands filled with
simulated wastewater, and found both superior nitrogen and
phosphate removal in batch mode operation.
The objectives of the present investigation were to evaluate i)
the influence of batch versus continuous mode on the removal
efficiencies of chemical oxygen demand (COD), N, and P in tropical
SSF constructed wetlands; ii) the quantitative role of the higher
aquatic plants in nutrient removal in these two alternative operational
modes.