The quantitative role of the higher aquatic
plants in nutrient removal in these two operational modes was also investigated. Results indicated no
significant difference (p > 0.05) in COD removal between batch and continuous flow modes for either the
planted or unplanted treatments. Furthermore, the batch-loaded planted wetlands showed significantly
(p < 0.05) higher ammonium removal efficiencies (95.2%) compared with the continuously fed systems
(80.4%), most probably because the drain and fill batch mode presented systematically more oxidized
environmental conditions. With respect to TP removal, for both planted and unplanted beds, there was
significant enhancement (p < 0.05) 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).