Fig. 3. Oxygen concentration within the wetland (mgO2 L−1
) after a) 3, b) 10 and c) 15 days of operation. The key at the right indicates SO concentration. Note that the images are
longitudinal cross sections of the wetland (as in Fig. 1) which have been deformed to fit a reasonable size. The x-axis of each image represents the longitudinal direction of the
wetland (from 0 to 10.3 m) and the y-axis the depth of the wetland (from 0 to 0.7 m). Also note that the coloured areas of each image correspond to wetted areas, while the
white areas correspond to areas without water. Note that water level decreases from inlet to outlet.