Column experiment
During the experiment, the pumping and loading of wastewater was controlled by a system of programmable switches,
connected to magnetic valves and electric pumps. A very high
dosing rate of wastewater was applied to mimic the most
extreme conditions that can arise in a filter well. Three daily
doses were applied, at 08:00, 12:00 and 18:00 h. The Polonite
columns were fed at a total rate of 4.4 0.1 pore volumes per
day, while the BFS columns were fed at 4.5 0.3 pore volumes
per day, corresponding to an approximate wastewater load of
8 and 5 L, respectively. The wastewater was pumped in up-
flow direction with a pumping rate of 60 mL min