Daily TAN removal was estimated considering that the 0600-hour samples were representative of the whole night hours (15 h in December and 10 h in May). During the light hours, biofiltration was calculated considering the average between the values obtained at 1300 and 1600 hours in December and 1300 and 1800 hours in May and the number of light hours (9 h in December and 14 h in May).