Seasonal changes of contamination removal in constructed wetlands systems

The investigation was carried out at two different hybrid constructed wetlands, whichtreated municipal sewage after mechanical treatment from small villages in PomeranianRegion, In all facilities first step of biological treatment were horizontal flow beds, Themain difference concerns configuration of the facilities and sewage distributions systemsinto vertical flow beds, The measurement period was divided into vegetation (from Aprilto October) and outside vegetation seasons (from November to March) for all analysedfacilities.The results allowed for estimation of efficiency removal of different contaminations inboth measurements seasons. Comparison of the amount of sewage and loads ofcontamination inflowing and outflowing from the facilities are presented. Achievedresults make it possible to estimate the rate of organic matter decomposition and nitrogenremoval in vegetation and outside vegetation seasons.