The Efficiency of Pollution Removal From Domestic Wastewater in Constructed Wetland Systems With Vertical Flow With Common Reed and Glyceria Maxima

The paper presents the results of research on the effects of removing pollution from domestic wastewater in two beds of constructed wetland systems with vertical flow. Bed I was planted with common reed (Phragmites australis Cav. Trin. Ex Steud.), whereas bed II with Glyceria maxima (Glyceria aquatica L.). The surface of each of the beds amounted to 30 m², and the hydraulic load of each of them amounted to 0.033 m³·m^-2·d^-1. The study showed very good results in the removal of most of the analyzed indicators of contamination, which were similar in both analyzed beds. They were, respectively: 91 and 93% – for total suspended solids, 96 and 98% – for BOD₅, 96 and 94% – for COD_Cr, 88 and 86% – for ammonia nitrogen and 87 and 88% – for total phosphorus. Much smaller effects were reported with regard to total nitrogen removal – 55% in bed I with common reed and 54% in bed II with Glyceria maxima. The tested beds also eliminated the number of coliform bacteria and faecal coliform bacteria quite effectively. Average effects of the removal of coliform bacteria in bed I and II were 99.74%, in the case of faecal coliform 98.06% and 97.94% respectively. Values of basic indicators of contamination (total suspended solids, BOD₅ and COD_Cr) in the wastewater discharged from the analyzed beds met the requirements of the Regulation of the Minister of the Environment of 2014. The test results obtained in the first year of operation of the analyzed beds show that neither of the applied plants significantly improves the results of contaminant removal.