Sustainability of the constructed wetland based on the characteristics in effluent

Abstract

The constructed wetland (CW) in the settlement of Gložan is the first system of its kind for wastewater treatment constructed in Vojvodina (Serbia), aimed at treating local municipal wastewater. The common reed Phragmites australis, naturally growing at the CW location, was used as biofiltering vegetation. The monitoring effectiveness of the CW was based on removing suspended solids and reducing the amount of organic matter. The eight-year long study shows that the age of the constructed wetland does not significantly affect the changes (increase) in concentration of suspended particles and organic compounds from the wastewater effluent. We proved that measured values of variables, suspended solids, and biochemical oxygen demand (BOD<inf>5</inf>) of effluent belong to the same population. The chronological data series of suspended solids and BOD5 of effluent were processed using statistical tests of homogeneity, both parametric (Student's t-test with Fisher's F-test) and nonparametric (Mann-Whitney's U-test). The results of testing homogeneity of the data confirm that the constructed wetland has not been compromised, and that the removal of suspended solids is 93-96% and reduction of organic compounds, expressed in terms of BOD<inf>5</inf>, is up to 79-84%.