A serially connected sand filtration and constructed wetland system for small community wastewater treatment

In this study, a newly developed combined natural wastewater treatment system was used for the first time in the Village of Ileydagi, which has a population of 313 situated in the reservoir of Lake Egirdir, the second largest freshwater lake in Turkey. The combined treatment system consists of a combination of buried sand filtration (BSF) and buried subsurface flow constructed wetland (BSSF-CW) systems. The total area of the BSF system is 582 m 2 and that of the BSSF-CW system is 1352 m 2. Performance of the combined treatment system was 5% higher during the summer period than during the winter months. The average removal values of the combined system observed for a 14-month period were as follows: Biological Oxygen Demand (BOD) 97%, total nitrogen (TN) 85%, and total phosphorus (TP) 69%. There is a strong correlation (0.81–0.97) between the loading and removal rates (g/m 2 d). This correlation is also statistically important. The results indicate that the novel sand filtration and constructed wetland treatment system is an optimal solution to the wastewater problems of small settlements.