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. (C) 2009 Elsevier B.V. All rights reserved.