Domestic wastewater and surface runoff treatment implementations by constructed wetlands for Turkey: 25 years of experience

The first studies on constructed wetland (CW) system in Turkey applied at the TUBITAK Marmara Research Center (TUBITAK MRC) in 1994. These studies carried out both in laboratory and pilot applications within TUBITAK MRC campus. Treatment performances were investigated by using different types of wetland plants in different types of wetland systems. After 2000, the real scale CW treatment systems where implemented in various regions of Turkey. Submerged horizontal flow systems (SFS-h or HF), free water surface flow (FWS) and various hybrid systems were applied in the Egirdir Lake basin. In order to treat both domestic wastewater and runoffs from agriculture, real scale CW systems designed in the Egirdir lake basin. Apart from these, the CW systems were built for the treatment of the domestic wastewater of 5000 people equivalent in the Konya closed river basin. Furthermore, pilot scale systems were carried out by using different types of wetland systems for the treatment of runoff from highways and railways in Sapanca lake basin. All of the treatment system has provided treatment criteria set forth in the regulations in Turkey. The biggest problems encountered in these systems are related to the operation and maintenance. Some systems have been inactivated because of not enough personnel have been allocated. In this study, applied research projects conducted in Turkey on CWs for 25 years were evaluated and relevant problems encountered presented.