Özgür Aktaş

Phosphorus removal and effect of adsorbent type in a constructed wetland system

Abstract This research project aimed to determine the technologically feasible and applicable wastewater treatment systems which will be constructed to solve environmental problems of small communities in Turkey. Pilot-scale treatment of a small community’s wastewater was performed over a period of more than 2 y in order to show applicability of these systems. The present study involves removal of phosphorus in horizontal (HFCW) and vertical (VFCW) sub-surface flow constructed wetlands operated in series. The pilot-scale wetland was constructed downstream of anaerobic reactors at the campus of TUBITAK-MRC. Anaerobically pretreated wastewater was introduced into this hybrid two-stage sub-surface flow wetland system. Wastewater was first introduced into the HFCW and then VFCW before being discharged. VFCW achieved up to 60–90% phosphorus removal whereas HFCW could remove only less than 20%. The effect of type of filling material on adsorption of phosphorus was investigated both in adsorption studies and in ...

Pilot-scale anaerobic treatment of domestic wastewater in upflow anaerobic sludge bed and anaerobic baffled reactors at ambient temperatures

Abstract The efficiencies of an upflow anaerobic sludge bed (UASB) reactor and an anaerobic baffled reactor (ABR) were compared for the treatment of domestic wastewater at ambient temperatures. Two pilot-scale anaerobic biological reactors were operated for about two years at ambient conditions at psychrophilic and/or sub-mesophilic temperatures. The average total chemical oxygen demand removal was 56 and 58% in the UASB reactor, whereas it was 41 and 50% in ABR, respectively, in summer and winter periods. The amount of methane gas production was between 0.05 and 0.18 m3 CH4/kg CODremoved in the UASB reactor, although no methane production was observed in the ABR. Temperature was not a limiting factor in anaerobic reactors that were operated at ambient conditions. Because of its higher efficiency, the UASB reactor was recommended over the ABR for the anaerobic treatment of domestic wastewater of the small community investigated within the scope of the study. However, anaerobic treatment of domestic wastew...

Point and Diffuse Sources of Pollution and Surface Water Quality in Marmara Basin of Turkey

Marmara Basin includes the areas in Turkey with the densest industrialization and population. Surface waters are threatened particularly by point sources originating from municipalities and industries, although most of them are discharged to the sea. Therefore quality of existing surface waters and the sources of pollution are of great interest. Watershed protection action plan has recently been prepared for the basin. A detailed study on calculation of pollution loads was one of the most important outputs of the project. For this purpose, pollution loads based on chemical oxygen demand (COD), total suspended solids (TSS), total nitrogen (TN) and total phosphorus (TP) were calculated. Water quality classes of surface waters were determined based on Turkish regulations using the data obtained by State Hydraulic Works (DSI). The relationship between point and diffuse pollution sources and water quality was examined. According to the obtained data most of the creeks around Istanbul are polluted by point sources originating from the highly populated and industrialized city of Istanbul and its suburbs. On the other hand, the creeks which feed Iznik Lake and downstream of Gonen and Biga Creeks are polluted by diffuse sources as well as point sources. Results showed that point-source pollution due to untreated or treated domestic and industrial wastewaters is mainly responsible from pollution in rivers and lakes of the Marmara Basin. Besides in the less populated areas, diffuse-source pollution originating from agriculture and livestock breeding is responsible from deterioration of surface water quality.