Treatment of domestic wastewater using a lab-scale activated sludge/vertical flow subsurface constructed wetlands by using Cyperus altemifolius

Activated sludge-vertical flow subsurface constructed wetland systems (VFSCW) were investigated in order to remove COD and N in sewage of Aksaray. Over a study period of 25 days, the system was able to achieve moderate total nitrogen removals with the range of removal efficiencies of 35.28% and 59.84% at organic loading rates of 940 mg TN/m(2) d. In the effluent of the system, COD and TN observed was higher than those by last of operation as roots of plant were decomposed and dissolved in the effluent of the system. Conventional wastewater treatment plant could not remove N and P in sewage in order to prevent eutrophication in receiving water bodies. CWs may be an economical option for N and P removal in the effluent of secondary treatment such as activated sludge, trickling filter of oxidation ponds because conventional nutrient removal is much costly and complex compared to natural treatment systems. (C) 2014 Elsevier B.V. All rights reserved.