Treatment of rural wastewater with constructed wetlands: Denizli case

Wastewater treatment requirements in rural areas are increasing day by day. Again, developing treatment methods may cause high costs in matters such as initial investment, operation, maintenance and energy. At this point, constructed wetlands, which are a natural, environmentally friendly and easy method, can meet the need. In this thesis study, a study that can guide decision makers in conceptual and real terms has been carried out for rural towns in Denizli Province, Turkey. Within this thesis context, the current situation, requirements, existing rural treatment plants, their problems and improvement areas in Denizli province were examined, and sequential batch biological package treatment plants and constructed wetlands were compared among the existing plants. In addition, trials were carried out for more than a year in 4 pilot tanks, and as a result of the situation assessment of existing plants, pilot results and comparison studies, real-scale designs were developed for the new towns needed and the new CsW (constructed wetland) plants were constructed in the field. On average for all indicators, the highest efficiency was achieved in the vertical subsurface flow CsW, followed by the horizontal flow CsW and finally the free surface flow CsW. Removal efficiency for BOD5 are 91, 87 and 80% respectively. Again, the free surface flow CsW constructed at the outlet of the facility has achieved a significant improvement in the output water with a very low investment and almost zero operating costs. In this pilot plant, an average of 20% removal of total nitrogen was achieved. As a result of above studies, newly designed and constructed plant data are also presented in this study. By the thesis study, valuable information derived that will enable decisions to be made on an administrative, technical and financial scale regarding treatment plants that can be built in rural areas in Denizli and similar cities, and concrete support was provided to decision makers in preferring constructed wetlands.