The use of horizontal flow constructed wetland for treatment of sanitary wastewater in Iraq

Constructed wetland is engineering systems used for wastewater treatment, whose objective is to reuse water, under the controlled condition, the mechanisms of treatment that occur in natural environments, through the development and get better the process that includes the porous media, plants, and gathering microbial. This paper explains horizontal flow in constructed wetland treatment, the horizontal flow is moving through the gravel media bed and vegetation which permits the wastewater flow through roots and has contact with the biofilm created in the subsurface wetland. To estimate the quality of treated water, some physical, chemical and biological parameters were measured. Treated wastewater from fieldwork showed removal efficiency was increased with time and showed the average removal after detention time of 3, 4, and 6 days, respectively, (47.7 %, 53.2 %, 77.5%) removal of COD, (45.1%, 52.8%, 64.4%) removal of TN, (55.4%, 58.8%, 72.2%) removal of NH4, also average removal of Nitrate was (19.41%) after 3 days. The results showed that the system was effective in removing target pollutants.