Investigation of Performance Wetland In Removal N and P In Wastewater Treatment (Case Study:Morad Tapeh)

Etland is one of the natural treatment methods used for municipal wastewater treatment, which could transfer the effluents to the ecosystem, safely or being used for agricultural purposes and etc. this study investigates a pilot in the form subsurface flow wetland efficiency in rural sewage result of septic tank. The constructed Wetlandwas built in Morad Tapeh Village, Karaj County, Alborz Province.The pilot project was executed from galvanized plates with the dimensions of (length 20 m - Depth 1m - width 30 cm). 0.5 m from each side of the Pilot Project was covered by rubble-stones to the depth of 0.5m and the interval was filled by screened sand, porosity degree (α=0.39), maximum 10% of them measuring 2mm, with the hydraulic conductivity Ks=1575 F3, covered by 10cm peat. The study took one year, from Sept. 2009 to Sept. 2010. The plant used in this constructed Wetland, was the common straw, scientifically named as Pharagmites Australis and role of the pilot constructed Wetland was considered refining pollution, using this type of plant. It was supposed that the said project decreases the items P, N and some other parameters including TSS, COD and BOD and brings them within limits of the ecological standards. Tests were carried out according to the method, showing following results:(1)BOD input & output averages is 57± 31 and 8 ± 4 mg/l respectively, while its average elimination percentage is %79 ±15.(2)COD input & output averages is 97 ± 47 and 24 ±12 mg/l respectively, while its average elimination percentage is %70 ±16.(3)TSS input & output averages is 40 ± 47 and 5 ± 4 mg/l respectively, while its average elimination percentage is %76 ±16.(4)TN input & output averages is 13 ± 6 and 4 ± 3 mg/l respectively, while its average elimination percentage is %59 ± 26.(5)TP input & output averages is 7 ±7 and 8 ± 9 mg/l respectively, while its average elimination percentage is %86 ± 12.