Optimization of Subsurface Artificial Wetlands with Pine Tree Fruit (pine cones) as a Bed Filler for Municipal Wastewater Treatment

Background and Aims: Constructed wetlands are noticeably cost-effective in terms of energy consumption, operation and maintenance. Many researches have been done on the efficiency of wetlands removal in wastewater treatment but the information is limited on media used in these beds and its impact on treatment   efficiency. This study aimed to optimize subsurface artificial wetlands with pine tree fruit as a bed filler for municipal wastewater treatment. Materials and Methods: In this study sample and control pilots were made out of bricks and cement in dimensions of 2*1*0.8 meters.Used municipal wastewater passed through a primary sedimentation tank with a detention time of 3 hours and entered the pilot with flow rate of 0.85 liters per hour. Hydraulic detention time of beds was 8 days. Chemical parameters TN, TP, COD and TSS were evaluated by standard methods. Sampling were commited twice a week, each time in  compound way and a time span of 4 hours. Results were extracted based on data average floating. Results: According to data obtained from pilot performance the removal efficiency of TN, TP, TSS, COD, in the control bed were 79.68, 88.31, 85.3, 83.03 percent, and in the sample bed were 91.45, 92.88, 88.86, 86.6 percent respectively. Conclusion: The reason behind increased removal efficiency of using fruit trees can be the high level of area, especially high porous space and biofilm increase and consequently efficiency increase of organic carbon, Nitrogen and suspended solids.