Abstract:
The research was concerned on the efficiency of constructed wetland system for treating domestic wastewater. A comparison of three macrophytes (Typha spp., Canna spp., and Heliconia spp.) with various hydraulic retention time of 3, 1.5, and 0.75 days in various type of media (75:25, 50:50 and 25:75 by volume soil:sand ratio medium) had been done for obtaining the highest removal efficiency. The results showed that the system efficiency was decreased with the decrease of hydraulic retention time according to the increase of organic loading. And the system efficiency was increased while the soil concentration in the media was increased especially the phosphate removal efficiency, due to the increase of phosphate adsorption yield in the media.The constructed wetland system with Typha spp., Canna 5pp. and Heliconia spp. in 75:25 soils: sand media showed BOD, COD, TKN and total phosphorus (TP) removal efficiency as 89.81, 90.63, and 86.00%, 82.26, 82.11, and 75.32%, 67.45, 65.45, and 54.54%, and 88.76, 79.89. and 71.22% respectively. Both Typha spp. and Canna spp. showed higher efficiency than Heliconia spp.And Typha spp. showed high growth and removal efficiency in all growing conditions while Canna spp. showed high growth in 75:25 and 50:50 soil: sand media. However, the constructed wetland system with Typha spp. in 75:25 soil: sand media at hydraulic retention time of 1.5 day showed the highest BOD,COD,TKN,TP and suspended solid(SS) removal efficiencies as 89.8l?4.9, 82.26?6.84, 67.45?5.92, 88.76?3.12, and 83.8l?10.02% respectively.