“…8, No. 5; Theoretical speaking, there are hidden two natural processes; firstly, aquatic plant photosynthesis during daytime to provide oxygen as the processing (Sooknah and Wilkie, 2004;Hadad et al, 2006;Tanji et al, 2006), and secondly, thermo-osmosis process produces oxygen to bacteria for organic digestion during photosynthesis process of very young leaves, containing aerenchyma cells, of aquatic plants (Deubigh and Raumann, 1952;Bearnan, 1957;Srivastav and Avasthi, 1975;Grosse, 1989;Buchel and Grosse, 1990;Grofse and Bauch, 1991) The size of the constructed wetland has been used for wastewater treatment from various point sources for long period of time in which it depends on the amount of polluted wastewater, space availability, and topographical characteristics but normally varying on depth 0.3 to 1.0 m, surface area 100 to 600 m 2 ; mostly rectangular-shaped surface area and 1:1.000 slope (Tripathi and Shukla, 1991;Jenssen et al, 1993;Juwarkar et al, 1995;Ahn and Mitsch, 2002;Stottmeister et al, 2003;Maine et al, 2006;Yang et al, 2008;Li et al, 2009;Stefanakis and Tsihrintzis, 2012). The Photosynthetic rate of wetland plants were highly correlated with light intensity and temperature due to influence of oxygen evolving activities and disposal efficiency.…”