The Photodegradation efficient of total organic compounds in the drinking water has been studied using the methods of photocatalytic reaction and laser beam irradation. The results are summarized as follows; 1. The photodegradation efficiency of total organic compounds shows as 50% to 80% as within one hour and after this the efficiency is decreased slowly. 2. The photodegradation efficiency of total organic compounds shows as 65 to 90% within 3.3min. when Nd : YAG beam is irradiated to the water layer. 3. An excellent observation of the organic compound removal efficiency gives revealed in that case of the longest wavelength of 532nm is irradiated among the three kinds of laser beam sources of 532nm, 355nm and 266nm. 4. The organic compound removal efficiency shows high in the case of UV beam irradiation in the thin layer of water. However the efficiency is not depended on the thickness of water layer severely. 5. The removal efficiency of the organic compounds in the direct irradiation shows higher than the indirect irradiation in the case of UV beam, but the efficiency is not depended on the direction of irradiation in the case of Nd : YAG beam irradiation.

In recent years increasing production and disposal of wastewater have caused an accelerated eutrophication of receiving waters. Therefore, in order to alleviate the detrimental impact of wastewater discharge, there is an increasing demand for removing the main nutrients, nitrogen and phosphorus, as well as the organic content of the waste water prior to disposal. This is effectively achieved by extended conventional treatment technology. However, the working expenses and energy requirements of such advanced treatment systems are rather high. So in a sparsely populated rural community is required development of wastewater treatment system combined with the regional characteristics. In this study, the systems are planted with Reeds and Amaryllis in A.C and estimated purification potential of system. The results obtained are as follows. BOD removal rate is 20% in the early stage, the last removal rate is 35% in A.C process and is 65% in Amaryllis+A.C process and is 50% in Reed+A.C process. T-N removal rate by Amaryllis is average 2.6g/㎡·d, T-N removal rate by Reed is average 1.76g/㎡·d. T-P removal rate by Amaryllis is average 0.27g/㎡·d, T-P removal rate by Reed is average 0.25g/㎡·d. BOD removal rate constant with retention time is 1.4494(l/d), T-N removal rate constant is 0.5428(l/d), T-P removal rate constant is 0.5287(l/d)