| Summary: | 碩士 === 國立屏東科技大學 === 土壤與水工程國際碩士學位學程 === 105 === In this study, constructed wetland (CW) established with a matrix of soil, sand together with gravel and planted with Cyperus involucratus was used to investigate the ability to remove organic matters (OMs) and tetracycline (TC) in water. The performance of CW was evaluated by varying initial concentrations of target compounds and hydraulic retention times (HRTs). Overall, OMs removal efficiencies of 55.2 - 80.8%, 28.1 - 71.9% and 72.1 - 79.7% for UV 254, DOC and sCOD, respectively, were achieved under continuous flow condition after a retention time of 1 day. Performance of CW with higher initial DOC concentration achieved better removal efficiencies, indicating that CW is a promising system in treating water with high amount of OMs. Furthermore, the removal efficiency of OMs in HRT-1day was nearly similar to that in HRT-2day which was recorded from this study. However, HRT played an important role in removal of ammonia in this experiment. The removal efficiency of NH3-N increased considerably from
61.7% to 73.0% with the change of HRT from 1 day to 2 days, resulting in the fact that the removal of ammonia in water by using CW needs a long time to get the complete treatment. CW also showed an excellent performance in removing TC in water, especially in the first two hours of the operating period through absorption process. Last but not least, with the expectation of using photocatalysis as the post treatment to improve the water quality in the effluent after CW treatment, the findings of this research showed an improvement in effluent water quality, presented by the increase in removal efficiency of OMs of combined system compared to that of CW alone. The photocatalytic reactor equipped with two UVA lamps, which emitted radiation wavelength between 315 nm and 400 nm, and photocatalyst used in this experiment was TiO2/ α-Al2O3 with an amount of 20 g. Although there was an enhancement in effluent water quality, the increase in removal efficiency of combined system compared to that of CW alone was a minor. Therefore, further research on combination of CW and photocatalytic oxidation needs to be done to enhance the performance of this combined system. Despite the fact that further tests are required to get the better results, this study points to the possible application of these low cost water treatment systems for dealing with OMs and TC in water.
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