| 摘要: | 景觀水池的水質常因營養鹽中氮、磷含量過高而導致藻類大量繁殖，因此本研究則應用微型潛流式人工溼地 (subsurface constructed wetland) 的概念，進行淨化景觀水池水質之含氮污染物去除的可行性評估。本實驗系統包含上下水池以及水道，其水道則依據潛流式人工溼地的概念進行佈置。
本研究共進行四批次之實驗，均於水池中加入固定量之氯化銨，觀察其污染物的淨化情形。研究結果顯示，當環境溫度平均分別為17.9℃、21.9℃、27.0℃、30.8℃時，溫度對氨氮進行硝化作用的影響不大，而亞硝酸鹽氮與硝酸鹽氮則會受到溫度較大的影響，致使各批次實驗將水質淨化至背景值的時間亦不相同，其各批次實驗淨化水質所需的時間分別為72天、42天、35天、17天，因此溫度的上升將有助於提高降解的反應速度。
本研究另進行NO3--N的去除率探討，共進行三批次實驗。第一、二次實驗之NO3--N初始濃度為0.65 mg/L，其上下池及水道對於NO3--N的平均去除率分別為31.5%、32.3%、95.7%；第三次實驗之NO3--N初始濃度為2.7 mg/L，其上下池及水道對於NO3--N的平均去除率分別為 0%、14.9%、92.8%。综合結果顯示水道較不受NO3--N的濃度變化而影響其淨化效能，且均能保持90%以上的去除效果，此亦間接證實應用潛流式人工溼地於景觀水池對於容易累積在水池當中的NO3--N有顯著的去除效能。
The present research aimed to study the application of subsurface constructed wetland on the water purification of landscaping pond that containing nitrogen. The experimental system consists of upper pool (UP) and lower pool (DP) and waterways connected UP and DP which was designed according to the concept of subsurface constructed wetland layout.
In the initial stage, four batches of experiments were conducted to observe degradation of nitrogen contained pollutant under different atmospheric temperature. To evaluate the efficiency of the system, certain amount of ammonium chloride were added into the pool and the samples were taken to determine the concentration of ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen. The obtained results showed that when the temperature was 17.9�C, 21.9�C, 27.0�C and 30.8�C, the effect of temperature was not obvious in the nitrification of ammonia nitrogen. However, the effect of temperature on nitrite and nitrate was significant. The reaction time for water purification was not the same in each batch of experiment. Four experimental batches needed 72 days, 42 days, 35 days and 17 days for water purification, respectively. In addition, increasing temperature can improve the degradation rate.
This study also performed three more batch experiments to explore the NO3- - N removal efficiency. The first and second batches used 0.65 mg/L of initial NO3- - N concentration. Results showed that the average NO3- - N removal rates were 31.5%, 32.3% and 95.7% at upper pool, lower pool and waterway, respectively. The third batch was used 2.7 mg/L of NO3- - N and the results revealed that at upper pool, lower pool and waterway, the average removal rates was 0%, 14.9% and 92.8%, correspondingly. The experimental results also showed that the purification efficiency of waterways was not obviously effect by higher concentration of NO3- - N which was more than 90% removal efficiency. From the experimental results, it can be concluded that the application of subsurface constructed wetland on landscaping pond was able to removal the NO3- - N from the pond. |
