| 摘要: | 本研究係以一模擬人工濕地為研究對象，係依表面流式人工濕地(Free water surface CW, FWS) 串聯潛流式人工濕地(Sub-surface flow CW, SSF) 概念來設計，在表面流人工濕地單元觀察未曝氣及增加曝氣提高水中溶氧對污染物去除效益之影響。在諸多水或廢水處理方法中，人工濕地系統(Constructed wetlands system，CW) 是以人為方式操作和控制濕地之各種環境參數，並利用生態自然系統淨化水質的一種生態工程技術。研究中設計A、B系統所用之污水為人工合成污水，試程分為未曝氣及曝氣二個試程，而曝氣試程設置於A系統FWS單元前端。人工合成污水其總磷(TP)、氨氮(NH3-N)、生化需氧量(BOD)起始濃度分別為4.11 mg/L、37.33 mg/L、113 mg/L，在A系統未曝氣試程中總去除率為71.04%、68.30%、97.99%，曝氣試程總去除率為57.96%、39.96%、97.20%。其人工濕地結果顯示，BOD在未曝氣試程A、B系統總去除率差異不大，且在A系統增加曝氣試程後與B系統總去除率皆達到95%以上，顯示增加曝氣系統對於BOD去除污染物效能無太大影響；氨氮污染物在未曝氣試程總去除率差異不大，但在A系統增加曝氣後期總去除率與B系統相比，其結果沒有預期好，可能是因為曝氣期間氣溫越來越低，導致曝氣系統在冬天影響不大，也可能是曝氣系統為槽體內曝氣，而曝氣使得水槽產生擾動污染物產生物理作用，導致曝氣試程去除率較差；總磷在A、B系統未曝氣試程及A系統曝氣後與B系統總去除率相比較，去除率差異不大，顯示總磷汙染物去除機制還是以植物吸收為主，因此，增加曝氣系統對於總磷污染物去除無太大影響。
This research is aimed to investigate the effect of artificial aeration on the pollution removal of constructed wetlands CW). The experiments are mainly carried out in the free water surface (FWS) CW which is following a subsurface flow (SSF) CW. An evaluation of artificial aeration effects is based on the comparisons of experimental system A and control system B which operates under the same condition except without aeration. The aeration unit is installed in the beginning part of FWS CW of system A. To assess the removal efficiencies, various water quality parameters, such as ammonia-Nitrogen (NH3-N), Biochemical Oxygen Demand (BOD), and total Phosphate (TP), are monitored during the experimental period.From experimental results of system A & B, the averages of TP, BOD, and NH3-Nin the influent are 4.11, 37.33, 113 mg/L. The corresponding averages of pollutants removal of system A during non-aeration test are 71.04%, 68.30% and 97.99%, respectively. When the artificial aeration is operating, the averages of removal rates become 57.96%, 39.96% and 97.20%. It reveals that aeration in FWS of system A decreases the removal rate. The declination is resulted from a decrease of water temperature and disturbance induced by artificial aeration. For further study the aeration effect on the pollution removal, water quality parameters of system A and B are compared. From the results of BOD, there is no obvious discrepancy and no positive effect of aeration is found in the BOD removal. However, a lower removal is observed for NH3-N. It indicates that the disturbance induced by aeration will release NH3-N from the sediment and lower the removal of NH3-N. However, there is no obvious discrepancy of TP removal between system A and B. It is because that the main removal mechanism of TP is the adsorption of plants, which will not affect by aeration. |
