| 摘要: | 本研究主要探討蜂巢式整流曝氣作用提升表面流式 (Free water surface , FWS)人工溼地(constructed wetland；CW)對污染降解效能的影響，並以校園廢水處理研究對象，研究中設計A、B系統分為曝氣及未曝氣二種FWS CW系統，而蜂巢式整流曝氣設置於FWS-A系統前端，藉由蜂巢式整流器抑制因曝氣作用所衍生之紊流，以減緩曝氣對FWS CW所產生之負面作用。本研究主要藉由生化需氧量(biochemical oxygen demand；BOD)、氨氮(ammonium-nitrogen；NH3-N)、亞硝酸鹽氮(nitrite-nitrogen)、硝酸鹽氮(nitrate-nitrogen)、總磷(total phosphorous；TP)等水質參數來評估曝氣整流對FWS CW汙染處理效能的影響。由本研究的研究結果可知進流的校園廢水在FWS-A系統單元加入蜂槽巢式整流曝氣系統後，觀察其平均溶氧有增加為2.60 mg/L，相對於對照組的平均溶氧0.93mg/L，此結果說明本研究的曝氣系統可以有效的提升系統的溶氧。另外實驗系統進流水的各項水質平均濃度分別為；BOD=11.44mg/L、NH3-N=29.82mg/L、TP=3.08mg/L，其有機汙染較低，使人工濕地汙染處理效能處於低效能區。BOD的去處效能則因為入流濃度比較低而影響其效能，但是BOD去除率仍然可以從FWS-B未曝氣對照組的27%增為整流曝氣FWS-A的68%。至於氨氮的去除效能，FWS-A系統則會因溶氧的增加而有明顯提升為82.0%，而未曝氣對照組之去除率僅28.8%。硝酸鹽氮則因人工溼地系統FWS-A的高溶氧環境抑制脫氮作用而有明顯累積，平均濃度約為2.50mg/L，亞硝酸鹽氮則沒有累積現象，其平均濃度約為0.14mg/L。FWS-B系統對照組的相對數據分別為0.32mg/L與0.18mg/L。FWS-A與FWS-B的TP平均出流濃度分別為2.74 mg/L與2.79 mg/L，其結果可發現曝氣作用對FWS人工溼地的總磷去除並沒有明顯的提升效果。綜合前述可以發現蜂巢式整流曝氣系統對人工濕地之影響主要可提升有機汙染與氨氮的去除效能。
The study focused on the promotion of pollution degradation of free water surface (FWS) constructed wetland (CW) by honeycomb rectification and artificial aeration in the treatment of campus wastewater. In the study, there were 2 systems; FWS-A and FWS-B system employed to the effects of pollutant removal enhanced by flow rectification and artificial aeration. The former installed honeycomb rectification and artificial aeration at the front of FWS-A system where the turbulence induced by artificial aeration could be damped by with the honeycomb rectification whereas FWS-B was the control experiment. To evaluate the performance of flow rectification and artificial aeration, the parameters; biochemical oxygen demand (BOD), ammonia-nitrogen (NH3-N), nitrite-nitrogen, nitrate-nitrogen, and total phosphorous (TP) were employed in this study. From the experimental results, it showed that artificial aeration in FWS-A system increased dissolved oxygen (DO) to 2.60 mg/L and it was only 0.93 mg/L in FWS-B without aeration. This result proved that the aeration system in FWS-A effectively improved the status of DO in FWS CW. The experimental results also showed that the parameter of water quality were BOD = 11.44 mg/L, NH3-N=29.82 mg/L, and TP= 3.08 mg/L, respectively. Although organic pollution of low concentration affected degradation performance of FWS CW, however, the BOD removal efficiency was 68% for FWS-A which was 27% higher than that of FWS-B. It implied that artificial aeration could effectively improve degradation efficiency of BOD even though the influent concentration was low.As for the removal efficiency of ammonia nitrogen, DO increase had significantly improved the removal efficiency of 28.8% in FWS-B without aeration to 82.0% in FWS-A with aeration and flow rectification. However, higher DO in the water environment might partially inhibit the nitrification process which was one of the most important processes of nitrate degradation. In the system of FWS-A, average concentration of nitrate-nitrogen in the effluent was 2.50 mg/L and only 0.32 mg/L in FWS-B. No accumulation of nitrite-nitrogen was found in FWS-A and FWS-B and the corresponding concentrations were 0.14 mg/L and 0.18 mg/L, respectively. The TP concentration in the effluent of FWS-A and FWS-B were averagely 2.74 mg/L and 2.79 mg/L, respectively. The aeration effect did not significantly enhance the removal of TP.Comprehensive results aforementioned proved the honeycomb rectification and artificial aeration system could effectively improve the removal efficiency of organic pollutants and ammonia-nitrogen for constructed wetland. No significant effect was found in the removal of TP. |
