溶氧（DO）是人工濕地（CW）污染物去除的關鍵因素，人工濕地中供氧不足通常被認為是人工濕地中限制處理效率的部分。在本研究中，在表面流動式人工濕地（FWS CW）中採用間歇曝氣系統，用以改善污染物的去除。然而，曝氣引起的擾動影響降低了DO的作用，為此增加了礫石牆單元以改善此情況，並有效地提高了處理效率。本研究設置了FWS CW（CW-B）作為對照組，槽體相同，水生植物皆為香蒲，分別種植在兩個FWS CW中，污水源自校園，其實驗結果可與具有曝氣和礫石牆的系統（CW-A）進行比較。 CWs水力負荷為0.144 m/d，有機負荷為5.34×10-4 kg·BOD/m2·d。根據結果，CW-B平均DO維持0.67 mg/L；透過CW-A特殊設計的曝氣系統，連續曝氣操作下DO達到2.44 mg/L。在BOD平均進流濃度為7.86 mg/L的情況下，CW-B的BOD去除率僅為8.9%，而間歇曝氣系統則提升至62.6％。氨氮（NH3-N）的平均進流濃度為15.3 mg/L，CW-B的去除率53.5％，而CW-A增加到96.1％，去除率顯著提高。進流中的亞硝酸鹽氮（NO2-N）的平均濃度，CW-A和CW-B皆維持在較低的出流濃度0.02?0.47 mg/L。然而，在連續曝氣操作下，硝酸鹽 - 氮（NO3 - -N）的平均濃度累積為6.0 mg/L，間歇曝氣下降至0.84 mg/L。總氮的去除率為56.4％?74.7％。 Dissolved oxygen (DO) plays a key factor in pollution removal of constructed wetlands (CW) and insufficient supply of oxygen in CWs is usually considered as the rate-limiting step in CWs. In this study, an intermittent aeration system was used in free water surface (FWS) CW to improve the removal of pollutants. However, a negative effect of the turbulence induced by aeration decreased the positive role of DO increase. A gravel wall was installed to damp this turbulent situation and increased the removal performance. A FWS CW (CW-B) was established as a control system whose experimental results could be compared to the system (CW-A) with aeration and gravel wall. The volumes of these CWs are the same. The emergent plants, cattail, are planted in both FWS CWs. The inflow came from the sewage system of university campus. CWs was operated with hydraulic loading, 0.144 m/d, and organic loading, 5.34×10-4 kg·BOD/m2·d, respectively. According to the results, averaged DO in CW-B maintains 0.67 mg/L; through a special designed aeration system in CW-A, DO raises to a level of 2.44 mg/L under continuous aeration operation. Under the averaged inflow concentration of biochemical demand (BOD) of 7.86 mg/L, BOD removal ratio of CW-B was only 8.9% and increased to 62.6% with intermittent aeration. With average influent concentration of ammonia-nitrogen (NH3-N) of 15.3 mg/L, removal ratio shows a very impressive improvement which increases from 53.5% in CW-B to 96.1% in CW-A with intermittent aeration. Averaged concentrations of nitrite-nitrogen (NO2─-N) in the inflow, CW-A and CW-B maintain in a relative low level, 0.02~0.47 mg/L. However, average concentration of nitrate-nitrogen (NO3─-N) accumulates as 6.0 mg/L under continuous aeration operation and decreases to 0.84 mg/L under intermittent aeration. The removal ratio of total nitrogen incerases from 56.4% to 74.7%.
