State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
J Environ Sci (China). 2012;24(4):596-601. doi: 10.1016/s1001-0742(11)60804-8.
Three lab-scale vertical-flow constructed wetlands (VFCWs), including the non-aerated (NA), intermittently aerated (IA) and continuously aerated (CA) ones, were operated at different hydraulic loading rates (HLRs) to evaluate the effect of artificial aeration on the treatment efficiency of heavily polluted river water. Results indicated that artificial aeration increased the dissolved oxygen (DO) concentrations in IA and CA, which significantly favored the removal of organic matter and NH(4+)-N. The DO grads caused by intermittent aeration formed aerobic and anoxic regions in IA and thus promoted the removal of total nitrogen (TN). Although the removal efficiencies of COD(Cr), NH(4+)-N and TN in the three VFCWs all decreased with an increase in HLR, artificial aeration enhanced the reactor resistance to the fluctuation of pollutant loadings. The maximal removal efficiencies of COD(Cr), NH(4+)-N and total phosphorus (TP) (i.e., 81%, 87% and 37%, respectively) were observed in CA at 19 cm/day HLR, while the maximal TN removal (i.e., 57%) was achieved in IA. Although the improvement of artificial aeration on TP removal was limited, this study has demonstrated the feasibility of applying artificial aeration to VFCWs treating polluted river water, particularly at a high HLR.
三种实验室规模的垂直流人工湿地（VFCWs），包括非曝气（NA）、间歇曝气（IA）和连续曝气（CA），在不同水力负荷率（HLR）下运行，以评估人工曝气对处理高污染河水的效果。结果表明，人工曝气增加了 IA 和 CA 中的溶解氧（DO）浓度，这显著有利于有机物和 NH（4）+-N 的去除。间歇曝气引起的 DO 梯度在 IA 中形成了好氧和缺氧区，从而促进了总氮（TN）的去除。尽管三种 VFCWs 的 COD（Cr）、NH（4）+-N 和 TN 的去除效率均随 HLR 的增加而降低，但人工曝气增强了反应器对污染物负荷波动的抵抗力。在 19 cm/day 的 HLR 下，CA 中的 COD（Cr）、NH（4）+-N 和总磷（TP）的最大去除效率（分别为 81%、87%和 37%），而 IA 中的最大 TN 去除效率（57%）。尽管人工曝气对 TP 去除的改善有限，但本研究证明了在处理污染河水时应用人工曝气的可行性，尤其是在高 HLR 下。
