人工湿地处理富营养化水体潜力研究：来自太湖的证据

李林峰、李英毫、比斯瓦斯、年跃刚、蒋高明*

*通讯作者

中国科学院植物研究所植被与环境变化重点实验室

中国环境科学研究院湖泊工程技术中心

生物资源技术，2008，99 (6)：1656-1663（影响因子5.807，SCI引文197）

采用垂直潜流（VSF）、水平潜流（HSF）和自由水面流（FWS）三个平行的中试人工湿地单元，研究其净化中国太湖富营养化水体之能力。每次处理时，湖水以0.64 m d^-1的水力负荷率连续泵入人工湿地。一年运行结果表明，化学需氧量（COD）、氨氮（NH₄⁺-N）、硝态氮（NO₃^--N）、总氮（TN）和总磷（TP）平均去除率分别为17-40%、23-46%、34-65%、20-52%和35-66%。除NH₄⁺-N外，VSF和HSF对养分去除潜力相似，前者比后者高14%。然而，在高水力负荷下，FWS湿地表现出比VSF和HSF最小的效果。VSF（0.056mg L^-1）和HSF（0.052mg L^-1）出水口平均总磷浓度接近国家三级（湖泊、水库0.05mg L^-1）水质标准。湿地植物（香蒲）在三种人工湿地中生长良好。研究发现，植物吸收和贮藏是三种人工湿地氮磷去除的重要因素。然而，收获地上生物量贡献了FWS湿地总氮、总磷去除量的20%和57%，而在VSF和HSF中，通过收获地上部生物量总氮、总磷去除量仅为5%和7%，分别占湿地总氮、总磷去除量的14%和17%。结果表明，人工湿地对富营养化太湖水体具有较好的处理效果。如果考虑条件限制，在较高水力负荷下，垂直潜流(VSF)和水平潜流(HSF)比自由水面流(FWS)人工湿地更为适合。

Potential of constructed wetlands in treating the eutrophic water: Evidence from Taihu Lake of China

Li Linfeng, Li Yinghao, Biswas Dilip Kumar, Nian Yuegang & Jiang Gaoming*

*Correspondence author

Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, PR China

Lake Engineering Technology Center of Chinese Academy of Environmental Sciences

Bioresource Technology, 2008, 99 (6):1656-1663 (IF=5.807, SCI citation 197)

Three parallel units of pilot-scale constructed wetlands (CWs), i.e., vertical subsurface flow (VSF), horizontal subsurface flow (HSF) and free water surface flow (FWS) wetland were experimented to assess their capabilities in purifying eutrophic water of Taihu Lake, China. Lake water was continuously pumped into the CWs at a hydraulic loading rate of 0.64 m d^-1 for each treatment. One year's performance displayed that average removal rates of chemical oxygen demand (COD), ammonia nitrogen (NH₄⁺-N), nitrate nitrogen (NO₃^--N), total nitrogen (TN) and total phosphorous (TP) were 17-40%, 23-46%, 34-65%, 20-52% and 35-66%, respectively. The VSF and HSF showed statistically similar high potential for nutrients removal except NH₄⁺-N, with the former being 14% higher than that of the latter. However, the FWS wetland showed the least effect compared to the VSF and HSF at the high hydraulic loading rate. Mean effluent TP concentrations in VSF (0.056 mg L^-1) and HSF (0.052 mg L^-1) nearly reached Grade III (0.05 mg L^-1 for lakes and reserviors) water quality standard of China. Wetland plants (Typha angustifolia) grew well in the three CWs. We noted that plant uptake and storage were both important factors responsible for nitrogen and phosphorous removal in the three CWs. However, harvesting of the above ground biomass contributed 20% N and 57% P of the total N and P removed in FWS wetland, whereas it accounted for only 5% and 7% N, and 14% and 17% P of the total N and P removed in VSF and HSF CWs, respectively. Our findings suggest that the constructed wetlands could well treat the eutrophic lake waters in Taihu. If land limiting is considered, VSF and HSF are more appropriate than FWS under higher hydraulic loading rate.