复合生态净化系统阻控入湖水体污染物效果分析

[目的]有效解决城市景观湖泊入湖水体污染物阻控措施中单级人工湿地系统受氧环境限制、多级串联人工湿地系统基质填充量大、易堵塞的问题。[方法]在微曝气复合浮床系统、单级人工湿地系统的基础上构建好氧-缺氧型复合生态净化系统。在HRT均设定为2 d,连续运行24 d的情况下,对比研究了对照组、人工湿地系统、复合浮床系统、复合生态净化系统对模拟入湖水体COD、TN、NH4^+-N和TP的去除效果。[结果]对照组、人工湿地系统、复合浮床系统、复合生态净化系统对COD、NH4^+-N、TP的去除效果存在显著差异,各系统对COD的平均去除率分别为13.59%、35.02%、45.30%、70.71%,对NH4^+-N的平均去除率分别为11.22%、31.14%、85.89%、80.59%,对TP的平均去除率分别为2.77%、57.84%、37.51%、74.60%;人工湿地系统、复合浮床系统对TN去除效果差异不显著,但与对照组、复合生态净化系统存在显著差异,各系统对TN的平均去除率分别为30.98%、32.75%、8.13%、60.07%。[结论]复合生态净化技术后期各项出水指标可以达到《地表水环境质量标准》(GB3838-2002)Ⅴ类水及以上标准,运行相对稳定,抗冲击负荷较强,且可以改善复合浮床系统中反硝化能力受到抑制及沉积磷污染物反释状况。该研究结果可为生态阻控城市景观湖泊外源污染物提供参考。

Composite Ecological Purification System for Removing Contaminants in Water Flowing into Recreational Lakes

[Objective]Wetland is an effective technology to remediate contaminated water and has been used to remove pollutants from waters flowing into recreational latkes in urban areas. However, a single small wetland might not be effective enough while multiple wetlands need a large amount of matrix. The purpose of this paper is to present an improved composite ecological purification system to resolve these problems.[Method]The proposed composite ecological purification system was an aerobic-anoxic, and it was constructed based on the micro-aerated single floating bed. We experimentally tested system. During the experiment, we measured removal COD, total nitrogen(TN), NH4^+ and total phosphorus(TP) from water flowing into a lake, and compared the results with results obtained from the control, a constructed wetland and a composite floating bed system. In all treatments, the hydraulic retention time was 2 days and the experiments were running for 24 days[Result]For the constructed wetland system, the composite floating bed system and the composite ecological purification system, their removal efficiency was 13.59%, 35.02%, 45.30% and 70.71% respectively for COD, 11.22%, 31.14%, 85.89% and 80.59% respectively for NH4^+, 2.77%, 57.84%, 37.51% and 74.60% respectively for TP, and 30.98%, 32.75%, 8.13% and 60.07% respectively for TN. The proposed system significantly improved TN removal compared to the control.[Conclusion]The effluent from the system met the Class V standard for Surface Water Environmental Quality(GB 3838-2002). Operation of the proposed system was more stable and robust even under instant load increase. It improved denitrification and reduced phosphorus release. The results have implications for ecological control of exogenous pollutants in urban recreational lakes.