State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu, 610059, People's Republic of China.
College of Environment and Ecology, Chengdu University of Technology, Chengdu, 610059, People's Republic of China.
Environ Sci Pollut Res Int. 2019 May;26(13):12867-12880. doi: 10.1007/s11356-019-04832-9. Epub 2019 Mar 19.
The issue of urban river pollution has attracted great attention due to high concentrations of ammonia nitrogen (NH-N) and low concentrations of dissolved oxygen (DO) in polluted water bodies. In order to investigate the effects of aeration-enhanced horizontal subsurface-flow constructed wetlands on polluted river water, unaerated aeration (NA), continuous aeration (CA), and intermittent aeration (IA) constructed wetlands were established. The purification effects of the wetland on various pollutants and the form of effluent nitrogen, influences of temperature on the removal rates of pollutants, the change of redox potential-oxidation reduction potential (ORP)-and the difference of dissolved oxygen (DO) between influent and effluent were investigated. The results indicated that aeration enhancement can improve the purification efficiencies of chemical oxygen demand (COD) and NH-N in constructed wetlands. The purification efficiencies of TN in IA and CA constructed wetlands were 91.9% and 53.7%, respectively, indicating that IA is the optimized aeration method for removal of various pollutants in wetlands. Changes of DO and ORP in effluent under IA and CA suggested improvement of aeration on the water environment. Meanwhile, DO was more sensitive to temperature compared with ORP. Additionally, a study of the nitrogen content in effluent suggested that the aeration method had a significant influence on the nitrogen content in effluent. The removal rates of both NH-N and TN degraded as the temperature dropped. The results also demonstrated that the removal rate of NH-N under aeration condition was more sensitive to temperature than that under NA condition and the effect of temperature on the removal rate of NH-N was greater than that of TN.
由于受污染水体中氨氮（NH-N）浓度高、溶解氧（DO）浓度低，城市河流污染问题受到了广泛关注。为了研究曝气增强水平潜流人工湿地对污染河水的影响，建立了未曝气曝气（NA）、连续曝气（CA）和间歇曝气（IA）人工湿地。研究了湿地对各种污染物的净化效果以及出水氮的形态、温度对污染物去除率的影响、氧化还原电位-氧化还原电位（ORP）的变化以及进出水之间溶解氧（DO）的差异。结果表明，曝气增强可以提高人工湿地中化学需氧量（COD）和 NH-N 的净化效率。IA 和 CA 人工湿地中 TN 的净化效率分别为 91.9%和 53.7%，表明 IA 是去除湿地中各种污染物的优化曝气方法。IA 和 CA 下出水 DO 和 ORP 的变化表明曝气改善了水环境。同时，与 ORP 相比，DO 对温度更为敏感。此外，对出水氮含量的研究表明，曝气方式对出水氮含量有显著影响。随着温度的降低，NH-N 和 TN 的去除率均下降。结果还表明，曝气条件下 NH-N 的去除率对温度的敏感性高于 NA 条件下，温度对 NH-N 去除率的影响大于 TN。
