ABSTRACT

Stormwater wetlands play a crucial role in the urban environment, providing many ecosystem services. In this work, a stormwater wetland was developed to study the effects on the removal of pollutants and the characteristics of dissolved organic matter (DOM) under different operating conditions, such as hydraulic retention time (HRT) and water depth. The results showed that the stormwater wetland exhibited excellent pollutant-removal performance, such as NH₄^+_N, TN, TP, COD, and suspended solids (SS). The removal rates for these substances reached 79.1%, 73.2%, 89.0%, 84.3%, 80.4%, and 73.77, respectively, with 24 h of HRT and 15 cm of water depth. An increase in HRT can improve the removal rates of TN, TP, COD, and TOC. The removal rates for these parameters decreased with increasing water depth, though, except for TP; the UV–VIS spectral parameters indicated that an obvious decrease occurred in the degrees of humification and aromaticity of DOM with increasing HRT and water depth after the stormwater wetland treatment. Parallel factor (PARAFAC) analysis identified six fluorescent components (one combination of freshly produced biologically labile matter and a tryptophan-like component, one fulvic-like, one humic-like, and three tryptophan-like), whose fluorescence intensity was weakened after the stormwater wetland treatment. The lowest intensity appeared with 24 h of HRT and 15 cm of water depth. This study could be beneficial for understanding and managing stormwater wetlands, thus alleviating the impacts of pollutants on urban environments.

摘要

雨水湿地在城市环境中发挥着至关重要的作用，提供许多生态系统服务。在这项工作中，开发了一个雨水湿地，以研究水力停留时间 (HRT) 和水深等不同操作条件下对污染物去除和溶解有机物 (DOM) 特性的影响。结果表明，雨水湿地表现出优异的污染物去除性能，如NH ₄ ^+_N、TN、TP、COD 和悬浮固体 (SS)。这些物质的去除率分别达到 79.1%、73.2%、89.0%、84.3%、80.4% 和 73.77，水力停留时间为 24 小时，水深为 15 厘米。增加 HRT 可以提高 TN、TP、COD 和 TOC 的去除率。但是，除 TP 外，这些参数的去除率随着水深的增加而降低；UV-VIS 光谱参数表明，随着雨水湿地处理后 HRT 和水深的增加，DOM 的腐殖化程度和芳香性明显降低。平行因子 (PARAFAC) 分析确定了六种荧光成分（一种是新产生的生物不稳定物质和一种色氨酸样成分的组合，一种是黄腐酸样成分，一种是腐殖酸样成分，三种是色氨酸样成分），雨水湿地处理后其荧光强度减弱。最低强度出现在 24 小时 HRT 和 15 厘米水深时。这项研究可能有助于了解和管理雨水湿地，从而减轻污染物对城市环境的影响。