Department of Chemistry, Western Washington University, 516 High Street, Bellingham, WA, 98229, USA.
Schmid College of Science and Technology, Chapman University, One University Drive, Orange, CA, 92780, USA.
Chemosphere. 2020 May;247:125906. doi: 10.1016/j.chemosphere.2020.125906. Epub 2020 Jan 13.
Many removal mechanisms in treatment wetlands involve absorption to organic matter. Optical properties and DOC levels of waters entering and exiting 4 treatment wetland systems in Orange County, Southern California, were measured to characterize the dissolved organic matter pool. Average DOC levels decreased between the inlets and outlets, except for Forge Street (FS), which increased. For 3 wetlands, absorption coefficients decreased between inlet and outlet; the exception was FS, which increased. Average spectral slopes for the inlets and outlets were similar. Average intensities of terrestrial humic peaks A and C from 3D EEM fluorescence spectra decreased between the inlets and outlets for most wetlands. No EEM protein peaks were observed. Average flu/abs ratios for inlets and outlets were similar (high point for FS inlet excluded), suggesting chromophoric dissolved organic matter (CDOM) of a similar composition was present. The average FI value for the inlets and outlets was ∼1.5, consistent with terrestrial sources of CDOM. Average BIX values for the inlets and outlets were ∼0.8, suggesting limited contributions from autochthonous production of CDOM. Dominant plant species in the wetlands were cattail and bulrush. Humic peaks A and C, along with protein peaks, were observed in plant leachates. Protein peaks rapidly degraded with solar simulator irradiation. Results indicate that most of the wetlands are a net sink for CDOM, possibly due to absorption to sediments. The FS wetland appears to have a source of non-CDOM optically active organic carbon, possibly from a pollutant.
许多处理湿地中的去除机制涉及对有机物的吸收。为了描述溶解有机物质库，测量了进入和离开加利福尼亚州奥兰治县 4 个处理湿地系统的水的光学性质和 DOC 水平。除 Forge 街（FS）外，入口和出口之间的平均 DOC 水平降低；FS 增加了。对于 3 个湿地，入口和出口之间的吸收系数降低；FS 是例外，它增加了。入口和出口处的平均光谱斜率相似。来自 3D EEM 荧光光谱的陆地腐殖质峰 A 和 C 的平均强度在大多数湿地的入口和出口之间降低。没有观察到 EEM 蛋白质峰。入口和出口处的平均荧光/吸收比值相似（FS 入口的高点除外），表明存在组成相似的发色溶解有机物质（CDOM）。入口和出口处的平均 FI 值约为 1.5，与 CDOM 的陆地来源一致。入口和出口处的平均 BIX 值约为 0.8，表明 CDOM 自生源产生的贡献有限。湿地中的优势植物物种是香蒲和芦苇。在植物浸出物中观察到腐殖质峰 A 和 C 以及蛋白质峰。蛋白质峰在太阳模拟器辐照下迅速降解。结果表明，大多数湿地是 CDOM 的净汇，可能是由于对沉积物的吸收。FS 湿地似乎有非 CDOM 光活性有机碳的来源，可能来自污染物。
