Yao Yuan, Li Yun-Zhen, Guo Xu-Jing, Huang Tao, Gao Ping-Ping, Zhang Ying-Pei, Yuan Feng
Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, 610031, People's Republic of China.
Sichuan Academy of Environmental Sciences Sichuan, Chengdu, 610041, People's Republic of China.
Environ Sci Pollut Res Int. 2016 Jun;23(12):12237-45. doi: 10.1007/s11356-016-6435-5. Epub 2016 Mar 15.
Domestic wastewater was treated by five constructed wetland beds in series. Dissolved organic matter (DOM) collected from influent and effluent samples from the constructed wetland was investigated using fluorescence spectroscopy combined with fluorescence regional integration (FRI), parallel factor (PARAFAC) analysis, and two-dimensional correlation spectroscopy (2D-COS). This study evaluates the capability of these methods in detecting the spectral characteristics of fluorescent DOM fractions and their changes in constructed wetlands. Fluorescence excitation-emission matrix (EEM) combined with FRI analysis showed that protein-like materials displayed a higher removal ratio compared to humic-like substances. The PARAFAC analysis of wastewater DOM indicated that six fluorescent components, i.e., two protein-like substances (C1 and C6), three humic-like substances (C2, C3 and C5), and one non-humic component (C4), could be identified. Tryptophan-like C1 was the dominant component in the influent DOM. The removal ratios of six fluorescent components (C1-C6) were 56.21, 32.05, 49.19, 39.90, 29.60, and 45.87 %, respectively, after the constructed wetland treatment. Furthermore, 2D-COS demonstrated that the sequencing of spectral changes for fluorescent DOM followed the order 298 nm → 403 nm → 283 nm (310-360 nm) in the constructed wetland, suggesting that the peak at 298 nm is associated with preferential tryptophan fluorescence removal. Variation of the fluorescence index (FI) and the ratio of fluorescence components indicated that the constructed wetland treatment resulted in the decrease of fluorescent organic pollutant with increasing the humification and chemical stability of the DOM.
生活污水由五个串联的人工湿地床进行处理。利用荧光光谱结合荧光区域积分（FRI）、平行因子（PARAFAC）分析和二维相关光谱（2D - COS），对人工湿地进水和出水样品中收集的溶解有机物（DOM）进行了研究。本研究评估了这些方法检测荧光DOM组分光谱特征及其在人工湿地中变化的能力。荧光激发 - 发射矩阵（EEM）结合FRI分析表明，与类腐殖质物质相比，类蛋白质物质的去除率更高。对废水DOM的PARAFAC分析表明，可以识别出六种荧光组分，即两种类蛋白质物质（C1和C6）、三种类腐殖质物质（C2、C3和C5）和一种非腐殖质组分（C4）。类色氨酸C1是进水DOM中的主要组分。经过人工湿地处理后，六种荧光组分（C1 - C6）的去除率分别为56.21%、32.05%、49.19%、39.90%、29.60%和45.87%。此外，2D - COS表明，人工湿地中荧光DOM光谱变化的顺序为298 nm → 403 nm → 283 nm（310 - 360 nm），这表明298 nm处的峰与色氨酸荧光的优先去除有关。荧光指数（FI）和荧光组分比例的变化表明，人工湿地处理导致荧光有机污染物减少，同时DOM的腐殖化和化学稳定性增加。
