Simulated photo-degradation of dissolved organic matter in lakes revealed by three-dimensional excitation-emission matrix with regional integration and parallel factor analysis

Publication date: Available online 18 December 2019Source: Journal of Environmental SciencesAuthor(s): Jin Zhang, Fanhao Song, Tingting Li, Kefu Xie, Huiying Yao, Baoshan Xing, Zhongyu Li, Yingchen BaiAbstractSimulated photo-degradation of fluorescent dissolved organic matter (FDOM) in Lake Baihua (BH) and Lake Hongfeng (HF) was investigated with three-dimensional excitation-emission matrix (3DEEM) fluorescence combined with the fluorescence regional integration (FRI), parallel factor (PARAFAC) analysis, and multi-order kinetic models. In the FRI analysis, fulvic-like and humic-like materials were the main constituents for both BH-FDOM and HF-FDOM. Four individual components were identified by use of PARAFAC analysis as humic-like components (C1), fulvic-like components (C2), protein-like components (C3) and unidentified components (C4). The maximum 3DEEM fluorescence intensity of PARAFAC components C1–C3 decreased by about 60%, 70% and 90%, respectively after photo-degradation. The multi-order kinetic model was acceptable to represent the photo-degradation of FDOM with correlation coefficient (Radj2) (0.963–0.998). The photo-degradation rate constants (kn) showed differences of three orders of magnitude, from 1.09× 10−6 to 4.02 × 10−4 min−1, and half-life of multi-order model (T1/2n) ranged from 5.26 to 64.01 min. The decreased values of fluorescence index (FI) and biogenic index (BI), the fact that of percent fluorescence response parameter of Region I (PI,n)...
Source: Journal of Environmental Sciences - Category: Environmental Health Source Type: research