电芬顿降解苯乙酮过程中有机物三维荧光特征的变化规律

摘要

采用荧光光谱技术检测分析了苯乙酮在电芬顿处理过程中的三维荧光光谱特征变化规律,研究了苯乙酮的三维荧光特征及其指纹特征,对苯乙酮去除率和荧光峰强度变化进行线性拟合研究.结果表明,苯乙酮具有两个荧光峰,分别在λEx/Em=270/305 nm(Peak A)和λEx/Em=215/305 nm(Peak B)处,且荧光指纹特征(Peak A/Peak B比值)为1.22.在电芬顿降解的过程中,苯乙酮先分解为具有更强荧光强度的不饱和脂肪酸,而后进一步分解为荧光强度弱的短链小分子,导致荧光强度先增加而后又降低.在发射波长为285～375 nm范围内的二维荧光峰(激发波长为250 nm)与苯乙酮去除率具有很好的相关性,其能够高效地反映苯乙酮去除率在整个电芬顿处理过程中变化情况.%In the acetophenone degradation process by electro-Fenton, the variation trend of fluorescence characteristics of dissolved organic matter (DOM) in acetophenone synthetic wastewater was detected by excitation-emission matrix (EEM)fluorescence spectra The fluorescence spectra characteristics of acetophenone were studied, and the fitting line of fluorescence intensity and acetophenone removal efficiency was discussed in detail. The results show that the locations of the two fluorescence centers of acetophenone synthetic wastewater are at λEx/Em = 270/305 nm (Peak A) and λEx/Em = 215/305 nm (Peak B),respectively, and the ratio of Peak A/Peak B is 1.22. In the electro-Fenton treatment process, firstly, acetophenone was decomposed into unsaturated fatty acid which had stronger fluorescence intensity, further, it was degraded into short-chain small molecular compounds which have weaker fluorescence intensity. Therefore, the fluorescence intensity of synthetic wastewater was increased at first and decreased afterwards in the entire 180 rain electro-Fenton treatment process. The two-dimensional fluorescence peak at 285～375 nm of emission wavelength (at λEx = 250 nm) had a good linear relationship with the removal efficiency of acetophenone, therefore, it could reflect effectively the removal efficiency of acetophenone in the whole electro-Fenton treatment process.