Characteristic Regions of the Fluorescence Excitation-Emission Matrix (EEM) To Identify Hydrophobic/Hydrophilic Contents of Organic Matter in Membrane Bioreactors
Characteristic Regions of the Fluorescence Excitation-Emission Matrix (EEM) To Identify Hydrophobic/Hydrophilic Contents of Organic Matter in Membrane Bioreactors
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荧光激发-发射矩阵 (EEM) 的特征区域用于识别膜生物反应器中有机物的疏水/亲水内容
DOI：
10.1021/acs.est.8b02684
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发表时间：
2018
影响因子：
11.4
通讯作者：
Huang Xia
中科院分区：
文献类型：
--
作者：
Xiao Kang;Shen Yuexiao;Liang Shuai;Tan Jihua;Wang Xiaomao;Liang Peng;Huang Xia
系统研究了膜生物反应器（MBR）中溶解性有机物（DOM）的荧光激发-发射矩阵（EEM）与亲水/疏水组成之间的相关性。在10个全规模MBR样品的基础上，我们使用EEM荧光商（FQ）方法对不同组分进行点对点比较，并通过Wilcoxon符号秩检验获得疏水/亲水荧光团分布图。疏水性酸/碱（HOA/HOB）集中在低波长区域[激发波长（Ex）< 235 nm]，而亲水性物质（HIS）富集在Ex > 235 nm区域[特别是发射波长（Em）= 300-360 nm]。定量分析发现，EEM区域对全波长荧光的贡献与DOM的疏水/亲水比例显著相关，HOA和HIS的Pearson系数分别为0.94和0.78（p< 0.01）。我们建立了一个线性回归模型，显示了HOA比例作为EEM区域贡献的函数，在（Ex，Em）=（200-285，340-465 nm），R2 = 0.876，通过留一交叉验证和Monte Carlo模拟验证。这项研究表明，统计上的疏水性依赖的荧光性质在不同的MBR，它可能会被应用到提供一个快速估计的疏水/亲水组成的DOM在废水处理系统的基础上EEM监测。
This study systematically investigated the correlations between fluorescence distributions characterized by the excitation–emission matrix (EEM) and hydrophobic/hydrophilic composition of dissolved organic matter (DOM) in membrane bioreactors (MBRs). On the basis of samples from 10 full-scale MBRs, we performed point-to-point comparisons among different components using an EEM fluorescence quotient (FQ) method and obtained a hydrophobic/hydrophilic fluorophore distribution map via Wilcoxon signed rank test. Hydrophobic acids/bases (HOA/HOB) concentrated in the low-wavelength region [excitation wavelength (Ex) < 235 nm], while hydrophilic substances (HIS) were enriched in the region of Ex > 235 nm [especially with emission wavelength (Em) = 300–360 nm]. Quantitatively, EEM regional contribution to whole wavelength fluorescence was found to significantly correlate with the hydrophobic/hydrophilic proportions of DOM, with Pearson’s coefficients of 0.94 and 0.78 (p< 0.01) for HOA and HIS, respectively. We established a linear regression model showing the HOA proportion as a function of the EEM regional contribution at (Ex, Em) = (200–285, 340–465 nm), withR2= 0.876, which was validated via leave-one-out cross-validation and Monte Carlo simulation. This study shows a statistically hydrophobicity-dependent fluorescence property across different MBRs, and it might be applied to provide a quick estimation of hydrophobic/hydrophilic composition of DOM in wastewater treatment systems based on EEM monitoring.