反渗透膜前预处理工艺去除渗滤液中DOM的光谱分析

考查反渗透(RO)膜处理渗滤液前所采用的预处理工艺对致膜有机污染物的去除效果，为RO膜预处理工艺的选择提供参考，采用同步荧光光谱、三维荧光光谱、紫外-可见全光谱对某垃圾焚烧厂渗滤液原液及其经“生化(UASB+A/O)+超滤”预处理工艺各级出水进行不同分子量分布区间的分析。同步荧光光谱表明，预处理工艺总体能有效去除波长在250～320 nm各分子量区间的以及波长>320 nm、分子量>1KDa的DOM;三维荧光光谱表明，预处理工艺总体能有效去除低激发波长类酪氨酸、低激发波长类色氨酸及高激发波长类色氨酸及分子量>1KDa的类富里酸和高激发波长类酪氨酸;紫外-可见全光谱表明，预处理工艺总体能有效去除分子量>1KDa带π—π*跃迁的DOM和各分子量区间的带多个共轭体系苯环结构的DOM。结果显示，将“生化(UASB+A/O)+超滤”组合工艺作为RO膜法处理焚烧厂渗滤液的预处理工艺时，还需加强同步荧光范围>320 nm、分子量<1 KDa、带π—π*跃迁的类富里酸及高激发波长类酪氨酸的去除。

Spectra Analysis of Dissolved Organic Matter in Pretreatment Process of Leachate Treated by Reverse Osmosis

In order to examine the removal of organic matter in the leachate which results in reverse osmosis (RO) membrane fouling, and to provides a reference to select appropriate pretreatment processes of RO, synchronous-scan fluorescence，three-dimensional excitation emission matrix fluorescence spectroscopic and UV-Vis spectrum of the dissolved organic matter (DOM) in different molecular weight range in effluent from each leachate process of “biochemical (UASB+A/O)and UF” pretreatment in some incineration plant were examined. The results of synchronous fluorescence spectra analysis showed that DOM in the wavelength range of 250～320 nm with all the molecular weight and in the wavelength>320 nm with molecular weight>1 KDa was removed obviously by the pretreatment processes. The results of three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectra showed that the pretreatment processes removed low-excitation wavelength tyrosine-like，low-excitation wavelength tryptophan-like and high-excitation wavelength tryptophan-like with all the molecular weight off，and fulvic-like matter and high-excitation wave length tyrosine-like with molecular weight>1 KDa effectively. The results of UV-Vis spectra analysis showed that the pretreatment processes removed DOM of molecular weight>1 KDa with π—π* transition and DOM of all molecular weight with conjugated system of the benzene ring structure. It was concluded that the removal of both fulvic-like matter and high-excitation wave length tyrosine-like with the wavelength>320 nm，molecular weight<1 KDa and with π—π* transition should be strengthened for controlling (RO) membrane fouling, when leachate was treated by RO with the pretreatment processes of “biochemical(UASB+A/O)and UF”.