Abstract:

Three advanced flocculants were used to treat the biochemical treatment samples extracted from the landfill leachate. In order to explore the transformation characteristics of dissolved organic matter (DOM) in the process of coagulation, all the samples’ DOM from three stages were characterized by ultraviolet-visible spectra (UV-Vis), three dimensional fluorescence spectra (EEM) and Fourier transform ion cyclotron resonance electrospray mass spectrometry (ESI FT-ICR MS). UV-Vis spectra showed that the ratio of small molecules increased in water while both the humification degree and condensation degree reduced after coagulation. EEM suggested that the removal efficiency of protein and humic acid substances were very high after coagulation. FT-ICR MS indicated that there was a strong selectivity of flocculants for the removable DOM in different stages of coagulation. DOM in the final residual water was mainly smaller molecular weight, containing impurity atoms with low unsaturation, O/C<0.3, and H/C>1.5.

Key words: landfill leachate, biochemical unit effluent, dissolved organic matter (DOM), coagulation

摘要：

采用3种高新絮凝剂, 对采集自垃圾填埋场渗滤液处理工艺生化单元出水的样品进行3个阶段的深度混凝处理。采用紫外–可见光谱(UV-Vis)、三维荧光光谱(EEM)和电喷雾傅里叶变换离子回旋共振质谱(ESI FT-ICR MS)对3个阶段的样品中溶解有机物(DOM)进行表征, 以此来探究DOM在混凝过程中的去除转化特征。UV-Vis光谱分析结果表明, 经过混凝处理, 水中小分子物质的比例增大, 腐殖化程度降低, 缩合度降低。EEM分析结果表明, 经过混凝处理后, 类蛋白质和类腐殖酸物质的去除效果十分显著。FT-ICR MS分析结果表明, 在不同的混凝阶段, 絮凝剂去除的DOM有较强的选择性。最终出水残留的DOM主要是一些分子量较小、含有大量杂原子、具有较低不饱和度、O/C <0.3和H/C>1.5的物质。

关键词: 垃圾渗滤液, 生化单元出水, 溶解性有机物, 混凝