不同垃圾渗滤液组合处理工艺中DOM的变化特征

为了快速表征垃圾渗滤液处理过程中有机物的特性变化,分别采用紫外光谱和三维荧光光谱对2种垃圾渗滤液处理工艺不同单元溶解性有机物(DOM)的变化进行了系统分析。结果表明,二级RO和厌氧+好氧+MBR+NF+RO工艺对渗滤液COD和NH3-N的去除率分别为98.7%、99.0%和98.8%、98.6%。随着处理过程的进行,2个处理工艺中DOM的SUVA254、E253/E203分别由0.74、0.33和0.46、0.12下降至0.015、0.014和0.010、0.012,有机物的芳香性和不饱和性下降,脂肪链芳香烃化合物开始增加。不同处理阶段渗透液DOM三维荧光光谱表明,随着处理过程的进行,类富里酸和类蛋白物质的含量逐渐下降,芳构化程度开始降低。其中二级RO系统对渗滤液中类富里酸物质的去除效果较好,而厌氧-好氧-MBR-NF-RO工艺中,类酪氨酸物质主要通过微生物降解去除,NF和RO膜对类富里酸和类腐殖酸物质的截留效果较好。

Characteristics of dissolved organic matters from different landfill leachate treatment processes

The ultraviolet spectra and fluorescence spectra are used to rapidly reveal the variation of dissolved organic matter (DOM) characteristics in two combination processes including two-pass RO (process A) and anaeration +aeration +MBR+ NF+ RO (process B) for landfill leachate treatment. The results indicated that the removal rates of COD and NH₃-N were 98.7% and 99.0% for process A, and 98.8% and 98.6% for process B, respectively. The ultraviolet spectra analysis showed that aromatic and unsaturated compounds slightly decreased and the stability of aromatic compounds with aliphatic chain was weaken in those processes. These results were confirmed by the values of SUVA₂₅₄ and E₂₅₃/E₂₀₃ decreasing from 0.74 and 0.33 to 0.015 and 0.014 in process A, and from 0.46 and 0.12 to 0.010 and 0.012 in process B. Moreover, the 3DEEM of DOM indicated that the concentrations of fulvic-like and protein-like compounds decreased and the degree of aromatization was reduced. The further analysis suggested that a good removal efficiency of fulvic-like compounds by two-pass RO system was achieved in process A. Tyrosine-like compounds were mainly removed by microbial degradation, and a good retention effect of fulvic-like compounds and humic-like compounds could be obtained by NF-RO in process B.