Fenton深度处理渗滤液时DOM结构变化

Structural transformation of dissolved organic matters in leachate after advanced Fenton treatment

摘要:

为了提高垃圾渗滤液中有机物在深度处理阶段的去除率,通过Fenton高级氧化技术,研究垃圾渗滤液SBR处理的出水在Fenton氧化过程前后溶解性有机物(DOM)结构和官能团变化规律,利用XAD-8/XAD-4树脂将水样中的溶解性有机物(DOM)分级为疏水性有机酸(HPO-A)、疏水性中性有机物(HPO-N)、过渡亲水性有机酸(TPI-A)、过渡亲水性中性有机物(TPI-N)和亲水性有机物(HPI),HPO-A和HPO-N为SBR出水DOM中主要组分(占到其DOC总含量的67%).经Fenton高级氧化后,DOM的总去除率为60.01%,其荧光光谱特性发生了明显变化,DOM五个组分的SUVA均呈上升趋势,说明氧化过程中5个组分的芳香性增强.在傅立叶红外光谱(FT-IR)分析中,HPO-A和TPI-A均显示了很强的羧酸基团吸收峰,而HPO-N和TPI-N的谱图十分相近,有较强的脂肪烃吸收峰.Fenton反应后,HPO-A和TPI-A中的O—H、—COOH的含量降低,而苯环、C—O和CO含量升高,还生成了1-酰胺.

Abstract:

In order to increase the organic matter removal rate during advanced treatment,the characteristics and transformation of dissolved organic matter(DOM) in SBR effluent during the Fenton oxidation in laboratory scale were studied. DOM was fractionated using XAD resins into 5 fractions: hydrophobic acid(HPO-A),hydrophobic neutral(HPO-N),transphilic acid(TPI-A),transphilic neutral(TPI-N) and hydrophilic fraction (HPI). The HPO-A and HPO-N occupy 67% of the DOM. Dissolved organic carbon(DOC) was removed by 60. 01% and the significant changes in fluorescence properties of DOM were observed during Fenton oxidation. The SUVA of all the five fractions increased,which showed the enrichment of aromatic structures. The DOM fractions also exhibited different changes in Fourier-transform infrared( FT-IR) spectra characteristics during Fenton oxidation. It indicated that carboxylic acids existed as a major functional group in the SBR effluent HPO-A and TPI-A. HPO-N and TPI-N were similar,with greater hydrocarbon character and less carboxylic acid character than other fractions. Fenton oxidation resulted in the enrichment of C—O,C O and aromatic structures and the decreased content of O—H and —COOH functional groups in DOM. On the other hand,the production of amide-1 functional groups occurred.