溶解性有机物组成对混凝及类芬顿工艺处理垃圾渗滤液膜浓缩液的影响

为探究溶解性有机物（DOM）组成对工艺处理效率的影响,以不同来源的两种垃圾渗滤液膜浓缩液为对象,分别采用混凝、UV芬顿和电芬顿工艺进行处理,比较和分析不同工艺处理后两种渗滤液膜浓缩液的DOM去除差异。结果表明,在试验条件下,混凝、UV芬顿、电芬顿工艺降解1#垃圾渗滤液膜浓缩液（经“膜生物反应（MBR）+纳滤（NF）”处理）的溶解性有机碳（DOC）去除率分别达42%、66%、62%,降解2#垃圾渗滤液膜浓缩液（经“缺氧/好氧（A/O）+反渗透（RO）”处理）的DOC去除率分别达20%、60%、52%。采用三维荧光光谱结合平行因子法（EEM-PARAFAC）和液相色谱-有机碳测定仪（LC-OCD）进一步分析,结果表明,两种渗滤液浓缩液的DOC去除差异与DOM组成差异有关。LC-OCD定量检测结果表明,相比2#渗滤液膜浓缩液（52%）,1#渗滤液膜浓缩液含有更多的混凝工艺和两种类芬顿工艺均优先去除的大分子有机物（73%）,因此,1#渗滤液膜浓缩液具有更高的DOC去除率。此外,在两种类芬顿工艺处理过程中,大分子类物质逐渐转化为小分子类物质后,随着反应的进行,或许进一步矿化。对于含较多大分子有机物的渗滤液膜浓缩液,建议采用混凝或类芬顿工艺;而对于含较多小分子有机物的渗滤液膜浓缩液,建议采用混凝-类芬顿联合工艺处理。

Impact of dissolved organic matter composition on coagulation and Fenton-like processes for treating landfill leachate concentrate

This study was conducted to study the impact of dissolved organic matter (DOM) composition on the efficacy of coagulation, UV Fenton and Electro-Fenton for removing organics in of leachate concentrate from two sources. The DOM removal differences of two kinds of leachate membrane concentrates were compared and analyzed. The dissolved organic carbon (DOC) removal rate of coagulation, UV Fenton, and Electro-Fenton processes were 42%, 66% and 62%, respectively for the 1# leachate concentrate (processed by "MBR+NF"), and were 20%, 60% and 52% respectively for the 2# leachate concentrate (processed by "A/O+RO"). Experimental results showed the different DOC removals between two leachate concentrate samples treated by the same processes. These differences were attributed to different DOM composition between two leachate concentrate samples as indicated by the combined analysis of excitation-emission matrices (EEM) with parallel factor analysis (PARAFAC) and liquid chromatography-organic carbon detector (LC-OCD). Compared the 2# leachate concentrate (52% determined by LC-OCD analysis), the 1# leachate concentrate had a higher percentage of high molecular weight (HMW) organics (73% determined by LC-OCD analysis) which were preferentially removed by coagulation and two Fenton-like treatment, thus achieving higher DOC removal rate. Furthermore, it is speculated that macromolecular organics transformation into low molecular weight (LMW) organics and the subsequent mineralization of low molecular weight (LMW) organics may occur during two Fenton-like oxidations. On this basis, it is suggested that coagulation or Fenton-like process can be used if the leachate concentrate containing large portion of HMW organics, a combined coagulation-Fenton-like process was proposed for a better DOC removal in the leachate concentrate containing a large portion of LMW organics.