光催化氧化降解垃圾渗滤液中溶解性有机物

Degradation of dissolved organic matter in landfill leachate during photocatalytic treatment process

研究了UV-TiO2光催化氧化降解垃圾渗滤液过程中溶解性有机物(DOM)的变化特征。结果表明:在适宜条件下,UV-TiO2光催化氧化降解垃圾渗滤液的色度、COD和DOC的去除率分别可达97%、72%和60%;紫外光谱分析说明渗滤液DOM中包括多种含有共轭双键、羰基的大分子有机物及多环芳香类化合物,不同光催化处理液中DOM具有基本一致的结构单元和官能团;红外光谱分析说明渗滤液DOM中含有大量包括羟基、羧基、氨基和苯环的芳香族化合物,在光催化处理液中这几种官能团都能被有效降解;GC/MS分析结果表明,渗滤液DOM中含有72种有机污染物,醇类、羧酸和酮类分别为25、14和12种;在光催化72 h处理液中,有机物减少为44种;酯类和醇类较多,分别为12种和16种;酮类8种,羧酸没有检出。

The characteristic of dissolved organic matter （DOM） from landfill leachate was studied during UV-TiO2 photocatalytic degradation. The results showed that the removal rates of color, DOC and COD were up to 97% , 72% and 60% , respectively under optimum photocatalytic conditions. The outcomes of the UV spec- trum indicated that the DOM of raw leachate contained a variety of macromolecular organic matters and polynu- clear aromatic compounds with conjugated double bonds and earbonyl. After the photoeatalytic treatment, the DOM of the effluents through different treatment periods had similar chemical structural units and functional groups. The results of FTIR spectrum suggested that the DOM of raw leachate contained large number of aromatic compounds with hydroxyl, carboxyl, amino groups and benzene rings, which were degraded effectively by photo- catalysis. GC/MS results presented that the DOM of raw leaehate had 72 sorts of organic compounds, including 25, 14 and 12 kinds of alcohols, carboxylic acids and ketones, respectively; while 44 sorts of organic compounds were detected in the effluents after 72 h treatment, including 12 kinds of esters, 16 kinds of alcohols, 8 kinds of ketones and none of carboxylic acids.