Degradation of dissolved organic matter in landfill leachate during photocatalytic treatment process
光催化氧化降解垃圾渗滤液中溶解性有机物

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 spectrum indicated that the DOM of raw leachate contained a variety of macromolecular organic matters and polynuclear aromatic compounds with conjugated double bonds and carbonyl. After the photocatalytic 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 photocatalysis. GC/MS results presented that the DOM of raw leachate 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.