初始pH值变化及臭氧氧化对垃圾渗滤液中有机物组成的影响

Effect of Initial pH Change and Ozone Oxidation on Organic Composition in Landfill Leachate

为识别臭氧氧化技术的分步处理过程中渗滤液的有机物浓度及组成类型的变化,寻求提高臭氧氧化技术去除垃圾渗滤液中有机物的方法。通过对两种有机物组成不同的垃圾渗滤液进行初始pH值调节及臭氧氧化实验,解析渗滤液中不同特性的有机物被去除的主要原因和步骤。结果表明,在初始pH值调节至11时,SAARB尾水和NF浓缩液中的UV254、色度(Colour Number, CN)、总有机碳(Total Organic Carbon, TOC)的去除率最大,分别达到16.97%、27.37%、9.31%和24.07%、36.00%、23.72%;进一步臭氧氧化,pH调节为11的实验组中SAARB尾水和NF浓缩液的UV254、CN、TOC的去除率分别达到65.34%、90.92%、30.02%和42.52%、75.06%、11.27%。紫外-可见光谱和三维荧光光谱的结果表明,调节渗滤液初始pH值时,渗滤液中有机物通过絮凝沉淀去除,有机物的芳香性和疏水性降低;而臭氧氧化过程可破坏有机物不饱和键,进而降低渗滤液中有机污染物的分子缩合度和分子量,并提高有机物的可生化性,臭氧氧化过程对类富里酸占比更高的渗滤液有更好的氧化效果。实验结果为臭氧氧化技术处理不同有机物组成的垃圾渗滤液的技术优化提供新思路。

In order to identify the changes of the concentration and composition of organic compounds in the leachate during the stepwise ozonation process,and to improve the efficiency of the ozonisation process to remove organic compounds from landfill leachates.Through the experiments of initial pH adjustment and ozone oxidation on two kinds of landfill leachates with different organic composition,the main reasons and steps of removing organic matter with different characteristics in leachate were analyzed.The results showed that when the initial pH value was adjusted to 11,the removal rates of UV_(254),CN and TOC in SAARB tail water and NF concentrate reached 16.97%,27.37%and 9.31%,and 24.07%,36.00%and 23.72%,respectively.After further ozonation,the removal rates of UV254,CN and TOC of SAARB tail water and NF concentrate reached 65.34%,90.92%and 30.02%,and 42.52%,75.06%and 11.27%in the experimental group with pH 11.The results of Ultraviolet-visible spectroscopy and three dimensional fluorescence spectrum showed that when the initial pH value of the leachate was adjusted,the organic matter in leachate was removed by flocculation precipitation,and the aromatic property and hydrophobicity of organic compounds were reduced.While ozonation process can destroy unsaturated bonds of organic compound,and then reduce the molecular condensation degree and molecular weight of organic pollutants in the leachate.Moreover,the biodegradability of organic compounds was improved.The ozonation process has a belter oxidation effect on the leachate with a higher proportion of fulvic acid.The experimental results provide a new idea for the optimization of ozonation technology in the treatment of landfill leachate with different organic composition.