Radiolysis and ozonolysis of a landfill leachate

A landfill leachate sample was radiolyzed with ??-rays at 12.5, 25, 50, 100, 200 and 400?kGy. The radiolyzed solutions were studied by UV?CVIS?CNIR spectroscopy to measure the color change, by chemical oxygen demand (COD) analysis to check the degree of mineralization of the soluble organic matter present in the leachate and by FT?CIR spectroscopy of the humic substance of the leachate. The results have shown that the humic substance present in the landfill leachate is extremely refractory to radiolysis: even at 400?kGy it was detected and recovered only with minor changes. It is shown that the radiolysis followed by ozonolysis is able to cause important improvements of the leachate color and important reduction on the COD. However, the results in terms of bleaching and COD abatement after radiolysis and ozonolysis of the leachate can be achieved directly by a simple exhaustive ozonolysis of the leachate. The structural changes occurring in the humic substances and in the humic acids present in the leachate after radiolysis and ozonolysis were analyzed by FT?CIR spectroscopy.