A landfill leachate sample was radiolyzed with γ-rays at 12.5, 25, 50, 100, 200 and 400 kGy. The radiolyzed solutions were
studied by UV–VIS–NIR 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–IR 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–IR spectroscopy.
Authors:Giancarlo Angelini, Ornella Ursini, and Franco Cataldo
Fullerene/silica hybrid materials were obtained by radiation grafting on silica surface of toluene or decalin solutions of
C60. As determined by thermogravimetric analysis, the amount of C60 grafted on silica surface was dependent from the radiation dose administered and independent from the C60 concentration and the nature of the organic solvent. In absence of air, a dose of 48 kGy was sufficient to ensure a grafting
level of 30% by weight of C60 in the hybrid material. The fullerene/silica hybrid material shows a remarkable thermal stability, since the early decomposition
starts above 300 °C as measured by DTG and DTA. The chemical structure of the fullerene/silica hybrid material was determined
by FT-IR spectroscopy and with solid state 13C CP-MAS NMR. The potential application of such materials has been outlined.