Title: Oxidation of clofibric acid in aqueous solution using a non-thermal plasma discharge or gamma radiation,
Abstract: In this work, we study degradation of clofibric acid (CFA) in aqueous
solution using either ionizing radiation from a $^{60}$Co source or a
non-thermal plasma produced by discharges in the air above the solution. The
results obtained with the two technologies are compared in terms of
effectiveness of CFA degradation and its by-products. In both cases the CFA
degradation follows a quasi-exponential decay in time well modelled by a
kinetic scheme which considers the competition between CFA and all reaction
intermediates for the reactive species generated in solution as well as the
amount of the end product formed. A new degradation law is deduced to explain
the results. Although the end-product CO$_2$ was detected and the CFA
conversion found to be very high under the studied conditions, HPLC analysis
reveals several degradation intermediates still bearing the aromatic ring with
the chlorine substituent. The extent of mineralization is rather limited. The
energy yield is found to be higher in the gamma radiation experiments.