OXIDATION OF NATURAL ORGANIC MATTER IN AQUEOUS SOLUTION BY PROCESSES INVOLVING OZONE AND/OR IONIZING RADIATION

摘要

The aim of the present work was to study the changes induced in some natural organic matter properties during ozonation and/or ionizing radiation processes. Ozonation and irradiation experiments first carried out with a ~(60)Co source indicated that all the oxidation processes tested (i.e. ozonation alone, O_3/H_2O_2 ; γ-irradiation and the combination γ-irradiation/O_3) lead to a decrease of the aromaticity (by measurement of the absorbance at 254 nm wavelenght) and of the molecular weight of the humic material. Simultaneously, this natural organic matter becomes more hydrophilic and more biodegradable. These changes are more pronounced when combined processes such as O_3/H_2O_2 and O_3/γ-irradiation are applied. As for electron beam irradiation it was also more effective in combination with ozone as far as 254 nm abatement is concerned. None of the oxidation processes applied was able to significantly change the DOC content but the BDOC increased in any case. Again the combined processes were more effective than ozonation alone.