Résumé:
The activated carbon (commercial or prepared by chemical activation way starting local lignocellulosic materials) can undergo changes under the influence of nitric acid oxidation with different concentrations. The modified and not modified activated carbon are characterized by different techniques of analysis (BET; MEB; elementary analysis; BOEHM method; mass titration; thermodésorption of CO and CO2). The specific area of the activated carbon prepared by chemical activation (CAP) is very interesting and about 820 m2 /g. Nevertheless, it has a mesoporous structure. Boehm titration showed that the oxidizing treatment accentuates the number of surface acidic sites. It was shown the coal oxidized with pure HNO3 has acidic site number highest than all about (247 me q/ 100 g). All the samples (treated and not treated carbons), giving the optimum results, were tested in adsorption of organic polluants: toluene and xylene. However, the out put in maximum adsorption of xylene and toluene is of approximately 95%, 65% respectively for the activated carbon prepared (CAP), and 90%, 76% respectively for the carbon commercial (CAB).
