Rosolic acid has been used as model Compound to check the efficiency of different advanced oxidation processes in the abatement of dyestuffs having triphenylmethane structure. Ozone is very effective; even at low flows (17 x 10(-3) min(-1) for an ozone flow of 0.2 g h(-1)) important degradation rates have been obtained. This effect is not enhanced by UV irradiation. On the other hand, different solar photocatalysts have been employed, namely Fe(III), Cr(III), Cr(VI) and TiO2. The best results are obtained using Fe(III), as under this experimental conditions, nearly complete elimination of the dye could be accomplished; however, TiO2 has also shown a good performance. The reaction has been scaled-up using a solar plant for water detoxification with rather promising results.