The study was undertaken to compare from technical and economic point of view the treatment of antibiotic aqueous solution containing amoxicillin, ampicillin, and cloxacillin by Fenton, photo-Fenton, TiO2 photocatalytic and UV/ZnO processes. The best operating conditions for treatment of antibiotic aqueous solution containing 104, 105 and 103 mg/L of amoxicillin, ampicillin, and cloxacillin, respectively were: Fenton process COD/H2O2/Fe2+ molar ratio 1:3:030 and pH 3; photo-Fenton process COD/H2O2/Fe2+ molar ratio 1:1.5:0.075 and pH 3; UV/TiO2/H2O2 process - TiO2 1 g/L, ambient pH similar to 5 and H2O2 100 g/L; UV/ZnO process - ZnO 0.5 g/L and pH 11. All studied processes were able to degrade the antibiotics and improve biodegradability (BOD5/COD ratio), except for UV/ZnO process which did not improve biodegradability. Photo-Fenton process exhibited higher rate constant (0.029 min(-1)) than that of Fenton process (0.0144 min(-1)) and this may be ascribed to photochemical regeneration of Fe2+ ions by photoreduction of Fe3+ ions and hence increasing hydroxyl radical production rate. Rate constants of UV/ZnO process (0.00056 min(-1)) and UV/TiO2/H2O2 process (0.0005 min(-1)) were lower than that of Fenton and photo-Fenton processes. Photo-Fenton process appeared to be the most cost-effective compared to the other studied processes. (C) 2010 Elsevier B.V. All rights reserved.