Heterogeneous photocatalytic degradation of phenol and derivatives by (BiPO4/H2O2/UV and TiO2/H2O2/UV) and the evaluation of plant seed toxicity tests

We examined the photocatalytic degradation of phenol from laboratory samples under UV radiation by using BiPO 4 /H 2 O 2 and TiO 2 /H 2 O 2 advanced oxidation systems. Both catalysts prepared were characterized by scanning electron microscopy, Fourier transform infrared and X-ray diffraction. Surface area tests showed about 3.46 and 31.33m 2 ·g −1 , respectively, for BiPO 4 and TiO 2 . A central composite design was developed with the following variables--catalyst concentration, time and concentration of hydrogen peroxide--to optimize the degradation process. Removal rates of 99.99% for phenol degradation using BiPO 4 and TiO 2 were obtained, respectively. For mineralization of organic carbon were obtained 95,56% when using BiPO 4 and 63,40% for TiO 2 , respectively. The lumped kinetic model represented satisfactorily the degradation of phenol process, using BiPO 4 /H 2 O 2 /UV ( R 2 =0.9977) and TiO 2 /H 2 O 2 /UV ( R 2 =0.9701) treatments. The toxicity tests using different seed species showed the benefits of the proposed advanced oxidation process when applied to waste waters containing these pollutants.