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 BiPO4/H2O2 and TiO2/H2O2 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 31.33m2·g−1, respectively, for BiPO4 and TiO2. 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 BiPO4 and TiO2 were obtained, respectively. For mineralization of organic carbon were obtained 95,56% when using BiPO4 and 63,40% for TiO2, respectively. The lumped kinetic model represented satisfactorily the degradation of phenol process, using BiPO4/H2O2/UV (R 2=0.9977) and TiO2/H2O2/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.