The present study has consisted to the disinfection of water by photosensitization with 5-methoxypsoralen fixed on polystyrene (MOP-5-P). The results obtained in this study show the complete inhibition of fecal coliforms after six minutes of irradiation (365 nm). But the system (MOP-5-P) loses its activity after the application because of the formation of 5-MOP photodimers on the surface of polystyrene (2, 2-cycloaddition). Irradiation at a wavelength below 320 nm allows the regeneration activity of MOP-5-P system. This shows that these photodimers formed on the surface of polystyrene are reversible and depend on wavelength irradiation. This reversibility is demonstrated by the regeneration activity of the system after irradiation at 254 nm.
The study of water disinfection by photosensitization with methoxy-5 psoralen showed complete inhibition of fecal coliforms after 60 minutes of exposure to the light at all concentrations used (0.006; 0.2 and 0.340 g / l). The kinetic study shows that the kinetic constants are classified in the following order: 0.11; 0.15 and 0.17 min-1, respectively for 0.006; 0.2 and 0.340 g / l. In the other hand, for the faecal enterococci, complete inhibition was observed after 5 minutes of exposure at all concentrations used (0.006; 0.2 and 0.340 g / l).