Photodegradation of Pharmaceuticals in Partially Nitritated Wastewater
Certain pharmaceutically active compounds may not be readily removed in anaerobic wastewater treatment, and the effluents from anaerobic wastewater treatment processes often contain high levels of ammonia. A polishing step is therefore necessary to remove nitrogen and trace organic contaminants. For nitrogen removal, an increasingly popular technology is the anammox process, in which the first step involves partial conversion of ammonia to nitrite. Given that nitrite is an efficient sensitizer for production of hydroxyl radical, a UV irradiation step after partial nitrification might also be used to remove pharmaceuticals. The direct and indirect photolysis of pharmaceutical compounds is being investigated in systems containing nitrite, ammonia, and organic matter. A 450 W medium-pressure mercury vapor lamp is used with a wavelength cutoff filter for wavelengths below 220 nm. Results indicate that the presence of nitrite enhances the removal of pharmaceutical compounds in the simulated effluent matrix.
Dr. William Arnold, Dr. Paige Novak, and Priya Hora