Photochemical degration of naproxen in the aquatic environment

Naproxen belongs to the group of non-steroidal anti-inflammatory drugs. It is often used to treat pain of rheumatic and non-rheumatic diseases. The photochemical experiments of naproxen degradation were performed in the wastewater effluents from wastewater treatment plant (WWTP) Kloten/ Switzerland at its real concentrations (without standard addition) and in drinking water containing naproxen standard, adjusted to pH = 7 and pH = 6. All performed experiments showed that within 5 min of photochemical oxidation, the disappearance of naproxen exceeded 90%. The first-order rate constants of naproxen degradation were determined. The maximal value of rate constant was observed by UV/H₂O₂ process in water samples at pH = 6 (k = 0.997 min^-1).