Ozone tertiary treatment for pharmaceuticals and personal care products removal from municipal wastewater

An ozone pilot plant was installed at a conventional WWTP to evaluate the removal rate of emerging contaminants, drugs, and fragrances, as tertiary treatment. The filtered secondary effluent flow rate ranged between 1.3÷1.9 m3/h with a retention time of 10÷30 minutes and the plant operated with an ozone dose of 2- 4 mgO3/l. The results evidenced a high removal rate of 80-100% for most of the organic targeted compounds: Amisulpride, Azithromycin, Carbamazepine, Diclofenac, Clarithromycin and Ofloxacin. Lower removal rates from 20% to 80%, were observed for some substances e.g. Gabapentin Lactam, Galaxolidone, Irbesartan, Lamotrigine, and Tonalide. Advanced Oxidation Process (AOP) treatment with O3/H2O2, (0.5–1.0–2 molH2O2/molO3) allowed improved results for almost all these latter. In addition, ozone determined up to 42% removal of the absorbance at 254 nm and 20% of COD, wastewater disinfection, a decrease of the GC-MS chromatographic area, and no acute toxicity effect nor estrogenic and mutagen effects have been detected.