Use of UV photoreactors to remove diclofenac, bezafibrate and ethynylestradiol from sewage treated in UASB-TF system

ABSTRACT

This paper evaluated the removal of diclophenac (DCF), bezafibrate (BZF) and ethynylestradiol (EE2) from effluent of an anaerobic reactor coupled to a trickling filter (UASB-TF) in two types of UV photoreactors (immerse UV lamps - FRI and emmersed UV lamps - FRE). The results showed low removal efficiencies in both photoreactors when low contact times (10 min) and low initial concentration of such compounds was used (0.5 µg.L^-1 for EE2 and 21 µg.L^-1 for DCF and BZF). An increase in the initial concentration of DCF (to 20 mg.L^-1) and of the contact time (to 20 min) led to an increase in the removal efficiency (from 31 to 83% in FRI and from 36 to 86% in FRE), suggesting that dissolved compounds present in the biological effluent adversely affected the removal of the pharmaceutical tested due to competition for the incident UV radiation.

Keywords:
photoreactor. pharmaceuticals; post-treatment; sewage treatment.