An integrated chemical and ecotoxicological assessment for the photocatalytic degradation of vancomycin.
The photocatalytic degradation of an antibiotic, vancomycin B hydrochloride (VAN-B), has been investigated in aqueous suspensions of titanium dioxide (TiO2) by monitoring the change in its concentration as well as the production of ammonia and chlorides as a function of irradiation time. The removal of 50mg L(-1) VAN-B solution yields maximum concentrations of 2.45 and 2.53 mg N-NH3 L(-1) after 120 min of photocatalytic oxidation using 0.1 and 0.2 g TiO2 L(-1), respectively. When 0.2 g TiO2 L(-1) were applied up to 87% of the stoichiometric amount of chloride was reached within 120 min of irradiation, corresponding to 0.087 mmol L(-1). A set ofbioassays (Daphnia magna, Pseudokirchneriella subcapitata and Ceriodaphnia dubia) was performed to evaluate the potential detoxification of VAN-B and its by-products of oxidation under chronic and acute tests. The toxicity of the treated VAN-B samples varied during the oxidation, due to the formation of some intermediate products more toxic than VAN-B. Despite almost total removal of VAN-B that was achieved within 120 min of irradiation, a significant increase in toxicity was observed in chronic tests proving that the chronic assays are more appropriate than acute ones to detect the impact of by-products formed during the photocatalytic degradation of antibiotics.
Giusy
G
Lofrano
Maurizio
M
Carotenuto
Ceyda Senem
CS
Uyguner-Demirel
Alessia
A
Vitagliano
Antonietta
A
Siciliano
Marco
M
Guida
D000818:Animals; D003621:Daphnia; D010782:Photolysis; D023382:Toxicity Tests, Acute; D036401:Toxicity Tests, Chronic; D014466:Ultraviolet Rays; D014640:Vancomycin / Q000528:radiation effects* / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000528:radiation effects* / Q000633:toxicity
D014874:Water Pollutants, Chemical; D014640:Vancomycin