Assessing the targeted breakdown of pharmaceutical compounds via the generation of chlorine dioxide gas in situ

Abstract

This work evaluates the degradation of pharmaceutical compounds (PhCs) in complex effluents by in-situ generated chlorine dioxide (ClO2) gas. Data collected from the University Hospital Complex of Albacete (CHUA, Spain) were used as a case study to simulate a real polymedicated hospital urine. Initially, the in-situ production of ClO2 via the reduction of chlorate (ClO3-) using hydrogen peroxide (H2O2) is carried out, paying attention to the role of the air flowrate used to drag ClO2 to the treatment chamber. Then, the efficiency of the ClO2 (g) treatment is evaluated. Results show that the complete removal of metamizole-MAA (MTZ-MAA), piperacillin (PIP) and meropenem (MRP) is possible within 240 min of ClO2 treatment (using ∼5.0 mg dm−3 ClO2), but the degradation rate depends on the target compound. The ClO2 has shown a high selectivity to MTZ-MAA against PIP and MRP, which seems to be more reactive towards ClO2. The Total organic carbon (TOC) is reduced less than 10%, but ClO2 treatment is able to reduce the chemical risk of hospital urine, due to the conversion of PhCs into simpler molecules (identified by LC-MS), that do not exhibit an antibiotic effect.