Degradation of acetaminophen in water by using dielectric barrier discharge

Acetaminophen is the most commonly used drug worldwide for relieving pain and fever. Consequently, it has been detected in groundwater in different areas of the world. In this study, acetaminophen removal from water using a dielectric barrier discharge (DBD) system, operated in the open air, was investigated. Our results show that treating water for only 0.5 min at 1, 5, 25, 50, 75 and 100 mg L-1 acetaminophen concentration resulted in the removal of 98.85%, 99%, 89.16%, 42.84%, 33.86% and 32.87% of the initial acetaminophen amount, respectively. These removal rates increased significantly when the treatment duration was extended to 2 min, reaching 100%, 99.40%, 99.66%, 90.62%, 85.89% and 77.09% of the initial amount of acetaminophen at similar concentrations, respectively. The initial pH of the solution causes a negligible variation in the degradation of the acetaminophen; therefore, it was not found as an important parameter. The pH of the solution decreases during the plasma treatment. The final pH of different solution was always within 15%, regardless of the initial concentration. Optical emission spectroscopy of the DBD during operation revealed the prominent reactive species and possible reaction pathways. The acetaminophen removal efficiency of the DBD system used in this study for water treatment is higher than that reported for other systems employed in previous studies. Moreover, as the discharge is generated here in the open air, it is very cost-effective. Further studies are recommended to investigate DBD operated in open air for the removal of other organic pollutants from water.