High efficiency and rapid treatment of naproxen sodium wastewater by dielectric barrier discharge coupled with catalysis

Abstract

Pharmaceutical wastewater has the characteristics of high organic concentration and poor biodegradability, which will cause serious environmental pollution when discharged into water bodies. In this work, naproxen sodium was used to simulate pharmaceutical wastewater by dielectric barrier discharge technology. The effects of dielectric barrier discharge (DBD) and combined catalysis on the removal of naproxen sodium solution were studied. The removal effect of naproxen sodium was affected by discharge conditions, including discharge voltage, frequency, air flow rate and electrode materials. It was found that the highest removal rate of naproxen sodium solution was 98.5%, when the discharge voltage was 7000V, the frequency was 3333Hz, and the air flow rate was 0.3 m3/h. In addition, the effect of the initial conditions of naproxen sodium solution was studied. The removal of naproxen sodium was relatively effective at low initial concentrations as well as under the condition of weak acid or near-neutral solution. However, the initial conductivity of naproxen sodium solution had little effect on the removal rate. The removal effect of naproxen sodium solution was compared by using catalyst combined with DBD plasma and DBD plasma alone. x%La/Al2O3, Mn/Al2O3 and Co/Al2O3 catalysts were added. The removal rate of naproxen sodium solution reached the highest after adding 14%La/Al2O3 catalyst, which played the best synergistic effect. The removal rate of naproxen sodium was 18.4% higher than that without catalyst. The results showed that the combination of DBD and La/Al2O3 catalyst may be a promising method to remove naproxen sodium efficiently and quickly. And this method is a new attempt to treat naproxen sodium.