A Biphasic Plasma Microreactor for Pollutants Degradation in Water

The combination of plasma technology with microfluidics has gained significant attention in recent years. The unique characteristics of microfluidic chips, such as high surface-to-volume ratio and efficient mass transfer, coupled with plasma’s ability to provide the necessary green energy for the degradation of complex molecules, make this combination promising for water and wastewater treatment applications. A gas/liquid biphasic dielectric barrier discharge (DBD) plasma microreactor powered by a nano-pulsed excitation source, at atmospheric pressure, was used to study the degradation of p-benzoquinone and caffeine in water, chosen as model molecules for water pollution. Based on High Performance Liquid Chromatography (HPLC) analyses, the argon plasma was able to completely degrade both molecules at concentrations 10 − 5 , 10 − 4 and 10 − 3 mol/L. At higher concentration (10 − 2 mol/L), the plasma promotes the synthesis of hydroquinone from p-benzoquinone. A 50% mineralization is achieved after plasma for the caffeine in aqueous solution at 10 − 5 M.