Degradation of acetic acid in water using gas-liquid plasma with SPG membrane

The gas-liquid mixed phase plasma generated by a nanoseconds-pulsed discharge in bubbles was used for degradation of acetic acid in water. A Shirasu porous glass (SPG) membrane tube was adopted as micro-bubble generator and part of a discharge reactor. A large number of tiny bubbles are generated from dense micro-pores (average diameter of φ50 μm) of the SPG wall and a discharge through SPG membrane was initiated between high voltage electrode and bubble surface. Comparing with a resin tube reactor which has six mechanical holes (diameter of φ1 mm), the surface area of bubbles increased with the same gas flow rate. The hydrogen peroxide (H₂O₂) concentration in treated water using SPG membrane reactor increased by about 71% compared with that using the resin tube reactor, and the degradation amount of acetic acid was also promoted by about 82% when Ar gas was used with the flow rate of 2 L/min. Meanwhile the H₂O₂ production and degradation of acetic acid proportionally increased with the growth of gas flow rate in the SPG membrane reactor.