Degradation of Methylene Blue by Microwave Discharge Plasma in Liquid

Microwave plasma in liquid is a new plasma technology and becomes more and more concerned due to its large spatial distribution and high density of plasma. In this paper, methylene blue is degraded using plasma which is generated by 2450 MHz microwave in liquid. Effects of microwave power, initial concentration and pH on the degradation rate of methylene blue are studied respectively. Results show that the degradation rate of methylene blue increases with increasing of microwave power, and decreases with increasing pH in the range of 6‐8; When the initial concentration is less than 12.5 mg/L, the maximum degradation rate of methylene blue increases with increasing of its initial concentration, which can reach 96.56%. However, when the initial concentration is more than 12.5 mg/L, the maximum degradation rate appears decreased. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)