Hydrogen peroxide generation during regeneration of granular activated carbon by bipolar pulse dielectric barrier discharge plasma

Abstract

Hydrogen peroxide (H2O2) is one of the pivotal reactive species produced in dielectric barrier discharge (DBD) plasma. We studied the characteristics of H2O2 generation during DBD regenerating granular activated carbon (GAC) process driven by a bipolar pulse power. A range of measurements were conducted to explore the effects of different conditions like pulse voltage, air support rate, and GAC water content on H2O2 formation on the GAC. The rate constant and energy efficiency of H2O2 generation were also calculated to investigate kinetics. The results indicated that the greater discharge intensity and air supply rate were beneficial to H2O2 production, and there was a moderate value of GAC water content (20%) for its formation. The highest H2O2 amount was 297.8µmol/kg GAC under the parameters of pulse voltage of 28kV, air flow rate of 1.2L/min and GAC water content of 20%. Meanwhile, the efficiencies of phenol removal on GAC and GAC regeneration were promoted with the treatment time, which reached 93.3% and 88.5% after 100min, respectively. The main degradation byproducts such as catechol, hydroquinone, and benzoquinone formed on GAC were increased firstly and then decreased with the treated duration.