Plasmacatalytic removal of lead acetate assisted by precipitation

Abstract

The Gliding Arc Discharge (GAD) is an efficient non-thermal plasma technique able to degrade organiccompounds dispersed in water at atmospheric pressure. The degradation of the organometallic leadacetate (PbAc) in aqueous solution was performed by two distinct plasmageneous processes: GAD andGAD/TiO2.The global oxidation of the organic matter was followed by Chemical Oxygen Demand (COD)and the mineralization was determined by the Total Organic Carbon (TOC). The Pb2+ionsreleased during the degradation process were measured by Atomic Absorption Spectroscopy(AAS).For 2 h of GAD treatment, the degradation rate of PbAc (10 mM) reached 83% and for the same durationof GAD/TiO2process ([TiO2]=1gL 1), it reached 93%.The release of Pb2+ions in the solution was respectively of 95% and 57% for GAD and GAD/TiO2processes. The released Pb2+ions were removed by precipitation process in a basic medium at pH = 11.1.A reaction mechanism was proposed to explain the PbAc molecule degradation and the Pb2+elimination.