Degradation of polyethylene microplastics using high-repetition-rate pulsed dielectric barrier discharge plasma in air under mild conditions

초록

The degradation of microplastics (MPs) using dielectric barrier discharge (DBD) plasma hasattracted considerable research attention. However, most existing studies have employedsinusoidal AC high-voltage systems, which have inherent limitations. This study presents aneffective method for degrading polyethylene (PE) MPs using a high-repetition-rate pulsed DBDthat generates uniform, intense discharges in air. Under conditions of 15 kV and 20 kHz, 0.1 gof PE MPs was completely degraded within 3 h without the use of catalysts or additional carriergases. Experimental and numerical analyses of the discharge characteristics revealed thatplasma-generated energetic electrons facilitated PE degradation while producing variousreactive oxygen and nitrogen species. The degradation process initiated at the particle surface,leading to the formation of oxygen- and nitrogen-containing functional groups. Structural,chemical, and surface degradation mechanisms were proposed, and the degradation tendencyaccording to influence of voltage and frequency is presented on degradation was evaluatedbased on the experimental results. This study advances MP degradation research by enhancingthe efficiency of DBD plasma technology and providing deeper insights into the underlyingmechanisms.

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