Non-thermal gliding arc plasma for cesium-137 mobilization and radiological risk reduction in electric arc furnace dust

Electric arc furnace dust (EAFD) contains hazardous metals and radionuclides such as 137Cs+ immobilized within Fe- and Zn-based oxide matrices, posing environmental and radiological risks. This study investigates non-thermal gliding arc (GA) air plasma for enhancing 137Cs+ removal from aqueous EAFD suspensions. Plasma parameters were optimized based on their effects on water chemistry and reactive oxygen and nitrogen species formation. Under optimal conditions (200 W, 40 LPM, and 30 s), significant acidification and accumulation of nitrate and nitrite were observed, leading to matrix destabilization. The activity concentration decreased from 106.7 to 39.3 Bq g-1 (∼63.2% removal), while the dose rate was reduced by ∼78.3%. The results confirm effective radionuclide mobilization and demonstrate the potential of GA plasma for rapid EAFD remediation.