Optimizing Plasma Bubbles at Pilot Scale for Organic Pollutant Degradation in Water

This study investigates the scalability of nanopulsed plasma bubble technology for water remediation, transitioning from lab to pilot scale. The pilot-scale plasma bubble reactor was optimized to degrade toxic organic pollutants, including dyes (methylene blue, MB), antibiotics (sulfamethoxazole, SMX), and pharmaceuticals (valsartan, VAL). High degradation efficiencies were achieved: >99% for MB after 10 min, >99% for SMX after 20 min, and >98% for VAL after 40 min. The reactor produced high concentrations of short-lived hydroxyl radicals (·OH, ~25 mg/L under O2), with minimal long-lived species (O3, H2O2, NO3-/NO2-), maintaining stable pH (~7). Energy efficiency was superior at the pilot scale, with electrical energy per order (EEO) values of 0.18 kWh/m3 for MB, 0.42 kWh/m3 for SMX, and 0.88 kWh/m3 for VAL, 2-3 orders of magnitude lower than other advanced oxidation processes (AOPs). The system’s performance was consistent across tap and ultrapure water, demonstrating its applicability in real-world conditions. These findings highlight the potential of nanopulsed plasma bubbles for rapid, effective, and energy-efficient water remediation at larger scales.