Effect of dielectric barrier discharge plasma on persulfate activation for rapid degradation of atrazine: Optimization, mechanism and energy consumption.

Dielectric barrier discharge plasma (DBDP) is an emerging and promising advanced oxidation process (AOP) for wastewater treatment. After investigating the effect of input voltage, O (generated by dielectric barrier discharge), and peroxydisulfate (PDS) dosage, the DBDP/PDS system was established. With the assistance of PDS, the atrazine (ATZ) removal efficiency increased from 69.67% to 82.46% within 25 min. Synergistic effect calculation suggests that there were markedly synergies between DBDP, O and PDS. Under the effect of SO, the total organic carbon (TOC) removal and dechlorination efficiency were significantly improved. In addition, the DBDP/PDS system maintained the ATZ removal efficiency at a high level over a wide range of initial pH values. According to quenching experiments and electron paramagnetic resonance (EPR) detection, the dominant radical for ATZ degradation in the DBDP/PDS system was HO. A possible degradation pathway of ATZ was proposed based on density functional theory (DFT) analysis, quadrupole-time of flight-liquid chromatography/mass spectrometry (Q-TOF-LC/MS) results, and related literature. The acute toxicity to aquatic minnows and the developmental toxicity of intermediate products prediction confirmed that the DBDP/PDS system could effectively reduce ATZ toxicity. The electrical energy per order (E) was 7.10 kWh m order illustrating that the DBDP/PDS was a more energy-economic system than other energy-intensive processing technologies.