Paracetamol Degradation Performance and Mechanisms Using Microwave-Assisted Heat-Activated Persulfate in Solutions

A microwave (MW) heat-activated the persulfate (PS) process was employed to treat paracetamol (PAM) in wastewater, and the powder-activated carbon (PAC) be used is used as a catalyst to accelerate this reaction process. The PAM added (100 mg) to the solution was nearly completely removed within 70 min, and the PH, temperature, PAC, and PS dosage have great influence on the degradation process; the total organic carbon (TOC) removal rate reached 98%. The PAC¹ still had a good catalytic effect after being reused six times. The radical mechanism was investigated to determine the type of dominant active species involved in PAM degradation. Sulfate radicals (SO4−•) were the dominant oxidizing agent for PAM degradation under acidic conditions. The degradation mechanism was proposed based on the PAM degradation intermediates, which were identified using ultra-high-performance liquid chromatography coupled with linear trap quadrupole orbitrap mass spectrometry. Three types of possible reaction pathways for PAM were identified as follows: including hydroxylation of the benzene ring, amine group oxidation at the benzene ring, and amine (HN–C=O) functional group N–C bond cleavage.