Abstract
Recalcitrant pharmaceuticals and personal care products (PPCPs) like flurbiprofen often elude conventional wastewater treatments, posing significant environmental risks that necessitate innovative solutions. Advanced oxidation processes based on sulfate radicals (˙SO(4) (-)) from activated peroxymonosulfate (PMS) can facilitate the thorough degradation of PPCPs in wastewater thanks to their superior oxidation potential. This study developed a nitrogen-doped multilayer graphene catalyst, INC(II), from cotton fibers via template-assisted pyrolysis. Sodium chloride was used as the hard template, facilitating easy template removal and avoiding usage of hazardous hydrofluoric acid. A nitrogen-containing ionic liquid [EMIm][N(CN)(2)] was employed as the nitrogen source. With 0.5 g L(-1) of the INC(II) catalyst and 6 mM of PMS, the flurbiprofen removal rate reached approximately 94.9% (initial concentration = 20 mg L(-1)), surpassing all previously reported work. Pyridinic nitrogen proved the most potent active site for PMS activation. By incorporating waste cotton fibers into the pharmaceutical wastewater treatment solution, this study offers a practical approach to biomass recycling and an actionable reference for treating waste with waste.