Cuttlefish Bone-Supported CoFe2O4 nanoparticles enhance persulfate Fenton-like process for the degradation of polystyrene nanoplastics

Abstract

The study aimed to address the environmental challenge posed by polystyrene nanoplastics (PS-NPs), which are widespread and resistant to conventional degradation methods. In response, an innovative approach integrating magnetically catalytic persulfate activation and a Fenton-like strategy was developed for the efficient degradation of PS-NPs in aquatic environments. To achieve this, cuttlefish bone (CFB)-supported CoFe2O4 nanoparticles were synthesized and characterized comprehensively using structural, textural and microscopic analyses. The maximum catalytic/adsorption efficiency (99.3 %, with a rate constant of 0.151 min−1) was achieved under optimal conditions, specifically at 0.8 g/L CoFe2O4/CFB, 0.75 g/L ammonium persulfate (APS), and an initial pH of 7, within a 30-min contact time. Additionally, the feasibility of this approach was tested in real water matrices from tap and river sources. The plausible mechanism involved the synergistic action of hydroxyl radical (HO•) and sulfate radical (SO4•−) through a Fenton-like reaction pathway. The adsorption kinetics and isotherm results revealed that the pseudo-second-order (R2 0.990) and Langmuir (R2 0.998) models described the adsorption of PS-NPs on CoFe2O4/CFB more effectively. These nanoparticles effectively facilitate the continuous circulation of Co2+/Co3+ and Fe2+/Fe3+ redox cycles on the surface of CoFe2O4, thereby enhancing the activation of SO4•− and HO• radicals. Notably, CoFe2O4/CFB effectively addresses particle aggregation issues and minimizes metal ion leaching (<0.01 % of Fe, <1.35 % of Co). Furthermore, CoFe2O4/CFB exhibited stability over five cycles, maintaining efficient PS-NP removal performance (98.40–83.35 %). The findings will furnish technical insights into the aging and degradation of microplastics, thereby presenting novel avenues for combating microplastic pollution. Additionally, it proposes a sustainable means for microplastics to integrate into the ecosystem's carbon cycle, thereby reducing their environmental impact.