Degradation of sulfonated polyethylene by a bio-photo-fenton approach using glucose oxidase immobilized on titanium dioxide

Polyethylene (PE) plastics are highly recalcitrant and resistant to photo-oxidative degradation due to its chemically inert backbone structure. We applied two novel reactions such as, Bio-Fenton reaction using glucose oxidase (GOx) enzyme alone and Bio-Photo-Fenton reaction using GOx immobilized on TiO2 nanoparticles (TiO2-GOx) under UV radiation, for (bio)degradation of pre-activated PE with sulfonation (SPE). From both the reactions, GC-MS analyses identified small organic acids such as, acetic acid and butanoic acid as a major metabolites released from SPE. In the presence of UV radiation, 21 fold and 17 fold higher amounts of acetic acid (4.78 mM) and butanoic acid (0.17 mM) were released from SPE after 6 h of reaction using TiO2-GOx than free GOx, which released 0.22 mM and 0.01 mM of acetic acid and butanoic acid, respectively. Our results suggest that (bio)degradation and valorization of naturally weathered and oxidized PE using combined reactions of biochemistry, photochemistry and Fenton chemistry could be possible. [Display omitted] •Polyethylene was activated using chemical sulfonation and iron (III) grafting method.•Glucose oxidase (GOx) was immobilized on titanium dioxide nanoparticles (TiO2-GOx).•Bio-Fenton degradation of sulfonated polyethylene (SPE) was studied using GOx and TiO2-GOx.•UV radiation and TiO2-GOx accelerated speed of Bio-Fenton degradation of SPE.•Small organic acids were released from SPE using Bio-Fenton and Bio-Photo-Fenton reactions.