fig6

Figure 6. FTIR Spectra of PS MPs. (A) Pristine PS - Typical peaks of intact PS: aliphatic C–H (2,850-2,950 cm^-1), aromatic C–H (~3,025 cm^-1), aromatic C=C (1,600, 1,450 cm^-1), and C–H bending (756, 698 cm^-1); (B) Control PS - Retains characteristic PS peaks with minor weak C=O stretching (~1,700 cm^-1) and broad O–H band (~3,300-3,400 cm^-1), indicating limited abiotic oxidation during incubation; (C) Degraded PS by Bacillus cereus - Reduced C–H peaks (3,025, 2,915 cm^-1), new –OH band (3,300-3,400 cm^-1), carbonyl peak (~1,700 cm^-1), and weakened aromatic peaks, confirming oxidative degradation and polymer chain cleavage. FTIR: Fourier transform infrared; PS: polystyrene; MPs: microplastics.