Journal of Environmental Chemical Engineering, cilt.14, sa.3, 2026 (SCI-Expanded, Scopus)
The significant accumulation of microplastics (MPs) in wastewater sludge poses a potential risk to the efficiency and stability of anaerobic digestion (AD). While sludge disintegration methods are commonly used to enhance AD efficiency, their effects on the properties and leaching behavior of MPs are not well documented. This study evaluated the effects of different disintegration methods on polyethylene terephthalate (PET), polypropylene (PP), and polycarbonate (PC) microplastics (MPs), with particular emphasis on additive leaching potential and associated physical and chemical property changes of MPs. Sludge samples spiked with MPs (10 mg/g total solids) were subjected to alkali (0.5 M, 2 days), thermal (127°C, 2 h), enzymatic (pancreatin, 200 mg/g TS, 38°C, 24 h), and combined alkali–thermal (ATD) and thermal–enzyme disintegration (TED) treatments. The release of common additives from these plastics, such as phthalates and bisphenol A (BPA), was analyzed by GC-MS and recovered MPs were characterized by ATR-FTIR, and SEM. Phthalates showed little or no leaching after disintegration; in contrast, bisphenol A (BPA) concentrations increased by up to 4,000-fold in polycarbonate (PC)–containing sludge after ATD. Combined treatments reduced the carbonyl index of PET and PC. The most pronounced surface modification was observed in PC microplastics exposed to ATD. These findings demonstrate that additive release is strongly dependent on the disintegration method, raising concerns about secondary pollution and warranting further investigation.