Overcoming Osmotic Shock in Semiconductor Sludge Bioconversion via Dielectric Buffering and Spatiotemporal Decoupling

The bioconversion of semiconductor processing sludge (SPS) is conventionally bottlenecked by highly cross-linked extracellular polymeric substances (EPSs) that sequester concentrated inorganic salts. Forcible EPS deconstruction in single-stage anaerobic digestion triggers an abrupt release of these ions, inducing acute osmotic shock and systemic metabolic failure. To overcome this coupled thermodynamic and kinetic barrier, this study proposes a spatiotemporal decoupling framework utilizing waste resource sludge (WRS) as a physicochemical buffering matrix with a proposed ion-hydration/dielectric contribution. An engineered two-stage system was evaluated using controlled laboratory-scale anaerobic batch assays at 41 °C to segregate the initial acidogenic deconstruction from the subsequent methanogenic mineralization. Baseline single-stage digestion suffered severe paralysis, characterized by an electrical conductivity (EC) surge to 46.9 mS/cm and a negligible methane yield (14.5 mL CH4/g VS). Conversely, the decoupled strategy effectively buffered the peak ionic stress to a safe threshold (15.8 mS/cm) and enhanced macromolecular liquefaction, achieving a 3.4-fold increase in soluble chemical oxygen demand. Consequently, the methanogenic stage delivered a maximum methane potential of 294.6 mL CH4/g VS with a significantly shortened lag phase of 3.2 days. Molecular and taxonomic analyses confirmed that this enhanced performance was driven by structural EPS dismantling and a targeted microbial succession—transitioning from a robust Lactobacillaceae-dominated consortium for initial deconstruction to a diverse bacterial syntrophic network associated with methanogenic conversion. These findings establish the mechanistic feasibility of the proposed approach under controlled laboratory-scale batch conditions. Continuous-flow validation is nevertheless required to determine long-term process stability and engineering-scale applicability. Ultimately, this microenvironmental buffering approach provides a resilient, mild intervention pathway for extreme industrial waste, providing a potential mechanistic framework for future cross-industry resource circularity.