Characterization of Glass-Cutting Sludge and Process Wastewater Toward Resource Recovery and Sustainable Water Management

This study presents a comprehensive and integrated characterization of solid and liquid residues generated during industrial glass-cutting operations, highlighting the novelty of treating glass-cutting sludge and process wastewater as compositionally linked outputs of the same industrial comminution process. The research examined the morphology, elemental composition, and selected physicochemical properties of sludge and wastewater-derived particulates to assess material-recovery potential and provide a basis for further evaluation of water reuse. Samples were analyzed using particle morphology assessment, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS), Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR), dynamic light scattering (DLS), and pH measurements. The results showed that the solid fraction consisted predominantly of soda–lime–silica glass constituents, with oxygen, silicon, sodium, calcium, and magnesium as the main components, while potentially problematic contaminants remained at low levels. Although isolated particles enriched in Fe, Cu, Ni, Sn, La, or Ce were detected, their occurrence was limited and did not significantly affect the average particulate composition observed within the SEM-EDS dataset. This is particularly important for coated glass, where functional coatings contribute negligibly to the bulk glass matrix. From a material-recovery perspective, the sludge should be regarded as a promising glass-derived mineral residue requiring further route-specific qualification rather than as waste intended solely for disposal. However, this study does not demonstrate suitability for any specific reuse route, and additional validation is needed regarding compositional consistency, variability, moisture and organic content, leaching behavior, and route-specific acceptance criteria. For process wastewater, contamination was governed mainly by suspended glass-derived solids, indicating that solid–liquid separation is the key treatment step. However, the present dataset is insufficient to confirm the suitability of treated water for direct industrial recirculation, and the results should therefore be interpreted as indicating potential for further evaluation after appropriate clarification. This work establishes an empirical multi-scale characterization framework that links glass-cutting sludge and process wastewater as compositionally related outputs of the same comminution process, thereby supporting circular-economy strategies by jointly informing sludge valorization and water-clarification pathways. Overall, this work establishes a multiscale characterization framework for integrated residue management, jointly supporting sludge valorization and wastewater clarification assessment within a circular-economy perspective.