Imtiaz Afzal Khan

Advanced oxidation processes (AOPs), driven mainly by hydroxyl ( ^• OH) and sulfate (SO ₄ ^•− ) radicals, can mineralize micropollutants or transform recalcitrant pollutants into biodegradable intermediates. However, heterogeneous AOPs often suffer from rapid quenching of reactive species and limited catalyst recyclability. This study critically assesses recent progress in membrane‐based nanoconfined AOPs with a main objective of critically evaluating polymeric catalytic membranes vs. ceramic catalytic membranes. According to our literature survey, we identify ultrafast kinetics by polymeric catalytic membranes, particularly layered double hydroxide incorporated polymeric membranes with a k value of up to 240 000 min ⁻¹ ; and angstrom‐confined laminar membranes achieving millisecond‐scale degradation, albeit with substantial flux‐activity trade‐offs. On the other hand, ceramic catalytic membranes are observed to maintain lower median flux (55 LMH) and lower median k values (0.88 min ⁻¹ ). Importantly, they show predictable hydraulics, broader oxidant compatibility, robustness under harsh pH, and effective removal of mixed micropollutants via radical and non‐radical pathways. Significant evidence was found for the restructuring of water under nanoconfinement, along with enrichment of reaction media, strengthening of oxidant adsorption, lowering activation barriers, and suppressing radical self‐quenching. Future implementation will require integrated advances in membrane engineering, catalyst design, reactor/process integration, and scalable manufacturing of catalytic membranes.

Industrial wastes in the form of chromium, generated by leather industries, commonly contaminate soil, affecting its geotechnical properties. The present study examines the impact of trivalent chromium Cr(III) on the soil’s mechanical, physiochemical, and microstructural properties. The soil and Cr(III) were collected from an industrial area in Sheikhupura, Pakistan, and are mixed in various proportions ranging from 0% to 50% by weight to simulate various contamination levels. A detailed experimental program that included index and strength testing, in addition to physiochemical analysis, was carried out. Modifications in microstructure and mineralogical composition were also examined using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). The results showed an increase in the soil strength characteristics, with maximum dry density (MDD) and cohesion enhanced up to 15% and 12%, respectively, with an addition of Cr(III) up to 20% contamination concentration. Notable reduction in the soil pH was also observed, indicating the acidic impact of Cr(III). Microstructural examination affirmed significant mineralogical rearrangement, with quartz remaining the dominant mineral. The results provided useful insights into the geotechnical implications of Cr(III) contamination in clayey soils and will contribute to improved assessment of the soil behavior in industrially contaminated zones.