Environment

The rapid increase in the production and consumption of electronic and electrical equipment has resulted in a significant global increase in electronic waste (e-waste). This complex waste stream has valuable rare earth elements, precious metals, and base metals, positioning it as an important secondary resource for the recovery of critical metals. With proper extraction and recovery technologies, e-waste presents a…

Platinum group metals (PGMs) are key components of automotive emission-control catalysts, and spent automotive catalysts (SACs) are their main secondary source. This paper reviews hydrometallurgical, pyrometallurgical, magnetic-separation, biometallurgical, and ionic-liquid/deep-eutectic-solvent (IL/DES) routes and compares them for recovery, selectivity, energy demand, reagent hazard, technology readiness, and scalability, using values re-checked against accessible primary sources. Smelting with Cu- or Fe-based collectors is…

Effective management and safe disposal of hazardous industrial waste remain critical challenges for sustainable construction. Aluminum-anodizing and nickel-electroplating sludges (AAS and NES) pose several environmental risks. This study focuses on developing multifunctional, ternary-blended alkali-activated materials from ground-granulated blast-furnace slag (GGBFS), AAS and NES, combining adequate mechanical performance, heavy-metal immobilization (Ni) and gamma-ray shielding. The composites were designed by replacing 10-30…