This book explores sustainable waste management innovations. In resource recovery technologies, it highlights catalytic conversion of solid wastes like biomass and plastics into valuable chemicals, wastewater extraction methods such as acid-leaching for pollutant removal, and reclamation of hazardous residues including fly ash for environmental applications. It addresses toxicity identification and remediation, covering assessments of disinfection by-products and PAHs in soils, pollution source tracking using sensor-GC-MS coupling, and advanced solutions like AI-optimized leachate treatment to mitigate microplastic release. Finally, it applies ecological principles to eco-engineering approaches?such as diatomite-enhanced anaerobic digestion and integrated energy-fertilizer systems?while evaluating urban risks like microplastic-heavy metal interactions in rivers, airborne metal impacts on vegetation, and antibiotic resistance genes in soils for holistic ecosystem restoration.