Plastic waste recycling in arid regions: technology selection and sustainability trade-offs in Qatar

Plastic waste recycling has become an important pathway for reducing landfill dependence, conserving resources, and supporting circular economy transitions, particularly in arid regions where high material demand, harsh climatic conditions, and limited recycling infrastructure can constrain waste recovery. This review develops a technology-selection framework for plastic waste recycling in Qatar, with relevance to Gulf Cooperation Council (GCC) and other arid-region economies. The review synthesizes literature on plastic waste feedstocks, mechanical and chemical recycling routes, solvent-assisted recycling, pelletization, construction materials, additive manufacturing, life cycle assessment, techno-economic performance, digital enablers, and Qatar/GCC-specific implementation challenges. The analysis indicates that recycling pathways should not be evaluated solely on the basis of direct environmental burdens, but also in relation to feedstock quality, contamination level, recyclate performance, virgin-material substitution potential, processing cost, and end-use requirements. Mechanical recycling and pelletization are generally preferred for clean and separated polyethylene and polypropylene streams because of their lower processing complexity and higher commercial maturity. However, mixed, contaminated, or compatibility-limited plastic waste may require advanced sorting, compatibilization, solvent-assisted recycling, or selected chemical recycling routes to recover material value. Recycled plastics show potential in construction materials, fiber-reinforced systems, recycled filaments, oil sorbents, activated carbon composites, and other functional products; however, quality loss, microplastic generation, durability uncertainty, standardization gaps, and scale-up limitations continue to present important challenges. Digital technologies, including artificial intelligence, Internet of Things systems, and digital twins, can improve sorting accuracy, material traceability, process control, and lifecycle decision-making. Overall, the review emphasizes that circular plastic recycling in Qatar and similar arid regions requires feedstock-specific technology selection, life cycle and techno-economic assessment, localized recycling infrastructure, quality standards, and coordinated policy support.