TiO₂-Enhanced Recycled Concrete: A Systematic Review for Sustainable Air Pollution Reduction in Industrial Zones (Case Study: Asaluyeh, Iran)

This study systematically reviews the application of TiO₂ nanoparticles in recycled concrete to enhance sustainability and reduce air pollution in industrial zones. Based on the analysis of 72 studies (2015–2024), incorporating 1.5–2% TiO₂ improves compressive strength by 12–18% and achieves NOx reduction of 27–35%. A case study in Asaluyeh, Iran, demonstrates that applying TiO₂-enhanced concrete to just 10% of structures could mitigate approximately 800 tons of air pollutants annually. Challenges such as increased production costs and standardization gaps are discussed, alongside strategies for practical implementation. This work supports the advancement of sustainable construction practices aligned with UN Sustainable Development Goals.