NOx sequestration by calcium aluminate cementitious materials

This study quantifies NOx uptake efficiency and explores binding mechanisms in calcium aluminate cementitious (CAC) materials. Comparison between unmodified TiO2-modified CAC separates intrinsic from those related to photocatalysis. Attributed surface-related heterogeneous reactions, the occurs at nitrite-to-nitrate ratio of 1: 1.3 can be increased with surface area. The photocatalytic reactions increase uptake, ~50% converted resists releasing back into environment via dissolution. Compared previously studied ordinary portland cement (OPC) materials, increases capacity demonstrates a more permanent binding, potentially mitigating concerns release bound N-species OPC. Examination interaction synthetic pure aluminum-bearing phase shows that could largely attributed chemical within phases.