Energy consumption of three different advanced oxidation methods for water treatment: a cost-effectiveness study

The present work provides an economic comparative study of three TiO2-based advanced oxidation technologies for removing two well known contaminants from water. The relative costs and outcomes of catalytic ozonation (TiO2/O3 in dark), photocatalytic oxidation (TiO2/UVA/O2), and photocatalytic ozonation (TiO2/UVA/O3) were compared with regard to the degradation of oxalic acid and dichloroacetic acid as model compounds. The combination of TiO2, UVA, and O3 showed the highest cost-effectiveness among the assessed methods. In the case of oxalic acid decomposition, the cost-effectiveness of catalytic ozonation and photocatalytic oxidation was about two and nine times less than that of photocatalytic ozonation. For the degradation of dichloroacetic acid, catalytic ozonation and photocatalytic oxidation were two and 15 times more expensive than photocatalytic ozonation systems with regard to their output. These results were explained well by the synergistic effects on the generation of hydroxyl radicals using photocatalytic ozonation systems.