Application of concrete surfaces as novel substrate for immobilization of TiO2 nano powder in photocatalytic treatment of phenolic water.

BACKGROUND: In this study, concrete application as a substrate for TiO2 nano powder immobilization in heterogeneous photocatalytic process was evaluated. TiO2 immobilization on the pervious concrete surface was done by different procedures containing slurry method (SM), cement mixed method (CMM) and different concrete sealer formulations. Irradiation of TiO2 was prepared by UV-A and UV-C lamps. Phenolic wastewater was selected as a pollutant and efficiency of the process was determined in various operation conditions including influent phenol concentration, pH, TiO2 concentration, immobilization method and UV lamp intensity. FINDINGS: The removal efficiency of photocatalytic process in 4 h irradiation time and phenol concentration ranges of 25-500 mg/L was more than 80 %. Intermediates were identified by GC/Mass and spectrophotometric analysis. CONCLUSIONS: According to the results, photocatalytic reactions followed the pseudo-first-order kinetics and can effectively treate phenol under optimal conditions.