Abstract: The drilling and blasting method is currently the primary method for tunnel and roadway excavation; however, the blasting process generates substantial amounts of carbon monoxide (CO), posing a significant threat to the safety and health of construction personnel. To achieve efficient purification of CO from tunnel/roadwway blasting operations, based on CO photocatalytic oxidation technology, this study experimentally investigated the effects of catalyst type, light source parameters, gas flow rate, and reaction temperature on the photocatalytic purification efficiency of CO. Based on these findings, a photocatalytic purification device for blasting-derived CO in tunnel/roadway was developed and empirically validated through field trials. This research reveals that: (1) Among the three catalysts tested—ZnO, Pt/TiO₂, and CuO/Al₂O₃—the metal-supported catalyst CuO/Al₂O₃ exhibits the highest photocatalytic activity for the CO reaction, achieving a CO removal efficiency of 99.41% at an initial concentration of 8 000×10^-6. (2) The three optimal operational parameters for the light source are: wavelength within the visible spectrum (≥420 nm), power of 266 W, and an illumination distance of 10 cm. Under these conditions, CO with an initial concentration of 8 000×10^-6 can be reduced to below 100×10^-6 within 9 minutes, corresponding to a removal efficiency of 99.45%. (3) A linear increase in CO photocatalytic purification efficiency was observed with decreasing gas flow rate and increasing reaction temperature. Furthermore, the catalyst’s performance remained unaffected by high temperatures within the tested range of up to 100 ℃. (4) Based on these experimental results, a photocatalytic purification device for tunnel/roadway blasting-derived CO was developed. Field validation confirmed substantial purification efficacy, with average removal rates of 58.55% for peak post-blasting CO concentrations and 62.82% for minimum concentrations.

Key words: tunnel blasting, drilling and blasting method, CO mitigation, photocatalysis, field test