Sorption and Photocatalytic Degradation of Trichlorfon by Foam Concrete Blended with Nitrogen-Doped Titanium Dioxide

摘要

Foam concrete incorporated with nitrogen-doped TiO_2 (N-TiO_2/FC) was fabricated, characterized, and tested for the sorption and degradation of trichlorfon. The removal performance of trichlorfon under visible-light irradiation by using this concrete was compared with that using pure foam concrete (FC) and foam concrete incorporated with TiO_2 (TiO_2/FC). Factors including the amount of photocatalysts and curing age were investigated. The N-TiO_2/FC exhibited a higher removal efficiency of trichlorfon but a lower sorption than FC and TiO_2/FC. The sorption and photocatalytic activity decreased with curing age and the amount of incorporated nanoparticles. Seventy-five percent of 20 mg/L trichlorfon was absorbed by N-TiO_2/FC (6% incorporation and 1-day curing) in 540 min, and 19% of the sorbed trichlorfon was degraded in 180 min with a compressive strength of 4.9 MPa. The FC could absorb nearly 83% of trichlorfon in 540 min but degrade less than 1% in 180 min. Moreover, 6% N-TiO_2/FC exhibited the best performance (removed almost 100% of trichlorfon in 2 weeks) in pilot-scale experiments, indicating its potential use in nonpoint pollution control.