| 초록 |
Two novel visible-light (λ > 420 nm) photolysis systems as a post-treatment process of soil flushing or washing were devised. In the presence of either TiO2 photocatalyst or Fe3+ ions, CCl4 could be successfully dechlorinated in nonionic surfactant (Brij 35) solution under visible-light illumination. In TiO2 system, surfactant acted as a sensitizer, and it delivers electrons to CCl4 via TiO2 conduction band (CB) to achieve the reductive dechlorination of CCl4. When the suspension was saturated with O2, the initial dechlorination rate was lowered. In Fe3+ system, the addition of the Fe3+ ions much enhanced the dechlorination rates. Fe3+ forms complexes with surfactants, where these complexes can act as more efficient visible-light sensitizers. In both systems, the initial CCl4 degradation rates increased when surfactant concentration and CCl4 concentration increased. The present system can provide a basis of developing solar remediation for contaminated soil and groundwater using surfactants. |
