MnO₂/Al₂O₃催化剂-微气泡臭氧体系催化降解喹啉及其机理

A doped catalyst MnO₂/Al₂O₃ was prepared by using Al₂O₃ as the support. The catalyst exhibit the highest activity when the calcination temperature and duration was 500 ℃ and 4 h, respectively, and the mass percent of MnO₂ was 8%. The nano-sized MnO₂ was distributed on the surface of the Al₂O₃ support according to the scanning electron scope (SEM) analysis. The specific surface area (BET), average pore volume and pore diameter of the catalyst reached 183.22 m²•g^-1, 0.27 cm³•g^-1 and 4.87 nm, respectively. A catalyst ozonation system was established with MnO₂/Al₂O₃ and microbubble ozone. The removal rate of quinoline reached >95% at the ozone dose of 30 mg•L^-1 and the reaction time of 60 min. The TOC removal rate for the secondary effluent of the real coal chemical wastewater achieved 55% after 20 min reaction at the ozone dose of 180 mg•L^-1•h^-1. In addition, it is proved that •OH dominated the removal of quinoline in the catalytic ozonation reaction with MnO₂/Al₂O₃ catalyst by using tertiary butanol (TBA) as molecular probe.