College of Environmental Sciences and Engineering, Peking University, Beijing 100871, People's Republic of China.
Appl Microbiol Biotechnol. 2012 Jul;95(1):263-72. doi: 10.1007/s00253-011-3692-6. Epub 2011 Nov 19.
The removal of 2,4-dinitrotoluene (2,4-DNT) by simultaneous UV-photo(cata)lysis and biodegradation was explored using intimately coupled photolysis/photocatalysis and biodegradation (ICPB) with two novel porous carriers. First, a porous ceramic carrier was used to attach the photocatalyst (TiO₂) on its exterior and accumulate biomass in its interior. UV irradiation alone decomposed 71% of the 2,4-DNT in 60 h, and TiO₂ catalyst improved the photolysis to 77%. Second, a macroporous sponge carrier was used to strongly adsorb 2,4-DNT and protect microorganisms from 2,4-DNT inhibition and UV irradiation. The main photolytic reactions were reduction of the nitryl to amino and hydrolysis of the amino to release NH₄⁺. The main biodegradation reactions were oxidative release of NO₃⁻ and accelerated reductive release of NH₄⁺. ICPB more thoroughly released inorganic N, with nearly equal amounts being oxidized to nitrate and reduced to ammonium. The genera Burkholderia and Bacillus were found inside the sponge carriers, and they are associated with biodegradation of DNT and its photolysis intermediates. Therefore, using an adsorbent and macroporous biofilm carrier enabled the effective removal of 2,4-DNT by ICPB.
采用两种新型多孔载体，通过紧密耦合的光解/光催化和生物降解（ICPB）探索了 2,4-二硝基甲苯（2,4-DNT）的去除。首先，使用多孔陶瓷载体将光催化剂（TiO₂）附着在其外部，并在其内部积累生物量。单独的紫外线照射在 60 小时内分解了 71%的 2,4-DNT，而 TiO₂催化剂将光解提高到了 77%。其次，使用大孔海绵载体强烈吸附 2,4-DNT，并保护微生物免受 2,4-DNT 抑制和紫外线照射。主要的光解反应是将硝酰基还原为氨基，以及将氨基水解为释放 NH₄⁺。主要的生物降解反应是氧化释放 NO₃⁻和加速还原释放 NH₄⁺。ICPB 更彻底地释放无机 N，其中几乎等量的 N 被氧化为硝酸盐和还原为铵盐。在海绵载体内部发现了伯克霍尔德菌属和芽孢杆菌属，它们与 DNT 及其光解中间体的生物降解有关。因此，使用吸附剂和大孔生物膜载体可以通过 ICPB 有效去除 2,4-DNT。
