Use of Desulfovibrio and Escherichia coli Pd-nanocatalysts in reduction of Cr(VI) and hydrogenolytic dehalogenation of polychlorinated biphenyls and used transformer oil
Use of Desulfovibrio and Escherichia coli Pd-nanocatalysts in reduction of Cr(VI) and hydrogenolytic dehalogenation of polychlorinated biphenyls and used transformer oil
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DOI：
10.1002/jctb.3763
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发表时间：
2012-10-01
影响因子：
3.4
通讯作者：
Wood, Joe
中科院分区：
文献类型：
--
作者：
Macaskie, Lynne E.;Humphries, Andrea C.;Wood, Joe
背景：脱硫弧菌属。生物制造金属纳米颗粒（例如 Bio-Pd），可催化 Cr(VI) 还原为 Cr(III) 并脱卤多氯联苯 (PCB)。脱硫弧菌属厌氧并产生 H2S，这是一种有效的催化剂毒物，而大肠杆菌可以在有氧条件下预生长至高密度，具有明确的分子工具，并且还可以产生具有催化活性的生物钯。第一个目的是比较由脱硫弧菌属 (Desulfovibrio spp) 制造的生物钯催化剂。和大肠杆菌使用悬浮和固定催化剂。第二个目的是评估用过的变压器油中生物钯介导的多氯联苯脱卤的潜力，这阻碍了回收和再利用。结果：在 Pd:生物质质量负载量为 1:3 的情况下，通过还原水溶液（固定化催化剂）中的 Cr(VI) 以及从 PCB 和废变压器油（催化剂悬浮液）中氢解释放 Cl-，对 Bio-PdD.desulfuricans 和 Bio-PdE.coli 的催化作用进行了比较。在这两种情况下，Bio-PdD.desulfuricans 的性能均优于 Bio-PdE.coli 约 3.5 倍，这归因于通过磁性测量（Bio-PdD.desulfuricans）和化学吸附分析（Bio-PdE.coli）确定的 Pd 纳米颗粒表面积约 3.5 倍的差异。通过电子显微镜，在脱硫杆菌上发现了小钯颗粒，在大肠杆菌上发现了更少、更大的钯颗粒。从用过的变压器油中生物-PdD.脱硫剂介导的氯离子释放（5.6 +/- 0.8 mu g mL-1）与使用几种 PCB 参考材料观察到的结果相当。结论：在 Pd:生物质负载量为 1:3 时，Bio-PdD.desulfuricans 的活性比 Bio-PdE.coli 高 3.5 倍，这归因于前者较小的纳米颗粒尺寸所反映的相对催化剂表面积。这项研究还显示了 Bio-PdD.desulfuricans 修复废变压器油的潜力。版权所有(c)2012 中国化学工业学会
BACKGROUND: Desulfovibrio spp. biofabricate metallic nanoparticles (e.g. Bio-Pd) which catalyse the reduction of Cr(VI) to Cr(III) and dehalogenate polychlorinated biphenyls (PCBs). Desulfovibrio spp. are anaerobic and produce H2S, a potent catalyst poison, whereas Escherichia coli can be pre-grown aerobically to high density, has well defined molecular tools, and also makes catalytically-active Bio-Pd. The first aim was to compare Bio-Pd catalysts made by Desulfovibrio spp. and E. coli using suspended and immobilized catalysts. The second aim was to evaluate the potential for Bio-Pd-mediated dehalogenation of PCBs in used transformer oils, which preclude recovery and re-use. RESULTS: Catalysis via Bio-PdD.desulfuricans and Bio-PdE.coli was compared at a mass loading of Pd:biomass of 1:3 via reduction of Cr(VI) in aqueous solution (immobilized catalyst) and hydrogenolytic release of Cl- from PCBs and used transformer oil (catalyst suspensions). In both cases Bio-PdD.desulfuricans outperformed Bio-PdE.coli by similar to 3.5-fold, attributable to a similar to 3.5-fold difference in their Pd-nanoparticle surface areas determined by magnetic measurements (Bio-PdD.desulfuricans) and by chemisorption analysis (Bio-PdE.coli). Small Pd particles were confirmed on D. desulfuricans and fewer, larger ones on E. coli via electron microscopy. Bio-PdD.desulfuricans-mediated chloride release from used transformer oil (5.6 +/- 0.8 mu g mL-1) was comparable with that observed using several PCB reference materials. CONCLUSIONS: At a loading of 1:3 Pd:biomass Bio-PdD.desulfuricans is 3.5-fold more active than Bio-PdE.coli, attributable to the relative catalyst surface areas reflected in the smaller nanoparticle sizes of the former. This study also shows the potential of Bio-PdD.desulfuricans to remediate used transformer oil. Copyright (c) 2012 Society of Chemical Industry