State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
Environ Sci Technol. 2011 Dec 1;45(23):10186-93. doi: 10.1021/es202356w. Epub 2011 Oct 28.
Nitrobenzene (NB) is a toxic compound that is often found as a pollutant in the environment. The present removal strategies suffer from high cost or slow conversion rate. Here, we investigated the conversion of NB to aniline (AN), a less toxic endproduct that can easily be mineralized, using a fed-batch bioelectrochemical system with microbially catalyzed cathode. When a voltage of 0.5 V was applied in the presence of glucose, 88.2 ± 0.60% of the supplied NB (0.5 mM) was transformed to AN within 24 h, which was 10.25 and 2.90 times higher than an abiotic cathode and open circuit controlled experiment, respectively. AN was the only product detected during bioelectrochemical reduction of NB (maximum efficiency 98.70 ± 0.87%), whereas in abiotic conditions nitrosobenzene was observed as intermediate of NB reduction to AN (decreased efficiency to 73.75 ± 3.2%). When glucose was replaced by NaHCO(3), the rate of NB degradation decreased about 10%, selective transformation of NB to AN was still achieved (98.93 ± 0.77%). Upon autoclaving the cathode electrode, nitrosobenzene was formed as an intermediate, leading to a decreased AN formation efficiency of 71.6%. Cyclic voltammetry highlighted higher peak currents as well as decreased overpotentials for NB reduction at the biocathode. 16S rRNA based analysis of the biofilm on the cathode indicated that the cathode was dominated by an Enterococcus species closely related to Enterococcus aquimarinus.
硝基苯（NB）是一种有毒化合物，通常作为环境污染物存在。目前的去除策略存在成本高或转化速率慢的问题。在这里，我们研究了使用微生物催化阴极的分批生物电化学系统将 NB 转化为苯胺（AN）的方法，AN 是一种毒性较低的终产物，易于矿化。当施加 0.5 V 电压并存在葡萄糖时，在 24 小时内，88.2±0.60%的供应 NB（0.5 mM）转化为 AN，分别比非生物阴极和开路控制实验高 10.25 和 2.90 倍。在 NB 的生物电化学还原过程中仅检测到 AN 是唯一产物（最大效率 98.70±0.87%），而在非生物条件下观察到亚硝基苯是 NB 还原为 AN 的中间产物（效率降低至 73.75±3.2%）。当葡萄糖被 NaHCO3 取代时，NB 的降解速率降低了约 10%，但仍实现了 NB 选择性转化为 AN（98.93±0.77%）。当对阴极电极进行高压灭菌时，形成亚硝基苯作为中间产物，导致 AN 形成效率降低至 71.6%。循环伏安法突出显示了在生物阴极上 NB 还原的峰值电流更高，过电位降低。基于 16S rRNA 的阴极生物膜分析表明，阴极主要由与 Aquimarinus 肠球菌密切相关的肠球菌种主导。
