Zhou Qing, Chen Xing-Juan, Guo Jun, Sun Guo-Ping, Xu Mei-Ying
Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
Huan Jing Ke Xue. 2013 Jul;34(7):2855-61.
Characteristics and optimal reaction conditions of anaerobic azoreduction by the Shewanella decolorationis S12 in the presence of zero-valent iron (ZVI) were evaluated in this study. The results showed that the presence of ZVI significantly enhanced the decolorization rate of azo dye. In the presence of 20 mmol x L(-1) ZVI, the decolorization rate of 1 mmol x L(-1) amaranth reached up to 100% by the Shewanella decolorationis S12 after 30 h incubation, which was significantly higher than 23.16% and 94.66% in the pure strain S12 and pure ZVI treatment systems, respectively. When 20 mmol x L(-1) of sodium formate was added in the medium, ZVI still improved the decolorization rate of amaranth by 20.54%. In addition, the presence of ZVI significantly increased the azo dye treatment amount in the ZVI plus S12 system. In the system with ZVI, 1 mmol x L(-1) amaranth was completely reduced 11 times in fed-batch process within 276 h, while the dye could only be completely reduced 3 times in the system without ZVI. The optimal pH and the Fe(0) dose for the ZVI plus S12 system was 9.0 and 60 mmol c L(-1), respectively. The microscale ZVI was more suitable for the decolorization than those with larger size and the nanoscale ZVI. This study may provide some useful information for improving the biodegradation of azo dye in the treatment system with ZVI.
本研究评估了零价铁（ZVI）存在下希瓦氏菌S12厌氧偶氮还原的特性及最佳反应条件。结果表明，ZVI的存在显著提高了偶氮染料的脱色率。在20 mmol·L⁻¹ ZVI存在下，经30 h培养后，希瓦氏菌S12对1 mmol·L⁻¹苋菜红的脱色率高达100%，分别显著高于纯菌株S12处理体系中的23.16%和纯ZVI处理体系中的94.66%。当在培养基中添加20 mmol·L⁻¹甲酸钠时，ZVI仍使苋菜红的脱色率提高了20.54%。此外，ZVI的存在显著增加了ZVI加S12体系中偶氮染料的处理量。在含ZVI的体系中，1 mmol·L⁻¹苋菜红在分批补料过程中276 h内完全还原了11次，而在无ZVI的体系中该染料仅能完全还原3次。ZVI加S12体系的最佳pH值和Fe(0)剂量分别为9.0和60 mmol·c·L⁻¹。微米级ZVI比尺寸更大的ZVI和纳米级ZVI更适合脱色。本研究可为改善含ZVI处理体系中偶氮染料的生物降解提供一些有用信息。
