Cr(VI) removal performance from aqueous solution by Pseudomonas sp. strain DC-B3 isolated from mine soil: characterization of both Cr(VI) bioreduction and total Cr biosorption processes
Cr(VI) removal performance from aqueous solution by Pseudomonas sp. strain DC-B3 isolated from mine soil: characterization of both Cr(VI) bioreduction and total Cr biosorption processes
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假单胞菌从水溶液中去除 Cr(VI) 的性能。
DOI：
10.1007/s11356-019-06017-w
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发表时间：
2019-09-01
影响因子：
5.8
通讯作者：
Chen, Jinquan
中科院分区：
文献类型：
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作者：
Chang, Junjun;Deng, Shengjiong;Chen, Jinquan
微生物法是一种环境友好的重金属污染修复方法。从重金属污染的矿区土壤中分离到一株耐Cr（VI）的菌株DC-B3，经16 S rDNA基因测序鉴定为假单胞菌属（Pseudomonas sp.），并对其去除废水中Cr（VI）的性能进行了评价。该菌株表现出在低pH（2.0）下将Cr（VI）还原为毒性较小的Cr（III）而不添加外部电子供体的高能力。Cr（VI）初始浓度为135.0 mg L-1时，反应75 h后，Cr（VI）的还原量为32.0 mg. g-1。此外，41.0%的总铬从溶液中被去除的生物吸附，并在约5小时内达到平衡。吸附过程符合准二级动力学模型和Langmuir吸附等温式。解吸试验表明，NaOH是最有效的总铬解吸剂，和Cr（VI）和生成的Cr（III）都加载在DC-B3生物质。用扫描电镜-能谱仪和傅里叶变换红外光谱仪对铬处理后的菌体进行了表征。菌株DC-B3在矿区铬（VI）污染的修复中具有很高的应用潜力。
Microbial methods are promising and environmentally friendly methods for remediating heavy metal contamination. In this study, a Cr(VI)-resistant bacterial strain, DC-B3, which was identified as Pseudomonas sp. by 16S rDNA gene sequencing, was isolated from heavy metal-contaminated mine soil, and its performance in Cr(VI) removal from wastewater in terms of Cr(VI) reduction and total Cr adsorption was assessed. This strain exhibited a high capability to reduce Cr(VI) to less toxic Cr(III) without the addition of an external electron donor at low pH (2.0). The Cr(VI) reduction capacity and rate both increased linearly with increasing Cr(VI) concentration, with a reduction capacity of 32.0 mg Cr(VI)·g-1achieved at an initial concentration of 135.0 mg L-1over 75 h. In addition, 41.0% of the total Cr was removed from the solution by biosorption, and equilibrium was reached within approximately 5 h. The total Cr sorption process was well described by the pseudo-second-order kinetic and Langmuir isotherm models. Desorption assays indicated that NaOH was the most efficient agent for total Cr desorption, and Cr(VI) and generated Cr(III) were both loaded on the DC-B3 biomass. The bacterial cells after Cr treatment were characterized by scanning electron microscopy-energy dispersive X-ray spectrometer and Fourier transform infrared spectroscopy analyses. Strain DC-B3 showed high potential for possible application in the remediation of Cr(VI) contamination in mine areas.