Department of Environmental Health, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
Department of Environmental Health, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
Carbohydr Polym. 2017 Apr 15;162:56-61. doi: 10.1016/j.carbpol.2017.01.046. Epub 2017 Jan 16.
In the present study, microbial cellulose (MC) as a carbohydrate polymer was made conductive by oxidative polymerization with aniline. Sulfate-reducing bacteria (SRB) were immobilized on the surface of the conductive biopolymer, and this was used as a biocathode in a bioreduction process to reduce Cr (VI) as a model of heavy metals. The results of Fourier transform infrared analysis confirmed that the polyaniline was distributed on the cellulose surface. The maximum tensile stress of the conductive biopolymer was obtained 23MPa using calculating Young's modulus. A current density of 60mA/m was determined as optimal, and an increase in pH from 5 to 7 significantly reduced the required time for reduction of Cr (VI). The system reached >99% removal of Cr (VI) within 1.5h at pH 7. Kinetic experiment studies showed a high constant rate (mean K 0.78, R 0.95). The results showed that the conductive MC can be used as an appropriate bioelectrode to reduce Cr (VI) in bioelectrochemical processes. It is expected that experimental results could be used as a reference for the utilization of MC in bioelectrochemical systems.
在本研究中，微生物纤维素（MC）作为一种碳水化合物聚合物，通过苯胺的氧化聚合作用使其具有导电性。将硫酸盐还原菌（SRB）固定在导电生物聚合物的表面，然后将其用作生物还原过程中的生物阴极，以还原 Cr（VI）作为重金属的模型。傅里叶变换红外分析的结果证实了聚苯胺分布在纤维素表面上。通过计算杨氏模量，获得了 23MPa 的导电生物聚合物的最大拉伸应力。确定 60mA/m 的电流密度为最佳值，并且 pH 值从 5 增加到 7 会显著降低还原 Cr（VI）所需的时间。在 pH 值为 7 时，该系统在 1.5 小时内即可达到 >99%的 Cr（VI）去除率。动力学实验研究表明，还原反应具有较高的恒定速率（平均 K 0.78，R 0.95）。结果表明，导电 MC 可作为一种合适的生物电极，用于在生物电化学过程中还原 Cr（VI）。预计实验结果可作为 MC 在生物电化学系统中应用的参考。
