微生物燃料电池产电性能及处理含铜重金属废水的研究

发布时间：2018-03-26 06:21

  本文选题：微生物燃料电池　切入点：产电性能　出处：《江苏理工学院》2015年硕士论文

【摘要】：随着现代重工业的发展,电镀、金属冶炼、石油工业、农药生产等行业均会产生大量含铜废水,若不经处理直接排放到环境中会产生巨大的危害。电化学法操作方便、不产生二次污染、高效快速,可直接回收金属铜,但电解法能耗高,处理高浓度废液时尚可产生较为可观的经济效益,但是电流效率随着浓度的降低而降低,这限制了电解法在低浓度废水处理中的推广应用。微生物燃料电池(Microbial fuel cell,MFC)是利用微生物的新陈代谢作用将化学能转化为电能的装置,用MFC产生的电流可以代替电解法处理含铜废水技术中的传统电源,解决了电解法处理含铜废水能耗过高的问题。实验构建双室MFC反应器,以模拟有机废水为阳极基质,以厌氧活性污泥为阳极菌种,以硫酸铜废水为阴极液,考察电极、膜、负载和温度等运行参数对MFC产电性能的影响。结果表明:活性炭/石墨棒为电极材料的MFC产电性能最高,功率密度最大6.9 m W·m-2。电极距离为2 cm时MFC功率密度最大48.4 m W·m-2,MFC的产电性能随电极表面积的增大而增大。使用美国杜邦质子交换膜的MFC产电性能最高,MFC产电性能随膜的面积的增加而增大。MFC的外阻不断增大,MFC的输出电压随之提高,输出电流则不断减小。25℃时MFC产电性能最强,MFC的最大功率密度为4.8 m W·m-2。实验考察了MFC阳极有机废水处理及其产电性能,分别以1000 mg·L-1的蔗糖溶液、1000 mg·L-1的乙酸钠溶液、1000 mg·L-1的六次甲基四胺溶液为阳极燃料,结果表明:乙酸钠为阳极燃料时MFC产电性能最高,MFC产电性能随阳极液浓度的增加而提高。添加磷酸盐缓冲溶液大大提高MFC的产电能力,最大电流密度达到4.44 m A·m-2。MFC对阳极室废水COD的去除率达到60~80%左右。使用显微镜、透射电镜观察阳极生物膜,发现阳极液中存在着菌胶团、原生动物、微型后生动物等。实验考察了MFC对模拟含铜废水的处理效果,构建了双室MFC,分别以5000 mg·L-1的Cu SO4溶液、5000 mg·L-1的Cu Cl液、5000 mg·L-1的 Cu(NO3)液为阴极液,结果表明:Cu SO4溶液为阴极液时MFC产电性能最高,MFC产电性能随阴极液浓度的增加而提高。阴极室中Cu2+去除率可达80%~92%。阴极板上红褐色沉积物经XRD检测,主要为单质铜和Cu2O的混合物,Cu2+含量可达74%~85%左右。实验构建了5种构型的MFC装置——SMFC、H型MFC、矩形MFC、U型MFC、双室无膜折流板式MFC,SMFC的产电性能最好,H型MFC的产电性能最低。5种构型的MFC均可有效处理含铜废水,但SMFC无法回收铜,利用扫描电镜观察沉积物表面形貌主要为花状和树枝状,铜粉的平均粒径为1000 nm~2000 nm左右。实验分别构建间歇流MFC与连续流MFC,连续流MFC产电性能略优于间歇流MFC。实验以铜渣浸出液为阴极液成功启动MFC装置,最大功率密度为1.33 m W·m-2,阴极液中Cu2+的去除率达到88.5%。
[Abstract]:With the development of modern heavy industry, electroplating, metal smelting, petroleum industry, pesticide production and other industries will produce a large amount of copper wastewater, if discharged directly into the environment without treatment, it will cause great harm. No secondary pollution, high efficiency, high speed, direct recovery of metal copper, but high energy consumption of electrolytic process, the treatment of high concentration waste liquid can produce considerable economic benefits, but the current efficiency decreases with the decrease of concentration. This limits the use of electrolysis in the treatment of low-concentration wastewater. Microbial fuel cells are devices that use microbial metabolism to convert chemical energy into electrical energy. The current generated by MFC can replace the traditional power supply in the treatment of copper containing wastewater by electrolysis, which solves the problem of excessive energy consumption in the treatment of copper containing wastewater by electrolysis. A two-chamber MFC reactor is constructed, and the simulated organic wastewater is used as the anode matrix. The effects of operating parameters such as electrode, membrane, load and temperature on the electrical properties of MFC were investigated by using anaerobic activated sludge as anodic bacteria and copper sulfate wastewater as cathode solution. The results showed that MFC with activated carbon / graphite rod as electrode material had the highest electrical performance. When the electrode distance is 2 cm, the maximum power density of MFC is 48.4 m W m ~ (-2). The electrical properties of MFC with Dupont proton exchange membrane increase with the increase of electrode surface area. With the increase of the area of the membrane, the output voltage of the MFC increases with the increase of the external resistance of the MFC. The maximum power density of MFC is 4.8 MW m ~ (-2) when the output current is decreasing continuously at .25 鈩，

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