厌氧流化床无膜微生物燃料电池的床层膨胀高度与产电特性

Effect of Bed Expansion Height on Electrogenesis Capacity of Anaerobic Fluidized Bed Membraneless Microbial Fuel Cell

考察了厌氧流化床床层膨胀高度对电池不同阴极位置(阴极1,2,3分别位于分布板上方150,250,350mm)产电性能的影响.膨胀高度低于170mm时,电池功率随阴极位置沿轴向高度增加而减小,同一流速下,阴极1的最大电极输出功率最大,为347.1mW/m2.膨胀高度在170～270mm时,同一流速下,阴极2的最大产电功率高于阴极1和阴极3,当流速为8.35mm/s时,达361.0mW/m2.膨胀高度在400mm以下,同一流速下3处阴极的最大产电功率均降低,阴极3最大产电功率降低幅度较小,为297.5mW/m2,电池功率随阴极位置沿轴向高度增加而增大.该结果是流速对阳极室内传质及电子传递效率、流速对微生物膜生长双重影响的结果.

Anaerobic fluidized bed microbial fuel cell（MFC） with 40 mm in diameter and 600 mm in height was employed to investigate the effect of fluidization bed expansion on the electrogenesis capacity of MFC.Three different cathodes were investigated for cathode positions at 150,250 and 350 mm above distributor.When the expansion height was less than 170 mm,the electrogenesis capacity at cathode 1 was the maximum,up to 347.1 mW/m2.The power density decreased with decreasing cathode position along the bed height.When the expansion height ranged from 170 to 270 mm.The electrogenesis capacity at cathode 2 was larger than that at cathodes 1 and 3,which approached 361.0 mW/m2 when the flow rate of wastewater was kept at 8.35 mm/s.When the expansion height of fluidization bed was 270 to 400 mm,the electrogenesis capacity of three cathodes was all decreased.However,cathode 3 had a minimum decline value,297.5 mW/m2 at the flow rate of wastewater of 10.61 mm/s.The power density increased with increasing cathode position along the bed height.The results were due to the effects of the flow rate on the mass and electron transport efficiency in anode chamber,and the effects of the flow rate on the growth of microbial film.