4种湿地植物-微生物燃料电池产电性能比较

Electricity Generation Performance of Plant Microbial Fuel Cells Separately Constructed by Four Wetland Plants

【目的】植物-微生物燃料电池(P-MFC)是一种可持续的可再生能源生产方式,但不同植物构建的P-MFC产电效果及其与外界环境条件和植物个体生理之间的关系仍有待探索。【方法】以巴拉草(Brachiaria mutica)、短叶茳芏(Cyperus malaccensis var.brevifolius)、多枝扁莎(Pycreus polystachyus)、双穗雀稗(Paspalum paspaloides)4种湿地植物为材料构建P-MFC,比较不同P-MFC的产电性能,分析P-MFC产电性能与植物自身根系渗氧生理和外界环境因素(pH、溶解氧和温度)之间的关系。【结果】4种不同植物构建的P-MFC产电性能差异明显,平均功率密度分别为:巴拉草4.25(±0.35)mW/m2、短叶茳芏1.57(±0.35)mW/m2、多枝扁莎0.20(±0.09)mW/m2、双穗雀稗4.38(±0.56)mW/m2;巴拉草和双穗雀稗P-MFC产电能力较强,这与巴拉草根系渗氧速率较低、双穗雀稗阴极pH较低且较稳定有关;低根系渗氧率有利于维持低阳极电位,阴极低pH环境有利于维持较高阴极电位,从而使得电池整体输出电压较高。【结论】在利用湿地植物构建P-MFC时,植物根系特点尤其是根系渗氧生理是需要重点考虑的因素。

【Objective】Plant-microbial fuel cell(P-MFC)is a sustainable way for renewable energy production,but the electricity generation performance of P-MFC constructed by different plants and its relationship with external environmental factors and individual plant physiology remains to be explored.【Method】In this study,different P-MFCs were constructed by 4 wetland plants,including Brachiaria mutica,Cyperus malaccensis var.brevifolius,Pycreus polystachyus and Paspalum paspaloides.The performance of P-MFCs and their relationships with radial oxygen loss(ROL)and external environmental factors(pH,dissolved oxygen and temperature)were analyzed.【Result】The results showed that the 4 constructed P-MFCs had significantly different performance in voltage output,the average voltage output were 4.25±0.35,1.57±0.35,0.20±0.09 and 4.38±0.56 mW/m2 for B.mutica,C.malaccensis var.brevifolius,P.polystachyus and P.paspaloides,respectively.P-MFCs constructed with B.mutica and P.paspaloides produced more energy in general This may be related to the lower rate of oxygen loss of B.mutica and the lower and stable pH in the cathode of P.paspaloides-MFC.The lower ROL helped to maintain a lower anode potential in B.mutica-MFC,while the lower cathode pH environment contributed to the higher cathode potential in P.paspaloides-MFC.【Conclusion】When constructing P-MFCs from wetland plants,the root features especially the root oxygen physiology should be taken into consideration.