为了提高微生物燃料电池(MFC)对沼液中有机质的降解和产电效率,将纳米Fe3O4与MFC结合,考察了纳米Fe3O4 以Fe3O4@生物炭和Fe3O4@碳毡两种不同介入方式对MFC性能的影响.结果表明,两种方式均可成功启动MFC,且产电效率远高于无纳米Fe3O4介入的空白实验,最高电压分别为699和707 mV,最高电压持续时间均可长达10 d.Fe3O4@碳毡与Fe3O4@生物炭介入下,MFC最大功率密度分别为700和578 mW/m2,比未使用纳米Fe3O4的MFC提高了43%和31%.将Fe3O4@碳毡作为阳极电极得到的化学需氧量(COD)降解率最高,为 51.76%;直接投加 Fe3O4@生物炭对 NH4+-N 的降解影响最大,投加 Fe3O4@生物炭后 NH4+-N 含量由(6800.14±57.86)mg/L降至(689.14±37.29)mg/L,NH4+-N降解率达到89.87%.纳米Fe3O4参与的MFC微生物群落结构合理,两种介入方式均刺激了主要水解细菌梭菌纲(Clostridia)的生长富集.随着纳米 Fe3O4 的位置变化,Clostridia的相对丰度在以Fe3O4@生物炭和Fe3O4@碳毡介入的MFC中分别达到61.11%、50.98%.二者的电活化细菌中 β-变形菌纲(Betaproteobacteria)含量最高,并且在反应后碳毡上发现了反硝化细菌芽孢八叠球菌属(Sporosarcina).
In order to improve the organic matter degradation in biogas slurry and electricity production of microbial fuel cell(MFC),nano-Fe3O4 was combined with MFC via two different intervention methods by loading nano-Fe3O4 on anode carbon felt(Fe3O4@carbon felt)and loading nano-Fe3O4 on biochar(Fe3O4@biochar)into the anode chamber.The influence of these two intervention methods on the performance of MFCs were investigated.The results showed that MFC could be started by both methods,and exhibited much higher electrogeneration efficiency compared with MFC without nano-Fe3O4 intervention.The MFC treated with Fe3O4 showed maximum voltage of 699 and 707 mV,respectively,with the maximum voltage lasted up to 10 d.The maximum power density was increased by 43%in the Fe3O4@carbon felt(700 mW/m2)and 31%in the Fe3O4@biochar(578 mW/m2)in comparison to that MFC without Fe3O4 nanoparticles.The highest chemical oxygen demand(COD)degradation rate(51.76%)was obtained using Fe3O4@carbon felt as anode electrode.Direct application of Fe3O4@biochar showed the greatest effect on the degradation of NH4+-N,with degradation rate of 89.87%,the NH4+-N decreased from(6800.14±57.86)mg/L to(689.14±37.29)mg/L after the application of Fe3O4@biochar.The microbial community structure of the MFC with the participation of nano-Fe3O4 tended to be rationalized.Both participation methods stimulated the growth of the main hydrolytic bacteria(Clostridia).With the position of nano-Fe3O4 changing,the relative abundance of Clostridia in the MFC with Fe3O4@biochar directly inputting into the anode chamber and the MFC with Fe3O4@carbon felt as anode electrode reached to 61.11%and 50.98%,respectively.Both had the highest content of Betaproteobacteria in electroactivation and denitrifying bacteria Sporosarcina was found on the post-reaction carbon felt.