电极改性对电极生物膜反硝化反应器硝酸盐氮去除性能的影响

探究在碳纤维毡电极上利用恒电压电化学聚合聚吡咯(PPy)的聚合效果,并利用傅里叶变换红外线(FTIR)及扫描电镜(SEM)对其进行表征;将聚吡咯覆膜改性后的碳纤维毡电极应用到自养反硝化的电极生物膜反应器(BER)中,考察电极改性对自养反硝化电极生物膜反应器的硝酸盐氮去除性能影响,并研究电极改性对生物膜附着量及生物膜微生物群落的影响。结果表明,恒电压电化学聚合能够在碳纤维电极表面形成均匀稳定的聚吡咯膜,从而实现聚吡咯在炭纤维毡电极上的覆膜改性。改性后的电极应用到自养反硝化电极生物膜反应器中,可使反应器对NO3--N的去除效率由对照反应器的67.3%增加到83.9%,处理效果提高了24.7%。对反应器内电极生物膜进行生物量测定和扫描电镜分析,可以看到R2反应器中改性电极生物膜附着量明显多于R1反应器中未改性电极生物膜的附着量,说明电极改性有利于生物膜的附着。电极生物膜微生物16S rDNA分析中R1反应器电极生物膜菌落组成中优势菌属为Dechloromonas sp.,而R2反应器电极生物膜的优势菌为Hydrogenophaga sp.(噬氢菌属)和Thauera sp.(陶厄氏菌属),两者有明显差别,并且R2反应器比R1反应器生物膜的菌落组成更多样化,这说明电极材料的改性对电极生物膜微生物群落的组成产生了影响。

Effects of electrode modification on nitrate removal of hydrogenotrophic denitrification in biofilm electrode reactor

The effect of polypyrrole(PPy) film electropolymerization on carbon felt(CF) electrodes using the potentiostatic method was investigated,and the composite was characterized by scanning electron microscopy(SEM) and Fourier transform infrared(FTIR) spectroscopy.The modified electrode was further applied in a biofilm-electrode hydrogenotrophic denitrification reactor,and its effects on the NO3--N removal performance of the reactor and the adhesion and microbial community of the biofilm were also examined.The PPy films formed evenly and stably on the CF electrode using the potentiostatic electropolymerization method.Compared with the control reactor,the NO3--N removal rate of the modified biofilm-electrode hydrogenotrophic denitrification reactor was enhanced by 24.7%.SEM and 16S rDNA analyses were performed to analyze the structures and communities of the biofilm on the electrode.More biomass was attached to the modified R2 electrode,which indicated that the approach presented here could improve bacterial adhesion on the cathode.A 16S rDNA analysis indicated that Hydrogenophaga sp.and Thauera sp.were the dominant isolates in R2,which was different from R1,in which the dominant isolate was Dechloromonas sp.Moreover,the microbial communities of the biofilm on the modified R2 electrode were more diverse than that of the control in R1.