Constructed wetlands(CWs)are widely used as a tertiary treatment technology,and the addition of carbon sources can significantly improve advanced nitrogen removal.However,excessive carbon sources would lead to an increase in the effluent chemical oxygen demand in CWs,and microbial fuel cells(MFCs)can convert these into electricity.In this study,constructed wetland-microbial fuel cells(CW-MFCs)were built to achieve simultaneous nitrogen removal and electricity generation,using wetland plant litter fermentation broths as carbon sources.The total nitrogen removal in the groups with fermentation broth addition(FGs)reached 83.33％,which was 19.64％higher than that in the CG(group without fermentation broth),and the mean voltages in the FGs were at least 2.6 times higher than that of the CG.Furthermore,two main components of the fermentation broths,acetic acid(Ac)and humic acid(HA),were identified using a three-dimensional excitation emission matrix and gas chromatograph and added to CW-MFCs to explore the influence mechanism on the treatment performance.Denitrification and electrogenesis presented the same tendency:Ac&HA＞Ac＞CG'(groups without Ac and HA).These results indicate that Ac and HA increased the abundance of functional genes associated with nitrogen metabolism and electron transfer.This study demonstrated that CW-MFC fermentation broth addition can be a potential strategy for the disposal of secondary effluent and bioelectricity generation.

Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment(Ministry of Education),Chongqing University,Chongqing 400045,China;College of Environment and Ecology,Chongqing University,Chongqing 400045,China

[1]Yiting Chen;Jun Yan;Mengli Chen;Fucheng Guo;Tao Liu;Yi Chen-.Effect of wetland plant fermentation broth on nitrogen removal and bioenergy generation in constructed wetland-microbial fuel cells)[J].环境科学与工程前沿,2022(12):86-97

CWs,broths,electrogenesis

Effect,plant,fermentation,nitrogen,removal,bioenergy,generation,constructed,microbial,fuel,cells,Constructed,wetlands,are,widely,used,tertiary,treatment,technology,addition,carbon,sources,significantly,improve,advanced,However,excessive,would,lead,effluent,chemical,oxygen,demand,MFCs,convert,these,into,In,this,study,were,built,achieve,simultaneous,using,litter,total,groups,FGs,reached,which,was,higher,than,that,CG,without,mean,voltages,least,times,Furthermore,two,main,components,acetic,acid,Ac,humic,HA,identified,three,dimensional,excitation,emission,matrix,gas,chromatograph,added,explore,influence,mechanism,performance,Denitrification,presented,same,tendency,These,results,indicate,increased,abundance,functional,associated,metabolism,electron,transfer,This,demonstrated,be,potential,strategy,disposal,secondary,bioelectricity

0.477005