Study On Removal Of Antibiotic And Control Of Antibiotic Resistance Genes By The Combined Technology Of Bio-film Electrode Reactor And Microbial Fuel Cell-constructed Wetland

Since constructed wetland(CW)and microbial fuel cell(MFC)possess great potential in purification of refractory organics,therefore,this paper presented a novel microbial fuel cell-constructed wetland(MFC-CW)with combination of both structures.Simultaneously,bio-film electrode reactor(BER)was used as pre-treatment prior to MFC-CW,and the bioavailability of wastewater could be improved by the co-operative function of electrochemical action and biological process,then the removal efficiency of refractory organics and the electricity production performance in the MFC-CW were promoted.Moreover,electricity energy generated by MFC-CW was supplied to BER,and the MFC-CW system achieved the exchange of substance and energy.Simultaneously,the general combination system BER-MFC-CW is constructed.The electricity energy generated by MFC-CW was not supplied to BER,whose required power was supplied directly from the DC power.In this paper,sulfamethoxazole(SMX)is set as the target contaminants,we mainly studied the effect of sulfamethoxazole concentration,running time,HRT on the removal of antibiotics in different BER-MFC-CW systems as well as the changes of ARGs in the effluent and filler and microbial diversity in systems.Main research achievements were as followings:(1)The double substance and energy coupling system BER-MFC-CW,with the increase of SMX concentration and e decrease of HRT,the system voltage was increased.BER-MFC-CW had a good capability of removing SMX,the removal efficiency of antibiotics can reach up to 95%.The removal efficiency of SMX increased with the increasing of HRT.The removal efficiency of antibiotics in MFC-CW reactor remained stable which was as high as 95%,regardless of the difference of HRT.In the MFC-CW reactor,the removal of mainly occurred in the anode.(2)The orders of relative abundance of sul resistance gene in the effluent and filter of BER,MFC-CW was sull>sulll>sulⅢ,and the relative abundance of sul gene in the filler was higher than that of sul gene in effluent.With the increase of SMX concentration,the relative abundance of sul resistance gene in BER and MFC-CW effluent and filter increased,with the increasing of HRT,the relative abundance of sul resistance gene in the effluent and filter of BER and MFC-CW decreased.The relative abundance of sul resistance gene in BER>the relative abundance of sul resistance genes in MFC,and the abundance of the resistance gene in the each unit of general combination system of BER-MFC-CW>The double substance and energy coupling system of BER-MFC-CW.The abundance of anode and cathode zones of resistance genes was larger than the abundance of resistance genes in microorganisms cushion zone.(3)With 30 days’ running,the microbial richness and diversity in BER and MFC-CW were improved compared to original samples;but when the running time was 60d,the microbial richness and diversity in BER and MFC-CW were reduced,the anode cathode area of MFC-CW is higher than the anaerobic aerobic zone.Microbial richness and diversity in BER were reduced with the decreasing of HRT,the microbial richness and diversity of the filler in MFC-CW was reduced with the decreasing of HRT.(4)Analysis into the genus level of the main anode bacterial namely Geobacter in MFC-CW showed that,the relative abundance of Geobacter in MFC-CW decreased with the effect of SMX and the running time,while the performance of MFC-CW also decreased.With the decreasing of HRT,Geobacter in the MFC-CW anode area increased,the production performance of MFC-CW also increased.