| Phenol is a colorless crystal,toxic and corrosive.Phenol and its derivatives are easily soluble in water,and have strong conversion ability,which will cause serious pollution to the environment.In addition,the rapid development of society is facing the current situation of energy shortage.Therefore,from the point of view of energy and pollution,this paper through the constructed wetland-microbial fuel electricity(CW-MFC)to treat wastewater.The CW-MFC is a coupling technology emerging in recent years,using artificial wetland of redox gradient and microbial fuel cell(MFC)embedded in it,in the sewage treatment at the same time also can produce electricity,this to solve the current energy crisis and environmental crisis facing provides a train of thought.In this study,the CW-MFC coupling system was successfully constructed.Firstly,studied the purification of wastewater and the electrochemical performance of the coupling system under different water inlet COD concentration and HRT under the condition of glucose.In addition,the purification effect and electrochemical properties of the sewage under the substrate were studied with phenol and phenol +glucose co-substrate.In the end,the microorganism of the anode biofilm was sequenced under different substrate conditions,and the differences and changes of microbial community were analyzed.The main results are as follows:In the experiment,glucose was selected as the substrate and 50-450mg/L 5 groups of water inlet COD concentration were set to study the effect of COD concentration on the system performance.The experimental results showed that the CW-MFC was the best when the COD concentration was 350 mg/L.At this time,the removal rate of COD,NH4+-N and TP reached 95.7%,55.1%and 95.5%,and the output voltage was 646 mv,and the COD removal rate in the experimental group was about 3%higher than that in the control group.On the basis of this study,the water inlet COD concentration was kept at 350mg/L,and five groups of HRT were designed to study the effects of different HRT on the system.The results showed that,as the HRT decreased from 36h to 12h during the experiment,the removal efficiency of pollutants was the best when HRT was 36 h,and the removal rate of COD,NH4+-N and TP reached 96.56%,52.95%and 99.45%.The maximum output voltage is 646 mv and the maximum power density is 286.7 mw/m3.Secondly,phenol was selected as the target pollutant,and the purification and electrochemical properties of the system under the common matrix of single phenol and phenol and glucose were studied.Experimental results show that the CW-MFC coupling process can single phenol as the substrate to generate electricity,the phenol removal efficiency reached 73.41%,COD removal rate was 65.33%,the output voltage is 248 mv,and co-substrates glucose to join not only improves the output voltage but also improve the removal rate of phenol,the output voltage is 570 mv,phenol removal rate was 75.59%,the COD removal rate was 73.28%.In addition,the removal effect of phenol in the experimental group was better than that of the blank group,and the bioelectricity generation promoted the degradation of phenol.Finally,the experiments were conducted to sample the anode microorganisms under the substrate of glucose and phenol.The results showed that the community structure of anode microorganism was very different under different reactor and substrate conditions.The abundance of Firmicutes in the experimental group was much larger than that of the blank group,the experimental group was 18.33%to 51.49%,and the blank group was only 3.57%-11.26%.Although both the experimental group and the control group produced electricity,the bacteria in the experimental group were the dominant bacteria,and the abundance was far greater than that of the control group.Compared with phenol as substrate,the anode microbial community in different groups of reactors was found to be very different,and the degradation of phenol in the experimental group was more than that of the control group. |
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