Degradation Of Phenanthrene In The Environment Based On Microbial Fuel Cells

With the development of society,people's dependence on fossil fuels has gradually increased and a large amount of polycyclic aromatic hydrocarbons had been produced during the combustion process.It is difficult for polycyclic aromatic hydrocarbons to degrade in the natural environment and lead the content gradually increases in the environment,which would poses a great poisonous to the ecological environment.Recent researches on degradation refractory pollutants by using microbial fuel cells(MFCs)in the environment have been widely concerned.MFC is a device that can convert chemical energy into electrical energy.When various organic pollutants are used as substrates,the process of degrading organic pollutants and the process of generating electrical energy can be synchronized,which is a pollution treatment technology with broad application prospects.Based on this,phenanthrene was selected as the representative of polycyclic aromatic hydrocarbons in this study.To study the removal method of phenanthrene pollutants in water and soil,we construct corresponding microbial fuel cells to treat Philippine-contaminated water and soil respectively.Through the experimental data,the removal effect of phenanthrene and the power generation efficiency of the battery,the microbial community structure and the main functional microorganisms were analyzed.It provides a theoretical basis for the construction of microbial fuel cells for the removal of polycyclic aromatic hydrocarbons in contaminated water and soil.The main conclusions of this article are as follows:1.Construct an MFC that can remove phenanthrene pollutants in water.The activated anaerobic sludge from the sewage treatment plant were used as the source of microorganisms.After a long period of domestication and cultivation,the experiment was officially carried out.The battery was operated for eight days as a cycle,and four experimental groups were set.The initial concentrations of phenanthrene were 0 mg/L,5 mg/L,10 mg/L and 10 mg/L(phenanthrene's isotope treatment group).The final TOC removal rate of the experimental group were: 42.61 ±4.42%,54.14±2.88%,90.34±0.76% and 93.92±3.16%;the removal rate of COD was 36.17±8.95%,76.26±4.65%,82.77±2.10% and 80.26±1.68%;the removal rates of phenanthrene were: 68.86±1.93%,87.91±3.23% and 84.96±2.75%;in terms of power generation performance,the highest current reached 0.04 m A,0.32 m A,0.51 m A and 0.42 m A.It shows that microorganisms can adapt to different concentrations and different types of phenanthrene,and the peak value of current is not much different.The analysis of the microbial community structure by high-throughput sequencing technology showed that the main microbial communities in the non-isotopic experimental group were mainly Microbacter,Burkholdena-Caballeronia-Paranurkholderia,Bacillus,Geobacter,but the main microbial groups in the isotope experimental group were Xanthobacter,Hyphomicrobium and IMCC26207.2.Construct an MFC that can remove phenanthrene's pollutants in the soil.Inoculated paddy soil as a source of microorganisms and domestication and cultivation for a long period,the experiment was officially conducted.The battery runs for eight days as a cycle.Four experimental groups were set up,and the initial concentrations of phenanthrene were 0 mg/L,5 mg/L,10 mg/L and 10 mg/L(phenanthrene's isotope treatment group).The final TOC removal rates of the experimental group were: 24.93±4.62%,54.77±0.19%,74.60±3.71%and 14.50±56%;COD removal rates were 26.82±3.92% and 58.72±5.91%,77.18 ± 4.81% and 42.02 ± 4.31%;the removal rates of phenanthrene were: 49.80±8.46%,63.51±7.18% and 36.36±1.84%;in terms of power generation performance,the highest current reached 0.008 m A,0.094 m A,0.11 m A and 0.01 m A.It shows that the soil microorganisms have different utilization rates of different concentrations and different types of phenanthrene,resulting in a significant difference in peak current.Finally,the analysis of the microbial community structure by high-throughput sequencing technology showed that the main microbial community differed greatly by adding different types of phenanthrene.The microbial community of its non-isotopic experimental group was Microbacter and Burkholdena-Caballeronia-Paranurkholderia,while the main microbial group of isotopic experimental treatment is Azospirillum,MM2 and Desuifosporoinus.