| SMFC is a new method by using electricity bacteria who can obtain electricity and from the substrate to remove contaminants,which is also the most direct way to recover energy from litter or waste water.Its anode buried in sediments using humus,sulfide and other reductive pollutants in sediments as an electron donor and its cathode was in the overlying water,which can use the nitrate,perchlorate,heavy metal ions and other oxidizing pollutants as electronic receptors.The particularity of this structure and the new pattern of reactivity make it possible to achieve simultaneous bioremediation of sediments and overlying water and produce electrical energy meanwhile.Besides,its mobility was strong and can be used in rivers,lakes and other natural water withOTU external electron donors or receptors.So it has a great application prospects.Plant-sediment microbial fuel cell is the combination of plant and sediment microbial fuel cell,using the photosynthesis of plants to synthesize organic substances such as glucose and to strengthen SMFC production.However,the practical application of SMFC need to overcome some shortcomings such as unstable performance low OTUput power.In this study,the SMFC system was constructed by using the sediment and overlying water with TP concentration of 0.2mg/L to explore the influence of plants and ferrous ions on the migration and transformation of phosphorus and the influence of the power generation performance in the SMFC system.In addition,high-throughput sequencing method was used to analyze the biodiversity and functional diversity in the anodic sediments,and the changes in phosphorus morphology were explored from the microenvironment and microbiological perspective.The main experimental contents and results are as follows:(1)The SMFC system was constructed by using sediments and water in the black-odor lake to achieve the enrichment of the electricity producing bacteria.It was found that the voltage reached the stability at 240 h SMFC system,and the enrichment of the electricity producing bacteria was successful.(2)The influence of plants and ferrous ions on the power generation performance of P-SMFC system were investigated.The current density and power density of P-SMFC systems with plants were higher than those of SMFC system withOTU plants,which indicated that plants can promote the electricity generation process of P-SMFC system.Also,the output voltage,current density and power density of P-SMFC system were increasing with the increase of ferrous ion concentration.(3)The effects of plants and ferrous ions on total phosphorus removal efficiency in P-SMFC system were investigated.The results showed that the cumulative removal efficiency of total phosphorus by P-SMFC system was higher than that of SMFC without plant.The cumulative removal efficiency of total phosphorus was the highest at 39.55% under the condition of P-SMFC and the ferrous ion concentration of 5mg/L,and the least at 29.57% under the condition of SMFC without plant and ferrous ion.It is not conducive to P-SMFC removal of phosphorus when ferrous ion concentration is too high or too low.(4)The effects of plants and ferrous ions on organic matter removal efficiency in P-SMFC system were investigated.The results showed that the cumulative removal efficiency of organic matter by P-SMFC system was higher than that of SMFC without plant.The cumulative removal efficiency of organic matter was the highest at 84.13% under the condition of P-SMFC and the ferrous ion concentration of 5mg/L,and the least at 77.78% under the condition of SMFC without plant and ferrous ion.(5)The effects of plants and ferrous ions on the migration and transformation of phosphorus in P-SMFC system were investigated.The results showed that plants promoted the mineralization of organophosphorus,making the content of Fe-P,Al-P and Ca-P in P-SMFC system was higher than that in SMFC system without plant.Also,the iron ions increase the initial content of iron.The absorption of plants,the mineralization of organic matter and the absorption of iron oxide / hydroxide to phosphorus made the change of Fe-P content more obvious than that of Al-P and Ca-P.(6)There are rich species diversities in anodic sediment.The dominant categories in bacteria were Proteobacteria,Chloroflexi,Bacteroidetes e.(7)Additional ferrous ions may lead to more specific microorganism in sediments,and the influence of ferrous ions on microbial diversity in sediments was greater than that of plants on the microbial diversity in sediments.In this paper,the influence of plants and ferrous ions on the migration and transformation of phosphorus and the influence of the power generation performance in the SMFC system were studied,which had important academic and provided significance theoretical support for the practical application of SMFC as the technology of in situ repair and recovery of electrical energy. |
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