Research On Cu(Ⅱ) Treatment In Wastewater By Microbial Fuel Cell(MFC)Modified With Graphene

Microbial fuel cell(MFC) can convert biological organic energy into electrical energy via microorganisms in natural environment, and at the same time it can produce H2, C H4 and such other energy. MFC is a kind of wastewater treatment technology, which combines power production, capacity and removal. Using MFC to deal with heavy metal waste water can not only achieve the goal of removal, but also can generate electricity. It is a low toxic and energy- saving technology. But due to its high cost and other issues the MFC application still have a long way to go, and to find alternative laboratory study of traditional catalyst noble metal catalyst Pt is the important way to solve. Since the discovery of graphene, due to its high specific surface area, high electron transfer rate and other unique properties, it has attracted the attention of various industries. These properties of graphene are very benefic ial to the adhesion and reaction of microorganisms in the MFC. Compared with the non-biological cathode in the MFC biological cathode, there is an incomparable advantage in the cost and environmental friendliness. Therefore, the research on the biological cathode is also a key point.This experiment applied graphene to the MFC in order to find a way to the bottleneck of MFC. In the past, the MFC removal of heavy metals in a two compartment were in the majority, in this expertiment we used the more simple, the single chamber, cathode using the biological cathode MFC, to expect to find ways to improve the power density and the removal effect. Specific content as follows:We used unmodified graphene and platinum carbon as cathode catalysts of single room MFC to treat the copper containing wastewater. However, the response current of the C V map of unmodified graphene was larger than that Pt, which indicated that the unmodified graphene had a higher electron transfer rate and better electrical conductivity. But it was not suitable to be used as the cathode catalyst of MFC directly.The Fe and N were modified to graphene by thermal polymerization, and then the modified graphene was used as the cathode catalyst of MFC to treat the simulated wastewater containing copper. The results showed that the copper removal effect of modified graphene cathode was slight ly better than platinum carbon, far higher than untreated graphene and the tolerance of copper slightly higher than platinum carbon, much higher than that of unmodified graphene. The modified graphene as a microbial fuel cell catalyst, the output voltage and the maximum power density was 0.56 V and 34.38 W/m3, respectively, slight ly higher than the platinum carbon. And the response current of modified graphene C V map was larger than that of platinum carbon. Modified graphene had a higher electron transfer rate and better conductive performance. From the study, the modified graphene can be used as a cathode catalyst for MFC.For a more thorough understanding the types of microorganisms in the MFC and in the removal process, Illumina high- throughput sequencing was used to analys is the microorganisms of the anode and cathode. It was found that the microbial population of the sample had a certain difference because of the catalys, and the microorganis ms of the anode was mainly dominated by Geobacter. sp. Under the condition of high concentration of copper, the microbial diversity was low. The Azoarcus had a certain effect on the removal of copper, Petrimonas, Pseudomonas and so on, also had the function to the S removal. The species of the cathode microorganis m were more complex, in the modified graphene Azoarcus was a high proportion, especially in the treatment of copper wastewater reactor.