| Environmental pollution and energy crisis are the most important issues in today’s social development.Seeking a new type of clean energy which can be used continuously and does not produce pollution has become the focus of researchers from all over the world.Microbial fuel cells(MFC)can convert different types of organic matter directly into electrical energy through the oxidative decomposition of microorganisms.Different types of wastewater can be used as a source of MFC organic matter.MFC technology produces electricity while taking into account sewage treatment,which is a very ideal new clean energy.However,it is impractical for MFC to treat wastewater at the laboratory scale.It is impractical to design a larger MFC to Satisfy the needs of real-life wastewater treatment.However,in the process of scaling up,the decline of power density hinders the development of this process.In this thesis,the scale-up of MFC and the treatment of organic dyes-containing wastewater are investigated in detail.(1)The performance of multi-electrode array MFC during long-term operationIn this experiment,multi-electrode-pair array arrangement and multi-cathode array arrangement were designed.We focused on the electricity production,electrode resistance change and external resistance affect of three-volume-scale MFCs with multi-electrode-pair array arrangement for more than two years.The results show that the stable output voltage is hardly affected during long-term operation,and the anode ohmic resistance drops by 50%.The maximum power density has dropped by about 20%compared to two years ago.The MFC with a larger external resistance has dropped more significantly.A smaller external resistance makes the electroactive bioanode run at a higher current for a long time.It is beneficial to maintain the electrical activity of the bioanode during long-term operation.In addition,we also investigated the feasibility of multi-cathode array amplification.This MFC achieved a pleasing maximum power density of 23.5 W·m-3 after 90 days of operation.(2)Study on the removal of acid orange 7(AO7)by multi-cathode array arrangement MFCsThrough the configuration of a multi-cathode array arrangement MFCs to Satisfied the actual needs of long-term operation and large-scale wastewater treatment.Under long-term operation,the decolorization and degradation of AO7 and the electricity generation performance of MFCs were evaluated.No matter in the concentration of 50 mg/L or 100 mg/L,more than 98%of AO7 can be decolorized within 32 hours in the MFCs system,and its decolorization efficiency exceeds 98%.16sRNA was used to analyze the influence of the AO7 on the population of electroactive anode organisms.Ultraviolet-visible spectroscopy(UV)and Fourier infrared(FTIR)indicate that AO7 can achieve partial mineralization in this MFCs system.At the same time,this volume-amplified air cathode MFCs has the potential to realize large-scale sewage treatment.in real life.(3)Removal of Crystal Violet from dye Wastewater by MFCsThe experiment explored the microbial fuel cell technology to treat wastewater containing crystal violet.In the double-chamber MFCs anode,the crystal violet was successfully removed.The measurement results show that when the culture medium does not contain crystal violet,the dual-chamber MFC can generate a stable voltage of 0.47 V and a maximum power density of 11 W·m-3.With the addition of crystal violet added in the anode chamber,the output voltage,anode electric potential and the maximum power density show a gradual decrease trend.When the concentration of crystal violet is 25,50,and 75 mg/L,the maximum power density decreases by 9.1%,respectively.23.5%,40.0%.The removal rate of crystal violet is also affected by the concentration of crystal violet.When the concentration of crystal violet is below 50 mg/L,its removal efficiency is above 85%.When the concentration continues to increase to 75 mg/L,its removal efficiency drops nearly 40%.This provides an idea for the degradation of triphenylalkyls dyes. |
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