Enhanced Removal Of Pollutants In Black-Odor Water By Sediment Microbial Fuel Cell

Black-odor water is an extreme phenomenon of water pollution.Due to the frequent occurrence of black-odor water in recent years,it has received extensive attention.At present,China has made great progress and achievements in the area of treatment of black-odor water,but there are still some shortcomings in the issue of sediment recovery and the recycling of pollutant resource.In recent years,sediment microbial fuel cells（SMFC）has been widely concerned because of its simultaneous realization of pollutant removal and energy recovery in sediments.However,higher pollutant removal efficiency and higher electrogenesis performance are still important issues in the process of industrialization of microbial electrochemical methods.Due to the structural characteristics and performance of SMFC,the efficiency of electricity production in the system and the removal rate of nitrogen and phosphorus are still not high enough.Therefore,the cells performance and contaminants conversion rate can be improved by optimizing the configuration and structure of the reactor and adding molecular sieves,which has important theoretical significance and application value for optimizing microbial electrochemical treatment process and its realization of industrial production.In view of the problems existing in the current industrialization process of sediment microbial fuel cells,it was discussed that the effects of the modification of cathode and the addition of zeolites on the performance of SMFC.The material structure of the modified cathode surface was initially observed,and it was explored that the relationship between characteristics of cathode surface and battery efficiency.In order to establish a more efficient electrical energy conversion system,this study compared the performance of different cathode systems under the same experimental conditions.The modified manganese dioxide（MnO₂）/tourmaline cathode SMFC system can simultaneously ensure higher pollutant removal efficiency and more efficient power recovery.The MnO₂/tourmaline cathode reactor has the best electricity production performance,and the electricity production voltage is the highest in the closed circuit system,which is 0.384 V,and the power density reaches 329.1 mw/m³,which is 1.27times and 1.62 times of the MnO₂ cathode component and the biocathode component,respectively.The TOC removal rate of each system is positively correlated with the electricity production voltage.In this experiment,the overlying water and sediments of different cathode systems at the same height were collected,and the TOC content of the two were tested.The results showed that the MnO₂/tourmaline cathodic system has the best performance,the total TOC removal rate of the entire system is about 52%,slightly higher than the MnO2 cathode system.When the removal of ammonia nitrogen by different systems was investigated,it was found that the ammonia nitrogen of the open circuit system was always higher during the experiment.The MnO₂/tourmaline cathodic system reduced the ammonia nitrogen concentration from 4.95 mg/L to about 0.2 mg/L,and the ammonia nitrogen removal rate exceeded 90%.Through the total amount and ratio of protein and polysaccharide,it can be concluded that the system loaded with MnO₂/tourmaline cathode has the greatest influence on the sludge properties,and the protein to polysaccharide mass ratio is 1.7 times that of the open circuit system.Therefore,considering the power generation performance,organic pollutant removal efficiency and positive impact on sediments,MnO₂/tourmaline cathodic deposition microbial fuel cell system can maintain high Organic pollutant removal efficiency while ensuring high pressure output.In order to further improve the performance of the SMFC,the same quality zeolite molecular sieve was added in it.The open/zeolite group,the closed circuit group and the closed circuit/zeolite group were compared with the open circuit group.The results showed that the addition of zeolite did not significantly change the SMFC production.However,in terms of organic matter removal,the closed-circuit/zeolite group exhibited better performance in overlying water TOC,sediment TOC,and nitrogen and phosphorus removal.The removal rate of overlying water TOC reached 50.76%,which were 1.07,1.56 and 2.29 times of the closed circuit group,the open circuit group and the open circuit/zeolite group,respectively.The removal rate of sediment TOC reached 49.15%,and the removal rate of ammonia nitrogen reached 94.62%.Therefore,it is found through this experiment that,the tourmaline modified cathode has a promoting effect on the electricity generation and organic matter removal of the deposited fuel cell,and the zeolite has a good promoting effect on the deposition fuel cell,and the two methods can be combined and optimized to optimize the SMFC process.