改性生物质活性炭空气阴极MDC性能及微生物分析

Performance and Microbiological Analysis of Modified Biomass Activated Carbon Air Cathode MDC

构建了三室空气阴极微生物脱盐燃料电池(MDC)系统处理榨菜废水。对比了3种阴极催化剂(商品化铂碳(Pt/C)、载锰改性废菌渣活性炭(Mn-MRAC)、铁锰改性废菌渣活性炭(Fe/Mn-MRAC))的MDC产电、脱盐性能及阳极生物膜微生物群落的差异。结果表明,在产电与脱盐性能方面,Mn-MRAC在外电阻1000Ω的负载下,输出电压、最大功率密度、库伦效率和脱盐速率分别为574 mV、2.59 W/m^3、(26.0±0.9)%和5.39 mg/h,其效果与Pt/C相似,但成本大大降低。Fe/Mn-MRAC的效果则与上述2者相差较大。这为用单金属元素锰改性废菌渣活性炭替代商用铂碳成为空气阴极催化剂提供了实践支持。高通量测序分析表明,3组MDC系统的阳极生物膜中产电菌种类相似但丰度不同,分别为80.93%的(Pt/C)、78.75%的(Mn-MRAC)和72.09%的(Fe/Mn-MRAC)。水解发酵菌属为榨菜废水MDC阳极的核心微生物群落。同时在3组阳极生物膜中发现了反硝化菌属,证明阳极可能存在反硝化反应。

Air-cathode microbial desalination cell(MDC)of three-chamber mustard wastewater were constructed.The electricity generation,desalination and microbial community of anode biofilm in MDC under three kinds of cathode catalysts(Pt/C,Mn-MRAC,Fe/Mn-MRAC)were compared.The results revealed that in terms of electricity generation and desalination performance,the effect of Mn-MRAC is slightly lower than Pt/C,but its cost is greatly reduced.The output voltage,power density,coulombic efficiency and desalination rate of the 1000Ωexternal resistors are574 mV,2.59 W/m^3,(26.0±0.9)%and 5.39 mg/h,respectively.The effect of Fe/Mn-MRAC is quite different from the above two.This provides practical support for the replacement of commercial Pt/C with Mn-MRAC to become air cathode catalysts.The high-throughput sequencing analysis indicated that the types of electrogenic bacteria in the anode biofilm of the three MDC systems were similar but the abundance was different.The total abundance of the electrogenic bacteria was 80.93%(Pt/C),78.75%(Mn-MRAC)and 72.09%(Fe/Mn-MRAC),respectively.The difference in abundance of electrogenic bacteria may be the main reason for the difference in electricity generation performance.The hydrolysis fermentation bacteria are the anode core bacteria of the MDC.At the same time,denitrifying genus were found in three groups of anode biofilms,which proved that there may be denitrification in the anode.