不同阴极微生物脱盐电池处理榨菜废水性能及微生物群落分析

Performance and microbial community analysis in microbial desalination cells with different cathodes for mustard tuber wasterwater treatmment

为处理高盐榨菜废水(mustard tuber wastewater treatment,MTWW),实现系统同步产电脱盐的目的,构建了以生物电化学为基础的微生物脱盐燃料电池(microbial desalination cell,MDC),探讨了铁氰化钾和水阴极MDC产电及脱盐效果,并对系统微生物群落进行了分析。结果表明:在相同脱盐时间内,铁氰化钾组盐度去除率为90.30%,略高于水阴极组;在整个脱盐周期内,铁氰化钾组产电性能优于水阴极组;随着脱盐时间的延长,铁氰化钾组产电性能略有下降,而水阴极组产电性能显著增强;铁氰化钾组阳极优势菌属为Methanosaeta(23.55%)、Geobacter(14.09%)和vadin HA17(8.64%),水阴极组阳极优势菌属为vadin HA17(18.17%)、Methanosaeta(13.00%)和Methanosaeta(9.79%),其中Geobacter为产电菌,vadin HA17为水解发酵菌,Methanosaeta和Methanosaeta为常见产甲烷菌。铁氰化钾组阳极和水阴极组阳极中产甲烷菌占比很高,然而,产甲烷菌对系统产电脱盐有不利作用,因此,有必要寻找合适的抑制产甲烷菌产生的方法。运行后期,水阴极组阴极中出现了产电菌,极大地降低了阴极过电势,提高了系统的产电性能。上述研究结果可为MTWW的资源化处理提供参考。

To realize the purpose of simultaneous electricity generation and salt removal,the microbial desalination cell(MDC)based on bioelectrochemistry was constructed for mustard tuber wastewater treatment(MTWW).In this study,the electricity generation and salt removal of potassium ferricyanide and water-cathode MDC were examined,and the microbial community in the sytem was analyzed.The results showed that within the same desalination time,the salt removal rate of the potassium ferricyanide group was90.30%,being slightly higher than that of the water-cathode group.Over the entire desalination cycle,the electricity generation of the potassium ferricyanide group was better than that of water-cathode group.With the extension of desalinization time,the electricity generation of the potassium ferricyanide group decreased slightly,while the electricity generation of water-cathode group increased significantly.Methanosaeta(23.55%),Geobacter(14.09%)and vadin HA17(8.64%)were the dominant bacteria in anodic biofilm of the potassium ferricyanide group,while vadin HA17(18.17%),Methanosaeta(13.00%)and Methanosaeta(9.79%)were the dominant bacteria in cathodic biofilm of the water-cathode group.Of which Geobacter belongs to electrgenic bacteria,vadin HA17 belongs to hydrolyzed fermentation bacteria,Methanosaeta and Methanosaeta belong to methanogens.The abundance of methanogens in the anodic biofilm of the potassium ferricyanide group and water-cathode group was pretty high.However,the methanogens have an adverse effect on electricity generation and salt removal,therefore,it is necessary to find a suitable method for inhibiting the generation of methanogens.At the later stage of operation,the electrogenic bacteria appeared in the cathode of the watercathode group,which greatly reduced the cathode overpotential and improved the electricity generation of the system.This study provides a reference for resuorce utilization of MTWW.