Effects of Different Substrates on MEC Anode Film Formation and Extracellular Polymer

Abstract

In this paper, a single-cell microbial electrolysis cell (MEC) reactor is used, with activated sludge as the inoculum, glucose, sodium acetate, sodium propionate and sodium butyrate as substrates. The MEC anode film formation and the different nutritional conditions are studied for the influence of extracellular polymers. Experimental research shows that MECs running on different substrates show obvious current density and anode membrane electrochemical activity. MEC anode membrane current density of sodium acetate substrate culture is the highest (12.78 A/m2), followed by glucose and butyl Sodium and sodium propionate. MEC anode electroactive microorganisms can use a wide range of substrates. The energy efficiency of different substrates is different, and the energy efficiency of acetic acid is the highest. The electrochemical activity and hydrogen yield of the anode biofilm are the same as those of the MEC current density. Increasing the inoculum within a certain range is conducive to improving the electrochemical activity of the anode biofilm and the hydrogen yield of the anode film. Further analysis of the composition of the anode membrane biomass and extracellular polymer (EPS) showed that increasing the inoculation amount is beneficial to the increase of the anode membrane biomass. A large number of anode-attached bacteria can produce higher current density and EPS content. The protein in the anode membrane EPS The content is significantly higher than polysaccharides, and as the protein content increases, the electrical density also increases.