Fig. 5: Electrochemical response of EPS.

a Proteins and polysaccharides concentration of slime layer, LB-EPS layer, and TB-EPS layer of sludge around the membrane in the three reactors during the stable period. Error bars represent the standard deviation of the EPS concentration results, which were measured after being extracted three times from the sludge of each reactor. b Fourier transform infrared spectroscopy (FTIR) spectra of sludge EPS in the three reactors during the stable period. (Here, EPS referred to the overall EPS obtained using a one-step extraction method, without layered extraction, including both LB-EPS and TB-EPS). The gray blocks were used to highlight the peaks in the figure, with the corresponding wavelengths of each peak written below the gray blocks, and the functional groups corresponding to each peak were explained in detail in the Supplementary Note 1. Synchronous spectra (c, e, g) and asynchronous spectra (d, f, h) of 2D-COS analysis using LB-EPS and SMP infrared spectra of sludge around the membrane in the three reactors, with (c) and (d) showing the AnMBR, (e) and (f) showing the eAnMBR, and (g) and (h) showing the eRAnMBR. Red and blue represent positive and negative correlations, respectively. Relevance increases with increasing color intensity. Source data are provided as a Source Data file.