1. Scanning electron microscopy (model name-XL30, Philips) was used to examine the structural changes in the tested membranes and anode surfaces.

2. Chemical oxygen demand (COD) was determined using the potassium dichromate oxidation method (COD MR test vials, Camlab, UK) and results were recorded manually.

3. For the volume resistivity of the tested anode material, a 4-wire resistance measurement was carried out with a digital multimeter (M-3850D, METEX, Korea) and bench power supply (PSM-3004, GW INSTEK, Taiwan). Results were recorded manually.
 
4. Power output of the MFCs was monitored continuously in real time in volts (V) using an ADC-24 Channel Data Logger (Pico Technology Ltd., UK). Data was saved in PLW file. Weekly polarisation measurements were carried out using an automated computer-controlled variable resistor system.

5. Details of data collection and process can be found in the manuscript.