Method and device for controlling the activity of a bioelectrochemical system comprising both a bioanode and a biocathode

A method for regulating the activity of an electrochemical device said device having an anode and a cathode that are submerged in an electrolyte placed in an anodic compartment and a cathodic compartment, respectively, these compartments being separated by at least one membrane or connected to each other by a salt bridge, the device optionally including a reference electrode,

• said method comprising the steps of:
• applying a potential difference between the anode and the cathode, or between the anode and the reference electrode;
• wherein the electrolyte of the anodic compartment, and the electrolyte of the cathodic compartment contain microorganisms in suspension or in the form of one or more biofilms, the electrodes thus being called the bioanode and biocathode, respectively, and in that the operation of the device is controlled via a dual regulation including the further steps of:
• a first regulation called the priority regulation, of the potential difference between the bioanode and the biocathode or between the bioanode and the reference electrode, between a minimal limit value allowing an electroactive biofilm to develop on the bioanode and a maximum limit value that is lower than the oxidation potential of said biofilm;
• and
• once the first regulation has been implemented, a second regulation, called the subsidiary regulation, that optimizes the faradaic efficiency of the biocathode;
• and
• wherein, while maintaining the first regulation of potential difference controlling the biological activity at the bioanode, the second regulation controls the optimization of the current density at the biocathode with a view to producing particular chemical species at the biocathode.