A method for the automated construction of stable electrocatalytic bacterial biofilms

Abstract

The invention relates to a method for automatically constructing a stable electrocatalytic bacterial biofilm. The method comprises the following steps: firstly assembling a microbe electrochemical reactor, and connecting circuits, wherein the first circuit is as follows: a fixed resistor is connected between an anode and a cathode in series, and the second circuit is as follows: an adjustable direct-current power supply, an ampere meter and a work contact of a circulating time relay are connected between the cathode and the anode; then injecting a bacteria growth medium solution into an anode chamber, inoculating a bacteria source, prestarting a microbe anode by switching on the first circuit, then controlling pulse current between the anode and the cathode to be gradually increased at preset velocity according to the potential change of the anode by switching on the adjustable direct-current power supply of the second circuit, wherein the pulse current is immediately lowered by 40%-60% when the potential of the anode is increased to a limit value and enters a new round of growth stimulation, and the electrocatalytic bacterial biofilm is completely constructed till the pulse current value reaches a preset current limit value and is stable at the preset current limit value for more than 10 hours. The electrocatalytic bacterial biofilm disclosed by the invention can be stably operated with the relatively high working current.

Description

technical field [0001] The invention relates to a method for automatically constructing a stable electrocatalytic bacterial biofilm, which belongs to the technical field of microbial electrochemical reactors. Background technique [0002] Microbial electrochemical reactors include microbial fuel cells, microbial electrolysis cells, and microbial electrochemical sensors. In microbial electrochemical reactors, the electrocatalytic activity and operational stability of the electrocatalytic bacterial biofilm attached to the electrode surface are the key components that determine the performance of the reactor. A stable and efficient electrocatalytic bacterial biofilm can improve the performance of microbial fuel cells and microorganisms. Energy efficiency of electrolytic cells, increased sensitivity of microbial electrochemical sensor signal responses. Electrocatalytic bacterial biofilm is a cell accumulation layer with a certain spatial structure formed by the cells and extrac...

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Problems solved by technology

[0006] The electrocatalytic bacterial biofilm constructed by the potential adaptation method generally has the following shortcomings: (1) the limit working current that the electrode can reach is small, and the electrocatalytic efficiency is low; Poor endurance, when the working current passing through the electrode approaches or exceeds its limit current, the electrode will be rapidly over-polarized, and over-polarization will cause the anode potential to move positively to +1.2V in a short period of time (usually no more than 10 minutes) (compared to the standard hydrogen electrode), such a high anode potential will cause irreversible damage to the bacteria themselves, resulting in the destruction of the electrocatalytic bacterial biofilm and the loss of catalytic function

In short, the electrocatalytic bacterial biofilm constructed by the potential adaptation method generally has the disadvantages of low catalytic activity and poor adaptability to high working current. Unable to work continuously and stably at an operating current close to its limiting current level

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