New system approach in wastewater treatment with a microbial fuel cell (MFC), which generates electricity directly from wastewater with the help of microorganisms and thereby disintegrates substances contained in the water.
In the joint project "BioBZ", a novel system approach was pursued in order to enable the energy transition in wastewater treatment. The core of the developed system is a microbial fuel cell (MFC), which uses microorganisms to generate electricity directly from wastewater and breaks down organic substances in the process. This reduces the energy consumption and increases the efficiency of power generation, but also of cleaning. As part of the development of the MFC from the laboratory to the semi-industrial scale (scale-up factor approx. 1,500), several component and material developments were also carried out:
- Composite flat electrode made of electrically conductive polymer and graphite as anode for growth of electroactive microorganisms
- Catalyst mixture for optimized oxygen reduction at the cathode
- Concept and components for self-consumption-minimised control of the power yield
- Prototype for storing and using the microbially generated electricity.
However, some further developments are necessary for the applicability of the method in practice. These essentially relate to the following requirements and have already been partially solved in the follow-up project Demo-BioBZ (www.demo-biobz.de).
a) Non-clogging, low-maintenance continuous operation
b) Avoiding the drop in performance due to biofouling, scaling, catalyst poisoning
c) Protection of the electroactive biofilm
d) Treatment of larger quantities of waste water
e) Full stand-alone operation with TRL9
The intent of the follow-up project is to build a demonstration-unit with a capacity of 200-250 EW on the wastewater treatment plant of Goslar.
