ElektroPapier: Development of paper-based electrodes for microbial, electrochemical wastewater treatment

Newly developed materials and alternative
technological concepts play a central role in the sustainable use of the resource water. Innovative processes in the field of sustainable wastewater treatment are so-called microbial electrochemical technologies (MET). MET utilize electrochemically active microorganisms to treat the organic pollutant load in wastewater, while converting part of the inherent chemical energy directly into electrical energy or into chemical energy carriers. In this project, MET will be further developed towards economic installation and operation. The development of a novel paper-based material for the production of three-dimensional high surface area-to-volume ratio electrodes and the optimization of hydrocarbon-based cation-exchanger membranes (CEM) are decisive factors for increasing the performance per cost of MET.

Objective

In order to increase the performance of MET, conductive paper-based materials are to be developed and further converted into three-dimensional bioelectrodes. CAM will also be optimized for this application and tested for the first time in MET. At the same time, the costs for the use of MET for waste water treatment will be reduced, thus creating an ecological and economical solution.

In addition to flow simulations and experimental testing, innovative molecular biological methods such as flow cytometry will be used to evaluate the interactions between organic pollutants, electrochemically active microorganisms and the used materials.

Focus of work

The development of paper-based electrodes includes optimizing the graphite filler and the paper manufacturing process. The new material must possess a high conductivity, tensile strength, and its manufacture must be cost-efficient. The electrode material is to be manufactured in different geometries, which can be done by folding, for example.

To adapt the CEM, the degree of functionalization will be modified. This should improve their ionic conductive as well as provide an anti-bio fouling resistance.

Flow simulations and experimental testing will be used to check the volumetric/surface-related performance and flow behavior in the module units. Also, the interaction of microorganisms with the electrode and membrane surface is to be investigated and structure-property relationships are to be derived.

The practical function will be proven by demonstrator operation with municipal and industrial waste waters.