What are non-biodegradable pollutants

Description:
Objective and reason for the project

The main part of z. Currently manufactured basic sensors (transducers) are based worldwide on the manufacturing process of thick film technology. Functional structures are mainly applied, dried and cured onto a planar base body (substrate) using the screen printing process. This overall system is increasingly becoming a disposal problem in view of the exponentially growing market for rapid tests. The project aims to test and optimize biodegradable substrate materials in connection with recyclable, environmentally friendly special coating materials of planar thick-layer structured basic sensors (transducers) for the quantitative amperometric or potentiometric indication of environmentally relevant pollutants.


Presentation of the work steps and the methods used The project is divided into the following work steps:
1. Testing and modification of biodegradable substrate materials
2. Development of biodegradable, low-temperature curing, screen-printable preparations
3. Development and optimization of the basic sensor layout
4. Testing of the basic sensors manufactured and optimized according to points 1 ... 3 for their biodegradability in the UFZ / UbZ in accordance with the specifications and relevant standards
5. Applicative characterization and validation of the sensors using electrochemical examination methods at SensLab Leipzig. The sensors are examined for their suitability both as an amperometric system for the direct detection of electroactive substances and as a transducer for biosensors. Hydrogen peroxide and phenols are provided as model analytes for which the sensors are modified as examples.


Results and discussion

As part of the project, all biodegradable materials that appear suitable were primarily tested as substrate material for sensor elements with a planar structure. The very good cooperative collaboration with the project group in the Leipzig Environmental Biotechnology Center enabled the latest research results to flow into the development of biodegradable materials. Furthermore, low-curable polymer thick-film pastes adapted to the substrate material have been developed which meet all the technical requirements for a sensor for rapid tests and are quite comparable to sensors which use commercial carrier materials or polymer pastes. In conclusion, it can be concluded that for the first time it is possible to dispose of the millions of used sensor elements no longer as hazardous waste, but in an environmentally friendly way as biodegradable material.
The results at the Environmental Biotechnology Center in Leipzig have shown that the rate of biological degradation (especially with the relatively thick substrate material) is not sufficient to be able to dispose of the sensor elements in normal composting operations.


Public relations and presentation

The results are published jointly in coordination with the project partners.
Since sensor elements with a thick layer structure are largely similar worldwide, the results can largely be used for the majority of these sensors. This means that millions of sensor elements would not arise as hazardous waste, but as biodegradable substances.
For companies that want to introduce this technology into their production, appropriate advice and support beyond the duration of the project is necessary.


Conclusion

The procedure for working on the project has proven itself from the current point of view.
The individual options for selecting the substrate materials and the binders for insulation and conductive layers were systematically investigated. Thanks to the very good cooperation with a project group in the Leipzig Environmental Biotechnology Center, which is working on the development of PHB materials, it was possible to use materials for the substrate that correspond to the latest research in biodegradable materials.
The composition of the insulation and conductive layers has been systematically optimized in the direction of faster biodegradation. The main goal was the development of biodegradable sensor elements that do not have to be disposed of as hazardous waste. This goal was achieved in any case. Further investigations at the Environmental Biotechnology Center in Leipzig have shown that biological degradation (mainly because of the necessary material thickness) does not reach the high speed that disposal can take place in normal composting operations.
The tests carried out by the project partner SensLab for compliance with the technical parameters showed the full functionality of the sensor prototypes compared to conventional commercial sensors.