Development of Electron Beam Systems and Technologies

In the joint project "ARA", Fraunhofer FEP and CREAVAC GmbH demonstrated the degradation of pharmaceutical pollutions through combined wastewater treatment with low-energy electrons and ozone for improved biodegradability.

Due to their increased use in medicine and inadequate degradation in conventional wastewater treatment plants, ever higher concentrations of hormones, antibiotics and X-ray contrast agents can be detected in the environment and thus also find their way into the food chain and drinking water. 

The harmful effects of these micropollutants on the human organism are the subject of current research. The mechanisms of action are not yet fully understood, but there are serious indications that point, for example, to a reduction in fertility, an increase in certain cancers and the emergence of antibiotic resistance. 

In the "ARA" research project funded by the Saxon State Ministry of Economic Affairs, Labor and Transport, the joint partners Fraunhofer FEP and CREAVAC GmbH therefore set themselves the goal of developing a new type of treatment process that significantly improves the degradation of persistent micropollutants.

For this purpose, the laboratory prototype of a hybrid treatment module was developed, tested and optimized, which combines the irradiation of a thin liquid stream by low-energy electrons with ozone treatment. 

The hybrid treatment module was designed to be so compact, that (after appropriate upscaling) it will enable the local pre-treatment of wastewater from so-called point emitters (such as hospitals and pharmaceutical companies) in an economical and energy-efficient manner in the future.

This aims at an effective, broadband transformation or splitting of the micropollutants in order to make them more degradable for downstream biological treatment stages of conventional wastewater treatment plants. 

The module was integrated into the FEP test plant REAMODE. In this laboratory setup, partial building blocks of the new treatment concept were first examined separately and then optimized as a system. This included the functionality of all components and their control, the generation of ozone and its injection into the liquid to be treated, the shaping of the fluid flow as well as the homogenization and dosimetric quantification of the energy input into the liquid irradiated with low-energy electrons.

The superior treatment success compared to known methods (such as activated carbon filtration or UV irradiation) was demonstrated using selected test substances. These were treated in synthetic test wastewater and then subjected to analysis by High-performance liquid chromatography and a simulation of the biodegradability of the transformation products in a laboratory wastewater purification unit with activated sludge from a municipal wastewater facility. Following the successful completion of the project, an upscaling of the concept and expansion of its field of application is now envisaged, e.g., to the purification of wastewater from the chemical industry or agriculture, where the simultaneous inactivation of pathogens is of additional value and expected.