Das Projekt "Entwicklung eines einfach zu verarbeitenden Elektrolyten zur Dekontamination durch anodisches Polieren" wird vom Umweltbundesamt gefördert und von Kraftanlagen AG Heidelberg durchgeführt. Objective: electro polishing has become an approved and suitable decontamination process achieving high decontamination factors. However, the spent electrolyte is hard to process and convert into a waste form suitable for disposal. For example, in order to solidify phosphoric acid at a concentration above 60 per cent in cement, it must be neutralised and heavily diluted. As a result, the waste volume for disposal is much higher than the initial electrolyte volume. The aim and objective of this research is to find an easy-to-process electrolyte with high decontamination factors, suitable for disposal, which would give a much wider range of application to electro polishing as a decontamination process. This means that is should be possible to condition the spent electrolyte in simple process steps, such as filtration, sedimentation and thermal decomposition, to produce a waste form that is easy to fix in cement. The specified requirements with a view to easy processing of the electrolyte are fulfilled by a number of organic acids. In 1983, the contractor carried out various tests and experiments on organic acids. Whereas decontamination factors were satisfactory, unsatisfactory results were obtained for the electro polishing time, the service life and thermal stability of the electrolyte, current density etc. These process parameters must be optimised. This work will be carried out in collaboration with team, Italy. General information: 1. Literature survey for identification of the available information on already existing experience. 2. Selection of electrolytes other than phosphoric acid, promising easier conditioning and waste disposal. 3. Test series on contaminated and non-contaminated samples in order to optimise the electrolytes with regard to decontamination efficiency (effect of chemical additives, of modifying process parameters...). 4. Optimisation of the process to minimise the final waste volume. 5. Development of procedures to extend the lifetime of electrolytes, in particular by continuous filtration. 6. Processing of selected electrolytes (sediment elimination, salt precipitation, solidification of sludges, volume reduction of the residual liquid, solidification of electrolyte residues). 7. Investigations about 'on-the-job-safety': chemical aggressiveness, formation of toxic products, explosion hazards, etc.