Deliverables Homogeneous, stable materials meeting the targeted contaminant levels The materials produced in this study, when suitable, homogeneous and stable, can, if any lots are left after the study, be used by the members of the consortium for improving/maintaining the level of their quality assurance and accreditation. Furthermore, IRMM might be interested in marketing these materials (if of sufficient quality), although the number of lots left might be insufficient for long term sales of CRM. The materials could also be used in a proficiency test or interlaboratory comparison with a limited number of participants. Method for selection and production of homogeneous material The technology successfully applied at BAM for a variety of solid environmental matrices has been optimised for the production of the materials. The final materials have been selected from a number of candidate sludges samples from state-of-the-art German sewage processing plants with biological treatment. The selection was based on the results of analysis of the target contaminants in the candidate sludges and the criterias set on the levels of the target contaminants. Technological aspects successfully tackled started with the freeze drying and subsequent sterilization of the starting material. Among several options, an irradiation procedure using a C0-60 source designed for sterilizations turned out to be most favourable, especially with regard to a future scale-up. It was shown that this method of sterilization did not deteriorate the content of those analytes potentially prone to decomposition under the applied conditions, namely the BFRs. Following the kryo-milling under cooling with liquid nitrogen of the dry sterilized material, the homogenization procedure by means of a drum-hoop-mixer avoiding the formation of agglomerates and ensuring a preset sufficiently low particle top-size had to be worked out. The bottling of the final material displaying a poor flowability made adjustments on the technical equipment inevitable. A specific feature for sewage sludge was providing the working conditions necessary to adequately process 60 kg of raw sewage sludge (70% water content, potentially contagious, stench) into a total of 500 bottles with dry, powered and homogenous ready-to-use reference material. The capabilities necessary for a future scale-up were clarified in this process. At this stage, the homogeneity, stability and test certification studies still need to be initiated. Therefore, this abstract does not cover details regarding these studies. The technological achievements will be available to a wide (scientific) audience as it is intended to publish them in reports and peer reviewed scientific journals. Results will also be made available via the project's web-site. From a commercial point of view, the technology can be interesting for partner Eurofins who is interested in the production and/or marketing of subsequently produced materials when it is anticipated that this could be a commercially sound activity. The other partners are mainly interested in application of the technology in a subsequent project (when funding is available) on the production of a certified reference material (BCR material), and in the availibility of such material for their own use. Searching for OpenAIRE data... There was an error trying to search data from OpenAIRE No results available
