Biochar derived from sewage sludge for green technology and circular economy

The main objective of the GreenChar project is to investigate the possibilities of improving the microclimate in the regions of Trnava and Vienna in order to prevent the formation of urban heat islands and better adapt to the effects of climate change. Green roofs as part of the green infrastructure in cities improve rainwater retention and reduce the impact of urban heat islands, thus helping to mitigate the effects of climate change. The GreenChar project combines detailed analyses of the properties of biochar produced from sewage sludge as an innovative feedstock to improve the properties of roof substrates, with a focus on increasing water retention capacity, with studies of the environmental impact of the improved substrates (leaching of nutrients and metals, microbial diversity, plant stress, ...) using experimental roofs and roof lysimeters. The latter make it possible to monitor the processes in the complex substrate-water-plant system. Another focus of the project is the selection of suitable plants for extensive green roofs in the Central European urban climate with a high degree of ecosystem services and added value. As part of the project, three experimental green roofs equipped with sensors for measuring environmental data will be installed on both sides of the border at the project partners' sites. A modular green roof at the Slovakian partner and an equally unique MUGLI mobile exhibition space on both sides of the SK-AT border will be used to disseminate the results and communicate with the target group (residents and visitors to the SK-AT border regions). The project makes an important contribution to the handling and treatment of sewage sludge as a residual material and resource.