Recovering metals from sewage sludge and similar substances by hyperaccumulator plants.
The enrichment of metals from diffusely distributed concentrations (e.g. sewage and sewage sludges), is possible using currently available technology systems only with great expenditure of energy. This exploratory project investigates the usability of the adaptation strategy of plants that hyperaccumulate metals in their tissue. Different analysis should demonstrate which plants under which conditions provide antimony, chromium, cobalt, manganese, nickel, zinc and rare earths particularly for good accumulations of sludge. In addition lead, cadmium, copper and mercury are analysed because they represent limit values for heavy metal concentrations in sewage sludge.
The aim is to identify the best-fit plants for antimony, chromium, cobalt, manganese, nickel, zinc and rare earths, as well as identify appropriate substrate properties. In addition, suitable sites for Austria should be elicited where these metals are incurred in economically interesting quantities in effluent streams and stakeholders from the beginning to the end of the process chain (waste management, industrial) to be addressed in order to involve them in the development of appropriate work-up strategies.
The results of this project should provide a substantial foundation for next steps and identify open research questions:
- Recovery of valuable resources from sewage sludge or ash or metal-rich industrial wastewater (e.g. sewage metal producing farms), on an energy and environmentally friendly way
- Simultaneously detoxification of the starting materials of heavy metals and thus opening the possibility to ring thus back to the biological cycle (e.g. as a fertilizer in agriculture)
Technical office for chemical engineering, DI Monika Iordanopoulos-Kisser
completed in April 2014