An Overview of Rare Earth Elements in Sewage Sludges and Their Ashes

摘要

In this work, data about REY concentrations in sewage sludges and their ashes have been analysed. The source of REY in them is mainly geogenic, which is why sludges from regions like China and Brazil have higher concentrations. Thus, the combustion or co-combustion of sewage sludge as a way of recovery its energy potential and, secondarily, the processing of their ashes in order to obtain REY may be interesting, in certain regions, depending on the techno-economic and environmental context of the moment.