Chapter 6 - Anthropogenic rare earth elements in aquatic environments: Occurrence, behaviour, and fate

Abstract

Recent years have witnessed a rapid global increase in the production and application of high-technology industrial and consumer products based on rare earth elements (REEs). High-technology REEs comprise of 17 elements, 15 lanthanides, and yttrium and scandium. The increased use of REEs in high-technology applications has led to a corresponding increase in their release and occurrence in the environment including aquatic systems. Barring a few exceptions, comprehensive reviews on the detection, fate, and biogeochemical behaviour of REEs in aquatic systems are still limited. The present chapter analysed and synthesized the current evidence on REEs in various aquatic systems. A summary of the nature, properties, and high-technology applications of rare earth elements in industrial and consumer products is presented. To date, evidence shows that high-technology rare earth elements (REEs) have been detected in various aquatic environments including industrial and municipal wastewaters, surface water, groundwater, and drinking water sources. The hotspot sources and migration processes of REEs from their sources to the various aquatic environment receptors are presented. The biogeochemical behaviour and fate of REEs in aquatic systems as well as the biogeochemical factors controlling such behaviour are discussed. Lastly, future directions including knowledge gaps on REEs in aquatic systems are presented.