The potentials of biofilm reactor as recourse for the recuperation of rare earth metals/elements from wastewater: a review

Abstract

Wastewater is nowadays increasingly receiving global attention as a resource much more than a problem due to its potential so serve as a resource recovery channel. In this regard, wastewater is gradually been transformed from being a cesspool to a "treasure pool." Among notable resources in the treasure pool, rare earth metals/elements (REEs) warrant focal investigation, both in terms of environmental abundance and biorecovery, due to their environmental impacts. The ineffectiveness or cost intensiveness of extant physicochemical and advanced wastewater resource recovery techniques warrants the investigation of natural phenomenons in the treasure pools. Bacteria are able to cleverly secrete certain biochemicals to help trap and aggregate nutrients for their metabolism-the biofilms. In this regard, there is increased espousal of biofilm-enabled reactors, especially for the application of the recovery of invaluable feedstock in wastewater as well as other aqueous media due to high production rates and stability of cells. Furthermore, it anticipated that this technology will be translated to recovery of rare earth elements, due to their increased demand across the globe. This piece reiterates the nitty-gritty of biofilm-enhanced biorecovery and also keeps the scientific readership abreast of the multifarious aspects regarding the successful biofilm affected biorecovery of REEs at reactor scale.

Keywords: Bio-absorption; Biofouling; Bioleaching; Biomining; Extracellular polymeric substances (EPS); Kinetic modeling; Van der Waals bonds; Weathering.