Abstract: A composition includes a polymer-grafted lignin formed by grafting one or more hydrophilic polyalkylene oxide polymers with lignin, wherein the average grafting density of the polymer-grafted lignin is less than 10 per lignin particle and the weight fraction of the one or more hydrophilic polyalkylene oxide polymers in the polymer grafted lignin is less than 40%.

Abstract: The disclosure relates to the design and synthesis of selected ligands, dendrimers, polymers and other solid phase substrates for selective chelation of rare earth elements (i.e. lanthanides), and use of those selective ligands for synthesis of resins, polymers and other types of solid supports for separation and recovery of lanthanides from aqueous media. Recovery of critical elements from aqueous media occurs in a simple two-step process: pre-concentration of REE on the adsorbent and recovery by acid elution. The present invention can be used for design of selective ligands immobilized on solid substrates for extraction of various constituents, such as lanthanides, actinides, radionuclides, trace metals, etc., from aqueous media.