Experimental and economic evaluation of nanofiltration as a pre-treatment for added-value elements recovery from seawater desalination brines

Desalination brine mining emerges as a solution to supply raw materials the European Union industry in circular economy approach since valuable minerals and metals (e.g., B(III), Mg(II), Ca(II), Sc(III), V(V), In(III), Ga(III), Li(I), Mo(VI), Rb(I)) are present seawater but low concentrations. Brine pre-treatment is important remove species that may impair performance of other technologies involved increase recovery efficiencies. Hence, nanofiltration calcium precipitation were proposed stages. Nanofiltration was studied separate monovalent from multivalent elements (Fonsalía desalination plant case study), while economically, it evaluated whether would be better place before (Scenario 1) or after 2) Ca(II) stage, considering can produce scaling membranes. Three commercial membranes tested using synthetic brines at 30 bar. Experiments (65 % permeate recovery) showed Fortilife XC-N PRO-XS2 presented higher Mg(II) rejection than NF270. Heating for jeopardizes economic feasibility project. Scenario 1 best configuration lower total levelized cost (?1.6 €/m3 inlet, without heating removal). In such scenario, reported selectivity between elements.