Arsenic impact on the valorisation schemes of acidic mine waters of the Iberian Pyrite Belt: Integration of selective precipitation and spiral-wound nanofiltration processes

Arsenic and selenium presence in acid mine waters (AMWs) limits their disposal due to environmental regulations. The focus solve the economic infeasibility is directed sustainable solutions, promoting resource recovery. In fact, rare earth elements (REEs) recovery proposed most of Iberian Pyrite Belt AMWs. However, arsenic may impact REEs Among different alternatives, nanofiltration (NF) provides a concentration stage on recovery, reduces nominal flow removes hazardous species. this work, AMWs with up 10 mg/L REEs, containing (2 mg/L), were treated NF membrane. Firstly, pre-treated H2O2/NaOH, oxidise Fe(II) As(III) As(V), removal avoiding potential precipitation at Subsequently, pressure effect (6–20 bar) was studied, removing metals (>95 %), whereas rejections ranged from 60 71 %. Then, water evaluated 10, 15 22 bar by reproducing 10-stages plant. Results showed that treatment could be an alternative for (70 ?g/L 0.5 permeate concentrations, respectively) achieve mining discharge according