Uranium removal from water using cellulose triacetate membranes added with activated carbon

Ultrafiltration removal of uranium from water, with composite activated carbon cellulose triacetate membranes (AC-CTA), was investigated. The filtrate was provided by uraninite dissolution with pH=6–8. Removal efficiencies were calculated measuring solutions' radioactivities. Membranes were mainly characterized by microscopy analysis, revealing iron after permeation. Uranyl removal was 35±7%. Chemical speciation indicates the presence of (UO2)2CO3(OH)3−, UO2CO3, UO2(CO3)22− and Fe2O3(s) as main compounds in the dissolution, suggesting co-adsorption of uranium and iron by the AC during filtration, as the leading rejection path. ► Cellulose triacetate (CTA) and activated carbon (AC) composite membranes were suitable for uranium removal. ► Up to 35% of uranium from low concentrated solutions was rejected by ultrafiltration. ► Rejection is performed by a hybrid mechanism regulated by AC adsorption. ► Uranium and iron speciation and predominance determines the adsorption in the membrane.