Vanadium removal from water assisted by FeCl3 using low pressure membranes

Abstract

Vanadium (V), released from both natural and anthropogenic sources, occurs in groundwater and surface waters at 0.2-100 mu g L-1 (freshwater) and 0.2-29 mu g L-1 (seawater). This work evaluates V removal with low-pressure membranes (MV020 and UP150) enhanced with FeCl3. The effects of Fe/V molar ratio, transmembrane pressures (TMPs), and membrane type on removal efficiency and flux performance were examined. In a 60-min operational period, V rejection at Fe/V = 0 remained below 61.8% (UP150) and 24.5% (MV020). Raising the ratio at Fe/V = 1 increased removal to 73.9% (UP150) and 53.3% (MV020); at Fe/V = 3 the values rose to 88.3% and 60.2%, respectively. In 6-h operational period with UP150 at Fe/V = 3, peak removal reached 95.1%, but progressive fouling caused flux decline; after backwashing cycles the flux partially recovered while removal stabilised around 86%. SEM-EDS and FTIR analyses confirmed Fe-V interactions on membrane surfaces. Overall, FeCl3-assisted low-pressure UF offers high V rejection with moderate chemical demand, making it a compact and energy-efficient option for decentralised water treatment.