This study investigates the capacity of polyamide nanofiltration membrane (SNTE NF270-2540) to extract the lanthanum (La) (III) and its mixtures with the iron (Fe) (III). A three - level factorial design and response surface methodology was used to evaluate the effects of different parameters, such as: pH (3.0 – 9.0), concentration (10 – 100 ppm), pressure (6.0 – 13.5 bars). The results showed that the retention of La (III) varied from 29 % to 100 %, depending on the experimental condition it was possible to extract all of La (III) and Fe (III) from the same mixture. The results showed that the extraction of La (III) reaches 100 % for 10 and 55 ppm at pH = 3.0 and for 100 ppm at pH = 9.0, under the pressure of 13.5 bars. At pH = 3.0, the extraction of the mixtures La (III) / Fe (III) (50 ppm / 50 ppm) and (100 ppm / 100 ppm) whatever the pressure was all (100 %). The study confirmed a high lanthanum extraction using polyamide nanofiltration membrane.
