Separation of praseodymium(III) from aqueous solutions by nanofiltration

The increased demand for rare earth elements in commercial products is increasing their production, which in turn increases public exposure to rare earth elements. The objective of the present work is to study the separation of praseodymium from aqueous solutions by a commercial nanofiltration membrane (NF-300) at various operating conditions. The permeate and feed samples were analysed with inductively coupled plasma atomic emission spectrometry (ICPAES) to find praseodymium [Pr(III)] concentration. The results indicated that the separation of Pr(III) ions increased with increase in applied pressure (2-10 bar) and cross flowrate (4-16 L min(-1)); and decreased with increase in feed concentration (10 mg L-1 PrCl3 - 100 mg L-1 PrCl3). The highest observed separation of the Pr(III) was found to be 89.07 and 84.20% for an initial feed concentration of 10 and 100 mg L-1 PrCl3 respectively. It was also observed that separation of Pr(III) increases to 99.28 and 99.30% in complexation step by using ethylene diamine tetra aceticacid (EDTA) and diethylene triamine penta aceticacid (DTPA) respectively, as the chelating agent has generally influenced by pH (2 - 10).