Removal of molybdate and vanadate ions by a copolymer adsorbent in aultrafiltration system

Abstract

In this investigation, the removal of Mo and V oxyanions was carried out using the polymerassisted ultrafiltration technique (PAUF) with a poly(acrylamide-co-diallyldimethylammonium chloride) (P(AAm-DDACl)). As a result, 100% of Mo and 80% of V were removed at pH values of 9, with a polymer:metal molar ratio of 10:1 and an optimum metal concentration of 60 mg/L. The presence of competitive ions such as phosphate, sulfate, and chloride affected the retention of Mo, decreasing its retention to 60% in all cases. For V, all competitive ions behaved in a similar way, producing approximately 50% of metal removal. The permeate flux was kept almost constant for all solutions (40 to 80 L/hm2), which indicates that the optimal retention conditions are stable over time. In addition, the characterization of P(AAm-DDACl) was carried out by infrared spectroscopy analysis (FT-IR), and the morphology of the membrane before and after use was analyzed by scanning electron microscopy (SEM) showing significant changes in its morphology. The energy dispersive X-ray spectroscopy (EDS) analysis indicates the presence of Mo and P(AAm-DDACl) in the membrane after use. Rivas BL (main) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 Keywords: Polymer; Membrane, Ultrafiltration; Vanadium; Molybdenum.