Synthesis of a novel flocculant on the basis of crosslinked Konjac glucomannan-graft-polyacrylamide-co-sodium xanthate and its application in removal of Cu2+ ion

A novel functionalized polymeric flocculant on the basis of Konjac-graft-poly (acrylamide)-co-sodium xanthate was synthesized via copolymerization reaction of crosslinked Konjac glucomannan, acrylamide (AM), and sodium xanthate using epichlorohydrin (ECH) as cross-linker and ceric ammonium nitrate (CAN) as initiator in aqueous solution. The optimal synthesis conditions were as follows: KGM = 3 g, [ECH] = 4.9 × 10−3 mol/L at 35 °C for 2 h, then [CAN] = 4.0 × 10−3 mol/L, and the weight ratio of KGM and AM was 1:3 at 45 °C for 2.5 h, and then [NaOH] = 0.1 mol/L, [CS2] = 59 × 10−3 mol/L at 30 °C for 2 h. The copolymer was characterized by FTIR, DSC and Elemental analysis. Flocculation test shows that in some extent, the cations, pH value, and turbidity are favorable for the removal of Cu2+ ions, but an excess dosage lead to an unobvious effect, and some anions express a negative effect on the Cu2+ removal. There exists the cooperation between Cu2+ ions and turbidity in the removal performance.