Synthesis and characterization of acrylic acid grafted gum tragacanth and its effect in Fe2+ removal

In this paper, grafting of acrylic acid monomer on Gum tragacanth was performed. Variable of experiment included concentration of initiators and monomer, time, and temperature. Grafting efficiency was measured in the term of percentage of grafting (%G) and percentage of grafting efficiency (%E). Effectiveness of grafted gum in ferrous ion removal at different condition was assessed. According to this study, grafting was influenced by different concentration of initiators. The best result obtained at 5 × 10-3 mol/dm-3 [Fe2+], 1.35 × 10-3 mol/dm3 [H+], 4 × 10-3 mol/dm3 potassium monopersulfate and monomer concentration = 5 × 10-2 mol/dm3. Amount of added gum was restricted to 0.25 g, addition of more gum resulted to abrupt decrease of both parameters. Time and temperature affected grafting reaction and the best condition for grafting was 25 ºC, 90 min. Finally, the ability of resultant grafted gum for removal of ferrous ion from aqueous media was assessed. The maximum removal of ferrous ion took place at pH = 6, grafted gum = 150 mg and contact time 60 min.