Effective Removal of Heavy Metal Ions Using Glycerol and Starch Xanthate

Abstract

Glycerol and insoluble starch xanthates were synthesised and effectively used in the removal of Pb, Cd and Cu from aqueous solutions. The insoluble metal complex formed between the sulphur atoms in the xanthates and the heavy metals were easily separated. Lower dosage of glycerol xanthate was required in each case, with the optimum molar ratio (M 2+ /GX) of 2. Moreover, the use of glycerol xanthate required no pH adjustments to give a 100 % heavy metal removal within the range of the detection limit. As for the ISX, there was a remarkable metal scavenging activity when the ISX contained high amount of Sulphur per molecule (10.12% S) and when the pH was adjusted to 6. Butyl xanthate was also synthesised to make a good comparison with the glycerol and insoluble starch xanthate. The xanthates from these two sustainable materials (Starch and glycerol) are proven to be more effective in metal scavenging activity. FTIR and CHNS elemental analyses were used to prove the evidence of xanthation, in addition, 13 C NMR was used to characterise the glycerol xanthate.