A graft copolymer of κ-carrageenan and 2-acrylamidoglycolic acid (CgOH-g-AGA) was synthesized via free radical polymerization initiated by potassium peroxymonosulphate/malonic acid redox pair. For affording maximum percentage of grafting, optimum conditions were determined by varying the concentrations of κ-carrageenan, 2-acrylamidoglycolic acid, potassium peroxymonosulphate, malonic acid, hydrogen ion, time and temperature. The swelling, metal ion uptake and flocculation studies were investigated with water, three metals (Ni 2+ , Pb 2+ and Zn 2+ ) solutions, coal (coking and non-coking) suspensions, respectively. Both, polymer backbone and its corresponding graft copolymer samples were characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis.