Modification of gum ghatti via grafting with acrylamide and analysis of its flocculation, adsorption, and biodegradation properties

In this work, an environmentally friendly gum ghatti-crosslinked-polyacrylamide (Gg-cl-PAAM) hydrogel was synthesized from gum ghatti (Gg) and acrylamide (AAM) using a microwave-assisted grafting technique, and tested for use in water purification applications as an adsorbent and flocculent. The Gg-cl-PAAM was characterized using SEM, FTIR, and TGA, and displayed pH responsive swelling behavior, with maximum swelling (2117%) observed in solution with neutral pH. The flocculation characteristics of Gg-cl-PAAM were tested in clay solutions as a function of pH, temperature, and the polymer mass loading, showing that the best performance is obtained at neutral pH at 40°C. The adsorption capacities of Gg-cl-PAAM for the removal different dyes such as brilliant green (BG), rhodamine B (RhB), congo red (CR), and methyl orange (MO) were tested, revealing that the adsorption of all dyes followed the Langmuir isotherm model, with qm values of 523.62mgg−1 for BG, 421.60mgg−1 for RhB, 179.09mgg−1 for CR, and 173.69mgg−1 for MO. Finally, the environmentally friendly nature of Gg-cl-PAAM was examined using the soil-burial composting method, which demonstrated 93% degradation of the Gg-cl-PAAM hydrogel within 60days. •The hydrogel of gum ghatti with acrylamide was synthesized.•The hydrogel polymer showed pH responsive swelling behavior.•The hydrogel polymer showed maximum flocculation efficiency in acidic medium.•The hydrogel degraded 93% after 60days.•Much better adsorption behavior was observed for cationic dyes as compared to anionic dyes.