Abstract
Background: Water pollution due to rapid industrialization becomes a critical issue. Presence of industrial dye in water is a major concern for scientific community.
Objective: The objective of the study was to synthesise acrylamide graft copolymers of Azadirachita indica (neem) gum and characterized the prepared hydrogel as a flocculating agent and ineffective removal of cationic dye methylene blue from aqueous solution.
Methods: Various batches of acrylamide graft copolymers were synthesized using microwave irradiation and evaluated for their potential to reduce turbidity when added in 1%w/v solution of kaoline (artificial wastewater). Application of graft copolymers in the removal of methylene blue from aqueous solution was also evaluated.
Results: Batch N7 prepared using 0.5%w/v solution of ceric ammonium nitrate and 10 times microwave exposure showed lowest shelf caused turbidity at the concentration level of 0.2%w/v. N7 also showed a significant reduction in the turbidity when added in 1%w/v solution of kaoline. At the dose level of 0.4g/l, N7 showed the maximum removal of methylene blue i.e. 93.04 (±3.3%). Adsorption isotherm studies carried out at 25±2°C and pH 7 showed best fit to the Langmuir isotherm model with a regression coefficient of 0.962. Adsorption of methylene blue from aqueous solution followed Pseudo second-order kinetics model with regression coefficient 0.991. Intraparticle diffusion model easily predicts that intraparticle diffusion was not rated limiting step for adsorption of methylene blue.
Conclusion: From the study, it can be concluded that acrylamide grafted neem gum polysaccharide can be effectively used for the treatment of wastewater.
Keywords: Acrylamide graft copolymers, adsorption, Azadirachita indica gum, cationic dye, flocculating agent, methylene blue.
Graphical Abstract
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