Microwave assisted preparation of glycidyl methacrylate grafted cellulose adsorbent for the effective adsorption of mercury from a coal fly ash sample

• Glycidyl methacrylate grafted cellulose was prepared using microwave radiation.
• Characterization of the adsorbent was studied in detail.
• The sorbent has an adsorption capacity of 37.03 mg g−1 for mercury.
• Adsorbent is effectively regenerated with potassium iodide.
• Adsorbent applied to remove mercury from a fly ash sample.

Biopolymer materials are known for their excellent attributes in diverse applications. In this work, we present a novel microwave assisted preparation of glycidyl methacrylate (GlyMA) grafted cellulose adsorbent for the effective adsorption of mercury. The graft polymerization of glycidyl methacrylate onto cellulose in polar aprotic solvent dimethylformamide (DMF) medium was investigated comprehensively for the removal of mercury. The grafting was confirmed through various characterization techniques such as FT-IR, powder XRD, SEM and EDS analysis. The adsorption was effective at pH 5.0 in 1.0 M NaCl medium with 25 mL of 50 mg L−1 Hg(II) solution and a Langmuir adsorption capacity of 37.03 mg g−1 could be attained. The electrostatic interaction between the tetrachloromercurate(II) anion and the protonated oxygen atoms in the monomer GlyMA is the plausible mechanism. The adsorption process is spontaneous and endothermic with a positive entropy change and the pseudo second order kinetics favours the interaction. Effective desorption of mercury is achieved using KI thereby regenerating the adsorbent material. The utility of the adsorbent is recognized in its application towards the adsorption of mercury from a coal fly ash sample.

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