Synthesis and characterization of selective thiourea modified Hg(II) ion-imprinted cellulosic cotton fibers

• Cotton fibers were modified by insertion of ethylenediamine after periodate oxidation.
• Further modification was performed by insertion of thiourea moieties.
• The resulted chelating fibers were imprinted in presence of Hg2+ as a template and formaldehyde as a cross-linker.
• The fibers was applied to selectively remove Hg2+ from aqueous solutions.

In the present study, Hg2+ ion-imprinted chelating fibers based on thiourea modified natural cellulosic cotton fibers (Hg-C-TU) were synthesized and characterized using some instrumental techniques such as elemental analysis, scanning electron microscopy (SEM), FTIR, wide angle X-ray and XPS spectroscopy. The modified Hg-C-TU fibers were employed for selective removal of Hg2+ from aqueous solution. Effect of some essential parameters such as pH, temperature, adsorption times and adsorbate concentration were examined to evaluate the optimum adsorption condition. The adsorption kinetics followed the second-order kinetic model indicating that the chemical adsorption is the rate limiting step. Also, the adsorption isotherm experiments showed the best fit with Langmuir model with maximum adsorption capacities 110.3 and 61.8 mg/g for both Hg-C-TU and NI-C-TU, respectively.