Sorption of As(III) by calix[4]arene modified XAD-4 resin: kinetic and thermodynamic approach

The present work describes the sorption behavior of a newly synthesized calix[4]arene impregnated XAD-4 resin, i.e., (IV) for the amputation of As(III) from aqueous environment. Resin IV was characterized by using FT-IR spectroscopy, scanning electron microscope, elemental and thermogravimetric analyses techniques. As(III) sorption was achieved through static method to assess the As(III) removal competency of impregnated resin IV under various conditions. Batch experiments were carried out to optimize several parameters such as effect of sorbent dosage, pH effect, contact time, initial arsenic concentration and temperature effect. From results it was observed that % sorption of As(III) is highly dependent on pH of solution. The maximum sorption was achieved at pH 4.5. Equilibrium was achieved in 45 min. From different isotherm models it has been deduced that As(III) sorption behavior of resin IV can be better explained by Langmuir with Q of 100 mmol/g and Temkin isotherm models. Furthermore, thermal study reveals that sorption process is temperature dependent. Kinetic studies found to follow second order and more appropriately Moris-Weber diffusion kinetic model. Besides this, resin IV has been utilized for the removal of arsenic from surface water samples. The field studies reveal that resin IV is an effective sorbent to treat and purify As(III) contaminated water.