Abstract: Increased usage of heavy metals for industrial activities has resulted in an increased concentration of these metals in waste water. Presence of heavy metals in wastewater is of great interest because of their known toxic effects on the nearby environment. In this study, the removal of cadmium (II) ions from an aqueous solution using Methylglycinediacetic acid (MGDA) modified pericarp of Gossypium herbaceum L. as a green adsorbent, in batch condition was investigated. The equilibrium studies were systematically carried out in a batch process which covered a various process parameter inclusive of pH, contact time, temperature, adsorbent dose, agitation rate and initial ion concentration. The adsorption equilibrium data were adequately characterized by Langmuir, Freundlich, Temkin and DKR isotherm models. Best fitting isotherm models were in the following order, Langmuir (R2 = 0.9996) > Freundlich (R2 = 0.9974) > Temkin (R2 = 0.9637) > DKR (R2 = 0.899). The adsorption kinetics was found to follow pseudo-second-order rate kinetic model. Thermodynamic study confirmed that the biosorption process was endothermic, spontaneous and proceeded with increased randomness. All results showed that the MGDA modified pericarp of Gossypium herbaceum L. is an alternative low-cost green adsorbent for removal of cadmium (II) ions from an aqueous solution.

Keywords: Methylglycinediacetic acid, Gossypium herbaceum L., cadmium (II), isotherm\

| DOI: 10.17148/IARJSET.2021.8909