Efficient adsorption of chlorpheniramine and hexavalent chromium (Cr(VI)) from water system using agronomic waste material

Abstract

In present study, we report Cornulaca-monacantha stem (CS) and its activated carbon (CS-AC) for the removal of Cr(VI) and chlorpheniramine (CP) from aqueous system. The chemical composition and surface characteristics of samples were investigated using instrumental techniques such as Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FESEM) and energy dispersive X-ray (EDX). The surface area was determined by Brunauer-Emmett-Teller(BET) method. The BET surface area of CS-AC (288.67 m2/g) was found higher as compared to CS adsorbent (47.58 m2/g). The adsorption behavior of adsorbates was extremely dependent on the solutions pH. The maximum uptake for Cr(VI) and CP were observed at pH of 2.0 and 8.0, respectively. The equilibrium data adequately follow the Langmuir isotherm (R2 = 0.98–0.99), suggesting the monolayer sorption of adsorbate molecules. Kinetic investigations indicated that sorption behavior of Cr(VI) follow the pseudo-second-order model. While in case of CP, both pseudo-second-order and Elovich model provides the higher value of regression coefficient (R2). This revealed the chemical adsorption of adsorbate molecules. Thermodynamic study indicated the feasible, spontaneous and endothermic sorption of adsorbate molecules. The regeneration study implies that adsorbent was efficiently recovered from Cr(VI) and CP under different desorbing agents.The CS-AC adsorbent was possess 89.19% and 88.45% uptake for Cr(VI) and CP after 5th cycles of desorption-adsorption, respectively. Finally, we summarize that prepared adsorbent (CS-AC) is highly proficient, versatile and cost-effectively explored for Cr(VI) and CP decontamination from water system.