Green Synthesis of Phytogenic Magnetic Nanoparticles and Their Applications in the Adsorptive Removal of Crystal Violet from Aqueous Solution

Anenvironment-friendly and cost-effective green recipe is employed for the production of green/phytogenic magnetic nanoparticle (PMNPs). Surfaces of PMNPs were functionalized by 3-mercaptopropionic acid (3-MPA) to investigate elimination performance of toxic dye, i.e., crystal violet (CV) from wastewater. Fabrication of functionalized PMNPs by 3-MPA (3-MPA@PMNPs) was characterized by various well-known techniques. Adsorption of CV onto 3-MPA@ PMNPs has been experimentally investigated. The developed material showed high adsorptive rate (98.57% CV removal within 120 min) and adsorptive capacity (88.65 mg/g at 25 degrees C). Moreover, various adsorption isotherm and kinetic models were applied to explore probable removal mechanism. Langmuir isotherm model successfully represented adsorption equilibrium of CV onto 3-MPA@PMNPs. Further, the adsorption kinetic data harmonized reasonably with pseudo-second-order model which revealed that the removal was mainly corroborated by the mechanisms of ion-exchange and/or chemisorption. Values of thermodynamic parameter (Delta G(o)) were - 5123.37, - 5313.46, - 6216.23, - 6764.21 and - 8548.97 KJ/mol, respectively, in the temperature range from 298.15 to 333.15 K. While the values of Delta H-o and Delta S-o were - 47.44 and - 8.67 KJ/mol, respectively. These values show that sorption was favorable, spontaneous and exothermic. The high adsorptive removal persisted at wide pH range of 6.0-12.0. The material indicated high selectivity in the presence of co-existing ions (Pd2+ and Cd2+) and offered fastest separation times from aqueous solutions due to their superparamagnetic nature. Recovered adsorbent was re-employed for > 5 times with removal efficiency of > 85%. It is concluded that 3-MPA@PMNPs can be applied as alternative sorbent for cost-effective treatment of cationic dyes from textile wastewater.