Adsorption potential of macroporous Amberlyst-15 for Cd(II) removal from aqueous solutions

Abstract

The macroporous ion exchange resins are unique and most suitable for the adsorption of heavy metal ions due to their porous three-dimensional structures and large specific surface areas. In the current investigation, a macroporous sulphonic acid cation exchange resin Amberlyst-15 was implemented for the adsorption of Cd (II) using batch adsorption technique to evaluate its removal efficiency. The characterization of resin surface was performed by several techniques: Scanning Electron Microscopy/Energy dispersive x-ray Spectroscopy (SEM/EDS), Thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET) surface area and Point of zero charge (PZC). The effects of various experimental parameters such as time, temperature, concentration, pH and dosage amount were examined in detail. The optimum pH for maximum uptake of Cd(II) onto the Amberlyst.15 was observed at pH 3 showing the efficient working of resin under highly acidic conditions. The results also proved that Amberlyst-15 showed tremendous adsorption potential toward Cd(II) removal; 99.95% removal within 30 min reaction time and 2.01 mmol g −1 maximum adsorption capacity at 323 K. The adsorption data was well described by Langmuir adsorption isotherm and pseudo second order models. The thermodynamic parameters revealed that the adsorption was endothermic, spontaneous and feasible process with increased randomness at resin surface. The free energy of adsorption (E) (13-15 kJ mol −1 ) determined from Dubinin-Radushkevitch (D-R) model proved the ion exchange reaction mechanism for Cd(II) adsorption. The experimental results reported herein validate that Amberlyst.15 resin is a promising adsorbent for the enhanced removal of Cd(II) and other toxic metals from contaminated water and waste effluents.

Adsorption isotherms, kinetic and thermodynamic studies for cadmium and lead ions from water solutions using Amberlyst 15 resin

“…The Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm models were the most commonly utilized isotherms to explain adsorption equilibrium isotherms experimentally and mathematically. According to the Langmuir theory, every adsorption occurs on monolayer homogenous sites of adsorbent until saturated adsorption to be reached [ 1 – 3 , 41 , 44 ]. Linearized form of the Langmuir isotherm model was explained by utilizing equation (2) :…”

“…The Dubinin–Radushkevich (D - R) isotherm model was utilized to determine whether adsorption process was physical or chemical ion exchange [ 22 , 41 , 46 ]. Adsorption free energy ( E ) was obtained by using the D-R model.…”

“…The aims of this work were to perform adsorption isotherms, kinetics and thermodynamic parameters for Cd(II) and Pb(II) ions by utilizing Amberlyst 15 resin as an adsorbent [40][41][42]. Kinetics, reaction orders, adsorption capacities, contact times and thermodynamic values (ΔGº, ΔHº, ΔSº) at 298, 308 and 318 K, respectively and Ea were determined for both Cd(II) and Pb(II) ions.…”

Recovery of Ionic Liquid from the Model Solution Mixture Mimicking the Catalytically Hydrolyzed Cellulose Product Utilizing Amberlyst Ion-Exchange Resin

“…Amberlyst, a microporous resin, stands out for its high surface area and active sites, making it ideal for ion-exchange processes. Noteworthy for its chemical stability, ecofriendliness, non-toxicity, low cost, and recyclability, it has been extensively studied for various applications [33]. For instance, Amberlyst A-12 efficiently removes sulfate, showing rapid sorption and nearly complete desorption [34].…”

The effect of methanol flow rate and repeated use on amberlyst catalyst characteristics in palm fatty acid distillate (PFAD) esterification reaction

“…Amberlyst TGA curve after 3 uses Fig.-6 shows the temperature at which amberlyst undergoes decomposition, if observed the decomposition temperature of amberlyst can be divided into 3 zones. First, decomposition occurs with a decrease in mass weight <10% below 200°C which is probably the weight of the presence of water in the polymer matrix(Rabil et al 2020) or the presence of volatile compounds(Han et al 2019). Furthermore, it was seen that there was a significant decrease in mass, which was around 50% in the temperature range of 200 o C-400 o C which is probably caused by the polystyrene chain and the presence of sulfonic acid groups which are starting to depolymerize.…”