Study of Isothermal, Kinetic, and Thermodynamic Parameters for Adsorption of Cadmium: An Overview of Linear and Nonlinear Approach and Error Analysis

Abstract

Reports about presence and toxicity of Cd2+ in different chemical industrial effluents prompted the researchers to explore some economical, rapid, sensitive, and accurate methods for its determination and removal from aqueous systems. In continuation of series of investigations, adsorption of Cd2+ onto the stem of Saccharum arundinaceum is proposed in the present work. Optimization of parameters affecting sorption potential of Cd2+ including pH, contact time, temperature, sorbent dose, and concentration of sorbate was carried out to determine best suited conditions for maximum removal of sorbate. To understand the nature of sorption process, linear and nonlinear forms of five sorption isotherms including Freundlich and Langmuir models were employed. Feasibility and viability of sorption process were evaluated by calculating kinetics and thermodynamics of the process, while error analysis suggested best fitted sorption model on sorption data. Thermodynamic studies demonstrated exothermic nature of reaction, while kinetic studies suggested pseudo-second order of reaction.

Sawdust-Based Cellulose Nanocrystals Incorporated with ZnO Nanoparticles as Efficient Adsorption Media in the Removal of Methylene Blue Dye

“… 51 The negative values of Δ G° indicated that the adsorption mechanism of MB onto the CNC/ZnO nanocomposite was a favorable spontaneous process. According to some studies, 52 , 53 a value of enthalpy Δ H ° < 84 kJ/mol represents physisorption while the values between 84 and 420 kJ/mol are considered to be chemisorption. Therefore, it is an indication that the interaction mechanism for the sorption of MB onto CNC/ZnO could be chemical interaction.…”

Adsorption capability of brewed tea waste in waters containing toxic lead(II), cadmium (II), nickel (II), and zinc(II) heavy metal ions

“…As a result of adsorption studies, the Langmuir isotherm was found to be the most suitable for the heavy metals according to the R 2 value. Therefore, only this isotherm model was used for the calculation of error functions (ErF) 47,48 . The results of the error functions are presented in Table 3.…”

Comparison of hydroxide‐based adsorbents of Mg(OH)2 and Ca(OH)2 for CO2 capture: utilization of response surface methodology, kinetic, and isotherm modeling

“… The parameter k ad obtained from the slope of the model plot is reported in Table 4. Since the value k ad is greater than 8 kJ⋅mol −1 56 for both adsorbents, their adsorption processes are chemical. The predicted equilibrium capacities by these models versus equilibrium pressure compare with the experimental data in Fig.…”