Equilibrium, Kinetic and Thermodynamic Studies of Methylene Blue Dye Adsorption from Wastewater Using Manila Tamarind Shell Copper Nanoparticles as Adsorbent

The current study’s objective is to use Manila Tamarind Shell Copper Nanoparticles (MTSCuNPs as adsorbents in a batch process to remove Methylene Blue dye from their wastewater. Contact time, solution pH, initial Methylene blue dye concentration, adsorbent dosage, and temperature were the factors that were examined in batch research. The maximum removal efficiency was predicted to be 96.37% at a temperature of 318 K, a solution pH of 7, an initial dye concentration of 10 mg.L-1, and an adsorbent dosage of 0.5 g.L-1. The Freundlich isotherm model best describes Methylene Blue removal adsorption data at 303 K, with a correlation coefficient of 0.9975, while the Temkin and Langmuir isotherms have correlation coefficients of 0.8901 and 0.8656, respectively. The kinetics study analyzed adsorption data using pseudo-first order, pseudo-second order, Elovich, and intraparticle diffusion models. Pseudo-second-order kinetics for methylene blue showed close applicability, confirming chemisorption as the rate-limiting step. The pseudo-second-order kinetics model best describes Methylene Blue removal adsorption data at 10 mg.L-1 with a correction coefficient of 0.9988, while the pseudo-first-order, Elovich model, and intra-particle diffusion model have correction coefficients of 0.9876, 0.9704, and 0.9174, respectively. The thermodynamic study found that the adsorption process is spontaneous and physisorption is dominant, with Gibbs free energy values ranging from -20 to 0 kJ.moL-1. Endothermic adsorption and an activated complex formation are associated with the process. In this study, determine the ΔH0 , ΔS0 , and ΔG0 at 303K with values of 25.766 kJ.moL-1, 114.12 J.moL-1, and -8.8003, respectively.