Adsorption kinetics and thermodynamics and equilibrium of ibuprofen from aqueous solutions by activated carbon prepared from Lemna minor

In this study, the adsorption of Ibuprofen (IPF) antibiotics from aqueous solutions by Lemna minor activated carbon (LMAC) was studied in a batch adsorption system. LMAC exhibited a large surface area of 1,164.5 m2/g, the total pore volume of 0.417 cm3/g, yield of 0.482, and pHpzc of LMAC were 6.6. In addition, adsorption was endothermic and spontaneous and was highly pH-dependant, the optimum pH was 3. The equilibrium data obtained were analyzed by Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherm models. The equilibrium time was found to be 75 min. The Langmuir model gave the best correlation with the experimental data. Maximum adsorption capacities of IPF were 124.5, 141.8, 159.2, and 181.2 mg/g at 283, 298, 313, and 328 K, respectively, and their adsorption mechanism was the monolayer adsorption on the surface of LMAC. The adsorption was found to follow the pseudo-second-order kinetics. Both film diffusion and intra-particle diffusion were found to be the major process facilitated the adsorption. The optimum conditions for IPF adsorption were at IPF concentration of 25 mg/L, pH of 3, LMAC dose of 1.2 g/L, the contact time of 75 min, and temperature 328 K. The best efficiency for the removal of IPF was obtained 99.98%.