The biochars prepared from cinnamon and cannabis as nature-friendly adsorbents for removal of Cd(II) ions from aqueous solutions

Cinnamon and cannabis were utilized to produce biochars, which operate as promising adsorbents by pyrolysis in various temperatures using the N-2 atmosphere. The novel biochars were analyzed via scanning electron microscopy, X-ray powder diffraction, Fourier-transform infrared spectroscopy, the pH point of zero charges, and N-2 adsorption-desorption isotherm styles, followed by testing the adsorption attributes of these materials using Cd(II) ions in a water bath. The Cd(II) adsorption onto biochars was satisfied in the neutral pH of 7.0 and a temperature of 65 degrees C. The equilibrium data in aqueous solutions were fitted to Langmuir (L), Freundlich (F), Tempkin ( T), and Redlich-Peterson (R-P) models. Kinetic adsorption data were analyzed using the pseudo-first-order (PFO), pseudo-second order (PSO), Elovich (E), and intraparticle diffusion (ID) models. In addition, the Cd( II) adsorption performance was proficiently narrated through Langmuir and pseudo-second-order models and electrostatic force and chemical reaction were originally responsible for adsorption mechanism. Further, the results demonstrated that the obtained q(max) from biochars at the pyrolysis temperature of 600 degrees C was higher than that noticed at pyrolysis temperatures of 300 and 400 degrees C. Finally, the adsorbent dose of 0.1 g and temperature of 65 degrees C, as well as supplying q(max) of 147.05, 153.84, 158.73, 133.33, 144.92, and 175.43 mg g(-1) were observed for cinnamon 300, cinnamon 400, cinnamon 600, cannabis 300, cannabis 400, and cannabis 600, respectively.