Methylene blue adsorption on factory-rejected tea activated carbon prepared by conjunction of hydrothermal carbonization and sodium hydroxide activation processes

Soybean hulls as a low‐cost biosorbent for removal of methylene blue contaminant

“…Hence, it is possible to propose that one of the main mechanisms of MB adsorption is a consequence of electrostatic interactions. Similar behavior was verified by Akkaya and Güzel, Franca et al, and Islam et al, whose work proved that at pH > pH PCZ the MB removal was maximal and did not alter significantly. As no significant differences in adsorption were observed with pH variation, in the later studies the natural pH of the MB solution (approximately 6.3) was used.…”

Malachite green removal using modified sphagnum peat moss as a low-cost biosorbent: Kinetic, equilibrium and thermodynamic studies

“…Further, a spread in adsorption sites may have been responsible for a wide spread in kinetics constants, eventually leading to pseudo-second order-like behavior [38]. This observation indicates that the adsorption rate is more reliant on the accessibility of the adsorption sites rather than the concentration of the dye in the solution, suggesting a chemisorption process [39,40]. Similar result has been reported for adsorption of basic blue 69 (a cationic dye) on the surface of peat moss [41].…”

“…This behavior suggests that two or more steps affect the adsorption process. The deviation of plots can be due to differences in mass transfer during the initial and final stages of the adsorption [39]. In addition, decreasing the slope from the step 1 to step 2 at each initial MG concentration indicates that the Intra-particle diffusion of MG molecules to the pores was the rate-limiting step in the adsorption process on the SPM [36].…”

Production and characterization of activated carbon from wood wastes

“…This parameter is one of the most important to take into account for activated carbons. It is widely known that in a greater surface area, there are more available active sites, which allows the material to be promising for using in adsorption processes [15].…”