The present experiment explains the effectiveness of adsorption studies of methylene blue dye from aqueous solutions on activated carbon from Selenicereus grandiflorus (SG) treated with conc. sulfuric acid. The sulphuric acid-treated Selenicereus grandiflorus activated carbon (SGAC) was used as low-cost adsorbent for the removal of methylene blue dye from aqueous solution. It suggests an ideal alternative method to adsorption of dye compared to other expensive treatment options. The adsorption studies have been conducted at different experimental parameters, i.e., pH, contact time, adsorbent dose and initial dye concentration. The batch mode experiments were conducted by different adsorbent dose (0.03-0.150 g per 50 mL), pH of the solution (2-12), effect of time (3-18 min), initial dye concentration (10 mg/L), point of zero charge and regeneration of spent adsorbent studies. Langmuir model shows better fit to the equilibrium data (R2 = 0.966) than Freundlich model. The adsorption capacity (Qm) of SGAC increases with increasing dosage where Qm is 16.17 mg g-1.
