Ecology, Environment and Conservation Paper

METHYLENE BLUE REMOVAL FROM AQUEOUS SOLUTION OF CARBONIZED ORTHOSIPHON ARISTATUS

N. Vidhyulatha and Kumaraguru

Abstract

The chemically activated carbon obtained from the stem of Orthosiphon aristatus was revealed to have an imperceptible feature of sorbent efficiency for the elimination of methylene blue from aqueous solutions of diverse concentrations. Adsorption tests were carried out in a batch procedure, and the influence of contact time, carbon dosage, and pH on percentage removal was investigated. Adsorption studies demonstrate that methylene blue uptake occurs at pH 6.7. The equilibrium adsorption data fit better with the Langmuir and Freundlich adsorption models. Kinetic modelling of the removal process was performed, and the removal process was discovered to follow a pseudo second-order model, the Elovich model, and the intraparticle diffusion model. The rate constant for the adsorption process was estimated. The thermodynamic parameters change in free energy (G°), enthalpy (H°), and entropy (S°) were calculated, and negative values of (G°) suggested that the removal process was spontaneous at all temperatures. It was concluded that activated carbon derived from the stem of Orthosiphon aristatus has a high capacity for methylene blue elimination.