Adsorptive removal of methylene blue from aqueous solution using activated carbon from AnthacephalousCadamba leaf powder: Equilibrium, Kinetic and Thermodynamic StudiesAuthor(s): K.Bhagya Lakshmi, P.Kalpana
The uncontrolled discharge of dyes into the natural water bodies is a global environmental concern due to their toxic effects. Increasing environmental awareness is forcing waste creators to consider newoptions such as adsorption for the disposal of colored wastewaters. Due to prohibitive costs of commercially available activated carbon, low-cost adsorbents with high adsorption capacities have gained increasing attention. The present investigation deals with adsorption of methylene blue on AnthacephalousCadamba leaf powder as activated carbon. The batch technique was adopted to know the influence of process parameter such as contact time, solution pH, initial dye concentration, dosage, temperature on biosorption capacity.Adsorption data were modeled using the Freundlich, Langmuir, Tempkin and pseudo first order and pseudo second order kinetic equations. The experimental data fitted well with pseudo second order kinetic model. Thermodynamic parameters like free energy (ÄG), enthalpy (ÄH) and entropy (ÄS) of the systemswere calculated. It was found that the adsorption process was feasible, exothermic and spontaneous.