title: Rejected tea as a potential low-cost adsorbent for the removal of methylene blue.
abstract: The adsorption of methylene blue (MB) from aqueous solution using a low-cost adsorbent, rejected tea (RT), has been studied by batch adsorption technique. The adsorption experiments were carried out under different conditions of initial concentration (50-500 mg/L), solution pH 3-12, RT dose (0.05-1g) and temperature (30-50 degrees C). The equilibrium data were fitted to Langmuir and Freundlich isotherms and the equilibrium adsorption was best described by the Langmuir isotherm model with maximum monolayer adsorption capacities found to be 147, 154 and 156 mg/g at 30, 40 and 50 degrees C, respectively. Three kinetic models, pseudo-first-order, pseudo-second-order and intraparticle diffusion were employed to describe the adsorption mechanism. The experimental results showed that the pseudo-second-order equation is the best model that describes the adsorption behavior with the coefficient of correlation R(2)>or=0.99. The results suggested that RT has high potential to be used as effective adsorbent for MB removal.
authors.affiliation: School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia.
authors.forename: N
authors.initials: N
authors.lastname: Nasuha
authors.forename: B H
authors.initials: BH
authors.lastname: Hameed
authors.forename: Azam T Mohd
authors.initials: AT
authors.lastname: Din
mesh_terms: D000327:Adsorption; D004396:Coloring Agents / Q000737:chemistry / Q000302:isolation & purification; D004058:Diffusion; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007700:Kinetics; D008751:Methylene Blue / Q000737:chemistry / Q000302:isolation & purification*; D008855:Microscopy, Electron, Scanning / Q000379:methods; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013662:Tea; D013696:Temperature; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*; D018508:Water Purification / Q000191:economics / Q000379:methods*
chemical_list: D004396:Coloring Agents; D007220:Industrial Waste; D012996:Solutions; D013662:Tea; D014874:Water Pollutants, Chemical; D008751:Methylene Blue