Adsorption of methylene blue dye wastewater by sludge based activated carbon

The activated carbon prepared by chemical activation based on sludge was use to treat methylene blue dye wastewater. The effects of grain size of activated carbon based on sludge and pH of the solution of methylene blue dye wastewater on removal rate of dye were observed. The process of adsorption was analyzed by adsorption isotherms and kinetics. The results showed that, the smaller particle size of sludge activated carbon and higher pH value of dye wastewater, the better adsorption effect gained by sludge based activated carbon on dye wastewater. When the particle size was bigger than 200 meshes, the removal efficiency and the adsorption amount were 88.2% and 136.7 mg/g, respectively. When the pH value was 11, the removal efficiency and the adsorption amount were 90.4% and 91.9 mg/g, respectively. The adsorption process can be well described by Langmuir isotherms and Pseudo-second-order rate equation was found to interpret the kinetic data suitably.