Removal of methylene blue by tea wastages from the synthesis waste waters

The tea wastages could remove methylene blue (MB) as a cationic dye from waste water corresponding to second-order kinetic model. Thermodynamic studies showed that adsorption equilibrium constant (KL) and maximum adsorption capacities (Qmax) were increased with increasing temperature. The removal efficiency of MB for Co 0.01 mmol/L at optimum conditions was about 85%. The maximum uptake capacity (Qmax) of methylene blue in a batch reactor was 0.328, 0.542 and 0.659 mmol/g at 15, 25 and 40 °C, respectively. The enthalpy change (ΔH) and entropy change (ΔS) were 11.356 kJ/mol and 20.563 J/(mol K), respectively.