Adsorption behavior of methylene blue on polyethylene-active carbon

The adsorption kinetics of methylene blue(MB)on the sintered high density polyethylene-active carbon(PE-AC)with respect to the initial dye concentration and time is investigated.The kinetic processes of MB adsorption is described by applying Langmuir,Freundlich isotherms models and the pseudo-firstorder,pseudo-second-order and modified intra-particle diffusion models.The results show that significant increase in initial adsorption rate is observed with the increase temperature and initial MB concentration.The equilibrium adsorption is well described by the Freundlich isotherm model.The initial adsorption kinetics is more accurately represented by pseudo-first-order and the later adsorption kinetics is more accurately represented by pseudo-second-order.The calculation values of thermodynamic parameters present that the adsorption is spontaneous and endothermic in nature,and enthalpy(ΔHθ)and entropy(ΔSθ)are determined as 10.875kJ/mol and 0.0515kJ/(mol·K)respectively.