equilibrium and kinetic studies of cu (ii) biosorption onto waste tea and coffee powder (wtcp)

Biosorption of cu(ii) ions from aqueous solutions onto waste tea and coffee powder (wtcp) has been investigated in a batch biosorption process. the biosorption process was found to be dependent on ph of solution, initial metal ion concentration, biosorbent dose, and contact time. the experimental equilibrium biosorption data were analyzed by langmuir, freundlich, temkin and dubinin ̶ radushkevic isotherms models. the langmuir model gave a better fit than the other three models by higher correlation coefficient, r^2. the maximum biosorption capacities calculated from the langmuir isotherm model were 526 and 417 mg/g, for coffee and tea, respectively at optimum conditions. the kinetic studies indicated that the biosorption process of the metal ions followed well pseudo-second-order model. according to the biosorption capacity, waste coffee and tea powder considered as an effective, low cost, and environmentally friendly biosorbent for the removal of cu (ii) ions from aqueous solutions