Investigation of Langmuir and Freundlich Adsorption Isotherm of Pb2+ Ions by Micro Powder of Cedar Leaf

ABSTRACTIn this work, the micro powder was the product of cedar leaf (MPCL) is used as a low-cost adsorbent for the removal of Pb2+ ions from aqueous solutions. Bath experiments were used to determine the best adsorption conditions The adsorption percentage of Pb2+ ions MPCL samples at different initial pH, contact time (tc), adsorbent dosage and temperature (T) were investigated. Effective removal of metal ions was demonstrated at pH values of 5. Metal adsorption onto MPCL was evaluated by Langmuir and Freundlich isotherms. Results indicate that the Langmuir isotherm model is the most suitable one for the adsorption process using MPCL (R2=0.9987), thus indicating the applicability of monolayer coverage of Pb(II) ion on MPCL surface. The relationship between thermodynamic parameters was used to predict the absorption process. According to Thermodynamic analysis, the process exothermic and natural (ΔHo= -21.65 kJmol-1 and ΔSo = - 56.4 kJmol-1 K-1).Keywords: Pb2+; adsorption; micro powder; cedar leaf; Thermodynamic; MPCL