alkali activated cedar wood as an efficient adsorbent for pb2+ removal from aqueous solutions: optimization, kinetic and thermodynamic study

In the present study, activated carbon prepared from cedar wood was synthesized, ‎via naoh activation, and optimized to be used as the adsorbent for pb2+ removal ‎from aqueous solutions in a batch process mode. the physicochemical properties ‎of the synthesized adsorbent were examined by sem, ftir and bet analysis. in ‎order to determine the optimum operational conditions, the effects of different ‎parameters including ph, adsorbent dosage, contact time, temperature, and initial ‎pb2+concentration on the adsorptive performance of synthesized samples were also ‎investigated. according to the obtained results, the highest pb2+ ion adsorption ‎capacity (971.9 mg/g) took place at the optimum operational condition of ph=4, ‎adsorbent dosage of 0.025 g/l, contact time of 60 minutes, 300 ppm of pb2+ and ‎‎30 ℃. the results showed that among langmuir, freundlich, and temkin ‎isotherms, the obtained data were fitted the best with the freundlich model. ‎additionally, the process of pb2+ adsorption was consistent with the pseudo-‎second-order kinetics model, indicating that chemical adsorption was the dominant ‎mechanism of adsorption. finally, according to the calculated thermodynamic ‎parameters, i.e., ∆h°, 〖∆s〗^° 〖∆g〗^°, pb2+ adsorption on activated cedar ‎wood can be considered as an exothermic and spontaneous process.‎