In the present study, the Cr (VI) ion removal from synthetic wastewater utilizing sawdust as a rather inexpensive adsorbent studied by the batch adsorption technique. The sawdust physiochemical characterizations done through employing FTIR and BET analyses. Experiments performed at temperature range of 25-65 ºC with 0.5-5 g/L of sawdust dosage. Moreover, these conditions applied to separate Cr (VI) ion concentrations of 1-6 ppm in the pH range of 3-10. The adsorption parameters determined using both an A-Priori Langmuir and a heterogeneous surface displayed by the Freundlich isotherm models. Thermodynamic standard free energy ((Go), enthalpy ((Ho) and entropy ((So) calculated for predicting the nature of adsorption. Experimental results revealed the maximum adsorption yield achieved at pH of about 3. Furthermore, the temperature and adsorbent dosage led to positive effects upon adsorption yield as well. On the other hand, the adsorption efficiency increased through enhancing the Cr (VI) ion initial concentration up to 4 ppm. Nonetheless, further increase of this concentration lowered the mentioned separation efficiency.
