Effects of pH on isotherms modeling for Cu(II) ions adsorption using maple wood sawdust

The biosorption of copper (II) ions from aqueous solution by an unconventional adsorbent maple wood sawdust was studied as a function of different environmental parameters such as pH, contact time, adsorbent concentration, initial Cu(II) ions concentration and others. Adsorption was carried out in a batch process and it was observed that an increase in the adsorbent concentration with constant copper ions concentration resulted in greater metal removal from solution. Higher metal loading per unit of weight of sorbent was observed with increasing initial copper ions concentrations for a constant sorbent dose. The Langmuir and the Freundlich adsorptions models were applied to describe isotherms and isotherm constants considering the most important parameter, pH. The variation of adsorption isotherm constants showed pH dependence. The isotherms studies revealed that the maximum copper (II) ions adsorption (qm) 9.51 mg/g maple wood sawdust was obtained at pH value of 6.0.