Modeling, kinetics and isotherm of lead biosorption by Chlorella vulgaris

Document Type : Research Paper


1 Assistant Prof./ University of Guilan

2 Assistant Prof./University of Guilan

3 Assistant Professor /University of Guilan


One of the most effective technology to remove heavy metals is using of bio-absorbent. In the present study modeling, kinetics and isotherm of lead sorption by the unicellular green algae Chlorella vulgaris from aqueous solutions was assessed. After culturing algae in Z+ medium and reaching the logarithmic phase, it was harvested and centrifuged, then dried by freeze dryer. Afterward, through the evaluation of parameters affecting the biological absorption, the isotherms and adsorption kinetics of the metal were calculated and determined. Results indicated that with increasing of adsorbent amount, adsorption was decreased. Also, after increasing of the initial concentration of metallic ion, metal removal rate was reduced. Furthermore, absorb kinetic studies showed that the biosorption of lead by C. vulgaris following second-order kinetics and adsorption isotherm is well fitted to the Langmuir model. Also, modeling heavy metal removal using multivariate linear regression indicated that the biosorption process and the effect of parameters on it can be described by a quadratic equation. This equation revealed that pH is the most effective parameter on metal removal by C. vulgaris.