Adsorption and Desorption Potential of Cadmium Using Green Algae: Equilibrium and Kinetic Studies

Microalgae has a diversity of species found in freshwater bodies but only a few have been explored for their biosorption potential as compared to macro algae (sea weed). Equilibrium and kinetic experiments were used to estimate sorption capacity and rate of reaction respectively. Chloroidium saccharophilum had the highest sorption capacity (qmax) of 200 mg/g and lower affinity (b) of 0.0095 L/g for removal of Cd. However, Stichococcus bacillaris was the best adsorbent for Cd as it had both a higher qmaxand higher b of 125 and 0.049 L/g. The Langmuir and Pseudo-second order models performed better than the Freundlich and First-order models with a regression coefficient (R2) > 0.9. Adsorption and desorption efficiency was achieved highest for Stichococcus bacillaris at 95.8% and 73.49% respectively.