Application of Ca-Pretreated Brown Alga for Heavy Metals Removal from Esfahan Uranium Conversion Facility (UCF) Wastewater

The effect of heavy metals biosorption process parameters from the Esfahan Uranium Conversion Facility (UCF) wastewater by Cystoseira indica biomass was determined. The sorption capacities of heavy metals (U, Ni, and Cu) were studied by untreated biomass, biomass treated by formaldehyde and biomass treated by calcium solution and was concluded that the biosorption performance of biomass treated by calcium solution was better than the other adsorbents. Furthermore, the pH of 5 and equilibrium time of 120 min were obtained as the optimum conditions. Also, the kinetic data were well fitted with the pseudo-second-order kinetic model and the chemical reaction step was recognized to be the controlled- rate step. On the other hand, the results showed that the biosorption capacity decreased by increasing the biomass concentration. Also, the XRF analysis showed that the other heavy metals in wastewater were adsorbed by the Ca-pretreated brown algae. The FTIR analysis of adsorbent before and after the contact with wastewater showed that the functional groups of hydroxyl, carboxyl and amin had the most important role in the heavy metal sorption. Also, the BET analysis showed that the chemical adsorption of heavy metals changed the cell wall structure of biomass.