Multicomponent Biosorption of Heavy Metals Using Fluidized Bed of Alga

The biosorption of lead, cadmium, copper and arsenic ions by using native algae were investigated. Experiments were carried out in batch reactor to obtain equilibrium and kinetic data. Experimental parameters affecting the biosorption process such as pH, contact time, initial metal concentrations and temperature were studied. The optimum pH for removal were found 3, 5, 4 and 5 for Pb2+, Cd2+, Cu2+ and As3+ respectively. The biosorption of these metals is based on ion exchange mechanism accompanied by release of light metals such as calcium, magnesium, potassium and sodium. Experimental isotherms data well fitted an ion exchange model and the affinity constant was calculated for each metal. The results showed the ion exchange model was found suitable for describing the biosorption process. Fourier Transformation Infrared Spectroscopy analysis was used to find the effects of functional groups of algae in biosorption process. The results showed that Pb2+ has a greater difference in the peak values of absorbance bands then As3+ and Cu2+, while Cd2+ was the lowest. The experimental data showed that the biosorption of four metals were fitted well the pseudo-second order model.