Evaluation of copper and lead biosorptionon modified azolla pinnata (r. br.)

Arielle Barros, Sirlei Kleiniibing Meuris da Silva

Chemical Engineering Faculty of the University of Campinas, Av. Albert Einstein 500, postcode:13083-852, Campinas, Brazil


This paper investigates the macrophyte Azolla pinnata modified with sodium hydroxide, as a bioadsorbent for Cu2+ and Pb2+ ions in synthetic solutions. Biomaterial characterization was performed using Scanning Electronic Microscopy (SEM); Energy- Dispersive X-Ray Spectroscopy (EDX); Fourier Transform Infra-red (FTIR) spectroscopy techniques and through the blocking of carboxylic and sulfonic functional groups. Kinetics of the process has highlighted a quick and efficient adsorption, even in low ion concentrations. Langmuir isotherm fitted well the biosorption equilibrium, and the maximum Cu2+ and Pb2+ uptake capacities were 0.448 and 0.472 mmolg-1 at 25oC and 0.474 and 0.614 mmolg-1 at 45oC, respectively. Desorption process was evaluated using different eluents and calcium chloride has presented the best desorption efficiency, moreover, did not cause visual damage to the material or decreased the adsorption capacity of the biomass.


biosorption; desorption; heavy metal; macrophyte

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