Characterization of alginate polymer and its application in copper removal from liquid wastes

Copper is one of the most dangerous pollutants that require removal from wastewater effluents before being discharged. Here are reported on the adsorption performance of a novel environmental friendly material, calcium alginate gel beads as a non-conventional technique for the successful removal of copper ions from aqueous solution. Batch equilibrium studies were carried out to evaluate the adsorption capacity and process parameters such as pH, adsorbent dosages, initial metal ion concentrations, stirring rates and contact times. It was observed that, the maximum removal of copper ions was occurred at pH 5.0 ± 0.02. An adsorbent dose of 1 g/L was optimum for copper ions removal within an equilibrium time. For all contact times, an increase in copper ions concentration resulted in decrease in the percent of copper ions removal (91.98%–49.96%) and an increase in adsorption capacity (4.59 – 49.93 mg/g) for copper ions concentrations 5 and 100 ppm, respectively. The mechanical stirring speeds greatly enhance the mass transfer rate of copper ions onto the adsorbent indicating 250 rpm is the optimum. The removal of copper ions occurs rapidly within the two hours (equilibrium time), followed by a slow removal process. The Langmuir and Freundlich's isothermal models were used to describe the experimental adsorption. The equilibrium adsorption data were well fitted to Langmuir isotherms (R 2 = 0.9959) and the maximum adsorption capacities of the calcium alginate gel beads were found to be (87.5%, 17.5 mg/g) were obtained at the optimum conditions on a Jar test at temperature 25 ± 3C for copper ions concentration 20ppm. The calcium alginate gel beads were characterized using Fourier transform-infrared (FT-IR) spectroscopy and Transmission electron microscopy (TEM). [M.S. Mahmoud and Ahmed M. Abou Elmagd. Characterization of alginate polymer and its application in copper removal from liquid wastes. J Am Sci 2013;9(11):432-439]. (ISSN: 1545-1003). http://www.americanscience.org. 54