Statistical screening of hexavalent chromium biosorption by Sargassum

The aim of this study was to investigate the statistical screening of hexavalent chromium, Cr (VI), from an aqueous solution using brown seaweed Sargassum as a biosorbent. The biosorption process conditions were evaluated with the statistical screening followed by Plackett-Burman design. The effect of solution pH, contact time, initial chromium and nitrate concentrations were studied. The experimental data were fitted to the Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. Plackett-Burman design showed the contact time and pH are the most important parameters influencing the Cr (VI) biosorption onto Sargassum. The optimum pH, contact time, the initial biosorbent dosage and initial Cr (VI) and nitrate concentration were found to be 3, 120 min, 1.3 g, 50 mg/L and 1000 mg/L, respectively. The results indicated that the Freundlich model was the most suitable for Cr (VI) biosorption onto Sargassum.