AbstractThe biosorption of Zn(II) from aqueous solution by algal biomass was carried out in batch and column study. In batch experiments, the effect of the modification on four types of brown algae, Cystoseira indica, Sargassum glaucescens, Nizimuddinia zanardini, and Padina australis by Formaldehyde (FA), CaCl2, and HCl was investigated. The results showed that FA-treated S. glaucescens has the maximum metal uptake capacity (29.13 mg/g). The ability of S. glaucescens to remove Zn(II) was studied in a packed-bed column with 1.6 cm internal diameter. The column experiments were conducted to evaluate the effect of important design parameters such as bed height and flow rate, and the breakthrough curves were obtained. As the bed height increased, the breakthrough and exhaustion time increased, whereas the breakthrough curves slope decreased. The maximum dynamic capacity, 71.17 mg/g, was found in the column with 18 cm height and 4 mL/min flow rate. Several empirical models such as bed depth service time, Thom...