Biosorptive removal of lead (II) ions from aqueous solutions using Cystoseira stricta biomass: Study of the surface modification effect

A brown marine alga, Cystoseira stricta, has been studied for its biosorption capacities of the heavy metallic ion, the Pb(II), in aqueous solutions. The brown alga (C) has been used without previous treatment and with chemical treatment to acid (H2SO4 1 M: CS) and to sodium hydroxide (NaOH 1 M: CB). The results have shown the influence of the particle size of the biomaterial on the extraction-removal of Pb(II). The application of the Langmuir adsorption model revealed the maximum capacities of adsorption of each material (C, CS, CB). The one specific to C. stricta treated by a solution of sodium hydroxide 1 M (CB) was the most important (65 mg g^-1). The established isotherms at different temperatures showed that this parameter affects the adsorption. The best results are obtained for a temperature of 25 °C, in comparison with those recorded at 50 C. Finally, the results of this study showed that C. stricta can be a good potential biosorbent of heavy metals, in particular, when it is treated by a basic solution.