Biosorption Of Cd~(2+), Cu~(2+), Ni~(2+) And Zn~(2+) Ions From Aqueous Solutions By Pretreated Biomass Of Brown Algae

摘要

In this paper, marine brown algae Laminaria japonica was chemically modified by crosslinking with epichlorohydrin (EC_1 and EC_2), or oxidizing by potassium permanganate (PC), or crosslinking with glu-taraldehyde (GA), or only washed by distilled water (DW). They were used for equilibrium sorption uptake studies with Cd~(2+), Cu~(2+), Ni~(2+) and Zn~(2+). The experimental data have been analyzed using Langmuir, Fre-undlich and Redlich-Peterson isotherms. The results showed that the biosorption equilibrium was well described by both the Langmuir and Redlich-Peterson isotherms. The order of maximum metal uptakes for Cd~(2+), Cu~(2+) and Zn~(2+) was EC_1 > EC_2 > PC > DW > GA, but the uptakes of Ni~(2+) are almost the same for these sorbents. Moreover, sorption kinetics has been performed and it was observed that the equilibrium was reached in less than 2 h, which could be described by pseudo-first-order kinetic model. The metal adsorption was strictly pH dependent. The optimum pH values of four metals were in the range of 4.3-6.5 for all sorbents, and the optimum solid/liquid ratio was 3.0 g L ~(-1).