Investigate biosorption-desorption of heavy metals by the dried biomass of algae

Abstract

Evaluating the abilities of dried biomass ofalgae and aquatic plants to remove heavy metals ions in the solutions through adsorption and desorption. This study not only focus on single component systems but also the binary mixtures of heavy metals. The biosorbents which are used in this study: Dunaliella viridis, Ceratophyllum demersum and water hyacinth (Eichhornia crassipes) while the heavy metals are Copper and Zinc. In Copper adsorption capacity experiment, the water hyacinth shows that all its part (roots, stems, leaves) has a whole range of possibilities in heavy metals pollution‟s treatment. , water hyacinth in this research points out that its Copper adsorption capacity is five times more than Dunaliella viridis (micoralga). In the binary mixtures experiment, Ceratophyllum demersum has the adsorption capacity for Zinc higher than Copper. Not stop at that, it also demonstrates the capacity toward binary mixtures with Zn and Cu even though the adsorption capacity for the heavy metals seemed to be lower in the binary mixture cases than the single component system. In further, through adsorption-desorption experiment, C. demersum can also reuse and recover all the metal it adsorbed during the adsorption with the right treatment. After 3 cycles of adsorption-desorption, desorption ratio of each is still really high (more than 97%) but the totally desorption ratio is reduced to 82% because of the weight loss of the biomass during the process. Keywords: Adsorption; Desorption; Heavy meatal(s); Dunaliella viridis; Ceratophyllum demersum; Water hyacinth (Eichhornia crassipes)