Ideal biosorption materials are able to rapidly adsorb high concentrations of heavy metals from waste emissions and use chemical agents to desorb heavy metals from biosorption material .
For these reasons, the results of Spirogyra and Cladophora spp. adsorption on Pb(II) and Cu(II) used the relationship between heavy metal adsorption and contact time as a function, as shown in Fig.
During the first 30 min, adsorption rate of both materials was extremely high, comprising approximately 95% of the total adsorption.
Then, the rate began to drop toward a steady state, with insignificant levels of adsorption.
The two adsorption materials reached steady state for the same type of metal ion simultaneously, but achieved steady state at different times for different metal ions.
As observed in the adsorption curve, the rapid adsorption of lead in the first twenty minutes, and the rapid adsorption of copper in the first thirty minutes, may be due to physical adsorption or ion adsorption on the surface of the algae powder.
Slower adsorption that followed may have involved other mechanisms, such as complexation,
micro-precipitation, and binding site saturation.
This study observed three phases of Spirogyra and Cladophora spp. adsorption materials in the contact time adsorption curve: the initial phase, with rapid adsorption of heavy metal ions; the second phase, with gradual slowing of the adsorption rate; and the equilibrium phase, with no significant increase in the removal rate.
Mohan et al.described similar results.
It observed that two biomaterials performed for various durations in different phases, due to different adsorbed heavy metals.
For the adsorption of Pb(II) and Cu(II) single heavy metals, we discovered that the adsorption
capacity of Spirogyra algae was significantly higher than that of Cladophora algae.
In comparing the characteristics of biomass, FT-IR testing showed that functional groups were similar. However, plant bodies of Cladophora spp. often have large amounts of epiphytic algae, thus causing differences in adsorption volume.
Furthermore, differences in adsorption volume may be due to differences in proteins, lipids, or the composition of other carbohydrates affecting the number of adsorption sites.
The differences may be due to the epiphytic algae on Cladophora spp., which affects the quality of algae powder production.