Screening of algae material as a filter for heavy metals in drinking water

Calcium alginate beads generated from alginic acid sodium salt from brown algae were used to explore the adsorption processes of lead and copper ions in water. The main parameters in the experiment were initial pH, equilibrium time, and concentration of metal ions. The adsorption processes of lead and copper were carried out under specific pH values. Moreover, the multiple adsorption of lead and copper was carried out to study the competition of two metal ions. It was found that the highest adsorption percentage of lead and copper was achieved under the optimum pH respectively. Meanwhile, the highest adsorption percentage of multiple adsorptions was lower than that of single metal adsorption under pH of 4. The optimum pH was utilized in the kinetic experiment and equilibrium experiment. The pseudo-second-order kinetic equations would fit the experimental data well. The maximum amounts of adsorption for lead and copper based on Langmuir models were 250 mg/g and 62.5 mg/g respectively.