Recovery by Dunaliella salina of Cadmium from Water

A method was described to collect the cadmium ion in water with the boiling water-treated powder algae of Dunaliella salina (BWP). The algae powder was treated with the boiling water. A 10 ml solution containing Cd²⁺ was mixed with 10 mg of the BWP under stirring for 30 min. The solution was then cen-trifuged or filtered through a glass fiber filter (0.2 μ;m) and the concentrations of cadmium ion in the filtrate were determined with an atomic absorption spectrometer. The amount of cadmium absorbed in the BWP became a maximum at 15 min after exposure. In a mixed solution of Cu²⁺, Mn²⁺, Co²⁺, Zn²⁺, Fe²⁺, and Ni²⁺, the collect of the metals by the BWP was Cu> Fe> Cd> Zn, Co> Mn. The cadmium collected by the BWP increased with an increase in the concentration of nitrogen in the growth medium. The amount of cadmium absorbed in the BWP increased with an increase of the amount of algae in water. The amounts of Cd absorbed by the BWP treated with a alkali (ABWP) was increased and the amounts of Co, Cu absorbed in ABWP were decreased.