RECOVERY BY DUNALIELLA-SALINA OF CADMIUM FROM WATER

A method was described to collect the cadmium ion in water with the bo iling water-treated powder algae of Dunaliella salina (BWP). The algae powder was treated with the boiling water. A 10 ml solution containin g Cd2+ was mixed with 10 mg of the BWP under stirring for 30 min. The solution was then centrifuged or filtered through a glass fiber filter (0.2 mum) and the concentrations of cadmium ion in the filtrate were d etermined with an atomic absorption spectrometer. The amount of cadmiu m 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 c ollected 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 am ounts of Cd absorbed by the BWP treated with a alkali (ABWP) was incre ased and the amounts of Co, Cu absorbed in ABWP were decreased.