EFFECTS OF VARIOUS ELEMENTS ON ARSENIC ACCUMULATION OF THE ALGA DUNALIELLA-SALINA

The effect of 23 various elements (nitrogen, manganese, magnesium, mol ybdenum, zinc, selenium, gallium, nickel, cobalt, lithium, strontium, vanadium, tin, antimony, bismuth, cadmium, chromium, lead, iron, silve r, copper, potassium and calcium) in water on growth and arsenic accum ulation in Dunaliella saline was investigated. The order of growth inh ibition of D. salina by these elements was Ag > Cd > Co > Ni > Cu > Zn > Fe > Sb > Ga > Cr > Bi > Sr > Mn > Sn > Se > Pb > V > Ca, Mg, Mo, K , Li. Arsenic accumulation in D. salina was unaffected by an increase in calcium and chromium. Also, the arsenic content in D. salina decrea sed at a potassium concentration of 100 mg dm-3, and was also reduced by the addition of cadmium and nitrogen; however, it was increased by the addition of lithium at 100 mg dm-3, tin, gallium, bismuth, stronti um, vanadium, iron and manganese at 10 mg md-3, lead, antimony, zinc, copper cobalt and nickel at 1 mg dm-3, selenium at 0.1 mg dm-3, and si lver at 0.005 mg dm-3, respectively. These results imply that arsenic accumulation by D. salina depends upon biological activity and physica l adsorption.