Accumulation of Ag, Cd, Co, Cu, Hg, Ni and Pb in Pavlova viridis Tseng (Haptophyceae)

Abstract

The flagellate alga Pavlova viridis Tseng was investigated in the laboratory for accumulation of the heavy metals, silver, cadmium, cobalt, copper, mercury, nickel and lead. The cultures were grown in an artificial seawater medium mixed with the individual metals at different concentrations. Based on data from the controls, the baseline metal concentrations in P. viridis were shown to be in an order of Cu > Pb > Co > Cd > Ni > Ag > Hg. In the experimental groups, the seven metals displayed different isotherm equilibrium patterns and the metal uptake capacity of the alga was Ni > Pb > Co > Hg > Cu > Cd > Ag at equilibrium. When assessed using the bioconcentration factors, metal accumulation by P. viridis was demonstrated to be the most efficient at a concentration of 0.001 mg L-1 for Ag, Cd and Co, and at 0.01 mg L-1 for Cu, Hg, Ni and Pb. This study suggests that P. viridis can be a source of mineral supplements in mariculture. The alga is not, however, recognized as an effective agent for removing heavy metals from wastewater.