Laboratory bioaccumulation of copper, lead and selenium in the marine alga dunaliella tertiolecta metal pair situation

Abstract

Individual and combined effects on the bioaccumulation of three heavy metals; namely, copper, lead and selenium, in the unicellular green alga Dunaliella tertiolecta were determined in natural sea water enriched with f/ 2 medium. Exponentially growing cells of alga were exposed to the three metals in the form of Cu(NO3)2 5H2O, Pb(NO3)2 and Na2SeO3 5H2O for 24 h. The pH effect on the bioaccumulation of each metal has been investigated. Total copper and lead concentrations were measured by atomic absorption spectrophotometer, whereas total selenium concentration was measured by spectrofluorometer. The bioaccumulation of metals occurred in a dose‐dependent manner. When pH decreased, the bioaccumulation of copper decreased significantly, but the bioaccumulation of lead and selenium almost stayed constant. The presence of copper interacted antagonistically with lead in various bimetallic combinations. Lead showed no effect on the bioaccumulation of copper. Coexistence of selenium with lead and copper showed antagonistic behaviour on the growth of alga microscopically.