Binding of lead to P. Tricornutum and T. Weissflogii cultures in seawater

Abstract

Titrations using differential pulse anodic stripping voltammetry (DPASV) to detect electroactive lead were carried out in Phaeodactylum tricornutum and Thalassiosira weissflogii seawater cultures to determine the extent of lead complexation with both dissolved ligands and cell surface groups. Adsorption and complexation parameters in a heterogeneous model were determined as a function of pH, temperature, and salinity and cell concentration by using a new iterative method. Lead forms high stable complexes in seawater and organically complexed lead fraction constitutes a significant portion of the total lead. Higher affinity for lead is observed by the surface groups of T. weissflogii in respect to P. tricornutum showing that the functional groups of T. weissflogii are more specific in the presence of 100 nM Cu(II) in solution.