Absorption of different types of DOM to two marine phytoplankton species and its effects on Pb bioavailability

摘要

Dissolved organic matter, as humic and fulvic acids, has surfactant properties that explain its tendency to accumulate on abiotic and biotic surfaces [1]. DOM adsorbed to cell surfaces can modify cell membrane characteristics, as surface charge and membrane permeability [2], which can influence metal uptake by the organisms [3]. Despite these considerations, the most considered effect of DOM on metal bioavailability has been its metal binding capacity, which controls free metal ion concentration in aquatic environments [4]. It has been observed that Pb bioavailability for marine invertebrates is enhanced in the presence of humic acids (HA) [5] despite formation of Pb-HA complexes and decrease of inorganic Pb concentrations.