Influence of hydrogen cations on kinetics and equilibria of heavy-metal sorption by algae—sorption of copper cations by the alga Palmaria palmata (Linnaeus) Weber & Mohr (Rhodophyta)

The influence of hydrogen cations on kinetics and equilibria of sorption of copper cations by the marine alga Palmaria palmata (Linnaeus) Weber & Mohr was studied under static conditions. The competitive effect of the H(+) cations is described, which influenced the uncertainty of evaluation of the alga sorption capacity. Under static conditions, the variation of the Cu(2+)/H(+) concentration ratio during sorption was found nonmonotonic. The Langmuir isotherm model was used to determine the sorption capacity of the alga, namely 12.4 mg g(−1) of dry algae mass. A similar value was determined from the kinetic parameters of the ionic exchange which is considered a pseudo-second-order chemical reaction. The consistent results indicated that the mathematical models used correctly described the equilibria and kinetics of the ionic exchange between algae and solutions.