Competitive sorption of metals ions from aqueous solution onto silica sand.

The major part of the contaminants present in groundwater interacts strongly with soils and aquifer rocks. For this reason, contaminants sorption processes on porous matrix are of general interest in hydrology and of utmost importance in the frame of confinement of industrial and civil wastes as well as in long-term geological disposal of high-level nuclear waste. In this study, kinetic and equilibrium, mono-component and multi-component, batch experiments were carried out in order to: i) study the influence of metal concentration and contact time on sorption onto silica sand of some safety-relevant metal ions in aqueous solution, such as Cs1+, Sr2+, Cu2+, and ii) investigate competitive sorption processes. Metal ions concentrations in aqueous solutions were determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) measurement technique. Sorption data were fitted with Linear, Langmuir and Freundlich models. The amount of each ion uptake observed in multi-component batch tests was compared with the corresponding uptake observed in mono-component batch tests and correlated to the equilibrium time of the ions present in solution. Bi-component batch tests data were interpolated so as to obtain a database that can be used for modelling studies.