Mathematical models for estimating fluxes at the sediment-water interface in benthic chamber experiments

Experimental data collected by means of benthic chambers have been used to develop simple mathematical models in order to predict heavy metal and non-metal fluxes at the sediment-water interface. In particular, two mathematical models have been applied to Ba, Co, Fe, Pb, Mn and Cu.Both models estimate benthic fluxes by means of Fick's law but they differ in the modelling of partition between liquid and solid phases. The first model, which is appropriate for Ba and Co, assumes that sorption is the most important process in determining partition. The second model, which gives discrete results for Fe and Pb, assumes that precipitation is the most important process determining the time variation of concentrations. Neither model is suitable to explain experimental data for Mn and Cu.This paper demonstrates the benefit of the use of mathematical models in the interpretation of benthic chambers experiments and in the identification of the relevant processes occurring at the sediment-water interface.