The origin and the mechanism of the increase of the dissolved manganese concentrations have been investigated to choose a system of demanganization well fitted b the site conditions.
The aquifer characteristics are a depletion of the dissolved oxygen amount and deposits of manganese oxides (Mn(IV)) on the detriments. Under these conditions the microflora utilizes these manganese oxides as a final electron acceptor (as demonstrated by in vitro experiments) and the solubilization of manganese takes place.
The field application of the Vyredox system increases the redox potential of the groundwater and the manganese concentration decreases. Nothing indicates that manganese precipitation and consequently warping of the water table takes place at the periphery of the oxygenated part of the aquifer.
Manganese, speciation, groundwater, bacteria, demanganization.
Dumousseau, B., Université de Provence, place Victor Hugo, 13001 Marseille, France