Iron and manganese removal from groundwater : geochemical modeling of the Vyredox method

Drinking water supplies are based on ground water resources all over the world. At some localities problems with higher concentrations of iron and manganese found in ground water. These higher concentration of these metals result in metallic taste of water, effect color and flavor of food and cause staining of different products like paper, cloths, and plastics. Therefore World Health Organization has approved the treatment of water if concentrations of iron and manganese are higher than 0.3mg/L and 0.1 mg/L. Several techniques have been applied to remove iron and manganese from groundwater.' The issue of higher concentrations of iron and manganese in groundwater wells at Grindalsmoen in Elverum Municipality in the south eastern part of Norway has been investigated by a PHREEQC geochemical model. The aim of this investigation was to analyze the relationships between oxygen levels and precipitation rates of iron and manganese. For this purpose geochemical simulations were performed with PHREEQC model with radial and linear flow. Results proved that concentration of oxygen at the water works (at its corresponding partial pressure) is high enough to precipitate the level of iron and manganese found in groundwater. The concentration of oxygen in equilibrium air at our desired temperature of 6 degree centigrade was 12.3 mg/l calculated by PHREEQC. Geochemical simulations were performed by the one dimensional column flow and radial flow towards well. The phenomenon of sorption was also included in model to see the adsorption behavior of iron and manganese. Overall this geochemical study has provided satisfactory results