Treatment of iron and manganese in simulated groundwater via ozone technology

Abstract

This paper deals with experimental investigations related to removal of iron and manganese from simulated contaminated groundwater via ozone technology. Ozone as a powerful oxidizing agent, which was used in this study to oxidize iron and manganese converting ferrous ions (Fe 2+) iron to ferric state (Fe 3+) and (Mn 2+) to (Mn 4+) state, the oxidized salts will precipitate as ferric hydroxide and manganese oxide, that to reach the concentrations of these pollutants under their limit values in drinking water. The initial concentrations of (Fe 2+) and (Mn 2+) in synthetic water sample under study were 2.6 mg/l and 1 mg/l respectively. The effects of ozone dose concentration, operating temperature, and pH on the percentage removal of (Fe 2+) and (Mn 2+) have been discussed. For optimum removal of iron and manganese species the ozone dose has been noted as 3 mg/l at optimum temperature of 20 °C which improved removal of (Fe 2+) and (Mn 2+) to more than 96% and 83% respectively. The removal percentage of both metals was also affected by changing pH with the range of 5–12; where the maximum removal of iron and manganese was observed in pH (9–10). Experiments also studied the effects of coagulant type and bicarbonate concentration in raw water, as a result it was found that the optimum concentrations of coagulant was a mixture of 30 mg/l of aluminum sulfate with 10 mg/l of lime.