| A Secondary Maximum Contaminant Level for manganese of 50 μg/L (0.05 mg/L) has been set by the U.S. Environmental Protection Agency to help control aesthetic and operational problems associated with the presence of manganese in drinking water. The water treatment plants at Brookings, South Dakota have demonstrated the ability to consistently remove manganese to this level, but could be further optimized to remove manganese to even lower levels.; The objective of this project was to investigate and recommend changes in the treatment processes in order to optimize manganese removal at the two Brookings Water Treatment Plants. A treatment goal of 10 μg/L (0.01 mg/L) residual manganese was established at the onset of this project. Two manganese removal alternatives were studied and compared: manganese oxidation using potassium permanganate, and manganese precipitation through lime softening.; The test results revealed that both manganese treatment alternatives were able to remove manganese to very low levels close to, or below, the treatment goal of 10 μg/L. However, the water plants would be able to achieve this goal using the precipitative softening alternative with less cost than would be necessary using the manganese oxidation alternative. |
