IMPACT OF MANGANESE ON CORROSION CONTROL AND BIOFILM FORMATION IN DISTRIBUTION SYSTEMS

Abstract

The fate of manganese in distribution, along with its impact on biomass accumulation and lead release was investigated at the bench-scale. Confirmation of manganese-biofouling of the JD Kline Water Supply Plant’s raw water pipeline demonstrated the importance of manganese oxidizing bacteria on the accumulation of manganese in distribution. A second study investigated the impact of phosphate and manganese on biofilm accumulation. Lead pipe sections were run in series of this study, to determine the impact of residual manganese and phosphate on lead release. Phosphate was shown to reduce manganese accumulation, while increasing microbial populations. Lead pipes exposed to manganese experienced greater lead release, with lead concentrations increasing from 573 ug/L to 1048 ug/L. Following stagnation, these lead concentrations increased to 7121 ug/L and 13 754 ug/L, respectively. These results demonstrate the complex role of manganese in distribution systems, emphasizing the importance of manganese removal during treatment.