AWWA JAW10211

A typical treatment process for removing iron and manganese from groundwater was not effectively reducing iron and manganese concentrations to less than or equal to 0.05 mg/L and 0.01 mg/L, respectively, in the village of Roxana, Illinois. After using temporary measures, the village began looking at several long-term alternatives to solve the water quality problems. Of the alternatives considered, oxidation and removal of manganese with potassium permanganate was investigated further in bench studies. Modification of full-scale treatment affected the removal of manganese by using permanganate feed, ferric hydroxide from the reaction basin as a primary coagulant, and a cationic polymer as a coagulant aid. Reclamation of backwash eliminated a potential problem with disposal of the backwash. Both manganese and iron were reduced to acceptable levels. In addition, the increase in pH helped decrease corrosive water conditions in the distribution system, and the duration of filter runs was lengthened. Includes 7 references, table, figures.