Effects of Iron on Activated Sludge Treatment

The importance of inorganic nutrients on activated sludge treatment has not been emphasized or studied extensively. Studies of the fundamentals of inorganic ions have been limited to nitrogen and phosphorus, yet basic microbiology has shown the importance of many other nutrients. Iron plays a major role in the oxidation-reduction reactions involved with the treatment of organic wastes and was the subject of this investigation. This work showed that insufficient iron in activated sludge treatment systems decreases the rate of organic metabolism and causes bulking conditions. Variations in other biological treatment parameters may be associated with iron or other inorganic nutrient limitation conditions.