Operational causes of bulking ...
Published by liz Victor, WWT industry - chief chemist
Operational causes of bulking
Some of Operational causes of bulking include
1. low dissolved oxygen in the aeration tank
2. insufficient nutrients: Especially quantity of nitrogen and phosphorus important, also absence of trace element cause bulking.
3. widely varying organic waste loading
but the limited dissolved oxygen has been noted more frequently than any other cause for sludge bulking. If the problem is due to limited D.O. Aerating equipment should operate at full capacity. At least 2 mg/L of dissolved oxygen in the aeration tank (under normal loading conditions) should be maintained.