Anaerobic digester foaming: causes and solutions

摘要

Foaming in anaerobic digesters is a complex problem to solve and is an issue that is likely to become of greater significance as the need for nutrient removal spreads. DR WILLIAM BARBER looks at likely causes and solutions to this difficult challenge. Foarning during sludge treatment has traditionally been associated with activated sludge systems, which have fallen victim to this phenomenon for several decades. However, foaming has also been documented in anaerobic digestion plants, bringing about, fundamentally, a reduction in digester capacity and an increase in operational expenditure. The prerequisites for foaming - surface active agents, a gaseous phase and hydrophobic material - are all present in an anaerobic digester.