Anaerobic ponds are widely used in the meat industry as the first stage of secondary treatment of abattoir wastewater. They are popular because they have a high BOD (Biochemical Oxygen Demand) and COD (Chemical Oxygen Demand) removal efficiency of around 90%, with a reasonably sized footprint and low operational costs; however, they have a couple of issues:

• odour emissions; and
• the biogas produced contains a high percentage of methane (CH₄₎ which is a powerful greenhouse gas with a global warming potential (GWP) 21 times that of carbon dioxide (CO₂).