Covered Anaerobic Ponds
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).