Australasian Science: Australia's authority on science since 1938

This Little Piggie Went Wee Wee Wee

Credit: dusanpetkovic1/Adobe

Credit: dusanpetkovic1/Adobe

By Jeremy Ayre & Navid Moheimani

Microalgae strains that can survive the extreme conditions in piggery effluent could not only clean up the wastewater but also reduce greenhouse emissions, provide a source of biofuel and even be fed back to the pigs.

The full text of this article can be purchased from Informit.

Pork is the most highly consumed animal meat globally, with the pig population currently numbering around 900 million worldwide. Australia has roughly one pig for every ten citizens, so pig production here requires significant effort to keep environmental impacts in check while remaining economically viable.

Wastewater management is one of the important challenges. Piggeries are quite good at isolating their wastewater to prevent the contamination of nearby streams and groundwater, and this seems to be a proven part of the environmental strategy. The wastewater holding ponds utilised by piggeries also provide a treatment that involves anaerobic digestion of the waste to reduce the nutrient load and make the wastewater more manageable.

Pig producers are also moving toward covered ponds that can capture the methane produced and substantially reduce the associated odour. The methane can be a useful on-farm biofuel, and also allows for a reduction of greenhouse gas emissions as the carbon dioxide output from combusted methane is a comparatively less potent greenhouse gas.

Unfortunately there is still no economical and widely used option for treating the anaerobic digestate of the wastewater, apart from evaporative ponds that essentially allow the water to become lost into the atmosphere. This obviously doesn’t allow for very effective water recycling....

The full text of this article can be purchased from Informit.