Author Dr Ruth Fisher
Date December 17, 2021

Codigestion of food waste is emerging as an increasingly popular method to recover additional energy while using existing wastewater treatment infrastructure.  However, the addition of substrates will also influence the quality of downstream biosolids, potentially affecting re-use opportunities.

In a new paper published in Science of the Total Environment, the impact of codigestion on downstream biosolids quality was investigated by measuring the concentrations of trace organic compounds and metals in the digested sludge following codigestion.  Article link – see HERE

The paper showed concentrations were dependent on the type of food waste added, with significant differences in concentrations compared to the control for compounds such as caffeine and Bisphenol A which were found in high levels from beverage wastes.  Caffeine, diuron, triclosan and triclocarban were found to present a potential high risk of impacts on the soil ecosystems as judged with environmental risk assessment.

Currently much of Australia’s biosolids are applied to agricultural land providing nutrients as well as improvements in water retention.  This paper support that care should be taken to protect biosolids quality, through careful monitoring and source control to ensure that biosolids land application provides benefits without potential impacts due to contamination.

See article for Diagram.

If you are interested in helping map how codigestion can be integrated sustainably and more widely in biosolids management in Australia – we are currently advertising for a PhD student in this area.  See HERE.