Almost 350,000 tonnes of dry biosolids, or treated sludge from wastewater, are generated annually in Australia. This is a significant potential new nutrient source for the agriculture industry. However, heavy metals and emerging contaminants, particularly PFAS, found in biosolids is putting a considerable constraint on its use.
A team at the University of Newcastle, led by Distinguished Laureate Professor Ravi Naidu and Dr Yanju Liu, has been awarded $919,840 from the Cooperative Research Centre (CRC) for High Performance Soils. This research will investigate if the thermal conversion of biosolids to biochar, the charcoal created when burning organic materials, creates a safe nutrient source for agricultural use.
While biosolids have been used as a rich source of nutrients for a long time, the recent discovery of the presence of PFAS in these materials has led to a ban on the use of biosolids in farming. As a result, millions of tonnes of biosolids are being stockpiled in countries globally.
This project aims to determine if turning biosolids in biochar will remove organic emerging contaminants ensuring its safe use as a slow-release fertiliser. It will also look at the benefits of biochar to soil health and soil texture improvement.
This research will be critical for both the water and agriculture industries by providing strategies to use a current waste product as a viable and cost-effective fertiliser. It will be significant in assisting to minimise the biosolid stockpiles, leading to a reduction of billions of dollars in management costs.
