Category: Research Theme 2

There has been significant progress made in the last decade in converting biomass waste into value-added advance carbon materials using thermochemical methods.  Biosolids, however have not been investigated properly for value-added product formation and their future applications.

This project will identify and test new indirect agriculture applications of high value biosolids-based advanced carbon materials such as biochar, hydrochar and activated char produced by various advanced thermochemical methods (e.g. pyrolysis, gasification and hydrothermal liquefaction).

The PhD student will mainly develop and test new applications of these carbon materials in water and soil remediation as well as odour reduction.

The ICPD will examine the techno-commercial viability of the advanced thermochemical processes and their different applications and will prepare recommendations for the water industry.

Attempts to increase organic carbon in Australian cropping soils by means such as retaining crop stubble, adding compost, and growing green manure crops or perennial pastures have achieved very little; soil carbon is still decreasing in many soils. Maintaining organic carbon in cropping soils will aid amelioration of rising atmospheric carbon dioxide and improve soil physical and chemical characters, thereby aiding crop yields.

Recent Australian research shows functionalisation of carbon by keeping correct ratios of key nutrients (C: N: P: S) can help carbon transformed into persistent forms. However, research on functionalising carbon in biosolids or biosolids-related products such as biochar or hydrochar remains limited in this area.

The PhD student will investigate if blended biosolids can be used to produce a safe and cheap (transportable) product with optimal ratios of key nutrients, to aid the formation through the actions of soil microbes of stable organic carbon in the soils of the broadacre cropping systems in southern Australia.

The 0.4 ICPD will investigate how biochar and hydrochar, produced from pyrolysis or hydrothermal processing of biosolids, can help restore soil carbon and compare them with biosolids blended with nutrients and other forms of carbon produced from a PhD project.

Current uses of biosolids as fertiliser are largely in low-value landscaping applications, where tailored and consistent formation is not required. A shift to using biosolids in high value agricultural and retail products will require tailored formulations, informed by robust testing, resulting in known impact on target plants and easy, cheap delivery (e.g. concentrated, dry, granular products).

Achieving desirable nutrient formulation may be best achieved by blending with other waste streams, such as food and chicken waste.

Challenges to be tackled by the Centre are those that contribute to meeting goals for plant nutrition, growth, yield, and final product quality and safety in terms of pathogens and contaminants. Goals may also be regionally specific; for example, the need for low phosphorus (P) formulations in areas with P-enriched soils and environmentally unacceptable off-farm P movement, such as Peel Harvey in Western Australia.

Target industries could include turf, specific ornamentals, fruit trees and vegetable crops (home or commercial), and broadacre crops.

The Masters student will focus on optimising and integrating unit operations such as composting, drying and granulation, while the PhD student will look at developing and testing different recipes to tailor end product suitable for various applications in horticulture, agriculture and greenhouses.

The ICPD will work with the HDRs and also independently perform horticulture, agriculture and greenhouse trials to develop recommendations for industry.