Category: Research Theme 3

Competing belief about biosolids and their transformation technologies have restricted their application and acceptance. This includes resistance to their adoption among farmers, who may identify important limitations with proposed biosolids products that researchers need to take account of in order to develop improved, appropriate products.

Resistance to biosolids use may be also rooted in farmers’ and others’ lack of understanding of biosolids products, and their perceived (versus actual) risks of biosolids and related products.

The PhD student will focus on identifying the social and industrial knowledge basis of biosolids and related products, the perceived risks of process technologies and materials application, and the practical challenges and opportunities they pose for farmers. By procuring this information, the project can design appropriate strategies for improving the products and reducing their actual and perceived risks.

The ICPD will subsequently investigate existing tools to improve communication and transparency between utilities and the community about the production and distribution of biosolids products. From here the project will identify specific community and industry barriers to biosolids acceptance and application at scale, and enhance existing tools to address these barriers and promote biosolids benefits.

These tools, as well as improving biosolids awareness, will be measured in their ability to improve biosolids feasibility and acceptability. In this way, the project will ensure a sustainable biosolids market via the development of industry-appropriate tools.

Biosolids transformation includes managing a range of chemical, stability and pathogenic risks to protect public health, reduce nuisances and maximise the benefits of the use of this resource. In Australia, biosolids are regulated at the state level, using outdated guidelines, still largely based on risk management concepts originally published in the 70’s by the USEPA.

While some states have attempted to update the guidelines, many challenges remain. One of these challenges relates to the exposure pathways for persistent emerging contaminants such as hydrochlorocarbon pesticides, brominated flame retardants, per fluorinated alkyl substances (PFAS) and endocrine disrupters.

The PhD student and ICPD will work together to develop a comprehensive validation framework for biosolids recycling schemes, with an emphasis on emerging contaminants for existing processing technologies, enabling the development of new, robust Australian Guidelines for Biosolids Management. Such guidelines will place emphasis on developing biosolids safety plans and process barrier monitoring, rather than an over-reliance on conventional end-point quality monitoring.

In Australia most biosolids are applied on agricultural land, providing a range of benefits including carbon sequestration, increasing water holding capacity and providing nitrogen, phosphorus and micronutrients to the soil. However, the economic benefits in terms of renewable energy generation, chemical fertiliser offsetting and increased drought resistence, while acknowledged, have not been comprehensively investigated.

This project aims to develop a generic and flexible framework for the solids processing train of existing and new biosolids treatment technologies. It will also develop pathways to enable the comparison of alternatives.

An existing innovative, economy-wide hybrid life cycle assessment tool will be adapted to enable Triple Top Line assessments for advanced transformation of biosolids and its management.

The major task of the PhD student will be to develop the hybrid life cycle assessment tool and its application in biosolids transformation and management.

The ICPD will work closely with water and agriculture industries and EPAs and will develop formal recommendations for these industries to consider.

Odour emissions remain one of the major challenges for community acceptance of biosolids. Attempts to incorporate an odour classification into the regulatory framework has not yet been successful in Australia.

The project will develop a new odour classification system for biosolids by investigating the fundamental science on how odours are formed and emitted. There has been work done in this area already; however, there still exist wide gaps in our knowledge about

• how biological and chemical stability impact odour potential,
• how different processing routes result in quantitatively different odours, and
• how different materials should be handled for minimising odour formation.

The PhD student will work on deriving the fundamental science governing biological and chemical stability and identify links between stability and production routes with odour.

The ICPD will focus on developing an odour classification system in an Australian context that can be considered for incorporation into a regulatory framework.