Investigation into Resource Recovery approach, including biogas production Harvey Beef abattoir (WA)

Summary

Harvey Beef has a range of valuable by-products currently being disposed via composting and/or landfilling. Taking a holistic approach on the waste and wastewater management in the plant can offset considerably the investments required for long-term environmental compliance.

The design approach used in this report was based on combination the most recent knowledge available both in Australia and in Europe, and the design assumptions were carefully selected based on plants that have been operating for over two decades in Europe and other sites in Australia.

The liquid stream will be treated at the upgraded effluent treatment plant, aiming for the removal of oil & grease, solids and organic matter, as well as nitrogen and phosphorous. The proposed design will ensure the effluent consent will be met consistently in the next years of operation.

While selecting the technology for the liquid stream treatment, we have prioritised the recovery of water with adequate quality for irrigation, and also a combination of engineered processes and natural processes (lagoons). The aim was to find a balance between energy-intensive processes and natural, passive, systems. The proposed concept provides a robust solution, whilst keeping operation and maintenance costs as low as possible without compromising the treated water quality.

The solid waste, including the DAF reject, the excess sludge and the processing residues will be processed in an anaerobic digester, aiming to produce biogas and bio-fertiliser. There are several possible configurations for the AD process, and we recommend running lab scale tests to obtain more accurate design parameters. The tests would also allow for us to explore the best alternatives to manage nitrogen levels, including process additives, mixed wastes, controlled temperature, etc.

Based on the more financial analysis, it is recommended to proceed to detailed design stage, to both optimise the wastewater treatment plant, and to obtain a higher degree of certainty on the biogas plant approach. The biogas plant as designed in this report has the potential to provide for 100% of Harvey Beefs gas requirements, if bringing waste from other facilities is considered in the matrix.

In short-term, the next steps include the detailed design of the upgraded wastewater treatment plant, based on further sampling results, and preparation of methodology and proposal for lab scale testing.