Turning waste into a valuable "green" commodity

Turning waste into a valuable "green" commodity

Agribusiness
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New technology developed by South Australian scientists has shown how intensive Australian farming and food processing systems can save water, turn waste into a profitable resource and prevent pollution.

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New technology developed by South Australian scientists has shown how intensive Australian farming and food processing systems can save water, turn waste into a profitable resource and prevent pollution.

It is now up to industry to accept the challenge and take on full-scale trials of the SARDI developed method of farming using integrated biosystems – a smart approach to intensive farming that addresses increasingly scarce water resources and environmental pressures while turning greater profits.

Dr Martin Kumar from the South Australian Research and Development Institute (SARDI) says more than ten years of research has 'busted the myth' that agricultural wastewater from intensive farming systems cannot be turned into a valuable and safe resource.

"A key limiter to the future growth of agriculture and industry will be water," says Dr Kumar, who led the five-year $4.3m project with partners University of Adelaide, Murdoch University and the University of NSW. It was funded by the Environmental Biotechnology CRC.

"Our work on integrated biosystems proves the technology can be successfully used to treat organic waste and wastewater on a commercial scale, and that waste can then be turned into a valuable commodity."

The process includes organic waste streams generated by wineries and breweries, poultry, meat and cattle production, aquaculture, horticulture and viticulture, pasture and crop industries and wastewater and sewage treatment plants.

The pork, poultry, feedlot cattle, aquaculture, seafood, grains and wine industries alone generate about 25.735 million tonnes of waste per year with disposal costing around $750 million annually (Econsearch 2007)

Dr Kumar says this loss could be turned around into profitable additional diversified enterprise by using the waste to produce products such as fish and livestock feeds, fertilisers, clean recycled water and biogas.

The idea of using integrated biosystem methods within farming is not new. The natural method uses waste from one process to feed another. Asian farmers in particular have for many years incorporated a more holistic approach to their production methods on a small-scale.

"Our research has taken the integrated biosystems concept to the next level," says Dr Kumar. "We developed a lab scale model to demonstrate the technology and have proved its practical and commercial applicability to the pork, poultry, feedlot cattle, aquaculture, seafood, grains and wine industries."

"Our mesocosm level model also enabled the IBS team to conduct experiments and develop the engineering design of a field scale prototype."

Dr Kumar's recently released report called Commercial Scale Integrated Biosystems for Organic Waste and Wastewater Treatment for the Livestock and Food Processing Industries presents a practical and comprehensive body of knowledge to industry, laying the groundwork for it to take up the challenge and start large scale field trials.

At their disposal is a fully constructed IBS prototype capable of demonstrating at commercial level IBS technology turning animal waste into biogas and recycling nutrients for land-based aquaculture systems. The model can also be used to train industry workers and professional students. Professional engineering drawings for large scale development are also available. There's also an economic analysis covering inputs such as waste production, waste treatment costs and IBS technology adoption rates, as well as a business case to help with decisions about investment in IBS technology.

"We believe that IBS presents a paradigm shift in business models where waste is no longer an expensive cost item but an income producing stream integral to boosting profit," says Dr Kumar.

The aim of the project was to develop an integrated farming system model which prevents organic pollution and enhances productivity and profitability of the farming and food processing industries.

"We were able to apply advances in biotechnology to eliminate pathogens, make nutrients available for algal and fish production, and convert any wastes produced on farms into valuable products. In the process, any water in the system was treated and available for re-use."

Treating organic wastewater

Meat and Livestock Australia (MLA) and the Tatiara Meat Company joined forces with the South Australian Research and Development Institute (SARDI), to develop a process where high-strength wastewater is turned into valuable products.

The project is linked to SARDI's Environmental Biotechnology CRC funded project Commercial Scale Integrated Biosystems for Organic Waste and Wastewater Treatment for the Livestock and Food Processing Industries.

Meat processing wastewater streams, which are expensive to dispose of, are high in nutrients and, if left untreated, are harmful to the environment.

"Wastewater streams are a problem for all processors, not only because of the technical issues, but also the cost of treatment with no financial return," said David Doral, Manager Processing Efficiency and Sustainability at MLA.

"The project demonstrated a potential low-cost solution to a high-cost problem and it could result in a financial return for the meat processing industry," Mr. Doral continued.

MLA began working with the researchers at SARDI towards an alternative way to treat organic wastewater in the project funded by the Environmental Biotechnology CRC. Through a series of stages, microbes digest nutrients in the wastewater, which sterilises and clarifies the water, reducing overall nutrient levels. Nutrients are further reduced by algal growth, which in turn supports zooplankton growth and finally supports the efficient growth of fish. Trials in the multi-pond wastewater treatment system have delivered promising results.

The types of fish that have been successfully grown in the ponds at Tatiara are carp, ornamental gold fish and silver perch.

"The possibilities for this technology are very exciting as the biosystem can be applied to any industry discharging non-toxic waste. MLA's involvement in EBCRC's research and development projects mean that our members will be one of the first to benefit from any commercialisation of these discoveries" Mr Doral said.

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