Water Journal : Water Journal August 2014
WATER AUGUST 2014 90 Water Business and nutrient (N, P and organic matter) recovery approaches and technologies. Participants visited City Food Growers' urban farm and urban farming training centre in Samford, Brisbane, and discussed how stormwater, rainwater and recycled wastewater might play a role in supplying the farm as it grows. They also visited Wynnum WWTP to see how water recycling technology can play an important role in taking heavy industrial water users off the grid by supplying them with water recycled from municipal wastewater. At the plant, participants learned about the process technologies involved, including the MFRO plant, and discussed the opportunities at different scales for using water recycling in engineering and commercial terms, and how to cost- effectively recover and reuse biosolids and recovered P in the form of struvite. IWC's Master of Integrated Water Management offers the Urban Metabolism: Resource and Energy Recovery Systems module as part of its Urban Water specialisation stream. Viewing urban areas as systems that 'metabolise' resource inputs, ultimately releasing them back to the environment as wastes, this module challenges current patterns of water, energy and nutrient use in cities as inefficient and unsustainable. Emphasis is placed on water, with coverage of technologies and management approaches to manipulate water flow in urban systems to improve 'metabolism' by reducing raw water intake and recovering and using the resources that wastewater carries, particularly energy, nitrogen and phosphorous. The module equips participants to critically assess the resource ef ciency and sustainability of urban systems from household through development to whole city scales, to systematically quantify physical ows in complex urban systems, and to construct and use urban metabolism models to characterise and evaluate options for improving urban sustainability. The module is delivered by Dr Steven Pratt, IWC Senior Lecturer in Integrated Water Cycle Engineering at The University of Queensland (UQ) School of Chemical Engineering, Dr Steven Kenway, Water- Energy-Carbon Research Group Leader at UQ Advanced Water Management Centre, and Dr Brian S McIntosh, Senior Lecturer in Integrated Water Management at IWC. For more information about the Master of Integrated Water Management please visit IWC's website: www.watercentre. org/education/programs. Full-tuition scholarships are currently available with applications closing on 1 October for domestic students. TURNING MINING WASTEWATER INTO RAINWATER A new cost-effective technology to treat mining wastewater and reduce sludge by up to 90 per cent has been used for the rst time at a commercial mine. The technology, called Virtual Curtain, was used to remove metal contaminants from wastewater at a Queensland mine and the equivalent of around 20 Olympic swimming pools of rainwater-quality water was safely discharged. Sludge is a semi-solid by-product of wastewater treatment and reducing the amount produced has huge environmental and economic bene ts. "Our treatment produced only a fraction of the sludge that a conventional lime- based method would have and allowed the mine water to be treated in a more environmentally sound way," CSIRO scientist Dr Grant Douglas said. "Reducing the amount of sludge is bene cial because the costly and timely steps involved to move and dispose it can be reduced." Given the Australian mining industry is estimated to generate hundreds of millions of tonnes of wastewater each year, the technology opens a signi cant opportunity for companies to improve water management practices and be more sustainable. "The technology can produce a material high in metal value, which can be reprocessed to increase a miner's overall recovery rate and partially offset treatment costs," Dr Douglas said. Virtual Curtain utilises hydrotalcites, which are minerals sometimes found in stomach antacids, to simultaneously trap a variety of contaminants, including arsenic, cadmium, and iron, in one step. Dr Douglas and his team developed the technology after discovering that hydrotalcites could be formed by adjusting the concentrations of common wastewater contaminants, aluminium and magnesium, to an ideal ratio and then by increasing the pH. "By using contaminants already present in the wastewater we have avoided the need for expensive infrastructure and complicated chemistry to treat the waste," he said. "If required, the treated water can be puri ed much more ef ciently via reverse osmosis and either released to the environment or recycled back into the plant, so it has huge bene ts for mining operators in arid regions such as Australia and Chile. "It is a more ef cient and economic way to treat wastewater and is enabling the global mining industry to reduce its environmental footprint and extract wealth from waste." The licensed technology, which can be applied to a range of industrial applications, is available through Australian company Virtual Curtain Limited.
Water Journal September 2014
Water Journal June 2014