Wastewater-treatment for inland, remote, water-stressed regions
Game-changing water treatment solutions can treat water from mining and other industrial operations so that it can be either re-used within their industrial operations, recycled to nearby water-stressed regional communities or safely discharged to the environment.
“Tertiary-level water treatment can turn water from a scarce single use resource with ongoing demand into a sustainable reusable resource,” says CSIRO’s Dr Ramesh Thiruvenkatachari.
But it comes at a cost.
“This level of treatment is generally infrastructure intensive and uses a lot of chemicals and energy,” says Dr Thiruvenkatachari.
Turning wastewater into a reusable resource
CSIRO is investigating a range of innovative solutions to treat wastewater. These includes methods that can harness renewable energy to recycle wastewater on site in remote areas.
Designed as compact, modular and containerised systems, the units include unique membrane-based processes with a range of technologies customised to suit the needs of each situation.
“We don’t try to develop one solution and then fit an off-the-shelf technology to different sites. The solution starts at the end by working out what the water requirements are,” Dr Thiruvenkatachari says.
“We then develop technologies to match the characteristics of the feed or source water so we can customise a solution with minimum energy, environmental and infrastructure footprint.”
Improving water access for remote communities
As the planet’s human population approaches eight billion, potable water is becoming a precious resource.
A quarter of the world’s population live in water-stressed regions which face threats to drinking water supplies. This includes regional towns and remote communities around Australia.
Parts of the dry Australian continent experience such low annual rainfall that seventy per cent of the land mass is classified arid or semi-arid.
Much of the fresh water used in regional and remote communities comes from surface water, particularly rivers, and from bores which tap into ground water aquifers.
But aquifers like the Great Artesian Basin are under pressure balancing competing industrial water use requirements.
Treating and reusing wastewater from industry
Working on industrial wastewater remediation and recovery, the team are now expanding their focus in using similar and complementary technologies to help water-stressed remote communities improve the quality of the water they are extracting from groundwater sources.
Principle Consultant, Graham O’Brien, has been involved in exploring potential partnerships with remote communities where this CSIRO-developed water treatment design could be trialed.
“The scalable and portable nature of this technology is ideal for deployment in remote communities of different population sizes that rely on bore water,” says O’Brien.
Some of the communities relying on bore water also face other issues relating to its high mineral content.
A study underway at the Menzies School of Health Research in Darwin is exploring the potential health impacts of highly mineralised water.
The Northern Territory town of Wugulurr (also known as Beswick) around 120 kilometres south-east of Katherine, has to deal with water characteristics that impact the available infrastructure.
Process to produce potable water
Trials of the CSIRO technology are under discussion with Indigenous training organisations in North Queensland near Townsville.
“We start by analysing the samples of water. This helps us understand the characteristics of the water. It tells us the issues at specific locations we need to address to deliver potable water to the community,” says Dr Thiruvenkatachari.
He says the solutions can be scaled to cater for local community demand.
“For example, one unit could deliver 10,000 litres of potable water a day. For a community of 200 people your goal would be providing around 150 litres a day per person so you would scale up accordingly.”
“Energy efficiency of the water treatment system is very important. We also look to integrate suitable site-specific renewable energy source options where possible,” says Dr Thiruvenkatachari.
Water treatment for industrial and agricultural needs
Water scarcity is exacerbated by increasing threats from extreme weather events and climate change. These factors also increase potential risks from mining and industry.
While Australia has ongoing regulatory and water market mechanisms that direct the distribution of water in areas where water access is limited, better water treatment and recycling in industry is also an urgent priority.
Water is an integral part of the operations of mining and other industries. Australia has strong environmental protections that prevent untreated wastewater from mining and industry being discharged into waterways.
Solutions developed by the CSIRO project team include the segregation of different qualities of water to enable greater water recycling.
During periods of heavy rainfall, the build-up of water on a mining or industrial site can occur at a faster rate than the discharge.
Improved efficiency of on-site water treatment technologies is critical to reduce the storage levels of mining and industrial wastewater.
A solution that can also minimise the risk of wet season run-offs and freshwater contamination is one way to mitigate increased climate-related risks.
CSIRO researchers are working closely with the mining industry to develop better wastewater treatment techniques at a larger scale for these remote sites so water can be reused or safely released into the environment.
Where mining sites are located near communities, O’Brien says, there can also be some synergies where water recovered from mining may be used for “beneficial purposes in communities”.
“Sometimes the industrial wastewater can be beneficially used in agricultural irrigation – depending on its characteristics,” says O’Brien.
Tamworth water reuse trial
A trial is currently underway in Tamworth, in north-west NSW, using a forward-reverse osmosis process to treat wastewater from abattoirs.
This approach provides a double barrier to remove pathogens and recover reusable water for other applications.
“Our solution helps industry safely meet the discharge requirements of wastewater,” says Dr Thiruvenkatachari.
“It also facilitates more efficient, low-cost recovery of usable water for other beneficial purposes within the industry operation and in the wider environment.”
Contact Ramesh.Thiruvenkatachari@csiro.au for more information.