Treating for water pollutants

• Emerging pollutants - what we're finding and why we're only detecting them now.
• Identifying appropriate treatment technologies for these emerging pollutants.
• Creating a centralised resource for water treatment technologies and the downstream effect this could have on the water sector.

‍

What we know about the water we drink is changing.

New detection technologies and a deeper understanding of public health means we’re becoming aware of contaminants in our water systems we didn’t know about before. Some of these are relatively new chemicals like pharmaceuticals. Others, like the poly-fluoroalkyl substances (PFASs) contained in fire-fighting foams, have been used for half a century.  

‍

Gabby Butera and a cross-disciplinary team of engineers from Australia and the UK are looking for ways to identify, treat and remove these pollutant as early as possible.

There are three main reasons a pollutant could be categorised as emerging.  

‍

The first is that we might not have been able to be detect that pollutant until recently. As the water industry continues to employ more robust monitoring technologies. This is a trends we observed in another research project explored in this publication, Digital Tide. It’s likely that we’ll only detect more things within our water, more often. 

‍

The second reason is that these pollutants might be new compounds all together—new building materials or pesticides, for example. 

‍

The final reason is that something we’ve known to be present in our water for quite some time might only recently have become categorised as hazardous.

“What’s surprising is that there’s research that identifies the potential health hazards of a contaminant dating back to the late 80s,” says Gabby, an engineer in our Melbourne water team. “But it’s only come to the forefront in the past few years due to a class action around contaminated water supplies in Australia or the US.”

Gabby and her team have singled out 10 of the most pressing of these emerging pollutant and drawn up a list of technologies that exist to treat them. Some of these treatment technologies are commercially available. Others are currently being researched in the lab. The team grouped contaminants by category in order to highlight technologies that are able to treat more than one at once.

Resilient Resources

“Often the most effective treatment solutions are those that are tried and true,” Gabby says. The problem is that many of these traditional methods are imperfect. Granular activated carbon creates too much waste, for example, and reserve osmosis requires a tremendous amount of energy. Filtration processes often create a waste stream that has to be treated again, in kind. 

‍

By identifying new or alternative solutions, Gabby hopes this research will prompt conversations around the water sector about how we deal with emerging pollutants. She also hopes this work will be useful as a go-to reference for people trying to deal with a particular contaminant in their water infrastructure and inspire more people to create holistic resources around water treatment.

While a number of water treatment technologies exist commercially, very little of this knowledge exists in a centralised location.

“There’s a lot of specialised knowledge but no one seems to have a full view of what’s available across emerging contaminants generally,” says Gabby. “I think there’s a lot of value in being able to educate people holistically.”

Gabby and her team members delivered this research at conferences in Leeds, UK and Cape Town, South Africa and will present the findings in Brisbane at OzWater in an attempt to broaden these conversations. In December 2017, the project was granted the Research Innovation Award at Victorian Water Awards, presented by the Australian Water Association. “We’re now talking to one of the water authorities to progress this.” Gabby says. “How can we better understand this space?”

• We identified 10 emerging pollutant in global water supplies and appropriate treatment technologies.
• We need to consider all inputs and output streams when considering a treatment technology. Sometimes the byproducts of a treatment technology can be as hazardous as the initial contaminate being treated.