Plants have been inspiring new ways to extract value from wastewater through a process known as phytoremediation. Phytoremediation is a process that uses plants to remove pollutants from soil, water, and air. This process has been used for many years to clean up contaminated sites and has recently been explored for its potential in wastewater treatment.
The Australian National University (ANU) scientists are using plants as inspiration to develop new techniques for separating and extracting valuable minerals, metals, and nutrients from resource-rich wastewater.
The ANU researchers are modifying plant’ membrane separation mechanisms’ so that they can be incorporated into new wastewater recycling technologies. This approach provides a sustainable solution for managing the resources needed for the world’s food, energy, and water security by harvesting, recycling, and reusing valuable metal, mineral, and nutrient resources from liquid wastes.
Agriculture, aquaculture, desalination, battery recycling, and mining could all benefit from the technology. It could also assist businesses in rethinking their waste management strategies by developing a method to extract value from wastewater. The study has implications for flood and drought-prone areas throughout Australia.
The world’s wastewater contains a jumbled mess of extremely valuable resources, but only in their pure form. One of the biggest challenges for researchers is figuring out how to extract these valuable minerals, metals, and nutrients while retaining their purity.
Associate Professor Caitlin Byrt
Global wastewater contains three million metric tonnes of phosphorus, 16.6 million metric tonnes of nitrogen, and 6.3 million metric tonnes of potassium, according to estimates. The recovery of these nutrients from wastewater has the potential to offset 13.4% of global agricultural demand for these resources.
The ammonia and hydrogen molecules, among others, that are embedded in wastewater could provide electricity to 158 million households.
“The world’s wastewater contains a jumbled mess of extremely valuable resources, but only in their pure form. One of the biggest challenges for researchers is figuring out how to extract these valuable minerals, metals, and nutrients while retaining their purity,” said ANU plant scientist Associate Professor Caitlin Byrt.
“For example, the Australian mining industry generates over 500 million tonnes of waste per year, and these wastes are rich in resources such as copper, lithium, and iron.” But, for the time being, liquid waste is just a problem; it cannot be dumped and cannot be used. Unless each resource can be separated out in its purest form, it is just waste.”
“This is especially true in the battery recycling industry; we have a huge, rich source of lithium inside dead batteries, but we can’t yet extract or reuse it efficiently. Harvesting resources from industrial and urban waste is an important step toward transitioning to a circular green economy, creating a sustainable future, and lowering our carbon footprint.”
The researchers looked into the specialized molecular mechanisms that help plants recognize and separate different metal, mineral, and nutrient molecules in soil, allowing them to separate the good from the bad – an important biological process for their growth and development.
“Battery technologies use resources such as boron, iron, lithium, and phosphorus, and plants are masters at separating these types of resources,” Associate Professor Byrt explained.
Another key resource scientists are looking to extract from liquid waste solutions is ammonia, a compound used to make fertilizer and an essential material in crop production.
“Fertiliser costs are skyrocketing, putting a lot of pressure on Australian farmers to be able to afford these higher prices, and yet we’re wasting huge proportions of these molecules, which is causing environmental problems,” Associate Professor Byrt explained.
“Ammonia is also an important storage molecule for hydrogen fuels. As we continue to develop hydrogen fuel industries, there will be an increase in demand for ammonia for use as a storage molecule, because that is how the hydrogen fuel industry will be able to transport the stored hydrogen around and eventually use it as a potential fuel source for fueling cars and other technologies.”
According to Associate Professor Byrt, advances in precision separation technology could provide security to flood- and drought-prone communities across Australia by providing portable, secure, and dependable access to clean drinking water in the face of worsening weather events caused by climate change.
