Scientists develop plant-powered desalination technology - allows land reclamation
Global agriculture utilizes large amounts of fresh water. But continued cropping and irrigation can turn land gradually into a salt pan, making agriculture impossible over time. The problem of soil salinization is universal and few practical solutions currently exist. In the meantime, water is becoming a scarce resource. Making fresh water out of salt water is possible with desalination technologies, but these require large inputs of (fossil) energy.
A new technology has now been developed that succeeds in desalinating the salt water from agricultural land, without relying on external energy sources. Instead, the technology utilizes the power of plant roots.
Associate Professor Greg Leslie, a chemical engineer at UNSW's UNESCO Centre for Membrane Science and Technology, is working with the University of Sydney on the technology which uses reverse-osmosis membranes to turn previously useless, brackish groundwater into a valuable agricultural resource.
The team is looking at ways to grow plants on very salty water while restoring the soil. The key of the system can be found in the incorportation of a reverse osmosis membrane into a sub-surface drip irrigation system. The irrigation system relies on the roots of the plant drawing salty groundwater through the membrane – in doing so removing the salt which would otherwise degrade the soil and make continued cropping unsustainable.
Desalination such as this requires a pressure gradient to draw clean water through the membrane. Professor Leslie has demonstrated that, by running irrigation lines under the ground beneath the plants, the root systems of the plants provide enough of a pressure gradient to draw up water without the high energy consumption usually required for desalination:
energy :: sustainability :: biomass :: bioenergy :: agriculture :: irrigation :: soil salinization :: desalinization :: reverse osmosis :: land reclamation ::
The scientists think the technology will make it possible to provide agriculture with a new tool to grow crops in drought years when there is limited access to run-off and surface water.
The plant-powered desalination technique could also make the reclamation of salinated soils viable, thus expanding the land resource that is available for agriculture.
The membrane technology, developed by Professor Leslie and the University of Sydney's Professor Bruce Sutton, has been patented by UNSW's commercial arm, NewSouth Innovations.
Image: plant roots provide enough pressure to make desalination via reverse osmosis work.
References:
UNESCO Centre for Membrane Science and Technology, University of New South Wales.
NewSouth Innovations.
0 Comments:
Post a Comment
Links to this post:
Create a Link
<< Home