As the water crisis deepens around us and it becomes increasingly necessary to find new ways of operating that protect the environment and safeguard resources for the future, research is now ongoing to identify more effective ways of treating wastewater.
A new collaboration between experts at Rice University and Guangdong University of Technology has found that dialysis technology similar to what is used in healthcare settings to treat kidney failure can treat high-salinity organic wastewaters, which contain elevated salt and organic concentrations.
With medical dialysis, a machine is used to filter waste and excess fluid from the blood, cleaning it before it’s returned to the body via a separate tube or needle.
The new study, published in the Nature Water journal, found that replicating this process enabled the separation of salts from organic substances with minimal dilution of wastewater, a way of working that could potentially reduce environmental impacts, reduce costs and ensure that valuable resources are recovered across various different industries.
This is important given the fact that there are many sectors that produce high-salinity organic wastewater, including textile manufacturing, petrochemicals and pharmaceuticals. Existing treatment processes currently struggle to treat these waters, thanks to the combined high salt and high organic content.
For example, thermal methods are energy intensive and prone to clogging and corrosion, while biological treatments can be compromised by higher salinity levels.
But dialysis was effective at removing salt from water without having to use large amounts of freshwater to get the job done. Salts were able to move into the dialysate stream while keeping the majority of the organic compounds in the original solution.
Co-author of the study Menachem Elimelech commented on the findings, describing it as an exciting discovery, one that has the potential to redefine how difficult wastewater challenges are addressed.
He went on to say: “We found that one of the biggest advantages of dialysis for wastewater treatment is the potential for resource recovery. Beyond simply treating the wastewater, we can recover valuable salts or chemicals, contributing to a more circular economy.
“Dialysis offers a sustainable solution for treating complex high-salinity wastestreams by conserving freshwater, reducing energy costs and minimising fouling. Its diffusion-driven approach could revolutionise the treatment of some of the most challenging industrial wastewaters.”
Water quality and wastewater
Adopting a circular economy approach will help ensure that natural environments are afforded proper protection in the face of growing global populations and increased water demand. This will naturally involve improving how wastewater is managed and producing less pollution.
Industry is one of the biggest water polluters out there, affecting both groundwater and surface water – but safely reused wastewater can prove particularly beneficial as a source of sustainable and affordable water, as well as energy, nutrients and other materials.
By increasing wastewater recycling, water quality and supply can be made more resilient, as well as driving progress in public health, economic development and environmental sustainability.
