Membranes packed with charge help overcome the current salinity limit, making it easier to crystallize ocean salts and harvest valuable minerals from desalination waste.
Membranes packed with charge help overcome the current salinity limit, making it easier to crystallize ocean salts and harvest valuable minerals from desalination waste.
Desalination plants, a major and growing source of freshwater in dry regions, could produce less harmful waste using electricity and new membranes made at the University of Michigan.
The membranes could help desalination plants minimize or eliminate brine waste produced as a byproduct of turning seawater into drinking water. Today, liquid brine waste is stored in ponds until the water evaporates, leaving behind solid salt or a concentrated brine that can be further processed. But brine needs time to evaporate, providing ample opportunities to contaminate groundwater.
Space is also an issue. For every liter of drinking water produced at the typical desalination plant, 1.5 liters of brine are produced. Over 37 billion gallons of brine waste is produced globally every day, according to a UN study. When space for evaporation ponds is lacking, desalination plants inject the brine underground or dump it into the ocean. Rising salt levels near desalination plants can harm marine ecosystems.
Read more at University of Michigan
Image: David Kitto, a postdoctoral fellow in chemical engineering, inspects a freshly made electrodialysis membrane. Photo credit: Jeremy Little, Michigan Engineering.
