By Thalia Garman
Due to the increased need for freshwater as our world population grows, new technologies in water treatment have allowed for efficient, cost-saving advancements to treat brine, a hyper-saline solution usually created due to the desalination process. Desalination is a process where dissolved mineral salts in water are removed. When salts are extracted from water, the minerals and salts that were concentrated in the water are left over after the saline water is evaporated, leaving behind brine. What makes brine so hard to manage is the amount of energy that is put into separating the water and the salt, as salt dissolves easily in water, thus requiring more energy to break their kinetic bond. This, in turn, also means that the process involves a state change, as the water is transformed into a gas through evaporation, also requiring large amounts of energy.
With high recovery costs, there may be other solutions that utilize less energy and are more efficient, and that treatment is electrodialytic crystallization. The process of electrodialytic crystallization aims to mitigate the amount of evaporation created during crystallization, limiting the amount of energy that is spent on phase changes. Typically, the process of brine extraction, or the removal of salts and minerals from the water needed, involves using water evaporation from heated-up water to separate the two. When the water is evaporated, the salts are left to crystallize. With this new process of electrodialytic crystallization, water evaporation is unneeded and would save energy from withholding a phase change.
For water to be considered freshwater, it must be measured at a level of under 1000 ppm (parts per million). The ocean is at a concentration of around 35,000 ppm, and brine, which is typically a concentration of water in amounts between 3.5% to around 26%, tends to be left in large amounts after desalination. Due to the large amount of salt and mineral concentration, it becomes difficult to turn heavily salted water into freshwater and creates more brine than water from a residential or commercial area. When it comes to dealing with industrial wastewater, large amounts of water are dealt with at a time containing numerous contaminants, and the process of electrodialytic crystallization could be useful in this field to assist with efficient purification.
These transforming evolutions in processes for treating wastewater have opened the doors to new opportunities for energy-efficient methods and even ways for consumers to save money. Electrodialytic crystallization could be a fascinating way to face desalination and brine concentration.
Citations
https://www.sciencedaily.com/releases/2023/06/230621121027.htm
https://www.usgs.gov/special-topics/water-science-school/science/desalination