Seawater desalination using membrane processes. Credit: Johnson Effoe Efome
Hooman Chamani is a Ph.D. Candidat in Ottawa. His motivation is to address the global water crisis in a sustainable manner. Although it may seem simple, it was difficult to do until recently.
His work with Dr. Christopher Lan and Professor Takeshi Matsuura of the University of Ottawa's Department of Chemical and Biological Engineering, and their research team Joanne Woloszyn and Dipak Rana has led to the discovery of a commercially viable solution that is both environmentally friendly and improves on current desalinization methods.
Their paper, "Pore Wetting in Membrane Distillation: A Comprehensive Review", was published in the prestigious scientific journal Progress in Materials Science. It identifies commercialized membrane distillation as a green way to produce clean, safe water.
Hooman Chamani, the lead author, says that "with the commercialized membrane distillation at large-scale, we can move towards a solution to the water crisis."
The Blue Planet
Although the Earth's surface is mostly water, natural freshwater availability is very low. It only represents 2.5 percent of the Earth's hydrosphere. The remaining 97.5 percent is contaminated water.
The population is growing and so is the demand for water. This is putting pressure to its limited supply.
Hooman Chamani says that more than two billion people around the globe don't have safe drinking water. Even Canada is blessed with plentiful freshwater resources, there are still areas that have water shortages. Polluting freshwater resources is a result of human activities like urbanization and industrialization. Global water scarcity is also being caused by changes in the weather, a result of global warming over recent decades.
Desalination refers to the removal of salts and minerals from saline water in order to get fresh water.
Christopher Lan, senior author, says that reverse osmosis is the state-of-the art technique for seawater desalination. However, this technique does not have the ability to desalinate salt water or concentrated brines. Membrane distillation is an alternative method of desalination that is more capable of handling highly saline solutions.
Membrane pore wetting
If membrane distillation is the best way to get clean water why haven't more people tried it?
Researchers claim that membrane distillation's biggest drawback is "membrane pores wetting".
Takeshi Matsuura says that membrane distillation could replace reverse osmosis if this problem is solved. We have been working to make membrane distillation more commercially viable by addressing the fundamental issue of pore wetting. We have provided a review of recent developments to stop membrane pores being wetted in the review article.
"In this review, we cover all aspects of pore wetting, which is the most challenging challenge in membrane distillation. This will give you a better understanding of this unfortunate phenomenon using the most advanced knowledge in the field.
Both for the environment and us.
Hooman Chamani says that the reject brine from reverse osmosis can be very concentrated and is a problem for the environment. "So, commercialized membrane distillation can be used to treat highly saline brines. This will not only make it more accessible but also helps manage brines and protect the environment.
It's not an easy task.
Dr. Christopher Lan concludes, "After many years working in this area, our group identified pores wetting as the most critical issue of membrane distillation." "Hooman Chamani challenged the problem and resulted in several high-impact publications. He is one of our best Ph.D. students and has one goal. That's to solve the water crisis through the commercialization of membrane distillation.
Continue reading Making seawater drinkable within minutes
More information: Hooman Chamani et al., Pore wetting in membrane distillation: A comprehensive review. Progress in Materials Science (2021). Hooman Chamani and colleagues, Pore wetting of membrane distillation: An extensive review, (2021). DOI: 10.1016/j.pmatsci.2021.100843
