• Julissa Coplin

Desalination: Its Potential to End the Global Water Crisis

Introduction

Water scarcity has become an increasingly pressing issue in today’s world. Specifically in the United States, from the drought of the Colorado River to the Water crisis in Jackson, Mississippi, Water scarcity is a growing threat to humanity and all life forms that depend on Water.


Water scarcity can be defined as a condition in which the “demand for Water by all sectors, including the environment, cannot be satisfied fully due to the impact of Water use on supply or quality of Water” (Liu et al., 2017). The “Water use to availability ratio” is among a number of common indicators used to assess national Water scarcity levels (Liu et al., 2017). Only about three percent of Water on Earth is fresh Water, and one percent of that is available for use as drinking Water (Sharghi, 2014). These numbers, however, are dwindling, as the consequences of climate change bring about more record-breaking droughts and other climate-related threats that jeopardize our drinking Water. Another crucial component of Water scarcity is the distribution of clean drinking Water to residents. The distribution of Water resources must occur without presence of discrimination of any kind in order to align with Water justice and Water equity goals.


Technology is an essential component in solving the global Water crisis. One process in particular, called desalination, is a technique that turns salt Water into fresh Water that is safe for human consumption. Reverse osmosis is a common method of desalination that uses a semi-permeable membrane to filter out salt brine and other contaminants (USGS, 2019). While desalination is not exactly a new technological advancement, newer and more efficient desalination plants have been constructed to generate fresh Water for cities in arid and drought-frequent regions, such as the SWANA region (South West Asian and North African). There is ongoing debate on the feasibility of desalination to become the solution to Water scarcity around the world, as more regions become drought-ridden and are looking to turn to other reliable sources of drinking Water. This article will examine the degree to which desalination is a practical and attainable solution to drought and Water stress/scarcity and assess its limitations.


The Pros and Cons of Desalination

Desalination’s capability of being a global solution to Water scarcity requires a closer look at the advantages and disadvantages of the process from an environmental and economic perspective.


A major strength of desalination is that it produces reliable, high-quality, and safe drinking Water (Pacific Institute, 2006). It is wholly effective in removing harmful impurities and is comparable to the quality of existing Water sources. However, ocean Water in desalination plants has the potential to introduce “biological contaminants”, such as “viruses, protozoa, bacteria”, and unregulated contaminants that are hazardous to human health (Pacific Institute, 2006). This risk requires that there is high-level regulation and monitoring of large desalination plants to ensure desalinated Water is safe for drinking.


There are also environmental challenges that come with the process of desalination. A method for the proper disposal of salt brine from the desalinated Water is an ongoing debate. Salt brine is a byproduct of desalinated Water and is highly concentrated with salt and other contaminants. Often, salt brine is returned back to the ocean, which severely disrupts the marine environment (Pacifica Institute, 2006). In addition, most desalination plants today rely on thermal energy, which is a non-renewable source of energy that relies on coal and other fossil fuels, which would not contribute to the global effort in reducing the consequences of climate change (Pacific Institute, 2006). Impingement and entrainment, which is when fish and other wildlife get stuck in the desalination plant as large quantities of Water enter the system, also poses a danger to marine life (Pacifica Institute, 2006). In order to prevent all these environmental concerns, heavy daily monitoring and regulation of desalination plants is required.


Another area of concern with desalination technology is the higher cost of desalination plant maintenance and energy usage. According to the Pacific Institute (2006), “energy is the largest single variable cost for a desalination plant, varying from one-third to more than one-half the cost of produced Water”. As these facilities are energy intensive, plants are built in locations where cost-effectiveness is feasible. Due to high costs, other locations opt to invest in cheaper methods of supplying Water that produce the same quality.


This, consequently, segues into another strength of desalination, which is the abundance of research currently happening to explore cleaner, cheaper, and more energy efficient methods of desalination (Pacifica Institute, 2006). The current rate of the advancement of desalination technology is “sufficiently mature”, which demonstrates a promising future for the global status of desalination (Pacifica Institute, 2006).


Lastly, an important advantage that desalination has over other Water supply options is that it’s incredibly stable and is a definitive source of Water that is not impacted by drought, rainfall, natural hazards, or other environmental factors. While current sources of Water, such as rivers and streams, can be jeopardized by drought and Water contamination, sea Water is the only Water needed in desalination to produce high-quality, safe, and clean drinking Water. Desalination is a process to consider for nations like the United States, which experienced an unprecedented drought of the Colorado Rivers and other essential bodies of fresh Water that serve as sources of drinking Water. Overall, while there are cons that need careful attention and stern regulation, there are promising advantages to desalination technology that makes it a good candidate for expanded use in the future.


Case Study: GCC Countries and Current Use of Desalination

The Gulf Cooperation Council (GCC) is a regional union consisting of 6 countries: Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates. The GCC is the largest region of the world that depends on desalinated Water due to their fresh Water sources being insufficient to fulfill regional demand. As of 2013, there was a global figure of 17,346 contracted desalination plants. 7,499 – 43 percent of all desalination plants – were located in the GCC region (Moossa, 2022).


The GCC has faced both successes and challenges in their reliance on desalination for fresh drinking Water. Many of the challenges have already been outlined previously; however, Moossa et al. (2022) places increased emphasis and concern on the long-term environmental impacts of reliance on desalination technology as a Water source.


The GCC recognizes the high reliability of desalinated Water to produce high quality and safe drinking Water for all residents. For instance, the daily average desalination capacity for desalination plants in Kuwait is 1.89 million m3 for a population of 4.27 million people (Moossa et al., 2022). Desalination produces such a sheer quantity of Water that supports entire nations, showing just how dependable and well-grounded desalination technologies are in the GCC region. However, a pressing issue is how to properly dispose of salt brine, as mentioned earlier. More specifically, salt brine cannot be returned back to the ocean, as standardly done, as it can “affect the saline levels, alkaline nature, and the temperatures of the sea Water while also [causing] harm to the marine organisms, the flora, and the fauna” (Moossa et al., 2022). Over 72.2 million m3 of salt brine is produced by Kuwait, UAE, Saudi Arabia, and Qatar each day (Moossa et al., 2022). To prevent damage to marine ecosystems and marine life, GCC countries are actively discussing alternatives to properly dispose of salt brine discharge.


In addition, energy consumption of desalination plants is of great concern. An increased reliance on desalination plants will inevitably create an increased reliance on fossil fuels. As a result, progress is being made in research of other alternative methods of desalination that are less energy-intensive or can be done through renewable and cleaner sources of energy, such as forward osmosis (FO), adsorption desalination (AD), sea Water greenhouse, or membrane desalination (Moossa et al., 2022).

The GCC region is a key example of a success story in providing clean drinking Water for their nations. Despite the work and research needed to be done to reduce the environmental impact and high energy costs, desalination is a viable and attainable option for nations to consider.


The Worldwide Status of Desalination Feasibility

More parts of the world are moving to desalination as one of their reliable sources of clean drinking Water. Since 2010, “the global installed desalination capacity has been increasing steadily at the rate of about 7 [percent] per annum… to the end of the year 2019” (Eke et al., 2020). It is evident that more nations are open to embracing desalination technology and are willing to further invest in it for the future. Also, there has been tremendous progress in “desalting Water affordably”, making desalination a more attainable source of Water as the costs go down (Eke et al., 2020). Given the accelerating rate of climate change and the dire consequences that stem from this, there is a rising “global demand for cost-effective clean Water production” in arid and/or water stressed cities (Eke et al., 2020).


In less affected regions like parts of Africa and Europe, where Water stress/scarcity is not of the most immediate concern, there has been an increase of over 1600 percent and 1700 percent (respectively) in desalination capacity “over the last three decades” (Eke et al., 2020). This demonstrates the need for more regions to adapt to a future with less clean drinking Water from natural resources like rivers and streams. With the ever growing presence of desalination technologies in many regions, one can predict the rise of desalination in countries like the United States, where drought and Water scarcity become more of a threat.


Conclusion

While desalination is a promising alternative to other fresh Water sources, there is still much work to do to make desalination the best solution for Water scarcity/Water stress issues. With the right research and right investments made in advancing these technologies to make them energy-efficient and less expensive, this method has the potential to reduce global instances of Water scarcity. Desalination has the potential to ensure everyone, regardless of geographic location or socio-economic status, is guaranteed access to clean and safe drinking Water. Nations must also ensure that the desalinated Water is equally and fairly distributed among residents, with no presence of discrimination.


Water& recognizes both the advantages and limitations of desalination technology. In a world where Water crises are far too common, exploring other Water supply options is one of the action steps we can take to secure the future of Water and achieve Water equity.


References

Cooley, H., Gleick, P.H., & Wolff, G. (2006). Desalination, with a grain of salt. A California perspective. Pacific Institute for Studies in Development, Environment, and Security.

https://pacinst.org/wp-content/uploads/2015/01/desalination-grain-of-salt.pdf


Eke, J., Yusuf, A., Giwa, A., & Sodiq, A. (2020). The global status of desalination: An assessment of current desalination technologies, plants and capacity. Desalination, 495, doi:10.1016/j.desal.2020.114633

https://www.sciencedirect.com/science/article/pii/S0011916420313114?via%3Dihub


Liu, J., et al. (2017).Water scarcity assessments in the past, present, and future. Earth’s Future, 5(6), 545-559, doi:10.1002/2016EF000518

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016EF000518


Moossa B., et al. (2022). Desalination in the GCC countries - a review. Journal of Cleaner Production, 357, doi:10.1016/j.jclepro.2022.131717

https://www.sciencedirect.com/science/article/pii/S0959652622013300?via%3Dihub


Sharghi, Kayvon (2014). The three percent. NASA Scientific Visualization Studio. Accessed 14 Sept. 2022. https://education.nationalgeographic.org/resource/earths-fresh-water


United States Geological Survey Water Science School (2019). Desalination. United States Geological Survey (USGS). Accessed 14 Sept. 2022.

https://www.usgs.gov/special-topics/water-science-school/science/desalination#overview



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