Making Seawater Safe to Use? Algeria’s Desalination Success.

Desalination is a revolutionary way to increase water and food security for struggling countries; however, is it a reasonable solution? In this entry, I will focus on the role of desalination in Algeria to address its water scarcity issue, which has dramatically impacted its agribusiness. I will explore what desalination is, how Algeria has capitalised on this technology and its limitations. 

 

In last week’s blog, I elaborated on the potentials of water transfer projects like the GMMR in increasing water and food security. In essence, projects like the GMMR transport water from areas of surplus to those in deficit. However, a limitation of schemes like the GMMR is that a country must have a surplus of water that they can transport, which is not always the case (Salem 2007). Therefore, rather than relying on water from areas of surplus, using a process known as ‘desalination’, water can, in essence, be created. This process can prove incredibly useful for water-scarce nations like those in MENA, enabling them to self-sustain food and water supplies (Iglesias et al. 2007; Krysanova et al. 2010). Therefore, could desalination be a solution to Africa’s uneven water and food supply? 

 

Desalination in Algeria:

As expected with North Africa, Algeria suffers from water scarcity owning to its intense heat and seasonal rainfall (Sadi and Kehal 2002). Even though the country is located on large transboundary aquifers, exploiting them proves unsustainable, similar to Libya’s case (Quadri 2019). Drouiche et al. (2011: 2745) stated that in Algeria “groundwater has already reached its limit, leading to higher pumping rates”. Therefore, if Algeria continues to exploit groundwater, aquifer levels will remain low as recharge is highly uneven (Ibid 2019). Henceforth, for Algeria, utilising desalination has been a lifeline to increase water supplies. As of 2011, Algeria had 15 seawater desalination plants with a total capacity of 2.3 million m³/day, making it the 6^th largest desalinising nation globally (fig. 9) (Hamiche et al. 2018). For Algeria’s growing agriculture industry, desalination has also proved as an excellent tool for supporting irrigation, especially during periods of low rainfall and high temperatures (Mitiche et al. 2010). Through desalination, Algeria has been able to significantly increase food production, with 25% of its economy being reliant on agriculture (FAO 2018).Likewise, Algeria has capitalised on cash crops like watermelons, olives and grapes, which the country would have been incapable of doing without desalination. However, Algeria continues to import approximately 45% of its food, despite having an abundance of desalination technologies (Ferrah et al. 2013). This low figure arguably is because only 4% of its land has been cultivated. Henceforth, for Algeria utilising its desalination technology should be their utmost priority to expand cultivated land and support its domestic agriculture industry. 

Fig. 9: Desalination capacity by country (Hamiche et al. 2018).

How does desalination work?

I speak of 'desalination'; however, what is it? In essence, 'desalination' is the process of removing mineral components from saline water, making it safe for consumption. There are various desalination processes; however, they can be broadly divided into 'membrane-based' and 'distillation-based' (El-Dessouky and Ettouney 2002). The most common methods are, however, reserve osmosis and thermal distillation. In short, reserve osmosis works by passing water through pressurised semipermeable membranes which induce water permeation whilst separating salts (Ibid 2002).Thermal distillation works by heating saline water and condensing its water vapour on a cold surface, creating safe water free of salts (Ibid 2002). The video below explains desalination incredibly well. 

So, in essence, utilising desalination can make saline water safe to consume. So, there must be drawbacks. Right? Here are a few:

 

Drawbacks:

- Costly technology, meaning not all countries can utilise desalination. 

- Reliant on access to large bodies of water like seas, limiting its use for landlocked regions.

- Large amounts of energy is needed, which are reliant on fossil fuels.

- The by-product of desalination; ‘brine’ can have disastrous environmental impacts if improperly discarded given its salt concentration (Jones 1997).

 

In conclusion, desalination has been a valuable tool for some water-scarce countries to increase water and food access. This blog entry explored how Algeria has been able to support its agricultural industry through desalination. However, it remains clear that desalination's full potential is still not recognised in nations like Algeria. Likewise, desalination remains a tool only for those with the capital and access to large water bodies.