Is Desalination a Solution to Freshwater Scarcity in Developing Countries?

Abstract

Rapid population growth and urbanization are two main drivers for the over-abstraction of conventional freshwater resources in various parts of the world, which leads to the situation of water scarcity (per capita availability <1000 m3/year). Predictions based on the World Bank projected population data and the FAO AQUASTAT database for freshwater availability show that by 2050, 2 billion people living in 44 countries will likely suffer from water scarcity, of which 95% may live in developing countries. Among these, the countries that will likely be most strongly hit by water scarcity by 2050 are Uganda, Burundi, Nigeria, Somalia, Malawi, Eritrea, Ethiopia, Haiti, Tanzania, Niger, Zimbabwe, Afghanistan, Sudan, and Pakistan. Currently, these countries have not yet established desalination to meet their freshwater demand. However, the current global trend shows that membrane-based desalination technology is finding new outlets for supplying water to meet growing water demand in most of the water-scarce countries. These 14 water-scarce countries will demand an additional desalination capacity of 54 Mm3/day by 2050 in order to meet the standard of current municipal water demand and to compensate for the withdrawal of renewable resources. Case studies from India, China, and South Africa have highlighted that other countries may apply the strategy of using desalinated water for industrial users. Moreover, challenges to the widespread adoption of desalination exist such as expense, significant energy use, the need for specialized staff training, the large carbon footprint of facilities, environmental issues such as greenhouse gas emission (GHGs), chemical discharge, and operational problems such as membrane fouling.

Keywords: desalination; developing countries; population growth; water scarcity.

Figure 1

Global desalination capacity with regards to desalination technology and RO source water [3].

Figure 2

Classification of SWRO desalination plants based on their capacity [3].

Figure 3

Total capacity of SWRO and share of extra-large plants in different regions of the world [3].

Figure 4

Global distribution of operational desalination facilities and capacities (>1000 m³/day) by sector user of produced water [5]. Reprinted with permission from ref. [5], 2019, Elsevier.

Figure 5

Trends of (a) cost in USD/m³ [9] and (b) power consumption in kWh/m³ [10] in seawater reverse osmosis plants.

Figure 6

Countries expected to be water-scarce by 2050.

Figure 7

Country comparison of desalination use in India, Algeria, China, and South Africa [3].

Figure 8

Key desalination market forces [23].

Figure 9

Environmental concerns and sustainable solutions for the desalination plant to minimize the environmental impact [28].