The Problems with Water Desalination

The average life expectancy of people without water can not exceed 3 days. Many of the world 's freshwater sources are dry or polluted, especially in developing countries where many people can not access safe drinking water. It is only 2.5% of the earth's water that is freshwater, and less than 1% of people can enter (it is not restrained by the ice sheet). It is estimated that one percent of the Earth's water supply is over 7 billion people, and for perfect health it is 6 liters per day, all the water necessary for agriculture and industry is needed.

The problem is that we need a lot of energy for water desalination. Salt is easy to dissolve in water and forms a strong chemical bond which is not easily broken. Both energy technology and desalination water technology are expensive. In other words, desalination water can be very expensive. Depending on personnel and energy costs, land prices, financial agreements, and even salinity of water, this number varies greatly from place to place. Producing 1 cubic meter (264 gallons) of desalinated water from the ocean may cost more than $ 2 for less than $ 1. About two people stay in the house one day in the United States.

It looks very simple. If 97% of the water on the earth is salt water, dilute it. The problem was solved. Currently there are 18,426 seawater desalination plants in 150 countries. More than 300 million people depend on this water to meet their daily needs. In countries like South Africa where the coastline is 2,500 kilometers, this answer is particularly evident. Indeed, in the past few years, many local governments have discussed seawater desalination strategies. As desalination requires a lot of energy, in most cases, a huge amount of carbon dioxide emissions is required. So, do you use biofuel? Well, in this case, it may be even worse. It takes 1000-4000 liters of fresh water to produce only 1 liter of biofuel. We know the water we do not have. Secondly, this is an expensive astronomical figure. The cost of seawater desalination is 2 to 3 times of other water reuse methods such as rainwater use and waste water recycling.