14 DAY TRIAL // The predictions regarding the evolution of population growth suggest that by the year 2025 more than 3.5 billion people living in different areas on the globe will suffer from severe fresh water shortages. The challenge is now to find an environmental solution, to make fresh water by removing the salt out of seawater.
In the following years, the fresh water may become a very expensive commodity, due to the climate changes, desertification and the ever growing number of people. A research presented by the Trombay Symposium on Desalination of Water Reuse proposes a radical new solution to the alternative expensive solutions of desalinating water currently available today.
India with its high rates of growing population and rapid agricultural and industrial expansion is already concerned about the increasing fresh water demand. Pradip Tewari of the Desalination Division at Bhabha Atomic Research Center, in Mumbai, suggests that a new approach is needed to keep up with the fresh water needs, such as seawater desalination in the vicinity of the coastal regions, brackish water desalination and rain water harvesting, especially in the monsoon season which brings high quantities of precipitation. According to Tewari, the desalination of the seawater and brackish water could play an important role in the country's needs for fresh water.
However, the desalination process of high quantities of water is a highly energetic process. The usage of electricity produced through the burning of fossil fuel reserves to heat high quantities of water is non-economic since the fossil fuel reserves are finite and rapidly depleting and their use must be confined only for other essential uses, meanwhile the demand for freshwater would continue to rise.
Since the use of fossil fuels are out of the question, alternative non-polluting solutions are needed to resolve the water shortage problems, such as wind power, solar energy, tidal power to produce the needed electricity for the desalination process. Even with these alternative means of producing electricity through non-polluting processes, the most realistic method for desalination is by using the great potential offered by the nuclear power.
S.S. Verma of the Department of Physics at SLIET in Punjab suggests the development of small floating nuclear power plants to reduce the environmental impact and the greenhouse emissions, while producing electric power efficiently. The plants could provide extremely cheap electric power for the population and also desalinate seawater with the excess heat they generate. According to Verma, several companies are already in the process of designing a special nuclear platform which will have special desalination units attached to FNPP.
A new technology developed for the desalination of seawater at low temperatures involves the utilization of low-quality waste heat in the form of hot water, at temperatures as low as 50 degrees Celsius or low-pressure Steam from the nuclear plant's steam turbine, which can be converted to high-purity fresh water out of salt water. The Low Temperature Evaporation desalination technique has already proven its reliability, safety and economic advantages. Recently the Bhabha Atomic Research Center in Trombay has commissioned a contract for a low-temperature desalination plant that would be able to produce 50 tons of freshwater a day.
Though the other methods of producing electricity needed to desalinate the seawater, such as tidal or solar power, are cost effective, their use is restricted to small scale fresh water production, thus they would be 'uneconomic' for India's growing economy. Therefore India has turned to nuclear power and has plans to rapidly expand its nuclear industry, which could incorporate large-scale desalination plants.