Thursday, September 1, 2011

Water Shortage

Article :

There are already around 3 billion people in the world struggling to keep up with the demand for the fresh water. This number is expected to double in the next 20 years and there has been several different possible solutions for this issue such as conservation and reuse but one of the most interesting solutions definitely looks to be desalination. Why desalination? Well, lets just say that our oceans cover around 70% of our planet and therefore represent the virtually inexhaustible source of water. So why not use water desalination then and fix the water shortage problem? The main problem with desalination is that the process of removing salt from the seawater is extremely energy intensive and therefore highly expensive. There have been many different scientific studies which tried to make desalination process commercially viable but none of it has so far managed in achieving this. The currently dominating process of desalination is the so called reversal osmosis in which seawater is forced through a membrane that filters out the salt. The scientists have done several studies in which they tried to increases the membrane's water flux, and the latest researches which used carbon nanotubes have proved to be the most promising of them all. One of the most interesting recent studies comes from the University of Notre Dame. According to this study it is pointless to try to increase the membrane's water flux because the current technology is already starting to approach its efficiency limit and science should instead focus on possible gains in efficiency during the pre- and post-treatment stages of desalination. The desalination will likely play enormous role in future because this will likely remain the only available method to satisfy world's demand for water, particularly if world population continues to grow rapidly in years to come as expected.


Thoughts:

In Singapore, we have the four national taps which apart from desalination, consists of imported water, water from catchment areas and NEWater. Currently, Singapore has a desalination plant in Tuas built in 2005. Even though desalination takes up only about 10% of Singapore's water supply, in the future it is going to be a key pillar of Singapore's sustainable water supply along with NEWater which contributes 30% of consumable water. The other sources of obtaining water such as imported water are not long term solutions as agreements will expire and whether the country plans to continue the agreement with Singapore is up to the other party and this could make Singapore vulnerable even though imported water is the most efficient way and it also does not use much land space. Furthermore, despite being able to keep the cost of water treatment down, this is not a great solution too. Singapore currently has 15 reservoirs and to collect more rainwater more catchment ares have to be build and this is not very feasible as Singapore is faced with land constraints and currently, the area of the catchment areas covers up to half of Singapore's land. Therefore, i agree with the article where it claims that " The desalination will likely play enormous role in future because this will likely remain the only available method to satisfy world's demand for water, particularly if world population continues to grow rapidly in years to come as expected. " This is very likely as we a quite a rich nation, thus we can afford such technologies and the abundance of sea water available.

No comments:

Post a Comment