Chemistry article retel 2
Uploaded by kelizabeth on Sep 08, 2008
Editorial: Liquid asset
One third of the world's population already lives in water-scarce areas. And stocks of water are dwindling: not only because a burgeoning population needs to quench its thirst, but also to meet increasing agricultural demands for crop growth. Add to that the water demands of low-carbon alternatives to fossil fuels, including biofuels and hydrogen (see Chemistry World , May 2008, p12), and industry's insatiable appetite for water, and it's clear demand is rapidly overwhelming supply.
Many predict that the major conflicts of the coming century will be fought over water. And the unpredictable impacts of climate change mean that we cannot simply rely on surface water resources to continue to be replenished by rain.
Time to compromise
The issue is not just quantity, it's quality. Urban pressure on water supplies means more and more people are quite literally tapping the same sources - and also that water treatment has to cope with a swathe of previously undiscovered pollutants (see p48). Many of these, including active pharmaceuticals, simply slip through traditional water treatment systems. More advanced purification systems are already in existence that are capable of removing almost all of them, but at what cost? There are questions to be answered about the impact of new pollutants before money is spent on removing them.
Only the best scientific advice will aid the development of good water management, which, in some cases is going to prove very expensive indeed. There will often be simpler solutions: it cannot be sensible for people in many developed countries to continue to use high quality, drinkable water to flush toilets and water lawns while more than one in six people throughout the world have no access at all to safe, clean drinking water. The scientific community must play a key role in deciding in which direction the money flows (see p44).
In the aquatic environment, we have already seen the effects of some wastewater compounds on ecosystems - certain hormones that we regularly flush away, for example, have been found to affect the development of fish, and to reduce their rates of reproduction. We have a moral obligation to monitor these effects and their causes closely. Only through rigorous and well coordinated environmental monitoring can we really know which compounds pose a serious threat to ourselves and our environment
(see p54).
Less is more
The appetite for water is most...