1 Some facts about water
Did you know?
At any one time, half the hospital beds in the world are said to be occupied by people suffering from water-borne illnesses.
This Unit looks at water treatment and gives an insight into the use of science and maths for the betterment of people's lives.
We can all relate to water. We know we need it to survive – indeed all the great civilizations of the world (the Egyptian, Greek, Mesopotamian, etc.) were centred around river valleys where there was a plentiful supply of fresh, clean water.
When we take water into our bodies, it is used in several ways – as a coolant (keeping our body at a temperature of 98.4°F or 36.9°C), as a waste disposal medium, as a conductor for nerve impulses, and as a component in the digestion of food.
You can see from the above that even if you didn't move an inch, your body would still need water to keep you alive. A survival handbook I read recently says that people can live for 21 days without food but for only 10 days without water. I suspect this must be for a temperate climate. In the desert, in summer, the limit might only be a day or two.
Water is a fascinating subject, encompassing chemistry, biology and physics. Apart from keeping us all alive, water is used extensively in industrial processes, and for recreation and transport. It is something we can't do without. The water we use for domestic purposes has to be free of contaminants – more than 25000 people are said to die each day from ingesting poor-quality water!
In this course, we start from the basics – the hydrological cycle and the natural aquatic environment. Then we gently glide into water treatment, water supply and water conservation. As a society, we are getting more and more water-hungry – one of the signs of affluence!