Day 12

Bottled Water

The Bottled Water Industry

The bottled water industry is growing at a rapid rate around the world.
The largest single market is Europe where people have been drinking bottled water for nearly 200 years. The estimated total European consumption is 27.7 billion litres per year; the annual per capita consumption is estimated at 93.7 litres.
The next largest market is the United States with an estimated total consumption of 11 billion litres. Having emerged in the 1970s, the U.S. is a relatively young market but a very dynamic one.
Asia is the third largest market with probably the greatest growth potential due to its high population growth.
Latin America ranks fourth in bottled water consumption, and Canada follows in a strong fifth position.

ACTIVITY FOR STUDENTS: Materials needed: 10 different brands of water (oxygenated, carbonated….)
Ask students to name as many brands of bottled water as they can think of. Write them on the board. Ask them if they know the difference between spring water, mineral water, distilled water, carbonated water, deionized water and well water. Define different types. See Appendix 16.
Have students sit in groups of 4 or 5. Place 3 different brands of bottled water with each group. Have one person record the contents while the others find the information to answer the following five questions. (35 minutes)

What is the brand name of the water?
What kind of water is it?
Where is it bottled?
List the different contents.
Look closely at the packaging and design. What message does it give?
Carefully examine the design and label of the product. What image are they creating?

Definition of terms for Appendix 16 (review Appendix 16 and discuss these definitions with students)

Dissolved solids

All water has some dissolved solids in it that you can not see. They are minerals such as calcium, manganese and magnesium. These dissolved solids can be measured. Parts per million or grains per gallon are the most common. One part per million (PPM) is just what it says: out of one million units, one unit. Grains, or grains per gallon (GPG) is a weight measurement taken from the Egyptians; one dry grain of wheat, or about 1/7000 of a pound. It takes 17.1 PPM to equal 1 GPG.

Distillation
One of the oldest methods for cleaning water is distillation. Simply put, you boil water, catch the steam, and condense it back into water. Theory is, the minerals stay behind in the boiling chamber, and only ‘pure’ water ends up in your container.
Therefore, distilled water is water that has been boiled and then recondensed (that is, the water vapor is turned back into liquid water on a cold surface).

Deionization
DeIonization works by ion exchange. As hard water passes through the tank which holds two kinds of plastic like beads, called resin, the positive and negative minerals (ions) attach themselves to the resin. The Cation resin removes the ions with a positive charge, while the Anion resin removes those ions with a negative charge. This process is called "ion exchange". When the resin has no ions left, it is exhausted, and can deionize no more water. The resin is recharged by flushing with acid and caustic. This forces the minerals off the resin beads; then the excess acid and caustic solution is rinsed away, and the resin is ready to start the process all over again. This cycle can be repeated many, many time before the resin loses it's ability to react to these forces.

Reverse Osmosis
To understand "reverse osmosis," it is probably best to start with simple osmosis. Osmosis is the "movement of a solvent (a liquid in which a substance, such as salt, can be dissolved) through a semipermeable membrane that allows some molecules through but not others (for example water molecules but not salt molecules) into a solution of higher solute concentration (higher concentration of dissolved salt) that tends to equalize the concentrations of solute on the two sides of the membrane."

In reverse osmosis, the idea is to use the semipermeable membrane to act like an extremely fine filter to create drinkable water from salty (or otherwise contaminated) water. The salty water is put on one side of the membrane and pressure is applied to stop, and then reverse, the osmotic process. It generally takes a lot of pressure and is fairly slow, but it works.

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