Page 42 - Curriculum Visions Dynamic Book

Aluminium and the environment
Aluminium is a very reactive element and therefore is normally found locked up as compounds. Most compounds are not at all harmful in the environment and, as in the case of clay minerals, they are positively important.
The only time that aluminium becomes a problem in the environment is as an indirect result of various pollutants that people create.
Of these the most serious by far is acid rain, which increases the acidity of water in the soil. If soils do not contain a buffer
to cope with this onslaught, the soil may well become acid enough for aluminium to go into
solution and find its way into water supplies for animals and plants. As aluminium is a toxic substance, the effects can be serious.
The other important environmental effect of aluminium occurs during mining. Aluminium occurs in surface sheets, and so its recovery destroys large areas of land. Most mines are found in the tropics, and many in tropical rainforests, where conditions are not conducive to the recovery
of the land once it has been disturbed. Furthermore, only a small amount of the ore is transported to refineries, the majority, known as red mud, is often allowed to leave the mines, where it can pollute nearby streams and coasts. There are severe red mud pollution problems in Jamaica, for example.
 Red mud from the chemical processing of bauxite can pollute rivers. In this picture from Jamaica it has been dammed in to form a dead lake.
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