The machines that we use in agriculture, manufacturing, mining, and construction eventually break down and become unwanted pieces of metal. It is important we dispose of this metal properly, and, if possible, recycle it.

Disposal

We dispose of most of our garbage by two main methods, landfill and incineration.

Landfill is a common practice in most countries, usually filling up abandoned mines or quarries. Although it seems to be a cheap way of getting rid of garbage, landfills can damage the environment if not controlled. Landfill emit gases that pollute the air. Metals and their compounds in landfills can make their way into the soil, contaminating water bodies nearby.

Incineration, the burning of waste materials at high temperature into steam, ash, and gases, is an energy intensive process. It is usually undertaken only when there is not enough land for landfills.

Most countries in the European Union have strict rules regarding waste disposal. For example, electronic waste can contain traces of lead, mercury and cadmium. They must be disposed according to laws such as the Waste Electrical and Electronic Directives (WEEE) and Restriction of Usage of Hazardous Substances (RoHS). Similar laws are also coming into force in other parts of the world.

Recycling

Recycling turns used materials into fresh materials that can be used again. This benefits us in many ways. There is less garbage overall, making it easier to deal with it properly. The used metals do not end up in landfills, polluting the air, soil and water. It also reduces the amount of new metal that must be extracted from the ground, saving natural resources and energy. It also reduces the cost of metal objects, because recycling scrap metal is often less costly than extracting new metal.

Recycling of electronic devices such as computers and mobile phones is best done at recycling plants. Such plants can separate metals from other waste such as plastics in a cost-efficient manner. Such recycling plants might also accept some types of batteries.

The recycling of batteries is made difficult by the wide variety in type and size of batteries. Each type of battery needs a different recycling process, so we must sort batteries into the right groups for recycling. Some older batteries contain mercury and cadmium, which must be handled with care and caution. Proper disposal of used batteries is mandatory in many areas, to avoid harm to the environment. Lead-acid batteries used in automobiles are fairly easy to recycle. Many areas have laws that require vendors to take in used batteries for recycling. In the United States, the rate of recycling for automobile batteries is about 90%, and new batteries sometimes contain up to 80% of recycled material.

Another item that we should try to recycle is ink cartridges for printers. These cartridges often contain hazardous heavy metals that need to be handled carefully. Only some manufacturers help their customers in recycling spent cartridges. Today we recycle only a quarter of all ink cartridges; surely we can do better!

References:

Recycling, Wikipedia. <http://en.wikipedia.org/wiki/Recycling> accessed on 13th March 09.

Guna seelan. Why scrap metal recycling is good for the environment, Articlebase.com. <http://mynewsdigest.com/Internet/ECommerce/Why-Scrap-Metal-Recycling-is-Good-for-the-Environment(5007).htm> accessed on 17-March-2009.

Ink cartridge recycling program, UConn Office of Environmental Policy. <http://www.ecohusky.uconn.edu/inkcartridgerecycling.htm> accessed on 28-March-2009.

Waste management, Wikipedia. <http://en.wikipedia.org/wiki/Waste_management> accessed on 21-March-2009.