Socrates
Essay by review • November 3, 2010 • Research Paper • 5,215 Words (21 Pages) • 1,881 Views
Introduction
Electrical and Electronics products are now commonly found all around the world and the number is on the rise. The amount of such products that is being disposed is also on the rise. There is a concern on the environmental effect by such products that is being disposed as well as when it is being manufacturer. This is because most of these products contain either harmful substance or non bio-degradable materials which cause an impact on the environment.
For these reasons, regulations and directives are being set up to safe guard and prevent more harm from being done to the environment.
This report would be discussing on the harmful effects by traditional manufacturing and some of the regulatory and directive being set up around the world. Also, responses from the electronics industry with regards to the directives and regulations would be discussed.
1 Traditional manufacturing of electronic equipments
1.1 The use of soldering lead
Solder comprised of tin and lead is currently a fundamental material joining electronic components to circuit boards in the assembly of almost every type of electronic product. Worldwide, over 20 million pounds of tin-lead solder are used annually. [1]
1.2 The manufacturing of PCBs
In the process of making PCBs using the "subtractive" process, the circuit pattern is created by chemically etching copper from the unprotected (non-circuit) areas of the copper-coated panel, leaving circuit traces protected with photoresist.
Etching can be accomplished with acids or bases, depending on the etch rate and the line width required. The most commonly used etchant is an aqueous solution of ferric chloride (FeCl3), used at temperatures over 50 Ð'oC. FeCl3 is acidic, relatively cheap, comparatively innocuous and versatile, attacking aluminium, copper, iron, nickel and their alloys. However, the spent etchant and its rinse water contain heavy metal ions such as nickel and chromium which are hazardous to the environment and most difficult to render harmless.
Approximately 60% of the copper on the board is removed in the typical etching process. As the copper content of the etchant increases, the etchant cannot effectively remove the copper from the board, and it is considered spent. The copper-saturated, spent etchant is stored in drums or a tank, and is ultimately shipped off-site for reclamation. Even in situations where the copper is recovered and the etchant is regenerated by the waste hauler, this waste stream may be an environmental hazard. Transportation of the spent etchant and its ultimate disposition may pose environmental risks and result in increased liability for the PCB facility.
1.3 Disposal of electronic equipments
Electronic equipment is considered hazardous because of the presence of lead, mercury, cadmium, chromium, and some types of retardants. For example, some monitors can contain up to 27% lead. There are four main ways which electronic equipment can be disposed. They are incineration, resale, donation and recycling.
Destruction of electronics equipment means incineration. Businesses are allowed to dispose of their hazardous waste in this manner, but the destruction then falls under more restrictive hazardous waste rules. The incineration process yields some environmentally dirty residue and it is thus not an entirely green option.
Superficially, resale, looks like a good option. It generates profits for the company, the buyers are happy, and the electronics are disposed of. However, liability and administration concerns become an issue. Properly administering a sales program takes time and paperwork, and one has to consider whether used electronics sales are really what the company is in business to do.
Donation is also a valid option. However, electronics are classified as hazardous waste at end of life, and saddling the recipient of the equipment with a disposal liability is an ethical issue. The best arrangement would be to record details of the donation in writing, with an agreement by the recipient to once again properly dispose of the equipment at the end of life/use. Donating without tracking opens up liability issues, and tracking creates considerable additional administrative workload.
Recycling is the best answer to electronics disposal in most situations. A business's liability ends with the recycler. The tracking and handling is the responsibility of the recycler, freeing the equipment's original owner from the administrative hassle of tracking the electronics. This implies a cheaper alternative to destruction. This encourages companies to recycle. Recycling reuses materials, without creating additional environmental poisons. Ultimately, it is good for a company's public image, and is supported by the Environmental Protection Agency (EPA). [2]
1.3.1 Spent etchant disposal
Some 18% of companies disposed of used ferric chloride etchant through waste contractors for landfilling. Landfilling of liquids is a practice which is not encourage as the hazardous heavy metal ions in the waste etchant could escape and subsequently pollute underground waters. The liquid is therefore usually treated by Ð''stabilization and solidification' to form sulfides which are trapped in a solid matrix and cannot be leached out.
Most of the companies (59.0%) sent liquid waste etchant to the chemical companies for reclaim or recycle, as it is not cost effective for them to carry out this task in their own plants. Normally, valuable metals are reclaimed before the waste ferric chloride is recycled to be used as a raw material for another process. For example, in the USA, copper in the waste etchant is first removed by cementation on used tin cans. After oxidation of the resultant ferrous chloride, ferric chloride is then used as a starting material to leach out copper from mined copper ore.
Some 10.2% of companies precipitate out the heavy metals in the waste etchants in-house and, after passing through a filter press, the metals present in the solidified waste filter cake are reclaimed. This is done by a third party who combines the waste with other industrial waste of a similar composition and sells it as a feedstock to smelters. Disposing of the solidified filter cakes at a landfill site was the other option of waste disposal which accounted for 12.8%
1.4 Contribution to environmental pollution
Incineration is one way of disposing waste by burning it at high temperature. Combustion reduces the volume and weight of waste that has
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