Environmental Networking Platform for Children and Youth by SAMSUNG E&A
Stay connected with Eco-generation :
| Share 
| 
- Home >
- Our Actions >
- Ambassador report
6
Comments
HAZARDOUS-WASTE CONTROL |
|---|
|
by Razaan Abakar | 01-12-2017 02:27
|
|
A. Source Reduction The best way to eliminate hazardous wastes is not to generate them in the first place. For example, improvements have been made in the production of integrated circuits: The toxic chlorinated hydrocarbons commonly used in the 1970s were replaced in the 1990s by low-toxicity esters and alcohols. B. Recycling Recycling is the recovery or reuse of usable materials from waste. For example, approximately 15 percent of sulfuric acid is recycled in chemical manufacturing. In the past, most sulfur used for sulfuric acid production was mined; now the amount of sulfur recovered from smelters (facilities that remove metals from ores), refineries (facilities that purify substances), and manufacturers is more than double that produced by mining. C. Treatment Wastes may be made less hazardous by physical, chemical, or biological treatment. For example, sodium hydroxide has been used to treat acid wastes at integrated-circuit plants. Some newer plants now treat hydrofluoric acid wastes with lime, producing relatively harmless calcium fluoride, the mineral fluorite. Sulfuric acid wastes, if not recycled, can be treated with ammonia wastes from the same plant, forming ammonium sulfate, a fertilizer. Incineration has been used since human beings learned to control fire. It is the preferred method of handling infectious medical wastes. However, it should not be used for wastes that contain toxic heavy metals or chlorinated hydrocarbons: When burned, old painted surfaces can release lead or arsenic into the air, whereas chlorinated hydrocarbons produce hydrochloric acid and dioxins. Solids left over from incineration may have to be disposed of as hazardous waste. Solidification of wastes involves melting them and mixing them with a binder, a substance that eventually hardens the mix into an impenetrable mass. One suggested treatment of radioactive waste involves turning it into a glass through a process known as vitrification. simple remedies such as covering the waste may be sufficient. Other stabilization methods involve building a barrier around the waste. This barrier can be of plastic, steel... etc D. Disposal Surface impoundment (placing liquid or semiliquid wastes in unlined pits) keeps waste in long-term storage, but it is not considered a method of final disposal. About 8 percent of hazardous waste is injected into deep wells; 21 percent enters landfills (large, unlined pits into which solid wastes are placed) as its ultimate resting place. The serious problem of underground plumes of hazardous materials leaving the original disposal sites has only partial solutions at this time. The typical method of handling this problem is the drilling of wells around a plume's perimeter. Hazardous materials are then removed from some wells, and water may be injected into other wells to produce a barrier to the plume's motion. Drilling wells and monitoring holes near a toxic site carries risks; a plume originally confined between strata (horizontal layers of rock) may penetrate vertically through a drilled hole and escape confinement. A recent method of treatment for shallow plumes of chlorinated solvents depends on their chemical reactivity. A trench is dug around the leaking waste site and filled with a mixture of soil and powdered iron. The iron then reacts with the chlorinated solvents, turning them into simple hydrocarbons, which are less hazardous. SOURCE: Microsoft ? Encarta ? 2017. © 1993-2017 Microsoft Corporation. All rights reserved. |
|
|
|
|
Previous : Waste in Abidjan
6 Comments
love you, people, your work is effective
Posted 29-01-2018 19:33
alarming man
Posted 29-01-2018 19:33
the pollution level is so high that the earth is about destroy
Posted 29-01-2018 19:33
Dear Razaan! Thank you for sharing!
Posted 11-12-2017 21:33
Thank you @Stephanie ^_^
Posted 01-12-2017 23:49
Hi, Razaan! This must be the second part of you entire report on hazardous waste :) Thank you for explaining the methods for safe disposal of different types of hazardous waste. With hazardous waste being a major environmental problem in our current-day society, safe disposal will be the most important part in solving the problem. Although theoretically, the best way to get rid of the problem altogether would be to stop using chemical products, this is virtually impossible (or at least for the time being) because chemical products are used in nearly all aspects of our daily lives. For now, the best solution would be to do our best in safe usage and disposal of hazardous waste. Thank you for your report!
Posted 01-12-2017 16:54