06-03-2012, 04:40 PM
hazardous waste
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ABSTRACT
Some of the products used in our modern society are too toxic to be disposed of without particular treatment. Not only the industry generates such kind of poisonous and hazardous waste but also many household products fall under this category. If not disposed of correctly, some cleaners, solvents, pesticides, paints, etc. can contaminate a landfill, leak into the ground water or contaminate the ocean resulting in tremendous risks for the safety and health of human beings.
Introduction
Hazardous waste can be a liquid, solid, or gas that is actually or chronically hazardous to human health if, not managed, handled or disposed of properly. It may be a byproduct of one or more manufacturing processes or simply be a commercial process.
Improper storage, handling, transportation, treatment and disposal of hazardous waste results in adverse impacts on ecosystems and the human environment. Heavy metals and certain organic compounds are phytotoxic and at relatively low levels can adversely affect soil productivity for extended periods. For example, uncontrolled release of chromium contaminated wastewater and sludge resulted in the contamination of aquifers in the North Arcot area of Tamil Nadu.
How it is generated?
Sources of hazardous waste in the country include those from industrial processes, mining extraction, tailings from pesticide based agricultural practices, etc. Industrial operations generate considerable quantities of hazardous waste and in rapidly industrializing countries such as India the contribution to hazardous waste from industries is largest. Since industrial units are spread all over the country, the impacts are region-wide.
HAZARDOUS WASTE CHARACTERISTICS
Waste is called hazardous if it possesses one or more of the following properties:
1. Ignitable Waste:
If the waste is a liquid with a flash point less than 140-degrees F.
Examples are: Many paint solvents and mineral spirits, paint waste, solvents, alcohol, degreasers, fine carbon particles, flammable gas cylinders.
2. Corrosive Waste:
Among the criteria is a measured pH equal to or less than 2, or greater than or equal to 12.5 in liquid solution
Examples may include: Acids, corrosive cleaners, many photochemicals, strippers, rust removers, batteries, drain cleaners, bases, alkaline liquids.
3. Reactive Waste:
This category takes in a wide field of materials. Generally waste that will cause any of the following e.g.React violently with water, Contains cyanides or sulfides, is unstable, Is capable of explosion, Forms explosive mixtures with water or generates toxic gases when mixed with water. Examples are: sulfide-containing wastes.