VPE 511: Environment and Environmental Hygiene (2+1)

CLASSIFICATION OF POLLUTANTS

• Primary pollutants: The substances emitted directly from an identifiable source are called primary pollutants. Eg., sulfur dioxide , nitrogen oxides , etc.
• Secondary Pollutants: These are derived substances or effects from primary pollutants. Eg, peroxyacetyl nitrate.
• Biodegradable pollutants: The pollutants that can be readily decomposed by natural processes or by engineered methods in a relatively small time are called biodegradable pollutants. Eg, municipal sewage.
• Non-biodegradable pollutants: Pollutants, which are resistant to biological action of normal organisms in the environment, are called non-biodegradable pollutants. Eg, DDT, mercury, lead, etc.