POLLUTION Chemische Eigenschaften,Einsatz,Produktion Methoden
Definition
pollution: An undesirable change inthe physical, chemical, or biologicalcharacteristics of the natural environment,brought about by man’s activities.It may be harmful to human ornonhuman life. Pollution may affectthe soil, rivers, seas, or the atmosphere.There are two main classesof pollutants: those that are biodegradable(e.g. sewage), i.e. canbe rendered harmless by naturalprocesses and need therefore causeno permanent harm if adequatelydispersed or treated; and those thatare nonbiodegradable (e.g. heavymetals (such as lead) in industrialeffluents and DDT and other chlorinatedhydrocarbons used as pesticides),which eventually accumulatein the environment and may be concentrated in food chains. Other formsof pollution in the environment includenoise (e.g. from jet aircraft,traffic, and industrial processes) andthermal pollution (e.g. the release ofexcessive waste heat into lakes orrivers causing harm to wildlife). Recentpollution problems include thedisposal of radioactive waste; acidrain; photochemical smog; increasinglevels of human waste; high levelsof carbon dioxide and othergreenhouse gases in the atmosphere(see greenhouse effect); damage tothe ozone layer by nitrogen oxides,chlorofluorocarbons (CFCs), andhalons; and pollution of inland watersby agricultural fertilizers andsewage effluent, causing eutrophication.Attempts to contain or preventpollution include strict regulationsconcerning factory emissions, theuse of smokeless fuels, the banningof certain pesticides, the increasinguse of lead-free petrol, restrictions onthe use of chlorofluorocarbons, andthe introduction, in some countries,of catalytic converters to cut pollutantsin car exhausts.
Landwirtschaftliche Anwendung
Pollution is a state of the environment represented by
undesirable changes in the physical, chemical or
biological characteristics of the biosphere brought about
by human activities. Pollution is harmful to humanplant-
and animal life. Air, water and soil are the natural
resources chiefly affected by pollution.
The two classes of pollutants are: (a) biodegradable
materials like sewage, which can be dangerous unless
rendered harmless by specific processes, and
(b) non-biodegradable materials like Pb, Cd and
Hg which are part of industrial effluents.
Dichlorodiphenyltrichloroethane (DDT) and other
chlorinated hydrocarbons used as pesticides accumulate
in the environment and enter the food chain. Other forms
of environmental pollution include noise pollution (such
as from aircraft or traffic or industrial processes) and
thermal pollution (such as excessive heat released into
rivers and lakes causing harm to aquatic life).
Populations of organisms thriving abnormally at the
expense of other populations may themselves be regarded
as pollutants.
Some of the recent pollution problems also stem from
acid rain, radioactive waste and photochemical smog.
Exorbitant levels of carbon dioxide and other green house
gases such as chlorofluorocarbons (CFCs) in the
atmosphere damage the ozone layer. Inland waters mixed
with agricultural fertilizers, as also sewage effluents,
when discharged into the sea, kill marine life.
The need to control environmental pollution in all
its aspects is now widely recognized. Attempts to contain
or prevent pollution include strict regulations concerning
(a) limits on factory emissions, (b) use of smokeless
fuel, (c) use of certain pesticides, (d) use of lead-free
petrol, (e) limited use of chlorofluorocarbons, and
(f) use of catalytic converters to cut pollutants in car
exhausts.
POLLUTION Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
