55
4. What is the meaning of the following terms? Match them with their definitions.
pollutant
CFCs
contaminant
pH
biochemical-oxygen demand (BOD)
dissolved oxygen (DO)
______________ a class of volatile
compounds consisting of carbon,
chlorine, and fluorine.
Commonly called
freons, which have been in refrigeration mechanisms, and, until banned from use
several years ago, as propellants in spray cans.
______________ a substance that has a
detrimental impact on the environment it is in
______________ a substance present in the environment as a result of human activity, but without
harmful effects. However, it is sometimes the case that toxic or harmful effects from contamination
only become apparent at a later date.
______________ one of the most important
indicators of the condition of a water body, necessary
for the life of fish and most other aquatic organisms.
______________ the amount of oxygen, expressed in
milligrams per liter, that is removed from
aquatic environments by the life processes of micro-organisms. It is used in water quality
management and
assessment, ecology and environmental science.
_____________ the measure of the
acidity or
alkalinity of a solution
Do'stlaringiz bilan baham: