Chemistry Reference
In-Depth Information
10. Potable Water
Topic
Commercial techniques can be used in the laboratory to purify water.
Introduction
Clear, sparkling water flowing in a stream may appear to be pure, but
it most likely contains contaminants. According to the Environmental
Protection Agency, about 90 percent of the world's water is contaminated
in some way. Water can be contaminated by many different sources,
including nitrates from fertilizers and animal wastes, chemicals such as
polychlorinated biphenyls (PCB)
and
benzene
from industrial processes,
gasoline from leaky tanks, chlorine and fluorine from water treatment
plants, copper and lead from pipes, and organic wastes from septic
tanks (see Figure 1). In addition, disease-causing microorganisms such
as bacteria and
protozoans
inhabit many waterways. Therefore, as a
precaution, water should be purified before it is consumed.
smog
chlorine
fluoride
smoke
air pollution
acid rain
fertlizer
industry
landfills
copper and
lead pipes
nitrates
chemical spills
PCBs/benzine
toxic
wastes
leaking
gas tanks
municipal
treatment
septic
system
Figure 1
Potential sources of water contamination
