Theory question 103
Pollution(a) State eight human activities that may pollute water bodies.
(b) Explain the measures that may be used to prevent pollution of water bodies.
(c) Mention four methods of purifying water.
Show the model answer
(a) Any eight: dumping refuse into water; discharging untreated sewage; oil spills from drilling and tankers; run-off of fertilisers and pesticides; discharging industrial chemicals, dyes and detergents; hot water from factories (thermal pollution); radioactive waste; using chemicals (e.g. gammalin) or explosives for fishing; washing and bathing in drinking water sources; mining waste.
(b) Treat sewage before discharge; dispose of refuse properly (burn, bury, recycle) and not in water; treat industrial waste and cool hot water before release; use fertilisers and pesticides in correct amounts; use biodegradable detergents; clean up oil spills (detergents/booms); laws and penalties against polluters and against chemical fishing; educate the public.
(c) Any four: boiling; filtration; sedimentation (settling) with alum; chlorination; distillation; use of ultraviolet light; aeration.
List distinct activities, not the same one in different words.