Water — CHEMISTRY STD 6 — Question

(a)
Chemical pollution:

A large number of industrial chemicals which include chemicals from paint, textile & dyestuff industry & various acids & salt solutions enter into the water when discharged as industrial wastes.
Chemical pollutants include — Metallic salt solutions of mercury & lead which cause heavy devastation of marine & plant life.
Agricultural wastes include — Poisonous pesticides namely fungicides & insecticides which may also enter underground water through the soil.
(b)
Thermal pollution:
Certain industries such as the iron & steel industry & numerous chemical plants use large amounts of water for varied functions.
The discharged wastewater after going through technical processes is rendered hot & on entering streams of natural water enhances the growth of harmful biological organisms.