To control water pollution:
(i) Minimising used water for processing by reusing and recycling it in two or more suggestive stages.
(ii) Harvesting of water can be done to meet water requirements.
(iii) Treating of hot water and effluents before releasing them in rivers and ponds.
(i) Primary treatment by mechanical me It involves screening, grinding, flocculation and sedimentation.
(ii) Secondary treatment by biological process.
(iii) Tertiary treatment by biological, chemical and physical processes. This involves recycling of water.
(i) Particulate matter in the air can be reduced by fitting smoke stacks to factories with electrostatic precipitators, fabric filters and inertial separators.
(ii) Smoke can be reduced by using oil or gas instead of coal in factories or thermal power stations.
Machinery and equipment can be used and generators should be fitted with silencers.
Almost all machinery can be redesigned to increase energy efficiency and reduce noise.
(ii) Noise absorbing material may be used apart from personal use of earplugs and earphones.