Page 168 - Ripples SCIENCE 7 - TEJPUR Edition 2024 Answer Key

Composting toilet: Composting toilet treats human waste with biological processes.

The bacteria present in a storage tank act upon the waste and turns it into compost,
which can be used in agricultural farms.

10. Enumerate effects of improper sewage management.
Ans: Effects of Improper Sewage Management

• Soil contamination: Soil gets contaminated when toxic chemical waste from
industries or agricultural fields seeps into the soil and alters its chemical nature.

• Water contamination via improper wastes: Water is an excellent solvent; it
can contain often has dissolved substances like various chemicals and gases.

Rainwater easily mixes with these toxic substances, flows into the water streams
and ends up in nearby water bodies. Thus, the nearby fountains, ponds, lakes or

even drinking water taps are susceptible to the dangers of contamination.
• Severe weather due to climate contamination: Harmful greenhouse gases are

created from decomposing waste. These rise up into the atmosphere and trap
heat. This causes extreme adverse weather conditions in the form of storms

and typhoons.
• Harmful for the animals and marine life: The continual dumping of garbage,

raw or untreated sewage, into water bodies results in the formation of algal
bloom. This is rapid increase in the population of algae in an aquatic system.

They are a result of excess of phosphorus and nitrogen in water and suffocates
marine life, such as corals and fish.

• Eutrophication: The presence of excessive nutrients in a lake or a water body
due to agricultural run-off from the land causes excessive growth of plant life in

it. Fertilisers contain phosphates that promote the growth of algae in water. The
algae cover and the excess plant growth results in the depletion of dissolved

oxygen in water bodies and deterioration of water quality.
• Eutrophication is the enrichment of nutrients in water bodies that promotes

excess growth of plant life.

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