The “Wastewater Story” chapter emphasizes the need for clean water and proper wastewater management. Sewage, a mix of domestic and industrial waste, requires treatment to remove pollutants through physical, chemical, and biological processes. Everyone plays a role in minimizing waste, maintaining sanitation, and preventing waterborne diseases.
Water, Our Lifeline
- Clean water is super important for us to drink and stay healthy; it’s like a lifeline for everyone.
- Many people don’t have safe water to drink, and some have to walk far to get it, which can make them sick.
- Too many people, dirty rivers from pollution, factories, and bad planning make clean water harder to find.
- The United Nations wants to make sure more people get safe water; they’ve been working on it for years.
What Is Sewage?
- Sewage is dirty water from homes, factories, hospitals, and offices—full of yucky stuff.
- It has bits of dirt, waste from people and animals, oil, chemicals, and tiny germs that can make us sick.
- When it rains hard, water runs off streets into sewage, picking up more bad stuff along the way.
Water Freshens Up
- Clean water comes to us through pipes, and dirty water leaves through a different set of pipes.
- A system of big and small pipes, called sewers, carries the dirty water away to a special cleaning place.
- There are holes called manholes in the sewer system so people can check or fix it when needed.
Wastewater Treatment Plant
- Dirty water goes through steps to get clean again using different ways to remove the bad stuff.
- First, big things like rags, sticks, and plastic get caught by screens and taken out.
- Then, the water slows down in a tank so sand, grit, and pebbles can sink to the bottom.
- In a big tank, heavy stuff like waste settles down as sludge, and oily stuff floats up to be scooped off; the cleaner water in the middle is called clarified water.
- Sludge goes to another tank where tiny helpers (bacteria) break it down and make biogas, which can be used for power or fuel.
- Air gets pumped into the clarified water to help good bacteria eat up leftover waste like food bits and soap.
- After a while, the bacteria settle as sludge, and the water on top is much cleaner; the sludge can be dried and used as plant food.
- The treated water is clean enough to go into rivers, seas, or the ground, sometimes after adding chlorine to kill any germs.
Better Housekeeping Practices
- Don’t pour cooking oil or fats down the drain—they can clog pipes and stop water from filtering through soil; throw them in the trash instead.
- Keep chemicals like paints, bug sprays, motor oil, or medicines out of drains—they hurt the helpful germs that clean water.
- Throw things like tea leaves, food scraps, cotton, or toys in the dustbin, not the drain, so they don’t block pipes or stop oxygen from helping break down waste.
Sanitation and Disease
- Dirty water and bad sanitation make people sick with diseases like cholera, typhoid, and dysentery.
- In some places, people don’t have toilets and go outside near rivers or fields, which spreads germs into water and soil.
- This dirty water gets into wells, springs, and rivers, making more people ill when they use it.
Alternative Arrangement for Sewage Disposal
- Places without big sewer pipes can use small systems like septic tanks or composting pits to handle waste.
- Some toilets don’t need people to clean them; waste flows into a biogas plant that makes energy instead.
- There are special toilets with earthworms that turn waste into safe soil cakes, using very little water.
Sanitation at Public Places
- Busy spots like train stations, airports, and fairs make lots of waste every day that needs to be cleaned up properly.
- The government has rules to keep these places clean, but sometimes they’re not followed well.
- We can help by not littering and using dustbins—or taking trash home if there’s no bin around.
- India’s “Swachh Bharat” mission is working to build toilets and clean up waste so everyone stays healthier.
Questions and Answers
- Fill in the blanks:
- (a) Cleaning of water is a process of removing pollutants.
- (b) Wastewater released by houses is called sewage.
- (c) Dried sludge is used as manure.
- (d) Drains get blocked by oils and fats.
- What is sewage? Explain why it is harmful to discharge untreated sewage into rivers or seas.
- Sewage is wastewater released by homes, industries, hospitals, offices and other users. It contains dissolved and suspended impurities. Discharging untreated sewage into rivers or seas is harmful because untreated human excreta is a health hazard and can cause water and soil pollution. This can further pollute both surface and groundwater, leading to waterborne diseases like cholera, typhoid, polio, meningitis, hepatitis, and dysentery.
- Why should oils and fats be not released in the drain? Explain.
- Oils and fats should not be released into the drain because they can harden and block the pipes. In an open drain, the fats clog the soil pores reducing its effectiveness in filtering water.
- Describe the steps involved in getting clarified water from wastewater.
- The steps involved in getting clarified water from wastewater include:
- Allowing the water to settle in a large tank which is sloped towards the middle.
- Solids like faeces settle at the bottom and are removed with a scraper; this is the sludge.
- A skimmer removes the floatable solids like oil and grease.
- The steps involved in getting clarified water from wastewater include:
- What is sludge? Explain how it is treated.
- Sludge consists of solids, like faeces, that settle at the bottom of a large tank during wastewater treatment. It is transferred to a separate tank where it is decomposed by anaerobic bacteria. The biogas produced can be used as fuel or to produce electricity. Dried sludge is used as manure, returning organic matter and nutrients to the soil.
- Untreated human excreta is a health hazard. Explain.
- Untreated human excreta can cause water and soil pollution. Both surface water and groundwater can become polluted, leading to the spread of waterborne diseases such as cholera, typhoid, polio, meningitis, hepatitis, and dysentery.
- Name two chemicals used to disinfect water.
- Chlorine and ozone can be used to disinfect water.
- Explain the function of bar screens in a wastewater treatment plant.
- Wastewater is passed through bar screens in a wastewater treatment plant to remove large objects like rags, sticks, cans, plastic packets, and napkins.
- Explain the relationship between sanitation and disease.
- Poor sanitation and contaminated drinking water can cause a large number of diseases. Untreated human excreta is a health hazard and can cause water and soil pollution, leading to waterborne diseases.
- Outline your role as an active citizen in relation to sanitation.
- As an active citizen, you can:
- Approach the municipality or the gram panchayat to insist that open drains be covered.
- Request that neighbors be more considerate about others’ health if their sewage is making the neighborhood dirty.
- Avoid throwing chemicals, oils, fats, and solid waste down the drain.
- Contribute to maintaining sanitation at public places by not scattering litter and using dustbins.
- As an active citizen, you can:
- Here is a crossword puzzle: Good luck!
- Across
- 3: Effluents
- 4: Sludge
- 6: Hygiene
- 8: Excreta
- Down
- 1: Wastewater
- 2: Sewer
- 5: Vibrio
- 7: Ozone
- Across
- Study the following statements about ozone:
- The correct statements are (b) and (c): It is used to disinfect water and it absorbs ultraviolet rays.
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