Chapter 13: Wastewater Story

Science • Class 7

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Chapter Analysis

Intermediate11 pages • English

Quick Summary

The chapter 'Wastewater Story' explains the importance of cleaning water and managing wastewater. It discusses various sources of wastewater, the process of sewage treatment, and its significance in preventing diseases. The chapter emphasizes the role of individuals and communities in maintaining sanitation and explores different methods of waste disposal and management.

Key Topics

  • Wastewater treatment process
  • Importance of sanitation
  • Sources of sewage and wastewater
  • Sewage treatment plant functions
  • Role of bacteria in waste management
  • Public health and sanitation
  • Alternative sewage disposal methods
  • Citizen role in sanitation

Learning Objectives

  • Understand the processes involved in wastewater treatment
  • Identify the effects of untreated sewage on health and environment
  • Recognize different methods and facilities for sanitation
  • Explore the historical advancements in sanitation systems
  • Learn about individual and community roles in maintaining sanitation
  • Assess the impact of poor sanitation on public health

Questions in Chapter

What is sewage? Explain why it is harmful to discharge untreated sewage into rivers or seas.

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Why should oils and fats be not released in the drain? Explain.

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Describe the steps involved in getting clarified water from wastewater.

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What is sludge? Explain how it is treated.

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Untreated human excreta is a health hazard. Explain.

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Name two chemicals used to disinfect water.

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Explain the function of bar screens in a wastewater treatment plant.

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Explain the relationship between sanitation and disease.

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Outline your role as an active citizen in relation to sanitation.

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Here is a crossword puzzle: Good luck!

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Additional Practice Questions

What are some ways to prevent wastewater contamination at home?

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Answer: To prevent wastewater contamination at home, avoid pouring oils and fats down the drain, dispose of chemicals properly instead of washing them down, and reduce the use of harmful cleaning agents.

How does a sewage treatment plant work?

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Answer: A sewage treatment plant removes contaminants from wastewater through procedures such as screening, sedimentation, and biological treatment, converting it into environmentally safe water.

What is the role of aerobic bacteria in wastewater treatment?

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Answer: Aerobic bacteria break down organic matter in wastewater through aerobic processes, helping to purify the water by reducing organic contaminants.

Why is it important to not defecate in the open?

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Answer: Open defecation can lead to the spread of diseases such as cholera and typhoid by contaminating water sources and food supplies.

What are some low-cost on-site sanitation systems?

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Answer: Examples include septic tanks, composting toilets, and biogas toilets, which manage waste locally without requiring extensive infrastructure.

Discuss the historical significance of the Indus Valley Civilization's sanitation system.

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Answer: The Indus Valley Civilization had advanced urban planning including covered drains and public baths, showcasing early engineering feats in sanitation.

How can individuals contribute to public place sanitation?

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Answer: Individuals can ensure litter is disposed of properly, report unsanitary conditions to authorities, and participate in community clean-up drives.

Explain the process of sludge treatment in a wastewater plant.

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Answer: Sludge is treated by anaerobic digestion, where bacteria decompose solids, producing biogas that can be used as energy.

Why is it necessary to disinfect treated wastewater before releasing it into the environment?

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Answer: Disinfecting treated wastewater is crucial to eliminate remaining pathogens, ensuring the water is safe for ecosystems and human use.

What impact does poor sanitation have on public health?

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Answer: Poor sanitation leads to the spread of infectious diseases, affects water quality, and has broader impacts on community health and development.

NCERT Exemplar

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Practice with NCERT Exemplar problems and solutions for this chapter. Exemplar problems are designed to help you master the concepts with advanced-level questions.

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