NCERT Solutions for Chapter: Wastewater Story, Exercise 3: SHORT ANSWER QUESTIONS

Name two alternative arrangements for sewage disposal where there is no sewerage system.

A man travelling in a train threw an empty packet of food on the platform. Do you think this is a proper waste disposal method? Elaborate.

Why should we not throw used tea leaves into sink?

Why should we not throw cooking oil and fats down the drain?

Match the Items of Column I with the items of Column II with reference to sewage.

Given below is a jumbled sequence of the processes involved in a wastewater treatment plant. Arrange them in their correct sequence.
(a) Sludge is scraped out and skimmer removes the floating grease.
(b) Water is made to settle in a large tank with a slope in the middle.
(c) Large objects like plastic bags are removed by passing wastewater through bar screens.
(d) Sand, grit and pebbles are made to settle by decreasing the speed of incoming wastewater.
(e) Wastewater enters a grit and sand removal tank.

Three statements are provided here which define the terms- (a) sludge, (b) sewage and (c) wastewater. Pick out the correct definition for each of these terms.
(a) The settled solids that are removed In wastewater treatment with a scraper.
(b) Water from kitchen used for washing dishes.
(c) Wastewater released from homes, Industries, hospitals and other public buildings.

A mixture (x) in water contains suspended solids, organic impurities, inorganic impurities (a), nutrients (b), disease causing bacteria and other microbes. Give names for (x), (a) and (b)?