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

Column I	Column II
(a) Inorganic impurities.	(i)Phosphorus and nitrogen.
(b) Organic impurities.	(ii) Nitrates and phosphates.
(c) Nutrients.	(iii) Cholera and typhoid.
(d) Bacteria.	(iv) Pesticides and herbicides.

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)?

What are the different types of inorganic and organic impurities generally present in sewage?

The terms sewage, sewers and sewerage are interlinked with each other. Can yon explain, how?

Fill in the blanks in the following statements using words given in the box.
[Air, hand-pumps, cholera, water, large, ground]
A very _____ number of our people defecate in the open. It may cause _____ pollution and soil pollution. Both the surface water and _____ water get polluted. _____ water is the source for wells, tube wells, and _____. Thus, it becomes the most common route for _____ borne diseases like _____, dysentery, etc.

Describe various steps of cleaning wastewater in a wastewater treatment plant.

Think and suggest some ways to minimise waste and pollutants at their source, taking your home as an example.