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Quality of drinking water, , ‘* Drinking water should be colourless, odourless and with out turbidity, ‘There should be no insolouble impurities, , * pH value should be between 6.5 to 7.5, , ‘There should not be desease causing micro organisms, , Diseases that spread through drinking water, , Diseases spread through water when the disease causing microorganisms grow in water used, for drinking. Mixing up of excreta and other pollutants with drinking water is one reason for the, pollution of drinking water. The presence of the bacteria E coli, which reach water through excreta, causes the disease diarrhoea. Typhoid, cholera, dysentery and jaundice are some of the other, diseases that spread through drinking water., , Traditional water purification methods, , + Filtration using cloth, * Adding charcol to water, , , , ainoeainemng,0s asjoa8 allwlogad. cowenspjo a/iula@oeye aidlesacd TECH Malappuram vnomiveao30, ale ©9900 allamilgilay (WOTdMOajn| qj AqjSqYoR® ciienjo cwoerBacions Oantes woaqyod oarme., hittps://play.noogle.com/store/apps/details?i sith sasthracheppua, , , , , fo1, 7, , ‘TECH Malappuram (Teacher Empowerment through Co-operation and mutual Help), , , , , , © Adding lime, + Filtration using three potted pot, , How water is purified while using a three potted filter, , ‘The gravel in the top pot filters the large particles in water. The sand in the middle pot filters the, mud. The charcol in the bottom pot absorbs the poisonous components in the water., , To see a video on this topic, click on the following link, , https://www.youtube.com/watch?v=Gyts'sIViYU&dlist=PL9AshZEiXvDI62eUjwlcdx)zzyB02UdUP&index= 10,, , , , Steps of water purification in water treatment plants, Aeration - The process of mixing water with air, Thus the amount of oxygen in the water increases., , Coagulation —This enables the sedimentation of solid matter present in water. Alum is added for this,, , pH regulation - When alum is added to water for coagulation, the pH value of water decreases. So lime is, added to regulate the pH., , Filtration In this stage, the mpurities which do not get settled are removed by the filter. Fine sand, and gravel are used in the filter unit as two layers., , Chlorination ~ Chlorine gas or bleaching powder is mixed with it to sterilize the filtered water., Is it right to use the drinking water supplied in public taps for other purposes?, , No. The water in public tap is supplied after many expensive purification process. Such a quality, water is not needed for other purposes., , Air pollution, , Air is said to be polluted when there, , , , = Nitrogen 78% is any change in the normal amount, mm Oxyg 20.9% of any of the components of air or, ‘tm Carbon dioxide - 0.03% when foreign substances mix with, , m= Others 1.07% air. Increased rate of pollution