water pollution.pptx,KJ.G..K.KU.KUGKU.IU

M,B.JG.KUGKUG.JB.KF.

1. Environment & Ecology Code : CY10I008CY UNIT – 3 Environmental Pollution and its Control Department of Chemistry National Institute of Technology, Raipur 1

2. Outlines Definitions Classification of water pollutants Classification of water pollution Sources of air pollutants Effects of water pollutants Control of water pollutants Discussion 2

3. Definitions WHO “Foreign substances either from natural or anthropogenic sources, contaminated with water supplies, may be harmful to life because of their toxicity, reduction of normal oxygen level of water, aesthetically undesirable and spread epidemic diseases” National Water Commission 1975: Water is said t be polluted if it has not been sufficiently high quality to be useful to man in present or future 3 In general “Any changes in the physical and chemical properties of water is called water pollution”

4. Classification of Water Pollutants Water Pollutants Biological Bacteria Virus Fungi Algae Protozoa Chemical Physical Heat from industries Oil spills from oil carrier Organic Bio-degradable organic waste Pesticides Solvents Polychlorinated biphenyls Synthetic fiber Plastics Petroleum In-organic Phosphates Nitrates Chlorides Inorganic Acids Heavy metals Pb , Cd , Zn, Hg 4

5. Water Pollution On the basis of source of water Ground Water Pollution Surface water pollution On the basis of properties Physical pollution Chemical pollution Biological pollution Physiological pollution Classification of Water Pollution 5

6. Sources of Water Pollution (according to the way in which the pollutants are introduced in water) Point Source The flow of pollutants through regular channels such as sewerage system Factories, wastewater treatment plant outfalls from a factory, leaking underground tanks Non-Point Source The passage of scattered pollutants such as fertilizers and pesticides from ground into water Contamination gathered from a large area 6

7. Sources of Water Pollution (according to their source of origin) Natural Source Minerals Clay Silts from soil erosion Falling organic matters from the banks Runoff Anthropogenic Source Domestic Sewage : wastes passes through sewage system and meet with river, lakes or sea. e.g. Food wastes Synthetic detergents (detergents, bathroom & toilet cleaner) Human excreta Water based paints 7

8. Sources of Water Pollution (according to their source of origin) Anthropogenic Source (B) Industrial effluents : Paper Industries: bleaching substance, cellulose fiber, organic acids Food Industries: organic matter and bacteria Pharmaceutical Industries: intermediate products of drugs and organic solvents Detergent Industries: Fatty acids, alkalis, ammonia compounds Mining Industries: Metal, H 2 S, H 2 SO 4 Steel Industries: Fe, Cr, Hg, cyanide, oil, phenol, naphtha Chemical industries: various alkalis, acids, salts, organic acids, aromatic compounds, volatile organic compounds, solvents, 8

9. Sources of Water Pollution (according to their source of origin) Anthropogenic Source (C) Agricultural Sources : Pesticide and weedicides like DDT, BHC, heptachlor (D) Thermal and Nuclear Power Plants : water used for cooling machines in thermal power stations and from nuclear power plant (along with nuclear wastes) (E) Oil Spills: more common in sea water due to - leaking and spilling of oil from oil tanker - naval transport - accident in naval oil transport and - from off shore oil wells 9

10. Effects of Water Pollution Effects on Human Health: water pollution causes Water born diseases – Cholera, Typhoid, Dysentery, Joyndis NO 3 - - inside the intestine converted into nitrite and enters in blood, causes acute lock of oxygen, the disease known as – blue baby syndrome Metals like Cd – Itai-itai (painful disease of bone and joints), liver cancer Hg – Minimata disease As – Black food disease, diarrhoea , skin and lung cancer 10

11. Effects on Soil: use of polluted water - Reduce soil fertility Severely damage crops and decrease grain production Polluted ground water increases alkalinity in soil Effects of Thermal Pollution : Increases temperature of water bodies Harmful for fishes and other aquatic organisms Dissolve oxygen (DO) decreases which disturb the ecological balance Effects of Water Pollution 11

12. Biological Magnification Insecticides and herbicides destroy the larval stages of aquatic animals Reduce the photosynthetic activities of phytoplankton and algae Aquatic animals may die Effects of Water Pollution 12

13. Control of Water Pollution Use of harmful pesticides should be banned Discharge of effluents directly to river, lacks and sea should be strictly prohibited Oil spills should be prohibited Proper disposal of sewage waste applied should be applied Domestic and industrial waste water should be properly treated before discharging Industrial effluents should be treated to remove pollutants Hot water should be cooled before discharge By imposing laws 13

14. Thank you 14