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Similar to ENS 301 - Water Pollution - PPT 1 - Agri Junction.pptx
ENS 301 - Water Pollution - PPT 1 - Agri Junction.pptx
- 1. WATER POLLUTION Water pollutioncan be defined as the natural or man induced changes in the quality of water, which may render it unsuitable with regard to food, human health, animal health, industry, agriculture, fishing, washing or recreational purposes Point discharge Non Point discharge
- 3. SOURCES OF WATERPOLLUTION NATURAL AND ANTHROPOGENIC SOURCES (MAN MADE) Natural sources: Occur due to high concentration of minerals or salts in soil - to cause pollution of water = geological source 1. Arsenic pollution – West Bengal, B’desh Keratosis (Warts and lesions) WHO limit – 0.05 mg/l 2. Fluoride pollution – R’than, AP, Orissa, Punjab, TN Dharmapuri and Salem Fluorosis Knock knee syndrome – bending of legs WHO limit – 1 mg/l 3. Surface runoff - Heavy rains brings dirty water in river, ponds
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- 6. Anthropogenic sources Industrialeffluents – Waste water from industries - tanneries, textiles & dying, food process, petroleum industries, pharmaceuticals, fertilizer factories, sugar factories etc., Agriculture – fertiliser leaching and pesticide Household wastewater – sewage (urban wastewater) Oil pollution – oil spills Radioactive pollution – nuclear activities
- 8. Types of pollutants Physicalimpurities & chemical impurities Physical impurities • Solids – small sticks, sand, gravel, inert matls… • Dissolved gases – Chlorine, ammonia, O2, H2S.. • Colour – black, brown, dark, light, multicolour.. • Temperature – Thermal effluents (hot effluent) • Odour – smell • Turbidity – clear water/ less clear/ turbid…
- 9. Types of pollutants Chemicalimpurities i. Organic impurities – fats, proteins, starch, cellulose, phenols, lignin residues in WW… ii. Inorganic impurities – Chemicals like sodium, calcium, sulphate, magnesium, chlorides, heavy metals, carbonates, pesticides… Carcinogenic (cancer inducing) or teratogenic (birth defects) or mutagenic (genetic alteration) Biological impurities – live pathogens & worms
- 10. Nature of pollutants Biodegradable organics Easily decomposableby MO or other agents Starch, glucose… Refractory organics Resist biodegradation Phenols, surfactants, oils Putrifiable materials Emit foul odour during decomposition Garbage, slaughter house wastes.. Inert materials Unchanged by P/ C/ B action Small stones POP (Persistent Organic Pollutants) Chemicals that persist in the environment Pesticides, dioxins, furans, PCB..
- 11. Important pollution parameters pHMeasure of acidity or alkalinity EC EC is a measure of the amount of dissolved salts present in the solution TDS (Total Dissoved Solids) Fraction of solids dissolved in a given volume of water TSS (Total suspended solids) Fraction of solids that remain suspended in water (solids that neither settle nor float)
- 12. Important pollution parameters DOAmount of oxygen dissolved in water BOD oxygen required by bacteria for stabilizing decomposable organic matter COD oxygen required for the oxidation of oxidisable organic and inorganic matter
- 13. Effect of wastewater– Water Colour • Reduces use of water – bath, swim.. • Reduces light penetration • Stains cloths • Some colouring agents carcinogenic pH • Acidic or alkaline effluents affect living organisms in water • Induce leaching of chemicals SS (suspended solids) Increases turbidity of water Dissolved organics • Increases the BOD or COD • Oxygen depletion – dead pond (if severe)
- 14. Dissolved inorganics • Increases EC,hardness, turbidity • Affects cooking, washing and bathing • Unfit for irrigation if concentration is severe Toxic chemicals • Cr, Hg, As, pesticides, dyes, chemicals • Affect fishes and other aquatic organisms • Biomagnification / Bioaccumulation Ground water contamination • Excess salts leach down to reach groundwater (aquifer) • Major problem in parts of Vellore, Tirupur, Erode, Dindigul, Cuddalore districts Effect of wastewater – Water
- 15. BIO MAGNIFICATION /BIO AMBLIFICATION
- 16. Physical changes • Soil becomesacidic or alkaline • Salt rich or sodium rich soils • Porosity, Infiltration, bulk density, hydraulic conductivity Chemical changes • pH • EC • BOD and COD • Salt content Biological changes • Soil microorganisms • Earthworms • Plants affected • Other soil organisms Effect of wastewater – Land
- 17. Humans & fishes • Humans,fishes and other aquatic organisms affected • Cancer inducing (carcinogenic) • Birth defects (teratogenic) • Cr, As, Cd, Hg… Bio- accumulation/ Bio- magnification • A chemical may enter in to the body of an organism (eg. Fishes in a pond – 1g) • When a bird eats 5 fishes, then the chemical enters the bird – 5g • Increased concentration of chemicals at successive trophic levels is BA/ BM Effect of wastewater – organisms
- 18. LC 50 •Lethal Concentration • concentration of a chemical in air exposed for 4hr to kill 50%of population • Acute toxicity LD 50 • Lethal Dose • Concentration of the chemical at which 50% of population is killed in a single oral administration • Acute toxicity LT 50 •Time taken for a chemical to kill 50% of the population Acute toxicity Effect of wastewater – organisms
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- 22. Water borne diseases Cholera Amoebicdysentery Amoebiosis Hepatitis A Typhoid Malaria Shigellosis Giardiasis
- 23. Water treatment isnot the best option… Prevention of pollution is the solution… Use water judiciously March 22: World Water Day 2013 theme: International Year of Water co-operation Water for life decade: 2005-2015