Water
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This document discusses environmental factors that impact human health, with a focus on water. It describes different water sources like rain, surface water, ground water and their potential impurities. Large and small-scale water purification methods are outlined, including slow sand filtration, rapid sand filtration, chlorination and household purification techniques. The key roles of water in transmitting diseases and the importance of access to safe drinking water are emphasized.
Water
- 1. ENVIRONMENT AND HEALTH DR MARIYA AMIN QURIESHI LECTURER Community Medicine, GMC Srinagar
- 2. ENVIRONMENT External factors- living and non-living, material and non-material- which surrounds man.
- 3. COMPONENTS PHYSICAL- BIOLOGIC- SOCIAL- The key to mans health lies largely in his environment
- 4. WATER AIR NOISE RADIATION HOUSING METEOROLOGICAL ENVIRONMENT DISPOSAL OF SOLID WASTE MEDICAL ENTOMOLOGY
- 5. WATER
- 6. SAFE AND WHOLESOME WATER WATER REQUIREMENTS 150 TO 200 LITRES PER CAPITA USES
- 7. SOURCES OF WATER SUPPLY RAIN SURFACE WATER Impounding reservoirs Rivers and streams Tanks, ponds and lakes GROUND WATER Shallow wells Deep wells Springs
- 8. RAIN WATER PUREST FORM SOFT IMPURITIES-
- 9. SURFACE WATER IMPOUNDING RESERVOIRS Artificial lake Good quality Soft water IMPURITIES- Impurities from catchment area Algal growth
- 10. RIVERS Turbid in rainy season Impurities- bacterial count is very high SELF- PURIFICATION- Dilution, sedimentation, oxidation, sunlight, plant life. River water needs purification before it can be used for drinking purposes.
- 11. TANKS Most often contaminated. Needs purification Highly dangerous source of drinking water even at the best of times.
- 12. SEA WATER HIGH SALT CONTENT (3.5%) Demineralization and desalting
- 13. GROUND WATER Cheapest and most practical means of providing water. Superior- pathogen free, continuous supply, need no treatment, least possibility of contamination. Disadvantages- high mineral content, lifting arrangement. Shallow well and Deep well Dug well and tube well Step Well
- 14. WELLS Shallow and deep well Shallow well Deep well Porous strata Impervious strata Porous strata Impervious strata
- 15. SANITARY WELL Location- higher level, 15m away from source of contamination, user distance within 100 m. Lining- brick, 6m deep, 60-90cm above ground level. Parapet- 70-75 cm Platform- cement, 1m Drain Coverings Hand pump Consumer responsibility Quality
- 17. WATER POLLUTION
- 18. Sources Sewage Industrial and trade waste Agricultural pollutants Physical pollutants
- 19. 1. Water borne diseases Viral- Hepatitis A &E, polio, rotavirus diarrhea Bacterial- typhoid and paratyphoid fever, bacillary dysentry, E.coli diarrhea, cholera. Protozoal- Amoebiasis, giardiasis. Helminthic- roundworm,threadworm, hydatid disease.
- 20. 2. Water-associated diseases Behaviour- associated diseases Snail- Shistosomiasis Cyclops- Guineaworm, fish tapeworm Leptospirosis Mineral- associated diseases Dental caries, Dental and skeletal fluorosis Effluent-associated diseases Cyanosis(methhemoglobinemia) Methyl mercury (Minamata Disease)
- 21. 3.Water washed diseases Scabies, trachoma,conjuctivitis. 4. Water based diseases Malaria ,filaria, onchocerciasis.
- 22. WATER POLLUTION LAW Water (prevention and control of pollution) Act 1974
- 23. PURIFICATION OF WATER Large scale Small scale
- 24. LARGE SCALE PURIFICATION STORAGE Physical Chemical Biological FILTRATION Slow sand filters Rapid sand filters DISINFECTION
- 25. SLOW SAND FILTERS Elements 1. Supernatant water 2. Graded sand 3. Under-drainage system 4. Filter control valve Schmutzdecke Filtration rate= 0.1-0.4m3 /m 2 /hr sa Underdrainage system Venturi meter Raw water 1-1.5m outlet Vital layer 2-3cm inlet Sand bed 1m
- 26. RAPID SAND FILTERS II Rapid mixing III Flocculation IV Sedimentation V Filtration River I Coagulation (Alum) Mixing Chamber (5min) Flocculation chamber (30min) Sedimentation tank (2-6hrs) Clear water storage Water Under-drains Sand bed 5-15m 3/m2 /hr Consumption c h l o r i n e
- 27. Rapid sand filter Slow sand filter Little space 5-15m 3/m2 /hr 0.4-0.7 mm Chemical coagulation and sedimentation Backwashing Highly skilled Removal of color and turbidity is good Removal of bacteria 98- 99% Large area 0.1-0.4m3 /m 2 /hr 0.2-0.3mm Plain sedimentation Sand scraping Less skilled Removal of color and turbidity is fair Removal of bacteria 99.9-99.99%
- 28. DISINFECTION CHLORINE SATISFIES ALL THE ATTRIBUTES OF AN IDEAL DISINFECTANT IDEAL DISINFECTANT KILLING POWER CHEAP,HARMLESS TIMELY ACTION APPLICABILITY MONITORING ACCEPTABILITY DETECTABILITY SUSTAINIBILITY
- 29. AGENTS Chlorination Ozonation Ultraviolet irradiation
- 30. CHLORINATION CHLORINE COAGULATES ORGANIC MATTER BY OXIDATION POWERFUL GERMICIDAL ACTION OXIDISES IRON AND MANGANESE ALGAECIDE ACTS WITHIN NORMAL pH OF WATER ELIMINATES OBJECTIONABLE COLOUR, TASTE AND ODOUR OF WATERRESIDUAL ACTION Chlorine has no effect on bacterial spores, protozoal cysts and helminthic ova except in high doses. Viral agents like Hepatitis and Poliomyelitis are also resistant to chlorine in normal doses.
- 31. ACTION OF CHLORINE H2O + Cl2 HCl + HOCl HOCl H+ + OCl- Neutralized Disinfecting property Minor action
- 32. PRINCIPLES OF CHLORINATION Observe the quality of water Satisfy chlorine demand. Ensure adequate contact period- A free residual chlorine-0.5ppm (mg/L) appears after contact period of 30 min
- 33. METHODS OF CHLORINATION Chlorine gas Chloramines Perchloron(HTH) Patersons Chloronome is used for measuring, regulating and administering gaseous chlorine to water supplies.
- 34. TYPES OF CHLORINATION PLAIN CHLORINATION PRECHLORINATION-0.1-0.5ppm POST CHLORINATION DOUBLE CHLORINATION SUPERCHLORINATION-0.5-0.7ppm DECHLORINATION- Sod.bisulphate,sod.thiosulphate,Sod.sulphite BREAKPOINT CHLORINATION
- 35. BREAKPOINT CHLORINATION Formation of Chloro- organic and chloramines Destruction of chlorine Formation of free chlorine by reducing C D compounds B Destruction A of chloro-organic and chloramines 0 0.1 0.5 0.7 1.0 de R S I D U A L C H L O R I N E Combined residual Free residual Combined residual Chlorine Added (ppm)
- 36. TEST FOR CHLORINATION ORTHOTOLIDINE TEST- Color change ( yellow) Free chlorine- 10sec Residual chlorine+ free chlorine -15 min ORTHOTOLODINE- ARSENITE (OTA) TEST
- 37. PURIFICATION OF WATER ON SMALL SCALE HOUSEHOLD PURIFICATION DSINFECTION OF WEL Horrocks apparatus Double pot method
- 38. HOUSEHOLD PURIFICATION BOILING CHEMICAL DISINFECTANTS- Bleaching powder Chlorine solution High test hypochlorite Chlorine tablets Iodine Pot. Permanganate FILTERATION- 損 Chamberland filter 損 Berkefeld filter 損 Katadyn filter