Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Water resources managt

0 views

Published on

Water resources managt

  • Be the first to comment

Water resources managt

  1. 1. Hari Prasad Kafle Assistant Professor (Public Health) School of Health and Allied Sciences Pokhara University.
  2. 2.  Inorganic compound made up of 2 part of hydrogen and one part of oxygen.  Essential component for vitality animal and plant life.  Alma Ata Declarations on PHC1978: Water as basic element of Primary Health Care (An adequate supply of safe drinking water and basic sanitation).
  3. 3.  Free from pathogenic agents  Free from harmful chemical substances  Pleasant to taste, i.e. free from color and order, and  Useable for domestic propose
  4. 4. For drinking purpose: 2 liter/person/day
  5. 5. Domestic purpose: 150-200 liter/person/day
  6. 6. 1. Domestic uses; 2. Public purpose: cleaning streets; fire protection, etc. 3. Industrial purpose; 4. Agricultural purpose; 5. Hydropower production; 6. Other uses: fishing, tourism, swimming pool, ornamental ponds, transportation etc.
  7. 7.  Rainwater;  Surface water ◦ Impounding reservoir ◦ River and streams ◦ Tanks, Ponds and lakes  Ground water ◦ Sallow well ◦ Deep well ◦ Spring
  8. 8.  Prime source of all water  Purest water in the nature  Physically clear, bright and sparkling  Chemically very soft  Corrosive action on pipes due to softness  Bacteriological free from pathogenic organism  Contains atmospheric impurities while raining: acid rain
  9. 9.  Originates from rain water  Main source of water supply  Examples: river, tanks, lake, sea water  Types: 4 types ◦ Impounding reservoir ◦ River and streams ◦ Tanks, Ponds and lakes ◦ Sea water  High chances of contamination  Generally no useable without treatment
  10. 10.  Cheapest and more practical means providing water for small communities  Free from pathogenic organism  Usually requires no treatment  Supply even dry seasons  High mineral content e.g. Ca, Mg etc.  Requires pumping  Ground water includes ◦ Sallow well ◦ Deep well ◦ Spring
  11. 11. Particulars Shallow well Deep well Definition Taps water from above the first impervious layer Taps water from below the first impervious layer Chemical quality Moderately hard Much hard Bacteriologi cal quality Often grossly contaminated Tapes purer water Yields Usually goes dry in summer Provides a source of constant supply
  12. 12. Location 1990 2000 2005 2010 2015* Drinking Water Urban (%) 90 86 93 94 95 Rural (%) 43 71 79 78 72 Total 46 73 81 80 73 *Target MDG Source: Nepal Millennium Development Goals; Progress Report 2010.
  13. 13. Developmen t region Piped water Hand pump Well Spring water Other FDR 30.7 44 3.5 19.7 1.9 MWR 44.3 28.3 4.1 21.7 1.6 WR 59.8 27. 0.5 10.2 2.2 CR 45.4 39.4 5.4 6.5 3.4 ER 37.7 53.1 3.2 3.1 3 Nepal 45 39.1 3.6 9.6 2.7
  14. 14. Geographic region Piped water Hand pump Well Spring water Other Terai 16.1 78.2 4.3 0.9 0.5 Hill 71 3.3 3.3 17.5 4.9 Mountain 77.3 0.3 0 18.9 3.5 Urban 62.2 28.2 4.3 3.1 2.2 Rural 45.5 41.3 3.4 11 2.8 Nepal 45 39.1 3.6 9.6 2.7
  15. 15. Year Unit Water Supply Leakage (%) 1993/94 Th. l/day 64684 - 1994/95 Th. l/day 62379 - 1995/96 Th. l/day 63447 - 1996/97 Th. l/day 40150 - 1997/98 Th. l/day 32115 - 1998/99 Th. l/day 27011 - 1999/00 Th. l/day 31271 38 2000/01 Th. l/day 26644 37 2001/02 Th. l/day 9876 37 2002/03 Th. l/day 10552 37 2003/04 Th. l/day 11550 36 2004/05 Th. l/day 9580 37 2005/06 Th. l/day 26300 38 2006/07 Th. l/day 33500 37 2007/08 Th. l/day 230450 35
  16. 16.  Sewage,  Industrial and trade pollutants,  Agricultural pollutants,  Physical pollutants  Radioactive substances.
  17. 17.  Factories, power plants, sewage treatment plants, latrines that are classified as point sources, as they discharge pollution from specific locations.  Non-point sources of water pollution are scattered or diffuse, having no specific location for discharge and include runoff from farm fields and feedlots, construction sites, roads, streets and parking lots.
  18. 18. Pollutant Main source Effects Possible control Organic oxygen demanding waste Human sewage, animal wastes, decaying plant life, industrial waste Overload depletes dissolved oxygen in water: animal life destroyed or migrates away: plant life destroyed Provide secondary and tertiary waste water treatment; minimize agricultural runoff Plant nutrients Agricultural runoff, detergents industrial wastes inadequate waste water treatment Algal blooms and excessive aquatic plant growth upset ecological balances: eutrophication Agricultural runoff too widespread, diffuse for adequate
  19. 19. Pollutant Main source Effects Possible control Pathogenic bacteria & virus presence of sewage and animal wastes in water Outbreaks of such diseases as typhoid infectious hepatitis Provide secondary and tertiary wastewater treatment; minimize agricultural runoff Inorganic chemicals Mining manufacturing irrigation, oil fields Alter acidity, basicity, or salinity: also render water toxic Disinfect during waste-water treatment; stop pollutants at source
  20. 20. Pollutant Main source Effects Possible control Synthetic organic chemicals (plastic, pesticides) Agricultural manufacturing, and consumer uses Many are not biodegradable; chemical interactions in environment are poorly understood many poisonous Use of biodegradable materials; prevent entry into water supply at source Sediments Natural erosion, poor soil conservation practices in agriculture, mining construction Fill in waterways, reduce fish populations Put soil conservation practices to use
  21. 21. Pollutant Main source Effects Possible control Fossil fuels (oils particularly) Machinery, automobile wastes; pipeline breaks, offshore blowout and seepage, supertanker accidents, spills, and wrecks; heating transportation, industry; agriculture Vary with location, duration, and type of fossil fuel; potential disruption of ecosystems; economic, recreational, and aesthetic damage to coasts Strictly regulate oil drilling, transportation, storage; collect and reprocess engine oil and grease; develop means to contain spills
  22. 22. A. Biological: water borne disease B. Chemical: organic acids, Detergents, heavy metal show long term effect. C. Water associated disease: Malaria, JE, filaria, dental carries, CHD, conjunctivitis, trachoma etc.
  23. 23.  Viral: Viral hepatitis A, Hepatitis E, Poliomyelitis, rotavirus diarrhoea etc.  Bacterial: typhoid & paratyphoid fever, bacillary dysentery, Cholera, Esch. Diarrhoea etc.  Protozoal: amoebiasis, giardiasis.  Helminthic: round worm, thread worm, hydiatid disease.  Snail: schistosomiasis.  Cyclops: guinea worm, fish tape worm.
  24. 24. Oh! how big; Could we digest it? Let’s try!
  25. 25. Hari Prasad Kafle Assistant Professor (Public Health) School of Health and Allied Sciences Pokhara University.
  26. 26. The guideline for drinking water quality recommended by WHO (1993 and 1996) relate to following variables: 1. Acceptability aspects 2. Microbiological aspects 3. Chemical aspect 4. Radiological aspects
  27. 27. A. Physical parameters 1.Turbidity: < 5NTU (Nephelometric Turbidity Unit) 2.Colour: free from colour; upto 15 TCU (True Colour Unit) 3.Taste and odour: pleasant to taste and no odour 4.Temperature: cool water is more palatable.
  28. 28.  Chloride: upto 200mg/liter  Calcium: 100-300mg/liter  Ammonia: <0.2mg/liter  Hydrogen sulphide: 0.05- 0.1mg/liter  Iron: 0.3mg/liter  Sodium: 200mg/liter  Sulphate: <250mg/liter  Zinc: 0.3mg/liter  Manganese: <0.1mg/liter  Cupper: <1mg/liter  Aluminum: 0.2mg/liter  PH value: 6.5-8.5  Dissolved oxygen: no guideline  Total dissolved solids: <100mg/liter B. Inorganic constituents
  29. 29. 1. Bacteriological indicator a. Coliform organism b. Faecal streptococci c. Cl. Perfringens 2. Virological aspects 3. Biological aspects a. Protozoa b. Helminthes c. Free living organism
  30. 30. a. Coliform organism: Several region for choosing coliform indicators of faecal pollution are: i. Easy to culture; even single E. coli can be culturable in 100 ml of water. ii. They are foreign to the water and generally not present to water. iii. They are present in greater number (normal human can excrete 200-400 billion E. coli) iv. They resist natural purification v. They live longer than other pathogens
  31. 31. b. Faecal streptococci: It is the confirmatory test for faecal contamination. Some times (very rarely) E. coli doesn't present in water but if present streptococci than there is 100% faecal contamination. c. Clostridia: the spores of clostridia are highly resistance against the disinfection. If only one spore of clostridia is present in water; it shows faecal contamination taken place in remote time.
  32. 32.  Drinking water should be free from any virus infectious to man. At the level of 0.5% FRC all pathogenic virus will be destroyed including hepatitis A. when bleaching powder mix with 2.5 gram mix with 1000ml of water then Free Residual Chlorine (FRC) will be 0.7%/liter in water.
  33. 33. a. Protozoa: Entomoba Histolytica, Giardia Lambia both should not present in drinking water and both slow and rapid sand filter are effective In remaining protozoa. b. Helminthes: Round worm, Flat worm etc. Even a single egg/larva can produce disease in man; should not in water. Guinea worm and schistosomiasis is hazard of unpiped water can be protect from source protection.
  34. 34. c. Free living organism: free living organism that occurs in water supply include fungi, algae etc. which interfere colour, odour, taste, turbidity etc.
  35. 35. A. Inorganic chemicals B. Organic constituents
  36. 36.  Arsenic: 0.01mg/liter  Cadmium: 0.003mcg/liter  Chromium: 0.05mg/liter  Cyanide: 0.07mg/liter  Fluoride: 1.5mg/liter  Lead: 0.01mg/liter  Mercury: 0.001mg/liter  Nitrate (NO3): 50mg/liter  Nitrite (NO2): 3mg/liter  Selenium: 0.01mg/liter
  37. 37. Organic constituents Upper limit of concentration (Mcg/L) Chlorinated alkanes Carbon tetrachloride 2 Dichloromethane 20 Chlorinated ethane Vinyl chloride 55 1.1-dichloroethene 30 1.2-dichloroethene 50
  38. 38. Organic constituents Upper limit of concentration (Mcg/L) Aromatic hydrocarbon Benzene 10 Toluene 700 Xylems 500 Ethyl Benzene 300 Styrene 20 Benzolalpyrene 0.7
  39. 39. Organic constituents Upper limit of concentration(Mcg/L) Aldrin/dieldrin 0.03 Chloride 0.2 DDT 2 Hepatochlor epoxide 0.03 Hexachlorobenzene 1 Lindane 2 Methoxychlor 20 Pentachlorophenol 9
  40. 40.  Gross α activity = 0.1 Bq/L (Becquerel)  Gross β activity = 1.0 Bq/L
  41. 41. Thank you!
  42. 42. Hari Prasad Kafle Assistant Professor (Public Health) School of Health and Allied Sciences Pokhara University.
  43. 43. Don’t be puzzled by problems, what ever they may be. Always face them as if they are examinations you have to pass.
  44. 44. The activities that ideally should be included in the surveillance function are: 1. Approval of new sources (including private- owned supplies) 2. Watershed protection
  45. 45. 3. Approval of the construction and operating procedures of waterworks, including:  Disinfection of the plant and of the distribution system after repair or interruption of supply.  Periodic flushing programs and cleaning of water storage facilities.  Certification of operators,  regulation of chemical substances used in water treatment  cross connection control, back-flow prevention and leak detection control;
  46. 46. 4. Sanitary survey; 5. Monitoring programs, including provision for central and regional analytical laboratory services; 6. Development of codes of practice for well construction, pump installation and plumbing 7. Inspection quality control in bottled-water and ice manufacturing operations.
  47. 47. 1. Sanitary survey: ◦ On-the-spot inspection ◦ Evaluation by a qualified person. ◦ Purpose: detection and correction of faults and deficiencies.
  48. 48. 2. Sampling: ◦ Carried out by competent and trained personnel. ◦ Sample for physical and chemical examination: ◦ Clean glass stoppered bottles (known as “Winchester Quart bottles”) ◦ Capacity of bottle: less than 2 liters. ◦ Sample for biological examination: ◦ Collected in clean sterilized bottles made of neutral glass. ◦ Capacity: 200-250 ml
  49. 49. 3. Bacteriological Surveillance: a. Presumptive Coliform Test: i. Multiple tube method  Tube-Mc Conkey’s Lactose Bile Salt Broth with bromcresol purple  Incubated for 48 hours.  Most probable number (MPN) is obtained from the number of tubes showing acid and gas in 100ml water. ii.Membrane filtration technique  Filtered through a membrane specially made of cellulose ester.  Obtained result within 20 hours.
  50. 50. 3. Bacteriological Surveillance: a. The detection of faecal streptococci and cl. perfringens b. Colony count  Count on nutrient agar (yeast extract agar) at 37 deg C and 22 deg C.
  51. 51. 4. Biological examination  Microscopic organism: algae, fungi, yeast, protozoa, rotifers, crustacean, minute worms, etc. 5. Chemical surveillance  Basic Test: PH, colour, turbidity, chlorides, ammonia, residual chlorine  Include analysis for toxic metal, pesticide, persistent organic chemical and radioactivity.
  52. 52. 55
  53. 53. No matter how handsome (beautiful) you may be, you will be judged by your words and actions. Always express sweet & sound words and positive action & efforts to sustain your achievements.
  54. 54.  Water purification is defined as the process of removing all those substances, whether biological, chemical or physical, which are potentially dangerous or undesirable in water supply for human and domestic use.
  55. 55. 1.To remove pathogenic organisms & consequently to prevent waterborne disease. 2.To remove substance which impart color, taste or odor to the water. 3.To remove excess or undesirable chemicals or minerals from the water. 4.To regulate essential elements or chemicals that may be in excess or lacking in a certain water supply. 5.To remove excess/undesirable dissolved gasses.
  56. 56.  In order to achieve these objectives, water treatment procedures may involve a simple physical process such as sedimentation, or complex physio-chemical and biological processes, depending upon the undesirable elements or substance present in the raw water.
  57. 57.  Preliminary planning of water treatment plant work should include a comprehensive study of the catchments area in terms of: 1. Size, topography, population division and surface geology 2. Source of pollution 3. Sewage treatment facilities 4. Raw water characteristics including physical, radiological, chemical, bacteriological and biological characteristics
  58. 58. 5. Rainfall and run-off data 6. Evaporation rate 7. Anticipated water supply requirement, (minimum, maximum and average); and 8. Other items of importance in providing a safe water supply, adequate in amount for the community in question.
  59. 59.  Purification of water in large scale ◦ Rapid sand filter ◦ Slow sand filter  Purification of water in small scale ◦ Boiling ◦ Chemical disinfection ◦ Filtration ◦ Well disinfection
  60. 60.  The component of water purification system comprise one or more of the following measures: i. Storage ii. Filtration iii.Disinfection
  61. 61.  As a result of storage, considerable amount of purification takes place.  Physical: 90% suspended particles settle down in 24 hours by gravity.  Chemical: aerobic bacteria oxidize the organic matter present in the water with aid of dissolved oxygen.  Biologically: bacterial count drops by 90% by storage of water for 5-7 days.
  62. 62.  Second stage of purification  98-99% of bacteria are removed by filtration.  Two types of filtration procedure are used for large scale water purification.  Rapid sand filter “Mechanical filter”  Slow sand filter “Biological filter”
  63. 63.  The oldest type, this type of filter has been use traditionally and has been effective in the past.  The rate of filtration very low than rapid sand filter.  Some of these filters are still in use in some parts of the Far East, Europe, and North America.
  64. 64.  It is very well suited to rural areas, because it does not require skilled workers to construct or maintain, and the costs of operation and maintenance are reasonable.
  65. 65.  In this system, the process of filtration is a combination of physical straining, (e.g. sedimentation and biological activities), such as the growth of micro-organisms which takes place in the topmost layer of the sand grains soon after filter is in operation.  This microbial growth in the sand grain forms a sticky gelatinous coat in the top layers of the filter, and is called schmutzdecke, a German term meaning "cover of filth".
  66. 66. a.Raw water b.A bed of graded sand c.An under drainage system d.A system of filter control valve.
  67. 67.  The raw water to be filtered should be as clean as possible, and turbidity should be less than 50 mg/l.  The depth of raw water is about 1-1.5 meter.  The raw water is evenly distributed over the graded sand to a depth from 90 cm to 1.20 meters (36 inches to 48 inches).
  68. 68.  The depth of the filter sand is one of the most important determinants of the efficiency of flirtation.  The effective diameter of sand is about 2- 3mm.  The graded sand is laid on the top of the graded gravel to a minimum depth of 60 cm (2ft), optimum 90 cm (3ft), and a maximum depth of 1.20 meters (4ft).
  69. 69.  Water percolates through a sand bed very slowly taking time 2 hours or more to pass taking number of purification process: mechanical straining, sedimentation, absorption, oxidation and bacterial action.  The designated rate of filtration is about 0.1- 0.4m3/m2/hour.
  70. 70.  Crushed round gravel of fixed sizes, varying from about 5 cm to 1.5 mm is laid around and over the under drains, the largest size at the bottom and the smallest at the top.  The depth of the graded gravel should be at least 30 cm (12 inches), and preferably 45 cm (18 inches).
  71. 71. 000000000000000000000000000000000000 00000000000000000000000000000000000 00000000000000000000000000000000000 00000000000000000000000000000000000 oooooooooooooooooooooooooooooooooooooooooooooooo oooooooooooooooooooooooooooooooooooooooooooooooo oooooooooooooooooooooooooooooooooooooooooooooooo oooooooooooooooooooooooooooooooooooooooooooooooo oooooooooooooooooooooooooooooooooooooooooooooooo ……………………………........................................................................ ...................................................................................................... ...................................................................................................... ...................................................................................................... ...................................................................................................... ...................................................................................................... Filter sand Course sand Finegravel Course gravel
  72. 72.  Perforated pipes, or drainpipes with open joints, with side joints (laterals) connected to the main drain, are laid at the bottom of the filter bed or tank to collect filtered water.
  73. 73.  Equipped with certain valve and devices which are incorporated in the outlet pipe system.  The purpose is to control the rate of filtration.  An important component is a ‘Venturi meter’ which measure the bed resistance or ‘loss of head’.
  74. 74.  The rate of filtration decreases gradually due to clogging, it indicates the necessity for cleaning, filtration is stopped, and the topmost layer of the sand is removed by careful scraping.  Each scraping usually removes from 5 cm to 10 cm depth of sand.
  75. 75.  The sand that has been scraped off is stored and washed several times.  The cleaned sand is then replaced over the bed of the filter, to maintain the minimum depth.  The cleaning interval varies from about three weeks to several months depending on the quality of the raw mater to be filtered.
  76. 76.  First installed in USA in 1885.  Useful for industrialized countries having metro and mega cities.  Supply large amount of water for populations.  Occupies very small space for plant installation.
  77. 77. Mixing Chamber Flocculation Chamber Sedimentation Tank Filter Clean water storage Alum Chlorine Consumption
  78. 78. 1. Screening 2. Coagulation 3. Rapid mixing 4. Flocculation 5. Sedimentation 6. Filtration 7. Chlorination 8. Supply
  79. 79.  To protect the main units of a treatment plant and to aid in their efficient operation, it is necessary to remove any large floating and suspended solids that are often present in the inflow.  These materials include leaves, twigs, paper, rags and other debris that could obstruct flow through a plant or damage equipment in the plant.
  80. 80.  The raw water is first treated with a chemical coagulants such as alum (Aluminum Sulphate) in the varying dose of 5-40mg/liter depending up on the colour, turbidity, temperature and PH value of water.
  81. 81.  The treated water is then subjected to violent agitation in a mixing chamber for a few minutes.  This allows a quick and through dissemination of alum through out the bulk of water.
  82. 82.  Intense mixing of coagulant and other chemicals with the water.  Generally performed with mechanical mixers Chemical Coagulant
  83. 83.  Flocculation involves a slow and gentle stirring of the treated water in a flocculation chamber for about 30 minutes.  This result in formation of thick, copious, white flocculent precipitate of aluminum hydroxide.
  84. 84. Water coming from rapid mix. Water goes to sedimentation basin.
  85. 85.  The coagulated water is now led into sedimentation tanks where it is detained for periods varying from 2-6 hours when the settle down in the tank.  At least 95% of the flocculent precipitate needs to be removed before the water is admitted into the rapid sand filter.
  86. 86. Water coming from flocculation basin. Water goes to filter. Floc (sludge) collected in hopperSludge to solids treatment
  87. 87.  The partly clarified water is then subjected to rapid sand filter.  Filter is a process where the suspended matter is separated or purified by passing it through a minute porous material or medium.  This medium may be sand, diatomaceous earth, or a finely woven fabric.
  88. 88. 1.To produce clear sparkling water (reduce turbidity) 2.To reduce number of micro-organisms 3.To minimize the contaminants which cause undesirable taste and odor 4.To remove any suspended solid in water.
  89. 89.  Each unit of filter bed has a surface of about 80- 90 m sq (about 900 sq feet).  Sand bed: Sand is the filtering medium. The effective size of the sand particles is about 0.4- 0.7mm. The depth of the sand bed is usually about 1 meter.  Gravel bed: Below the sand bed is a layer of graded gravel of 30-40 cm. The gravel supports the sand bed and permits the filtrated water to move towards the under drain.
  90. 90.  The depth of water on the top of the water is about 1-1.5 meter.  The rate of filtration is 5-15cubic m3/m2/hour.  Filtration removes “alum-floc” not removed by sedimentation.
  91. 91. Water coming from sedimentation basin. Anthracite Sand Gravel (support media) Water going to disinfection
  92. 92.  It is cleaned by means of its back-washing system.  In this filter, the sand layer gets clogged quickly because of the high rate of filtration and deposition of flocs among the sand grains.  The filter is washed at intervals varying between 20 hours and 5 days, depending on the degree of turbidity of the raw water.
  93. 93.  Washing of the filter sand is achieved by forcing clean water up through the sand, by reversing the flow of water pressure.  The forced upward flow agitates the sand layers and washes away the clogging materials to a drain system, which totally gets rid of the dirt into a final disposal drain.  The washing process is normally accomplished in five to fifteen minutes.
  94. 94. 10 3
  95. 95. Particular Rapid sand filter Slow sand filter Space Occupies very little space Occupies large space Rate of filtration 200 mgad 2-3mgad Effective size of sand 0.4-0.7mm 0.2-0.3 mm Preliminary treatment Chemical coagulation and sedimentation Plane sedimentation Washing By back washing By scraping sand bed
  96. 96. Particular Rapid sand filter Slow sand filter Washing By back washing By scraping sand bed Operation Highly skilled Less skilled Loss of head allowed 6-8 feet (2.25m) 4 feet (1.5m) Removal of turbidity Good Good Removal of colour Good Fair Removal of bacterial 89-99% 99.9-99.99%
  97. 97.  Simple to construct and operate  The cost of construction is cheaper than rapid sand filter  physical, chemical and bacteriological quality is very high.  Reduced total bacterial counts by 99.9-99.99% and E coli counts by 99-999.9%.
  98. 98.  An outdated method  Occupies large space  Very low rate of filtration  Not suitable for mega and metro cities
  99. 99.  Deal directly with raw water  No preliminary storage of water is required  Filter beds occupies less space  Rapid filtration rate (40-50 times grater than slow sand filter)  Flexibility in operation.  Suitable for large populations.
  100. 100.  Required highly skilled manpower  High maintenance cost  Required frequent cleaning/washing
  101. 101.  A sanitary well is one which is properly located, well constructed and protected against contamination with a view to yield a supply of safe water.
  102. 102.  Location  Lining  Parapet  Plate form  Drain  Covering  Hand pump  Consumers responsibility  Quality
  103. 103.  At least 50 feet from source of contamination  Appropriate distance from home ( not more than 100 meter)
  104. 104.  Cemented ring or made up of stone or break lining up to the depth of at least 20 feet.  2-3 feet above the ground level
  105. 105.  28 inches above the ground level
  106. 106.  Cement concrete plat form at least 1 m (3 feet) in all directions.  Sloping towards the drain
  107. 107.  Cemented drain around the platform to drain waste water
  108. 108.  The top of the well should be covered by a cement concrete cover to protect against contamination.
  109. 109.  The well should be equipped with hand pump for lifting the water in sanitary manner.  Electronic device can be applied for lifting the water.
  110. 110.  Protection and maintenance  Time to time disinfection
  111. 111.  Physical, chemical and bacteriological quality should be measured in time to time by taking sample.
  112. 112. Chemical or agent used for water disinfection meet following criteria: 1.Capable for destroying pathogenic organism 2.Should not leave toxic product after chemical reaction 3.Reasonable price, simple to use, safe and easy availability 4.Leaving residual concentration to deal with possible recontamination. 5.Rapid, practical & simple analytical technique.
  113. 113.  Chlorine formula  Ozonization  Ultraviolet radiation
  114. 114.  Most commonly used method for large and small scale purification of water  It is supplement not a substitute of filtration.  Chlorine kills pathogenic bacteria but it has no effect on spores and certain virus like polio and hepatitis virus.
  115. 115.  Chlorine kills pathogenic bacteria but it has no effect on spores and certain virus like polio and hepatitis virus.  It also oxidizes iron, manganese and hydrogen sulphide.  It also destroys some taste and odour producing constituents.  It controls algae and slime organisms and aids coagulation.
  116. 116.  When chlorine is added to water, there is formation of hydrochloric and hypochlorous acids.  The hydrochloric acid is neutralized by the alkalinity of water.  The hypochlorous acid ionizes to form hydrogen ions and hypochlorite ions.
  117. 117. H2O + CL2 HCL + HOCL HOCL H+ + OCL-  The disinfecting action of chlorine is mainly due to the hypochlorous acid and to small extends due to hypochlorite ion.  Chlorine acts best when the PH value of water is about 7.
  118. 118. 1.Water to be chlorinated should be clear and free from turbidity. 2.Chlorine demand should be estimated exactly. 3.Contact period should be at least one hour to kill bacteria and viruses. 4.Minimum recommended free residual chlorine should be 0.5/liter. 5.Chlorine dose should include chlorine demand and chlorine amount to produce 0.5mg/L FRC.
  119. 119.  Chlorine Demand: The amount of chlorine that is needed to destroy bacteria and to oxidize all the organic matters and amonical substances present in the water.  Chlorine Dose: the total amount of chlorine that is needed to meet the chlorine demand and to produce 0.5mg/liter free residual chlorine.
  120. 120.  Break point: The point at which chlorine demand of water is meet is known as break point. If further chlorine is added then free residual chlorine begins to start in water.  Contact period: The period from a point when free residual chlorine starts appearing in water to the period from which can be consumed is known as contact period. It should be at least hour.
  121. 121.  Free Residual Chlorine: the concentration of free chlorine in water after 1 hour of contact period is known as free residual chlorine. The minimum recommended FRC is 0.5mg/L.
  122. 122. Chlorine Demand Chlorine dose Contact Period Break Point FRC 0.5 mg/L ConcentrationofChlorine Combined chlorine Mono: diachloramine 2:1
  123. 123.  NH3+Cl2= NH2Cl (Monochloramine)  NH2Cl+CL2= NHCL2 (Dichloramine)  NH2Cl+NHCL2= N2O (nitrous oxide)
  124. 124.  Ozone is relatively unstable gas.  Powerful oxidizing agent  Eliminates undesirable colour, odour, taste and removal of all chlorine from water.  Strong virucidal effect  > 1000 cities practicing  Appropriate in combination with chlorine  Dose 0.2-1.5mg/Liter.
  125. 125.  This method of water disinfection involves the exposure of a film of water up to about 120mm thick to one or several quartz mercury vapour arc lamp emitting UV radiation at a wave length of 200-295 Nanometer.

×