A.SATEESH Chemist, State Level Laboratory RWS&S Department

Transcription

1 A.SATEESH Chemist, State Level Laboratory RWS&S Department

2 Blue water = good quality water

3 Green water = nutrient-enriched water

4 Brown water comes from swamps & forests

5 Water pollution from poor land use practices

6 Algal bloom

7 Weed infestation of water bodies is driven by nutrient enrichment

8 Water hyacinth in lakes and rivers due to pollution -chokes fish landing sites, etc.

9 Water is a common chemical substance that is essential for survivals of all known forms of life. gaseous state solid state-ice liquid state Water refers only to its liquid state, but it has also a solid state-ice and gaseous state vapour. 9

10 An important feature of water is its polar nature. Water is a dipole molecule. Water is a good solvent due to its polarity. Due to this quality, to dissolve readily as many as salts in it, its purity changes and here the problem of water quality starts for human consumption point of view. 10

11 Earth s Total Available Water Oceans Glaciers Ground water Surface water Soil moisture Atmosphere % 2.15 % % % % %

12 PHYSICAL, CHEMICAL & BACTERIOLOGICAL CONTAMINATION OF WATER AND WATER QUALITY STANDARDS

13 contamination Geological Human activities. Organic waste Industrial waste

14 A Person dying of thirst?? There may be a rare a case! But As many as 13 million people die every year. The world over. Cause they drink water. Contaminated Water! 14

15 Contamination? Bacteriological Contamination Chemical Contamination 15

16 CHEMICAL CONTAMINATION NATURAL MAN MADE 16

17 17 Man Made

18 Safe drinking water Free from pathogenic organisms Clear Not saline Free from offensive taste or smell Free from compounds that may have adverse effect on human health Free from chemicals that cause corrosion of water supply systems

19 WATER QUALITY PARAMETERS Physical parameters Chemical Bacteriological

20 BUREAU OFINDIAN STANDARDS IS Parameters Desirable limit Permissible limit Colour Hazen unit 5 25 Turbidity-NTU 5 10 ph Hardness (as CaCO3)mg/l TDS

21 BUREAU OFINDIAN STANDARDS IS Parameters Desirable limit Permissible limit Nitrate mg/l Chloride mg/l Fluoride mg/l Arsenic mg/l Aluminium mg/l

22 Colour May be due to the Presence of organic matter, metals (iron, manganese) or highly colored industrial waste Aesthetically displeasing Desirable that drinking water be colorless Desirable limit, 5 Hazen unit Permissible limit 25 Hazen Unit

23 Taste and Odour Mainly due to organic substances,,biological activity, industrial pollution Taste buds in the oral cavity specially detect inorganic compounds of metals like magnesium, calcium, sodium, copper, iron and zinc Water should be free from objectionable taste and odour.

24 ODOUR Source of odours can be due to Presence of Hydrogen Sulphide in water due to septic sewage, chemical and biological reduction of sulphates Contamination by organic matter from sewage, pit toilets, soils and vegetation Contamination by chemicals from industrial sources or treatment process Growth of algae, protozoa and fungi in water Contact with painted surfaces

25 TASTE People have different sensitivities to taste Taste Possible sources Salty High chloride & Na salts Bitter Magnesium sulphate Astringent Hard water,iron & Mn Sweet Organic matter Mettalic Fe,Mn,Cu & Zn Sharpness Chalk derived waters Ca Co3 & Co2 Musty Fungi

26 Turbidity Caused by suspended matter High level turbidity shield and protect bacteria from the action of disinfecting agents Disirable limit-5ntu should be below 1 NTU when disinfection is practiced Permissible limit-10ntu

27 ph It is the measure of hydrogen ion concentration Neutral water ph-7 Acidic water has ph below 7 Basic water has ph above 7 Desirable limit Beyond this limit the water will affect the mucous membrane and water supply system

28 Substances that change ph of water Acidic Industries Sugar 5 6 Distillery 3-4 Electro- Plating unit Pickle 2-3 Basic Paper 8 10 Textile Fertiliser Oil Refineries

29 Battery acids <1.0 Milk 6.7 Carbonated Beverages 2 4 Rain water 6.5 Lemon juice 2.3 Blood 7.5 Orange juice 4.2 Sea water 8.0 Ammonia solution 11.3 Vinegar Domestic sewage Ground water

30 HARDNESS Capacity of water for reducing and destroying the lather of soap It is total concentration of calcium and magnesium ions Temporary hardness Bicarbonates of Calcium and Magnesium Permanent hardness Sulphates, chlorides and nitrates of calcium and magnesium

31 Hardness contd 0 50 mg/l - soft mg/l - moderately hard mg/l - hard 300 above - very hard Surface water is softer than ground water Causes encrustations in water supply structures

32 ALKALINITY Capacity to neutralize acid Presence of carbonates, bi-carbonates and hydroxide compounds of Ca, Mg, Na and K Alkalinity = hardness, Ca and Mg salts Alkalinity > hardness - presence of basic salts, Na, K along with Ca and Mg Alkalinity < hardness neutral salts of Ca & Mg present

33 IRON One of the earth s most plentiful resource High iron causes brown or yellow staining of laundry, household fixtures Metalic taste, offensive odour, poor tasting coffee Cause iron bacteria Acceptable limit 0.3 mg / l

34 EXCESS IRON : EFFECT OF IRON BACTERIA Sliming of pipe 34

35 NITRATE Increasing level of nitrate is due to Agricultural fertilizers, manure, animal dung, nitrogenous material,sewage pollution (blue baby diseases to infants) Maximum permissible limit 45 mg / l as No3

36 NITRATE POISONING : BLUE BABY SYNDROME

37 NITRATE POISONING : BLUE BABY SYNDROME

38 CHLORIDE Causes Dissolution of salt deposit Discharge of effluents Intrusion of sea water Not harmful to human beings Regarding irrigation most troublesome anion Acceptable limit mg/l Max. Permissible limit 1000 mg/l

39 FLOURIDE Occurs naturally Long term consumption above permissible level can cause Dental fluorosis (molting of teeth) Skeletal fluorosis Acceptable limit 1 mg / l Maximum permissible limit 1.5 mg / l Remedy 1) De-fluoridation 2) Mixing Fluoride free water 3) Intake of vitamin C,D, calcium, antioxidants

40 FLOURIDE CAUSES Three types of Fluorosis 1. Dental Fluorosis 2. Skeletal Fluorosis 3. Non-skeletal Fluorosis

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42 ARSENIC Occur in ground water from arseniferous belt Industrial waste, agricultural insecticide High arsenic causes 1) various type of dermatological lesions, muscular weakness, paralysis of lower limbs, can also cause skin and lung cancer Acceptable limit 0.05 mg / l

43 ARSENIC POISONING THROUGH WATER 43

44 Chemical Parameters indicative of pollution NITRITE Presence of nitrite in water indicates pollution of water with organism derived from sewage or excreata Pure water do not normally contain nitrite Treatment: Effective disinfection with chlorine

45 Ammonical Nitrogen Presence of ammonia in water significant amount indicates pollution of water with sewage and some industrial effluents Uncontaminated waters the ammonia content will be normally less than 0.1mg/lit Treatment is Chlorination

46 Heavy Metals Present as mineral in soil and rocks of earth Human activities Battery Lead & Nickel Textile - Copper Photography Silver Steel production Iron

47 Pesticides Cancer Birth defects Blood disorder Nervous disorder Genetic damage

48 Essential bacteriological Standards Characteristics Number / 100 ml Treated water in distribution system Feacal coliform zero Total coliform not more than 10 Total coliform should not be detectible in two consecutive samples

49 RESIDUAL CHLORINE Chlorine added to water forms hypochlorite ions and hypochlorite acids Chlorine demand Quantity required for killing micro organisms and reacting with ammonia, organic compounds etc. Free residual chlorine To take care of post contamination Desirable 0.2 mg / liter

50 Common problems Visible effects Reasons Water turns black, smell Waste water Acidic taste Low ph Alkaline taste High ph Boiled Rice hard and yellow High Alkalinity White deposits on boiling Hardness

51 Common problems Visible effects Reason Iron taste, change in colour after exposure to atmosphere, change in colour of cloths, utensils Oily appearance on top of water body Iron Soap not lathering hardness Brownish black streaks on teeth `Fluoride Growth of Algae Nitrate, phosphate Fish kills Low ph less DO Salty taste chloride

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