Analysis of water pollution presentaion by m.nadeem ashraf


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Analysis of water pollution
Muhammad Nadeem Ashraf
University of poonch, Rawalakot.

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Analysis of water pollution presentaion by m.nadeem ashraf

  1. 1. SES_311 Introduction to soil and environmentDepartment of Soil & Environmental Sciences Faculty of Agriculture Rawalakot University of Poonch, awalakot. email:
  2. 2. Why Water analysis is necessary? To asses water quality To provide pure water to public for drinking To analyse microbial organisms Preventive measure and effective disinfection procedure Sewagw and waste water analysed
  3. 3.  Physical assesment• Temperature• Ph• Turbidity• TSS Chemical assesment• Acidity• Alkalinity• COD• Chemical substances Biological assesment BOD Microbiological
  4. 4.  Colour in water is due to suspended particles in solution,even pure water is not colorless(pale-green) Colour of water may be caused by Fe,Mn,Cu,metals,Iron. humus,algae,weeds,protozoa etc. Colour can be compared visually or Photoelectrically. Colour is measured with an instrument known as Tintometer. Yellow color indicates the presence of O.M Yellow red color indicates. True color can be estimated by visual comparispon with platinum cobalt standard solution, unit is measured on cobalt scale.
  5. 5.  Turbidity in water mainly arises from colliodal material and fine suspended particles. Turbidity can be measured by absorptiometrically(visual methods) and nephelometrically(instrumental methods) Another methods used to measure turbidity is Turbidity Rod which has a platinum needle. Jackon,s turbidimeter which consists of metal stand over which a metal container is placed.
  6. 6.  Odour in water are sue to the presence of microscopic organisms or decaying vegetation including algae, fungi, bacteria, H2S, N, P, S compounds.Determination of Odour: For dermination of odour place 250ml of sample in a 500ml wthite mouth erlenmeyer flask & sniff the odour.
  7. 7.  Dissolve mineral matters in water produce tastes but not odour. If faint bitter taste may be due to the presence of Sulphate while soapy or inky taste may be due the excess of sodium bicarbonate. Way to remove objectionable taste & odour from water is to pass it through a filter bed containing activated charcoal, if finely divided form of carbon. The enormous surface area enables it to absorb large quantities of impurities.
  8. 8.  Surface water differs considerably in temperature b/w winter & summer. Temperature measurment are usefull in detecting an unsuspected suorce of pollution, in calculating alkalinity and in industrial water supplies for heat tranmision calculations.
  9. 9.  pH a measure of hydrogen ion activity is used to express the intensity of acidic or alkaline condition of a solution. It is an also important factor in water analysis. pH of a sample can be determine by electrometrically. it involves the measurment of EMF of a cell comprising an glass electrode response to hydrogen ion and refrence electrode. pH meters used for measurement. The desirable pH range for drinking water is 7-8.5
  10. 10.  EC is a measure of water’s capacity to convey electric current.its unit is micro Siemns/cm3 Conductivity of water varies directly with temperature and is proportional to its dissolved mineral matter content. It is an important to check the purity of distilled water. Distilled water with conductivity more the 2 should not be used for water analysis.
  11. 11.  500ml of a sample is taken in volumetric flask and allowed to filter through a dried and weighed Gooch crucible containing an asbestos mat.The suspended solids retained in the crucible or washed with distilled water to remove chloride. The crucible is finally dried, cooled in a desicator and weighed.the weighed of crucible is equalent to suspended impurities present.
  12. 12.  It is the power of water to neutralized hydroxyl ions and is expressed in terms of CaCO3. water attains acidity fron industrial effulents etc. Take 50ml of sample dechlorinated in a 250ml conical flask add 2 drops of methyl orange indicator and titrate with 0.02 N-NaOH solution till faint orange colour. Methyl orange point is a measure of mineral acidity. Amount of sodium hydroxide to reach pH 8.3 (phenolphthaline end point) is a measure of total acidity.
  13. 13.  Alkalinity of water is generally due to the presence of carbonate and hydroxide ion. It is measured by titrimetric method.
  14. 14.  Calsium in water mainly due to the presence of limestone,gypsum,dolomite. The determination of Ca is required potable water. EDTA titrimetric method and gravimetric method are used for determination of calcium. In EDTA titrimetric method Ca reacts with EDTA in the presence of a selective indicator at a high pH and Mg is allowed to precipitate as its hydroxide. Ca2+ + 2EDTA Ca(EDTA)2
  15. 15.  Magnesium salts occur in natural waters,sea waters(130ppm). It is measured by gravimetric method or photometric method. It may also be calculated as the difference between total hardness and Ca hardness as under: Mg(as CaCO3)mg/L =mg/L total hardness as CaCO3 –mg/L calcium hardness as CaCO3.
  16. 16. Ammonia N is present in water in the form of ammonia, nitrates & nitrites. The presence of the substances in water indicates the the presence of organic contamination. The amount of free ammonia is determine by boiling the sample of water. The quantitiy of ammonia in potable water should not be greater then 0.15 ppm. Ammonia is calorimrtrically measured using Nessler,s reagent.
  17. 17.  Nitrites are obtained by the oxidation of ammonia, nitrites should never be present in potable water. The presence of nitrites in water can be determine by adding sulphonilic and naphthamine. The permissible limit of Nitrate in drinking water is 10mg/L. The presence of nitrate in water bodies caused mathemoglobinemia. It can be measured by Brucine method.
  18. 18.  Cyanide Sulphate Sulphide Chloride Fluoride Fluoridation
  19. 19.  It is necessary to destroy these chemical substances by digestion with strong acids. Digestion destroys the O.M and brings metallic compounds in suspension to solution.
  20. 20.  Arsenic occur in water as a result of mineral dissolution,industrial waste or application of insectisides. The presence of As as 100mg in water cause poisoning,it can cause chronic effect. It can be measured by Gutzeit method.
  21. 21.  Cd enters water through industrial wastes,it is toxic and poisoning can cause human kidney. It can be measured in water sample by detected by dinitrophenyl carbazide.
  22. 22.  Beryllium (atomic absorption method) Copper (spectrophotometric method) Chromium (diphenylcarbazide method) Lead (atomic absorption method) Iron (spectrophotometric method) Selenium (spectrophotometric method) Mercury (dithizone method)
  23. 23. List of National Secondary Drinking Water RegulationsContaminant Secondary StandardAluminum 0.05 to 0.2 mg/LChloride 250 mg/LColor 15 (color units)Copper 1.0 mg/LCorrosivity noncorrosiveFluoride 2.0 mg/LFoaming Agents 0.5 mg/LIron 0.3 mg/LManganese 0.05 mg/LOdor 3 threshold odor numberpH 6.5-8.5Silver 0.10 mg/LSulfate 250 mg/LTotal Dissolved Solids 500 mg/LZinc 5 mg/L
  24. 24. Substances Max. Allowable limit1.Standards of chemical & physicalquality(a) Toxic metals Lead 10ug/L Arsenic 10ug/L Barium 0.10mg/L Cadmium 0.01mg/L Chromium 0.05mg/L Selenium 5ug/L Mercury 1ug/L(b) Substsnces affectin health Fluoride 1.5mg/L Nitrate 45mg/L
  25. 25. Substances Max. Allowable limit(c) Substances affecting potability of waterTotal solids 1500mg/LColour 50 unitsTurbidity 25 unitsTaste -Odour -Iron 1.0mg/LManganese 0.5mg/LCopper 1.5mg/LZinc 15mg/LCalcium 200mg/LMagnesium 150mg/LChlorine 0.1mg/LSulphate 400mg/LMangnesium + Sodium sulphate 1000mg/LPhenonic compounds 0.002mg/LCCE 0.5mg/L
  26. 26.  BOD is the measure of the dissolve oxygen required by the microbes in polluted water, it is measured in mg/L. During this process dissolve oxygen is consumed and micro-organism transform the ollutants into non- hazardous compounds. microbes CH2O+O2 CO2 +H2O+M.Org O.M aerobic oxidation
  27. 27.  The water sample is first saturated with oxygen and then incubated at constant temperature(20C) for 5- days. This allows the sufficient time for micro- organism in polluted water to affect oxidation of pollutants. After 5-days, the remaining amouny of dissolved oxygen is determined and BOD is obtained by substraction. The 5-day BOD(ppm) analysis is considerd as an accepted stndard test.
  28. 28.  Drinking water should have 5-day BOD of less than 1.5mg/L. BOD of raw sewge ranges from 200-400mg/L Major contributor to BOD are chemical industries, pulp and paper and food processig industry. BOD of very clean water is 1mg/L, clean water is 2mg/L and unfit for drinking water is 5mg/L.
  29. 29.  COD is a measure of oxygen required to breakdown the organic matter. In BOD breakdown of organic matter is affected by micro organisms but in COD the degradation is affected by some chemical oxidizing agent like Potasium dichromite .
  30. 30.  The water sample is treated with an oxidizing agent(K2Cr2O7) which oxidizes most of the polluting substances including those which are resistant to microbial oxidation. The unused potassium dichomite is determine by back titration with a suitable reducing agent like Mohr’s salt. The amount of oxygen used in oxidation can be calculated as:K2Cr2O7 + 4H2SO4 K2SO4+Cr2(SO4)3+4H2O+3(O)
  31. 31. COD in mg/L Status0-5 Very clean water, used for drinking5-20 Fairly clean20-100 Unfit for drinking
  32. 32. Microbiologicalparameters WHO standards EU standardsEscherichia coli Not mentioned 0 in 250 mlEnterococci Not mentioned 0 in 250 mlPseudomonasaeruginosa Not mentioned 0 in 250 mlClostridiumperfringens Not mentioned 0 in 100 mlColiform bacteria Not mentioned 0 in 100 mlColony count 22oC Not mentioned 100/mlColony count 37oC Not mentioned 20/ml