Water treatment and analysis ....ppt....

For first year polytechnic

1. SANJIVANI K. B. P. POLYTECHNIC, KOPARGAON With NBA ACCREDIATED programs , Approved by AICTE, New Delhi, Recognized by Govt. of Maharashtra , Affiliated to Maharashtra State Board of Technical Education, Mumbai, ISO 9001:2015 Certified Institute Department:- Computer Technology Class:- First Year Name of Subject:- Applied Chemistry MSBTE Subject Code:- 312308

2. Mrs. Bhattad K.S. SKBP polytechnic, K opargaon Unit 2 Water Treatment & Analysis Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

3. Syllabus of unit 5.1 Hard and soft water, causes of hardness, types of hardness 5.2 Hard water in boilers and prevention: Boiler corrosion, caustic embrittlement, priming and foaming, scales and sludges,and methods of prevention of boiler corrosion. 5.3 Methods of water softening: lime soda process (hot lime soda and cold lime soda process), zeolite process, ion exchange process. 5.4 Potable water treatment: Sedimentation, coagulation, filtration and sterilization . 5.5 Wastewater treatment: Sewage treatment, BOD and COD of sewage water. 5.6 pH and pOH: Concept of pH, pOH, pH Scale, Numerical. Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

4. Introduction- Sources of water and impurities associated with water Impurities associated with water Types of water- 1 . Soft water-Forms g ood lather with soap. 2.Hard water- Forms less or no lather but scum with soap. Hardness Causes of hardness of water Types of hardness- Measurement of degree of hardness- Soap solution method & EDTA method Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

5. Causes of hardness of water Rain water absorb CO 2 from air, when such water flows through soil the salt from soil tend to dissolve in such water. H 2 O + CO 2 → H 2 CO 3 H 2 CO 3 + CaCO 3 → Ca (HCO 3 ) 2 Soaps are sodium or potassium salts of long chain fatty acids. When soap is added to hard water, the Ca2+ and Mg2+ ions present in hard water react with soap. The sodium salts present in soaps are converted to their corresponding calcium and magnesium salts which are precipitated as scum. The insoluble scum sticks on the clothes and so the cleaning capacity of soap is reduced . Ca 2+ +  2RCOO - Na + → (RCOO) 2 Ca + 2Na +   Mg 2+ + 2RCOO - Na + → (RCOO) 2 Mg + 2Na + The salt of Ca and Mg is called as SCUM. Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

6. How water becomes hard & difference of exposure Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

7. How water becomes hard & difference of exposure Presentations are communication tools that can be used as demonstrations, lectures, speeches, reports, and more. It serves a variety of purposes, making presentations powerful tools for convincing and teaching.

8. Temporary hardness & permanent hardness Ca (HCO 3 ) 2 Mg(HCO 3 ) 2 CaSO 4 MgSO 4 CaCl 2 MgCl 2 Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

9. Effect of hard water in boilers and prevention 1. Boiler corrosion- Boiler is made up of steel/iron plates. It gets disintegrated by attack of salts present in hard water. Boiler corrosion occurs due to 1. Dissolved salts - Salts like CaSO4, MgCl2, CaCl2 etc Makes water acidic and lead corrosion. MgCl2 + 2H2O → Mg (OH)2↓ + 2HCl 2. Dissolved gases Dissolved oxygen in water is mainly responsible for the corrosion of boiler. The dissolved oxygen and carbon dioxide in water attacks the boiler material at higher temperature. 4Fe + 6H2O + 3O2 −−−> 4Fe(OH)3 ↓ H2O + CO2 -- → H2CO3 Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

10. How to minimize boiler corrosion Corrosion due to dissolved salt which makes water acidic can be minimized by adding ALKALI to netralize water. Corrosion due to dissolved oxygen can be minimized by adding reducing agent like hydrazine, sodium sulphite or sulphide Corrosion due to carbon dioxide can be minimized by deaeration or adding ammonium hydroxide. Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

11. 2. Caustic embrittlement- Caustic embrittlement  in a  boiler  is a process in which the  boiler  material becomes brittle due to the accumulation of  caustic  substances. ... It is a form of corrosion caused by a high concentration of sodium hydroxide ( NaOH ) in the  boiler  feed water. Caustic embrittlement means inter crystalline cracking of boiler metal. Boiler water usually contains a small proportion of Na2CO3 In high pressure boilers this Na2CO3 undergoes decomposition to give NaOH. Fe + 2NaOH → Na2FeO2 + H2 Caustic embrittlement can be minimized using sodium phosphate instead of sodium carbonate. Use of tannin or lignin to fills hair line cracks in boiler. Adjusting pH of boiler feed water in between 8 to 9. Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

12. 3. Priming & foaming Priming - Entry of small water droplet in steam is priming. Foaming is presence of persistent foam or bubbles in boiler. Priming can be minimized by proper design of boiler & Maintaining low water level. For foaming antifoaming agent like castor oil or silicic acid are used. Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

13. 4. Scale and sludge formation Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S. Sludge - If the precipitate is loose and slimy it is called Sludge. Sludges are formed by substances like MgCl2,MgCO3, MgSO4 and CaCl2. They have greater solubilities in hot water than cold water. Scale - On the other hand, if the precipitate forms hard adherent coating on the inner walls of the boiler, it is called scale. Scales are formed by substances like Ca(HCO3)2, CaSO4 and Mg(OH)2.

14. Disadvantages of scale formation : (1) Wastage of fuel :  Scales have a low thermal conductivity, so the rate of heat transfer from boiler to inside water is greatly decreased. In order to provide a steady supply of heat to water, excessive or over heating is carried out  and this causes increase in fuel consumption . (2) Lowering of boiler safety :  Due to scale formation, over-heating of boiler is to be done in order to maintain a constant supply of steam. The over-heating of the boiler tube makes the boiler material softer and weaker and this causes distortion of boiler tube and makes the boiler unsafe to bear the pressure of the steam, especially in high-pressure boilers. (3) Decrease in efficiency :  Scales may sometimes deposit in the valves and condensers of the boiler and choke them partially. This results in decrease in efficiency of  boiler. (4) Danger of explosion :   When thick scales crack, due to uneven expansion, the water comes suddenly in contact with over-heated iron plates. This causes  formation of a large amount of steam suddenly. So sudden high-pressure is developed, which may even cause explosion of the boiler. Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

15. Removal Of Scale ( i ) With the help of scraper or piece of wood or wire brush, if they are loosely adhering . ( ii) By giving thermal shocks (i.e., heating the boiler and then suddenly cooling with cold water), if they are brittle. ( iii) By dissolving them by adding them chemicals, if they are adherent and hard. Thus, calcium carbonate scales can be dissolved by using 5-10% HCl . Calcium sulphate scales can be dissolved by adding EDTA (ethylene diamine tetra acetic acid), with which they form soluble complexes. ( iv) By frequent blow-down operation, if the scales are loosely adhering. Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

16. Water softening The process of removing soluble Ca & Mg salts from hard water is called softening of water. 1. Lime –soda process 2. Zeolite or permutit process. 3. Ion exchange process Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

17. Lime soda process- Hot & Cold- Batch & Continuous This method removes temporary & permanent hardness. Bicarbonates and carbonates are removed by lime whereas sulphates and chlorides are removed by soda. Alum is also used to remove impurity. 3Ca(HCO 3 ) 2  + Al 2 (SO 4 ) 3   → 2Al(OH) 3  + 3CaSO 4  + 6CO 2 Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

18. If water contains sulphates & chloride of Mg then both soda & lime are required. If sulphates & chlorides of Ca then only soda is required. Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

19. Zeolite or permutit process- Permutit are complex silicates of several metallic & non metallic elements. Na 2 Al 2 Si 2 O 6 .6H 2 O Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

20. Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

21. Ion exchange or demineralization or deionization process- Uses resins- cation exchanger RH 2 & anion exchanger R’( OH) 2 Ion exchange is accomplished by passing the water through columns of a natural or synthetic resin that exchange both cation and anion. . Ion exchange resins are of two types  1. Cation exchange resins  2. Anion exchange resins Cation exchange resins (RH+): These are capable of exchanging H+ ions with the cations. It is mainly styrene divinyl benzene copolymer. They have acidic functional groups like -SO3H, -COOH etc Anion exchange resin (ROH-)  These are capable of exchanging OH ions with the anions. It is nothing but a copolymer of styrene divinyl benzene Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

22. Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

23. Ion exchange filter Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

24. Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S. Water coming out from the exchanger is free from cations and anions and is known as deionized or deminerealized water.

25. Potable water treatment Sedimentation Coagulation Filtration- Gravity sand filter & pressure filter Sterilization- Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

26. Coagulation Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

27. Gravity Sand Filter Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

28. Sterilization - Making water disnfected or free from bacteria 1. Boiling 2. Chlorination- by using 1. chlorine, 2. bleaching powder , 3 . chloramine, 3. Ozonization 4. Aeration 5. Ultraviolet rays---- Swimming pool, Water park 6. Removal of algae Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

29. Mostly sterlisation is done by using chlorine or ozone. A. Chlorination- by using 1. chlorine , 2. bleaching powder[CaOCl 2 ] 3 . chloramine [ ClNH 2 ] Cl2 +H2O →HCl + HOCl(Hypo chlorous acid which kills germs) Use chlorine may produce unplesant taste, odour and irritation on mucous membrane. CaOCl2+H2O → Ca (OH)2 + Cl2↑ Use of bleaching powder imparts hardness to water. ClNH2 + H2O → HOCl + NH3 Chloramine imparts good taste to water. B. Ozonization- O 3 → O 2 + [O] Ozone sterlizes, bleaches and decolourises water. Imparts good taste even in excess also not harmfull. Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

30. Sterilization - Making water disnfected or free from bacteria Boiling water for certain miniute kill all bacterial. This is most trustfull method but can be performed at small scale inside home. 1. Boiling 01 Chlorine can be used from free chlorine, bleaching powder or chlramine. See in ppt. .... Using chlorine - 02 O 3 → O 2 + [O] Ozone sterlizes, bleaches and decolourises water. Imparts good taste even in excess also not harmfull. 3. Ozonization 03 Passing air through water also disinfect water and impart good taste. Passing air means excess oxygen in water. 4. Aeration 04 5. Ultraviolet rays---- This technic is adapted for Swimming pool, Water park. Water is only allow to come in contact with UV radiation. UV radiation kills bacteria directly. UV radiation 05 To remove algae from water, the most common method is to use a chemical like chlorine, which effectively kills algae by breaking down its cell walls; other options include using a UV light to sterilize the water, physical filtration to remove visible algae clumps, or addressing the root cause of algae growth by managing sunlight exposure and water quality in the container holding the water. 6. Removal of algae 06

31. Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S. Ozonization

32. Waste water treatment Wastewater treatment is the process of converting wastewater into water that can be discharged back into the environment. Sewage means liquid flowing through ditch. Characteristics of sewage Sewage treatment BOD & COD of sewage BOD- Biological oxygen demand COD - Chemical Oxygen demand Recycling of waste water Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

33. Sewage Treatment plant ( Dear students Three plant are suggested draw any one) Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

34. Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

35. pH & pOH pH measures the concentration of hydrogen ions in a solution, while pOH measures the concentration of hydroxide ions. The pH scale ranges from 0 to 14, with values below 7 indicating an acidic solution, values of 7 being neutral, and values above 7 being basic. pH = −log [H+] pH is defined as the negative logarithm of H+ ion concentration. Hence the meaning of the name pH is justified as the power of hydrogen. pOH = −log [OH-] pOH is defined as the negative logarithm of OH- ion concentration. pH + pOH = 14. Numericals 1. Calculate pH of 0.0025M NaOH Solution. 1. Calcuate hydroxyl ion concntration of solution whose pH is 3.5. Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.

36. Learning Objective After studying this unit you must understand following concept- 1. Difference between Soft water & Hard water. 2. Types of hardness 3. Effect of hard water in boiler. 4. Various water softening technic. 5. Potable water treatment. 6. BOD & COD of Sewage 7. pH & pOH Thank You Sanjivani K.B.P. Polytechnic, Kopargaon Department of Computer Technology Mrs. Bhattad K.S.