Presentation Transcript

1. CLASS Civil Engg 4th Sem Subject WATER supply & SEWAGE EENG (NATURAL METHOD OF SEWAGE DISPOSAL) RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
2. DISPOSAL OF SEWAGE RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society

3. GENERAL

   The method used for disposal of sewage are called disposal methods. The sewage can be disposed of after suitable treatment or without treatment. Sewage is finally disposed off either on land or in large bodies of water like sea, river or lake. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
4. SEWAGE Waste water often contain high level of organic matter from industrial , agricultural & human waste. Sewage is a collection of all domestic, industrial & storm-water run off. The treatment of human waste impacted waters with many pathogens that may be present is very important. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
5. WASTE WATER Defined combination of liquid or water carried wastes removed from residences, institutions & commercial & industrial establishment. If it is left untreated , may cause spread diseases . RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society

6. OBJECTS OF SEWAGE DISPOSAL.

   To eliminate or reduce danger to the public health by possible contamination of water supplies. To render the sewage inoffensive without causing odour or nuisance. To prevent the life of fish or other aquatic life by allowing raw sewage into bodies of water as such. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
7. OBJECTS OF SEWAGE DISPOSAL The destruction of fish & other Aquatic life can be prevented by the swage disposal methods. With proper sewage disposal the environment or the areas does not become polluted. Sanitary condition are maintained in the area. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
8. DISPOSAL METHOD There are two principal methods of sewage disposal by utilizing natural agencies i.e., Dilution i.e., disposal of sewage of water. Land disposal or irrigation. Both methods are very simple. But these may be regulated carefully so that the quantity of sewage put in water or applied to land is such that they are capable of receiving the organic load present in the effluent. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society

9. DILUTION

   Dilution is the disposal of sewage by discharging it into large bodies of water like sea, streams, rivers etc. This method is possible only when the natural water is available in large quantity near the town. Proper care should be taken while discharging sewage in water so that sewage may not pollute natural water and make it unfit for any other purposes like bathing, drinking, irrigation etc. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society

10. CONDITIONS FAVOURING DILUTION

    Where sewage is fresh. Where favorable currents exits in a stream. Where sewage is almost free from floating settleable solids. Where through mixing is possible. Where diluting water has high quantities of dissolved oxygen. When the city is situated near river or sea. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
11. SOURCES OF SEWAGE DISPOSAL CREEKS LAKES STREAM & RIVERS GROUND WATER SEA OR OCEAN RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
12. SOURCES OF SEWAGE DISPOSAL CREEKS :-These are in the form of an inlet on sea coast . These may or may not have DWF (Dry water flow ).Sewage in creeks should be disposed off very carefully. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
13. SOURCES OF SEWAGE DISPOSAL LAKES:-These are enclosed depressions & are sometimes used for the dilution of sewage. The factors which affect the process of dilution of sewage by this method include size , shape , nature of area ,volume of fresh water flowing in it etc . RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
14. SOURCES OF SEWAGE DISPOSAL STREAMS & RIVERS :-The discharge in rivers & streams is less in summer . Due to the reason , it is difficult to carry our dilution of sewage in summer because the temp. in summer is high which results in low solubility of oxygen. Therefore disposal , sewage should be properly treated . RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
15. SOURCES OF SEWAGE DISPOSAL GROUND WATER :-In this case ,sewage is applied on land .It filters through different soil layers & meets ground water. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
16. SOURCES OF SEWAGE DISPOSAL SEA OR OCEAN:-sewage can be disposed off in the sea water . The temp. of sea water is lower than the sewage temp. But the sp, gravity is higher. Due to above reason , the sewage discharged into the sea water remains at the surface & forms a thin film due to its lower sp. Gravity .The prevailing dissolved matters & the various chemical actions in the sea water reduce its capacity in absorb more quantity of water. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
17. SOURCES OF SEWAGE DISPOSAL Some precautions to be taken while diluting sewage into sea water. The sewage should be discharged at that point where the depth of water is more. The sewage discharging pipe should be taken sufficiently deep in sea say 1.5 km so that the sewage may not come back again to the shore by heavy tides & create nuisance. The outfall sewers should be provided with reflux vavle to prevent back flow of sewage . RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
18. NUISANCE DUE TO DISPOSAL PHYSICAL NUISANCE CHEMICAL NUISANCE BACTERIAL NUISANCE PHYSICAL NUISANCE;-The deposits of suspended solids depends upon the bed & banks of a stream have certain nuisance characteristics .The physical nuisance are unsightliness due to floating matter which causes turbidity & colour .The volume of water & velocity of following water are the factors which affect the physical nuisance. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
19. NUISANCE DUE TO DISPOSAL CHEMICAL NUISANCE:-The biological oxidation results in changes of chemical nature. Dissolved oxygen is water is consumed by the bacterias & in extreme case , the water without dissolve oxygen may destroy green plant & fish life . BACTERIAL NUISANCE:-It deals with the possible presence of pathogenic bacterias in the sewage & thus in polluted stream , such bacterias if present may cause various diseases & even death of fishes & the aquatic life . RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society

20. SELF-PURIFICAION OF STREAMS

    The natural process in which the oxygen of water of streams is consumed by sewage and at the same time it is filled again by the atmosphere is called self-purification of streams. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society

21. FACTORS HELPING SELF-PURIFICATION OF STREAMS:-

    Dilution Sedimentation Sun-light Oxidation Reduction Temperature Bacteria. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
22. FACTORS AFFECTING SELF PURIFICATION OF STREAM Dilution Sedimentation Oxidation Reduction Sunlight Velocity of currents Temperature Biological forces RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
23. FACTORS AFFECTING SELF PURIFICATION OF STREAM Dilution;-when sewage is discharged into the stream water , the offensiveness of the organic matter is diminished by its dispersion through the diluting water .The sewage always remains in aerobic condition & anaerobic conditions never comes because dissolved oxygen always remains present in the water. Organic matter present in sewage is diluted due to dilution by water and therefore nuisance value is decreased. Surface tributaries and underground streams accelerate the process. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
24. FACTORS AFFECTING SELF PURIFICATION OF STREAM SEDIMENTATION:-The heavier solids with slow current settle in the stream bed & start anaerobic decomposition .The products of decomposition are mixed again with water by the currents . An aerobic condition will not develop if dilution is sufficient & scouring tendency of streams during floods will wash the deposits.Settleable solids drop down to the bottom of the stream in the form of sludge deposits. Hence it is purified to some extent. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
25. FACTORS AFFECTING SELF PURIFICATION OF STREAM OXYDATION ;-The oxidation of the organic matter starts as soon as sewage is discharged into the diluting water due to CHEMICAL REACTION GROWTH & ACTIVITY OF OXIDISING ORGANISMS. When the organic matter meets the water; it starts getting oxidized due to development of oxidizing organisms in water. The process continues till the organic matter has been completely oxidized. The oxygen demand is fully satisfied, the stream becomes pure. Water always contains some dissolved oxygen and it is responsible for oxidation of organic matter. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
26. FACTORS AFFECTING SELF PURIFICATION OF STREAM Reduction:-when organic matter hydrolyses either chemically or biologically by anaerobic organisms to form gases from the liquids, the process is known as reduction. It occurs due to hydrolysis of organic matter other biologically or chemically. It also helps for stabilization by oxidation. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
27. FACTORS AFFECTING SELF PURIFICATION OF STREAM SUNLIGHT;-It has sterilizing effect on certain bacterias, bleaching powder & photosynthesis by which chlorophyll bearing organisms take energy from sun & convert it into food for other forms of life . Co2 is absorbed & o2 is evolved in the process. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
28. FACTORS AFFECTING SELF PURIFICATION OF STREAM VELOCITY OF CURRENT:-The natural self purification of the stream directly depends upon the currents of water .When there is no current ,the sewage matter deposits near the outfall causing formation of sludge tanks & foul odour . RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
29. FACTORS AFFECTING SELF PURIFICATION OF STREAM TEMPERATURE:- The activities of the organisms depends on the temp. Lower the temp. slower the activity of organisms hence slower the rate of decomposition of organic matter of sewage & vice versa. Therefore , stream will get self purified in less time in summer than in winter. The various actions involved are physical, chemical and biological. These are effect by turbulence of water which causes aeration. Hence it is always desired to discharge sewage into a fast moving body of water so that whenever nuisance takes place is located far below the outfall. Temperature also plays an important role in purification. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
30. FACTORS AFFECTING SELF PURIFICATION OF STREAM BIOLOGICAL FORCES:-Biological forces include bacteria which attack organic matter . The organic matter is converted into chemical substances. Various types of bacteria, algae, protozoa etc; are responsible for the self purification of the streams as they convert the organic matter into simple mineral & other matter .Algae absorbs co2 & supplies o2 .Protozoa like algae as well keep some bacteria growing. Organic solid matter is converted into gases and liquids by bacteria, therefore it helps the streams to purify itself. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
31. SUITABILITY OF L.T.M OF SEWAGE DISPOSAL The method is suitable when :- The overall rainfall is very low. The natural water courses are not available. The quantity of sewage is more which pollutes the natural water courses. The rivers have very small discharge during summer. The water table is very deep and is not likely to be polluted by adopting the land treatment method of disposal. The vegetables have good market value as by adopting land treatment, the income also increases. The soil is porous as it will allow good areation. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
32. ADVANTAGES AND DISADVANTAGES OF LAND DISPOSAL Advantages:- Adds manure to land Pollution of natural water courses is minimized. Increase fertility of land. Gives high calorific value to crops grown in sewage farms. Does not require any installation of equipment involving high initial cost. Crops could be grown and hence a return value is always possible to obtain. Method specially suitable where large quantity of river water is not available at all times of the year. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
33. (B) DISADVANTAGES:- Difficult to get land during rainy and harvest seasons. Additional land is required for reserve. Sanitary reasons may not permit growing of crops on sewage farms. More land area is required is sewage volume is greater since land capacity is limited. If all precautions are not taken, sewage farming results in sewage sickness to land and health to life. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
34. METHOD OF LAND TREATMENT Sewage mainly contains water which can be used for irrigation purposes . The fertilising value of sewage is more because it contains n, potash & phosphate .The sewage can be applied in the following forms BROAD IRRIGATOIN SEWAGE FARMING. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
35. BROAD IRRIGATION In this method, sewage is allowed to flow over cultivated lands, from which a part of the sewage evaporates, some percolates and the rest escape into surface drainage channels. Sewage waters the land and adds to its fertilizing value, due to the presence of nitrogen, phosphorus, potash etc. These fertilizing elements of sewage are consumed by the roofs of crops. Crops like cotton, potatoes, sugarcane, grass etc, can be profitably growth. This is also called sewage farming. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
36. BROAD IRRIGATION RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
37. SEWAGE FARMING The process in which sewage is used for growing crops is known as sewage farming .The fertilising elements of sewage i. e nitrates, sulphates, & phosphates are used by the roots of crops. The nutrients of sewage make the fields fertile .It is a profitable business & a good income can be generated by sewage farming. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
38. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
39. APPLICATION OF SEWAGE METHODS FLOODING METHOD SURFACE IRRIGATION METHOD ZIG ZAG METHOD LAGOONING METHOD BASIN METHOD SUB-SOIL IRRIGATION METHOD RIDGE AND FERROW IRRIGATION METHOD. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
40. APPLICATION OF SEWAGE FLOODING:- The area to be irrigated is divided into various parts surrounded by dykes. The sewage is filled like small ponds in between the dykes. The depth of dose varies from 3.0 cms. To 5.0 cms. Depending on the irrigation requirements. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
41. APPLICATION OF SEWAGE SURFACE IRRIGATION:- This method is most suited in sloping area. Here, parallel drains are constructed in the fields. All these drains are connected to a distributaries drain with the help of regulating device so that sewage may flow in the require drain. Here when sewage flows over the fields, its large quantity is absorbed by the field and only excess quantity reaches another drain. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
42. SURFACE IRRIGATION METHOD RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
43. In the zigzag run method: In this method the ridges are arranged in a zag-zag method with corresponding furrows by their side. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
44. LAGOONING LAGOONING: These are used cheaply for sewage disposal. In this method the sewage is allowed to in a natural depression available or artificial constructed tanks. Detention period is about a month. During this period the sludge is stabilized and dried. The purified effluent passes way from an outlet placed at the other end. Lagoons should be shallow and must be constructed away from the town. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
45. Comparison of dilution & land treatment method of disposal of sewage RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
46. BASIN METHOD: In this method big trees are planted in an isolated manner, basins are formed around each tree. These basins are filled with sewage. This method is suitable for fruit gardens. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
47. SUB SURFACE IRRIGATION SUB SURFACE IRRIGATION: Here sewage is applied at the roofs of plants, through the open jointed agricultural drain-pipes. These pipes are laid about 1.0 m below the ground level. The sewage rises up due to capillary action. Here soil takes less load but this is an economical method. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
48. SUB SURFACE IRRIGATION RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
49. RIDGE AND FERROW IRRIGATION METHOD In this method , sewage is supplied in furrows between crop rows. Sewage spreads laterally irrigating the area between two furrows. The width of furrow varies from 120-150 cm and the depth from 25-50 cm. The width of the ridge varies from 125-250 cm and length from 10-30 m. The percolated effluent is collected in underground drains flows towards natural drainage for disposal. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
50. RIDGE AND FURROW METHOD RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society

51. FAVOURABLE CONDITIONS FOR SUB-SURFACE IRRIGATION

    Subsoil water level is low. Land is cheap. Rainfall is less and irrigation water demand is heavy. Large areas are available. Where dilution water is not easily available. Sub-surface strata is porous, favoring infiltration. Climate is dry favoring drying up conditions. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
52. SEWAGE PUMPING The process of lifting the sewage from the low lying areas to high level areas in order to join the sewage into gravity sewers is known as sewage pumping .the pumping of the sewage becomes essential under the following circumstances. If the area is at a lower level than the rest of the town , then this part is separately designed .The sewage is collected separately in a sump well at the lowest point from where it is pumped into the gravity Sewer. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
53. SEWAGE PUMPING If the sewage is required to be pumped from the basement. If the sewage is required to be carried over streams, natural drainages etc. If the sewage is to be pumped in order to allow it to flow by gravity again. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
54. SEWAGE PUMPING WORKING:-The sewage is received in a sump well which is covered at the top similar to manhole. The bottom of the sump well is towards the pump in order to form a small suction pit . The float rises when the flow in the pump well increases .The pump is started by switching over the power .When the flow decrease , the float comes down & the power is cut off. They are referred as automatic starters & are installed in the pump room. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
55. SEWAGE PUMPING installation RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
56. AIR JET The device which lifts the sewage from low lying areas to join the sewage into gravity sewers by compressing air is known as air ejector . It is required under the following circumstances When the sewage is required to be lifted from the basement to the level of sewer. When the sewage of the low level areas is required to be lifted to a higher level in order to allow it to flow under gravity. Where the slope of the ground is flat. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
57. AIR JET working The air ejector is placed below the level of the sewer draining into it so that it could be filled with sewage by gravity only .when the sewage enter the vessel , the air inside the vessel escape out through exhaust pipe & then exerts pressure at upper cup which lofts the spindle for allowing the compressed air to enter the vessel & the sewage through it. As soon as the level of sewage falls below , the upper cup gain weight & makes the spindle in downward direction closing the entry of compressed air .It works automatically .These ejectors are installed in small chamber below the gravity sewer sufficiently. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
58. AIR JET working/ installation RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
59. SEWAGE SICKNESS The phenomenon by which the soil looses its capacity of receiving the sewage load is known as sewage sickness. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
60. SEWAGE SICKNESS PREVENTION OF SEWAGE SICKNESS:- Primary treatment like screening & sedimentation should be given to sewage before its application to land so that suspended solids are removed & the pores of soil will not be clogged. The sewage should be applied intermittently on land i.e by giving rest to the land for sometime .The land should be ploughed during non supply period of sewage so that soil gets aerated. RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
61. PREVENTION OF SEWAGE SICKNESS Keeping some portion of land reserved in order to use the same in resting period .Enough area will be required for this purpose. By planting different crops on the same land by rotation system of crops .The soil will be aerated & will utilise the fertilizing elements of sewage . By providing sufficient under drainage system to collect the excessive sewage quantity. By frequent ploughing & rotation of soil. By not applying the sewage in excess quantity . RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society
62. THANKS RAJ KUMAR, SENIOR LECT. CIVIL 9463370562 Punjab Edusat Society