Chlorination of well

Chlorination of well is important in village area to prevent water borne and water washed disease .

1. COLLEGE OF NURSING AIIMS RAIPUR SUBJECT – COMMUNITY HEALTH NURSING PRESENTATION ON – CHLORINATION OF WELL SUBMITTED TO SUBMITTED BY Mr. Abdul munaf sir Teena goswami CON Aiims Raipur Roll no. 296 N ursing tutor Bsc [ hons ] nursing 4 th year

2. Objectives At the end of the lecture student will be able to – -Introduce about chlorination process of well -Define chlorination of well -Mechanism of action of chlorine on water. -Chlorine treatment standards , chlorine demand . -Step in well disinfection . -The double pot method . -Precaution should be taken when chlorinating well.

3. Chlorination of well Introduction – well are the main source of water supply in the rural areas. The need often arises to disinfect them, sometimes on a mass scale , during epidemics of cholera and gastroenteritis . The most effective and cheapest method of disinfecting wells by bleaching powder.

4. Definition Disinfection of wells by using chlorine gas , chlorinated lime {caocl2} or bleaching powder. Chlorination- is the process of adding the element chlorine to water as a method of water purification to make it fit for human consumption as drinking water .

5. Mechanism of action of chlorine on water Cl2 +H2o ---------- Hocl + ocl - Cl2 + water ------- 1. oxidizing organic acis 2. Reacts with organic nirtrogen 3. oxidize inorganic salts . 4. Free chlorine --- Hocl ---- ocl

6. CHLORINE TREATMENT STANDARDS Cx T T = Time water is in contact with the chlorine C = concentration of free chlorine {mg /l } Need Cx T = 6 – for ground water . 0.3 mg/l for 20 min. same as 0.6 mg/l for 10 min.

7. Chlorine demand It is the inherent properties of the water that consume chlorine . Or Chlorine demand is the difference between the amount of chlorine added to water or waste water and the amount of residual chlorine remaining after a given contact time , called chlorine demand of the water , and it may change with time temp. pH , and nature and amount of impurities in the water.

8. Total chlorine – The remaining chlorine concentration after the chlorine demand . Total chlorine –1 . combined chlorine – react with nitrate and unavailable for disinfection . 2. Free chlorine –chlorine available to inactivate disease causing micro- organism and thus a measure to determine the potability of water .

9. Steps in well disinfection- 1. Find the volume of water in a well. A} Measure the depth of water column--- h {m} B} Measure the diameter of the well – d {m} C} Substitute h and d in volume {L} = 3.14 d²xh x 1000/4 D} one cubic meter = 1,000 litres of water .

10. 2. Find the amount of bleaching powder required for disinfection. Annex- III – gives the amount of chemical needed to disinfect water for drinking Roughly – 2.5grams of good quality , bleaching powder is required to disinfect 1,000 liter of water . 0.7 mg bleaching powder applied / litre of water .

11. 3. Dissolve bleaching powder in water . The bleaching powder required for disinfecting the well is placed in a bucket { not more than 100mg in one bucket of water } and made into thin paste , more water is added till the bucket is nearly 3/4 full. The content are stirred well, and allowed to sediment for 5 to 20 min, when lime settles down . Supernatant solution which is chlorine solution, is transferred to another bucket and the chalk or lime is discarded .

12. 4. Delivery of chlorine solution into the well The bucket containing the chlorine solution is lowered some distance below the water surface , and the well water is agitated by moving the bucket violently both vertically and laterally. This should be done several times so that the chlorine solution mixes intimately with the water inside the well.

13. 5. Contact period A contact period of one hour is allowed before the water is drawn for use.

14. 6.Orthotolidine aresnite test It is a good practice to test for residual chlorine at the end of one hour contact . If the free residual chlorine level is less than 0.5mg/l , then the chlorination procedure should be repeated before any water is drawn .During epidemics of cholera wells , should be disinfected everyday.

15. The double pot method An improvement devised by the National Environmental Engineering Research Institute , of Nagpur India . 1.This method uses two cylindrical pots , one placed inside the other . 2. The inside height and diameter are 30 cm and 25 cm respectively , for the outer pot . 3.A hole 1 cm in diameter is made in each pot , in the inner pot the hole is in the upper portion, near the rim and in the outer pot it is 4 cm above the bottom. 4. A moisteneand mixture of 1 kg of bleaching powder and 2 kg of coarse sand { approx. 2mm in diameter } . The inner pot is filled with this mixture upto 3 cm below the level of the hole ,inner pot introduced into the outer pot. 5.Cover the mouth of pot with polyethylene foil. Thedouble pot method reduce the risk of overchlorination .

16. 7. The double pot is lowered into the well by means of a rope attached to well kerb. The pot should be immersed at least 1 m. below the water level to prevent damage by the buckets used for drawing water. 8. It has been found that this device works satisfsctory for 2-3 weeks in small household wells containing about 4,500 L of water and having a draw off rate of 360-450 L per /day.

17. Precautions should be taken when chlorinating well. Electrical safety – 1. turn off the pump circuit breaker before removing the well cap and while working on the well. 2. Wear rubber sole shoes or boots preferably waterproof . Chemical safety -1. always follow manufacture use and safety directions . 2. Avoid eye and skin contact , wear protective goggles or a face shield and rubber gloves when working with bleach . 3. Do not mix bleach with other chemical as they may form harmful gases.

18. Respiratory safety -1.underground well pits pose an extreme hazards , as they frequently contain a build up of toxic gases or simply lack of enough of oxygen to sustain life . 2.Leave disinfection of well in pit to professional licensed well contractor or pump installers. 3. Harmful gases may be generated during disinfection avoid inhalation of fumes and make certain enclosed space adequate ventilation before starting disinfection.

19. Conclusion Chlorination of well is a process in which chlorine gas is used for disinfection of water well and making water drinkable , by using different step and method .

20. ANY DOUBT?? .

21. recapitulation Define chlorine demand ? . what is total chlorine ? 3. Enlist the setp of chlorination of well. 3. What is double pot method ? 4. How can you check efficacy of chlorination ? 5. What kind of precaution measure used during chlorination of well ?