Disinfection of Wells during an Emergency – The Double Pot Method
E.g. an outbreak of cholera
• During an emergency, it is desirable to ensure a constant dosage of chlorine to well water
• One method of doing this is the ‘Double pot method’
• The method is an improvement devised by the National Environmental Engineering Research Institute (NEERI), Nagpur, India
• There are two cylindrical pots
• One pot is placed inside the other
• Outer pot:
Inside height is 30 cm
Inside diameter is 25 cm
A hole (1 cm diameter) is made at 4 cm above the bottom
• Inside pot:
Fits into the outer pot
Has a hole (1 cm diameter) near the upper end
• A mixture of 1 Kg bleaching powder and 2 Kg sand is prepared and moistened with some water
• The inner pot is filled with this mixture up to 3 cm below the hole
• The inner pot is placed into the outer one
• The mouth of the latter is closed with polyethylene foil
• The double pot is lowered into the well by means of a rope attached to the 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
• This device works satisfactorily for 2 – 3 weeks in small household wells containing 4500 L of water and a draw off rate of 360 to 450 L per day
OT and OTA test: http://www.ihatepsm.com/blog/orthotolidine-ot-test-and-orthotolidine-%E2...
Membrane processes in water purification: http://www.ihatepsm.com/blog/membrane-processes-treatment-drinking-water
Super Chlorination and Break Point Chlorination: http://www.ihatepsm.com/blog/super-chlorination-and-break-point-chlorina...
Slow sand filter: http://www.ihatepsm.com/blog/slow-sand-filter-biological-filter
Rapid sand filter: http://www.ihatepsm.com/blog/rapid-sand-filter-mechanical-filter
Purification of water at a large scale: http://www.ihatepsm.com/blog/water-purification-large-scale-water-supply
Criteria for a Chemical to be Suitable as Water Disinfectant in Water Supplies: http://www.ihatepsm.com/blog/criteria-chemical-be-suitable-water-disinfe...
Water Supplies Disinfection with Chlorination: http://www.ihatepsm.com/blog/water-supplies-disinfection-chlorination
Principles of Chlorination: http://www.ihatepsm.com/blog/principles-chlorination
Methods of Chlorination in Water Supplies: http://www.ihatepsm.com/blog/methods-chlorination-water-supplies
Horrock's Apparatus: http://www.ihatepsm.com/blog/horrock%E2%80%99s-apparatus
Disinfection of well during emergency: http://www.ihatepsm.com/blog/disinfection-wells-during-emergency-%E2%80%...
Double Pot method: http://www.ihatepsm.com/blog/disinfection-wells-during-emergency-%E2%80%...
Disinfection of Wells: http://www.ihatepsm.com/blog/disinfection-wells
OT and OTA test: http://www.ihatepsm.com/blog/ot-and-ota-test
Domestic or Household Purification of Water: http://www.ihatepsm.com/blog/domestic-or-household-purification-water