All of the following statements about purification of water are true except :
Correct Answer: Presence of Clostridial spores indicate recent contamination of water
Description: Spores of Cl. perfrignence (in the absence of coliform group) indicate remote fecal contamination of water.
Total coliform bacteria must not be detectable in any 100 ml of sample.
Sodium thiosulphate is used to dechlorinate tap water for aquariums or treat effluent from waste water treatments prior to release into rivers.
It is also used to lower chlorine levels in swimming pools and spas following superchlorination.
Presumptive coliform count is done by multiple tube method and membrane filtration technique.
After analysing presumptive coliform coutn, E coli count is confirmed by other tests litre Eijkmant test and indole production.
Category:
Social & Preventive Medicine
Get More
Subject Mock Tests
Practice with over 200,000 questions from various medical subjects and improve your knowledge.
Attempt a mock test nowMock Exam
Take an exam with 100 random questions selected from all subjects to test your knowledge.
Coming SoonGet More
Subject Mock Tests
Try practicing mock tests with over 200,000 questions from various medical subjects.
Attempt a mock test now