Which equipment is used for calculation of amount of bleaching powder needed for purification of water?

UPPSC 2022

Community Health Nursing

Medium

Appeared in: UPPSC 2022

Explanation

Horrocks' apparatus is the specific tool designed to perform the Horrocks' test, which estimates the chlorine demand of a water sample.
Chlorine demand is the amount of chlorine consumed by organic matter and other impurities in the water before a disinfecting residual level can be achieved.
By determining the chlorine demand, one can accurately calculate the quantity of bleaching powder needed to effectively disinfect a large volume of water, such as a well.
This process ensures that enough chlorine is added to kill pathogens while preventing excessive residual chlorine, which can affect the taste and safety of the water.

Option A: The Pasteur Chamberland filter is a device for physical filtration, not chemical dosage calculation. It uses a porcelain candle to sieve bacteria from water.
Option B: The Berkefeld filter is another type of physical water filter that uses diatomaceous earth. Its function is to strain contaminants, not to measure chemical requirements.
Option D: The Katadyn filter is a modern portable filter that works by physical filtration through a ceramic element, often combined with silver ions for their antimicrobial (oligodynamic) effect. It does not calculate bleaching powder dosage.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Water purification methods, specifically the calculation of chemical disinfectant dosage as background academic context rather than a clinical decision trigger.
Ensuring access to safe drinking water is a fundamental public health intervention to prevent waterborne diseases like cholera, typhoid, and dysentery.
Community health nurses are often responsible for health education in rural and underserved areas, which includes teaching correct methods for well disinfection and safe water storage.
The ability to correctly calculate and apply disinfectants is a critical skill during public health emergencies, such as floods or disease outbreaks, to prevent widespread illness.

How to Approach the Question

First, identify the key action in the question: 'calculation of amount of bleaching powder'. This points towards a measurement or testing process, not a physical separation process.
Next, examine the options. Notice that three of the options include the word 'filter' (Pasteur Chamberland filter, Berkefeld filter, Katadyn filter).
Recall that filters work by physically straining or sieving contaminants from water.
This makes the filter options an incorrect match for a question about 'calculation'.
Identify 'Horrocks' apparatus' as the only option that is not a filter. An 'apparatus' is a set of equipment for a specific task, which aligns well with the concept of testing or calculating.
Conclude that Horrocks' apparatus is the logical choice for a tool used to calculate a chemical dosage for water treatment.

Concept Tested & Keywords

Concept Tested: Water purification methods, specifically the calculation of chemical disinfectant dosage.
Stem keywords: equipment, calculation, bleaching powder, purification of water
Lead-in keywords: Which
Negative lead-in flag: false

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E6 Parks TextBook of Preventive & Social Medicine part 2 — Subpart B (pp 233-449 of 464) p. 34-36