Which of the following pairs are correctly matched?

1. Lime soda process \(\leftrightarrow\) Softening

2. Nalgonda technique \(\leftrightarrow\) Fluoride removal.

3. Aeration \(\leftrightarrow\) Coagulation

4. Ozonation \(\leftrightarrow\) Disinfection.

Select the correct answer using the codes given below: Codes:

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Question

This question was previously asked in

OSSC JE Civil Mains (Re-Exam) Official Paper: (Held On: 3rd Sept 2023)

Answer 1

Correctly Matched Processes:

1. Lime soda process – Softening: This is correct. The lime-soda process is used to soften water by removing hardness caused by calcium and magnesium ions through chemical precipitation.
2. Nalgonda technique – Fluoride removal: This is correct. The Nalgonda technique is a method of fluoride removal from water, especially in rural areas, using a combination of chemicals like alum and lime.
3. Aeration – Coagulation: This is incorrect. Aeration is used to remove dissolved gases like carbon dioxide and oxidize dissolved metals, while coagulation involves adding chemicals to destabilize particles and form larger flocs. These are different processes.
4. Ozonation – Disinfection: This is correct. Ozonation is a powerful disinfection process that uses ozone gas to kill bacteria, viruses, and other pathogens in water.