Water Treatment MCQ with answer and solution

Concept

Minor methods of water disinfection

Formula

NONE

Step-by-step solution

1. Minor methods of water disinfection include treatment with excess lime, iodine, bromine, potassium permanganate, and UV rays. 2. Aluminum compounds like alum are used as coagulants during the sedimentation process. 3. Therefore, treatment with aluminum powder is not a minor method of disinfection. Answer: D

Explanation

Aluminum powder is used as a gas-forming agent or reactant in specialized concrete mixtures rather than as a water disinfection agent. Methods such as treatment with excess lime, iodine and bromine, or potassium permanganate are recognized minor methods used to eliminate pathogenic organisms in water. Consequently, aluminum powder treatment is not a valid method for water disinfection.

Why the other options are wrong

A) Treatment with excess lime is a minor disinfection method that raises pH to kill pathogens. B) Treatment with iodine and bromine is a recognized minor method for small-scale disinfection. C) Treatment with potassium permanganate is a minor method used for disinfection and oxidation.

Shortcut

Aluminum powder is a coagulant or gas-forming agent, not a disinfectant.

Common mistake

Assuming aluminum powder is a water disinfectant rather than a chemical agent or coagulant.