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The potable water is prepared from turbid surface water by adopting the following treatment sequence.

1. Turbid surface water → Coagulation → Flocculation → Sedimentation → Filtration → Disinfection → Storage & Supply
2. Turbid surface water → Disinfection → Flocculation → Sedimentation → Filtration → Coagulation → Storage & Supply
3. Turbid surface water → Filtration → Sedimentation → Disinfection → Flocculation → Coagulation → Storage & Supply
4. Turbid surface water → Sedimentation → Flocculation → Coagulation → Disinfection → Filtration → Storage & Supply

Correct answer: Turbid surface water → Coagulation → Flocculation → Sedimentation → Filtration → Disinfection → Storage & Supply

Solution

The correct sequence starts with coagulation to remove suspended particles, followed by flocculation to form larger aggregates, then sedimentation to settle these aggregates, filtration to remove remaining impurities, and finally disinfection to kill pathogens before storage and supply, ensuring safe and clean potable water.

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