Final answer:
The correct order for water treatment processes is: Grit channel, primary sedimentation, aeration tank, and secondary sedimentation, which matches option c from the given choices.
Step-by-step explanation:
The correct sequence of water treatment processes from the options provided is grit channel, primary sedimentation, aeration tank, and secondary sedimentation. This sequence is based on the standard operations at a sewage treatment plant.
- Grit channel: Wastewater enters the grit chamber where larger particles, such as sand and dirt, are allowed to settle out. Aeration may be used during this process.
- Primary sedimentation: Following grit removal, sewage is stored in a basin allowing solids to settle to the bottom and lighter substances to rise.
- Aeration tank: After primary sedimentation, the wastewater is aerated to provide oxygen for microorganisms to decompose organic material.
- Secondary sedimentation: Following aeration, the water moves to a secondary clarifier where further settling of microorganisms and solids occurs.
Therefore, the correct order among the options given is c) Grit channel, primary sedimentation, aeration tank, and secondary sedimentation.