Which of the following is NOT a stage in sewage treatment?

The correct choice indicates an option that does not align with the conventional stages of sewage treatment. Sewage treatment typically involves several key processes to ensure that wastewater is treated effectively before it is released back into the environment or used for other purposes.

Screening and grit removal is an essential initial stage where large solids and grit are filtered out of the sewage. This helps protect the subsequent processes in the treatment plant.

Sedimentation is another critical stage where the liquid sewage is allowed to settle in tanks. This results in the separation of solid waste, forming sewage sludge that can be processed further.

Aerobic biological treatment is a method used to break down organic materials in the effluent using microorganisms in the presence of oxygen. This process significantly reduces the pollution potential of the wastewater.

In contrast, incineration of solid waste is not a standard stage in sewage treatment. While incineration is a method used for managing solid waste, it is not directly part of the wastewater treatment process itself. Instead, it pertains to the disposal of already treated solids, which may occur separately from the sewage treatment stages. Therefore, this option is correctly identified as the one not included in the main sewage treatment stages.