In what type of reactor does the treatment occur in a continuous flow manner?

The continuous stirred-tank reactor (CSTR) is designed to operate in a continuous flow manner, allowing for a steady input of influent and a simultaneous outflow of treated effluent. In a CSTR, the contents are mixed thoroughly, ensuring that the conditions within the reactor remain uniform. This type of reactor is particularly effective for processes that require a constant feed and allows for the continuous treatment of wastewater.

In contrast, a batch reactor processes a specific amount of wastewater at one time, with no inflow or outflow until the treatment phase is complete. This results in treatment occurring in discrete batches rather than continuously. Membrane bioreactors may operate in various modes, but they often incorporate aspects of both batch and continuous processes, depending on the setup. Fixed film reactors, such as trickling filters, also do not operate in a fully continuous manner as they rely on the biological growth on the media, alternating between active and dormant phases. Thus, the continuous stirred-tank reactor is the correct choice for continuous flow treatment.