What type of compressor is described as a low pressure, low volume rotary air compressor?

The correct choice is the aeration blower. This type of compressor is specifically designed to operate at lower pressures and is used to provide a continuous flow of air, making it ideal for applications that require the introduction of oxygen into water, such as in wastewater treatment processes. The nature of the rotary mechanism allows for efficient air movement while maintaining lower volumes compared to other compressors. This is crucial in environments where maintaining a specific level of air saturation is necessary, demonstrating the blower's effectiveness in low-pressure situations.

Other options like the dewatering pump, micron filter, and vacuum pump serve different functions and are optimized for other pressure and volume requirements. Dewatering pumps are typically used to remove excess water from a specific area. Micron filters are involved in filtering impurities, and vacuum pumps are designed to create a vacuum environment rather than provide low-pressure air flow.