Which of the following is a type of positive displacement pump used to feed liquid chemicals?

The peristaltic pump is indeed a type of positive displacement pump designed specifically for feeding liquid chemicals. This type of pump operates by using a rotating mechanism to compress and expand a flexible tube or hose, creating a vacuum that draws the liquid in and pushes it out. This characteristic allows it to provide precise flow control, making it ideal for applications in water treatment where accurate chemical dosing is crucial.

Positive displacement pumps are distinct because they move fluid by trapping a fixed amount and forcing it into the discharge, as opposed to centrifugal pumps, which work by imparting velocity to the fluid through rotational energy. The peristaltic design allows for the handling of corrosive or viscous liquids, making it suitable for various chemical feed processes.

In summary, the peristaltic pump's ability to deliver consistent and controllable flow rates while handling a range of chemicals illustrates its classification as a positive displacement pump used for chemical feeding in water treatment applications.