What is a common application of a nonionic polymer?

A nonionic polymer is primarily used as a filter aid in various applications. Filter aids help improve the efficiency and effectiveness of the filtration process by enhancing solid-liquid separation. They function by increasing the permeability of the filter cake, which allows for more rapid and efficient filtration. Nonionic polymers are particularly beneficial because they do not carry an electrical charge, making them versatile in a variety of water treatment processes, especially in situations where the presence of charged particles might disrupt the filtration process.

In contrast, other options like coagulation agents are typically ionic substances that help to aggregate suspended particles in water, leading to the formation of larger clumps that can then be removed. Flocculating agents also tend to work in a similar manner but are primarily involved in promoting the formation of flocs from dispersed particles, which is a different function compared to nonionic polymers used as filter aids. Disinfectants are chemical agents intended to kill or inactivate pathogens, which is not a role that nonionic polymers would serve. Thus, the application of a nonionic polymer as a filter aid aligns directly with its properties and how it interacts in filtration scenarios.