What is an advantage of a dual media filter?

A dual media filter is designed to utilize two different types of media, typically sand and anthracite, which work together to optimize the filtration process. One significant advantage of this design is the longer filter run times between backwashes. Each type of media has different properties that allow for improved particle removal and better retention of suspended solids. This results in a more efficient filtration process, reducing the need for frequent maintenance and backwashing.

The longer intervals between backwashes not only enhance the operational efficiency of the filtration system but also contribute to lower water wastage and operational costs. Additionally, this means that the filter can operate for a more extended period before needing to be cleaned, maximizing its performance and lifespan. Thus, the benefit of extended filter run times is a key characteristic that distinguishes dual media filters from single media filters, making B the correct choice.