What is one of the steps used to control the filter on a trickling filter?

Chlorinating the filter is an effective practice for controlling the filter on a trickling filter system. This process involves adding chlorine to manage the growth of pathogens and to reduce the potential for odor and biofilm issues on the media. Chlorination can help maintain a balanced microbial population essential for the proper functioning of a trickling filter, as excessive or harmful bacteria can disrupt the filtration process.

In contrast, draining the filter for an extended period may lead to unfavorable conditions for the microorganisms that are necessary for biological treatment, potentially harming the overall performance of the system. Changing to a new type of media can be an extensive measure and is not typically part of routine maintenance unless the current media is failing. Fumigating the filter and surrounding area with pesticides is generally not an accepted practice in wastewater facilities due to the potential negative impact on the ecosystem and the microorganisms that benefit the treatment process. Thus, chlorination stands out as a specific, practical method for maintaining control over trickling filters.