What media is used to remove up to 90 percent of organic matter for secondary sewage treatment?Group of answer choicesBacteriaSolventsActivated carbon

In secondary sewage treatment, the primary media used to remove organic matter are bacteria. This biological treatment process primarily relies on bacteria to break down organic pollutants present in wastewater. These microorganisms utilize the organic materials as a food source, effectively reducing the concentration of organic matter in the effluent.

Other options like solvents and activated carbon play roles in different contexts of water treatment. Solvents are typically used for chemical treatment purposes, and while activated carbon is effective for adsorbing organic compounds, the most significant reduction of organic matter during secondary treatment is accomplished through bacterial processes such as activated sludge systems or biofilters.

In summary, bacteria are the key agents used in secondary sewage treatment to achieve the substantial removal of organic matter.