Which type of organic material is resistant to conventional wastewater treatment methods?

Refractory organics are organic materials that resist breakdown by conventional wastewater treatment methods such as biological processes. These compounds are typically complex in structure, often containing aromatic rings, and possess characteristics that make them less accessible to microorganisms used in treatment systems. As a result, they do not decompose readily in wastewater treatment plants, leading to their persistence in the environment.

Biodegradable organics, on the other hand, can be effectively broken down by microorganisms, making them suitable for treatment processes. Suspended solids are physical particulates, which may also be removed through sedimentation or filtration, and heavy metals, though problematic in wastewater, are not organic materials. Thus, the correct identification of refractory organics highlights their significant challenge in wastewater treatment due to their resistance to biological degradation.