What is the primary benefit of biological treatment methods?

The primary benefit of biological treatment methods lies in their use of microorganisms to effectively break down organic matter present in wastewater. This process leverages the natural metabolic activities of bacteria and other microorganisms, allowing them to consume and digest organic pollutants, which significantly reduces the biological oxygen demand (BOD) of the wastewater.

Biological treatment methods, such as activated sludge processes, trickling filters, and membrane bioreactors, are favored because they can handle high loads of organic material efficiently, promote the stabilization of waste, and enhance the overall quality of the effluent. This treatment aligns with environmental sustainability by using natural processes to mitigate pollution rather than relying on chemical treatments, which may introduce additional contaminants.

Other methods may involve extensive mechanical equipment, utilize chemical reactions to treat wastewater, or produce solid waste that must be managed. However, the hallmark of biological treatment is its ability to convert organic matter into less harmful substances while minimizing the need for harmful chemicals, making option B the most appropriate choice.