Which term best describes conventional municipal wastewater treatment focusing on biological degradation of organics?

Which term best describes conventional municipal wastewater treatment focusing on biological degradation of organics?

• A. Tertiary Sewage Treatment
• B. Secondary Sewage Treatment
• C. Septic Tanks
• D. Wetland-Based Treatment Systems

Answer: (B)

Biological degradation of organics in municipal wastewater happens during the secondary treatment stage. After the initial primary step removes settleable solids, secondary treatment relies on microorganisms to metabolize the dissolved organic matter, cutting the biochemical oxygen demand (BOD) and overall pollutant load. Common methods include activated sludge and trickling filters, which vigorously promote microbial activity to clean the water before any polishing steps. Tertiary treatment would be the next, more advanced stage that often targets nutrients and disinfection. Septic tanks are on-site systems used for individual homes or small communities rather than conventional municipal treatment, and they rely more on anaerobic processes. Wetland-based systems are natural or engineered setups that can serve as polishing or alternative treatments but aren’t the standard description of conventional municipal secondary treatment. So the term that best fits conventional municipal wastewater treatment focused on breaking down organics biologically is secondary sewage treatment.

Biological degradation of organics in municipal wastewater happens during the secondary treatment stage. After the initial primary step removes settleable solids, secondary treatment relies on microorganisms to metabolize the dissolved organic matter, cutting the biochemical oxygen demand (BOD) and overall pollutant load. Common methods include activated sludge and trickling filters, which vigorously promote microbial activity to clean the water before any polishing steps.

Tertiary treatment would be the next, more advanced stage that often targets nutrients and disinfection. Septic tanks are on-site systems used for individual homes or small communities rather than conventional municipal treatment, and they rely more on anaerobic processes. Wetland-based systems are natural or engineered setups that can serve as polishing or alternative treatments but aren’t the standard description of conventional municipal secondary treatment.

So the term that best fits conventional municipal wastewater treatment focused on breaking down organics biologically is secondary sewage treatment.