Microbes in Sewage Treatment

The video explains the process of sewage treatment, which involves removing contaminants from wastewater through primary and secondary treatments. Primary treatment mechanically removes solid waste, while secondary treatment uses biological processes to reduce organic content and BOD. The final steps include anaerobic digestion to produce biogas and chemical disinfection before releasing the treated water back into natural bodies.

What is the primary concern with untreated sewage?

• It can be directly consumed by humans.

• It may cause diseases due to pathogenic microbes.

• It can be used as fertilizer.

• It is beneficial for aquatic life.

What is the composition of sewage in terms of water and solid waste?

• 100% solid waste.

• 50% water and 50% solid waste.

• 99% water and 1% solid waste.

• 75% water and 25% solid waste.

What is the main goal of primary sewage treatment?

• To increase the water temperature.

• To remove dissolved gases.

• To mechanically remove undissolved solid impurities.

• To chemically disinfect the water.

During secondary treatment, what role do aerobic microbes play?

• They remove heavy metals.

• They add nutrients to the water.

• They consume organic matter, reducing BOD.

• They increase the water's temperature.

What is BOD a measure of?

• The amount of solid waste in the water.

• The pH level of the water.

• The temperature of the water.

• The amount of dissolved oxygen consumed by aerobic microbes.

What is the purpose of the anaerobic sludge digester?

• To increase the water's pH level.

• To remove dissolved oxygen.

• To add chlorine to the water.

• To digest organic matter in an oxygen-free environment.

What is the final step before treated water is released into natural bodies?

• It is mixed with untreated sewage.

• It is heated to a high temperature.

• It is chemically disinfected.

• It is filtered again.