Secondary treatment

What is the primary purpose of secondary treatment in wastewater management?

• Removal of large solids

• Reduction of organic content and suspended solids

• Neutralization of acidic wastewater

• Removal of heavy metals

Which of the following processes is commonly used in secondary treatment?

• Chlorination

• Filtration

• Biological digestion

• Chemical precipitation

In activated sludge systems, what is the purpose of the aeration tank?

• To remove large debris

• To allow biological organisms to degrade organic matter

• To filter solids

• To separate sludge from water

What is the main difference between a trickling filter and an activated sludge process?

• One is a physical treatment; the other is biological

• Trickling filters use a fixed medium; activated sludge uses organics matter

• Activated sludge is faster than trickling filters

Which type of microorganisms are primarily used in the biological treatment of wastewater?

• Algae

• Bacteria

• Protozoa

• Fungi

In which secondary treatment process are microbes attached to a media where wastewater flows over the media?

• Activated sludge

• Trickling filter

• Anaerobic digestion

• Membrane filtration

What is the process called where microorganisms break down organic matter in the absence of oxygen?

• Composting

• Aerobic digestion

• Oxidation

• Anaerobic digestion

In wastewater treatment, activated sludge is mainly used for:

• Removing heavy metals

• Disinfecting water

• Filtering large debris

• Breaking down organic matter aerobically

Which of the following is not a step in the biological treatment of wastewater?

• Sedimentation

• Aeration

• Sludge digestion

• Chlorination

Which of the following indicates good performance of an activated sludge process?

• • Clear and non-turbid effluent

• • A high sludge age

• • Minimal foaming in the aeration tank

• • Dark brown sludge color