1.2 Coagulation and Flocculation

What is the primary purpose of coagulation in wastewater treatment?

• pH adjustment

• Removal of dissolved chemicals

• Breaking down large particles

• Formation of flocs

Which chemical is commonly used as a coagulant in wastewater treatment?

• Sodium chloride

• Sodium hydroxide

• Aluminum sulfate

• Hydrogen peroxide

What is the role of a coagulant aid in the coagulation process?

• Adjusting pH levels

• Breaking down flocs

• Enhancing particle dispersion

• Neutralizing pathogens

What is the main function of rapid mixing in the flocculation process?

• Adjusting pH levels

• Disinfection of wastewater

• Breaking down flocs

• Mixing coagulant chemicals 

Which parameter significantly affects the choice of coagulant dosage in wastewater treatment?

• Temperature

• Turbidity

• pH levels

• Dissolved oxygen levels

How does mixing intensity in flocculation affect floc size?

• Higher intensity creates smaller flocs

• Lower intensity creates smaller flocs

• Lower intensity creates larger flocs

• Mixing intensity has no effect on floc size

Which of the following is an example of a coagulation aid used in wastewater treatment?

• Sodium hydroxide

• Polymers

• Hydrochloric acid

• Sodium chloride

How does the size of flocs formed during flocculation affect sedimentation?

• Larger flocs settle slower

• Larger flocs settle faster

• Floc size has no effect on sedimentation

• Larger flocs float

How does the zeta potential of colloidal particles influence coagulation?

• Zeta potential has no effect on coagulation

• Zeta potential affects flocculation, not coagulation

• Lower zeta potential enhances coagulation

• Higher zeta potential enhances coagulation

Which coagulant is commonly used for the removal of color and organic matter from wastewater?

• Calcium carbonate

• Sodium chloride

• Ferric chloride

• Hydrogen peroxide