Which statement about coagulation is true?

Which statement about coagulation is true?

• A. It primarily removes dissolved ions by chemical reaction.
• B. It is followed by disinfection as the first step.
• C. It destabilizes colloidal particles to form flocs.
• D. It only affects taste.

Answer: (C)

Coagulation works by neutralizing the electrical charges on tiny suspended particles so they lose their stability and can come together into larger aggregates. When coagulants add multivalent ions (like aluminum or iron salts), they neutralize the negative surface charges of colloids, reducing the electrostatic repulsion that keeps them apart. As these particles can now collide and stick together, they form larger clumps called flocs. These flocs are then easier to remove in subsequent steps like sedimentation and filtration, improving water clarity and color. That’s why the statement about coagulation is true: it destabilizes colloidal particles to form flocs. It’s not mainly about removing dissolved ions, disinfection comes later in the treatment train, and coagulation affects more than just taste, primarily targeting turbidity and suspended solids.

Coagulation works by neutralizing the electrical charges on tiny suspended particles so they lose their stability and can come together into larger aggregates. When coagulants add multivalent ions (like aluminum or iron salts), they neutralize the negative surface charges of colloids, reducing the electrostatic repulsion that keeps them apart. As these particles can now collide and stick together, they form larger clumps called flocs. These flocs are then easier to remove in subsequent steps like sedimentation and filtration, improving water clarity and color.

That’s why the statement about coagulation is true: it destabilizes colloidal particles to form flocs. It’s not mainly about removing dissolved ions, disinfection comes later in the treatment train, and coagulation affects more than just taste, primarily targeting turbidity and suspended solids.