Which best describes flocculation?

Flocculation is best described as the agglomeration of particles into larger particles through gentle mixing. This process often occurs in water treatment and other industrial applications where fine solids or particles are suspended in a liquid. By applying gentle mixing, small particles collide and bond together, forming larger clusters known as flocs. This is crucial for the clarification of liquids as these larger flocs can then be more easily removed from the liquid through sedimentation or filtration.

While the other choices contain elements related to particle interactions or treatments, they do not precisely capture the essence of flocculation. The option about neutralizing electrical charges refers to coagulation, which is often part of the treatment process leading to flocculation but is distinct in that it usually involves the addition of chemicals to promote particle clumping due to charge neutralization. The description regarding the reduction of suspended matter may be part of the broader settling process post-flocculation but does not define flocculation itself. The last option related to adjusting pH is relevant in water treatment but does not describe the mechanism of flocculation.