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INORGANIC PARTICLESORGANIC PARTICLESColloids Particles that are too light and small to settle

Turbidity State of cloudiness or hazinessRisk of Disease TurbidityFlocculationPresented by : Group 3Flocculation

Process whereincolloidscome out ofsuspension in the form of floc or flake; either spontaneously or due to the addition of aclarifying agent (Flocculant).

Alum [ Al2(SO4) 3 ] Ferrix [ Fe2(SO4) 3 ]Typical Flocculant

How Flocculation WorksColloidFFFPositive Charges of WaterColloidColloidColloidColloidFFFFFFFFFFFFJar-Test Apparatus

Test in Flocculation It simulates the coagulation/flocculation process in a water treatment plant and helps operators determine if they are using the right amount of treatment chemicals

Jar-Test Apparatus

Phases/Stages in FlocculationPhases/Stages in FlocculationRapid or Flash mixingis the process by which a coagulant is rapidly and uniformly dispersed through the mass of water. This process usually occurs in a small basin immediately preceding or at the head of the coagulation basin. Generally, the detention period is 30 to 60 seconds and the head loss is 20 to 60 cms of water. Here colloids are destabilized and the nucleus for the floc is formed.Phases/Stages in FlocculationSlow mixingbrings the contacts between the finely divided destabilized matter formed during rapid mixing.

Mechanisms in FlocculationPerikinetic Flocculation

Mechanism in Flocculation

Perikinetic FlocculationRefers to flocculation (contact or collisions of colloidal particles) due to Brownian motion of colloidal particles. The random motion of colloidal particles results from their rapid and random bombardment by the molecules of the fluid.Orthokinetic Flocculation

Left: vertical paddleCenter: horizontal (reel) paddle Right: axial flow

Mechanism in Flocculation Orthokinetic Flocculationarises from induced velocity gradients in the liquid. It is here that primary particles are induced to approach close enough together, make contact and progressively form larger agglomerates, or flocs. The principal parameter governing the rate of orthokineticflocculation is the velocity gradient applied.

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