What is sedimentation volume and degree of flocculation?
Degree of flocculation (β). Sedimentation volume (F) : is the ratio of the ultimate volume of sediment (Vu) to the original volume of sediment (Vo) before settling. F= Vu/Vo Where Vu is the final or ultimate volume of sediment. The system is in flocculated equilibrium and show no clear supernatant on standing.
What is the effect of suspending agent on sedimentation volume?
As the concentration of the suspending agent increases sedimentation volume and viscosity of the suspensions increased. There was faster rate of sedimentation of dispersed particles in suspensions containing 0.5% and 1% w/v of suspending agent.
How rate of sedimentation is dependent on particle size of a suspension?
The rate of sedimentation or settling for a suspended phase depends on several factors which are under the control of the formultor or pharmacist. By reducing particle size, by increasing the viscosity, and by increasing the density of the external phase, we may retard settling.
What is sedimentation volume?
Definition: Sedimentation volume is a ratio of the ultimate volume of sediment (Vu) to the original volume of sediment (VO) before settling.
What are flocculating agents?
Flocculating agents are chemical additives that cause suspended solids to form aggregates called flocs. These agents are used in water treatment, municipal and industrial waste treatment, mineral processing, and papermaking. The type of flocculant used depends on the type of solid–liquid separation being performed.
Which of the following is used as a flocculating agent in suspension?
sulphate phosphate and citrate salts.
What is sedimentation volume of ideal suspension?
A maximum sedimentation volume will be obtained when zeta potential is: In practice, an acceptable suspension should have particles: The ratio of the ultimate volume of sediment to the actual volume of sediment before settling is called. The ratio of void volume to bulk volume is known as.
What is the importance of determining the sedimentation volume of a suspension?
The sedimentation volume gives only a qualitative account of flocculation. Suspensions Important parameters of sedimentaion-Degree of flocculation The ratio of sedimentaion volume of flocculated suspension to that of the deflocculated suspension. Suspensions- porperties 1.
Does particle size affect sedimentation?
Larger particles (with identical specific mass) sediment faster than smaller particles. When particles are typically smaller than about a = 10 − 100nm, sedimentation velocities in the earth’s gravitational field are very small, and sedimentation experiments must be performed by centrifugation.
What is flocculating agent example?
The aluminum-based flocculants include aluminum sulfate, aluminum chloride, sodium aluminate, aluminum chlorohydrate, and polyaluminum chloride. The iron-based flocculants include ferric chloride, ferric sulfate, ferrous sulfate, and ferric chloride sulfate [15, 69].
Which are the flocculating agent in soil?
Sodium silicate is specified as the de- flocculating agent in the present ASTM and AASHO standard methods of mechanical analysis. Sodium pyrophosphate and so- dium metaphosphate have been found ef- fective as deflocculating agents lor many types of soil (1, 5, 6).
How is sedimentation volume determined in flocculated suspension?
(Sedimentation volume quickly decrease in flocculated suspension compared to deflocculated suspension initially but ultimate sedimentation volume of flocculated will be higher) The flocculated and deflocculated suspension is prepared and evaluated for sedimentation volume.
What can be used as a flocculating agent?
Electrolyte and ionic surfactant can be used as flocculating agents to produce a flocculated suspension.suspension prepared without flocculating agent is a deflocculated one. The physical stability of the suspension is assist by determining the sedimentation volume or degree of flocculation.
What does degree of flocculation at one HR mean?
The degree of flocculation at one hr=sediment volume of flocculated suspension in one hour/sediment volume of deflocculated volume in one hour.3
How is the control of flocculation achieved?
Controlled flocculation can be achieved by a combination of control of particle size and the use of flocculating agents. The most common categories of flocculating agents are electrolytes, surfactants, and polymers. i. Electrolytes