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This pilot represents the most traditional separation process of physico-chemical water treatment : filtration in mass as opposed to filtration on support (Filter Press).


A fluid containing solid particles flows through a porous environment. The spaces between the particles must be clearly larger to the particle sizes in suspension. During the route through the bed, the particles in suspension connect with those of the bed and strick to them progressively.
Filtration in the mass is often used like a pre-treatment before the stages of flocculation or coagulation. It enables eliminatIon of most particles in suspension (sediments, precipitate, coagulants,...). The most frequently used Filter materials are sands and anthracite.


Teaching objectives

- Study of sand bed porosity.
- Study of water flow in a porous substrate.
- Verification of Darcy’s Law.
- Detemination of the permeability B, for a same depth of water in the column. One can vary the flow rate and measure the head losses in the bed and then draw the curves P = f(Q).
- Study of the filter saturation.
- Determination of the curves P = f(Q).
- Study counter-current washing efficiency.


Technical specifications

- Feed tank in transparent PVC with drainage and lateral tapings.
- Stirrer with electronic speed variation.
- Altuglass column.
- Centrifugal pump in polypropylene.
- Flowmeter
- 16 Piezometric tubes allowing the measurement of load losses in a sand bed, the tubes are spaced every 5 cm along the column.
- Board graduated in millimetres.
- Electrical control panel including pump control with safety protection and stirrer speed driver
- PVC piping and stainless steel frame and aluminium nuts.



1400 x 830 x 1900 mm


Essential requirements

Power supply : 220 V / single phase / 50 Hz - Power consumption : 500 W max.
Example of Solution to use : CuSO4 10-3 M with lime (50 mg/l),
Sand bed : H = 60 cm - Int diam = 10 cm Granule size : 0.8 < d < 1.5 mm


MP31 diagram - click to enlarge :