Reverse Osmosis And Nanofiltration Pilot

Description

The water passage continues until a balance condition is reached. This is achieved when the level difference between the two solutions is equal to the osmotic pressure of the concentrated solution. If a pressure stronger than the osmotic pressure is applied to the concentrated solution, the phenomenon is reversed the water permeates from the more concentrated to the most diluted solution across the membrane. This is the reverse osmosis which is used in water desalination, where the water to be desalinated represents the most concentrated solution. The molecules and ions larger than 10-7 are retained by the membrane while the solvent water molecules pass through.

The Nano filtration is a pressure driven separation process. The filtration process takes place on a selective separation layer formed by an organic semipermeable membrane. The driving force of the separation process is the pressure difference between the feed (retentate) and the filtrate (permeate) side at the separation layer of the membrane. However, because of its selectivity, one or several components of a dissolved mixture are retained by the membrane despite the driving force, while water and substances with a molecular weight < 200 D are able to permeate the semipermeable separation layer.
Taking advantage of the similar hydraulic conditions for the functioning of the modules, this pilot use processes of reverse osmosis and nanofiltration.

Teaching objective

Study of performance according to the hydraulic parameters around the membranes.
Study of performance according to the nature of the polluting elements and their concentration.

Technical specifications

Spiral and organic membrane and its polyester housing resistant to 21 bars (S = 0,24 m2) for reverse osmosis.
Spiral membrane with polyester housing resistant to 21 bars for nanofiltration.
304 inox, multicellular, centrifugal pump.
Supply tank with PVC cover.
Permeate receptacle with PVC cover.
3 PVC flowmeters.
2 manometers diam 100 mm.
Conductivity meter with probe, digital display.
Activated charcoal filter (detachable housing, disposable cartridge) 25µm filters + 3 manometers (behind the unit)
Control panel including pump control and protection, conductivity meter transmitter, general switch.
PVC piping and stainless steel frame.