Categories

REVERSE OSMOSIS

REVERSE OSMOSIS SYSTEM TYPES

Reverse Osmosis Water Filter Systems including Wall mount laundry reverse osmosis, Undersink reverse osmosis, Countertop reverse osmosis, commerical reverse osmosis, all with lower waste ratios.

Countertop reverse osmosis systems. These are convenient for the person that wants a system in the kitchen, is low in cost and attaches to the aerator thread of their kitchen spout or tap. Suitable for persons that rent as it will leave no marks after you leave. The countertop system will produce water at around 350ml per minute.

Laundry reverse osmosis is normally fitted in the laundry as an easy way of obtaining a convenient water source by way of the cold water washing machine tap via a supplied adapter which doesn’t interfere with the washing machine operation. To operate you simply turn on the supplied ball valve and the systems will make RO water at about a cup of water a minute, you will need to collect the water into a container of some type for use elsewhere.

Undersink reverse osmosis has the convenience of being hidden away in the cupboards under or near the sink and supplying water to a dedicated tap (faucet) fitted through the sink or bench top. Undersink RO’s have a pressurised storage tank and deliver the water quickly at around 3 to 4 litres per minute depending on the mains water pressure. This type of system doesn’t produce the water any faster than the other types but is totally automatic in operation and keeps it’s storage tank in a constant state of top-up. When you turn the faucet on the sink on it comes out quickly from the storage tank, the system turns it’s self on, replaces what you took from the tank and when the tank is full again it automatically turns it’s self off again, this is done with out power as it uses the pressure in the mains to operate a system of check valves, piston and diaphragms to turn the water on and off to the system.

Reverse Osmosis (RO) is a process where water is treated using a semipermeable membrane at pressure. Reverse osmosis is osmosis in reverse. Osmosis is most mostly observed in plants. If you don't water your plants they die. A plant cell is a semipermeable (water flows through the membrane but contaminates and salt don't) membrane with the living part on the inside in a salty/sap solution. Water is drawn into the cell from the environment because pure water will move across a semipermeable membrane. This is how water is drawn in from the soil when you water your plants. If you salt your plants (over fertilize or spill some salt on the grass), the plant will wilt because the salt concentration on the outside of the cell is higher than the inside and water then moves across the membrane from the inside to the outside. Reverse osmosis is reversed because contaminated water (salty) is drawn naturally towards clean water so it is placed under pressure to obtain the purified water and reject the contaminated. If this sounds a bit strange consider that hot water is naturally drawn towards cold water not the other way around.

Osmosis is a natural process and reverse osmosis was used long ago in the Middle East. Contaminated water was placed into goats bladders that had been stitched together to create a long type of sock shape and the contaminated water put within. The water slowly dripped through the bladders and purified the water making it drinkable.

Here at PSI Water Filters we sell many types of filter systems but consider reverse osmosis the best as it will remove the most contaminates possible. We do read some web sites around that try to discredit reverse osmosis as these companies are not selling a wide Varity of different systems and even go as far as creating what appears to be information web sites and discrediting any process that differs from what they are selling even going as far as comparisons from different brands of the same type of systems but only choosing models that don’t compare favourably with theirs and excluding manufacturers that do.

The modern reverse osmosis systems don’t use anything like goats bladders as the membrane material, a modern reverse osmosis membrane is made from what is called Thin Film Composites (TFC) also called polyamide (PA) membranes. These membranes filter the water at around 0.0005 microns, which is about ½ a millionth of a millimetre, it is so fine that it can strain salt out of the water. The RO membranes work down to the molecule structure of water (H2O), if a molecule of water has an extra atom attached such as a carbon atom the molecule is too large to fit through the membrane and is rejected and goes down the contaminated water line which is commonly referred to as the waste line and expelled from the system. Pure water molecules which are (H2O) are small enough to slip through the membrane (leaving behind the contaminated water molecules) and into the RO product line for you to use.

Substance

% rejection

Substance

% rejection

Aluminium

96-98

Fluoride

96-98

Sodium

92-98

Bromide

90-95

Magnesium

93-98

Cyanide

93-97

Potassium

92-96

Sulfate

96-99

Calcium

93-99

Thiosulfate

96-98

Manganese

96-98

Silicate

92-95

Iron

96-98

Silica

95-98

Copper

96-99

Nitrate

93-98

Nickel

96-99

Polyphosphate

96-98

Cadmium

93-97

Orthophosphate

96-98

Silver

93-96

Chromate

90-95

Zinc

97-99

Bacteria

>99

Mercury

94-97

Lead

96-98

Hardness Ca&Mg

93-97

Arsenic

90-98

Radioactivity

93-97

Medications

97-99

Chloride

92-98

Chlorofoam

71-90

Ammonium

85-90

Tin (11) Sulfate

83-87

PCB’s

97-99

PBA’s

96-98