How to purify water

A large part of Europe makes use of fresh water by the best reverse osmosis system. But there are also areas, such as near the coast, where there is nothing else to be found than salt water. Depending on the purpose for which one wants to use the water, a positive quality is demanded.

Both on the surface and in the source water are often elevated parameters which can cause problems in the utilization of this untreated water.In a laboratory is investigated, the untreated water on several parameters. These parameters provide insight into the water.

The quality you want of water after water treatment depends on the purpose for which the water is to be used. It is of particular importance for cleaning work, for example, that there is no deposition takes place, as a result of certainly elevated values. For example, iron (Fe) can provide a brown deposit on tiles, paving, and walls. A similar effect cause the values manganese (Mn) and Lime (* DH). Manganese gives a black and lime deposits give a white to yellowish deposits. Think of the white, yellowish limescale in the kettle or tile in the bathroom. Values such as NaCl (salt) and a low Ph materials can corrode quickly.

Regarding water quality standards after water treatment is to make the following breakdown:

  • 1.0 Human consumption – Drinking Decision 2011
  • 2.0 Industriewater Standards – Water Standards in areas such as printing presses (Demi water)
  • 3.0 Animal use – Water Standards HINTS health and production of animals subdivision:
  1. Drinking water for cattle/fattening bulls
  2. Drinking water for dairy cows
  3. Drinking water for calves
  4. Drinking water for white veal calves
  5. Drinking water for pigs for fattening
  6. Drinking water for chickens for fattening
  7. Drinking water for laying hens
  8. For horses drinking water

Several modern water treatment systems such as:

  • Open water treatment
  • Closed water treatment
  • Nano-filtration
  • Osmosis filtration
  • Ion exchangers

Reverse osmosis water treatment systems are by far the most suitable to be sure of pure water

The water is squeezed out under pressure against a semi-permeable membrane that lets the water leaving behind substances. These are discharged, and the purified water is stored in a tank. Reverse osmosis membranes work actually in the reduction of heavy metals such as lead, mercury and arsenic, but also to pesticides, herbicides, and nitrates.


Osmosis comes from the Greek word “kosmos” which means “push.” Osmosis is a single flow of liquid through a semi-permeable wall (our skin is also semi-permeable, as we were sweating, the moisture through the skin comes away as if we sit in the bath penetrates the bathwater not the body through the skin within).
Is located on the side of the membrane, pure water, and on the other hand with water, for example, a sugar solution, then calls the clean water using osmotic pressure through the membrane to the side of the sugar solution.

Reverse osmosis

The word says it all. We reverse the process. By exerting pressure on the water with the sugar solution, we return to the process. The water is squeezed out in the opposite direction through the membrane leaving behind the sugar.

Why activated carbon filters are used in combination with reverse osmosis? Reverse osmosis membranes have an enormous ability to remove a broad spectrum of impurities. However, there are some limitations that should not be overlooked. Some fabrics are too small or have such a structure that they can not be removed by the reverse osmosis process. These include some carbon compounds with a low molecular weight, chlorine compounds, and dissolved gasses. By using an active carbon filter, these substances can be removed effortlessly. There are two carbon filters are placed, one in front of the membrane and one behind the membrane and the storage tank.

The quality

The yield and quality are dependent on the pressure and temperature of the inlet water. The higher the pressure, the better the efficiency, and quality. The test data are based on a pressure of 66 psi (4.5 bars) and a temperature of 25 degrees Celsius. The systems do not remove everything but working in proportions of e.g. 97% of the feed water.


And saturate filters have a limited life and may cause membrane fouling. This may deteriorate the quality and the capacity of the purified water. By measuring the resistance of the feed water and the purified water can be calculated if the quality is still optimal. The storage tank of pure water also needs maintenance. It is recommended to empty the tank once a week by opening the sink faucet.

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