For most people, it goes without saying that water tapopen and take a drink of hygienic drinking water without worrying about their health. In other countries, however, such a thing is not self-evident. Even in Germany there are farmhouses that are not connected to any central drinking water supply. In such cases or when traveling, it may be necessary to sterilize the water before use.

What is the purpose of water sterilization?
Various methods are used to remove harmful substances from the water. These are for example.
– coarse contaminants such as sand, mud, dirt
– chemical substances dissolved in the water
– harmful organisms such as viruses, bacteria, fungi, algae or parasites
The aim of water sterilization is to obtain hygienic water suitable for drinking, cooking and brushing.

Which methods are used?
This depends primarily on what the water is contaminated and what it should be used for. For domestic water for washing, bathing and cleaning, the requirements are lower than for drinking water.

water purification tablets
These funds are probably the best known and are used, for example, by backpackers or members of the armed forces. The tablets kill microorganisms in the water. There are 2 types of sterilization tablets. Those based on chlorine and those based on silver ions. Chlorine tablets are very effective, but produce the typical taste of chlorine. Means with silver ions are tasteless, but do not kill the germs, but only prevent their growth. That is why they are only suitable for the preservation of drinking water, not for sterilization.
Water sterilization tablets are easy to use but can only kill microorganisms, they will not remove impurities.

water filters
There are different types of water filters. Often it is sufficient to filter contaminated water through a thick layer of gravel or sand to get clean drinking water. Not only a mechanical filtering, but also a biological clarification of the water takes place.

Ion exchangers can remove dissolved ions from the water. They are mainly used to reduce water hardness. Ion exchangers remove unwanted ions such as magnesium or calcium and replace them with sodium ions.

Activated carbon is a granulate of very fine-pored charcoal, The grainshave a very large surface area and are able to bind a number of dissolved organic substances. These include, for example, residues of pesticides or medicines. Salts, lime or minerals, on the other hand, can not be retained by activated carbon filters.

ceramic filter
These water filtersuse cartridges of fine-pored ceramic, through which the water is pressed. The pores of the filter are smaller than bacteria, unicellular or fungal spores, which are therefore retained. However, viruses can pass the pores, although at least their number is reduced.

What are the disadvantages of the different methods of water sterilization?
None of the methods works perfectly or can remove all types of pollution. In order to get safe, edible drinking water, different methods have to be combined. For example, experts recommend aftertreatment of the treated water with UV light in most processes, which kills germs. The cartridges of all filters only work for a limited time. After that they have to be replaced or regenerated. Ceramic filters must be boiled at regular intervals. If this is not done, used filter cartridges even contaminate the water instead of cleaning it. For devices that use power, the problem is finding replacement batteries or power to charge the battery.

Are there alternatives to water sterilization?
The water can first be filtered through a dense cloth to remove coarse contaminants. After that it must be boiled for several minutes. Another option is to add a small amount of chlorine to the water bleach(used for laundry bleaching). You can also dodge bottled mineral water and use it not only to drink and cook, but also to brush your teeth.