Many residents of large cities use special filters for additional purification of drinking water. The device can be stationary: the filtration system itself is usually located in a cabinet under the sink, and an additional tap is brought out for purified water. Or compact - in the form of a jug. However, during outdoor recreation, you cannot be absolutely sure of the quality of drinking water taken from natural sources. A simple filter for water purification can be made independently from scrap materials.
- - plastic bottle (1.5-2 l);
- - a sharp knife;
- - twine;
- - gauze or unpainted cotton fabric;
- - cotton wool;
- - non-coniferous charcoal;
- - a small piece of silver;
- - ascorbic acid.
Pour water into a bucket or other container and let sit for a couple of hours for the water to settle. Debris will either settle to the bottom or float on the surface of the water - try to remove them carefully. Pour water into the filter carefully, pour out the residue with sediment from various impurities.
While the water is settling, prepare the main filter element. Take a plastic bottle and cut off the bottom with a sharp knife. The plug can also be removed - you do not need it. You should end up with something like a funnel.
In the upper part, make 2 holes, symmetrically relative to the center of the bottle, about 4-5 cm away from the edge of the funnel. Thread the twine and tie the ends to make a handle-like loop. For it, you can hang the filter, for example, on a tree branch.
Place layers of filter material in the filter blank, starting from the neck of the funnel, moving up to the base of the bottle:
1. gauze or thick fabric;
2. cotton wool;
3. gauze or thick fabric;
4. charcoal (birch is best);
5. gauze or thick fabric;
6. cotton wool;
7. gauze or thick cloth.
The cotton-gauze layer can be replaced with a lutrosil-type non-woven material folded in several layers.
Water that has passed through such a filter will only be mechanically cleaned. To make it suitable for drinking and cooking, you need to take care of its disinfection.
First, boil the water for 10-15 minutes. This time is quite enough to protect yourself from most of the bacteria that may be contained in the water. You should also not boil the water longer, because during boiling, part of the water will evaporate and the concentration of harmful substances (for example, heavy metal salts, etc.) will become much higher, which will deteriorate the quality of the water.
Since ancient times, people have used the bactericidal properties of silver to improve water. To do this, put a small object made of this metal in a vessel with water - a chain, a spoon, a glass.
Many pathogenic bacteria cannot tolerate an acidic environment, therefore, for health safety reasons, the water can be slightly acidified, for example, with ordinary ascorbic acid.
In winter or in the presence of a freezer, you can use melt water for cooking, I also call it "live".
Take a container that can be frozen, pour in water, mechanically cleaned of impurities. Place in the freezer and wait for about 2/3 of the water to turn to ice. Pour out the remaining unfrozen water, melt the ice and use the melt water as directed.