In distress, especially in hot areas and desert areas, water supply is crucial.
⑴ Water source
The natural water sources include the following:
·Surface water: such as rivers, lakes, streams, etc.
·Groundwater: such as well water, spring water, underground reservoirs, etc.
·Biological water: For example, some plants contain sufficient water, such as fairy banana, bamboo, cactus, etc.
· Water in the sky: such as rain, snow, dew, and melted ice.
Rain water, spring water, well water, and mountain stream water can be directly drunk. However, static or slow-moving water contains a lot of organic matter and bacteria and needs to be purified before drinking. Purification is the elimination of organic matter in the water, disinfection, and removal of peculiar smells. In distress conditions, the following simple methods can be used to purify drinking water.
·Find a container, such as a canvas bag, a polyethylene plastic bag, a large tin can, and one end sock, can all serve as a container?
· Spread a layer of fine gravel on the bottom of the container, then a layer of sand and a layer of charcoal powder. Repeat this many times. The more layers the better, each layer is about 2.5 cm thick. If there is no sand, use fine gravel instead.
·Drill some small holes in the bottom of the container, pour water into the container, and use a cup to hold it underneath.
·In addition, there is another way to purify the water. Dig a shallow pit half a meter away from the water source. After some time, clear and clean water will seep out of the pit.
·Boil sterilization. At sea level, boil for at least 1 minute; in higher altitude areas, the time should be extended, and the boiling time can be increased by 3 to 4 minutes for every 1000 meters of altitude increase.
·Chemical disinfection. Disinfectants include dichlorosulfabenzoic acid, iodide, and halazone. Put 2 tablets of dichlorosulfabenzoic acid in 1 liter of water and let it stand for 15-30 minutes to achieve the purpose of disinfection. Without this agent, 8-10 drops of iodine per liter of water can be sprinkled.
If you want to kill bacteria, you must do one of the following methods:
·Water purification tablets are the easiest to use. Before you enter the desert, you can buy some from a pharmacy and follow the instructions for the tablet. Not only do you need them in self-rescue and avoid danger, cars and airplanes, but you should also keep some at home for emergency use.
Under normal circumstances, 1 tablet of water purification tablets is enough to purify 1 liter of water, and 2 tablets can purify 1 liter of turbid water. Allow the purified water to settle for 30 minutes before use.
·Iodine add 3 drops per liter of water, turbid water doubles. Set aside for 30 minutes.
·Household bleach (5.25% sodium chlorite) per liter of clean water add 2 drops, muddy water add 4 drops. Shake the water for a while and use it after settling for 30 minutes. The bleached water will have a slight chlorite smell. ·Boil water for 3 to 5 minutes to purify it.
·Add a little carbon to the water, and at the same time boil the water to remove the color. Stir the water to cool it down and restore its flavor or add a pinch of salt.