Water is vital to all of us, especially pure drinking water. In the first world it isn’t something that we usually think about. You just turn on the tap and there it is, your drinking, bathing and washing water. There are adequate systems of water delivery that include reservoirs, water softeners, water ionizers, water purification methods, and tubing. But what if that system isn’t maintained correctly or breaks down for one reason or another? Many third world countries have those systems too, but the purity of the water cannot be trusted. Then you will want to know that your tap water is safe and how to purify water. In some places there aren’t these elaborate systems and people rely on lakes, rivers or wells for their drinking water. For those people, it is very important that they can trust the water they drink. That’s the reason why all of us should know a little about how to purify water, just in case.
Although some water purification methods are better suited to large scale endeavours, it is also good to know how to purify water on a small scale in emergency conditions, if the water source becomes contaminated. Sadly, over one billion people worldwide don’t have access to safe drinking water and for that reason, it is a major issue that has created much research and development around it. There are international standards of water purity, but most standards are set by individual governments. Sometimes these standards fall short. Remember, dehydration because of lack of clean drinking water is also a killer, not only the various waterborne diseases that it can carry.
Different Water Purification Methods
- Boiling: this is the oldest, tried and tested method. Bringing the water to boiling point for ten minutes or so, should get rid of almost all the harmful contaminants in the water. Those that are left rarely cause harm to humans. Of course, a percentage of the water is lost through steam evaporation. This method is fine if your water source is near, but may be costly in terms of fuel consumption, which may also be a scarce resource.
- Distillation: another boiling method that turns the water into steam or vapour. The vapour is channeled into another cooler vessel and condenses, which makes it turn back into liquid again. Not a complete purifying method, but it is 99.9% safe. Again, it is heavy on heating fuel but you will get all the benefits of purified water.
- Reverse Osmosis: this is used in large scale water purification. Water is forced under pressure through a specially built membrane. A good method for recycling used water. In theory, it is supposed to be the best method. If not maintained correctly, algae can accumulate on the membranes. Absolutely useless for small scale or a household method of purification.
- Distillation: used in hot and arid countries with little rainfall or water sources. Turning salt water into fresh water. Another large scale undertaking, which means piped or bottled water becomes very expensive.
- Iodine: iodine is a quick and easy way to purify. Easy to transport because it comes in tablet, solution or crystal form, great for household use or other small scale purifying. Strain out any visible particles beforehand, drop in a tablet or a few drops and wait. Any packet will come with instructions on quantities. Works better with warmer water. Wait 30/50 minutes or so, depending on the quantity of water, and it is safe to drink. Can have side effects for some people, such as headaches and nausea. Iodine can be stored up to 6 years.
- Chlorine: like Iodine, it comes in tablet or liquid form, but the tablet form is considered more effective. It also comes in two types-Sodium and Dioxide. Sodium-add to the water in a closed container and wait for 30/45 minutes. It has a shelf life of up to 5 years. Dioxide- exactly the same, but it takes up to 4 hours to purify the water. The tablets will keep for 4 years. Like Iodine, they are good for emergency home use or even travel. The military is usually equipped with these types of personal water purification methods. They are also cheap to buy.
- Ultra-violet Light: another small scale water purification method that is easily done. Of course, this works better with lots of sunlight. Fill a bottle, clear glass or plastic and set it in the sun. It takes about 6 hours to purify a one litre container. Strain the water first. The ultra-violet rays will kill almost all of the harmful bacteria. Unfortunately, it won’t remove harmful chemicals.
- Solar: this is the same as ultra-violet light purification, using the same principle. It is a combination of radiation and pasteurization (boiling). An upgraded and household scale UV system that uses the sun’s rays and heat. Also called SoDis. The bottled water is heated to between 70 -75 degrees Celsius by using cookers or reflectors. Designed for use in rural areas where water is scarce and there is constant sunlight. Relies solely on renewable energy and is dependent on the weather, but is very low on costs.
- Household Chemicals: a common household chemical to use in purifying water is bleach. A bottle of simple, clear bleach can be used. Eight drops of bleach added to one gallon of water will purify it in 30 minutes, destroying almost all harmful bacteria. Iodine can also be used, but it takes no less than 20 drops to the gallon.
How to Build Your Own Water Filter
It is recommended to use a faucet water filter to purify the water in the first place. And, you can easily create a DIY water filter too. Upend a plastic bottle, but keep the cap screwed on. Cut off the bottom of the bottle. Stuff a cloth or clean rag into the neck. Fill the end with used charcoal, suitably smashed into tiny bits. On top of that, pour a thick layer of sand. Then, a layer of gravel. It would be well to wash all the components thoroughly beforehand. Pour in water and wait. The water will seep down through the layers and collect in the neck. Open the cap and let the water out. That’s it, your very own rough and ready bio water filter. You can decide which size bottle you use or you can find bigger containers and increase the volume.
For people who live in an urban setting, water purification isn’t something they normally think about, but that will depend on in which country they live and the standard of water purity. In the face of ongoing climate change, it may be prudent for urban dwellers, as well as rural, to start thinking of the consequences of a disrupted or contaminated water supply. Unforeseen events may lead to emergency conditions where clean water supply is of vital importance. This may be something to think about. There is an abundance of commercially manufactured purification systems, you just need to choose which suits your purpose or budget. Of course, you can also go DIY and make your own.