Water purification is a process to remove harmful substances from the water. The harmful substances in the water include a variety of hidden contaminants, from viruses and bacteria, to lead, nitrates, arsenic, perchlorate, and chloramine. Water purification is a necessity because these substances may cause great harm to the human body once ingested. Organic or bacterial contaminants such as chloride or bacteria are not easily determined with human senses. Water purification prevents the water from causing harm to the person drinking or using it.
The most common water purification process is the water filter, but purification tablets may be used as well. In circumstances of heavily contaminated water, both processes can be used to purify the water.
What Is the Purpose of Water Purification?
The main purpose of water purification is to clean the water, making it drinkable. The harmful substances in untreated water include a variety of contaminants, such as viruses, bacteria, parasites, pesticides, heavy metals, fertilizers, animal and human waste. Very often, these hidden contaminants are not visible to the naked eye and may cause a variety of problems if left untreated. Untreated water may cause multiple diseases when ingested such as stomach cramps, diarrhea, and vomiting. In severe cases, it may even lead to pneumonia.
History of Water Purification
Water purification dates back as far as the history of water itself. It is difficult to pinpoint who made the first attempt at purifying water. Records of water purification practices were found in ancient Egyptian and Sanskrit writings, dating back to the 3rd century CE.
Hippocrates was the first known person to conduct water purification experiments. Around 500 BC, he made the first bag filter, one that had the purpose of sieving water. This bag received the name of “Hippocratic sleeve,” and had the purpose of trapping sediments that changed the smell and taste of the water.
Water quality began to suffer in the Middle Ages (500-1500 AD), a period also referred to as the Dark Ages. During this time, water treatment did not have a clear future. It began taking shape once more when Sir Francis Bacon started experimenting with desalination in 1627.
The water purification process evolved once more in 1676 when Van Leeuwenhoek began observing microorganisms such as protozoa and bacteria in the water.
In 1700, the first filter for domestic water purification was created. These water filters were made from a mix of sponge, wool, and charcoal. Water filters only improved from that point on, using the same process to create a variety of filter types.
What Is Water Filter and How Does It Work?
A water filter is a membrane that removes impurities from the water. These impurities include sediments, bacteria, and other microorganisms that affect the quality of the water. The resulting purified water will be clean and safe to drink.
Water filtration works in two common ways: physical and chemical filtration. With physical filtration, the larger sediments and particles are captured within the membrane, preventing them from passing through.
Chemical filtration uses patented technology to kill or remove impurities. Often, chemical filtration involves using cleaning resins or activated carbon to remove smaller impurities that physical filtration cannot catch.
Depending on the brand and quality of the filter, water filter efficiency ranges from 46% to 89%. Regardless of the quality, no filter is ever 100% effective. Depending on the type of water filter used, it may take 2-4 hours in order to filter roughly 3 gallons of water.
What Are the Types of Water Filters?
There are five types of water filters in total, each of them having a different application. Each filter addresses a specific problem, and many filters may even use hybrid methods to filter the water. Some filters may have the purpose of removing small sediments, whereas others may be oriented around hidden contaminants.
1. Absorption Filters
Absorption filters are mainly made of carbon. Carbon is very efficient at capturing water-borne pathogens and trapping odor-causing impurities such as chlorine. These absorption filters range from 50 microns, all the way to 0.5 microns. The latter is the most effective option.
2. Mechanical Filters
Mechanical filtration physically removes the large particles from the water. This includes dirt and sediments from 0.5 microns to 5 microns. Mechanical filters may be made from a variety of materials, from mesh to ceramic, with different pore structures to trap the problematic particles.
3. Sequestration Filters
Sequestration filters work by chemically isolating a compound in the water. Polyphosphates are used in the inhibiting filters to capture minerals such as magnesium and calcium, responsible for water corrosion. Sequestration filters have an average pore size of 0.45 microns.
4. Reverse Osmosis Filters
Reverse osmosis filters work by removing the inorganic solids that have dissolved in the water. This includes calcium and magnesium ions. The water is passed through membranes with pore sizes of 0.0001 microns, trapping all particles and contaminants that are above that size. Reverse osmosis filters are usually highly effective at removing viruses, bacteria, and other small contaminants from the water.
5. Ion Exchange Filters
Ion exchange filters are used to turn soft water into hard water. They exchange hard calcium and magnesium ions with other beneficial ions such as hydrogen and sodium. Usually, these filters use ion exchange resin to soften hard water. Ion exchange filters need to be recharged periodically, as the resin may become ineffective after excessive use.
There are different water filtering methods because each method has its own strong side. Very often, different filters are used in combination to increase their efficiency. For example, reverse osmosis filters are used together with mechanical and absorption filters. This way, more harmful particles are filtered out.
Do Water Filters Clean the Water Completely?
No, water filters will not clean the water completely. Depending on their pore size, water filters may catch some contaminants, but allow the smaller ones to pass through. A one-micron water filter will remove particles as small as one micron but will not be able to retain organisms as small as 0.5 microns (i.e., cryptosporidium or giardia). The final result will depend on the filtration capacity of the filter.
What Are Water Purification Tablets?
Water purification tablets are tablets that kill the pathogens residing in the water. By killing the pathogens, the water is made safe for human consumption. Water purification tablets work by adding chlorine, chlorine dioxide, or iodine to the water. This will deactivate viruses, bacteria, and parasites from the water, making them unable to harm the person drinking the water.
Water purification tablets are highly effective in killing the pathogens present in the water. Still, the tablets will only remove the microorganisms, not the sediments. While viruses may be neutralized, they may not work as well with heavy metals and larger particles. In these circumstances, a water filter is required.
For the water to be safely purified, you need to add the right number of tablets to the correct amount of water. Reading the label for instructions is essential. An amount that is too small might not fully purify the water, whereas amounts too big may cause more harm than good.
Is Bottled Water Purified?
Yes, bottled water is purified. In order to meet the standards placed by the FDA, bottled water needs to be free of sediments and tested. It is also safe to assume that not all brands of bottled water are the same, which is why reading the label is essential. If the water has been deemed proper for consumption, the label will say that it has been “filtered.”
Things to consider when buying bottled water include checking the contents of the water. Healthy amounts of sodium, calcium, and magnesium are harmless and even beneficial. Other chemical substances such as fluoride, chlorine, and nitrates should not be part of the ingredients list of bottled water.