The Myth of Pure Water
Water is often marketed as the ultimate symbol of purity. From bottled water companies to luxury brands, purity is a key selling point. But the truth is, pure water as most people imagine it doesn’t actually exist. Water’s unique molecular structure makes it impossible to remain completely pure, as it has a natural tendency to dissolve substances from its surroundings. This characteristic is rooted in the fundamental properties of water molecules themselves.
The Molecular Structure of Water
Water molecules are quite unusual in their shape. Often compared to Mickey Mouse’s face, a water molecule consists of two hydrogen atoms and one oxygen atom. The two hydrogen atoms sit at one end of the molecule, while the oxygen atom resides at the other. These atoms have different electronic charges: hydrogen carries a positive charge, while oxygen holds a partial negative charge. This creates a polar molecule, meaning that water has a slight positive charge on one side and a negative charge on the other.
This polarity gives water molecules a special property known as hydrogen bonding, where the hydrogen atoms of one water molecule are attracted to the oxygen atoms of another. These bonds create a network of molecules that cling to one another, making water cohesive. But this same property also makes water incredibly good at interacting with other substances.
Water's Dissolving Power
Because water molecules are so strongly attracted to each other and to other substances, they don’t remain isolated for long. Water’s polarity allows it to interact with other molecules that carry charges or are polar in nature. Whether it's salts, minerals, or even gases, water will readily dissolve whatever it comes into contact with. This is why water is often called the "universal solvent."
In fact, water's ability to dissolve substances is what makes it essential for life. In the human body, for instance, water dissolves essential nutrients, electrolytes, and gases, allowing them to travel through the bloodstream and into cells. Without this capacity, life as we know it would not exist.
The Pursuit of Purity
When it comes to bottled water, filters, or even distilled water, companies often boast about how pure their product is. They emphasize removing contaminants, minerals, and impurities. However, the purer water becomes, the more aggressive it gets at dissolving substances from its surroundings. As pure water seeks balance, it will start dissolving ions from any container or material it comes into contact with, whether it's the glass of a laboratory beaker or the plastic of a bottle.
This aggressive nature is why true "pure" water is rarely found in nature. Even rainwater, which may seem clean, picks up gases and particles from the atmosphere as it falls. Natural bodies of water like rivers, lakes, and oceans contain minerals, salts, and organic matter that water has dissolved from rocks, soil, and living organisms.
Many bottled water companies offer purified water. These companies use 1 to 10 different mechanical or chemical processes to purify the municipal tap water before bottling. One of the most common processes is RO, reverse osmosis. Industrial reverse osmosis does a great job of removing impurities, minerals and contaminants but we may be less familiar with the repercussions. Industrial RO systems can create a significant amount of waste water. To get 1 gallon of purified water they use 3 to 5 gallons of tap water. The brine or wastewater generated by reverse osmosis systems often contains concentrated levels of contaminants. If not properly handled, the disposal of this wastewater can have negative environmental impacts, particularly in large-scale industrial or desalination operations. With the increase of pure bottled water consumption this impacts our ability to utilize and converse water effectively.
The Role of Ions and Minerals
While some might think of impurities in water as harmful, many of these dissolved substances are actually beneficial. Water with a certain level of mineral content, such as calcium and magnesium, is referred to as "hard water." These minerals contribute to human health by providing essential nutrients. In contrast, water that is too pure—such as distilled water—lacks these beneficial ions and can even have a slightly acidic pH due to dissolved carbon dioxide from the air.
In industrial and scientific applications, ultra-pure water is sometimes necessary. Laboratories use extremely purified water for experiments to avoid contamination, but even in these environments, it’s nearly impossible to keep water completely free from dissolved ions for long.
The quest for pure water is, in a sense, a battle against nature. Water’s molecular structure ensures that it will always interact with its surroundings, dissolving particles, ions, and molecules wherever it goes. While the idea of pure water is appealing, it’s important to recognize that water’s ability to dissolve other substances is one of its most vital properties. Whether in nature or in our bodies, water is meant to carry with it the materials that make life possible. True purity, as much as we might strive for it, remains an illusion.
