Water purification vs Basic filtration
Purified water versus basic filtration: As industrialization progresses, pollution increases, contaminating water sources. The question arises whether outdated basic filtration methods are still sufficient to yield the purest drinking water, or if more potent purification processes are essential to combat modern pollutants. The scales likely favor the latter. Let’s start by examining the traditional filtration methods. These range from boiling to chemical treatments, which, albeit somewhat effective, fall short in eradicating all detrimental substances from water.
Conventional Water Filtration Techniques:
- Boiling: Traditionally, boiling has been the preferred method for disinfecting water from microbes. When done correctly, it can destroy most bacteria, but not all. Bacteria and protozoa are neutralized at boiling point, with an additional three minutes required to eliminate the rest.
Disadvantages of this method:
- High fuel consumption and the necessity of cooking equipment.
- The need for water to cool down before use.
- Evaporation-induced water loss due to high temperatures.
- Residual particulates may remain, requiring further filtering through materials like a handkerchief.
- Boiling fails to remove chemical contaminants such as chlorine and may leave an unpleasant taste.
While suitable for camping, more effective methods are preferable for household use.
- Chemical Treatments: Iodine and chlorine are commonly used for water purification due to their portability, affordability, and ease of use. Iodine is effective against viruses, bacteria, and protozoa, though its effectiveness diminishes in colder water and varies with water clarity. It’s not recommended for pregnant women or those with thyroid issues and is typically used for short-term purposes, not exceeding three consecutive months. Its taste is often unpleasant and can be masked with sweetened beverages, or the method can be altogether avoided.
Chlorine bleach is another chemical purifier. Chlorination aids in sediment settlement, clarifying the water visually. The American Red Cross suggests using unscented bleach with 5.25% sodium hypochlorite. For purification, 16 drops of bleach per gallon are recommended, followed by a 30-minute wait. If there’s no faint bleach odor, the process should be repeated. However, chlorination has its downsides, including the ineffectiveness of old bleach, the risk of over-chlorination leading to illness or organ damage, and associations with various health issues.
The shortcomings of these conventional techniques underscore the need for more advanced water purification systems.
Advanced Modern Water Purification Techniques:
Water filtration entails separating impurities from a water source, with larger particles being simpler to filter. The pore size and durability of the filter element are vital for performance and longevity. Common filter materials include ceramic, glass fiber, solid-block carbon, and materials similar to compressed surgical paper.
Advanced purification methods, such as activated carbon and reverse osmosis, are superior. Activated carbon is adept at reducing chemical content, unpleasant tastes, and odors, but less so against particulates and microorganisms, typically used as a secondary filter. Reverse osmosis uses a semipermeable membrane to separate water from contaminants, effectively removing a wide range of impurities, including total dissolved solids, turbidity, toxic heavy metals, radium, certain organics, chlorine, and even nuclear radiation. Consequently, the combination of reverse osmosis with activated carbon is currently regarded as the most sophisticated water purification method.