FILTERS

How does a water filter work? Wouldn't the water get dirty because of the charcoal? Water filters use a variety of different media (the components of the filter) to reduce contaminants from water. Charcoal is a common media for many water filters. To answer this question simply, a charcoal filter does not make water even dirtier because the charcoal used in water filters is generally solid or granulated (like grains of sand) and not ashy like the charcoal used in art pencils. In a water filter, as water passes over the media, the granules of that media trap large water contaminants and stop them from passing through with the water. The process is very similar to river water passing through rocks and emerging cleaner on the other side. While this method of filtration is certainly useful, it is not perfect. Water filters can only reduce certain contaminants and smaller contaminants will easily pass through the granules of the media with the water. Most modern filters now use chemical processes to filter water, in addition to simple physical filtration. Modern filters use a media that will attract contaminants (using a process of positive and negative charges similar to magnets) and encourage these contaminants to break their bond with water. For example, chlorine is a chemical that often contaminates water. Chlorine is very difficult to remove by simply passing water over a granular media. Chemically, chlorine can be removed by using a carbon-based media to attract atoms of chlorine and to encourage these atoms to break their bond with the water. To sum it all up, water filters reduce contaminants by either physically blocking their passage through the filter media or chemically attracting them to the filter media. In general, they use a granulated or solid filter media that will not travel with water and further dirty it.
Water Treatment Alternatives There is a wealth of water treatment alternatives currently on the market. The proponents of these various water treatment alternatives will often make several promises about their product, and it may become difficult to assess, even for the most conscientious of consumers, the appropriate water treatment product for one’s needs. To aid you in your choice of water treatment, we have provided a brief explanation of three of the most common water treatment alternatives. In the following paragraphs, you can read about the processes and best uses of reverse osmosis, distillation, and filtration. Reverse OsmosisReverse osmosis is a process of water treatment that has risen in popularity since the 1970s. Primarily used as a method of desalinating seawater, the reverse osmosis process involves a semi-permeable membrane—usually constructed from a polyamide-based material—and a source of pressure. Water is forced to move against its natural flow pattern (osmosis) from a solution of high saline concentration to a solution of low saline concentration through the semi-permeable membrane. The object of reverse osmosis is to block the passage of salt particles through the membrane, resulting in a solution of purified water on one side of the membrane and a solution of highly concentrated, salt water on the other side. In recent years, reverse osmosis has been adapted to treat freshwater for drinking water purposes. While reverse osmosis is highly effective at desalinating seawater, there are some aspects to the process that make it undesirable for treating drinking water. First of all, the semi-permeable membrane is only designed to remove particles from water that are physically larger than water molecules. The membrane will remove mineral components and most heavy metals from drinking water, but it will not remove chlorine and other synthetic chemicals. Such chemicals are physically smaller than water molecules and can pass easily through the membrane. Besides this drawback to reverse osmosis, the process is rather wasteful and costly. Generally, three gallons of water are wasted for every one gallon of purified water produced. DistillationThe distillation process--used primarily as a means of producing alcoholic beverages--has existed for millennia. Distillation reached its peak of popularity in the 1970s, but due to its costliness and general inefficiency as a water treatment process, it has now been largely relegated to the purposes of scientific laboratories and printing shops. Still, distillation continues to be used--in small measure--as a method of drinking water purification and merits some discussion. In the distillation process, contaminated water is heated until it reaches its boiling point. Once the water has begun to evaporate, the heat is kept at a constant to ensure that contaminants with a higher boiling point than water do not also evaporate. The steam from the water is led through a series of tubes into a separate container where it is allowed to condense into the liquid form. The object of distillation is to produce pure water in the second container while retaining any contaminants in the first container. Distillation, because of its constant heat source, will remove any contaminants with a higher boiling point than water. Such contaminants include minerals, heavy metals, and many chemicals from pesticide runoff. They do not include chlorine and VOCs, which have a lower boiling point than water. Consequently, distillation is not highly effective at providing safe drinking water. Like reverse osmosis, it is also incredibly inefficient, wasting nearly 80% of the water it uses. FiltrationFiltration has emerged in the last two decades as the forerunner of water treatment technology. Its innovative process is the only purification technique than can effectively remove chlorine—the primary contaminant of municipally treated water. The filtration process utilizes a filter media through which water passes. Such filter media range from sand for older filters and solid block carbon or carbon media mixtures for newer filters. The filtration process generally involves several stages, through which contaminants are removed or reduced in order of importance. In the first stage of filtration, the more concentrated chemicals, like chlorine and VOCs, are significantly reduced. This preliminary reduction allows the remaining stages of filtration to focus on contaminants like pesticides and tiny microbes that are more difficult to filter. The subsequent stages of filtration focus on the reduction of lead and chemicals from pesticide runoff. As the water passes through the stages of filtration, contaminants are both physically and chemically blocked from passage through the filter media. Contaminants that are physically larger than the granules of the media will be blocked from passage while other undesirable elements of drinking water (such as chlorine and VOCs) are encouraged to break their chemical bond with the water molecules and attach to the filter media. One of the primary reasons why filtration has become the forerunning method of water treatment in recent years is its use of both chemical and physical processes to block contaminant passage. Solid block carbon and multimedia filters are not merely the only water treatment products that can remove chlorine and reduce VOCs in drinking water; they are also capable of retaining healthy, pH-balancing minerals in drinking water. The adsorptive process of such filters attracts chlorine and VOCs to the filter media while allowing mineral sediments to pass through the filter.

Drugs, In Our Drinking Water Charles Strand, Water Quality Specialist As if we did not have enough worries already about the quality of our drinking water, we now find that caffeine and many prescription drugs are being detected in our public and private water systems. It is not a very pleasant thought, but, on average, about 10% of the water we drink has been drunk before. The same amount of water that exists on this planet today existed millions of years ago, to the drop! Our planet continuously recycles and re-uses this finite supply of water. Only recently have we learned how fragile and finite our water resources really are. We are now finding traces of compounds in our water that no one ever thought to look for before. In 1999, a 17-year-old West Virginia high school student, Ashley Mulroy, read a report in a science magazine describing how European scientists had recently discovered that “drugs of all kinds, including antibiotics, were flowing in rivers, streams, ground water and even in tap water.” After reading this statement, she decided to embark on a science project of her own. Over a ten-week period, Ashley and her mother drove for miles along the Ohio River, taking samples of the water from different sites. She then returned to her hometown and had the samples tested for three common antibiotics: penicillin, tetracycline and vancomycin. To her surprise, she found traces of all three antibiotics in the samples she had taken. Ashley then sampled tap water in three nearby towns. All three, including water from the drinking fountain at her school, were contaminated with the antibiotics in question. Ashley received several science project awards and, more importantly, opened the eyes of many U.S. scientists. Researchers from the U.S. EPA and the National Geological Survey have now found traces of antibiotics, birth control drugs, anti-depressants, and even caffeine in many water samples taken across the country. Large farming operations and wastewater treatment plants release billions of gallons of contaminated wastewater into our environment each year. Only now, after a high school science project, are experts discussing the potential dangers of trace levels of drugs in our drinking water. USA Today, in an 11/8/00 news release stated, “Experts fear that even low levels of antibiotics fouling the nations water supply may help create super-bugs: micro organisms that have evolved to survive an antibiotic’s lethal assault.” These super-bugs may be causing “tens of thousands” of deaths each year in the U.S.A, according to Abigail Salyers, an expert on antibiotic resistance at the University of Illinois. Christian Daughton, a Chief of Environmental Chemistry for the EPA warns, “Water pollution by drugs is a newly emerging issue.” Our public water treatment plants are not designed to remove drugs and other synthetic chemicals from our water. Without waiting for the final verdict on the actual effects of drinking a mixture of drugs and other chemicals, we can safely assume that they will be negative. The only question is, how negative and why wait? Home water treatment can reduce the risk, conveniently and economically!