- What is Water
- Why is water important to human body
- What are water related diseases & their causes?
- What are common water quality problems?
- What is water filtration?
- What is a membrane?
- What is ADR-Technology?
- What are the benefits of using water filters?
- Why use shower filters
- What are the origins of water hardness?
- What are water softeners?
- What is Ion-Exchange Process?
- Bottled water - Is it really better?
- Chlorine - why should i be concerned?
- Lead- Why should i be concerned?
- Iron & Manganese - removal methods?
Water is a common chemical substance that is essential for the survival of all known forms of life. In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor.
About 1,460 teratonnes (Tt) of water covers 71% of the Earth’s surface, mostly in oceans and other large water bodies, with 1.6% of water below ground in aquifers and 0.001% in the air as vapor, clouds (formed of solid and liquid water particles suspended in air), and precipitation.
Some of the Earth’s water is contained within man-made and natural objects near the Earth’s surface such as water towers, animal and plant bodies, manufactured products, and food stores.
Saltwater oceans hold 97% of surface water, glaciers and polar ice caps 2.4%, and other land surface water such as rivers and lakes 0.6%. Water moves continually through a cycle of evaporation or transpiration (evapotranspiration), precipitation, and runoff, usually reaching the sea. Winds carry water vapor over land at the same rate as runoff into the sea, about 36 Tt per year. Over land, evaporation and transpiration contribute another 71 Tt per year to the precipitation of 107 Tt per year over land. Some water is trapped for varying periods in ice caps, glaciers, aquifers, or in lakes, sometimes providing fresh water for life on land. Clean, fresh water is essential to human and other life. However, in many parts of the world – especially developing countries – it is in short supply. Water is a solvent for a wide variety of chemical substances.
Source:Wikipedia.org
Body Composition
Until recently, most medical theory was based on the assumption that the 20% of our body is solid tissue and that it determines our health, since that is where most outward signs of disease and illness are found. It was thought that the 80% of our body that is liquid merely supported the structure of bone and organ tissue.
We now know the opposite to be true — the fluids that flow through our body are what create our level of well being. The human body is a water machine, designed to run primarily on water and minerals. By weight, our body is about 72% water, another 8% is a combination of chemical compounds and the remaining 20% is bone and solid tissue. From the most basic standpoint it is a common sense equation, if we are made up of 72% plain water, then naturally the quality of the water we consume will have a very dramatic impact on our overall state of health.
Every healing and life giving process that happens in our body happens through water!
Our Blood
Our blood – the very substance of our existence is more than 83% water and flows throughout our body distributing nutrients, oxygen and antibodies on demand where ever needed. In order for our blood to properly carry out its many critical tasks our body must be sufficiently hydrated with “healthy water”. An inadequate intake of water, or consumption of water laced with contaminants, causes the properties of our blood to change and negatively effects virtually every aspect of our health.
Our Brain
Our brain is over 80% water and controls each and every process that happens inside of our body. This control is maintained by constantly sending and receiving electrical signals through our nervous system, which in reality is nothing more than an elaborate system of tiny water ways. The fluid inside our nerves is made up almost completely of water and minerals. Tiny messengers called transporter proteins travel at the speed of light carrying these life giving messages to every cell and organ in our body. Like any communication network the purity of the carrier, our nervous system, effects the speed and clarity of the signal. If the fluid inside of our nerves is laced with traces of chemicals or heavy metals like lead, then the result is a delayed and distorted signal. Many experts now believe that the distortion of these signals may be the root cause of many nervous system disorders like Attention Deficit Disorder, Chronic Fatigue Syndrome, Alzheimer’s Disease, anxiety and depression. It has been well documented that the clarity of these signals has a major effect on our ability to deal with stress and our degree of coordination. Considering the vital role that water plays in our brain and nervous system, its quality is possibly the most basic and essential key to healthful longevity.
Our Energy Level
Our energy level is impacted largely by our consumption of water. It has been medically proven that just a 5% drop in body fluids will cause a 25 to 30% loss of energy in most people. It is also estimated that more than 2/3 of all people do not drink enough water and suffer some degree of dehydration.
The result being a large part of our population operating at only 70 to 75% of their capacity, or less. Unfortunately most people turn to stimulants like caffeine and sugar to boost their energy level rather than drinking more water, which is what our body needs to produce natural energy. Caffeine, alcohol and sugar are all strong diuretics and actually cause your body to lose water, resulting in a further loss of natural energy production and eventually can lead to a dependency on artificial energy.
What are water related diseases & their causes?
Disease | Causative organisms |
Mode of Spread | Symptoms |
BACTERIA | |||
Typhoid | Salmonella typhi | Ingestion of contaminated food, water, milk, unwashed raw vegetables and flies | Continuous fever which progressively increases day by day, the temperature being higher in the evening than in the morning accompanied by body aches, headache and constipation, Hemorrhage from an ulceration in the small intestine |
Cholera | Vibrio cholerae | Ingestion of water or food contaminated by the bacteria from the stool of a cholera patient | Painless diarrhea followed by vomiting; patient may pass 30 to 40 stools per day which soon becomes typically watery and colourless with flakes of mucous floating in them |
Bacterial dysentery |
Shigella spp. | Through contaminated food, water and by direct personal contact | Diarrhea, with the presence of blood and mucous in the stools accompanied by severe gripping pain in the abdomen. Stools are not too frequent (4-10 per day) and the fecal matter is scanty. Patient looks ill. |
Leptospirosis | Leptospira | Primary hosts are rodents, which carry the organisms in their kidneys and the patient may become infected by wading or swimming in water contaminated with the rodent’s urine | Fever, pain in legs, nausea, vomiting are common, congestion of the conjunctival blood vessels around the corneas of the eyes |
VIRUSES | |||
Infective hepatitis | Hepatitis virus | Stools that contain virus contaminating the water and food | Loss of appetite, nausea, vomiting and diarrhea accompanied by fever. The urine is dark coloured. Eye and skin have yellow coloration |
PROTOZOA | |||
Amoebic dysentery | Entamoeba histolytica | Ingestion of cysts in food and water | Abdominal discomfort to diarrhea, with or without the presence of blood or mucus in the stools, accompanied by fever, chills and gripping pain in the abdomen |
Diarrhea | Giardia(=Lamblia) intestinalis | Cysts which are voided with the feces and enter the new hosts in food or water | Intestinal disorders leading to epigastric pain, abdominal discomfort, loss of appetite, headache and loose bowels |
HELMINTHS | |||
Bilharzia | Schistosoma spp. | Eggs of the flukes pass out with human feces or urine and if they reach fresh water, develop into miracidia larvae which infect snails. The cercaria stage develops in the snails and on leaving the host, cercaria penetrate the skin of humans wading in the water. | Allergy-like itch, rash, aches, fever, eosinophilia, etc. When infection is heavy, the eggs may be deposited in the arterioles of the lungs causing cardio-pulmonary schistosomiasis or corpulmonale or ayerza disease, which may lead to congestive heart failure |
Guinea worm | Dracunculus medinensis | Unfiltered water containing the infected copepods | Blister near the ankle, burns around the blister, allergy and aches |
Protection against water-borne diseases
It is necessary to be careful about the water you drink and the water you bathe in, since water is a carrier for a number of diseases. Drinking water
Bathing Water Avoid
Safe water supply Sanitation barrier Health education |
Common Aesthetic Problems and Solutions
Symptom | Probable Cause | Treatments |
Hard water deposits on kettles, pots, hot water heaters, humidifiers | Excess calcium | Water softener Reverse Osmosis Anti-Scale Units Distillation |
Rusty red or brown staining of fixtures or laundry and/or your water has a metallic taste | Excess iron | Water softener Whole house iron filter Distillation |
Black staining of fixtures or laundry | Excess manganese | Water softener Whole house iron filter Distillation |
Rotten egg smell | Hydrogen sulfide | Manganese Greensand filter |
Water has laxative effect | Excess sulfates | Reverse Osmosis Distillation |
Water is gritty, muddy, or appears dirty | Excess sand, dirt, or other sediments in your water | Whole House Sediment Filter Any point-of-use filter system with a sediment filter |
Aesthetics
Otherwise harmless contaminants like chlorine, sulfur, iron, and manganese that cause taste, color, and odor problems.
Water Hardness
Hard water contains excessive levels of the minerals calcium and magnesium, a condition found in 85 percent of the United States. Hard water shortens the life of household plumbing and water-using appliances, makes cleaning and laundering tasks more difficult and gradually decreases the efficiency of water heaters.
Lead
Used extensively in plumbing materials (pipes and lead-based solder) until the late 1980’s, lead can leach into water supplies. Low levels of lead have been linked to learning disabilities in young children, and high levels can cause hypertension in adults.
Biological Pathogens
Waterborne organisms that can cause disease in humans. They include cysts like Cryptosporidium and Giardia; bacteria like typhus, fecal coliform and cholera; and viruses like influenza. These organisms typically cause unpleasant intestinal disorders and can pose a significant threat to the immune-impaired.
Nitrates
Nitrogen compounds are sometimes found in ground and surface water in rural areas, often as a result of nitrogen-based fertilizer runoff. Excess nitrate levels can interfere with the oxygen-carrying capacity of blood, especially in babies, and have been linked to high incidences of miscarriages.
Heavy Metals
Metals like mercury, zinc, copper, and cadmium usually enter the water supply as industrial waste and, in excessive concentrations, can cause physiological damage to humans, including damage to the central nervous system.
Radium/Radon
Naturally occurring radioactive elements linked to cancer in humans. Radon is found in gaseous form, and is absorbed through drinking, as well as through inhalation during washing or showering.
VOC’s
Volatile organic compounds, such as the petroleum distillate benzene and the industrial degreasing compound trichloroethylene. High concentrations of VOC’s are linked to organ damage and cancer in humans.
THM’s
Trihalomethanes are by-products produced when chlorine reacts with organic compounds in water. THM’s are primarily absorbed through inhalation, and have been linked to bladder and rectal cancer.
Asbestos
A fibrous mineral that contaminates water naturally or through its past use in concrete water pipes. Asbestos has been linked to lung and other forms of cancer.
Arsenic
Both a natural and manufacturing-induced ground water contaminant, arsenic is linked to various cancers and may damage the circulatory and central nervous systems.
Sediments
Solid particulates in water that can settle out over time. The presence of sediments in water is typically an aesthetic concern.
Low/High pH
pH refers to “potential hydrogen,” and is a measure of acidity or alkalinity on a 14-point scale (zero through six is acidic; seven is neutral; and eight through 14 are alkaline). Extreme measures of acidity in water can be corrosive, whereas high alkalinity can be the source of aesthetic problems.
Water filters have a long history as a method of water purification, beginning as early as 2000 b.c.e. in ancient Egypt. Filtration has evolved from the simple Hippocratic sleeve of ancient Greece, made from cloth, to the complicated solid block carbon and multimedia water filters currently on the market. Water filtration is now the premier method of water purification, removing more water contaminants, more efficiently, than any other technique.
The Process
The filtration process involves some type of filter media, over which water flows. This filter media blocks passage of contaminants through physical obstruction, chemical adsorption, or a combination of both processes. Material construction of the filter media varies widely, but the most effective medias are made from carbon or a combination of carbon with other elements.
Modern filtration technology allows water filters to remove more and more contaminants through the chemical process of adsorption. In the adsorption process, contaminants are encouraged to break their bond with water molecules and chemically adhere to the filter media. Generally, water goes through several stages of filtration to ensure that each filter media will remove the ultimate number of contaminants.
Water normally passes through a water filter at a relatively low speed, in order to ensure adequate contact time with the filter media. Once the water has passed through the required stages of filtration, it emerges as pure drinking water, free from contamination.
Treatment Techniques and Devices
Once contamination is detected in a drinking water supply it is important to use the proper treatment device to remove the contaminant. The following section is intended as a guide to help in the selection of a treatment device. Before buying a treatment device have the water supply tested for contamination and consult a specialist when selecting the best treatment device. If the specific contaminant is known the information in the following sections will indicate the possible treatment devices and link to more detailed information on this web site.
ACTIVATED ALUMINA
Activated Alumina is a granulated form of aluminium oxide. In this process, water containing the contaminant is passed through a cartridge or canister of activated alumina. The alumina absorbs the contaminant and freshwater continues to the service faucet. The cartridge of activated alumina has to be replaced periodically. It is important to determine by testing when the contaminant removal capability of the device is exhausted, so the treatment technique will remove, not contribute to, the contaminant. Also, activated alumina devices will accumulate bacteria, so treated water will have higher bacteria counts than raw water.
Contaminants Removed: Arsenic, Fluoride.
ACTIVATED CARBON
Activated carbon filters absorb impurities from water as it passes through a carbon cartridge or tank. Such filters are used to eliminate or remove undesirable odors, tastes, organic compounds, and residual chlorine. Carbon filters also remove some potentially, hazardous contaminants such as radon gas, hydrogen sulfide, many dissolved organic chemicals and trihalomethanes. Most inorganic chemicals are not removed by these filters.
Contaminants Removed: Hydrogen Sulfide, Radon, Chlorine, Volatile Organic Compounds, Pesticides, Benzene, Colors, Odors.
Related Items: Whole House Carbon Filters
AERATION
Aeration systems spray the water through an air-filled chamber then use a fan to move the contaminated air out of the area.
Contaminants Removed: Hydrogen Sulfide, Radon.
ANION EXCHANGE
Anion exchange units use a resin that exchanges chloride, or in some cases hydroxide, for the contaminant anions. Most use chloride which increases the chloride content of water as it removes anions such as nitrate, sulfates and bicarbonates.
Contaminants Removed: Nitrate, Sulfate, Fluoride, Tannins.
Related Items: Nitrate Filters, Tannin Filters
CHEMICAL PRECIPITATION
In chemical precipitation certain compounds are added to the water that chemically react with the contaminate. The products of the reaction will then either sink to the bottom or float to the top of the holding tank, so that they can be removed. This method is primary used in public water supplies and is not a viable solution for private water supplies. If contaminant is detected in a private water supply use an alternate method or contact you local water authority.
Contaminants Removed: Arsenic, Barium, Cadmium, Chromium, Lead, Mercury, Selenium, Silver.
CHLORINATION
The most common, oldest and relatively inexpensive method used to disinfect water is chlorination. A chemical feed pump continuously dispenses chlorine into the water supply. Chlorine, an oxidizing agent, kills most bacteria and some viruses. In the proper concentrations and under adequate exposure time, chlorine is an excellent disinfectant.
Chlorine reacts with certain metals and organic matter in the water to form hazardous, chlorinated, organic chemicals. Use of an activated carbon filter after chlorination will remove excess chlorine and limited amounts of any chlorine compounds formed. Chlorination may also oxidize and remove some color and odor causing substances, including iron and hydrogen sulfide.
Contaminants Removed: Bacteria, Iron, Hydrogen Sulfide, Some Viruses.
Related Items: Chlorinators
DISTILLATION
Distillation heats water until it vaporizes as steam. Minerals, bacteria and other substances are left behind when the steam recondenses into relatively pure water. Distillers remove bacteria, minerals, trace amounts of metals, many volatile organic chemicals and nitrate. The distillation process is very slow (daily capacity is usually between two and five gallons). Approximately five gallons of tap water is required to produce one gallon of distilled water.
Contaminants Removed: Bacteria, Lead, Nitrate, Sodium Chloride, Organic Chemicals, Many Pesticides.
Related Items: Distillers
ION EXCHANGE
Ion exchange systems soften hard water by removing the minerals (calcium and magnesium that cause hardness. This system also efficiently removes iron, manganese and many heavy metals. The hard water is pumped through a tank containing an exchange resin. Sodium on the resin replaces the hardness minerals. The sodium remains in a soluble form in the softened water.
Contaminants Removed: Iron, Magnesium, Calcium, Manganese.
Related Items: Water Softeners
MECHANICAL FILTRATION
Mechanical filters, or microfiltration, removes suspended material from water including sand, silt, clay or organic matter. These filters do not remove dissolved or very fine particles and are often used in combination with other treatment equipment. Filters are commonly of fabric, fiber, ceramic or other screening material.
Contaminants Removed: Sediment
Related Items: Whole House Sediment Filters
NEUTRALIZING FILTERS
Neutralizing filters treat acidic water. The filter treats all of the home water supply by passing it through granular calcite (marble, calcium carbonate or lime) or by chemically feeding in soda ash, sodium carbonate or caustic soda (sodium hydroxide).
Contaminants Removed: Acidity.
Related Items: pH Neutralizing Filters
OXIDIZING FILTERS
Oxidizing filters use a zeolite coated filter to oxidize dissolved iron, manganese and hydrogen sulfide. The contaminants then form large particles that the filter can catch.
Contaminants Removed: Hydrogen Sulfide, Iron, Manganese.
Related Items: Manganese Greensand Filters, Birm Filters
REVERSE OSMOSIS
Reverse Osmosis (RO) units remove substantial amounts of most inorganic chemicals (such as salts, metals, minerals) most microorganisms, and many organic chemicals. They do not effectively remove some organic compounds. Mechanical filters and activated carbon filters are almost always used with a RO unit. First, the mechanical filter (1) removes dirt, sediment and other impurities, that would otherwise clog the reverse osmosis membrane. The RO (2) unit is installed next. The water is held in a pressurized water storage container (3). An activated carbon filter (4) then removes organic compounds which pass though the RO unit. A separate water tap (5) is used for this water.
Reverse Osmosis uses large amounts of water. Typically, about 75% or more of the water is discarded with the contaminants.
Contaminants Removed: Lead, Sulfate, Calcium, Magnesium, Sodium, Potassium, Manganese, Aluminum, Chloride, Nitrate, Fluoride Boron, Most Microorganisms, Organic Chemicals.
Related Items: Reverse Osmosis Filters
ULTRAVIOLET
Low-pressure mercury arc lamps produce ultraviolet light which has germicidal properties. The radiation kills or deactivates pathogens. Bacteria are killed with relatively low amounts of radiation, viruses are more resistant, and cysts and worms are unaffected. Radiation leaves no residual product that continues to disinfect beyond the treatment period.
Contaminants Removed: Bacteria, Viruses, Cysts such as Cryptosporidium and Giardia.
Related Items: Ultraviolet Filters
Common Aesthetic Problems and Solutions
Symptom | Probable Cause | Treatments |
Hard water deposits on kettles, pots, hot water heaters, humidifiers | Excess calcium | Water softener Reverse Osmosis Anti-Scale Units Distillation |
Rusty red or brown staining of fixtures or laundry and/or your water has a metallic taste | Excess iron | Water softener Whole house iron filter Distillation |
Black staining of fixtures or laundry | Excess manganese | Water softener Whole house iron filter Distillation |
Rotten egg smell | Hydrogen sulfide | Manganese Greensand filter |
Water has laxative effect | Excess sulfates | Reverse Osmosis Distillation |
Water is gritty, muddy, or appears dirty | Excess sand, dirt, or other sediments in your water | Whole House Sediment Filter Any point-of-use filter system with a sediment filter |
Membranes are thin films of porous material which can be used for a number of chemical separations. Although many membranes are made from polymer films, membranes can be formed from ceramics, carbon fiber, and porous metal substrates. The pores can range from atomic dimensions (< 10 angstroms) to 100+ microns.
How are membranes used?
The small pores of the membranes can serve as a physical barrier, preventing passage of certain materials such as salt, bacteria and viruses while allowing the free passage of water and air. The desalination of water using reverse osmosis is a well known use of membranes as a filter.
Recently, recovery of water from sewage and recovery of whey protein from waste streams during cheese making have been carried out with ultrafiltration and microfiltation membranes which require much less pressure than reverse osmosis. While pressure is used to drive filtration, electrical current, osmotic pressure, and temperature can also be used to preferentially allow one component in a mixture to pass freely through the membrane while retaining the rest. The membrane structure and chemistry can also serve to carry out other separations.
Membranes provide a high surface area material where chemical reactions or diffusion can take place. For example, bundles of hollow fiber membranes (membranes in a thin tubular form) are used in dialysis to purify the blood by removing certain toxins. Membranes can also be used to carry out solvent extraction and catalysis while also serving to separate the reactants.
Hydrophobic membranes can be used to prevent passage of liquid water but allow vapor to pass (like Goretex). This property has been exploited in membrane distillation where brackish water is heated using solar power and the pure water vapor passes through the membrane and condensed to produce very high quality water. This uses less energy than boiling and utilizes bountiful but low value energy in remote areas.
ADR-Technology™ stands for Advanced Dielectric Resonance Technology and consists of a special preparation process of dielectric ceramic material using a classical ceramic as a basis. Applying the optimum conditions of this synthesis results in a ceramic material with a defined microstructure and specific dielectric characteristics in a frequency range of 5 -10 MHz.
ADR-Technology™ restores physical properties of water, which initiate changes in the human body and improve enzymatic and metabolic processes on molecular level. Water becomes highly reactive due to its lower surface tension (without use of chemical substances) and increased relaxation time of water molecules.
As a result of these changes, human body is able to absorb and dissolve minerals and nutrients carried by the water at much higher and more efficient rates and thus, increase and balance energy level of individual organs and entire systems. In addition, ADR-Technology™ has been proven to significantly increase of scavenging free radicals in tea made with water process by Shopure® ECO or Shopure® PLUS filtration system or modules which consist of ADR-Technology™ component.
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aquafilter water filters offer the last line of defense between the body and the over 2100 known toxins that may be present in drinking water.
Chlorine in drinking and general use water is the cause of major health problems. You should install a shower filter for the following reasons:
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When the body is able to retain its natural moisturizers, the need for costly lotions and moisturizers is greatly reduced.
Every household and every factory uses water. One class of impurity that is of special interest is “hardness”. This refers to the presence of dissolved ions, mainly of calcium Ca2+ and magnesium Mg2+ which are acquired through contact with rocks and sediments in the environment.
The positive electrical charges of these ions are balanced by the presence of anions (negative ions), of which bicarbonate HCO3- and carbonate CO32- are most important. These ions have their origins in limestone sediments and also from carbon dioxide which is present in all waters exposed to the atmosphere and especially in groundwaters.
Carbon dioxide reacts with water to form:
(1) carbonic acid – which at ordinary environmental pH exists mostly as bicarbonate ion (2). Microscopic marine organisms take this up as carbonate (4) to form calcite skeletons which, over millions of years, have built up extensive limestone deposits. Groundwaters, made slightly acidic by CO2 (both that absorbed from the air and from the respiration of soil bacteria) dissolve the limestone (3), thereby acquiring calcium and bicarbonate ions and becoming “hard”. If the HCO3- concentration is sufficiently great, the combination of processes (2) and (4) causes calcium carbonate (“lime scale”) to precipitate out on surfaces such as the insides of pipes. (Calcium bicarbonate itself does not form a solid, but always precipitates as CaCO3.)
Water softeners – why do you need them?
It’s easy to forget how important water is in our lives. Of course we need it in our diet, but in our homes, it’s a tool–a fluid medium that carries material from one place to the next. And one of the reasons it does this job well is that it’s very good at holding things, either by suspending them or dissolving them.
Unlike most tools, though, water doesn’t come with an instruction manual. If it did, you’d know why the dishes you thought were washed are covered with spots when dry, why the water in your shower leaves a film on everything it touches, and why what you thought was clean water has clogged up your plumbing system.
Water passing through the mineral tank loses positively charged calcium and magnesium ions to negatively charged plastic beads. The brine tank holds a salt solution that flushes the mineral tank, replacing calcium and magnesium ions with sodium. A meter at the top of the mineral tank regulates recharging cycles. The valve assembly routes water flow for each phase of the regeneration cycle |
Causes and Effects
While water is in the ground, it picks up soluble bits of whatever it passes through. While this can mean contamination that makes the water unfit to drink, in many cases it simply means that the water contains minerals found in the earth. Of these, calcium and magnesium are of particular importance because they affect the water’s ability to function in our homes. These minerals make our water hard.
One effect of hard water is that soaps and detergents lose some effectiveness. Instead of dissolving completely, soap combines with the minerals to form a coagulated soap curd. Because less soap is dissolved, more is required. And the sticky insoluble curd hangs around–it clings to the skin and may actually inhibit cleansing. Washed hair seems dull and lifeless.
In the laundry, things aren’t much better. The soap curd can work its way into your clothes as they’re being washed in your automatic washing machine. This can keep dirt trapped in the fibers, and it can stiffen and roughen the fabric.
In addition to affecting the actual washing process, insoluble soap deposits leave spots on everything you wash–from your dishes to the family car–and a soap film will build up in your bath and shower.
Another reason to be concerned about hard water is its effect on your plumbing system. Calcium and magnesium deposits can build up in pipes, reducing flow to taps and appliances. In water heaters, these minerals generate a scale buildup that reduces the efficiency and life of the heater.
The Solution – Water Softeners
The solution to the problem is to get rid of the calcium and magnesium. While there are chemical treatments that do this, the most popular answer is a water softener.
The typical water softener is a mechanical appliance that’s plumbed into your home’s water supply system. All water softeners use the same operating principle: They trade the minerals for something else, in most cases sodium. The process is called ion exchange.
The heart of a water softener is a mineral tank. It’s filled with small polystyrene beads, also known as resin or zeolite. The beads carry a negative charge.
Calcium and magnesium in water both carry positive charges. This means that these minerals will cling to the beads as the hard water passes through the mineral tank. Sodium ions also have positive charges, albeit not as strong as the charge on the calcium and magnesium. When a very strong brine solution is flushed through a tank that has beads already saturated with calcium and magnesium, the sheer volume of the sodium ions is enough to drive the calcium and magnesium ions off the beads. Water softeners have a separate brine tank that uses common salt to create this brine solution.
In normal operation, hard water moves into the mineral tank and the calcium and magnesium ions move to the beads, replacing sodium ions. The sodium ions go into the water. Once the beads are saturated with calcium and magnesium, the unit enters a 3-phase regenerating cycle. First, the backwash phase reverses water flow to flush dirt out of the tank. In the recharge phase, the concentrated sodium-rich salt solution is carried from the brine tank through the mineral tank. The sodium collects on the beads, replacing the calcium and magnesium, which go down the drain. Once this phase is over, the mineral tank is flushed of excess brine and the brine tank is refilled.
1. The backwash phase removes dirt from the mineral tank. 2. Recharging the mineral tank with sodium from the brine solution displaces calcium and magnesium, which is then washed down the drain. 3. The final phase rinses the mineral tank with fresh water and loads the brine tank so it’s ready for the next cycle.
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Automatic Regeneration Control
Most popular water softeners have an automatic regenerating system. The most basic type has an electric timer that flushes and recharges the system on a regular schedule. During recharging, soft water is not available.
A second type of control uses a computer that watches how much water is used. When enough water has passed through the mineral tank to have depleted the beads of sodium, the computer triggers regeneration. These softeners often have reserve resin capacity, so that some soft water will be available during recharging.
A third type of control uses a mechanical water meter to measure water usage and initiate recharging. The advantage of this system is that no electrical components are required and the mineral tank is only recharged when necessary. When it is equipped with two mineral tanks, softened water is always available, even when the unit is recharging.
The Process of Ion-exchange
In the context of water purification, ion-exchange is a rapid and reversible process in which impurity ions present in the water are replaced by ions released by an ion-exchange resin. The impurity ions are taken up by the resin, which must be periodically regenerated to restore it to the original ionic form. (An ion is an atom or group of atoms with an electric charge. Positively-charged ions are called cations and are usually metals; negatively-charged ions are called anions and are usually non-metals).
The following ions are widely found in raw waters:
Cations | Anions |
Calcium (Ca2+) | Chloride (Cl–) |
Magnesium (Mg2+) | Bicarbonate (HCO3–) |
Magnesium (Mg2+) | Nitrate (NO3–) |
Sodium (Na+) | Carbonate (CO32-) |
Iron (Fe2+) | Sulfate (SO42-) |
Ion Exchange Resins
There are two basic types of resin – cation-exchange and anion-exchange resins. Cation exchange resins will release Hydrogen (H+) ions or other positively charged ions in exchange for impurity cations present in the water. Anion exchange resins will release hydroxyl (OH–) ions or other negatively charged ions in exchange for impurity anions present in the water.
Today’s modern ion-exchange resins are prepared from synthetic polymers such as styrenedivinylbenzene copolymers which have either been sulphonated to form strongly acidic cation-exchangers or aminated to form strongly basic or weakly basic anion-exchangers.
The application of ion-exchange to water treatment and purification
These are three ways in which ion-exchange technology can be used in water treatment and purification: first, cation-exchange resins alone can be employed to soften water by base exchange; secondly, anion-exchange resins alone can be used for organic scavenging or nitrate removal; and thirdly, combinations of cation-exchange and anion-exchange resins can be used to remove virtually all the ionic impurities present in the feedwater, a process known as deionization.
The first two technologies are forms of water treatment in which either the chemical nature of the impurities is changed (as in base-exchange softening) or certain impurities are selectively removed (as in organic scavenging or nitrate removal). By contrast, deionization is a purification process which can produce water of exceptionally high quality.
Base-Exchange Softening
Softening was the first industrial application involving ion exchange. The process was first proposed by Gans in 1905. Except for certain improvements in the type of ion exchange material and the equipment, Gans’ process is still one of the simplest methods for softening water.
The process involves passing water containing hardness ions, namely calcium (Ca2+) and magnesium (Mg2+) through a column containing a strongly acidic cation exchange resin in the sodium (Na+) form (i.e. the exchangeable cations are sodium). The calcium and magnesium ions are exchanged for an equivalent number of sodium ions. The resin, once exhausted, (i.e. all the available sodium ions have been exchanged) must be re-charged. This entails passing a solution containing a high concentration of sodium salts such as brine (sodium chloride) through the ion exchange resin – a process known as regeneration.
Main Usages of Softened Water
- To prevent scale formation in boilers, water heaters, steam irons and dish-washing machines etc.
- To eliminate the production of insoluble ‘scums’ formed as a result of the reaction between calcium and magnesium ions with fatty acids found in soaps – in the textile industry, washing machines etc.
- To prevent unsightly stains on glassware, mirrors, etc.
- To pre-treat reverse osmosis feed water to prevent fouling of reverse osmosis membranes.
Organic Scavenging
Organic scavengers are fully automatic plants designed primarily to remove naturally-occurring organic contaminants – mainly humic and fulvic acids – from water supplies. These are weakly-ionised compounds which can irreversibly foul normal anion resins and reverse osmosis membranes, but which can readily be removed from water by a combination of adsorption and ion-exchange.
Organic scavengers contain special macroporous anion-exchange resins operated in the chloride form. They have an open structure with large pores that allow the bulky organic anions to be removed from the feedwater and then eluted out again during regeneration.
Regeneration is initiated automatically by a clock cycle timer. The regenerant is sodium chloride in the form of a 10% brine solution which is drawn into the scavenger from a brine tank.
Nitrate Removal
Nitrates are a particular hazard to infants under six months old. The nitrates are reduced to nitrites in the child’s gastro-intestinal system, reducing the capacity of the blood to carry oxygen (‘blue baby syndrome’). The simplest and most cost-effective method of removing nitrates from water is by anion-exchange, using resins operated in the chloride form and regenerated with brine. Special resins are available to treat sulphate-rich waters. (Conventional resins have a stronger affinity for sulphate than nitrate, reducing their capacity for nitrate removal).
Deionization
For many laboratory and industrial applications, high-purity water which is essentially free from ionic contaminants is required. Water of this quality can be produced by deionization.
The two most common types of deionization are:
- Two-bed deionization
- Mixed-bed deionization
Two-bed deionization
The two-bed deionizer consists of two vessels – one containing a cation-exchange resin in the hydrogen (H+) form and the other containing an anion resin in the hydroxyl (OH–) form. Water flows through the cation column, whereupon all the cations are exchanged for hydrogen ions.
To keep the water electrically balanced, for every monovalent cation, e.g. Na+, one hydrogen ion is exchanged and for every divalent cation, e.g. Ca2+, or Mg2+, two hydrogen ions are exchanged. The same principle applies when considering anion-exchange.
The decationised water then flows through the anion column. This time, all the negatively charged ions are exchanged for hydroxide ions which then combine with the hydrogen ions to form water (H2O).
Mixed-bed deionization
In mixed-bed deionizers the cation-exchange and anion-exchange resins are intimately mixed and contained in a single pressure vessel. The thorough mixture of cation-exchangers and anion-exchangers in a single column makes a mixed-bed deionizer equivalent to a lengthy series of two-bed plants. As a result, the water quality obtained from a mixed-bed deionizer is appreciably higher than that produced by a two-bed plant.
The vessel can be in the form of a large stainless steel or reinforced fibreglass column containing many hundreds of litres of resin, or a small disposable/regenerable cartridge which, when exhausted, can either be thrown away or sent back to the original supplier for regeneration. The large deionizers – whether two-bed or mixed-bed – regenerate themselves automatically, in situ, when the water quality drops to a pre-set level.
Although more efficient in purifying the incoming feedwater, mixed-bed plants are more sensitive to impurities in the water supply and involve a more complicated regeneration process. Mixed-bed deionizers are normally used to ‘polish’ the water to higher levels of purity after it has been initially treated by either a two-bed deionizer or a reverse osmosis unit.
The deionizers used in laboratory applications are almost invariably small mixed-bed units containing exchangeable or disposable cartridges of resin. Large, self-generating deionizers are sometimes used in water purification systems supplying substantial volumes of water to suites of laboratories, or providing large quantities of industrial process water.
Bottled water – The reality…
According to the National Water Quality Association, 56% of all people are worried about the quality of municipally treated tap water. This, along with the desire for better tasting drinking water, has fueled tremendous growth in the bottled water industry. But is bottled water really better than tap water?…
The Industry
The bottled water industry has become the target of some of the largest corporations in the world. Clorox Bleach Co., Pepsi Cola and Coca Cola are just a few of the recent entrees capitalizing on this highly lucrative market, with Clorox being the biggest participant in the bottled water business.
Millions and millions of dollars are spent each week on advertising campaigns to give the perception that these bottled waters come from some pristine mountain spring, when in reality many of them come from a municipal water system just like your tap water does. Both Pepsi’s Aquafina and Coke’s Dasani are bottled at one of many bottling plants across America where municipal water is used as the source, as is the case with many leading brands.
Regulation
The regulations that govern bottled water only require it to be “as good as” tap water. There are no assurances or requirements for bottled water to be of any higher quality than tap water, and according to some recent studies, it may often be of lower quality.
Only water that is transported across a state line is required to meet federal standards. Bottled water companies have used this loop hole to avoid complying with basic health standards, such as those that apply to municipally treated tap water. Also, all carbonated or sparkling waters are completely exempt from FDA guidelines that set specific contamination limits.
According to the NRDC (National Resources Defense Council) study, “even when bottled waters are covered by FDA’s specific bottled water standards, those rules are weaker in many ways than EPA rules that apply to big city tap water.” For instance, if we compare EPA regulations for tap water to FDA’s bottled water rules: (these examples are quotes from the NRDC’s official report)
- City tap water can have no confirmed E.coli or fecal coliform bacteria. FDA bottled water rules include no such prohibition (a certain amount of any type of coliform bacteria is allowed in bottled water).
- City tap water, from surface water, must be filtered and disinfected. In contrast, there are no federal filtration or disinfection requirements for bottled water.
- Most cities using surface water have had to test for Cryptosporidium or Giardia, two common water pathogens, that can cause diarrhea and other intestinal problems, yet bottled water companies do not have to do this.
- City tap water must meet standards for certain important toxic or cancer-causing chemicals, such as phthalate (a chemical that can leach from plastic, including plastic bottles); some in the industry persuaded FDA to exempt bottled water from the regulations regarding these chemicals.
- City water systems must issue annual “right to know” reports, telling consumers what is in their water. Bottlers successfully killed a “right to know” requirement for bottled water.
The Natural Resources Defense Council report concluded that “Therefore, while much tap water is indeed risky, having compared available data, we conclude that there is no assurance that bottled water is any safer than tap water.” (The NRDC report on bottled water can be found at NRDC.Org)
So what to do?
The reality of bottled water is that people pay from $1 to $4 a gallon for the perception of higher quality, when in fact, the quality of bottled water is at best “unknown”! We have no way of knowing the actual quality of bottled water. Point-of-Use water treatment, with a quality in home water filtration system, is by far the most economical, the most convenient and the most capable of producing the highest quality, healthy water.
Removing the chlorine and other contaminants at the point of use, just prior to consumption, in your own home, with a system that is documented to produce “healthy water”… just makes more sense. With a home water filter you can have guaranteed quality for about .10 a gallon vs. $1 to $4 a gallon for bottled. Like the saying say… “If you want something done right, you have to do it yourself”, and that’s certainly the case when it comes to something as important as our drinking water”.
Major Concerns
Simply stated chlorine is a pesticide, as defined by the U.S. EPA (Environmental Protection Agency), which sole purpose is to kill living organisms. When we consume water containing chlorine, it destoys cells and tissues inside our body. Breast cancer, which now effects one in every eight women in North America, has recently been linked to the accumulation of chlorine compounds in the breast tissue. A study carried out in Hartford Connecticut found that, “women with breast cancer have 50% to 60% higher levels of organochlorines (chlorination byproducts) in their breast tissue than women without breast cancer.“
Inhalation vs. Drinking
One of the most shocking components to all studies is that up to 2/3s of our harmful exposure to chlorine is due toinhalation of steam and skin absorption while showering. A warm shower opens up the pores of the skin and allows for accelerated absorption of chlorine and other chemicals in water. The steam we inhale while showering can contain up to 50 times the level of chemicals than tap water due to the fact that chlorine and most other contaminants vaporize much faster and at a lower temperature than water. Inhalation is a much more harmful means of exposure since the chlorine gas (chloroform) we inhale goes directly into our blood stream.
When we drink contaminated water the toxins are partially filtered out by our kidneys and digestive system. Chlorine vapors are known to be a strong irritant to the sensitive tissue and bronchial passages inside our lungs, it was used as a chemical weapon in World War II. The inhalation of chlorine is a suspected cause of asthma and bronchitis, especially in children.
Bad Taste & Smell
Aside from all the health risks related to chlorine in our water, it is the primary cause of bad taste and odor in drinking water. The objectionable taste causes many people to turn to other less healthful beverages like soft drinks, tea or other sweetened drinks. A decreased intake of water, for any reason, can only result in a lower degree of health.
The good news is that chlorine is one of the easiest substances to remove from our water. For that reason it logically should serve it’s purpose of keeping our water free from harmful bacteria and water borne diseases right up to the time of consumption, where it should then be removed by quality home filtration.
Lead in Water
Next to chlorine, lead is the most common contaminant found in tap water. Lead in drinking water usually originates between the water main in the street and the household faucet, so point-of-use treatment is the most logical or practical means of filtering this contaminant. Most lead in drinking water comes from lead lined pipes, lead solder and brass plumbing fixtures inside your home. The Environmental Protection Agency (EPA) estimates that 98% of all homes have pipes, fixtures or solder joints in the household plumbing that can contribute some level of lead to the tap water.
Health Risks
It has been determined and recognized by the EPA that there is no safe level for lead in drinking water and that any level poses some degree of adverse health effects. Lead takes it’s greatest toll on small children. Even very low levels of lead can cause reduced IQs, learning disabilities and behavioral problems such as hypertension and reduced attention span in children. And often the effects of lead are life long and irreversible.
In adults lead in drinking water causes high blood pressure and reduces hemoglobin production necessary for oxygen transport and interferes with normal cellular calcium metabolism. Water borne lead effects every one in a permanent way. Lead exposure is cumulative and long lasting.
This toxic metal is stored by the body, primarily in teeth and bones. When the body is under physical stress, or deficient in certain minerals, the stored lead is released in varying quantities depending on the individuals physical state. Essentially, lead has a very damaging effect on the body’s nervous system. It causes the critical life giving messages, sent from the brain to every cell and organ in our body, to become distorted. This results in the onset of a chain of permanent adverse health effects.
Every household with indoor plumbing has some level of lead in the tap water that represents a health risk. The biggest tragedy of lead contamination from drinking water is that it is completely preventable. By taking a few simple steps, beginning with Point-Of-Use filtration of our drinking water, we can virtually eliminate the crippling effects of lead on our society, and most importantly on our children.
Next to hardness, the presence of iron is probably the most common water problem faced by consumers and water treatment professionals. The secondary (aesthetic) maximum contaminant levels (MCL) for iron and manganese are 0.3 milligrams per liter (mg/l) and 0.05 mg/l, respectively. Iron and manganese in excess of the suggested maximum contaminant levels (MCL) usually results in discolored water, laundry, and plumbing fixtures.
Small amounts of iron are often found in water because of the large amount of iron present in the soil and because corrosive water will pick up iron from pipes. Clothing washed in water containing excessive iron may become stained a brownish color. The taste of beverages, such as tea and coffee, may also be affected by iron. Manganese produces a brownish color in laundered clothing, leaves black particles on fixtures and as with iron, affects the taste of beverages, including coffee and tea.
Well water from the faucet or tap is usually clear and colorless. However, when water containing colorless, dissolved iron is allowed to stand in a cooking container or comes in contact with a sink or bathtub, the iron combines with oxygen from the air to form reddish-brown particles (commonly called rust). Manganese forms brownish-black particles. These impurities can give a metallic taste to water or to food.
The rusty or brown stains on plumbing fixtures, fabrics, dishes, and utensils cannot be removed by soaps or detergents. Bleaches and alkaline builders (often sodium phosphate) can make the stains worse. Over time, iron deposits can build up in pressure tanks, water heaters, and pipelines, reducing the quantity and pressure of the water supply.
Unluckily, iron and manganese can often be quite difficult to treat. This is due primarily to the fact that iron can be present in several forms, and each form can potentially require a different method of removal.
Types of Iron
There are three main forms of iron and manganese. Other types are much rarer:
- Ferrous – This type of iron is often called “clear water iron” since it is not visible in poured water. It is found in water which contains no oxygen, such as water from deep wells or groundwater. Carbon dioxide reacts with iron in the ground to form water-soluble ferrous bicarbonate, which, in the water, produces ferrous ions (Fe++).
- Ferric – Ferric iron is also known as “red water iron”. This type of iron is basically ferrous iron which has been exposed to oxygen (oxidized), usually from the air. As carbon dioxide leave the water, oxygen combines with the iron to form ferric ions (Fe+++). These oxidized particles are generally visible in poured water.
- Bacterial Iron – Slime depositing in toilet tanks or fouling water filters and softeners is a good indication of the presence of bacterial iron. Better described as iron biofouling, the iron bacteria problem is both complex and widespread. It attacks wells and water systems around the world in all sorts of aquifer environments, both contaminated and pristine. In some places, it causes great damage; in others, it is considered a minor nuisance.
Treatment Methods
Iron Bacteria
Iron bacteria can be controlled by periodic well chlorination or it can be treated in the building. The treatment involves the following: Chlorination, retention, filtration. Activated carbon is usually used as the filter material so the excess chlorine can also be removed.
Ferric Iron
In theory, the elimination of ferric iron is simple – use a properly sized media filter to filter it from the water. In practice, however, there may be other issues:
- Some iron may be present in colloidal form. Unlike ferric iron, which will generally stick together to form large flakes, the tiny particles of colloidal iron do the opposite. Their large surface area and charge relative to their mass causes the individual particles to repel one another. As a result they will not coagulate. Their small size, then, makes them difficult to filter, and a coagulating agent is often required to obtain adequate filtration.
- Most water containing ferric iron also contains ferrous iron. This can add complexity to the process, since some of the methods for removing ferrous iron will also remove ferric iron.
Ferrous Iron
There are a variety of ways for removing ferrous iron, each with its own strengths and limitations. These methods fall into two categories: Ion exchange and Oxidation / filtration.