Here is an essay on the ‘Water Treatment Methods’ for class 8, 9, 10, 11 and 12. Find paragraphs, long and short essays on the ‘Water Treatment Methods’ especially written for school and college students.

Essay on the Water Treatment Methods

Essay Contents:

  1. Essay on Boiling
  2. Essay on Distillation
  3. Essay on Reverse Osmosis
  4. Essay on Water Filters
  5. Essay on Bottled Water
  6. Essay on Ultra Violet Light
  7. Essay on Water Softeners
  8. Essay on Water Deionizers
  9. Essay on Ozonation
  10. Essay on Activated Alumina
  11. Essay on ‘Altered Water’

Essay # 1. Boiling:

In an emergency, boiling is the best way to purify water that is unsafe because of the presence of protozoan parasites or bacteria.

If the water is cloudy, it should be filtered before boiling. Filters designed for use when camping, coffee filters, towels (paper or cotton), cheesecloth, or a cotton plug in a funnel are effective ways to filter cloudy water.

Place the water in a clean container and bring it to a full boil and continue boiling for at least 3 minutes (covering the container will help reduce evaporation). If you are more than 5,000 feet above sea level, you must increase the boiling time to at least 5 minutes (plus about a minute for every additional 1,000 feet). Boiled water should be kept covered while cooling.

The advantages of boiling water include:

(i) Pathogens that might be lurking in your water will be killed if the water is boiled long enough.

(ii) Boiling will also drive out some of the Volatile Organic Compounds (VOCs) that might also be in the water. This method works well to make water that is contaminated with living organisms safe to drink, but because of the inconvenience, boiling is not routinely used to purify drinking water except in emergencies.

The disadvantages of boiling water include:

(i) Boiling should not be used when toxic metals, chemicals (lead, mercury, asbestos, pesticides, solvents, etc.), or nitrates have contaminated the water.

(ii) Boiling may concentrate any harmful contaminants that do not vaporize as the relatively pure water vapor boils off.

(iii) Energy is needed to boil the water.

Essay # 2. Distillation:

In many ways, distillation is the reverse of boiling. To remove impurities from water by distilla­tion, the water is usually boiled in a chamber causing water to vaporize, and the pure (or mostly pure) steam leaves the non-volatile contaminants behind. The steam moves to a different part of the unit and is cooled until it condenses back into liquid water. The resulting distillate drips into a storage container.

Salts, sediment, metals — anything that won’t boil or evaporate — remain in the distiller and must be removed. Volatile organic compounds (VOCs) are a good example of a contaminant that will evaporate and condense with the water vapor. A vapor trap, carbon filter, or other device must be used along with a distiller to ensure the more complete removal of contaminants.

The advantages of distillation include:

1. A good distillation unit produces very pure water. This is one of the few practical ways to remove nitrates, chloride, and other salts that carbon filtration cannot remove.

2. Distillation also removes pathogens in the water, mostly by killing and leaving them behind when the water vapor evaporates. If the water is boiled, or heated just short of boiling, pathogens would also be killed.

3. As long as the distiller is kept clean and is working properly the high quality of treated water will be very consistent regardless of the incoming water—no drop in quality over time.

4. No filter cartridges to replace, unless a carbon filter is used to remove volatile organic com­pounds.

The disadvantages of distillation include:

(i) Distillation takes time to purify the water. It can take two to five hours to make a gallon of distilled water.

(ii) Distillers use electricity all the time the unit is operating.

(iii) Distillers require periodic cleaning of the boiler, condensation compartment, and storage tank.

(iv) Countertop Distillation is one of the more expensive home water treatment methods, using $0.25 to $0.35 of electrical energy per gal­lon of distilled water produced – depend­ing on local electricity costs. The cost of ownership is high because you not only have the initial cost of the distillation unit to consider, but you also must pay for the electrical energy for each gallon of water produced. If it cost you $0.25 to distill each gallon, and you purified 10 gallons per week, you would pay $130 for your 520 gallons of distilled water each year.

(v) Most home distillation units require elec­tricity, and will not function in an emer­gency situation when electrical power is not available.


Essay # 3. Reverse Osmosis (RO):

Water pressure is used to force water molecules through a membrane that has extremely tiny pores, leaving the larger contaminants behind. Purified water is collected from the “clean” side of the membrane, and water containing the concentrated contaminants is flushed down the drain from the “contaminated” side.

The average RO system is a unit consisting of a sediment/chlorine pre filter, the reverse-osmosis membrane, a water storage tank, and an activated-carbon post filter. They cost from about $150 to over $1,500 for point of use systems.

The advantages of reverse osmosis include:

1. Reverse osmosis significantly reduces salt, most other inorganic material present in the water, and some organic compounds. With a quality carbon filter to remove any organic materials that get through the filter, the purity of the treated water approaches that pro­duced by distillation.

2. Microscopic parasites (including viruses) are usually removed by properly functioning RO units, but any defect in the membrane would allow these To Storage Tank organisms to flow undetected into the “filtered” water — they are not recommended for use on biologically unsafe water.

3. Though slower than a carbon or sediment water filter, RO systems can typically purify more water per day than distillers and are less expensive to operate and maintain.

4. Reverse Osmosis systems also do not use electric­ity, although because they require relatively high water pressure to operate, they may not work well in some emergency situations.

The disadvantages of reverse osmosis include:

1. Point of Use RO units make only a few gallons of treated water a day for drinking or cooking.

2. RO systems waste water. Two to four gallons of “waste” water are flushed down the drain for each gallon of filtered water produced.

3. Some pesticides, solvents and other volatile organic chemicals (VOCs) are not completely- removed by RO. A good activated carbon post filter is recommended to reduce these con­taminants.

4. Many conditions affect the RO membrane’s efficiency in reducing the amount of contami­nant in the water. These include the contaminant concentration, chemical properties of the contaminants, the membrane type and condition, and operating conditions (like pH, water temperature, and water pressure).

5. Although RO filters do not use electricity, they depend on a relatively high water pressure to force the water molecules through the membrane. In an emergency situation where water pressure has been lost, these systems will not function. However, if a high quality activated carbon filter is used for the post filter, it could probably be disconnected and used to siphon water through in an emergency to reduce many contaminants.

6. RO systems require maintenance. The pre and post filters and the reverse osmosis mem­branes must be changed according to the manufacturer’s recommendation, and the storage tank must be cleaned periodically.

7. Damaged membranes are not easily detected, so it is hard to tell if the system is functioning normally and safely.

Reverse Osmosis

A reverse-osmosis system is a good treatment option for people who have unacceptably high levels of dissolved inorganic contaminants in their drinking water which cannot be removed effectively or economically by other methods.

Water from shallow wells in agricultural areas that contains high nitrate levels is a good example of a situation where RO would make sense. Most people, however, who are using municipal water that is subject to EPA regulations usually have acceptably low levels of nitrates. Maximum nitrate levels should be able to be determined by requesting a water quality report from your local water provider.

Essay # 4. Water Filters:

The topic of water filters is complicated because there are so many models available (over 2,500 different models manufactured by more than 500 companies), and because there are so many types of filtration strategies and combinations of strategies used. The basic concept behind nearly all filters, however, is fairly simple. The contaminants are physically prevented from moving through the filter either by screening them out with very small pores and/or, in the case of carbon filters, by trapping them within the filter matrix by attracting them to the surface of carbon particles (the process of adsorption).

i. There are two main types of filters (sediment and activated carbon), and sometimes they are combined into a single unit. A third type, which will be considered as a separate topic, is reverse osmosis.

ii. You will read about micron or sub-micron filtration. This is a measure of how good the filter is at removing particles from the water — smaller is better. A micron is a unit of measure— one micron is about 1/100 the diameter of a human hair. A filter that removes particles down to 5 microns will produce fairly clean-looking water, but most of the water parasites, bacte­ria, Cryptosporidia, giardia, etc., will pass through the pores. A filter must trap particles one micron or smaller to be effective at removing Cryptosporidia or giardia cysts. Viruses can­not be effective removed by any filtration method. In theory, reverse osmosis will remove viruses, but a small flaw in the membranes would allow viruses to pass undetected into the ‘filtered’ water.

iii. A benefit of all home filtration systems is that they are passive. That is, they require no electricity to filter the water, and normal home water pressure is used to force the water though the filter. The only routine maintenance required is periodic replacement of the filtra­tion element. As long as the cost of the replacement filter elements is reasonable, owning an even a high-end water filter can be very inexpensive if you look at the long term costs and compare it with other solutions.

Sediment Filters — Solid particles are strained out of the water:

1. Fiber Filters:

These filters contain cellulose, rayon or some other material spun into a mesh with small pores. If you take a piece of cloth and pour water containing sand through it you will get the picture. Suspended sediment (or turbidity) is removed as water pressure forces water through tightly wrapped fibers. Some small organic particles that cause disagreeable odors and taste may also be removed.

These filters come in a variety of sizes and meshes from fine to coarse with the lower micron rating being the finer. The finer the filter, the more particles are trapped and the more often the filter must be changed. Fiber filters are often used as pre-filters to reduce the suspended contaminants that could clog carbon or RO filters. Fiber filters will not remove contaminants that are dissolved in the water, like chlorine, lead, mercury, trihalomethanes or other organic compounds.

2. Ceramic Filters:

Ceramic filters are much like fiber filters and use a process where water is forced through the pores of a ceramic filtration media. This provides mechanical filtration only. This type of filter can reduce asbestos fibers, cysts (if the pores are one micron or smaller), some bacteria (with pore sizes in the 0. 2 – 0. 8 micron range) and other particulate matter.

Ceramic filters will not remove contaminants that are dissolved in the water, like chlorine, lead, mercury, trihalomethanes or other organic compounds, nor will they remove viruses. These filters may be used as a back-end to an activated carbon filter to provide a more thorough removal of contaminants.

3. Activated Carbon Filters:

Activated carbon (AC) is particles of carbon that have been treated to increase their surface area and increase their ability to adsorb a wide range of contaminants – activated carbon is particularly good at adsorbing organic compounds. You will find two basic kinds of carbon filters granular activated carbon (GAC) and solid block activated car­bon (SBAC).

Contaminant reduction in AC filters takes place by two processes, physical removal of contaminant particles, blocking any that are too large to pass through the pores (obviously, filters with smaller pores are more effective), and a process called adsorption by which a variety of dissolved contaminants are attracted to and held (adsorbed) on the sur­face of the carbon particles. The characteristics of the carbon material (particle and pore size, surface area, surface chemistry, density, and hardness) influence the efficiency of adsorption.

AC is a highly porous material; therefore, it has an extremely high surface area for contaminant adsorption. One reference mentions. The equivalent surface area of 1 pound of AC ranges from 60 to 150 acres (over 3 football fields). Another article states under a scanning electron microscope the activated carbon looks like a porous bath sponge. This high concentration of pores within a relatively small volume produces a material with a phenomenal surface area: one tea spoon of activated carbon would exhibit a surface area equivalent to that of a football field.

Picture of Granular Activated Carbon

AC is made of tiny clusters of carbon atoms stacked upon one another. The carbon source is a variety of materials, such as peanut shells, coconut husks, or coal. The raw carbon source is slowly heated in the absence of air to produce a high carbon material. The carbon is activated by passing oxidizing gases through the material at extremely high temperatures. The activation process pro­duces the pores that result in such high adsorptive properties.

An article about Activated Carbon states that Activated carbon is one of the best tools which can be used to reduce risks to human health and provide an aesthetically pleasing product at reasonable cost. The article also describes how AC works and has some of the best scanning electron microscope pictures of actual AC granules I have seen.

Activated Carbon Filters

The adsorption process depends on the following factors:

(1) Physical properties of the AC, such as pore size distribution and surface area;

(2) The chemical nature of the carbon source, or the amount of oxygen and hydrogen associated with it;

(3) Chemical composition and concentration of the contaminant;

(4) The temperature and pH of the water; and

(5) The flow rate or time exposure of water to AC.

Interesting Article:

What is Activated Carbon, Adsorption, History of AC.

(i) The effectiveness of carbon filters to reduce contaminants is affected by the factors affecting adsorption listed above and three additional characteristics of the filter, contact time be­tween the water and the carbon material, the amount of carbon in the filter, and pore size.

(ii) The length of contact time between the water and the carbon material, governed by the rate of water flow and the amount/volume of activated carbon, has a significant effect on adsorp­tion of contaminants. More contact time results in greater adsorption.

(iii) The amount of carbon present in a cartridge or filter affects the amount and type of contami­nant removed. Less carbon is required to remove taste and odor-producing chemicals than to remove trihalomethanes.

(iv) Pore size characteristics will be discussed in greater detail on the GAC and SB AC pages, but GAC filters contain loose granules of activated carbon while in SB AC filters, the activated carbon is in the form of very small particles bound into a solid, matrix with very small pores.

(v) Because of the filter characteristics, the most effective Point of Use activated carbon filters are large SB AC filtration systems, and the least effective are the small, pour- through pitcher filters.

(vi) Activated carbon filter cartridges will, over time, become less effective at reducing contami­nants as the pores clog with particles (slowing water flow) and the adsorptive surfaces in the pores become filled with contaminants (typically not affecting flow rate). There is often no noticeable indication that a carbon filter is no longer removing contaminants, so it is impor­tant to replace the cartridge according to the manufacturer’s instructions. The overall water quality (turbidity or presence of other contaminants) also affects the capacity of activated carbon to adsorb a specific contaminant.

(vii) It is important to note, particularly when using counter-top and faucet-mount carbon filtra­tion systems, that hot water should NEVER be run through a carbon filter. I have seen warnings about possible damage to the filter from hot water. Perhaps more importantly, hot water will tend to release trapped contaminants into the water flow potentially making the water coming out of the filter more contaminated than the water going in.

(a) Granular Activated Carbon (GAC):

In this type of filter, water flows through a bed of loose activated carbon granules which trap some particulate matter and remove some chlorine, organic contaminants, and undesirable tastes and odors. The three main problems associated with GAC filters are; channeling, dumping, and an inherently large pore size. Most of the disadvantages are not the fault of the activated carbon filtration media, rather, the problem is the design of the filters and the use of loose granules of activated carbon.

The advantages of GAC filters include:

(i) Simple GAC filters are primarily used for aesthetic water treatment, since they can reduce chlorine and particulate matter as well as improve the taste and odor of the water.

(ii) Loose granules of carbon do not restrict the water flow to the extent of Solid Block Activated Carbon (SBAC) filters. This enables them to be used in situations, like whole house filters, where maintaining a good water flow rate and pressure is important.

(iii) Simple, economical maintenance. Typically an inexpensive filter cartridge needs to be changed every few months to a year, depending on water use and the manufacturer’s recommendation.

(iv) GAC filters do not require electricity, nor do they wastewater.

(v) Many dissolved minerals are not removed by activated carbon. In the case of calcium, mag­nesium, potassium, and other beneficial minerals, the taste of the water can be improved and some (usually small) nutrient value can be gained from the water.

The bottom line is that GAC filters are effective and valuable water treatment devices, but their limitations always need to be considered. A uniform flow rate, not to exceed the manufacture’s specifications, needs to be maintained for optimal performance, arid the filter cartridge must be changed after treating the number of gallons the filter is rated for.

The disadvantages of GAC filters include:

(i) Water flowing through the filter is able to “channel” around the carbon granules and avoid filtration. Water seeks the path of least resistance. When it flows through a bed of loose carbon granules, it can carve a channel where it can flow freely with little resistance. Water flowing through the channel does not come in contact with the filtration medium. The water continues to flow, however, so you do not realize that your filter has failed — you get water, but it is not completely filtered.

(ii) Pockets of contaminated water can form in a loose bed of carbon granules. With changes in water pressure and flow rates, these pockets can collapse, “dumping” the contaminated water through the filter into the “filtered” flow.

(iii) Since the carbon granules are fairly large (0. 1mm to 1mm in one popular pitcher filter), the effective pore size of the filter is relatively large (20 – 30 microns or larger). GAC filters, by themselves, cannot bacteria.

(iv) Hot water should NEVER be run through a carbon filter.

(v) Also, if you think of a bed of charcoal that traps an occasional bacterium, picks up a bit of organic material, and removes the chlorine from the water, you can see how these filters might become breeding grounds for the bacteria they trap. You will see warnings about GAC filters suggesting you run water through them for a few minutes each morning to flush out any bacteria.

If you are considering purchasing a GAC filter be sure to ask the represen­tative about what they recommend you do about this potential problem (I was told by one sales person, that if the filter was not going to be used for a few days, I should remove the filtration element, place it in a plastic bag, and store it in the refrigerator until I returned).

(vi) Unless the filter plugs up or you notice an odor in the “filtered water”, it may be difficult to know when the filter has become saturated with contaminants and ineffective. That is why it is necessary to change filter cartridges according to the manufacturer’s recommendation.

(b) Solid Block Activated Carbon (SBAC):

Activated carbon is the primary raw material in solid carbon block filters; but instead of carbon granules comprising the filtration medium, the carbon has been specially treated, compressed, and bonded to form a uniform matrix. The effective pore size can be very small (0. 5-1 micron). SBAC, like all filter cartridges, eventually become plugged or saturated by contaminants and must be changed according to manufacturer’s specifications. Depending on the manufacturer, the filters can be designed to better reduce specific contaminants like arsenic, MTBE, etc.

The advantages of SBAC filters include:

(i) Provide a larger surface area for adsorption to take place than Granular Activated Carbon (GAC) filters for better contaminant reduction.

(ii) Provide a longer contact time with the activated carbon for more complete contaminant reduction.

(iii) Provide a small pore size to physically trap particulates. If the pore size is small enough, around 0.5 micron or smaller, bacteria that become trapped in the pores do not have enough room to multiply, eliminating a problem common to GAC filters.

(iv) Completely eliminate the channeling and dumping problems associated with GAC filters.

(v) SBAC filters are useful in emergency situations where water pressure and electricity might be lost. They do not require electricity to be completely effective, and water can even be siphoned through them.

(vi) SBAC filters do not wastewater like reverse osmosis.

(vii) Many dissolved minerals are not removed by activated carbon. In the case of calcium, mag­nesium, potassium, and other beneficial minerals, the taste of the water can be improved and some (usually small) nutrient value can be gained from the water.

(viii) Simple, economical maintenance. Typically an inexpensive filter cartridge needs to be changed every few months to a year, depending on water use and the manufacturer’s recommendation.

(ix) This combination of features provides the potential for greater adsorption of many different chemicals (pesticides, herbicides, chlorine, chlorine byproducts, etc.) and greater particu­late filtration of parasitic cysts, asbestos, etc., than many other purification process avail­able. By using other specialized materials along with specially prepared activated carbon, customized SBAC filters can be produced for specific applications or to achieve greater ca­pacity ratings for certain contaminants like lead, mercury, arsenic, etc.

The disadvantages of SBAC filters include:

(i) SBAC filters, like all activated carbon filters, do not naturally reduce the levels of soluble salts (including nitrates), fluoride, and some other potentially harmful minerals like arsenic (unless specially designed) and cadmium. If these contaminants are present in your water, reverse osmosis would usually be the most economical alternative followed by distillation.

(ii) Hot water should NEVER be run through a carbon filter

(iii) As SBAC filters remove contaminants from the water they gradually lose effectiveness until they are no longer able to adsorb the contaminants. There is no easy way to determine when a filter is nearing the end of its effective life except that the ‘filtered’ water eventually begins to taste and smell like the unfiltered water. The manufacturer’s guidelines for changing filter cartridges should always be followed.

A few SBAC filtration systems have been certified for arsenic reduction:

What about the inexpensive GAC pitcher filters and faucet mount filters?

What will they do for your water purification needs?

The answer to that question depends on what your water treatment goals are and the amount of filtered water you plan to use. The most popular brands are GAC filters that will some­times also contain granules of an ion exchange medium (you can see and hear the granules rattling around).

(i) They do reduce the level of some contaminants of health concern and thus are better than nothing.

(ii) They are very limited in the type and number of contaminants they remove, typically chlorine and perhaps lead, copper, and/or cysts are reduced.

(iii) At about $5 – $10 for a filter cartridge capable of treating about 35-40 gallons, your filtered water will cost about $0.14 – $0.25 per gallon ($58 – $90 per year if you use 35 gallons per month). If you are using (or would like to use) much more than a gallon per day, and/or would like to remove more than a minimum number of contaminants, you should probably examine other options.

(iv) Since they contain a very small amount of very loose GAC granules, they CANNOT be considered effective treatments for most biological contaminants or chemical contaminants of health concern. The pitcher filters which contain a microfilter are typically certified to reduce cysts. All of these filters are mostly designed to improve the aesthetics of drinking water (taste & odor improvement) and reduce levels of a limited number of harmful con­taminants. They are subject to possible bacterial growth channeling, and all the other prob­lems of larger GAC filters.

(v) How about the Solid Carbon Block faucet mount filters?

(vi) The solid carbon block faucet mount filters are more effective than GAC filters in reducing contaminants.

(vii) These filters, by nature, are quite small, though, and because filter effectiveness is dependent on contact time of the water with the filter media, a larger, high-quality solid carbon block filter will be more effective at reducing contaminants at the same flow rate. The difference is size can be striking – 4 ounces of activated carbon for a faucet mount filter vs. 32 ounces for a high-end filter, over 7 times more filter media.

(viii) Like the pitcher filters, the replacement cartridges for faucet mount filters tend to be rela­tively more expensive (typically $0.14 – $0.25 per gallon) compared to a high-quality solid block activated carbon replacement filter which will filter water for about $0.07 per gallon. Using 2 gallons of filtered water per day would cost between $100 and $180 to replace 4-5 ounce faucet mount cartridges and about $50 to replace a 32 ounce high-end filter.

Essay # 5. Bottled Water:

Did the water in the bottle you just purchased really come from the beautiful spring shown on the label? How can you be sure the water in the bottle is any cleaner or safer than your tap water? How does the cost, both short term and long term, compare with other water purification options?

Bottled water is simply water from some source that a company (or in the case of water vending machines, the consumer) has placed in a bottle for resale. Bottled water can have minimal (or no) processing — as in natural spring or mineral water, or it can be completely filtered and demineralized to nearly pure water and then have minerals added back in to make it taste better.

But, how can you be sure the, water in the bottle you purchased is any cleaner or safer than your tap water? Just like with any of the other water treatment solutions, you will find reputable companies that provide a safe, quality product, and you will find companies that fill their bottles using the local, municipal water. Each company must be evaluated individu­ally (A Review of Bottled Water and a NRDC Discussion of Bottled Water). There are 2 regulatory organizations, 1 trade association, and 1 independent certification organization which contribute to insuring the safety and quality of bottled water.

Bottled Water: Issues and Alternatives:

According to the University of Illinois at Urbana-Champaign, College of Agriculture, Cooperative Extension Service, bottled water is regulated at the federal level, and in some cases, at the state level. Bottled water suppliers who are members of the International Bottled Water Association (IBWA) regulate themselves and are given unannounced inspections by NSF International. Bottled water companies can also have their product certified by NSF International.

Federal Standards:

Bottled water is regulated by the Food and Drug Administration (FDA), which requires manufacturers to submit samples regularly for testing. In the United States, the concentration of contaminants found in bottled water must be less than the “allowable levels” set by the FDA which are essentially the same as the maximum contaminant levels that the EPA requires municipal water supplies to meet.

State Standards:

Individual states must enforce the federal bottled water regulations, but they can also pass stricter standards.

International Bottled Water Association:

The bottled water industry regulates itself through the International Bottled Water Association (IBWA). Bottled water FAQs. The IBWTA sets manufac­turing requirements, which help to ensure that bottlers meet FDA health standards. Bottled water producers who are members of IBWA are inspected annually by an independent laboratory, the National Sanitation Foundation. Through unannounced inspections, members are evaluated on compliance with the IBWA’s performance requirements and FDA Quality Standards.

Not all bottled water manufacturers are members of the IBWA. Of the 475 bottling plants in the United States (in 1994), 250 are members. The label may indicate whether a bottled water comes from a member company.

You might want to check NSF International to see if the bottled water you are interested in pur­chasing is certified. The NSF Bottled Water Certification Program is an annual, voluntary certifica­tion process that includes both extensive product evaluations as well as on-site audits of bottling facilities. The NSF testing program provides for annual unannounced plant inspections covering every aspect of a bottler’s operation, from the source of the water, through the disinfection and treatment process, and including the container closure process. The company also performs exten­sive product testing for over 160 chemical, inorganic, radiological, and microbiological contami­nants. An interesting article from Scientific American magazine on bottled water.

The advantages of bottled water include:

(i) An emergency source of water in the event your primary water source fails or becomes contaminated.

(ii) A convenient source of usually safe water for drinking outside of the home.

(iii) Bottled water, since it does not contain chlorine, and may contain a mix of minerals to enhance flavor, may taste better than untreated tap water.

(iv) Most bottled water will contain fewer contaminants than untreated tap water.

(v) The bottled water industry would like the public to believe that bottled water is more pure and safer than tap water and water produced by other treatment methods. The actual quality of bottled water depends on the bottling company, and most is usually good. High quality home water treatment methods (filtration, reverse osmosis, and distillation) can usually produce water of equal or better quality more economically, however.

The disadvantages of bottled water include:

i. Cost:

Bottled water costs anywhere from $0.25 a gallon for water from a vending machine to $0.50 for generic water jugs you purchase in a store to $1.00 – $1.50 or more for water delivered to your home. If you purchase 10 gallons of bottled water a week, you will spend $260 (at $,50/gal), $520 (at $1.00/’gal), $780 (at $1.50/gal), or more every year.

Many of us are willing to pay extraordinary prices for the availability and convenience of certain products. That 16 ounce bottle of “designer water” you just purchased at the gas station for $0.69 costs $5.52 per gallon, probably more than twice as much per gallon as your gas! Purchasing one 16 oz bottle per day (at $0.69 per bottle) will cost you $248 per year – that’s for a total of 45 gallons. If you were to take a minute to fill your own well-cleaned bottle with filtered or distilled water, however, a 16 oz bottle of water would cost perhaps 1-2 cents a day, or less than $7.30 per year!

ii. Convenience:

Using bottled water requires moving and storing jugs or bottles of water. Water weighs about eight pounds per gallon, or about 40 pounds per five gallon bottle. Failure of a small valve can lead to a big mess, as I discovered after arriving home one evening after a long day at work to find 3 gallons of water soaking into the rug.

iii. Environmental Impact:

Producing bottles uses resources, and unless they are reused or re­cycled, they cause a waste disposal problem. Recycle or reuse the empty bottles, if at all pos­sible. Transporting bottles of water from the bottler to stores or homes also uses resources.

Keep it Clean:

According to the University of Illinois at Urbana-Champaign, College of Agriculture, Cooperative Extension Service, If you choose bottled water after careful investigation, keep in mind that all of your hard work will go to waste if you aren’t careful about keeping your bottled water clean. You have to be faithful in maintaining the hygiene of your bottled water, or you may increase your exposure to bacteria. Bacteria grow best in warm, moist areas.

The wet, warm, threaded cap of an unrefrigerated bottle of water is a perfect place for bacteria to grow; they will begin to grow as soon as you break the seal. If ingested, these bacteria can cause gastrointestinal problems and other health risks. The key is to maintain the cleanliness of your bottles and store them properly.

Follow these hints:

1. Store the bottle in a refrigerator at a temperature above freezing but less than 50 degrees Fahrenheit.

2. Wipe the seal with a clean cloth after each use.

3. Avoid any type of buildup in the bottle cap.

4. If your bottle is refillable, make sure it is well-cleaned and rinsed before refilling. If possible, recycle the old bottle and obtain a fresh sterile, sealed bottle.

Essay # 6. Ultra Violet Light:

Water passes through a clear chamber where it is exposed to Ultra Violet (UV) Light. UV light effectively destroys bacteria and viruses. However, how well the UV system works depends on the energy dose that the organism absorbs. If the energy dose is not high enough, the organism’s genetic material may only be damaged rather than disrupted.

The advantages of using UV include:

(i) No known toxic or significant nontoxic byproducts introduced.  

(ii) Removes some organic contaminants.

(iii) Leaves no smell or taste in the treated water.

(iv) Requires very little contact time (seconds versus minutes for chemical disinfection).

(v) Improves the taste of water because some organic contaminants and nuisance microorganisms are destroyed.

(vi) Many pathogenic microorganisms are killed or rendered inactive.

(vii) Does not affect minerals in water.

The disadvantages of using UV include:

(i) UV radiation is not suitable for water with high levels of suspended solids, turbidity, color, or soluble organic matter. These materials can react with UV radiation, and reduce disinfec­tion performance. Turbidity makes it difficult for radiation to penetrate water and patho­gens can be ‘shadowed’, protecting them from the light.

(ii) UV light is not effective against any non-living contaminant, lead, asbestos, many organic chemicals, chlorine, etc.

(iii) Tough Cryptosporidia cysts are fairly resistant to UV light.

(iv) Requires electricity to operate. In an emergency situation when the power is out, the purifi­cation will not work.

UV is typically used as a final purification stage on some filtration systems. If you are concerned about removing contaminants in addition to bacteria and viruses, you would still need to use a quality carbon filter or reverse osmosis system in addition to the UV system.

Essay # 7. Water Softeners:

Water softeners operate on the ion exchange process (specifically a cation exchange process where + ions are exchanged). In this process, water passes through a media bed, usually sulfonated poly­styrene beads. The beads are supersaturated with sodium (a positive ion). The ion exchange process takes place as hard water passes through the softening material.

The hardness minerals (positively charged Calcium and Magnesium ions) attach themselves to the resin beads while sodium on the resin beads is released simultaneously into the water. When the resin becomes saturated with calcium and magnesium, it must be recharged. The recharging is done by passing a concentrated salt (brine) solution through the resin. The concentrated sodium replaces the trapped calcium and magnesium ions which are discharged in the wastewater. Softened water is not recommended for watering plants, lawns, and gardens due to its elevated sodium content.

Several factors govern the efficiency of a cationic softener:

(i) Type & quality of resin used,

(ii) Amount of salt per cubic foot of resin for regeneration,

(iii) Brine concentration in the resin bed during regeneration,

(iv) Brine flow rate through the resin bed (contact time) during regeneration,

(v) Raw water hardness,

(vi) Raw water temperature — softeners perform better at higher temperatures, and

(vii) Optimal flow rate of hard water through the resin bed.

Although not commonly used, potassium chloride can be used to create the salt brine for soften­ers designed to use KCl. In that case potassium rather than sodium is exchanged with calcium and magnesium. Before selecting an ion exchange water softener, test water for hardness and iron content. When selecting a water softener, the regeneration control system, the hardness removal capacity, and the iron limitations are three important elements to consider. More information on Hard Water and Softening.

The advantages of water softeners include:

i. The nuisance factor of hard water is reduced.

ii. Some other cations like barium, radium and iron may be reduced depending on the manufacturer’s specifications.

The disadvantages of water softeners include:

i. The process of regenerating the ion exchange bed dumps salt water into the environment.

ii. The elevated sodium concentration of most softened water can affect the taste and may not be good for people on low sodium diets, although sodium concentrations are typically quite low relative to sodium levels in most food.

iii. Cation exchange does not reduce the level of anions (like nitrates), or biological contaminants (bacteria, viruses, cysts); nor does the process reduce the levels of most organic compounds.

iv. Typically, approximately 50 gallons of rinse water per cubic foot of resin is required to totally remove hardness and excess salt from the resin after each regeneration.

Essay # 8. Water Deionizers:

Water Deionizers use both Cation and Anion Exchange to exchange both positive and negative ions with H+ or OH ions respectively, leading to completely demineralized water. Deionizers do not remove uncharged compounds from water, and are often used in the final purification stages of producing completely pure water for medical, research, and industrial needs.

A potential problem with deionizers is that colonies of microorganisms can become established and proliferate on the nutrient-rich surfaces of the resin. When not regularly sanitized or regener­ated, ion-exchange resins can contaminate drinking water with bacteria.

Essay # 9. Ozonation:

The formation of oxygen into ozone occurs with the use of energy. This process is carried out by an electric discharge field as in the CD-type ozone generators (corona discharge simulation of the lightning), or by ultraviolet radiation as in UV-type ozone generators (simulation of the ultra-violet rays from the sun). In addition to these commercial methods, ozone may also be made through electrolytic and chemical reactions.

Ozone is a naturally occurring component of fresh air. It can be produced by the ultraviolet rays of the sun reacting with the Earth’s upper atmosphere (which creates a protective ozone layer), by lightning, or it can be created artificially with an ozone generator.

The ozone molecule contains three oxygen atoms whereas the normal oxygen molecule contains only two. Ozone is a very reactive and unstable gas with a short half-life before it reverts back to oxygen. Ozone is the most powerful and rapid acting oxidizer man can produce, and will oxidize all bacteria, mold and yeast spores, organic material and viruses given sufficient exposure.

The advantages of using ozone include:

i. Ozone is primarily a disinfectant that effectively kills biological contaminants.

ii. Ozone also oxidizes and precipitates iron, sulfur, and manganese so they can be filtered out of solution.

iii. Ozone will oxidize and breakdown many organic chemicals including many that cause odor and taste problems.

iv. Ozonation produces no taste or odor in the water.

v. Since ozone is made of oxygen and reverts to pure oxygen, it vanishes without trace once it has been used. In the home, this does not matter much, but when water companies use ozone to disinfect the water there is no residual disinfectant, so chlorine or another disinfectant must be added to minimize microbial growth during storage and distribution.

The disadvantages of using ozone include:

i. Ozone treatment can create undesirable byproducts that can be harmful to health if they are not controlled (e.g., formaldehyde and bromate).

ii. The process of creating ozone in the home requires electricity. In an emergency with loss of power, this treatment will not work.

iii. Ozone is not effective at removing dissolved minerals and salts.


The effectiveness of the process is dependent, on good mixing of ozone with the water, and ozone does not dissolve particularly well, so a well-designed system that exposes all the water to the ozone is important.

In the home, ozone is often combined with activated carbon filtration to achieve a more com­plete water treatment.

Essay # 10. Activated Alumina:

Activated Alumina is a granulated form of aluminum oxide. In this process, water containing the contaminant is passed through a cartridge or canister of activated alumina which adsorbs the con­taminant. The cartridge of activated alumina must be replaced periodically. Activated alumina devices can accumulate bacteria, so treated water may have higher bacteria counts than raw water.

The advantages of activated alumina filters include:

An effective way to reduce levels of fluoride, arsenic, and selenium.

The disadvantages of activated alumina filters include:

The use of other treatment methods would be necessary to reduce levels of other contami­nants of health concern.

Essay # 11. ‘Altered’ Water:

No discussion about water treatment would be complete these days without mention of what I call “altered” water that has been treated in some way to allegedly modify the physical, chemical, or ‘energy’ properties of water to provide some benefit to the body. These treatments fall under a wide range of categories, including: pi mag; oxygenation; hydrogenation; various ‘catalytic’, vortex, magnetic, & photonic treatments; micro-clustering; super-ionization; homeopathic successions; etc.


Oxygenated water, is just one example of the hundreds of ‘altered’ or ‘en­hanced’ water products promoted on the internet and in some health food stores. These products all have several characteristics in common that are discussed in more detail on the Altered Water and Drinking Water Scams pages. It is easier to demonstrate the flaws in Oxygenated water claims than in other products that claim to use some exotic physical or chemical process, but just like oxygenated water, none of the other products are able to withstand critical scientific review.

Regardless of any alleged health benefits, these products are extremely effective at separating customers from their money. I have seen some of this bottled water sell for more than $20 a gallon plus shipping (that’s about 3, 000 times greater than the cost of tap water)! Many of the ‘altered’ water products sell for $10 to $15 per gallon. Water ‘ionizers’ that generate alkaline water produce sodium hydroxide and bleach and sell for up to $5, 000.

Let’s look briefly at one ‘altered’ water example: hiOsilver oxygenated water — soon to be 02Cool Oxygen Water:

Why drink hiOsilver oxygen water? According to the marketing hype, it provides “extra energy and vitality, fresh breath, healthier gums and teeth. We do not know all of the benefits of drinking hiOsilver Oxygen Water. Many people report that they feel energized after a bottle. Studies have been done showing enhanced sports performance for athletes drinking oxygenated water. With hiOsilver, many people report that their headaches disappear, even migraine headaches. One bottle of hiOsilver Oxygen Water and you will see why we are proud of the many benefits it offers over ordinary bottled waters. . . ”

hiOsilver oxygenated water sells for $44 (for twenty four, 16 oz bottles – 3 gallons) but you do get free shipping!

If my math is correct, that’s over $14. 50 per gallon. By comparison, tap water costs around $0, 007 per gallon (2, 000 times less than the oxygenated water). The highest quality filtered water is about $0. 07 per gallon (that is still over 200 times less expensive than the oxygenated water). I suppose some people might be able to justify the exorbitant cost IF the product performed as advertised — but does it?

The super oxygenating water cooler system marketing materials make these ‘exciting’ claim — and a skeptical review:

(i) Extra supply of oxygen to the body for overall health improvement.

(ii) Enhancement of the brain function for clearer thinking and alertness.

(iii) More oxygen to the muscle to increase energy and performance.

(iv) More oxygen to skin cells for healthier, younger looking skin.

(v) Enhanced metabolism and waste removal.

(vi) Enhancement of the body’s ability to fight bacteria and viruses.

(vii) Better absorption of vitamins, minerals and other nutrients.

Some facts to consider when evaluating the oxygenated water hype:

(i) There is less dissolved oxygen in 1 liter of ‘oxygenated water’ than in 1 breath of air. Taking an extra breath of air when exercising would be substantially less expensive than paying $1 to $2 for a litre of these products!

(ii) The primary way to transport oxygen in the body is bound to hemoglobin in the red blood cells. In normal healthy exercisers, hemoglobin leaving the lungs is already 97% to 98% saturated with oxygen.

(iii) The structure of the circulatory system ensures that any oxygen picked up in the digestive system would go through the lungs before reaching the muscles and other tissues. In the lungs any extra oxygen in the blood will reduce the amount of oxygen transferred to the blood — the final oxygen saturation of the hemoglobin would still be 97% to 98%.

(iv) Oxygenating water has no effect on the body’s ability to absorb the oxygen into the blood­stream or transfer it throughout the body.

(v) The concept of obtaining significant amounts of oxygen through the digestive system makes as much scientific and physiological sense as quenching your thirst by inhaling a glass of water into your lungs.

Water that you drink can take up to an hour or more to travel to the intestines where it is absorbed — the water you inhale into your lungs will absorb into your bloodstream almost immediately — so doesn’t it make sense to quench your thirst by inhaling a glass of water? This is not an endorsement for inhaling water. The point is, the respiratory system is designed to absorb oxygen, not water! Oxygenated water makes sense for fish that have specialized structures (gills) for exchanging oxygen and carbon dioxide in an aquatic environment, but not for mammals.

Similarly, the digestive system is designed to absorb water and nutrients, not oxygen! American Council on Exercise (ACE) Study Investigates Super Oxygenated Water Claims — Results of a study done to test health claims.


“At this time, there is no scientific evidence or logical rationale to suggest that drinking super oxygenated water can in any way increase the amount of oxygen in the blood stream,” said Porcari. “Therefore, any potential benefits of super oxygenated water would undoubtedly be attributed to the placebo effect.”

A single breath of air contains more oxygen than a bottle of oxygenated water. Despite advertising claims that oxygenated water can boost sports performance, a study in the Nov. 12, 2003, Journal of the American Medical Association found that compared with tap water, it had no effect on 9 exercise-performance measures in 11 healthy men and women. Ben Goldacre of The Guardian reviews Oxygizer Oxygenated water bottled in Austria.

Oxygen Water:

Are you being ripped off? There’s very little reliable evidence to show that oxygenated (or oxygenized) water has any signifi­cant effect on exercise performance, energy levels, or recovery. This water isn’t going to hurt you, but there’s no reason to believe it’s going to help you substantially.