Purification and Filtration Processes
Micro filtration refers to process to removes any elements larger that 0.1 to 10 microns (micrometre- µm). There are membranes that allow molecules either in a gas or gas form smaller than this to pass through the microscopic membrane. The micro filtration process is fundamentally the same as reverse osmosis. Micro filtration removes all bacteria, protozoa’s, Giardia and Cryptosporidium.
Ultra filtration refers to process to removes any elements larger that 0.005 to 0.10 microns (micrometre- µm). There are membranes that allow molecules either in a gas or gas form smaller than this to pass through the microscopic membrane. The ultra filtration process is fundamentally the same as reverse osmosis. Ultra filtration not only filters out what Micro Filtration but as well as viruses.
Nano filtration refers to process to removes any elements larger that 0.001 to 0.005 microns (micrometre- µm). There are membranes that allow molecules either in a gas or gas form smaller than this to pass through the microscopic membrane. The nano filtration process is fundamentally the same as reverse osmosis.
Nano filtration removes everything ultra filtration plus many nutrient, pesticides and herbicides. It has the ability to remove salts from water, desalination. The process also removes solutes. The filtered water is extremely low of any nutrients below WHO standard guidelines. Nano filtration only practically operates under high water pressure
The electro chemical water purification process refers to when water acts like a conductor when water is between two different elements with different and opposing electrical properties. The water allows charge be transferred between the two elements, a spontaneous electrical current is created. The technical term for the reaction is called an oxidation and reduction reaction, Redox. When an element looses electrons it is called Oxidation and when an element gains an electron it is called reduction. When two elements are place together with a transfer fluid it is called an electro chemical cell. As the electrical current passes through the water, the energy from the electrical charge destroys any live bacteria, oocysts, cysts, viruses and anything else alive.
There are many elements that can be used to generate this voltaic cell (as opposed to electrolytic cell where an external electrical supply is provided). There include carbon, zinc,
Using Electro dialysis in a water purification situation destroys germs, bacteria and cysts through is the process of passing electrical energy through the water. It is accomplished by electrodeionization. It is primarily used for salt water desalination.
Aeration as the name suggests introduces air into the water, in particular oxygen. The oxygen metabolize micro organisms, reduce carbon dioxide as well as it removes methane and hydrogen sulphide. It improves the smell of the water making it good to drink.Aeration is a particularly good where water has a high iron and manganese content, removing the bitter taste of the water. The Aeration process needs to be used in conjunction with another process to remove bad bacteria, cysts and viruses.
Iodine can be uses as a water disinfectant, often referred to water purification. The chemical, iodine has the ability to destroy bacteria, viruses and cysts at appropriate levels of concentration and sufficient time in contact the micro organisms. At low dosages iodine is in effective against Giardia and Cryptosporidium (see WHO guidelines). Iodine requires sufficient contact time with bacteria’s, viruses and cysts to destroy. Short contact with iodine may be in effective.
People with thyroid disorders or pregnant women should not use Iodine in water as it has a major impact. In addition no one should have more than 5 mg of iodine per week. That’s less than 5 drops of un-concentrated iodine.
Chlorine disinfection refers to the process where chlorine is added into the water with the view of killing bacteria, viruses, protozoa cysts like Giardia and Cryptosporidium. Chlorine is an oxidization agent. The chlorine at drinkable levels destroys harmful bacteria but not Giardia and Cryptosporidium cysts.
Chlorine can react to naturally occurring chemicals creating harmful by products such as chloramine (dangerous carcinogen).
Often Chlorine is used in conjunction with other chemicals to avoid this carcinogen. Chlorine Dioxide can be used in conjunction to prevent this reaction to occur.
Chlorine Dioxide Disinfection
Chlorine Dioxide, CIO2, has been used for over 100 years to disinfect water. By adding Chlorine Dioxide, a biocide, in water it becomes an oxidant. The by product of this is chlorite. As an oxidant, it is able destroy bacteria and cysts. It is often used to improve the taste of water, reduce iron and manganese and hydrogen sulphide compounds.There are some low level adverse impacts to human health such as neurotoxicity and reproductive toxicity.
Ultra Violet light
When water is exposed to sunlight it has powerful purification qualities. It is able to eliminated bacteria, micro organisms, cysts, germs and viruses through a natural process. This process has been around for day one and has been proved effective. It is a natural disinfectant.
The Ultra Violet radiation (UV radiation) of sunlight is the effective disinfection component. The UV wavelength that is most effective to destroy germs is at 254 nano metres. The UV radiation can be simulated by non natural means.
For UV water purification to be effective, the UV rays need to have the right combination of length of time, energy levels and contact to destroy dangerous organisms and germs.
The reverse osmosis process refers to passing a fluid through a membrane by applying pressure (hydraulic pressure) to remove unwanted material. Reverse osmosis is usually used with clear water. When used in conjunction with water and the appropriate size membrane, it is able to effective remove bacteria, viruses, cysts, Giardia and cryptosporidium.
It is one of the most used processes to filter/purify water and in used in municipal water plant, commercial buildings, homes as well by the AquaSafeCorp product group.
The forward osmosis process refers to passing a fluid through a membrane without applying pressure (except atmospheric pressure, natural forces) to remove unwanted material. When used in conjunction with water and the appropriate size membrane, it is able to effective remove bacteria, viruses, cysts, toxins, giardia and cryptosporidium.
Forward osmosis is used in conjunction with some solute. The solute material is nominally a sugar based. Forward osmosis is extremely effective to be used to purify and range of liquids including saltwater, urine and brackish water
The draw backs of this forward osmosis are
1. It is very slow to filter the water, and
2. The filtered water may not be suitable for a diabetic due to the added sugars
Activated Carbon- Granulated
Activated Carbon is a natural material. It is derived from coal, charcoal, coconut shell, lignite. It is processed into form granules to make it exceptionally porous creating an enormous surface area that allows either adsorption or chemical reactions. As little as 1 gram of granular activated carbon, equates to a surface area of almost 2000 sq metre.Depending of the sources of the activated carbon made (from where it has been derived) each will have slightly different performance characteristics. For example, bituminous carbon has higher chlorine absorption whereas coconut carbon improves the taste of water.
Activated Carbon can also be treated with certain chemical to use the absorption qualities to destroy bacteria.
With the exceptional porous qualities of the granulated carbon, when water is strained through the granules any chemicals in the water will “stick” to the carbon surface making a small film. (Carbon absorption process). This is effective to remove chlorine, benzene, radon, toxaphene and other naturally and man made compounds.
Water needs to be passed through the slow to allow the surface area to work effectively otherwise the efficiency may be as low as 0%.
Other issues with activated carbon are;
• Activated Carbon (no form) removes bacteria.
• Channelling may occur, that is, water makes a direct path through the granules.
Silver impregnated Granular Activate Carbon
Silver based Granular Activated Carbon has a very small percentage of silver spray, typically 1-2% of the surface area. The silver is meant stop bacterial growth. As water is leached through the granules, the silver becomes prematurely removed into the water supplied.
Distillation is the process of heating of water until its vapour point and then recondensing the steam into a container. The collected water has all the impurities removed. This water is called distilled water.
Distilled water has virtually no minerals. Humans require some of minerals in water for dietary purposes for maintain proper health.
The ozonation process refers to when ozone, O3, is used to purifying water. It is one of the best ways to purify water. Ozone, O3, is an effective oxidizing agent, as it has a very high oxidation potential and has a ½ life of less than 30 minutes making it very effective in make water pure, odourless, colourless and safe. Any organisms, micro organisms, bacteria, oocysts, germs, viral DNA (such as smallpox, herpes and hepatitis) and viral RNA (e.g. measles, mumps, West Nile, rubella and influenza), heavy metals and toxins cannot survive when in contact with ozone.
Ozone is a pollutant at ground level being created by hydrocarbons and nitrogens getting into contact with sunlight.
The ozonation process is typically used in large plants as it requires equipment and energy. It normally is used in with a filtration system.
KDF (Kinetic Degradation Fluxion) Resign is a brand name of a product that has been designed to filter water. It uses a copper and zinc alloys that when water passes through creates an elelectro-chemical oxidation, electrolysis, destroying bacteria. The process is known as "redox". In this process electrons are transmitted between molecules and new elements created. The old elements harmful elements are eliminated. For example chlorine is transformed into chloride. The heavy metals in the water are attracted to the KFD surface due the electrical potential difference.
The KFD is usually used in conjunction with activated carbon (granular).
Ceramic filters are a man made product that is manufactured with a specific designed pores size to allow water filtration, typically 0.5 microns. Ceramic filters can be used in either a forward or reverse osmosis process.
Often silver is used in the ceramic to stop any fungicidal or algaecidel or bactericidal growth. As silver is toxic to human, silver levels must be kept to a minimum. All water filtration systems in the US must be registered with the EPA.
Solid Carbon Block
A solid Carbon Block absorbs viruses nor bacteria and destroying them with “food grade” pesticides or iodine. The pesticide or iodine s is saturated in the Carbon Block. The bacteria and viruses are attracted to the carbon block by “electro-attractive forces”.
Solid carbon blocks do not work well to destroy Protozoa’s cysts, such as Giardia and Cryptosporidium.
Boiling is the most effective in removing bacteria, viruses and the like out of water provided it is boiled at 100oCfor at least several minutes.