Your Comprehensive Guide to Frequently Asked Questions
Water is a tasteless, odorless and nearly colorless liquid. Water is a molecule with 3 atoms: 2 hydrogen and 1 oxygen. Because oxygen is more electronegative, the oxygen end of the water molecule has a partial negative charge, while the hydrogen end a partial positive charge. So, water molecules are polar, and that is the reason why water can do amazing things.
Human needs water to survive. Water is where our biological reactions take place and also an important metabolite in the process. Because water molecules are polar, they can attract other polar molecules and ions. This polarity gives water the ability to dissolve many substances, making it the "universal solvent". Certain chemical reactions occur when reactants make contact with each other in the water, especially with energy influx, and that was how life began some 4 billion years ago. In our body, water is also the solvent that transports many essential molecules, like oxygen and nutrients, and metabolic waste products, like ammonia and carbon dioxide, in blood and lymphatic vessels and through biological tissues and membranes.
The impact of water pollution on human health is significant. Dirty water may irritate our skin and give us skin diseases. If ingested, dirty water may cause diarrhea and many other diseases. According to US EPA, polluted drinking water can cause health effects, such as gastrointestinal illnesses, nervous system or reproductive effects, and chronic diseases such as cancer.
Sometimes water pollution can occur due to natural causes such as volcano eruptions, animal waste, algae blooms and residue from storms and floods. But, more often now water pollution is caused by human activities. Industrialization, agricultural production, and urban life all have resulted in the degradation of the environment and water quality. Globally, it is estimated that 80% of industrial and municipal wastewater is discharged into the rivers and oceans without any prior treatment. The proportion is even higher in less developed countries, where sanitation and wastewater treatment facilities are severely lacking.
There are many possible pollutants in water, which may be broadly divided into following 4 categories: 1. Particles: dirt, dust, sand, rust, and sediments, etc., insolubles which have a physical size and can be captured with a net-like filter (sediment filter). 2. Solutes: Soluble substances in water, chemicals like nitrates, pesticides, solvents, etc., most give rise to bad smells, which can be removed by activated carbon. 3. Ions: hard ions like calcium, magnesium, sulfur, and iron (the main 4) can be treated with resins or descalers. Heavy metals would need RO or resins. 4. Microbes: waterborne microorganisms like bacteria and viruses. Disinfection by UV, ozone, chlorination, germicidal filters, or membrane separation.
Sediment filters are net-like physical barriers that can trap insolubles greater than their pore size. Some commonly used sediment filters include sand beds, polypropylene (PP), ceramics, and membranes.
Activated carbon is a form of carbon commonly used to adsorb organic and inorganic chemicals in water and air, among many other uses. Activated carbon is made from charcoal, which has a specific surface area of around 5.0 m2/g. The charcoal is first being subjected to 900 degrees Celsius in a tank without oxygen then to another tank with argon and nitrogen to 1200 degrees Celsius. The carbon kernel is expanded and creates small, low-volume pores that has a high surface area, in excess of 3,000 m2/g. It is this high degree of microporosity that makes activated carbon an effective adsorbent.
When groundwater percolates through soils and rocks, it picks up mineral contents. Water with high concentrations of divalent cations (CaCO3 > 60 ppm), such as calcium and magnesium, is called "hard water." While hard water doesn't really pose much health risks to human, it can causes some damages to human, plumbing, and especially water-using appliances. Hard water will leave white chalky mineral stains on the water fixtures, make soap not able to foam properly, and let your hair/skin feel very dry after shower. Hard water can cause scale buildup in your plumbing and water-using appliances like kettles and water heaters, reducing product service life while increasing energy costs. Hard water is especially a major problem in industrial settings as it may cause breakdowns in boilers or cooling towers, etc.
There are several different ways to remove hard ions in water, and they include distillation, washing soda (sodium carbonate), ion-exchange resins, and reverse osmosis (RO) filtration, etc. Among them, the first two can be DIYs by batch. For higher volume applications, resins and RO systems are more applicable.
Water with a high concentration of hard ions is called hard water. Water treatments that can remove hard ions from water are called water softeners, like ion-exchange resins. Another technique to treat hard water is by changing the chemistry of hard ions. The hard ions are still present in water but, due to chemical structure change, they will not form the scale build-up problem. The media that can change hard ion chemistry are called water conditioners.
It depends on the applications. Both have some pros & cons. Water softeners work by replacing calcium ions in water with a specific cation coated on the resins. And some cations may introduce some other negative impact on use of water. Sodium cation exchange resin uses sodium chloride (salt) and is a cheap resin. But, it increases the amount of sodium in the water and creates a threat to users, environment, and water treatment facilities. As such, sodium-based water softeners are banned in several States in America, including Texas and California. Mixed-bed resins use hydrogen (H+) and hydroxide (OH-) to remove ions and the two groups form H2O water. Mixed-bed resins can reduce ions in water without creating another unwanted ion. But, the mixed-bed is a lot more expensive. Thus, only certain applications require the mixed-bed. By comparison, most water conditioners are much more affordable and can equally reduce scale build-up on fixtures and appliances, make showers more pleasant, and bring back softer skin and hair.
Polyphosphates are probably the most widely used water conditioners at present. Polyphosphates are sequestering agents that remove inorganic contaminants (iron, manganese, calcium, etc.) in water and also to maintain water quality (inhibit corrosion, scale, bio-film, reduce lead and copper levels) in the piping. Polyphosphates are nature occurring and widely used in water treatment industries worldwide. They are approved by US FDA and generally considered safe.
A prefiltration system is a water purification process which does up to micron (0.001 mm) level purification at water incoming end. The filtered water would look clean and has no bad smell nor water stains and is good for most utility uses, like cleaning. The water may not be potable as the microbes are not treated yet. To ensure water safety, a disinfection process is needed.
Total Dissolved Solids (TDS) is a commonly used index in the water industry for describing water quality. TDS refers to the total concentration of dissolved organic and inorganic substances in water, basically anything not H2O. TDS may originate from just about anywhere, such as natural sources, urban run-offs, industrial wastewater, agricultural chemicals, and even rust from piping, etc. TDS are measured in milligrams per liter, or PPM (parts per million). In general, the higher the reading, the higher level of non-water substances, i.e. impurities, are present in water. TDS 200 would denote there is around 200mg of impurities in a liter of water sample. So, the lower the TDS reading, the more pure the water is. For example, sea water may have a TDS reading of several thousands. That for deepwell water may be in the range of 300 - 500. Piped water from waterworks may have a TDS less than 200. RO purified water will have a TDS less than 12.
By definition, mineral water is water from a natural spring that contains various minerals, such as salts and sulfur compounds. But, in the Philippines, it only means water with mineral ions, no matter what the source is. In water business, there are two ways to produce mineral water. One is to do only prefiltration and leave mineral ions in water untouched. This is a cheaper approach, but there a risk of possible bad ions in water, like lead or mercury. The other one is much more expensive and that is to purify water with reverse osmosis (RO). RO removes almost all ions in water, good or bad. Then the RO purified water is enriched with a mineral post-filter, a process known as remineralization. This way, the water only contains known good ions, like calcium, and has little bad ones.
Yes, UV light can be effective against most microorganisms provided the water is purified. At an intensity of 254nm, UV light damages bacterial DNA. The harmful microorganisms exposed to the germicidal UV light become inactivated and will not be able to grow. But, UV light also has limitations. UV light can only travel in a straight line so any shadow or obstruction will reduce its efficiency. Unfiltered or partially filtered water that still has particles can either absorb or scatter UV light. Shadows created by particles may also protect microorganisms to pass through UV safely. Thus, water should be purified before going into a UV filter, and to ensure safety a redundant germicidal filter is recommended.
The ACT (Ag-Cu-Ti, Silver-Copper-Titanium) filter is a medical-grade alloy thin film within an activated carbon block. Silver is an effective anti-microbial. The positively charged silver ions (Ag+) can oxidize the cell membrane and bind to the microbial DNA, and thereby killing the microorganism. The ACT filter gives a > 99.5% bacterial killing rate. The activated carbon is also capable of removing some heavy metals such as lead (Pb), mercury (Hg), chromium (Cr), and cadmium (Cd).
Ceramics are made with clay then shaped and fired in kiln. Ceramics have tiny pores on the surface, a nominal pore size of 0.3 micron, small enough to block larger bacteria, like E-coli, but not other smaller bacteria and viruses.
Ultrafiltration (UF) is a membrane with pore sizes range between 0.1 – 0.01 micron, which can capture mold and bacteria but NOT viruses nor heavy metals. Hepatitis-A/C viruses for example can penetrate thru UF membrane.
Reverse Osmosis (RO) is a membrane technology. With pore sizes as small as 0.0001 micron, RO is the ultimate of water filtration technologies now available on the market. RO is able to remove >95% of all pollutants, from nitrates, chlorine, pesticides, to viruses, bacteria, heavy metals, and organic carcinogens like PBBs, dioxins, and the likes.
The choice between RO water and mineral water is very personal. If you are looking for taste and mineral content, mineral water is a better option, provided that it is certified safe. And if you want to reduce your exposure to toxic substances, RO water may be the better choice. Partially filtered mineral water exposes you to unknown health risks as bad substances are not treated. Many mineral water vendors say their mineral water increases your calcium intake, which is an important mineral our bodies need. While that sounds good, you need to know if it has any of the bad minerals, like lead or mercury. Plus, drinking water is not a good source of daily calcium intake. To get 1000 mg calcium from water, one may need to drink 20 liters of very hard water in one day, impractical and also high risk for water intoxication. Food is still our best source for nutrients.
De-ionization (DI), aka demineralization, means the removal of ions in water. Ions are negatively or positively charged atoms or molecules in water. Many industries, such as pharmaceuticals, semiconductor, and medical device, etc., require "extremely pure water" for product cleaning, rinsing, or just as an ingredient. The ions are considered impurities and must be removed from the water. Mixed-bed resins use hydrogen (H+) and hydroxide (OH-) to remove ions and the two groups form H2O water. Mixed-bed resins can reduce ions in water without creating another unwanted ion. With our proprietary ion exchange resin, Onarres designs and builds DI Systems that can easily deliver DI water with a resistivity reading higher than 16 MΩ-cm at a fraction of the cost for an equivalent EDI system.
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Onaress Water Filters
S : 0939-778 4625
G : 0995-907 5092
Onaress Water Filters
S : 0939-778 4625
G : 0995-907 5092
© 2024 Onarres Water Filters. All Rights Reserved