What type of water purifier should I buy?
02 Jul, 2008, 13:55 pm IST
'How do I purify drinking water and what is the type of water purifier I should buy?' -- this is a question that many of you would be faced with, given the rising water-pollution levels and the increased ensuing risk of contracting water-borne diseases. In fact, many of you might be facing issues of water not purifying well and fit enough for the purpose of drinking, despite having a water purifier at home. This might be a stage when you might want to consider upgrading to a RO water purifier. But before we advise you on how to go about doing that, let's explore the concept of different methods of water purification and their suitability.
Keeping these points in mind, let's move on to different methods of water purification and their suitability for you.
Reverse Osmosis technology
Reverse Osmosis removes dissolved solids of and above the size 0.0009-0.007 microns. It is used to remove dissolved impurities from water through the use of a semi-permeable membrane. It involves the reversal of flow through a membrane from a high salinity solution to the high purity, or permeate stream on the opposite side of the membrane. Pressure is used as the driving force for the separation. This means that through the reversal flow, RO not only removes the impurities, it also desalinises the water. It reduces the TDS of water by around 90 percent.
Reverse osmosis purifier is needed in following circumstances:
- If your water supply is from borewell.
- If your water is hard and salty, or has a TDS (Total Dissolved Solids) level above 500 mg/ltr.
- If you are located near an industrial belt or any contaminated source, due to which your ground water must be having harmful chemicals such as heavy metals, nitrates, arsenic, fluorides, which even in small traces are harmful.
- If you are hypertensive or have heart disease or weak kidneys.
RO purification is the most rigorous and complicated process; it can work wonders under the above-mentioned conditions. But when used to treat low TDS level water, it may produce water that will almost be without any minerals and thus may not be suitable for human consumption. Hence, for water with not very-high level of TDS, there are other purification techniques available.
Tips on Buying a Water Purifier
Ultrafiltration removes dissolved solids of and above the size 0.005-0.1 microns. It is capable of removing solids, bacteria and viruses. Ultrafiltration purifier is recommended for the areas where TDS level is below 500 mg/ltr; it’s especially useful for areas having irregular electricity supply, given that it works without electricity. It requires low maintenance; and life span of its purification membranes is long. Ultrafiltrarition does not reduce TDS of water considerably. It is usually used in large water treatment plants; its presence in domestic water purification is quite limited. But ever since BARC (Bhahbha Atomic Research Centre) India developed "on-line domestic water purification device" which is based on polysulfone type of ultrafiltration membrane, and passed the know-how to different Indian firms, Ultrafiltration system is fast gaining acceptance as the preferred solution. Some of the models that use this method are: Hemkund-Wall Mounted, Eureka Forbes AQUAGUARD Ultra and Kent-SMART- UF.
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Nanofiltration removes dissolved solids of and above the size of 0.0009-0.007 microns. It is capable of removing solids, bacteria and viruses. Nanofiltration purifier removes around 50-60 percent of solids. So if water has high TDS (Total Dissolved Solids) levels (say more than 500 mg/Ltr) then reverse osmosis is advisable, while Nanofiltration is suitable for area having TDS (Total Dissolved Solids) level in region of 300-400 mg/Ltr as it retains 50 percent of minerals and improves taste too. Nanofiltration is usually used in large water plants or liquid treatment plants. Its presence in domestic water purification is limited. One such model for domestic water purification that uses Nanonfiltration is Eureka Forbes-AQUAGUARD TOTAL NF.
Since TDS level and the quantity of contamination determine the suitable water purification method, it’s recommended that you get your water tested for the same, before you decide which type of water purification method you’d settle for. After you figure that out, the next choice will be about which water purifier model to buy. We recommend you buy that from a company with good service network, particularly when you are buying a RO system, since it requires periodic professional intervention, to run efficiently. Companies charge anywhere between Rs 3500- Rs 4000 for AMC (Annual Maintenance Contract) required for RO purifiers, which includes servicing, as well as replacement of parts with exhausted working life.
Unknown water source
Some of our users also ask us about which type of water purifiers to choose when the water source is uncertain or unknown. Many of you sometimes receive rationed corporation water and some other time well-water, which is usually high in hardness. One option for you is to buy Eureka Forbes-AQUAGUARD TOTAL SENSA. Its Blu-G technology senses the quality of water, then auto-selects the best water purification technology-either UV or RO- for treating input water. This water purifier is also useful for people who are frequently required to relocate, and deal with the subsequent water-quality-changes.