Water purifiers has different types of filter stages but what kind of contaminant does each type filter out? What should you look for when buying a water purifier for your home.
A lot of minerals are found naturally in water and are important for the human body but consuming an excess amount of it can cause many diseases. A good water purifier removes the excess salts, suspended particles and microbes, and retains its essential vitamins and minerals. With so many manufacturers in the water purification industry these days, it is difficult to know which is good, which isn’t and which meets necessary standards.
Both water filters and water purifiers work on the same mechanical principle. They first suck up raw water which is contaminated, filter out impurities ranging from sediments to micro-organisms and then dispense clean water. However there is one big difference between the two – a purifier can remove viruses and bacteria that filters cannot remove. Some purifiers use chemicals and others use an electro-static charge to kill or capture viruses.
Active Carbon filter:
This kind of filter is used to purify soluble gases such as chlorine, carbon monoxide, nitrogen, ammonia and organic material like dead algae, leaves or any other dead thing washed into a water body. The porous nature of the carbon (charcoal) helps to absorb chlorine and pollutants such as pesticides. Generally, household carbon filters come with a lining of activated silver that kills bacteria. (To read about technology that uses indigenous coal to make activated carbon click here).
It is a concrete or plastic box that is filled with layers of sand and gravel, which removes pathogens (micro-organisms in water that make us sick) and suspended solids from contaminated water. Water (it should be free from dangerous chemicals since the filter cannot remove most of the chemicals) is poured into the top of the filter and collected in a safe storage container. The organisms which cause infectious. Bacteria and other micro organisms grow in the top 2cm of sand, which is called the biolayer. The micro-organisms at the biolayer eat away the pathogens in the water thereby improving the water quality. It removes suspended particles and pathogens and can filter 12-18 liters each batch.
Reverse Osmosis (RO) system offers a multi-stage filtration of water by combining active carbon and also particle filtration. Here, the tap water is made to pass through a membrane (a polymer film) that has very small-sized pores and this weed out minerals and micro-organisms in water. The impurities collected are then flushed out through an outlet pipe. A RO water purifier improves the taste of water but, it is difficult to say that the water will be 100 percent safe as at times due to holes (because of a manufacturing defect or due to wear-and-tear) in the filter, some bacteria can get through the filter. RO filters are recommended for places where the problem with the water is its high content of dissolved minerals. The darker side in a RO purifier is that there are chances that the membranes in these filters drain out some of the necessary minerals too. Also, it requires a continuous water supply to function and can be fixed to only one water tap.
These are hollow cylinders that are usually made from clay mixed with a combustible material like sawdust, rice husks or coffee husks. These filters drain out bacteria in the water through the small sized pores in them. It removes chlorine and E. coli bacteria up to 99%. Its safe storage capacity prevent water to get decontaminated.
Ion exchange resins filters:
Here the water is passed through resins that soften water by absorbing the minerals present. These filters can soften the water by sucking up the salts present and can also completely de-mineralize the water if they are made accordingly.
Which one to buy?
There are more than ten brands of water purifiers in the market- Tata Swach, Eureka Forbes, Kent, Pureit, etc. Each of these product differs in cost, type of filter they use and the method of purification. Most water purifiers today combine two/three techniques (discussed under the topic- ‘what is the use’ in this note) together. For instance, Eureka Forbes’ Acquaguard Protect Plus combines advantages of a RO purifier and UV sterilization. Hindustan Unilever’s Pureit Marvella UV provides the benefit of UV sterilisation as well as offers filtration through an activated carbon filter. Advanced model of water purifiers that offer a combination of technologies will cost anywhere between Rs 8000 and Rs 15000. To read more about different purifiers along with the review given by consumers, click here.
Water purifiers have become an essential part of every kitchen now and manufacturers of these products are competing to garner market share. The advantage for a consumer here is that she/he can expect good discounts in these products, especially, when buying during a festive season aquagran water solution has special exchange offer with 2 years warranty. know more about click here.