When it comes to health and safety, the quality of drinking water is highly important. Contaminated drinking water is a continuous source of health hazards and needs remedial actions to be taken on an urgent basis. The importance of safe water and its relationship with health is widely known. Water should be safe for drinking, cooking, and hygiene. According to the guidelines of WHO, water should be safe to consume in terms of the following four aspects.
This means that drinking water should be free of bio-invaders. Consumption of drinking water contaminated with disease-causing germs is highly fatal in the long run. Children and people in old age are more susceptible as their immunity is not fully developed. It has got immense importance and compromises cannot be made in managing microbial exposure in drinking water. Many local municipalities strive to disinfect such water and chlorine is highly consumed for disinfection of drinking water.
The presence of certain chemicals in the drinking water raises serious health concerns. These chemicals make sometimes water undrinkable due to bad odor, and a peculiar taste and affect the overall appearance. Though some chemicals act as a barrier against certain diseases such as fluoride provide prevention against dental cavities and are added to the supply line by municipalities themselves. Chemicals in drinking water at an acceptable level are not alarming as much as they do not cause health impairment.
Radionuclides sometimes are naturally present in drinking water. Water should be saved from radioactive materials in case they pose a threat to health. Risk mitigation must be ensured if radionuclides are present in water up to a dangerous level. The approach should be preventive whenever the allocation of resources is done for drinking water safety.
WHO says that the water should be acceptable to drink by individuals in terms of its appearance. No one would like to drink muddy and cloudy water. Secondly, acceptability also means that it should not have an unacceptable taste and bad odor. Otherwise, it will affect the hydration in the long run. If microbial, chemical, and physical aspects are not taken into consideration with respect to safety then acceptability will automatically be influenced. All other three contaminations are likely to affect the appearance of water.
RO Water Filter Systems Vs Other Water Purification Methods
There are many water purification methods other than the traditional method of boiling in the marketplace. Reverse osmosis water filter systems are highly in demand as compared to other filtration techniques due to their immense effectiveness.
RO (Reverse Osmosis) Water Filter Systems
The most common and popular purification systems nowadays are reverse osmosis water filter systems. Reverse osmosis is abbreviated as RO. RO water filter systems work on the basis of osmosis a naturally occurring phenomenon. Osmosis refers to the movement of a solvent that is lower in solute concentration towards the solvent of a higher solute concentration when they are separated from each other through a semi-permeable membrane.
A semi-permeable membrane is a membrane that does not let everything pass through it. This tendency of the solvent molecules is known as osmosis. In other words, it can be said that water flows from its high potential where there is less solute towards its lower potential which has more solute dissolved until both water diffuses. This movement keeps on going until both solvents achieve an equilibrium.
This property of water is used in reverse osmosis water filter systems in exactly the opposite way. In RO water filter systems impure water is pushed by a water pump through a reverse osmosis membrane. RO membrane filters the impurities in the water up to 0.0001micron which is just a semi-permeable membrane. For once, the RO membrane removes completely everything from the water.
RO water filter systems usually house different filtration stages to make drinking water pure and safe. These systems use a combination of different purification methods. Sediment filtration and UDF filtration are utilized as initial filtration techniques before water passes through the reverse osmosis membrane.
In addition, RO water filter systems have been designed for many post-filtration water treatments. In the first step in very basic RO water filter systems, water passes through a polypropylene cartridge that purifies impure water from all types of suspended particles such as sand, clay, and silt.
The main purpose of this sediment filter is to protect the reverse osmosis membrane as well as the whole filter from any clogging due to the presence of solid suspended particles. This pre-filtration membrane removes impurities in the water up to 5 µ. In the second step, granular activated carbon and carbon block filters remove the bad taste and odor in the water caused by chlorine and chloramines. Together these two carbon cartridges increase the performance and efficiency of each other and block many VOCs, pesticides, and inorganic compounds along with chlorine.
Reverse osmosis membrane filtration
Pre-filtered water is passed through the reverse osmosis membrane on the principle that a solvent (impure water) is passed from an area of higher concentration to a low concentration of impurities. This removes all remaining impurities from the water that still exist after pre-filtration.
Once the membrane removes completely everything from the water, the water even becomes void of essential minerals. The water at this stage is not fit for drinking purposes as it lacks even essential minerals that are required for the proper functioning of the body. Many advanced reverse osmosis systems have post-treatments as well in order to remineralize water.
In the post-treatment, a mineralization tube enriches the water with the required minerals by adding back the desired level of minerals and nutrients. Another post feature is the taste and odor tube that readjusts the taste of the water making it a desirable one. Advanced systems have more features added such as the adjustment of pH to provide you with alkaline water. This stage softens the water and removes the acidic nature of the water.
We all know that the best water for the body to assimilate all the essential nutrients from the food is alkaline water. Another post feature is an antioxidant filter that sterilizes the water completely. Especially after COVID-19, this system is highly desirable as it contains an anti-microbial filter that removes 99% of the bacteria and germs from the water making it safe and pure to drink. Some RO water filter systems use ultraviolet sterilization as well.
- Ideal for drinking water purposes
- Best under-the-sink placement filter
- Filters water up to 0.0001 microns
- Filter cartridges are easy to maintain
- Multiple Stages of Filtration
- Nourishment and retention of water with mineralization tube
- Odorless water and taste as per your choice
- Alkaline water pH is ideal for body functioning
- Anti-microbial removes 99.99 % of disease-causing organism
- Reverse osmosis membrane has a longer life
- Takes more time to install
- Needs electricity for operation
- Wastage of water due to backwash
- Need storage tank due to slow filtration rate
- RO water filter systems need mineralization tubes for full effectiveness otherwise you will be putting your family’s health at risk
Other purification methods
Another popular method of purification is based on carbon as a filtration media. Carbon-based filters perform purification usually in two forms one is granular activated carbon media known as GAC and the other is carbon block.
Granular Activated Carbon Cartridges are made from acid-washed coconut shells and coal with high concentration of carbon whereas carbon block filter cartridge is made by compressing the loose carbon into a solid compact structure which enhances its capability to absorb impurities massively.
Carbon media removes bad odor and taste from the water improving the acceptability aspect of water. Together they make water void of several chemicals, specifically Volatile Organic Compounds (VOCs), pesticides, hydrogen sulfide, nitrates, heavy metals, and many others etc.
- Best for cooking, and dishwashing
- Ideal for cafes and coffee shops
- Placement is under the sink
- Filters water up to 0.3 to 0.01 micron
- Perform ultra-depth filtration
- Easy to maintain filter cartridges
- Takes less time and space to install as compared with RO water filter systems
- No need for electricity
- No water wastage
- Consistent water supply with no need for storage
- Removal of chlorine and chloramines
- It is not ideal for drinking water purposes
- No protection against bio-invaders such as bacteria and viruses
- No adjustment for pH
KDF media is another form of water purification that is mainly used in shower filters. This media is made up of copper and zinc granules that use oxidation-reduction reactions. This medium removes chlorine, heavy metals, hydrogen sulfide, and some bacteria. It has different variations that are productive for removing different impurities.
- It is less expensive
- Inhibits bacterial and fungal growth
- Easy to install without taking much time
- Works effectively in a combined arrangement with other filtration techniques
- Requires backwashing
- Do not remove some organic compounds
- Pesticides and herbicides are not removed
The ion exchange method involves the use of resins in the form of beads that attach to the hard ions present in the water. This method is mainly used in water softeners. The ion exchange method tends to replace the hard ions in the water and make it softer by replacing them with positive and negatively charged ions present in the form of beads. Hard minerals such as magnesium and calcium along with other toxic materials and heavy metals are removed by utilizing these resin beads.
In the water softening process, swapping of ions takes place where negatively charged sodium ions present in resins bound to positive ions of calcium and magnesium. Calcium and magnesium usually get converted into less dangerous salts and are backwashed from the water. Ion exchange technology prevents limescale build-up and hence protects appliances such as washing machines and dishwashers.
- No hard water in the whole house
- Silky hair and glowing skin
- Soft vibrant clothes
- Usually gets installed at the Point of Entry
- Your silverware and glassware are cleaner and shinier.
- Time on cleaning is saved
- Can’t be used alone needs some pre-filters
- Alone not fit for drinking water filtration purpose
- Needs time for installation
- No protection from a microbial perspective
Treating drinking water with ultraviolet rays is another form of water purification. This method uses a UV light-emitting lamp in order to get rid of bacteria and viruses. The lamp is very effective in water sterilization from many disease-causing germs. The UV rays destroy the protein coating of germs and hence limit their ability to multiply.
But without the presence of other filters such as carbon and sediment filters, it is not of much usage because a specific odor and taste will still be there. Many other unnecessary and harmful chemicals cannot be removed along with a UV sterilizer. Many anti-microbial filters exist in the market as a replacement for UV filters as they have got more complaints.
- Remove germs and harmful microorganisms from water
- Good for immunity and health
- Need electricity in order to perform
- Unable to remove sediment, rust, dust, and other chemicals when used alone
- Require some other filters for effective filtration
- The UV lamp is expensive
- Need replacement yearly
Different filtration methods have different pros and cons. Many of them are used in combination to get the desired benefits. The above discussion has been intended to clarify the difference between various methods of water purification. Every method targets different impurities and each one has been designed to cater to different needs according to the budget. It doesn’t matter which method you choose for water purification but the purity and safety of drinking water are very pertinent to health.
Safe and pure water is healthy. Hydration is affected if water is impure and its appearance is bad in looks. Clean drinking water helps us in building immunity. It also brings improvement in the taste and aroma of food and prevents skin from allergies. As per the municipality, tap water is safe to consume but health is wealth so purified water is always more beneficial for health and well-being than impure water.