Popular Filtration Technologies used in Water purifier

There are many types of home water purification system (or water filter) available in the market, and each of them utilizes different water purification technologies to produce cleaner, safer and better water for you and your family.

It’s open facts that bottled water is more costly and contribute to environmental pollution.

So, as a smart consumer, the best option is to drink filtered water from your home’s water filtration system.

The operating cost of a home water purifier is much lower compared to buying bottled drinking water.

Yes, the initial investment to purchase the water purifier might seems to be high, but you will definitely see the significant saving in a few months down the road.

Next, the issue with bottled water is not really just about the cost, but their plastic bottles that are hard to recycle, which are causing serious pollution to our lovely earth!

If you want to contribute your little part to our environment, get a water purifier at home and get away from bottled water as soon as possible.

Why waste your petrol, time and energy to shop at the grocery store for bottled water or wait for the water bottle delivery guy, when you can have a clean, safe and pure water right from your water tap by installing a water purifier.

It’s open facts that bottled water is more costly and contribute to environmental pollution.

So, as a smart consumer, the best option is to drink filtered water from your home’s water filtration system.

Here are the 7 common types of water filtration system at home, each of them with different pros and cons:

1) Sediment filtration:

Sediment filtration is the most common and basic water filtration system that is widely used across the world in home.

It works very well in removing sediments like rust, sand, dust, silt and other large particles in water.

The micron rating indicates the size of the pores of the filter, lower microns mean stronger filtration (able to filter out smaller size contaminants) but provide a slower water flow rate.

It’s can be used alone as a point of entry (POE) whole house filtration solution or use in conjunction with other filters to provide greater filtration.

A sediment filter is commonly employed as a pre-filter in other water filtration system at home like Activated Carbon filter, UV, UF, Reverse Osmosis and Nano positive membrane filtration system to protect the rest filters from getting clogged by large particles.

The replacement frequency or life of the sediment filter will depend on the feed water quality.

The Advantages of Sediment Filtration:

• Low cost
• Effective against sediments and large particles in water
• Simple replacement process
• Wide range of microns rating available

The Disadvantages of Sediment Filtration:

• Cannot remove chemicals and contaminants smaller than 1 micron
• Need to combine with other filters to provide safe and tasty drinking water
• Not very popular and effective as a standalone purification technology.

2) Activated Carbon Block

The Activated Carbon Block  is composed of fine carbon powder that held together and remains static by a binding agent.

It’s very effective in removing Chlorine taste and odor, chemicals, and more contaminants in water.

Also, the Activated Carbon Block is able to reduce contaminants like lead, volatile organic compounds (VOCs), and microscopic cysts in water.

It also has high resistance against bacterial growth due to the tiny pore size.

The Advantages of Activated Carbon Block Filtration:

• Affordable price and high value (performance-to-cost ratio)
• Very effective in removing Chlorine taste and odor
• Good water flow rate
• Minimal pH level change
• No chemical additives

The Disadvantages of Activated Carbon Block Filtration:

• Can’t achieve a very high water flow rate
• Require a separate sediment filter (for large sediments) to prolong its lifespan and work efficiently
• Cannot remove viruses
• Cannot remove excess minerals and dissolved solids

3) Granular Activated Carbon (GAC) Filtration

Perform a similar function as the activated carbon block like getting rid of chlorine taste and odor.

The Granular Activated Carbon contains loose carbon granules that are larger than carbon block powder, result in weaker contaminants adsorption but higher water filtration rate compared to carbon block.

It can be used as a pre-filter to protect the carbon block filter from larger particles and achieve greater removal for Chlorine taste and odor, chemicals, and other contaminants in your tap water.

The high water flow rate makes it suitable to be used for high-flow and low-intensity filtration, such as point of entry (POE) whole house filtration system, point of use (POU) inline water filter and as a part of a multi-stage filtration system.

The Advantages of Granular Activated Carbon Filtration:

• High water filtration and flow rate
• Good contaminants filtration capability
• Effective in getting rid of Chlorine taste and odor
• Minimal pH level change
• Easily to be used in conjunction with other filtration technologies for greater filtration

The Disadvantages of Granular Activated Carbon Filtration:

• Weaker filtration especially against smaller size contaminants
• The lower density of its carbon granules may cause bacterial growth
• Cannot remove viruses
• Cannot remove excess minerals and dissolved solids

4) Reverse Osmosis (RO) Membrane Filtration

Reverse Osmosis is a filtration technology that utilizes a semipermeable membrane (or called RO membrane) to separate inorganic contaminants from water and produce the clean drinking water.

It’s capable to remove the majority of contaminants (up to 99%, including minerals) from water except for most soluble volatile organic compounds (VOCs), some pesticides, solvents, and chlorine.

Of course, behind the highly intensive filtration does come with some costs like a higher price, slow filtration rate, and produce a large amount of brine (usually 3:1 wastewater to filtered water ratio).

And because of its slow water filtration rate, most of the reverse osmosis filtration system comes with a pressurized tank in under the sink models and storage tank in counter top models to store the filtered water to compensate for the slower purification rate.

The RO membrane is vulnerable to chlorine, so activated carbon filter is also used in a Reverse Osmosis filtration system as a pre-filter to remove chlorine.

The Advantages of Reverse Osmosis Filtration:

• Offer the strongest filtration against the majority of contaminants found in water
• Able to remove or significantly reduce dissolved solids, iron, calcium, lead, cysts, mercury, bacteria, and more contaminants
• Low total dissolved solids (TDS) value of filtered water

The Disadvantages of Reverse Osmosis Filtration:

• Does not remove chlorine, some pesticides and organic chemicals, solvents, and volatile organic compounds (VOCs)
• Produce a large amount of brine (wastewater) during the filtration process
• Slow water filtration rate
• Remove essential minerals in water and lower down water pH level
• Require a water tank for filtered water storage
• Cannot be used alone to treat chlorinated tap water
• Higher cost

5) Ultraviolet (UV) Disinfection

In water treatment, ultraviolet technology is often used to kill microorganisms like viruses, Cryptosporidium, protozoa, Cysts, E.coli, Coliforms and bacteria. The UV wavelength scrambles the DNA of living organisms in the water, so they can no longer reproduce and make you sick.

The UV ray from the ultraviolet lamp will damage and destroy 99.99% of microbiological contaminants in water that may cause illness, giving you peace of mind in consuming your daily drinking water.

However, a UV lamp is always additional protection and not a water filter, so you still need a water filtration system to filter out contaminants and chemicals in the water.

The Advantages of Ultraviolet (UV) Disinfection:

• Able to kill 99.99% of harmful microorganisms in water
• The quick and reliable disinfection process
• Chemical-free solution for microorganisms

The Disadvantages of Ultraviolet (UV) Disinfection:

• Rely on electricity supply to work
• Only remove microorganisms in water
• The residual particles in the water will reduce the efficiency in destroying microorganisms
• Require a pre-filter to block out particles and impurities in water
• Require frequent monitor for UV lamp and light tube

6) Ultrafiltration technology

Ultrafiltration technology makes use of hydrostatic pressure to force the water flowing through a submicron semipermeable UF membrane (usually made from 0.01 to 0.5 microns hollow fiber) to filter out most of the contaminants in water.

The small microns rating UF membrane (0.01 to 0.02 microns) is also capable to remove microscopic contaminants like parasites, bacteria, and viruses while retaining the essential minerals.

As the UF membrane cannot filter out dissolved solids in water, it’s only suitable to treat water with a low concentration of total dissolved solids (TDS).

The hollow fiber UF membrane has high resistance against chemicals like Chlorine, allow it to filter municipality treated water without rely on the activated carbon as a prefilter.

But for drinking water treatment, ultrafiltration is usually combined with other filtration technologies like sediment, activated carbon, to cover its drawbacks and to cover others’ drawbacks in order to work more effectively.

The Advantages of Ultrafiltration (UF):

• Reliably strong filtration capability down to 0.01 microns
• Effectively remove the majority of contaminants in water including parasites, viruses, bacteria, turbidity, and most pathogenic organisms
• Retain essential minerals in the water
• Fast water flow rate
• Can operate under low water pressure

The Disadvantages of Ultrafiltration (UF):

• Cannot remove Chlorine taste and odor.
• Cannot remove dissolved solids like salts, fluoride, and more
• Not effective against organics contaminants like cysts and volatile organic compounds (VOCs)

7) Nano positive filter 

This is a recent addition in domestic water filtration technology and is gaining popularity. As an electropositive charged porous water treatment filter, This is a special advanced filter that maximizes the removal efficiency of the filter by adding an electrochemical mechanism (electrostatic force) without depending on the physical mechanism (pore size) of the filter.

Electrostatic force is applied to selectively adsorb and remove various bacteria, fine particles, heavy metals, viruses to provide beneficial water.

This filter can be confirmed that it is coated with positively charged polymer resin on the surface of the fiber material filter media (PET), and it has an excellent effect to remove micro colloid material with anion in water and microorganisms such as viruses and bacteria.

It removes minute particles, germs (pseudomonas aeruginosa, colon bacillus, staphylococcus aureus), viruses (Norovirus), and heavy metals (lead, iron, aluminium)

The Advantages of Nano positive membrane:

• Effectively remove the majority of contaminants in water including viruses, bacteria and heavy metals (mercury, lead, iron, aluminium)
• Retain essential minerals in the water
• Zero water wastage
• Minimal pH level change
• Fast water flow rate
• Can operate under low water pressure

The Disadvantages of Nano positive membrane

• Require a pre-filter to block out particles and impurities in water
• Not suitable for water > 500 ppm TDS
• Cannot be used standalone to purify the water