KNOW YOUR WATER

Water filters for municipal water use two different techniques to remove impurities. The first technique is physical or barrier filtration, which strains water to remove larger impurities. In other words, a physical filter can be compared to a sieve. Physical filtration will typically start at fine particle filtration, followed by micro, ultra and nano filtration. The ultimate physical filtration to remove impurities will be Reverse Osmosis (RO) technology.

RO water treatment results in too low TDS levels, which causes a flat taste and is on the acidic side of the pH spectrum. This is undesirable for many end consumers. However, remineralising of RO water is gaining immense popularity, and highly advisable from a health perspective.
Blue Water Solutions will not recommend the use of RO technology to treat municipal water primarily due to this technology’s water wastage problem.
The second technique is chemical filtration, where water is passed through an active material that removes impurities chemically by way of redox reaction. Redox is short for oxidation-reduction, which is a chemical reaction where electrons are transferred between molecules. In some cases, such as free chlorine, this transfer results in the formation of benign substances, such as chloride in this case, which then passes through the filter. In a similar way, copper, lead, mercury, and other heavy metals react to plate out onto the medium’s surface effectively being removed from the water supply. Redox reaction media, such as KDF and Active ceramics is very effective in significantly removing inorganic water-soluble heavy metals.

Physical or barrier filtration is the basis for conventional filtration. This refers to a media that’s used as a barrier to filter water through. The micron filtration of this media will determine what is caught within the barrier when the water is passed through it.

• Microfiltration refers to all filtration above 0.1 micron, where 1 micron is equal to a millionth of a metre or a thousandth of a millimetre. The smallest particle visible to the human eye is 40 microns and about 1 to 10 microns in length and from 0.2 to 1 micron in width.
• Ultrafiltration is a membrane type system that removes small colloids and large molecules from solutions. Ultrafiltration removes particles in size range between 0.002 to 0.1 micron range. Viruses are 0.004 to 0.1 microns in size, which is about 100 times smaller than bacteria.
• Nanofiltration is a membrane process that treats water between reverse osmosis and ultrafiltration the filtration/separation spectrum, but we currently do not specialise in this technology.  Alternative approaches will be the use of Reverse Osmosis and Redox Reaction media.
• Reverse osmosis is a process for the removal of dissolved ions from water, in which pressure is used to force the water through a semi-permeable membrane, which will transmit the water but reject most other suspended and dissolved materials. It is called reverse osmosis because mechanical pressure is used to force the water to flow in the direction that is the reverse of natural osmosis, namely from the dilute to the concentrated solution.

Active ceramics contains a mixture of elements such as Platinum, Silver and Copper. When the ceramic spheres rub together, these elements create a redox reaction thereby inhibiting the growth of bacteria. KDF55 uses Copper and Zinc to create the same reaction, but because the elements used by active ceramics are further apart on the periodic table, the redox reaction for active ceramics is known to be up to 20 times stronger than using Copper and Zinc.

There are obvious differences between point-of-use (POU) and point-of-entry (POE) water treatment products. For example, POE treats water for the whole house, or a majority of the house, while POU treats water for a single tap or multiple taps, but not a majority of the house.
The primary reason to install a water filtration or purification system is to get rid of the contaminants that are present in tap water and get ‘safe’ water. Although chlorine is widely used as a disinfectant for drinking water, chlorine forms many by-products, including trihalomethanes (THM) and haloacetic acids (HAAs). Formed when ammonia is added to chlorine, Chloramines are also used to treat drinking water as it provides longer-lasting disinfection as the as the water moves through pipes to consumers. Chloramine forms a significantly lower amount of THMs and HAAs, but also forms N-nitrosodimethylamine (NDMA).

At elevated levels, THMs have been associated with negative health effects such as cancer and adverse reproductive outcomes. For the volatile THMs, approximately equal contributions to total exposure come from four areas: ingestion of drinking-water, inhalation of indoor air largely due to volatilization from drinking-water, inhalation and dermal exposure during showering or bathing and ingestion of food, with all but food exposure arising primarily from drinking-water. THMs can be reduced by adsorption with an activated carbon filter.

NDMA can also occur in drinking-water from several industrial processes and is also a contaminant of certain pesticides. NDMA has been classified as carcinogenic to humans. NDMA is not removable by even reverse osmosis and requires UV irradiation.

To reduce the risk to you and your family, consider BOTH a POE and POU water filtration or purification systems.

Activated carbon filter manufacturers will provide you with a guideline for how often you should change your carbon filter. Although only a starting point, your usage habits, water quality fluctuations and presence of purification media such as KDF (extend the life of carbon) will determine the lifespan of your water filter cartridge/s.

The process to remove contaminants from water using activated carbon is called adsorption (not to be confused with absorption). When carbon adsorbs contaminants like chlorine, the molecules, ions or atoms from the chlorine collect like a film, called adsorbate, on the carbon. There is only so much space for the adsorbate to collect on the carbon and once saturated, the carbon is no longer effectively and may even release certain pollutants in favour of other ones.

Another important factor is back contamination from you’re your systems faucet. Activated carbon media is not recommended to reduce microbial contaminants. If anything, carbon particles are prone to shedding heterotrophic plate count bacteria and other colonizing microbes into the water. Even faecal coliforms and other opportunistic bacterial pathogens are capable of colonising carbon particles.

As a guideline and for all practical purposes most countertop-top or under-counter carbon type filters should be replaced on at least an ANNUAL BASIS.

For every 1 litre RO water you drink, you can waste up to 7 litres off tap water…let that sink in for a moment!

An RO creates drinking water by forcing tap water through a semi-permeable membrane to fill a 9lt water (capacity) tank. As the tank fills, increasingly more tap water is wasted as a result of the increase in back pressure. As this back pressure increases, less water is able to pass through the membrane and more water is flushed down the drain.

So simply stated, when an RO fills an empty 9lt (water capacity) holding tank it wastes +- 45lt of tap water, but when you draw water continuously throughout the day from a full tank, an RO will waste a lot more water to top up its tank.

Let’s say a typical household uses 1lt at a time and a total of 5lt of water per day. After every 1lt of water drawn from the tank, the RO will begin to top-up its tank. To fight the back pressure to fill a 90% full tank will waste 85% + of the tap water used. As a result you ca waste up to 7lt of water to refill the 1lt use, depending on age of membrane and tank pressure. At this rate your household will waste 35lt of water per day or almost 13,000lt of water per year.