We offer Filtering Solutions
Water, which covers 71% of the Earth’s surface, is a crucial substance that plays a vital role in various fields such as agriculture, science, medical, transportation, heating, recreation, food processing, and washing. It is also a fundamental component of the human body, with as much as 75% of our body containing it. Among these applications, drinking water is perhaps the most important one.
Most of us obtain drinking water from treated municipal sources, which are generally safe to consume. However, the water may contain unpleasant tastes and odors due to the use of chemicals like chlorine for disinfection purposes. Moreover, depending on the location, mains water can lead to the formation of limescale deposits, which can clog pipes and damage appliances. Water filtration is a potential solution to these issues, as well as many other common water problems. But how exactly do water filters work?
The basic idea of mechanical filtration is to physically remove sediment, dirt or any particles in the water using a barrier. Mechanical filters can be anything from a basic mesh that filters out large debris to a ceramic filter which has an extremely complex pore structure for ultra-fine filtration of pathogenic organisms. A filter that utilises mechanical filtration will usually be given a micron rating which indicates how effective the filters are in terms of the size of the particles it is capable of removing. Common ratings you might see include:
5 micron – Will remove most particles visible to the naked eye.
1 micron – Will remove particles which are too small to see without a microscope.
0.5 micron – Will remove cysts (giardia and cryptosporidium).
Absorption in water filters is most commonly carried out by carbon, which is highly effective at capturing water-borne contaminants. The reason carbon absorbs contaminants so readily is that it has a huge internal surface which is jam packed with nooks and crannies that can trap chemical impurities such as chlorine.
Most common domestic filters contain granular activated carbon (GAC) which reduces unwanted tastes and odours by absorption. More expensive filters use carbon block elements which are generally more effective and usually carry a micron rating for particle removal.
A variety of different substances can be used to make carbon for filters including wood and coconut shell, with coconut shell filters being more effective but also more expensive.
Sequestration is the action of chemically isolating a substance. Food grade polyphosphate is commonly used in scale inhibiting filters to sequester the calcium and magnesium minerals which cause limescale and corrosion. However, polyphosphate is generally only introduced in very small amounts and it only inhibits scale rather than eradicating it. This means that polyphosphate does not soften the water but instead works to keep the minerals within the solution, preventing them forming as scale on any surfaces they come into contact with.
Due to the hard minerals still being present in the water, scale inhibition isn’t suitable for all applications. Instead, water softening using a process such as ion exchange is usually recommended in water areas with alkalinity levels of 180ppm or more (very hard water) and applications where water is kept at a constant temperature of 95°C or more.
Ion exchange is a process used to soften hard water by exchanging the magnesium and calcium ions found in hard water with other ions such as sodium or hydrogen ions. Unlike scale inhibition, ion exchange physically removes the hard minerals, reducing limescale and making water suitable for applications where it is kept at a constant high temperature e.g. in commercial coffee machines.
Ion exchange is most commonly carried out using an ion exchange resin which normally comes in the form of small beads. A similar type of resin is used in some Water Softeners and in the case of a water softener the resin utilises sodium ions which need to be periodically recharged to prevent the resin becoming ineffective. As water filters are usually sealed units you would simply replace the filter with a new one though it should be noted that
Calcium Treatment Units (CTUs) can be returned to the supplier and regenerated.
Resins that utilise sodium ions aren’t usually used in drinking water filters as the amount of salt (sodium) that can be present in drinking water is legally limited to 200 milligrams/litre. As sodium ion exchange increases salt levels, a hydrogen based ion exchange resin is the preferred option for filters.
Reverse osmosis (RO) is the process of removing dissolved inorganic solids (such as magnesium and calcium ions) from water by forcing it through a semipermeable membrane under pressure so that the water passes through but most of the contaminants are left behind.
Reverse osmosis is a highly effective way of purifying water and is usually combined with a number of other filters such as a mechanical (sediment) filter and an absorption (activated carbon) filter in order to return water with few contaminants remaining.
Reverse osmosis systems use water pressure to force water through the membrane so it uses no electricity, though a certain amount of waste water is produced that has to be sent to the drain. The extra filters involved in multi-stage water filtration can make a reverse osmosis unit more expensive than other filtration methods but in applications where 99.9% pure water is required, RO offers the finest level of filtration available as is increasingly being used to treat water made for Coffee
Filtering
Problem 1: Hard Water
Hard water is a common issue that arises when water contains high levels of dissolved minerals such as calcium and magnesium. While these minerals are not harmful to human health, they can cause a range of problems in daily life.
One issue associated with hard water is that it can leave mineral deposits, commonly known as limescale, on surfaces such as sinks, bathtubs, and appliances. Over time, limescale buildup can lead to clogs in pipes and damage to water-using appliances like coffee makers, dishwashers, and washing machines, reducing their lifespan and efficiency. Additionally, hard water can make it more difficult to achieve a lather with soap, which can lead to soap scum buildup on skin, hair, and clothing.
Fortunately, there are several ways to combat hard water. One common solution is to install a water softener, which works by removing the minerals that cause hardness and replacing them with sodium ions through a process called ion exchange. Another option is to use a chemical treatment that sequesters the dissolved minerals, preventing them from forming limescale. Alternatively, electronic water conditioners can be used, which produce electromagnetic fields that alter the minerals’ behavior, preventing them from forming deposits and limescale.
Filtering
Problem 2: Taste
Improper water filtering can have a significant impact on the taste and quality of water. If the filter is not maintained correctly, it can become clogged with debris and contaminants, leading to a reduction in water flow and a decrease in the filter’s effectiveness. In such cases, the water may develop an unpleasant taste or odor, and it may even contain harmful substances that can pose a risk to human health.
One of the most common causes of bad-tasting water is the presence of chlorine or chloramines, which are commonly used in water treatment to disinfect the water and kill bacteria. While these chemicals are essential for water safety, they can leave a strong taste and odor in the water. Additionally, impurities such as bacteria, viruses, sediment, and organic matter can also impact the water’s taste and quality.
To solve these issues, it is essential to properly maintain and replace the water filter on a regular basis, as recommended by the manufacturer. Depending on the type of filter, this may involve cleaning the filter media or replacing the filter cartridge. It is also important to select the appropriate filter for the specific water source, as different filters are designed to target different types of contaminants. Additionally, some filters are specifically designed to address taste and odor issues by utilizing activated carbon, which removes impurities and improves the water’s overall taste and smell.
Filtering
Problem 3: Maintenance and Replacement
Replacing water filters is an essential aspect of maintaining water quality and ensuring that the water is safe to use and drink. However, many people put off replacing their water filters due to a variety of reasons.
One common reason people put off replacing their water filters is a lack of awareness or understanding of how often filters need to be replaced. Some people may assume that their filter will last indefinitely or simply forget to replace it, leading to a decrease in the filter’s effectiveness and an increase in impurities in the water.
It is crucial to have a professional replace water filters regularly to ensure that the filter is being replaced at the appropriate interval and that the filter is installed and functioning correctly. Professionals have the knowledge and tools needed to assess the water quality and recommend the best filter for the specific water source. They can also ensure that the filter is installed correctly and provide guidance on proper maintenance and replacement. By having a professional replace water filters, people can ensure that their water is safe, clean, and free of harmful contaminants.
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