Water is essential to life, and clean, safe drinking water is essential to good health. Unfortunately, many water sources contain impurities such as contaminants, chemicals and micro-organisms, so water has to be treated to make it safe to drink.
Activated carbon for water treatment has become one of the most popular treatment methods. But is it really the best option? Here we explain activated carbon and compare it with other water treatment methods in simple terms.
What is activated carbon?
Activated carbon is a form of carbon treated to create an extensive network of tiny pores. These pores provide a very large surface area, allowing activated carbon to adsorb impurities from water. Adsorption is the process by which contaminants attach to the surface of the activated carbon, which traps them and removes them from the water.
Other water treatment methods
Filtration
Filtration is a common water treatment method in which water passes through a physical barrier that removes larger particles, sediment and some micro-organisms. It improves clarity and removes visible impurities, but may not be enough to remove certain dissolved contaminants.
Chlorination
Chlorination is a chemical method in which chlorine is added to water to disinfect it and kill harmful micro-organisms such as bacteria and viruses. Although effective for disinfection, chlorination can also produce by-products such as trihalomethanes, which can be harmful at high concentrations.
Reverse osmosis (RO)
Reverse osmosis removes dissolved salts, minerals and certain contaminants from water using a semi-permeable membrane. It is very effective at producing purified water, but it produces a reject stream and also removes some beneficial minerals.
Ultraviolet (UV) disinfection
UV disinfection exposes water to ultraviolet light, which damages the DNA of micro-organisms and prevents them from reproducing. It is effective against bacteria and viruses, but does not remove other contaminants or particles.
Ion exchange
In ion exchange, ions in the water are exchanged for ions on a resin to remove certain dissolved contaminants, such as the minerals that cause hardness. It is effective for specific purposes but does not target all contaminants.
Advantages of activated carbon
Activated carbon has several advantages that make it a popular choice for water treatment:
- Versatility: it removes many contaminants, including organic compounds, chlorine and many chemicals.
- Better taste and odour: it removes unpleasant tastes and odours.
- Long service life: activated carbon filters can last a long time before they need replacing.
- Cost-effective: it is usually more affordable than advanced treatment methods such as reverse osmosis.
- Environmentally friendly: it does not produce harmful by-products during treatment.
When is activated carbon not enough?
Although activated carbon is excellent for certain applications, it has its limitations:
- Limited capacity: it becomes saturated with impurities and loses effectiveness over time, so it needs regular replacement or regeneration.
- Specific contaminants: it may not be the best option for removing certain dissolved minerals or heavy metals.
- Micro-organisms: it does not effectively remove bacteria or viruses, so it needs to be combined with disinfection.
Combining treatment methods for the best results
In many cases, a combination of treatment methods gives the best overall results, as the strengths of each technology make up for the limitations of the others. For example:
Activated carbon and UV disinfection: using activated carbon to remove organic compounds and chemicals before UV disinfection improves the overall effectiveness of microbial inactivation.
Activated carbon and reverse osmosis: activated carbon as a pre-filter for reverse osmosis extends membrane life by removing chlorine, and can also remove some contaminants that RO alone does not deal with well.
Chlorination and filtration: combining chlorination with filtration deals with microbial contamination and removes larger particles.
The importance of water testing and professional advice
Water quality varies considerably with location, source and local environmental factors, so water testing is essential to identify the specific contaminants present. Seek advice from water treatment professionals or the local health authorities on potential risks and recommended treatment methods.
The best option: it depends
The best water treatment method depends on several factors, including the contaminants present, the level of treatment required, the budget and the available technology. Often, a combination of methods is the most effective approach.
Key points
KEIKEN offers tailored water treatment solutions with activated carbon and other technologies for homes, businesses and communities. Contact us to discuss your needs.
