The ideal Absorbents for Water Purification and Why?

Various purification techniques are used to do water purification and water treatment. Techniques for purification also vary depending on the sort of contaminants and the water’s quality. Distillation, ion exchange, reverse osmosis, adsorption, UV radiation, and other techniques are examples of many types of purifying procedures. These treatments address several types of water pollutants.

Adsorption is one of the most often employed water purification techniques among them. It is a crucial method applied in water filtration systems.

What is adsorption?

Adsorption is a technique for removing minute particles or dissolved molecules from water by utilising adsorbents like activated carbon. In this procedure, the activated carbon functions as a magnet, drawing in tiny particles and binding them to the absorbent.

Small particles that cannot be retrieved during mechanical filtration can be removed using this method. They are too small or have dissolved in the water, making them challenging to extract with mechanical filtering.

However, adsorption is often confused with another type of filtration called absorption. Both are different because in the absorption process the particles seep into the substance.

Carbon adsorption, as it is commonly known, is one of the most common methods used in water purifiers. The activated carbon filters not only remove tiny particles but also remove bad odors or tastes in the drinking water. However, activated carbon can’t treat TDS in water or soften the hard water. Hence, carbon filters are part of the pre-RO and post-RO purification stages.

What are Pre-RO and Post-RO Stage?

RO purification is a multi-stage process where different types of impurities are removed at each stage. Hence, RO purification is broadly divided into the Pre-RO stage, RO purification stage, and Post-RO purification stage.

Pre-Carbon Filters:

The pre-RO stage consists of sediment filters and carbon filters. First, the impure water passes through the sediment filter which removes particulate matter and other suspended particles. The next stage is the carbon filter.

Pre-Carbon Filters remove VOCs and chlorine present in the water. By removing substances like Chlorine, carbon filters improve the lifespan of the RO membrane because Chlorine can damage the pores in the semipermeable membrane.

RO Purification

The next stage will be reverse osmosis where the TDS, heavy metals, minerals, chemicals, and microorganisms like viruses and bacteria are removed. Since it removes most types of contaminants, the best UV water purifier is always in demand. After the RO process is completed, the next stage is Post-Carbon Filter.

Post-Carbon Filter

It is the last stage in the multi-stage purification process, the Post-Carbon filter will act as a polisher. It removes any remaining particles, enhances the taste, and removes the bad odor in drinking water. Activated carbon is one of the best adsorbents used in water purification.

After all stages of purification including UV which is also a part of the post-RO stage, the 100% purified and safe drinking water is collected in the tank ready for use.


Leveraging activated carbon in water purification has followed for ages. It is not entirely new technology. However, the technology is slightly modified and water is filtered through carbon filters which mainly uses activated carbon to carry out the purification process.

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