In a world where more efficient technologies are sought after to help remove the many contaminants in water sources, adsorption technology in water treatment is becoming more popular. This begs the question, what exactly is adsorption and how does it work? Water consumers are becoming more aware of the toxic elements that find their way into the water that they drink. The concern is justified owing to the higher number of pollutants that find their way from time to time into water sources. These include industrial products and pesticides among others.
Many organic wastes also have a high potential to get into the water sources, hence affecting the quality of several water supplies. The use of Activated Carbon especially for the domestic offers a promising way to sanitize water to a large extent. Lead has historically entered the piped water through the pipes fittings that are made from the metal, hence showing the high degree of contamination that could occur in drinking water.
How Adsorption in Water Treatment Works
Adsorption, simply put, is the removal of contaminants from water sources by the use of adsorption media. Adsorption has found wide applications in water treatment, including the processing of freshwater as well as the treatment of wastewater before disposal. One key aspect of adsorption is its ability to eliminate heavy metals from water sources depending on the adsorption medium used.
Materials used in carbon filtration
The most commonly used medium is activated carbon. The use of this material works such that a great surface area is provided that facilitates the adherence of the particles onto the surface of the carbon medium. The carbon is often used in its granular form but might also be used in powdered form in certain instances. While the most widely used filtration substance is activated carbon, other materials are also occasionally incorporated into the filtration devices to help increase the efficacy of adsorption and enhance the desired qualities of the products. One such material is silver nanoparticles.
Application of the process
Since the use of activated carbon is a fairly complex process considering that other simpler water treatment methods are available such as UV water treatment as well as desalination through reverse osmosis process, it must be applied in the most appropriate instances. In most industrial applications of adsorption in water treatment, water that is rich in organic matter is selected. Such water might often display unfavorable characteristics such as off-taste, dark colorations, and taste. While these qualities do not necessarily mean that the water is harmful and unsuitable for consumption, most consumers will often prefer water that is free of these characteristics. The removal of these qualities increases one’s satisfaction and experience in using the water for the various activities possible.
Several domestic and industrial use of water tends to require water free from the aforementioned characteristics. As a result, many products have been manufactured that employ the use of filters that incorporate activated carbon. For instance, these include both drinking water as well as that used in fish ponds.
Advantages and Disadvantages of Adsorption in Water Treatment
Advantages of Adsorption
- The process of adsorption helps to eliminate the microscopic elements that might be present in water. Hence, it not only removes the biodegradable components but can also remove the chemical pollutants.
- Activated carbon is not only suitable in the drinking water production units but can also find a wide application in the treatment of wastewater, and often provides impressive results.
- Activated carbon filtration is superior to chlorination, which is the more commonly used method of achieving filtration. This is because of the reaction of chlorine with the organic matter that might be present in the water. The reaction leads to the production of chloramines, which are harmful to the human body. Activated carbon removes virtually all the organic matter as well as other toxic compounds that might be present.
Disadvantages of adsorption
- One key demerit of the process is that the adsorption surfaces tend to attract the growth of microbiota. As a result, microorganisms such as bacteria might adhere to the surfaces after prolonged use. As a result, proper maintenance must be done to ensure that the treated water is safe and free from pollutants. In most instances, a complete replacement of the filter medium ought to be done to achieve this goal.
- The cost factor of producing adsorption media might also be prohibitive as compared to the other treatment methods. This is a result of the dwindling resources that are used in the manufacture of commercially viable adsorption products. The activated carbon, which is essential in the water treatment application, is especially decreasing in supply.
Useful Information on Adsorption in Water Treatment
Most municipal water sources are often chlorinated to achieve disinfection purposes. However, the chlorine compound in the water samples is greatly eliminated by the adsorption media. As a result, the water produced from the process might be readily susceptible to infection by microorganisms. Thus, it is more common for the water produces to be used as soon as possible after undergoing the adsorption process. However, it would be advisable that a disinfectant such as chlorine is added to the water if it is to be stored for some considerable duration before use.
Factors that influence the process
The two main factors that enhance the adsorption rate in any particular setup include the sizes of the pores of the adsorption medium and the surface area. To ensure that an enhanced adsorption rate is achieved, a high surface area is often necessary. Similarly, the rate also increases with the increase in pore sizes.
Conclusion
In conclusion, activated adsorption in water treatment processes can be a lifesaving method of water treatment. Its advantage of removing even the microscopic elements present in water ensures that clean and safe water is available for human consumption. The toxic elements such as lead and arsenic which are biologically fatal are eliminated. Furthermore, other taste and odor-inducing compounds that might affect one’s experience with the water, while not particularly being unsafe, are removed. It is also crucial to note that no single water treatment process offers complete removal of all substances in water. As a result, the combination of various technologies provides the ability to attain the best results.