The unique, porous structure and vast surface area of activated carbon, combined with attraction forces, allows activated carbon to capture and hold various types of materials onto its surface. Activated carbon comes in many forms and varieties. It is produced by processing a carbonaceous material, most often coal, wood, or coconut husks, in a high temperature environment (such as a rotary kiln[5]) in order to activate the carbon and create the highly porous surface structure.
Activated carbon is one of the most used products in the water treatment industry. It is extremely porous with a large surface area, which makes it an efficient adsorbent material. Activated carbon belongs to group of porous carbon materials that have high adsorption capacity and reactivation capability. Many substances are used as a base material to produce AC. The most common of those used in water purification are coconut shell, wood, anthracite coal and peat.
Various forms of activated carbon exist, each offering different material characteristics that make it ideally suited for specific applications. As such, manufacturers offer a wide array of activated carbon products. Depending on the application, activated carbon may be used in powdered, granular, extruded, or even liquid form. It may be used alone, or combined with different technologies, such as UV disinfection. Water treatment systems typically employ either granular or powdered activated carbon, with granular activated carbon (GAC) from bituminous coal being the most commonly utilized form. Coconut shell has emerged as one of the best forms of activated carbon for water filtration system needs. Coconut shell- based activated carbons are micro-pores. These small pores match the size of contaminant molecules in drinking water and thus are very effective in trapping them. Coconuts are a renewable resource and readily available throughout the year. They grow in large numbers and can be preserved for a long time.
Water may contain contaminants which can affect health and quality of life. Water intended for human consumption must be free from organisms and from concentrations of chemical substances that may be hazardous to health. The water we drink daily must be free from any pollution. There are two types of drinking waters: pure water and safe water. It is important to distinguish between these two types of drinking waters.
Pure water may be defined as water that is free of extraneous substances whether harmless or not. From a practical standpoint, however, pure water is hard to produce, even with current sophisticated equipment. On the other hand, safe water is water that is not likely to cause undesirable or adverse effects. Safe water may contain some contaminants but these contaminants will not cause any risks or adverse health effects in humans. The contaminants must be in an acceptable range.
For example, chlorination is used to disinfect water. This process, however, introduces trihalomethanes (THMs) into the finished product. THMs pose potential health risks. Long- term drinking of chlorinated water appears to increase a risk of developing bladder cancer as much as 80 percent, according to a study published in the journal of the National Cancer Institute (St. Paul Dispatch & Pioneer Press, 1987).
As the population of the world increases and demands for using safe water increases more than ever before, it will be of great concern in the near future that water treatment facilities be more effective. On the other hand, water supplies to households are still threatened by contaminants like chemicals and microorganisms.
Activated carbon has been used as a water filtering medium for purification of drinking water for many years. It is widely used for the removal of contaminants in water due to its high capacity for adsorption of such compounds, resulting from their large surface area and porosity. Activated carbons have varied surface characteristics and pore size distribution, characteristics that play an important role in adsorption of contaminants in water.
Post time: Mar-26-2022