It is widely known that the water purification effect of activated carbon filters primarily depends on the quality of the activated carbon inside and its adsorption capability. The choice of activated carbon directly impacts the water treatment outcome. In daily production, there are mainly three types of activated carbon commonly used: granular activated carbon, which are black, cylindrical particles, available in solid and hollow forms. The hollow ones have one or several regular small holes inside the cylindrical carbon, offering good adsorption for volatile organic compounds in water bodies. Powdered activated carbon, where over 90% of the carbon particles are smaller than 0.175mm, is also known as powdered carbon and features a well-developed mesoporous structure with a large adsorption capacity. Granular activated carbon, appearing as black, irregular particles, typically has a particle size greater than 0.175mm, with a well-developed pore structure and good adsorption properties.

Three types of activated carbon each have their unique strengths. When dealing with the same water quality, the primary consideration is the adsorption capacity. Generally, the smaller the particle size of the activated carbon, the larger the filtration area, and a larger filtration area results in better adsorption. Following this logic, it would seem that powdered activated carbon has a larger filtration area and better absorption. However, in practical applications, it's essential to weigh the pros and cons of the three types of activated carbon. While powdered activated carbon offers excellent adsorption, its small particle size makes it prone to being washed away with water, resulting in poor controllability and a limited scope of application. On the other hand, using granular activated carbon in an activated carbon filter is more effective, as the granular shape is less likely to move and block the water flow, providing good adsorption and ease of handling.