The Main Influencing Factor of Activated Carbon Water Treatment—the Properties of Activated Carbon

Because the adsorption process and working principle involved in activated carbon water treatment are quite complex, many factors influence it. These mainly relate to the properties of the activated carbon, the properties of the pollutants in the water, the process principle of activated carbon treatment, and the selected operating parameters and conditions.

Properties of Activated Carbon

Since adsorption occurs on the surface of the adsorbent, the specific surface area of the adsorbent is one of the important factors affecting adsorption; the larger the specific surface area, the better the adsorption performance.

Since the adsorption process can be considered as three stages, internal diffusion has a significant impact on the adsorption rate; therefore, the micropore distribution of activated carbon is another important factor affecting adsorption.

In addition, the surface chemical properties, polarity, and charge of activated carbon also affect the adsorption effect.

Activated carbon used for water treatment should meet three requirements: large adsorption capacity, fast adsorption rate, and good mechanical strength. The adsorption capacity of activated carbon, apart from other external conditions, is mainly related to its specific surface area; a larger specific surface area means more micropores, allowing more adsorbate to be adsorbed onto the pore walls. The adsorption rate is mainly related to particle size and pore distribution. Activated carbon used for water treatment requires well-developed mesopores (radius 20~1000 Å) to facilitate the diffusion of adsorbates into the micropores. The smaller the particle size of activated carbon, the faster the adsorption rate, but the head loss will increase. Generally, a particle size of 8~30 mesh is more suitable. The mechanical abrasion resistance of activated carbon directly affects its service life.