The surface water or brackish water in the raw water not only contains dissolved salts, suspended solids and sediments such as particles, colloids, but also impurities such as pigments and peculiar smells, especially surface water, and most municipal water supplies also contain residual chlorine. In order to remove these impurities, we can use activated carbon as a filter bed to treat raw water. The activated carbon filter mainly uses its microporous adsorption function to absorb impurities such as colloids, pigments, odors and residual chlorine to achieve the effect of water purification and pollution interception. As long as the trapped impurities are removed after regular backwashing operations, the activated carbon filter can work again.