Wastewater Treatment Systems-Carbon Filter

The presence of organic matter in water, all of which have a carbon structure, has a negative effect on its quality and greatly affects its turbidity, odor and taste. Carbon filter or activated carbon filter is active in reaction with organic matter due to the presence of activated carbon and immediately absorbs organic matter and causes a large amount of contaminants in the water to be removed. The instantaneous bonding of organic matter in the water with the outer surfaces of the activated carbon filter is the main reason for the absorption of organic matter by these filters. The general structure of water purifiers that operate with activated carbon filters includes a tank, inlet valve, silica, activated carbon and outlet valve. The body of the activated carbon filter is often made of steel, carbon steel with epoxy paint or FRP. Water with a pH at the neutral level enters the tank through the inlet valve and loses organic matter by passing through the carbon layers, and finally by passing through the suspended silica, the suspended solids are removed and the water is clear and odorless, tasteless and colorless. It is transferred from the outlet valve to the outside of the tank. The important point in making carbon filters is that in addition to activated carbon, these filters also use silica, which has a very important role in absorbing suspended solids in water. First, a layer of silica is placed and covered with carbon. The passage of suspended particles and the adsorption of organic matter by carbon filters over time causes a jelly layer to form on it, which drastically reduces the performance of the filter. Therefore, it is necessary to clean and regenerate the filter by various methods such as backwashing with backwash. Types of carbon filters Carbon or activated carbon filters are divided into different groups according to the type of carbon and its particle size, which are: · Granular Activated Carbon Filter · Powdered Active Carbon Filter · Active Carbon Filter Block Granular carbon filter (GAC), also known as sand carbon filter, as its name implies, treats water with small grains the size of carbon sand. The contact surface of water with carbon sand grains is less than its powder type and therefore has a lower efficiency. Powdered activated carbon filter or PAC has the highest contact surface with water droplets and has the ability to absorb organic matter and remove the color, odor and taste of water in it more than other types. Block carbon filters have less adsorption power due to the large size and dimensions of the carbon, but can work better in removing suspended matter in the water than the previous two. In general, GAC and PAC are often used in water purifiers. Activated carbon is made from wood, coal and coconut husk, which is produced in various ways such as thermal activation and chemical activation. Due to the excellent absorption of carbon produced by the coconut husk, this type of carbon is often used for water treatment systems with carbon filters. It should be noted, however, that activated carbon from coconut husk is more expensive than other filters.