What is an activated carbon filter?

In the water quality pretreatment system, the activated carbon filter adsorbs residual chlorine that cannot be removed by the preceding filtration stage, thereby preventing oxidation and degradation of the downstream reverse osmosis membrane. It also adsorbs trace amounts of small-molecule organic compounds and other contaminants that may leak from upstream stages, exhibiting significant removal efficiency for odors, colloids, pigments, heavy metal ions, and other impurities in the water, while simultaneously reducing COD. Furthermore, it can lower the SDI of the feed water entering the RO system, ensuring compliance with SDI requirements.

What is the product description of the activated carbon filter?

An activated carbon filter pressure vessel is a pressurized container internally packed with activated carbon, and the filtration process is carried out by passing water through the carbon bed. The activated carbon particles that make up the bed possess an extensive network of micropores and a very large specific surface area, giving them strong physical adsorption capacity. As water flows through the bed, organic contaminants are effectively adsorbed onto the activated carbon. In addition, the amorphous surface of the activated carbon contains oxygen-containing functional groups, which further enhance the adsorption of organic pollutants in the water as it passes through the bed. Activated carbon filters are widely used water treatment equipment; when employed as a pretreatment step in desalination systems, they help extend the service life of downstream equipment, improve water quality, and prevent fouling—particularly the poisoning of downstream reverse osmosis membranes and ion-exchange resins caused by residual chlorine in the feed water.

The primary factors influencing the adsorption performance and service life of activated carbon filters include the type and concentration of pollutants, the residence time of air within the filter media, and the temperature and humidity of the air.

In practical applications, the filtration configuration and the type of activated carbon should be selected based on factors such as the type and concentration of pollutants and the volume of air to be treated.

Effective dust-filtering pre-filters with an efficiency rating of F7 or higher should be installed upstream and downstream of the activated carbon filter. The upstream filter prevents dust from clogging the activated carbon media, while the downstream filter captures dust generated by the activated carbon itself.

What is the working principle of an activated carbon filter?

The activated carbon filter utilizes granular activated carbon to further remove residual chlorine, organic matter, and suspended solids from the water through mechanical filtration, thereby creating favorable conditions for subsequent reverse osmosis treatment.

Activated carbon filters primarily rely on the high carbon content, large molecular weight, and extensive specific surface area of activated carbon aggregates to physically adsorb impurities in the water, thereby meeting water quality requirements. As water passes through the pores of the activated carbon, van der Waals forces draw various suspended particles and organic substances into these pores. Simultaneously, chlorine (hypochlorous acid) adsorbed on the surface of the activated carbon undergoes a chemical reaction, being reduced to chloride ions, which effectively removes residual chlorine, reducing its concentration to less than 0.1 ppm and satisfying the operating conditions for reverse osmosis membrane (ROM) systems. Over time, the pore size and interparticle spacing within the activated carbon gradually increase, eventually leading to failure when the pressure differential across the filter exceeds its design limit. Under normal circumstances, the filter is backwashed in a counter-current flow to dislodge most of the retained contaminants from the activated carbon pores, carrying them away with the effluent and restoring the adsorption capacity. When the activated carbon reaches its saturation adsorption capacity, it must be regenerated or replaced to meet engineering requirements.